JP6289677B2 - Circuit breaker - Google Patents

Description

  The present invention relates to a circuit breaker, and more particularly to the relative structure of its trip bar and trip bar spring.

  When an overcurrent flows in the circuit breaker, the trip mechanism will reliably trip without interfering with the tripping load of the trip device, and when the tripped breaker is turned on again. It is necessary to perform the reset operation without fail. Conventionally, as an example of the countermeasure, the trip bar is biased by one end of a trip bar spring (twist spring), and the latch is biased by the other end of the trip bar spring.

Japanese Patent No. 5304658

  In the conventional circuit breaker, when the trip circuit breaker is reset, the trip bar has a feature that the trip bar is returned from the trip position to the reset position only by the force of the trip bar spring. However, with the trip bar and trip bar spring structure of the above structure, only a substantially constant spring moment can be obtained regardless of the trip bar operating position, and the operating angle itself is small, so when shifting from the trip state to the reset state, However, there is a problem that it is difficult to obtain a large rotational moment for making the reset operation advantageous.

  The present invention has been made to solve the above-described problems, and can increase the trip bar return force at the time of resetting without increasing the operating load of the trip bar required at the time of tripping. And it aims at obtaining the structure of a trip bar spring.

A circuit breaker according to the present invention is a circuit breaker in which a trip bar is driven by an overcurrent trip device to perform a break operation, and the trip bar performs a reset operation by a biasing force of a trip bar spring.
The action point at which the urging force of the trip bar spring acts on the trip bar is:
From the on state to the completion of tripping, at the tip of the trip bar spring,
Between the trip completion and the trip position , the trip bar spring has a position closer to the root side than the tip.
By forming each, it does not increase the trip bar's operating load to the trip completion position by the overcurrent trip device in the entire trip bar operating range, and a large rotational moment is obtained in the trip bar after completion of tripping. It can be done.

  According to the present invention, the rotational moment acting on the trip bar by the trip bar spring during the trip bar operation is obtained in two stages, and the load at the time of tripping the trip bar until the tripping by the overcurrent tripping device is completed. The trip bar reset force at reset after completion of tripping can be increased without increasing the breakage, and the reset of the circuit breaker mainly due to the influence of melt, soot, etc. that occurs when the circuit breaker is short-circuited It becomes possible to prevent the impossibility.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1 of this invention, and is an external appearance perspective view which shows an example of the external appearance in the state which removed the cover of the circuit breaker. It is a figure which shows Embodiment 1 of this invention, and is a vertical side view which shows an example of the open circuit state (off state) of a circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1 of this invention, and is a side view of the principal part of the circuit breaker which shows an example of the closed circuit state (ON state) of a circuit breaker. It is a figure which shows Embodiment 1 of this invention, and is a side view of the principal part of the circuit breaker which shows an example of the open circuit state (off state) of a circuit breaker. It is a figure which shows Embodiment 1 of this invention, and is a side view of the principal part of the circuit breaker which shows an example of the trip state of a circuit breaker. It is a figure which shows Embodiment 1 of this invention, and is a side view of the principal part of the circuit breaker which shows an example of the reset state of a circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1 of this invention, and is a side view which shows an example of the principal part of this invention, and is a side view which expands and shows the part of the trip bar in a reset state, a latch, a trip bar spring, and a lever. . BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1 of this invention, It is a side view which shows an example of the principal part of this invention, (a) is the state of the principal part in the ON state (closed state) of a circuit breaker, () Is a diagram showing the state of the main part at the trip completion position of the circuit breaker, and (c) is a diagram showing the state of the main part in the trip state of the circuit breaker. It is a figure which shows Embodiment 2 of this invention, It is a side view which shows an example of the principal part of this invention, (a) is the state of the principal part in the ON state (closed state) of a circuit breaker, () Is a diagram showing the state of the main part at the trip completion position of the circuit breaker, and (c) is a diagram showing the state of the main part in the trip state of the circuit breaker. It is a figure which shows Embodiment 3 of this invention, It is a side view which shows an example of the principal part of this invention, (a) is the state of the principal part in the ON state (closed state) of a circuit breaker, () Is a diagram showing the state of the main part at the trip completion position of the circuit breaker, and (c) is a diagram showing the state of the main part in the trip state of the circuit breaker. It is a side view which shows an example of the principal part in the conventional circuit breaker, (a) is the state of the principal part in the ON state (closed circuit state) of the circuit breaker, (b) is the completion of tripping of the circuit breaker (C) is a figure which shows the state of the principal part in the trip state of a circuit breaker, respectively.

Embodiment 1 FIG.
Hereinafter, in showing Embodiment 1 of the present invention, a circuit breaker switching mechanism will be described with reference to the drawings. 1 is an external perspective view of a circuit breaker with a cover removed according to Embodiment 1 of the present invention, FIG. 2 is a sectional view showing an OFF state in FIG. 1, and FIGS. 3 is a partial side view, FIG. 3 shows a closed state (ON), FIG. 4 shows an open state (OFF), FIG. 5 shows a trip state, and FIG. 6 shows a reset state.

  As shown in FIGS. 1 and 2, the circuit breaker 101 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 20 corresponding to the number of poles are arranged at intervals, and an open / close mechanism 40 having a well-known toggle link mechanism is disposed above the circuit breaker unit 20. The cover 12 covers the circuit breaker unit 20 of each pole on the base 11 and the opening / closing mechanism 40, and the operation handle 41 of the opening / closing mechanism 40 protrudes from the handle window hole 12 a of the cover 12.

  The circuit breaker units 20 for each pole are configured in the same manner, and the crossbar 32 is arranged on the base 11 so as to be orthogonal to the circuit breaker unit 20 for each pole in common with the circuit breaker unit 20 for each pole. Is done. The cross bar 32 is rotated around its axis by the opening / closing mechanism 40, and each movable contact 23 in the circuit breaker unit 20 of each pole is attached. When the cross bar 32 rotates about its axis, the movable contacts 23 of the circuit breaker unit 20 of each pole are simultaneously rotated, and the movable contact 22 is fixed by the rotation of the movable contact 23. Contact and release the contact 21. The opening / closing mechanism 40 includes a known toggle link mechanism, and includes a known trip bar 33 that is driven by the tripping device 30.

  The circuit breaker unit 20 of each pole includes a power supply side terminal 24 provided on the base 11, a fixed contact 27 extending from the power supply side terminal 24 and having a fixed contact 21, and contacting and opening the fixed contact 21. The movable contact 22 to be separated, the movable contact 22 provided at one end and rotatably held by a cross bar 32, and the movable contact 23 connected to the movable contact 23 via a movable contact holder 26 A tripping device 30, a load side terminal 25 extending from the tripping device 30, and an arc extinguishing device 50 in which a plurality of grid plates surrounding the contacts 21, 22 and the stationary contact 27 are stacked. .

  The fixed contact 21 and the movable contact 22 constitute an open / close contact that opens and closes the electric circuit. If the movable contact 22 contacts the fixed contact 21, the electrical circuit between the terminals 24 and 25 is turned on. If the movable contact 22 is separated from the fixed contact 21, the electrical circuit between the terminals 24 and 25. Is turned off. At this time, the arc generated between the movable contact 22 and the fixed contact 21 is extinguished by the arc extinguishing device 50.

  In FIG. 3, a cross bar 32 formed of a synthetic resin material is rotatably supported by a base 11 formed of a synthetic resin material or a fixed frame 43 attached to the base 11. A movable contact 23 having a movable contact 22 at one end is pivotally supported inside the cross bar 32 so as to rotate in conjunction with the rotation of the cross bar 32. A fixed contact 27 having a fixed contact 21 that contacts and separates from the movable contact 22 is mounted on the base 11. One end 46 a of the lower link 46 is connected to the cross bar 32 by a cross bar pin 36, and the other end 46 b of the lower link 46 is connected to one end 45 a of the upper link 45 by a link pin 47. The other end 45 b of the upper link 45 is connected to a lever 44 engaged with the latch 34. An opening / closing spring 48 is stretched between the link pin 47 and the handle arm 42 interlocking with the handle 41 formed of a synthetic resin material. The toggle link mechanism is constituted by the lower link 46, the upper link 45, and the link pin 47. When the handle 41 is operated in the right direction on the paper surface, the line of action of the opening / closing spring 48 exceeds the dead point of the toggle link mechanism. As a result, the toggle link mechanism extends rapidly, and the circuit breaker 101 can be kept closed.

  From this state, when the handle 41 is operated to the left in FIG. 3, the action line of the opening / closing spring 48 exceeds the dead point of the toggle link mechanism, and the toggle link mechanism is bent. That is, the lower link 46 pulls up the crossbar pin 36, and the crossbar 32 rotates counterclockwise on the paper surface of FIG. 3, thereby lifting the movable contact 23. As shown in FIG. The contact 22 and the fixed contact 21 are separated, and the circuit breaker 101 is moved to an open circuit.

  Next, the trip operation of the circuit breaker 101 will be described with reference to FIG. When an overcurrent flows through the circuit breaker in the closed state, the trip device 30 (see FIG. 2) operates, and the trip bar 33 on the paper surface of the trip bar 33 rotatably supported by the fixed frame 43 via the trip bar pin 37 is operated. The lower end is pressed and the trip bar 33 is rotated counterclockwise on the paper surface of FIG. When the trip bar 33 rotates with the trip bar pin 37 as a fulcrum, the latch 34 is disengaged at the engaging portion 34b between the trip bar 33 and the latch 34 pivotally supported by the fulcrum 34a on the fixed frame 43. It rotates counterclockwise on the paper surface with the fulcrum 34a as a fulcrum. As the latch 34 rotates, the engagement of the lever 34 pivotally supported by the latch 34 and the fixed frame 43 at the fulcrum 44 a is disengaged at the engaging portion 34 c, and the lever 44 is moved on the paper surface by the force of the opening / closing spring 48. It rotates around the fulcrum 44a in the clockwise direction. At the same time, the upper link 45 pivotally supported by the lever 44 pulls up the cross bar 32 via the lower link 46, and the movable contact 22 and the fixed contact 21 are separated to complete the trip operation.

Next, the reset operation of the circuit breaker 101 will be described with reference to FIG. When the handle 41 is rotated leftward on the paper surface in the trip state (state of FIG. 5), the handle arm 42 rotates the lever 44 in conjunction with the circuit breaker. When the lever 44 is rotated and the engagement position at the engagement portion 34c (see FIG. 4) of the lever 44 and the latch 34 is exceeded, the latch 34 and the trip bar 33 are in the form of a torsion spring attached to the rotation shaft 34a of the latch 34. A rotational moment of the trip bar spring 35 (the center of this rotational moment is the fulcrum 34a of the latch 34, and the action points are 33a, 33b, 33c) is engaged by the engaging portion 34b (see FIG. 4). . By the engagement, the lever 44 is held by the latch 34 in a reset state (a state in which the lever 44 and the latch 34 are engaged as shown by 34c in FIG. 4), thereby completing the reset operation.
The state where the reset operation is completed is illustrated in an enlarged manner in FIG. The action point at which the urging force of the trip bar spring 35 acts on the trip bar 33 is the tip of the trip bar spring 35, the tip of the trip bar spring 35, and the support point of the trip bar spring 35 (the rotation of the trip bar spring 35). It is formed between the center and the fulcrum 34a).

  Hereinafter, an example of a main part of the present invention will be described in detail with reference to the case of FIG. FIG. 8 is a side view showing an example of the main part of the present invention, where (a) shows the state of the main part when the circuit breaker is on (closed state), and (b) is the trip of the circuit breaker. (C) is a figure which shows the state of the principal part in the trip state of a circuit breaker, respectively, in the state of the principal part in a completion position.

In the closed state of the circuit breaker (see FIG. 8A), the trip bar 33 is in contact with one end of the trip bar spring 35 at the first engagement portion 33a.
From this state, the circuit breaker is in contact with the first engaging portion 33a in the same way as described above until the trip completion position (see FIG. 8B) during the trip operation, so that the trip bar of the trip bar 33 during this time Since the rotational moment by the spring 35 is substantially constant, the load at the time of tripping of the trip bar 33 is not rapidly increased until the tripping by the tripping device is completed. Thereafter, after the completion of the tripping, the trip bar 33 and the trip bar spring 35 come into contact with a projection 33b provided separately from the first engagement portion 33a when the range reaches the trip position (see FIG. 8C). Therefore, the trip bar 33 and the trip bar spring 35 come into contact with each other on the base side of the trip bar spring 35, and the rotational moment due to the trip bar spring 35 increases rapidly. That is, in the reset operation in which the trip bar 33 moves (counterclockwise rotation on the paper surface) opposite to the trip operation (clockwise rotation on the paper surface), the return force of the trip bar 33 increases at the time of reset. In other words, it becomes possible to prevent the inability to reset due to the influence of the melt, soot, etc. that are generated mainly when the short circuit is interrupted. In other words, the wrinkles at the time of blocking adhere to the rotating shaft 37 portion of the trip bar 33, and this adhesion increases friction with respect to the rotation of the trip bar 33 at the rotating shaft 37 portion, thereby preventing the trip bar 33 from rotating. If the trip bar spring 35 has a small spring force, resetting may not be possible. However, according to the first embodiment, as described above, it becomes possible to prevent resetting from being impossible.

For example, in the conventional circuit breaker shown in FIG. 11, the trip bar 33 has a small operating angle, and the trip bar 33 and the trip bar spring 35 are always at the tip of the trip bar spring 35 and one trip bar 33 as shown in the figure. Since it is difficult to obtain a large rotational moment due to contact with the engaging portion 33a, and resetting may be impossible, according to the first embodiment, as described above, it is possible to prevent resetting impossible. Is possible.
Note that the center of the rotational moment acting on the trip bar 33 by the trip bar spring 35 (the fulcrum 34a of the latch 34) does not change, and the contact position (action point) between the trip bar 33 and the trip bar spring 35 changes (see FIG. 33a). By changing to 33b (in the case of the first embodiment) or 33c (in the case of the second and third embodiments described later), the rotational moment of the trip bar 33 increases.

Embodiment 2. FIG.
The second embodiment of the present invention will be described below based on the example of FIG. In order to obtain a rotational moment in two stages, one end of the trip bar spring 35 on the trip bar 33 side is bent from the bent portion 35a. As a result, the same effect as in the first embodiment can be obtained, and the trip bar 33 is in contact with the trip bar spring 35 and the first engagement portion 33a of the trip bar 33 until the trip by the trip device is completed. The return force of the trip bar 33 at the time of resetting can be increased without increasing the load at the time of removal and by changing the contact position to the second engaging portion 33c of the trip bar 33 after completion of the tripping, It becomes possible to prevent inability to reset mainly due to the influence of the melt, soot, etc. generated at the time of short circuit interruption.

Embodiment 3 FIG.
A third embodiment of the present invention will be described below based on the example of FIG.
The protrusion 33b of the trip bar 33 shown in the first embodiment and the trip bar spring 35 having one end on the trip bar 33 side shown in the second embodiment bent from the bent portion 35a are used in combination. This makes it possible to obtain a greater effect.

As is clear from the above description and the respective drawings, the first embodiment has the following technical features.
Feature 1: A handle arm pivotally supported on a fixed frame and operated by a handle, a toggle link having an upper link and a lower link, and an open / close spring stretched between the connecting portion and the handle arm A mechanism, a crossbar connected to the lower link by a crossbar pin and rotated by the operation of the toggle link mechanism; a movable contact at one end; In a circuit breaker switching mechanism having a movable contact that is interlocked with the rotation of the movable contact and a fixed contact that has a fixed contact that contacts and separates from the movable contact, a fixed frame is used for the trip operation by the trip device. Has a trip bar, a latch and a lever pivotally supported by each other, and the reset operation by the engagement of the three parts and the urging force of the trip bar spring provided on the latch rotating shaft In the circuit breaker having a trip mechanism for performing, the trip bar protrudes toward the rotation center side of the trip bar spring, and has a projection that engages with the trip bar spring at the trip position from the trip completion position. .
Feature 2: A handle arm pivotally supported by a fixed frame and operated by a handle, a toggle link having an upper link and a lower link, and an open / close spring stretched between the connecting portion and the handle arm A mechanism, a crossbar connected to the lower link by a crossbar pin and rotated by the operation of the toggle link mechanism; a movable contact at one end; In a circuit breaker switching mechanism having a movable contact that is interlocked with the rotation of the movable contact and a fixed contact that has a fixed contact that contacts and separates from the movable contact, a fixed frame is used for the trip operation by the trip device. Has a trip bar, a latch and a lever pivotally supported by each other, and the reset operation by the engagement of the three parts and the urging force of the trip bar spring provided on the latch rotating shaft In the circuit breaker having a trip mechanism portion performing, by bending the end of the trip bar spring of the tripping mechanism, thereby obtaining a rotational moment in two stages.

In addition, in each figure, the same code | symbol shows the same or an equivalent part.
In the present invention, each embodiment can be appropriately modified, omitted, or combined within the scope of the invention.

11 base, 12 cover, 21 fixed contact,
22 movable contacts, 23 movable contacts, 27 fixed contacts,
32 crossbars, 33 trip bars,
33a 1st engaging part (action point), 33b Protrusion (action point),
33c 2nd engaging part (action point), 34 latch,
34a Latch 34 fulcrum (rotating shaft) (center of rotational moment) (trip bar spring fulcrum),
34b engagement portion (engagement portion between trip bar 33 and latch 34),
34c engagement portion (engagement portion between lever 44 and latch 34),
35 Trip bar spring, 36 Cross bar pin,
37 Trip bar pin (fulcrum of trip bar 33),
41 handle, 42 handle arm, 43 fixed frame,
44 lever 44a fulcrum of lever 44,
45 upper link, 45a one end of upper link 45,
45b, the other end of the upper link 45, 46 the lower link,
46a, one end of the lower link 46, 46b the other end of the lower link 46,
47 Link pin, 48 Opening / closing spring, 101 Circuit breaker

Claims (3)

In the circuit breaker in which the trip bar is driven by the overcurrent trip device and shuts off, and the trip bar resets by the biasing force of the trip bar spring.
The action point at which the urging force of the trip bar spring acts on the trip bar is:
From the on state to the completion of tripping, at the tip of the trip bar spring,
Between the trip completion and the trip position , the trip bar spring has a position closer to the root side than the tip.
A circuit breaker characterized by being formed respectively . The circuit breaker according to claim 1, the point of application of the position of the base side than the tip, the circuit breaker characterized in that it is formed by the projection provided on the trip bar. The circuit breaker according to claim 1 or claim 2, the point of application of the position of the base side than the tip, a circuit breaker characterized in that it is formed by the bent portion provided on the trip bar spring vessel.

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