RU2312029C2 - Vehicle suspension pneumohydraulic spring - Google Patents

Abstract

FIELD: transport engineering.

SUBSTANCE: invention relates to pneumohydraulic springs with self-adjusted hydraulic resistance depending on amplitude and direction of oscillations. Proposed pneumohydraulic spring of vehicle suspension has cylinder with piston and rod forming piston and ring spaces in cylinder, and hydraulic accumulator connected with cylinder space through valve self-adjusted in amplitude and direction of oscillations. Valve is made in form of ring piston installed in cylinder for axial displacement along valve rod. One end of valve rod is connected with support secured on end face of cylinder. Ring piston travel limiter is installed on other end of rod, forming with cylinder a ring space of valve communicating with hydraulic accumulator through holes made in support and forming additional throttling channel and communicating with piston space through main throttling channel made in ring piston and through check valve installed at one of side of ring piston. Blind axial hole is made in piston with rod into which limiter gets at end of spring compression stroke, thus forming inner space of maximum vibration damper communicating with piston space. Invention reduces dynamic loads and increases free travel of spring rod at reduced damping without increasing overall dimensions, provides asymmetrical damping characteristics at compressing and rebound strokes and increased rigidity at end of compression stroke which simplified design, improves reliability and reduces heating of spring, provides smooth running on any road with small irregularities whose probable height does not exceed travel of spring rod corrected to wheel with reduced damping.

EFFECT: reduced dynamic loads, simplified design, improved reliability of vehicle running of roads of any type.

1 dwg

Description

The invention relates to the suspension of vehicles, in particular to pneumohydraulic springs with self-regulating hydraulic resistance, depending on the amplitude and direction of oscillation.

A pneumatic-hydraulic spring of a vehicle is known, comprising a cylinder in which a piston with a rod is mounted, forming a piston and an annular cavity in the cylinder, and a hydraulic accumulator connected to the cylinder cavity through a valve that is self-adjustable in amplitude and direction of oscillation, in which the connecting channel is made and installed with the possibility axial movement of the plunger with a throttle hole forming the main throttle channel with high resistance. The connecting channel has two outgoing openings in the piston cavity of the cylinder and two outgoing openings in the accumulator cavity, forming an additional throttle channel with low resistance, and the plunger in extreme positions during rebound closes one of the outlets in the piston cavity of the cylinder, and during compression compresses one from the outlet holes into the cavity of the accumulator, interacts with one of two pre-preloaded springs installed at the ends of the connecting channel, and opens the a covered hole that communicates the piston cavity of the cylinder with the accumulator cavity at high pressure drops on the compression and rebound passages of the spring (RF patent No. 2226156, B60G 11/26, F16F 5/00, 2004). This spring provides a decrease in hydraulic resistance during fluid flow through an additional throttle channel in the zone of small oscillation amplitudes, regardless of the static position of the piston in the cylinder and has a symmetrical damping characteristic during compression and rebound during fluid flow through the main throttle channel.

The disadvantage of this spring is the high dynamic load on the valve due to the fact that the speed of its plunger significantly exceeds the speed of the piston of the spring due to the very large difference in their areas. The small cross-sectional area of the plunger also limits the stroke of the spring rod with weakened damping, which increases the vibration load of the vehicle and the heating of the spring when driving on a road with a greater height of small irregularities. In addition, the symmetry of the throttle section of the damping characteristic of the spring somewhat reduces the smoothness of the vehicle, and the presence of safety valves restricting the damping force, in the absence of a maximum vibration damper, increase the likelihood of a breakdown of the suspension.

The closest known technical solutions is the pneumatic-hydraulic spring of the vehicle suspension, containing a cylinder in which a piston with a rod is installed, forming a piston and an annular cavity in the cylinder, and a hydraulic accumulator connected to the cylinder cavity through a valve, self-regulating in amplitude and direction of oscillation, in the body of which with the possibility of axial movement, a plunger of a U-shaped section is installed, forming in it a supra-plunger and a sub-plunger cavity, interconnected via a new throttle channel with high resistance, made in the baffle of the plunger, and through a safety valve mounted in the plunger and communicating the sub-plunger and supra-plunger cavities with each other at high pressure drops, and two axial holes are made in the valve body, forming an additional throttle channel with low resistance, one of which connects the plunger cavity with a piston cavity, and the other connects the subplunger cavity with a hydraulic accumulator (RF patent No. 2209735, B60G 11/26, F16F 5/00, 2003). This spring provides a decrease in hydraulic resistance during fluid flow through an additional throttle channel in the zone of small oscillation amplitudes, regardless of the static position of the piston in the cylinder and has a symmetrical damping characteristic during compression and rebound during fluid flow through the main throttle channel.

This spring has a relatively low technical level due to high dynamic loads on the valve, due to the fact that the speed of its plunger exceeds the speed of the spring piston due to the large difference in their areas. The smaller cross-sectional area of the plunger also limits the stroke of the spring rod with weakened damping, which increases the vibration load of the vehicle and the heating of the spring when driving on a road with a greater height of small irregularities. In addition, the symmetry of the throttle section of the damping characteristic of the spring somewhat reduces the smoothness of the vehicle, and the presence of safety valves restricting the damping force, in the absence of a maximum vibration damper, increase the likelihood of a breakdown of the suspension.

In this regard, the most important task is to create a new design of a vehicle’s air-hydraulic spring with a valve that is self-adjustable in amplitude and direction of oscillation, which reduces the dynamic loads acting on it, increases the spring stroke of the spring with weakened damping without increasing the dimensions of the spring, the asymmetry of the damping characteristic during compression and rebound, as well as an increase in its rigidity at the end of the compression stroke.

The technical result of the claimed pneumohydraulic spring of the vehicle suspension is to reduce dynamic loads and increase the free travel of the spring rod with weakened damping without increasing its dimensions, ensuring the asymmetry of the damping characteristic on the compression and rebound moves and increasing its rigidity at the end of the compression stroke, which simplifies the design, increase reliability and reduce heating springs, increase ride comfort when driving a vehicle on any type of road g with frequent minor irregularities, the most likely height does not exceed the above to the wheel stroke rod spring with weak damping.

The specified technical result is achieved in that the pneumohydraulic spring of the vehicle suspension comprises a cylinder in which a piston with a rod is installed, forming a piston and an annular cavity in the cylinder, and a hydraulic accumulator connected to the cylinder cavity through a valve made in the form of an annular self-regulating amplitude and direction of oscillation a piston mounted in the cylinder with the possibility of axial movement along the valve stem, one end of which is connected to a support mounted on the end of the cylinder, and at the other end, an annular piston stroke limiter is installed, forming an annular valve cavity with the cylinder, connected to the hydraulic accumulator through holes made in the support, forming an additional throttle channel, and communicated with the piston cavity through the main throttle channel made in the annular piston, and through a non-return valve, mounted on one side of the annular piston, and in the piston with the rod a blind axial hole is made, into which a limiter enters at the end of the spring compression stroke, forming an internal The maximum vibration damper cavity in communication with the piston cavity.

Due to the fact that in the pneumatic-hydraulic spring of the vehicle suspension the valve is made in the form of an annular piston mounted in the cylinder with the possibility of axial movement along the valve stem, one end of which is fixed, and a stroke limiter of the annular piston forming the annular valve cavity with the cylinder with a hydraulic accumulator and communicated with the piston cavity through the main throttle channel and through the check valve, provides increased reliability and reduced heating p springs, as well as increased ride smoothness when driving on any type of road with frequently encountered small irregularities, the most probable height of which does not exceed the spring stem brought to the wheel of the spring travel with weakened damping.

Due to the fact that the annular piston is installed in the cylinder, the spring is simplified, since it does not require the use of a special housing for the valve, the function of which is performed by the spring cylinder.

Due to the fact that the area of the annular piston is almost equal to the area of the piston, the speed and dynamic loads on the valve are reduced, which increases the reliability of the spring. This increases the stroke of the rod with reduced damping without increasing the axial dimensions of the spring.

Installation of a check valve on one side of the annular piston provides asymmetry in the damping characteristics of the spring, which increases the smoothness of the vehicle.

Due to the fact that a piston with a spring rod has a blind axial bore, into which a limiter enters at the end of the spring compression stroke, forming an internal cavity of the maximum vibration damper in communication with the piston cavity, an increase in the stiffness of the damping characteristic at the end of the spring compression stroke is made, which reduces the likelihood of hard suspension breakdowns.

The analysis of the prior art cited by the applicant, including the search by patents and scientific and technical sources of information, and the identification of sources containing information about analogues of the claimed solution, made it possible to establish that the applicant did not find an analogue characterized by features identical to all the essential features of the claimed invention. The definition from the list of identified analogues of the prototype as the closest solution for the totality of features made it possible to identify the set of essential distinguishing features in relation to the applicant's technical result in the claimed subject matter set forth in the claims. Therefore, the claimed invention meets the requirement of "novelty" under applicable law.

To verify the compliance of the claimed invention with the requirement of "inventive step", the applicant conducted an additional search for known solutions in order to identify features that match the distinctive features of the claimed invention, the results of which show that the claimed invention does not explicitly follow from the prior art. Therefore, the claimed invention meets the requirement of "inventive step".

The drawing shows the proposed air-hydraulic spring suspension of the vehicle, a longitudinal section.

The pneumatic-hydraulic spring of the vehicle suspension comprises a cylinder 1 in which a piston 2 with a rod 3 is mounted, forming a piston 4 and an annular 5 cavity in the cylinder 1, and a hydraulic accumulator 6 mounted in the additional cylinder and connected to the piston cavity 4 via a valve 7 mounted on the left side cylinder 1. A floating piston 8 is installed in the hydraulic accumulator 6, forming a hydraulic 9 and a pneumatic 10 cavity in it. The piston cavity 4 and the hydraulic cavity 9 are filled with liquid, and the pneumatic cavity 10 with gas. The annular cavity 5 may be filled with liquid from the hydraulic system of the machine for lifting the wheel.

The valve 7 is made in the form of a damping unit, self-regulating depending on the amplitude and direction of oscillation. It consists of an annular piston 7 mounted in the cylinder 1 with the possibility of axial movement along the rod 11, one end of which is connected to a support 12 mounted on the left end of the cylinder 1, and a stop 13 is installed at the other end. The annular piston 7 forms an annular with cylinder 1 the cavity 14 of the valve 7, in communication with the hydraulic cavity 9 of the accumulator 6 through the holes 15 in the support 12 and connected to the piston cavity 4 through the main throttle channel 16 in the annular piston 7 and through the check valve 17. The check valve 17 is made in the form e additional holes 18 in the annular piston 7, overlapped during the release of the spring valve plate 17, movably mounted on the left side of the annular piston 7. The stroke of the valve plate 17 is limited by the locking ring 19. In the piston 2 with the rod 3 there is a blind axial hole 20, in which at the end of the compression stroke of the spring, a limiter 13 is included, which forms an internal cavity 21 of the maximum vibration damper in the hole 20, in communication with the piston cavity 4 through an annular throttle clearance between the limiter 13 and the hole 20.

The holes 15 form an additional throttle channel and provide a soft damping characteristic of the spring when the annular piston 7 moves between its extreme positions on the rod 11, which is necessary for effective damping of oscillations with a small amplitude and when the directions of movement of the body and wheel coincide. The main throttle channel 16 provides a rigid damping characteristic of the spring at the extreme positions of the annular piston 7 on the rod 11, which is necessary for effective damping of large-amplitude oscillations. The non-return valve 17 provides an asymmetric damping characteristic of the spring with a weakened resistance during compression. An annular throttle clearance between the axial hole 20 and the limiter 13 provides an increase in the stiffness of the damping characteristic at the end of the spring compression stroke, which is necessary to prevent hard breakdowns of the suspension.

The proposed air-hydraulic spring suspension of the vehicle operates as follows.

During spring compression, the rod 3 with the piston 2 enters the cylinder 1, the fluid from the piston cavity 4 flows into the hydraulic cavity 9 of the accumulator 6 through the valve 7, which causes the floating piston 8 to move and the gas to compress in the pneumatic cavity 10. During the rebound, t. e. when the rod 3 with the piston 2 leaves the cylinder 1, the pressure in the cavity 4 decreases, and under the influence of the pressure drop the floating piston 8 moves in the opposite direction, the gas in the cavity 10 expands, and the liquid from the cavity 9 flows into the cavity 4 through the valve 7. When depending on the vibration modes of the spring, the following modes of operation of the valve 7 are possible.

When working springs with large amplitudes at the beginning of each cycle of oscillations under the action of a pressure differential between the cavities 4 and 9, the annular piston 7 moves in the cylinder 1 along the rod 11 to the left or to the right before interacting with the stop 12 or the stop 13, respectively. In this case, a pressure differential is created only at the holes 15 of the additional throttle channel with low resistance, since the annular piston 7 moves practically together with the liquid, and the fluid flow between the cavities 4 and 14 through the main throttle channel 16 and the holes 18 of the check valve 17 is insignificant. After stopping the annular piston 7, a pressure drop during rebound is created on the main throttle channel 16 with high resistance, and during compression, on the main throttle channel 16 and holes 18 of the check valve 17, since its valve disc 17 moves to the left to the stop in the fluid flow snap ring 19. This provides increased rigidity of the damping characteristic and its asymmetry in the compression and rebound moves. Since the operating time of a spring with a soft characteristic is insignificant and occurs at the beginning of spring deformation, when the deformation rate and damping force are small, high damping of large-amplitude oscillations, which take place mainly in the low-frequency resonance zone of the body, is ensured.

If maximum permissible fluctuations occur during compression of the spring, the restrictor 13 enters the blind hole 20, as a result of which the liquid from the internal cavity 21 is forced into the piston cavity 4 through the annular throttle gap formed by the hole 20 and the limiter 13. As a result, an additional increase in the damping force at the end is created compression stroke, which reduces the likelihood of breakdown of the suspension.

When the spring with small amplitudes of oscillation is working, the annular piston 7 moves in the cylinder 1 along the rod 11, almost without interacting with the stop 12 and the limiter 13, and the spring has a soft damping characteristic regardless of the static position of the piston 2 in the cylinder 1, which is necessary for effective damping of resonance body vibrations at any degree of vehicle loading.

Thus, self-regulation of the hydraulic resistance of the spring by the amplitude of the oscillations is ensured.

In case of random vibrations of the spring with different amplitudes and frequencies, for example, with large low-frequency vibrations of the body and small high-frequency vibrations of the wheel, the direction of movement of the body and wheel may coincide. At the same time, during compression or rebound of the spring under the action of low-frequency body movement up or down, the annular piston 7 is mainly located in its extreme positions, providing a rigid asymmetric damping characteristic necessary for efficient damping of body vibrations. With a sharp change in the direction of spring deformation as a result of a wheel falling into a hole or hitting a hill, the annular piston 7 almost instantly moves to the right or left, providing a soft damping characteristic for the magnitude of these displacements necessary to reduce the impact of the road on increasing body vibrations when coincidence of the directions of motion of the body and wheel in a vertical plane. Thus, self-regulation of the hydraulic resistance of the spring in the direction of oscillation is ensured.

The annular cavity 5 of the cylinder 1 can be used to divert leaks of fluid leaking through the seal of the piston 2 into the hydraulic system of the vehicle, or to supply fluid when lifting the wheel.

The proposed pneumohydraulic spring of the vehicle suspension has a simple and reliable design and provides self-regulation of its damping characteristics in terms of amplitude and direction of vibration, reduction of dynamic loads acting on the spring, increase in the spring stroke of the spring with weakened damping without increasing the dimensions of the spring, asymmetry of the damping characteristics on the compression and rebound , as well as an increase in its rigidity at the end of the compression stroke. The use of this spring will lead to a decrease in the vibration load and heating of the suspension, a decrease in the total energy loss caused by vibrations, an increase in average speeds and performance when driving on virtually any road with any degree of vehicle loading, and also to lower operating costs.

Thus, the foregoing indicates that when using the claimed invention the following combination of conditions:

- the pneumohydraulic spring of the vehicle suspension, embodying the claimed invention in its implementation, is intended for use in the suspension of vehicles and provides, with a simple and reliable design, self-regulation of hydraulic characteristics depending on the amplitude and direction of vibration, which reduces the dynamic load on the suspension, increases the smoothness of the vehicle means in any road conditions and reduces operational costs;

- for the claimed invention in the form described in the claims, the possibility of its implementation in accordance with the description and the attached drawing is confirmed;

- pneumohydraulic spring embodying the claimed invention in its implementation, is able to ensure the achievement of the perceived by the applicant technical result.

Therefore, the claimed invention meets the requirement of "industrial applicability".

Claims (1)

A pneumatic-hydraulic spring of a vehicle suspension comprising a cylinder in which a piston with a rod is mounted, forming a piston and an annular cavity in the cylinder, and a hydraulic accumulator connected to the cylinder cavity through a valve that is self-adjustable in amplitude and direction of oscillation, characterized in that the valve is made in the form of an annular piston installed in the cylinder with the possibility of axial movement along the valve stem, one end of which is connected to a support mounted on the end of the cylinder, and on the other end n the stroke limiter of the annular piston, which forms an annular valve cavity with the cylinder, connected to the hydraulic accumulator through holes made in the support, forming an additional throttle channel, and communicated with the piston cavity through the main throttle channel, made in the annular piston, and through a check valve installed with one of the sides of the annular piston, and in the piston with the rod a blind axial hole is made, into which a limiter enters at the end of the spring compression stroke, forming the maximum damper cavity oscillations communicating with the piston cavity.