JP7241994B1 - Galvanometer scanner and laser processing machine - Google Patents

Abstract

A galvanometer scanner (32) according to the present disclosure includes a motor (35) and an electrolytic corrosion suppressor (37). The motor (35) includes a rotor (340) having a permanent magnet (341) rotating about an axis of rotation and shafts (342, 343) connected to either side of the permanent magnet (341) along the axis of rotation, and a rotor It has a stator (330) positioned at a defined distance from (340). The electrolytic corrosion suppressing part (37) is provided at one of the two ends of the motor (35) in the direction of the rotation axis where the galvanomirror (31) is not provided. (340) are electrically connected.

Description

The present disclosure relates to a galvanometer scanner and a laser processing machine that rotationally drive a galvanometer mirror that irradiates a desired position on an object to be processed with a laser beam from a laser light source.

In a laser processing machine, a laser beam irradiation position on a workpiece, that is, a processing position is controlled by a galvanometer scanner. A galvo scanner is a servomotor that rotates a galvo mirror mounted on one end of a shaft. A galvo scanner has a bearing that supports a shaft. In one example, the bearing has a cylindrical inner ring that holds the shaft, a cylindrical outer ring arranged outside the inner ring concentrically with the inner ring, and rolling elements arranged between the inner ring and the outer ring. It is a rolling bearing. In bearings, an oil film exists between the inner and outer rings and the rolling elements.

Axial voltage, which is a potential difference, may be generated between the inner ring and the outer ring of the bearing due to the influence of eddy current of the magnet when the galvanometer scanner is driven. During the operation of the laser processing machine, if the inner and outer rings are insulated by the oil film of the bearing at a certain moment, the oil film breaks and the inner and outer rings are electrically connected. Discharge may occur and damage the bearing. Such bearing damage is called galvanic corrosion. If electrolytic corrosion occurs, the inside of the bearing is damaged, which hinders smooth rotation of the bearing and may adversely affect the control of the irradiation position of the laser beam.

Japanese Patent Application Laid-Open No. 2002-201001 discloses a structure for preventing electrolytic corrosion of a bearing of a rotor shaft of a motor generator for driving a vehicle. In the technique described in Patent Document 1, an oil chamber is provided at one end in the axial direction of the rotor shaft in the housing of the motor generator. By applying hydraulic pressure to the oil chamber in the housing when the motor generator is in a high rotation state, thrust force, which is an axial force, is applied to the rotor shaft, and the rolling elements of the bearing and the inner and outer rings are actively engaged. contact. As a result, the oil film is broken between the rolling elements of the bearing and the inner and outer rings, thereby enhancing electrical continuity and suppressing the above-described electrolytic corrosion.

JP 2020-014359 A

The technique described in Patent Literature 1 is aimed at suppressing electrolytic corrosion in a motor generator for driving a vehicle such as an automobile. Therefore, even if a thrust force is applied to the rotor shaft by hydraulic pressure to bring the rolling elements of the bearing into contact with the inner ring and the outer ring, there is no particular problem. However, the technology described in Patent Literature 1 cannot be applied to products that require high positioning accuracy during operation, such as galvanometer scanners for laser processing machines. Specifically, in the technique described in Patent Document 1, depending on whether or not hydraulic pressure is applied, the preload of the bearing changes, the rigidity of the bearing in the radial direction changes, and the accuracy of the product, specifically, the laser beam. This can have a large impact on the accuracy of the irradiation position. In other words, it is difficult to apply the technique described in Patent Document 1 to a galvanometer scanner that drives a galvanometer mirror in a laser processing machine that requires precise position control of a laser beam, because it greatly affects the control of position accuracy. There was a problem that

The present disclosure has been made in view of the above, and an object of the present disclosure is to obtain a galvanometer scanner capable of suppressing electrolytic corrosion while suppressing displacement in the axial direction between the inner ring and the outer ring as compared with the conventional art. and

In order to solve the above-described problems and achieve the object, a galvanometer scanner according to the present disclosure includes a motor and an electrolytic corrosion suppressing section. The motor has a rotor with a permanent magnet rotating about an axis of rotation and a shaft connected to either side of the permanent magnet along the axis of rotation, and a stator positioned at a defined distance from the rotor. The electrolytic corrosion suppressing part is provided at one of the two ends of the motor in the direction of the rotation axis where the galvanomirror is not provided, and electrically connects the stator and the rotor. The electrolytic corrosion suppressing portion is in contact with the rotor and includes a grounding structure portion having a threaded outer peripheral surface, a first member having a through hole having a threaded inner peripheral surface provided on an extension of the rotating shaft, a first leg for supporting the first member at an end of the stator; and a first support structure for supporting the ground contact structure. The grounding structure is screwed into the through hole so as to be movable in the direction of the rotation axis. The ground structure and the first support structure are constructed from an electrically conductive material.

The galvanometer scanner according to the present disclosure has the effect of being able to suppress electrolytic corrosion while suppressing displacement in the axial direction between the inner ring and the outer ring compared to the conventional art.

A diagram showing an example of a configuration of a laser processing machine according to Embodiment 1. 1 is a diagram schematically showing an example of the configuration of a galvanometer scanner according to Embodiment 1; FIG. FIG. 2 is a cross-sectional view showing an example of the configuration of the grounding structure used in the galvanometer scanner according to the first embodiment; FIG. 4 is a diagram schematically showing another example of the configuration of the galvanometer scanner according to Embodiment 1; FIG. 4 is a diagram schematically showing another example of the configuration of the galvanometer scanner according to Embodiment 1;

A galvanometer scanner and a laser processing machine according to embodiments of the present disclosure will be described in detail below with reference to the drawings.

Embodiment 1.
FIG. 1 is a diagram showing an example of the configuration of a laser processing machine according to Embodiment 1. FIG. The laser processing machine 1 irradiates a pulsed laser beam L to perforate a workpiece W to be processed. An example of the workpiece W to be processed is a printed circuit board or an IC (Integrated Circuit) package substrate mounted on an electronic device or the like. The workpiece W to be processed may be any object that can be subjected to drilling processing, and may be any object other than the above-described printed circuit board and IC package substrate.

In FIG. 1, the X-axis, Y-axis and Z-axis are three axes perpendicular to each other. The X and Y axes are horizontal axes. The Z-axis is the vertical axis. The laser processing machine 1 performs a drilling process of forming a plurality of holes dispersed in the X-axis direction and the Y-axis direction at high speed.

The laser processing machine 1 includes 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, and a processing head 30 that irradiates the laser beam L at a desired position. , and a work transfer table 40 for holding the work W to be processed.

A laser oscillator 10 outputs a pulsed laser beam L. As shown in FIG. The pulsed laser beam L is, for example, infrared light. One example of laser oscillator 10 is a carbon dioxide (CO ₂ ) laser. The peak wavelength of the pulsed laser beam L falls within the range of 9.3 μm to 10.6 μm. The pulsed laser beam L is referred to as laser beam L in the following.

The laser optical element 20 shapes 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 collimating lens 21 that adjusts the aperture of the laser beam L output from the laser oscillator 10 to collimate the laser beam L, and a laser beam L that is shaped to be transferred to the workpiece W to be processed. and a mask hole 22 for cutting out. One or a plurality of collimator lenses 21 are arranged. The hole shape of the mask hole 22 is usually circular.

The processing head 30 includes galvanometer mirrors 31Y and 31X that deflect the laser beam L, galvanometer scanners 32Y and 32X that rotate the galvanometer mirrors 31Y and 31X, and an fθ lens 33 that converges the laser beam L. have.

The galvanomirror 31Y reflects the laser beam L incident on the processing head 30 . The galvanometer scanner 32Y is a servomotor used to position the galvanometer mirror 31Y. The galvanometer scanner 32Y rotates the galvanometer mirror 31Y under control according to the position command. That is, the galvanometer scanner 32Y adjusts the position and angle of the laser beam L incident on the fθ lens 33 . Specifically, the galvanometer scanner 32Y moves the irradiation position of the laser beam L in the Y-axis direction by rotating the galvanometer mirror 31Y within a specific swing angle range.

The galvanomirror 31X reflects the laser beam L incident from the galvanomirror 31Y. The galvanometer scanner 32X is a servomotor used to position the galvanometer mirror 31X. The galvanometer scanner 32X rotates the galvanometer mirror 31X under control according to the position command. That is, the galvanometer scanner 32X adjusts the position and angle of the laser beam L incident on the fθ lens 33 . Specifically, the galvanometer scanner 32X moves the irradiation position of the laser beam L in the X-axis direction by rotating the galvanometer mirror 31X within a specific swing angle range.

The f.theta.

The work carrier table 40 is moved in the X-axis direction or the Y-axis direction by control according to the position command. That is, the work transfer table 40 has a drive mechanism for the X-axis direction and a drive mechanism for the Y-axis direction. The drive mechanism for the X-axis direction and the drive mechanism for the Y-axis direction are driven according to the position command, so that the position of the work transfer table 40 can be changed within the XY plane. The movable range of the galvanometer mirrors 31Y and 31X by driving the galvanometer 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 by the galvanometer mirrors 31Y and 31X is limited to an extremely narrow range. Therefore, it is difficult to drill the entire workpiece W only by changing the irradiation positions of the galvanometer mirrors 31Y and 31X by driving the galvanometer scanners 32Y and 32X. Therefore, after finishing the machining within the movable range of the galvano mirrors 31Y and 31X by driving the galvano scanners 32Y and 32X, the position of the workpiece W to be processed is changed using the work transfer table 40, Processing is performed again within the movable range of the galvanomirrors 31Y and 31X. As a result, the entire workpiece W to be processed can be drilled.

The laser processing machine 1 further includes a control device 50 that controls the entire laser processing machine 1 . The control device 50 controls operations of the laser oscillator 10, the galvanometer scanners 32Y and 32X, the work transfer table 40, and the like. In one example, the control device 50 generates a position command for the workpiece transfer table 40, a laser output command for the laser oscillator 10, and a position command for the galvanometer scanners 32Y and 32X. A position command for the work carrier table 40 is output to the drive mechanism for the work carrier table 40 in the X-axis direction and the drive mechanism for the Y-axis direction. A laser output command is output to the laser oscillator 10 . Position commands for the galvanometer scanners 32Y and 32X are output to the galvanometer scanners 32Y and 32X. Note that the galvano-scanners 32Y and 32X are hereinafter referred to as the galvano-scanner 32 when they are not individually distinguished. Also, the galvanomirrors 31Y and 31X are referred to as galvanomirrors 31 when they are not individually distinguished.

Next, the configuration of the galvanometer scanner 32 will be described. FIG. 2 is a diagram schematically showing an example of the configuration of the galvanometer scanner according to Embodiment 1. FIG. FIG. 2 also shows the galvanometer mirror 31 fixed to the galvanometer scanner 32 . The galvanometer scanner 32 has a motor 35 and an electrolytic corrosion suppressor 37 that suppresses the occurrence of electrolytic corrosion in bearings 351 and 352 of the motor 35 . Of the two ends of the motor 35 in the direction of the rotation axis of the rotor 340 to be described later, the end on which the galvanomirror 31 is provided is referred to as the first end, and the end on which the electrolytic corrosion suppressing portion 37 is provided is referred to as the first end. is referred to as the second end.

The galvanomirror 31 is fixed to a shaft 342 of a rotor 340 of the motor 35, which is one of the two ends of the motor 35 in the direction of the rotation axis, and rotates about the rotation axis. . The galvanomirror 31 has a mirror 311 and a mirror holder 312 . A mirror 311 is fixed to a mirror holder 312 . The mirror holder 312 is fixed to the shaft 342 of the motor 35 and holds the mirror 311 . The mirror 311 reflects the incident laser beam L. As shown in FIG. The galvanomirror 31 rotates in conjunction with the shaft 342 to deflect the laser beam L to an arbitrary angle. Generally, it is sufficient if the rotation angle of the galvanomirror 31 is about ±20 degrees.

The motor 35 has a stator 330 , a rotor 340 and a pair of bearings 351 and 352 . Stator 330 is made of a conductive material. The stator 330 has a housing portion 331 , an iron core 332 , coils 333 and conductors 334 . The housing part 331 accommodates an iron core 332 , a coil 333 , a rotor 340 and a pair of bearings 351 and 352 . The housing part 331 has a hollow structure capable of accommodating the rotor 340 inside. The housing part 331 is made of a conductive material. The iron core 332 is a tubular member for generating torque of the motor 35 . Iron core 332 is preferably a ferromagnetic material such as iron. The coil 333 is arranged along the inner peripheral surface of the iron core 332 and has a tubular shape. A cylindrical coil 333 is arranged inside a cylindrical iron core 332 . A lead wire 334 is a wiring that electrically connects a current amplifier (not shown) and the coil 333 , and passes current from the current amplifier to the coil 333 . By applying current to conductor 334 , rotor 340 rotates and motor 35 can be driven.

Rotor 340 is made of a conductive material. The rotor 340 has a permanent magnet 341 and shafts 342 and 343 . A permanent magnet 341 is placed inside the cylindrical coil 333 at a defined distance from the coil 333 . In one example, the permanent magnet 341 has a cylindrical shape, and different magnetic poles are alternately arranged in the circumferential direction. The permanent magnet 341 is rotatable around the central axis of the tubular coil 333 . A central axis of the tubular coil 333 corresponds to the rotation axis. Shafts 342 and 343 are connected to both sides along the rotation axis of the permanent magnet 341 . The permanent magnet 341 and the shafts 342, 343 may be integrally formed or may be connected by a method such as welding. A galvanomirror 31 is fixed to one end of the shaft 342 . The other shaft 343 protrudes from the end of the housing portion 331 of the stator 330 . The shafts 342 and 343 rotate together with the rotation of the permanent magnet 341, thereby rotating the galvanomirror 31 around the rotation axis.

A pair of bearings 351 and 352 rotatably hold shafts 342 and 343 inside the housing portion 331 . In one example, the bearings 351, 352 are rolling bearings having an outer ring fixed to the housing portion 331, an inner ring holding the shafts 342, 343, and rolling elements held between the inner ring and the outer ring. . An oil film is spread between the inner and outer rings and the rolling elements. Due to the rotation of the permanent magnet 341 of the rotor 340, the inner ring holding the shafts 342 and 343 fixed to the permanent magnet 341 rotates about the rotation axis with respect to the outer ring fixed to the housing portion 331. Become. At this time, the rolling elements also rotate.

The electrolytic corrosion suppressing portion 37 is provided on the second end side of the two ends of the motor 35 in the direction of the rotation axis where the galvanomirror 31 is not provided, and electrically connects the stator 330 and the rotor 340 together. connect to. Specifically, the electrolytic corrosion suppressing portion 37 is provided at the end portion of the stator 330 opposite to the galvanomirror 31 . Electrolytic corrosion suppressing portion 37 is a member that electrically connects stator 330 and rotor 340, that is, a member that makes stator 330 and rotor 340 at the same potential. The electrolytic corrosion suppressing portion 37 has a support structure portion 370 electrically connected to the stator 330 and a ground structure portion 380 electrically connecting the stator 330 and the support structure portion 370 to the rotor 340 .

Support structure 370 supports ground structure 380 at the second end of stator 330 . Specifically, the support structure 370 is provided at a second end of the stator 330 opposite to the first end where the galvanomirror 31 is installed. The support structure 370 has a plate member 371 and legs 372 . The plate-like member 371 is a plate-like member arranged perpendicular to the rotation axis and corresponds to the first member. A through hole 371a for supporting the grounding structure portion 380 is provided at a position of the plate-like member 371 that intersects the rotational axis, which is an imaginary straight line. The inner peripheral surface of the through hole 371a is threaded to form a female thread. The leg portion 372 is a member that supports the plate member 371 at the end portion of the stator 330 . The leg portion 372 may be a tubular member or a rod-shaped member extending in the direction of the rotation axis. In the latter case, plate-like member 371 may be supported at the end of stator 330 by two or more rod-like members. In one example, the leg portion 372 is fixed to the housing portion 331 of the stator 330 by a fixing method such as screws or welding. Also, the leg portion 372 is fixed to the plate-like member 371 by a fixing method such as screws or welding. The plate-like member 371 and the leg portion 372 are, for example, made of a conductive material such as stainless steel.

Grounding structure 380 is a member made of an electrically conductive material that abuts rotor 340 at one end and is supported by support structure 370 at the other end. In the example of FIG. 2 , one end of the grounding structure 380 is arranged in a through hole 371 a provided in the plate-like member 371 of the support structure 370 . Specifically, the grounding structure 380 is arranged so that one end is fixed to the through hole 371 a of the plate-like member 371 and the other end is in contact with the shaft 343 of the rotor 340 . The outer peripheral surface of the grounding structure portion 380 is threaded to form a male thread. The ground structure portion 380 can be fixed to the support structure portion 370 by screwing the ground structure portion 380 into the through hole 371a. It is desirable that the grounding structure 380 have a configuration that maintains electrical connection with the shaft 343 even when the shaft 343 rotates. Ground structure 380 may be a needle-like member or a ball plunger, in one example. In one example, the grounding structure 380 is made of stainless steel.

FIG. 3 is a cross-sectional view showing an example of the configuration of the grounding structure used in the galvanometer scanner according to the first embodiment. FIG. 3 shows a case where the ground structure 380 is a ball plunger. The grounding structure 380 includes a spherical member 381 made of a conductive material, an elastic member 382 made of a conductive material, disposed in contact with the spherical member 381, and containing the spherical member 381 and the elastic member 382. , and a housing 383 made of a conductive material. Inside the housing 383 , one end of the elastic member 382 is fixed inside the housing 383 and the other end contacts the spherical member 381 . The spherical member 381 is not fixed to the elastic member 382 and is only in contact therewith. Also, the spherical member 381 contacts the shaft 343 of the rotor 340 . Thereby, the spherical member 381 rotates in conjunction with the rotation angle of the rotor 340 . That is, when the shaft 343 of the rotor 340 in contact with the spherical member 381 rotates, the spherical member 381 also rotates. As a result, smooth rotation of the rotor 340 is realized. The spherical member 381 corresponds to the second member.

Also, the spherical member 381 is movable so as to be in constant contact with the rotor 340 . This makes it possible to adjust the pressing force with which the spherical member 381 pushes the rotor 340 in the direction of the rotation axis. In one example, the spherical member 381 can be pressed against the rotor 340 under the condition that the positional accuracy of the laser beam L reflected by the galvanomirror 31 caused by pushing the rotor 340 in the direction of the rotation axis does not deteriorate. In addition, the galvanometer scanner 32 can be used while ensuring contact reliability between the spherical member 381 and the rotor 340 .

Furthermore, since the spherical member 381 is in contact with the elastic member 382 while the spherical member 381 is rotating, it can move in the direction of the rotation axis so as to contact the rotor 340 . That is, the elastic member 382 contacts the spherical member 381 and presses the spherical member 381 toward the rotor 340 . Thereby, the spherical member 381 can be kept in contact with the rotor 340 at all times by the elastic member 382 . Thus, electrical contact can be maintained between the spherical member 381 and the elastic member 382, and electrical contact can be maintained between the rotor 340 and the stator 330 via the ground structure 380 and the support structure 370. becomes.

As described above, the elastic member 382 presses the spherical member 381 with a force sufficient to maintain contact between the spherical member 381 and the rotor 340 . The pressing force, which is the force generated by the displacement of the elastic member 382, pushes the rotor 340 of the motor 35 in the direction of the rotation axis, and does not become large enough to displace the rotor 340 with respect to the stator 330 in the direction of the rotation axis. adjusted to The elastic member 382 is a spring in one example.

The operation of such a galvanometer scanner 32 will be described. When current is applied to coil 333 according to an instruction from control device 50, rotor 340 rotates. As the rotor 340 rotates, the galvanomirror 31 fixed to the shaft 342 also rotates. At the second end of the motor 35 opposite to the first end where the galvanomirror 31 is installed, the grounding structure 380 is in contact with the other shaft 343 . In other words, rotor 340 and stator 330 are electrically connected via grounding structure 380 and support structure 370, and rotor 340 and stator 330 are at the same potential. Therefore, the occurrence of axial voltage, which is a potential difference, between the inner and outer rings of the bearings 351 and 352 due to the influence of eddy currents of the magnets when the galvano scanner 32 is driven is suppressed. In addition, even if the inner ring and the outer ring are insulated by the oil film of the bearings 351 and 352 and the oil film breaks and the inner ring and the outer ring come into contact with each other, the inner ring and the outer ring are prevented from being subjected to electrolytic corrosion suppression. Since they have the same potential through the portion 37, the occurrence of discharge between the inner ring and the outer ring is suppressed. As a result, damage inside the bearings 351 and 352 is suppressed. Since damage inside the bearings 351 and 352 is suppressed, smooth rotation of the bearings 351 and 352 can be continued, and control of the irradiation position of the laser beam L is not adversely affected.

Note that the structure is not limited to that shown in FIG. 2 as long as electrical contact between rotor 340 and stator 330 is maintained by electrolytic corrosion suppressing portion 37 . In FIG. 2 , the area of the plate member 371 of the electrolytic corrosion suppressing portion 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 can maintain connection with the shaft 343 and the plate-like member 371 can support the grounding structure 380, the area of the plate-like member 371 in the direction perpendicular to the rotation axis can be increased. The width and shape are not particularly limited.

Further, in order to stabilize the pressing force of the elastic member 382 of the grounding structure 380, it is necessary to firmly determine the position of the housing 383 of the grounding structure 380 in the direction of the rotation axis. For example, even if the grounding structure 380 is fixed to the plate-like member 371 as shown in FIG. may move to As described above, when the position of the housing 383 in the direction of the rotation axis changes, the fixing position of the elastic member 382 also changes, and the magnitude of the pressing force also changes. That is, the pressing force by the elastic member 382 becomes unstable. Therefore, the position of the elastic member 382 may be fixed so that the spherical member 381 can always be brought into contact with the rotor 340 with a predetermined pressing force.

4 is a diagram schematically showing another example of the configuration of the galvanometer scanner according to Embodiment 1. FIG. The same symbols are attached to the same components as those described above, and the description thereof is omitted. In FIG. 4, the length of the ground structure portion 380a is longer than the thickness of the plate member 371. In FIG. 2 shows the case where the end of the grounding structure 380 on the side opposite to the motor 35 is inside the through hole 371a of the plate-like member 371, but in FIG. 371 through a through hole 371a. 4 further includes a nut 385 which is a positioning member for suppressing the movement of the grounding structure 380a in the direction of the rotating shaft and determining the fixed position of the elastic member 382. As shown in FIG. Although not shown, since the outer peripheral surface of the grounding structure portion 380a is threaded as described above, a nut 385 is screwed to the portion protruding from the plate-like member 371. As shown in FIG. As a result, the movement of the grounding structure portion 380a in the direction of the rotating shaft is suppressed, and the fixed position of the elastic member 382 is stabilized. As a result, it is possible to keep the spherical member 381 in contact with the rotor 340 at all times with a predetermined pressing force.

FIG. 5 is a diagram schematically showing another example of the configuration of the galvanometer scanner according to Embodiment 1. FIG. The same symbols are attached to the same components as those described above, and the description thereof is omitted. The electrolytic corrosion suppressing portion 37 of FIG. 5 further has a ground structure fixing portion 390 in addition to the structure shown in FIG. The grounding structure fixing portion 390 is provided on the opposite side of the support structure 370 to the motor 35 and is a member that fixes the grounding structure 380 so that its position in the direction of the rotation axis does not move. The ground structure fixing portion 390 corresponds to the positioning member. The ground structure fixing portion 390 has a support structure portion 391 and a position fixing portion 395 .

The support structure 391 has a plate member 392 and legs 393 . The plate-like member 392 is a plate-like member arranged so as to be perpendicular to the rotation axis. A through hole 392 a that supports the position fixing portion 395 is provided at a position of the plate-like member 392 that intersects the rotation axis, which is an imaginary straight line. The through hole 392a is a threaded hole, and the inner peripheral surface of the through hole 392a is threaded to form a female thread. The leg portion 393 is a member that supports the plate-like member 392 with the plate-like member 371 of the support structure portion 370 . The leg portion 393 may be a tubular member or a rod-shaped member extending in the direction of the rotation axis. In the latter case, the plate-like member 392 may be supported by the plate-like member 371 of the support structure 370 by two or more rod-like members. In one example, the leg portion 393 is fixed to the plate-like member 371 of the support structure portion 370 by a fixing method such as screws or welding. Also, the leg portion 393 is fixed to the plate member 392 by a fixing method such as screws or welding.

The position fixing portion 395 is a member that abuts on one end portion of the grounding structure portion 380 and is supported by the support structure portion 391 on the other end portion. In one example, the position fixing portion 395 is a member that extends in the direction of the axis of rotation. In the example of FIG. 5 , the position fixing portion 395 is arranged so that one end is fixed to the through hole 392 a of the plate-like member 392 and the other end is in contact with the ground structure portion 380 . The outer peripheral surface of the position fixing portion 395 is threaded to form a male screw. The position fixing part 395 can be fixed to the support structure part 391 by screwing the position fixing part 395 into the through hole 392a. Thereby, the grounding structure 380 is pushed by the position fixing part 395 from the side opposite 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, it is possible to keep the spherical member 381 in contact with the rotor 340 at all times with a predetermined pressing force.

As described above, the galvanometer scanner 32 of the first embodiment includes a rotor 340 having a permanent magnet 341 rotating around the rotation axis and shafts 342 and 343 connected to both sides of the permanent magnet 341 along the rotation axis. A stator 330 arranged at a defined distance from 340 and a motor 35 with bearings 351, 352 supporting shafts 342, 343 and galvanometer mirrors in the two ends of the motor 35 in the direction of the axis of rotation. and an electrolytic corrosion suppressing portion 37 that is provided at the end portion where the stator 31 is not provided and electrically connects the stator 330 and the rotor 340 . As a result, when the galvano scanner 32 operates, the electrolytic corrosion suppressing portion 37 electrically connects the stator 330 and the rotor 340, so that the inner and outer rings of the bearings 351 and 352 are at the same potential. Further, the electrolytic corrosion suppressing portion 37 contacts the rotor 340 with such a pressing force as to keep the rotor 340 in contact with the shaft 343 . Therefore, the occurrence of electrolytic corrosion between the inner and outer rings of the bearings 351 and 352 is suppressed while suppressing the displacement in the direction of the rotation axis between the inner and outer rings of the bearings 351 and 352 compared to the conventional art. It has the effect of being able to

In the conventional technology, thrust force is applied to the rotor shaft by hydraulic pressure until the oil film surrounding the rolling elements of the bearings 351 and 352 is cut off, and the inner rings, rolling elements, and outer rings are electrically connected. Removes thrust force. In other words, the control is performed in two ways, that is, ON to apply the thrust force or OFF to not apply the thrust force. When such a conventional technique is applied to the galvanometer scanner 32 that requires strict positioning accuracy, the rotor 340 is displaced in the direction of the rotation axis when it is turned on, and the galvanometer mirror 31 is also displaced in the direction of the rotation axis. put away. When such a displacement occurs, the positional accuracy of the laser beam L reflected by the galvanomirror 31 deteriorates. When switching from on to off, the rotor 340 is also displaced in the direction of the rotation axis, similarly degrading the positional accuracy. On the other hand, in the galvano-scanner 32 of Embodiment 1, the grounding structure portion 380 of the electrolytic corrosion suppressing portion 37 does not need to be pushed with such a strong force because it is sufficient to establish electrical continuity between the rotor 340 and the stator 330. Instead, it is sufficient that the contact between the ground contact structure portion 380 and the rotor 340 is always maintained. Therefore, the pressing force in the direction of the rotation axis of the first embodiment is weaker than the thrust force of the conventional technology, and the positional accuracy of the laser beam L reflected by the galvanomirror 31 is not adversely affected. Further, in Embodiment 1, the inner rings, rolling elements and outer rings of the bearings 351 and 352 are not positively connected, and the rolling elements are used in a state where they are covered with an oil film. The occurrence of electrolytic corrosion between the inner and outer rings of 351 and 352 can be suppressed.

Furthermore, as shown in FIGS. 4 and 5, the electrolytic corrosion suppressing portion 37 is a positioning member that fixes the elastic member 382 at a position other than the position where the elastic member 382 in the grounding structure portion 380 contacts the spherical member 381. was further prepared. Thereby, the position of the elastic member 382 is fixed, and the pressing force can be stabilized.

The configurations shown in the above embodiments are only examples, and can be combined with other known techniques, or can be combined with other embodiments, without departing from the scope of the invention. It is also possible to omit or change part of the configuration.

1 laser processing machine, 10 laser oscillator, 20 laser optical element, 21 collimator lens, 22 mask hole, 30 processing head, 31, 31X, 31Y galvano mirror, 32, 32X, 32Y galvano scanner, 33 fθ lens, 35 motor, 37 Electrolytic corrosion suppressing part 40 Work transfer table 50 Control device 311 Mirror 312 Mirror holder 330 Stator 331 Case part 332 Iron core 333 Coil 334 Lead wire 340 Rotor 341 Permanent magnet 342, 343 Shaft, 351,352 bearings 370,391 support structure 371,392 plate member 371a,392a through hole 372,393 leg 380,380a grounding structure 381 spherical member 382 elastic member 383 housing 385 nut, 390 grounding structure fixing part, 395 position fixing part, L laser beam, W workpiece to be processed.

Claims (9)

a motor having a rotor having a permanent magnet rotating about an axis of rotation and a shaft connected to each side of the permanent magnet along the axis of rotation, and a stator positioned at a defined distance from the rotor;
an electrolytic corrosion suppressing portion provided at one of the two ends of the motor in the direction of the rotation axis where the galvanomirror is not provided and electrically connecting the stator and the rotor;
with
The electrolytic corrosion suppressing section is
a grounding structure that abuts on the rotor and has a threaded outer peripheral surface;
a first member having a threaded through hole on the inner peripheral surface provided on an extension line of the rotating shaft; and a first leg supporting the first member at an end of the stator, a first support structure supporting the ground structure;
has
the ground structure portion is screwed into the through hole so as to be movable in the direction of the rotation axis;
A galvanometric scanner , wherein the ground structure and the first support structure are constructed of an electrically conductive material . 2. The galvano-scanner according to claim 1 , wherein the grounding structure has a second member that contacts the rotor. 3. The galvanometer scanner according to claim 2 , wherein said second member is movable in the direction of said rotating shaft so as to come into contact with said rotor. 4. The galvanometer scanner according to claim 3 , wherein the grounding structure further comprises an elastic member that contacts the second member and presses the second member toward the rotor. the grounding structure further has a housing that accommodates the second member and the elastic member;
The thread is cut on the outer peripheral surface of the housing,
A contact position inside the housing between the end portion of the elastic member that is not the end portion that contacts the second member and the housing is not changed by screwing the grounding structure portion into the through hole. 5. The galvanometer scanner of claim 4, characterized by: 5. The galvanometer scanner according to claim 4 , wherein the electrolytic corrosion suppressing section further includes a positioning member that fixes the elastic member at a position other than a position that contacts the second member. the length of the ground structure is longer than the thickness of the first member;
7. The galvanometer scanner according to claim 6, wherein the positioning member is a nut that is screwed into the ground structure portion at a position on the side of the first member opposite to the motor. The positioning member is
a position fixing portion abutting the end portion of the ground structure portion and having a threaded outer peripheral surface;
A plate-like member having a threaded through hole on the inner peripheral surface provided on an extension line of the rotating shaft, and a second leg supporting the plate-like member with the first support structure. , a second support structure for supporting the position fixing part;
has
7. The galvanometer scanner according to claim 6, wherein the position fixing portion is screwed into the through hole of the plate member. a laser oscillator that emits a laser beam;
a lens for condensing the laser beam and irradiating the laser beam onto a processing object;
The galvanometer scanner according to any one of claims 1 to 8, which adjusts the position and angle of incidence of the laser beam on the lens;
Of the two ends of the motor in the direction of the rotation axis of the galvanometer scanner, the end not provided with the electrolytic corrosion suppressor is fixed to the shaft and rotates about the rotation axis. galvanomirror and
A laser processing machine comprising:

Images