Optical measurement device, optical measurement method, and rotating machine

Patent metadata

Field	Value
Publication number	US-10488182-B2
Application number	US-201716084344-A
Country	US
Kind code	B2
Filing date	Mar 16, 2017
Priority date	Mar 18, 2016
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

There is provided: a pair of slanted fiber groups; a pair of parallel fiber groups; a light source for emitting two slanted light beams from a pair of slanted light-emitting fibers, and emitting two parallel light beams from a pair of parallel light-emitting fibers; a target provided to the outer peripheral surface of a rotor; a pair of light-receiving elements for detecting the intensity of light received by each of a pair of slanted light-receiving fibers; a pair of light-receiving elements for detecting the intensity of light received by each of a pair of parallel light-receiving fibers; and a computation unit for performing a computation that includes an interval affected by thermal elongation on the basis of four waveforms indicating changes in the intensity detected by each of the light-receiving elements.

First claim

The invention claimed is:

1. An optical measurement device comprising:
a pair of first fiber bundles having a pair of first light-emitting fibers, distal ends of which are arranged at a specified interval, and a pair of first light-receiving fibers, distal ends of which are arranged at the specified interval, in a light sensor, the pair of first fiber bundles being arranged to be slanted to respectively form two sides of a triangle in triangulation;
a pair of second fiber bundles having a pair of second light-emitting fibers, distal ends of which are arranged at the specified interval, and a pair of second light-receiving fibers, distal ends of which are arranged at the specified interval, in the light sensor, the pair of second fiber bundles being arranged in parallel with each other;
a light source that outputs light to the pair of first light-emitting fibers and the pair of second light-emitting fibers to emit two slanted light beams from the pair of first light-emitting fibers and emit two parallel light beams from the pair of second light-emitting fibers, wherein
a target of the light emitted from the first light-emitting fibers and the second light-emitting fibers is provided on an outer peripheral surface of a rotary member, reflects the two slanted light beams to the pair of first light-receiving fibers, respectively, and reflects the two parallel light beams to the pair of second light-receiving fibers, respectively;
a pair of first light-receiving elements each of which is connected to the corresponding one of the pair of first light-receiving fibers and detects intensity of the light received by the first light-receiving element:
a pair of second light-receiving elements each of which is connected to the corresponding one of the pair of second light-receiving fibers and detects intensity of the light received by the second light-receiving element; and
a computation unit that performs calculation including the specified interval affected by thermal elongation, using four waveforms indicating changes in the intensity respectively detected by the pair of first light-receiving elements and the pair of second light-receiving elements.

2. The optical measurement device according to claim, wherein
the computation unit
calculates a first time difference from two times of a rising edge and a falling edge of each of the four waveforms and calculates a peripheral speed of the target, using one of the four first time differences or an average of two or more of the four first time differences,
calculates a second time difference from two times at which the target passes by the two parallel light beams using two of the waveforms detected by the pair of second light-receiving elements and calculates the specified interval affected by thermal elongation using the second time difference, and
calculates a third time difference from two times at which the target passes by the two slanted light beams using two of the waveforms detected by the pair of first light-receiving elements and calculates distance from the distal ends of the pair of first light-emitting fibers to the target using the third time difference.

3. The optical measurement device according to claim 2 , wherein
the light source has a first light source that outputs first light to the pair of first light-emitting fibers and a second light source that outputs second light with a wavelength different from a wavelength of the first light to the pair of second light-emitting fibers, and
the optical measurement device further includes
a first filter that is provided between the pair of first light-receiving fibers and the pair of first light-receiving elements and transmits only the first light and
a second filter that is provided between the pair of second light-receiving fibers and the pair of second light-receiving elements and transmits only the second light.

4. A rotating machine comprising the optical measurement device according to claim 3 .

5. The optical measurement device according to claim 1 , wherein
the light source has a first light source that outputs first light to the pair of first light-emitting fibers and a second light source that outputs second light with a wavelength different from a wavelength of the first light to the pair of second light-emitting fibers, and
the optical measurement device further includes
a first filter that is provided between the pair of first light-receiving fibers and the pair of first light-receiving elements and transmits only the first light and
a second filter that is provided between the pair of second light-receiving fibers and the pair of second light-receiving elements and transmits only the second light.

6. A rotating machine comprising the optical measurement device according to claim 1 .

7. A rotating machine comprising the optical measurement device according to claim 2 .

8. A rotating machine comprising the optical measurement device according to claim 5 .

9. An optical measurement method comprising:
arranging, in a light sensor, a pair of first fiber bundles having a pair of first light-emitting fibers, distal ends of which are arranged at a specified interval, and a pair of first light-receiving fibers, distal ends of which are arranged at the specified interval, such that the pair of first fiber bundles are slanted to respectively form two sides of a triangle in triangulation;
arranging, in the light sensor, a pair of second fiber bundles having a pair of second light-emitting fibers, distal ends of which are arranged at the specified interval, and a pair of second light-receiving fibers, distal ends of which are arranged at the specified interval, such that the pair of second fiber bundles are in parallel with each other;
outputting light from a light source to the pair of first light-emitting fibers and the pair of second light-emitting fibers to emit two slanted light beams from the pair of first light-emitting fibers and emit two parallel light beams from the pair of second light-emitting fibers;
reflecting the two slanted light beams to the pair of first light-receiving fibers, respectively, and reflecting the two parallel light beams to the pair of second light-receiving fibers, respectively, using a target provided on an outer peripheral surface of a rotary member;
detecting, using each of a pair of first light-receiving elements connected to the corresponding one of the pair of first light-receiving fibers, intensity of the light received by the first light-receiving element;
detecting, using each of a pair of second light-receiving elements connected to the corresponding one of the pair of second light-receiving fibers, intensity of the light received by the second light-receiving element; and
performing calculation including the specified interval affected by thermal elongation, using four waveforms indicating changes in the intensity respectively detected by the pair of first light-receiving elements and the pair of second light-receiving elements.

10. The optical measurement method according to claim 9 , further comprising:
calculating a first time difference from two times of a rising edge and a falling edge of each of the four waveforms and calculating a peripheral speed of the target using one of the four first time differences or an average of two or more of the four first time differences;
calculating a second time difference from two times at which the target passes by the two parallel light beams using two of the waveforms detected by the pair of second light-receiving elements and calculating the specified interval affected by thermal elongation using the second time difference; and
calculating a third time difference from two times at which the target passes

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Onishi Tomoyuki
• Miyamoto Takahiro
• Kondou Akio

Classifications

• F01D11/14

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• F05D2270/804

  Optical devices · CPC title

• G01B5/0014

  due to temperature (on machine tools B23Q11/0003) · CPC title

• F01D21/003

  Arrangements for testing or measuring (for measuring vibrations G01H) · CPC title

• F05D2220/30

  in turbines · CPC title