JPH0555741U - Unbalanced thickness yoke of rotating electric machine - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a yoke for a rotary electric machine, which is capable of forming a flange with a small amount of material and is lightweight. [Structure] An eccentric thickness yoke 10 of a wiper motor is a cylindrical yoke having a permanent magnet 11 arranged on the inner periphery thereof, and is provided with a flange 10c. The yoke 10 has a flat portion 10d which is thinner than the other yoke portions at the position where the permanent magnet 11 is arranged, and a flange 10c.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a rotary electric machine yoke, and more particularly to a rotary electric machine yoke having a flange.

[0002]

[Prior Art]

 2. Description of the Related Art Conventionally, in a rotary electric machine, for example, a motor that constitutes a magnetic circuit using a permanent magnet as a field, the yoke has a cylindrical shape having a uniform wall thickness. Generally, when forming a cylindrical yoke in a motor, it is performed by deep drawing in which a material is processed into a die having a predetermined cylindrical shape by a punching force. A flange for assembly is formed (see, for example, Japanese Utility Model Laid-Open No. 63-40142).

[0003]

[Problems to be solved by the device]

 As described above, since the yoke shape is a cylindrical shape having a uniform wall thickness, in order to reduce the weight of the motor in the yoke, the wall thickness of the yoke as a whole must be adjusted. There was a limit to the weight reduction of the yoke due to the saturation of the internal magnetic flux density. When forming the flange, a punching process is performed to form a portion corresponding to the flange after forming the yoke shape by drawing, but a large material is used so that the size of the flange can be secured in advance. I had to keep it.

An object of the present invention is to provide a yoke for a rotary electric machine, which is capable of forming a flange with a small amount of material and is lightweight.

[0005]

[Means for Solving the Problems]

 The uneven thickness yoke of the rotating electric machine according to the present invention is a cylindrical yoke having a stator arranged on the inner circumference thereof, and the yoke of the rotating electric machine is provided with a flange, the yoke being provided with the stator. At the position, the flange is formed thinner than the other yoke portions.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. The parts, arrangements, etc. described below do not limit the present invention and can be variously modified within the scope of the present invention.

1 to 3 show an embodiment of the present invention. In this embodiment, a wiper motor will be described as an example of a rotary electric machine. As shown in FIG. 1, the wiper motor M of this example includes a yoke 10 as a stator, a permanent magnet 11, an armature 12, a brush device 13, etc., and the armature 12 has an armature shaft 14, a winding wire. The brush device 13 includes a brush case 13a, a brush 13b, a spring 13c, and a pigtail 13d. The brush device 13 is attached to the substrate 19 and is attached to the yoke 10. The yoke 10 is attached to the gear housing 18 with screws. Of these, except for the yoke 10, it has a conventionally known configuration. Reference numeral 17b is a bearing on the output shaft side of the armature shaft 14, and reference numeral 10e is a mounting hole for a gear housing.

As shown in FIG. 2, the yoke 10 of this example has a bottomed cylindrical shape with one end open, and a bearing portion 10 a is formed on the bottom portion side. Thus, the bearing 17a is arranged to support the opposite output side of the armature shaft 14, and the permanent magnet 11 is arranged on the inner circumference of the yoke 10. On the opening end 10b side of the yoke 10, flanges 10c are integrally formed with the yoke 10 at both left and right positions.

As shown in FIG. 3, the yoke 10 of the present example has an inner circumference that is circular in cross section as in the conventional case, but the flattened portions 10d and 10d, which are thinner than the other yoke 10, are two. It has been formed. The flanges 10c, 10c are formed so as to match the positions where the flat portions 10d, 10d are formed. Inside the flat portion 10d, the above-mentioned permanent magnet 11 is arranged so as to be located at a substantially central position.

In this example, as described above, a part of the yoke 10 is thinned, but the thinned flat portion 10d of the present example is the back part of the permanent magnet 11 (this example is not used as a magnetic path). , So that the magnetic circuit in the yoke 10 is not affected. That is, according to the test results, for example, in the wiper motor M as in this example, the circumferential angle of the permanent magnet 11 used is 140 °, as shown in FIG. At the magnetic path within the range of 15 ° to the left and right, that is, at the position of the flange 10c, the magnetic force lines are sparse, and are separated from the dense magnetic field lines, so that the characteristics of the motor M are hardly affected. .

As described above, according to this example, since the flattened portion 10d having the thin wall is formed on the flange 10c, the weight is reduced and the flattened portion 10d allows the conventional cylindrical yoke to be formed. Unlike 10, it is hard to roll, and the stability during automatic assembly in the assembly process can be improved.

Next, the manufacture of the yoke 10 having the above structure will be described. The yoke 10 can be manufactured, for example, as follows. That is, the die 20 having the circular holes 21 as shown in FIG. At this time, the punch 30 is the same as the conventional one, but the gap between the punch 30 and the hole 21 of the die 20 at a predetermined position, in this example, two places, is narrower than that of the other die 20. Has been formed. Then, specifically, first, a disk-shaped material having a predetermined plate thickness is placed on the die 20, and the punch 30 is inserted in the axial direction. The tip 31 of the punch 30 is formed in the shape of the bearing portion 10a described above, and the shape of the tip 31 directly forms the bearing portion 10a which is the bottom portion of the yoke 10.

Next, as the punch 30 moves into the die 20, the central portion of the material is next squeezed, and at the same time, the outer peripheral portion of the material slides on the surface of the die 20 and moves toward the hole 21. Go. When the material is squeezed, the material is squeezed in the circumferential direction at the entrance of the hole 21 of the die 20, and at the same time, it is bent while receiving radial tension. Direction). The portion that becomes the side wall of the yoke 10, that is, the portion where the permanent magnet 11 is disposed is pulled in the vertical direction.

At this time, as described above, the predetermined portion of the yoke 10 (the portion that becomes the flattened portion 10d) is formed to be narrower between the punch 30 and the die 20 than the other portions, so that the portion of this portion is reduced. At the same time, the material is thinner than other parts, and at the same time, the material at the entrance of the die 20 moves less toward the hole 21 than the other parts. In other words, the flat portion 10d is in a state of a kind of ironing, and when the other material portion is in the hole 21 of the die 20, the position of the thin portion (that is, the flat portion 10d). At the entrance portion of the hole 21 corresponding to the position (1), the material is stretched and flows in the direction of the flange 10c as a portion of the flange 10c, and remains at the entrance portion of the die 20.

That is, as shown in FIG. 5, when the yoke 10 is processed, the side surface of the yoke 10 that is the uneven thickness portion is stretched in the drawing direction, so that the material flows in the direction of the flange 10c. As a result, the thickness of the side surface of the yoke 10 corresponding to the position of the flange 10c is reduced. Further, the flange 10c can be produced with the size of the material being the minimum size required to form the cylindrical portion of the yoke 10. Then, a hole 10e for mounting the gear housing 18 is bored in the flange 10d. In the above example, the yoke 10 is formed by deep drawing, but it may be formed by forging or the like.

[0016]

[Effect of the device]

 As described above, according to the eccentric thickness yoke of the rotating electric machine of the present invention, unnecessary thickness of the yoke can be diverted to the flange, which makes it possible to reduce the weight of the yoke and to reduce the material. The amount used can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rotary electric machine using an uneven thickness yoke according to the present invention.

FIG. 2 is a cross-sectional view of a yoke including a stator.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is an explanatory diagram of a magnetic circuit.

FIG. 5 is an explanatory diagram showing a flange formation in processing of an uneven thickness yoke.

FIG. 6 is a partially cutaway explanatory view of a processing device for an uneven thickness yoke.

[Explanation of symbols]

 10 yoke 10c flange 10d thin wall (flat part) 11 permanent magnet M rotating electric machine (wiper motor)

Claims (1)

[Scope of utility model registration request] 1. A yoke for a rotary electric machine, comprising a cylindrical yoke having a stator disposed on the inner circumference thereof, the yoke having a flange,
An uneven thickness yoke of a rotary electric machine, wherein the yoke is formed thinner than other yoke portions at the position where the stator is arranged and the flange is formed.