Quality determination device and quality determination method

Patent metadata

Field	Value
Publication number	US-11460825-B2
Application number	US-202017114250-A
Country	US
Kind code	B2
Filing date	Dec 7, 2020
Priority date	Dec 12, 2019
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

A quality determination device includes an acquisition unit for acquiring a drive current during tapping, from a motor provided in a machine tool that performs tapping, and a determination unit for determining acceptance or rejection of a screw hole formed by the tapping, based on the drive current, an electric power of the motor obtained from the drive current, or a torque of the motor obtained from the drive current.

First claim

What is claimed is:

1. A quality determination device, comprising:
one or more processors that execute computer-executable instructions stored in a memory, wherein the one or more processors execute the computer-executable instructions to cause the quality determination device to:
acquire a drive current during tapping, from a motor provided in a machine tool that forms a screw hole in a workpiece by the tapping; and
determine acceptance or rejection of the screw hole formed by the tapping, based on the drive current, an electric power of the motor obtained from the drive current, or a torque of the motor obtained from the drive current during the formation of the screw hole.

2. The quality determination device according to claim 1 , wherein the one or more processors is configured to determine acceptance or rejection of the screw hole, based on whether or not the drive current, the electric power, or the torque falls within a predetermined range.

3. The quality determination device according to claim 1 , wherein the one or more processors is configured to perform frequency analysis on the drive current, the electric power, or the torque,
wherein the one or more processors is configured to determine acceptance or rejection of the screw hole, based on whether or not a frequency of the drive current, the electric power, or the torque falls within a predetermined frequency range.

4. The quality determination device according to claim 1 , wherein the one or more processors is configured to determine acceptance or rejection of the screw hole by using a prediction model configured to predict acceptance or rejection of the screw hole, based on at least one of the drive current, the electric power, and the torque,
the one or more processors being further configured to:
receive input of correctness or wrongness of prediction made by the prediction model; and
optimize the prediction model based on the input correctness or wrongness of the prediction.

5. The quality determination device according to claim 1 , wherein the memory is configured to cumulatively store identification information for identifying the screw hole and a determination result on the screw hole by the one or more processors in association with each other.

6. A quality determination method performed by executing, by one or more processors, computer-executable instructions stored in a memory, the method comprising:
an acquisition step of acquiring, by the one or more processors, a drive current during tapping, from a motor of a machine tool that forms a screw hole in a workpiece by the tapping; and
a determination step of determining, by the one or more processors, acceptance or rejection of the screw hole formed by the tapping, based on the drive current, an electric power of the motor obtained from the drive current, or a torque of the motor obtained from the drive current during the formation of the screw hole.

7. The quality determination method according to claim 6 , wherein the determination step determines acceptance or rejection of the screw hole, based on whether or not the drive current, the electric power, or the torque falls within a predetermined range.

8. The quality determination method according to claim 6 , further comprising an analyzing step of performing frequency analysis on the drive current, the electric power, or the torque,
wherein the determination step is performed after the analyzing step, and determines acceptance or rejection of the screw hole, based on whether or not a frequency of the drive current, the electric power, or the torque falls within a predetermined frequency range.

9. The quality determination method according to claim 6 , wherein the determination step determines acceptance or rejection of the screw hole by using a prediction model configured to predict acceptance or rejection of the screw hole, based on at least one of the drive current, the electric power, and the torque,
the quality determination method, further comprising:
a teaching step, performed after the determination step, of teaching correctness or wrongness of prediction made by the prediction model; and
an optimization step of optimizing the prediction model based on the taught correctness or wrongness of the prediction.

10. The quality determination method according to claim 6 , further comprising a storing step of cumulatively storing identification information for identifying the screw hole and a determination result on the screw hole at the determination step in association with each other.

Assignees

• Fanuc Corp

Inventors

• Okuaki Kenichi

Classifications

• G05B2219/37441

  Use nc machining program, cad data for measuring, inspection · CPC title

• G05B2219/32179

  Quality control, monitor production tool with multiple sensors · CPC title

• G05B2219/49196

  Screw · CPC title

• B23Q5/28

  Electric drives · CPC title

• G05B2219/32201

  Build statistical model of past normal proces, compare with actual process · CPC title