Abstract: Upon occurrence of a change in the load versus fluid loss property, the braking force for the given brake pedal operation amount is changed so that the vehicle operator is enabled to perceive the change in the load versus fluid loss property. In a vehicle brake system comprising a motor actuated cylinder, wheel cylinders, a stroke sensor for detecting a brake pedal operation amount, a target value setting circuit for setting a target stoke of the motor actuated cylinder, and a fluid pressure compensating circuit for correcting the target stoke upon detection of a deviation between a brake fluid pressure reference value corresponding to the brake pedal operation amount and an actual brake fluid pressure in a direction to reduce the deviation, a stroke limiting circuit restricts a compensation value produced by the fluid pressure compensation circuit according to the brake pedal operation amount.

Abstract: Under a normal condition, brake fluid pressure generated by a slave cylinder (23) that operates according to operation of a brake pedal (12) is fed to a wheel cylinder (16, 17; 20, 21) to perform braking, while under a fault condition of the slave cylinder (23), brake fluid pressure generated by a master cylinder (11) for backup that operates by the operation of the brake pedal (12) is fed to the wheel cylinder (16, 17; 20, 21) to perform braking. In the latter case, brake fluid fed by a pump (64) is fed to the wheel cylinder (16, 17; 20, 21), before the brake fluid is fed from the master cylinder (11) to the wheel cylinder (16, 17; 20, 21) by a driver depressing the brake pedal (12). Accordingly, without leading to an increase in the stroke of the brake pedal (12), a required amount of brake fluid can be fed to the wheel cylinder (16, 17; 20, 21) to thus ensure a sufficient braking force.

Abstract: In an electric braking device that produces brake fluid pressure by driving a second slave piston in the axial direction with the driving force by a motor, a driving force transmission mechanism for transferring the driving force by the motor includes a nut that rotates upon reception of the rotational driving force by the motor, and a ball screw shaft which is engaged with the nut and is movable in the axial direction and which abuts the second slave piston. The electric braking device further includes a worn-out reducer for reducing the worn-out of a contact part between the ball screw shaft and the second slave piston.

Abstract: In a brake-by-wire vehicle brake system that uses a solenoid shut-off valve (24a, 24b), the electric power supplied to the solenoid (33) of the solenoid shut-off valve is controlled so as to decelerate a movement of a plunger (31, 32) of the valve as the plunger reaches a point immediately adjacent to a terminal point thereof. Thereby, a highly responsive property can be achieved while the noises that are generated by the plunger striking a stopper (36) or a valve seat (34) can be minimized. When actuating the plunger in the valve closing direction, the solenoid may receive electric power at a first level, a second level lower than the first level and a third level intermediate between the first and second levels in that order.

Abstract: In a BBW type vehicle brake device, first and second fluid paths that are connected to each other are both connected to a slave cylinder with a simple structure that is equipped with a single fluid pressure chamber, thereby enabling wheel cylinders having two lines to be operated and eliminating the need for a complicated tandem type slave cylinder. When the slave cylinder becomes inoperable due to malfunction of the power supply, by opening first and second master cut valves and closing the communication control valve, braking is carried out by means of brake fluid pressure generated by a master cylinder. In this process, since the interconnection between the first and second fluid paths is blocked by closing the communication control valve, even if the wheel cylinder of one of the brake lines suffers from a liquid leakage malfunction, the other remained brake line is enabled to ensure a braking force.

Abstract: A slave cylinder includes a first input port provided to a first slave hydraulic chamber and which is connected to a master cylinder and is selectively cut off from the master cylinder by a first shut-off valve; a second input port provided to a second slave hydraulic chamber and which is connected to the master cylinder and is selectively cut off from the master cylinder by a second shut-off valve; a first atmosphere port formed in a first back chamber disposed in rear of the first slave hydraulic chamber and which moves together with a first piston; a second atmosphere port formed in a second back chamber disposed in front of the first slave hydraulic chamber and which moves together with a second piston; and a restricting means to restrict the second piston. The second atmosphere port is disposed in the vicinity of the restricting means.

Abstract: In a BBW type brake device, if a slave cylinder becomes inoperable, when a master cylinder is operated for the first time, a master cut valve is opened to charge brake fluid into a reservoir of a hydraulic modulator, and since the brake fluid charged into the reservoir is increased in pressure by driving a hydraulic pump when the master cut valve is closed, wheel cylinders are operated. Since the amount of brake fluid on the downstream side relative to the master cut valve is increased by charging the reservoir with brake fluid, it is possible to increase the pressure of the brake fluid of the reservoir by driving the hydraulic pump and generate brake fluid pressure by a hydraulic modulator that is higher than the brake fluid pressure generated by the master cylinder, thereby generating sufficient braking force without increasing the depressing force applied to a brake pedal.

Abstract: Brake apparatus (10; 110; 140) includes a transmission unit (75) for operatively connecting a brake pedal (12) to a master cylinder (17), and the transmission unit is capable of varying a ratio between an output amount of a push rod (86) connected to a master cylinder (17) and a movement amount of the brake pedal (12). Further, the transmission unit (75) is constructed such that, in a latter-half operation amount region (E2; E6; E9) of the brake pedal, the ratio of the operation amount of the brake pedal to the movement amount of the push rod is controlled, via the transmission unit, to increase in response to increase of the operation amount of the brake pedal.

Abstract: The following are provided: an input device via which an operator inputs brake operations; a motor cylinder device that generates hydraulic brake pressure on the basis of electric signals based on said brake operations; and a VSA device that assists in stabilizing the behavior of the vehicle on the basis of the aforementioned hydraulic brake pressure generated by the motor cylinder device. Said input device, motor cylinder device, and VSA device are disposed, separated from each other, in an engine compartment partitioned off forwards of a dashboard.

Abstract: When brake fluid of a first wheel cylinder (39a) of a slave cylinder (23) is increased by supplying the brake fluid to a first wheel cylinder (16, 17) by a first pump (64A), a second piston (38B), which is a free piston, of the slave cylinder (23) moves toward the first fluid pressure chamber (39A) side, the volume of a second fluid pressure chamber (39B) thereby expands, and the brake fluid pressure of a second wheel cylinder (20, 21) can be reduced, whereas when brake fluid pressure of the second fluid pressure chamber (39B) is increased by supplying the brake fluid to the second wheel cylinder (20, 21) by a second pump (64B), the second piston (38B) moves toward the second fluid pressure chamber (39B) side, the volume of the first fluid pressure chamber (39A) thereby expands, and the brake fluid pressure of the first wheel cylinder (16, 17) can be reduced, thus enabling a difference in brake fluid pressure to be freely generated between the first and second wheel cylinders (16, 17).

Abstract: A structure for attaching a motor cylinder device to the body of the vehicle, said vehicle brake system including: an input device via which an operator inputs brake operations; and a motor cylinder device that generates hydraulic brake pressure on the basis of electrical signals based on said brake operations. Said motor cylinder device has: an electric motor that operates on the basis of electrical signals; a driving-force transmission unit that transmits driving force from the electric motor; and a cylinder mechanism that applies pressure to a brake fluid by moving a piston axially by means of the driving force transmitted by the driving-force transmission unit. A mount for attaching the motor cylinder device to the body of the vehicle is provided near the center of gravity of the motor cylinder device. This makes it possible to minimize displacement of the electric brake actuator when subjected to vibration.

Abstract: The following are provided: an input device via which an operator inputs brake operations; a motor cylinder device that generates hydraulic brake pressure on the basis of electric signals based on said brake operations; and a VSA device that assists in stabilizing the behavior of the vehicle on the basis of the aforementioned hydraulic brake pressure generated by the motor cylinder device. Said input device, motor cylinder device, and VSA device are disposed, separated from each other, in an engine compartment partitioned off forwards of a dashboard.

Abstract: A VSA device (24), which controls vehicle behavior by individually controlling the pressure of brake fluid supplied from a slave cylinder (23) to a wheel cylinder (16, 17; 20, 23), is provided with: an accumulator (62) which can be connected to the wheel cylinder and the slave cylinder (23); an out-valve (60, 61) disposed on a fluid path between the wheel cylinder and the accumulator (62); a check valve (63) that allows only flow of brake fluid from the accumulator (62) to the slave cylinder (23); and a regulator valve (54) disposed on a fluid path between the wheel cylinder and a path between the check valve (63) and the slave cylinder (23). Brake fluid is discharged from the accumulator (62) to the slave cylinder (23) by reducing the driving force of an electric motor (32) of the slave cylinder (23), thereby rendering a special pump unnecessary and making it possible to reduce the weight, cost, and component count.

Abstract: Upon occurrence of a change in the load versus fluid loss property, the braking force for the given brake pedal operation amount is changed so that the vehicle operator is enabled to perceive the change in the load versus fluid loss property. In a vehicle brake system comprising a motor actuated cylinder, wheel cylinders, a stroke sensor for detecting a brake pedal operation amount, a target value setting circuit for setting a target stoke of the motor actuated cylinder, and a fluid pressure compensating circuit for correcting the target stoke upon detection of a deviation between a brake fluid pressure reference value corresponding to the brake pedal operation amount and an actual brake fluid pressure in a direction to reduce the deviation, a stroke limiting circuit restricts a compensation value produced by the fluid pressure compensation circuit according to the brake pedal operation amount.

Abstract: In a brake device, when a piston (38A, 38B) of a slave cylinder (23) seizes at an advanced position, an out-valve (60, 61) is opened to discharge brake fluid in a wheel cylinder (16, 17; 20, 21) to a reservoir (62). Then, an in-valve (54, 56) and the out-valve (60, 61) are both closed, and a pump (64) is activated. This allows the brake fluid in the reservoir (62) to be supplied to a fluid pressure chamber (39A, 39B) of the slave cylinder (23), enabling a piston (38A, 38B) of the slave cylinder (23), which has seized at the advanced position, to be pushed back to a retreated position. When the seizure of the piston (38A, 38B) is eliminated in this way, the brake fluid pressure generated in the master cylinder (11) can be supplied to the wheel cylinder (16, 17; 20, 21) via the fluid pressure chamber (39A, 39B) of the slave cylinder (23). Accordingly, it is proposed a method of eliminating seizure of a slave cylinder of a brake device capable of the backup of a failure in the slave cylinder (23).

Abstract: A motor cylinder device (16) is configured with a cylinder mechanism (76) provided with first and second slave pistons that are displaced along a hydraulic pressure chamber; an electric motor (72) for driving first and second slave pistons; and an actuator housing (75) formed separable from the cylinder mechanism (76), wherein the actuator housing houses a gear mechanism for transmitting a rotational driving force of the electric motor (72), and a conversion mechanism for converting the rotational driving force transmitted through the gear mechanism, into a linear movement and transmitting the linear movement to the piston.

Abstract: An input device of a vehicle brake system integrally includes an integrally provided master cylinder and a stroke simulator which communicate via a hydraulic communication path. The stroke simulator is provided with a simulator piston accommodated within a simulator accommodation chamber. The simulator accommodation chamber has an opening portion enabling the insertion of the simulator piston into the simulator accommodation chamber from the side on which the brake pedal is disposed relative to the dashboard.

Abstract: An input device of a vehicle brake system which is downsized and has an improved general versatility in comparison with conventional vehicle brake systems is provided. An input device 14 includes: a master cylinder 34 that produces a fluid pressure in accordance with an input of an operation of a brake operating member 12; and a stroke simulator 64 which is provided side by side with the master cylinder 34 and which applies in a pseudo manner a force counteracting the operation of the brake operating member 12 to the brake operating member 12. The master cylinder 34 and the stroke simulator 64 are formed integrally.

Abstract: There is provided a vehicle brake system to which an electric brake actuator constituting the vehicle brake system is stably attached and in which it is possible to dispose the electric brake actuator in a power plant storage chamber in a space-efficient manner. A vehicle brake system configured by disposing, on a vehicle, an input device to which the brake operation of an operator is inputted and a motor cylinder device for generating brake fluid pressure by driving a hydraulic pressure controlling piston stored in a cylindrical cylinder main body by means of an electric motor at least in accordance with the brake operation, wherein the motor cylinder device is attached in a manner such that at least a portion of the cylinder main body overlaps with a power plant in the vehicle up and down direction; and the electric motor is disposed below the cylinder main body.

Abstract: A slave cylinder includes a first input port provided to a first slave hydraulic chamber and which is connected to a master cylinder and is selectively cut off from the master cylinder by a first shut-off valve; a second input port provided to a second slave hydraulic chamber and which is connected to the master cylinder and is selectively cut off from the master cylinder by a second shut-off valve; a first atmosphere port formed in a first back chamber disposed in rear of the first slave hydraulic chamber and which moves together with a first piston; a second atmosphere port formed in a second back chamber disposed in front of the first slave hydraulic chamber and which moves together with a second piston; and a restricting means to restrict the second piston. The second atmosphere port is disposed in the vicinity of the restricting means.