CN1082236C

CN1082236C - Current-limiting apparatus

Info

Publication number: CN1082236C
Application number: CN98109281A
Authority: CN
Inventors: 浅川浩司; 小山淳; 内田直司
Original assignee: Fuji Electric Co Ltd
Current assignee: Fuji Electric FA Components and Systems Co Ltd; Fuji Electric Assets Management Co Ltd
Priority date: 1997-06-12
Filing date: 1998-05-20
Publication date: 2002-04-03
Anticipated expiration: 2018-05-20
Also published as: CN1202717A; TW391558U; JPH117869A; JP3206729B2

Abstract

The invention dispenses with a flexible conductor for electrically connecting a movable contact element and a fixed conductor part which are separated by an electromagnetic repulsive force when a heavy current is carried. The parallel conductor parts of a fixed contact 1 and a movable contact 7 are separated with a connecting pin as a fulcrum against a return spring 12 by an electromagnetic repulsive force based on a current I. The movable contact 7 is nipped by a forked connecting conductor 9, and pressed from both sides by a pair of contact springs 10 installed in the connecting pin, whereby the movable contact 7 is brought into slide contact with the connecting conductor 9 in such a manner as to be rotatable. Since the electric connection between the movable contact 7 and the connecting conductor 9 is performed by the slide contact without depending on a flexible conductor, the housing space of the flexible conductor within a case 17 is dispensed with, and a current- limiting device can be miniaturized.

Description

Current-limiting apparatus

The present invention relates to a kind of with as the current-limiting apparatus of a kind of circuit breaker (circuit brake) of Inturruptor for sub-line polyphone.

Japanese Patent Application Publication 3-102724 has disclosed a kind of like this current-limiting apparatus.Fig. 6 to 8 has represented this device.

One is incorporated into an arc extinguishing grid 37 that is used for each insulator container 38 mutually with the current-limiting apparatus 31 of a circuit breaker (circuit brake) 30 connections by fixedly contact shoes 33, movable contact shoes 35, terminals 36 and by a movable contact 34 that contacts with fixed contact 32 by a fixed contact 32 forms.Integral body is formed with another terminals 39 on fixing contact shoes 33, and these terminals are closely attached on terminals 40 of a circuit breaker (circuit brake) 30.Movable contact shoes 35 be supported in rotationally on the pin 41 and by a spring 42 in the counterclockwise direction the (see figure 6) pressurization so that movable contact 34 is pressed against fixed contact 32.Movable contact shoes 35 and terminals 36 are linked together by a flexible conductor 43.

In Fig. 6, when closing of power circuit breaker, an electric current then flows through the inside of this device 31 and circuit breaker 30 by the terminals 36 of this current-limiting apparatus, and flows out from the terminals 44 of circuit breaker 30.In this case, as make electric current surpass a suitable definite value owing to being short-circuited, again because between fixed and

movable contact

32 and 34 and the opposite electromagnetic force of direction that produces between flowing through respectively fixed and

movable contact shoes

33 and 35 the electric current I, the pressure of movable contact shoes 35 resistance springs 42 leaves fixedly contact shoes 33, causes and produce an electric arc A between contact 32 and 34.The arc voltage of an electric arc of generation is superimposed similarly between the contact (not shown) fixing and an activity of one on this circuit breaker 30 from the arc voltage of this electric arc A and from one, and synthetic high arc voltage has limited the electric current that cuts off circuit.

In such conventional apparatus, be that the movable contact shoes 35 of a movable part is coupled to each other by the flexible conductor of being made up of all copper cash that reverses 43 with the terminals 36 that are a standing part and is in the same place.This flexible conductor 43 moves when movable contact shoes 35 leaves fixedly contact shoes, and has one with respect to the bigger external diameter of its conduction cross section, so requirement has a large space holding lead, thereby has limited the miniaturization of this current-limiting apparatus 31.

A purpose of the present invention is, in order to impel the miniaturization of this current-limiting apparatus, dwindle the space that connects between movable contact shoes and the standing part.

The present invention seeks to by movable contact shoes and standing part sliding contact in case between exempt to realize with flexible conductor.In other words, a current-limiting apparatus that all is installed in the insulating vessel for each phase place comprises: a fixing contact shoes, and it has the terminals that an at one end connected fixed contact and forms at the other end; One movable contact shoes, it is parallel to a conductor part of the fixedly contact shoes that combines with fixed contact, at the one end one sliding contact that contacts with fixed contact is arranged; One connects conductor, and its sliding contact is in the other end of movable contact shoes; One connecting pin, it passes and connects conductor and movable contact shoes so that movable contact shoes is supported on rotationally connects on the conductor; One contact spring, it applies a contact pressure between movable contact shoes and the sliding contact surface that connects conductor; One back-moving spring, it uses connecting pin as a strong point movable contact shoes to be pressed to fixedly contact shoes; And, another terminals, it is connected in the connection conductor.

In this current-limiting apparatus, preferably a dihedral starting the arc part is installed in by this way with connect the terminals that conductor combines on, even this angle-shaped piece is with relative with the conductor part of the fixedly contact shoes of fixed contact combination.So the pin of the movable contact shoes side of the electric arc that produces when movable contact shoes leaves fixing contact shoes can move on on the starting the arc angle-shaped piece, a current bypass is flowed through activity contact shoes and connect the contact surface of conductor, in case this part is impaired.

In this current-limiting apparatus, preferably arc control device are installed to such an extent that be parallel to fixing and the slip contact shoes.A plurality of arc extinguishing grids are housed in these arc control device, and each arc extinguishing grid is a U-shaped magnetic sheet, and these plates are parallel to each other to separate one at interval, and makes them surround fixed and movable contact shoes.

In in these current-limiting apparatus any one, be preferably in movable contact shoes and connect the silver composite coating that plates silvering on one or two sliding contact surface of conductor or in silvering, be mixed with lubricated grain.Contain the silver composite coating of lubricated grain (as carbon granules) fully by plating, this structure can reduce the contact resistance on all sliding contacts surface, and can improve the sliding on all sliding contacts surface.

Find out from above-mentioned: the present invention does not need flexible conductor having dwindled this current-limiting apparatus, thus prevented the variation of current limiting characteristic or in flexible conductor because it acts on the open circuit that the resistance to bending on the movable contact shoes causes.Therefore, improved the reliability of this current-limiting apparatus.

Fig. 1 is a vertical cross-section view of a current-limiting apparatus of expression one embodiment of the invention;

Fig. 2 is the vertical view that the part of the insulating vessel among Fig. 1 is broken away;

Fig. 3 is a fixedly end view that amplifies of contact shoes and a movable contact shoes of one among Fig. 1;

Fig. 4 is the vertical view of Fig. 3;

Fig. 5 has represented the arcing chamber among Fig. 1; Fig. 5 (A) is that an end view and Fig. 5 (B) are right views;

Fig. 6 is a vertical sectional view of a traditional current-limiting apparatus;

Fig. 7 is the fixing stereogram with a contact shoes activity of one among Fig. 6;

Fig. 8 is the end view of Fig. 7.

One embodiment of this invention of implementing in a three-phase current-limiting apparatus has been described in conjunction with Fig. 1 to 5.Fig. 1 is a vertical cross-section view of this current-limiting apparatus; Fig. 2 is the vertical view that the part of expression one insulating vessel inside is broken away; Fig. 3 is the fixing end view that amplifies with a contact shoes activity of one among Fig. 1; Fig. 4 is the vertical view of Fig. 3; Fig. 5 (A) is an end view of the arcing chamber among Fig. 1; And Fig. 5 (B) is the right view of Fig. 5 (A).In Fig. 3 and 4, fixing contact shoes 1 is L-shaped, and have a brazing on the one pin fixed contact 2 and on its another pin, be formed with terminals 3.These terminals 3 have a screwed hole 4 and a pair of confession two hold-down screws that are screwed in it for a terminal screw (not shown) to be screwed into its interior horizontal thread hole 5.

One has parallel fixing that pin of contact shoes 1 that a fixed contact is installed thereon of the movable contact shoes 7 of the movable contact 6 of a brazing on the one pin.The other end of movable contact shoes 7 is connected in one rotationally by a connecting pin 8 and connects conductor 9.This connection conductor 9 is crooked and is configured as fork-shaped, makes and can establish a pair of transverse arm, and this picks up the other end of movable contact shoes 7 come and be contacted with slidably the sidepiece (as shown in Figure 4) of movable contact shoes 7 to transverse arm.The every pair of contact spring 10 that is become by the spirality compression spring set that is fixed on the connecting pin 8 is positioned on every side of each arm of the connection conductor 9 of clamping movable contact shoes 7.Have the connecting pin 8 of a socket cap at its other end one threaded portion to be arranged at the one end, this other end passes movable contact shoes 7 and stretches out with connecting conductor 9.One has to be screwed on the threaded portion with the spring compression device 11 of the identical diameter of the socket cap of connecting pin and is pressed in movable contact shoes 7 so that compression contact spring 10 will connect all arms of conductor 9, thereby suitable contact pressure is put on all sliding contacts surface.Be distributed in film plating that the synthetic material that forms in the money base matter (silver matrix) makes in the both sides of movable contact shoes 7 with connect on all inner surfaces of all arms of conductor 9 by a kind of carbon granules wherein, make each side of movable contact shoes be contacted with the inner surface that connects conductor 9 slidably.

Movable contact shoes 7 utilizes a connecting pin 8 to be pressurizeed towards fixing contact shoes 1 by a back-moving spring 12 as a strong point, so that movable contact 6 is pressed against fixed contact 2.Back-moving spring 12 is made up of a pair of torsion-coil spring, and it is fixing and keep to be connected the head of pin 8 and spring compression spare 11 at a spiral part of every end of this spring.U-shaped pin in this one of back-moving spring 12 is shelved on the movable contact shoes 7, and its right and left foot is shelved on the connection conductor 9 to reach required elastic torque.Another terminals 13 pass through its L shaped pin brazing in connecting terminals 9.The horizontal thread hole 15 that terminals 13 have a screwed hole 14 that is screwed into for a terminal screw (not shown) and all hold-down screws of a pair of confession to be screwed into.In addition, arc angle-shaped piece 16 is installed on the terminals 13 together, makes with relative with the pin of the fixedly contact shoes 1 that links together of fixed contact 2.By a protuberance that forms from the extruding of the rear side of terminals 13 being inserted the hole on starting the arc angle-shaped piece 16, to the method for the point caulking joint of this protuberance, this starting the arc angle-shaped piece 16 is fixed then.

As illustrated in fig. 1 and 2, the fixing contact shoes with activity of three phase places is contained in the insulating vessel.The insulating vessel that is molded into moulding resin is made up of a housing 17 and a lid 18 and is divided into three parallel cells with all alternate next doors (inter-phase partition wall).Fixing each phase place with contact shoes activity is all inserted in this housing 17, and fixedly contact shoes 1 and terminals 13 use the

mounting screw

19 and 20 rear sides from housing 17 that are screwed into screwed hole 5 and 15 to be fixed.Then, install one and the arc control device 22 of a plurality of arc extinguishing grids 21 are housed in it, and require to install to such an extent that not only make these arc control device surround fixing and contact shoes activity, and make all arc extinguishing grids 21 be parallel to contact shoes 1 fixing and activity and 7.Each arc extinguishing grid 21 wherein is U-shaped magnetic sheets, and these plates are parallel to each other to separate one at interval.

At last, lid 18 being put on the housing 17 and being screwed into the screwed hole 23 interior screws 24 that are located on each left and right sidewall with one covers its tight.As shown in Figure 5, in arc control device 22, all arc extinguishing grids 21 utilize the method for caulking joint to be fixed on a pair of lateral isolation sidewall 25 by the horizontal plush copper 21a of one.Arc control device 22 are supported by the method that its sidewall 25 is placed on the step (not shown) that forms on the sidewall of the housing 17 and alternate next door, and use and cover 18 it is fixed.In the current-limiting apparatus shown in Fig. 1 and 2, terminals 13 use screwed hole 4 to be connected in supply side terminals of a circuit breaker (not shown), and use this screwed hole 4 that a supply side external conductor is tightened against terminals 3.When closing of power circuit breaker, electric current I is passed through the fixedly supply side of contact shoes 1, fixed and

movable contact

2 and 6, movable contact shoes 7, connection conductor 9 and terminals 13 inflow circuit breakers from terminals 3, after flowing through circuit breaker, flow into a load (as shown in Figure 1) from its load-side terminals.

When the electric current I by this current-limiting apparatus surpasses a setting, because between fixed and

movable contact

2 and 6 and the magnetic reaction force between the electric current of all parallel conductor part of flowing through the other way around fixed and

movable contact shoes

1 and 7, the elastic force of movable contact shoes 7 resistance back-moving springs 12 leaves fixedly contact shoes (shown in the chain-dotted line among Fig. 3), to produce an electric arc 26 between this fixed and movable contact shoes 2 and 6.In Fig. 3, this electric arc 26 is by by the fixedly upwards driving of magnetic flux phi of the electric current I of contact shoes 1, and the pin of this electric arc 26 moves on on the point of fixing contact shoes 1 and the starting the arc angle-shaped piece 16 (shown in dotted line).In Fig. 1, this electric arc 26 is drawn again and is crossed all arc extinguishing grids 21, is cooled then and is divided into all electric arc between all arc extinguishing grids, thereby increased arc voltage.This arc voltage is superimposed upon on the arc voltage that produces in circuit breaker simultaneously, has limited electric current I thus and has disconnected circuit, and needn't wait for the tripping of circuit breaker.

Be to obtain as the movable contact shoes 7 of a movable part with the electric current between the conductor 9 of connecting by its sliding contact between two as a standing part, therefore, this current-limiting apparatus does not need flexible conductor, thereby avoided the above-mentioned relevant shortcoming of using flexible conductor, promptly have with respect to of the requirement of its conductors cross, thereby this current-limiting apparatus is dwindled for the mobile required space of a kind of flexible conductor of bigger external diameter to being adapted to.In addition, owing to install starting the arc angle-shaped piece 16 to such an extent that the pin at the electric arc 26 of movable contact shoes 7 one sides is moved on on the starting the arc angle-shaped piece 16 earlier, thereby make electric current I switch to movable contact shoes 7 and connect on the conductor 9.So, limit electric current and flow through all sliding contacts required time of surface, reduced the infringement that causes by big electric current to all sliding contacts surface.In addition, arc control device 22 are installed to such an extent that help arc extinguishing so that further reduced circuit opening time.In illustrated embodiment, connecting conductor 9 can make with terminals 13 integral body.

Claims

1. a current-limiting apparatus is characterized in that, a current-limiting apparatus that all is installed in the insulating vessel for each phase place comprises: a fixing contact shoes, and it has the terminals that an at one end connected fixed contact and forms at the other end; One movable contact shoes, the conductor that it is parallel to the fixedly contact shoes that combines with described fixed contact all divides, and at the one end one sliding contact that contacts with described fixed contact is arranged; One connects conductor, and its sliding contact is in the other end of movable contact shoes; One connecting pin, it passes and connects conductor and described movable contact shoes so that movable contact shoes is supported on the described connection conductor rotationally; One contact spring, it applies a contact force between described movable contact shoes and the sliding contact surface that connects conductor; One back-moving spring, it uses described connecting pin as a strong point described movable contact shoes to be pressed to described fixedly contact shoes; And, another terminals, it is connected in described connection conductor.

2. current-limiting apparatus as claimed in claim 1 is characterized in that, with arc angle-shaped piece together be installed in by this way with connect the terminals that conductor combines on, even this angle-shaped piece is with relative with the conductor part of the fixedly contact shoes of fixed contact combination.

3. current-limiting apparatus as claimed in claim 2 is characterized in that, installs arc control device to such an extent that be parallel to fixing and the slip contact shoes.A plurality of arc extinguishing grids are housed in these arc control device, and each arc extinguishing grid is a U-shaped magnetic sheet, and these plates are parallel to each other to separate one at interval, and makes them surround fixed and movable contact shoes.

4. as each described current-limiting apparatus in the claim 1 to 3, it is characterized in that, on one or two sliding contact surface of movable contact shoes and connection conductor, plate silvering or in silvering, be mixed with the silver composite coating that lubricates grain.