Abstract: A vehicle brake system includes a cylinder, a master piston including a pressure applying piston and a projection portion, a servo chamber, a contact/separation determining means determining a separated state and a contact state between the input piston and the master piston, a pilot pressure generating device generating a pilot pressure, a servo pressure generating device, a servo pressure measuring device measuring a servo pressure, and a master pressure estimating means estimating a master pressure from the pilot pressure and a first servo ratio, which is a cross-sectional area ratio between a first pilot chamber and a servo pressure generating chamber, in a case of the separated state, and estimating the master pressure based on the servo pressure, the pilot pressure and a second servo ratio, which is a cross-sectional area ratio between a second pilot chamber and the servo pressure generating chamber, in a case of the contact state.

Abstract: The brake ECU applies the target braking force by controlling the hydraulic pressure braking force generating device and the regeneration braking force generating device and the brake ECU further controls the advance speed of the output piston so that a drawn-into of a brake operating member can be prevented upon supplying the wheel cylinders from the master cylinder with the brake fluid by advancing the output piston thereby to improve the brake operating feeling of the brake operating member by preventing the brake operating member from being drawn into.

Abstract: When a brake ECU is started up rapidly by a brake pedal operation, the brake ECU executes a depression force fluid pressure mode. When the control pressure detected by a control pressure sensor becomes smaller than a switching determination threshold value, the brake ECU determines that an operation of returning a brake pedal is being performed, and switches the braking mode from the depression force fluid pressure mode to a normal control mode. Accordingly, even when the operation of a stroke simulator has been started, no uncomfortable feeling is given to a driver. Further, even when the operation of returning the brake pedal is not being performed, the braking mode is switched from the depression force fluid pressure mode to a simulator non-operation control fluid pressure mode when a vehicle starts to travel. Consequently, desired braking force can be rapidly generated.

Abstract: The vehicle braking device has a hydraulic braking force generating device, a regeneration braking force generating device, a braking operation amount detection portion and a required braking force calculation portion. The vehicle braking device controls the hydraulic braking force generating device and the regeneration braking force generating device so as to apply the required braking force to the wheels. The vehicle braking device has a braking force adjustment control portion for executing braking force adjustment control for limiting the rate at which the regeneration braking force is increased and increasing the hydraulic braking force before the current regeneration braking force reaches a maximum regeneration braking force, that is, the maximum braking force that can be generated by the regeneration braking force generating device.

Abstract: The vehicle braking control device adapted to a vehicle brake device having an electromagnetic valve which controls the brake fluid flow between the master cylinder and the wheel cylinders in response to the input electric energy. The vehicle braking control device includes a valve opening electric energy obtaining portion which obtains an input electric energy upon opening of the electromagnetic valve as a valve opening electric energy and an operation characteristic setting portion which sets an operation characteristic based on the valve opening electric energy obtained corresponding to the predetermined pressure differential. The opening valve electric energy obtaining portion changes the input electric energy at a valve closing side or a valve opening side with a change amount per unit of time larger than before valve opening in response to an obtaining of the valve opening electric energy.

Abstract: A hydraulic brake system includes: a brake hydraulic-pressure control device capable of controlling a hydraulic pressure in a brake cylinder of a hydraulic brake configured to reduce a rotation of a wheel, the brake hydraulic-pressure control device including (i) a piston, (ii) a hydraulic-pressure chamber provided opposite the piston, and (iii) a moving-force control device configured to apply a moving force to the piston and capable of controlling the moving force; and an air reducing device configured to control the moving-force control device to move the piston to reduce air in an air reduction target portion including the hydraulic-pressure chamber.

Abstract: The vehicle brake system includes a cylinder, an output piston disposed in the cylinder, an input piston disposed in the cylinder but separating from the output piston and defining a separation chamber therebetween, a brake pedal connected to the input piston, a reaction force generating device for generating an elastic reaction force, a separation lock valve for controlling the communication between the separation chamber and the reaction force generating device, a fade state judging portion to judge whether the friction brake device is in a fade state or not and a friction braking force control portion for changing the mode to the fade state when the fade state judging portion judged that the friction brake device is in the fade state, wherein a desired friction braking force can be assured even under the brake fade state.

Abstract: A brake control device for a vehicle which can prevent occurrence of hunting or stepping during braking control operation and includes a pressure increasing or decreasing characteristic selecting portion which selects a pressure increasing characteristic when a target wheel cylinder pressure increases continuously for a predetermined operation judgment period and selects a pressure decreasing characteristic when the target wheel cylinder pressure decreases continuously for a predetermined operation judgment period. The brake control device further includes an output servo pressure setting portion which sets a target servo pressure based on the pressure increasing or decreasing characteristic selected by the pressure increasing or decreasing characteristic selecting portion and a servo pressure generating device which generates a servo pressure based on the target servo pressure.

Abstract: When a brake switch is switched from OFF to ON, current is applied to a brake ECU, and a command to switch a master cylinder from a second state to a first state is issued after a lapse of preparation time, so that switching-time change suppression control is performed. A reservoir shutoff valve is closed, and duty control is performed on a communication control valve. The duty ratio is set to 1 when a switching-time control duration expires, and the communication control valve is placed in an open position, to establish the first state. Thus, since the communication control valve is duty-controlled during switching from the second state to the first state, change in the hydraulic pressure of an input chamber is suppressed, and change of the operating feeling is suppressed.

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: A hydraulic brake system is configured such that a pressure of a working fluid from a high-pressure-source device is adjusted by electromagnetic pressure-increase and pressure-decrease linear valves and such that a brake device generates a braking force having a magnitude that depends on the pressure adjusted by the linear valves, wherein the following controls are selectively executable, as a control of the energizing currents supplied to the linear valves, a feedback control based on a difference between an actual braking-force index and a target braking-force index; and a feedforward control based on the target braking-force index executed by placing each valve in a valve equilibrium state, wherein, in the feedforward control, an energizing current is supplied to at least one of the two linear valves, the energizing current being larger than that according to a preset relationship between a braking-force index and an energizing current in the valve equilibrium state.

Abstract: A hydraulic braking system includes: a cylinder device including a pressurizing piston, a rear chamber, and a front pressure chamber on opposite sides of the pressurizing piston; a brake cylinder coupled to the front pressure chamber; a regulator including a control piston, an input chamber provided at a rear of the control piston, and an output chamber coupled to the rear chamber in front of the control piston; and an input-hydraulic-pressure control device including a high-flow-rate supply unit configured, when an operation of the regulator is started, to supply the working fluid to the input chamber at a set flow rate; and a low-flow-rate supply unit configured, when the supply is finished, to supply the working fluid to the input chamber at a flow rate less than the set flow rate.

Abstract: A hydraulic-pressure control device includes: a regulator (182) including a housing (200), a control piston (204) in the housing (200); an input chamber (212) at a rear of the control piston (204) and an output chamber (214) in front of the control piston (204); and an input-hydraulic-pressure control device (56,184) which controls hydraulic pressure in the input chamber (212) to move the control piston (204) forward or backward to raise or reduce hydraulic pressure in the output chamber (214).

Abstract: A hydraulic brake system includes: a master cylinder including a pressurizing piston; a brake cylinder for a hydraulic brake operable by a hydraulic pressure in a front pressure chamber defined in front of the pressurizing piston; and a rear-hydraulic pressure controller connected to a rear chamber defined at a rear of the pressurizing piston. The rear-hydraulic pressure controller controls a hydraulic pressure in the rear chamber and includes: a regulator, operable by at least one of the hydraulic pressure in the front pressure chamber and a control pressure controlled electrically, for supplying an output hydraulic pressure to the rear chamber; and a master-pressure-operating-state detector configured to, when the output hydraulic pressure is greater than a threshold value, detect that the regulator is in a master-pressure operating state in which the regulator is operated by at least the hydraulic pressure in the front pressure chamber.

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.

Abstract: A vehicle brake system includes a cylinder, a master piston including a pressure applying piston and a projection portion, a servo chamber, a contact/separation determining means determining a separated state and a contact state between the input piston and the master piston, a pilot pressure generating device generating a pilot pressure, a servo pressure generating device, a servo pressure measuring device measuring a servo pressure, and a master pressure estimating means estimating a master pressure from the pilot pressure and a first servo ratio, which is a cross-sectional area ratio between a first pilot chamber and a servo pressure generating chamber, in a case of the separated state, and estimating the master pressure based on the servo pressure, the pilot pressure and a second servo ratio, which is a cross-sectional area ratio between a second pilot chamber and the servo pressure generating chamber, in a case of the contact state.

Abstract: In a hydraulic brake system including a cylinder device that includes a front chamber and a rear chamber located on front and rear sides of a pressurizing piston, respectively, presence or absence of liquid leakage from a brake line is detected based on a hydraulic pressure in the rear chamber. Where a state in which a subtraction value obtained by subtracting an actual rear hydraulic pressure from a target rear hydraulic pressure is larger than a first malfunction determination threshold value has continued for a time not shorter than a first malfunction determination time, and then an increase of the actual rear hydraulic pressure at a rate not lower than a set rate has caused the subtraction value to become smaller than a return determination threshold value, it is determined that the pressurizing piston has been bottomed due to liquid leakage from the front chamber.

Abstract: An indicator drive circuit includes a current mirror circuit including a first transistor located at a control side and a second transistor located at a controlled side, a current through the current mirror circuit being switched by an external control signal, a current source adapted to feed a control current to the first transistor of the current mirror circuit, and a switching element adapted to be driven by a current through the second transistor of the current mirror circuit and to switch on or off an indicator light source. The current source includes two transistors cascode-connected.

Abstract: When a brake ECU is started up rapidly by a brake pedal operation, the brake ECU executes a depression force fluid pressure mode. When the control pressure detected by a control pressure sensor becomes smaller than a switching determination threshold value, the brake ECU determines that an operation of returning a brake pedal is being performed, and switches the braking mode from the depression force fluid pressure mode to a normal control mode. Accordingly, even when the operation of a stroke simulator has been started, no uncomfortable feeling is given to a driver. Further, even when the operation of returning the brake pedal is not being performed, the braking mode is switched from the depression force fluid pressure mode to a simulator non-operation control fluid pressure mode when a vehicle starts to travel. Consequently, desired braking force can be rapidly generated.

Abstract: The present invention relates to a vehicle brake device which can secure the durability of a linear valve for controlling a servo pressure. The brake ECU of the vehicle brake device sets a reference servo pressure based on the operating amount of a brake pedal when the vehicle is stopped and sets a target servo pressure based on the reference servo pressure during one braking operation. Further, the brake ECU sets the reference servo pressure based on the operating amount of the brake pedal when the servo pressure calculated in response to the operating amount of the brake pedal exceeds the servo pressure change threshold value set with a deviation from the reference servo pressure calculated in response to the brake pedal operating amount.