Abstract: When the increasing gradient of the operating power is larger than a predetermined gradient, if a master pressure PM2 corresponding to a second predetermined operating power F2 is larger than a second predetermined fluid pressure Pth2, a servo function failure in the brake operation is determined; if it is smaller than the second predetermined fluid pressure Pth2, fluid leakage failure (S23, S26, S27) is determined. Furthermore, if the master pressure PM0 corresponding to the first predetermined operating power F0 is larger than a first predetermined fluid pressure Pth1, small amount fluid leakage failure is determined; if it is smaller than the first predetermined fluid pressure Pth1, large amount fluid leakage failure (S28, S29, S30) is determined.

Abstract: A vehicular safety apparatus of the present invention is one actuated according to a collision prediction level of a vehicle. The vehicular safety apparatus of the present invention is provided with a determining device for determining a collision prediction level on the basis of a relative position between a vehicle and an obstacle ahead of the vehicle; a storage for storing a amount of brake operation by a driver at a point where the collision prediction level exceeds a predetermined threshold, as a reference level; and an actuation controller for actuating the safety apparatus in accordance with an increase from the reference level. This prevents the actuation of the safety apparatus from being excessive in the case where an increase of the amount of brake operation is low. Furthermore, in the case of the increase being high, the actuation is controlled so as to fully bring out the performance of the safety apparatus.

Abstract: Vehicle braking system including a vacuum booster for transmitting a boosted brake operating force to a master cylinder such that the boosting ratio is reduced at a fixed transition point before the boosting limit point is reached, a brake having a wheel brake cylinder connected through a fluid passage to a master cylinder serving as a first hydraulic pressure source, for braking a wheel, and a pressure increasing device having a second hydraulic pressure source connected to the fluid passage, and wherein the pressure increasing device initiating a pressure increasing operation, when the brake operating force has increased to the transition point, to increase the wheel cylinder pressure to be higher than the master cylinder pressure, by using the second hydraulic pressure source.

Abstract: A Hydraulic pressure control apparatus, includes a hydraulic pressure source device operable according to a control amount, to generate an output pressure thereof on the basis of a fluid pressure corresponding to an operating force of a manually operable operating member, and on the basis of a control pressure controlled by a pressure control actuator according to a control amount. The control apparatus further includes an actuator control device including a final-control-value determining portion operable to determine a final value of the control amount, which is used to control the pressure control actuator. A final control value is determined on the basis of at least two provisional control values.

Abstract: A vacuum booster apparatus used for a brake apparatus positively decreases a degree of opening of a throttle valve when it is required while an unnecessary decrease in the degree of opening of the throttle valve is positively prevented. A first pressure chamber of a vacuum booster is connected to an intake pipe of the engine on a downstream side of a throttle valve. A second pressure chamber of the vacuum booster is selectively connectable to one of the first pressure chamber and atmosphere. The vacuum booster boosts an operating force applied to a brake operating member based on a pressure difference between the first pressure chamber and the second pressure chamber. A throttle-opening-degree control device controls a negative pressure in the first pressure chamber by controlling the degree of opening of the throttle valve.

Abstract: A vacuum booster apparatus used for a brake apparatus positively decreases a degree of opening of a throttle valve when it is required while an unnecessary decrease in the degree of opening of the throttle valve is positively prevented. A first pressure chamber of a vacuum booster is connected to an intake pipe of the engine on a downstream side of a throttle valve. A second pressure chamber of the vacuum booster is selectively connectable to one of the first pressure chamber and atmosphere. The vacuum booster boosts an operating force applied to a brake operating member based on a pressure difference between the first pressure chamber and the second pressure chamber. A throttle-opening-degree control device controls a negative pressure in the first pressure chamber by controlling the degree of opening of the throttle valve.

Abstract: In a vehicle brake control device, it is determined whether a first starting condition, that a master cylinder pressure and a rate of change of the master cylinder pressure are equal to or more than respective first reference values, is satisfied. Furthermore, it is determined whether a second starting condition is satisfied based on a determination as to whether the master cylinder pressure is equal to or more than a second reference value at a time when a predetermined time has elapsed since a time when the first starting condition was satisfied . In a case where the second starting condition is determined as being satisfied, a brake assist control is executed until a termination condition of the brake assist control is satisfied.

Abstract: A braking system including (a) a hydraulically operated brake cylinder for operating a brake, (b) a master cylinder operable according to an operation of a manually operable brake operating member, to pressurize a working fluid, (c) a master-cylinder cut-off valve connected to the master cylinder, (d) a high-pressure source such as a power-operated pressure-control cylinder disposed between the master-cylinder cut-off valve and the brake cylinder and operable according to the operation of the brake operating member, to pressurize the fluid, the high-pressure source including a power-operated drive device and a pressure-control cylinder having a control piston which is operable by the power-operated drive device and which partially defines on respective front and rear sides thereof a front control-pressure chamber connected to the brake cylinder, and a rear pressure chamber which is held in communication with the master cylinder, and (e) a braking-pressure control device (200) operable to control the power-ope

Abstract: A braking system including: (a) a hydraulically operated brake cylinder capable of operating a brake; (b) a pressure control cylinder having (b-1) a housing, (b-2) a piston displaceable by activation of a drive source, and (b-3) a pressure controlling chamber located on a front side of the piston and connected to the brake cylinder, so that a working fluid can be supplied from the pressure controlling chamber to the brake cylinder, by displacement of the piston; and (c) a braking-pressure control device operable to control the activation of the drive source, for controlling a pressure of the working fluid in the pressure controlling chamber or in the brake cylinder.

Abstract: A braking system for braking a wheel of an automotive vehicle, including a brake for braking the wheel and an operating device operable to produce an output corresponding to an input thereof, for activating the brake according to the output, and wherein a change of the output of the operating device is delayed with respect to a change of the input depending upon an operating condition of the braking system. The braking system includes a brake-operating-force increasing device operable on the basis of a delay of the change of the output of the operating device with respect to the change of the input, to increase an operating force of the brake to a value which is larger than a value corresponding to the output of the operating device.

Abstract: A vehicle braking pressure source device including (a) a master cylinder having a pressurizing piston cooperating with a cylinder housing to define a pressurizing chamber and a back-pressure chamber on front and rear sides of the piston, and an input rod which slidably extending through a rear end wall of the cylinder housing such that the piston is advanced by a brake operating force of a brake operating member transmitted thereto through the input rod, to pressurize a working fluid in the pressurizing chamber, (b) a communication passage for communication between the pressurizing and back-pressure chambers, (c) a control valve device disposed in the communication passage for controlling the communication between the pressurizing and back-pressure chambers through the communication passage, and (d) a control valve control device for controlling the control valve device, on the basis of at least one of an operating state of the brake operating member, a running state of the vehicle and a state of a road surfa

Abstract: A braking system including (a) a hydraulically operated brake cylinder for operating a brake, (b) a master cylinder operable according to an operation of a manually operable brake operating member, to pressurize a working fluid, (c) a master-cylinder cut-off valve connected to the master cylinder, (d) a high-pressure source such as a power-operated pressure-control cylinder disposed between the master-cylinder cut-off valve and the brake cylinder and operable according to the operation of the brake operating member, to pressurize the fluid, the high-pressure source including a power-operated drive device and a pressure-control cylinder having a control piston which is operable by the power-operated drive device and which partially defines on respective front and rear sides thereof a front control-pressure chamber connected to the brake cylinder, and a rear pressure chamber which is held in communication with the master cylinder, and (e) a braking-pressure control device (200) operable to control the power-ope

Abstract: In an enabled mode of a first-fill device, if a fluid pressure in a first pressurizing chamber is lower than a predetermined value, a working fluid can be supplied to a brake cylinder from both the first pressurizing chamber and a second pressurizing chamber. If the fluid pressure in the first pressurizing chamber becomes higher than the predetermined value, the working fluid can be supplied only from the second pressurizing chamber. On the other hand, in a disabled mode of the first fill device, no matter how high the fluid pressure in the first pressurizing chamber is, the working fluid is supplied to the brake cylinder only from the second pressurizing chamber or supplied from both the first pressurizing chamber and the second pressurizing chamber.

Abstract: A vehicle braking system including a master cylinder having a pressurizing piston fluid-tightly and slidably received in a cylinder housing and cooperating with the cylinder housing to define a pressurizing chamber and an assisting chamber on opposite sides of the piston, a brake operating member for applying a pressurizing force to the piston, a wheel brake cylinder connected to the master cylinder for activating a brake for braking a wheel, a hydraulic pressure source for pressuring a working fluid, a reservoir, a first flow control device for controlling flows of the fluid between the assisting chamber, and the hydraulic pressure source and reservoir, and a second flow control device or controlling flows of the fluid between the pressurizing chamber, and the hydraulic pressure source and reservoir.

Abstract: A vacuum booster apparatus used for a brake apparatus positively decreases a degree of opening of a throttle valve when it is required while an unnecessary decrease in the degree of opening of the throttle valve is positively prevented. A first pressure chamber of a vacuum booster is connected to an intake pipe of the engine on a downstream side of a throttle valve. A second pressure chamber of the vacuum booster is selectively connectable to one of the first pressure chamber and atmosphere. The vacuum booster boosts an operating force applied to a brake operating member based on a pressure difference between the first pressure chamber and the second pressure chamber. A throttle-opening-degree control device controls a negative pressure in the first pressure chamber by controlling the degree of opening of the throttle valve.

Abstract: A vacuum booster apparatus used for a brake apparatus positively decreases a degree of opening of a throttle valve when it is required while an unnecessary decrease in the degree of opening of the throttle valve is positively prevented. A first pressure chamber of a vacuum booster is connected to an intake pipe of the engine on a downstream side of a throttle valve. A second pressure chamber of the vacuum booster is selectively connectable to one of the first pressure chamber and atmosphere. The vacuum booster boosts an operating force applied to a brake operating member based on a pressure difference between the first pressure chamber and the second pressure chamber. A throttle-opening-degree control device controls a negative pressure in the first pressure chamber by controlling the degree of opening of the throttle valve.

Abstract: A vacuum booster apparatus used for a brake apparatus positively decreases a degree of opening of a throttle valve when it is required while an unnecessary decrease in the degree of opening of the throttle valve is positively prevented. A first pressure chamber of a vacuum booster is connected to an intake pipe of the engine on a downstream side of a throttle valve. A second pressure chamber of the vacuum booster is selectively connectable to one of the first pressure chamber and atmosphere. The vacuum booster boosts an operating force applied to a brake operating member based on a pressure difference between the first pressure chamber and the second pressure chamber. A throttle-opening-degree control device controls a negative pressure in the first pressure chamber by controlling the degree of opening of the throttle valve.

Abstract: A vacuum booster apparatus used for a brake apparatus positively decreases a degree of opening of a throttle valve when it is required while an unnecessary decrease in the degree of opening of the throttle valve is positively prevented. A first pressure chamber of a vacuum booster is connected to an intake pipe of the engine on a downstream side of a throttle valve. A second pressure chamber of the vacuum booster is selectively connectable to one of the first pressure chamber and atmosphere. The vacuum booster boosts an operating force applied to a brake operating member based on a pressure difference between the first pressure chamber and the second pressure chamber. A throttle-opening-degree control device controls a negative pressure in the first pressure chamber by controlling the degree of opening of the throttle valve.

Abstract: A vacuum booster apparatus used for a brake apparatus positively decreases a degree of opening of a throttle valve when it is required while an unnecessary decrease in the degree of opening of the throttle valve is positively prevented. A first pressure chamber of a vacuum booster is connected to an intake pipe of the engine on a downstream side of a throttle valve. A second pressure chamber of the vacuum booster is selectively connectable to one of the first pressure chamber and atmosphere. The vacuum booster boosts an operating force applied to a brake operating member based on a pressure difference between the first pressure chamber and the second pressure chamber. A throttle-opening-degree control device controls a negative pressure in the first pressure chamber by controlling the degree of opening of the throttle valve.

Abstract: A diagnosing apparatus for diagnosing a pressurizing device provided in a hydraulically operated braking system operated by a brake operating member, wherein a hydraulic pressure detecting device is operable to detect a hydraulic pressure which is a sum of a first fluid pressure generated by an operation of the brake operating member, and a second fluid pressure generated by an operation of the pressurizing device, and a diagnosing device is operable to determine whether the pressurizing device is abnormal or not, on the basis of the hydraulic pressure detected while the brake operating member is not in operation and while the pressurizing device is in operation.