摘要:
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.
摘要:
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.
摘要:
A power steering device includes a hydraulic pump for discharging working fluid, an actuator for producing a steering assisting force by means of working fluid, a hydraulic passage for connecting the hydraulic pump and the actuator, a check valve arranged to the hydraulic passage to allow flow of working fluid from the hydraulic pump to the actuator and preventing flow thereof in the opposite direction, an accumulator connected to the hydraulic passage downstream of the check valve, a pressure switch for detecting a pressure within the hydraulic passage downstream of the check valve, a control unit for controlling the hydraulic pump in response to the pressure switch, and a display for showing an anomaly of the power steering device. When determining the anomaly of the power steering device, the control unit stops the hydraulic pump and/or makes the display show the anomaly.
摘要:
A power assisted steering apparatus for a vehicle having a driving source, such as an engine, has an actuator, a hydraulic pump, a working oil pressure passage, and a drive switch. The actuator, which is in the vehicle steering mechanism, receives a supply or exhaust of a working oil to assist the steering operation. The pump is selectively driven by an engine via a clutch mechanism. The working oil discharged from the pump is introduced into the actuator via the passage. The check valve is interposed within the passage to enable flow in one direction away from the pump. The drive switch structure is disposed within the passage, downstream from the check valve. With this arrangement, the drive switch structure can be activated by pressure in the passage downstream of the check valve to control the clutch mechanism.
摘要:
A power steering system includes a fluid pump, a steering gear, a high-pressure passage connecting the fluid pump to the steering gear, and a flow control valve having a first chamber forming a part of the high-pressure passage. A metering orifice is disposed in the high-pressure passage between the first chamber and the steering gear. A feedback passage distributes feedback pressure developed in the high-pressure passage downstream of the metering orifice to a second chamber of the flow control valve. An exhaust port communicates with the first chamber. A movable valve spool is disposed in a valve bore and has one end exposed to the first chamber and opposite end exposed to the second chamber. A valve spring is disposed in the second chamber together with a slide coupled with an external actuator. One end of the valve spring is seated on the opposite end of the valve spool and opposite end thereof is seated on the slide. The actuator is responsive to a control signal to position the slide thereby varying force with which the valve spring urges the valve spool. A control unit develops the control signal in response to turning maneuvers.
摘要:
A steering power assist apparatus is comprised of a power cylinder whose operation is controlled by the a flow rate control valve, a first control valve and a second control valve. The flow rate control valve is connected to a discharge side of a hydraulic pump and controls the amount of the hydraulic oil to be supplied to the first and second control valves according to a load pressure. The first control valve constituted by choke valves is disposed downstream of the flow rate control valve and controls the amount of the hydraulic oil supplied to the second control valve according to a steering torque. The second control valve constituted by choke valves is disposed downstream of the flow rate control valve and controls the amount of the hydraulic oil to the power cylinder according to a steering torque. The choke valves of the second control valve are fully closed after the choke valves of the first control valve are fully closed.
摘要:
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.
摘要:
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.
摘要:
A power assisted steering apparatus for a vehicle has a driving source and an actuator for the vehicle's steering mechanism, to power assist the steering operation. The driving source, such as an engine, continuously drives a pump. A working passage is arranged so that working oil discharged from the pump is introduced into the actuator. A check valve is disposed in the working passage, between the actuator and the pump so that the working oil flows only one way to the actuator. An accumulator is connected to the working passage, between the check valve and the actuator to maintain a predetermined pressure in the working passage. A regulator is connected to the working passage, between the pump and the check valve to regulate flow to the actuator. When the pressure within the working passage reaches the predetermined pressure, the working fluid is dumped to a reservoir, bypassing the check valve, the accumulator, and the actuator.
摘要:
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.