A brake transmission device for reducing the idle travel of a brake system

Abstract

The invention discloses a brake transmission device for reducing the idle stroke of a brake system, a housing, a large bushing fixed in the housing, a large piston arranged in the inner hole of the large bushing, a large leather cup arranged between the large piston and the large bushing, and the large leather cup can move with the large piston in the inner hole of the large bushing; one end of a small piston is fixed in the housing through a push rod assembly, and the other end passes through the inner hole of the large piston, a small leather cup is also arranged at the other end of the small piston, and can move with the other end of the small piston in the inner hole of the small bushing fixed in the housing, a return spring is arranged between the large piston and the large bushing, a large spring is arranged between the large piston and the push rod assembly, and oil holes are arranged radially on the large bushing and the small bushing. The two-stage piston structure is adopted, which can effectively reduce the moving distance of the large piston.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic brakes of a wheel brake system, and in particular to a brake transmitter for reducing the idle travel of a brake system. Background Art

[0002] my country's hydraulic mechanical aircraft wheel brake system is mainly composed of wheel brake transmitter, brake distribution valve, and brake device. The driver's foot pedal is connected to the wheel brake transmitter. The driver transmits the control force to the brake transmitter through the foot pedal, pushing the brake transmitter piston to move the oil to the brake distribution valve to open the distribution valve. The distribution valve reduces the pressure of the high-pressure oil and then connects it to the brake device for braking. Since the brake transmitter and brake distribution valve products themselves have idle travel, the oil compression between the transmitter and the distribution valve, and between the distribution valve and the brake device, and the expansion and deformation of the hose, etc. all require consumption of oil. When braking, after the driver operates the foot pedal to eliminate the idle travel of the transmitter and the distribution valve itself, the system needs to move a certain distance before it can build pressure. Different brake transmitter structures give the driver completely different idle travel feelings and control force. This puts high demands on the structural design of the transmitter.

[0003] At present, the transmission structure in my country is all in the form of a first-stage piston, which is mainly different in the size of the piston area, but both have certain defects. Although the large-area piston structure has a smaller idle stroke, the operating force is larger when braking. Although the small-area piston structure has a smaller braking operating force, the driver needs to step on it for a long distance to feel the pressure. The idle stroke of the system accounts for nearly one-third of the total stroke of the transmission, and the driver's operating experience is poor. Summary of the invention

[0004] Purpose of the Invention

[0005] In view of the above problems, the present invention provides a brake transmission device for reducing the idle travel of a brake system.

[0006] Inventing technical solutions

[0007] A brake transmission for reducing the idle stroke of a brake system comprises a shell, a large bushing fixed in the shell, a large piston arranged in the inner hole of the large bushing, a large leather cup arranged between the large piston and the large bushing, and the large leather cup can move in the inner hole of the large bushing with the large piston; one end of a small piston is fixed in the shell by a push rod assembly, and the other end passes through the inner hole of the large piston, a small leather cup is also arranged at the other end of the small piston, and can move in the inner hole of the small bushing fixed in the shell with the other end of the small piston, a return spring is arranged between the large piston and the large bushing, a large spring is arranged between the large piston and the push rod assembly, and oil holes are arranged radially on the large bushing and the small bushing.

[0008] Preferably, the push rod assembly, the small piston, the large piston, the large bushing, the large leather cup, the small leather cup, and the small bushing 6 are coaxial.

[0009] Preferably, the push rod assembly is threadedly connected to one end of the small piston.

[0010] Preferably, one end of the large bushing is limited by a positioning sleeve arranged in the shell, and the other end is limited by the shell.

[0011] Preferably, the positioning sleeve is threadedly connected to the inner hole of the shell, an annular groove is provided on the outer circumferential surface of the middle part of the positioning sleeve, an oil hole is provided on the annular groove, and an oil filling port is provided on the shell, and oil can enter the inner cavity of the shell through the oil filling port and the oil filling port on the annular groove.

[0012] Preferably, an output cavity is also provided on the shell, and the output cavity is communicated with the inner hole of the small bushing.

[0013] Preferably, the small piston and the large piston are clearance-matched and a sealing ring three is provided between the small piston and the large piston.

[0014] Preferably, the initial elastic force of the large spring is greater than the initial elastic force of the return spring and is greater than the sum of the liquid pressure exerted on the large piston when it moves to the extreme position, the elastic force of the return spring, the friction between the large leather cup and the inner hole of the large bushing, the friction between the small leather cup and the inner hole of the small bushing, the sealing friction of the sealing ring and the small piston.

[0015] Preferably, sealing rings are provided between the large bushing and the housing, between the small bushing and the housing, and between the push rod assembly and the positioning sleeve.

[0016] The advantages of the present invention are as follows: a two-stage piston structure is adopted, a large piston chamber is used to eliminate the system idle stroke, and a small piston chamber is used for braking. The moving distance of the large piston can be effectively reduced while the brake distribution valve, brake device, and pipeline system remain unchanged, thereby reducing the idle stroke of the system. Moreover, since the small piston chamber works during braking and the hydraulic force is relatively small, the structure can achieve the beneficial effect of reducing the idle stroke of the brake system while meeting the driver's operating force requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a schematic structural diagram of a brake transmitter for reducing idle travel of a brake system.

[0018] In the figure: 1-push rod assembly, 2-positioning sleeve, 3-return spring, 4-large bushing, 5-seal ring one, 6-small bushing, 7-seal ring two, 8-housing, 11-push rod, 12-large spring, 13-small piston, 14-large piston, 15-seal ring three, 16-large leather cup, 17-small leather cup, 141-limiting step, 41-oil hole, 61-end groove, 62-oil hole. DETAILED DESCRIPTION

[0019] The present invention is achieved through the following technical solutions.

[0020] like Figure 1 , a brake transmission device for reducing the idle stroke of a brake system, a housing 8, one end of a large bushing 4 is limited by a positioning sleeve 2 arranged in the housing 8, and the other end is limited by the housing 8. The positioning sleeve 2 is threadedly connected to the inner hole of the housing 8, an annular groove is provided on the outer circumferential surface of the middle part of the positioning sleeve 2, an oil hole is provided on the annular groove, and an oil filling port is provided on the housing 8, and oil can enter the inner cavity of the housing 8 through the oil filling port and the oil filling port on the annular groove.

[0021] The large piston 14 is arranged in the inner hole of the large bushing 4, and a large leather cup 16 is arranged between the large piston 14 and the large bushing 4, and the large leather cup 16 can move with the large piston 14 in the inner hole of the large bushing 4; one end of the small piston 13 is threadedly connected with the push rod assembly 1, and the other end passes through the inner hole of the large piston 14, and a small leather cup 17 is also arranged at the other end of the small piston 13, and an annular step is arranged on the outer circumferential surface of the small piston 13 between the small leather cup 17 and the large piston 14, and the small leather cup 17 can move with the other end of the small piston 13 in the inner hole of the small bushing 6, and the small bushing 6 is limited by the housing 8 at one end away from the small piston 13, and a return spring 3 is arranged between the large piston 14 and the large bushing 4, and a large spring 12 is arranged between the large piston 14 and the push rod assembly 1. The maximum outer diameter of the large piston 14 is smaller than the inner diameter of the positioning sleeve 2, and the small piston 13 and the large piston 14 are clearance-matched, and a sealing ring 3 15 is arranged between the small piston 13 and the large piston 14. The large bushing 4 and the small bushing 6 are both provided with oil holes in the radial direction. The push rod assembly 1, the small piston 13, the large piston 14, the large bushing 4, the large leather cup 16, the small leather cup 17, and the small bushing 6 are coaxial. The push rod assembly 1 passes through the inner hole of the positioning sleeve 2 and is limited by the annular step on the outer circumferential surface of the push rod assembly 1. The housing 8 is also provided with an output cavity, which is connected to the inner hole of the small bushing 6.

[0022] The initial elastic force of the large spring 12 is greater than the initial elastic force of the return spring 3 and is greater than the sum of the liquid pressure exerted on the large piston 14 when it moves to the extreme position, the elastic force of the return spring 3, the friction between the large leather cup 16 and the inner hole of the large bushing 4, the friction between the small leather cup 17 and the inner hole of the small bushing 6, and the sealing friction between the sealing ring 15 and the small piston 13.

[0023] Sealing rings are arranged between the large bushing 4 and the housing 8 , between the small bushing 6 and the housing 8 , and between the push rod assembly 1 and the positioning sleeve 2 .

[0024] The large piston 14, the large leather cup 16, and the large bushing 4 form a large piston cavity, and the small piston 13, the small leather cup 17, and the small bushing 6 form a small piston cavity. The large piston cavity and the small piston cavity form a piston cavity structure with two-stage piston sealing. The oil hole on the small bushing 6 can connect the large piston cavity and the small piston cavity, and the oil hole on the large bushing 4 can connect the large piston cavity and the inner cavity of the housing.

[0025] Working process: In the initial state, since the large bushing 4 and the small bushing 6 are provided with oil holes, the oil fills the inside of the large spring, the large piston cavity and the small piston cavity. When the operating force begins to be applied, since the elastic force of the large spring 12 is greater than the elastic force of the return spring 3, the large spring 12 is not compressed under the operating force, and the return spring 3 is compressed. The push rod assembly 1 pushes the large spring 12, the large piston 14, and the small piston 13 to move as a whole. When the large leather cup 16 blocks the oil hole on the large bushing 4, the inner cavity of the housing where the large spring is located is disconnected from the large piston cavity, which eliminates the idle stroke of the transmission itself. Continue to push the push rod assembly 1 to eliminate the output oil. The idle stroke caused by the distribution valve, brake device, system oil compression, hose deformation, etc., until the limit step 141 on the outer circumferential surface of the large piston 14 contacts the large bushing 4 for a limit, the large piston 14 stops moving, and the oil holes on the small bushing 6 are closed one after another. Due to the sum of the liquid pressure exerted on the large piston 14 when it moves to the extreme position due to the large spring 12, the elastic force of the return spring 3, the friction between the large leather cup 16 and the inner hole of the large bushing 4, the friction between the small leather cup 17 and the inner hole of the small bushing 6, and the sealing friction between the sealing ring 3 15 and the small piston 13, the large piston 12 will not retreat. The oil output volume at this stage is equivalent to the liquid volume output by the large piston 14. Therefore, under the condition that the brake distribution valve, brake device and piping system remain unchanged, the moving distance of the large piston can be effectively reduced, thereby reducing the idle stroke of the system. Then, the push rod assembly 1 is pushed continuously, the large spring 12 works, and the push rod assembly 1 pushes the small piston 13 to compress the oil and output the specified pressure for braking. In this stage, since the final braking pressure only acts on the small piston 13, the operating force during braking is effectively reduced. That is, the product adopts a two-stage piston chamber structure to provide oil to the system, so that the product can achieve the effect of reducing the idle travel of the brake system while meeting the driver's operating force requirements.

[0026] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable technicians familiar with the technical field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit and essence of the present invention should be included in the protection scope of the present invention. The technology, shape, and structure parts not described in detail in the present invention are all well-known technologies.

Claims

1. A brake transmission device for reducing the idle travel of a brake system, characterized in that: The invention comprises a housing (8), a large bushing (4) fixed in the housing (8), a large piston (14) arranged in the inner hole of the large bushing (4), a large leather cup (16) arranged between the large piston (14) and the large bushing (4), and the large leather cup (16) can move in the inner hole of the large bushing (4) along with the large piston (14); one end of a small piston (13) is fixed in the housing (8) through a push rod assembly (1), and the other end passes through the inner hole of the large piston (14); a small leather cup (17) is also arranged at the other end of the small piston (13), and can move in the inner hole of a small bushing (6) fixed in the housing (8) along with the other end of the small piston (13); a return spring (3) is arranged between the large piston (14) and the large bushing (4), and the large piston (14) and the push rod assembly (1) are connected to each other. 1), a large spring (12) is arranged between the large bushing (4) and the small bushing (6), and oil holes are arranged radially on the large bushing (4) and the small bushing (6); an output cavity is also arranged on the housing (8), and the output cavity is connected with the inner hole of the small bushing (6); the small piston (13) and the large piston (14) are clearance-matched, and a sealing ring (15) is arranged between the small piston (13) and the large piston (14); the initial elastic force of the large spring (12) is greater than the initial elastic force of the return spring (3) and is greater than the sum of the liquid pressure received by the large piston (14) when it moves to the extreme position, the elastic force of the return spring (3), the friction between the large leather cup (16) and the inner hole of the large bushing (4), the friction between the small leather cup (17) and the inner hole of the small bushing (6), the sealing ring (15) and the sealing friction of the small piston (13).

2. A brake transmission for reducing idle travel of a brake system as claimed in claim 1, characterized in that: The push rod assembly (1), the small piston (13), the large piston (14), the large bushing (4), the large leather cup (16), the small leather cup (17), and the small bushing (6) are coaxial.

3. A brake transmission for reducing idle travel of a brake system as claimed in claim 1, characterized in that: The push rod assembly (1) is threadedly connected to one end of the small piston (13).

4. A brake transmission for reducing idle travel of a brake system as claimed in claim 1, characterized in that: One end of the large bushing (4) is limited by a positioning sleeve (2) arranged in the housing (8), and the other end is limited by the housing (8).

5. A brake transmission for reducing idle travel of a brake system as claimed in claim 4, characterized in that: The positioning sleeve (2) is threadedly connected to the inner hole of the housing (8); an annular groove is provided on the outer circumferential surface of the middle part of the positioning sleeve (2); an oil through hole is provided on the annular groove; an oil filling port is provided on the housing (8); oil can enter the inner cavity of the housing (8) through the oil filling port and the oil through hole on the annular groove.

6. A brake transmission for reducing idle travel of a brake system as claimed in claim 1, characterized in that: Sealing rings are provided between the large bushing (4) and the housing (8), between the small bushing (6) and the housing (8), and between the push rod assembly (1) and the positioning sleeve (2).

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