| 摘要 |
PURPOSE:To obtain the titled barrel wherein when a sleeve is mounted in the bore of a barrel, an interposition of a material having a coefficient of thermal expansion greater than those of the sleeve and the barrel and a higher heat conductivity is interposed between them thereby they are prevented from being separated and the allowance of the machining precision may be higher. CONSTITUTION:When the sleeve 12 having a double axial bore is mounted in a bore 14 of the barrel 11, the interposition 13 of a material having a coefficient of thermal expansion greater than those of the sleeve and the barrel and a higher heat conductivity is interposed between them. For example, when the barrel 11 is made of a carbon steel for mechanical structure, and the sleeve 12 is made of a sintered hard metal, the material for the interposition 13 is preferably copper, aluminum, brass, stainless steel, or the like. It is preferable that the interposition 13 is interposed between the barrel bore 14 and the sleeve outer circumference at a position corresponding to the intermediate between the axes of the double axial bore. |
