Laser cutting device and laser position adjustment method

Abstract

A laser cutting device according to the present invention is to perform laser cutting of a workpiece and comprises a laser beam irradiation unit that emits a laser, a laser nozzle that has an internal passage along which the laser passes and can irradiate the laser at the workpiece from a tip end opening part that is provided on the tip end side in the optical axis direction of the laser, an acquisition unit that can acquire the outline of the laser that passes through the tip end opening part and the outline of the tip end opening part, and a control unit that calculates a positional deviation amount for the optical axis of the laser relative to the tip end opening part on the basis of the outline of the laser and the outline of the tip end opening part.

Description

Laser cutting device and laser position adjustment method

[0001] This application claims priority to Japanese Patent Application No. 2024-068333, filed on April 19, 2024, the contents of which are incorporated herein by reference.

[0002] Conventionally, laser cutting devices that irradiate a workpiece with a laser to cut it are known. In laser cutting devices, a laser beam, the focus of which is controlled by passing it through a condenser lens, is irradiated onto the workpiece from the tip opening of a laser nozzle provided at the tip of a laser processing head.

[0003] In laser cutting devices, a centering adjustment is performed as a preparatory step before cutting to align the optical axis of the laser with the axial center of the laser nozzle. In the centering adjustment step, for example, a centering sheet is attached to the tip of the laser nozzle, to which graphite or the like is attached, and in that state, a laser is irradiated to form a through hole in the centering sheet.

[0004] After the through-holes are formed in the centering sheet, the centering sheet is removed from the laser nozzle. The worker visually checks the alignment of the trace of the laser nozzle tip opening formed on the centering sheet by graphite or the like attached to the tip of the laser nozzle and the through-holes formed in the centering sheet by the laser, and confirms whether the optical axis of the laser and the axial center of the laser nozzle are aligned.

[0005] If the optical axis of the laser does not coincide with the axial center of the laser nozzle, the worker changes the position of the focusing lens or laser nozzle, then visually checks again using the centering sheet, and repeats these adjustments until the optical axis of the laser and the axial center of the laser nozzle coincide.

[0006] In addition, a laser processing device described in Patent Document 1 includes an imaging unit that images the tip opening of the laser nozzle and the irradiation area of ​​the laser light on the workpiece, an optical branching element that reflects first incident light from the laser oscillator toward the workpiece and transmits second incident light from the workpiece so that it enters the imaging unit, and an adjustment unit that makes adjustments to correct the misalignment between the center of the tip opening of the laser nozzle and the center of the laser light based on image data obtained by imaging the tip opening of the laser nozzle and the irradiation area.

[0007] Japanese Patent No. 7053338

[0008] However, in the visual centering adjustment work using a centering sheet, the worker needs to visually judge a positional deviation of several tens of micrometers, which requires a high level of technical skill. Also, the laser processing device described in Patent Document 1 needs to have a beam splitter (light branching element) inside the laser processing head, which may complicate the structure of the laser processing head and may make it difficult to maintain.

[0009] In consideration of the above circumstances, an object of the present disclosure is to provide a laser cutting device and a laser position adjustment method that can efficiently adjust the position of a laser.

[0010] A laser cutting device according to a first aspect of the present disclosure is a laser cutting device that laser cuts a workpiece, and includes a laser beam irradiation unit that emits a laser, a laser nozzle that has an internal passage through which the laser passes and is capable of irradiating the laser onto the workpiece from a tip opening provided on the tip side in the optical axis direction of the laser, an acquisition unit that is capable of acquiring the outline of the laser passing through the tip opening and the outline of the tip opening, and a control unit that calculates the amount of positional deviation of the optical axis of the laser relative to the tip opening based on the outline of the laser and the outline of the tip opening.

[0011] A laser position adjustment method according to a second aspect of the present disclosure is a laser position adjustment method for a laser cutting device comprising: a laser beam irradiation unit that emits a laser; and a laser nozzle that has an internal passage through which the laser passes and is capable of irradiating the laser onto a workpiece from a tip opening provided on the tip side in the optical axis direction of the laser, and comprises a laser contour acquisition step that acquires the contour of the laser passing through the tip opening; a nozzle contour acquisition step that acquires the contour of the tip opening; and a positional deviation amount calculation step that calculates the positional deviation amount of the optical axis of the laser relative to the tip opening based on the contour of the laser and the contour of the tip opening.

[0012] According to the laser cutting device and laser position adjustment method of the present disclosure, it is possible to provide a laser cutting device and a laser position adjustment method that can efficiently adjust the position of a laser.

[0013] 1 is a diagram schematically showing a laser cutting device according to an embodiment; FIG. 2 is a diagram showing a tip opening of a laser nozzle provided in the laser cutting device; FIG. 3 is a flowchart showing a laser position adjustment method according to an embodiment; FIG. 4 is a photograph showing an example of an acquisition result in a laser contour acquisition step in the laser position adjustment method; FIG. 5 is a photograph showing an example of an acquisition result in a nozzle contour acquisition step in the laser position adjustment method; FIG. 6 is a photograph showing an example of a laser contour and a nozzle contour before a position adjustment step in the laser position adjustment method; and FIG. 7 is a photograph showing an example of a laser contour and a nozzle contour after a position adjustment step in the laser position adjustment method.

[0014] Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings.

[0015] FIG. 1 is a diagram schematically illustrating a laser cutting device 100 according to this embodiment.

[0016] In this embodiment, as shown in FIG. 1, the X-axis, Y-axis, and Z-axis are perpendicular to each other, and the X-axis is defined as the horizontal front-rear direction, the Y-axis is defined as the horizontal left-right direction, and the Z-axis is defined as the vertical up-down direction.

[0017] The laser cutting device 100 includes a laser processing head 10 , a laser irradiation device 20 , an assist gas supply unit 30 , a servo control unit 40 , a control unit 50 , and an acquisition unit 60 .

[0018] The laser cutting device 100 is a laser cutting device that laser-cuts a processing target portion H of a processing target object W by using a laser LA irradiated from a laser irradiation device 20.

[0019] In the following description, the direction in which the optical axis of the laser LA extends will be referred to as the “optical axis direction,” the side on which the workpiece is provided will be referred to as the “tip side” in the optical axis direction, and the side opposite the tip side in the optical axis direction will be referred to as the “base side.” In this embodiment, the optical axis direction of the laser LA coincides with the Z-axis direction.

[0020] The laser processing head 10 includes a laser nozzle 10A, a torch portion 10B, and a support body 10C.

[0021] The laser nozzle 10A includes a tapered portion 10T and a straight portion 10S. The laser nozzle 10A is formed of a material containing copper, for example.

[0022] The tapered portion 10T is a hollow truncated cone-shaped member whose diameter decreases toward the tip side in the optical axis direction of the laser LA. The tapered portion 10T does not need to be strictly truncated cone-shaped.

[0023] The straight portion 10S is a cylindrical member connected to the tip side of the tapered portion 10T. The straight portion 10S does not need to be strictly cylindrical.

[0024] The internal space of the tapered portion 10T and the internal space of the straight portion 10S are connected to each other, forming an internal passage OP of the laser nozzle 10A. The internal passage OP is a passage through which the laser LA passes, and is an area surrounded by the inner peripheral surface S of the laser nozzle 10A.

[0025] A tip opening TO, which is in communication with the internal passage OP, is formed at the tip T of the straight portion 10S. The laser LA that has passed through the internal passage OP is irradiated from the tip opening TO toward the workpiece W.

[0026] The torch portion 10B is a cylindrical member connected to the base end of the tapered portion 10T. The torch portion 10B does not necessarily have to be cylindrical in shape. The internal space of the torch portion 10B communicates with the internal passage OP of the laser nozzle 10A.

[0027] The support 10C is connected to the base end (not shown) of the torch part 10B. The laser processing head 10 can be moved to any position by changing the position of the support 10C using a servo control part 40, which will be described later.

[0028] The laser irradiation device 20 includes a laser oscillator 21 , a laser beam irradiation unit 22 , a collimator lens 23 , a condenser lens 24 , and a protective glass 25 .

[0029] The laser oscillator 21 generates a laser beam of a predetermined output and sends it to the laser beam irradiation unit 22. In this embodiment, the laser oscillator 21 generates a cutting laser beam LA1 such as a fiber laser capable of cutting the workpiece W, and a positioning laser beam LA2 capable of illuminating the workpiece W without cutting it, and sends them to the laser beam irradiation unit 22.

[0030] In this embodiment, the optical axis of the cutting laser LA1 is the same as the optical axis of the positioning laser LA2. Furthermore, when there is no particular distinction between the cutting laser LA1 and the positioning laser LA2, the cutting laser LA1 and the positioning laser LA2 will be simply referred to as laser LA.

[0031] The laser beam irradiation unit 22 carries the laser LA to the end opposite to the end connected to the laser oscillator 21 and radiates the laser LA to the collimator lens 23 .

[0032] The collimating lens 23 corrects the traveling direction of the laser LA emitted from the laser beam irradiation unit 22 to form parallel collimated light. The laser LA that has passed through the collimating lens 23 is irradiated onto a condenser lens 24 that is provided closer to the base end than the laser processing head 10 in the traveling direction (optical axis direction) of the laser LA.

[0033] The condenser lens 24 condenses the laser beam LA, the traveling direction of which has been corrected by the collimator lens 23. The laser beam LA condensed by the condenser lens 24 enters the laser processing head 10 from the base end side of the torch portion 10B, passes through the internal passage OP of the laser nozzle 10A, and is irradiated onto the workpiece W from the tip opening TO.

[0034] The condenser lens 24 converges the laser LA onto a processing target location H of the processing target W. When the laser LA irradiated onto the processing target location H is the cutting laser LA1, the processing target location H is heated by the cutting laser LA1 and melts.

[0035] When the laser LA irradiated onto the processing target area H is the positioning laser LA2, the processing target area H is illuminated by the positioning laser LA2.

[0036] The protective glass 25 is provided on the optical axis of the laser LA between the condenser lens 24 and the laser processing head 10, and transmits the laser LA emitted from the condenser lens 24. The protective glass 25 protects the condenser lens 24 from fumes, spatters, etc. that fly off from the workpiece W during laser cutting with the cutting laser LA1.

[0037] The assist gas supply unit 30 is connected to the laser processing head 10. The assist gas supply unit 30 supplies oxygen gas, inert gas, or the like to the laser processing head 10. The oxygen gas, inert gas, or the like supplied from the assist gas supply unit 30 is supplied to the processing target location H of the processing object W via the laser processing head 10.

[0038] The assist gas, such as oxygen gas or inert gas, supplied to the processing target area H blows away the portion of the processing target area H that has been melted by the cutting laser LA1.

[0039] The servo control unit 40 is connected to the support 10C of the laser processing head 10. The servo control unit 40 controls the position of the laser processing head 10.

[0040] For example, the servo control unit 40 moves the laser processing head 10 in the Z-axis direction to change the distance in the Z-axis direction between the laser processing head 10 and the workpiece W. In addition, by changing the position of the laser processing head 10 in the X-axis direction or the Y-axis direction using the servo control unit 40, the laser processing head 10 can be moved in the cutting direction of the workpiece W.

[0041] The control unit 50 controls a part or the whole of the laser cutting device 100 .

[0042] The control unit 50 controls the laser irradiation device 20, and controls the generation of the laser beam LA by the laser oscillator 21, the output of the generated laser beam LA, the position of the condenser lens 24, etc. For example, the control unit 50 changes the position of the condenser lens 24 to change the focal position P of the laser beam LA.

[0043] The control unit 50 controls the assist gas supply unit 30 and controls the pressure, flow rate, concentration, etc. of the gas supplied from the assist gas supply unit 30 to the laser processing head 10 .

[0044] The control unit 50 controls the servo control unit 40 to control the position of the laser processing head 10 or the cutting path along which the laser processing head 10 moves to cut the workpiece W, etc.

[0045] The control unit 50 is a programmable device (computer) equipped with, for example, a processor, a memory, a storage unit, etc. Each function of the control unit 50 is realized by one or more processors, such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), executing a program stored in a program memory. However, all or part of these functions may be realized by hardware (e.g., circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a PLD (Programmable Logic Device). Furthermore, all or part of the above functions may be realized by a combination of software and hardware. The storage unit is realized by, for example, a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a ROM (Read-Only Memory), or a RAM (Random Access Memory).

[0046] The acquisition unit 60 can acquire the contour of the laser LA and the contour of the tip opening TO of the laser nozzle 10 A. The acquisition unit 60 includes, for example, an imaging device such as a camera that captures an image of the tip opening TO of the laser nozzle 10 A from the tip side and captures an image of the contour of the laser LA passing through the tip opening TO and the contour of the tip opening TO.

[0047] The acquisition unit 60 is not limited to an imaging device as long as it can acquire the outline of the laser LA and the outline of the tip opening TO of the laser nozzle 10A.

[0048] In the following description, the contour of the laser LA will also be referred to as the "laser contour," and the contour of the tip opening TO of the laser nozzle 10A will also be referred to as the "nozzle contour."

[0049] FIG. 2 is a diagram showing the tip opening TO of the laser nozzle 10A.

[0050] In this embodiment, the contour (nozzle contour) of the tip opening TO indicates the inner periphery Ta at the tip T of the straight portion 10S in a plan view from the tip side in the optical axis direction of the laser LA. A center point C shown in FIG. 2 indicates the center point of the inner periphery Ta (nozzle contour).

[0051] The acquisition unit 60 is connected to the control unit 50 wirelessly or via a wire, and is controlled by the control unit 50. The acquisition unit 60 also transmits data (e.g., image data) indicating the acquired laser contour and nozzle contour to the control unit 50.

[0052] Next, a description will be given of a method for adjusting the laser position by the control unit 50. Fig. 3 is a flowchart showing a method for adjusting the laser position in the laser cutting device 100.

[0053] The laser position adjustment method according to this embodiment is a method for adjusting the position of the optical axis of the laser LA and the tip opening TO of the laser nozzle 10A, when the laser LA is irradiated onto the processing target area H from the tip opening TO.

[0054] In the laser position adjustment method according to this embodiment, the control unit 50 adjusts the position of the optical axis of the laser LA relative to the tip opening TO so that it is positioned in a predetermined manner. The predetermined position of the optical axis of the laser LA relative to the tip opening TO is a position that is set in advance based on, for example, the material, shape, etc. of the workpiece W.

[0055] In the following description, the predetermined position of the optical axis of the laser LA relative to the tip opening TO will also be referred to as the "laser reference position."

[0056] In the laser position adjustment method described below, the laser reference position is the center point C of the nozzle contour, but the laser reference position is not limited to this.

[0057] When carrying out the laser position adjustment method described below, the workpiece W is not placed on the optical axis of the laser LA.

[0058] (Step S1) First, the control unit 50 performs step S1 (laser contour acquisition step). In step S1, the control unit 50 controls the acquisition unit 60 to acquire the contour of the laser LA (laser contour).

[0059] For example, the control unit 50 controls the laser irradiation device 20 to irradiate the positioning laser LA2. The acquisition unit 60 captures an image of the tip opening TO of the laser nozzle 10A from the tip side in the optical axis direction of the positioning laser LA2 and acquires the laser contour of the positioning laser LA2 irradiated from the tip opening TO. The acquisition unit 60 transmits the acquired laser contour to the control unit 50.

[0060] The laser cutting device 100 performs laser cutting using the cutting laser LA1 after adjusting the laser position using, for example, the laser position adjustment method illustrated in Fig. 3. The laser position adjustment method illustrated in Fig. 3 is an adjustment operation performed before laser cutting the workpiece W.

[0061] The optical path and focal position of the positioning laser LA2 irradiated by the laser irradiation device 20 in step S1 are preferably the same as the optical path and focal position of the cutting laser LA1 in the laser cutting performed after adjusting the laser position.

[0062] 4 is a photograph showing an example of the acquisition result in the laser contour acquisition step S1. The acquisition result shown in FIG. 4 is a photograph including the laser contour captured by the acquisition unit 60.

[0063] In step S1, if the laser nozzle 10A is located outside the acquisition range (e.g., the imaging range) of the acquisition unit 60, the control unit 50 may control the servo control unit 40 to move the laser processing head 10 so that the laser nozzle 10A is located within the acquisition range of the acquisition unit 60.

[0064] (Step S2) Next, the control unit 50 performs step S2 (nozzle contour acquisition step). In step S2, the control unit 50 controls the acquisition unit 60 to acquire the contour (nozzle contour) of the tip opening TO of the laser nozzle 10A.

[0065] For example, the acquisition unit 60 captures an image of the inner circumference Ta of the tip opening TO of the laser nozzle 10A from the tip side in the optical axis direction of the laser LA, and acquires the nozzle contour.

[0066] At this time, the control unit 50 may control the laser irradiation device 20 to irradiate the positioning laser LA2. By capturing an image of the tip opening TO illuminated by the positioning laser LA2, the acquisition unit 60 can acquire image data in which the nozzle outline is captured more clearly than when the tip opening TO is not illuminated by the positioning laser LA2.

[0067] In step S2, the acquisition unit 60 may capture an image of the tip opening TO under acquisition conditions different from those in step S1.

[0068] The control unit 50 sets, for example, the exposure time or filter when the acquisition unit 60 captures the laser contour and the nozzle contour, and the arrangement of the focal position P of the laser LA, as acquisition conditions when the acquisition unit 60 acquires the laser contour and the nozzle contour. The filter setting of the acquisition unit 60 refers to, for example, the setting of the optical density (OD value) of the filter that the acquisition unit 60 has.

[0069] In step S1, the control unit 50 controls the laser irradiation device 20 or the acquisition unit 60, and sets the exposure time or filter of the acquisition unit 60 and the focal position of the positioning laser LA2 so that the laser contour is clearly captured.

[0070] In step S2, the control unit 50 controls the laser irradiation device 20 or the acquisition unit 60, and sets the exposure time or filter of the acquisition unit 60 and the focal position of the positioning laser LA2 so that the nozzle contour is clearly captured.

[0071] For example, performing laser cutting multiple times using the laser cutting device 100 may result in dirt adhering to the vicinity of the tip opening TO of the laser nozzle 10A or scratches being formed near the tip opening TO. In such cases, the accuracy of the nozzle contour detection by the acquisition unit 60 may decrease.

[0072] When acquiring the nozzle contour in step S2, the control unit 50 sets acquisition conditions so that the nozzle contour is clearly imaged, thereby preventing a decrease in the detection accuracy of the nozzle contour.

[0073] 5 is a photograph showing an example of the result of acquisition in the nozzle contour acquisition step S2. The result of acquisition shown in FIG. 5 is a photograph including the nozzle contour captured by the acquisition unit 60.

[0074] Here, Fig. 4 shows image data acquired by the acquisition unit 60 with the exposure time set to 1 μsec, and Fig. 5 shows image data acquired by the acquisition unit 60 with the exposure time set to 500 μsec.

[0075] That is, the results of the nozzle contour acquisition step S2 shown in FIG. 5 are image data acquired under acquisition conditions in which the exposure time is longer than the results of the laser contour acquisition step S1 shown in FIG.

[0076] In this way, when imaging the nozzle contour in the nozzle contour acquisition process S2, the acquisition unit 60 captures the image with a greater amount of light than when imaging the laser contour in the laser contour acquisition process S1, thereby improving the detection accuracy of the nozzle contour.

[0077] Methods for increasing the amount of light when acquiring the nozzle contour include adjusting the aperture of the camera that captures the nozzle contour, adjusting the optical density of the filter used when capturing the nozzle contour, and performing image processing on the captured image data (for example, adjusting brightness or the judgment threshold).

[0078] As shown in FIGS. 4 and 5, the acquisition unit 60 can appropriately acquire the laser contour and the nozzle contour by using acquisition conditions suitable for each of the laser contour acquisition step S1 and the nozzle contour acquisition step S2.

[0079] The focal position of the positioning laser LA2 when the results shown in FIGS. 4 and 5 were obtained was the same, at −18 mm.

[0080] The control unit 50 may change the focal position of the positioning laser LA2 when performing the laser contour obtaining step S1 and the nozzle contour obtaining step S2.

[0081] For example, in the nozzle contour acquisition step S2, the control unit 50 may change the position of the condenser lens 24 so that the focal position of the positioning laser LA2 is closer to the base end than the tip opening TO.

[0082] In a region distal to the focal position in the optical axis direction of the laser LA, the laser LA is irradiated with a wider beam diameter than the focal position (focal diameter). When the focal position of the laser LA is located in the internal passage OP, the laser LA is reflected by the inner circumferential surface S of the laser nozzle 10A.

[0083] By illuminating the tip opening TO with the laser LA reflected by the inner circumferential surface S of the laser nozzle 10A, the acquisition unit 60 acquires the outline of the light spread over the entire area of ​​the tip opening TO as the nozzle outline.

[0084] By reflecting the laser LA on the inner peripheral surface S of the laser nozzle 10A, the laser LA can illuminate the tip opening TO from the base end side, thereby improving the detection accuracy of the nozzle contour by the acquisition unit 60.

[0085] In step S2, the acquisition unit 60 transmits the acquired nozzle contour to the control unit 50.

[0086] The order in which steps S1 and S2 are performed is not limited to this order, and the control unit 50 may perform step S1 after performing step S2.

[0087] In addition, in step S2, the control unit 50 or the acquisition unit 60 may acquire the shading of the tip T of the laser nozzle 10A and determine whether the laser nozzle 10A can be used based on the acquired shading.

[0088] For example, the control unit 50 performs image processing on the image data of the tip T of the laser nozzle 10A captured by the acquisition unit 60 when acquiring the nozzle contour, and acquires the shading of the tip T.

[0089] The control unit 50 compares the shade of the tip T when the laser nozzle 10A is new (new shade) with the shade of the tip T obtained in step S2 (obtained shade), and determines whether the laser nozzle 10A can be used based on the difference between them.

[0090] The new product shading is stored in advance in, for example, a storage unit of the control unit 50 .

[0091] The control unit 50 acquires, for example, the presence or absence and range of uneven shapes of the tip end T based on the shading of the tip end T. The control unit 50 may use the number of uneven shapes or the range of the uneven shapes (area value, etc.) as the difference between the new shading and the acquired shading.

[0092] The control unit 50 determines that the laser nozzle 10A is unusable when the difference between the new product shading and the acquired shading is equal to or greater than a threshold value.

[0093] The control unit 50 determines that the laser nozzle 10A is usable when the difference between the new product shading and the acquired shading is less than the threshold value.

[0094] The control unit 50 may determine whether the laser nozzle 10A can be used by comparing the number and area values ​​of the uneven shapes of the tip T obtained from the obtained shade with a predetermined threshold value, without comparing the shade when new with the obtained shade.

[0095] Here, the laser cutting device 100 may be provided with a display device such as a display connected to the control unit 50 wirelessly or via a wire.

[0096] The control unit 50 outputs the determination result regarding the usability of the laser nozzle 10A to the display device. The worker can understand the usability of the laser nozzle 10A by checking the display device. For example, if the display device indicates that the laser nozzle 10A is unusable, the worker replaces the laser nozzle 10A.

[0097] The control unit 50 may determine whether the laser nozzle 10A can be used based on the nozzle contour and / or the shading of the tip T.

[0098] For example, the memory unit of the control unit 50 stores the nozzle profile when the laser nozzle 10A is brand new (new nozzle profile).

[0099] The control unit 50 compares the nozzle profile when new with the nozzle profile acquired in step S2, and determines whether the laser nozzle 10A is usable based on the difference between them.

[0100] For example, if the laser nozzle 10A has deteriorated and the tip T is scratched or the shape of the tip T is deformed, the degree of deterioration of the tip T can be determined by comparing the nozzle contour when new with the nozzle contour obtained in step S2.

[0101] (Step S3) Next, the control unit 50 performs step S3 (positional deviation amount calculation step). In step S3, the control unit 50 calculates the positional deviation amount between the optical axis of the laser LA and the laser reference position based on the laser contour and nozzle contour acquired in steps S1 and S2.

[0102] For example, if the laser reference position is the center point C of the tip opening TO, the control unit 50 calculates the distance from the center point C to the optical axis of the laser LA as the positional deviation amount between the optical axis of the laser LA and the laser reference position.

[0103] (Step S4) Next, the control unit 50 performs step S4 (positional deviation amount determination step). In step S4, the control unit 50 determines whether the positional deviation amount calculated in step S3 is outside the allowable range.

[0104] For example, when the distance from the laser reference position to the optical axis of the laser LA is used as the amount of positional deviation, the control unit 50 compares the distance from the laser reference position to the optical axis of the laser LA (amount of positional deviation) with a predetermined value (threshold value) and determines whether the amount of positional deviation is greater than or equal to the threshold value.

[0105] If the amount of misalignment is equal to or greater than the threshold, the control unit 50 determines that the amount of misalignment is outside the allowable range. If the amount of misalignment is less than the threshold, the control unit 50 determines that the amount of misalignment is within the allowable range.

[0106] If the control unit 50 determines that the amount of misalignment calculated in step S3 is within the allowable range, the process proceeds to step S6, which will be described later.

[0107] (Step S5) When the control unit 50 determines that the amount of positional deviation calculated in step S3 is outside the allowable range, it performs step S5 (position adjustment step).

[0108] In step S5, the control unit 50 controls the laser irradiation device 20 or the laser processing head 10 based on the amount of positional deviation calculated in step S3 so that the position of the optical axis of the laser LA relative to the tip opening TO is in a predetermined position.

[0109] If the positional deviation calculated in step S3 is outside the allowable range, the optical axis of the laser LA is positioned at a position far away from the laser reference position. The control unit 50 controls the laser irradiation device 20 or the laser processing head 10 so that the optical axis of the laser LA approaches the laser reference position.

[0110] For example, the control unit 50 controls the laser irradiation device 20 so that the optical axis of the laser LA approaches the laser reference position, and changes the position of the condenser lens 24 .

[0111] The control unit 50 may control the laser processing head 10 so that the optical axis of the laser LA approaches the laser reference position, and change the position of the laser nozzle 10A.

[0112] Furthermore, the control unit 50 may change the positions of the condenser lens 24 and the laser nozzle 10A so that the optical axis of the laser LA approaches the laser reference position.

[0113] Fig. 6 is a photograph showing an example of the laser profile and the nozzle profile before performing the position adjustment step S5. Fig. 7 is a photograph showing an example of the laser profile and the nozzle profile after performing the position adjustment step S5. The guide light shown in Fig. 6 and Fig. 7 represents the positioning laser LA2.

[0114] 6 is spaced 298 μm in the X-axis direction and 95 μm in the Y-axis direction from the laser reference position (center point C in this case). That is, in the horizontal direction including the X-axis and Y-axis, the distance (amount of positional deviation) from the laser reference position to the optical axis of the laser LA is approximately 313 μm.

[0115] 7 is spaced 8 μm in the X-axis direction and 4 μm in the Y-axis direction from the laser reference position (center point C in this case). That is, in the horizontal direction including the X-axis and Y-axis, the distance (amount of positional deviation) from the laser reference position to the optical axis of the laser LA is approximately 9 μm.

[0116] In this way, the control unit 50 calculates the amount of positional deviation based on the laser contour and nozzle contour acquired by the acquisition unit 60, and by changing the position of the focusing lens 24 or the laser nozzle 10A based on the calculated amount of positional deviation, the optical axis of the laser LA can be brought closer to the laser reference position.

[0117] The laser cutting device 100 may display numerical data, image data, etc., indicating the calculated amount of misalignment on the display device described above.

[0118] For example, the display device provided in the laser cutting device 100 displays image data including the laser contour and nozzle contour as exemplified in FIGS. 6 and 7 based on the data received from the control unit 50 .

[0119] By checking the image data (or numerical data, etc.) displayed on the display device, the operator can grasp the arrangement of the laser contour and nozzle contour, as well as the amount of positional deviation of the laser LA.

[0120] The display device provided in the laser cutting device 100 may receive and display the results acquired by the acquisition unit 60 in step S1 or step S2 (e.g., image data such as those illustrated in Figures 4 and 5) from the control unit 50 or the acquisition unit 60.

[0121] (Step S6) Next, the control unit 50 performs step S6 (completion determination step). In step S6, the control unit 50 determines whether or not the laser position adjustment work is to be completed.

[0122] In step S6, if the control unit 50 determines that the laser position adjustment work should not be completed, the process returns to step S1 and the subsequent steps are carried out.

[0123] For example, the control unit 50 repeats steps S1 to S6 a preset number of times. After performing step S5, the control unit 50 performs steps S1 to S4 again to check whether the alignment between the laser reference position adjusted in step S5 and the optical axis of the laser LA is set to an appropriate alignment.

[0124] When the control unit 50 returns from step S6 to step S1 to perform the subsequent steps, it may omit step S1 if the position of the laser LA has not been changed in step S5, or it may omit step S2 if the position of the laser nozzle 10A has not been changed in step S5.

[0125] Furthermore, when the control unit 50 determines in step S4 that the amount of positional deviation is within the allowable range, it may determine in step S6 to end the laser position adjustment work.

[0126] When the control unit 50 determines that the laser position adjustment work is to be ended, the control unit 50 ends the laser position adjustment work.

[0127] The laser cutting device 100 of this embodiment is a laser cutting device that laser cuts a workpiece W, and is equipped with a laser beam irradiation unit 22 that emits a laser beam LA, a laser nozzle 10A that has an internal passage OP through which the laser beam LA passes and is capable of irradiating the workpiece W with the laser beam LA from a tip opening TO provided on the tip side in the optical axis direction of the laser beam LA, an acquisition unit 60 that is capable of acquiring the outline of the laser beam LA passing through the tip opening TO and the outline of the tip opening TO, and a control unit 50 that calculates the amount of positional deviation of the optical axis of the laser beam LA relative to the tip opening TO based on the outline of the laser beam LA and the outline of the tip opening TO.

[0128] In addition, the laser position adjustment method of this embodiment includes a laser contour acquisition process S1 for acquiring the contour of the laser LA passing through the tip opening TO, a nozzle contour acquisition process S2 for acquiring the contour of the tip opening TO, and a positional deviation amount calculation process S3 for calculating the positional deviation amount of the optical axis of the laser LA relative to the tip opening TO based on the contour of the laser LA and the contour of the tip opening TO.

[0129] According to the laser cutting device 100 and laser position adjustment method of this embodiment, the worker can easily grasp the amount of positional deviation of the optical axis of the laser LA relative to the tip opening TO, compared to the conventional laser position adjustment work performed visually using a centering sheet.

[0130] As a result, it is possible to provide a laser cutting device 100 and a laser position adjustment method that can efficiently adjust the laser position.

[0131] In addition, the control unit 50 may automatically perform laser position adjustment work by changing the position of the focusing lens 24 based on the calculated positional deviation amount so that the position of the optical axis of the laser LA relative to the tip opening TO is in a predetermined position.

[0132] In addition, the control unit 50 may automatically perform laser position adjustment work by changing the position of the laser nozzle 10A based on the calculated positional deviation amount so that the position of the optical axis of the laser LA relative to the tip opening TO is in a predetermined position.

[0133] The acquisition unit 60 may also include an imaging device capable of imaging the contour of the laser LA and the contour of the tip opening TO by imaging the tip opening TO from the tip side in the optical axis direction of the laser LA.

[0134] In this case, the laser cutting device 100 does not need to place a beam splitter or the like inside the laser processing head 10, which prevents the structure of the laser processing head 10 from becoming complicated and allows for more efficient adjustment of the laser position. In addition, it is possible to prevent the maintainability of the laser cutting device 100 from decreasing due to the complicated structure of the laser processing head 10.

[0135] Furthermore, the control unit 50 may cause the acquisition unit 60 to acquire the laser contour and the nozzle contour under different acquisition conditions in the laser contour acquisition step S1 and the nozzle contour acquisition step S2.

[0136] When the acquisition unit 60 acquires the nozzle contour, by appropriately setting acquisition conditions such as exposure time, filter or the position of the focal position P of the laser LA, the acquisition unit 60 can accurately detect the nozzle contour even if there is dirt attached near the tip opening TO or if there is a scratch near the tip opening TO.

[0137] While one embodiment of the present disclosure has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present disclosure. Furthermore, the components shown in the above-described embodiment and the following modified examples can be appropriately combined to form a configuration.

[0138] (Variation 1) In each of the above embodiments, the control unit 50 controls the laser irradiation device 20 or the laser processing head 10 by performing the position adjustment step S5 so that the laser reference position and the optical axis of the laser LA are aligned in a predetermined manner, but the aspect of the control unit is not limited to this. The control unit does not have to perform the position adjustment step S5.

[0139] For example, after the control unit performs the positional deviation amount calculation process S3, an operator may position the laser reference position and the optical axis of the laser LA at predetermined positions by changing the position of the focusing lens 24 or the laser nozzle 10A based on the positional deviation amount calculated by the control unit.

[0140] At this time, the worker adjusts the position of the laser LA based on the content (image data, numerical data, etc.) displayed on a display device of the laser cutting device, for example.

[0141] Even if the control unit does not perform the position adjustment process S5, by performing the position deviation calculation process S3, which calculates the position deviation amount of the optical axis of the laser LA relative to the tip opening TO, the position deviation amount of the optical axis of the laser LA relative to the tip opening TO can be easily grasped and the position of the laser can be adjusted efficiently, compared to the conventional laser position adjustment work performed visually using a centering sheet.

[0142] (Modification 2) In each of the above-described embodiments, the optical axis of the laser LA of the laser cutting device 100 extends in the Z-axis direction, but the configuration of the laser cutting device is not limited to this.

[0143] For example, the laser cutting device may refract the laser beam emitted from the tip opening TO using a prism or the like. In this case, the acquisition unit is disposed at the position where the refracted laser beam is incident. By changing the optical path of the laser using a prism or the like, the acquisition unit can be disposed at any position, thereby saving space.

[0144] When the optical path of the laser is refracted by a prism or the like, by performing a matching operation in advance between the coordinate system of the laser and the coordinate system of the acquisition unit, the acquisition unit can accurately acquire the direction of positional deviation of the laser's optical axis from the laser reference position.

[0145] In the matching operation, for example, when the optical axis of the laser is moved in the X-axis or Y-axis direction, the results acquired by the acquisition unit (e.g., laser contour) are matched so that the direction in which the optical axis of the laser is moved matches the coordinate system in the results acquired by the acquisition unit.

[0146] (Modification 3) In each of the above-described embodiments, the control unit 50 performs the nozzle contour obtaining step S2 after the laser contour obtaining step S1, but the configuration of the control unit is not limited to this.

[0147] The order in which the control unit performs the laser contour acquisition step S1 and the nozzle contour acquisition step S2 is not limited, and the control unit may perform the laser contour acquisition step S1 after the nozzle contour acquisition step S2.

[0148] (Variant 4) In each of the above embodiments, the acquisition unit 60 acquires the laser contour and the nozzle contour, and the control unit 50 calculates the positional deviation amount of the laser LA based on the acquisition results of the acquisition unit 60, but the aspects of the acquisition unit and the control unit are not limited to this.

[0149] The amount of misalignment of the optical axis of the laser LA with respect to the tip opening TO may be calculated by the acquisition unit. For example, the acquisition unit is configured to acquire the laser contour and the nozzle contour and calculate the amount of misalignment based on the acquired results.

[0150] The acquisition unit may include an imaging unit capable of capturing images of the laser contour and the nozzle contour, and a calculation unit capable of calculating the amount of misalignment of the laser LA based on the laser contour and the nozzle contour. In this case, the acquisition unit can calculate the amount of misalignment of the laser LA by being used together with the laser cutting device.

[0151] The acquisition unit may also include a display device capable of displaying the acquired laser contour and nozzle contour, the calculated positional deviation amount, and the like.

[0152] The acquisition unit may also be configured to transmit the amount of misalignment calculated by the acquisition unit to a control unit of the laser cutting device. For example, the control unit of the laser cutting device changes the position of the condenser lens 24 or the laser nozzle 10A based on the results acquired from the acquisition unit used together with the laser cutting device so that the position of the optical axis of the laser LA with respect to the tip opening TO is in a predetermined position.

[0153] 100 Laser cutting device 10A Laser nozzle 22 Laser beam irradiation unit 24 Condenser lens 50 Control unit 60 Acquisition unit OP Internal passage TO Tip opening S Inner surface of laser nozzle W Workpiece LA Laser S1 Laser contour acquisition process S2 Nozzle contour acquisition process S3 Position deviation amount calculation process

Claims

1. A laser cutting device for laser cutting a workpiece, comprising: a laser beam irradiation unit that emits a laser; a laser nozzle that has an internal passage through which the laser passes and is capable of irradiating the workpiece with the laser from a tip opening provided on the tip side in the direction of the laser's optical axis; an acquisition unit that can acquire the outline of the laser passing through the tip opening and the outline of the tip opening; and a control unit that calculates the amount of positional deviation of the laser's optical axis with respect to the tip opening based on the outline of the laser and the outline of the tip opening.

2. A laser cutting device as described in claim 1, further comprising a focusing lens provided closer to the tip in the optical axis direction than the laser beam irradiation unit, and the control unit changes the position of the focusing lens based on the calculated amount of positional deviation so that the position of the optical axis of the laser relative to the tip opening is in a predetermined position.

3. The laser cutting device according to claim 1, wherein the control unit changes the position of the laser nozzle based on the calculated amount of positional deviation so that the position of the optical axis of the laser relative to the tip opening is in a predetermined position.

4. A laser cutting device according to any one of claims 1 to 3, wherein the acquisition unit includes an imaging device capable of imaging the contour of the laser and the contour of the tip opening by imaging the tip opening from the tip side.

5. The laser cutting device according to claim 4, wherein the acquisition unit captures an image of the contour of the tip opening so that the amount of light is greater than when capturing an image of the contour of the laser.

6. The laser cutting device according to claim 4, wherein the control unit reflects the laser on an inner peripheral surface of the laser nozzle when the acquisition unit captures an image of the contour of the tip opening.

7. The laser cutting device according to claim 1, wherein the acquisition unit includes an imaging device capable of capturing an image of the tip of the laser nozzle, and the control unit acquires the shading of the tip of the laser nozzle captured by the acquisition unit, and determines whether the laser nozzle can be used based on the outline of the tip opening and / or the shading of the tip.

8. A laser position adjustment method for a laser cutting device comprising a laser beam irradiation unit that emits a laser, and a laser nozzle that has an internal passage through which the laser passes and is capable of irradiating the laser onto a workpiece from a tip opening provided on the tip side in the optical axis direction of the laser, the method comprising: a laser contour acquisition step that acquires the contour of the laser passing through the tip opening; a nozzle contour acquisition step that acquires the contour of the tip opening; and a position deviation amount calculation step that calculates the amount of position deviation of the optical axis of the laser with respect to the tip opening based on the contour of the laser and the contour of the tip opening.

9. The laser position adjustment method according to claim 8, further comprising changing the position of a condenser lens through which the laser passes so that the position of the optical axis of the laser relative to the tip opening is in a predetermined position based on the amount of positional deviation.

10. The laser position adjustment method according to claim 8, further comprising changing the position of the laser nozzle based on the amount of positional deviation so that the position of the optical axis of the laser relative to the tip opening is in a predetermined position.

Images