Volkswagenwerk Aktiengesellschaft

Volkswagen Ag

Gunter Leineweber

Rolf Warnecke

Heinz Ruhmer

A hydraulic amplifier valve assembly having an input end (where, for example, a brake pedal force may be applied) and an ouput end includes a valve housing and an amplifier piston which is slidably received in the housing only along that end portion which is oriented towards the input end. The other terminal length portion of the amplifier piston which is oriented towards the ouput end continuously projects from the valve housing and carries a pressure conduit nipple and a return conduit nipple. The valve housing is a sheet metal construction formed of a plurality of interconnected elements. This housing includes an outer, rotationally symmetrical, generally cup-shaped sheet metal housing shell and a sheet metal inner cylinder sleeve which extends inside the housing shell coaxially therewith and at a radial distance therefrom, approximately over the entire length of the housing shell. The input-side end of the cylinder sleeve is connected to the housing shell in such a manner that an annular space, which is hermetically sealed towards the input end, is defined between the housing shell and the cylinder sleeve. The amplifier piston has a tubular portion which is open towards the input end and which is slidably received in the annular space.

Hydraulic amplifier valve assembly

A pressure-unbalanced hydraulic amplifier valve assembly has an axially slidable amplifier piston and a control plunger axially slidably arranged in the amplifier piston with a loose fit to permit a slight radial movement thereof in the amplifier piston. For providing a tight seal in the zone of control ports arranged in the amplifier piston, the control plunger is urged in that zone radially against the amplifier piston by a transverse piston continuously exposed to the system pressure. A pressure piston engages one end of the control plunger and is exposed to an external force (such as a braking force applied by a pedal) for axially displacing the control plunger. In order to eliminate undesired axial force components from the force applied by the transverse piston, a force-transmitting ball contacts the transverse piston and an inner wall of the control plunger forming a throughgoing axial bore and constituting an axially linear track for the ball. In order to eliminate undesired transverse force components from the force exerted by the pressure piston on the control plunger, these two components contact one another by means of mutually transversely arranged pins which are solely in a point contact with one another.

Unbalanced hydraulic amplifier valve assembly

An unbalanced hydraulic valve assembly includes a first plunger element slidably and transversely displaceably received in a second plunger element wth a loose fit; a work chamber; a pressure supply conduit provided in the valve assembly for introducing pressurized hydraulic fluid thereinto; a control port arrangement in one of the plunger elements in an asymmetrical relationship relative to the circumference of the plunger elements. The control port arrangement permits or blocks flow from the pressure supply conduit to the work chamber dependent upon the relative axial position between the plunger elements. A force transmitting member is supported in the second plunger element for displacement transversely to the direction of relative axial motion between the plunger elements. The force transmitting member engages the first plunger element and is exposed to pressurized hydraulic fluid for pressing the first plunger element against an inner wall face of the axial bore provided in the second plunger element. The first plunger element and the second plunger element are free from annular seals between themselves.

Growing community of inventors

Gifhorn, Germany

Gunter Leineweber