Control device, laser processing device equipped therewith, and method for controlling the displacement of the processing start point of the laser emission mechanism of the laser processing device

Abstract

The present invention relates to a control device for a laser processing device, comprising a laser emission mechanism that emits a processing laser beam in a direction along a unit vector, and a distance sensor provided in the laser emission mechanism, and a method for controlling the displacement of a processing start point. The control device includes a main control unit that, based on a processing program, issues a drive command to a component of the laser processing device; and a displacement command generation unit that, using a detection value from the distance sensor, generates a displacement command to move the laser emission mechanism.The displacement command generation unit has a function for generating an approach command to move the laser emission mechanism from a control start point toward a laser irradiation point to a boundary distance point where the distance sensor begins detection, and a machining start point displacement command to move the laser emission mechanism from the boundary distance point to a machining start point within a detection range of the distance sensor. The machining start point displacement command includes a position change that aligns the unit vector at the boundary distance point with a machining vector at the machining start point.

Description

TECHNICAL AREA

[0001] The present invention relates to a control device for a laser processing device, in particular a control device with a function for performing motion control in order to move a laser emission mechanism such as a processing head to a processing start point. GENERAL STATE OF THE ART

[0002] A laser processing device, such as a laser cutting machine or a laser welding machine, can perform a predetermined processing operation by transmitting a processing laser beam emitted by a laser oscillator to irradiate a workpiece with the processing laser beam and by moving the processing laser beam and the workpiece relative to each other. In such a laser processing device, a control operation is known for irradiating the workpiece with the processing laser beam, in which the laser processing is carried out according to a processing program by detecting a distance between the workpiece and a laser emission mechanism, such as a processing head, using a distance sensor provided in the laser emission mechanism, and by maintaining the detected distance at a predetermined value.

[0003] Regarding laser processing devices that perform such a control operation, patent document 1, for example, discloses a laser processing device configured to rotate a processing nozzle about a predetermined axis of rotation and to perform laser processing on a workpiece with a laser beam emitted from the processing nozzle, while the processing nozzle is moved relative to the workpiece according to a processing program, wherein the laser processing device comprises a three-dimensional motion unit that moves the processing nozzle relative to the workpiece in three-dimensional directions; a rotary unit that rotates the processing nozzle about the axis of rotation; a distance measurement detection unit that detects the extent of the distance between the processing nozzle and the workpiece; and a rotation position detection unit that detects a rotation position of the axis of rotation brought about by the rotary unit.and a command calculation unit that generates a command signal based on the detected distance and rotational position to maintain a constant distance. In patent document 1, the three-dimensional motion unit moves the processing nozzle relative to the workpiece in three-dimensional directions based on the command signal. Such a laser processing device makes it possible to reduce errors in the workpiece's shape by controlling the distance. LITERATURE LIST PATENT LITERATURE

[0004] Patent literature example 1: JP 2017-192970 A Brief description of the problem the invention is intended to solve.

[0005] When laser processing is carried out as described above, while tracking control is performed to keep the extent of the distance between the processing nozzle and the workpiece constant based on a detection value from the distance measurement detection unit, at the beginning of the processing an approach operation is carried out, in which a laser emission mechanism is brought from a predetermined control starting point closer to a detection area in which the distance measurement detection unit can detect the extent of the distance, a rotation operation in which the laser emission mechanism is rotated about a predetermined rotation axis (B-axis), and a correction operation in which the position of a unit vector is corrected after the rotation (a vector defined in a direction along a central axis of the laser emission mechanism with a nozzle tip as the starting point).Furthermore, after the correction operation, processing control of the laser processing is carried out based on the processing program.

[0006] In the sequence of operations described above, for example, during the approach operation, position control is performed based on the control start point to move the laser emission mechanism closer to the workpiece. Meanwhile, during the correction operation, a correction movement of the processing nozzle is determined with an intersection point between the workpiece and the central axis of the processing nozzle as the reference position, and position control is performed to move the position of the nozzle tip from this intersection point in the direction of the unit vector, according to the correction movement.

[0007] In this case, in a control device that governs the operation of the laser processing device, the control starting point during approach mode represents the reference position for the position control that moves the laser emission mechanism, whereas the intersection point between the workpiece and the central axis of the processing nozzle is the reference position for correction mode. Therefore, when transitioning from approach mode to correction mode, the control device must calculate a position of the laser emission mechanism that corresponds to the position control during correction mode, after receiving the reference position from a control command. This results in an increased computational load and a time delay during the transition to correction mode.

[0008] For these reasons, there is a need for a control device capable of reducing the burden of calculating a movement position of the laser emission mechanism contained in a motion command when tracking control is performed during motion control that moves the laser emission mechanism (for example, a processing head) to a processing start point, in order to keep the distance between the workpiece and the laser emission mechanism constant based on the detection value from the distance sensor. MEANS TO SOLVENT THE PROBLEM

[0009] A control device for controlling the operation of a laser processing device, which has a laser emission mechanism for emitting a processing laser beam in a direction along a unit vector and a distance sensor provided in the laser emission mechanism, according to one aspect of the invention, comprises a main control unit which, based on a processing program, issues a drive command to components of the laser processing device; and a motion command generation unit which, using a detection value from the distance sensor, generates a motion command to move the laser emission mechanism.The motion command generation unit has a function for generating an approach command to move the laser emission mechanism from a control start point toward a laser irradiation point on a workpiece to a boundary distance point where the distance sensor begins detection, and a machining start point movement command to move the laser emission mechanism from the boundary distance point to a machining start point within a detection range of the distance sensor. The machining start point movement command includes a position change to align the unit vector at the boundary distance point with a machining vector at the machining start point.

[0010] Furthermore, a laser processing device for performing laser processing by irradiating a workpiece with a processing laser beam, according to another aspect of the present invention, comprises a laser oscillator that oscillates the processing laser beam; a workpiece holding mechanism that holds the workpiece; a laser emission mechanism that emits the processing laser beam in a direction along a unit vector; a distance sensor provided in 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 of the components of the laser processing device.The control device further comprises a main control unit, which issues a drive command to each component of the laser processing device based on a processing program, and a motion command generation unit, which generates a motion command to move the laser emission mechanism using a detection value from the distance sensor. The motion command generation unit has a function for generating an approach command to move the laser emission mechanism from a control start point towards a laser irradiation point on the workpiece to a limit distance point where the distance sensor begins detection, and a processing start point movement command to move the laser emission mechanism from the limit distance point to a processing start point within a detection range of the distance sensor.The machining start point movement command includes a position change to align the unit vector at the boundary distance point with a machining vector at the machining start point.

[0011] Furthermore, a method for controlling the movement of a processing start point for a laser emission mechanism, which moves the laser emission mechanism of a laser processing device, the laser emission mechanism having a processing laser beam for emitting a processing laser beam in a direction along a unit vector and a distance sensor provided in the laser emission mechanism, to a processing start point of a tracking processing control, according to another aspect of the present invention, comprises an approach program for moving the laser emission mechanism from a control start position in the direction of a laser irradiation point on a workpiece to a limit distance point at which the distance sensor begins detection; and a processing start point movement program for moving the laser emission mechanism from the limit distance point to a processing start point within a detection range of the distance sensor.The machining start point movement program includes a position change step to bring the unit vector at the boundary distance point into alignment with a machining vector at the machining start point. IMPACT OF THE INVENTION

[0012] According to one aspect of the present invention, the motion command generation unit has a function for generating an approach command to move the laser emission mechanism from the control start point to the boundary distance point, and a machining start point motion command to move the laser emission mechanism from the boundary distance point to the machining start point, and is configured to calculate the machining start point motion command based on the coordinate values ​​and vector of the boundary distance point, so that in the motion control that moves the laser emission mechanism to the machining start point, the load of calculating a movement position of the laser emission mechanism contained in the motion command can be reduced. SIMPLE DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic view showing the structure of a laser processing device with a control device according to a first embodiment; Fig. 2 is a block diagram that provides an example of the structure of the in Fig. The laser processing device shown in 1 is shown; Fig. Figure 3 is a flowchart showing an overview of a method for controlling the movement of a processing start point, which is carried out by the control device in the laser processing device according to the first embodiment; Fig. 4 is a flowchart that provides an overview of a process in Fig. The approach program shown in section 3 demonstrates; Fig. 5 is a flowchart that provides an overview of a process in Fig. The processing start point movement program shown in section 3 is displayed; Fig. Figure 6A is a partial front view showing an overview of a positional relationship between a laser emission mechanism and a workpiece at the beginning of the approach program; Fig. 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 program; Fig. 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 motion program; Fig. 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 motion program; Fig. Figure 7 is a flowchart showing an overview of a machining start point movement program in a method for controlling the movement of a machining start point, which is carried out by a control device according to a second embodiment, which is another example of the invention; Fig. Figure 8 is a partial front view showing an overview of a distance correction operation of the laser emission mechanism in the processing start point movement program according to the second embodiment; and Fig. Figure 9 is a flowchart showing an overview of a machining start point movement program in a method for controlling the movement of a machining start point, which is carried out by a control device according to a third embodiment, which is yet another example of the invention. WAY(S) TO EXECUTIVE THE INVENTION

[0013] With reference to the drawings, embodiments of a laser processing device with a control device according to a typical example of the present invention and a method for controlling the movement of a processing start point of a laser emission mechanism (for example, a processing head) in the laser processing device are described below. First embodiment

[0014] Fig. Figure 1 is a schematic view showing the setup of a laser processing device with a control device according to a first embodiment, which represents a typical example of the present invention. Furthermore, Fig. 2. A block diagram that provides an example of the structure of the in Fig. Figure 1 shows the laser processing device.

[0015] As in Fig. As shown in Figure 1, a laser processing device 1 comprises, as an example, a laser oscillator 10 that oscillates a processing laser beam LB; a workpiece holding mechanism 20 that holds a workpiece W; a laser emission mechanism (for example, a processing head) 30 that emits the processing laser beam LB to the workpiece W; a transport mechanism 40 that moves the laser emission mechanism 30 relative to the workpiece holding mechanism 20; and a control device 100 that controls a predetermined laser processing activity on the workpiece W.

[0016] The laser processing device described here can be, for example, any processing device that performs a predetermined processing operation, such as laser welding, laser cutting, laser drilling (core drilling), laser marking, laser cutting, or laser hardening, by irradiating the workpiece W with a processing laser beam.

[0017] For the laser oscillator 10, a laser oscillation source is used that has a wavelength with high absorption efficiency corresponding to the material W of the workpiece to be processed. Examples of lasers capable of fiber transmission, such as a YAG laser, a YVO4 laser, a fiber laser, and a disk laser, can be used for the laser oscillator 10. Furthermore, the processing laser beam LB, which is emitted by the laser oscillator 10, is transmitted, for example, via a transmission path 34 such as an optical fiber, to the laser emission mechanism 30.

[0018] The workpiece holding mechanism 20, for example, includes a clamping mechanism (not shown) for attaching the workpiece W and is designed as a machining table that is movable in three axis directions XYZ, as shown in the figure, while gripping and fixing the workpiece. Furthermore, the workpiece holding mechanism 20 can, for example, include not only a mechanism for moving the workpiece W in the three axis directions, but also a rotary mechanism (for example, a configuration known as a B-axis along a Y-axis or a C-axis along a Z-axis).

[0019] The laser emission mechanism 30 is designed as an example of a processing head into which the processing laser beam LB is introduced from one end (the upper end) via the transmission path 34, such as an optical fiber, and from which the processing laser beam LB is emitted from a nozzle 32 at the other end (the lower end) towards the workpiece. In this case, the processing laser beam LB is focused by a focusing lens (not shown) located inside the laser emission mechanism 30 onto a predetermined beam diameter at a laser irradiation point FP on the workpiece W.

[0020] In the present invention, the nozzle 32, in addition to serving as an emission aperture for the processing laser beam LB in the laser emission mechanism 30, also functions as a distance sensor, detecting a distance D between a lower end of the laser emission mechanism 30 (the nozzle 32) and the workpiece W. A capacitive sensor can be used as an example for the nozzle 32.

[0021] Now, in the example that is in Fig. Figure 1 shows an example case where the nozzle 32 is provided as part of an electrode of the capacitive sensor. However, as described above, any sensor can be used as long as it can detect a distance between the workpiece W and the laser emission mechanism 30, and such a sensor can be designed to be attached directly to the laser emission mechanism 30. In this case, for example, a method for determining a distance between the laser emission mechanism 30 and the workpiece W can be used in which a reference point for position measurement is provided on a part of the laser emission mechanism 30, and a distance measured by the sensor is corrected using a relative position between the reference point and the sensor.

[0022] The transport mechanism 40 comprises, as an example, a linear drive unit 42 that moves relative to each other in the three mutually orthogonal axes XYZ; a first arm 44 that rotates about the C-axis, which extends from a lower surface of the linear drive unit 42 along the Z-axis; and a second arm 46, one end of which is attached orthogonally to the first arm and which rotates about an A-axis extending in an XY plane. Furthermore, the laser emission mechanism 30 is attached to the other end of the second arm 46 and is rotatable about the A-axis.

[0023] As in Fig. As shown in Figure 2, the control device 100 has, as an example, a main control unit 110 which, based on a processing program, issues a drive command to components of the laser processing device 1, which will be described later; a motion command generation unit 120 which, using a detection value from the distance sensor (of the nozzle 32), generates a motion command to move the laser emission mechanism 30; a display unit 130 which displays various parameters and the like; and an input interface 140 which allows manual input of information to modify the processing program or various parameters.Furthermore, the main control unit 110 in the control device 100 is connected via wire or wireless connection to the laser oscillator 10, the workpiece holding mechanism 20 and the transport mechanism 40 and controls the entire operation of the laser processing device 1 by exchanging signals with these peripheral devices.

[0024] The main control unit 110, for example, has a function for extracting information regarding a machining path, machining conditions, and the like from the machining program and for outputting an output command signal to instruct the output of the machining laser beam LB to the laser oscillator 10. Furthermore, the main control unit 110 also has a function for extracting information regarding the position of the irradiation point FP of the machining laser beam LB or the position of the laser emission mechanism 30, machining vectors (which will be described later), and the like from the machining program and for outputting a machining position command signal to instruct the workpiece holding mechanism 20 and the transport mechanism 40 to perform a relative movement between the workpiece W and the laser emission mechanism 30.

[0025] The motion command generation unit 120 has a function for generating an approach command to move the laser emission mechanism 30 from a control start position in the direction of the laser irradiation point on a workpiece to a limit distance point where the distance sensor begins detection, and a machining start point movement command to move the laser emission mechanism from the limit distance point to a machining start point within a detection range of the distance sensor. As an example, each of the approach command and the machining start point movement command generated by the motion command generation unit 120 is sent to the main control unit 110 and converted in the main control unit 110 into an individual drive command for each of the components of the laser machining device 1, and the individual drive command is output.

[0026] Next, with reference to Fig. 3 to 6 describe a specific operating mode of the method for controlling the movement of the processing start point, which is carried out by the control device for the laser processing device according to the first embodiment.

[0027] Fig. Figure 3 is a flowchart that provides an overview of a method for controlling the movement of a processing start point, which is carried out by the control device in the laser processing device according to the first embodiment. Furthermore, Fig. 4. A flowchart that provides an overview of a process in Fig. The approach program shown in section 3 demonstrates this. Furthermore, it is Fig. 5. A flowchart that provides an overview of a process in Fig. The 3 shown processing start point movement program is shown.

[0028] Furthermore, Fig. Figure 6A shows a partial front view illustrating an overview of the positional relationship between a laser emission mechanism and a workpiece at the start of the approach program. Furthermore, Fig. Figure 6B shows a partial front view illustrating the positional relationship between the laser emission mechanism and the workpiece at the end of the approach program. Furthermore, Fig. Figure 6C shows a partial front view that provides an overview of the positional relationship between the laser emission mechanism and the workpiece at the beginning of the machining start point movement program. Furthermore, Fig. 6D shows a partial front view that provides an overview of the positional relationship between the laser emission mechanism and the workpiece at the end of the machining start point motion program.

[0029] Incidentally, the “position” or “point” of the laser emission mechanism 30 in the following description refers to the entire laser emission mechanism 30 represented as a single point and is defined as the “position” or “point” being the center point of the emission aperture of the nozzle 32 (for example, a nozzle tip point NP, which is an intersection point between a tip of the nozzle 32 and a central axis CA, in Fig. 6A to 6D). Furthermore, an angle between a line passing through a processing start point PP and the laser irradiation point FP, and a normal to the workpiece W at the laser irradiation point FP, is defined as a “tilt angle θ” of the laser emission mechanism 30.

[0030] Furthermore, a "unit vector UV" of the laser emission mechanism 30 is defined as a vector of a predetermined length in a direction along the central axis of the laser emission mechanism 30, with the nozzle tip point NP of the laser emission mechanism 30 described above as its starting point. Additionally, a "processing vector PV" is defined as a vector of the same length as the unit vector UV in a direction along the line described above, passing through the processing start point PP and the laser irradiation point FP (that is, in the same direction as the tilt angle θ described above), with the processing start point PP as its starting point. Defining these vectors makes it possible to calculate a displacement magnitude (a correction magnitude) by multiplying the difference between detection values ​​obtained from the distance sensor.

[0031] The method for controlling the movement of the processing start point in order to move the laser emission mechanism 30 from a control start point (a control start position) SP to the processing start point PP, which is executed when laser processing is carried out by the laser processing device 1 according to the present invention, comprises as shown in Fig. Figure 3 shows an approach program APR for moving the laser emission mechanism 30 from the control start point SP towards the laser irradiation point FP on the workpiece W to a limit distance point BP, where the distance sensor begins detection, and a processing start point movement program STR for moving the laser emission mechanism 30 from the limit distance point BP to the processing start point PP. Incidentally, in addition to information regarding the position or orientation of the laser emission mechanism 30 in connection with laser processing, information regarding processing conditions such as the output power, speed, or similar parameters of the processing laser beam LB is also exchanged between the approach program APR and the processing start point movement program STR.

[0032] In the APR approach program, the main control unit 110 achieves the following: Fig. Figure 4 shows, for example, that information regarding the current position coordinates of the nozzle tip point NP in the laser emission mechanism 30 is obtained from the transport mechanism 40 (step S1) and sets the position coordinates as the control start point SP. Next, the main control unit 110 analyzes, for example, the machining program to obtain the irradiation position coordinates (the laser irradiation point FP) of the machining 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 in this case is shown in Figure 4. Fig. 6A shown.

[0033] The main control unit 110 then sends the acquired data of the control start point SP and the laser irradiation point FP to the motion command generation unit 120. The motion command generation unit 120, having received the data, uses the coordinate values ​​of the control start point SP and the laser irradiation point FP to generate an approach command for a linear movement of the transport mechanism 40 between the control start point SP and the laser irradiation point FP. The motion command generation unit 120 then sends the generated approach command back to the main control unit 110 (step S3).

[0034] The main control unit 110 then issues an approach command to the transport mechanism 40 (step S4) and determines with each predetermined control pulse whether a detection signal has been input from the distance sensor (i.e., whether the nozzle tip point NP is in a Fig. 6A area DA shown, which is detectable by the distance sensor, has reached a predetermined distance from the surface of the workpiece W) (step S5).

[0035] If step S5 determines that no detection signal was received from the distance sensor, the main control unit 110 returns to step S4 and resumes issuing the approach command. Accordingly, the approach operation of the laser emission mechanism 30 to the workpiece W is repeatedly executed until the distance sensor begins to detect a distance value (i.e., until the distance sensor begins to output a detection signal). In this case, the movement speed of the laser emission mechanism 30 during the approach operation can be set to be higher than that of the machining start point movement operation described later.

[0036] If, on the other hand, step S5 determines that a detection signal has been input from the distance sensor, the main control unit 110 receives the current coordinate values ​​of the nozzle tip point NP in the laser emission mechanism 30 from the transport mechanism 40, stores the coordinate values ​​as the "limit distance point BP" where the nozzle tip point NP is located at the boundary of the detectable area DA (step S6), and terminates the approach program. An example of the positional relationship between the laser emission mechanism 30 and the workpiece W in this case is shown in Fig. 6B shown.

[0037] Next, the main control unit 110 takes over the STR machining start point movement program as described in Fig. As an example, information regarding the boundary distance point BP is shown in step S7 of the approach program PR, and the unit vector UV is obtained, for example, from the transport mechanism 40 based on the current position coordinates of the nozzle tip point NP in the laser emission mechanism 30 and the central axis CA (step S8). Subsequently, the main control unit 110 analyzes, for example, the machining program to define an imaginary beam axis VA based on the laser irradiation point FP on the workpiece W and the nozzle tip point NP (i.e., the machining start point PP) of the laser emission mechanism 30 at the beginning of the machining process, and obtains the machining vector PV in a direction along the virtual beam axis VA (step S9).

[0038] The main control unit 110 then sends the acquired data of the current unit vector UV and the processing vector PV at the processing start point PP to the motion command generation unit 120. The motion command generation unit 120, having received the data, calculates a vector difference between the unit vector UV and the processing vector PV (step S10) and generates a processing start point motion command. This command includes a coordinate movement and a change in the position of the laser emission mechanism 30 to compensate for the difference (that is, to align the points and directions of the unit vector UV and the processing vector PV). The motion command generation unit 120 then sends the generated processing start point motion command back to the main control unit 110 (step S11).An example of a positional relationship between the unit vector UV of the laser emission mechanism 30 and the processing vector PP at the processing start point PP in this case is in . Fig. 6C shown.

[0039] The main control unit 110 then issues the processing start point movement command to the transport mechanism 40 (step S12) and determines with each predetermined control cycle whether the unit vector UV and the processing vector PV have been aligned (i.e., whether the angle of the current nozzle tip point NP and the central axis CA of the laser emission mechanism 30 has been aligned with the processing start point PP and the imaginary beam axis VA) (step S13).

[0040] If, in step S13, it was determined that the current unit vector UV was not aligned with the machining vector PV in terms of position and direction, the main control unit 110 returns to step S12 and resumes issuing the machining start point movement command. Accordingly, the machining start point movement operation of the laser emission mechanism 30 is executed repeatedly until the unit vector UV aligns with the machining vector PV, that is, until the laser emission mechanism 30 assumes a position specified in the machining program at the machining start point PP.

[0041] If, on the other hand, in step S13 it was determined that the current unit vector UV was aligned with the machining vector PV with respect to position and direction, the main control unit 110 stores information for control, including the current coordinate values ​​of the nozzle tip point NP of the laser emission mechanism 30 and the position (the tilt angle θ) of the central axis CA, as the “current setting” (step 14) and terminates the machining start point motion program. An example of the positional relationship between the laser emission mechanism 30 and the workpiece W in this case is shown in Fig. 6D shown. Accordingly, the control of the movement of the laser emission mechanism 30 ends from the one in Fig. 6A shows the control start point SP at the processing start point PP and the laser emission mechanism 30 is positioned at the processing start point PP, which is spaced a predetermined distance PD from the laser irradiation point FP, when the laser processing is started.

[0042] By incorporating the design described above, the motion command generation unit in the control device for the laser processing device and the method for controlling the movement of the processing start point according to the first embodiment has a function for generating an approach command to move the laser emission mechanism from the control start position to the boundary distance point, and a processing start point movement command to move the laser emission mechanism from the boundary start point to the processing start point, and is designed to calculate the processing start point movement command based on the coordinate values ​​and the vector of the boundary start point, so that the load of calculating a movement position of the laser emission mechanism contained in the movement command can be reduced in the motion control that moves the laser emission mechanism to the processing start position.

[0043] Incidentally, the laser processing device, which includes the control device according to the first embodiment of the present invention described above as an example, performs the motion control to move the laser emission mechanism to the processing start point, and then performs the tracking processing control to move the laser emission mechanism so that the distance between the laser emission mechanism and the workpiece is kept constant, using a generally known distance sensor. That is to say, the control device according to the first embodiment is designed such that, in addition to a function to cause the laser device to perform tracking processing control, it has a function to perform the motion control described above to move the laser emission mechanism to the processing start point. Second embodiment

[0044] Fig. Figure 7 is a flowchart that provides an overview of a machining start point movement program in a method for controlling the movement of a machining start point, which is carried out by a control device according to a second embodiment, which is another example of the invention. Furthermore, Fig. Figure 8 shows a partial front view providing an overview of a distance correction operation of the laser emission mechanism in the processing start point movement program according to the second embodiment. Incidentally, in the second embodiment, components are located in the Fig. Schematic views and the like shown in Figures 1 to 6, which may have the same or common structures as in the first embodiment, are designated with the same reference numerals, and a repeated description of them will be omitted.

[0045] As in Fig. As shown in Figure 7, the main control unit 110 and the motion command generation unit 120 perform the same activities in the machining start point motion program according to the second embodiment as those described in Figure 7. Fig. 5 in the first embodiment are shown as activities from step S7 to step S12. Subsequently, the main control unit 110 determines, as in the first embodiment, with each predetermined control pulse, whether the unit vector UV and the processing vector PV have been brought into agreement (step S13).

[0046] If, in step S13, it was determined that a current unit vector CV (UV) does not match the processing vector PV with respect to position and direction, the main control unit 110 returns to step S12, as in the first embodiment, and resumes issuing a processing start point movement command. Accordingly, the processing start point movement operation of the laser emission mechanism 30 is executed repeatedly until the unit vector CV matches the processing vector PV.

[0047] In a case where laser processing is performed while the distance between the laser emission mechanism 30 and the workpiece W is controlled using the distance sensor, an operation can be carried out at the processing start point PP during the actual execution of the laser processing. In this operation, the focusing position (focus distance) of the processing laser beam LB in the direction of the central axis CA of the laser emission mechanism 30 is corrected based on a detection value from the distance sensor so that the focusing position is in a suitable position. Therefore, in the second embodiment, the correction operation described above is carried out in the direction of the central axis CA after the laser emission mechanism 30 has been moved to the processing start point PP in the processing program.

[0048] This means that if, in step S13, it was determined that the current unit vector CV matches the processing vector PV with respect to position and direction, the main control unit 110 obtains a current detection value from the distance sensor (step S21) and sends information regarding the obtained detection value and the distance value, which is based on the focus distance in the processing program, to the motion command generation unit 120. The motion command generation unit 120, having received this information, further calculates a difference between the distance value calculated from the detection value by the distance sensor and the distance value described above, which is based on the processing program, and generates a corrective motion command to move the laser emission mechanism 30 in a direction along the unit vector CV (that is, the direction along the central axis CA) such that the difference is corrected.Then the motion command generation unit 120 sends the generated correction motion command to the main control unit 110 (step S22).

[0049] Subsequently, the main control unit 110 issues the correction movement command to the transport mechanism 40 (step S23) and determines with each predetermined control cycle whether the correction movement is completed (i.e., whether the current nozzle tip point NP has been brought into agreement with a correction point CP) (step S24).

[0050] If step S24 determines that the correction movement operation is not yet complete, the main control unit 110 returns to step S23 and resumes issuing the correction movement command. Accordingly, the correction movement operation of the laser emission mechanism 30 is executed repeatedly until the position of the nozzle tip point NP of the laser emission mechanism 30 matches the correction point CP.

[0051] If, on the other hand, step S24 determines that the correction movement operation is complete, the main control unit 110 stores information for the control, including the coordinate values ​​for the nozzle tip point NP (i.e., the correction point CP) of the laser emission mechanism 30 and the position (the inclination angle θ) of the central axis CA after the correction, as the "current setting" (step S14) and terminates the machining start point movement program. An example of the positional relationship between the laser emission mechanism 30 and the workpiece W resulting from the series of correction operations is shown in Fig. Figure 8 shows that at the beginning of the laser processing, an operation is carried out to correct the position of the laser emission mechanism 30 in the direction of the central axis CA on the basis of the detection value from the distance sensor and to define a distance between the laser emission mechanism 30 and the laser irradiation point FP as the correction distance CD.

[0052] By incorporating the design described above, the control device for the laser processing device and the method for controlling the movement of the processing start point according to the second embodiment perform a correction operation in addition to the effects obtained in the first embodiment, in order to correct the position of the laser emission mechanism in the direction along the unit vector so that the processing laser beam has a suitable focus distance at the processing start point, thereby enabling more precise movement control of the laser emission mechanism to the processing start point. Third embodiment

[0053] Fig. Figure 9 is a flowchart that provides an overview of a machining start point movement program in a method for controlling the movement of a machining start point, which is carried out by a control device according to a third embodiment, which is yet another example of the invention. Incidentally, components in the third embodiment are also included in the diagram. Fig. Schematic views 1 to 8 and the like, which may have the same or common structures as the first embodiment and the second embodiment, are designated with the same reference numerals, and a repeated description of them will be omitted.

[0054] The third embodiment is characterized in that, compared to the example shown in the first embodiment, an operation for generating the motion command for the laser emission mechanism 30 by the motion command generation unit 120 and an operation for issuing the command for the transport mechanism 40 and the like by the main control unit 110 are executed in parallel at the same time. That is, in the machining start point motion program according to the third embodiment, the main control unit 110 takes over as in Fig. 9 shown as in the case of the first embodiment, information regarding the boundary distance point BP is obtained from the approach program APR (step S7) and the processing vector PV is obtained (step S9).

[0055] The main control unit 110 then obtains the unit vector UV from the transport mechanism 40, for example, based on the current position coordinates of the nozzle tip point NP in the laser emission mechanism 30 and the central axis CA (step S31). The main control unit 110 then sends data regarding the current unit vector UV and the processing vector PV, which have been obtained, to the motion command generation unit 120. The motion command generation unit 120, having received the data, calculates a minute time difference as a vector between the unit vector UV and the processing vector PV per minute unit time, based on the predetermined control cycle (step S32), and generates a short-term motion command that includes a coordinate movement and a change in position of the laser emission mechanism 30 to compensate for the minute time difference.Then the motion command generation unit 120 sends the generated short-term motion command to the main control unit 110 (step S33).

[0056] Then the main control unit 110 issues the short-term movement command to the transport mechanism 40 (step S34) and determines with each predetermined control cycle described above whether the unit vector UV and the processing vector PV have been brought into agreement (step S13).

[0057] If, at step S13, it was determined that the current unit vector UV was not aligned with the processing vector PV in terms of position and direction, the main control unit 110 returns to step S31, re-establishes the current unit vector UV, and then executes the operations from step S32 to step S34. Accordingly, the motion operation of the laser emission mechanism 30 is repeated at each minute unit time until the unit vector UV aligns with the processing vector PV.

[0058] If, on the other hand, it was determined in step S13 that the current unit vector UV was aligned with the processing vector PV with respect to position and direction, the main control unit 110, as in the first embodiment, stores information for the control, containing the current coordinate values ​​of the nozzle tip point NP of the laser emission mechanism 30 and the position (the inclination angle θ) of the central axis CA, as the “current setting” (step S14) and terminates the processing start point generation program. Accordingly, the control of the movement of the laser emission mechanism 30 from the point described in step S13 ends. Fig. 6A shows the control start point SP being moved to the processing start point PP when laser processing begins.

[0059] Incidentally, the tiny time difference in the operation to calculate the tiny time difference shown in step S32 can be calculated as the maximum range of motion by which the laser emission mechanism 30 can advance per unit time along a line connecting the current nozzle tip point NP (the limit distance point BP when control is started) and the machining start point PP, in the direction of the machining start point PP. Furthermore, a range of motion of the laser emission mechanism 30 per unit time can be determined in advance and can be defined as a range of motion from the current nozzle tip point NP along the line described above, connecting the current nozzle tip point NP and the machining start point PP.

[0060] By incorporating the design described above, in the control device for the laser processing device and the method for controlling the movement of the processing start point according to the third embodiment, in addition to the effects obtained in the first embodiment, an operation for generating the motion command for the laser emission mechanism by the motion command generation unit and an operation for issuing the command for the transport mechanism and the like by the main control unit are carried out in parallel at the same time, thereby shortening the total control time compared to issuing the command after generating a motion command.

[0061] The invention is not limited to the embodiments shown, but can be modified as appropriate without deviating from the concept of the invention. Within the scope of the present invention, any component of the embodiments can be modified or omitted. For example, the specific examples shown in the first to third embodiments can be applied by combining their respective features. EXPLANATION OF REFERENCE SYMBOLS 1 LASER PROCESSING DEVICE 10 LASER OSCILLATOR 20 Toolholding Mechanism 30 LASER EMISSION MECHANISM (PROCESSING HEAD) 32 NOZZLE 34 TRANSFER PATH 40 TRANSPORT MECHANISM 42 LINEAR DRIVE UNIT 44 FIRST ARM 46 SECOND ARM 100 CONTROL DEVICE 110 MAIN CONTROL UNIT 120 MOVEMENT COMMAND GENERATION UNIT 130 DISPLAY UNIT 140 INPUT INTERFACE QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2017-192970 A

[0004]

Claims

[1] A control device for controlling an operation of a laser processing device comprising a laser emission mechanism for emitting a processing laser beam in a direction along a unit vector and a distance sensor provided in the laser emission mechanism, the control device a main control unit that outputs a drive command to components of the laser processing device based on a processing program; and a movement command generation unit that generates a movement command for moving the laser emission mechanism using a detection value from the distance sensor, wherein the movement command generation unit has a function of generating an approach command to move the laser emission mechanism from a control start point toward a laser irradiation point on a workpiece to a limit distance point at which the distance sensor starts detection, and a machining start point movement command to move the laser emission mechanism from the limit distance point to a machining start point within a detection range of the distance sensor, and the machining start point move command includes a position change to make the unit vector at the limit distance point coincide with a machining vector at the machining start point. [2] The control device according to claim 1, wherein the machining start point movement command further includes a distance correction for changing the machining start point in a direction along the machining vector based on the detection value from the distance sensor. [3] The control device according to claim 1 or 2, wherein the operation for generating the command by the movement command generating unit and the operation for moving the laser emission mechanism by the main control unit are executed in parallel at the same time. [4] Laser processing device for performing laser processing by irradiating a workpiece with a processing laser beam, wherein the laser processing device a workpiece holding mechanism for holding the workpiece; a laser emission mechanism for emitting the machining laser beam in a direction along a unit vector; a distance sensor provided in 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 an operation of each of the components of the laser processing device, wherein the control device further comprises a main control unit that outputs a drive command to each of the components of the laser processing device based on a processing program, and a movement command generation unit that generates a movement command for moving the laser emission mechanism using a detection value from the distance sensor, the movement command generation unit has a function of generating an approach command to move the laser emission mechanism from a control start point toward a laser irradiation point on the workpiece to a limit distance point at which the distance sensor starts detection, and a machining start point movement command to move the laser emission mechanism from the limit distance point to a machining start point within a detection range of the distance sensor, and the machining start point move command includes a position change to make the unit vector at the limit distance point coincide with a machining vector at the machining start point. [5] The laser machining apparatus according to claim 4, wherein the machining start point movement command further includes a distance correction for changing the machining start point in a direction along the machining vector based on the detection value from the distance sensor. [6] The laser processing apparatus according to claim 4 or 5, wherein the operation for generating the command by the movement command generating unit and the operation for moving the laser emission mechanism by the main control unit are executed in parallel at the same time. [7] A method for controlling the movement of a machining start point for a laser emission mechanism, which moves the laser emission mechanism of a laser machining apparatus having the laser emission mechanism for emitting a machining laser beam in a direction along a unit vector and a distance sensor provided in the laser emission mechanism, to a machining start point of a tracking machining controller, comprising an approach program for moving the laser emission mechanism from a control start position toward a laser irradiation point on a workpiece to a limit distance point at which the distance sensor starts detection; and a machining start point movement program for moving the laser emission mechanism from the limit distance point to a machining start point within a detection range of the distance sensor, wherein the machining start point movement program includes a position changing step for making the unit vector at the limit distance point coincide with a machining vector at the machining start point. [8] A method for controlling the movement of a machining start point for a laser emission mechanism according to claim 7, wherein the machining start point movement program further comprises a distance correcting step of changing the machining start point in a direction along the machining vector based on the detection value from the distance sensor. [9] A method for controlling the movement of a machining start point for a laser emission mechanism according to claim 7 or 8, wherein, in the machining start point movement command, an operation for generating a movement command for the laser emission mechanism and an actual operation for issuing the command are carried out in parallel at the same time.

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