CN2727945Y

CN2727945Y - Oil buffer for circuit breaker

Info

Publication number: CN2727945Y
Application number: CN 200420071134
Authority: CN
Inventors: 陈崇立; 何锐鑫
Original assignee: SHUNDE SWITCH CO Ltd GUANGDONG PROV
Current assignee: SHUNDE SWITCH CO Ltd GUANGDONG PROV
Priority date: 2004-07-01
Filing date: 2004-07-01
Publication date: 2005-09-21
Anticipated expiration: 2014-07-01

Abstract

The utility model relates to an oil buffer for circuit breaker, which comprises a buffer sleeve and a big plunger. A hollow inner chamber which is used for the oil circulating and buffering is arranged at the lower section of the big plunger, via holes which are separately positioned at the upper part and the lower part of the plunger core are arranged on the big plunger, and the hollow inner chamber is connected with the inner chamber of the buffer sleeve by the upper via hole and the lower via hole. The lower via hole which can gradually seal off the plunger core is arranged at the lower part of the hollow inner chamber, so the small plunger of the hollow inner chamber which is used for the buffering of the oil flow quantity can be controlled. A small reset spring is arranged between the big plunger and the small plunger. Compared with present technology, the utility model is provided with B grade buffering function, so the buffering effect can be improved. When the braking division of the breaker happens, the spring back of the contact head can drop to a minimum degree; thereby, in the process of the braking division of the breaker, the various problems which are happened by the poor performance of the oil buffer can be solved, and the useful life of the breaker can be prolonged.

Description

The oil bumper that circuit breaker is used

Technical field

The utility model relates to a kind of oil bumper, particularly a kind of oil bumper that is applicable in the primary cut-out.

Background technology

At present, in the high-tension electricity user of middle pressure field, power plant using electricity system and the every profession and trade of electric power system, the use of high-pressure vacuum breaker is quite general, and buffer is also quite big to the circuit breaker Effect on Performance.Bounce-back when the vacuum circuit-breaker of lot of domestic and international manufacturer production all uses buffer to reduce separating brake now can guarantee that circuit breaker has higher breaking capacity.Oil bumper commonly used at present belongs to " first-level buffer " from operation principle, when big piston presses down, the gap of buffering oil between big piston and sleeve flows to upper chamber from the lower chambers of buffer casing, along with dwindling oily resistance gradually, the gap increases gradually, cause dump energy effectively to be absorbed, play cushioning effect; But oily resistance is also relevant with piston movement speed, and speed is slow more, and resistance is more little.So conventional buffer is difficult to satisfy the requirement of circuit breaker open mechanical characteristic, demand urgently being improved.

Summary of the invention

The purpose of this utility model is to overcome the deficiencies in the prior art, a kind of circuit breaker oil bumper with level 2 buffering effect is provided, it both can make breaker open operation speed keep higher level, the energy in separating brake later stage is all discharged, thereby make the bounce-back of contact be reduced to minimum degree.

The purpose of this utility model is achieved by following technical proposals: design the oil bumper that a kind of circuit breaker is used, comprise buffer casing, big piston, the upper end tool crown cap of big piston, the middle part of big piston has the plug core, be provided with big back-moving spring between big piston bottom and the cover tube bottom, the hypomere of big piston also has the hollow cavity of the buffering oil that is used to circulate, have the through hole that lays respectively at plug core above and below on the big piston, described hollow cavity communicates with barrel bore via top through hole and below through hole; Thereby the bottom of described hollow cavity is provided with the valve piston that the below of closing cock core gradually through hole control hollow cavity cushions oily flow, also is equiped with little back-moving spring between big piston and the valve piston.

Be positioned at the through hole of plug core top and the through hole of plug core below and respectively be four, four through holes of each side are positioned at same plane, and are mutually the right angle.

Oil bumper of the present utility model compared with prior art, owing in big piston, also increased the hollow cavity of a fuel feeding circulation, after forming liquid sealing between the plug core of big piston and the sleeve lining, buffering oil can also continue to flow to upper chamber through this hollow cavity from the lower chambers of sleeve, buffering is continued, and buffering oil flow by valve piston control hollow cavity, therefore has the function of " level 2 buffering ", its buffering effect is improved, the bounce-back of contact is reduced to minimum degree in the time of can be breaker open operation, thereby solved the variety of issue that circuit breaker causes owing to the oil bumper poor performance in the separating brake process, and prolonged the useful life of circuit breaker.

Description of drawings

Fig. 1 is the structural representation of the utility model oil bumper;

Big piston structural representation in Fig. 2 buffer;

Fig. 3 is a first order buffering operation principle schematic diagram of the present utility model, and large and small back-moving spring is all not shown among the figure;

Fig. 4 is a second level of the present utility model buffering operation principle schematic diagram, and large and small back-moving spring is all not shown among the figure;

Structural representation when Fig. 5 is the end of the utility model buffering course, large and small back-moving spring is all not shown among the figure;

The displacement-time curve figure of moving contact of breaker when Fig. 6 is the work of traditional oils buffer, y direction is represented displacement, the X direction express time;

The displacement-time curve figure of moving contact of breaker when Fig. 7 is the work of the utility model buffer, y direction is represented displacement, the X direction express time.

Embodiment

Below in conjunction with accompanying drawing embodiment of the present utility model is described.

As shown in Figure 1, the oil bumper that circuit breaker of the present utility model is used comprises buffer casing 1, valve piston 2, big piston 3 and sleeve top cover 4, sleeve top cover 4 is provided with sealing ring 6 with the matching part of big piston 3 and sleeve 1, the upper end dress crown cap 5 of big piston 3, be provided with little back-moving spring 7 between big piston 3 and the valve piston 2, this little back-moving spring 7 is positioned at hollow cavity 11, is provided with big back-moving spring 8 between big piston 3 and sleeve 1 bottom interior surface.In order to realize the effect of " level 2 buffering ", make under the situation that cushions oil liquid sealing between big piston plug core and sleeve lining and can also flow to upper chamber 12 from the lower chambers in the sleeve 1 10, also be provided with the hollow cavity 11 of the buffering oil that is used to circulate at the hypomere of big piston 3, the through hole 13 of this hollow cavity 11 through being positioned at big piston plug core top is communicated with upper chamber 12, through hole 14 through plug core below is communicated with lower chambers 10, and the flow of buffering oil can be by valve piston 2 controls.Described through

hole

13,14 can be provided with eight, and wherein four are positioned at big piston plug core top, and other four are positioned at big piston plug core below, and four through holes of each side are mutually the right angle.

Its course of work is shown in Fig. 3～5, and the buffering oil 9 of packing into suitable in the sleeve 1 of oil bumper is plugged big piston 3, seals with sleeve top cover 4 and sealing ring 6 then.When circuit breaker when the state that closes a floodgate is pressed opening button, breaker open operation, linkage bump oil bumper top cap 5, big piston 3 promotes valve pistons 2 and dashes downwards together.On the one hand, big back-moving spring 8 withstands big piston 3 and plays certain cushioning effect, on the other hand, buffering oil flows to upper chamber 12 from lower chambers 10, thereby makes moving down of big piston 3 obtain buffering, and moving down along with big piston 3, gap between piston 3 and the sleeve 1 is more and more littler, cushion effect is increasing, has cushioned the following of big piston 3 effectively and has dashed, and the flow direction of buffering oil as shown in Figure 4.

When big piston is displaced downwardly to position shown in Figure 4, form liquid sealing between the outer ring surface of big piston plug core and the sleeve lining, buffering oil flows to upper chamber 12 from lower chambers 10 in the gap between big piston 3 and sleeve 1 inwall again, but can continue to flow to upper chamber 12 through the hollow cavity in the big piston 3 11, and when big piston 3 moves down into sleeve 1 bottom that makes buffer valve piston 2 withstand oil bumper (position shown in Figure 5), valve piston 2 will reduce the flow of oil gradually by the liquid flow section that changes lower floor's through hole, cushion effect increases gradually, and big piston 3 is stopped.The oil resistance is not only relevant with the flow size, and also relevant with piston movement speed, speed is slow more, and resistance is more little.The separating brake after-stage, big piston 3 speed are more and more littler, cause resistance also more and more littler, are difficult to make the piston stop motion, and this also is that conventional buffer is difficult to one of reason that satisfies circuit breaker open mechanical characteristic.And " secondary buffer " of valve piston 2 can reduce flow, increases resistance, and the speed of the remedying caused deficiency that descends makes moving down of big piston 3 obtain the buffering of optimum efficiency, guarantees the breaking capacity of circuit breaker.

Fig. 6 is a displacement coordinate for the displacement curve figure of the moving contact of breaker under the conventional buffer work, longitudinal direction, and X direction is a time coordinate, and as seen from the figure, when the firm separating brake of circuit breaker, moving contact displacement maximum promptly links together with fixed contact; Separation along with moving contact, the very fast arrival minimum value of displacement, be that moving contact and fixed contact arrive complete separation point position, but because the traditional oils buffer does not have level 2 buffering, moving contact is under the effect of bounce, bounce-back (2.59mm) by a relatively large margin appears in moving contact, makes to be easy to generate electric arc between the dynamic and static contact and to burn out contact.

Fig. 7 is the displacement curve figure of moving contact under the oil bumper work of the present utility model and on same circuit breaker, longitudinal direction is a displacement coordinate, X direction is a time coordinate, and as seen from the figure, displacement diminishes with big slope from maximum, be that moving contact of breaker separates with fixed contact with big speed, along with the separation of dynamic and static contact, the displacement curve slope is more and more littler, and displacement finally is a steady state value, be that opening velocity diminishes gradually, final dynamic and static contact separates fully.In whole separating brake process, oscillogram does not have a rebound, be that moving contact is when separating with fixed contact, because the utility model oil bumper has level 2 buffering, kinetic energy in the time of can discharging the separation of moving contact fully, and moving contact can not rebound, thereby guarantees circuit breaker separating brake and do not burn out contact well.

Claims

1, the oil bumper used of a kind of circuit breaker, comprise buffer casing (1), big piston (3), the upper end tool crown cap (5) of big piston, the middle part of big piston has the plug core, be provided with big back-moving spring (8) between big piston bottom and the cover tube bottom, it is characterized in that: the hypomere of big piston (3) also has the hollow cavity of the buffering oil that is used to circulate, and has the through hole that lays respectively at plug core above and below on the big piston, and described hollow cavity communicates with barrel bore via top through hole and below through hole; Thereby the bottom of described hollow cavity is provided with the valve piston that the below of closing cock core gradually through hole control hollow cavity cushions oily flow, also is equiped with little back-moving spring (7) between big piston and the valve piston.

2, oil bumper according to claim 1 is characterized in that: the through hole of the through hole of plug core top and plug core below respectively is four, and four through holes of each side are positioned at same plane, and are mutually the right angle.