JPS5850593Y2 - circuit break - Google Patents

Description

[Detailed description of the invention] This invention relates to a circuit breaker, in particular a circuit breaker in which the separation distance between the contacts is short when the circuit is manually opened, and longer when it is automatically opened in response to an overcurrent. The purpose is to improve

Conventionally, this type of circuit breaker has a movable contact device, an operating device for the movable contact device including a toggle link, and a trip lever that can be rotated to automatically open the movable contact device in response to an overcurrent. A stop piece provided on the toggle link so as to move together with the toggle link in the case of normal opening engages with a stop piece of the trip lever in the reset state, so that the opening distance of the movable contact device is limited to a short distance. In the case of automatic opening, as the trip lever rotates, the stopper of the trip lever is released and the opening distance of the movable contact device becomes longer. In the event of an open circuit, the stop piece that moves together with the toggle link engages with the stop piece of the trip lever to limit the separation distance of the movable contact device, so the impact force at the time of open circuit is transmitted to the trip lever, and one end of the trip lever This engaging part maintains a delicate balance in connection with the automatic release caused by the activation of the overcurrent response device, so the impact of the trip lever may cause the balance to collapse and the securing part to come off. This has the disadvantage that it is easy to cause so-called intermittent trips.

This idea is an improvement to eliminate the above-mentioned drawbacks.
It comprises a movable contact device, an operating device comprising a toggle link to actuate the movable contact device, and a trip lever rotatable to automatically open the movable contact device, with a toggle link in case of normal opening. A stop piece provided on the link and moving together with the toggle link comes into contact with a stopper provided on the fixed frame at the first position to shorten and limit the separation distance of the movable contact device from the fixed contact, thereby automatically opening the device. In this case, the rotation of the trip lever releases the engagement between the stop piece provided on the toggle link and the fixed frame, and the stop piece provided on the toggle link follows the rotation of the trip lever and moves to the first position. It comes into contact with a second position different from the contact position and stops,
The separation distance of the movable contact is set longer than in the case of a normal open circuit, that is, the stop piece of the toggle link does not engage with the trip lever in the case of a normal circuit, and the toggle link is closed. The stop piece engages with a stopper provided on the fixed frame.

FIG. 1 is a side cross-sectional view of a three-circuit breaker in a closed state showing an embodiment of this invention, and shows the operating mechanism of a movable contact device connected to its center pole.

In the same figure, the circuit breaker has a molded base 1 and a molded cover 2 made of an insulating material as outer coverings, external connection terminals 3 and 3' are provided, and one end of the power supply side connection terminal 4 is provided with external connection terminals 3 and 3'. is connected to an external connection terminal 3, and a fixed contact 5 is fixed to the other end.

The movable contact preliminary 7 has a movable contact 6 at a position corresponding to the fixed contact 5, is rotatably supported by a contact holder 9 by a shaft 8, and has one end connected to an intermediate connector by a flexible conductor 10. It is connected to 11.

The lower end of the bimetal 12, which is a thermal member of the overcurrent response device, is connected to the intermediate connector 11 by an intermediate connector 11'.
The upper end is connected to one end of a load-side conductive terminal 14 via a flexible conductor 13, and the other end of this load-side conductive terminal 14 is connected to an external connection terminal 3'.

The intermediate connectors 11 , 11 ′ are electrically connected together by intermediate connection terminals 15 .

The adjustment screw 16 is attached to the upper end of the bimetal 12 and corresponds to the tripping rod 17, so that the opposing gap with the tripping rod 17 can be adjusted.

A fixed core 18 of the electromagnetic tripping device surrounds the bimetal 12 in a U-shape and is supported by a fixed core support plate 19.

The movable iron piece 20 of the electromagnetic tripping device is provided so as to correspond to the fixed iron core 18, and operates the lower end of the tripping rod 17 when the movable iron piece 20 is attracted to the fixed iron core 18.

A hook 21 having a hook pin 21a is attached to the tripping rod 17.
It is rotatably supported integrally with the fixed frame 24.

The operation mechanism and release device of the movable contact device, which is composed of the movable contact preliminary 7 having the movable contact 6, is provided by the mold cover 2.
an operating handle 2 made of an insulating material and protruding outward from the
2, and an inverted U-shaped opening/closing lever 23 fixed to the operating handle 22. The lower end of the opening/closing lever 23 is rotatably supported by an opening/closing lever shaft 25 fixed to a fixed frame 24. ing.

One end of the trip lever 26 is rotatably supported on a trip lever shaft 27 bridged by the fixed frame 24, and the claw portion 26a at the other end is a hook pin 2 provided on the hook 21.
1a is releasably engaged.

Each end of the pair of toggle links 28 and 29 is rotatably connected by a connecting shaft 30, and the other end of the toggle link 28 is attached to the upper center end of the trip lever 26 by a toggle link attachment shaft 31.

When the trip lever 26 and the hook 21 are set and the circuit is normally opened, the connection shaft 30 of the toggle link becomes a locking piece provided on the toggle link, and the stopper 24 a that engages with this becomes a locking piece provided on the toggle link. It is formed in the notch, and restricts the movement of the toggle links 28 and 29, and when it is automatically opened, the lock is released, and the separation distance between the movable contact 6 and the fixed contact 5 during normal opening and automatic opening is reduced. They are configured differently.

An opening/closing arm 32 made of an insulating material is connected to the end of the contact holder 9 and is linked to a movable contact device of the other pole.
It can be rotated to the open position using the operating mechanism using the fulcrum as the fulcrum.

The contact spring 34 has the function of always biasing the movable contact preliminary line 7 in the direction of closing the circuit.

Further, the operation spring 35 is connected to a pair of toggle links 28.
, 29 and the upper end of the opening/closing lever 23.

To explain the opening/closing operation of the circuit breaker of this invention constructed in this way, in the closed circuit state shown in FIG. 1, the circuit can be opened by manual operation by moving the operating handle 22 to the OFF side, and the line of action of the operating spring 35 is reversed. A pair of toggle links 2
8.29 is bent into an inverted dogleg shape as shown in FIG.
The connecting shafts 30 of the toggle links 28 and 29 act as locking pieces to connect the stopper 24 a provided at the upper edge of the fixed frame 24 to the first position. The movable contact 6 and the fixed contact 5 come into contact with each other and the separation distance is limited, resulting in an open state in which the separation distance between the movable contact 6 and the fixed contact 5 is a distance LX.

Next, to explain the automatic opening operation, if an overload current flows in a closed circuit state as shown in Figure 1,
Either the bimetal 12 is bent due to overheating and the adjusting screw 16 rotates the tripping rod 17 counterclockwise, or the fixed iron core 18 for removing the electromagnetic train is energized and attracts the movable iron piece 20, thereby removing the hook 21. is rotated counterclockwise and the third
As shown in the figure, the hook pin 21a and the tip claw portion 26a of the trip lever 26 are disengaged, and the trip lever 26 is rotated counterclockwise about the rotation shaft 27 by the acting force of the operating spring 35. and toggle link 2
8.29 is pulled up and the toggle link 28.29 crosses the line of action of the operating spring 35, these pair of toggle links 28.29 are bent and the toggle link 28.29
When the locking piece of the connecting shaft 30 is released from the notch stopper 243 of the fixed frame 24, the contact holder 9
is pulled up, and following the rotation of the trip lever 26, the movable contact 6 moves away from the fixed contact 5 until the locking piece of the connecting shaft 30 of the toggle link touches the lower edge of the trip lever. separated.

The opening distance at this time is an open circuit state shown in FIG. 3, which is a distance L2 which is longer than the distance L1 shown in FIG. 2.

At this time, the locking piece of the connecting shaft 30 of the toggle link was made to stop at the open position where it hits the lower edge of the trip lever 26, but the open position of the movable contact device was controlled by a stopper provided on a separate fixed frame. There is no harm in limiting it.

Opening and closing during normal operation improves durability by shortening the opening distance as much as possible, reducing damage to the flexible conductor 10 and chattering of the movable contact 6, and especially when automatic shutoff is performed due to short circuit current, etc. In order to increase the breaking performance by increasing the separation distance, in the case of normal opening, the stop piece provided on the toggle link engages with the stop piece of the trip lever in the reset state, so that the movable contact is opened. The applicant has already proposed a circuit breaker that limits the distance to a short distance, but in the case of automatic opening, this type of circuit breaker rotates the tripping rod and hook in response to the overcurrent response device. Then, the trip lever that engages with the hook is released, the opening/closing operation mechanism is collapsed, and the movable contact device is pulled up by the operation spring force. Therefore, the secured state of the trip lever and hook allows for smooth automatic opening operation. It is a factor that has a large influence on the performance of the trip lever, and during normal circuit opening operations, when the stop piece provided on the toggle link engages with the stop piece of the trip lever, the impact force is transmitted to the trip lever, so it is used for a long time. It has become clear that the balance between the retaining portion between the trip lever and the hook is lost, and the retaining portion is likely to come off, resulting in a so-called inter-trip.

Therefore, this idea prevents the impact force of the stop piece provided on the toggle link during normal circuit opening from being applied directly to the trip lever, thereby limiting the separation distance between the movable contact and the fixed contact to be short. This is intended to improve the above-mentioned drawbacks.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing a circuit breaker in a closed state according to an embodiment of the invention, FIGS. 2 and 3 are side views of essential parts showing a normal open state and an automatic open state, respectively. 6 to 6 are simplified explanatory diagrams showing operating states, FIG. 4 shows a normal open circuit state, FIG. 5 shows a closed circuit state, and FIG. 6 shows an automatic open state. In the figure, 1: mold base, 2: mold force bar, 3.
3': External connection terminal, 5: Fixed contact, 6: Movable contact, 9: Contact holder, 12: Bimetal, 17
: Trip rod, 18: Fixed iron core, 20: Movable iron piece, 21:
Hook, 21a: Hook pin, 22: Operating handle, 23: Opening/closing lever, 26: Trip lever, 27: Trip lever shaft, 28.29 Nidoguru link, 32: Opening/closing arm, 34: Contact spring, 35: Operating spring.

Claims (1)

[Scope of utility model registration request] 1. a movable contact device; an operating device having a toggle link for actuating the movable contact device; and a lever lever rotatable to automatically open the movable contact device; A stop piece provided on the toggle link and moving together with the toggle link contacts a stopper provided on the fixed frame at a first position to shorten and limit the separation distance of the movable contact device from the fixed contact;
In the case of automatic opening, the stop piece provided on the toggle link moves together with the rotation of the trip lever, following a trajectory different from that in the case of normal opening, and reaches the first contact position. The circuit breaker is configured to abut and stop at a second position different from the circuit breaker, and to set an opening distance longer than the normal opening distance. 2. The circuit breaker according to claim 1, which is a registered utility model, in which a stop piece provided on the toggle link is in a second abutting position when the trip lever is in a rotating position when automatically opened. 3. The circuit breaker according to claim 1 or 2, wherein the stop piece provided on the toggle link is an extension of the toggle link connecting shaft.