JP2006156069A - Electromagnetic trip device for circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker that has a simple and inexpensive trip means having an increased instantaneous operating current value without an increase in the number of parts and without major reshaping and machining of a movable iron piece and an electromagnetic frame. <P>SOLUTION: The electromagnetic trip device disposed in the circuit breaker to detect an overcurrent and act on a latch of a make/break mechanism as a trip operation breaking a cable run comprises the electromagnetic frame enclosing a conductor forming a part of the cable run substantially in a U shape, and the movable iron piece that is normally loaded by a loading member in a direction to hold a gap against the electromagnetic frame and, when an overcurrent flows in the conductor, attracted to the electromagnetic frame, and is provided with a latch action part adapted to act on the latch under the attraction. A first gap and a second gap formed between one end and the other end of the U-shaped electromagnetic frame and the movable iron piece are defined in different sizes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention is applied to an instantaneous tripping device of a circuit breaker, and even when a large inrush current is generated due to the use of a specific power transformer in the electric circuit, it does not operate unnecessarily, and due to a short circuit of the cord part, etc. The present invention relates to an instantaneous trip device that performs a normal operation when a large current is generated.

As shown in Fig. 1 of Patent Document 1, the tripping device is composed of bimetal or electromagnetic elements. When an accident current such as overcurrent or short-circuit current flows in the circuit where the circuit breaker is connected, The engagement between the contact portions acting on the tripping member of the mechanism portion is released, and the contacts are released from the closed state to the open state.
In FIG. 1 of Patent Document 1, the tripping device includes an electromagnetic frame disposed so as to surround a bimetal as a conductor in a substantially U-shape, and a movable iron piece connected to the electromagnetic frame by an elastic member. Consists of

A gap in the magnetic circuit is equally provided between both ends of the substantially U-shaped electromagnetic frame and the movable iron piece. When a current exceeding a predetermined value flows through the conductor, Drive by suctioning each other.

The trip device does not operate with an inrush current in the electric circuit, and is provided so that the trip device operates only when a large current is generated due to a short circuit in the electric circuit.

Japanese Patent Laying-Open No. 2002-56763 (FIG. 1)

However, depending on the connection environment, the inrush current may be very large compared to a normal load. For example, when a power distribution method using a large number of smoothing capacitors or a power transformer used for a linear power supply is connected, the circuit breaker is turned on and a large charging current is applied at the moment the voltage is applied. The inner core of the transformer causes magnetic saturation and an inrush current is generated alone.

When such a connection is made, that is, in the case of a connection with a specific load, the drive start current value in the instantaneous tripping device needs to be adjusted higher than usual.

When adjusting the drive start current value of the instantaneous tripping device, it is necessary to change the internal structure by changing or adding parts, or to change the shape of the movable iron piece or the electromagnetic frame.

Along with this, there have been problems such as an increase in the number of parts and associated costs, and a significant change in shape and processing of the movable iron piece and the electromagnetic frame, which incurs associated costs.

Therefore, the invention of the present invention is an easy and inexpensive trip with a high instantaneous operating current value, without increasing the number of parts, and without significantly changing the shape and processing of the movable iron piece and the electromagnetic frame. The object is to provide a circuit breaker comprising means.

In order to achieve the above object, in the present invention, an electromagnetic trip device provided in a circuit breaker that detects an overcurrent, acts on a latch of a switching mechanism to perform a tripping operation, and opens and closes an electric circuit. In this case, the trip device includes an electromagnetic frame that surrounds a conductor constituting a part of the electric circuit in a substantially U-shape, and an urging member that is always urged by a biasing member in a direction keeping a gap from the electromagnetic frame. And a movable iron piece provided with a latch action portion that acts on the latch at the time of suction. An electromagnetic trip device for a circuit breaker is provided, characterized in that the gaps are provided so that the sizes of the first gap and the second gap formed between the one end and the other end and the movable iron piece are different. Is.

As a result, when the magnetic material is attracted, one of the gaps becomes zero and comes into contact with the other, and the other gap comes into contact with the other, so that the drive time of the instantaneous trip device is delayed by stepwise driving. Can be operated as follows.

Further, the latch action portion provided on the movable iron piece is formed at a position biased to either the first gap or the second gap, and the size of the gap is on the side where the action portion is formed. The electromagnetic trip device for a circuit breaker according to claim 1, wherein the gap is provided to be larger than the other.

As a result, when the movable iron piece is attracted to the substantially U-shaped electromagnetic frame, it is driven so that the gap on one side is abutted and then the gap on which the action part is formed abuts. The part can be operated to delay the time that it acts on the latch.

3. The circuit breaker according to claim 2, wherein in the gap on the side where the action portion is formed, the gap is provided with a part of the movable iron piece so that the size of the gap is different. An electromagnetic trip device may be provided.

Thereby, it is possible to configure a tripping device in which the instantaneous operating current value is increased only by performing projection processing on the movable iron piece of the instantaneous tripping device used as a standard.

The biasing member is configured by using a plate spring-like elastic member, and the electromagnetic frame and the movable iron piece are connected by using the plate spring-like elastic member. An electromagnetic trip device may be provided.
As a result, when the movable iron piece is attracted to the electromagnetic frame, after the gap on one side becomes zero and comes into contact, a force that twists the leaf spring is generated, thereby controlling the movement of the movable iron piece more effectively. be able to.

An electromagnetic trip device for a circuit breaker is characterized in that a partial projection is provided from an electromagnetic frame in place of a movable iron piece provided with a partial projection. May be provided.
Thus, by providing a part of the protrusion on the side of the electromagnetic frame in advance, an instantaneous trip device capable of handling a large inrush current can be easily configured.

Circuit breaking with tripping means that is easy, inexpensive, and has a high instantaneous operating current value, without increasing the number of parts, and without making a major shape change or processing to the movable iron piece and the electromagnetic frame. Can be provided.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the internal structure of a circuit breaker incorporating the trip device of the present invention.
The circuit breaker 1 is provided so that a cover a100a and a cover b100b (not shown) that are divided in the longitudinal direction face each other when the direction connecting the power supply side and the load side is the longitudinal direction. The body is constructed. Each component constituting the circuit breaker 1 is accommodated so as to be inserted into the divided cover a100a and cover b100b.

Reference numerals 101a and 101b denote power supply side terminals to which a current is supplied from a bus or a branch line that supplies a current to each branch switch provided in the distribution board.

Reference numerals 102a and 102b denote load-side terminals that are connected to the load-side electric circuit and supply current to the load device.

Reference numeral 103 denotes a contact device that includes a movable contact 1032a and 1032b having a movable contact, and a fixed contact 1031a and 1031b having a fixed contact that is opposed to the movable contact and opens and closes an electric circuit.

Reference numeral 104 denotes an opening / closing mechanism that opens and closes the contact device 103, and includes a link member that opens and closes the contact device 103 by an operation handle 1041 that is disposed on the body of the circuit breaker.

Reference numeral 105 denotes a thermal electromagnetic trip device that acts on the switching mechanism portion 104 to open the movable contact when an overcurrent occurs, and includes a tripping member 1051 and a conductor that form a latch portion 1052 with the switching mechanism portion 104. It includes a certain bimetal 1055, an electromagnetic frame 1054, a movable iron piece 1053, and a movable iron piece receiver 1056 made of an elastic body that connects the electromagnetic frame 1054 and the movable iron piece 1053. In this embodiment, the first magnetic body is an electromagnetic frame 1054 and the second magnetic body is a movable iron piece 1053.

In the circuit breaker 1, the power terminal 101b side is the power pole side, and the power terminal 101a is the neutral pole side. The power supply terminals 101a and 101b are each connected to the contact device 103 via a conductor, and are connected to the load terminals 102a and 102b via the trip mechanism 105 on the power supply electrode side from the contact device.

FIG. 2 shows a structural diagram of an electromagnetic trip device according to the present invention.
FIG. 2A is a view of the electromagnetic trip device 105 viewed from the direction facing the internal structure diagram of FIG. FIG. 2B is a view of the tripping device 105 viewed from the opposite direction from the direction facing the internal structure diagram of FIG. 2C is a perspective view seen from the left side of FIG. 1A, and FIG. 2D is a perspective view seen from the right side of FIG. 2B. FIG. 2E is a view from above.

The tripping device 105 includes an electromagnetic frame 1054 and a movable iron piece 1053 that elastically holds the movable iron piece 1053 and is attached to the electromagnetic frame 1054 and is provided with a latch action portion 1057 at one end, and a latch portion 1052. And a tripping member 1051 whose one end is rotatably held.

The electromagnetic frame 1054 is provided so as to form a magnetic circuit with the movable iron piece 1053, and a bimetal 1055 as a conductor is provided so as to penetrate the magnetic circuit. The electromagnetic frame 1054 has a substantially U-shape. It is formed to surround.

The movable iron piece 1053 is fixedly mounted on a movable iron piece receiver 1056 made of an elastic member by caulking, and is elastically held so as to face the electromagnetic frame 1054. As shown in FIG. Rotating operation is performed around the movable iron piece rotating shaft 1054d, and the magnetic circuit is always urged in a direction in which a gap is provided in the magnetic circuit, that is, a clockwise direction in the drawing. That is, the movable iron piece 1053 is held at a predetermined position by a leaf spring-like elastic member so as to always keep a gap with the electromagnetic frame.

The movable iron piece 1053 is provided with an extended latch action portion 1057, and on the side opposite to the side where the latch action portion is provided, the protruding portion 1058 extends in the direction in which the gap (gap) with the electromagnetic frame 1054 becomes narrower. Is provided.

The protrusion 1058 is formed by subjecting the movable iron piece 1053 to projection processing. For this reason, when a specific load is connected and an inrush current is expected to increase, the projection can be easily formed by performing projection processing on the standard specification product later.

Further, by adjusting the protruding amount of the protruding portion, it is possible to control the attraction of the movable iron piece to the electromagnetic frame piece according to the magnitude of the inrush current.

In addition, when a special specification is provided from the beginning instead of providing a protruding portion on the movable iron piece side, a gap formed between the electromagnetic frame 1054 and the movable iron piece 1053 on the electromagnetic frame side ( You may provide so that a protrusion part may be formed so that a gap) may become small. In this way, it is possible to provide an electromagnetic trip device that does not require post-processing and that corresponds to the inrush current in the specific wiring configuration.

First, the trip member 1051 has a portion where the latch portion 1052 is formed from the trip member rotating shaft 1051d so that the latch action portion 1057 provided on the movable iron piece 1053 comes into contact with the electromagnetic frame 1054. A portion is provided that is bent into a substantially U-shape and has a contact portion. The abutting portion is provided with two locations, a bimetal abutting portion 1051e where the bimetal 1055 is bent and abutting, and a latching portion abutting portion 1051f where the latching portion 1057 abuts.

When the projection shape is not formed, the two gaps (gap) formed between both ends of the electromagnetic frame 1054 formed in a substantially U-shape and the movable iron piece 1053 are equal and flow through the conductor. When the movable iron pieces are driven in accordance with the magnitude of the current, the gaps are driven so that the gaps are equally narrow, and the movable iron pieces 1053 are in contact with both ends of the electromagnetic frame 1054 at the same time.

Next, the operation of the movable iron piece 1053 when an inrush current flows will be described. When an inrush current sufficient to drive the movable iron piece 1053 flows through the conductor, the electromagnetic frame 1054 and the movable iron piece 1053 are attracted to each other by the electromagnetic attraction force. Since the movable iron piece 1053 is held by a leaf spring-like elastic member with respect to the electromagnetic frame, when the electromagnetic attraction force due to the inrush current overcomes the holding force of the leaf spring-like elastic member, the electromagnetic frame It moves so as to be attracted in the direction of 1054.

At this time, since the movable iron piece 1053 is provided with the protruding portion 1058, the protruding portion 1058 comes into contact with the electromagnetic frame 1054 first. After that, if the electromagnetic attraction force continues, the force acts in the direction of twisting the leaf spring-like elastic member, and if this torsional force is overcome, the movable iron piece moves in the direction in which the gap also narrows in the other gap. As a result of the suction, the latch action portion 1057 abuts on a latch action portion abutting portion 1051 f provided on the tripping member 1051.

As described above, there is a two-stage movement until the latch action portion 1057 comes into contact with the latch action portion contact portion 1051f provided on the tripping member 1051, and the electromagnetic attraction of the movable iron piece in the normal instantaneous trip device. Compared to the force, the electromagnetic attraction force of the movable iron piece in the present embodiment can be configured to be larger.

Normally, the inrush current is attenuated by about two waves at the commercial frequency, so the electromagnetic attractive force does not last long, and the electromagnetic attractive force decreases with time. For this reason, the protruding portion 1058 provided on the movable iron piece first comes into contact with the electromagnetic frame 1054, and further, the torsional force of the elastic member in the form of a leaf spring works to prevent the movable iron piece from adsorbing to the electromagnetic frame. Even when the inrush current increases when a specific load is connected, it is possible to provide an electromagnetic trip device without performing unnecessary operations.

Next, the operation of the tripping device 105 due to a short circuit current will be described.
If a short circuit current occurs, the trip device must operate normally. Since the short-circuit current is generally larger than the inrush current, the electromagnetic attractive force also increases in proportion. For this reason, the influence of the provision of the projecting portion is insignificant, the projecting portion is brought into contact with the electromagnetic frame and the torsional force is overcome by the leaf spring-like elastic member, and the latch action portion 1057 is provided on the tripping member 1051 It abuts against the latch action portion abutting portion 1051f.

Referring to FIG. 2, when a current flows through a bimetal 1055 that is a conductor substantially surrounded by the electromagnetic frame 1054 and the movable iron piece 1053, a magnetic circuit is formed in the electromagnetic frame 1054 and the movable iron piece 1053. When a current exceeding a predetermined value flows through the bimetal 1055, that is, when a short-circuit current or the like is generated, an attractive force is generated so as to attract the electromagnetic frame 1054 and the movable iron piece 1053, and the movable iron piece 1053 is moved by the attractive force. The first abutting portion 1053a of the movable iron piece 1053 is abutted with the first abutting portion 1051a of the tripping member 1051 by rotating about the rotating shaft 1054d. An example is shown in FIG. 3A is a view of the tripping device 105 viewed from the direction facing the internal structure diagram of FIG. 1, and FIG. 3B is opposite to the direction facing the internal structure diagram of FIG. It is the figure which looked at the trip device 105 from the direction.

4 (FIG. 4A) is a view of the tripping device 105 viewed from the direction facing the internal structure diagram of FIG. 1. FIG. 4B is opposite from the direction facing the internal structure diagram of FIG. 4C is a view of the tripping device 105 seen from the direction of FIG. 4 (c) is a view seen from above, like FIG. 1 (e). When the movable iron piece 1053 rotates, the movable iron piece 1053 pushes the tripping member 1051, the tripping member 1051 rotates about the tripping member rotation shaft 1054 d as a rotation center, and the second contact portion of the movable iron piece 1053. 1053b contacts the second contact portion 1054b of the electromagnetic frame 1054.

5 (FIG. 5A) is a view of the tripping device 105 viewed from the direction facing the internal structure diagram of FIG. 1. FIG. 5B is opposite from the direction facing the internal structure diagram of FIG. 5 (c) is a view of the tripping device 105 seen from the direction of FIG. 5. FIG. 5 (c) is a view seen from above like FIG. 1 (e). When the movable iron piece 1053 is rotated, the left side of the electromagnetic iron piece is in contact with the electromagnetic frame 1054 and cannot move, but since the attractive force is still working, the right side is attracted to the electromagnetic frame and twisted. The third abutting portion 1053c of the movable iron piece 1053 and the third abutting portion 1054c of the electromagnetic frame 1054 come into contact with each other by the movement, and the movable iron piece 1053 pushes the tripping member 1051 as it is, thereby releasing the latch. Yes.

As described above, normally, both sides of the movable iron piece 1053 are in contact with the electromagnetic frame 1054 at the same time, and the detaching member 1051 is detached. However, in the present invention, what is the side where the detaching member 1051 is pushed down? The latch action part 1057 provided on the movable iron piece 1053 and the latch action part provided on the tripping member 1051 are brought into contact with the electromagnetic frame 1054 once on the opposite side and act to twist the leaf spring-like elastic member. To provide an electromagnetic trip device that does not perform an unnecessary operation even when a rush current in a specific connection environment is large because the contact portion 1051f is brought into contact with the trip member 1051. Can do.

In the present invention, an electromagnetic trip device is configured for the purpose of preventing unnecessary operation caused by a large inrush current. However, unnecessary operation at temporary overload current is prevented within the allowable current range in the circuit. It can be applied as a role to perform. In addition, the protruding amount of the protruding part is fixed, but by providing the protruding amount as variable, it is possible to centralize the management of parts and improve the production efficiency by dropping into the standard specification .

The internal structure figure of the circuit breaker which provided the electromagnetic trip device of this invention. 1 is a structural diagram of a tripping device of the present invention. FIG. 1 shows the operation of the tripping device. FIG. 2 shows the operation of the tripping device. FIG. 3 shows the operation of the tripping device. Circuit breaker with conventional electromagnetic trip device

Explanation of symbols

1 Circuit breaker 100a Cover a
100b Cover b
101a power supply side terminal 101b power supply side terminal 102a load side terminal 102b additional side terminal 103 contact device 1031a fixed contact 1031b fixed contact 1032a movable contact 1032b movable contact 104 opening / closing mechanism 105 trip device 1051 trip member 1051a first Contact part 1051d Tripping member rotating shaft 1051e Bimetal contact part 1051f Latch action part contact part 1052 Latch part 1053 Movable iron piece 1053a First contact part 1053b Second contact part 1053c Third contact part 1054 Electromagnetic frame 1054b Second contact part 1054c Third contact part 1054d Movable iron piece rotating shaft 1055 Bimetal 1056 Movable iron piece receiver 1057 Latch action part 1058 Projection part

Claims (5)

In an electromagnetic trip device provided in a circuit breaker that detects an overcurrent, acts on a latch of a switching mechanism to perform a tripping operation, and opens and closes an electric circuit,
The trip device includes a first magnetic body disposed around a conductor constituting a part of the electric circuit,
A second magnetic body that is attracted to the first magnetic body by electromagnetic attraction when an overcurrent flows through the conductor;
The second magnetic body is always urged by the urging member in a direction to keep a gap between the first magnetic body and the second magnetic body,
A latching action part that acts on the latch at the time of suction is provided and configured.
An electromagnetic attraction of a circuit breaker, characterized in that the gap is provided so that the sizes of the first gap and the second gap provided between the first magnetic body and the second magnetic body are different. Removal device. The first magnetic body is an electromagnetic frame, the second magnetic body is a movable iron piece, and the electromagnetic frame is provided so as to surround the conductor in a substantially U-shape,
The latch action part provided on the movable iron piece is formed at a position biased to either the first gap or the second gap, and the size of the gap is determined by the gap on the side where the latch action part is formed. The electromagnetic trip device for a circuit breaker according to claim 1, wherein the size of the circuit breaker is larger than that of the other. 3. The gap on a side different from the side on which the latch action portion is formed, wherein the gap has a part protruding from a movable iron piece so that the size of the gap is different. Circuit breaker electromagnetic trip device. The biasing member is configured using a leaf spring-like elastic member, and is configured by connecting the electromagnetic frame and the movable iron piece using the leaf spring-like elastic member. An electromagnetic trip device for a circuit breaker according to claim 2 or claim 3. An electromagnetic trip device for a circuit breaker according to claim 3, wherein a part of the projecting part is provided from the electromagnetic frame in place of the movable iron piece provided with a part of the projecting part. Electromagnetic trip device.