| 摘要 |
PURPOSE:To obtain products in high accuracy, by inhibiting the distortion of the press-in of the sleeves of cylinder holes by pressing in a sleeve after boring one cylinder hole and by successively repeating said work to the following cylinder holes. CONSTITUTION:In a multicylinder cylinder block in a light alloy provided with a number of cylinder holes 10a-10c, lower holes 10a'-10c', to which grinding allowance for boring is shaped, are beforehand drilled to each cylinder hole 10a- 10c in a line. A cylinder hole 10a'', which true degree of the circle is heightened, is formed by first boring the cylinder hole 10a, and a sleeve 20 is pressed in the hole. Even if the next cylinder hole 10b (the lower hole 10b') shrinks in the cylinder row direction as shown in 10b'' by the press-in of the sleeve 20 and the true degree of the circle of an inner diameter is distorted to some extent, a cylinder hole with the high true degree of the circle can be shaped by boring grinding allowance as shown in a chain line 10b'''. Products can be obtained by successively repeating the same work as mentioned above about the following cylinder holes. |
