Starting aid for internal combustion engines

Claim 1

For use in preheating combustion air compressed with an internal combustion injection engine without a carburetor, a starting aid which includes in combination: a straight air intake pipe leading to at least one branch pipe to a combustion cylinder, for conveying air to said engine, said air intake pipe being provided with an outwardly bulging section in a straight wall upstream of the air flow to said branch to form a chamber opening into the air intake pipe, at least one flame heater plug extending from the outside of the upstream end of said bulging section into the interior of said upstream end of said outwardly bulging section of said air intake pipe and disposed entirely within said chamber for preheating the entire air flow in said air intake pipe to a very high temperature at a value still below that for self ignition of a fuel mixture which is to be avoided, said bulging section being largest in cross section at its upstream end and tapering in the direction of air flow to a smaller cross section at its downstream end, so that the heated air from said flame heater plug will enter directly into said air intake pipe, and an apertured plate with a plurality of apertures throughout its length placed in the opening where said bulging section bulges out from said air intake pipe to separate said chamber from the air flow in the adjacent portion of said air intake pipe so the air flow does not interfere with the action of the flame heater plug and to maintain a reduced temperature while permitting communication therebetween through the apertures of said apertured plate to assure preheating stability without extinguishing said flame heater plug regardless of low starting temperatures and regardless of increasing speed to attain operation with smoke-free combustion, a portion of said air in said intake pipe entering through some of said perforations for combustion in said bulge and exiting said bulge through others of said perforations.