Abstract: A hydraulic braking system includes: a master cylinder including a pressurizing piston, a rearward chamber, and a pressure chamber; and a rearward-hydraulic-pressure controller connected to the rearward chamber and including a pressure increase valve and a regulator for controlling a hydraulic pressure in an output chamber. An air detector includes: an upstream detector, including the rearward-hydraulic-pressure controller, for detecting presence or absence of air in an upstream portion based on a relationship between the hydraulic pressure in the output chamber and an open time of the pressure increase valve; and a downstream detector for detecting presence or absence of air in a downstream portion based on a relationship between a stroke of the pressurizing piston and the hydraulic pressure in the output chamber. The downstream portion includes a portion located downstream of the pressure chamber of the master cylinder.

Abstract: A method for detecting fluid leakage from a pressure-decrease valve in a hydraulic brake system having an ABS device including: a shutoff valve for shutting off supply of a working fluid from a fluid-pressure supply source to a brake device provided for a wheel; the pressure-decrease valve for discharging the working fluid from the brake device; a reservoir for storing the working fluid discharged from the pressure-decrease valve; and a return pump for returning the working fluid stored in the reservoir to a portion between the shutoff valve and the fluid-pressure supply source, the method including the steps of: activating the return pump in a state in which the hydraulic brake system is not in ABS operation, and detecting the fluid leakage from the pressure-decrease valve based on a variation in a pressure of the working fluid in the fluid-pressure supply source caused when the return pump is activated.

Abstract: The brake device for a vehicle generates two master pressures by controlling one single servo pressure to accurately control braking force. The pressure increasing characteristic is set based on the first pressure increasing characteristic obtained from the relationship between the servo pressure and the first master pressure upon increasing the servo pressure and the second pressure increasing characteristic obtained from the servo pressure and the second master pressure. The pressure decreasing characteristic is set based on the first pressure increasing characteristic obtained from the relationship between the servo pressure and the first master pressure upon decreasing the servo pressure and the second pressure decreasing characteristic obtained from the servo pressure and the second master pressure. Thus, the total braking force of the brake device is the sum of a braking force generated by the first master pressure and a braking force generated by the second master piston.

Abstract: The braking control device for controlling a master cylinder device includes a housing, an output piston, an input piston, a separation chamber opening and closing portion, and a driving hydraulic pressure generating portion, and is provided with an operation control for controlling the master cylinder device in an operation force operating state (regulator mode) in which the output piston is driven by operation force on a brake operation member and in a driving hydraulic pressure operating state (linear mode) in which the output piston is driven by driving hydraulic pressure from the driving hydraulic pressure generating portion; a brake operation judgment portion for judging the presence or absence of a brake operation and the probability thereof and a state transition limiter for limiting at least one of state transitions between the operating states when the presence of the brake operation and possibility thereof is determined.

Abstract: A hydraulic braking system includes: a master cylinder including a pressurizing piston, a rearward chamber, and a pressure chamber; and a rearward-hydraulic-pressure controller connected to the rearward chamber and including a pressure increase valve and a regulator for controlling a hydraulic pressure in an output chamber. An air detector includes: an upstream detector, including the rearward-hydraulic-pressure controller, for detecting presence or absence of air in an upstream portion based on a relationship between the hydraulic pressure in the output chamber and an open time of the pressure increase valve; and a downstream detector for detecting presence or absence of air in a downstream portion based on a relationship between a stroke of the pressurizing piston and the hydraulic pressure in the output chamber. The downstream portion includes a portion located downstream of the pressure chamber of the master cylinder.

Abstract: A braking device for a vehicle includes an operating characteristics setting portion for setting an operating characteristic which is a relationship between the input electric power to the electro-magnetic valve and a pressure difference between a master cylinder side and a wheel cylinder side with respect to the electro-magnetic valve, based on the input electric power at the time when the accumulator pressure detected by the accumulator pressure detecting portion first falls to a value equal to or less than a threshold value accumulator pressure by changing the input electric power towards an opening side of the electro-magnetic valve in response to a time lapsed after a predetermined value of the pilot pressure has been generated by the pilot pressure generating portion by first closing the electro-magnetic valve thereby to suppress the manufacturing cost.

Abstract: A method for detecting fluid leakage from a pressure-decrease valve in a hydraulic brake system having an ABS device including: a shutoff valve for shutting off supply of a working fluid from a fluid-pressure supply source to a brake device provided for a wheel; the pressure-decrease valve for discharging the working fluid from the brake device; a reservoir for storing the working fluid discharged from the pressure-decrease valve; and a return pump for returning the working fluid stored in the reservoir to a portion between the shutoff valve and the fluid-pressure supply source, the method including the steps of: activating the return pump in a state in which the hydraulic brake system is not in ABS operation, and detecting the fluid leakage from the pressure-decrease valve based on a variation in a pressure of the working fluid in the fluid-pressure supply source caused when the return pump is activated.

Abstract: A vehicle brake device is provided with a master piston which is driven to generate a master cylinder pressure. The device includes a pressure accumulation portion that accumulates the brake fluid under pressure; a servo pressure generation portion that is configured to be able to generate the servo pressure using the brake fluid in the pressure accumulation portion regardless of the operation of the brake operation member; brake fluid consumption correlative value detection means for detecting a brake fluid consumption correlative value relating to a consumption of the brake fluid in the pressure accumulation portion; and failure detection means for driving the master pistons only by the servo pressure using the servo pressure generation portion in a state where the brake operation member is not operated, and detecting a failure of a master system, based on a brake fluid consumption correlative value detected by the brake fluid consumption correlative value detection means at that time.

Abstract: The braking control device for controlling a master cylinder device includes a housing, an output piston, an input piston, a separation chamber opening and closing portion, and a driving hydraulic pressure generating portion, and is provided with an operation control for controlling the master cylinder device in an operation force operating state (regulator mode) in which the output piston is driven by operation force on a brake operation member and in a driving hydraulic pressure operating state (linear mode) in which the output piston is driven by driving hydraulic pressure from the driving hydraulic pressure generating portion; a brake operation judgment portion for judging the presence or absence of a brake operation and the probability thereof and a state transition limiter for limiting at least one of state transitions between the operating states when the presence of the brake operation and possibility thereof is determined.

Abstract: After a vehicle has entered a curve, a deviation (Sch) between a target turning state quantity Td and an actual turning state quantity Ta is computed. In a stage in which Sch does not reach a predetermined value after the vehicle has entered the curve, the possibility of the vehicle traveling in the curve is judged to be low, and the reliability of the curve information Rc, Pc is judged to be low. In this case, a determination for prohibiting execution of control (So=0) is made. In a stage after Sch has reached the predetermined value, the possibility of the vehicle traveling in the curve is judged to be high, and the reliability of the curve information Rc, Pc is judged to be high. In this case, a determination for permitting execution of the control (So=1) is made. Deceleration control is started and executed only when a control start condition is satisfied, and the determination for permission is made.

Abstract: The brake device for a vehicle generates two master pressures by controlling one single servo pressure to accurately control braking force. The pressure increasing characteristic is set based on the first pressure increasing characteristic obtained from the relationship between the servo pressure and the first master pressure upon increasing the servo pressure and the second pressure increasing characteristic obtained from the servo pressure and the second master pressure. The pressure decreasing characteristic is set based on the first pressure increasing characteristic obtained from the relationship between the servo pressure and the first master pressure upon decreasing the servo pressure and the second pressure decreasing characteristic obtained from the servo pressure and the second master pressure. Thus, the total braking force of the brake device is the sum of a braking force generated by the first master pressure and a braking force generated by the second master piston.

Abstract: In a braking device for a vehicle, an operating characteristics setting portion is provided for setting an operating characteristic which is a relationship between the input electric power to the electro-magnetic valve and a pressure difference between a master cylinder side and a wheel cylinder side with respect to the electro-magnetic valve, based on the input electric power at the time when the accumulator pressure detected by the accumulator pressure detecting portion first falls to a value equal to or less than a threshold value accumulator pressure by changing the input electric power towards an opening side of the electro-magnetic valve in response to a time lapsed after a predetermined value of the pilot pressure has been generated by the pilot pressure generating portion by first closing the electro-magnetic valve thereby to suppress the manufacturing cost.