JPH0250702B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a method for manufacturing a commutator used in a rotating electric machine.

[Conventional technology]

Conventionally, a method for manufacturing a commutator used in a rotating electrical machine has been as follows. First, a hoop material drawn into a predetermined shape and dimension is cut to produce a segment 1 as shown in FIG. After fitting the protrusions 5 of the segments 1 into the V-grooves 4 on the inner circumferential surface of the cartridge 3 having the receiving portion 2 and positioning them one by one, a cap 6 is placed on top to prevent the segments 1 from shifting and falling. As shown in FIG. 1C, the cartridge 3 is placed in a resin molding mold 7. At that time, mold 7
Inside is a center pin 8 biased by a spring 9.
The cartridge 3 is inserted into the mold 7 by aligning the disc-shaped guide 10 at the tip of the center pin 8 with the inner periphery of the segment 1, and the cap 6 is removed. Thereafter, mold resin is injected into the mold 7 from above in FIG.
The cylindrical commutator was molded by pressing the segment 1 and lowering it as the resin was filled, and cutting the outer periphery of the segment 1 removed from the mold 7 and cartridge 3.

[Problem to be solved by the invention]

However, with this commutator manufacturing method, the segment 1 positioned inside the cartridge 3 is likely to shift or fall when the cap 6 is attached or removed, and the segment 1 positioned inside the cartridge 3 is likely to shift or fall.
The workability of inserting the cartridge 3 into the mold 7 for resin molding was poor, resulting in low productivity.

[Structure of the invention]

In view of the above problems, the present invention provides a head having a substantially triangular cross-sectional shape, a neck bulging at the top of the head, and a fan-shaped convex portion formed on the side opposite the neck of the head. or a step of forming a segment having a concave portion, the convex portion or concave portion of the segment is formed into a cartridge having a cylindrical shape and a plurality of fan-shaped concave portions or convex portions formed at equal intervals on the inner circumferential surface of the cartridge; The process of arranging a large number of segments on the inner periphery of the cartridge by press-fitting them into the convex parts, the process of placing the cartridge with the segments arranged in a mold for resin molding, and the process of injecting resin into the mold and forming the segments on the inner periphery of the cartridge. a step of molding the part and neck part to embed them in resin;
and a step of taking out a large number of integrated segments and cutting the outer periphery thereof.

[Effect]

With the above configuration, when arranging the segments in the cartridge, when placing the cartridge in the mold, etc., the segments do not fall or become misaligned.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

First, the segment 11 used in the present invention is a segment manufactured by cutting a hoop material made by drawing a copper material into a predetermined cross-sectional shape as shown in FIG. part 12 and a neck part 1 formed by bulging at the top of the head part 12.
3, and a fan-shaped convex portion 14 is integrally molded on the side of the head 12 facing the neck portion 13 over the entire length in the axial direction. The head 12 serves as a sliding surface for a brush (not shown) of a rotating electrical machine, and the neck 13 is embedded in a molded resin to prevent the segment 11 from coming off, as will be described later. The convex portion 14 is designed such that the relational expression a>b holds true, where a and b are the dimensions of the convex portion 14.

As shown in FIG. 3A, the cartridge 16 has an appropriate number of recesses 17 provided at equal intervals on its inner peripheral surface. The recess 17 is the segment 1 to be press-fitted.
The shape is the same as the convex part 14 of the head 12 of No. 1, and a≧
It has a shape and size such that a', b≧b'. Figure 3 C is
3B is an enlarged view of the recess 17 shown in FIG. 3A. FIG. FIG. 3D is an enlarged view of the entrance portion of the recess 17,
The obliquely viewed portions 19, 19 are cut and a chamfered portion 20 of approximately 0.5C is provided at the entrance. As a result, the recessed part 17 is divided into an upper part 21 and a lower part 22, and the lower part 22 has the same dimensions as the recessed part 17 shown in FIG. This is a maximum of about 0.05m/m.

Next, the manufacturing method of the present invention will be explained.

First, as described above, the segment 11 including the head 12, neck 13, and fan-shaped convex part 14 is formed, and then the convex part 14 of the segment 11 is press-fitted into the concave part 17 of the cartridge 16, and the cartridge 1
A large number of segments 11 are arranged at equal intervals on the inner periphery of 6. At this time, since the input side of the recess 17 of the cartridge 16 is slightly wider than the protrusion 14 of the segment 11, it is initially in the inserted state, and the protrusion 14 of the segment 11 is inserted into the cartridge 1.
6 into the recess 17. Then, the convex portion 14 of the segment 11 is gradually press-fitted into the concave portion 17 of the cartridge 16, and the segment 11 is securely fixed to the inner periphery of the cartridge 16. Subsequently, the cartridge 16 in which a large number of segments 11 are arranged is placed in a resin molding mold, and resin is injected into the mold to perform molding. This causes the head 1 to protrude into the cartridge 16.
2 and the neck portion 13 are embedded in resin, and a large number of segments 11 are integrated. A cylindrical commutator is formed by taking out the segments 11 from the cartridge 16 in an integrated state and cutting the protrusions on the outer periphery.

Note that instead of the convex portion 14 of the segment 11, the second
The recess 15 may be fan-shaped as shown in FIG.

〔effect〕

As described above, the method for manufacturing a commutator according to the present invention involves positioning and supporting the protrusions or recesses provided on the head of the segment by press-fitting them into the recesses or protrusions provided at equal intervals on the inner peripheral surface of the cartridge. , has the following advantages.

Segment positioning becomes easy and reliable, and the occurrence of burrs due to inclination can be prevented.

The cartridge was manufactured by broaching, which improved surface accuracy and eliminated the occurrence of burrs.

Productivity has been improved by eliminating the time loss of loading cartridges into resin molding molds.

Quality has improved and defective products have disappeared.

It was a very simple construction change and did not increase costs.

[Brief explanation of the drawing]

FIG. 1 shows a conventional method of manufacturing a mold commutator. FIGS. 2A and 2B are a perspective view and a sectional structural view of an embodiment of a segment according to the present invention. Figure 3 A,
B and C are perspective views of an embodiment of a cartridge according to the present invention. FIG. 3D is a detailed explanatory diagram of the cartridge shown in FIG. 3C according to the present invention. Explanation of symbols, 1: Segment, 2: Segment falling-off prevention receiver, 3: Cartridge, 4: V
Groove, 5: Protrusion, 6: Cap, 7: Resin mold, 8: Center pin, 9: Spring, 10: Guide, 11: Segment, 12: Head, 13: Neck, 14: Convex part, 15: Recessed portion, 16: Cartridge, 17: Recessed portion, 18: Convex portion, 19: Shaded portion, 20: Chamfered portion, 21: Upper portion, 22: Lower portion,
a, b: shape and dimensions of the convex portion 14 and concave portion 15, a′,
b': Shape and dimensions of the recess 17; c, d: dimensions of the upper end of the upper part 21;

Claims (1)

[Claims] 1. A head 12 having a substantially triangular cross-sectional shape, a neck 13 bulging at the top of the head 12, and a fan-shaped convex portion 14 or concave portion formed on the side of the head 12 facing the neck 13. 15, the cartridge 16 is cylindrical and has a large number of sector-shaped recesses 17 or projections 18 formed at equal intervals on its inner circumferential surface, and the projections 14 or recesses of the segment 11 are 15 is press-fitted into the recess 17 or protrusion 18 of the cartridge 16 to arrange a large number of segments 11 on the inner periphery of the cartridge 16, and the cartridge 16 with the segments 11 arranged therein is placed in a resin forming mold. A process of injecting resin into a mold and molding the head 12 and neck part 13 of the segment 11 so as to be embedded in the resin, and removing a large number of integrated segments 11 and cutting the outer periphery. A method for manufacturing a commutator, comprising the steps of: