摘要:
Hydraulic pressure control apparatus wherein a pressure difference across a seating valve disposed in a fluid passage acts on a valve member for placing the seating valve in an open state, while an elastic member biases the valve member for placing the seating valve in a closed state, and a valve driving device operated with an electric current applied thereto generates a drive force acting on the valve member so as to open the seating valve. A control device for controlling the electric current includes a stepping controller for incrementing the amount of the electric current when the seating valve is operated from the closed state into the open state, such that an increment of the electric current decreases with an increase in the pressure difference. The hydraulic pressure control apparatus may be suitably used in a vehicle braking system, for controlling fluid pressure in wheel brake cylinder.
摘要:
A brake apparatus for an electric vehicle which maintains the regenerative energy generated in a traction motor of each of wheels to be at a maximum. A hydraulic pressure brake and a regenerative brake are provided in the same brake apparatus. The hydraulic pressure brake generates a brake torque by providing a hydraulic pressure to a wheel cylinder of each wheel of the vehicle. The regenerative brake generates a brake torque by regeneration in a traction motor for each wheel. The brake torque to be provided is calculated for each wheel. A maximum regenerative energy is calculated for each wheel. A hydraulic pressure calculating unit calculates a hydraulic pressure to be provided to the wheel cylinder of each wheel based on the brake torque and the maximum regenerative energy so that the regenerative energy generated by the traction motor of each wheel becomes a maximum. The hydraulic pressure calculated by the hydraulic pressure calculating unit is provided to the wheel cylinder of a corresponding wheel by a hydraulic pressure control valve which generates the hydraulic pressure by reducing a master cylinder pressure.
摘要:
Vehicle hydraulic braking system including a hydraulic pressure source for pressurizing a fluid according to an operation of a brake operating member, so that the pressurized fluid is supplied to at least one wheel brake cylinder for braking at least wheel of the vehicle, a pressure control valve device for regulating the pressure of the fluid to be applied to each wheel brake cylinder, the valve device having a pressure-increasing, pressure-holding and pressure-reducing states, and a reservoir for storing the fluid which has been discharged from each wheel brake cylinder through the pressure control valve device during the operation of the brake operating member, so that the fluid is returned from the reservoir to the hydraulic pressure source after the operation of the brake operating member. The reservoir has a storage capacity smaller than a maximum total amount of the fluid that can be accommodated in all of the at least one wheel brake cylinder during operation of the at least one wheel brake cylinder.
摘要:
A brake fluid pressure control apparatus achieves a sufficiently large brake force even when a malfunction occurs in an operational force sensor for detecting a level of operational force applied to a brake system. A magnitude of a master cylinder pressure generated by a master cylinder is detected by a master cylinder pressure sensor. A linear fluid pressure source generates a linear fluid pressure adjusted by the magnitude of the master cylinder pressure. Front wheel cylinders and rear wheel cylinders are provided with the linear fluid pressure. A front wheel cylinder pressure is detected and a front wheel cylinder pressure value corresponding to a magnitude of the front wheel cylinder pressure is output by a front wheel cylinder sensor. If it is determined that a malfunction is occurring in the operational force sensor, a connection of the front wheel cylinders is switched from the linear fluid pressure source to the master cylinder. At this time, the linear fluid pressure source is controlled based on the front wheel cylinder pressure value.
摘要:
A hydraulic brake control apparatus in which a master cylinder supplies a brake fluid pressure responsive to a brake operating force to wheel cylinders through a first valve, includes a first control unit which controls second valves and third valves when a brake fluid pressure supplied to the wheel cylinders by a pressure supplying device is detected to be excessively high under a condition in which the supply of the brake fluid pressure to the wheel cylinders by the master cylinder is inhibited by the first valve, so that the supply of the brake fluid pressure to the wheel cylinders by the pressure supplying device is inhibited by the second valves and a flow of the brake fluid from the wheel cylinders into a reservoir tank is allowed by the third valves. A second control unit controls the third valves and the first valve at a predetermined time after the flow of the brake fluid from the wheel cylinders into the reservoir tank is allowed, so that the flow of the brake fluid from the wheel cylinders into the reservoir tank is inhibited by the third valves and the supply of the brake fluid pressure to the wheel cylinders by the master cylinder is allowed by the first valve.
摘要:
In a brake fluid control device, front wheel cylinders are connected to a front hydraulic circuit, and rear wheel cylinders are connected to a rear hydraulic circuit. The front hydraulic circuit and the rear hydraulic circuit are connected to a front left pressure-decrease valve, a front right pressure-decrease valve, a rear left pressure-decrease valve, a rear right pressure-decrease valve and a connecting pipe. When a brake pedal is depressed, the front left pressure-decrease valve, the front right pressure-decrease valve, the rear left pressure-decrease valve and the rear right pressure-decrease valve are opened and a master cylinder pressure sensor leads to both the front hydraulic circuit and the rear hydraulic circuit. Comparing a detection value of the of the master cylinder pressure sensor, a detection value of a front wheel cylinder pressure sensor and a detection value of a rear wheel cylinder pressure sensor respectively, detects the state of operation of each of the sensors provided in the system.
摘要:
A hydraulic brake control apparatus in which a master cylinder is connected to wheel cylinders via a master cylinder cut valve, and the wheel cylinders are connected to a reservoir tank via a switching valve, includes a check valve provided between the master cylinder and the wheel cylinders in parallel with the master cylinder cut valve, the check valve provided in a bypass passage of the master cylinder cut valve, the check valve allowing a flow of a brake fluid from the master cylinder to the wheel cylinders and inhibiting a flow of the brake fluid from the wheel cylinders to the master cylinder. A valve control unit controls the switching valve when it is detected that a closed-position defect in the master cylinder cut valve has occurred and a pressure of the brake fluid in the master cylinder is decreasing, so that the switching valve is set at an open position to allow a flow of the brake fluid from the wheel cylinders to the reservoir tank through the switching valve and reduce a pressure of the brake fluid in the wheel cylinders.
摘要:
Hydraulic pressure control apparatus for controlling a pressure of a brake cylinder pressure, including a pump device connected to the brake cylinder and including at least one set of a pump for delivering a pressurized fluid to the brake cylinder and a pump operating electric motor, a low-pressure source for storing the fluid discharged from the brake cylinder, a solenoid-operated pressure control valve disposed between the low-pressure source and the brake cylinder and operated with an electric energy applied thereto, for controlling the brake cylinder pressure depending upon the electric energy, and a controller including a pressure increase control device for increasing the brake cylinder pressure by controlling the electric motor, and a pressure reduction control device or reducing the brake cylinder pressure by controlling the electric energy applied to the control valve.
摘要:
A hydraulic brake system is provided which does not need a mechanism to feed back the wheel cylinder pressure. The hydraulic brake system generates a brake force by supplying the brake fluid to a wheel cylinder under a high pressure generated by a high pressure source. The brake fluid is supplied to the high pressure source from a reservoir tank storing the brake fluid under atmospheric pressure. A fluid passage connects the high pressure source to both the wheel cylinder and the reservoir tank. An amount of the brake fluid flowing from the high pressure source to the wheel cylinder is controlled by a constant flow valve.
摘要:
A hydraulic braking apparatus for braking a vehicle wheel, wherein a pressure control valve is disposed between a master cylinder and a wheel brake cylinder, and between a reservoir and a hydraulic pressure source which is independent of the master cylinder and whose pressure is applied as a braking pressure to the wheel brake cylinder for braking the wheel. The pressure control valve controls the braking pressure as a function of the master cylinder pressure which is generated by the master cylinder, depending upon the operating force acting on a brake operating member. An electrically controlled pressure regulating device is provided for applying an electrically controlled force to the pressure control valve, to thereby regulate the braking pressure to be applied to the wheel brake cylinder.