Brake top hat structure

Abstract

The utility model belongs to the technical field of transmission component design, and relates to a brake top hat structure. Including the axle and the top hat body of setting in the blind hole of axle, the top hat body from the end of contact with the top pin includes the taper section, the big cylinder section and the small cylinder section in proper order, a plurality of through -holes are provided on the taper section and the big cylinder section, the big cylinder section's outer diameter is installed with the blind hole cooperation, the small cylinder section is equipped with the spring, and the length of big cylinder section is greater than the maximum displacement distance of the piston corresponding thereto. The utility model discloses a brake top hat structure, and the inner diameter of blind hole bottom is designed as being greater than the outer diameter of spring but less than the outer diameter of top hat big cylinder section, forms double restriction: the outer diameter of top hat big cylinder section and the clearance cooperation of blind hole, when the spring is compressed, the bottom of big cylinder section and the bottom of blind hole contact, form radial support, avoid that the spring produces the inclination because of assembly deviation or uneven force.

Description

Technical Field

[0001] This utility model belongs to the field of transmission component design technology, and relates to a brake cap structure. Background Technology

[0002] With the trend of integrated development of transmissions and the requirements of cost control, most transmission main gearboxes currently adopt pneumatic operation and sliding sleeve shifting schemes. When switching between different gears, the clutch needs to be engaged to interrupt the engine input, reduce the shaft speed, and push the sliding sleeve to engage the designated gear. Compared with the synchronizer shifting scheme used in traditional transmissions, the former is not as good as the latter in terms of shifting time and smoothness. It is necessary to use the brake to accelerate the shifting process to make up for the deficiencies. At the same time, a buffer device is used to reduce the impact and wear of the brake. The top cap is an important part of the buffer device, and its structural rationality is related to the shifting performance and user experience.

[0003] The top cap is often assembled with a spring. During gear shifting, gas pushes the piston into contact with the friction plate, reducing the shaft speed. Simultaneously, the top pin on the piston surface pushes the top cap to compress the spring, preventing rigid collision between the piston and the friction plate. After shifting, the gas supply stops, the spring returns to its original position, pushing the top cap and piston back to their initial positions. In actual assembly, the top cap and the shaft blind hole have a clearance fit. Under normal operating conditions, the top cap and the shaft do not move at the same speed, and the spring does not rotate. However, due to insufficient lubrication inside the top cap and the spring, uneven spring compression, and excessive air pressure in the top cap, the spring, the inner wall of the top cap, and the top pin suffer severe wear and generate noise, seriously affecting user operation. For example, the top cap structure used in the Chinese utility model patent "An Intermediate Shaft Brake" with authorization announcement number CN211039467U will produce the above problems in actual operation. Utility Model Content

[0004] The purpose of this invention is to solve the technical problem of the existing brake cap structure having defects in lubrication and air pressure balance, and to provide a brake cap structure.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, this utility model discloses a brake cap structure, including a shaft and a cap body disposed in a blind hole in the shaft. The cap body, from the end in contact with the top pin, sequentially includes a tapered section, a large cylindrical section, and a small cylindrical section. A plurality of through holes are provided through the tapered section and the large cylindrical section. The outer diameter of the large cylindrical section is fitted with the blind hole. A spring is sleeved on the small cylindrical section.

[0006] Further improvements are made in the following aspects: The outer diameter of the large cylindrical section is clearance-fitted with the blind hole.

[0007] One end of the spring is in contact with the end face of the large cylindrical section, and the other end is in contact with the bottom surface of the blind hole.

[0008] The inner diameter of the blind hole decreases sequentially from the front end to the bottom.

[0009] The length of the large cylindrical section is greater than the maximum displacement distance of its corresponding piston.

[0010] The cone angle of the cone segment is 15°-30°.

[0011] A composite sealing structure is provided at the blind hole entrance.

[0012] The composite sealing structure includes an O-ring embedded between the shaft and the top cap body and a nano-hydrophobic coating applied to the contact surface.

[0013] The tapered section of the top cap body is provided with a carburized and quenched layer, with a surface hardness of HRC50-55, and the contact part with the top pin is provided with a diamond-like coating.

[0014] The inner diameter of the spring is 0.5-1 mm larger than the outer diameter of the small cylindrical section.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This utility model discloses a brake cap structure. The inner diameter of the bottom of the blind hole is designed to be larger than the outer diameter of the spring but smaller than the outer diameter of the large cylindrical section of the cap, forming a double constraint: after the spring is fitted into the small cylindrical section, its outer diameter is restricted by the bottom of the blind hole, but the inner diameter of the bottom is still larger than the outer diameter of the spring, ensuring that the spring can be freely compressed axially; the outer diameter of the large cylindrical section of the cap is clearance-fitted with the blind hole, and when the spring is compressed, the bottom of the large cylindrical section contacts the bottom of the blind hole, forming radial support, preventing the spring from tilting due to assembly deviation or uneven force. The axial length of the large cylindrical section exceeds the maximum displacement of the piston, ensuring that the cap remains in fit with the blind hole throughout the piston's movement, preventing it from coming off; the clearance fit design (inner diameter of the blind hole inlet > outer diameter of the cap) reduces the frictional resistance between the cap and the blind hole, while the matching accuracy between the outer diameter of the large cylindrical section and the inner diameter of the blind hole ensures the straightness of the axial movement, avoiding swaying. The eccentric through-holes in the tapered and large cylindrical sections form a fluid channel: when the brake is working, internal pressure changes can be quickly balanced through the through-holes, preventing the top cap from sticking due to pressure differences; the through-hole structure allows lubricating media (such as brake fluid) to penetrate to the contact surface, forming a lubricating film, reducing the friction coefficient between the top cap and the top pin, and between the top cap and the blind hole, while also reducing the accumulation of wear particles and extending service life. Uniform spring compression: the outer diameter of the small cylindrical section is less than the inner diameter of the spring, ensuring the spring is only subjected to axial force and avoiding bending; pressure balance: the through-hole connects the inner and outer spaces of the blind hole, eliminating the impact of hydraulic fluctuations on the top cap during braking; anti-disengagement: the length of the large cylindrical section is greater than the piston displacement, so even if the piston moves to its limit position, the top cap still retains part of the large cylindrical section within the blind hole, maintaining the fit. This design, through the combination of segmented optimization of geometric dimensions and fluid dynamics, solves the problems of spring tilting, top cap disengagement, and insufficient lubrication in traditional top cap structures, improving the reliability and durability of the braking system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a front view of the top cap in a brake top cap structure according to an embodiment of the present utility model; Figure 2 This is a cross-sectional view of the top cap in a brake top cap structure according to an embodiment of the present utility model; Figure 3 This is a side view of the top cap in a brake top cap structure according to an embodiment of the present utility model; Figure 4 This is a schematic diagram of the working function of a brake top cap structure in an embodiment of this utility model.

[0018] Wherein: 1-piston; 2-top pin; 3-top cap; 4-spring; 5-shaft; 6-friction plate. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of the embodiments of this utility model, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, they are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the utility model. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0024] In the description of the embodiments of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 according to the specific circumstances.

[0025] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 , Figure 2 , Figure 3 and Figure 4 This utility model discloses a brake cap structure, including a shaft 5 and a cap body disposed in a blind hole in the shaft 5. The cap body, starting from the end in contact with the top pin 2, sequentially includes a tapered section, a large cylindrical section, and a small cylindrical section; the tapered angle of the tapered section is 15°-30°. Several through holes are provided through the tapered section and the large cylindrical section; the outer diameter of the large cylindrical section is clearance-fitted with the blind hole; a spring 4 is sleeved on the small cylindrical section, one end of the spring 4 contacting the end face of the large cylindrical section and the other end contacting the bottom surface of the blind hole. The inner diameter of the blind hole decreases sequentially from the front end to the bottom. The length of the large cylindrical section is greater than the maximum displacement distance of its corresponding piston 1. A composite sealing structure is provided at the entrance of the blind hole. The composite sealing structure includes an O-ring embedded between the shaft 5 and the cap body and a nano-hydrophobic coating applied to the contact surface. The tapered section of the top cap body undergoes carburizing and quenching treatment, achieving a surface hardness of HRC50-55, and a diamond-like coating is applied to the contact area with the top pin 2. The inner diameter of the spring 4 is 0.5-1 mm larger than the outer diameter of the small cylindrical section.

[0026] This utility model discloses a brake cap structure. The inner diameter of the bottom of the blind hole is designed to be larger than the outer diameter of the spring but smaller than the outer diameter of the large cylindrical section of the cap, forming a double constraint: after the spring is fitted into the small cylindrical section, its outer diameter is restricted by the bottom of the blind hole, but the inner diameter of the bottom is still larger than the outer diameter of the spring, ensuring that the spring can be freely compressed axially; the outer diameter of the large cylindrical section of the cap is clearance-fitted with the blind hole, and when the spring is compressed, the bottom of the large cylindrical section contacts the bottom of the blind hole, forming radial support, preventing the spring from tilting due to assembly deviation or uneven force. The axial length of the large cylindrical section exceeds the maximum displacement of the piston, ensuring that the cap remains in fit with the blind hole throughout the piston's movement, preventing it from coming off; the clearance fit design (inner diameter of the blind hole inlet > outer diameter of the cap) reduces the frictional resistance between the cap and the blind hole, while the matching accuracy between the outer diameter of the large cylindrical section and the inner diameter of the blind hole ensures the straightness of the axial movement, avoiding swaying. The eccentric through-holes in the tapered and large cylindrical sections form a fluid channel: when the brake is working, internal pressure changes can be quickly balanced through the through-holes, preventing the top cap from sticking due to pressure differences; the through-hole structure allows lubricating media (such as brake fluid) to penetrate to the contact surface, forming a lubricating film, reducing the friction coefficient between the top cap and the top pin, and between the top cap and the blind hole, while also reducing the accumulation of wear particles and extending service life. Uniform spring compression: the outer diameter of the small cylindrical section is less than the inner diameter of the spring, ensuring the spring is only subjected to axial force and avoiding bending; pressure balance: the through-hole connects the inner and outer spaces of the blind hole, eliminating the impact of hydraulic fluctuations on the top cap during braking; anti-disengagement: the length of the large cylindrical section is greater than the piston displacement, so even if the piston moves to its limit position, the top cap still retains part of the large cylindrical section within the blind hole, maintaining the fit. This design, through the combination of segmented optimization of geometric dimensions and fluid dynamics, solves the problems of spring tilting, top cap disengagement, and insufficient lubrication in traditional top cap structures, improving the reliability and durability of the braking system.

[0027] Example 1 A novel brake cap structure includes a piston 1, a top pin 2, a top cap 3, a spring 4, a shaft 5, and a friction plate 6. The piston 1 is provided with a top pin 2, which is interference-fitted with the piston 1; the shaft 5 is provided with a friction plate 6, which is fully constrained; a top cap 3 and a spring 4 are sequentially provided in the blind hole along the axial direction at the front end of the shaft 5. One end of the top cap 3 is in contact with the top pin 2, and the other end is in contact with the end face of the spring 4. The maximum outer diameter of the top cap 3 is clearance-fitted with the inner wall of the blind hole of the shaft 5, and the other end face of the spring 4 is in contact with the bottom end face of the blind hole of the shaft 5.

[0028] Furthermore, the inner diameter of the blind hole in shaft 5 is not a constant size. The inner diameter at the front end of the blind hole is large, which is clearance-fitted with the outer diameter of the top cap 3. The inner diameter at the bottom of the blind hole is reduced, which facilitates the constraint of the radial movement area of ​​the spring 4, guides the spring 4 to be initially installed along the axial direction, prevents the spring 4 from tilting, and avoids unreasonable friction with the blind hole. Furthermore, the length of the maximum outer diameter of the top cap 3 should at least exceed the maximum displacement distance of the piston 1 to ensure that the spring 4 can always move axially when compression or rebound occurs, preventing the top cap 3 from coming out of the blind hole. At the same time, the spring 4 is in a compressed state when it is initially assembled, that is, the top pin 2 and the top cap 3 are pressed together. Furthermore, the other end of the tapered structure of the top cap 3 is a slender cylindrical structure. The outer diameter of this structure is smaller than the inner diameter of the spring 4, meaning that the spring 4 can be fitted into this section when installed. When the spring is compressed and rebounds, it plays a role in restraining radial displacement. At the same time, the distance between the end face and the bottom of the blind hole should be greater than the maximum displacement distance of the piston 1. Furthermore, a through hole is provided at the contact end between the top cap 3 and the top pin 2. The through hole can balance the internal pressure when the top cap 3 is axially displaced. That is, the clamping force of the top cap 3 and the top pin 2 is provided by the spring 4. At the same time, the through hole can pass oil to provide lubrication for the top cap 3 and the spring 4 inside the blind hole, reducing wear and background noise caused by dry friction.

[0029] The brake cap structure designed in this utility model has an inner diameter of blind hole inlet that is larger than the outer diameter of cap, and an inner diameter of blind hole bottom that is larger than the outer diameter of spring but smaller than the outer diameter of cap. The bottom plays a role in constraining the radial displacement of spring, thus avoiding the spring from tilting during initial assembly. The brake cap structure designed in this utility model is divided into three sections according to the cross-sectional shape: a conical section, a large cylindrical section, and a small cylindrical section. The axial length of the large cylindrical section is greater than the maximum axial displacement of the piston, and it is in clearance fit with the inner diameter of the blind hole, which facilitates the axial displacement of the cap and prevents the cap from coming off. The brake cap structure designed in this utility model has a small cylindrical section with an outer diameter smaller than the inner diameter of the spring. During installation, the spring is fitted into this section to ensure that the spring is compressed axially and elongated evenly when it rebounds. The tapered section and the large cylindrical section are provided with eccentric through holes to balance the internal pressure of the blind hole and to provide lubrication for the spring and the cap.

[0030] The working principle of this utility model is as follows: This invention replaces the existing conical and hollow cylindrical sections of the top cap 3 with conical, large cylindrical, and small cylindrical sections. The large and small cylindrical sections of the top cap 3 guide the axial displacement of the top cap and constrain the radial displacement of the spring, respectively. This provides a better radial effect on the spring 4 than a conventional top cap 3, significantly reducing the risk of spring compression and tilting, and also allowing for a corresponding reduction in spring length. Furthermore, eccentric through holes are provided in the conical and large cylindrical sections. These through holes balance the internal pressure during axial displacement of the top cap 3 and allow for oil passage, providing lubrication for the top cap 3 and spring 4 inside the blind hole, reducing background noise caused by wear, i.e., dry friction.

[0031] like Figure 4As shown, the inner diameter of the blind hole in shaft 5 is not constant. The inner diameter at the front end of the blind hole is large, which is clearance-fitted with the outer diameter of the top cap 3. The inner diameter at the bottom of the blind hole is reduced, which facilitates the constraint of the radial movement area of ​​the spring 4, guides the spring 4 to be initially installed along the axial direction, and prevents the spring 4 from tilting. At the same time, the eccentric through hole provided in the top cap 3 can balance the internal pressure when the top cap 3 is axially displaced. That is, the clamping force of the top cap 3 and the top pin 2 is provided by the spring 4.

[0032] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A brake cap structure, characterized in that, Includes a shaft (5) and a top cap body disposed in a blind hole in the shaft (5). The top cap body includes a tapered section, a large cylindrical section and a small cylindrical section in sequence from the end that contacts the top pin (2). Several through holes are provided through the tapered section and the large cylindrical section. The outer diameter of the large cylindrical section is fitted with the blind hole. A spring (4) is sleeved on the small cylindrical section.

2. The brake cap structure according to claim 1, characterized in that, The outer diameter of the large cylindrical section is clearance-fitted with the blind hole.

3. The brake cap structure according to claim 1, characterized in that, One end of the spring (4) is in contact with the end face of the large cylindrical section, and the other end is in contact with the bottom surface of the blind hole.

4. The brake cap structure according to claim 1, characterized in that, The inner diameter of the blind hole decreases sequentially from the front end to the bottom.

5. The brake cap structure according to claim 1, characterized in that, The length of the large cylindrical section is greater than the maximum displacement distance of its corresponding piston (1).

6. The brake cap structure according to claim 1, characterized in that, The cone angle of the cone segment is 15°-30°.

7. The brake cap structure according to claim 1, characterized in that, A composite sealing structure is provided at the blind hole entrance.

8. The brake cap structure according to claim 7, characterized in that, The composite sealing structure includes an O-ring embedded between the shaft (5) and the top cap body, and a nano-hydrophobic coating applied to the contact surface.

9. The brake cap structure according to claim 1, characterized in that, The conical section of the top cap body is provided with a carburized and quenched layer with a surface hardness of HRC50-55, and the contact part with the top pin (2) is provided with a diamond-like coating.

10. The brake cap structure according to claim 1, characterized in that, The inner diameter of the spring (4) is 0.5-1 mm larger than the outer diameter of the small cylindrical section.

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