Abstract: A steering device includes an electric actuator that applies a steering force to one end side of a steering shaft. The other end side of the steering shaft is provided with a displacement detection part for detecting the movement amount of the steering shaft. Either a detection target or a displacement detection sensor is provided on the steering shaft and the other is provided in a housing so as to output a signal according to a relative position change amount of the detection target with respect to the displacement detection sensor in the direction of the first axis. A first restriction mechanism restricts the relative movement of the detection target and the displacement detection sensor in a radial direction regarding the first axis to limit the change in the relative position in the radial direction of the detection target and the displacement detection sensor.

Abstract: A steering device includes an electric actuator that applies a steering force to one end side of a steering shaft. The other end side of the steering shaft is provided with a displacement detection part for detecting the movement amount of the steering shaft. Either a detection target or a displacement detection sensor is provided on the steering shaft and the other is provided in a housing so as to output a signal according to a relative position change amount of the detection target with respect to the displacement detection sensor in the direction of the first axis. A first restriction mechanism restricts the relative movement of the detection target and the displacement detection sensor in a radial direction regarding the first axis to limit the change in the relative position in the radial direction of the detection target and the displacement detection sensor.

Abstract: A hydraulic pressure control apparatus has an electromagnetic valve having a valve body forced to one side by an elastic member and a coil driving the valve body to the other side; a hydraulic pressure control section for calculating a command current value to drive the electromagnetic valve and controlling a hydraulic pressure in a hydraulic circuit by opening/closing the electromagnetic valve; a current detection section detecting a value of the current passing through the coil; and a command current value correction section. The command current value correction section detects a change of an inductance of the coil when the valve body moves from the one side to the other side or from the other side to the one side through the current detection section, and corrects the command current value using the detected inductance change.

Abstract: A pump apparatus including a discharge valve including a case member, a valve body within the case member, a seat member having a concaved valve seat, a retainer serving to retain the valve body on the valve seat on a side of one end of the retainer, an elastic member disposed on a side of the other end of the retainer, the elastic member serving to apply a biasing force to the valve body toward the seat member, and a guide portion formed on the retainer, the guide portion serving to guide the retainer relative to the case member when the valve body is moved to an open position, the guide portion being disposed on a radial outside of the elastic member or a radial inside thereof and overlapped with the elastic member in an axial direction thereof.

Abstract: A solenoid valve includes a solenoid coil, a yoke of magnetic material, an armature of magnetic material to move in an axial direction of the solenoid coil when the solenoid coil is energized, a plunger to be moved with the armature, a valve seat member including a seat portion formed with a valve hole to be closed and opened by a forward end portion of the plunger, and a coil spring which is disposed between a spring receiving portion of the plunger and the valve seat member, around the plunger. The plunger includes a pressure receiving portion (such as a flat portion) which extends in a radial direction of the plunger at a position between the forward end portion and the spring receiving portion of the plunger, and which faces to the seat portion.

Abstract: A hydraulic pressure control apparatus has an electromagnetic valve having a valve body forced to one side by an elastic member and a coil driving the valve body to the other side; a hydraulic pressure control section for calculating a command current value to drive the electromagnetic valve and controlling a hydraulic pressure in a hydraulic circuit by opening/closing the electromagnetic valve; a current detection section detecting a value of the current passing through the coil; and a command current value correction section. The command current value correction section detects a change of an inductance of the coil when the valve body moves from the one side to the other side or from the other side to the one side through the current detection section, and corrects the command current value using the detected inductance change.

Abstract: A solenoid valve includes a solenoid coil to produce a magnetic field when energized, a yoke of magnetic material encasing the solenoid coil, an armature of magnetic material surrounded by the yoke, and arranged to move in an axial direction of the solenoid coil when the solenoid coil is energized, a plunger to be moved with the armature, a valve seat member including a seat portion formed with a valve hole to be closed and opened by a forward end portion of the plunger, and a coil spring which is disposed between a spring receiving portion of the plunger and the valve seat member, around the plunger, and which is arranged to urge the plunger toward a normal position. The plunger includes a pressure receiving portion (such as a flat portion) which extends in a radial direction of the plunger at a position between the forward end portion and the spring receiving portion of the plunger, and which faces to the seat portion.

Abstract: In a power steering device employing a hydraulic power cylinder, a motor-driven pump, and a driving power source for the motor, a power steering control system is configured to electrically connected to at least the motor and the power source for controlling a driving state of the motor and a power source voltage of the power source. The power steering control system includes a motor control circuit that generates a motor driving signal, whose command signal value is determined based on a steering assist force applied through the power cylinder to steered road wheels, a booster circuit that boosts the power source voltage, a motor angular acceleration detection circuit that detects or estimates a motor angular acceleration, and a booster-circuit control circuit that controls, responsively to the motor angular acceleration, switching between operating and non-operating states of the booster circuit.

Abstract: A brake control apparatus including a reservoir tank, a housing, a pump within the housing, a suction port formed in the housing and communicated with a suction portion of the pump, a discharge port formed in the housing and communicating a discharge portion of the pump with wheel cylinders, a suction pipe connecting the suction port and the reservoir tank, and a reservoir chamber disposed within the housing between the suction portion of the pump and the suction port. The reservoir chamber has a volume capable of reserving at least a predetermined amount of the brake fluid which is required for one-time braking at a maximum fluid pressure.

Abstract: A power steering apparatus includes a hydraulic power cylinder, a reversible pump including a first outlet connected with a first pressure chamber of the power cylinder through a first fluid passage, and a second outlet connected with a second pressure chamber of the power cylinder through a second fluid passage, and a motor for driving the pump. A controller controls the motor in accordance with a sensed steering force. There is further provided a connection passage connecting the first and second fluid passages together, and a closing valve disposed in the connection passage. The controller sends a first current to a coil of the valve to close the connection passage by moving an armature, to send a second current lower than the first current to the coil after the connection passage is closed, and to deenergize the coil to open the connection passage.

Abstract: A first fluid passage extends from a first outlet/inlet port of a hydraulic pump to a first work chamber of a power cylinder, and a second fluid passage extends from a second outlet/inlet port of the pump to a second work chamber of the power cylinder. A switch system switches the role of the first and second outlet/inlet ports in accordance with a turning direction of a steering wheel. Flow control mechanisms are respectively incorporated with the first and second fluid passages, so that a controlled flow of hydraulic fluid from the hydraulic pump to the first or second work chamber and vice versa are appropriately carried out thereby providing the driver with a comfortable steering feeling. A bypass arrangement may be provided between the first and second fluid passages to deal with a residual pressure that would be remained in the first or second work chamber when the hydraulic pump is under inoperative condition.

Abstract: A steering system includes a hydraulic power cylinder 5 that assists a steering force of a rack-and-pinion mechanism 4, and a first hydraulic pressure supply mechanism 8 having a first trochoid pump 23 selectively supplying hydraulic pressure to two hydraulic pressure chambers 15a and 15b of the hydraulic power cylinder via first and second fluid passages 6 and 7, and a first electric motor 24 for the first trochoid pump. When the first hydraulic pressure supply mechanism becomes failed, a second hydraulic pressure supply mechanism 11 is operated responsively to a command signal from a control unit 14 to selectively supply hydraulic pressure via third and fourth fluid passages to either one of the hydraulic pressure chambers. Thus, it is possible to positively apply a steering assist force by means of the second hydraulic pressure supply mechanism 11, thereby reducing a driver's operating force applied to a steering wheel.

Abstract: In a power steering system employing a power cylinder for steering assistance, hydraulic pressure is supplied through a pair of fluid lines to respective hydraulic chambers of the power cylinder. Check valves are provided to charge a hydraulic pressure in a communicating circuit intercommunicating the two fluid lines. Also provided is a solenoid-actuated directional control valve for relieving the hydraulic pressure charged in presence of a power steering system failure. An opening of the directional control valve varies depending on a solenoid attracting force and a pressure differential between the hydraulic pressure in the communicating circuit and hydraulic pressure in a reservoir. A relatively low exciting current is applied to the solenoid when the hydraulic pressure charged exceeds a predetermined pressure value. A relatively high exciting current is applied to the solenoid when the hydraulic pressure charged is less than or equal to the predetermined pressure value.

Abstract: A power assist mechanism is provided that assists operation of a steering mechanism when receiving a pressurized hydraulic fluid. A hydraulic pump feeds the power assist mechanism with the pressurized hydraulic fluid when driven. An electric motor drives the hydraulic pump. A battery unit is provided for energizing the electric motor. A control unit is provided for controlling the electric power from the battery unit to the electric motor. The battery unit comprises a plurality of lead-acid batteries that are connected in series. Each lead-acid battery comprises a spirally wound positive plate, a spirally wound negative plate, a spirally wound insulating plate that is spirally wound and sandwiched between the positive and negative plates, a battery case that puts therein the spirally wound positive, negative and insulating plates and an electrolyte that is provided in the battery case.

Abstract: In a power steering device employing a hydraulic power cylinder, a motor-driven pump, and a driving power source for the motor, a power steering control system is configured to electrically connected to at least the motor and the power source for controlling a driving state of the motor and a power source voltage of the power source. The power steering control system includes a motor control circuit that generates a motor driving signal, whose command signal value is determined based on a steering assist force applied through the power cylinder to steered road wheels, a booster circuit that boosts the power source voltage, a motor angular acceleration detection circuit that detects or estimates a motor angular acceleration, and a booster-circuit control circuit that controls, responsively to the motor angular acceleration, switching between operating and non-operating states of the booster circuit.

Abstract: In a hydraulic power steering system employing a power cylinder accommodating therein a piston connected to a steering mechanism for steering assistance, and having first and second hydraulic chambers defined on both sides of the piston, hydraulic pressure is supplied through first and second fluid lines to the respective hydraulic chambers. A communicating circuit is provided to intercommunicate the first and second fluid lines therevia. A directional control valve, disposed in the communicating circuit, has a poppet valve mechanism, which is switched to a valve-open position in presence of a hydraulic power steering system failure, to intercommunicate the first and second fluid lines with the poppet valve mechanism opened.

Abstract: A power steering apparatus includes a hydraulic power cylinder, and a reversible pump driven by a motor. A steering assist sensor senses a steering assist force provided to a steering wheel. A controller ascertains a pump discharge quantity of the reversible pump, and a cylinder volume variation of the pressure chambers of the hydraulic power cylinder; and calculates a leak quantity of the reversible pump from a difference between the pump discharge quantity and the cylinder volume variation. The controller controls the motor to cause the motor to produce a desired fluid pressure in accordance with the steering assist force and the leak quantity.

Abstract: A power steering system for a vehicle. The system includes a hydraulic power cylinder, first and second hydraulic lines, a bypass passage through which the first and second hydraulic lines are connected with each other, and a flow passage change-over device adapted to close the bypass passage during steering assisting. A supply passage and a return passage are disposed in parallel with each other to form part of each of the first and second hydraulic lines. The flow passage change-over device is disposed in each of the first and second hydraulic lines. A differential pressure regulating valve is disposed in each of the return passages and adapted to allow hydraulic fluid to flow toward the hydraulic pressure source in a condition where pressure on side of the hydraulic power cylinder becomes higher than a set pressure or higher than pressure on side of the hydraulic pressure source.

Abstract: A power steering apparatus includes a hydraulic power cylinder, a reversible pump including a first outlet connected with a first pressure chamber of the power cylinder through a first fluid passage, and a second outlet connected with a second pressure chamber of the power cylinder through a second fluid passage, and a motor for driving the pump. A controller controls the motor in accordance with a sensed steering force. There is further provided a connection passage connecting the first and second fluid passages together, and a closing valve disposed in the connection passage. The controller sends a first current to a coil of the valve to close the connection passage by moving an armature, to send a second current lower than the first current to the coil after the connection passage is closed, and to deenergize the coil to open the connection passage.

Abstract: A power steering apparatus includes a hydraulic power cylinder, and a reversible pump driven by a motor. A steering assist sensor senses a steering assist force provided to a steering wheel. A controller ascertains a pump discharge quantity of the reversible pump, and a cylinder volume variation of the pressure chambers of the hydraulic power cylinder; and calculates a leak quantity of the reversible pump from a difference between the pump discharge quantity and the cylinder volume variation. The controller controls the motor to cause the motor to produce a desired fluid pressure in accordance with the steering assist force and the leak quantity.