Rigidity-adjustable independent air spring

Abstract

The utility model belongs to the technical field of automobile suspensions, and particularly relates to a rigidity-adjustable independent air spring which comprises a base, an air bag and a piston, the lower end of the air bag is fixedly connected to the outer side wall of the base, and the upper end of the air bag is fixedly connected to the outer side wall of the piston. The piston is provided with an axial through stepped hole, and a large hole of the stepped hole and a small hole of the stepped hole are coaxially arranged up and down; an axial adjusting seat is arranged in the large hole, and the side wall of the axial adjusting seat is in threaded connection with the hole wall of the large hole; a sealing plug axially following the axial adjusting seat is arranged in the small hole, and the sealing plug is in sealing fit with the small hole; the base, the air bag, the piston and the sealing plug define a closed air chamber. The axial adjusting seat drives the sealing plug to synchronously and axially move to adjust the volume of the air chamber of the air spring, stepless adjustment of the rigidity of the air spring is achieved, the rigidity adjusting range is large, the adjusting precision is high, the air spring can be adjusted to the specified rigidity according to needs, and adaptability is high. The structure is simple and cost is low. The sealing plug can be assembled and disassembled through the large hole and is convenient to maintain.

Description

Technical Field

[0001] The utility model belongs to the technical field of automobile suspension, and in particular relates to an independent air spring with adjustable stiffness. Background Art

[0002] Independent air springs are assembled separately from the shock absorber and are suitable for high-end sedans, SUVs, and other vehicles. They provide excellent cushioning against bumpy roads. Existing independent air springs primarily consist of a base, an airbag, a piston, and a protective tube attached to the outer wall of the airbag. The lower end of the airbag is sealed to the base, while the upper end is sealed to the lower end of the piston. The base, airbag, and piston form a sealed air chamber. The base is connected to the wheel carrier, and the piston is connected to the suspension. The protective tube defines the outer diameter of the airbag and protects it.

[0003] The stiffness characteristics of independent air springs significantly impact vehicle comfort and handling stability. The stiffness curve of an air spring is determined by the vehicle manufacturer through theoretical calculations and on-vehicle calibration, and cannot be adjusted after the vehicle leaves the factory. With increasing demand for enhanced ride comfort, some high-end vehicles are adopting multi-chamber independent air springs to meet the stiffness requirements for varying road conditions. These air springs consist of multiple chambers, and solenoid valves control the connectivity between the chambers to adjust the effective volume of the air spring, switching the stiffness curve as needed. The solenoid valves are typically controlled by an ECU (on-board computer), requiring additional control components and wiring within the air spring. This complex structure increases the space required for the air spring installation, making assembly more complex and costly, while also increasing vehicle energy consumption. Furthermore, existing multi-chamber independent air springs offer only four levels of stiffness adjustment, with limited adjustment modes, making it impossible to achieve a wide range of stepless adjustment and preventing precise adjustment of the air spring's stiffness curve according to actual needs. Utility Model Content

[0004] The technical problem to be solved by the present invention is: to provide an independent air spring with adjustable stiffness. How to design a structure that can perform stepless adjustment of the volume and stiffness of the air spring over a wide range in a low-cost, simple, fast and effective manner is an urgent problem to be solved in the current field of air spring technology.

[0005] The technical solution adopted by the utility model to solve the technical problem is: an independent air spring with adjustable stiffness, comprising a base, an airbag and a piston, wherein the lower end of the airbag is fastened to the outer wall of the base, and the upper end of the airbag is fastened to the outer wall of the piston; a protective tube is provided on the outer wall of the airbag;

[0006] The piston is provided with an axially penetrating stepped hole, wherein the large hole of the stepped hole and the small hole of the stepped hole are coaxially arranged vertically; an axial adjustment seat is provided in the large hole, and the side wall of the axial adjustment seat is threadedly connected to the hole wall of the large hole; a sealing plug is provided in the small hole and moves axially with the axial adjustment seat, and the sealing plug is in sealing cooperation with the small hole;

[0007] The base, the airbag, the piston and the sealing plug form a closed air chamber.

[0008] Furthermore, a lower limit portion is provided at the lower end of the small hole.

[0009] Furthermore, the upper end of the axial adjustment seat is located in the large hole; and a hexagonal groove is provided on the upper end surface of the axial adjustment seat.

[0010] Furthermore, the outer side surface of the sealing plug is provided with an annular groove arranged coaxially therewith, and there are at least two annular grooves, and at least two of the annular grooves are distributed along its axial direction; a sealing ring is provided in the annular groove, and the sealing plug is sealed and connected to the hole wall of the small hole through the sealing ring.

[0011] Furthermore, a push rod is provided on the axial adjustment seat, the lower end of the push rod is located in the small hole, and the lower end surface of the push rod is axially abutted against the sealing plug.

[0012] Furthermore, the push rod is coaxially arranged with the axial adjustment seat, and the cross section of the push rod is a circular structure.

[0013] Furthermore, an annular space is provided between the push rod and the wall of the small hole.

[0014] Furthermore, the lower end of the push rod is rotatably connected to an abutment member arranged coaxially therewith; the lower end of the abutment member protrudes from the lower end surface of the push rod and abuts axially with the sealing plug; an upper limit portion is provided on the push rod, and the upper limit portion abuts against the upper end surface of the abutment member.

[0015] Furthermore, the abutment member is a thrust ball bearing, and the push rod is interference fit with the inner hole of the thrust ball bearing.

[0016] Furthermore, the push rod includes an upper shaft section and a lower shaft section arranged adjacent to each other in the upper and lower directions, the outer diameter of the upper shaft section is larger than the outer diameter of the lower shaft section; the upper limit portion is a shaft shoulder between the upper shaft section and the lower shaft section.

[0017] Compared with the prior art, the beneficial effects of the present invention are: providing an independent air spring with adjustable stiffness, which seals the air chamber of the air spring by arranging a stepped through hole on the piston and installing a sealing plug in its small hole, and the sealing plug can be installed and removed through the large hole, which is convenient for replacing and maintaining the sealing plug; the volume of the air chamber of the air spring is adjusted by installing an axial adjustment seat through the thread in the large hole of the stepped through hole to drive the sealing plug to move axially synchronously, thereby realizing stepless adjustment of the stiffness of the air spring, simple structure and low cost. Compared with the existing multi-chamber independent air spring, the present invention has a large adjustable stiffness range and high adjustment accuracy, and can adjust the air spring to a specified stiffness as needed according to different driving scenarios and the driver's personal preferences, and has strong adaptability. By arranging a push rod axially abutting the sealing plug on the axial adjustment seat, rotational wear between the side wall of the sealing plug and the wall of the small hole can be avoided; by arranging an abutment piece rotatably connected to the lower end of the push rod to press the sealing plug tightly, the push rod and the sealing plug are arranged at intervals, thereby avoiding mutual wear between the push rod and the sealing plug during stiffness adjustment, improving the stiffness adjustment accuracy of the air spring, and extending the service life of the push rod and the sealing plug; by arranging the abutment piece as a thrust ball bearing with an interference fit with the push rod, the manufacturing cost of the abutment piece is saved and the service life of the abutment piece is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the axial cross-sectional structure of the utility model;

[0019] Figure 2 yes Figure 1 A schematic diagram of the enlarged structure of the middle part A;

[0020] Figure markings: 1-base; 2-airbag; 21-protective cylinder; 3-piston; 31-large hole; 32-small hole; 33-lower limit part; 4-air chamber; 5-axial adjustment seat; 51-hexagonal groove; 52-push rod; 53-abutment member; 54-upper limit part; 6-sealing plug; 61-sealing ring. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] As attached Figure 1-2As shown, a stand-alone air spring with adjustable stiffness comprises a base 1, an airbag 2, and a piston 3. The lower end of the airbag 2 is fastened to the outer wall of the base 1, and the upper end of the airbag 2 is fastened to the outer wall of the piston 3. A protective sleeve 21 is provided on the outer wall of the airbag 2. The piston 3 has an axially extending stepped hole, with a large hole 31 and a small hole 32 of the stepped hole arranged coaxially in the vertical direction. An axial adjustment seat 5 is provided in the large hole 31, and the side wall of the axial adjustment seat 5 is threadedly connected to the hole wall of the large hole 31. A sealing plug 6 is provided in the small hole 32, which moves axially with the axial adjustment seat 5 and seals with the small hole 32. The base 1, the airbag 2, the piston 3, and the sealing plug 6 enclose a sealed air chamber 4. The axis of the piston 3 is arranged in the vertical direction.

[0023] When the axial adjustment seat 5 is screwed in downward, the axial adjustment seat 5 drives the sealing plug 6 to press down and move to compress the volume of the air chamber 4 of the air spring, thereby increasing the stiffness of the air spring; conversely, when the axial adjustment seat 5 is screwed out upward, the axial adjustment seat 5 drives the sealing plug 6 to move upward to increase the volume of the air chamber 4 of the air spring, thereby reducing the stiffness of the air spring. In summary, the utility model adjusts the volume of the air chamber 4 of the air spring by rotating the axial adjustment seat 5 to drive the sealing plug 6 to move axially synchronously, thereby achieving stepless adjustment of the stiffness of the air spring, with a simple structure and low cost. Compared with the existing multi-chamber independent air spring, the utility model has a large adjustable stiffness range and high adjustment accuracy. The air spring can be adjusted to a specified stiffness as needed according to different driving scenarios and the driver's personal preferences, and has strong adaptability. In addition, the sealing plug 6 of the utility model can be installed into the small hole 32 through the large hole 31 or removed through the large hole 31, which is convenient for replacing and maintaining the sealing plug 6.

[0024] The large hole 31 is used to accommodate and install the axial adjustment seat 51, and provides a maintenance channel for the assembly and disassembly of the piston 6, which facilitates the assembly and disassembly of the sealing plug 6. The small hole 32 is used to install the sealing plug 6. In order to ensure that the sealing plug 6 slides smoothly, the hole wall of the small hole 332 should be smooth enough. Preferably, a lower limit portion 33 is provided at the lower end of the small hole 32 to limit the axial position of the sealing plug 6 to prevent the sealing plug 6 from falling out of the lower end of the small hole 32 during downward movement, causing air spring leakage. The lower limit portion 33 has a variety of structural forms, which can be a single or multiple raised structures arranged on the side wall of the small hole 32, or an inner convex ring plate arranged on the end face of the piston 3 or on the side wall of the small hole 32. The lower end of the small hole 32 refers to the end away from the large hole 31.

[0025] The axial adjustment seat 51 is threadedly connected to the wall of the large hole 31, allowing for adjustable axial position, thereby driving the axial movement and positioning of the sealing plug 6. The upper end of the axial adjustment seat 51 can protrude from the stepped hole or reside within it. Preferably, the upper end of the axial adjustment seat 51 resides within the large hole 31, reducing the volume of the air spring, saving installation space, and facilitating the arrangement and installation of other vehicle suspension components. A convex structure can be provided on the axial adjustment seat 51, allowing it to be clamped and rotated using a spanner. Alternatively, a groove can be provided on the axial adjustment seat 51, allowing it to be rotated using a screwdriver or Allen wrench of a shape and size that matches the groove. When the upper end surface of the axial adjustment seat 51 is within the large hole 31, it is difficult to clamp and rotate. Preferably, a hexagonal groove 51 is provided on the upper end surface of the axial adjustment seat 5, allowing it to be screwed in or out using a compact and commonly available Allen wrench, facilitating commissioning.

[0026] The sealing plug 6 is used to block the small hole 32 on the piston 3. It seals with the small hole 32 and seals the air chamber 4 of the air spring. The sealing plug 6 also slides axially with the wall of the small hole 32 to make the volume of the air chamber 4 adjustable. The sealing plug 6 has various structural forms, such as an integral structure made of rubber, a combined structure consisting of a rigid skeleton and a rubber jacket, etc. Specifically, the outer side of the sealing plug 6 is provided with a coaxial annular groove, and a sealing ring 61 is provided in the annular groove. The sealing plug 6 is sealed and connected to the wall of the small hole 32 through the sealing ring 61 to ensure the sealing of the air spring. The above-mentioned annular groove can be provided in one or more ways. Specifically, the annular groove is provided with at least two, and the at least two annular grooves are distributed along the axial direction to further ensure the sealing of the air chamber 4 of the air spring.

[0027] The axial adjustment seat 5 and the sealing plug 6 can be an integrally formed unitary structure or a combined structure fixedly connected via an adapter. However, in this structure, when the axial adjustment seat 5 rotates, it drives the sealing plug 6 to rotate synchronously, causing the sealing plug 6 to rub against the wall of the small hole 32, accelerating the wear of the side wall of the sealing plug 6 and shortening the service life of the sealing plug 6. Preferably, the axial adjustment seat 5 is provided with a push rod 52, the lower end of which is located within the small hole 32, and the lower end surface of the push rod 52 axially abuts the sealing plug 6. When the axial adjustment seat 5 is rotated in a direction toward the sealing plug 6, it drives the push rod 52 to rotate synchronously, and the push rod 52 pushes the sealing plug 6 downward during the rotational movement. When the axial adjustment seat 5 is rotated outward toward the sealing plug 6, it drives the push rod 52 to rotate out synchronously and disengage the push rod 52 from the sealing plug 6. At the moment when the sealing plug 6 loses the support of the push rod 52, the compressed gas in the air chamber 4 of the air spring pushes the sealing plug 6 outward until the push rod 52 abuts the sealing plug 6 again. During this process, the sealing plug 6 only performs axial reciprocating motion, thereby avoiding rotational friction between the sealing plug 6 and the wall of the small hole 32 , delaying the wear of the sealing plug 6 and extending the service life of the sealing plug 6 .

[0028] The cross-section of the push rod 52 can be annular, circular, square, or other polygonal structures. For ease of processing, the push rod 52 is preferably coaxially arranged with the axial adjustment seat 5, and the cross-section of the push rod 52 is a circular structure. The outer wall of the push rod 52 can slide with the wall of the small hole 32, or it can be spaced therefrom. Preferably, an annular space is provided between the push rod 52 and the wall of the small hole 32 to prevent resistance generated by sliding friction between the push rod 5 and the wall of the small hole 32 when the axial adjustment seat 5 rotates, thereby reducing the driving force required to rotate the axial adjustment seat 5 in or out, and reducing the intensity of the debugging operation.

[0029] When the axial adjustment seat 5 drives the push rod 52 to rotate synchronously, the lower end surface of the push rod 52 will rub against the sealing plug 6, causing wear on both, affecting the air spring's calibration accuracy and even damaging the sealing plug 6. Preferably, the lower end of the push rod 52 is rotatably connected to an abutment member 53 coaxially arranged therewith. The lower end of the abutment member 53 protrudes from the lower end surface of the push rod 52 to axially abut the sealing plug 6. The push rod 52 is provided with an upper limit portion 54, which abuts the upper end surface of the abutment member 53. The lower end of the push rod 52 refers to the end closest to the sealing plug 6. When the axial adjustment seat 5 drives the push rod 52 to rotate, the push rod 52 presses against the sealing plug 6 through the abutment 53. The rotational static friction between the sealing plug 6 and the wall of the small hole 32 and the static friction between the abutment 53 and the sealing plug 6 are both greater than the rotational friction between the abutment 53 and the push rod 52. The push rod 52 rotates relative to the abutment 53 while pushing the abutment 53 and the sealing plug 6 for compression movement. The abutment 53 and the sealing plug 6 are fixedly abutted and the two will not move relative to each other, thereby avoiding mutual wear between the push rod 52 and the sealing plug 6, extending their service life, and ensuring the adjustment accuracy of the air spring stiffness.

[0030] The abutment 53 can be a structure such as a rotating shaft or a sleeve, which can be directly connected to the push rod 52 for rotation, or it can be connected to the push rod 52 for rotation through a rolling bearing. Preferably, the abutment 53 is a rolling bearing, and the push rod 52 has an interference fit with the inner hole of the rolling bearing. This prevents the rolling bearing from falling off and improves the stability of the air spring. In addition, rolling bearings are easy to purchase and have high precision, making them easy to install and saving costs. Considering that the abutment 53 mainly bears axial force during the operation of the air spring, as a further preference, the abutment 53 is a thrust ball bearing to extend the service life of the abutment 53.

[0031] The upper limit portion 54 is used to limit the axial position of the abutment member 53 on the push rod 52. It can be a latch inserted into the side of the push rod 52, or a stopper or ring plate structure protruding from the side of the push rod 52. Preferably, the push rod 52 includes an upper shaft section and a lower shaft section arranged adjacent to each other, with the outer diameter of the upper shaft section being larger than that of the lower shaft section. The upper limit portion 54 is a shoulder between the upper and lower shaft sections. The upper limit portion 54 is integrally formed with the push rod for ease of manufacturing.

[0032] The terms "upper," "lower," "top," and "bottom" in this utility model are relative positions and should not be construed as limiting specific positions. The embodiments of this specific implementation are preferred embodiments of the utility model and are not intended to limit the scope of protection of the utility model. Therefore, any equivalent changes based on the structure, shape, and principle of the utility model are intended to be within the scope of protection of the utility model.

Claims

1. An independent air spring with adjustable stiffness, comprising a base (1), an airbag (2) and a piston (3), wherein the lower end of the airbag (2) is fastened to the outer wall of the base (1), and the upper end of the airbag (2) is fastened to the outer wall of the piston (3); a protective sleeve (21) is provided on the outer wall of the airbag (2); and the characteristics are: The piston (3) has an axially through-going stepped hole, wherein the large hole (31) of the stepped hole and the small hole (32) of the stepped hole are coaxially arranged in the upper and lower directions; an axial adjustment seat (5) is provided in the large hole (31), and the side wall of the axial adjustment seat (5) is threadedly connected to the hole wall of the large hole (31); a sealing plug (6) is provided in the small hole (32) and moves axially with the axial adjustment seat (5), and the sealing plug (6) is in sealing cooperation with the small hole (32); The base (1), the air bag (2), the piston (3) and the sealing plug (6) form a closed air chamber (4).

2. The independent air spring with adjustable stiffness according to claim 1, characterized in that: A lower limit portion (33) is provided at the lower end of the small hole (32).

3. The independent air spring with adjustable stiffness according to claim 1, characterized in that: The upper end of the axial adjustment seat (5) is located in the large hole (31); and the upper end surface of the axial adjustment seat (5) is provided with a hexagonal groove (51).

4. The independent air spring with adjustable stiffness according to claim 1, characterized in that: The outer side surface of the sealing plug (6) is provided with an annular groove arranged coaxially therewith, and at least two annular grooves are provided, and at least two annular grooves are distributed along its axial direction; a sealing ring (61) is provided in the annular groove, and the sealing plug (6) is sealedly connected to the hole wall of the small hole (32) through the sealing ring (61).

5. The independent air spring with adjustable stiffness according to any one of claims 1 to 4, characterized in that: A push rod (52) is provided on the axial adjustment seat (5), the lower end of the push rod (52) is located in the small hole (32), and the lower end surface of the push rod (52) is in axial contact with the sealing plug (6).

6. The independent air spring with adjustable stiffness according to claim 5, characterized in that: The push rod (52) is coaxially arranged with the axial adjustment seat (5), and the cross section of the push rod (52) is a circular structure.

7. The independent air spring with adjustable stiffness according to claim 5, characterized in that: An annular space is provided between the push rod (52) and the wall of the small hole (32).

8. The independent air spring with adjustable stiffness according to claim 7, characterized in that: The lower end of the push rod (52) is rotatably connected to an abutment member (53) arranged coaxially therewith; the lower end of the abutment member (53) protrudes from the lower end surface of the push rod (52) and abuts axially with the sealing plug (6); an upper limit portion (54) is provided on the push rod (52), and the upper limit portion (54) abuts against the upper end surface of the abutment member (53).

9. The independent air spring with adjustable stiffness according to claim 8, characterized in that: The abutment member (53) is a thrust ball bearing, and the push rod (52) is interference-fitted with the inner hole of the thrust ball bearing.

10. The independent air spring with adjustable stiffness according to claim 8, characterized in that: The push rod (52) comprises an upper shaft section and a lower shaft section arranged adjacent to each other in the upper and lower directions, wherein the outer diameter of the upper shaft section is larger than the outer diameter of the lower shaft section; and the upper limit portion (54) is a shaft shoulder between the upper shaft section and the lower shaft section.

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