JP6235623B2 - Laser processing system with adjustable output command switching timing - Google Patents

Description

  The present invention relates to a laser processing system having a function of adjusting a timing for switching a laser output command with respect to axial movement.

  In general, in laser processing, the movement of the drive shaft of a processing nozzle that irradiates laser light and the laser output must be synchronized. For this reason, conventionally, the laser oscillator is controlled by a numerical controller (CNC), the laser output command is calculated at the same calculation cycle as the axis movement command, and the axis movement command is calculated by connecting the laser oscillator to the servo amplifier. By outputting the laser output command along the same route, the synchronization between the axis movement command and the laser output command is ensured.

  As a related art related to this, for example, in Patent Document 1, a start / end code registration unit capable of registering a plurality of types of NC codes for cutting start beam-on, and a beam-on attribute added to a required portion of the cutting shape drawn on the screen. There is described an automatic programming device having a beam on / off attribute changing unit that individually changes the type of the beam within the range of types that can be registered in the NC code for starting beam on cutting by inputting from the man-machine interface unit.

  Further, in Patent Document 2, when a beam on / off command is output, a delay time until the machining head moving path approaches the target coordinate in the moving command is calculated from the data related to the moving command and the time constant of the acceleration. The laser output control that controls the output of the laser beam of the laser oscillator and receives the beam on / off command, and counts the time by the delay time calculated by the delay time calculating unit and then executes the beam on / off command. A laser processing apparatus having a means is described.

  Further, Patent Document 3 discloses a program analysis unit that analyzes a machining program and outputs a movement command for each axis and a laser beam on / off command, and an interpolation that performs an interpolation process based on the movement command and outputs a movement distance to a servo amplifier. Means for setting a moving distance for delay operation, and a beam on / off command to be output to the laser oscillator based on the actual moving distance after the output of the on / off command and the moving distance for delay operation. A laser processing apparatus having a beam on / off delay means for delaying is described.

JP-A-10-128564 JP 09-108863 A International Publication No. 2000/053363

  In the laser processing apparatus as described above, the shaft movement command and the laser output command are synchronized, but the response of the excitation power source of the laser oscillator is delayed or the workpiece is actually cut after being irradiated with the laser beam. In this case, there is a problem that the laser processing accuracy is lowered because the delay time until the data transfer time and the delay in the data transfer time from the CNC to the oscillator are not considered.

  In the technique described in Patent Document 1, the piercing conditions can be set by an automatic programming device, but the response delay of the laser excitation power source is not considered. In addition, the techniques described in Patent Documents 2 and 3 do not take into account the response delay of the laser excitation power supply.

  Accordingly, an object of the present invention is to provide a laser processing system that is intended to appropriately adjust the timing at which a laser output command is switched with respect to axial movement and to improve the synchronization accuracy between axial movement and cutting position.

In order to achieve the above object, a first invention of the present application is a laser processing machine operable along a control axis, an axis driving unit that drives the control axis, and a laser that supplies laser light to the laser processing machine. In a laser processing system comprising an oscillator and a control device for controlling the shaft drive unit and the laser oscillator, the control device is configured to transmit movement data to be commanded to the shaft drive unit and the laser oscillator from a predetermined laser processing program. A data creation unit for creating laser output command data to be commanded to the laser, and the movement data and the laser output command data created by the data creation unit are sent to the shaft drive unit and the laser oscillator at predetermined command cycles, respectively. A data transmission unit, wherein the data creation unit analyzes the laser machining program and outputs a laser output command of the block being executed. Create a laser output command for the block next to the block being executed, calculate the remaining time of the block being executed from the moving speed of the control axis and the remaining moving distance of the block being executed, and the remaining time is a predetermined switching time. when it is less than, the laser irradiation the laser output command included in the laser output command data sent to the laser oscillator, a laser output command in the next block from the laser stop command is a laser output command in the block in execution The execution time of the block being executed is calculated from the first switching procedure for switching to the command , the moving speed of the control axis and the moving distance of the block being executed, and when the execution time exceeds a predetermined switching time, block running laser output command included in the laser output command data sent to the laser oscillator, the laser emission command is a laser output command of the previous block A second switching換手order to switch the laser stop command is a laser output command, at least one is carried out, to provide a laser processing system.

  According to a second aspect, in the first aspect, the switching time is a rise time of the laser excitation power source, a time from when the workpiece is irradiated with the laser light until it is actually cut, from the control device to the laser oscillator. A laser processing system is provided that is determined based on at least one of a delay time related to data transfer and a delay time of a servo that drives the control axis.

  According to a third invention, there is provided the laser processing system according to the first or second invention, wherein the switching time is separately set when laser beam irradiation is started and stopped.

  A fourth invention provides the laser processing system according to any one of the first to third inventions, wherein the switching time is specified by a parameter.

  A fifth invention provides the laser processing system according to any one of the first to third inventions, wherein the switching time is set by a command included in the laser processing program.

  According to the present invention, even when the response time of the laser excitation power source is slow, the synchronization accuracy between the movement of the shaft and the cutting position can be improved, and the laser processing accuracy can be improved.

It is a functional block diagram of the principal part of the laser processing system which concerns on suitable embodiment of this invention. It is a figure which shows schematic structure of the laser processing system of FIG. It is a graph showing the relationship between a laser output command and a speed command. It is a flowchart which shows the 1st process example in the laser processing system of this invention. It is a flowchart which shows the 2nd process example in the laser processing system of this invention. It is a graph showing the other relationship of a laser output command and a speed command.

  FIG. 1 is a functional block diagram of the main part of a laser processing system according to a preferred embodiment of the present invention. The laser processing system 10 includes a laser processing machine 12 operable along a control axis, an axis drive unit 14 that drives the control axis of the laser processing machine 12, and a laser oscillator 16 that supplies laser light to the laser processing machine 12. And a control device (CNC) 18 for controlling the shaft drive unit 14 and the laser oscillator 16.

  The control device 18 reads and analyzes a predetermined machining program 20, and generates a movement data to be commanded to the axis drive unit 14 and a laser output command data to be commanded to the laser oscillator 16, and a data creation And a data transmission unit 24 for sending the movement data and the laser output command data created by the unit 22 to the shaft driving unit 14 and the laser oscillator 16 at predetermined command cycles, respectively. Note that the control device 18 may include a data conversion unit 26 that converts the format of data created by the data creation unit 22 into a format suitable for transmission by the data transmission unit 24 as necessary.

  FIG. 2 is a diagram illustrating a configuration example of the laser processing system 10. The laser beam machine 12 is movable along the XY plane (substantially horizontal plane) by three linear motion axes (X axis 28, Y axis 30 and Z axis 32) orthogonal to each other, and X axis 28 and Y axis 30. The configured XY table 34 and a processing nozzle 36 that can be displaced in the Z direction (substantially up and down direction) with respect to the XY table 34 by the Z axis 32 are irradiated with laser light from the processing nozzle 36. Thus, a predetermined laser processing can be performed on the workpiece (workpiece) 38 placed on the XY table 34.

  In the example of FIG. 2, the axis drive unit 14 includes an X-axis amplifier 40, a Y-axis amplifier 42, and a Z-axis amplifier 44 for driving and controlling the X-axis 28, the Y-axis 30, and the Z-axis 32 (for example, a servo motor). including. On the other hand, the control device 18 includes a CPU 46, a ROM 48, a RAM 50, a nonvolatile memory 52, a data input / output unit (I / O) 54, and a manual data input unit (MDI) 56 with a display, via the I / O 54. The movement data and the laser output command data can be transmitted to each amplifier and laser oscillator 16.

  In the example of FIG. 2, the functions of the data creation unit 22 and the data conversion unit 26 described above can be performed by the CPU 46, and the function of the data transmission unit 24 can be performed by the I / O 54. Further, the laser processing program 20 may be stored in the RAM 50 or the nonvolatile memory 52, or may be stored in another device connected to the control device 18.

  Next, processing in the laser processing system 10 will be described with reference to FIGS. FIG. 3 is a graph showing the speed command (axis movement) to the control axis and the laser output command (laser output) to the laser oscillator so that they can be compared on the same time axis. The graph 60 represents the relationship between time and laser command. In general, in the control device 18 (CNC), while executing a block having a machining program (usually corresponding to one line of the machining program and serving as a command unit to the axis driving unit 14 and the laser oscillator 16), the next block The subsequent block information is read, and the movement amount of the axis is calculated in advance. In the example of FIG. 3, in block 62, laser processing is performed at a laser output P for a certain part (region) of the workpiece 38 while moving the control axis at speed V, and in block 64, laser irradiation is stopped and speed V is reached. In block 66, the other part (region) of the workpiece 38 is subjected to laser processing with the laser output P while moving the control axis at the speed V.

  Here, in the present invention, while executing a block having a machining program (current block), the next block command is prefetched to create and store the next block laser output command, and the axis feed speed and block The remaining time of the block is calculated from the remaining moving distance, and when the remaining time becomes less than the predetermined switching time, the laser output command created by the data creation unit 22 is switched from the current block to that of the next block. Prior to the block switching, the laser output command can be switched (block 62 → 64 in FIG. 3), and this is hereinafter also referred to as a first switching procedure. This is a case where the switching time in FIG. 3 is negative. The laser output condition is determined in consideration of the response delay time of the laser excitation power source, the time from when the workpiece is irradiated with the laser beam until the workpiece is actually cut. Used when ordering early.

  Alternatively, even after execution of the previous block is completed and execution of the current block is started, the laser output command of the previous block is continued, and the execution time of the current block (the block being executed) is a predetermined switching time. After the time elapses, the laser output command can be switched to the laser output command of the current block (the block being executed) (the laser output command is switched with a delay) (block 64 → 66 in FIG. 3). This is also referred to as a switching procedure. This is used when the switching time in FIG. 3 is positive and the laser output condition is delayed and commanded in consideration of the servo delay time.

  FIG. 4 is a flowchart showing details of the first switching procedure. First, in step S11, the remaining time of the block 62 being executed (= the remaining moving distance of the block 62 / the moving speed of the control axis) is calculated. In the next step S12, the calculated remaining time (block remaining time) is compared with a predetermined switching time t1. If the remaining block time is t1 or more, the laser output command in the current block 62 is continued. More specifically, the peak power, frequency, and duty ratio for irradiating the laser beam with the output P are It is output to the laser oscillator 16 (step S13).

  On the other hand, when the remaining block time is less than t1, the laser output command to the laser oscillator 16 is switched to the block 64 next to the current block 62 (step S14). In the example of FIG. 3, a command to stop laser irradiation is output, but a command (peak power, frequency, and duty ratio) for performing laser irradiation with an output different from the output P may be output to the laser oscillator 16. . The processes of steps S11 to S14 are repeated at a predetermined control cycle.

  Here, the switching time t1 is determined based on at least the response delay time of the laser excitation power source included in the laser oscillator 16, and the response delay time includes the rise time and the fall time of the laser excitation power source. That is, in the present invention, in actual laser processing, the time from when a command to start laser irradiation to the laser oscillator is sent until the laser light is actually irradiated (rise time), or laser irradiation to the laser oscillator In consideration of the fact that there is a time (fall time) from when the command to stop is sent until laser light is not actually irradiated, prior to block switching by the switching time corresponding to the rise time or fall time By switching the laser output command, the synchronization accuracy between the axis movement and the workpiece cutting position can be greatly improved, and laser processing with extremely high accuracy can be performed.

  In addition to the response delay time of the laser excitation power supply, the switching time is the time from when the workpiece 38 is irradiated with the beam until the workpiece 38 is actually cut, or when data is transferred from the control device 18 to the laser oscillator 16. It may be obtained based on the delay time. By further considering (usually adding) such time, the synchronization accuracy between the axis movement and the workpiece cutting position is further improved.

  FIG. 5 is a flowchart showing details of the second switching procedure. First, in step S21, the execution time (elapsed time) of the block 62 being executed (= the movement distance of the block 66 / the movement speed of the control axis) is calculated. In the next step S22, the calculated execution time (block execution time) is compared with a predetermined switching time t2. While the block execution time is t2 or less, the laser output command in the block 64 before the current block 66 is continued (step S23). In the example of FIG. 3, the command to stop laser irradiation is continued, but a command (peak power, frequency, and duty ratio) for performing laser irradiation with an output different from the output P may be output to the laser oscillator 16. .

  On the other hand, when the block execution time exceeds t2, the laser output command to the laser oscillator 16 is switched from the previous block 64 to the current block 66 (step S24). In the example of FIG. 3, the peak power, frequency, and duty ratio for irradiating the laser beam with the output P again are output from the control device 18 to the laser oscillator 16. The processes of steps S21 to S24 are repeated at a predetermined control cycle.

  The second switching procedure is the same as the first switching procedure in that the laser output command is switched quickly in consideration of the response delay of the laser excitation power supply, but the processing program block (block 66 in the example of FIG. 3) is the same as the first switching procedure. Since the start time is set earlier than the time corresponding to the response delay in consideration of the servo delay time (time constant), as a result, when the previous block 64 ends (when the block 66 starts). The laser output command is switched later. Thus, even when the axis speed command is set in consideration of the servo delay time, etc., in addition to the response delay time of the laser excitation power supply, etc., by setting the switching time in consideration of the servo delay time, etc. The present invention is applicable.

  Next, other processes in the laser processing system 10 will be described with reference to FIGS. FIG. 6 is a graph showing the speed command (axis movement) to the control axis and the laser output command (laser output) to the laser oscillator so that they can be compared on the same time axis. The graph 70 represents the relationship between time and laser command. In general, in the control device 18 (CNC), while executing a block having a machining program (usually corresponding to one line of the machining program and serving as a command unit to the axis driving unit 14 and the laser oscillator 16), the next block The subsequent block information is read, and the movement amount of the axis is calculated in advance. In the example of FIG. 6, in block 72, laser processing is performed with laser output P on a part (region) of the workpiece 38 while moving the control axis at speed V. In block 74, laser irradiation is stopped and speed V is reached. In block 76, the other part (region) of the workpiece 38 is subjected to laser processing with the laser output P while moving the control axis at the speed V.

  Here, in the present invention, while executing a block having a machining program (current block), the next block command is prefetched to create and store the next block laser output command, and the axis feed speed and block The remaining time of the block is calculated from the remaining moving distance, and when the remaining time becomes less than the predetermined switching time, the laser output command created by the data creation unit 22 is switched from the current block to that of the next block. Prior to the block switching, the laser output command can be switched (block 74 → 76 in FIG. 6), and this is hereinafter also referred to as a first switching procedure. This is a case where the switching time in FIG. 6 is negative. The laser output condition is determined in consideration of the response delay time of the laser excitation power supply, the time from when the workpiece is irradiated with the laser beam until the workpiece is actually cut. Used when ordering early.

  Alternatively, even after execution of the previous block is completed and execution of the current block is started, the laser output command of the previous block is continued, and the execution time of the current block (the block being executed) is a predetermined switching time. After that, the laser output command can be switched to the laser output command of the current block (the block being executed) (the laser output command is switched after a delay) (block 72 → 74 in FIG. 6). This is also referred to as a switching procedure. This is a case where the switching time of FIG. 6 is positive, and is used when the laser output condition is delayed and commanded in consideration of the servo delay time.

  FIG. 4 is a flowchart showing details of the first switching procedure in FIG. First, in step S11, the remaining time of the block 74 being executed (= the remaining moving distance of the block 74 / the moving speed of the control axis) is calculated. In the next step S12, the calculated remaining time (block remaining time) is compared with a predetermined switching time t1. If the remaining block time is t1 or more, the laser output command in the current block 74 is continued. More specifically, the peak power, frequency, and duty ratio for irradiating the laser beam with the output P are It is output to the laser oscillator 16 (step S13).

  On the other hand, when the remaining block time is less than t1, the laser output command to the laser oscillator 16 is switched to the block 76 next to the current block 74 (step S14). In the example of FIG. 6, a command to start laser irradiation is output, but a command (peak power, frequency, and duty ratio) for performing laser irradiation with an output different from the output P may be output to the laser oscillator 16. . The processes of steps S11 to S14 are repeated at a predetermined control cycle.

  Here, the switching time t1 is determined based on at least the response delay time of the laser excitation power source included in the laser oscillator 16, and the response delay time includes the rise time and the fall time of the laser excitation power source. That is, in the present invention, in actual laser processing, the time from when a command to start laser irradiation to the laser oscillator is sent until the laser light is actually irradiated (rise time), or laser irradiation to the laser oscillator In consideration of the fact that there is a time (fall time) from when the command to stop is sent until laser light is not actually irradiated, prior to block switching by the switching time corresponding to the rise time or fall time By switching the laser output command, the synchronization accuracy between the axis movement and the workpiece cutting position can be greatly improved, and laser processing with extremely high accuracy can be performed.

  In addition to the response delay time of the laser excitation power supply, the switching time is the time from when the workpiece 38 is irradiated with the beam until the workpiece 38 is actually cut, or when data is transferred from the control device 18 to the laser oscillator 16. It may be obtained based on the delay time. By further considering (usually adding) such time, the synchronization accuracy between the axis movement and the workpiece cutting position is further improved.

  FIG. 5 is a flowchart showing details of the second switching procedure in FIG. First, in step S21, an execution time (elapsed time) of the block 74 being executed (= movement distance of the block 74 / movement speed of the control axis) is calculated. In the next step S22, the calculated execution time (block execution time) is compared with a predetermined switching time t2. While the block execution time is t2 or less, the laser output command in the block 72 before the current block 74 is continued (step S23). Although the laser irradiation command is continued in the example of FIG. 6, a command (peak power, frequency, and duty ratio) for performing laser irradiation with an output different from the output P may be output to the laser oscillator 16.

  On the other hand, when the block execution time exceeds t2, the laser output command to the laser oscillator 16 is switched from the previous block 72 to the current block 74 (step S24). In the example of FIG. 6, a command for stopping the laser beam with the output P is output from the control device 18 to the laser oscillator 16. The processes of steps S21 to S24 are repeated at a predetermined control cycle.

  The second switching procedure is the same as the first switching procedure in that the laser output command is switched quickly in consideration of the response delay of the laser excitation power supply, but the processing program block (block 74 in the example of FIG. 6) Since the start time is set earlier than the time corresponding to the response delay in consideration of the servo delay time (time constant), as a result, when the previous block 72 ends (when the block 74 starts). The laser output command is switched later. Thus, even when the axis speed command is set in consideration of the servo delay time, etc., in addition to the response delay time of the laser excitation power supply, etc., by setting the switching time in consideration of the servo delay time, etc. The present invention is applicable.

  In the first switching procedure, the laser output command is switched at a time point that is a predetermined switching time (t1) before the end of execution of the block that is being executed. The laser output command is switched when a predetermined switching time (t2) elapses after the execution of the block is started. Accordingly, it can be considered that the switching time is a negative value in the first switching procedure and the switching time is a positive value in the second switching procedure. Therefore, according to the set sign of the switching time, that is, when the switching time is a negative value, the processing based on the first switching procedure is performed, and when the switching time is a positive value, the processing is based on the second switching procedure. Processing can also be performed. Alternatively, a positive value (absolute value) may be set as the switching time after providing means for selecting and determining either the first or second switching procedure.

  For example, the rise time and fall time of the laser excitation power supply may differ, the time from when the workpiece is irradiated with the beam until the workpiece is actually cut, and after the laser beam irradiation is actually stopped The time until the workpiece is not cut is usually different. Therefore, as in the first and second switching procedures shown in FIG. 3 or FIG. 6, the switching time can be independently set separately when the laser light irradiation is stopped and started. It is preferable. In this way, it is possible to correct the difference and improve the accuracy of the workpiece cutting length.

  Also, the time from when the beam is irradiated until the workpiece is actually cut or the time from when laser irradiation stops until the workpiece is no longer cut depends on the workpiece material and plate thickness. Therefore, it is preferable that the switching time can be designated as a parameter by an operator via an appropriate input device. As a result, the on / off timing of the laser beam can be freely adjusted, so that the degree of freedom regarding the adjustment of the workpiece cutting position is improved. Alternatively, the switching time may be set by a command included in the machining program. This makes it possible to improve the degree of freedom of the correction and make more detailed settings when it is necessary to correct the switching time due to changes in the servo delay time, such as when the machining speed is changed. .

  In the above-described embodiment, the laser beam machine 12 has three drive shafts (X, Y, and Z axes), and the workpiece 38 (the XY table 34 on which the workpiece 38 is placed) is movable in the XY direction. Yes, the machining nozzle 36 is movable in the Z direction. However, the scope of application of the present invention is not limited to this, and the laser machining machine is configured such that the machining nozzle can move relative to the workpiece by at least one control axis. Applicable.

DESCRIPTION OF SYMBOLS 10 Laser processing system 12 Laser processing machine 14 Axis drive part 16 Laser oscillator 18 Control apparatus 20 Laser processing program 22 Data preparation part 24 Data transmission part 26 Data conversion part 34 XY table 36 Processing nozzle 38 Workpiece | work

Claims (5)

A laser processing machine operable along a control axis, an axis driving unit for driving the control axis, a laser oscillator for supplying laser light to the laser processing machine, and a control for controlling the axis driving unit and the laser oscillator In a laser processing system comprising an apparatus,
The controller is
From a predetermined laser processing program, a data creation unit that creates movement data commanded to the shaft drive unit and laser output command data commanded to the laser oscillator;
A data transmission unit configured to transmit the movement data and the laser output command data created by the data creation unit to the shaft drive unit and the laser oscillator, respectively, in a predetermined command cycle;
The data creation unit
Analyzing the laser processing program, creating a laser output command for the block being executed and a laser output command for the block next to the block being executed,
The remaining time of the block being executed is calculated from the moving speed of the control axis and the remaining moving distance of the block being executed, and the laser output sent to the laser oscillator when the remaining time becomes less than a predetermined switching time A first switching procedure for switching a laser output command included in the command data from a laser stop command that is a laser output command of the block being executed to a laser irradiation command that is a laser output command of the next block;
The execution time of the block being executed is calculated from the moving speed of the control axis and the movement distance of the block being executed, and laser output command data sent to the laser oscillator when the execution time exceeds a predetermined switching time performing laser output command, a second switching換手order to switch the laser stop command from the laser emission command is a laser output command in the block in execution is the laser output command of the previous block, at least one of the contained, the laser Processing system.   The switching time includes the rise time of the laser excitation power source, the time from when the workpiece is irradiated with the laser light until it is actually cut off, the delay time related to data transfer from the control device to the laser oscillator, and the control axis. The laser processing system according to claim 1, wherein the laser processing system is determined based on at least one of a delay time of a driving servo.   3. The laser processing system according to claim 1, wherein the switching time is set separately when starting and stopping the irradiation of laser light. 4.   The laser processing system according to claim 1, wherein the switching time is specified by a parameter.   The laser processing system according to claim 1, wherein the switching time is set by a command included in the laser processing program.

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