PURPOSE: To stabilize a temperature of air to be discharged by an air pump as well as to cool this pump with certainty by driving the air pump feeding an injector with air directly by dint of engine speed output, making an engine into a liquid-cooled one, and cooling the air pump with an engine coolant.
CONSTITUTION: Rotation of a crankshaft 62 of an engine 36 is transmitted to a plunger type air pump 72 and a gear type fuel pump 74 via a toothed belt 66 and two one-way clutches 68, 70. An engine coolant cooled in a radiator 48 enters a water pump 96 from a lower part of the radiator 48, and it is fed to each part of the engine 36. In addition, a part of the coolant discharged out of a cylinder 40 is guided into the air pump 72 by a pipe 100, and after this pump 72 is cooled, it is put back to an upper part of the radiator 48 by a pipe 102.
KINOSHITA TOSHIO
ISAKA YOSHIHARU
