Three-way valve and fuel injection device having the same

摘要

A three-way valve having a valve chamber with a low-pressure port, a high-pressure port, and a control port is provided. The three-way valve also has a control valve installed in the valve chamber for closing one of the low-pressure port and the high-pressure port. A guide hole communicates with the valve chamber via the high-pressure port. A guide portion is slidably installed in the guide hole and moves together with the control valve. The guide portion further receives a fuel pressure at the high-pressure port in a closing direction of the high-pressure port. The control valve is driven by a piezoelectric actuator to open the low-pressure port and close the high-pressure port. The valve chamber communicates with an oil-accumulating chamber via a by-pass conduit. The oil-accumulating chamber is defined within the guide hole and is located opposite the guide portion from the valve chamber.