Unleaded gasoline in-cylinder direct injection gasoline engine

摘要

PROBLEM TO BE SOLVED: To decrease the amt. of environmental pollutants contained in an engine exhaust gas and simultaneously improve the durability of a gasoline engine of a direct injection type by using an unleaded gasoline contg. a specified amt. of a specific oxygen-contg. compd. ;SOLUTION: Based on the total amt. of an unleaded gasoline, a 2-15C oxygen- contg. compd. in an amt. of 0.1-15 mass % (in terms of elemental oxygen) is incorporated into the gasoline. Though the oxygen-contg. compd., as far as it has 2-15 carbon atoms together with an oxygen atom or atoms, may have any chemical structure, it usually has at least one kind of oxygen-contg. group selected from among hydroxyl, ether, and carbonyl groups in the molecule. An example of the compd. is represented by the formula: R¹-O-(R²-O)_n-R³ [wherein R¹ and R³ are each independently H or a 1-15C hydrocarbon group; R² is a 12-4C alkylene; and n is an integer of 0-7 provided that the number of total carbon atoms in the molecule is 2-15 and that when n is 0, then R¹ and R³ are not simultaneously H].;COPYRIGHT: (C)1999,JPO