| 摘要 |
<p>PURPOSE:To obtain easily and efficiently bat on which a grip is consecutively provided as one body in the end part of a grip part, by forming a metallic pipe by a rotary swaging method. CONSTITUTION:A pipe 1 of a light alloy, which has the thickness corresponding to the thickness of a bat to be obtained is set to a rotary swaging machine, and a pair of upper and lower rotary dies 2, 3 are moved from its important part toward the root part and are hit strongly. In this case, the diameter of the important part of the pipe 1 is reduced 1a gradually, and the outside diameter of the reduced diameter part 1a is nearly equalized to the diameter of a grip 6. Subsequently, the interval of the dies 2, 3 is reduced, or dies 4, 5 whose interval is narrow are used, and the dies are hit so that its tip is bitten into the reduced diameter part 1a, are moved in the direction of the root part of the pipe 1, and are stopped immediately before the root part. In this case, a shape of die tip part sides 4a, 5a of the pipe root part is equal to a shape of an inclined face of the grip 6 to be obtained, and the interval of both the dies is equal to the diameter of a grip part 1b of the final product.</p> |
