A kind of arc-control device of moulding case low-voltage circuit breaker
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Technical field
The present invention relates to a kind of case low-voltage circuit breaker of moulding, be specifically related to mould the arc-control device of case low-voltage circuit breaker, belong to the low-voltage electrical technical field.
Background technology
The arc control device of existing breaker of plastic casing generally all are made up of arc extinguishing grid pieces and gas exhausted material.When circuit breaker cut-off, dynamic/static contact was scolded out, and produced electric arc.Because the moving line of moving contact contact is in the cavity volume of the arc extinguishing grid pieces of arc-control device; So electric arc gets into arc extinguishing grid pieces under electrodynamic action; Arc extinguishing grid pieces becomes the short arc of a series of series connection with ARC CUTTING, electric arc is attenuated and improves arc voltage fast, thereby reach the effect of arc extinguishing.Simultaneously, when gas exhausted material cut-offs at circuit breaker, can produce gas, form certain air-blowing, in the process of arc control device gas outlet motion, electric arc blowed to the direction of grid sheet at gas.But because the arc control device rear portion is provided with an opening that provides moving contact to get into the arc control device motion; In the process of arc control device gas blast arc-quenching; The gas of some is towards this rear aperture direction motion; Cause the decline of whole arc control device blast pressure, weakened the air-blowing effect, be unfavorable for improving the arc extinction performance of circuit breaker.And when circuit breaker cut-off, because the blast pressure insufficient strength, the metallic that electric arc or electrical arc erosion contact produce can cause the short circuit between the grid sheet attached on the grid sheet, reduces the break performance of circuit breaker.Gas in the arc control device can be with the part metals particle to blow out together when the arc control device rear aperture blows out, and the dielectric strength of the arc control device Background Region of whole circuit breaker is reduced, and causes to cut-off back the withstand voltage of circuit breaker and cannot pass through.
For addressing the above problem, publication number is the arc-control device that the patent application of CN102184814A discloses a kind of breaker of plastic casing, and moving contact working of plastics forward part is to back lower place extension and be bent with a rear portion boss; Scold in the open procedure at moving contact, this rear portion boss moves to the position that blocks rear aperture with moving contact, can block the rear aperture of arc control device; Strengthen the air pressure in the arc control device; Strengthen the air-blowing effect in the arc control device, effectively promote the disjunction of breaker of plastic casing, strengthen current limiting performance.But the defective of this structure is: the bending angle and the bending shape of rear portion boss are fixed; Do not have elasticity; Just this boss just has only a kind of stationary state all the time; Can not be out of shape, so higher relatively the requirement of the size of this rear portion boss and bending angle with the generation of air-blowing in the arc control device.If the dimensioned of rear portion boss is not accurate, this rear portion boss will touch the rotating shaft of base or circuit breaker in breaker closing so, causes circuit breaker normally to close a floodgate; If the bending angle of rear portion boss is not accurate; Can cause this kind structure moving contact move to when scolding open position the rear portion boss can not the shutoff arc control device after opening not; Thereby cause gas still can move towards the direction of arc control device rear aperture; Make blast pressure decline in the arc control device, reduce the break performance of circuit breaker.
Summary of the invention
In order to solve existing defective in the present arc control device plugging structure; The present invention aims to provide a kind of device of effective shutoff arc control device rear aperture, strengthens the inner blast pressure of arc control device, and the gas that gas exhausted material produces in the arc control device is moved towards the direction of the preceding gas outlet of arc control device as far as possible; So just helping electric arc moves to the grid panel region; Thereby utilize the air-blowing effect of gas exhausted material generation more efficiently, effectively improve the interrupting performance of breaker of plastic casing, strengthen the current limiting performance of circuit breaker.Gas can strengthen the dielectric strength of the arc control device Background Region of whole circuit breaker effectively towards the motion of the direction of the preceding gas outlet of arc control device, guarantees to divide the withstand voltage of circuit breaker of having no progeny.
The technical scheme that the present invention adopts is: the arc control device with a cavity body structure; The antetheca of arc control device is provided with the gas outlet; The rear wall of arc control device is provided with a rear aperture; The moving contact front end stretches into the arc control device inner chamber from the outside through this rear aperture, and the moving contact front end connects a moving contact working of plastics, and the top of moving contact working of plastics is fixedly connected moving contact; The lower part of moving contact working of plastics be by the rear portion on top extend downwards and towards the moving contact contact make progress an elasticity bending boss of bending of direction, the initial position of elasticity bending boss has angle respectively and between horizontal direction and the moving contact; The bottom of arc control device rear wall is provided with the boss that extends to the top from the inside of rear aperture; Boss is all consistent with rear aperture with the size of elasticity bending boss on the Width of the left and right sides, is provided with one at the front end of elasticity bending boss and scolds the bending angle of evolution to bending to moving contact; When circuit breaker was in "on" position, elasticity bending boss was depressed into horizontal level by moving contact and is supported on the boss; Scold at moving contact and to reach the end during state, elasticity bending boss is positioned at the top occluding member rear aperture of boss.
The invention has the beneficial effects as follows:
1, the moving contact working of plastics is enclosed within the moving contact outside; Along with scolding out of moving contact, working of plastics is followed moving contact and is moved together, and the distortion of working of plastics elasticity bending boss can block the rear aperture of arc control device to greatest extent; Strengthen the air pressure in the arc control device, strengthen the air-blowing effect in the arc control device.
2, the elasticity boss of moving contact working of plastics below is because after the air-blowing distortion; The air-flow of pouring into the arc control device rear aperture in the arc-control device is fast stopped, and resilience change route, towards the preceding gas outlet direction motion of arc control device; In this course; Air-blowing helps electric arc to the motion of grid panel region, can effectively promote cut-offfing of breaker of plastic casing, strengthens current limiting performance.
3, this structure can occluding member arc control device rear aperture in interrupting process, strengthens air-blowing.After disjunction finished, the elasticity bending boss in this structure can return to initial condition, guaranteed the normal combined floodgate of circuit breaker.
4, circuit breaker elasticity bending boss when closing a floodgate can extend in the arc control device inner chamber in this structure, thereby guarantees normally closing a floodgate once more of circuit breaker.
5, the present invention's easy realization simple in structure, easy for installation.
Description of drawings
Below by combine accompanying drawing with shown in the infinite example to explanation preferred but not exclusive embodiment, can know and understand further characteristic of the present invention and advantage.
Show structure of the present invention compactly for more clear, omitted parts such as rotating shaft and spring in the conventional breaker of plastic casing arc-control device in the accompanying drawing.
Fig. 1 is that moving contact working of plastics 1 of the present invention is when initial condition and the assembly structure figure of moving contact 3;
Fig. 2 be among Fig. 1 moving contact working of plastics 1 at the amplification assumption diagram of initial condition;
Fig. 3 analyses and observe state diagram for the side of moving contact 3 in making process among the present invention;
Fig. 4 analyses and observe state diagram for circuit breaker side of the present invention when closing position;
Fig. 5 is the state diagram of circuit breaker when closing position;
Fig. 6 is the state diagram of circuit breaker when the separating brake position;
Fig. 7 analyses and observe state diagram for circuit breaker side of the present invention when the separating brake position;
Among the figure: 1. moving contact working of plastics; 2. arc control device; 3. moving contact; 11. elasticity bending boss; 21. gas outlet; 22. rear aperture; 23. boss; 111. bending angle.
Embodiment
Arrive shown in Figure 7 referring to Fig. 3; The present invention has arc control device 2, and arc control device 2 are a kind of cavity body structures, and the antetheca of arc control device 2 is provided with gas outlet 21; On the rear wall of arc control device 2, offer a rear aperture 22, rear aperture 22 makes way for moving up and down that moving contact 3 does when divide-shut brake.In arc control device 2, be provided with boss 23 in the bottom of arc control device 2 rear walls.Boss 23 and the consistent size of rear aperture 22 on left and right directions, boss 23 are the boss that extend certain altitude from the inside of rear aperture 22 to the top of opening, and boss 23 can play 2 effects, the firstth, reduce the area of arc control device 2 rear aperture 22; The secondth, supporting role: because the elasticity bending boss 11 on the moving contact working of plastics 1 has certain angle and has elasticity when initial condition; Make elasticity bending boss 11 when moving contact 3 "on" positions, be in level and extend in the arc control device 2 through rear aperture 22; Just require moving contact 3 to rely on the pressure straight down of self to make elasticity bending boss 11 arrive the state shown in Fig. 4; Boss 23 in this process on the arc control device 2 can also play the effect of supporting the elasticity bending boss 11 on the moving contact working of plastics 1, guarantees that elasticity bending boss 11 can arrive the position shown in Fig. 4.Moving contact 3 front ends stretch into arc control device 2 inner chambers from the outside through this rear aperture 22, and in breaker open operation and making process, moving contact 3 moves up and down along rear aperture 22.
Shown in Fig. 1 and 2, the present invention connects a moving contact working of plastics 1 at moving contact 3 front ends, and moving contact working of plastics 1 is divided into upper and lower two parts.Top is in order to be fixedly connected moving contact 3.The lower part of moving contact working of plastics 1 is to extend an also elasticity bending boss 11 of bending downwards by the rear portion on top; The wrap direction of elasticity bending boss 11 is the bendings that make progress of the direction towards the contact of moving contact 3, elasticity bending boss 11 and the consistent size of rear aperture 22 on the Width of the left and right sides.Between the initial position of elasticity bending boss 11 and horizontal direction and the moving contact 3 certain included angle is arranged all.Promptly be provided with one at the front end of elasticity bending boss 11 and scold the bending angle 111 of evolution to the bending certain angle to moving contact 3 near the position of moving contact.When moving contact 3 closed a floodgate, bending angle 111 can guarantee that elasticity bending boss 11 is smoothly through the boss 23 on arc control device 2 rear walls.As shown in Figure 3; In moving contact 3 making processes, elasticity bending boss 11 begins to rely on the downforce of moving contact 3 to be pressed down from initial condition, when bending leg 111 has just begun to touch with boss 23; Because it has certain slick and sly excessive bending angle; So can make it streak the boss 23 on the arc control device 2, reduce the frictional force between the boss 23 on elasticity bending boss 11 and the arc control device 2, guarantee the normal combined floodgate of circuit breaker.If the boss 23 that elasticity bending boss 11 is run on the arc control device rear wall will cause moving contact 3 to be stuck, circuit breaker can not normally be closed a floodgate.
Shown in Fig. 4 and Fig. 5; When circuit breaker is in "on" position; Elasticity bending boss 11 on the moving contact working of plastics 1 is pressed onto illustrated state by moving contact 3 pressure straight down, and this moment, the rear section of moving contact 3 was positioned at outside the rear aperture 22, and near horizontal level.Elasticity bending boss 11 extends in the inner cavity volume of rear aperture 23 and near horizontal level.In the time of can guaranteeing that like this moving contact 3 is in "on" position, the elasticity bending boss 11 on the moving contact working of plastics 1 can not touch mutually with the base of circuit breaker or the rotating shaft of circuit breaker, makes circuit breaker be in normal "on" position.
Shown in Fig. 6 and Fig. 7; Scold in the open procedure at moving contact 3; When scolding out because of moving contact 3 earlier, the bottom elasticity bending boss 11 of moving contact working of plastics 1 press pressure above that to disappear; Be released the initial condition of getting back to elasticity bending boss 11, then because of air-blowing launches backward, and the rear aperture 22 of arc control device 2 has been blocked with shutoff in the motion of scolding out of following moving contact 3 to greatest extent.The below elasticity bending boss 11 of moving contact working of plastics 1 is owing to unfolded the distortion backward up to disjunction of air-blowing power of the gas that gas exhausted material produces finished.Scold when reaching the end when moving contact 3, the rear elastic boss 11 of moving contact working of plastics 1 shelters from part rear aperture 22, has reduced the gas effusion area of the rear aperture 22 of arc control device.When moving contact 3 was scolded out this state, the bending leg 111 on the elasticity bending boss 11 was positioned at the top of the boss 23 of arc control device 2, guaranteed normally closing a floodgate once more of moving contact 3.When circuit breaker cut-off, the gas part that the inner gas exhausted material of arc control device produces was towards 22 motions of arc control device rear aperture, touch elasticity bending boss 11 after, the gas resilience of rapid movement also changes route, gas is discharged through gas outlet 21.In the extremely short time, improved the rate of climb of arc control device 2 air pressure inside, made gas pass through gas outlet 21 as far as possible and discharge, can effectively change, like this, helped strengthening the air-blowing effect of arc control device 2 inside towards the gas direction of arc control device 2 rear aperture 22 motions.Discharge in the process of motion towards gas outlet 21 at the arc control device internal gas, help electric arc to the motion of grid sheet direction, gas drives the arc extinguishing grid pieces regional movement of electric arc in the arc control device, and electric arc is comparatively fast extinguished, and can strengthen the interrupting performance of circuit breaker effectively.Gas is discharged through gas outlet 21, also can guarantee the dielectric strength of the arc control device Background Region of circuit breaker.Simultaneously, this elasticity bending structure Design of moving contact working of plastics 1 can guarantee in the motion process of moving contact 3, to be unlikely to touch the circuit breaker base or rotating shaft causes circuit breaker normally to close a floodgate.After disjunction finishes; The below elasticity bending boss 11 of moving contact working of plastics 1 can rely on the strain of self to return to state as shown in fig. 1 again; The bending angle 111 in elasticity bending boss 11 the place aheads can guarantee elasticity bending boss 11 smoothly through the boss 23 on arc control device 2 rear walls, thereby guarantees the reliable combined floodgate of circuit breaker.The present invention is simple in structure, and is easy for installation, solved existing problem in the present arc-extinguishing chamber of circuit breaker plugging structure effectively.