Laser processing method, laser processing machine, program, and computer-readable medium

Abstract

The invention provides a laser processing method, a laser processing machine, a program, and a computer readable medium. The laser processing method includes: a processing step of processing a workpiece by irradiating laser light from a nozzle; and a standby step for stopping the output of the laser light. The standby step is started when the cumulative time of the processing steps that do not sandwich the standby step in the middle exceeds a predetermined threshold time.

Description

TECHNICAL FIELD

[0001] The present application relates to a laser processing method, a laser processing machine, a program, and a computer-readable medium. BACKGROUND

[0002] In laser processing, the temperature of a nozzle rises with irradiation of laser light, the nozzle thermally expands, and the distance between the nozzle and a workpiece and the electrostatic capacity change, thereby adversely affecting processing. To prevent this problem, a method of providing a flow path for circulating cooling water in the nozzle and suppressing temperature rise by circulating cooling water during processing has been proposed (for example, Patent Literature 1). As another method, a method of suppressing absorption of laser light and suppressing temperature rise by, for example, plating a metal having high reflectivity to laser light (for example, gold plating or nickel-chromium plating) on a support portion of a laser condensing lens or a lower surface thereof has been proposed (for example, Patent Literature 2).

[0003] Patent Literature 1: Japanese Realization Patent Publication No. H02-006185 Patent Literature 2: Japanese Patent No. 4812172

[0004] In recent years, the output of laser light has become higher, and even if the above-described methods are implemented, it is difficult to sufficiently suppress temperature rise of the nozzle, and it is difficult to stably perform continuous processing. SUMMARY

[0005] An object of the present disclosure is to provide a laser processing method, a laser processing machine, a program, and a computer-readable medium that can effectively cool a nozzle even if laser light is high-powered and stably perform continuous processing.

[0006] A first laser processing method of the present disclosure includes a processing step of processing a workpiece by irradiating laser light from a nozzle and a standby step of stopping output of the laser light. When the cumulative time of the processing step without the standby step in between exceeds a predetermined threshold time, the standby step is started.

[0007] According to a second aspect of the present disclosure, in the first laser processing method, the processing step includes irradiating laser light through a through-hole of the nozzle on which gold plating is applied on a surface.

[0008] According to a third aspect of the present disclosure, in the first or second laser processing method, the threshold time is determined based on the output intensity of the laser light and the proportion of the opening diameter of the tip of the nozzle to the diameter at which the output density of the laser light in the nozzle exceeds a predetermined threshold value.

[0009] According to a fourth aspect of the present disclosure, in any one of the first to third laser processing methods, the standby step is performed during a standby time corresponding to the degree to which the nozzle is heated in the processing step.

[0010] According to a fifth aspect of the present disclosure, in the laser processing method of the fourth aspect, the standby time is determined based on an output intensity of the laser, a ratio of a diameter of the tip of the nozzle at which the output density of the laser in the nozzle exceeds a predetermined threshold value, and the accumulated time.

[0011] According to a sixth aspect of the present disclosure, in the laser processing method of any one of the first aspect to the fifth aspect, the standby process further includes storing a position of the nozzle immediately after switching to the standby process as a restoration target position. The standby process further includes changing the position of the nozzle to a standby position that is apart from the restoration target position. The processing process further includes returning the position of the nozzle from the standby position to the restoration target position. In addition, it is preferable that the standby position be a position that is separated upward from the restoration target position, a position that is apart from the workpiece in a horizontal direction, or a position that is separated upward from the restoration target position and apart from the workpiece in a horizontal direction.

[0012] According to a seventh aspect of the present disclosure, in the laser processing method of the sixth aspect, the standby process further includes cooling the nozzle by a cooling device provided at the standby position.

[0013] According to an eighth aspect of the present disclosure, in the laser processing method of the sixth aspect or the seventh aspect, the processing process further includes moving the nozzle toward the restoration target position after the piercing at a restart position that is apart from the restoration target position is performed at the start of the processing process.

[0014] According to a ninth aspect of the present disclosure, in the laser processing method of the eighth aspect, the processing process further includes correcting the position of the nozzle based on a product portion existing on either one of a right side and a left side with respect to a moving direction of the nozzle. The restart position is located on the other side opposite to the one side with respect to the restoration target position.

[0015] According to a tenth aspect of the present disclosure, in the laser processing method of the ninth aspect, the one side is determined based on a code of a tool diameter correction of a processing program.

[0016] According to an eleventh aspect of the present disclosure, in the laser processing method of any one of the first aspect to the tenth aspect, the processing process includes processing the workpiece by moving the nozzle per processing unit set in a processing program. In a case where the position of the nozzle is in a switching prohibition area that is a predetermined distance or less from an end point of the processing unit when the accumulated time exceeds a threshold time, the processing process is continued until the position of the nozzle exceeds the switching prohibition area, and after the position of the nozzle exceeds the switching prohibition area, the standby process is started.

[0017] According to a twelfth aspect of the present disclosure, in the laser processing method of any one of the first aspect to the eleventh aspect, both the processing process and the standby process further include cooling the nozzle by at least one of ejecting an assist gas from the nozzle and circulating a cooling medium to a nozzle cooling circuit provided at the nozzle.

[0018] The laser processing machine of the thirteenth aspect of the present disclosure includes a control circuit configured to execute the laser processing method of any one of the first aspect to the twelfth aspect, a laser oscillator configured to output laser light, a nozzle, and a moving mechanism configured to move the nozzle.

[0019] The program of the fourteenth aspect of the present disclosure includes an instruction that, when executed by a control circuit of a laser processing machine, causes the control circuit to execute the laser processing method of any one of the first aspect to the twelfth aspect.

[0020] The computer readable medium of the fifteenth aspect of the present disclosure includes an instruction that, when executed by a control circuit of a laser processing machine, causes the control circuit to execute the laser processing method of any one of the first aspect to the twelfth aspect.

[0021] In the laser processing method of the first aspect, the laser processing machine of the thirteenth aspect including a control circuit configured to execute the laser processing method of the first aspect, the program of the fourteenth aspect including an instruction that causes the control circuit to execute the laser processing method of the first aspect, and the computer readable medium of the fifteenth aspect including an instruction that causes the control circuit to execute the laser processing method of the first aspect, since the standby process is started when the cumulative time of the processing processes sandwiching no standby process in between exceeds a predetermined threshold time, the nozzle can be cooled at a timing at which the temperature of the nozzle does not excessively rise in continuous laser processing, and stable high-precision laser processing can be achieved.

[0022] In the laser processing method of the second aspect, the laser processing machine of the thirteenth aspect including a control circuit configured to execute the laser processing method of the second aspect, the program of the fourteenth aspect including an instruction that causes the control circuit to execute the laser processing method of the second aspect, and the computer readable medium of the fifteenth aspect including an instruction that causes the control circuit to execute the laser processing method of the second aspect, oxidation of the material of the nozzle is prevented by plating. Therefore, since laser light is reflected by plating to prevent the laser light from being absorbed by the material of the nozzle, the laser output does not change even if used for a long period of time.

[0023] In the laser processing method of the third aspect, the laser processing machine of the thirteenth aspect including a control circuit configured to execute the laser processing method of the third aspect, the program of the fourteenth aspect including an instruction that causes the control circuit to execute the laser processing method of the third aspect, and the computer readable medium of the fifteenth aspect including an instruction that causes the control circuit to execute the laser processing method of the third aspect, since the amount of heat absorbed by the nozzle is determined based on the output intensity of the laser light, the ratio of the diameter of the opening hole of the tip of the nozzle to the diameter at which the output density of the laser light in the nozzle exceeds a predetermined threshold, and the rising temperature of the nozzle, the laser processing machine can be controlled to start the standby process when the temperature of the nozzle exceeds a predetermined temperature.

[0024] In the fourth type of laser processing method, the thirteenth type of laser processing machine including a control circuit configured to execute the fourth type of laser processing method, the fourteenth type of program including an instruction to cause the control circuit to execute the fourth type of laser processing method, and the fifteenth type of computer-readable medium including an instruction to cause the control circuit to execute the fourth type of laser processing method, since the nozzle is cooled during the standby time, which corresponds to the degree of heating of the nozzle in the processing step, the temperature of the nozzle is cooled to below a predetermined temperature, thus enabling long-term stable high-precision laser processing.

[0025] In the laser processing method of the fifth aspect, the laser processing machine of the thirteenth aspect including a control circuit configured to execute the laser processing method of the fifth aspect, the program of the fourteenth aspect including an instruction to cause the control circuit to execute the laser processing method of the fifth aspect, and the computer-readable medium of the fifteenth aspect including an instruction to cause the control circuit to execute the laser processing method of the fifth aspect, since the rising temperature of the nozzle is determined based on the output intensity of the laser, the ratio of the diameter of the opening at the tip of the nozzle to the diameter of the laser output density in the nozzle exceeding a predetermined threshold, and the accumulation time, the standby time can be set to the time required to cool the temperature of the nozzle to below a predetermined temperature.

[0026] In a sixth-mode laser processing method, a thirteenth-mode laser processing machine including a control circuit configured to execute the sixth-mode laser processing method, a fourteenth-mode program including instructions to cause the control circuit to execute the sixth-mode laser processing method, and a fifteenth-mode computer-readable medium including instructions to cause the control circuit to execute the sixth-mode laser processing method, by changing the nozzle position to a standby position away from the return target position during a standby process, the radiant heat generated by the workpiece heating on the nozzle can be suppressed. As a result, the nozzle cooling efficiency can be improved and the standby time shortened.

[0027] In the laser processing method of the seventh type, the laser processing machine of the thirteenth type including a control circuit configured to execute the laser processing method of the seventh type, the program of the fourteenth type including an instruction to cause the control circuit to execute the laser processing method of the seventh type, and the computer-readable medium of the fifteenth type including an instruction to cause the control circuit to execute the laser processing method of the seventh type, the standby time can be shortened by cooling the nozzle with a cooling device.

[0028] In the laser processing method of the eighth type, the laser processing machine of the thirteenth type including a control circuit configured to execute the laser processing method of the eighth type, the program of the fourteenth type including an instruction to cause the control circuit to execute the laser processing method of the eighth type, and the computer-readable medium of the fifteenth type including an instruction to cause the control circuit to execute the laser processing method of the eighth type, if processing is performed at the restoration target position at the beginning of a processing step where the laser output and the pressure of the auxiliary gas are unstable, unnecessary heat will be generated, and there is a risk of damaging the product surface. Therefore, by punching at a restart position deviating from the restoration target position and then moving the nozzle toward the restoration target position, the processing quality of the product surface can be improved.

[0029] In the laser processing method of the ninth type, the laser processing machine of the thirteenth type including a control circuit configured to execute the laser processing method of the ninth type, the program of the fourteenth type including an instruction to cause the control circuit to execute the laser processing method of the ninth type, and the computer-readable medium of the fifteenth type including an instruction to cause the control circuit to execute the laser processing method of the ninth type, the restart position can be reliably set on the outside of the product part.

[0030] In the tenth type of laser processing method, the thirteenth type of laser processing machine including a control circuit configured to execute the tenth type of laser processing method, the fourteenth type of program including an instruction to cause the control circuit to execute the tenth type of laser processing method, and the fifteenth type of computer-readable medium including an instruction to cause the control circuit to execute the tenth type of laser processing method, since the universal EIA / ISO program code is used, this laser processing method can be easily applied in a large number of processing programs.

[0031] In the eleventh type of laser processing method, the thirteenth type of laser processing machine including a control circuit configured to execute the eleventh type of laser processing method, the fourteenth type of program including instructions to cause the control circuit to execute the eleventh type of laser processing method, and the fifteenth type of computer-readable medium including instructions to cause the control circuit to execute the eleventh type of laser processing method, the switching between processing steps and standby steps can be performed by avoiding the end point of processing units that are highly likely to be near the corners of the product. Corners of the product are prone to heat accumulation; if the switching between processing steps and standby steps is performed near the corners, there is a risk of processing defects due to solder burn-through. By avoiding the portion near the end point of the processing unit when switching between processing steps and standby steps, such processing defects can be suppressed.

[0032] In the laser processing method of the twelfth aspect, the laser processing machine of the thirteenth aspect including a control circuit configured to execute the laser processing method of the twelfth aspect, the program of the fourteenth aspect including an instruction to cause the control circuit to execute the laser processing method of the twelfth aspect, and the computer-readable medium of the fifteenth aspect including an instruction to cause the control circuit to execute the laser processing method of the twelfth aspect, the temperature rise of the nozzle during processing can be suppressed by also using an auxiliary gas or a cooling medium to cool the nozzle during the processing step.

[0033] According to the technology disclosed in this application, a laser processing method, laser processing machine, program, and computer-readable medium can be provided that can effectively cool the nozzle and stably perform continuous processing. Attached Figure Description

[0034] Figure 1 This is a diagram showing the external structure of the laser processing machine according to the embodiment. Figure 2 This is a cross-sectional view of the laser head of the laser processing machine according to the embodiment. Figure 3 It is by Figure 2 The cross-sectional view cut by section line III-III'. Figure 4 This is a diagram of the internal structure of the optical fiber in the implementation method. Figure 5 An example of laser output in an embodiment is shown. Figure 6 This is a schematic diagram of a laser starting from the flashlight in the embodiment. Figure 7 This is an example of setting data. Figure 8 This is an example of a laser processing procedure. Figure 9 This is a flowchart of the laser processing method according to the first embodiment. Figure 10 This illustrates an example of the movement trajectory of the nozzle in the first embodiment as viewed from the Z direction. Figure 11 An example illustrating the movement trajectory of the nozzle in the first embodiment as viewed from the X direction. Figure 12 This is a variation of the movement trajectory of the nozzle in the first embodiment as viewed from the X direction. Figure 13 This is a flowchart of the laser processing method according to the second embodiment. Figure 14 An example of the movement trajectory of the nozzle in the second embodiment as viewed from the Z direction. Figure 15 This illustrates an example of the nozzle's movement trajectory as viewed from the Y direction in the second embodiment. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings illustrating embodiments. Furthermore, in the drawings, the same reference numerals denote corresponding or substantially identical structures. <First Implementation Method> <Structure of Laser Processing Machine 1> Figure 1 This is a simplified structural diagram showing the external structure of the laser processing machine 1 according to an embodiment of the present invention. Figure 1 The X-axis is along the depth direction of the laser processing machine 1, the Y-axis is along the width direction of the laser processing machine 1, and the Z-axis is along the height direction of the laser processing machine 1. Hereinafter, the directions along the X-axis, Y-axis, and Z-axis will be referred to as the X-direction, Y-direction, and Z-direction, respectively. Figure 1 As shown, the laser processing machine 1 includes a base 10, first guide rails 11, a column 12, second guide rails 13, a saddle 14, an oil nozzle 15, a first valve 16, a laser head 20, a laser oscillator 40, an optical fiber 45, and a numerical control apparatus 6. The laser processing machine 1 is an apparatus for processing a metal plate MP on the base 10. The metal plate MP is preferably mild steel, but it can also be SUS, aluminum steel, brass, or copper. Furthermore, the thickness of the metal plate MP is preferably 16mm to 60mm, but is not limited to this size. Alternatively, the metal plate MP can also be referred to as workpiece W. The base 10 may also include multiple elongated projections. A pair of first guide rails 11 extending along the X direction are mounted at both ends of the base 10 in the Y direction, and the column 12 is mounted on the first guide rails 11 in a manner that allows it to move freely on the first guide rails 11. The column 12 moves on the first guide rail 11 by means of the driving force of a drive device D1 such as a motor provided on either the first guide rail 11 or the column 12.

[0036] The second guide rail 13 is mounted on the column 12 along the Y-axis, which is orthogonal to the X-axis, and the saddle 14 is mounted so as to be freely movable in the Y-direction. The saddle 14 moves on the second guide rail 13, for example, by the driving force of a drive device D2, such as a motor, provided on either the second guide rail 13 or the saddle 14. Although not shown, the column 12 may also be covered by a corrugated cover. The laser head 20 is mounted on the saddle 14 so as to be freely movable in the Z-direction, which is perpendicular to the X-axis and Y-axis. The laser head 20 moves on the saddle 14, for example, by the driving force of a drive device D3, such as a motor, provided on either the saddle 14 or the laser head 20. The laser head 20 is configured as a metal plate MP on the machining base 10. The laser head 20 includes an optical system for introducing laser light sent from the laser oscillator 40. The optical system includes a collimation unit (not shown) for making the laser beam parallel. The laser head 20 includes a laser nozzle 28 for laser processing. In addition, the laser nozzle 28 can also be simply referred to as a nozzle.

[0037] The oil nozzle 15 is configured to spray oil onto the workpiece W during punching, as described later. The oil is stored in an oil tank (not shown). The first valve 16 is configured to adjust the amount of oil supplied to the oil nozzle 15 by a pump (not shown). Figure 1 In this example, the oil nozzle 15 and the first valve 16 can be mounted on the saddle 14, but they can also be mounted on the base 10. The laser oscillator 40 is configured to output a laser for machining the metal plate MP. In order to supply the laser output from the laser oscillator 40 to the laser head 20, an optical fiber 45 is retractably connected between the laser oscillator 40 and the laser head 20. The optical fiber 45 has a first end 45a for receiving the laser from the laser oscillator 40 and a second end 45b opposite to it. The CNC device 6 has a control circuit 7 that includes a hardware processor, memory, etc. The control circuit 7 is configured to execute a control program 8 and a machining program 9, and to control the laser oscillator 40, the drive devices D1 to D3, the first valve 16, and the second valve 17 and the third valve 37 (described later) to machine the metal plate MP. For example, machining program 9 is recorded using EIA / ISO program code, and control program 8 is a program that parses the program code of machining program 9 and generates control signals for controlling laser oscillator 40, drive devices D1-D3, first valve 16, and second valve 17 and third valve 37 (described later) by referring to setting data 8a. Setting data 8a records the outputs to laser oscillator 40, drive devices D1-D3, first valve 16, and second valve 17 and third valve 37 (described later) corresponding to the parameters of the code of machining program 9. Control program 8 is, for example, a program library. In the following embodiments, drive devices D1-D3 are collectively referred to as transfer mechanism TM. Transfer mechanism TM is configured to move laser nozzle 28.

[0038] Figure 2This is a cross-sectional view of the laser head 20 of the laser processing machine 1 according to the embodiment. To illustrate the optical system of the laser head 20, Figure 2 This shows a cross-sectional view of the laser head 20 cut by a section passing through the optical axis Ax3 of the laser emitted from the laser nozzle 28. (Refer to...) Figure 2 The laser head 20 has a head body 21, an upper unit 22, and a lower unit 23. The upper unit 22 is mounted on the head body 21. The upper unit 22 includes a connector 25. The connector 25 is a connector for mounting the second end 45b of the optical fiber 45 to the laser head 20.

[0039] The lower unit 23 is mounted on the head body 21. The lower unit 23 includes a lens 24 configured to face the second end 45b of the optical fiber 45, converging the laser emitted through the optical fiber 45 toward the workpiece W. That is, the laser processing machine 1 includes the lens 24. Furthermore, although in Figure 2 Although not shown, other lenses for converging light emitted from the second end 45b of the optical fiber 45 may be provided between the connector 25 and the lens 24. A laser nozzle 28 is mounted at the top of the lower unit 23. An optical path 27 for laser transmission is provided between the upper unit 22, the head body 21, the lower unit 23, and the laser nozzle 28.

[0040] like Figure 2 As shown, the laser processing machine 1 has a second valve 17 on the head body 21. The second valve 17 is configured to supply gas to the laser nozzle 28. The control circuit 7 is configured to control the second valve 17. The gas is preferably oxygen used to promote the melting of the workpiece W, but it can also be air, nitrogen, or argon. In the following embodiment, the gas supplied from the second valve 17 is referred to as auxiliary gas AG. The auxiliary gas AG is stored in a gas reservoir 18 (see reference 18). Figure 1 The gas is supplied to the laser nozzle 28 via a pump (not shown) through a gas supply channel 19. The laser nozzle 28 has a through-hole 28h through which light focused by the lens 24 and gas blown toward the workpiece W pass. Preferably, the laser nozzle 28 is made of copper. Preferably, the surface of the laser nozzle 28 where the through-hole 28h forms is plated with gold 28m. If nickel plating is applied between the gold plating 28m and the copper surface, diffusion between the copper and gold can be prevented, which is more preferred. Preferably, chromium plating is applied to the remaining surface of the laser nozzle 28. This prevents oxidation of the laser nozzle 28 and suppresses the easy absorption of laser light by the laser nozzle 28. Furthermore, since the gold plating 28m has a high reflectivity to laser light, the loss of laser energy is less, which is more preferred. Alternatively, the laser nozzle 28 can be made of a metal other than copper, or the surface of the laser nozzle 28 may not be plated.

[0041] Furthermore, referring to Figure 2The laser nozzle 28 has a tip 28e, and a through hole 28h forms an opening 28p in the tip 28e. Figure 3 It is by Figure 2 The cross-sectional view cut by section line III-III'. (See diagram below.) Figure 2 and Figure 3 As shown, the laser processing machine 1 has a third valve 37 on the head body 21. The third valve 37 is configured to adjust the amount of cooling medium supplied from the pump to the laser nozzle 28. The control circuit 7 is configured to control the third valve 37. The cooling medium is preferably external air. The cooling medium is introduced through an external air inlet (not shown) and supplied to the laser nozzle 28 via the cooling medium supply channel 38. The laser nozzle 28 has a nozzle cooling circuit 33 through which the cooling medium passes. The nozzle cooling circuit 33 includes a primary annular channel 34, a plurality of straight discharge channels 35, and a secondary annular channel 36. The cooling medium flowing in from the cooling medium supply channel 38 is supplied toward the primary annular channel 34 surrounding the through hole 28h. Subsequently, the cooling medium is supplied from the primary annular channel 34 toward the primary discharge port 35e via the discharge channels 35. The primary discharge port 35e is connected to the secondary annular channel 36, and the cooling medium is discharged from the secondary annular channel 36 via the discharge channel 36e extending radially relative to the optical axis Ax3 of the laser. That is, the cooling medium is discharged to the side of the laser nozzle 28. Furthermore, if the cooling medium is discharged approximately radially relative to the laser's optical axis Ax3, the secondary annular channel 36 and the discharge channel 36e can be omitted. For example, the discharge channel 36e can also be a recessed structure integrally located on the outer side of the secondary annular channel 36. Moreover, the shape of the nozzle cooling circuit 33 is not limited to... Figure 2 and Figure 3 The shape shown. It can also be a circulating nozzle cooling circuit as shown in Japanese Utility Model Application Publication No. 02-006185, in which case the cooling medium can also be a liquid such as cooling water.

[0042] Figure 4 This is a structural diagram of the internal structure of the optical fiber 45 according to the embodiment. The optical fiber 45 includes a transmitting portion 47 and a reflector 49. The transmitting portion 47 is cylindrical and configured to transmit laser light. The reflector 49 is a tubular member covering the outer periphery of the transmitting portion 47 and configured to reflect laser light at the interface with the transmitting portion 47. Figure 5 This illustrates an example of the laser RL's output when the optical axis Ax1 of the laser RL is aligned with the central axis Ax2 of the fiber 45. Figure 5 In the diagram of fiber 45, the right side represents the magnitude of the laser output density. Figure 5 In the diagram, it is shown that the closer the line on the coordinate graph is to the right, the greater the laser output density. Figure 5 This illustrates an example where the laser output density follows a Gaussian distribution. For example... Figure 5As shown, the laser output density is highest near the central axis Ax2 of fiber 45 and decreases gradually.

[0043] Figure 6 This is a schematic diagram of the laser RL starting from the laser nozzle 28 in the embodiment. (See diagram) Figure 6 As shown, the laser RL is most concentrated at the focal position FP, and incident on the surface of the workpiece W in a slightly expanded state. Typically, the focal position FP is set slightly outside the nozzle tip 28e. Here, the portion of the laser output density in the opening 28p of the nozzle tip 28e that exceeds a predetermined threshold is called the irradiated portion RP, and the remaining portion is called the peripheral portion PP. The diameter DCC of the irradiated portion RP can be, for example, using the value of D4σ specified by the ISO 11446 standard. D4σ determines the range exceeding the threshold of output density defined as an intensity distribution containing four times the standard deviation σ of the intensity distribution converging at the laser RL. This diameter DCC is determined by measurement using a measuring instrument or by using optical analysis software. Figure 6 In this text, the diameter of the peripheral portion PP is denoted as DBC (hereinafter referred to as the aperture diameter), but the aperture diameter DBC is determined according to the specifications of the laser nozzle 28. The peripheral portion PP surrounds the irradiated portion RP radially relative to the optical axis Ax3 of the laser RL. Additionally, as... Figure 6 As shown, the auxiliary gas AG is ejected from the laser nozzle 28 in such a manner that it reaches both the irradiated portion RP and the peripheral portion PP.

[0044] In the following implementation, the ratio of the opening diameter DBC of the nozzle tip 28e to the diameter DCC at which the output density of the laser RL in the laser nozzle 28 exceeds a predetermined threshold (defined by D4σ) is called the area occupancy rate AOR [%]. If the output intensity of the laser RL output from the laser oscillator 40 is set to P [W], and the laser output density follows a Gaussian distribution, then the heat P applied per unit time by the laser RL to the laser nozzle 28 is... H [W] is obtained as shown in Equation 1 below. P H =P×(1.82×AOR‐100) / 100 (Equation 1) This 1.82x is based on the size of the beam diameter containing 99% of the energy. Additionally, this can be applied when the laser output density follows a distribution other than a Gaussian distribution, or when other thresholds (full width at half maximum, 1 / e) are used to determine the RP of the irradiated portion. 2 In the case of width and blade width, the multiplier multiplied by the area occupancy ratio (AOR) can be determined in a way that makes the beam diameter contain more than 99% of the energy.

[0045] If we set the heating time of the laser nozzle 28 as t [seconds], the temperature of the laser nozzle 28 before heating as T0 [°C], the specific heat of the laser nozzle 28 as c [kJ / (kg·°C)], and the density of the laser nozzle 28 as ρ [kg / m³], then... 3 ], and set the volume of the laser nozzle 28 to V[m 3 The temperature T[°C] of the heated laser nozzle 28 is then calculated as shown in Equation 2. T‐T0=(P H -P OFF )×t / 0.278cρV (Equation 2) P in (Equation 2) OFF This takes into account the heat dissipation per unit time caused by convective heat dissipation from the atmosphere, cooling medium, and auxiliary gas AG. This P OFF Determined through experience.

[0046] High-precision laser processing is achieved by adjusting the distance LW between the nozzle tip 28e and the workpiece W. The control circuit 7 controls the capacitance between the nozzle tip 28e and the workpiece W using a method as described in US Patent Publication No. 2004-159643, thereby adjusting the distance LW. If the laser nozzle 28 expands due to heat from the laser RL, the relationship between the distance LW and the aforementioned capacitance changes. Therefore, if heating of the laser nozzle 28 by the laser RL is suppressed, processing can be performed with stable precision even during prolonged laser processing.

[0047] Figure 7 This is an example of setting data 8a. Setting data 8a sets the output intensity P of laser RL for each combination of workpiece W's material, workpiece W's thickness, and assist gas AG, in the case of punching. P [W] Output intensity P of laser RL in laser cutting case R [W]. This combination is set, for example, in the EIA / ISO program format by calling the M622 code. Figure 7 As shown, the output intensity P of laser RL in the case of punching is... P [W] Output intensity P of laser RL in laser cutting case R [W] can also be set to multiple levels. These levels are called cutting conditions. Figure 7 This represents an example of setting 10 cutting conditions.

[0048] Figure 8 This is an example of laser processing procedure 9. Figure 9 This is a flowchart of the laser processing method according to the first embodiment. Figure 10 An example illustrating the movement trajectory of the laser nozzle 28 in the first embodiment. Figure 8In the middle, for easy reference, "line number:" is added to the left of machining program 9. The control circuit 7 that executes the control program 8 that parses machining program 9 performs the following processing. That is, the control circuit 7 is configured to execute the laser processing method of the embodiment. Line number 1 indicates the start of the program, and line number 2 indicates the program number. The control circuit 7 that executes control program 8 reads the setting of the workpiece W as mild steel and the thickness of workpiece W as 25.0 mm and the auxiliary gas AG as oxygen from the M622 code through the code of line number 3, and selects the corresponding setting data 8a. The control circuit 7 that executes control program 8 performs initial settings such as coordinate determination through the codes of lines 4 to 6. In Figure 8 In step ST1, the control circuit 7 executing control program 8 starts the laser oscillator 40 during the execution of line number 7. Specifically, the control circuit 7 executing control program 8 controls the laser oscillator 40 to an intensity P specified by the cutting condition S1 of code G600. P 1[W] is punched. At this time, the control circuit 7 executing the control program 8 sprays oil from the first valve 16 toward the workpiece W. Then, the control circuit 7 executing the control program 8 opens the second valve 17 and the third valve 37, and starts cooling the laser nozzle 28 by spraying auxiliary gas AG from the laser nozzle 28 and circulating the cooling medium into the nozzle cooling circuit 33 provided on the laser nozzle 28.

[0049] The control circuit 7 executing control program 8 sets the laser cutting conditions using the code at line number 8. Simultaneously, in step ST2, the control circuit 7 executing control program 8 sets the threshold time t. th The cutting condition parameters are omitted in line 8 of the G602 code. In this case, the cutting condition S1 of the G600 code is inherited, and the control circuit 7 of the control program 8 calculates the strength P specified by the cutting condition S1 of the G602 code from the set data 8a. R 1[W], control the laser oscillator 40 so as to achieve intensity P R 1. [W] Perform cutting processing. Read in the output intensity P of laser RL. R 1[W] and the temperature T of the laser nozzle 28 that should begin to cool. th The temperature T of the laser nozzle 28, which should begin cooling, should be adjusted. th The preset values ​​are stored in the memory of the control circuit 7. Furthermore, since the area occupancy rate AOR[%] is pre-calculated using the opening diameter DBC of the nozzle tip 28e and the diameter DCC pre-calculated by the measuring instrument and optical analysis software, the control circuit 7 executing the control program 8 can calculate the heat P applied to the laser nozzle 28 per unit time using (Equation 1). H [W]. If the temperature of the laser nozzle 28, which should begin cooling, is set to T... thThen, the control circuit 7 executing control program 8 can calculate the threshold time t using the following (Equation 3). th . t th =0.278cρV(T) th -T0) / (P H -P OFF (Equation 3) The T th This value is obtained by subtracting a certain deviation from the temperature at which the capacitance may change due to deformation of the laser nozzle 28 caused by heating. From Equation 3, it can be seen that the threshold time t is determined based on the output intensity P of the laser RL and the ratio (area occupancy ratio AOR) of the opening diameter DBC of the tip 28e of the laser nozzle 28 to the diameter DCC at which the output density of the laser RL in the laser nozzle 28 exceeds a predetermined threshold. th .

[0050] In step ST3, the control circuit 7 of the execution control program 8 executes the machining process of machining workpiece W by irradiating laser RL from laser nozzle 28. Specifically, the control circuit 7 of the execution control program 8 corrects the tool diameter using the code in line number 9, causing the laser nozzle 28 to move towards the position (-0.1, 0, 0). The control circuit 7 of the execution control program 8 moves the laser nozzle 28 using the codes in lines 10 to 13. That is, the machining process includes irradiating laser RL through the through hole 28h of the laser nozzle 28, whose surface is coated with gold 28m. In addition, since the second valve 17 and the third valve 37 are already open, the machining process also includes cooling the laser nozzle 28 by injecting auxiliary gas AG from the laser nozzle 28 and circulating cooling medium into the nozzle cooling circuit 33 provided on the laser nozzle 28. Alternatively, the injection of auxiliary gas AG and the circulation of cooling medium into the nozzle cooling circuit 33 can be omitted in the machining process. During the execution of the machining process, the control circuit 7 of the execution control program 8 measures the cumulative time t of the machining process. acm Furthermore, the processing performed by moving the laser nozzle 28 by a single command in this embodiment and the following embodiments is referred to as a processing unit. In the case of a processing program described in EIA / ISO program format such as processing program 9, since a command is determined on a unit of one line, each line determines a processing unit. That is, the processing step includes processing the workpiece W by moving the laser nozzle 28 according to each processing unit set in processing program 9.

[0051] In step ST4, the control circuit 7 executing control program 8 determines whether the processing step has ended. If the processing step has not ended ("No" in step ST4), proceed to step ST5. In step ST5, the control circuit 7 executing control program 8 determines the cumulative time t of the processing steps that do not include the standby steps described later.acm Has the predetermined threshold time t been exceeded? th If the cumulative time t acm No more than the predetermined threshold time t th If "No" is selected in step ST5, then return to step ST3. If the accumulated time t acm Time t exceeding the predetermined threshold th If "Yes" is selected in step ST5, then in step ST6, the control circuit 7 executing control program 8 begins the standby process to stop the output of laser RL. That is, the cumulative time t of the processing steps without any intermediate standby processes. acm Time t exceeding the predetermined threshold th At this time, the standby process begins. Since the third valve 37 is not closed during the standby process, the standby process also includes cooling the laser nozzle 28 by circulating cooling medium into the nozzle cooling circuit 33 provided on the laser nozzle 28. In addition, auxiliary gas AG may be further injected during the standby process. By injecting auxiliary gas AG during the standby process, air is prevented from mixing into the piping, which reduces the possibility of poor processing caused by deterioration of oxygen purity when processing resumes. Furthermore, cooling medium may not be circulated into the nozzle cooling circuit 33 during the standby process. In step ST6, the control circuit 7 executing the control program 8 also stops the movement of the laser nozzle 28.

[0052] Figure 10 An example showing the movement trajectory of the laser nozzle 28 in the first embodiment as viewed from the Z direction. Figure 11 This illustrates an example of the movement trajectory of the laser nozzle 28 in the first embodiment, as viewed from the X direction. Figure 10 and Figure 11 In the text, R_<row number> represents the row number. Figure 8 The program code lines numbered to indicate the nozzle movement path. Figure 10 In this context, the initial position of the laser nozzle 28 shown in row number 9 is set to P_ST, and the position of the laser nozzle 28 at the start of the standby process is set to P_RT. Figure 10 , Figure 11 The example shows an instance where the standby process begins during the execution of the code shown in line 11, but the standby process can also begin during the execution of any of the codes in lines 10 to 13.

[0053] Following step ST6, in step ST7, the control circuit 7 executing control program 8 stores the position (stop position) of the laser nozzle 28 after switching to the standby process as the restoration target position P_RT. The standby process also includes storing the position (stop position) of the laser nozzle 28 after switching to the standby process as the restoration target position P_RT. In step ST8, the control circuit 7 executing control program 8 sets the standby time t to specify the duration of the standby process. sus The standby time t sus Based on (Equation 3) and the following (Equation 4), it is obtained. t sus = (T het -T0)×0.278cρV / P OFF (Equation 4) Here, T het This is the temperature corresponding to the degree to which the laser nozzle 28 is heated during the processing step. In this embodiment, T het With T th They are equal. Therefore, if we use (Equation 2), then (Equation 4) can be expressed as follows (Equation 5). t sus ≈ (P) H -P OFF )×t acm / P OFF (Equation 5) From Equation 5, it can be seen that the ratio of the output intensity P of the laser RL, the opening diameter DBC of the tip 28e of the laser nozzle 28 to the diameter DCC where the output density of the laser RL in the laser nozzle 28 exceeds a predetermined threshold (area occupancy ratio AOR), and the cumulative time t are all factors that determine the laser RL's output intensity P. acm To determine the standby time t sus Additionally, in this embodiment, the cumulative time t acm With threshold time t th Roughly equal.

[0054] In step ST9, as Figure 11 As shown, the control circuit 7 executing control program 8 changes the position of the laser nozzle 28 to a standby position P_SB, which is away from the target position P_RT. That is, the standby process also includes changing the position of the laser nozzle 28 to the standby position P_SB, which is away from the target position P_RT. Figure 11 In the example, the standby position P_SB is a position offset from the target position P_RT along the Z direction by a height H in the direction away from the workpiece W. This height H is sufficient to suppress the laser nozzle 28 from the radiant heat generated by the heating of the workpiece W.

[0055] In step ST10, the control circuit 7 executing control program 8 determines the elapsed time t from the start of the standby process. elp Has the standby time t been reached? sus That's all. If the elapsed time t from the start of the standby process... elp Less than standby time t sus (If "No" is selected in step ST10), then repeat step ST10. If the elapsed time t from the start of the standby process... elp Standby time t sus If the above is true ("Yes" in step ST10), then in step ST11, the control circuit 7 executing control program 8 restarts the processing step. Therefore, during the standby time t... sus The standby process is performed during the period t. sus This corresponds to the degree to which the laser nozzle 28 is heated during the machining process. Subsequently, in step ST11, the control circuit 7 executing control program 8 moves the laser nozzle 28 towards the target recovery position P_RT. That is, the machining process also includes returning the position of the laser nozzle 28 from the standby position P_SB to the target recovery position P_RT. Preferably, after moving to the target recovery position P_RT, the control circuit 7 executing control program 8 opens the first valve 16 to spray oil onto the workpiece W. At this time, in step ST12, the control circuit 7 executing control program 8 restarts the laser oscillator 40 to perform punching. At this time, it is preferable to set the cutting conditions to S1 based on the previous G600 code and perform punching. After step ST12 is completed, the process returns to step ST3.

[0056] Subsequently, in step ST3, the control circuit 7 of control program 8 executes the remaining machining operations. At this time, it is preferable to set the cutting conditions to S1 based on the previous G602 code and perform the machining operation. During the accumulated time t... acm Time exceeding the threshold t th If the previous processing step has been completed ("Yes" in step ST4), the laser processing method of this embodiment ends. This can be because the control circuit 7 executing the control program 8 determines that the processing step has ended when it recognizes the code indicating that the laser irradiation has been interrupted in line number 14. <Features and effects of the laser processing method in this embodiment> Since the laser processing method of the first embodiment, including the control program 8 that causes the control circuit 7 to execute the instruction of the laser processing method, and the laser processing machine 1 are configured such that if the cumulative time t of the processing steps is... acm Time exceeding the threshold t th Then it moves to the standby process, so it can effectively cool the laser nozzle 28 and stably carry out continuous processing. <Modifications of the First Embodiment> In the above embodiment, the standby position P_SB is a position offset from the restoration target position P_RT by a height H in the direction away from the workpiece W, but it can also be other positions. Furthermore, a cooling device 30 for cooling the laser nozzle 28 can be additionally provided at the standby position P_SB. Figure 12 This is a modified example showing the movement trajectory of the laser nozzle 28 in the first embodiment as viewed from the X direction. (See reference...) Figure 12 The standby position P_SB is a position that is still offset in the Y direction relative to the target position P_RT. The cooling device 30 includes an insertion port 31 for inserting the laser nozzle 28 and a cooling medium supply channel 32 for supplying cooling medium to the insertion port 31. When the laser nozzle 28 is cooled by the cooling device 30 during the standby process, the denominator P of (Equation 5) can be increased. OFF The value of t is so that the standby time t can be shortened. sus Therefore, the overall processing time can be shortened and processing efficiency improved. <Second Implementation Method> In the first embodiment, punching is performed at the target position P_RT and laser processing is restarted. However, since the output of the laser and the output of the auxiliary gas AG are unstable at the start of laser processing, punching is performed at a restart position P_RS, which is deviated from the target position P_RT, and laser processing is restarted. This is more preferable in terms of improving processing quality. The laser processing method of the second embodiment includes a method for moving the laser nozzle 28. Figure 13 This is a flowchart of the laser processing method according to the second embodiment. Figure 14 An example showing the movement trajectory of the laser nozzle 28 in the second embodiment as viewed from the Z direction. Figure 15 This shows an example of the movement trajectory of the laser nozzle 28 in the second embodiment as viewed from the Y direction.

[0057] exist Figure 13In this embodiment, the same reference numerals are used in the same process as in the first embodiment, and descriptions are omitted. After step ST2, in step ST21, the control circuit 7 executing the control program 8 sets the tool diameter correction using the code in line number 9. The code G41 is described in line number 9. It indicates that a correction should be made to shift the nozzle tip 28e to the left in the direction of movement of the laser nozzle 28. Alternatively, if the code G42 is described in the machining program 9, it indicates that a correction should be made to shift the nozzle tip 28e to the right in the direction of travel of the laser nozzle 28. In step ST3A, the control circuit 7 executing the control program 8 performs the tool diameter correction process set in step ST21, in addition to the process in step ST3. That is, the machining process includes correcting the position of the laser nozzle 28 based on whether a product portion exists on either the right or left side of the direction of movement of the laser nozzle 28. This side is determined based on the tool diameter correction code (code G41 or code G42) in the machining program 9.

[0058] If the cumulative time t acm The predetermined threshold time t has not been exceeded th If "No" is selected in step ST5, then the control circuit 7 executing control program 8 returns to step ST21 and executes step ST21 again. If the accumulated time t acm Time t exceeding the predetermined threshold th (If "Yes" is selected in step ST5), then in step ST22, the control circuit 7 executing control program 8 determines whether the position of the laser nozzle 28 is within the switching prohibition zone SPR, which is less than a predetermined distance from the endpoint of the processing unit. The endpoint of the processing unit includes both the start point and the end point of the processing unit. Figure 14 In the diagram, the switching forbidden zone (SPR) is represented by the area enclosed by a dashed line. The switching forbidden zone (SPR) is located near the corners of the product and is prone to heat accumulation. Therefore, if the process is paused in the switching forbidden zone (SPR) and then restarted, the likelihood of processing defects is high. Therefore, the control circuit 7 executing control program 8 does not pause when the laser nozzle 28 is in the switching forbidden zone (SPR), but continues laser processing.

[0059] Therefore, when the laser nozzle 28 is in the switching prohibition zone SPR, which is less than a predetermined distance from the end point of the processing unit ("Yes" in step ST22), the control circuit 7 executing the control program 8 returns to step ST21 and executes step ST21 again. When the laser nozzle 28 is not in the switching prohibition zone SPR, which is less than a predetermined distance from the end point of the processing unit ("No" in step ST22), the control circuit 7 executing the control program 8 executes step ST6. That is, in the laser processing method of this embodiment, during the accumulated time t... acm Time exceeding the threshold tth When the position of the laser nozzle 28 is in the switching prohibition zone SPR, which is below a predetermined distance from the end point of the processing unit, the processing operation continues until the position of the laser nozzle 28 exceeds the switching prohibition zone SPR. After the position of the laser nozzle 28 exceeds the switching prohibition zone SPR, the standby operation begins.

[0060] Following step ST6, in step ST7A, in addition to the processing in step ST7, the restart position P_RS is determined. This restart position P_RS is located on the opposite side from the target position P_RT. That is, when the tool diameter correction code is G41, the control circuit 7 executing the control program 8 sets the restart position P_RS to the left of the target position P_RT relative to the direction of movement of the laser nozzle 28. When the tool diameter correction code is G42, the control circuit 7 executing the control program 8 sets the restart position P_RS to the right of the target position P_RT relative to the direction of movement of the laser nozzle 28. The distance between the restart position P_RS and the target position P_RT is set empirically to a value that results in good machining accuracy.

[0061] Subsequently, in step ST8A, the control circuit 7 executing control program 8 sets the standby time t based on (Equation 5). sus In the first embodiment, the cumulative time t acm Considered as the threshold time t th They are equal, but in this embodiment, the cumulative time t acm Sometimes more than the threshold time t th Longer. This standby time t sus Based on the cumulative time t acm The length is set. In step ST9A, the control circuit 7 executing the control program 8 changes the position of the laser nozzle 28 to the standby position P_SB, which is determined based on the restart position P_RS. Figure 15 This indicates the standby position P_SB in this embodiment. This standby position P_SB is a position offset from the restart position P_RS along the Z direction with a height H in the direction away from the workpiece W. Alternatively, in the second embodiment, the standby position P_SB may be the same as in the first embodiment.

[0062] If the elapsed time t from the start of the standby process elp Reaching standby time t susIf the above is true ("Yes" in step ST10), then in step ST23, the control circuit 7 executing control program 8 restarts the machining process. Specifically, the control circuit 7 executing control program 8 moves the laser nozzle 28 to the restart position P_RS. Preferably, after moving to the restart position P_RS, the control circuit 7 executing control program 8 causes the first valve 16 to spray oil onto the workpiece W. Subsequently, in step ST12, the control circuit 7 executing control program 8 restarts the laser oscillator 40 for punching. At this time, it is preferable to set the cutting condition to S1 based on the previous G600 code and perform punching. In step ST24, the control circuit 7 executing control program 8 moves the laser nozzle 28 to the restoration target position P_RT while irradiating the laser RL. That is, the machining process also includes moving the laser nozzle 28 to the restoration target position P_RT after punching at the restart position P_RS, which is away from the restoration target position P_RT, at the beginning of the machining process. At this point, it is preferable to set the cutting condition to S1 based on the previous G602 code, and move the laser nozzle 28 toward the restoration target position P_RT while irradiating the laser RL. After step ST24 is completed, the control circuit 7 executing the control program 8 returns to step ST21 and executes step ST21 again. <Features and effects of the laser processing method in this embodiment> The laser processing method of the second embodiment includes a control program 8 that causes the control circuit 7 to execute instructions for the laser processing method, and a laser processing machine 1 that punches a hole at a restart position P_RS, slightly deviating from the original target position P_RT, and restarts laser processing. Therefore, since processing is performed using a stable laser RL, the processing quality can be improved. <Variations in the full implementation> Alternatively, in the first embodiment, step ST22 can be added and replaced by step ST8, performing step ST8A of the second embodiment. Furthermore, in the second embodiment, step ST22 can be deleted and replaced by step ST8A, performing step ST8 of the first embodiment. Additionally, while examples of changing cutting conditions via G603 code are not shown in the above embodiments, if the intensity P of the laser RL is changed midway through the machining process via G603 code, step ST2 can be executed at that time, and the threshold time t can be recalculated based on the changed intensity P. th .

[0063] In the above embodiment, an example is illustrated where setting data 8a is set according to each combination of the material of workpiece W, the thickness of workpiece W, and the auxiliary gas AG. The corresponding setting data 8a is selected by setting the combination of the material of workpiece W, the thickness of workpiece W, and the auxiliary gas AG as parameters of the M622 code. However, it is also possible to select the corresponding setting data 8a by preparing the setting data 8a in a manner distinguishable by any identifier, so that the parameters of the M622 code include that identifier. Figure 7 The combination of cutting conditions is shown. Furthermore, a laser processing machine 1 for processing metal sheets (MP) is given, but it can also be applied to laser processing machines for processing tubes, etc. In this case, the laser head 20 can also rotate around rotation axes parallel to the X and Y axes respectively, so that three-dimensional processing can be performed. Furthermore, the laser of the laser processing machine 1 of this application may not be high-power.

[0064] Some or all of the functions of the aforementioned control program 8 can also be implemented by a dedicated processor or integrated circuit. The aforementioned control program 8 is not limited to being stored in the memory built into the control circuit 7, but can also be stored on floppy disks, optical disks, CD-ROMs, and magnetic disks, as well as storage media that can be removed from and read by the computer such as the CNC device 6, such as SD cards, USB storage devices, and external hard drives.

[0065] In this application, "comprising" and its derivatives are non-restrictive terms describing the existence of a constituent element, without excluding the existence of other constituent elements not described. This also applies to "having," "including," and their derivatives.

[0066] Terms like “~component,” “~part,” “~element,” “~body,” and “~structure” can have multiple meanings, such as a single part or multiple parts.

[0067] Ordinal numbers such as "first" and "second" are merely terms used to identify structures and do not have any other meaning (such as a specific order). For example, the existence of a "first element" does not imply the existence of a "second element," nor does the existence of a "second element" imply the existence of a "first element."

[0068] Unless otherwise specified in the implementation, terms such as “substantially,” “about,” and “approximately” indicating degree may refer to a reasonable deviation from the final result without significant change. All numerical values ​​described in this application may be interpreted as including terms such as “substantially,” “about,” and “approximately.”

[0069] In this application, phrases such as "at least one of A and B" should be interpreted as including only A, only B, or both A and B.

[0070] Based on the above disclosure, it is obvious that various modifications and alterations can be made to this invention. Therefore, this invention can also be implemented in ways different from the specific disclosure of this application without departing from the spirit of the invention.

Claims

1. A laser processing method, comprising: a processing step of processing a workpiece by irradiating a laser from a nozzle; and a standby step of stopping output of the laser, wherein the standby step is started when a cumulative time of the processing step without interposing the standby step exceeds a predetermined threshold time.

2. The laser processing method according to claim 1, wherein the processing step includes irradiating the laser through a through-hole of the nozzle on which gold plating is applied on a surface.

3. The laser processing method according to claim 1 or 2, wherein the threshold time is determined based on an output intensity of the laser, and a ratio of an opening diameter of a tip of the nozzle to a diameter at which an output density of the laser in the nozzle exceeds a predetermined threshold.

4. The laser processing method according to any one of claims 1 to 3, wherein the standby step is performed during a standby time corresponding to a degree to which the nozzle is heated in the processing step.

5. The laser processing method according to claim 4, wherein the standby time is determined based on the output intensity of the laser, the ratio of the opening diameter of the tip of the nozzle to the diameter at which the output density of the laser in the nozzle exceeds the predetermined threshold, and the cumulative time.

6. The laser processing method according to any one of claims 1 to 5, wherein the standby step further includes storing a position of the nozzle immediately after switching to the standby step as a restoration target position, the standby step further includes changing the position of the nozzle to a standby position away from the restoration target position, and the processing step further includes returning the position of the nozzle from the standby position to the restoration target position.

7. The laser processing method according to claim 6, wherein the standby step further includes cooling the nozzle by a cooling device provided at the standby position.

8. The laser processing method according to claim 6 or 7, wherein the processing step further includes moving the nozzle toward the restoration target position after piercing at a restart position deviated from the restoration target position at the start of the processing step.

9. The laser processing method according to claim 8, wherein the processing step further includes correcting the position of the nozzle based on a product portion existing on either one of right and left sides with respect to a moving direction of the nozzle, and the restart position is located on the other side opposite to the one side with respect to the restoration target position.

10. The laser processing method according to claim 9, wherein the one side is determined based on a code of a tool diameter correction of a processing program.

11. The laser processing method according to any one of claims 1 to 10, wherein the processing step includes processing the workpiece by moving the nozzle per processing unit set in a processing program.

12. The laser processing method according to any one of claims 1 to 11, wherein the processing step includes processing the workpiece by moving the nozzle per processing unit set in a processing program, and the standby step includes changing the position of the nozzle to the standby position away from the restoration target position, and returning the position of the nozzle from the standby position to the restoration target position.

13. The laser processing method according to any one of claims 1 to 12, wherein the processing step includes processing the workpiece by moving the nozzle per processing unit set in a processing program, and the standby step includes changing the position of the nozzle to the standby position away from the restoration target position, and returning the position of the nozzle from the standby position to the restoration target position.

14. The laser processing method according to any one of claims 1 to 13, wherein the processing step includes processing the workpiece by moving the nozzle per processing unit set in a processing program, and the standby step includes changing the position of the nozzle to the standby position away from the restoration target position, and returning the position of the nozzle from the standby position to the restoration target position.

15. The laser processing method according to any one of claims 1 to 14, wherein the processing step includes processing the workpiece by moving the nozzle per processing unit set in a processing program, and the standby step includes changing the position of the nozzle to the standby position away from the restoration target position, and returning the position of the nozzle from the standby position to the restoration target position. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In a case where the position of the nozzle is in a switch prohibition area that is a predetermined distance or less from an end point of the processing unit when the accumulated time exceeds the threshold time, the processing process is continued until the position of the nozzle exceeds the switch prohibition area, and after the position of the nozzle exceeds the switch prohibition area, the standby process is started.

12. The laser processing method according to any one of claims 1 to 11, wherein The processing process and the standby process each further include cooling the nozzle by at least one of ejecting an assist gas from the nozzle and circulating a cooling medium to a nozzle cooling circuit provided to the nozzle.

13. A laser processing machine, comprising: a control circuit configured to execute the laser processing method according to any one of claims 1 to 12; a laser oscillator configured to output the laser; the nozzle; and a moving mechanism configured to move the nozzle.

14. A program comprising instructions that, when executed by a control circuit of a laser processing machine, cause the control circuit to execute the laser processing method according to any one of claims 1 to 12.

15. A computer-readable medium comprising instructions that, when executed by a control circuit of a laser processing machine, cause the control circuit to execute the laser processing method according to any one of claims 1 to 12. ​

Images