Abstract: The invention relates to a method for controlling the activation of a brake of a hydraulic vehicle brake system of a hybrid vehicle which can be braked by the generator mode of an electric drive motor. The invention proposes equipping the vehicle brake system with an electromechanical brake booster and generating a pedal force at a brake pedal with the brake booster when braking by the generator mode of the electric drive motor occurs.

Abstract: A housing of a master cylinder device includes a housing member separating an interior of the housing into a front and a rear side chambers and having an opening through the housing member. A pressurizing piston includes a main body portion disposed in the front side chamber and is moved forward by a force for pressurizing the brake fluid. An input piston can move forward by an operation force. An input chamber into which a brake fluid from a high pressure source device is introduced is defined between a rear end of the main body portion of the pressurizing piston and the housing member. The input piston is fitted in the housing with seals, whereby, the input piston and the pressure receiving piston face to each other through the opening, though the input piston and the pressure receiving piston are not fitted to each other with any seal.

Abstract: A master cylinder device includes a housing whose front side end is closed and which includes a third housing member separating an interior of the housing into a front side chamber and a rear side chamber and having an opening through the third housing member, a first pressurizing piston which includes a main body portion disposed in the front side chamber and which is moved forward by receiving a force for pressurizing the brake fluid to be supplied to a brake devices, and an input piston. In the master cylinder device, an input chamber into which a brake fluid is introduced is defined between a rear end of the main body portion of the first pressurizing piston and the third housing member. The input piston is fitted in the housing with seals, whereby, an inter-piston chamber across which the input piston and the pressure receiving piston face to each other.

Abstract: A method in which a brake system for a motor vehicle is controlled and/or regulated. The motor vehicle having at least one electrically regenerative brake and a pressure-medium-operated, in particular a hydraulic brake system with friction brakes, wherein the wheel brakes assigned to the individual wheels are arranged in at least two brake circuits which can be charged with a pressure medium by a first brake pressure generator, in particular a tandem master brake cylinder, and wherein each brake circuit includes at least one pressure accumulator and at least two electronically activatable hydraulic valves. During a braking process with the one or more electrically regenerative brakes, by suitable activation of at least one hydraulic valve, at a point in time, the pressure medium is discharged only into precisely one predetermined pressure accumulator. The invention also relates to a corresponding brake system.

Abstract: Disclosed herein is a pedal simulator for an active brake system. The pedal simulator includes a simulator block provided therein with a bore, a first reaction unit including a first reaction piston slidably installed in the bore, a first damping member installed at the first reaction piston, and a first reaction spring compressed by the first reaction piston, and a second reaction unit including a second reaction piston provided in the bore to support the first reaction spring and slide in the bore, a damping housing connected to the simulator block to be spaced a certain distance apart from the second reaction piston, a second reaction spring installed between the second reaction piston and the damping housing to be compressed by the second reaction piston, and a second damping member installed in the damping housing to contact the second reaction piston. The second damping member is configured with an upper damper and a lower damper.

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 control device for a braking system of a vehicle, with the aid of which at least one provided setpoint variable regarding a setpoint brake pressure to be set in a first brake circuit and at least one provided actual variable regarding an actual brake pressure that is present in the first brake circuit, and/or an elasticity variable regarding an elasticity of a second brake circuit of the braking system are receivable, and a default variable regarding a setpoint additional volume of a brake fluid of the second brake circuit which is in a main cylinder braking mode is establishable, by taking into account a first deviation variable of the at least one actual variable from the at least one setpoint variable, and/or a second deviation variable of the elasticity variable from a predefined setpoint elasticity variable, so that a control signal corresponding to the established default variable is outputtable to at least one volume conveying device.

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: A method and a system controls braking of a vehicle. The method includes: detecting a pedal stroke, booster negative pressure, and master cylinder hydraulic pressure; setting target master cylinder hydraulic pressure on the basis of the detected pedal stroke and the detected booster negative pressure in a case in which a magnitude of the detected booster negative pressure is smaller than a magnitude of predetermined reference booster negative pressure; and compensating for the master cylinder hydraulic pressure in a case in which the detected master cylinder hydraulic pressure is smaller than the predetermined target master cylinder hydraulic pressure.

Abstract: A braking device for a vehicle is provided which includes a hydraulic booster to make wheels of the vehicle produce frictional braking force, a solenoid valve installed in a flow path connecting between a brake fluid accumulator and a servo chamber of the hydraulic booster, and a collision avoidance controller. When determining that there is a risk of a collision with an obstacle, the collision avoidance controller opens the first solenoid valve to achieve emergency braking to minimize the risk of the collision. Basically, the emergency braking is achieved only using the solenoid valve, thus allowing an emergency avoidance mechanism of the braking device to be constructed with a minimum of equipment and facilitating the mountability of the braking device in vehicles.

Abstract: Disclosed herein is a pedal simulator. The pedal simulator includes a main housing, a piston provided within the main housing so as to be reciprocally movable in upward and downward directions, an elastic support portion disposed within the main housing to provide elastic force in the upward direction against one piston, and a damper including a first deformation portion and a second deformation portion having a volume greater than the first deformation portion which are vertically disposed within the main housing, the damper being made of an elastic material such that the first and second deformation portions are sequentially compressed and deformed while being pressed by the piston according to downward movement of the piston.

Abstract: Provided is a driving device that applies a braking force to a first tire and a second tire rotatably arranged in a vehicle body. The driving device includes: a master cylinder configured to include a first liquid pressure chamber and a second liquid pressure chamber that supply a liquid pressure; a piston configured to apply an external force to the first liquid pressure chamber and the second liquid pressure chamber; a first hydraulic braking unit configured to apply a braking force to the first tire based on the liquid pressure supplied from the first liquid pressure chamber; and a second hydraulic braking unit configured to apply a braking force to the second tire based on the liquid pressure supplied from the second liquid pressure chamber.

Abstract: A vehicle brake system includes a brake pedal unit (BPU) coupled to a vehicle brake pedal and including an input piston connected to operate a pedal simulator during a normal braking mode, and coupled to actuate a pair of output pistons during a manual push through mode. The output pistons are operable to generate brake actuating pressure at first and second outputs of the BPU. A hydraulic pressure source for supplying fluid at a controlled boost pressure is included. The system further includes a hydraulic control unit (HCU) adapted to be hydraulically connected to the BPU and the hydraulic pressure source, the HCU including a slip control valve arrangement, and a switching base brake valve arrangement for switching the brake system between the normal braking mode wherein boost pressure from the pressure source is supplied to first and second vehicle brakes, and the manual push through mode wherein brake actuating pressure from the BPU is supplied to the first and second vehicle brakes.

Abstract: A vehicle brake system comprises a master brake cylinder having an input piston and master piston and connected to a wheel brake device, a reaction force generating device for generating a reaction force pressure corresponding to a displacement amount of the input piston, a change over valve provided in an open passage branched from a hydraulic conduit connecting the reaction force generating device to the reaction force chamber defined by the input piston and the change over valve connected to a reservoir, a brake force boosting device for applying an assisting pressure to a master piston, an assisting pressure limit judging portion for judging whether the assisting pressure has reached to an assisting limit pressure, and a change over controlling portion for changing over the change over valve to an open state when the assisting pressure limit judging portion judges that the assisting pressure has reached the assisting limit pressure.

Abstract: A brake device can prevent deterioration of braking force by applying a predetermined pressure in the drive hydraulic pressure chamber even when an electric system failure occurs. The brake device includes a stroke simulator portion, regulator, a first passage connecting the accumulator and the high pressure port of the regulator, a second passage connecting the reservoir tank and the low pressure port of the regulator, a third passage connecting the stroke simulator portion and the pilot pressure input port of the regulator, a fourth passage connecting the drive hydraulic pressure chamber and the output port of the regulator and a fifth passage connecting the accumulator and the drive hydraulic pressure chamber bypassing the high pressure port. The normally open type pressure decrease control valve is provided in the second passage or in the fourth passage whereas the normally closed pressure increase control valve is provided in the fifth passage.

Abstract: A brake system for motor vehicles, which in a “brake by wire” mode, can be activated both by the vehicle driver and also independently of the vehicle driver, which is operated preferentially in the “brake by wire” operating mode and can be operated in a fall-back mode. A pedal force actuating element connected to a brake pedal is guided in a retaining piston forming a retaining chamber. Dividing piston devices interact with the retaining piston and connected to vehicle wheel brakes. The first dividing piston and the second dividing piston surface are formed on a first dividing piston portion and the first dividing piston surface, together with a third dividing piston surface formed on a second dividing piston portion form an intermediate chamber connected to electrohydraulic pressure generating device. A pressure modulation valve enables both a build-up of pressure in and also a discharge of pressure from the intermediate chamber.

Abstract: Methods and systems are provided to reduce a hard brake pedal feel. A brake control variable is adjusted in anticipation of a hard pedal condition to increase hydraulic brake line pressure and maintain a normal pedal feel. A pedal force is inferred from brake line pressure relative to brake booster vacuum.

Abstract: A vehicle brake device includes a master cylinder having a master piston moved by servo pressure in a servo chamber and master pressure of a master chamber is changed by movement of the master piston. A mechanical servo pressure generating unit is connected to a high pressure source and the servo chamber, and generates a servo pressure within the servo chamber according to pilot pressure within a pilot chamber based on brake fluid pressure of the high pressure source. An electrical pilot pressure generating unit is connected to the pilot chamber and generates desired pilot pressure within the pilot chamber, and a master chamber-to-pilot chamber brake fluid line connects the master chamber with the pilot chamber so pilot pressure is generated by the pilot pressure generating unit during normal operation of a power supply system, and the master pressure is used as pilot pressure when the power supply system fails.

Abstract: A control device for a railway vehicle controls an inverter device based on a direct-current link voltage Vfc between the opposite terminals of a filter capacitor. A direct-current voltage applied to the inverter device during regeneration is the sum of a voltage Vb of power storage equipment and an overhead wire voltage Vs, so that only detecting the direct-current link voltage Vfc is not enough to separate the voltage Vb of the power storage equipment and the overhead wire voltage Vs from each other. The power storage equipment can be connected in series with the inverter device, and a voltage sensor that detects the overhead wire voltage Vs is provided between a current collector device and a grounding point. The power storage equipment is controlled based on the detection result from the voltage sensor.

Abstract: An electric brake actuator (motor cylinder apparatus) for generating hydraulic brake pressure on the basis of at least an electric signal corresponding to brake manipulation by an operator, which is incorporated in a vehicle brake system with an input apparatus being arranged separately from the electric brake actuator and receiving the brake manipulation. A reservoir reserving brake fluid is attached to a cylinder body included in the electric brake actuator, and the ceiling of the reservoir is inclined from the axis of the cylinder body in correspondence with an arrangement of the main body inclined from the horizontal line.

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: A controllable brake booster and a method and a device for controlling the brake booster are disclosed. The pedal force that a driver must apply in order to convey an input element of the brake booster into an actuating position or to retain the element in an actuating position is adjusted by operating the brake booster.

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: A brake system for a vehicle includes a main brake cylinder which has a first chamber which is hydraulically connected to at least one wheel brake cylinder for braking a wheel of the vehicle; an activating device for the driver to mechanically act on a piston of the main brake cylinder in order to pressurize hydraulic fluid in the first chamber of the main brake cylinder; and a pressure generating device which is hydraulically connected to the first chamber of the main brake cylinder, and which for activating the wheel brake cylinder supplies the wheel brake cylinder with hydraulic fluid through the first chamber of the main brake cylinder.

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 method for operating a hydraulic vehicle braking system that has an anti-lock control unit is disclosed. The system includes a brake master cylinder having an electromechanical brake booster. As the pressure level of the vehicle braking system decreases during an anti-lock control, in which all vehicle wheels are controlled, the boosting force of the brake booster is reduced in an anti-lock control of this type.

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 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: Disclosed is an electric disc brake capable of reducing noise and vibration while expanding the life span of the product. The electric disc brake includes a caliper housing to press friction pads provided at both sides of a disc against the disc, a cylinder installed in the caliper housing, a piston moving back and forth in the cylinder to press the friction pads, a driving device generating driving force with respect to the piston, and a volume compensation part communicated with the cylinder to compensate for an increment of a volume of the cylinder according to movement of the piston.

Abstract: A hydraulic brake system includes a braking state switching device which selectively realizes: a high-pressure-source-pressure dependent braking state in which a brake force is generated with a magnitude that depends on a pressure of brake fluid supplied from a high-pressure-source device; and an operation-force/high-pressure-source-pressure dependent braking state in which a brake force can be generated with a magnitude that depends on both of the pressure of the brake fluid supplied from the high-pressure-source device and a brake operation force of a driver which is applied to a brake operating member and that is larger than the magnitude of a brake force which can be generated in the high-pressure-source-pressure dependent braking state. The brake system may be equipped with a high-pressure-source device having a relatively small capacity, thereby allowing the high-pressure-source device to be compact and low-cost.

Abstract: A brake system for a vehicle includes brake cylinders operated by pressurized fluid for actuation of brakes by means of pressurized fluid on at least one first axle of the vehicle. The brakes on at least one other, second, axle can be actuated exclusively electromechanically in response to an electrical braking request signal. The pressure of the pressurized fluid can be modulated indirectly or directly and the electrical braking request signal can be generated indirectly or directly in response to actuation of a brake pedal of a brake pedal device. A service brake function is provided by means of hybrid use of the brakes on the first axle(s) together with the brakes on the second axle(s). The brake cylinders operated by pressurized fluid are pneumatically operated brake cylinders. The pressure modulated by the brake pedal device is a pneumatic pressure, and the pressurized fluid is compressed air.

Abstract: Disclosed is a method for operating a brake system for motor vehicles that can be actuated in a “brake-by-wire” operating mode both by the vehicle driver and independently of the vehicle driver, and that is operated preferably in the “brake-by-wire” operating mode, and that can be operated in a first fallback operating mode wherein a brake force amplifier is available, and in a second operating mode without brake force amplification, in which only operation by the vehicle driver is possible. According to the invention, the “brake-by-wire” operating mode, provided as the normal operating mode, is divided into energy-saving and high-power operating modes, between which a switch is made depending on the braking situation, and using different components of the hydraulic circuit.

Abstract: A vehicle brake system includes a brake pedal unit coupled to a vehicle brake pedal. The system includes an input piston connected to operate a pedal simulator during a normal braking mode, and coupled to actuate a pair of output pistons during a manual push through mode. The output pistons are operable to generate brake actuating pressure at first and second outputs of the brake pedal unit. A hydraulic pressure source supplies fluid at a controlled boost pressure. A hydraulic control unit is adapted to be hydraulically connected to the brake pedal unit and the hydraulic pressure source. The hydraulic control unit includes a slip control valve arrangement, and a switching base brake valve arrangement for switching the brake system between the normal braking mode wherein boost pressure from the pressure source is supplied to first and second vehicle brakes, and the manual push through mode wherein brake actuating pressure from the brake pedal unit is supplied to the first and second vehicle brakes.

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: To provide a vehicle provided with a valve-stop-mechanism-equipped internal combustion engine capable of ensuring a negative pressure in a brake booster while preventing with reliability fresh air from flowing into a catalyst during a valve stop control. An internal combustion engine provided with a valve stop mechanism capable of changing the operational state of an intake valve between a valve operating state and a valve closed/stopped state is provided. A brake booster is provided capable of assisting operation of a brake pedal of the vehicle. Exhaust side negative pressure passages are provided as communication passages that are configured to be in communication with each branch pipe section of an exhaust manifold in a period in which a negative pressure is generated in the case where the intake valve is in the valve closed/stopped state while an exhaust valve is allowed to open and close. The remaining end of the second exhaust side negative pressure passage is connected to the brake booster.

Abstract: Methods and systems are provided to reduce a hard brake pedal feel. A brake control variable is adjusted in anticipation of a hard pedal condition to increase hydraulic brake line pressure and maintain a normal pedal feel. A pedal force is inferred from brake line pressure relative to brake booster vacuum.

Abstract: A method for controlling the activation of a hydraulic vehicle brake system of a hybrid vehicle, which can be braked by generator operation of an electric drive motor, includes compensating for the braking effect of the electric drive motor and reducing a wheel brake pressure in the wheel brakes of the vehicle wheels by opening brake pressure-reducing valves, which are braked with the electric drive motor.

Abstract: A vehicle braking apparatus that can exert high braking performance during vehicle braking is implemented by a control mode that can be realized in a braking apparatus (10) of usual hardware. In controlling the braking apparatus (10) of a vehicle, a climb rate of a wheel cylinder braking oil pressure (Pw) is decreased smaller than a climb rate corresponding to a climb rate of a master cylinder oil pressure (Pm) from a time point at which the wheel cylinder braking oil pressure (Pw) reaches a predetermined threshold value. The time point at which the wheel cylinder braking oil pressure (Pw) reaches the predetermined threshold value (P3) is estimated based on the climb process of the master cylinder oil pressure (Pm) or directly detected.

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 hydraulic brake system is proposed which includes a hydraulic booster for boosting brake operation, and a circulation type pressure control unit. The hydraulic brake system further includes a hydraulic booster including an auxiliary hydraulic pressure source, a pressure regulator for adjusting the hydraulic pressure supplied therefrom to a value corresponding to an operating amount of a brake operating member and introducing the thus adjusted hydraulic pressure into a boost chamber, and a boost piston for actuating a master piston with a force boosted by an assisting force generated by the hydraulic pressure introduced into the boost chamber. The hydraulic booster further includes a hydraulic line bypassing the pressure regulator and extending from the boost chamber to the auxiliary hydraulic pressure, and a check valve provided in the hydraulic line and configured to allow only a discharge of hydraulic pressure from the boost chamber into the auxiliary hydraulic pressure source.

Abstract: A hydraulic brake apparatus includes a master cylinder pressurizing brake fluid in a pressure chamber and outputting a hydraulic pressure to a wheel cylinder of a first brake circuit, and a pressure control valve controlling a hydraulic pressure of an auxiliary hydraulic pressure source outputting the controlled hydraulic pressure to a wheel cylinder of a second brake circuit, wherein a master cylinder piston includes a first passage which hydraulically connects the pressure chamber and a reservoir, and a switching valve which closes and opens the first passage, and wherein a throttle means and a check valve, which allows the brake fluid to travel only from the reservoir to the pressure chamber, are hydraulically provided in parallel with each other at the first passage at a position between the switching valve and the reservoir.

Abstract: A brake apparatus includes: a master cylinder that forms a driving fluid pressure chamber, which drives master pistons as brake fluid is supplied and discharged; a pressure adjusting part adjusting a driving fluid pressure of the driving fluid pressure chamber; a reaction force generator that forms a reaction force chamber and that is configured to generate a reaction force fluid pressure in the reaction force chamber in accordance with an operating amount of the brake operation member; a brake fluid path, which connects the reaction force chamber to the driving fluid pressure chamber, and a valve device configured to block, at a current-on state, flowing of the brake fluid, and that communicates, at a current-off state, the reaction force chamber to the driving fluid pressure chamber through the brake fluid path to enable the flowing of the brake fluid.

Abstract: In a brake system, when setting a control origin position for a resolver for detecting a moved position of a booster piston, communication between a master cylinder and wheel cylinders is interrupted by cut valves. Thereafter, the booster piston is moved forward by an electric actuator in a direction in which a hydraulic pressure is generated so that a position detected by the resolver upon detection of generation of the hydraulic pressure by a hydraulic pressure sensor (position at a time of generation of hydraulic pressure) is obtained. A position obtained by moving backward the position at the time of generation of hydraulic pressure by a predetermined amount is set as the control origin position.

Abstract: An electrically actuated booster performs displacement control such that the relative displacement relationship between an input member and an assist member is variable according to the absolute displacement of the input member. A target displacement that makes variable the relative displacement relationship between an input piston and a booster piston is set according to a detection signal from a potentiometer (86), and displacement control is performed so that the relative displacement between the two pistons becomes equal to the target displacement on the basis of a signal from a relative displacement sensor (100) that detects the relative displacement between the two pistons.

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 operable to move a piston of the piston assembly for varying the volume of the second fluid chamber, and movement of the piston does not vary the volume of the first fluid chamber.

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: The invention relates to an electromechanical brake force booster for a hydraulic vehicle brake system. The invention proposes that the brake force booster be formed with two restoring springs, one of which acts on an electromechanical actuator and the other of which restoring springs acts on a pedal rod. In the event of failure of the electromechanical actuator, only the other spring, which preferably has a relatively low spring force, must be compressed using muscle force. The force loss in the event of actuation exclusively by muscle force is reduced.

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: The three-way valve simulator (100) for a vehicle brake servo comprises: a control piston (106); and a reaction piston (140) remote from the control piston when the simulator is at rest. It is arranged such that the control piston, under the effect of a command transmitted from outside the simulator, can be moved over a predetermined travel in the direction of the reaction piston without transmitting stress to the latter.

Abstract: A vehicle braking apparatus includes: a control piston configured to operate so that a reaction force based on the fluid pressure of the boosted fluid pressure application chamber is balanced with a braking operation input from the brake operation member; an elastic member including: a first face adapted to contact with a simulator piston connected to the brake operation member and slidably accommodated in the control piston; and a second face; a sliding member adapted to contact with the second face, the sliding member being accommodated in the control piston; a spring disposed between the sliding member and the control piston; and an odd-shaped portion disposed on at least one of the first and second faces of the elastic member, the odd-shaped portion configured to increase a contacting area of the elastic member and at least one of the simulator piston and the sliding member.