JP7333203B2 - Laser processing machine and laser processing method - Google Patents

Description

The present invention relates to a laser processing machine that performs laser processing on a plate-shaped work (sheet metal), and a laser processing method for performing laser processing on the work.

A laser processing machine includes a laser processing head that irradiates a laser beam toward a work supported on a processing table. The laser processing head is movable relative to the processing table in X-axis and Y-axis directions, which are horizontal directions orthogonal to each other, and Z-axis direction, which is a vertical direction. The laser processing head has a nozzle for irradiating laser light on its tip side. Normally, the irradiation angle (incidence angle) of the laser beam with respect to the workpiece surface is set at 90 degrees, in other words, the irradiation angle of the laser beam with respect to the Z-axis direction is set at 0 degrees.

A Z-axis motor is provided at an appropriate position on the laser processing head as a nozzle movement actuator for moving the nozzle integrally with the laser processing head in the Z-axis direction, which is the direction in which the nozzle approaches and separates from the work surface. The Z-axis motor has an encoder as a position sensor that detects the position of the nozzle in the Z-axis direction. A gap sensor for detecting the gap between the nozzle and the work (the distance between the tip of the nozzle and the surface of the work) is provided at an appropriate position of the laser processing head. The nozzle motor or Z-axis motor is controlled based on the detection result from the gap sensor so as to keep the gap between the nozzle and the workpiece constant. As a result, stable laser processing can be performed on the work under processing conditions according to the thickness (plate thickness) of the work (Patent Document 1).

JP 2017-131897 A

By the way, if the workpiece is warped, although the actual thickness of the workpiece does not change, the apparent thickness, which is the length of the workpiece in the vertical direction, changes. For example, if the actual thickness of the work is 16 mm and the warp angle of the work is 15 degrees with respect to the XY axis plane, the apparent thickness of the work is 16.06 mm. Therefore, if laser processing is performed on the warped portion of the workpiece under processing conditions that correspond to the actual thickness of the workpiece, local cutting defects (processing There is a problem that a defect) is likely to occur.

Therefore, in order to solve the above-described problems, the present invention provides a laser processing machine capable of maintaining a constant irradiation angle (for example, 90 degrees) of a laser beam with respect to a workpiece surface even when the workpiece is warped. and to provide a laser processing method.

A laser processing machine according to a first embodiment of the present invention is relatively movable with respect to a processing table, has a nozzle on the tip side, and moves toward a plate-like work supported by the processing table. A laser processing head that irradiates a laser beam, an irradiation direction adjustment unit that adjusts an irradiation direction of the laser beam irradiated from the laser processing head, and a movement that detects a relative movement amount of the laser processing head with respect to the processing table. an amount sensor, a position sensor for detecting the position of the nozzle in the direction of approaching and separating from the work surface, and based on the detection result from the movement amount sensor and the detection result from the position sensor, always or in a minute time According to the obtained warp angle of the work, the irradiation angle of the laser beam with respect to the surface of the work during laser processing is determined while a gap sensor keeps the gap between the tip of the nozzle and the surface of the work constant . and an irradiation direction control unit that controls the irradiation direction adjustment unit so that the irradiation direction is constant.

A laser processing machine according to a first aspect of the present invention includes a warp angle acquisition unit that acquires a warp angle of the workpiece based on a detection result from the movement amount sensor and a detection result from the position sensor, The irradiation direction control unit may tilt the irradiation direction of the laser light with respect to a reference irradiation direction by the same angle as the acquired warp angle of the workpiece during the laser processing .

A laser processing machine according to a first aspect of the present invention includes a nozzle movement actuator that moves the nozzle toward and away from the work surface; and a gap controller for controlling the nozzle movement actuator so as to keep the distance) constant. Moreover, the laser processing machine according to the first aspect of the present invention may include a warp determination unit that determines whether or not the workpiece is warped based on the detection result from the position sensor.

According to the first embodiment of the present invention, the laser processing head is moved relatively to the processing table while the gap between the nozzle and the work (the distance between the tip of the nozzle and the surface of the work) is kept constant. A laser beam is irradiated from the laser processing head toward the work while moving. Thereby, laser processing can be performed on the work.

During laser processing, the irradiation direction control unit adjusts the irradiation direction so that the irradiation angle of the laser beam with respect to the workpiece surface is constant based on the detection result from the movement amount sensor and the detection result from the position sensor. control the department. As a result, even when the workpiece is warped, the irradiation angle (incidence angle) of the laser beam with respect to the workpiece surface can be kept constant (for example, 90 degrees).

In the laser processing method according to the second embodiment of the present invention, the laser processing head is operated while maintaining a constant gap between the tip of the nozzle of the laser processing head and the surface of a plate-shaped work supported on a processing table. irradiating a laser beam from the laser processing head toward the workpiece while moving relative to the processing table;
Based on the amount of relative movement of the laser processing head with respect to the processing table and the amount of change in the position of the nozzle in the direction of approaching and separating from the surface of the work , the warp angle of the work is constantly or minutely adjusted. is obtained, and the irradiation direction of the laser beam emitted from the laser processing head is adjusted according to the acquired warpage angle of the workpiece so that the irradiation angle of the laser beam with respect to the surface of the workpiece is constant during laser processing ( change.

According to the second embodiment of the present invention, even when the workpiece is warped, the irradiation angle of the laser beam to the workpiece surface can be kept constant (for example, 90 degrees).

According to the present invention, even if the workpiece is warped, it is possible to suppress the occurrence of local cutting defects (processing defects) and improve the processing quality of laser processing.

FIG. 1 is a schematic diagram showing a laser processing machine according to a first embodiment of the present invention. FIG. 2 is a diagram showing a movement locus (state of movement) of the laser processing head of the laser processing machine according to the first embodiment of the present invention when the workpiece is warped. FIG. 3 is a control block diagram of the laser processing machine according to the first embodiment of the present invention. FIG. 4 is a schematic diagram showing a laser processing machine according to a second embodiment of the present invention. FIG. 5 is a diagram showing the locus of movement of the laser processing head of the laser processing machine according to the second embodiment of the present invention when the workpiece is warped. FIG. 6 is a control block diagram of the laser processing machine according to the second embodiment of the present invention.

A first embodiment and a second embodiment of the present invention will be described below with reference to FIGS. 1 to 6. FIG.

In the specification and claims of the present application, the term "provided" includes not only direct provision but also indirect provision via another member. Moreover, in the embodiment of the present invention, the definition is as follows. The “X-axis direction” is one horizontal direction, and is also referred to as the front-rear direction. The “Y-axis direction” is one of the horizontal directions and is a direction perpendicular to the X-axis direction, and is also referred to as the left-right direction. The “Z-axis direction” means the vertical direction (vertical direction), and is also called the vertical direction. "A-axis" means a rotation axis parallel to the Z-axis direction. "B-axis" is a rotation axis perpendicular to the Z-axis direction. The term "and/or" is intended to include either one or both of the two. In the drawings, "FF" indicates forward direction, "FR" indicates rearward direction, "L" indicates left direction, "R" indicates right direction, "U" indicates upward direction, and "D" indicates downward direction. there is

(First embodiment)
As shown in FIG. 1, a laser processing machine 10 according to the first embodiment of the present invention is a processing machine that performs laser processing (cutting) on a plate-shaped work (sheet metal) W. As shown in FIG. The laser processing machine 10 includes a processing table 12 that supports a work W, and the processing table 12 is provided on a bed (not shown) of the laser processing machine 10 . The processing table 12 has a plurality of support plates 14 (only one is shown) spaced apart in the X-axis direction. Each support plate 14 extends in the Y-axis direction, and a plurality of mountain-shaped protrusions 14a for supporting the work W in point contact are formed along the Y-axis direction on the upper portion of each support plate 14. there is

A movable frame 16 (only a portion of which is shown) as an X-axis carriage is provided on the bed so as to be movable in the X-axis direction. The bed is provided with an X-axis motor 18 as an X-axis movement actuator for moving the movable frame 16 in the X-axis direction. The X-axis motor 18 has an encoder 18a that detects the amount of movement of the movable frame 16 in the X-axis direction. A Y-axis carriage 20 is provided on the movable frame 16 so as to be movable in the Y-axis direction. The movable frame 16 is provided with a Y-axis motor 22 as a Y-axis movement actuator for moving the Y-axis carriage 20 in the Y-axis direction. The Y-axis motor 22 has an encoder 22a that detects the amount of movement of the Y-axis carriage 20 in the Y-axis direction.

A Z-axis carriage 24 is provided on the Y-axis carriage 20 so as to be movable in the Z-axis direction. A Z-axis motor 26 as a Z-axis movement actuator for moving the Z-axis carriage 24 in the Z-axis direction is provided at an appropriate position on the Y-axis carriage 20 . The Z-axis motor 26 has an encoder 26a that detects the movement amount (position) of the Z-axis carriage 24 in the Z-axis direction. A cylindrical rotor 28 is provided on the Z-axis carriage 24 so as to be rotatable about the A-axis. At an appropriate position on the Z-axis carriage 24, an A-axis motor 30 is provided as A-axis rotating means for rotating the rotor 28 about the A-axis. The A-axis motor 30 has an encoder 30a that detects the rotational position (rotational angle) of the rotor 28 about the A-axis.

A laser processing head 32 that irradiates a laser beam LB toward the work W supported on the processing table 12 is provided on the rotating body 28 so as to be rotatable around the B axis. The laser processing head 32 has a nozzle 34 for irradiating the laser beam LB on its tip side, and the nozzle 34 is configured to be movable in its axial direction. A B-axis motor 36 as B-axis rotating means for rotating the laser processing head 32 around the B-axis is provided at an appropriate position on the Z-axis carriage 24 . The B-axis motor 36 has an encoder 36a that detects the rotational position (rotational angle) of the laser processing head 32 around the B-axis.

Here, the laser processing head 32 is driven by the X-axis motor 18 to move integrally with the movable frame 16 in the X-axis direction. The laser processing head 32 is driven by the Y-axis motor 22 to move integrally with the Y-axis carriage 20 in the Y-axis direction. The laser processing head 32 is driven by the Z-axis motor 26 to move together with the Z-axis carriage 24 in the Z-axis direction. The laser processing head 32 is driven by the A-axis motor 30 to rotate integrally with the rotor 28 around the A-axis. The encoders 18a and 22a correspond to movement amount sensors that detect the amount of movement of the laser processing head 32 in the horizontal direction (the X-axis direction, the Y-axis direction, or the combined direction of the X-axis direction and the Y-axis direction). The B-axis motor 36 corresponds to an irradiation direction adjusting section (irradiation direction changing section) that adjusts (changes) the irradiation direction of the laser beam LB emitted from the laser processing head 32 . The encoder 36a corresponds to an angle sensor that detects the angle of the optical axis of the laser beam LB with respect to the Z-axis direction.

At an appropriate position on the Z-axis carriage 24, there is a nozzle motor 38 as a nozzle moving actuator that moves the nozzle 34 with respect to the laser processing head 32 in a direction toward and away from the surface of the workpiece W (in the direction of the optical axis of the laser beam). is provided. The nozzle motor 38 has an encoder 38a as a position sensor for detecting the position of the nozzle 34 in the direction of approaching and separating from the surface of the workpiece W. As shown in FIG. The nozzle motor 38 may be omitted, and the entire laser processing head 32 may be moved toward and away from the surface of the workpiece W under the control of the X-axis motor 18, Y-axis motor 22, and Z-axis motor 26.

As shown in FIGS. 1 and 2, a capacitive gap sensor for detecting the gap between the nozzle 34 and the work W (the distance between the tip of the nozzle 34 and the surface of the work W) is provided at an appropriate position on the laser processing head 32. 40 are provided. Instead of the capacitive gap sensor 40, another gap sensor such as an eddy current gap sensor (not shown) may be used.

As shown in FIG. 1, the rotor 28 and the laser processing head 32 are optically connected via an optical fiber 42 to a laser oscillator (not shown) that oscillates the laser beam LB. A collimating lens 44 for collimating the laser beam LB emitted from the exit end of the optical fiber 42 is provided in the rotating body 28 . A first bend mirror 46 that bends and emits the collimated laser beam LB is provided on the exit side of the collimating lens 44 in the rotating body 28 . Further, a second bend mirror 48 is provided in the laser processing head 32 to bend and emit the laser beam LB emitted from the first bend mirror 46 . A converging lens 50 that converges the laser beam LB toward the work W is provided on the exit side of the second bend mirror 48 in the laser processing head 32 .

As shown in FIG. 3, the laser processing machine 10 operates an X-axis motor 18, a Y-axis motor 22, a Z-axis motor 26, an A-axis motor 30, a B-axis motor, a nozzle motor 38, etc. based on a processing program or the like. It has a control device 52 for controlling. The control device 52 is composed of one or more computers, and is connected to the plurality of encoders 18a, 22a, 26a, 30a, 36a, 38a and the gap sensor 40. FIG. The control device 52 has a memory (not shown) that stores machining programs and the like, and a CPU (not shown) that executes the machining programs.

By executing the machining program, the CPU of the control device 52 functions as the gap control section 54, the warp determination section 56, the warp angle acquisition section 58, and the irradiation direction control section 60. have. The contents of the gap control unit 54, the warp determination unit 56, the warp angle acquisition unit 58, and the irradiation direction control unit 60 are as follows.

As shown in FIGS. 2 and 3, the gap controller 54 controls the nozzle motor 38 to keep the gap between the nozzle 34 and the workpiece W constant during laser machining while monitoring the detection result from the gap sensor 40. Control.

The warp determination unit 56 determines whether or not the workpiece W is warped based on the detection result from the encoder 38a as a position sensor. Specifically, when warping occurs in the work W, the nozzle 34 rises so as to maintain a constant gap with the work W, and the encoder 38a detects the position of the raised nozzle 34 in the direction of approaching and separating from the surface of the work W. to detect Then, the warp determination unit 56 determines that the amount of change in the position of the nozzle 34 in the direction of approaching and separating from the surface of the workpiece W (the amount of change in the nozzle position) with respect to the amount of movement of the laser processing head 32 in the horizontal direction by a predetermined distance is It is determined whether or not the determination threshold value for determining the presence or absence of warpage of the workpiece W is exceeded. The warp determination unit 56 determines that the workpiece W does not warp when the amount of change in the nozzle position does not exceed the determination threshold value. The warpage determination unit 56 determines that the workpiece W warps when the amount of change in the nozzle position exceeds the determination threshold value.

When it is determined that the workpiece W is warped, the warp angle acquisition unit 58 determines the workpiece W based on the detection results from the encoders 18a and 22a as movement amount sensors and the detection result from the encoder 38a as the position sensor. A warp angle θ is obtained by calculation. Specifically, the warp angle acquisition unit 58 acquires the warp angle θ of the workpiece W by calculation based on the following relational expression (1).
θ=tan ⁻¹ (ΔH/ΔL) Relational expression (1)
Here, ΔH in the relational expression (1) is the absolute value of the amount of change in the position of the nozzle 34 in the direction in which the nozzle 34 approaches and separates from the surface of the workpiece W by the nozzle motor 38 in the set minute time. ΔL in the relational expression (1) is the amount of change in the amount of horizontal movement (the sum of the X-axis component and the Y-axis component) of the laser processing head 32 by the X-axis motor 18 and the Y-axis motor 22 in the set minute time. is the absolute value of

The irradiation direction control unit 60 tilts the irradiation direction of the laser beam LB emitted from the laser processing head 32 with respect to the Z-axis direction, which is the reference irradiation direction, by the same angle as the obtained warp angle θ of the workpiece W. As shown in FIG. 2, the B-axis motor 36 is controlled while monitoring the detection result from the encoder 36a (see the two-dot chain line and the solid line in FIG. 2). Here, when the height of the nozzle 34 (the position in the approaching/separating direction) increases due to the horizontal movement of the laser processing head 32, the irradiation direction of the laser beam LB is directed toward the moving direction of the laser processing head 32. The B-axis motor 36 is controlled so that the work W is tilted with respect to the Z-axis direction by the same angle as the warp angle θ. When the height of the nozzle 34 is lowered due to the horizontal movement of the laser processing head 32, the irradiation direction of the laser beam LB is set to the opposite side of the movement direction of the laser processing head 32 to the same warp angle θ of the workpiece W. The B-axis motor 36 is controlled so as to tilt with respect to the Z-axis direction by an angle. Further, the irradiation direction control unit 60 controls the A-axis motor 30 while monitoring the detection result from the encoder 30a so that the B-axis is orthogonal to the moving direction of the laser processing head 32. FIG.

After the B-axis motor 36 is controlled as described above, the warp angle acquisition unit 58 acquires the warp angle θ of the work W by calculation based on the following relational expression (2).
θ≈sin ⁻¹ (ΔH/ΔL) Relational expression (2)
Here, ΔH in relational expression (2) is the same as ΔH in relational expression (1). ΔL in relational expression (2) is the same as ΔL in relational expression (1). Note that the warp angle obtaining unit 58 may obtain the warp angle θ of the workpiece W by calculation based on the relational expression (1) even after the B-axis motor 36 is controlled as described above.

After controlling the B-axis motor 36 as described above, the irradiation direction control unit 60 does not tilt the irradiation direction of the laser beam LB with respect to the Z-axis direction when the amount of change in the nozzle position is below the determination threshold. The B-axis motor 36 is controlled as follows.

Next, the effects of the first embodiment of the present invention, including the laser processing method according to the first embodiment of the present invention, will be described. A laser processing method according to the first embodiment of the present invention is a method for performing laser processing (cutting) on a workpiece W, and includes an irradiation step, a warp determination step, a warp angle acquisition step, and an irradiation direction. and an adjustment step (irradiation direction change step).

The control device 52 controls the X-axis motor 18 and/or the Y-axis motor 22 to move the laser processing head 32 in the horizontal direction (X-axis direction, Y-axis direction, or combined direction of the X-axis direction and the Y-axis direction). Meanwhile, the laser beam LB is irradiated from the laser processing head 32 toward the work W (irradiation step). Further, the gap control unit 54 controls the nozzle motor 38 so as to keep the gap between the nozzle 34 and the workpiece W constant while monitoring the detection result from the gap sensor 40 . Further, the irradiation direction control unit 60 controls the A-axis motor 30 so that the B-axis is orthogonal to the moving direction of the laser processing head 32 . Thereby, the workpiece W can be laser-machined under the machining conditions corresponding to the actual thickness of the workpiece W.

During laser processing, the warp determination unit 56 determines whether or not the workpiece W is warped based on the detection result from the encoder 38a as a position sensor (warp determination step). Then, when it is determined that the workpiece W is warped, the warp angle acquisition unit 58 determines the workpiece based on the detection results from the encoders 18a and 22a as movement amount sensors and the detection result from the encoder 38a as the position sensor. A warp angle θ of W is obtained by calculation (warp angle obtaining step). Furthermore, the irradiation direction control unit 60 controls the B-axis motor 36 so that the irradiation direction of the laser beam LB is inclined with respect to the Z-axis direction by the same angle as the warp angle θ of the workpiece W (irradiation direction adjustment step). As a result, the surface of the work W can be irradiated perpendicularly with the laser beam LB even when the work is warped. In other words, the irradiation angle of the laser beam to the surface of the workpiece W can be kept constant (90 degrees in the first embodiment of the present invention) during laser processing.

Alternatively, the warp determination unit 56 may be omitted, and the warp angle acquisition unit 58 may acquire the warp angle θ of the work W by constant calculation based on the detection results from the encoders 18a, 22a, and 38a.

Therefore, according to the first embodiment of the present invention, even if the workpiece W is warped, it is possible to suppress the occurrence of local cutting defects (processing defects) and improve the processing quality of laser processing. .

(Second embodiment)
As shown in FIG. 4, a laser processing machine 62 according to the second embodiment of the present invention is a processing machine that performs laser processing on a plate-shaped work W, and is the laser processing machine according to the first embodiment of the present invention. It has the same configuration as the machine 10 (see FIG. 1). Then, of the configuration of the laser processing machine 62, the configuration different from that of the laser processing machine 10 will be briefly described. Among the plurality of components of the laser processing machine 62, those corresponding to the components of the laser processing machine 10 are denoted by the same reference numerals in the drawing.

The Y-axis carriage 20 is provided with a laser processing head 64 that irradiates a laser beam LB toward the work W supported on the processing table 12 so as to be movable in the Z-axis direction. The laser processing head 64 has a nozzle 66 for irradiating the laser beam LB on its tip side, and the axial direction of the nozzle 66 is the Z-axis direction. A Z-axis motor 68 is provided at an appropriate position on the Y-axis carriage 20 as a Z-axis movement actuator for moving the laser processing head 64 in the Z-axis direction. The Z-axis motor 68 has an encoder 68a that detects the position (movement amount) of the laser processing head 64 in the Z-axis direction.

Here, the laser processing head 64 is moved integrally with the movable frame 16 in the X-axis direction by driving the X-axis motor 18 . The laser processing head 64 is driven by the Y-axis motor 22 to move integrally with the Y-axis carriage 20 in the Y-axis direction. Also, the Z-axis motor 68 corresponds to a nozzle movement actuator that moves the nozzle 66 in the Z-axis direction, which is the direction in which the nozzle 66 approaches and separates from the surface of the workpiece W. The encoders 18a and 22a correspond to movement amount sensors that detect the amount of movement of the laser processing head 64 in the horizontal direction (X-axis direction, Y-axis direction, combined direction of the X-axis direction and the Y-axis direction). The encoder 68a corresponds to a position sensor that detects the position of the nozzle 66 in the Z-axis direction.

As shown in FIGS. 4 and 5, a capacitive gap sensor 70 for detecting the gap between the nozzle 66 and the workpiece W is provided at an appropriate position on the laser processing head 64 . Instead of the capacitive gap sensor 70, another gap sensor such as an eddy current gap sensor (not shown) may be used.

As shown in FIG. 4, the laser processing head 64 is optically connected via an optical fiber 72 to a laser oscillator (not shown) that oscillates the laser beam LB. A collimator lens 74 for collimating the laser beam LB emitted from the exit end of the optical fiber 72 is provided in the laser processing head 64 . A galvanometer scanner 76 that two-dimensionally scans the collimated laser beam LB is provided on the exit side of the collimator lens 74 in the laser processing head 64 . The galvanometer scanner 76 includes a first galvanometer mirror 78 rotatably provided around an axis that intersects the exit side of the collimator lens 74 in the vertical direction, and a first rotation driving means for rotating the first galvanometer mirror 78 . 1 galvano motor 80 is provided. The first galvanometer motor 80 has an encoder 80 a as a first rotation angle sensor that detects the rotation angle of the first galvanometer mirror 78 . The galvanometer scanner 76 includes a second galvanometer mirror 82 provided rotatably about a horizontal axis on the exit side of the first galvanometer mirror 78 , and a second galvanometer mirror 82 as a second rotation driving means for rotating the second galvanometer mirror 82 . A galvano motor 84 is provided. The second galvanometer motor 84 has an encoder 84 a as a second rotation angle sensor that detects the rotation angle of the second galvanometer mirror 82 .

Here, by varying (adjusting) the rotation angle of the first galvanometer mirror 78 and the rotation angle of the second galvanometer mirror 82, the irradiation direction of the laser beam LB emitted from the laser processing head 64 can be adjusted (changed). can be done. In other words, the galvanometer scanner 76 corresponds to an irradiation direction adjusting section (irradiation direction changing section) that adjusts (changes) the irradiation direction of the laser beam LB.

A bend mirror 86 that bends and emits the two-dimensionally scanned laser beam LB is provided on the exit side of the second galvanomirror 82 in the laser processing head 64 . A converging lens (F.theta.

As shown in FIG. 6, the laser processing machine 62 controls the X-axis motor 18, the Y-axis motor 22, the Z-axis motor 26, the first galvano motor 80, the second galvano motor 84, etc. based on a processing program or the like. It has a control device 90 for The control device 90 is composed of one or more computers, and is connected to the plurality of encoders 18a, 22a, 26a, 76a, 80a and the gap sensor 70. FIG. The control device 90 has a memory (not shown) that stores machining programs and the like, and a CPU (not shown) that executes the machining programs.

By executing the machining program, the CPU of the control device 90 functions as the gap control section 92, the warp determination section 94, the warp angle acquisition section 96, and the irradiation direction control section 98. have. The contents of the gap control unit 92, the warp determination unit 94, the warp angle acquisition unit 96, and the irradiation direction control unit 98 are as follows.

As shown in FIGS. 5 and 6, the gap controller 92 controls the Z-axis motor 26 to keep the gap between the nozzle 66 and the workpiece W constant during laser machining while monitoring the detection result from the gap sensor 70 . to control.

The warpage determination unit 94 determines whether or not the workpiece W is warped based on the detection result from the encoder 68a as a position sensor. Specifically, when warping occurs in the work W, the nozzle 66 rises so as to maintain a constant gap with the work W, and the encoder 68a detects the position of the lifted nozzle 66 in the Z-axis direction. The warp determination unit 94 determines the amount of change in the position of the nozzle 66 in the direction of approaching and separating from the surface of the work W (the amount of change in the nozzle position) with respect to the amount of movement of the laser processing head 64 in the horizontal direction by a predetermined distance. It is determined whether or not a determination threshold value for determining the presence or absence of warpage has been exceeded. The warp determination unit 94 determines that the workpiece W does not warp when the amount of change in the nozzle position does not exceed the determination threshold value. The warpage determination unit 94 determines that the workpiece W warps when the amount of change in the nozzle position exceeds the determination threshold value.

When it is determined that the workpiece W is warped, the warp angle acquiring unit 96 determines the workpiece W based on the detection results from the encoders 18a and 22a as movement amount sensors and the detection result from the encoder 68a as the position sensor. A warp angle θ is obtained by calculation. Specifically, the warp angle acquisition unit 96 acquires the warp angle θ of the work W by calculation based on the following relational expression (3).
θ=tan ⁻¹ (ΔH/ΔL) Relational expression (3)
Here, ΔH in relational expression (3) is the absolute value of the amount of change in the position of the nozzle 66 in the Z-axis direction caused by the Z-axis motor 68 in the set minute time. ΔL in the relational expression (3) is the absolute value of the amount of change in the amount of horizontal movement of the laser processing head 64 by the X-axis motor 18 and the Y-axis motor 22 in the set minute time.

The irradiation direction control unit 98 tilts the irradiation direction of the laser beam LB emitted from the laser processing head 64 by the same angle as the obtained warp angle θ of the workpiece W with respect to the Z-axis direction, which is the reference irradiation direction. , the first galvanometer motor 80 and the second galvanometer motor 84 are controlled while monitoring the detection results from the encoders 80a, 80a (see the two-dot chain line and the solid line in FIG. 5). Here, when the height of the nozzle 66 (the position in the Z-axis direction) increases due to the horizontal movement of the laser processing head 64, the irradiation direction of the laser beam LB is directed toward the moving direction of the laser processing head 64. The first galvano motor 80 and the second galvano motor 84 are controlled so as to incline the W by the same angle as the warp angle θ with respect to the Z-axis direction. When the height of the nozzle 66 is lowered due to the horizontal movement of the laser processing head 64, the irradiation direction of the laser beam LB is set to the opposite side of the moving direction of the laser processing head 64 to the same warp angle θ of the workpiece W. The first galvano-motor 80 and the second galvano-motor 84 are controlled so as to incline by an angle with respect to the Z-axis direction.

After controlling the first galvanometer motor 80 and the second galvanometer motor 84 as described above, the irradiation direction control unit 98 changes the irradiation direction of the laser beam LB to Z The first galvanomotor 80 and the second galvanomotor 84 are controlled so as not to tilt with respect to the axial direction.

Next, the effects of the second embodiment of the present invention, including the laser processing method according to the second embodiment of the present invention, will be described. A laser processing method according to the second embodiment of the present invention is a method for performing laser processing on a workpiece W, and includes an irradiation step, a warp determination step, a warp angle acquisition step, and an irradiation direction adjustment step (irradiation direction change step).

The controller 90 controls the X-axis motor 18 and/or the Y-axis motor 22 to move the laser processing head 64 in the horizontal direction (X-axis direction, Y-axis direction, or combined direction of the X-axis direction and the Y-axis direction). while the laser processing head 64 irradiates the workpiece W with the laser beam LB (irradiation step). Further, the gap control unit 92 controls the Z-axis motor 68 so as to keep the gap between the nozzle 66 and the workpiece W constant while monitoring the detection result from the gap sensor 70 . Thereby, the workpiece W can be laser-machined under the machining conditions corresponding to the actual thickness of the workpiece W.

During laser processing, the warp determination unit 94 determines whether or not the workpiece W is warped based on the detection result from the encoder 68a as a position sensor (warp determination step). Then, when it is determined that the workpiece W is warped, the warp angle acquiring unit 96 determines the workpiece based on the detection results from the encoders 18a and 22a as movement amount sensors and the detection result from the encoder 68a as the position sensor. A warp angle θ of W is obtained by calculation (warp angle obtaining step). Furthermore, the irradiation direction control unit 98 controls the first galvano motor 80 and the second galvano motor 84 so that the irradiation direction of the laser beam LB is inclined with respect to the Z-axis direction by the same angle as the warp angle θ of the workpiece W. (irradiation direction adjustment step). As a result, the surface of the work W can be irradiated perpendicularly with the laser beam LB even when the work is warped. In other words, the irradiation angle of the laser beam to the surface of the workpiece W can be kept constant (90 degrees in the second embodiment of the present invention) during laser processing.

Note that the warp determination unit 94 may be omitted, and the warp angle acquisition unit 96 may acquire the warp angle θ of the work W by constant calculation based on the detection results from the encoders 18a, 22a, and 68a.

Therefore, also in the second embodiment of the present invention, the same effects as those of the above-described first embodiment of the present invention can be obtained.

The present invention is not limited to the description of the above-described embodiments, and can be implemented in the following aspects, for example.

Instead of configuring the laser processing head 32 (64) to be movable in the X-axis direction and the Y-axis direction, it may be configured to be movable in one of the X-axis direction and the Y-axis direction. In this case, the processing table 12 is configured to be movable in the other of the X-axis direction and the Y-axis direction. Also, the laser processing head 32 (64) may be configured to be immovable in the X-axis direction or the Y-axis direction. In this case, the processing table 12 is configured to be movable in the X-axis direction and the Y-axis direction. In other words, it is sufficient that the laser processing head 32 (64) can be moved relative to the processing table 12 in the X-axis direction and the Y-axis direction.

And the scope of rights included in the present invention is not limited to the above-described embodiments.

REFERENCE SIGNS LIST 10 laser processing machine 12 processing table 14 support plate 14a projection 16 movable frame (X-axis carriage)
18 X-axis motor 18a Encoder (movement amount sensor)
20 Y-axis carriage 22 Y-axis motor 22a Encoder (movement amount sensor)
24 Z-axis carriage 26 Z-axis motor 26a Encoder 28 Rotator 30 A-axis motor 30a Encoder 32 Laser processing head 34 Nozzle 36 B-axis motor (irradiation direction adjustment unit)
36a encoder 38 nozzle motor (nozzle movement actuator)
38a encoder (position sensor)
40 gap sensor 42 optical fiber 44 collimator lens 46 first bend mirror 48 second bend mirror 50 focusing lens 52 control device 54 gap control unit 56 warp determination unit 58 warp angle acquisition unit 60 irradiation direction control unit 62 laser processing machine 64 laser processing Head 66 Nozzle 68 Z-axis motor (nozzle movement actuator)
68a encoder (position sensor)
70 gap sensor 72 optical fiber 74 collimating lens 76 galvanometer scanner 78 first galvanometer mirror 80 first galvanometer motor (irradiation direction adjusting unit)
80a encoder 82 second galvano mirror 84 second galvano motor (irradiation direction adjusting unit)
84a Encoder 86 Bend Mirror 88 Focusing Lens 90 Control Device 92 Gap Control Section 94 Warp Determination Section 96 Warp Angle Acquisition Section 98 Irradiation Direction Control Section W Work (sheet metal)
θ Warp angle

Claims (5)

a laser processing head that is movable relative to the processing table, has a nozzle on the tip side, and irradiates a laser beam toward a plate-shaped work supported by the processing table;
an irradiation direction adjustment unit that adjusts the irradiation direction of the laser beam emitted from the laser processing head;
a movement amount sensor that detects the amount of movement of the laser processing head relative to the processing table;
a position sensor for detecting the position of the nozzle in the direction of approaching and separating from the work surface;
Based on the detection result from the movement amount sensor and the detection result from the position sensor, the gap sensor detects the difference between the tip of the nozzle and the surface of the work according to the warp angle of the work that is acquired constantly or in a minute time. an irradiation direction control unit that controls the irradiation direction adjustment unit so that the irradiation angle of the laser beam with respect to the surface of the workpiece during laser processing is constant while the gap is kept constant ;
A laser processing machine comprising: A warp angle acquisition unit that acquires the warp angle of the workpiece based on the detection result from the movement amount sensor and the detection result from the position sensor,
2. The irradiation direction control unit tilts the irradiation direction of the laser beam with respect to a reference irradiation direction by the same angle as the acquired warp angle of the workpiece during the laser processing. The described laser processing machine. a nozzle movement actuator that moves the nozzle in a direction toward or away from the surface of the workpiece ;
a gap control unit that controls the nozzle movement actuator so as to keep a constant gap between the tip of the nozzle and the surface of the workpiece ;
The laser processing machine according to claim 1 or 2, characterized by comprising: 4. The laser processing according to any one of claims 1 to 3, further comprising a warp determination unit that determines whether or not the workpiece is warped based on a detection result from the position sensor. machine. While maintaining a constant gap between the tip of the nozzle of the laser processing head and the surface of the plate-shaped work supported on the processing table, while moving the laser processing head relatively to the processing table, irradiating a laser beam from a laser processing head toward the work,
Based on the amount of relative movement of the laser processing head with respect to the processing table and the amount of change in the position of the nozzle in the direction of approaching and separating from the surface of the work , the warp angle of the work is constantly or minutely adjusted. and adjusting the irradiation direction of the laser beam emitted from the laser processing head according to the obtained warpage angle of the workpiece so that the irradiation angle of the laser beam with respect to the surface of the workpiece is constant during laser processing. A laser processing method characterized by:

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