Machine tool and plastic forming method

Patent metadata

Field	Value
Publication number	US-10639753-B2
Application number	US-201816175025-A
Country	US
Kind code	B2
Filing date	Oct 30, 2018
Priority date	Nov 1, 2017
Publication date	May 5, 2020
Grant date	May 5, 2020

Abstract

A machine tool provided with a tool spindle and a work table for supporting a workpiece for plastic forming on a workpiece with a tool attached to the tool spindle. The partially curved tool is has a moving mechanism to move the tool spindle relative to the workpiece, a spindle rotating motor to turn the tool spindle relative to the workpiece, a movement control unit to control the moving mechanism to move the tool along the workpiece while pressing a curved portion on the surface to be machined, and a turn control unit to control the spindle rotating motor to orient a normal line of the curved portion toward the surface of the workpiece at a reference position taken as a reference.

First claim

What is claimed is:

1. A machine tool provided with a tool spindle and a work table for supporting a workpiece for performing a plastic forming on the workpiece with a tool attached to the tool spindle by relatively moving the tool spindle and the work table, wherein:
the tool has a curved portion at least at a part of a side face thereof; and
the machine tool comprises:
a moving mechanism configured to move the tool spindle relative to the workpiece;
a motor configured to turn the tool spindle relative to the workpiece;
a movement control unit configured to control the moving mechanism so that the tool is moved along a surface of the workpiece to be machined while the curved portion is pressed on the surface of the workpiece to be machined; and
a turn control unit configured to control the motor so that a normal line of the curved portion is oriented toward the surface of the workpiece to be machined at a reference position that touches the surface of the workpiece to be machined when machining starts, wherein the tool is rotated to maintain the same side face of the tool in contact with the surface of the workpiece, such that the side face of the tool does not rotate relative to the surface of the workpiece.

2. The machine tool according to claim 1 , wherein the turn control unit is configured to set the reference position at a position differing from a previously set position each time plastic forming is ended a predetermined number of times.

3. The machine tool according to claim 1 , wherein the curved portion is formed in an arc shape.

4. The machine tool according to claim 3 , wherein the turn control unit is configured to set a new reference position at a position shifted by a predetermined angle in the circumferential direction of the tool from a position which has been set as the reference position in a latest plastic forming of the predetermined number of times.

5. The machine tool according to claim 4 , wherein the tool has a cylindrical shape.

6. The machine tool according to claim 5 , further comprising a notification unit configured to notify that the tool should be replaced in a case where an angle between a position set as the new reference position and a position having been set initially as the reference position exceeds 360 degrees.

7. The machine tool according to claim 1 , wherein a surface roughness of the curved portion is 1.0 μM or less.

8. A plastic forming method for performing a plastic forming on a workpiece with a tool attached to a tool spindle by using a machine tool provided with the tool spindle and a work table for supporting the workpiece and by relatively moving the tool spindle and the work table, wherein:
the tool has a curved portion at least at a part of a side face thereof; and
the machine tool is provided with a moving mechanism configured to move the tool spindle relative to the workpiece and a motor configured to turn the tool spindle relative to the workpiece;
the method comprising:
a movement control step of controlling the moving mechanism so that the tool is moved along a surface of the workpiece to be machined while pressing the curved portion on the surface to be machined; and
a turn control step of controlling the motor so that a normal line of the curved portion is oriented toward the surface of the workpiece to be machined at a reference position that touches the surface of the workpiece to be machined when machining starts, wherein the tool is rotated to maintain the same side face of the tool in contact with the surface of the workpiece, such that the side face of the tool does not rotate relative to the surface of the workpiece.

9. The plastic forming method according to claim 8 , wherein the turn control step includes setting the reference position at a position differing from a previously set position each time plastic forming is ended a predetermined number of times.

10. The plastic forming method according to claim 8 , wherein the curved portion is formed in an arc shape.

11. The plastic forming method according to claim 10 , wherein the turn control step includes setting a new reference position at a position shifted by a predetermined angle in the circumferential direction of the tool from a position which has been set as the reference position in a latest plastic forming of the predetermined number of times.

12. The plastic forming method according to claim 11 , wherein the tool has a cylindrical shape.

13. The plastic forming method according to claim 12 , further comprising a notification step of notifying that the tool should be replaced in a case where an angle between a position set as the new reference position and a position having been set initially as the reference position exceeds 360 degrees.

14. The plastic forming method according to claim 8 , wherein a surface roughness of the curved portion is 1.0 μm or less.

Assignees

• Fanuc Corp

Inventors

• Fujii Takaaki

Classifications

• B23Q15/007

  while the tool acts upon the workpiece · CPC title

• G05B19/402

  characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position (G05B19/19 takes precedence) · CPC title

• B23P23/04 Primary

  for both machining and other metal-working operations · CPC title

• B21D31/005

  Incremental shaping or bending, e.g. stepwise moving a shaping tool along the surface of the workpiece (B21D22/14 takes precedence) · CPC title

• B23P9/02 Primary

  Treating or finishing by applying pressure, e.g. knurling (B23P9/04 takes precedence) · CPC title