JPH04248349A - Terminal board and brush unit of dc motor and fabrication thereof - Google Patents

Abstract

PURPOSE:To produce a highly accurate assembly of brush and terminal board at a high rate by solving the problem of productivity and quality in the production of the assembly of the brush and the terminal board to be employed in a DC miniature motor wherein a brush piece is fed and caulked together with the terminal board and then they are jointed through welding. CONSTITUTION:When an end face 7 on the opposite side to that on the commutator contacting part of a brush 2 is projected from the widthwise end face 6 of a terminal board 1, the terminal board 1 can be caulked with a brush material continuously fed in hoop and the brush 2 can be cut off at the opposite ends thereof with no interference with the terminal board 1 to produce a piece of brush. According to the invention, an assembly of the brush 2 and the terminal board 1 can be produced with high accuracy and at high rate.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a terminal plate and a brush unit for a DC motor, which are often used for acoustic purposes, and a method for manufacturing the same. The goal is to improve the bonding characteristics of the terminal plate and brush for electrical transmission, as well as the bonding accuracy to stabilize the contact pressure and contact angle to the commutator, in order to efficiently transfer electricity through the commutator. It also seeks to pursue the possibility of high-speed production using only mechanical joining, without processes such as welding.

0002

2. Description of the Related Art In the conventional method for manufacturing terminal boards and brush units, as shown in FIG. After inserting it into the joining dowel 14 on the terminal board side and caulking, it was joined by spot welding.

0003

[Problems to be Solved by the Invention] However, in the conventional method, the brush is cut, inserted into the joining dowel of the terminal plate, caulked, and then spot welded, which makes the position of the brush relative to the terminal plate unstable. There is a problem with product quality. In addition, electrode maintenance welding conditions for spot welding, insertion of the cutting brush into the terminal plate, etc. have been issues in realizing high-speed production and high availability production.

0004

[Means for Solving the Problems] In order to solve the above-mentioned problems, the terminal plate and brush unit of the DC motor of the present invention has a width that is smaller than the width of the terminal surface of the terminal plate at the joint portion between the terminal plate and the brush.
It is characterized in that the end surface of the brush opposite to the end surface on the commutator contact portion side protrudes.

[0005] The caulking pin is also characterized in that it has a conical shape with a pointed tip, that its constitutive angle is in the range of 80°<θ≦120°, and that the tool material is carbide.

[0006] Furthermore, the method of rectifying the terminal plate and brush unit of a DC motor according to the present invention includes trimming the outer shape of the joint, and forming a brush having a terminal plate hoop having one or more joint dowels on top, and a brush having slits and joint holes. The terminal board is lowered with the hoop facing down, and the terminal board dowel is inserted into the brush hole.Then, the terminal board dowel is expanded with a temporary caulking pin with a conically pointed tip held mainly below, and the terminal board The brush is joined to the brush, and then the brush cutting punch is lowered to cut the brush, all in one step.

[0007]

[Operation] As described above, the present invention has a configuration in which the end surface of the brush opposite to the commutator contact side end surface protrudes from the width end surface of the terminal board, so that the terminal board can be attached to the brush that is continuously flowed in a hoop shape. In addition to fitting and caulking the joining dowels, both ends of the brush can be cut without interfering with or damaging the terminal board. Productivity can be improved compared to the case of joining with a terminal board.

[0008]

[Embodiment] Fig. 1 shows a terminal plate, a brush unit, and a method for manufacturing the same for a DC motor according to an embodiment of the present invention.
This is a diagram of a brush unit, and the major difference from the conventional example shown in FIG. It consists of caulking 4 for joining points. Another major feature is that from the end surface 6 of the width part of the terminal board 1,
The end 7 of the brush opposite to the commutator contact side protrudes;
The protrusion amount 3 can be seen.

The processing process is as shown in FIG.
1 shows a state in which the terminal plate 1 having the joining dowel 4 is fed in a hoop state before the joining process, and is located above the hoop 2a of the brush 2.

FIG. 2b shows the terminal board joining dowel 4 inserted into the joining hole of the brush 2, and FIG. 2c shows the terminal board joining dowel 4 being pushed and expanded by the tip of the temporary caulking pin 8 shown in FIG. At the same time, the state in which the brush 2 is cut into individual pieces by the cutting punch 10 is shown. Figure 2
d shows a state in which the terminal board hoop 1 is lifted up, the bonded brush 2 is assembled into the terminal board 1, and the remaining state of the brush hoop is shown.

It can be seen that the tip of the temporary caulking pin 8 shown in FIG. 3 is a tool with an angle θ of 80 to 120 degrees.

0012

[Effect of the invention] As a result of comparison with the conventional method, the defective rate is 1/1
10 or less, the improved bonding stability makes it possible to increase the speed and improve productivity by four times.

[Brief explanation of the drawing]

[Fig. 1] A plan view of a terminal plate and brush unit of a DC motor according to an embodiment of the present invention.

[Figure 2] (a) shows the state in which the terminal board is fed in a hoop state before the terminal board and brush are joined together. Figure (b) shows that the terminal board joining dowel has started to be inserted into the dowel joining hole of the brush. Figure (c) shows the state of the brush when it is finished joining. Figure (d) shows the state where the brush has been cut, joined, and lifted.

[Figure 3] Diagram showing the tip shape of the temporary caulking pin

[Figure 4] Plan view of the terminal plate and brush of a conventional DC motor

[Explanation of symbols]

1 Terminal board 2 Brush 4 Joining dowel 8　　　　Caulking pin 10 Cutting punch

Claims (3)

[Claims] 1. A terminal board for a DC motor, characterized in that, at a joint portion between the terminal board and the brush, an end face opposite to the end face of the brush on the commutator contact portion side protrudes from the width end face of the terminal board.
brush unit. [Claim 2] The terminal board is lowered with the terminal board hoop having the outer shape trimming of the joint part and one or more joining dowels facing up, and the brush hoop having the slit processing and the joining hole facing down. The dowel is inserted into the brush hole, then the terminal plate dowel is expanded with a temporary caulking pin with a conically pointed tip held mainly below, the terminal plate and the brush are joined, and then the brush cutting punch is lowered. A method for rectifying a terminal plate and a brush unit of a DC motor, characterized in that the step of cutting the brush is performed in one step. 3. A temporary caulking pin having a conical shape with a pointed tip and a conical angle in the range of 80°<θ≦120°, and a tool material made of carbide. Terminal board, brush unit.