JPS61190822A - Switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a switch for switching on and off current, and particularly to arc suppression.

[Conventional technology]

FIG. 3 is a partial sectional view showing an example of a conventional switch.

Note that since the conventional switch is symmetrical, one side of the switch is shown in cross section. (1) is a mounting base made of plastic, (2) is a fixed iron core laminated with silicon steel plates on the mounting base (1), (3) is a fixed iron core (2) K is installed opposite, and is also made of silicon steel plates. (4) is an operating coil that applies a driving force to attract the movable core (3) and fixed core (2) against a tripping spring (not shown) K; A crossbar made of plastic and having a square window, at its lower end holds a moving core (3).

(6) is a plate-shaped movable contact inserted into the corner window of the crossbar (5) and held by a push spring (7)K; (6A)
) is a movable contact provided on this movable contact (6), (8
) is a fixed contact provided opposite the movable contact (6) and conducts current flow, (8A) is a fixed contact provided on the fixed contact (8), (8C) is a child screw, and αQ is a fixed contact. The base on which the contactor (8) is attached, αη is a cover that covers the upper surface of the electromagnetic contactor.

The conventional switch is constructed as described above. For example, when the operation coil (4) is demagnetized, the movable iron core (3) is separated from the fixed iron core (2) by a tripping spring (not shown) K, and the crossbar (5) is separated from the fixed iron core (2). ) is also in the state shown in Figure 3, and the fixed contact (8A)
and the movable contact (6A) are opened and an arc α■ is generated between the fixed contact (8A) and the movable contact (6A), but the arc is extinguished at the current zero point and the current is cut off.

[Problem that the invention seeks to solve]

In the conventional switch as described above, the movable contact (6) is formed in a plate shape, so the movable contact (6) moves toward the fixed contact (8), and the movable contact (6A) Fixed contact (
8A), the movable contact (6A) bounces and an arc is generated, and both contacts (6A) and (8A) are consumed by the generation of this arc.

Also, during the breaking operation when the movable contact (6A) separates from the fixed contact (8A), an arc is generated and both contacts (6A) are separated.

(8A) is consumed. Furthermore, there is a problem in that harmful high-temperature arced gas is released to the outside due to the generation of the arc.

This invention has been made to solve these problems, and the object is to obtain a switch that can suppress the generation of arc and reduce contact wear. [Means for solving the problems] The switch according to the present invention is configured to include an arc suppression circuit including a fixed contact inch of the movable contact and an ignition circuit in which a DC power source is connected in series.

[Effect]

In this invention, during the closing operation of the switch, the switch is closed before the movable contact contacts the fixed contact, so that after the movable contact contacts the fixed contact, the contact current flowing through the thyristor is transferred to the movable contact. The arc that occurs when the movable contact moves away from the fixed contact due to bounce is extinguished as the contact current is commutated to the thyristor again. The on/off switch opens only after it moves away from the fixed contact.
The arc that occurs when the moving contact separates from the fixed contact is
The contact current flowing through the movable contact and the fixed contact is commutated to the thyristor side and disappears.

〔Example〕 .

1st! 1 is an electric circuit element showing one embodiment of the present invention. Since the embodiment of the present invention is simply an arc suppression circuit added to the conventional switch described above, only seven main parts are shown in FIG. In the figure, (to) is a tri-book which is a bidirectional three-terminal thyristor, and both earths of the tri-book (2) are connected between a pair of fixed contacts (8) and (8). (lL is a resistor for setting the ignition current of the triac (to) to an appropriate value, α0 is a battery that is a DC power source to supply point @ current to the triac (to), α is not shown) This is an open/close switch that operates in conjunction with the crossbar.This open/close switch α→ is a movable contact (6
A) closes before contacting the fixed contact (8A), and operates in conjunction with the crossbar so that the movable contact (6A) opens after moving away from the fixed contact (8). (b) is the resistance α→ and the battery (
This is an ignition circuit in which the opening/closing switch (g) and the opening/closing switch (a) are connected in series. One terminal (13a) of the try book (2) and the gate G are connected like an ignition circuit.

In the switch configured as described above, the closing operation of the switch will first be described.

Before the movable contact (6A) contacts the fixed contact (8A) K, the opening/closing switch α leaf is closed. Then, the ignition current flows through the gate of the triac ÷ i1 → and the triac (
) is turned on, and contact current first flows between both terminals of the triac (2), then the movable contact (6A) contacts the fixed contact (8A), and the fixed contacts (8A), (8A)
A contact current is commutated between them. This is a triac (to)
This is caused by the fact that the resistance between the terminals of is on the order of mΩ, whereas the contact resistance between the movable contact (6A) and the fixed contact (8A) is on the order of μΩ. Here, when the movable contact (6A) bounces and separates from the fixed contact (8A), an arc is generated, but since the resistance of this arc is significantly higher than the resistance between the terminals of the triac, the movable contact (
The contact current flowing between the fixed contact (8 A) and the fixed contact (8 A) is commutated to the triac (LIK), and the arc between the fixed contact (8 A) and the movable contact (6 A) is extinguished.

When the movable contact (6A) contacts the fixed contact (8A) again, the contact current that was flowing through the triac (LIK) is transferred to the contact (6A).
A) The current is commutated to the (8A) side. During the closing operation of the movable contact (6A), the bounce phenomenon usually occurs multiple times, so the above operation is repeated multiple times, and after the bounce phenomenon ends, even if the triac (to) is fired, the triac ( 2) Only a small amount of contact current flows in K, and almost all of the contact current flows to the contacts (6A) (8A).

Next, the case of the breaking operation of the switch will be explained.

When the movable contact (6A) separates from the fixed contact (8A), an arc is generated between the movable contact (6A) and the fixed contact (8A), but at this time the open/close switch (2) is not yet open. Since the triac (2) is in a conductive state, the contact current that was flowing between the movable contact (6A) and the fixed contact (8A) is commutated to the triac (2)K, and the movable contact (
6A) and the fixed contact (8A) is extinguished. Then, in the process of moving the movable contact (6A) away from the fixed contact (8A), the on/off switch (b) is opened, and the ignition current no longer flows through the triac (to) GK.
The interruption of the contact current is completed when the contact current reaches the zero point.

Since the arc generated during the closing and breaking operations of the switch can be suppressed, the contact wear of the movable point (6A) and the fixed contact (8A) is significantly reduced.

FIG. 2 is an electrical circuit diagram showing another embodiment of the invention. In this embodiment, two reverse blocking three-terminal thyristors (13A), (13
B) is used. two thyristors (13A),
(13B) are connected in parallel between the pair of fixed contacts (8) and (8) so that their polarities are opposite to each other. And both thyristors (13A).

(13B), one anode side terminal (13A) (1
3B) and each gate G are connected by ignition circuits αη, (B) similar to those in the embodiment described above. The function of this embodiment is that two thyristors (13A), (13A) and (13A)
Since B) merely replaces the triac K in the above-described embodiment, a description of its operation will be omitted. However, when the contact current is direct current, it is sufficient to open and close one switch (c).

Note that the open/close switch α→ is designed to close before the movable contact (6A) comes into contact with the fixed contact (8A), and to open after the movable contact (6A) is separated from the fixed contact (8A).
The opening/closing of the on/off switch (a) is performed by a delay circuit and a relay (K) provided between the start switch and the on/off switch (b), which turn on/off the energization to the operation coil. In other words, when the start switch is closed and the switch is turned on, the relay is activated, the relay contact becomes conductive, and the switch a→
When the crossbar closes, the crossbar moves and the movable contact (6A)
contacts the fixed contact (8A). At this time, the open/close switch (2) closes at the same time as the start switch because the relay is small, but the movable contact (6A) contacts the fixed contact (8A).

Since the handle and container have a large capacity, it closes a little later after the start-up switch closes. Therefore, the open/close switch αQ is a movable contact! (6A) Force i must be closed before it comes into contact with the fixed contact (8A). On the other hand, when the starter switch opens and the switch is cut off, the relay operates double, causing the relay contact to become non-conducting and causing a delay circuit. As the opening/closing switch α opens with a delay, the crossbar moves and the movable contacts (6 contacts) move away from the fixed contact (8A). At this time, the opening/closing switch (2) opens after the movable contact (6A) is separated from the fixed contact (8A) by the delay circuit.

In all of the above embodiments, a battery is used as the ignition power source for the triac (2), the iristor (13A), and (13B), but as long as it is a DC power source, it is not limited to a battery (g), and other power sources may be used. Of course, it is also possible to use

Further, in each of the above embodiments, the present invention is applied to a switch having a two-point disconnection point, but it goes without saying that the present invention can be applied to a switch having a one-point disconnection point. .

〔Effect of the invention〕

As explained above, the present invention includes an arc suppression circuit including a circuit connected between contacts that conduct when a movable contact contacts a fixed contact, and which accelerates or delays the closing or breaking operation of a switch. The contact current is commutated between the movable contact and fixed contact side and the thyristor side, and when the movable contact separates from the fixed contact, the arc generated at # is commutated. Since the arc is suppressed so that it disappears, it is possible to significantly reduce contact wear due to arcing that occurs during the closing and breaking operations of the switch.
Furthermore, there is an effect that harmful arced gas can be prevented from being released to the outside.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit diagram showing one embodiment of the present invention, Fig. 2 is an electric circuit diagram showing another embodiment of the invention, and Fig. 3 is an electric circuit diagram showing another embodiment of the invention.
The figure is a partial sectional view showing a conventional switch. In the figure, (6) is a movable contact, (6A) is a movable contact, (8) is a fixed contact, (8A) is a fixed contact, (6) is a try book (thyristor), (13A), (13B)
is a reverse blocking three-terminal thyristor, α is a resistor, (to) is a battery (DC power supply), (2) is an open/close switch, αη is an ignition circuit, and G is a gate. In each figure, the same reference numerals indicate the same or equivalent parts.O Agent: Patent Attorney Mitsuro Kimura Figure 1, 2vl Procedural Amendment (Voluntary) December 9, 1985

Claims (5)

[Claims] (1) In a switch comprising at least one fixed contact to which a fixed contact is joined, and a movable contact to which a movable contact that makes contact with and separates from the fixed contact is joined, the movable contact is connected to the fixed contact. A thyristor connected between the contacts conducts when they make contact, and the movable contact closes before it comes into contact with the fixed contact,
A switch comprising an arc suppressing circuit including an opening/closing switch that opens after the movable contact is separated from the fixed contact, and an ignition circuit for the thyristor connected in series with a DC power source. (2) The switch according to claim 1, characterized in that when the movable contact contacts the fixed contact, conduction occurs between the two fixed contacts. (3) The switch according to claim 1, characterized in that when the movable contact contacts the fixed contact, electrical conduction occurs between the movable contact and the fixed contact. (4) The switch according to claim 1, 2, or 3, wherein the thyristor is a bidirectional three-terminal thyristor. (5) The switch according to claim 1, 2, or 3, wherein the thyristor is two reverse blocking three-terminal thyristors connected in parallel with opposite polarities.