JPH0528900A - Circuit breaker - Google Patents

Abstract

PURPOSE:To form a small-sized circuit breaker free from influence of the ambient temp. by permitting the magnetic field of each coil to strengthen when over-current flows in the applicable circuit, and allowing a pair of opposed magnetic material pieces to attract each other or repulse each other. CONSTITUTION:A coil 3 is wound on a moving magnetic material piece 1 while a coil 4 is wound on a stationary magnetic material piece 2 in the direction opposite the coil 3. Therefore, when current is flowing in the coils, one of the magnetic material pieces is magnetized in N-pole while the other magnetized in S-pole. Magnetic field generated in the coils 3, 4 remains small as long as the current flowing in the circuit is normal, not exerting a magnetic force such as to move the moving magnetic material piece. A movable piece 5 through a movable piece connecting rod 6 touches a circuit closing contact 7, and the circuit is closed. When over-current flows in the circuit, on the other hand, the magnetic field of the coils 3, 4 strengthens, and the magnetic material pieces attract each other, and the moving magnetic material piece moves downward. Accordingly the movable piece moves to a circuit opening contact 8 through the connecting rod 6, and the circuit broken, Then the movable piece is returned by hand to the circuit closing contact, and the circuit is closed.

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 breaking a circuit when an overcurrent flows through the circuit.

[0002]

2. Description of the Related Art Conventionally, a general circuit breaker uses a bimetal, and when an overcurrent flows through the bimetal, the bimetal is heated and curvedly displaced in response to the overcurrent, and a spring caught on the bimetal portion. There is a mechanical type in which the operating plate comes off and the lever falls to shut off the circuit.

On the other hand, as shown in FIG. 2, there is an oil damper type circuit breaker. Cylinder 11 is plug 1
It is sealed by 2, and a plunger 13 is inserted in the cylinder, and the plunger is pressed in the direction opposite to the plug by a spring 14 placed on the plug side. The cylinder is filled with silicone oil. A solenoid coil 15 is wound around the outside of the cylinder.

When a current flows through the solenoid coil, it forms a magnetic field. When the current flowing through the solenoid coil is normal, the magnetic field does not have enough force to move the plunger. When an overcurrent flows through the solenoid coil, the magnetic force becomes stronger, and the plunger is attracted toward the plug against the force of the spring. When the magnetic force reaches a certain strength, the plunger reaches the plug, and the plug attracts the armature 16 by the magnetic force to cut off the circuit.

The silicone oil in the cylinder plays a role in adjusting the moving speed of the plunger to be slow. Then, when the circuit is interrupted, the magnetic field disappears because no current flows through the coil, and the plunger returns to its original position by the spring.

This oil damper type circuit breaker is
The solenoid coil is wound on the outside of the cylinder, and the number of turns of the coil is extremely large, resulting in a large shape and extremely high manufacturing cost.

[0007]

The inventors of the present invention invented a novel circuit breaker which is small in size and extremely low in manufacturing cost, and applied for a patent on July 3, 1991 (reference number P9107). -009 and P9107-010). The present invention is a novel circuit breaker invented as a result of further research based on the above invention.

[0008]

The present invention uses a pair of separately wound coils of magnetic material that are opposed at a fixed distance. One magnetic material is fixed and the other magnetic material is movable. Also, the separate coils are in the same circuit.

When a current flows through the coil, a magnetic field is generated and the magnetic material is magnetized. When the current flowing in the circuit is normal, the magnetic field of each coil is not strong enough to actuate a pair of opposing magnetic materials.

However, when an overcurrent flows in the circuit, the magnetic field of each coil becomes strong, and the pair of opposing magnetic materials attract each other or repel each other. In this case, since the movable magnetic material is attached to the movable piece for opening and closing the circuit, the movable piece moves according to the displacement of the movable magnetic material to cut off the circuit.

In general, the characteristics required for a magnetic material are exactly opposite to those of a permanent magnet material, and the residual magnetism and hysteresis loss are small. Such magnetic materials include silicon steel sheet (Fe-Si alloy), permalloy (Ni-Fe alloy), supermalloy, sendust (Fe-Si-Al alloy), soft ferrite (MO).
-Fe ₂ O ₄ or MFe ₂ O ₄ ) Here, M is a divalent metal ion, an amorphous magnetic alloy, or the like. In the present invention, any magnetic material may be used, but among them, one having a high magnetic flux density is preferable. .

The reason for forming a pair of magnetic materials in which coils are separately wound is that when an overcurrent flows, the attractive force or repulsive force is doubled by the magnetic forces of the mutual magnetic materials. This is because the number can be reduced and the circuit breaker can be miniaturized. Hereinafter, detailed description will be given according to examples.

[0013]

[Embodiment 1] FIG. 1 is a principle diagram of this embodiment. A coil 3 is wound around the moving magnetic material 1, and a coil 4 is wound around the fixed magnetic material 2. Coil 3 and coil 4 are wound in opposite directions. Therefore, when a current flows through the coil, one magnetic material is magnetized to the N pole and the other magnetic material is magnetized to the S pole.

When the current flowing through the circuit is normal, the magnetic fields generated in the coils 3 and 4 are small, and there is not enough magnetic force to move the moving magnetic material. In this state, the movable piece 5 via the magnetic material movable piece connecting rod 6 contacts the closed contact 7, and the circuit is closed.

When an overcurrent flows in the circuit, the magnetic fields of the coils 3 and 4 become strong, the magnetic materials attract each other, and the moving magnetic materials move downward. Therefore, the movable piece moves to the open circuit contact 8 via the magnetic material movable piece connecting rod to cut off the circuit. The circuit is then closed again by manually returning the movable piece to the closed contact.

If the coils 3 and 4 are wound in the same direction, the two magnetic materials are magnetized to have the same polarity and move in a repulsive direction. In this case, the closed contact and the open contact may be reversed.

[0017]

The present invention has the feature that the number of turns of the coil can be extremely reduced, so that the circuit breaker can be manufactured in a smaller size and at an extremely low cost as compared with the conventional circuit breaker. Further, according to the present invention, since the magnetic force is used to move the movable piece, there is a characteristic that it is not affected by the ambient temperature.

[Brief description of drawings]

FIG. 1 is a principle diagram of an embodiment of a circuit breaker according to the present invention.

FIG. 2 is a cross-sectional view of a conventional oil damper type circuit breaker.

[Explanation of symbols]

1 Moving magnetic material 2 Fixed magnetic material 3 coils 4 coils 5 movable pieces 6 Moving magnetic material movable piece connecting rod 7 closed contact 8 open contacts 9 Moving piece fixed contact 10 load 11 cylinders 12 plugs 13 Plunger 14 spring 15 solenoid coil 16 Amateur

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[Procedure amendment]

[Submission date] September 12, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

[0013]

[Embodiment 1] FIG. 1 is a principle diagram of this embodiment. A coil 3 is wound around the moving magnetic material 1, and a coil 4 is wound around the fixed magnetic material 2. The coil 3 and the coil 4 are wound in the same direction . Therefore, when a current flows through the coil, the two magnetic materials are magnetized in the directions attracting each other.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

If the coils 3 and 4 are wound in opposite directions
When oriented in the opposite direction , the two magnetic materials are magnetized to the same polarity and move in a repulsive direction. In this case, the closed contact and the open contact may be reversed.

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (2)

[Claims] 1. A circuit breaker, characterized in that a pair of opposed magnetic materials, which are wound separately, are used to operate a movable piece that opens and closes the circuit. 2. The circuit breaker of claim 1, wherein the separate coils are in the same circuit.