JP2002305846A - Dc motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent breakage or distortion of an elastic stopping piece 4e provided at a magnet-fixing spring 4 by stably holding an interpole 5 by the magnet-fixing spring 4 and preventing the interpole 5 from moving. SOLUTION: The magnet-fixing spring 4 has a base bottom surface 4a and a pair of side surfaces 4b which are formed by folding an elastic metal plate in a roughly U-shape. The inside-diameter side edge parts of both the side surfaces 4b are folded inwardly, and an elastic protruding part 4g capable of generating elasticity is provided at a roughly central part of a folded piece 4d. The interpole 5 is inserted into the inner part of the magnet-fixing spring 4 and pressed to an outer periphery side by an elastic force received from the elastic protruding part 4g and is held between the protruding part and an outer diameter supporting part 4c provided on the base bottom surface 4a. The interpole 5 can stably be held, and a load applied to the elastic stopping piece 4e of the magnet-fixing spring 4 can be reduced, breakage or distortion of the elastic stopping piece 4e is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC motor having a plurality of permanent magnets as main magnetic poles and an auxiliary pole arranged between adjacent main magnetic poles, and more particularly to a magnet for fixing the main magnetic pole and the auxiliary pole simultaneously. It relates to the fixing member.

[0002]

2. Description of the Related Art As a conventional technique, there is a DC motor described in Japanese Patent Application Laid-Open No. 2000-261989. In this DC motor, an auxiliary pole is arranged between main magnetic poles adjacent in the circumferential direction, and the auxiliary pole is fixed together with the main magnetic pole by a magnet fixing member. As shown in FIG. 9A, the magnet fixing member 100 is provided by bending an elastic metal plate into a substantially U-shape, and has a supplementary electrode 200 (see FIG. 10) between the opposing side surfaces 110. A supplementary pole space 120 for placement is formed. Also on both sides
110 are bent inwardly so that the inner diameter side ends thereof face each other, and the axial end of the bent piece 130 is cut off from the side face 110 to be elastically deformable in the radial direction.
It is provided as.

As shown in FIG. 10A, the auxiliary pole 200 pushes the elastic locking piece 140 outward (downward in FIG. 10) and is inserted into the magnet fixing member 100 from the axial direction. FIG.
As shown in (b), it is arranged in the auxiliary pole space 120. The auxiliary pole 200 arranged in the auxiliary pole space 120 is
0 is prevented from moving in the axial direction by the locking portion 150 provided at the end of the auxiliary pole 200, and the outer diameter end face of the auxiliary pole 200 is fixed to the magnet fixing member.
100 is supported by a cut-and-raised piece 170 provided on an upper wall surface 160, and the inner diameter side end face of the auxiliary pole 200 is supported by a bent piece 130 to be positioned in the radial direction.

As shown in FIG. 9 (b), the elastic locking piece 140 provided on the bent piece 130 is
When the auxiliary pole 200 is not arranged in the
On the other hand, the end (locking portion 150) of the elastic locking piece 140 is slightly inclined upward in the figure. Therefore, when the auxiliary pole 200 is disposed in the auxiliary pole space 120, the elastic locking piece 140 becomes substantially flush with the bent piece 130, as shown in FIG. I do. This allows
The auxiliary pole 200 receives the elastic force from the elastic locking piece 140 and is urged upward in the figure, and the outer diameter end face of the auxiliary pole 200 is cut and raised.
, The movement in the radial direction is regulated.

[0005]

However, since the elastic locking piece 140 is opened outward when the auxiliary pole 200 is inserted from the axial direction, the elastic locking piece 140 has a certain length L in the axial direction (FIG. 9).
(B)). Therefore, the auxiliary pole space 12
In a state where the auxiliary pole 200 is disposed at 0, the elastic locking pieces 140
Is relatively small, and a pressing force that cannot reliably prevent the auxiliary pole 200 from moving in the radial direction cannot be obtained.
Therefore, the auxiliary pole is compensated by the armature rotational vibration, armature reaction, etc.
As a result, the elastic locking piece 140 may be deformed outward (inner side of the motor) and interfere with the armature.

Further, the elastic locking piece 140 may be stressed more than necessary due to the movement of the auxiliary pole 200, and the elastic locking piece 140 may be broken. The present invention has been made based on the above circumstances, and an object of the present invention is to provide a DC motor in which auxiliary poles are arranged between main magnetic poles via respective magnet fixing members, and the auxiliary poles are stably provided by the magnet fixing members. An object of the present invention is to prevent breakage or deformation of an elastic locking piece provided on a magnet fixing member by holding and preventing movement of an auxiliary pole.

[0007]

According to a first aspect of the present invention, a magnet fixing member is provided by bending a metal plate having elasticity into a substantially U-shape to provide a pair of side surfaces facing each other in a circumferential direction. A supplementary pole space for placing a supplementary pole between them is formed, and the inside ends of both sides are bent inward so as to oppose each other in the circumferential direction, and the axial end of the bent piece is cut off from the side. It is provided as an elastic locking piece that can be elastically deformed in the radial direction, and furthermore, an elastic projection portion that can generate elasticity is provided on a part of the bent piece, and the auxiliary pole pushes the elastic locking piece outward to open. Are inserted into the auxiliary pole space from the axial direction, and are pressed and held to the outer diameter side by the elastic force received from the elastic projection.

According to this structure, the auxiliary pole arranged in the auxiliary pole space is pressed toward the outer diameter side by receiving the elastic force of the elastic projection, so that the auxiliary pole can be prevented from rattling, and the auxiliary pole can be removed. Can be held stably. As a result, the load applied to the elastic locking piece to hold the auxiliary pole can be reduced, and the movement of the auxiliary pole due to armature rotational vibration, armature reaction, etc. can be prevented, so that the elastic locking piece is broken or deformed. And the interference between the elastic locking piece and the armature can be prevented.

(Means of Claim 2) In the DC motor according to claim 1, the elastic projection is provided by deforming a part of the bent piece into a convex shape. In this case, the elastic projections can be easily formed, and the elastic projections can be easily provided at a plurality of positions on the bent piece.

According to a third aspect of the present invention, in the DC motor according to the first or second aspect, the elastic locking pieces are provided on both sides in the axial direction of the bent pieces, respectively, and the elastic locking pieces have axial ends. The portion is provided with a locking portion that supports an axial end surface of the auxiliary pole disposed in the auxiliary pole space. Thus, the auxiliary pole can be prevented from moving in the axial direction, so that the auxiliary pole can be prevented from rattling, and the auxiliary pole can be held more stably.

According to a fourth aspect of the present invention, in the DC motor according to any one of the first to third aspects, the magnet fixing member supports the outer diameter end face of the auxiliary pole disposed in the auxiliary pole space at a plurality of locations. It has an outer diameter support. In this case, since the outer diameter side end face of the auxiliary pole can be supported at a plurality of locations by the outer diameter support portion,
As compared with the case where the auxiliary pole is received on the surface of the magnet fixing member, the play of the auxiliary pole can be reduced, and the auxiliary pole can be held more stably.

According to a fifth aspect of the present invention, in the DC motor according to the fourth aspect, the magnet fixing member has a base surface radially opposed to an outer end surface of the auxiliary pole disposed in the auxiliary pole space. The outer diameter support portion is provided by cutting and raising a part of the base surface toward the auxiliary pole space. In this case, the outer diameter support portion can be easily formed, and the number of the outer diameter support portions can be easily changed with respect to the base surface.

(Means of Claim 6) In the DC motor according to claim 4 or 5, the outer diameter support portion is formed by press working. In this case, the outer diameter support portion can be provided simultaneously with the molding of the magnet fixing member.

According to a seventh aspect of the present invention, in the DC motor according to the sixth aspect, a radial distance between an outer diameter side end surface of the auxiliary pole disposed in the auxiliary pole space and a base surface is equal to an outer diameter support portion. Is set smaller than the length of. In this configuration, the radial distance between the outer diameter side end surface of the auxiliary pole and the base surface can be reduced, so that the radial height of the entire magnet fixing member can be designed to be low.

(Means of Claim 8) In the DC motor according to claim 6 or 7, the outer diameter support portion is arranged such that a substantially central portion in the longitudinal direction thereof comes into contact with the outer diameter side end face of the auxiliary pole. Is press-formed into a substantially arc shape or a substantially V-shape. According to this configuration, even if the radial distance of the space generated between the outer diameter side end surface of the auxiliary pole and the base surface is reduced, it is not necessary to shorten the outer diameter support portion accordingly. The outer diameter support portion can be easily provided by press molding. That is, the length of the outer diameter support portion can be set to a length that allows press forming.

[0016]

Next, an embodiment of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a perspective view of a magnet fixing spring, and FIG. 3 is a sectional view of a DC motor. The DC motor 1 according to the present embodiment is used, for example, in a starter for a vehicle, and as shown in FIG. Auxiliary poles 5 are arranged between main magnetic poles 2 adjacent in the circumferential direction via magnet fixing springs 4 (magnet fixing members of the present invention).

The magnet used as the main magnetic pole 2 is magnetized so that an S pole and an N pole appear in the radial direction, and the magnets adjacent to each other in the circumferential direction have different magnetic poles (S pole and N pole). Is reversed). The auxiliary pole 5 uses a permanent magnet like the main magnetic pole 2 and is magnetized so that an S pole and an N pole appear in the circumferential direction. However, it is magnetized so as to have the same polarity as the magnetic pole appearing on the inner peripheral side of the adjacent main magnetic pole 2.

As shown in FIG. 1, the magnet fixing spring 4 is provided by bending an elastic metal plate (for example, a stainless steel plate) into a substantially U-shape.
Is formed (see FIG. 2A). The magnet fixing spring 4 has a base surface 4a forming a U-shape and a pair of side surfaces 4b, and a plurality of outer diameter support portions 4c are provided on the base surface 4a. The outer diameter support portion 4c supports an outer diameter end surface of the auxiliary pole 5 disposed in the auxiliary pole space S, and is provided by cutting and raising a part of the base surface 4a inward (to the auxiliary pole space S side). Have been.

Also, both side surfaces 4b of the magnet fixing spring 4
Is bent inward so that the inner diameter side end portions face each other in the circumferential direction, and both axial portions of the bent piece 4d are the side surfaces 4b.
Elastic locking piece 4 which is cut off from the main body and is elastically deformable in the radial direction.
e is provided. The axial end of the elastic locking piece 4e is bent toward the base surface 4a and provided as a locking portion 4f for supporting the axial end surface of the auxiliary pole 5. Furthermore,
At a substantially central portion of the bent piece 4d, there is provided an elastic projection 4g that can generate elasticity by deforming a part of the bent piece 4d in a convex shape toward the base surface 4a.

Next, a method for fixing the main pole 2 and the auxiliary pole 5 by the magnet fixing spring 4 will be described. First, the auxiliary pole 5 is attached to the magnet fixing spring 4 from the axial direction. At this time, as shown in FIG. 2A, the locking portion 4f of the elastic locking piece 4e of the magnet fixing spring 4 before the auxiliary pole 5 is inserted is slightly inclined upward in the drawing with respect to the bent piece 4d. Is provided. Therefore, the assembling of the auxiliary pole 5 is performed with the elastic locking piece 4e slightly expanded.

As shown in FIG. 2 (b), the auxiliary pole 5 mounted on the magnet fixing spring 4 includes an outer diameter support portion 4c provided on a base surface 4a and an elastic projection 4g provided on a bent piece 4d. Is inserted inside the magnet fixing spring 4 while being slid therebetween, and is disposed in the auxiliary pole space S.
As shown in FIG. 2 (c), the auxiliary pole 5 disposed in the auxiliary pole space S is pressed toward the outer diameter side (downward in the figure) by the elastic force received from the elastic projection 4g, and is provided on the base surface 4a. It is held between the diameter support portion 4c. Also, the elastic locking piece 4e
The supporting portion 4f supports the end face of the auxiliary pole 5 in the axial direction, thereby preventing the auxiliary pole 5 from moving in the axial direction.

Subsequently, the magnet fixing spring 4 with the auxiliary pole 5 is inserted between the circumferentially adjacent main magnetic poles 2 from the axial direction. Here, the single magnet fixing spring 4 is
The circumferential width of the base surface 4a is provided substantially equal to the distance between the adjacent main poles 2 in the circumferential direction, and both side surfaces 4b are provided in a state opened slightly outward. As a result, the magnet fixing spring 4 inserted between the main magnetic poles 2 gives elasticity to the two side surfaces 4b and abuts against the circumferential side surfaces 4b of the main magnetic poles 2, respectively. Fixed to

The main pole 2 is firmly fixed by receiving the elastic force of the magnet fixing spring 4 from both sides in the circumferential direction. Thereafter, as shown in FIG. 3, the locking pieces 4h provided at both ends in the axial direction of the magnet fixing spring 4 are respectively opened outward, whereby the axial end face of the main magnetic pole 2 is supported by the locking pieces 4h. Thus, the axial movement of the main magnetic pole 2 is restricted.

(Effects of Embodiment) According to the magnet fixing spring 4 of this embodiment, elasticity is generated in the elastic projection 4g provided on the bent piece 4d in a state where the auxiliary pole 5 is arranged in the auxiliary pole space S. The auxiliary pole 5 is pressed toward the outer diameter side by the elasticity, and can be firmly held between the auxiliary pole 5 and the outer diameter support portion 4c. As a result, it is possible to prevent rattling of the auxiliary pole 5,
Can be stably held.

As a result, as compared with the case where a conventional magnet fixing spring having no elastic projection 4g is used, the pressing force for holding the auxiliary pole 5 is almost reduced.
g, the load applied to the elastic locking piece 4e can be reduced. Further, since the movement of the auxiliary pole 5 due to the rotational vibration of the armature 6 (see FIG. 3), the armature reaction and the like can be prevented, the elastic locking piece 4e is not broken or deformed, and the elastic locking piece 4e and the armature 6 Interference can be prevented.

(Second Embodiment) FIG. 4 is a perspective view of a magnet fixing spring 4. In this embodiment, the magnet fixing spring 4
This is an example of a case where the outer diameter support portion 4c is formed into an arc shape by press working. In the first embodiment, the outer diameter supporting portion 4c is bent at a substantially right angle with respect to the base surface 4a of the magnet fixing spring 4. In this case, however, the gap between the outer diameter side end surface of the auxiliary pole 5 and the base surface 4a is formed. It is necessary to ensure the radial distance by the length of the outer diameter support 4c.

In order to reduce the radial distance, it is conceivable to reduce the length of the outer diameter support portion 4c. However, if the length of the outer diameter support portion 4c is reduced, press working becomes difficult. . In other words, in order to provide the outer diameter support portion 4c by press working, it is necessary to secure a certain length of the outer diameter support portion 4c. For this reason, in the configuration shown in the first embodiment, since the outer diameter support portion 4c needs a certain length, there is a limit in reducing the radial distance.

On the other hand, in this embodiment, the outer diameter support portion 4
Since c has an arc shape, as shown in FIG.
The radial distance D between the outer diameter side end surface and the base surface 4a can be reduced regardless of the length of the outer diameter support portion 4c. as a result,
The height in the radial direction of the magnet fixing spring 4 can be designed to be small, and the outer diameter of the yoke 3 (see FIG. 3) can be reduced, so that the DC motor 1 can be downsized. The magnet fixing spring 4 of the present embodiment differs from the first embodiment only in the shape of the outer diameter support portion 4c, and the method of assembling the auxiliary pole 5 to the magnet fixing spring 4 is the same (see FIG. 6). is there.

(Third Embodiment) FIG. 7 is a sectional view of the magnet fixing spring 4. This embodiment is a modification of the second embodiment. As shown in FIG. 7, the outer diameter support portion 4c is press-formed into (a) a substantially V shape or (b) a substantially U shape. The same effect as that of the second embodiment can be obtained.

(Fourth Embodiment) FIG. 8 is a sectional view of the magnet fixing spring 4. As shown in FIG. This embodiment is an example of a case where the outer diameter support portion 4c of the magnet fixing spring 4 is bent so as to be inclined with respect to the base surface 4a as shown in FIG. In this configuration, even if the length of the outer diameter support portion 4c is the same as that of the first embodiment, the outer diameter support portion 4c is inclined so that the radial direction between the outer diameter side end surface of the auxiliary pole 5 and the base surface 4a is increased. The distance can be reduced.
In this configuration, since the inclination angle of the outer diameter support portion 4c with respect to the base surface 4a can be set freely, the radial distance can be easily changed according to the inclination angle.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnet fixing spring (first embodiment).

FIG. 2 is a process diagram of assembling an auxiliary pole to a magnet fixing spring (first embodiment).

FIG. 3 is a sectional view of a DC motor.

FIG. 4 is a perspective view of a magnet fixing spring (second embodiment).

FIG. 5 is a sectional view of a magnet fixing spring (second embodiment).

FIG. 6 is a process diagram of assembling an auxiliary pole to a magnet fixing spring (second embodiment).

FIG. 7 is a sectional view of a magnet fixing spring (third embodiment).

FIG. 8 is a sectional view of a magnet fixing spring (fourth embodiment).

FIG. 9 is a front view (a) and a BB cross-sectional view (b) of the magnet fixing spring viewed from the axial direction (prior art).

FIG. 10 is a process diagram of assembling an auxiliary pole to a magnet fixing spring (prior art).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 DC motor 2 Main magnetic pole (permanent magnet) 3 Yoke 4 Magnet fixing spring (magnet fixing member) 4 a Base surface 4 b Side surface 4 c Outer diameter support 4 d Bending piece 4 e Elastic locking piece 4 f Locking section 4 g Elastic projection 5 Complementary pole S Complementary pole space

Continued on the front page (72) Inventor Masahiro Kato 1-1-1, Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 3J022 DA15 EA42 EB12 EC12 EC23 FB12 HB02 HB06 5H622 CA02 CA07 CA10 CA11 CB05 PP03 PP15 PP17 PP18 5H623 AA10 BB06 GG13 GG18 GG24 LL07

Claims (8)

[Claims] 1. A DC motor in which a plurality of permanent magnets are arranged at regular intervals in the inner circumferential direction of a yoke as main magnetic poles and auxiliary poles are arranged between adjacent main magnetic poles via respective magnet fixing members. The magnet fixing member is provided by bending a metal plate having elasticity into a substantially U-shape to provide a set of side surfaces facing each other in a circumferential direction, and an auxiliary electrode for disposing the auxiliary electrode between the two side surfaces. A space is formed, and the inside ends of the both side surfaces are bent inward so as to oppose each other in the circumferential direction, and the axial ends of the bent pieces are cut off from the side surfaces to be elastically deformable in the radial direction. An elastic projection that can generate elasticity is provided on a part of the bent piece, and the supplementary pole pushes the elastic locking piece outward to open, and the auxiliary pole is pushed from the axial direction. Inserted into the pole space and from the elastic projection Kicking DC motor, characterized in that it is pressed and held to the outer diameter side by elasticity. 2. The DC motor according to claim 1, wherein the elastic projection is provided by deforming a part of the bent piece into a convex shape. 3. The DC motor according to claim 1, wherein the elastic locking pieces are provided on both sides in the axial direction of the bent pieces, respectively. ,
A DC motor, further comprising a locking portion that supports an axial end surface of the auxiliary pole disposed in the auxiliary pole space. 4. The DC motor according to claim 1, wherein the magnet fixing member supports an outer diameter side end surface of the auxiliary pole disposed in the auxiliary pole space at a plurality of positions. A DC motor having a support. 5. The DC motor according to claim 4, wherein the magnet fixing member has a base surface radially opposed to an outer-diameter-side end surface of the auxiliary pole disposed in the auxiliary pole space. A direct-current motor, wherein the outer diameter support portion is provided by cutting and raising a part of the base surface toward the auxiliary pole space. 6. The DC motor according to claim 4, wherein the outer diameter supporting portion is formed by press working. 7. The DC motor according to claim 6, wherein a radial distance between an outer diameter side end surface of the auxiliary pole disposed in the auxiliary pole space and the base surface is equal to or smaller than the outer diameter support portion. A DC motor characterized by being set smaller than the length. 8. The DC motor according to claim 6, wherein the outer diameter support portion has a substantially circular arc such that a substantially central portion in a length direction of the outer diameter support portion contacts an outer diameter side end surface of the auxiliary pole. Shape or approximately V
DC motor characterized in that it is press-formed in a letter shape.