RU214912U1 - Magnetic contactor - Google Patents

Abstract

The technical solution relates to a magnetic contactor with an arc chute for rapid extinguishing of the electric arc during the shutdown process. The technical result is to reduce the weight and dimensions of the magnetic contactor with a simultaneous increase in its reliability. The technical result is achieved by the fact that the magnetic contactor includes a housing containing movable and fixed contacts, having contact elements for contact with each other, a drive configured to move the movable contact to establish an electrically conductive connection between the movable and fixed contacts and to disconnect the movable and of fixed contacts, the first area of opening and closing of the contact elements of the movable contact and the first fixed contact, the second area of opening and closing of the contact elements of the movable contact and the second fixed contact, magnets configured to create multidirectional constant magnetic fields in the first and second areas for exposure to magnetic force fields on an electric arc that occurs between the contact elements of the movable and fixed contacts when they are opened, an arc chute designed to extinguish electric arcs and containing at least that is, two horns on each side, the arc chute is fixed in the housing above the first and second areas, the horns of the arc chute are directed downward towards the divergence and closure of the contact elements of the movable and fixed contacts and are configured to move the electric arc into the arc chute, and along at least one horn on each side of the arc chute is connected to the potential of the fixed contacts. 1 w.p. f-ly, 7 ill.

Description

The technical solution relates to a magnetic contactor with an arc chute for rapid extinguishing of the electric arc during the shutdown process. The proposed electromagnetic contactor is not polarized, therefore it can be used in both direct and alternating current circuits.

State of the art

From the prior art, RF patent No. 2581049, a switch with arc chutes is known. The switch contains two separate fixed contacts with two contact areas and at least one movable electrically conductive bridge contact with two second contact areas, four lamellar permanent magnets, two magnets of different polarities located opposite each other to create an essentially constant magnetic field (M) on section of the first and second contact areas for the impact of magnetic force (F) on the electric arc that occurs between the first and second contact areas when the off state is established, two arc chambers for extinguishing electric arcs. The movable bridge contact contains two bridge plates, which, for extinguishing electric arcs with a second current direction opposite to the first current direction, pass from the bridge contact along the bridge contact movement axis (BA) to the third and fourth arc chutes. However, this design has several disadvantages:

Four bulky arc chutes significantly increase the weight and dimensions of the circuit breaker;

To arrange all the parts in the circuit breaker, the lengths of the guide plates are increased, thereby increasing the time for moving the arc to the arc chutes, i.e. its burning time. This causes more local heating and can lead to thermal damage (wear) of the contact groups, thereby reducing the reliability of the circuit breaker;

The presence of four plate magnets along the edges of the switch also increases its dimensions.

The technical problem solved by the claimed utility model is to reduce the mass and dimensions of the magnetic contactor with a simultaneous increase in reliability.

The technical result is a reduction in the mass and dimensions of the magnetic contactor with a simultaneous increase in reliability.

The technical result is achieved by the fact that the magnetic contactor includes a housing containing movable and fixed contacts, having contact elements for contact with each other, a drive configured to move the movable contact to establish an electrically conductive connection between the movable and fixed contacts and to disconnect the movable and fixed contacts, the first area of opening and closing of the contact elements of the movable contact and the first fixed contact, the second area of opening and closing of the contact elements of the movable contact and the second fixed contact, magnets configured to create multidirectional constant magnetic fields in the first and second areas for the impact of force magnetic field on an electric arc that occurs between the contact elements of the movable and fixed contacts when they are opened, an arc chute designed to extinguish electric arcs and containing at least pe two horns on each side, moreover, the arc chute is fixed in the housing above the first and second areas, the horns of the arc chute are directed downward towards the divergence and closure of the contact elements of the movable and fixed contacts and are made with the possibility of moving the electric arc into the arc chute, and along at least one horn on each side of the arc chute is connected to the potential of the fixed contacts.

The essence of the claimed technical solution is illustrated by the drawings of Fig.1-7, where

- figure 1 shows a General view of the contactor;

- figure 2 shows a General view of the arc chute;

- figure 3, 4 shows a General view of the arc chute using a current arc chute coil;

- figure 5, 6 shows the operation of the contactor when switching currents in positive sequence;

- figure 7 shows the operation of the contactor when switching currents of the negative sequence.

The figures show:

1 – contactor housing;

2 – auxiliary contacts;

3, 15 - fixed contact;

4, 5, 13, 14 - contact elements;

6, 12 - poles;

7, 9, 10, 11 - arcing horns;

8 - arcing block;

16 - arc chute;

17 – mobile contact;

18, 19 - permanent magnets;

21 - arc quenching coil;

22 - core;

23 - pole.

Below is an example of a technical solution.

The contactor consists of a housing 1 containing a drive, for example, an electromagnetic drive, which vertically moves a movable contact 17 containing contact elements 4,14. The contactor also contains fixed contacts 3,15 containing contact elements 5, 13. Auxiliary contacts 2 are attached to the body of the contactor 1 by assembly operations. The main circuit of the contactor consists of two fixed 3, 15 and one movable contact 17 having a bridge type design. Through the movement of the movable contact 17, the contact elements 4, 14 and 5,13 open or close, thereby switching the circuit. In this case, the contactor is not polarized, as it can operate with alternating current.

The arc chute 16 is mounted in the housing 1 above the contact elements 4, 14 and 5.13 by means of assembly connections, for example, fasteners 20. Permanent magnets 18, 19 are installed in the chamber on its sides, having alternating polarity "S", "N" perpendicular to them poles 6, 12 are attached, which form the distribution of the magnetic field in the zone of divergence and closure of the contact elements. The zone of opening and closing of contact elements 4 and 5 can be called the first area, such an area can include both the contact area 4-5 itself and part of the contacts 17 and 3 and, in fact, depends on the shape and dimensions of the pole 6 (see Fig. 1), which in turn are selected depending on the desired degree of influence of the magnetic field on the electric arc. Likewise, the opening and closing area of the contact elements 13 and 14 may be referred to as the second region. Thus, in the right and left parts (the first and second regions, respectively) of the arc chute, magnetic fields of different directions are formed by permanent magnets.

The arc chute also has arc horns 7,9,10,11 and an arc chute 8. In this case, there may be more horns, but an increase in their number will not affect the possibility of reducing the mass and dimensions of the magnetic contactor while increasing reliability. The horn 7 is connected to the potential of the fixed contact 3, and the horn 11 is connected to the potential of the fixed contact 15. The arcing block 8 can be made in the form of several plates, passing through which the arc is stretched, cooled and extinguished.

Reducing the number of arc chutes (an analog had two arc chutes, but now you can use only one with the same overall and weight characteristics) and the opportunity to reduce the arc burning time makes it possible to reduce the weight and dimensions of the contactor while increasing reliability.

An increase in reliability in the above design is also achieved due to the fact that during switching the contactor does not have critical tripping currents, since permanent magnets are used in the arc extinguishing system.

The arc chute 16 presented above operates effectively up to a voltage of 900 V. At voltages exceeding 900 V, one current coil 21 with a core 22 (see Fig. 3) can be introduced into the structure to maintain efficiency, located in the center of the chamber and potentially associated with horns 9, 10. The distribution of the magnetic field of the coil is made by poles 23 (see figure 4).

Thus, at high load voltages, the arc quenching coil 21 is switched on. As soon as the arc passes to the horns 9, 10, the magnetic field created by the coil 21 draws the arc into the left and right half of the arc chute, increasing the voltage of the interrupted arc. Also, the magnetic field of the coil acts on the arc on the horns and lengthens it in the arc chute, which helps to accelerate its extinction, and also helps to increase the voltage of the arc being switched off.

Due to the fact that the above design allows you to use only one arc chute (instead of two of the same for analogues), then when extinguishing the arc (over 900 V), only one current arc chute is used, which reduces the weight and size of the contactor.

The contactor with arc chute operates as follows.

Positive sequence current (Fig.5,6).

When the positive sequence current is turned off (a period of a positive half-wave) - opening contacts 3, 15, 17 - electric arcs that have arisen on contact elements 4-5 and 13-14 begin to move as shown in Fig.5,6.

In our proposed design (see figure 5), the arc 2 ¹ emerged between the contact elements 4-5 in the first region moves to the left under the influence of the magnetic field of the first region between the movable contact 17 and the fixed 4 (see arc 2 ² ). In the second region, the arc 1 ¹ , having the opposite direction of the current (see Fig.6) and which is affected by the magnetic field of the second region, the direction of which is opposite to the direction of the magnetic field of the first region, also moves to the left towards the horns 7 and 11.

In this case, the arc 2 ¹ goes out as soon as the arc 1 ¹ that has arisen on the contact elements 13-14 passes to the horns 7 and 11 (see the position of the arc 1 ³ in Fig.5,6) electrically connected to the fixed contacts 3, 15, respectively. Then the arc 1 ³ will pass to the elements 9,10, splitting into arcs 1 ⁴ -1 ⁹ . Ultimately, the arc is distributed between the arcing plates of the arcing unit 8.

Arc burn time 2²occupies little interval (with a total arc extinguishing time of 40-50 ms, the arc burning time about 3-6 ms) and during this time the arc moves over the contacts not causing their excessive local heating leading to thermal damage.

In this way, the proposed solution avoids the possibility of thermal wear of contact groups (increasing reliability), and at the same time it is more rational to use geometry of the arc chute (by reducing the number of arc chutes and the distance between the elements of the contactor), reducing the weight and dimensions device indicators.

Negative sequence current (FIG. 7).

When the reverse sequence current is turned off (negative half-wave period) - contacts 3, 15, 17 are opened, the electric arcs that have arisen on the contact elements 4-5 and 13-14 begin to move, as shown in Fig.7.

Since the direction of the current has changed, under the influence of the magnetic fields of the first and second regions, the arcs 2 ¹ and 1 ¹ move to the right.

In this case, the arc 1 ¹ goes out as soon as the arc 2 ¹ arising on the contact elements 4-5 passes to the horns 7 and 11 (see the position of the arc 2 ³ in Fig.7) electrically connected to the fixed contacts 3, 15, respectively. Further, the arc 2 ³ will pass to the elements 9,10, splitting into arcs 2 ⁴ -2 ⁹ . Ultimately, the arc is distributed between the arcing plates of the arcing block 8.

From the above examples, it follows that the contactor operates in any direction of current, i.e. can work with alternating current and is not polarized.

Claims (2)

1. A magnetic contactor including a housing containing movable and fixed contacts having contact elements for contact with each other, a drive configured to move the movable contact to establish an electrically conductive connection between the movable and fixed contacts and to disconnect the movable and fixed contacts, the first area of opening and closing of the contact elements of the movable contact and the first fixed contact, the second area of opening and closing of the contact elements of the movable contact and the second fixed contact, magnets configured to create multidirectional constant magnetic fields in the first and second areas for the effect of the magnetic field on the electrical an arc that occurs between the contact elements of the movable and fixed contacts when they are opened, an arc chute designed to extinguish electric arcs and containing at least two horns on each side, excellent characterized by the fact that the arc chute is fixed in the housing above the first and second areas, the horns of the arc chute are directed downward towards the divergence and closure of the contact elements of the movable and fixed contacts and are configured to move the electric arc into the arc chute, with at least one horn from each from the sides of the arc chute is connected to the potential of the fixed contacts. 2. Magnetic contactor according to claim 1, in which auxiliary contacts are fixed on the housing.

Images