| 摘要 |
In a blow-by gas processing circuit for an internal combustion engine which is applicable to various types of internal combustion engines regardless of whether or not their intake pipes are long, a carburetor having an intake passageway extending laterally is connected to one side surface of the internal combustion engine with an insulator member interposed between the carburetor and the one side surface, and an air cleaner placed above the carburetor is connected to an upstream end of the carburetor, wherein the blow-by gas processing circuit includes: a blow-by gas lead-out pipe rising upward from the internal combustion engine, and extending along one side surface of the air cleaner; an upper pipe bending laterally from an upper end of the blow-by gas lead-out pipe, and extending along the one side surface; a descending pipe bending downward from an extremity portion of the upper pipe, and extending along the one side surface so as to reach a purification completion chamber of the air cleaner; a branch pipe branching off downward from an intermediate portion of the upper pipe, and connected to a blow-by gas outlet port opened to an intake passage penetrating the insulator member; and a control valve placed in an upper portion of the branch pipe, and configured to open in accordance with a rise in boost negative pressure of the internal combustion engine. |
