JPS62123630A - Latch releasing mechanism of circuit breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field 1] The present invention relates to a latch tripping mechanism for a circuit breaker that is interposed between a power source and a load and has a function of cutting off power supply to the load when an abnormality is detected in the load. It is something.

[Background Art 1] Generally, in this type of circuit breaker that cuts off power supply to a load when an abnormality is detected in the load, one end of a movable contact that opens and closes the contact, and a latch of a latch mechanism that is driven when an abnormality is detected. When the latch piece is tripped, the latch piece is pulled away from one end of the movable contact, the movable contact trips, and the contacts are opened and separated. 13th
The figure shows a conventional latch state. In this case, it is a so-called surface latch, in which a flat movable contact (B) makes surface contact with the upper surface of the engagement groove of the latch piece (A). The condition is maintained. In this case, the contact is surface contact,
This is sliding friction. Also,! The pH4 diagram shows a so-called transport latch, in which the movable contact (C) is supported on the shaft of the almost circular shaft hole (E) in the bearing plate, and this shaft (D) is supported by the latch piece (I). ) to maintain the latched state. In this case, the contact is point contact, but there is sliding friction between the latch piece (a) and the shaft (d). Therefore, since both are sliding friction, there is a problem in that the coefficient of friction is large.

[Objective of the Invention 1] The present invention has been provided in view of the above-mentioned points, and provides a circuit breaker latch whose purpose is to reduce the latch tripping load by lowering the friction coefficient of the latch surface. It provides a tripping mechanism.

[Disclosure of the invention 1 Embodiments of the present invention will be described below with reference to the drawings.

1 to 11 show an embodiment of the present invention, in which a pair of circuit breaker bodies A are housed in a housing 1 formed by a left and right cover 18.1b, a housing body 1c, and a caulking pin 1d. They are housed side by side on both sides of the main body 1c so that the breaking operations of both circuit breaker main bodies A are linked. A handle 2 disposed on the upper surface of the housing 1 has a connector 21 pivotally supported by a handle shaft 20 protruding from a seven-frame frame 3, and a connector 21 of both circuit breaker bodies A that engages with each other. A handle body 22 having a joint portion 22a formed at one end and an operating portion 22b formed at the other end;
It is formed with an auxiliary spring 23 that easily drives the handle 2 to the OFF side, and serves as a common handle for both circuit breaker bodies A, and the handle 2 can be freely rotated by a predetermined angle around the handle shaft 20. When the handle 2 has its operating portion 22b protruding from the housing 1, the breaking contact is in the OFF position, and when it is in the recess on the upper surface of the housing 1, the breaking contact is in the ON position.

The movable contact 5 connected to the handle 2 via the trip link mechanism 4 has one end latched by the latch mechanism 6 and the center portion connected to the handle 2 via the trip link mechanism 4, a movable contact main body 5a. and the movable contact body 5a
The central part is supported by a rotating shaft 50 provided at the other end, and the tip is provided with a movable contact 7, and the base is a contact part of the movable contact main body 5a (in the embodiment, a U-shaped connecting fitting 4o). The movable contact piece 5b is prevented from rotating in one direction by coming into contact with the leg portion 40b (also used as the leg portion 40b).

Here, the trip link mechanism 4 inserts one leg 40a of the U-shaped connecting fitting 40 that connects the handle 2 and the movable contact body 5a into the shaft hole 41 of the handle 2, and inserts the other leg 40a into the shaft hole 41 of the handle 2. 40b is inserted into the shaft hole 43 in the center of the movable contact main body 5a through the idle hole 42 bored in the frame 3.
The legs 40a and 40b, which serve as connecting shafts between the handle 2 and the movable contact 5, and the handle shaft 20, which pivotally supports the handle 2, are arranged in a toggle manner, and a biasing spring 11, which will be described later, is attached to the movable contact body 5a. It is formed by applying a reversing force.

The latch mechanism 6 for fixing one end of the movable contact 5 includes a latch piece 61 rotatably supported by a rotation shaft 60 protruding from the frame 3 and provided with an engagement groove 62. The movable contact body 5a is formed with a coil spring 63 that biases the latch piece 61 in the latch direction, and the movable contact body 5a
When a locking bar 52 provided at one end of the holder 52 is engaged with the locking bar 52, the locking bar 52 is locked or latched.

The locking bar 52 is rotatably supported in a shaft hole 5c formed in both sides of the movable contact main body 5a. Shaft hole 5c
As shown in FIG. 1, the latch piece 61 is in the trip state.
is driven and the locking bar 52 engages the engagement groove 6 of the latch piece 61.
2 is a long hole extending in substantially the same direction as the direction in which the latch piece 61 is released.

Therefore, the coefficient of friction can be reduced by receiving the latch portion by the rolling friction of the shaft of the locking bar 52. In other words, when tripping, the latch piece 61
When is rotated to the left in Fig. 1, Fig. 12(a)
As shown in FIG. 2, the locking bar 52 rolls along the long hole direction of the shaft hole 5C, and no sliding friction occurs.

Here, if the shaft hole 5c' is circular instead of a long hole as shown in FIG. 12(b) (conventional), the locking bar 52 hardly rolls and sliding friction enters, reducing the coefficient of friction. It will not be possible to achieve this goal.

In addition, in the fixed contact terminal 9, which is a terminal fitting having a fixed contact 8 at one end and a terminal screw 90 for connecting an electric wire and a holding fitting 91 at the other end, the fixed contact 8 faces the movable contact 7, A terminal screw 90 is arranged so as to be located on a terminal block 92 formed on one side of the housing 1, and the fixed contact 8 and the movable contact 7 can be freely brought into and out of contact with each other by rotation of the movable contact 5. . This movable contact 7 and after fixing i
, 8 is provided with an arc-extinguishing chamber in which an arc-extinguishing plate 7o is disposed, so that the arc quickly extinguished when the interrupting contact is opened. Also,
A movable contact terminal 95 provided with a terminal screw 96 and a holding metal fitting 97 and electrically connected to the movable contact piece 5a via a wire #i94 and an exciting coil 100 is arranged on a terminal block 98 provided on the other side of the housing 1. There is. Further, an auxiliary contact block 13 for obtaining an auxiliary contact output that is switched in conjunction with the breaking contact is provided with an auxiliary terminal block 72 on which an auxiliary contact terminal 71 is arranged, and on the back side of the auxiliary terminal block 72. The small limit switch 73 and a boss protruding from the inner surface of the housing 1 are fitted into a shaft support hole 74a in the center and are rotatably supported, so that the small limit switch 73 is pressed in conjunction with the movable contact 5. This auxiliary contact block 13 is formed by an interlocking arm 74 that suppresses and drives the button 73a, and is fitted into an opening 75 of the housing 1.

On the other hand, the abnormality detection mechanism 10 that drives the latch mechanism 6 in the latch release direction when an abnormality is detected in response to the load current includes an excitation coil 100 through which the load current flows, a fixed iron core that is inserted into the excitation coil 100, and a movable iron core. The core is opposed to the core in oil via a return spring to obtain appropriate delayed excitation characteristics, the yoke 102 is integrally formed with 7 frames 3, and the center part is the frame 3. A latch engagement piece 10 is pivoted by a rotating shaft protruding from the holder and is engaged with a suction piece 103a and a latch piece 61 at both ends, respectively.
A driving metal fitting 103 whose center portion, where 3b is formed, is pivotally supported by a rotating shaft 105 protruding from the frame 3;
Coil spring 104 that biases 03 in the opposite direction to the suction direction
When a load current of a predetermined value or more flows, the oil dashpot 101 attracts the suction piece 103a of the drive fitting 103, the drive fitting 103 rotates, and the latch engagement piece 103b The latch piece 61 is driven in the latch release direction.

By the way, the biasing spring 11 that biases the base of the movable contact piece 5b in a direction in which rotation is prevented is a locking piece 30 provided protruding from the frame 3 and a locking piece provided on the movable contact piece 5b. 51
The elastic return force of the biasing spring 11 provides contact pressure, and the reversing force of the trip link mechanism 6 is obtained. In this case, since the movable contact 7 is disposed on the rotatable side surface of the movable contact piece 5b, contact pressure by the biasing spring 11 is applied to the interrupting contact.

On the other hand, an interlocking disconnection mechanism 15 that interlocks the disconnection operations of the circuit breaker bodies A arranged in parallel is fitted into shaft protrusions 81 protruding from both sides of the housing body 1c, and has engaging protrusions 82 protruding from the housing body 1c. A connecting pin 84 protruding from one connecting body 83 is passed through an arc-shaped hole for inserting a pin into the other connecting body 8.
By fitting into the bottle insertion hole 85 of No. 3, both connecting bodies 8
3 are linked together. The engagement protrusion 82 of the connecting body 83 is arranged so as to come into contact with the upper surface of the new curved portion of the drive fitting 103, and when the movable contact 5 is in the trip state (the state shown in FIG. 10), the movable contact It is designed to be pressed down at the latch side end of 5. therefore,
When one circuit breaker main body A is in a tripped state, the connecting body 83 rotates and the drive fitting 103 of the other circuit breaker main body A is forcibly rotated counterclockwise, and the latch mechanism 6 is released from the latch of the movable contact 5, and the cutoff contact is forcibly turned off. In this case, the ring-shaped portions of both connectors 83 close the arc-shaped holes through which the connector pins 84 are inserted, and air flow is blocked, so that the housing body 1
The housings of the circuit breaker body A formed on both sides of c are separated to prevent harmful gas from entering the other housing due to the arc generated at the breaking contact of the circuit breaker body A in one housing. This makes it possible to prevent the adverse effects of harmful gases and improve interelectrode insulation. Further, in the embodiment, the interlocking cutoff mechanism 15 is formed using a pair of connecting bodies 83 having the same shape, and cost reduction is achieved by using common parts.

The operation of the embodiment will be described below with reference to FIGS. 8 to 11. Now, FIG. 8 shows a case where the handle 2 is in the off position, the movable contact 7 and the fixed contact 8 are in an open state, and the cutoff contact is turned off. In this state, the biasing spring 11 The contactor 5 is pulled up, and the locking bar 52 of the movable contactor 5 is engaged with the engagement groove 62 of the latch piece 61 of the latch mechanism 6. Next, Figure 9 shows the handle 2.
is rotated and set from the off position to the on position, thereby rotating the movable contact 5, whose one end is latched by the latch mechanism 6, about the locking bar 52,
A case is shown in which the movable contact 7 and the fixed contact 8 are brought into elastic contact to turn on the interrupting contact. When the handle 2 is turned on, the handle 2 is biased against the biasing force of the biasing spring 11 until the handle shaft 20 and both legs 40a, 40b of the drive fitting 40, which is an interlocking shaft, are aligned. The connecting fitting 40 is rotated while stretching the spring 11, and after passing the dead center, the connecting fitting 40 is automatically moved by the urging force of the urging spring 11.
The leg portion 40b is rotated until it reaches the lower end of the idle hole 42, and is set at a predetermined on position.
A reversal operation similar to a so-called toggle switch is performed. At this time, the movable contact main body 5a is prohibited from moving upward near the lower end of the id hole 42, and the base of the movable contact piece 5b is prevented from rotating by the biasing spring 11. Since the movable contact piece 5b is biased in the direction, a clockwise rotational moment is applied to the movable contact piece 5b. Therefore, as shown in FIG. 9, at the desired position where the movable contact contacts the fixed contact 8, contact pressure by the biasing spring 11 is obtained. FIG. 10 shows a case where a large load current flows, the abnormality detection mechanism 10 is activated, and the movable contact 5 is unlatched by the latch mechanism 6, resulting in a trip state and the breaking contact is forcibly ORed. , when a large load current flows through the excitation coil 100, the oil dashpot 101 causes the drive fitting 10 to
The suction piece 103a of No. 3 is delayed and suctioned to the right, and the drive fitting 1
03 rotates counterclockwise and presses the lower end of the latch piece 61 to the left with the engagement piece 103b. Due to this pressure, the latch piece 61 rotates clockwise, the locking bar 52 of the movable contact body 5a is unlatched by the engagement groove 62, and the movable contact 5 is rotated around the leg portion 40b of the drive fitting 40. By rotating counterclockwise, the movable contact 7 is separated from the fixed contact 8, and the cutoff contact is turned off. At this time, the latch side end of the movable contactor 5 simultaneously pushes down the engagement protrusion 82 of the connecting body 83 of the interlocking interrupting mechanism 15, so that the interrupting contact of the other circuit breaker main body A is turned off. . Immediately after entering this trip state, the movable contact 5 returns to its original position due to the returning force of the urging spring 11, and the handle 2 also returns to its original position as shown in FIG. It will return to the off position shown in .

FIG. 11 is a schematic diagram showing the above operation.
shows the off state, (b) the on state, and (c) the trip state.

E Effects of the Invention 1 As described above, the present invention includes a handle which has one end pivoted and the other end rotatably operated, one end engaged with a latch mechanism, and a central part engaged with a trip link mechanism. A movable contact that is connected to a handle and has a movable contact facing a fixed contact at its tip, a biasing spring that biases the movable contact in a predetermined direction, and an abnormality detection mechanism that detects an abnormality in the load current. and having both ends of a locking bar that engages with the engagement groove of the latch piece of the latch mechanism to maintain the latched state are pivotally supported in a shaft hole drilled in one end of the movable contact body, The shaft hole is formed into a long hole extending in substantially the same direction as the release direction of the latch piece in which the latch piece is driven by the abnormality detection mechanism in the trip state and the retaining groove of the latch piece is released from the locking bar. Compared to the conventional system where sliding friction is caused by surface contact or point contact, the shaft hole in which the locking bar is pivoted is made into an elongated hole, so that when the locking bar and the latch piece come apart, the locking bar will move through the elongated hole. Since the shaft hole rolls, the rolling friction of the shaft can reduce the friction coefficient, and the friction coefficient at the latch part is reduced, so there is no need to increase the so-called lever ratio of the mechanism. The size can be reduced, the electromagnetic tripping force can be small, the coil can be made smaller and lighter, and furthermore, since the number of latches can be increased, mistrips can be reduced.

[Brief explanation of drawings]

FIG. 1 is a side view of a main part of an embodiment of the present invention, FIG. 2 is an exploded perspective view of the same circuit breaker, FIG. 3 is an exploded perspective view of the main part of the same, and FIG. 4 is an external perspective view of the same. , FIG. 5 is a top view of the same as above, FIG. 6 is a side view of same as above, FIG. 7 is a longitudinal sectional view of same as above, FIGS. Figure 11 is an explanatory diagram of the same operation as above, Figure 12 is an explanatory diagram of the same operation as above, Figure 13 is a sectional view of the main part of a conventional latch in case of surface contact, and Figure 14 is a point diagram of another conventional latch. FIG. 3 is a sectional view of main parts in the case of contact. 2 is a handle, 4 is a trip link mechanism, 5 is a movable contact, 5C is a shaft hole, 6 is a latch mechanism, 7 is a movable contact, 8 is a fixed contact, 10 is an abnormality detection mechanism, 11 is a biasing spring, 52
61 represents a locking bar, 61 represents a latch piece, and 62 represents an engagement groove. Agent Patent Attorney Ishi 1) Chief 71〆C Section 5 ■ Figure 6 Figure 7 Figure 12 Figure 1113 Figure 14

Claims (1)

[Claims] (1) A handle with one end pivoted and the other end rotatable, one end engaged with a latch mechanism, the center part connected to the handle via a trip link mechanism, and a fixed contact at the tip. It has a movable contact having a movable contact facing the latching mechanism, a biasing spring that biases the movable contact in a predetermined direction, and an abnormality detection mechanism that detects an abnormality in the load current. Both ends of the locking bar, which engages with the engagement groove to maintain the latched state, are pivotally supported in a shaft hole drilled in one end of the movable contact body, and the shaft hole is used to detect an abnormality in a trip state. A latch removal mechanism for a circuit breaker, which is formed as a long hole extending in substantially the same direction as the releasing direction of the latch piece, in which the latch piece is driven by the mechanism and the engagement groove of the latch piece is disengaged from the locking bar.