| 摘要 |
PURPOSE:To make it possible to avoid the slight vibratory phenomenon accompanied by the cutting process with a steel line bar of small diameter and large length for the purpose of improving the tool performance by using ultra- hard material such as cemented carbide alloy or the like with high Young's modulus for at least blade mounting portion of a line bar shaft body. CONSTITUTION:The cemented carbide line bar having a cooland supply hollow hole used for boring the camshaft and crankshaft holes of the cylinder block of an engine is composed of a steel shank 10a and 10b forming both ends of a line bar body 10, and a blade mounting portion 11 which is the middle part of the line bar and compries the shaft body 11a and a lid 11b made of cemented carbide alloy shaft, and faces to be butted are brazed to each other. The hollow hole 10c of the blade mounting portion 11 is provided at the position deviated from the central axis to avoid the decline of rigidity of the line bar body, the clogging of hollow hole with blades and their belongings, and the failure of ability to clamp blades. Thus, the slight vibratory phenomenon accompanied by the cutting process with the steel line bar of small diameter and large length may be avoided to improve the tool performance. |
