Method and device displaying material fatigue of machine

Patent metadata

Field	Value
Publication number	US-10620082-B2
Application number	US-201415108078-A
Country	US
Kind code	B2
Filing date	Mar 3, 2014
Priority date	Mar 3, 2014
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

To associate condition information, such as (a) a location in a movement section at which fatigue occurred, (b) a type of work or operation during which fatigue occurred, and (c) a type of natural phenomenon experienced when fatigue occurred, a device for displaying the material fatigue of a machine is configured to observe stress variation in a time series using a sensor correlated with the stress variation or stress of a machine. Stress variation in a single cycle and the time when the stress variation occurred are detected, and the stress variation value and time of occurrence are output and displayed.

First claim

The invention claimed is:

1. A device for displaying material fatigue of a target machine comprising:
a fatigue damage detection sensor receiving an input signal associated with stress from the target machine and providing, as a measured stress waveform, an output signal representing pole values indicating maximum and minimum measured values of said stress and including a time stamp;
a time information occurrence unit adding said time stamp at a time of sampling data in the fatigue damage detection sensor;
a calculation unit receiving the output signal representing the pole values indicating the maximum and minimum measured values of said stress and including the time stamp from the fatigue damage detection sensor, calculating the measured stress waveform by detecting a variation in stress amplitude and an occurrence time of the variation in stress amplitude, converting the measured stress waveform into peak stress values, extracting a stress amplitude from the peak stress values, identifying as a closed stress a stress variation having equal starting and ending points, obtaining a product of the variation in stress amplitude and the occurrence time of the variation in stress amplitude, and outputting display information including the product obtained; and
a display unit to receive the display information from the calculation unit and display, as the material fatigue of the target machine, a time series variation of stress obtained from the product of the variation in stress amplitude and the occurrence time of the variation in stress amplitude.

2. The device for displaying material fatigue of a machine according to claim 1 , wherein the variation in stress amplitude is repeated variation of a single cycle, and the calculation unit converts the variation in stress amplitude into fatigue damage of the single cycle and outputs the fatigue damage of the single cycle.

3. The device for displaying material fatigue of a machine according to claim 1 , wherein output from the calculation unit is supplied to a device that associates a state of a machine in a time series manner with variation in stress amplitude, fatigue damage of a single cycle, or time series fatigue damage velocity based on time information, and outputs the variation in stress amplitude, the fatigue damage of the single cycle, or the time series fatigue damage velocity, associated with state variation information of the machine, to the display unit.

4. The device for displaying material fatigue of a machine according to claim 1 , wherein the fatigue damage detection sensor directly measures stress applied to the target machine.

5. The device for displaying material fatigue of a machine according to claim 1 , wherein the fatigue damage sensor measures a physical amount correlated with a stress value.

6. The device for displaying material fatigue of a machine according to claim 5 , wherein the fatigue damage sensor is applied to an acceleration sensor.

7. The device for displaying material fatigue of a machine according to claim 5 , wherein the fatigue damage sensor is applied to a strain sensor.

8. The device for displaying material fatigue of a machine according to claim 1 , wherein the display unit performs drawing processing by using stress amplitude value, starting time, and ending time data output from the calculation unit.

9. A device for displaying material fatigue of a target machine comprising:
a fatigue damage detection sensor receiving an input signal associated with stress from the target machine and providing, as a measured stress waveform, an output signal representing pole values indicating maximum and minimum measured values of said stress and including a time stamp;
a time information occurrence unit adding said time stamp at a time of sampling data in the fatigue damage detection sensor;
a calculation unit receiving the output signal representing the pole values indicating maximum and minimum measured values of said stress and including the time stamp from the fatigue damage detection sensor, calculating the measured stress waveform by detecting a variation in stress amplitude, a starting time of the variation in stress amplitude, and an ending time of the variation in stress amplitude, converting the measured stress waveform into peak stress values, extracting a stress amplitude from the peak stress values, identifying as a closed stress a stress variation having equal starting and ending points, obtaining a product of the variation in stress amplitude and a difference between the starting time of the variation in stress amplitude and the ending time of the variation in stress amplitude, and outputting display information including the product obtained; and
a display unit to receive the display information from the calculation unit and display, as the material fatigue of the target machine, a time series variation of stress obtained from the product of the variation in stress amplitude and the difference between the starting time of the variation in stress amplitude and the ending time of the variation in stress amplitude.

10. The device for displaying material fatigue of a machine according to claim 9 , wherein the calculation unit obtains single cycle fatigue damage by dividing fatigue damage of a single cycle by a time difference between the starting time and the ending time of variation in stress amplitude, obtains time series fatigue damage velocity added on a time axis with fatigue damage velocity obtained from another single cycle fatigue damage, and outputs to the display unit the time series fatigue damage velocity together with the time axis.

11. The device for displaying the material fatigue of a machine according to claim 10 , wherein the calculation unit represents the amount of the fatigue damage accumulated until the current time by integrating the fatigue damage of the single cycle.

12. The device for displaying material fatigue of a machine according to claim 9 , wherein the fatigue damage detection sensor directly measures stress applied to the target machine.

13. The device for displaying material fatigue of a machine according to claim 9 , wherein the fatigue damage sensor measures a physical amount correlated with a stress value.

14. The device for displaying material fatigue of a machine according to claim 13 , wherein the fatigue damage sensor is applied to an acceleration sensor.

15. The device for displaying material fatigue of a machine according to claim 13 , wherein the fatigue damage sensor is applied to a strain sensor.

16. The device for displaying material fatigue of a machine according to claim 9 , wherein the display unit performs drawing processing by using stress amplitude value, starting time, and ending time data output from the calculation unit.

17. A device for displaying material fatigue of a target machine comprising:
a fatigue damage detection sensor receiving an input signal associated with stress from the target machine and providing, as a measured stress waveform, an output signal representing pole values indicating maximum and minimum measured values of said stress and including a time stamp;
a time information occurrence unit adding said time stamp at a time of sampling data in the fatigue damage detection sensor;
a calculation unit receiving the output signal representing the pole values indicating the maximum and minimum measured values of said stress and including the time stamp from the fatigue damage detection sensor, calculating the measured stress waveform by detecting a variation in stress amplitude, a starting time of the variation in stress amplitude

Assignees

• Hitachi Ltd

Inventors

• Unuma Munetoshi
• Yuda Shinya
• Saeki Takashi
• Suzuki Hideaki

Classifications

• G01M5/0033 Primary

  by determining damage, crack or wear · CPC title

• G01M17/007

  Wheeled or endless-tracked vehicles (G01M17/08 takes precedence) · CPC title

• G01M13/00

  Testing of machine parts · CPC title