JP2009009840A - Circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve contact properties of contacts in which opening and closing are carried out at a pair of two contacts while equalizing opening and closing loads at these contacts. <P>SOLUTION: To the lower face side of a moving member 3, a moving member protective cover 6 is attached which is extended and stretched to a moving member connecting rod 5, and on the bottom face of the moving member protective cover 6, a protruding part 6a is formed which comes into contact with the recessed face of a holder 1 when movable contacts 2a, 2b are opened from fixed contacts 4a, 4b. An opening and closing mechanism 30 rotates a holder 1 excessively from a position where the movable contacts 2a, 2b come into contact with the fixed contacts 4a, 4b so that a gap is formed between the protruding part 6a and the recessed face of the holder 1 when the movable contacts 2a, 2b comes into contact with the fixed contacts 4a, 4b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a circuit breaker, and is particularly suitable for application to a method for improving the contactability and durability of a contact that is opened and closed by a pair of contact points.

  In the low piezoelectric path, a circuit breaker such as a circuit breaker for wiring or an earth leakage breaker is used in order to interrupt a short circuit current or a load current flowing through the load. Here, in a circuit breaker that is opened and closed by a pair of contact points, a method is proposed in which the movable contact can be rotated in a seesaw shape in the direction of the fixed contact in order to improve the contact stability reliability of the contact. (Patent Document 1).

FIG. 8 is a perspective view showing a schematic configuration of a contact portion of a circuit breaker that is opened and closed by a conventional two-contact pair.
In FIG. 8, the circuit breaker includes a first fixed contact 54 connected to the power supply terminal 53, a second fixed contact 56 connected to the connection conductor 55 connected to the trip device, and an opening / closing mechanism. A bridging contact 57 that is driven to open and close is provided. The bridging contact 57 is provided with movable contacts 58 and 59 at both ends so as to bridge the fixed contacts 54 and 56 when the contacts are closed. Yes. Then, at the tip of the movable contact arm 60 that is driven to open and close by the open / close mechanism, the movable contacts 58 and 59 at both ends of the bridge contactor 57 can be rotated in a seesaw shape in the direction of the fixed contacts 54 and 56. A central portion of the tangle contact 57 is supported.

  Here, the bridging contactor 57 is formed with contact arms 57c and 57d protruding from both ends of the base conductor 57a so as to face each other, and the movable contacts 58 and 59 are fixed to the tips of the contact arms 57c and 57d, respectively. At the same time, a connecting hole 57b is formed in the central portion of the base conductor 57a. The movable contact arm 60 is rotatably held by being inserted into the connecting hole 57b, and the stopper is functioned by applying a square bar of the movable contact arm 60 to the connecting hole 57b. .

Then, by allowing the movable contacts 58 and 59 to freely rotate until they hit the stopper, even when the thickness of the movable contacts 58 and 59 and the thickness of the fixed contacts 54 and 56 become different from each other due to wear or the like, It is possible to prevent one of the movable contacts 58 and 59 from being in contact with the fixed contacts 54 and 56 and causing poor conduction.
Japanese Patent Laid-Open No. 11-273536

However, in the method disclosed in Patent Document 1, since the movable contacts 58 and 59 can freely rotate until they hit the stopper, the bridging contactor 57 is in a state where the movable contacts 58 and 59 are separated from the fixed contacts 54 and 56. May rotate. For this reason, when the circuit breaker is turned on, the bridging contactor 57 is inclined to either the left or right side, and only one of the movable contacts 58 and 59 comes into contact with the fixed contacts 54 and 56 first, resulting in variations in closing timing. Since the switching load is concentrated only on one of the movable contacts 58 and 59, there is a problem that the risk of breakage or dropping of the movable contacts 58 and 59 increases.
In addition, since the tilted bridging contact 57 has a rotational force that returns to the horizontal, there is a problem that the corners of the fixed contacts 54 and 56 are easily lost.

FIG. 7 is a front view showing an inclined state of the movable contact when the conventional circuit breaker is turned on.
In FIG. 7, the circuit breaker is provided with a connection conductor 10a and a power supply terminal 10b. A fixed contact 4a is joined to the tip of the connection conductor 10a, and a fixed contact 4b is joined to the tip of the power supply terminal 10b. In addition, the circuit breaker is provided with a movable element 3 having a pair of arms arranged opposite to each other at both ends, and movable contacts 2a, 2b are opposed to the fixed contacts 4a, 4b at the ends of the pair of arms. To be joined. The mover 3 is supported by the holder 1 so as to be rotatable about the mover connecting rod 5 as a rotation axis.

In the configuration of FIG. 7, the movable element 3 may rotate around the axis of the movable element connecting rod 5 in a state where the movable contacts 2 a and 2 b are separated from the fixed contacts 4 a and 4 b. For this reason, when the circuit breaker is turned on, the movable element 3 is inclined to either the left or right side, and only one of the movable contacts 2a and 2b comes into contact with the fixed contacts 4a and 4b first. There was a case where the dropout was caused or the corners of the fixed contacts 4a, 4b were missing.
Therefore, an object of the present invention is to provide a circuit breaker capable of improving the contactability of these contacts while making the switching load of the contacts that are opened and closed by two contact pairs uniform. .

  In order to solve the above-described problem, according to the circuit breaker according to claim 1, a pair of fixed contacts, a mover including a pair of arms arranged to face each other, and an end of the arm, respectively. A pair of movable contacts fixed and openable and closable with each of the fixed contacts; a mover support for supporting the mover so as to be rotatable about an axis between the pair of arms; A holder that supports the movable element support so as to be rotatable in the direction of the fixed contact, an opening / closing mechanism that drives the movable element to open and close, and before the movable contact contacts the fixed contact, between the pair of arms. The mover is prevented from rotating around an axis, and the mover rotates around the axis between the pair of arms after at least one of the movable contacts contacts the fixed contact. Equipped with a stopper to allow And wherein the Rukoto.

  As a result, it is possible to prevent the mover from rotating about the axis between the pair of arms of the mover while the movable contact is away from the fixed contact. Even when the thicknesses of the fixed contacts are different from each other due to wear or the like, both the movable contacts can be reliably brought into contact with the fixed contacts. For this reason, even when opening and closing with two contact pairs, it is possible to prevent contact failure of one movable contact and improve contact stability reliability of the contact. , It is possible to prevent only one of the movable contacts from contacting the fixed contact first while the mover is tilted to the left or right, and the movable contact may be damaged or the corner of the fixed contact may be lost. Can be suppressed.

The circuit breaker according to claim 2 further comprises a mover protection cover attached to the mover, and when the movable contact is open from the fixed contact to the mover protection cover as the stopper. A convex portion that abuts against the holder surface is formed, and the open / close mechanism is configured so that a gap is formed between the convex portion and the holder surface when the movable contact contacts the fixed contact. The holder is over-rotated from a position in contact with the fixed contact.
This makes it possible to equalize the switching load of the contacts that are opened and closed with two contact pairs while suppressing the complexity of the structure of the circuit breaker, and improve the contactability of these contacts It is possible to improve the durability of the circuit breaker while suppressing the increase in size and cost of the circuit breaker.

In the circuit breaker according to claim 3, a rotation center for rotating the movable contact in the direction of the fixed contact is provided in the movable element support, and the contact pressure is applied to the movable contact. An urging means for urging the mover support is provided.
As a result, the movable contact can be pressed against the fixed contact when the movable contact comes into contact with the fixed contact, and the contact pressure can be maintained even when the mover can rotate about the axis between the pair of arms. Can be equalized.

Further, according to the circuit breaker according to claim 4, the urging means is arranged in the holder inserted into the left and right side surfaces of the mover support, and the leg is hooked on the pin by hooking a leg. And a contact pressure spring that applies contact pressure to the movable contact.
Accordingly, the force applied to the mover support can be made symmetrical while allowing the mover support to be stably held in the holder, and the mover is centered on the axis between the pair of arms. Even when the rotation is enabled, the contact pressure can be equalized.

  As described above, according to the present invention, even when opening / closing is performed by a pair of two contacts, it is possible to prevent contact failure of one movable contact and prevent contact failure, and contact stability reliability of the contact In addition, it is possible to prevent only one of the movable contacts from coming into contact with the fixed contact first while the mover is tilted to the left or right. It is possible to prevent the contact corners from being lost.

Hereinafter, a circuit breaker according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a schematic configuration of a circuit breaker according to an embodiment of the present invention, and FIG. 2 is an enlarged perspective view showing portions of a holder 1 and a mover 3 of the circuit breaker of FIG. FIG. 3 is an enlarged perspective view showing portions of the mover 3 and the mover protective cover 6 of the circuit breaker of FIG.
1 to 3, the circuit breaker is provided with a connection conductor 10a and a power supply terminal 10b fixed to the case 11, a fixed contact 4a at the tip of the connection conductor 10a, and a fixed contact at the tip of the power supply terminal 10b. 4b is joined.

Further, the circuit breaker is provided with a movable element 3 having a pair of arms 3a and 3b arranged opposite to each other at both ends, and movable contacts 2a and 2b are provided at the ends of the pair of arms 3a and 3b. The fixed contacts 4a and 4b are joined so as to face each other.
A mover connecting rod 5 is connected to the center of the mover 3 so as to protrude to the opposite side of the arms 3a and 3b, and the mover 3 is rotatably attached to the mover support 7 with the mover connecting rod 5 as a rotation axis. It is supported. The mover support 7 is incorporated in an insulator holder 1 that is rotatably supported via an opening / closing shaft.

Further, a mover protection cover 6 extending toward the mover connecting rod 5 is attached to the lower surface side of the mover 3, and the mover protection cover 6 is configured to cover the lower part of the mover connecting rod 5 from both sides. At the same time, a convex portion 6a is formed on the bottom surface of the mover protection cover 6 so as to contact the surface of the holder 1 when the movable contacts 2a, 2b are opened from the fixed contacts 4a, 4b.
Further, the circuit breaker is provided with an opening / closing mechanism 30 that opens and closes the movable element 3 between the fixed contacts 4a and 4b. The opening / closing mechanism 30 is movable with an opening / closing shaft integral with the holder 1 as a fulcrum. The child 3 can be driven to open and close.

  Further, the circuit breaker is provided with a tripping mechanism for tripping the lock of the opening / closing mechanism 30 and an overcurrent tripping device 27 for detecting the overcurrent and operating the tripping mechanism. Here, the overcurrent tripping device 27 incorporates a bimetal, a heater conductor, an armature, and an electromagnet, and based on the detection result of the overcurrent flowing through the load side terminal 12, a thermal or electromagnetic mechanical Can be generated. Then, the tripping mechanism transmits the mechanical deflection generated by the overcurrent tripping device 27 to the opening / closing mechanism 30 via the trip cross bar 25, thereby releasing the lock of the opening / closing mechanism 30. it can.

  The open / close handle 13 is connected to a handle lever 14, and the handle lever 14 is assembled so as to interlock with the open / close handle 13. Further, the circuit breaker is provided with a side plate 21 that supports the opening / closing mechanism 30, and the handle lever 14 is supported so as to be swingable about a lever shaft as a fulcrum, and the side plate 21 has a rotation center. ing. The handle lever 14 is connected to one end of an opening / closing spring 16 and the other end of the opening / closing spring 16 is connected to a toggle pin 18.

  Further, the circuit breaker is provided with a toggle mechanism including a first link 15 and a second link 17 connected to each other via a toggle pin 18, and an upper end of the first link 15 is connected to a latch 19, The two links 17 are connected to the holder 1. Further, a lower end hook portion of an opening / closing spring 16 constituted by a tension spring is hooked on the toggle pin 18, and an upper end hook portion of the opening / closing spring 16 is hooked on the upper end of the handle lever 14. Here, the toggle mechanism and the opening / closing spring 16 can constitute the opening / closing mechanism 30 of the circuit breaker. The opening / closing operation of the handle lever 14 reverses the direction of action on the opening / closing spring 16 to drive the holder 1 to open / close. By disengaging 19, the holder 1 can be opened and closed by reversing the action of the opening and closing spring 16 on the toggle mechanism.

  Further, the side plate 21 is provided with a link stopper 22 that stops the toggle mechanism at a predetermined position by contacting the toggle pin 18. In addition, the circuit breaker is provided with a latch 19 that is rotatably supported by a latch rotating shaft 20 as a fulcrum, and can be engaged with a latch receiver 23 and a latch receiver 23 that can be engaged with the latch 19. A trip cross bar 25 is provided.

Here, the latch 19 is configured to be rotatable about the latch rotation shaft 20, the latch receiver 23 is configured to be rotatable about the latch receiver rotation shaft 24, and the trip crossbar 25 is configured to be connected to the crossbar rotation shaft 26. It is comprised so that rotation is possible.
Then, the opening / closing operation of the opening / closing handle 13 in the left-right direction drives the handle lever 14 interlocked with the opening / closing handle 13 and the toggle mechanism operated by the opening / closing spring 16. The movable element 3 connected to the holder 1 rotates together with the holder 1 so that the movable contacts 2a and 2b come into contact with or separate from the fixed contacts 4a and 4b to perform a closing or opening operation. it can.

Here, in the opening / closing mechanism 30, the movable contacts 2a, 2b are fixed contacts 4a so that a gap is formed between the convex portion 6a and the concave surface of the holder 1 when the movable contacts 2a, 2b contact the fixed contacts 4a, 4b. The holder 1 can be rotated more than the position in contact with 4b.
And the convex part 6a of the needle | mover protective cover 6 is movable centering | focusing on the axis | shaft of the needle | mover connection rod 5 by contact | abutting on the surface of the holder 1 when the movable contacts 2a and 2b are open from the fixed contacts 4a and 4b. The protrusion 3a of the mover protective cover 6 is separated from the surface of the holder 1 when the mover 3 is prevented from rotating and the moveable contacts 2a, 2b come into contact with the fixed contacts 4a, 4b. It is possible to allow the mover 3 to rotate around the axis.

  This makes it possible to prevent the mover 3 from rotating about the axis of the mover connecting rod 5 while the movable contacts 2a, 2b are separated from the fixed contacts 4a, 4b. Even when the thicknesses 2a and 2b and the thicknesses of the fixed contacts 4a and 4b are different from each other due to wear and the like, both the movable contacts 2a and 2b can be reliably brought into contact with the fixed contacts 4a and 4b. . For this reason, even when opening and closing is performed by a pair of two contacts, it is possible to prevent contact failure of one of the movable contacts 2a and 2b and improve contact contact reliability. In addition, it is possible to prevent only one of the movable contacts 2a and 2b from contacting the fixed contact first while the movable element 3 is tilted to the left or right, and the movable contacts 2a and 2b are damaged. It is possible to prevent the corners of the fixed contacts 4a and 4b from being lost.

  FIG. 4A is a longitudinal sectional view showing a state of the movable element protective cover 6 when the movable contacts 2a, 2b and the fixed contacts 4a, 4b are opened, and FIG. 4B is a diagram showing the movable contacts 2a, 2b. FIG. 5A is a longitudinal sectional view showing a state of the mover protective cover 6 when the fixed contacts 4a and 4b are closed to each other, and FIG. 5A shows the movable contacts 2a and 2b and the fixed contacts 4a and 4b opened to each other. FIG. 5B is a cross-sectional view showing the state of the mover protection cover 6 when the movable contacts 2a, 2b and the fixed contacts 4a, 4b are closed to each other. FIG. 6 and FIG. 6 are front views showing an assembled state of the contact pressure spring 8 of FIG.

4 (a) and 5 (a), the convex portion 6a of the mover protection cover 6 is brought into contact with the surface of the holder 1 when the movable contacts 2a and 2b are opened from the fixed contacts 4a and 4b. The mover 3 is prevented from rotating about the axis of the child connecting rod 5.
4 (b) and FIG. 5 (b), the opening / closing mechanism 30 is provided between the convex portion 6a and the surface of the holder 1 when the movable contacts 2a, 2b come into contact with the fixed contacts 4a, 4b. The convex portion 6a of the mover protection cover 6 is separated from the surface of the holder 1 by rotating the holder 1 more than the position where the movable contacts 2a, 2b are in contact with the fixed contacts 4a, 4b so that a gap is left. And if the convex part 6a of the needle | mover protective cover 6 is spaced apart from the concave surface of the holder 1, the needle | mover protective cover 6 will be received by the wall surface of the holder 1, and it will move centering on the axis | shaft of the needle | mover connection rod 5. The child 3 can be allowed to rotate, and the timing of making both the movable contacts 2a and 2b can be made uniform.

Further, pins 9 a and 9 b are respectively inserted into the left and right side surfaces of the mover support 7, contact pressure springs 8 a and 8 b are disposed in the holder 1, and the contact pressure springs 8 a are provided at the pins 9 provided on the holder 1. 8b is supported. Then, the two legs 8a ′ and 8a ″ are pulled out from the contact pressure spring 8a, and the two legs 8b ′ and 8b ″ are pulled out from the contact pressure spring 8b, and the contact pressure springs 8a and 8b One leg 8a ', 8b' is hooked on the holder 1, and the other leg 8a ", 8b" of the contact pressure springs 8a, 8b is hooked on the pins 9a, 9b, respectively, to the contact pressure springs 8a, 8b. The movable contacts 2a and 2b are biased in the directions of the fixed contacts 4a and 4b, respectively, so that contact pressure is applied to the movable contacts 2a and 2b, respectively.
Accordingly, the force applied to the mover support 7 can be made symmetrical while allowing the mover support 7 to be stably held in the holder 1, and the mover 3 can be moved to the axis of the mover connecting rod 5. Even in the case where the rotation can be performed around the center, the contact pressure can be equalized.

It is a longitudinal section showing a schematic structure of a circuit breaker concerning one embodiment of the present invention. It is a perspective view which expands and shows the part of the holder 1 and the needle | mover 3 of the circuit breaker of FIG. It is a perspective view which expands and shows the part of the needle | mover 3 and the needle | mover protective cover 6 of the circuit breaker of FIG. FIG. 4A is a longitudinal sectional view showing a state of the movable element protective cover 6 when the movable contacts 2a, 2b and the fixed contacts 4a, 4b are opened, and FIG. 4B is a diagram showing the movable contacts 2a, 2b. It is a longitudinal cross-sectional view which shows the state of the needle | mover protective cover 6 when the stationary contacts 4a and 4b are mutually closed. FIG. 5A is a cross-sectional view showing the state of the movable element protective cover 6 when the movable contacts 2a and 2b and the fixed contacts 4a and 4b are open, and FIG. 5B is the movable contacts 2a and 2b. It is a cross-sectional view showing a state of the mover protection cover 6 when the stationary contacts 4a and 4b are closed to each other. FIG. 6 is a front view showing an assembled state of the contact pressure spring 8 of FIG. 5. It is a front view which shows the inclination state of the movable contact at the time of throwing in the conventional circuit breaker. It is a perspective view which shows schematic structure of the contact part of the circuit breaker which is opened and closed by the conventional 2 contact pair.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Holder 2a, 2b Movable contact 3 Movable element 3a, 3b Arm 4a, 4b Fixed contact 5 Movable element connecting rod 6 Movable element protection cover 6a Convex part 7 Movable element support 8 Contact pressure spring 8a, 8a ', 8b, 8b' leg 9, 9a, 9b Pin 10a Connection conductor 10b Power supply terminal 11 Case 12 Load side terminal 13 Open / close handle 14 Handle lever 15 Open / close spring 16 First link 17 Second link 18 Toggle pin 19 Latch 20 Latching shaft 21 Side plate 22 Link stopper 23 Latch receiver 24 Latch receiver rotating shaft 25 Trip crossbar 26 Crossbar rotating shaft 27 Overcurrent drawing device 30 Opening / closing mechanism

Claims (4)

A pair of fixed contacts;
A mover comprising a pair of arms arranged opposite to each other;
A pair of movable contacts that are respectively fixed to ends of the arms and that can be opened and closed with the fixed contacts;
A mover support for supporting the mover so as to be rotatable about an axis between the pair of arms;
A holder for supporting the movable element support so that the movable contact is rotatable in the direction of the fixed contact;
An opening and closing mechanism for opening and closing the mover;
Before the movable contact contacts the fixed contact, the movable element is prevented from rotating about the axis between the pair of arms, and at least one of the movable contacts contacts the fixed contact. A circuit breaker comprising: a stopper that allows the mover to rotate later about an axis between the pair of arms. A mover protective cover mounted on the mover;
Forming a convex portion that contacts the holder surface when the movable contact is open from the fixed contact on the mover protection cover as the stopper;
The opening / closing mechanism passes the holder beyond a position where the movable contact contacts the fixed contact so that a gap is formed between the convex portion and the holder surface when the movable contact contacts the fixed contact. The circuit breaker according to claim 1, wherein the circuit breaker is rotated.   A rotation center for rotating the movable contact in the direction of the fixed contact is provided in the movable element support, and biasing means for urging the movable element support is provided so that contact pressure is applied to the movable contact. The circuit breaker according to claim 1 or 2, characterized by the above. The biasing means is
Pins inserted on the left and right sides of the mover support;
4. The circuit breaker according to claim 3, further comprising a contact pressure spring that is disposed in the holder and applies a contact pressure to the movable contact by hooking a leg to the pin.

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