To provide a method of manufacturing a cylinder for an internal combustion engine free from a step on a scavenge port without increasing the positioning accuracy and the like of a working tool and a worked part not so much, by casting and molding a cylinder material with a scavenge port closing part, and then eliminating (boring) the scavenge port closing part by cutting, discharging, laser machining, and the like.
This cylinder 1 for the internal combustion engine provided with a hollow scavenge passage with an inner wall 10 having the scavenge port 8 opened and closed by a piston 20 is manufactured by casting and molding the cylinder material 1' with the scavenge port closing part 12, then eliminating the scavenge port closing part 12 by cutting, discharging, laser machining and the like to form the scavenge port 8. Material faces 8a, 8c, 8d directly connected to the scavenge port closing part 12 are provided with predetermined intersecting angles α, β, γ in performing the eliminating work.
FUJISAWA TAKASHI
IGUMA MASAHIRO
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