RU2235381C2 - Contact arc-suppressing device - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: device has arc-suppressing chamber, current-carrying buses whose longitudinal symmetry axes lie in one plane, bridge contact system whose movable contacts are arranged in the ports of the crosspiece along the longitudinal axes of symmetry of the current-carrying buses.. At least one permanent magnet is mounted directly on the crosspiece under the bridge of the movable contacts providing the total vector of magnetizing of the permanent magnet to be oriented perpendicular to the axis of symmetry of current-carrying buses and the bridge of movable contacts.

EFFECT: enhanced reliability and simplified design.

1 cl, 7 dwg

Description

The invention relates to devices for switching electrical circuits of direct current and can be used in the construction of relays, contactors and other switching devices of automation, control and protection.

It is known [1] contact-extinguishing device of a contactor (Fig. 1, 2), containing prismatic current-carrying buses 1 and 2 with fixed contacts 3 and 4 fixed on them, a movable contact bridge 5 installed in the window of the crosshead 6, providing two breaks in the circuit current, arc chamber 7 and permanent magnets 8 and 9. The longitudinal axes O ₁ -O ₁ , O ₂ -O _2, respectively, of tires 1 and 2 (Figs. 1, 2) lie in one plane, the trace of which in Fig. 2 is designated as I _P -I _P The longitudinal axis O ₃ -O _{3 of the} contact bridge 5 is perpendicular to the longitudinal axes O ₁ -O ₁ and O ₂ -O _{2 of the} tires 1 and 2. Permanent magnets 8 and 9 are located at the faces of the respective tires, opposite the faces on which the fixed contacts 4 and 3. The contact-extinguishing device is mounted with steel screws 10, 11 on the ferromagnetic bracket 12 of the drive electromagnet.

A disadvantage of the known [1] device is the inefficient use of energy of permanent magnets. This is due to the fact that as the fixed contacts 3 and 4 are removed during the current shutdown, the magnetic induction at their working surfaces decreases, which slows down the movement of the reference points of the electric arc on the fixed contacts 3 and 4. This leads to an increase in the temperature of the contact points and an increased wear, reduces the switching ability of the contact-arrester device. These phenomena are compounded by the fact that a large proportion of the magnetic flux Ф _{П of} permanent magnets is closed (Ф _П2 ) through a magnetic shunt, the functions of which are performed by screws 10, 11, and the bracket 12 of the magnetic circuit of the electromagnet. Another disadvantage is the use of two permanent magnets, which increases the cost of the device.

The closest in technical essence to the claimed device is a contact-arrester device [2] (Fig.3, 4), containing tires 1 and 2 of rectangular cross-section, the longitudinal axis of which lie in the same plane, fixed contacts 3 and 4, fixed at the ends transitional busbars of the current-carrying circuit, a contact bridge 5, the longitudinal axis of which lies in a plane passing through the longitudinal axes of the tires 1 and 2, a traverse 6, on which a bridge 5 is installed, an arcing chamber 7, prismatic permanent magnets 8 and 9 installed opposite the bridge 5 in the niches of the arcing chamber 7 so that the resulting magnetization vector is directed along the longitudinal axis of the elements 1, 2, 3 of the current-carrying circuit.

The disadvantage of this device is the lack of reliability due to the fact that, depending on the position of the arc (its cross section in figure 3 is blackened), which is determined by the random nature of the electrodynamic force P _ed acting on the arc column, it can be directed either to traverse 6 (point B) or into the working cavity of chamber 7 (point C). The transverse magnetic field at the location of the electric arc in the structure is small, since part of the field (approximately half) is closed in planes parallel to the longitudinal plane (a plane passing through the longitudinal axes of current-carrying elements). As the distance between the fixed contacts 3, 4 and the bridge 5 increases during the disconnection of the current, the intensity of the transverse magnetic field acting on the electric arc decreases. The design also uses two permanent magnets, which increases costs in the production process of a contact-arcing device.

The technical result of the claimed invention is to increase reliability, simplify the device and reduce costs in the process of its production.

The technical result is achieved by the fact that in the contact-arrester device containing the arrester, current-carrying tires, the longitudinal axis of symmetry of which lie in the same plane, a bridge contact system, movable contacts of which are placed in the windows of the traverse along the longitudinal axis of symmetry of the current-carrying busbars, at least one permanent magnet, which is mounted directly on the traverse under the bridge of movable contacts so that the resulting magnetization vector of the permanent magnet is oriented perp perpendicular to the longitudinal axis of symmetry of the current-carrying buses and the bridge of movable contacts, and in a multi-pole device with an odd number of poles, the permanent magnets are alternated through the pole, and the conclusions of the current-carrying buses of the neighboring poles are connected by current-carrying jumpers, as well as in the multi-pole device with an even number of poles, the adjacent poles of the constant poles facing each other by poles of the same name, and the bus terminals of adjacent poles are connected by current-carrying jumpers.

The essence of the invention lies in the fact that the placement of a permanent magnet directly on the traverse under the contact bridge so that the resulting magnetization vector is directed perpendicular to the longitudinal axis of symmetry of the current-carrying busbars and the bridge of movable contacts, allows for effective transverse magnetic blast throughout the contact selection solution when they open at half the cost of material used to make permanent magnets.

Figure 5, 6 schematically shows the design of the contact arcing device. It contains current-carrying tires 1, 2 with fixed contacts 3, 4 fixed to them, a contact bridge 5. The longitudinal axes O ₁ -O ₁ , O ₂ -O ₂ , O ₃ -O _3, respectively, of elements 1, 2, 5 of the current-carrying circuit lie in the longitudinal plane of symmetry of the structure, the trace of which is indicated in Fig.6 as I _prod -I _prod . The contact bridge 5 is installed on the traverse 6. The extinction of the electric arc occurs in the chamber 7. The permanent magnet 8 is installed directly on the traverse 6 under the contact bridge 5 (Fig. 5). In this case, the permanent magnet 8 is located so that the resulting magnetization vector is directed perpendicular to the longitudinal plane of symmetry (I _prod- I _prod ) and lies in the transverse plane of symmetry (I _P -I _P ) of the contact-extinguishing device.

The proposed device operates as follows. When you disconnect the switching device, the crosshead 6 with the contact bridge 5 are moved in the direction of y (figure 5). After selecting a dip, when the contacts diverge in the intercontact breaks, arcs D1 and D2 arise, which at the entire stage of the traverse movement (when choosing the contact solution) intersect with transversely directed lines of magnetic induction created by a permanent magnet 8 magnetized along the transverse plane I _П -I _{П of} symmetry of the structure . Each of the arcs D1 and D2 is _{affected by the} electric force R _edu , which intensively moves the column of the arc and its reference points along the surface of the contacts into the arcing chamber 7, where it is finally extinguished.

Placing a permanent magnet under the bridge on the traverse provides effective blasting in the transverse magnetic field during the extinction of the electric arc, increasing the wear resistance and switching ability of the apparatus. The use of one permanent magnet, which suppresses electric arcs in two breaks of the contact system, allows to reduce the cost of manufacturing the apparatus.

An additional reduction in the cost of a multi-pole device with an odd number of poles is ensured by the installation of a permanent magnet in traverses alternating through the pole and connecting the terminals of the current-carrying buses of neighboring poles with current-carrying jumpers, providing the opposite direction of the current flowing in the poles of the device (Fig. 7).

Sources of information

1. Catalog 07.13.05-02 Electromagnetic contactors of the KM series.

2. Catalog 07.13.03-97 Contactors electromagnetic series MK.

Claims (3)

1. Contact-arrester device containing an arrester, current-carrying tires, the longitudinal axis of symmetry of which lie in the same plane, a bridge contact system, movable contacts of which are placed in the traverse windows along the longitudinal axis of symmetry of the current-carrying tires, at least one permanent magnet, different in that the permanent magnet is mounted directly on the traverse under the bridge of movable contacts so that the resulting magnetization vector of the permanent magnet is oriented perpendicular to longitudinal axis of symmetry of the busbar bridge and moving contacts. 2. The device according to claim 1, characterized in that in a multi-pole apparatus with an odd number of poles, the permanent magnets are alternated through the pole, and the conclusions of the current-carrying buses of adjacent poles are connected by current-carrying jumpers. 3. The device according to claim 1, characterized in that in a multi-pole apparatus with an even number of poles, the adjacent poles of the permanent magnets face each other with the same poles, and the bus terminals of the adjacent poles are connected by current-carrying jumpers.

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