RU230304U1 - Self-adjusting shock absorber - Google Patents

Abstract

The utility model relates to shock absorbers for vehicle suspensions. The technical result is achieved in a self-adjusting shock absorber comprising a cylinder, a compensation chamber located in the lower part of the cylinder, a rod with a piston installed in the cylinder, dividing the cylinder into above-piston and below-piston cavities, communicating with each other through a main throttle installed in a through coaxial bore of the piston, an additional throttle installed in a blind coaxial bore of the piston communicating with the above-piston cavity, a two-stage spring-loaded plunger installed in an axial bore of the piston, compression and rebound stroke safety valves, a blind axial bore in the rod forming an above-plunger cavity, an annular plunger cavity communicating with the through coaxial bore through and blind coaxial holes and with the below-plunger cavity through a filter, holes in a larger stage plunger, plunger check valve and longitudinal throttle groove made on the larger plunger stage. The technical result is an increase in the smoothness of the ride when driving on almost any type of road.

Description

The utility model relates to devices for damping vibrations of vibration-isolated objects and is intended for use primarily in vehicle suspensions together with elastic load-bearing elements.

A single-tube gas-filled shock absorber is known, comprising a cylinder, a rod with a piston, throttle holes made in the piston and compression and rebound stroke unloading valves installed in it, a hydraulic cavity of the cylinder filled with working fluid and divided by a piston into above-piston and below-piston cavities, a compensation chamber, a floating piston separating the compensation chamber and the hydraulic cavity of the cylinder [Raimpel J. Automobile chassis. Shock absorbers, tires, and wheels. - M.: Mashinostroenie, 1986, p. 34, Fig. 1.33].

The disadvantage of this shock absorber is that it allows for the implementation of a single damping characteristic determined by the area of the throttle holes, the area of the piston and rod, the viscosity of the working fluid, as well as the parameters of the unloading valves of the compression and rebound strokes. This method of damping does not allow for the achievement of acceptable levels of vehicle vibration when driving on various roads.

A device is known for regulating the resistance of a vehicle suspension shock absorber, which includes a cylinder in which a piston with a rod is placed, forming sub-piston and above-piston cavities with the cylinder, connected to each other through a valve, automatically regulated depending on the vibration modes with the help of a hydraulic pressure relay, a time relay and an actuator placed in the piston. The pressure relay is made in the form of a spring-loaded ball pressed by a plug with a hole connecting the above-piston cavity of the cylinder with the internal cavity of the rod, and the time relay and the actuator are made in the form of a hollow stepped piston connected to a valve interacting with the outer surface of a spring-loaded cup resting with its bottom on the flange of a nut screwed onto the end of the rod, covered by the cylindrical wall of the return valve plate and equipped with an annular rib with holes, wherein the internal cavity of the piston is connected by channels and a valve located in it with the chambers of the shock absorber, and holes are made in the walls of the nut and cup. This device provides a soft damping characteristic with small vibrations. In the case of oscillations causing pressure differences exceeding the force of the pressure relay spring, fluid is supplied during the rebound stroke from the above-piston cavity to the internal cavity of the piston and the hollow stepped piston and the valve blocking the cup openings are moved, which increases the rigidity of the damping characteristic, which is maintained for some time after the pressure difference decreases due to throttling of the fluid from the internal cavity of the piston to the above-piston cavity. As a result, this device ensures effective damping of oscillations at high relative deformation rates of the device [USSR patent No. 239809, IPC B60G17/04, 1972].

The disadvantage of this device is the ineffective operation of the shock absorber design, since in the resonant zone of vehicle oscillations, conditions arise for the operation of the pressure relay due to high relative speeds. This leads to an increase in hydraulic resistance, as a result of which the smoothness of the ride deteriorates and the thermal stress of the device increases.

The closest to the proposed technical solution is a self-adjusting shock absorber containing a cylinder, a compensation chamber located in the lower part of the cylinder, a rod with a piston installed in the cylinder dividing the cylinder into above-piston and below-piston cavities, communicated with each other through a main throttle hole and additional throttle holes made in the piston, as well as through a spring-loaded plunger and compression and rebound stroke safety valves installed in the piston. At high rebound speeds, under the action of a pressure difference, the spring-loaded plunger shifts downwards and closes the additional throttle holes, increasing resistance on the compression and rebound strokes [Derbaremdiker A.D. Shock Absorbers of Transport Machines. - 2nd ed., revised and enlarged. Moscow: Mashinostroenie, 1985. - 200 pp., pp. 39-40, Fig. 32a].

The disadvantage of this shock absorber is that its resistance depends only on the pressure difference during the rebound stroke and does not depend on the amplitude of the suspension oscillations. As a result, at low amplitudes and high frequencies of the suspension operation, which occurs when the car is moving on a relatively flat road with frequently located low-height unevenness, there will be an increase in the forces and accelerations transmitted from the wheels to the body, which will lead to a decrease in ride smoothness and an increase in energy losses in the suspension. In addition, with an open additional throttle hole and a high compression speed, which occurs when the car is moving on smooth asphalt and hitting a sharply protruding unevenness, the shock absorber creates a small resistance force, which can lead to a strong breakdown of the suspension, its breakage and a decrease in traffic safety.

In this regard, the most important task is to create a new design of a self-regulating shock absorber that ensures self-regulation of its resistance during compression and rebound strokes depending on the amplitude of vibrations.

The technical result of the declared technical solution is an increase in the smoothness of the ride and reliability of the suspension when driving on almost any type of road.

The technical result is achieved in a self-adjusting shock absorber comprising a cylinder, a compensation chamber located in the lower part of the cylinder, a rod with a piston installed in the cylinder, dividing the cylinder into above-piston and below-piston cavities, communicating with each other through a main throttle installed in the piston, an additional throttle, a spring-loaded plunger installed in the axial bore of the piston, and compression and rebound stroke safety valves, wherein the spring-loaded plunger is made two-stage, a blind axial hole is made in the rod, communicating with the axial bore of the piston, forming an above-plunger cavity, the main throttle is installed in a through coaxial hole made in the piston, communicating the above-piston and below-piston cavities, the additional throttle is installed in a blind coaxial hole made in the piston, communicating with the above-piston cavity, an annular plunger cavity, communicated with a through coaxial hole through an upper radial channel located below the main throttle, communicated with the through and blind coaxial holes through a lower radial channel located below the main and additional throttles, and communicated with the sub-plunger cavity through a filter, holes in the larger plunger stage, a plunger check valve and a longitudinal throttle groove made on the larger plunger stage.

Due to the fact that a blind axial hole is made in the rod, forming a rod cavity, an axial hole is made in the piston, communicating with the rod cavity, a through coaxial hole communicating the above-piston and below-piston cavities with each other, and a blind coaxial hole communicating with the above-piston cavity, a main throttle is installed in the through coaxial hole, an additional throttle is installed in the blind coaxial hole, and a spring-loaded stepped plunger is installed in the axial hole, forming with the piston an above-plunger cavity communicated with the rod cavity, a below-plunger cavity and an annular plunger cavity communicated with the through coaxial hole through the upper radial channel located below the main throttle, communicated with the through and blind coaxial holes through the lower radial channel located below the main and additional throttles, and communicated with the sub-plunger cavity through a filter, holes in the larger plunger stage, a plunger check valve and a longitudinal throttle groove made on the larger plunger stage, self-regulation of the inelastic resistance of the shock absorber is ensured depending on the amplitude of the oscillations, which increases the smoothness of the ride and the safety of the vehicle, and also reduces energy losses in the suspension when driving on almost any type of road.

Fig. 1 shows a general view of the shock absorber, and Fig. 2 shows a damping unit that self-regulates resistance depending on the amplitude of vibrations.

The shock absorber comprises a cylinder 1, a rod 2 installed in it with a piston 3 dividing the cylinder 1 into an above-piston 4 and below-piston 5 cavity filled with liquid (Fig. 1). In the rod 2 there is a blind axial hole 6 forming a rod cavity 7. In the piston 3 there is an axial hole 8 communicating with the rod cavity 7, a through coaxial hole 9 communicating the above-piston 4 and below-piston 5 cavities with each other, and a blind coaxial hole 10 communicating with the above-piston cavity 4.

In the through coaxial hole 9, the main throttle 11 is installed, in the blind coaxial hole 10, the additional throttle 12 is installed, and in the axial hole 8, a spring-loaded stepped plunger 13 is installed, forming with the piston 3 an above-plunger cavity 14, a sub-plunger cavity 15 and an annular plunger cavity 16. The above-plunger cavity 14 is in communication with the rod cavity 7. The annular plunger cavity 16 is in communication with the through coaxial hole 9 through the upper radial channel 17, located below the main throttle 11, is in communication with the through and blind coaxial holes 9 and 10 through the lower radial channel 18, located below the main 11 and additional 12 throttles, and is in communication with sub-plunger cavity 15 through filter 19, openings 20 in the larger stage of plunger 13, check valve 21 of plunger 13 and longitudinal throttle groove 22, made on the larger stage of plunger 13. In the annular plunger cavity 16, spring 23 of stepped plunger 13 is installed, which, when moving upward with its larger stage, closes lower radial channel 18, ensuring the closing of additional throttle 12 and an increase in inelastic resistance at large shock absorber strokes (Fig. 2).

For reliable sealing of the above-plunger cavity 14, in which air is under atmospheric pressure, a sealing ring 24 is installed on the smaller stage of the plunger 13. To limit the force of the shock absorber, compression stroke 25 and rebound stroke 26 safety valves are installed in the piston 3.

In the lower part of the cylinder 1 there is a compensating pneumatic chamber 27, which is separated from the hydraulic sub-piston cavity 5 by a floating piston 28.

The shock absorber works as follows.

When the suspension oscillates with small amplitudes, the pressure in the compensating pneumatic chamber 27 changes insignificantly. Therefore, the spring-loaded stepped plunger 13, installed in the axial opening 8 of the piston 3, is in the extreme lower position under the action of the spring 23 and its large step does not block the lower radial channel 18. As a result, on the compression and rebound strokes, the above-piston 4 and sub-piston 5 cavities communicate through the through coaxial opening 9, in which the main throttle 11 is installed, as well as through the lower radial channel 18 and the blind coaxial opening 10, in which the additional throttle 12 is installed, which provides a small resistance of the shock absorber on the compression and rebound strokes.

With an increase in suspension vibrations, the strokes of rod 2 with piston 3 and floating piston 28 in cylinder 1 increase, which increases the change in pressure in compensating pneumatic chamber 27 and sub-piston cavity 5. When the static pressure in compensating chamber 27 and sub-piston cavity 5 is exceeded during the compression stroke by more than 1.5 times, stepped plunger 13 moves upward, compressing spring 23, and with its larger step closes lower radial channel 18, ensuring the closing of additional throttle 12 and an increase in the inelastic resistance of the shock absorber. When the plunger 13 moves upward, the liquid from the annular plunger cavity 16, communicated with the through coaxial opening 9 through the upper radial channel 17, enters the sub-plunger cavity 15 through the filter 19, the oblique openings 20 in the larger stage of the plunger 13 and the spring-loaded check valve 21 installed in the larger stage of the plunger 13. In this case, the air pressure in the above-plunger cavity 14 practically does not change, since it communicates with the rod cavity 7, which has a large volume.

At high speeds, the compression stroke safety valves 25 and rebound stroke safety valves 26 are activated, limiting the force of the shock absorber.

When the suspension vibrations decrease, the maximum pressure in the compensation chamber 27 decreases, the check valve 21 closes and the stepped plunger 13, under the action of the spring 23, slowly moves downwards, gradually opening the lower radial channel 18 and squeezing the liquid from the sub-plunger cavity 15 into the annular plunger cavity 16 through the longitudinal throttle groove 22. When the stepped plunger 13 is completely lowered, the lower radial channel 18 opens and the resistance of the shock absorber weakens. When the plunger 13, the smaller step of which has a sealing ring 24, moves up and down, the air pressure in the rod cavity 7, formed by the blind hole 6 in the rod 2, practically does not change.

The proposed self-adjusting shock absorber provides increased smoothness and safety of vehicle movement, as well as reduced energy losses in the suspension. The use of this shock absorber will lead to a decrease in the vibration load of the vehicle and operating costs, a decrease in the total energy losses caused by vibrations, an increase in the average speeds and productivity of wheeled and tracked vehicles when moving on almost any type of road.

Claims (1)

A self-adjusting shock absorber comprising a cylinder, a compensation chamber located in the lower part of the cylinder, a rod installed in the cylinder with a piston dividing the cylinder into above-piston and below-piston cavities, communicating with each other through a main throttle installed in the piston, an additional throttle, a spring-loaded plunger installed in an axial bore of the piston, and compression and rebound stroke safety valves, characterized in that the spring-loaded plunger is made two-stage, a blind axial bore is made in the rod, communicating with the axial bore of the piston, forming an above-plunger cavity, the main throttle is installed in a through coaxial bore made in the piston, communicating the above-piston and below-piston cavities, the additional throttle is installed in a blind coaxial bore made in the piston, communicating with the above-piston cavity, an annular the plunger cavity communicates with the through coaxial hole through the upper radial channel located below the main throttle, communicates with the through and blind coaxial holes through the lower radial channel located below the main and additional throttles, and communicates with the sub-plunger cavity through a filter, holes in the larger plunger stage, a plunger check valve and a longitudinal throttle groove made on the larger plunger stage.