A brake master cylinder assembly

Abstract

This invention discloses a brake master cylinder assembly, aiming to solve the problem of poor sealing performance between the piston and the master cylinder wall in the prior art. The invention solves the above-mentioned technical problem through the following technical solution: The master cylinder has an internal mounting hole; a first piston and a second piston are sequentially arranged from the outside to the inside of the mounting hole; a first sealed cavity is formed between the first piston and the second piston, and a second sealed cavity is formed between the second piston and the mounting hole; a first oil outlet is provided in the first sealed cavity and on the side wall of the mounting hole, and two first sealing grooves are provided on both sides of the first oil outlet; a first sealing ring is provided in each of the two first sealing grooves; a second oil outlet is provided in the second sealed cavity and on the side wall of the mounting hole, and two second sealing grooves are provided on both sides of the second oil outlet; a second sealing ring is provided in each of the two second sealing grooves. The two second sealing grooves on both sides of the first and second oil outlets ensure the stability of braking performance.

Description

Technical Field

[0001] This invention relates to the field of automotive parts technology, and more specifically, to a brake master cylinder assembly. Background Technology

[0002] Electro-hydraulic braking systems, also known as brake-by-wire systems, offer numerous advantages over traditional braking systems and are therefore widely used in modern motor vehicles. Like traditional braking systems, the master cylinder remains a crucial component. Its function is to push hydraulic fluid into the brake calipers via the piston in the master cylinder, thereby achieving braking during vehicle operation.

[0003] Traditional brake master cylinders consist of a first piston and a second piston. Braking force is generated by the movement of the first piston and the second piston within the first and second chambers, respectively. However, when the brake pedal applies braking force to the push rod, the pressure inside the master cylinder increases. This increased pressure affects the sealing performance between the piston and the side wall of the master cylinder, leading to oil leakage and affecting braking performance, potentially causing very serious accidents. Summary of the Invention

[0004] This invention overcomes the shortcomings of poor sealing performance between the piston and the master cylinder wall in the prior art, and provides a brake master cylinder assembly with good sealing performance, which can ensure the sealing performance between the piston and the side wall of the master cylinder, thereby ensuring the stability of braking performance and providing a stable braking force for the vehicle.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a brake master cylinder assembly, comprising: a master cylinder, wherein a mounting hole is provided inside the master cylinder; a first piston and a second piston are sequentially arranged from the outside to the inside of the mounting hole;

[0006] A first sealed cavity is formed between the first piston and the second piston, and a second sealed cavity is formed between the second piston and the mounting hole;

[0007] A first oil outlet is provided in the first sealed cavity and on the side wall of the mounting hole. Two first sealing grooves are provided on both sides of the first oil outlet. A first sealing ring is provided in each of the two first sealing grooves.

[0008] A second oil outlet is provided inside the second sealed cavity and on the side wall of the mounting hole. Two second sealing grooves are provided on both sides of the second oil outlet. A second sealing ring is provided in each of the two second sealing grooves.

[0009] This invention improves the sealing performance between the first piston and the mounting hole by providing first sealing grooves on both sides of the first oil outlet and by providing a first sealing ring with a first groove on the first sealing ring. This allows the first sealing ring to expand towards both sides of the first groove under the pressure of the oil itself. Similarly, by providing two second sealing grooves on both sides of the second oil outlet and by providing a second groove on the second sealing ring, the sealing performance between the second piston and the mounting hole is also improved. This allows oil to output stable braking force from the first and second oil outlets, thereby ensuring the stability of braking performance.

[0010] Preferably, the end faces of the two first sealing rings are provided with a first groove in the circumferential direction; the first grooves of the two first sealing rings face the bottom of the mounting hole.

[0011] When the oil in the first sealed cavity leaks into the first groove, the oil's own pressure causes the first sealing ring to expand towards both sides of the first groove, thereby improving the effect between the first piston and the side wall of the mounting hole.

[0012] Preferably, the end faces of the two second sealing rings are provided with second grooves in the circumferential direction, and the direction of the second grooves of the two second sealing rings is opposite to that of the second oil outlet.

[0013] When oil leaks into the second sealing ring in the second sealing groove, the second sealing ring expands towards both sides of the second groove due to its own pressure, thereby improving the effect between the second piston and the side wall of the mounting hole.

[0014] Preferably, mounting grooves are provided on the outer circumference of both the first piston and the second piston, and sealing rubber rings are embedded in the mounting grooves.

[0015] The sealing rubber ring further improves the sealing effect.

[0016] Preferably, a guide structure is provided between the first piston and the second piston, and between the second piston and the bottom of the mounting hole. The guide structure includes a guide sleeve and a guide rod. A guide hole is provided inside the guide sleeve. One end of the guide rod is fixedly connected to the end of the first piston or the second piston away from the opening of the mounting hole. The other end of the guide rod is slidably disposed in the guide hole. A sliding head is provided at the end of the guide rod located in the guide hole. A limiting retaining ring is provided at the opening of the guide hole to restrict the sliding head from sliding out.

[0017] The guide rod and guide sleeve work together to make the first piston or the second piston slide more stably in the mounting hole.

[0018] Preferably, a guide structure is provided between the first piston and the second piston, and between the second piston and the bottom of the mounting hole. The guide structure includes a guide sleeve and a guide rod. A guide hole is provided inside the guide sleeve. One end of the guide rod is fixedly connected to the end of the first piston or the second piston away from the opening of the mounting hole. The other end of the guide rod is slidably disposed in the guide hole. A sliding head is provided at the end of the guide rod located in the guide hole. The sliding head is in close contact with the inner sidewall of the guide hole. A limiting retaining ring is provided at the opening of the guide hole to restrict the sliding head from sliding out.

[0019] A sealing cavity is provided inside the sealing rubber ring, an oil guide pipe is provided inside the guide rod, and a side wall hole communicating with the oil guide pipe is provided on the side wall of the guide head; both the first piston and the second piston are provided with piston pipes communicating with the oil guide pipe and the sealing cavity.

[0020] An oil leakage groove is provided on the side wall of the guide sleeve away from the guide rod, and the position of the oil leakage groove corresponds to the side wall hole.

[0021] When the pedal is pressed with great force, the braking force suddenly increases. At this time, the sliding head slides to the position corresponding to the guide hole and the oil leakage groove, so that the side wall hole and the oil leakage groove are connected. This allows the oil in the first or second sealed cavity to enter the sealed cavity through the oil leakage groove, the side wall hole, the oil guide pipe, and the piston pipe. This increases the pressure in the sealed cavity, which in turn causes the sealing rubber ring to expand. This causes the sealing rubber ring to tightly abut against the side wall of the mounting hole and the side wall of the first or second piston, effectively preventing oil leakage due to the sudden increase in pressure in the first and second sealed cavities.

[0022] Preferably, a first oil outlet is provided in the first sealing cavity, and a second oil outlet is provided in the second sealing cavity.

[0023] Preferably, a dust plug is provided between the first oil outlet and the second oil outlet.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] (1) It has good sealing performance, which can ensure the sealing performance between the piston and the side wall of the master cylinder, thereby ensuring the stability of braking performance and providing a stable braking force for the car.

[0026] (2) It effectively prevents oil leakage caused by a sudden increase in pressure in the first and second sealed chambers, and further provides a stable braking force for the car. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of the present invention;

[0028] Figure 2 yes Figure 1A magnified view of a portion of region A in the middle;

[0029] Figure 3 yes Figure 1 A magnified view of a portion of region B in the middle;

[0030] Figure 4 This is a top view of the present invention;

[0031] Figure 5 yes Figure 4 A cross-sectional view along the AA direction;

[0032] Figure 6 yes Figure 4 Sectional view in the middle BB direction

[0033] In the diagram: 1. Main cylinder, 11. Mounting hole, 111. First sealed chamber, 112. Second sealed chamber, 113. First oil outlet, 114. Second oil outlet, 12. First oil outlet, 13. Second oil outlet, 14. Dust plug.

[0034] 2. First piston;

[0035] 3. Second piston;

[0036] 4. First sealing groove; 41. Front first sealing groove; 42. Rear first sealing groove; 43. First sealing ring; 431. First groove.

[0037] 5. Second sealing groove; 51. Front second sealing groove; 52. Rear second sealing groove; 53. Second sealing ring; 531. Second groove.

[0038] 6. Mounting groove; 61. Sealing rubber ring; 62. Sealing cavity;

[0039] 7. Guide structure; 71. Guide rod; 711. Oil guide pipe; 72. Guide sleeve; 721. Guide hole; 722. Limiting ring; 723. Oil leakage groove; 73. Sliding head; 731. Side wall hole; 74. Piston pipe. Detailed Implementation

[0040] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0041] Example 1: Refer to Figures 1 to 6 As shown, a brake master cylinder assembly includes: a master cylinder 1, the master cylinder 1 having a mounting hole 11 inside; a first piston 2 and a second piston 3 are sequentially arranged from the outside to the inside of the mounting hole 11, a transmission rod is fixedly connected to the end of the first piston 2 away from the second piston 3; a first spring abuts between the first piston 2 and the second piston 3, and a second spring abuts between the second piston 2 and the bottom of the mounting hole 11.

[0042] A first sealed cavity 111 is formed between the first piston 2 and the second piston 3, and a second sealed cavity 112 is formed between the second piston 3 and the mounting hole 11.

[0043] A first oil outlet 113 is provided in the first sealed cavity 111 and on the side wall of the mounting hole 11. Two first sealing grooves 4 are provided on both sides of the first oil outlet 113. A first sealing ring 43 is provided in each of the two first sealing grooves 4. The two first sealing grooves 4 are a front first sealing groove 41 and a rear first sealing groove 42. The front first sealing groove 41 is provided at the end away from the opening of the mounting hole 11, and the rear first sealing groove 42 is provided on the side wall of the opening near the mounting hole 11.

[0044] A second oil outlet 114 is provided in the second sealed cavity 112 and on the side wall of the mounting hole 11. Two second sealing grooves 5 are provided on both sides of the second oil outlet 114. A second sealing ring 53 is provided in each of the two second sealing grooves 5. The two second sealing grooves 5 include a front second sealing groove 51 and a rear second sealing groove 52.

[0045] Both first sealing rings 43 have a first groove 431 on the circumferential direction of their end faces; the first grooves 431 of the two first sealing rings 41 face the bottom of the mounting hole 11.

[0046] The end faces of the two second sealing rings 53 are provided with second grooves 531 in the circumferential direction, and the orientation of the second grooves 531 of the two second sealing rings 53 is opposite to that of the second oil outlet 114.

[0047] A guide structure 7 is provided between the first piston 2 and the second piston 3, and between the second piston 3 and the bottom of the mounting hole 11. The guide structure 7 includes a guide sleeve 72 and a guide rod 71. A guide hole 721 is provided inside the guide sleeve 72. One end of the guide rod 71 is fixedly connected to the end of the first piston 2 or the second piston 3 away from the opening of the mounting hole 11. The other end of the guide rod 71 is slidably disposed in the guide hole 721. A sliding head 73 is provided at the end of the guide rod 71 located in the guide hole 721. A limiting retaining ring 722 is provided at the opening of the guide hole 721 to restrict the sliding head 73 from sliding out.

[0048] The first sealing cavity 111 is provided with a first oil outlet 12, and the second sealing cavity 112 is provided with a second oil outlet 13.

[0049] Dust plugs 14 are provided between the first oil outlet 12 and the second oil outlet 13.

[0050] In this embodiment, during operation, the transmission rod is subjected to the force of the pedal, causing the first piston 2 and the second piston 3 to move into the mounting hole 11, thereby increasing the pressure in the first sealed cavity 111 and the second sealed cavity 112. In order to improve the sealing performance between the first piston 2 and the second piston 3 and the side wall of the mounting hole 11, a front first sealing groove 41 and a rear second sealing groove 42 are provided on both sides of the first oil outlet hole 113. At the same time, the first groove 431 on the first sealing ring 43 in the front first sealing groove 41 and the rear second sealing groove 42 is oriented towards the bottom of the mounting hole 11. When the oil in the first sealed cavity 111 leaks into the first groove 431, the first sealing ring 43 expands towards both sides of the first groove 431 due to the pressure of the oil itself, thereby improving the effect between the first piston 2 and the side wall of the mounting hole 11.

[0051] Similarly, when oil leaks from the first sealing cavity 111 into the second sealing ring 53 in the rear second sealing groove 52, the second sealing ring 53 expands towards both sides of the second groove 531 due to its own pressure, thereby improving the effect between the second piston 3 and the sidewall of the mounting hole 11; when oil leaks from the second sealing cavity 112 into the second sealing ring 53 in the front second sealing groove 51, the second sealing ring 53 expands towards both sides of the second groove 531 due to its own pressure, thereby improving the effect between the second piston 3 and the sidewall of the mounting hole 11.

[0052] This invention improves the sealing performance between the first piston 2 and the mounting hole 111 by providing first sealing grooves 4 on both sides of the first oil outlet 113, and by providing first sealing rings 43 with first grooves 431 on the first sealing rings 43. Similarly, by providing two second sealing grooves 5 on both sides of the second oil outlet 114 and providing second grooves 531 on the second sealing rings 53, the sealing performance between the second piston 3 and the mounting hole 11 is also improved. This allows oil to output stable braking force from the first oil outlet 12 and the second oil outlet 13, thereby ensuring the stability of braking performance.

[0053] Example 2: This example is similar in structure to Example 1, except that, in order to prevent a sudden increase in pressure in the first sealed chamber 111 and the second sealed chamber 112 due to emergency braking, which would cause oil to leak out from the side wall of the first piston 2 or the second piston 3 and the mounting hole 11, the relevant structure has been improved. Specifically:

[0054] Both the first piston 2 and the second piston 3 are provided with mounting grooves 6 on their outer circumferences, and sealing rubber rings 61 are embedded in the mounting grooves 6.

[0055] The sliding head 73 is in close contact with the inner wall of the guide hole 721. A sealing cavity 62 is provided inside the sealing rubber ring 61. An oil guide pipe 711 is provided inside the guide rod 71. A side wall hole 731 communicating with the oil guide pipe 711 is provided in the circumferential direction of the side wall of the guide head 73. Both the first piston 2 and the second piston 3 are provided with piston pipes 74 that communicate with the oil guide pipe 711 and the sealing cavity 62.

[0056] An oil leakage groove 723 is provided on the side wall of the guide sleeve 72 away from the guide rod 71, and the position of the oil leakage groove 723 corresponds to the side wall hole 731.

[0057] The working principle of this embodiment is as follows: When the pedal is pressed with a very large force and the braking force suddenly increases, the sliding head 73 slides to the position corresponding to the guide hole 721 and the oil leakage groove 723, so that the side wall hole 731 is connected to the oil leakage groove 723. This allows the oil in the first sealed cavity 111 or the second sealed cavity 112 to enter the sealed cavity 62 through the oil leakage groove 723, the side wall hole 731, the oil guide pipe 711, and the piston pipe 74. This increases the pressure in the sealed cavity 62, causing the sealing rubber ring 61 to expand. Consequently, the sealing rubber ring 61 tightly abuts against the side wall of the mounting hole 11 and the side wall of the first piston 2 or the second piston 3, effectively preventing oil leakage caused by a sudden increase in pressure in the first sealed cavity 111 and the second sealed cavity 113. When the pressure in the first sealed cavity 111 and the second sealed cavity 113 returns to its original position, the side wall hole 731 of the sliding head 73 abuts against the side wall of the guide hole 721, sealing the side wall hole 731 and keeping the pressure in the sealed cavity 62 constant. Therefore, through this arrangement, the sealed cavity 62 will only expand after the pressure in the first sealed cavity 111 and the second sealed cavity 113 increases significantly; under normal braking force, the sealed cavity 62 will not be used for auxiliary sealing. Therefore, the location of the oil leakage groove 723 needs to be a certain distance from the opening of the guide hole 721, and the length of this distance is set according to the actual situation.

[0058] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications may be made without departing from the technical solutions described in the claims.

Claims

1. A brake master cylinder assembly characterized by, The utility model relates to a master cylinder, which comprises: a master cylinder having an installation hole in the interior thereof; the installation hole is sequentially provided with a first piston and a second piston from the outside to the inside; a first closed cavity is formed between the first piston and the second piston, and a second closed cavity is formed between the second piston and the installation hole; a first oil outlet hole is arranged in the first closed cavity and on the side wall of the installation hole, and two first sealing grooves are arranged on both sides of the first oil outlet hole; a first sealing ring is arranged in each of the two first sealing grooves; a second oil outlet hole is arranged in the second closed cavity and on the side wall of the installation hole, and two second sealing grooves are arranged on both sides of the second oil outlet hole; a second sealing ring is arranged in each of the two second sealing grooves; an installation groove is arranged in the circumferential direction of the outer side of the first piston and the second piston, and a sealing rubber ring is embedded in the installation groove; a guide structure is arranged between the first piston and the second piston, between the second piston and the bottom of the installation hole, and comprises a guide sleeve and a guide rod; a guide hole is arranged in the guide sleeve; one end of the guide rod is fixedly connected to the first piston or the second piston away from the end of the installation hole; the other end of the guide rod is slidably arranged in the guide hole; a sliding head is arranged at the end of the guide rod in the guide hole, and the sliding head is in close contact with the inner side wall of the guide hole; a sealing cavity is arranged in the sealing rubber ring; an oil guide pipeline is arranged in the guide rod; a side wall hole is arranged in the side wall of the guide head and communicates with the oil guide pipeline; and a piston pipeline that communicates the oil guide pipeline and the sealing cavity is arranged in the first piston and the second piston.

2. The brake master cylinder assembly of claim 1, wherein A first groove is arranged in the circumferential direction of the end face of each of the two first sealing rings; and the first grooves of the two first sealing rings face the bottom of the installation hole.

3. The brake master cylinder assembly of claim 1, wherein, A second groove is arranged in the circumferential direction of the end face of each of the two second sealing rings; and the second grooves of the two second sealing rings face away from the second oil outlet hole.

4. The brake master cylinder assembly of claim 1, wherein, A limiting stop ring is arranged at the hole of the guide hole to limit the sliding head from sliding out.

5. The brake master cylinder assembly of claim 4, wherein, An oil leakage groove is arranged in the side wall of the guide sleeve away from the guide rod, and the position of the oil leakage groove corresponds to the side wall hole.

6. The brake master cylinder assembly according to claim 1 or 2 or 3 or 4 or 5, characterized in that A first oil outlet is arranged in the first sealing cavity, and a second oil outlet is arranged in the second sealing cavity.

7. The brake master cylinder assembly of claim 6, wherein, A dustproof plug is arranged between the first oil outlet and the second oil outlet.

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