阅读说明：本技术 注射成型机 (Injection molding machine ) 是由 森谷知宽 寺田真司 荻原俊辉 常深浩基 丸田阳介 浅井裕成 並木贵大 于 2020-11-27 设计创作，主要内容包括：本发明提供一种对于注射成型机而言能够实现更简单的结构的技术。本发明的一实施方式所涉及的注射成型机(10)具备：注射装置(300),被电力驱动；及合模装置(100),包含安装模具装置(800)的定模(810)的固定压板(110)及安装模具装置(800)的动模(820)的可动压板(120),并且液压驱动与闭模工序、合模工序及开模工序相关的动作。例如,合模装置(100)包含以直压式驱动可动压板(120)的液压缸(150)。并且,例如液压驱动合模装置(100)的液压回路(160)由闭合回路构成。(The invention provides a technology which can realize a simpler structure for an injection molding machine. An injection molding machine (10) according to an embodiment of the present invention includes: an injection device (300) driven electrically; and a mold clamping device (100) which includes a fixed platen (110) on which a fixed mold (810) of the mold device (800) is mounted and a movable platen (120) on which a movable mold (820) of the mold device (800) is mounted, and which hydraulically drives operations related to a mold closing process, a mold clamping process, and a mold opening process. For example, the mold clamping device (100) includes a hydraulic cylinder (150) that drives the movable platen (120) with a direct pressure. A hydraulic circuit (160) for hydraulically driving the mold clamping device (100) is formed of a closed circuit, for example.)

1. An injection molding machine is provided with:

an injection device driven by electric power; and

the mold clamping device comprises a fixed pressing plate for mounting a fixed mold of the mold device and a movable pressing plate for mounting a movable mold of the mold device, and hydraulically drives the actions related to the mold closing process, the mold clamping process and the mold opening process of the mold device.

2. The injection molding machine according to claim 1,

a hydraulic circuit for hydraulically driving the mold clamping device is formed by a closed circuit.

3. The injection molding machine according to claim 2,

the mold clamping device comprises a hydraulic cylinder which drives the movable pressure plate in a direct pressure mode.

4. The injection molding machine according to claim 3,

the mold clamping device includes a hydraulic pump for supplying hydraulic oil to the hydraulic cylinder and an electric motor for driving the hydraulic pump,

the hydraulic pump and the electric motor are disposed adjacent to the hydraulic cylinder.

5. The injection molding machine according to claim 4,

the hydraulic pump and the electric motor are disposed adjacent to each other on a side of the hydraulic cylinder and arranged in a mold opening/closing direction or a vertical direction.

6. The injection molding machine according to claim 4,

the hydraulic pump and the electric motor are arranged above or below the hydraulic cylinder and are arranged in a die opening/closing direction or a width direction.

7. The injection molding machine according to claim 5 or 6,

the hydraulic pump and the frame of the hydraulic cylinder are connected.

8. The injection molding machine according to any one of claims 3 to 7,

the mold clamping device comprises a tank for storing working oil,

the tank is disposed adjacent to the hydraulic cylinder.

Technical Field

The present application claims priority based on japanese patent application No. 2019-217086, applied on 11/29/2019. The entire contents of this japanese application are incorporated by reference into this specification.

The present invention relates to an injection molding machine.

Background

For example, an injection molding machine is known in which an injection device is electrically driven and a mold clamping device is hydraulically driven (see patent document 1).

Patent document 1: japanese patent No. 5921736

However, in the above-described injection molding machine, the mold opening and closing step of the mold is realized by a servomotor different from a hydraulic cylinder for realizing the mold closing step. Therefore, a structure may be complicated.

Disclosure of Invention

In view of the above problems, an object of the injection molding machine is to provide a technique that can realize a simpler configuration.

In order to achieve the above object, according to one embodiment of the present invention, there is provided an injection molding machine including:

an injection device driven by electric power; and

the mold clamping device comprises a fixed pressing plate for mounting a fixed mold of the mold device and a movable pressing plate for mounting a movable mold of the mold device, and hydraulically drives the actions related to the mold closing process, the mold clamping process and the mold opening process of the mold device.

Effects of the invention

According to the above embodiment, a technique that can realize a simpler structure for an injection molding machine can be provided.

Drawings

Fig. 1 is a diagram showing an example of an injection molding machine.

Fig. 2 is a diagram showing an example of an injection molding machine.

Fig. 3 is a diagram showing an example of a mold clamping device.

Fig. 4 is a diagram showing an example of a mold clamping device.

Fig. 5 is a diagram showing an example of a mold clamping device.

Fig. 6 is a diagram showing an example of a mold clamping device.

Fig. 7 is a diagram showing a 1 st example of the arrangement of the hydraulic pump and the servomotor.

Fig. 8 is a diagram showing a 2 nd example of the arrangement of the hydraulic pump and the servomotor.

Fig. 9 is a diagram showing a 3 rd example of the arrangement of the hydraulic pump and the servomotor.

Fig. 10 is a diagram showing a 4 th example of the arrangement of the hydraulic pump and the servomotor.

In the figure: 10-injection molding machine, 100-mold clamping device, 110-fixed platen, 120-movable platen, 140-connecting rod, 150-hydraulic cylinder, 151-cylinder body part, 152-piston part, 153-rod part, 154-cylinder closing part, 155-157-oil chamber, 160-hydraulic circuit, 161-hydraulic pump, 162-hydraulic tank (tank), 163-165-stop valve, 166-liquid charging valve, 170-servo motor, 300-injection device, 400-moving device, 700-control device, 701-CPU, 702-storage medium, 703-input interface, 704-output interface, 750-operation device, 760-display device.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings.

[ Structure of injection Molding machine ]

< injection molding machine >

Fig. 1 is a diagram showing a state at the end of mold opening of an injection molding machine according to an embodiment. Fig. 2 is a diagram showing a state of mold clamping of the injection molding machine according to the embodiment. In this specification, the X-axis direction, the Y-axis direction, and the Z-axis direction are directions perpendicular to each other. The X-axis direction and the Y-axis direction indicate the horizontal direction, and the Z-axis direction indicates the vertical direction. When the mold clamping device 100 is horizontal, the X-axis direction is the mold opening and closing direction, and the Y-axis direction is the width direction of the injection molding machine 10. The Y-direction negative side is referred to as an operation side, and the Y-direction positive side is referred to as an opposite side to the operation side.

As shown in fig. 1 to 2, the injection molding machine 10 includes a mold clamping device 100 that opens and closes a mold device 800, an injection device 300 that injects a molding material into the mold device 800, a moving device 400 that moves the injection device 300 forward and backward with respect to the mold device 800, a control device 700 that controls each component of the injection molding machine 10, and a frame 900 that supports each component of the injection molding machine 10. The injection molding machine 10 includes an ejector (not shown) that ejects a molded product molded by the mold apparatus 800 from the mold apparatus 800 (movable mold 820). The frame 900 includes a mold clamping device frame 910 that supports the mold clamping device 100 and an injection device frame 920 that supports the injection device 300. The mold clamping unit frame 910 and the injection unit frame 920 are provided on the base plate 2 via horizontal caster wheels 930. The control device 700 is disposed in the inner space of the injection device frame 920. Hereinafter, each constituent element of the injection molding machine 10 will be described.

< mold clamping device >

In the description of the mold clamping apparatus 100, the moving direction of the movable platen 120 (for example, the positive X-axis direction) when the mold is closed is set to the front side, and the moving direction of the movable platen 120 (for example, the negative X-axis direction) when the mold is opened is set to the rear side.

The mold clamping device 100 performs mold closing, pressure raising, mold clamping, pressure releasing, and mold opening of the mold device 800. The mold apparatus 800 includes a stationary mold 810, a movable mold 820, and a movable member 830 disposed to be movable in and out of the movable mold 820 (hollow portion).

The mold clamping device 100 is, for example, horizontal, and the mold opening and closing direction is horizontal. The mold clamping device 100 includes a fixed platen 110, a movable platen 120, a tie bar 140, a hydraulic cylinder 150, and the like.

The fixed platen 110 is fixed to the mold clamping unit frame 910. A fixed mold 810 is attached to a surface of the fixed platen 110 facing the movable platen 120.

The movable platen 120 is disposed to be movable in the mold opening/closing direction with respect to the mold clamping unit frame 910. A guide 101 for guiding the movable platen 120 is laid on the mold clamping unit frame 910. A movable mold 820 is attached to a surface of the movable platen 120 facing the fixed platen 110. The mold closing, pressure increasing, mold closing, pressure releasing, and mold opening of the mold apparatus 800 are performed by advancing and retracting the movable platen 120 with respect to the fixed platen 110.

The tie bar 140 connects the fixed platen 110 and a cylinder body 151 of the hydraulic cylinder 150 (see fig. 3 to 6) with a gap L therebetween in the mold opening and closing direction. A plurality of (e.g., 4) connecting rods 140 may be used. The plurality of tie bars 140 are arranged parallel to the mold opening and closing direction and extend according to the mold clamping force.

The hydraulic cylinder 150 is attached to the movable platen. The hydraulic cylinder 150 drives the movable platen 120 with a so-called direct pressure type, and moves the movable platen 120 in the mold opening and closing direction. The structure of the hydraulic cylinder 150, its driving mechanism, and its operation will be described in detail later (see fig. 3 to 6).

The mold clamping apparatus 100 performs a mold closing process, a pressure raising process, a mold clamping process, a pressure releasing process, a mold opening process, and the like under the control of the control device 700. The specific operation of the mold clamping device 100 corresponding to these steps will be described later (see fig. 3 to 6).

In the mold closing step, the hydraulic cylinder 150 (a piston portion 152 described later) is driven to advance the hydraulic cylinder 150 to the mold closing end position at a set moving speed, and the movable platen 120 is advanced to bring the movable mold 820 into contact with the fixed mold 810. The position and the moving speed of the hydraulic cylinder 150 are detected using, for example, a cylinder sensor. The cylinder sensor detects the telescopic position of the hydraulic cylinder 150, and transmits a signal indicating the detection result to the control device 700. Thus, the controller 700 can perform feedback control (position control of the hydraulic cylinder 150) on the position of the hydraulic cylinder 150 (movable platen 120) based on a signal indicating the detection result of the cylinder sensor in the mold closing step and the mold opening step described later.

The cylinder position detector for detecting the position of the hydraulic cylinder 150 and the cylinder movement speed detector for detecting the movement speed of the hydraulic cylinder 150 are not limited to the cylinder sensors, and conventional detectors can be used.

In the pressure increasing step, the hydraulic cylinder 150 is further driven to control the pressure of the hydraulic cylinder 150 to a predetermined pressure (hereinafter, "target clamping pressure"), and the clamping force is generated by increasing the pressure of the hydraulic cylinder 150. The pressure of the hydraulic cylinder 150 is detected using, for example, a pressure sensor (cylinder pressure sensor) provided in the hydraulic cylinder 150. The cylinder pressure sensor detects the pressure of a predetermined oil chamber (for example, the pressure of an oil chamber 155 described later) inside the hydraulic cylinder 150, and transmits a signal indicating the detection result to the control device 700. Thus, the control device 700 can perform feedback control (pressure control of the hydraulic cylinder 150) relating to the pressure of the hydraulic cylinder 150 based on a signal indicating the detection result of the cylinder pressure sensor in the pressure increasing step, and the mold clamping step and the pressure releasing step, which will be described later.

In the mold clamping process, the hydraulic cylinder 150 is driven to maintain the pressure of the hydraulic cylinder 150 at the target mold clamping pressure. In the mold clamping step, the mold clamping force generated in the pressure increasing step is maintained. In the mold clamping process, a cavity space 801 (see fig. 2) is formed between the movable mold 820 and the fixed mold 810, and the injection device 300 fills the cavity space 801 with a liquid molding material. The filled molding material is cured, thereby obtaining a molded article.

The number of the cavity spaces 801 may be 1 or more. In the latter case, a plurality of molded articles are obtained at the same time. An insert may be disposed in a part of the cavity space 801, and the molding material may be filled in another part of the cavity space 801. A molded article in which the insert and the molding material are integrally molded can be obtained.

In the pressure releasing step, the hydraulic cylinder 150 is driven to reduce the pressure of the hydraulic cylinder 150 from the target clamping pressure, thereby reducing the clamping force.

In the mold opening step, the hydraulic cylinder 150 is driven to retract the hydraulic cylinder 150 (piston portion 152) from the mold opening start position to the mold opening end position at a set moving speed, whereby the movable platen 120 is retracted to separate the movable mold 820 from the fixed mold 810. Then, the ejector ejects the molded product from the movable die 820. The mold opening start position and the mold closing end position may be the same position.

The setting conditions in the mold closing step, the pressure raising step, and the mold clamping step are set collectively as a series of setting conditions. For example, the moving speed, the position (including the mold closing start position, the moving speed switching position, the mold closing end position, and the mold clamping position), the pressure (including the target mold clamping pressure), the mold clamping force, and the like of the hydraulic cylinder 150 in the mold closing step and the pressure raising step are set as a series of setting conditions. The mold closing start position, the moving speed switching position, the mold closing end position, and the mold clamping position are arranged in this order from the rear side to the front side, and indicate the start point and the end point of a section in which the moving speed is set. The moving speed is set for each section. The moving speed switching position may be 1 or plural. The moving speed switching position may not be set. Only one or two of the mold clamping position, the target mold clamping pressure, and the mold clamping force may be set.

The setting conditions in the decompression step and the mold opening step are also set in the same manner. For example, the movement speed and the position (the mold opening start position, the movement speed switching position, and the mold opening end position) of the hydraulic cylinder 150 in the decompression step and the mold opening step are set as a series of setting conditions. The mold opening start position, the moving speed switching position, and the mold opening end position are arranged in this order from the front side to the rear side, and indicate the start point and the end point of a section in which the moving speed is set. The moving speed is set for each section. The moving speed switching position may be 1 or plural. The moving speed switching position may not be set. The mold opening start position and the mold closing end position may be the same position. The mold opening end position and the mold closing start position may be the same position.

Instead of the moving speed, position, etc. of the hydraulic cylinder 150, the moving speed, position, etc. of the movable platen 120 may be set. Instead of the position of the hydraulic cylinder 150 (for example, the mold clamping position) or the position of the movable platen 120, a target mold clamping pressure or a target mold clamping force may be set.

The mold clamping apparatus 100 of the present embodiment is a horizontal type in which the mold opening and closing direction is the horizontal direction, but may be a vertical type in which the mold opening and closing direction is the vertical direction.

< ejecting device >

In the explanation of the ejector, similarly to the explanation of the mold clamping device 100, the moving direction of the movable platen 120 (for example, the positive X-axis direction) when the mold is closed is set to the front side, and the moving direction of the movable platen 120 (for example, the negative X-axis direction) when the mold is opened is set to the rear side.

The ejector is attached to the movable platen 120 and advances and retreats together with the movable platen 120. The ejector device includes an ejector rod for ejecting a molded product from the mold device 800 and a drive mechanism for moving the ejector rod in the moving direction (X-axis direction) of the movable platen 120.

The ejector rod is in contact with a movable member 830 disposed to be movable forward and backward inside the movable mold 820, and can advance the movable member.

The drive mechanism includes, for example, an ejector motor and a motion conversion mechanism that converts a rotational motion of the ejector motor into a linear motion of the ejector rod. The motion conversion mechanism includes a screw shaft and a screw nut screwed to the screw shaft. Balls or rollers may be interposed between the screw shaft and the screw nut.

The ejection device performs the ejection process under the control of the control device 700. In the ejection process, the ejector advances the movable member 830 to eject the molded product.

The position and moving speed of the ejector rod are detected using, for example, an ejector motor encoder. The ejection motor encoder detects the rotation of the ejection motor, and transmits a signal indicating the detection result to the control device 700. The ejector rod position detector for detecting the position of the ejector rod and the ejector rod movement speed detector for detecting the movement speed of the ejector rod are not limited to the ejector motor encoder, and a conventional detector may be used.

< injection device >

In the explanation of the injection device 300, unlike the explanation of the mold clamping device 100 and the explanation of the ejector device 200, the moving direction of the screw 330 during filling (for example, the X-axis negative direction) is set to the front, and the moving direction of the screw 330 during metering (for example, the X-axis positive direction) is set to the rear.

The injection device 300 is provided on the slide base 301, and the slide base 301 is disposed to be movable forward and backward with respect to the injection device frame 920. The injection device 300 is disposed to be movable forward and backward with respect to the mold device 800. The injection device 300 is brought into contact with the mold device 800, and fills the cavity space 801 in the mold device 800 with the molding material. The injection device 300 includes, for example, a cylinder 310, a nozzle 320, a screw 330, a metering motor 340, an injection motor 350, and a pressure detector 360.

The cylinder 310 heats the molding material supplied from the supply port 311 to the inside. The molding material includes, for example, resin. The molding material is, for example, formed into a granular shape and supplied to the supply port 311 in a solid state. The supply port 311 is formed at the rear of the cylinder 310. A cooler 312 such as a water-cooled cylinder is provided on the outer periphery of the rear portion of the cylinder block 310. A heater 313 such as a band heater and a temperature detector 314 are provided on the outer periphery of the cylinder 310 in front of the cooler 312.

The cylinder 310 is divided into a plurality of regions in an axial direction (e.g., X-axis direction) of the cylinder 310. Heaters 313 and temperature detectors 314 are provided in the plurality of regions, respectively. The set temperatures are set for the respective regions, and the control device 700 controls the heater 313 so that the temperature detected by the temperature detector 314 becomes the set temperature.

The nozzle 320 is provided at the front end of the cylinder 310 and presses the mold apparatus 800. A heater 313 and a temperature detector 314 are provided on the outer periphery of the nozzle 320. The control device 700 controls the heater 313 so that the temperature detected by the nozzle 320 becomes the set temperature.

The screw 330 is rotatably and reciprocatingly disposed in the cylinder 310. When the screw 330 is rotated, the molding material is conveyed forward along the spiral groove of the screw 330. The molding material is gradually melted by heat from the cylinder 310 while being conveyed forward. As the liquid molding material is transported to the front of the screw 330 and accumulated in the front of the cylinder 310, the screw 330 is retracted. When the screw 330 is advanced, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320 and is filled in the mold apparatus 800.

A check ring 331 is attached to a front portion of the screw 330 to be movable forward and backward, and the check ring 331 serves as a check valve for preventing the molding material from flowing backward from the front to the rear of the screw 330 when the screw 330 is pushed forward.

When the screw 330 is advanced, the check ring 331 is pushed backward by the pressure of the molding material in front of the screw 330, and is retracted relative to the screw 330 to a closed position (see fig. 2) where the flow path of the molding material is blocked. This prevents backward flow of the molding material accumulated in front of the screw 330.

On the other hand, when the screw 330 is rotated, the check ring 331 is pushed forward by the pressure of the molding material conveyed forward along the spiral groove of the screw 330, and relatively moves forward with respect to the screw 330 to an open position (see fig. 1) for opening the flow path of the molding material. Thereby, the molding material is conveyed to the front of the screw 330.

The check ring 331 may be of a co-rotating type that rotates together with the screw 330 and a non-co-rotating type that does not rotate together with the screw 330.

In addition, the injection device 300 may have a driving source that advances and retracts the check ring 331 between the open position and the closed position with respect to the screw 330.

The metering motor 340 rotates the screw 330. The driving source for rotating the screw 330 is not limited to the metering motor 340, and may be, for example, a hydraulic pump or the like.

The injection motor 350 advances and retracts the screw 330. A motion conversion mechanism or the like that converts the rotational motion of the injection motor 350 into the linear motion of the screw 330 is provided between the injection motor 350 and the screw 330. The motion conversion mechanism includes, for example, a screw shaft and a screw nut screwed to the screw shaft. Balls, rollers, etc. may be provided between the screw shaft and the screw nut. The driving source for advancing and retracting the screw 330 is not limited to the injection motor 350, and may be, for example, a hydraulic cylinder.

The pressure detector 360 detects the force transmitted between the injection motor 350 and the screw 330. The detected force is converted into a pressure by the control device 700. The pressure detector 360 is provided in a force transmission path between the injection motor 350 and the screw 330, and detects a force acting on the pressure detector 360.

The pressure detector 360 transmits a signal indicating the detection result to the control device 700. The detection result of the pressure detector 360 is used for controlling and monitoring the pressure applied to the molding material by the screw 330, the back pressure against the screw 330, the pressure applied to the molding material from the screw 330, and the like.

The injection device 300 performs a metering process, a filling process, a pressure maintaining process, and the like under the control of the control device 700. The filling step and the pressure holding step may be collectively referred to as an injection step.

In the metering step, the metering motor 340 is driven to rotate the screw 330 at a predetermined rotation speed, and the molding material is conveyed forward along the spiral groove of the screw 330. With this, the molding material is gradually melted. As the liquid molding material is transported to the front of the screw 330 and accumulated in the front of the cylinder 310, the screw 330 is retracted. The rotational speed of the screw 330 is detected, for example, by using the metering motor encoder 341. The metering motor encoder 341 detects the rotation of the metering motor 340, and transmits a signal indicating the detection result to the control device 700. The screw rotation speed detector for detecting the rotation speed of the screw 330 is not limited to the metering motor encoder 341, and a conventional detector may be used.

In the metering step, the injection motor 350 may be driven to apply a set back pressure to the screw 330 in order to restrict the screw 330 from rapidly moving backward. The back pressure of the screw 330 is detected, for example, by a pressure detector 360. The pressure detector 360 transmits a signal indicating the detection result to the control device 700. When the screw 330 is retracted to the metering completion position and a predetermined amount of molding material is accumulated in front of the screw 330, the metering process is completed.

The position and the rotation speed of the screw 330 in the metering step are set as a series of setting conditions. For example, a measurement start position, a rotation speed switching position, and a measurement end position are set. These positions are arranged in order from the front side to the rear side, and indicate the start point and the end point of the section in which the rotation speed is set. The rotation speed is set for each interval. The number of the rotational speed switching positions may be 1 or plural. The rotational speed switching position may not be set. Further, the back pressure is set for each section.

In the filling step, the injection motor 350 is driven to advance the screw 330 at a predetermined moving speed, and the cavity space 801 in the mold apparatus 800 is filled with the liquid molding material accumulated in front of the screw 330. The position and moving speed of the screw 330 are detected using, for example, an injection motor encoder 351. The injection motor encoder 351 detects the rotation of the injection motor 350, and transmits a signal indicating the detection result to the control device 700. When the position of the screw 330 reaches the set position, switching from the filling step to the holding pressure step (so-called V/P switching) is performed. The position where the V/P switching is performed is also referred to as a V/P switching position. The set moving speed of the screw 330 can be changed according to the position, time, and the like of the screw 330.

The position and the moving speed of the screw 330 in the filling process are set as a series of setting conditions. For example, a filling start position (also referred to as an "injection start position"), a movement speed switching position, and a V/P switching position are set. These positions are arranged in order from the rear side to the front side, and indicate the start point and the end point of a section in which the moving speed is set. The moving speed is set for each section. The moving speed switching position may be 1 or plural. The moving speed switching position may not be set.

The upper limit value of the pressure of the screw 330 is set for each section in which the moving speed of the screw 330 is set. The pressure of the screw 330 is detected by a pressure detector 360. When the detection value of the pressure detector 360 is equal to or lower than the set pressure, the screw 330 advances at the set moving speed. On the other hand, when the detection value of the pressure detector 360 exceeds the set pressure, the screw 330 is advanced at a moving speed slower than the set moving speed so that the detection value of the pressure detector 360 becomes equal to or lower than the set pressure for the purpose of protecting the mold.

In the filling process, after the position of the screw 330 reaches the V/P switching position, the screw 330 may be stopped at the V/P switching position and then V/P switched. Immediately before the V/P switching, the screw 330 may be moved forward or backward at a very low speed instead of stopping the screw 330. The screw position detector for detecting the position of the screw 330 and the screw movement speed detector for detecting the movement speed of the screw 330 are not limited to the injection motor encoder 351, and a conventional detector can be used.

In the pressure retaining step, the injection motor 350 is driven to push the screw 330 forward, and the pressure of the molding material at the tip end portion of the screw 330 (hereinafter also referred to as "holding pressure") is held at a set pressure, and the molding material remaining in the cylinder 310 is pushed toward the mold apparatus 800. The molding material in the mold apparatus 800 can be supplemented by an insufficient amount due to cooling shrinkage. The holding pressure is detected, for example, using a pressure detector 360. The pressure detector 360 transmits a signal indicating the detection result to the control device 700. The set value of the holding pressure may be changed according to the elapsed time from the start of the pressure holding step. The holding pressure and the holding time for holding the holding pressure in the plurality of holding pressure steps can be set individually and can be set collectively as a series of setting conditions.

In the pressure retaining step, the molding material in the cavity space 801 in the mold apparatus 800 is gradually cooled, and at the end of the pressure retaining step, the entrance of the cavity space 801 is blocked by the solidified molding material. This state is called gate sealing, and prevents the backflow of the molding material from the cavity space 801. After the pressure holding step, the cooling step is started. In the cooling step, the molding material in the cavity space 801 is solidified. The metering step may be performed in the cooling step for the purpose of shortening the molding cycle time.

The injection device 300 of the present embodiment is of a coaxial screw type, but may be of a premolded type or the like. The injection device of the pre-molding system supplies the molding material melted in the plasticizing cylinder to the injection cylinder, and injects the molding material from the injection cylinder into the mold device. In the plasticizing cylinder, the screw is disposed to be rotatable and not to advance and retreat, or the screw is disposed to be rotatable and advance and retreat. On the other hand, the plunger is disposed to be movable forward and backward in the injection cylinder.

Further, the injection device 300 of the present embodiment is a horizontal type in which the axial direction of the cylinder 310 is the horizontal direction, but may be a vertical type in which the axial direction of the cylinder 310 is the vertical direction. The mold clamping device combined with the vertical injection device 300 may be vertical or horizontal. Similarly, the mold clamping device combined with the horizontal injection device 300 may be horizontal or vertical.

In this manner, in the present embodiment, the injection device 300 is electrically driven by the electric actuators such as the metering motor 340 and the injection motor 350. Accordingly, the injection device 300 can be relatively more responsive than when hydraulically driven in response to a control instruction from the control device 700. Accordingly, the injection molding machine 10 can achieve relatively excellent controllability of the injection device 300.

< mobile device >

In the explanation of the moving device 400, similarly to the explanation of the injection device 300, the moving direction of the screw 330 during filling (for example, the negative X-axis direction) is set to the front side, and the moving direction of the screw 330 during metering (for example, the positive X-axis direction) is set to the rear side.

The moving device 400 advances and retreats the injection device 300 with respect to the mold device 800. The moving device 400 presses the nozzle 320 against the mold device 800 to generate a nozzle contact pressure. The traveling apparatus 400 includes a hydraulic pump 410, a motor 420 as a driving source, a hydraulic cylinder 430 as a hydraulic actuator, and the like.

The hydraulic pump 410 has a 1 st port 411 and a 2 nd port 412. The hydraulic pump 410 is a pump that is rotatable in both directions, and generates hydraulic pressure by switching the rotation direction of the motor 420, sucking in hydraulic fluid (for example, oil) from one of the 1 st port 411 and the 2 nd port 412 and discharging the hydraulic fluid from the other port. The hydraulic pump 410 can also suck the hydraulic fluid from the tank and discharge the hydraulic fluid from any one of the 1 st port 411 and the 2 nd port 412.

The motor 420 operates the hydraulic pump 410. The motor 420 drives the hydraulic pump 410 by a rotation direction and a rotation torque according to a control signal from the control device 700. The motor 420 may be an electric motor or an electric servomotor.

The hydraulic cylinder 430 includes a cylinder main body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed to the injection device 300. The piston 432 divides the interior of the cylinder body 431 into a front chamber 435 as a 1 st chamber and a rear chamber 436 as a 2 nd chamber. The piston rod 433 is fixed to the stationary platen 110.

The front chamber 435 of the hydraulic cylinder 430 is connected to the 1 st port 411 of the hydraulic pump 410 via the 1 st flow path 401. The working fluid discharged from the 1 st port 411 is supplied to the front chamber 435 through the 1 st channel 401, and the injection device 300 is pushed forward. The injection device 300 advances and the nozzle 320 presses the stationary mold 810. The front chamber 435 functions as a pressure chamber that generates a nozzle contact pressure of the nozzle 320 by the pressure of the hydraulic fluid supplied from the hydraulic pump 410.

On the other hand, the rear chamber 436 of the hydraulic cylinder 430 is connected to the 2 nd port 412 of the hydraulic pump 410 via the 2 nd flow path 402. The working fluid discharged from the 2 nd port 412 is supplied to the rear chamber 436 of the hydraulic cylinder 430 through the 2 nd flow path 402, whereby the injection device 300 is pushed rearward. The injection device 300 is retracted and the nozzle 320 is separated from the stationary mold 810.

In the present embodiment, the moving device 400 includes the hydraulic cylinder 430, but the present invention is not limited thereto. For example, an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into linear motion of the injection device 300 may be used instead of the hydraulic cylinder 430.

< control device >

The control device 700 is constituted by a computer, for example, and as shown in fig. 1 to 2, includes a CPU (central processing Unit) 701, a storage medium 702 such as a memory, an input interface 703, and an output interface 704. The control device 700 performs various controls by causing the CPU701 to execute a program stored in the storage medium 702. The control device 700 receives a signal from the outside through the input interface 703 and transmits a signal to the outside through the output interface 704.

The control device 700 repeatedly performs a metering process, a mold closing process, a pressure raising process, a mold closing process, a filling process, a pressure maintaining process, a cooling process, a pressure releasing process, a mold opening process, an ejection process, and the like, thereby repeatedly manufacturing a molded product. A series of operations for obtaining a molded product, for example, an operation from the start of a metering process to the start of the next metering process is also referred to as "shot" or "molding cycle". Also, the time required for 1 shot is also referred to as "molding cycle time" or "cycle time".

The one-shot molding cycle includes, for example, a metering step, a mold closing step, a pressure raising step, a mold closing step, a filling step, a pressure maintaining step, a cooling step, a pressure releasing step, a mold opening step, and an ejection step in this order. The sequence here is the order in which the respective steps start. The filling step, the pressure holding step, and the cooling step are performed during the mold clamping step. The start of the mold clamping process may be made coincident with the start of the filling process. The end of the decompression process is consistent with the start of the mold opening process.

In addition, a plurality of steps may be performed simultaneously for the purpose of shortening the molding cycle time. For example, the metering step may be performed in the cooling step of the previous molding cycle, or may be performed during the mold clamping step. In this case, the mold closing step may be performed at the beginning of the molding cycle. Also, the filling process may be started in the mold closing process. The ejection process may be started in the mold opening process. When an opening/closing valve for opening/closing the flow path of the nozzle 320 is provided, the mold opening step may be started in the metering step. Even if the mold opening process is started in the metering process, the molding material does not leak from the nozzle 320 as long as the flow path of the nozzle 320 is closed by the opening and closing valve.

The one-shot molding cycle may include steps other than a metering step, a mold closing step, a pressure raising step, a mold closing step, a filling step, a pressure maintaining step, a cooling step, a pressure releasing step, a mold opening step, and an ejection step.

For example, after the pressure holding step is completed and before the metering step is started, a pre-metering suck-back step may be performed in which the screw 330 is retracted to a preset metering start position. The pressure of the molding material accumulated in front of the screw 330 can be reduced before the start of the metering process, and the screw 330 can be prevented from rapidly moving backward when the metering process is started.

After the metering step is completed and before the filling step is started, a post-metering suck-back step may be performed in which the screw 330 is retracted to a preset filling start position (also referred to as an "injection start position"). The pressure of the molding material accumulated in front of the screw 330 can be reduced before the filling process is started, and leakage of the molding material from the nozzle 320 before the filling process is started can be prevented.

Control device 700 is connected to an operation device 750 that receives an input operation by a user and a display device 760 that displays a display screen. The operation device 750 and the display device 760 are formed of, for example, a touch panel, and may be integrated. A touch panel as the display device 760 displays a display screen under the control of the control device 700. Information such as the settings of the injection molding machine 10 and the current state of the injection molding machine 10 can be displayed on the display screen of the touch panel. Further, an input operation unit such as a button or an input field for receiving an input operation by a user may be displayed on the display screen of the touch panel. The touch panel as the operation device 750 detects an input operation based on a user on the display screen and outputs a signal corresponding to the input operation to the control device 700. Thus, for example, the user can perform setting (including input of set values) of the injection molding machine 10 by operating an input operation unit provided on the display screen while checking information displayed on the display screen. The user can operate the injection molding machine 10 corresponding to the input operation unit by operating the input operation unit provided on the display screen. The operation of the injection molding machine 10 may be, for example, the operation (including the stop) of the mold clamping device 100, the ejector 200, the injection device 300, the moving device 400, and the like. The operation of the injection molding machine 10 may be switching of a display screen displayed on a touch panel as the display device 760.

Further, although the operation device 750 and the display device 760 of the present embodiment have been described as an example in which they are integrated as a touch panel, they may be provided separately. A plurality of operation devices 750 may be provided. The operation device 750 and the display device 760 are disposed on the operation side (Y-axis negative direction) of the mold clamping device 100 (more specifically, the fixed platen 110).

[ details of mold clamping device ]

Next, the details of the mold apparatus 100 will be described with reference to fig. 3 to 6 in addition to fig. 1 and 2.

Fig. 3 to 6 are diagrams showing an example of the mold clamping device 100 according to the present embodiment. Specifically, fig. 3 to 6 are diagrams showing the operating state of the mold clamping device 100 in each of the mold closing step, the pressure raising step, the mold clamping step, the pressure releasing step, and the mold opening step.

In fig. 3 to 6, the die apparatus 800 is not depicted.

< Structure of mold clamping device >

As shown in fig. 3 to 6, the mold clamping device 100 includes a fixed platen 110, a movable platen 120, a tie bar 140, a hydraulic cylinder 150, a hydraulic circuit 160, and a servo motor 170.

The hydraulic cylinder 150 includes a cylinder body 151, a piston 152, a rod 153, and a cylinder closing portion 154.

The cylinder body 151 is a fixed portion of the hydraulic cylinder 150. The cylinder body 151 is coupled to the other end of the coupling rod 140, one end of which is coupled to the fixed platen 110. Thereby, the cylinder main body 151 is fixed to the fixed platen 110 at a constant distance (interval L). The cylinder main body 151 is provided with a hollow portion having an open front end (end in the X-axis negative direction).

One of the cylinder main body 151 and the fixed platen 110 coupled via the coupling rod 140 is fixed to the mold clamping frame 910, and the other is movably mounted on the mold clamping frame 910. This allows the connecting rod 140 to be extended by the generation of the clamping force.

One end of the piston portion 152 is inserted into the interior (hollow portion) of the cylinder main body portion 151, and the other end is fixed to the movable platen 120. Thus, the piston portion 152 can move in the front-rear direction (X direction) by the action of the hydraulic oil supplied to and discharged from the cylinder main body portion 151, and as a result, the movable platen 120 fixed to one end thereof can be moved in the front-rear direction (X direction). The piston portion 152 is provided with a hollow portion that opens toward the inside of the cylinder body portion 151.

One end of the rod portion 153 is fixed to a closed end portion (i.e., an end portion in the X-axis negative direction) of the hollow portion of the cylinder main body portion 151, and the other end is inserted into the hollow portion of the piston portion 152. Thus, the rod 153 can move the piston section 152 forward (in the X-axis positive direction) by the action of the hydraulic oil supplied to the hollow section (oil chamber 157 described later) of the piston section 152. The rod 153 is provided with a hole extending in the axial direction from the other end side, which is inserted into the hollow portion of the piston 152.

The cylinder closing portion 154 closes the open end portion of the cylinder main body portion 151. The cylinder closing portion 154 is provided with a through hole through which the piston portion 152 can advance and retreat.

Oil chambers 155 to 157 are provided in the cylinder 150.

The oil chamber 155 is provided in a shape defined by an inner wall of the cylinder main body 151 and a distal end portion (one end portion) of the piston portion 152, in a closed end portion (end portion in the X-axis negative direction) of the hollow portion of the cylinder main body 151. Thus, the piston portion 152 can apply a mold clamping force to the movable platen 120 by the action of the hydraulic oil supplied to the oil chamber 155. The oil chamber 155 is provided with a supply/discharge port 155P for hydraulic oil.

The oil chamber 156 is provided in the open end portion (end portion in the positive X-axis direction) of the cylinder main body 151 so as to be defined by the inner wall of the cylinder main body 151, the inner wall of the cylinder closing portion 154, and the intermediate portion of the piston portion 152. Thus, the piston portion 152 can move backward (i.e., move in the X-axis negative direction) by the action of the hydraulic oil supplied to the oil chamber 156. The oil chamber 156 is provided with a supply/discharge port 156P for the working oil.

The oil chamber 157 is formed in a shape defined by an inner wall of the hollow portion of the piston portion 152 and a distal end portion of the rod portion 153. Thus, the piston portion 152 can advance (i.e., move in the X-axis positive direction) by the action of the hydraulic oil supplied to the oil chamber 157. The oil chamber 157 communicates with the hole of the rod 153, and a supply/discharge port 157P for the working oil with the oil chamber 157 is provided at the tip of the hole of the rod 153.

Hydraulic circuit 160 drives hydraulic cylinder 150. The hydraulic circuit 160 includes a hydraulic pump 161, a hydraulic tank 162, shutoff valves 163 to 165, a charge valve 166, and oil passages OL1 to OL 4.

The hydraulic pump 161 supplies hydraulic fluid to the hydraulic cylinder 150 and discharges hydraulic fluid from the hydraulic cylinder 150. The hydraulic pump 161 is driven by a servomotor 170. The hydraulic pump 161 is configured to be able to discharge hydraulic oil from one of the ports 161P1 and 161P2 and to suck hydraulic oil from the other port by switching the rotation direction of the servomotor 170. The hydraulic pump 161 is connected to the hydraulic tank 162 through an oil passage OL1, and can fill the hydraulic tank 162 with hydraulic oil or discharge the hydraulic oil to the hydraulic tank 162.

The port 161P1 is connected to the ports 155P and 157P via an oil passage OL 2. Specifically, the oil passage OL2 branches into oil passages OL2A and OL 2B. Port 161P1 is connected to oil chamber 155, which is port 155P, via oil passage OL2A, and to oil chamber 157, which is port 157P, via oil passage OL 2B. Accordingly, the hydraulic pump 161 can supply the hydraulic oil to at least one of the oil chambers 155 and 157 by discharging the hydraulic oil from the port 161P 1.

The port 161P2 is connected to the oil chamber 156 as the port 156P via an oil passage OL 3. Thus, the hydraulic pump 161 can supply the hydraulic oil to the oil chamber 156 by discharging the hydraulic oil from the port 161P 2.

The hydraulic pump 161 and the servomotor 170 may be accommodated in an integrated housing as an integrated drive unit (hereinafter, referred to as a "pump unit"), for example (see fig. 7 to 10). This enables the hydraulic pump 161 and the servomotor 170 to be arranged in an integrated manner, thereby achieving a reduction in size.

The hydraulic pump 161 and the hydraulic tank 162 may be connected by a steel pipe, for example. That is, the oil passage OL1 may be implemented by a steel pipe. Similarly, the hydraulic pump 161 and the cylinder main body 151 may be connected by a steel pipe, for example. That is, the oil passage OL2 (oil passages OL2A, OL2B) and the oil passage OL3 may be implemented by steel pipes. Thus, for example, as compared with the case where the oil passages OL1 to OL3 are realized by rubber hoses or the like, aging with time can be suppressed, and the maintenance cycle such as replacement and repair can be relatively extended.

When at least one of the oil passages OL1 to OL3 is implemented by a steel pipe, the stationary platen 110 and the cylinder main body 151 of the cylinder main body 151 may be fixed to the mold clamping frame 910, and the stationary platen 110 may be movably mounted on the mold clamping frame 910. This is because the fixed platen 110 moves on the mold clamping frame 910, and as described above, the extension of the tie bars 140 due to the mold clamping force can be allowed. This is because, when the cylinder main body 151 is moved, it is necessary to move the steel pipes corresponding to the oil passages OL1 to OL3 and heavy components such as the hydraulic pump 161 (pump unit) connected by the steel pipes as one unit, and there is a possibility that unnecessary energy is consumed. This is because the load is accumulated in the steel pipe connecting the cylinder main body 151 and the hydraulic pump 161 by the movement of the cylinder main body 151, and the life of the steel pipe is shortened or the steel pipe is damaged.

The hydraulic tank 162 (an example of a tank) stores hydraulic oil. The hydraulic tank 162 is connected to the hydraulic pump 161 through an oil passage OL 1. The hydraulic tank 162 is connected to the oil chamber 155, which is the port 155P, through an oil passage OL 4. As shown in fig. 1 and 2, the hydraulic tank 162 is disposed adjacent to the hydraulic cylinder 150 in the width direction (Y-axis direction).

The hydraulic tank 162 may be directly connected to the cylinder main body portion 151 via a charge valve 166, for example. That is, the oil passage OL4 is disposed in the housing of the charge valve 166 integrated with the hydraulic tank 162 and the cylinder main body 151. The hydraulic tank 162 may be connected by a steel pipe, for example. That is, the oil passage OL4 may be implemented by a steel pipe. Thus, for example, as compared with a case where the oil passage OL4 is realized by a rubber tube or the like, aging over time is suppressed, and a maintenance cycle such as replacement or repair can be relatively extended. In the former case, the cylinder main body 151, the hydraulic tank 162, and the charge valve 166 can be integrated. Therefore, the hydraulic circuit 160 and the servomotor 170 can be downsized.

When the hydraulic tank 162 is directly connected to the cylinder main body 151 via the charge valve 166 or when the oil passage OL4 is realized by a steel pipe, the stationary platen 110 and the cylinder main body 151 of the cylinder main body 151 may be fixed to the mold clamping frame 910 and the stationary platen 110 may be movably mounted on the mold clamping frame 910, as described above. This produces the same actions and effects as described above.

The shutoff valve 163 is provided in the oil passage OL 2A. The shutoff valve 163 switches between the communication state and the shutoff state of the oil passage OL2A under the control of the control device 700. Thus, for example, by setting the oil passage OL2A to the blocked state, the shutoff valve 163 can supply the hydraulic oil discharged from the port 161P1 of the hydraulic pump 161 only to the oil chamber 157 through the oil passage OL 2B.

The shutoff valve 164 is provided in the oil passage OL 2B. The shutoff valve 164 switches the communication state and the shutoff state of the oil passage OL2B under the control of the control device 700. Thus, for example, by setting the oil passage OL2B to the blocked state, the shutoff valve 164 can supply the hydraulic oil discharged from the port 161P1 of the hydraulic pump 161 only to the oil chamber 155 through the oil passage OL 2A. The shutoff valve 164 can retain the hydraulic oil in the oil chamber 157 by, for example, shutting off the oil passage OL 2B.

The shutoff valve 165 is provided in the oil passage OL 3. The shutoff valve 165 switches between a communication state and a shutoff state of the oil passage OL3 under the control of the control device 700. Accordingly, the shutoff valve 165 can discharge the hydraulic oil sucked into the hydraulic pump 161 from the port 161P1 to the hydraulic tank 162 without discharging the hydraulic oil from the port 161P2 by, for example, blocking the oil passage OL 3.

Hereinafter, the shutoff valves 163 to 165 are explained on the premise that they are normally open (i.e., normally open) and closed in response to a control instruction from the control device 700.

Charge valve 166 is provided in oil path OL 4. The charge valve 166 is normally closed (i.e., normally closed), and is opened by a pilot pressure supplied from a pilot line (not shown) branched from the oil passage OL 3.

The servomotor 170 operates under the control of the control device 700. Thus, the controller 700 can control the operation of the hydraulic pump 161 by controlling the servomotor 170.

The control device 700 controls the hydraulic pump 161 (the servomotor 170) and the shutoff valves 163 to 165 to control the flow of the hydraulic oil in the hydraulic circuit 160, thereby realizing the mold closing process, the pressure increasing process, the mold closing process, the pressure releasing process, and the mold opening process by the mold clamping device 100.

In this way, in the present embodiment, the mold clamping device 100 is hydraulically driven by the hydraulic cylinder 150. Specifically, the hydraulic cylinder 150 drives the movable platen 120 with a so-called direct pressure type. Thus, the mold clamping device 100 can be reduced in size in the X direction as compared with the case of the so-called toggle type. Therefore, the injection molding machine 10 can be downsized.

In the present embodiment, the hydraulic circuit 160 for hydraulically driving the mold clamping device 100 (hydraulic cylinder 150) is a closed circuit.

If the hydraulic circuit 160 is an open-loop circuit, a direction switching valve for switching the flow direction of the hydraulic oil needs to be provided in the hydraulic circuit 160. Also, it is necessary to provide a relatively large capacity hydraulic tank 162 in the hydraulic circuit 160. This is because it is necessary to supply the working oil of the hydraulic circuit 160 from the hydraulic tank 162. Therefore, the hydraulic circuit 160 may be large in size, and constituent elements thereof may not be arranged only in the vicinity of the hydraulic cylinder 150 to be driven. Therefore, for example, it may be necessary to dispose a hydraulic tank or the like in a space below the die apparatus 800. As a result, a conveying device or the like for receiving the molded product ejected from the mold apparatus 800 by the ejection device and conveying the molded product to another place cannot be disposed in the space below the mold apparatus 800, and there is a possibility that the convenience of the user is lowered.

In contrast, in the present embodiment, by configuring the hydraulic circuit 160 as a closed circuit, the size of the hydraulic circuit 160 can be reduced, and the components thereof can be integrated in a portion adjacent to the hydraulic cylinder 150. Specifically, as described above, the hydraulic tank 162 can be disposed adjacent to the hydraulic cylinder 150 (see fig. 1 and 2). As will be described later, a pump unit including the hydraulic pump 161, the servomotor 170, and the like can be disposed adjacent to the hydraulic cylinder 150. Therefore, for example, it is not necessary to arrange the components of the hydraulic circuit 160 in the space below the die apparatus 800, and user convenience can be improved.

< action of mold clamping device >

In the mold closing step, the control device 700 outputs a control instruction to the shutoff valve 163 to close the shutoff valve 163. Thereby, the oil passage OL2A of the oil passages OL2A, OL2B is in a cut-off state.

Then, the control device 700 operates the hydraulic pump 161 so as to output a control instruction to the servo motor 170 and discharge the hydraulic oil from the port 161P 1. As a result, as shown in fig. 3, the hydraulic pump 161 sucks the hydraulic oil from the oil passage OL3, discharges the hydraulic oil from the oil chamber 156, discharges the hydraulic oil to the oil passage OL2B, and can supply the hydraulic oil to the oil chamber 157 through the oil passage OL 2B. Therefore, the hydraulic cylinder 150 is extended so that the piston portion 152 projects forward from the hollow portion of the cylinder body portion 151, and the piston portion 152 (movable platen 120) moves from the mold closing start position to the mold closing end position.

In the pressure increasing step and the mold clamping step, the control device 700 outputs a control instruction to the shutoff valve 164 to close the shutoff valve 164. Accordingly, the oil passage OL2B of the oil passages OL2A and OL2B is in the blocked state, and the hydraulic oil in the oil chamber 157 is retained.

Then, the control device 700 operates the hydraulic pump 161 so as to output a control instruction to the servo motor 170 and discharge the hydraulic oil from the port 161P 1. As a result, as shown in fig. 4, the hydraulic pump 161 can discharge the hydraulic oil to the oil passage OL2A and supply the hydraulic oil to the oil chamber 155 through the oil passage OL 2A.

At the start of the pressure-increasing process, a predetermined pilot pressure is applied from the pilot line to the charge valve 166 by the action of the hydraulic oil flowing through the oil passage OL3 in the mold clamping process, and the charge valve 166 is opened. At the start of the pressure increasing step, the oil chamber 155 is in a negative pressure state. Therefore, as shown in fig. 4, the hydraulic oil is supplied from the hydraulic tank 162 to the oil chamber 155 through the oil passage OL 4.

By the action of the hydraulic oil supplied to the oil chamber 155, the piston portion 152 is further projected forward from the hollow portion of the cylinder main body portion 151, and the hydraulic cylinder 150 is further extended. Therefore, the piston section 152 (movable platen 120) moves further from the mold closing end position to the mold clamping position to generate a mold clamping force, and is maintained at the mold clamping position.

In the pressure release step, the control device 700 outputs a control instruction to the shutoff valves 164 and 165 to close the shutoff valves 164 and 165. Accordingly, the oil passage OL2B of the oil passages OL2A and OL2B is in the blocked state, and the hydraulic oil in the oil chamber 157 is retained. The oil passage OL3 is in the blocked state, and the hydraulic oil can be prevented from flowing into the oil chamber 156.

Then, the control device 700 operates the hydraulic pump 161 so as to output a control instruction to the servo motor 170 and draw in hydraulic oil from the port 161P 1. As a result, as shown in fig. 5, the hydraulic pump 161 sucks in hydraulic oil from the oil passage OL2A, discharges the hydraulic oil from the oil chamber 155, and discharges (discharges) the hydraulic oil to the hydraulic tank 162 through the oil passage OL 1. Therefore, the mold clamping force generated by the action of the hydraulic oil in the oil chamber 155 gradually decreases, and the piston portion 152 (movable platen 120) returns from the mold clamping position to the mold opening start position (mold closing end position).

In the mold opening step, the control device 700 outputs a control instruction to the shutoff valve 163, and the shutoff valve 163 is closed. Thereby, the oil passage OL2A of the oil passages OL2A, OL2B is in a cut-off state.

The control device 700 outputs a control instruction to the hydraulic pump 161 to operate the hydraulic pump 161 so as to suck the hydraulic oil from the port 161P1 and discharge the hydraulic oil from the port 161P 2. As a result, as shown in fig. 6, the hydraulic pump 161 sucks the hydraulic oil from the oil passage OL2B, discharges the hydraulic oil from the oil chamber 157, discharges the hydraulic oil to the oil passage OL3, and supplies the hydraulic oil to the oil chamber 156. The hydraulic pump 161 is charged with hydraulic oil from the hydraulic tank 162 through an oil passage OL 1. Therefore, the hydraulic cylinder 150 is contracted so that the piston portion 152 is inserted into the hollow portion of the cylinder body 151, and the piston portion 152 (the movable platen 120) is moved from the mold opening start position to the mold opening end position.

Then, a predetermined pilot pressure is applied from the pilot line to charge valve 166 by the action of the hydraulic oil flowing through oil passage OL3, and charge valve 166 is opened. Therefore, the hydraulic oil remaining in the oil chamber 155 is discharged to the hydraulic tank 162 through the oil passage OL4 in accordance with the contraction of the hydraulic cylinder 150.

In this manner, in the present embodiment, the operations of the mold clamping device 100 related to all the steps such as the mold closing step, the pressure raising step, the mold clamping step, the pressure releasing step, and the mold opening step are hydraulically driven by the hydraulic cylinder 150.

For example, when the operations related to the pressure increasing step, the mold clamping step, and the pressure releasing step are hydraulically driven and the operations related to the mold opening step and the mold closing step are electrically driven, the structure of the mold clamping device 100 may be complicated.

In contrast, in the present embodiment, the mold clamping device 100 is hydraulically driven by the hydraulic cylinder 150 to perform operations related to all the steps, thereby simplifying the components. Therefore, the mold clamping device 100 can be downsized.

[ concrete example of arrangement of Hydraulic Pump and servomotor ]

Next, a specific example of the arrangement of the hydraulic pump 161 and the servomotor 170 will be described with reference to fig. 7 to 10.

Fig. 7 to 10 are views showing examples 1 to 4 of the arrangement of the hydraulic pump 161 and the servomotor 170, respectively. In examples 1 to 4, the hydraulic pump 161 and the servomotor 170 are housed in an integrated housing and configured as an integrated drive unit (pump unit). A power transmission mechanism and the like mechanically connecting the hydraulic pump 161 and the servo motor 170 are housed in a housing between the hydraulic pump 161 and the servo motor 170.

As described above, the hydraulic circuit 160 is constituted by the closed circuit, and therefore the constituent elements of the hydraulic circuit 160 are simplified, and the hydraulic circuit 160 is relatively miniaturized. Therefore, in the present embodiment, the hydraulic pump 161, which is a main component of the hydraulic circuit 160, and the servomotor 170 that drives the hydraulic pump 161 can be disposed adjacent to the hydraulic cylinder 150.

As shown in fig. 7, in example 1, the hydraulic pump 161 and the servomotor 170 are disposed adjacent to each other below the hydraulic cylinder 150 and aligned in the width direction (Y-axis direction) of the injection molding machine 10. Specifically, hydraulic pump 161 and servo motor 170 are disposed at a relatively short interval downward from hydraulic cylinder 150.

The hydraulic pump 161 and the servomotor 170 are arranged such that the hydraulic pump 161 is disposed on the positive Y-axis side and the servomotor 170 is disposed on the negative Y-axis side in the width direction (Y-axis direction) of the injection molding machine 10. The pump unit including the hydraulic pump 161 and the servomotor 170 is disposed so that the center of the arrangement direction thereof substantially coincides with the center of the width direction of the injection molding machine 10.

As described above, the pump unit including the hydraulic pump 161 and the servomotor 170 can be fixed to the cylinder main body 151 via the oil passages OL2 and OL3 formed of steel pipes, for example. Further, a pump unit including the hydraulic pump 161 and the servo motor 170 may be fixed to the mold clamping frame 910.

Oil passages OL2, OL3 through which hydraulic oil flows are disposed between the hydraulic pump 161 and the hydraulic cylinder 150 so as to extend in the vertical direction (Z-axis direction).

Instead of being arranged in the width direction of the injection molding machine 10, the hydraulic pump 161 and the servomotor 170 may be arranged in the mold opening/closing direction (X-axis direction). Hydraulic pump 161 and servomotor 170 may be disposed at a relatively short interval upward from hydraulic cylinder 150. The arrangement order of the hydraulic pump 161 and the servo motor 170 in the width direction may be reversed. That is, the hydraulic pump 161 and the servomotor 170 may be arranged in any order in the width direction, and may be arranged in the die opening/closing direction in the same manner.

As shown in fig. 8, in example 2, the hydraulic pump 161 and the servomotor 170 are arranged adjacent to each other on the side of the hydraulic cylinder 150 (in the positive Y-axis direction) and aligned in the vertical direction (in the Z-axis direction). Specifically, the housing of the hydraulic pump 161 is coupled to (i.e., directly connected to) the outer peripheral surface of the housing of the hydraulic cylinder 150. Accordingly, it is not necessary to externally dispose the oil passages OL2, OL3 between the hydraulic pump 161 and the hydraulic cylinder 150, and the hydraulic circuit 160 can be further downsized.

The hydraulic pump 161 and the servo motor 170 are arranged vertically, the hydraulic pump 161 is arranged above, and the servo motor 170 is arranged below. The pump unit including the hydraulic pump 161 and the servomotor 170 is disposed such that the center of the arrangement direction thereof is offset downward from the center of the hydraulic cylinder 150 in the vertical direction.

The pump unit including the hydraulic pump 161 and the servomotor 170 is fixed to the housing of the hydraulic cylinder 150 at a housing portion corresponding to the hydraulic pump 161 at the upper end thereof. The pump unit including the hydraulic pump 161 and the servomotor 170 is further fixed to the mold clamping frame 910, for example, by a frame portion of the servomotor 170 corresponding to a lower end portion thereof, directly or via a bracket or the like.

Instead of being arranged adjacently in the Y-axis positive direction of hydraulic cylinder 150, hydraulic pump 161 and servomotor 170 may be arranged adjacently in the Y-axis negative direction. Instead of being arranged in the vertical direction, the hydraulic pump 161 and the servomotor 170 may be arranged in the die opening/closing direction (X-axis direction), that is, in the axial direction of the hydraulic cylinder 150. The hydraulic pump 161 and the servomotor 170 may be arranged in the opposite order in the vertical direction. That is, the hydraulic pump 161 and the servomotor 170 may be arranged in any order in the vertical direction, and may be arranged in the mold opening/closing direction in the same manner. Further, as in the case of example 1, the hydraulic pump 161 and the servomotor 170 may be disposed adjacent to the hydraulic cylinder 150 at a relatively short interval in the Y-axis positive direction or the Y-axis negative direction.

As shown in fig. 9, in example 3, the hydraulic pump 161 and the servomotor 170 are disposed adjacent to each other below the hydraulic cylinder 150 and aligned in the width direction (Y-axis direction) of the injection molding machine 10. Specifically, as in the case of example 2, the housing of the hydraulic pump 161 is coupled to (i.e., directly connected to) the outer peripheral surface of the housing of the hydraulic cylinder 150. As a result, the hydraulic circuit 160 can be further downsized as in the case of example 2.

The hydraulic pump 161 and the servomotor 170 are arranged such that the hydraulic pump 161 is disposed on the positive Y-axis side and the servomotor 170 is disposed on the negative Y-axis side in the width direction (Y-axis direction) of the injection molding machine 10. The pump unit including the hydraulic pump 161 and the servomotor 170 is disposed such that the center of the arrangement direction thereof is shifted in the Y-axis negative direction from the center of the injection molding machine 10 in the width direction.

The pump unit including the hydraulic pump 161 and the servomotor 170 may be fixed to the housing of the hydraulic cylinder 150 by a housing portion of the hydraulic pump 161. The pump unit including the hydraulic pump 161 and the servomotor 170 may be further fixed to the mold clamping frame 910 directly or via a bracket or the like, for example.

Instead of being disposed adjacent to the lower side of the hydraulic cylinder 150, the hydraulic pump 161 and the servomotor 170 may be disposed adjacent to the upper side of the hydraulic cylinder 150. The arrangement order of the hydraulic pump 161 and the servo motor 170 in the width direction may be reversed. That is, the hydraulic pump 161 and the servomotor 170 may be arranged in any order in the width direction.

As shown in fig. 10, in example 4, the hydraulic pump 161 and the servomotor 170 are disposed adjacent to each other below the hydraulic cylinder 150 and aligned in the mold opening/closing direction (X-axis direction) of the injection molding machine 10. Specifically, as in the case of example 2 and the like, the housing of the hydraulic pump 161 is coupled to (i.e., directly connected to) the outer peripheral surface of the housing of the hydraulic cylinder 150. As a result, the hydraulic circuit 160 can be further downsized as in the case of example 2 and the like.

The hydraulic pump 161 and the servomotor 170 are arranged such that the hydraulic pump 161 is disposed on the mold closing direction (X-axis positive direction) side and the servomotor 170 is disposed on the mold opening direction (X-axis negative direction) side of the injection molding machine 10 in the mold opening and closing direction (X-axis direction). The pump unit including the hydraulic pump 161 and the servomotor 170 is disposed so as to be projected from the tip end portion of the hydraulic cylinder 150 in the mold opening/closing direction (X-axis direction) of the injection molding machine 10.

The pump unit including the hydraulic pump 161 and the servomotor 170 may be fixed to the housing of the hydraulic cylinder 150 by a housing portion of the hydraulic pump 161. The pump unit including the hydraulic pump 161 and the servomotor 170 may be further fixed to the mold clamping frame 910 directly or via a bracket or the like, for example.

Instead of being disposed adjacent to the lower side of the hydraulic cylinder 150, the hydraulic pump 161 and the servomotor 170 may be disposed adjacent to the upper side of the hydraulic cylinder 150. The hydraulic pump 161 and the servomotor 170 may be arranged in the opposite order of the die opening and closing directions. That is, the hydraulic pump 161 and the servomotor 170 may be arranged in any order in the mold opening/closing direction.

By employing the hydraulic circuit 160 having a closed circuit in this manner, the constituent elements of the hydraulic circuit 160 are simplified as described above, and large components such as the hydraulic pump 161 and the servomotor 170 can be integrated at positions close to the hydraulic cylinder 150.

As shown in fig. 7 to 10, the hydraulic pump 161 and the servomotor 170 can be disposed in various ways in a range adjacent to the hydraulic cylinder 150. Therefore, the injection molding machine 10 can improve the degree of freedom in design, the degree of freedom in size, and the like.

[ Change and modification ]

The embodiments have been described above, but the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the spirit and scope described in the claims.