초록 ▼

An improved hydraulically-actuated fluid injector system comprises a hydraulically-actuated fuel pressurization member, a fluid storage chamber, and a direct-operated check. Pressurization of fluid in the storage chamber begins before the start of fluid injection. Fluid injection begins by hydraulic

An improved hydraulically-actuated fluid injector system comprises a hydraulically-actuated fuel pressurization member, a fluid storage chamber, and a direct-operated check. Pressurization of fluid in the storage chamber begins before the start of fluid injection. Fluid injection begins by hydraulically unbalancing the check. Fluid injection ends by hydraulically balancing the check to allow a biasing device to close the check. Preferably, actuating fluid that is spilled from the fuel pressurization member (to end fuel injection) is communicated to a hydraulic motor which drives a source of pressurized hydraulically-actuating fluid. The present invention provides improved control of several fluid injection parameters, including higher peak fluid injection capability and less fluid injection pressure drop at the end of injection, resulting in improved engine performance and lower emissions, noise, and wear. The present invention also improves efficiency of operation due to the above hydraulic energy recovery feature.

대표청구항 ▼

A hydraulically-actuated electronically-controlled unit fuel injector for receiving fuel at a low supply pressure and for injecting fuel into a combustion chamber of an engine during an injection sequence, comprising: a source of high pressure hydraulic actuating fluid; an injector body having an in

A hydraulically-actuated electronically-controlled unit fuel injector for receiving fuel at a low supply pressure and for injecting fuel into a combustion chamber of an engine during an injection sequence, comprising: a source of high pressure hydraulic actuating fluid; an injector body having an injector orifice; an intensification and pressurization member disposed in the body for pressurizing fuel to a selectable level independent of and substantially higher than the supply pressure when said intensification and pressurization member is in fluid communication with said actuating fluid source; a valve for selectively opening and closing fluid communication between said actuating fluid source and said intensifier piston; and means disposed in the injector body for injecting pressurized fuel through the orifice into the combustion chamber at any selectable time.