FLOW CONTROL DEVICE IN POWER-DRIVEN STEERING DEVICE

摘要

PURPOSE:To enable the flow characteristic to be easily set up by forming, in a spool valve member, a fixed orifice and a variable orifice whose throttle area is decreased when the spool valve member is displaced by a predetermined distance. CONSTITUTION:An axially slidable spool valve 21 is inserted in a valve housing 20 and is energized to the left by a spring 22. The spool valve 21 is formed with a cylindrical part 21a and a cylindrical pin 30 of a plug 29 screwed into the valve housing 20 is fitted into said cylindrical part. The spool valve 21 is slid to the right when a high pressure is applied from a supply passage 23 so that the supply passage 23 is communicated with a discharge passage 24 through a by- pass 25 and as well the throttle area of a variable orifice 34 is decreased. A fixed orifice 36 which delivers pressure oil from the supply passage 23 to a PS is formed in said fixed plug 29.