To provide a helical broach that prevents over-cutting by a final finishing blade to machine a workpiece with excellent tooth-trace accuracy.
A plurality of cutting edges 5 protruding to the radial outer-peripheral side are lined up in rows at the outer-peripheral part of a shaft-like broach body and arranged into a spiral shape twisted around the axis of the broach body from the tip side of the broach body to the rear-end side and the rows of the cutting edges are arranged circumferentially spaced apart with spacings. The helical broach forms a twisted groove of a predetermined lead on the inner periphery of a machined hole of a workpiece by the plurality of cutting edges. The plurality of cutting edges on the tip side of the broach body in the plurality of cutting edges are made as outer-diameter finishing blades while the plurality of cutting edges on the rear-end side of the broach body are made as tooth-thickness finishing blades. The tooth-thickness finishing blade 7BB is located closest to the rear-end side of the broach body in the plurality of tooth-thickness finishing blades 7B on the rear-end side of the broach body and is formed with a guide blade 13 instead of a cutting blade 9 at the intersecting ridge part between a rake face 5A and a side face facing circumferential one side of the same.
| JPH0611704 | [Name of device] Spline broach |
| JPS5867623 | 【考案の名称】キ-溝ブロ-チ |
KOBAYASHI YOSHIO
KONO KENSUKE
FUJIWARA HIDEYUKI
| JPH02145921U | 1990-12-11 | |||
| JPH0633627U | 1994-05-06 | |||
| JP2007175814A | 2007-07-12 | |||
| JP2000094215A | 2000-04-04 | |||
| JPS62150018U | 1987-09-22 |
Tadashi Takahashi
Hiroshi Masui
Fumihiro Hosokawa