Inspecting method of elastic body, inspecting apparatus thereof, and dimension predicting program thereof

• US 20050284224A1
• Filed: 04/27/2005
• Published: 12/29/2005
• Est. Priority Date: 04/27/2004
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Yamada, Tomohiro, Hatta, Tetsuya, Komazawa, Masato, Nehagi, Takatoshi
• Granted Patent: US 7,424,827 B2
• Time in Patent Office: Days
• US Class Current: 73/579
• CPC Class Codes: G01N 2291/014 Resonance or resonant frequency
• CPC Class Codes: G01N 29/045 by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks measuring resonant frequency G01H13/00; measuring strength properties by application of mechanical stress G01N3/00
• CPC Class Codes: G01N 29/12 by measuring frequency or resonance of acoustic waves measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00
• CPC Class Codes: G01N 29/42 by frequency filtering or by tuning to resonant frequency
• CPC Class Codes: H01H 2057/006 Micromechanical piezoelectric relay
• CPC Class Codes: H10N 30/2047 Membrane type

Abstract

In an inspecting method of a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes, the frequency response characteristics is picked up when a vibration is given to the piezoelectric/electrostrictive actuator, and the amount of displacement of the piezoelectric/electrostrictive actuator is predicted by the frequency response characteristics. The piezoelectric/electrostrictive actuator is precisely inspected without dissolution and destruction and without actual driving as a product.

Claims

1. An inspecting method of an elastic body in a structure having two or more of elastic bodies which comprises

picking up a frequency response characteristics of an elastic body when a vibration is given to a structure having two or more of elastic bodies, and predicting a dimension of said two or more of elastic bodies based on said frequency response characteristics.

2. An inspecting method of an elastic body according to claim 1, wherein said frequency response characteristics is one of the characteristics selected from the group consisting of a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies degrees.

3. An inspecting method of an elastic body according to claim 1, wherein said frequency response characteristics is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

4. An inspecting method of a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes which comprises

picking up frequency response characteristics when a vibration is given to a piezoelectric/electrostrictive actuator, and

predicting an amount of displacement of the piezoelectric/electrostrictive actuator based on said frequency response characteristics.

5. An inspecting method of a piezoelectric/electrostrictive actuator according to claim 4, wherein said frequency response characteristics is a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees.

6. An inspecting method of a piezoelectric/electrostrictive actuator according to claim 4, wherein said frequency response characteristics is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of other degrees and at least one of resonant frequencies of other degrees.

7. An inspecting method of a piezoelectric/electrostrictive sensor having a piezoelectric/electrostrictive element and two or more electrodes which comprises

picking up a frequency response characteristics when a vibration is given to a piezoelectric/electrostrictive actuator, and

predicting a detecting sensitivity of said piezoelectric/electrostrictive sensor based on said frequency response characteristics.

8. An inspecting method of a piezoelectric/electrostrictive sensor according to claim 7, wherein said frequency response characteristics is a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees.

9. An inspecting method of a piezoelectric/electrostrictive sensor according to claim 7, wherein said frequency response characteristics is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

10. An inspecting apparatus of an elastic body in a structure having two or more of elastic bodies which comprises

means for picking up a frequency response characteristics when a vibration is given to a structure having two or more of elastic bodies, and

means for predicting an dimension of said elastic body based on said frequency response characteristics.

11. An inspecting apparatus of an elastic body according to claim 10, wherein said frequency response characteristics is a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees.

12. An inspecting apparatus of an elastic body according to claim 10, wherein said frequency response characteristics is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and resonant frequencies of other degrees.

13. An inspecting apparatus of a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes which comprises

means for picking up a frequency response characteristics when a vibration is given to said piezoelectric/electrostrictive actuator, and

means for predicting an amount of displacement of said piezoelectric/electrostrictive actuator based on said frequency response characteristics.

14. An inspecting apparatus of a piezoelectric/electrostrictive actuator according to claim 13, wherein said frequency response characteristics is a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees.

15. An inspecting apparatus of a piezoelectric/electrostrictive actuator according to claim 13, wherein said frequency response characteristics is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

16. An inspecting apparatus of a piezoelectric/electrostrictive sensor having a piezoelectric/electrostrictive element and two or more electrodes which comprises

means for picking up a frequency response characteristics upon vibrating a piezoelectric/electrostrictive sensor having a piezoelectric/electrostrictive element and two or more electrodes, and

means for predicting a detecting sensitivity of said piezoelectric/electrostrictive sensor based on said frequency response characteristics.

17. An inspecting apparatus of a piezoelectric/electrostrictive sensor according to claim 16, wherein said frequency response characteristics is a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees.

18. An inspecting apparatus of a piezoelectric/electrostrictive sensor according to claim 16, wherein said frequency response characteristics is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

19. A dimension predicting program of an elastic body in a structure having two or more of elastic bodies, for enabling a computer to function as:

means for inputting a measurement value of a frequency response characteristics of a structure having two or more of elastic bodies whose predicted dimension is calculated;

means for obtaining a predicted dimension of said elastic body of said structure based on a calculating formula of the predicted dimension; and

means for outputting thus obtained predicted dimension of said elastic body of said structure.

20. A prediction program of an amount of displacement of a piezoelectric/electrostrictive actuator for predicting an amount of displacement of said piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes, for enabling a computer to function as:

means for inputting a frequency response characteristics of said piezoelectric/electrostrictive actuator whose predicted amount of displacement is calculated;

means for obtaining a predicted amount of displacement of said piezoelectric/electrostrictive actuator based on a calculating formula of the predicted amount of displacement; and

means for outputting thus obtained predicted amount of displacement of said piezoelectric/electrostrictive actuator.

21. A prediction program of a detecting sensitivity of a piezoelectric/electrostrictive sensor, for enabling a computer to function as:

means for inputting a frequency response characteristics of a piezoelectric/electrostrictive sensor whose predicted detecting sensitivity is to be calculated;

means for obtaining a predicted detecting sensitivity of said piezoelectric/electrostrictive sensor based on a calculating formula of said detecting sensitivity; and

means for outputting thus obtained predicted detecting sensitivity of said piezoelectric/electrostrictive sensor.