RU2240930C1 - Controllable suspension - Google Patents

Abstract

FIELD: transport engineering.

SUBSTANCE: invention relates to vibration protection systems of vehicles, carried loads and crew. Proposed controllable suspension contains hydraulic cylinder, working rod with piston, control system two gangs of compressed gas bottles series-connected by hydraulic main line and consisting of two chambers divided by flexible impermeable partition. Magnetic liquid damper is installed at inlet of each bottle. Said dampers are furnished with electromagnets and are connected with control system. Part gang is connected to piston space of hydraulic cylinder, and second one, to rod space of hydraulic cylinder. Under static conditions, pressures in compressed gas bottles follow the following relatioship

where

and magnetic liquid, percent content of magnetic particles 1-10% by volume, is used as liquid, invention provides enlargement of functional capabilities of device by excluding constant influence of pressure in gas space of suspension on rate of reduction of overloads of object to be protected from vibration.

EFFECT: provision of quick action and stability of functioning of controllable suspension, improved reliability.

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Description

The invention relates to transport machinery, and more particularly to vibration protection systems in transport.

Known [1] is a self-regulating air-hydraulic spring containing a body with a cylinder in which a rod with a piston separating the cylinder cavity and a vehicle position controller (TC), a reservoir with oil, accumulating and regulating hydraulic accumulators, metering, correcting and non-return valves are placed. Such a spring provides, due to a change in the pressure value, a constant frequency of the natural oscillations of the vehicle (TS) when changing its load [1]:

where ω _z , ωφ - oscillation frequency of the sprung mass of the vehicle in the vertical and transverse-angular directions, respectively;

C _pi is the stiffness of the spring of the i-th axis;

n is the number of axles of the vehicle;

M _p - the value of the sprung mass of the vehicle;

J _p - moment of inertia of the sprung mass relative to the longitudinal axis of the vehicle.

A disadvantage of the known self-regulating air-hydraulic spring is the influence of the pressure in the gas cavity of the spring on the resistance to vibration and shock when the vehicle moves on roads of various categories with variable speeds.

The closest in technical essence to the proposed one is a device for damping object vibrations, comprising a housing, a working rod with a piston, a floating piston, a compressed gas cylinder, consisting of two chambers separated by a flexible impenetrable partition, a control system [2].

The disadvantages of the known device for damping object vibrations are the effect on the efficiency of operation, namely on the speed and resistance to vibration and shock disturbances, the gas pressure in the chamber and the presence of suspended floating pistons, which reduce the reliability of the operation of systems of this type.

The required technical result is to expand the functionality of the device by eliminating the influence of a constant value of pressure in the gas cavity of the suspension on the degree of reduction of overloads of the depreciation object, the speed and stability of the functioning of the controlled suspension under the action of vibration and shock disturbances caused by the movement of vehicles on roads of various categories with variable speeds, and also providing increased levels of reliability.

The required technical result is achieved in that the suspension comprising a hydraulic cylinder, a working rod with a piston, a control system, is equipped with two sections of cylinders with compressed gas, the sections are made in the form of cylinders connected in series with a hydraulic line, consisting of two chambers (gas and liquid), separated by a flexible impermeable a partition, at the entrance of which dampers are installed on magnetic fluid, dampers are equipped with electromagnets and connected to the control system, the first section is connected to the piston cavity of the hydrocyclone Indra, the second - to the rod end of the hydraulic cylinder; in the static position, the pressure values in the cylinders with compressed gas obey the dependences (2)

- значение давления газа в 1-ом баллоне секции сжатия в статическом положении;Where

- the value of the gas pressure in the 1st cylinder of the compression section in a static position;

- значение давления газа в i-ом баллоне секции сжатия в статическом положении;

- the value of the gas pressure in the i-th cylinder of the compression section in a static position;

- значение давления газа в j-ом баллоне секции отбоя в статическом положении;

- the value of the gas pressure in the j-th cylinder of the rebound section in a static position;

α _i is the dimensionless coefficient relating the pressures in the 1st cylinder and the i-th balloon of the compression section;

β _j is a dimensionless coefficient relating pressure in the 1st cylinder of the compression section and the jth balloon of the rebound section;

i, j are cylinder numbers in the compression and rebound sections, respectively, and magnetic fluid with a percentage of magnetic particles of 1 ... 10% by volume is used as the liquid.

The range of dimensionless coefficients α _i and β _j is due to their dependence on the size and distribution of the sprung mass along the length of the vehicle. The given ranges of coefficients α _i and β _j make it possible to control the elastic and damping components of the force developed by the suspension by 3 ... 5 times on a time scale close to real, which will reduce the maximum acceleration values of the sprung masses of the vehicle by 20 .. .70% when driving on roads of I ... IV categories and explored terrain in the range of operating speeds.

The range of values of the percentage of magnetic particles in the liquid is due to the need to select the optimal combination of the dimensionless coefficients α _i and β _j and the concentration of magnetic particles by volume of the liquid in order to provide the necessary range of regulation of the elastic and damping components of the force developed by the suspension due to the operation of the chokes. The dependence of the damping component of the force generated in the magneto-liquid damper on the concentration of magnetic particles is determined by the following formula (3):

where H ₀ - the intensity of the external magnetic field created by the electromagnetic coil of the damper;

λ is the electrical conductivity of the magnetic fluid;

η ₀ is the viscosity of the carrier fluid;

K is a coefficient depending on the shape of the particles;

C _V is the volume concentration of particles in the magnetic fluid;

L, B, f _DR - geometric parameters of the magneto-liquid damper (MJ);

V is the flow rate of the magnetic fluid in the working channels of the MOR.

The presented range of changes in the concentration of magnetic particles in a liquid allows, in combination with the structural solutions implemented in the Moscow Railway, to provide control of the damping force by 3 ... 5 times, which will redistribute the magnetic fluid between the cylinders with compressed gas, the gas pressure values in which may differ several times.

Analysis of the scientific and technical literature showed that prior to the filing date of the application, there were no devices with the indicated set of features. Therefore, the proposal meets the requirement of novelty.

In addition, the required technical result is achieved by the entire newly introduced set of essential features, using two sections of cylinders separated by a flexible impermeable partition into cavities with liquid and compressed gas, for example nitrogen, each of which is a series of cylinders connected in series with a hydraulic line, at the entrance of which dampers are installed on magnetic fluid, equipped with electromagnets and connected by a control system, the first of the sections is connected to the rod end of the hydraulic cylinder, and in oraya - a piston in a static position the pressures in cylinders of compressed gas depending obey

and as a liquid, magnetic fluid is used with a percentage of magnetic particles of 1 ... 10% by volume, which is unknown in the well-known scientific and technical literature. Therefore, the proposal meets the requirement of inventive step.

The drawing shows a schematic diagram of a controlled suspension. The controlled suspension comprises a hydraulic cylinder 1, a working rod with a piston 2, a hydraulic highway 3 connecting the fluid cavities 7 of the cylinders 5, separated by a flexible impermeable partition into a fluid 7 and a gas cavity 6, with a rod (A) and piston (B) cavities of the hydraulic cylinder; on hydraulic lines 3, before each compressed gas cylinder, a magneto-liquid damper 4 is installed, to which signals from the control system 8 are received.

Magneto-liquid dampers 4 can be made in the form presented in [3, 4, 6, 7]. The control system can be performed similarly to the control systems described in [5, 6, 7], it can be controlled according to one parameter (for example, acceleration) or for several parameters (for example, acceleration, speed, movement, pressure, etc. .), it can include information sensors (for example, acceleration, velocity, displacement, pressure, etc.) sensors, an amplifier-converter (logic device, power amplifier) and actuators (for example, electromagnetic coils).

. По сигналу от датчиков информации системы управления 8 в магнитожидкостных демпферах 4, установленных на гидромагистралях 3, наводятся электромагнитные поля, которые вызывают изменения эффективной вязкости магнитной жидкости, находящейся в проходном канале каждого магнитожидкостного демпфера, изменение вязкости и перераспределение потока магнитной жидкости между баллонами со сжатым газом осуществляются в соответствии с алгоритмами, позволяющими сформировать рациональные значения упругой и демпфирующей характеристик подвесок транспортного средства и снизить перегрузки объекта амортизации до допустимых величин при движении по дорогам различной категории с переменными скоростями.Managed suspension works as follows. When the vehicle is moving, a disturbance acts on it from the side of the road surface

. The signal from the sensors of the control system information 8 in the magneto-liquid dampers 4 installed on the hydraulic lines 3 induces electromagnetic fields that cause changes in the effective viscosity of the magnetic fluid located in the passage channel of each magneto-liquid damper, a change in viscosity, and redistribution of the magnetic fluid flow between the cylinders with compressed gas are carried out in accordance with algorithms that allow the formation of rational values of the elastic and damping characteristics of trans suspension a sports vehicle and reduce the overload of the depreciation facility to acceptable values when driving on roads of various categories with variable speeds.

Thus, due to the introduction of two sections of cylinders, separated by flexible impermeable baffles into liquid and gas cavities, connected by liquid cavities to the rod and piston cavities of the hydraulic cylinder with magnetic dampers installed in front of the cylinders controlled by the control system, the functionality of the proposed device is significantly expanded, since This controlled suspension allows you to implement control of the elastic and damping suspensions components of the effort, creating forward in suspension, and thus forming in the system according to a predetermined control algorithm rational values of elastic-damping characteristics, providing reliable overload reduction facility depreciation of the vehicle when driving on the roads of different categories of traffic with variable speeds.

However, when you turn off the control system of the viscosity of the magnetic fluid, it is possible to form efforts according to the law implemented on the prototype device, that is, in the particular case, the functionality of the prototype device is preserved.

Sources of information

1. USSR author's certificate No. 1134820, F 16 F 5/00. Self-adjusting pneumo-hydraulic spring. /THEM. Ryabov, V.V. Novikov.

2. USSR author's certificate No. 1024615, F 16 F 9/50, 1983, a device for damping object vibrations.

3. USSR author's certificate No. 989945, F 16 K 31/02, 1979, publ. in BI 1982, No. 19. Magneto-liquid choke.

4. USSR Author's Certificate No. 669141, F 16 K 31/02, 1977, publ. in BI 1979, No. 23. Magneto-liquid choke.

5. Depreciation device. / Rulev S.V., Gerasimchuk V.V., Savostyanov A.M. et al. Patent for invention No. 2066005. - M.: Rospatent, 1996, 12 p.

6. Scientific and technical report “Vibration protection systems. Patent Research. ” NTO-540-14F12-33-89 / Savostyanov A.M., Moisheev A.A., Biryukov A.S. et al. - M.: NPO im. A.S. Lavochkina, 1989, 241 p., Ill.

7. Controlled magneto-liquid vibration isolators. / Rulev S.V., Samsonov V.N., Savostyanov A.M. et al. - M .: Moscow, 1988, 207 pp., ill.

Claims (1)

A controlled suspension containing a hydraulic cylinder, a working rod with a piston, a control system, characterized in that two sections are introduced, each section is made in the form of compressed gas cylinders connected in series by a hydraulic line, consisting of two chambers separated by a flexible impermeable partition, one camera is connected to the hydraulic line and is filled with magnetic fluid, and the other chamber is filled with compressed gas, a damper on the magnetic fluid is installed at the inlet of each cylinder, the dampers are equipped with electromagnets and connected to the system My control, the first section is connected to the piston cavity of the hydraulic cylinder, the second to the rod cavity of the hydraulic cylinder, in a static position, the pressure values in the cylinders with compressed gas obey the dependencies

where P $\genfrac{}{}{0ex}{}{\text{squ}}{\text{0.1}}$ - the value of the gas pressure in the 1st cylinder of the compression section in a static position; R $\genfrac{}{}{0ex}{}{\text{squ}}{\text{0, i}}$ - the value of the gas pressure in the i-th cylinder of the compression section in a static position; R $\genfrac{}{}{0ex}{}{\text{otb}}{\text{0, j}}$ - the value of the gas pressure in the j-th cylinder of the rebound section in a static position; α _i is the dimensionless coefficient relating pressure in the 1st cylinder and the i-th balloon of the compression section, 0 <α _i <3; β _j is a dimensionless coefficient relating pressure in the 1st cylinder of the compression section and the jth balloon of the rebound section, 0 <β _j <3; i, j = 1-10, cylinder numbers in the compression and rebound sections, respectively, and as the working fluid is used magnetic fluid with a magnetic particle content of 1 ... 10% by volume.