JP2008098065A - Circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small double-break circuit breaker capable of keeping the workload of a switching mechanism equivalent to that of a single-break circuit breaker, and having a simple structure. <P>SOLUTION: This circuit breaker is provided with a moving contact 2 including a moving contact point 2a on one end side, supported rotatably by using a shaft 3 arranged on the other end side as a supporting point, and switched and driven by a switch mechanism. The circuit breaker is also provided with a fixed contact 5 including a fixed contact point 5a. The circuit breaker is still also provided with an intermediate contact 7 including a first intermediate contact point 7a contacting the moving contact point 2a on one end side, and a second intermediate contact point 7b contacting the fixed contact 5a on the other end side. The circuit breaker is further provided with a return spring 12 energizing the intermediate contact 7 toward the fixed contact 2. The circuit breaker is still further provided with a contact spring 11 energizing the moving contact 2 to energize the intermediate contact 7 toward the fixed contact 5 through the first intermediate contact point 7a. The intermediate contact 7 is supported movably along a direction headed to the first intermediate contact point 7a from the second intermediate contact point 7b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a circuit breaker in which a movable contact is driven by an electromagnetic repulsive force and a contact is opened.

  Circuit breakers include a one-point circuit breaker that opens one contact and a two-point circuit breaker that opens two contacts.

  A conventional one-point circuit breaker includes a pair of open / close contact pieces that can be contacted and separated (see, for example, Patent Document 1).

  FIG. 4 is a side sectional view showing an example of a conventional one-point circuit breaker. As shown in FIG. 4, the circuit breaker includes a fixed contact 104 fixed to the fixed contact 103 and a movable contact 105 fixed to the movable contact 106 and capable of contacting / separating from the fixed contact 104. .

  When a large short-circuit current flows through the circuit breaker, the movable contact 105 is separated from the fixed contact 104 and an arc is generated. Since the arc can be efficiently diffused and cooled in the arc extinguishing apparatus 102, the arc can be extinguished early and the short-circuit current can be interrupted.

  As for the two-point circuit breaker, there is a circuit breaker provided with at least two sets of electromagnetic repulsion mechanisms that rotate the current limiting contact block by using the electromagnetic repulsive force generated on both sides of the rotation center of the current limiting contact block as a couple. It has been proposed (see, for example, Patent Document 2).

  FIG. 5 is a side sectional view showing an example of a conventional two-point circuit breaker. As shown in FIG. 5, the circuit breaker includes a first current-limiting contact base 212 having a pivot center supported by a pin 217 and a second current-limiting contact base 222 supported by the pin 221. When a large current flows in the circuit breaker due to a short circuit accident, the pin 217 that serves as the rotation center of the first current limiting contact block 212 and between the first contact block 215 and the end 212a of the first current limiting contact block Electromagnetic repulsive force due to a short-circuit current is generated at two locations between the end 212b of the first current-limiting contact base and the movable contact base 209, which are located on the opposite side of the first current-limiting contact base. The pin 212 is rotated counterclockwise around the pin 217 as a rotation center and is released at high speed. Further, the end portion 222 a opposite to the end portion 222 b with respect to the rotation center of the second current limiting contact block 222 between the first contact block 215 and the opposite end portion 222 b of the second current limiting contact block 222. Electromagnetic repulsive force is generated at two points between the first contact point 223 and the fixed contact side of the second contact point 223, and the second current-limiting contact point 222 is separated at high speed in the clockwise direction with the pin 221 as the rotation center.

  In addition, a rotating contact bridge, a pair of fixed contacts corresponding to the contact bridge, and when a short-circuit current flows, current is supplied to the fixed contacts arranged to generate electromagnetic force that repels the contact bridge to the repulsive open position. Conductor to be input, rotary drive rod that has a hole in the horizontal axis that accommodates the contact bridge with a gap and protrudes the contact bridge from both sides, and the contact bridge on the fixed contact at the closing position of the circuit breaker And at least a pair of tension springs that are fixed between the pivot drive rod and the contact bridge and cause the contact bridge to rotate by the action of electromagnetic force rebounding to the repulsive open position. A circuit breaker has been proposed (see, for example, Patent Document 3).

  FIG. 6 is a side sectional view showing another example of a conventional two-point circuit breaker. As shown in FIG. 6, the circuit breaker includes a rotating contact bridge 313. Further, a pair of fixed contacts 311 and 312 corresponding to the contact bridge 313 are provided. In addition, conductors 325 and 324 are provided to input current to the fixed contacts 311 and 312 so as to generate an electromagnetic force that repels the contact bridge 313 to the repulsive open position when a short-circuit current flows. Moreover, the rotation drive rod 320 which has the hole of the horizontal axis direction which accommodates the contact bridge 313 with a clearance gap is provided. The rotation drive rod 320 protrudes the contact bridge 313 from both sides. In addition, in order to provide the contact pressure of the contact bridge 313 on the fixed contacts 311 and 312 in the circuit breaker closing position, the contact bridge 313 is fixed between the rotation driving rod 320 and the contact bridge 313 and rebounds to the repulsion open position. A pair of tension springs 322 and 323 that cause the contact bridge 313 to rotate by the action of electromagnetic force is provided.

A current flowing through the conductor 324 at a certain moment flows through the closed fixed contact portion 328, the movable contact portion 331, the contact bridge 313, the closed movable contact portion 332, and the fixed contact portion 329, It is output to the opposite side through the body 325. In the terminations 326 and 327, a current having a polarity opposite to that flowing through the contact bridge 313 flows, and a repulsive force is generated to move the contact bridge 313 toward the open position. This looped tangent in the range of the fixed contact portion 328, the movable contact portion 331 and the movable contact portion 332, the fixed contact portion 329 generates a magnetic arc discharge magnetic field directed toward the arc extinguishing chamber. The operation mechanism (not shown) is connected to a rotation drive rod 320 that controls the rotation, and as a result, the fixed contact portion 328, the movable contact portion 331, the movable contact portion 332, and the fixed contact portion 329 are opened and closed. Is made.
JP-A-8-273513 Japanese Patent Laid-Open No. 3-182028 Japanese Patent Laid-Open No. 6-52777

  The circuit breaker shown in FIG. 4 is a one-point circuit breaker as described above, and is inferior in breaking performance as compared to a two-point circuit breaker. On the other hand, the circuit breaker shown in FIG. 5 is a combination of a pair of contact blocks and a pair of current-limiting contact blocks that are repelled and separated by a large current. The structure is complex and the height of the contact blocks is occupied. The space is large, and the external shape of the circuit breaker increases. In addition, the circuit breaker shown in FIG. 6 opens and closes a rotary drive rod that houses a contact bridge having movable contact portions at both ends by an opening and closing mechanism, but the contact force of the movable contact portion is doubled. In order to open and close, a double opening and closing force is required, and an opening and closing mechanism that performs twice as much work as a one-point circuit breaker is required.

  Therefore, a main object of the present invention is to provide a small two-point circuit breaker having a simple structure and keeping the work of the switching mechanism equal to that of the one-point circuit breaker.

  A circuit breaker according to the present invention includes a movable contact that includes a movable contact on one end side, is rotatably supported about a shaft provided on the other end side, and is opened and closed by an opening / closing mechanism. A fixed contact including a fixed contact is provided. In addition, an intermediate contact is included that includes a first intermediate contact that contacts the movable contact on one end side and a second intermediate contact that contacts the fixed contact on the other end side. In addition, a first member that biases the intermediate contact toward the fixed contact is provided. Moreover, the 2nd member which urges | biases a movable contact is provided so that an intermediate | middle contact may be urged | biased to the fixed contact side via a 1st intermediate contact. The intermediate contact is supported so as to be movable along a direction from the second intermediate contact toward the first intermediate contact.

  In this case, a movable contact and a stationary contact are configured in the same manner as a conventional one-point circuit breaker, and a two-point circuit breaker can be configured by adding an intermediate contact. That is, it is possible to provide a two-point circuit breaker having a high breaking performance with a simple structure.

  The circuit breaker according to the present invention has the same dimensions as the one-point circuit breaker in the lateral direction, and the height direction is increased by the dimension of the intermediate contact. Compared to a container, it can be downsized and save space. In addition, since the current path is shorter than that of the conventional two-point circuit breaker, the necessary materials can be reduced, and the manufacturing cost can be reduced.

  Further, since the movable contact is urged toward the fixed contact by the second member and the intermediate contact is also urged toward the fixed contact, the movable contact of the movable contact and the first of the intermediate contact are also urged. The contact force with the intermediate contact is equal to that of the conventional one-point circuit breaker. That is, the work required when opening and closing the movable contact by the opening and closing mechanism is equivalent to that of the conventional one-point circuit breaker. Therefore, it is possible to provide a two-point circuit breaker in which the load on the opening / closing mechanism is suppressed to be equal to that of the one-point circuit breaker.

  As described above, according to the circuit breaker of the present invention, the two-point circuit breaker with high breaking performance can be made small and simple, and the load on the switching mechanism can be suppressed to the same level as the one-point circuit breaker. be able to.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing the configuration of a circuit breaker according to an embodiment of the present invention. FIG. 2 is a perspective view showing the configuration of the contact device constituting the circuit breaker shown in FIG. FIG. 3 is a schematic diagram showing a blocking operation of the contact device. In FIG. 3, (a) is a side view of the contact device in a closed state, (b) is a side view showing the disconnecting operation process of the contact device, and (c) is a side view after the contact device is completely disconnected. Are shown respectively. As indicated by arrows in FIG. 1, when the circuit breaker is in a closed state, the current is supplied from the power supply side terminal 6 to the fixed contact 5, the intermediate contact 7, the movable contact 2, the flexible conductor 10, and the relay. It flows to the load side terminal 16 through the conductor 15.

  The opening / closing mechanism 4 has a known configuration in which the holder 9 is driven to open and close via toggle links 18 a and 18 b provided between the holder 9 and the trip lever 17. The opening / closing mechanism 4 is opened / closed by a handle 19. When a large current such as a short-circuit current flows and the overcurrent tripping device 20 operates, the overcurrent tripping device 20 and the trip lever 17 are disengaged, and the movable contact is made by the energy stored in the opening / closing operation spring 21. The child 2 rotates clockwise through the holder 9 and is driven to open. At that time, as will be described later, the movable contact 2 and the intermediate contact 7 are separated by the contact electromagnetic repulsive force before the opening / closing mechanism 4 is operated.

  As shown in FIGS. 2 and 3, the contact device 1 provided in the circuit breaker includes a movable contact 2a on one end side (left side in FIG. 3) and is provided on the other end side (right side in FIG. 3). Further, the movable contact 2 is rotatably supported by the fulcrum shaft 3 as a fulcrum and driven to open and close by an opening / closing mechanism 4 (see FIG. 1). That is, the movable contact 2 performs a rotational movement so that the other end side is a fulcrum and the one end side draws an arc. Further, the contact device 1 includes a fixed contact 5 including a fixed contact 5a on one end side (right side in FIG. 3) and a power supply side terminal 6 integrally formed on the other end side (left side in FIG. 3). The fixed contact 5a and the movable contact 2a are arranged to face each other. The power supply side terminal 6 is not limited to the structure integrally formed with the fixed contact 5, and the power supply side terminal 6 may be formed on a member electrically connected to the fixed contact 5. The fixed contact 5 a may be provided in another part that is not one end side of the fixed contact 5. Further, one end side (the upper side in FIG. 3, ie, the movable contactor 2 side) includes a first intermediate contact 7a that contacts the movable contact 2a of the movable contactor 2, and the other end side (the lower side in FIG. An intermediate contact 7 including a second intermediate contact 7b in contact with the fixed contact 5a of the fixed contact 5 is provided on the contact 5 side). As shown in FIG. 3, the intermediate contact 7 is disposed between the movable contact 2 a of the movable contact 2 and the fixed contact 5 a of the fixed contact 5, and the side shape is formed in an I-shape. Further, as shown in FIG. 2, the intermediate contact 7 is in contact with the movable contact 2 at one first intermediate contact 7a, while the fixed contact 5 is connected at two second intermediate contacts 7b. In contact. As shown in FIG. 2, the fixed contact 5 includes two fixed contacts 5 a, and the fixed contact 5 is in contact with the intermediate contact 7 in the two fixed contacts 5 a. By providing two contact points between the intermediate contact 7 and the fixed contact 5, the contact is stabilized and temperature rise is prevented when current flows.

  The movable contact 2 is held by a holder 9 constituting a part of the opening / closing mechanism 4 and is driven to open / close by the opening / closing mechanism 4 via the holder 9. A fulcrum shaft 3 passing through the movable contact 2 is supported by a holder 9. A contact spring 11 made of a tension coil spring as a second member is stretched between the movable contact 2 and the holder 9. The movable contact 2 is urged in the counterclockwise direction of FIG. 3A, that is, the direction in which the movable contact 2a is in contact with the first intermediate contact 7a by the force that the contact spring 11 tries to contract. That is, the contact spring 11 biases the movable contact 2 so as to bias the intermediate contact 7 toward the fixed contact 5 via the first intermediate contact 7a. When a larger contact pressure is required for the contact pressure of the movable contact 2 to the intermediate contact 7 at the movable contact 2a, the movable contact 2a of the movable contact 2 is directly connected to the intermediate contact 7 by a contact spring. A contact spring can be arranged to press against the first intermediate contact 7a. For example, a contact spring is disposed above the movable contact 2a of the movable contact 2 in FIG. 3A along the direction from the first intermediate contact 7a of the intermediate contact 7 toward the second intermediate contact 7b. Can do.

  On the other hand, the intermediate contact 7 is held by a holding lever 14. A return spring 12 made up of a torsion spring as the first member is attached to the fulcrum shaft 8. The intermediate contact 7 is urged by the return spring 12 in the clockwise direction of FIG. 3A, that is, in the direction in which the second intermediate contact 7b comes into contact with the fixed contact 5a. That is, the return spring 12 biases the intermediate contact 7 toward the fixed contact 5. One end of the return spring 12 is hung on the holding lever 14, and the other end is hung on the case 13 (see FIG. 1) of the circuit breaker. The fulcrum shaft 8 of the holding lever 14 that holds the intermediate contact 7 is held by the case 13 as shown in FIG. A guide pin 7 c is provided so as to penetrate the intermediate contact 7. Both ends of the guide pin 7 c serving as a guide member are inserted into vertical guide grooves provided in the case 13. The guide pin 7c is formed so as to extend in a direction intersecting with the direction from the second intermediate contact 7b toward the first intermediate contact 7a (for example, a direction orthogonal). The intermediate contact 7 is supported by the guide pin 7c so as to be movable along the direction from the second intermediate contact 7b to the first intermediate contact 7a by being guided into the guide groove. Since the intermediate contact 7 of this embodiment is held by a holding lever 14 having a fulcrum shaft 8, the intermediate contact 7 can be moved on an arc orbit with the fulcrum shaft 8 as a rotation axis. That is, the direction from the second intermediate contact 7b toward the first intermediate contact 7a is not limited to the linear direction passing through the second intermediate contact 7b and the first intermediate contact 7a. The locus on the way from the contact point 7b to the first intermediate contact point 7a may be a curved line or a straight line.

  In a normal opening / closing operation, the movable contact 2 a and the intermediate contact 2 of the movable contact 2 are in a state where the second intermediate contact 7 b of the intermediate contact 7 is in contact with the fixed contact 5 a of the fixed contact 5 by the action of the return spring 12. 7 is performed by opening and closing with the first intermediate contact 7a. That is, when the opening / closing mechanism 4 is opened by operating the handle 19 from the closed state shown in FIG. 3A, the movable contact 2 and the holder 9 move in the clockwise direction of FIG. Does not move. Then, as shown in FIG. 3C, the second intermediate contact 7b is in contact with the fixed contact 5a, and the movable contact 2a and the first intermediate contact 7a are separated to be in an open state.

  Hereinafter, the breaking operation when an overcurrent flows through the circuit breaker will be described. In FIG. 3 (a), the current flows as shown by the arrows, but there is a contact electromagnetic repulsive force between the fixed contact 5a and the second intermediate contact 7b and between the movable contact 2a and the first intermediate contact 7a. is working. Therefore, when a large overcurrent such as a short circuit current flows and the contact electromagnetic repulsion force exceeds the contact force of the contact spring 11 and the return spring 12, the movable contact 2 and the intermediate contact 7 resist the contact spring 11 and the return spring 12. Then, it is driven instantaneously before the opening / closing mechanism 4 starts operating, and is opened as shown in FIG.

  As a result, an arc 22 generated between the fixed contact 5a and the second intermediate contact 7b and an arc 23 generated between the movable contact 2a and the first intermediate contact 7a are respectively directed toward the arc extinguishing device. It is stretched, current limiting is performed by increasing the arc voltage, and the current is interrupted. At this time, the contact spring 11 is stretched between the movable contact 2 and the holder 9, and the contact spring 11 is located at a position where the contact spring 11 shown in FIG. Most stretched. That is, when the movable contact 2 is driven further in the clockwise direction than the position shown in FIG. 3B by the contact electromagnetic repulsive force, the movable contact 2 is moved by the action of the force that the contact spring 11 tries to contract. It is driven in the direction and is in an inverted state. Therefore, the movable contact 2 is not restored to the closed position shown in FIG. Subsequently, when the holder 9 is driven by the opening / closing mechanism 4, the tip of the movable contactor 2 in the inverted state hits a stopper provided on the ceiling of the case 13 and is pushed back counterclockwise. Return as shown in 3 (c). As shown in FIG. 3C, since the movable contact 2 is held at the open position even after the contact electromagnetic repulsive force disappears, the current can be reliably interrupted. The intermediate contact 7 is returned to a state in which the intermediate contact 7 is in contact with the fixed contact 5 a of the fixed contact 5 by the return spring 12.

  As described above, in the circuit breaker according to the present invention, the movable contact 2 and the fixed contact 5 have the same configuration as that of the conventional one-point circuit breaker, and the intermediate contact 7 is added to add 2 A dotted circuit breaker can be configured. In other words, with a simple structure in which the conventional one-point circuit breaker is only partially modified, the breaking performance is improved compared to a one-point circuit breaker that makes arc generation easy by two places. A high two-point circuit breaker can be provided. Further, the circuit breaker of the present invention has the same dimension in the lateral direction as the one-point circuit breaker, and the height direction is increased by the dimension of the intermediate contact 7. Compared to a circuit breaker, it can be downsized and save space. In addition, as a current path, only the intermediate contact 7 is added from the one-point circuit breaker, and the current path is shorter than that of the conventional two-point circuit breaker. It is possible to reduce the material required for manufacturing the container, and to reduce the manufacturing cost.

  Further, the contact spring 11 as the second member biases the movable contact 2 toward the fixed contact 5 and also biases the intermediate contact 7 toward the fixed contact 5. The contact force between the second movable contact 2a and the first intermediate contact 7a of the intermediate contact 7 is equivalent to that of a conventional one-point circuit breaker. That is, the amount of work required when the movable contactor 2 is opened / closed by the opening / closing mechanism 4 is equivalent to that of a conventional one-point circuit breaker. Therefore, it is possible to provide a two-point circuit breaker having a higher breaking performance than the one-point circuit breaker while suppressing the load on the switching mechanism 4 to be equal to that of the one-point circuit breaker.

  In the above description, the intermediate contact 7 is drawn between the movable contact 2a and the fixed contact 5a so as to draw an arc having the fulcrum shaft 8 as the rotation axis while being guided by the guide pin 7c into the guide groove. However, the structure for guiding and supporting the intermediate contact 7 is not limited to the above. The intermediate contact 7 may be supported so as to be linearly movable between the movable contact 2a and the fixed contact 5a. For example, instead of the guide pin 7c and the holding lever 14, in order to allow the intermediate contact 7 to move on a straight line connecting the movable contact 2a and the fixed contact 5a, a cylindrical member fixed to the case 13 is provided, and the intermediate contact is provided. The child 7 may be configured to be movable in a straight path formed by the cylindrical member. If the return spring 12 or other elastic body is attached to the cylindrical member, it is possible to bias the intermediate contact 7 in the direction in which the second intermediate contact 7b comes into contact with the fixed contact 5a. Alternatively, a linear guide may be configured by fixing a rail to the case 13 and installing a slider on the intermediate contact 7.

  The embodiment disclosed this time is to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic diagram which shows the structure of the circuit breaker by one embodiment of this invention. It is a perspective view which shows the structure of a contactor apparatus. It is a schematic diagram which shows the interruption | blocking operation | movement of a contactor apparatus. It is side surface sectional drawing which shows an example of the conventional one-point circuit breaker. It is side surface sectional drawing which shows an example of the conventional two-point circuit breaker. It is side surface sectional drawing which shows the other example of the conventional two-point circuit breaker.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Contactor apparatus, 2 Movable contactor, 2a Movable contact point, 3 fulcrum shaft, 4 Opening and closing mechanism, 5 Fixed contactor, 5a Fixed contact point, 6 Power supply side terminal, 7 Intermediate contactor, 7a First intermediate contact, 7b 1st 2 intermediate contacts, 7c guide pin, 8 fulcrum shaft, 9 holder, 10 flexible conductor, 11 contact spring, 12 return spring, 13 case, 14 holding lever, 15 relay conductor, 16 load side terminal, 17 trip lever, 18a, 18b Toggle link, 19 Handle, 20 Overcurrent trip device, 21 Open / close operation spring, 22, 23 Arc, 102 Arc extinguishing device, 103 Fixed contact, 104 Fixed contact, 105 Movable contact, 106 Movable contact, 209 Movable contact block, 212 first current limiting contact block, 212a, 212b end, 215 first contact block, 217, 221 pin, 222 2nd current-limiting contact block, 222a, 222b end, 223 2nd contact block, 311, 312 fixed contact, 313 contact bridge, 320 rotating drive rod, 322, 323 tension spring, 324, 325 conductor, 326, 327 Termination, 328, 329 Fixed contact part, 331, 332 Movable contact part.

Claims (1)

A movable contact that includes a movable contact on one end side, is rotatably supported by a shaft provided on the other end side, and is opened and closed by an opening and closing mechanism;
In a circuit breaker comprising a fixed contact including a fixed contact,
An intermediate contact that includes a first intermediate contact that contacts the movable contact at one end and a second intermediate contact that contacts the fixed contact at the other end;
A first member that biases the intermediate contact toward the stationary contact;
A second member for urging the movable contact so as to urge the intermediate contact toward the fixed contact through the first intermediate contact;
The circuit breaker, wherein the intermediate contact is supported so as to be movable along a direction from the second intermediate contact toward the first intermediate contact.

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