Robert Boschgmbh

Laurent Lhuillier

Olivier Bernadat

Antony Auguste

Marc Rodriguez

Daniel Grech

Carole Charpentier

Bastien Cagnac

Francois Gaffe

François Gaffe

Marc Noblet

Julien Gateau

Matthias Kistner

Serge Aquino

Nicolas Quiniou

Alain Benoit

Masaki Shiwa

Jean-Pierre Michon

Andrew Paul Wasson

Eligiusz Stefaniak

Enzo Perini

Takeshi Kaneko

Constantin Van De Velde

Thierry Coquart

David Bazaud

Tim Albert

Sebastien Dusch

Bruno Foirestier

Cyril Pechaud

Alain BENOÎT

A master cylinder is described. The master cylinder includes a chamber delimited by a piston and supplied from a brake fluid reservoir installed on the top of the master cylinder by an end fitting engaged in a nozzle on the body of the master cylinder. The piston has a nose of reduced section upstream of its skirt guided in the bore hole of the master cylinder and the nozzle is connected to the chamber by a drill hole issuing into the chamber at least partly upstream of the piston in rest position. A valve module is installed in the drill hole to manage communication between the reservoir and the chamber as a function of the position of the piston and the pressure in the chamber with respect to the pressure in the reservoir.

Master cylinder for a braking system

Brake fluid reservoir valve for installation in the reservoir's outlet tube. It includes an outer sleeve fixed in the reservoir tube and equipped with an outer stop and a hollow piston housed in the sleeve. The top of the piston is closed and bordered by a groove accommodating an o-ring seal that rests upon the upper edge of the sleeve whenever the piston enters the sleeve. The piston has windows beneath the groove communicating with the interior of the piston and lugs near its lower extremity. Openings are provided in the extension of the piston beneath the lugs. A compression spring is inserted between the piston and the outer sleeve, between the stop and the lugs.

Brake fluid reservoir valve for a master cylinder

A servo brake includes a thrust unit connecting a servo-piston to a primary piston in an actuation direction. The thrust unit includes a plunger with a front end in the form of a spherical cap and pressed in a cup of the primary piston and a rear end that includes a ball joint. A bearing has a base pressed on a reaction disc and a sleeve that receives the ball joint of the plunger.

Electromagnetic servo brake

A primary piston of a tandem master cylinder includes: a body provided with a skirt, having in the rear thereof a cavity for the plunger and the push rod connected to the brake pedal and in the front a cavity defining the primary chamber. The piston is made of a plastic material and at least one magnet is built into the body of the piston.

Primary piston of a tandem master cylinder

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

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 primary piston composed of a skirt and an intermediate back wall having a rear face receiving the servobrake thrust rod and a forward face for the telescoping rod and the spring pushing the secondary piston. The front of the skirt has longitudinal grooves open in front and closed in the rear. The thickness of the skirt beneath the grooves and the part of the skirt between two successive grooves in the peripheral direction form a front face enabling the principal piston to push the secondary piston. The principal piston is made of a single piece of plastic material.

Primary piston for a tandem master cylinder and tandem master cylinder equipped with such a primary piston

A master-cylinder seal housed in a groove around a piston has a core connected to three annular and concentric lips. The core rests against a side of the groove and has: a surface provided with an interior edge followed by a peripheral platter cut by at least one channel, and an exterior crown provided with a connection zone formed by an interruption in the crown and deformable due to pressure within the seal to recreate the crown's continuity and impermeability while facilitating purging the brake system when there is no pressure in the channel and the connection zone.

Brake system master-cylinder seal

A primary piston of molded plastic material equipped with a metallic insert and having grooves, mounted in a master cylinder comprising at least a primary piston and a secondary piston mounted in the bore hole of the master cylinder. These pistons can create pressure, respectively, in a primary pressure chamber and in a secondary pressure chamber due to the action of a push rod on the primary piston.

Plastic primary piston with insert for a tandem penetration-type master cylinder and a master cylinder equipped with such a piston

A brake fluid reservoir is connected to a master cylinder by a neck which is arranged in an upper chamber of the master cylinder. Holes extend through a surface of a piston, opening to a pressure chamber. The piston extends through a bore hole of the master cylinder. A drill hole extends through an interior wall of the master cylinder, opening into the bore hole, thereby providing communication between the fluid reservoir and the pressure chamber. A floating orifice plate is arranged within the upper chamber, between the neck of the brake fluid reservoir chamber and the drill hole, such that the orifice plate forms a baffle that limits a flow rate of liquid from the brake fluid reservoir chamber to the pressure chamber; and includes supports pressing against a surface of the interior wall of the master cylinder and arranged around the first side of the drill hole.

Master cylinder with flow limitation system

A master cylinder includes at least one primary piston and one secondary piston installed in the bore hole of the master cylinder, which pistons are used to create pressure. The primary piston has a body of molded plastic material and is equipped with a functional metallic insert which has the shape of a spherical cap capable of accommodating a push rod.

Plastic primary piston with stamped sheet-metal functional insert for penetration-type tandem master cylinder and master cylinder equipped with such a piston

A master cylinder having a primary piston and a secondary piston is described. The secondary piston is realized of plastic material; it is composed of a skirt and an end wall. The forward edge of the skirt is equipped with longitudinal slots intended to cooperate with the resupply seal to resupply the secondary pressure chamber and ensure operation in rest position whenever the brake circuit is in ESP mode. Supply occurs from the supply chamber, which is connected to the brake fluid reservoir.

Tandem master cylinder secondary piston and master cylinder equipped with such a secondary piston

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

A method is described for detecting an incorrectly installed seal in a master-cylinder having a seal. The master cylinder is subjected to a pressure comprised between approximately 0.3 and 0.6 MPa at the conclusion of master-cylinder assembly and, if there is a drop in the pressure, the seal is considered to have been installed in reverse in the groove of the master cylinder.

Method for detecting an error in the installation of a seal in a master cylinder

A primary piston is described of molded plastic and equipped with a functional metallic insert and at least one groove. The primary piston is installed in a master cylinder comprising at least the primary piston and a secondary piston, these being mounted in the bore hole of a master cylinder. These pistons can create pressure in a primary pressure chamber and a secondary pressure chamber, respectively, due to the action of a push rod on the primary piston.

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Le Blanc Mesnil, France

Laurent Lhuillier