JPH0228212B2 - DENJIHANPATSUSETSUSHOKUSHISOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic repulsion contact device used in circuit breakers and the like.

[Conventional technology]

This type of electromagnetic repulsion contact device has a fixed contact plate and a movable contact plate arranged in parallel so that the current direction is opposite, and when a large current such as a short circuit current flows,
A configuration in which an electromagnetic repulsion force is applied between both contact plates is common.

In circuit breakers and the like, the breaking performance of the movable contacts is improved by increasing the opening speed, and it is therefore desirable to increase the electromagnetic repulsion described above. To this end, in a typical configuration, countermeasures are taken such as lengthening the facing portions of both contact plates arranged in parallel or reducing the interval between both contact plates. However, in the former case, the opposing parts cannot be made long due to dimensional constraints of the circuit breaker, etc., or even if they can be made long, the circuit breaker etc. becomes large, and the latter has a limit in terms of withstand voltage. There are some problems.

[Purpose of the invention]

The present invention was made in view of the above reasons, and
The purpose of this is to create an electromagnetic repulsion contact that can generate a large electromagnetic repulsion force without increasing the size of the circuit breaker, etc., and without causing problems in terms of withstand voltage. Provide child devices.

[Disclosure of the invention]

An embodiment of the present invention applied to a circuit breaker will be described below with reference to FIGS. 1 to 3.

Reference numeral 1 denotes a stand and 2 a cover, which constitute a housing.

Reference numeral 4 denotes a fixed contact plate, which has a long piece and a short piece 5a forming a U-shaped part 5, the end of the long piece is connected to the power supply side terminal device 3, and the fixed contact 6 is connected to the tip of the short piece 5a.
has been established. This short piece 5a is supported by a support 7 provided on the table 1 in order to prevent it from bowing downward when electromagnetic repulsion, which will be described later, is applied.

Reference numeral 15 denotes a reversing arm, the base end of which is rotatably supported by a shaft 28.

Reference numeral 11 denotes a first movable contact plate, which is formed into an L-shape by a vertical piece 12 and a horizontal piece. The base end of this horizontal piece is rotatably supported by a support shaft 14 at the tip of the reversing arm 15 so as to face the short piece 5a of the fixed contact plate 4. Further, the first movable contact plate 11 is biased in a direction toward the short piece 5a of the fixed contact plate 4 by a spring 29 tensilely suspended between the shaft 16 provided at the intermediate portion of the first movable contact plate 11 and the intermediate portion of the reversing arm 15. ing.

9 is a second movable contact plate, and the vertical piece 10 and the horizontal piece are L.
The horizontal piece is provided with a movable contact 8 that comes into contact with and separates from the fixed contact 6. Vertical piece 10
is such that when both contacts 6 and 8 are closed, the proximal end thereof is parallel to the vertical piece 12 of the first movable contact plate 11 with a slight gap in between. It is rotatably supported on a shaft 13a. Further, the vertical piece 10 of the second movable contact plate 9 is connected to the vertical piece 12 of the first movable contact plate 11 by a spring 30 tensilely suspended between the intermediate part thereof and the intermediate part of the first movable contact plate 11.
It is spring-biased in the direction of approaching . moreover,
The base end of the vertical piece 10 and the tip of the vertical piece 12 of the first movable contact plate 11 are electrically connected by a braided wire 13.

With such a configuration, both movable contact plates 11, 9
Each horizontal piece faces substantially parallel to the short piece 5a of the fixed contact plate 4 to form a facing portion
, respectively. And this facing part X, Y
Currents in opposite directions flow through each member forming the .

Z is a link mechanism, which includes a first link piece 17 that suspends and connects the shaft 16 at the middle part of the reversing arm 15;
The second link piece 17 is connected to the first link piece 17 by the shaft 18.
The link piece 19 and the second link piece 19 are pivotally supported by a shaft 20 at an intermediate portion, and a pull-out plate 21 whose base end is pivotally supported by a shaft 27 and a lower end pin 22 are connected to the lower end pin 22. The first link piece 17 is configured by a tilting handle 23 that pushes the first link piece 17.

Reference numeral W denotes an overcurrent operating section, which is composed of a bimetal 24 and latch fittings 25 and 26, and this latch fitting 26 engages with the tripping plate 21. Reference numeral 32 denotes an electric path that electrically connects both contact plates 11, 9 and the load side terminal, and the bimetal 24 responds to heat according to the current of the electric path 32 by a heater or the like provided in the electric path 32.

Therefore, both contacts 6 and 8 open and close in response to the switching operation of the handle 23. Furthermore, when the bimetal 24 of the overcurrent operating part W operates, the latch fitting 26 and the tripping plate 21 disengage, and the tripping plate 21 rotates around the shaft 27, causing the link mechanism Z to become unbalanced and reversed. The arm 15 rotates about the shaft 28, thereby opening the contacts 6 and 8. Furthermore, when a large current such as a short-circuit current flows and both movable contact plates 11 and 9 are opened, the reversing arm 15 also rotates, causing the link mechanism Z to become unbalanced.

31 is an arc extinguishing device facing both contacts 6 and 8.

〔motion〕

Figures 1 and 2A show the contact state;
Current flows as shown by the arrow.

When a large current such as a short-circuit current flows in this state, electromagnetic repulsion is generated in both the facing portions X and Y. Therefore, as shown in FIG. It rotates in the opening direction from the first movable contact plate 11 against the urging force of 30.

Due to the rotation of both movable contact plates 11 and 9, the reversing arm 15 also rotates, causing the link mechanism Z to become unbalanced, and as shown in FIG. 2C, the reversing arm 15 rotates to the complete opening position. . At that time, the electromagnetic repulsion force disappears, and the second movable contact plate 9 is in contact with the first movable contact plate 11 due to the biasing force of the spring 30.

As is clear from this operation, when a large current flows through the electrical circuit, the second movable contact plate 9 provided with the movable contacts 8 receives electromagnetic repulsion from both the fixed contact plate 4 and the first movable contact plate 11. Therefore, the electromagnetic repulsion force becomes strong, and it rotates at high speed against the spring biasing force. In addition, the amount of displacement of the second movable contact plate 9 at the beginning of the opening operation is the sum of the amount of rotation of itself and the amount of rotation of the first movable contact plate 11, so it is more It will rotate at high speed. Furthermore, the distance between the movable contact plates 11 and 9 can be reduced since there is no need to consider withstand voltage.

〔effect〕

Since the electromagnetic repulsion contact device of the present invention is configured as described above, the second electromagnetic repulsion contact device provided with the movable contact is
The movable contact plate receives electromagnetic repulsion from both the fixed contact plate and the first movable contact plate, and the amount of displacement at the beginning of the opening operation is large. The electromagnetic repulsive force is large, and the opening/closing operation of the movable contact can be made faster.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a circuit breaker to which an embodiment of the present invention is applied, FIGS. 2A, 2B, and 3 are explanatory diagrams of its operation, and FIG. 3 is a perspective view of its essential parts. 4...Fixed contact plate, 5...U-shaped portion, 5a...
Short piece, 6... fixed contact, 9... second movable contact plate,
8... Movable contact, 10... Vertical piece, 11... First movable contact plate, 12... Vertical piece, 13... Braided wire, 15
...Reversing arm, 17... Link piece, 23... Handle, 29... Spring between reversing arm and first movable contact plate, 30... Spring suspended between both movable contact plates, X... Fixed contact plate and the facing portion between the two movable contact plates, Y...the facing portion between the two movable contact plates, and Z...the link mechanism.

Claims (1)

[Scope of Claims] 1. A fixed contact plate having a U-shape formed by a long piece and a short piece and having a fixed contact at the tip of the short piece, an inversion arm whose base end is rotatably supported, and a vertical A piece and a horizontal piece form an L-shape, and the base end of the horizontal piece is rotatably supported by the tip of the reversing arm so that it faces the short piece of the fixed contact plate, and the direction approaches the fixed contact plate. a first movable contact plate biased by a spring; a vertical piece and a horizontal piece forming an L-shape; a movable contact is provided on the horizontal piece; and a vertical piece of the first movable contact plate when the contact is closed The base end portion thereof is rotatably supported by the tip portion of the vertical piece of the first movable contact plate so as to face the first movable contact plate;
and a second movable contact which is biased by a spring in a direction approaching the vertical piece of the first movable contact plate, and in which the base end of the vertical piece and the tip of the vertical piece of the first movable contact plate are electrically connected. Both the fixed and movable contacts are opened and closed in response to the switching operation of the plate and the handle, and when the first and second movable contact plates are opened and separated, the link mechanism and the reversing arm are opened and closed to disrupt the symmetry of the link mechanism. and a link piece connecting the middle part of the circuit, and when a large current flows through the electric circuit, the second movable contact plate receives an electromagnetic repulsion force from the fixed contact plate and the first movable contact plate, and resists the spring biasing force. An electromagnetic repulsion contact device characterized in that it rotates.