# US 2014/0197680 A1 · Hydraulic Vehicle Braking System with Electromechanical Actuator, and Method for Operating Such a Hydraulic Vehicle Braking System > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197680 A1 - Document ID: US20140197680A1 - Status: Published application - Kind: A1 - Application number: 14/116,349 - Filed: 2012-03-13 - Published: 2014-07-17 - Earliest claimed: 2011-05-10 - Assignees: Lucas Automotive GmbH - Inventors: Leo Gilles - Web page: https://patentgrep.com/patent/US20140197680A1 ## CPC - B60T 13/745: {acting on a hydraulic system, e.g. a master cylinder} - B60T 8/175: Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control (safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16) - B60T 8/1755: Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve (road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02) - B60T 8/176: Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS (B60T8/1755 takes precedence) - B60T 8/3275: {Systems with a braking assistant function, i.e. automatic full braking initiation in dependence of brake pedal velocity} - B60T 8/4077: {Systems in which the booster is used as an auxiliary pressure source} - B60T 8/42: having expanding chambers for controlling pressure {, i.e. closed systems} - B60T 8/4275: {Pump-back systems} - B60T 8/4845: {using a booster or a master cylinder for traction control} - B60T 8/4872: {pump-back systems} - B60T 13/143: {Master cylinder mechanically coupled with booster} - B60T 13/58: Combined or convertible systems - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES ## Abstract A hydraulic vehicle braking system comprises a master cylinder having at least one piston displacably accommodated therein, a mechanical actuator that is coupled, or can be coupled, to a brake pedal for actuating the piston, and an electromechanical actuator. The electromechanical actuator is likewise provided for actuating the piston and can be activated, at least for boosting or generating brake force, when the brake pedal is actuated. Furthermore, a valve arrangement is provided, which has a first valve per wheel brake for selectively uncoupling the wheel brake from the master cylinder, and a second valve for selectively reducing the brake pressure at the wheel brake. The valve arrangement can be controlled at least within the framework of an ABS control mode. ## Claims ### Claim 1 Hydraulic vehicle braking system (100; 400; 500), comprising: a master cylinder (136) having at least one piston (140) displaceably accommodated therein; a mechanical actuator (162), coupled or couplable to a brake pedal, for actuating the piston (140); an electromechanical actuator (158) for actuating the piston (140), the electromechanical actuator (158) being drivable at least for brake force boosting or brake force generation upon an actuation of the brake pedal; and a first valve arrangement (300), which per wheel brake (116) has a first valve (304) for selectively uncoupling the wheel brake (116) from the master cylinder (136) and a second valve (308) for selectively reducing the brake pressure at the wheel brake (116), the first valve arrangement (300) being drivable at least in the context of an ABS control mode. ### Claim 2 (depends on 1) Vehicle braking system according to claim 1, the electromechanical actuator (158) having a transmission (198) extending concentrically with respect to the mechanical actuator (162). ### Claim 3 (depends on 2) Vehicle braking system according to claim 2, the transmission (198) being configured as a nut/spindle arrangement (210; 214; 218). ### Claim 4 Vehicle braking system according to one of the preceding claims, the electromechanical actuator (158) having at least one electric motor (194) with a rotor (206) extending concentrically with respect to the mechanical actuator (162). ### Claim 5 (depends on 3, 4) Vehicle braking system according to claim 3 and claim 4, the rotor (206) driving the nut/spindle arrangement (210) or forming a component of the nut/spindle arrangement. ### Claim 6 Vehicle braking system according to one of the preceding claims, further comprising: a decoupling device (182) for selectively decoupling the brake pedal from the piston (140) of the master cylinder (136); and a simulation device (132) for providing a pedal reaction behaviour when the brake pedal is decoupled from the piston (140). ### Claim 7 Vehicle braking system according to one of the preceding claims, further comprising: at least one low-pressure accumulator (312), which is couplable to the wheel brake (116) via the second valve (308) assigned to each wheel brake (116), in order to receive hydraulic fluid discharged in the context of a brake pressure reduction. ### Claim 8 (depends on 7) Vehicle braking system according to claim 7, the at least one low-pressure accumulator (312) being coupled to an inlet side of the first valve (304) in order to release the received hydraulic fluid via a non-return valve (350). ### Claim 9 Vehicle braking system according to one of the preceding claims, further comprising: an electrically operated hydraulic pressure generator (316; 320) provided in addition to the master cylinder (136), the hydraulic pressure generator (316; 320) being drivable in a brake control mode which is different from the brake force boosting or brake force generation upon an actuation of the brake pedal. ### Claim 10 (depends on 7, 9) Vehicle braking system according to claims 7 and 9, the at least one low-pressure accumulator (312) being coupled to an inlet side of the hydraulic pressure generator (316; 320) in order to release the received hydraulic fluid. ### Claim 11 (depends on 9, 10) Vehicle braking system according to claim 9 or 10, the electromechanical actuator (158) being drivable exclusively for the purpose of the brake force boosting or brake force generation upon an actuation of the brake pedal. ### Claim 12 (depends on 9, 10) Vehicle braking system according to claim 9 or 10, the electromechanical actuator (158) being drivable in at least one brake control mode which is different from the ABS control mode; and the hydraulic pressure generator (316; 320) being drivable exclusively in the ABS control mode. ### Claim 13 (depends on 12) Vehicle braking system according to claim 12, the brake control mode which is different from the ABS control mode comprising at least one of the following operating modes: a traction control mode; and an electronic stability program, or ESP. ### Claim 14 (depends on 9, 10, 11, 12, 13) Vehicle braking system according to one of claims 9 to 13, further comprising: a second valve arrangement (324), which is configured for selectively uncoupling the master cylinder (136) from an outlet side of the hydraulic pressure generator (316; 320) in at least one of the following operating modes: a traction control mode; and an electronic stability program, or ESP. ### Claim 15 (depends on 1, 2, 3, 4, 5, 6, 7, 8) Vehicle braking system according to one of claims 1 to 8, the vehicle braking system having no electric motor-actuable hydraulic pressure generator provided in addition to the master cylinder (136). ### Claim 16 (depends on 15) Vehicle braking system according to claim 15, the electromechanical actuator (158) being drivable in the context of a brake control mode which is different from the brake pressure boosting or brake pressure generation upon an actuation of the brake pedal. ### Claim 17 (depends on 16) Vehicle braking system according to claim 16, the brake control mode comprising the ABS control mode. ### Claim 18 Vehicle braking system according to one of the preceding claims, further comprising: a third valve arrangement (268, 272), which is configured for at least one of the following purposes: for reducing hydraulic pressure in the event of failure of the electromechanical actuator (158); and for selectively coupling at least one chamber (144, 148) of the master cylinder (136), in which the piston (140) is accommodated, to an unpressurised hydraulic fluid reservoir. ### Claim 19 (depends on 18) Vehicle braking system according to claim 18, the third valve arrangement (268, 272) being configured to selectively couple, when the first valve (304) is open, the associated wheel brake (116) to an unpressurised hydraulic fluid reservoir for hydraulic pressure reduction. ### Claim 20 (depends on 18, 19) Vehicle braking system according to claim 18 or 19, the third valve arrangement (268, 279) being configured to couple, in the regenerative braking mode, the chamber (144, 148) of the master cylinder (136) to the unpressurised hydraulic fluid reservoir. ### Claim 21 Method for operating a hydraulic vehicle braking system (100; 400; 500) having a master cylinder (136) having at least one piston (140) displaceably accommodated therein, a mechanical actuator (162), coupled or couplable to a brake pedal, for actuating the piston (140), an electromechanical actuator (158) for actuating the piston, and a first valve arrangement (300), which per wheel brake (116) has a first valve (304) for selectively uncoupling the wheel brake (116) from the master cylinder (140) and a second valve (308) for selectively reducing the brake pressure at the wheel brake (116), the electromechanical actuator (158) being driven at least for brake force boosting or brake force generation upon an actuation of the brake pedal, and the first valve arrangement (300) being driven at least in the context of an ABS control mode.