TWI819602B - Ultrasonic measurement method and ultrasonic measurement device - Google Patents

Abstract

An object of the present invention is to provide an ultrasonic measurement method that can evaluate the state of an interface even if a static interface cannot obtain a reference ultrasonic measurement result. The ultrasonic measurement method of the present invention evaluates the interface state of a structure with an N-1 static interface formed by N layers. It has the following steps: transmitting and receiving ultrasonic waves from the outer surface of the structure, based on the obtained waveform data, Extract the echo intensity from each interface of N-1 and the echo intensity from the bottom surface of the N layer; establish N equations showing the relationship between the echo intensity from each interface, the echo intensity from the bottom surface and the interface status index, and combine the lower side The echo intensity is divided by the echo intensity on the upper side, the common terms are eliminated, and N-1 equations showing the relationship between echo intensity and interface status indicators are solved, the interface status indicators are displayed with the echo intensity, and the interface status indicators of each interface are calculated; and based on The calculated interface status indicators of each interface are used to evaluate the interface status of each interface.

Description

Ultrasonic measurement method and ultrasonic measurement device

The present invention relates to an ultrasonic measurement method and an ultrasonic measurement device that use an ultrasonic sensor to evaluate interface status.

Friction or wear plays an important role in the mechanical properties of industrial products and is deeply related to the state of the contact interface. The microscopic phenomena produced at the contact interface are found on the macroscopic level as mechanical properties. Therefore, the demand for directly observing the interface status is high.

However, in general, the components involved in friction or wear are opaque, making it difficult to directly observe the interface state.

Therefore, the interface status is assessed indirectly with non-destructive measurements. As background technology in this technical field, there is Japanese Patent Application Laid-Open No. 2010-60412 (Patent Document 1).

Patent Document 1 describes a contact area ratio evaluation method in which the intensity of the first reflected wave reflected from the front end of the first electrode wafer is measured in a state where the first electrode wafer is separated from the workpiece W1, and the contact area ratio is measured relative to the first electrode wafer. The intensity of the second reflected wave reflected from the front end of the first electrode chip is measured while the workpiece W1 is in contact. Based on the respective intensities of the first reflected wave and the second reflected wave, Calculate the intensity ratio (reflected wave rate) and the proportion of the ultrasonic wave incident on the workpiece W1 (incident wave rate). From the predetermined correlation between the contact area of the site where ultrasonic waves can be incident and the incident wave rate, determine the location. The ratio of the total area to the contact area of the part in contact with the workpiece W1 (contact area ratio) (refer to the abstract of Patent Document 1).

[Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2010-60412

In a dynamic interface with repeated contact and non-contact, it is only necessary to obtain the ultrasonic measurement results as a reference when the interface is non-contact, and evaluate the interface at the time of contact to be evaluated.

However, since there is a static interface in the fitting part of the turbine, pump, etc., ultrasonic measurement results that serve as a reference cannot be obtained. Furthermore, when the ultrasonic wave is propagated from the outer surface of the industrial product to the inside of the industrial product and the interface state is evaluated, the contact state between the ultrasonic sensor and the outer surface of the industrial product is coated or uneven. etc., it is impossible to obtain a stable echo intensity that serves as a benchmark.

Patent Document 1 describes a contact area ratio evaluation method that uses an ultrasonic sensor to evaluate the interface state of a workpiece. However, the contact area ratio evaluation method described in Patent Document 1 is to obtain in advance the correlation between the contact area of the part where ultrasonic waves can be incident and the incident wave rate, and is not necessarily based on the method. Evaluating the interface state in a static interface such as a fitting part of a turbine or pump, etc., where the ultrasonic measurement results that serve as a reference cannot be obtained.

Therefore, the present invention provides an ultrasonic measurement method and an ultrasonic measurement device that can evaluate the interface state even if a static interface cannot obtain a reference ultrasonic measurement result.

In order to solve the above problems, the ultrasonic measurement method of the present invention is characterized in that it is an ultrasonic measurement method for evaluating the interface state of a structure having an N-1 static interface formed by N layers, and has the following steps: self-construction The external surface of the object sends and receives ultrasonic waves. Based on the obtained waveform data, the echo intensity from each interface of N-1 and the echo intensity from the bottom surface of the N layer are captured; the echo intensity from each interface and the echo intensity from the bottom surface are divided Using the diffusion attenuation term that depends on the propagation distance of the ultrasonic wave, establish N equations showing the relationship between the calculated echo intensity and the interface state index that is proportional to the real contact area. Divide the calculated echo intensity on the lower side by dividing the above Divide the calculated echo intensity, eliminate common terms, solve the N-1 equations showing the relationship between echo intensity and interface status indicators, use the echo intensity to display the interface status indicators, calculate the interface status indicators of each interface; and based on the calculation, The interface status indicator of each interface is used to evaluate the interface status of each interface.

Furthermore, the ultrasonic measuring device of the present invention is characterized in that it is an ultrasonic measuring device that evaluates the interface state of a structure having an N-1 static interface formed by N layers, and is based on transmitting and receiving signals from the outer surface of the structure. The waveform data obtained by the ultrasonic ultrasonic sensor captures the echo intensity from each interface of N-1 and the echo intensity from the bottom surface of the N layer; the echo from each interface is The intensity and the echo intensity from the bottom surface are divided by the diffusion attenuation term that depends on the propagation distance of the ultrasonic wave. N equations are established showing the relationship between the calculated echo intensity and the interface state index that is proportional to the real contact area. The lower side Divide the echo intensity calculated by dividing the echo intensity calculated by the above division, eliminate the common terms, solve the N-1 equations showing the relationship between the echo intensity and the interface status index, use the echo intensity to display the interface status index, and calculate the value of each interface Interface status indicator; and has a control/processing unit that evaluates the interface status of each interface based on the calculated interface status indicator of each interface.

According to the present invention, it is possible to provide an ultrasonic measurement method and an ultrasonic measurement device that can evaluate the state of an interface even if a static interface cannot obtain a reference ultrasonic measurement result.

In addition, problems, structures, and effects other than those mentioned above will become clear from the description of the following examples.

1: Measurement Department

2: Ultrasonic sensor

3: Structure

4: Sending and receiving department

5:Control/Processing Department

6:Display part

7: Input device

8:Scanner

51:Memory device

52: Processing device

53: Transceiver control device

54: Scanner control device

d _N : close sound field limit distance

E ₁ : echo intensity

E ₂ : echo intensity

E ₃ : echo intensity

S001~S009: steps

S _r1 : shape factor

S _r2 : shape factor

S _r3 : shape factor

X ₁ : reflectivity

X ₂ : reflectivity

z ₁ : Thickness

z ₂ : Thickness

z ₃ :Thickness

Figure 1 is an explanatory diagram illustrating the structure of the fitting portion between the shaft and the disk according to this embodiment. (a) shows the case where the shaft is hollow, and (b) shows the case where the shaft is solid.

FIG. 2 is an explanatory diagram schematically illustrating the propagation of ultrasonic waves in the fitting portion of the shaft and the disk according to this embodiment.

Figure 3 is an explanatory diagram illustrating the propagation of ultrasonic waves at the fitting portion of the shaft and disk according to this embodiment. (a) shows the case where the shaft is hollow, and (b) shows the case where the shaft is solid.

FIG. 4 is a schematic illustration of ultrasonic measurement in the case of three layers described in this embodiment. Figure.

FIG. 5 is an explanatory diagram illustrating the relationship between the close range sound field limit distance d _N (distance z) and the propagation attenuation term d(z) of the ultrasonic sensor described in this embodiment.

FIG. 6 is an explanatory diagram illustrating the acquired waveform in the case of three layers described in this embodiment.

FIG. 7 is an explanatory diagram illustrating the measurement and evaluation flow of the ultrasonic measurement method described in this embodiment.

FIG. 8 is an explanatory diagram illustrating the relationship between the interface state index and the mechanical characteristics described in this embodiment.

FIG. 9 is an explanatory diagram illustrating the relationship between time and interface status indicators described in this embodiment.

FIG. 10 is an explanatory diagram illustrating the ultrasonic measuring device described in this embodiment.

Hereinafter, embodiments of the present invention will be described using drawings. In addition, in each drawing, the same symbols are attached to substantially the same or similar components, and when repeated description is given, the repeated description may be omitted.

[Example]

First, the structure of the fitting portion between the shaft and the disk described in this embodiment will be described.

Fig. 1 is an explanatory diagram illustrating the structure of the fitting portion of the shaft and the disk according to this embodiment. (a) shows a case where the shaft is hollow, and (b) shows a case where the shaft is solid, such as a turbine. Or a static interface (measurement object) like a fitting part of a pump, etc.

Both (a) and (b) are structures (industrial products) in which the shaft and the disk are fitted and integrated, for example, as a rotating body to transmit power through the fitting surface (interface).

At this time, due to the influence of the surface roughness of the outer surface of the shaft or the inner surface of the disk, the interface may engage with each other without any gap, or may create a space for air, oil, or water to exist.

In this embodiment, the interface state of the shaft and disk is evaluated by non-destructive measurement using ultrasonic waves.

In addition, regardless of whether the materials of the shaft and the disc are of the same type or different types, in the case of different materials, reflection due to the difference in acoustic impedance between the materials will occur. Therefore, based on the known material density and sound speed (sound speed) impedance) to be corrected. In addition, in this embodiment, since this correction is relatively easy, the case of the same material is demonstrated.

Next, ultrasonic wave propagation in the fitting portion of the shaft and disk described in this embodiment will be schematically explained.

FIG. 2 is an explanatory diagram schematically illustrating the propagation of ultrasonic waves in the fitting portion of the shaft and the disk according to this embodiment.

As shown in Figure 2, if there is no gap in the meshing part, the ultrasonic wave will pass through the interface between the shaft and the disc's fitting part. On the other hand, as shown in Figure 2, a space is generated at the interface between the shaft and the disk. If non-linear phenomena are not taken into account at this location, the ultrasonic wave is almost completely reflected when air is present, and more than 90% is reflected when liquid is present, making it almost impermeable.

That is, in the fitting part, the larger the area of the gap-free meshing part (the complete meshing part), which is also called the true contact surface, the easier it is for ultrasonic waves to pass through. The smaller the area of the meshing part, the harder it is for ultrasonic waves to pass through. through.

Next, ultrasonic wave propagation in the fitting portion of the shaft and disk described in this embodiment will be described.

Figure 3 is an explanatory diagram illustrating the propagation of ultrasonic waves at the fitting portion of the shaft and disk according to this embodiment. (a) shows the case where the shaft is hollow, and (b) shows the case where the shaft is solid.

It is impossible to obtain a static interface that serves as a reference for ultrasonic measurement results, and evaluate the interface status through ultrasonic measurement.

As shown in Figure 3(a), even if the two media of the shaft and the disk are hollow, the ultrasonic wave will pass through the two layers (two-layer system) of the shaft and the disk, and the interface 1 (embedded) between the shaft and the disk. joint) spread. On the other hand, as shown in Figure 3(b), even if the two media of the shaft and the disk are solid, the ultrasonic wave will pass through the three layers of the shaft and the disk (three-layer system), and the two layers of the shaft and the disk. Interface 1 (fitting part) and interface 2 (fitting part) propagate.

In addition, in the case of a three-medium fitting portion, the ultrasonic wave propagates through the third layer and the second interface when the shaft is hollow, and when the shaft is solid, it propagates through the fifth layer and the fourth interface. Therefore, it is important to perform interface state assessment using ultrasonic measurements assuming a multi-layer system.

Here, it is considered that in ultrasonic measurement, ultrasonic waves are incident on the fitting portion of N layers (N is a natural number of 2 or more) from the outer surface of the first layer through the ultrasonic sensor, and the result is obtained to the Nth layer The distance from the bottom surface is equivalent to the received waveform (obtained waveform), and the interface state of N-1 directly below the ultrasonic sensor can be simply evaluated.

Let the echo intensity of the reflected wave from the interface between the first layer and the second layer be E ₁ , and set the echo intensity of the reflected wave from the interface between the second layer and the third layer to E ₂ , and set it to 1≦k≦ N, define and formalize the echo intensity of the reflected wave from the interface of the k-th layer and the k+1-th layer as E _k , and define and formalize the echo intensity of the reflected wave from the bottom surface of the N-th layer as E _N .

E ₁ , E ₂ , E _k , and E _N can be expressed as Formula 1-1, Formula 1-2, Formula 1-3, and Formula 1-4 respectively.

[Number 1]E ₁ =I‧C ² ‧U‧X ₁ ‧d(z ₁ )‧S _r1 = f (X ₁ ). ． ． Formula 1-1

[Number 2]E ₂ =I‧C ² ‧U‧(1-X ₁ ) ² ‧X ₂ ‧d(z ₁ +z ₂ )‧S _r2 = f (X ₁ , X ₂ )...Equation 1-2

‧‧‧

[Number 3]

‧‧‧

Here, the transmitted wave intensity is set to I, the contact factor is set to C, the device factor is set to U, the reflectance of the interface between the k-th layer and the k+1-th layer is set to X _k , and the transmittance is set to Set as 1-X _k , set the thickness of the k-th layer as z _k , set the effect of propagation distance on diffusion attenuation (diffusion attenuation term) as d(z), and set the shape factor of the reflectivity of the interface or bottom surface as _Srk .

In addition, various losses such as scattering loss and viscosity loss that occur when ultrasonic waves pass through the interface, or the scattering attenuation that occurs when ultrasonic waves propagate through materials, are ignored.

In addition, d(z) can be selected at a frequency that has no scattering attenuation from the material, and can be logically obtained at a distance sufficiently far from the close distance of the sound field limit of the ultrasonic sensor used.

In addition, when the shape factor S _r resulting from the shape of each layer is considered to be equivalent to a plane when compared with the opening circle of the ultrasonic sensor, S _r =1. Furthermore, even when there is an influence of curvature, since the fitting part has a simple shape such as a cylinder or a sphere, it can be calculated logically.

Furthermore, if the common term K (K=IC ² U) is divided by the mutual expression, that is, if E _k /E _k+1 is calculated, it can be eliminated.

That is, if the echo intensities of E ₁ to E _N can be obtained, it will be the same as the number of N-1 unknowns, and it will become an equation about N-1 E _k /E _k+1 . Therefore, X _k or 1-X _k closely related to each interface state can be obtained.

Of course, since X _k is defined as reflectivity and 1-X _k is defined as transmittance, the calculated value becomes a value with the true contact area ratio (real contact area ratio) as the main factor. In addition, it includes the influence caused by air or liquid filling the space of the interface.

In addition, since the above-mentioned various losses are relatively small, they are ignored, and it is a prerequisite to select a frequency that has no scattering attenuation.

Hereinafter, 1-X _k , which is directly proportional to the real contact area (real contact area), is called the interface state index. In addition, the interface status indicator becomes a value close to the true contact area ratio of the interface directly below the installation position of the ultrasonic sensor. Therefore, it is closely related to external forces such as torque and tension, and can be used for quality management or monitoring of the fitting part.

Next, ultrasonic measurement in the case of three layers described in this embodiment will be schematically explained.

FIG. 4 is a schematic illustration of ultrasonic measurement in the case of three layers described in this embodiment. Figure.

Here, specifically as shown in FIG. 4 , a situation is shown in which the ultrasonic sensor is brought into contact with a structure having a measurement target and the interface state of three parallel flat plates is measured.

In addition, since there are three layers of parallel flat plates, all shape factors S _r are S _rk =1 (k=1, 2, 3). In addition, the ultrasonic sensor is an ultrasonic sensor in a frequency band in which there is no scattering attenuation from the material. Also, let the thickness of the first layer be z ₁ , the thickness of the second layer be z ₂ , and the thickness of the third layer be z ₃ . Furthermore, the reflectance at the interface between the first layer and the second layer is X ₁ and the transmittance is 1-X ₁ , and the reflectance at the interface between the second layer and the third layer is X ₂ and the transmittance is 1-X ₂ .

Next, the relationship between the close range sound field limit distance d _N (distance z) of the ultrasonic sensor described in this embodiment and the propagation attenuation term d(z) will be described.

FIG. 5 is an explanatory diagram illustrating the relationship between the close range sound field limit distance d _N (distance z) and the propagation attenuation term d(z) of the ultrasonic sensor described in this embodiment.

In addition, the horizontal axis of Figure 5 shows the distance d _N (time The influence of the attenuation term d(z) propagates the attenuation term d(z) (for example, V).

As an ultrasonic sensor, as shown in Figure 5, select the close sound field limit distance ( d _N =A ² /(4λ)) becomes an ultrasonic sensor less than 1/2 of the thickness of the first layer. The transmitting and receiving intensity of the ultrasonic sensor is shown in Figure 5, which shows a tendency to be halved according to the distance. Therefore, for example, if it is normalized to d(z ₁ )=1, each d(z _k ) can be obtained by Expression 2.

Moreover, if the values obtained by correcting each echo intensity with the diffusion attenuation term d(z) are respectively defined as E1', E2', and E3', then E1', E2', and E3' can be expressed as Equation 3-1, Eq. 3-2, formula 3-3 general performance.

E ₁ ' =E ₁ /d(z ₁ )=K‧X ₁ ‧‧‧Equation 3-1

E ₂ ' =E ₂ /d(z ₁ +z ₂ )=K‧(1-X ₁ ) ² ‧X ₂ ‧‧‧Equation 3-2

E ₃ ' =E ₃ /d(z ₁ +z ₂ +z ₃ )‧Sr=K‧(1-X ₁ ) ² ‧(1-X ₂ ) ² ‧‧‧Equation 3-3

Select two expressions from this expression, divide each other, and eliminate the common term K.

Moreover, if it is defined as E ₁₂ '=E ₂ '/E ₁ ' and E ₂₃ '=E ₃ '/E ₂ ', it becomes an equation of unknown numbers, that is, 1-X ₁ and 1-X ₂ . If this equation is solved, it becomes Equation 4-1 and Equation 4-2.

(1-X ₁ )=-E ₁₂ ' /(2X ₂ )+(4X ₂ ‧E ₁₂ ' +E ₁₂ ' ² ) ^{1 2} /(2X ₂ )‧‧‧Equation 4-1

(1-X ₂ )=1-1/2‧(2+E ₂₃ ' -(E ₂₃ ' ‧(4+E ₂₃ ' )) ^{1 2} )‧‧‧Equation 4-2

Based on Formula 4-1 and Formula 4-2, find the unknown numbers, namely 1-X ₁ and 1-X ₂ . Specifically, based on Expression 4-2, 1-X ₂ is first displayed as the value of E ₂₃ . Next, using X ₂ represented by the value of E ₂₃ , based on Formula 4-1, 1-X ₁ is displayed using the values of E ₁₂ and E ₂₃ .

That is, by measuring the echo intensity E ₁ from the interface of the first layer and the second layer, the echo intensity E ₂ from the interface of the second layer and the third layer, and the echo intensity E ₃ from the bottom surface of the third layer, it can be Find the interface status index 1-X ₁ of the interface between layer 1 and layer 2, and the interface status index 1-X ₂ of the interface between layer 2 and layer 3.

Moreover, even in the case of 4 or more layers, it is the same as in the case of 3 layers. First, find the interface state index between the layers closest to the bottom surface, and then substitute the values in sequence, so that the interface state index between each layer can be calculated in sequence. Interface status indicator. The reason for this is that by dividing the strength of the bottom surface with respect to the layer closest to the bottom surface, the effect of passing through layers other than the layer closest to the bottom surface is eliminated.

In this way, according to this embodiment, it is possible to evaluate the interface status without obtaining a static interface that serves as a reference for ultrasonic measurement results.

Next, the acquisition waveform in the case of three layers described in this embodiment will be described.

FIG. 6 is an explanatory diagram illustrating the acquired waveform in the case of three layers described in this embodiment.

That is, FIG. 6 shows the obtained waveform obtained when measuring by an ultrasonic sensor. In addition, the horizontal axis of Fig. 6 is the distance z (for example, mm), and the vertical axis of Fig. 5 is the reception intensity E (for example, V).

As shown in Figure 6, obtain the echo intensity E ₁ from the interface of the first layer and the second layer, the echo intensity E ₂ from the interface between the second layer and the third layer, and the echo intensity E ₃ from the bottom surface of the third layer. .

In addition, although multiple echoes are also obtained, when calculating the interface state index, the multiple echo intensity is extremely small compared with the echo intensity E ₁ , echo intensity E ₂ , and echo intensity E ₃ , so it can be basically ignored.

Specifically, since each echo intensity is corrected by the diffusion attenuation term d(z), the thickness of the first layer is set to 100mm, the thickness of the second layer is set to 80mm, and the thickness of the third layer is set to 110mm. Among the four different positions (measurement points) No. 1 to No. 4 on the outer surface, the interface status is evaluated by ultrasonic measurement.

Based on the ultrasonic measurement results (echo intensity E ₁ , echo intensity E ₂ , echo intensity E ₃ ), equation 3-1, equation 3-2, equation 3-3, equation 4-1, and equation 4-2 are used, whereby Evaluate interface status. Table 1 shows the evaluation results of the interface status based on the ultrasonic measurement results (interface status index 1-X ₁ , interface status index 1-X ₂ ). In addition, in Table 1 (acquisition results of interface state indicators in the case of three layers), the echo intensity E ₁ , the echo intensity E ₂ , and the echo intensity E ₃ are expressed in %.

In addition, as shown in No. 1 of Table 1, when the echo intensity of E ₃ is not obtained, the interface state index 1-X ₂ of the second layer and the third layer becomes 0 (non-contact).

Furthermore, as shown in No. 2 of Table 1, even when the echo intensity of E ₃ is obtained as small as 1%, the interface state index 1-X ₂ of the second layer and the third layer is obtained to be 0.39.

Furthermore, as shown in No. 3 and No. 4 of Table 1, when the ratios of the echo intensity E ₁ , the echo intensity E ₂ , and the echo intensity E ₃ are the same, the interface state index 1-X ₁ of each and the interface Status indicators 1-X ₂ are the same.

That is, in the case of either No. 3 or No. 4 in Table 1, the echo intensity E ₁ : the echo intensity E ₂ : the echo intensity E ₃ is 5:4:2, and the interface state index of each is 1 -X ₁ is the same as 0.86, and the interface status indicator 1-X ₂ is the same as 0.77.

In this way, according to this embodiment, it can be seen that the influence of the setting factors of the flaw detector, the gain of the device, or the unstable contact factors do not affect the interface status index.

Furthermore, in this embodiment, as long as E _k (1≦k≦N-1) does not become 0%, zero ratio does not occur, so the interface state index 1-X _k can definitely be obtained.

Furthermore, according to this embodiment, even for a structure having a static fitting portion such as a heat-fitting part that is difficult to load or unload, it is possible to obtain the interface using the echo intensity that can be stably obtained without obtaining a reference ultrasonic measurement result. Status indicator 1-X _k .

Furthermore, according to this embodiment, since the deviation of the numerical value range obtained between each layer is small, and the interface status index 1-X _k is displayed in the range of 0 to 1, the interface status between each layer can be evaluated uniformly.

Furthermore, according to this embodiment, even when the surface state in contact with the ultrasonic sensor is not fixed, there is no need to repeatedly send and receive ultrasonic waves, which can shorten the evaluation time of the interface state.

In this way, in this embodiment, an equation is established about the echo intensity from each interface (between each layer) and the echo intensity from the bottom surface, eliminating the factors of the flaw detector's setting, the gain of the device, or the unstable contact and solving the problem Equation, by which the interface state index that is closely related to the interface state can be estimated without obtaining the echo intensity as a reference.

That is, in this embodiment, in the case of an N-layer structure (a structure having an interface of (N-1)), ultrasonic waves are transmitted and received from one side (one surface), and the ultrasonic wave from (N-1) is used. The echo intensity of the interface and the echo intensity from the bottom surface after passing through N layers are used to establish N equations showing the relationship between the echo intensity modified by the diffusion attenuation term d(z) and the interface state index.

Furthermore, in the two adjacent layers, divide the echo intensity on the lower side (the side closer to the bottom) by the echo intensity on the upper side (the side farther from the bottom) to eliminate the common term K (eliminate the setting factor of the flaw detector, The gain of the device or the cause of unstable contact), establish N-1 equations.

Moreover, first, the interface status index is obtained for the interface between the N layer and the N-1 layer. Based on the obtained interface status index, the interface status index is obtained for the interface between the N-1 layer and the N-2 layer. Then, for The interface between N-2 layer and N-3 layer, the interface between N-3 layer and N-4 layer. ． ． , find the interface status indicator.

Through this, the interface status index of each interface can be obtained, and the interface status of each interface can be evaluated.

In a structure having a static fitting portion, the interface state of the fitting portion affects mechanical properties (physical quantities) such as maximum torque and sliding. However, since the interface state of the fitting portion cannot be directly measured (observed), it needs to be indirectly evaluated (presumed) through ultrasonic measurement.

In dynamic interfaces with repeated contact and non-contact, it is only necessary to obtain the ultrasonic reflection wave intensity when the interface is non-contact as a reference, obtain the ultrasonic reflection wave intensity when the interface to be evaluated is in contact, and compare them, and then evaluate interface status. However, this method cannot be used in a structure with a static fitting portion.

Therefore, in this embodiment, ultrasonic waves are sent and received from the outer surface. Based on the acquired waveform data (obtained waveform), the echo intensity of the reflected waves from each interface and the echo intensity of the reflected waves from the bottom surface are determined according to the propagation distance or shape. Factor, correct the intensity of each echo, solve the equation, and calculate the interface status indicator.

Moreover, by monitoring the interface status indicators, the soundness of the structure in use can be evaluated, the interface status indicators and mechanical characteristics can be associated, and the quality of the structure during manufacturing can be managed.

Next, the measurement and evaluation process of the ultrasonic measurement method described in this embodiment will be described.

FIG. 7 is an explanatory diagram illustrating the measurement and evaluation flow of the ultrasonic measurement method described in this embodiment.

Hereinafter, the ultrasonic measurement method described in this embodiment has the following steps (procedure).

In S001, the evaluation of the interface state using ultrasonic measurement begins.

In S002, set a plurality of measurement points (all X points) on the external surface of the structure.

In S003, set the ultrasonic sensor at the set measurement point i (i≦X) and start measurement.

In S004, the sending and receiving of the ultrasonic sensor is first started. In addition, when receiving ultrasonic waves and obtaining waveform data, according to the echo intensity of the bottom surface of the structure, it is better to adjust the contact of the ultrasonic sensor in such a way that the echo intensity of the bottom surface of the structure becomes the maximum.

Then, in the control/processing unit (computer) of the ultrasonic measuring device described later, the echo intensity (peak value) E _k (1≦k≦N) of each interface and the bottom surface is extracted from the acquired waveform data.

Next, each E _k is corrected in the control/processing unit of the ultrasonic measurement device described later. The correction is performed based on input of the thickness z _k of each layer, the shape factor S _rk of each layer, and the material density and sonic velocity (acoustic impedance) of each layer.

Next, in the control/processing unit of the ultrasonic measurement device described later, the equations regarding the acquired N echo intensities E _k are solved. When solving equations, use the above equations 1-1, 1-2, 1-3, and 1-4 to establish N equations, calculate E _k-1 /E _k , eliminate the common term K, and solve N -1 equation to find the interface state index 1-X _k-1 .

And, the calculated interface state index 1-X _k-1 (1≦k≦N) is output.

In S005, the measurement of measurement point i ends.

In S006, it is determined whether the measurement is completed at all set measurement points (i=X). If the measurement of all measurement points is completed, proceed to S007. If the measurement of all measurement points is not completed, return to S003 and repeat S004 and S005.

In S007, since only a very limited interface state directly below the ultrasonic sensor can be evaluated as needed, it is better to collect a larger number of measurement points and calculate the average or deviation.

In S008, for example, as shown in FIG. 8 described later, the interface status indicator and the mechanical characteristics can be associated to manage the quality of the structure during manufacturing. In addition, as shown in Figure 9 described later, the time changes of the interface status indicators can also be monitored to evaluate the soundness of the structure in use.

In S009, the evaluation of the interface state using ultrasonic measurement is completed.

That is, the ultrasonic measurement method described in this embodiment evaluates the interface state of a structure having an N-1 static interface formed by N layers.

Moreover, the ultrasonic measurement method has the following steps: transmit and receive ultrasonic waves from the outer surface of the structure, and based on the obtained waveform data, capture the echo of the reflected wave corresponding to the distance from each interface of N-1 to the outer surface of the structure. The intensity, and the echo intensity of the reflected wave corresponding to the distance from the bottom surface of the N layer after passing through the N layer to the outer surface of the structure; compare the echo intensity of the reflected wave from such interfaces with the echo intensity of the reflected wave from such bottom surface The echo intensity is divided by the diffusion attenuation term that depends on the propagation distance of the ultrasonic wave, and N equations are established showing the relationship between the calculated echo intensity and the interface state index that is proportional to the real contact area, and the lower side is calculated. Divide the echo intensity calculated by the above division, eliminate the common terms, solve the N-1 equations showing the relationship between the echo intensity and the interface status index, use the echo intensity to display the interface status index, and calculate the interface status index of each interface ; and based on the calculated interface status indicators of each interface, evaluate the interface status of each interface.

This makes it possible to evaluate the interface status even if it is not possible to obtain a static interface that serves as a reference for ultrasonic measurement results.

Next, the relationship between the interface state index and the mechanical characteristics described in this embodiment will be described. FIG. 8 is an explanatory diagram illustrating the relationship between the interface state index and the mechanical characteristics described in this embodiment. As shown in Figure 8, based on the relationship between the interface state index and the mechanical properties obtained in advance of the structure, the obtained interface state index can be associated with the mechanical properties of the structure, and can be used in the structure during manufacturing. The quality of things. That is, in this embodiment, the calculated interface state index of each interface is associated with the mechanical characteristics of the structure, and the calculated interface state index of each interface is used for quality management of the structure during manufacturing.

Next, the relationship between time and interface status indicators described in this embodiment will be described. FIG. 9 is an explanatory diagram illustrating the relationship between time and interface status indicators described in this embodiment. As shown in Figure 9, the temporal changes of the interface status indicators of the structural part can be monitored and used to evaluate the soundness of the structure in use. That is, in this embodiment, the interface status index of each interface obtained is monitored based on the time change (measurement time), and the interface status index of each interface obtained is used to evaluate the soundness of the structure in operation. .

Next, the ultrasonic measuring device described in this embodiment will be described.

FIG. 10 is an explanatory diagram illustrating the ultrasonic measuring device described in this embodiment.

The ultrasonic measurement device described in this embodiment has: a measurement part 1, which has an ultrasonic sensor 2 that transmits and receives ultrasonic waves to the structure (object to be measured 3); a transceiver part (pulse generator/receiver) 4, It sends and receives the signal generated by the ultrasonic sensor 2, and processes the signal generated by the ultrasonic sensor 2 and the signal of the reflected wave; the control/processing part (computer) 5; the display part 6; and the input device 7.

In addition, the measurement unit 1 has an ultrasonic sensor 2 and a holding mechanism unit (not shown) for holding the ultrasonic sensor 2 .

The transmitting and receiving unit 4 transmits and receives ultrasonic waves based on the values of the measurement conditions (shape of the transmission pulse, voltage, repetition frequency, amplification value, etc.) stored in the memory device 51 of the control/processing unit 5 . In addition, these can also be input from the input device 7 .

In addition, the received wave of the transceiver unit 4 is amplified or A/D (Analog/Digital: analog/digital) converted, etc., to obtain waveform data, and stored in the memory device 51 of the processing/control unit 5 .

The control/processing unit 5 includes a memory device 51 , a processing device 52 , and a transmission and reception control device 53 .

The memory device 51 has a database (DB) for measurement evaluation and a database (DB) for status management.

In the database for measurement and evaluation, the measurement points, measurement conditions, set number of layers and thickness of the layers, shape factors required for correction of echo intensity, correction items, waveform data, and adjustment calculations in accordance with the set number of layers are stored. Algorithm of equations for interface status indicators, etc.

In the database for status management, the interface status indicators calculated based on the measurement results are associated and stored with the measurement time and date, measurement points, and mechanical characteristics.

The processing device 52 retrieves the echo intensity from the received waveform, and calculates the interface status indicator based on the echo intensity retrieved from the stored algorithm. In addition, in the correction of the diffusion attenuation term d(z), the thickness of the layer can be input in advance as the shape information of the structure 3. The position of the received wave can also be evaluated from the received waveform as needed, and the thickness of the layer can be evaluated and input.

The transceiver control device 53 controls the shape, voltage, pulse width, repetition frequency, amplification value, sampling frequency, data storage timing, etc. of the received pulse.

The display unit 6 displays the control value of ultrasonic transmission and reception, the value required for evaluation conditions, the original waveform of the measurement, the calculation result of the interface status index, and the relationship between the interface status index and the mechanical characteristics as shown in Figure 8 or 9 ( Chart) or the relationship between time (measurement date) and interface status indicators (chart). In addition, the display unit 6 displays the evaluation results (table) of the interface state based on the ultrasonic measurement results shown in Table 1.

The input device 7 is a general input mechanism (input machine) such as a keyboard, a mouse, and a touch panel.

In addition, although it is not essential, the ultrasonic measurement device may include a scanner 8 for scanning the ultrasonic sensor 2 . Furthermore, the control/processing unit 5 is provided with a scanner control device 54 that controls the scanner 8 .

In addition, the scanner 8 fixes, scans, and moves the ultrasonic sensor 2 . The scanner control device 54 causes the ultrasonic sensor 2 or the structure 3 to scan and move within the set timing and range based on the scanning conditions stored in the processing/control unit 5, and causes the ultrasonic sensor 2 and the structure to move. 3. The relative positional relationship changes.

In addition, the present invention is not limited to the following examples and includes various modifications. For example, the following examples illustrate the present invention in order to make it easier to understand, and the specific description is not limited to those having all the components described.

In addition, part of the components of one embodiment may be replaced with one of the components of another embodiment. part. In addition, the configuration of another embodiment may be added to the configuration of a certain embodiment. In addition, part of the components of each embodiment may be deleted, part of other components may be added, and part of other components may be replaced.

S001~S009: steps

Claims (10)

An ultrasonic measurement method, characterized in that it is an ultrasonic measurement method for evaluating the interface state of a structure having a static interface of N-1 formed by N layers, and has the following steps: transmitting and receiving from the outer surface of the structure Ultrasound, based on the obtained waveform data, extracts the echo intensity from each interface of N-1 and the echo intensity from the bottom surface of the N layer; divides the echo intensity from each interface and the echo intensity from the bottom surface by the ultrasonic wave For the diffusion attenuation term of the propagation distance, establish N equations showing the relationship between the calculated echo intensity and the interface state index that is proportional to the real contact area. Divide the calculated echo intensity on the side close to the bottom surface, that is, the lower side. Divide the calculated echo intensity on the side far away from the bottom surface, that is, the upper side, eliminate the common terms in N equations, solve the N-1 equations showing the relationship between echo intensity and interface status indicators, and use the echo intensity to display the above interface status indicators. , calculate the interface status indicator of each interface; and evaluate the interface status of each interface based on the calculated interface status indicator of each interface. The ultrasonic measurement method of claim 1, wherein the echo intensity from each interface of N-1 and the bottom surface of N layer are corrected based on the shape factor of the reflectivity of the above-mentioned interface and the above-mentioned bottom surface due to the shape of each layer. The echo intensity, establish the above N equations. Such as the ultrasonic measurement method of claim 1, wherein the calculated interface status index of each interface is associated with the mechanical characteristics of the structure, and the calculated interface status index of each interface is used for quality management of the structure during manufacturing. . Such as the ultrasonic measurement method of claim 1, wherein the calculated interface status index of each interface is monitored, and the calculated interface status index of each interface is used to evaluate the soundness of the structure in use. An ultrasonic measurement device, characterized in that it is an ultrasonic measurement device for evaluating the interface state of a structure having an N-1 static interface formed by N layers, and is based on the transmission and reception of ultrasonic waves from the outer surface of the structure. The waveform data obtained by the ultrasonic sensor captures the echo intensity from each interface of N-1 and the echo intensity from the bottom surface of the N layer; divide the echo intensity from each interface and the echo intensity from the bottom surface by The diffusion attenuation term of the ultrasonic propagation distance is used to establish N equations showing the relationship between the calculated echo intensity and the interface state index that is proportional to the real contact area. The calculated echo intensity is divided by the side close to the bottom surface, that is, the lower side. Divide the calculated echo intensity by the side far away from the bottom, that is, the upper side, eliminate the common terms in N equations, solve the N-1 equations showing the relationship between echo intensity and interface status indicators, and display the above interface in terms of echo intensity. The status indicator calculates the interface status indicator of each interface; and has a control/processing unit that evaluates the interface status of each interface based on the calculated interface status indicator of each interface. The ultrasonic measuring device of claim 5, wherein the control/processing unit has the function of storing the set number of layers and the thickness of the layers, the shape factor due to the shape of each layer required for correction of the echo intensity, and the coordinates of the set layers. number adjustment operation boundary A memory device for the algorithm of the equation of the surface state indicator. Such as the ultrasonic measurement device of claim 6, wherein the memory device associates the interface state indicator calculated based on the measurement results with the mechanical characteristics and stores them. Such as the ultrasonic measurement device of claim 6, wherein the memory device associates the interface status indicator calculated based on the measurement results with the measurement time and date, and stores the same. The ultrasonic measuring device of claim 7 has a display part that displays the relationship between the interface status indicator and the mechanical characteristics. The ultrasonic measuring device of claim 8 has a display part that displays the relationship between the interface status indicator and the measurement time and date.