# US 12,769,275 B2 · Positional relationship measurement method and machining apparatus

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- Number: US 12,769,275 B2
- Document ID: US12769275B2
- Status: Granted
- Kind: B2
- Application number: 18/156,164
- Filed: 2023-01-18
- Published: 2023-05-18
- Granted: 2026-10-20
- Earliest claimed: 2021-03-19
- Assignees: National University Corporation Tokai National Higher Education and Research System
- Applicants: National University Corporation Tokai National Higher Education and Research System
- Inventors: Eiji Shamoto
- Web page: https://patentgrep.com/patent/US12769275B2

## CPC

- G05B 19/182: {characterised by the machine tool function, e.g. thread cutting, cam making, tool direction control (G05B19/21 - G05B19/40 take precedence)}
- G05B 2219/37087: Cutting forces
- G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G)

## Abstract

A control device moves a cutting tool relative to a workpiece to bring the workpiece and the cutting tool into contact with each other, and acquires a coordinate value of a reference point when the workpiece and the cutting tool come into contact with each other. The control device derives an error between the coordinate value thus acquired and a design coordinate value of the reference point at a position where the workpiece and the cutting tool come into contact with each other, and outputs information on the error.

## Claims

### Claim 1

A positional relationship measurement method for measuring a relative positional relationship between a workpiece and a tool, the method comprising:
moving the tool relative to the workpiece to bring the workpiece and the tool into contact with each other;
acquiring a coordinate value of a reference point when the workpiece and the tool come into contact with each other;
deriving an error between the coordinate value acquired and a design coordinate value of the reference point at a position where the workpiece and the tool come into contact with each other; and
outputting information on the error, wherein
in the moving, the workpiece and the tool are brought into contact with each other at the plurality of positions spaced apart from each other in one translation direction that is a radial direction centered on a rotation axis,
in the acquiring the coordinate value, a plurality of coordinate values of the reference point when the workpiece and the tool come into contact with each other at the plurality of positions are acquired,
in the deriving the error, a plurality of the errors at the plurality of contact positions are derived, and
in the outputting, information on the error in the translation direction and information on the error in a rotation direction about the rotation axis are output.

### Claim 2

A positional relationship measurement method for measuring a relative positional relationship between a workpiece and a tool, the method comprising:
moving the tool relative to the workpiece to bring the workpiece and the tool into contact with each other;
acquiring a coordinate value of a reference point when the workpiece and the tool come into contact with each other;
deriving an error between the coordinate value acquired and a design coordinate value of the reference point at a position where the workpiece and the tool come into contact with each other; and
outputting information on the error, wherein
in the moving, the tool is relatively moved in two translation directions to come into contact with the workpiece at the plurality of positions,
in the acquiring the coordinate value, a plurality of coordinate values of the reference point when the workpiece and the tool come into contact with each other at the plurality of positions are acquired,
in the deriving the error, a plurality of the errors at the plurality of contact positions are derived, and
in the outputting, information on the errors in the two translation directions and information on the error in one rotation direction are output.