Patent ID: 6591606
Filing Date: 2003-07-15
Classification: F01N,F02B

Abstract:
An internal combustion engine including an engine in a portable handheld work apparatus, the internal combustion engine comprising:a cylinder having a cylinder wall; a piston mounted in said cylinder to undergo a reciprocating movement along a stroke path between top dead center and bottom dead center during operation of said engine; said cylinder and said piston conjointly delimiting a combustion chamber; a crankcase connected to said cylinder; a crankshaft rotatably mounted in said crankcase; a connecting rod connecting said piston to said crankshaft to permit said piston to drive said crankshaft as said piston reciprocates in said cylinder; an outlet for conducting oxygen-rich and oxygen-poor exhaust gases away from said combustion chamber; a mixture-preparation unit for supplying an air/fuel mixture; a first set of gas-supplying channels for supplying an air/fuel mixture to said combustion chamber prepared by said mixture preparation device; a second set of gas-supplying channels for supplying oxygen-rich gas to said combustion chamber; said first set of gas-supplying channels and said second set of gas-supplying channels opening into said combustion chamber so as to cause said oxygen-rich gases and said oxygen-poor exhaust gases to alternately flow through said outlet; an exhaust-gas muffler having a housing and an inlet on said housing fluidly connected to said outlet to permit said oxygen-rich and said oxygen-poor gases to alternately flow into said exhaust-gas muffler; said housing having an interior and a discharge opening communicating with said interior; a catalytic converter mounted in said housing between said inlet and said discharge opening; and, buffering means disposed in said housing for temporarily storing said oxygen-rich exhaust gas to thereby even out the oxygen component in the total exhaust-gas flow charging said catalytic converter.