Motor vehicle pump under piezo-control

摘要

The two baseplates (1,3) of the pump are joined by connecting element (2) and a piezo-actuator (5) arranged in the element (2) axis as joined at one end to the baseplate (1) and otherwise to a piston (7). The piston moves axially in the connecting element (2) in strokes controlled by the piezo-actuator (5). Pressure space (10) connects (13) via non-return valve (11) to a low pressure valve and to a high pressure valve via a connection (14) closed by a non-return valve (12). A seal (9) fixed round the axis at one end of the piston (7) is so pre-tensioned in dead center between piston and baseplate (3) that the piston endface, seal (9) and plate (3) form the pressure space (10). A seal spaced from the connecting element also forms a pressure space. Several seals can be used, spaced from the element (2) to make up separate pressure spaces, the seals arranged concentrically alongside one another.