DIESEL ENGINE WITH CATALYTIC CONVERTER

摘要

Diesel engine with unit injectors (6) and a catalytic converter (61) arranged in the engine exhaust system (60), for reaction with uncombusted fuel. The injectors have spill valves (9), which in their closed position build up pressure in the injectors, and needle control valves (9), which in their closed position keep the needle valves of the injectors closed and which, when they are open, open the needle valves. The unit injectors have pump plungers, which are driven by individual cam elements (12) whit a cam curve (13) shaped so that a pressure is maintained in the injects for so long a period during one cycle that injection of fuel is permitted at least when an associated exhaust valve in the combustion chamber begins to open so late during the expansion stroke and temperature drop, that fuel after injection is not combusted in the cylinder but reaches the catalytic converted uncombusted. A control unit (15) controls the spill valve and the needle control valve (9) in response to various control parameters, so that at least a first amount of fuel can be injected during the engine compression stroke for the ordinary combustion in the combustion chamber and that at least one additional amount of fuel can be injected later for transport with the exhaust to the catalytic converter.