Solenoid valve and fuel injector for internal combustion engine using the same

摘要

A rapid-response solenoid-operated fuel injector for diesel engines is provided which includes a solenoid-operated valve member and a needle valve. The solenoid-operated valve member selectively establishes fluid communication between a fuel inlet and a fuel outlet. The needle valve is moved to selectively open and close a spray hole through which the fuel is sprayed. The solenoid-operated valve member is exposed at its head to the fuel pressure within a pressure control chamber supplied from the fuel inlet and has formed therein a pressure balancing chamber communicating with the pressure control chamber through a first orifice. The pressure of fuel within the pressure balancing chamber acting on the solenoid-operated valve member to block the fluid communication between the fuel inlet and outlet is balanced with the pressure of fuel within the pressure control chamber acting on the solenoid-operated valve member to establish the fluid communication between the fuel inlet and outlet. The pressure control chamber communicates with the fuel inlet through a second orifice which is smaller in diameter than the first orifice. <IMAGE>