Influence of the Length of Valve Slots on ECHPS Performance

The flow-control type electronically controlled hydraulic power steering system (hereinafter ECHPS) is the simplest form of ECHPS. To get better performance, the power steering gear should be modified. One of the modification methods is cutting short the slot of the valve. One common formula could compute the orifice size of the control valve was given and several valves with different length of slots were analyzed based on the formula. The assistance characteristics of ECHPS with these valves were calculated. At last, two steering gears with different slot length were made for experiment. The results show the assistance characteristics of the short slot valve is better than the long slot one.