Robert Boschgmbh

Bastien Cagnac

Philippe Richard

Chris Anderson

Raynald Sprocq

Antony Auguste

Francois Gaffe

Laurent Lhuillier

François Gaffe

Matthias Kistner

Roman Winkler

Jean-Marc Ritt

Jean Fourcade

Carole Charpentier

Remy Garnier

Jean-Michel L'Aot

Vincent Maury

Masaki Shiwa

Alain Benoit

Laurent Vagner

Komi Sokou

Richard Philippe

Franøois Gaffe

Christian Schalkwijk

Takeshi Kaneko

Tim Albert

Florent Zorino

Hervé Angleviel

A brake control unit includes a primary piston and a secondary piston that respectively define a primary chamber and a secondary chamber. The primary piston carries an intermediate piston that slides in the secondary piston. A primary insulating seal is disposed between the pistons such that the primary insulating section of the primary insulating seal only depends on the equivalent section connecting the force applied at the inlet and the secondary pressure. The ratio of the hydraulic sections is configured to be modified without having to intervene on the primary and secondary pressure seals for the main piston and the secondary seal by way of modifying the section of the plunger piston and that of the seal thereof.

Brake control unit

A master brake cylinder for a braking system of a vehicle is described, having a first pressure chamber. A first rod piston element is movable into at least a first partial pressure chamber of the first pressure chamber in such a way that a first partial residual volume of the first partial pressure chamber which is fillable with liquid is reducible by moving the first rod piston element. The master brake cylinder also includes a second partial pressure chamber of the first pressure chamber which is delimited from the first partial pressure chamber via at least one partial partition and into which a second rod piston element is movable in such a way that a second partial residual volume of the second partial pressure chamber which is fillable with liquid is reducible by moving the second rod piston element. Moreover, a manufacturing method is described for a master brake cylinder.

Master brake cylinder for a braking system of a vehicle, and manufacturing method for a master brake cylinder

An electrohydraulic servo brake includes a master brake cylinder, which is controlled by a push rod. The push rod is configured to be actuated by a first auxiliary piston via a reaction disk. A plunger piston presses on the reaction disk. An end of the push rod is connected to the first auxiliary piston by a connection apparatus. The connection apparatus includes a rest for a rated compression spring, which rest is rigidly connected to the push rod, and a central piston, which rests against the reaction disk along an axis and is surrounded by a second auxiliary piston, which is placed against the reaction disk and is moved by the spring and is held in an end position by the central piston. The second auxiliary piston is configured to recede in relation to the central piston rigidly connected to the push rod.

Electrohydraulic servo brake

A brake system includes a master cylinder, an electric servo brake, and an electric motor. The electric motor drives a screw that engages a pair of helical gears which are each mounted on a respective shaft. Each shaft further mounts a gear that meshes with a respective gear rack. The electric servo brake includes a body that defines rails which guide the gear racks. A lever is supported on each end by one of the gear racks, and is connected to a support via a pivot point. The support lies flat against a side of a reaction disk that lies against a push rod that actuates the master cylinder.

Brake system having an electric servo brake

A master brake cylinder for a braking system of a vehicle has: a first filling volume, which is fillable with liquid, and whose first dimension is variable by adjusting at least one first piston wall; a second filling volume, which is fillable with liquid, and whose dimension is variable by adjusting at least one second piston wall; and a valve unit, the first filling volume being connected via the valve unit to the second filling volume in such a way that when the valve unit is switched into a first valve state, a joint first pressure chamber pressure prevails in the first filling volume and in the second filling volume.

Master brake cylinder for a braking system of a vehicle and method for operating a master brake cylinder

A brake-assist device for a motor vehicle having a servomotor is described. A servomotor has a plunger piston, a moving part, and an arrangement to move the moving part into position with respect to the plunger piston. The servomotor is actuated by a control rod. The control rod has a first end that presses upon the plunger piston and a second end to receive a force exerted by a brake pedal intended to be moved by a driver of the vehicle. The servomotor includes a sensor interposed in a contact space between the plunger piston and the moving part. A spring is compressed between the plunger piston and the moving part. The servomotor includes an arrangement for displacing the plunger piston in the contact space based on the driving mode. A stiffness of the spring is sufficiently high for an onset of braking to occur only with a striking force that is significantly higher during a reactive driving mode than it is during a calm driving mode.

Brake assist device and motor vehicle comprising such a device

A primary piston component for a master cylinder of a hydraulic brake system includes a primary piston housing and an additional piston component, which is configured to be at least partially movable into a cavity of the primary piston housing. An inner piston body extends through the cavity along a central line of the primary piston component. A braking force applied on a brake actuating element is transferable at least partially on the inner piston body, and further on the primary piston housing. The additional piston component is at least partially movable into the cavity between the inner piston body and the primary piston housing, and a brake booster force is transferable at least partially on the additional piston component, and via the inner piston body on the primary piston housing. A method of operating a hydraulic brake system is also described.

Primary piston component for a master cylinder of a hydraulic brake system and method of operating a hydraulic brake system

An electric brake booster includes an electric motor activating a booster piston acting on the master-cylinder during brake pedal activation. The booster piston is driven in the direction of the action of same on the master-cylinder by an electric motor linked to a mechanical transmission that includes a screw held by the motor shaft. The screw meshes with two symmetrical worm gears that are integral with respective transmission shafts housed in a bearing of the body of the brake booster. The two shafts each carry a spur gear that meshes with a rack of the booster piston. The shafts are free in translation relative to the screw and to the body of the electric brake booster but are integral with each other in the translational movement of same. The shafts are integrally connected in translation by a coupling member formed by a crosspiece carrying two rotation bearings.

Electric brake booster with transmission clearance compensation

The system includes a high-pressure accumulator connected to the primary chamber of the master cylinder and to the inlet of the ESP module by a solenoid valve. The connection between the primary chamber and the brake fluid reservoir is equipped with a solenoid valve. A control circuit controls the solenoid valve of the reservoir and the solenoid valve of the accumulator, depending on the braking method selected or imposed. The dynamic braking phase is broken down into two tasks, one with energy recovery that involves isolating the master cylinder from the wheel brakes until deceleration to a threshold speed, followed by another step until full stop that involves connecting the primary chamber alone to the high-pressure accumulator and to the ESP module to provide the latter with pressurized brake fluid from the accumulator and supply the wheel brakes for mechanical braking.

Electro-hydraulic dynamic braking system and control method

A brake system is described with a master cylinder actuated by a control rod connected to a plunger piston and an actuator piston acting directly on the primary piston. A hydraulic reaction piston is housed in the piston so it can be subjected to the pressure of the primary chamber and to the opposing action of a reaction spring. The plunger piston can push the reaction piston directly to push the master cylinder.

Vehicle brake system with an electric servomotor and hydraulic reaction piston

Braking system with master cylinder (), decoupled from the brake pedal and hydraulic brake booster (), comprising A controlled hydraulic link () connects the boost chamber () and the actuator chamber () and a further controlled hydraulic link () connects the actuator chamber () to the chamber of a brake simulator ().

Brake system with master cylinder, disengaged from the brake pedal, and hydraulic brake booster

Braking system comprising a brake booster with electric motor driving the push rod of the piston of the master cylinder via a ball-screw connection and actuated by a control rod. In the casing connected to the master cylinder, the brake booster comprises an actuator piston guided in translational movement by at least two guide pins which are parallel to the axis of the master cylinder and which is driven in translational movement by a ball screw of which the screw, driven by the motor, is offset with respect to the axis of the master cylinder. The screw collaborates with a nut translationally as one with the actuator piston, and a bore of the actuator piston receives a boost piston equipped with a reaction disc and with a plunger piston connected to the control rod.

Electrically boosted braking system

Brake system comprising a thrust rod () driven by the servobrake () and actuating the piston () of the master cylinder (), the servobrake () being linked by a hydraulic actuator () to the control rod () of the brake pedal (PF). The servobrake () comprises an actuator piston () controlled by an electric motor () via a rack drive ().

Brake system with electric servo brakes

Actuator piston () formed by an injection-molded piece () consisting of a cylindrical body () and a collar () to receive the hydraulic actuator () and the travel detector (). The piece () comprises a shell () covering its front face and receiving the return spring () and the thrust rod (). The actuator piston () includes lugs () engaged behind the lugs () of the body (), by a pivoting movement about the axis. The rotational position is blocked by a locking and guiding sleeve ().

Servo brake actuator piston and servo brake equipped with such a piston

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.

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Cramoisy, France

Bastien Cagnac