Cutting method and cut article

Patent metadata

Field	Value
Publication number	US-12311451-B2
Application number	US-202017438056-A
Country	US
Kind code	B2
Filing date	Jan 9, 2020
Priority date	Mar 12, 2019
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

There is provided a cutting method for cutting a workpiece using a cutting tool comprising a die and a punch, including: arranging the workpiece between the die and the punch, and in a state in which a wedge-shaped first cutting part of the die and a wedge-shaped second cutting part of the punch are opposed, pushing the punch relatively to the die side to cut the workpiece; wherein: a front end angle θ 1 of the first cutting part and a front end angle θ 2 of the second cutting part are each 10° or more and 120° or less, and a front end radius R 1 of the first cutting part and a front end radius R 2 of the second cutting part are each 0.5% or more and 35.0% or less of a sheet thickness.

First claim

The invention claimed is:

1. A cutting method for cutting a workpiece using a cutting tool comprising a die and a punch, including:
arranging the workpiece between the die and the punch, and
arranging a wedge-shaped first cutting part of the die opposite a wedge-shaped second cutting part of the punch, and pushing the punch relatively to the die to cut the workpiece;
the method further including:
providing a front end angle (θ 1 ) of the first cutting part and a front end angle (θ 2 ) of the second cutting part, each being 10° or more and 120° or less, and providing a front end radius (R 1 ) of the first cutting part and a front end radius (R 2 ) of the second cutting part, each being 0.5% or more and 35.0% or less of a sheet thickness.

2. The cutting method according to claim 1 , wherein arranging the workpiece includes providing a multi-layer material workpiece formed by coating a surface of a base material with a coating material.

3. The cutting method according to claim 1 , wherein providing the front end angle (θ 1 ) of the first cutting part and the front end angle (θ 2 ) of the second cutting part includes providing the front end angle (θ 1 ) of the first cutting part and the front end angle (θ 2 ) of the second cutting part, each being 30° or more and 90° or less.

4. The cutting method according to claim 1 , wherein providing the front end radius (R 1 ) of the first cutting part and the front end radius (R 2 ) of the second cutting part includes providing the front end radius (R 1 ) of the first cutting part and the front end radius (R 2 ) of the second cutting part, each being 1.5% or more and 10.0% or less of a sheet thickness.

5. The cutting method according to claim 1 , the method further including cutting of the workpiece by a plurality of cutting processes.

6. The cutting method according to claim 5 , wherein:
cutting the workpiece by the plurality of cutting processes includes a first cutting process, and a second cutting process that is performed after the first cutting process; and
performing at least one of the following in the second cutting process:
providing a front end angle (θ 1 ) of the first cutting part in the second cutting process is smaller than a front end angle (θ 1 ) of the first cutting part in the first cutting process, and
providing a front end angle (θ 2 ) of the second cutting part in the second cutting process is smaller than a front end angle (θ 2 ) of the second cutting part in the first cutting process,
and thereafter the workpiece is cut.

7. The cutting method according to claim 5 , wherein:
cutting the workpiece by the plurality of cutting processes includes a first cutting process, and a second cutting process that is performed after the first cutting process; and
performing at least one of the following in the second cutting process:
providing a front end radius (R 1 ) of the first cutting part in the second cutting process is smaller than a front end radius (R 1 ) of the first cutting part in the first cutting process, and
providing a front end radius (R 2 ) of the second cutting part in the second cutting process is smaller than a front end radius (R 2 ) of the second cutting part in the first cutting process;
and thereafter the workpiece is cut.

8. The cutting method according to claim 5 , wherein:
when performing the plurality of cutting processes, providing a front end radius of the first cutting part defined as (R 1 ), a front end radius of the second cutting part defined as (R 2 ), and a sheet thickness of the workpiece defined as (t), and a stroke(S) of the punch in a first cutting process satisfies expression (A) below:
( R 1 +R 2 )≤ S≤{t −( R 1 +R 2 )}  (A).

9. The cutting method according to claim 1 , the method further including:
defining a trimming width of the workpiece is a distance between one end portion of the workpiece and a cutting position of the workpiece, and
satisfying an expression (B) of a trimming width (d) via the expression (B) below,
R≤D≤ 3 t   (B)

R=Min (R 1 , R 2 )
when a front end radius of the first cutting part is defined as (R 1 ), a front end radius of the second cutting part is defined as (R 2 ), and a sheet thickness of the workpiece is defined as (t).

10. The cutting method according to claim 1 , the method further comprising:
providing a wedge-shaped first cutting part of the die and a wedge-shaped second cutting part of the punch having an asymmetrical shape with respect to a normal line at a cutting edge, respectively.

11. The cutting method according to claim 10 , the method further comprising:
dividing a front end angle (θ 1 ) of the first cutting part into two angles (θ 1a ) and (θ 1b ) by a normal line at a cutting edge of the first cutting part,
dividing a front end angle (θ 2 ) of the second cutting part into two angles (θ 2a ) and (θ 2b ) by a normal line at a cutting edge of the second cutting part, and
(θ 1a −θ 1b ) or (θ 1b −θ 1a ) that is an angular difference between the angle (θ 1a ) and the angle (θ 1b ), and (θ 2a −(θ 2b ) or (θ 2b −θ 2a ) that is an angular difference between the angle (θ 2a ) and the angle(θ 2b ) are each 5° or more and 45° or less.

12. The cutting method according to claim 10 , the method further comprising:
providing a front end radius (R 1 ) of the first cutting part is taken as an average value of respective front end radii (R 1a ) and (R 1b ) of the first cutting part that are formed when the front end radius (R 1 ) is divided in two by a normal line at a cutting edge of the first cutting part, and
providing a front end radius (R 2 ) of the second cutting part is taken as an average value of respective front end radii (R 2a ) and (R 2b ) of the second cutting part that are formed when the front end radius (R 2 ) is divided in two by a normal line at a cutting edge of the second cutting part,
the front end radii (R 1 ) and (R 2 ) are 0.5% or more and 35.0% or less of a sheet thickness, respectively.

13. The cutting method according to claim 12 , the method further comprising:
dividing a ratio R 1a /R 1b or R 1b /R 1a between two front end radii formed when the front end radius (R 1 ) of the first cutting part in two, and dividing a ratio R 2a /R 2b or R 2b /R 2a between two front end radii formed when the front end radius (R 2 ) of the second cutting part in two are each 1.1 or more and 100 or less.

14. The cutting method according to claim 1 , comprising:
forming, from the workpiece, an intermediate material having a final shape region, and a surplus region provided along an edge of the final shape region; and
using a cutting tool including a die and a punch in each of which a cutting part is formed in a closed shape in correspondence with the edge of the final shape region, in a state in which a wedge-shaped first cutting part of the die and a wedge-shaped second cutting part of the punch are opposed, pushing the punch relatively to the die side to cut the intermediate material.

Assignees

• Nippon Steel Corp

Inventors

• Yasutomi Takashi
• Kobayashi Akinobu

Classifications

• B23D35/001

  cutting members · CPC title

• B21D28/34

  Perforating tools; Die holders · CPC title

• B21D28/26

  in sheets or flat parts · CPC title

• B21D28/14 Primary

  Dies (ejecting or stripping-off devices arranged in punching machines or tools B21D45/00) · CPC title

• B23D35/00

  Tools for shearing machines or shearing devices; Holders or chucks for shearing tools · CPC title