CN212337976U

CN212337976U - Booster of hydraulic brake protection device

Info

Publication number: CN212337976U
Application number: CN202021396677.9U
Authority: CN
Inventors: 陈灵刚; 刘叶芝; 刘叶勇; 韩伟玉
Original assignee: Yuhuan Aoheng Machinery Co ltd
Current assignee: Yuhuan Aoheng Machinery Co ltd
Priority date: 2020-07-15
Filing date: 2020-07-15
Publication date: 2021-01-12
Anticipated expiration: 2030-07-15

Abstract

The utility model provides a hydraulic braking protection device booster belongs to mechanical technical field. It has solved the not high problem of current hydraulic pressure helping hand jar work efficiency. The booster of the hydraulic brake protection device comprises a cylinder body, a first piston and a pushing piece, wherein the inner end of the pushing piece extends into the cylinder body, a cylindrical inner cavity, an oil inlet hole and an oil return hole are formed in the first piston, a second piston extending into the inner cavity is further arranged in the cylinder body, a return spring is arranged in the inner cavity, a second sealing portion is arranged on the side portion of the second piston, the second piston can move under the action of the return spring and enables the second sealing portion to block the oil inlet hole, the oil return hole is communicated with one side, far away from the pushing piece, of the inner cavity, an oil passing channel is further formed in the second piston, the inlet and the outlet of the oil passing channel are respectively located on two sides of the second sealing portion, and the pushing piece can abut against the second piston and block the. The booster of the hydraulic braking protection device has the advantage of easier operation.

Description

Booster of hydraulic brake protection device

Technical Field

The utility model belongs to the technical field of machinery, a hydraulic braking protection device booster is related to.

Background

The hydraulic power cylinder generally comprises a cylinder body, a piston arranged in the cylinder body and a push rod of which the outer end is used for being connected with a vehicle pedal, wherein the piston divides the cylinder body into an oil inlet cavity, an oil return cavity and an oil outlet cavity, and the cylinder body is provided with an oil inlet, an oil return opening and an oil outlet which are respectively communicated with the oil inlet cavity, the oil return cavity and the oil outlet cavity. The piston is also provided with an oil passage which can communicate the oil inlet cavity with the oil return cavity. During the use, push the push rod and block the oil passageway in to the cylinder body, for the continuous oil feeding of oil feed chamber through external fuel feeding equipment, promote the piston through the assistance of oil pressure and remove, provide the helping hand for the piston promotes.

For example, the applicant designs a hydraulic cylinder and applied for chinese patent (application No. 201711263536.2; publication No. CN107830081A), the hydraulic cylinder includes a cylinder body having a liquid inlet and a liquid return port, a piston disposed in the cylinder body, and a rod-shaped pushing member, the liquid inlet and the liquid return port can communicate with each other through a liquid passage opened on the piston, the piston has a columnar liquid passing cavity, the liquid passing channel includes a liquid inlet channel opened on a side wall of the liquid passing cavity and capable of communicating the liquid passing cavity with the liquid inlet, an inner end of the pushing member has a liquid passing portion extending into the liquid passing cavity, the liquid passing portion can axially translate in the liquid passing cavity, and when the liquid passing portion is at different positions, a side portion of the liquid passing portion can partially block the liquid inlet channel or not block the liquid inlet channel to different degrees. When the hydraulic power-assisted cylinder is used, the pushing piece is pushed into the cylinder body, the liquid inlet channel is partially blocked, the liquid inlet speed is higher than the liquid outlet speed, and the oil which is discharged more can generate boosting force at the oil inlet cavity to assist the pushing of the piston.

However, under the same condition of external oil supply equipment, when the hydraulic power cylinder is used, the oil pressure increase speed of the oil inlet cavity is slightly slow, that is, the working efficiency is relatively low, so that the use requirements of partial equipment can be met, but the use requirements of the equipment with higher working efficiency requirements cannot be met.

SUMMERY OF THE UTILITY MODEL

The utility model aims at the above-mentioned problem that prior art exists, provide hydraulic braking protection device booster, solved the not high problem of current hydraulic power cylinder work efficiency.

The purpose of the utility model can be realized by the following technical proposal:

a booster of a hydraulic brake protection device comprises a cylinder body with an oil inlet and an oil return port, a first piston arranged in the cylinder body and a pushing piece with the inner end extending into the cylinder body, the first piston is internally provided with a columnar inner cavity, an oil inlet hole capable of communicating the oil inlet with the inner cavity and an oil return hole communicating the inner cavity with the oil return port, it is characterized in that a second piston extending into the inner cavity is also arranged in the cylinder body, a return spring is arranged in the inner cavity, the side part of the second piston is provided with a second sealing part, the second piston can move under the action of a return spring and enables the second sealing part to seal the oil inlet hole, the oil return hole is communicated with one side of the inner cavity far away from the pushing piece, an oil passing channel is further arranged in the piston II, an inlet and an outlet of the oil passing channel are respectively positioned on two sides of the sealing part II, and the pushing piece can abut against the second piston and block the oil passage when moving into the cylinder body.

When the pushing piece does not act, the external oil supply equipment conveys oil to the oil inlet of the cylinder body and enters the oil inlet of the first piston, and the second piston moves under the elastic action of the return spring and blocks the oil inlet through the second sealing part, so that the oil cannot enter the inner cavity of the first piston. When an operator pushes the pushing piece into the cylinder body, the pushing piece moves inwards to abut against the second piston and block the oil passage, the operator continues to apply a pushing force, the pushing piece pushes the second piston to overcome the elastic force of the reset spring to move towards one end far away from the pushing piece, the position of the second sealing portion is staggered with the position of the oil inlet hole, oil enters the inner cavity through the oil inlet hole, the inner cavity is columnar, the second sealing portion of the second piston can always abut against the inner wall of the first piston and is sealed in the moving process of the second piston, and the oil cannot flow from the gap between the first piston and the second piston to the direction of the oil return hole located at one side of the inner cavity far away from the pushing piece. The oil passing channel is blocked, oil can be accumulated on one sides of the first piston and the second piston, the oil pressure is improved along with the increase of the oil, and an auxiliary operator pushes the first piston to provide assistance for the use of the booster. When oil drainage is needed, the piston I, the piston II and the pushing piece reset, oil on one side of the piston I and one side of the piston II return through the opened oil passing channel, the opened oil return hole and the opened oil return opening, and the oil returns to the initial state.

In the using process, the oil inlet hole is sealed by the sealing part II of the piston II due to the fact that the external oil supply equipment is in an oil supply state, so that oil pressure at the oil inlet hole of the piston I communicated with the external oil supply equipment and the oil inlet hole of the cylinder body is increased, when the sealing part II moves and enables the oil inlet hole to be opened, oil can enter the piston I more quickly under the action of higher oil pressure, assistance can be provided for movement of the piston I more quickly, and the working efficiency is higher. In addition, set up piston one simultaneously and stretch into the piston two in the inner chamber for operating personnel can realize the on-off control of oil circuit through promoting the less piston two of volume when promoting the impeller, for directly promoting the great piston one of volume, the driving force demand is littleer, and the operation is lighter, and the removal of impeller is faster, and the work efficiency of booster is also higher. And the promotion of piston one can borrow the helping hand of oil pressure to promote more easily for the helping hand effect of whole booster is better.

In foretell hydraulic braking protection device booster, the oil through passageway includes along the axial of piston two runs through the axial hole of seting up and runs through and sets up the side opening two on the axial hole lateral wall, the side opening is two between sealing part two and impeller outer end, the inner lateral part of impeller has convex sealing part three, just the outside of sealing part three with the axial hole lateral part supports and leans on. The oil passing channel comprises an axial hole which is formed in a penetrating mode, the hole is convenient to form, the flow area of the oil passing channel can be enlarged as far as possible under the condition that the strength of the piston II is guaranteed, the flow rate and the flow rate of oil are increased, the working efficiency is improved, in addition, the weight of the piston II can be reduced due to the fact that the larger axial hole is formed, the requirement for the size of the pushing force when the pushing piece pushes is further reduced, and the boosting effect is improved.

In the booster of the hydraulic brake protection device, a cavity is formed between one side of the third sealing part, which is close to the outer end of the pushing part, and the inner wall of the cylinder body, and the second piston is further provided with a through hole for communicating the cavity and the inner cavity. When the pushing piece pushes the cylinder body, air in the inner cavity can quickly enter the cavity, so that pushing resistance caused by complete sealing of the cavity is avoided, the pushing piece moves faster, and the working efficiency is higher; when the pushing piece resets, the oil in the cavity is rapidly discharged through the through hole, the oil pressure on one reset side is reduced, the pushing piece can be rapidly reset, and the working efficiency of the booster is improved.

In the booster of the hydraulic braking protection device, the end part of the inner end of the pushing part is provided with an inwards concave hole, a third side hole penetrates through the side wall of the concave hole, and the third side hole is positioned between the third sealing part and the end part of the inner end of the pushing part. And the side hole III and the concave hole form another channel for oil discharge, so that the speed of oil discharge is increased, and the working efficiency is improved.

In the booster of the hydraulic brake protection device, the number of the oil return holes is at least two, an inlet of one oil return hole is opposite to the end face of the second piston, an inlet of at least one oil return hole is opposite to the side part of the second piston, and a radial hole penetrates through the side part of the second piston, which is close to the oil return hole. A plurality of oil return holes are formed in the first piston, radial holes are correspondingly formed in the second piston, oil discharge passages are increased, oil discharge speed is increased, and working efficiency is improved.

In the booster of the hydraulic brake protection device, one end of the first piston facing the pushing piece is provided with a protruding cylindrical supporting part, the inner wall of the supporting part is provided with a protruding blocking part, and the second piston abuts against the blocking part under the elastic force of the return spring and enables the second sealing part to block the oil inlet hole. The second piston is limited by the blocking part, and the second sealing part on the second piston can block the oil inlet hole under the condition of no movement.

In the booster of the hydraulic brake protection device, the side part of the support part is further provided with a boosting hole in a penetrating way. Oil in the inner cavity can be conveyed to the outer side of the first piston through the power assisting hole, and sufficient power assisting guarantee is provided for movement of the first piston.

In foretell hydraulic braking protection device booster, annular oil feed tank has still been seted up to the lateral wall of piston one, oil feed tank and inlet port intercommunication, and the axial width of oil feed tank is greater than the aperture of inlet port, all be provided with the sealing washer between piston one and the cylinder body inner wall of oil feed tank both sides. The aperture of the oil inlet is relatively small, the sealing part II is convenient to plug, and the communicating area of the oil inlet and the oil inlet can be enlarged due to the arrangement of the oil inlet groove.

In the booster of the hydraulic brake protection device, an overflow valve is connected between the oil inlet and the oil return port on the outer side of the cylinder body. The pressure is timely released through the overflow valve, and the problem that the service life of external oil supply equipment is influenced due to overhigh oil pressure at the oil inlet is avoided.

In the booster of the hydraulic brake protection device, two cavities are arranged in the cylinder body, the first piston, the second piston and the pushing piece are arranged in the two cavities, a balance hole communicated with the two cavities is further formed in the cylinder body, two ends of the balance hole are respectively located on the side portions of the two cavities, balance valves capable of opening and closing the balance hole are arranged at two ends of the balance hole, a valve core portion of each balance valve extends into the corresponding cavity, a cylindrical piston sleeve is further fixed on the first piston, and the piston sleeve can move along with the first piston to push the valve core of each balance valve to retract into the corresponding balance hole and open the corresponding balance hole.

Compared with the prior art, the booster of the hydraulic braking protection device has the following advantages:

1. this hydraulic braking protection device booster adopts often confined mode for when the impeller is not promoted, fluid is saved in oil inlet department, does not get into and circulates in the cylinder body, has improved the fluid of oil inlet department, when making the impeller promote, fluid can get into the cylinder body more fast and provide the helping hand, and work efficiency is high.

2. The structure that the axial hole and the concave hole at the inner end of the pushing piece are formed in the second piston enlarges the flow area for oil liquid discharge, increases the oil liquid discharge speed and further improves the working efficiency.

3. The structure that has set up piston one and piston two in this hydraulic braking protection device booster cooperates the impeller to use, and piston two is small, and weight is little, and required driving force demand reduces when operating personnel promotes piston two to remove through the impeller, and the operation is lighter.

Drawings

Fig. 1 is a schematic sectional view of a booster of the hydraulic brake protection device.

Fig. 2 is a partially enlarged view of the booster of the present hydraulic brake protection device.

FIG. 3 is an enlarged fragmentary view of the hydraulic brake protection device booster in use.

FIG. 4 is a schematic cross-sectional view of the hydraulic brake protection device at the booster relief valve.

In the figure, 1, a cylinder body; 1a, a cavity; 1b, an oil inlet; 1c, an oil return port; 2. a first piston; 2a, an inner cavity; 2b, oil inlet holes; 2c, an oil return hole; 2d, a support part; 2e, a power assisting hole; 2f, an oil inlet groove; 3. a pusher member; 3a, a third sealing part; 3b, concave holes; 3c, a side hole III; 4. a return spring; 5. a second piston; 5a, a second sealing part; 5b, an axial hole; 5c, a second side hole; 5d, radial holes; 5e, a through hole; 6. a blocking portion; 7. an overflow valve.

Detailed Description

The following are specific embodiments of the present invention and the accompanying drawings are used to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

The booster of the hydraulic braking protection device comprises a cylinder body 1 with an oil inlet 1b, an oil return port 1c and an oil outlet, wherein two cavities are arranged in the cylinder body 1, and a first piston 2, a second piston 5 and a pushing piece 3 are arranged in the two cavities. Still set up the balancing hole of two cavitys of intercommunication in the cylinder body 1, the both ends in two cavitys of this balancing hole are located the lateral part of two cavitys respectively, all are provided with the balanced valve that can open and close the balancing hole in the both ends in the balancing hole, and the case part of balanced valve stretches into in the cavity. And a cylindrical piston sleeve is further fixed on the piston I2 and can move along with the piston I2 to push the valve core of the balance valve to retract into the balance hole and open the balance hole. Because the structures of the two cavities in the cylinder body 1 are the same, the structure of one of the cavities is taken as an example for structural description.

As shown in fig. 1 and 2, the first piston 2 divides the cavity into an oil inlet cavity, an oil return cavity and an oil outlet cavity, the oil return cavity is communicated with the oil return port 1c, the oil outlet cavity is communicated with the oil outlet, and the balance hole is formed in the side portion of the oil outlet cavity. A first spring is arranged in the oil return cavity, two ends of the first spring are respectively abutted against the inner wall of the cylinder body 1 and the first piston 2, and the first piston 2 moves towards the direction of the oil inlet cavity under the action of the elastic force of the first spring.

Have in the piston 2 and be cylindric inner chamber 2a, run through on the lateral part of inner chamber 2a and seted up inlet port 2b, set up on the lateral wall of piston 2 and be annular inlet tank 2f of being of oil inlet 1b intercommunication, this inlet tank 2f bottom and inlet port 2b intercommunication, and the axial width of inlet tank 2f is greater than the aperture of inlet port 2b, all is provided with the sealing washer between the piston 2 of inlet tank 2f both sides and the 1 inner wall of cylinder body. And a plurality of oil return holes 2c for communicating the inner cavity 2a with the oil return cavity are formed in the piston I2. One end of the piston I2 facing the pushing piece 3 is provided with a protruding cylindrical supporting part 2d, and the end part of the supporting part 2d can be abutted against the inner wall of the cylinder body 1 by the piston I2 under the action of the elastic force of the spring I. The lateral part of the supporting part 2d is also provided with a plurality of boosting holes 2e for communicating the inner cavity 2a with the oil inlet cavity in a penetrating way. In the embodiment, the number of the oil return holes 2c is at least two, wherein an inlet of one oil return hole 2c is opposite to the end surface of the inner cavity 2a, and an inlet of at least one oil return hole 2c is opposite to the side part of the piston two 5 extending into the piston one 2.

The side part of the second piston 5 is provided with a convex sealing part two 5a, a return spring 4 is arranged between the front end of the second piston 5 and the first piston 2, the inner wall of the supporting part 2d is provided with a convex blocking part 6, the second piston 5 moves backwards under the elastic force of the return spring 4 to abut against the blocking part 6, and the sealing part two 5a blocks the oil inlet hole 2 b. An axial hole 5b is formed in the second piston 5 in a penetrating mode along the axial direction, a side portion of the second piston 5 is formed in a penetrating mode and provided with a second side hole 5c, the second side hole 5c is located between the second sealing portion 5a and the rear end of the second piston 5, and a radial hole 5d is further formed in the side portion of the second piston 5 in a penetrating mode and located between the front end and the second sealing portion 5 a. In this embodiment, the second sealing portion 5a includes an annular sealing groove formed in the outer side of the second piston 5, a first sealing ring with a circular cross section and a second sealing ring with a square cross section are disposed in the sealing groove, the second sealing ring is disposed on the outer side of the first sealing ring, and the outer side of the second sealing ring is tightly abutted to the sidewall of the inner cavity 2 a; the blocking portion 6 is an annular collar.

The inner end of the pushing piece 3 extends into an axial hole 5b of the piston II 5, a spring III is arranged between the pushing piece 3 and the piston II 5, and the pushing piece 3 moves towards the outer end under the action of the elastic force of the spring III. The side part of the inner end of the pushing piece 3 is provided with a convex sealing part three 3a, and the outer side of the sealing part three 3a is tightly abutted with the side part of the axial hole 5 b. The end part of the inner end of the pushing part 3 is provided with a concave hole 3b, the side wall of the concave hole 3b is provided with a side hole three 3c in a penetrating way, and the side hole three 3c is positioned between the sealing part three 3a and the end part of the inner end of the pushing part 3. A cavity 1a is formed between one side of the third sealing part 3a close to the outer end of the pushing part 3 and the inner walls of the second piston 5 and the cylinder body 1, and a through hole 5e for communicating the cavity 1a with the inner cavity 2a is further formed in the second piston 5. In this embodiment, the third sealing portion 3a has a structure similar to that of the second sealing portion 5a, and includes an annular sealing groove, a first sealing ring with a circular cross section and a second sealing ring with a square cross section are disposed in the annular sealing groove, the second sealing ring is disposed on the outer side of the first sealing ring, and the outer side of the second sealing ring is tightly abutted to the inner wall of the axial hole 5 b.

As shown in fig. 4, an overflow valve 7 is connected between an oil inlet 1b and an oil return port 1c on the outer side of the cylinder 1, a valve body of the overflow valve 7 is connected with the cylinder 1 into a whole, when the oil at the oil inlet 1b is too large, a valve core of the overflow valve 7 is jacked open, and the oil inlet 1b and the oil return port 1c are directly communicated under the condition that the first piston 2, the second piston 5 and the pushing member 3 are not operated, so that the oil circulates and returns to the oil tank. When the oil pressure is reduced, the overflow valve 7 is closed again, and a certain oil pressure is kept at the oil inlet 1 b.

When the pushing piece 3 does not act, the external oil supply equipment conveys oil to the oil inlet 1b of the cylinder body 1 and enters the oil inlet hole 2b of the first piston 2 through the oil inlet groove 2 f. Because the second sealing part 5a seals the oil inlet hole 2b, oil cannot enter the inner cavity 2a of the first piston 2. Original oil in the cylinder body 1 can be returned through the power-assisted hole 2e, the through hole 5e, the side hole II 5c, the axial hole 5b, the radial hole 5d, the oil outlet I, the oil return cavity and the oil return port 1 c.

When the operator pushes the pushing member 3 into the cylinder 1, as shown in fig. 4, the pushing member 3 moves inward against the second piston 5 against the elastic force of the third spring, and the third sealing portion 3a blocks the second side hole 5 c. The operator continues to apply the pushing force, and the piston II 5 synchronously moves inwards along with the pushing piece 3 against the elastic force of the return spring 4 until the inner end of the piston II 5 abuts against the piston I2. At the moment, the second sealing part 5a moves forwards, the oil inlet hole 2b is not plugged, oil enters the inner cavity 2a through the oil inlet hole 2b, the inner cavity 2a is columnar, the second sealing part 5a can always abut against and seal with the inner wall of the first piston 2 in the process that the second piston 5 moves, the oil cannot flow to the direction of the oil return hole 2c from the gap between the first piston 2 and the second piston 5, the side hole two 5c is plugged by the third sealing part 3a, the oil can only be accumulated in the rear half section of the inner cavity 2a, the oil flows to the oil inlet cavity through the power assisting hole 2e, the oil flows to the cavity 1a through the through hole 5e, the oil pressure is improved along with the increase of the oil, the auxiliary operator pushes the first piston 2, and power assisting is provided for the booster. In the moving process of the first piston 2, the position of the oil inlet hole 2b is gradually staggered with the oil inlet 1b, and oil inlet communication is achieved by means of the oil inlet groove 2 f. When the piston I2 continues to move to the oil inlet groove 2f and the oil inlet 1b is staggered, the oil inlet 1b can be directly communicated with the oil inlet cavity on the rear side of the piston I2 to achieve oil inlet assistance. In the present embodiment, the stiffness coefficients of the first spring, the return spring 4 and the third spring are reduced one by one.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein may be made by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Claims

1. A booster of a hydraulic brake protection device comprises a cylinder body (1) with an oil inlet (1b) and an oil return port (1c), a piston I (2) arranged in the cylinder body (1) and a pushing piece (3) with the inner end extending into the cylinder body (1), wherein a columnar inner cavity (2a), an oil inlet (2b) capable of communicating the oil inlet (1b) with the inner cavity (2a) and an oil return hole (2c) capable of communicating the inner cavity (2a) with the oil return port (1c) are arranged in the piston I (2), a piston II (5) extending into the inner cavity (2a) is further arranged in the cylinder body (1), a reset spring (4) is arranged in the inner cavity (2a), a sealing part II (5a) is arranged on the side part of the piston II (5), the piston II (5) can move under the action of the reset spring (4) and enables the sealing part II (5a) to plug the oil inlet (2b), the oil return hole (2c) is communicated with one side, far away from the pushing piece (3), of the inner cavity (2a), an oil passing channel is further formed in the piston II (5), an inlet and an outlet of the oil passing channel are respectively located on two sides of the sealing portion II (5a), and the pushing piece (3) can abut against the piston II (5) and block the oil passing channel when moving towards the cylinder body (1).

2. The booster of the hydraulic brake protection device according to claim 1, wherein the oil passing channel comprises an axial hole (5b) formed in the axial direction of the second piston (5) in a penetrating manner and a second side hole (5c) formed in the side wall of the axial hole (5b) in a penetrating manner, the second side hole (5c) is located between the second sealing portion (5a) and the outer end of the pushing member (3), the side portion of the inner end of the pushing member (3) is provided with a third protruding sealing portion (3a), and the outer side of the third sealing portion (3a) abuts against the side portion of the axial hole (5 b).

3. The booster of the hydraulic brake protection device according to claim 2, wherein a cavity (1a) is formed between one side of the third sealing part (3a) close to the outer end of the pushing part (3) and the inner wall of the cylinder body (1), and a through hole (5e) for communicating the cavity (1a) with the inner cavity (2a) is formed in the second piston (5).

4. The booster of the hydraulic brake protection device according to claim 2 or 3, wherein the inner end of the pushing member (3) is provided with a concave hole (3b), a side hole III (3c) is formed in the side wall of the concave hole (3b) in a penetrating manner, and the side hole III (3c) is located between the sealing part III (3a) and the inner end of the pushing member (3).

5. The booster of the hydraulic brake protection device according to claim 2 or 3, wherein the number of the oil return holes (2c) is at least two, an inlet of one oil return hole (2c) is opposite to the end face of the second piston (5), an inlet of at least one oil return hole (2c) is opposite to the side portion of the second piston (5), and a radial hole (5d) penetrates through the side portion of the second piston (5) close to the oil return hole (2 c).

6. The booster of the hydraulic brake protection device according to claim 1, 2 or 3, wherein one end of the first piston (2) facing the pushing piece (3) is provided with a convex cylindrical supporting part (2d), the inner wall of the supporting part (2d) is provided with a convex stopping part (6), and the second piston (5) is abutted against the stopping part (6) under the elastic force of the return spring (4) and enables a sealing part two (5a) to block the oil inlet hole (2 b).

7. The booster of claim 6, wherein the support portion (2d) is further perforated with a boosting hole (2e) at a side thereof.

8. The booster of the hydraulic brake protection device according to claim 1, 2 or 3, wherein an annular oil inlet groove (2f) is further formed in the outer side wall of the first piston (2), the oil inlet groove (2f) is communicated with the oil inlet hole (2b), the axial width of the oil inlet groove (2f) is larger than the aperture of the oil inlet hole (2b), and sealing rings are arranged between the first piston (2) on two sides of the oil inlet groove (2f) and the inner wall of the cylinder body (1).

9. The booster according to claim 1, 2 or 3, characterized in that a relief valve (7) is connected between the oil inlet (1b) and the oil return (1c) on the outside of the cylinder (1).

10. The booster of the hydraulic brake protection device according to claim 1, 2 or 3, wherein the cylinder body (1) has two cavities, the first piston (2), the second piston (5) and the pushing member (3) are disposed in the two cavities, the cylinder body (1) is further provided with a balance hole communicating the two cavities, two ends of the balance hole are respectively located at lateral portions of the two cavities, two ends of the balance hole are both provided with a balance valve capable of opening and closing the balance hole, a valve core portion of the balance valve extends into the cavity, the first piston (2) is further fixed with a cylindrical piston sleeve, and the piston sleeve can move along with the first piston (2) to push the valve core of the balance valve to retract into the balance hole and open the balance hole.