Abstract: A vehicle brake control unit includes a cylinder body (2); a spool member (18) which is slidably provided in the cylinder body (2), and has one end portion confronted with a pressure chamber (10) and the other end portion confronted with a regulator pressure chamber (24) in the cylinder body, the spool member being axially moved by both the pressure in the pressure chamber and the pressure in the regulator pressure chamber, thus adjusting the pressure of a pressure source (26) which is applied to a regulator port (2a) formed in the cylinder body. The pressure provided at the regulator port is led into the regulator pressure chamber and supplied to the wheel cylinders (33, 34, 35 and 36).

Abstract: A hydraulic brake device for a vehicle includes a reservoir for storing brake fluid, a master cylinder connected to the reservoir generating brake pressure responsive to an operation force of a brake pedal, a hydraulic power source connected to the reservoir generating hydraulic pressure responsive to the operation force of the brake pedal, a wheel brake for applying a brake force and a pressure control unit connecting the wheel brake to the master cylinder, the reservoir and the hydraulic power source to control brake fluid flow into the reservoir from the wheel brake and brake fluid flow into the wheel brake from the hydraulic power source.

Abstract: A hydraulic braking pressure control apparatus for an automotive vehicle, having a master cylinder integrally provided with an ABS actuator or an ABS actuator and a TRC actuator, the ABS actuator being in the form of an anti-lock actuator which is activated under control of a computer for controlling hydraulic braking pressure applied to each road wheel of the vehicle in braking operation, and the TRC actuator being in the form of a traction control actuator which is activated under control of the computer for controlling slippage of driven road wheels during travel of the vehicle, wherein a solenoid valve assembly composed of a plurality of solenoid valves of the ABS actuator or the ABS and TRC actuators is mounted on one side of a cylinder body of the master cylinder, while other component parts of the ABS actuator or the ABS and TRC actuators are mounted within a housing structure integrally formed with the cylinder body of the master cylinder a the other side thereof.

Abstract: In a hydraulic brake system for a vehicle, the brake fluid in a first wheel brake and the brake fluid in a second wheel brake which are hydraulically connected to a pressure generating chamber of a master cylinder are individually caused to flow into a low back pressure reservoir with the aid of an electromagnetic change-over valve and first and second electromagnetic cut-off valves; and with a pump driven by an electric motor, the brake fluid flowing in the low back pressure reservoir in the above-described manner is caused to flow through a first check valve and a first orifice to the first wheel brake, and through a second check valve and a second orifice to the second wheel brake. With the pump operated, the first and second electromagnetic cut-off valves are individually operated, so that the first and second wheel brakes are individually decreased or reincreased in hydraulic pressure. For traction control, electromagnetic change-over valves provided in bypass passages are operated.

Abstract: A hydraulic brake device for a vehicle includes a reservoir for storing brake fluid, a master cylinder for generating brake pressure corresponding to an operation force of a brake operation member of the vehicle which is connected to the reservoir, a regulator valve for generating brake pressure corresponding to an operation force of a brake operation member of the vehicle which is connected to the reservoir, a wheel brake, and a pressure control unit which connects the wheel brake to the master cylinder and connects the wheel brake to the regulator valve to control a flow into the reservoir from the wheel brake and a flow into the wheel brake from the regulator valve under an anti-lock condition.

Abstract: The present invention is directed to a hydraulic braking system having a hydraulic braking pressure circuit for braking each wheel of an automotive vehicle with brake fluid fed to a wheel cylinder operatively mounted on the wheel. The system includes an auxiliary pressure source which has an inlet for introducing the brake fluid and an outlet connected to the pressure circuit for discharging thereinto the pressurized brake fluid. A circulation passage is disposed between the outlet and the inlet for communicating with each other. An auxiliary valve is disposed in the circulation passage so as to open or close the passage. An auxiliary reservoir is connected to the circulation passage between the valve and the inlet of the source. The auxiliary reservoir has a capacity for storing a predetermined amount of brake fluid. And, a controller is provided for driving the source and actuating the valve so as to open or close the circulation passage.

Abstract: In a hydraulic brake system for a vehicle, the brake fluid in a first wheel brake and the brake fluid in a second wheel brake, which are hydraulically connected to a pressure generating chamber of a master cylinder, are caused to individually flow into a low back pressure reservoir with the aid of an electromagnetic change-over valve and electromagnetic cut-off valves. The brake fluid in the low back pressure reservoir is caused to flow through a check valve and an orifice into the first wheel brake and through another check valve and another orifice into the second first wheel brake by the operation of a pump which is driven by an electric motor. With the pump in operation, the electromagnetic cut-off valves are individually operated so that the first and second wheel brakes are decreased or reincreased in hydraulic pressure. Thus, the system is low in manufacturing cost, being operable with only one pump and only one low back pressure reservoir.

Abstract: A brake pressure generating device for a vehicle includes a cylinder body, a pressure source connected with the cylinder body for generating a pressure, a first piston slidably disposed in the cylinder body for being operated by a brake pedal of the vehicle, a sleeve member disposed in the cylinder body for forming a pressure chamber with the first piston at one end thereof and for being exposed to a regulated pressure chamber at the other end thereof, and a spool valve slidably disposed in the sleeve member for regulating the pressure of the pressure source. A second piston is slidably disposed in the sleeve member for receiving the pressure in the pressure chamber at one end thereof and for being connected with the spool valve to impart a force the spool valve. An elastic member is disposed in the cylinder body and receives a pressure in the regulated pressure chamber. A reaction member is connected with the spool valve at one end thereof and is in contact with the elastic member at the other end thereof.

Abstract: The invention is directed to a pressure control apparatus in a vehicle braking system which has a wheel cylinder operatively mounted on a wheel, a reservoir for storing an amount of brake fluid, and a master cylinder for receiving the brake fluid from the reservoir and generating a master cylinder pressure in response to depression of a brake pedal. The pressure control apparatus includes a housing which defines therein a pressure chamber which communicates with the wheel cylinder, and a control device which is actuated by a current fed thereto for providing a set pressure in response to the current and regulating the pressure in the pressure chamber into the set pressure.

Abstract: A hysteresis control valve (10) is disposed between a master cylinder and a wheel cylinder. The hysteresis control valve comprises a first stepped piston (12) fixed within a cylinder bore (11a) and including a bypass bore (12b) communicatable with the wheel cylinder, a second stepped piston (13) slidably mounted within the cylinder bore (11a) and having at its one end a valve body (14) opened under a given pressure to prevent communication through the bypass bore 12b, and a cup seal (15) disposed between the outer periphery of the first stepped piston (12) and the inner periphery of the cylinder bore (11a).

Abstract: A hydraulic brake system operates so that under anti-lock control, the braking forces for the rear wheels are enhanced in order to reduce braking loads for the front wheels. Further, upon the occurrence of a malfunction of the anti-locking control, the hydraulic pressure which is supplied to the front and the rear wheels is equalized in order to prevent the rear wheels from locking. In preferred embodiments, a small hydraulic pressure is supplied from a master cylinder to the front wheels while a large pressure is supplied from a brake booster to the rear wheels. Due to the large fluid pressure, the braking forces of the rear wheels are enhanced so that the rear wheels might tend to lock easily. However, anti-lock control can be performed effectively in order to avoid the rear wheels from locking. Upon the malfunction of the anti-lock control, a switching valve is operated so that the brake pressure which is supplied to the front and the rear wheels is equalized.

Abstract: A hydraulic braking system for an automotive vehicle having a power pressure source for generating a hydraulic power pressure, a master cylinder generating a hydraulic braking pressure in response to depression of a brake pedal, a dynamic hydraulic pressure generator for regulating the hydraulic power pressure in response to depression of the brake pedal and generating a regulated braking pressure, and a plurality of wheel brake cylinders for braking respective road wheels with one of the hydraulic braking pressure supplied from the master cylinder and the regulated braking pressure supplied from the dynamic hydraulic pressure generator.

Abstract: An electromagnetic valve of the present invention includes a housing 11,13, a fluid passage 12 provided in the housing 11,13, a valve member 18,21 for opening and closing the fluid passage 12, and a one way valve 25 having a valve member 26 and a valve seat 19b. The one way valve 25 is provided at one end of the fluid passage 12. The one way valve 25 is installed integrally within the housing 11,13 to facilitate installation in a small space.

Abstract: There is disclosed an automotive hydraulic brake booster in which a driver feels a brake pedal moving smoothly as he or she pushes down on the brake pedal. The booster includes a housing connected with a master cylinder, an input rod, a booster chamber formed in the housing, a power piston sliding inside the booster chamber, and a reaction piston connected to the input rod and inserted in a hole formed in the power piston. A linkage is connected to a valve for boosting the force supplied to the master cylinder and connected to the reaction piston. The reaction piston can move a given distance relative to the power piston in response to the input rod, this distance being determined by a stop. The stop and the connection between the input rod and the reaction piston are on the same side of the connection between the linkage and the reaction piston. A reaction chamber is formed in said hole by the reaction piston.

Abstract: A hydraulic braking system includes a master cylinder having a bore with an opening and a closed wall at opposite ends. At least one piston is slidably fitted in the bore and operatively connected to a brake pedal and at least one pressure chamber is defined in the bore by the piston and in communication with wheel cylinders of the vehicle. A normally open valve is associated with the piston so as to close a passage communicating between a reservoir and the pressure chamber when the piston is moved in response to the depression of the brake pedal. A hydraulic booster actuates the master cylinder in response to depression of the brake pedal, and an interrupting device interrupts the communication between the pressure chamber and the reservoir before the normally open valve closes the passage means and is interposed between the pressure chamber and the reservoir. Thereby, the idle stroke of previous master cylinders is eliminated.

Abstract: The invention is directed to a hydraulic booster for use in a hydraulic braking system of an automotive vehicle having a power source for generating a hydraulic power pressure, a reservoir and a master cylinder for generating a hydraulic braking pressure in response to movement of an input rod. The hydraulic booster has a housing defining therein a boost chamber, a power piston received in the boost chamber for transmitting a boost force to the master cylinder, and a pressure control valve which introduces the hydraulic power pressure from the power source and controls it in response to the movement of the input rod. The pressure control valve includes a cylinder defining therein a bore and a spool received in the bore. The spool has an axial hole and at least two radial holes facing each other and communicating with the axial hole.

Abstract: A hydraulic braking system includes the third piston slidably disposed between the first piston and the second piston of the tandem master cylinder so as to define the third pressure chamber between the third piston and second piston. The third pressure chamber is communicated with the dynamic hydraulic pressure generator. Thereby, due to supply the output hydraulic pressure of the dynamic hydraulic pressure generator to the third pressure chamber, the initial stroke of the brake pedal is reduced and the braking force is ensured as the ordinaly tandem master cylinder when the dynamic hydraulic pressure generator is not operated. Moreover, if the leakage of the brake fluid generates in the wheel cylinders, the flow of the brake fluid of the dynamic hydraulic pressure generator does not generate.

Abstract: The invention is directed to a hydraulic braking system for an automotive vehicle having a power source for generating a hydraulic power pressure, a reservoir, a master cylinder, a hydraulic booster for actuating the master cylinder in response to depression of a brake pedal and a plurality of wheel brake cylinders for braking respective road wheels. The hydraulic booster has a power piston for actuating a master piston of the master cylinder, and defines a first boost chamber which introduces the hydraulic power pressure from the power source to apply to the power piston, and a second boost chamber which is separated from the first boost chamber by the power piston and which introduces a hydraulic pressure from the first boost chamber to actuate the master piston.

Abstract: A hydraulic braking system includes a piston disposed at a wall end of the bore of a master cylinder so as to move a normally open valve mechanism of the master cylinder toward a closed position by applying an output pressure from a boost device or dynamic hydraulic generator. Due to applying the output pressure of the boost device or the dynamic hydraulic pressure generator to the piston, the initial stroke of the brake pedal is reduced by decreasing the idle stroke of the master cylinder and the braking pressure is ensured from the master cylinder when the output pressure of the boost device or the dynamic hydraulic pressure generator is not applied.

Abstract: A hydraulic power booster having a lever device disposed in operative association with a reaction piston, a power piston and a valve spool, for moving the valve spool in one of opposite axial directions thereof for applying a pressure of a pressure source into a power chamber to advance the power piston, in response to a relative movement between the reaction and power pistons. The booster is provided with a backup actuator including a cylinder, and a valve drive piston which slidably engages the cylinder. The cylinder and the valve drive piston cooperate with each other to define a first fluid chamber communicating with the power chamber, and a second fluid chamber communicating with a pressure chamber in which a pressure is generated according to an advancing force of the power piston.