The contact system of circuit breaker
Technical field
The utility model relates to a kind of contact system of circuit breaker, and when big fault current took place, it can fast cut-off circuit also guarantee not make fault current conducting once more, plays the current-limiting protection effect.
Background technology
The contact system of circuit breaker can be connected under the drive of operating mechanism or the branch deenergizing; also be provided with release in the circuit breaker simultaneously, when overload or short circuit took place circuit, release can drive operating mechanism separated dynamic and static contact; cut off circuit, play the effect of protection.Yet the protective effect of release is limited; because the action of release is slow relatively, after the release action, also to dynamic and static contact be separated through a series of mechanical transfer process; for king-sized fault current, this reaction speed can't guarantee circuit safety.
The electrodynamic repulsion force that utilizes fault current to produce directly makes dynamic and static contact separate, and can reach the purpose of fast cut-off circuit, and this technology has obtained application in the existing circuit breaker contact system.After moving contact is scolded out, if operating mechanism does not also have enough time to move, moving contact may fall after rise under the effect of touch spring again, once more and fixed contact form closure or between dynamic and static contact, produce electric arc, not only influence current limitation effect, also can cause the serious scaling loss of contact even melting welding takes place, make fault current damage load elements.Therefore, in this contact system, the mechanism that stops moving contact to fall after rise can be set all generally.
Disclose a kind of contact system of circuit breaker as Chinese utility application CN101030506A, as shown in Figure 1, it comprises a pair of each tool fixed contact 11 stationary contact bars 1 and one group of movable contact assembly.This movable contact assembly comprises: a center main bearing 2 that be connected with the operating mechanism of circuit breaker and that rotate under operating mechanism drives, one is positioned at the movable contact 3 on the described center main bearing 2 movably, the a pair of movable contact arm 31 of movable contact 3 stretches out from the both sides of described center main bearing 2, the end of each movable contact arm 31 disposes accordingly with described fixed contact respectively and is used for the moving contact 311 connecting or separate with fixed contact, one the clamping mechanism of separation point position end after being used for remaining on movable contact 3 on the center main bearing and the movable contact arm 31 of movable contact is maintained repelling each other out with fixed contact, described clamping mechanism comprises a pair of first, second pivot and a pair of spring 5, and be used for cross-over connection first, the push rod 6 of second pivot, the rear end that a pair of first pivot 4 passes push rod 6 is arranged on the pivot channel 21 of center main bearing, and the center with center main bearing 2 is symmetrical distribution, a pair of second pivot 7 is fixed on the movable contact 3 with the center of movable contact with being symmetrical distribution, and with the preceding client link of push rod 6, the two ends of a pair of spring 5 are articulated in respectively on movable contact 3 and a pair of first pivot 4.
Adopted this block structure after, though can be when movable contact be scolded out, block movable contact fully, prevent that moving contact from falling after rise, plays the current-limiting protection effect, but also have following defective: one, clamping mechanism scolds the resistance that acts in the open procedure on the moving contact bigger at moving contact, be unfavorable for that moving contact scolds out fully, in the process that contact resets, need bigger restoring force that contact is resetted in the center main bearing, thus operating physical force that also can swelled handle; Two, complex structure, small part is more, has increased difficulty for manufacturing and assembling.
The utility model content
The technical problems to be solved in the utility model provides the contact system of the simpler circuit breaker of a kind of structure, and it both can play the effect of current-limiting protection, does not need very big lever operated power again.
In order to solve the problems of the technologies described above, the utility model adopts following technical scheme: a kind of contact system of circuit breaker, comprise a pair of have stationary contact bar, the rotating shaft of sweep and the movable feeler lever that can in rotating shaft, rotate, this system comprises that also a contact delays mechanism, this contact delays mechanism and comprises: a pair of first groove is positioned at the back side of movable feeler lever; A pair of first pivot pin, can be installed in the rotating shaft with fluctuating and with the parallel axes of rotating shaft, when movable feeler lever when the direction of separating with the stationary contact bar is rotated, described first pivot pin can match with first groove; Two pairs of extension springs are arranged in the both sides of movable feeler lever, and an end of extension spring is connected with first pivot pin, and the other end is connected with movable feeler lever.
The beneficial effects of the utility model are: when dynamic and static contact closure, the tension of extension spring has guaranteed the closed end pressure between the dynamic and static contact at movable feeler lever.When big fault current occurring in the circuit, electrodynamic repulsion force is scolded out movable feeler lever, movable feeler lever rotates in rotating shaft, when turning to certain angle, first groove at the movable feeler lever back side contacts with first pivot pin to form and cooperates, though this cooperation can not stop movable feeler lever to fall after rise fully, can delay the speed that movable feeler lever falls after rise, for the tripping operation action of operating mechanism is raced against time.That is to say, the utility model can delay the falling of movable feeler lever, avoid movable feeler lever rapid falling before the operating mechanism tripping operation to form current path again, perhaps form the electrical arc erosion contact once more, do not need movable feeler lever is blocked the effect that also can reach restriction, disjunction fault current fully.Because delaying mechanism, the contact in the utility model only need a less power to delay the movable feeler lever falling, rather than it is blocked fully, therefore movable feeler lever does not just need to overcome very big resistance in the process of scolding out, and does not need very big lever operated power when contact resets yet.In addition, the utility model only just can be played the effect of current-limiting protection by several pivot pins cooperation touch springs and groove, simple in structure, is convenient to make and assembling.
Preferably, described contact delays mechanism and also comprises a pair of second groove and a pair of second pivot pin, and second groove is positioned at the back side of movable feeler lever, and second pivot pin is positioned at second groove, and the end that described extension spring is connected with movable feeler lever is articulated on this second pivot pin.
Preferably, described contact delays the center symmetry of mechanism with respect to rotating shaft.Help the balance contact pressure like this.
Preferably, in the described rotating shaft cavity is arranged, described two pairs of extension springs all are positioned at this cavity.Spring is positioned at rotating shaft inside, can protect spring not to be subjected to the damage of electric arc.
Preferably, the two ends of described rotating shaft are provided with the pivot pin groove, and the two ends of described first pivot pin are bearing in the pivot pin groove slidably.
Description of drawings
Below in conjunction with the drawings and specific embodiments the utility model is described in further detail.
Fig. 1 is the structural representation of a kind of breaker contact system of the prior art.
Fig. 2 is the schematic diagram (the stationary contact bar is not shown) of a kind of breaker contact system of the utility model.
Fig. 3 is the shape schematic diagram of movable feeler lever.
Fig. 4-Fig. 6 shows that movable feeler lever is scolded out and with respect to the rotating shaft rotating process.
Fig. 7-Fig. 9 show rotating shaft under the drive of operating mechanism with respect to the movable feeler lever rotating process.
Embodiment
The double-breakpoint contact system of a kind of circuit breaker of the utility model such as Fig. 2, shown in Figure 4, it comprises a pair of stationary contact bar 600 with sweep, stationary contact bar 600 is provided with fixed contact 601; A rotating shaft 200 between two stationary contact bars; A movable feeler lever 100 passes from rotating shaft 200, and movable feeler lever 100 is pivotally connected in rotating shaft 200 by one, and can rotate in rotating shaft 200.The two ends of movable feeler lever 100 are provided with moving contact 105 and can contact with fixed contact 601, movable feeler lever 100 is a centrosymmetric structure, its shape as shown in Figure 3, the back side of movable feeler lever 100 is provided with a pair of first groove 101, a pair of first projection 103, a pair of second groove 102 and a pair of second projection 104 symmetrically, wherein first groove 101 is between first projection, 103 and second projection 104, second groove 102 is positioned at the outside of second projection 104, and first projection 103 is made of smooth curved surface.
Continuation is referring to Fig. 2 and Fig. 4, be provided with two pairs of pivot pin grooves 202 symmetrically at the two ends of rotating shaft 200, a pair of first pivot pin 400 arranges that with the parallel axes of rotating shaft 200 first pivot pin, 400 two ends are bearing in respectively in the pivot pin groove 202, thereby first pivot pin 400 can fluctuate along pivot pin groove 202.Comprise that also second pivot pin 500 does not contact with rotating shaft 200 in horizontal second groove that is pressed in movable feeler lever 100 back sides of a pair of second pivot pin, 500, the second pivot pins 500.Be provided with two cavitys 201 in the rotating shaft 200, these two cavitys 201 lay respectively at the both sides of movable feeler lever 100, and two pairs of extension springs 300 lay respectively in these two cavitys 201, can well be protected, and avoid by electrical arc erosion.One end of every pair of extension spring 300 is articulated on one first pivot pin 400, and the other end is articulated on one second pivot pin 500.Under the tension of extension spring 300, second pivot pin 500 is pressed on the movable feeler lever 100, adds the position-limiting action of second projection 104, and second pivot pin 500 is equivalent to be fixed on the movable feeler lever 100.That is to say,, and second pivot pin 500 directly is fixed on the movable feeler lever 100, also can implement the utility model in the same old way by modes such as pin-and-hole or welding if second groove 102 and second projection 104 are not set at the back side of movable feeler lever 100.In addition, way among the documents CN101030506A that is quoted as this specification background technology part, two extension spring forms are all adopted in every pair of extension spring 300, directly be pressed on the movable feeler lever 100 with extension spring, so just can be fully need not second pivot pin 500, so second groove 102, second projection, 104 and second pivot pin 500 in the present embodiment are not essential for implementing the utility model.
In order more clearly to introduce the utility model, the following describes the course of work of the foregoing description.
At first the process that movable feeler lever is scolded out is described in conjunction with Fig. 4-Fig. 6.As shown in Figure 4, when contact closure moving contact 105 contacted with fixed contact 601, the pulling force of extension spring 300 acted on the movable feeler lever 100 by second pivot pin 500, so that the contact closure end pressure to be provided.At this moment, first pivot pin 400 is under the tension of extension spring 300, and its two ends are pressed on the bottom land of pivot pin groove, with movable feeler lever 100 and contactless.
When big fault current took place, movable feeler lever 100 was scolded out, and rotated along the direction of separating with the stationary contact bar in rotating shaft, and when going to certain angle, first projection, 103 beginnings at movable feeler lever 100 back sides contact with first pivot pin 400, as shown in Figure 5.
Along with movable feeler lever 100 is rotated further, first projection 103 promotes first pivot pin 400 and outwards moves along pivot pin groove 202, and after first projection 103 was crossed first pivot pin 400, first pivot pin 400 fell in first groove 101, as shown in Figure 6.In this process, the repulsion that movable feeler lever is subjected to is in decay, and extension spring is increasing by the restoring force that second pivot pin 500 acts on the movable feeler lever 100, therefore movable feeler lever 100 has the trend of falling under the compressing of second pivot pin 500, first pivot pin 400 is with after first groove 101 contacts, the torque that first pivot pin 400 is applied on the movable feeler lever 100 is opposite with the torque that second pivot pin 500 applies, and therefore can delay the falling of movable feeler lever, for the tripping operation action of operating mechanism is raced against time.Therefore, above-mentioned first groove 101, first pivot pin 400 and extension spring 300 etc. have just constituted a contact and have delayed mechanism, can delay contact and fall after rise, rather than contact is blocked fully.
Next after in conjunction with Fig. 7-Fig. 9 description operation mechanism the tripping operation action taking place, the course of action of the utility model contact system.
As shown in Figure 7, because contact delays the falling that mechanism has delayed movable feeler lever, before movable feeler lever fell, tripping operation had taken place in operating mechanism, drove rotating shaft 200 and clockwise rotated, and movable feeler lever 100 is static under the restriction of block 700.
As shown in Figure 8, rotating shaft continues to clockwise rotate with respect to movable feeler lever, and first pivot pin begins to cross first projection.From first groove, deviate from fully until first pivot pin, as shown in Figure 9.So just finished the process that movable feeler lever resets in rotating shaft.Work as trouble shooting, when driving handle closed a floodgate operating mechanism, rotating shaft also can drive movable feeler lever and stationary contact bar closure, comes back to state shown in Figure 4.
Contact in the utility model delays mechanism not to be needed movable feeler lever is blocked fully, can reach the purpose of current-limiting protection yet. With Adopt the contact system of clamping mechanism to compare, the pulling force that the utility model can the reasonable design spring, the degree of depth of first groove and The position of position, first pivot pin so that movable feeler lever do not need to overcome very big resistance in the process of scolding out, when contact resets also Do not need very big restoring force, and then can reduce lever operated power yet.