The present invention relates to a cylinder liner structure for an engine, the through portion 11 through vertically arranged and an engine block 10 having a flat planar portion 12, the upper end edges of the through portion 11 and the at the top of the inner insert portion 21 and the inner insertion portion (21) is arranged inserted into the through-portion 11 of the engine block (10) only to such that rests on the flat part 12 of the engine block 10 the external exposed part 23 the outer peripheral side of the teokbu 22 is provided and the end of teokbu 22, cylinder liner 20 and the cylinder liner 20 upper end portion is made of an external exposed part 23 extending above the is in that configuration, including the water jacket 30 is disposed the engine, the reinforcing portion 40 to the inner peripheral surface of the outer exposed portion 23 of the cylinder liner 20 is further provided with a structure.
Therefore, providing a reinforcing outer to the inner circumferential surface of the cylinder liner to the exposed portion, but the reinforcement is a shrink fit (shrink ?? fit) such that the compressive residual stress is generated in the reinforcement portion while pressing the inner circumferential surface part exposed outside of the cylinder liner system by so binding, by default, to be able to be made to improve the reliability of the product to ensure as the rigidity reinforcement for the unit top exposure of the cylinder liner made of crack prevention is damaged or deformed, and also, the improved writing of the cylinder liner and the overall and so it could seek a reduction of the engine size, but also to obtain an effect such as to cause improved cooling performance by the reinforcement.