Control device and laser processing apparatus including the same, and method for controlling the movement of the processing start point of the laser emission mechanism of a laser processing apparatus.

Abstract

The present invention relates to: a control device for a laser processing device comprising a laser emission mechanism that emits processing laser light in a direction along a unit vector, and a gap sensor provided in the laser emission mechanism; and a method for controlling displacement of a processing start point. The control device comprises: a main control unit that outputs a driving command to a constituent element of the laser processing device on the basis of a processing program; and a displacement command generation unit that generates a displacement command for displacing the laser emission mechanism using a detected value from a gap sensor. The displacement command generation unit has a function of generating: an approach command for displacing the laser emission mechanism from a control start position toward a laser irradiation point to a boundary gap point where the gap sensor starts detection; and a processing start point displacement command for displacing the laser emission mechanism from the boundary gap point to a processing start point within a detection range of the gap sensor. The processing start point displacement command includes a pose change that matches the unit vector at the boundary gap point with a processing vector at the processing start point.

Description

Technical Field

[0001] The present invention relates to a control device for a laser processing apparatus, and more particularly to a control device having a function of performing movement control for moving a laser emission mechanism such as a processing head to a processing start point.

Background Art

[0002] Laser processing apparatuses such as laser cutting machines and laser welding machines can perform predetermined processing by transmitting the processing laser light output from a laser oscillator and irradiating the workpiece, and relatively moving the processing laser light and the workpiece. In such a laser processing apparatus, when irradiating the workpiece with the processing laser light, while detecting the distance between the workpiece and the laser emission mechanism with a gap sensor provided in the laser emission mechanism such as a processing head, the detected distance is maintained at a predetermined value while performing laser processing according to a processing program. A control operation is known.

[0003] As a laser processing apparatus that executes such a control operation, for example, in Patent Document 1, while relatively moving a processing nozzle with respect to a workpiece according to a processing program, the processing nozzle is rotated about a predetermined rotation axis, and the laser light irradiated from the processing nozzle is used to perform laser processing on the workpiece. In the laser processing apparatus, a three-dimensional moving unit that relatively moves the processing nozzle in three-dimensional directions with respect to the workpiece, a rotating unit that rotates the processing nozzle about the rotation axis, a gap amount detection unit that detects the gap amount between the processing nozzle and the workpiece, a rotation position detection unit that detects the rotation position of the rotation axis by the rotating unit, and a command calculation unit that generates a command signal for maintaining the gap amount constant based on the detected gap amount and rotation position are provided. The three-dimensional moving unit is configured to relatively move the processing nozzle in three-dimensional directions with respect to the workpiece based on the command signal. According to such a laser processing apparatus, it is said that an error in the processing shape of the workpiece caused by the control of the gap amount can be reduced.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-192970 [Overview of the project] [Problems that the invention aims to solve]

[0005] As described above, when performing laser processing while performing tracing control to keep the gap between the processing nozzle and the workpiece constant based on the value detected by the gap amount detection unit, the following actions are performed at the start of processing: an approach action in which the laser emission mechanism is brought closer from a predetermined control start point towards the detection area where the gap amount detection unit can detect the gap amount; a rotation action in which the laser emission mechanism is rotated around a predetermined rotation axis (B axis); and a correction action in which the position of the unit vector after rotation (a vector defined with the nozzle tip as the starting point in the direction along the central axis of the laser emission mechanism) is corrected. Then, after the correction action, processing control of the laser processing based on the processing program is executed.

[0006] In the series of operations described above, the approach operation performs position control to bring the laser emission mechanism closer to the workpiece, for example, using the control start point described above as a reference. On the other hand, in the correction operation, the correction movement amount of the processing nozzle is determined using the intersection of the workpiece and the central axis of the processing nozzle as the reference position, and position control is performed to move the nozzle tip position from this intersection in the unit vector direction according to the correction movement amount.

[0007] In this case, in the control device that controls the operation of the laser processing machine, the reference position for position control of moving the laser emission mechanism is the control start point in the approach operation, while in the correction operation it is the intersection point of the central axis of the workpiece and the processing nozzle. Therefore, when the control device transitions from the approach operation to the correction operation, it is necessary to calculate the position of the laser emission mechanism related to position control in the correction operation after obtaining the reference position of the control command, which increases the computational load and causes a time lag when transitioning to the correction operation.

[0008] Given these circumstances, there is a need for a control device that can reduce the computational load of calculating the movement position of the laser emission mechanism included in the movement command when performing tracking control to keep the distance between the workpiece and the laser emission mechanism constant based on the value detected from the gap sensor in the movement control to move the laser emission mechanism (e.g., the processing head) to the starting point of processing. [Means for solving the problem]

[0009] A control device for controlling the operation of a laser processing apparatus, which includes a laser emission mechanism that emits processing laser light in a direction along a unit vector and a gap sensor provided on the laser emission mechanism, according to one aspect of the present invention, includes a main control unit that outputs drive commands to the components of the laser processing apparatus based on a processing program, and a movement command generation unit that generates movement commands for moving the laser emission mechanism using values ​​detected from the gap sensor, wherein the movement command generation unit has the function of generating an approach command that moves the laser emission mechanism from a control start position toward the laser irradiation point on the workpiece to a boundary gap point that the gap sensor begins to detect, and a processing start point movement command that moves the laser emission mechanism from the boundary gap point to a processing start point within the detection range of the gap sensor, wherein the processing start point movement command is configured to include a change in posture that makes the unit vector at the boundary gap point match the processing vector at the processing start point.

[0010] Furthermore, a laser processing apparatus according to another aspect of the present invention, which performs laser processing by irradiating a workpiece with processing laser light, includes a laser oscillator that emits processing laser light, a workpiece holding mechanism that holds the workpiece, a laser emission mechanism that emits processing laser light in a direction along a unit vector, a gap sensor provided on the laser emission mechanism, a transport mechanism that moves the laser emission mechanism relative to the workpiece holding mechanism, and a control device that controls the operation of each component of the laser processing apparatus, the control device further includes a main control unit that outputs drive commands to each component of the laser processing apparatus based on a processing program, and a movement command generation unit that generates a movement command for moving the laser emission mechanism using a value detected from the gap sensor, the movement command generation unit has the function of generating an approach command that moves the laser emission mechanism from a control start position toward the laser irradiation point on the workpiece to a boundary gap point that the gap sensor starts to detect, and a processing start point movement command that moves the laser emission mechanism from the boundary gap point to a processing start point within the detection range of the gap sensor, the processing start point movement command is configured to include a change in posture that makes the unit vector at the boundary gap point match the processing vector at the processing start point.

[0011] Furthermore, according to another aspect of the present invention, a method for controlling the starting point of a laser emission mechanism in a laser processing apparatus, which includes a laser emission mechanism that emits processing laser light in a direction along a unit vector and a gap sensor provided on the laser emission mechanism, moves the laser emission mechanism to the starting point of a tracing process, and includes an approach routine for moving the laser emission mechanism from a control start position toward the laser irradiation point on the workpiece to a boundary gap point where the gap sensor begins to detect, and a starting point movement routine for moving the laser emission mechanism from the boundary gap point to a starting point of a process that is within the detection range of the gap sensor, wherein the starting point movement routine includes a posture change step that makes the unit vector at the boundary gap point match the processing vector at the starting point of the process. [Effects of the Invention]

[0012] According to one aspect of the present invention, the movement command generation unit has the function of generating an approach command to move the laser emission mechanism from a control start position to a boundary gap point, and a processing start point movement command to move the laser emission mechanism from the boundary gap point to a processing start point. Furthermore, by configuring the processing start point movement command to be calculated based on the coordinate values ​​and vectors of the boundary gap point, the computational load of the movement position of the laser emission mechanism included in the movement command can be reduced in movement control to move the laser emission mechanism to a processing start point. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram showing the configuration of a laser processing apparatus including a control device according to the first embodiment. [Figure 2] This block diagram shows an example of the configuration of the laser processing apparatus shown in Figure 1. [Figure 3] This flowchart shows an overview of the processing start point movement control method executed by the control device in the laser processing apparatus according to the first embodiment. [Figure 4] Figure 3 is a flowchart illustrating the overview of the approach routine. [Figure 5] Figure 3 is a flowchart illustrating the overview of the machining start point movement routine. [Figure 6A] This is a partial front view showing an overview of the positional relationship between the laser emission mechanism and the workpiece at the start of the approach routine. [Figure 6B] This is a partial front view showing an overview of the positional relationship between the laser emission mechanism and the workpiece at the end of the approach routine. [Figure 6C] This is a partial front view showing an overview of the positional relationship between the laser emission mechanism and the workpiece at the start of the machining start point movement routine. [Figure 6D] This is a partial front view showing an overview of the positional relationship between the laser emission mechanism and the workpiece at the end of the machining start point movement routine. [Figure 7]It is a flowchart showing an outline of a machining start point movement routine in a machining start point movement control method executed by a control device according to a second embodiment which is another example of the present invention. [Figure 8] It is a partial front view showing an outline of a distance correction operation of a laser emission mechanism in a machining start point movement routine according to the second embodiment. [Figure 9] It is a flowchart showing an outline of a machining start point movement routine in a machining start point movement control method executed by a control device according to a third embodiment which is yet another example of the present invention.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of a laser processing apparatus including a control device according to a representative example of the present invention and a machining start point movement control method for a laser emission mechanism (for example, a machining head) in the laser processing apparatus will be described with reference to the drawings.

[0015] <First Embodiment> FIG. 1 is a schematic diagram showing the configuration of a laser processing apparatus including a control device according to a first embodiment which is a representative example of the present invention. Further, FIG. 2 is a block diagram showing an example of the configuration of the laser processing apparatus shown in FIG. 1.

[0016] As shown in FIG. 1, as an example, the laser processing apparatus 1 includes a laser oscillator 10 that oscillates a processing laser beam LB, a work holding mechanism 20 that holds a work W, a laser emission mechanism (for example, a machining head) 30 that emits the processing laser beam LB to the work W, a transport mechanism 40 that relatively moves the laser emission mechanism 30 with respect to the work holding mechanism 20, and a control device 100 that controls a predetermined laser processing operation on the work W.

[0017] The laser processing apparatus in this specification can be applied as an arbitrary processing apparatus that executes predetermined processing by irradiating a processing laser beam to a work W, such as laser welding, laser cutting, laser drilling (trepanning), laser marking, laser dicing, or laser annealing.

[0018] The laser oscillator 10 is configured to use a laser source with a wavelength that has high absorption efficiency depending on the material of the workpiece W being processed. Examples of such laser oscillators 10 include YAG lasers, YVO4 lasers, fiber lasers, disk lasers, and other lasers capable of fiber transmission. The processing laser light LB output from the laser oscillator 10 is transmitted to the laser emission mechanism 30 via a transmission path 34, such as an optical fiber.

[0019] The workpiece holding mechanism 20, as an example, includes a chuck mechanism (not shown) for attaching the workpiece W, and is configured as a machining table that can move freely in the three axes of X, Y, and Z shown in the figure while gripping and fixing the workpiece W. Furthermore, the workpiece holding mechanism 20 may also include a rotation mechanism (for example, a known configuration such as a B axis along the Y axis and a C axis along the Z axis) in addition to a mechanism for moving the workpiece W in the three axes.

[0020] As an example, the laser emission mechanism 30 is configured as a processing head in which processing laser light LB is introduced from one end (upper end) via a transmission line 34 such as an optical fiber and emitted from a nozzle 32 on the other end (lower end) toward the workpiece W. At this time, a focusing lens (not shown) placed inside the laser emission mechanism 30 focuses the processing laser light LB to a predetermined beam diameter at the laser irradiation point FP on the workpiece W.

[0021] In the present invention, the nozzle 32 functions not only as the exit port for the processing laser beam LB in the laser emission mechanism 30, but also as a gap sensor for detecting the distance D between the lower end of the laser emission mechanism 30 (nozzle 32) and the workpiece W. As an example of such a nozzle 32, a capacitive sensor can be applied.

[0022] In the example shown in Figure 1, the nozzle 32 is shown as part of the electrodes of the capacitance sensor. However, as described above, any sensor capable of detecting the gap between the workpiece W and the laser emission mechanism 30 can be used, and such a sensor may be directly attached to the laser emission mechanism 30. In this case, for example, a reference point for position measurement can be set on a part of the laser emission mechanism 30, and the distance between the laser emission mechanism 30 and the workpiece W can be determined by correcting the distance measured by the sensor using the relative position between the reference point and the sensor.

[0023] The transport mechanism 40, as an example, includes a linear drive unit 42 that moves relative to each other in the three mutually orthogonal XYZ axis directions, a first arm 44 that rotates around a C axis extending along the Z axis from the lower surface of the linear drive unit 42, and a second arm 46 that rotates around an A axis extending in the XY plane, with one end attached perpendicularly to the first arm. A laser emission mechanism 30 is attached to the other end of the second arm 46, thereby enabling the laser emission mechanism 30 to rotate around the A axis.

[0024] As shown in Figure 2, the control device 100 includes, as an example, a main control unit 110 that outputs drive commands to the components of the laser processing apparatus 1 (described later) based on a processing program, a movement command generation unit 120 that generates movement commands for moving the laser emission mechanism 30 using values ​​detected from a gap sensor (nozzle 32), a display unit 130 that displays various parameters, and an input interface 140 that allows manual input of information for modifying the processing program and various parameters. The control device 100 is configured such that the main control unit 110 is connected to the laser oscillator 10, the workpiece holding mechanism 20, and the transport mechanism 40 by wire or wireless, and controls the operation of the entire laser processing apparatus 1 by exchanging signals with these peripheral devices.

[0025] As an example, the main control unit 110 has the function of extracting information such as the processing path and processing conditions from the processing program and outputting an output command signal to the laser oscillator 10 to command the output of the processing laser beam LB. The main control unit 110 also has the function of extracting information such as the position of the irradiation point FP of the processing laser beam LB, the position of the laser emission mechanism 30, and the processing vector (described later) from the processing program and outputting a processing position command signal to the workpiece holding mechanism 20 and the transport mechanism 40 to command the relative movement between the workpiece W and the laser emission mechanism 30.

[0026] The movement command generation unit 120 has the function of generating an approach command to move the laser emission mechanism 30 from the control start position toward the laser irradiation point on the workpiece to the boundary gap point detected by the gap sensor, and a processing start point movement command to move the laser emission mechanism from the boundary gap point to the processing start point within the detection range of the gap sensor. The approach command and processing start point movement command generated by the movement command generation unit 120 are sent to the main control unit 110 as an example, where they are converted into individual drive commands for each component of the laser processing apparatus 1 and output.

[0027] Next, using Figures 3 to 6, we will explain the specific operation of the processing start point movement control method executed by the control device of the laser processing apparatus according to the first embodiment.

[0028] Figure 3 is a flowchart illustrating the overview of the processing start point movement control method executed by the control device in the laser processing apparatus according to the first embodiment. Figure 4 is a flowchart illustrating the overview of the approach routine shown in Figure 3. Figure 5 is a flowchart illustrating the overview of the processing start point movement routine shown in Figure 3.

[0029] Furthermore, Figure 6A is a partial front view showing an overview of the positional relationship between the laser emission mechanism and the workpiece at the start of the approach routine. Figure 6B is a partial front view showing an overview of the positional relationship between the laser emission mechanism and the workpiece at the end of the approach routine. Figure 6C is a partial front view showing an overview of the positional relationship between the laser emission mechanism and the workpiece at the start of the machining start point movement routine. Figure 6D is a partial front view showing an overview of the positional relationship between the laser emission mechanism and the workpiece at the end of the machining start point movement routine.

[0030] In the following explanation, the "position" or "point" of the laser emission mechanism 30 refers to the central point of the nozzle 32's output port (for example, the nozzle tip point NP, which is the intersection of the tip of the nozzle 32 and the central axis CA in Figures 6A to 6D), representing the entire laser emission mechanism 30 as a single point. Furthermore, the angle between the line passing through the processing start point PP and the laser irradiation point FP and the normal to the workpiece W at the laser irradiation point FP is defined as the "tilt angle θ" of the laser emission mechanism 30.

[0031] Furthermore, the "unit vector UV" of the laser emission mechanism 30 is defined as a vector with a predetermined length that starts from the nozzle tip point NP of the laser emission mechanism 30 and runs along the central axis of the laser emission mechanism 30. The "processing vector PV" is defined as a vector that starts from the processing start point PP and runs along the line passing through the processing start point PP and the laser irradiation point FP (i.e., in the same direction as the inclination angle θ) and has the same length as the unit vector UV. By defining these vectors, it becomes possible to calculate the displacement amount (correction amount) by multiplying the difference in the detected values ​​obtained from the gap sensor.

[0032] The processing start point movement control method for moving the laser emission mechanism 30, which is executed when performing laser processing with the laser processing apparatus 1 according to the present invention, from a control start point (control start position) SP to a processing start point PP, includes, as shown in Figure 3, an approach routine APR that moves the laser emission mechanism 30 from the control start point SP toward the laser irradiation point FP on the workpiece W to the boundary gap point BP detected by the gap sensor, and a processing start point movement routine STR that moves the laser emission mechanism 30 from the boundary gap point BP to the processing start point PP. In addition to information on the position and orientation of the laser emission mechanism 30 related to laser processing, information on processing conditions such as the output and speed of the processing laser beam LB is also passed between the approach routine APR and the processing start point movement routine STR.

[0033] In the approach routine APR, as an example shown in Figure 4, the main control unit 110 obtains information on the position coordinates of the nozzle tip point NP in the current laser emission mechanism 30 from, for example, the transport mechanism 40 (step S1), and sets this as the control start point SP. Next, the main control unit 110 analyzes, for example, the processing program to obtain the irradiation position coordinates (laser irradiation point FP) of the processing laser beam LB on the workpiece W (step S2). An example of the positional relationship between the laser emission mechanism 30 and the workpiece W at this time is shown in Figure 6A.

[0034] Next, the main control unit 110 sends the data of the control start point SP and the laser irradiation point FP that it has acquired to the movement command generation unit 120. Upon receiving this data, the movement command generation unit 120 generates an approach command for the transport mechanism 40 to move linearly between the control start point SP and the laser irradiation point FP, based on the coordinate values ​​of the two points. The movement command generation unit 120 then sends the generated approach command to the main control unit 110 (step S3).

[0035] Next, the main control unit 110 outputs an approach command to the transport mechanism 40 (step S4) and determines whether a detection signal from the gap sensor has been input at predetermined control clock intervals (i.e., whether the nozzle tip point NP has entered the detectable area DA by the gap sensor at a predetermined distance from the surface of the workpiece W shown in Figure 6A) (step S5).

[0036] In step S5, if it is determined that no detection signal has been received from the gap sensor, the main control unit 110 returns to step S4 and continues to output the approach command. This repeatedly performs the approach operation of the laser emission mechanism 30 to the workpiece W until the gap sensor begins to detect the gap value (i.e., until it begins to output a detection signal). At this time, the movement speed of the laser emission mechanism 30 during the approach operation may be set to be greater than that of the machining start point movement operation described later.

[0037] On the other hand, in step S5, if it is determined that a detection signal has been input from the gap sensor, the main control unit 110 receives the coordinate value of the nozzle tip point NP in the current laser emission mechanism 30 from the transport mechanism 40, saves the nozzle tip point NP as a "boundary gap point BP" located at the boundary of the detectable area DA (step S6), and terminates the approach routine. An example of the positional relationship between the laser emission mechanism 30 and the workpiece W at this time is shown in Figure 6B.

[0038] Next, in the machining start point movement routine STR, as shown in Figure 5 as an example, the main control unit 110 receives information on the boundary gap point BP from the approach routine APR (step S7), and obtains a unit vector UV from the transport mechanism 40 based on the position coordinates of the nozzle tip point NP in the current laser emission mechanism 30 and the central axis CA (step S8). Subsequently, the main control unit 110 analyzes the machining program, for example, and defines a virtual beam axis VA based on the laser irradiation point FP on the workpiece W and the nozzle tip point NP of the laser emission mechanism 30 at the start of machining (i.e., the machining start point PP), and obtains a machining vector PV in the direction along this axis (step S9).

[0039] Next, the main control unit 110 sends the data of the current unit vector UV and the processing vector PV at the processing start point PP, which it has acquired, to the movement command generation unit 120. The movement command generation unit 120 receives this data, calculates the difference between the unit vector UV and the processing vector PV as vectors (step S10), and generates a processing start point movement command that includes coordinate movement and orientation change of the laser emission mechanism 30 to cancel out the difference (i.e., to make the starting point and direction of the unit vector UV and the processing vector PV coincide). The movement command generation unit 120 then sends the generated processing start point movement command to the main control unit 110 (step S11). An example of the positional relationship between the unit vector UV of the laser emission mechanism 30 and the processing vector PV at the processing start point PP at this time is shown in Figure 6C.

[0040] Next, the main control unit 110 outputs a processing start point movement command to the transport mechanism 40 (step S12), and determines at predetermined control clock intervals whether the unit vector UV and the processing vector PV match (i.e., whether the angle between the nozzle tip point NP and the central axis CA of the current laser emission mechanism 30 matches the processing start point PP and the virtual beam axis VA) (step S13).

[0041] In step S13, if the main control unit 110 determines that the current unit vector UV does not match the machining vector PV in terms of position and direction, it returns to step S12 and continues to output the machining start point movement command. As a result, the machining start point movement operation of the laser emission mechanism 30 is repeatedly executed until the unit vector UV matches the machining vector PV, that is, until the laser emission mechanism 30 takes the posture specified (should take) at the machining start point PP in the machining program.

[0042] On the other hand, in step S13, if the main control unit 110 determines that the current unit vector UV matches the processing vector PV in terms of position and direction, it saves the control information, including the coordinate values ​​of the nozzle tip point NP of the laser emission mechanism 30 and the attitude (tilt angle θ) of the central axis CA, as "current settings" (step S14), and terminates the processing start point movement routine. An example of the positional relationship between the laser emission mechanism 30 and the workpiece W at this time is shown in Figure 6D. As a result, at the start of laser processing, the movement control of the laser emission mechanism 30 from the control start point SP shown in Figure 6A to the processing start point PP is completed, and the laser emission mechanism 30 is positioned at the processing start point PP at a predetermined distance PD from the laser irradiation point FP.

[0043] By having the above configuration, the control device for a laser processing apparatus and the processing start point movement control method according to the first embodiment have a function in which the movement command generation unit generates an approach command to move the laser emission mechanism from the control start position to the boundary gap point and a processing start point movement command to move the laser emission mechanism from the boundary gap point to the processing start point. Furthermore, by configuring the processing start point movement command to be calculated based on the coordinate values ​​and vectors of the boundary gap point, the computational load of the movement position of the laser emission mechanism included in the movement command can be reduced in movement control to move the laser emission mechanism to the processing start point.

[0044] Furthermore, the laser processing apparatus including the control device according to the first embodiment of the present invention, as illustrated above, performs movement control to move the laser emission mechanism to the processing start point, and then performs tracing processing control to move the laser emission mechanism using a commonly known gap sensor so that the distance from the workpiece remains constant. In other words, the control device according to the first embodiment is configured to have a function to perform movement control to move the laser emission mechanism to the processing start point, in addition to a function to perform tracing processing control on the laser processing apparatus.

[0045] <Second Embodiment> Figure 7 is a flowchart illustrating the overview of the machining start point movement routine in a machining start point movement control method executed by a control device according to a second embodiment, which is another example of the present invention. Figure 8 is a partial front view illustrating the overview of the distance correction operation of the laser emission mechanism in the machining start point movement routine according to the second embodiment. In the second embodiment, components that can adopt the same or common configurations as those in the first embodiment are denoted by the same reference numerals in the schematic diagrams shown in Figures 1 to 6, and their repeated explanations are omitted.

[0046] As shown in Figure 7, in the machining start point movement routine according to the second embodiment, the main control unit 110 and the movement command generation unit 120 perform the same operations as shown in Figure 5 of the first embodiment from step S7 to step S12. Subsequently, the main control unit 110 determines whether the unit vector UV and the machining vector PV match at predetermined control clock intervals, as in the case of the first embodiment (step S13).

[0047] Then, in step S13, if the main control unit 110 determines that the current unit vector CV(UV) does not match the machining vector PV in terms of position and direction, it returns to step S12 and continues to output the machining start point movement command again, similar to the first embodiment. As a result, the machining start point movement operation of the laser emission mechanism 30 is repeatedly performed until the unit vector CV matches the machining vector PV.

[0048] When performing laser processing while controlling the distance between the laser emission mechanism 30 and the workpiece W using a gap sensor, when actually performing laser processing at the processing start point PP, an operation may be performed to correct the focusing position (focal length) of the processing laser beam LB in the direction of the central axis CA of the laser emission mechanism 30 to an appropriate position based on the value detected from the gap sensor. Therefore, in the second embodiment, after moving the laser emission mechanism 30 to the processing start point PP in the processing program, the above-mentioned distance correction operation in the direction of the central axis CA is performed.

[0049] In other words, in step S13, if the main control unit 110 determines that the current unit vector CV matches the processing vector PV in terms of position and direction, it acquires the current detected value from the gap sensor (step S21) and sends the acquired detected value and information about the gap value based on the focal length in the processing program to the movement command generation unit 120. Upon receiving this, the movement command generation unit 120 further calculates the difference between the gap value calculated from the detected value from the gap sensor and the gap value based on the processing program described above, and generates a correction movement command to move the laser emission mechanism 30 in the direction along the unit vector CV (i.e., the direction along the central axis CA) in order to correct the difference. Then, the movement command generation unit 120 sends the generated correction movement command to the main control unit 110 (step S22).

[0050] Next, the main control unit 110 outputs a correction movement command to the transport mechanism 40 (step S23), and determines whether the correction movement has been completed at predetermined control clock intervals (i.e., whether the current nozzle tip point NP coincides with the correction point CP) (step S24).

[0051] If the main control unit 110 determines in step S24 that the correction movement operation is not yet complete, it returns to step S23 and continues to output the correction movement command again. As a result, the correction movement operation of the laser emission mechanism 30 is repeatedly performed until the position of the nozzle tip point NP of the laser emission mechanism 30 coincides with the correction point CP.

[0052] On the other hand, in step S24, if the main control unit 110 determines that the correction movement operation is complete, it saves the coordinate values ​​of the nozzle tip point NP (i.e., correction point CP) of the corrected laser emission mechanism 30 and the orientation (tilt angle θ) of the central axis CA as the "current settings" (step S14), and terminates the processing start point movement routine. An example of the positional relationship between the laser emission mechanism 30 and the workpiece W due to this series of correction operations is shown in Figure 8. As a result, at the start of laser processing, the position of the laser emission mechanism 30 is corrected in the direction of the central axis CA based on the value detected from the gap sensor, and the distance between the laser emission mechanism 30 and the laser irradiation point FP is set to the correction distance CD.

[0053] By having the above configuration, the control device and processing start point movement control method of the laser processing apparatus according to the second embodiment, in addition to the effects described in the first embodiment, performs a correction operation to correct the position of the laser emission mechanism in the direction along the unit vector so that the processing laser beam has an appropriate focal length at the processing start point. This enables more precise control of the movement of the laser emission mechanism to the processing start point.

[0054] <Third Embodiment> Figure 9 is a flowchart illustrating the overview of the machining start point movement routine in a machining start point movement control method executed by a control device according to a third embodiment, which is yet another example of the present invention. In the third embodiment as well, components that are the same as or common to those in the first and second embodiments are denoted by the same reference numerals in the schematic diagrams shown in Figures 1 to 8, and their repeated explanations are omitted.

[0055] In the third embodiment, the operation of generating movement commands for the laser emission mechanism 30 by the movement command generation unit 120 and the operation of outputting commands to the transport mechanism 40 etc. by the main control unit 110 are performed simultaneously and in parallel, compared to the example shown in the first embodiment. That is, as shown in Figure 9, in the machining start point movement routine according to the third embodiment, the main control unit 110 takes over boundary gap point BP information from the approach routine APR (step S7) and obtains the machining vector PV in the same way as in the first embodiment (step S9).

[0056] Next, the main control unit 110 acquires a unit vector UV from the transport mechanism 40, for example, based on the current position coordinates of the nozzle tip point NP and the central axis CA of the laser emission mechanism 30 (step S31). Subsequently, the main control unit 110 sends the acquired data of the current unit vector UV and processing vector PV to the movement command generation unit 120. The movement command generation unit 120 receives this data and calculates the minute time difference between the unit vector UV and the processing vector PV as vectors per minute unit time based on a predetermined control clock (step S32). It then generates a minute time movement command that includes coordinate movement and attitude change of the laser emission mechanism 30 to cancel out the minute time difference. Finally, the movement command generation unit 120 sends the generated minute time movement command to the main control unit 110 (step S33).

[0057] Next, the main control unit 110 outputs a minute time movement command to the transport mechanism 40 (step S34), and determines whether the unit vector UV and the processing vector PV match at each predetermined control clock cycle (step S13).

[0058] In step S13, if the main control unit 110 determines that the current unit vector UV does not match the processing vector PV in terms of position and direction, it returns to step S31 to acquire the current unit vector UV again and executes the operations from steps S32 to S34. As a result, the movement operation to the laser emission mechanism 30 is repeatedly performed at minute unit time intervals until the unit vector UV matches the processing vector PV.

[0059] On the other hand, in step S13, if the main control unit 110 determines that the current unit vector UV matches the processing vector PV in terms of position and direction, it saves the information for control, including the coordinate values ​​of the nozzle tip point NP of the laser emission mechanism 30 and the attitude (tilt angle θ) of the central axis CA, as "current settings" (step S14), similar to the first embodiment, and terminates the processing start point movement routine. As a result, at the start of laser processing, the movement control of the laser emission mechanism 30 from the control start point SP to the processing start point PP shown in Figure 6A is terminated.

[0060] In the calculation operation of the minute time difference shown in step S32, the minute time difference can be calculated, for example, as the maximum amount of movement that can be advanced per unit time toward the machining start point PP along the line connecting the current nozzle tip point NP (boundary gap point BP at the start of control) and the machining start point PP. Alternatively, the amount of movement of the laser emission mechanism 30 per unit time may be predetermined, and this may be determined as the amount of movement from the current nozzle tip point NP along the line connecting the current nozzle tip point NP and the machining start point PP as described above.

[0061] By having the above configuration, the control device and processing start point movement control method of the laser processing apparatus according to the third embodiment can reduce the overall control time compared to the case where the movement command is generated and then the command is output, by simultaneously executing the operation of generating movement commands for the laser emission mechanism by the movement command generation unit and the operation of outputting commands to the transport mechanism etc. by the main control unit.

[0062] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. Within the scope of the invention, any component of the embodiments can be modified, or any component of the embodiments can be omitted. For example, the specific examples shown in the first to third embodiments may be applied by combining their respective features. [Explanation of symbols]

[0063] 1. Laser processing device 10. Laser Oscillator 20 Workpiece holding mechanism 30. Laser emission mechanism (processing head) 32 nozzles 34 transmission lines 40 Conveying mechanism 42 Linear drive unit 44 First Arm 46. ​​Second Arm 100 Control device 110 Main Control Unit 120 Movement command generation section 130 Display section 140 Input Interfaces

Claims

1. A control device for controlling the operation of a laser processing apparatus, which includes a laser emission mechanism that emits processing laser light in a direction along a unit vector, and a gap sensor provided on the laser emission mechanism, The laser processing apparatus includes a main control unit that outputs drive commands based on a processing program, A movement command generation unit generates a movement command for moving the laser emission mechanism using the value detected from the gap sensor, Includes, The movement command generation unit has the function of generating an approach command to move the laser emission mechanism from the control start position toward the laser irradiation point on the workpiece to the boundary gap point detected by the gap sensor, and a machining start point movement command to move the laser emission mechanism from the boundary gap point to a machining start point within the detection range of the gap sensor. The command to move the machining start point includes a change in orientation that causes the unit vector at the boundary gap point to match the machining vector at the machining start point. Control device.

2. The machining start point movement command further includes distance correction, which changes the machining start point in a direction along the machining vector based on the value detected from the gap sensor. The control device according to claim 1.

3. The command generation operation in the movement command generation unit and the movement operation of the laser emission mechanism by the main control unit are executed simultaneously. The control device according to claim 1 or 2.

4. A laser processing apparatus that performs laser processing by irradiating a workpiece with processing laser light, A workpiece holding mechanism for holding the workpiece, A laser emission mechanism that emits the processing laser light in a direction along a unit vector, A gap sensor provided in the laser emission mechanism, A transport mechanism that moves the laser emission mechanism relative to the workpiece holding mechanism, A control device that controls the operation of each component of the laser processing apparatus, Includes, The control device further includes a main control unit that outputs drive commands to each component of the laser processing apparatus based on a processing program, and a movement command generation unit that generates movement commands for moving the laser emission mechanism using values ​​detected from the gap sensor. The movement command generation unit has the function of generating an approach command to move the laser emission mechanism from the control start position toward the laser irradiation point on the workpiece to the boundary gap point detected by the gap sensor, and a machining start point movement command to move the laser emission mechanism from the boundary gap point to a machining start point within the detection range of the gap sensor. The command to move the machining start point includes a change in orientation that causes the unit vector at the boundary gap point to match the machining vector at the machining start point. Laser processing equipment.

5. The machining start point movement command further includes distance correction, which changes the machining start point in a direction along the machining vector based on the value detected from the gap sensor. The laser processing apparatus according to claim 4.

6. The command generation operation in the movement command generation unit and the movement operation of the laser emission mechanism by the main control unit are executed simultaneously. The laser processing apparatus according to claim 4 or 5.

7. A laser processing apparatus comprising a laser emission mechanism that emits processing laser light in a direction along a unit vector, and a gap sensor provided on the laser emission mechanism, moves the laser emission mechanism to the processing start point of a tracing processing control, a method for controlling the movement of the processing start point of a laser emission mechanism, An approach routine that moves the laser emission mechanism from the control start position toward the laser irradiation point on the workpiece to the boundary gap point where the gap sensor begins to detect, A machining start point movement routine for moving the laser emission mechanism from the boundary gap point to a machining start point that is within the detection range of the gap sensor, Includes, The machining start point movement routine includes a posture change step that makes the unit vector at the boundary gap point match the machining vector at the machining start point. A method for controlling the movement of the processing start point of a laser emission mechanism.

8. The machining start point movement routine further includes a distance correction step of changing the machining start point in a direction aligned with the machining vector based on a value detected from the gap sensor. A method for controlling the movement of the processing start point of a laser emission mechanism according to claim 7.

9. In the aforementioned processing start point movement routine, the generation operation of the movement command for the laser emission mechanism and the actual command output operation are executed simultaneously. A method for controlling the movement of the processing start point of a laser emission mechanism according to claim 7 or 8.

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