Abstract One or more cylinders of a compression-ignition engine are connected to respective supply conduits through control valves normally spring-biased into a closed position. A feed pump periodically delivers fuel under pressure, from a reservoir, to a distributing channel leading to the supply conduit or conduits, this channel also having a return conduit for each cylinder with a bypass valve closed during all or part of the compression stroke of the pump. The closure of this bypass valve, during a gating interval established by an electronic network, causes a pressure buildup in the supply conduit sufficient to open the control valve against the force of its loading spring so that fuel under pressure enters the injector throughout the gating interval whose timing and duration may be determined by one or more operating parameters, such as throttle position and engine speed, fed into the network.
A system for controlling the fuel supply to a compressionignition engine having a plurality of piston cylinders each provided with a fuel injector, comprising: a source of fuel for said engine; a distributing channel having a plurality of branches extending to a drain for excess fuel; engine-controlled pump means for delivering fuel at high pressure to said channel in a succession of compression strokes; a pair of electrically controlled valves disposed in tandem in each of said branches, said pair including a normally open first valve and a normally closed second valve; an extension conduit leading from each branch to a respective fuel injector, said conduit communicating with the corresponding branch at a location downstream of said first valve and upstream of said second valve; and electronic gating means for periodically opening said first valve and concurrently closing said second valve of each branch in cyclic succession during successive injection intervals for admitting fuel from said channel to the respective injectors.
Claim 2
Independent Claim
161 words
A system for controlling the fuel supply to a compressionignition engine having a plurality of piston cylinders each provided with a fuel injector, comprising: a source of fuel for said engine; a distributing channel having a plurality of branches extending to a drain for excess fuel; engine-controlled pump means for delivering fuel at high pressure to said channel in a succession of compression strokes; a pair of electrically controlled valves disposed in tandem in each of said branches, said pair including a normally open first valve and a normally closed second valve; an extension conduit leading from each branch to a respective fuel injector, said conduit communicating with the corresponding branch at a location downstream of said first valve and upstream of said second valve; and electronic gating means for periodically opening said first valve and concurrently closing said second valve of each branch in cyclic succession during successive injection intervals for admitting fuel from said channel to the respective injectors.
Claim 3
Dependent Claim
21 words
A system as defined in claim 1 wherein said channel is provided with pressure-controlling valve means upstream of all said branches.
Claim 4
Dependent Claim
19 words
A system as defined in claim 1 wherein said first and second valves are provided with a common housing.