PRETREATMENT METHOD BEFORE THERMAL SPRAYING OF INNER SURFACE OF CYLINDER, PRETREATED SHAPE OF INNER SURFACE OF CYLINDER BEFORE THERMAL SPRAYING, AND METHOD FOR TESTING PRESSURE LEAKAGE IN CYLINDER

摘要

PROBLEM TO BE SOLVED: To appropriately perform the pressure leakage test and the inside diameter measurement by using an end in the axial direction of an inner surface of a cylinder, and to prevent peeling of a spray deposit film at the end in the axial direction while enhancing the adhesiveness of the spray deposit film by roughening the inner surface of the cylinder.;SOLUTION: A roughened surface 9 is formed as a pretreatment before depositing a spray deposit film 60 on a cylinder bore inner surface 5. Any roughened surface 9 is not formed on an end on a crank case side of the cylinder bore inner surface 5, but a resin-made coating layer 29 is deposited on this part. A similar upper coating layer 4i is also deposited on an upper surface of a cylinder block 1. The pressure leakage test in the cylinder bore 3 is carried out by a pressure leakage testing machine 31 by using parts for forming the coating layers 29, 49, and the inside diameter is measured by a gap sensor 53. Thereafter, any spray deposit film deposited on the cylinder bore inner surface 5 is not deposited on the coating layers 29, 49, but deposited only on a part forming the roughened surface 9 with high adhesiveness.;COPYRIGHT: (C)2008,JPO&INPIT