JPH04137477A - Multi-pencil sliding brush - Google Patents

Abstract

PURPOSE:To get a multi-pencil sliding brush free from expansion of the brush pencil or generation of line spacing by a method wherein the multi-pencil whose cross section is an ellipse is resistance-welded into a base material with the long diameter of the elliptic cross section. CONSTITUTION:The pencil 1 of a brush whose cross section is an ellipse is welded into a base material 2 with long diameter of the ellipse made level, and a bend portion 3 shaped in a circular arc whose radius of curvature is 0.3R is formed on the tip portion of the brush so that a multi-pencil sliding brush 4 is constituted. The rigidity of the brush 4 becomes, therefore, greater than of a round wire against a force which intends expand in a rotational circumferential direction, so that the brush 4 can be kept free from expansion of its pencil and also generation of line spacing. It is preferable that the ratio of the short diameter of an elliptical cross section to the long diameter thereof is 1.2-2.0, and if it is less than 1.2, the effect on the rigidity becomes small, and if it is more than 2.0, the number of brushes decreases in relation to a specific width of brush pencil, so that the original purpose and effect of contact stabilization to be obtained by multi-point contact of the multi-pencil sliding brush are reduced. It is thereby possible to get a multi-pencil sliding brush which has stability of contact, a long life, high density, and high accuracy and can be miniaturized, without such troubles as expansion of brush pencil and generation of line spacing.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to improvements in multi-wire bundle sliding brushes used in small electrical devices such as potentiometers and encoders.

(Prior Art and Problems) In the conventional multi-wire bundle sliding brush, as shown in FIGS.
An arcuate curved portion 7 is formed at the tip.

By the way, when the multi-wire bundle sliding brush makes opposing sliding contact with the rotating board, a force that tends to spread toward the outer circumferential direction of the rotation acts due to the difference in circumferential speed and centrifugal force, and the brush wire bundle on the outer circumferential side spreads toward the outer circumference of the rotation. They may become deformed, protrude from the rotating board circuit, come into contact with the rotating board base, or create gaps between the wires, which can cause insulating foreign matter to become involved, resulting in poor contact and shortening the service life. (There was a problem with this, and improvements were required in view of recent advances in high density, high precision, and miniaturization.

(Objective of the Invention) The present invention has been made to solve the above-mentioned problems, and provides a multi-wire bundle sliding brush in which the brush wire bundle does not spread or gaps are not generated between the wires.

(Structure) The technical means of the present invention for solving the above problem is that in a multi-wire bundle sliding brush facing a rotating board, a multi-wire bundle with an oval cross section is placed on a base material with the major axis of the oval cross section horizontal. It is characterized by being resistance welded and having an arcuate curved portion at the tip.

(Function) According to the present invention configured as described above, the rigidity is stronger than that of a round wire against the force that tries to spread in the direction of the rotational outer circumference, and the brush wire bundle does not spread or a gap occurs between the wires. It is something that never happens.

In addition, the ratio of the short axis to the long axis of the rectangular cross section is 1.2 to 2.0.
If it is less than 1.2, the above-mentioned effect of the present invention will be small, and if it exceeds 2.0, the number of brushes in a given brush wire bundle will decrease, and the contact will be stabilized by the multi-point contact inherent to a multi-wire bundle sliding brush. The purpose and effect of the brush is reduced, and the short diameter is made small in order to ensure the number of brushes (then the contact force in the pressing direction cannot be maintained, and the lifespan is shortened due to wear).

(Example) Examples and conventional examples will be described below.

First, as an example, the materials are 30% Ag, 35% Pd, and Pt.
10%, AulO%, Cu14%, Zn1% alloy, cross section oval, major axis 120 μm, minor axis 80 μm, number of 13 brush wire bundles I, material Be2%-Cu, plate thickness 0.1 mm,
Width 2 mm, length 10 positive base material 2 welded, brush length 3
A multi-wire bundle sliding brush 4 was obtained by forming an arc-shaped curved portion 3 with a radius of curvature of 0.3R at the tip of 0.3 mm.

On the other hand, as a conventional example, a brush wire bundle 5 made of the same material as in the embodiment, having a circular cross section, linearity of 80 μm, and 20 wires (same as in the multi-wire bundle in the embodiment) is welded to a base material 6 of the same material and shape as in the embodiment. , a curved portion 7 was formed to obtain a multi-wire bundle sliding brush 8.

However, the material is Au/ceramic, the outer diameter of the circuit is 20 mm,
When a sliding test was conducted with a rotating circuit board having an inner diameter of 16 mm and a contact force of 20 g and a sliding number of 100,000 times, the following results were obtained.

In this way, in the conventional example, the average value was 0.15 mm after the test compared to the beam before the test, and the difference between the upper limit and the lower limit was 0.21 mm, and there was a large variation, whereas in the example The spread was small, with an average value of 0.05 mm, and the variation in the difference between the upper and lower limits was 0.03 mm, which was extremely good.

(Effects of the Invention) As is clear from the above results, in the multi-wire bundle sliding brush of the present invention, the multi-wire bundle with an oval cross section is resistance welded to the base material with the major axis of the oval cross section horizontal, and the tip Since the arc-shaped curved part is formed on the part, the rigidity in the outer circumferential direction is strong, and the brush wire does not spread or create gaps between the wires, so the contact is stable and has a long life. This has the excellent effect of making it possible to manufacture compact electrical equipment with high density, high precision, and miniaturization.

[Brief explanation of the drawing]

FIG. 1a is a perspective view showing a multi-wire bundle sliding brush according to an embodiment of the present invention, FIG.
2 is a sectional view showing a conventional multi-wire bundle sliding brush, and FIG. 2 is a sectional view taken along line BB in FIG. 2a. Applicant: Tanaka Kikinzoku Kogyo Co., Ltd. Figure (a) Figure (b) 4...Taakae PI★ηFushi

Claims (1)

[Claims] 1) In a multi-wire bundle sliding brush facing a rotating board, a multi-wire bundle with an oval cross section is resistance welded to the base material with the long axis of the oval cross section being horizontal, and an arcuate curved part is formed at the tip. A multi-line bundle sliding brush.