JPS5823162Y2 - circuit breaker - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a circuit breaker.

The purpose of this invention is to be able to immediately make 6 calls to interrupt the circuit and prevent damage to the load in response to instantaneous short-circuit currents that bimetals cannot respond to, and to be able to be made small and lightweight. To provide a circuit breaker.

In conventional circuit breakers that only use bimetal,
Although it can prevent a slight overcurrent that exceeds the rated current from flowing for a long time, it cannot operate against instantaneous short-circuit current that far exceeds the rated current, and the drawback is that it can instantly damage the load. Some devices use electromagnets for this purpose, but the electromagnets themselves take up a lot of space, making it difficult to make them smaller and lighter.

The present invention has been devised in view of the above points, and will be explained in detail below using Examples.

The housing 10 of the circuit breaker is composed of a base 11 and a cover 12, both of which are molded from synthetic resin.The base of a handle 15 is pivotally supported via a shaft 14 to an arm 13 that projects above the base 11. 15 is a U-shaped rod 16
It is connected to the drive plate 17 at.

This U-shaped rod 16 has one leg 16a attached to the handle 15.
The other leg 16b is pivotally supported on a drive plate 17, and when the handle 15 is rotated counterclockwise in the figure, the drive plate 17 is lowered and the presser foot located on the movable contact plate 18 is moved. The movable contact plate 18 is pushed down via the member 19 to bring the movable contact 3 into contact with the fixed contact 2.

Here, the movable contact plate 18 is urged upward by a compression coil spring 20, and the connection between the movable contact 3 and the fixed contact 2 is made when the drive plate 17 is lowered against the spring force of the compression coil spring 20. The upper leg 16a of the U-shaped rod 16 is locked and held in the recess 21 of the arm 13.

The actuator 1 is erected near the rear end of the drive plate 17 with its lower end pivotally supported on the base 11, and the drive plate 17 is always biased and rotated by a spring (not shown) to prevent it from locking. The rear end 17b of the drive plate 17 is placed and locked on the protrusion 23, and when the actuator 1 is displaced clockwise in the figure, the rear end 17b of the drive plate 17 is placed and locked on the protrusion 23.
7b comes off from above the locking protrusion 23, and accordingly, the spring force of the compression coil spring 20 causes the drive plate 17 to be removed.
The front end springs upward, and at the same time, the U-shaped rod 16 also moves upward, and the upper leg piece 16a pops out from within the recess 21 beyond the line of descent of the shaft 14 of the handle 15, and the handle 15 is moved upward to the shaft 14. The movable contact 3 and the fixed contact 2 are opened by flipping them clockwise with the help of a torsion coil spring (not shown) that is inserted into the spring and biased clockwise. The mechanism is configured.

The lower end of the bimetal 5 is attached to the movable contact plate 18 with the mounting screw 25.
is electrically connected to the base of the actuator 11 and fixed to the base 11, with its free upper end facing closely to the actuator 1, and electrically connected to the terminal 26 with a stranded wire 27, which exceeds the rated current. When an overcurrent flows for a long time, the actuator 1 bends and presses the screw 30 screwed into the actuator 1, displacing the actuator 1 clockwise in the figure, and the link mechanism connects the movable contact 3. The fixed contact 2 is opened.

The movable piece 6 is formed of a thin magnetic metal piece, and its lower end is connected to the bimetal 5 and the movable contact plate 18 by the mounting screw 25.
Connect electrically to the base 11 and attach it to the bimetal 5.
The bimetal 5 is arranged close to the bimetal 5 in parallel with the movable piece 6 to form a magnetic circuit.
The movable piece 6 is drawn toward the bimetal 5 by the electromagnetic attraction force acting between the movable piece 6 and the bimetal 5.

Here, an adjustment screw 7 is screwed onto the bottom surface of the movable piece 6.
This adjustment screw 7 protrudes toward the actuator 1 through the through hole 33 of the bimetal 5, and when the movable piece 6 moves under suction, the adjustment screw 7 presses against the actuator 1 and displaces the actuator 1 as described above. The movable contact 3 and the fixed contact 2 are opened by a link mechanism.

Further, a coil spring 34 is inserted into the adjustment screw 7 between the bimetal 5 and the movable piece 6, and biases the movable piece 6 in the direction of separating it from the bimetal 5. By rotating the adjustment screw 7, The distance between the actuator 1 and the adjustment screw 7 can be made variable to change the instantaneous operating range of the link mechanism that disconnects the actuator 1, that is, the movable contact 3 and the fixed contact 2.

As mentioned above, the present invention includes a link mechanism that releases the connection between a fixed contact and a movable contact by displacement of the actuator, and a link mechanism in which one end is fixed and deforms when an overcurrent occurs, and the free end comes into contact with the actuator and is displaced. A movable piece that has magnetism and is attracted to the bimetal when an overcurrent flows through the bimetal, and a movable piece that is placed next to the bimetal to form a magnetic circuit. The mechanism consists of an adjustment screw screwed onto a movable piece in order to displace the actuator through a through hole drilled in the bimetal when it is attracted, and the bimetal is free to deform when an overcurrent occurs. The adjustment screw screwed into the end and the movable piece is brought into contact with the actuator of the link mechanism, and the link mechanism is activated when an overcurrent or short circuit current occurs.
The engagement mechanism between the bimetal and movable piece and the actuator of the link mechanism can be configured extremely easily without the use of special engagement parts, and immediately interrupts the circuit in response to a short-circuit current and prevents damage to the load. This has the effect that a circuit breaker that can prevent this can be made small and lightweight, and the cost can be reduced.

[Brief explanation of drawings]

FIG. 1 is a front sectional view showing the internal mechanism of an embodiment of the present invention;
Figure 2 is an enlarged view of the main parts of the same as above, Figure 3 is X-X in Figure 2.
1 is a line cross-sectional view, 1 is an actuator, 2 is a fixed contact, 3 is a movable contact, 5 is a bimetal, 6 is a movable piece, and 7 is an adjustment screw.

Claims (1)

[Scope of utility model registration request] A link mechanism that releases the connection between a fixed contact and a movable contact by displacement of the actuator, a bimetal whose one end is fixed and deforms when an overcurrent occurs, and whose free end abuts the actuator and displaces it, and a bimetal placed close to the bimetal. A movable piece that has magnetism and is attracted to the bimetal when an overcurrent flows through the bimetal, and a movable piece that is drilled in the bimetal when the movable piece is attracted to the bimetal. A circuit breaker comprising an adjustment screw screwed into a movable piece to displace the actuator by abutting it through a through hole.