Shock absorber

Abstract

This invention relates to devices that protect vehicles from oscillations, vibrations, and shocks, namely to shock absorbers. The shock absorber comprises: a housing (1) filled with hydraulic oil; a hollow rod (3) that is movable and seal-mounted in the housing (1) and protrudes from it; a piston (2) attached to the end portion of the hollow rod (3) inside the housing (1); a pneumatic cylinder (5) connected to the hollow rod (3); a reserve chamber (7) connected to the pneumatic cylinder (5); the piston (2) is configured as a toroid with a polygonal cross-section, having its frontal portion as an edge, the diameter of which is equal to the outer diameter of the hollow rod (3); the housing (1) is configured in such a way that its inner diameter increases gradually from the ends to its middle part, forming a variable annular gap between the piston (2) and the housing (1), which ensures the throttling of the hydraulic oil. The shock absorber has the following advantages: damping force control, position-sensitive damping and self-damping air spring.

Description

[0001] Description

[0002] Shock Absorber

[0003] This invention relates to mechanical engineering and concerns devices that protect vehicles from oscillations, vibrations, and shocks, namely shock absorbers. Vehicle shock absorbers have the disadvantage that their damping action is not coordinated with the vehicles' sprung mass and their support springs' stiffness at different oscillation amplitude points, which leads to excessive oscillations, vibrations, and shocks.

[0004] The prototype of this invention is an invention for which a patent US4405119A was issued on September 20, 1983, in which a hydropneumatic shock absorber contains a hollow rod with a pneumatic spring formed in it at the end of its attachment, a piston at the end of the hollow rod that is installed in a cylinder where the piston slides and is threaded on a guide rod fixed to the bottom of the cylinder in the center, two throttle valves, configured in the piston, and throttling grooves in the lower parts of the cylinder and guide rod. The disadvantage of this hydropneumatic shock absorber is that its damping force is not gradually variable and controllable.

[0005] The present invention aims to reduce vehicle oscillations, vibrations, and shocks, and to control the damping force.

[0006] As shown in Figure 1, the shock absorber comprises a housing (1), a piston (2), a hollow rod (3), a pneumatic cylinder (5), and a reserve chamber (7). The piston (2) is attached to the end portion of the hollow rod (3) inside the housing (1). The hollow rod (3) is connected to the pneumatic cylinder (5) through a two-way hydraulic throttle valve (4) and the pneumatic cylinder (5) is connected to the reserve chamber (7) through a two-way pneumatic throttle valve (6). The housing (1) and the hollow rod (3) are filled with hydraulic oil, which flows through the piston (2). The pneumatic cylinder (5) is also filled with hydraulic oil, which flows through the twoway hydraulic throttle valve (4). The hydraulic oil in the pneumatic cylinder (5) is separated from the air by a separating piston (8). The reserve chamber (7) is filled with air through a valve (9), which also sets and controls pressure in it. The housing (1) has a bottom with a mounting bracket for unsprung vehicle mass. The hollow rod (3) is movably seal-mounted in the housing (1), protrudes from it, and ends with a mounting bracket for the vehicle's sprung mass. The inner diameter of the housing (1) gradually increases from its ends to its middle portion, forming a variable annular gap between the piston (2) and the housing (1) that enables hydraulic oil throttling. The piston (2) is configured as a toroid with a polygonal cross-section, having its frontal portion as an edge, the diameter of which is equal to the outer diameter of the hollow rod (3). The piston (2), with its frontal edge, conditionally divides the hydraulic oil into two portions: one that communicates with the hydraulic oil between the hollow rod (3) and the housing (1) through the variable annular gap, and another that communicates with the hydraulic oil inside the hollow rod (3) through the piston (2). A pneumatic spring is formed in the enclosure between the separating piston (8) and the two-way pneumatic throttle valve (6), with its stiffness set and controlled by the two-way pneumatic throttle valve (6) and the valve (9). The piston (2) has conical surfaces on its frontal and rear sides that, together with the gradually tapered shape of the housing (1), reduce the turbulence of the hydraulic oil flows during oscillation, ensuring the coaxial alignment of the hollow rod (3) with the housing (1). The shock absorber operates as follows: During the compression phase, the hollow rod (3) with the piston (2) moves deeper into the housing (1). The hydraulic oil flows through the variable annular gap between the piston (2) and the housing (1), which gradually increases, facilitating the oil flow and thus gradually reducing the damping force caused by the hydraulic oil throttling through this variable annular gap. This damping force reaches a minimum value when the piston (2) passes through the middle portion of the housing (1), and increases to a maximum value as the piston (2) approaches the bottom of the housing (1), where it stops smoothly. Simultaneously, the hydraulic oil flows from the housing (1) into the hollow rod (3) through the piston (2) and then into the pneumatic cylinder (5) through the two-way hydraulic throttle valve (4), moving the separating piston (8). This movement pushes air from the pneumatic cylinder (5) into the reserve chamber (7) through the two-way pneumatic throttle valve (6). The hydraulic oil throttling through the two-way hydraulic throttle valve (4) causes a damping force controlled by the two-way hydraulic throttle valve (4). Additionally, the damping force caused by the air throttling through the two-way pneumatic throttle valve (6) is controlled by the two-way pneumatic throttle valve (6). The air pressure of the pneumatic spring in the enclosure between the separating piston (8) and the two-way pneumatic throttle valve (6) increases to its maximum at the end position of the piston (2) near the bottom of the housing (1). Due to the airflow from the pneumatic cylinder (5) to the reserve chamber (7), the air pressure in the pneumatic cylinder (5) increases more slowly than it would without the connection to the reserve chamber (7). Thus, the pneumatic spring, formed in the enclosure between the separating piston (8) and the two-way pneumatic throttle valve (6), acts as a selfdamping spring. The air pressure in the reserve chamber (7) also increases, but due to the air throttling through the two-way pneumatic throttle valve

[0007] (6), it remains lower than the air pressure in the pneumatic cylinder (5). During the rebound phase, the hollow rod (3) with the piston (2) moves from the down position, compressing the hydraulic oil between the hollow rod (3) and the housing (1). The hydraulic oil flows through the variable annular gap between the piston (2) and the housing (1), being throttled. This causes a damping force that gradually decreases to the middle position of the piston (2) and then increases to its uppermost position, where the piston (2) stops smoothly. Simultaneously, the hydraulic oil flows from the pneumatic cylinder (5) back to the hollow rod (3), being throttled by the two- way hydraulic throttle valve (4) due to the stretching of the hollow rod (3) and the resulting volume increase within the housing (1) and hollow rod (3). The damping force caused by the throttling through the two-way hydraulic throttle valve (4) is controlled by the two-way hydraulic throttle valve (4). At the same time, the air pressure of the pneumatic spring in the pneumatic cylinder (5) decreases as the air rarefaction is created in the pneumatic cylinder due to the movement of the separating piston (8) with the hydraulic oil flowing into the hollow rod (3). The airflow from the pneumatic cylinder (5) to the reserve chamber (7) continues after the completion of the compression phase until the pressure in the pneumatic cylinder (5) equals the pressure in the reserve chamber (7). After that, air flows from the reserve chamber (7) to the pneumatic cylinder (5), and the pressure in the reserve chamber (7) begins to decrease. However, it will still be higher than the air pressure in the pneumatic cylinder (5) due to the air throttling through the two-way pneumatic throttle valve (6). The air pressure of the pneumatic spring decreases to its minimum at the piston (2)’s upper position. Thus, the air throttling of the bidirectional airflow causes a damping force controlled by the two-way pneumatic throttle valve (6). The pneumatic spring formed in the enclosure between the separating piston (8) and the two-way pneumatic throttle valve (6) acts as a selfdamping pneumatic spring. The technical effect of the claimed invention is the reduction of oscillations, vibrations, and shocks. This is achieved by controllable damping and positionsensitive damping due to the hydraulic throttling through the variable annular gap, allowing soft damping at the midpoint of the oscillation amplitude and harsh damping at its endpoints. This shock absorber offers the following advantages: control of damping forces, position- sensitive damping, and a self-damping pneumatic spring. All these features ensure riding comfort and safety.

Claims

AMENDED CLAIMS received by the International Bureau on 14 March 2025 (14.03.2025)A shock absorber comprising a housing (1) filled with hydraulic fluid, a hollow rod (3) that is movably seal -mounted in the housing (1) and protrudes from it, a piston (2) attached to the hollow rod (3) inside the housing (1), a pneumatic cylinder (5) connected to the hollow rod (3), a reserve chamber (7) equipped with a valve (9) and connected to the pneumatic cylinder (5), wherein the hollow rod (3) is filled with hydraulic fluid which is connected through the piston (2) to the hydraulic fluid in the housing (1), the pneumatic cylinder (5) is filled with hydraulic fluid which is separated from the air in the pneumatic cylinder (5) by a separating piston (8) and the hydraulic fluid is connected to the hydraulic fluid in the hollow rod (3) through an adjustable hydraulic throttle (4) which enables throttling of the hydraulic fluid to create a damping force, the pneumatic cylinder (5) connected to the reserve chamber (7) through an adjustable pneumatic throttle (6) which enables air throttling to create a damping force.

Images