JPS6394516A - Circuit breaker - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit breaker, and more particularly to a contact device including a main contact and an arc contact.

[Prior art]

A circuit breaker that has an arc contact in parallel with the main contact opens the arc contact a little N later than the main contact when breaking the circuit, concentrating the current in the circuit on the arc contact and causing the arc to contact the arc. This prevents or reduces the arcing of the main contact by causing the arc to be generated from the arc, prevents the main contact from being damaged by the arc, and brings the arc extinguishing device close to the arc contact to effectively extinguish the arc. is configured to do so.

In such a circuit breaker, the movable main contact and the arc contact are arranged so that the arc contact is located at the end and the main contact is located in the middle on a movable contact device that opens and closes by rotation or translation. It is located in In the most widely used rotary type circuit breakers, this movable contact device is mounted on a rotating arm about a single fixed axis, and the arcing contact has a faster opening speed than the main contact. Although both the and the total separation distances are large, the ratio is basically the same as the ratio of the arm lengths from the axis of rotation to the contact point of each contactor.

In DC circuit breakers and AC current-limiting circuit breakers, the arc energy at the time of breaking consists of a portion converted from electromagnetic energy stored in the circuit and energy supplied from the power source during the arc generation period. This is because the circuit breaker is converted from a fully closed state (no loss state) to a state where an arc is generated and an arc resistance is inserted between the contacts, and this arc resistance rapidly increases due to the arc extinguishing action. (It is thought that the energy generated in this arc resistance is arc energy, and its supply source is 1!-LI2 (L
is the electromagnetic energy stored in the circuit and the energy injected from the power source, which is represented by the inductance and the current flow.

To reduce arc energy, firstly, reduce the breaking current and reduce the electromagnetic energy of the circuit, and secondly, after an arc occurs, increase the arc resistance as quickly as possible to connect the power source to the arc pole. It is necessary to limit the energy supplied. For the former, DC high-speed circuit breakers and AC current-limiting circuit breakers shorten the time it takes for the contacts to start opening, and generate an arc before the short-circuit current rises sufficiently. For the latter purpose, the arc is extended using the electromagnetic force of a blowout coil, but this method requires a large coil, making the device expensive.

A basic method for rapidly increasing arc resistance is to increase the velocity between the contacts. Increasing the contact break rate increases the rate at which the length of the arc column increases, limiting energy injection from the power source and reducing arc energy.

[Problem that the invention seeks to solve]

However, conventional circuit breakers, especially large ones,
Since both the main contact and the arc contact are mounted on a single movable contact device, the moment of inertia is large (the opening speed generated by the cutoff spring is limited. For circuit breakers with rotating contact devices, the arc contact device is mounted at the end of the arm, which is a slight improvement, but there is also a limit to the length of the arm, and this is an innovative method for arc contact devices. There is a drawback that the opening speed of the contacts cannot be increased.Furthermore, even in circuit breakers that move at relatively high speeds, the initial opening speed of the arc contacts is about 2 to 3 ts.

Therefore, the main object of this invention is to significantly increase the opening speed of the primary contact, especially the initial opening speed, in a circuit breaker equipped with a main contact and an arc contact, and to rapidly increase the arc resistance. An object of the present invention is to provide a circuit breaker that reduces arc energy by increasing arc energy.

[Means for solving problems]

The arcing contactor of the circuit breaker according to the present invention is provided with a fixed shaft completely independent from the main contactor, and the movable contactor device impactively contacts the movable arcing contactor device in the vicinity of this fixed shaft when opening. , the movable arc contactor mounted at a distance from the fixed axis is configured to amplify at a ratio corresponding to the arm length ratio.

[For production]

The circuit breaker according to the present invention includes a pair of fixed main contact devices and a movable main contact device, and a pair of fixed arc contact devices and a movable arc contact device, each of which can open and close the movable arc contact devices when disconnecting. In a contact device in which the main contact portion and the arc contact portion are electrically connected in parallel in a closed circuit state and the arc contact is arranged to face the arc extinguishing device, the movable main contact device is biased in the opening direction, the movable arc contactor device being pivotally mounted on a fixed shaft mechanically independent from the movable main contactor device;
The arc contact spring means installed on the movable arc contact device biases the movable arc contact device in the closing direction, and when opening the circuit, the movable main contact device opens first and the main contact portion opens slightly. After that, one end of the main contactor device impacts the vicinity of the fixed shaft of the movable arc contactor device, and an arc contact is formed at one end of the arc contactor device against the biasing force of the arc contactor spring means. The movable arc contactor is opened and opened at high speed especially when the part is cut off, and the arc is initially opened to generate an arc, which is extinguished by an arc extinguishing device, and is characterized in that the distance is increased.

〔Example〕

The structure of one embodiment of the circuit breaker of the present invention will be described in detail below with reference to FIGS. 1 to 7 of the drawings.

As shown in the figure, in the fixed main contact device as an opening/closing contact device, a fixed main contact 2 is mounted on the front side of a fixed side contact base 1, and a fixed terminal conductor 3 is mounted on the back side. In addition, as shown in FIGS. 2 and 3, as a fixed arc contactor device, a screw 5 is attached to the fixed side contact base 1 through an insulator 4.
51, the fixed arc contactor 6 is attached, and from the fixed side contact base 1, one end of the pair of left and right WU-shaped fixed arc contactor connecting conductors 7 is electrically connected with the screw 8, and the other end is connected to the fixed arc contactor 6. It is connected to both sides of the contactor 60. A fixed arc runner 9 is provided to protrude from the center of the fixed arc contact 6. A pair of left and right U-shaped insulating covers 10 are provided to insulate the fixed arc contact connecting conductor 7 from the movable arc contact device A, which will be described later.

The movable side contactor device includes a movable arc contactor device A that is provided so as to protrude from the center, and a movable main contactor device B that is divided and arranged in parallel on both sides of the movable arc contactor device A, and the movable main contactor device B is As shown in FIGS. 2 and 4, two sets of movable main contacts 11 are provided on both sides of the movable arc contact device A at positions corresponding to the fixed main contacts 2. . The movable main contact 11 has a fixed shaft 13 so that the arcuate contact portion 1ja at one end comes into contact with and separates from the fixed main contactor 2, and the arcuate contact portion 11b at the other end maintains contact with the front side of the movable contact base 12 even when opening and closing. It is rotatably supported.

Furthermore, a movable terminal conductor 14 is attached to the back side of the movable contact base 12. One end of a main contact actuating plate 15 is rotatably supported by a shaft 13 integrally with the movable main contact 11 on both sides of each set of movable main contacts 11, and an engaging portion j is provided at the other end.
5a, and a movable main contact holder 16 is provided so as to sandwich the movable main contact 11 and the main contact actuating plate 15.

The movable main contactor holder 16 is rotatably supported by a movable main contactor holder shaft 18 mounted on a fixed frame 17, and a contact spring receiver 19 is attached, and the movable main contactor holder 11 is attached to the contact spring receiver 19. A contact spring 20 is installed between each pair. A striking shaft 21 is attached to one end side of the movable main contact holder 16, and a gap G is formed between it and the engaging portion 15a of the main contact actuating plate 15.
1, and a spring rack fixed to the striking shaft 21 and the fixed frame 17 has a cutoff spring 23 installed between the shaft 22 and biases the movable main contact holder 16 in the opening direction. . Further, a stopper roller 24 and a trip roller 25 are mounted on the other side of the main contact holder 16.

Referring to FIGS. 2 and 3, the movable arc contact device A is mounted on a movable arc contact base 27 so that the movable arc contact 26 protrudes forward from the movable main contact 11 and corresponds to the fixed arc contact 6. It will be installed. One end of a flexible conductor 28 is connected to the bent lower end 27 a of the movable arc contact base 27 , and the other end of the flexible conductor 28 is connected to a fixed conductor 29 electrically connected to the movable contact base 12 . It is connected to the.

The movable arc contact base 27 is the movable arc contact holder 6
Furthermore, the movable arc contact holder 30 is provided so as to rotate about a fixed shaft 61 of the movable arc contact device as a fulcrum. Further, the movable arc contact holder 30 is formed in a KJ shape, and has a first engagement edge 30a and a second engagement edge 30b of the striking shaft 21 of the movable main contact holder 16 on the inner edge of the hook portion. It is provided in a cam shape.

Further, the spring rack provided at the other end of the movable arc contact holder 30 has a movable arc contact spring 34 installed between the shaft 32 and the fixed shaft 63 provided on the fixed frame 17.
The movable arc contactor 26 is always biased in the closing direction to create a gap G between the engagement groove edge 30a of the movable arc contactor holder 30 and the striking shaft 21 mounted on the movable main contactor holder 16.
2. Further, an arc extinguishing device 65 is disposed above the arc contact portions 6, 26. The arc extinguishing device 55 has a large number of arc extinguishing grids 36 each having a V-shaped notch made of a well-known magnetic plate and mounted within an arc extinguishing chamber cover made of a molded insulator.

As shown in FIGS. 1 and 2, the movable main contact holder shaft 18 is provided so as to be able to slide inside the elongated hole 67 of the fixed frame 17, and is pivoted on the movable main contact holder shaft 18. The attached connecting plate 38 is connected via an embedded metal fitting 39 to an operating iron 40 made of a six-pole molded insulator. The operating rod 40 is opened and closed by a well-known opening and closing mechanism (not shown). Trip roller 2 provided at one end of the movable main contactor holder 16
5 is a hook portion 41 provided at one end of the hook lever 41;
It is normally engaged and held by a. hook lever 41
is rotatably supported at the center by a hook lever shaft 42, and the other end 41b receives a biasing force in the clockwise direction by a hook lever spring 45 so as to correspond to a trip interlocking shaft 44 provided integrally with the trip operating plate 43. Is receiving. Also,
As shown in FIG. S, the trip actuating plate 46 has an arm commonly rotatably supported by the hook lever shaft 42, and a return spring 46 is installed between the trip actuating plate 43 and the fixed frame member 47. . This fixed frame member 47 is formed integrally with a hook lever bearing 47a.

As shown in FIGS. 2 and 3, the lower end of the fixed frame 17 in the center of the movable contactor device is provided with a trip roller 25 provided on the movable main contactor holder 16, one end of which corresponds. A trip interlock lever 49 is provided.

The trip linking lever 49 is made of an insulating material, is rotatably supported by a shaft 48 installed on the fixed frame 17, and has the other end connected to one end of the trip link 50. Also,
The other end of the trip link 50 is operatively connected to an opening/closing operation mechanism (not shown) provided on the front side of the circuit breaker. Further, the lower end of the fixed frame 17 at the center is supported by a reinforcing frame member 51, and this reinforcing frame member 51 is attached to a mounting base 52 attached to the movable contact base 12 by screws 56 together with the fixed frame member 47. installed. Additionally, an impact tripping device 54 is provided corresponding to the trip operating plate 43.
A trip actuation rod 55 is correspondingly provided with a head 55a made of an insulating material. This shock tripping device 5
Reference numeral 4 is composed of an electromagnet, and is provided so that a trip actuation rod 55 projects when an overcurrent or other tripping signal is applied to the excitation coil.

Next, the operation of the circuit breaker of the present invention described above will be explained.
When an overcurrent flows in the closed circuit state shown in FIGS. 3 and 4 and a trip signal is applied to the excitation coil of the shock trip device 54, the trip actuating rod 55 rotates the trip actuating plate 43. The trip roller 25 attached to one end of the movable main contactor holder 16 and the hook lever 41 are moved by pushing up one end of the hook lever 41 via the trip interlocking shaft 44 and rotating the hook lever 41 counterclockwise. is released, the movable main contact holder 16 is rotated counterclockwise by the isolation spring 23 using the movable main contact holder shaft 18 as a fulcrum, and the striking shaft 21 is rotated by the gap G and the main The movable main contact 11 starts rotating around the shaft 16 from the moment it engages with the stop portion 15a of the contact actuation plate 15.
When the arcuate contact portion 11a is slightly separated from the fixed main contact 2, that is, when the striking shaft 21 is moved from the starting position to the gap G in FIG.
2, the striking shaft 21 collides with the first engagement groove edge 30a of the movable arc contact holder 30, and the movable arc contact holder 60 uses the shaft 61 as a fulcrum against the movable arc contact spring 64. As a result, the movable arc contact 26 rapidly rotates counterclockwise, and the movable arc contact 26 separates from the fixed arc contact 6 at a high speed, and the movable main contact holder 16 further rotates and the striking shaft 2
1 is the first engagement of the movable arc contact holder 30 ≠ the edge 30
The side edge of the movable main contact holder 160 comes into contact with the fixed shaft 36 of the fixed frame 17 and stops, and the movable arc contact holder 30 is brought into movable arc contact in the open position. The rotation in the circuit closing direction by the child spring 34 is prevented by the engagement of the second engagement edge 301) with the striking shaft 21, and the movable arc contact 26 is held in the open circuit position in the trip state shown in FIG. Become. In this case, the second relationship 3
0b constitutes a cam surface that hardly moves the movable arc contactor device A with respect to the latter half movement of the striking shaft 21.

At this time, the stopper roller 24 provided at the other end of the movable main contactor holder 16 is attached to the mounting base 52 of the reinforcing frame member 51.
The movable main contact holder 16 absorbs the impact force received by the movable main contact holder 16 by colliding with a buffer plate 56 made of an elastic material mounted on the front side of the movable main contact holder 16.

- 10,000, the trip roller 25 at one end of the movable main contact holder 16 is disengaged from the hook lever 41, and the trip roller 25 moves the trip interlocking lever 49 by counterclockwise rotation of the movable main contact holder 16. It rotates clockwise to collapse the opening/closing operating device groove via the trip link 50, and acts to pull up the operating rod 40 connected thereto. Due to this lifting action of the operating rod 40, the movable main contact holder shaft 18, which is integrated with the connecting plate 38, slides within the elongated hole 37 of the fixed frame 17, and the movable main contact holder 16 is swung clockwise, so that the stopper Roller 24 and trip roller 25 are moved. At this time, the tripping signal applied to the excitation coil of the shock tripping device is cut off, the tripping actuating rod 55 has returned to its original position, and the hook lever 41 is moved to the hook lever by the movement of the trip roller 25 described above. The trip roller 25 and the hook portion 41a of the hook lever 41 are rotated clockwise by the spring 45, and the other end 411) of the hook lever 41 is rotated clockwise by the trip interlocking shaft 44 when the corresponding circuit breaker is opened. The reset state shown in FIG. 6 is reached.

In the circuit breaker of the present invention constructed as described above, the movable arc contact 26 is mounted on the fixed frame 17, and mounted on the movable arc contact holder 30 which is pivotally supported on the fixed shaft 31 which is completely independent of the movable main contact 11. In the vicinity of the fixed shaft 31, where the striking shaft 21 of the movable main contactor device B becomes the rotation fulcrum of the movable arc contactor holder 300 when the movable main contactor device B is opened.
The movable arc contact 2 acts on the movable arc contact holder 30 in a perpulsive manner and is mounted at a distance from the fixed shaft 31.
6 and the distance from the fixed shaft 31 to the point of collision of the striking shaft 21 with the movable arc contactor holder 60. , the initial separation distance between the movable arc contact 26 and the fixed arc contact 6 is increased.

Moreover, since the movable arc contactor 26 does not have the inertia of the movable main contactor 11, it is easy to increase the initial opening speed. Furthermore, by appropriately selecting the second engaging edge 30b, the full opening angle of the movable arc contactor device A can be set freely regardless of its initial opening speed, so that the required breaking distance can be obtained and Excessive displacement of the movable arc contact device A can be prevented. The movable arc contact device A can be configured as a device with a low moment of inertia that is independent of the movable main contact 11 and the movable main contact holder 16, so the rotational momentum of the relatively large movable main contact device B can be reduced. It is easy to dramatically increase the initial opening speed in response to impact compared to conventional devices.

Furthermore, even if the movable main contact device starts to separate, the shaft 31 that serves as the rotational fulcrum of the movable arc contact holder 30 is completely independent, so the striking shaft 21 of the movable main contact device mentioned above will continue to make contact with the movable arc. Until a collision occurs with the child holder 30, there is no mechanical relationship with each other. When the device is started, the movable arc contactor 26 swings, causing incomplete contact or undesirable early separation;
Current concentration on the arc contactor is no longer hindered.

In addition, the movable arc contactor 26 has a point at which it collides with the movable arc contactor holder 60 of the movable main contactor device with respect to the axis 31 serving as a rotation fulcrum, and a length of the arm of the contact turret of the movable arc contactor 26. Since the ratio of the heights can be selected relatively freely, it is possible to set the width ratio of the arm of the movable arc contactor 26 to a preferable value in consideration of assembly accuracy.

〔Effect of the invention〕

As described above, according to the present invention, the movable arc contactor 26
The shaft 31, which serves as the 0-rotation fulcrum, is made independent from the movable main contactor device, and the opening speed of the movable main contactor is increased by the width increasing mechanism of the arm, thereby converting it into a movable arc contactor. After accelerating the movable main contact device with a large moment of inertia by the cutoff spring 26 and separating it by a distance that does not cause an arc to occur due to the voltage between the terminals of the arcing contact while it is energized, for example, about one cycle, the movable main contact device The relatively large momentum of the device acts impulsively on the movable arc contactor with a relatively small moment of inertia, increasing the initial opening speed of the movable arc contactor and rapidly increasing the initial arc resistance; This has the effect of sufficiently limiting the energy supplied from the

[Brief explanation of the drawing]

[Embodiment of the Invention] Figures 1 to 7 are diagrams showing an embodiment of the circuit breaker of the present invention, and Figure 1 is a side view of the center cross section with a part of the circuit breaker showing the closed circuit state omitted. Fig. 2 is a plan view of the main part of the movable contact device, Fig. 3 is a side sectional view of the main part showing the closed circuit state as seen from the direction of the arrow at the central part of Fig. 2 + nm line, and Fig. 4 is the same. The main part side when looking at the IV-IV line of the second cause from the direction of the arrow @
Figure 5 is a side sectional view of the main part showing the trip state, Figure 6 is a side view.
The figure is a sectional side view of the main part showing the reset state, and FIG. 7 is a perspective view of the main part of the contact device. In the figure, A: Movable arc contact device, B: Movable main contact device, 1: Fixed side contact base, 2: Fixed main contact, 6: Fixed terminal conductor, 4
... Insulator, 6. Fixed arc contact, 7. Fixed arc contact connecting conductor, 9. Fixed side arc runner, 10.
- Insulation cover, 11... Movable main contact, 12... Movable side contact base, 14... Movable side terminal conductor, 15... Main contact actuation plate, 16... Movable main contact l ruler, 17・Fixed frame, 20
・・Contact spring, 21・・Tapping shaft, 23・・
Shutoff spring, 24... Stopper roller, 25...
・Trip roller, 26...Movable arc contactor, 27
・・Movable arc contact base, 30・・Movable arc contact holder, 34・・Movable arc contact spring, 65・・Arc extinguishing device, 36・・Arc extinguishing grid, 38・・Connecting plate, 40・・
- Operating rod, 41... Hook lever, 43... Operating plate, 44... Trip interlocking shaft, 45... Hook lever spring, 49... Trip interlocking lever, 50... Trip link, 51... Reinforcement frame member , 52... Mounting base, 54... Thrust removal device, 55... Trip operation rod, 56... Buffer plate.

Claims (1)

[Claims] 1. It has a pair of fixed main contact devices and a movable main contact device, each of which can be opened and closed, and a pair of fixed arc contact devices and a movable arc contact device, and the main contact part and the arc contact part are electrically connected in the closed circuit state. In the contactor device, the movable main contactor device is biased in the opening direction by a cutoff spring, and the movable main contactor device is biased in the opening direction by a cutoff spring, and the movable main contactor device is The contactor device is pivotally mounted on a fixed shaft mechanically independent from the movable main contactor device, and arc contactor spring means installed on the movable arc contactor device biases the movable arc contactor device in a closing direction. However, when the circuit is opened, the movable main contact device opens first, and after the main contact part opens slightly, one end of the main contact device is moved near the fixed shaft of the movable arc contact device. The arc contact portion formed at one end of the arc contact device is rapidly separated against the biasing force of the arc contact spring means to generate an arc, which is extinguished by an arc extinguishing device. A circuit breaker characterized by an arc.