JP6999234B2 - Ultrasonography equipment - Google Patents

Description

The present invention relates to an ultrasonic inspection device, and more particularly to an ultrasonic inspection device that visualizes an object to be measured existing in a medium.

Conventionally, an ultrasonic transmission means for emitting ultrasonic waves and an optical fiber for irradiating and incident laser light are provided, and a reflected wave (received signal) of the ultrasonic waves emitted from the ultrasonic transmission means by an object to be measured is obtained. An ultrasonic inspection device that receives an image via the optical fiber and analyzes the received signal to image the object to be measured is known (see, for example, Patent Documents 1 and 2 below).

However, in the above-mentioned conventional technique, for example, as shown in FIG. 9, a part 65, 66 of the reflected wave 62 from the object to be measured propagates inside the sensor body 01 and receives the signal through the receiving surface 02. There is a problem that when the point P is reached, the noise of the original received signal (actual signal) becomes noise, which causes deterioration of the image when the object to be measured is imaged. Further, when a plurality of receiving sensors are provided for one transmitting sensor and imaging is performed by aperture synthesis processing, it is necessary to provide a large number of receiving sensors in order to improve the receiving sensitivity. In short, there was also the problem of increasing the cost of the equipment.

On the other hand, a propagation prevention plate (not shown) made of fluororubber or the like is provided between the sensor body 01 and the receiving surface 02, and most of the reflected wave 62 is reflected by the difference in acoustic impedance to generate the reflected wave 62. It is also known that the sensor body 01 is prevented from propagating inside (see, for example, Patent Document 3 below).

Japanese Patent No. 3021176 Japanese Patent No. 4898247 Japanese Unexamined Patent Publication No. 2016-176908

However, while the invention described in Patent Document 3 can obtain an excellent ultrasonic damping effect in a normal temperature environment, the ultrasonic damping effect changes depending on the environmental conditions, and particularly in a high temperature environment, the ultrasonic damping effect changes in a normal temperature environment. The ultrasonic attenuation effect is reduced in comparison, for example, in a high-speed furnace using opaque liquid sodium as a cooling material, in a state where high-temperature (200 ° C.) liquid sodium is in the container or the like while the operation is stopped, the inside of the container is in the state of being in the container or the like. When trying to image the internal structure, there is a problem that it is difficult to obtain the same ultrasonic attenuation effect as in a normal temperature environment.

Therefore, it is an object of the present invention to provide an ultrasonic inspection apparatus capable of reducing noise superimposed on a received signal and improving visibility in imaging regardless of environmental conditions. And.

The ultrasonic inspection apparatus according to the first invention for solving the above problems is
A transmission sensor that transmits ultrasonic waves to the object to be measured existing in the medium,
A support having a through hole and a receiving sensor having a metal film body covering the through hole and the surface of the support are provided.
An ultrasonic inspection device that analyzes the vibration of the metal film body due to the reflected wave of the ultrasonic wave reflected by the object to be measured and visualizes the object to be measured.
All or part of the support consists of magnets and
The metal film body is made of a ferromagnetic material.
It is characterized in that the metal film body is attracted to the support by a magnetic force.

Further, the ultrasonic inspection apparatus according to the second invention is the ultrasonic inspection apparatus according to the first invention.
It is characterized in that the entire support is composed of the magnet formed in a plate shape.

Further, the ultrasonic inspection apparatus according to the third invention is the ultrasonic inspection apparatus according to the first invention.
The support is composed of a metal material which is made of a ferromagnet and has a through hole, and a magnet which is in contact with the metal material and applies a magnetic force to the metal material.
The metal film body is characterized by being adsorbed on the metal material by a magnetic force.

Further, the ultrasonic inspection apparatus according to the fourth invention is the ultrasonic inspection apparatus according to the third invention.
The magnet is characterized in that it is formed in a frame shape along the outer peripheral edge of the metal film body.

According to the ultrasonic inspection apparatus according to the present invention described above, it is possible to reduce noise superimposed on the received signal regardless of environmental conditions and relatively improve the signal strength of the received signal. This makes it possible to improve the visibility when the object to be measured is visualized by image processing even in a high temperature environment. Further, even in a high temperature environment, when a plurality of receiving sensors are provided for one transmitting sensor and the object to be measured is visualized by aperture synthesis processing, the conventional ultrasonic inspection is performed even if the number of effective receiving points is reduced. Since the same visibility as the device can be ensured, the manufacturing cost can be reduced by reducing the number of receiving sensors.

It is a schematic block diagram of the ultrasonic inspection apparatus which concerns on Example 1 of this invention. It is sectional drawing which shows the II-II arrow view part of the sensor part shown in FIG. It is a figure explaining the structure of the receiving sensor in the part III of the sensor part shown in FIG. It is an enlarged view of the main part of FIG. It is a graph which shows an example of the received ultrasonic waveform acquired in the high temperature environment by the ultrasonic inspection apparatus which concerns on Example 1 of this invention. It is a graph which shows an example of the received ultrasonic waveform acquired in the high temperature environment by the ultrasonic inspection apparatus which applied the propagation prevention plate made from the conventional fluororubber. It is a graph which shows an example of the received ultrasonic waveform acquired in the normal temperature environment by the ultrasonic inspection apparatus which concerns on Example 1 of this invention. It is a graph which shows an example of the received ultrasonic waveform acquired in the normal temperature environment by the ultrasonic inspection apparatus to which the propagation prevention plate made of a conventional fluororubber was applied. It is sectional drawing which shows the sensor part of the ultrasonic inspection apparatus which concerns on Example 2 of this invention. FIG. 7 is an enlarged view of part VIII of FIG. It is explanatory drawing which shows the example of the reflected wave propagating in the inside of the conventional sensor main body and the receiving surface.

Hereinafter, the details of the ultrasonic inspection apparatus according to the present invention will be described with reference to the drawings.

The ultrasonic inspection apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 6B.
As shown in FIG. 1, the ultrasonic inspection apparatus according to the present embodiment includes a sensor unit 10 having a transmission sensor 11 and a reception sensor 12, an optical processing unit 20 that converts an optical signal into an electric signal, and an optical processing unit 20. It is provided with a visualization unit (for example, a monitor or the like) 30 for imaging an object to be measured 50 (see FIG. 2) by performing aperture composition processing (image processing) based on an electric signal input from.
The configurations of the optical processing unit 20 and the visualization unit 30 are the same as those known, and detailed description thereof will be omitted here.

As shown in FIGS. 1 and 2, a plurality (for example, 9) transmission sensors 11 are provided inside the frame-shaped housing 13 in this embodiment, and are formed on a backup plate 14 as a support to be described later. It is two-dimensionally and intermittently arranged and fixed in the through hole for the transmission sensor so as to be separated from each other at regular intervals. The transmission sensor 11 is composed of, for example, a piezoelectric element, and emits ultrasonic waves to the object to be measured 50.
Reference numeral 40 in FIG. 2 is a medium (for example, opaque liquid sodium or the like).

Further, the receiving sensor 12 has a backup plate 14 having a large number (for example, about 2500) through holes (hereinafter referred to as reception sensor through holes) 14c to cover the opening of the housing 13, and the backup plate 14 of the backup plate 14. It is provided with a diaphragm (metal film body) 16 that covers the surface and the through hole 14c for the receiving sensor.

In this embodiment, the backup plate 14 is composed of a plate-shaped magnet (for example, a neodymium magnet having a Curie temperature of more than 200 ° C., a samarium cobalt magnet, or the like), and is fixed to the inner peripheral surface of the housing 13. A plurality of through holes 14c for receiving sensors are two-dimensionally arranged around each transmitting sensor 11 so as to be separated from each other at regular intervals.

Further, the diaphragm 16 is formed of a metal foil made of a ferromagnetic material such as nickel. The portion of the diaphragm 16 facing the transmission sensor 11 is open, so that the transmission surface of the transmission sensor 11 is exposed. Only the outer peripheral edge of the diaphragm 16 is welded to the housing 13, and the other parts are magnetically attracted to the backup plate 14.

Further, as shown in FIGS. 3 and 4, the optical fiber 15 is fixed in the through hole 14c for the receiving sensor of the backup plate 14 in a non-contact manner with the diaphragm 16, and the tip of the optical fiber 15 is fixed to the diaphragm 16. It is in a state of being covered with non-contact. More specifically, as shown in FIG. 4, the optical fiber 15 has a backup plate via a ferrule 17 so that the tip thereof is positioned inside the surface of the backup plate 14 on the diaphragm 16 side (the side opposite to the diaphragm 16). It is fixed at 14.

As a result, as shown by the broken line in FIG. 3, in the diaphragm 16, the portion covering the receiving sensor through hole 14c is the object to be measured of the ultrasonic wave 61 emitted from the transmitting sensor 11 (see FIGS. 1 and 2). It can be vibrated by the reflected wave 62 reflected by the 50.

Further, in the receiving sensor 12, the diaphragm 16 is irradiated with the laser beam (hereinafter referred to as inspection laser beam) 63 via the optical fiber 15, and the reflected laser beam 64 reflected by the diaphragm 16 of the inspection laser beam 63 is emitted. It is designed to be incident on the optical fiber 15. That is, the reception sensor 12 is configured to capture the vibration of the diaphragm 16 as a modulation of the reflected laser light 64 with respect to the inspection laser light 63 and receive this as a reception signal (pulse).

In addition, in FIGS. 3 and 4, in order to make it easy to understand the relationship between the optical fiber 15 and the diaphragm 16, the distance between the optical fiber 15 and the diaphragm 16 is exaggerated. Further, it goes without saying that the thickness of the backup plate 14 shown in FIGS. 2 and 4 is an example and can be appropriately changed as needed.

The effects of the ultrasonic inspection device according to this embodiment will be described below.
As shown in FIG. 3, the ultrasonic wave 61 emitted from the transmission sensor 11 (see FIGS. 1 and 2) is reflected by the object to be measured 50 and is reflected by the sensor unit 10 (see FIGS. 1 and 2) as a reflected wave 62. Come back. On the other hand, the inspection laser beam 63 emitted from the optical fiber 15 is reflected by the diaphragm 16 as described above, and is incident on the optical fiber 15 as the reflected laser beam (received signal) 64.

Here, when the reflected wave 62 emitted from the transmission sensor 11 and reflected by the object to be measured reaches the diaphragm 16, the diaphragm 16 vibrates as described above, and the reflected laser light 64 reflected by the diaphragm 16 thereby vibrates. Is modulated as compared to the inspection laser beam 63.

In the ultrasonic inspection apparatus of this embodiment, the light modulation between the inspection laser light 63 and the reflected laser light 64 obtained by the receiving sensor 12 is converted into an electric signal by the optical processing unit 20 and visualized by the visualization unit 30. The shape of the object to be measured 50 is imaged by performing the aperture synthesis process.

Next, using FIGS. 5A to 6B, the received ultrasonic waveform by the ultrasonic inspection device according to the present embodiment and the received ultrasonic waveform by the ultrasonic inspection device adopting the propagation prevention plate made of conventional fluororubber. The results of the comparison will be described.

First, as shown in FIG. 5A, in the ultrasonic inspection apparatus according to the present embodiment, the ratio of the signal level between the received signal and the noise is about ± in a high temperature environment (specifically, in liquid sodium at 200 ° C.). 110 (mV): ± 25 (mV), in other words, the signal level of noise with respect to the received signal is about 0.23, whereas as shown in FIG. 5B, a propagation prevention plate made of conventional fluororubber or the like is used. In the provided one, the ratio of the signal level of the received signal and the noise is about ± 40 (mV): ± 20 (mV) in a high temperature environment, in other words, the signal level of the noise with respect to the received signal is about 0.5. It can be seen that in the ultrasonic inspection apparatus of this embodiment, the signal level of noise with respect to the received signal is significantly reduced as compared with the conventional one in a high temperature environment.

Further, as shown in FIG. 6A, in the ultrasonic inspection apparatus according to the present embodiment, the ratio of the signal level between the received signal and the noise is about ± 80 (specifically, in water at 20 ° C.). mV): ± 20 (mV), in other words, the signal level of noise with respect to the received signal is about 0.25, whereas as shown in FIG. 6B, a propagation prevention plate made of conventional fluororubber or the like is provided. In a normal temperature environment, the ratio of the signal level of the received signal to the noise is about ± 70 (mV): ± 15 (mV), in other words, the signal level of the noise with respect to the received signal is about 0.21. It can be seen that the ultrasonic inspection device of the example has the same performance as the conventional one in a normal temperature environment, and can sufficiently suppress the signal level of noise with respect to the received signal.

That is, in the ultrasonic inspection apparatus according to the present embodiment, the backup plate 14 is formed by a magnet and the diaphragm 16 is configured to be attracted to the backup plate 14 by magnetic force, so that the backup plate 14 and the diaphragm 16 are adhered to each other. The substantial contact area between the backup plate 14 and the diaphragm 16 can be reduced as compared with the case of fixing. Therefore, as compared with the conventional ultrasonic inspection device as shown in FIG. 9 and as described above, a part of the reflected wave incident on the inside of the backup plate 14 with respect to the reflected wave 62 reflected by the object to be measured 50. It is possible to reduce 65 and suppress that a part of the reflected wave 65 becomes noise of the original received signal.
Further, the vibration of the diaphragm 16 can be suppressed by the damper effect due to the attractive force of the magnet, and the diaphragm 16 (that is, the receiving surface) is compared with the conventional ultrasonic inspection device as shown in FIG. 9 and described above. It is also possible to reduce that a part of the reflected wave 66 propagating on the surface affects the original received signal as noise.

In this way, the ultrasonic inspection apparatus according to the present embodiment maintains the conventional performance in a normal temperature environment, and reduces the signal level of noise with respect to the received signal in a high temperature environment as compared with the conventional one. It is possible to improve the signal strength), and even in a high temperature environment, it is possible to suppress that some ultrasonic waves 65 are reflected inside the backup plate 14 and reach the diaphragm 16, and are superimposed on the received signal. It is possible to reduce the noise to be generated and relatively improve the signal strength of the received signal, and it is possible to improve the visibility of the visualized image. In addition, even if the number of effective receiving points is reduced in a high temperature environment, the visualized image can be assured as the conventional ultrasonic inspection device, so the manufacturing cost can be reduced by reducing the number of receiving sensors. It will be possible.

In the above-described embodiment, an example in which the transmission sensor 11 and the reception sensor 12 are integrally provided as the configuration of the sensor unit 10 is shown, but the transmission sensor 11 and the reception sensor 12 are integrally provided. It is not necessary, and it can be applied as long as it is a device including a transmission sensor that emits ultrasonic waves and a reception sensor that receives the reflected wave reflected by the object to be measured, and does not deviate from the gist of the present invention. Needless to say, various changes can be made within the range. This also applies to the examples shown below.

Further, in the above-described embodiment, an example in which a plurality of transmission sensors 11 are two-dimensionally arranged and a through hole 14c for a reception sensor is two-dimensionally arranged around the transmission sensor 11 is shown. The number of sensors 11 may be one, and the transmission sensor 11 and the through hole 14c for the reception sensor may be arranged one-dimensionally, and may be arranged as necessary.

Further, in the above-described embodiment, an example of using the laser beam transmitted via the optical fiber 15 as a means for detecting the vibration of the diaphragm 16 is shown, but as a means for detecting the vibration of the diaphragm 16, for example. Other means such as an oscillator can be used.

The ultrasonic inspection apparatus according to the second embodiment of the present invention will be described with reference to FIGS. 7 and 8.
The ultrasonic inspection apparatus according to this embodiment has a backup plate configuration different from that of the above-described first embodiment shown in FIGS. 1 to 4. Other configurations are substantially the same as those of the first embodiment described above. Hereinafter, only the configurations different from the first embodiment will be described, and detailed description of the same configurations as the first embodiment will be omitted.

As shown in FIGS. 7 and 8, in this embodiment, instead of the backup plate 14 shown in FIGS. 1 to 4 and described above, the metal material 71 made of a ferromagnetic material and the backup plate 14 are the same as the support. A magnet 72 made of the above material is used.

The metal material 71 is formed in a plate shape and has a large number of through holes 71c for a receiving sensor through which the ferrule 17 is inserted, and covers the opening of the housing 13, and the surface of the metal material 71 and the through holes for the receiving sensor. 71c is covered by the diaphragm 16. The metal material 71 is fixed to the housing 13, and only the outer peripheral edge of the diaphragm 16 is fixed to the metal material 71 by welding.

Further, the magnet 72 is formed in a frame shape along the outer peripheral edge of the diaphragm 16 (more specifically, along the inner peripheral surface of the housing 13), and is the back surface of the metal material 71 (the surface covered by the diaphragm 16). It is in contact with the opposite surface) and is fixed to the housing 13.

With this configuration, in the ultrasonic inspection apparatus of this embodiment, the magnet 72 is brought into contact with the metal material 71 covering the opening of the housing 13 to apply a magnetic force to the metal material 71, and the metal material is subjected to the magnetic force. The diaphragm 16 can be adsorbed on the 71.

Therefore, also in the ultrasonic inspection apparatus according to the present embodiment, the case where the diaphragm 16 is adhered to and fixed to the metal material 71 by magnetically adsorbing the diaphragm 16 to the metal material 71 covering the opening of the housing 13 is compared. As a result, the substantial contact area between the metal material 71 and the diaphragm 16 can be reduced, and thereby the same effect as that of Example 1 described above can be obtained.

Needless to say, the shapes (thickness, width, etc.) of the metal material 71 and the magnet 72 shown in FIGS. 7 and 8 are examples and can be appropriately changed as needed. Further, the magnet 72 does not necessarily have to be frame-shaped, as long as it can apply a magnetic force to the metal material 71.

The present invention is suitable for application to an ultrasonic inspection device that visualizes an object to be measured existing in a medium from a separated position.
As an example of use, in a high-speed furnace using opaque liquid sodium as a coolant, high-temperature (200 ° C) liquid sodium is inserted into the liquid sodium in the container while the operation is stopped and inside. It is suitable for an ultrasonic detection device used to visualize the state of a structure or the like.

01 Sensor body 02 Reception surface 10 Sensor unit 11 Transmission sensor 12 Reception sensor 13 Housing 14 Backup plate (magnet)
14c Through hole for receiving sensor 15 Optical fiber 16 Diaphragm 17 Ferrule 20 Optical processing unit 30 Visualization unit 40 Medium 50 Object to be measured 61 Ultrasonic 62 Reflected wave 63 Inspection laser light 64 Reflected laser light 65 Partial reflected wave 66 Reflected wave of part 71 Metal material 71c Through hole for receiving sensor 72 Magnet

Claims (4)

A transmission sensor that transmits ultrasonic waves to the object to be measured existing in the medium,
A plate-shaped support having a through hole, and a receiving sensor having a metal film body covering the through hole and the surface of the support.
A housing that houses the transmission sensor and the reception sensor,
Equipped with
An ultrasonic inspection device that analyzes the vibration of the metal film body due to the reflected wave of the ultrasonic wave reflected by the object to be measured and visualizes the object to be measured.
All of the surfaces of the support on the side in contact with the metal film body generate a magnetic force, and at the same time,
The metal film body is made of a ferromagnetic material.
An ultrasonic inspection apparatus characterized in that an outer peripheral edge of the metal film body is welded to the housing, and a portion other than the outer peripheral edge is attracted to the support by the magnetic force. The ultrasonic inspection apparatus according to claim 1, wherein the entire support is composed of a magnet formed in a plate shape. The support is composed of a metal material made of a ferromagnetic material and having the through hole, and a magnet that is in contact with the metal material to apply a magnetic force to the metal material, and the metal film body is formed by the magnetic force. The ultrasonic inspection apparatus according to claim 1, wherein the magnetic material is adsorbed to the metal material. The ultrasonic inspection apparatus according to claim 3, wherein the magnet is formed in a frame shape along the outer peripheral edge of the metal film body.

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