Fuel injection device for internal combustion engines
AssigneeIsuzu Motors Limited
InventorShigeaki Horiuchi
Life of this patent
Estimating the term…
Abstract
This fuel injection device extends the duration which elapses from the injection starting point to the point of maximum lift of the needle valve to lower the initial injection ratio, thereby reducing NO.sub.x emissions. Further, the time which elapses from the starting point of injection termination to the nozzle hole closing point is decreased to ensure positive fuel cutoff, increase the injection rate immediately before the end of the injection process and reduce emissions such as soot and HC. In this fuel injection device, the passage for supplying high-pressure fuel into the balance chamber is formed larger than the orifice for discharging the fuel from the balance chamber, and a normally open check valve is provided in the annular chamber.
Claims5
A fuel injection device for internal combustion engines comprising:
- a main body having nozzle holes to inject fuel;
- a valve assembly having a needle valve and a control piston connected to the needle valve, body reciprocating in the main body;
- a fuel chamber formed in the main body around the valve assembly;
- a balance chamber formed in a control sleeve fixed in the main body to control a lift of the valve assembly by applying a fuel pressure to the control piston;
- an annular chamber formed in the main body and communicating with a high-pressure fuel source;
- a supply passage communicating with the annular chamber to supply the high-pressure fuel to the balance chamber;
- an exhaust passage having an orifice to release the fuel from the balance chamber;
- an actuator to drive a control valve to open and close the exhaust passage;
- and
- a normally open check valve provided in the annular chamber and urged at all times by a spring force in a direction that opens the supply passage;
- wherein the supply passage has a greater passage cross section than that of the orifice of the exhaust passage.
Dependencies are inferred from the claim text.