Working principle of double acting cylinder shock absorber

Description of working principle of double acting cylinder shock absorber:

In the compression stroke, it refers to that the car wheels move close to the body, the shock absorber is compressed, and the piston in the shock absorber moves downward. The volume of the lower chamber of the piston decreases, the oil pressure increases, and the oil flows through the flow valve to the chamber (upper chamber) above the piston. The upper chamber is occupied by the piston rod, so the increased volume of the upper chamber is smaller than the reduced volume of the lower chamber, and part of the oil then pushes the compression valve and flows back to the storage cylinder. The oil saving of these valves forms the damping force of the compressed motion of the suspension. When the shock absorber is stretched, the wheel is away from the body, and the shock absorber is stretched. The piston of the shock absorber now moves up. When the oil pressure in the upper chamber of the piston increases, the flow valve closes, and the oil in the upper chamber pushes the expansion valve to flow into the lower chamber. Due to the existence of the piston rod, the oil flowing from the upper chamber is not enough to fill the increased volume of the lower chamber, which mainly causes a vacuum degree in the lower chamber. At this time, the oil in the oil reservoir pushes the compensation valve 7 to flow into the lower chamber for replenishment. Because of the throttling effect of these valves, the suspension has damping effect when it is in stretching motion.

Because the stiffness and pretension of the spring of the extension valve are larger than that of the compression valve, under the same pressure, the total channel load area of the extension valve and the corresponding constant clearance is smaller than that of the compression valve and the corresponding constant clearance. This makes the damping force produced by the extension stroke of the shock absorber larger than that of the compression stroke, so as to meet the requirements of rapid shock absorption.