Internal combustion engine

In an internal combustion engine having fuel-air intake means and exhaust gas means, the improvement comprising:

• a casing including a tubular member encircling and attached to a tailpipe enclosed in said exhaust gas means;
• a valve holder closing one end of said tubular member, and a plurality of circumferentially spaced, axially extending apertures formed in said tubular member at a position near said valve holder;
• a poppet valve which is supported at its stem by said valve holder such that said valve is slidable in the axial direction and rotatable with respect to said valve holder and with its head having a diameter slightly smaller than the inner diameter of said tubular member and positioned axially in the area of said apertures;
• an outer tube secured on the outer periphery of said tubular member at a position intermediate of its length by means of an annular member having a plurality of circumferentially spaced axial holes and fixed to the end of said outer tube;
• an inner tube secured at its one end to the periphery of the valve holder and enclosed at its other end by an end plate;
• an adjustable screw secured to a mating threaded hole formed in said end plate;
• and a spring disposed in a chamber defined by said inner tube by said end plate and by an end surface of said valve holder, one end of said spring being secured to the inner end of said adjustable screw and the other end of said spring being secured to the end of the stem of said poppet valve;
• second valve means for variably controlling the amount of fresh air admitted into said fuel-air intake means;
• and,
• means responsive to a manifestation dependent upon the rotational speed of the engine for introducing fresh feed into said intake means,
• whereby the unburnt hydrocarbons in the exhaust gas which have been returned into the combustion chamber of the engine as a result of the resistance applied by the poppet valve and spring are more effectively burnt in the combustion chamber as a result of the fresh air introduced through said second valve means.