摘要:
A “brake-by wire” brake system for motor vehicles, with a brake master cylinder which can be actuated by a brake pedal and has a housing and a piston, which is arranged displaceably in the housing and, together with the housing, delimits a pressure space. The piston of the brake master cylinder is designed as a stepped piston with at least two hydraulic active surfaces A1, A2 of differing size, wherein a first, small active surface A1 is assigned to the pressure space, and a second, large active surface A2 is assigned to a filling space, and, after a closing travel has been overcome, the second, large hydraulic active surface A2 is effective and the active surface A2, A1 are switched over in dependence on a hydraulic pressure in the pressure space and on the pedal force, respectively.
摘要:
An electronically controlled boosted brake system including an isolation valve between a source of pressurized fluid and a boost valve for selectively restricting the flow of fluid from the source to the boost valve. Another feature of the brake system relates to an accumulator valve connected between the boost valve and the accumulator for controlling when the operating pressure of the accumulator is supplied to the boost valve. Yet another feature is a unique master cylinder design including at least one primary piston positioned within a housing in an overlapping relationship with portions of a pair of secondary pistons.
摘要:
A hydraulic device for actuating the braking of work vehicles and the like, comprising a duct for connecting the delivery duct to the discharge duct or to an auxiliary duct, along which there are auxiliary pumping elements, which can be actuated in order to pump pressurized liquid into the feed duct; a one-way valve being provided which allow the liquid to flow along the connecting duct exclusively toward the delivery duct.
摘要:
A brake system for a motor vehicle includes a master brake cylinder in which a primary piston for generating a brake pressure in a hydraulic brake circuit can be displaced according to actuation of a brake pedal. It is possible to displace the primary piston under the effect of a hydraulic servo pressure circuit in the master brake cylinder. The hydraulic servo pressure circuit includes a pressure source for generating the servo pressure and a pressure accumulator for maintaining a minimum servo pressure in the servo pressure circuit, wherein the discharge line is constructed with a non-return valve which only allows discharge of hydraulic fluid from the pressure accumulator into the servo pressure circuit. A pressure sensor for detecting the hydraulic pressure prevailing in the pressure accumulator is associated with the pressure accumulator.
摘要:
The invention relates to a brake system for a motor vehicle comprising a master brake cylinder in which a primary piston for generating a brake pressure in a hydraulic brake circuit can be displaced according to actuation of a brake pedal, it being possible to displace the primary piston under the effect of a hydraulic servo pressure circuit in the master brake cylinder and the hydraulic servo pressure circuit comprising a pressure source for generating the servo pressure and a pressure accumulator for maintaining a minimum servo pressure in the servo pressure circuit. It is provided in this brake system that the pressure accumulator of the servo pressure circuit can be supplied with hydraulic fluid as a function of the servo pressure prevailing in the servo pressure circuit.
摘要:
A bellows-type hydraulic accumulator includes a shell, a bellows unit, and a stay in order to accumulate pressurized liquid within a liquid chamber, divided into a fixed-volume liquid chamber and a variable-volume liquid chamber communicating with the fixed-volume liquid chamber via a communication port formed in the stay. A pipe is inserted into a liquid inlet/outlet port communicating with the fixed-volume liquid chamber, to thereby form an inflow passage inside the pipe and an outflow passage outside the pipe. A tip end of the pipe is located within the communication port of the stay with a predetermined radial clearance formed between the tip end and a wall surface of the communication port, to thereby enable pressurized liquid to be supplied to the variable-volume liquid chamber from the tip end of the pipe and to be discharged from the variable-volume liquid chamber to the fixed-volume liquid chamber via the radial clearance.
摘要:
The present disclosure relates to a pump system for parking brakes for a rail vehicle. The pump system includes at least one actuator, at least one pump and a reservoir as a fluid source. Also included is a manifold in fluid communication with the reservoir and the actuator. Further included are a plurality of valves and fluid paths internal to the manifold to allow fluid flow among the at least one pump and the reservoir.
摘要:
A vehicle hydraulic brake system includes a hydraulic pressure generator which pressurizes brake fluid supplied from a reservoir to apply brake pressure to a wheel cylinder in response to operation of a brake member, an auxiliary hydraulic pressure source having an accumulator and a hydraulic pump that pressurizes brake fluid supplied from the reservoir to a predetermined level for generating power hydraulic pressure, and an output hydraulic pressure detector for continuously detecting an output hydraulic pressure of the accumulator. A vehicle condition detector continuously detects an operating condition of the vehicle and a driving condition setting device sets a driving condition of the hydraulic pump based on the detected operating condition of the vehicle. A driving control device controls the hydraulic pump based on the driving condition of the hydraulic pump set by the driving condition setting device and the output hydraulic pressure of the accumulator.
摘要:
A fluid pressure source apparatus includes a pump, an accumulator for receiving pressure from the pump, a pressure switch for detecting the pressure in the accumulator, an electric motor for driving the pump, and a motor control device for driving the motor when the pressure switch detects a low pressure. A current detecting device detects a motor current value of the motor and a control unit determines whether the accumulator or the motor is experiencing an abnormality based on the motor current value. The control unit determines whether the motor current value occurring during a first set time following the start of driving of the motor is greater than a first set value. If the motor current value is not greater than the first set value, the control unit determines that the current detecting device is experiencing an abnormality. If there is no such abnormality information, the control unit compares the motor current value with predetermined values. If the motor current value continues to be less than a lower limit value for at least a predetermined length of time, the control unit determines that there is a low pressure abnormality. If the motor current value continues to be greater than an upper limit value for at least a predetermined length of time, the control unit determines that there is a motor lock abnormality.
摘要:
A wheel brake pressure supplying device for supplying fluid pressure for a wheel brake cylinder of a wheel on an automotive vehicle includes a reservoir, a pump, a motor, an accumulator connected to the wheel brake cylinder, a fluid pressure sensor, an electric source, an operation time determining device and a motor control device. The reservoir stores a fluid and the pump is connected to the reservoir for pumping fluid in the reservoir. The motor operates the pump and the accumulator is connected to the pump for storing the fluid pumped by the pump so that fluid pressure in the accumulator increases through operation of the pump. The fluid pressure sensor senses when the fluid pressure in the accumulator is less than a predetermined pressure. The electric source is connected to the motor for supplying voltage to the motor and the operation time determining device determines a target operation time of the motor based on the voltage of the electric source. The motor control device starts the operation of the motor when the fluid pressure in the accumulator is less than the predetermined pressure and terminates the operation of the motor when the operation time of the motor reaches the target operation time.