CONTROL VALVE FOR HEAT EXCHANGERS IN INTERNAL COMBUSTION ENGINES

摘要

A method of controlling the flow of exhaust gasses in an internal combustion engine in order to allow the engine to be warmed up more quickly in which a heat exchanger is provided in a control duct of the engine exhaust system and a bypass duct is provided through which exhaust gasses can flow without passing through the heat exchanger. The method comprises progressively closing at least partially the bypass duct to divert at least a proportion of the exhaust gasses through the heat exchanger in the control duct thereby causing the engine coolant to extract heat from the heat exchanger. The invention also is concerned with an exhaust system for an internal combustion engine (10) which comprises a heat exchanger (14) provided in a duct (16) of the system, a bypass duct (18) through which, in use, exhaust gasses can flow without passing through the heat exchanger and a control valve (20) to control the flow distribution of exhaust gasses through both ducts and/or to alter the back pressure in the system uptstream of said control valve.