Air/fuel mixture preheater plug for e.g. direct injection oil engine, has heating head comprising set of projections extending from body of head to increase wetted surface of heating head

摘要

The plug (10) has an upper plug fixation part (22), and a lower heating part (26) equipped with a heating head (30) which is heated using an electrical resistor (28). The head has a cylindrical body (31) extended axially inside a combustion chamber (20) and a wetted surface (32) which is in contact with air/fuel mixture. The heating head comprises a set of projections (34) e.g. annular rib (34a), extending from the body of the head to increase the wetted surface of the heating head.