Abstract:
Ce dispositif comprend un maître cylindre piloté par un organe de commande (20), un servomoteur pneumatique (14), un piston 22, un premier (VE1) et second (VE2) éléments de vanne d'équilibrage des premiers (VA1) et second (VA2) éléments de vanne d'admission et un support tubulaire (44) muni de deux parties (44A, 44B) mobiles l'une par rapport à l'autre de façon à régler la longueur de ce support. Les éléments (VE1, VE2) de vanne d'équilibrage sont portés par une partie d'équilibrage (44B) du support et le piston pneumatique (22). Les éléments (VA1, VA2) de vanne d'admission sont portés par l'organe de commande (20) et une partie d'admission (44A) du support. Les deux parties (44B, 44A) du support sont reliées entre elles par des moyens (52) de réglage de leur écartement en fonction de la puissance de l'effort appliqué à l'organe de commande (20).
Abstract:
Servomoteur pneumatique d'assistance au freinage, en particulier pour véhicule automobile, comprenant un piston (22) monté entre une tige de commande (24) actionnée par une pédale de frein et une tige de poussée (34) actionnant un piston d'un maître-cylindre de freinage, et des moyens pour augmenter l'assistance au freinage lors d'un freinage d'urgence, comprenant une douile cylindrique (46) montée axialement coulissante de façon étanche ô l'intérieur du piston (22), retenue en position de repos par des moyens de blocage (58) et libérée pour repousser le clapet (56) d'une valve 3 voies et augmenter l'alimentation en air atmosphérique du servomoteur quand la tige de commande (24) est déplacée à une vitesse supérieure à une valeur prédéterminée.
Abstract:
The invention relates to a method for controlling the braking device (12) of a vehicle (10) in order to assist the driver during an emergency braking situation. The invention comprises an electronic control unit (58) for the braking device (12) which uses representative data, in particular, braking status data, in order to activate an emergency braking strategy. The invention is characterised in that to activate the emergency braking strategy, the electronic control unit (58) employs a control law which is a second order fuzzy relationship, linking each braking status with a degree of emergency brake activation, the value of which varies linearly between 0 and 1 so as to activate the emergency braking strategy when, during a number n of calculation steps, the degree of activation has n increasing or equal values, which are not equal to zero, the nth value being equal to 1.
Abstract:
The invention concerns a brake booster pneumatic actuator (10) for a motor vehicle, comprising a one-way clutch device including a coaxial bushing (58) sliding on a plunger (46), and means axially locking the bushing (58) which can, when an input force is applied at a specific speed on a control rod (38) integral with the plunger (46), lock the bushing (58) in an axial position wherein it locks the piston (22) independently of the control rod (38). The invention is characterised in that the one-way clutch comprises radial obstacle means, in particular an element (72) whereof at least an annular part encloses the bushing (60) and which is elastically returned along a substantially radial direction towards the periphery of the bushing (60) so as to be received in the groove (74) of the bushing (60) and lock the sensor (52), when the input force is applied at a specific speed.
Abstract:
The invention concerns a brake servo unit comprising a piston actuating a master-cylinder, including an elastic return control rod sliding in the piston in accordance with an input force, whereof the end bears a plunger carrying a sliding probe (52) capable of stressing a reaction disc of the actuating rod to transmit to the control rod the piston reaction, and comprising a one-way clutch release device comprising a key and a bushing (58) including the probe (52) which is mounted sliding on the plunger, and which can, when the control rod is actuated at a predetermined speed, lock the bushing (58) relative to the mobile piston independently of the control rod. The invention is characterised in that the bushing (58) comprises first and second adjusting parts (104, 106) plastically deformable in the axial direction to adjust beforehand the servo unit. The invention also concerns a deformation assembly to produce such a bushing (58).
Abstract:
The invention concerns a braking servo unit (10) comprising a piston (22) capable of stressing and slidably receiving an actuating rod (28) of a master-cylinder (36), comprising an elastic return control rod (38), sliding in the piston (22) depending on an input force, at the end of which is arranged a plunger (46) including at its front end a probe (52) capable of stressing a reaction disc (32) provided at the rear of the actuating rod (28) to transmit to the plunger (46) and the control rod (38) the reaction of the actuating rod (28). The invention is characterised in that it comprises a one-way clutch device which is capable, when an input force is exerted at a predetermined speed on the control rod (38), of locking the actuating rod (28) relative to the mobile piston (22) independently of the reaction disc (32), the plunger (46) and the control rod (38).
Abstract:
An air valve assembly (120) is provided for a power piston (114) in a vacuum brake booster including an input element (130) with a hollow axial extension (135). The hollow axial extension (135) includes a retaining portion (166). An output element (140) is provided that includes an input extension (144) slidably positioned within the hallow axial extension (135). The input extension (144) includes an outer groove (146) formed thereon and a ring member (147) is disposed in the outer groove (146). The ring (147) is positioned adjacent the retaining portion (166) to prevent separation of the input element (130) and outer element (140).
Abstract:
The invention relates to a vacuum brake booster (24) with a control valve housing in which an armature (38) is provided that interacts with a permanent magnet (40) and that is rigidly coupled on the one hand with the input member (26) in the direction of actuation and on the other hand with the first valve seat (64). A spring (42) prestresses the armature (38) against the direction of actuation and maintains it in the initial position of the control valve (22) at a first distance from the permanent magnet (40). When approaching the permanent magnet (40), the armature (38), as soon as a predefined second distance that is smaller than the first distance is reached, is pulled by the permanent magnet (40) against the force which the spring (42) exerts on the armature (38), thereby releasing the rigid coupling with the input member (26) in the direction of actuation so that it contacts the permanent magnet (40). In order to dampen any undesired knocking sounds, the spring (42) that prestresses the armature (38) against the direction of actuation is mechanically coupled with the input member in such a manner that it dampens the return movement of the input member (26) that is caused when the armature (38) is released from the permanent magnet (40) before the input member (26) has completed the return movement that is maximally possible relative to the control valve housing (24).