JPH0554786A - Movable contact device of circuit breaker - Google Patents

Abstract

PURPOSE:To miniaturize a movable contact device in a circuit breaker having a middle capacity or more. CONSTITUTION:Two flat conductors 1A, 1B having longitudinal sections are arranged in parallel to each other to form a movable contact conductor 1 for one phase, a connecting conductor 12 fixed to a case is nipped by the flat conductors 1A, 1B and pressed by a spring 13 to bring the movable contact conductor 1 into sliding contact with the connecting conductor 12. Thus, since the width dimension of the movable contact conductor 1 is contracted, compared with a conventional structure using a plate conductor having a transverse section, and a lead for connecting the movable contact conductor 1 to the connecting conductor 12 is not required, the longitudinal space can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable contactor device used for a circuit breaker for a wiring or an earth leakage circuit breaker, and more particularly to a movable contactor device suitable for a circuit breaker having a medium capacity or more.

[0002]

2. Description of the Related Art In general, a movable contact in a circuit breaker is rotatably supported by a case via an opening / closing shaft made of an insulating material, and a movable contact is attached to one end of the case.
The other end is movably connected to a connection conductor fixed to the case. The movable contact conductor is usually composed of a flat plate conductor, but in that case, in a small-capacity circuit breaker, the flat plate conductor is used in such a direction that the cross section becomes vertically long, that is, the plate thickness becomes the width direction.

It is rational that the movable contactor conductor having a vertically long cross section has high mechanical strength in the opening / closing direction and requires less space in the width direction of the circuit breaker, but on the other hand, the joint surface of the movable contact is a flat plate conductor. However, there is a problem in that only the thickness of the sheet can be obtained and the current-carrying capacity is restricted. Therefore, in a circuit breaker of a medium size or larger, for example, a 225 A frame or larger, the movable contactor conductor has a laterally long cross section, and the movable contact is joined to the flat surface of the flat conductor.

FIG. 7 and FIG. 8 show such a conventional movable contact device, FIG. 7 is a perspective view showing three phases collectively, and FIG. 8 is an enlarged vertical sectional view of one of them. is there. In the figure, the movable contactor conductor 1 press-formed from a copper strip is
It is fixed by caulking at two front and rear positions to a support plate 2 made of a steel plate whose side walls are bent, and the support plate 2 is rotatably supported by a pin 4 on a bifurcated holder 3 made of a steel plate. The holder 3 is fitted into an opening / closing shaft 5 of an insulating material that extends over each phase, and both legs are fixed by U-shaped metal fittings 6 crimped thereto.

A movable contact 7 is joined to the front portion of the lower surface of the movable contact conductor 1, and a lead wire 8 made of a braided copper wire is attached to the rear end portion.
Are joined at one end. The other end of the lead wire 8 is joined to a connection conductor (not shown) fixed to the case of the circuit breaker, and this connection conductor is further connected to a conductor of an overcurrent trip device (not shown). A contact spring 9 composed of a tension spring is stretched between the support fitting 2 and the holder 3.

[0006]

However, such a conventional structure has the following problems. (1) As described above, since the flat plate conductor that constitutes the movable contactor conductor 1 is used in a laterally long cross section, it requires a large space in the width direction, and it is difficult to miniaturize the circuit breaker. (2) Compensating for the mechanical strength in the thickness direction of the movable contactor conductor 1,
Further, since the support fitting 2 is required to pass the pin 4, the structure becomes complicated. (3) The movable contactor conductor 1 is connected to a connection conductor (not shown) via the lead wire 8, but the lead wire 8 has a certain degree of rigidity, and this rigidity changes depending on the bending state of the lead wire 8. Therefore, the contact pressure and the opening / closing speed between the movable contact 7 and the fixed contact (not shown) are likely to vary. (4) There is a risk that the lead wire 8 may be fatigued and broken due to repeated bending accompanying the opening and closing movements of the movable contact, and if a length is allowed to prevent it, the lead wire 8 The required space becomes large. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems, to provide a movable contactor device for a circuit breaker that requires a small space, has a simple structure, and does not require the use of lead wires.

[0007]

According to the present invention, two flat plate conductors having a vertically long cross section are arranged in parallel on the left and right to form a movable contact conductor for one phase, and a movable contact is provided at one end of the movable contactor conductor. The above-described object is achieved by slidably sandwiching the connection conductor fixed at the end to the case of the circuit breaker by the plate conductor, and further pressing the plate conductor against the connection conductor with a spring. In the above device, if the flat plate conductors are connected to each other in the vicinity of the movable contact, parts management and assembly work will be facilitated. Also, in the above device, by inserting a compression spring between flat conductors near the connection conductor or by providing a protrusion on one inner surface of the flat conductor, an excessive electromagnetic attraction force between the flat conductors when a large current flows Can be relaxed.

[0008]

Function: Two flat plate conductors are arranged in parallel in the longitudinal direction to form a movable contact conductor for one phase. As a result, it is possible to reduce the size in the width direction as in the case of the small capacity circuit breaker, obtain a large mechanical strength in the opening / closing direction, and obtain a wide joint surface for the movable contact. Also, at that time,
A lead wire becomes unnecessary by sandwiching the connection conductor between two flat plate conductors and pressing them from both sides with springs to electrically connect the two by sliding contact.

If the flat plate conductors are connected to each other in the vicinity of the movable contact, the two flat plate conductors can be integrated without obstructing the contact with the connecting conductor, which facilitates the handling. Currents flow in the same direction in the two flat plate conductors arranged in parallel. Therefore, an electromagnetic attraction force is generated between these currents, and the flat plate conductor is pressed against the connection conductor to obtain a good contact state.

However, when the electromagnetic attraction force becomes too large and galling may occur on the sliding contact surface when the short-circuit current is cut off, a compression spring is inserted between the flat plate conductors in the vicinity of the connection conductor, so that The force can alleviate the electromagnetic attraction force and prevent an unnecessary contact pressure from being generated between the flat conductor and the connecting conductor. Similarly, by providing a protrusion on one inner surface of the flat plate conductor near the connection conductor, when the flat plate conductor is bent and deformed inward by the electromagnetic attraction force, this projection is abutted on the other flat plate conductor to reduce the bending amount. It is possible to suppress the occurrence of excessive contact pressure.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. The same reference numerals are used for the parts corresponding to the conventional example. Embodiment 1 First, FIGS. 1 and 2 show a basic embodiment of the present invention. FIG. 1 is a plan view showing three phases collectively, and FIG.
It is sectional drawing which follows the II-II line. In the figure, the movable contactor conductor 1 for each phase is composed of two left and right flat plate conductors 1A and 1B having a vertically long cross section. Movable contacts 7A and 7B are separately joined to the lower surfaces of one ends of the flat plate conductors 1A and 1B by brazing. Reference numeral 10 is a fixed contact that contacts the movable contacts 7A and 7B in common, and 11 is a fixed contactor conductor to which the fixed contact 10 is joined.

Reference numeral 12 is a connecting conductor made of a plate material, and is composed of an L-shaped support member 12a and an L-shaped connecting piece 12b joined to the front surface thereof. The movable contact conductor 1 has a connecting piece 12b sandwiched between the other ends of the flat plate conductors 1A and 1B and is electrically connected thereto. 4 is a flat conductor 1
It is supported by the holder 3 by a pin penetrating A, 1B and the connecting piece 12b, and the movable contactor conductor 1 rotates about the pin 4 as a fulcrum and slides on the connecting piece 12b. Numeral 13 is a compression spring inserted between the movable contactor conductor 1 and the holder 3 on both sides of the movable contactor conductor 1, and is attached to the pin 4 to press the flat plate conductors 1A and 1B against the connecting piece 12b, and the contact pressure required between them. Generate.

The holder 3 is made of molding resin,
It is formed integrally with the opening / closing shaft 5 that connects the holders 3 of the respective phases to each other. The opening / closing shaft 5 is supported by bearing grooves provided in a phase gap wall of a case (not shown), and the holder 3 rotates about the opening / closing shaft 5. Reference numeral 9 is a contact spring composed of a compression spring, and in this case, a spring bearing 14 fixed to the case of the circuit breaker.
Is inserted between the movable contact conductor 1 and the end of the movable contact conductor 1,
The movable contact conductor 1 is biased in the counterclockwise direction of FIG. 2 around the pin 4 to press the movable contacts 7A and 7B against the fixed contact 10,
The required contact pressure is created between them.

In the above structure, the current flows from the fixed contact conductor 11 to the movable contact conductor 1 via the fixed contact 10 and the movable contacts 7A and 7B, and further to the connection conductor 12 which is in sliding contact therewith. As shown by the arrows in FIG. 1, since currents flow in the parallel plate conductors 1A and 1B in the same direction, an electromagnetic attractive force acts between these currents, and the flat plate conductors 1A and 1B have an electromagnetic attractive force. Is pressed against the connecting piece 12b, and the contact pressure is increased. During the opening operation of the circuit breaker, the holder 3 connected to the toggle link of the opening / closing mechanism (not shown) is driven in the clockwise direction in FIG. 2, and the movable contact conductor 1 is pulled up accordingly. At that time, the flat plate conductors 1A and 1B slide against the connection piece 12b while being pressed against each other by the compression spring 13.

According to the illustrated embodiment, the flat plate conductors 1A, 1B
By configuring the movable contactor conductor 1 as a vertically long section, the space in the width direction can be small, the mechanical strength in the opening / closing direction is high, and the pin 4 can be directly inserted into the flat plate conductors 1A and 1B. The supporting metal fitting 2 (FIG. 8) as in the prior art is unnecessary. Also, the flat plate conductors 1A and 1B
By arranging two of them in parallel, it is possible to obtain a sufficient joining space for the movable contacts 7A and 7B and the current-carrying area of the movable contactor conductor 1 even in a circuit breaker having a medium capacity or more, and also good heat dissipation. Becomes The movable contacts 7A and 7B may be integrally provided so as to straddle the flat plate conductors 1A and 1B.
As shown in the drawing, the contact state with the fixed contact 10 is improved when the flat conductors 1A and 1B are separately provided. Further, since the connecting conductor 12 is sandwiched between the two flat plate conductors 1A and 1B and electrically connected by sliding contact, the conventional lead wire 8 (FIG. 8) becomes unnecessary, and variations in contact pressure and disconnection occur. The danger of is eliminated.

Embodiment 2 FIG. 3 is a plan view of Embodiment 2 of the present invention, and FIG. 4 is a side view thereof. In this embodiment, the connecting piece 1 is provided between the flat plate conductors 1A and 1B at the end on the side where the movable contacts 7A and 7B are provided.
6 is brazed, and the plate conductors 1A and 1B are connected to each other. According to such a configuration, the two flat plate conductors 1
As A and 1B are integrated, handling in parts management and assembly work becomes easy. Other configurations are the same as those in the first embodiment.

Embodiment 3 FIG. 5 is a plan view showing Embodiment 3 of the present invention. In this embodiment, the flat plate conductors 1A and 1B are provided near the connection conductor 12.
The compression spring 16 is inserted between them. This compression spring 16
Is attached to a pin 17 inserted across the flat plate conductors 1A and 1B, and retaining rings 18 are fitted to both ends of the pin 17. With such a configuration, the electromagnetic attraction force acting between the flat plate conductors 1A and 1B is mitigated by the compression spring 16, and galling of the sliding contact surface due to an excessive electromagnetic attraction force is prevented.

Embodiment 4 FIG. 6 is a plan view showing Embodiment 4 of the present invention. In this embodiment, one flat plate conductor 1A is provided near the connection conductor 12.
Is provided with a protrusion 19 toward the other plate conductor 1B. The protrusion 19 is formed by extrusion molding by pressing from the outer surface of the flat plate conductor 1A. According to such a configuration, when the flat plate conductors 1A and 1B are curved and deformed inward by the electromagnetic attraction force, the deformation amount is regulated by the protrusion 19,
Also in this case, the excessive electromagnetic attraction force is alleviated, and galling of the sliding contact surface is prevented.

[0019]

According to the present invention, the movable contact conductor is constituted by arranging two flat plate conductors each having a vertically long cross section in parallel on the left and right sides,
The connecting conductor is slidably sandwiched between flat conductors and pressed into contact with a spring, which reduces the space in the width direction and downsizes the circuit breaker, and supports the movable contact conductor and the holder. Is unnecessary, the structure is simplified, and the lead wire between the movable contactor conductor and the connection conductor is not required, so that the opening / closing operation is stable and there is no fear of disconnection. In that case,
By coupling the flat conductors to each other in the vicinity of the movable contact, it becomes easier to handle the movable contactor conductors during assembly work.In addition, insert a compression spring between the flat conductors near the connecting conductor, or By providing the protrusion on the inner surface, it is possible to prevent galling of the sliding contact surface due to an excessive electromagnetic attraction force between the flat plate conductors.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a plan view of a second embodiment of the present invention.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a plan view of a third embodiment of the present invention.

FIG. 6 is a plan view of Embodiment 4 of the present invention.

FIG. 7 is a perspective view of a conventional example.

FIG. 8 is an enlarged vertical sectional view of FIG.

[Explanation of symbols]

 1 Movable Contact Conductor 1A Flat Plate Conductor 1B Flat Plate Conductor 7A Movable Contact 7B Movable Contact 12 Connection Conductor 16 Compression Spring 19 Protrusion

Claims (4)

[Claims] 1. A movable contact conductor for one phase is formed by arranging two flat plate conductors each having a vertically long cross section in parallel to the left and right, and a movable contact is provided at one end of the movable contact conductor, and the other end is used as a case of a circuit breaker. A movable contactor device for a circuit breaker, wherein a fixed connecting conductor is slidably sandwiched between the plate conductors, and the plate conductor is pressed against the connecting conductors by a spring. 2. A movable contactor device for a circuit breaker according to claim 1, wherein flat plate conductors are connected to each other in the vicinity of the movable contact. 3. The movable contactor device for a circuit breaker according to claim 1, wherein a compression spring is inserted between the flat plate conductors near the connection conductor. 4. The movable contactor device for a circuit breaker according to claim 1, wherein a protrusion is provided on one inner side surface of the flat plate conductor in the vicinity of the connection conductor.