摘要:
The present invention relates to a brake fluid pressure control apparatus in which a casing contains a pump communication port separately from a master cylinder communication port. A spool is also provided which limits the communication between the pump communication port and the master cylinder communication port in a manner such that the discharge pressure from the pump is not added directly to the master cylinder. Additionally, in the intake and discharge sides of the pump, a bypass channel is provided. In this bypass channel, a relief valve is provided which allows the escape of pressure force to the intake side of the pump in the case when the pressure force between the discharge side of the pump and the flow control increases to a high pressure. Furthermore, because the brake fluid is normally designed to be discharged from the pump to the flow control valve at approximately a fixed flow rate by means of the relief valve, there is no return of brake fluid to the master cylinder via the flow control valve, and stroke fluctuations of the master cylinder can be eliminated. Additionally, the necessity for providing an orifice between a pump communication port and the master cylinder communication port disappears.
摘要:
The present invention presents an economical fluid pressure control device particularly applicable to controlling the fluid pressure in the wheels of an automobile provided with an antiskid capability so that the unpleasant pedal kickbacks are prevented under various operating conditions of the wheels. This is achieved by providing at least two wheel cylinders for one pressure generation source, a reservoir and a pump. A flow valve provided on each of the wheel cylinders is provided with a simple flow switching device which control the position of a spool, disposed inside the flow valve, which assumes a stationary position for non-antiskid operation mode and a operation position for antiskid operation mode. When one of the wheels is in the antiskid operation mode, and the other wheel is in non-antiskid operation mode, the brake fluid discharged from the pump is not allowed to enter the flow valve disposed in the non-antiskid operation mode. Therefore, the fluid pressure pulsations generated in the fluid circuit in the antiskid operation mode are not transmitted back to the pressure generation source through the flow valve in the non-antiskid operation mode. Therefore, there in no transmission of unpleasant pedal kickbacks at the pressure generation source.
摘要:
The present invention relates to a brake fluid pressure control apparatus in which a casing contains a pump communication port separately from a master cylinder communication port. A spool is also provided which limits the communication between the pump communication port and the master cylinder communication port in a manner such that the discharge pressure from the pump is not added directly to the master cylinder. Additionally, in the intake and discharge sides of the pump, a bypass channel is provided. In this bypass channel, a relief valve is provided which allows the escape of pressure force to the intake side of the pump in the case when the pressure force between the discharge side of the pump and the flow control valve increases to a high pressure. Furthermore, because the brake fluid is normally designed to be discharged from the pump to the flow control valve at approximately a fixed flow rate by means of the relief valve, there is no return of brake fluid to the master cylinder via the flow control valve, and stroke fluctuations of the master cylinder can be eliminated. Additionally, the necessity for providing an orifice between a pump communication port and the master cylinder communication port disappears.
摘要:
A brake fluid pressure adjustment device is presented for controlling the wheel lock of a vehicle by controlling the flow of the brake fluid from the main fluid path to the bypass path by means of a pumping mechanism which is in constant operation. The pumping mechanism includes a suction valve which only allows a unidirectional flow of brake fluid from the pump, and a reservoir to the pump; an electromagnetic device which forces open the bypass path between the pump and the reservoir by attracting the bypass path control valve element in one direction; and a discharge valve which allows only the flow of brake fluid from the pump to the main fluid path. Therefore, by controlling the actions of the electromagnetic means, it is possible to control the decrease, holding and increase actions of the pressure adjustment device, without stopping and starting the pump. The device thereby provides a delicate and timely response to the brake pressure variation needs without being affected by the inertial effects of the pump.
摘要:
The present invention relates to a brake fluid pressure control apparatus provided with a flow valve which, during the normal operation, when a spool is in the stationary position, a master cylinder communication port is communicated with a wheel cylinder communication port while the pump communication port is closed, and during an antiskid control operation, a pump communication port and a wheel cylinder communication port are communicated, as well as a switching device to switch between the first and the second conditions. In the first condition, a master cylinder communication port is communicated with the output fluid passage of the master cylinder while the communication between the pump communication port and the master cylinder communication port is shut off. In the second condition, the communication between the master cylinder communication port and the output fluid passage of the master cylinder is shut off while the pump communication port and the master cylinder communication port are communicated. Therefore, when two functions, antiskid and traction controls, are to be provided to a brake fluid pressure control apparatus having an antiskid control capability, there is no need to change the flow valve itself, in particular the spool, to provide the two functions.
摘要:
An anti-skid device for use in a vehicle hydraulic brake system comprising a hydraulic pressure generating device for generating hydraulic pressure in response to actuation of a brake pedal, a brake cylinder for receiving the hydraulic pressure from the hydraulic pressure generating device and for applying brake force to a wheel of the vehicle, a passage through which the hydraulic pressure is adapted to be transmitted from the hydraulic pressure generating device to the brake cylinder, lock detecting device for detecting that a wheel is locked and a damping valve designed to function to interrupt the transmission of the hydraulic pressure from the hydraulic pressure generating device to the brake cylinder and to further reduce the pressure in the brake cylinder when the lock detecting mechanism detects that wheel is locked so that the wheel-lock may be released. The damping valve comprises a plunger movable such as to open and close a valve seat and a diaphragm for movably supporting the plunger and for liquid-tightly sealing a valve chamber defined around the valve seat. The plunger is integrated with the diaphragm by bonding and is provided at one end thereof with a valve body having a spherical surface portion for contacting the valve seat.
摘要:
A master cylinder of the invention supplies a brake fluid from a large diameter pressurizing chamber 56 to a small diameter hydraulic chamber 49 by opening a reverse flow checking opening and closing portion 61 by sliding movement of a stepped piston 16 forwardly, that is, fast fill and when the hydraulic pressure of the large diameter pressurizing chamber 56 rises, a control valve 86 escapes the hydraulic pressure of the large diameter pressurizing chamber 56 to a reservoir 12 to gradually lower in accordance with rise of the hydraulic pressure of the small diameter hydraulic chamber 49, thereby capable of reducing a strange feeling in a pedal feeling caused by sudden pressure release of the large diameter pressurizing chamber 56.
摘要:
A master cylinder includes a cylinder, a piston slidably provided in the cylinder, an annular cup seal held on an inner circumferential surface of the cylinder, and a relief port formed in the piston. The piston and the cylinder define a pressure chamber for generating fluid pressure in front of the piston, and the cylinder and an outer circumferential surface of the piston define a fluid supply chamber which communicates with a reservoir. The cup seal is adapted to slide against the outer circumferential surface of the piston to separate the fluid supply chamber from the pressure chamber. The relief port provides communication between the pressure chamber and the fluid supply chamber. A control taper surface is formed on the outer circumferential surface of the piston rearwardly from the relief port. The control taper surface is tapered toward the front of the piston and is capable of abutting against an inner circumferential surface of the cup seal.
摘要:
A plunger moved with an input shaft is movably fitted in an axial bore of a valve body made of resin, and a valve mechanism selectively establishes and cuts off communication in a negative pressure passage and an atmosphere passage formed in the valve body according to the movement of the plunger. Also, a pair of radial holes formed to have a circular cross section are provided in the valve body by drilling work, and a plate type stop key formed in a fork shape having two claw branches is mounted by loosely inserting the branches in the radial holes. The stop key limits a movement range of the plunger. Also, a guide portion is formed on an outer circumference of the valve body to guide side surfaces of the stop key. The movement of the stop key is restricted by the guide portion and a step formed in the axial bore of the valve body. Therefore, a smooth operation of the pneumatic booster can be guaranteed.
摘要:
A vehicle braking system for use in a vehicle such as an automobile, and including at least one wheel brake, a brake pedal, and a brake applying device such as a master cylinder or a pneumatic booster which is connected to the brake pedal for applying hydraulic pressure on the wheel brake in response to actuation of the brake pedal. A selector valve is connected to the brake applying device and acts, when actuated, to maintain hydraulic pressure in the wheel brake irrespective to the release of the brake pedal. Further, there are provided at least one sensor such as a sensor sensing the running speed of the vehicle, a sensor sensing the actuation of a gas pedal, a sensor sensing whether a seat belt in the driver's seat is fitted on or not and the like, and a controller connected to the sensor for actuating the selector valve in response to a predetermined operational condition of the vehicle.