SPOOL OPERATING DEVICE OF PRESSURE CONTROLLING VALVE FOR VEHICLE HYDRAULIC STEERING SERVOMECHANISM

摘要

PURPOSE: A spool operating device of a pressure controlling valve for a vehicle hydraulic steering servomechanism prevents the vibration and noise thereof by improving the structure thereof. CONSTITUTION: A female screw(21a) is formed on a spool(21) of a pressure controlling valve for operating the spool(21). A lead shaft(22a) of a step motor(22) is inserted into the spool(21), thereby moving the spool(21) by the rotational direction thereof. The step motor(22) does not have vibration in itself, but if any, the vibration is not transmitted to the spool(21) because the female screw(21a) and the lead shaft(22a) are connected by screws. Thus, oil moving from a space portion(25) of the pressure controlling valve to an outlet(24) does not cause noise.