阅读说明：本技术 激光选区熔化成型控制系统 (Selective laser melting and forming control system ) 是由 申赛刚 邢月华 唱丽丽 于 2020-08-06 设计创作，主要内容包括：本发明提供一种激光选区熔化成型控制系统,包括：成型舱室；成型系统,具有至少一个基板；送粉系统；铺粉系统,具有至少一个刮刀,进行铺粉；激光光路系统；设置在所述成型舱室内部一侧的测距装置,所述测距装置被安装在一直线运动机构上,并可被驱动沿着X轴方向移动；设置在成型舱室内的挡板机构,所述挡板机构位于测距装置与基板之间,遮挡所述测距装置。本发明可有效地解决激光选区熔化设备同时打印多个零件过程中,由于单个零件变形、断裂或者翘曲等问题而导致整个加工平台上其他正在打印的零件都无法保质保量的完成打印任务的问题。(The invention provides a selective laser melting and forming control system, which comprises: a molding cabin; a molding system having at least one substrate; a powder feeding system; the powder spreading system is provided with at least one scraper for spreading powder; a laser optical path system; the distance measuring device is arranged on one side inside the forming cabin, is arranged on a linear motion mechanism and can be driven to move along the X-axis direction; the baffle mechanism is arranged in the forming cabin and is positioned between the distance measuring device and the substrate to shield the distance measuring device. The invention can effectively solve the problem that other printing parts on the whole processing platform can not finish the printing task with guaranteed quality and quantity due to the problems of deformation, fracture or warping of a single part and the like in the process of simultaneously printing a plurality of parts by the selective laser melting equipment.)

1. A selective laser melting control system, comprising:

a molding cabin;

a molding system having at least one substrate;

a powder feeding system;

the powder spreading system is provided with at least one scraper which is arranged to move along a powder spreading movement direction and used for spreading metal powder conveyed by the powder feeding system on the surface of the at least one substrate, and the powder spreading movement direction is defined as an X-axis direction; and

a laser optical path system configured to melt the laid metal powder on a substrate of the molding system according to a preset printing program;

wherein, the selective laser melting forming control system further comprises:

the distance measuring device is arranged on one side inside the forming cabin and is installed on a linear motion mechanism, and the distance measuring device is used for being driven to move to the position of the deformed part along the X-axis direction when the deformed part occurs, and detecting the distance between the distance measuring device and the deformed part so as to generate a Y-axis coordinate corresponding to the deformed part;

a control system configured to identify a part number that is deformed based on the X-axis-Y-axis coordinates;

the baffle mechanism is arranged in the forming cabin and is positioned between the distance measuring device and the substrate to shield the distance measuring device.

2. The selective laser melting system of claim 1 wherein the shutter mechanism is configured to have a first position in which it blocks the distance measuring device and a second position in which it exposes the distance measuring device, wherein the distance measuring device is configured to measure a distance to an object on a substrate.

3. The selective laser melting and forming control system as claimed in claim 2, wherein the baffle mechanism comprises a first motor and a baffle driven by the first motor, and the first motor is driven to rotate to drive the baffle to move so as to shield or expose the distance measuring device.

4. The selective laser melting and forming control system as claimed in claim 3, wherein the baffle is elongated and is correspondingly disposed along the length of the linear motion mechanism.

5. The selective laser melting system of claim 1, wherein the linear motion mechanism includes a fixed portion and a moving portion, and the distance measuring device is provided on the moving portion and moves in the X-axis direction in synchronization with the moving portion when driven.

6. The selective laser melting system as claimed in any one of claims 1 to 5, wherein the powder spreading system further comprises a pressure sensor for sensing the resistance of the blade during powder spreading.

7. The selective laser melting system of claim 6, wherein the control system is configured to:

in response to the resistance received by the pressure sensor at the time T1 exceeding a set threshold value, controlling the baffle mechanism to expose the distance measuring device, and driving the distance measuring device to move along the X-axis direction to the X-axis position coordinate position of the powder laying system at the time T1;

and controlling the distance measuring device to detect the distance between the distance measuring device and the deformed part, feeding the distance to a control system, and generating a Y-axis coordinate corresponding to the deformed part.

8. The selective laser melting and forming control system as claimed in claim 7, wherein the control system controls the distance measuring device to restore the initial position and is shielded by a baffle mechanism.

9. The selective laser melting system of claim 7 wherein the control system controls the increase of the overload current value of the powder application system so that the powder application system can move past the location of the deformed part and re-apply a uniform powder on the substrate.

10. The selective laser melting and forming control system as claimed in claim 7, wherein the control system controls to delete the part number which is deformed and complete the subsequent forming task of the rest parts.

Technical Field

The invention relates to the technical field of additive manufacturing, in particular to a selective laser melting additive manufacturing printing technology, and specifically relates to a selective laser melting molding control system and a selective laser melting molding control method.

Background

As one of the means for manufacturing metal material additive, the laser selective melting (SLM) technology has the advantages of not requiring mold opening, digitalization, greening, and theoretically forming any spatial form member, compared to the conventional manufacturing form, and is gaining favor in the fields of aerospace, automobile, medical treatment, mold, and the like, and is beginning to be tried and applied.

Because the selective laser melting equipment is relatively expensive and the cost of metal powder is high, when the technology is adopted to manufacture metal parts, parts needing to be processed can be placed on a limited printing forming platform as many as possible, so that the printing cost is reduced.

However, the more the number or the types of the metal parts to be molded are placed on the processing platform, the greater the risk of failure in the printing process; this is because when a plurality of metal parts print, if certain part takes place to support fracture, warpage scheduling problem, at this moment, spreads the powder scraper and is blocked by the part that warp, prints and pause, and equipment warning waits for manual handling, can cause even to spread the powder scraper and damage, and the shaping part is impaired, processing failure.

Disclosure of Invention

The invention aims to provide a selective laser melting forming control system and a selective laser melting forming control method aiming at the problems in the prior art, and effectively solves the problem that other printed parts on the whole processing platform cannot complete the printing task with guaranteed quality and quantity due to the problems of deformation, fracture or warping of a single part and the like in the process of simultaneously printing a plurality of parts by selective laser melting equipment.

To achieve the above object, according to a first aspect of the present invention, there is provided a selective laser melting control system, comprising: a molding cabin; a molding system having at least one substrate; a powder feeding system; the powder spreading system is provided with at least one scraper which is arranged to move along a powder spreading movement direction and used for spreading metal powder conveyed by the powder feeding system on the surface of the at least one substrate, and the powder spreading movement direction is defined as an X-axis direction; and a laser optical path system configured to melt the laid metal powder on a substrate of the molding system according to a preset printing program; wherein, the selective laser melting forming control system further comprises: the distance measuring device is arranged on one side inside the forming cabin, is arranged on a linear motion mechanism and can be driven to move along the X-axis direction; the baffle mechanism is arranged in the forming cabin and is positioned between the distance measuring device and the substrate to shield the distance measuring device.

Preferably, the baffle mechanism is arranged to have a first position in which it blocks the distance measuring device, and a second position in which it is exposed, in which it is arranged to measure a distance to an object on the substrate.

Preferably, the baffle mechanism comprises a first motor and a baffle driven by the first motor, and the first motor is driven to rotate to drive the baffle to move up and down or turn over so as to shield or expose the distance measuring device.

Preferably, the baffle is in a long strip shape and is correspondingly arranged along the length direction of the linear motion mechanism.

Preferably, the linear motion mechanism includes a fixed portion and a moving portion, and the distance measuring device is provided on the moving portion and moves in the X-axis direction in synchronization with the moving portion when driven.

Preferably, the powder spreading system further comprises a pressure sensor for sensing the resistance force applied to the scraper in the powder spreading process.

Preferably, the selective laser melting system further comprises a control system configured to:

in response to the resistance received by the pressure sensor at the time T1 exceeding a set threshold value, controlling the baffle mechanism to expose the distance measuring device, and driving the distance measuring device to move along the X-axis direction to the X-axis position coordinate position of the powder laying system at the time T1;

controlling the distance measuring device to detect the distance between the distance measuring device and the deformed part, feeding the distance to a control system, and generating a Y-axis coordinate sum corresponding to the deformed part;

and the control system identifies the part number which is deformed according to the X-axis-Y-axis coordinate.

Preferably, the control system controls the distance measuring device to return to the initial position and controls the baffle mechanism to restore the shielding of the distance measuring device.

Preferably, the control system controls to increase the overload current value of the powder laying system, so that the powder laying system can move past the position of the deformed part and lay uniform powder on the substrate again.

Preferably, the control system controls to delete the part number which is deformed and complete the subsequent forming tasks of the rest parts.

According to a second aspect of the object of the present invention, there is also provided a selective laser melting molding control method, comprising the steps of:

step 1, powder is paved on a substrate layer by layer according to a preset printing program, and a laser light path system is controlled to melt paved metal powder on the substrate of a forming system according to the preset program;

step 2, detecting resistance borne by a scraper of the powder paving system in the powder paving process, and feeding back the position coordinate of the current X axis of the powder paving system to the control system when the detected resistance borne by the scraper is larger than a set threshold value;

step 3, controlling the baffle mechanism to expose the distance measuring device, and driving the distance measuring device to move to the X-axis position coordinate position of the powder spreading system at the T1 moment along the X-axis direction;

step 4, the distance measuring device detects the distance between the distance measuring device and the deformed part and feeds the distance back to the control system to generate a Y-axis coordinate corresponding to the deformed part;

step 5, identifying the part number which is deformed according to the X-axis-Y-axis coordinate;

step 6, controlling and improving the overload current value of the powder paving system, enabling the powder paving system to move past from the position of the deformed part, and paving uniform powder on the substrate again; and the control system deletes the serial number of the deformed part and completes the subsequent forming tasks of other parts.

Preferably, the aforementioned method further comprises the steps of:

and after identifying the serial number of the deformed part, controlling the distance measuring device to recover the initial position and shielding the part through a baffle mechanism.

According to the technical scheme, the selective laser melting forming control system and the selective laser melting forming control method have the advantages that in the SLM forming process of a plurality of parts, when a certain part is warped and deformed, the powder spreading system moves to the position, and the part stops at the position when the resistance is larger than a set value; feeding back the position coordinates of the X axis of the movement of the powder laying system to the control system; the control system moves the high-precision laser ranging sensor to an X-axis position coordinate which is the same as the current position of the powder spreading system, detects the distance between the high-precision laser ranging sensor and the deformed part, feeds the distance back to the control system, and generates a Y-axis coordinate of the deformed part, so that the control system can identify the serial number of the specific deformed part; then removing deformed parts and reprinting: the high-precision laser ranging sensor returns to the initial position, and the second motor drives the baffle to move downwards, so that the high-precision laser ranging sensor is isolated from the forming cabin again; and simultaneously, the control system improves the resistance value of the powder spreading system, so that the powder spreading system can move from the position of the deformed part, uniform powder is re-spread on the forming substrate, and the control system deletes the second part and completes the subsequent forming tasks of other parts.

Compared with the prior art, the multi-part SLM forming process is automatically controlled, when part deformation is detected, positioning detection and crossing are carried out, execution of the whole printing task cannot be hidden due to printing deformation of individual parts, and success rate and printing efficiency of simultaneous forming and processing of a plurality of parts are improved; simultaneously, through detecting the deformation part, the adjustment scraper spreads the overload current of tolerance of powder mechanism and crosses, prevents to the damage of scraper system, improves the life of spreading the powder system.

In a preferred scheme, the shielding mechanism in the direction synchronous with the range finder is arranged, shielding is performed during printing and is separated by the baffle, metal dust in a forming cabin is prevented from damaging the high-precision laser ranging sensor, the baffle is moved away when positioning and detecting are needed, the deformation part can be conveniently moved to be positioned, the deformation part can be positioned only by moving to the X position of the powder spreading system, and then the Y-direction position can be positioned by detecting the distance between the range finder and the deformation part, so that the detection and positioning of the deformation part are realized.

It should be understood that all combinations of the foregoing concepts and additional concepts described in greater detail below can be considered as part of the inventive subject matter of this disclosure unless such concepts are mutually inconsistent. In addition, all combinations of claimed subject matter are considered a part of the presently disclosed subject matter.

The foregoing and other aspects, embodiments and features of the present teachings can be more fully understood from the following description taken in conjunction with the accompanying drawings. Additional aspects of the present invention, such as features and/or advantages of exemplary embodiments, will be apparent from the description which follows, or may be learned by practice of specific embodiments in accordance with the teachings of the present invention.

Drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Embodiments of various aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a laser selective melting shaping control system in accordance with an exemplary embodiment of the present invention.

FIG. 2 is a schematic illustration of a normal print state of a laser selective melt-formed part in accordance with an exemplary embodiment of the present invention.

FIG. 3 is a schematic illustration of selective laser melting forming with partial part deformation according to an exemplary embodiment of the present invention.

Detailed Description

In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.

In this disclosure, aspects of the present invention are described with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be appreciated that the various concepts and embodiments described above, as well as those described in greater detail below, may be implemented in any of numerous ways, as the disclosed concepts and embodiments are not limited to any one implementation. In addition, some aspects of the present disclosure may be used alone, or in any suitable combination with other aspects of the present disclosure.

Referring to fig. 1-3, a selective laser melting and forming control system according to an exemplary embodiment of the present invention includes a circulating filter system 1, a laser optical path system 2, a forming chamber 3, a distance measuring device 4, a powder returning system 5, a forming system 7, a powder spreading system 8, a powder feeding system 9, and a control system 10. The molding system 7 has at least one substrate 13.

In fig. 1-3, reference numeral 6 denotes a laser beam, reference numeral 11 denotes a formed part, and reference numeral 12 denotes a loose powder.

And the powder feeding system 9 is used for carrying out powder feeding treatment in the additive manufacturing process and conveying metal powder.

And the powder spreading system 8 is provided with at least one scraper which is arranged to move along the powder spreading movement direction and is used for spreading the metal powder conveyed by the powder feeding system 9 on the surface of at least one substrate 13. In the embodiment of the present invention, the powder laying movement direction is defined as the X-axis direction.

And the laser light path system 2 is arranged above the forming cabin and is used for melting and paving metal powder on a substrate of the forming system according to a preset printing program.

Referring to fig. 1 and 2, in the normal printing and forming process, the control system 10 controls powder with a preset layer thickness height in the powder feeding system to be uniformly laid on a substrate of the forming system through a scraper of the powder laying system, then controls the circulating filter system 1 to remove oxygen from the forming cabin, and controls the laser optical path system to melt metal powder on the substrate of the forming system according to a preset program to form a part when the oxygen content is lower than a preset value.

With reference to the drawings, the selective laser melting control system of the present invention further includes: a distance measuring device 4, in particular a high-precision laser distance measuring sensor, is arranged on one side inside the molding chamber, is mounted on a linear movement mechanism and can be driven to move along the X-axis direction.

Preferably, the linear motion mechanism comprises a moving part and a fixed part, and after being driven, the moving part can continuously and uniformly move relative to the fixed part. The distance measuring device is provided on the moving portion and moves in the X-axis direction in synchronization with the moving portion when driven.

In some embodiments, the linear motion mechanism may be a linear motor, the distance measuring device is fixed on the motion part, and the fixed part is fixed in the molding chamber and is arranged lengthwise along the X-axis direction.

In other embodiments, for example, as shown in fig. 1 and 2, the linear motion mechanism is implemented by combining a rotary motor with a linear transmission mechanism, for example, the linear transmission mechanism is implemented by using a screw rod and a threaded sleeve structure, the screw rod is a fixed part, is supported in the X-axis direction in the molding chamber, and can be rotationally driven by a second motor 14, the threaded sleeve is sleeved on the screw rod and serves as a moving part, the distance measuring device is fixed on the threaded sleeve, and when the second motor moves, the threaded sleeve is driven to move along the X-axis direction, so as to drive the distance measuring device to synchronously move.

The second motor 14 may be a high precision stepper motor in particular.

Referring to fig. 2, a baffle mechanism is further disposed in the molding chamber, and the baffle mechanism is located between the distance measuring device 4 and the substrate 13 to shield the distance measuring device. Preferably, when the distance measuring device is in the initial position, the distance measuring device is shielded by the shielding device so as to separate the distance measuring device from the metal powder and prevent the dust in the forming cabin from damaging the high-precision laser distance measuring sensor.

As shown in fig. 2, the shutter mechanism is configured to be driven by the driving mechanism to be turned upside down or moved up and down. For example, in some embodiments, the shutter mechanism is configured to have a first position in which it blocks the ranging device, and a second position in which it is exposed, in which it is configured to range the object (printed part) on the substrate 13.

Preferably, the baffle mechanism comprises a first motor 15 and a baffle 16 driven by the first motor, the first motor can adopt a rotating motor, and the rotating motor is driven to rotate to drive the baffle to move up and down or turn over so as to shield or expose the distance measuring device.

Referring to fig. 2 and 3, the baffle 16 is in a long strip shape and is correspondingly arranged along the length direction of the linear motion mechanism, so as to more conveniently protect the laser ranging sensor.

According to a development of the invention, in the preferred embodiment, the dusting system 8 also comprises a pressure sensor for sensing the resistance to which the scraper is subjected during dusting. The pressure sensor is arranged to be connected to the control system 10, which determines, on the basis of the pressure variations detected by the pressure sensor, that the part in this position is deformed, thus staying in this position when the resistance to which the doctor blade is subjected is greater than a set threshold value, and feeding back its X-axis position coordinates to the control system 10.

In some embodiments, as shown in fig. 2 and 3, in response to the resistance received by the pressure sensor at time T1 exceeding the set threshold, the control system 10 controls the blocking mechanism to expose the distance measuring device 4 (e.g., a laser distance measuring sensor), and drives the distance measuring device 4 to move along the X-axis direction to the X-axis position coordinate position of the powder spreading system at time T1. As in fig. 3, reference numeral 17 denotes a part deformation position.

When the movement is in place, the control system 10 controls the distance measuring device to detect the distance between the distance measuring device and the deformed part, and feeds the distance to the control system to generate the Y-axis coordinate corresponding to the deformed part.

Thus, control system 10 may identify the part number that is deformed based on the X-Y coordinates.

Preferably, the control system controls the distance measuring device 4 to return to the initial position and controls the shutter mechanism to restore the occlusion of the distance measuring device 4.

Based on the detected and identified part number where the deformation occurs, the control system 10 may control the increase of the overload current value of the powder placement system so that the powder placement system can move past the deformed part location and re-place a uniform powder on the substrate. Meanwhile, the control system controls and deletes the serial number of the deformed part and completes the subsequent forming tasks of other parts.

With reference to the foregoing embodiments and examples shown in the drawings, the present invention further discloses a selective laser melting forming control method, which includes the following steps:

step 1, powder is paved on a substrate layer by layer according to a preset printing program, and a laser light path system is controlled to melt paved metal powder on the substrate of a forming system according to the preset program;

step 2, detecting resistance borne by a scraper of the powder paving system in the powder paving process, and feeding back the position coordinate of the current X axis of the powder paving system to the control system when the detected resistance borne by the scraper is larger than a set threshold value;

step 3, controlling the baffle mechanism to expose the distance measuring device, and driving the distance measuring device to move to the X-axis position coordinate position of the powder spreading system at the T1 moment along the X-axis direction;

step 4, the distance measuring device detects the distance between the distance measuring device and the deformed part and feeds the distance back to the control system to generate a Y-axis coordinate corresponding to the deformed part;

step 5, identifying the part number which is deformed according to the X-axis-Y-axis coordinate;

step 6, controlling and improving the overload current value of the powder paving system, enabling the powder paving system to move past from the position of the deformed part, and paving uniform powder on the substrate again; and the control system deletes the serial number of the deformed part and completes the subsequent forming tasks of other parts.

Preferably, the aforementioned method further comprises the steps of:

and after identifying the serial number of the deformed part, controlling the distance measuring device to recover the initial position and shielding the part through a baffle mechanism.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.