A new kind of hollow piston rod recovery damping force adjustable mechanism

Abstract

The application relates to the field of shock absorbers, and discloses a novel recovery damping force adjustable mechanism of a hollow piston rod, which comprises a hollow piston rod, one end of the hollow piston rod is fixedly sleeved with a recovery valve assembly, the recovery valve assembly is provided with a first oil path penetrating through front and back end faces, a second oil path is arranged in the length direction of the center of one end of the hollow piston rod close to the recovery valve assembly, the second oil path is composed of straight-through through holes and branch through holes which are connected with each other and arranged vertically, the straight-through through holes extend to the outside of the recovery valve assembly, and the branch through holes are arranged through the circumferential surface of the hollow piston rod outside the recovery valve assembly; the application provides basic flow through the first oil path with a fixed section, realizes total flow regulation and control only by changing the annular gap flow area of the second oil path, can weaken the flow-pressure difference nonlinear characteristics of the traditional single throttle hole adjusting structure, and avoids the damping jump problem caused by the dynamic flow distribution deviation of the double oil paths.

Description

Technical Field

[0001] This application relates to the field of shock absorbers, and in particular to a novel adjustable mechanism for the restoring damping force of a hollow piston rod. Background Technology

[0002] Shock absorbers are the core components of a car's suspension system. Their function is to absorb vibrations caused by uneven road surfaces during vehicle operation, thereby improving ride comfort and handling stability. The damping force of the shock absorber directly affects the damping effect. Different road conditions and driving styles have different requirements for damping force. Traditional shock absorbers have fixed damping force, which cannot be adjusted according to actual needs, making it difficult to balance comfort and handling. To solve this problem, adjustable damping shock absorbers have emerged.

[0003] Regarding the aforementioned technologies, the inventors believe that the currently mass-produced dual-oil-circuit adjustable damper, due to the nonlinear characteristics of the flow-pressure difference of the throttle orifice itself, coupled with the dynamic flow distribution deviation of the two oil circuits during the adjustment process, will directly break the linear law of damping output, resulting in uneven damping force jumps during gear adjustment, ultimately reducing the damping adjustment accuracy and making it difficult to guarantee the stable and uniform damping effect in all scenarios.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Utility Model Content

[0005] To address the problem of unstable damping adjustment in traditional dual-oil-circuit shock absorbers, this application provides a novel adjustable mechanism for the restoring damping force of a hollow piston rod.

[0006] The novel adjustable damping force mechanism for hollow piston rods provided in this application adopts the following technical solution: A novel adjustable mechanism for the restoring damping force of a hollow piston rod includes a hollow piston rod, one end of which is fixedly sleeved with a restoring valve assembly. The recovery valve assembly has a first oil passage that runs through and connects its front and rear ends. The hollow piston rod has a second oil passage along its length at the center of one end near the recovery valve assembly. The second oil passage is composed of a combination of a direct flow hole and a branch flow hole that are interconnected and perpendicularly arranged. The direct flow hole extends to the outside of the recovery valve assembly, and the branch flow hole penetrates the circumference of the hollow piston rod on the outside of the recovery valve assembly. The first oil circuit and the second oil circuit are connected in parallel. An adjusting core rod is slidably disposed in the hollow piston rod. One end of the adjusting core rod has a frustum structure and is connected to the DC through hole. The frustum end of the adjusting core rod extends into the DC through hole to adjust the flow area of ​​the second oil passage.

[0007] Preferably, a lifting ring connector is fixedly installed at the end of the hollow piston rod away from the recovery valve assembly. A recovery adjustment knob is rotatably installed inside the lifting ring connector. An eccentric block is fixedly connected to the bottom end of the recovery adjustment knob. When the recovery adjustment knob is rotated, the eccentric block pushes the adjustment core rod to move axially.

[0008] Preferably, an adjustment rod return spring is provided at the end of the adjustment core rod away from the lifting ring connector, and the adjustment rod return spring is used to keep one end of the adjustment core rod in contact with the eccentric block.

[0009] Preferably, a throttling mandrel is fixedly installed on the inner wall of the DC through hole by means of bolts. The inner wall of the throttling mandrel is connected to the DC through hole. An annular gap is formed between the inner wall of the throttling mandrel and the outer wall of the cone of the adjusting mandrel to allow the oil in the second oil circuit to flow.

[0010] Preferably, the outer periphery of the recovery adjustment knob is provided with several equidistantly distributed positioning grooves, and the inner wall of the lifting ring connector is provided with a corresponding receiving groove. A limiting steel ball and a knob spring are installed in sequence in the receiving groove. The limiting steel ball is embedded in the positioning groove under the elastic force of the knob spring, thereby realizing the mechanical locking of each adjustment position of the recovery adjustment knob. Moreover, the axial displacement of the adjustment core rod corresponding to each position increases in an arithmetic progression, and the damping force change gradient between different positions is uniform.

[0011] Preferably, a dynamic seal is provided between the outer peripheral wall of the adjusting core rod and the inner wall of the hollow piston rod. The dynamic seal is two fluororubber O-rings, which maintain a dynamic seal throughout the axial sliding process of the adjusting core rod, blocking the internal leakage path of oil inside the hollow piston rod.

[0012] In summary, this application includes the following beneficial technical effects: By providing the basic flow rate through the first oil circuit with a fixed cross-section, and adjusting the total flow rate solely by changing the flow area of ​​the annular gap in the second oil circuit, the nonlinear characteristics of the flow-pressure difference in the traditional single-throttle-hole adjustment structure can be weakened, and the damping jump problem caused by the dynamic flow distribution deviation of the dual oil circuits can be avoided. Compared with the existing technology, the structure of parallel oil circuits can make the damping force show an approximately increasing trend with the knob gear, improving the problems of sudden damping changes in the middle gear and excessive damping differences between the first and last gears that are prone to occur in traditional adjustable shock absorbers. Attached Figure Description

[0013] Figure 1This is a schematic diagram of the overall structure of a novel adjustable damping force mechanism for a hollow piston rod according to an embodiment of the application. Figure 2 This is a schematic diagram of the adjusting core rod structure according to an embodiment of the application; Figure 3 This is a schematic diagram of the structure at point A in the embodiment of the application; Figure 4 This is a schematic diagram of the restoration adjustment knob structure in the embodiment of the application; Figure 5 This is a top view of the structure of an embodiment of the application; Figure 6 This is a schematic diagram of the eccentric block structure in an embodiment of the application.

[0014] Explanation of reference numerals in the attached diagram: 1. Hollow piston rod; 2. Adjusting core rod; 3. First oil passage; 4. Second oil passage; 41. Branch through hole; 42. Direct flow through hole; 5. Lifting ring connector; 6. O-ring seal; 7. Adjusting rod return spring; 8. Throttling core rod; 9. Reset valve assembly; 10. Reset adjusting knob; 11. Eccentric block; 12. Limiting steel ball; 13. Knob spring. Detailed Implementation

[0015] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0016] This application discloses a novel adjustable damping force mechanism for a hollow piston rod, which is coaxially assembled inside the piston rod assembly of the shock absorber. (Refer to...) Figure 1 - Figure 2 The system includes a lifting ring connector 5, a hollow piston rod 1, and a return valve assembly 9, which are coaxially assembled in sequence. The top of the lifting ring connector 5 is used to hinge with the hanger structure of the vehicle suspension. The bottom of the lifting ring connector 5 is coaxially fixed to the hollow piston rod 1 by interference fit and circumferential spot welding. The end of the hollow piston rod 1 away from the lifting ring connector 5 is fixedly sleeved with the return valve assembly 9. The coaxiality tolerance of all connecting parts is controlled within 0.02mm to avoid sliding and jamming problems caused by different axiality.

[0017] Reference Figure 2 and Figure 3The first oil passage 3 and the second oil passage 4 are respectively opened on the recovery valve assembly 9 and the hollow piston rod 1. The oil inlet of the two oil passages are directly connected to the working chamber of the shock absorber. After the oil enters the working chamber of the shock absorber, it flows out directly through the first oil passage 3 in the recovery valve assembly 9. The oil flow rate of this oil passage is adjusted only by the passive adjustment effect of the recovery valve assembly 9 itself. As the basic flow channel of the entire damping system, it ensures that the shock absorber has basic recovery damping force in any gear, and avoids suspension swaying caused by insufficient damping force. The second oil passage 4 consists of interconnected branch through holes 41 and direct through holes 42. The branch through holes 41 are oil inlets, which are opened through the circumference of the hollow piston rod 1 located outside the recovery valve assembly 9. The direct through holes 42 are oil outlets, which are opened through the interior of the hollow piston rod 1. The second oil passage 4 is an adjustable oil passage. A cylindrical adjusting core rod 2 is slidably mounted on the inner wall of the hollow piston rod 1 along the axial direction. When the adjusting core rod 2 is axially displaced, the flow area of ​​the second oil passage 4 will be continuously changed, thereby regulating the oil flow rate of the second oil passage 4. After the oil enters from the working cavity of the shock absorber, it will flow through the second oil passage 4 in the center of the hollow piston rod 1 and enter the downstream oil cavity.

[0018] The first oil circuit 3 and the second oil circuit 4 form a parallel oil supply relationship: the inlet ends of the two oil circuits are connected to the working cavity of the shock absorber, and the outlet ends are connected to the downstream oil cavity. The total recovery oil flow rate is the sum of the flow rate of the first oil circuit 3 and the flow rate of the second oil circuit 4. Among them, the first oil circuit 3 is the basic oil circuit, and its flow rate is passively adjusted by the elastic valve plate inside the recovery valve assembly 9 according to the oil pressure difference; the second oil circuit 4 is an adjustable oil circuit, and its flow area is actively controlled by the adjusting core rod 2 and is not affected by the deformation of the elastic valve plate.

[0019] Reference Figure 3 , Figure 4 as well as Figure 6 The lifting ring connector 5 has a rotating reset adjustment knob 10 inside. The bottom end of the reset adjustment knob 10 extends to the position of the hollow piston rod 1 and is coaxially fixedly connected to an eccentric block 11. The outer contour of the eccentric block 11 is a continuous and smooth arc eccentric surface. When the operator rotates the reset adjustment knob 10, the eccentric contour of the eccentric block 11 will gradually squeeze the adjusting core rod 2, realizing the axial movement effect of the adjusting core rod 2. When the reset adjustment knob 10 is turned to the second position, the adjusting core rod 2 moves towards the reset valve assembly 9, the gap between the adjusting core rod 2 and the DC through hole 42 decreases, and the flow rate through the second oil passage 4 decreases accordingly, thus increasing the reset damping force. Similarly, when the reset adjustment knob 10 is turned to the maximum position eight, the gap between the adjusting core rod 2 and the DC through hole 42 is completely blocked, and very little oil flows out of the second oil passage 4. At this time, the flow rate through the second oil passage 4 becomes the minimum, thus generating the maximum reset damping force.

[0020] Furthermore, a spring positioning blind hole is provided on the end face of the adjusting core rod 2 away from the lifting ring connector 5. The top end of the adjusting rod return spring 7 is embedded in the blind hole. In the absence of external driving force, the adjusting rod return spring 7 will always apply a rebound force to the adjusting core rod 2, ensuring that the top surface of the adjusting core rod 2 always keeps in close contact with the contour surface of the eccentric block 11, and there will be no problem of separation or jamming. Through the rebound force of the adjusting core rod 2 in conjunction with the adjusting rod return spring 7, the adjusting core rod 2 can be driven to complete the reciprocating linear movement along the axial direction, effectively avoiding the problems of thread wear and gap movement that are prone to occur in traditional threaded adjustment structures.

[0021] Reference Figure 2 and Figure 3 A throttling core rod 8 is fixedly installed on the inner wall of the DC through hole 42 by means of bolts. The interior of the throttling core rod 8 is connected to the branch through hole 41, and the cone end of the adjusting core rod 2 can be inserted into the inner hole of the throttling core rod 8. An annular gap is formed between the inner wall of the throttling core rod 8 and the outer wall of the cone of the adjusting core rod 2 to allow the oil in the second oil passage 4 to flow.

[0022] Reference Figure 4 and Figure 6 The outer circumferential surface of the adjustment knob 10 has eight equidistant circumferentially distributed positioning grooves. Correspondingly, the inner wall of the hanging ring connector 5 has a radially extending circular receiving groove. A limiting steel ball 12 and a knob spring 13 are sequentially inserted into the receiving groove. Under the radial elastic force of the knob spring 13, the limiting steel ball 12 can accurately embed into the positioning grooves at different positions, achieving mechanical locking of the eight adjustment positions and preventing the gears from shifting during high-frequency vibrations of vehicle operation. The axial displacement of the adjustment core rod 2 corresponding to the eight positions is controlled to increase arithmetically, ensuring a uniform gradient of damping force between different positions and preventing excessively large or small differences in damping force between adjacent positions.

[0023] Reference Figure 2 Two O-rings 6 made of fluororubber are provided between the outer wall of the adjusting core rod 2 and the inner wall of the hollow piston rod 1. The O-rings 6 are arranged axially at intervals. The O-rings 6 maintain dynamic sealing throughout the axial sliding process of the adjusting core rod 2, blocking the internal leakage path of oil inside the hollow piston rod 1 and effectively covering the working oil pressure range of conventional passenger car shock absorbers.

[0024] The basic oil passage is achieved through two symmetrically arranged elastic valve plates in the recovery valve assembly 9. The two sets of elastic valve plates are arranged in a mirror symmetrical manner with the center plane of the recovery valve assembly 9 as the reference. When the oil in the first oil passage 3 passes through, it pushes the two elastic valve plates to deform, and the oil flows out from the gap in the elastic valve plates, thereby achieving the basic flow effect of the recovery valve assembly 9. The elastic valve plates are connected in series in the oil passage of the first oil passage 3. Only the oil in the first oil passage 3 flows through the elastic valve plates and is throttled by them. The second oil passage 4 is independently opened on the hollow piston rod 1 and does not pass through the interior of the recovery valve assembly 9. Therefore, the deformation of the elastic valve plates does not affect the flow area of ​​the second oil passage 4. Specifically, when the shock absorber is in the low-speed extension stroke, the pressure difference of the oil in the working chamber is low, and the two sets of symmetrically arranged elastic valves hardly deform. The oil flows only through the normally open throttling grooves on the two sets of elastic valves, outputting a gentle and stable small damping, accurately filtering out minor road bumps, and avoiding unnecessary high-frequency aftershocks on the vehicle body. When the shock absorber enters the medium-to-high-speed extension stroke, the pressure difference of the oil gradually increases. Under completely equal force conditions, the two sets of symmetrically arranged elastic valves deform outwards uniformly, expanding the flow channels inside the elastic valves and increasing the throughput of the first oil circuit 3, thereby outputting a linearly increasing damping force, quickly dissipating the energy of large vibrations, and avoiding the damping abrupt change problem caused by the uneven wear of the traditional single-sided valve.

[0025] The implementation principle of the novel adjustable damping force mechanism for a hollow piston rod in this application embodiment is as follows: When the shock absorber is in the extension stroke, the oil in the working chamber of the shock absorber simultaneously flows into two oil passages. The total recovery oil flow rate is the sum of the basic flow rate of the first oil passage 3 and the adjustable flow rate of the second oil passage 4. Since the flow rate of the first oil passage 3 is passively changed through the recovery valve assembly 9, the total flow rate can be adjusted only by changing the flow area of ​​the annular gap of the second oil passage 4. This can weaken the nonlinear characteristics of the flow-pressure difference of the traditional single-throttle-hole adjustment structure and avoid the damping jump problem caused by the dynamic flow distribution deviation of the dual oil passages.

[0026] This embodiment employs a parallel oil supply structure with the first oil circuit 3 and the second oil circuit 4. The first oil circuit 3 outputs a stable base flow rate, while the second oil circuit 4 actively adjusts the flow area. This structure can mitigate the nonlinear effects of throttling, reduce damping jumps, and improve uneven damping changes between different gears. It can adapt to various driving scenarios such as urban roads, bumpy off-road driving, and high-speed cornering, ensuring stable and consistent shock absorption performance across all scenarios.

[0027] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A novel adjustable mechanism for the restoring damping force of a hollow piston rod, comprising a hollow piston rod (1), characterized in that: One end of the hollow piston rod (1) is fixedly sleeved with a restoration valve assembly (9). The recovery valve assembly (9) has a first oil passage (3) that runs through and connects its front and rear ends. The hollow piston rod (1) has a second oil passage (4) along its length at the center of one end near the recovery valve assembly (9). The second oil passage (4) is composed of a direct through hole (42) and a branch through hole (41) that are interconnected and perpendicularly arranged. The direct through hole (42) extends to the outside of the recovery valve assembly (9), and the branch through hole (41) penetrates the circumference of the hollow piston rod (1) on the outside of the recovery valve assembly (9). The first oil circuit (3) and the second oil circuit (4) are connected in parallel; An adjusting core rod (2) is slidably disposed in the hollow piston rod (1). One end of the adjusting core rod (2) is a frustum structure and is connected to the DC through hole (42). The frustum end of the adjusting core rod (2) extends into the DC through hole (42) to adjust the flow area of ​​the second oil passage (4).

2. The novel adjustable restoring damping force mechanism for a hollow piston rod according to claim 1, characterized in that: The hollow piston rod (1) is fixedly mounted with a lifting ring connector (5) at one end away from the recovery valve assembly (9). The recovery adjustment knob (10) is rotatably mounted inside the lifting ring connector (5). An eccentric block (11) is fixedly connected to the bottom end of the recovery adjustment knob (10). When the recovery adjustment knob (10) is rotated, the eccentric block (11) pushes the adjustment core rod (2) to move axially.

3. The novel adjustable restoring damping force mechanism for a hollow piston rod according to claim 1, characterized in that: An adjustment rod return spring (7) is provided at the end of the adjustment rod (2) away from the lifting ring connector (5). The adjustment rod return spring (7) is used to keep one end of the adjustment rod (2) in contact with the eccentric block (11).

4. The novel adjustable restoring damping force mechanism for a hollow piston rod according to claim 1, characterized in that: A throttling mandrel (8) is fixedly installed on the inner wall of the DC through hole (42) by means of bolts. The inner wall of the throttling mandrel (8) is connected to the DC through hole (42). An annular gap is formed between the inner wall of the throttling mandrel (8) and the outer wall of the cone of the adjusting mandrel (2) to allow the oil in the second oil passage (4) to flow.

5. The novel adjustable restoring damping force mechanism for a hollow piston rod according to claim 2, characterized in that: The outer periphery of the recovery adjustment knob (10) is provided with several equidistantly distributed positioning grooves. The inner wall of the lifting ring connector (5) is provided with a corresponding receiving groove. The receiving groove is installed in sequence with a limiting steel ball (12) and a knob spring (13). The limiting steel ball (12) is embedded in the positioning groove under the elastic force of the knob spring (13), thereby realizing the mechanical locking of each adjustment position of the recovery adjustment knob (10). The axial displacement of the adjustment core rod (2) corresponding to each position increases in an arithmetic progression, and the damping force change gradient between different positions is uniform.

6. The novel adjustable restoring damping force mechanism for a hollow piston rod according to claim 1, characterized in that: A dynamic seal is provided between the outer peripheral wall of the adjusting core rod (2) and the inner wall of the hollow piston rod (1). The dynamic seal consists of two O-rings (6) made of fluororubber, which maintain dynamic sealing throughout the axial sliding process of the adjusting core rod (2) and block the internal leakage path of oil inside the hollow piston rod (1).

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