ACTUATION SYSTEM FOR PIEZOELECTRIC FUEL INJECTORS

摘要

Set forth herein are apparatus and systems that compensate for component dimensional changes in fluid control applications, particularly piezoelectric fuel injectors. Specifically, the present invention combines several functions to actuate an inward opening fuel injector with a piezoelectric stack. The arrangement can counteract expansion, amplify motion, compensate for dimensional variations, and/or compensate for fuel pressure variations. Some embodiments can reverse the expansion of the piezoelectric stack by converting it into a pulling force. Other embodiments can amplify and/or reduce component motion within the fuel injector to a desired motion ratio. The device can also compensate for dimensional variations of fuel injector components, such as thermal expansion, manufacturing tolerances, and/or component wear and alter the injector pin closing force based on the amount of fuel pressure.

主权项

1. An actuator system, comprising:
a housing; a working piston within said housing; one or more piezoelectric elements within said housing adjacent said working piston, wherein energizing said piezoelectric elements causes the elements to expand against said piston and move said working piston; an injector pin positioned adjacent to and moveable by said working piston; pin return springs adjacent said injector pin positioned to hold said injector pin in the position adjacent the working piston; and a working chamber adjacent said working piston and said injector pin and positioned to receive said working piston.