JPS6360626B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a commutator used as an essential part in DC motors, generators, AC rectifiers, etc., and a method for manufacturing the same. The present invention relates to a disk-type commutator suitable for equipping such thin equipment.

The cylindrical commutator that has been commonly used for many years is not only thick in the axial direction and takes up space, but also has the problem that each commutator piece is attached in the centripetal direction, making it easy to peel off due to the centrifugal force generated as it rotates. In recent years, a disk-type commutator has been proposed to eliminate these inconveniences.

Conventional disc-type commutators are known in which each commutator piece is etched onto a printed circuit board, and in which each commutator piece is attached to a disk by press working.

However, the former type, that is, the etched one, not only has poor durability against large currents, but also has a sufficient thickness of the sliding contact part of each commutator piece, for example, at least 1.2 mm. There are some concerns that the requirements cannot be met, and even with the latter method, in which the commutator pieces are attached using a press, there are not only restrictions on the thickness to achieve smooth bending, but also the need to attach each commutator piece to a disk. On the other hand, it is difficult to securely adhere to the surface as a uniform plane, and unevenness is likely to occur, and the installation itself is likely to loosen or shift due to the action of centrifugal force accompanying rotation, etc. There was a problem that the accuracy was forced to decrease.

The surface of the commutator is originally in constant sliding contact with the carbon brush, and its material is copper, which has excellent conductivity. However, copper material is softer than other metals, and while this softness makes the material much easier to process, it also has the disadvantage that the sliding contact portion wears out significantly in a short period of time.

The first object of the present invention is to overcome the above-mentioned tradeoffs, preserve the excellent properties of copper material such as electrical conductivity and ease of processing, while improving the surface hardness of the parts that are in continuous sliding contact with the brush. An object of the present invention is to create and provide a disk-type commutator having commutator pieces that also has high wear resistance and a method for manufacturing the same.

A second object of the present invention is to be able to fabricate the above-mentioned commutator pieces extremely easily and at low cost, and at the same time, to be able to attach each commutator piece evenly and firmly to a disk-shaped substrate, and to use centrifugal force to To create and provide a disk-type commutator and its manufacturing method that do not cause any deviation in installation accuracy even when the device is installed.

To summarize the concept of the present invention, the sliding contact surface of the commutator piece is processed by cold forging, for example, by striking with a header, so that the commutator piece is formed in the shape of a stud with a T-shaped cross section. The hardness of only the surface of the head increases, while the tail, which undergoes crimping and lead wire attachment, remains as soft as before. The main feature is that the two are fixed together while being fitted into the small hole of the disk type substrate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and operation of the present invention will be explained in detail below with reference to figures according to one specific embodiment thereof.

First, as shown in FIGS. 4A and 4B, a conductive material, for example, a copper rod 5 having a predetermined width and thickness is prepared, and the end face of the rod is oriented in the longitudinal direction of the rod. When the rod 5 is hit with a hammer, the cylindrical portion is deformed to form an elliptical plate 6. Furthermore, as shown in FIG. A rivet shape having a T-shaped cross section and consisting of the tail portion 7 is created.

Therefore, as shown in FIG. 4C, the elliptical plate 6 of the head part has its peripheral part removed to form a segment shape 6a, and a part of the tail part 7 is removed to form a terminal protrusion 8. .

Thus, the commutator piece 9 used in the present invention has the shape of a stud with a T-shaped cross section, consisting of a segment-shaped head a and a tail 7 having a terminal protrusion 8.

In addition, the cross-sectional shape of the rod 5 may be rectangular in addition to an elliptical shape (FIG. 4A);
It is desirable that the shape is such that it does not become loose when attached to 2a and 12b.

The operating position of the terminal protrusion 8 may be at one end, the other end, or the center of the tail portion 7.

On the other hand, as shown in FIGS. 1 to 3, the disk-shaped substrate 10 is made by punching an insulating plate material into a circular shape, and at the same time, a large hole 11 for fixing the shaft is formed in the center.
A large number of small holes 12, 12a, 12b, . . . of the same shape and size are carved at equal distances and intervals from the center.
The shape of the small holes is an elongated hole adapted to the tail portion 7 of the commutator piece 9, and these are arranged in rows along the radial direction of the substrate 10. If the shape of the tail portion 7 is oval or angular, the small holes are also shaped accordingly.

Each commutator piece 9 is inserted into these small holes 12, 12a, 12b... from one side of the substrate 10 to the other side,
After fitting by hand or machine, Fig. 4D
As shown in FIG.
15, 16, 15a, 15a,
If you carve 16a, 15b, 16b..., chisel 1
4, the end face of the tail part 7 is deformed by caulking in one step, and each commutator piece 9 has a small hole 1.
2, 12a, 12b, .

In the present invention, as described above, since the segment-shaped head 6a of the commutator piece 9, which is exposed to constant friction by the brush, is cold-forged, the tail part 7 has a high hardness in the sliding contact part. Since the hardness is as soft as the original, it is easy to fix to the substrate 10 without cracking due to caulking. Also,
The forging process sufficiently increases the surface hardness and can create the ideal hardness, so it has sufficient durability, and the above can be achieved reliably, quickly and easily by cold hedging. The device is extremely simple and can be provided at low cost.

Furthermore, in the present invention, each commutator piece 9 is shaped like a rivet with a T-shaped cross section, and the rivet-shaped commutator piece is fitted into the small hole 12 of the substrate 10 and then fixed. Since the installation is strong and there is no risk of it lifting or loosening, the surface of the segment head 6a of each commutator piece is even and smooth, and there is no risk of problems such as brush running problems. , the continuation of smooth contact is guaranteed. The displacement of each commutator piece 9 due to the centrifugal force generated with rotation is reliably prevented by the outer end surface of the small hole 12, so there is no risk of destruction even at high speed rotation, and the installation accuracy is maintained. is maintained without going crazy.

[Brief explanation of the drawing]

The drawings illustrate one specific embodiment of the invention.
Figure 1 is the front view, Figure 2 is the rear view, Figure 3 is the first view.
4. Longitudinal sectional view taken along line 3-3 in Figures and Figure 2.
The figure is an explanatory diagram showing the processing procedure. 5... Copper rod, 6... Elliptical head, 6a... Segment head, 7... Tail, 8... Terminal protrusion, 9... Commutator piece, 10... Substrate, 11... ...Large hole, 12, 12a, 12b...Small hole, 13...
Base, 14...Concentric double cylindrical caulking chisel, 1
5, 16, 15a, 16a, 15b, 16b...
Dent due to caulking.

Claims (1)

[Scope of Claims] 1. An insulating disk-type substrate in which a large hole for fixing a shaft is carved in the center, and a large number of small holes of the same shape and size are carved at equal distances and intervals from the center. and a cross section with a partial hardness difference, i.e. a head part for sliding contact whose surface hardness is strengthened by cold forging, and a tail part whose softness is maintained for fixation in the small hole of said substrate. a large number of commutator pieces made of a conductive material having the shape of T-shaped studs; A disc-type commutator, wherein each of the commutator pieces is caulked and fixed to the substrate by carving a recess in a portion of the body, and a terminal protrusion is provided on another portion of the end face of each tail portion. 2. After cold forging the end face of a rod-shaped conductive material to form a surface-hardened head with a T-shaped cross section, cut the rod in a direction transverse to the middle part to form a tail, and then a commutator piece processing step in which a part of the commutator piece is removed and a caulking fixing part is formed in the removed part and a protrusion for a terminal is formed in the non-deleted part, and the head is processed into a segment shape; A process of manufacturing a disk-shaped substrate by punching a plate material into a circular shape, and punching out a large hole for fixing a shaft in the center and a large number of small holes of the same shape and size at equal distances and intervals from the center, and the substrate. After fitting each of the commutator pieces into all of the small holes from one side to the other, use a cylindrical caulking chisel to fit the removed part of the end face of the tail of each commutator piece. A manufacturing method for a disc-type commutator consisting of a caulking fixing process in which indentations are carved all at once; 3. A method for manufacturing a commutator according to claim 2, in which cold hedging is performed as cold forging. 4. A method for manufacturing a commutator according to claim 2, in which two recesses are simultaneously carved in the removed portion of the end face of the tail portion of each commutator piece using a concentric double cylindrical caulking chisel.