Abstract: A cap which is so constructed that parts manufacture and product assembly are facilitated. The construction is such that a cap for a master cylinder reservoir connects a cover cap and a body cap with each other and a diaphragm is disposed in a space formed therebetween to provide a valve function. The cover cap has a concentric cylindrical portion and an annular protrusion, while the body cap has a funnel portion at its center and an annular disc portion at the periphery of the funnel portion. The diaphragm is fitted between the inner periphery of annular protrusion of the cover cap and the outer periphery of the funnel portion of the body cap. The diaphragm forms a suction valve and an exhaust valve together with the cylindrical portion and the annular disc portion, respectively.

Abstract: In a control method of an electric power steering apparatus for a vehicle, a target value generator for setting a target value of a steering force or a motor output and a primary delay system with a variable damper value according to a vehicle speed are arranged in a control unit, and an electric power steering unit is controlled using a value obtained by filtering a difference between the target value set by the target value generator and an actual value through the primary delay system.

Abstract: A power steering device including a vane type oil pump having vanes which are radially movable in slits of a rotor to supply hydraulic fluid from an oil reservoir tank to a power cylinder through a flow passage switching valve. Chambers are defined behind the valves at base ends of the slits. Hydraulic fluid having a pressure built up by the reciprocal motion of the valves in the chambers is supplied through a solenoid coil type flow control valve to hydraulic reaction force chambers of a power cylinder control valve to thereby control a force applied between input and output shafts thereof, thereby to determine the steering force required.

Abstract: A waterproof seal ring, to be fitted between the contacting surfaces of a master cylinder body and the front wall of a power booster housing surrounding a bulge of the housing through which a push rod is inserted and having a downwardly extended passage groove formed in the lower part of the wall, has a circumferential vent groove formed on the pressure-contact side of the ring. The vent groove is communicated at the lower end with the passage groove in the front wall of the booster housing and at the upper end with the space inside the bulge.