Broach

Patent metadata

Field	Value
Publication number	US-11141803-B2
Application number	US-201716087821-A
Country	US
Kind code	B2
Filing date	May 10, 2017
Priority date	May 12, 2016
Publication date	Oct 12, 2021
Grant date	Oct 12, 2021

Abstract

This broach includes a broach body having a shaft shape and a cutting edge section in which cutting edges protrude and are arranged in a longitudinal direction on an outer circumference of the broach body. The cutting edge section includes, in the order from a front side of the broach body, an circumference cutting section in which an outer diameter of each of the cutting edges sequentially increases rearward, and a tooth thickness cutting section in which a thickness of each of the cutting edges sequentially increases from the cutting edges at a rear end of the circumference cutting section toward the rear side. At least a rear end portion of the circumference cutting section is a high-feed cutting section in which the cutting depth per cutting edge is set in a range of 0.15 mm or more and 0.30 mm or less.

First claim

The invention claimed is:

1. A broach comprising:
a broach body having a shaft shape; and
a cutting edge section formed on an outer circumference of the broach body, the cutting edge section having a plurality of cutting edges that protrude from the outer circumference of the broach body and are arranged in a longitudinal direction of the broach body;
wherein the cutting edge section includes, in order from a front side in the longitudinal direction of the broach body:
a circumference cutting section in which an outer diameter of each of the cutting edges of the circumference cutting section sequentially increases toward a rear side of the broach body, and
a tooth thickness cutting section in which a thickness of each of the cutting edges in a circumferential direction of the broach body sequentially increases from the cutting edge section at a rear end of the circumference cutting section toward the rear side of the broach body,
a high-feed cutting section, in which an outer diameter of each of the cutting edges of the high-feed cutting section sequentially increases toward the rear side of the broach body, is disposed in at least a rear end portion of the circumference cutting section, and
a cutting depth per cutting edge in the high-feed cutting section is set in a range of 0.15 mm to 0.30 mm.

2. The broach according to claim 1 ,
wherein a front end portion of the circumference cutting section is a low-feed cutting section where the cutting depth per cutting edge is set in a range that is smaller than that of the high-feed cutting section.

3. The broach according to claim 2 ,
wherein the cutting depth per cutting edge in the low-feed cutting section on the front side of the circumference cutting section is in a range of 0.03 mm to 0.15 mm.

4. The broach according to claim 3 ,
wherein a length of the high-feed cutting section is 40% to 100% of an overall length of the circumference cutting section.

5. The broach according to claim 2 ,
wherein a length of the high-feed cutting section is 40% to 100% of an overall length of the circumference cutting section.

6. The broach according to claim 2 ,
wherein the cutting depth per cutting edge in the low-feed cutting section on the front side of the circumference cutting section is in a range of 0.03 mm to 0.08 mm.

7. The broach according to claim 1 ,
wherein a length of the high-feed cutting section is 40% to 100% of an overall length of the circumference cutting section.

8. The broach according to claim 1 ,
wherein the cutting edges of the cutting edge section form a cutting edge array at intervals along a lead twisted about the axis of the broach body.

9. The broach according to claim 1 ,
wherein the length of the high-feed cutting section is 40% to 80% of the overall length of the circumferential cutting section.

Assignees

• Mitsubishi Materials Corp
• Toyota Motor Hokkaido Inc

Inventors

• Tanaka You
• Kohno Kensuke
• Yamazaki Toru

Classifications

• B23D43/005

  for cutting helical grooves · CPC title

• B23D43/02 Primary

  for cutting by rectilinear movement (B23D43/08 takes precedence) · CPC title

• B23F21/26 Primary

  Broaching tools · CPC title

• B23F1/08

  by broaching; by broach-milling · CPC title