Patent ID: 7234650
Filing Date: 2007-06-26
Classification: F02M,F16K

Abstract:
1. A three-way valve driven by a piezoelectric actuator comprising: a valve chamber having a low-pressure port connecting to a low-pressure conduit, a high-pressure port connecting to a high-pressure conduit, and a control port connecting to a pressure-controlling chamber; a control valve installed in the valve chamber and closing one of the low-pressure port and the high-pressure port; a guide hole communicating with the valve chamber via the high-pressure port; a guide portion which is slidably installed in the guide hole and connected to and movable together with the control valve, the guide portion receiving a fuel pressure at the high-pressure port in a valve-closing direction of the high-pressure port; an actuator having a piezoelectric device for extending the control valve to open the low-pressure port and close the high-pressure port by transmitting a displacement of the piezoelectric device thereto; and a by-pass conduit providing communication between the valve chamber and an oil-accumulating chamber which is defined by a space in the guide hole that is opposite the guide portion from the valve chamber.