JPH0574313A - Breaker for wiring - Google Patents

Abstract

PURPOSE:To prevent breakage of a torsion spring and deformation of a movable contact base and a support shaft by providing a groove for receiving the support shaft formed into a U-shape in the upper portion of a movable frame, and energizing the movable contact base downward by the torsion spring. CONSTITUTION:A movable contact base 2 is inserted into a movable frame 1, which is molded integrally, with a torsion spring 3 fitted to a support shaft 4, penetrated which the base 2. The support shaft 4 is pivoted under guidance of a U-shaped bearing groove 1a formed in the upper portion of the frame 1. Axial movement of the support shaft 4 is restricted, and the upper portion thereof is supported so as to be moved while utilizing the torsion spring 3 as a buffer material, thus providing a buffer effect with respect to force for lifting the base 2 upward in breaking so as to alleviate impact force applied to members. Therefore, it is possible to prevent breakage of the torsion spring due to repeated breaking and deformation of the movable contact base due to reaction force without generating contact misalignment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for wiring,
Particularly, the present invention relates to a structure suitable for improving reliability around the movable contact stand.

[0002]

2. Description of the Related Art The prior art is disclosed in Japanese Unexamined Patent Publication No. 2-51820, and, for example, as shown in FIGS.
Since the interlocking shaft that holds and supports the movable contact base 2 is a molded product, a support shaft 4 for holding the torsion spring 3 is required, and the support shaft 4 is inserted into the receiving groove 1a to move the movable contact. The table 2 is assembled into the movable frame 1 together with the torsion spring 3, and one end of the torsion spring 3 is locked to the upper part on the movable contact side, and the other end is locked to the movable frame 1, so that the contact pressure A is applied to the movable contact. , The reaction force B is generated on the support shaft 4,
The movable contact 5 prevents contact displacement due to the biasing force of the torsion spring 3.

In the prior art example shown in FIG. 7, a torsion spring 3 is fixed to a movable contact base 2 together with a support shaft 4, and the free end of the torsion spring 3 is elastically deformed and inserted into the movable frame 1 and moved. The support shaft 4 is supported by the side wall extending from the yoke 6 of the plunger 7 so as to prevent the support shaft 4 from coming off.

[0004]

In the above-mentioned prior art, in FIG. 5 and FIG. 6, the torsion spring 3 presses the movable contact base 2 from above to apply a contact pressure A to the movable contact 5, and from below. Since the U-shaped receiving groove 1a is formed, the support shaft 4
There is a possibility that the torsion spring 3 may be broken by the reaction force B generated in the above and the melted material at the time of breaking, and the contact shift and the deterioration of the insulating property are not sufficiently taken into consideration. Also in FIG. 7, since the movable contact point 2 is easily moved in the longitudinal direction and is supported by the side wall of the yoke 6 of the plunger 7, there is a problem in terms of assembly workability and insulation.

The present invention has been made in order to solve the above problems, and it is possible to prevent damage to a torsion spring due to repeated interruptions and damage to a movable contact base due to a reaction force without causing contact displacement, and to stabilize the contact. High reliability due to the
Another object of the present invention is to provide a circuit breaker for wiring, in which the movable contact block is protected from the melted material at the time of breaking, and which has excellent insulation performance.

[0006]

SUMMARY OF THE INVENTION The above object is to provide a movable contact base having a movable contact provided so as to face a fixed contact,
A movable frame that rotatably supports a support shaft of the movable contact base, and a wiring breaker that includes a torsion spring that is inserted into the support shaft to apply contact pressure in the direction toward the fixed contact to the movable contact base. In the container, the movable frame has a U-shaped receiving groove formed in a U-shape having a tip end portion that covers the vicinity of the contact point of the movable contact point and an open end in a direction opposite to the direction toward the fixed contact point. It is achieved by having.

[0007]

As described above, the U-shaped support shaft receiving groove is provided in the upper portion of the movable frame, and the torsion spring urges the movable contact base downward. The torsion spring acts to buffer the upward force of the movable contact base due to the reaction force, and prevents the movable contact base and the support shaft from being deformed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.
FIG. 9 shows an ON state of the wiring breaker of this embodiment. As shown in FIG. 9, the wiring breaker has a casing formed by a case 7 and a cover 8 provided thereon, and a circuit opening / closing mechanism is provided in the casing.

In the circuit opening / closing mechanism, a fixed contact base 9 is fixed to a case 7, and a movable contact base 2 having a contact 5 capable of contacting a contact 10 of the fixed contact base 9 is attached to a movable frame 1. The movable frame 1 is held in a casing composed of a case 7 and a cover 8, and the movable contact base 2
Is supported by a shaft 4, and a constant contact pressure is applied to the contact 5 of the movable contact base 2 to the contact 10 of the fixed contact 9 by the force of the spring 3.

In the movable frame 1, the lower part of the lower lever 20 and the upper part of the lower lever 20 are connected to the lower part of the upper lever 21 by the shaft 25, and the upper part of the upper lever 21 is connected to the hook 23 by the pin 31. Has been done.

The hook 23 is rotatably attached to the fixed frame 32 by a hook shaft 24 and is engaged with the trip fitting 17. The fixed frame 32 has a substantially U-shaped cross section and is fixed to the case 7.
Is supported by a shaft 26, and a relay shaft 27 is also supported.

The trip fitting 17 engages with the hook 23 and also with the relay shaft 27. The relay shaft 27 is integrally formed along the axial direction with a number corresponding to the number of each phase of the circuit breaker for wiring, and is rotatably attached to the fixed frame 32. When the bimetal 15 hits due to an overcurrent flowing during engagement with 17, the pressing force releases the engagement with the trip metal fitting 17.

On the other hand, a handle 18 protruding outward from an opening formed in the upper portion of the cover 8 and a handle lever 22 integrally attached to the handle 18 are rotatably held by a shaft 33. And the shaft 25
A drive spring 19 is stretched between them.

A heater 13 is connected to an end of the movable contact base 2 opposite to the contact 5 via a lead wire 12, and a terminal plate 16 is connected to the heater 13 via a coil-shaped conductor 14. It is connected. A bimetal 15 forming a part of a tripping mechanism is attached to the heater 13, and when an overcurrent flows in the circuit, the heat causes the bimetal 15 to bend to the left in FIG. 9 to rotate the relay shaft 27. I have to.

In addition to the bimetal 15, the trip mechanism has a movable core 29 which is attracted to the conductor 14 by the electromagnetic force of the conductor 14 when a large capacity overcurrent flows. The movable core 29 is supported by the yoke 6 and is attracted by the yoke 6 located below to rotate the relay shaft 15 so as to release the engagement between the relay shaft 15 and the trip fitting 17.

Further, an arc extinguishing device 11 for extinguishing a mark generated between the fixed contact 10 and the movable contact 5 is provided in the cover 8.

When the circuit breaker for wiring is manually operated, as shown in FIG. 9, when the movable contact 4 contacts the fixed contact 10 and the circuit is in the ON state, the handle 1
When 8 is rotated clockwise about the shaft 33, the handle lever 22 also rotates like the handle 18, and the spring force of the drive spring 19 causes the upper lever 21 to rotate counterclockwise about the shaft 11 accordingly.

As a result, the lower lever 20 is lifted upward, the movable frame 1 is rotated clockwise by the upward movement of the lower lever 20, and the movable contact base 2 is also rotated in the same direction, whereby the movable contact base 2 is moved. The contact 5 of is separated from the contact 10 of the fixed contact base 9 and is turned off.

When the handle 18 is rotated counterclockwise in the off state, the handle lever 22 also rotates in the same manner, and the spring force of the drive spring 19 causes the upper lever 21 to move the shaft 3 to the shaft 3.
While rotating clockwise about 1, the lower lever 20 is pushed downward, the movable frame 1 rotates counterclockwise by the downward movement of the lower lever 20, and the movable contact base 2 also rotates in the same direction. The contact 5 comes into contact with the contact 10 of the fixed contact base 9 to turn on the circuit.

Next, the tripping operation at the time of overcurrent will be described. When the overcurrent flows in the ON state, when the overcurrent is within the range of the long-time operation, the bimetal 15 is bent by the heat of the heater 13 and the relay shaft 27 is rotated counterclockwise. When the overcurrent is within the short-time operation range, the movable core 29 is attracted to the yoke 6 by the magnetic flux of the conductor 14 to rotate the relay shaft 27 counterclockwise.

By the counterclockwise rotation of the relay shaft 27, the engagement between the relay shaft 27 and the trip metal fitting 17 is released, and the trip metal fitting 17 is rotated clockwise about the shaft 26 by the pressing force of the relay shaft 27. As a result, the engagement between the trip fitting 17 and the hook 23 is released.

At that time, the hook 23 rotates counterclockwise about the shaft 24 by the spring force of the drive spring 19, the upper lever 21 and the lower lever 20 move upward, and the movable frame 1 rotates clockwise. , The movable contact base 2 separates from the fixed contact base 9 and enters a trip state to interrupt the circuit.

Next, the structure around the movable contact stand of this embodiment will be described. FIG. 1 is a plan view of a main part around a movable contact block of a circuit breaker for wiring according to this embodiment, FIG. 2 is a side view of the same, FIG.
FIG. 4 shows the respective assembling methods.

As shown in FIGS. 1 and 2, with the torsion spring 3 mounted on the support shaft 4 penetrating the movable contact base 2, the movable contact base 2 is placed in the movable frame 1 integrally molded. The support shaft 4 is inserted and supported by the U-shaped bearing groove 1a provided from the upper portion of the movable frame 1 as a guide.

Since the support shaft 4 is restricted in its movement in the longitudinal direction (axial direction) and is supported on the upper part so as to be movable by using the torsion spring 3 as a cushioning material, the movable contact base 2 at the time of interruption is lifted upward. It acts as a buffer against the force, and it is possible to reduce the impact force applied to each member.

The movable contact base 2 is movable around the support shaft 4, and the movable contact base 2 is covered up to the vicinity of the movable contact 5 by the tip 1c of the movable frame 1 to prevent contact displacement. In addition, it is possible to improve the insulation performance and protect the movable contact base 2 from the arc and the melted material at the time of interruption.

3 and 4 show an assembling method of this embodiment. In the rotation center hole of the movable contact base 2 equipped with the movable contact 5,
Together with the torsion spring 3, the shaft 4 of the support shaft 4 is passed through the movable contact base 2, and the U-shaped bearing groove 1a provided from above on the movable frame 1 serves as a guide for the support shaft 4 and one end 2b of the movable contact base 2 is used. It is inserted into the movable frame 1 more. As a result, the movable contact base 2 is stably attached to the lower portion of the U-shaped groove.

In this embodiment, the end portion 3b of the torsion spring 3 is hung on the one end portion 2b of the movable contact base 2 and the free end 3a is elastically deformed to be hung on the spring receiving portion 1b of the movable frame 1. Assembled to improve workability.

FIG. 8 shows another embodiment of the present invention. In this embodiment, the movable frame 1 is provided with a tip portion 1c so as to completely cover the movable contact 5. According to this embodiment,
It is possible to further improve the insulating property, protect the movable contact base 2, and increase the strength of the movable frame 1.

[0030]

According to the present invention, it is possible to prevent damage to the torsion spring due to repeated interruptions and damage to the movable contact base due to reaction force without causing contact displacement, and to ensure reliable operation for wiring. A circuit breaker is obtained.

Further, the movable contact block is protected from the melted material at the time of interruption, and a circuit breaker for wiring having excellent insulation performance can be obtained.

[Brief description of drawings]

FIG. 1 is a top view of essential parts of an embodiment of a circuit breaker for wiring according to the present invention.

FIG. 2 is a side sectional view of an essential part of the embodiment.

FIG. 3 is a view showing an assembling procedure of the above embodiment.

FIG. 4 is a view showing an assembling procedure of the above embodiment.

FIG. 5 is a top view of a main part of a conventional technique.

FIG. 6 is a side sectional view of a main part of a conventional technique.

FIG. 7 is a side sectional view of a main part of another conventional technique.

FIG. 8 is a side sectional view of a main part of another embodiment of the present invention.

FIG. 9 is an overall view showing an ON state of a wiring breaker according to an embodiment of the present invention.

[Explanation of symbols]

 1 movable frame 2 movable contact point 3 torsion spring 4 spindle 5 movable contact 6 yoke 7 plunger 8 cover 9 fixed contact point 10 fixed contact point 11 arc extinguishing device 12 lead wire 13 heater 14 conductor 15 bimetal 16 terminal plate 17 trip bracket 18 handle 19 Drive Spring 20 Lower Lever 21 Upper Lever 22 Handle Lever 23 Hook 24 Axis 25 Axis 26 Axis 27 Relay Axis 28 Axis 29 Movable Core 30 Spring 31 Pin 32 Fixed Frame 33 Axis

Claims (1)

[Claims] 1. A movable contact base having a movable contact provided to face a fixed contact, a movable frame rotatably supporting a support shaft of the movable contact base, and a movable frame inserted into the support shaft. In a circuit breaker provided with a torsion spring for applying a contact pressure in a direction toward the fixed contact to the contact base, the movable frame includes a tip end portion covering the vicinity of the contact of the movable contact base and a direction toward the fixed contact. A circuit breaker for wiring, comprising a U-shaped receiving groove of the support shaft having an open end in the opposite direction.