Abstract: A hydraulic pressure control valve includes a valve body having a slide bore with a circular cross-section, an inlet port opened in an inner surface of the slide bore, a control pressure port and an outlet port at axially spaced-apart distances in this sequence; a valve spool axially slidably fitted in the valve body; and a first variable orifice and a second variable orifice both formed between the valve body and the valve spool. The first variable orifice controls the degree of communication between the inlet port and the control pressure port, and the second variable orifice controls the degree of communication between the control pressure port and the outlet port. In this hydraulic pressure control valve, the valve spool has smaller diameter portions coaxially formed therein to define annular oil passages between the inner surface of the slide bore and the valve spool and each smaller diameter portion has an outer diameter set uniformly over the axially entire length thereof.

Abstract: A hydraulic pressure control valve comprises a valve body having a slide bore of a circular cross-section and an inlet port and an outlet port opened into an inner surface of the slide bore at axially spaced apart points, and a valve spool slidably received in the valve body for axially sliding movement and defining, by cooperation with the valve body, a variable orifice for controlling the degree of communication between the inlet and outlet ports. In the hydraulic pressure control valve, a smaller diameter portion defining an annular oil passage between an inner surface of the slide bore is provided on the valve spool coaxially with the slide bore to define the variable orifice, and has an outside diameter set constant over axially entire length. This facilitates the dimensional control of the variable orifice, so that the variation in property of the variable orifice for every hydraulic pressure control valve may be easily suppressed.

Abstract: A power steering device for vehicles having a simple construction, which is capable of minimizing the frictional loss of a hydraulic pump as well as the power consumption of the hydraulic pump and engine.

Abstract: An improved power steering device which has a pinion shaft connected with a steering wheel, a rack rod which is connected with steerable wheels and whose rack is in mesh with the pinion of the pinion shaft in the gear box, a power cylinder for hydraulically actuating the rack rod, and a changeover valve for selectively connecting the first and second hydraulic chambers of the power cylinder with the hydraulic pressure source and the oil reservoir. The pinion shaft is rotatably supported in the oscillating cage which is rotatably mounted on the gear box in a manner such that the axis of the oscillating cage is offset a certain distance from the axis of the pinion shaft, whereby the oscillating cage rotates about its axis when the steering torque is applied to the pinion shaft. The oscillating cage is connected with the changeover valve so that the latter is actuated by the rotary movement of the oscillating cage.

Abstract: A steering mechanism for vehicle equipped with a power steering system, the steering mechanism including a resilient element, such as a torsion bar, which is interposed in a path of torque transmission between a steering wheel and a power steering unit which provides an increased steering reactive force in proportion to vehicle speed. The steering mechanism includes a damper arrangement disposed between two relatively rotatable members which are operably associated with each other through the resilient element. The damper arrangement attenuates torsional vibrations of a first one of the relatively rotatable members disposed on the side of the steering wheel, such vibrations being caused by the interposed resilient element and the moment of inertia of the steering wheel.

Abstract: An improved power steering device which has a pinion shaft connected with a steering wheel, a rack rod which is connected with steerable wheels and whose rack is in mesh with the pinion of the pinion shaft in the gear box, a power cylinder for hydraulically actuating the rack rod, and a changeover valve for selectively connecting the first and second hydraulic chambers of the power cylinder with the hydraulic pressure source and the oil reservoir. The pinion shaft is rotatably supported in the oscillating cage which is rotatably mounted on the gear box in a manner such that the axis of the oscillating cage is offset a certain distance from the axis of the pinion shaft, whereby the oscillating cage rotates about its axis when the steering torque is applied to the pinion shaft. The oscillating cage is connected with the changeover valve so that the latter is actuated by the rotary movement of the oscillating cage.

Abstract: A device including a torsion bar rotatably mounted on the vehicle frame transversely thereof and a pair of rock arms extending integrally from the opposite ends of the torsion bar at right angles thereto and connected with a right and a left wheel, respectively. An abutment arm is fixed to the torsion bar at the middle thereof and engageable with a stop pad provided on the vehicle frame, when either or both of the wheels are moved down, to restrain further downward movement thereof. Thus, the spring rate of air springs associated with the respective wheels is in effect increased as the loads thereon are reduced, particularly in a lower load region.