Machine tool for a threading process

Patent metadata

Field	Value
Publication number	US-9690283-B2
Application number	US-201314051960-A
Country	US
Kind code	B2
Filing date	Oct 11, 2013
Priority date	Oct 30, 2012
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A machine tool includes a number-of-same-rotation-speed-cutting-passes computing section that decides the number of same rotation speed cutting passes. The number-of-same-rotation-speed-cutting-passes computing section determines the cutting mode of a threading process based on a set machining program etc., and automatically decides an optimal number of same rotation speed cutting passes according to the cutting mode. Thus, even unskilled operators can easily suppress chatter vibrations, and can easily use the machine tool.

First claim

What is claimed is:

1. A machine tool, comprising:
a holding device on which a shaft-shaped workpiece is mounted;
a tool capable of moving in radial and axial directions of the workpiece with respect to the workpiece;
a machining control unit that performs a threading process by repeating a tool pass in which the tool cuts the workpiece in the radial direction, moves in a direction parallel to an axis of the workpiece, and then moves away from the workpiece in the radial direction while the workpiece and the tool are relatively rotated about the axis of the workpiece;
a rotation-speed control unit capable of changing a rotation speed on a tool pass basis; and
a rotation-speed computing section that computes a relative rotation speed between the workpiece and the tool in every tool pass, wherein
the machining control unit is capable of performing the threading process in a plurality of types of cutting modes having different cutting methods of the tool, the machine tool further comprising:
a number-of-same-rotation-speed-cutting-passes computing section that determines a cutting mode and sets the number of same rotation speed cutting passes to “1” if the radial infeed mode or flank infeed is set as the cutting mode, while sets the number of same rotation speed cutting passes to “2” if the alternate flank infeed mode is set as the cutting mode.

2. The machine tool according to claim 1 , further comprising:
a vibration detecting unit that detects vibrations that are generated in a rotation axis direction and an infeed direction;
a vibration-direction determining section that determines a direction in which the vibrations are more likely to be generated, based on the detected vibrations; and
a cutting-mode deciding section that decides the cutting mode from the plurality of types of cutting modes, wherein
the cutting-mode deciding section decides the cutting mode according to the direction in which the vibrations are more likely to be generated, and
the machining control unit performs machining in the cutting mode decided by the cutting-mode deciding section.

3. The machine tool according to claim 1 , wherein
a radial infeed mode, a flank infeed mode, and an alternate flank infeed mode are set as the cutting modes.

4. The machine tool according to claim 2 , wherein
a radial infeed mode, a flank infeed mode, and an alternate flank infeed mode are set as the cutting modes.

Assignees

• Okuma Machinery Works Ltd
• Nat Univ Corp Nagoya Univ
• Nat Univ Corp Nagoya Univ

Inventors

• Nishimura Kohei
• Yoshino Kiyoshi
• Ueno Shigeki
• Shamoto Eiji

Classifications

• G05B2219/45215

  Thread cutting · CPC title

• G05B19/182 Primary

  characterised by the machine tool function, e.g. thread cutting, cam making, tool direction control (G05B19/21 - G05B19/40 take precedence) · CPC title