Laser processing system and laser processing process

Abstract

Laser processing system (110), comprising: a nozzle (24) with an ejection opening (28) which ejects a jet of an auxiliary gas along the optical axis (O) of the laser light, wherein the nozzle (24) forms a point of maximum velocity of the jet at a position remote from the ejection opening (28); a measuring instrument (66, 76) that measures one thing from the speed of the jet and a noise produced by the jet impacting a workpiece; and an anomaly detection unit (113) which determines whether the output data of the measuring instrument (66, 76) differ from reference data or not, wherein the reference data, as information representing a position of the maximum point of the velocity, indicate a peak value of the output data which is continuously measured by the measuring instrument (66, 76) along the jet ejected by the nozzle (24) in a normal state.

Description

Background of the invention 1. Field of the invention

[0001] The present invention relates to a laser processing system and a laser processing method. 2. Description of the state of the art

[0002] Laser processing systems with a nozzle that ejects an auxiliary gas during processing of a workpiece with laser light in order to blow away the material of the workpiece melted by the laser light are known (see, for example, Patent Application Laid-Open No. JP 2017-051 965 A).

[0003] Other similar systems are known, for example, from JP 2000-210 768 A, JP H05-77 073 A, JP 2014-113 597 A, JP H05-305 475 A or GB 2 165 789 A.

[0004] When processing a workpiece, there is a possibility of a nozzle blockage or an anomaly in the operation of the auxiliary gas supply device (for example, a gas shortage). If such an anomaly occurs, the velocity of the auxiliary gas jet expelled from the nozzle decreases, which impairs the laser processing. A technique that allows for the reliable detection of such anomalies is currently needed. Brief description of the invention

[0005] According to one aspect of the present invention, a laser processing system comprises a nozzle with an ejection orifice that emits a jet of an auxiliary gas along the optical axis of the laser light, wherein the nozzle forms a point of maximum jet velocity at a position remote from the ejection orifice; a measuring instrument that measures a product of the jet velocity and a noise generated by the jet impacting a workpiece; and an anomaly detection unit that determines whether the output data of the measuring instrument differs from reference data or not, wherein the reference data, as information representing a position of the point of maximum velocity, indicate a peak value of the output data that is continuously measured by the measuring instrument (66, 76) along the jet emitted by the nozzle (24) in a normal state.

[0006] In a further aspect of the present invention, a laser processing system comprises a nozzle with an ejection orifice that ejects a jet of an auxiliary gas along the optical axis of the laser light, wherein the nozzle forms a point of maximum jet velocity at a position remote from the ejection orifice; a measuring instrument that measures a product of the jet velocity and a noise generated by the jet impacting a workpiece; an anomaly detection unit that determines whether the output data of the measuring instrument differs from reference data or not, wherein the anomaly detection unit determines whether the output data has entered a range defined on the basis of the reference data after the nozzle and the workpiece have been moved relative to each other, and determines that the output data differs from the reference data if the output data lies outside the range;a position acquisition unit that acquires information indicating the position of the maximum point based on the output data; a movement mechanism that moves the nozzle and the workpiece relative to each other; a movement control unit that controls the movement mechanism and positions the nozzle at a target position determined based on the information with respect to a machining location of the workpiece, the movement control unit performing feedback control of the movement mechanism according to the target position, the abnormality determination unit determining, after executing the feedback control, whether the output data measured by the measuring instrument has entered the range or not;and a pressure regulating unit that changes the supply pressure of the auxiliary gas to the nozzle when the anomaly detection unit determines that the output data are outside the range, wherein, after a change in the supply pressure by the pressure regulating unit, the anomaly detection unit again determines whether the output data measured by the measuring instrument have entered the range or not.

[0007] According to a further aspect of the present invention, in a method for laser processing of a workpiece using the laser processing system described above, information indicating the position of a maximum point is obtained based on the input data; in a state in which the nozzle has been arranged at a target position determined on the basis of the information with respect to a processing point, a beam is emitted from the ejection opening of the nozzle and the workpiece is processed by laser light; and it is determined whether the input data differs from reference data or not.

[0008] An operator can detect whether an anomaly has occurred in the nozzle or the auxiliary gas supply device and quickly replace the nozzle or take action against the operational anomaly (for example, a gas shortage in) the auxiliary gas supply device. Simple explanation of the drawings Fig. Figure 1 is a view of a laser processing system. Fig. Figure 2 is an image for which the jet of auxiliary gas ejected from a nozzle was recorded with a high-speed camera. Fig. Figure 3 is a view to explain the maximum point of the jet velocity, where the upper diagram schematically shows the relationship between the jet velocity and a position x from the ejection aperture, and the lower part of the diagram shows the representation of Fig. 2 is shown. Fig. Figure 4 shows a view of a beam monitoring device. Fig. 5 is a block diagram of the in Fig. Beam monitoring device shown in 4. Fig. Figure 6 shows a view of another beam monitoring device. Fig. 7 is a block diagram of the in Fig. Beam monitoring device shown in Figure 6. Fig. 8 is a view of yet another beam monitoring device. Fig. 9 is a block diagram that is in Fig. Beam monitoring device shown in section 8. Fig. 10 is a view of another laser processing system. Fig. 11 is a block diagram of the in Fig. 10 laser processing systems shown. Fig. 12 is a view of yet another laser processing system. Fig. 13 is a block diagram of the in Fig. 12 laser processing systems shown. Fig. 14 is a flowchart showing the operation of the Fig. The laser processing system shown in section 12 is shown. Fig. 15 is a flowchart showing an example of the flow of step S14 in Fig. 14 shows. Fig. 16 is a diagram showing the relationship between the output data of the Fig. 12 and the distance from the ejection opening. Fig. 17 is a view of yet another laser processing system. Fig. 18 is a block diagram of the in Fig. 17 laser processing systems shown. Fig. 19 is a view of yet another laser processing system. Fig. 20 is a block diagram of the in Fig. 19 laser processing systems shown. Fig. 21 is a flowchart showing the operation of the Fig. The laser processing system shown in section 19 is shown. Fig. 22 is a view of a jet regulating device. Fig. 23 shows an example of the in Fig. 22 Mechanism unit shown. Fig. 24 shows another example of the in Fig. 22 Mechanism unit shown. Fig. 25 is a view of yet another laser processing system. Fig. 26 is a block diagram of the in Fig. 25 laser processing systems shown. Fig. 27 is a flowchart that illustrates the operational process of the in Fig. The laser processing system shown in section 25 is shown. Fig. Figure 28 shows an example of the measuring instrument. Fig. Figure 29 shows another example of the measuring instrument. Detailed explanation

[0009] The embodiments of the present disclosure are explained in detail below with reference to the drawings. In the individual embodiments explained below, identical elements are designated with the same reference numerals, and repeated explanations are omitted. First, with reference to Fig. 1. A laser processing system 10 explained.

[0010] The laser processing system 10 comprises a laser oscillator 12, a laser processing head 14, an auxiliary gas supply device 16, and an arrangement device 18. The laser oscillator 12 performs laser oscillations internally and emits laser light externally. The laser oscillator 12 can be of any type, such as a CO2 laser oscillator, a solid-state laser (YAG laser) oscillator, a fiber laser oscillator, or the like.

[0011] The laser processing head 14 comprises a head body 20, optical lenses 22, a lens drive unit 23, and a nozzle 24. The head body 20 is hollow, and an optical fiber 26 is connected to its base. The laser light emitted by the laser oscillator 12 is transmitted in the optical fiber 26 and shines into the interior of the head body 20.

[0012] The optical lenses 22 include a converging lens and a focusing lens and the like, and converge and condense the laser light irradiated into the interior of the head main body 20 and irradiate it to a workpiece W. The optical lenses 22 are housed inside the head main body 20 so as to be movable in the direction of an optical axis O.

[0013] The lens driving unit 23 moves the individual optical lenses 22 in the direction of the optical axis O. The lens driving unit 23 can control the position of the focal point of the laser light emitted from the nozzle 24 in the direction of the optical axis by regulating the position of the optical lenses in the direction of the optical axis O.

[0014] The nozzle 24 is hollow and is formed at a tip end of the head main body 20. The nozzle has a truncated conical outer shape such that its cross-sectional area perpendicular to the optical axis O decreases from its base end to its tip end, and has a circular ejection opening 28 in its tip end. A chamber 29 consisting of a hollow space is formed inside the nozzle 24 and the head main body 20. The laser light transmitted from the optical lenses 22 is emitted from the ejection opening 28.

[0015] The auxiliary gas supply device 16 delivers an auxiliary gas via an auxiliary gas supply line 30 into the chamber 29, which is formed inside the nozzle 24 and the main body of the head 20. The auxiliary gas is, for example, nitrogen or air. The auxiliary gas supplied to the chamber 29 is ejected together with the laser light from the ejection aperture 28 as a beam along the optical axis O of the laser light. The nozzle 24 forms a point of maximum beam velocity at a position remote from the ejection aperture 28.

[0016] The jet of the auxiliary gas ejected from the nozzle 24 is described below with reference to Fig. 2 and Fig. 3 explained. Fig. 2 is an illustration for which the jet ejected from the ejection opening 28 of the nozzle 24 was photographed with a high-speed camera. Fig. 3 shows the Fig. 2 and a diagram schematically showing the relationship between the velocity V of the beam and the position x in the direction along the optical axis O away from the ejection opening 28.

[0017] In this text, the “speed” of the jet is defined as a parameter that represents the flow velocity (unit: m / s) and the flow rate (unit: m 3 / s) of the auxiliary gas is included. The one in Fig. 2 and Fig. The jet shown in Figure 3 was formed under the conditions of a supply pressure into the chamber 29 of 1 MPa and an opening dimension (diameter) of the ejection port 28 of 2 mm.

[0018] As in Fig. 2 and Fig. Figure 3 shows that in the jet of auxiliary gas ejected from nozzle 24, a first Mach disk region 33 and a second Mach disk region 35 are formed at positions located in the direction of the optical axis O away from the ejection aperture 28, where its velocity is maximized. The first Mach disk region 33 contains position x1 of a first maximum velocity point 32, and the second Mach disk region 35 contains position x2 of a second maximum velocity point 34.

[0019] More specifically, as shown in the diagram of Fig. 3, the speed V of the beam gradually increases with the distance from the position of the ejection opening 28 (i.e., x = 0) along the optical axis O and reaches the first maximum point 32 at the position x1. Fig. In the figure shown in Figure 3, x1 ≒ 4 mm. In the first Mach disk region 33, which contains the position x1, the jet and the reflection waves of the auxiliary gas reflected at the boundary with the air on the outside of this jet interfere with each other and reinforce each other, and a so-called Mach disk is formed.

[0020] With increasing distance from the ejection aperture 24 along the optical axis O beyond position x1, the velocity V decreases abruptly and then begins to increase, reaching its second maximum point 34 at position x2. A second Mach disk is formed in the Mach disk region 35 that contains position x2.

[0021] In this way, in the jet ejected from the nozzle 24, a plurality of Mach disks are formed in the direction of the optical axis O, and the velocity V of the jet thereby has a plurality of maximum points 32, 34 in the direction of the optical axis O. The number of Mach disks formed (i.e., maximum points) increases according to the velocity V of the ejected jet.

[0022] In the invention of the present application, when laser machining a workpiece W by the laser machining system 10, the nozzle 24 is arranged at a predetermined target position with respect to a machining location S of the workpiece W based on the positions x1, x2 of the maximum points 32, 34 so that the workpiece W (specifically, the machining location S of the workpiece W) is arranged in one of the Mach disk areas 33 and 35.

[0023] Previously, it was desirable to maximize the pressure of the auxiliary gas blown onto the workpiece W during laser processing. The pressure of the auxiliary gas is at its maximum at the position of the ejection opening 28. Therefore, during laser processing, the workpiece W was previously positioned as close as possible to the ejection opening 28, where the pressure is greatest. Specifically, the workpiece W was previously positioned in a close proximity 36 in Fig. 3. This near region 36 is a region that is closer to the discharge opening 28 than the first maximum point 32 and in which the pressure of the auxiliary gas reaches a value that is close to the maximum value.

[0024] When the nozzle 24 and the workpiece W are brought close together, a plasma can easily form between the nozzle 24 and the workpiece W during laser processing while the nozzle 24 is moved at high speed relative to the workpiece W. If a plasma forms, the finished surface of the workpiece W can become rough. Furthermore, when the nozzle 24 and the workpiece W are brought close together, the likelihood also increases that particles molten and splashed by the laser processing from the ejection port 28 will enter the interior of the nozzle 24 and contaminate components (for example, a protective glass) of the laser processing head 14.

[0025] The inventors of the present invention have found, as a result of diligent investigations, that the higher the speed V of the shielding gas blown during laser processing of the workpiece W, the more effectively the material of the workpiece W melted by the laser light can be blown away by the assist gas.

[0026] Based on this finding, the inventors of the present invention focused their attention on the formation of the maximum points 32, 34 described above during the emission of the auxiliary gas jet from the emission opening 28 of the nozzle 24 and found that the auxiliary gas can be blown onto the workpiece W at a higher velocity V than in the immediate vicinity of the emission opening 28 when the workpiece W is arranged in a Mach disk area 33 or 35 during laser processing.

[0027] With further reference to Fig. 1, the arranging device 18 arranges the nozzle 24 with respect to the machining location S at a target position determined based on the position x1 or x2 of the maximum point 32 or 34 to arrange the workpiece W (for example, its machining location S) in the Mach disk area 33 or 35. Specifically, the arranging device 18 includes a workpiece table 38, a y-axis moving mechanism 40, an x-axis moving mechanism 42, and a z-axis moving mechanism 44.

[0028] The workpiece table 38 is fixed to the floor of a work cell. For example, the workpiece table 38 has several pins that extend in the z-axis direction. Fig. The workpiece W is positioned on a setup surface formed by the tips of several pins. The z-axis direction, for example, runs essentially parallel to the vertical direction.

[0029] The y-axis movement mechanism 40 includes a pair of rail mechanisms 46 and 48 and a pair of columns 50 and 52. The rail mechanisms 46 and 48 include, for example, servo motors and ball screw mechanisms (both not shown) and extend in the y-axis direction. The rail mechanisms 46 and 48 move the columns 50 and 52 in the y-axis direction, respectively.

[0030] The x-axis motion mechanism 42, for example, contains a servo motor and a ball screw mechanism (both not shown), is fixed to columns 50 and 52, and extends between columns 50 and 52. The x-axis motion mechanism 42 moves the z-axis motion mechanism 44 in the x-axis direction. The z-axis motion mechanism 44, for example, contains a servo motor and a ball screw mechanism (both not shown) and moves the laser processing head 14 in the z-axis direction. The laser processing head 14 is configured on the z-axis motion mechanism 44 such that the optical axis O of the emitted laser light is parallel to the z-axis.

[0031] During the processing of a workpiece W, the positioning device 18 aligns the nozzle 24 at a target position relative to the processing point S. For example, a control unit (not shown) integrated into the laser processing system 10 (discussed later) controls the positioning device 18, and the nozzle 24 and the workpiece W are automatically positioned at the target position. Alternatively, an operator can manually actuate the positioning device 18 and align the nozzle 24 at the target position relative to the processing point S.

[0032] The auxiliary gas supply device 16 then delivers the auxiliary gas into the chamber 29, and a jet of the auxiliary gas, exhibiting Mach disk regions 33 and 35, is ejected from the ejection port 28. The laser oscillator 12 then emits laser light to the laser processing head 14, which in turn emits the laser light from the ejection port 28, directing it towards the workpiece W. The lens drive unit 23 regulates the position of the optical lenses 22 in the direction of the optical axis O so that the focal point of the laser light emitted from the ejection port 28 is positioned at the processing point S.

[0033] In this way, the workpiece W is laser machined in a state where the workpiece W has been placed in the Mach disk region 33 or 35 of the beam. Since this configuration allows the assist gas ejected from the nozzle 24 to be blown onto the workpiece at a higher velocity V than in the vicinity 36 of the ejection port during machining of the workpiece W, the material of the workpiece melted by the laser light can be effectively blown away by effectively utilizing the assist gas.

[0034] Since the plasma generation described above can be suppressed compared to arranging the workpiece W in the immediate vicinity 36 of the ejection aperture, the final manufacturing quality of the workpiece W can be increased. Furthermore, since the penetration of particles splashing from the workpiece W, generated during laser processing, into the interior of the nozzle 24 can be suppressed compared to arranging the workpiece W in the immediate vicinity 36, contamination of components of the laser processing head 14 can be prevented.

[0035] Next, with reference to Fig. 4 and Fig. 5. A beam monitoring device 60 is described. The beam monitoring device 60 obtains information indicating the positions x1, x2 of the maximum points 32, 34 described above. The beam monitoring device 60 comprises a control unit 62, a dummy workpiece 64, a measuring instrument 66, and the arrangement device 18 described above. The control unit 62 has a processor (CPU, GPU, or the like), a memory unit (ROM, RAM, or the like), etc., and controls the measuring instrument 66 and the arrangement device 18.

[0036] The dummy workpiece 64 is set up on the setup surface of the workpiece table 38. The dummy workpiece 64 has the same external shape (the same dimensions) as the workpiece W and has a dummy machining point 64a corresponding to the machining point S. In the example shown in Fig. As shown in Figure 4, the dummy workpiece 64 is set up in a different position than the setup position of the workpiece W during laser processing.

[0037] The measuring instrument 66 measures the velocity V of the beam ejected from the ejection port 28 at the position of the dummy processing point 64a (or at a position slightly offset from the dummy processing point 64a in the direction of the ejection port 28). For example, the measuring instrument 66 includes a hot-wire anemometer that measures this velocity V through contact, wherein the hot-wire anemometer comprises a hot wire that is positioned in the beam and whose resistance changes according to the velocity V. Or the measuring instrument 66 includes a laser anemometer that measures this velocity V without contact, wherein the laser anemometer comprises an optical laser that shines light onto the beam and measures the velocity V.

[0038] The measuring instrument 66 measures the velocity V of the jet and outputs it as output data (measured value) α to the control unit 62. The measuring instrument 66 can also be arranged on the dummy workpiece 64 or spaced apart from the dummy workpiece 64. The dummy workpiece 64 is positioned upstream (i.e., downstream) in the direction of jet flow, and the measuring instrument 66 measures the velocity V at a position between the ejection opening 28 and the dummy workpiece 64.

[0039] The arrangement device 18 comprises the workpiece table 38, the y-axis movement mechanism 40, the x-axis movement mechanism 42 and the z-axis movement mechanism 44, moves the laser processing head 14 in the directions of the x-axis, the y-axis and the z-axis, and thereby moves the laser processing head 14 in relation to the dummy workpiece 64 and the measuring instrument 66.

[0040] Next, the method for obtaining the positions x1, x2 of the maximum points 32, 34 using the beam monitoring device 60 will be explained. First, the control unit 62 operates the positioning device 18, and the laser processing head 14 is positioned at a measurement start position. When the laser processing head 14 is positioned at the measurement start position, the laser processing head 14 is moved as shown in Fig. 4 shown positioned in relation to the dummy workpiece 64 and the measuring instrument 66 such that the optical axis O of the laser processing head 14 crosses the processing point 64a of the dummy workpiece 64.

[0041] Furthermore, the distance reaches d a between the ejection opening 28 and the measuring position of the measuring instrument 66 (that is, the position of the dummy processing point 64a) an initial value d a0 As an example, the initial value d a0set so that the measuring position of the measuring instrument 66 is at a position near the ejection opening 28 such as the near area 36 in Fig. 3 is ordered.

[0042] As another example, the initial value d a0 such that the measuring position of the measuring instrument 66 is arranged at a position that is located at a position where the maximum point furthest from the ejection opening 28 (in the example of Fig. 3 the second maximum point 34) is assumed to be sufficiently spaced from the downstream side of the jet. The initial value d a0 is determined in advance by the operator.

[0043] Then the control unit 62 sends a command to the auxiliary gas supply device 16, and the auxiliary gas supply device 16, which has received this command, delivers the auxiliary gas into the chamber 29 at a supply pressure Ps. The nozzle 24 expels a gas as described in... Fig. 2 and Fig. 3 shown jet of the auxiliary gas with maximum points 32 and 34 of the velocity V.

[0044] Subsequently, the control unit 62 operates the arrangement device 18 and the laser processing head 14 is moved in the z-direction so that the distance d a between the measuring position of the measuring instrument 66 and the discharge opening 28. If, as an example, the initial value d a0 has been set so that the measuring position of the measuring instrument 66 is arranged at a position near the ejection opening 28, the control unit 62 operates the arranging device 18 and the laser processing head 14 is moved in the positive z-direction so that the distance d a gets bigger.

[0045] As another example, if the initial value d described above a0Since the measuring position of the measuring instrument 66 is set such that it is located on the downstream side of the maximum point furthest from the ejection opening 28, the control unit 62 operates the arrangement device 18 and the laser processing head 14 is moved in the negative z-direction such that the distance d a becomes smaller.

[0046] While the mounting device 18 moves the laser processing head 14 in the z-axis direction, the control unit 62 sends a command to the measuring instrument 66, and the speed V is continuously measured by the measuring instrument 66. For example, the measuring instrument 66 continuously measures the speed V during the movement of the laser processing head 14 by the mounting device 18 at a specific period (for example, 0.5 seconds). Thus, the measuring position of the measuring instrument 66 is moved relative to the beam, and the measuring instrument 66 continuously measures the speed V along the beam.

[0047] The measuring instrument 66 outputs the measured velocity V as output data α (= V) to the control unit 62. The relationship between the output data α thus output by the measuring instrument 66 and the distance d a corresponds to the in Fig. 3 between the speed V and the position x. That is, the output data α obtained from the measuring instrument 66 changes according to the distance d a , have a first peak value a at a position corresponding to the first maximum point 32 max1 and have a second peak value a at a position corresponding to the second maximum point 34 max2 on.

[0048] The control unit 62 obtains the first peak value α max1 the output data α continuously output from the measuring instrument 66 as information indicating the position x1 of the first maximum point 32, and obtains the second peak value α max2the output data α continuously output by the measuring instrument 66 as information indicating the position x2 of the second maximum point 34. In this way, the control unit 62 acts as a position acquisition unit 68, which acquires the positions of the maximum points 32, 34 based on the output data α.

[0049] Then the control unit 62 achieves the distance d a between the measuring position of the measuring instrument 66 (that is, the position of the dummy processing point 64a) and the ejection opening 28 during the measurement of the first peak value α max1 as target distance d T This target distance d T indicates the position of the first maximum point 32 with respect to the ejection opening 28 and can be obtained, for example, using a well-known distance sensor or displacement meter or the like.

[0050] Then the control unit 62 creates a database of the target distance d. TThe control unit 62 correlates the opening dimension ∅ of the discharge opening 28 and the supply pressure Ps at the time of measurement of the velocity V and stores this information in the storage unit. The operator makes various changes to the opening dimension ∅ of the discharge opening 28 and the supply pressure Ps, and with each change in the opening dimension ∅ of the discharge opening 28 and the supply pressure Ps, the control unit 62 obtains a target distance d using the procedure described above. T and enters this into the database. If the ejection opening is 28 round, the opening dimension is the diameter.

[0051] Table 1 below shows an example of the database consisting of the opening dimension ∅, the supply pressure Ps and the target distance d. T shown. Table 1 Zufuhrdruck Ps 0,8 MPa ... 2,0 MPa Öffnungsabmessung Ø ∅ 1,0 d T = 4 mm ... d T = 6 mm ... ... ... ... ∅ 4,0 d T = 6 mm ... d T = 10 mm

[0052] The database shown in Table 1 contains several target distances d Tin a correlation with the opening dimension ∅ of the discharge opening 28 and the supply pressure Ps. Furthermore, the control unit 62 can also determine the distance d. a_2 between the ejection opening 28 and the measuring position of the measuring instrument 66 during the measurement of the second peak value α max2 as a second target distance d T_2 obtain and in the same way create a database for this second target distance d T_2 It is also possible to create a separate database for each type of auxiliary gas (nitrogen, air, or the like).

[0053] The databases created in this way for the target distance d Tare used, as described below, to determine the target position at which the nozzle 24 is to be positioned during the laser processing of a workpiece W by the laser processing system 10. For example, if the opening dimension ∅ of the nozzle 24 used during laser processing is 4 mm, and the supply pressure Ps into the chamber 29 is 2.0 MPa, data that d T Specify 10 mm, used to define the target position.

[0054] In this way, by measuring the velocity V of the auxiliary gas jet, information indicating the positions of the maximum points 32 and 34 can be obtained. This method allows the positions of the maximum points to be determined with high accuracy through measurement.

[0055] Furthermore, the beam observation device 60 includes the dummy workpiece 64. In actual laser processing, an auxiliary gas is blown towards a workpiece W. In the beam observation device 60, the auxiliary gas is blown towards the dummy workpiece 64 instead of the workpiece W, and the positions of the maximum points 32, 34 are measured from the velocity V measured at the position of the dummy processing point 64a. Since the positions of the maximum points 32, 34 can be measured in a state that closely resembles actual laser processing using this method, the positions of these maximum points 32, 34 can be measured with even higher accuracy.

[0056] The dummy workpiece 64 has the same outer shape (same dimensions) as the workpiece W. Since the positions of the maximum points 32, 34 can be measured in a state close to the actual laser processing by this embodiment, the positions of these maximum points can be measured with even higher accuracy. The dummy workpiece 64 may also have a different outer shape (different dimensions) than the workpiece W. In this case, the dummy workpiece 64 may have the same thickness in the z-axis direction as the workpiece W and a location 64a corresponding to the processing location S. The positions of the maximum points 32, 34 can also be obtained without using a dummy workpiece 64.

[0057] Next, with reference to Fig. 6 and Fig. Figure 7 describes a beam monitoring device 70. The beam monitoring device 70 obtains information indicating the positions x1, x2 of the maximum points 32, 34 described above. The beam monitoring device 70 comprises a control unit 72, a measuring instrument 76, and the arrangement device 18. The control unit 72 has a processor and a memory unit (not shown) and controls the measuring instrument 76 and the arrangement device 18.

[0058] The arrangement device 18 comprises the workpiece table 38, the y-axis movement mechanism 40, the x-axis movement mechanism 42, and the z-axis movement mechanism 44, wherein an object 74 is positioned on the workpiece table 38. The arrangement device 18 moves the laser processing head 14 in the directions of the x-axis, the y-axis, and the z-axis, thereby moving the nozzle 24 relative to the object 74.

[0059] Object 74 has a round through-hole 74a. The opening dimension of this through-hole 74a is set to approximately the same dimension as the opening dimension of a through-hole assumed to be formed when a workpiece W is drilled through by the laser light emitted from the nozzle 24. Object 74 can have the same external shape (the same dimensions) as the workpiece W, or it can have a different external shape (different dimensions). Furthermore, object 74 can have the same thickness in the z-axis direction as the workpiece W and a point corresponding to the machining point S.

[0060] The measuring instrument 76 is arranged next to the through-opening 74a and measures the sound pressure SP or the frequency f of a noise generated when the jet ejected from the outlet 28 of the nozzle 24 passes through the through-opening 74a and impacts the object 74. In this text, the "sound pressure" of the noise includes not only the sound pressure (unit: Pa) but also the sound pressure level (unit: dB) and the intensity of the noise (unit: W / m²). 2 ), and the like.

[0061] The "frequency" of the noise includes not only the frequency of the noise itself, but also its frequency characteristics (that is, its frequency spectrum). These frequency characteristics contain information such as the sound pressure level of at least one frequency component (for example, 1 Hz) or the average sound pressure level of a specific frequency band (for example, 1 kHz to 10 kHz), or the like. The measuring instrument 76 comprises a microphone 76a, which converts the noise into an electrical signal, and a frequency acquisition unit 76b, which derives the frequency characteristics of the noise from the electrical signal.

[0062] The procedure for obtaining positions x1, x2 of the maximum points 32, 34 using the beam observation device 70 is then explained. First, the control unit 72 actuates the arrangement device 18 and the laser processing head 14 is positioned at a measurement start position. Once the laser processing head 14 has been positioned at the measurement start position, it is moved as described in Fig. Figure 6 is shown positioned in relation to object 74 such that the optical axis O of the laser processing head 14 passes through the through-hole 74a. A distance d b An initial distance d is maintained between the ejection opening 28 and the object 74. b0 .

[0063] As an example, the initial distance d b0 so that the object 74 is positioned near the ejection opening 28, such as the near area 36 in Fig. 3 is arranged. As another example, the initial distance d b0so that object 74 is positioned at a location that is determined by a position where the maximum point furthest from the ejection opening 28 (in the example of Fig. 3 the second maximum point 34) is presumed to be sufficiently spaced away from the downstream side of the beam.

[0064] The control unit 72 then sends a command to the auxiliary gas supply device 16, which, having received this command, delivers the auxiliary gas into chamber 29 at a supply pressure Ps. The nozzle 24 emits a jet of the auxiliary gas with maximum points 32 and 34. Subsequently, the control unit 72 actuates the arrangement device 18, and the laser processing head 14 is moved in the z-direction such that the distance d b between object 74 and ejection opening 28.

[0065] If, for example, the initial value d described above b0Once it has been determined that the object 74 is positioned near the ejection opening 28, the control unit 72 operates the arrangement device 18 and the laser processing head 14 is moved in the positive z-direction such that the distance d b gets bigger.

[0066] As another example, if the initial value d described above b0 Since it has been determined that the object 74 is positioned on the downstream side of the maximum point furthest from the ejection opening 28, the control unit 72 operates the arrangement device 18 and the laser processing head 14 is moved in the negative z-direction such that the distance d b becomes smaller.

[0067] While the array device 18 moves the laser processing head 14 in the z-axis direction and the nozzle 24 approaches or moves away from the object 74, the control unit 72 sends a command to the measuring instrument 76, and the sound pressure SP or the frequency f is continuously measured by this measuring instrument 76. For example, the measuring instrument 76 continuously measures the sound pressure SP or the frequency f at a certain period (e.g., 0.5 seconds) while the laser processing head 14 is moved by the array device 18. The measuring instrument 76 outputs the measured sound pressure SP or the measured frequency f sequentially as output data β (= SP or f) to the control unit 72.

[0068] Here, the sound pressure SP or the frequency f of the noise generated by the jet's impact on object 74 as it passes through the opening 74a is highly correlated with the flow velocity Vs of the auxiliary gas. Specifically, the sound pressure (peak value, RMS value) of the noise generated by the jet's impact on object 74, or the frequency characteristics of the noise (for example, the sound pressure level of at least one frequency component), are highly correlated with the flow velocity Vs of the auxiliary gas.

[0069] Therefore, the relationship between the obtained initial data β and the distance d is... b the in Fig. This corresponds to diagram 3. That is, the output data β from the measuring instrument 76 changes according to the distance d. b, exhibit a first peak value β at a position corresponding to the first maximum point 32. max1 and exhibit a second peak value β at a position corresponding to the second maximum point 34. max2 on.

[0070] The control unit 72 reaches the first peak value β max1 the output data β continuously provided by the measuring instrument 76 as information indicating the position x1 of the first maximum point 32, and obtains the second peak value β max2 the output data β continuously output by the measuring instrument 76 as information indicating the position x2 of the second maximum point 34. In this way, the control unit 72 acts as a position acquisition unit 78, which acquires the positions of the maximum points 32, 34 based on the output data β.

[0071] Then the control unit 72 achieves the distance d bbetween object 72 and the ejection opening 28 during the measurement of the first peak value β max1 as target distance d T This target distance d T indicates the position of the first maximum point 32 in relation to the ejection opening 28 and can be obtained, for example, using a generally known distance sensor or the like.

[0072] Then, control unit 72 creates a database of the target distance d. T and the first peak value β max1 in correlation with the opening dimension ∅ of the discharge opening 28 and the supply pressure Ps at the time of measurement of the sound pressure SP and the frequency f. Table 2 below shows an example of the database consisting of the opening dimension ∅, the supply pressure Ps, the first peak value β max1 and the target distance d T shown. Table 2 Zufuhrdruck Ps 0,8 MPa ... 2,0 MPa Spitzenwert Abstand ... Spitzenwert Abstand Öffnungsabmessung ∅ ∅ 1,0 114 dB d = 4 mm ... 120 dB d = 6 mm ... ... ... ... ... ... ∅ 4,0 110 dB d = 6 mm ... 117 dB d = 10 mm

[0073] In the database shown in Table 2, the first peak value β max1 (sound pressure level) and the target distance d T in correlation with the opening dimension ∅ of the nozzle 24 and the supply pressure Ps. The control unit 72 can also determine the distance d. b_2 between the ejection opening 28 and the object 74 at the time of measurement of the second peak value β max2 as a second target distance d T_2 obtain and in the same way create a database for this second target distance d T_2 create.

[0074] It is also possible to create a separate database for each type of auxiliary gas (nitrogen, air, or the like). The databases created in this way for the target distance d T are used as described below to determine the target position at which the nozzle 24 is to be arranged when the laser processing system laser processes a workpiece W.

[0075] As described above, the beam monitoring device 70 can obtain information indicating the positions x1, x2 of the maximum points 32, 34 based on the sound of the auxiliary gas beam impacting the object 74. This method allows the positions x1, x2 of the maximum points 32, 34 to be determined with high accuracy through measurement. Furthermore, the beam monitoring device 70 can obtain information indicating the positions x1, x2 of the maximum points 32, 34 during laser processing, as described below.

[0076] Next, with reference to Fig. 8 and Fig. 9. A beam monitoring device 80 is described. The beam monitoring device 80 attains the position x1 of the first maximum point 32 described above through a specific operation. The beam monitoring device 80 comprises a control unit 82 and a measuring instrument 84. The control unit 82 has a processor and a memory unit (not shown) and controls the measuring instrument 84.

[0077] The measuring instrument 84 measures the supply flow rate Vv of the auxiliary gas supplied from the auxiliary gas supply device 16 into the chamber 29. The measuring instrument 84 is formed on a gas supply line 30 and measures the flow rate Vv of the auxiliary gas flowing in the gas supply line 30 from the auxiliary gas supply device 16 to the chamber 29.

[0078] Next, the procedure for obtaining position x1 of the first maximum point 32 by the jet monitoring device 80 is explained. First, the control unit 82 sends a command to the auxiliary gas supply device 16, and the auxiliary gas supply device 16, which has received this command, delivers the auxiliary gas into the chamber 29. The nozzle 24 emits a jet of the auxiliary gas, which has maximum points 32 and 34.

[0079] The control unit 82 then sends a command to the measuring instrument 84, and the measuring instrument 84, which has received this command, measures the supply flow rate Vv of the auxiliary gas from the auxiliary gas supply device 16 to the chamber 29. The measuring instrument 84 outputs the supply flow rate Vv as output data (measured value) to the control unit 82. The control unit 82 then calculates a distance d using the output data Vv from the measuring instrument 84 and the formula 1 given below. cfrom the ejection opening 28 to the first maximum point 32 as information regarding the position x1 of the first maximum point 32. dc=0.67×∅×(ρVs2 / 2)1 / 2

[0080] Here, ∅ represents the opening dimension of the discharge opening 28, ρ the viscosity coefficient of the auxiliary gas, and Vs is the flow velocity Vs of the auxiliary gas determined from the output data Vv and the opening diameter ∅. In this way, the control unit 82 acts as a position acquisition unit 86, which obtains the position x1 of the first maximum point 32 by a calculation from the output data Vv of the measuring instrument 84.

[0081] By means of the beam monitoring device 80, the position x1 of the first maximum point 32 can be obtained quickly and with high accuracy through calculation. Furthermore, the beam monitoring device 80 can obtain the position x1 of the first maximum point 32 in real time during laser processing, as described below.

[0082] Next, with reference to Fig. 10 and Fig. Figure 11 describes a laser processing system 100. The laser processing system 100 comprises the laser oscillator 12, the laser processing head 14, the auxiliary gas supply device 16, the arrangement device 18, and a control unit 102. The control unit 102 has a processor (not shown) and a memory unit 104 and controls the laser oscillator 12, the laser processing head 14, the auxiliary gas supply device 16, and the arrangement device 18. The memory unit 104 stores a database 106. The database 106 is, for example, a database such as those shown in Table 1 and Table 2, which were described above.

[0083] Next, the operation of the laser processing system 100 will be explained. First, the control unit 102 acquires the opening dimension ∅ of the ejection port 28 of the nozzle 24 used and the set value of the supply pressure Ps of the auxiliary gas from the auxiliary gas supply device 16 to the chamber 29, and obtains the corresponding target distance d from the opening dimension ∅ and the set value of the supply pressure Ps. T in the database 106 by reading from the storage unit 104.

[0084] Then the control unit 102 operates the arrangement device 18 and the laser processing head 14 is moved in relation to the workpiece W and the nozzle 24 is moved to a target position where the distance d between the ejection opening 28 and the processing point S is equal to the target distance d TIn this way, the target position is determined using the database 106, and the control unit 102 acts as a motion control unit 108, which controls the arranging device 18 (i.e., the moving mechanisms 40, 42, 44) and arranges the nozzle 24 at the target position.

[0085] The control unit 102 then operates the auxiliary gas supply device 16, supplying the auxiliary gas to the chamber 29 at a supply pressure Ps, and the nozzle 24 ejects a jet of the auxiliary gas exhibiting maximum points 32, 34 of velocity V. The control unit 102 then operates the laser oscillator 12, causing laser light to be emitted from the ejection aperture 28, and operates the lens drive unit 23, regulating the position of the optical lenses 22 in the direction of the optical axis O so that the focal point of the emitted laser light is positioned at the processing point S.

[0086] As a result, the laser light creates a through hole at the processing point S of the workpiece W.

[0087] The control unit 102 operates the positioning device 18 according to a processing program stored in the storage unit 104 and performs laser processing of the workpiece W (specifically, laser cutting) while moving the nozzle 24 relative to the workpiece W. At this time, the processing location S of the workpiece W is positioned in the first Mach disk area 33 (specifically, at the position of the first maximum point 32) of the assist gas jet.

[0088] The laser processing system 100 effectively blows away the workpiece material melted by the laser light through the efficient use of the auxiliary gas. Furthermore, since the plasma formation described above can be suppressed, the final manufacturing quality of the processing point S of the workpiece W can be increased, and contamination of the components of the laser processing head 14 can be prevented.

[0089] Furthermore, in the laser processing system 100, the target position at which the nozzle 24 is to be positioned during the processing of the workpiece W is determined using the database 106 with respect to the position of the first maximum point 32. This design allows the laser processing to be started with faster and easier positioning of the nozzle 24 and the workpiece W at the target position.

[0090] In the laser processing system 100, the storage unit 104 can also be designed as a separate element from the control unit 102. In this case, the storage unit 104 can also be integrated into an external device (a server or the like) that is communicatively connected to the control unit 102, or it can be a storage medium (a hard drive or flash memory, or the like) that is externally connected to the storage unit 102. The control unit 104 can also fix the distance between the ejection opening 28 and the workpiece W during the laser processing of the workpiece W.

[0091] Next, with reference to Fig. 12 and Fig. 13 a laser processing system 110 is explained. The laser processing system 110 comprises the laser oscillator 12, the laser processing head 14, the auxiliary gas supply device 16, the arrangement device 18, the measuring instrument 76 and a control unit 112.

[0092] The control unit 112 includes a processor and the storage unit 104, and controls the laser oscillator 12, the laser processing head 14, the auxiliary gas supply device 16, the arranging device 18, and the measuring instrument 76. The storage unit 14 stores the database 106 shown in Table 2 above. The control unit 112 functions as the position acquisition unit 78 described above. That is, in this laser processing system 110, the arranging device 18, the measuring instrument 76, and the control unit 112 constitute the beam monitoring device 70 described above.

[0093] Next, with reference to Fig. Section 14 explains the operation of the laser processing system 110. The one in Fig. The sequence shown in Figure 14 is started when the control unit 112 has received a command to start processing from the operator, a higher-level control or a processing program.

[0094] In step S1, the control unit 112 positions the nozzle 24 at the initial target position with respect to the machining point S. Specifically, the control unit 112 obtains the opening dimension ∅ of the discharge opening 28 of the nozzle 24 and the set value of the supply pressure PS of the auxiliary gas to the chamber 29, and determines the corresponding target distance d from the opening dimension ∅ and the set value of the supply pressure PS by reading this information. Tin database 106. Subsequently, the control unit 112 acts as a motion control unit 108 and operates the arrangement device 18, and the laser processing head 14 is moved in relation to the workpiece W, and the nozzle 24 is at the initial target position, where the distance d between the ejection opening 28 and the processing point S is equal to the target distance d. T agrees, ordered.

[0095] In step S2, the control unit 112 supplies the auxiliary gas at supply pressure PS from the auxiliary gas supply device 16 into the chamber 29 and emits a jet of the auxiliary gas from the discharge opening 28. The control unit 112 also operates the laser oscillator 12, emits laser light from the discharge opening 28, and operates the lens drive unit 23, regulating the position of the optical lenses 22 in the direction of the optical axis O so that the focal point of the emitted laser light is located at the processing point S. As a result, a through-hole H is created in the workpiece W ( Fig. 12) formed and the beam passes through this opening H. This opening H corresponds to the opening 74a described above.

[0096] In step S3, the control unit 112 begins the measurement using the measuring instrument 76. Specifically, the control unit 112 sends a command to the measuring instrument 76, and the measuring instrument 76, which has received this command, continuously measures (for example, with a specific period) the sound pressure SP or the frequency f of the noise that arises when the jet ejected from the ejection opening 28 of the nozzle 24 passes through the passage opening H and impacts the workpiece W.

[0097] The control unit 112 acts as a position acquisition unit 78 and receives the output data β of the sound pressure SP or the frequency f from the measuring instrument 76 as information indicating the position x1 of the first maximum point 32, sequentially, and stores it in the storage unit 104. As described in connection with the beam monitoring device 70 described above, the output data β, which corresponds to the first peak value β max1contained, an information that specifies the position x1 of the first maximum point 32.

[0098] In step S4, the control unit 112 begins the laser processing. Specifically, the control unit 112 operates the arrangement device 18 according to a processing program, and the workpiece W is processed (laser-cut) by the laser light emitted from the ejection opening 28, while the nozzle 24 is moved relative to the workpiece W.

[0099] In step S5, the control unit 112 determines whether the output data β, which the measuring instrument 76 last obtained, is smaller than a predefined lower limit β. min are or are not. This lower limit β min determines a limit as to whether the velocity V of the jet emitted from nozzle 24 has become abnormally low or not, and is predetermined by the operator.

[0100] Now, if the discharge port 28 is clogged or an abnormality (for example, a gas shortage) occurs during the operation of the auxiliary gas supply device 16, the jet velocity V may decrease significantly from a reference value. In this case, the output data β obtained by the measuring instrument 76 differs from the reference data measured by the measuring instrument 76 when the jet is normally discharged from the nozzle 24 (specifically, they become smaller).

[0101] The control unit 112 determines whether the output data β is less than the lower limit β. min Whether the output data β differ from the reference data or not. In this way, the control unit 112 acts as an anomaly detection unit 113, which determines whether the output data β differ from the reference data or not.

[0102] If the control unit 112 determines that the output data β is less than the lower limit β min If they are (that is, YES), it proceeds to step S6. If, on the other hand, the control unit 112 determines that the output data β at least meets the lower limit β min If the value is NO, it proceeds to step S8. In step S6, the control unit 112 sends a command to the laser oscillator 12, stopping the laser oscillation operation and thus halting the laser processing of the workpiece W.

[0103] In step S7, the control unit 112 issues an alarm. For example, the control unit 112 generates a warning signal in the form of a voice output or a screen display of "Anomaly in the auxiliary gas discharge. Check the nozzle opening dimension or the auxiliary gas supply pressure." The control unit 112 then outputs this alarm via a loudspeaker or a display unit (not shown). In this way, the control unit 112 acts as a warning generation unit 118, which generates a warning.

[0104] The loudspeaker or display unit can be integrated into the control unit 112 or located outside of it. The operator intuitively recognizes through the alarm that an anomaly exists in the nozzle 24 or the auxiliary gas supply and can replace the nozzle 24 or take action to correct the operational anomaly (for example, a gas shortage) of the auxiliary gas supply device 16. After the execution of this step S7, the control unit 112 terminates the process described in Fig. 14 shown process.

[0105] In step S8, the control unit 112 determines whether the output data β obtained most recently by the measuring instrument 76 is less than a predefined threshold value β th are or not. This threshold β th is a value that is greater than the lower limit β described above. min This threshold β is an example. thas the value for which the first peak value β contained in the database 106 max1 multiplied by a certain coefficient a (0 < a < 1).

[0106] For example, if database 106 shown in Table 2 described above is used and the opening dimension ∅ = 1, the supply pressure Ps = 2.0 MPa, and a = 0.95 are set, the limit β th 120 dB × 0.95 = 114 dB. The relationship between the output data β and the position x of the machining point S of the workpiece W with respect to the ejection opening 28 is shown in Fig. 16 is shown schematically. The relationship between the output data β and the position x corresponds to that shown in Fig. 3 diagrams shown.

[0107] A range 116 from the limit β th up to the first peak value β max1This corresponds to a position range 114 between position x3 and position x4. Position x1 of the first maximum point 32 is included in this position range 114. Here, the nozzle 24 is positioned at an initial target position during step S1 described above, where the distance d between the ejection opening 28 and the processing position S corresponds to the target distance d. T Consequently, it is interpreted that the machining position S after the end of step S1 is located at the position x1 of the first maximum point 32 or in its vicinity.

[0108] However, during the laser processing of the workpiece W, the distance d between the ejection opening 28 and the processing location S may change due to some factor. As a result, a step may be formed at the processing location S of the workpiece W, causing the distance d to change. When the distance d changes in this way, the output data β of the measuring instrument 76 may not exceed the threshold value β. th fall below.

[0109] If the control unit 112 determines in this step S8 that the output data β is less than the threshold β th If they are (that is, YES), it proceeds to step S9. If, on the other hand, the control unit 112 determines that the output data β is at least equal to the threshold β th If the value is NO, she proceeds to step S15.

[0110] In step S9, the control unit 112 changes the target position of the nozzle 24. Specifically, at the start of step S9, the control unit 112 changes the target position of the nozzle 24 to a new target position moved in the negative z-axis direction or in the positive z-axis direction. Then, the control unit 112 acts as the movement control unit 108 and operates the arranging device 18, and the nozzle 24 is moved in the negative z-axis direction or in the positive z-axis direction to arrange the nozzle 24 at the new target position. As a result, the nozzle 24 approaches or moves away from the workpiece W.

[0111] In step S10, the control unit 112 determines whether the output data β obtained by the measuring instrument 76 immediately before step S9 is exceeded by the output data β obtained by the measuring instrument 76 after the completion of step S9.

[0112] If the output data β has decreased as a result of the movement of the nozzle 24 in step S9, the position of the workpiece W (specifically, the machining point S) in the diagram of Fig. 16 from the position area 114. Consequently, in this case, to record the position of the workpiece W in the position area 114, it is necessary to reverse the direction in which the nozzle 24 is moved in step S9.

[0113] If the output data β has increased as a result of the movement of the nozzle 24 in step S9, the position of the workpiece W in the diagram of Fig. 16 is approaching the position x1. Consequently, in this case, it is not necessary to change the direction in which the nozzle 24 is moved in step S9.

[0114] If, in step S10, the control unit 112 determines that the output data β obtained by the measuring instrument 76 immediately before step S9 is exceeded by the output data β obtained by the measuring instrument 76 after the completion of step S9 (i.e., YES), it proceeds to step S12. Conversely, if the control unit 112 determines that the output data β obtained by the measuring instrument 76 immediately before step S9 is less than the output data β obtained by the measuring instrument 76 after the completion of step S9 (i.e., NO), it proceeds to step S11.

[0115] In step S11, the control unit 112 reverses the direction of movement of the nozzle 24. For example, if the nozzle 24 was moved in the negative z-axis direction in the preceding step S9, the control unit 112 reverses the direction in which the nozzle moves in the immediately following step S9 to the positive z-axis direction. Then the control unit 112 returns to step S9.

[0116] In step S12, the control unit 112 determines whether the output data β last acquired by the measuring instrument 76 is at least the threshold value β th or not. If the control unit 112 determines that the output data β is at least the threshold value β th (that is, YES), it proceeds to step S15. On the other hand, if the control unit 112 determines that the output data β is still less than the threshold value β th (that is, NO), it proceeds to step S13.

[0117] In step S13, the control unit 112 determines whether the number of determinations of NO in the above-described step S12 exceeds a predetermined maximum number n max exceeded or not. This maximum number n max is set by the operator to an integer of at least 2 (for example, n max = 10). If the control unit 112 determines that the number n is the maximum number n max (i.e., YES), it proceeds to step S14. On the other hand, if the control unit 112 determines that the number n exceeds the maximum number n max has not exceeded (that is, NO), it returns to step S9.

[0118] In this way, the control unit 112 changes the target position of the nozzle 24 during the machining of the workpiece W by executing steps S9 to S13 in Fig. 14 as a loop so that the output data β of the measuring instrument 76 enters the range 116 of the output data indicating the position range 114, and performs feedback control of the arranging device 18 according to the changed target position, thereby moving the nozzle 24.

[0119] That is, the target position of the nozzle 24 is determined based on the first peak value β max1 The output data β, which specifies the position x1 of the first maximum point 32, is defined as a specific area. Through the feedback control, the machining point S can be continuously positioned within the first Mach disk area 33 during the machining of the workpiece W. That is, the first Mach disk area 33 of the laser machining device 110 can be defined as the circumference of the position range 114, which is determined by the threshold value β. th is defined.

[0120] If YES is determined in step S13, the control unit 112 performs an anomaly processing process in step S14. This does not only occur if the feedback control of steps S9 to S13 is for the number n. max was done repeatedly, but also when it did not lead to β ≧ β th If this occurs, there is a possibility that the aforementioned anomaly of blockage or gas shortage has taken place.

[0121] The Fig. Character 16 shown represents the reference data measured by the measuring instrument 76 when the beam is emitted normally from the ejection port 28 in a state in which no anomaly has occurred, with the first peak value β max1 Reference data is formed and the threshold β th is determined in relation to this reference data. Therefore, range 116 in Fig. 16 a range of output data that was determined on the basis of the reference data and specifies the position range 114.

[0122] The control unit 11 acts as an anomaly detection unit 113 and, upon determination of JA in step S13, determines that the output data of the measuring instrument 76 differs from the reference data, and executes the anomaly processing process of step S14. This step S14 is carried out with reference to Fig. 15 explained. In the Fig. The processes shown in section 15 are the same as those in the [document / section]. Fig. The sequence shown in step 14 is labelled with the same step numbers, and a repeated explanation is omitted.

[0123] In step S21, the control unit 112 sends a command to the auxiliary gas supply device 16, and the supply pressure Ps of the auxiliary gas into chamber 29 is changed. With each execution of step S21, the control unit 112 incrementally increases the supply pressure Ps by a specific pressure (for example, 0.2 MPa). In this way, the control unit 112 acts as a pressure regulating unit 115, which changes the supply pressure Ps.

[0124] The control unit 112 then performs step S12 described above and determines whether the output data β last obtained by the measuring instrument 76 at least meets the threshold value β th Whether or not. If the control unit determines 112 YES, it goes to step S15 in Fig. 14, and if she determines NO, she goes to step S22.

[0125] In step S22, the control unit 112 determines whether a step S12 in Fig. 15 as NO, a specific number m, a predetermined maximum number m max has been exceeded or not. This maximum number m max is defined by the operator as an integer of at least 2 (for example, m) max = 5). If the control unit 112 determines that the number m is the maximum number m max has exceeded the limit (that is, YES), she goes to step S6 in Fig. 14 over. If, on the other hand, the control unit 112 determines that the number m is the maximum number m max If it has not exceeded the limit (that is, NO), it returns to step S21.

[0126] With further reference to Fig. In step S15, for example, the control unit 112 determines, based on the processing program, whether the laser processing is complete or not. If the control unit 112 determines that the laser processing is complete (i.e., YES), it issues a command to the laser oscillator 12, the laser oscillation operation is stopped, and the process ends. Fig. 14. On the other hand, if the control unit 112 determines that the laser processing is not completed (i.e., NO), it returns to step S8.

[0127] As described above, the control unit 112, based on the output data β obtained by the measuring instrument 76 during the machining of the workpiece W, performs feedback control of the nozzle 24's position such that the machining point S1 is continuously positioned within the first Mach disk area 33. This design allows the workpiece W to be laser-machined even if the distance d between the ejection opening 28 and the machining point S changes due to any factor, provided the machining point S is positioned within the first Mach disk 33. Consequently, the auxiliary gas can be used effectively.

[0128] Furthermore, the control unit 112 determines an anomaly in the emitted jet by executing step S14. If the anomaly is a blockage, a gas shortage, or the like, the velocity V of the jet emitted from the ejection opening 28 hardly changes even if the supply pressure Ps from the auxiliary gas supply device 16 into the chamber has been changed.

[0129] This means that in this case the output data β of the measuring instrument 76 hardly change and this also occurs with a repeated execution of the loop of steps S21 to S22 in Fig. 15 not to β ≧ β th (that is, YES at step S12 in Fig. 15).

[0130] The control unit 112 acts as an anomaly detection unit 113 and determines that the output data β differ from the reference data if, despite a specified number m maxRepeated execution of the loop of steps S21 to S22 does not result in β ≧ β th comes, and gives in step S7 of Fig. 14 an alarm. This design allows the operator to intuitively recognize that an anomaly has occurred in the nozzle 24 or the auxiliary gas supply, and to replace the nozzle 24 or take action against the operational anomaly (for example, a gas shortage in) the auxiliary gas supply device 16.

[0131] A slight abnormality such as an error in the opening dimension of the ejection orifice 28 or the length in the z-axis direction, an inclination of the ejection orifice 28 with respect to the z-axis, an error in the plan dimension of the interior of the nozzle 24 (the chamber 29), or the like may cause a slight decrease in the velocity V of the jet ejected from the ejection orifice 28 from the reference value. In such a slight abnormality, the velocity of the jet changes according to a change in the supply pressure Ps, but it may be determined YES in step S13 even if β ≧ β is not obtained upon repeated execution of the feedback control in steps S9 to S13. th comes.

[0132] In the laser processing system 110, the control unit 112 continues the processing of the workpiece W when, in step S14, it reaches β ≧ β through the execution of step S21. thThis design allows the machining of the workpiece W to continue even if a minor anomaly such as a dimensional error or the like has caused the jet velocity V to fall below the reference value, by changing (specifically, increasing) the supply pressure Ps in a state where the jet is blown onto the machining point S at a sufficiently high velocity V.

[0133] Now, with each determination of YES in step S12 in a first laser processing process, the control unit 112 may sequentially store the distance d between the ejection port 28 and the processing location S at that time. Then, the control unit 112 may set the initial target position of step S1 in a second laser processing process performed subsequent to the first laser processing process based on the distance d stored in the first laser processing process. For example, the control unit 112 may also set an average value of the distances d stored in the first laser processing process or the most recently stored distance d as the initial target position of the second laser processing process.

[0134] As a modification of the laser processing system 110, the above-described measuring instrument 66 can be used instead of the measuring instrument 76. In this case, the measuring instrument 66 is configured to non-contact measure the beam velocity V at the position of the processing point S (or at a position slightly shifted from the position of the processing point S toward the ejection opening 28). The measuring instrument 66 used in the laser processing system 110, the arranging device 18, and the control unit 112 constitute the above-described beam monitoring device 60.

[0135] In the present modified example, the control unit 112 performs the operation described in Fig. 14 and Fig. 15 based on the output data α of the measuring instrument 66 instead of the output data β, and the workpiece W can be laser machined in a state in which the workpiece W has been placed in the first Mach disk area 33.

[0136] Next, with reference to Fig. 17 and Fig. 18 explains a laser processing system 120. The laser processing system 120 includes the laser oscillator 12, the laser processing head 14, the auxiliary gas supply device 16, the arranging device 18, the dummy workpiece 64, the measuring instrument 66, and a control unit 122.

[0137] The control unit 122 has a processor and a memory unit (not shown) and controls the laser oscillator 12, the laser processing head 14, the auxiliary gas supply device 16, the arrangement device 18, and the measuring instrument 66. The control unit 122 acts as the position acquisition unit 68 described above. That is, the arrangement device 18, the dummy workpiece 64, the measuring instrument 66, and the control unit 122 form the beam monitoring device 60 described above.

[0138] Next, the operation of the laser processing system 120 will be explained. First, the control unit 122 obtains information indicating the position x1 of the first maximum point 32. Specifically, the control unit 122 acts as a position acquisition unit 68 and obtains the position x1 from the first peak value α through the method explained in connection with the beam monitoring device 60 described above. max1the initial data α of the measuring instrument 66 the target distance d T .

[0139] Subsequently, the control unit 122 positions the nozzle 24 at the target position. Specifically, the control unit 122 acts as a motion control unit 108 and operates the positioning device 18, thereby moving the laser processing head 14 relative to the workpiece W and positioning the nozzle 24 at the target position, where the distance d between the ejection opening 28 and the processing point S is equal to the target distance d. T matches, is arranged.

[0140] Then, the control unit 122 operates the auxiliary gas supply device 16, and the auxiliary gas is supplied into the chamber 29 at the supply pressure Ps, and a jet of the auxiliary gas is ejected from the ejection port 28. Furthermore, the control unit 122 operates the laser oscillator 12, thereby emitting laser light from the ejection port 28, and operates the lens drive unit 23, thereby adjusting the position of the optical lenses 22 in the direction of the optical axis O so that the focal point of the emitted laser light is located at the processing position S.

[0141] In this state, the control unit 122 operates the arrangement device 18 according to a machining program and the workpiece W is laser-machined (laser-cut) while the nozzle 24 is moved relative to the workpiece W. The machining point S of the workpiece W is positioned in the first Mach disk area 33 of the auxiliary gas jet.

[0142] As described above, before machining the workpiece W, the control unit 122 obtains the position x1 of the first maximum point 32 by the beam monitoring device 60, and the workpiece W is laser machined in a state where the nozzle 24 has been positioned at the target position determined based on the obtained position x1 of the first maximum point 32. Since the machining point S can be positioned in the first Mach disk area 33 during machining of the workpiece by this embodiment, the assist gas can be effectively utilized.

[0143] In this laser machining system 120, even if the opening dimension ∅ of the ejection port 28 and the supply pressure Ps of the assist gas are unknown, the position x1 of the first maximum point 32 can be obtained before machining the workpiece W by the beam monitoring device 60, and the target position of the nozzle 24 can be set based on the position x1 of this first maximum point 32.

[0144] Next, with reference to Fig. 19 and Fig. 20 a laser processing system 130 is explained. The laser processing system 130 comprises the laser oscillator 12, the laser processing head 14, the auxiliary gas supply device 16, the arrangement device 18, the measuring instrument 84 and a control unit 132.

[0145] The control unit 132 comprises a processor and the memory unit 104 and controls the laser oscillator 12, the laser processing head 14, the auxiliary gas supply device 16, the arrangement device 18, and the measuring instrument 84. The database 106 shown in Table 1 above is stored in the memory unit 104. The control unit 132 acts as the position acquisition unit 86 described above. That is, the measuring instrument 84 and the control unit 132 form the beam monitoring device 80 described above.

[0146] Next, with reference to Fig. 21 explains the operation of the laser processing system 132. The one in Fig. The sequence shown in Figure 21 begins when the control unit 132 receives a command to begin processing from the operator, a higher-level control system, or a processing program. In the sequence shown in Figure 21, the following occurs: Fig. As shown in 21, the processes are the same as in the one in Fig. The sequence shown in step 14 is labelled with the same step numbers, and a repeated explanation is omitted.

[0147] After steps S1 and S2 have been executed, the control unit 132 begins in step S31 by measuring the supply flow rate Vv of the auxiliary gas supplied by the auxiliary gas supply device 16 to the chamber 29. Specifically, the control unit 132 sends a command to the measuring instrument 84, and the supply flow rate Vv is continuously measured by the measuring instrument 84 (for example, at a specific interval). The control unit 132 also begins measuring the distance d between the discharge opening 28 and the machining point S. As described above, the distance d can be obtained using a commonly known distance sensor or the like.

[0148] After step S4, the control unit 132 reaches the position x1 of the first maximum point 32 in step S32. Specifically, the control unit 132 acts as a position acquisition unit 86 and calculates the distance d using the output data Vv last obtained from the measuring instrument 84 and the formula 1 described above. c from the ejection opening 28 to the first maximum point 32 as information regarding the position x1 of the first maximum point 32.

[0149] In step S32, the control unit 132 determines whether there is a difference δ between the distance d and the distance d. c greater than a predefined threshold δ th is or is not. Specifically, the control unit 132 calculates the difference δ (= d - d c ) between the last measured distance d between the ejection opening 28 and the processing position S and the distance d obtained in the last step S32 c .

[0150] If the control unit 132 determines that the absolute value (|d - d c |) of the difference δ greater than the threshold δ th If the answer is yes, it proceeds to step S34. If, on the other hand, control unit 132 determines that the absolute value of the difference δ is at most the threshold value δ th If the threshold value is (that is, NO), it proceeds to step S15. This threshold value δ th is determined by the operator.

[0151] In step S34, the control unit 132 changes the target position of the nozzle 24. Specifically, the control unit 132 changes the target position of the nozzle 24 at the start of this step S34 to a new target position moved in the negative z-axis direction if the difference δ calculated in the last step S33 is positive.

[0152] The control unit 132 then acts as a motion control unit 108 and operates the positioning device 18, which moves the nozzle 24 in the negative z-axis direction to position it at the new target position. As a result, it brings the nozzle 24 closer to the workpiece W and reduces the distance d between the ejection opening 28 and the machining point S.

[0153] If the difference δ calculated in step S33 is a negative value, the control unit 132 changes the target position of the nozzle 24 at the start of step S34 to a new target position moved in the positive z-axis direction. The control unit 132 then acts as a motion control unit 108 and operates the positioning device 18, thereby moving the nozzle 24 in the positive z-axis direction to position it at the new target position. As a result, the nozzle 24 moves away from the workpiece W, and the distance d between the ejection opening 28 and the machining point S increases. After the execution of step S34, the control unit 132 returns to step S32.

[0154] If NO is determined in step S33, the control unit 132 executes step S15 described above, and if YES is determined, it sends a command to the laser oscillator 12, thereby stopping the laser oscillation operation and the Fig. The sequence shown in step 21 ends, while it returns to step S32 if NO is determined.

[0155] In this way, in the laser processing system 130, the target position of the nozzle 24 is changed on the basis of the position x1 of the first maximum point 32 obtained during laser processing by the beam monitoring device 80, feedback control of the arrangement device 18 is carried out according to the changed target value, and the nozzle 24 is moved.

[0156] This means that the target position of the nozzle 24 is determined based on the position x1 of the first maximum point 32 as a specific range (a range that 0 ≤ δ 5 δ thfulfilled). Through the feedback control, the processing point can be continuously positioned in the first Mach disk area 33 during the processing of the workpiece W. That is, the first Mach disk area 33 in the laser processing system 130 can be defined as the perimeter of an area in which the distance δ from the position x1 of the maximum point 32 0 ≤ δ ≤ δ th fulfilled, defined.

[0157] In the laser processing system 130, the workpiece W can be laser processed even if the distance d between the ejection opening 28 and the processing point S changes due to any factor, provided the processing point S is located in the first Mach disk 33. Consequently, the auxiliary gas can be used effectively.

[0158] Next, with reference to Fig. 22 explains a jet control device 140. The jet control device 140 is a device that regulates the positions x1, x2 of the maximum points 32, 34 of the jet ejected from the ejection opening 28 of the nozzle 24, and includes a casing 142 and a casing drive unit 144. The casing 142 is a tubular member having an inner dimension in the radial direction.

[0159] The bezel 142 is formed from a flexible tubular member with a radius R as its inner dimension in the radial direction. This tubular member is, for example, a wool material, a resin material, or a rubber material. The bezel 142 is arranged approximately concentrically with the ejection port 28 with respect to the optical axis O. It has one end 142a in the negative z-axis direction and one end 142b on the side opposite the end 142a.

[0160] End 142a is positioned on the mounting surface of the workpiece table 38. End 142b is located at a position away from the ejection opening 28 in the positive z-axis direction. In other words, the frame 142 has a sufficiently long length in the z-axis direction that end 142b is always positioned at a distance from the ejection opening 28 in the positive z-axis direction during laser processing.

[0161] The edging drive unit 144 comprises a mechanism 146 that deforms the edging 142 such that the radius R of the edging 142 is changed, and a drive unit 148 that generates the driving force for this mechanism 146. Various embodiments are conceivable for the edging 142, whose radius R is variable, and the mechanism 146. These are described below with reference to Fig. 23 and Fig. 24 examples of the edging 142 and the mechanism 146 are explained. In Fig. 23 and Fig. For ease of understanding, border 142 is shown with a dashed line on 24.

[0162] The Fig. The mechanism 146A shown in Figure 23 is a so-called iris mechanism used in a camera or the like. Specifically, the mechanism 146A includes a plurality of vanes 150 and is driven to move inward in the radial direction with the circumferential rotation of these vanes 150. The bezel 142 is coupled to the inner edge of the plurality of vanes 150 and is deformed to reduce and increase its diameter in conjunction with the operation of these vanes. The driving force unit 148 includes, for example, a servo motor and drives the mechanism 146A, thereby reducing and increasing the diameter of the bezel 142.

[0163] The Fig. The mechanism 146B shown in Figure 24 has an arm section 152 extending circumferentially around the optical axis O and a gear 156 formed at an intersection area 154 of the arm section 152. Tooth sections are formed on the circumferential surfaces of the arm section 152, opposing each other at the intersection area 154, and the gear 156 engages with these tooth sections. The frame 142 is connected to the inner circumference of the arm section 152, except for the intersection area 154.

[0164] In the state that is in Fig. 24(a), the length in the circumferential direction of the intersecting portion 154 of the arm portion 152 is large, and a slack portion 158 is formed on the skirt 142. In the course of rotation of the gear 156 from the position shown in Fig. In the state shown in 24(a), the overlap area 154 of the arm section 152 decreases in one direction, and in connection with this, the slack area 158 of the edging is gradually pulled in the circumferential direction and the edging 142 becomes the one shown in Fig. 24(b) shown state.

[0165] Conversely, the overlap area 154 of the arm section 152 increases during a rotation of the gear 156 in the other direction, and in connection with this, the loose area 158 of the rim 142 gradually increases, and the rim 142 becomes the one described in Fig. The state shown in 24(a) is reduced. The drive unit 148, for example, has a servo motor and reduces and enlarges the frame 142 by rotating the gear 156.

[0166] With further reference to Fig. 22, the beam regulating device 140 can adjust the position x1 of the first maximum point 32 and the position x2 of the second maximum point 34 by changing the radius R of the enclosure 142. The principle according to which the positions x1, x2 of the maximum points 32, 34 can be adjusted is explained below.

[0167] As described above, the auxiliary gas ejected from the ejection port 28 is reflected at the boundary with the air on the outside, forming Mach disks in the jet. When the enclosure 142 is installed, the air layer located between the jet and the enclosure 142 is forced by the jet, and the particle density of this air layer increases.

[0168] When the auxiliary gas is reflected at the boundary of the thus compressed air layer, the reflection angle and the reflection position of the auxiliary gas change and the positions of the Mach disks formed in the beam (i.e., the positions x1, x2 of the maximum points 32, 34) change compared to the case where there is no enclosure 142.

[0169] When the inner dimension of the enclosure 142 is changed, the volume and particle density of the air layer between the beam and the enclosure 142 change, and this can alter the positions of the Mach disks formed in the beam. The beam regulating device 140 regulates the positions x1, x2 of the maximum points 32, 34 in the direction of the optical axis O using the principle described above.

[0170] Specifically, the beam regulating device 140 changes the positions x1, x2 of the maximum points 32, 34 by shrinking the bezel 142 toward the downstream side of the beam (that is, along the optical axis in the direction away from the ejection opening 28). On the other hand, the beam regulating device 140 changes the positions x1, x2 of the maximum points 32, 34 by expanding the bezel 142 toward the upstream side of the beam.

[0171] According to the beam regulating device 140, the positions x1, x2 of the maximum points 32, 34 can be regulated by changing the inner dimension (radius R) of the bezel 142 during workpiece machining depending on fluctuations in the distance d between the ejection opening 28 and the machining point S so that the machining point S is arranged in the first Mach disk area 33.

[0172] And if the enclosure 142 is reduced in a state where the supply pressure Ps into the chamber 29, which is formed inside the nozzle 24 with the specified opening dimension Ø, is kept constant, the positions x1, x2 of the maximum points 32, 34 are shifted towards the downstream side of the jet, and the jet velocity V at positions x1, x2 is increased. That is, it is possible to increase the jet velocity V in the Mach disk areas 33, 35, where the workpiece W is located, without changing the supply pressure Ps.

[0173] In other words, the jet velocity V in the Mach disk regions 33, 35 can be maintained by reducing the size of the rim 142 even when the supply pressure Ps is reduced. Since this design reduces the amount of auxiliary gas consumed, costs can be lowered. It is also possible to omit the rim drive unit 144 and manually adjust the inner dimensions of the rim 142.

[0174] Next, with reference to Fig. 25 and Fig. 26 a laser processing system 160 is explained. The laser processing system 160 comprises the laser oscillator 12, the laser processing head 14, the auxiliary gas supply device 16, the arrangement device 18, the measuring instrument 84, the beam regulation device 140 and a control unit 162.

[0175] The control unit 162 includes a processor and the storage unit 104 and controls the laser oscillator 12, the laser processing head 14, the auxiliary gas supply device 16, the arranging device 18, the measuring instrument 84, and the beam regulation device 140 (specifically, the driving force unit 148). The storage unit 104 stores the database 106 shown in Table 1 above. The control unit 162 functions as the position acquisition unit 86 described above. That is, the measuring instrument 84 and the control unit 162 constitute the beam monitoring device 80 described above.

[0176] Next, with reference to Fig. 27 explains the operation of the laser processing system 160. The one in Fig. The sequence shown in 27 begins when the control unit 162 receives a command to start processing from the operator, a higher-level control unit, or a processing program. In the sequence shown in Fig. As shown in 27, the processes are the same as in the one in Fig. The sequence shown in step 21 is labelled with the same step numbers, and a repeated explanation is omitted.

[0177] After the start of the in Fig. In the sequence shown in 27, the control unit 162 performs the same steps S1 to S33 as in the sequence shown in Fig. As shown in 21, if YES is determined in step S33, the control unit 162 controls the position x1 of the first maximum point 32 in step S41. Specifically, the control unit 162 then sends when the difference δ (= d - d c Since the value calculated in the immediately preceding step S33 is positive, a command is sent to the drive unit 168 of the edging drive unit 144, thereby reducing the inner dimension (the radius R) of the edging 142. This shifts the position x1 of the first maximum point 32 towards the downstream side of the beam.

[0178] If, on the other hand, the difference δ calculated in the immediately preceding step S33 is a negative value, the control unit 162 operates the edging drive unit 144 and the inner dimension (the radius R) of the edging is increased. This shifts the position x1 of the first maximum point 32 towards the upstream side of the beam.

[0179] In this way, the control unit 162 acts as the maximum point control unit 164, which controls the position x1 of the first maximum point 32 by changing the inner dimension of the enclosure 142 based on the information regarding the position x1 of the first maximum point 32 obtained by the position acquisition unit 86 in step S32. After executing step S41, the control unit 162 returns to step S32.

[0180] The laser processing system 160 allows the processing point S of the workpiece W to be continuously positioned within the first Mach disk area 33 during laser processing by changing the inner dimension of the housing 142, without moving the nozzle 24. This design allows the workpiece W to be laser processed even if the distance d between the ejection opening 28 and the processing point S changes due to any factor, provided the processing point S remains within the first Mach disk 33. Consequently, the auxiliary gas can be used effectively.

[0181] In the laser processing system 160, the storage unit 104 can also store a database containing several target distances. Tin a correlation with the opening dimension Ø of the nozzle 24, the supply pressure Ps and the inner dimension (the radius R) of the housing 142. If the control unit 162 in this case uses the opening dimension Ø and the supply pressure PS as well as the distance d calculated in step S32 as the target position distance d in step S41 described above. T Applying this to the database, the target internal dimension of the frame 142 can be determined.

[0182] Then, in step S14, the control unit 162 operates the edging drive unit 144 and changes the inner dimension of the edging 142 to the target inner dimension determined from the database. This allows the machining point S to be positioned with high accuracy in the first Mach disk area 33.

[0183] It is also possible to Fig. The sequence shown in Figure 27 is to be carried out on the laser processing system 130 described above. In this case, the control unit 132 can control the positions x1, x2 of the maximum points 32, 34 in step S41 by changing the supply pressure Ps to the chamber 29. If the supply pressure Ps to the chamber 29 is increased, the positions x1, x2 of the maximum points 32, 34 shift towards the downstream side of the beam (that is, in a direction away from the ejection aperture 28 along the optical axis O).

[0184] If, on the other hand, the supply pressure Ps to chamber 29 is reduced, the positions x1, x2 of the maximum points 32, 34 shift towards the upstream side of the beam (that is, in a direction leading along the optical axis O towards the ejection aperture 28). If the difference δ (= d - d cIf the value calculated in the immediately preceding step S33 is positive, the control unit 132 sends a command to the auxiliary gas supply device 16 in step S41, thereby increasing the supply pressure Ps. This shifts the position x1 of the first maximum point 32 to the downstream side of the jet.

[0185] On the other hand, if the difference δ calculated in the immediately preceding step S33 is a negative value, the control unit 132 sends a command to the auxiliary gas supply device 16, thereby reducing the supply pressure Ps. As a result, the position x1 of the first maximum point 32 shifts to the upstream side of the jet. In this way, the control unit 132 acts as a maximum point control unit that controls the position x1 of the first maximum point 32 by changing the supply pressure Ps based on the information regarding the position x1 of the first maximum point 32 acquired by the position acquisition unit 86 in step S32.

[0186] The positioning device 18 is not limited to the structure described above, but may, for example, also include a workpiece table movable along the xy plane and a z-axis movement mechanism that moves the nozzle 24 along the z-axis. Alternatively, the positioning device may not include a movement mechanism but be configured such that the nozzle 24 is simply fixed by hand at any position relative to the workpiece W.

[0187] For the dummy workpiece 64 and the measuring instrument 66 of the in Fig. The beam monitoring device 60 shown in section 4 comes in various forms. The following are described with reference to... Fig. 28 and Fig. 29 examples are explained for the dummy workpiece 64 and the measuring instrument 66. In the example that is in Fig. As shown in Figure 28, the dummy workpiece 64 has a round through-hole 64b formed at a position corresponding to the dummy machining point 64a described above. The opening dimension of this through-hole 64b is set such that it is approximately equal to the presumed opening dimension of a through-hole formed when a workpiece W is drilled through with the laser light emitted from the nozzle 24.

[0188] The measuring instrument 66 comprises a pair of column sections 170 and a hot wire 172. The two column sections 170 extend from a surface 64c of the dummy workpiece 64 along the positive z-axis direction and are arranged opposite each other. The hot wire 172 is stretched in a straight line between the pair of column sections 170, and its resistance changes depending on the velocity V of the beam ejected from the ejection aperture 28.

[0189] Here, the length L of the hot wire 172 located between the two column sections 170 (that is, the distance between the two column sections 170) can be adjusted so that, for example, it is at most the opening dimension Ø of the ejection opening 28 or at most the inner dimension of the through-opening 64b. Alternatively, the hot wire 172 can be made of a material with high rigidity. By adjusting it to a short length or by making the hot wire 172 from a material with high rigidity, it can be prevented from bending when the hot wire 172 is positioned in the jet.

[0190] The distance from the surface 64c of the dummy workpiece 64 to the hot wire 172 can, for example, be set to a maximum of 0.5 mm. If the distance from the surface 64c to the hot wire 172 is set so small, the velocity V of the beam can be measured at a position close to the processing point S of the workpiece W during laser processing.

[0191] In the Fig. In the example shown in Figure 29, the measuring instrument 66 has a hot wire 174 stretched across the through-hole 64b. The length L of the hot wire 174 corresponds to the opening dimension of the through-hole 64b. The hot wire 174 is positioned at a location on the surface 64c of the dummy workpiece 64. By arranging the hot wire 174 in this way, the velocity V of the beam can be measured at a position close to the processing point S of the workpiece W during laser processing. As described above, the measuring instruments 66 of Fig. 28 and Fig. 29 hot-wire anemometers.

[0192] In the embodiments described above, the workpiece W can also be arranged in the second Mach disk area 35 (second maximum point 34) or at an nth Mach disk area (where n is an integer of at least 3) during machining. Instead of the beam monitoring devices 60, 70, 80 described above, an image such as can be acquired, for example, by a high-speed camera. Fig. 2 can be recorded, and the positions x1, x2 of the maximum points 32, 34 can be measured based on this image.

[0193] The ejection opening 28 is not limited to a round shape, but can have any shape, such as a polygonal or oval shape, or the like. The features of the various embodiments described above can also be combined with one another. For example, the beam monitoring device 80 can be combined with the laser processing system 110 or 120, and the beam regulation device 140 can be combined with the laser processing system 110 or 120.

[0194] The present disclosure has been explained above by means of embodiments, but the embodiments described above do not limit the invention according to the claims.

Claims

[1] Laser processing system (110), comprising: a nozzle (24) having an ejection opening (28) which ejects a jet of an auxiliary gas along the optical axis (O) of the laser light, the nozzle (24) forming a maximum point of the speed of the jet at a position remote from the ejection opening (28); a measuring instrument (66, 76) which measures one of the speed of the beam and a noise caused by an impact of the beam on a workpiece; and an abnormality determination unit (113) that determines whether or not the output data of the measuring instrument (66, 76) differs from reference data, wherein the reference data indicates, as information representing a position of the maximum point of the velocity, a peak value of the output data continuously measured by the measuring instrument (66, 76) along the jet ejected from the nozzle (24) in a normal state. [2] The laser processing system (110) according to claim 1, wherein the abnormality determination unit (113) determines whether the output data has entered a range determined based on the reference data after the nozzle (24) and the workpiece (W) have been relatively moved, and determines that the output data is different from the reference data when the output data is out of the range. [3] Laser processing system (110) according to claim 2, further comprising: a position obtaining unit (78) which obtains information indicating the position of the maximum point based on the output data; a movement mechanism (40, 42, 44) which moves the nozzle (24) and the workpiece (W) relative to each other; and a motion control unit (108) which controls the motion mechanism (40, 42, 44) and arranges the nozzle (24) with respect to a processing point (S) of the workpiece (W) at a target position determined on the basis of the information, wherein the motion control unit (108) performs feedback control of the motion mechanism (40, 42, 44) according to the target position, wherein the abnormality determination unit (113) determines, after execution of the feedback control, whether the output data measured by the measuring instrument (66, 76) has entered the range or not. [4] The laser processing system (110) according to claim 3, further comprising a pressure regulating unit (115) that changes the supply pressure of the assist gas to the nozzle (24) when it is determined by the abnormality determining unit (113) that the output data is out of the range, wherein the abnormality determining unit (113) again determines whether the output data measured by the measuring instrument (66, 76) has entered the range or not after a change in the supply pressure by the pressure regulating unit (115). [5] The laser processing system (110) according to claim 4, wherein the pressure regulating unit (115) repeatedly changes the supply pressure with each determination by the abnormality determining unit (113) that the output data is out of the range after the pressure regulating unit (115) changes the supply pressure, and the abnormality determining unit (113) determines whether the output data has come into the range or not with each change in the supply pressure by the pressure regulating unit. [6] The laser processing system (110) according to claim 5, wherein the pressure regulating unit (115) further comprises a warning generating unit (118) that generates a warning when, after the supply pressure is changed by the pressure regulating unit (115) for a predetermined number of times, the output data is determined to be out of range by the abnormality determining unit (113). [7] Laser processing system (110), comprising: a nozzle (24) having an ejection opening (28) which ejects a jet of an auxiliary gas along the optical axis (O) of the laser light, the nozzle (24) forming a maximum point of the speed of the jet at a position remote from the ejection opening (28); a measuring instrument (66, 76) that measures one of the speed of the beam and a noise caused by an impact of the beam on a workpiece; an anomaly determination unit (113) which determines whether the output data of the measuring instrument (66, 76) differs from reference data or not, wherein the abnormality determination unit (113) determines whether the output data has entered a range determined based on the reference data after the nozzle (24) and the workpiece (W) have been relatively moved, and determines that the output data differs from the reference data when the output data is outside the range; a position obtaining unit (78) which obtains information indicating the position of the maximum point based on the output data; a moving mechanism (40, 42, 44) that moves the nozzle (24) and the workpiece (W) relative to each other; a movement control unit (108) that controls the movement mechanism (40, 42, 44) and arranges the nozzle (24) with respect to a processing location (S) of the workpiece (W) at a target position determined on the basis of the information, wherein the movement control unit (108) performs feedback control of the movement mechanism (40, 42, 44) according to the target position, wherein the abnormality determination unit (113) determines, after execution of the feedback control, whether the output data measured by the measuring instrument (66, 76) has entered the range or not; and a pressure regulating unit (115) which changes the supply pressure of the auxiliary gas to the nozzle (24), when the abnormality determination unit (113) determines that the output data is out of the range, wherein the abnormality determination unit (113) determines again whether or not the output data measured by the measuring instrument (66, 76) has entered the range after a change in the supply pressure by the pressure regulating unit (115). [8] A method for laser machining a workpiece (W) using the laser machining system (110) according to any one of claims 1 to 7, wherein on the basis of the initial data, information indicating the position of a maximum point is obtained; in a state in which the nozzle (24) has been arranged at a target position determined on the basis of the information with respect to a processing location (S) of the workpiece (W), a beam is ejected from the ejection opening (28) of the nozzle (24) and the workpiece (W) is processed by laser light; and determines whether the source data differs from reference data or not.

Images