Piston type damping front fork

Abstract

The utility model provides a piston type damping front fork, and belongs to the field of front forks. The problem how to prevent dust from entering the damping cylinder is solved. The piston type damping front fork comprises two front fork vertical pipes and two lower connecting plates, two connecting shoulders are arranged in an up-down structure, each front fork vertical pipe is composed of a piston cylinder and a piston column, a dustproof cylinder is arranged outside the tail end of each piston cylinder, the tail end of each dustproof cylinder is arranged in an inclined structure, and each piston column penetrates into the corresponding dustproof cylinder and is movably matched with the corresponding piston cylinder. A guide bush of a T-shaped structure is arranged at the middle section of the piston column and located in the dustproof barrel, the inner wall of the dustproof barrel extends inwards in the radial direction to be provided with a limiting ring part, and the guide bush comprises a fixed barrel fixedly connected with the piston column and a guide barrel with the guide function. A plurality of balls capable of rolling in the mode of being attached to the inner wall of the limiting ring part are evenly distributed on the side wall of the guide cylinder in the circumferential direction, and a plurality of O-shaped sealing rings for improving the sealing effect are embedded in the outer wall of the fixed cylinder. The sealing structure has the advantage of high sealing performance.

Description

Technical Field

[0001] This utility model belongs to the field of front forks, and relates to a front fork, and particularly to a piston-type shock-absorbing front fork. Background Technology

[0002] Bicycles, as one of the earliest modes of transportation, remain popular due to their affordability and versatility. However, the current front fork assembly features complex connections between its components, making assembly difficult. Furthermore, impurities often accumulate between the fork and the shock absorbers, leading to poor sliding between them under prolonged use and affecting shock absorption.

[0003] To address the aforementioned issues, various improvements have been made to the fork assembly. For example, Chinese patent literature discloses a high-strength shock-absorbing fork (application number CN202321475597.6), which achieves smooth shock absorption and stability by adding connecting components and guide bushings. At the same time, by using sealing gaskets and seals between the guide bushing, the shock-absorbing tube, and the guide post, the sealing strength is improved, preventing impurities from entering the shock-absorbing tube and accumulating.

[0004] The aforementioned high-strength shock-absorbing fork, equipped with a guide bushing, sealing gasket, and seal, although capable of reducing the entry of impurities into the shock absorber, still has the following drawbacks: the guide bushing is fixed to the end of the shock absorber, and there is still a gap between the guide bushing and the guide post. If there is no gap, the guide bushing and the guide post cannot move. If there is a gap, when the bicycle is driven in harsh environments such as dusty conditions, dust can easily enter the shock absorber through the gap, and dust accumulation can easily occur, affecting the stability of the bicycle's operation.

[0005] Therefore, there is an urgent need to develop a fork that greatly reduces the amount of dust entering the shock absorber. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned problems in the existing technology by providing a piston-type shock-absorbing fork to solve these issues.

[0007] The purpose of this utility model can be achieved through the following technical solution: a piston-type shock-absorbing front fork, including two fork stems and two lower connecting plates for easy fixed connection of the fork stems, the two connecting shoulders are arranged in an upper and lower structure, each fork stem is composed of a piston cylinder for shock absorption and a piston column that moves in conjunction with the piston cylinder, characterized in that a dustproof cylinder for preventing impurities from entering is provided outside the end of the piston cylinder, and the end of the dustproof cylinder is arranged in an inclined structure;

[0008] The piston rod is inserted into the dustproof cylinder and moves in conjunction with the piston cylinder.

[0009] A T-shaped guide bushing is provided in the middle section of the piston rod. The guide bushing is located inside the dustproof cylinder, and a limiting ring is provided on the inner wall of the dustproof cylinder to limit the movement of the guide bushing.

[0010] The guide bushing includes a fixed cylinder fixedly connected to the piston rod and a guide cylinder with a guiding function. Multiple balls that can roll against the inner wall of the limiting ring are evenly distributed around the side wall of the guide cylinder. Multiple O-rings that improve the sealing effect are embedded in the outer wall of the fixed cylinder.

[0011] The guide bushing can move axially synchronously with the piston rod, and the guide cylinder and the interior of the limiting ring can be guided by multiple ball structures.

[0012] In the aforementioned piston-type shock-absorbing fork, the dust cover and piston cylinder are integrally formed. The end of the dust cover has an inclination angle of 30-60° and is truncated into a frustum structure, forming a guide slope to direct airflow and impurities.

[0013] In the aforementioned piston-type shock-absorbing fork, the inner diameter of the fixed cylinder is larger than the inner diameter of the guide cylinder, forming a stepped structure. A 0.5-1mm gap is maintained between the outer side of the guide cylinder and the inner wall of the limiting ring to facilitate the rolling of the ball bearings.

[0014] In the aforementioned piston-type shock-absorbing fork, the outer wall of the fixed cylinder is provided with an annular groove for the O-ring seal to be installed.

[0015] In the aforementioned piston-type shock-absorbing fork, the guide bushing and the piston rod can be connected by an interference fit or by internal and external threaded connection.

[0016] Compared with existing technologies, this piston-type shock-absorbing fork has the following advantages:

[0017] 1. The dustproof cylinder is integrally molded and has a guide slope design, which significantly reduces the risk of impurities entering under harsh road conditions, extends the maintenance cycle, and can improve dustproof efficiency by about 40%. Its O-ring seal and ball guide combination achieves double sealing and is suitable for complex environments such as humid and dusty environments.

[0018] 2. The ball bearing guide structure design reduces friction loss, making the vibration damping action smoother and improving riding comfort. Actual measurements show a 60% reduction in friction resistance. The stepped guide bushing has a fixed cylinder inner diameter larger than the guide cylinder, which disperses stress concentration and improves the fatigue life of the components.

[0019] 3. The dust cover and piston cylinder are integrally molded, eliminating the risk of cracking at the connection and improving the overall rigidity. The guide bushing is interference-fitted / threaded to the piston column to prevent the parts from loosening and ensure long-term stability. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the piston-type shock-absorbing front fork.

[0021] Figure 2 This is a simplified cross-sectional diagram of a piston-type shock-absorbing front fork.

[0022] Figure 3 This is a three-dimensional structural diagram of the guide bushing of this piston-type shock-absorbing front fork.

[0023] In the diagram, 1. Front fork riser; 2. Lower connecting plate; 3. Piston cylinder; 4. Piston rod; 5. Dustproof sleeve; 6. Guide bushing; 7. Limiting ring; 8. Guide cylinder; 9. Fixed cylinder; 10. O-ring seal; 11. Ball bearing. Detailed Implementation

[0024] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0025] like Figure 1 , Figure 2 , Figure 3As shown, this piston-type shock-absorbing fork includes two fork stems 1 and two lower connecting plates 2 for easy fixed connection of the fork stems 1. The two connecting shoulders are arranged in an upper and lower structure. Each fork stem 1 is composed of a piston cylinder 3 for shock absorption and a piston rod 4 that moves with the piston cylinder 3. A dustproof sleeve 5 is provided outside the end of the piston cylinder 3 to prevent impurities from entering. The end of the dustproof sleeve 5 is inclined. The piston rod 4 passes into the dustproof sleeve 5 and moves with the piston cylinder 3. A T-shaped guide bushing 6 is provided in the middle section of the piston rod 4. The guide bushing 6 is located inside the dustproof sleeve 5, and a limiting ring 7 for limiting the movement of the guide bushing 6 is provided radially inward on the inner wall of the dustproof sleeve 5. The guide bushing 6 includes a fixed cylinder 9 fixedly connected to the piston rod 4 and a guide cylinder 8 with a guiding function. Multiple guide cylinders are evenly distributed on the side wall of the guide cylinder 8 to move with the piston rod 4. The inner wall of the limiting ring 7 is fitted with rolling balls 11, and the outer wall of the fixed cylinder 9 is fitted with multiple O-ring seals 10 to improve the sealing effect. The guide bushing 6 can move axially synchronously with the piston column 4. The guide cylinder 8 and the interior of the limiting ring 7 can be guided by multiple balls 11. The dustproof cylinder 5 and the piston cylinder 3 are integrally formed. The end of the dustproof cylinder 5 has an inclination angle of 30-60° and is set in a frustum structure to form a guide slope for guiding airflow and impurities. The inner diameter of the fixed cylinder 9 is larger than the inner diameter of the guide cylinder 8 to form a stepped structure. The outer side of the guide cylinder 8 and the inner wall of the limiting ring 7 maintain a 0.5-1mm gap fit to facilitate the rolling of the balls 11. The outer wall of the fixed cylinder 9 is provided with an annular groove for the O-ring seals 10 to be embedded and installed. The guide bushing 6 and the piston column 4 can be interference fit or internal and external threaded connection.

[0026] The dustproof cylinder 5, with its one-piece molding and guide slope design, significantly reduces the risk of impurities entering under harsh road conditions, extends maintenance intervals, and improves dustproof efficiency by approximately 40%. Its O-ring seal 10 and ball bearing 11 guide combination achieve double sealing, making it suitable for complex environments such as humid and dusty conditions. The ball bearing 11 guide structure design reduces friction loss, making vibration damping smoother and improving riding comfort; actual measurements show a 60% reduction in friction resistance. The stepped guide bushing 6, with its fixed cylinder 9 having a larger inner diameter than the guide cylinder 8, disperses stress concentration and improves component fatigue life. The dustproof cylinder 5 and piston cylinder 3 are integrally molded, eliminating the risk of cracking at the connection and improving overall rigidity. Its guide bushing 6 and piston column 4 are interference-fitted / threaded, preventing component loosening and ensuring long-term stability.

[0027] Working principle analysis:

[0028] This piston-type shock-absorbing fork achieves efficient shock absorption and durability through the following synergistic mechanism: The piston rod 4 moves axially within the piston cylinder 3, compressing the internal oil or gas medium and absorbing impact energy through fluid damping. The T-shaped structure of the guide bushing 6 (fixed cylinder 9 + guide cylinder 8) cooperates with the limiting ring 7 to ensure the straightness of the piston rod 4's movement trajectory and avoid uneven wear. The 30-60° inclined frustum design at the end of the dustproof cylinder 5 forms a guide slope, using the airflow and centrifugal force generated by the movement to guide impurities (such as mud, sand, and water) outwards rather than into the piston cylinder 3. The O-ring seal 10 of the fixed cylinder 9 blocks external contaminants; the clearance fit (0.5-1mm) between the guide cylinder 8 and the limiting ring 7, combined with the rolling of the ball bearings 11, forms a dynamic sealing barrier. The circumferentially distributed ball bearings 11 of the guide cylinder 8 roll into contact with the inner wall of the limiting ring 7, converting traditional sliding friction into rolling friction, reducing resistance (the coefficient of friction can be reduced by 50%-70%), and improving the shock absorption response speed.

[0029] 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.

[0030] Although this document uses a lot of technical terms, 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 invention; interpreting them as any kind of additional limitation would contradict the spirit of this invention.

Claims

1. A piston-type shock-absorbing front fork, comprising two fork stems (1) and two lower connecting plates (2) for easy fixed connection of the fork stems (1), the two connecting shoulders being arranged in an upper and lower structure, wherein each fork stem (1) is composed of a piston cylinder (3) for shock absorption and a piston rod (4) that movably cooperates with the piston cylinder (3), characterized in that, A dustproof cylinder (5) is provided outside the end of the piston cylinder (3) to prevent impurities from entering, and the end of the dustproof cylinder (5) is set with an inclined structure; The piston rod (4) is inserted into the dustproof cylinder (5) and moves in cooperation with the piston cylinder (3); A T-shaped guide bushing (6) is provided in the middle section of the piston rod (4). The guide bushing (6) is located inside the dustproof cylinder (5), and a limiting ring (7) for limiting the movement of the guide bushing (6) is provided on the inner wall of the dustproof cylinder (5) extending radially inward. The guide bushing (6) includes a fixed cylinder (9) fixedly connected to the piston rod (4) and a guide cylinder (8) with a guiding function. Multiple balls (11) that can roll against the inner wall of the limiting ring (7) are evenly distributed on the side wall of the guide cylinder (8). Multiple O-rings (10) that improve the sealing effect are embedded in the outer wall of the fixed cylinder (9). Among them, the guide bushing (6) can move axially synchronously with the piston rod (4), and the guide cylinder (8) and the limiting ring (7) can be guided to move through a structure of multiple balls (11).

2. The piston-type shock-absorbing front fork according to claim 1, characterized in that, The dustproof cylinder (5) and the piston cylinder (3) are integrally formed. The end of the dustproof cylinder (5) is inclined at an angle of 30-60° and is set in a frustum structure to form a guide slope for guiding airflow and impurities.

3. A piston-type shock-absorbing front fork according to claim 1, characterized in that, The inner diameter of the fixed cylinder (9) is larger than that of the guide cylinder (8) to form a stepped structure. The outer side of the guide cylinder (8) and the inner wall of the limiting ring (7) maintain a gap of 0.5-1mm to facilitate the rolling of the ball (11).

4. A piston-type shock-absorbing front fork according to claim 1, characterized in that, The outer wall of the fixed cylinder (9) is provided with an annular groove for the O-ring (10) to be inlaid and installed.

5. A piston-type shock-absorbing front fork according to claim 1, characterized in that, The guide bushing (6) and the piston rod (4) can be connected by an interference fit or by internal and external thread fit.

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