Abstract: A hybrid control method controls a hybrid vehicle. A control unit sets a rotational speed threshold value at which a continuous gear tooth striking sound occurring in a gear mechanism connecting an electric power generation motor to the internal combustion engine is not a problem in terms of vehicle quality. The control unit generates negative pressure while maintaining the engine rotational speed in the firing state where the engine rotational speed is equal to or greater than the rotational speed threshold value. Also, the control unit generates negative pressure after switching from the firing state to a motoring state where the internal combustion engine is rotated by the electric power generation motor and where the engine rotational speed is less than the rotational speed threshold value.

Abstract: A motor vehicle having a bulkhead includes: a brake unit, a housing of which is fastenable to the bulkhead of the motor vehicle. An actuating member for actuation of the brake unit extends through the bulkhead. A radial flange is provided on a housing surface facing toward the bulkhead. On the bulkhead, there is provided at least one corresponding fastening element which at least partially engages around the radial flange.

Abstract: A braking system for automatic driver-independent deceleration of a vehicle includes a hydraulic vehicle brake and a backup braking system. The hydraulic vehicle brake includes an adjustable brake pressure control device. A method for automatic driver-independent deceleration of a vehicle includes decelerating the vehicle by actuating a braking pressure control device and, in response to a set point valve set in a hydraulic vehicle brake exceeding a threshold value, actuating a backup braking system.

Abstract: An electromechanical brake booster for a braking system of a vehicle. The brake booster includes a spindle nut that is movable into rotation using an electric motor that is intrinsic or external to the brake booster, a spindle situated at the spindle nut and rotatably fixedly held using a support plate in such a way that the spindle and the support plate are movable into pure translatory motion using the spindle nut that is moved into rotation, and a reaction disk receiving element that is also movable using the support plate that is moved into pure translatory motion. The reaction disk receiving element includes a receiving opening in which a reaction disk is situated. The support plate and the reaction disk receiving element are designed as a one-piece component. A method for manufacturing an electromechanical brake booster for a braking system of a vehicle, is also described.

Abstract: An electrically actuatable operating unit (106) for a motor vehicle brake comprises a housing body (122) which is arranged so as to be displaceable in a braking direction for operation of the motor vehicle brake, a recess (150) formed in the housing body (122), wherein the recess (150) is delimited at one longitudinal end by a contact shoulder (172), a through-opening (158) delimited by the contact shoulder (172), an operating member (124) which is arranged in the recess (150) so as to be displaceable for operation of the motor vehicle brake and projects through the through-opening (158) of the contact shoulder (172), wherein the operating member (124) can be arranged in a force-transmitting manner between a brake pedal and the motor vehicle brake (400).

Abstract: A method for controlling a hydraulic control system that includes a variable pressure relief valve and may include steps for calibrating the hydraulic control system. The hydraulic control system may be calibrated by: controlling, with the controller, the variable pressure relief valve to move to a fully open position, increasing, with the pump, a fluid pressure upstream of the variable pressure relief valve, controlling, with the controller, the variable pressure relief valve to move from the fully open position toward a fully closed position by adjusting a control signal supplied to the variable pressure relief valve, monitoring, with the controller, the pressure detected by the pressure sensor, and recording, with the controller, a parameter of the control signal supplied to the variable pressure relief valve when the pressure detected by the pressure sensor reaches a target pressure.

Abstract: A brake booster for a brake system of a vehicle, having a first input piston component, and a valve body. The brake booster has a second input piston component, which is pushed away from the first input piston component in the braking direction using a compression spring, and a locking mechanism is embodied such that when the differential travel between the booster travel and the input travel is smaller than a predefined first limit value, the second input piston component is adjustable using the compression spring together with the valve body away from the first input piston component, and when the differential travel exceeds the first limit differential travel, the second input piston component is locked in place on the first input piston component.

Abstract: A method for actuating a solenoid valve, which is loaded with a pneumatic pressure medium, in order to reduce a pressure (psys) which is applied to the solenoid valve, where the solenoid valve assumes a closed switching position in the deenergized state and assumes a completely open switching position when it is energized with a switching current intensity (Is(p)) which is dependent on the applied pressure (psys), where a first rise current final value (I1) is predetermined, which first rise current final value is smaller than the switching current intensity (Is(p)), where the solenoid valve is energized with an actuating current which follows an actuating current profile (SV1, SV2), and where the actuating current profile (SV1, SV2) comprises a first rise phase (TA1), in which the actuating current is increased to the predetermined first rise current final value (I1), and, following said first rise phase, a first holding phase (TH1) in which the actuating current is held constant at the first rise current fi

Abstract: A method and a system for verifying normal operation of a negative pressure sensor of a brake booster is provided. The method and system verify whether the negative pressure sensor of the brake booster is in normal operation and the normal operation of the booster negative pressure sensor is detected by mutually verifying values measured by the booster negative pressure sensor and values measured by sensors that indirectly sense the booster negative pressure.

Abstract: An electric vacuum pump applied to a vacuum boosting brake system is provided. The pump has a water containing capacity that is greater than a backflow water capacity of an internal space defined in a pump housing which forms vacuum pressure. The pump includes a watertight chamber that is coupled to an exhaust port of a pump housing.

Abstract: A vehicle brake mechanism that includes a pedal, a piston attached to the pedal, a spring associated with the piston and exerting a longitudinal force on the piston in a direction opposite the braking direction in order to bring the pedal to a resting position, and an autonomous brake module. A manual braking force on the pedal causes a longitudinal movement of the piston and displaces a transmitter element integrally joined to the piston. The autonomous brake module causes a movement of an intermediate plate that displaces the transmitter element and the piston, exerting a longitudinal force on the piston in the braking direction. The brake mechanism determines the force in the direction opposite the braking direction using a sensor situated on or in the intermediate plate and/or the transmitter element.

Abstract: A control device for a controllable brake booster of a braking system is configured to: establish a setpoint variable regarding a setpoint operation to be carried out with the aid of the controllable brake booster, under consideration of a provided specified variable regarding a setpoint pressure to be set in a partial volume of the braking system; establish a setpoint difference of the setpoint variable, under consideration of the specified variable and an actual variable regarding an actual pressure present in a subarea of the braking system, to establish a corrected setpoint variable taking the established setpoint difference into consideration; and output a control signal which corresponds to the established corrected setpoint variable to the controllable brake booster and/or to the power supply component of the controllable brake booster.

Abstract: A brake control apparatus includes: a master cylinder that outputs a brake fluid at a master pressure; a master pressure changing device that can change the master pressure irrespective of an operation of a brake pedal; a brake actuator; and a control unit that executes antilock control by reducing a brake pressure of a target wheel. Modes of the antilock control include a normal mode and a pseudo mode. In the pseudo mode, the control unit operates the master pressure changing device such that the master pressure obtains a target value of the brake pressure of the target wheel, and changes the brake pressure of the target wheel in an interlocking manner with the master pressure. When the normal mode is unavailable, the control unit executes the antilock control in the pseudo mode.

Abstract: A vacuum system for the brake booster of a motor vehicle includes a demand-driven vacuum pump and a vacuum line connected on one end to the vacuum chamber of the brake booster and connected on another end to an intake port of the demand-driven vacuum pump. The vacuum system may include a discharge device arranged on an exhaust air opening of the vacuum system for ensuring bidirectional air volume flow between the external surroundings of the discharge device and the exhaust air opening of the vacuum system, which preventing liquids from reaching the exhaust air opening of the vacuum system as an air volume flows from the exterior surroundings into the exhaust air opening of the vacuum system. The vacuum system may also include a check valve arranged between the intake port of the demand-driven vacuum pump and the connection to a vacuum chamber of the brake booster.

Abstract: Methods and systems are provided for a pressure tapping device for a motor vehicle where a portion of the pressure energy generated at the fuel storage reservoir is transmitted to a working medium, physically separate from the fuel via the pressure tapping device. The pressure tapping device is fluidically coupled to a pressure actuator and enables the pressure operation via transmission of the pressure energy and adjustment of valves diverting flow from the fuel storage reservoir to the engine intake through the pressure tapping device.

Abstract: A method for operating a brake system for motor vehicles comprises in a normal control mode of the system, a displacement of a piston for a pressure supply device is terminated, and inlet valves of the wheel brakes are closed in the event of a specified brake condition. The normal control mode is switched to a special control mode in the event of a specified condition for the pressure supply device. In the event of the specified brake condition in the special control mode, a displacement of the piston of the pressure supply device is terminated by outputting an actuation signal to the pressure supply device, and for at least one selected wheel brake, the corresponding inlet valve is kept open and the corresponding outlet valve is opened at least temporarily while the inlet valves of the remaining wheel brakes are closed.

Abstract: A brake boost assist system for use with a master cylinder of a motor vehicle braking system, includes an inductive sensing system. The inductive sensing system has sensing devices carried on an input member and an output member, where the input and output members are coupled to respective ones of an input rod and an output rod of the brake boost assist system. Movement of the input and output members relative to one another, and relative to a fixed element of the inductive sensing system positioned within the brake boost assist system, enables an accurate estimation of the distance of a pedal gap which separates faces of the input and output rods. The accurate estimation of the pedal gap distance enables a more accurate determination to be made of the braking force required for any given pedal stroke input by an operator of the vehicle during a braking action.

Abstract: A method, system, and apparatus to determine a malfunction or an abnormal pressure condition in a hydraulic system over a time period are provided. The method, system, and apparatus include monitoring hydraulic accumulator charge time, hydraulic accumulator discharge time, and hydraulic pump pressure over the time period, and determining whether the monitored hydraulic accumulator charge time, hydraulic accumulator discharge time, and hydraulic pump pressure are within respective predetermined ranges. A maintenance notification is output responsive to at least one of the monitored hydraulic accumulator charge time, hydraulic accumulator discharge time, and hydraulic pump pressure being outside the respective predetermined ranges during the time period.

Abstract: A vehicle braking system includes a service brake pedal and a sensing device configured to monitor a position of the service brake pedal. A processing device is configured to control an amount of braking force provided by the vehicle braking system as a function of the position of the service brake pedal. The braking system further includes a return spring operatively coupled to the service brake pedal and configured to provide a substantially linear pedal effort feedback during an initial range of motion of the service brake pedal. Additionally, a damping device that operates in compression as the service brake pedal is depressed is configured to provide a substantially non-linear pedal effort feedback during a subsequent range of motion of the service brake pedal.

Abstract: An electric brake system is disclosed. The electric brake system includes a master cylinder configured to discharge oil according to a pedal effort of a brake pedal, a simulation device provided with a simulator valve provided at a flow path connecting a simulation chamber, which is connected to the master cylinder to accommodate oil therein, to a first reservoir for storing oil therein so as to provide a reaction force according to the pedal effort of the brake pedal, and an inspection valve provided at a flow path connecting the first reservoir to the master cylinder or at a flow path connecting the master cylinder to the simulation device.

Abstract: An apparatus and method for protecting an intact portion of a service brake system from a failed wheel end of a vehicle is provided. A failure in a wheel end is detected by determining an operation state of each of the wheel ends by monitoring parameters including the pressure in a parking brake air supply line. When it is determined that a failed wheel end is present in the service brake system, a service brake isolation valve is switched to a state in which the failed wheel end is isolated from the rest of the brake system. The service brake of the failed wheel end is disabled, while the service brakes of the other wheel ends are enabled for normal operation. The parking brake of the failed wheel end is enabled, while the parking brakes of the other wheel ends are disabled to prevent immobilization of the vehicle.

Abstract: A method is described for operating a hydraulic braking device of a vehicle, in particular a motor vehicle, including at least one brake booster, which sets a brake boost as a function of a driver's braking command. It is provided that the driver's braking command is ascertained via a vacuum sensor assigned to a pneumatic brake booster and a hydraulic brake boost is set.

Abstract: Methods and systems are provided for a throttle plate and a vacuum consumption device. In one example, a method may include providing vacuum to a vacuum consumption device with a venturi passage inside a throttle.

Abstract: A negative pressure abnormality detection apparatus includes a negative pressure sensor to output a signal representing negative pressure in a negative pressure chamber of a brake booster into which intake negative pressure of an intake manifold generated by rotation of an engine is introduced; a negative pressure detection unit to detect the negative pressure based on the signal; an abnormality determination unit to determine whether an abnormality occurs with the negative pressure sensor, based on whether the negative pressure is shifted toward atmospheric or vacuum pressure relative to a threshold, when a state continues for a predetermined time or longer during which the engine rotates and a negative-pressure-expending braking operation is not performed; and a threshold change unit to change the threshold depending on opening of a throttle valve in an intake pipe connected with the intake manifold, while the state continues.

Abstract: A load drive controlling device includes a dulling controller, a dulling adjuster, and a Proportional Integral (PI) controller. The dulling adjuster sets a first electric current value for a dulling adjustment operation according to a change trend of a target electric current value in an inductive load. The dulling adjuster performs the dulling adjustment operation on the first electric current and limits a dulled value based on a guard value. The PI controller performs a PI control based on a deviation between the dulled value and an actual value of the electric current. The dulling controller sets the first electric current value and the guard value according to a change trend of the target electric current value. In such a configuration, the load drive controlling device improves an electric current response while preventing an over-accumulation of an integration value.

Abstract: A vacuum enhancer having four apertures, one of which is open to the atmosphere, wherein a piston selectively restricts fluid flow through an ejector based on a pressure differential between a vacuum chamber within the vacuum booster and true atmospheric pressure.

Abstract: A portion of a fuel system of a vehicle is disclosed. The vehicle includes a brake system. The fuel system includes a fuel tank connected to an engine. The portion of the fuel system includes an evaporative emissions system and an evaporative emissions leak check system selectively fluidly-connected to the evaporative emissions system. The evaporative emissions leak check system includes a vacuum source. The vacuum source includes a vacuum pump connected to a brake boost device that provides power braking to the brake system of the vehicle. A method is also disclosed.

Abstract: An electric vacuum pump backup control system includes a brake on/off switch, a primary electric vacuum pump control interfacing with the brake on/off switch, a secondary electric vacuum pump control interfacing with the brake on/off switch and the primary electric vacuum pump control and an electric vacuum pump interfacing with the primary electric vacuum pump control.

Abstract: A hybrid or electric vehicle includes a hydraulic brake system having an active vacuum booster with an active boost control valve actuated by at least one controller. An isolation valve is disposed in a fluid circuit that fluidly connects a master cylinder to hydraulic brakes. A brake pedal is capable of moving in an initial deadband displacement range when initially depressed by an operator of the vehicle. While in the initial deadband displacement range, the controller selectively activates the isolation valve to inhibit fluid flow from at least a portion of the fluid circuit to the master cylinder based at least upon an operating state of the active boost control valve.

Abstract: A brake actuating unit for actuating a motor vehicle braking system of the “brake-by-wire” type having a brake booster. In order to provide a brake actuating unit for actuating a motor vehicle braking system of the “brake-by-wire” type, which on the one hand fulfills the statutory requirements care and which on the other hand is inexpensive to produce, it is proposed according to aspects of the invention, that the brake booster be provided as a travel-controlled brake booster, so that when not in the “brake-by-wire” operating mode the brake pedal is decoupled from feedback forces of the brake actuating unit, and the return force is simulated by the pedal travel simulator even when not in the “brake-by-wire” operating mode.

Abstract: A vehicle brake system and method for operating same, having a master brake cylinder, a brake medium reservoir, and a first brake circuit, connected via a reservoir line to the brake reservoir, having at least one first wheel brake cylinder, a first wheel inlet valve associated with the first brake cylinder, a first pump, by which a first brake medium volume is pumpable from the reservoir line through the open first wheel inlet valve into the first brake cylinder, a continuously adjustable first wheel outlet valve, by which a first brake medium displacement from the first cylinder into the brake reservoir is controllable, and a connecting line having a spring-loaded non-return valve, via which a delivery side of the first pump is connected to the brake reservoir, a brake medium displacement from the brake reservoir to the delivery side of the first pump being prevented by the spring-loaded non-return valve.

Abstract: A brake system for a vehicle having a VIS actuator of an intake manifold, a vacuum pipe connected to the VIS actuator, and a vacuum pump connected to the vacuum pipe may be provided, which includes a vacuum hose having one end connected to the vacuum pipe to generate additional negative pressure, wherein the vacuum hose may be connected to a vacuum chamber. The brake negative pressure may be supplemented without increasing the capacity of the vacuum pump to improve the braking performance.

Abstract: The present invention relates mainly to a brake booster that is adjustable, notably in terms of the value of the jump. Advantageously, according to the invention, the target value for equilibrium of operation of the booster actuator is altered. A target value of a signal delivered by a position sensor is defined either by programming the electronic control unit or by selecting a coefficient in a program as a function of the braking characteristic or characteristics that it is desired to implement. Once the setpoint value has been determined, the electronic control unit commands the actuator using a setpoint value so that the actuator permanently and dynamically works toward achieving the previously defined and/or selected target value. The setpoint may be calculated as a function of torque, force, position or some other parameter.

Abstract: A brake force generator for a motor vehicle brake system, comprises a displaceable force input element connected or connectable to a brake pedal, a control valve actuable in accordance with a displacement of the force input element, a chamber arrangement disposed in a booster housing and controllable by the control valve and comprises at least one vacuum chamber and at least one working chamber, which are separated from one another by at least one movable wall connected to the control valve, and a force output element for supplying a brake force to a downstream brake system, wherein the control valve with the force output element is biased by a resetting spring into a normal position, wherein the resetting spring is supported by its one end against the control valve.

Abstract: Systems and methods for detecting unintended acceleration of a vehicle. One system includes a first sensor that provides information on a brake booster vacuum. The vacuum is provided by the vehicle's engine and the brake booster multiplies a braking force initiated by a driver. A second sensor provides information on the vehicle's speed, and a third sensor provides information on the braking force initiated by the driver. The system also includes a controller configured to receive the information from the first sensor, second sensor, and third sensor and initiate corrective action if the brake booster vacuum is less than a predetermined threshold, the vehicle's speed is greater than a predetermined threshold, and the braking force initiated by the driver is greater than a predetermined threshold.

Abstract: The invention relates to a method for operating a brake boosted brake system of a vehicle, comprising the monitoring of a mode of operation of the brake boosted brake system with regard to agreement of a total braking torque applied to at least one wheel of the vehicle by the brake boosted brake system with a specified target total braking torque and/or with regard to a displacement of a brake medium volume of the brake boosted brake system to a force/pressure conversion element (22) of the brake boosted brake system, if a braking torque difference between the applied total braking torque and the specified target total braking torque is greater than a specified reference difference, and/or if the brake medium volume displaced to the force/pressure conversion element (22) is larger than a specified reference volume; further comprising the defining of a target boosting force change with regard to a boosting force (Fu) provided by a brake booster (14) of the brake boosted brake system, taking into account the br

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 system for evacuating gas from a brake booster of a motor vehicle includes: a first conduit adapted to be connected fluidly to the brake booster; an electric pump connected fluidly to the first conduit, and controllable to evacuate gas from the brake booster via the first conduit; a second conduit; an electric valve fluidly connecting the first and second conduits to each other; a mechanical pump connected fluidly to the second conduit, and adapted to be driven by a vehicle drive unit of the motor vehicle to evacuate gas from the brake booster via the first conduit, the electric valve, and the second conduit; and a control unit operatively associated with the electric pump and the electric valve, and configured to control operations of the electric pump and the electric valve according to a working state of the mechanical pump.

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: A device includes: actual-intake-pipe-pressure detection unit (11); estimated-intake-pipe-pressure detection unit (12) for calculating an estimated intake pipe pressure based on a rotation speed of the engine and an opening degree of a throttle valve; pressure difference calculation unit (13) for calculating a pressure difference between the actual and estimated intake pipe pressures; pressure difference integration unit (14) for integrating the pressure difference with respect to time; pumping brake detection unit (15) for determining that a pumping brake operation is performed when a integral value is equal to or more than a first determination value; and throttle valve control unit (16) for carrying out control for the pumping brake during the pumping brake operation based on a result of the determination by the pumping brake detection unit (15), and carrying out ordinary control otherwise.

Abstract: An assistance-limit recognizing device for recognizing a limit of assistance made by a vacuum booster that is configured to assist an operating force applied to a brake operating member. A communication between a variable pressure chamber and a negative pressure chamber of the vacuum booster is established, when the operating force is not applied to the brake operating member. A communication between the variable pressure chamber and the atmosphere is established while the communication between the variable pressure chamber and the negative pressure chamber is cut off, when the operating force is applied to the brake operating member, whereby the operating force applied to the brake operating member is assisted based on a pressure difference between a pressure in the negative pressure chamber and a pressure in the variable pressure chamber.

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: The present invention relates to a brake booster device for a vehicle brake system comprising a force input element, a control valve arrangement actuable via the force input element, a chamber arrangement disposed in a housing and comprising a vacuum chamber and a working chamber, which is separated from the vacuum chamber by a movable wall and connectable selectively to a vacuum source or the atmosphere, and a force output element, wherein the movable wall is biased into a normal position by a resetting spring accommodated at least partially in the housing and wherein the housing is penetrated by at least one fastening bolt. In this case, it is provided that at least one damping element acts for the purpose of vibration damping on the resetting spring, wherein the at least one damping element is mounted on the at least one fastening bolt.

Abstract: A control apparatus for a negative pressure generating apparatus that includes an ejector that generates a negative pressure whose magnitude is larger than that of a negative pressure to be taken from an intake passage in an intake system for an internal combustion engine provided in a vehicle; and state change means for making the ejector function or stop functioning. The control apparatus includes prohibition control means for prohibiting the state change means from making the ejector function, according to a temperature of intake air.

Abstract: The invention relates to a braking control system for automotive vehicles comprising a braking control member (1), a brake booster (4) and a brake master cylinder (5). The system of the invention further comprises a simulator (3) coupled pneumatically to the piston (42) of the brake booster (4). Said simulator (3) receives at least one braking command from the braking control member (1) and makes it possible to establish, in return, a difference in pressure between the front chamber (40) and the rear chamber (41) of the brake booster so as to control the displacement of the piston (42). Application: Brakes for automotive vehicles.

Abstract: The invention relates to a brake control system for motor vehicles and, in particular, to a hydraulic control system. The invention also applies to hybrid braking systems such as those provided in hybrid vehicles (vehicles propelled electrically and propelled using internal combustion engines) comprising a hydraulically operating braking system which comprises a simulator (3) not mechanically coupled to the brake booster piston (42) and an electric braking system using the electric propulsion motor or motors as electric generators.

Abstract: A method of operating a drivetrain of a motor vehicle. The drivetrain comprises a drive aggregate formed as a hybrid drive with a combustion engine and an electric machine, and a transmission connected between the drive aggregate and a drive output. The drivetrain also comprises a pressure reservoir system with at least one pressure reservoir and at least one pressure generator by the combustion engine in order to fill the pressure reservoir. A pressure in the pressure reservoir of the pressure reservoir system is measured and a value of the actual pressure, in the pressure reservoir system, is compared with at least one threshold value. When the actual pressure value is higher than a threshold value, stopping of the combustion engine is permitted, whereas if the actual pressure value is lower than the threshold value, stopping of the combustion engine is not permitted.

Abstract: A method for creating low pressure in a brake activation device of a motor vehicle brake system, comprising a pneumatic brake force booster the interior of which is divided into at least one low-pressure chamber and one working chamber, a brake master cylinder and a pneumatic motor pump unit for creating the low pressure in the low-pressure chamber, which motor pump unit comprises a low-pressure pump and a motor driving the low-pressure pump, a low-pressure level in the low-pressure chamber or a pressure difference between the low-pressure chamber and the working chamber being detected by a sensor and the motor pump unit being activated by an electronic control unit if the pressure falls below a first predefined, lower low-pressure level Pe in the low-pressure chamber and being deactivated if a second predetermined, upper low-pressure level Pa is reached.

Abstract: A brake system of the brake-by-wire (BBW) type for a vehicle having a brake pressure signal generator which can be activated by a brake pedal and can be connected to wheel brakes outside the BBW operating mode, having a pressure source which can be actuated by an electronic control unit and can be connected to the brakes of the vehicle in the BBW operating mode, having provisions for sensing a driver's deceleration request and having a pedal travel simulator which interacts with the brake pedal. A restoring force acting on the brake pedal can be simulated in the BBW operating mode independently of the actuating of the pressure source, and having a device which can be actuated by the electronic control unit and which permits activation of the pedal travel simulator in the BBW operating mode and deactivation of the pedal travel simulator outside the BBW operating mode.

Abstract: According to a method for operating an actuating unit for motor vehicle brakes, an electromagnet that actuates a sealing seat of its control valve is controlled by a minimum current during a pressure-maintaining phase which is carried out independently of the vehicle operator's will, in order to avoid damaging of the coil of the electromagnet. To this end, a current controlling the electromagnet is slowly reduced until a previously fixed pressure decrease compared to the original value occurs. A previously fixed value is added to this current value, and the electromagnet is actuated by a current value corresponding to the result of the addition.