SU1324597A3 - Overload protection switch for sealed miniature electric motors - Google Patents

Abstract

The invention relates to an overload protection circuit breaker for encapsulated miniature electric motors, especially for miniature electric motors used in motor vehicles, for example windscreen wiper (headlight wiper) motors. Such an overload protection circuit breaker has the object of protecting an encapsulated miniature electric motor against damage caused by overheating, in that the motor circuit is interrupted by rapid tripping in the event of dangerous overloading resulting in the common influence of the current flowing through the motor windings and the temperature which stabilises inside the motor, without noticeably interfering with motor operation in the permitted temperature range, and furthermore that the circuit is automatically made (closed) again once the system has cooled down. The object which is placed is achieved as a result of the further development of the overload protection circuit breaker described in the introduction to the description, in that, according to the invention, a normally-closed contact and two interacting moving contacts, which are provided with bimetallic contact tongues, are arranged in the protection circuit breaker, one of the moving contacts being a so-called acceleration contact with a stop element, and the other contact being a spring-loaded rapid-tripping contact.

Description

holder (BK) 5 with a movable contact 6. Between BK 5 and recess 7, made in the housing, there is a reversing spring 8. The switching contact consists of BK 10c with double contact 11. The movable end of BK 10 is bent, forming an emphasis, fixed contact 12 is placed on the connecting terminal 3. With an increase in the current flowing through the protected element, the BC 5 bends, as a result of which, first contact A and then

The invention relates to electrical engineering, in particular, to overload protection switches for sealed electric motors, in particular, miniature electric motors used in motor vehicles. .

The aim of the invention is to increase the reliability of the protection of the motor from levrozh and to ensure the normal operation of the motor in the allowed temperature mode.

Figure 1 shows schematically the overload protection switch, in the initial position; fig 2 - polo

elements live during interruption

electrical circuit; in FIG. 3, the same after interruption of the electric circuit.

The overload protection switch contains a body 1 of synthetic material with a key (not shown). By means of the connecting terminals 2 and 3 fixed in the housing 1, the switch of the switch is connected to the circuit of the protected motor (not shown).

At the connecting terminal 2, at point 4, one end of the bimetallic contact holder 5 is fixed, at the other end of which there is a movable contact 6, which is a transitional contact. A biased spring 8 is located between the movable end of the bimetallic contact holder 5 and the recess 7 in the housing. The switching contact consists of the bimetallic contact holder 10 with double contact 11 fixed on the connecting terminal 3 at point 9 and the movable end of the bimetallic contact holder blows behind contact 6 and contact 11 opens with contact 12. With the further flow of current, the BC 10 heats up and deflects towards the fixed contact 12, and contact b under the action of the reversible spring 8 instantly opens 11. Due to the contact bend 10 BC 11 reliably contact with the contact 12 is closed than razmshanie provides reliable electrical circuit. 1 h, para. f-ly, 3 ill.

R

five

0

From 5

bodies 10 to restrict the movement of the double contact 11 are bent to form a stop. At the connection terminal, 3 is fixed contact 12,

The overload protection switch works in the following 1M way.

In the initial position, the contact 6 and the double contact 11 are pressed against the fixed contact 12 by means of a reversible spring 8. The bimetallic holder 5 is pre-bent in, the closing position of the contact 6 with contact II. In this position, the electrical circuit of the protected object passes through the connecting terminal 2, the bimetallic contact-holder 5 with the contact 6, the DOUBLE contact 11, the contact 12 and the connecting terminal 3. When the current flowing through the stirring element increases, its thermal effect causes bending bimetallic contact holder 5, as a result of which contact 4 first follows contact 6, and contact 11 opens with fc contact 1. In this position the electrical circuit passes through terminal 2, the bime 5-pin contacting device 5 with contact 6, double contact 11, bimetallic contact holder 10 and connection terminal 3, With further current flow, the bimetallic contact holder heats and deflects towards the stationary contact 12, and contact 6 under the action of reversible spring 8 instantly opens with pin 11. I switch

The contacting contact 11 due to the bending of the bimetallic contact holder 1 is reliably closed with the contact 12. Thus, a reliable extension of the electric circuit occurs. After elimination of the malfunction, the bimetallic contact holders 5 and 10 begin to cool and return to their original position.

Claims (2)

1. Overload protection switch for sealed miniature electric motors, in particular for miniature electric motors used in motor vehicles, mounted inside a miniature electric motor and containing a connecting terminal on which a fixed contact is located, another connecting terminal connected to one end a bimetallic contact holder with a movable contact at the other end and a reversible spring, one end of which rests O 5 0 5 c in the recess of the housing, and the other end is adjacent to the movable end of the bimetallic contact holder, characterized in that, in order to increase the protection of the motor against overload and to ensure the normal operation of the motor in the permitted temperature mode, it is provided with an additional bimetallic contact holder, at the movable end of which a double contact is placed, with the other end of the additional bimetallic contact holder connected to the connecting terminal on which the stationary is placed minutes contact, double contact disposed between the movable and fixed contact, and further movement of the bimetallic contact holder limited focus. 2. A switch according to claim 1, characterized in that the stop is formed by the bending of the movable end of the additional bimetallic contact holder located behind the fixed contact. 777, Y / 7 / jig // xK //////// {// 7 ftsg.z Editor Y. Sereda Compiled by S. Gordon Tehred N.Glushchenko 2976/59 Circulation 698 Subscription VNISTI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Design, 4. Proofreader A. R1pyin