Laser processing device and laser processing method

Abstract

The control unit of the laser processing device includes a tilt angle calculation unit, a gap correction amount calculation unit, a processing condition correction amount calculation unit, a processing condition correction unit, and an apparatus control unit. The tilt angle calculation unit calculates the tilt angle between the nozzle opening face, which is the workpiece-side face of the processing nozzle, and the surface of the workpiece at the laser processing position of the workpiece. The gap correction amount calculation unit calculates a gap correction amount for correcting a set gap amount between the nozzle opening face and the surface of the workpiece using the tilt angle and shape data of the processing nozzle. The processing condition correction amount calculation unit calculates a correction amount for the laser processing conditions corresponding to the gap correction amount using processing condition adjustment information indicating the relationship between the change in gap amount and the correction amount for the laser processing conditions. The processing condition correction unit corrects the laser processing conditions using the correction amount for the laser processing conditions. The apparatus control unit controls the axis movement control unit so that the corrected gap amount is the sum of the set gap amount and the gap correction amount.

Description

[Technical Field]

[0001] The present disclosure relates to a laser processing apparatus and a laser processing method for processing a workpiece by irradiating it with laser light. [Background technology]

[0002] A laser processing device processes a workpiece by irradiating the workpiece with a laser beam emitted from a laser oscillator while supplying an assist gas. The workpiece is processed by removing the melted area caused by the laser beam with the assist gas. It is desirable for this laser processing device to perform stable, high-quality processing.

[0003] In laser processing machines, it is necessary to optimally set the focal position of the energy irradiation, such as laser light, depending on the thickness of the workpiece to be cut, and to prevent the processing nozzle from coming into contact with the workpiece, which may be distorted during cutting. For this reason, laser processing machines employ tracking control to maintain a constant distance between the tip of the processing nozzle and the surface of the workpiece. Furthermore, when the workpiece is a relatively thick steel plate, welding is often performed after cutting, and a groove may be formed when the steel plate is cut. To adapt the laser processing machine to such cutting situations, i.e., to enable groove processing that creates a slope on the cut surface of the workpiece, the laser processing machine can tilt the processing nozzle from a vertical position relative to the workpiece.

[0004] In addition, laser processing equipment can also perform hole drilling. In one example, a vent hole is formed in a cylindrical workpiece by drilling. Drilling can be performed in two ways: straight hole drilling, which drills a hole perpendicular to the surface of the workpiece, and oblique hole drilling, which drills a hole oblique to the surface of the workpiece. When a single workpiece undergoes both straight hole drilling and oblique hole drilling, the position of the processing nozzle is controlled to tilt the laser beam while keeping the focal position constant. In this case, contact between the processing nozzle and the workpiece can potentially damage the laser processing equipment or the workpiece.

[0005] Patent Document 1 discloses a laser processing device that prevents contact between the processing nozzle and the workpiece. Specifically, the laser processing device described in Patent Document 1 calculates a reference distance between the processing nozzle and the workpiece based on the tip radius of the processing nozzle of the laser processing device, the clearance between the processing nozzle and the surface of the workpiece, and the inclination angle between the processing nozzle and the workpiece. The laser processing device described in Patent Document 1 then adjusts the distance between the processing nozzle and the workpiece so that it does not become smaller than the reference distance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-081434 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the technology described in Patent Document 1 may result in a decrease in laser processing quality. For example, changing the position of the processing nozzle to avoid contact can result in a decrease in laser processing quality because the focal position of the laser light is shifted from the surface of the workpiece. It is also possible to prevent a decrease in laser processing quality by switching to a processing nozzle with a different shape depending on the processing shape of the workpiece and applying sufficient pressure to the melted area caused by the laser light. However, the technology described in Patent Document 1 also has the problem of being unable to control multiple processing nozzle shapes.

[0008] The present disclosure has been made in consideration of the above, and aims to provide a laser processing device that is capable of changing the angle between the surface of the workpiece and the nozzle opening surface of the processing nozzle, and that can suppress deterioration in laser processing quality compared to conventional devices while avoiding contact between the processing nozzle and the workpiece. [Means for solving the problem]

[0009] To solve the above-mentioned problems and achieve the object, the laser processing apparatus of the present disclosure includes a laser oscillator, a table, a processing head, a processing nozzle, an axial movement control unit, and a control unit. The laser oscillator emits a laser beam. A workpiece is placed on the table. The processing head irradiates the workpiece with the laser beam from the laser oscillator. The processing nozzle is provided on the laser beam emission end of the processing head and sprays assist gas onto the position where the laser beam is irradiated onto the workpiece. The axial movement control unit drives the table or the processing head in the directions of the mutually orthogonal X-axis, Y-axis, and Z-axis, rotates the table or the processing head around a tilt axis in the XY plane formed by the X-axis and Y-axis, and rotates the table or the processing head around a rotation axis parallel to the Z-axis. The control unit controls the laser oscillator and the axial movement control unit. The control unit includes a tilt angle calculation unit, a gap correction amount calculation unit, a processing condition correction amount calculation unit, a processing condition correction unit, and an apparatus control unit. The tilt angle calculation unit calculates the tilt angle between the nozzle opening face, which is the face of the processing nozzle facing the workpiece, and the surface of the workpiece at the laser processing position of the workpiece. The gap correction amount calculation unit calculates a gap correction amount for correcting a set gap amount between the nozzle opening face and the surface of the workpiece using the tilt angle and shape data of the processing nozzle. The processing condition correction amount calculation unit calculates a correction amount for the laser processing conditions corresponding to the gap correction amount using processing condition adjustment information indicating the relationship between the change in gap amount and the correction amount for the laser processing conditions. The processing condition correction unit corrects the laser processing conditions using the correction amount for the laser processing conditions. The device control unit controls the axis movement control unit so that the corrected gap amount is the sum of the set gap amount and the gap correction amount. [Effects of the Invention]

[0010] The laser processing device of the present disclosure is a laser processing device that is capable of changing the angle between the surface of the workpiece and the nozzle opening surface of the processing nozzle, and has the effect of being able to suppress deterioration in laser processing quality compared to conventional devices while avoiding contact between the processing nozzle and the workpiece. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a laser processing device. [Figure 2] FIG. 2 is a perspective view showing an example of the configuration of a drive shaft of the laser processing device shown in FIG. [Figure 3] FIG. 2 is a side view showing an example of the configuration of the shaft of the laser processing device shown in FIG. [Figure 4] Flowchart showing an example of a procedure for a laser processing method [Figure 5] Flowchart showing an example of a procedure for a laser processing method [Figure 6] FIG. 1 is a diagram for explaining an example of contact avoidance and occurrence of processing defects by a conventional laser processing device. [Figure 7] FIG. 10 is a diagram showing an outline of a procedure for calculating a gap correction amount and a procedure for correcting a nozzle position in a vertical processing nozzle used in the laser processing device according to the first embodiment. [Figure 8] FIG. 10 is a diagram for explaining an example of a procedure for correcting laser processing conditions in a vertical processing nozzle used in the laser processing apparatus according to the first embodiment. [Figure 9] FIG. 1 is a block diagram showing an example of the configuration of a processing program generation unit of a laser processing device according to a first embodiment. [Figure 10] FIG. 10 is a diagram showing an example of a relationship between input data and output data of a machining program generation unit; [Figure 11] 1 is a flowchart showing an example of a processing procedure of a laser processing method according to a first embodiment. [Figure 12] 1 is a flowchart showing an example of a processing procedure of a laser processing method according to a first embodiment. [Figure 13] FIG. 10 is a diagram showing an example of the configuration of a tilt processing nozzle used in a laser processing device according to a second embodiment. [Figure 14] FIG. 10 is a diagram showing an outline of a procedure for calculating a gap correction amount and a procedure for correcting a nozzle position in an inclined processing nozzle used in a laser processing device according to a second embodiment. [Figure 15] FIG. 10 is a diagram for explaining an example of a procedure for correcting laser processing conditions in an inclined processing nozzle used in the laser processing device according to the second embodiment. [Figure 16] FIG. 10 is a diagram showing an example of laser processing conditions during laser processing using a vertical processing nozzle and an inclined processing nozzle used in the laser processing device according to the third embodiment. [Figure 17] FIG. 1 is a block diagram showing an example of the configuration of a computer system that realizes a control device for a laser processing device according to first to third embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A laser processing apparatus and a laser processing method according to embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0013] First, the configuration of a general laser processing device and a laser processing method will be described. Next, problems that arise when laser processing is performed when the surface of the workpiece and the nozzle opening surface are not parallel will be described, taking as examples straight hole processing and inclined hole processing. After that, an embodiment that can solve these problems will be described.

[0014] 1 is a diagram showing an example of the configuration of a laser processing apparatus 10. The laser processing apparatus 10 is an apparatus for laser processing a workpiece W, which is an object to be processed, by irradiating the workpiece W with laser light L, which is a laser beam.

[0015] The laser processing apparatus 10 includes a table 11, a laser oscillator 12, a fiber cable 13, a processing head 14, a processing nozzle 15, a processing gas supply unit 16, a gas pipe 17, an axial movement control unit 18, and a control device 30.

[0016] The table 11 places the workpiece W on it. The table 11 may have a function of fixing the workpiece W. The shape of the workpiece W may be a flat plate, a cylindrical shape, or any other three-dimensional shape.

[0017] The laser oscillator 12 emits laser light L. As an example of the type of laser oscillator 12 that generates the laser light L that the laser processing apparatus 10 irradiates onto the workpiece W, a fiber laser using a semiconductor laser or a CO2 laser is used. Furthermore, an example of the wavelength of the laser light L emitted from the laser oscillator 12 is 1070 nm for a fiber laser. The laser light L may be a continuous wave or a pulse wave.

[0018] The fiber cable 13 transmits the laser light L emitted from the laser oscillator 12 to the processing head 14.

[0019] The processing head 14 irradiates the workpiece W with laser light L from the laser oscillator 12 that has propagated through the fiber cable 13. Although not shown, the processing head 14 has inside it a collimating optical system that collimates the laser light L and a condenser lens that focuses the laser light L. The position where the laser light L from the processing head 14 is incident on the workpiece W is called the processing point P. The processing point P is the position on the workpiece W where processing is being performed.

[0020] The processing nozzle 15 is provided on the emission end side of the laser light L of the processing head 14, and sprays assist gas at the position where the laser light L is irradiated onto the workpiece W. In one example, the processing nozzle 15 has an injection port that injects assist gas so as to surround the periphery of the emission position of the laser light L of the processing head 14. In this example, a flow path 141 that guides assist gas to the processing nozzle 15 is provided inside the processing head 14. The assist gas is used to remove molten material during processing in an area including the processing point P of the workpiece W, to cool the workpiece W, and to suppress or oxidize the workpiece W. The type of assist gas is selected depending on the purpose of use.

[0021] The processing gas supply unit 16 supplies assist gas to the processing nozzle 15 via a gas pipe 17. In one example, the processing gas supply unit 16 is disposed outside the laser processing apparatus 10. The gas pipe 17 is connected between the processing gas supply unit 16 and the processing head 14 so that the assist gas from the processing gas supply unit 16 is sprayed from the processing nozzle 15.

[0022] The axis movement control unit 18 drives at least one of the machining head 14 and the table 11. In one example, the axis movement control unit 18 has a drive shaft (not shown) which is a machining shaft directly or indirectly connected to the machining head 14 and the table 11, and a motor (not shown) which drives the drive shaft. The drive shaft is connected to the motor and transmits force from the motor directly or indirectly to the machining head 14 or the table 11. The motor is a motor such as a servo motor.

[0023] FIG. 2 is a perspective view showing an example of the configuration of the drive axes of the laser processing apparatus shown in FIG. 2. In FIG. 2, the X-axis, Y-axis, and Z-axis are three axes perpendicular to each other. In one example, the X-axis and Y-axis are axes parallel to the horizontal direction. In one example, the Z-axis is an axis parallel to the vertical direction. The B-axis is an axis around which the workpiece W on the table 11 is rotated, which is parallel to the Y-axis. The B-axis is also referred to as the tilt axis. The C-axis is an axis around which the workpiece W on the table 11 is rotated, which is parallel to the Z-axis. The C-axis is also referred to as the rotation axis. Here, an example is shown in which the B-axis is provided, but instead of the B-axis, an A-axis may be provided, which is an axis around which the workpiece W on the table 11 is rotated, which is parallel to the X-axis. FIG. 2 shows an example in which the workpiece W is supported on the table 11 by a jig 111.

[0024] In the example of FIG. 2, the machining head 14 has three drive axes and the table 11 has two drive axes. That is, the machining head 14 has three drive axes (not shown) parallel to the X-axis, Y-axis, and Z-axis. Each drive axis is connected to a motor (not shown) and transmits the force from the motor directly or indirectly to the machining head 14. In addition, the table 11 has two drive axes (not shown) that serve as two rotation axes, the B-axis and the C-axis. Each drive axis is connected to a motor (not shown) and transmits the force from the motor directly or indirectly to the table 11. Note that, although FIG. 2 shows a configuration in which the machining head 14 has three drive axes and the table 11 has two drive axes, other configurations are also possible.

[0025] In this way, the axis movement control unit 18 drives the table 11 or the machining head 14 in the directions of the mutually perpendicular X-axis, Y-axis, and Z-axis, rotates the table 11 or the machining head 14 around the inclined axis in the XY plane formed by the X-axis and Y-axis, and rotates the table 11 or the machining head 14 around the Z-axis.

[0026] 1, the control device 30 is a device that controls the laser oscillator 12, the processing gas supply unit 16, and the axis movement control unit 18. The control device 30 has a processing program generation unit 31 and an equipment control unit 33. The control device 30 corresponds to the control unit.

[0027] The machining program generation unit 31 generates a machining program including a machining path for performing laser machining based on workpiece shape data indicating the shape of the workpiece W and machining information including the position, diameter, and angle of a hole to be formed in the workpiece W. The machining program is a computer program that irradiates the workpiece W with laser light L to machine the workpiece W. In one example, the machining program generation unit 31 is configured by Computer Aided Design (CAD) / Computer Aided Manufacturing (CAM).

[0028] The device control unit 33 controls the operation of the laser oscillator 12, the processing gas supply unit 16, and the axis movement control unit 18 according to the laser processing conditions set by the user and the processing program generated by the processing program generation unit 31. Specifically, the device control unit 33 generates a laser output command according to the processing program and controls the laser oscillator 12 based on the laser output command. This causes the laser beam L to be output at a timing based on the laser output command. The device control unit 33 generates a gas supply command according to the processing program and controls the processing gas supply unit 16 based on the gas supply command. This causes the assist gas to be supplied at a gas type and flow rate based on the gas supply command. The device control unit 33 generates an axis command according to the processing program and controls the axis movement control unit 18 based on the axis command. This controls the drive of the motors connected to the drive axes of the X-, Y-, Z-, B-, and C-axes based on the axis command, thereby driving the drive axes. In other words, the processing head 14 moves in the X-, Y-, and Z-axis directions and the table 11 rotates around the B- and C-axes based on the axis command. The device control unit 33 is, for example, configured with a computerized numerical control (CNC) device.

[0029] The laser processing apparatus 10 configured as described above performs laser processing on the workpiece W by moving the processing head 14 horizontally while irradiating the workpiece W, which is fixed to the table 11 using a jig 111, with laser light L and rotating or tilting the table 11. This allows laser processing to be performed at any position on the workpiece W and at any angle relative to the workpiece W. Here, the laser processing is a cutting process or a drilling process. Drilling processes include trepanning, which cuts a hole into a circular shape according to the hole diameter, and percussion processing, which processes the workpiece by irradiating it with laser light L. Percussion processing is also called piercing. In this case, the laser processing apparatus 10 performs laser processing on the workpiece W at any position and angle using each drive axis and the laser light L. Each drive axis and the laser light L are controlled by a processing program, i.e., a processing program code, generated by the control device 30.

[0030] Fig. 3 is a side view showing an example of the axial configuration of the laser processing device shown in Fig. 1. Fig. 3 is a view of Fig. 2 as seen from the Y-axis direction. The gap amount Zd, which is the distance in the Z-axis direction between the nozzle opening surface 151 and the surface of the workpiece W, is generally set to a few mm or less. This allows the assist gas from the processing nozzle 15 to apply sufficient pressure to the area melted by the laser light L, and the melted area can be properly discharged to the back surface of the workpiece W.

[0031] When processing the surface of the workpiece W by irradiating the laser beam L perpendicularly, the B-axis, which is the tilt axis of the table 11, is driven, and the X-axis, Y-axis, Z-axis of the processing head 14 or the C-axis, which is the rotation axis of the table 11, is driven so that the angle between the nozzle opening surface 151 and the surface of the workpiece W is 0 degrees. When processing the surface of the workpiece W by tilting the laser beam L with respect to the surface, the B-axis of the table 11 is driven, and the X-axis, Y-axis, Z-axis of the processing head 14 or the C-axis of the table 11 is driven so that the angle between the nozzle opening surface 151 and the surface of the workpiece W is a predetermined value.

[0032] Here, a laser processing method using the laser processing apparatus 10 configured as described above will be described. Here, an example will be taken of a case where a hole is drilled using the laser processing apparatus 10. Figures 4 and 5 are flowcharts showing an example of the procedure of the laser processing method.

[0033] First, a user inputs a three-dimensional model, which is data showing the three-dimensional structure of the workpiece W with holes drawn at arbitrary positions, into the machining program generation unit 31 (step S11). Next, the machining program generation unit 31 detects machining shape information including the positions, diameters, and angles of the holes in the three-dimensional model (step S12). After that, the machining program generation unit 31 generates a machining program including machining paths for drilling using the machining shape information (step S13).

[0034] Next, when the user sets the laser processing conditions in the control device 30, the control device 30 accepts the set laser processing conditions as processing condition information (step S14). The laser processing conditions include the focus, output, frequency, duty, etc. of the laser light L. Then, the device control unit 33 reads the generated processing program and processing condition information (step S15).

[0035] Next, the user prepares for the machining process to start (step S16). The preparation for the machining process includes setting up the machining nozzle 15 to the machining head 14, the workpiece W to the table 11, setting the machining start origin, etc. After that, the user starts the execution of the machining program (step S17).

[0036] The axis movement control unit 18 controls the positions and postures of the machining head 14 and the table 11 (step S18) in accordance with the machining program generated by the machining program generation unit 31. In the case of drilling, the machining nozzle 15 is positioned at the center of the target hole.

[0037] Next, piercing is performed by irradiating the workpiece W with laser light L for a short time to open a through hole that penetrates the front and back of the workpiece W (step S19). Specifically, when the processing nozzle 15 is positioned at a specified position, piercing is performed by irradiating the workpiece W with laser light L to melt the workpiece W and supplying assist gas to remove the melted portion. Piercing is performed to ensure an evacuation path for the melted portion during trepanning, which will be described later. In one example, the through hole is formed in the center of the hole to be processed.

[0038] Then, starting from the through hole created by the piercing process, the laser beam L is irradiated while moving horizontally a distance equal to the radius of the hole to be machined, followed by trepanning, in which the laser beam is irradiated along a circumference equal to the size of the hole to be machined (step S20). This completes one hole drilling process. Note that in some cases, drilling is performed only by piercing without trepanning to achieve a small hole diameter. Although drilling has been used as an example here, laser cutting also follows a similar procedure.

[0039] Thereafter, it is confirmed whether or not all the holes in the workpiece W have been drilled (step S21). If all the holes have not been drilled (No in step S21), the process returns to step S18, and the processes from step S18 to step S20 are repeatedly executed until all the holes are formed. If all the holes have been drilled (Yes in step S21), the execution of the processing program ends (step S22). This completes the laser processing method for drilling.

[0040] When drilling holes using the laser processing apparatus 10, a single workpiece W may contain a mixture of holes that are perpendicular to the surface of the workpiece W and holes that are tilted relative to the surface of the workpiece W. In laser processing, tracking control using a capacitance sensor is generally performed to control the gap amount Zd between the nozzle opening surface 151 of the processing nozzle 15 and the surface of the workpiece W. The capacitance sensor measures the capacitance between the nozzle opening surface 151 and the surface of the workpiece W to calculate the distance, and therefore the capacitance becomes unstable when the opposing angle between the nozzle opening surface 151 and the surface of the workpiece W changes. For this reason, when drilling tilted holes, the measurement accuracy of the gap amount Zd decreases. If control is performed using an incorrect measurement value of the gap amount Zd, the processing nozzle 15 will come into contact with the workpiece W, damaging the laser processing apparatus 10 or the workpiece W.

[0041] In the technology described in Patent Document 1, contact is avoided by estimating the error caused by the scanning sensor and moving the position of the processing nozzle 15. However, the measurement value of the scanning sensor changes even if dross adheres to the processing nozzle 15 during laser processing, so it is difficult to accurately estimate the error of the scanning sensor.

[0042] Assuming that the gap amount Zd between the nozzle opening surface 151 and the surface of the workpiece W can be accurately estimated, in order to avoid contact between the processing nozzle 15 and the workpiece W, at least one of the processing nozzle 15 and the workpiece W is usually moved in a direction separating the processing nozzle 15 from the workpiece W. When the processing nozzle 15 and the workpiece W move away from each other, the focal position of the laser light L changes. The change in the focal position of the laser light L changes the laser power density, resulting in a decrease in laser processing quality.

[0043] FIG. 6 is a diagram illustrating an example of contact avoidance and the occurrence of processing defects by a conventional laser processing device. State A shows a normal vertical processing state. The gap amount in the Z-axis direction between the nozzle opening surface 151 of the processing nozzle 15 and the surface of the workpiece W is Zd, and the focal position of the laser light L irradiated from the processing head 14 is Zf. In this example, the optical axis is the same as the central axis Cn of the processing nozzle 15. In state A, the focal position Zf of the laser light L is located on the surface of the workpiece W.

[0044] State B shows a state in which the workpiece W is tilted, causing the processing nozzle 15 to come into contact with the workpiece W. The tilt angle of the workpiece W at this time is assumed to be θv.

[0045] State C shows a state in which the processing position is corrected from state B by increasing the distance between the processing nozzle 15 and the workpiece W in the Z-axis direction to avoid contact. Increasing the distance between the processing nozzle 15 and the workpiece W to avoid contact in this way results in the focal position Zf of the laser light L being shifted from the desired position. In this example, as shown in state A, the desired focal position Zf is on the surface of the workpiece W, but in state C, the focal position Zf is located between the nozzle opening surface 151 of the processing nozzle 15 and the surface of the workpiece W. As a result of the focal position Zf of the laser light L being shifted from the desired position, the power density of the laser light L decreases, making it impossible to melt the workpiece W, which may result in processing defects. Here, the focal position Zf of the laser light L has been described; however, processing defects may also occur due to other laser processing conditions.

[0046] In the above explanation, drilling processing has been used as an example, but the same problems arise if the laser processing is performed by changing the angle between the nozzle opening surface 151 and the surface of the workpiece W.

[0047] In view of the above, the following embodiment describes a laser processing apparatus 10 and a laser processing method that can avoid contact between the processing nozzle 15 and the workpiece W and suppress processing defects caused by correcting the processing position by correcting the processing position commanded when the processing program is generated without using a scanning sensor. However, it goes without saying that the same effect can be obtained even if a scanning sensor is used in the case of processing content in which the error of the scanning sensor is small.

[0048] Embodiment 1 First, the correction process performed by the laser processing apparatus 10 and the laser processing method according to the first embodiment will be described. FIG. 7 is a diagram showing an outline of the procedure for calculating the gap correction amount and the procedure for correcting the nozzle position in the vertical processing nozzle used in the laser processing apparatus according to the first embodiment. Here, the processing nozzle 15 is a generally cylindrical vertical processing nozzle, and it is assumed that the surface of the workpiece W is smooth. It is also assumed that the intersection of the surface of the workpiece W and the central axis Cn of the processing nozzle 15 is the B axis, which is the axis of rotation for rotating the workpiece W. The vertical processing nozzle is a processing nozzle that is suitably used when the cutting surface formed by the laser light L is perpendicular to the surface of the workpiece W. In one example, the vertical processing nozzle is a processing nozzle configured such that the nozzle opening surface 151 is perpendicular to the optical axis and the assist gas is blown in the optical axis direction. In this example, the optical axis is the same as the central axis Cn of the processing nozzle 15. The first embodiment does not use a scanning sensor. That is, the gap amount Zd is not measured using a scanning sensor. In this specification, the term "gap" refers to the distance between the nozzle opening surface 151 on the central axis Cn of the cylindrical processing nozzle 15 and the surface of the workpiece W. Furthermore, the term "gap amount" refers to the distance between the nozzle opening surface 151 on the central axis Cn of the cylindrical processing nozzle 15 and the surface of the workpiece W. In other words, if the point where the nozzle opening surface 151 and the central axis Cn intersect is the nozzle origin On, the gap is the distance between the nozzle origin On on the central axis Cn and the surface of the workpiece W, and the gap amount is that distance.

[0049] State A is a state in which there is no angle between the nozzle opening surface 151 and the surface of the workpiece W, i.e., the nozzle opening surface 151 and the surface of the workpiece W are parallel. When performing perpendicular machining such as surface straight hole machining, laser machining is performed in this state. Laser machining is performed at a position on the surface of the workpiece W that is a gap amount Zd away from the nozzle opening surface 151 of the machining nozzle 15, according to the gap amount specified by the user. When laser machining is performed in this state, the gap amount Zd is not corrected.

[0050] In state B, there is an angle between the nozzle opening surface 151 and the surface of the workpiece W, and the processing nozzle 15 and the surface of the workpiece W are in contact. The processing nozzle 15 and the workpiece W come into contact depending on the relationship between the radius r of the processing nozzle 15, the gap amount Zd, and the tilt angle θv of the workpiece W. This contact can cause damage to the laser processing device 10 or the workpiece W. In this example, the gap amount Zd has not been corrected.

[0051] State C is a state in which there is an angle between the nozzle opening surface 151 and the surface of the workpiece W, and the gap amount Zd is being corrected. In state C, the gap correction amount ΔZ is calculated by the following equation (1) using the radius r of the processing nozzle 15 and the tilt angle θv of the workpiece W. Then, this gap correction amount ΔZ is used to move the processing nozzle 15 in the +Z-axis direction, i.e., in the direction away from the workpiece W, thereby avoiding contact between the processing nozzle 15 and the workpiece W. Avoiding contact between the processing nozzle 15 and the workpiece W enables stable laser processing.

[0052] ΔZ=r tanθv (1)

[0053] In this way, the gap correction amount ΔZ when there is an angle between the nozzle opening surface 151 and the surface of the workpiece W can be calculated using the radius r of the processing nozzle 15 and the tilt angle θv of the workpiece W without using a tracing sensor. The radius r of the processing nozzle 15 and the tilt angle θv of the workpiece W can be determined from the shape of the processing nozzle 15 and the shape of the workpiece W. In other words, the gap correction amount ΔZ when there is an angle between the nozzle opening surface 151 and the surface of the workpiece W can be calculated using the shape of the processing nozzle 15 and the shape of the workpiece W after processing. The corrected gap amount Zd' between the nozzle opening surface 151 and the surface of the workpiece W at this time is expressed by the following equation (2).

[0054] Zd' = Zd + ΔZ (2)

[0055] It is also possible to input all of the corrected gap amounts Zd' corresponding to the tilt angles θv in advance. However, it is unrealistic to create a table of the corrected gap amounts Zd' corresponding to all of the tilt angles θv, and considering implementation in the laser processing apparatus 10, it is preferable to use the calculation method shown in Fig. 7.

[0056] FIG. 8 is a diagram illustrating an example of a procedure for correcting laser processing conditions for a vertical processing nozzle used in the laser processing apparatus according to the first embodiment. FIG. 8 illustrates a method for correcting laser processing conditions using the gap correction amount ΔZ calculated by the method shown in FIG. 7 and the correction result of the gap amount Zd using the gap correction amount ΔZ. Here, an example is shown in which the focal position Zf of the laser beam L is corrected, among the processing conditions. When the point where the nozzle opening surface 151 intersects with the central axis Cn of the processing nozzle 15 is defined as the nozzle origin On, the focal position Zf of the laser beam L is defined as the position where the laser beam L is focused on the central axis Cn based on the nozzle origin On. In other words, the focal position Zf can also be referred to as the distance between the nozzle origin On and the focus of the laser beam L. The nozzle origin On serves as the origin for generating a processing path. Also, here, the processing nozzle 15 is assumed to be a generally cylindrical vertical processing nozzle. Furthermore, an example is given in which the B axis, which is the axis of rotation for rotating the workpiece W, is located at the intersection of the surface of the workpiece W and the central axis Cn of the processing nozzle 15.

[0057] State A is a state in which the nozzle opening surface 151 and the surface of the workpiece W are parallel. The gap amount Zd is a value set by the user. Here, the focal position Zf is located on the surface of the workpiece W. In other words, the focal position Zf and the gap amount Zd are set to be equal. By adjusting the focal point near the surface of the workpiece W, the power density of the laser light L increases. As a result, higher quality processing is possible. In this case, there is no contact between the processing nozzle 15 and the workpiece W, and normal vertical processing is possible. Note that the focal position Zf is not limited to being adjusted to the surface of the workpiece W, and can be set to any value, such as the center of the workpiece W in the thickness direction. In other words, the gap amount Zd may be set so that the focal position Zf is not on the surface of the workpiece W. In this case, the focal position Zf and the gap amount Zd will be different values.

[0058] State B is a state in which the workpiece W has been rotated clockwise around axis B from state A by an inclination angle θv. This shows a state in which one end of the nozzle opening surface 151 of the processing nozzle 15 that emits the laser light L is in contact with the workpiece W. In this state, damage to the processing nozzle 15 or the workpiece W may occur, so laser processing is interrupted by a safety function of the laser processing device 10. In this state, the gap amount at the center axis Cn of the processing nozzle 15 is Zd, so the focal position Zf of the laser light L is present on the surface of the workpiece W. In other words, a state in which the focal position Zf and the gap amount Zd are equal is maintained.

[0059] State C is a state in which, from state B, the position of the processing nozzle 15 has been corrected in the Z-axis direction using a gap correction amount ΔZ = r tan θv calculated by the method shown in FIG. 7 to avoid contact between the processing nozzle 15 and the workpiece W. The corrected gap amount Zd' is shown by equation (2). The corrected gap amount Zd' is the distance in the Z-axis direction between the nozzle origin On of the nozzle opening surface 151 of the processing nozzle 15 and the workpiece W. In this case, unlike state B, the processing nozzle 15 does not come into contact with the workpiece W.

[0060] However, since the focal position Zf is not changed, as the processing nozzle 15 moves in the Z-axis direction, the focal position Zf moves from the surface of the workpiece W in the +Z-axis direction by the gap correction amount ΔZ. In other words, correcting the position of the processing nozzle 15 causes the focal position Zf of the laser light L to deviate from the surface of the workpiece W. In other words, the gap amount Zd' after correction becomes larger than the focal position Zf. This results in a decrease in processing quality when machining an inclined hole.

[0061] State D is a state in which the focal position Zf of the laser beam L is adjusted from state C using the gap correction amount ΔZ calculated by the method shown in FIG. 7 . The corrected focal position Zf′ is expressed by the following equation (3). As shown in equation (3), by correcting the focal position Zf, i.e., the focal length of the laser beam L, by a value equal to the gap correction amount ΔZ, the corrected focal position Zf′ is located at a point at a distance of the corrected gap amount Zd′ from the nozzle opening surface 151 on the central axis Cn of the processing nozzle 15. In this example, the corrected focal position Zf′ is equal to the corrected gap amount Zd′, and the corrected focal position Zf′ of the laser beam L is located on the surface of the workpiece W. As a result, even with the corrected gap amount Zd′, the corrected focal position Zf′ of the laser beam L is at the desired position before gap correction, thereby suppressing degradation of laser processing quality.

[0062] Zf'=Zd+ΔZ (3)

[0063] The above procedure makes it possible to prevent contact between the processing nozzle 15 and the workpiece W and suppress deterioration in laser processing quality when performing inclined processing with a vertical processing nozzle. Here, the focal position with respect to the workpiece W during vertical processing such as surface straight hole processing is the same as the focal position with respect to the workpiece W during inclined processing such as inclined hole processing. In the example of Figure 8, the focal position Zf is set to the surface of the workpiece W in both cases. However, to obtain good processing conditions, the focal positions with respect to the workpiece W during vertical processing and inclined processing may be set to different values. In this case, the correction amount α for inclined processing may be set in advance as shown in the following equation (4).

[0064] Zf'=Zd+ΔZ+α (4)

[0065] While correction of the focal position Zf of the laser beam L has been described here, it may be possible to suppress degradation of laser processing quality by adjusting other laser processing conditions. These other laser processing conditions include at least one of the output power of the laser beam L, pulse conditions, and assist gas pressure. Pulse conditions include pulse width, pulse period, frequency, and duty. These processing conditions can be corrected using the same procedure as described above. Specifically, processing condition adjustment information indicating the relationship between the change in gap amount and the correction amount for the target laser processing condition is calculated in advance. For example, the processing condition adjustment information is a function indicating the relationship between the change in gap amount and the correction amount for the laser processing condition. Once the gap correction amount ΔZ is calculated, the corresponding correction amount for the target laser processing condition is obtained from the processing condition adjustment information. The target laser processing condition can then be corrected according to this correction amount. In this case, the processing condition adjustment information may include a correction amount α for obtaining good processing conditions, as shown in Equation (4). While the above description has been given of an example in which one laser processing condition is corrected, multiple laser processing conditions may also be corrected.

[0066] In this way, by correcting the laser processing conditions in accordance with the gap correction amount ΔZ, it is possible to correct deviations in the laser processing conditions that occur due to correction of the gap amount Zd using the gap correction amount ΔZ. As a result, it becomes possible to perform laser processing with laser processing quality equivalent to that during vertical processing when the nozzle opening surface 151 and the surface of the workpiece W are parallel.

[0067] The laser processing apparatus 10 according to the first embodiment has a configuration similar to that shown in Fig. 1. That is, the laser processing apparatus 10 according to the first embodiment has a processing nozzle 15 that is a generally cylindrical vertical processing nozzle whose nozzle opening surface 151 is perpendicular to the optical axis. In addition, in the laser processing apparatus 10 according to the first embodiment, the gap amount Zd and the laser processing conditions are corrected using this processing nozzle 15 as shown in Fig. 8, so the function of the processing program generation unit 31 of the control device 30 is different from that shown in Fig. 1. Therefore, the description of the same components as those in Fig. 1 will be omitted, and only the configuration of the processing program generation unit 31 will be described.

[0068] The machining program generation unit 31 calculates the position and posture between the machining nozzle 15 and the workpiece W during laser machining, such as drilling, based on the shape of the machining nozzle 15, workpiece shape data showing the three-dimensional structure of the workpiece W on which an arbitrary machining shape is drawn, and a gap amount Zd between the nozzle opening surface 151 of the machining nozzle 15 and the surface of the workpiece W. When the nozzle opening surface 151 of the machining nozzle 15 and the surface of the workpiece W are not parallel to each other, the machining program generation unit 31 calculates a gap correction amount ΔZ so that the machining nozzle 15 and the workpiece W do not come into contact, and generates a machining program that takes the gap correction amount ΔZ into account. Furthermore, the machining program generation unit 31 uses machining condition adjustment information showing the relationship between the change in gap amount and the correction amount of the laser machining conditions to calculate the correction amount of the laser machining conditions corresponding to the gap correction amount ΔZ, and generates laser machining conditions that take the correction amount into account. The machining program generation unit 31 is configured using CAD / CAM.

[0069] 9 is a block diagram showing an example of the configuration of the processing program generation unit of the laser processing apparatus according to Embodiment 1. The processing program generation unit 31 includes a nozzle shape acquisition unit 321, a workpiece shape acquisition unit 322, a processing condition acquisition unit 323, a processing condition storage unit 324, a gap acquisition unit 325, a nozzle information storage unit 326, an inclination angle calculation unit 327, a gap correction amount calculation unit 328, a program generation unit 329, a processing condition adjustment information storage unit 330, a processing condition correction amount calculation unit 331, a processing condition correction unit 332, and a processing information output unit 333.

[0070] The nozzle shape acquisition unit 321 acquires nozzle shape data indicating the shape of the processing nozzle 15 used in the laser processing apparatus 10. Here, the nozzle shape data is information regarding the outer shape of the processing nozzle 15, including information regarding the size of the processing nozzle 15, such as its radius. In one example, the nozzle shape acquisition unit 321 may acquire nozzle shape data directly input by a user to the processing program generation unit 31 via input means such as a keyboard or mouse. In another example, the nozzle shape acquisition unit 321 may acquire nozzle shape data transmitted from another information processing device via a network. In yet another example, the nozzle shape acquisition unit 321 may acquire nozzle shape data stored in a portable storage medium such as a memory card. The nozzle shape data corresponds to the shape data of the processing nozzle 15.

[0071] The workpiece shape acquisition unit 322 acquires workpiece shape data, which is data showing the three-dimensional structure of the workpiece W in which the processed shape obtained by cutting, drilling, etc. is depicted at any position. The workpiece shape data is, for example, a three-dimensional model in which the processed shape is depicted. In one example, the workpiece shape acquisition unit 322 may acquire workpiece shape data that is directly input by a user to the machining program generation unit 31 via input means such as a keyboard or mouse. In another example, the workpiece shape acquisition unit 322 may acquire workpiece shape data transmitted from another information processing device via a network. In yet another example, the workpiece shape acquisition unit 322 may acquire workpiece shape data stored in a portable storage medium such as a memory card.

[0072] The processing condition acquisition unit 323 acquires processing condition information indicating the details of the laser processing conditions performed by the laser processing apparatus 10 and stores the acquired processing condition information in the processing condition storage unit 324. The processing condition information includes at least one selected from the group consisting of the focal position, output, pulse width, pulse period, frequency, duty, and assist gas pressure of the laser light L. The processing condition acquisition unit 323 may acquire processing condition information directly input by a user to the processing program generation unit 31 via input means such as a keyboard or mouse. In another example, the processing condition acquisition unit 323 may acquire processing condition information transmitted from another information processing device via a network. In yet another example, the processing condition acquisition unit 323 may acquire processing condition information stored in a portable storage medium such as a memory card.

[0073] The processing condition storage unit 324 stores processing condition information. The processing condition information is information indicating the conditions for laser processing as described above. That is, the processing condition information includes information indicating the laser processing conditions.

[0074] The gap acquisition unit 325 acquires the gap amount Zd, which is the distance between the nozzle opening surface 151 of the processing nozzle 15 and the surface of the workpiece W. As described above, the gap amount Zd is the distance between the nozzle opening surface 151 at the center axis Cn of the processing nozzle 15 and the surface of the workpiece W. The gap acquisition unit 325 acquires a set value of the gap amount Zd that is directly input by the user to the processing program generation unit 31 via input means such as a keyboard or mouse. It is also possible to set the set value of the gap amount Zd to 0. In this case, it is also possible to adjust the gap amount Zd depending on the processing content using an offset amount that can be separately set on the laser processing apparatus 10 side.

[0075] The nozzle information storage unit 326 stores nozzle information in which the shape parameters of the processing nozzle 15 used to calculate the gap correction amount ΔZ and a correction amount calculation formula used to calculate the gap correction amount ΔZ are associated with nozzle shape data. The correction amount calculation formula, for example, is a function that expresses the gap correction amount ΔZ using the shape parameters of the processing nozzle 15 and the inclination angle θv, which is the angle between the nozzle opening surface 151 and the surface of the workpiece W. In addition, an example of a shape parameter of the processing nozzle 15 in the case of a vertical processing nozzle is the radius r in the direction perpendicular to the central axis Cn of the processing nozzle 15.

[0076] The tilt angle calculation unit 327 calculates the tilt angle θv between the nozzle opening surface 151, which is the surface of the processing nozzle 15 facing the workpiece W, and the surface of the workpiece W at the laser processing position of the workpiece W. Specifically, the tilt angle calculation unit 327 acquires shape parameters of the processing nozzle 15 corresponding to the nozzle shape data from the nozzle information storage unit 326, and calculates the tilt angle θv, which is the angle between the nozzle opening surface 151 and the surface of the workpiece W when the workpiece W is tilt-processed with the processing nozzle 15, using the workpiece shape data, the nozzle shape data, and the shape parameters of the processing nozzle 15.

[0077] The gap correction amount calculation unit 328 uses the tilt angle θv and the shape data of the processing nozzle 15 to calculate a gap correction amount ΔZ for correcting the value of the set gap amount Zd between the nozzle opening surface 151 and the surface of the workpiece W. Specifically, the gap correction amount calculation unit 328 acquires a correction amount calculation formula corresponding to the nozzle shape data from the nozzle information storage unit 326, and calculates the gap correction amount ΔZ by substituting the shape parameters and tilt angle θv of the processing nozzle 15 into the correction amount calculation formula.

[0078] The program generation unit 329 generates a processing path for a region where laser processing, such as cutting or drilling, is performed based on workpiece shape data, which is data indicating the three-dimensional structure of the workpiece W machined into a desired shape. The program generation unit 329 also generates a processing program, which is a computer program for performing laser processing along the processing path while maintaining a corrected gap between the nozzle orifice 151 and the surface of the workpiece W using the gap correction amount ΔZ. In one example, templates of processing programs for various processes, such as cutting and drilling, are prepared in advance. The template processing program is a program defined so that the processing head 14 moves along the processing path using items included in the processing condition information as parameters. Here, the processing program references the laser processing conditions from the processing condition information. In other words, the program generation unit 329 generates a processing path for laser processing using a three-dimensional model indicating the shape of the workpiece W machined into a desired shape, and generates a processing program including the processing path. The laser processing conditions used in this processing program are acquired from the processing condition information associated with the processing position. Furthermore, the program generation unit 329 corrects the gap amount Zd at the position where laser processing is performed in the processing program using the gap correction amount ΔZ. As a result, even when the gap amount Zd is corrected, it is possible to generate, without manual intervention, a processing program that performs laser processing while maintaining the distance between the processing nozzle 15 and the surface of the workpiece W at the corrected gap amount Zd' corrected using the gap correction amount ΔZ.

[0079] The machining condition adjustment information storage unit 330 stores machining condition adjustment information for calculating the correction amount of a determined laser machining condition among the laser machining conditions in order to suppress deterioration in machining quality caused by correction of the gap amount Zd using the gap correction amount ΔZ. The machining condition adjustment information is, for example, information indicating the relationship between the amount of change in the gap amount and the correction amount of the laser machining condition that results in machining quality equal to or better than that before correcting the gap amount Zd when the gap amount Zd is corrected using the gap correction amount ΔZ. The machining condition adjustment information may be a formula or table-format data.

[0080] The processing condition correction amount calculation unit 331 uses the processing condition adjustment information acquired from the processing condition adjustment information storage unit 330 to calculate the correction amount of the laser processing conditions corresponding to the gap correction amount ΔZ calculated by the gap correction amount calculation unit 328.

[0081] The machining condition correcting unit 332 generates corrected machining condition information by correcting the laser machining conditions using the correction amount of the laser machining conditions calculated by the machining condition correction amount calculating unit 331. The machining condition correcting unit 332 stores the corrected machining condition information in the machining condition storage unit 324. The laser machining conditions to be corrected are predetermined and may be one or more. The machining condition correcting unit 332 stores the corrected machining condition information in the machining condition storage unit 324 in association with the machining position. In one example, the machining condition correcting unit 332 may generate multiple pieces of corrected machining condition information depending on the shape of the machining nozzle 15 and the tilt angle θv between the machining nozzle 15 and the workpiece W.

[0082] The processing information output unit 333 outputs the processing program and the corrected processing condition information to the device control unit 33. If there is a processing position where the processing condition information is not corrected, the processing information output unit 333 also outputs the processing condition information to the device control unit 33.

[0083] 10 is a diagram showing an example of the relationship between input data and output data of the machining program generation unit. The input data to the machining program generation unit 31 are nozzle shape data, workpiece shape data, machining condition information, and a set value of the gap amount Zd between the machining nozzle 15 and the workpiece W. The output data from the machining program generation unit 31 is a machining program including a nozzle position taking into account the gap correction amount ΔZ, and post-correction machining condition information according to the gap correction amount ΔZ. If it is necessary to switch laser machining conditions during laser machining, multiple pieces of post-correction machining condition information may be output.

[0084] An overview of the processing in the machining program generation unit 31 when performing hole drilling with the laser machining apparatus 10 will be described. The machining program generation unit 31 generates a machining program for drilling based on workpiece shape data. The machining program generation unit 31 also calculates the gap correction amount ΔZ at each hole position from the nozzle shape data and corrects the gap amount at each hole position in the generated machining program. Furthermore, the machining program generation unit 31 generates and outputs a machining program that switches the laser machining conditions to be used according to the gap correction amount ΔZ at each hole position. The laser machining conditions to be switched may be prepared separately on the laser machining apparatus 10 side or may be output by the machining program generation unit 31. In this way, the machining program generation unit 31 converts input data into output data.

[0085] The device control unit 33 of the laser processing device 10 according to the first embodiment controls the operations of the laser oscillator 12, processing gas supply unit 16, and axis movement control unit 18 in accordance with the processing program generated by the processing program generation unit 31 and the corrected processing condition information. In particular, the device control unit 33 controls the axis movement control unit 18 so that the value of the corrected gap amount Zd' becomes the sum of the set gap amount Zd and the gap correction amount ΔZ. Furthermore, the device control unit 33 controls the laser oscillator 12 and processing gas supply unit 16 so that the corrected laser processing conditions indicated by the corrected processing condition information are achieved.

[0086] Next, a laser processing method will be described. Figures 11 and 12 are flowcharts showing an example of a processing procedure of the laser processing method according to the first embodiment. First, a user inputs nozzle shape data indicating the shape of the processing nozzle 15 and workpiece shape data indicating the shape of the workpiece W to the processing program generation unit 31. As a result, the nozzle shape acquisition unit 321 acquires the nozzle shape data (step S31), and the workpiece shape acquisition unit 322 acquires the workpiece shape data (step S32).

[0087] Furthermore, the user sets laser processing conditions in the processing program generation unit 31. As a result, the processing condition acquisition unit 323 acquires the set laser processing conditions as processing condition information (step S33). The processing condition information is stored in the processing condition storage unit 324. Furthermore, the user sets a gap amount Zd between the nozzle opening surface 151 and the surface of the workpiece W in the processing program generation unit 31. As a result, the gap acquisition unit 325 acquires the set value of the gap amount Zd (step S34).

[0088] Next, the inclination angle calculation unit 327 determines the nozzle shape from the input nozzle shape data and acquires shape parameters of the processing nozzle 15 corresponding to the nozzle shape from the nozzle information stored in the nozzle information storage unit 326 (step S35). The inclination angle calculation unit 327 also calculates the inclination angle θv between the nozzle orifice surface 151 and the surface of the workpiece W using the nozzle shape data, the shape parameters of the processing nozzle 15, and the workpiece shape data (step S36). In one example, the inclination angle calculation unit 327 calculates the inclination angle θv from the shape of the workpiece W at the machining position using the shape data of the processing nozzle 15 and a three-dimensional model representing the shape of the workpiece W machined into the desired shape. That is, the inclination angle calculation unit 327 calculates the inclination angle θv between the nozzle orifice surface 151 and the surface of the workpiece W on a computer system using the three-dimensional model of the processing nozzle 15 generated from the nozzle shape data and the shape parameters of the processing nozzle 15, and the three-dimensional model of the workpiece W, which is the workpiece shape data. The tilt angle θv is determined according to the angle of the cut surface in the 3D model of the workpiece W relative to the surface of the workpiece W. This makes it possible to obtain the tilt angle θv using the data used to generate the machining program. For example, if the object to be machined is a hole, the tilt angle θv is calculated using the position, diameter, and angle of the hole obtained from the workpiece shape data. Step S36 corresponds to a tilt angle calculation step in which the control device 30 calculates the tilt angle θv between the nozzle opening surface 151, which is the surface of the processing nozzle 15 facing the workpiece W, and the surface of the workpiece W at the laser processing position of the workpiece W.

[0089] Thereafter, the gap correction amount calculation unit 328 acquires, from the nozzle information stored in the nozzle information storage unit 326, shape parameters of the processing nozzle 15 corresponding to the nozzle shape obtained from the input nozzle shape data, and a correction amount calculation formula for calculating the gap correction amount ΔZ (step S37). Furthermore, the gap correction amount calculation unit 328 calculates the gap correction amount ΔZ corresponding to the inclination angle θv between the nozzle opening surface 151 and the surface of the workpiece W and the shape parameters of the processing nozzle 15, using the acquired correction amount calculation formula (step S38). Step S38 corresponds to a gap correction amount calculation step in which the control device 30 calculates the gap correction amount ΔZ for correcting the set gap amount between the nozzle opening surface 151 and the surface of the workpiece W, using the inclination angle θv and the shape data of the processing nozzle 15.

[0090] Next, the program generation unit 329 generates a machining program including a machining path for performing laser machining based on the workpiece shape data (step S39). Furthermore, the program generation unit 329 corrects the gap amount Zd at the position where laser machining is performed in the machining program using the gap correction amount ΔZ (step S40). The gap amount Zd corrected with the gap correction amount ΔZ becomes the corrected gap amount Zd'.

[0091] Thereafter, the processing condition correction amount calculation unit 331 calculates the correction amount of the laser processing condition corresponding to the gap correction amount ΔZ based on the processing condition adjustment information (step S41). Step S41 corresponds to a processing condition correction amount calculation step in which the control device 30 calculates the correction amount of the laser processing condition corresponding to the gap correction amount ΔZ using the processing condition adjustment information indicating the relationship between the amount of change in the gap amount and the correction amount of the laser processing condition.

[0092] The processing condition correcting unit 332 uses the calculated correction amount of the laser processing condition to generate corrected processing condition information by correcting the processing condition information in the processing condition storage unit 324 (step S42). Step S42 corresponds to a processing condition correcting step in which the control device 30 adjusts the laser processing conditions using the correction amount of the laser processing condition.

[0093] Then, the processing information output unit 333 outputs the processing program and the corrected processing condition information to the device control unit 33. As a result, the device control unit 33 reads the processing program and the corrected processing condition information (step S43).

[0094] When multiple locations on the workpiece W are to be machined, the gap correction amount ΔZ and the correction amount of the laser processing conditions are calculated for each location. Then, the gap amount Zd is corrected at the part in the processing program where laser processing is performed for each location, and post-correction processing condition information for each location is generated.

[0095] Thereafter, similarly to the processing from step S16 to step S17 in FIG. 4, the user prepares for the machining process, and the execution of the machining program is started (steps S44 to S45).

[0096] Next, the device control unit 33 controls the position and posture of the machining head 14 and the table 11 in accordance with the machining program (step S46). The device control unit 33 also switches the laser machining conditions to post-correction machining condition information, which are laser machining conditions according to the gap correction amount ΔZ (step S47). Thereafter, similar to the processing from step S19 to step S20 in FIG. 5, piercing is performed, followed by trepanning (steps S48 to S49). Note that although drilling is illustrated here, machining other than drilling is also performed in a similar manner. Steps S46 to S49 correspond to a device control step in which the control device 30 controls the axis movement control unit 18 so that the post-correction gap amount is the sum of the set gap amount and the gap correction amount ΔZ.

[0097] Thereafter, the device control section 33 determines whether all the processing has been performed (step S50), and if all the processing has not been performed (No in step S50), the processes from step S46 to step S49 are repeatedly executed. If all the processing has been performed (Yes in step S50), the execution of the processing program ends (step S51), and the laser processing method ends.

[0098] As described above, in the first embodiment, in the laser processing apparatus 10 having a vertical processing nozzle as the processing nozzle 15, the processing program generation unit 31 recognizes the shape of the processing nozzle 15, calculates a gap correction amount ΔZ for the gap between the processing nozzle 15 and the workpiece W to avoid contact, and generates a processing program including a processing path using the calculated gap correction amount ΔZ and corrected processing condition information. By performing laser processing using a processing program based on the processing path generated taking the gap correction amount ΔZ into account and the corrected processing condition information, contact between the processing nozzle 15 and the workpiece W can be avoided while achieving higher quality laser processing than conventional methods. For example, even if the position of the processing nozzle 15 is changed from a state in which the focal position Zf of the laser light L is set on the surface of the workpiece W during vertical processing to an angled processing state in order to avoid contact, laser processing can be performed without the focal position Zf' of the laser light L being displaced from the surface of the workpiece W.

[0099] Embodiment 2 State A in FIG. 6 of the first embodiment shows a case where the processing nozzle 15 can be installed approximately perpendicular to the surface of the workpiece W. In other words, the central axis Cn of the processing nozzle 15 can be installed approximately perpendicular to the surface of the workpiece W. Because the nozzle opening surface 151 of the processing nozzle 15 is perpendicular to the central axis Cn, the assist gas is blown perpendicular to the nozzle opening surface 151 and is also blown perpendicularly onto the surface of the workpiece W. In this case, when laser processing is performed, the assist gas from the processing nozzle 15 can apply sufficient pressure to the area melted by the laser light L. As a result, the melted area can be properly discharged to the back side of the workpiece W.

[0100] On the other hand, state C in Figure 6 shows a case where the processing nozzle 15 is installed at an angle with respect to the surface of the workpiece W. In such a case, the assist gas from the processing nozzle 15 is sprayed at an angle that is not perpendicular to the surface of the workpiece W. Therefore, if the tilt angle θv becomes large, the flow of assist gas from the processing nozzle 15 will be deflected on the surface of the workpiece W, and sufficient pressure cannot be applied to the area to be melted by the laser light L. Note that the tilt angle θv is the angle between the nozzle opening surface 151 and the surface of the workpiece W, but it is also the angle of the central axis Cn of the processing nozzle 15 with respect to the normal to the surface of the workpiece W.

[0101] To solve this problem, in the second embodiment, an inclined processing nozzle is used, which is a processing nozzle 15 whose nozzle opening surface 151 is inclined with respect to the central axis Cn. FIG. 13 is a diagram showing an example of the configuration of an inclined processing nozzle used in the laser processing apparatus according to the second embodiment. In the second embodiment, a processing nozzle 15a is used instead of the processing nozzle 15 of the first embodiment. The processing nozzle 15a is an inclined processing nozzle.

[0102] The optical axis of the processing head 14 is assumed to coincide with the central axis Cn of the processing nozzle 15a. As shown in FIG. 13, the processing nozzle 15a is a nozzle having a nozzle opening surface 151 that is inclined at an angle that is not perpendicular to the central axis Cn. Specifically, the processing nozzle 15a has a first cylindrical portion 152 having a constant diameter in a direction perpendicular to the central axis Cn, and a second cylindrical portion 153 provided at the end of the first cylindrical portion 152 from which the laser light L is emitted and having the nozzle opening surface 151 that is inclined at an angle that is not perpendicular to the central axis Cn. The nozzle opening surface 151 of the second cylindrical portion 153 is inclined at an angle θc with respect to a plane perpendicular to the central axis Cn of the processing nozzle 15a. This angle θc is referred to as the nozzle inclination angle θc. The diameter of the second cylindrical portion 153 narrows along the nozzle opening surface 151. With such a processing nozzle 15a, the nozzle opening surface 151 can be made nearly parallel to the surface of the workpiece W when the workpiece W is tilted by rotating around the B axis. This allows the assist gas to apply sufficient pressure to the melting point by the laser light L, suppressing a decrease in the laser processing quality during tilt processing.

[0103] The laser processing apparatus 10 according to the second embodiment has the same configuration as that of the first embodiment, except for the processing nozzle 15a. That is, in the first embodiment, the processing nozzle 15 is a vertical processing nozzle, but in the second embodiment, the processing nozzle 15a is an inclined processing nozzle.

[0104] When the proportion of inclined machining is higher than that of perpendicular machining in the shape to be machined on the workpiece W, or when sufficient machining quality cannot be obtained for inclined machining with a normal vertical machining nozzle, it is possible to consider using an inclined machining nozzle. Here, it is preferable that the nozzle inclination angle θc of the inclined machining nozzle to be used is the same as the inclination angle θv of the workpiece W, but even if they are different, as described above, the effect of improving machining quality can be obtained as long as sufficient pressure can be applied.

[0105] In the second embodiment, examples of shape parameters and a formula for calculating the gap correction amount ΔZ for avoiding contact between the processing nozzle 15a and the workpiece W when the above-mentioned inclined processing nozzle is used are shown. In addition, the second embodiment also shows an example of correction of the laser processing conditions accompanying the correction of the gap amount Zd.

[0106] 14 is a diagram showing an outline of a procedure for calculating a gap correction amount and a procedure for correcting the nozzle position in an inclined processing nozzle used in a laser processing apparatus according to embodiment 2. Here, the inclined processing nozzle, which is processing nozzle 15a, is a generally cylindrical processing nozzle that has been beveled at an arbitrary position, and the surface of the workpiece W is assumed to be smooth. Also, the B axis, which is the rotation axis, is assumed to be located at the intersection of the surface of the workpiece W and the central axis Cn of the processing nozzle 15a. In embodiment 2, a scanning sensor is not used either.

[0107] The inclined processing nozzle is a processing nozzle 15a that is suitably used when forming a cutting surface having an inclination angle that is not perpendicular to the surface of the workpiece W. In one example, the nozzle opening surface 151 of the inclined processing nozzle is inclined at a nozzle inclination angle θc that is not perpendicular to the central axis Cn of the processing nozzle 15a. As a result, the processing nozzle 15a has a configuration in which the assist gas is blown out at an angle to the central axis Cn.

[0108] In the following description, the nozzle origin On used to generate a machining path is defined as the position on an imaginary plane perpendicular to the central axis Cn of the machining nozzle 15a that passes through the boundary between the first cylindrical portion 152 and the second cylindrical portion 153. The gap amount Zd between the machining nozzle 15a and the workpiece W refers to the distance between the nozzle opening surface 151 and the surface of the workpiece W at the central axis Cn of the tilt machining nozzle.

[0109] In state A, the nozzle opening surface 151 and the surface of the workpiece W are parallel. The surface of the workpiece W, which is inclined at an inclination angle θv, is parallel to the nozzle opening surface 151 of the processing nozzle 15a. When performing inclined processing, the processing is performed in this state. The gap amount between the processing nozzle 15a and the surface of the workpiece W is controlled according to the gap setting value set by the user. Because the nozzle opening surface 151 and the surface of the workpiece W are parallel, the gap amount Zd is the same at any position on the nozzle opening surface 151.

[0110] The machining program takes into account the gap amount between the nozzle origin On on the central axis Cn and the surface of the workpiece W. Therefore, correction of the gap amount Zd due to the nozzle shape of the machining nozzle 15a is taken into account. The correction amount Zn due to the nozzle shape is expressed by the following equation (5) using the radius r of the machining nozzle 15a and the nozzle inclination angle θc of the nozzle opening surface 151 of the machining nozzle 15a. Note that the nozzle inclination angle θc is the angle of the nozzle opening surface 151 with respect to an imaginary plane perpendicular to the central axis Cn of the boundary between the first cylindrical portion 152 and the second cylindrical portion 153. In this case, the imaginary plane corresponds to the XY plane.

[0111] Zn=r tanθc (5)

[0112] In state A, the gap amount between the nozzle origin On and the surface of the workpiece W is controlled to be Zd+Zn. In addition, the nozzle opening surface 151 and the surface of the workpiece W can be brought into close proximity over a wide area, preventing the assist gas from diverting to the surface of the workpiece W and allowing sufficient pressure to be applied to the melting point by the laser light L. As a result, stable processing is possible. Note that when laser processing is performed in this state, the gap amount Zd+Zn is not corrected.

[0113] In state B, there is an angle between the nozzle opening surface 151 and the surface of the workpiece W, and the processing nozzle 15a and the surface of the workpiece W are in contact. Specifically, the inclination angle θv of the surface of the workpiece W is 0 degrees, and the tip of the processing nozzle 15a is in contact with the surface of the workpiece W. The processing nozzle 15a and the workpiece W come into contact depending on the relationship between the radius r of the processing nozzle 15a, the gap amount Zd, the inclination angle θv of the workpiece W, and the nozzle inclination angle θc of the processing nozzle 15a. This contact can cause damage to the laser processing device 10 or the workpiece W. In this example, correction based on the nozzle shape is performed, but correction of the gap amount based on the rotation of the workpiece W is not performed.

[0114] State C is a state in which there is an angle between the nozzle opening surface 151 and the surface of the workpiece W, and the gap amount is being corrected. In state C, the gap correction amount ΔZ is calculated according to the following equation (6) using the radius r of the processing nozzle 15a, the gap amount Zd, the tilt angle θv of the workpiece W, and the nozzle tilt angle θc of the processing nozzle 15a. Then, this gap correction amount ΔZ is used to move the nozzle position in the +Z axis direction, i.e., in the direction away from the workpiece W, thereby avoiding contact between the processing nozzle 15a and the workpiece W. Avoiding contact between the processing nozzle 15a and the workpiece W enables stable laser processing.

[0115] ΔZ=r|tanθc-tanθv| (6)

[0116] As described above, without using a tracing sensor, it is possible to calculate the gap correction amount ΔZ for the gap amount Zd+Zn between the nozzle origin On and the surface of the workpiece W when machining the workpiece W at a tilt angle θv using an inclined machining nozzle using the radius r of the machining nozzle 15a, the gap amount Zd, the tilt angle θv of the workpiece W, and the nozzle tilt angle θc of the machining nozzle 15a. The radius r and nozzle tilt angle θc of the machining nozzle 15a, and the tilt angle θv of the workpiece W can be determined from the shape of the machining nozzle 15a and the shape of the workpiece W. In other words, it is possible to calculate the gap correction amount ΔZ for the gap amount Zd+Zn between the nozzle origin On and the surface of the workpiece W when machining the workpiece W at a tilt angle θv using an inclined machining nozzle using the shape of the machining nozzle 15a, the shape of the workpiece W after machining, and the gap amount Zd.

[0117] Furthermore, while the inclined machining nozzle with a nozzle tilt angle θc has been described as an example, if the nozzle tilt angle θc is 0 degrees, the nozzle will be the vertical machining nozzle described in the first embodiment. In this case, the correction amount Zn due to the nozzle shape is 0 from equation (5). Furthermore, the gap correction amount ΔZ is r·tan θv from equation (6), which is the same as equation (1). That is, the gap correction amount calculation unit 328 can calculate the gap correction amount ΔZ using the radius r in the direction perpendicular to the central axis Cn of the machining nozzle 15, 15a, the nozzle tilt angle θc, and the tilt angle θv of the workpiece W. As a result, the corrected gap amount Zd' is Zd + ΔZ, which has the same form as that calculated in the first embodiment. In this way, the corrected gap amount Zd' in the second embodiment is expressed as Zd + Zn + ΔZ using the nozzle tilt angle θc, and can be used for both vertical machining nozzles and inclined machining nozzles.

[0118] It is also possible to consider a method of inputting in advance all of the gap amounts Zd+Zn+ΔZ between the nozzle origin On and the surface of the workpiece W, which correspond to the tilt angle θv of the workpiece W and the nozzle tilt angle θc. However, it is unrealistic to create a table of gap amounts corresponding to all nozzle tilt angles θc for all tilt angles θv of the workpiece W, and considering implementation in the laser processing device 10, it is preferable to use the calculation method shown in Fig. 14.

[0119] FIG. 15 is a diagram illustrating an example of a procedure for correcting laser processing conditions for an inclined processing nozzle used in the laser processing apparatus according to the second embodiment. FIG. 15 illustrates a method for correcting laser processing conditions using the nozzle shape correction amount Zn and gap correction amount ΔZ calculated using the method shown in FIG. 14 and the position correction results using the nozzle shape correction amount Zn and gap correction amount ΔZ. This example illustrates correcting the focal position Zf of the laser beam L, among other laser processing conditions. Also, here, the inclined processing nozzle 15a is assumed to be a generally cylindrical shape cut obliquely at an arbitrary position. The gap amount Zd is corrected by moving the processing nozzle 15a in the Z-axis direction. In this example, the intersection of the central axis Cn of the processing nozzle 15a and the surface of the workpiece W is the B-axis, which is the axis of rotation for rotating the workpiece W. The workpiece W rotates clockwise or counterclockwise around the B-axis. Furthermore, here too, the position where the central axis Cn of the processing nozzle 15a passes through on a virtual plane perpendicular to the central axis Cn, which passes through the boundary between the first cylindrical portion 152 and the second cylindrical portion 153, is defined as the nozzle origin On used to generate the processing path.

[0120] State A is a state in which the nozzle opening surface 151 and the surface of the workpiece W are parallel. The gap amount Zd is a value set by the user. In FIG. 15, the nozzle opening surface 151 and the surface of the workpiece W are parallel, so the gap amount Zd is the same at any position on the nozzle opening surface 151. When the nozzle opening surface 151 and the surface of the workpiece W are not parallel, the gap amount Zd is the distance in the Z-axis direction between the nozzle opening surface 151 and the surface of the workpiece W on the central axis Cn of the nozzle that passes through the nozzle origin On. Note that the gap amount between the nozzle origin On and the surface of the workpiece W along the central axis Cn is Zd + Zn, which further takes into account the correction amount Zn due to the nozzle shape shown in equation (5).

[0121] Here, the position on the central axis Cn of the processing nozzle 15a that is moved a distance of the gap amount Zd from the nozzle opening surface 151 is set to be equal to the focal position Zf of the laser light L. In other words, the gap amount Zd is set so that the focal position Zf of the laser light L is on the surface of the workpiece W. By adjusting the focal position Zf near the surface of the workpiece W, the power density of the laser light L can be increased, enabling higher quality processing. In this case, there is no contact between the processing nozzle 15a and the workpiece W, and normal inclined processing is possible. Note that the focal position Zf is not limited to being adjusted to the surface of the workpiece W, and can be set to any value, such as the center in the thickness direction of the workpiece W. In other words, the gap amount Zd may be set so that the focal position Zf is not on the surface of the workpiece W.

[0122] State B is a state in which the workpiece W is rotated counterclockwise from state A by an inclination angle θv. This causes contact between the processing nozzle 15a and the workpiece W. In this state, damage to the processing nozzle 15a or the workpiece W may occur, so laser processing is interrupted by a safety function of the laser processing device 10. In this state, the gap amount at the center axis Cn of the processing nozzle 15a is Zd, so the focal position Zf of the laser light L is located on the surface of the workpiece W.

[0123] State C is a state in which, from state B, the nozzle position has been corrected in the Z-axis direction using the method shown in FIG. 14, i.e., the gap correction amount ΔZ calculated using equation (6), to avoid contact between the tilted machining nozzle and the workpiece W. The gap amount Zd' between the corrected nozzle origin On and the surface of the workpiece W is expressed by the following equation (7). The corrected gap amount Zd' is the distance between the nozzle origin On and the workpiece W on the central axis Cn of the machining nozzle 15a. Therefore, the corrected gap amount Zd' also includes the correction amount Zn due to the shape of the tilted machining nozzle shown in equation (5). In this case, unlike state B, the tilted machining nozzle does not come into contact with the workpiece W.

[0124] Zd' = Zd + Zn + ΔZ (7)

[0125] However, because the focal position Zf is not changed, as the processing nozzle 15a moves in the Z-axis direction, the focal position Zf moves from the surface of the workpiece W in the +Z-axis direction by the gap correction amount ΔZ. In other words, on the central axis Cn of the processing nozzle 15a, the position moved by the distance of the gap amount Zd' from the nozzle origin On is on the surface of the workpiece W, but the focal position Zf of the laser light L is off the surface of the workpiece W. This causes a deterioration in the laser processing quality when vertical hole processing is performed in state C.

[0126] State D is a state in which the focal position Zf of the laser beam L is adjusted from state C using the method shown in FIG. 14, i.e., the gap correction amount ΔZ calculated using equation (6). The corrected focal position Zf' is expressed by the following equation (8). However, in equation (8), the focal position Zf and the corrected focal position Zf' are based on the intersection point between the central axis Cn and the nozzle opening surface 151. Therefore, the nozzle shape correction amount Zn is used to correct the difference between the nozzle origin On on the central axis Cn and the position of the nozzle opening surface 151. By correcting the focal position Zf', i.e., the focal length of the laser beam L, as shown in equation (8), the focal position Zf' is located at a point that is a distance of the corrected gap amount Zd' from the nozzle origin On on the central axis Cn of the processing nozzle 15a. In this example, the corrected focal position Zf' of the laser beam L is located on the surface of the workpiece W.

[0127] Zf' = Zd + Zn + ΔZ (8)

[0128] The above procedure makes it possible to prevent contact between the processing nozzle 15a and the workpiece W and suppress deterioration in laser processing quality when performing vertical processing with the processing nozzle 15a. Here, the focal position with respect to the workpiece W is the same during vertical processing such as surface straight hole processing and during inclined processing such as inclined hole processing. In the example of Figure 15, the focal position Zf is set to the surface of the workpiece W in both cases. However, to obtain good processing conditions, the focal position with respect to the workpiece W may be set to different values ​​during vertical processing and inclined processing. In this case, a correction amount β for vertical processing may be set in advance as shown in the following equation (9).

[0129] Zf' = Zd + Zn + ΔZ + β (9)

[0130] While correction of the focal position Zf of the laser beam L has been described here, it may be possible to suppress degradation of laser processing quality by adjusting other laser processing conditions. These other laser processing conditions include the output power of the laser beam L, pulse conditions, and gas pressure. Pulse conditions include the pulse width, pulse period, frequency, and duty. These processing conditions can be corrected using the same procedure as described above when changing them. Specifically, processing condition adjustment information indicating the relationship between the change in gap amount and the correction amount for the target laser processing condition is calculated in advance. For example, the processing condition adjustment information is a function indicating the relationship between the change in gap amount and the correction amount for the laser processing condition. Once the gap correction amount ΔZ is calculated, the corresponding correction amount for the target laser processing condition is obtained from the processing condition adjustment information. The target laser processing condition can then be corrected according to this correction amount. In this case, the processing condition adjustment information may also include a correction amount β for obtaining good processing conditions, as shown in Equation (9). While the above description has been given of correcting one laser processing condition, multiple laser processing conditions may also be changed.

[0131] The configuration of the laser processing apparatus 10 according to the second embodiment is the same as that described with reference to FIG. 9 in the first embodiment. However, as described above, in the second embodiment, the processing nozzle 15a is an inclined processing nozzle, which has a different shape from the vertical processing nozzle of the first embodiment. Therefore, the shape parameters of the processing nozzle 15a in the nozzle information stored in the nozzle information storage unit 326 include the radius r of the first cylindrical portion 152 and the nozzle inclination angle θc of the nozzle opening surface 151. Furthermore, the gap correction amount calculation unit 328 calculates the gap correction amount ΔZ using the radius r in the direction perpendicular to the central axis Cn of the processing nozzle 15a, the nozzle inclination angle θc, which is the angle of the nozzle opening surface 151 relative to the XY plane, and the inclination angle θv between the workpiece W and the nozzle opening surface 151. In other words, the gap correction amount calculation unit 328 differs from the first embodiment in that it uses equations (5) and (6) to calculate the gap correction amount ΔZ. This makes it possible to calculate the gap correction amount ΔZ at which the workpiece W and the processing nozzle 15a do not come into contact with each other, according to the inclination angle θv of the surface of the workpiece W and the nozzle inclination angle θc, without using a tracing sensor.

[0132] 11 and 12 of the first embodiment. However, in step S38, the gap correction amount calculation unit 328 calculates the gap correction amount ΔZ from equation (6) using, as shape parameters of the processing nozzle 15a, the radius r of the processing nozzle 15a in a direction perpendicular to the central axis Cn and the nozzle inclination angle θc, which is the angle of the nozzle opening surface 151 with respect to the XY plane. In step S40, the program generation unit 329 corrects the gap amount Zd using equation (7) to calculate the corrected gap amount Zd'.

[0133] In the second embodiment, the laser processing apparatus 10 having an inclined processing nozzle recognizes the shape of the processing nozzle 15a in the processing program generation unit 31, calculates a gap correction amount ΔZ for the gap between the processing nozzle 15a and the workpiece W to avoid contact, and generates a processing program including a processing path using the gap correction amount ΔZ and corrected processing condition information. By performing laser processing using a processing program based on the processing path generated in consideration of the gap correction amount ΔZ and the corrected processing condition information, it is possible to avoid contact between the processing nozzle 15a and the workpiece W and achieve higher quality laser processing than conventional methods even during inclined processing.

[0134] Embodiment 3 The laser processing apparatus 10 of the third embodiment has a configuration similar to that of the first and second embodiments, but performs laser processing by manually or automatically switching between multiple processing nozzles 15, 15a of different shapes. For example, the processing shape of the workpiece W to be processed may include both straight holes and inclined holes, and the inclined holes may also include holes with various inclination angles. In this case, good processing quality can be obtained when laser processing straight holes using a normal vertical processing nozzle, but the processing quality may be degraded when laser processing inclined holes using a vertical processing nozzle. Conversely, good processing quality can be obtained when laser processing inclined holes using an inclined processing nozzle, but the processing quality may be degraded when laser processing straight holes using an inclined processing nozzle. Therefore, in the third embodiment, a laser processing apparatus 10 and a laser processing method are described that can change the nozzle depending on the inclination angle of the processed hole. While it is desirable to prepare inclined processing nozzles corresponding to all inclination angles θv, this is not practical. For this reason, a case where two processing nozzles, a vertical processing nozzle and an inclined processing nozzle, are switched between is described here. However, the number of switching processing nozzles 15, 15a is not limited to two. When the number of processing nozzles 15, 15a is three or more, a plurality of inclined processing nozzles having different nozzle inclination angles θc are prepared.

[0135] 16 is a diagram showing an example of laser processing conditions during laser processing using a vertical processing nozzle and an inclined processing nozzle used in the laser processing apparatus according to the third embodiment. Here, the laser processing apparatus 10 is assumed to have two types of processing nozzles 15, 15a: a vertical processing nozzle 15 having a nozzle opening surface 151 with a nozzle inclination angle of 0 degrees, and a inclined processing nozzle 15a having a nozzle opening surface 151 with an inclination angle of θc degrees. The radius of the vertical processing nozzle in a direction perpendicular to the central axis Cn is r. The radius of the first cylindrical portion 152 of the inclined processing nozzle in a direction perpendicular to the central axis Cn is also r.

[0136] 16, the type of processing nozzle 15, 15a to be used is specified depending on the inclination angle θv of the surface of the workpiece W relative to the XY plane, centered on the B axis, which is parallel to the Y axis. When the inclination angle θv of the surface of the workpiece W is 0≦θv<θc / 2, a vertical processing nozzle is used, as shown in states A and B. In state B, as described in the first embodiment, the gap correction amount ΔZ shown in equation (1) is used to correct the gap amount between the processing nozzle 15 and the surface of the workpiece W to the gap amount Zd' shown in equation (2). Furthermore, the correction amount of the laser processing condition corresponding to the gap correction amount ΔZ is calculated from a function showing the relationship between the change in gap amount Zd and the correction amount of the laser processing condition to be corrected, and the target laser processing condition is corrected using this correction amount of the laser processing condition.

[0137] When the inclination angle θv of the surface of the workpiece W is θc / 2≦θv≦θc, an inclined machining nozzle is used, as shown in states C and D. Furthermore, in states C and D, as described in embodiment 2, the gap correction amount ΔZ shown in equation (6) is used to correct the gap amount between the machining nozzle 15a and the surface of the workpiece W to become the gap amount Zd' shown in equation (7). Furthermore, the correction amount of the laser machining conditions corresponding to the gap correction amount ΔZ is calculated from a function showing the relationship between the change in the gap amount Zd and the correction amount of the laser machining conditions to be corrected, and the target laser machining conditions are corrected using this correction amount of the laser machining conditions.

[0138] Note that the angle shown in Figure 16 is just an example, and the angle at which the processing nozzles 15, 15a are switched does not have to be θc / 2. In the case of the example of drilling, the angle at which the processing nozzles 15, 15a are switched can be changed as long as it is an angle that can obtain the required laser processing quality for both straight holes and inclined holes. In this example, a vertical processing nozzle and an inclined processing nozzle are used, but depending on the processing content, multiple processing nozzles 15 may be used, including processing nozzles 15 with shapes other than those shown in these examples. In that case, the correction amount is calculated using a formula appropriate for the processing nozzle 15 being used.

[0139] The configuration of the laser processing apparatus 10 according to the third embodiment is the same as that described in FIG. 9 for the first embodiment. However, as described above, in the third embodiment, the laser processing apparatus 10 has a plurality of processing nozzles 15, 15a. Therefore, the nozzle information storage unit 326 stores nozzle information for the plurality of processing nozzles 15, 15a provided in the laser processing apparatus 10. In the example of FIG. 16, the nozzle information storage unit 326 stores nozzle information for a vertical processing nozzle, which associates the shape parameters of the processing nozzle 15 and the correction amount calculation formula used to calculate the gap correction amount ΔZ with the nozzle shape of the vertical processing nozzle. Also, the nozzle information storage unit 326 stores nozzle information for an inclined processing nozzle, which associates the shape parameters including the nozzle tilt angle θc of the processing nozzle 15a and the correction amount calculation formula used to calculate the gap correction amount ΔZ with the nozzle shape of the inclined processing nozzle. The nozzle information also includes nozzle selection conditions, which are conditions for selecting each of the processing nozzles 15, 15a. An example of the nozzle selection condition is the range of the inclination angle θv of the surface of the workpiece W for which each processing nozzle 15, 15a is selected. The range of the inclination angle θv of the surface of the workpiece W may be specified using the nozzle inclination angle θc, as in the example of FIG.

[0140] The laser processing method according to the third embodiment is similar to that described in FIGS. 11 and 12 of the first embodiment and that described in the second embodiment.

[0141] In addition, the gap correction amount calculation unit 328 and the machining condition correction amount calculation unit 331 refer to the nozzle selection conditions of the nozzle information to select machining nozzles 15, 15a that can be used at the inclination angle θv of the surface of the workpiece W calculated by the inclination angle calculation unit 327, and obtain nozzle information about the selected machining nozzles 15, 15a from the nozzle information storage unit 326.

[0142] Here, we will explain how to generate a machining program that changes the machining nozzle 15, 15a. When machining holes with various inclination angles are mixed, for example, it is possible to generate a machining program that first machines machining positions that can be machined with a vertical machining nozzle, then includes a machining nozzle change procedure that changes from the vertical machining nozzle to an inclined machining nozzle, and machines the remaining machining positions with the inclined machining nozzle.

[0143] In the processing nozzle change procedure, if the processing nozzle 15, 15a is replaced manually, a method can be considered in which the processing program is stopped temporarily, a waiting time is provided so that the operator can replace the processing nozzle 15, 15a, and restart the processing program. Furthermore, if the laser processing apparatus 10 has a mechanism for automatically replacing the processing nozzle 15, 15a, the processing program can be configured to move the processing head 14 to a position where the processing nozzle 15, 15a is to be replaced, issue a command to the laser processing apparatus 10 to automatically replace the processing nozzle 15, 15a, and resume processing. However, this processing nozzle change procedure does not limit the third embodiment. Furthermore, if replacing the processing nozzle 15, 15a multiple times is more efficient in terms of processing time than first processing all positions that can be processed with a single processing nozzle 15, 15a, a processing nozzle change procedure for replacing the processing nozzle 15, 15a may be included.

[0144] By using the above method, high-quality and stable laser processing is possible while avoiding contact between the processing nozzles 15, 15a and the workpiece W in laser processing that performs drilling processing at various inclination angles using a minimum number of types of processing nozzles 15, 15a.

[0145] The above-described nozzle change procedure is merely an example, and may be changed depending on the contact and machining quality of the workpiece W at the tilt angle θv. While it is possible to input all gap amounts corresponding to the nozzle tilt angle θc in advance, creating a table of gap amounts corresponding to all nozzle tilt angles θc is unrealistic. It is also conceivable to prepare tilt machining nozzles with corresponding nozzle tilt angles θc for all tilt angles θv between the machining nozzle 15, 15a and the workpiece W, but this is unrealistic in terms of workability and profitability. Considering implementation in the laser machining apparatus 10, it is desirable to calculate the gap correction amount ΔZ and the correction amount for the laser machining conditions using the method illustrated in FIG. 16.

[0146] In the third embodiment, in a laser processing apparatus 10 that switches between multiple machining nozzles 15, 15a with different shapes, a machining program generation unit 31 recognizes the shape of the machining nozzles 15, 15a, calculates a gap correction amount ΔZ for the gap between the machining nozzles 15, 15a and the workpiece W to avoid contact, generates a machining program including a machining path using the gap correction amount ΔZ, and generates corrected machining condition information. By performing laser processing using a machining program based on the machining path generated taking the gap correction amount ΔZ into account and the corrected machining condition information, contact between the machining nozzles 15, 15a and the workpiece W can be avoided while achieving higher quality laser processing than conventional methods. Furthermore, when machining holes in the shortest machining path, the type of the machined hole may differ from the previous hole. In this case, switching the machining nozzles 15, 15a is required each time. However, by using a machining path that drills holes of the same type together, the total time required to switch the machining nozzles 15, 15a can be reduced.

[0147] The laser processing apparatus 10 also includes at least one of a vertical processing nozzle having a nozzle opening surface 151 perpendicular to the central axis Cn of the processing nozzle 15, and an inclined processing nozzle having a nozzle opening surface 151 inclined at an angle other than perpendicular to the central axis Cn of the processing nozzle 15a. The gap correction amount calculation unit 328 and the processing condition correction amount calculation unit 331 select the processing nozzle 15, 15a to be used in laser processing based on the relationship between the inclination angle θv between the surface of the workpiece W and the nozzle opening surface 151 of the processing nozzle 15, 15a, and the nozzle inclination angle θc of the inclined processing nozzle. This makes it possible to select the type of processing nozzle 15, 15a to be used in laser processing, whether vertical processing or inclined processing, that can maintain the desired laser processing quality while avoiding contact between the processing nozzle 15, 15a and the workpiece W.

[0148] Furthermore, the gap correction amount calculation unit 328 calculates the gap correction amount ΔZ by referring to nozzle information that associates shape parameters with a correction amount formula for calculating the gap correction amount ΔZ for each shape of the processing nozzle 15, 15a. This makes it possible to calculate an appropriate gap correction amount ΔZ according to the inclination angle θv for each shape of the processing nozzle 15, 15a, even when multiple types of processing nozzles 15, 15a are present. As a result, it is possible to perform laser processing with the desired laser processing quality while avoiding contact between the processing nozzle 15, 15a and the workpiece W.

[0149] The control device 30 in the laser processing apparatus 10 according to the first to third embodiments can be realized, for example, by an information processing device or the like. The following describes a hardware configuration in which the control device 30 is realized by a computer system that is an information processing device. The control device 30 functions as the computer system by executing a computer program that describes the processing to be performed by the control device 30 on the computer system. FIG. 17 is a block diagram showing an example of the configuration of a computer system that realizes the control device of the laser processing apparatus according to the first to third embodiments. As shown in FIG. 17, this computer system includes a control unit 901, an input unit 902, a memory unit 903, a display unit 904, a communication unit 905, and an output unit 906, which are connected via a system bus 907.

[0150] In FIG. 17 , the control unit 901 is, for example, a processor such as a CPU (Central Processing Unit) that executes a program describing the processing of the control device 30 according to the first to third embodiments. The input unit 902 is, for example, composed of a keyboard, a mouse, etc., and is used by a user of the computer system to input various information. The memory unit 903 includes various types of memory, such as a RAM (Random Access Memory) and a ROM (Read Only Memory), and a storage device, such as a hard disk, and stores programs to be executed by the control unit 901, necessary data obtained during processing, etc. The memory unit 903 is also used as a temporary storage area for programs. The display unit 904 is, for example, composed of a display, a liquid crystal display panel, etc., and displays various screens to the user of the computer system. For example, the input unit 902 and the display unit 904 may be configured as a touch panel integrally formed with each other. The communication unit 905 is a receiver and a transmitter that perform communication processing. The output unit 906 is, for example, a printer, a speaker, etc. Note that FIG. 17 is just an example, and the configuration of the computer system is not limited to the example of FIG.

[0151] Here, an example of the operation of the computer system until the program is ready to be executed will be described. In the computer system having the above configuration, the program is installed in the storage unit 903 from, for example, a CD-ROM or DVD-ROM inserted in a CD (Compact Disc)-ROM drive or DVD (Digital Versatile Disc)-ROM drive (not shown). Then, when the program is executed, the program read from the storage unit 903 is stored in the main storage area of ​​the storage unit 903. In this state, the control unit 901 executes the process as the control device 30 of the first to third embodiments in accordance with the program stored in the storage unit 903.

[0152] In the above description, a program describing the processing in the control device 30 is provided using a CD-ROM or DVD-ROM as a recording medium, but this is not limited to this. Depending on the configuration of the computer system, the capacity of the program to be provided, etc., it is also possible to use a program provided via a transmission medium such as the Internet via the communication unit 905.

[0153] The device control unit 33, nozzle shape acquisition unit 321, workpiece shape acquisition unit 322, machining condition acquisition unit 323, gap acquisition unit 325, tilt angle calculation unit 327, gap correction amount calculation unit 328, program generation unit 329, machining condition correction amount calculation unit 331, and machining condition correction unit 332 shown in FIGS. 1 and 9 are realized by the control unit 901 shown in FIG. 17 executing the programs stored in the memory unit 903 shown in FIG. 17. The input unit 902 or communication unit 905 shown in FIG. 17 is also used to realize the nozzle shape acquisition unit 321, workpiece shape acquisition unit 322, machining condition acquisition unit 323, and gap acquisition unit 325. Furthermore, the output unit 906 shown in FIG. 17 is also used to realize the machining information output unit 333. The machining condition storage unit 324, nozzle information storage unit 326, and machining condition adjustment information storage unit 330 are realized by the storage unit 903 shown in FIG. 17.

[0154] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention. [Explanation of symbols]

[0155] 10 laser processing device, 11 table, 12 laser oscillator, 13 fiber cable, 14 processing head, 15, 15a processing nozzle, 16 processing gas supply unit, 17 gas piping, 18 axis movement control unit, 30 control device, 31 processing program generation unit, 33 device control unit, 111 jig, 141 flow path, 151 nozzle opening surface, 152 first cylindrical portion, 153 second cylindrical portion, 321 nozzle shape acquisition unit, 322 workpiece shape acquisition unit, 323 processing condition acquisition unit, 324 processing condition memory unit, 325 gap acquisition unit, 326 nozzle information memory unit, 327 inclination angle calculation unit, 328 gap correction amount calculation unit, 329 program generation unit, 330 processing condition adjustment information memory unit, 331 processing condition correction amount calculation unit, 332 processing condition correction unit, 333 processing information output unit, Cn Center axis, L laser beam, On nozzle origin, P machining point, W workpiece.

Claims

1. a laser oscillator that emits laser light; a table on which the workpiece is placed; a processing head that irradiates the workpiece with the laser light from the laser oscillator; a processing nozzle provided on the laser light emission end side of the processing head and configured to spray an assist gas onto a position where the laser light is irradiated onto the workpiece; an axis movement control unit that drives the table or the machining head in each of the directions of an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other, rotates the table or the machining head about an inclined axis in an XY plane formed by the X-axis and the Y-axis, and rotates the table or the machining head about a rotation axis parallel to the Z-axis; a control unit that controls the laser oscillator and the axial movement control unit; Equipped with The control unit an inclination angle calculation unit that calculates an inclination angle between a nozzle opening surface, which is a surface of the processing nozzle facing the workpiece, and a surface of the workpiece at a position where the workpiece is to be laser processed; a gap correction amount calculation unit that calculates a gap correction amount for correcting a set gap amount between the nozzle opening surface and the surface of the workpiece using the inclination angle and shape data of the processing nozzle; a processing condition correction amount calculation unit that calculates a correction amount of the laser processing condition corresponding to the gap correction amount using processing condition adjustment information that indicates the relationship between the change amount of the gap amount and the correction amount of the laser processing condition; a processing condition correction unit that corrects the laser processing conditions using the correction amount of the laser processing conditions; a device control unit that controls the axis movement control unit so that the gap amount after correction becomes the sum of the set gap amount and the gap correction amount; A laser processing device comprising:

2. 2. The laser processing device according to claim 1, wherein the laser processing conditions are at least one of the focal position, output, pulse width, pulse period, frequency, duty, and gas pressure of the assist gas of the laser light.

3. 3. The laser processing device according to claim 2, wherein the processing condition correction amount calculation unit, when adjusting the focal position of the laser light, sets the correction amount of the focal position to a value equal to the gap correction amount.

4. 2. The laser processing device according to claim 1, wherein the gap correction amount calculation unit calculates the gap correction amount using a radius in a direction perpendicular to the central axis of the processing nozzle, an inclination angle of the nozzle opening surface with respect to the XY plane, and an inclination angle between the surface of the workpiece and the nozzle opening surface.

5. 2. The laser processing apparatus according to claim 1, wherein the inclination angle calculation unit calculates the inclination angle from the shape of the processing position of the workpiece using shape data of the processing nozzle and a three-dimensional model showing the shape of the workpiece processed into a desired shape.

6. The control unit further includes a program generation unit that generates a processing path for performing laser processing using a three-dimensional model that indicates the shape of the workpiece processed into a desired shape, and generates a processing program including the processing path; 2. The laser processing device according to claim 1, wherein the program generating unit uses the gap correction amount to correct the gap amount at a position in the processing program where the laser processing is performed.

7. 2. The laser processing apparatus according to claim 1, wherein the processing nozzle is a vertical processing nozzle having a nozzle opening surface perpendicular to a central axis of the processing nozzle, or an inclined processing nozzle having a nozzle opening surface inclined at an angle other than perpendicular to the central axis.

8. A plurality of the processing nozzles is provided, 8. The laser processing device according to claim 1, wherein, when the processing nozzle is changed, the gap correction amount calculation unit calculates the gap correction amount by referring to nozzle information that associates shape parameters for each shape of the processing nozzle with a correction amount calculation formula for calculating the gap correction amount.

9. The processing nozzle includes a vertical processing nozzle having the nozzle opening surface perpendicular to a central axis of the processing nozzle, and an inclined processing nozzle having the nozzle opening surface inclined at a nozzle inclination angle that is an angle other than perpendicular to the central axis, 9. The laser processing device according to claim 8, wherein the gap correction amount calculation unit and the processing condition correction amount calculation unit select the processing nozzle to be used in laser processing according to the relationship between the inclination angle between the surface of the workpiece and the nozzle opening surface of the processing nozzle and the nozzle inclination angle of the inclined processing nozzle.

10. a laser oscillator that emits laser light; a table on which the workpiece is placed; a processing head that irradiates the workpiece with the laser light from the laser oscillator; a processing nozzle provided on the laser light emission end side of the processing head and configured to spray an assist gas onto a position where the laser light is irradiated onto the workpiece; an axis movement control unit that drives the table or the machining head in each of the directions of an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other, rotates the table or the machining head about an inclined axis in an XY plane formed by the X-axis and the Y-axis, and rotates the table or the machining head about a rotation axis parallel to the Z-axis; a control unit that controls the laser oscillator and the axial movement control unit; A laser processing method using a laser processing apparatus comprising: An inclination angle calculation step in which the control unit calculates an inclination angle between a nozzle opening surface, which is a surface of the processing nozzle facing the workpiece, and the surface of the workpiece at a laser processing position of the workpiece; a gap correction amount calculation step in which the control unit calculates a gap correction amount for correcting a set gap amount between the nozzle opening surface and the surface of the workpiece using the inclination angle and shape data of the processing nozzle; a processing condition correction amount calculation step in which the control unit calculates a correction amount of the laser processing condition corresponding to the gap correction amount using processing condition adjustment information indicating a relationship between a change amount of the gap amount and a correction amount of the laser processing condition; a processing condition correction step in which the control unit adjusts the laser processing conditions using the correction amount of the laser processing conditions; an apparatus control step in which the control unit controls the axial movement control unit so that the gap amount after correction becomes the sum of the set gap amount and the gap correction amount; A laser processing method comprising:

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