A hydraulic brake master cylinder for agricultural machinery

Abstract

The present invention provides a hydraulic brake master cylinder for agricultural machinery, which includes a cylinder block. A piston is arranged in the cylinder block, and a brake chamber and an oil inlet chamber are formed between the piston and the cylinder block. The brake chamber is located on the front side of the oil inlet chamber. An oil outlet hole communicating with the brake chamber is provided at the front end of the cylinder block. An oil cup hole is provided at the rear end of the cylinder block. An oil inlet hole communicating with the oil inlet chamber is provided at the bottom of the oil cup hole, and an oil overflow hole communicating with the inner cavity of the cylinder block is provided at the bottom of the oil cup hole. A check valve one that only allows the oil in the oil cup hole to enter the oil inlet chamber is arranged in the oil inlet hole. A rubber cup is arranged on the piston between the brake chamber and the oil inlet chamber. An oil passage communicating the brake chamber and the oil inlet chamber is also arranged in the cylinder block. The end of the oil passage communicating with the brake chamber is an oil outlet, and the end of the oil passage communicating with the oil inlet chamber is an oil inlet. In the initial state, the oil outlet is located on the front side of the rubber cup, the oil overflow hole is located on the front side of the rubber cup, the rubber cup is located between the oil overflow hole and the oil inlet hole, and the oil outlet is located in front of the oil overflow hole.

Description

Technical Field

[0001] The present invention relates to the technical field of brake assemblies, and more particularly to a hydraulic brake master cylinder for agricultural machinery. Background Art

[0002] The brake master cylinder belongs to a one-way acting piston type hydraulic cylinder, and its function is to convert the mechanical energy input by the pedal mechanism into hydraulic energy, which is mainly divided into two types: single chamber and double chamber.

[0003] During use, the driver steps on the foot pedal to force the piston to move forward through the push rod. During this process, the piston drives the rubber cup to cross the overflow hole. At this time, the hydraulic pipeline is closed, and the foot force is transmitted downward through the brake fluid. When the braking is released, the return spring pushes the piston to quickly return to its original position.

[0004] During the entire braking process, what is desired is a state of large flow rate and high oil pressure to obtain a relatively high braking efficiency. However, these two states are a relative state during the forward movement of the piston. The existing methods can only make a choice between the two to obtain a balanced state, enabling both to be taken into account, but neither is the optimal state. Such a setting results in a relatively low flow rate and oil pressure in the early stage of braking due to the low pressure in the brake chamber, and the braking efficiency is not high enough. Summary of the Invention

[0005] In view of the problems pointed out in the background art, the present invention proposes a hydraulic brake master cylinder for agricultural machinery that can improve the braking efficiency in the early stage of braking.

[0006] The technical solution of the present invention is implemented as follows:

[0007] A hydraulic brake master cylinder for agricultural machinery includes a cylinder block. A piston is provided inside the cylinder block. A brake chamber and an oil inlet chamber are formed between the piston and the cylinder block, and the brake chamber is located in front of the oil inlet chamber.

[0008] A spring is provided inside the brake chamber. The spring is coaxially arranged with the piston. The front end of the spring abuts against the front end of the cylinder block, and the rear end of the spring abuts against the front end of the piston.

[0009] An oil outlet hole communicating with the brake chamber is provided at the front end of the cylinder block.

[0010] An oil cup hole is provided at the rear end of the cylinder block. An oil inlet hole communicating with the oil inlet chamber is provided at the bottom of the oil cup hole, and an overflow hole communicating with the inner cavity of the cylinder block is provided at the bottom of the oil cup hole.

[0011] A check valve one that only allows the oil in the oil cup hole to enter the oil inlet chamber is provided in the oil inlet hole.

[0012] A rubber cup is provided on the piston between the brake chamber and the oil inlet chamber.

[0013] An oil passage is also provided in the cylinder block to connect the brake chamber and the oil inlet chamber. The end of the oil passage connecting the brake chamber is the oil outlet, and the end of the oil passage connecting the oil inlet chamber is the oil inlet.

[0014] In the initial state, the oil outlet is located on the front side of the rubber cup, the oil overflow hole is located on the front side of the rubber cup, the rubber cup is located between the oil overflow hole and the oil inlet hole, and the oil outlet is located in front of the oil overflow hole.

[0015] The present invention is further configured such that a check valve II is provided in the oil passage, which only allows the oil in the oil inlet chamber to enter the brake chamber.

[0016] The present invention is further configured such that when the rubber cup moves forward to block the oil inlet, the oil overflow hole communicates with the oil inlet chamber, and the oil in the oil inlet chamber is introduced into the oil cup hole.

[0017] The present invention is further configured such that a sealing piece protruding forward is provided at the front end of the rubber cup corresponding to the position of the oil inlet. In the initial state, the sealing piece is in a state of blocking the oil inlet.

[0018] The present invention is further configured such that the rubber cup is fixedly connected to the piston in the circumferential direction.

[0019] Adopting the above technical solutions, the beneficial effects of the present invention are as follows:

[0020] For the hydraulic brake master cylinder provided by the present invention for agricultural machinery, when the piston moves forward, the oil inlet chamber becomes smaller. Due to the setting of the check valve I, the brake fluid in the oil inlet chamber cannot be discharged from the oil cup. At this time, the hydraulic pressure in the oil inlet chamber increases, and the brake fluid in the oil inlet chamber will enter the brake chamber through the oil passage, thereby increasing the pressure in the brake chamber, and thus improving the braking efficiency in the early stage of braking.

[0021] During the process of the piston continuing to move forward, when the rubber cup passes over the oil overflow hole and moves to block the oil inlet, the oil overflow hole communicates with the oil inlet chamber, and the oil in the oil inlet chamber is introduced into the oil cup hole, and the pressure in the oil inlet chamber is released, so that the remaining brake fluid enters the oil cup hole.

[0022] After the brake is released, the piston moves backward under the action of the spring, and the check valve I opens to start oil inlet. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a schematic structural diagram of Embodiment 1 of the present invention;

[0025] Figure 2 It is a schematic structural diagram of Embodiment 2 of the present invention;

[0026] Figure 3 It is a schematic structural diagram of the rubber cup of Embodiment 2 of the present invention. Detailed implementation manners

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] The following is a reference Figures 1-3 for the description of the present invention:

[0029] Embodiment 1: As Figure 1 shown, a hydraulic brake master cylinder for agricultural machinery includes a cylinder block 1. A piston 2 is arranged in the cylinder block 1. A brake chamber 4 and an oil inlet chamber 3 are formed between the piston 2 and the cylinder block 1. The brake chamber 4 is located on the front side of the oil inlet chamber 3.

[0030] A spring 5 is arranged in the brake chamber 4. The spring 5 is coaxially arranged with the piston 2. The front end of the spring 5 abuts against the front end of the cylinder block 1, and the rear end of the spring 5 abuts against the front end of the piston 2.

[0031] An oil outlet hole 6 communicating with the brake chamber 4 is arranged at the front end of the cylinder block 1.

[0032] An oil cup hole 7 is arranged at the rear end of the cylinder block 1. An oil inlet hole 8 communicating with the oil inlet chamber 3 is arranged at the bottom of the oil cup hole 7. An oil overflow hole 9 communicating with the inner cavity of the cylinder block 1 is arranged at the bottom of the oil cup hole 7.

[0033] A check valve 10 that only allows the oil in the oil cup hole 7 to enter the oil inlet chamber 3 is arranged in the oil inlet hole 8.

[0034] A rubber cup 11 is arranged on the piston 2 between the brake chamber 4 and the oil inlet chamber 3.

[0035] An oil passage 12 communicating the brake chamber 4 and the oil inlet chamber 3 is further arranged in the cylinder block 1. The end of the oil passage 12 communicating with the brake chamber 4 is an oil outlet 121, and the end of the oil passage 12 communicating with the oil inlet chamber 3 is an oil inlet 122.

[0036] In the initial state, the oil outlet 121 is located on the front side of the rubber cup 11, the oil overflow hole 9 is located on the front side of the rubber cup 11, the rubber cup 11 is located between the oil overflow hole 9 and the oil inlet hole 8, and the oil outlet 121 is located in front of the oil overflow hole 9.

[0037] Wherein, a check valve II 13 that only allows the oil in the oil inlet cavity 3 to enter the brake cavity 4 is provided in the oil passage 12.

[0038] Wherein, when the rubber cup 11 moves forward to block the oil inlet 122, the oil overflow hole 9 communicates with the oil inlet cavity 3, and the oil in the oil inlet cavity 3 is introduced into the oil cup hole 7.

[0039] Working principle: In the early stage of braking, the oil passage 12 can introduce the brake fluid in the oil inlet cavity 3 into the brake cavity 4, so that a large hydraulic pressure can be generated in the brake cavity 4 in the early stage of braking, thereby improving the braking efficiency in the early stage of braking.

[0040] Embodiment 2: As Figure 2 and 3 shown, a hydraulic brake master cylinder for agricultural machinery includes a cylinder block 1. A piston 2 is arranged in the cylinder block 1. A brake cavity 4 and an oil inlet cavity 3 are formed between the piston 2 and the cylinder block 1. The brake cavity 4 is located on the front side of the oil inlet cavity 3. A spring 5 is arranged in the brake cavity 4. The spring 5 is coaxially arranged with the piston 2. The front end of the spring 5 abuts against the front end of the cylinder block 1, and the rear end of the spring 5 abuts against the front end of the piston 2. An oil outlet hole 6 communicating with the brake cavity 4 is arranged at the front end of the cylinder block 1. An oil cup hole 7 is arranged at the rear end of the cylinder block 1. An oil inlet hole 8 communicating with the oil inlet cavity 3 is arranged at the bottom of the oil cup hole 7. An oil overflow hole 9 communicating with the inner cavity of the cylinder block 1 is arranged at the bottom of the oil cup hole 7. A check valve I 10 that only allows the oil in the oil cup hole 7 to enter the oil inlet cavity 3 is arranged in the oil inlet hole 8. A rubber cup 11 is arranged on the piston 2 between the brake cavity 4 and the oil inlet cavity 3. An oil passage 12 communicating the brake cavity 4 and the oil inlet cavity 3 is further arranged in the cylinder block 1. The end of the oil passage 12 communicating with the brake cavity 4 is an oil outlet 121, and the end of the oil passage 12 communicating with the oil inlet cavity 3 is an oil inlet 122. In the initial state, the oil outlet 121 is located on the front side of the rubber cup 11, the oil overflow hole 9 is located on the front side of the rubber cup 11, the rubber cup 11 is located between the oil overflow hole 9 and the oil inlet hole 8, and the oil outlet 121 is located in front of the oil overflow hole 9.

[0041] A sealing piece 14 protruding forward is arranged at the front end of the rubber cup 11 corresponding to the position of the oil inlet 122. In the initial state, the sealing piece 14 is in a state of blocking the oil inlet 122. The rubber cup 11 and the piston 2 are fixedly connected in the circumferential direction.

[0042] Compared with the solution of Embodiment 1, a check valve is not provided in the oil passage 12 in Embodiment 2. Instead, the oil inlet 122 is blocked by the sealing piece 14. The sealing piece 14 will closely adhere to the inner wall of the brake cavity 4 under the action of the pressure in the brake cavity 4 to block and close the oil inlet 122. When the pressure in the oil inlet cavity 3 is greater than that in the brake cavity 4, the brake fluid in the oil inlet cavity 3 can push up the sealing piece 14 through the oil passage 12.

[0043] In the initial state, the sealing piece 14 blocks the oil inlet 122, and the hydraulic pressure in the braking chamber 4 and the oil inlet chamber 3 is in a balanced state.

[0044] Adopting the above technical solution, the beneficial effects of the present invention are as follows:

[0045] For the hydraulic brake master cylinder used on agricultural machinery provided by the present invention, when the piston 2 moves forward, the oil inlet chamber 3 becomes smaller. Due to the setting of the check valve 10, the brake fluid in the oil inlet chamber 3 cannot be discharged from the oil cup. At this time, the hydraulic pressure in the oil inlet chamber 3 increases, and the brake fluid in the oil inlet chamber 3 will enter the braking chamber 4 through the oil passage 12, thereby increasing the pressure in the braking chamber 4, so as to improve the braking efficiency in the early stage of braking.

[0046] During the process of the piston 2 continuing to move forward, when the rubber cup 11 crosses the overflow hole and moves to block the oil inlet 122, the overflow hole 9 is communicated with the oil inlet chamber 3, and the oil in the oil inlet chamber 3 is introduced into the oil cup hole 7, and the pressure in the oil inlet chamber 3 is released, so that the remaining brake fluid enters the oil cup hole 7.

[0047] After the braking is released, the piston 2 moves backward under the action of the spring 5, and the check valve 10 opens to start oil inlet.

[0048] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydraulic brake master cylinder for agricultural machinery, characterized in that: It includes a cylinder block, a piston is arranged inside the cylinder block, a braking chamber and an oil inlet chamber are formed between the piston and the cylinder block, and the braking chamber is located on the front side of the oil inlet chamber; A spring is arranged inside the braking chamber, the spring is coaxially arranged with the piston, the front end of the spring abuts against the front end of the cylinder block, and the rear end of the spring abuts against the front end of the piston; An oil outlet hole communicating with the braking chamber is arranged at the front end of the cylinder block; An oil cup hole is arranged at the rear end of the cylinder block, an oil inlet hole communicating with the oil inlet chamber is arranged at the bottom of the oil cup hole, and an oil overflow hole communicating with the inner cavity of the cylinder block is arranged at the bottom of the oil cup hole; A check valve one that only allows the oil in the oil cup hole to enter the oil inlet chamber is arranged inside the oil inlet hole; A rubber cup is arranged on the piston between the braking chamber and the oil inlet chamber; An oil passage communicating the braking chamber and the oil inlet chamber is also arranged inside the cylinder block, the end of the oil passage communicating with the braking chamber is the oil outlet, and the end of the oil passage communicating with the oil inlet chamber is the oil inlet; In the initial state, the oil outlet is located on the front side of the rubber cup, the oil overflow hole is located on the front side of the rubber cup, the rubber cup is located between the oil overflow hole and the oil inlet hole, and the oil outlet is located in front of the oil overflow hole; A sealing piece protruding forward is arranged at the front end of the rubber cup corresponding to the position of the oil inlet. In the initial state, the sealing piece is in a state of blocking the oil inlet; When the rubber cup moves forward to block the oil inlet, the oil overflow hole communicates with the oil inlet chamber, and the oil in the oil inlet chamber is introduced into the oil cup hole.

2. The hydraulic brake master cylinder for agricultural machinery according to claim 1, characterized in that: The rubber cup and the piston are fixedly connected in the circumferential direction.

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