Patent ID: 8402881
Filing Date: 2013-03-26
Classification: B22D,C22C,F02F

Abstract:
1. An insert casting structure comprising a cylinder liner made of cast iron and inserted within aluminum alloy through insert casting and having a plurality of projections on an outer circumferential surface of the cylinder liner, wherein a surface area of the outer circumferential surface of the cylinder liner having the projections is 140 to 230 percent of the surface area of the outer circumferential surface of a cylinder liner having no projections, the surface area ratio is calculated by the following formula A when set so that an average height of projections is H mm, a number of projections is N, and a projection area ratio is B, a height of projections is 0.2 to 0.7 mm, a number of projections is 70 to 150 per cm when the thickness of a cast iron portion to the base of the projection is set as L1, and the thickness of an integrated piece made up of the cast iron portion and an aluminum alloy portion is set as L2, the thermal conductivity is 35 to 80 W/mK when measured under the condition of L1/L2=0.45.