Inner circumferential length measurement method for circular member

Patent metadata

Field	Value
Publication number	US-10775152-B2
Application number	US-201716085557-A
Country	US
Kind code	B2
Filing date	Feb 16, 2017
Priority date	Mar 16, 2016
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

An inner circumferential length measurement method includes the steps of: disposing a two-dimensional sensor at a predetermined measurement position on an inner side of the circular member placed flat in an unrestrained state on a support so that the two-dimensional sensor faces an inner circumferential surface of the circular member in a non-contact state; rotating the two-dimensional sensor about rotation shaft at a predetermined position on the inner side of the circular member; measuring a separation distance from the two-dimensional sensor to the inner circumferential surface around an entire circumference of the circular member; and calculating an inner circumferential length of the circular member via a calculation unit using the separation distance measured and a distance from the rotation shaft to the two-dimensional sensor in a plan view.

First claim

The invention claimed is:

1. An inner circumferential length measurement method for a circular member, comprising the steps of:
disposing a two-dimensional sensor at a predetermined measurement position on an inner side of the circular member placed flat in an unrestrained state on a support such that the two-dimensional sensor faces an inner circumferential surface of the circular member in a non-contact state;
rotating the two-dimensional sensor about a predetermined position on the inner side of the circular member;
measuring a separation distance from the two-dimensional sensor to the inner circumferential surface around an entire circumference of the circular member; and
calculating an inner circumferential length of the circular member via a calculation unit using the separation distance measured and a distance from the predetermined position to the two-dimensional sensor in a plan view; wherein
the support is raisable from a horizontal state to an upright state;
a surface of the support is provided with projection portions spaced from one another, the projection portions projecting from the surface; and
the circular member is placed flat in an unrestrained state on the support by, in a case where the support is in an upright state, engaging the inner circumferential surface of the circular member with two of the projection portions to place the circular member on the support and putting the support in a horizontal state.

2. The inner circumferential length measurement method for a circular member according to claim 1 , wherein
the projection portions are retractable from the surface of the support; and
the projection portions are retracted below the surface of the support after the circular member is placed flat on the support.

3. The inner circumferential length measurement method for a circular member according to claim 2 , wherein
the two-dimensional sensor is a laser sensor; and
a surface of an adjacent portion of the support adjacent to the circular member placed flat on the support in an unrestrained state is a configured to diffusely reflect laser light radiated by the laser sensor.

4. The inner circumferential length measurement method for a circular member according to claim 1 , wherein
the support comprises an upward projecting protrusion support portion on an upper surface; and
the circular member is placed flat in an unrestrained state on the protrusion-fie support portion.

5. The inner circumferential length measurement method for a circular member according to claim 4 , wherein
the two-dimensional sensor is a laser sensor; and
a surface of an adjacent portion of the support adjacent to the circular member placed flat on the support in an unrestrained state is a configured to diffusely reflect laser light radiated by the laser sensor.

6. The inner circumferential length measurement method for a circular member according to claim 1 , wherein
the two-dimensional sensor is a laser sensor; and
a surface of an adjacent portion of the support adjacent to the circular member placed flat on the support in an unrestrained state is configured to diffusely reflect laser light radiated by the laser sensor.

Assignees

• Yokohama Rubber Co Ltd

Inventors

• Matsumura Kensuke
• Sugiyama Yuichi

Classifications

• G01B11/02 Primary

  for measuring length, width or thickness (G01B11/08 takes precedence) · CPC title

• G01B11/026

  by measuring distance between sensor and object (G01B11/0608 takes precedence) · CPC title

• G01B5/025

  Measuring of circumference; Measuring length of ring-shaped articles (G01B5/0035 takes precedence) · CPC title

• G01B21/02

  for measuring length, width, or thickness (G01B21/10 takes precedence) · CPC title

• G01B11/12 Primary

  internal diameters · CPC title