JP2009171663A - Linear motor and component transfer apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the thickness of a linear motor in a thickness direction perpendicular to both a width direction and a moving direction, in the linear motor for moving a movable portion in the moving direction by an interaction of magnetic fluxes generated in both a stator provided on a base plate and a mover provided on the movable portion while allowing the stator and the mover to oppose to each other in the width direction and a component transfer apparatus using the linear motor. <P>SOLUTION: The mover (yoke 5+permanent magnet 6), the armature (stator) 3 and a return spring (biasing member) 15 are arranged in a width direction Y. With this configuration, the linear motor LM is reduced in thickness, compared to a linear motor in which a biasing member (coil spring) is arranged at a position deviated from a direction where the mover and the stator are arranged. In addition, since the return spring 15 has a height Hs in a thickness direction X set at lower than the height Hm of a motor body, the linear motor LM is prevented from an increase in thickness due to the return spring 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a linear motor that linearly moves a movable base with respect to a base plate, and a component transfer apparatus that uses the linear motor.

  The linear motor has a primary side element in which a plurality of coils are arranged in a magnetic core, and a secondary side element in which a plurality of permanent magnets are arranged in a yoke formed of a ferromagnetic material. Permanent magnets are spaced apart while facing the coil. Then, by moving the magnetic field of the magnetic pole core by controlling the drive current applied to the coil, the primary side element (or the secondary side element) is relative to the secondary side element (or the primary side element). Moving. As such a linear motor, for example, as described in Patent Document 1, while a traveling rail is provided on the mover side, a support sliding member (slider) is provided on the stator side, and the mover is fixed to the stator. Some of them move up and down. That is, in this linear motor, three ferromagnetic plate-like yokes (for example, made of SS400) are combined to form an assembly having a U-shaped cross section along the vertical direction. The permanent magnets are provided in rows in the vertical direction on the inner surfaces of the opposing yokes to form a magnetic circuit, while a traveling rail extends in the vertical direction with respect to the outer surface of the yoke. Thus, the mover is constituted by the yoke and the permanent magnet. A support sliding member (slider) is slidably provided along the traveling rail, and a stator is attached to the support sliding member. The stator is provided with a multiphase coil so as to face the magnetic pole of the magnetic circuit of the mover and be separated from the surface of the magnetic pole by a predetermined distance. For this reason, by controlling the drive current applied to the coil as described above, the mover moves relative to the stator. Further, one end of a coil spring is connected to the mover, and the mover is urged upward by the coil spring to support its own weight.

Japanese Unexamined Patent Publication No. 2007-74832 (FIGS. 1, 3, and 4)

  By the way, the applications of linear motors have been increasing year by year mainly in parts transfer equipment for handling parts such as electronic parts, manufacturing equipment for manufacturing semiconductor devices, liquid crystal display devices, etc. There is a growing need for high-performance linear motors that have high responsiveness. However, in the linear motor, three yokes are arranged in a substantially U-shape, and an arrangement of permanent magnet-coil-permanent magnet is formed between two opposing yokes. Further, the arrangement position of the coil spring is set only from the viewpoint of simply exchanging the coil spring without considering the arrangement relationship between the mover and the stator. For these reasons, the conventional linear motor is thick in the direction orthogonal to the moving direction.

  The present invention has been made in view of the above problems, and moves the movable part by the interaction of magnetic flux generated between the stator provided on the base plate and the movable element provided on the movable part in the width direction. In a linear motor that moves in a direction, the first object is to reduce the thickness in the thickness direction perpendicular to both the width direction and the moving direction.

  Moreover, this invention makes it the 2nd objective to provide the components transfer apparatus using the said linear motor.

  In order to achieve the first object, a linear motor according to the present invention has a base plate, a movable portion that is movable in a predetermined movement direction with respect to a base surface of the base plate, and a movement direction with respect to the movable portion. A movable element extending in the movement direction with respect to the base surface of the base plate so as to face the movable element in the width direction orthogonal to the movement direction and spaced from the movable element, and the movable part and the stator. And a biasing member that is disposed in the width direction and biases the movable portion toward one side in the moving direction, and has a driving force larger than the biasing force of the biasing member due to the interaction of magnetic flux generated by the mover and the stator. And the movable part is driven in the movement direction.

  In the invention configured as described above, the movable portion is urged to one side in the moving direction by the urging member, and is located on one side in the moving direction while no driving force is generated. On the other hand, when a driving force is generated by the interaction of magnetic fluxes generated by the mover and the stator, the movable part is driven to one side in the moving direction or driven to the other side in the moving direction against the urging force. . In order to generate the force (electromagnetic force and elastic force) for moving the movable part in the moving direction as described above, the mover, the stator and the urging member are provided. The stator and the biasing member are arranged along the width direction. For this reason, compared with the linear motor which has arrange | positioned the urging member (coil spring) in the position remove | deviated from the arrangement | positioning direction of a needle | mover and a stator as described in patent document 1, it concerns on this invention which has the said arrangement structure. In the linear motor, the linear motor becomes smaller in the thickness direction perpendicular to both the width direction and the moving direction, and the linear motor can be made thinner.

  A component transfer device according to the present invention is a component transfer device that transfers a component from a component storage portion to a component mounting region. To achieve the second object, a base member and a base member are provided. A nozzle shaft that is supported so as to be movable in the vertical direction, has a suction nozzle attached to the tip, and applies a negative pressure supplied to the suction nozzle via a negative pressure pipe connected to the rear end, and a nozzle shaft And a vertical drive mechanism for driving the vertical movement mechanism, and a head drive means for moving the head unit between an upper position of the component housing portion and an upper position of the component mounting area. The linear motor according to any one of claims 1 to 8, wherein the linear motor has a moving direction parallel to the vertical direction, and the urging member urges the movable part upward. Attached to over the scan element, the movable part of the linear motor is characterized in that it is connected to the nozzle shaft.

  In the component transfer apparatus configured as described above, the movable portion of the linear motor is connected to the nozzle shaft and the movable portion is driven to drive the nozzle shaft in the vertical direction. Thus, the size of the component transfer device can be reduced by reducing the thickness of the linear motor.

  The present invention relates to a linear motor and a component transfer apparatus using the linear motor. In the following, after describing a schematic configuration of a surface mounter which is an embodiment of a component transfer apparatus, the configuration of the linear motor is described. The operation and the like will be described in detail.

  FIG. 1 is a plan view showing a schematic configuration of a surface mounter as an embodiment of a component transfer apparatus according to the present invention. FIG. 2 is a front view and a side view of the head unit. FIG. 3 is a block diagram showing an electrical configuration of the surface mounter shown in FIG. In these drawings and drawings to be described later, a three-dimensional coordinate system corresponding to the moving direction Z, the width direction Y, and the thickness direction X of the linear motor according to the present invention is adopted.

  In the surface mounter MT, the substrate transport mechanism 102 is disposed on the base 111 so that the substrate 103 can be transported in a predetermined transport direction X. More specifically, the substrate transport mechanism 102 has a pair of conveyors 121 and 121 that transport the substrate 103 from the right side to the left side of FIG. These conveyors 121 and 121 are controlled by a drive control unit 141 of a control unit 104 that controls the entire surface mounter MT. That is, the conveyors 121 and 121 operate according to a drive command from the drive control unit 141, and stop the board 103 that has been carried in at a predetermined mounting work position (the position of the board 103 shown in the figure). The substrate 103 thus transported is fixed and held by a holding device (not shown). An electronic component (not shown) supplied from the component storage unit 105 is transferred to the substrate 103 by a suction nozzle 161 mounted on the head unit 106. When the mounting process is completed for all components to be mounted on the substrate 103, the substrate transport mechanism 102 carries out the substrate 103 in accordance with a drive command from the drive control unit 141.

  On both sides of the substrate transport mechanism 102, the component housing portions 105 are arranged. These component housing parts 105 include a number of tape feeders 151. In addition, each tape feeder 151 is provided with a reel (not shown) around which a tape storing and holding electronic components is wound, so that the electronic components can be supplied. That is, each tape stores and holds small chip electronic components such as an integrated circuit (IC), a transistor, a resistor, and a capacitor at predetermined intervals. The tape feeder 151 feeds the tape from the reel toward the head unit 106, so that the electronic components in the tape are intermittently fed out. As a result, the electronic components can be picked up by the suction nozzle 161 of the head unit 106. .

  In this embodiment, in addition to the substrate transport mechanism 102, a head drive mechanism 107 is provided. The head drive mechanism 107 is a mechanism for moving the head unit 106 in the X direction and the Y axis direction (direction orthogonal to the X axis and Z direction) over a predetermined range of the base 111. Then, the electronic component sucked by the suction nozzle 161 by the movement of the head unit 106 is transported from the position above the component housing portion 105 to the position above the substrate 103. That is, the head drive mechanism 107 has a mounting head support member 171 extending in the X direction, and the mounting head support member 171 supports the head unit 106 so as to be movable along the X axis. Further, both ends of the mounting head support member 171 are supported by a fixed rail 172 in the Y-axis direction, and are movable along the fixed rail 172 in the Y-axis direction. Further, the head drive mechanism 107 includes an X-axis servo motor 173 that is a drive source for driving the head unit 106 in the X direction, and a Y-axis servo motor 174 that is a drive source for driving the head unit 106 in the Y-axis direction. Yes. The motor 173 is connected to the ball screw 175, and the head unit 106 is driven in the X direction via the ball screw 175 when the motor 173 operates according to an operation command from the drive control unit 141. On the other hand, the motor 174 is connected to the ball screw 176, and the mounting head support member 171 is driven in the Y-axis direction via the ball screw 176 by operating the motor 174 in accordance with an operation command from the drive control unit 141. Is done.

  The head drive mechanism 107 causes the head unit 106 to transport the electronic component to the substrate 103 while being sucked and held by the suction nozzle 161 and to transfer it to a predetermined position (component transfer operation). More specifically, the head unit 106 is configured as follows. In the head unit 106, ten mounting heads extending in the vertical direction Z are arranged in a row at equal intervals in the X direction (the conveyance direction of the substrate 103 by the substrate conveyance mechanism 102). A suction nozzle 161 is attached to each tip of the mounting head. That is, as shown in FIG. 2, each mounting head includes a nozzle shaft 163 extending in the Z direction. An air passage extending upward (Z direction) is formed in the axial center portion of the nozzle shaft 163. The suction nozzle 161 is connected to the lower end of the nozzle shaft 163 and communicates with the air passage. On the other hand, the upper end is open and connected to a vacuum suction source and a positive pressure source via a connecting portion 164, a connecting member 165, an air pipe 166 and a vacuum switching valve mechanism 167.

  Further, the head unit 106 is provided with a vertical drive mechanism 168 that moves the nozzle shaft 163 up and down in the vertical direction Z. The motor controller 142 of the drive control unit 141 controls the vertical drive mechanism 168 to move the nozzle shaft 163 up and down. The suction nozzle 161 is moved up and down in the direction Z, thereby moving the suction nozzle 161 in the up and down direction Z and positioning. In this embodiment, a multi-axis linear motor MLM in which ten single-axis linear motors LM1 to LM10 are combined is used as the vertical drive mechanism 168. Details of this configuration will be described later.

  Further, an R-axis servo motor 169 that rotates the suction nozzle 161 in the R direction is provided, and the R-axis servo motor 169 is operated based on an operation command from the drive control unit 141 of the control unit 104 to make the suction nozzle 161 R Rotate in the direction. Therefore, the head unit 106 is moved to the component storage unit 105 by the head drive mechanism 107 as described above, and the electrons supplied from the component storage unit 105 are driven by driving the vertical drive mechanism 168 and the R-axis servo motor 169. The tip of the suction nozzle 161 comes into contact with the component in an appropriate posture.

  FIG. 4 is a diagram showing the configuration of the vertical drive mechanism. In this embodiment, the multi-axis linear motor MLM used as the vertical drive mechanism 168 is composed of ten single-axis linear motors LM1 to LM10 and two side plates SPa and SPb as shown in FIG. . Each of the single-axis linear motors LM1 to LM10 has a movable element extending in the movement direction Z with respect to the movable base 4 movable in a predetermined movement direction Z on the base plate 1 and a width direction orthogonal to the movement direction Z. The stator extends in the movement direction Z with respect to the base plate 1 so as to face Y apart from the mover, and the movable base 4 is driven in the movement direction Z by the interaction of the magnetic flux generated in the mover and the stator. To do. These single-axis linear motors LM1 to LM10 are stacked in the X direction. The configuration and operation of the linear motors LM1 to LM10 and the laminated structure of the linear motor will be described in detail later.

  Further, a side plate SPa is disposed on the (−X) side of the linear motor LM1, while a side plate SPb is disposed on the (+ X) side of the linear motor LM10. The shaft linear motors LM1 to LM10 are sandwiched. Three fastening through holes are formed at preset positions in each of the side plates SPa and SPb and the single-axis linear motors LM1 to LM10, and bolts 13p to 13p are formed so as to penetrate these fastening through holes. 13q is inserted and fastened by a nut, and the side plate SPa, single-axis linear motors LM1 to LM10, and side plate SPb are integrated to form a multi-axis linear motor MLM. The multi-axis linear motor MLM is attached to the base plate 160 of the head unit 106 as shown in FIG. The side plate SPb also functions as a cover that covers the concave portion 1e (see FIG. 7) of the linear motor LM10 at the end.

  Further, a nozzle shaft 163 is connected to the movable base 4 of each of the linear motors LM1 to LM10 via a connecting portion 164. Each connecting portion 164 includes an L-shaped block member 164a and a shaft holder 164b as shown in FIG. Each block member 164a is screwed to the movable base 4 with a screw by an end extending in the (+ Z) direction. Accordingly, the block member 164a is coupled to the lower end portion of the movable base 4, that is, the (−Z) side end portion by each of the linear motors LM1 to LM10. Further, the shaft holder 164b is attached to the lower surface of the end portion extending in the (−Y) direction of each block member 164a, and the nozzle shaft 163 can be held on the lower surface side of the shaft holder 164b, that is, the (−Z) direction side. Yes. A connecting member 165 is attached to the side surface of the (−Y) side end of the shaft holder 164b. One end of an air pipe 166 is connected to the connecting member 165, and air sent from the vacuum switching valve mechanism 167 is sent to the shaft holder 164b via the air pipe 166, or conversely from the shaft holder 164b. Air can be sucked into the vacuum switching valve mechanism 167 via the air pipe 166. In this way, the vacuum switching valve mechanism 167 and the suction nozzle 161 are connected by the air path (not shown) in the air pipe 166-shaft holder 164b and the nozzle shaft 163, and a positive pressure is supplied to each suction nozzle 161. Conversely, negative pressure can be supplied to each suction nozzle 161.

  In this embodiment, the multi-axis linear motor MLM is used as the vertical drive mechanism 168, and the moving direction of each movable base 4 is parallel to the vertical direction Z. For this reason, a vertical load is always applied to each movable base 4. Therefore, in each of the linear motors LM1 to LM10, the upper end portion of the return spring 15 is engaged with the spring engaging portion 1h of the base plate 1, and the lower end portion is provided at the (−Y) side end portion of the block member 164a. The movable base 4 is urged upward by the return spring 15, that is, in the (+ Z) direction side. As a result, the movable base 4 is housed in the base plate 1 while the current supply to the coils 3c of the linear motors LM1 to LM10 (FIGS. 5 and 6 to be described later) is stopped. As a result, each suction nozzle 161 is positioned above, and even if the X-axis servo motor 173 and the Y-axis servo motor 174 are operated in a state where the vertical drive mechanism 168 does not function due to the current stop, for example, each suction nozzle 161 Or, the adsorbed electronic component does not cause an interference accident with the substrate 103, the conveyor 121, or the like. Thus, the return spring 15 functions as the “biasing member” of the present invention.

  In the surface mounter configured as described above, the main control unit 143 of the control unit 104 controls each part of the apparatus in accordance with a program stored in advance in a memory (not shown) of the control unit 104 so that the head unit 106 is moved to the component housing unit. A reciprocal movement is performed between the upper position of 105 and the upper position of the substrate 103. In addition, the head unit 106 is driven and controlled by the vertical drive mechanism 168 and the R-axis servo motor 169 in a state where the head unit 106 is stopped at an upper position of the component storage unit 105, and the suction nozzle 161 is attached to the electronic component supplied from the component storage unit 105. The tip part is brought into contact with a proper posture, and a negative pressure suction force is applied to the suction nozzle 161, thereby holding the component by the suction nozzle 161. Then, the head unit 106 moves to a position above the substrate 103 while holding the components by suction, and then moves to a predetermined position. In this manner, the component transfer operation of transferring the component from the component storage unit 105 to the component mounting area of the substrate 103 is repeatedly performed.

  Next, the configuration and operation of the linear motor constituting the vertical drive mechanism 168 of the surface mounter MT will be described in detail. FIG. 5 is a perspective view showing a first embodiment of the linear motor according to the present invention, and shows the linear motor constituting the vertical drive mechanism 168 of the surface mounter MT. FIG. 6 is a cross-sectional view of the linear motor of FIG. FIG. 7 is an exploded perspective view of the linear motor of FIG. In these drawings and the drawings described later, XYZ rectangular coordinate axes are shown in order to clarify the directional relationship with the surface mounter MT. Of these three directions X, Y, and Z, the Z direction corresponds to the “movement direction” of the present invention, the Y direction corresponds to the “width direction” of the present invention, and the X direction corresponds to the “movement direction” and the “width direction”. Corresponds to the “thickness direction” orthogonal to both directions.

  The linear motor LM (LM1 to LM10) has a thin tray-like base plate 1 extending in a predetermined movement direction Z. In the base plate 1, as shown in FIG. 7, the inner bottom surface is a base surface 1a, and the (+ Y) direction end, the (−Y) direction end, and the (+ Z) direction end of the base plate 1 are provided. Standing walls 1b to 1d are respectively erected in the thickness direction (+ X), and a recessed portion 1e that opens upward (+ X) is formed by the standing walls 1b to 1d and the base surface 1a. And the component of linear motor LM is accommodated in the said recessed part 1e so that it may mention later. In this embodiment, the base surface 1a and the standing walls 1b to 1d are integrally formed with an aluminum alloy or the like to form the nonmagnetic base plate 1, but the base surface 1a and the standing walls 1b to 1d are individually formed. In addition, the base plate 1 may be configured by assembling these components. Although the base plate 1 is made of a non-magnetic material in this way, it goes without saying that the base plate 1 may be made of a resin material. In FIG. 5, the return spring 15 is not shown, while in FIG. 6, the return spring 15 is indicated by a one-dot chain line.

  On the base surface 1a, one linear guide 2 extends in the Z direction. That is, a linear rail 2a extending in the movement direction Z is fixed to the base plate 1, and two sliders 2b1, 2b2 are slidable in the movement direction Z along the rail 2a (restricted in the Y direction and the X direction). Has been attached). Further, two linear guide stoppers 2c1 and 2c2 can be attached to the base surface 1a of the base plate 1 in order to prevent the sliders 2b1 and 2b2 from falling off from the rail 2a.

  Further, a movable base 4 having a reverse concave shape or an H-shaped cross section is attached to the sliders 2b1 and 2b2, and is movable in the Z direction. More specifically, the movable base 4 has an internal space having a reverse concave shape in the XY cross section, and the movable base 4 is in a state where the ceiling surface of the internal space is located on the upper surfaces of the sliders 2b1 and 2b2. It is fixed to 2b1, 2b2. In order to reduce the weight of the movable base 4, a plurality of through holes 4 a are formed on the ceiling surface of the movable base 4 in the present embodiment. As described above, in this embodiment, the movable base 4 and the sliders 2b1 and 2b2 are integrally movable in the movement direction Z, which corresponds to the “movable part” of the present invention. As described below, the mover is attached to the (−Y) side end side surface of the movable base 4, while the linear scale 7 b is attached to the (+ Y) side end side surface.

  FIG. 8 is a perspective view showing the mounting structure of the movable member and the mover, and FIG. 9 is a view showing the mounting structure of the movable member, the mover, and the linear scale. As shown in these drawings, a yoke 5 made of a ferromagnetic material is attached to the (−Y) side end side surface of the movable base 4, and the N pole side faces the surface of the yoke 5. A plurality of permanent magnets 6 and 14 permanent magnets whose S poles face the surface are alternately arranged along the Z direction (14 in this embodiment). Thus, the mover of the linear motor LM is configured. Moreover, in this embodiment, the permanent magnet 6 is molded by the resin layer 10 to protect the surface, and the permanent magnet 6 can be effectively prevented from being damaged. Further, on the (−Y) side end side surface of the movable base 4, two female screw portions 4 b are formed on the (−Z) side of the mover (yoke 5 + permanent magnet 6). These female screw portions 4b are for attaching a driven object to the (−Y) side end of the movable base 4 directly or via a connecting portion. In the surface mounter MT, the female screw portion 4b is used. A connecting portion 164 is connected to the movable base 4, and a nozzle shaft 163 is connected to the connecting portion 164 as a driven object.

  The armature 3 corresponding to the “stator” of the present invention is disposed on the width direction (−Y) side of the mover (permanent magnet 6 + yoke 5) configured as described above, and is fixed to the base surface 1a of the base plate 1. ing. The armature 3 includes a core 3a, a plurality of hollow bobbins 3b, and a coil 3c formed by winding an electric wire around the outer periphery of each bobbin 3b. The core 3a is formed by laminating a plurality of comb-shaped silicon steel plates having tooth portions provided in a (+ Y) direction at regular intervals from a rectangular plate portion extending in the Z direction in the X direction. In the core 3a configured as described above, a plurality of tooth portions are arranged in parallel in the Z direction at a constant interval to form a tooth portion row. A bobbin 3b around which a coil 3c is wound is attached to each tooth portion. Thus, a plurality of (9 in this embodiment) tooth portions of the core 3a and coils 3c wound around the tooth portions are provided at the same interval in the Z direction to constitute the armature 3, and the mover Opposing to the (permanent magnet 6 + yoke 5). In the present embodiment, as shown in FIG. 6B, the front end surface 8 of the tooth portion of the core 3a around which the coil 3c is wound and the permanent magnet 6 of the mover that is the opposing surface of the front end surface 8 are opposed to each other. The armature 3 is configured so that the common normal 8a with the surface 8 ′ is parallel to the YZ plane including the moving direction Z and the width direction Y. When a motor controller (not shown) energizes each coil 3c in a predetermined order, the mover (permanent magnet 6 + yoke) is generated by the interaction between the magnetic pole of the tip face 8 and the magnetic pole of the opposing face 8 'as described above. A thrust in the Z direction is generated in 5) to drive the movable base 4 in the Z direction.

  In the linear motor LM according to the first embodiment, the motor body is formed by the base plate 1, the armature 3, the movable base 4, and the movable element (permanent magnet 6 + yoke 5), and has a thickness as shown in FIG. The size of the motor body in the direction X is the height Hm. On the other hand, the height Hs in the thickness direction X of the return spring 15 that urges the movable base 4 upward, that is, in the (+ Z) direction is lower than the height Hm of the motor body and returns to the height range of the motor body. It arrange | positions along the width direction Y with the needle | mover (permanent magnet 6+ yoke 5) and the armature 3 so that the spring 15 may be settled. That is, the return spring 15 is arranged in the thickness direction X without jumping out from the motor body, and the thickness of the linear motor LM in the thickness direction X matches the height Hm of the motor body.

  In this embodiment, since the mover uses a permanent magnet and the stator uses a core 3a made of a magnetic material, there is a cogging force between the teeth of the core 3a and the mover permanent magnet. appear. “Generation of cogging force” means the pulsation of electromagnetic force acting on the armature 3 because the magnetic flux density of the permanent magnet 6 changes according to the position of the tooth portion of the core 3a and the magnetic energy changes accordingly. Is a phenomenon that occurs. Therefore, in order to reduce the cogging force, sub teeth 9 a and 9 b made of a magnetic material are provided at both ends of the tooth row of the armature 3. That is, the sub-tooth 9a is located at a desired position that matches or is different from the tooth pitch on the (+ Z) side of the tooth row, and the sub-tooth 9b is located at a desired position that matches or differs from the tooth row pitch on the (−Z) side. The base plate 1 is detachably provided on the base surface 1a so that the distance from the permanent magnet 6 is a desired distance.

  By the way, in the linear motor LM configured as described above, the plate portion connected to the core 3a extends to the vicinity of the sub teeth 9a and 9b, the armature core and the sub teeth are magnetically coupled, and the magnetic flux density distribution. Will be unevenly distributed. For this reason, there is a case where a stable cogging force reduction function cannot be exhibited only by arranging the sub teeth 9a and 9b at predetermined positions. In particular, during acceleration / deceleration, etc., or when the operating condition (constant moving speed after acceleration) itself changes, the amount of current flowing through the coil 3c changes from the assumed value, and the permanent magnets in the sub teeth 9a, 9b In some cases, the magnetic poles on the opposing surface or the strength thereof are not desired, and the effect of reducing the cogging force by the sub teeth 9a, 9b may not necessarily be obtained. Therefore, in the present embodiment, the magnetic material plate 11 is provided between the sub teeth 9a and 9b and the base plate 1 in order to supplement the effect of reducing the cogging force by the sub teeth 9a and 9b. More specifically, the configuration is as follows.

  FIG. 10 is a plan view showing the positional relationship between the sub teeth and the magnetic plate. In the figure, the magnetic plate 11 is hatched in order to clarify the relative position of the magnetic plate 11 with respect to the sub teeth 9a and 9b and the planar shape of the magnetic plate 11. On the base surface 1a of the base plate 1, a plate fitting portion 1g having substantially the same shape as the planar shape of the magnetic plate 11 is formed in the (−X) direction (see FIG. 6A). The magnetic plate 11 is fitted to the plate fitting portion 1g, and the surface of the magnetic plate 11 is flush with the base surface 1a. By the arrangement of the magnetic material plate 11, the magnetic flux reaching the core 3a through the core 3a, the sub teeth 9a, the permanent magnet 6, the yoke 5, the adjacent permanent magnet 6 and the adjacent tooth portion on the YZ plane. In addition, a magnetic flux on the XY plane that reaches the sub teeth 9a through the sub teeth 9a, the permanent magnet 6, the yoke 5, and the magnetic material plate 11 is generated, and the cogging force is effectively reduced.

  As described above, the movable base 4 is driven in the moving direction Z by the interaction of the magnetic flux generated by the mover (permanent magnet 6 + yoke 5) and the armature 3, but the movable base 4 exceeds the predetermined moving range. In order to prevent this, two movement restricting stoppers 12 a and 12 b can be attached to the base surface 1 a of the base plate 1.

  Further, in order to accurately detect the position of the movable base 4, a detection unit 7 having a sensor 7a and a linear scale 7b is provided on the non-armature side of the movable base 4, that is, the (+ Y) side. The linear scale 7 b extends in the Z direction with respect to the (+ Y) side end side surface of the movable base 4. The sensor 7a is fixedly disposed on the base plate 1 on the (−Y) side of the linear scale 7b. For this reason, the region of the linear scale 7b facing the sensor 7a is displaced according to the movement of the movable base 4 in the Z direction, and the position of the movable base 4 in the movement direction Z can be accurately detected based on the displacement. It has become.

  The sensor 7a is integrally formed with the sensor control unit 7c, and this structure (sensor 7a + sensor control unit 7c) is formed in the recess 1e via a notch 1f formed in the standing wall 1b as shown in FIG. On the other hand, it is removable. That is, the structure is inserted into the base plate 1 through the notch 1f, and as shown in FIG. 6, the sensor 7a is arranged to face the linear scale 7b in the width direction Y, and the sensor control unit 7c is connected to the sensor 7a. It is fixed to the base plate 1 in a state of being arranged on the anti-linear scale side, that is, on the (+ Y) side. In particular, in this embodiment, as shown in FIG. 6C, a common normal line 7f between the surface 7e of the linear scale 7b and the sensing surface 7e 'of the sensor 7a opposite to the surface 7e has a movement direction Z and The mounting positions of the sensor 7a and the linear scale 7b are set so as to be parallel to the YZ plane including the width direction Y. In order to prevent foreign matters such as dust and dirt from entering the sensor control unit 7c, the sensor cover 7d is attached to the standing wall 1b of the base plate 1 so as to cover the sensor control unit 7c after the structure is attached.

  In this embodiment, the linear scale 7b is attached to the movable base 4, while the sensor 7a is disposed on the base plate 1. However, the sensor 7a and the linear scale 7b may be disposed in reverse. Moreover, you may comprise so that one of the components (sensor 7a, linear scale 7b) of the detection unit 7 may be attached to slider 2b1, 2b2 instead of attaching to the movable base 4. FIG. Further, the detection method of the detection unit 7 may be a magnetic method using magnetism or an optical method.

  Next, the configuration and operation of the linear motor LM (LM1 to LM10) constituting the vertical drive mechanism 168 and the laminated structure of the linear motor will be described in detail with reference to FIGS.

  FIG. 11 is a view showing a laminated structure of linear motors. In the surface mounter MT, ten units having the same configuration as that of the single-axis linear motor LM according to the first embodiment are prepared and stacked as follows. Here, for easy understanding, a laminated structure of two linear motors LM1 and LM2 will be described, but the laminated structure of other linear motors is the same. Of the two linear motors, the end surfaces 1b to 1d of one linear motor LM1 are in contact with the back surface of the base plate 1 of the other linear motor LM2 so that the linear motors LM1 and LM2 are stacked in the X direction. The Further, three through holes 1p to 1r are formed in the base plate 1 of each of the linear motors LM1 and LM2. Then, a bolt 13p is inserted so as to pass through the through holes 1p of the linear motors LM1 and LM2, and a nut 14p is screwed to the tip of the bolt 13p. As for the other through holes 1q and 1r, the bolts 13q and 13r are inserted and the nuts are screwed together in the same manner as the through hole 1p. Further, two positioning pins 20 each attached to each single-axis linear motor LM1, LM2 are fitted into the (−X) side end of the through hole 21 (see FIG. 7) to achieve positioning. In this way, the linear motors LM1 and LM2 are fastened and fixed to each other at three locations and integrated to form a two-axis linear motor MLM.

  In the multi-axis linear motor configured as described above, the thin linear motors LM1, LM2,..., LM10 according to the first embodiment are stacked in the X direction. Can be set narrowly. Further, in each of the linear motors LM1, LM2,..., LM10, the thickness (length in the X direction) of all components such as the mover and armature (stator) is less than that of the standing walls 1b to 1d of the base plate 1. In addition, the main components (movable part, armature 3 and movable element) of the linear motor are accommodated in the internal space (accommodation space) of the recess 1e surrounded by the base surface 1a and the standing walls 1b to 1d. For this reason, motor assembly can be easily performed while maintaining the relative positions of the multiple axes with high accuracy.

  In the surface mounter MT described above, ten single-axis linear motors LM configured as described above are stacked in a stacking direction parallel to the normal direction (+ X) of the base surface 1a, so that the multi-axis linear motor MLM is disposed. Since the vertical drive mechanism 168 is formed, the movable parts can be independently driven in the moving direction without causing the movable parts to interfere with each other. Further, as a result of adopting this laminated structure, the internal space (housing space) of the concave portion 1e of the upstream single-axis linear motor located upstream in the stacking direction (+ X) is adjacent to the downstream side of the upstream single-axis linear motor. It is covered with the back surface of the base plate 1 of the downstream single-axis linear motor, that is, the anti-base surface 1k. For this reason, it is possible to effectively prevent foreign matter from entering the upstream single-axis linear motor. In the surface mounter MT, as shown in FIG. 2 and FIG. 4, the side plate SPb opens the opening of the single-axis linear motor LM10 located on the most (+ X) side among the linear motors constituting the vertical drive mechanism 168. It covers and effectively prevents foreign matter from entering the single-axis linear motor LM10.

  The linear motor LM (LM1 to LM10) and the surface mounter MT configured as described above have the following operational effects. According to the linear motor, the mover (yoke 5 + permanent magnet 6), armature (stator) 3, and return spring (biasing member) 15 are arranged along the width direction Y as shown in FIG. Has been placed. For this reason, compared with the linear motor which has arrange | positioned the biasing member (coil spring) in the position remove | deviated from the arrangement | positioning direction of a needle | mover and a stator as described in patent document 1, linear motor LM (LM1-LM10). Thinning is possible. Further, since the height Hs in the thickness direction X of the return spring 15 is set to be lower than the height Hm of the motor body, the return spring 15 increases the thickness of the linear motor LM (LM1 to LM10). Can be prevented.

  In the present invention, the return spring 15 is disposed along the width direction Y together with the movable base 4 and the armature (stator) 3 to reduce the thickness of the linear motor. They may be juxtaposed or may be juxtaposed with the armature (stator) 3. However, considering the positioning accuracy of the movable base 4, it is desirable to arrange the return spring 15 on the side opposite to the movable element in the width direction Y, that is, on the (−Y) side as in the first embodiment. When such an arrangement is adopted, the movable base 4, the mover (yoke 5 + permanent magnet 6), the armature 3 and the return spring 15 are arranged in this order along the width direction Y, and the movable base 4 and the return spring are arranged. 15 is spaced apart. Since one end portion of the return spring 15 is engaged with the spring engaging portion 1h of the base plate 1, the region near the return spring of the base plate 1 may be distorted by the urging force of the return spring 15. The influence can be avoided by the above arrangement configuration, and the movable base 4 can be positioned with high accuracy.

  Further, the mounting position of the movable element on the movable base 4 is not particularly limited, but the mounting position of the movable element on the movable base 4 is the same as that of the movable base 4 in the width direction Y (−) as in the above embodiment. Y) The linear motor LM (LM1 to LM10) can be made thinner than the case where the mover is attached to the upper surface or the lower surface of the movable base 4 by setting the side end portion side surface.

  In the surface mounter MT according to the embodiment, the nozzle shaft 163 is connected to the movable base 4 of the linear motors LM1 to LM10, and the movable base 4 is driven to drive the nozzle shaft 163 in the vertical direction Z. Therefore, the thinning of the linear motors LM1 to LM10 can reduce the size and weight of the head unit 106. This contributes to the downsizing of the surface mounter MT and further increases the moving speed in both XY directions. This greatly contributes to shortening the mounting time. Still further, since the linear motors LM1 to LM10 having a thin shape in the X direction are stacked, the movable bases 4 can be arranged in a narrow pitch in the X direction, and as a result, connected to these movable bases 4. The pitch PT in the X direction between the nozzle shaft 163 and the suction nozzle 161 can be reduced.

  In the above-described embodiment, the return spring 15 is disposed on the front surface of the linear motor LM (LM1 to LM10), and the user can easily access the return spring 15, and the return spring 15 can be attached and replaced. The maintainability is good.

  In the above embodiment, one end of the return spring 15 is engaged with the spring engaging portion 1h of the base plate 1, while the other end is engaged with the spring engaging portion 164c of the connecting portion 164. For example, the other end of the return spring 15 may be engaged with the movable base 4 as shown in FIG. Hereinafter, a second embodiment of the linear motor will be described with reference to FIG.

  FIG. 12 is a view showing a second embodiment of the linear motor according to the present invention, and FIG. 12 (a) is a view taken along the line AA in FIG. 12 (b). In the linear motor LM shown in the figure, two linear guides 2A and 2B are provided on a rectangular base plate 1 in parallel with each other and separated in the width direction Y. In each of the linear guides 2A and 2B, a linear rail 2a is extended with respect to the base plate 1 in a moving direction X perpendicular to the width direction Y and parallel to the surface of the base plate 1, and further to the rail 2a. Along the slider 2b, the slider 2b can slide in the movement direction Z. Between the linear guides 2 </ b> A and 2 </ b> B configured in this manner, a plurality of coils are arranged in the Z direction in a sleeper state with respect to the surface of the base plate 1, and an armature 3 is formed. Function. In FIG. 9A, only the coil provided closest to the (−Z) direction among the plurality of coils constituting the armature 3 is shown.

  Further, a table-like movable base 4 having the same width (length in the width direction Y) as the base plate 1 is attached to the upper surface of the slider 2b of the linear guides 2A and 2B, and moves in the Z direction above the base plate 1 It is free. In this way, the movable base 4 and the two sliders 2b are integrally movable in the Z direction as “movable portions”.

  On the back side of the movable base 4, yokes 5 </ b> A and 5 </ b> B with a plurality of permanent magnets attached so as to sandwich the armature 3 are attached as movers. That is, although not shown in the figure, the yokes 5A and 5B are both extended in the direction perpendicular to the paper surface of FIG. A plurality of permanent magnets are arranged along the line. In FIG. 9A, only the permanent magnets 6A and 6B provided on the most (−Z) direction side among the permanent magnets are shown. The upper end of the yoke 5A is attached to the back surface of the movable base 4 so that the plurality of permanent magnets 6A face the (+ Y) direction end of the armature 3, while the (−Y) direction end A yoke 5B is attached to the back surface of the movable base 4 so that a plurality of permanent magnets 6B face each other. Therefore, by controlling the current applied to the coil of the armature 3, the movable base 4 is linearly driven in the Z direction by the interaction of the magnetic flux generated in the permanent magnets 6A and 6B of the mover and the stator (armature 3). Is done.

  Furthermore, a return spring 15 corresponding to the “biasing member” of the present invention is arranged on the side opposite to the movable element, that is, on the (+ Y) side of the linear guide 2A. The end of the return spring 15 on the (+ Z) side is engaged with the spring engaging portion 1 h of the base plate 1, while the end of the (−Z) side is on the engaging portion 4 c protruding from the back surface of the movable base 4. Is engaged. The return spring 15 biases the movable base 4 in the (+ Z) direction.

  Also in the linear motor LM configured as described above, the mover (yoke 5A, 5B + permanent magnet 6A, 6B), armature (stator) 3 and return spring (biasing member) are the same as in the first embodiment. 15 is arranged along the width direction Y. For this reason, the linear motor LM can be made thinner as compared with a linear motor in which an urging member (coil spring) is arranged at a position deviated from the arrangement direction of the mover and the stator as described in Patent Document 1. It has become. Further, since the height Hs in the thickness direction X of the return spring 15 is set to be lower than the height Hm of the motor body, it is possible to prevent the return spring 15 from increasing the thickness of the linear motor LM. it can. In such a thinned linear motor LM, the return spring 15 may have a small diameter and a short length, and a single return spring may not provide a desired urging force. In such a case, it is possible to provide a plurality of return springs in order to obtain a required urging force. For example, the linear motor LM shown in FIG. 12 is configured so that a desired urging force can be obtained by additionally arranging a return spring on the side opposite to the movable element of the linear guide 2B in the width direction Y, that is, the (−Y) side. Also good.

  In the first embodiment of the linear motor described above, the yoke 5 is attached to the movable base 4 fixed to the sliders 2b1 and 2b2, and the permanent magnet 6 is attached to the yoke 5, and the slider in the second embodiment of the linear motor. The yokes 5A and 5B are attached to the movable base 4 fixed to 2a and 2b, and the permanent magnets 6A and 6B are attached to the yokes 5A and 5B, respectively. Permanent magnets 6 may be directly extended in the Z direction on the base 4 to form a magnetic circuit. Further, in the first embodiment, the sliders 2b1 and 2b2 may be attached, and in the second embodiment, the yokes may be attached to the side surfaces of the sliders 2a and 2b in the width direction Y, and a permanent magnet may be attached to the yoke. In this case, the sliders 2b, 2b1 and 2b2 correspond to the “movable part” of the present invention. Furthermore, the slider may be made of a ferromagnetic material, and a magnetic circuit may be formed by extending a permanent magnet directly in the Z direction on the side surface of the slider in the width direction Y.

  Moreover, in the said 1st Embodiment and 2nd Embodiment, while the mover is comprised with the permanent magnet 6, while the stator is comprised with the armature 3, while the mover is comprised with an electromagnetic, on the other hand, the stator You may apply this invention with respect to the linear motor which comprised this with the permanent magnet.

  In the surface mounter MT, the multi-axis linear motor MLM having the same configuration as that of the single-axis linear motor LM according to the first embodiment is used as the vertical drive mechanism, but the single-axis linear motor LM according to the second embodiment is used. A plurality of linear motors according to the present invention, such as a multi-axis linear motor using the same configuration as the shaft linear motor LM, and a multi-axis linear motor combining the single-axis linear motor according to the first and second embodiments. The provided one can be used.

  Further, in the above embodiment, the present invention is applied to the surface mounter MT that functions as a component transfer device, but the application target of the present invention is not limited to this, and components such as an IC handler The present invention can also be applied to a transfer device.

It is a top view which shows schematic structure of the surface mounter which is one Embodiment of the components transfer apparatus concerning this invention. It is the front view and side view of a head unit. It is a block diagram which shows the electric constitution of the surface mounter shown in FIG. It is a figure which shows the structure of an up-down drive mechanism. 1 is a perspective view showing a first embodiment of a linear motor according to the present invention. It is AA sectional view taken on the line of the linear motor of FIG. FIG. 6 is an exploded perspective view of the linear motor of FIG. 5. It is a perspective view which shows the attachment structure of a movable member and a needle | mover. It is a figure which shows the attachment structure of a movable member and a needle | mover. It is a top view which shows the arrangement | positioning relationship between a sub-tooth and a magnetic body plate. It is a figure which shows the laminated structure of a linear motor. It is a figure which shows 2nd Embodiment of the linear motor concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base plate 1h, 4c, 164c ... Spring engaging part 2a ... Rail 2b, 2b1, 2b2 ... Slider 3 ... Armature 4 ... Movable base (movable part)
DESCRIPTION OF SYMBOLS 5 ... Yoke 6 ... Permanent magnet 15 ... Return spring 106 ... Head unit 107 ... Head drive mechanism 161 ... Adsorption nozzle 163 ... Nozzle shaft 168 ... Vertical drive mechanism LM, LM1-LM10 ... Single-axis linear motor MLM ... Multi-axis linear motor MT ... Surface mounter (component transfer equipment)
X: Thickness direction (normal direction of base surface)
Y ... width direction Z ... moving direction

Claims (9)

A base plate;
A movable part that is movable in a predetermined movement direction with respect to a base surface of the base plate;
A mover extending in the moving direction with respect to the movable part;
A stator extending in the moving direction with respect to the base surface of the base plate so as to be opposed to the mover in a width direction orthogonal to the moving direction;
An urging member that is arranged along the width direction together with the movable portion and the stator and urges the movable portion toward one side of the moving direction;
A linear motor characterized in that a driving force larger than an urging force of the urging member is generated by an interaction of magnetic fluxes generated by the mover and the stator to drive the movable part in the moving direction. A linear rail extending in the moving direction with respect to the base surface of the base plate;
The movable part includes a slider provided slidably in the moving direction along the rail, and a movable base attached to the slider.
The linear motor according to claim 1, wherein the movable element is attached to an end side surface of the movable base in the width direction. A linear rail extending in the moving direction with respect to the base surface of the base plate;
The movable part has a slider that is slidable in the moving direction along the rail,
The linear motor according to claim 1, wherein the mover is attached to an end side surface of the slider in the width direction.   The linear motor according to claim 1, wherein the urging member is disposed on a side opposite to the movable element of the stator in the width direction.   The linear motor according to claim 1, wherein the urging member is disposed on a front surface of the base plate in the width direction.   The linear motor according to claim 1, wherein the biasing member is a spring member having one end attached to the base plate and the other end attached to the movable part. The linear motor according to any one of claims 1 to 5, wherein a driven object is driven in the moving direction via a connecting member attached to the movable part,
The biasing member is a linear motor that is a spring member having one end attached to the base plate and the other end attached to the connecting member.   The height Hs of the urging member in the thickness direction orthogonal to both the width direction and the moving direction is the height in the thickness direction of the motor main body portion composed of the base plate, the movable portion, the mover, and the stator. The linear motor according to claim 1, which is lower than the height Hm. In the component transfer device that transfers components from the component storage unit to the component mounting area,
The base member is supported so as to be movable in the vertical direction with respect to the base member, and a suction nozzle is attached to the front end portion, and the negative pressure supplied through a negative pressure pipe connected to the rear end portion is suctioned. A head unit having a nozzle shaft to be provided to the nozzle and a vertical drive mechanism for driving the nozzle shaft in the vertical direction;
A head driving means for moving the head unit between an upper position of the component housing portion and an upper position of the component mounting area;
The vertical drive mechanism is the linear motor according to any one of claims 1 to 8,
The linear motor is attached to the base member such that the moving direction is parallel to the vertical direction, and the urging member urges the movable portion upward.
The component transfer apparatus, wherein the movable part of the linear motor is connected to the nozzle shaft.

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