An adjustable seat tube mechanism

Abstract

The utility model belongs to bicycle seat tube technical field especially adjustable seat tube mechanism, including bicycle frame, one end of bicycle frame is installed with seat tube through screw, the inside of seat tube is provided with adjusting device, adjusting device includes seat, the bottom of seat is installed with support rod, the bottom of support rod is provided with the joint groove, the bottom of support rod is located in the inside of seat tube. This adjustable seat tube mechanism, the device adjustment is convenient and accurate, the user passes through the rotation ergonomics adjusting runner, through the thread drive of drive screw and rectangular tube, drives drive piston high -efficient extrusion hydraulic oil, the cooperation of rectangular chute and rectangular pipe ensures the linear motion of piston, oil pressure steady push from the driven piston and rectangular telescopic rod lift, and the quantifiable characteristic of thread lead is combined, realizes the fine control of seat height.

Description

Technical Field

[0001] This utility model relates to the field of bicycle seat post technology, and in particular to an adjustable seat post mechanism. Background Technology

[0002] Existing adjustable seatpost mechanisms suffer from several drawbacks in practical applications. Firstly, there is a mismatch between adjustment precision and ease of use. Most mechanisms employ bolt locking or simple sleeve structures, requiring tools to loosen the bolts during adjustment. This reliance on manual judgment can easily lead to over- or under-adjustment, and the seatposts are prone to loosening due to vibration after tightening, posing a safety hazard. Secondly, seat clamping efficiency is low. Traditional bolt-fixing methods are time-consuming to install and remove, and long-term use can cause thread stripping, leading to seat positioning failure. Some quick-clamping structures exhibit uneven clamping force, causing wobbling during bumpy rides. Therefore, an adjustable seatpost mechanism is needed. Utility Model Content

[0003] Based on the existing technical problems, this utility model proposes an adjustable seat tube mechanism.

[0004] This utility model proposes an adjustable seat post mechanism, including a bicycle frame, a seat post installed at one end of the bicycle frame by screws, an adjustment device inside the seat post, the adjustment device including a seat, a support rod installed at the bottom of the seat, a snap-fit ​​groove at the bottom end of the support rod, and the bottom end of the support rod located inside the seat post; The adjustment device enables the seat to be quickly adjusted in the vertical direction.

[0005] Preferably, the adjusting device further includes a drive chamber with an opening inside the seat tube, the drive chamber being filled with hydraulic oil, and an oil replenishment pipe being installed on the inner side of the drive chamber. A compression spring is installed on the inner wall of one end of the oil replenishment pipe, and a sealing ball is installed on one end of the compression spring. The sealing ball is pressed against the inner wall of the other end of the oil replenishment pipe under the elastic force of the compression spring, and a sealing gasket is used to seal the oil replenishment pipe and the pressing surface of the sealing ball.

[0006] Preferably, a rectangular groove is provided on the inner wall of the bottom end of the drive cavity, a rectangular tube is slidably inserted into the inner wall of the rectangular groove, a drive piston is fixedly installed on the top end of the rectangular tube, and the arc surface of the drive piston is sealed and slidably sealed with the inner wall of the drive cavity through a sealing ring.

[0007] Preferably, the bottom surface of the seat tube is rotatably connected to a drive screw via a bearing, the top end of the drive screw penetrates and extends into the interior of the rectangular slide groove, and the threaded surface of the drive screw is threadedly connected to the inner wall of the rectangular tube, and an adjusting wheel is installed at the bottom end of the drive screw.

[0008] Preferably, a rectangular telescopic rod is slidably inserted into the top of the drive cavity, and a driven piston is installed at the bottom of the rectangular telescopic rod. The arc surface of the driven piston is sealed and slidably sealed with the inner wall of the drive cavity through a sealing ring. Large springs are installed in a ring array on the top of the driven piston, and the tops of the four large springs are all in pressure contact with the inner top wall of the drive cavity.

[0009] Preferably, the telescopic top of the rectangular telescopic rod is provided with a clamping groove, the bottom end of the support rod is inserted into the inside of the clamping groove, the inside of the rectangular telescopic rod is provided with a diversion hole and a clamping cavity, the bottom end of the diversion hole is connected to the inside of the drive cavity, and the top four diversion ports of the diversion hole are fixedly connected to the inner bottom wall of the four clamping cavities respectively.

[0010] Preferably, a clamping rod is slidably inserted into the inner wall of the clamping cavity, one end of the clamping rod is slidably inserted into the inner wall of the snap-fit ​​groove, and a clamping piston is fixedly installed at the other end of the clamping rod. The surface of the clamping piston is sealed and slidably sealed with the inner wall of the clamping groove through a sealing ring. A small spring is also installed on one side surface of the clamping piston. Two small springs are respectively located at both ends of the clamping rod, and one end of each of the two small springs is in pressure contact with the inner wall of the clamping groove. The elastic force of the small spring is less than that of the large spring.

[0011] The beneficial effects of this utility model are as follows: This device offers convenient and precise adjustment. Users rotate the ergonomic adjustment wheel, which, through the threaded transmission of the drive screw and rectangular tube, drives the drive piston to efficiently compress hydraulic oil. The cooperation between the rectangular groove and the rectangular tube ensures linear piston movement. Stable oil pressure pushes the driven piston and rectangular telescopic rod up and down. Combined with the quantifiable characteristics of the thread lead, precise control of seat height is achieved. Secondly, the seat clamping is efficient and reliable. The diversion hole guides oil pressure into the clamping cavity, driving the clamping rod to quickly engage with the support rod locking slot. The difference in elasticity between the small and large springs creates an orderly "clamp first, adjust later" logic, avoiding misalignment. Symmetrically distributed clamping rods provide balanced clamping force, ensuring the seat remains stable and secure during riding. Thirdly, the system is stable and durable. The sealing gasket and sealing ball of the oil replenishment pipe achieve bidirectional sealing, and the concealed design enhances damage resistance. Sealing rings at each piston prevent oil pressure loss, and the oil replenishment pipe allows for convenient replenishment of hydraulic oil, reducing maintenance costs. The large spring combines reset and cushioning functions, improving riding comfort. The overall structure is highly integrated, easy to operate, widely adaptable, and balances safety and practicality. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of an adjustable seat tube mechanism; Figure 2 A three-dimensional sectional view of a seat structure with an adjustable seat tube mechanism; Figure 3 A three-dimensional view of a seat structure with an adjustable seat post mechanism; Figure 4 An adjustable seat post mechanism Figure 2 Enlarged view of the structure at point A in the middle; Figure 5 An adjustable seat post mechanism Figure 2 Enlarged view of the structure at point B in the middle; Figure 6 An exploded three-dimensional view of the adjustment device for an adjustable seat post mechanism; Figure 7 An adjustable seat post mechanism Figure 6 Enlarged view of the structure at point C.

[0013] In the diagram: 1. Bicycle frame; 2. Seat post; 3. Adjustment device; 31. Seat; 32. Support rod; 33. Snap-fit ​​groove; 34. Drive chamber; 35. Oil supply pipe; 36. Compression spring; 37. Sealing ball; 38. Rectangular slide; 39. Rectangular tube; 310. Drive piston; 311. Drive screw; 312. Adjustment wheel; 313. Rectangular telescopic rod; 314. Driven piston; 315. Large spring; 316. Clamping groove; 317. Diverter hole; 318. Clamping chamber; 319. Clamping rod; 320. Clamping piston; 321. Small spring. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0015] Reference Figures 1-7 An adjustable seat post mechanism includes a bicycle frame 1, a seat post 2 is mounted on one end of the bicycle frame 1 by screws, an adjustment device 3 is provided inside the seat post 2, the adjustment device 3 includes a seat 31, a support rod 32 is mounted on the bottom of the seat 31, a snap-fit ​​groove 33 is opened at the bottom end of the support rod 32, and the bottom end of the support rod 32 is located inside the seat post 2.

[0016] The adjustment device 3 enables the seat 31 to be quickly adjusted in the vertical direction. The adjustment device 3 also includes a drive chamber 34 with an opening inside the seat tube 2. The drive chamber 34 is filled with hydraulic oil. The inner side of the drive chamber 34 is also connected to an oil supply pipe 35. A compression spring 36 is installed on the inner wall of one end of the oil supply pipe 35. A sealing ball 37 is installed on one end of the compression spring 36. The sealing ball 37 is pressed against the inner wall of the other end of the oil supply pipe 35 under the elastic force of the compression spring 36. The oil supply pipe 35 and the pressing surface of the sealing ball 37 are also sealed by a sealing gasket.

[0017] Specifically, this is implemented by using the pressure change of the hydraulic oil in the drive chamber 34 to drive the support rod 32 to rise and fall, thereby achieving the height adjustment of the seat 31. The design of the oil replenishment pipe 35 plays an important role in this process. When the hydraulic oil inside the drive chamber 34 experiences a slight leakage due to long-term use, the hydraulic oil can be conveniently replenished into the chamber through the oil replenishment pipe 35 without disassembling the main structure of the seat tube 2, which greatly reduces the difficulty and cost of maintenance and ensures that the hydraulic system is always maintained at the optimal working oil level. In addition, the oil replenishment pipe 35 adopts a hidden design and is integrated into the seat tube 2, which also has significant advantages. From a structural safety perspective, the concealed design prevents the fuel line 35 from being exposed and damaged by impacts, scratches, or other external forces during riding, preventing hydraulic oil leakage or sealing failure due to line damage, and further enhancing the mechanism's anti-interference capabilities. From an overall aesthetic perspective, the concealed design eliminates any protruding tubing components on the exterior of the seatpost 2, maintaining the bicycle's clean and streamlined structure, which meets the aesthetic design requirements of modern products. From a usability perspective, the concealed layout effectively prevents the tubing from getting tangled or snagged on the rider's clothing, weeds, or other objects in the riding environment, improving safety and comfort during riding.

[0018] A rectangular groove 38 is provided on the inner wall of the bottom end of the drive cavity 34. A rectangular tube 39 is slidably inserted into the inner wall of the rectangular groove 38. A drive piston 310 is fixedly installed on the top end of the rectangular tube 39. The arc surface of the drive piston 310 is sealed and slidably with the inner wall of the drive cavity 34 through a sealing ring.

[0019] Specifically, this structure achieves efficient transmission of driving force, ensuring a stable increase in oil pressure. The rectangular groove 38 guides the rectangular tube 39, causing the rectangular tube 39 to drive the drive piston 310 in a linear motion along the axis of the drive chamber 34. This avoids force dispersion caused by piston misalignment, ensuring that the piston's squeezing force on the hydraulic oil is fully applied to the oil within the chamber without additional force loss, thereby rapidly and stably increasing the oil pressure inside the drive chamber 34. This efficient pressure conversion capability allows the oil pressure to precisely reach the threshold for pushing the support rod 32 up and down.

[0020] Secondly, this structure ensures precise adjustment control by limiting circumferential rotation and radial offset. The non-circular fit between the rectangular tube 39 and the rectangular groove 38 structurally eliminates circumferential rotation of the rectangular tube 39, ensuring that the drive piston 310 always maintains the correct working posture. This prevents excessive local compression or sealing failure between the piston and the inner wall of the drive chamber 34, ensuring smooth oil pressure changes during adjustment and preventing sudden pressure rises and falls due to abnormal piston posture. This advantage directly translates into uniformity of seat 31 lifting speed, avoiding stuttering and jerking during adjustment, allowing users to precisely adjust the seat 31 to the target height.

[0021] The bottom surface of the seat tube 2 is rotatably connected to a drive screw 311 via a bearing. The top end of the drive screw 311 penetrates and extends into the interior of the rectangular slide groove 38, and the threaded surface of the drive screw 311 is threadedly connected to the inner wall of the rectangular tube 39. An adjusting wheel 312 is installed at the bottom end of the drive screw 311.

[0022] Specifically, this structure simplifies and reduces the effort required for adjustment. The adjusting wheel 312, as the direct operating component, provides a clear point of force application for the user. Its ergonomic size and rotation design conform to ergonomic principles, allowing users to easily rotate the wheel with just their hands, without the need for additional tools. The threaded connection between the drive screw 311 and the rectangular tube 39 forms a force-saving transmission mechanism, converting the rotational force applied by the user into the axial driving force of the rectangular tube 39. Through the deceleration and torque amplification effect of the thread, the rectangular tube 39 can overcome hydraulic oil resistance and slide along the rectangular groove 38 with minimal hand force, significantly reducing the physical barrier to adjustment and making it suitable for users of different ages and strengths, thus improving the mechanism's versatility.

[0023] Secondly, this transmission method ensures precise and controllable height adjustment of the seat 31. The threaded transmission inherently possesses advantages in displacement positioning. Each rotation of the drive screw 311 corresponds to the lifting distance of the rectangular tube 39, which in turn corresponds to the lead of the thread. This quantifiable transmission relationship gives the adjustment operation a clear "input-output" correspondence. By controlling the number of rotations and the rotation speed of the adjusting wheel 312, the user can precisely control the sliding stroke of the rectangular tube 39, thereby precisely adjusting the degree of hydraulic oil compression by the drive piston 310, achieving smooth changes in oil pressure, and ultimately adjusting the seat 31 height to the target position. Compared to adjustment methods without a positioning reference, this structure effectively avoids the problems of over- or under-adjustment, improves the accuracy of height adjustment, and meets the user's refined needs for riding posture.

[0024] Finally, this structure enhances the stability of the adjustment process and the reliability of locking. When the adjusting wheel 312 drives the drive screw 311 to rotate, the self-locking characteristic of the threaded connection allows the rectangular tube 39 to be stably locked in any position. When the wheel stops rotating, the thread friction between the drive screw 311 and the rectangular tube 39 can counteract the axial force on the rectangular tube 39, preventing the rectangular tube 39 from sliding under the pressure of hydraulic oil or the weight of the seat 31. This ensures that the seat 31 remains in the set position after height adjustment and will not descend or shift during use. At the same time, the cooperation between the drive screw 311 and the bearing reduces the frictional resistance during rotation, making the wheel rotate smoothly without jamming. Combined with the guiding effect of the rectangular groove 38 on the rectangular tube 39, the entire adjustment process is stable and orderly, further improving the user's operating experience.

[0025] A rectangular telescopic rod 313 is slidably inserted into the top of the drive cavity 34. A driven piston 314 is installed at the bottom of the rectangular telescopic rod 313. The arc surface of the driven piston 314 is sealed and slids against the inner wall of the drive cavity 34 through a sealing ring. A large spring 315 is installed in a ring array on the top of the driven piston 314. The tops of the four large springs 315 are all in contact with the inner top wall of the drive cavity 34.

[0026] Specifically, this process achieves efficient conversion of hydraulic energy into mechanical energy, providing stable power for height adjustment. The compression of hydraulic oil by the drive piston 310 uniformly increases the oil pressure within the drive chamber 34. This pressure is seamlessly transmitted to the driven piston 314 through the hydraulic oil medium. Utilizing the isotropic nature of liquid pressure transmission, the driven piston 314 is ensured to receive uniform force, avoiding jamming caused by localized force concentration. Simultaneously, the buffering characteristics of hydraulic transmission absorb instantaneous impact forces during the adjustment process, ensuring smooth and orderly movement of the driven piston 314. This, in turn, drives the rectangular telescopic rod 313 to extend at a uniform speed, providing continuous and stable power support for the height adjustment of the seat 31, preventing the seat 31 from wobbling or experiencing sudden rises or falls during the adjustment process.

[0027] Secondly, the compression of the large spring 315 and the extension of the rectangular telescopic rod 313 are linked to ensure precise control and position locking of the height adjustment. When the hydraulic pressure drives the driven piston 314 to compress the large spring 315, the degree of elastic deformation of the large spring 315 is linearly related to the magnitude of the hydraulic pressure. That is, the greater the hydraulic pressure, the greater the spring compression, and the longer the extension length of the rectangular telescopic rod 313. This clear "pressure-stroke" correspondence provides a quantifiable control benchmark for the height adjustment of the seat 31. Users can precisely adjust the hydraulic pressure by controlling the movement amplitude of the drive piston 310, thereby precisely controlling the extension distance of the rectangular telescopic rod 313, achieving fine-tuned adjustment of the seat 31 height to meet the personalized needs of users of different heights or in different riding scenarios. At the same time, the elastic force of the large spring 315 and the hydraulic oil pressure form a dynamic balance. When the adjustment stops, this balance allows the driven piston 314 and the rectangular telescopic rod 313 to remain stably in their current positions, achieving reliable locking of the seat 31 height and preventing height deviation caused by external disturbances during use.

[0028] Finally, the large spring 315 provides the mechanism with excellent reset performance and cushioning protection. When the seat 31 needs to be lowered, the oil pressure in the drive chamber 34 decreases, and the compressed large spring 315, under the action of elastic restoring force, pushes the driven piston 314 downward, causing the rectangular telescopic rod 313 to retract, while simultaneously squeezing the hydraulic oil back into the lower part of the drive chamber 34, completing the adjustment and reset. This spring reset mechanism requires no additional power drive, simplifying the mechanism structure while ensuring a smooth and efficient reset process. In addition, the large spring 315 can serve as an auxiliary cushioning component for the seat 31 in daily use. When encountering bumpy roads while riding, the elastic deformation of the large spring 315 can absorb some of the vibration and impact force, which is transmitted to the seat 31 through the rectangular telescopic rod 313, improving the comfort of the riding process and realizing the dual value of "adjustment function" and "cushioning function".

[0029] The telescopic top of the rectangular telescopic rod 313 is provided with a clamping groove 316, and the bottom end of the support rod 32 is inserted into the inside of the clamping groove 316. The inside of the rectangular telescopic rod 313 is provided with a diversion hole 317 and a clamping cavity 318. The bottom end of the diversion hole 317 is connected to the inside of the drive cavity 34, and the top four diversion ports of the diversion hole 317 are fixedly connected to the inner bottom wall of the four clamping cavities 318 respectively.

[0030] A clamping rod 319 is slidably inserted into the inner wall of the clamping cavity 318. One end of the clamping rod 319 is slidably inserted into the inner wall of the snap-fit ​​groove 33. A clamping piston 320 is fixedly installed at the other end of the clamping rod 319. The surface of the clamping piston 320 is sealed and slidably sealed with the inner wall of the clamping groove 316 through a sealing ring. A small spring 321 is also installed on one side surface of the clamping piston 320. The two small springs 321 are located at the two ends of the clamping rod 319 respectively, and one end of each of the two small springs 321 is in contact with the inner wall of the clamping groove 316. The elastic force of the small spring 321 is less than that of the large spring 315.

[0031] Specifically, the hydraulic pressure diversion design of the diversion hole 317 enables rapid clamping and efficient positioning of the seat 31. Increased hydraulic pressure inside the drive chamber 34 is precisely introduced into the clamping chamber 318 through the diversion hole 317. Utilizing the instantaneous nature of hydraulic transmission, this pressure rapidly acts on the clamping piston 320, pushing the clamping rod 319 outward. This allows the clamping rod 319 to quickly engage with the locking groove 33 of the seat 31's support rod 32, completing the mechanical positioning of the seat 31. Compared to traditional bolt-fixing clamping methods, this hydraulically driven clamping structure requires no additional tools; clamping and detachment are achieved simply by adjusting the hydraulic pressure, significantly shortening the installation and disassembly time of the seat 31 and improving assembly efficiency. Simultaneously, the symmetrical distribution of the four clamping chambers 318 ensures that the clamping rod 319 exerts a uniform clamping force on the support rod 32, guaranteeing a balanced force on the seat 31 after installation and preventing installation misalignment or loosening.

[0032] Secondly, the design of the elastic force difference between the small spring 321 and the large spring 315 establishes an orderly action logic of "clamping first, then adjusting". Since the elastic force of the small spring 321 is less than that of the large spring 315, as the hydraulic pressure gradually increases, the hydraulic pressure will first overcome the elastic resistance of the small spring 321 to drive the clamping piston 320. Only after the clamping rod 319 is fully embedded in the locking groove 33 and the small spring 321 is compressed to its limit state will the hydraulic pressure continue to accumulate and overcome the elastic force of the large spring 315 to drive the driven piston 314, thus realizing the extension and retraction of the rectangular telescopic rod 313 and the height adjustment of the seat 31. This action sequence control based on elastic force difference structurally avoids the installation misalignment problem caused by the synchronous movement of the seat 31 with the telescopic rod when clamping is not complete, ensuring that the seat 31 is reliably positioned before height adjustment. It also prevents relative sliding between the seat 31 and the telescopic rod during adjustment, ensuring the stability and accuracy of the adjustment action.

[0033] Finally, the integrated design of the clamping structure and hydraulic system enhances the reliability and safety of seat 31 installation. The sealing ring design between the clamping piston 320 and the inner wall of the clamping cavity 318 ensures no leakage of oil pressure flowing into the clamping cavity 318, allowing the clamping rod 319 to maintain a stable clamping force. Even when encountering bumps and vibrations during riding, the clamping rod 319 remains firmly engaged in the locking groove 33, preventing the seat 31 from loosening or shaking, providing a solid guarantee for riding safety. Simultaneously, the elastic return characteristic of the small spring 321 gives the clamping structure excellent self-adaptability—when the oil pressure decreases, the small spring 321 pushes the clamping piston 320 back to its original position, causing the clamping rod 319 to disengage from the locking groove 33, facilitating quick disassembly and replacement of the seat 31 and enabling convenient operation throughout the entire "clamping-adjustment-disassembly" process. Furthermore, the integrated design of the clamping structure and the rectangular telescopic rod 313 eliminates the need for additional independent clamping components, simplifying the overall structure of the seat post 2 mechanism and reducing assembly errors and maintenance costs.

[0034] This device offers convenient and precise adjustment. Users rotate the ergonomic adjustment wheel 312, which, through the threaded transmission of the drive screw 311 and rectangular tube 39, drives the drive piston 310 to efficiently compress hydraulic oil. The cooperation between the rectangular groove 38 and the rectangular tube 39 ensures linear piston movement. Stable oil pressure pushes the driven piston 314 and rectangular telescopic rod 313 up and down. Combined with the quantifiable characteristics of the thread lead, precise control of the seat 31's height is achieved. Secondly, the seat 31 clamping is efficient and reliable. The diversion hole 317 guides oil pressure into the clamping cavity 318, driving the clamping rod 319 to quickly engage with the support rod 32's locking groove 33. The difference in elasticity between the small spring 321 and the large spring 315 creates an orderly "clamp first, adjust later" logic, preventing misalignment. The symmetrically distributed clamping rods 319 provide balanced clamping force, ensuring the seat 31 remains stable and secure during riding. Thirdly, the system is stable and durable. The sealing gasket and sealing ball 37 of the oil replenishment pipe 35 achieve bidirectional sealing, and the concealed design enhances its resistance to damage. The sealing rings at each piston prevent oil pressure loss, and the oil replenishment pipe 35 facilitates the replenishment of hydraulic oil, reducing maintenance costs. The large spring 315 has both reset and buffer functions, improving riding comfort. The overall structure has a high degree of integration, is easy to operate, has wide adaptability, and balances safety and practicality.

[0035] Working principle: During adjustment, the adjusting wheel 312 at the bottom of the seat tube 2 is manually rotated. The wheel drives the drive screw 311, which is connected by a bearing, to rotate. The drive screw 311 engages with the threaded connection of the rectangular tube 39, converting the rotational force into the axial driving force of the rectangular tube 39, causing the rectangular tube 39 to slide linearly along the rectangular groove 38 at the bottom of the drive cavity 34. The drive piston 310 at the top of the rectangular tube 39 moves with the rectangular tube 39, compressing the hydraulic oil in the drive cavity 34 and increasing the oil pressure. A portion of the high-pressure oil is introduced into the clamping cavity 318 in the rectangular telescopic rod 313 through the diversion hole 317, pushing the clamping piston 320 to overcome the elastic force of the small spring 321, causing the clamping rod 319 to extend outward and engage with the snap-fit ​​groove 33 of the seat 31 support rod 32, completing the quick clamping and positioning of the seat 31. Because the force of the small spring 321 is less than that of the large spring 315, after clamping, the small spring 321 is compressed to its limit, and the oil pressure continues to rise and acts on the driven piston 314 at the top of the drive chamber 34, pushing the driven piston 314 to overcome the force of the large spring 315 and move upward, driving the rectangular telescopic rod 313 to extend synchronously, thereby raising the height of the seat 31. When the adjusting wheel 312 stops rotating, the self-locking characteristic of the thread between the drive screw 311 and the rectangular tube 39 fixes the position of the rectangular tube 39, and the oil pressure in the drive chamber 34 stabilizes. At the driven piston 314, the hydraulic oil pressure and the force of the large spring 315 form a dynamic balance, the rectangular telescopic rod 313 maintains a fixed length, and the height of the seat 31 is reliably locked. Reversing the rotation of the adjusting wheel 312 causes the drive screw 311 to move the rectangular tube 39 downward, and the drive piston 310 resets, reducing the oil pressure in the drive chamber 34. The elastic restoring force of the large spring 315 pushes the driven piston 314 downward, causing the rectangular telescopic rod 313 to retract. Simultaneously, hydraulic oil flows back to the lower part of the drive chamber 34. The oil pressure in the clamping chamber 318 decreases, and the small spring 321 pushes the clamping piston 320 to reset. The clamping rod 319 disengages from the locking groove 33, facilitating the removal or readjustment of the seat 31. At the oil replenishment pipe 35, the sealing ball 37 achieves a bidirectional seal under the action of the compression spring 36 and the sealing gasket, preventing hydraulic oil leakage and impurities from entering. When hydraulic oil is depleted due to long-term use, it can be easily replenished through the oil replenishment pipe 35 to maintain the system's optimal operating condition.

[0036] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An adjustable seatpost mechanism, comprising a bicycle frame (1), characterized in that: One end of the bicycle frame (1) is fitted with a seat post (2) by screws. An adjustment device (3) is provided inside the seat post (2). The adjustment device (3) includes a seat (31). A support rod (32) is installed at the bottom of the seat (31). A snap-fit ​​groove (33) is provided at the bottom end of the support rod (32). The bottom end of the support rod (32) is located inside the seat post (2). The adjustment device (3) enables the seat (31) to be quickly adjusted in the vertical direction.

2. The adjustable seat tube mechanism according to claim 1, characterized in that: The adjusting device (3) also includes a drive chamber (34) with a seat tube (2) inside. The drive chamber (34) is filled with hydraulic oil. The inner side of the drive chamber (34) is also connected to an oil replenishment pipe (35). A compression spring (36) is installed on the inner wall of one end of the oil replenishment pipe (35). A sealing ball (37) is installed on one end of the compression spring (36). The sealing ball (37) is pressed against the inner wall of the other end of the oil replenishment pipe (35) under the elastic force of the compression spring (36). The oil replenishment pipe (35) and the compression surface of the sealing ball (37) are also sealed by a sealing gasket.

3. The adjustable seat tube mechanism according to claim 2, characterized in that: The bottom inner wall of the drive cavity (34) is provided with a rectangular slide groove (38), and a rectangular tube (39) is slidably inserted into the inner wall of the rectangular slide groove (38). A drive piston (310) is fixedly installed at the top of the rectangular tube (39). The arc surface of the drive piston (310) is sealed and slid with the inner wall of the drive cavity (34) through a sealing ring.

4. The adjustable seat tube mechanism according to claim 3, characterized in that: The bottom surface of the seat tube (2) is rotatably connected to a drive screw (311) via a bearing. The top end of the drive screw (311) extends through and into the interior of the rectangular slide groove (38), and the threaded surface of the drive screw (311) is threadedly connected to the inner wall of the rectangular tube (39). An adjusting wheel (312) is installed at the bottom end of the drive screw (311).

5. An adjustable seat tube mechanism according to claim 2, characterized in that: A rectangular telescopic rod (313) is slidably inserted into the top of the drive cavity (34), and a driven piston (314) is installed at the bottom of the rectangular telescopic rod (313). The arc surface of the driven piston (314) is sealed and slidably sealed with the inner wall of the drive cavity (34) through a sealing ring. A large spring (315) is installed in a ring array on the top of the driven piston (314), and the tops of the four large springs (315) are all in contact with the inner top wall of the drive cavity (34).

6. The adjustable seat tube mechanism according to claim 5, characterized in that: The telescopic top of the rectangular telescopic rod (313) is provided with a clamping groove (316), and the bottom end of the support rod (32) is inserted into the inside of the clamping groove (316). The inside of the rectangular telescopic rod (313) is provided with a diversion hole (317) and a clamping cavity (318). The bottom end of the diversion hole (317) is connected to the inside of the drive cavity (34), and the four diversion ports at the top of the diversion hole (317) are fixedly connected to the inner bottom wall of the four clamping cavities (318).

7. An adjustable seat tube mechanism according to claim 6, characterized in that: A clamping rod (319) is slidably inserted into the inner wall of the clamping cavity (318). One end of the clamping rod (319) is slidably inserted into the inner wall of the snap-fit ​​groove (33). A clamping piston (320) is fixedly installed at the other end of the clamping rod (319). The surface of the clamping piston (320) is sealed and slidably sliding with the inner wall of the clamping groove (316) through a sealing ring. A small spring (321) is also installed on one side surface of the clamping piston (320). The two small springs (321) are located at the two ends of the clamping rod (319), and one end of each of the two small springs (321) is pressed and contacted with the inner wall of the clamping groove (316). The elastic force of the small spring (321) is less than that of the large spring (315).

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