Soft and stable automobile suspension

Abstract

An elastic vehicle suspension in which shock absorption is provided by hydraulic balancers controlled by an electronic system (figure 2). On the basis of data from sensors for detecting the reaction force of resilient elements of the suspension, from horizontal acceleration sensors and from sensors for detecting the force generated by the hydraulic balancers, the electronic system generates signals for each balancer so that the forces generated thereby compensate for forces and moments that disturb the balance of the sprung mass. The force generated by a balancer depends only on the intensity of a current in solenoids. This is achieved by controlling the pressure of a fluid medium at both ends of a piston. The suspension in which shock absorption is provided by balancers imparts a soft ride property and stability to an automobile because the suspension does not transmit shocks and reliably restrains the automobile against pitching and rolling.

Description

[0001] SOFT and STABLE CAR SUSPENSION.

[0002] Field of technology

[0003] The invention relates to the field of transport engineering, namely suspension devices for motor vehicles (hereinafter referred to as MV).

[0004] Prior art

[0005] The elastic suspension is designed to isolate the vehicle body from the unevenness of the road. Springs (elastic elements) isolate. The use of elastic elements for softening inevitably leads to a deterioration in the stability of the vehicle. To restore stability, mechanical anti-roll bars operating on torsion are used in most cases. Natural vibrations occurring in the suspension are best stopped by EQUILIBRATORS. The operation of the suspension with equilibrators is described in the international application PCT / RU2021 / 000141 as well as in the patent RU 2676843. The main principle of this suspension is to balance the sprung mass with EQUILIBRATORS. That is, EQUILIBRATORS generate forces that are necessary and sufficient to keep the vehicle body in equilibrium. However, the force generated by the ATOP EQUILIBRATOR significantly depends on the speed of the piston. The reason for this is the instability of the pressure drop in the equilibrator check valves. This makes it difficult to balance during sharp shocks.

[0006] Disclosure of invention

[0007] The essence of this invention is that the fluid pressure in the EQUILIBRE ATOP AX is regulated not only in the compression cavity, but also in the expansion cavity. The proposed EQUILIBRE ATOP (Fig.l) has a hydraulic cylinder filled with a fluid. The piston (1) divides the hydraulic cylinder into two working cavities. There is a third cavity (2) that plays the role of a reservoir, we will call it: "low pressure cavity". During the approach movement, the fluid from the first working cavity (3) is displaced through the controlled pressure valve (4) into the low pressure cavity (2), and into the second working cavity (5), the fluid is sucked from the low pressure cavity (2) through the uncontrolled pressure reducing valve (8), which stabilizes the vacuum in the second working cavity (5).During the removal movement, the fluid medium from the second working cavity (5) is forced out into the low-pressure cavity (2) through the second controlled pressure valve (7), and the fluid medium is sucked into the first working cavity (3) through the second uncontrolled pressure-reducing valve (6) from the low-pressure cavity (2). The main feature of the proposed EQUILIBRIER ATOP A is that the force it generates does not depend on the speed of movement of its working element over the entire working range, does not depend on the viscosity and temperature of the fluid, and depends only on the strength of the electric current in the solenoids (9) of the electromagnetic pressure valves. For the equilibrator to work correctly, the pressure in the working cavities must exactly match the current in the solenoids. For this, the end parts of the spool valves, which are affected by the pressure of the working cavities, go directly into the working cavities.To reduce the control current in the solenoids while maintaining a sufficient nominal area of ​​the valve passage, the end parts of the spools have a relatively small area.

[0008] The damping system operation (Fig.2) is controlled based on the data obtained from the sensors measuring the reaction force of each spring separately (P1; P3; P8; P10), from the sensors measuring the force generated by each equilibrator (P2; P4; P9; P11) and from the sensors measuring the torques of the anti-roll bars (P5; P12). The signal from the spring reaction force sensor, for example the front left one (P1), is fed to the direct and inverse inputs of the operational amplifier (A1) (hereinafter referred to as OP) through the resistors (R1; R2). The inverse input of the OP (A1) is shunted by a capacitor (C1) on which the potential corresponding to the average value of the reaction force of the front left spring is stored. Thus, a signal corresponding to the deviation of the reaction force of the front left spring from the average value is formed at the output of the OP (A1). This signal is then fed through the op-amp (A6) to the front left equalizer (EQ1).The positive signal at the output of the OU (A6) goes to the controlled pressure valve (Y4), which sets the maximum pressure in the compression cavity of the EQUILIBRATOR (EQ1) during the moving away movement. The negative signal goes to the pressure valve (Y3), which sets the maximum pressure in the compression cavity during the moving closer. The signals for all equilibrators are formed in a similar manner.

[0009] The control algorithm is as follows: When driving over an uneven surface, the EQUILIBRATORS do not prevent the wheel from moving away from the equilibrium point and balance the suspension when the wheels move toward the equilibrium point. The torque that occurs during asymmetrical movement of the wheels of one axle is compensated by the equilibrators of the other axle. The signal for compensating the torque that occurs in the front suspension is formed at the output of the OU (AZ). The signal from the torque sensor (P5), which occurs in the front axle stabilizer, is added to this signal. Then the total signal is fed to the input of the phase inverter (E2). Antiphase signals from the outputs of the phase inverter (E2) are fed through the OU (A 13) and OU (A 14) to the equilibrators (EQ3) and (EQ4), in which forces are generated that compensate for the torque in the front axle. If the ATOP EQUILIBRIUM, for example the rear left (EQ3), prevents movement, for example, removal, then the sensor (P9) produces a negative potential. This signal is fed to the direct input of the OU (A 10).The signal coming from the front suspension through the phase inverter (E2) when the front left wheel hits a bump is also negative and goes to the inverted input of the op-amp (A 10). As long as the road relief allows for compensation of the front axle torque, the signals at the opposite-polarity inputs of the op-amp (A 10) and op-amp (AP) will compensate each other and there will be no signal at the op-amp output (A 12). After the vehicle has traveled a distance equal to the wheelbase, the rear left wheel will begin to move closer and compensation by the rear axle will stop, and the compensation signal will return to the front axle equalizers through the op-amp (A 12) and phase inverter (E1). To avoid roll when horizontal acceleration occurs, the control module has lateral (P6) and longitudinal (P7) acceleration sensors, which make the appropriate corrections to the ATOP AMI EQUILIBRATOR control.On vehicles with a large hull windage, it is advisable to install air pressure sensors outside the vehicle, which will introduce corrections into the EQUILIBRATORFMI control. The system also controls the position of the center of mass, and the adjustment occurs automatically during movement. The microprocessor (MPU) generates the correction signals. It compares the signals coming to the equilibrators with the signals coming from the sensors (P2; P4; P9; P11), measuring the force generated by the equilibrators. Automatic adjustment occurs each time at the moment of horizontal acceleration increase and is saved in memory (NVRAM) until the next moment of acceleration increase. This is necessary because the total mass and the position of the center of mass can change even during movement. In the operation of the damping control system in a two-axle vehicle, three main functions can be distinguished:

[0010] • Balancing the sprung mass (10) according to the weight force falling on each wheel EQUILIBRE ATOP AMI of this wheel.

[0011] • Balancing the torque acting on the sprung mass (10) from the elastic elements of one EQUILIBRE ATOP AMI axle of the other axle.

[0012] • Balancing the torque that occurs when horizontal acceleration occurs by all EQUILIBRI ATOP AMI.

[0013] The proposed damping system allows to completely eliminate resonance vibrations while completely eliminating the rigidity of the suspension. This is achieved due to a special algorithm of the system. The main advantage is that this suspension is passive. It does not require additional energy. It does not have hydraulic drives and electric drives, only power supply to the electronic unit. In addition, balancing the torque with equalizers of the other axle allows to increase the rigidity of mechanical stabilizers of transverse stability without increasing the rigidity of the suspension. Another interesting feature of such a suspension is the ability to carry the wheel over a deep hole or an open hatch without falling through. It should be noted that the suspension performs all these functions without changing the settings.

[0014] Brief description of the drawings

[0015] Fig.1 shows a simplified version of the equilibrator device.

[0016] Fig.2 shows a block diagram of the damping control system of a two-axle four-wheel vehicle with elastic anti-roll bars on each axle.

[0017] The best embodiment of the invention

[0018] The proposed damping system will suit any suspension with any springs and any elastic anti-roll bars and even without them. One of the most important parameters of the proposed damping control system is the response speed, so the best option is an analog version of the control circuit (Fig.l). The impact that the unsprung mass receives when hitting a bump in the road surface at a speed of, say, one hundred kilometers per hour, lasts from two to five milliseconds. The response speed of any digital converter is at least one and a half milliseconds, and this operation will need to be done at least twice with a digital solution. During this time, the impact will already be over. In view of this, the best option for implementing the invention is an analog version of the EQUILIBRE ATOP AMI control circuit. However, it is advisable to adjust for changes in the total mass and the position of the center of mass using a digital module.In vehicles with three or more axles, the use of such a damping system allows for complete isolation from road irregularities.

[0019] Industrial applicability

[0020] The suspension of most modern cars allows the use of the EQUILIBRE ATOP AMI damping system without changes in the suspension design. Instead of conventional hydraulic dampers, EQUILIBRATORS are installed. The reaction force sensors of the elastic elements of the stabilizers measure the vertical force in one of the hinge joints of the stabilizer with the sprung mass. In pneumatic and hydropneumatic suspensions, the spring reaction force can be measured by a pressure sensor. The horizontal acceleration sensors can be located directly in the control module. The module diagram (Fig.l) is universal and is suitable for a car of any class and any mass. When changing the mass of the vehicle, it will be necessary to change the measurement range of the force sensors and increase the range of forces generated by the EQUILIBRE ATOP AMI. It should be noted that the EQUILIBRATORS have a limited maximum force value.That is, EQUILIBRE ATOP, unlike a conventional hydraulic damper, can be used across the entire range of permissible axle loads. For example, EQUILIBRE ATOP with a piston diameter of thirty-two millimeters is suitable for use in vehicles with axle loads from a minimum of up to three tons. Such versatility simplifies the implementation of this invention. EQUILIBRE ATORS can be used in shock absorbers of machines and units.

Claims

Invention formula 1. A vehicle suspension comprising a guide device allowing the sprung mass to move relative to the unsprung mass in a vertical direction; springs; controlled damping devices; an electronic damping control system; characterized in that the damping devices used are EQUILIBRATORS in which the pressure of the fluid in the compression cavities is regulated by controlled pressure valves and the vacuum in the expansion cavities is stabilized by pressure-reducing valves.

2. The vehicle suspension according to paragraph 1, characterized in that the EQUILIBRATORS has three hydraulic cavities: one low-pressure cavity and two working cavities separated by a piston or a moving partition, and when the EQUILIBRATORS ATOP A is in operation, the piston or partition, moving in one direction, displaces the fluid from the first working cavity through a controlled pressure valve into the low-pressure cavity, and the fluid is sucked into the second working cavity through an uncontrolled pressure-reducing valve from the low-pressure cavity, and when the piston or partition moves in the other direction, the fluid is displaced from the second working cavity through a controlled pressure valve into the low-pressure cavity, and the fluid is sucked into the first working cavity from the low-pressure cavity through an uncontrolled pressure-reducing valve.

3. The vehicle suspension according to claim 1, characterized in that the damping control system measures the aerodynamic force acting on the vehicle body in a crosswind using air pressure sensors outside the vehicle and sends corresponding correction signals to the EQUI LIBRATORS.

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