KNURLING TOOL FOR FORMING OIL POCKET OF CYLINDER LINER AND KNURLING METHOD THEREOF

摘要

PURPOSE: A knurling tool and its knurling method are provided to expand the applying range of a piston ring and a cylinder by forming a circular dot recess groove within 1 mm inside the inner face of a cylinder liner. CONSTITUTION: A tool(10a) having many compressive needles(11) is stuck to a bar to be rotatable. A cylinder liner is horizontally fixed in a chuck of a knurling tool. A dot type groove is formed in the inner surface of the cylinder liner by rotating the chuck and advancing a feeding bar. The distribution of the uniform lubricant is maintained by many oil pockets with the dot type grooves. Thereby, the life time of an engine is extended.