阅读说明：本技术 注射成型系统、成型条件校正系统以及注射成型方法 (Injection molding system, molding condition correction system, and injection molding method ) 是由 岛田辽太郎 荒井聪 于 2021-05-12 设计创作，主要内容包括：本发明提供实现注射成型的品质的注射成型系统。注射成型系统(1)具有决定包含第一金属模具与第一注射成型机的组合的制造条件的工序(31)；检索生产实绩存储部(32)确认有无使用第一金属模具与第一注射成型机的组合的第一生产实绩的工序(33)；在没有第一生产实绩时基于对第一注射成型机预先取得的第一成型机固有信息、对与第一金属模具组合的具有第二生产实绩的第二注射成型机预先取得的第二成型机固有信息、从生产实绩存储部取得的第二生产实绩,制作使用第一注射成型机与第一金属模具的组合注射成型的校正成型条件的工序(43),工序(43)至少校正从第一注射成型机注入第一金属模具的树脂量,将制作的校正成型条件输入第二注射成型机。(The invention provides an injection molding system for realizing the quality of injection molding. An injection molding system (1) comprises a step (31) for determining manufacturing conditions including a combination of a first metal mold and a first injection molding machine; a step (33) of searching for a production record storage unit (32) to confirm the presence or absence of a first production record using a combination of a first mold and a first injection molding machine; and a step (43) of creating a corrected molding condition for injection molding using a combination of the first injection molding machine and the first metal mold based on first molding machine unique information acquired in advance for the first injection molding machine, second molding machine unique information acquired in advance for a second injection molding machine having a second production result to be combined with the first metal mold, and the second production result acquired from the production result storage unit when there is no first production result, wherein the step (43) corrects at least an amount of resin injected from the first injection molding machine into the first metal mold, and inputs the created corrected molding condition into the second injection molding machine.)

1. An injection molding system configured to have one or more computers each including a microprocessor and a memory device,

the injection molding system has:

determining manufacturing conditions including a combination of a first metal mold and a first injection molding machine;

a step of checking whether or not a first production record using a combination of the first mold and the first injection molding machine is present by searching a production record storage unit; and

a step of creating a corrected molding condition for performing injection molding using a combination of the first injection molding machine and the first metal mold based on first molding machine unique information acquired in advance for the first injection molding machine, second molding machine unique information acquired in advance for a second injection molding machine having a second production result combined with the first metal mold, and the second production result acquired from the production result storage unit, in a case where the first production result is absent,

the step of creating the correction molding conditions corrects at least an amount of resin injected from the first injection molding machine into the first metal mold,

inputting the manufactured calibration molding conditions to the first injection molding machine.

2. The injection molding system of claim 1,

the molding machine unique information is information indicating a relationship between a theoretical value and an actual measurement value when a resin is injected into a mold attached to the injection molding machine under predetermined injection conditions.

3. The injection molding system of claim 2,

the predetermined injection condition is that the screw position at the end of the holding pressure step coincides with a VP switching position, which is a screw position for switching between injection and holding pressure.

4. The injection molding system of claim 2,

the molding machine unique information includes the following information: and information obtained by correlating an extrusion distance from the measurement position to the VP switching position, a screw diameter of the injection molding machine, and a volume of an obtained molded product, when injection molding is performed by inputting a plurality of molding conditions in which a screw position at the end of the pressure holding step, a VP switching position that is a screw position at which injection and pressure holding are switched, and a measurement position are changed, to the injection molding machine within a range in which the pressure holding step is set to 0 second and no filling occurs.

5. The injection molding system of claim 1,

the step of creating the corrected molding condition includes correcting a measurement position, a speed switching position, and a VP switching position using a predetermined conversion formula based on the first molding machine unique information, the second molding machine unique information, and the second production result, thereby creating the corrected molding condition.

6. The injection molding system of claim 1,

the injection molding system further includes a step of causing the production record storage unit to register a result of quality inspection of a product obtained by injection molding by the second injection molding machine in accordance with the corrected molding conditions.

7. The injection molding system of claim 6,

the molding machine unique information is information in which, when injection molding is performed by inputting arbitrary molding conditions to an injection molding machine, an actual measurement value of a physical quantity at a predetermined portion in a mold attached to the injection molding machine is associated with the arbitrary molding conditions.

8. The injection molding system of claim 7,

the physical quantity includes at least any one of a mold opening modulus, a temperature, a pressure, and an amount of a resin injected into the metal mold.

9. A molding condition correction system configured to have at least one computer including a microprocessor and a storage device, respectively, and correct molding conditions input to an injection molding machine,

the molding condition correction system is activated without a first production achievement using a combination of the first metal mold and the first injection molding machine,

the molding condition correction system corrects the molding condition so as to correct at least the amount of resin injected from the first injection molding machine into the first metal mold based on first molding machine unique information acquired in advance for the first injection molding machine, second molding machine unique information acquired in advance for a second injection molding machine having a second production achievement combined with the first metal mold, and the second production achievement,

the first molding machine specific information and the second molding machine specific information are information indicating a relationship between a theoretical value and an actual measurement value when a resin is injected into a mold attached to the injection molding machine under a predetermined injection condition.

10. An injection molding method, characterized in that,

the injection molding method executes the following procedures through a computer:

determining manufacturing conditions including a combination of a first metal mold and a first injection molding machine;

a step of checking whether or not a first production record using a combination of the first mold and the first injection molding machine is present by searching a production record storage unit; and

a step of creating a corrected molding condition for performing injection molding using a combination of the first injection molding machine and the first metal mold based on first molding machine unique information acquired in advance for the first injection molding machine, second molding machine unique information acquired in advance for a second injection molding machine having a second production result combined with the first metal mold, and the second production result acquired from the production result storage unit, in a case where the first production result is absent,

the step of creating the correction molding conditions corrects at least an amount of resin injected from the first injection molding machine into the first metal mold,

inputting the corrected molding conditions from the computer to the first injection molding machine.

Technical Field

The invention relates to an injection molding system, a molding condition correction system, and an injection molding method.

Background

In patent document 1, resin flow analysis is performed on the basis of mechanical parameters in a cloud server, an optimal injection condition is generated, and the optimal injection condition is downloaded to a full-automatic injection molding machine for injection molding. Patent document 1 describes the following: "regarding the manufacturing method of the plastic product, the professional system construction of the upstream terminal and the downstream terminal (for example, a machine factory, a product design factory, a model flow analysis software factory, etc.) is integrated in the cloud server, and the optimal manufacturing scheme of the cloud end of the plastic product is integrated. In addition, the controller of the all-electric injection molding machine can take the optimal manufacturing solution of the plastic product from the cloud server. Therefore, the manufacturing process of the all-electric injection molding machine is reduced, and the experience of the machine setup and adjustment can be accumulated systematically to be utilized. As a result, even an inexperienced technician does not adversely affect the production, and the quality of the plastic product can be optimized. "

Patent document 2 discloses a molding condition conversion program for transferring molding conditions used in one injection molding machine to an injection molding machine of another injection molding machine of a different model. Patent document 2 describes the following: the "storage unit B" stores specifications such as a screw diameter of the injection molding machine used so far, injection speed switching position, molding conditions such as a filling time of the metal mold, and the like for an injection process used by the injection molding machine, and specifications such as a screw diameter of the injection molding machine to be used thereafter, which are input from the input unit a. The data stored in the storage means are substituted into a predetermined conversion formula obtained on the basis of the precondition that the filling amount and the filling time of the material for the metal mold are the same, and the molding conditions such as the injection speed and the injection speed switching position in the injection molding machine to be used later are obtained by calculation by the calculation means C. The molding conditions such as the injection speed and the injection speed switching position in the injection molding machine to be used later, which are obtained by the arithmetic unit C, are displayed on the display unit D. "

Documents of the prior art

Patent document 1: japanese patent No. 5709328

Patent document 2: japanese patent No. 3613764

Disclosure of Invention

Problems to be solved by the invention

In the method described in patent document 1, the cloud server analyzes the flow of the resin based on the mechanical parameters, thereby generating optimum molding conditions and obtaining molding conditions for mass production molding. Therefore, patent document 1 presupposes that an optimum molding condition is generated by flow analysis of the resin.

When the flow analysis of the resin is flexibly applied to product design, molding conditions, product structure, metal mold structure, and the like are optimized so that the quality of a molded product predicted from the analysis result satisfies required specifications. However, in the resin flow analysis, only theoretically optimum conditions are obtained. In the resin flow analysis, a prediction error occurs between actual molding and theoretically optimum conditions due to the accuracy of the physical property database of the material used, the physical model used, and the difference (machine difference) inherent to the molding machine that does not appear as the mechanical parameter on the table.

This is because each of the actual injection molding machines has a slight inherent difference even when manufactured with the same design, and the inherent difference affects the behavior of the resin.

Therefore, it is not easy to obtain optimum molding conditions for mass production molding by only resin flow analysis as in patent document 1, and even if an optimum value is found, the optimum value may be different from the optimum value in actual molding. In practice, it is necessary to adjust the molding conditions during mass production molding while checking the quality of the molded product actually obtained with reference to the optimum molding conditions obtained by resin flow analysis. When a mold having a good mass production performance is used in a certain molding machine and molding is performed by another molding machine, a difference exists between the molding machines, and therefore, an adjustment operation of the molding conditions is also necessary.

Patent document 2 does not consider the difference inherent in the molding machines as in patent document 1, and therefore, the molding conditions in one molding machine are simply switched to those for molding machines of other models, and molded products of the same quality cannot be obtained.

The present invention has been made in view of the above problems, and an object thereof is to provide an injection molding system, a molding condition correction system, and an injection molding method that can improve the quality of injection molding.

Means for solving the problems

In order to solve the above problem, an injection molding system according to the present invention is configured to have one or more computers each including a microprocessor and a storage device, wherein the injection molding system includes: determining manufacturing conditions including a combination of a first metal mold and a first injection molding machine; a step of checking whether or not a first production record using a combination of a first mold and a first injection molding machine is present by searching a production record storage unit; and a step of creating, when there is no first production achievement, a corrected molding condition for performing injection molding using a combination of the first injection molding machine and the first metal mold based on first molding machine unique information acquired in advance for the first injection molding machine, second molding machine unique information acquired in advance for a second injection molding machine having a second production achievement combined with the first metal mold, and the second production achievement acquired from the production achievement storage unit, the step of creating the corrected molding condition correcting at least an amount of resin injected from the first injection molding machine into the first metal mold, and inputting the created corrected molding condition to the first injection molding machine.

Effects of the invention

According to the present invention, even in the case where there is no first production achievement based on the combination of the first metal mold and the first injection molding machine, if there is a second production achievement based on the combination of the first metal mold and the second injection molding machine, it is possible to create the corrected molding conditions for performing the injection molding using the combination of the first injection molding machine and the first metal mold based on the first molding machine unique information for the first injection molding machine, the second molding machine unique information for the second injection molding machine, and the second production achievement, and input the created corrected molding conditions to the first injection molding machine.

Drawings

FIG. 1 is a functional block diagram of an injection molding system.

Fig. 2 is an explanatory diagram showing a hardware configuration and a software configuration of a computer that can be used to realize the injection molding system.

Fig. 3 is a sectional view showing the structure of the injection molding machine.

Fig. 4 is a flowchart showing an injection molding method.

Fig. 5 is an explanatory view schematically showing an experiment for confirming the effect of the present example.

Fig. 6 is a block diagram showing a method of acquiring molding machine unique information.

Fig. 7 is a graph showing a relationship between the set value of the holding pressure and the peak pressure, which is different for each molding machine.

Fig. 8 is a graph showing a case where the relationship between the resin temperature and the peak resin temperature differs for each molding machine.

Fig. 9 is a graph showing a temporal change in the open modulus of the metal mold.

Fig. 10 is a graph showing a relationship between a set value of the holding pressure and a remaining amount of the opening modulus of the mold.

Fig. 11 is a flowchart showing a process of generating the correction molding conditions.

Fig. 12 is a table showing a correlation between the characteristic amount of the physical quantity obtained from the in-mold sensor and the corrected molding condition.

Fig. 13 is an explanatory diagram showing a computer configuration of the injection molding system of the second embodiment.

Fig. 14 is an explanatory diagram showing a computer configuration of the injection molding system of the third embodiment.

Fig. 15 is a functional block diagram of an injection molding system of the fourth embodiment.

Fig. 16 is an explanatory diagram showing a hardware configuration and a software configuration of a computer that can be used to realize the injection molding system.

Fig. 17 is a block diagram showing a method of acquiring molding machine unique information.

Fig. 18 is a flowchart showing a method of correcting the injection point boundary condition.

Fig. 19 is a block diagram showing a method of acquiring molding machine unique information according to the fifth embodiment.

Fig. 20 is a graph showing the results of the regression analysis based on the curved surface polynomial model and the experimental value of the maximum open modulus for the set mold clamping force and the load.

Fig. 21 is a flowchart showing details of step S61 in fig. 11.

Fig. 22 is a functional block diagram of an injection molding system of the sixth embodiment.

Fig. 23 is a schematic diagram showing a method of creating a database of measurement steps and a method of correcting the measurement steps.

Fig. 24 is a characteristic diagram showing a relationship between an injection volume and a cylinder extrusion amount.

Fig. 25 is a block diagram showing a method of collecting a correction value (regression coefficient) for correcting information on a measurement process, which is one of molding machine unique information.

Fig. 26 is an explanatory diagram showing an example of a method of correcting a parameter related to a measurement process.

Description of the reference numerals

1: injection molding system, 2: production management system, 3: manufacturing execution system, 4: molding condition correction system, 5: manufacturing plant, 31: manufacturing condition determining section, 32: production record storage, 33: production achievement acquisition unit, 34: manufacturing execution instruction unit, 35: corrected molding condition acquisition unit, 36: production performance learning unit, 41: molding machine unique information storage unit, 42: molding machine unique information acquisition unit, 43: molding condition correction portion, 44: molding machine unique information learning unit, 45: flow analysis unit, 46: analysis result storage unit, 51: manufacturing execution unit, 52: molding condition producing section, 53: quality inspection unit, 57: a sensor.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present embodiment includes the steps of: determining a first metal mold and a first injection molding machine as manufacturing conditions; judging whether the production performance based on the first metal mold exists or not; determining whether or not there is a production achievement based on a combination of the first metal mold and the first injection molding machine; and a step of creating a corrected molding condition for realizing injection molding by the combination of the first metal mold and the first injection molding machine, based on first molding machine unique information acquired in advance for the first injection molding machine, second molding machine unique information acquired in advance for the second injection molding machine having a production result by the combination of the first metal mold and the first injection molding machine, and a production result by the combination of the first metal mold and the second injection molding machine, when there is a production result by the combination of the first metal mold and the first injection molding machine but there is no production result by the combination of the first metal mold and the first injection molding machine. The manufactured calibration molding conditions are input to a first injection molding machine, and injection molding is performed.

According to the present embodiment, when molding is performed by another injection molding machine using a mold having a mass production achievement in a certain injection molding machine, appropriate molding conditions can be obtained based on the mass production achievement of a non-defective product and molding machine unique information acquired in advance.

That is, in the present embodiment, when a mold having a production result (or a mass production result) is used in a certain injection molding machine and molding is performed by another injection molding machine, a good injection molded product is obtained by correcting the injection conditions based on the production result and the molding machine unique information acquired in advance.

In the present embodiment, as the molding machine unique information, the physical quantity corresponding to the machine difference unique to the injection molding machine is acquired in advance and stored in association with the injection molding machine. In the present embodiment, the presence or absence of a production record based on a combination of a certain mold and an injection molding machine is determined, and if the production record is absent, a corrected molding condition is generated based on the production record and molding machine unique information acquired in advance. In the injection molding method of the present embodiment, by using the correction molding conditions, injection molding of a combination of a metal mold and an injection molding machine defined based on the manufacturing conditions can be realized.

Therefore, according to the present embodiment, when molding is performed by another injection molding machine using a mold having a production result in a certain injection molding machine, more suitable injection molding conditions than in the past can be obtained from the production result of obtaining a non-defective product and the molding machine unique information acquired in advance. Thus, for example, when a mold produced at a certain site is transferred to another site for production, condition setting by a skilled operator is not required, and the production preparation time can be shortened and the quality of a molded product can be improved.

In the present embodiment, the physical quantities related to injection molding are described by taking as examples the mold opening modulus, the speed, the pressure, the temperature, and the volume of the resin injected into the mold (the resin amount), but these physical quantities may be a predetermined value or may be a curve (characteristic line) representing a temporal change in the value.

The step of creating the corrected molding conditions of the present embodiment corrects at least the amount of resin injected from the first injection molding machine into the first metal mold, and inputs the created corrected molding conditions to the first injection molding machine.

The molding machine unique information may be information indicating a relationship between a theoretical value and an actual measurement value when a resin is injected into a mold attached to an injection molding machine under predetermined injection conditions.

The predetermined injection condition may be such that the screw position at the end of the holding pressure step coincides with a screw position (VP switching position) at which injection and holding pressure are switched.

The molding machine unique information may include the following information: in the case where injection molding is performed by inputting a plurality of molding conditions in which the screw position at the end of the pressure holding step, the screw position at which injection and pressure holding are switched (VP switching position), and the measurement position are changed within a range in which the pressure holding step is set to 0 second and no filling occurs, information obtained by correlating the extrusion distance from the measurement position to the VP switching position, the screw diameter of the injection molding machine, and the volume of the obtained molded product is obtained.

The step of creating the corrected molding conditions may be performed by correcting the measurement position, the speed switching position, and the VP switching position using a predetermined conversion formula based on the first molding machine unique information, the second molding machine unique information, and the second production results.

[ example 1]

A first embodiment will be described with reference to fig. 1 to 12. Fig. 1 is a functional block diagram of an injection molding system (or injection molding method) 1.

The injection molding system 1 includes, for example: a production management system 2, a manufacturing execution system 3, a molding condition correction system 4, and a manufacturing factory 5. A part or all of the functions of the injection molding system 1 described below may be implemented as software, may be implemented as cooperation of software and hardware, or may be implemented using hardware having a fixed circuit. At least a part of these functions may be implemented by using hardware capable of changing a part of the circuit. At least a part of the functions of the production management system 2, the manufacturing execution system 3, and the manufacturing factory 5 may be manually executed by an operator.

The production management system 2 is a system for managing a production plan, and includes at least a production plan management unit 21. The production plan management unit 21 has a function of generating a production plan including production specifications, quantity, time, date, and the like in accordance with the order status and the stock status.

The manufacturing execution system 3 is a system that instructs a manufacturing factory 5 to execute production. The manufacturing execution system 3 determines manufacturing conditions and molding conditions based on the production plan generated by the production management system 2, and sends a production instruction including the manufacturing conditions and molding conditions to the manufacturing factory 5. The manufacturing conditions include, for example, information specifying an injection molding machine for production (injection molding), information specifying a metal mold for production, information specifying a material for production, the number of molded articles produced, production time and date, and the like.

The manufacturing execution system 3 will be explained. The manufacturing execution system 3 includes, for example: a manufacturing condition determining unit 31, a production record storage unit 32, a production record acquiring unit 33, a manufacturing execution instructing unit 34, a calibration molding condition acquiring unit 35, and a production record learning unit 36.

The manufacturing condition determining unit 31 has a function of determining the manufacturing condition based on the production plan generated by the production plan managing unit 21 of the production management system 2. The manufacturing condition determining unit 31 can transmit information on the manufacturing conditions to the molding condition correction system 4. The information related to the manufacturing conditions can include prescribed information related to the first metal mold and the first injection molding machine. The predetermined information includes, for example, the capacity of the first mold and the flow path structure of the first mold. The predetermined information may include, for example, a control mode (PID (Proportional-Integral-Differential) of the first injection molding machine, a set value, and the like). The manufacturing condition determining unit 31 may transmit one or both of CAD (Computer Aided Design) data of the first mold, specification data of the first injection molding machine, and setting data to the molding condition correcting system 4 as "predetermined information". The molding condition correction system 4 stores the information received from the manufacturing condition determination unit 31 as the molding machine unique information 41.

The production record storage unit 32 is a function of storing production records. In the present example, production actually indicates molding conditions under which good quality of molded articles is confirmed with respect to the combination of the injection molding machine and the metal mold.

The production record acquiring unit 33 is a function of acquiring the production record from the production record storage unit 32. The production result acquiring unit 33 reads out from the production result storage unit 32 the production result based on the mold (hereinafter referred to as the first mold) determined by the manufacturing condition determining unit 31 and the production result based on the combination of the injection molding machine (hereinafter referred to as the first injection molding machine) and the first mold determined by the manufacturing condition determining unit 31, and acquires the production result.

The production record acquiring unit 33 requests the manufacturing execution instructing unit 34 to specify the molding condition when there is no production record based on the first mold. The request for molding condition determination means that a search for an appropriate molding condition is instructed in the manufacturing plant 5. The manufacturing plant 5 finds appropriate molding conditions while changing various parameters according to the input manufacturing conditions.

When there is a production record based on the combination of the first injection molding machine and the first mold, the production record acquiring unit 33 outputs the production record acquired from the production record storage unit 32 to the manufacturing execution instructing unit 34. When there is a production result based on the first mold but there is no production result based on the combination of the first injection molding machine and the first mold, the production result acquisition unit 33 instructs the corrected molding condition acquisition unit 35 to acquire the corrected molding condition.

The corrected molding condition obtaining unit 35 has a function of obtaining, from the molding condition correction system 4, the corrected molding condition based on the combination of the first injection molding machine and the first mold determined by the manufacturing condition determining unit 31.

The corrected molding condition obtaining section 35 has a function of requesting the molding condition correcting system 4 to generate the corrected molding condition and obtaining the corrected molding condition generated by the molding condition correcting system 4. The corrected molding condition obtaining unit 35 obtains the corrected molding conditions from the molding condition correction system 4 by transmitting basic information necessary for the production of the corrected molding conditions to the molding condition correction system 4.

The basic information required for the generation of the correction molding conditions includes, for example: the first injection molding machine and the first mold determined by the manufacturing condition determining unit 31, another injection molding machine (hereinafter, referred to as a second injection molding machine) having a production result based on a combination with the first mold, and a production result (second production result) based on a combination of the second injection molding machine and the first mold.

When the corrected molding conditions are acquired from the molding condition correction system 4, the corrected molding condition acquisition unit 35 outputs the acquired corrected molding conditions to the manufacturing execution instruction unit 34.

The manufacturing execution instruction unit 34 has a function of instructing the manufacturing factory 5 to execute manufacturing. In addition, manufacturing execution can also be referred to as production. The manufacturing execution instruction includes, for example, any one of the molding condition determination request and the production record input from the production record acquiring unit 33, the corrected molding condition acquired by the corrected molding condition acquiring unit 35, and the manufacturing condition determined by the manufacturing condition determining unit 31.

The production record learning unit 36 is a function of recording the molding conditions, for which it is confirmed that good quality of the molded product is obtained in the manufacturing plant 5, in the production record storage unit 32. The production record learning unit 36 registers the molding conditions, which have obtained a quality equal to or higher than a predetermined standard, in the production record storage unit 32 based on the information indicating the quality result of the molded product, which is acquired from the quality inspection unit 53 of the manufacturing plant 5.

The molding condition correction system 4 will be explained. The molding condition correction system 4 has a function of correcting the molding conditions based on the production results input from the manufacturing execution system 3 and molding machine unique information acquired in advance. The molding conditions after correction are referred to as corrected molding conditions.

The molding machine unique information in the present embodiment is information unique to each injection molding machine, and includes a machine difference unique to the injection molding machine in addition to the model and the specification of the injection molding machine.

The machine difference in the present embodiment is a difference between the input molding condition and the physical quantity at the predetermined position in the metal mold when the same molding condition is input to a plurality of injection molding machines.

The predetermined position in the mold is, for example, a resin inlet of the mold. The physical quantity includes, for example, the pressure of the resin, the temperature of the resin, the speed of the resin, the material properties of the resin, and the opening modulus (opening amount) of the metal mold. The material properties include, for example, the density of the resin, the viscosity of the resin, and the fiber length distribution of the resin (in the case of a material containing reinforcing fibers). The difference in level is considered to occur due to, for example, a difference in control algorithms (control modes and set values) such as pressure control and temperature control, a difference in accessory equipment such as a mold temperature controller (not shown), and the like, in addition to a difference in the structure of the injection molding machine 50 described later in fig. 3.

The molding condition correction system 4 will be explained. The molding condition correction system 4 includes, for example: a molding machine unique information storage unit 41, a molding machine unique information acquisition unit 42, a molding condition correction unit 43, and a molding machine unique information learning unit 44.

The molding machine unique information storage unit 41 has a function of storing molding machine unique information acquired in advance for each injection molding machine.

The molding machine unique information acquiring unit 42 has a function of acquiring molding machine unique information of the injection molding machine specified by the manufacturing execution system 3 from the molding machine unique information storage unit 41. The molding machine unique information acquiring unit 42 acquires molding machine unique information (first molding machine unique information) of the first injection molding machine and molding machine unique information (second molding machine unique information) of the second injection molding machine from the corrected molding condition acquiring unit 35 of the manufacturing execution system 3, and outputs the acquired molding machine unique information to the molding condition correcting unit 43. The molding machine unique information acquiring unit 42 may receive the production results acquired by the production result acquiring unit 33 from the production result storage unit 32 via the corrected molding condition acquiring unit 35, and may transfer the received production results to the molding condition correcting unit 43.

The molding condition correcting unit 43 has a function of correcting the molding conditions based on the information input from the molding machine unique information acquiring unit 42. The molding condition correcting unit 43 corrects the molding conditions based on the first molding machine unique information and the second molding machine unique information input from the molding machine unique information acquiring unit 42 and the production results based on the combination of the second injection molding machine and the first mold, thereby generating a function of correcting the molding conditions. The molding condition correcting unit 43 sends the generated corrected molding conditions to the corrected molding condition acquiring unit 35 of the manufacturing execution system 3.

The molding machine unique information learning unit 44 has a function of extracting a feature amount of the physical quantity based on data (sensing data) from a sensor 57 provided in the injection molding mechanism 50 or the mold, and storing the feature amount as the difference information in the molding machine unique information storage unit 41. More specifically, the molding machine unique information learning unit 44 extracts a feature amount from the sensor data in the injection molding processes 54 to 56 obtained from the manufacturing plant 5, and stores the extracted feature amount as the machine difference information in the molding machine unique information storage unit 41.

A manufacturing plant 5 will be explained. The manufacturing factory 5 receives a manufacturing execution instruction from the manufacturing execution system 3 and executes one or more of the injection molding processes 54 to 56. In fig. 1, injection molding is sometimes abbreviated as "IM".

The manufacturing plant 5 includes, for example: a manufacturing execution unit 51, a plurality of injection molding machines 50 (described later with reference to fig. 3), a plurality of molds (described later with reference to fig. 3), a molding condition creation unit 52, and a molded product quality inspection unit 53. Hereinafter, the molded product quality inspection unit 53 may be referred to as a quality inspection unit 53.

The manufacturing execution unit 51 executes the injection molding process based on the manufacturing conditions input from the manufacturing execution instruction unit 34 of the manufacturing execution system 3. When the correction molding conditions are input, the manufacturing execution unit 51 inputs the correction molding conditions for the combination of the injection molding machine and the metal mold indicated in the manufacturing conditions, and thereby executes the injection molding process 54. That is, the injection molding process 54 is a process of performing injection molding according to the correction molding conditions.

When the production results are input, the manufacturing execution unit 51 inputs the production results for the combination of the instructed injection molding machine and the mold, and thereby executes the injection molding process 55. That is, the injection molding process 55 is an injection molding process performed under molding conditions in which the performance of production of non-defective products is present, using a combination of a predetermined injection molding machine and a metal mold.

When the molding condition determination request is input, the manufacturing execution unit 51 gives an instruction to determine the molding condition to the molding condition creation unit 52. The molding condition creating unit 52 derives an optimum molding condition for stably obtaining a non-defective product when receiving a molding condition determination request from the manufacturing execution unit 51. When deriving the molding conditions, the flow of the resin is analyzed in advance, and the approximate molding conditions are found, whereby the time for determining the molding conditions can be shortened. When the quality inspection unit 53 can confirm that the non-defective product is stably obtained according to the derived molding conditions, the derived optimum molding conditions are input to execute the injection molding process 56. That is, the injection molding process 56 is a process of deriving molding conditions and performing injection molding in accordance with the derived molding conditions.

The quality inspection unit 53 has a function of determining whether or not the quality of the molded product obtained by the injection molding process is good. The quality of the molded article is evaluated, for example, in terms of the size, the amount of warpage, burrs, scars, gloss, color, and the like. The quality inspection of the molded product may be performed automatically, manually by an inspector, or semi-automatically.

When the quality of the molded product is good, the quality inspection unit 53 outputs the inspection results of the manufacturing conditions, the combination of the injection molding machine and the mold, the molding conditions, and the quality of the molded product to the production result learning unit 36 of the manufacturing execution system 3.

Further, the molding machine specific information of the present embodiment is obtained by measuring the physical quantity at a predetermined position in the mold by each injection molding machine held in advance in the manufacturing plant 5 and the sensor 57 mounted on the mold, and outputting the measured physical quantity to the molding condition correction system 4.

Fig. 2 shows a configuration example of a computer 10 that can be used to realize the injection molding system 1 of the present embodiment. Here, a case where the injection molding system 1 is implemented by one computer 10 will be described, but the present invention is not limited thereto, and one or a plurality of injection molding systems 1 may be constructed by causing a plurality of computers to cooperate with each other. As described above, the production management system 2, the manufacturing execution system 3, and the manufacturing factory 5 can implement the injection molding system 1 by an operator performing a part or all of the functions without using dedicated software or hardware.

As in another embodiment described later, the molding condition correction system 4 may be configured as software that functions on a cloud server and can be shared with a plurality of users. In this case, the molding machine unique information recorded in the molding machine unique information storage unit 41 can be shared among a plurality of users. In this case, when the number of users increases, the number of times of obtaining the molding machine unique information can be reduced because the corrected molding conditions can be obtained by flexibly using the molding machine unique information obtained by another user increases.

The computer 10 includes, for example: the computing device 11, the memory 12, the storage device 13, the input device 14, the output device 15, the communication device 16, and the medium interface unit 17 are connected through a communication path CN 1. Communication path CN1 is, for example, an internal bus, lan (local Area network), or the like.

The arithmetic device 11 is constituted by a microprocessor or the like, for example. The arithmetic unit 11 reads out the computer program stored in the storage unit 13 to the memory 12 and executes the computer program, thereby realizing the functions 21, 31 to 36, 41 to 44, 51, 52, and 60 as the injection molding analysis system 1.

The storage device 13 is a device for storing computer programs and data, and includes a rewritable storage medium such as a flash memory or a hard disk. The storage device 13 stores a computer program for realizing a GUI unit 60 for providing a GUI (Graphical User Interface) to an operator, and a computer program for realizing the functions 21, 31 to 36, 41 to 43, 51, and 52.

The input device 14 is a device for an operator to input information to the computer 10. Examples of the input device 14 include a pointing device such as a keyboard, a touch panel, and a mouse, and an audio pointing device (none of which are shown). The output device 15 is a device for outputting information from the computer 10. Examples of the output device 15 include a display, a printer, and a voice synthesizer (none of which are shown).

The communication device 16 is a device that causes an external information processing device and the computer 10 to communicate via a communication path CN 2. As an external information processing apparatus, there is an external storage apparatus 19 in addition to a computer not shown. The computer 10 can read data (molding machine unique information, production results, etc.) and a computer program stored in the external storage device 19. The computer 10 can transmit all or a part of the computer program and data stored in the storage device 13 to the external storage device 19 for storage.

The medium interface 17 is a device for reading from and writing to an external recording medium 18. Examples of the external recording medium 18 include a USB (Universal Serial Bus) memory, a memory card, and a hard disk. The computer program and data may be transferred from the external recording medium 18 to the storage device 13, and all or a part of the computer program and data stored in the storage device 13 may be transferred to the external recording medium 18 and stored.

Fig. 3 shows an outline of the injection molding machine 50. The respective processes of the injection molding process will be described with reference to fig. 3. In the present embodiment, the molding phenomenon represents a series of phenomena generated in the course of injection molding. In the present embodiment, the injection molding process is roughly divided into a measurement and plasticization process, an injection and pressure holding process, a cooling process, and a take-out process.

In the measurement and plasticization processes, the screw 502 is retracted by using the plasticization motor 501 as a driving force, and the resin pellet 504 is supplied from the hopper 503 into the cylinder 505. The resin is plasticized by heating by the heater 506 and rotation of the screw 502 to be in a uniform molten state. The density of the molten resin and the degree of breakage of the reinforcing fibers are changed by setting the back pressure and the rotation speed of the screw 502. These variations affect the quality of the molded product.

In the injection and pressure holding processes, the screw 502 is advanced by the injection motor 507 as a driving force, and the molten resin is injected into the mold 509 through the nozzle 508. In the molten resin injected into the mold 509, cooling from the wall surface of the mold 509 and shear heat generation due to the flow act in parallel. That is, the molten resin flows into the cavity of the metal mold 509 while being cooled and heated.

After the molten resin is filled into the metal mold 509, a volume shrinkage amount accompanying cooling of the molten resin is supplied to the metal mold 509 by applying a holding pressure. Here, when the mold clamping force, which is the force for closing the mold 509, is small relative to the pressure during injection and the pressure during holding, a minute mold opening occurs after the molten resin is solidified, and the quality of the molded product is affected by the minute gap.

During the cooling process, the molten resin is cooled to below the solidification temperature by the metal mold 509 maintained at a certain temperature. The residual stress generated in the cooling process affects the quality of the molded product. The residual stress is caused by anisotropy of material properties due to flow in the mold, density distribution by pressure holding, variation in molding shrinkage, and the like.

In the taking-out process, the mold clamping mechanism 512 is driven by a motor 511 for opening and closing the mold 509 as a driving force, thereby opening the mold 509. Then, the ejection mechanism 514 is driven by using the protrusion motor 513 as a driving force, and the solidified molded product is taken out from the metal mold 509. Thereafter, the metal mold 509 is closed toward the next injection. When the molded article is taken out from the mold 509, if a sufficient protrusion force is not uniformly applied to the molded article, residual stress remains in the molded article, which affects the quality of the molded article.

In the injection molding machine 50, the pressure control is performed so that the pressure value of the load cell 510 approaches the pressure value within the input molding conditions. The temperature of cylinder 505 is controlled by a plurality of heaters 506. A different pressure loss is generated for each injection molding machine depending on the shape of the screw 502, the shape of the cylinder 505, and the shape of the nozzle 508. Thus, the pressure at the resin flow inlet of the metal mold 509 is a value lower than the pressure indicated by the molding conditions input to the injection molding machine. Further, the resin temperature at the resin inlet of the mold 509 may be different from the resin temperature indicated by the molding conditions input to the injection molding machine due to the arrangement of the heater 506 and the shear heat generation of the resin at the nozzle portion. The structure of the injection mechanism (the shape of the screw 502, the shape of the cylinder 505, the shape of the nozzle 508, the arrangement of the heater 506, and the like) differs depending on the injection molding machine. Therefore, the molding conditions are corrected so that the physical amounts of the molten resin at the resin flow inlet of the metal mold 509 are equal, whereby the same quality of molded articles can be obtained even with different injection molding machines.

The quality of the molded article was evaluated by shape characteristics (weight, length, thickness, sink mark, burr, warpage, etc.), surface characteristics (weld, silver streak, burn, whitening, scratch, bubble, peeling, flow mark, jet mark, color, gloss, etc.) such as appearance defects, mechanical and optical characteristics (tensile strength, impact resistance, etc.).

The shape characteristics have strong correlation with the history of pressure and temperature and the mold clamping force in the injection and pressure holding process and the cooling process. The surface characteristics differ from the phenomena occurring, respectively, but for example, flow marks and jet marks have a strong correlation with the temperature and velocity of the resin during injection. Mechanical and optical properties, for example, in the case of tensile strength, require evaluation in a fracture test, and therefore, are often evaluated by using other quality indexes related to weight and the like.

Parameters corresponding to respective processes of the injection molding process are set in the molding conditions. For the measurement and plasticization process, a measurement position, a suck-back, a back pressure speed, a rotation speed, and the like are set. With respect to the injection and dwell procedures, pressure, temperature, time and speed were set, respectively. In the injection and pressure holding process, a screw position (VP switching position) for switching between injection and pressure holding and a mold clamping force of the metal mold 509 are also set. Regarding the cooling process, the cooling time after the pressure holding was set. As parameters related to the temperature, the temperatures of the plurality of heaters 506, the temperature and the flow rate of the refrigerant for cooling the metal mold 509, and the like are set.

Fig. 4 is a flowchart showing an example of the injection molding method performed by the injection molding system 1. In the drawings, the injection molding machine is referred to simply as a molding machine. In fig. 4, the first mold is represented as the determined mold, and the first injection molding machine is represented as the determined molding machine.

The production management system 2 acquires the order status, the stock status, and the like, which are information for determining the production plan, from the production plan management unit 21 implemented by the GUI unit 60 (S1). For example, the operator determines the optimum production specification, quantity, and date and time based on the order status and stock status displayed on the GUI, and generates a production plan (S1). Alternatively, a production plan can be automatically generated by introducing a mathematical plan model and an algorithm for optimizing the entire logical matrix.

The manufacturing execution system 3 acquires the production plan from the manufacturing condition determining unit 31 realized by the GUI unit 60, and determines the manufacturing conditions (S2). For example, the operator determines an optimum combination of the first injection molding machine and the first metal mold according to the production plan and the operating conditions of the injection molding machine of the manufacturing plant 5. Alternatively, by introducing a mathematical planning model and an algorithm for optimizing the production efficiency, the production conditions can be automatically determined.

The production record acquiring unit 33 refers to the production record of the first mold determined in step S2 recorded in the production record storage unit 32, and determines whether or not there is a production record (S3). If the production result is not based on the first mold (no in S3), the production result obtaining unit 33 outputs a molding condition determination request to the manufacturing execution instructing unit 34 (S4). If there is a production achievement based on the first metal mold (S3: yes), the process proceeds to step S5.

When the molding condition specification request is input from the production record acquiring unit 33, the manufacturing execution instructing unit 34 gives an instruction to specify the molding condition to the manufacturing plant 5 (S4). For example, in the molding condition creating unit 52, the operator checks the instruction for setting the molding condition from the manufacturing execution unit 51 realized by the GUI unit 60. Then, the operator performs an injection molding process based on the combination of the first injection molding machine and the first metal mold, thereby deriving an optimum molding condition under which acceptable products are stably obtained (S4). In step S4, by deriving a theoretically optimum molding condition by resin flow analysis in advance, the number of repetitions of the injection molding process (the number of trial and error) in determining the molding condition can be reduced.

The production record acquiring unit 33 refers to the production record based on the combination of the first injection molding machine and the first mold determined in step S2, which is recorded in the production record storage unit 32, and determines whether or not there is a production record (S5). When there is a production result based on the combination of the first injection molding machine and the first mold (yes in S5), the production result obtaining unit 33 outputs the obtained production result to the manufacturing execution instructing unit 34 (S7). When there is no production result based on the combination of the first injection molding machine and the first mold (no in S5), the production result acquiring unit 33 instructs the corrected molding condition acquiring unit 35 to acquire the corrected molding condition (S5).

The corrected molding condition obtaining unit 35 inputs the first injection molding machine, the first mold, the second injection molding machine having the production result based on the combination with the first mold, and the production result based on the combination of the second injection molding machine and the first mold determined by the manufacturing condition determining unit 31 to the molding condition correction system 4, and creates a corrected molding condition (S6). The corrected molding condition obtaining unit 35 outputs the created corrected molding condition to the manufacturing execution instructing unit 34 (S6).

The manufacturing execution system 3 outputs a manufacturing execution instruction including the manufacturing condition determined in step S2 and the production result input in step S5 or the correction molding condition input in step S6 to the manufacturing plant 5 from the manufacturing execution instruction section 34 realized by the GUI section 60 (S7).

For example, the operator can confirm the determined manufacturing conditions and production results or correct the molding conditions, and if there is no problem in the contents, can provide an instruction to the manufacturing plant 5 to perform manufacturing. Alternatively, the operator can provide the molding condition with the machine difference corrected without confirming the determined production performance or the content of the corrected molding condition.

The operator checks the contents of the manufacturing execution instruction via the manufacturing execution unit 51 realized by the GUI unit 60, and executes the injection molding process in accordance with the combination of the instructed injection molding machine, metal mold, and molding conditions (S7).

When the quality of the molded product obtained through the injection molding process performed in step S4 or step S7 is good, the molded product quality inspection unit 53 registers, for example, the production performance learning unit 36 with the inspection results of the manufacturing conditions, the combination of the injection molding machine and the metal mold, the molding conditions, and the quality of the molded product (S8). The GUI unit 60 can be used for information registration with the production performance learning unit 36. Accordingly, when the same combination of the injection molding machine and the mold is determined as the manufacturing condition next time or later, the manufacturing can be performed based on the production results stored in the production results storage unit 32.

Fig. 5 shows an outline of experimental example 6 for verifying the effect of the present example. The experimental situation is shown on the upper side of fig. 5. Table 65 of the experimental results is shown on the lower side of fig. 5. Table 65 contains a part of the input values of the molding conditions in the verification experiment and the evaluation results.

The mold structure 60 shown on the upper side of fig. 5 is a structure in which a resin flows into a cavity from a gate 61 in a 2-point side gate manner. In an actual molding experiment, a pressure sensor and a resin temperature sensor (both not shown) were disposed in the sensor arrangement portion 62 of the runner. A die position sensor (not shown) is disposed in the sensor arrangement portion 64 in the center of the cavity 63.

In experimental example 6, the time variation of the pressure and temperature in the cavity 63 was obtained as the molding phenomenon. In experimental example 6, the temporal change in the mold opening modulus was obtained.

In the data obtained in experimental example 6, the peak value of the pressure sensor (peak pressure in the figure) and the peak value of the temperature sensor (peak resin temperature in the figure) were obtained as "feature amounts". The weight of the molded article obtained was measured as an index of the quality of the molded article. Polypropylene was used as a material for molding. The injection molding machine used an electric injection molding machine (hereinafter referred to as a molding machine IMB) having a maximum mold clamping force of 55t and a screw diameter of 25mm and an electric injection molding machine (hereinafter referred to as a molding machine IMA) having a maximum mold clamping force of 50t and a screw diameter of 26 mm.

Experiments were performed on 3 types in total, namely, a case where the same molding conditions are input to the molding machine IMA and the molding machine IMB, and a case where corrected molding conditions for the molding machine IMB are generated based on molding machine unique information acquired in advance and input.

Further, since the screw 602 diameter of the molding machine IMA is different from the screw diameter of the molding machine IMB, the injection speeds were converted and inputted so as to be equal to each other (32.4 mm/s for the injection speed of the molding machine IMA, 30mm/s for the injection speed of the molding machine IMB, and 17.2cm3/s for each injection rate). Parameters relating to the measurement and plasticization process are also converted and input in the same way.

Referring to table 65 shown on the lower side of fig. 5, the case where the same molding conditions are input to the molding machine IMA and the molding machine IMB is compared. The peak pressure and peak resin temperature of the molding machine IMB become low. On the other hand, when the corrected molding conditions are input to the molding machine IMA, as shown on the right side of the table 65, there is almost no difference between the peak pressure and the peak resin temperature between the molding machine IMA and the molding machine IMB after the correction. Accordingly, the weight error of the molded article obtained by the molding machine IMA and the molding machine IMB was improved by 0.65% before and after the correction. This is a result of inputting the corrected molding conditions, in which the pressure holding and resin temperature are corrected, to the injection molding machine IMA based on the molding machine unique information acquired in advance.

Fig. 6 is a block diagram showing an example of a method of acquiring molding machine unique information of an injection molding machine. The method of acquiring the molding machine unique information shown in fig. 6 is realized by using a "sensor-equipped mold" or a "sensor-embedded mold" in which a sensor for measuring a predetermined physical quantity is provided at a predetermined position, as described in fig. 5.

First, a physical quantity at a predetermined position in a mold is acquired by inputting arbitrary molding conditions 701 to an actual injection molding machine 702. Here, the injection molding machine 702 corresponds to the injection molding machine 50 described in fig. 3.

The molding conditions 701 need not be single, but may be plural. The physical quantity can be obtained under various molding conditions within a range in which a good product is obtained as the quality of a molded product.

The difference in the injection molding machine may vary depending on the set values of the resin temperature and the holding pressure, and therefore, even if the difference is obtained under a single molding condition, the difference may be ineffective. As the molding condition 701, it is preferable to set a condition in which the pressure holding is completed after the gate is sealed. This is because, when the hold pressure is not sufficiently maintained for a sufficient time and the hold pressure is completed before the gate sealing is performed, the resin flows backward from the gate portion, and the filling density of the molded product may decrease. In this case, it is difficult to evaluate the correlation with the quality of the molded product.

In order to obtain a molding phenomenon in the actual injection molding machine 702, there is a method of using an in-mold sensor 705 or an in-mold sensor 706. An example of an in-mold sensor 705 is the load cell 510 shown in FIG. 3.

When the in-mold sensor 705 is used, for example, injected air is ejected without mounting the mold 703, and the output of the load cell 510 at this time is observed, thereby indirectly measuring the pressure loss by the injection mechanism. Alternatively, a sensor is mounted on the nozzle portion to measure the state of the resin just before the resin flows into the mold. In the case of measuring the resin temperature, the temperature of the resin obtained by the air injection may be directly measured by a thermometer or the like.

When the in-mold sensor 706 is used, the molding phenomenon in the mold 703 can be directly measured by disposing the sensor at an arbitrary position in the mold 703, and the actual measurement value 708 of the physical quantity can be obtained. The quality of the molded product 704 can be obtained by product quality inspection 707.

From the obtained physical quantities, characteristic quantities are obtained (709). All of the obtained physical quantities were obtained as a time change in the course of injection molding, and thus, it was difficult to directly evaluate them. Therefore, in the present embodiment, by obtaining the characteristic amount that can affect the quality of the molded product from the temporal change of the physical amount, quantitative evaluation of the setup difference of the injection molding machine 702 can be performed.

In the present embodiment, the obtained feature amount is recorded in the molding machine unique information database 710 in association with an arbitrary molding condition that is initially input. The molding machine unique information database 710 corresponds to the molding machine unique information storage unit 41 of fig. 1.

The measurement results of the experimental example described in fig. 5 will be described with reference to fig. 7, 8, 9, and 10. Fig. 7 and 8 show measurement results in the die structure 60 when the in-die sensor 706 is used to obtain actual measurement values of physical quantities.

As described above, in the present experiment, the peak value of the pressure sensor and the peak value of the resin temperature sensor at the sensor arrangement portion 62 of the flow channel were acquired. The "molding machine IMA" indicated by diamond-shaped measurement points was an injection molding machine having the above-described maximum mold clamping force of 50t and a screw diameter of 26 mm. The "molding machine IMB" indicated by the measurement point of the fork mark is the above-described injection molding machine having the maximum mold clamping force 55t and the screw diameter of 25 mm. Experiments were performed on a plurality of input values of the holding pressure and the resin temperature, respectively.

Fig. 7 shows the peak pressure of the pressure sensor with respect to the set value of the dwell pressure. As shown in fig. 7, the peak pressure value is smaller than the set value of the holding pressure due to the pressure loss of the injection mechanism. In the 2 molding machines IMA, IMB, the slope of the obtained set value of the holding pressure and the peak pressure was different. Therefore, it is preferable to obtain the difference of the trial pressure under a plurality of molding conditions.

Fig. 8 shows the peak temperature of the resin temperature sensor with respect to the set value of the resin temperature. As shown in fig. 8, the peak temperature value with respect to the set value differs between the molding machine IMA and the molding machine IMB depending on the injection mechanism. By thus acquiring the actual measurement value of the physical quantity using the in-mold sensor 706, the variation in the vicinity of the mold inlet can be directly evaluated. This makes it possible to accurately obtain the characteristic amount of the physical quantity necessary for deriving the correction molding condition.

Fig. 9 and 10 are graphs showing a case where the actual mold clamping force is insufficient even when the calculated necessary mold clamping force is set as the molding condition. The metal mold 60 used for the experiment is as shown in fig. 5. As shown in fig. 5, a mold position sensor (not shown) capable of measuring a time change in the mold opening modulus of a minute amount of the mold during the injection molding process is provided at the sensor arrangement portion 64 of the mold 60, and the mold is molded while measuring the mold clamping force as a parameter by the mold position sensor.

In fig. 9, the projected area of the metal mold structure 60 is about 50 square centimeters. The necessary mold clamping force F at this time is obtained by the following formula (1).

F ═ PA … (equation 1)

"F" is the necessary mold clamping force, "P" is the cavity pressure, "A" is the projected area. As the cavity pressure, any higher value of the injection pressure of the molding condition or the pressure of the holding pressure process is used. Alternatively, the pressure acting on the cavity is actually used in consideration of the pressure loss in the injection molding machine and the pressure loss of the gate and runner portion in the metal mold. For example, as shown in fig. 7, a value obtained by measuring the pressure in the chamber may be used.

The necessary mold clamping force calculated according to the formula (1) was 30t at a holding pressure of 60 MPa. Therefore, under the conditions shown in fig. 9, the molding quality is not affected. However, when the pressure is maintained at 50MPa or more, the mold opening modulus does not return to the original position even during the cooling process, and about 10 to 30 μm remains. In this case, burrs are generated in the molded product, the weight becomes too large, and the like, which affects the quality of the molded product.

FIG. 9 shows the measured values of the mold opening modulus at the time of holding pressure was changed in the range of 20 to 60MPa with the mold clamping force set at 40 t. As shown in fig. 9, the mold opening modulus is at a peak during the injection, and then the mold is gradually returned to its original position during the pressure retaining. In the first place, if the mold clamping force is sufficient, the mold opening modulus should be returned to the original position during the cooling process.

FIG. 10 shows the residual amount of mold opening in the cooling process when the mold clamping force is changed to 20 to 40 t. As shown in fig. 10, it is understood that the remaining amount of the mold opening is different depending on the mold clamping force. For example, when the holding pressure is 40MPa, the mold clamping force is 20t, and the mold is slightly opened.

Since there is a difference between the injection molding machines, there is a possibility that the quality cannot be maintained by setting only the calculated necessary mold clamping force as the molding condition. This is because the mold clamping force is insufficient in practice, and burrs or the like may be generated.

Therefore, in the present embodiment, the effective mold clamping force inherent to the injection molding machine that can be molded when the mold clamping force is sufficient is experimentally obtained in advance for the set value of the mold clamping force of the injection molding machine, and the calibration molding condition that can ensure the quality of the molded product can be selected.

A method of deriving an effective mold clamping force inherent in an injection molding machine will be described. As in the example of fig. 7, the threshold values of the mold clamping force and the mold internal pressure are derived from the output values of the mold position sensors provided on the parting surfaces of the mold 60.

And (5) performing injection molding by taking the pressure in the injection and pressure maintaining processes as parameters, and recording the time change of the opening modulus of the metal mold. As shown in fig. 9 and 10, the remaining mold opening modulus was recorded during the cooling process of the mold.

Then, the necessary mold clamping force (force applied to the inside of the mold) with respect to the set value of the holding pressure is calculated according to the formula (1). At this time, the minimum value of the pressure holding that the residual quantity of the opened metal mold is small enough not to affect the quality of the molded product is obtained. The force applied to the inside of the metal mold at the minimum value of the holding pressure is recorded in the molding machine unique information database 710 as the effective mold clamping force unique to the injection molding machine.

At this time, the effective mold clamping force relationship with respect to the set value of the mold clamping force is obtained by molding by appropriately changing the value of the mold clamping force. Thus, the mold clamping force can be set to obtain a more stable quality of the molded product than before, taking into account a slight amount of mold opening that affects the quality of the molded product.

Here, the force applied to the inside of the mold with respect to the set value of the dwell pressure can be calculated according to the formula (1) using the set value of the dwell pressure. The force applied to the inside of the mold with respect to the set value of the holding pressure can be calculated by predicting the pressure acting on the mold by flow analysis according to the following formula (2).

F ═ Σ PiAi … (formula 2)

The subscript (variable) of the sum sign Σ is "i". "i" represents the number of segments obtained by dividing the total projected area in the analytical model. "Pi" represents the average pressure of each segment. "Ai" is the area of each section.

In molding for obtaining the effective mold clamping force, a pressure sensor may be introduced into the mold to actually obtain the maximum value of the pressure. Thus, the necessary mold clamping force can be calculated from the formula (1) in consideration of the pressure actually applied to the mold. Thus, even when the formula (1) is used, the effective mold clamping force inherent to the injection molding machine can be accurately set.

A portion in the mold (hereinafter referred to as a measurement portion) for measuring a physical quantity other than the mold opening modulus will be described. Preferably, even in any of the metal mold structures, the measurement site includes at least a gate portion or a runner portion from a resin inflow port in the metal mold to the cavity.

The cavity may be used as the measurement site, but when the molding machine unique information is derived by the above-described procedure, it is necessary to take into account the pressure loss from the resin inlet to the cavity. Therefore, it is necessary to ensure the analysis accuracy from the resin inlet to the cavity.

When a sensor is installed in the cavity to perform measurement, traces resulting from the shape of the sensor may remain on the molded article. Therefore, there is a restriction that the sensor cannot be introduced at a place where the appearance quality is required.

Therefore, in the present embodiment, the molding machine unique information can be obtained easily and with high accuracy by using the gate portion or the runner portion which is close to the resin inlet and does not require the appearance quality as the measurement portion.

In addition to the gate portion and the runner portion, for example, a portion where a characteristic flow can be observed such as a portion immediately below the gate, a resin joining portion (welded portion), a flow end portion, or the like in the cavity may be used as the measurement portion. In this case, the molding machine unique information can be obtained with higher accuracy from the physical quantities obtained by the plurality of sensors.

For example, since the flow velocity of the molten resin can be obtained from the passage time before the flow at the plurality of measurement points, the molding machine unique information on the velocity of the molten resin can be derived. By measuring the pressure and temperature at this time, the viscosity of the molten resin in the mold can be estimated and compared with the analytical model.

In addition, the appropriate measurement site differs depending on the metal mold structure and the physical quantity to be measured. In the physical quantities other than the mold opening modulus, it is preferable that the gate portion be a measurement portion, if possible, in any mold structure. In the present specification, the expression "preferably" is used merely in a sense that some advantageous effects can be expected, and does not necessarily mean that the structure thereof is essential.

In the case where it is difficult to provide a sensor in the gate portion in view of the design of the mold, the sensor may be disposed in the runner portion. In the case of a direct gate, since there is no runner portion, a portion as close as possible to the gate is selected from the cavity as a measurement portion.

The sensor is disposed in the runner section directly below the gate section, the runner section directly in front of the gate section, and the like in the side gate, the jump gate, the dive gate, and the banana gate. In the case of the pin-point gate, since the gate has a 3-plate structure, it takes a lot of time to dispose the sensor, but the sensor is disposed in a runner portion or the like directly below the gate portion. In the case of a pin gate, a dummy flow channel not connected to the cavity may be provided as a measurement site for measurement. By providing a portion dedicated for measurement, the degree of freedom in designing the metal mold will be improved. In the case of a thin film gate or a sector gate, a sensor is disposed in a runner portion before flowing into the gate portion.

Further, as shown by the arrangement position 64 of the mold position sensor in fig. 5, for example, the measurement of the mold opening modulus is preferably set to a position close to the center portion of the cavity surface of the mold. In a metal mold having an ejection mechanism, the central portion is affected by the deflection of the metal mold due to the pressure of the resin, as compared with the peripheral portion directly receiving the mold clamping force from the molding machine, and therefore the mold opening modulus is more likely to increase.

The parameters measured as the above physical quantities will be explained. In the present embodiment, in order to derive the correction molding conditions, at least the mold opening modulus, pressure, and temperature are measured. For the measurement of the mold opening modulus, pressure, and temperature, for example, a mold position sensor, a mold internal pressure sensor, a mold surface temperature sensor, a resin temperature sensor, and the like can be used. As the resin temperature sensor, either or both of a contact type temperature sensor such as a thermocouple and a noncontact type temperature sensor such as an infrared radiation thermometer can be used.

Any of the physical quantities of the mold opening modulus, pressure, and temperature was recorded as a time change in the injection molding process. When the mold opening modulus is not measured, the mold clamping force is insufficient due to the inherent mechanical difference of the injection molding machine, and there is a possibility that the molding phenomenon and the quality of the molded product are affected. Even if the corrected molding conditions are derived using either one of the pressure and the temperature as the evaluation criterion, the molded product quality of the obtained molded product may be different when both parameters are different from the set values as shown in fig. 8. Therefore, by measuring at least the die opening modulus, the pressure, and the temperature, the calibration molding conditions can be obtained with high accuracy.

The injection molding system 1 can obtain the mold opening modulus, the temperature, and the pressure, as well as the pre-flow velocity and the pre-flow passage time. From the sensors detecting the speed and passage before flow, information on the point in time of the passage before flow can be obtained, rather than the time variation in the injection molding process. When the pre-flow passage time is obtained, at least 2 or more sensors are provided, and the passage times of the resin between 2 points are compared. By detecting the speed before the flow and the passage timing, the injection speed can be evaluated more accurately.

The characteristic amounts of the above physical amounts will be explained. The derivation of the correction molding conditions in the present embodiment can use, for example, the die opening modulus after the completion of the cooling process, the maximum value and the integrated value of the pressure, and the maximum value of the temperature. The mold opening modulus after the end of the cooling process needs to be set to a mold closing force that does not cause a slight mold opening that affects the quality of the molded product. A maximum value of pressure is required in order to evaluate the pressure loss caused by the injection mechanism. However, even if the maximum value of the pressure is only made uniform, the pressure distribution in the cavity changes when the time change of the resin temperature in the pressure holding process is different, and therefore, the quality of the molded product is affected. Therefore, by acquiring the integral value of the pressure during the injection molding process, the correction molding condition can be derived with high accuracy in consideration of the influence of the temperature change during the process.

In the case where the corrected molding conditions are derived using only the characteristic amounts obtained from the pressure, for example, in the case where the corrected molding conditions are derived by changing the resin temperature or the like, the molding phenomenon and the quality of the molded product may be affected. Therefore, the molding machine unique information is acquired in consideration of the maximum value of the temperature in addition to the characteristic amount obtained from the pressure, and thereby, the corrected molding conditions for obtaining good quality of the molded product can be derived.

In addition, it is also effective to obtain the maximum value of the time differential value with respect to the time change of the pressure. The characteristic quantity is related to the instantaneous viscosity of the material. The integrated value of the pressure can also be calculated separately from the injection process and the holding pressure process. The integral value of the pressure during injection is related to the average viscosity of the material during injection.

In the case of using an infrared radiation type resin temperature sensor, the maximum value of the time differential value may be obtained with respect to the time-varying output value of the temperature sensor during injection. The characteristic amount is related to the pre-flow velocity of the molten resin. In the case of measuring the pre-streaming speed, it is directly used as a feature quantity related to the pre-streaming speed. When the pre-flow passage time is obtained, the flow velocity is calculated from the passage time between 2 points and used as the feature value. By recording the relationship of the flow rate with respect to the set value of the injection rate in advance, the injection rate can be corrected more accurately.

A method of creating the correction molding conditions will be described with reference to fig. 11 and 12. Fig. 11 is a flowchart showing details of step S6 in fig. 4. As described above, in step S6, the molding condition correction unit 43 acquires the molding machine unique information of the first injection molding machine, the molding machine unique information of the second injection molding machine, and the production result based on the combination of the second injection molding machine and the first mold from the molding machine unique information acquisition unit 42, thereby generating the corrected molding condition based on the combination of the first injection molding machine and the first mold.

The molding condition correcting unit 43 corrects the mold clamping force (S61). In step S61, for example, a set value of the mold clamping force of the second injection molding machine and an effective mold clamping force of the second injection molding machine based on the set value are referred to based on the production results. Then, in step S61, the set value of the mold clamping force of the first injection molding machine is determined so that the effective mold clamping force of the first injection molding machine is equal to the effective mold clamping force of the second injection molding machine.

The molding condition correcting section 43 corrects the resin temperature (S62). In step S62, for example, as shown in fig. 8, the set value of the resin temperature of the second injection molding machine and the resin temperature of the mold inlet of the second injection molding machine based on the set value are referred to in accordance with the production results. In step S62, the set value of the resin temperature of the first injection molding machine is determined so that the resin temperature of the mold inlet of the first injection molding machine is equal to the resin temperature of the mold inlet of the second injection molding machine.

The molding condition correcting section 43 corrects the mold temperature (S63). In step S63, for example, the set values of the refrigerant temperature and the flow rate in the mold temperature regulator attached to the second injection molding machine, and the mold temperature of the mold inlet of the second injection molding machine with respect to the set values are referred to based on the production results. Then, in step S63, the set value of the refrigerant temperature and the set value of the flow rate in the mold temperature adjusting machine attached to the first injection molding machine are determined so that the mold temperatures at the mold inlet of the first injection molding machine are equal to each other.

The molding condition correcting section 43 corrects the injection speed and the holding pressure speed. Here, in step S64, the velocity is corrected using the following equations (3) to (6).

VIA VIB × ATB/ATA … (equation 5)

VHA-VHB × ATB/ATA … (formula 6)

Here, "ATA" represents a cross-sectional area of the screw of the first injection molding machine. "ATB" represents the cross-sectional area of the screw of the second injection molding machine.The diameter of the screw of the first injection molding machine is shown.The diameter of the screw of the second injection molding machine is shown. "VIA" indicates the injection speed of the first injection molding machine. "VIB" denotes the injection speed of the second injection molding machine. "VHA" denotes the dwell speed of the first injection molding machine. "VHB" denotes the dwell speed of the second injection molding machine.

When the correlation between the set value of the speed and the actually measured value of the speed is obtained between the first injection molding machine and the second injection molding machine, the set value of the speed is corrected so that the actually measured values are equal to each other in accordance with the above-described flow.

The molding condition correcting section 43 corrects the measurement conditions (S65). The measurement conditions include a measurement position, a VP switching position, and a screw rotation speed. In step S65, correction is performed by the following formulas (7) to (12).

DA (DB × ATB/ATA …) (formula 9)

DVP, A ═ DA + SA- (DB + SB-DVP, B). times.ATB/ATA … (equation 10)

DVP, A ═ DA + SA- (DB + SB-DVP, B). times.ATB/ATA … (equation 11)

nA. nB. times. DB/DA … (equation 12)

Equations (7) and (8) are the same as equations (3) and (4) described above. "DA" indicates the measurement position of the first injection molding machine. "DB" indicates the measurement position of the second injection molding machine. "DVP, a" indicates the VP switching position of the first injection molding machine. "DVP, B" indicates the VP switching position of the second injection molding machine. "SA" indicates the suck-back amount of the first injection molding machine. "SB" represents the suck-back amount of the second injection molding machine. "nA" represents the screw rotation speed of the first injection molding machine. "nB" represents the screw speed of the second injection molding machine.

The molding condition correcting section 43 corrects the dwell pressure and the dwell time (S66). In step S66, for example, as shown in fig. 8, the set value of the pressure of the second injection molding machine and the pressure of the mold inlet of the second injection molding machine based on the set value are referred to. Next, the set value of the pressure of the first injection molding machine is determined so that the pressures of the mold inlet ports of the first injection molding machine are equal to each other.

Through the above procedure, the corrected molding conditions under which the same quality of the molded product is obtained in the first injection molding machine and the second injection molding machine can be prepared. For example, when the mold clamping force is not corrected, the mold clamping force may be insufficient to cause burrs or the like. Further, for example, when the pressure is corrected in advance of the temperature, the time change of the pressure in the mold varies depending on the temperature, and therefore, accurate molding machine unique information cannot be obtained.

Fig. 12 is a table showing a correlation between the characteristic amount of the physical quantity obtained from the in-mold sensor and the molding condition for correction. The table in fig. 12 is simplified as follows. That is, in the items in the lateral direction of the table, the peak pressure is abbreviated as "Pmax", the peak mold temperature is abbreviated as "PTmmax", the peak resin temperature is abbreviated as "PTrmax", the maximum differential value of the pressure is abbreviated as "diff Pmax", the maximum differential value of the temperature is abbreviated as "diff Tmax", the integral value of the pressure in the injection step is abbreviated as "int P @ I", and the integral value of the pressure in the holding pressure step is abbreviated as "int P @ H". In the items in the vertical direction of the table, the pressure holding time IS abbreviated as "Thp", the pressure holding time IS abbreviated as "HP", the injection speed IS abbreviated as "IS", the VP switching position IS abbreviated as "VP", the resin temperature IS abbreviated as "Tr", and the mold temperature IS abbreviated as "Tm".

In fig. 12 (1), in the mold structure 60, the characteristic amount of the physical quantity is acquired by the in-mold sensor under various molding conditions. Fig. 12 (1) shows the correlation between the molding conditions and the feature values.

As the characteristic quantities, a peak pressure, a peak mold temperature, a peak resin temperature, a maximum differential value of the pressure, a maximum differential value of the resin temperature, a pressure integral value in the injection step, and a pressure integral value in the pressure holding step are obtained. The correlation coefficient between each molding condition and each characteristic amount is described as "Low" when it is less than 0.3, "Middle" when it is 0.3 or more and less than 0.7, and "High" when it is 0.7 or more.

As is clear from (1) in fig. 12, each feature amount has strong correlation with a plurality of molding conditions. Therefore, even if only the pressure is corrected with reference to the peak pressure, for example, different molded product qualities can be obtained unless other molding conditions are appropriately set. Thus, since the molding conditions have a correlation with each other, it is difficult to determine all the molding conditions at once.

Here, according to (1) in fig. 12, the peak resin temperature is set to "High" corresponding to the resin temperature in the correction molding condition, and the values in the other correction molding conditions are set to "Low". That is, it is known that the peak resin temperature has a strong correlation only with the resin temperature. Therefore, first, the resin temperature is determined so that the peak resin temperatures are equal to each other.

If the determined resin temperature is excluded from the table, it is (2) in fig. 12. As shown in (2) in fig. 12, the peak metal mold temperature has a strong correlation with only the metal mold temperature. Therefore, the mold temperature is also determined so that the peak mold temperature is equal.

If the determined mold temperature is excluded from the table, (3) in fig. 12 is obtained. As shown in (3) in fig. 12, the maximum differential value of the temperature has a strong correlation only with the injection speed. Therefore, as described above, the injection speed is determined so that the maximum differential values of the temperatures are equal to each other.

If the determined injection speed is excluded from the table, (4) in fig. 12 is obtained. As shown in (4) in fig. 12, the maximum differential value of the pressure has a strong correlation only with the VP switching position. Therefore, the VP switching position is determined so that the maximum differential values of the pressures are equal to each other.

If the determined VP switching position is excluded from the table, (5) in fig. 12 is obtained. As shown in (5) in fig. 12, the pressure integrated value in the injection process has a strong correlation only with the holding pressure. Therefore, the holding pressure is determined so that the pressure integrated values in the injection step are equal to each other. Then, the pressure holding time is determined so that the pressure integrated values in the pressure holding step are equal to each other.

As described above, the molding conditions uniquely determined by the above-described flow are determined in stages based on the feature values of the physical quantities obtained from the in-mold sensors, whereby the corrected molding conditions can be obtained by the shortest flow.

According to the present embodiment thus constituted, when molding is performed by another injection molding machine using a mold having production performance in a certain injection molding machine, optimum injection molding conditions for obtaining non-defective products can be obtained in a shorter time than before without depending on skilled operators, based on the production performance for obtaining non-defective products and molding machine unique information acquired in advance.

Further, according to the present embodiment, when optimizing the production plan as the manufacturing condition, it is not necessary to consider the combination of the injection molding machine and the metal mold, and therefore, a more efficient production plan can be made.

Further, in the present embodiment, the molding machine unique information acquired by a plurality of users is shared, and therefore, the number of users increases, and the number of times of acquiring the corrected molding conditions by flexibly using the molding machine unique information acquired by other users increases, and therefore, the number of steps for acquiring the molding machine unique information can be significantly reduced.

[ example 2]

The second embodiment will be described with reference to fig. 13. In the following embodiments including the present embodiment, the differences from the first embodiment will be mainly described. In the present embodiment, the molding condition correction system 4 of the injection molding system 1 is provided to the computer 10A on the network CN2, and the production management system 2 and the manufacturing execution system 3 are managed by the computer 8 having the user (E/U) side of the manufacturing plant 5. The factory-side computer 8 can obtain the corrected molding conditions by transmitting predetermined information to the computer 10A in which the molding condition correction system 4 is installed. As described above, the predetermined information includes, for example, the capacity of the first mold and the flow channel structure of the first mold. For example, a control mode (PID (Proportional-Integral-Differential) and a set value of the first injection molding machine), cad (computer Aided design) data of the first mold, and specification data and set data of the first injection molding machine may be used as predetermined information. The computer 8 on the plant side is an example of "predetermined computer". The computer 10A is an example of "another predetermined computer".

The present embodiment thus configured also obtains the same operational effects as the first embodiment. Further, according to the present embodiment, the molding condition correction system 4 provided by the computer 10A can be commonly used by the computers 8 of a plurality of users. Therefore, in the present embodiment, the correction molding conditions can be provided to the injection molding machines respectively provided in the plurality of factories by one molding condition correction system 4.

[ example 3]

The third embodiment will be described with reference to fig. 14. In this embodiment, the production management system 2, the manufacturing execution system 3, the molding condition correction system 4, and the manufacturing factory 5 described in fig. 1 are respectively realized by computers 10(2), 10(3), 10(4), 10(5), and are connected via a communication network CN 2.

The present embodiment thus configured also obtains the same operational effects as the first embodiment. In the present embodiment, the computers 10(2) to (5) are allocated to the systems 2 to 5, and thus, for example, the computers 10(5) of a plurality of manufacturing plants distributed can be managed by using the common production management system 2, the common manufacturing execution system 3, and the common molding condition correction system 4.

[ example 4]

The fourth embodiment will be described with reference to fig. 15 to 18. Fig. 15 is a functional block diagram of the injection molding system (or injection molding method) 1 according to the present embodiment. In the present embodiment, the molding condition correcting system 4 includes a flow analysis unit 45 and an analysis result storage unit 46 in addition to the above-described functions 41 to 44.

Fig. 16 shows a configuration example of a computer 10 that can be used to realize the injection molding system 1 of the present embodiment. The storage device 13 stores a computer program for realizing the flow analysis unit 45 and the analysis result storage unit 46 in addition to the computer program for realizing the functions 21, 31 to 36, 41 to 44, 51, 52, and 60.

In the present embodiment, the molding machine unique information learning unit 44 extracts an actual measurement value of the feature amount of the physical quantity from data (sensing data) from the sensor 57 provided in the injection molding mechanism 50 or the mold. The molding machine unique information learning unit 44 instructs the flow analysis unit 45 to perform analysis, and extracts an analysis value of the feature amount of the physical quantity from the analysis result recorded in the analysis result storage unit 46. The molding machine unique information learning unit 44 determines whether or not the actually measured value of the feature amount matches the analysis value, and if not, creates an injection point boundary condition in which the analysis condition is corrected, and instructs the flow analysis unit 45 to perform analysis again. When the actually measured value of the feature quantity matches the analyzed value, the molding machine unique information learning unit 44 stores the obtained injection point boundary condition as the machine difference information in the molding machine unique information storage unit 41.

Fig. 17 is a block diagram showing an example of a method of acquiring molding machine unique information of the injection molding machine according to the present embodiment. The method of acquiring molding machine unique information shown in fig. 17 is realized, for example, by combining a "sensor-equipped die" or a "sensor-embedded die" in which a sensor for measuring a predetermined physical quantity is provided at a predetermined position with a flow analysis that simulates the structure of the die.

First, in the above-described flow, an actual measurement value of a physical quantity of a predetermined portion in a mold is obtained by inputting arbitrary molding conditions 701 to an actual injection molding machine 702 (708). Then, from the analysis result 712 obtained by inputting the arbitrary molding conditions 701 to the flow analysis 711, an analysis value of a physical quantity of a predetermined portion in the mold is obtained (713). Here, the flow analysis 711 corresponds to the processing of the flow analysis unit 45. The analysis result 712 is recorded in the analysis result storage unit 46.

From the obtained actual measurement value and analysis value of the physical quantity, a feature quantity for comparing the actual measurement value and the analysis value is obtained (714), and it is determined whether or not the actual measurement value and the analysis value match (715). When the actually measured value does not match the analysis value (715: no), an injection point boundary condition is created in which the analysis condition is corrected so that the feature amount of the analysis value matches the feature amount of the actually measured value (716). Until the feature amount of the analyzed value matches the feature amount of the actually measured value, the processes from the flow analysis 711 to the creation 716 of the injection point boundary condition are repeatedly executed using the created correction molding condition.

When the feature value of the analyzed value matches the feature value of the actually measured value (715: yes), the obtained injection point boundary condition is associated with an arbitrary molding condition that is initially input, and recorded in the molding machine unique information database 710. The obtained feature amounts may be registered in the molding machine unique information database 710 in association with each other.

A method for creating the injection point boundary condition will be described with reference to fig. 18. Fig. 18 is a flowchart showing details of step 716 in fig. 17.

The molding machine unique information learning unit 44 corrects the resin temperature (7161). In step 7161, the molding machine unique information learning unit 44 sets the resin temperature of the injection point boundary condition so that the feature value of the actually measured value matches the feature value of the analyzed value. The molding machine unique information learning unit 44 refers to, for example, the maximum value of the resin temperature in the obtained feature amount, and performs optimization calculation using the resin temperature as a variable so that the difference between the actual measurement value and the analysis value is minimized.

The molding machine unique information learning unit 44 corrects the mold temperature (7162). In step 7162, the molding machine unique information learning unit 44 sets the mold temperature of the injection point boundary condition so that the feature value of the actually measured value matches the feature value of the analyzed value. For example, the molding machine unique information learning unit 44 refers to the maximum value of the mold temperature in the obtained feature values, and performs optimization calculation using, for example, the mold initial temperature, the refrigerant flow rate, the room temperature, and the like as variables so that the difference between the actual measurement value and the analysis value is minimized. However, since these parameters are obtained as actual measurement values, the calculation time can be shortened by inputting the actual measurement values from the beginning.

The molding machine unique information learning section 44 corrects the injection speed (7163). In step 7163, the injection speed of the injection point boundary condition is set so that the feature value of the measured value matches the feature value of the analyzed value. The molding machine unique information learning unit 44 refers to, for example, the maximum differential value of the resin temperature in the obtained feature amount, and performs optimization calculation using the injection speed as a variable so that the difference between the actual measurement value and the analysis value is minimized.

The molding machine unique information learning unit 44 corrects the measurement conditions (7164). In step 7164, the molding machine specific information learning unit 44 sets the VP switching position of the injection point boundary condition so that the feature amount of the actually measured value matches the feature amount of the analyzed value. The molding machine unique information learning unit 44 refers to, for example, the maximum differential value of the pressure in the obtained feature amount, and performs optimization calculation using the VP switching position as a variable so that the difference between the actual measurement value and the analysis value is minimized.

The molding machine unique information learning section 44 corrects the dwell pressure and the dwell time (7165). In step 7165, the molding machine specific information learning unit 44 sets the pressure holding and the pressure holding time of the injection point boundary condition so that the feature value of the actually measured value matches the feature value of the analyzed value. The molding machine unique information learning unit 44 refers to, for example, the maximum value and the integrated value of the pressure in the obtained feature amount, and performs optimization calculation using the pressure holding and the pressure holding time as variables so that the difference between the actual measurement value and the analysis value is minimized.

With the above-described flow, the injection point boundary condition in which the feature quantity of the actually measured value of the physical quantity and the feature quantity of the analyzed value coincide with each other at the predetermined portion in the mold can be obtained in a short time. For example, when the pressure is corrected before the temperature, the time change of the pressure in the mold varies depending on the temperature, and therefore, the pressure needs to be corrected again after the temperature is corrected, and the calculation time becomes long. In contrast, in the present embodiment, the temperature is corrected first, and therefore, the boundary condition of the injection point can be calculated in a short time.

The present embodiment thus configured also obtains the same operational effects as the first embodiment. Further, according to the present embodiment, an arbitrary portion in the mold can be set as the measurement portion without being restricted by the measurement portion. Further, even when the sensor is mounted on the gate portion or the runner portion, the pressure of the resin inlet can be obtained with higher accuracy in consideration of the pressure loss in the mold. Therefore, in the present embodiment, in order to acquire the molding machine unique information database 710, the existing mold can be used flexibly, and a mold having an arbitrary shape can be used. In the present embodiment, when the obtained molding machine unique information database 710 is used to correct the machine error of another mold, the correction can be performed with higher accuracy regardless of the structure of the mold. In addition, the present embodiment can construct the molding machine unique information database 710 regardless of the production performance described in the first embodiment.

[ example 5]

The fifth embodiment will be described with reference to fig. 19 to 21. The inventors found that the maximum open modulus and the residual open modulus obtained by the above experiments were related to the weight of the molded article, and were factors of the machine difference of the molding machine. By using this finding, when the machine error correction is performed, the open modulus is matched with the load in the production performance, so that the machine error correction can be performed with higher accuracy.

In the present embodiment, in the correction of the mold clamping force, in addition to the effective mold clamping force, the set mold clamping force, the necessary mold clamping force (force applied to the inside of the mold), and the mold opening modulus are registered in the molding machine unique information database 710 in association with each other. Fig. 19 is a block diagram showing an example of a method of acquiring molding machine unique information of the injection molding machine according to the present embodiment.

First, in the above-described flow, an actual measurement value of a physical quantity of a predetermined portion in a mold is obtained by inputting arbitrary molding conditions 701 to an actual injection molding machine 702 (708). From the obtained physical quantities, characteristic quantities are obtained (709). In the present example, the peak pressure, the maximum open modulus, and the residual open modulus are obtained as characteristic quantities.

Next, the force (load) applied to the inside of the metal mold is calculated based on the obtained peak pressure and the formula (1) (717). Alternatively, the flow analysis may be performed to obtain the pressure distribution in the die, and the load may be calculated by the formula (2).

Regression analysis is performed on the relationship between the maximum open modulus and the residual open modulus with respect to the obtained load and the set clamping force under the arbitrary molding condition 701 using an arbitrary model equation (718). As the model formula, for example, a curved surface polynomial model or the like can be used.

Fig. 20 is a graph showing the experimental value of the maximum opening modulus and the result of regression analysis based on the curved surface polynomial model for the set mold clamping force and the load of this example. For each set clamping force and holding pressure, the results of the load and the maximum open modulus are obtained and fitted well to the 3 rd order curved surface polynomial model shown in formula (13).

Z (A, B) ═ P00+ P10 xA + P01 xB + P20 xA ^2+ P11 xA xB + P02 xB ^2+ P30 xA ^3+ P21 xA ^2 xB + P12 xA x B ^2+ P03 xB ^3 … (formula 13)

Here, Z is a fitting function (here, maximum open modulus), a is a set mold clamping force, B is a load, and P00, P10, P01, P20, P11, P02, P30, P21, P12, and P03 are fitting coefficients. By fitting the experimental values using a regression expression such as the expression (13) to obtain a fitting coefficient, the maximum opening modulus specific to the molding machine can be predicted for an arbitrary set mold clamping force and load.

The obtained set mold clamping force and the load mold opening amount are recorded in the molding machine unique information database 710 in association with each other. At this time, the fitting coefficient and the model formula obtained by the regression analysis may be registered in the molding machine unique information database 710. Here, since the maximum open modulus has a correlation with the remaining open modulus, either one or both of the maximum open modulus and the remaining open modulus are registered in the database 710 as the open modulus.

The mold opening amount obtained by the "sensor-equipped mold" or the "sensor-embedded mold" is a value specific to the mold used, and the absolute amount differs depending on the structure of the mold. On the other hand, the rigidity is different depending on the structure of the molding machine, and it is considered that a difference in mold opening amount between the molding machines occurs when the same metal mold is used. Therefore, the mold opening amount obtained by using the same mold can be regarded as a parameter relatively representing the rigidity of the molding machine. That is, even if a database of the opening modulus obtained using different molds is used, the machine difference correction cannot be accurately performed. In this case, by standardizing the mold opening amount obtained in accordance with the rigidity of the mold, the tolerance correction using the database obtained using different molds can be performed.

Fig. 21 is a flowchart showing details of step S61 in fig. 11.

The molding condition correction unit 43 calculates the load in the input production result (S611). The molding condition correcting unit 43 refers to the molding machine unique information database 710 obtained by the method according to the fourth embodiment, for example, and obtains the injection point boundary condition of the second injection molding machine in the production result. Next, the molding condition correcting unit 43 performs flow analysis based on the acquired injection point boundary condition and the mold structure. From the obtained pressure distribution, the load is obtained by the formula (2). Alternatively, in the case where the cavity pressure is obtained in the production performance, the load may be calculated by the formula (1).

The molding condition correcting unit 43 corrects the set mold clamping force so that the mold opening amounts become equal to each other with respect to the obtained load (S612). Since the load loads in the first molding machine and the second molding machine are equalized by the machine difference correction, it is considered that the load of the second molding machine obtained in step S611 is also applied to the first molding machine. First, the molding condition correction unit 43 acquires a set value of the mold clamping force of the second injection molding machine and a maximum opening modulus with respect to the load from the molding machine unique information database 710. Next, the molding condition correcting unit 43 refers to the molding machine unique information database 710, and obtains the set mold clamping force of the first molding machine by inputting the obtained load and the maximum opening modulus.

The present embodiment thus configured also achieves the same operational effects as the first embodiment. Further, according to the present embodiment, the open modulus can be matched with the load in the production performance, and therefore, the machine difference correction can be performed with higher accuracy.

The present invention is not limited to the above embodiments, and includes various modifications. For example, the above-described embodiments are the ones explained in detail for easy understanding of the present invention, and are not limited to the embodiments having all the configurations explained. Further, a part of the structure of one embodiment may be replaced with the structure of another embodiment, and the structure of another embodiment may be added to the structure of one embodiment. In addition, a part of the configuration of each embodiment can be added, deleted, or replaced with another configuration.

[ example 6]

The sixth embodiment will be described with reference to fig. 22 to 26. In this embodiment, a method of correcting the amount of resin injected into the injection molding machine in accordance with the molding machine unique information will be described.

FIG. 1 is a functional block diagram of an injection molding system. The molding condition correction system 4A of the present embodiment will be explained. The molding condition correcting system 4A includes, as described in the first embodiment: a molding machine unique information storage unit 41, a molding machine unique information acquisition unit 42, a molding condition correction unit 43, and a molding machine unique information learning unit 44.

The molding machine unique information storage unit 41 has a function of storing molding machine unique information acquired in advance for each injection molding machine. The molding machine unique information storage section 41 of the present embodiment stores a correction value 411 for correcting the molding conditions of the measurement process as one of the molding machine unique information. The molding conditions (also referred to as measurement conditions) in the measurement step may include, for example: measurement position, velocity switching position, VP switching position.

The molding machine unique information learning unit 44 has a function of extracting a feature amount of the physical quantity based on data (sensing data) from a sensor 57 provided in the injection molding mechanism 50 or the mold, and storing the feature amount as the difference information in the molding machine unique information storage unit 41. The molding machine unique information learning unit 44 of the present embodiment includes: and a measurement condition learning unit 441 for learning the measurement conditions and registering the learned measurement conditions in the molding machine unique information storage unit 41.

As described later in fig. 23, the measurement condition learning unit 441 obtains a correction coefficient (regression coefficient) indicating a correlation between a cylinder extrusion amount (an extrusion amount determined by an extrusion distance from a measurement position to a VP switching position and a screw diameter, which is also referred to as a cylinder extrusion amount) and a volume (injection volume) of an obtained molded product by regression analysis by inputting a plurality of predetermined molding conditions to the injection molding machine.

Fig. 23 is a schematic diagram showing a method of creating a database of measurement steps and a method of correcting the measurement steps. In this example, the correlation between the cylinder extrusion amount (extrusion distance) and the injection volume was obtained by performing molding under a plurality of molding conditions under which the amount of resin injected into the mold was intentionally insufficient, and the regression coefficient as a correction value was obtained by performing regression analysis on the correlation. The insufficient resin amount indicates a state where a margin is left in the resin injection into the mold, and for example, a state where a cylinder position (also referred to as a relief amount) at the end of the pressure holding step is equal to the VP switching position. In the present embodiment, even in the case where the injection molding machine is changed, the cylinder extrusion amounts with equal injection volumes are calculated by using the regression coefficients.

In the state shown in the upper side of fig. 23, from the initial position x₀To VP switch position x_VPThe injection is performed while performing the speed control, and the movement of the screw 502 in the cylinder 505 is stopped by setting both the dwell time and the dwell pressure to 0.

In the state shown in the lower side of fig. 23, the buffer amount and VP switching position x are confirmed_VPAre equal. Thereby, the resin is injected into the metal mold 509 in a so-called short shot state.

Fig. 24 is a characteristic diagram showing a relationship between an injection volume and a cylinder extrusion amount. The horizontal axis represents cylinder extrusion amount and the vertical axis represents injection volume. From an initial position x₀The range to the VP switch position is the so-called under-filled state. Beyond the VP switch position, the state is filled. In the filled state, the molten resin is pressed into the metal mold 509, and therefore the actual value substantially matches the theoretical value. The theoretical value V of the injection volume is determined by equation (14).

V＝(D×πd²) /4 … (equation 14)

The actual value can be obtained by taking out the molded article 521 from the metal mold 509, measuring the weight thereof, and dividing the measured weight by the density of the resin.

Even if the extrusion amount is changed, the volume of the resin injected from the cylinder 505 into the cavity 520 in the die 509 (cylinder extrusion amount) and the volume of the molded article 521 molded by the resin (injection volume) should be equal to each other. However, actually, in the case of the so-called under-fill state, the theoretical value shown by the broken line in fig. 24 is different from the actual value shown by the solid line.

Fig. 25 is a block diagram showing a method of collecting a correction value (regression coefficient) for correcting information on a measurement process, which is one of molding machine unique information.

By inputting arbitrary molding conditions 701 to the actual injection molding machine 702, the physical quantity at a predetermined position in the mold 703 is obtained. The quality including the volume of the molded product 704 is obtained by product quality inspection 707.

The measurement condition learning unit 441 of the molding machine unique information learning unit 44 determines whether or not the buffer amount matches the VP switching position, as described with reference to fig. 23, based on the detection signal from the in-molding machine sensor 705 (711).

If the buffer amount does not match the VP switching position (711: no), the measurement condition learning unit 441 returns to block 701 to wait for a detection signal from the in-molding-machine sensor (705).

When the buffer amount matches the VP switch position (711: YES), the measurement condition learning unit 441 opens the mold and takes out the molded article, and measures the weight of the molded article (712). Since the density of the resin that forms the base of the molded product is known, the measurement condition learning unit 441 calculates the volume of the molded product from the weight and the density of the molded product (713).

The measurement condition learning unit 441 performs regression analysis on the actual measurement value of the injection volume obtained in block 713, and calculates a regression coefficient (714) as a correction value. The calculated regression coefficient is stored in the molding machine unique information storage unit 41 (715).

Fig. 26 is an explanatory diagram showing an example of a method of correcting a parameter related to a measurement process. In a first step S1 shown on the upper side of fig. 26, as described in fig. 25, the cylinder extrusion amount is changed, molding is performed under a condition called short shot, the correlation between the injection volume and the cylinder extrusion amount is obtained, and regression analysis is performed. Here, as shown in the formula (15) and the formula (16), calculation is performed for matching the measured values with the theoretical values for the molding machine a and the molding machine B.

V_m，A＝α_A·D_A(πd_A ²/4)，D_A＝x_0，A-x_VP，A… (equation 15)

V_m，A＝α_B·D_B(πd_B ²/4)，D_B＝x_0，B-x_VP，B… (equation 16)

Here, V_m: measured value of injection volume, d: screw diameter, D: cylinder extrusion amount, α: regression coefficient, x₀: measuring position, x_VP: VP switch position, A, B: and (4) a forming machine.

In the second step S2 shown on the lower side of fig. 26, the molding conditions relating to the measurement process are corrected as shown in formula (17), formula (18), and formula (19) by using the regression coefficient obtained in the first step S1.

x_0，B＝(d_A ²/d_B ²)x_0，A… (equation 17)

x_i，B＝x_0，B-(α_Ad_A ²/α_Bd_B ²)(x_0，A-x_i，A) … (formula 18)

x_VP，B＝x_0，B-(α_Ad_A ²/α_Bd_B ²)(x_0，A-x_VP，A) … (equation 19)

Here, x_i: the speed of the i-th speed switches the position.

According to the present embodiment thus configured, the amount (volume or weight) of resin at the time of injecting the resin into the metal mold is corrected based on the molding machine unique information, and therefore, the injection molding conditions can be corrected more appropriately than in the first embodiment.

Further, according to the present embodiment, the resin is injected into the mold in a so-called short shot state, the volume of the molded article is actually measured, and regression analysis is performed on the actually measured value, whereby the coefficient for correcting the resin amount can be accurately obtained in advance.

The present invention is not limited to the above-described embodiments, and includes various modifications. The above-described embodiments are described in detail to explain the present invention easily and understandably, and are not limited to having all the structures described. In addition, a part of the structure of one embodiment may be replaced with the structure of another embodiment. Note that the structure of another embodiment may be added to the structure of one embodiment. Further, other configurations may be added, deleted, or replaced for a part of the configurations of the embodiments.

The molding machine unique information may be, in addition to the molding machine unique information, the following information: and information obtained by correlating the set clamping force of the arbitrary molding condition with actual measurement values of mold opening amounts at other predetermined locations (predetermined positions) in a mold, wherein the information is obtained by using, as a load, an integrated pressure of a projected area of a cavity when an analyzed value obtained by analyzing a physical quantity at the predetermined location of the injection molding machine coincides with an actual measurement value of a physical quantity at a predetermined location in a mold attached to the injection molding machine.

All of the features described for the injection molding system can also be described as features of the molding condition correction system. The combinations of features disclosed in the present embodiment are not limited to the description of the claims.