JP2009171664A - Linear motor and component transfer apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably highly accurately drive a movable section by reducing a cogging force in a so-called movable magnet type linear motor and a component transfer apparatus using the linear motor. <P>SOLUTION: While a movable base 4 moves in a moving direction Z, both sub-teeth 9a, 9b oppose a permanent magnet column, and above-described two kinds of magnetic fluxes are generated in the vicinity of each of the sub-teeth 9a, 9b, and the effect of reduction of a cogging force by the sub-teeth 9a, 9b is continuously obtained. A magnetic plate 11 is provided, so that a magnetic circuit to the sub-teeth 9a through the sub-teeth 9a, a permanent magnet 6, a yoke 5 and the magnetic plate 11 is formed, and thus, the cogging force is reduced efficiently and further stably. As a result, the movable base 4 is highly accurately driven in a moving direction Z. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  The linear motor includes a primary element in which a plurality of armature windings (coils) are arranged in a magnetic core, and a secondary element in which a plurality of permanent magnets are arranged in a yoke made of a ferromagnetic material. The permanent magnet is spaced apart from the armature winding. The primary side element (or secondary side element) becomes the secondary side element (or primary side element) by moving the magnetic field of the magnetic pole core by controlling the drive current applied to the armature winding. Move relative to it. As such a linear motor, for example, as described in Patent Document 1, a mover in which a plurality of field permanent magnets are arranged in a row in a moving direction and a plurality of armature windings in the moving direction. A so-called movable magnet type linear motor has been proposed in which stators arranged in a row are opposed to each other via an air gap.

Japanese Patent No. 3818342 (FIG. 2) Japanese Patent Laying-Open No. 2005-253259 (FIG. 2)

  By the way, the needle | mover of the linear motor of patent document 1 has a permanent magnet row | line | column formed by arranging the several field permanent magnet in a moving direction. On the other hand, in the stator, divided cores wound with armature windings are connected in a row in a plurality of movement directions, and the stator length in the movement direction is longer than that of the permanent magnet row. Then, the mover is driven in the moving direction by the interaction of magnetic fluxes generated by the mover and the stator. However, when the mover moves around the end in the moving direction of the stator, a relatively large cogging force is generated, which makes it difficult to perform stable driving and highly accurate positioning.

  In order to solve this problem, for example, as described in Patent Document 2, it is conceivable to additionally arrange sub teeth. However, there are cases where the armature core and the sub-teeth are magnetically coupled and the magnetic flux density distribution is unevenly distributed, so that a stable cogging force reduction function cannot be exhibited. As a result, it has been difficult to stably drive the mover with high accuracy.

  The present invention has been made in view of the above problems, and a first object of the present invention is to reduce the cogging force in a so-called movable magnet type linear motor and stably drive the movable portion with high accuracy.

  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 includes a base plate, a linear rail extending in a predetermined movement direction with respect to the base surface of the base plate, and a movement direction along the rail. A movable part provided movably, a mover having a permanent magnet array in which a plurality of permanent magnets are arranged in the movement direction with respect to the movable part, and a plurality of tooth parts extending from the base part are arranged in a row to form a tooth A permanent magnet array having a core constituting a part array and a plurality of armature windings wound around each tooth part, the tooth part array being parallel to the moving direction and perpendicular to the moving direction Fixed on the base surface of the base plate so as to be opposed to each other, sub teeth disposed on at least one of both ends of the tooth row in the moving direction, and a magnetic plate provided on the base plate And width The end of the magnetic plate on the stator side is in contact with or close to the sub-tooth, while the end of the mover side of the magnetic plate is extended in the width direction toward the permanent magnet row and is arranged close to the mover. It is characterized by being.

  In the invention configured as described above, the armature winding wound around each tooth portion constituting the tooth row is fixed on the base surface of the base plate as a stator, while a plurality of permanent magnets are arranged in rows. The movable part is provided in the movable part as a movable element, and the movable part is driven in the moving direction by a so-called movable magnet system. The sub teeth are arranged at least one of both end portions of the tooth row in the moving direction, and the base plate is provided with a magnetic material plate. The magnetic material passes through the sub teeth, the armature core, the permanent magnet, and the yoke. In addition to the circuit, a magnetic circuit is formed through the sub teeth, the magnetic plate, the permanent magnet, and the yoke. For this reason, it becomes possible to further enhance the cogging force reduction effect only by forming the magnetic circuit via the sub teeth, the armature core, and the permanent magnet. Therefore, the movable part can be stably driven in the moving direction, and the movable part can be positioned with high accuracy.

  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 is attached to the base member so that the moving direction is parallel to the vertical direction. Parts 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. Therefore, the component transfer by the suction nozzle attached to the tip of the nozzle shaft can be performed stably and with high accuracy, and the reliability of the apparatus can be improved.

  The present invention relates to a linear motor that linearly moves a movable portion with respect to a base plate, and a component transfer device using the linear motor. In the following, the linear motor according to the present invention and the linear motor will be described. This will be described in detail separately for the surface mounter which is an embodiment of the used component transfer apparatus.

<Linear motor>
FIG. 1 is a perspective view showing an embodiment of a linear motor according to the present invention. FIG. 2 is a cross-sectional view of the linear motor of FIG. FIG. 3 is an exploded perspective view of the linear motor of FIG. In these drawings and the drawings to be described later, XYZ rectangular coordinate axes are shown in order to clarify the directional relationship between the drawings. 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 has a thin tray-like base plate 1 extending in a predetermined movement direction Z. In this base plate 1, as shown in FIG. 3, 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 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. 1 and 2 denotes a spring engaging portion for attaching a return spring.

  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. 4 is a perspective view showing the mounting structure of the movable member and the movable element, and FIG. 5 is a diagram showing the mounting structure of the movable member and the movable element. 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 portion of the movable base 4 directly or via a connecting portion. For example, in a surface mounter described later, a connecting portion is connected to the movable base 4 using a female screw portion 4b, and a nozzle shaft is connected to the connecting portion as a driven object. That is, the driven object can be attached to the movable base 4 via the coupling portion that is coupled to the end portion of the movable base 4 using the female screw portion 4b. This will be described in detail later in the section “Surface Mounter”.

  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 (armature winding) 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. 2B, 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 a 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 this embodiment, the rectangular plate portion of the core 3a corresponds to the “base” of the present invention, and an armature in which a coil (armature winding) 3c is wound around each of a plurality of tooth portions extending from the rectangular plate portion. 3 is fixed on the base surface 1a of the base plate 1 as a stator. On the other hand, a movable element having a permanent magnet row in which a plurality of permanent magnets 6 are arranged in a row in the movement direction Z is provided on the movable base 4. Thus, the movable base 4 is driven in the movement direction Z by a so-called movable magnet system. Note that the movement range of the movable base 4 is restricted by two movement restriction stoppers 12a and 12b, which will be described later, and a position corresponding to the movement restriction stopper 12a (one end side in the movement direction (+ Z): FIG. 6A). The movable base 4 is movable between a position corresponding to the movement restriction stopper 12b (the other end side in the movement direction (-Z): FIG. 6B).

  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.

  As shown in FIGS. 3 and 6, the sub teeth 9a are formed separately from the core 3a, and the end surface 9a1 on the side opposite to the permanent magnet 9a of the sub teeth 9a in the width direction Y is a rectangular plate portion (base) of the core 3a. It is arranged at a position in contact with or close to. More specifically, the sub teeth 9a are approached from the normal direction (+ X) side of the base surface 1a of the base plate 1 toward the base surface 1a and placed on the base surface 1a. In this way, while the sub teeth 9a are arranged on the base surface 1a, a fastening member 9c such as a screw is applied to the sub teeth 9a from the same direction, that is, the normal direction (+ X) side, to fix the sub teeth 9a to the base plate. On the other hand, when replacing or adjusting the position of the sub-tooth 9a, the fixing of the sub-tooth 9a can be released by accessing the fastening member 9c from the normal direction (+ X) side. Furthermore, it is also possible to remove the sub teeth 9a from the base surface 1a in the normal direction (+ Z) after the fixation is released. As described above, in the present embodiment, the placement, fixing, and removal work of the sub teeth 9a can be performed from the normal direction (+ X) side. Is excellent.

  Moreover, the following effect is obtained by forming separately from the core 3a and making it detachable with respect to the base plate 1. FIG. The sub teeth 9a are closely related to the effect of reducing the cogging force. The effect of reducing the cogging force can be achieved by changing the shape, size, material, etc. of the sub teeth 9a and adjusting the arrangement position of the sub teeth 9a. Can be adjusted. That is, when performing the adjustment work, it is necessary to perform operations such as unfixing, changing the arrangement, removing, and remounting the sub teeth 9a. However, in the linear motor LM configured as described above, any work is required. Can be performed from the normal direction (+ Z) side, and the adjustment operation can be performed easily and with high accuracy. The (−Z) side sub-teeth 9b is exactly the same as the (+ Z) side sub-teeth 9a.

  By the way, in the linear motor LM configured as described above, a satisfactory cogging force reduction effect may not be obtained 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 this embodiment, the magnetic plate 11 is provided on the base plate 1 in order to compensate for the effect of reducing the cogging force by the sub teeth 9a and 9b. More specifically, the configuration is as follows.

  FIG. 7 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. 2A). 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. Thus, the single magnetic plate 11 is provided so as to cover the mover side end 9a2 of the sub teeth 9a, the mover side end 9b2 of the sub teeth 9b, and the mover from the (−X) direction side. . That is, the (−Y) side end portion, that is, the stator side end portion 11a of the both ends of the magnetic plate 11 in the width direction Y extends between the sub teeth 9a and 9b in the moving direction Z and is fixed. The (+ Z) side portion of the child-side end portion 11a contacts the sub teeth 9a, and the (−Z) side portion contacts the sub teeth 9b. In the present embodiment, the magnetic plate 11 and the sub teeth 9a are in contact with each other, but they may be arranged close to each other. On the other hand, the mover side end portion 11b of the magnetic plate 11 extends in the width direction (+ Y) toward the permanent magnet row of the mover and is disposed close to the mover and the movable base 4 as shown in FIG. Yes. For this reason, two types of magnetic circuits are formed in the vicinity of the sub teeth as described below.

  FIG. 8 is a diagram showing a configuration near the sub teeth and a magnetic circuit formed near the sub teeth. Here, the magnetic circuit formed in the vicinity of the (+ Z) side sub-tooth 9a will be described, but the (−Z) side sub-teeth 9b is the same as that of the (+ Z) side sub-teeth 9a, and accordingly, a corresponding symbol is attached. The description is omitted. In the linear motor LM configured as described above, since the sub teeth 9a are arranged at the (+ Z) side end of the tooth row, as indicated by the thick solid line in FIG. On the surface, a magnetic circuit reaching the core 3a is formed through the core 3a, the sub teeth 9a, the permanent magnet 6, the yoke 5, the adjacent permanent magnet 6, and the teeth adjacent to the sub teeth. Magnetic flux passes through. Since this magnetic flux flows into the core 3a of the armature 3, the magnetic poles of the sub teeth 9a, 9b facing the permanent magnet 6 are not desired as described above, and a stable cogging force reduction function cannot be exhibited. There is a case.

  On the other hand, by providing the magnetic plate 11, another magnetic circuit is additionally formed in addition to the above magnetic circuit. This reaches the sub teeth 9a through the sub teeth 9a, the permanent magnet 6, the yoke 5, and the magnetic material plate 11, as indicated by the thick solid line in FIG. The magnetic flux along the magnetic circuit is not affected by the current value of the electromagnet adjacent to the sub teeth 9a and has a certain strength. Therefore, a stable magnetic circuit can be formed between the sub teeth 9a and 9b and the permanent magnet, and as a result, the cogging force can be effectively reduced. Thus, in order to suppress the influence of the current value of the electromagnet, it is desirable to set the contact or proximity position of the magnetic material plate 11 and the sub teeth 9a, 9b to the mover side, that is, the (+ Y) side. In the embodiment, as described above, the stator side end portion 11a of the magnetic plate 11 is brought into contact with or close to the mover side end portions 9a2 and 9b2 of the sub teeth 9a and 9b in the width direction Y.

  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. 2, 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. 2 (c), a common normal line 7f between the surface 7e of the linear scale 7b and the sensing surface 7e 'of the sensor 7a facing 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.

  As described above, in the linear motor LM according to this embodiment, the movable base 4 is driven in the movement direction Z within a predetermined movement range by a so-called movable magnet method. This movement range is restricted by two movement restriction stoppers 12a and 12b. That is, at one end side (+ Z) in the movement direction in the movement range, as shown in FIG. 6A, the permanent magnet 6a located closest to the (−Z) side in the permanent magnet row is on the (−Z) side. While facing the sub teeth 9b, one of the permanent magnets arranged on the (+ Z) side of the permanent magnet 6a faces the (+ Z) side sub teeth 9a. Here, “opposing the permanent magnet 6a and the sub teeth 9b” means that the permanent magnet 6a and the sub teeth 9b are completely or partially overlapped when viewed in the width direction Y. When the permanent magnet 6a and the sub teeth 9b are projected onto the XZ plane, the permanent magnet 6a and the sub teeth 9b are positioned so that the projected images formed on the virtual XZ plane completely or partially overlap ( This point is the same for “opposing the permanent magnet 6b and the sub teeth 9a” described below). On the other hand, on the other end side (−Z) in the movement direction in the movement range, as shown in FIG. 6B, the permanent magnet 6b located closest to the (+ Z) side in the permanent magnet row is on the (+ Z) side. While facing the sub teeth 9a, one of the permanent magnets arranged on the (−Z) side of the permanent magnet 6b faces the (−Z) side sub teeth 9b. In this way, while the movable base 4 moves in the movement direction Z, each of the sub teeth 9a and 9b is opposed to the permanent magnet row, and the above-described two types of magnetic flux are generated in the vicinity of the sub teeth 9a and 9b. Thus, the effect of reducing the cogging force by the sub teeth 9a and 9b can be continuously obtained. In particular, in the present embodiment, by providing the magnetic plate 11, the magnetic circuit shown in FIG. 8B can be formed to effectively and stably reduce the cogging force. As a result, the movable base 4 can be stably driven in the movement direction Z with high accuracy.

  Further, in the present embodiment, the magnetic circuit shown in FIG. 8B is formed on both sides of the sub teeth 9a and 9b by the single magnetic plate 11, so that the sub teeth 9a and 9b are magnetically provided as will be described later. Compared with the case where the body plate 11 is provided, the number of parts can be reduced, the mounting work of the magnetic body plate 11 is simple, and the positioning adjustment of the magnetic body plate 11 with respect to the sub teeth 9a, 9b is also performed once. Can do. Therefore, the assembly workability and maintenance performance of the linear motor LM are excellent.

  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) By setting the side end side surface, the linear motor LM can be made thinner than when the mover is attached to the upper surface or the lower surface of the movable base 4.

  In the above embodiment, the movable base 4 and the armature (stator) 3 are arranged on the (−Y) side of the movable base 4 to drive the movable base 4, while the detection unit 7 is arranged on the (+ Y) side. Since the position of the movable base 4 is detected, the linear motor LM can be downsized in the width direction Y, and the linear motor LM can be made compact.

  The linear motor according to the present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the gist thereof. For example, in the above-described embodiment, the sub teeth 9a and 9b are covered from the (−X) direction side by the single magnetic plate 11, but for example, as shown in FIG. 9, the sub teeth 9a and 9b are provided for each of the sub teeth 9a and 9b. A magnetic plate 11 may be disposed. In this case, the area of the magnetic plate 11 can be minimized as compared with the embodiment shown in FIG. 7, and the component cost and product weight can be reduced.

  In the above embodiment, the magnetic plate 11 is disposed on the base surface 1 a. However, the magnetic plate 11 may be formed in the base plate 1 at the stage of manufacturing the base plate 1. That is, the base plate 1 is molded by high pressure casting of aluminum alloy (so-called aluminum die casting), and the magnetic plate 11 is cast at the time of molding, so that the magnetic plate 11 can be arranged simultaneously with the production of the base plate 1 (FIG. 10). reference). This configuration can also be applied to a linear motor that forms a base plate 1 by molding a resin material. For example, a magnetic plate may be integrally formed on a resin base plate by insert formation. That is, in the movable magnet type linear motor using the base plate 1 formed by molding a nonmagnetic material, the magnetic material plate can be integrally formed when the base plate is molded.

  Moreover, in the said embodiment, although the sub teeth 9a and 9b are provided in the both ends of the tooth | gear part row | line | column of the armature 3, the sub body is provided in either one and the magnetic body plate 11 is provided corresponding to the said sub teeth. As a result, the effect of reducing the cogging force by the sub teeth can be obtained reliably and stably.

  Moreover, in the said embodiment, although the sub teeth 9a and 9b and the magnetic body plate 11 are formed separately from each other, you may integrally form both.

  Moreover, in the said embodiment, although the internal thread part 4b is provided in the side surface of the (-Z) side edge part of the movable base 4, and it is comprised so that a to-be-driven object can be connected, a thread part is provided in the upper surface of the movable base 4. The driven object may be directly attached to the movable base 4 using a screw portion. Alternatively, a table may be fixed to the movable base 4 using a screw portion, and the driven object may be attached to the movable base 4 via the table.

  In the above-described embodiment, the movable base 4 is driven by arranging the mover and the armature (stator) 3 only on the (−Y) side of the movable base 4, but the (+ Y) side of the movable base 4 is driven. Alternatively, a mover and an armature (stator) 3 may be arranged. With this configuration, the driving force for driving the movable base 4 can be further increased. In this case, also on the (+ Y) side of the movable base 4, as in the above-described embodiment, the sub teeth are disposed at at least one of both ends of the tooth row in the movement direction Z, and corresponding to the sub teeth. It is desirable to form a magnetic circuit that reaches the sub-tooth through the sub-teeth, the permanent magnet, the yoke, and the magnetic plate by arranging the magnetic plate.

  In the above embodiment, the yoke 5 is attached to the side surface in the width direction Y of the movable base 4 fixed to the sliders 2b1 and 2b2, and the permanent magnet 6 is attached to the yoke 5. It may be made of a magnetic material, and the permanent magnet 6 may be directly extended in the Z direction on the side surface in the width direction Y of the movable base 4 to form a magnetic circuit. Moreover, in the said embodiment, the yoke 5 may be attached to the edge part side surface of the width direction Y of slider 2b1, 2b2, and the permanent magnet 6 may be further attached to the said yoke 5. FIG. In this case, the sliders 2b1 and 2b2 correspond to the “movable part” of the present invention. Further, the slider may be made of a ferromagnetic material, and the permanent magnet 6 may be directly extended in the Z direction on the side surface of the end in the width direction Y of the slider to form a magnetic circuit.

  Each of the above embodiments is a so-called single-axis linear motor. However, as shown in FIG. 11, two single-axis linear motors LM1 and LM2 may be combined to form a multi-axis linear motor MLM.

  FIG. 11 is a perspective view showing another embodiment of the linear motor according to the present invention. In this embodiment, two single-axis linear motors having the same configuration are prepared, and the (+ X) side end surfaces of the standing walls 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. Thus, the linear motors LM1 and LM2 are stacked in the X direction to form a multi-axis linear motor MLM. 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 attached to each of the single-axis linear motors LM1 and LM2 are fitted to the (−X) side end portions of the through holes 21 (see FIG. 3) 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 two-axis linear motor MLM configured as described above, the thin linear motors LM1 and LM2 shown in FIG. 1 are stacked in the X direction, so that the pitch of the two axes in the X direction can be set narrow. . Further, in each of the linear motors LM1, LM2, the thickness (length in the X direction) of all components such as the mover and the armature (stator) is less than that of the standing walls 1b to 1d of the base plate 1, and The main components (movable part, armature 3 and mover) of the linear motor are accommodated in a recess 1e surrounded by a base surface 1a and standing walls 1b to 1d. For this reason, motor assembly can be easily performed while maintaining the relative positions of the two axes with high accuracy.

  The number of single-axis linear motors to be combined is not limited to “2”, and a multi-axis linear motor MLM can be configured by combining three or more single-axis linear motors. For example, the surface mounting machine described below is equipped with a vertical drive mechanism that drives each suction nozzle in the vertical direction in order to transfer components using 10 suction nozzles. A multi-axis linear motor MLM combining LM1 to LM10 can be used as the vertical drive mechanism.

<Surface mounter>
FIG. 12 is a plan view showing a schematic configuration of a surface mounter which is an embodiment of the component transfer apparatus according to the present invention. FIG. 13 is a front view and a side view of the head unit. Further, FIG. 14 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 described above 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 upper side to the lower 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. 13, 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. 15 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. . These single-axis linear motors LM1 to LM10 are stacked in the X direction. 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. 3) 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. Accordingly, the movable base 4 is accommodated in the base plate 1 while the current supply to the coils 3c of the linear motors LM1 to LM10 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.

  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.

  As described above, in the surface mounter according to this embodiment, the multi-axis linear motor MLM formed by stacking the 10 linear motors LM1 to LM10 having the same configuration as the linear motor LM shown in FIG. Since the nozzle shaft 163 is configured to be driven up and down in the vertical direction Z, the component transfer by the suction nozzle 161 attached to the tip of the nozzle shaft 163 can be stably performed with high accuracy. The reliability of the apparatus can be increased.

<Others>
In the above embodiment, the present invention is applied to the surface mounter MT that functions as a component transfer device. However, 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.

1 is a perspective view showing an embodiment of a linear motor according to the present invention. It is the sectional view on the AA line of the linear motor of FIG. FIG. 2 is an exploded perspective view of the linear motor of FIG. 1. 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 figure which shows the relative positional relationship of a subtooth and a permanent magnet row | line | column. 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 structure near a sub-tooth, and the magnetic circuit formed in the sub-teeth vicinity. It is a figure which shows another embodiment of the linear motor concerning this invention. It is a figure which shows another embodiment of the linear motor concerning this invention. It is a perspective view which shows other embodiment of the linear motor concerning this invention. 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. FIG. 13 is a block diagram showing an electrical configuration of the surface mounter shown in FIG. 12. It is a figure which shows the structure of an up-down drive mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base plate 1a ... Base surface 2a ... Rail 2b1, 2b2 ... Slider 3 ... Armature (stator)
3a ... Core 3c ... Coil (armature winding)
4 ... Movable base (movable part)
DESCRIPTION OF SYMBOLS 5 ... Yoke 6 ... Permanent magnet 9a, 9b ... Sub teeth 9a2, 9b2 ... (Mount side end part of sub teeth) 106 ... Head unit 107 ... Head drive mechanism 161 ... Adsorption nozzle 163 ... Nozzle shaft 168 ... Vertical drive mechanism LM , LM1 to LM10 ... Linear motor MLM ... Multi-axis linear motor MT ... Surface mounter (component transfer device)
X: Thickness direction (normal direction of base surface)
Y ... width direction Z ... moving direction

Claims (9)

A base plate;
A linear rail extending in a predetermined movement direction with respect to the base surface of the base plate;
A movable part provided to be movable in the moving direction along the rail;
A mover having a permanent magnet row in which a plurality of permanent magnets are arranged in the moving direction with respect to the movable part;
A plurality of tooth portions extending from the base portion arranged in a row to form a tooth portion row, and a plurality of armature windings wound around each tooth portion; A stator fixed on the base surface of the base plate so as to be opposed to the permanent magnet row in a width direction parallel to the moving direction and perpendicular to the moving direction;
Sub teeth disposed on at least one of both ends of the tooth row in the moving direction;
A magnetic plate provided on the base plate,
The stator side end of the magnetic plate in the width direction is in contact with or close to the sub-tooth, while the mover side end of the magnetic plate extends in the width direction toward the permanent magnet row. The linear motor is disposed close to the mover. The sub teeth are formed at both ends of the tooth row in the moving direction,
The linear motor according to claim 1, wherein the magnetic plate is individually provided for each of the two sub teeth. The sub teeth are formed at both ends of the tooth row in the moving direction,
A stator side end of the magnetic plate in the width direction extends in the moving direction between the two sub teeth and contacts or approaches the two sub teeth, while the magnetic plate is movable. 2. The linear motor according to claim 1, wherein a child-side end portion extends from the permanent magnet row and is disposed close to the mover.   The linear motor according to any one of claims 1 to 3, wherein the stator side end portion of the magnetic plate is in contact with or close to a mover side end portion of the sub teeth in the width direction.   The linear motor according to claim 1, wherein the magnetic plate is formed separately from the sub teeth.   The linear motor according to claim 1, wherein the magnetic plate is formed integrally with the sub teeth.   The linear motor according to claim 1, wherein the magnetic plate is disposed on the base surface of the base plate. The base plate is formed by molding a nonmagnetic material,
The linear motor according to any one of claims 1 to 5, wherein the magnetic plate is placed inside the base plate by being cast when the base plate is molded. 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 so that the moving direction is parallel to the vertical direction,
The component transfer apparatus, wherein the movable part of the linear motor is connected to the nozzle shaft.

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