JP2016178749A - Linear actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear actuator which can increase rigidity without influencing magnetic circuit characteristic of a drive coil.SOLUTION: A linear actuator includes: a movable part having a cylindrical movable body around which a drive coil is wound in a circumferential direction of an outer peripheral surface; a stator having a magnetic substance and a fixing plate; a linear guide which is arranged inside the movable body and capable of linear movement along a guide rail; and a position detector which is arranged on an outer peripheral surface or an inner peripheral surface of the movable body and detects a relative position in a linear movement direction of the movable body with respect to the stator. There are provided: a fitting member to which members to be moved together with the movable body are fitted; and a coupling member for connecting the movable part between the position detector and the fitting member. The fixing plate has an open hole having a slit shape in the moving direction of the movable body. The open hole inserts the coupling member.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a linear actuator. In particular, the present invention relates to a linear actuator used for moving a marking head of a laser marking device that prints characters or the like on the surface of a workpiece.

  In the laser marking device, a linear actuator that uses a voice coil motor to move a lens or the like with good responsiveness to perform focusing is used. A linear actuator using a voice coil motor includes a mover having a drive coil and a stator having a magnet, and the mover is supported by the stator so as to be linearly movable by a linear guide. A lens frame for holding the lens is attached to the mover, and the lens moves as the mover moves linearly. By controlling the magnitude of the current excited in the drive coil, the mover can move linearly along its central axis, and the focus of the lens held in the lens frame can be adjusted. Yes.

  In such a linear actuator, when the minute range is moved linearly, high positioning accuracy is required with high responsiveness. For example, Patent Document 1 discloses a linear actuator that precisely controls the position by accurately grasping the position of the movable element by providing the movable element with a position detection mechanism.

JP 2008-035645 A JP 2014-1117024 A

  Factors that lower the positioning accuracy of the linear actuator include distortion and deformation of the mover. However, in a linear actuator using a voice coil motor, the radial thickness of the drive coil greatly affects the characteristics of the magnetic circuit of the mover. Therefore, there is a problem that it is difficult to adopt a method of suppressing distortion and deformation by increasing the thickness of the mover and increasing the rigidity of the mover.

  In particular, when the position detection mechanism is attached to the mover in addition to a member to be moved such as a lens, the weight of the entire mover increases, and the mover may be distorted or deformed. In such a case, it becomes difficult to maintain a precise distance between the position detection mechanism and a member to be moved such as a lens, and the positioning accuracy may be reduced. In addition, deformation of the mover may cause malfunction or failure of the mover itself.

  Patent Document 2 discloses a linear motor in which end plates are provided on the front and rear open surfaces of the frame of the mover to increase the rigidity of the motor mover. However, in the linear motor of Patent Document 2, an end plate is provided on the open surface of the mover, and by providing the end plate, the lens mounting portion 14 and the position detector 5 are avoided while avoiding the end plate in the range of movement of the mover. It becomes difficult to shield light between the two. Therefore, there is a problem that light reflected before and after the lens mounting portion 14 enters the position detector 5 and is easily detected as noise.

  Further, as in Patent Document 2, in the configuration in which the end plates are provided on the front and rear open surfaces of the movable element frame, when the linear guide is to be provided on the inner side of the movable element, a hole is formed in the end plate to A part needs to be fixed to the stator. Therefore, when assembling property is considered, it is necessary to provide a linear guide outside the movable element as in Patent Document 2.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a linear actuator that can increase the rigidity of the mover without affecting the magnetic circuit characteristics of the drive coil.

  In order to achieve the above object, a linear actuator according to a first aspect of the present invention includes a movable portion having a cylindrical mover around which a drive coil is wound in the circumferential direction of an outer peripheral surface, and a predetermined gap from the outer peripheral surface of the mover. And a stator having a magnetic body disposed outside the movable element and a stationary plate disposed so as to pass through the interior of the movable element, and disposed on the inner side of the movable element and attached to the stationary plate. A linear guide having a guide rail extending in a moving direction of the movable element, a guide block attached to the movable element and linearly movable along the guide rail, and an outer peripheral surface or an inner peripheral surface of the movable element A position detection device that is disposed on a surface and detects a relative position of the mover with respect to the stator in a linear movement direction; and a position detection device that is perpendicular to the linear movement direction of the mover. Is located on the outer peripheral surface or inner peripheral surface of the mover at a position facing the center of the mover, and an attachment member to which a member to be moved is attached together with the mover. The mover is arranged inside the mover, and supports the mover in the direction in which the position detection device is arranged and the direction in which the mounting member is arranged from the inside of the mover, and the position detection device. A coupling member for coupling the movable part to the mounting member, and the fixed plate has a through-hole having a slit shape in the moving direction of the movable element, The coupling member is inserted.

  In the first invention, from the inside of the mover, the mover is supported in the direction in which the position detection device is arranged and the direction in which the attachment member is arranged, and the movable part between the position detection device and the attachment member is coupled. By providing the coupling member for the purpose, the rigidity between the position detection device and the mounting member can be increased. Further, the fixed plate has a through hole having a slit shape in the moving direction of the mover, and since the coupling member is inserted into the through hole, the relative position between the mover and the stator by the position detection device is increased. The accuracy of position detection can be increased, and the positioning accuracy of the movement target member attached to the attachment member can be increased.

  The linear actuator according to a second invention is the linear actuator according to the first invention, wherein the position detection device is an optical position detection device, and the position detection is performed on the inner peripheral surface side of the mover via the through hole. It is preferable to provide a light shielding plate that blocks light passing through the apparatus.

  In the second invention, an optical position detection device is used as the position detection device. For example, a light emitting part such as an LED (Light Emitting Diode) is attached to the outer peripheral surface of the mover, and a light receiving part such as a PSD (Position Sensitive Detector) is attached to the opposite face of the stator, and the movable part is movable based on the output signal of the light receiving part The relative position of the child with respect to the stator can be detected. Therefore, when disturbance light is incident on the light receiving unit, there is a risk of erroneous detection. In particular, when an optical system member such as a lens or a light source is attached to the mounting member, light emitted from the optical system member and scattered light pass through a through-hole provided in the fixed plate, and the light receiving unit of the position detection device There is a risk of reaching. However, by providing a light shielding plate on the inner peripheral surface side of the mover, light that passes through the through hole and enters the position detection device can be blocked, and it is possible to prevent erroneous detection from occurring. It becomes.

  The linear actuator according to a third aspect of the present invention is the linear actuator according to the first aspect, wherein the position detection device is an optical position detection device, between the fixed plate and the position detection device, It is preferable to include a light shielding plate that covers the through hole of the fixed plate in a plan view as viewed from above.

  In the third invention, an optical position detection device is used as the position detection device. Light that passes between the fixed plate and the position detection device and is incident on the position detection device through the through hole by providing a light shielding plate that covers the through hole of the fixed plate in a plan view as viewed from the upper surface of the mover. It is possible to prevent the occurrence of false detection.

  Moreover, the linear actuator which concerns on 4th invention is 2nd or 3rd invention. WHEREIN: It is preferable that the said light shielding plate is arrange | positioned in contact with the internal peripheral surface of the said needle | mover.

  In the fourth invention, since the light shielding plate is disposed in contact with the inner peripheral surface of the mover, light leakage hardly occurs from the gap with the mover.

  The linear actuator according to a fifth aspect of the present invention is the linear actuator according to any one of the first to fourth aspects, wherein the position detecting device and the mounting member are disposed at positions facing each other with the linear guide interposed therebetween. preferable.

  In the fifth invention, since the position detection device and the mounting member are disposed at positions facing each other with the linear guide interposed therebetween, the rigidity between the position detection device and the mounting member coupled by the coupling member is increased, The rigidity of the mover can be increased. By increasing the rigidity of the mover, the natural frequency of the mover can be increased and the responsiveness can be increased. In addition, it is possible to suppress malfunctions and failures of the linear actuator. In particular, even when the weight of the mover is increased by attaching a position detection device or an attachment member, the rigidity of the entire mover can be increased by the coupling member, so that deformation and damage of the mover are suppressed. It becomes possible.

  The linear actuator according to a sixth aspect of the present invention is the linear actuator according to any one of the first to fifth aspects, wherein the stator has a plurality of inner yokes, and the fixing plate fixes the plurality of inner yokes. And it is preferable that the said through-hole is arrange | positioned between these inner yokes.

  In the sixth invention, the stator has a plurality of inner yokes, and the fixing plate fixes the plurality of inner yokes, and the through holes are arranged between the plurality of inner yokes. Has little effect on

  The linear actuator according to a seventh aspect of the present invention is the linear actuator according to any one of the first to sixth aspects, wherein the linear guide is disposed on an upper surface of the mounting member, and a plurality of support members are provided on the left and right of the linear guide. Preferably, the linear plate is disposed in contact with the linear guide, and the fixed plate is disposed on an upper surface of the linear guide.

  In the seventh invention, the linear guide is disposed on the upper surface of the mounting member, and a plurality of support members are disposed on the left and right sides of the linear guide so as to contact the linear guide, and a fixed plate is disposed on the upper surface of the linear guide. Therefore, it has a structure that prevents light from leaking.

  The linear actuator according to an eighth aspect of the present invention is the linear actuator according to any one of the first to seventh aspects, wherein the position detection device includes a light emitting unit and a light receiving unit, and either the light emitting unit or the light receiving unit. It is preferable that one is disposed on the mover and the other is disposed on the stator.

  In the eighth invention, the position detection device has a light emitting part and a light receiving part, and either the light emitting part or the light receiving part is arranged on the mover and the other is arranged on the stator. The position can be detected by changing the amount of received light according to the movement.

  A linear actuator according to a ninth aspect of the present invention is the linear actuator according to any one of the first to eighth aspects, wherein the movable element has a rectangular cylindrical shape, and is a cross-sectional view taken along a plane perpendicular to the linear movement direction of the movable element. A plurality of inner yokes, each having an upper surface, a lower surface, a left surface, and a right surface, wherein the stator is disposed with a gap between each of the left surface and the right surface inside the mover, and connected by the fixed plate; The left and right surfaces outside the mover are arranged with a gap, respectively, and the plurality of inner yokes and a plurality of outer yokes connected at the ends of the mover in the linear movement direction, The position detecting device is disposed on an outer peripheral surface of the upper surface of the movable element, the light shielding plate is disposed on an inner peripheral surface of the upper surface of the movable element, and the mounting member is an inner peripheral surface of the lower surface of the movable element. The linear guide is disposed on the upper surface of the mounting member, and the coupling member is inserted through the through hole of the fixing plate to couple the upper surface of the mounting member and the lower surface of the light shielding plate. It is preferable.

  In the ninth invention, the mover has a rectangular cylindrical shape, and has an upper surface, a lower surface, a left surface, and a right surface in a cross-sectional view taken along a plane perpendicular to the linear movement direction of the mover. The stator is arranged with a gap between each of the left and right surfaces inside the mover, and has a plurality of inner yokes connected by a fixed plate, and with a gap between each of the left and right surfaces outside the mover, and a plurality of inner yokes. And a plurality of outer yokes connected at the ends of the mover in the linear movement direction. The position detection device is disposed on the outer peripheral surface of the upper surface of the mover, the light shielding plate is disposed on the inner peripheral surface of the upper surface of the mover, and the attachment member is disposed on the inner peripheral surface of the lower surface of the mover. The linear guide is disposed on the upper surface of the mounting member, and the coupling member is inserted through the through hole of the fixing plate and couples the upper surface of the mounting member and the lower surface of the light shielding plate. The rigidity between the two can be increased.

  In the linear actuator according to a tenth aspect of the present invention, in any one of the first to ninth aspects, the mounting member is preferably a lens frame that can accommodate a lens that performs laser beam focus adjustment.

  In the tenth aspect of the invention, since the mounting member is a lens frame that can accommodate the lens, the lens that adjusts the focus of the laser beam can be a moving object. For example, as a linear actuator for a Z-axis scanner of a laser marking device It can be used.

  According to the present invention, it is possible to provide a linear actuator that maintains high rigidity between the mover and a member attached to the mover without affecting the magnetic circuit of the drive coil, and has excellent responsiveness and positioning accuracy. It becomes possible.

It is a block diagram showing typically the composition of the laser marking device to which the linear actuator concerning an embodiment of the invention is applied. It is a block diagram which shows the structure in the case of using the solid state laser marker of the laser marking apparatus to which the linear actuator which concerns on embodiment of this invention is applied. It is a block diagram which shows the structure in the case of using the fiber laser marker of the laser marking apparatus to which the linear actuator which concerns on embodiment of this invention is applied. It is a partially broken plan view of the linear actuator according to the first embodiment of the present invention. It is the longitudinal cross-sectional view cut | disconnected by the VV line | wire in FIG. It is a schematic diagram for demonstrating operation | movement of the linear actuator which concerns on Embodiment 1 of this invention. It is a schematic diagram for demonstrating operation | movement of the linear actuator which concerns on Embodiment 1 of this invention. It is a schematic diagram for demonstrating operation | movement of the linear actuator which concerns on Embodiment 1 of this invention. It is explanatory drawing of the linear actuator which concerns on Embodiment 2 of this invention. It is the longitudinal cross-sectional view cut | disconnected by the XX line of FIG. It is explanatory drawing of the linear actuator which concerns on Embodiment 3 of this invention. It is explanatory drawing of the linear actuator which concerns on Embodiment 4 of this invention. It is explanatory drawing of the linear actuator which concerns on Embodiment 5 of this invention. It is explanatory drawing of the other structure of the linear actuator which concerns on Embodiment 5 of this invention. It is a partial schematic cross section which shows the coupling | bonding state of the light-shielding plate and stator of the linear actuator which concerns on embodiment of this invention.

  Hereinafter, a linear actuator according to an embodiment of the present invention will be specifically described with reference to the drawings. First, a laser marking device to which the linear actuator of the present invention is applied will be described. FIG. 1 is a block diagram schematically showing a configuration of a laser marking device to which a linear actuator according to an embodiment of the present invention is applied.

  As shown in FIG. 1, a laser marking device 10 includes a marking head 1, a controller 2 that controls the operation of the marking head 1, and a print data generation device 3 that is connected so as to be able to perform data communication with the controller 2. It consists of The print data generation device 3 transmits the print data to the controller 2 as expanded data. The print data generation device 3 is preferably composed of a computer, a programmable logic controller (PLC) or the like in which a program for generating development data is installed.

  Various external devices 4 are connected to the controller 2 as necessary. Examples of the external device 4 include an image recognition device 401 such as an image sensor for confirming the type and position of the workpiece W conveyed on the line, a displacement meter for acquiring information on the distance between the workpiece W and the marking head 1, and the like. The distance measuring device 402, the PLC 403 that controls the device according to a predetermined sequence, a PD (Photodiode) sensor that detects the passage of the workpiece W, various other sensors, and the like can be exemplified.

  The laser marking device 10 sets a print pattern to be printed on the surface of the workpiece W and prints on the surface of the workpiece W. Characters to be printed include characters, symbols, figures, etc., specifically hiragana, katakana, kanji, alphabet, numbers, symbols, pictograms, icons, logos, barcodes, two-dimensional codes, etc. Includes graphics.

  FIG. 2 is a block diagram showing a configuration of the laser marking device 10 to which the linear actuator according to the embodiment of the present invention is applied when a solid-state laser marker is used. The laser marking device 10 includes a controller 2 (including a laser light generation unit 200 and a laser light control unit 201) and a marking head 1 (laser output unit 202), and a laser of a laser oscillation unit 204 included in the laser output unit 202. The laser beam Lb oscillated by the medium 206 is scanned on the surface of the work W in a two-dimensional manner to print on the surface of the work W. The print signal for controlling the print operation is an on / off signal of the laser beam Lb, and is a PWM signal corresponding to one pulse of the laser beam Lb from which one pulse is oscillated. The PWM signal can define the laser intensity based on a duty ratio corresponding to the frequency. As a modification, the laser intensity may be defined by the scanning speed based on the frequency.

  The laser light generation unit 200 includes a laser excitation light source 208 and a condensing unit 210, and a constant pressure power source is supplied from the power source to the laser excitation light source 208. The laser excitation light source 208 is constituted by a semiconductor laser, a lamp, or the like. Specifically, the laser excitation light source 208 is configured by a laser diode array in which a plurality of semiconductor laser diode elements are arranged in a straight line, and laser oscillation from each element is output in a line shape. Is incident on.

The laser beam generator 200 and the laser output unit 202 are connected by an optical fiber cable 212, and the laser excitation light generated by the laser beam generator 200 is incident on the laser medium 206 described above. The laser medium 206 is composed of a rod-shaped solid laser medium (for example, Nd: YVO ₄ ), is excited by inputting laser excitation light from one end face, and emits a laser beam Lb from the other end face, so-called end pumping. The excitation method by is adopted. The laser medium 206 may be configured such that the wavelength of the emitted laser beam Lb can be converted into an arbitrary wavelength by combining a wavelength conversion element with the solid-state laser medium.

  The laser medium 206 may be composed of a wavelength conversion element that performs only wavelength conversion without using a resonator that oscillates a laser beam, instead of the solid-state laser medium described above. In this case, wavelength conversion may be performed on the output light of the semiconductor laser.

Examples of the wavelength conversion element include KTP (KTiPO ₄ ), organic nonlinear optical materials and other inorganic nonlinear optical materials such as KN (KNbO ₃ ), KAP (KAsPO ₄ ), BBO, LBO, and bulk polarization inversion elements (LiNbO). ₃ (Periodically Poled Lithium Niobate: PPLN), LiTaO _3, etc.) can be used. Further, a semiconductor laser for an excitation light source of a laser by up-conversion using a fluoride fiber doped with rare earth such as Ho, Er, Tm, Sm, and Nd can be used.

  The laser output unit 202 includes the above-described laser oscillation unit 204 that oscillates the laser beam Lb. The laser oscillation unit 204 includes an output mirror and a total reflection mirror that face each other at a predetermined distance along the optical path of the stimulated emission light emitted from the laser medium 206 described above, an aperture disposed between them, and a Q A switch is provided. The stimulated emission light emitted from the laser medium 206 is amplified by multiple reflection between the output mirror and the total reflection mirror, and the mode is selected by the aperture while being cut off in a short period by the operation of the Q switch, and the output mirror is Then, the laser beam Lb is emitted.

As the laser oscillation unit 204, a gas laser system using a gas such as CO ₂ , helium-neon, argon, or nitrogen as a medium may be employed. For example, when a carbon dioxide laser is used, the laser oscillation unit 204 is filled with carbon dioxide (CO ₂ ) inside the laser oscillation unit 204 including the built-in electrode, and the carbon dioxide gas is produced by the built-in electrode based on a print signal given from the controller 2. Is excited to cause laser oscillation.

  The laser beam scanning system 220 includes a beam expander 242 that incorporates a Z-axis scanner whose optical path coincides with the laser oscillation unit 204, an X-axis scanner 224, and a Y-axis scanner 226 that is arranged to be orthogonal to the X-axis scanner 224. With. The laser beam scanning system 220 causes the X-axis scanner 224 and the Y-axis scanner 226 to scan the laser beam Lb emitted from the laser oscillation unit 204 two-dimensionally in the work area on the surface of the workpiece W.

  The X-axis scanner 224 and the Y-axis scanner 226 are galvano motors 224b for rotating with galvano mirrors 224a, 226a, galvano mirrors 224a, 226a, which are total reflection mirrors, as reflecting surfaces that reflect light. 226b, and a position detection unit that detects the rotation position of the rotation shaft and outputs it as a position signal, for example, an encoder. The X-axis scanner 224 and the Y-axis scanner 226 are connected to the scanner drive circuit 228. The scanner driving circuit 228 is connected to the controller 2 and drives the X-axis scanner 224 and the Y-axis scanner 226 based on a control signal supplied from the controller 2.

  The beam expander 242 adjusts the spot diameter of the laser beam Lb emitted from the laser medium 206. By adjusting the spot diameter, the working distance (focal length) can be adjusted. That is, by changing the relative distance between the entrance lens and the exit lens by the beam expander 242, the beam diameter of the laser beam Lb can be enlarged / reduced, and the focal position can be changed.

  By controlling the operations of the beam expander 242, the X-axis scanner 224, and the Y-axis scanner 226, the laser beam Lb can be scanned two-dimensionally on the surface of the workpiece W while adjusting the working distance. Therefore, it is possible to print with high accuracy and the minimum spot in a state where the focal length is adjusted with respect to the surface of the workpiece W.

  FIG. 3 is a block diagram showing a configuration when a fiber laser marker is used in the laser marking device 10 to which the linear actuator according to the embodiment of the present invention is applied. As shown in FIG. 3, the laser marking device 10 includes a controller 2 and a marking head 1, and a print data generation device 3 connected to the controller 2 receives an input of a print condition or the like of the workpiece W, and displays The input / output means includes a display unit for displaying a parameter setting screen corresponding to the printing condition.

  The controller 2 is configured as a laser oscillator unit including a main control circuit 508, a workpiece processing information storage unit 510, a power supply circuit 512, an excitation light source 514, and a laser beam amplifier 516, and executes laser oscillation control, laser beam scanning control, and the like. To do. The excitation light source 514 includes a light emitting element such as an LD (laser diode) that generates excitation light for exciting the laser medium, and a condenser lens.

  The laser beam amplifier 516 includes an optical fiber in which a laser medium is added to the core. By amplifying the laser beam using the laser beam amplifier 516, a high-power laser beam with high energy density can be generated. The laser beam amplifier 516 includes a master oscillator unit that generates low-output seed light, a power amplifier unit that amplifies the seed light, a pumping light source device, an isolator, and the like. The master oscillator unit and the power amplifier unit serve as a laser medium. It includes a rare earth-doped optical fiber to which a rare earth element such as ytterbium (Yb) is added.

  The controller 2 and the marking head 1 are connected by an optical fiber cable 520, and the laser beam amplified by the laser beam amplifier 516 is directly input to the optical fiber cable 520.

  The marking head 1 includes an optical isolator 522, a beam expander 524, a beam sampler 526, a shutter 528, a photo interrupter 530, a dichroic mirror 532, a Z axis scanner 534, an X axis / Y axis scanner 536, a power monitor 538, and a guide light source 540. Including.

  The optical isolator 522 constitutes return light suppression means that transmits the laser beam emitted from the end face of the optical fiber cable 520 and suppresses the return light. The optical isolator 522 transmits the laser beam transmitted via the optical fiber cable 520 to the beam expander. Transmission in the forward direction input to 524 is allowed, and transmission in the reverse direction is prohibited. The optical isolator 522 includes, for example, an aperture, a polarizer, and a Faraday rotator. The aperture is a blocking plate for limiting the amount of passing light. The polarizer is a rod-shaped optical element made of a birefringent crystal. A Faraday rotator is a magneto-optical element that rotates a plane of polarization by applying a magnetic field.

  The beam expander 524 constitutes a beam diameter varying unit that variably controls the beam diameter of the laser beam, and is arranged with the optical axis of the optical isolator 522 aligned. The beam expander 524 includes a plurality of lenses arranged on the optical path, and converts the beam diameter to a desired value by adjusting the distance between the lenses. The beam sampler 526 is an optical element that reflects part of the laser beam that has passed through the beam expander 524 toward the dichroic mirror 532 and transmits the other part to the power monitor 538 side.

  The power monitor 538 is a laser power detection sensor that receives the laser beam that has passed through the beam sampler 526 and detects the laser power. The power monitor 538 uses the detection result of the laser power as a power level detection signal to the main control circuit 508 in the controller 2. Output. As the power monitor 538, for example, a thermopile (thermocouple), a photodiode, or the like is used.

  The shutter 528 is a blocking device for blocking the laser beam as necessary, and includes a blocking plate and a drive mechanism that moves the blocking plate. The shutter 528 is disposed between the beam sampler 526 and the dichroic mirror 532.

  The photo interrupter 530 is an optical sensor that optically detects whether or not the shutter 528 is closed. The dichroic mirror 532 is an optical element that reflects only light of a specific wavelength and transmits light of other wavelengths. The dichroic mirror 532 reflects the laser beam that has passed through the shutter 528 toward the Z-axis scanner 534 and emits light from the guide light source 540. The guide light is transmitted as it is.

  The Z-axis scanner 534 is a laser beam scanning mechanism including one or two or more lenses arranged on an optical path and a lens driving motor for moving the lens. By displacing the lens, the marking head 1 The focal position of the laser beam emitted from can be adjusted in the optical axis direction. The Z-axis scanner 534 has a laser beam condensing function. The Z-axis scanner 534 is a scanning mechanism that can move the focal position of the laser beam in the optical axis direction following the height of the workpiece W.

  The X-axis / Y-axis scanner 536 is a laser beam scanning mechanism composed of two galvanometer mirrors arranged on intersecting rotation axes and a galvanometer mirror driving motor for rotating the galvanometer mirror. By rotating the axis, the laser beam is scanned in a direction intersecting the optical axis. Here, the optical axis direction of the laser beam applied to the print target surface is referred to as a Z-axis direction, and two non-parallel directions intersecting the optical axis are referred to as an X-axis direction and a Y-axis direction, respectively.

  The laser beam that has passed through the Z-axis scanner 534 is reflected by the galvanometer mirror of the X-axis / Y-axis scanner 536 and applied to the workpiece W. The guide light source 540 is a light source device that generates guide light for visualizing the irradiation position of the laser beam Lb on the workpiece W. Guide light emitted from the guide light source 540 passes through the dichroic mirror 532 and enters the optical path of the laser beam. The guide light that has entered the optical path of the laser beam is applied to the workpiece W via the Z-axis scanner 534 and the X-axis / Y-axis scanner 536.

  The workpiece machining information storage unit 510 of the controller 2 is a memory that holds information related to laser printing of the workpiece W as workpiece machining information. As workpiece machining information, machining line drawing information when a character or the like is machined on the workpiece W. Laser output control information for controlling laser oscillation is held.

  The main control circuit 508 includes an excitation light source 514, a laser beam amplifier 516, a Z-axis scanner 534, an X-axis / Y-axis scanner 536, and a shutter 528 based on the workpiece machining information held in the workpiece machining information storage unit 510. A control means for controlling, specifically, generating an oscillator control signal for adjusting the peak power and pulse width of the laser beam emitted from the marking head 1 on the basis of the laser output control information; Control signals are output to 514 and the laser beam amplifier 516.

  The main control circuit 508 controls the lens driving motor of the Z-axis scanner 534, the mirror driving motor of the X-axis / Y-axis scanner 536, and the shutter 528 based on the laser output control information and the drawing information. , And various control signals are output to the Z-axis scanner 534, the X-axis / Y-axis scanner 536, and the shutter 528.

  The linear actuator according to the present invention can be applied, for example, as a lens driving motor for the Z-axis scanner 534 of the marking head 1. The linear actuator according to the present invention can also be applied as a mirror driving motor for the X-axis / Y-axis scanner 536 of the marking head 1.

(Embodiment 1)
FIG. 4 is a partially broken plan view of the linear actuator according to Embodiment 1 of the present invention. In FIG. 4, the central portion is broken with the left and right end portions of the upper casing remaining, and the internal structure can be seen. FIG. 5 is a longitudinal sectional view taken along line VV in FIG.

  The linear actuator 600 includes a mover 602, a stator 604, a linear guide (guide device) 606, a position detection device 608, an attachment member 610, and a coupling member 612.

  The mover 602 includes a rectangular cylindrical coil frame (not shown) and a drive coil (not shown) wound around the outer peripheral surface of the coil frame, and each has a central axis direction (vertical direction in FIG. 4). 5 includes an upper horizontal portion 602A, a lower horizontal portion 602B, a left vertical portion 602C, and a right vertical portion 602D having a predetermined width in the vertical direction of the drawing (hereinafter referred to as “front-rear direction”). Here, the central axis means an axis that passes through the center of the mover 602 in the cross section as shown in FIG.

  The upper horizontal portion 602A, the lower horizontal portion 602B, the left vertical portion 602C, and the right vertical portion 602D each have an outer peripheral surface that is a surface facing outward and an inner peripheral surface that faces inward. The stator 604 includes a magnetic body 620 disposed with a predetermined gap from the mover 602. The mover 602 has a rectangular cross section in FIG. 5. However, any shape may be used as long as it has a circular shape or a rectangular shape with a chamfered corner having a predetermined radius, and other cylindrical shapes. You may have such a shape.

  The mover 602 moves in the front-rear direction relative to the stator 604 when an excitation current flows through the drive coil. The absolute position of the stator 604 does not change even when the mover 602 moves.

  The mover 602 has a lens frame 660 (attachment member 610) on the inner peripheral surface of the lower horizontal portion 602B, a light emitting portion 652 of the position detection device 608 on the outer peripheral surface of the upper horizontal portion 602A, and an inner surface of the upper horizontal portion 602A. The light shielding plates 670 are respectively arranged and move in the front-rear direction together with the mover 602. The coupling member 612 also moves in the front-rear direction together with the mover 602. The guide block 644 of the linear guide 606 also moves in the front-rear direction together with the mover 602. This is because the light shielding plate 670 and the lens frame 660 (attachment member 610) move in the front-rear direction together with the mover 602.

  The stator 604 means a portion that does not move in the front-rear direction together with the movable element 602, and includes a magnetic body 620, a fixed plate 640, a guide rail 642 of the linear guide 606, fixed leg portions 632 L and 632 R, and an upper casing 636.

  As shown in FIG. 5, the magnetic body 620 includes a pair of left and right outer yokes 622L and 622R, a pair of left and right permanent magnets 624L and 624R, and a pair of left and right inner yokes 626L and 626R. The outer yokes 622L and 622R are rectangular plate-like members having a constant thickness extending in the front-rear direction, and are made of iron, nickel, cobalt, or other ferromagnetic material. The inner yoke 626L (R) and the outer yoke 622L (R) are provided to collect magnetic lines of force generated from the permanent magnet 624L (R) between the inner yoke 626L (R) and the outer yoke 622L (R). Out of the magnetic bodies, the outer yokes 622L and 622R and the permanent magnets 624L and 624R are disposed outside the mover 602, and the inner yokes 626L and 626R are disposed inside the mover 602.

  A fixed plate 640 is disposed between the inner yokes 626L and 626R, and constitutes a part of the stator 604. Further, a guide rail 642 of the linear guide 606 is attached (fixed) under the fixed plate 640, and the guide rail 642 does not move even when the mover 602 moves.

  The permanent magnets 624L and 624R are rectangular plate-like members attached to the center in the front-rear direction of the outer yokes 622L and 622R, and are magnetized for a long time without receiving a magnetic field or current from the outside, such as ferrite magnets and neodymium magnets. It is comprised with the ferromagnetic material which can hold | maintain. The inner yokes 626L and 626R are plate-like members having a constant thickness extending in the front-rear direction, and are made of iron, nickel, cobalt, and other ferromagnetic materials, like the outer yokes 622L and 622R.

  As shown in FIG. 4, the inner yokes 626L and 626R are disposed so as to pass through the inside of the mover 602, respectively, and the outer yokes 622L and 622L and It is connected to 622R. The connection members 628F and 628R are also preferably made of iron, nickel, cobalt, or other ferromagnetic material.

  The permanent magnets 624L and 624R attached to the outer yokes 622L and 622R are arranged so that the inner surface, which is a surface facing inward, has a predetermined gap from the outer peripheral surface of the mover 602. Here, the outer yoke 622L and the permanent magnet are formed such that the first gap G1 is generated between the outer peripheral surface of the left vertical portion 602C of the mover 602 and the inner surface of the permanent magnet 624L (the surface facing right in FIG. 5). 624L is arranged. Similarly, the outer yoke 622R and the permanent magnet are formed such that the second gap G2 is generated between the outer peripheral surface of the right vertical portion 602D of the mover 602 and the inner surface of the permanent magnet 624R (the surface facing left in FIG. 5). 624R is arranged.

  The inner yokes 626L and 626R are arranged so that the outer surface, which is the surface facing the outer side, has a predetermined gap from the inner peripheral surface of the mover 602. Here, the third gap G3 is formed between the inner peripheral surface (the surface facing right in FIG. 5) of the left vertical portion 602C of the mover 602 and the outer surface (the surface facing left in FIG. 5) of the inner yoke 626L. An inner yoke 626L is arranged to occur. Similarly, a fourth gap G4 is formed between the inner peripheral surface (the surface facing left in FIG. 5) of the right vertical portion 602D of the mover 602 and the outer surface (the surface facing right in FIG. 5) of the inner yoke 626R. An inner yoke 626R is arranged to occur.

  The casing 630 includes fixed leg portions 632L and 632R positioned outside the outer yokes 622L and 622R, and an upper casing 636 positioned above the mover 602 and the stator 604, respectively. The outer yokes 622L and 622R, the permanent magnets 624L and 624R, the inner yokes 626L and 626R, and the connecting members 628F and 628R are integrally attached to the casing 630.

  The outer surfaces of the outer yokes 622L and 622R are connected to the inner surfaces of the fixed leg portions 632L and 632R, which are surfaces facing inward, and fix the stator 604 inside the casing 630. The upper casing 636 is attached to the upper ends of the fixed legs 632L and 632R, and protects the upper surface of the linear actuator 600.

  The stator 604 includes a fixed plate 640 disposed so as to pass through the interior of the mover 602. The fixed plate 640 passes through the inside of the mover 602, extends in the front-rear direction, and is connected to the inner yokes 626L and 626R.

  The linear guide 606 supports the movable element 602 such that the movable element 602 can linearly move in the front-rear direction relative to the stator 604. Specifically, the linear guide 606 is attached (fixed) to the fixed plate 640 and extends in the moving direction of the mover 602, and is attached to the mover 602 along the guide rail 642. And a guide block 644 capable of linear movement by sliding. The guide block 644 is not fixed to the fixed plate 640.

  The position detection device 608 detects a relative position of the mover 602 in the linear movement direction with respect to the stator 604, and various position detection mechanisms can be applied. For example, the position detection device 608 is disposed at a position facing the light emitting unit 652 composed of an LED (Light Emitting Diode) or the like attached to the outer peripheral surface of the upper horizontal portion 602A of the mover 602 and the light emitting unit 652 of the upper casing 636. And a light receiving unit 654 including a PSD (Position Sensitive Detector) or the like. In this case, the light emitting portion 652 on the movable element 602 side and the circuit board (not shown) provided on the stator 604 side are electrically connected by connecting with a flexible cable (not shown). .

  A member to be moved is attached to the attachment member 610. For example, when the lens 662 of the Z-axis scanner 534 (see FIG. 3) in the marking head 1 of the laser marking device 10 is a movement target, the attachment member 610 is a lens frame 660 for holding the lens 662.

  A light shielding plate 670 for blocking light incident on the position detecting device 608 from the inside of the movable element 602 is attached to the inner peripheral surface (the surface facing downward in FIG. 5) of the upper horizontal portion 602A of the movable element 602. ing. The light shielding plate 670 is for preventing light that has passed through a through-hole 672, which will be described later, from reaching the position detection device 608. At least when the light shielding plate 670 moves in accordance with the movement of the movable element 602. Even if it exists, it arrange | positions at the size and position which light-shields between the through-hole 672 and the light-receiving part 654 of the position detection apparatus 608. FIG.

  As shown in FIGS. 6 to 8, the light shielding plate 670 is configured to cover the through hole 672 of the fixed plate 642 in a plan view seen from the upper surface of the movable element 602.

  The coupling member 612 is provided between the position detection device 608 and the attachment member 610, and indirectly connects the upper horizontal portion 602A of the mover 602 to which the position detection device 608 is attached and the lower horizontal portion 602B to which the attachment member 610 is attached. Join. In the first embodiment, the light shielding plate 670 is attached to the inner peripheral surface (the surface facing downward in FIG. 5) of the upper horizontal portion 602A, and the inner peripheral surface (the surface facing upward in FIG. 5) of the lower horizontal portion 602B. The attachment member 610 is attached to the above. Therefore, by attaching the upper end of the coupling member 612 to the light shielding plate 670 and attaching the lower end of the coupling member 612 to the attachment member 610, the position detection device 608 attached to the upper horizontal portion 602A and the lower horizontal portion 602B are attached. The coupling member 612 can be indirectly coupled. The attachment member 610 and the light shielding plate 670 are supported from the inside of the movable element 602 by the coupling member 612, and the rigidity of the vertical method of the movable element 602 is increased.

  The coupling member 612 is disposed between the upper horizontal portion 602A and the lower horizontal portion 602B of the mover 602, supports the lower horizontal portion 602B via the attachment member 610, and supports the upper horizontal portion via the light shielding plate 670. Supports 602A. The coupling member 612 increases the vertical rigidity of the mover 602. By increasing the vertical rigidity, the followability of the movement of the mover is improved with the generation of the driving force, and the response of the linear actuator is improved.

  The coupling member 612 is preferably made of a light material having high rigidity and can be made of, for example, a hard rigid resin material, a cylindrical metal material, or other materials. In the first embodiment, the linear guide 606 is disposed at the center of the movable element 602, and the coupling member 612 is disposed on the outer side in the left-right direction of the linear guide 606.

  The fixing plate 640 has a through hole 672 through which the coupling member 612 can be inserted. The through-hole 672 is formed in a slit shape in the moving direction of the mover 602 so that the coupling member 612 can move as the mover 602 moves. The coupling member 612 can move in the through hole 672 as the mover 602 moves. As shown in FIG. 4, the through hole 672 arranged in the fixed plate 640 is larger than the coupling member 612. As shown in FIG. 5, the coupling member 612 penetrates through the movement of the movable element 602 in the front-rear direction. A gap is provided so that the hole 672 can move in the front-rear direction without contacting the hole 672. Therefore, it is necessary to prevent the light that has passed through the through hole 672 from reaching the position detection device 608 by the light shielding plate 670.

  The light shielding plate 670 is provided between the fixed plate 640 and the upper horizontal portion 602A of the mover 602. The light shielding plate 670 is provided on the inner peripheral surface of the upper horizontal portion 602A. On the opposite side (upward in FIG. 5) across the upper horizontal portion 602A of the light shielding plate 670, a light emitting portion 652 of the position detecting device 608 is provided.

  6 to 8 are schematic diagrams for explaining the operation of the linear actuator according to the first embodiment of the present invention. 6 is a schematic plan view when the mover 602 is located at the center in the linear movement direction, and FIG. 7 is a case where the mover 602 is located at the rearmost part (the light incident side of the lens 662) in the linear movement direction. FIG. 8 is a schematic plan view in the case where the mover 602 is positioned at the foremost part (the light emission side of the lens 662) in the linear movement direction. 6 to 8, the upper side is the light incident side of the lens 662, and the lower side is the light emitting side of the lens 662. 6 to 8 are schematic plan views in a state where the upper casing 636 and the position detection device 608 are removed.

  The vertical direction in FIG. 6, which is the moving direction of the mover 602, is defined as a first direction X, and the left-right direction in FIG. The light shielding plate 670 is attached to the inner peripheral surface of the upper horizontal portion 602A of the mover 602, and extends in the first side 670A, the second side 670B, and the second direction Y parallel to the first direction X. This is a plate-like member having a rectangular shape in plan view and having parallel rear side 670C and front side 670D. The first side side 670A and the second side side 670B of the light shielding plate 670 are located outward from the outer edge in the second direction Y of the through holes 672 and 672, respectively. The rear side 670 </ b> C of the light shielding plate 670 is positioned rearward of the rear end edges of the through holes 672 and 672, and the front side 670 </ b> D is positioned forward of the front end edges of the through holes 672 and 672.

  As shown in FIG. 7, when the mover 602 is moved to the last part in the first direction X, for example, the excitation current flowing in the drive coil (not shown) of the mover 602 is controlled, and the light incident on the lens 662 is controlled. The mover 602 is moved to the side. At this time, the coupling member 612 which is a connecting portion is guided in the through hole 672 and moved rearward, and at the same time, the light shielding plate 670 attached to the inner peripheral surface of the movable element 602 is also moved rearward. As shown in FIG. 7, the front side 670 </ b> D of the light shielding plate 670 is located in front of the front edge portions of the through holes 672 and 672 in a state where the light shielding plate 670 is located at the rearmost part in the first direction X. Yes.

  Next, as shown in FIG. 8, when the mover 602 is moved to the forefront in the first direction X, for example, the excitation current flowing in the drive coil (not shown) of the mover 602 is controlled to control the lens 662. The mover 602 is moved to the light emitting side. At this time, the coupling member 612 which is a connecting portion is guided in the through hole 672 and moved forward, and at the same time, the light shielding plate 670 attached to the inner peripheral surface of the mover 602 is also moved forward. As shown in FIG. 8, the rear side 670 </ b> C of the light shielding plate 670 is located behind the rear edge of the through holes 672 and 672 in the state where the light shielding plate 670 is located at the foremost portion in the first direction X. Yes.

  As shown in FIGS. 6 to 8, the light shielding plate 670 covers the through hole 672 of the fixed plate 640 between the fixed plate 640 and the position detecting device 608 and viewed from above the movable element 602. .

  As described above, according to the first embodiment, the rigidity in the vertical direction of the mover 602 is enhanced by the coupling member 612. That is, since the coupling member 612 that supports the lens frame 660 (mounting member 610) that moves back and forth together with the movable element 602 and the position detection device 608 functions like a support bar, the movable element 602 moves up and down. It becomes difficult to deform in the direction. The coupling member 612 supports the inner peripheral surface of the upper horizontal portion 602A of the mover 602 from the inside to the outside via the light shielding plate 670, and the lower horizontal portion 602B of the mover 602 via the lens frame 660 (mounting member 610). Since the inner peripheral surface of the movable member 602 is supported from the inner side to the outer side and the movable member 602 is supported in the vertical direction, the rigidity of the movable member 602 is increased and the movable member 602 is not easily deformed in the vertical direction.

  Further, a coupling member 612 supports the upper surface of the lens frame 660 (attachment member 610) and the light emitting unit 652 of the position detection device 608. This portion is a portion that has not been used in the mover 602, and the rigidity of the mover 602 can be increased while effectively utilizing the space.

 By increasing the rigidity of the mover 602, the responsiveness is enhanced, and even a linear motor that requires fine control can be controlled with high accuracy.

 In the first embodiment, the light shielding plate 670 is disposed on the inner peripheral surface of the lower horizontal portion 602B of the movable element 602. However, when the light shielding is not necessary, the light shielding plate 670 is not necessary. The case where there is no need to block light means that the member attached to the attachment member 610 does not transmit light, the case where the amount of light is within the allowable range even when the light reaches the position detection device 608, or the allowable structure In the case where the position detection device 608 has the above.

 Further, the mounting member 610 (lens frame 660) is disposed inside the movable element 602, but is not particularly limited thereto. For example, in the example of FIG. 5, the lower horizontal portion 602B of the movable element 602 is provided. It may be arranged on the outer surface of the. As shown in FIG. 5, the space inside the movable element 602 can be effectively utilized when the inner part is disposed.

  As described above, according to the first embodiment, even if the mover 602 moves to the maximum in the first direction X, the through holes 672 and 672 are not exposed upward by the light shielding plate 670. Therefore, even when the optical position detection device 608 is attached to the upper horizontal portion 602A side of the mover 602, the light from the attachment member 610 side is blocked by the light shielding plate 670, and the position detection device 608 side is disturbed. The light can not reach. Thereby, erroneous detection of the position detection device 608 can be prevented, and the positioning accuracy of the linear actuator 600 can be maintained high.

  In particular, when adjusting the focal position of the high-power laser in the linear actuator 600, the position detection is performed even when a small amount of light is incident on the position detection device 608 because the light incident on the lens has a high output. Adversely affect. Therefore, it is highly necessary to reliably prevent light from entering with the light shielding plate 670.

(Embodiment 2)
Since the basic configuration of the linear actuator according to the second embodiment of the present invention is the same as that of the first embodiment, detailed description thereof will be omitted by attaching the same reference numerals. The second embodiment is different from the first embodiment in that one coupling member is provided in order to maintain the rigidity of the movable element 602 in the opposing direction of the upper horizontal portion 602A and the lower horizontal portion 602B.

  FIG. 9 is an explanatory diagram of the linear actuator according to the second embodiment of the present invention, and FIG. 10 is a longitudinal sectional view taken along line XX of FIG. FIG. 9 shows a state in which the upper casing and the position detection device are removed, and the same members as those in the first embodiment are denoted by the same reference numerals.

  In the second embodiment, only one coupling member 680 is provided in the center portion in the second direction Y, and the lens frame 660 (attachment member 610) and the light shielding plate 670 are coupled to each other, thereby moving the movable element 602. The upper horizontal portion 602A and the lower horizontal portion 602B facing each other are indirectly coupled. Thereby, the mover 602 has increased rigidity in the facing direction of the upper horizontal portion 602A and the lower horizontal portion 602B, and can suppress deformation and damage.

  The stator 604 includes a fixed plate 682 arranged so as to pass through the inside of the movable element 602. The fixed plate 682 passes through the inside of the movable element 602, extends in the front-rear direction, and is connected to the inner yokes 626L, 626R, or the casing 630. The fixing plate 682 has a through hole 684 through which the coupling member 680 can be inserted. The through hole 684 is formed in a slit shape in the moving direction of the movable element 602 so that the coupling member 680 can be moved with the movement of the movable element 602.

  In the second embodiment, since the coupling member 680 is provided at the center in the second direction Y, the linear guide 606 similar to that of the first embodiment cannot be attached. Therefore, as shown in FIG. 10, a linear guide rail having a guide rail 686A extending in the moving direction of the mover 602 and a guide block 686B that can move linearly by sliding along the guide rail 686A. A guide 686 is provided at a position eccentric from the coupling member 680.

  By attaching the guide rail 686A to the fixed plate 682 and attaching the guide block 686B to the lens frame 660 (attachment member 610), the mover 602 can move in parallel with the second direction Y in FIG. The linear guide 686 can be provided with only one set of the guide rail 686A and the guide block 686B, and one of the linear guides 686 can be omitted.

  As described above, according to the second embodiment, even if the number of coupling members 680 is not two as in the first embodiment, the movable element 602 can be supported by one coupling member 680. .

(Embodiment 3)
Since the basic configuration of the linear actuator according to the third embodiment of the present invention is the same as that of the first embodiment, detailed description thereof will be omitted by assigning the same reference numerals. The third embodiment is implemented in that three coupling members are provided in parallel in the second direction Y in order to maintain the rigidity in the opposing direction of the upper horizontal portion 602A and the lower horizontal portion 602B of the mover 602. This is different from Form 1.

  FIG. 11 is an explanatory diagram of the linear actuator according to the third embodiment of the present invention, and shows a plan view in a state where the upper casing and the position detection device are removed. In FIG. 11, the same members as those in the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 11, in the third embodiment, three coupling members 690A, 690B, and 690C are provided in parallel in the second direction Y. The coupling members 690A, 690B, and 690C respectively couple the lens frame 660 (mounting member 610) and the light shielding plate 670, and indirectly couple the upper horizontal portion 602A and the lower horizontal portion 602B facing each other of the movable element 602. ing.

  The stator 604 includes a fixed plate 694 disposed so as to pass through the inside of the movable element 602. The fixed plate 694 passes through the inside of the mover 602, extends in the front-rear direction, and is connected to the inner yokes 626L, 626R, or the casing 630. The fixing plate 694 has through holes 692A, 692B, and 692C through which the coupling members 690A, 690B, and 690C can be inserted. The through holes 692A, 692B, and 692C are formed in a slit shape in the moving direction of the mover 602 so that the coupling members 690A, 690B, and 690C can move as the mover 602 moves.

  In the third embodiment, the three coupling members 690A, 690B, and 690C are guided by the through holes 692A, 692B, and 692C of the fixed plate 694, respectively, and can move in the moving direction of the mover 602. When the fitting state between the coupling members 690A, 690B, and 690C and the through holes 692A, 692B, and 692C is in close contact, the linear guide 606 of the first embodiment can be omitted. Further, since the lens frame 660 (mounting member 610) and the light shielding plate 670 are coupled using the three coupling members 690A, 690B, and 690C, the upper horizontal portion 602A and the lower horizontal portion 602B of the mover 602 are coupled. It is possible to further increase the rigidity in the facing direction.

(Embodiment 4)
Since the basic configuration of the linear actuator according to the fourth embodiment of the present invention is the same as that of the first embodiment, detailed description thereof will be omitted by attaching the same reference numerals. In the fourth embodiment, in order to maintain the rigidity in the opposing direction of the upper horizontal portion 602A and the lower horizontal portion 602B of the mover 602, two coupling members are arranged in parallel in the first direction X and the second direction Y, respectively. This is different from the first embodiment.

  FIG. 12 is an explanatory diagram of the linear actuator according to the fourth embodiment of the present invention, and shows a plan view in a state where the upper casing and the position detection device are removed. In FIG. 12, the same members as those in the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 12, in the fourth embodiment, two coupling members 700A, 700B, 700C, and 700D are provided in parallel in each of the first direction X and the second direction Y. The coupling members 700A, 700B, 700C, and 700D respectively couple the lens frame 660 (mounting member 610) and the light shielding plate 670, and indirectly connect the upper horizontal portion 602A and the lower horizontal portion 602B facing the movable element 602. Are connected.

  The stator 604 includes a fixed plate 702 disposed so as to pass through the interior of the mover 602. The fixed plate 702 passes through the inside of the movable element 602, extends in the front-rear direction, and is connected to the inner yokes 626L, 626R, or the casing 630.

  The fixing plate 702 has through holes 704A, 704B, 704C, and 704D through which the coupling members 700A, 700B, 700C, and 700D can be inserted. The through holes 704A, 704B, 704C, and 704D are formed in a slit shape in the moving direction of the mover 602 so that the coupling members 700A, 700B, 700C, and 700D can move as the mover 602 moves. Yes.

  In the fourth embodiment, the four coupling members 700A, 700B, 700C, and 700D are guided by the through holes 704A, 704B, 704C, and 704D of the fixed plate 702, respectively, and can move in the moving direction of the mover 602. ing.

  In the fourth embodiment, the linear guide 606 in the first embodiment can be provided, and the fitting state of the coupling members 700A, 700B, 700C, 700D and the through holes 704A, 704B, 704C, 704D is in close contact. In some cases, the linear guide 606 can also be omitted. In addition, since the lens frame 660 (the mounting member 610) and the light shielding plate 670 are coupled using the four coupling members 700A, 700B, 700C, and 700D, the upper horizontal portion 602A and the lower horizontal portion of the mover 602 are combined. It is possible to further increase the rigidity in the facing direction of 602B.

(Embodiment 5)
Since the basic configuration of the linear actuator according to the fifth embodiment of the present invention is the same as that of the first embodiment, detailed description thereof will be omitted by attaching the same reference numerals. The fifth embodiment is different from the first embodiment in that a plate-like member is used as a coupling member in order to maintain the rigidity of the movable element 602 in the opposing direction of the upper horizontal portion 602A and the lower horizontal portion 602B. To do.

  FIG. 13 is an explanatory diagram of the linear actuator according to the fifth embodiment of the present invention, and shows a plan view in a state where the upper casing and the position detection device are removed. In FIG. 13, the same members as those in the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 13, in the fifth embodiment, plate-like members are used as the coupling members 710A and 710B, and the through holes 714A and 714B provided in the fixed plate 712 correspond to the thickness of the coupling members 710A and 710B. The slit shape is wide.

  By doing in this way, the linear mobility in case the needle | mover 602 moves becomes favorable, and the play of the needle | mover 602 in the left-right direction can be suppressed. In addition, a low-cost sheet metal member can be used.

  Of course, in the sense of obtaining the same effect, a prismatic shape made of metal instead of a plate shape may be used. FIG. 14 is an explanatory diagram of another configuration of the linear actuator according to the fifth embodiment of the present invention.

  As shown in FIG. 14, prismatic columns are used as the coupling members 720A and 720B, and the through holes 724A and 724B provided in the fixing plate 722 are formed in a slit shape having a width corresponding to the width of the coupling members 720A and 720B. .

  In the example of FIG. 14, since the lens frame 660 (mounting member 610) and the light shielding plate 670 are coupled by the coupling members 720A and 720B, the opposing direction of the upper horizontal portion 602A and the lower horizontal portion 602B of the mover 602 Further, the rigidity of the movable member 602 can be further increased, and rattling in the left-right direction when the mover 602 moves can be suppressed.

  As described above, according to the first to fifth embodiments, the rigidity of the mover in the linear actuator can be increased, the position detection accuracy by the position detection device and the positioning accuracy of the mover can be increased. It becomes possible to suppress malfunction and failure due to deformation and damage.

  The present invention is not limited to the above-described embodiments, and various changes and improvements can be made within the scope of the present invention. For example, other position detection mechanisms can be used as the position detection device 608.

  Specifically, a reflective photoelectric linear scale can be used. In this case, a scale having a scale in the moving direction of the mover 602 is attached to the outer peripheral surface of the upper horizontal portion 602A of the mover 602. In addition, a light projecting / receiving device that performs light projecting / receiving on the scale is provided on the inner peripheral surface of the upper casing 636 facing the scale. Further, an encoder that converts an output signal from the light projecting / receiving device into movement distance information of the mover 602 is provided. In addition, a transmissive photoelectric linear scale or an electromagnetic induction linear scale can be used.

  Further, the light shielding plate 670 and the stator 604 may be connected in a shape that fits each other. FIG. 15 is a partial schematic cross-sectional view showing a coupled state of light shielding plate 670 and stator 604 of linear actuator 600 according to the embodiment of the present invention.

  In FIG. 15A, the light shielding plate 670 has a flat plate shape, whereas the cross-sectional shape of the stator 604 is U-shaped at both ends so that the end of the light shielding plate 670 is sandwiched from above and below. Is formed. Thereby, the possibility that irregularly reflected light leaks is also reduced.

  Further, as shown in FIG. 15B, the light shielding plate 670 may be formed so that the cross-sectional shape is a U-shape. In this case, the stator 604 may be provided with a protrusion capable of fitting both ends of the light shielding plate 670 together. Thereby, like FIG. 15A, the possibility that the irregularly reflected light leaks is reduced.

DESCRIPTION OF SYMBOLS 1 Marking head 2 Controller 3 Print data generation apparatus 4 External apparatus 10 Laser marking apparatus 600 Linear actuator 602 Movable element 602A Upper horizontal part 602B Lower horizontal part 602C Left vertical part 602D Right vertical part 604 Stator 606,686 Linear guide (Guide device) )
608 Position detection device 610 Mounting member 612, 680, 690A, 690B, 690C, 700A, 700B, 700C, 700D, 710A, 710B, 720A, 720B Coupling member 620 Magnetic body 640, 682, 694, 702, 712, 722 Fixing plate 642, 686A Guide rail 644, 686B Guide block 660 Lens frame 662 Lens 670 Shading plate 672, 684, 692A, 692B, 692C, 704A, 704B, 704C, 704D, 714A, 714B, 724A, 724B Through-hole

Claims (10)

A movable part having a cylindrical mover around which a drive coil is wound in the circumferential direction of the outer peripheral surface;
A stator having a magnetic body disposed outside the movable element with a predetermined gap from an outer peripheral surface of the movable element, and a stationary plate disposed so as to pass through the interior of the movable element;
A guide rail disposed inside the mover and attached to the fixed plate and extending in a moving direction of the mover; and a guide block attached to the mover and linearly movable along the guide rail. A linear guide having,
A position detection device that is disposed on an outer peripheral surface or an inner peripheral surface of the mover and detects a relative position in a linear movement direction of the mover with respect to the stator;
A position perpendicular to the linear movement direction of the mover is attached to an outer peripheral surface or an inner peripheral surface of the mover at a position opposite to the position where the position detection device is disposed across the center of the mover. An attachment member to which a member to be moved is attached together with the mover;
The mover is arranged inside the mover, and supports the mover in the direction in which the position detection device is arranged and the direction in which the mounting member is arranged from the inside of the mover, and the position detection device. A coupling member for coupling the movable part between the mounting member and
The linear plate, wherein the fixed plate has a through hole having a slit shape in a moving direction of the mover, and the coupling member is inserted into the through hole. The position detection device is an optical position detection device,
2. The linear actuator according to claim 1, further comprising: a light shielding plate that blocks light passing through the through hole toward the position detection device on an inner peripheral surface side of the mover. The position detection device is an optical position detection device,
2. The light shielding plate according to claim 1, further comprising: a light shielding plate that covers the through hole of the fixed plate between the fixed plate and the position detection device as viewed from above the movable element. Linear actuator.   The linear actuator according to claim 2, wherein the light shielding plate is disposed in contact with an inner peripheral surface of the mover.   5. The linear actuator according to claim 1, wherein the position detection device and the mounting member are disposed at positions facing each other with the linear guide interposed therebetween. The stator has a plurality of inner yokes,
The linear actuator according to claim 1, wherein the fixing plate fixes between the plurality of inner yokes, and the through hole is disposed between the plurality of inner yokes. . The linear guide is disposed on the upper surface of the mounting member,
A plurality of support members are arranged on the left and right sides of the linear guide so as to contact the linear guide,
The linear actuator according to claim 1, wherein the fixed plate is disposed on an upper surface of the linear guide. The position detection device has a light emitting unit and a light receiving unit,
8. The linear actuator according to claim 1, wherein one of the light emitting unit and the light receiving unit is disposed on the movable element, and the other is disposed on the stator. 9. The mover has a rectangular cylindrical shape, and has a top surface, a bottom surface, a left surface, and a right surface in a cross-sectional view in a plane perpendicular to the linear movement direction of the mover,
The stator is
A plurality of inner yokes arranged with gaps between the left surface and the right surface inside the mover and connected by the fixed plate;
A plurality of inner yokes, and a plurality of outer yokes connected to ends of the mover in a linear movement direction, respectively, with a gap between the left surface and the right surface outside the mover;
The position detection device is disposed on the outer peripheral surface of the upper surface of the mover,
The light shielding plate is disposed on the inner peripheral surface of the upper surface of the mover,
The mounting member is disposed on the inner peripheral surface of the lower surface of the mover,
The linear guide is disposed on the upper surface of the mounting member,
The said coupling member has penetrated the through-hole of the said fixed plate, and has couple | bonded the upper surface of the said attachment member, and the lower surface of the said light-shielding plate. The linear actuator described.   10. The linear actuator according to claim 1, wherein the attachment member is a lens frame that can accommodate a lens that performs focus adjustment of laser light.

Images