JP2001339901A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor facilitating manufacturing and assembly of a stator by making the outer case simple in shape. SOLUTION: The motor is provided with a stator 1, having a coil bobbin provided with a wire winding portion which is wire wound round and having a terminal portion 22 mounting terminal pin to connect a wind start portion and a wind end portion of the winding and also protruding outward in a radial direction of the coil bobbin, and a rotor installed in this stator 1. A curled case 28, formed by rolling a flat metal sheet in a circumferential direction of the stator 1, is set from the outside of the winding of the stator 1. An space between 28a and 28b of both ends in a circumferential direction of this case 28 is made an opening portion. The terminal portion 22 is protruded from this opening portion, and also an opening angle of the opening portion is formed less than 1/2 (180 deg.) of the whole circumference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor, and more particularly to a motor case for covering a stator.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional stepping motor. The stator 51 of this stepping motor
Has a configuration in which a coil bobbin 61 around which a coil 61a is wound and a coil bobbin 62 around which a coil 62a is wound are arranged so as to overlap in the axial direction. An inner yoke 55 having pole teeth 55a and an inner yoke 56 having pole teeth 56a are arranged between the coil bobbins 61 and 62. An outer yoke 57 having polar teeth 57a and an outer yoke 58 having polar teeth 58a are disposed axially outside the coil bobbins 61, respectively. In addition,
The outer yoke 57 is formed so as to cover the outside of the coil 61a wound around the coil bobbin 61, and also serves as an outer case of the motor. In addition, the outer yoke 5
Numeral 8 is formed so as to cover the outside of the coil 62a wound around the coil bobbin 62, and also serves as an outer case of the motor. The rotor 52 has the above-described pole teeth 55a to 58 on the inner periphery of the stator 51 thus formed.
a. A cap 54 welded to an outer yoke 58 is disposed coaxially with the rotation center axis 53 of the rotor 52 on one end face of the stator 51 in the axial direction. A bearing 54 a is arranged inside the cap 54, and the bearing 54 a supports one end of the rotation center shaft 53.

FIG. 5 is an external view of the above-described stepping motor. As shown in FIG. 5, openings 57b and 58b are provided in outer yokes 57 and 58 which also serve as exterior cases. From the window formed by the cooperation of the two openings 57b and 58b, a terminal pin 63a tied to the winding start portion of the winding 61a, a terminal pin 63c tied to the winding end of the winding 61a, and A terminal pin 63b tied to the winding start portion of the wire 62a;
The terminal portion 63 is provided with the terminal pin 63d, which is entangled with the winding end portion thereof, standing and fixed at equal intervals.

[0004]

In the motor constructed as described above, the outer case covering the entire outside of the stator 51 is composed of the outer peripheral portion of the outer yoke 57 having the pole teeth 57a and the outer case having the pole teeth 58a. The outer peripheral portion of the yoke 58 is configured. As described above, the outer case has a complicated shape and is composed of two members vertically divided in the axial direction. In addition, openings 57b and 58b are formed at the joints of the outer yokes 57 and 58, respectively, and they need to be arranged in the axial direction while aligning them. For this reason, the outer case has a complicated mold for production and has poor assemblability.

An object of the present invention is to provide a motor that is easy to manufacture and easy to assemble into a stator by making the outer case simple.

[0006]

In order to achieve the above object, the present invention relates to a coil bobbin provided with a winding portion on which a winding is wound, and a winding start and end portion of the winding. A terminal having a terminal pin fixed vertically and projecting radially outward of the coil bobbin; and a rotor disposed inside the stator. A curling case formed by rolling the metal plate in the circumferential direction of the stator is fitted, and a portion between both ends in the circumferential direction of the curling case is an opening, and a terminal portion is projected from the opening,
The opening angle of the opening is formed to be less than 1/2 (180 degrees) with respect to the entire circumference. If the outer case of the motor is a curling case as described above, the manufacture is easy and the fitting is easy. In addition, since the opening of the curling case is formed to be less than 1/2 (180 degrees), it is easily held, for example, at the outer peripheral portion of the yoke when it is fitted. Therefore, it is also easy to fix to the yoke later by welding or the like.

Another aspect of the present invention provides a motor,
The coil bobbin has a winding portion in which the winding is wound in an axially overlapped arrangement, and a curling case is welded to an outer peripheral portion of a metal yoke arranged between both winding portions. At the same time, the opening angle of the opening is formed to be less than 1/3 (120 degrees) with respect to the entire circumference. in this way,
If the opening is narrowed to some extent and the curling case is welded to the yoke, a magnetic circuit is formed more effectively, and higher motor characteristics can be obtained.

[0008] Further, another invention provides, in addition to the above-described motor,
The opening angle of the opening is formed to be 1/6 (60 degrees) or more with respect to the entire circumference. In this way, the assemblability is ensured by keeping the opening partly wide to some extent. In addition, by keeping the opening partly wide to a certain extent, this shape, which is obtained by cutting off the outer peripheral portion of the motor case, contributes to reduction in thickness in the radial direction.

[0009]

Embodiments of the present invention will be described below. FIG. 1 is a sectional view showing an entire motor according to an embodiment of the present invention. FIG. 2 is an exploded perspective view mainly showing a stator portion which is a main part of the embodiment of the present invention. FIG. 3 is a sectional view taken along line III-III of FIG.

As shown in FIG. 1, a motor according to an embodiment of the present invention (this embodiment is constituted by a stepping motor, but is simply referred to as a motor here) is disposed opposite to the stator 1. And a U-shaped frame 3 fixed to one end face of the stator 1, and the rotation center axis 21 of the rotor 2 is
Is projected from one end face, and the projected tip end is supported by the frame 3.

The stator 1 has two coil portions 11, 12
Are arranged in the axial direction, and a rotor 2 is rotatably arranged inside the stator 1. Each of the coil sections 11 and 12 has an outer yoke 13 arranged axially outward in the overlapped state and an inner yoke 14 arranged adjacently in the overlapped state. Both yokes 13 and 14 are made of a magnetic metal member, and have pole teeth 15 provided on the inner peripheral side thereof so as to face the outer peripheral surface of the magnet portion 2 a of the rotor 2.

The above two sets of outer yoke 13 and inner yoke 1
4 is insert-molded together with a coil bobbin 18 for winding the windings 16 and 17. Coil bobbin 1
Numeral 8 is made of a resin member.
The winding portions 19 and 20 for winding the windings 6 and 17 are arranged in an overlapping manner in the axial direction, and a hole 24 surrounding the periphery of the rotor 2 is provided in the inner peripheral portion. In addition, the above-mentioned pole teeth 15
In the hole 24, the surface thereof is exposed to the inside of the hole, and faces the magnet portion 2a of the rotor 2 described later.

At the edge of the hole 24, there is formed an upright cylindrical portion 23 which extends to the left in FIG. 1 and enters into an insertion hole 31a of the frame 3 described later. The upright cylindrical portion 23 is formed integrally with the coil bobbin 18 described above. The winding part 1 of the coil bobbin 18
The winding start portion of the winding 16 wound around the terminal 9 is a terminal portion 2
2 are entangled with the terminal pins 22a provided upright. The winding end of the winding 16 is entangled with a terminal pin 22c provided upright on the terminal portion 22. On the other hand, the winding start portion of the winding wire 17 wound around the winding portion 20 of the coil bobbin 18 is entangled with a terminal pin 22 b erected on the terminal portion 22. The winding end of the winding 17 is entangled with a terminal pin 22 d provided upright on the terminal portion 22. The terminal portion 22, on which the four terminal pins 22a to 22d are erected and fixed, is formed integrally with the coil bobbin 18 and protrudes outward in the radial direction of the coil bobbin 18.

Further, the stator 1 has a cap portion 25 extending rightward in FIG. The cap portion 25 has a circular hole 25 a for supporting a bearing 41 that supports the rear end (the right end in FIG. 1) of the rotation center shaft 21 of the rotor 2 after the rotor 2 is inserted into the stator 1. have. At the time of assembly, the hole 25a serves as an entrance for inserting the rotor 2 into the interior of the stator 1. The cap portion 25 thus configured is formed integrally with the above-described coil bobbin 18.
“a” is a series of holes that are continuous with the hole 24 described above.

Further, after the bearing 41 is fitted into the hole 25a of the cap portion 25, the cap portion 25 comes into contact with the rear end portion of the bearing 41 so that the bearing 41 is mounted on the frame 3.
A spring pressing cap member 43 provided with a spring biasing to the side is fitted. The spring pressing cap member 43 constantly urges the bearing 41 toward the frame 3 to urge the rotor 2 toward the metal frame 3 and the rotation center shaft 21 to the other bearing (the frame 3 side). Bearing) 4
2 to stabilize the rotation of the rotor 2.

The two coil portions 11 and 12 of the stator 1
, That is, from outside the windings 16 and 17 wound around the coil bobbin 18, a flat metal plate is
A curling case 28 formed by being rolled in the circumferential direction is fitted. When inserting this, the curling case 2
8 is fitted so that both ends 28a and 28b in the circumferential direction sandwich the terminal portion 22 described above.
28b are in contact with both sides of the terminal portion 22, respectively. That is, both ends 2 of the curling case 28
The portion between 8a and 28b is an opening, from which the terminal 22 protrudes. The curling case 28 thus formed has an opening angle of 1/4 (90 degrees) with respect to the entire circumference, and is formed by an arc of about 270 degrees.

In this embodiment, the curling case 28 is formed by an arc of about 270 degrees. However, the curling case 28 must be formed by an arc exceeding at least 1/2 (180 degrees) of the entire circumference. is there. That is, the opening angle of the opening needs to be less than 1/2 (180 degrees). This is because if the opening angle of the opening is 以上 or more of the entire circumference, the opening will fall off during mounting. If the opening angle of the opening is less than に 対 し て of the entire circumference, when the curling case 28 sandwiches the terminal portion 22 protruding from the stator 1, it is securely held outside the stator 1 without falling off. Is done. Therefore, for example, when the fixing of the curling case 28 to the stator 1 is further strengthened by welding,
The workability is also improved.

In the present embodiment, for the purpose of reducing magnetic flux leakage from the opening, the opening is 90
It is set at the time. However, since the motor according to the present embodiment is a micro motor in which the outer diameter of the stator 1 is set to about 6 mm, it is relatively unaffected by the deterioration of motor characteristics due to magnetic flux leakage from the opening. The opening is slightly wider than the embodiment, specifically, about 1/3 of the entire circumference, and the curling case 28 is welded to the outer peripheral portion of the inner yoke 14 by laser welding or the like to cover the casing over the entire circumference. It can be made almost the same as the motor characteristics of the described type of motor.

On the other hand, if the opening of the curling case 28 is made too narrow, it does not contribute to reduction in thickness in the radial direction. That is, there is not much difference from the stator whose entire circumference is covered by the casing. If the opening is widened, when the curling case 28 is assumed to have a circular shape, the opening has a shape that is cut off.
Thinner in the radial direction. Along with this, the amount of protrusion of the distal end portion of the terminal portion 22 protruding from the opening of the curling case 28 in the radial direction can be suppressed in the radial direction. As a result, the dimension of the entire motor in the radial direction on the terminal portion 22 side can be reduced.
From such a viewpoint, it is desirable that the opening of the curling case 28 be formed at most 1/6 (60 degrees) or more of the entire circumference.

As described above, the curling case 28 is formed by rolling a flat metal plate in the circumferential direction of the stator 1 and merely fitting the metal plate from the outside of the stator 1. In addition, the mold for molding does not have a complicated shape and is easy to manufacture. Also,
Since the cylinder has a shape in which a part of the cylinder is notched, it is possible to reduce the thickness in the radial direction as compared with the case where the casing is formed over the entire circumference of the stator.

In this embodiment, the curling case 28 is fixed to the outer peripheral portion of the inner yoke 14 by laser welding or the like as a countermeasure against the deterioration of motor characteristics due to magnetic flux leakage from the opening. The welding location is approximately 1 mm in the circumferential direction near the ends 28a and 28b (arrows A and C in FIG. 3) and the center of the arc (arrow B in FIG. 3).
There are three places at 10 degree intervals. This way,
The curling case 28 is firmly fixed to the stator 1, and the curling case 28 and the inner yoke 14 are joined to form the respective magnetic paths of the two coil portions 11 and 12 arranged in the axial direction. Are independent, and a smooth magnetic path flow can be formed in each case. Therefore, the magnetic path becomes more effective, and acts to compensate for the above-described deterioration in motor characteristics due to magnetic flux leakage.

A U-shaped frame 3 is fixed to the left end face in FIG. 1 of the stator 1 thus configured. The frame 3 is fixed to the stator 1 in advance before the rotor 2 is installed inside the stator 1. The frame 3 has a first flat portion 31 serving as a fixing surface to the stator 1, and a second flat portion 32 disposed to face the first flat portion 31. These two flat portions 31 and 32 are arranged so as to be orthogonal to the rotation center axis 21 of the rotor 2, and the two flat portions 31 and 32 are connected by a connection surface portion 33 parallel to the rotation center axis 21.

The first flat portion 31 serving as a fixing surface to the stator 1 is provided with an insertion hole 31a through which the rotation center shaft 21 of the rotor 2 is inserted. The upright cylindrical portion 23 of the stator 1 described above is inserted into the through hole 31a, and the upright cylindrical portion 2 is inserted into the through hole 31a.
The frame 3 is fixed to the stator 1 by inserting the frame 3 by press fitting or the like. A circular hole is formed in the second plane portion 32 of the frame 3, and a bearing 42 that supports the tip of the rotation center shaft 21 is fitted and fixed in the hole.

The rotor 2 is rotatably arranged in the hole 24 of the stator 1. The rotor 2 includes a magnet portion 2 a that is arranged to face the pole teeth 15 of the stator 1,
The magnet part 2 is located at the rotation center position of the magnet part 2a.
a has a rotation center shaft 21 made of metal fixed so that one side protrudes from the axial end surface of the shaft a. A lead screw portion 21a is formed on the outer periphery of a portion of the rotation center shaft 21 protruding from the magnet portion 2a. The lead screw portion 21a is screwed with a screw portion of a head member (not shown).
The head is movable in the left-right direction in FIG. 1 by rotating.

The rotor 2 has a lead screw 21
With the side on which a is formed as the head, the stator 1 is incorporated by being inserted into the hole 24 from the cap 25 side of the stator 1. That is, the tip of the rotation center shaft 21 of the rotor 2 on the side of the lead screw portion 21 a is
a, the lead screw portion 21a passes through the hole portion 24, and further passes through an upright cylindrical portion 23 provided upright at an edge of the hole portion 24. When the rotor 2 is inserted further into the stator 1 from this state, the rotation center shaft 21
Of the frame 3 hits a bearing 42 fitted in the second flat portion 32 of the frame 3.

Then, in this state, the hole 2
The bearing 41 is inserted into the bearing 5a, and the spring pressing cap member 4 is pressed while the spring is brought into contact with the rear end of the bearing 41.
The motor is assembled by putting 3 on the cap portion 25. When current is supplied to the windings 16 and 17 of the stator 1, the motor 2 assembled as described above rotates the rotor 2 around the rotation center axis 21.
While being biased to the side, the bearing is rotated by being supported by the two bearings 41 and 42, and the rotation causes the head member screwed to the lead screw portion 21a to move in the axial direction.

Although the above-described embodiment is an example of a preferred embodiment of the present invention, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. It is. For example, in the above embodiment,
The opening of the curling case 28 is set to about 90 degrees, and laser welding is performed at a total of three places near the both ends 28a and 28b and at the center. May be. Further, although the curling case 28 and the inner yoke 14 are welded, in addition to this, the curling case 28 and the outer yoke 13 may be welded. Further, the number of welding locations may be two at both ends excluding the center part instead of three in the circumferential direction, or may be four or more in the circumferential direction.

[0028]

As described above, according to the present invention, a curling case formed by rolling a flat metal plate in the circumferential direction of the stator from the outside of the winding of the stator is fitted, and both ends of the curling case in the circumferential direction are fitted. The intervening portion is defined as an opening, the terminal is projected from the opening, and the opening angle of the opening is formed to be less than 1/2 with respect to the entire circumference.
If the outer case of the motor is a curling case as described above, the manufacture is easy and the fitting is easy. In addition, since the opening of the curling case is formed to be less than に 対 し て of the entire circumference, it can be easily held, for example, at the outer peripheral portion of the yoke when it is fitted. Therefore, it is also easy to fix to the yoke later by welding or the like.

Further, a curling case is welded to the outer peripheral portion of a metal yoke disposed between both winding portions of the coil bobbin, and the opening angle of the opening is reduced by 1 / to the entire circumference.
By making it less than 3, the opening is narrowed to some extent,
Further, when the curling case is welded to the yoke, a magnetic circuit is more effectively formed, and higher motor characteristics can be obtained.

The opening angle of the opening is reduced to 1/6 (60
If the opening is widened to some extent by forming it above, this shape, as if the outer peripheral portion of the motor case has been scraped, contributes to the reduction in the radial thickness of the entire motor including the terminal protruding from this portion. Will be done.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an entire configuration of a motor according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a stator as a main part of the motor according to the embodiment of the present invention and a part of a frame fixed to the stator.

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is a cross-sectional view showing a stator which is a main part of a conventional motor.

FIG. 5 is an external view of a stator which is a main part of a conventional motor.

[Explanation of symbols]

 Reference Signs List 1 stator 2 rotor 13 outer yoke 14 inner yoke 15 pole teeth 16, 17 winding 18 coil bobbin 19, 20 winding part 22 terminal part 22a, 22b, 22c, 22d terminal pin 28 curling case 28a, 28b (of curling case) end Department

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference)

Claims (3)

[Claims] 1. A coil bobbin having a winding portion on which a winding is wound, and a terminal pin for tying the winding start and end portions of the winding are erected and fixed radially outside the coil bobbin. A stator having a terminal portion protruding from the stator, and a rotor disposed inside the stator, wherein a flat metal plate is formed by rolling a metal plate outside the windings of the stator in the circumferential direction of the stator. The curling case is fitted into the opening, and a portion between both ends in the circumferential direction of the curling case is formed as an opening. The terminal portion is protruded from the opening, and the opening angle of the opening is set to 1/2 ( (180 degrees). 2. The coil bobbin has a winding portion around which the winding is wound and arranged in an axial direction, and an outer periphery of a metal yoke disposed between the winding portions. While welding the curling case to the part,
The opening angle of the opening is 1/3 (120
The motor according to claim 1, wherein the motor is formed at a temperature less than (degree). 3. The opening angle of the opening is set to 1 with respect to the entire circumference.
3. The motor according to claim 2, wherein the motor is formed at / 6 (60 degrees) or more.