CN201627853U - Brake piston mechanism of rear brake calipers - Google Patents

Abstract

A brake piston mechanism of rear brake calipers comprises a piston body, a travel adjusting nut, a waveform spring and a clamp spring. The front end of an inner cavity of the piston body is provided with a small cylindrical first cavity capable of holding the head end of a travel adjusting screw stem when in an early installation state, the middle of the inner cavity of the piston body is further provided with a conical second cavity capable of holding the travel adjusting nut, the head of the second cavity is connected with the tail of the small cylindrical first cavity, a cylindrical third cavity capable of holding the waveform spring and the clamp spring is arranged on the middle rear portion of the inner cavity of the piston body, and a large cylindrical fourth cavity is disposed at the tail of the inner cavity of the piston body. The brake piston mechanism removes a structure of an assisting piston and a gripping mechanism of the assisting piston and the adjusting nut by aid of structural change of the inner cavity of the piston body, thereby removing structures of a small exhaust hole and a sealing ring, reducing probability of oil leakage risks and jamming faults, and leading brake to be safer and more reliable. The brake piston mechanism with improved structure is simpler in structure and easier in processing, and then has extremely strong practicality.

Description

Back brake calipers brake piston mechanism

Technical field

The utility model relates to a kind of arrestment mechanism of car back axle, specifically is meant a kind of back brake calipers brake piston mechanism.

Technical background

Before the present utility model, the back brake calipers brake piston mechanism that generally uses in the industry is the brake piston mechanism of the band automatic adjusting mechanism announced in the patent document of notification number as CN1187866.In this mechanism, adjust nut driving one axially slidably but on the rotatable screw rod (screw rod does not draw), an auxiliary piston is arranged in the piston body inner chamber slidably, by one axially the snap-in of locking connect with the adjustment nut and be connected.And by on nut and auxiliary piston, offering the discharge that air vent is finished inner air separately.

But this mechanism element quantity is many, and part processing complexity and difficulty are big.On the one hand, in this piston mechanism,,, on piston body, small de-air hole must be set for getting rid of the air of piston body inner chamber front portion owing to there is auxiliary piston.And, must on auxiliary piston, increase lip-type packing for avoiding the small de-air hole leakage of oil.When the excess of stroke appearred in piston, auxiliary piston may skid off the brake piston intracoelomic cavity, caused leakage of oil to make hydraulic failure.Even the excess of stroke not, the shape of seal ring also are difficult to guarantee, and seal ring is aging easily, also is the potential risk of leakage of oil.On the other hand,, hinder the compensation rotation of adjusting nut, thereby influence the stroke adjustment, cause braking unable because auxiliary piston is easy to generate stuck fault with the snap-in linkage structure of adjusting nut.Simultaneously, adjusting nut is to need rotation when stroke compensates, on nut, offer air vent like this and just be difficult to guarantee that air vent is in the top all the time, just can't guarantee that also the inner all air of piston mechanism can discharge smoothly when exhaust, may cause braking weak.

Summary of the invention

The purpose of this utility model is to provide a kind of simple in structure at above-mentioned deficiency, and difficulty of processing is low, and the more safe and reliable back brake calipers brake piston of braking mechanism.

The utility model is achieved in that back brake calipers brake piston mechanism, and it comprises piston body, stroke adjustment nut, wavy spring and jump ring.The inner chamber front end of described piston body is provided with small cylindrical first cavity of stroke adjustment screw rod head end in the time of can holding first dress state; The inner chamber middle part of piston body also is provided with taper shape second cavity that can hold the stroke adjustment nut, and described second cavity head and the small cylindrical first cavity afterbody join; The inner chamber mid-rear portion of piston body is provided with cylindrical the 3rd cavity that can hold wavy spring and jump ring; The inner chamber afterbody of piston body is provided with great circle cylindricality the 4th cavity.

Have at least one arc first air vent on described conical second cavity, have at least one arc second air vent on cylindrical the 3rd cavity, described first air vent and second air vent join end to end.

The front end of described piston body is provided with at least one anti-rotation locating slot.

The inner chamber afterbody of described piston body is provided with the jump ring groove.

The position of described first air vent and second air vent is under the entrucking state, the piston cavity top that the anti-rotation locating slot is fixing.

The degree of depth of described second air vent is greater than the degree of depth of jump ring groove.

The utility model compared with prior art, the structure of auxiliary piston and the snap-in mechanism of auxiliary piston and adjustment nut have been removed by the change structurally of inner chamber in the piston body, and then removed the structure of exhaust hole and seal ring, reduced the risk of leakage of oil and the possibility of stuck fault, made braking more safe and reliable.Simultaneously, in the utility model air vent is reached the inner chamber of piston body, thereby and the structure of setting up the anti-rotation locating slot guaranteed the smooth and easy of exhaust.This structural improvement makes structure simpler, and processing is more prone to, and therefore has very strong practicability.

Description of drawings

Fig. 1 is that the A-A of piston body structure in the utility model is to sectional view;

Fig. 2 is the right elevation of piston body structure in the utility model;

Fig. 3 is a left view of the present utility model;

Fig. 4 is the three-dimensional cutaway view of piston body structure in the utility model;

Fig. 5 is a sectional view of the present utility model;

Fig. 6 is the sectional view that has back brake calipers brake piston mechanism now.

Among the figure: 1. piston body, 2. anti-rotation locating slot, 3. first cavity, 4. first air vent, 5. jump ring groove, 6. second air vent, 7. the 3rd cavity, 8. the 4th cavity, 9. second cavity, 10. stroke adjustment nut, 11. plane bearing, 12. stroke adjustment screw rod, 13. jump ring, 14. flat gasket I, 15. wavy spring, 16. flat gasket II, 17. former adjustment nut, 18. former piston body, 19. former auxiliary piston, 20. former exhaust hole, 21. former seal ring, 22. former first air vent, 23. jump ring in former, 24. former second air vent.

Embodiment

Describe performance of the present utility model in detail below in conjunction with accompanying drawing, but they do not constitute to qualification of the present utility model, only do for example.Simultaneously by illustrating that advantage of the present utility model will become clear more and understanding easily.

Structure of the present utility model such as Fig. 1, Fig. 4 and shown in Figure 5, it includes piston body 1, stroke adjustment nut 10, jump ring 13, flat gasket I 14, wavy spring 15, flat gasket II 16, plane bearing 11.The inner chamber of piston body 1 comprises small cylindrical first cavity 3, conical second cavity 9, cylindrical the 3rd cavity 7, great circle cylindricality the 4th cavity 8 successively.The head end of stroke adjustment screw rod 12 when described small cylindrical first cavity 3 is used for holding first dress state.The head of described conical second cavity 9 links to each other with the afterbody of first cavity 3, can hold stroke adjustment nut 10, is used for bearing the retrothrust that stroke adjustment nut 10 transmits.Accommodate plane bearing 11, flat gasket II 16, wavy spring 15, flat gasket I 14 and jump ring 13 successively in described the 3rd cavity 7, wherein also do not have and jump ring 13 corresponding jump ring grooves 5 in the 3rd cavity 7, be used for fixing the assembly of piston mechanism.Described the 4th cavity 8 has got out of the way the position of master cylinder internal structure and piston mechanism interference, helps dwindling the master cylinder volume, alleviates the weight of whole brake calipers.And, have at least one arc first air vent 4 on conical second cavity 9, have at least one arc second air vent 6 on cylindrical the 3rd cavity 7, above-mentioned first air vent 4 and second air vent 6 join end to end.As shown in Figure 2, for evenly offering first air vent 4 and second air vent, 6 each piston body structure right elevation of four.The structure of this air vent has been avoided the air drain that begins to rehearse on stroke adjusting nut 10.The degree of depth of second air vent 6 is greater than the degree of depth of jump ring groove 5, can guarantee so also not block second air vent 6 when jump ring 13 is fixed in the jump ring groove 5, just guarantees the unobstructed of exhaust.And as shown in Figure 3,, can fix first air vent 4 and second air vent 6 under the entrucking state by offering anti-rotation locating slot 2 at the piston body head, be in the top of piston cavity all the time.Simultaneously, anti-rotation locating slot 2 matches with location anti-rotation boss (not marking among the figure) on being arranged on braking plate, can also prevent the rotation of piston body.

The utility model is compared with Fig. 6 of prior art, removed auxiliary piston 19 of the prior art and interior jump ring 23, and then has removed the structure of exhaust hole 20, seal ring 21.So not only simplify the structure of piston body, also can reduce the leakage of oil that causes owing to seal ring, and then caused the possibility of braking failure.Simultaneously, removing interior jump ring 23 also can reduce owing to the interior jump ring 23 stuck possibilities that cause hindering stroke adjustment nut 17 rotation compensation.Further, the utility model also also has been improved to former first air vent 22 and second air vent 24 on second cavity 9 and the 3rd cavity 7 from auxiliary piston 19 of the prior art and stroke adjustment nut 17, makes air can not cause because of the rotation of stroke adjustment nut 17 and can't discharge.And can fix first air vent 4 and second air vent 6 under the entrucking state at the anti-rotation locating slot 2 that piston body 1 head is set up, be in the top of piston cavity all the time.Also can prevent simultaneously the rotation of piston body.

Under exhaust condition, when brake fluid enters brake cylinder casing and piston cavity, need carry out exhaust.Specifically, under the effect of hydraulic pressure exhaust pressure, be deposited in piston body 1 Inner Front End first cavity 3 and the air come-up at other position, air will be along the air vent 4 that is located on second cavity 9, rise in the air vent 6 that is located on the 3rd cavity 7, discharge brake piston inside along air vent 6 then, discharge by the exhaust bolt hole of cylinder body again, reach exhaust effect.The utility model also can reach the effect of exhaust by the method that vacuumizes.

Under initial entrucking state, the gap between piston body head end and braking plate, the brake disc is bigger, need carry out several times foot pedal and adjust its gap by hydraulic braking.Specifically, the hydraulic coupling promotion piston body 1 that is produced by foot pedal progressively moves ahead, and along with moving ahead of piston body 1, the stroke adjustment nut 10 that is contained in the piston body 1 moves forward thereupon.When the stroke of piston body 1 surpassed stroke adjustment nut 10 and stroke adjustment screw rod 12 screw the gap time, the reach of stroke adjustment nut 10 then can be subjected to the restriction of stroke adjustment screw rod 12.Stroke adjustment nut 10 makes wavy spring 15 be subjected to further compression under the effect of the thrust of jump ring 13 and stroke adjustment screw rod 12 pulling force, stroke adjustment nut 10 leaves the inner conical surface of second cavity 9, between form certain clearance, and stroke adjustment nut 10 relative piston bodies 1 rotate, the stroke adjustment nut 10 that exceeds thereby compensating piston body 1 moves forward and the stroke in stroke adjustment screw rod 12 gaps.Piston body 1 reach produces braking until compressing braking plate.After stroke adjustment nut 10 rotation is finished, abut again on the inner conical surface of second cavity 9 at the effect down stroke adjusting nut 10 of wavy spring 15 elastic force.Normal range (NR) is transferred in gap between stroke adjustment screw rod 12 and the stroke adjustment nut 10 automatically.

In when braking, two kinds of modes of braking of service brake and parking braking are arranged.Wherein, in the driving braking process, a pin pushes down on the pedal, and brake piston body 1 moves forward under action of hydraulic force, realizes service brake; After unclamping pedal, braking is removed, and piston body 1 leaves under the restoring force effect of rectangular loop (not marking among the figure) and the contacting of braking plate.Because the spacing of piston body 1 rollback is less than stroke adjustment screw rod 12 matching gap with stroke adjustment nut 10, so in piston body 1 reach and back off procedure, the 10 relative piston body 1 no any motions of stroke adjustment nut.At this moment, stroke adjustment nut 10 abuts against on the inner conical surface of piston second cavity 9.In the parking braking process, stroke adjustment screw rod 12 reach touches stroke adjustment nut 10 after covering the matching gap between itself and the stroke adjustment nut 10, under its axial force promotes, stroke adjustment nut 10 reach, and then promote piston body 1 and move ahead and compress braking plate, realize parking braking function.After parking braking was removed, stroke adjustment screw rod 12 retreated, and recovered its original and gap stroke adjustment nut 10.When the axial force that sheds on stroke adjusting screw rod 12, piston body 1 is rollback under the restoring force effect of rectangular loop.Equally, the spacing of piston body 1 rollback is less than the matching gap of stroke adjustment screw rod 12 and stroke adjustment nut 10, therefore in 1 reach of brake piston body and back off procedure, and the 10 relative piston body 1 no any motions of stroke adjustment nut.

Claims (6)

1. brake calipers brake piston mechanism after, it comprises piston body (1), stroke adjustment nut (10), wavy spring (15) and jump ring (13), and the inner chamber front end that it is characterized in that described piston body (1) is provided with small cylindrical first cavity (3) of stroke adjustment screw rod (12) head end in the time of can holding first dress state; The inner chamber middle part of piston body (1) also is provided with taper shape second cavity (9) that can hold stroke adjustment nut (10), and described second cavity (9) head and small cylindrical first cavity (3) afterbody join; The inner chamber mid-rear portion of piston body (1) is provided with cylindrical the 3rd cavity (7) that can hold wavy spring (15) and jump ring (13); The inner chamber afterbody of piston body (1) is provided with great circle cylindricality the 4th cavity (8).

2. brake calipers brake piston mechanism after according to claim 1, it is characterized in that having on described conical second cavity (9) at least one arc first air vent (4), have at least one arc second air vent (6) on cylindrical the 3rd cavity (7), described first air vent (4) and second air vent (6) join end to end.

3. brake calipers brake piston mechanism is characterized in that the front end of described piston body (1) is provided with at least one anti-rotation locating slot (2) after according to claim 1.

4. brake calipers brake piston mechanism is characterized in that the inner chamber afterbody of described piston body (1) is provided with jump ring groove (5) after according to claim 1.

5. according to claim 2 and 3 described back brake calipers brake piston mechanisms, it is characterized in that the position of described first air vent (4) and second air vent (6) is under the entrucking state, the piston cavity top that anti-rotation locating slot (2) is fixed.

6. according to claim 2 and 4 described back brake calipers brake piston mechanisms, it is characterized in that the degree of depth of the degree of depth of described second air vent (6) greater than jump ring groove (5).

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