JPH02114426A - Circuit breaker - Google Patents

Abstract

PURPOSE:To have a circuit breaker with small delay in the tripping motion by furnishing a rotation energizing means to give a torque in No.1 direction to a tripping means so as to produce a component force in the direction perpendicular to the motion of tripping means between it and a base frame. CONSTITUTION:One of two arms 8b of a torsion spring 8 of a rotation energizing means is fitted to and supported by a base frame 1, while the other 8a by a tripping lever 4. Detection of this arm 8a with the tripping lever 4 takes place in a position horizontally apart from a shaft 3 so that the spring 8 energization force produces a component force in the gravitation acting direction on the shaft 3, for ex. situated above the shaft 3 in the gravitation acting direction and producing a torque. Accordingly the fit hole 4a in the tripping lever 4 makes contact in the upper part of the shaft 3, wherein the tolerance between the shaft 3 and fit hole 4a is always concentrated in the lower part of the gravitation acting direction. This permits the tripping lever 4 to make rotating motion immediately without causing this tolerance portion to be first moved horizontally, and thus delay in tripping motion will be lessened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit breaker, and particularly to an improvement in the mounting direction of a spring for applying rotational force to a tripper thereof.

[Prior Art] FIG. 3 shows the structure of a conventional circuit breaker, particularly in the vicinity of the trip bar. The structures of the movable contact drive mechanism, arc extinguishing grid, etc. of the circuit breaker are well known, and therefore illustrations thereof are omitted.

In the figure, a support shaft 3 is fixed to the underframe l, and a trip lever 4 is pivotally supported on the support shaft 3. Trip lever 4
The fitting hole 4a is fitted with the support shaft 3 with a predetermined tolerance. A trip bar 5 is fixed to the trip lever 4 in parallel with the support shaft 3, and the tripper 5 is rotatable around the support shaft 3.

A movable iron piece lO is rotatably supported on the underframe l, and a locking lever 6 is rotatably supported on the shaft 11. There is an electromagnet 2 on the rough underframe l.
and spring loading 13.14. A rotation stopper 15 and the like are fixed. There is a shaft 3 between the spring hook 13 and the tripper 5.
A torsion spring 8 is provided at the center, and a torsion spring 9 is provided between the spring hook 14 and the bent portion 6b of the locking lever 6. Further, the link lever 7 is locked to the locking portion 6a of the locking lever 6, and when the locking lever 6 and the link lever 7 are unlocked, the movable contact connected to the link lever 7 is separated from a stationary contact (not shown as is well known).

Next, the operation of the conventional example will be explained.

The locking lever 6 is biased by a torsion spring 9 in the direction indicated by arrow A so as to rotate counterclockwise. As a result, at the distal end 6c of the locking lever 6, the rotational force of the torsion spring 9 is transmitted to the locking portion 4b of the trip lever 4 in the direction of arrow B, almost horizontally. Further, the tripper 5 is biased with a clockwise rotational force in the direction indicated by an arrow C by a torsion spring 8. However, the trip lever 4 is prevented from rotating clockwise by a rotation stopper 15. As a result, the trip lever 4 moves to the left in the figure due to the urging force indicated by the arrow B, and the fitting hole 4a of the trip lever 4 moves to the left in the figure.
and the support shaft 3 contact each other on the right side of the fitting hole 4a, and the tolerance north between the fitting hole 4a and the support shaft 3 is concentrated on the left side of the fitting hole 4a.

When a large current flows in the electric circuit, the electromagnet 2 is excited,
The movable iron piece 10 is attracted by electromagnetic force in the direction shown by the arrow. When the movable iron piece lO is attracted to the electromagnet 2, the shaft 12
It starts rotating counterclockwise around the end 10a.
presses the tripper 5 in the direction shown by arrow E. When the tripper 5 receives a pressing force in the direction of arrow E, the support shaft 3
The rotation starts counterclockwise around the contact point between the support shaft 3 and the fitting hole 4a, but the contact point between the support shaft 3 and the fitting hole 4a moves along the inner circumferential surface of the fitting hole 4a. The trip lever 4 and the tripper 5 are held horizontally in the figure by the tolerance between the fitting hole 4a and the support shaft 3, as shown by the arrow F, until the trip lever 4 and the tripper 5 reach the state shown by the dotted chain line 4a' in the figure. Moving. Thereafter, as shown by arrow G, trip lever 4 and tripper 5 rotate counterclockwise. When the trip lever 4 rotates counterclockwise, the locking portion 4b rotates in the direction shown by arrow H and separates from the tip 6c of the locking lever 6. When the distal end 6c of the locking lever 6 is released from locking, the locking lever 6 starts to rotate counterclockwise as shown by the arrow ■ due to the rotational force of the torsion spring 9.

When the locking lever 6 rotates counterclockwise and the locking of the link lever 7 by the locking portion 6a is released, the link lever 7
rotates clockwise in the figure, as shown by arrow J. Rotation of the link lever 7 separates the movable contact from the fixed contact, and the electric circuit is cut off (not shown as is well known).

[Problem to be solved by the invention] Since the conventional circuit breaker is configured as described above, the trip lever and tripper do not start rotating immediately after a large current is detected and the electromagnet is excited. First, the trip lever and the tripper move substantially horizontally by the tolerance between the support shaft that supports the trip lever and the fitting hole, and only after that does the tripper begin to rotate.

Therefore, there was a problem in that the tripping operation was delayed by the time required to horizontally move the tolerance between the support shaft and the fitting hole.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a circuit breaker with less delay in tripping operation.

[Means for Solving the Problems] A circuit breaker according to the present invention has a support shaft fixed to an underframe, a fitting hole portion that fits into the support shaft, and a shaft rotatable about the support shaft. a supported trip means; a rotational force biasing means provided between the underframe and the trip means for applying a rotational force in a first direction to the trip means so as to generate a force component perpendicular to the direction of movement of the trip means; , a driving means that rotates the tripping means in a second direction opposite to the first direction when a large current exceeding a predetermined value is detected; Contactor driving means is provided which is unlocked by rotation of the tri-knob means in the second direction and causes the movable contactor to separate from the fixed contactor.

[Operation] The trip means is, for example, a trip lever rotatably supported on a support shaft and a tripper fixed to the trip lever in parallel to the support shaft.

The rotational force biasing means is, for example, a torsion spring, and one of its two arms is engaged with the underframe, and the other arm is engaged with and supported by the breaker. The engagement position between the arm of the torsion spring and the trip lever is such that the biasing force of the spring generates a component force in the direction of gravity on the support shaft, for example, above the support shaft in the direction of gravity and in the direction of rotational force. It is set at a position away from the supporting shaft in the horizontal direction so as to produce the following effects.

As a result, the fitting hole of the trip lever contacts the upper part of the spindle, the tolerance between the fitting hole and the spindle is always concentrated at the bottom in the direction of gravity, and the trip lever is centered around the spindle. A rotational force is applied to rotate in a first direction (eg, clockwise).

The driving means is, for example, an electromagnet and a movable iron piece, and when a large current of a predetermined value or more flows through the electric circuit, the electromagnet is excited and the movable iron piece is attracted to the electromagnet. The movable iron piece is rotated, for example, around a predetermined axis by electromagnetic force. During its rotation, the movable iron contacts the trip bar, causing the trip bar and trip lever to rotate in a second direction opposite to the first direction against the rotational force of the spring.

The contactor driving means includes, for example, a spring for separating the movable contactor from the fixed contactor, a link lever, a locking lever, etc., and the locking lever usually prevents the movement (locks it) by a trip tray It-. ) has been done. By rotating the trip lever in the second direction, the lock lever is released from its lock, and the movable contact is driven by the biasing force of the spring and separated from the fixed contact.

[Example] The circuit breaker according to the present invention is shown in the first example showing the circuit breaker according to the present invention.
This will be explained using FIG.

In FIG. 1, the electromagnet 2, the movable iron piece lO, the spring 20 that biases the movable iron piece 10 in the direction opposite to the electromagnetic force of the electromagnet 2, etc. constitute a driving device. When an overcurrent of a predetermined value or more flows through the electric circuit in which the circuit breaker is installed, the electromagnet 2 is excited, and the movable iron piece 10 is attracted to the electromagnet 2 against the biasing force of the spring 20.

The trip lever 4 and the trip bar 5 constitute a trip device. The trip lever 4 is rotatably supported in its fitting hole 4a by a support shaft 3 fixed to the underframe l, and is rotated in a predetermined direction, for example, in a clockwise direction in FIG. A rotational force is applied in the direction.

The locking lever 6 is pivotally supported by a support shaft 11, and is supported by a torsion spring 9.
is applied with a counterclockwise rotational force. The locking lever 6 is normally prevented (locked) from rotating counterclockwise by the trip lever 4.

The link lever 7, 21, 22, the spring 23, etc. constitute a contact drive, and the link lever 22 is connected to a movable contact 24. The link lever 7 is normally prevented from rotating (locked) by the locking lever 6.

Since the link lever 7 is prevented from rotating, the link levers 21 and 22 are restrained in a predetermined position, and the tensile force of the tension spring 23 is not transmitted to the movable contact 24. The movable contact 24 makes contact with the fixed contact 25 to conduct the electric circuit.

FIG. 2 is an enlarged view of the main parts near the trip lever 4 and the tripper 5. Note that the shapes and positional relationships of each part are simplified to explain the present invention, and do not match those of an actual circuit breaker.

In FIG. 2, one arm 8b of the two arms of the torsion spring 8 is in contact with a spring hook 13 provided on the underframe 1,
The other arm 8a contacts the trip lever 4 at point 4C. The torsion spring 8 applies a rotational force to the trip lever 4 at point 4C in the direction indicated by the arrow. The rotational force indicated by the arrow can be divided into a vertical component indicated by the arrow and a horizontal component indicated by the arrow M. On the other hand, the locking lever 6 is biased with rotational force in the direction indicated by arrow A by a torsion spring 9. The locking lever 6 transmits the biasing force of the torsion spring 9 substantially horizontally to the locking portion of the trip lever 4 as shown by arrow B at its tip 6c. The horizontal leftward force, indicated by arrow B, acts to reduce the horizontal component of the biasing force of torsion spring 8, indicated by arrow M. Further, the trip lever 4 is prevented from rotating clockwise by a rotation stopper 15 fixed to the underframe l. As a result, the trip lever 4 receives a vertical component of the biasing force of the torsion spring 8 at the contact point between the fitting hole 4a and the support shaft 3 in the direction of gravity as shown by the arrow N. . Generally, the fitting hole 4 of the trip lever 4
a and the support shaft 3 are fitted with a predetermined tolerance, but the trip lever 4 normally comes into contact with the support shaft at or near the highest point due to the biasing force indicated by the arrow N, and the tolerance is determined by the direction of gravity. concentrated at the bottom.

Next, the operation of the embodiment will be explained.

When a large current of a predetermined value or more flows through the electric circuit, the electromagnet 2 is excited, and the electromagnetic force attracts the movable iron piece lO in the direction shown by the arrow. When the movable iron piece 10 is attracted by the electromagnet 2, it begins to rotate counterclockwise about the support shaft 12, and its end 10a presses the tripper 5 in the right direction as indicated by arrow E. The rightward pressing force indicated by arrow E is for rotating the trip lever 4, the lever, and the lever 5 counterclockwise without delay with respect to the contact point between the fitting hole 4a of the trip lever 4 and the support shaft 3. acts as a rotating force.

Therefore, the trip lever 4 and the tripper 5 immediately rotate counterclockwise as shown by arrow G. When the trip lever 4 rotates counterclockwise, the locking portion 4b rotates in the direction shown by the arrow I and separates from the tip 6c of the locking lever 6. When the distal end 6c of the locking lever 6 is released from the lock, the rotational force of the torsion spring 9 causes the locking lever 6 to move in the direction of the arrow! Start rotating counterclockwise as shown. When the locking lever 6 rotates counterclockwise and the locking of the link lever 7 by the locking portion 6a is released, the link lever 7 rotates clockwise as shown by arrow J. The rotation of the link lever 7 releases the restraint of the link levers 21 and 22 shown in FIG. 1, and the tensile force of the tension spring 23 separates the movable contact 24 from the fixed contact 25, cutting off the electric circuit.

[Effects of the Invention] As described above, according to the present invention, the spring (8) for applying a rotational force to the trip lever (4) generates a component force (L) in a direction perpendicular to the moving direction of the trip lever (4). ), so the tri-knob lever (4)
The fitting hole (4a) and the support shaft (3) are always in contact with each other at the upper part of the support in the direction in which the power is applied.

Therefore, compared to the conventional example, the tolerance between the fitting hole of the trip lever and its support shaft does not have to be moved horizontally, the trip lever rotates immediately, and the delay in tripping operation is extremely small. have

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of a circuit breaker according to the present invention, FIG. 2 is an enlarged partial sectional view of the vicinity of the trip lever of the circuit breaker shown in FIG. 1, and FIG. 3 is a conventional circuit breaker. FIG. 3 is a partial cross-sectional view showing the vicinity of the trip lever of the device. In the figure, 1 is an underframe, 2 is an electromagnet, 3 is a support shaft, 4 is a trip lever, 5 is a tripper, 6 is a locking lever, and 8 is a torsion spring.

Claims (1)

[Claims] (1) A support shaft fixed to the underframe, a trip means that has a fitting hole that fits into the support shaft and is rotatably supported around the support shaft, and a space between the underframe and the trip means. rotational force biasing means for applying a rotational force in a first direction to the tripping means so as to generate a component force in a direction perpendicular to the moving direction of the tripping means; A driving means that rotates in a second direction opposite to the first direction, and is normally locked by a tripping means, and is released by rotation of the tripping means in the second direction when a large current is detected. , a contact drive means for separating the movable contact from the fixed contact;