JP2005328621A - Stepping motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stepping motor which can improve inconvenience such as wire breakage, etc. in assembling work by suppressing the inclination of a terminal caused by the slip out or the play of a terminal or the distortion or deformation of a bobbin. <P>SOLUTION: This stepping motor is equipped with a rotor which has s magnet 4 magnetized in multipoles and a stator which is counterposed to the magnet. The stator has combtoothed yokes 5a, 7a, 5b, and 7b opposed to the magnet 4 and coil bobbins 8a and 8b caught between the yokes. The coil bobbin has extensions 16a and 16b where mounting holes 15a and 15b for attaching terminals 10a and 10b connected with a coil 18 are formed. The terminals 10a and 10b are provided with mounting bases 17a and 17b which have functions of preventing the slip out from the mounting holes at their one-side ends. The other end is projected outward from the extension via the mounting hole, and a heat-resistant insulating member 9 is interposed between the extension of the coil bobbin and the yoke. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ultra-compact stepping motor suitable for driving a lens of a camera or an optical pickup of a memory device.

A conventional stepping motor is constituted by inserting a rotor having a magnet magnetized in multiple poles and a stator unit from both sides in the axial direction of the rotor, and each stator unit is a pair of comb teeth facing the magnet. And a coil bobbin sandwiched between the pair of yokes (see, for example, Patent Document 1).
JP 2003-009497 A

  In the conventional stepping motor, as shown in FIG. 7 and FIG. 8, the terminal 110 is fixed by press-fitting to the heat-resistant resin bobbin 108. However, when soldering, looseness due to disconnection or looseness occurs. In addition, a coil 118 is wound around the terminal 110 and connected, but the connected portion 121 is exposed, so that the terminal 110 is inadvertently pressed when soldering the board or the FPC 122 or the like. Therefore, there is a risk of problems such as disconnection, and work improvements are desired. In FIG. 7, 101 is a rotating shaft, 102a and 102b are bearings, 103a, 103b and 111 are washers, 104 is a magnet, 105a, 105b, 107a and 107b are yokes, 112 is a case member, and 113 is a cover member. .

  As a countermeasure against the above-described omission and backlash, there is a method in which a terminal is integrally attached to a coil bobbin by insert molding. However, there is a face that cannot necessarily be said to be a good method because the mold becomes complicated and the manufacturing cost increases.

  As countermeasures against the disconnection at the time of soldering, the work connection has been improved so that the coil connection part of the terminal is lowered to the base side of the terminal as much as possible so that the coil does not shift to the tip end side of the terminal. It was not possible to cope with it enough.

  Further, the thin portions 108a and 108b extended from the coil bobbin for terminal attachment are warped or deformed by molding distortion, and the terminal fixed to the bobbin is thereby tilted. There was a problem.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to suppress the disconnection and backlash of the terminal, the inclination of the terminal due to the distortion and deformation of the bobbin, etc. It is to provide a stepping motor that can improve inconvenience.

  In order to solve the above-described problems and achieve the object, a stepping motor according to the present invention is a stepping motor including a rotor having a magnet 4 magnetized in multiple poles and a stator disposed to face the magnet 4. The stator includes comb-shaped yokes 5 a, 7 a, 5 b, 7 b facing the magnet 4, and coil bobbins 8 a, 8 b sandwiched between the yokes, and the coil bobbins are connected to the coil 18. Mounting terminals 15a and 15b having mounting holes 15a and 15b for mounting the terminals 10a and 10b to be mounted, and the terminals 10a and 10b having a function of preventing the terminals 10a and 10b from coming off from the mounting holes. Bases 17a and 17b are provided, and the other end protrudes outward from the extension through the mounting hole, and the extension of the coil bobbin and the yaw Characterized in that by interposing a heat-resistant insulating member 9 between.

  Further, in the above configuration, the insulating member is integrally formed with a first thick portion 9a interposed between the yoke and a bottom surface portion of the extending portion, and the first thick portion is provided as the extending portion. It is extended to the part in which the attachment base part of the said terminal exists in a part, The removal of the said terminal and a deformation | transformation of the said extension part are controlled.

  Further, in the above configuration, the insulating member is integrally formed with a second thick portion 9b that forms a gap S in a portion of the upper surface portion of the extending portion where the terminal exists, and the terminal 10 and the coil 18 are connected to each other. The part 21 exists in the said clearance gap S, It is characterized by the above-mentioned.

  As described above, according to the present invention, a heat-resistant insulating member is interposed between the coil bobbin extending portion and the yoke, thereby preventing the coil bobbin from coming off without insert molding the terminal pin. .

  Further, even when an external force is applied in the direction in which the terminal is pushed in, it is possible to prevent the terminal from coming out and coming into contact with the yoke and causing a short circuit.

  Further, it is possible to suppress the inclination of the terminal due to the distortion and deformation of the coil bobbin, and to improve the inconvenience such as the disconnection of the coil during the assembly work.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention (referred to as an embodiment, hereinafter the same) will be described below with reference to the accompanying drawings.

  The embodiment described below is an example as means for realizing the present invention, and the present invention can be applied to a modified or modified embodiment described below without departing from the spirit of the present invention.

  1 is an exploded perspective view showing a stepping motor according to an embodiment of the present invention, FIG. 2 is a perspective view showing an internal configuration of a case member in the stepping motor of FIG. 1, and FIG. 3 is a ZZ ′ cross section of FIG. 4 is a cross-sectional view of the main part of FIG. 3, FIG. 5 is a perspective view of a coil bobbin of the stepping motor of FIG. 1, and FIG. 6 is a perspective view showing a modification of the terminal.

  As shown in FIGS. 1 to 6, the PM type stepping motor of the present embodiment has a cylindrical magnet (permanent magnet) 4 magnetized with multiple poles (eight poles in the radial direction) having a central axis L. A rotor (rotor) is configured by being fixed to a rotating shaft 1 that passes therethrough. One end 1a of the rotating shaft 1 is pivotally supported by a cylindrical case member 12 via a bearing 2a. Further, the other end 1b of the rotating shaft 1 is pivotally supported by a cover member 13 attached to the case member 12 via a bearing 2b. The cover member 13 closes the opening end of the case member 12 in the axial direction. The case member 12 is formed by processing a metal as a non-magnetic material or molding a resin, and the bearing 2a is fixed to the case member 12 by press-fitting or the like. Similarly to the case member 12, the cover member 13 is also formed by processing or molding a nonmagnetic material, and the bearing 2 b is fixed to the cover member 13 by press-fitting or the like.

  A stator (stator) provided to face the magnet 4 is housed inside the case member 12 and is inserted along the axial direction from the one end 1a side of the rotating shaft 1. To 7 a and second stators 5 b to 7 b inserted along the axial direction from the other end 1 b side of the rotating shaft 1 are arranged coaxially with the rotating shaft 1.

  The first stator has first and second yokes 5a and 7a (referred to as a first yoke pair) having comb-like portions facing the magnetized outer periphery of the magnet 4, and a pair of these. And a coil bobbin 8a sandwiched between the first and second yokes 5a and 7a. The comb-like portions of the first and second yokes 5a and 7a are adjacent to each other alternately.

  A cylindrical shaft 7c projects from the second yoke 7a, and is positioned so as to be coaxial with the rotating shaft 1 by inserting one end 1a of the rotating shaft 1 into the inner peripheral surface of the cylindrical shaft 7c. The Further, the first yoke 5a and the coil bobbin 8a are inserted into the outer peripheral surface of the cylindrical shaft 7c so as to be positioned coaxially with the rotary shaft 1.

  Similarly to the first stator, the second stator also has third and fourth yokes 5b and 7b (referred to as a second yoke pair) having comb-like portions facing the magnet 4, and these. A coil bobbin 8b sandwiched between the pair of third and fourth yokes 5b and 7b. The comb-like portions of the third and fourth yokes 5b and 7b are also adjacent to each other.

  The second yoke 7b is also formed with a cylindrical shaft 7c projecting, and the other end 1b of the rotating shaft 1 is inserted into the inner peripheral surface of the cylindrical shaft 7c so as to be coaxial with the rotating shaft 1. Is done. Further, the third yoke 5b and the coil bobbin 8b are inserted into the outer peripheral surface of the cylindrical shaft 7c so as to be positioned coaxially with the rotary shaft 1.

  The first yoke pair 5a, 7a and the second yoke pair 5b, 7b are arranged along the axial direction from the one end 1a side and the other end 1b side of the rotary shaft 1 so as to cover the outer periphery of the magnet 4, respectively. Each inserted. The first yoke pair 5a, 7a and the second yoke pair 5b, 7b are arranged symmetrically so as to face each other through the washer 11 at the axial center of the rotating shaft 1. The ring-shaped washer 11 has a function of dividing each magnetic circuit of the first yoke pair and the second yoke pair. Also, washers 3 are arranged at both end portions 1a and 1b of the rotary shaft 1 so that both end surfaces of the magnet 4 and the second and fourth yokes 7a and 7b do not slide directly.

  Each of the coil bobbins 8a and 8b formed from a heat-resistant resin is provided with bobbin bodies 6a and 6b around which the coil 18 is wound, and extending portions 16a and 16b extending from the bobbin bodies 6a and 6b. Attachment holes 15a and 15b for attaching terminals 10a and 10b electrically connected to the coil 18 are formed in the extended portions 16a and 16b. Each extending portion 16a, 16b is provided with, for example, two terminals 10a, 10b and two penetrating mounting holes 15a, 15b for inserting them. Each terminal 10a, 10b has a T-shaped outer shape as a whole provided with attachment bases 17a, 17b having a function of preventing the attachment holes 15a, 15b from coming off from one end thereof. The other ends of the terminals 10a and 10b are inserted into the mounting holes 15a and 15b from the central axis side of the coil bobbins 8a and 8b, and are press-fitted so as to protrude outward from the mounting holes 15a and 15b of the extending portions 16a and 16b. And so on. Thereby, even if an external force that pulls the terminals 10a and 10b toward the outside of the coil bobbins 8a and 8b is applied, the terminals 10a and 10b are not easily detached. Note that the terminal may have an L shape in addition to the T shape (see FIG. 6).

  An insulating member 9 made of a heat resistant resin is interposed between the extending portions 16a, 16b of the coil bobbins 8a, 8b and the first and second yoke pairs. The insulating member 9 is interposed between the comb-like portions of the first and second yoke pairs located on the inner sides of the coil bobbins 8a and 8b and the bottom portions of the extending portions 16a and 16b. The thick portion 9a is integrally formed. A stepped portion 16c notched in a step shape is partially formed on the bottom surface portion of each extending portion 16a, 16b so that a gap is formed between each pair of yokes. The thick portion 9a extends to the portion where the mounting base portions 17a and 17b of the terminals 10a and 10b exist in the stepped portion 16c of the extending portions 16a and 16b, and the extension of the extending portions 16a and 16b is prevented. To prevent.

  Further, the insulating member 9 is integrally provided with a second thick portion 9b that forms a gap S in a portion where the terminals 10a and 10b exist between the lower surface of the substrate and the FPC 22 and the upper surface portions of the extending portions 16a and 16b. The connection portions 21 between the terminals 10a and 10b and the coil 18 exist in the gap S.

  In addition, the outermost diameter part of each comb-tooth shaped part of the first and second yoke pairs is guided by the inner wall surface of the case member 12, and the cover member 13 is fixed by welding or the like.

  According to the above configuration, the first thick portion 9a of the insulating member 9 is interposed between the bottom surface portions of the extending portions 16a and 16b of the coil bobbins 8a and 8b and the outer surface portions of the first and second yoke pairs. Therefore, even when an external force is applied in the direction in which the terminals 10a and 10b are pushed, it is possible to prevent the terminals 10a and 10b from coming out and coming into contact with the first and second yoke pairs and short-circuiting.

  Further, the second thick portion 9b of the insulating member 9 is interposed so as to form a gap S between the lower surface of the substrate or the FPC 22 and the upper surface portion of each extending portion 16a, 16b, and the terminals 10a, 10b Since the connection portion 21 of the coil 18 exists in the gap S, an inadvertent force is not applied to the connection portion between the terminal and the coil 18 when soldering the substrate or the FPC 22 or the like, so that the disconnection of the coil 18 can be prevented. .

  The present invention is not limited to a stepping motor, and can be applied to various fields where miniaturization of the motor is required.

It is a perspective view which decomposes | disassembles and shows the stepping motor of embodiment which concerns on this invention. It is a perspective view which shows the structure inside the case member in the stepping motor of FIG. It is Z-Z 'sectional drawing of FIG. It is principal part sectional drawing of FIG. It is a perspective view of the coil bobbin of the stepping motor of FIG. It is a perspective view which shows the modification of a terminal. It is sectional drawing of the stepping motor of a prior art example. It is principal part sectional drawing of the stepping motor of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating shaft 2a, 2b Bearing 3a, 3b, 11 Washer 4 Magnet 5a 1st yoke 5b 3rd yoke 6a, 6b Bobbin main body 7a 2nd yoke 7b 4th yoke 8a, 8b Coil bobbin 9 Insulating member 9a 1st Thick part 9b Second thick part 10a, 10b Terminal 12 Case member 13 Cover member 15a, 15b Attachment hole 16a, 16b Extension part 16c Step part 17a, 17b Attachment base 18 Coil 21 Coil connection part S Gap 22 Substrate And FPC

Claims (3)

A stepping motor comprising a rotor having a magnet magnetized in multiple poles, and a stator arranged opposite to the magnet,
The stator has a comb-shaped yoke facing the magnet, and a coil bobbin sandwiched between the yokes,
The coil bobbin has an extending portion in which an attachment hole for attaching a terminal connected to the coil is formed,
The terminal is provided with an attachment base portion having a function of preventing the terminal from being detached from the attachment hole, and the other end portion protrudes outward from the extension portion through the attachment hole,
A stepping motor comprising a heat-resistant insulating member interposed between the coil bobbin extending portion and the yoke. The insulating member is integrally formed with a first thick portion interposed between the yoke and a bottom surface portion of the extended portion, and the first thick portion is an attachment base portion of the terminal in the extended portion. 2. The stepping motor according to claim 1, wherein the stepping motor extends to a portion where the terminal exists and restricts the disconnection of the terminal and the deformation of the extending portion. In the insulating member, a second thick portion that forms a gap is formed integrally with a portion of the upper surface portion of the extending portion where the terminal exists, and a connection portion between the terminal and the coil exists in the gap. The stepping motor according to claim 1 or 2, characterized by the above.

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