JPS6227017Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an electric brush used for small motors, etc.

As shown in FIG. 1, a conventionally used electric brush has a hole 2 formed in a central recess of a terminal 1.
The tip of the lead wire 3 was inserted into the recess, and the terminal 1 and the lead wire 3 were fixed with solder 4 in the recess. In this case, the connection between terminal 1 and the outside is terminal 1
Since the surface of the solder 4 is held flush with the upper surface of the solder 4, there is a high demand for soldering accuracy, resulting in poor work efficiency. Further, since soldering is performed with the hole 2 facing downward, flux in the solder flows into the lead wire 3 through the hole 2, causing corrosion of the lead wire 3.

It was considered to use a conductive adhesive instead of solder, but this was impractical due to the high electrical resistance of the conductive adhesive and the low workability due to the viscosity of the adhesive.

In order to eliminate soldering, the terminal 1 is formed by pressure molding of conductive powder as shown in Figure 2, but pressure molding uses a mold etc., which limits the shape. There was also a problem with the strength of the bond between the terminal 1 and the lead wire 3. Further, even if the upper end 5 of the lead wire 3 is cut after molding, the upper end 5 of the lead wire 3 remains on the upper surface of the terminal 1.

This invention was made in an attempt to eliminate the drawbacks of the above-mentioned prior art.

The feature of this invention is that a notch is provided in a part of the periphery of the cylindrical metal piece, the tip of the lead wire is inserted through this notch, and the cylindrical metal piece is flattened from the side by pressure molding. The point is that the lead wire is crushed and the tip of the lead wire is crimp-connected to form a terminal.

Here, the shape of the terminal may be determined depending on the brush holder, and may be, for example, one that is bent in one or two stages, or a simple flat plate. The cylindrical metal piece may be processed into a terminal by pressure molding using an appropriate mold or the like. The notch also serves as the insertion point for the lead wire into the terminal.
It works to prevent wire breakage due to friction between the end face of the terminal and the lead wire.

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

FIG. 3 is a front view of an embodiment of the electric brush of this invention, FIG. 4 is a sectional view taken along line A-A', and FIG. 5 is an enlarged view of the main part of FIG. Moreover, FIG. 6 is a perspective view showing the cylindrical metal piece and the lead wire before crimping. In the figure, reference numeral 11 denotes a rectangular parallelepiped brush body whose main components are graphite or graphite and metal powder such as copper or silver. The bottom of the brush body 11 is formed into a curved shape for contact with, for example, a commutator of a motor. The brush body 11 has a head 12 formed of a cylindrical projection, and a lead wire 13 made of twisted wire of metal such as copper is located in the center of the head 12.
The proximal end of the coil spring 14 is fixed to the circumferential surface of the head 12, and the proximal end of a coil spring 14 is held on the circumferential surface of the head 12.

Reference numeral 15 denotes a terminal, in which the tip of the lead wire 13 is inserted into a cylindrical metal piece, and the cylindrical metal piece is pressed flat from the side by pressure molding to form a plate shape, and the tip of the lead wire 13 is crimped. It is connected. If the shape of the cylindrical metal piece is an elliptical shape as shown in FIG. 6, and stress is effectively applied to the lead wire 13 during crimping, a sufficient connection will be achieved. Both sides of the terminal 15 viewed from the tip of the lead wire 13 crimped to the terminal 15 are bent into two stages so that the terminal 15 can be accommodated in a brush holder (not shown), so that the cross-sectional shape of the terminal 15 is square-shaped. ing. This bending process is performed at the same time as the lead wire is crimped onto the terminal 15 using an appropriate mold or the like. Also, the top surface 15a of the terminal 15
is used as an electrical connection between the electric brush and the outside, and the tip of the coil spring 14 is brought into contact with the back surface of the top surface 15a as described later.

A guide 16 is formed by cutting a part of the periphery of the opening of the cylindrical metal piece and bending it so as to protrude from the periphery toward the brush body 11, and is located on the back side of the top surface 15a of the terminal 15. Further, a notch portion accompanying the guide 16 is shown as 17 in FIG. Note that the guide 16 may not be provided. The tip of the lead wire 13 is turned approximately perpendicularly by the guide 16 to the terminal 1.
5 and is crimped. Further, the tip of the coil spring 14 is connected to the guide 16 and the lead wire 1.
It is locked by the introduction part to the terminal 15 of No. 3 and comes into contact with the back side of the top surface 15a of the terminal 15. Guide 16
The width and length of the guide 16 are selected so as to lock the coil spring 14, and the direction in which the guide 16 protrudes from the terminal 15 can prevent the lead wire 13 from being cut due to friction between the lead wire 13 and the edge of the guide 16. For example, set the angle to 90°. The shape of the terminal may be determined depending on the brush holder, and may be, for example, a flat terminal 15' as shown in FIG.

This invention uses crimping instead of soldering, so there are no drawbacks associated with soldering. In addition, if a guide is provided in the notch of the terminal to restrict the introduction of the lead wire into the terminal, it is possible to prevent the lead wire from breaking even though the lead wire is bent at right angles at the terminal. . In addition, if the tip of the coil spring is locked by the guide and the lead wire's introduction to the terminal, the tip of the coil spring will always be in contact with the terminal, and the terminal will be able to contact the terminal from the outside with an appropriate pressing force. do.

[Brief explanation of the drawing]

Figures 1 and 2 show a conventional electric brush,
FIG. 3 is a front view of an embodiment of this invention, FIG. 4 is a sectional view taken along line A-A', and FIG. 5 is an enlarged view of the main part of FIG. Moreover, FIG. 6 is a perspective view showing the cylindrical metal piece and the lead wire before crimping, and FIG. 7 is a front view of a modified example.

Claims (1)

[Scope of utility model registration request] In an electric brush in which a head is provided protruding from the brush body, a tip of a lead wire is fixed to the head, and a base of a coil spring is held on the circumferential surface of the head, a part of the periphery of the opening is provided. By inserting the tip of the lead wire into the inside of a cylindrical metal piece with a notch in the section and flattening the cylindrical metal piece from the side, the tip of the lead wire passes through the notch. An electric brush characterized in that it has a plate-shaped terminal that is crimped and connected, and is configured such that the tip of a coil spring comes into contact with the terminal.