JP2012186065A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit breaker in which the reliability of opening/closing operation by an opening/closing mechanism can be improved.SOLUTION: A circuit breaker comprises: a lower link 46 which drives a cross bar 30; a lever 44 which rotates while being pivotally supported by a bearing part of a frame 43 during tripping; an upper link 45 which is pivotally supported by the lever 44 and coupled to the lower link 46 via a spring pin 47, and which constitutes a toggle link together with the lower link 46; a main spring 48 which is coupled at its driven side to the spring pin 47; a handle arm 42 which is coupled to the drive side of the main spring 48 and is rotatably supported by the frame 43 fixed to a housing; and a latch 34 on which the lever 44 slides upon a reset, and which locks the lever 44. Grooves 34a1 and 34a2 are provided on a sliding surface 34b of the latch 34 on which the lever 44 slides.

Description

  The present invention relates to a circuit breaker such as a circuit breaker for wiring or an earth leakage breaker, and more particularly to an improvement in operation reliability in an opening / closing mechanism.

In general circuit breakers, when the contact is closed (hereinafter referred to as ON state), overload current or short-circuit current flows to the circuit breaker, or when a leakage current is detected, a trip operation is performed to open the switching contact. The current is cut off and a trip state occurs. In order to perform the shut-off operation again from this trip state, it is necessary to perform a reset operation for engaging the lever with the latch that constitutes the opening / closing mechanism. In this reset operation, the lever is always in contact with the latch in order to stably engage the latch and the lever (see, for example, Patent Document 1).
In addition, in order to prevent the melt generated in the arc extinguishing chamber from adhering to the trip bar and the return spring due to the arc generated at the time of interruption, it is known to have a metal protective cover for shielding the metal melt. (For example, refer to Patent Document 2).

Japanese Patent Laying-Open No. 2009-245731 (FIG. 4) JP 2006-228492 A

As described above, in the conventional circuit breaker, if the obstruction obstructing the operation of the opening / closing mechanism such as melt or dust at the time of breaking is attached to the lever sliding surface of the latch, The obstruction is collected and the obstruction is caught between the lever and the latch. Thereby, at the time of trip operation, the necessary load for releasing the engagement between the latch and the lever becomes heavy, which may cause inability to trip. Further, at the time of the reset operation, the reset completion position of the handle becomes unstable and the reset operation cannot be performed, which may cause the contact opening / closing failure.
Further, in order to realize a stable reset operation, it is necessary to increase the engagement margin between the latch and the lever, and the sliding area between the latch and the lever is increased. However, if this sliding area is increased, there also arises a problem that more obstacles attached to the latch are collected during the reset operation.
In addition, the method of adding a protective cover as a separate part satisfies the issues such as reduction of part cost and assembly cost and securing space for internal parts as circuit breakers are being reduced in cost and size. It was difficult to do.

  The present invention has been made to solve the above-described problems, and provides a circuit breaker that can improve the reliability of an opening / closing operation in an opening / closing mechanism.

  A circuit breaker according to the present invention includes a movable contact having a movable contact, a fixed contact that contacts and separates from the movable contact, a cross bar that holds the movable contact and is rotatably supported, and drives the cross bar. A lower link that rotates, a lever that is pivotally supported by a bearing portion of a frame fixed to the casing of the circuit breaker during a trip, and a pivot that is pivotally supported by the lever and coupled to the lower link via a spring pin An upper link that forms a toggle link with the lower link, a main spring coupled to the driven side of the spring pin, a handle arm coupled to the drive side of the main spring, and pivotally supported by the frame, and a reset The lever sometimes slides and has a latch for locking the lever, and the latch has a recess on a sliding surface on which the lever slides.

  According to the present invention, since the recess is provided on the sliding surface of the latch, the operation obstruction collected by the lever at the time of the reset operation of the opening / closing mechanism is discharged to the recess, and the operation reliability in the opening / closing mechanism is improved. .

It is a perspective view which shows the trip state of the circuit breaker in Embodiment 1 of this invention. It is side surface sectional drawing which shows the trip state of the circuit breaker in Embodiment 1 of this invention. It is side surface sectional drawing which shows the OFF state of the circuit breaker in Embodiment 1 of this invention. It is side surface sectional drawing which shows the ON state of the circuit breaker in Embodiment 1 of this invention. It is a principal part perspective view which extracts and shows the opening-closing mechanism part, movable contact, and crossbar from the circuit breaker in Embodiment 1 of this invention. It is a perspective view which shows the latch of the circuit breaker in Embodiment 1 of this invention. It is a side view which shows the latch of the circuit breaker in Embodiment 1 of this invention. It is explanatory drawing explaining the latch and lever reset operation | movement of the circuit breaker in Embodiment 1 of this invention. It is a perspective view which shows the latch in Embodiment 2 of this invention. It is a perspective view which shows another Example of the latch in Embodiment 2 of this invention.

Embodiment 1 FIG.
1 is a perspective view showing a trip state of a circuit breaker according to Embodiment 1 of the present invention, FIG. 2 is a side sectional view showing a trip state, FIG. 3 is a side sectional view showing an off state, and FIG. 4 is an on state. FIG. 5 is a perspective view of the main part extracted from the opening / closing mechanism, the movable contactor, and the crossbar, FIG. 6 is a perspective view of the latch, and FIG. 7 is a side view of the latch. 8 is an explanatory diagram for explaining the reset operation of the latch and the lever.

  In FIG. 1, a circuit breaker 100 is configured by using a housing 10 including a base 11 and a cover 12 made of an insulating material. On the base 11, circuit breaker units 20A, 20B, and 20C for each of the three phases are arranged in parallel with each other, and an opening / closing mechanism unit 40 is arranged above the center circuit breaker unit 20B. The base 11 has a pair of outer walls 11A and 11B and a pair of partition walls 11C and 11D. A circuit breaker unit 20A is disposed between the outer wall 11A and the partition wall 11C, a circuit breaker unit 20B is disposed between the partition walls 11C and 11D, and a circuit breaker unit is disposed between the partition wall 11D and the outer wall 11B. 20C is arranged. The cover 12 covers the circuit breaker units 20A, 20B, and 20C of each phase on the base 11 and the opening / closing mechanism 40, and the operation handle 41 of the opening / closing mechanism 40 protrudes from the cover 12. In FIG. 1, the cover 12 cuts out portions covering the circuit breaker units 20 </ b> A and 20 </ b> B, and illustrates the inside thereof.

  The circuit interruption units 20A, 20B, and 20C for each phase are configured in the same manner, and specific configurations thereof are shown in FIGS. 2, 3, and 4. FIG. 2, 3, and 4 show the central circuit breaking unit 20 </ b> B, the other circuit breaking units 20 </ b> A and 20 </ b> C are configured in the same manner.

  The circuit breaker units 20A, 20B, and 20C for each phase include a power supply side terminal 24 provided on the base 11, a fixed contact 21 extended from the power supply side terminal 24, and a movable contact 22 that contacts and separates from the fixed contact 21. The movable contact 22 is provided at one end and is rotatably held by the crossbar 30; an overcurrent trip device 33 connected to the movable contact 23; and an overcurrent trip It has a load-side terminal 25 connected to the device 33 and provided on the base 11. When the movable contact 22 comes into contact with the fixed contact 21, the electric circuit between the terminals 24 and 25 is turned on, and when the movable contact 22 is separated from the fixed contact 21, the electric circuit between the terminals 24 and 25 is turned off.

  As shown in FIGS. 2, 3, and 4, the cross bar 30 is disposed at the bottom of the base 11 and extends so as to be orthogonal to the paper surface of FIGS. 2, 3, and 4. The crossbar 30 is rotated around its axis by the opening / closing mechanism 40, and the movable contacts 23 in the circuit breaker units 20A, 20B, and 20C for each phase are attached. When the cross bar 30 is rotated about its axis, the movable contacts 23 of each phase are simultaneously rotated, and the movable contact 22 is brought into contact with and separated from the fixed contact 21 by the rotation of the movable contact 23. To do.

  As shown in FIG. 5 in addition to FIGS. 2, 3, and 4, the opening / closing mechanism 40 is fixed to the base 11, and is formed with a frame 43 formed by a pair of opposed frame plates. A substantially U-shaped handle arm 42 (not shown in FIG. 5; shown in FIGS. 2, 3 and 4), which is pivotally supported by a dynamic axis P, and is fixed to the handle arm 42. The unit is unitized by a manually operated operation handle 41 (not shown in FIG. 5; shown in FIGS. 2, 3 and 4). The inside is latched by the latch 34 of the overcurrent tripping device 33 and is pivotally supported on the frame bearing portion 43a of the frame 43 by the rotating shaft 44a. The lever 44 is pivotally supported by the link support shaft Q. And a lower link 46 (not shown in FIG. 5; not shown in FIG. 5, but shown in FIGS. 2, 3 and 4) which is engaged with the upper link 45 via a spring pin 47. ), And a pair of main springs 48 stretched around the driven pin 48b and the drive side 48a on the handle arm 42, respectively.

  2, 3, and 4, the upper link 45 is rotatably supported at the upper end thereof by the link support shaft Q of the lever 44, and the lower link 46 has a lower end at the crossbar. 30 is rotatably connected. The operation handle 41 protrudes upward from the cover 12 and is rotated about the rotation axis P by manual operation. By the rotation of the operation handle 41, the handle arm 42 is also rotated around the rotation center point P together with the operation handle 41. The handle arm 42 is in the intermediate position in the trip state shown in FIG. 2, is in the left inclined position in the off state shown in FIG. 3, and is in the right inclined position in the on state shown in FIG.

  As shown in FIGS. 6 and 7, the latch 34 is formed of a single metal plate and is disposed on the inner surface side of each side plate of the handle arm 42. A first groove 34a1 and a second groove 34a2 are formed on the sliding surface 34b of the latch 34 on which the tip 44b of the lever 44 slides in order to remove obstructions such as melt and dust. When the tip 44b (illustrated in FIG. 8) of the lever 44 slides on the sliding surface 34b, the lever 44 fits into the first and second grooves 34a1 and 34a2, so that smooth sliding is not hindered. The first and second grooves 34 a 1 and 34 a 2 are alternately provided in a direction perpendicular to the sliding direction of the lever 44. In other words, the sliding surface 34b has at least one groove when the sliding surface 34b is viewed in the sliding direction in which the lever 44 slides, and the sliding surface 34b in a direction perpendicular to the sliding direction from the groove. The first contact portion 34a11 and the second contact portion 34a21 are in contact with each other when the latch 34 slides. The “recesses” described in the claims are the first and second grooves 34a1 and 34a2.

Next, on, off and trip operations of the circuit breaker 100 will be described.
As shown in FIG. 3, in the off state, the movable contact 22 is separated from the fixed contact 21, and the fixed contact 21 and the movable contact 22 are in the separated state. In the off state, the handle arm 42 is in the left inclined position, and the lower link 46 is in the sideways state. When the operation handle 41 is operated clockwise in the off state shown in FIG. 3, the handle arm 42 together with the operation handle 41 rotates clockwise around the rotation center point P, and the handle The arm 42 rotates to the right inclined position shown in FIG. By the rotation of the handle arm 42, the drive side 48 a of the main spring 48 moves in the clockwise direction around the rotation center point P of the handle arm 42. The movement of the drive side 48a of the main spring 48 changes the load direction of the main spring 48, and the spring pin 47 moves to the right from the position shown in FIG. The movement of the spring pin 47 brings the lower link 46 into an upright state, as shown in FIG. Touch and turn on.

  In the on state shown in FIG. 4, when the operation handle 41 is operated in the counterclockwise direction, the handle arm 42 rotates together with the operation handle 41 in the counterclockwise direction around the rotation center point P. The handle arm 42 rotates to the left inclined position shown in FIG. By the rotation of the handle arm 42, the drive side 48 a of the main spring 48 moves counterclockwise about the rotation center point P of the handle arm 42. The movement of the drive side 48a of the main spring 48 changes the load direction of the main spring 48, and the spring pin 47 moves to the left from the position shown in FIG. By the movement of the spring pin 47, as shown in FIG. 3, the lower link 46 returns to the horizontal state, the cross bar 30 rotates counterclockwise, and the movable contact 22 on the movable contact 23 is fixed. It is separated from the contact 21 and is turned off.

  In the ON state shown in FIG. 4, when the overcurrent tripping device 33 operates and the overcurrent tripping device 33 pushes and rotates the trip bar 35, the latch 34 is unlocked by the trip bar 35. As a result, the latch 34 is free to rotate, and the latch 34 and the lever 44 are disengaged. Since the lever 44 is always urged clockwise by the main spring 48, the lever 44 is rotated clockwise when the engagement with the latch 34 is released. By the rotation of the lever 44, the handle arm 42 is rotated from the right inclined position shown in FIG. 4 to the intermediate position shown in FIG. Due to the rotation of the handle arm 42, the drive side 48 a of the main spring 48 moves relatively to the right side of the spring pin 47, and an upward force starts to act on the spring pin 47. Due to the upward movement of the spring pin 47, the cross bar 30 is lifted upward, and the lower link 46 is in an intermediate standing state shown in FIG. 2, and the movable contact 22 of the movable contact 23 is separated from the fixed contact 21. The trip state shown in FIG.

Next, the reset operation of the circuit breaker 100 will be described.
In the trip state shown in FIGS. 2 and 8A, when the operation handle 41 is operated in the counterclockwise direction, the handle arm 42 together with the operation handle 41 rotates counterclockwise about the rotation center point P. The handle arm 42 rotates to the left inclined position in the off state shown in FIGS. 3 and 8B. By the rotation of the handle arm 42, the drive side 48 a of the main spring 48 moves counterclockwise about the rotation center point P of the handle arm 42.

  As shown in FIG. 8, as the drive side 48a of the main spring 48 moves, the tip 44b of the lever 44 slides on the sliding surface 34b of the latch 34 in the direction of arrow A (shown in FIG. 8A). On the other hand, it rotates counterclockwise around the rotation shaft 44 a against the urging force F of the main spring 48 and is locked by the locking portion 34 c of the latch 34. When the front end portion 44b of the lever 44 slides on the sliding surface 34b of the latch 34, the front end portion 44b collects an obstacle such as a melt or dust, and the front end portion 44b is provided in the latch 34. Inhibitors are discharged into the first groove 34a1 when passing through the groove 34a1.

  However, since the obstacle that has passed through the first contact portion 34a11 is not discharged into the first groove 34a1, the tip portion 44b is subsequently discharged into the second groove 34a2 when passing through the second groove 34a2. .

  According to the present embodiment, since the first and second grooves 34a1 and 34a2 are provided on the sliding surface 34b of the latch 34 on which the lever 44 slides, melts and dust adhering to the sliding surface 34b. The obstruction is discharged to the first and second grooves 34a1 and 34a2 when the lever 44 slides in the reset operation, and the operation reliability in the opening / closing mechanism 40 is improved.

  Further, since the first and second contact portions 34a11, 34a21 are provided on the sliding surface 34b of the latch 34, the lever 44 is also used when the tip end portion 44b of the lever 44 passes through the first and second grooves 34a1, 34a2. The sliding of 44 becomes smooth, and the reset operation can be stabilized.

  Further, since the latch 34 has the first and second grooves 34a1 and 34a2, the sliding area between the latch 34 and the lever 44 can be increased, and the engagement margin between the latch 34 and the lever 44 can be increased. The reset operation can be stabilized.

In the present embodiment, the first and second grooves 34a1 and 34a2 that are the recesses are hole grooves, but may be recesses instead of holes.
Further, the embodiment of the one-point cut type circuit breaker having the movable contact 22 at one end of the movable contact 23 has been described, but the two-point cut type circuit breaker having the movable contact at both ends of the movable contact 23 is described. Needless to say, the opening / closing mechanism in this embodiment can be applied, and the same effects as in the present embodiment can be obtained.

Embodiment 2. FIG.
FIG. 9 is a perspective view showing a latch 341 according to Embodiment 2 of the present invention, and FIG. 10 is a perspective view showing another embodiment of the latch 341. The latch 341 is provided with a plurality of first holes 341a1 instead of the first grooves 34a1 provided in the latch 34 in the first embodiment, and a plurality of second holes 341a2 is provided instead of the second grooves 34a2. It is a thing. The plurality of first holes 341a1 and the plurality of second holes 341a2 are alternately arranged.

  The latch 341 has a plurality of first contact portions 341a11 between the plurality of first holes 341a1 when the sliding surface 341b is viewed in a direction perpendicular to the sliding direction of the lever 44. . Further, a plurality of second contact portions 341a21 are provided between the plurality of second holes 341a2 when the sliding surface 341b is viewed in a direction perpendicular to the sliding direction of the lever 44.

  Since the plurality of first holes 341a1 and the plurality of second holes 341a2 are alternately arranged, when the lever 44 slides on the sliding surface 341b of the latch 341 during the reset operation, first, the obstacle is It is discharged into the first hole 341a1. And the obstruction which was not discharged | emitted by the 1st hole 341a1 through the 1st contact part 341a11 is discharged | emitted by the 2nd hole 341a2 after that. Other configurations are the same as those of the first embodiment, and thus description thereof is omitted.

    According to the present embodiment, since the first and second holes 341a1 and 341a2 are provided on the sliding surface 341b of the latch 341 on which the lever 44 slides, the melt and dust adhered to the sliding surface 34b. The obstruction is discharged to the first and second holes 341a1 and 341a2 when the lever 44 slides in the reset operation, and the operation reliability in the opening / closing mechanism 40 is improved.

  Further, since the first and second contact portions 341a11 and 341a21 are provided on the sliding surface 341b of the latch 341, also when the tip end portion 44b of the lever 44 passes through the first and second holes 341a1 and 341a2. The slide of the lever 44 becomes smooth, and the reset operation can be stabilized.

  Further, since the first and second contact portions 341a11, 341a21 are provided on the entire sliding surface 341b, the sliding of the lever 44 becomes smoother and the reset operation is stabilized.

  In addition, since the latch 341 has the first and second holes 341a1 and 341a2, the sliding area of the latch 341 and the lever 44 can be expanded, and the engagement margin between the latch 341 and the lever 44 can be increased. In addition, the reset operation can be stabilized.

  In the present embodiment, the case where a plurality of first holes 341a1 and a plurality of second holes 341a2 are used as the recesses in the claims is shown. However, as shown in FIG. 10, the plurality of holes 341a1, 341a2 Instead, a crescent-shaped groove 342a may be used. Also in the latch 342 of this embodiment, when the sliding surface 342b is viewed in a direction perpendicular to the sliding direction of the lever 44 from a crescent-shaped groove 342a provided in the sliding surface 342b, a plurality of contact portions 342a1.

  Moreover, although the example of the one-point cut type circuit breaker having a movable contact at one end of the movable contact has been described, the present embodiment is applied to a two-point cut type circuit breaker having movable contacts at both ends of the movable contact. Needless to say, the opening / closing mechanism in the embodiment can be applied, and the same effects as in the present embodiment can be obtained.

  In the above description, the circuit breaker has been described. However, it is a matter of course that this type of switch can be used in general, and even if minor changes are made, it does not depart from the scope of the invention.

21 fixed contact, 22 movable contact, 23 movable contact, 30 crossbar,
33 trip device, 34 latch, 34a1, first groove, 34a2 second groove,
34a11 first contact portion, 34a21 second contact portion,
42 handle arm, 43 frame, 44 lever,
45 upper link, 46 lower link,
47 Spring pin, 48 Main spring, 100 Circuit breaker.

Claims (6)

A movable contact having a movable contact, a fixed contact contacting and moving away from the movable contact, a cross bar holding the movable contact and pivotally supported freely, a lower link driving the cross bar, and a trip A lever which is pivotally supported by a bearing portion of a frame fixed to the casing of the circuit breaker, and is pivotally supported by the lever and coupled to the lower link via a spring pin. Together with an upper link constituting a toggle link, a main spring coupled to the driven side of the spring pin, a handle arm coupled to the drive side of the main spring and pivotally supported by the frame, and at the time of resetting A latch that slides and locks the lever;
The circuit breaker according to claim 1, wherein the latch has a recess on a sliding surface on which the lever slides. The latch has at least one concave portion when the sliding surface is viewed in the sliding direction in which the lever slides, and the sliding surface is viewed from the concave portion in a direction perpendicular to the sliding direction. The circuit breaker according to claim 1, further comprising a contact portion with which the lever contacts. The circuit breaker according to claim 1, wherein the recess is a hole. The circuit breaker according to claim 3, wherein the recess is a slot. The circuit breaker according to claim 4, wherein the slot has a plurality of slots arranged alternately. The circuit breaker according to claim 3, wherein the recess is a plurality of round holes.

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