发明名称 DRILL
摘要 A guide portion prevents the drilling hole from curving due to a skipping rope phenomenon, and also prevents the inner wall face of the drilling hole from being damaged, so that its surface roughness can be improved. Chip evacuating flutes 4 are formed in the periphery of a drill body 1 which has a stick shape and is rotatable on its axis O, from its front flank 3 toward the rear side. Cutting edges 2A are formed along ridge lines where the front flanks 3 intersect with wall faces 4A which are in the chip evacuating flutes 4 and face in a drill rotational direction T. A cutting edge section 2, where the cutting edges 2A are formed, is provided in the front side of the drill body 1. A cutting edge section 2 has an external diameter which is smaller toward the rear side in the axis O direction than the external diameter D at the cutting edges 2A. A guide portion 6 has a maximum external diameter part 6A at the front periphery side, and is provided to the rear side of the cutting edge section 2. An external diameter at the maximum external diameter part 6A is larger than the external diameter at the rear of the cutting edge section 2, and is smaller than or equal to the external diameter D at the cutting edges 2A. The maximum external diameter part 6A of the guide portion 6 shows a smooth convex curve shape in a rotatory figure obtained by rotating it on the axis O.
申请公布号 US2011211924(A1) 申请公布日期 2011.09.01
申请号 US20090998020 申请日期 2009.09.04
申请人 MITSUBISHI MATERIALS CORPORATION 发明人 YANAGIDA KAZUYA;NARUKE KOICHIRO
分类号 B23B51/00 主分类号 B23B51/00
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