JPH089886Y2 - Circuit breaker switching mechanism - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to an opening / closing mechanism for a small circuit breaker such as a circuit breaker for wiring.

[Prior art]

In a small circuit breaker opening / closing mechanism such as a circuit breaker, a toggle link is normally provided between a latch held by the trip mechanism and a movable contact holder that holds the movable contact. The movable contact is opened and closed by reversing the toggle link. The flip of the toggle link is done by opening and closing the spring which is stretched between the central pin connecting the upper link of the toggle link connected to the latch and the lower link of the toggle link connected to the movable contact holder and the operating handle lever. The spring force is exerted by crossing the dead center of the toggle link by turning the operating handle on and off.

[Problems to be solved by the device]

In the opening / closing mechanism of such a circuit breaker, conventionally, the upper link and the lower link of the toggle link are connected by inserting a center pin into a through hole formed at each connecting end of each link, and connecting the center pin to each other. One end of the opening / closing spring was hooked on the pin. Therefore, when assembling the opening / closing mechanism of the circuit breaker, first, the movable contactor part, in which the lower link of the toggle link is attached to the movable contactor holder in advance, is installed in the case, and then the opening / closing including the upper link of the toggle link is performed. The mechanism part was incorporated in the case, and then the center pin was inserted into the upper link and the lower link of the toggle link to connect them, and finally the opening and closing spring was stretched between the center pin and the operation handle lever ( (See JP-A-57-98945). However, in such a conventional structure, labor and skill are required to carry out the work of stretching the opening / closing spring in a narrow case that accommodates the movable contactor portion and the opening / closing mechanism portion. An object of the present invention is to provide an opening / closing mechanism for a circuit breaker in which the opening / closing spring can be attached to the opening / closing mechanism portion in advance to simplify the assembly.

[Means for Solving the Problems]

To achieve the above object, the present invention includes a toggle link including an upper link connected to a latch and a lower link connected to a movable contact holder, and a center link connecting the upper link and the lower link. In the opening / closing mechanism of the circuit breaker in which the opening / closing spring is stretched between the pin and the operation handle lever, the center pin of the toggle link is held by the upper link, and the center pin is attached to the connecting end of the lower link with the upper link. A U-shaped groove having an opening to be introduced is formed, and a leaf spring having a hole at its free end that overlaps with the U-shaped groove is fixed to the lower link at its base end to fix the opening of the U-shaped groove. By closing and introducing the central pin into the U-shaped groove while elastically deforming the leaf spring,
The upper link and the lower link are connected to each other.

[Action]

The center pin of the toggle link is held by the upper link rather than being inserted when connecting the upper link and the lower link. Thereby, the opening / closing spring can be attached in advance to the opening / closing mechanism portion including the upper link. Then, when the opening / closing mechanism part is installed in the case in which the movable contactor part is already installed, if the central pin is fitted into the U-shaped groove of the lower link attached to the movable contactor part while expanding the leaf spring, The upper link and the lower link can be connected.

【Example】

1 to 4 show an embodiment of the present invention in a circuit breaker for wiring, FIG. 1 is a longitudinal sectional view of an opening / closing mechanism portion of a circuit breaker for wiring, and FIG. 2 is a toggle link in FIG. 3 is an exploded perspective view of FIG. 3, FIG. 3 is a front view for explaining how the upper link is connected to the lower link of the toggle link of FIG. 2, and FIG. 4 (A) is a front view of FIG. A front view of the toggle link and FIG. 4 (B) are side views thereof. First, in FIG. 1, 1 is a case, 2 is a cover,
The case 1 includes a fixed contact 3, which also serves as a power supply side terminal, a movable contact 4, a lead wire 5, an electromagnetic trip device 6, and a load side terminal 7.
Are housed, and the energization path is constituted by these. The movable contactor 4 is supported by an insulator movable contactor holder 8 by a shaft 9 and is urged toward the fixed contactor 3 by a contact spring (not shown). The movable contact holder 8 is rotatably supported by the case 1 by an opening / closing shaft 10 which is integral with the movable contact holder 8. Further, a support frame 11 having side walls on both sides of the movable contact holder 8 is attached to the case 1, and a latch 12 is rotatably supported by a pin 13 on the support frame 11. The latch 12 is normally locked to a latch receiver 15 supported by the support frame 11 by a pin 14 and is prevented from rotating counterclockwise. Also, the latch receiver 15 is
Is abutted against the pawl 18 of the crossbar 17 supported by the support frame 11, and its clockwise rotation is blocked. A toggle link 19 is provided between the latch 12 and the movable contact holder 8. This toggle link 19 pin
The upper link 21 is connected to the latch 12 at 20, and the lower link 23 is connected to the movable contact holder 8 at a pin 22, and they are connected to each other by a central pin 24. Reference numeral 25 denotes a bifurcated operation handle lever having an operation handle 26 attached, and a semi-circular groove (not shown) at the tip of both legs is fitted to a pin (not shown) protruding from the side wall of the support frame 11 to swing to the left and right in the figure. Supported as possible. An open / close spring 27 is stretched between the operation handle lever 25 and the center pin 24 of the toggle link 19 by hooking both ends thereof. The drawing shows the closed state of the circuit breaker, and the opening / closing spring 27 applies contact pressure to the movable contactor 4 via the toggle link 19. In such a configuration, when the operation handle 26 is turned off to the right from the state shown in the drawing, the toggle link 19 is reversed and the movable contactor 4 is separated as the spring force of the opening / closing spring 27 exceeds the dead point. When a short circuit occurs in the circuit, the armature 8 of the electromagnetic trip device 6 is attracted and hits the crossbar 17. As a result, the pawl 18 rotates clockwise and the engagement a with the latch receiver 15 is released. Therefore, the latch receiver
15 rotates clockwise, and the engagement b with the latch 12 is released.
As a result, the unlocked latch 12 rotates counterclockwise, the spring force of the opening / closing spring 27 crosses the dead point, and the movable contact 4 is rapidly opened. Next, the configuration of the toggle link 19 will be described. In FIG. 2, the center pin 24 is held by the upper link 21.
The center pin 24 is press-fitted into and fixed to a through hole formed in a connecting end of the upper link 21 with the lower link 23, and both ends thereof project to the side of the upper link 21. On the other hand, a U-shaped groove 28 having an opening for introducing the central pin 24 is formed at the connecting end of the lower link 23 with the upper link 21. Further, leaf springs 29 each having a long hole 29a overlapping the U-shaped groove 28 are attached to both side surfaces of the lower link 23 at free ends. The leaf spring 29 is welded to the lower link 23 at its base end so as to close the opening of the U-shaped groove 28 leaving a hole for passing the center pin 24, and its tip is slightly bent outward. The upper link 21 and the lower link 23 can be connected by abutting each other. That is, as shown in FIG. 3, both ends of the center pin 24 are leaf springs.
When the tip end of 29 is contacted, the leaf spring 29 is elastically deformed in the axial direction of the central pin 24, and the central pin 24 is introduced into the U-shaped groove 28. Then, when the center pin 24 hits the bottom of the U-shaped groove 28, the leaf spring 29 returns to its original position, closing the opening of the U-shaped groove 28 to prevent the center pin 24 from coming out. FIG. 4 shows the toggle link 19 connected in this way. Now, as described above, since the center pin 24 is held by the upper link 21, the opening / closing spring 27 causes the upper link 21 to move.
Can be extended from the lower link 23. Therefore, the following circuit breaker can be assembled. First, the movable contactor 4, the movable contactor holder 8 to which the lower link 23 is attached, and the movable contactor portion including the electromagnetic trip device 6 connected to the movable contactor 4 by the lead wire 5 and the like are put together in the case 1. Incorporate. Then the top link
Latch 12 with 21 attached, crossbar 17, latch receiver 1
8. An operation handle lever 25 equipped with the operation handle 26 is attached to the support frame 11, and an opening / closing mechanism portion in which an opening / closing spring 27 is stretched between the center pin 24 and the operation handle lever 25 is incorporated in the case 1. Then, the upper link 20 and the lower link 23 are butted and connected. As described above, if the opening / closing spring 27 is attached to the opening / closing mechanism part that is partially assembled outside the case 1, it is not necessary to stretch the opening / closing spring 27 in the narrow case 1, so that even an unskilled person can easily perform the work. It can be performed.

[Effect of device]

According to the present invention, since the opening / closing spring can be attached in advance to the opening / closing mechanism part which is partially assembled, the labor and skill for stretching the opening / closing spring in a narrow case are not required. Further, since the opening / closing mechanism portion can be connected to the movable contactor portion by butting, the opening / closing mechanism portion can be automatically incorporated into the case by the assembly machine.

[Brief description of drawings]

1 shows an embodiment of the present invention, FIG. 1 is a longitudinal sectional view of an opening / closing mechanism portion of a circuit breaker, FIG. 2 is an exploded perspective view of a toggle link in FIG. 1, and FIG. 3 is a toggle shown in FIG. The front view explaining the state which connects the lower link of a link and an upper link, FIG. 4 (A) is a front view of the toggle link of FIG. 2 which connected the upper link and the lower link, FIG. 4 (B). Is a side view thereof. 4 ... Movable contact, 8 ... Movable contact holder, 12 ... Latch, 19 ... Toggle link, 21 ... Top link, 23 ...
Lower link, 24 …… Center pin, 25 …… Operating handle lever, 27 …… Opening spring, 28 …… U-shaped groove, 29 …… Leaf spring.

Claims (1)

[Scope of utility model registration request] 1. A toggle link comprising an upper link connected to a latch and a lower link connected to a movable contact holder, between a central pin connecting the upper link and the lower link and an operating handle lever. In a circuit breaker switching mechanism in which a switching spring is stretched over, a center pin of a toggle link is held by an upper link, and an opening for introducing the central pin is provided at a connecting end of the lower link with the upper link. A U-shaped groove is formed, and a leaf spring having a hole at its free end that overlaps the U-shaped groove is fixed to the lower link at its base end to close the opening of the U-shaped groove, and the leaf spring is elastic. An opening / closing mechanism for a circuit breaker, wherein the upper link and the lower link are connected by introducing the central pin into the U-shaped groove while deforming.