Abstract: A wheel motor drive system for electric automobiles comprises a car battery mounted on a vehicle body, at least two electric motors connected to vehicle wheels independently of each other, each of the motors having inherent torque characteristics with regard to a rotational speed and a maximum torque, sensors for monitoring a vehicle travelling condition, and a controller responsive to the vehicle travelling condition and the torque characteristics of the motors for controlling the motors at a low power consumption mode wherein at least one of the motors is driven within a high motor efficiency range so as to assure a long travel distance per one battery discharge.

Abstract: A switchable connection for a plurality of unit batteries for an electric vehicle. The unit batteries are normally connected in series through battery switches. When an impact sensor attached to a vehicle body detects an impact, a controller changes the battery switches to have a connecting state in which the unit batteries are separated into several groups.

Abstract: An electric vehicle driven by a motor is provided with a secondary battery and a generator which are controlled by a controller so that when an amount of charge of the secondary battery becomes lower than a predetermined value of the generator is put from a stopping state into an operating state and so that when the amount of charge of the secondary battery becomes higher than another predetermined value the generator is put from the operating state into the stopping state. The controller changes the predetermined values in accordance with the changing rate of the electric energy consumption of the secondary battery so that the secondary battery loses it amount of charge after the generator becomes empty of its fuel. The electric vehicle can fully perform its characteristic and the generator is effectively operated by storing excessive electric energy of the generator and effectively using the secondary battery.

Abstract: In an electric vehicle driven by an electric motor, a battery accumulator supplies electricity to the electric motor and a plurality of auxiliaries. A generating unit generates electricity in order to charge the battery accumulator. A detector unit detects at least one of various running conditions of the vehicle. A control unit supplies the electricity from the generating unit directly to the electric motor when the detected running condition indicates an overload condition, and gradually reduces the electricity supplied to the auxiliaries.

Abstract: Two torque sensors (201, 202) are arranged for detecting the steering force which is added to the motor-driven power steering apparatus. One torque sensor is selected by the command signal from the micro computer (80), for controlling the auxiliary steering force from the motor-driven actuator (5) by the command signal from the micro computer (80).

Abstract: A vehicular power steering system is provided with a steering effort control system which controls the degree of power assistance by controlling the supply of hydraulic fluid to the hydraulic power actuator unit. The steering effort control system monitors the speed of the vehicle and the angular velocity of the steering wheel, and controls the quantity of the fluid supply in accordance with the monitored variables. The fluid supply quantity is determined so as to satisfy the following three conditions: (1) The steering must become heavier as the vehicle speed increases; (2) however, a sufficient amount of the fluid must be supplied even when the steering wheel is turned rapidly; and (3) the driver must be given a feel about the lateral acceleration of the vehicle during a turn.

Abstract: A steering pressure control apparatus for a power-assisted steering system for a vehicle including a steering power cylinder to develop a steering assistance fluid pressure, comprising a detecting unit operative to detect a state in which the steering wheel is held in an angular position turned from the straight-ahead position thereof through an angle smaller than a predetermined value and to produce an output signal when the that predetermined state is detected; and a control unit responsive to the output signal from the detecting unit and operative to control the steering assistance fluid pressure to be developed in the steering power cylinder so that the steering assistance fluid pressure is lower or higher in the presence of the signal than in the absence of the signal.

Abstract: A steering control apparatus for a power-assisted vehicle steering system for a vehicle, comprising a steering pressure pump, a power cylinder, a pressure control valve operative to direct fluid under pressure from the pump to the power cylinder to develop in the cylinder a differential fluid pressure to produce a controlled degree of hydraulic steering assistance, and a fluid flow control valve bypassing the pressure control valve between the suction and delivery ports of the pump, wherein the differential fluid pressure to be developed in the power cylinder or the flow rate of the fluid to be discharged through the flow control valve is variable in two or more different basic modes in each of which the differential fluid pressure or the fluid flow rate is further continuously variable so that the vehicle driver is enabled to steer the vehicle with a manual steering effort continuously variable with, for example, the vehicle speed.

Abstract: In a vehicular power steering system, the hydraulic fluid supply to a hydraulic power actuator is controlled in accordance with the vehicle speed and the angular velocity of the steering wheel. Preferably, the fluid supply is reduced so that the steering effort becomes heavier as the vehicle speed increases while the fluid supply is increased when the angular velocity of the steering wheel is high. To control the fluid supply, there is provided, in a power steering system, a bypass valve means for draining a portion of the fluid flow to bypass the power actuator, and control means for producing a control signal to control the bypass valve means in accordance with the vehicle speed and the angular velocity of the steering wheel.

Abstract: A control apparatus for a power-assisted steering system, comprising a power cylinder having pressure acting chambers respectively communicating with the control ports of a pressure control valve having inlet and outlet ports respectively communicable with the delivery and suction ports of a pump, and first and second flow control valves each having an inlet port and a discharge port communicating with the suction port of the pump, each flow control valve including a control pressure acting chamber communicating with a pressure acting chamber of the power cylinder to develop a differential pressure variable with a differential pressure between the pressure acting chambers of the cylinder, and a valve member movable in response to the differential pressure acting thereon and urged to provide communication between the inlet and discharge ports of each flow control valve, the inlet port of the first flow control valve being in constant communication with the delivery port of the pump and the inlet port of the pr

Abstract: A control apparatus for a power-assisted vehicle steering system, comprising a power cylinder having two pressure-acting chambers, a control valve having inlet and outlet ports respectively communicable with a pump and a fluid reservoir and selectively with the inlet and outlet ports, a pressure compensating valve having an inlet port communicating with the pressure-acting chambers, outlet and control ports and a valve member for varying the degree of communication between the inlet and outlet ports, the fluid pressure in the inlet port being variable with the fluid pressure from the pump and urging the valve member to move in one direction and a spring urging the valve member to move in the other direction to maintain constant the differential pressure between the inlet and outlet ports, and a pressure reducing valve having an inlet port communicating with the outlet port of the compensating valve, a discharge port communicating with the reservoir and the control port of the compensating valve and a valve me