RU2325568C1 - Pneumatic suspension - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: pneumatic suspension comprises a rubber-cord casing with a cover, which form main working cavity, additional cavity located inside the main working cavity and co-axial thereto, and a baffle between them. On the baffle, a cylinder-type valve unit is rigidly secured. The cylinder bottom is attached to the baffle and has axial openings. In the cylinder wall, there are axial channels, which connect the working cavity with the cylinder cavity. In the cylinder end cover, there are axial openings, elastic valves, which contact the axial openings in the cylinder bottom and its end cover at the beginning of compression or retraction, respectively. In the cylinder end cover and bottom, solenoid windings are installed. Inside the cylinder cavity, isolation valve of piston type is installed. Both ends of the piston are provided with guiding magnet plungers with retracting springs installed inside the solenoid windings connected to the valve control system. The valve control system comprises a displacement transducer, a speed signal conditioner, a differential steering unit, switch control units, power circuit limit switches for connecting solenoid windings to the power supply. The displacement transducer is connected to the speed signal conditioner, which is connected to the differential steering unit, outputs of which are connected to inputs of power-circuit limit switch control units. Outputs of the units are connected to control inputs of power-circuit limit switches.

EFFECT: enhanced damping properties of pneumatic suspension.

2 cl, 3 dwg

Description

The invention relates to the field of engineering, in particular to shock-absorbing devices using gas in a chamber with an elastic wall.

A device for damping the vertical vibrations of vehicles is described, as described in A.S. No. 261926, M. cl. B60G 11/26, containing a rubber-cord sheath with a lid, an additional container, a partition between them with calibrated holes, and a valve device in the form of a diaphragm hanging freely on the partition, overlapping the bypass holes during rebound.

The main disadvantages of the device include the fact that during forced oscillations of a shock-absorbed object with large amplitudes, its average position shifts down from the original one due to the constant accumulation of compressed gas energy in an additional tank at the beginning of each compression stroke, which leads to a decrease in the suspension suspension dynamic motion and a decrease in the damping efficiency fluctuations.

Also known is a pneumatic suspension device described in A.S. No. 968536, M. cl. F16F 9/04 (prototype), containing a rubber-cord casing with a cover, forming the main working cavity, an additional tank installed coaxially and inside the main working cavity, a partition located between them, on which a valve cylinder device with a rod is rigidly fixed. The valve device is actuated by the stem with the direct impact of a cover rigidly moving with the shock-absorbing object. In the partition there is a calibrated hole and a safety valve for gas overflow during operation. The main and additional elastic elements of the air suspension are installed between the sprung and unsprung masses of the depreciable object.

The main disadvantage of this device is the instability of the damping properties of the suspension and the low efficiency of dissipation of the vibrational energy of the object due to the fact that the switching of volumes in the air suspension is carried out using an inertial mechanical valve device, actuated by the rod when the cap is directly exposed to it, which moves rigidly with the shock-absorbing object. The valve device in the known air suspension provides switching volumes in the air suspension tanks at the beginning of each compression and rebound stroke with a delay relative to the beginning of the compression and rebound stroke, because the bypass holes in the cylinder of the valve device are opened or closed by the piston at the end of the stroke of the piston driven by the rod, which leads to the presence of dead zones. Thus, the start of switching volumes occurs with a delay after the start of working out both the compression stroke and the rebound stroke. The main driving force for the production of entropy in a pneumatic suspension, and, consequently, for energy dissipation, is the difference in the thermodynamic potentials of gases in volumes related to their absolute temperatures. The valve device must create the greatest values of this difference during the oscillations of the object and, at certain points in the oscillation period, namely at the beginning of the compression and rebound, carry out short-term quick switching of the air suspension volumes in order to quickly convert the difference of thermodynamic potentials into entropy production and into dissipation of vibrational energy depreciable object.

The task of the invention is to increase the damping properties of the air suspension.

The problem is achieved in that in the known air suspension containing a rubber-cord shell with a cover, forming the main working cavity, an additional tank installed coaxially and inside the main working cavity, a partition located between them, on which the valve device made in the form of a cylinder is rigidly fixed, the bottom of which is connected with the partition and has axial openings, and axial channels are made in its wall connecting the working cavity with the cylinder cavity, in the end cover of the cylinder axial holes, elastic valves interacting with axial holes in the bottom of the cylinder and its end cap, respectively, at the beginning of the compression stroke and rebound stroke, according to the invention, electromagnet windings are installed in the cylinder end cap and its bottom, and a shut-off valve in the form of a piston is installed inside the cylinder cavity having magnetic guide cores on both sides, equipped with return springs installed inside the windings of the electromagnets connected to the valve control system.

The valve control system comprises an object displacement transducer, an object speed signal conditioner, a control separation unit, key control units, power keys for connecting electromagnet windings to a power source, the object displacement converter being connected to an object speed signal conditioner, which is connected to the control separation unit, the outputs are connected to the inputs of the power switch control units, and the outputs of these blocks are connected to the control inputs of the power switches.

The invention is illustrated by drawings, where

- figure 1 presents the proposed air suspension;

- figure 2 presents the electrodynamic valve;

- figure 3 shows a structural diagram of a valve control system;

- figure 4 presents the elastic damping characteristics of the air suspension.

The air suspension comprises a rubber-cord casing 1 with a cover 2, forming the main working cavity 3, an additional tank 4, a partition 5 located between them with a valve device 6 and a valve control system 7.

The valve device includes a guide cylinder 8, a reciprocating shut-off valve 9 moving inside its cavity, in the form of a piston having magnetically conducting guide cores 10 and 11 provided with return springs 12 on both sides thereof and a valve device cover 13. In the upper part inside the cylinder 8 and in the cover 13 of the valve device 6, windings 14 and 15 of pulsed-pull electromagnets are installed, inside of which the cores 10 and 11 are moved and the springs 12 are installed. At the end of the guide cylinder 8 and on the cover of the valve device 13, flexible check valves are mounted 16 and 17. The cylinder 8 has axial holes 18, and axial channels 19 are made in its wall, connecting the main working cavity 3 of the air suspension with the cavity of the cylinder 8 and blocked by a shut-off valve 9 during compression. In the cover of the valve device 13, axial holes 20 are made 20. In the wall of the cylinder 8 there are made radial bypass holes 21 located in the same plane and blocked by a shut-off valve 9 during the rebound. The axial holes 18 and 20 are overlapped by elastic check valves 16 and 17.

The valve control system comprises an object displacement transducer 22, an object speed signal generator 23, a control separation unit 24, key control units 25 and 26, power keys 27 and 28 for connecting the electromagnet windings 14 and 15 to a power source, the object displacement transformer 22 being connected to a speed signal shaper 23 of the object, which is connected to the control separation unit 24, its outputs are connected to the inputs of the control units 25 and 26 by power switches 27 and 28, and the outputs of the blocks 25 and 26 are connected to the control odes power switches 27 and 28.

Air suspension works as follows.

During compression of the air suspension (point "a" on the elastic-damping characteristic, Fig. 4.), the signal from the displacement transducer 22, converted by the control system elements 23, 24, 26, is supplied to the power switch 28, including the electromagnet 15, and the shutoff valve 9 closes axial and radial holes 19 and 20 of the valve device. The pressure in the working volume of the air suspension increases (curve a-b). At point "b" begins the rebound and the electromagnet 15 is de-energized. The shut-off valve 9 will take a neutral position due to the action of the return springs 12 and the gas through the holes 19 and 20 and the check valve 17 passes from the working volume to the additional volume (curve b-c). At point “c” the pressure in the air suspension volumes is equalized. At the beginning of the rebound stroke, the signal from the displacement transducer 22, converted by the control system elements 23, 24, 25, is supplied to a power switch 27 including an electromagnet 14, and a shut-off valve 9 blocks the axial and radial openings 18 and 21 of the valve device. During rebound, the pressure in the working volume of the air suspension decreases sharply (curve c-d). At point "d" the next compression stroke begins and the electromagnet 14 is de-energized. The shut-off valve 9 will take a neutral position due to the action of the return springs 12 and the gas through the holes 18 and 21 and the check valve 16 flows from the additional volume into the working volume (curve d-a). At point "a" the pressure in the volumes is equalized.

The area of the loop on the elastic-damping characteristic (curve a-b-c-d-a, Fig. 4) reflects the amount of energy absorbed by the air suspension for one period of oscillation of the object. As can be seen from figure 4, the proposed pneumatic suspension with an electrodynamic valve and its control system satisfy the requirements of high speed and provide quick pressure equalization in the suspension tanks at the beginning of each compression and rebound stroke, exclude energy storage in the working cavity 3 and additional capacity 4, reduce the relative moves of the depreciable object.

Thus, the proposed air suspension improves damping properties and overall performance.

Claims (2)

1. An air suspension containing a rubber-cord casing with a cover, forming the main working cavity, an additional tank installed coaxially and inside the main working cavity, a partition located between them, on which a valve device is made rigidly, made in the form of a cylinder, the bottom of which is connected to the partition and has axial holes, and in its wall there are axial channels connecting the working cavity with the cylinder cavity, axial holes, elastic valves, mutually Acting with axial holes in the bottom of the cylinder and its end cap, respectively, at the beginning of the compression and rebound stroke, characterized in that electromagnet windings are installed in the end cap of the cylinder and its bottom, and a shut-off valve in the form of a piston having both sides guide magnetic conductors equipped with return springs installed inside the windings of the electromagnets connected to the valve control system. 2. The air suspension according to claim 1, characterized in that the valve control system comprises an object displacement transducer, an object speed signal driver, a control separation unit, key control units, power switches for connecting electromagnet windings to a power source, the object displacement transducer being connected to by an object speed signal shaper that is connected to the control separation unit, its outputs are connected to the inputs of the power switch control units, and the outputs of these control units us to the control inputs of power switches.

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