Fuel injection means for a diesel engine

Claim 2

Apparatus for a vehicle engine fuel injection comprising: a fuel injector pump having a pump cylinder with a side fuel port and a pump plunger longitudinally and rotationally movable in said cylinder to open and close said port, and means including in the side of said plunger single injection terminating slanting slot communicating internally of said plunger with its fuel compressing end for regulating the time of fuel communication between said end and port in dependence upon both the instant relative height and rotational angle of said port and plunger, said means further including means operative on said plunger for causing said slot to be out of communication with said port during engine starting times only for separated periods of time during spaced first and last stages of each movement of said plunger from its lowermost to uppermost positions in said cylinder to provide for fuel injection during those periods but not between them and for causing said slot to be out of communication with said port during normal engine operating times only during a portion of said first stage of movement of said plunger to provide for fuel injection only during said first stage portion during normal engine operation, said means operative on said plunger including means for causing during a first portion of said last stage an auxiliary fuel injection in timed relation with a suction stroke or the beginning part of a compression stroke in each engine combustion cycle while the top dead center that is reached by said plunger at the end of said first stage is maintained between said first and last stages for substantially the whole range of combustion and exhaust strokes in each engine cycle.

Claim 3

Fuel injection means for a diesel engine in accordance with claim 1, said injection means further comprising means for rotating said plunger pump about its longitudinal axis by a predetermined angle during change-over from the engine starting to the normal engine operation so that the relative position of said fuel intake and output port and said injection terminatinG slanted groove can be properly changed in the direction of pump plunger axis.

Claim 4

Apparatus as in claim 1 wherein said means operative on said plunger includes plunger rotating and cam lifting means and the latter has a cam surface with first and third portions to effect said first and last stages of movement and an intermediate portion of constant radius to maintain the plunger at the top position caused by the said first portion of the cam surface.

Claim 5

Apparatus as in claim 3 wherein said cam first portion surface in conjunction with said rotating means causes said fuel injection period during said first stage to be longer during engine starting times than during engine operating times.

Claim 6

Apparatus as in claim 4 wherein the time said slot is out of communication with said port during said last stage movement of the plunger during engine start up times is relatively short compared to either of said first stage fuel injection periods so as to cause a relatively short auxiliary fuel injection period only during engine starting times.

Claim 7

Fuel injection for a diesel engine comprising: a fuel injection pump having a pump cylinder with an upper injection port and a pump plunger longitudinally slidable in said pump cylinder between said port and a lower position, rotatable cam means for longitudinally lifting said pump plunger in said pump cylinder from said lower position, said cam means including a cam surface having a first portion for producing a first stage of plunger lift to provide a first period for main fuel injection, a second portion spaced from said first portion for producing a second stage of plunger lift to provide during a later time a second period for auxiliary fuel injection, and a third portion for producing during a third intervening period a third stage of plunger lift constantly at the height of the top dead center of said first stage of plunger lift for a predetermined angle of cam means rotation between said two stages, said auxiliary fuel injection being effected in timed relation with the suction stroke or the beginning part of the compression stroke in each engine combustion cycle and said top dead center of said first stage, that is operative preceding said auxiliary fuel injection, being maintained in substantially the whole range of combustion and exhaust strokes in each engine cycle, said pump cylinder being provided with with a fuel intake and output port disposed between said injection port and lower plunger position, said pump plunger being provided at its surface with an injection terminating slanted groove arranged to be communicatable with said fuel intake and output port during part of the longitudinal movement of said plunger, and having a longitudinal bore communicated with said slanted groove for opening to the end of said plunger, and control means for rotationally driving said pump plunger in said pump cylinder according to engine operation to cause A. at engine starting times, said ports to be in communication with each other directly for a first portion of said first stage and indirectly through said slanted groove and bore during a second portion of said second stage to prevent fuel injection during said portions and to be out of communication with each other during a second portion of said first stage so as to effect said main fuel injection period and also to be out of communication during a first portion of said second stage so as to effect said auxiliary fuel injection period, and B. to cause during normal engine operation, said ports to be in communication with each other during all three of said stages except for a main fuel injection period during said first stage.

Claim 8

Fuel injection for a diesel engine comprising: a fuel injection pump having a pump cylinder with an upper injection port and a pump plunger longitudinally slidable in said pump cylinder between said port and a lower position, rotatable cam means for longitudinally lifting said pump plunger in said pump cylinder from said lower position, said cam means including a cam surface having a first portion for producing a first stage of plunger lift to provide a first period for main fuel injection, a second portion spaced from said first portion for producing a second stage of plunger lift to provide during a later time a second period for auxiliary fuel injection, and a third portion for producing during a third intervening period a third stage of plunger lift constantly at the height of the top dead center of said first stage of plunger lift for a predetermined angle of cam means rotation between said two stages, said auxiliary fuel injection being effected in timed relation with the suction stroke or the beginning part of the compression stroke in each engine combustion cycle and said top dead center of said first stage, that is operative preceding said auxiliary fuel injection, being maintained in substantially the whole range of combustion and exhaust strokes in each engine cycle, said pump cylinder being provided with with a fuel intake and output port disposed between said injection port and lower plunger position, said pump plunger being provided at its surface with an injection terminating slanted groove arranged to be communicatable with said fuel intake and output port during part of the longitudinal movement of said plunger, and having a longitudinal bore communicated with said slanted groove for opening to the end of said plunger, and control means for rotationally driving said pump plunger in said pump cylinder according to engine operation to cause A. at engine starting times, said ports to be in communication with each other directly for a first portion of said first stage and indirectly through said slanted groove and bore during a second portion of said second stage to prevent fuel injection during said portions and to be out of communication with each other during a second portion of said first stage so as to effect said main fuel injection period and also to be out of communication during a first portion of said second stage so as to effect said auxiliary fuel injection period, and B. to cause during normal engine operation, said ports to be in communication with each other during all three of said stages except for a main fuel injection period during said first stage.