Novel Hydro-Pneumatic Interconnected Suspension Integrating Pipe-Connected Magnetorheological Valve Designed Based on Magnetic Gradient Pinch Mode—Experimental Study and Modelling

Recently, passive Hydro-pneumatic Interconnected Suspension (HIS) has been utilized in commercial vehicles due to its outstanding handling performance. However, it cannot satisfy the working requirement over the whole working frequency range due to the fixed damping property. In order to provide the continuously tunable damping and satisfy the large flow rate requirement of HIS device, a novel HIS integrating pipe-connected Magnetorheological valve (MGPMR valve) designed based on Magnetic Gradient Pinch Mode, is proposed in this study. The designed MGPMR valve is suitable for the large flow rate working condition of HIS system together with the stackable property through series connection of number of MGPMR valves to achieve the required damping properties. Based on the designed experimental, it has been shown that the designed pipe-connected single MGPMR valve can reach 735% tunable range of the damping property under 1.234×10^–4 m³/s sinusoidal flow rate signal. The dynamic property of the novel HIS is described by the established model considering the ideal gas law with Energy Equation, fluid inertial and laminar flow between the connection pipes, and piston frictions, together with pressure drop property of MGPMR valve described by the hyperbolic tangent hysteresis model, and the validity of the dynamic model is verified by the laboratory test. Finally, based on a roll-plane vehicle simulation model, the effect of the tunable damping property for the novel HIS is evaluated based on the frequency domain analysis and responses under the road transient and lateral acceleration excitations. The results show that compared with the traditional HIS (without MGPMR valve), the vertical/roll vibration isolating properties and anti-roll performance of the vehicle model can be improved through modifying the applied current of pipe-connected MGPMR valves, which provides the application potential to achieve continuously tunable damping in the semi-active HIS design.