RU214432U1 - CONTACT-DETAIL REED - Google Patents

Abstract

The utility model relates to electrical engineering, in particular to switching technology, concerns the form of contact parts of magnetically controlled sealed contacts (reed switches) and can be used in their industrial production. The technical result consists in improving the quality of the contact part by eliminating the formation of burrs during its manufacture. A contact part of a reed switch, made of a ferromagnetic alloy, containing a section of circular cross section passing one into another and a flat section of equal thickness with a rectangular end, in which symmetrical chamfers are made at the upper and lower boundaries of the end at an angle of 25-30 degrees to the longitudinal axis of the contact parts, while the width of the remaining central part of the end is 0.10-0.25 mm. 2 ill.

Description

The utility model relates to electrical engineering, in particular to switching technology, concerns the form of contact parts of magnetically controlled sealed contacts (reed switches) and can be used in their industrial production.

For the manufacture of contact parts of reed switches, a wire of round cross section is used, made of a ferromagnetic material, the blanks of which are given the necessary shape by machining.

When punching and cutting wire blanks, end burrs appear, which are a kind of local surface defects of the formed metal boundaries. The formation of burrs occurs due to plastic deformation of the material of the contact parts ahead of the stamping or cutting zone.

Burrs worsen the conditions for closing the reed switch and must be eliminated. For these purposes, in the production of reed switches, vibration processing of contact parts in an abrasive medium and their electrolytic etching are used. These operations are characterized by high labor intensity, which leads to an increase in the cost of reed switches.

From the existing prior art known contact-detail of the reed switch with a flat working surface [GOST3884-77. Contact details for electrical switching devices. Design and dimensions. - Gosstandart of the USSR. - Date of introduction 01/01/1978]. However, contact details of this form cannot be directly used in the manufacture of reed switches due to the complexity of forming their junctions.

From the existing prior art known contact-detail of the reed switch, the flat working part of which is directly involved in switching current, made in the form of an isosceles triangle [SU 1626477 A1, H05K 13/00, publ. 07.02.91].

The disadvantage of this technical solution lies in the fact that in the manufacture of such a contact detail by known methods in the area of the top of its triangular zone, metal sags and burrs will form.

From the existing prior art, a reed switch contact part made of a ferromagnetic alloy is known, containing a section of circular cross section passing one into another and a flat section of variable thickness with a rectangular end [RU 2170975, H01H 1/66, publ. July 20, 2001].

The disadvantage of the design of this contact part is that in its manufacture it is necessary to use stamps of complex shape, and burrs will also form at the end of the flat part.

Closest to the claimed technical solution is the contact part of the reed switch, made of a ferromagnetic alloy, containing passing one into another section of circular cross section and a flat section of equal thickness with a rectangular end [SU 1061184, H01H 1/66, publ. 15.12.83].

The disadvantage of this technical solution lies in the fact that during the manufacture of such a contact part, burrs are inevitably formed on its end face.

The task to be solved by the claimed technical solution is to reduce the cost of manufacturing reed switches by eliminating burrs at the end of the contact part during its stamping.

This problem is solved by the fact that in the contact part of the reed switch, made of a ferromagnetic alloy, containing a section of circular cross section passing one into another and a flat section of equal thickness with a rectangular end, symmetrical chamfers are made at the upper and lower boundaries of the end at an angle of 25-30 degrees to the longitudinal axis of the contact part, while the width of the remaining central part of the end is 0.10-0.25 mm.

The choice of the shape of the chamfers of the contact part is due to the following circumstances. When the angle of inclination of the end chamfers is less than (equal to) 25 degrees, an uneven gap between the contact parts is created in the reed switch and thereby the area of their working area involved in the switching processes is reduced. This circumstance negatively affects the durability of reed switches.

With an angle of inclination of the end chamfers greater than (equal to) 30 degrees, the requirements for the accuracy of manufacturing a molding die increase, taking into account the small dimensions of the contact part.

The use of the width of the central part of the end face used in the production of the size range of contact parts equal to (smaller) 0.10-0.25 mm leads to the formation of burrs in this zone in the form of sagging that extend beyond the boundaries of the end face.

The technical result of the utility model is to improve the quality of the contact part by eliminating the formation of burrs during its manufacture.

The positive effect of using the proposed form of the contact part is due to the fact that the formation of burrs is completely excluded during its manufacture, which makes it possible to reduce the cost of manufacturing reed switches.

The essence of the utility model is illustrated by the drawings, where in Fig. 1 shows the design of the proposed contact piece with chamfers, and Fig. 2 - photographs of a contact piece with a rectangular flat end.

In the manufacture of a contact part of the claimed shape from the original wire, a combined stamp is used. In the process of continuous operation, sections (blanks) of wire of a given length are fed into the stamp in turn. At the same time, at the end of each such workpiece there are burrs that are formed during the previous cutting of the wire.

In the stamp, in one technological cycle, the manufacture of the contact part is carried out, including the molding of its flat part, the formation of symmetrical chamfers on the upper and lower boundaries of the end face, and the separation of the remaining cylindrical part of the contact part from the wire. During the formation of chamfers, the burrs are pressed into the surface of the end face of the contact part (Fig. 1).

If chamfers are not formed during stamping, then burrs inevitably remain at the end face of the manufactured contact parts (Fig. 2).

As an example, contact parts were made with a flat section thickness of 0.29 mm. At the same time, the width of the central part of their end was 0.10 mm, and the angle of inclination of the chamfers was 25 degrees. The resulting contact parts without additional operations associated with the processing of their ends were used to manufacture reed switches.

The use of contact details of the proposed form allows to reduce the cost of manufacturing reed switches.

Claims (1)

A reed switch contact part made of a ferromagnetic alloy, containing a section of circular cross section passing one into another and a flat section of equal thickness with a rectangular end, characterized in that symmetrical chamfers are made on the upper and lower boundaries of the end at an angle of 25-30 degrees to the longitudinal axis contact details, while the width of the remaining central part of the end is 0.10-0.25 mm.

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