PURPOSE: To reduce the energy required to operate an oxygen content enriching device and improve the fuel consumption of an engine by an arrangement wherein the oxygen content enriching device is actuated when the engine is decelerating, and the oxygen-enriched air obtained during the deceleration is stored temporarily.
CONSTITUTION: An oxygen content enriching device 13 comprises a casing having a material adapted to transmit only oxygen in the air or a greater amount of oxygen than nitrogen, a normal air inlet port 15a, an outlet port 15b for oxygen rich air and an exit port 15c for nitrogen rich air; a pump P1 installed in upstream branch passage 12a; and a pump P2 installed in downstream branch passage 12b. Further, there is provided a control device 23 adapted to make controls so as to supply the oxygen rich air from a storage tank 27 storing the oxygen rich air produced by the oxygen content enriching device 13 into a combustion chamber as and when required.
SHIDAHARA YASUHIRO
OKIMOTO HARUO
