JPH0251819A - Circuit breaker - Google Patents

Abstract

PURPOSE:To reduce the arc current and perform the reliable cutoff operation by providing an instant separation core and an interlocked repulsion shaft. CONSTITUTION:An instant core 20'a and a moving iron 19' are provided below an overcurrent detector (oil dash pot relay), an instant separation moving iron 19' is sucked by the electromagnetic force generated by the current flowing through the electromagnetic coil in the core 20'a. The coupling end with an interlocked repulsion shaft 23' is released by the shift of the movable core 20'a, the interlocked repulsion shaft 23' concurrently strikes multiple poles of a movable contact bed 5 by the invariably excited spring force to perform the opening operation. Multiple poles are concurrently opened, the arc at the time of cutoff can be reduced, the latch of a switching mechanism section due to the overcurrent is released by the rotation of the movable contact, thus the reliable operation can be performed.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a circuit breaker, and in particular, when a large current such as a short circuit current occurs, the contactor is opened and closed without waiting for the normal opening operation. The present invention relates to a circuit breaker that is small in size and suitable for securing high breaking capacity, and performs current-limiting breaking in a short time in combination with the opening operation by the subsequent trip opening/closing mechanism.

(Prior art) Various types of current-limiting circuit breakers that use conventional electromagnetic repulsion are:
When a fixed contact and a movable contact are placed opposite each other and a large current flows due to a short circuit accident, the electromagnetic repulsive force acting between the fixed contacts instantly causes one or both of the contacts to open. to limit the current from the rapid rise of the arc voltage,
Thereafter, after a predetermined delay, the overcurrent tripping device causes the opening/closing mechanism to open the movable joint support attached to the common '/#@edge shaft' of each pole, thereby completely disconnecting the various movable contacts. This results in a closed pole state. As mentioned above, in general current-limiting circuit breakers, a current-limiting mechanism is provided for each pole, and each pole operates independently depending on the magnitude of the current flowing through each pole. In this case, the opening time differs depending on the current rise rate of each phase when a short circuit occurs, and the phase with a large current rise rate has a large electromagnetic repulsion force, so the contact opens quickly, and the phase with a small current rise rate has a large electromagnetic repulsion force. Because it is small, the opening of the contact is delayed. As a result, the phase with a large current increase rate must be shut off first, and then the other phases must be shut off in a single phase (two-point series shutoff), making the disconnection conditions severe and becoming an obstacle to improving the disconnection performance. It had become. To solve this problem, a technique is disclosed in Japanese Patent Application Laid-Open No. 55-9346.

The current limiting mechanism is operated by the electromagnetic force generated in one of the multiple poles or the sum of the electromagnetic forces generated in the multiple poles, and the movable contacts of the multiple poles are simultaneously opened and opened, If multi-pole movable contacts are opened simultaneously, the phase with a small current increase rate will be cut off first, and other phases can be easily cut off by single-phase cutoff, so the maximum current peak value and passing current squared This invention was made focusing on the fact that the product (fi''dt) can be significantly reduced.

(Problems to be Solved by the Invention) FIG. 10(a) shows a closed circuit state of the central one of the three poles of the circuit breaker in the above technique, and FIG. 10(b) shows an open circuit state. A latch 55 is rotatably supported on a movable contact support 53 that supports a central single-pole movable contact 52, and a shaft roller 59 provided at one end of a toggle link 57, 58 is slidable. A multi-polar movable contactor 52 is provided with a guide groove 54 and a torsion spring 56 that normally engages a latch 55 with the shaft roller 59 to maintain the shaft roller 59 in a state engaged with the slope portion of the guide i#54. When the sum of the electromagnetic repulsive forces acting on the torsion spring 56 reaches a predetermined value, it overcomes the elastic force of the torsion spring 56 and releases the engagement with the latch 55, disconnecting the movable contact support 53 from the 9
Since the multi-pole movable contacts 52 are simultaneously opened and opened via the shaft 60, variations in the frictional force between the latch 55 and the shaft roller 59 and between the shaft roller 59 and the guide groove 54 tend to cause variations in operation. In addition, the elastic force of the torsion spring 56 must be strengthened to prevent the latch 55 and the shaft roller 59 from disengaging and malfunctioning due to the impact at the time of closing and closing, and as a result, the movable contact 52 due to electromagnetic repulsion There is a risk that the current limiting effect may not be fully exerted due to the delay in opening of 1! Since the multi-polar movable contact 52 separated by magnetic repulsion cannot be maintained in the separated state, the opening operation of the opening/closing mechanism by the overcurrent tripping device is delayed.

The electromagnetic repulsion caused by the disconnection decreases, causing the movable liquid contactor 52 to return, causing the ignition to occur again and making it impossible to shut off, leaving problems in terms of reliability. The present invention has been made in order to solve the above problems, and aims to provide a new circuit breaker with excellent reliability and breaking performance, which ensures faster simultaneous opening of multiple poles due to electromagnetic repulsion at the time of fault current interruption. This is the purpose.

(Means for Solving the Problem) The above object is to provide a means for disengaging the latch even if the maximum current flows through any of the multipoles, and to provide a multipole core that is attracted by the current flowing during a short circuit. This is achieved by providing a repulsion interlocking shaft that directly operates the movable contact block.

(Function) With the above configuration, operation is reliably started even if the maximum current flows through any of the multipoles, and in particular, the phase that operates first among the multipoles opens the pole and releases the latch of the repulsion interlocking shaft. . By providing this mechanism separately from the opening/closing mechanism, the repulsion operation is performed independently so that there is no influence on the opening/closing ON-FF operation compared to the prior art. In other words, the overcurrent detector (oil dashpot relay) has an instantaneous core and a movable iron piece at the bottom, and when a short circuit current flows, the movable iron piece for instantaneous tripping is generated by the electromagnetic force generated by the current flowing to the electromagnetic coil in the core. is attracted. As the movable core moves, the engagement end with the repulsion interlocking shaft is disengaged, and the repulsion interlocking shaft is thereby struck by the constantly biased spring force against the movable contact base of multiple poles at the same time to open the contacts. Therefore, the opening operation of multiple poles is performed at the same time, which can reduce arcing at the time of disconnection, and the rotation of the movable contact allows for reliable operation by unlatching the opening/closing mechanism due to overcurrent. It is something.

(Example) An example of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of a circuit breaker according to the present invention, and the figure shows the circuit breaker in an ON state. Each component is housed in a case 1 and a cover 2, and for ON-FF operation using the handle 3, the handle 3 is moved from the illustrated position in the direction of arrow R, and the pulling direction of the opening spring 13 is adjusted to the locking portion 3a. and the pin 10 provided on the lever 11 and the movable contact block 5
When the fulcrum pin 10 moves beyond the dead point to the opposite side of the straight line connecting it to the fulcrum 7 of The contact with the fixed contact base 4 is separated and the contact is turned off.

To turn it on again, turn handle 3 to L in the opposite direction.
If it is operated in the direction shown in FIG. 1, it will return to the state shown in FIG. Next, the tripping operation will be explained. If overcurrent flows,
The movable iron piece 28 is activated by the oil dashbot relay 26.
is attracted by electromagnetic force, the Ml shaft 16a at one end of the trip lever 16 is pushed, and the trip lever 16 rotates clockwise about the pin 15. As a result, the hook 14 is disengaged from the lever 16.

The hook 14 is biased by the tensile force of the opening spring 13 and the shaft 1
The movable contact base 5 is rotated counterclockwise around the center 4a, and the movable contact base 5 is pulled up via the lever 11, and the contact with the fixed contact base 4 is removed and the contact is opened. Next, the instantaneous tripping mechanism of the present invention will be explained. When a large current such as a short circuit current flows, the instantaneous tripping movable iron piece (hereinafter referred to as the instantaneous movable iron piece) 19 is attracted to the instantaneous tripping coil 20 by the electromagnetic force generated by the separately installed coil 29. , pin 3 provided for each pole
Rotates counterclockwise around 1. As a result, the repulsion interlocking shaft 23 is disengaged from the instantaneously movable iron piece 19, and at the same time rotates counterclockwise about the rotation fulcrum 23a under the biasing force of the spring 24, the repulsion interlocking shaft 23 One end hits the end 5a of the movable contact base 5 to rotate the movable contact base 5 clockwise around the pin 7 to open the contact. Since the tripping lever 16 also rotates clockwise as the instantaneously movable iron piece 19 rotates counterclockwise, the normal tripping operation due to the overcurrent is also performed in conjunction.

The operation of the repulsion interlocking shaft 23 and the rotation of the movable contact base 5 are performed in the repulsion region until the related end of the multi-polar oil dashbot relay 26 operates, and the related mechanism performs a tripping operation. , the push plate 27 provided at the center pole of the interlocking shaft 8 rotates clockwise together with the interlocking shaft 8, and the repulsion interlocking shaft 2
3, the repulsion interlocking shaft 23 is rotated clockwise to return to the state of engagement with the instantaneously movable iron piece 19 (the state shown in FIG. 1). In this example, the movable contact is used.

Since the movement of the black and white 5 is given by the pushing up force due to the biasing force of the spring 24, it is possible to eliminate the bowing phenomenon of the movable contact base 5.

Other embodiments of the present invention will be described in parts 3 to 5. The end of the instantaneously movable iron piece 19' is connected to the core 20'a, and the core 20'a is attracted by electromagnetic force in the direction of the arrow in FIG.
' b (Fig. 4), and the end 23
'C hits the end 5a of the movable contact base 5 and the movable contact base 5
Open the door to

The spring 24' is a compression spring. Further, the engagement of the latch portion after the pulling operation is such that when the protrusion 14' provided at one end of the hook 14 is rotated by the reset operation, it comes into contact with a part of the repulsion interlocking shaft 23', and the rotation fulcrum 23'a This is done by rotating the repulsion interlocking shaft 23' counterclockwise around .

Still other embodiments of the present invention will be described with reference to FIGS. 6-8. In both of the above embodiments, the instantaneously movable iron piece 19 or 19'
Although a latch part is interposed between the repulsion interlocking shaft 23 or 23', in this embodiment, the movable contact base 5 is directly struck using the suction force of the instantaneously movable iron piece 19#. Therefore, as shown in FIG. 8, the repulsion interlocking shaft 23' has an integral structure.

In addition, the instantaneously movable iron piece 19' is fixed. In Fig. 8, when a short circuit current flows, the momentary movable iron piece 19'' moves to the coil 29.
The repulsion interlocking shaft 23' is attracted by the electromagnetic force generated by the movable contact base 5 and rotates counterclockwise about the rotation fulcrum 23'a, thereby pulling up the movable contact base 5 and opening it. Spring 24 of this embodiment
has a relatively small biasing force and functions to return the repulsion interlocking shaft 23' clockwise. Compared to the above two embodiments, this embodiment does not include a latch part in between, so the time from the occurrence of a short circuit to the opening operation of the movable contact block 5 is quick, and the contact is opened in a state where the arc energy at the time of interruption is small. It is possible to do this. Further, the movement of the repulsion interlocking shaft 23' formed using an insulating material requires only a small force to be applied at all times, so there is an advantage that the movement mechanism is smooth and highly reliable.

Figure 9 (a) is a short-circuit current waveform diagram of each phase at the time of disconnection according to the present invention. The diagram shows the voltage distribution layout at the time of interruption.

(Effects of the Invention) As a result of implementing the present invention, a novel circuit breaker with excellent reliability and breaking performance can be provided due to the following effects.

(a) The contact repulsion operation at the time of short circuit is carried out at the 3rd turn, which allows the pole with the lower current value to complete the cut-off earlier and the other two
By making the pole capable of single-phase interruption, arc current can be reduced and reliable interruption operation can be performed.

(b) Since the multipolar repulsion interlocking mechanism is provided separately from the normal tripping opening/closing mechanism, high reliability is maintained without affecting the ON/OFF operation of the opening/closing operation by impact, frictional force, etc.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the circuit breaker according to the present invention, FIG. 2 is a perspective view of the peripheral part of the repulsion interlocking shaft in FIG. 1,
FIG. 3 is a longitudinal sectional view of another embodiment of the circuit breaker of the present invention;
Figure 4 is a peripheral view of the main parts of the circuit breaker of the embodiment shown in Figure 3;
The figures are FIG. 4, a perspective view related to the repulsion interlocking shaft, FIG. 6, a vertical sectional view showing still another embodiment of the present invention, FIG. 6 is a perspective view of the repulsion interlocking shaft of the embodiment, FIG. 9(a) is a short final current waveform diagram of each phase at the time of interruption of the present invention, and FIG. FIGS. 10(a) and 10(b), which are diagrams showing the voltage distribution arrangement, are diagrams showing the operating states of the main parts of a conventional current-limiting circuit breaker. 19.19', 19''・Movable iron piece 20 for instantaneous release・
・・Core for instantaneous tripping

Claims (1)

[Claims] 1. A fixed contact block and a movable contact block disposed opposite to the fixed contact block are activated prior to the opening operation by the overcurrent tripping means to cause electromagnetic repulsion to the fixed contact block. In the circuit breaker having a configuration in which the movable contact base is opened and opened, the movable contact base is struck via a core for instantaneous tripping and a movable iron piece for instantaneous tripping engaged with the core to open the fixed contact base. A circuit breaker comprising an interlocking repulsion shaft that opens and separates the movable contact block.