JPH0334036Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention relates to a device for preventing restriking of a circuit breaker, and in particular to a device for preventing restriking due to the rebound of a movable contact when a large current is interrupted. be.

[Conventional technology]

FIG. 7 is a perspective view of a main part of a conventional device, and a circuit breaker which is the background for using this device will be described later in FIG. In FIG. 7, trip lever 1
02 constitutes a part of a releasable device rotatably supported by a trip lever shaft 103 mounted on a fixed frame 101, and includes a pair of toggle links 10.
4, 105 are each rotatably connected at one end by a connecting shaft 106, and the other end of the toggle link 104 is connected to the trip lever 102 by a shaft 107.
The other end of the toggle link 105 is the contact lever 1
It is rotatably supported by a shaft 109 provided on a bearing plate 108' which is integrally fixed to 08. 3
A contact lever shaft 110 for interlocking poles is connected to one end of the contact lever 108 of each pole. Rotation shaft 11 provided on fixed frame 101
A contact holder (not shown) equipped with a movable contact device is connected by a contact holder shaft 112 to the other end of the contact lever 108 that is pivotally supported by the contact lever 108, and the contact lever 108 rotates clockwise to release the movable contact device. The circuit is opened by pushing down, and the circuit is closed by rotating the contact lever 108 counterclockwise and pulling up the movable contact device.

As a restriking prevention device, a trip transmission plate 113 is rotatably supported on the fixed frame 101 by a shaft 114, a trip response member 113a integrally provided at one end is provided so as to correspond to the trip lever 102, and the other end is provided so as to correspond to the trip lever 102. A locking lever restraining pin 115 is provided. The lever 116 is shaped, is rotatably supported by a shaft 117 mounted on the fixed frame 101, and is normally biased counterclockwise by a lever spring 118. The latching pin 119 is the contact lever 1
It is installed in 08.

When the circuit breaker disengages from a hook (not shown) that locks the tip of the trip lever 102 due to the operation of the automatic trip response device and automatically shuts off, the trip lever 102 rotates counterclockwise. Lift the trip response pin 113a, rotate the trip transmission plate 113 counterclockwise about the shaft 114, and release the lever restraining pin 115.
move together, and the latch/unhook lever 116 is rotated counterclockwise by the latch/unhook lever spring 118. In this process, the toggle link 104,1
05 is bent and the contact lever 108 is the shaft 1
11 as a fulcrum and reaches the open position, and the tip of the lever 116 is placed at an upper position corresponding to the latching pin 119.
Therefore, when the movable contact device impacts the stopper and rebounds, the contact lever 108 is lifted in the direction of closing the circuit via the contact holder, the tip of the unlatching lever 116 and the latching pin 119 engage with each other. A device has been implemented in which movement of the contact lever 108 in the direction of closing the circuit is prevented to prevent the movable contact device from re-closing the circuit.

[Problem that the invention attempts to solve]

In the conventional device described above, the release lever 116
When the trip lever 102 is released, the release lever 116 operates via the trip transmission plate 113 to prevent the contact lever 108 from moving in the closing direction. However, in the case of interrupting a large current such as a short circuit current, When the trip lever 102 is released, the movable contact receives electromagnetic repulsion and rapidly moves to the open position, and because it is rebound, the contact lever 108 moves quickly in the closing direction, and the trip lever 102 is released and the trip transmission plate The movement of the latch/unhook lever 116 that is moved via the contact lever 113 is delayed, and the latch/unhook lever 116 is moved by the contact lever 1.
There was a drawback that when the contact lever 108 rebounded, it could not engage with the latching pin 119 provided on the contact lever 108, resulting in re-closing.

Therefore, this invention has been made to solve these drawbacks, and provides a re-strike prevention device for a circuit breaker that can be applied even when the movable contact bounces quickly back to the re-closing position. be.

[Means for solving problems]

According to this invention, a restriking prevention device for a circuit breaker includes an inertia latch that is rotatably supported on a fixed frame, an inertia latch stopper pin that prevents rotation of the inertia latch in one direction, and an inertia latch that is rotatably supported on a fixed frame. an inertia latch operating pin installed on the contact lever to correspond with the inertia latch, an inertia latch spring installed between the inertia latch and the contact lever, and a lock pin provided on the contact lever so as to correspond to one end of the inertia latch when the inertia latch is operated. It is configured.

[Effect]

In the circuit breaker re-strike prevention device of this invention, when a large current is cut off, the inertia latch operation pin hits the inertia latch by rotating the contact lever connected to the movable contact, applying rotational force, and the rotation is caused by the inertia of the inertia latch operating pin. The engagement of the locking pin with the inertia latch in position prevents reclosing of the movable contact.

〔Example〕

As shown in Figures 1 and 2 of the drawings, the circuit breaker provided with the restriking prevention device of this invention includes a mold base 1, a mold cover 2, and an arc extinguishing chamber cover 3.
It has a closed envelope formed by. The L-shaped power supply side fixed contact rod 4 has a power supply side terminal conductor 5 connected to one end and a power supply side fixed contact 6 at the other end. An L-shaped load side fixed contact rod 7 provided symmetrically with the power supply side fixed contact rod 4 has a connecting conductor 8 connected to one end and a load side fixed contact 9 at the other end.

The movable contact rod 10 is divided into two parts, a power side movable contact rod 11 and a load movable contact rod 12, and is rotatably supported between two contact holders 14 by respective support shafts 13, 13'. has been done. The divided ends of the movable contact rods 11 and 12, which are divided into two, form circular arc surfaces centered on the support shafts 13 and 13', respectively.
The configuration is such that the contact between the arcuate surfaces is maintained even during rotation. At the tips of the power source and load side movable contact rods 11 and 12, power source and load side movable contacts 15 and 16 are mounted, which come into contact with and separate from the power source and load side fixed contacts 6 and 9, respectively. The movable contact pins 17, 17' are movable in cutouts on the side edges of the contact holder 14, and a contact spring 18 is installed between the movable contact pins 17, 17'. The balance levers 19, 19' are connected at one end to the movable contact pins 17, 17', respectively, and integrally connected to the balance lever pin 20 at the other end. Balance lever pin 20 is contact holder 14
Balance lever pin guide groove 21 provided in
It is something that can be slid. Note that rollers 22 are attached to both ends of the balance lever pin 20, and the rollers 22 can slide up and down in grooves 23 provided in the molded insulator of the arc extinguishing chamber cover 3. A stopper 24 for the balance lever pin 20 is also provided.

An operation handle 2 is made of an insulating material and has a molded cover 2 protruding as an opening/closing mechanism and a release device for opening and closing the movable contact rod 10 described above.
5, and an opening/closing lever 26 integrated with a rightward protrusion 26' fixed to the operating handle 25,
The lower end of this opening/closing lever 26 is rotatably supported by an opening/closing lever shaft 28 fixed to a fixed frame 27. One end of the trip lever 29 is connected to a trip lever shaft 30 that is bridged over the fixed frame 27.
The other end is rotatably supported by a shaft, and the other end is releasably engaged with the main hook 31 by a claw portion 29a. The pair of toggle links 32 and 33 are rotatably connected at one end by a connecting shaft 34, and the toggle links 32 and 33 are
The other end of the toggle link 33 is connected to the trip lever 29 by a shaft 35, and the other end of the toggle link 33 is rotatably supported on a shaft 37 provided on a bearing plate 36' that is integrally fixed to the contact lever 36. ing. The operating spring 33 is the connecting shaft 3 of the toggle link 33.
4 and the protrusion 26' of the opening/closing lever 16. One end of a contact lever 36 for each pole is connected to a contact lever shaft 39 for interlocking three poles. The other end of the contact lever 36 is connected to the contact holder 14 by a contact holder shaft 40, and rotatably supported by a shaft 41 bridged over the fixed frame 27. The inertia latch 42 having an inverted L shape is rotatably supported at the center by an inertia latch shaft 43 provided on the fixed frame 27, and the side edge 42a of the inertia latch 42
Inertia latch operation pin 44 corresponds to
is provided. This inertia latch operation pin 44 has an inertia latch operation plate 45 mounted integrally with the contact lever 36 on the fixed frame 2.
It is attached to the tip of the arm 45a that is bent outward beyond the point 7.

The inertia latch spring 46 has one end disposed between the lower end of the inertia latch 42 and the other end between the inertia latch operation plate 45 and biases the inertia latch 42 clockwise in the normal closed position. A stopper pin 47 of the inertia latch 42 provided on the fixed frame 27 engages with the upper side 42b of the inertia latch 42, and prevents the inertia latch 42 from rotating clockwise beyond a certain limit. The lock pin 48 is attached to the contact lever 36 so as to engage with the lower edge 43c of the inertia latch 42 when the movable contacts 15, 16 rebound.

The automatic trip response device 49 has one end of the main hook 31 engaged with the trip lever 29 and a secondary hook 50.
engages with the embedded claw 51 of the tripshaft, and the main hook 31 and the secondary hook 50 are operatively engaged and connected in between. The automatic trip response device 49 is housed in an insulator case 52 and connected to the connecting conductor 8.
and the load-side terminal conductor 54 are connected by a main current conductor 53, and an instantaneous tripping electromagnet 55, an instantaneous tripping rod 56, a tripshaft 57, a trip adjustment screw 58, and a bimetal 59 are provided. To explain the opening/closing operation of the circuit breaker having the above structure, Fig. 1 shows the circuit breaker in the closed state, and from this state, the operating handle 25 can be opened by moving the operating handle 25 to the right to the OFF side. Then, the pair of haggle links 32 and 33 are bent, the contact lever 36 is rotated clockwise, the contact holder 14 connected thereto is moved downward, and the rollers 20 at both ends of the balance lever pin 20 are moved against the arc extinguishing chamber cover 3. The movable contacts 15 and 16 slide downward in the groove 23 provided in the mold insulator, and are in an open state where they are separated from the fixed contacts 6 and 9. When closing the circuit, the contact holder 14 is pulled up by operating the operating handle 25 to the left to the ON side, resulting in the closed circuit state shown in FIG. 1 in which the movable contacts 15 and 16 are in contact with the fixed contacts 6 and 9.

Next, to explain the trip operation, when a normal overload current flows in a closed circuit state, the bimetal 59 bends due to overheating, which pushes the trip adjustment screw 58 and rotates the trip shaft 57 clockwise, causing the embedded claw to 51 is disengaged from the secondary hook 50, the secondary hook 50 and the main hook 31 are both rotated clockwise, the trip lever 29 is disengaged, and the pair of toggle links 32, 33 are bent, and the circuit is closed. While maintaining the state of the movable contact rod 10, the contact holder 14 is pushed down to interrupt the circuit. Also, the rated current is 5 to 10
For double overcurrent, instantaneous tripping electromagnet device 5
5 is activated, causing the instantaneous tripping rod 56 to rotate the trip shaft 57 to interrupt the circuit in the same manner as described above.

In addition, when a current such as a short circuit current flows, an electromagnetic repulsion force is generated between the fixed contact rods 4 and 7 and the movable contact rods 11 and 12 due to the current flowing in opposite directions. As a result, while the first contact holder 14 maintains the closed circuit position, the movable contact rods 11 and 12 move against the contact spring 18 using the supports 13 and 13' as fulcrums, and the movable contact rod 11 on the power source side moves back. In the clockwise direction, the load-side movable contact rod 12 rotates clockwise while maintaining electrical contact with each split end, and the movable contact pins 17 and 17' move on the side edge of the contact holder 14. Since the contact spring 18 installed on the movable contact pins 17, 17' reverses beyond its dead center, the movable contacts 15, 16 are kept separated from the fixed contacts 6, 9, and the circuit current is interrupted. be done. During this process, the opening/closing mechanism is collapsed by the operation of the instantaneous tripping electromagnet device 55, and the contact holder 14 is pushed down.
Movable contact rod 11, 1 in a repulsed and rotated state
2 hits the movable contact rod stoppers 60, 60' provided on the molded insulator of the arc extinguishing chamber cover 3,
Furthermore, the contact holder 14 is pushed down until the rollers 22 at both ends of the balance lever pin 20 abut against the stoppers 24 in the groove 23, so that the movable contact rods 11 and 12 return to the state before being rotated by the reaction and are normally opened. state.

Next, the operation of the re-ignition prevention device is explained in Figures 3 to 6.
To explain with the drawings, FIG. 3 shows a closed circuit state, and the inertia latch 42 rotatably supported by the fixed frame 27 is pulled by the inertia latch spring 46 and biased clockwise, and the inertia latch 42 is biased clockwise. The side edge 42b is held in contact with the inertia latch stopper pin 47. If the state changes from this state to an open circuit state,
As shown in FIG. 4, the shaft 4 of the contact lever 36
1 as a fulcrum, the inertia latch operation pin 44 comes into contact with the side edge 42a of the inertia latch 42, and the inertia latch 42 is brought into a state in which the shaft 43 is rotated counterclockwise against the inertia latch spring 46. When this circuit is opened, the movable contact rod 10 receives an electromagnetic repulsion force due to the large current interruption.
The automatic tripping response device 49 is activated and the contact holder 14 and the contact lever 36 are rapidly removed.
When the inertia latch is moved to the open position, the inertia latch actuating pin 44 will impact the inertia latch 42.
The side edge 42a of the inertia latch 42 is struck to apply a counterclockwise rotational force to the inertia latch 42 overcoming the inertia latch spring 46, and due to the inertia of this rotation, the lower edge 42c of the inertia latch 42 comes into contact with the lock pin 48 provided on the contact lever 36. The state shown in FIG. 5 is reached when the robot is moved to the position where Therefore, the contact holder 14 is rapidly moved to the open position, and the rollers 22 at both ends of the balance lever pin 20 collide with the stopper 24 and rebound due to the reaction, causing the contact holder 14 and the contact lever 36 to move back toward the closing direction. However, inertia latch 4 occurs during the rebound process.
The lower end 42c of the contact lever 36 is engaged with the lock pin 48 of the contact lever 36, and further movement in the direction of closing the circuit is prevented, as shown in FIG. As a result, the movable contacts 15 and 16 cannot approach the fixed contacts 6 and 9 any further, and it is possible to prevent re-ignition and re-closing due to a decrease in the separation distance between the contacts.

〔effect〕

As described above, according to the re-strike prevention device for a circuit breaker of this invention, when a large current is interrupted, electromagnetic repulsion is applied to the movable contact and it rapidly moves to the open position, rebounds and returns to the closed position. Even when the return is fast, the inertia latch responds quickly by following the movement of the movable contact in the opening direction, so that the inertia latch and the lock pin reliably engage during the rebound process of the movable contact to prevent re-closing. This has the effect of preventing restriking.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of a circuit breaker showing an embodiment of the circuit breaker restriking prevention device of this invention, Fig. 2 is a perspective view of the main parts, and Figs. 3 to 6 are this figure. 3 shows a closed circuit state, FIG. 4 shows an open circuit state, FIG. 5 shows the operation process of the inertia latch, and FIG. 6 shows a state in which the inertia latch operates to prevent re-closing. FIG. 7 is a perspective view of essential parts of a conventional device. In the figure, 1: mold base,
2: Mold cover, 3: Arc extinguishing chamber cover, 4: Power supply side fixed contact rod, 6: Power supply side fixed contact, 7:
Load side fixed contact rod, 9: Load side fixed contact, 1
0: Movable contact rod, 11: Power side movable contact rod,
12: Load side movable contact rod, 13, 13': Support shaft, 14: Contact holder, 15: Power supply side movable contact, 16: Load side movable contact, 17, 1
7': Movable contact pin, 18: Contact spring, 19, 19': Balance lever, 2
1: Guide groove, 22: Roller, 24: Cut knob, 25: Operation handle, 26: Opening/closing lever, 2
7: Fixed frame, 29: Triple lever, 3
1: Main hook, 32, 33: Toggle link, 3
6: Contact lever, 38: Operation spring,
39: Contact lever shaft, 42: Inertia latch, 44: Inertia latch operation pin,
45: Inertia latch operation plate, 46: Inertia latch spring, 47: Stopper pin, 4
8: Lock pin, 49: Automatic trip response device, 5
0: Secondary hook, 52: Insulator case, 55: Instantaneous tripping electromagnet, 56: Instantaneous tripping rod,
57: Tripshaft, 59: Bimetal.

Claims (1)

[Scope of Claim for Utility Model Registration] A contact holder comprising a fixed contact and a movable contact that comes into contact with and separates from the fixed contact, and an opening/closing operation via a contact lever rotatably supported by a shaft in order to open and close the movable contact. A circuit breaker equipped with an operating mechanism including a toggle link that automatically opens the movable contact, and a trip lever that automatically opens the movable contact, an inertia latch rotatably supported on a fixed frame, and a circuit breaker that prevents rotation of the inertia latch in one direction. an inertia latch stopper pin mounted on the contact lever so as to correspond to the inertia latch, an inertia latch spring installed between the inertia latch and the contact lever, and one end thereof when the inertia latch is operated. The inertia latch operation pin rotates in the opening direction together with the contact lever when a large current is cut off, and rotational force is applied to the inertia latch, and the circuit is closed from the open position of the movable contact. A restriking prevention device for a circuit breaker, wherein the rebound movement of the movable contact is prevented by the engagement of the locking pin with the inertia latch, which is in a rotational position due to the inertia of the inertia latch.