Control device and control method for non-contact processing machine

Abstract

Suppresses excessive retraction and overshoot. A control device for a non-contact processing machine that, when moving a processing head from a processing end position to a processing start position where the next non-contact processing will be performed, retracts the processing head from the processing position to a retract position and returns the processing head from the retract position to the processing start position, and the control device is equipped with an evacuation height determination unit that determines a first evacuation height at which the evacuation and return of the processing head can be completed within a movement time specified from the horizontal movement distance and movement speed of the processing head from the processing position to the processing start position, a second evacuation height acquisition unit that acquires a predetermined second evacuation height, and an evacuation height selection unit that selects the higher of the first and second evacuation heights as the height of the evacuation position.

Description

[Technical field]

[0001] The present disclosure relates to a control device and a control method for a non-contact processing machine, and more particularly to a control device and a control method for a non-contact processing machine that controls the operation of a processing head based on processing program commands. [Background technology]

[0002] In laser processing, when moving from the processing end position to the processing start position where the next non-contact processing will be performed, there is a technique in which the processing head is vertically withdrawn (raised) while moving horizontally to the next processing position, and then the processing head is returned (lowered) as it approaches the next processing start position.

[0003] Patent Document 1 describes a laser processing device that performs stable laser processing of a workpiece by avoiding collision between the processing head and the workpiece. Specifically, Patent Document 1 describes a laser processing apparatus that includes an NC control unit that controls the relative position of the workpiece and the processing head, and a distance detection unit that detects the shortest distance between the processing surface of the workpiece and the processing head as distance information when the NC control unit moves the processing head from a retracted position to approach the next processing point, and that the NC control unit performs tracking control of the processing head based on the distance information detected by the distance detection unit when moving the processing head from the retracted position to the next processing point, and that when approaching, the NC control unit uses diagonal descent control to move the processing head diagonally downward from the retracted position to the next processing point.

[0004] Patent document 2 describes a laser processing machine that can prevent the processing head from colliding with the workpiece when the workpiece to be processed has a different height direction or when processing a workpiece attached to a rotating shaft. Specifically, Patent Document 2 describes that in a numerical control device for a laser processing machine, the position command calculation unit of the processing head avoids collision with the workpiece by switching to gap control if a gap sensor detects a workpiece when operating in the Z-axis direction to bring the processing head closer to the workpiece. At this time, whether the operation of bringing the processing head closer to the workpiece is performed by gap control (detection value of the gap sensor) or to a position determined by parameters can be switched by adding a mode switching means to the position command calculation unit of the processing head.

[0005] Patent Document 3 describes a laser processing device that can perform high-speed and reliable tracking movement of a laser processing head over a workpiece having an opening. Specifically, Patent Document 3 describes a control unit that controls a head drive unit to move a laser processing head that irradiates a laser beam onto a workpiece along the workpiece. When a moving projection path, which is a projection of a predetermined moving path of the laser processing head onto the workpiece, crosses multiple openings, the control unit obtains a maximum hole-cutting distance from among the hole-cutting distances that are the distances that the moving projection path covers for each opening, determines whether the laser processing head can pass through the opening that provides the maximum hole-cutting distance by following the movement, and when it is determined that the laser processing head can pass through by following the movement, controls the laser processing head to pass through all of the multiple openings by following the movement. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-110389 A [Patent Document 2] JP 2016-47540 A [Patent Document 3] JP 2017-131897 A Summary of the Invention [Problem to be solved by the invention]

[0007] The vertical retraction speed of the machining head and the horizontal movement speed of the machining head are generally set as fast as possible depending on the machine characteristics. The vertical retract height is generally set uniformly so as not to collide with the workpiece that has jumped up, regardless of the horizontal movement distance to the processing start position. If the horizontal movement distance is short compared to the retract height, excessive retraction occurs when the processing head retracts and returns.

[0008] If it is determined that the horizontal movement distance is too short for the preset retraction height and retraction will not be completed, the retraction operation can be interrupted. If the retraction operation is interrupted midway, overshoot occurs between the interruption of the retraction (ascension) and the start of the return (descent) operation. Excessive retraction or overshooting results in high energy consumption.

[0009] Therefore, there is a need for a control device and a control method for a non-contact processing machine that can suppress excessive retraction operations and overshooting and reduce energy consumption. [Means for solving the problem]

[0010] A first representative aspect of the present disclosure is a control device for a non-contact processing machine, which controls the operation of a processing head based on a processing program command to perform non-contact processing on a workpiece, and when moving the processing head from a processing end position to a processing start position for performing a next non-contact processing, retracts the processing head from the processing end position to a retract position, and returns the processing head from the retract position to the processing start position, a retraction height determination unit that determines a first retraction height at which the retraction and return of the machining head can be completed within a movement time specified from a horizontal movement distance and a movement speed of the machining head from the machining end position to the machining start position; a second evacuation height acquisition unit that acquires a preset second evacuation height; and a retraction height selection unit that selects the higher of the first retraction height and the second retraction height as the height of the retraction position.

[0011] A second representative aspect of the present disclosure is a method for controlling a non-contact processing machine by a computer. A control method for performing non-contact processing on a workpiece by controlling an operation of a processing head based on a processing program command, and when moving the processing head from a processing end position to a processing start position where a next non-contact processing is performed, controlling the processing head to retreat from the processing end position to a retreat position and to return the processing head from the retreat position to the processing start position, The computer, determining a first retraction height at which the retraction and return of the machining head can be completed within a movement time specified from a horizontal movement distance and a movement speed of the machining head from the machining end position to the machining start position; Obtaining a second preset retract height; The control method includes a step of selecting the higher of the first retraction height and the second retraction height, and setting the selected retraction height as the height of the retract position. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing a configuration example of a control device for a non-contact processing machine according to a first embodiment of the present disclosure. [Diagram 2] 1A to 1C are diagrams illustrating a method of moving a processing head of a non-contact processing machine. [Diagram 3] 13A to 13C are diagrams illustrating the retraction operation and the return operation when the first retraction height H1 is higher than the second retraction height H2. [Figure 4] 13A to 13C are diagrams illustrating the retraction operation and the return operation when the second retraction height H2 is higher than the first retraction height H1. [Diagram 5] 4 is a flowchart showing an example of a control method for a non-contact processing machine. [Figure 6]FIG. 13 is a diagram showing a case where the horizontal movement distance is sufficiently long compared to the retraction height, and no excessive retraction occurs during the retraction and return operations. [Figure 7] 13 is a diagram showing a case where the horizontal movement distance is short compared to the retract height, and an excessive retraction operation occurs during retraction and return operations. FIG. [Figure 8] 13A and 13B are diagrams illustrating a case where an escape operation is interrupted and an overshoot occurs. [Figure 9] FIG. 13 is a diagram showing a case where a workpiece is supported by a pin holder on the processing table. [Figure 10] 1 is a diagram showing how, when cutting a workpiece with a laser processing machine, a part of the cut workpiece jumps up depending on the position of the tip of a needle holder. FIG. [Figure 11] FIG. 13 is a diagram showing the relationship between the horizontal movement distance and the evacuation height when an upper limit value for the evacuation height is set. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. (First embodiment) FIG. 1 is a block diagram showing an example of the configuration of a control device for a non-contact processing machine according to a first embodiment of the present disclosure.

[0014] 1, the control device 10 includes a program storage unit 101, a program analysis unit 102, a retraction height determination unit 103, a second retraction height acquisition unit 104, a retraction height selection unit 105, and an axis drive control unit 106. At least one of the program storage unit 101, the program analysis unit 102, and the axis drive control unit 106 may be provided outside the control device 10.

[0015] The non-contact processing machine 20, in which the axis drive control unit 106 performs axis drive control for moving the processing head 200, is not particularly limited, but may be, for example, a laser processing machine, a plasma discharge processing machine, or a water jet processing machine. The configuration and operation of the laser processing machine, the plasma discharge processing machine, or the water jet processing machine are already known, so a description thereof will be omitted.

[0016] As shown in FIG. 2, the control device 10 controls the non-contact processing machine 20 to move the processing head 200 from the processing end position of the workpiece 30, which is a non-machined object, to the processing start position (hereinafter referred to as the processing start position) where the next non-contact processing is performed, in processing by the non-contact processing machine 20. Specifically, in FIG. 2, the control device 10 first vertically retracts (raises) the processing head 200 from the processing end position, and then moves the processing head 200 horizontally while retracting (raising) the processing head 200 vertically to the retract height. Thereafter, the control device 10 moves the processing head 200 horizontally toward the processing start position at the retract height. Furthermore, the control device 10 moves the processing head 200 horizontally while lowering it vertically toward the processing start position, and then stops the horizontal movement at the processing start position and returns (lowers) the processing head 200. In FIG. 2, the movement path of the processing head 200 is shown by a broken line. As described later, the movement path of the processing head 200 may be a triangular mountain shape as shown in Fig. 3, or a square mountain shape as shown in Fig. 4. By retracting the processing head 200 in the vertical direction, even if there is an obstacle on the processing table surface, it is possible to avoid collision between the processing head 200 and the obstacle.

[0017] Each part of the control device 10 will be described below with reference to FIG. The program storage unit 101 stores a processing program for controlling the non-contact processing machine 20 . The program analysis unit 102 reads out and analyzes the machining program stored in the program storage unit 101, generates a movement command block for the motors that drive each axis of the non-contact machining device 20, and outputs it to the retraction height determination unit 103. The movement command block includes the horizontal movement distance L of the machining head 200 and the horizontal movement speed F. The movement speed F is an average speed because the horizontal speed of the machining head 200 is accelerated and decelerated.

[0018] The retraction height determination unit 103 calculates a movement time T based on the horizontal movement distance L and movement speed F commanded by the movement command block, and determines a first retraction height H1 at which the machining head 200 can be retracted and returned within the movement time T based on the retraction speed Fz of the machining head. The retraction speed Fz is also an average speed because the vertical speed of the machining head 200 is accelerated and decelerated. For example, the retraction height H1 can be calculated as H1=Fz×T / 2, that is, H1=Fz×(L / F) / 2.

[0019] The second retraction height acquisition unit 104 acquires a preset second retraction height H2. The second retraction height H2 is, for example, a height equivalent to the thickness of the workpiece. The second retraction height H2 may be set based on the work thickness and the processing program. For example, when the non-contact processing machine 20 cuts the work 30, which is a non-machined object, a part of the cut work 30 may jump up depending on the cut shape and thickness of the work 30. For example, in the case of a laser processing machine, a part of the cut work 30 may be pushed up by an assist gas ejected coaxially with the laser light, and in the case of a water jet processing machine, a part of the cut work 30 may be pushed up by a water jet. The jump up height can be automatically estimated based on the work thickness and the processing program, and the second retraction height H2 can be set based on the estimated value.

[0020] The second retraction height H2 may be set based on the shape and height of a pin stand when the workpiece is supported by a pin stand on the processing table. As shown in Fig. 9, when the workpiece 30 is placed on a pin stand, the second retraction height H2 depends on the height of the pin stand. Also, when cutting the workpiece 30 with a non-contact processing machine, a part of the cut workpiece 30 may jump up depending on the shape of the pin stand. Fig. 10 shows how a part of the cut workpiece 30 jumps up depending on the position of the needle tip of the pin stand when cutting the workpiece 30 with a laser processing machine. Therefore, the second retraction height H2 is set based on the shape and height of the pin stand.

[0021] The retraction height selection unit 105 compares the first retraction height H1 and the second retraction height H2, and selects the higher retraction height. Then, the retraction height selection unit 105 drives and controls the axis drive control unit 106 so that the operation includes retraction to the selected height and return from the retraction position to the processing start position.

[0022] The axis drive control unit 106 controls the motors that drive the axes of the non-contact processing machine so that the operation includes retraction to the selected height and return from the retraction position to the processing start position.

[0023] FIG. 3 is a diagram for explaining the retraction operation and the return operation when the first retraction height H1 is higher than the second retraction height H2. The thick arrow in FIG. 3 indicates the movement path of the machining head 200. When the first retraction height H1 is higher than the second retraction height H2, the retraction height selection unit 105 selects the first retraction height H1. Then, the retraction height selection unit 105 drives and controls the axis drive control unit 106 so that the operation includes retraction to the selected first retraction height H1 and return from the retraction position to the machining start position. FIG. 3 shows a case in which the vertical movement and the horizontal movement of the machining head 200 are performed simultaneously.

[0024] FIG. 4 is a diagram for explaining the retraction operation and the return operation when the second retraction height H2 is higher than the first retraction height H1. The thick arrow in FIG. 4 indicates the movement path of the machining head 200. When the second retraction height H2 is higher than the first retraction height H1, the retraction height selection unit 105 selects the second retraction height H2. In this case, as shown in FIG. 4, the retraction height selection unit 105 desirably controls the drive of the axis drive control unit 106 so as to drive the axis of the machining head so as to retract the machining head 200 straight up to avoid collision with the workpiece 30 on the machining table, and then move it horizontally, and lower the machining head 200 after the horizontal movement is completed. The retraction height selection unit 105 drives and controls the drive of the axis drive control unit 106 so as to perform an operation including retraction to the selected second retraction height H2 and return from the retraction position to the machining start position. In FIG. 4, the vertical and horizontal movements of the processing head 200 are performed independently, but in order to suppress excessive retraction operations, the vertical retraction height is determined within a movement time determined from the horizontal movement distance and movement speed of the processing head.

[0025] 5 is a flowchart showing an example of a control method for a non-contact processing machine. In the following description, an example in which the control method of the present disclosure is executed by the control device 10 will be described, but the control method for a non-contact processing machine of the present disclosure can also be executed by a configuration other than the control device 10.

[0026] In step S1, the retraction height determination unit 103 calculates a movement time T based on the horizontal movement distance L and movement speed F commanded by the movement command block output from the program analysis unit 102, and determines a first retraction height H1 at which the machining head 200 can be retracted and returned within the movement time T based on the retraction speed Fz of the machining head.

[0027] In step S2, the second retraction height acquisition unit 104 acquires a preset second retraction height H2.

[0028] In step S3, the retraction height selection unit 105 compares the first retraction height H1 with the second retraction height H2 and selects the higher retraction height. Then, the retraction height selection unit 105 drives and controls the axis drive control unit 106 so that the operation includes retraction to the selected height and return from the retraction position to the processing start position.

[0029] In step S4, the retraction height selection unit 105 controls the drive shaft of the machining head 200 via the shaft drive control unit 106 so that the operation includes retraction to the selected height and return from the retraction position to the machining start position.

[0030] In step S6, it is determined whether or not to continue the process. If the process is not to be continued (if "NO"), the process ends, and if the process is to be continued (if "YES"), the process returns to step S1.

[0031] According to the control device and the control method for the non-contact processing machine of the present embodiment described above, it is possible to suppress excessive retraction and overshooting, and to retract the processing head to a set position. Furthermore, by suppressing excessive retraction or overshooting, it is possible to reduce energy consumption.

[0032] The effect of suppressing the excessive retraction operation and overshooting will be specifically described below. As shown in Fig. 6, the horizontal movement distance is sufficiently long compared to the retraction height, and no excessive retraction occurs during the retraction and return operations. However, as shown in Fig. 7, if the horizontal movement distance is short compared to the retraction height, excessive retraction occurs during the retraction and return operations. The thick arrows in Fig. 6 and Fig. 7 indicate the movement path of the processing head 200. The dashed arrow in Fig. 7 indicates the movement path of the processing head 200 when there is no excessive retraction. In this embodiment, the movement time T is calculated based on the horizontal movement distance and the movement speed, and the first retraction height at which the processing head can be retracted and returned within the movement time is determined based on the retraction speed of the processing head. Since the retraction height can be set taking the horizontal movement distance into consideration, excessive retraction operation can be suppressed.

[0033] As shown in Fig. 8, if it is determined that the horizontal movement distance is short relative to the preset retraction height and retraction is not completed, the retraction operation may be interrupted. However, in this case, overshoot occurs between the interruption of the retraction (ascension) and the start of the return (descent) operation. The thick arrow in Fig. 8 indicates the movement path of the processing head 200. In this embodiment, the movement time T is calculated based on the horizontal movement distance and the movement speed, and the first retraction height at which the processing head can be retracted and returned within the movement time is determined based on the retraction speed of the processing head. Since the retraction height can be set taking the horizontal movement distance into consideration, it is possible to avoid interrupting the retraction operation and suppress overshooting.

[0034] Second embodiment In the first embodiment, the retraction height determination unit 103 determines the first retraction height H1 using the horizontal movement distance L, so that the retraction height is set higher as the movement distance L increases. However, if the retraction height is too high, the movement time required for the machining head to retract to the retraction height and return from the retraction height position to the machining start position increases. Therefore, in this embodiment, the retraction height determination unit 103 determines the first retraction height H1 so that the retraction operation and the return operation can be completed within the specified movement time.

[0035] The configuration of the control device of this embodiment is the same as the configuration of the control device 10 of the first embodiment. The retraction height determination unit 103 sets the first retraction height H1 to be equal to or less than the upper limit value H1up of the avoidance height so that the retraction operation and the return operation can be completed within the specified movement time. The upper limit value H1up is an upper limit threshold value. 11 is a diagram showing the relationship between the horizontal movement distance and the evacuation height when an upper limit value for the evacuation height is set. When the horizontal movement distance is L1, an evacuation height H11 is generated, and when the horizontal movement distance is L2 less than L1, an evacuation height H12 higher than the evacuation height H11 is generated. When the evacuation height H12 exceeds the upper limit value H1up of the avoidance height, the evacuation height H12 is generated so as to be equal to or less than the upper limit value H1up of the avoidance height.

[0036] According to the control device and control method for a non-contact processing machine of this embodiment described above, in addition to the effects of the first embodiment, an upper limit for the retraction height is set, so that the retraction and return operations can be performed within a specified movement time.

[0037] In order to realize the functional blocks included in the control device in each embodiment described above, the control device can be realized by hardware, software, or a combination of these. The access information output method can also be realized by hardware, software, or a combination of these. Here, being realized by software means being realized by a computer reading and executing a program.

[0038] In order to realize the components included in the control device by software or a combination of these, the control device includes a processor such as a CPU (Central Processing Unit). The processor functions as an execution unit. The control device also includes a secondary storage device such as a HDD (Hard Disk Drive) that stores various control programs such as application software or an OS (Operating System), and a primary storage device such as a RAM (Random Access Memory) for storing data temporarily required for the processor to execute a program.

[0039] The control device then performs arithmetic processing based on the application software or OS, while the arithmetic processing device reads the application software or OS from the auxiliary storage device and develops the read application software or OS in the main storage device. Based on the results of this calculation, the control device controls various hardware devices provided in the control device. In this way, the functional blocks of this embodiment are realized. The control method can also be realized by a configuration similar to that of the control device.

[0040] The components included in the control device can be realized by hardware including electronic circuits, etc. When the control device is configured by hardware, some or all of the functions of the components included in the control device can be configured by integrated circuits (ICs), such as ASICs (Application Specific Integrated Circuits), gate arrays, FPGAs (Field Programmable Gate Arrays), CPLDs (Complex Programmable Logic Devices), etc.

[0041] The program can be stored and provided to the computer using various types of non-transitory computer readable media. The non-transitory computer readable media includes various types of tangible storage media. Examples of the non-transitory computer readable media include magnetic recording media (e.g., hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROM (Read Only Memory), CD-R, CD-R / W, and semiconductor memory (e.g., mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, and RAM (random access memory)). The program may also be provided to the computer by various types of transitory computer readable media.

[0042] According to the control device and the control method of the present disclosure including the above-described embodiments, the retraction height can be set according to the moving distance, so that excessive retraction operation can be suppressed and the machining head can be retracted to the maximum height. In addition, by suppressing excessive retraction operation or overshooting, energy consumption can be reduced.

[0043] Although each of the above-described embodiments is a preferred embodiment of the present invention, the scope of the present invention is not limited to only the above-described embodiments, and the present invention can be implemented in various modified forms without departing from the gist of the present invention.

[0044] The following supplementary notes are further disclosed regarding the above embodiment. (Appendix 1) A control device (10) for a non-contact processing machine (20) which controls an operation of a processing head based on a processing program command to perform non-contact processing on a workpiece (30), and when moving the processing head from a processing end position to a processing start position where a next non-contact processing is performed, retracts the processing head from the processing end position to a retract position and returns the processing head from the retract position to the processing start position, a retraction height determination unit (103) that determines a first retraction height at which the retraction and return of the machining head can be completed within a movement time specified from the horizontal movement distance and movement speed of the machining head from the machining end position to the machining start position; a second evacuation height acquisition unit (104) that acquires a preset second evacuation height; and a retraction height selection unit (105) that selects the higher of the first retraction height and the second retraction height as the height of the retraction position.

[0045] (Appendix 2) The control device described in Appendix 1 includes an axis drive control unit (106) that controls a drive axis of the machining head, and the retraction height selection unit (105) controls the axis drive control unit so that the machining head performs an operation including retraction to the height of the retraction position and return from the height of the retraction position to the machining start position.

[0046] (Appendix 3) 3. The control device according to claim 1, wherein the evacuation height determination unit (103) determines the first evacuation height within a range of an upper threshold.

[0047] (Appendix 4) 3. The control device according to claim 1 or 2, wherein the non-contact processing machine (20) is a laser processing machine, a plasma discharge processing machine, or a water jet processing machine.

[0048] (Appendix 5) The computer controls the non-contact processing machine (20) to A control method for performing non-contact processing on a workpiece (30) by controlling an operation of a processing head based on a processing program command, and when moving the processing head from a processing end position to a processing start position where a next non-contact processing is performed, controlling the processing head to retreat from the processing end position to a retreat position and to return the processing head from the retreat position to the processing start position, The computer, determining a first retraction height at which the retraction and return of the machining head can be completed within a movement time specified from a horizontal movement distance and a movement speed of the machining head from the machining end position to the machining start position; Obtaining a second preset retract height; a step of selecting the higher of the first retraction height and the second retraction height, and setting the selected retraction height as the height of the retract position; [Explanation of symbols]

[0049] 10 Control device 20 Non-contact processing machine 30 Work 101 Program memory section 102 Program Analysis Unit 103 Evacuation height determination unit 104 Second evacuation height acquisition unit 105 Evacuation height selection section 106 Axis Drive Control Unit 200 Processing head

Claims

1. A control device for a non-contact processing machine, which controls an operation of a processing head based on a processing program command to perform non-contact processing on a workpiece, and when moving the processing head from a processing end position to a processing start position where a next non-contact processing is performed, retracts the processing head from the processing end position to a retract position and returns the processing head from the retract position to the processing start position, a retraction height determination unit that determines a first retraction height at which the retraction and return of the machining head can be completed within a movement time specified from a horizontal movement distance and a movement speed of the machining head from the machining end position to the machining start position; a second evacuation height acquisition unit that acquires a preset second evacuation height; a retraction height selection unit that selects the higher of the first retraction height and the second retraction height as the height of the retraction position.

2. The control device according to claim 1, further comprising an axis drive control unit that controls a drive axis of the machining head, and the retraction height selection unit controls the axis drive control unit so that the operation includes retracting the machining head to the height of the retraction position and returning it from the height of the retraction position to the machining start position.

3. The control device according to claim 1 , wherein the retraction height determination unit determines the first retraction height within a range of an upper threshold value.

4. 3. The control device according to claim 1, wherein the non-contact processing machine is a laser processing machine, a plasma discharge processing machine, or a water jet processing machine.

5. The computer controls the non-contact processing machine. A control method for performing non-contact processing on a workpiece by controlling an operation of a processing head based on a processing program command, and when moving the processing head from a processing end position to a processing start position where a next non-contact processing is performed, controlling the processing head to retreat from the processing end position to a retreat position and to return the processing head from the retreat position to the processing start position, The computer, determining a first retraction height at which the retraction and return of the machining head can be completed within a movement time specified from a horizontal movement distance and a movement speed of the machining head from the machining end position to the machining start position; Obtaining a second preset retract height; a step of selecting the higher of the first retraction height and the second retraction height, and setting the selected retraction height as the height of the retract position;

Images