RU1773304C - Contact bridge - Google Patents

Abstract

The invention can be used in magnetic starter designs. The purpose of the invention is to increase the switching wear resistance by reducing the transition resistance. Due to the fact that holes are made in the trough-like base into which the protrusions of the copper plate enter, the current passes from one contact plate to another through the contact zone of the steel trough with the copper plate and most of it through the copper plate, because its electrical resistivity is lower than that of a steel base. 1 s.p. f-ly, 3 ill.

Description

The invention relates to electrical engineering, namely, to electrical switching devices, for example, it can be used. 6 designs of starters, contactors

Compound contact bridges are known, consisting of a steel trough-like base with silver-containing contact plates, and attached from the inside or outside of this base to its bottom of a copper plate to increase the electrical conductivity of the movable contact bridge. The trough-like shape of the bridge creates the required rigidity with a minimum weight, which is important to reduce the contact vibration time, and the arcing steel horns welded from the sides to the trough-like base of the bridge provide quick arc exit from the contact plate, reducing wear of the contact plates.

When attaching a copper plate to the outside of a steel base between silver-containing contact plates.

attached to the steel base, a large transition resistance is obtained due to the small contact surface between the side (end) surfaces of the silver-containing plates and the copper plate due to their thickness, which leads to heating and intensive wear of the silver-containing plates. In addition, the small thickness of the copper plate and silver-containing pads causes technological difficulties in ensuring a good contact transition.

The aim of the invention is to increase the switching wear resistance of the contact bridge by reducing the transition resistance.

This goal is achieved by the fact that in the contact bridge, containing a steel trough-like base, a copper plate running along its bottom and fixed thereon by soldering on the inside, and silver-containing contact pads fixed along the edges of the bottom

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baths from the outside, the specified base is made with two through holes located in the place of fastening of the contact plates, and the copper plate is equipped, respectively, with two protrusions entering these holes.

In order to simplify the manufacture of such a contact bridge on a steel trough-like base from an external wall, recesses are made around these holes in the fastening zone by soldering silver-containing contact plates, which are filled with solder during soldering.

The technical nature of the proposed solution is as follows.

Due to the fact that the base is made with through holes in the place of fastening of the contact plates, a1 a copper plate attached to the bottom of the trough-like base from the inside is provided with protrusions that can be extruded and which go into the specified through holes, silver-containing contact the pads attached to the base are in direct contact with the copper plate, which has a significantly higher electrical conductivity compared to a steel base, as a result of which However, the transition resistance and heat loss in the contact bridge are reduced and, therefore, the wear of silver-containing plates is reduced and the switching wear resistance of the contact bridge is increased. Making recesses on the steel base at the point of attachment of the silver-containing contact pads by soldering, which are filled with solder during the soldering process, further reduces the transition resistance and simplifies the manufacture of the contact bridge.

On Fig, 1 presents the contact bridge assembly; figure 2 - steel trough-like base of the contact bridge; Fig. 3 is a copper plate fixed inside a steel trough-like base of a contact bridge.

Presented in FIG. The 1-3rd contact bridge consists of a steel trough-like base 1. along the edges of which, at the junction with the silver-containing contact pads 2. holes 3 are made. Around the holes 3 of the trough-like base 1 there are recesses 4.

Inside the trough-like base 1, a copper plate 5 is fixed by soldering, the protrusions of which 6 extend into the holes 3 of the trough-like base

At the edges of the trough-like base, silver-containing contact plates 2 are fastened by brazing. Due to the recess 4, on the trough-like base 1, soldering is well held in the area of connection with the silver-containing contact plate by soldering, filling the recess 4.

During the operation of the proposed contact bridge, an electric current of one contact plate 2 passes to the copper plate 5 through its protrusion b, then along the copper plate through another protrusion to the other contact plate.

Another current path from one contact

5 pads 2 along the trough-like steel base 1 to another contact pad through the contact zone of the steel trough with the contact pad 7. In view of the fact that the electrical resistivity

0 of copper (0.0162-0.0175) is much less than the electrical resistivity of steel (0.1-0.15), then most of the current passes through the copper plate 5.

Compared to the prototype - contact-

5th bridge, in which the current transfer from the contact plate to the copper plate occurs through the thickness of the steel trough-like base, with the proposed contact bridge direct

0 electrical contact of the silver-lining pad with a copper plate provides significantly lower transition resistance, lower losses and, consequently, less electrical wear

5 silver-containing contact pads. As the results of tests on Siemens starters showed, TE the proposed contact bridge has a transition resistance of 5-10 times

0 less. Accordingly, contact transition losses and less heat and less wear on silver-containing contact pads are obtained. Therefore, to ensure the same

5 of the resource less silver is required than in the contact bridges of the prototype. According to a rough calculation, it is possible to save more than 1 kg of silver for each device, which, for example, with an annual volume of 500 tons

Claims (1)

0 PM 12 starters, in which the use of a bridge is proposed, will save 500 kg of silver. SUMMARY OF THE INVENTION 1. Contact bridge containing 5 is a steel trough-like base on which a copper plate is fixed on the inside and silver-containing contact plates are fixed on the outside, characterized in that. in order to increase the switching wear resistance by reducing the transition resistance, holes are made on the trough-like base in the place of fastening of the contact plates, and protrusions are made on the copper plate so that they can enter these holes. 2 My preference is that it is designed to be recessed with concentric holes on the outside of the trough base to simplify manufacture // J FIG. Shchig.Ј