Disclosed are a vehicle braking system and a control method thereof, which are a vehicle braking system capable of detecting an offset of a pressure sensor regardless of whether a brake pedal is provided, and a control method thereof, including a first brake device, a first pressure sensor for measuring an internal pressure of the first brake device; and a first offset determinator for determining that an offset has occurred in the first pressure sensor when a first cut valve provided in the first brake device is opened and the state in which a measurement of the first pressure sensor exceeds a first reference pressure is maintained for more than a first reference time.

A method for operating a brake system for motor vehicles, comprising a master brake cylinder actuable by a brake pedal, an electrically controllable pressure provision device, a pressure medium reservoir tank, from which the master brake cylinder and the pressure provision device are supplied with pressure medium, and at least two hydraulically actuable wheel brakes and at least one electrically actuable inlet valve per wheel brake, wherein the wheel brakes are actuable either by the master brake cylinder or by the pressure provision device, the pressure medium reservoir tank is monitored by a device for determining a level of the pressure medium, wherein the wheel brakes are divided into at least one first wheel brake group and one second wheel brake group, and wherein the inlet valves of the first wheel brake group are closed when the determined level falls below a first limit value (s.sub.1).

In a hydraulic brake system, when a main power supply is in an abnormal condition in which it cannot supply electric power to a pump motor, etc., the pump motor is operated with electric power supplied from an auxiliary power supply, irrespective of the presence of a braking request. Thus, when the main power supply is in the abnormal condition, the number of times inrush current flows is reduced. As a result, the voltage of the auxiliary power supply is less likely to be lower than an operation minimum voltage, and the hydraulic brake system is less likely to be unable to be operated.

An electro-hydraulic brake system comprises a single-circuit master cylinder (MC) fluidly coupled to a first MC fluid passageway and configured to supply fluid into the first MC fluid passageway in response to pressing force on a brake pedal coupled thereto. The electro-hydraulic brake system also comprises a pressure supply unit (PSU) assembly including an electric motor coupled to a ball screw actuator, a PSU housing defining a piston bore having a terminal end opposite the electric motor, and a PSU piston disposed within the piston bore and movable by the ball screw actuator through the piston bore and dividing the piston bore into a first chamber and a second chamber, with each of the first chamber and the second chamber containing a hydraulic fluid. The ball screw actuator includes an actuator nut assembly having a plurality of ball bearings each disposed within the piston bore and submerged in the hydraulic fluid.

A braking control device, when stopping a vehicle in a state where a braking force is being applied to the vehicle, executes a reducing control of reducing the braking force corresponding to a braking request before the vehicle stops and executes an increasing control of increasing the braking force corresponding to the braking request before the reducing control in order to suppress vehicle pitching behavior generated when the braking force is applied to the vehicle. The control device sets braking force increase amount in the increasing control based on a difference distance that is a difference between a first distance correlated with a vehicle traveling distance from a reduction start timing when the reducing control is executed until the stopping of the vehicle and a second distance correlated with a vehicle traveling distance from the reduction start timing when the reducing control is not executed until the stopping of the vehicle.

A braking control device includes a “master cylinder CM capable of pressure feeding brake fluid BF in conjunction with the movement of a brake operating member BP of a vehicle”, an “electrically driven fluid unit HU”, “front wheel and rear wheel cylinders CWf, CWr that are provided on the front wheel and rear wheel WHf, WHr of the vehicle and are pressurized by either one of the master cylinder CM and the fluid unit HU”, and a “controller ECU that controls the fluid unit HU”. The controller ECU determines whether or not external leakage of a brake fluid BF has occurred in the braking control device, and when the external leakage has occurred, pressurizes the front wheel cylinder CWf by the master cylinder CM, and pressurizes the rear wheel cylinder CWr by the fluid unit HU.

A vehicle braking device includes a first supply device that supplies brake fluid to wheel cylinders, a first supply path that connects the first supply device and the wheel cylinders, and first and second electromagnetic valves provided on the first supply path. The first electromagnetic valve is disposed on the first supply path such that a seating direction of the first electromagnetic valve and a brake fluid supply direction are opposite each other, the seating direction is a direction in which a valve body is seated on a valve seat, and the brake fluid supply direction is a direction in which the brake fluid flows from the first supply device to the wheel cylinders through the first supply path. The second electromagnetic valve is disposed on the first supply path such that a seating direction of the second electromagnetic valve and the brake fluid supply direction are the same.

The present invention comprises: a piston provided in a cylinder hole; a lid member which closes an opening on the other side of the cylinder hole; and elastic members and which are provided between the piston and the lid member. The elastic members and comprise a first elastic member provided on the piston side of the cylinder hole, and a second elastic member provided on the lid member side of the cylinder hole. The second elastic member has a base portion provided in line with the first elastic member, and a protruding portion protruding from the piston side end surface of the base portion. When the piston has moved in the axial direction to the lid member side, the protruding portion touches the piston, undergoing compressive deformation, and the base portion subsequently undergoes compressive deformation.

A simulator valve includes a housing having a pedal simulator passage and a master cylinder passage extending therethrough. The master cylinder passage is located longitudinally between the first housing surface and the pedal simulator passage. An armature is located at least partially within the housing for selective longitudinally reciprocating motion with respect thereto between first and second armature positions. A poppet is located within the housing for selective longitudinally reciprocating motion with respect thereto between first and second poppet positions. The poppet defines a first valve and a second valve the poppet includes a poppet bore extending longitudinally therethrough and selectively occluded by the first valve. A damped flow fluid path selectively permits fluid communication therethrough from the master cylinder passage to the pedal simulator passage. A free flow fluid path selectively permits fluid communication therethrough from the pedal simulator passage to the master cylinder passage.

A method for checking functionality of a motor vehicle braking system. The braking system has a main module, including: hydraulically actuatable wheel brakes, pairs being assigned to respective brake circuits; at least one electrically actuatable wheel valve per wheel brake sets wheel-specific brake pressures; a pressure provision device actively builds up pressure in the wheel brakes; a pressure-medium reservoir at atmospheric pressure, and an auxiliary module, which has for each of two wheel brakes: a pressure sensor for measuring pressure in a wheel brake line; an open when deenergized isolating valve in the wheel brake line; a pump. At least one variable is measured to assess functionality of the braking system. Using least one acceptance criterion, and checked whether the variable satisfies the acceptance criterion. Determining at least one variable representing the viscosity of the brake fluid, and the at least one acceptance criterion depends on a variable representing viscosity.