JP2006191724A - Small stepping motor and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small stepping motor equipped with a terminal block applicable for further reduction in motor diameter by improving the shape and forming method of the terminal block. <P>SOLUTION: The small stepping motor 1 comprises a rotor 10 consisting of a permanent magnet having a plurality of poles, and a stator 20 (phase A stator 31A and phase B stator 31B) including a coil bobbin 25 and a coil 29 arranged on the outer circumferential region of the rotor 10. Furthermore, in the outer circumferential region of the adjoining portion 27 of two sets of stators 31A and 31B, a terminal base 50 is fixed to the bobbin 25 to cover the end of the coil 29. At a part of the outer surface of the terminal base 50 covering the coil 29, a terminal pin 51 for binding the start or end of coil winding is planted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a small stepping motor and a manufacturing method thereof. More particularly, the present invention relates to a motor having an improved connection structure for coil winding terminals in a small stepping motor having an outer diameter φ of 6 mm or less, and a manufacturing method thereof.

First, the structure of a conventional small stepping motor will be described.
3A and 3B are diagrams showing the structure of a positioning device using a conventional small stepping motor. FIG. 3A is a plan view, FIG. 3B is a front view, and FIG. 3C is a stepping motor. It is a cross-sectional view.
The positioning device 301 includes a stepping motor 201 and a lead screw 303 that is rotationally driven by the motor. As shown in FIG. 3C, the stepping motor 201 includes a rotor 210 made of permanent magnets and two stators 220 arranged in the outer peripheral area of the rotor 210. An extension shaft 303 a of a lead screw 303 is fixed to the shaft core of the rotor 210. The end of the extension shaft 303a is rotatably supported by the motor end bearing 305. On the other hand, the shaft end of the lead screw 303 on the side opposite to the motor is rotatably supported by a bearing 305 at the end of the base 101 of the positioning device 301. Thereby, the lead screw 303 and the rotor 210 are supported in the stator 220 so as to be rotatable around the motor shaft.

The structure of the stator 220 will be described.
The stator 220 includes an A-phase stator 231 </ b> A and a B-phase stator 231 </ b> B disposed in a cylindrical outer yoke 221. Each of the A-phase stator 231A and the B-phase stator 231B is a combination of two sets of claw pole type stator cores so that the pole teeth mesh with each other. The A-phase stator 231 </ b> A and the B-phase stator 231 </ b> B are arranged side by side in the motor shaft direction and are integrally fixed by a coil bobbin 225. The coil bobbin 225 is molded so as to cover the outer peripheral surfaces of the stators 231A and 231B and to be filled between the pole teeth.

  On the outer peripheral surface of the coil bobbin 225, concave portions having a U-shaped cross section are formed on both sides of the adjacent portion 227 of the A-phase stator 231A and the B-phase stator 231B. The stator adjacent portion 227 protrudes in a flange shape in the outer peripheral direction. In each of the aforementioned recesses, a winding is wound to form coils 229A and 229B. Each coil 229 is insulated from the A-phase stator 231A and the B-phase stator 231B by a coil bobbin 225.

  As shown in the lower side of FIG. 3C, the coil bobbin 225 is formed with a terminal block 250 protruding from the stator adjacent portion 227 to the outside in the radial direction of the motor. The terminal block 250 is integrally provided when the coil bobbin 225 is formed. As shown in FIG. 3B, the terminal block 250 has a strip shape in which the planar shape is horizontally long (short in the axial direction of the motor and long in the circumferential direction), and the axial length is the axis of the stator adjacent portion 227. It is slightly larger than the length in the direction and does not cover the ends of the coils 229 on both sides of the adjacent portion 227. The terminal block 250 protrudes from a window 222 formed in the outer yoke 221.

  Four terminal pins 251 for feeding power to the coil are implanted on the upper surface of the terminal block 250. As shown in FIG. 3B, the terminal pins 251 are arranged in a staggered manner in the longitudinal direction of the strip-shaped terminal block 250. As an example, the distance between the terminal pins 251 in the motor axis direction is 0.45 mm, the distance in the circumferential direction is 1.2 mm, and the height of the terminal pins 251 is 1.3 mm. Then, the terminal pin 251a shown in the uppermost part of FIG. 3B has the end of the winding of the coil 229B of the B-phase stator 231B entangled, and the terminal pin 251b below it has the winding of the coil 229A of the A-phase stator 231A. The beginning of the line is tied. Then, the lower end of the coil 229B of the B-phase stator 231B is entangled with the terminal pin 251c, and the end of the coil 229A of the A-phase stator 231A is entangled with the lower terminal pin 251d. Yes.

In order to set the outer diameter φ of the motor 201 having the terminal block 250 having such a shape to 6 mm or less, there are the following problems.
(1) When connecting flexible substrates, the interval between adjacent terminal pins 251 needs to be about 1.2 mm. This is to prevent short-circuiting between adjacent point solders when connecting a feeder line (such as a flexible substrate) to the terminal pins. However, if the motor is downsized, the terminal pins 251 cannot be arranged in a staggered manner with a sufficient interval.
(2) Generally, the terminal block 250 must be formed on the motor radial direction outer side of the stator adjacent portion 227 (recesses (coil end portions) on both sides in the motor axial direction of the stator adjacent portion 227). Can not be put on). This is because when the coil bobbin 225 is formed, it is necessary to secure a drawing path for the mold used for forming, and when the coil is wound, if there is a terminal block above the winding space (recess), the winding This is because work cannot be performed. Further, in the stator adjacent portion 227, in order to ensure insulation between the terminal pin 251 implanted in the terminal block 250 and the stator 231A, 231B, the lower end (root) of the terminal pin 251 and the stator adjacent portion 227 It is necessary to open a predetermined interval (for example, 0.2 mm). Therefore, the height of the terminal block 250 becomes high, and the terminal block 250 protrudes considerably in the motor outer diameter direction.
(3) Further, in order to prevent the terminal pin 251 from falling, if the insert depth of the pin into the terminal block 250 is increased, the height of the terminal block 250 is increased. As an example, the height from the motor axial direction center to the terminal block upper surface is 3.95 mm, and the height from the motor outer peripheral surface to the terminal block upper surface is 0.7 mm.

  For the reasons described above, it is extremely difficult to further reduce the size of the motor while maintaining the terminal block of the current shape, and it is essential to fundamentally change the structure of the terminal block.

  In addition, the following are disclosed about the terminal block of a small stepping motor (refer patent document 1 and patent document 2).

JP-A-8-289528 JP 2003-70224 A

In the stepping motor of FIG. 5 of Patent Document 1, terminal portions 5p and 6p projecting in the radial direction are provided on the casings 5h and 6h of the coil bobbins 5 and 6, and the terminals 5z and 6z are erected on the terminal portions.
In the stepping motor shown in FIG. 2 of Patent Document 2, a terminal 14 is driven into a terminal pedestal portion 13b that extends a flange portion 13a of a bobbin 13 and protrudes outward from the motor. And the resin part 15 is formed between the terminal base parts of each bobbin (refer FIG. 2).
In any of the patent documents, the terminal block is formed integrally with the coil bobbin and is formed so as to protrude in the radial direction of the motor. The terminal block is not provided so as to cover (overhang) the coil.

  The present invention has been made in view of the above problems, and by improving the shape and forming method of the terminal block, a small stepping motor having a terminal block that can be applied to further miniaturization of the motor diameter, and its An object is to provide a manufacturing method.

  A small stepping motor of the present invention is a small stepping motor comprising a rotor made of a permanent magnet and having a plurality of magnetic poles, a casing (yoke), and a stator including a coil bobbin and a coil disposed in the outer peripheral area of the rotor. The coil includes two sets of coils arranged side by side in the direction of the rotation axis of the rotor, and a terminal for connecting a starting end and a terminal end of the windings of the two sets of coils and a power supply line, A terminal base provided so as to cover the end of the coil in the outer peripheral area of adjacent portions of the two sets of coils, and two on the outer surface of the terminal base and covering the coil And terminal pins planted one by one.

By forming the terminal base separately from the coil bobbin without forming the terminal base integrally with the coil bobbin, the terminal base is provided in a wide range so as to cover the end portions of each coil with the adjacent portions of the two sets of coils sandwiched therebetween. be able to. And the space | interval between terminal pins can be taken wide by implanting a terminal pin in the part which covers on these coil edge parts. Therefore, even if the motor is downsized (for example, the outer diameter φ is 6 mm or less), an appropriate interval (for example, 1.2 mm or less) can be secured between the terminal pins. By providing appropriate spacing between terminal pins in this way, coil windings can be easily connected (feeding solder, etc.) to power supply lines (flexible board wiring, etc.), and short circuit prevention between adjacent solder spots is ensured. it can.
The terminal base can be attached to the coil bobbin by concavo-convex fitting or welding after the coil is formed.

  In the present invention, it is preferable that a dummy pin is provided between the two adjacent sets of coils for binding the start end and / or end of the winding of the coil.

  After the coil is wound, the beginning and / or end of the coil winding is temporarily entangled with the dummy pin. For example, the dummy pin can be provided on the outer surface of the coil bobbin between two adjacent sets of coils. And after winding and winding and forming a coil, after attaching a terminal base, the edge part of the coil | winding of each coil is removed from a dummy pin, and it binds to the terminal pin of a terminal base. Thus, even when the terminal base is provided, the coil winding end portion can be easily processed.

  In this invention, it is preferable that the said coil bobbin has a part which protrudes in the shape of a flange between the two said adjacent sets of coils, and the said terminal base is latched by this flange-shaped part.

  The terminal base can be attached to the stator by a simple method by providing a coil bobbin between two adjacent coils in a flange shape and providing an uneven fitting portion between the upper surface and the lower surface of the terminal base.

  In the present invention, it is preferable that the coil bobbin is made of a non-heat resistant grade resin material such as an acetal copolymer, and the terminal base is made of a heat resistant grade resin material such as a liquid crystal polymer.

  In the conventional terminal structure as shown in FIG. 3, since the winding and the flexible substrate are soldered to the terminal portion, the terminal block (bobbin) needs to be made of a heat-resistant grade resin material. However, since the terminal base and the bobbin are separated from each other in the present invention, only the terminal base is manufactured from a heat-resistant resin material, and the bobbin is manufactured from a low-cost resin material.

  Another small stepping motor according to the present invention includes a rotor having a plurality of magnetic poles from a permanent magnet, a casing (yoke), and a stator including a coil bobbin and a coil disposed in an outer peripheral area of the rotor. In the stepping motor, two sets of the coils are provided side by side in the rotation axis direction of the rotor, and the start and end of the windings of the two sets of coils are adjacent to the adjacent portions of the two sets of coils. It is characterized in that it is connected to the terminal of a circuit board (flexible board or the like) in the outer peripheral area and the part covering the end of the coil.

  The shape of the motor connection part (terminal base part) of the circuit board is formed so as to cover the ends of each coil with the adjacent parts of the two sets of coils in between, and the start and end of the coil windings are connected to the circuit. Connect directly to the end of the board by soldering. This eliminates the need for a terminal base and terminal pins, and eliminates the dimensional constraints of the stepping motor associated with the dimensional restrictions on those components.

  A manufacturing method of a small stepping motor according to the present invention includes a rotor made of a permanent magnet and having a plurality of magnetic poles, a casing (yoke), and a stator including a coil bobbin and a coil disposed in an outer peripheral area of the rotor. A method for manufacturing a small stepping motor, in which two sets of stators are arranged side by side in the rotational axis direction of the rotor, and a coil bobbin is formed on the outer peripheral portion of the stator by injection molding. A dummy pin for temporarily tangling the start and / or end of the winding of the coil is simultaneously formed in a portion between adjacent sets of stators, and the coil bobbins in the outer peripheral areas of the two sets of stators are simultaneously formed. Winding is wound around the outer periphery to form two sets of coils. At this time, the starting end and / or the end of the winding is tied to the dummy pin. A terminal base covering the end of each coil is provided in the outer peripheral area of the adjacent portion of the two sets of coils, wherein the terminal base is connected to the start and end of the winding of the coil and the feeder line 2 terminals are planted in a portion covering the end of each coil adjacent to the two sets of coils, and the coil winding start end wound around the dummy pin and The terminal is re-entangled with the terminal of the terminal base.

  A small stepping motor mounting method according to the present invention includes a rotor made of a permanent magnet and having a plurality of magnetic poles, a casing (yoke), and a stator including a coil bobbin and a coil disposed in an outer peripheral area of the rotor. A method for mounting a small stepping motor, wherein two sets of stators are arranged side by side in the direction of the rotation axis of the rotor, and a coil bobbin is formed on the outer peripheral portion of the stator by injection molding. A dummy pin for temporarily binding the start end and / or the end of the coil winding is simultaneously formed in a portion between two sets of stators adjacent to each other, and the coil bobbin in the outer peripheral area of each of the two sets of stators A coil is formed by winding a winding around the outer periphery of the wire, and at this time, the starting end and / or the end of the winding is tied to the dummy pin. A circuit board (flexible) is formed at a portion of the outer periphery of the portion where the two sets of coils are adjacent to each other on the end portion of each coil. It is characterized in that it is connected to a terminal of a substrate or the like.

  As is apparent from the above description, according to the present invention, by separating the terminal base from the coil bobbin, the distance between the terminal pins can be minimized and the terminal size can be reduced. Therefore, it is possible to provide a small stepping motor having a terminal block that can be applied to further miniaturization of the motor diameter and a manufacturing method thereof. Alternatively, by eliminating the terminal base and the terminal pins themselves, it is possible to provide a small stepping motor capable of directly connecting the flexible substrate to the motor and an attaching method thereof.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1A and 1B are diagrams showing a structure of a positioning device using a small stepping motor according to an embodiment of the present invention. FIG. 1A is a plan view, FIG. 1B is a front view, and FIG. C) is a cross-sectional view of the stepping motor, and FIG. 1D is an enlarged cross-section of a part of the stepping motor.
The positioning device 100 includes a stepping motor 1 and a lead screw 103 that is rotationally driven by the motor.

First, the structure of the stepping motor 1 will be described.
As shown in FIG. 1C, the stepping motor 1 includes a rotor 10 made of a permanent magnet and a stator 20 disposed in the outer peripheral area of the rotor. Furthermore, the terminal base 50 in which the terminal pin 51 for supplying electric power to a coil was erected was provided.

  The rotor 10 is made of, for example, a cylindrical neodymium magnet. A groove 11 extending in the circumferential direction is formed or cut at substantially the center of the outer peripheral surface of the rotor 10 in the motor axial direction. By this groove 11, the rotor 10 is divided into a magnet part 13A on one side of the groove and a magnet part 13B on the other side in the motor axial direction. Each magnet part 13 is magnetized so that it may become the same pitch as the number of teeth of the claw pole of the stator 20 mentioned later. As will be described later, an extension shaft 103a of the lead screw 103 is passed through and fixed to the rotor 10.

Next, the stator 20 will be described.
The stator 20 includes an A-phase stator 31A and a B-phase stator 31B disposed in a cylindrical outer yoke 21. Stator 31A, 31B consists of two stator cores, respectively. The stator core has a shape (claw pole type) in which a plurality of pole teeth protrude in the axial direction along the inner peripheral edge of the ring-shaped flange. Each of the stators 31A and 31B is a combination of the stator cores so that the pole teeth mesh with each other, and the cross section of the stator cores along the outer peripheral surface of the same pair by the two flanges of the stator core and the combined pole teeth. A U-shaped recess is formed.

A-phase stator 31A and B-phase stator 31B are arranged adjacent to each other in the motor axial direction. At this time, the flange of the A-phase stator 31A and the flange of the B-phase stator 31B are joined to form a portion extending in the outer peripheral direction into a flange shape extending in the circumferential direction (hereinafter referred to as a flange-shaped portion 27, FIG. (Shown below (C)). The A-phase stator 31A and the B-phase stator 31B are integrally fixed by a coil bobbin 25. The coil bobbin 25 is molded so as to cover the outer peripheral surface of each recess of the A-phase stator 31A and the B-phase stator 31B and the outer peripheral surface of the flange-shaped portion 27 and to fill between the pole teeth of each stator core. It is. As shown in FIG. 1C, the coil bobbin 25 covers the outer peripheral surface of each recess and the outer peripheral surface of the flange-like portion with a substantially constant thickness. That is, the terminal block (terminal block 250 in FIG. 3) protruding in the motor radial direction, which is present in the conventional small stepping motor, is not provided.
As the resin for the coil bobbin 25, it is not necessary to use a heat-resistant grade resin as in the past (details will be described later), and a low-cost resin (500 yen / kg) such as Duracon (acetal copolymer) can be used.

  Further, as shown in FIG. 1B, two dummy pins 41 are integrally formed on the outer surface of the flange-shaped portion 27 when the coil bobbin is formed. The dummy pins 41 are arranged at a predetermined interval in the circumferential direction. The dummy pin 41 will be described later in the description of the stepping motor manufacturing method.

  Windings are wound around the recesses of the A-phase stator 31A and the B-phase stator 31B to form coils 29A and 29B. Each coil 29 is insulated from the stators 31 </ b> A and 31 </ b> B by the coil bobbin 25. The starting end and the terminal end of the winding of each coil 29 are entangled with terminal pins 51 implanted in a terminal base 50 described later.

  The A-phase stator 31 </ b> A and the B-phase stator 31 </ b> B fixed side by side in the motor axial direction are arranged in a manner that fits into the outer peripheral yoke 21 on a concentric cylinder. A window 22 is formed in a part of the center of the outer yoke 21 in the motor axial direction. From this window 22, the flange-shaped portion 27 including the dummy pins 41 and a terminal base 50 described later are exposed.

Next, the terminal base 50 will be described.
The terminal base 50 is provided with terminal pins 51 for supplying power to the coil, and is attached to the flange-like portion 27 of the coil bobbin. As shown in FIG. 1B, the base 50 has a rectangular plate shape that is long in the motor axial direction, and is made of heat-resistant grade resin. As the heat resistant grade resin, liquid crystal polymer Vectra E130 or the like can be used.
As shown in FIG. 1B, in the longitudinal direction (motor shaft direction), the terminal base 50 covers the end portions of the coils 29A and 29B formed in the concave portions on both sides of the flange-shaped portion 27. Have such a length. Further, in the short direction (motor circumferential direction), the width is narrower than the interval between the dummy pins 41 provided on the flange-shaped portion 27.

  As shown in FIG. 1D, a groove 53 having a width substantially equal to the width of the flange-like portion 27 is formed on the lower surface of the terminal base 50 so as to extend in the short direction. The terminal base 50 is attached to the coil bobbin 25 by fitting the groove 53 and the flange-shaped portion 27 to an uneven shape. By providing such a groove 53, the protruding height of the terminal base 50 in the outward direction of the motor can be suppressed. At this time, the lower surface of the terminal base 50 substantially contacts the outer surface of the coil 29 wound around each recess, and the upper surface protrudes slightly from the window 22 of the outer yoke 21.

  In addition, the guide pin 43 is provided in the flange-shaped part 27 at the time of coil bobbin shaping | molding. On the other hand, a locking portion 55 that engages with the guide pin 43 is provided on the lower surface of the terminal base 50. Then, the guide pin 43 is engaged with the engaging portion 55 so that the terminal base 50 is attached to the coil bobbin 25.

  Four terminal pins 51 are planted on the upper surface of the terminal base 50. Each terminal pin 51 has two terminal pins 51a and 51b arranged on one side in the motor axial direction with the flange-shaped portion 27 in between in the longitudinal direction of the terminal base 50, and the other two terminal pins 51c, 51d is arranged on the opposite side. As an example, the distance between the terminal pins 51a and 51b and the terminal pins 51c and 51d in the motor shaft direction is 1.75 mm. In the motor circumferential direction, the distance between the terminal pins 51a and 51c and the terminal pins 51b and 51d is 1.2 mm.

  Thus, by making the terminal base 50 separate from the coil bobbin 25, the area of the terminal base 50 can be widened and the terminal pins 51 can be implanted at appropriate intervals. That is, since the terminal base 50 is not formed at the time of forming the coil bobbin 25, the terminal base 50 can be provided so as to cover the outer side of the concave end portion of each stator 31 (end portion of the coil 29). The terminal pin 51 can be planted in the part.

  In the conventional small stepping motor, since the terminal block protruding radially outward from the flange-shaped portion is provided integrally with the coil bobbin, the height from the motor central axis to the terminal block has been increased. However, in the present invention, the terminal base 50 may be projected from the flange-shaped portion 27 to the outside of the small-diameter coil 29, and the terminal pin 51 may be implanted in the projected portion. For this reason, the height from the motor central axis to the upper surface of the terminal base 50 can be reduced even if the insertion depth of the terminal pins 51 into the terminal base 50 or the press-fitting depth is the same as that of a conventional small stepping motor. In this example, even if the distance between the lower end (base) of the terminal pin 51 and the lower surface of the terminal base 50 is 0.2 mm, the height from the motor central axis to the upper surface of the terminal base 50 is about 3.1 mm. The height of the upper surface of the terminal base 50 can be made substantially equal to the diameter of the outer yoke 21.

  These terminal pins 51 are entangled with the start and end of each coil 29. In this example, the terminal pin 51a is entangled with the starting end of the coil 29A and the terminal pin 51b is entangled with the end of the coil 29A. Further, the starting end of the winding of the coil 29B is bound to the terminal pin 51c, and the terminal end of the winding of the coil 29B is bound to the terminal pin 51d.

Next, a method for manufacturing the stepping motor 1 will be described focusing on a method for manufacturing the stator. Description of the manufacturing method of the entire motor and the manufacturing method of the positioning device is omitted.
First, the A-phase stator 31A and the B-phase stator 31B are assembled by combining two pairs of claw pole type stator cores so that the pole teeth mesh with each other. At this time, a concave portion having a U-shaped cross section is formed along the outer peripheral surface of the assembly by the two flanges of each stator core and the combined pole teeth. At the same time, the flanges of both the stators 31 are joined to form a flange-like portion (flange-like portion 27) extending in the circumferential direction. The A-phase stator 31A and the B-phase stator 31B are arranged in the axial direction so that the resin covers the concave portions of the stators 31A and 31B and the outer peripheral surface of the flange-shaped portion 27 and is filled between the pole teeth of the stator core. Outsert molding is performed to form the coil bobbin 25. At this time, two dummy pins 41 and two guide projections 43 are also formed on the flange-shaped portion 27. The guide protrusion 43 has both a guide function for attaching the terminal base 50 and a coupling function.
Then, the windings of the coils 29A and 29B are wound around the recesses. At this time, since the terminal base 50 is not yet attached, there is a space above each recess, and does not hinder the winding work. The starting end of each winding of the coils 29A and 29B is temporarily tied to one dummy pin 41 and the end is temporarily tied to the other dummy pin 41. The starting end may be tied to a jig.

Next, the outer peripheral yoke 21 is assembled outside the A-phase stator 31A and the B-phase stator 31B fixed side by side in the motor axial direction. At this time, the dummy pin 41 is positioned so as to be exposed from the window 22 of the outer yoke 21.
Thereafter, the terminal base 50 is attached to the flange-shaped portion 27 exposed from the window 22. At this time, the flange-shaped portion 27 is fitted into the groove 53 of the terminal base 50, and the guide protrusion 43 of the flange-shaped portion 27 and the engaging portion 55 of the terminal base 50 are engaged, so that the terminal base 50 is connected to the coil bobbin 25. Attach to.

Then, the start and end of the windings of the coils 29 </ b> A and 29 </ b> B are removed from the dummy pin 41, and the coil 29 </ b> A and 29 </ b> B are entangled with the appropriate terminal pin 51 implanted in the terminal base 50. In general, the beginning and end of the winding are conducted to the terminal pin 51 on the terminal base 50 by soldering. For this reason, the terminal base 50 in which the terminal pins 51 are implanted needs to have a heat resistance grade. However, since the heat of the solder is not directly transmitted to the coil bobbin 25, the bobbin 25 can be made of a low-cost resin having no heat-resistant grade.
Thereby, the assembly of the stator 20 is completed. In this process, a process for attaching the terminal base 50 to the coil bobbin 25 is required as compared with the manufacturing process of the conventional stepping motor, and the process is increased by one process. However, a small stepping motor having an outer diameter φ of 6 mm or less can be realized.

Next, the structure of the positioning device of FIG. 1 will be described.
The positioning device 100 includes a small stepping motor 1, a base member 101, a lead screw 103, and the like. An extension portion 103 a of the lead screw 103 is fixed to pass through the shaft core of the rotor 10 of the stepping motor 1. The end of the extension 103a is rotatably supported by a bearing 105 at the motor end. On the other hand, the shaft end of the lead screw 103 on the non-motor side is rotatably supported by the base member 101 via a bearing 105. Thus, the rotor 10 and the lead screw 103 are supported in the stator 20 so as to be rotatable around the motor shaft.
The base member 101 has a screw hole 107 and a positioning hole 109 for attachment to a device in which the positioning device 100 is incorporated.

2A and 2B are diagrams showing the structure of a positioning device using a small stepping motor according to another aspect of the present invention. FIG. 1A is a plan view, FIG. 1B is a front view, and FIG. C) is a cross-sectional view of the stepping motor section.
The small stepping motor 1 of this example has substantially the same configuration as the small stepping motor of FIG. Parts having the same configuration and operation as those of the small stepping motor of FIG. 1 are denoted by the same reference numerals as those of FIG. Also in the manufacturing method, the description of the same steps as the manufacturing method of the stepping motor in FIG. 1 is omitted.
The small stepping motor 1 has the same structure as the small stepping motor 1 of FIG. 1 except that the terminal base 50 is not provided. The start and end of the coils 29A and 29B are directly connected to the terminal of the flexible substrate 70.

Hereinafter, a method for attaching the flexible substrate 70 will be described.
Four terminals 71 are formed on the motor connection portion (terminal base portion) 70 </ b> A of the flexible substrate 70. In the terminal base portion 70A, the width between the two distal ends 71a and 71b and the two proximal ends 71c and 71d is larger than the width of the flange-shaped portion 27 of the coil bobbin 25 of the stepping motor 1. wide. An engagement hole 73 that engages with the guide protrusion 43 formed on the flange-shaped portion 27 of the coil bobbin 25 is formed in a portion between the terminals of the terminal base portion 70A.

  Such a flexible substrate 70 is attached to the coil bobbin 25 by engaging the engagement hole 73 of the terminal base portion 70 </ b> A and the guide protrusion 43 of the flange-shaped portion 27. Then, the two terminals 71a and 71b on the distal end side cover the outside of the coil 29A, and the two terminals 71c and 71d on the proximal end side cover the outside of the coil 29B. Then, the start and end of the windings of the coils 29A and 29B are removed from the dummy pin 41 and soldered to each terminal 51 of the terminal base portion 70A.

  As described above, when the terminal base is not provided, the starting end and the terminal end of the coil winding can be connected to the terminal of the terminal base portion of the flexible substrate.

It is a figure which shows the structure of the positioning device using the small stepping motor which concerns on embodiment of this invention, FIG. 1 (A) is a top view, FIG.1 (B) is a front view, FIG.1 (C) is a stepping. FIG. 1D is an enlarged cross-sectional view of a part of the stepping motor. It is a figure which shows the structure of the positioning device which uses the small stepping motor based on the other aspect of this invention, FIG. 1 (A) is a top view, FIG.1 (B) is a front view, FIG.1 (C) is a stepping. It is a cross-sectional view of a motor part. It is a figure which shows the structure of the positioning device using the conventional small stepping motor, FIG. 3 (A) is a top view, FIG.3 (B) is a front view, FIG.3 (C) is a cross-sectional view of a stepping motor. is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stepping motor 10 Rotor 11 Groove 13 Magnet part 20 Stator 21 Outer periphery yoke 22 Window 25 Coil bobbin 27 Flange-like part 29 Coil 31 Stator 41 Dummy pin 43 Guide protrusion 50 Terminal base 51 Terminal pin 53 Groove 55 Locking part 100 Positioning device 103 Lead screw 105 Bearing 107 Mounting hole 109 Positioning hole

Claims (7)

A rotor made of a permanent magnet and having a plurality of magnetic poles;
A casing (yoke), and a stator including a coil bobbin and a coil, disposed in the outer peripheral area of the rotor;
A small stepping motor comprising:
Two sets of the coils are provided side by side in the rotation axis direction of the rotor,
Terminals for connecting the starting and terminating ends of the windings of the two sets of coils and the power supply line,
A terminal base provided so as to cover the end of the coil in the outer peripheral area of the adjacent portions of the two sets of coils;
Two terminal pins that are implanted on the outer surface of the terminal base and covering each part of the terminal base;
A small stepping motor characterized by comprising:   2. The small stepping motor according to claim 1, wherein a dummy pin is provided between the two adjacent sets of coils to tie the start end and / or end of the winding of the coil.   2. The small stepping according to claim 1, wherein the coil bobbin has a portion protruding in a flange shape between the two adjacent sets of coils, and the terminal base is locked to the flange-shaped portion. motor.   4. The small stepping motor according to claim 1, wherein the coil bobbin is made of a non-heat resistant grade resin material such as an acetal copolymer, and the terminal base is made of a heat resistant grade resin material such as a liquid crystal polymer. . A rotor made of a permanent magnet and having a plurality of magnetic poles;
A casing (yoke), and a stator including a coil bobbin and a coil, disposed in the outer peripheral area of the rotor;
A small stepping motor comprising:
Two sets of the coils are provided side by side in the rotation axis direction of the rotor,
The beginning and end of the windings of the two sets of coils are:
A small stepping motor characterized in that it is connected to a terminal of a circuit board (flexible board or the like) in an outer peripheral area of adjacent parts of the two sets of coils, and a part covering the end part of the coils . A manufacturing method of a small stepping motor comprising a rotor made of a permanent magnet and having a plurality of magnetic poles, a casing (yoke), and a stator including a coil bobbin and a coil disposed in the outer peripheral area of the rotor,
Two sets of stators are arranged side by side in the direction of the rotation axis of the rotor,
A coil bobbin is formed on the outer periphery of the stator by injection molding,
At this time, a dummy pin for temporarily tangling the start and / or end of the coil winding is simultaneously formed in a portion of the coil bobbin between the two sets of adjacent stators,
Two sets of coils are formed by winding a winding around the outer periphery of the coil bobbin in the outer peripheral area of each of the two sets of stators. At this time, the starting end and / or the end of the winding is tied to the dummy pin. ,
In the outer peripheral area of the portion where the two sets of coils are adjacent, a terminal base that covers the end of each coil is provided,
Here, two terminals for connecting the start and end of the winding of the coil and the power supply line to the terminal base are provided on a portion covering the end portion of each coil of the adjacent portion of the two sets of coils. Planted one by one,
A manufacturing method of a small stepping motor, wherein the starting end and the terminal end of the winding of the coil entangled with the dummy pin are entangled with the terminal of the terminal base. A small stepping motor mounting method comprising a rotor made of a permanent magnet and having a plurality of magnetic poles, a casing (yoke), and a stator including a coil bobbin and a coil, which are disposed in the outer peripheral area of the rotor,
Two sets of stators are arranged side by side in the direction of the rotation axis of the rotor,
A coil bobbin is formed on the outer periphery of the stator by injection molding,
At this time, a dummy pin for temporarily tangling the start and / or end of the coil winding is simultaneously formed in a portion of the coil bobbin between the two sets of adjacent stators,
A coil is formed by winding a winding around the outer periphery of the coil bobbin in the outer peripheral area of each of the two sets of stators. At this time, the starting end and / or the end of the winding is tied to the dummy pin,
A circuit board (flexible board) is formed in a portion of the outer periphery of the portion where the two sets of coils are adjacent to each other over the end portion of each coil. Etc.) is connected to the terminal of the small stepping motor.

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