Hitachi Automotive Systems Steering, Ltd.

Hitachi, Ltd.

Unisia Jkc Steering Systems Co., Ltd.

Shogo Ishikawa

Sosuke Sunaga

Hideki Takahashi

Keisuke Kitamura

Satoru Muto

Takashi Sasaki

Toshiro Yoda

Toshihiro Arai

Toru Hasebe

A first valve accommodation hole is provided in a valve housing. A first valve element, a first valve seat member, a first coil spring, and a first pin are directly accommodated and disposed in the first valve accommodation hole. It is thereby possible to reduce the maximum diameter tof the first valve accommodation hole, thus reducing the size of a housing main body.

Integral power steering device

A fixation member is circularly formed to surround a wheel turning shaft and includes an abutment surface in abutment with an end surface of a bearing on one axial side. The fixation member fixes the bearing to a housing by being fixed in the housing with the abutment surface in abutment with the end surface of the bearing. When being mounted, the fixation member is provided by being moved from an opposite axial end side to one axial end side of the nut. The abutment surface of the fixation member is formed on at least a radially inner side of the fixation member. The fixation member includes a cutout portion provided on the radially inner side of the fixation member and formed to prevent interference with a circulation member when the fixation member is inserted in the housing.

Power steering apparatus and reduction mechanism for power steering

In a stroke-limiter equipped integral power steering apparatus, a valve body of a spring-loaded-plunger-equipped limiter valve is configured to enable a position of the valve body relative to a housing to be adjusted in a longitudinal direction of the valve body via an intermediate sleeve.

Integral power steering apparatus

A flat surface portion is formed on a nut so as to extend to a region where an output pulley attachment portion is formed in an axial direction, and extend substantially in parallel with a tangential direction of a rotational axis of the nut. A ball circulation groove one end side opening, and a ball circulation groove opposite end side opening are formed on the nut. The ball circulation groove one end side opening is in communication with one end of a ball circulation groove and is formed so as to be opened to the flat surface portion in the region where the output pulley attachment portion is formed. The ball circulation groove opposite end side opening is in communication with an opposite end of the ball circulation groove and is formed so as to be opened to the flat surface portion.

Power steering apparatus

A power steering apparatus including a power cylinder, first and second pumps, a control valve serving for selectively supplying a working fluid supplied from the first or second pump to one of a pair of pressure chambers of the power cylinder in accordance with a steering operation, first and second reservoir tanks, and a return passage changeover valve disposed between the control valve and the first and second pumps, the return passage changeover valve serving for communicating the first and second pumps with the control valve regardless of an axial position of a valve element and communicating one of the first and second reservoir tanks with the control valve in accordance with the axial position of the valve element to thereby carry out changeover between circulating fluid passages for circulating the working fluid to the first reservoir tank and the second reservoir tank.

An integral power steering apparatus includes a hydraulic actuator having a piston separating pressure chambers for steering assistance and a limiter valve to be opened by movement of the piston to fluidly connect the pressure chambers. The limiter valve includes an adjuster for adjusting a press-fit position of a spring pin press fit in a plunger. The adjuster includes a movable adjusting member formed with an abutting surface to abut against the plunger to limit rearward plunger movement when the movable adjusting member is at a first adjuster position, and a regulating member to hold the movable adjusting member at the first adjuster position at the time of adjustment, and to enable the movable adjusting member to move to a second adjuster position after adjustment.

Disclosed is a power steering system comprising: a control valve disposed in the steering mechanism to selectably supply a working liquid supplied from a first pump or a second pump to a pair of pressure chambers of a power cylinder providing a steering force for at least one steered wheel in accordance with a rotational steering operation of a steering wheel; a first switching valve disposed between the first pump and the control valve to switch a communication and an interruption of the working liquid between the first pump and the control valve; and a second switching valve disposed between the second pump and the control valve to switch the communication and the interruption of the working liquid between the second pump and the control valve, a communication state and an interruption state being selectably formed in the second switching valve when the first switching valve is in the communication state.

Power steering system

A power steering apparatus includes a steering shaft, a hydraulic power cylinder, a hydraulic pump, a steering shaft actuator, a condition sensor, and a fluid pressure controller. The steering shaft is connected to a steering wheel. The hydraulic power cylinder is mechanically linked to the steering shaft. The hydraulic power cylinder has first and second fluid pressure chambers for producing an assist steering effort. The hydraulic pump supplies a first fluid pressure to the hydraulic power cylinder. The steering shaft actuator receives a second fluid pressure from the hydraulic pump, and applies a torque to the steering shaft by the second fluid pressure. The condition sensor collects information concerning at least one of an associated host vehicle, an associated driver and an associated road. The fluid pressure controller receives the collected information from the condition sensor, and controls the steering shaft actuator based on the collected information.

Power steering apparatus, method of controlling the same and method of assembling the same

A power steering apparatus includes an input shaft, an output shaft, a piston arranged to separate a first hydraulic chamber and a second hydraulic chamber, a ball screw mechanism, an output member, a control valve configured to supply hydraulic fluid selectively to the first hydraulic chamber through a first connecting passage and to the second hydraulic chamber through a second connecting passage, a first damper valve provided in the first connecting passage, a second damper valve provided in the second connecting passage, and a housing enclosing the piston. The housing is formed with a first valve receiving hole in which the first damper valve is disposed, and a second valve receiving hole in which the second damper valve is disposed.

An integral power steering apparatus includes a stroke limiter. A piston defines two hydraulic chambers in a housing. A communicating passage, a first valve disposed between the first hydraulic chamber and the communicating passage, and a second valve disposed between the second hydraulic chamber and the communicating passage, are provided to serve for a stroke limiter, in addition to a hydraulic circuit for supplying hydraulic fluid to the two hydraulic chambers. The two valves each include a valve body having a bore and serving as a valve seat, a plunger slidably fitted within the bore of the valve body and serving as a valving element, and a spring disposed on the bottom of the bore of the valve body and biasing the plunger to be in contact with the valve body.

Growing community of inventors

Saitama, Japan

Shogo Ishikawa