JP3018591B2 - Circuit breaker for wiring - Google Patents

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 a movable contact stand.

[0002]

2. Description of the Related Art The prior art is disclosed in Japanese Patent Laid-Open Publication No. Hei 2-51820. 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. The support shaft 4 is inserted into the receiving groove 1a to move the movable contact. The base 2 is assembled into the movable frame 1 together with the torsion spring 3, and one end of the torsion spring 3 is locked on the upper portion on the movable contact side, and the other end is locked on the movable frame 1. And a reaction force B is generated on the support shaft 4,
The movable contact 5 prevents a contact shift due to the urging 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 stand 2 together with a support shaft 4, and the torsion spring 3 is inserted into the movable frame 1 while elastically deforming its free end. The support shaft 4 is supported by the side wall extending from the yoke 6 of the plunger 7 to prevent the support shaft 4 from coming off.

[0004]

In the prior art described above, in FIGS. 5 and 6, the movable contact base 2 is pressed from above by a torsion spring 3 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 the interruption, and sufficient consideration has not been given to the contact shift and the deterioration of the insulation. 7 also has a problem in terms of assembling workability and insulation because the movable contact stand 2 is easily moved in the longitudinal direction and is supported by the side wall of the yoke 6 of the plunger 7.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and can prevent breakage of a torsion spring due to repetition of interruption and breakage of a movable contact stand due to a reaction force without causing a contact shift. High reliability
Another object of the present invention is to provide a circuit breaker for wiring in which the movable contact block is protected from a melted substance at the time of interruption and has excellent insulation performance.

[0006]

An object of the present invention is to provide a movable contact.
And the bottom of the above movable contact block so as to face the fixed contact.
The fixed movable contact and the movable contact can freely contact and separate from the fixed contact
A spindle inserted through the center of rotation of the movable contact block so that
And a movable frame that rotatably supports the support shaft, and a support shaft
Contact pressure in the direction of the fixed contact on the movable contact block when mounted
In a circuit breaker for wiring provided with a torsion spring for applying force,
The movable contact block has a shape that is bent in a substantially “H” shape.
Movable contact at the position facing the fixed contact at one side end of the "H"
The point is fixed and the support shaft is near the bent part of the
It is inserted and connected to the other side of the "H" by torsion spring
Has a spring hook that receives force in the direction in which point pressure is applied.
And the movable frame is at least near the movable contact
If you have a bottom part that covers the bottom of the movable contact block between
Originally formed to extend along both sides of the movable contact block
It has a side part, and it is compatible with the movable contact block on the side part of the movable frame.
When the facing surface has a support groove for the support shaft at a position facing the support shaft
Both of the torsion springs are located between the support shaft and the movable contact.
It has a spring receiving part to lock the free end, and the receiving groove is movable frame
U-shaped with an open end in the direction opposite to the bottom
And the torsion spring is a coiled part
Extending almost tangentially from one end of the coiled part
Pressure applied to the movable contact by the spring hook of the movable contact
From the other end of the coiled part
The free end that extends and is locked to the spring
The movable contact has a torsion spring contact pressure at the spring hook.
The application part is locked and the support shaft is formed as a coil of a torsion spring.
The shaft is supported in the receiving groove through the inside of the wound part
The free end of the torsion spring engages the spring receiver of the movable frame
When stopped, it is rotatably supported on the movable frame.
And the torsion spring moves in the direction in which the movable contact
This is achieved by being configured to buffer the force of

[0007]

As described above, the movable contact of the side surface of the movable frame
The surface facing the point base points toward the bottom of the movable frame
It has a U-shaped support shaft receiving groove having an open end in the opposite direction (upper direction) to the (lower) direction .
Prevents upward or downward movement from being restrained
You. The movable contact applies a torsion spring contact pressure to the spring hook.
Part is locked and the support shaft is wound in a coil shape of a torsion spring.
A state in which it passes through the inside of the turned part and is pivotally supported in the receiving groove
To lock the free end of the torsion spring to the spring receiving part of the movable frame
The support shaft is elastically held in the receiving groove by the torsion spring.
Be held. At this time , since the torsion spring urges the movable contact base downward, the torsion spring operates so as to buffer the upward force of the movable contact base due to the reaction force of the circuit breaker. Prevent shaft deformation.

[0008]

An embodiment of the present invention will be described with reference to the drawings.
FIG. 9 shows the ON state of the circuit breaker of this embodiment. As shown in FIG. 9, the wiring circuit breaker has a casing composed of 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 stand 9 is fixed to a case 7, and a movable contact stand 2 having a contact 5 that can contact a contact 10 of the fixed contact stand 9 is attached to the movable frame 1. The movable frame 1 is held in a casing composed of a case 7 and a cover 8,
Are supported by a shaft 4, and a constant contact pressure is applied to the contact 5 of the movable contact stand 2 against the contact 10 of the fixed contact 9 by the force of the spring 3.

The lower portion of the lower lever 20 is connected to the movable frame 1, the upper portion of the lower lever 20 is connected to the lower portion of the upper lever 21 by a shaft 25, and the upper portion of the upper lever 21 is connected to a hook 23 by a pin 31. Have been.

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

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

On the other hand, a handle 18 protruding to the outside from an opening formed in an 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 axis 25
A drive spring 19 is stretched between them.

A heater 13 is connected to an end of the movable contact stand 2 opposite to the contact 5 via a lead wire 12, and a terminal plate 16 is connected to the heater 13 via a conductor 14 formed in a coil shape. It is connected. A bimetal 15 constituting a part of a tripping mechanism is attached to the heater 13, and when an overcurrent flows through the circuit, the bimetal 15 is bent to the left in FIG. 9 by the heat to rotate the relay shaft 27. I have to.

The tripping mechanism has, in addition to the bimetal 15, a movable core 29 which is attracted to the conductor 14 by the electromagnetic force of the conductor 14 when a large amount of overcurrent flows. The movable core 29 is supported by the yoke 6, and is attracted to the yoke 6 below, thereby rotating the relay shaft 15 so as to release the engagement between the relay shaft 15 and the trip metal 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 wiring breaker is manually operated, as shown in FIG. 9, when the movable contact 4 contacts the fixed contact 10 and the circuit is turned on, the handle 1 is turned on.
When the handle 8 is rotated clockwise about the shaft 33, the handle lever 22 also rotates similarly to the handle 18, and the upper lever 21 rotates counterclockwise about the shaft 11 by the spring force of the drive spring 19.

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, thereby moving the movable contact base 2 Are separated from the contacts 10 of the fixed contact stand 9 and are turned off.

When the handle 18 is turned counterclockwise in the off state, the handle lever 22 also rotates in the same manner, and the upper lever 21
1 and the lower lever 20 is pushed down, the movable frame 1 is rotated counterclockwise by the downward movement of the lower lever 20, and the movable contact base 2 is also rotated in the same direction. The contact 5 comes into contact with the contact 10 of the fixed contact stand 9 and the circuit is turned on.

Next, a trip operation at the time of overcurrent will be described. If an overcurrent flows in the ON state, and the overcurrent is within the range of the long-time operation, the bimetal 15 bends due to the heat of the heater 13 and rotates the relay shaft 27 counterclockwise. When the overcurrent is within the short time limit operation, the movable core 29 is attracted to the yoke 6 by the magnetic flux of the conductor 14, thereby rotating the relay shaft 27 counterclockwise.

When the relay shaft 27 rotates counterclockwise, the engagement between the relay shaft 27 and the trip fitting 17 is released, and the trip fitting 17 rotates clockwise about the shaft 26 by the pressing force of the relay shaft 27. Accordingly, the engagement between the trip fitting 17 and the hook 23 is also released.

At this time, the hook 23 rotates counterclockwise around the shaft 24 by the spring force of the driving spring 19, and the upper lever 21 and the lower lever 20 move upward, so that the movable frame 1 rotates clockwise. Then, the movable contact stand 2 separates from the fixed contact stand 9 and trips to cut off 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 stand of the circuit breaker according to the present embodiment, FIG.
FIG. 4 shows the assembling method.

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

The support shaft 4 is restricted from moving in the longitudinal direction (axial direction), and is supported on the upper portion so as to be movable using the torsion spring 3 as a cushioning material. It acts as a buffer against the force, and can reduce the impact force applied to each member.

The movable contact base 2 is movable about the support shaft 4. The movable contact base 2 is covered with the distal end portion 1c of the movable frame 1 to the vicinity of the movable contact 5 to prevent contact displacement. In addition, the insulation performance can be improved, and the movable contact stand 2 can be protected from arcs and melted substances at the time of interruption.

FIGS. 3 and 4 show an assembling method according to this embodiment. In the rotation center hole of the movable contact stand 2 having the movable contact 5,
One end 2b of the movable contact base 2 is guided by the U-shaped bearing groove 1a provided on the movable frame 1 from the upper part of the movable contact base 2 with the torsion spring 3 so as to guide the support shaft 4. It is inserted into the movable frame 1. Thereby, the movable contact stand 2 is mounted in a stable state below the U-shaped groove.

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

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 the present embodiment,
It is possible to further improve the insulating property, protect the movable contact stand 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 repetition of interruption and damage to the movable contact stand due to reaction force without causing contact shift, and to achieve highly reliable wiring for stable operation. A circuit breaker is obtained.

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

[Brief description of the drawings]

FIG. 1 is a main part top view of an embodiment of a circuit breaker of the present invention.

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

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

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

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

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

FIG. 7 is a sectional side 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 circuit breaker according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Movable frame 2 Movable contact block 3 Torsion spring 4 Support shaft 5 Movable contact 6 Yoke 7 Plunger 8 Cover 9 Fixed contact block 10 Fixed contact 11 Arc extinguishing device 12 Lead wire 13 Heater 14 Conductor 15 Bimetal 16 Terminal plate 17 Trip fitting 18 Handle Reference Signs List 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

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01H 73/02

Claims (1)

(57) [Claims] 1. A movable contact base and an upper surface facing a fixed contact.
A movable contact fixed to the bottom surface of the movable contact base;
The movable contact so that the contact can freely contact and separate from the fixed contact
The support shaft inserted through the center of rotation of the dot stand and the support shaft
The movable frame that is supported at the moment and the
The contact pressure in the direction toward the above fixed contact is applied to the movable contact
In a circuit breaker for wiring provided with a torsion spring to be applied,
The movable contact block has a shape that is bent in a substantially “H” shape.
At a position facing one end of the "heavy" character and facing the fixed contact,
Near the bent part of the "H" shape with the movable contact fixed
The above spindle is inserted into the
Receives force in the direction in which contact pressure is applied by a torsion spring
A spring hook portion, wherein the movable frame is at least
The movable contact base between the support shaft and the vicinity of the movable contact
A movable contact having a bottom surface portion for covering the bottom surface of the movable contact;
It has side portions formed to extend along both sides of the table.
Then, on the movable contact stand on the side surface of the movable frame,
The facing surface is located at the position facing the support shaft, and the receiving groove of the support shaft
And between the support shaft and the movable contact.
A spring receiving portion for locking the free end of the torsion spring
And the receiving groove is directed toward the bottom of the movable frame.
Formed in a U-shape having an open end in the opposite direction to
The spring is wound around the coil and the coil
The movable contact extends from one end of the
A contact pressure applying portion locked to the spring hook portion of the child;
Extends almost tangentially from the other end of the coiled part
Free to be locked by the spring receiving portion of the movable frame
The movable contact is twisted to the spring hook.
The contact pressure applying portion of the spring is locked and
The shaft is one of the above-mentioned coiled portions of the torsion spring.
The above-mentioned torsion
The free end of the collar locks to the spring receiving part of the movable frame
Is supported by the movable frame
The torsion spring is configured such that the movable contact base is an open end of the receiving groove.
A circuit breaker for wiring, wherein the circuit breaker is configured to buffer a force in a direction toward .