JPH0689768A - Commutator for rotating electric machine and manufacture of the same - Google Patents

Abstract

PURPOSE:To provide a commutator for a rotating electric machine free from fold-back of a segment to be generated by dispersion in the locating of segment at the time of fabrication. CONSTITUTION:A segment ring 14 is made of a plurality of segments 51 which are connected together by bridging pieces 24 and is so formed that the mating surface 40 produced by butting of conductive material is positioned a certain dimension inside of the end face in circumferential direction of segment 51, i.e., near the center in the circumferential direction of the segment 51. The bridging pieces 24 are removed, and the segments 51 are separated. Accordingly no fold-back is produced at the end face of the segment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a commutator for a rotary electric machine and a method for manufacturing the commutator.

[0002]

2. Description of the Related Art FIG. 4 is a front view of a conventional commutator for a rotary electric machine disclosed in Japanese Patent Publication No. 58-5515, and FIG.
It is the side view seen from the left. In the figure, 1 is a segment and 2 is a groove filled with a mold resin as an insulating material. 3 is a riser having a riser groove 4. Reference numeral 5 is a mold resin portion as an insulating material, and 6 is a hole for fitting with an armature shaft (not shown).

In order to make the above-mentioned commutator, for example, the rod-shaped conductive material 7 shown in FIG. 6 is cut so that the length between both ends 8 and 9 thereof becomes a predetermined dimension, and the conductive material 7 is bent to form a diagram. The annular body 11 shown in 7 is formed. In FIG. 7, 10 is a butt portion of both ends 8 and 9 shown in FIG. 6, which is a facing surface 30 which is a facing portion of a conductive material.
(Fig. 11). FIG. 8 shows a method of forming the segment ring 14 by subjecting the annular body 11 to plastic working, such as cold forging. Figure 8
The left half shows the state before cold forging, and the right half shows the state after cold forging. In the figure, 12 is an upper mold, 13 is a lower mold, and the annular body 11 is placed on the lower mold. 9 shows the core type 15 shown in FIG.
In the sectional view of FIG. When the upper die 12 is lowered in the drawing of FIG. 8, the annular body 11 is plastically deformed as shown in the right half of FIG. 8, and the segment ring 14 is formed.

FIG. 10 is a front view of the segment ring 14 formed by the above method, and the segment 1 has a foot portion 22. 24 is a bridging piece connecting each segment 1. 21 is a groove. FIG. 11 is an enlarged view of the vicinity of segment 1 in FIG. Since the annular body 11 has the abutting portion 10 as shown in FIG. 7,
When cold forging is performed, the facing surface 30 shown in FIG. 11 is produced. FIG. 12 shows a cross-sectional view after processing the segment ring shown in FIG. Foot 22 of segment ring 14 formed as described above
As shown in FIG. 12, the skirt 29 is expanded into a shape of a skirt 29 to prevent it from coming off. Further, the riser ring 19 has a riser groove 4 and a groove 21.
After machining the groove 2 communicating with, and after molding with molding resin, cut to the one-dot chain line 25 shown in FIG. 11, cut the bridging piece 24 and separate it into each segment 1 as shown in FIG. create.

As described above, the method of aligning the facing surface 30 with the center of the groove 21 is adopted. However, the width of the groove 21 is 0.
Since it is about 5 mm, in the case of mass production, some deviation occurs as shown by the facing surface 31 shown by the dotted line in FIG.
In this case, when the annular body 11 is plastically deformed during cold forging, the flow of the material of the conductive material is as shown by arrows A and B in FIG.
Head toward the center line C of. Therefore, the facing surface 31 shown by the broken line in FIG.
When it is slightly displaced from the center of the groove 21 as shown in FIG.
Enter the area of. In this state, when the undercut 28 is inserted as shown in FIG. 12, the burr 27 is generated at the end 61 of the segment 1 due to the facing surface 32.

[0006]

Since the conventional commutator is constructed as described above, the burr is likely to occur in the segment due to the variation in the positioning, and the burr causes the burr during the operation of the electric motor to the burr. There were problems such as collisions, brush dance, deterioration of rectification, short circuit between segments, and other problems.

The present invention has been made to solve the above problems, and an object thereof is to obtain a commutator for a rotating electric machine in which no burr is generated in a segment, and a rotating electric machine in which no burr is generated in a segment. An object of the present invention is to provide a commutator manufacturing method.

[0008]

According to the commutator for a rotating electric machine of the present invention, a segment is provided with a first conductive material and a second conductive material at a position where a segment has a predetermined size from an end face in the circumferential direction of the commutator for a rotating electric machine.
The conductive material has a facing portion facing each other. Further, according to the manufacturing method of the present invention, the segment ring is formed by positioning the segment so that the facing portion is located inside the commutator for the rotary electric machine in the predetermined dimension from the circumferential end face.

[0009]

In the present invention, the segment is a facing portion in which the first conductive material and the second conductive material face each other at a position inside a predetermined size inside from the circumferential end surface of the commutator for a rotary electric machine. Since it has been arranged, the burr of the segment does not occur. Further, in the manufacturing method of the present invention, since the segment ring is formed such that the segment is positioned so that the segment faces the inner side of the end face in the circumferential direction of the commutator for a rotary electric machine by a predetermined dimension, the positioning of the segment ring varies during molding. However, there is no burr in the segment.

[0010]

【Example】

Example 1. One embodiment of the present invention is shown in FIGS. FIG. 1 is an enlarged view of a part of the segment ring 14. In the figure, 1 to 24 are the same as or equivalent to the conventional example.
The method of forming the annular body 11 from the conductive material 7 is the same as the conventional method. In FIG. 1, 51 is a segment, 51a is a segment on the left side in the figure as a first conductive material, 51b is a segment on the right side in the figure as a second conductive material, and 40 is a first and second conductive material. It is a facing surface that faces each other. The left segment 51a and the right segment 51b form one segment 51. In FIG. 1, the segment ring 14 is formed such that the facing surface 40 is located inside the circumferential end surface of the segment 51 by a predetermined dimension, that is, near the central portion of the segment 51 in the circumferential direction. Then, as shown in FIG.
Form a skirt 29 on. After that, it is manufactured in the same manner as the conventional example.

FIG. 2 is a view when the facing surface 41 is displaced from the center line C of the segment 51 due to variations in positioning during molding. In this case, when the annular body 11 is cold-forged, the conductive material of the annular body 11 flows like the lines A and B, and the left and right flows collide with each other.
It is near the center line C of 51. Therefore, even if the undercut 28 is processed as in the conventional example shown in FIG. 12, since the facing surface 41 is near the center of the segment 51, burr does not occur.

Although the commutator with riser has been described in the embodiment, a commutator without riser may be used. Also,
Although cold forging has been described as the forming method, it may be formed by extrusion forming, warm forging, or the like.

[0013]

As described above, according to the present invention, the segment is provided with the first and second conductive materials at a position inside a predetermined dimension from the circumferential end surface of the commutator for a rotary electric machine. Since it is configured to have the facing portions facing each other, the burr at the end portions of the segments is eliminated even if the positioning is varied during manufacturing. Further, in this manufacturing method, since the segment ring is formed by positioning so that the facing portion of the conductive material is located at a position where the segment is inside a predetermined dimension from the circumferential end surface of the commutator for a rotary electric machine, the segment ring is formed. There is no burr on the end face.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a segment ring of a commutator for a rotating electric machine according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram when the position is displaced in FIG.

FIG. 3 is a cross-sectional view showing a processed foot portion in FIG.

FIG. 4 is a cross-sectional view of a conventional commutator for a rotary electric machine.

5 is a side view of the commutator for a rotary electric machine of FIG. 4 as viewed from the left side.

FIG. 6 is a front view of a conductive material for a segment ring.

FIG. 7 is a front view of the conductive material of FIG. 6 formed in an annular body.

FIG. 8 is an explanatory diagram of cold forging processing.

9 is a cross-sectional view of the core die of FIG.

FIG. 10 is a cross-sectional view when a segment ring is formed.

11 is an enlarged view of FIG.

12 is a cross-sectional view of the segment ring of FIG. 11 processed.

[Explanation of symbols]

 2 Groove 14 Segment ring 21 Groove 24 Bridge section 40 Opposing surface 51 Segment 51a Left segment 51b Right segment

Claims (2)

[Claims] 1. A cylindrical commutator for a rotary electric machine, comprising a plurality of segments supported by an insulating material, wherein the segment is located at a position inside a predetermined dimension from an end face in the circumferential direction of the commutator for the rotary electric machine. A commutator for a rotating electric machine, wherein the first conductive material and the second conductive material have facing portions that face each other. 2. A ring-shaped conductive material is formed into a ring-shaped body having opposed portions whose ends are abutted, and the ring-shaped body is subjected to plastic working to form a segment ring in which segments are connected by a plurality of bridging pieces. Then, after supporting the segment ring with an insulating material, in the method for manufacturing a commutator for a rotating electric machine, wherein the bridging piece is removed to separate the segment, the segment is a circumferential direction of the commutator for the rotating electric machine. A method for manufacturing a commutator for a rotary electric machine, characterized in that the segment ring is formed by positioning so that the facing portion is located at a position inside a predetermined dimension from the end face.