Piston bore and piston bore assembly of a motorcycle brake caliper

Abstract

The utility model provides a kind of piston hole and piston hole assembly of motorcycle brake caliper, belong to brake technical field.It solves the technical problem such as not tight, viscous and so on of existing technology sealing.This piston hole of motorcycle brake caliper, including the piston hole being set in caliper body, the dust seal ring groove being set on the inner wall of piston hole, the main seal ring groove being set on the inner wall of piston hole and located in the inboard of dust seal ring groove, the piston hole is communicated with oil hole, the inner wall of main seal ring groove is inclined wall, the inner diameter of inclined wall gradually increases from the inner end to the outer end of piston hole and forms.This utility model has the advantages such as good dynamic and static sealing, strong durability, not susceptible to environmental influences etc.

Description

Technical Field

[0001] This utility model belongs to the field of brake technology, and relates to caliper equipment, and in particular to a piston hole and piston hole assembly for a motorcycle brake caliper. Background Technology

[0002] The caliper is a core component of the braking system, responsible for receiving hydraulic pressure from the brake control mechanism, pushing the piston to squeeze the brake pads against the brake disc, thus slowing down or stopping the wheel. The caliper piston bore is used to mate with the piston, and the inner wall of the piston bore has sealing grooves. During operation, the sealing rings often stick or get stuck. Furthermore, the frequent movement of the piston within the piston bore can easily cause leaks in the sealing groove structure, thus affecting braking performance. To address these issues, researchers have conducted extensive research and proposed various solutions.

[0003] For example, a Chinese patent document discloses a machining process for a caliper piston hole [Application No.: CN202110897532.X], the steps of which include: first rough machining a rectangular sealing groove in the piston hole, the diameter of the first rough-machined rectangular groove being smaller than the final diameter of the rectangular sealing groove; second rough machining the rectangular sealing groove in the piston hole, the diameter of the second rough-machined rectangular groove being smaller than the diameter of the first rectangular groove; machining an oil accumulation groove on the side wall of the rectangular groove; and finish machining the rectangular sealing groove according to the final diameter of the rectangular sealing groove. This can prevent the problem of oil leakage that easily occurs after the caliper has been used for a period of time.

[0004] While the above solution is effective in preventing oil leakage in a static state, leakage is still likely to occur when the piston is in dynamic operation, and it does not solve the problems of slow return and sticking of the sealing ring. Summary of the Invention

[0005] The purpose of this utility model is to address the above-mentioned problems by providing a piston bore for a motorcycle brake caliper with better sealing performance. Another objective of this invention is to address the aforementioned problems by providing a piston hole assembly for a motorcycle brake caliper.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The piston hole of the motorcycle brake caliper includes a piston hole disposed in the caliper body. A dust sealing ring groove is formed on the inner wall of the piston hole. A main sealing ring groove located inside the dust sealing ring groove is also formed on the inner wall of the piston hole. The piston hole is connected to the oil hole. The inner wall of the main sealing ring groove is an inclined wall. The inner diameter of the inclined wall gradually increases from the inner end to the outer end of the piston hole.

[0007] By designing the inner wall of the main sealing ring groove as an inclined wall structure, a significant self-pressurization effect can be generated when the system is pressurized, allowing the sealing force to automatically increase with the working pressure, ensuring good sealing performance under both static and dynamic conditions. Simultaneously, when the system is depressurized, the inclined wall structure facilitates the rapid return of the sealing ring and reduces sticking and jamming. In the piston bore of the aforementioned motorcycle brake caliper, the inner diameter of the main sealing ring groove is larger than that of the dust seal ring groove. This larger inner diameter of the main sealing ring groove provides space for the sealing ring within the main sealing ring groove to prevent jamming and excessive wear. Simultaneously, this design closely matches the sloping wall structure of the main sealing ring groove, ensuring that the sloping walls reduce sticking and jamming. Furthermore, this differentiated design for the functional requirements of different sealing rings further optimizes the caliper's sealing performance and stability.

[0008] In the piston hole of the aforementioned motorcycle brake caliper, an angle α is formed between the inclined wall and the central axis of the piston hole, and the angle α is 1-9°. If the angle is too small, its effect on reducing friction will be very weak, and jamming is likely to occur. At the same time, if the angle is too large, the positioning stability of the sealing ring in the groove will be poor, making it prone to tilting or displacement, and it is not conducive to the sealing ring forming an effective sealing force, leading to the risk of seal failure.

[0009] In the piston bore of the aforementioned motorcycle brake caliper, the included angle α is 5°. This angle value represents a balance between effectively reducing friction, ensuring smooth return, and maintaining good sealing performance and structural stability.

[0010] In the piston bore of the aforementioned motorcycle brake caliper, a first annular chamfer and a second annular chamfer are respectively provided between the two sides of the main sealing ring groove and the inner wall of the piston bore. Providing the first and second annular chamfers on both sides of the main sealing ring groove eliminates sharp groove corners, preventing the main sealing ring from being scratched during operation or installation, thereby contributing to improved durability and sealing reliability. Furthermore, this design facilitates piston return and reduces the risk of damage during piston installation.

[0011] In the piston hole of the aforementioned motorcycle brake caliper, a third annular chamfer is provided between the lower end of the inclined wall and the side wall of the main sealing ring groove. The connection between the lower end of the inclined wall and the side wall of the main sealing ring groove is the area where stress concentrates when the main sealing ring deforms. The structure of the third annular chamfer provides a smooth transition surface at this location, which prevents the main sealing ring from being excessively stretched or compressed locally, reduces the risk of fatigue cracking, and improves the service life and reliability of the main sealing ring.

[0012] In the piston hole of the aforementioned motorcycle brake caliper, an annular bottom groove is provided at the inner end of the piston hole, and an annular arc-shaped chamfer is provided between the annular bottom groove and the inner wall of the piston hole. Providing an annular arc-shaped chamfer between the annular bottom groove and the inner wall of the piston hole reduces stress concentration and prevents the deformation gap from increasing under high pressure, thus preventing the sealing material from being forced into the gap and squeezed out. In the piston bore of the aforementioned motorcycle brake caliper, an oil hole is provided on the inner end or inner sidewall of the piston bore. The opening at the bottom of the inner end or on the sidewall allows the oil to enter the piston bottom chamber via the shortest path, or for the oil to directly impact the piston bottom, resulting in high force transmission efficiency and improved braking response speed.

[0013] The piston bore assembly of this motorcycle brake caliper includes the piston bore of the motorcycle brake caliper as described above. A dust-sealing annular seal is provided within the dust-sealing seal groove, and a main seal is provided within the main seal groove. The outer diameter of the main seal is larger than the maximum inner diameter of the dust-sealing annular seal, and the inner diameter of the main seal is larger than the inner diameter of the piston bore. The width of the main seal is smaller than the width of the main seal groove. The outer diameter of the main seal is larger than the maximum inner diameter of the dust-sealing seal, ensuring that the main seal can form a tight contact with the sidewall of the main seal groove, especially the critical inclined wall, and generate sufficient compression, providing an effective hydraulic seal and preventing brake fluid leakage. The inner diameter of the main seal is larger than the inner diameter of the piston bore, ensuring that the inner lip of the main seal will not have continuous and excessive frictional contact with the inner wall of the piston bore.

[0014] In the piston bore assembly of the aforementioned motorcycle brake caliper, the inner wall of the dust-sealing annular seal ring has an annular groove. The gap (width difference) between the annular groove and the seal ring itself forms a receiving space located at the root of the sealing lip. This allows some dirt to be temporarily retained in the groove. This prevents dirt from accumulating again, causing jamming or accelerated wear.

[0015] Compared with existing technologies, the advantages of the piston bore and piston bore assembly of this motorcycle brake caliper are: 1. The inclined groove bottom structure provides excellent static and dynamic sealing effects. 2. The chamfered structure provides guidance for installation and movement, and enhances durability. 3. The multi-stage groove design reduces wear on the main sealing ring and provides strong adaptability to the working environment. 5. An anti-extrusion structure prevents leakage of sealing material. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the piston hole structure provided by this utility model.

[0017] Figure 2 This is a schematic diagram of the dust-sealing annular sealing ring structure provided by this utility model.

[0018] Figure 3This is a schematic diagram of the main sealing ring structure provided by this utility model.

[0019] Figure 4 This is a schematic diagram of the inclined wall angle structure provided by this utility model.

[0020] Figure 5 This is a schematic diagram of the oil hole structure provided by this utility model.

[0021] In the figure, there are caliper body 1, oil hole 11, piston hole 2, dust seal groove 21, main seal groove 22, first annular chamfer 221, second annular chamfer 222, inclined wall 23, third annular chamfer 231, annular bottom groove 24, annular arc chamfer 241, dust seal annular seal 3, annular groove 31, and main seal 4. Detailed Implementation

[0022] like Figures 1 to 5 As shown, the piston hole of this motorcycle brake caliper includes a piston hole 2 disposed in the caliper body 1. A dust sealing ring groove 21 is provided on the inner wall of the piston hole 2. A main sealing ring groove 22 located inside the dust sealing ring groove 21 is also provided on the inner wall of the piston hole 2. The piston hole 2 is connected to the oil hole 11. The inner wall of the main sealing ring groove 22 is an inclined wall 23. The inner diameter of the inclined wall 23 gradually increases from the inner end to the outer end of the piston hole 2.

[0023] In this embodiment, an inclined wall 23 with a gradually increasing inner diameter from the inner end to the outer end of the piston hole 2 is provided on the inner wall of the main sealing ring groove 22. The inclined wall 23 can decompose the fluid pressure into an axial component force, which causes the sealing surface to be further compressed when the system pressure increases, thereby realizing a pressure self-boosting effect. Furthermore, the sealing force can automatically increase with the working pressure, effectively improving the sealing performance under static and dynamic conditions and reducing leakage. In addition, during system depressurization or piston retraction, the inclined wall 23 can guide the main sealing ring 4 to smoothly return to its original position in the groove, which is beneficial for rapid reset and reduces the occurrence of sticking and jamming. The deformation and recovery of the main sealing ring 4 also helps to drive the piston back to its original position, increasing the piston return amount and solving the problem of dragging brakes.

[0024] Meanwhile, the inclined wall 23 structure also helps to make the contact stress distribution more uniform, thereby reducing local stress concentration, reducing the risk of tearing, and improving the durability and reliability of the seal.

[0025] More specifically, the inner diameter of the main sealing ring groove 22 is larger than the inner diameter of the dust sealing ring groove 21.

[0026] In this embodiment, a suitable groove size design can achieve a suitable compression ratio, which ensures sufficient contact pressure for sealing while avoiding excessive friction and over-extrusion, thus extending the service life.

[0027] like Figure 4 As shown, the inclined wall 23 and the central axis of the piston hole 2 form an angle α, which is 1-9°. Specifically, the angle α is 5°.

[0028] like Figure 1 As shown, a first annular chamfer 221 and a second annular chamfer 222 are respectively provided between the two sides of the main sealing ring groove 22 and the inner wall of the piston hole 2.

[0029] In this embodiment, an annular chamfer structure is provided between the two sides of the dust sealing ring groove 21 and the inner wall of the piston hole 2, and between the piston hole opening and the inner wall of the piston hole 2.

[0030] More specifically, a third annular chamfer 231 is provided between the lower end of the inclined wall 23 and the side wall of the main sealing ring groove 22.

[0031] More specifically, the piston bore 2 has an annular bottom groove 24 at its inner end, and an annular arc-shaped chamfer 241 between the annular bottom groove 24 and the inner wall of the piston bore 2. An oil hole 11 is provided on the inner end of the piston bore 2.

[0032] like Figure 5 As shown, the oil hole 11 passes through the caliper body 1 and communicates with the bottom of the piston hole 2. The connection port with the piston hole 2 is located in the area of ​​the annular bottom groove 24.

[0033] In this embodiment, the spherical oil hole 11 is conducive to air venting and also helps to remove burrs and avoid scratching the bottom of the piston.

[0034] like Figures 1 to 3 As shown, the piston hole assembly of this motorcycle brake caliper includes the piston hole 2 of the motorcycle brake caliper as described above, a dust sealing ring groove 21 is provided with a dust sealing ring 3, a main sealing ring groove 22 is provided with a main sealing ring 4, the outer diameter of the main sealing ring 4 is larger than the maximum inner diameter of the dust sealing ring 3, the inner diameter of the main sealing ring 4 is larger than the inner diameter of the piston hole 2, and the width of the main sealing ring 4 is smaller than the width of the main sealing ring groove 22.

[0035] In this embodiment, the multi-stage sealing ring structure, including the main sealing ring 4 and the dust-sealing annular sealing ring 3, effectively traps dust and impurities, preventing contaminants from entering the sealing system. This structure reduces the risk of wear and scratches from foreign objects on the main sealing ring 4, thereby improving reliability and service life.

[0036] More specifically, the outer wall axis of the main sealing ring 4 is parallel to the central axis of the main sealing ring 4, and the inner wall of the dust sealing ring 3 is provided with an annular groove 31.

[0037] The working principle of this embodiment is that, in the standby state without braking force, there is no hydraulic pressure in the piston bore 2. The main sealing ring 4 slightly contracts due to its own elasticity, and its inner diameter is slightly larger than the inner diameter of the piston bore 2, thereby avoiding friction with the piston surface. The dust-sealing annular sealing ring 3 prevents external dust and other contaminants from entering the interior of the piston bore 2.

[0038] During braking, hydraulic pressure propels brake fluid through oil hole 11 into piston hole 2, causing the piston to move outward and compress the brake pads. Simultaneously, this forces the main sealing ring 4 to deform, creating a high-pressure seal. The width of the main sealing ring 4 is smaller than the width of the main sealing ring groove 22, allowing for slight axial movement to accommodate pressure changes.

[0039] During the release process, after the hydraulic pressure is released, the piston needs to retract and reset. The elasticity of the main sealing ring 4 causes it to contract inward, and the tapered shape of the inclined wall 23 assists the sealing ring to return to its original position more smoothly, reducing dragging.

[0040] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0041] Although this document frequently uses terms such as caliper body, oil hole, piston hole, dust seal groove, main seal groove, first annular chamfer, second annular chamfer, beveled wall, third annular chamfer, annular bottom groove, annular arc chamfer, dust seal annular ring, annular groove, and main seal, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

Claims

1. A piston hole for a motorcycle brake caliper, comprising a piston hole (2) disposed within a caliper body (1), wherein a dust sealing ring groove (21) is formed on the inner wall of the piston hole (2), and a main sealing ring groove (22) located inside the dust sealing ring groove (21) is also formed on the inner wall of the piston hole (2), wherein the piston hole (2) communicates with an oil hole (11), characterized in that, The inner wall of the main sealing ring groove (22) is an inclined wall (23), and the inner diameter of the inclined wall (23) gradually increases from the inner end to the outer end of the piston hole (2).

2. The piston hole of the motorcycle brake caliper according to claim 1, characterized in that, The inner diameter of the main sealing ring groove (22) is larger than the inner diameter of the dust sealing ring groove (21).

3. The piston hole of the motorcycle brake caliper according to claim 1, characterized in that, An angle α is formed between the inclined wall (23) and the central axis of the piston hole (2), and the angle α is 1-9°.

4. The piston hole of the motorcycle brake caliper according to claim 3, characterized in that, The included angle α is 5°.

5. The piston bore of the motorcycle brake caliper according to any one of claims 1-4, characterized in that, The main sealing ring groove (22) is provided with a first annular chamfer (221) and a second annular chamfer (222) on both sides and the inner wall of the piston hole (2).

6. The piston bore of the motorcycle brake caliper according to claim 5, characterized in that, A third annular chamfer (231) is provided between the lower end of the inclined wall (23) and the side wall of the main sealing ring groove (22).

7. The piston bore of the motorcycle brake caliper according to any one of claims 1-4, characterized in that, The piston hole (2) is provided with an annular bottom groove (24) at its inner end, and an annular arc chamfer (241) is provided between the annular bottom groove (24) and the inner wall of the piston hole (2).

8. The piston bore of the motorcycle brake caliper according to any one of claims 1-4, characterized in that, The piston hole (2) is provided with the oil hole (11) on the inner end or the inner end sidewall.

9. A piston bore assembly for a motorcycle brake caliper, characterized in that, The piston hole (2) of the motorcycle brake caliper as described in any one of claims 1-8 is provided in the dust sealing ring groove (21) and the main sealing ring groove (22) is provided in the main sealing ring (4). The outer diameter of the main sealing ring (4) is greater than the maximum inner diameter of the dust sealing ring (3), the inner diameter of the main sealing ring (4) is greater than the inner diameter of the piston hole (2), and the width of the main sealing ring (4) is less than the width of the main sealing ring groove (22).

10. The piston bore assembly of the motorcycle brake caliper according to claim 9, characterized in that, The inner wall of the dust-sealing annular sealing ring (3) is provided with an annular groove (31).

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