JPH03159021A - Switching gear of circuit breaker - Google Patents

Abstract

PURPOSE:To moderate impact load applied to a holder at the pole opening time of a circuit breaker by bringing a pin which connects a holder and a lower link of a toggle link into contact with a frame to stop the holder at the pole opening time of the circuit breaker. CONSTITUTION:A pin 18 which connects a holder 7 and a lower link 16 is projected right -and left-ward till it comes close an intermediate diaphragm 2 and both ends are brought into contact with a bottom plane of an installed plate 5c which projects out of a frame seat 3 under the illustrated trip condition. At the OFF time of a circuit breaker and the trip time, the pin 18 connecting the holder 7 and the lower link 16 comes into collision with the installed plate 5c of the frame 5 and thus a switching gear is stopped. In this way, impact load applied to the holder 7 becomes smaller as compared with the case that the holder 7 comes into collision directly with the frame 5 or a main body case 1.

Description

[Detailed description of the invention] [Industrial application field]

The second invention relates to an opening/closing mechanism for a small-sized circuit breaker such as a molded case circuit breaker, and more specifically relates to means for stopping the opening/closing mechanism during opening.

[Conventional technology]

This type of opening/closing mechanism has a latch that is fixed to the main body case and rotatably supported by a frame that has side plates on the left and right, and that holds a movable contact and a latch whose tip is locked and prevented from rotating when it is not tripped. a holder rotatably supported by the main body case via an opening/closing shaft; a toggle link consisting of an upper link connected to the latch and a lower link connected to the holder; and the upper link and the lower link. It is equipped with an opening/closing spring stretched between a pin connecting the link and a handle lever swingably supported by the frame, and is used to open/close the operating handle attached to the head of the handle lever or to prevent overcurrent. When the latch is released due to the operation of the disconnection device, the spring force of the opening/closing spring against the toggle link is caused to exceed the dead center, and the holder is rapidly rotated to perform ON/OFF and trip operations of the circuit breaker. I'm letting it go. In such an opening/closing mechanism, at the end of the opening operation (OFF operation and tripping operation), the holder or a portion connected thereto must collide with a stopper to hold the opening/closing mechanism in a stationary state. Conventionally, the following measures were taken for this purpose. (1) Make the holder collide with the pin that supports the latch on the frame. (2) Collision of the holder with a part of the main body case. (3) The movable contact held by the holder collides with the latch support pin.

[Problem to be solved by the invention]

However, in the structure of (1) and (2) above, in which the holder itself collides with the latch support pin or the main body case, the holder made of molded resin receives a large impact force, and the strength is affected by the shape, wall thickness, material, etc. of the holder. The problem is that it comes with many constraints. In addition, in the structure (3) above, the movable contact, which is a conductive part, comes into contact with the metal pin, so the conductive area expands to the metal frame and other metal parts supported by it. However, there is a problem in that a potential is applied to a portion that is not directly related to the conductive portion, thereby reducing insulation performance and adversely affecting interrupting performance. This invention solves these conventional problems, and aims to provide a circuit breaker opening/closing mechanism that reduces the impact load applied to the holder and avoids contact between the movable contact and the frame. That is.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a latch which is fixed to a main body case, is rotatably supported by a frame having side plates on the left and right, and whose tip is locked in a non-trip state to prevent rotation; a holder holding a movable contact and rotatably supported by the main body case via an opening/closing shaft; a toggle link comprising an upper link connected to the latch and a lower link connected to the holder; In the circuit breaker opening/closing mechanism, the circuit breaker opening/closing mechanism includes a pin connecting the upper link and the lower link, and an opening/closing spring stretched between a handle lever swingably supported by the frame. At extreme times, the pin connecting the holder and the lower link of the toggle link comes into contact with the frame to stop the holder. (Function) Since the holder collides with the frame via the connecting pin with the lower link, the impact is lessened compared to a direct collision.Also, since the connecting pin is separated from the movable contact, The conductive category area will not expand.

【Example】

The drawings show an embodiment of the invention, with FIG. 1 being a plan view and FIG. 2 being a sectional view taken along the line . In the figure, 1 is a main body case made of molded resin, 2
is an interphase wall that insulates the central pole portion shown in the figure from the left and right portions. Prismatic frame seats 3 and 4 are integrally formed on the opposing side surfaces of the phase separation wall 2, respectively.
．． A frame 5 formed by bending a steel plate is supported on the frame 4. The frame 5 consists of left and right side plates 5a along the side surfaces of the interphase wall 2, a bottom plate 5b that connects these to each other at one end, and a mounting plate 5c bent inward from the side plate 5a at the opposite end. The plate 50 is fastened to the frame seats 3 and 4 with screws 6. Reference numeral 7 denotes a bifurcated holder made of molded resin, which holds a movable contact 8 via a pin (not shown) inside the holder, and has an integrally molded opening/closing shaft 9 that connects the central pole part shown in the figure with the left and right type parts on both sides thereof. is rotatably supported by the main body case 1 by being fitted into the bearing notch 2a of the phase separation wall 2. Reference numeral 10 denotes a latch rotatably supported by the side plate 5a via a pin 11. In the trip state shown in the figure, the rear end is in contact with the pin 12 fixed to the side plate 5a and is in the position shown, but in the non-trip state. The tip 10a is locked to a latch receiver of a tripping mechanism (not shown), and is locked at a position rotated clockwise from the shown position. 13 is a toggle link consisting of an upper link I5 and a lower link 16 which are connected to each other by a pin I4, one end of the upper link I5 is connected to the latch 10 by a pin 17, and the lower link 16 is connected to the holder 7 by a pin 18. ing. center pin 14
protrudes left and right as shown in FIG. 1, and a pair of left and right opening/closing springs 19 are tensioned between the left and right ends and the head of a bifurcated handle lever (not shown) that is swingably supported by the frame 5. has been done. Further, as shown in FIG. 1, the pin 18 connecting the holder 7 and the lower link 16 protrudes left and right to a length close to the phase spacing wall 2, and both ends of the pin 18 protrude from the frame seat 3 in the illustrated tripped state. It comes into contact with the bottom surface of the plate 5c. In such a configuration, as is well known, when the opening/closing mechanism is reset to a state where the latch 10 is locked to the latch receiver and the operating handle (not shown) is operated to the left in the figure, the opening/closing spring 19 against the toggle link 13 is released. As the spring force exceeds the dead center, the toggle link 13 becomes straight, the holder 7 rotates counterclockwise, and the circuit breaker turns on.
do. In this state, if you turn the operation handle to the right in the diagram,
The spring force of the opening/closing spring 19 against the toggle link 13 exceeds the dead center in the opposite direction, and the toggle link 13 collapses, causing the holder 7 to rotate clockwise in FIG. 2 due to the spring force of the opening/closing spring 19, and the movable contact The child 8 is pulled up and the circuit breaker is turned off. At this time, at the end of the opening operation, the pin 18 collides with the mounting plate 5C, which is a part of the frame 5, and holds the opening/closing mechanism stationary at that position. In addition, when the fault current passes through the circuit breaker in the ON state,
When the overcurrent tripping device (not shown) trips and releases the latch 10, the latch 10 is activated by the opening/closing spring 19.
It rotates counterclockwise in Fig. 2 due to the spring force. As a result, the dead center crossing occurs and the circuit breaker is turned off. In that case as well, the pin 18 collides with the mounting plate 5C to keep the opening/closing mechanism stationary. At this time, the latch 10 comes into contact with the pin 11 and stops as described above, and the toggle link 13 stops with the protrusion 15a of the upper link 15 coming into contact with the pin 11 that supports the latch 10. As described above, according to the illustrated configuration, the circuit breaker is turned off.
When the holder 7 and the lower link 16 are tripped, the pin 18 that connects the holder 7 and the lower link 16 collides with the mounting plate 5C of the frame 5, stopping the opening/closing mechanism. In comparison, the impact load applied to the holder 7 is smaller. Moreover, since the pin 18 is spaced apart from the movable contact 8, even if it comes into contact with the frame 5, the conductive area will not be expanded thereby.

【Effect of the invention】

According to this invention, the impact load applied to the holder when the circuit breaker is opened is alleviated, and restrictions on its shape, wall thickness, material, etc. are reduced, making it easier to downsize the circuit breaker and reduce costs. . Further, at this time, the movable contact does not come into contact with metal parts, and there is no fear of deterioration of insulation performance.

[Brief explanation of the drawing]

The drawings show an embodiment of the invention, with FIG. 1 being a plan view and FIG. 2 being a sectional view taken along the line . I... Main body case, 5... Frame, 5a... Side plate, 7... Holder, 8... Movable contact, 9... Opening/closing shaft, 10... Latch, 13... Toggle link, 1
4...Upper link, 16...Lower link, 18...Pin, 19...Opening/closing spring. the law of nature

Claims (1)

[Claims] 1) A latch that is fixed to the main body case and rotatably supported by a frame having side plates on the left and right sides, and whose tip is locked and prevented from rotating in a non-trip state, and a latch that holds a movable contact and is attached to the main body case. a holder rotatably supported via an opening/closing shaft; a toggle link comprising an upper link connected to the latch and a lower link connected to the holder;
A circuit breaker opening/closing mechanism comprising an opening/closing spring stretched between a pin connecting the upper link and the lower link and a handle lever swingably supported by the frame, wherein An opening/closing mechanism for a circuit breaker, characterized in that, when opening, a pin connecting the holder and a lower link of a toggle link is brought into contact with a frame to stop the holder.