Abstract: A brake control mounted in a vehicle equipped with a regenerative generator on either the front wheels or the rear wheels including a first pressure adjusting unit that adjusts a liquid pressure generated by a first electric motor to a first liquid pressure and provides the first liquid pressure to wheel cylinders of wheels on one side; and a second pressure adjusting unit that is configured by a fluid pump, which is driven by a second electric motor, and a pressure adjusting valve, and that performs adjustment to increase the first liquid pressure to a second liquid pressure and provides the second liquid pressure to wheel cylinders of wheels on the other side.

Abstract: A pedal emulator (20, 100) is provided. The pedal emulator includes an emulator piston (28, 102) coupled to a damper (46, D1) that is contained within a housing (22, 104). The damper is surrounded by first (34, S1) and second (38, S2) springs that are carried by a lower spring seat (114), the lower spring seat being upwardly biased by a third spring (S3), for example a wave spring. The first and second springs and the third spring cooperate to provide a counter-force that is tailored to the desired feel of the pedal. First and second sensors measure travel (72, 74) and force in response to downward compression of the emulator piston, and the damper provides hysteresis upon return travel of the emulator piston.

Abstract: A cuboid hydraulic block for a slip-controlled hydraulic power vehicle braking system and provides applying ports for wheel brakes along a transverse side or along a longitudinal side in a large side of the hydraulic block.

Abstract: Disclosed herein is an electronic brake system. The electronic brake system includes a hydraulic pressure supply apparatus generating a hydraulic pressure by moving a piston forward or backward with a rotational force of a motor, and supplying the generated hydraulic pressure to wheel cylinders provided at wheels, respectively; a wheel speed sensor detecting speed of each of the wheels; a piston position detector detecting a position of the piston; and an ECU configured to calculate a piston displacement amount with respect to a vehicle speed change amount during an ABS operation; calculate an actual stroke of the piston; estimate a position of the piston at an entry time point of a preset low speed section; estimate a moving direction remaining stroke; and determine whether to change the moving direction of the piston in advance before entering the preset low speed section.

Abstract: A method for controlling a brake booster in a hydraulic brake system, in which the smallest partial pressure target value of at least three partial pressure target values is ascertained, and is then defined as the target pressure value and is then set using a brake booster.

Abstract: A brake actuation unit (1) having a master brake cylinder (2) and a pressure-medium reservoir (4); a pressure provision device (5), having a piston (51) actuated by an electric motor (35), wherein the piston delimits a pressure chamber (50); first and second groups of electrically actuatable valves (6a-6d, 7a-7d); and an electronic control unit (12, 12?). The electric motor has at least two independently operable drive units, each having at least one winding, for driving the electric motor. The electronic control unit has a first microcontroller (201) and a second microcontroller (301). The first microcontroller controls (205) one of the drive units and the second microcontroller controls (305) the other of the drive units. The first and second microcontrollers control (207, 307) the second group of valves.

Abstract: An electric brake system is disclosed.

Abstract: An electric brake system includes a hydraulic pressure supply device configured to generate hydraulic pressure using a piston which is operated by an electrical signal that is output corresponding to a displacement of a brake pedal, and including a first pressure chamber and a second pressure chamber, a first hydraulic flow path configured to communicate with the first pressure chamber, a second hydraulic flow path configured to communicate with the first pressure chamber, a third hydraulic flow path configured to communicate with the second pressure chamber, a fourth hydraulic flow path branching from the third hydraulic flow path and connected to the first hydraulic flow path, a fifth hydraulic flow path branching from the third hydraulic flow path and connected to the second hydraulic flow path.

Abstract: The present invention relates to a braking device and to a braking system, each having a master brake cylinder (10) having at least one first pressure chamber (12) that is subdivided or is able to be subdivided at least into a first partial volume (12a) and a second partial volume (12b), which are hydraulically connectable or connected to a brake fluid reservoir (24), a first brake circuit (28) being hydraulically connectable or connected to the first partial volume (12a), and having a valve device (38) that is mechanically designed in such a way that a pressure buildup up to a mechanically specified limit pressure may be brought about in the second partial volume (12b), brake fluid being transferable at least into the first brake circuit (28) via at least one subcomponent (38a) of the valve device (38), and an exceeding of the limit pressure in the second partial volume (12b) being prevented.

Abstract: An electronically slip-regulated vehicle brake system is configured to change from an external force powered operating brake mode into a muscle-powered auxiliary brake mode, and includes a master brake cylinder configured to be operated, a pedal travel simulator configured to simulate an operating travel of the master brake cylinder during the operating brake mode, and a simulator control valve. The simulator includes two pressure chambers. The control valve is configured to control a flow of pressure medium into a first of the two pressure chambers from the master brake cylinder, and is disposed in a return line connecting a wheel brake to a reservoir tank at a position downstream of a connection point at which a second of the two pressure chambers of the simulator is connected to the return line.

Abstract: A hydraulic unit for a slip control system of a hydraulic vehicle brake system comprises a hydraulic block including a socket, a first port, a pressure change damper, and a second port. The socket has a base and defining a first interior. The first port is located at the base of the socket. The pressure change damper defines a second interior and is positioned in the socket in engagement with the first port. The first port is in fluidic communication with the second interior. The second port is in fluidic communication with the second interior via a portion of the first interior outside of the pressure change damper.

Abstract: A method for checking an isolation valve of a braking system of a vehicle includes the steps of: operating at least one pump of a brake circuit of the braking system which is hydraulically connected via the isolation valve to a brake master cylinder of the braking system for a predefined pump running time; measuring at least one value regarding a pressure present in the brake circuit; and determining, in consideration of the at least one measured value, whether the isolation valve is mechanically blocked.

Abstract: A method for controlling a pneumatic braking system of a utility vehicle that includes a service brake and an electric parking brake, an electronic control unit being provided for controlling the electric parking brake. The parking brake assists a brake intervention of the utility vehicle when there is a circuit failure of the service brake.

Abstract: A pump housing has at least two inlet valve openings located in a first row, at least two outlet valve openings located in a subsequent second row, and at least one high-pressure switching valve opening and at least one changeover valve opening located in a further subsequent fourth row. At least one connection for a wheel pressure sensor is positioned in a third row between the second and fourth rows. At least one connection for a master cylinder pressure sensor is positioned in a fifth row following the fourth row.

Abstract: A pressure regulator configured to regulate a working fluid by a pilot pressure, including: a spool valve mechanism having a spool; a biasing mechanism having a pilot-pressure chamber and a pilot piston, the biasing mechanism being configured to bias the spool toward the other end of the pressure regulator in its axial direction by a pressure of the working fluid in the pilot-pressure chamber; a counter biasing mechanism having a regulated-pressure chamber and a counter biasing piston, the counter biasing mechanism being configured to bias the spool toward one end of the pressure regulator in the axial direction by a pressure of the working fluid in the regulated-pressure chamber; and at least one of a first damping mechanism configured to damp a movement of the pilot piston and a second damping mechanism configured to damp a movement of the counter biasing piston.

Abstract: A method of controlling an auxiliary pump for supplying the hydraulic fluid of a hybrid transmission of a vehicle. The auxiliary pump, after the expiration of a predetermined time interval of deactivation, is activated to prevent accumulation of air in the intake area of the auxiliary pump. In addition, a device for the execution of the method, in which a control device is provided which has its signals connected with the electric auxiliary pump for the purpose of controlling the auxiliary pump in order to prevent accumulation of air in the intake area of the auxiliary pump.

Abstract: A brake control device includes a front-wheel left-right communication passage that allows communication between wheel cylinders for a front-left wheel and a front-right wheel via a front-wheel communication on-off valve, and a rear-wheel left-right communication passage that allows communication between wheel cylinders for a rear-left wheel and a rear-right wheel via a rear-wheel communication on-off valve. The brake control device executes a hydraulic control by keeping the front-wheel communication on-off valve and the rear-wheel communication on-off valve opened. The front-wheel communication on-off valve is a normally closed type, and the rear-wheel communication on-off valve is a normally opened type.

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: A pressure regulator configured to regulate a working fluid by a pilot pressure, including: a spool valve mechanism having a spool; a biasing mechanism having a pilot-pressure chamber and a pilot piston, the biasing mechanism being configured to bias the spool toward the other end of the pressure regulator in its axial direction by a pressure of the working fluid in the pilot-pressure chamber; a counter biasing mechanism having a regulated-pressure chamber and a counter biasing piston, the counter biasing mechanism being configured to bias the spool toward one end of the pressure regulator in the axial direction by a pressure of the working fluid in the regulated-pressure chamber; and at least one of a first damping mechanism configured to damp a movement of the pilot piston and a second damping mechanism configured to damp a movement of the counter biasing piston.

Abstract: A pressure regulator configured to regulate a working fluid by a pilot pressure, including: a spool valve mechanism having a spool; a biasing mechanism having a pilot-pressure chamber and a pilot piston, the biasing mechanism being configured to bias the spool toward the other end of the pressure regulator in its axial direction by a pressure of the working fluid in the pilot-pressure chamber; a counter biasing mechanism having a regulated-pressure chamber and a counter biasing piston, the counter biasing mechanism being configured to bias the spool toward one end of the pressure regulator in the axial direction by a pressure of the working fluid in the regulated-pressure chamber; and at least one of a first damping mechanism configured to damp a movement of the pilot piston and a second damping mechanism configured to damp a movement of the counter biasing piston.

Abstract: A flow control valve (15) for a direct injection pump (10) has an inlet end (12), an inlet valve (26), a compression chamber (48), a pump piston (14), and an outlet (13). The valve (15) has a housing (16) and a non-electrically operated control plunger (22) movable within the housing. The control plunger engages with and disengages from the inlet valve to control opening and closing of the inlet valve. A spring (28) biases the control plunger away from the inlet valve. The pump and housing define port structure (38, 44) fluidly connecting the outlet with a volume (42) that communicates with the control plunger such that when fluid pressure at the outlet is greater than a certain value, the fluid pressure in the volume alone causes the control plunger to move against the spring and engage the inlet valve to hold the inlet valve in an open position.

Abstract: A brake system for motor vehicles of “brake-by-wire” type without a brake booster, having a hydraulic activation device which can be activated by means of a brake pedal and to which wheel brakes are connected, and a simulation device which can be activated hydraulically and has at least one elastic element which gives the driver of a vehicle a pleasant pedal sensation is intended to have a functional capacity which can be checked during the normal braking function and to give the driver a pedal sensation which is familiar from a conventional hydraulic brake system. For this purpose, the activation device is connected via a hydraulic connection to the simulation device, wherein the hydraulic connection is connected via an electrically controllable check valve to a pressure medium reservoir which is at atmospheric pressure.

Abstract: A vehicle braking system includes a slip control system operable in an electronic stability control (ESC) mode to automatically and selectively apply the brakes in an attempt to stabilize the vehicle when an instability condition has been sensed. The slip control system is further operable in an adaptive cruise control (ACC) mode to automatically apply the brakes to slow the vehicle in response to a control signal. The slip control system includes a variable speed motor drive piston pump for supplying pressurized fluid pressure to the brakes through a valve arrangement. In the ESC mode, the pump motor operates in an ESC speed range, and in the ACC mode, the pump motor operates in an ACC speed range lower than the ESC speed range. The slip control system further includes an attenuator connected to a pump outlet for dampening pump output pressure pulses prior to application to the brakes. The attenuator includes an elastomeric member located in an attenuator chamber of a housing.

Abstract: Provided is a braking control system including: an internal combustion engine serving as a power source of a vehicle; a brake servo unit operated by a negative pressure supplied thereto; a passage configured to supply an intake negative pressure of the internal combustion engine to the brake servo unit; and a negative pressure pump configured to generate a negative pressure by being driven by power transmitted from a wheel of the vehicle and transmit the generated negative pressure to the brake servo unit, wherein the negative pressure pump is driven so as to supply the negative pressure to the brake servo unit during execution of inertia running in which the internal combustion engine stops and the vehicle runs by inertia.

Abstract: A vehicle brake control device includes a master cylinder, a plurality of wheel cylinders, a VDC brake hydraulic pressure unit, a motor controller and an integration controller. When a brake operation is carried out, the integration controller carries out a regenerative brake control which achieves a target deceleration. Additionally, a motor suspension control is carried out which suspends a drive status of the VDC motor when the vehicle velocity is less than a first prescribed value. Furthermore, when the vehicle velocity exceeds a second prescribed value and the brake operation is carried out while the VDC motor is in the suspended status, the value of the target deceleration is set to a lower value than the value of the target deceleration which the driver requests, and a motor reactivation control is carried out which reactivates the VDC motor.

Abstract: A brake apparatus including a housing with a fluid passage, a piston body disposed within a closed-ended bore of the housing and communicated with the fluid passage, a first elastic member biasing the piston body toward a closed end of the bore, a valve element disposed in the fluid passage, a seat portion coming into contact with the valve element, a rod disposed between a crown surface of the piston body and the valve element, a second elastic member biasing the valve element toward the seat portion, a rod supporting hole portion that supports one end side of the rod, a rod outer circumferential passage portion disposed on the other end side of the rod and having an inner diameter larger than an inner diameter of the rod supporting hole portion, and at least one communicating hole portion that communicates the rod outer circumferential passage portion and the bore.

Abstract: A method for controlling a motor vehicle electrohydraulic braking system. The method being activatable in a “brake-by-wire” operating mode, having a pressure supply device (2), which can be activated by an electronic control and a regulation unit, can be connected to a hydraulically actuatable wheel brake. Wherein the pressure supply device (2) is formed by a cylinder-piston assembly (43). The piston (45) can be actuated by an electromechanical actuator (44), the control unit carries out the steps of determining a pressure target value (PV,Soll) for the pressure supply device (2), performing a pressure control operation or an actuator position control operation on the pressure supply device (2) in accordance with the magnitude of the pressure target value (PV,Soll).

Abstract: A method is provided that includes determining a state of a vehicle ignition switch; determining a state of the vehicle, wherein the vehicle state including at least one of whether the vehicle is in a torque producing mode, whether the vehicle is moving, and whether the vehicle brake system is engaged; and, controlling the vacuum pump in response to the vehicle state and the ignition switch state.

Abstract: A service brake device of a vehicle, including at least one ABS pressure control valve which is controlled for slip-regulated braking by an electronic control unit, has at least one inlet valve and one outlet valve and is arranged upstream of a pressure medium actuated brake cylinder, a pressure medium line which supplies the ABS pressure control valve with pressure medium and into which a pressure controlled by a valve device arranged upstream of the ABS pressure control valve is feedable, wherein the valve device feeds a pressure derived from a reservoir pressure of a pressure medium reservoir into the pressure medium line as a function of an activation by the electronic control unit.

Abstract: The invention relates to a hydraulic brake system comprising a master brake cylinder the at least one working chamber of which is connected to the wheel brakes of the vehicle via at least one hydraulic line, the brake piston of at least one wheel brake being adjustable by a negative pressure in the hydraulic lines to produce a brake clearance.

Abstract: Provided are a vehicle braking system and a master cylinder which are capable of providing a good pedal feel. A valve-opening pressure for a pressure-reducing valve of the master cylinder is set higher than a hydraulic pressure which is obtained with a pressing force on a brake pedal being 500 N and lower than a hydraulic pressure obtained at a time when a booster reaches a full-load point in case of failure of the booster so as to be specialized for improving pedal feel. Required performance in case of failure of the booster is realized by a pressure-intensifying unit.

Abstract: A brake apparatus including a piston body disposed in a closed-ended bore in a housing, a first elastic member biasing the piston body toward a closed end of the bore, and a pressure regulating valve including a valve element, a rod and a second elastic member biasing the valve element toward a seat portion and having an elastic force smaller than that of the first elastic member, the brake apparatus having a reservoir function of reserving brake fluid flowed from a vehicular wheel cylinder in the bore by strokes of the piston body upon ABS control, the piston body being a resin-molded member having a hard member on a piston crown surface, the hard member having a hardness larger than that of a resin material of the piston body, and the piston body and the rod are brought into contact with each other via the hard member.

Abstract: A brake booster for use in a hydraulic braking system having a brake pedal, a master cylinder, and a hydraulic control unit includes a housing, a screw drive arrangement positioned at least partially in the housing, a motor coupled to the housing for actuating the screw drive arrangement, and a piston assembly positioned in the housing. The piston assembly and the housing together at least partially define a first fluid chamber having an opening for providing fluid communication with the master cylinder, and a second fluid chamber having an opening for providing fluid communication with the hydraulic control unit. The screw drive arrangement is movable relative to a piston of the piston assembly between an engaged position, in which the first fluid chamber is isolated from the second fluid chamber, and a disengaged position in which the first fluid chamber is not isolated from the second fluid chamber.

Abstract: A vehicular braking apparatus including a shut-off valve for shutting off, as needed, a flow of oil from a wheel cylinder to a master cylinder; a pressure increase-decrease control valve increasing and decreasing a pressure in the wheel cylinder; a reservoir receiving and storing in a reservoir chamber the oil from the wheel cylinder when the pressure increase-decrease control valve is in a pressure decrease position; a pump sucking in and pressuring the oil from the reservoir chamber and supplying the oil to the wheel cylinder via the pressure increase-decrease control valve when the pressure increase-decrease control valve is in a pressure increase position; and a communication control valve controlling communication between the master cylinder and the reservoir chamber. The communication control valve is a normally-closed valve and is opened by a suction pressure of the pump.

Abstract: To provide an ABS control system and software with an automatic parameter calibration function. An ABS control system according to the present invention includes an electronic control unit (ECU), a wheel speed sensor, and a brake pressure sensor. The wheel speed sensor and the brake pressure sensor measure wheel speed and brake pressure during ABS braking, and the ABS control system automatically calibrates an internal parameter used in ABS control in response to the wheel speed and brake pressure measurement results.

Abstract: A braking control system includes sensors for detecting pressure applied to a brake pedal. The system can also include a pressure sensor capable of detecting the hydraulic pressure of the braking system. The system can also include a position sensor for detecting a position of the brake pedal. The pressure applied to the brake pedal is compared to either the hydraulic pressure or the pedal position. If the resulting measurements are not correlated properly, braking countermeasures are applied. Braking countermeasures can include engine braking, regenerative braking, hydraulic assist, and brake pad assist.

Abstract: A device and method for a hydraulic brake system of a land vehicle in order to block a brake circuit of the brake system with regard to a supply of brake pressure generated by a driver, to establish a hydraulic connection between the output side of a wheel brake and the input side of a controllable pump and to generate a predetermined brake pressure at the input side of the wheel brake by the use of a pump.

Abstract: A brake system for motor vehicles having a brake master cylinder that can be operated by a brake pedal, a fluid reservoir assigned to the brake master cylinder, a hydraulic booster stage which is operatively connected to the inlet side of the brake master cylinder, with a booster piston which is subjected to a hydraulic boost pressure supplied by a pressure source and which in all operating modes allows a direct mechanical action by the brake pedal on a hydraulic piston of the brake master cylinder, and having an electrically controllable pressure regulating valve arrangement for metering the boost pressure. In order to provide a brake system of simple design, which is cost-effective to produce and which functions reliably, the pressure regulating valve arrangement can be hydraulically controllable.

Abstract: A hydraulically controlled accumulator-chamber valve has a closing element and a tappet. The closing element is prestressed via a first compression spring and seals a valve seat in a valve body. The tappet reaches through a leadthrough in the valve body and is moved by an accumulator piston. The accumulator piston is loaded by a second compression spring. The tappet is moved to press the closing element out of the valve seat when there is a specified balance of forces between the spring prestressing forces and a hydraulically active force. The closing element and the tappet are configured as a single-piece component, in order to guide the tappet in the leadthrough in a longitudinally movable manner. The tappet bears against an end face of the accumulator piston during an opening movement.

Abstract: A vehicular lane departure prevention control apparatus calculates first and second departure amounts based on lane line position information and obstacle position information, sets braking forces for lane departure prevention control based thereon, and outputs the braking forces to a brake control unit, the braking forces for generating a yaw moment and a deceleration to a subject vehicle and preventing the vehicle from departing with respect to the lane line and obstacle, while setting a departure level for target pump motor rotation speed setting based on a vehicle speed, a difference of the steering wheel angle from a crossing angle and the first departure amount, setting a target rotation speed for a pump motor of a hydraulic unit in a brake control unit based thereon, and then outputting the target rotation speed to the brake control unit so as to variably control the rotation speed of the pump motor.

Abstract: An electronically controlled boosted brake system including an isolation valve between a source of pressurized fluid and a boost valve for selectively restricting the flow of fluid from the source to the boost valve. Another feature of the brake system relates to an accumulator valve connected between the boost valve and the accumulator for controlling when the operating pressure of the accumulator is supplied to the boost valve. Yet another feature is a unique master cylinder design including at least one primary piston positioned within a housing in an overlapping relationship with portions of a pair of secondary pistons.

Abstract: A system for use in a vehicle with a brake pedal and a brake circuit which includes a master cylinder assembly, a sensor assembly configured to generate a pedal position signal indicative of position of the brake pedal, an electronic control unit configured to (i) generate a brake request signal in response to generation of the pedal position signal, and (ii) generate a selector control signal, and a selector valve assembly operable in a first mode and a second mode, the selector valve assembly being moved from the first mode to the second mode in response to generation of the selector control signal, the master cylinder assembly is (i) isolated from fluid communication with the brake circuit when the selector valve assembly is positioned in the first mode, and (ii) in fluid communication with the brake circuit when the selector valve assembly is positioned in the second mode.

Abstract: A brake apparatus includes multiple wheel cylinders; multiple maintaining valves; a pressure-regulating control valve; and a control unit that controls the upstream pressure by switching a pressure-control mode between a pressure-regulating mode which is selected when a deviation of the upstream pressure from a target pressure is outside a setting range and in which the upstream pressure is brought to the target pressure using the pressure-regulating control valve and a pressure-maintaining mode that is selected when the deviation is within the setting range. The control unit opens the pressure-regulating control valve before the pressure-control mode is switched from the pressure-maintaining mode to the pressure-regulating mode.

Abstract: In a vehicle braking apparatus, a pressure control valve is controlled according to a brake operation amount of a brake pedal to thereby regulate hydraulic pressure and supply it to wheel cylinders. By controlling the pressure control valve by using hydraulic pressure output from a master cylinder as pilot pressure, the hydraulic pressure can be regulated and supplied to the wheel cylinders. A master cut valve capable of opening and closing a first hydraulic pipe that supplies the hydraulic pressure from the master cylinder to the wheel cylinders is provided. An external pressure supply pipe that supplies the pilot pressure to the pressure control valve is connected to the first hydraulic pipe on a side of the master cut valve closer to the wheel cylinders.

Abstract: A vehicle brake mechanism includes a master cylinder operated with a brake pedal. A first fluid channel connects a first hydraulic chamber of the master cylinder to a first-circuit wheel cylinder. A second fluid channel connects a second hydraulic chamber of the master cylinder to a second-circuit wheel cylinder. A master cut valve is provided in the first fluid channel and is capable of hindering communication between the first hydraulic chamber and the first-circuit wheel cylinder. A slave cylinder is connected to the second fluid channel and is driven by an actuator to generate a hydraulic pressure. A third fluid channel is provided downstream of the master cut valve and the slave cylinder and connects the first fluid channel and the second fluid channel to each other. A connection control valve is provided in the third fluid channel to close the third fluid channel.

Abstract: [OBJECT] To provide a brake control apparatus and method for controlling the brake which is capable of preventing a fluctuation of a brake pedal stroke amount when switching a regenerative braking force to a hydraulic braking force.

Abstract: A brake system with a master cylinder, a first piston which is coupled to a brake pedal via a push rod transmitting actuating forces, a second piston which can be actuated by the first piston and which can be brought into force-transmitting connection to a third piston, via which the master cylinder is actuated, at least one elastic element which forms a pedal travel simulator which, in the “brake-by-wire” operating mode, gives the vehicle driver a pleasant pedal sensation, an interspace capable of being acted upon with hydraulic pressure, between the second and the third piston, the action of pressure upon the interspace loading the second and the third piston in opposite directions, a pressure supply device which has a high-pressure source and which allows both a filling of the interspace with pressure medium and emptying thereof, and a valve device for varying pressure fed in the interspace.

Abstract: A method is provided that includes determining a state of a vehicle ignition switch; determining a state of the vehicle, wherein the vehicle state including at least one of whether the vehicle is in a torque producing mode, whether the vehicle is moving, and whether the vehicle brake system is engaged; and, controlling the vacuum pump in response to the vehicle state and the ignition switch state.

Abstract: Systems and methods to prevent dragging of a fluid pressure type disk brake system are described herein. Brake fluid pressure generated by a master cylinder during a braking operation is transmitted to a wheel cylinder via a VSA system. The VSA system includes a low pressure accumulator and an out-valve disposed between the wheel cylinder and the low pressure accumulator. Temporarily opening the out-valve during a braking operation allows part of the brake fluid that would otherwise be supplied to the wheel cylinder to be supplied to the low pressure accumulator. After the braking operation by the driver is completed, brake fluid supplied to the wheel cylinder is returned to the master cylinder. Thus, a piston of the wheel cylinder is withdrawn by an extra amount corresponding to the amount of brake fluid supplied to the low pressure accumulator, thus reliably prevents disk pad dragging in the disk brake system.

Abstract: An improved electro-hydraulic brake system having features for improving the pedal feel of the system, while further having design features which contribute to the economy of manufacture of certain components of the system. The system provides for an electrically powered normal source of pressurized hydraulic brake fluid, and a manually powered backup source of pressurized hydraulic brake fluid to the vehicle brakes in the event of failure of the normal source. During normal braking, fluid from the backup source is redirected from the vehicle brakes to a pedal simulator. The pedal simulator preferably includes arrangements of spring loaded pistons, expansion volumes, and damping orifices, together with valves selectively controlling the flow of fluid to and from the pedal simulator which provides for an improved pedal feel during vehicle braking.