RU201650U1 - Active vehicle seat suspension - Google Patents

Abstract

The utility model relates to vehicle seat suspensions. The vehicle seat suspension includes a hydraulic cylinder and a hydraulic damper located between the base and the upper pair of slats. The piston cavity of the hydraulic cylinder is connected by means of an adjustable throttle to the cavity "a" of the pneumatic accumulator filled with liquid, and the cavity "b" is filled with gas (nitrogen). This makes it possible to obtain a non-linear characteristic of the pneumatic accumulator. In this case, the control throttle is controlled by the electronic control unit, depending on the intensity of the vibrations. 1 ill.

Description

The utility model relates to transport engineering, in particular to the seat suspensions of agricultural vehicles and tractors.

The known design of the active suspension of the vehicle seat, selected as a prototype, contains a coil spring installed between the base and the upper pair of seat suspension strips, a hydraulic damper, a shock absorber sensor (electronic converter) installed between the base and the seat frame, as well as an acceleration sensor ( vibration accelerometer), an electronic control unit and a position sensor (resistor) installed between the base and the seat suspension frame (description for RU 139995 U1, B60N 2/50 04/27/2014 Bull. No. 12).

The disadvantage of the known design is that the coil spring installed between the base and the upper pair of strips has a linear characteristic and this causes resonance oscillations in certain operating modes even in the presence of a damper equipped with a magnetorealogic fluid.

The challenge is to improve the performance of the seat suspension by increasing the speed of transport vehicles while keeping vibration levels within normal limits in all operating modes.

The technical result is an increase in the efficiency of damping vertical vibrations of the seat, depending on the intensity of changes in the disturbing effect on the seat during vibrations in a wide amplitude-frequency range, by introducing a nonlinear characteristic into an elastic element, since resonant vibrations occur in certain operating modes and such vibrations can be eliminated a pneumohydraulic accumulator with a non-linear characteristic and only in conjunction with a hydraulic damper.

The technical result is achieved by the fact that in the active suspension of the vehicle seat, including a hydraulic damper filled with a magnetorheological fluid, a control element, electronic vibration and position sensors, an electronic control unit, a pneumatic accumulator and a hydraulic cylinder are made as an elastic element, the subpiston cavity of which, through an adjustable the throttle is connected with a pneumatic accumulator and an electronic control unit.

The figure shows a schematic diagram of the seat suspension.

The vehicle seat suspension consists of a pair of slats 11, a hydraulic cylinder 1, the sub-piston cavity of which is filled with hydraulic fluid and connected through an adjustable throttle 3 with the cavity "a" of the pneumatic accumulator 2, the cavity "b" is filled with gas (nitrogen), and installed between the base 4 and the frame seat 7, a hydraulic damper 5, the active element of which is a magnetorheological fluid, a damper sensor (electronic transducer) 6 installed between the base 4 and the seat frame 7, an acceleration sensor (vibration accelerometer) 8, an electronic control unit 9 and a position sensor (resistor) 10 also installed between the base 4 and the seat suspension frame 7.

When the driver sits on the seat (depending on his weight), the signal from the position sensor 10 is sent to the electronic control unit 9, where it is subsequently processed and fed to the adjustable throttle 3 and the electronic converter 6. The driver's weight itself will be compensated by the hydraulic cylinder 1, piston the cavity of which, through an adjustable throttle 3, is connected to a pneumatic hydroaccumulator 2.

During operation, the seat suspension is subject to vibration transmitted from the environment and vehicle machinery. This impact is successively transmitted to the base 4 and the seat frame 7.

When working with small vibration amplitudes, the dominant value is taken by the signal level coming from the vibration sensor 8, which are fed to the adjustable throttle 3, which, in turn, regulates the fluid flow into the pneumatic accumulator 2, thereby maintaining the optimal stiffness and damping of the suspension. In this case, the signal level from the electronic control unit to the electronic transducer 6 is insignificant, therefore, in the damper 5 there is no magnetic effect on the liquid, and it flows from one cavity to another with insignificant damping.

This hydraulic cylinder 1 with a pneumatic accumulator 2 acts as an elastic element with a non-linear characteristic that maintains optimal rigidity and damping. Due to the adjustable throttle 3, which receives a control signal from the control unit 9, depending on the value of the signal, the throttle opens to a certain amount, which ensures the flow of hydraulic fluid into the cavity "a" of the pneumatic accumulator, cavity "b" is filled with gas (nitrogen). The direction of the flow of hydraulic fluid from the hydraulic cylinder 1 to the pneumatic accumulator 2 (or per revolution) will depend on the direction of the seat movement, up or down, and on the signal level from the position sensor 10 and the ECU to the adjustable throttle 3.

When increased seat vibrations occur, an electrical signal appears on the acceleration sensor 8, which is fed to the electronic control unit 9. The electronic unit 9 controls the operation of the electronic converter 6, with the help of which the current in the electromagnetic coil of the hydraulic damper 5 changes, while the signal also goes to adjustable throttle 3, which leads to a change in the rigidity and damping qualities of the pneumatic accumulator 2 of the seat suspension. The control signal from the electronic unit 9 is supplied constantly when the acceleration caused by vibration in the seat 7 exceeds the permissible values. This may be due to the vehicle hitting a large unevenness or due to the coincidence of the natural vibration frequency of the seat suspension with the frequency of the driving force, i.e. hitting the resonance zone. And the higher the obtained value of acceleration, the greater will be the control signal supplied to the electronic converter 6 and a large current is supplied to the electromagnetic coil 6 of the hydraulic damper 5 and to the throttle 3. This will make it possible to timely change the viscosity of the liquid in the damper 5 and change the rigidity of the pneumatic accumulator 2, which will make it possible to more efficiently damp the vibration that has arisen and prevent the acceleration limit values from being exceeded. The process of supplying a control signal to the electronic converters is carried out depending on which position relative to the equilibrium state or the initial position is the seat 7. This position is determined at the beginning of work using the position sensor 10, the signal from which also goes to the electronic control unit 9, where its subsequent processing. The signal level from the position sensor 10 depends on the driver's weight. The driver's weight itself will be compensated by a hydraulic cylinder 1, the sub-piston cavity of which is connected to a pneumatic accumulator 2 through an adjustable throttle 3.

Claims (1)

The vehicle seat suspension, including an elastic element, a hydraulic damper filled with a magnetorheological fluid, a control element, electronic vibration and position sensors, an electronic control unit, characterized in that the elastic element is made in the form of a pneumatic accumulator and a hydraulic cylinder, the subpiston cavity of which is connected to pneumatic accumulator and electronic control unit.

Images