JPH02299187A - Method for welding brush line material of brush contact - Google Patents

Abstract

PURPOSE:To prevent difference in welding strength between an external brush line and an internal brush line by providing a groove on a contact face of a roll electrode for resistance-welding a brush line bundle. CONSTITUTION:A plurality of brush lines 1 are arranged without interval and bundled into a brush line bundle, pressed and resistance-welded to a belt-like base material via an upper roll electrode 3 and a lower roll electrode 4. A groove 2 on the outer periphery of the upper roll electrode 3 keeps the brush line bundle tight as well as pressure-welds it against the outer periphery of the lower roll electrode. A groove 8 is provided at the center of a contact part with the brush line bundle on the outer periphery of the lower roll electrode 4 wherein the width is approximately 1/3 to 1/2 of the brush line bundle and the depth is such that the brush line 1 may not be in contact with the outer periphery of the lower roll electrode. More current flows toward both sides of the brush line bundle owing to this groove 8 to compensate the brush lines on both sides for insufficiency in welding strength due to cooling by the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for welding brush wires for brush contacts used in trimmers, potentiometers, and the like.

(Prior Art) Conventionally, as shown in FIG. 3, a brush wire welding method for a brush contact point involves forming a groove 2 with a width that can accommodate the required number of brush wires 1 without any gaps and a depth smaller than the wire diameter of the brush wires 1. The upper roll electrode 3 having an outer circumference of the upper roll electrode 3 is rotated to supply the required number of brush wires 1 to the groove 2 on the outer periphery and transfer them in alignment, and a window hole 5 is formed between the upper roll electrode 3 and the lower roll electrode 4. There is a method in which the attached base material 6 is transferred and a required number of brush wires 1 are resistance welded to the beams 7 of the belt-like base material 6.

(Problem to be Solved by the Invention) By the way, in the brush wire welding method for the brush contacts described above, current flows through each of the brush wires 1 and generates heat, but the brush wires 1 at both ends dissipate heat quickly, so it is difficult to weld until the brush wires 1 are welded. Something happens that doesn't go well. As a result, one or two brush wires 1 at both ends appear to have very low welding strength.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for welding brush wires at brush contact points, which can increase the welding strength of the brush wires at both ends and stabilize the welding strength of the entire brush wire.

(Means for Solving the Problems) The brush wire welding method for brush contacts of the present invention to solve the above-mentioned problems has a width that can accommodate the required number of brush wires without any gaps and a depth that is smaller than the wire diameter of the brush wires. The upper roll electrode having a groove on the outer periphery is rotated, and the required number of brush wires are supplied to the groove on the outer periphery and transferred in alignment, and the upper roll electrode and the lower roll electrode having a groove in the center of the outer periphery are connected to each other. The method is characterized in that a band-shaped base material with window holes is transferred between the steps, and a required number of brush wires are resistance welded to the edges of the band-shaped base material.

(Function) As described above, in the brush wire welding method of the brush contact of the present invention, when resistance welding the required number of brush wires and the slats of the band-like base material with window holes, the lower roll having a groove in the center of the outer periphery is used. Since electrodes are used, there are parts of the band of the band-shaped base with window holes that do not come in contact with the lower roll electrode, and as a result, a large amount of current flows on both sides, and the brush wire at both ends also generates sufficient heat, causing the band of the band-shaped base to become heated. Welding is ensured and the welding strength of the entire brush wire is stabilized.

(Example) An example of the brush wire welding method for a brush contact of the present invention will be described in the first example.
To explain with a diagram, a brush wire 1 with a wire diameter of 75 μm is
An upper roll electrode 3 made of a chromium-copper alloy with a width of 12++ m and an outer diameter of 100 m+s, which has a groove 2 on the outer periphery with a width of 1.6 mm and a depth of 50 μm smaller than the wire diameter of 75 μm and has a width of 1.6 mm that can accommodate one brush wire without a gap, is rotated at 3 Rotating at .2 rpm, 21 wires of Ag-Pd40%-Cu with a diameter of 75 μm
A brush wire material 1 made of 20% is placed between an upper roll electrode 3 and a width of 0.55 m at the center of the outer periphery having the same dimensions as the upper roll electrode 3.
, lower roll electrodes 4 and 0 provided with a V-groove 8 with a depth of 0.5 m.
In between, a strip-shaped base material 6 made of PBS having a width of 10w and a thickness of 0.2fi having a window hole 5 of 2.1fi in length and 6IoII in width is transferred, and the projection 7a of the strip-shaped base material 6 has a height of 50 μm. The 21 brush wire rods 1 were sequentially projection welded to the rod 7.

A base material 6 on which the brush wire rod 1 is projection welded in this way
After that, the left and right ends of the rod 7 were cut off as shown in Fig. 2, and the brush wire 1 was cut to a length of 2.5111 mm from the position of the rod 7, and the tip of the brush wire 1 was then molded all at once. A semicircular contact portion 9 of 0.5 mH was formed on the lower side to obtain a brush contact 10.

For these 1000 brush contacts, the welding strength of the brush wire 1 was measured one by one, and it was found that the welding strength of the brush wire 1 welded at the center of the rod 7 and the one of the brush wire 1 welded at the left and right sides of the rod 7 There is almost no difference in the welding strength of the book, which is high at around 80g.
The variation was extremely small, less than ±5 g, and the welding strength of the entire brush wire 1 was stable.

In the above embodiment, the V-groove 8 is provided on the outer periphery of the lower roll electrode 4, but the present invention is not limited to this, and a U-groove or a square groove may also be used. In addition, the depth of the V groove, U groove, and square groove is 0.5 to 1. OB is preferable, and the width is preferably 1/3 to 1/2 of the width of the wire bundle of the brush wire 1 from the viewpoint of heat balance.

(Effects of the Invention) As can be seen from the above description, the brush wire welding method for brush contacts of the present invention is effective when resistance welding a required number of brush wires to a window or a slotted band base material at the center of the outer periphery. Since a lower roll electrode with grooves is used, there are parts of the window hole-equipped strip base material that do not come into contact with the lower roll electrode, and a large amount of current flows to both sides. Therefore, the brush wire at both ends also generates sufficient heat, and is reliably welded to the edge of the band-shaped base material, increasing the welding strength and stabilizing the welding strength of the entire brush wire.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a brush wire welding method for a brush contact of the present invention, and Fig. 2 is a perspective view showing a method of welding a brush wire for a brush contact point of the present invention, and Fig. 2 shows a product obtained by cutting the edge of a band-shaped base material with window holes to which brush wire is welded, and cutting and processing the brush wire. FIG. 3 is a perspective view showing a conventional brush wire welding method for a brush contact. Applicant Tanaka Kikinzoku Kogyo Co., Ltd. Figure 2 8... Lower life-lL/electronic blind external use/) V groove construction Figure 3

Claims (1)

[Claims] 1. The upper roll electrode, which has a groove on its outer periphery with a width that can accommodate the required number of brush wires without any gaps and a depth smaller than the wire diameter of the brush wires, is rotated to supply the required number of brush wires into the grooves on its outer periphery. At the same time, a strip material with a window hole is transferred between the upper roll electrode and a lower roll electrode having a groove in the center of the outer periphery, and the required number of brush wires are placed on the edge of the strip material. A brush wire welding method for brush contacts characterized by resistance welding.