CN202189744U

CN202189744U - Device for preventing moving contact of moulded case circuit breaker from falling

Info

Publication number: CN202189744U
Application number: CN2011202869954U
Authority: CN
Inventors: 赵汉新; 赵敏海
Original assignee: Wuxi Sahat Electrical Co Ltd
Current assignee: Wuxi Sahat Electrical Co Ltd
Priority date: 2011-08-09
Filing date: 2011-08-09
Publication date: 2012-04-11
Anticipated expiration: 2021-08-09

Abstract

The utility model discloses a device for preventing a moving contact of a moulded case circuit breaker from falling, which comprises a contact rotating shaft and a moving contact that is arranged in an inner chamber of the contact rotating shaft and capable of rotating around the center of the contact rotating shaft, the lower edge of the moving contact is provided with a cam surface, a shaft pin is fixedly on the contact rotating shaft, two contact springs are arranged on the shaft pin by taking the moving contact as a center, one end of each contact spring is a fixed end which is connected on the shaft pin, the other end of each contact spring is a moving end which is connected with a moving shaft pin, and the moving shaft pin is arranged in a chute arranged on the contact rotating shaft and props against the cam surface all the time under the action of the contact springs. For the device for preventing the moving contact of the moulded case circuit breaker from falling, when fault current flows through the circuit breaker, the moving contact overcomes the counter-force of the contact springs to be expelled away, so that the acting force of the contact springs is in the expelling direction of the contact finally, and the phenomenon of falling of the moving contact in disjunction can be effectively prevented; furthermore, the quick disjunction can be realized, and the disjunction capability of the circuit breaker is enhanced.

Description

The dropproof device of breaker of plastic casing moving contact

Technical field

The utility model relates to a kind of breaker of plastic casing moving contact, relates in particular to the dropproof device of a kind of breaker of plastic casing moving contact.

Background technology

In the contact system of breaker of plastic casing; Always include one or one group of touch spring producing the contact pressure between the dynamic and static contact, thereby to guarantee that contact has when the closure enough contact pressures to make the resistance of contact point be small enough to make the Secure Application that guarantees circuit breaker within the scope of temperature rise at national Specification of circuit breaker.

At present, breaker of plastic casing is as the branch stage distribution apparatus of distribution system, and along with the continuous increase of net capacity and the needs of centralized power distribution, its breaking capacity of system requirements is increasingly high, so the extensive use in breaker of plastic casing of current-limiting type structure of contact terminal.Yet the power of scolding out of its contact of current-limiting type structure of contact terminal is the electric current that depends on by between this contact; Promptly when current value increases to certain value; Moving; Static contact begins to scold out under the effect in that loop electric power and node are electrodynamic simultaneously; The cycle variation of quick increase of the resistance between contact at this moment and alternating current can cause the electric current alpine rush or palm-bark rain cape of before breaker cut-offs, flowing through between contact to reduce to electric power less than moving; Scold out the situation of power between static contact; At this moment; The contact of before being scolded out is along with electrodynamic minimizing will be moved to the closing position direction from scolding open position; Promptly cause so-called contact to fall phenomenon, contact falls and can cause restriking of electric arc between contact and fault current can not be cut-off.

The utility model content

To the problems referred to above, the purpose of the utility model is to provide a kind of breaker of plastic casing moving contact dropproof device, and it can effectively prevent the moving contact phenomenon that contact falls in breaking course, realizes quick disjunction; Improved the breaking capacity of circuit breaker.

The purpose of the utility model is to realize through following technical scheme:

The dropproof device of a kind of breaker of plastic casing moving contact; It comprises the contact rotating shaft and is installed on the inner chamber of contact rotating shaft and the moving contact that can rotate around contact rotating shaft center that wherein, the lower edge of said moving contact is provided with cam surface; Be fixed with pivot pin in the said contact rotating shaft; Be that the center is equipped with two touch springs with the moving contact on the said pivot pin, an end of said touch spring is that stiff end is connected on the pivot pin, and the other end is that movable end connects and moves pivot pin; Said mobile pivot pin is installed in the chute of offering in the contact rotating shaft, and under the active force of touch spring, is pressed on the cam surface all the time.

Especially, have groove in the both sides of cam surface on the said moving contact.

Especially, said cam surface is that the boundary is divided into leading portion stroke and back segment stroke with the summit, and the gradient of said back segment stroke is greater than the gradient of leading portion stroke.

The beneficial effect of the utility model does; The moving contact of the dropproof device of said breaker of plastic casing moving contact passes to the rated current of breaker under closure state; The line of action of touch spring power is positioned at the outside at contact contact point and contact rotating shaft center, and the direction of its moment makes the contact point of contact produce operating pressure; And when fault current is flowed through breaker; Moving; Static contact overcomes the touch spring counter-force under loop electric power and the electrodynamic effect simultaneously of node begins to scold out; The direction that finally makes the touch spring active force is by contact rotating shaft center and between moving contact contact and contact rotating shaft center; This moment touch spring active force be in contact scold evolution to; Even fault current is reduced to electrodynamic repulsion force less than the touch spring counter-force because of certain reason alpine rush or palm-bark rain cape, also can moving contact be remained on and scold open position and make contact continue can not fall to breaking off the direction motion because of the variation of touch spring counter-force direction.Can effectively prevent the moving contact phenomenon that contact falls in breaking course; And can realize quick disjunction; Improved the breaking capacity of circuit breaker.

Description of drawings

According to accompanying drawing and embodiment the utility model is done further explain below.

Fig. 1 is the structural representation of the dropproof device of the utility model breaker of plastic casing moving contact;

Fig. 2 is the profile of the moving contact of the dropproof device of the utility model breaker of plastic casing moving contact;

Fig. 3 is in the sketch map of closure state for the dropproof device of the utility model breaker of plastic casing moving contact;

Fig. 4 scolds the sketch map in the open procedure for the dropproof device of the utility model breaker of plastic casing moving contact at moving contact;

Fig. 5 is in the sketch map of scolding out state for the dropproof device of the utility model breaker of plastic casing moving contact.

Among the figure:

1, contact rotating shaft; 2, moving contact; 20, cam surface; 21, installing hole; 22, leading portion stroke; 23, back segment stroke; 24, groove; 3, contact bearing pin; 4, pivot pin; 5, touch spring; 6, chute; 7, move pivot pin.

Embodiment

Please with reference to Fig. 1 and shown in Figure 3, in present embodiment, the dropproof device of a kind of breaker of plastic casing moving contact comprises the contact rotating shaft 1 with inner chamber; The center of said contact rotating shaft 1 is equipped with contact pivot pin 3; Offer installing hole 21 on the said moving contact 2, moving contact is installed on the contact pivot pin 3, and can rotate around the center of contact rotating shaft 1 through installing hole 21; Said moving contact 2 is arranged in the inner chamber of contact rotating shaft 1; Moving contact 2 stretches out outside the inner chamber of contact rotating shaft 1 with the contact of corresponding fixed contact (not illustrating among the figure) contact, and the lower edge of said moving contact 2 is provided with cam surface 20, has groove 24 in the both sides of cam surface 20 on the said moving contact 2.

Also be fixed with pivot pin 4 in the said contact rotating shaft 1; Be that the center is equipped with two touch springs 5 with moving contact 2 on the said pivot pin 4; One end of said touch spring 5 is that stiff end is connected on the pivot pin 4, and the other end is that movable end connects mobile pivot pin 7, and said mobile pivot pin 7 is installed in the chute of offering in the contact rotating shaft 16; Chute 6 moves said mobile pivot pin 7 in the drive lower edge of touch spring 5, and is being pressed over all the time on the cam surface 20 under the active force of touch spring 5.

Said cam surface 20 is that the boundary is divided into leading portion stroke 22 and back segment stroke 23 with the summit; The gradient of said back segment stroke 23 is greater than the gradient of leading portion stroke 22; So that when moving pivot pin 7 and crossing the summit of cam surface 20, can under the effect of touch spring 5, fall into fast in the groove 24 of back segment stroke 23 1 sides.

See also Fig. 3 to shown in Figure 5; During operate as normal; The moving contact 2 of the dropproof device of said breaker of plastic casing moving contact passes to the rated current of breaker under closure state; The line of action of touch spring 3 is positioned at the outside at moving contact 2 contact points and contact rotating shaft 1 center, and the direction of its moment makes the contact point of contact produce operating pressure; And when fault current is flowed through breaker; Moving contact 2 and static contact (not illustrating among the figure) overcome touch spring 3 under loop electric power and the electrodynamic effect simultaneously of node counter-force begins to scold out; Scold the open position of scolding that reaches desired design when moving contact 2; The motion of scolding out of moving contact 2 makes the force direction of touch spring 3 constantly change with the shape of moving contact 2 contacting points positions along cam surface 20 along with moving pivot pin 7; When mobile pivot pin 7 is crossed the summit of cam surface 20; The direction of touch spring 3 active forces is by contact rotating shaft 1 center and between moving contact 2 contacts and contact rotating shaft 1 center; This moment touch spring 3 active force be in contact scold evolution to; Even this moment, fault current was reduced to electrodynamic repulsion force less than touch spring 3 counter-forces because of certain reason alpine rush or palm-bark rain cape, also can moving contact 2 be remained on to scold open position because of the variation of touch spring 3 counter-force directions and fall in the groove 24 of back segment stroke 23 1 sides in the effect of touch spring 3, can effectively prevent the moving contact phenomenon that contact falls in breaking course; And can realize quick disjunction; Improved the breaking capacity of breaker.

Claims

1. dropproof device of breaker of plastic casing moving contact; It comprises the contact rotating shaft and is installed on the inner chamber of contact rotating shaft and the moving contact that can rotate around contact rotating shaft center; It is characterized in that: the lower edge of said moving contact is provided with cam surface, is fixed with pivot pin in the said contact rotating shaft, is that the center is equipped with two touch springs with the moving contact on the said pivot pin; One end of said touch spring is that stiff end is connected on the pivot pin; The other end is that movable end connects mobile pivot pin, and said mobile pivot pin is installed in the chute of offering in the contact rotating shaft, and under the active force of touch spring, is pressed on the cam surface all the time.

2. the dropproof device of breaker of plastic casing moving contact according to claim 1; It is characterized in that: the both sides in cam surface on the said moving contact all have groove.

3. the dropproof device of breaker of plastic casing moving contact according to claim 1; It is characterized in that: said cam surface is that the boundary is divided into leading portion stroke and back segment stroke with the summit, and the gradient of said back segment stroke is greater than the gradient of leading portion stroke.