Galvanic scanner and laser processing machine

Abstract

A galvanometer scanner (32) according to the present invention has a motor (35) and an electrolytic corrosion suppression unit (37). The motor (35) has a rotor (340) having a permanent magnet (341) that rotates about a rotation axis and shafts (342, 343) connected to both sides of the permanent magnet (341) along the rotation axis, and a stator (330) disposed at a predetermined distance from the rotor (340). The electric corrosion suppression unit (37) is provided at one end of the two ends of the motor (35) in the direction of the rotation axis, said end being not provided with the electrically controlled mirror (31), and electrically connects the stator (330) and the rotor (340).

Description

Technical Field

[0001] The present invention relates to an electric scanner and a laser processing machine for rotationally driving an electric-controlled mirror, wherein the electric-controlled mirror irradiates a laser beam from a laser light source to a desired position on a processing object. Background Art

[0002] In a laser processing machine, the irradiation position of the laser beam on the workpiece, i.e., the processing position, is controlled by an electric scanner. The electric scanner is a servo motor that rotates an electrically controlled mirror mounted on one end of a shaft. The electric scanner has a bearing that supports the shaft. In one example, the bearing is a rolling bearing, which has: a cylindrical inner ring that holds the shaft; a cylindrical outer ring that is concentrically arranged on the outer side of the inner ring; and a rotating body that is arranged between the inner ring and the outer ring. In the bearing, an oil film exists between the inner ring and the outer ring and the rotating body.

[0003] Due to the influence of the eddy current of the magnet when the electric scanner is driven, a potential difference, i.e., shaft voltage, is sometimes generated between the inner and outer rings of the bearing. During the operation of the laser processing machine, if the inner and outer rings are insulated by the oil film of the bearing and the oil film breaks at a certain moment and the inner and outer rings are connected, discharge sometimes occurs between the inner and outer rings, and the bearing is damaged. The damage to the bearing as described above is called electrical corrosion. If electrical corrosion occurs, the inside of the bearing will be damaged, which sometimes hinders the smooth rotation of the bearing and has an adverse effect on the control of the irradiation position of the laser beam.

[0004] Patent document 1 discloses a structure for preventing electrolytic corrosion of the bearing of the rotor shaft of an electric generator for driving a vehicle. In the technology described in patent document 1, an oil chamber is provided at one axial end of the rotor shaft in the housing of the electric generator. When the electric generator is in a high rotation state, an axial force, i.e., a thrust, is applied to the rotor shaft by applying oil pressure to the oil chamber in the housing, so that the rotating body of the bearing and the inner and outer rings are actively in contact. As a result, the oil film between the rotating body of the bearing and the inner and outer rings is broken, the conduction is strengthened, and the above-mentioned electrolytic corrosion is suppressed.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-014359 Summary of the invention

[0006] The technology described in Patent Document 1 is aimed at suppressing electrolytic corrosion in electric generators used to drive vehicles such as automobiles. Therefore, by applying thrust to the rotor shaft through oil pressure, even if the rotating body of the bearing contacts the inner ring and the outer ring, no particular problem will occur. However, the technology described in Patent Document 1 cannot be applied to products that require high positioning accuracy during operation, such as the electric scanner of a laser processing machine. Specifically, in the technology described in Patent Document 1, the preload of the bearing will change by applying or not applying oil pressure, and the rigidity of the bearing in the radial direction will change, which may have a great impact on the accuracy of the product, specifically, the accuracy of the irradiation position of the laser beam. That is, there is a problem that it is difficult to apply the technology described in Patent Document 1, which has a great impact on the control of position accuracy, to the electric scanner that drives the electrically controlled reflector in the laser processing machine that requires precise position control of the laser beam.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a galvano-scanner capable of suppressing galvanic erosion while suppressing axial displacement between an inner ring and an outer ring as compared with the related art.

[0008] In order to solve the above problems and achieve the purpose, the galvanic scanner of the present invention comprises a motor and an galvanic erosion suppression unit. The motor comprises a rotor and a stator, wherein the rotor comprises a permanent magnet that rotates around a rotation axis and a shaft connected to both sides of the permanent magnet along the rotation axis, and the stator is arranged at a predetermined distance from the rotor. The galvanic erosion suppression unit is provided at the end of the motor that is not provided with an electric-controlled reflector, of the two ends of the motor in the direction of the rotation axis, to electrically connect the stator and the rotor.

[0009] Effects of the Invention

[0010] The galvano-scanner according to the present invention has an effect of being able to suppress galvanic corrosion while suppressing axial displacement between the inner ring and the outer ring as compared with the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a diagram showing an example of the structure of the laser processing machine involved in the first embodiment.

[0012] Figure 2 This is a diagram schematically showing an example of the configuration of the galvano-scanner according to the first embodiment.

[0013] Figure 3 This is a cross-sectional view showing an example of the structure of a ground structure used in the galvano-scanner according to the first embodiment.

[0014] Figure 4 This is a diagram schematically showing another example of the configuration of the galvano-scanner according to the first embodiment.

[0015] Figure 5 This is a diagram schematically showing another example of the configuration of the galvano-scanner according to the first embodiment. DETAILED DESCRIPTION

[0016] Hereinafter, a galvano-scanner and a laser processing machine according to embodiments of the present invention will be described in detail with reference to the drawings.

[0017] Implementation method 1.

[0018] Figure 1 1 is a diagram showing an example of the structure of a laser processing machine according to Embodiment 1. The laser processing machine 1 performs hole drilling of a workpiece W as a processing target by irradiating a pulsed laser beam L. An example of the workpiece W is a printed circuit board or an IC (Integrated Circuit) package board mounted in electronic equipment or the like. The workpiece W may be any object that can be subjected to hole drilling, and may be an object other than the printed circuit board or IC package board.

[0019] exist Figure 1 In the laser processing machine 1, the X-axis, the Y-axis, and the Z-axis are three axes perpendicular to each other. The X-axis and the Y-axis are axes in the horizontal direction. The Z-axis is an axis in the vertical direction. The laser processing machine 1 performs a hole drilling process to form a plurality of holes dispersed in the X-axis direction and the Y-axis direction at a high speed.

[0020] The laser processing machine 1 comprises: a laser oscillator 10 that emits a laser beam L; a laser optical element 20 that shapes the shape of the laser beam L and adjusts the output; a processing head 30 that irradiates the laser beam L to a desired position; and a workpiece conveying table 40 that holds a workpiece W to be processed.

[0021] The laser oscillator 10 outputs a pulsed laser beam L. The pulsed laser beam L is infrared light in one example. An example of the laser oscillator 10 is a carbon dioxide (CO2) laser. The peak wavelength of the pulsed laser beam L is included in the range of 9.3 μm to 10.6 μm. Hereinafter, the pulsed laser beam L is referred to as the laser beam L.

[0022] The laser optical element 20 shapes the outer shape of the laser beam L output from the laser oscillator 10 and outputs it to the processing head 30. The laser optical element 20 includes: a collimator lens 21 that adjusts the convergence of the laser beam L output from the laser oscillator 10 to collimate the laser beam L; and a mask hole 22 that cuts the laser beam L in a shape to be transferred to the workpiece W to be processed. One or more collimator lenses 21 are arranged. The shape of the mask hole 22 is usually circular.

[0023] The machining head 30 includes: galvano mirrors 31Y and 31X that deflect the laser beam L; galvano scanners 32Y and 32X that rotationally drive the galvano mirrors 31Y and 31X; and an fθ lens 33 that focuses the laser beam L.

[0024] The galvano-mirror 31Y reflects the laser beam L incident on the processing head 30. The galvano-scanner 32Y is a servo motor used to position the galvano-mirror 31Y. The galvano-scanner 32Y rotates the galvano-mirror 31Y by control according to the position instruction. That is, the galvano-scanner 32Y adjusts the position and angle of the laser beam L incident on the fθ lens 33. Specifically, the galvano-scanner 32Y rotates the galvano-mirror 31Y within a specific swing angle range, thereby moving the irradiation position of the laser beam L in the Y-axis direction.

[0025] The galvano-mirror 31X reflects the laser beam L incident from the galvano-mirror 31Y. The galvano-scanner 32X is a servo motor used to position the galvano-mirror 31X. The galvano-scanner 32X rotates the galvano-mirror 31X by control according to the position instruction. That is, the galvano-scanner 32X adjusts the position and angle of the laser beam L incident on the fθ lens 33. Specifically, the galvano-scanner 32X rotates the galvano-mirror 31X within a specific swing angle range, thereby moving the irradiation position of the laser beam L in the X-axis direction.

[0026] The fθ lens 33 is a lens that focuses the laser beam L reflected by the galvano-mirror 31X and irradiates the laser beam L vertically onto the workpiece W to be processed.

[0027] The workpiece conveying table 40 moves in the X-axis direction or the Y-axis direction by control according to the position instruction. That is, the workpiece conveying table 40 has a driving mechanism in the X-axis direction and a driving mechanism in the Y-axis direction. The driving mechanism in the X-axis direction and the driving mechanism in the Y-axis direction are driven according to the position instruction, so that the workpiece conveying table 40 can change its position in the XY plane. The movable range of the electric-controlled mirrors 31Y and 31X formed by the drive of the electric scanners 32Y and 32X, that is, the change of the irradiation position of the laser beam L in the X-axis direction and the Y-axis direction realized by the electric-controlled mirrors 31Y and 31X is limited to an extremely narrow range. Therefore, for the change of only the irradiation position of the electric-controlled mirrors 31Y and 31X realized by the drive of the electric scanners 32Y and 32X, it is difficult to perform hole drilling on the entire workpiece W to be processed. Therefore, after the processing in the movable range of the galvano-controlled mirrors 31Y and 31X formed by the driving of the galvano-controlled mirrors 31Y and 31X is completed, the position of the workpiece W to be processed is changed using the workpiece conveying table 40, and the processing is performed again in the movable range of the galvano-controlled mirrors 31Y and 31X formed by the driving of the galvano-controlled mirrors 32Y and 32X. In this way, the entire workpiece W to be processed can be processed by drilling.

[0028] The laser processing machine 1 further includes a control device 50 for controlling the entire laser processing machine 1. The control device 50 controls the operation of the laser oscillator 10, the galvano scanners 32Y and 32X, the workpiece conveying table 40, and the like. In one example, the control device 50 generates a position command for the workpiece conveying table 40, a laser output command for the laser oscillator 10, and a position command for the galvano scanners 32Y and 32X. The position command for the workpiece conveying table 40 is output to the drive mechanism in the X-axis direction and the drive mechanism in the Y-axis direction of the workpiece conveying table 40. The laser output command is output to the laser oscillator 10. The position command for the galvano scanners 32Y and 32X is output to the galvano scanners 32Y and 32X. In addition, hereinafter, the galvano scanners 32Y and 32X are referred to as the galvano scanner 32 when not being distinguished separately. In addition, the galvano mirrors 31Y and 31X are referred to as the galvano mirrors 31 when not being distinguished separately.

[0029] Next, the structure of the galvano-scanner 32 will be described. Figure 2 FIG. 1 is a diagram schematically showing an example of the structure of the galvano-scanner according to Embodiment 1. Figure 2, the galvano-mirror 31 fixed to the galvano-scanner 32 is also shown. The galvano-scanner 32 includes a motor 35 and an electro-corrosion suppressing unit 37 for suppressing the occurrence of electro-corrosion in bearings 351 and 352 of the motor 35. In addition, of the two ends of the motor 35 in the direction of the rotation axis of the rotor 340 described later, the end where the galvano-mirror 31 is provided is referred to as the first end, and the end where the electro-corrosion suppressing unit 37 is provided is referred to as the second end.

[0030] The electrically controlled mirror 31 is fixed to the shaft 342 of the rotor 340 described later of the motor 35 on the first end side of one of the two ends of the motor 35 in the direction of the rotation axis, and rotates around the rotation axis. The electrically controlled mirror 31 has a mirror 311 and a mirror holder 312. The mirror 311 is fixed to the mirror holder 312. The mirror holder 312 is fixed to the shaft 342 of the motor 35 to hold the mirror 311. The mirror 311 reflects the incident laser beam L. The electrically controlled mirror 31 rotates in conjunction with the shaft 342, thereby deflecting the laser beam L to an arbitrary angle. Generally speaking, it is sufficient if the rotation angle of the electrically controlled mirror 31 is about ±20 degrees.

[0031] The motor 35 has a stator 330, a rotor 340 and a pair of bearings 351, 352. The stator 330 is made of a conductive material. The stator 330 has a frame 331, an iron core 332, a coil 333 and a conductor 334. The frame 331 accommodates the iron core 332, the coil 333, the rotor 340 and a pair of bearings 351, 352. The frame 331 has a hollow structure capable of accommodating the rotor 340 inside. The frame 331 is made of a conductive material. The iron core 332 is a cylindrical component for generating torque of the motor 35. The iron core 332 is preferably a ferromagnetic material such as iron. The coil 333 is arranged along the inner circumferential surface of the iron core 332 and is cylindrical. The cylindrical coil 333 is arranged inside the cylindrical iron core 332. The conductive wire 334 is a wiring that electrically connects a current amplifier (not shown) and the coil 333, and allows a current from the current amplifier to flow through the coil 333. When a current flows through the conductive wire 334, the rotor 340 rotates, and the motor 35 can be driven.

[0032] The rotor 340 is made of a conductive material. The rotor 340 has a permanent magnet 341 and shafts 342 and 343. The permanent magnet 341 is arranged on the inner side of the cylindrical coil 333 at a predetermined distance from the coil 333. In one example, the permanent magnet 341 has a cylindrical shape, and different magnetic poles are arranged alternately in the circumferential direction. The permanent magnet 341 can rotate around the central axis of the cylindrical coil 333. The central axis of the cylindrical coil 333 corresponds to the rotation axis. The shafts 342 and 343 are connected to both sides of the permanent magnet 341 along the rotation axis. The permanent magnet 341 and the shafts 342 and 343 can be formed integrally or connected by welding or other methods. The electrically controlled reflector 31 is fixed at the end of one shaft 342. The other shaft 343 protrudes compared to the end of the frame 331 of the stator 330. The shafts 342 and 343 rotate as the permanent magnet 341 rotates, and thereby the galvano-mirror 31 also rotates around the rotation axis.

[0033] A pair of bearings 351 and 352 rotatably hold shafts 342 and 343, respectively, inside the frame 331. In one example, the bearings 351 and 352 are rolling bearings, which have: an outer ring fixed to the frame 331; an inner ring that holds the shafts 342 and 343; and a rotating body held between the inner ring and the outer ring. An oil film is stretched between the inner ring and the outer ring and the rotating body. By the rotation of the permanent magnet 341 of the rotor 340, the inner ring that holds the shafts 342 and 343 fixed to the permanent magnet 341 rotates relative to the outer ring fixed to the frame 331 with the rotation axis as the center. At this time, the rotating body also rotates.

[0034] The electro-corrosion suppression unit 37 is provided at the second end side of the two ends of the motor 35 in the direction of the rotation axis, on the side where the galvano-mirror 31 is not provided, and electrically connects the stator 330 and the rotor 340. Specifically, the electro-corrosion suppression unit 37 is provided at the end of the stator 330 on the opposite side of the galvano-mirror 31. The electro-corrosion suppression unit 37 is a component that electrically connects the stator 330 and the rotor 340, that is, it is a component that sets the stator 330 and the rotor 340 to the same potential. The electro-corrosion suppression unit 37 includes: a support structure 370 that is electrically connected to the stator 330; and a grounding structure 380 that electrically connects the stator 330 and the support structure 370 to the rotor 340.

[0035] The support structure 370 supports the grounding structure 380 at the second end of the stator 330. Specifically, the support structure 370 is provided at the second end of the stator 330 on the opposite side of the first end where the electric-controlled reflector 31 is provided. The support structure 370 includes a plate-like component 371 and a leg 372. The plate-like component 371 is a plate-like component arranged in a manner perpendicular to the rotation axis, and corresponds to the first component. A through hole 371a for supporting the grounding structure 380 is provided at a position of the plate-like component 371 intersecting with the virtual straight line, i.e., the rotation axis. A thread is cut on the inner circumferential surface of the through hole 371a to form an internal thread. The leg 372 is a component that supports the plate-like component 371 at the end of the stator 330. The leg 372 may be a cylindrical component or a rod-like component extending in the direction of the rotation axis. In the latter case, the plate-like member 371 may be supported at the end of the stator 330 by two or more rod-like members. In one example, the leg 372 is fixed to the frame 331 of the stator 330 by a fixing method such as screws or welding. In addition, the leg 372 is fixed to the plate-like member 371 by a fixing method such as screws or welding. In one example, the plate-like member 371 and the leg 372 are made of a conductive material such as stainless steel.

[0036] The grounding structure 380 is a member made of a conductive material and is in contact with the rotor 340 at one end and supported by the supporting structure 370 at the other end. Figure 2 In the example, one end of the grounding structure 380 is arranged in the through hole 371a provided in the plate-shaped part 371 of the support structure 370. Specifically, the grounding structure 380 is arranged so that one end is fixed to the through hole 371a of the plate-shaped part 371, and the other end is in contact with the shaft 343 of the rotor 340. A thread is cut on the outer peripheral surface of the grounding structure 380 to form an external thread. By screwing the grounding structure 380 with the through hole 371a, the grounding structure 380 can be fixed to the support structure 370. The grounding structure 380 preferably has a structure that maintains electrical connection with the shaft 343 even if the shaft 343 rotates. In one example, the grounding structure 380 can be a needle-shaped part or a ball plunger. In one example, the grounding structure 380 is made of stainless steel.

[0037] Figure 3 FIG. 1 is a cross-sectional view showing an example of the structure of a ground structure used in the galvano-scanner according to Embodiment 1. Figure 3, the grounding structure 380 is a ball plunger. The grounding structure 380 includes: a spherical member 381, which is made of a conductive material; an elastic member 382, ​​which is arranged in contact with the spherical member 381 and is made of a conductive material; and a frame 383, which accommodates the spherical member 381 and the elastic member 382 and is made of a conductive material. Inside the frame 383, one end of the elastic member 382 is fixed inside the frame 383, and the other end is in contact with the spherical member 381. The spherical member 381 is not fixed to the elastic member 382, ​​but is only in contact. In addition, the spherical member 381 abuts against the shaft 343 of the rotor 340. As a result, the spherical member 381 rotates in conjunction with the rotation angle of the rotor 340. That is, if the shaft 343 of the rotor 340 abutting against the spherical member 381 rotates, the spherical member 381 also rotates. As a result, the rotor 340 can rotate smoothly. The spherical member 381 corresponds to the second member.

[0038] In addition, the spherical member 381 is movable so as to always contact the rotor 340. Thus, the pressing force of the spherical member 381 to press the rotor 340 in the direction of the rotation axis can be adjusted. In one example, the spherical member 381 can be pressed toward the rotor 340 under the condition that the position accuracy of the laser beam L reflected by the galvano-controlled mirror 31 generated by pressing the rotor 340 in the direction of the rotation axis does not deteriorate. In addition, the galvano-scanner 32 can be used in a state where the contact reliability between the spherical member 381 and the rotor 340 is ensured.

[0039] Furthermore, during the rotation of the spherical member 381, the spherical member 381 is in contact with the elastic member 382, ​​and thus can move in the direction of the rotation axis in a manner of abutting against the rotor 340. That is, the elastic member 382 is in contact with the spherical member 381, and pushes the spherical member 381 toward the rotor 340. Thus, the spherical member 381 can always be in contact with the rotor 340 through the elastic member 382. Furthermore, electrical contact can be ensured between the spherical member 381 and the elastic member 382, ​​and electrical contact can be ensured between the rotor 340 and the stator 330 via the grounding structure 380 and the support structure 370.

[0040] As described above, the elastic member 382 pushes the spherical member 381 with a force that maintains contact between the spherical member 381 and the rotor 340. The force generated by the displacement of the elastic member 382, ​​that is, the pushing force, presses the rotor 340 of the motor 35 in the direction of the rotation axis, and is adjusted so that the rotor 340 does not displace in the direction of the rotation axis relative to the stator 330. In one example, the elastic member 382 is a spring.

[0041] The operation of the galvano-scanner 32 as described above will be described. When a current flows through the coil 333 according to the instruction from the control device 50, the rotor 340 rotates. The galvano-mirror 31 fixed to the shaft 342 also rotates due to the rotation of the rotor 340. The grounding structure 380 is in contact with the other shaft 343 at the second end of the motor 35 on the opposite side to the first end where the galvano-mirror 31 is provided. That is, the rotor 340 and the stator 330 are in a state of being electrically connected via the grounding structure 380 and the support structure 370, and the rotor 340 and the stator 330 are at the same potential. Therefore, the influence of the eddy current of the magnet when the galvano-scanner 32 is driven is suppressed, and the potential difference, that is, the shaft voltage, is generated between the inner ring and the outer ring of the bearings 351 and 352. In addition, even if the inner ring and the outer ring are insulated by the oil film of the bearings 351 and 352, and then the oil film is broken and the inner ring and the outer ring are in contact, the inner ring and the outer ring are at the same potential via the electrolytic corrosion suppression unit 37, thereby suppressing the occurrence of discharge between the inner ring and the outer ring. As a result, damage to the inside of the bearings 351 and 352 is suppressed. By suppressing damage to the inside of the bearings 351 and 352, the bearings 351 and 352 can continue to rotate smoothly without causing adverse effects on the control of the irradiation position of the laser beam L.

[0042] In addition, if the electrical contact between the rotor 340 and the stator 330 is maintained by the electrical erosion suppression portion 37, it is not limited to Figure 2 The structure shown. Figure 2 In the embodiment, the area of ​​the plate-shaped member 371 of the electro-corrosion suppression unit 37 in the direction perpendicular to the rotation axis is substantially the same as the area of ​​the stator 330 in the direction perpendicular to the rotation axis. However, if the grounding structure 380 is connected to the shaft 343 and the plate-shaped member 371 is capable of supporting the grounding structure 380, the size and shape of the area of ​​the plate-shaped member 371 in the direction perpendicular to the rotation axis are not particularly limited.

[0043] In order to stabilize the pressing force generated by the elastic member 382 of the grounding structure 380, it is necessary to reliably determine the position of the frame 383 of the grounding structure 380 in the direction of the rotation axis. Figure 2 As shown, when the grounding structure 380 is fixed to the plate-shaped member 371, if a long-term product is used, the grounding structure 380, which is an external thread, may move in the direction of the rotation axis. As described above, if the position of the frame 383 in the direction of the rotation axis changes, the fixed position of the elastic member 382 also changes, and the magnitude of the pushing force also changes. That is, the pushing force generated by the elastic member 382 becomes unstable. Therefore, the position of the elastic member 382 can be fixed so that the spherical member 381 can always contact the rotor 340 with a constant pushing force.

[0044] Figure 4 2 is a diagram schematically showing another example of the structure of the galvano-scanner according to Embodiment 1. The same reference numerals are given to the same components as those described above, and their description is omitted. Figure 4 In FIG. 3 , the length of the ground structure portion 380 a is longer than the thickness of the plate-shaped member 371 . Figure 2 , the end of the grounding structure 380 on the opposite side to the motor 35 is shown to be inside the through hole 371a of the plate-shaped member 371, but in Figure 4 In the embodiment, the ground structure 380a penetrates the through hole 371a of the plate-shaped member 371. Figure 4 The electro-corrosion suppression part 37 also includes a nut 385, which is a positioning part that suppresses the movement of the grounding structure 380a in the direction of the rotation axis and determines the fixed position of the elastic member 382. Although not shown in the figure, as described above, a thread is cut on the outer peripheral surface of the grounding structure 380a, so the nut 385 is screwed into the portion protruding from the plate-like member 371. As a result, the movement of the grounding structure 380a in the direction of the rotation axis is suppressed, and the fixed position of the elastic member 382 is stabilized. As a result, the spherical member 381 can always be in contact with the rotor 340 with a constant pushing force.

[0045] Figure 5 This is a diagram schematically showing another example of the configuration of the galvano-scanner according to Embodiment 1. The same components as those described above are denoted by the same reference numerals, and description thereof will be omitted. Figure 5 The electro-corrosion suppression unit 37 is Figure 2 In addition to the structure shown in the figure, there is also a grounding structure fixing part 390. The grounding structure fixing part 390 is a component provided on the side of the support structure 370 opposite to the motor 35, and is fixed so that the position of the grounding structure 380 in the direction of the rotation axis does not move. The grounding structure fixing part 390 corresponds to the positioning component. The grounding structure fixing part 390 includes a support structure 391 and a position fixing part 395.

[0046] The support structure 391 has a plate-like component 392 and a foot 393. The plate-like component 392 is a plate-like component arranged in a manner perpendicular to the rotation axis. A through hole 392a for supporting the position fixing part 395 is provided at the position of the plate-like component 392 intersecting with the virtual straight line, i.e., the rotation axis. The through hole 392a is a screw hole, and a thread is cut on the inner circumference of the through hole 392a to form an internal thread. The foot 393 is a component that supports the plate-like component 392 through the plate-like component 371 of the support structure 370. The foot 393 can be a cylindrical component or a rod-like component extending in the direction of the rotation axis. In the latter case, the plate-like component 392 can be supported on the plate-like component 371 of the support structure 370 by two or more rod-like components. In one example, the foot 393 is fixed to the plate-like component 371 of the support structure 370 by a fixing method such as threading or welding. In addition, the leg portion 393 is fixed to the plate-shaped member 392 by a fixing method such as screws or welding.

[0047] The position fixing portion 395 is a member that contacts the end of the grounding structure 380 at one end and is supported by the supporting structure 391 at the other end. In one example, the position fixing portion 395 is a member that extends in the direction of the rotation axis. Figure 5 In the example, the position fixing portion 395 is configured so that one end is fixed to the through hole 392a of the plate-shaped member 392, and the other end is in contact with the grounding structure 380. A thread is cut on the outer peripheral surface of the position fixing portion 395 to form an external thread. By screwing the position fixing portion 395 with the through hole 392a, the position fixing portion 395 can be fixed to the supporting structure 391. Thus, the grounding structure 380 is pressed in by the position fixing portion 395 from the opposite side to the motor 35. That is, the position of the grounding structure 380 in the direction of the rotation axis, more specifically, the fixed position of the elastic member 382 is fixed. As a result, the spherical member 381 can always be in contact with the rotor 340 with a constant pushing force.

[0048] As described above, the galvano-scanner 32 of the first embodiment includes: a motor 35 including a rotor 340, a stator 330, and bearings 351 and 352, wherein the rotor 340 includes a permanent magnet 341 that rotates around a rotation axis and shafts 342 and 343 connected to both sides of the permanent magnet 341 along the rotation axis, the stator 330 is arranged at a predetermined distance from the rotor 340, and the bearings 351 and 352 support the shafts 342 and 343; and an galvano-corrosion suppressing unit 37 that is provided at the end of the motor 35 in the direction of the rotation axis where the galvano-mirror 31 is not provided, and electrically connects the stator 330 and the rotor 340. Thus, when the galvano-scanner 32 is operated, the galvano-corrosion suppressing unit 37 electrically connects the stator 330 and the rotor 340, so that the inner and outer races of the bearings 351 and 352 are at the same potential. In addition, the electrolytic corrosion suppression portion 37 contacts the rotor 340 with a pressing force to the extent that the contact with the shaft 343 of the rotor 340 is maintained. Therefore, compared with the conventional method, it is possible to suppress the displacement of the inner ring and the outer ring of the bearings 351 and 352 in the direction of the rotating axis while suppressing the occurrence of electrolytic corrosion between the inner ring and the outer ring of the bearings 351 and 352.

[0049] In addition, in the prior art, until the oil film surrounding the rotating bodies of the bearings 351 and 352 is broken and the inner ring, the rotating body and the outer ring are connected, the thrust is applied to the rotor shaft by oil pressure, and if the connection is not necessary, the thrust is removed. That is, two types of control are performed, namely, turning on the thrust and turning off the thrust. If the prior art described above is applied to the electric scanner 32 that requires strict positioning accuracy, when it is turned on, the rotor 340 is displaced in the direction of the rotation axis, and thus the electric control mirror 31 is also displaced in the direction of the rotation axis. If the displacement described above occurs, the position accuracy of the laser beam L reflected by the electric control mirror 31 is deteriorated. When switching from on to off, the rotor 340 is also displaced in the direction of the rotation axis, and the position accuracy is also deteriorated. On the other hand, in the galvano scanner 32 of the first embodiment, the grounding structure 380 of the erosion suppression unit 37 only needs to achieve electrical conduction between the rotor 340 and the stator 330, so it is not necessary to press with such a strong force as described above, and it is only necessary to suppress it to the extent that the grounding structure 380 and the rotor 340 are always in contact. Therefore, compared with the thrust force of the prior art, the thrust force in the direction of the rotating axis of the first embodiment is weak, and there is no adverse effect on the position accuracy of the laser beam L reflected by the galvano mirror 31. In addition, in the first embodiment, the inner ring, the rotating body, and the outer ring of the bearings 351 and 352 are not actively made conductive, and the rotating body is used in a state where the rotating body is wrapped in an oil film, so as described above, the occurrence of erosion between the inner ring and the outer ring of the bearings 351 and 352 can be suppressed.

[0050] And, if Figure 4 and Figure 5 As shown, the electric corrosion suppression unit 37 further includes a positioning member that fixes the elastic member 382 of the ground structure 380 at a position other than the position where the elastic member 382 contacts the spherical member 381. Thus, the position of the elastic member 382 is fixed, and the pressing force can be stabilized.

[0051] The configuration described in the above embodiment is merely an example, and may be combined with other known technologies, the embodiments may be combined with each other, and part of the configuration may be omitted or changed without departing from the gist.

[0052] Description of the label

[0053] 1 laser processing machine, 10 laser oscillator, 20 laser optical element, 21 collimating lens, 22 mask hole, 30 processing head, 31, 31X, 31Y electrically controlled mirrors, 32, 32X, 32Y electric scanners, 33 fθ lens, 35 motor, 37 electro-corrosion suppression unit, 40 workpiece conveyor, 50 control device, 311 mirror, 312 mirror holder, 330 stator, 331 frame, 332 core, 333 coil, 334 wire, 340 rotor, 341 permanent magnet, 342, 343 shafts, 351, 352 bearings, 370, 391 supporting structure, 371, 392 plate-like parts, 371a, 392a through holes, 372, 393 feet, 380, 380a grounding structure, 381 spherical part, 382 elastic part, 383 frame, 385 nut, 390 grounding structure fixing part, 395 position fixing part, L laser beam, W workpiece to be processed.

Claims

1. An electric scanner, characterized in that have: An electric motor having a rotor and a stator, wherein the rotor has a permanent magnet that rotates around a rotation axis and a shaft connected to both sides of the permanent magnet along the rotation axis, and the stator is arranged at a predetermined distance from the rotor; as well as The galvanic corrosion suppressing unit is provided at one end portion of the two ends of the electric motor in the direction of the rotation axis, the end portion on which the galvano-mirror is not provided, and electrically connects the stator and the rotor.

2. The galvano-scanner according to claim 1, characterized in that: The electrical corrosion suppression unit has: a grounding structure that abuts against the rotor; and a supporting structure that supports the grounding structure through an end portion of the stator, The ground structure and the support structure are made of a conductive material.

3. The galvano-scanner according to claim 2, characterized in that: The supporting structure has a first component, and the first component is provided with a through hole on an extension line of the rotating shaft. The ground structure is disposed in the through hole.

4. The galvano-scanner according to claim 3, characterized in that: The grounding structure has a second member that comes into contact with the rotor.

5. The galvano-scanner according to claim 4, characterized in that: The second member is movable in the direction of the rotation axis so as to come into contact with the rotor.

6. The galvano-scanner according to claim 5, characterized in that: The grounding structure further includes an elastic member that contacts the second member and presses the second member toward the rotor.

7. The galvano-scanner according to claim 6, characterized in that: The grounding structure is fixed to the supporting structure.

8. The galvano-scanner according to claim 7, characterized in that: The electrical corrosion suppression portion further includes a positioning member that fixes the elastic member at a position other than a position in contact with the second member.

9. A laser processing machine, characterized in that: have: a laser oscillator that emits a laser beam; a lens for focusing the laser beam and irradiating the laser beam to a processing object; The galvano-scanner according to any one of claims 1 to 8, wherein the position and angle at which the laser beam is incident on the lens are adjusted; as well as A galvano-controlled mirror is fixed to the shaft at an end portion where the galvanic corrosion suppressing portion is not provided, among two ends of the motor in the direction of the rotation axis of the galvano-scanner, and rotates around the rotation axis.

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