US 5,441,030 AGranted

Fuel injection system for two-stroke cycle engine

OwnerRyuji Satsukawainventor

Life of this patent

Estimating the term…

Loading patent…

Abstract

A fuel injection system for a two-stroke cycle engine capable of keeping an air-fuel ratio of an air-fuel mixture for combustion at a low engine speed optimum to improve startability of the engine in a cold district. The system includes a low-speed basic injection time increment setting unit for setting a low-speed basic injection time increment Tfi depending on an engine speed N and a throttle opening .alpha., a low-speed crankcase temperature correction factor setting unit for setting a low-speed crankcase temperature correction factor KLc, time correction factor setting units for setting a time correction factor Kt which is decreased with an increase in crankcase temperature, as well as with lapse of time, and a low-speed injection time increment setting unit for setting a low-speed injection time increment TiL by multiplying the increment Tfi by the correction factors KLc and Kt. A fuel injection time setting unit is arranged so as to add the increment TiL to basic fuel injection time Tp to provide injection time Tp+TiL, which is then corrected depending on various conditions to operate fuel injection time Ti.

Claims5

Dependent claims

A fuel injection system for a two-stroke cycle engine, comprising:

a basic fuel injection time setting means for setting basic fuel injection time Tp using an engine speed N of the two-stroke cycle engine and a throttle opening .alpha.;
a fuel injection time setting means for correcting said basic fuel injection time Tp depending on various conditions to set fuel injection time Ti;
an injector drive means for feeding an injector with a fuel injection pulse Pi of a pulse width equal to said fuel injection time Ti set by said fuel injection time setting means;
a low-speed basic injection time increment setting means for setting a low-speed basic injection time increment Tfi corresponding to an increment of the fuel injection time at a low engine speed depending on said engine speed N and throttle opening .alpha.;
and
a low-speed injection time increment setting means for multiplying said low-speed basic injection time increment Tfi by a predetermined correction factor obtained using a temperature Tcc of a crankcase of the engine and elapsed time t as a parameter, to thereby provide a low-speed injection time increment TiL which is decreased with an increase in crankcase temperature Tcc, as well as with the lapse of time;
said fuel injection time setting means further correcting injection time Tp+TiL, obtained by adding said low-speed injection time increment TiL to said basic fuel injection time Tp, depending on various conditions, to thereby subject said fuel injection time Ti to an operation.

4 more elements

Dependencies are inferred from the claim text.