Power steering device

A power steering device comprising:

• a pump for supplying a pressure fluid;
• a power cylinder having first and second chambers and driven in accordance with a pressure difference between a pressure fluid supplied to said first chamber and that to said second chamber;
• a flow channel selector valve for selectively switching a supply direction of the pressure fluid from said pump to said first and second chambers of said power cylinder in response to steering operation of a steering wheel;
• a first fluid path for connecting said flow channel selector valve and said first chamber of said power cylinder to each other;
• a second fluid path for connecting said flow channel selector valve and said second chamber of said power cylinder to each other;
• a first variable restrictor disposed in said first fluid path to control a flow rate of the pressure fluid from said power cylinder to said flow channel selector valve;
• a second variable restrictor disposed in said second fluid path to control a flow rate of the pressure fluid from said power cylinder to said flow channel selector valve;
• a first check valve connected to said first fluid path in parallel to said first variable restrictor to prevent a flow of the pressure fluid from said power cylinder to said flow channel selector valve;
• and
• a second check valve connected to said second fluid path in parallel to said second variable restrictor to prevent a flow of the pressure fluid from said power cylinder to said flow channel selector valve.