Upper brake pump with double oil seals and lateral pressure relief

Abstract

A brake upper pump with double oil seals and lateral pressure relief comprises a brake pump body which is provided with a piston cavity and an oil storage cavity which are communicated with each other. The brake handle is in running fit with the brake pump body, and the brake handle is in transmission fit with the piston mechanism; the oil pipe assembly is communicated with the piston cavity; the piston mechanism comprises a piston body, a first oil seal and a second oil seal, the second oil seal is located on the front side of the first oil seal, and the effective oil pushing area S1 of the second oil seal is smaller than that of the first oil seal; the reset spring acts on the piston body; the pressure relief valve mechanism is mounted in the pressure relief cavity of the brake pump body; the piston cavity is at least provided with a large-diameter cavity section, a small-diameter cavity section and a variable-diameter cavity section, and the pressure relief cavity is communicated with the variable-diameter cavity section through a pressure relief channel. A large-small-diameter double-piston oil seal structure is adopted, the effect that the front section has a relatively large oil seal area and the rear section has a relatively small oil seal area is achieved, and the overall brake performance can be more linear.

Description

Technical Field

[0001] This utility model relates to the technical field of hydraulic brakes, and in particular to a brake upper pump with double oil seals and lateral pressure relief. Background Technology

[0002] The master cylinder (upper cylinder) is a key component of a hydraulic braking system. It is typically mounted near the handlebars, close to the brake lever. Its main function is to convert the force applied by the rider through the brake lever into hydraulic pressure, thus initiating the braking process. The working principle is as follows: when the rider squeezes the brake lever, the force acts on the piston, which moves forward (towards the brake lines) within the cylinder. Piston movement and resistance characteristics: The resistance of the master cylinder piston's movement also affects the brake feel. Factors such as the friction between the piston and the cylinder, and the elasticity of the seals, determine the resistance of the piston's movement. If the piston's movement resistance is too high, the brake feel will be too stiff; if the resistance is too low, it may lead to unstable lever travel. Furthermore, the movement of the lower cylinder piston is equally important. When pressure is transmitted to the lower cylinder, the lower cylinder piston pushes the brake pads into contact with the brake disc. The frictional characteristics between the brake pads and the brake disc are also fed back to the brake lever. For example, when the brake pads wear down to a certain extent, the contact area and frictional characteristics with the brake disc change, which leads to a change in the brake feel, potentially making it softer or uneven.

[0003] Ideally, in a brake booster, the initial piston extension requires a relatively large oil seal area to deliver more brake fluid per unit distance traveled, allowing the brake pads to be quickly ejected and contact the brake disc, at which point the braking effect begins. In the later piston extension, the brake pads in the booster are nearly stationary (no displacement). According to Pascal's principle (pressure is constant throughout a closed system; at the same pressure, a smaller area generates less force), a relatively small oil seal area is needed to reduce the pressure on the piston (this pressure is proportional to the oil seal area). This allows the user to push the brake lever more easily, reducing the feeling of hitting a wall and making the initial and later stages of operation more linear. However, most existing brake boosters are single-piston (oil seal) structures, thus failing to achieve the effect of a relatively large oil seal area at the beginning and a relatively small oil seal area at the end.

[0004] In summary, this application improves upon the prior art. Summary of the Invention

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the present invention provides a brake upper pump with double oil seals and lateral pressure relief.

[0006] The technical solution of this utility model to solve its technical problem is: a brake upper pump with double oil seals and lateral pressure relief, comprising:

[0007] The brake pump body has a piston chamber and an oil reservoir, which are filled with brake fluid, and the oil reservoir is connected to the piston chamber through an oil return hole.

[0008] The brake handle is pivotally coupled to the brake pump body via a pivoting mechanism, and the brake handle is coupled to the piston mechanism via a rotary pushing mechanism, forming a transmission engagement.

[0009] The oil line assembly is connected to the brake pump body and communicates with the piston chamber;

[0010] The piston mechanism includes a piston body, a first oil seal and a second oil seal disposed on the piston body, wherein the second oil seal is located in front of the first oil seal, and the effective oil pushing area S2 of the second oil seal is smaller than the effective oil pushing area S1 of the first oil seal.

[0011] The return spring applies a backward elastic force to the piston body.

[0012] It also includes a pressure relief valve mechanism, and the brake pump body is provided with a pressure relief chamber, in which the pressure relief valve mechanism is installed;

[0013] The piston chamber has at least a large-diameter cavity section, a small-diameter cavity section, and a variable-diameter cavity section, wherein the large-diameter cavity section, the variable-diameter cavity section, and the small-diameter cavity section are distributed and connected from back to front;

[0014] The oil return hole is opened on the large-diameter cavity section so that the large-diameter cavity section is connected to the oil storage cavity.

[0015] The pressure relief chamber is connected to the variable diameter chamber section through a pressure relief channel;

[0016] The first oil seal is located in the large-diameter cavity section, and a sealing fit is formed when the first oil seal abuts against the inner wall of the large-diameter cavity section;

[0017] The second oil seal moves along with the piston body; when the second oil seal is located in the large-diameter cavity section, there is a gap between the second oil seal and the inner wall of the large-diameter cavity section to form a non-sealing fit; when the second oil seal is located in the small-diameter cavity section, the second oil seal abuts against the inner wall of the small-diameter cavity section to form a sealing fit.

[0018] A further description of this utility model is that when the second oil seal is not against the inner wall of the small-diameter cavity section and the first oil seal is located in front of the return oil hole, the user continues to squeeze the brake handle, and the first oil seal pushes the brake fluid toward the oil pipe assembly.

[0019] When the second oil seal abuts against the inner wall of the small-diameter cavity section, the user continues to squeeze the brake handle. The second oil seal pushes the brake fluid in front of the second oil seal toward the oil pipe assembly, and the first oil seal allows the brake fluid between the first oil seal and the second oil seal to flow into the pressure relief cavity through the pressure relief channel.

[0020] In a preferred embodiment of this utility model, the pressure relief valve mechanism includes a floating pressure relief valve core and a pressure relief spring;

[0021] The floating pressure relief valve core is movably disposed within the pressure relief chamber;

[0022] The pressure relief spring abuts against the inner wall of the floating pressure relief valve core and the pressure relief chamber. The pressure relief spring acts on the floating pressure relief valve core so that the floating pressure relief valve core has a tendency to move towards the pressure relief channel side.

[0023] Furthermore, the pressure relief valve mechanism also includes a sealing plug assembly, the pressure relief chamber has an installation opening, and the sealing plug assembly is detachably connected to the installation opening.

[0024] More specifically, the sealing plug assembly includes a mounting screw, a threaded plug, a spring seat threaded onto the mounting screw, and a plug sealing ring;

[0025] The threaded plug is fitted onto the mounting screw, and the threaded plug has a first external thread. The mounting opening has a first internal thread. The first external thread and the first internal thread form a threaded engagement so that the threaded plug is connected to the mounting opening.

[0026] There is a sealing gap between the threaded plug and the mounting opening, and the plug sealing ring is disposed in the sealing gap;

[0027] The mounting screw has a second external thread, and the spring seat has a second internal thread. The second external thread and the second internal thread form a threaded engagement so that the spring seat can be connected to the mounting screw.

[0028] The pressure relief spring abuts against the spring seat and the floating pressure relief valve core.

[0029] Preferably, the floating pressure relief valve core is provided with a plurality of valve core sealing rings, which abut against the inner wall of the pressure relief chamber to form a sealing fit between the floating pressure relief valve core and the inner wall of the pressure relief chamber.

[0030] In a preferred embodiment of this utility model, the piston mechanism further includes a piston cylinder liner, and the piston body extends at least partially into the piston cylinder liner and forms a transmission connection with the rotary thrust mechanism.

[0031] The piston cylinder liner has a protruding limiting part on its inner wall, which can abut against the rear end of the piston body to form a limiting stop.

[0032] Furthermore, the piston cylinder liner is provided with a cylinder liner sealing ring, which abuts against the inner wall of the piston cavity and forms a sealing fit.

[0033] The piston body is provided with a piston sealing ring, which abuts against the inner wall of the piston cylinder liner to form a sealing fit.

[0034] Preferably, the piston body has a first mounting groove and a second mounting groove, the first oil seal is embedded in the first mounting groove, and the second oil seal is embedded in the second mounting groove.

[0035] In some preferred embodiments of this utility model, the inner diameter of the second oil seal is larger than the inner diameter of the small diameter cavity section, and the inner diameter of the second oil seal is smaller than the inner diameter of the large diameter cavity section.

[0036] When the second oil seal is located in the latter part of the variable diameter cavity section, there is a gap between the second oil seal and the inner wall of the variable diameter cavity section to form a non-sealing fit; when the second oil seal is located in the former part of the variable diameter cavity section, the second oil seal abuts against the inner wall of the variable diameter cavity section to form a sealing fit.

[0037] The beneficial effects of this utility model are as follows:

[0038] First, it adopts a dual-piston oil seal structure with different diameters and implements a segmented working mode, achieving a relatively large oil seal area in the front section and a relatively small oil seal area in the rear section. When applied in hydraulic brakes, this allows for a larger initial oil push, enabling brake fluid to quickly fill tiny gaps and deformation spaces of elastic components, resulting in a more rapid braking effect. In the middle and rear sections, it can push the piston body forward with less force, ensuring that the piston body's pushing force in the middle and rear sections does not differ too much from that in the front and middle sections, resulting in a more linear overall motion performance.

[0039] Second, during the middle and later stages, the pressure between the first oil seal and the second oil seal can be relieved through the pressure relief valve mechanism, so that the oil pushing of the first oil seal has almost no impact on the second oil seal.

[0040] Third, based on the principle of lever arm operation, the point of application for the front and middle sections is at the first oil seal, while the point of application for the middle and rear sections is at the second oil seal. These are variable lever arm centers, meaning that the resistance and resistance arm change accordingly with the change of the point of application. In particular, the middle and rear sections have a larger power arm L1 (conventionally ending at the first oil seal, but in this invention ending at the second oil seal), while the resistance arm L2 is smaller. Therefore, when the user squeezes the brake lever, only a smaller force F1 is needed, resulting in less effort for the user to achieve the same braking effect.

[0041] Fourth, by changing the installation position of the sealing plug assembly (by changing the number of turns of the threaded engagement between the spring seat and the mounting screw) or by changing the size of the pressure relief spring, the initial state of the pressure relief valve mechanism (especially the floating pressure relief valve core) can be adjusted, for example, to achieve different preload performance, so as to achieve different pressure relief effects and meet the customized pressure relief needs of different users. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the structure of this utility model.

[0043] Figure 2 This is a schematic diagram of the piston mechanism.

[0044] Figure 3 This is a comparative diagram of the first and second oil seals.

[0045] Figure 4 This is a structural breakdown diagram of the pressure relief valve mechanism in this utility model.

[0046] Figure 5 This is a cross-sectional view of the piston mechanism when it is in the idle stroke section.

[0047] Figure 6 This is a cross-sectional view of the structure when the first oil seal is actually pushing oil.

[0048] Figure 7 This is a cross-sectional view of the structure when the second oil seal in Example 4 is actually pushing oil (the second oil seal abuts against the inner wall of the variable diameter cavity section).

[0049] Figure 8 This is a cross-sectional view of the structure when the second oil seal in Example 4 is actually pushing oil (the second oil seal abuts against the inner wall of the small-diameter cavity section).

[0050] Figure 9 This is a comparative diagram showing the changes in the installation position of the sealing plug assembly.

[0051] In the diagram: 1. Brake pump body; 11. Piston chamber; 111. Large diameter chamber section; 112. Small diameter chamber section; 113. Variable diameter chamber section; 12. Oil reservoir; 13. Oil return hole; 14. Pressure relief chamber; 141. Mounting opening; 142. Pressure relief passage; 15. Oil seal chamber; 2. Brake handle; 21. Pivoting mechanism; 22. Rotation mechanism; 3. Oil pipe assembly; 4. Piston mechanism; 41. Piston body; 411. First mounting groove; 412. Second mounting groove; 413. Piston sealing ring; 42. First oil seal; 43. Second oil seal; 5. Pressure relief valve mechanism; 51. Floating pressure relief valve core; 52. Pressure relief spring; 53. Sealing plug assembly; 531. Mounting screw; 532. Threaded plug; 533. Spring seat; 534. Plug sealing ring; 54. Valve core sealing ring; 6. Piston cylinder liner; 61. Limiting part; 62. Cylinder liner sealing ring; 7. Return spring. Detailed Implementation

[0052] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments are merely specific descriptions of the present invention, and their purpose is to enable those skilled in the art to better understand the technical solution of the present invention, and should not be regarded as limitations on the present invention.

[0053] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0054] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0055] Example 1

[0056] Reference Figures 1 to 8A brake pump with dual oil seals and lateral pressure relief includes: a brake pump body 1, which has a piston chamber 11 and an oil reservoir 12, the piston chamber 11 and the oil reservoir 12 being filled with brake fluid, and the oil reservoir 12 being connected to the piston chamber 11 through an oil return hole 13; a brake handle 2, which is rotatably engaged with the brake pump body 1 through a pivoting mechanism 21, and the brake handle 2 is abutted against and driven by a piston mechanism 4 through a thrust mechanism 22; and an oil pipe assembly 3, which is connected to the brake pump body 1 and is connected to the piston chamber 11, and the oil pipe assembly 3 can be extended to connect with the brake pump, so that a complete brake fluid circuit is formed between the brake pump and the brake pump. The piston mechanism 4 includes a piston body 41, a first oil seal 42 and a second oil seal 43 disposed on the piston body 41. The second oil seal 43 is located in front of the first oil seal 42, and the effective oil pushing area S2 of the second oil seal 43 is smaller than the effective oil pushing area S1 of the first oil seal 42. The two oil seals have different effective oil pushing areas, which can bring different oil pushing and braking effects. The return spring 7 applies a backward elastic force to the piston body 41 so that the piston body 41 always has a tendency to return to its original position. When the user releases the brake handle 2, the piston body 41 automatically returns to its original position under the action of the return spring 7 and the oil pressure.

[0057] It is particularly important to emphasize that a pressure relief valve mechanism 5 is also included. The brake pump body 1 also has a pressure relief chamber 14, and the pressure relief valve mechanism 5 is installed in the pressure relief chamber 14. Corresponding to the pressure relief valve mechanism 5, the piston chamber 11 has at least a large-diameter chamber section 111, a small-diameter chamber section 112, and a variable-diameter chamber section 113, wherein the large-diameter chamber section 111, the variable-diameter chamber section 113, and the small-diameter chamber section 112 are distributed sequentially from back to front and are interconnected. The oil return hole 13 is located on the large-diameter chamber section 111, so that the large-diameter chamber section 111 communicates with the oil reservoir 12. The pressure relief chamber 14 communicates with the variable-diameter chamber section 113 through a pressure relief channel 142. The first oil seal 42 is located in the large-diameter chamber section 111, and the first oil seal 42 forms a sealing fit when it abuts against the inner wall of the large-diameter chamber section 111. It should be particularly noted that the second oil seal 43 moves along with the piston body 41; when the second oil seal 43 is located in the large-diameter cavity section 111, there is a gap between the second oil seal 43 and the inner wall of the large-diameter cavity section 111 to form a non-sealing fit; when the second oil seal 43 is located in the small-diameter cavity section 112, the second oil seal 43 abuts against the inner wall of the small-diameter cavity section 112 to form a sealing fit.

[0058] Preferably, the pressure relief valve mechanism 5 includes a floating pressure relief valve core 51 and a pressure relief spring 52; wherein, the floating pressure relief valve core 51 is movably disposed in the pressure relief chamber 14; the pressure relief spring 52 abuts against the floating pressure relief valve core 51 and the inner wall of the pressure relief chamber 14, and the pressure relief spring 52 acts on the floating pressure relief valve core 51 so that the floating pressure relief valve core 51 has a tendency to move towards the side of the pressure relief channel 142.

[0059] Therefore, based on the change in the position of the second oil seal 43, the actual oil pushing operations of the first oil seal 42 and the second oil seal 43 differ and will switch. The working mechanism of the pressure relief valve is as follows:

[0060] When the first oil seal 42 moves in the space between the initial position and the return oil hole 13, the forward movement of the first oil seal 42 will push the brake fluid from the piston chamber 11 to the reservoir chamber 12 through the return oil hole 13 (that is, the brake fluid does not flow to the brake pump). Therefore, the brake does not work during this process. This section is also called the free travel section.

[0061] When the second oil seal 43 is not against the inner wall of the small diameter cavity section 112 and the first oil seal 42 is in front of the return oil hole 13, the user continues to squeeze the brake handle 2, and the first oil seal 42 pushes the brake fluid toward the oil pipe assembly 3. At this time, the pressure relief valve does not have the function of relieving pressure.

[0062] When the second oil seal 43 abuts against the inner wall of the small-diameter cavity section 112, a relatively sealed oil seal cavity 15 is formed between the first oil seal 42 and the second oil seal 43. The oil seal cavity 15 is isolated from the front side of the second oil seal 43. When the user continues to squeeze the brake handle 2, the second oil seal 43 pushes the brake fluid in front of the second oil seal 43 toward the oil pipe assembly 3, and the first oil seal 42 lets the brake fluid between the first oil seal 42 and the second oil seal 43 flow into the pressure relief cavity 14 through the pressure relief channel 142. The floating pressure relief valve core 51 is pushed back by pressure, and the pressure relief spring 52 contracts and stores force to achieve relative pressure balance, so that the pressure relief valve mechanism 5 plays an effective pressure relief role and prevents the pressure between the first oil seal 42 and the second oil seal 43 from being too large and affecting normal use.

[0063] In summary, the main advantages of this utility model are: it adopts a double-piston oil seal structure with different diameters and realizes a segmented working mode, achieving the effect of a relatively large oil seal area in the front section and a relatively small oil seal area in the rear section. Specifically, the first oil seal 42 in the front middle section performs the actual oil pushing work. Its characteristic is that the effective oil pushing area S1 of the first oil seal 42 is larger. When applied in hydraulic braking, it can make the initial oil pushing volume larger, and the brake fluid can quickly fill some small gaps and deformation space of elastic components, thus achieving a more rapid braking effect. The second oil seal 43 in the middle and rear sections performs the actual oil pushing work. Its characteristic is that the effective oil pushing area S2 of the second oil seal 43 is smaller. According to Pascal's principle (pressure is equal everywhere in a closed fluid, and under the same pressure, the smaller the area, the smaller the force generated), the pressure applied to the second oil seal 43 in the oil circuit is relatively small. Therefore, it can push the piston body 41 forward with less force, so that the pushing force of the piston body 41 in the middle and rear sections will not have too large a difference with the front and middle sections, that is, the overall motion performance will be more linear. Furthermore, during the middle and later stages, the pressure between the first oil seal 42 and the second oil seal 43 can be relieved through the pressure relief valve mechanism 5, so that the oil pushing of the first oil seal 42 has almost no impact on the second oil seal 43.

[0064] Another key advantage lies in the principle of lever arm operation (the formula is F1*L1=F2*L2; when you grip the brake handle 2 and apply force, the length of the lever arm affects the magnitude of the required force. Specifically, when the power arm (brake handle 2 lever arm) is longer, with a fixed resistance and resistance arm, the required force (the force you apply to the brake handle 2) is smaller—this is the principle of effort saving). Therefore, the point of application for the front-middle section of this application is at the first oil seal 42, and the point of application for the middle-rear section is at the second oil seal 43, which are variable lever arm centers. Correspondingly, when the point of application changes, the resistance and resistance arm also change. In particular, the middle-rear section has a larger power arm L1 (conventionally ending at the first oil seal 42, but in this invention ending at the second oil seal 43), while the resistance arm L2 is smaller. Thus, when the user squeezes the brake handle 2, only a smaller force F1 is needed, making it easier for the user to achieve the same braking effect with less effort.

[0065] It should be noted that the pressure relief chamber 14 in this disclosure is formed on the brake pump body 1 rather than on the piston mechanism 4. The brake pump body 1 has a larger structural size (the small size of the piston body 41 makes it difficult to process), so it is easier to process and form in manufacturing. The pressure relief chamber 14 is connected to the variable diameter chamber section 113 (piston chamber 11) through the lateral pressure relief channel 142. The pressure relief channel 142 is straight and has no inflection point, so the pressure relief effect is more direct, fast and unobstructed.

[0066] Preferably, the piston body 41 has a first mounting groove 411 and a second mounting groove 412. The first oil seal 42 is embedded in the first mounting groove 411, and the second oil seal 43 is embedded in the second mounting groove 412. The first mounting groove 411 and the second mounting groove 412 are provided so that the first oil seal 42 and the second oil seal 43 can be reliably assembled onto the piston body 41 and move together with the piston body 41.

[0067] Example 2

[0068] Based on Embodiment 1, a more preferred structural scheme for the pressure relief valve mechanism 5 is as follows: (Refer to...) Figures 3-8 The pressure relief valve mechanism 5 further includes a sealing plug assembly 53, and the pressure relief chamber 14 has an installation opening 141. The sealing plug assembly 53 is detachably connected to the installation opening 141. This detachable design facilitates the installation and debugging of the pressure relief valve mechanism 5; furthermore, it allows for easier maintenance and upkeep in case of malfunction, resulting in lower operating costs.

[0069] More specifically, the sealing plug assembly 53 includes a mounting screw 531, a threaded plug 532, a spring seat 533 threadedly connected to the mounting screw 531, and a plug sealing ring 534. The threaded plug 532 is fitted onto the mounting screw 531, and the threaded plug 532 has a first external thread. The mounting opening 141 has a first internal thread. The first external thread and the first internal thread form a threaded engagement, so that the threaded plug 532 is connected to the mounting opening 141. There is a sealing gap between the threaded plug 532 and the mounting opening 141. The plug sealing ring 534 is placed in the sealing gap to fill the space gap, provide good sealing performance, and prevent brake fluid leakage. The mounting screw 531 has a second external thread, and the spring seat 533 has a second internal thread. The second external thread and the second internal thread form a threaded engagement, so that the spring seat 533 is connected to the mounting screw 531. The pressure relief spring 52 abuts between the spring seat 533 and the floating pressure relief valve core 51, which effectively limits the pressure relief spring 52, so that the pressure relief spring 52 deforms according to the pre-designed trajectory when it extends and retracts, ensuring that it has a stable and reliable elastic working effect.

[0070] Preferably, the floating pressure relief valve core 51 is provided with a plurality of valve core sealing rings 54, which abut against the inner wall of the pressure relief chamber 14 to form a sealing fit between the floating pressure relief valve core 51 and the inner wall of the pressure relief chamber 14, preventing leakage, while providing a certain damping feel and pre-tightening force to solve the problem of loosening of the floating pressure relief valve core 51, especially to prevent the floating pressure relief valve core 51 from moving when the brake handle 2 is squeezed in the middle and front section.

[0071] Reference Figure 9 Another important function of this embodiment is that by changing the installation position of the sealing plug assembly 53 (by changing the number of turns of the threaded engagement between the spring seat 533 and the mounting screw 531) or by changing the size of the pressure relief spring 52, the initial state of the pressure relief valve mechanism 5 (especially the floating pressure relief valve core 51) can be adjusted to achieve different pressure relief effects and meet the customized pressure relief needs of different users.

[0072] Example 3

[0073] Reference Figures 4-8 In a preferred embodiment of this utility model, the piston mechanism 4 further includes a piston cylinder liner 6. The piston body 41 extends at least partially into the piston cylinder liner 6 and forms a transmission connection with the rotary thrust mechanism 22. A limiting part 61 protrudes from the inner wall of the piston cylinder liner 6, and the limiting part 61 abuts against the rear end of the piston body 41 to form a limiting stop. The piston cylinder liner 6 is mainly provided to support, limit and protect, and guide the movement of the piston body 41. On the other hand, the rotary thrust mechanism 22 can extend partially into the piston cylinder liner 6 and abut against the first piston to achieve a transmission connection between the rotary thrust mechanism 22 and the piston body 41 (first piston).

[0074] Furthermore, the piston cylinder liner 6 is provided with a cylinder liner sealing ring 62, which abuts against the inner wall of the piston cavity 11 to form a sealing fit; the piston body 41 is provided with a piston sealing ring 413, which abuts against the inner wall of the piston cylinder liner 6 to form a sealing fit. By setting multiple sealing rings, the gaps between related components are filled to ensure a good sealing fit, prevent oil leakage, and stabilize the internal pressure.

[0075] Example 4

[0076] In this embodiment, refer to Figure 7 The inner diameter of the second oil seal 43 is larger than the inner diameter of the small diameter cavity section 112, and the inner diameter of the second oil seal 43 is smaller than the inner diameter of the large diameter cavity section 111. When the second oil seal 43 is located in the rear part of the variable diameter cavity section 113, there is a gap between the second oil seal 43 and the inner wall of the variable diameter cavity section 113 to form a non-sealing fit. When the second oil seal 43 is located in the front part of the variable diameter cavity section 113, the second oil seal 43 abuts against the inner wall of the variable diameter cavity section 113 to form a sealing fit.

[0077] To ensure proper sealing, the first oil seal 42 and the second oil seal 43 are larger than their corresponding sections within the piston chamber 11. For example, the diameter of the large-diameter chamber section 111 is 11.5 mm, and the diameter of the first oil seal 42 is 12 mm; the diameter of the small-diameter chamber section 112 is 9 mm, and the diameter of the second oil seal 43 is 9.7 mm; the diameter of the variable-diameter chamber section 113 is between 9 mm and 11.5 mm. Therefore, when the second oil seal 43 moves to the latter half of the variable-diameter chamber section 113, it abuts against the inner wall of the variable-diameter chamber section 113 and forms a sealing fit, meaning the second oil seal 43 begins its actual oil-pushing function earlier.

[0078] In Example 1, the lever arm's working mechanism changed once, specifically when the actual oil-pushing oil seal switched from the first oil seal 42 to the second oil seal 43. In this example, the lever arm's working mechanism changes multiple times. The first change is when the actual oil-pushing oil seal switches from the first oil seal 42 to the second oil seal 43, and the second oil seal 43 is still in the variable diameter cavity section 113. Then, as it moves from the variable diameter cavity section 113 to the small diameter cavity section 112, it needs to continuously change. After fully entering the small diameter cavity section 112, it stabilizes at another working mechanism. The difference between this example and Example 3 is that, according to Pascal's principle (F2 = P*S), the force S exerted by the second oil seal 43 in the variable diameter cavity section 113 and the small diameter cavity section 112 (due to the continuously changing diameter of the second oil seal 43, gradually decreasing from 9.7 mm to 9 mm) constantly changes, thus causing the force F2 to continuously change. According to the formula for lever arm, F1*L1=F2*L2, when F2 changes, while the working conditions of L1 and L2 remain unchanged, F1 will also change continuously. That is, in the middle and later stage (when the second oil seal 43 performs the actual oil pushing work), the force of the user squeezing the brake handle 2 under the same working conditions, F1 gradually decreases.

[0079] It is worth noting that the other technical solutions of this utility model are all existing technologies, and therefore will not be described in detail.

[0080] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the concept of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A brake booster pump with dual oil seals and lateral pressure relief, comprising: The brake pump body (1) has a piston chamber (11) and an oil reservoir (12), the piston chamber (11) and the oil reservoir (12) are filled with brake fluid, and the oil reservoir (12) is connected to the piston chamber (11) through an oil return hole (13). The brake handle (2) is rotated with the brake pump body (1) through the pivot mechanism (21), and the brake handle (2) is abutted against the piston mechanism (4) through the rotary push mechanism (22) and forms a transmission connection. Oil pipe assembly (3), which is connected to brake pump body (1) and communicates with piston chamber (11); The piston mechanism (4) includes a piston body (41), a first oil seal (42) and a second oil seal (43) disposed on the piston body (41), wherein the second oil seal (43) is located in front of the first oil seal (42), and the effective oil pushing area S2 of the second oil seal (43) is smaller than the effective oil pushing area S1 of the first oil seal (42). The return spring (7) applies a backward elastic force to the piston body (41); Its features are, It also includes a pressure relief valve mechanism (5), and the brake pump body (1) is provided with a pressure relief chamber (14), and the pressure relief valve mechanism (5) is installed in the pressure relief chamber (14); The piston chamber (11) has at least a large-diameter chamber section (111), a small-diameter chamber section (112), and a variable-diameter chamber section (113), wherein the large-diameter chamber section (111), the variable-diameter chamber section (113), and the small-diameter chamber section (112) are distributed and connected from back to front; The oil return hole (13) is opened on the large-diameter cavity section (111) so that the large-diameter cavity section (111) is connected to the oil storage cavity (12); The pressure relief chamber (14) is connected to the variable diameter chamber section (113) through the pressure relief channel (142); The first oil seal (42) is located in the large-diameter cavity section (111), and a sealing fit is formed when the first oil seal (42) abuts against the inner wall of the large-diameter cavity section (111); The second oil seal (43) moves along with the piston body (41); when the second oil seal (43) is located in the large diameter cavity section (111), there is a gap between the second oil seal (43) and the inner wall of the large diameter cavity section (111) to form a non-sealing fit; when the second oil seal (43) is located in the small diameter cavity section (112), the second oil seal (43) abuts against the inner wall of the small diameter cavity section (112) to form a sealing fit.

2. The brake upper pump with double oil seals and lateral pressure relief according to claim 1, characterized in that: When the second oil seal (43) does not abut against the inner wall of the small diameter cavity section (112) and the first oil seal (42) is located in front of the return oil hole (13), the user continues to squeeze the brake handle (2), and the first oil seal (42) pushes the brake fluid toward the oil pipe assembly (3); When the second oil seal (43) abuts against the inner wall of the small diameter cavity section (112), the user continues to squeeze the brake handle (2). The second oil seal (43) pushes the brake fluid in front of the second oil seal (43) toward the oil pipe assembly (3), and the first oil seal (42) lets the brake fluid between the first oil seal (42) and the second oil seal (43) flow into the pressure relief chamber (14) through the pressure relief channel (142).

3. The brake upper pump with double oil seals and lateral pressure relief according to claim 1, characterized in that: The pressure relief valve mechanism (5) includes a floating pressure relief valve core (51) and a pressure relief spring (52); The floating pressure relief valve core (51) is movably disposed within the pressure relief chamber (14); The pressure relief spring (52) abuts against the inner wall of the floating pressure relief valve core (51) and the pressure relief chamber (14). The pressure relief spring (52) acts on the floating pressure relief valve core (51) so that the floating pressure relief valve core (51) has a tendency to move towards the pressure relief channel (142).

4. The brake upper pump with double oil seals and lateral pressure relief according to claim 3, characterized in that: The pressure relief valve mechanism (5) further includes a sealing plug assembly (53), the pressure relief chamber (14) has an installation opening (141), and the sealing plug assembly (53) is detachably connected to the installation opening (141).

5. The brake upper pump with double oil seals and lateral pressure relief according to claim 4, characterized in that: The sealing plug assembly (53) includes a mounting screw (531), a threaded plug (532), a spring seat (533) threaded onto the mounting screw (531), and a plug sealing ring (534); The threaded plug (532) is sleeved on the mounting screw (531), and the threaded plug (532) has a first external thread, and the mounting opening (141) has a first internal thread. The first external thread and the first internal thread form a threaded engagement so that the threaded plug (532) is connected to the mounting opening (141). There is a sealing gap between the threaded plug (532) and the mounting opening (141), and the plug sealing ring (534) is disposed in the sealing gap; The mounting screw (531) has a second external thread, and the spring seat (533) has a second internal thread. The second external thread and the second internal thread form a threaded engagement so that the spring seat (533) is connected to the mounting screw (531). The pressure relief spring (52) abuts between the spring seat (533) and the floating pressure relief valve core (51).

6. The brake upper pump with double oil seals and lateral pressure relief according to claim 3, characterized in that: The floating pressure relief valve core (51) is provided with a plurality of valve core sealing rings (54), and the valve core sealing rings (54) abut against the inner wall of the pressure relief chamber (14) so ​​that a sealing fit is formed between the floating pressure relief valve core (51) and the inner wall of the pressure relief chamber (14).

7. The brake upper pump with double oil seals and lateral pressure relief according to claim 1, characterized in that: The piston mechanism (4) further includes a piston cylinder liner (6), and the piston body (41) extends at least partially into the piston cylinder liner (6) and forms a transmission connection with the rotary thrust mechanism (22); The piston cylinder liner (6) has a protruding limiting part (61) on its inner wall. The limiting part (61) can abut against the rear end of the piston body (41) and form a limiting stop.

8. The brake upper pump with double oil seals and lateral pressure relief according to claim 7, characterized in that: The piston cylinder liner (6) is provided with a cylinder liner sealing ring (62), which abuts against the inner wall of the piston cavity (11) and forms a sealing fit; The piston body (41) is provided with a piston sealing ring (413), which abuts against the inner wall of the piston cylinder liner (6) and forms a sealing fit.

9. The brake upper pump with double oil seals and lateral pressure relief according to claim 1, characterized in that: The piston body (41) is provided with a first mounting groove (411) and a second mounting groove (412). The first oil seal (42) is embedded in the first mounting groove (411), and the second oil seal (43) is embedded in the second mounting groove (412).

10. The brake upper pump with double oil seals and lateral pressure relief according to any one of claims 1-9, characterized in that: The inner diameter of the second oil seal (43) is larger than the inner diameter of the small diameter cavity section (112), and the inner diameter of the second oil seal (43) is smaller than the inner diameter of the large diameter cavity section (111). When the second oil seal (43) is located in the rear part of the variable diameter cavity section (113), there is a gap between the second oil seal (43) and the inner wall of the variable diameter cavity section (113) to form a non-sealing fit; when the second oil seal (43) is located in the front part of the variable diameter cavity section (113), the second oil seal (43) abuts against the inner wall of the variable diameter cavity section (113) and forms a sealing fit.

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