Piezoelectric-hydraulic valve drive, preferably for gas exchange valves in internal combustion engines, has membrane between piezoelectric element, hydraulic chamber housings

摘要

The device has a stacked piezoelectric element (1) drive enclosed by a housing and a chamber filled with hydraulic fluid (5) for increasing the stroke between the valve rod (6) piston surface and the large diameter piezoelectric element. A membrane (2) stretched between the piezoelectric element housing and a housing (4) enclosing the hydraulic chamber is biased towards the piezo-element with application of force to the valve.