JPH04235343A - Ae sensor - Google Patents

Abstract

PURPOSE:To provide an AE sensor which can receive AE with high transmissibility without damaging material to be measured, can cope with various kinds of curved surfaces and has high universal applications. CONSTITUTION:A shape memory allay layer 13 having transformation temperature less than indemnified temperature is provided on an AE detecting surface of a main body 11 of an AE sensor. When the shape memory alloy layer 13 is pushed on a material to be measured having the curved surface, the shape memory alloy layer is deformed and brought into contact with the curved surface tightly. When the shape memory alloy layer 13 is brought into tight contact with a material to be measured having the different curved surface, the shape memory alloy layer 13 is once heated to temperature higher than the transformation temperature and less than the indemnified temperature of the main body of the AE sensor and returned to the original memory shape. Thereafter, the shape memory alloy layer 13 is pushed to the surface of the material to be measured and brought into tight contact with the material to be measured.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AE (acoustic emission) sensor.

0002

2. Description of the Related Art Conventionally, an AE sensor has a flat AE detection surface, and this AE detection surface is brought into contact with the surface of an object to be measured to receive AE.

0003

However, the conventional AE sensor described above has the following problems because it detects AE by bringing the flat AE detection surface into contact with the object to be measured.

FIGS. 3, 4, and 5 are diagrams showing a method of detecting AE from a measurement object having a curved surface using a conventional AE sensor.

In the method shown in FIG. 3, the flat AE detection surface 2 of the AE sensor 1 is brought into contact with the curved surface of the object 3 to detect AE. In this case, the A of AE sensor 1
Since the E detection surface 2 comes into contact with one point or one line of the object to be measured, there is a problem that the AE transmission rate decreases and the detection accuracy of the AE sensor 1 decreases.

In the method shown in FIG. 4, the surface of the object 3 to be measured is ground to form a flat surface 4, and the AE of the AE sensor 1 is applied to this flat surface 4.
This is a method of detecting AE by bringing the detection surface 2 into contact. This method damages the surface of the object to be measured 3, so this method cannot be used if the surface of the object to be measured 3 cannot be damaged. Moreover, this method requires the surface of the measurement object 3 to be scraped, which is time-consuming.

In the method shown in FIG. 5, a curved surface corresponding to the curved surface and a flat surface in contact with the AE detection surface 2 are provided between the flat AE detection surface 2 of the AE sensor 1 and the measurement object 3 having a curved surface. This is a method using an inspection jig 5. This method does not damage the measurement object 3 and has good AE detection accuracy. However, this method has the problem that the jig 5 must be changed depending on the curved surface of the object 3 to be measured, and is not versatile.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an AE sensor that has a high AE transmissibility, does not damage an object to be measured, and is highly versatile.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the AE sensor of the present invention has an AE sensor of the AE sensor body.
It is characterized in that a shape memory alloy layer having a transformation temperature lower than the guaranteed temperature of the AE sensor body is provided on the detection surface.

0010

[Operation] The shape memory alloy layer of this AE sensor is pressed against the curved surface of the object to be measured, deforming the shape memory alloy layer and bringing the shape memory alloy layer into close contact with the curved surface of the object. Then, AE from the object to be measured is transmitted to the AE detection surface of the AE sensor body through this shape alloy layer, increasing the transmission rate of AE. When measuring other objects with different curved surfaces, the shape memory alloy layer of this AE sensor must be heated at a temperature above the transformation temperature and at A
After heating the E-sensor body below its guaranteed temperature to return it to its original shape, this shape memory alloy layer is again pressed against the curved surface of the object to deform it, bringing the shape memory alloy layer into close contact with the curved surface of the object. let By doing so, this shaped alloy layer can be brought into close contact with various curved surfaces, increasing its versatility.

[0011] Furthermore, the shape memory alloy layer of the AE sensor is made of A
Since the transformation temperature is below the guaranteed temperature of the E sensor, A
When the E sensor becomes high temperature for some reason, the shape memory alloy layer returns to its original shape, so it can detect that the AE sensor has been exposed to high temperature, and the AE
The sensor can detect whether the ambient temperature has reached a dangerous temperature.

0012

[Example] In FIGS. 1 and 2, 10 is an AE sensor;
1 is an AE sensor body, and 13 is a shape memory alloy layer adhered to the flat AE detection surface 12 of the AE sensor body 11. As shown in FIG. 2, the shape memory alloy layer 13 has a cylindrical shape with flat end faces, and has a transformation temperature slightly lower than the guaranteed temperature of the AE sensor body 11.

When measuring an object 3 having a curved surface with the AE sensor 10, as shown in FIG. The memory alloy layer 13 is deformed and brought into close contact with the curved surface of the measurement object 3. By doing this, the AE from the object to be measured 3 is transmitted to the AE detection surface 12 of the AE sensor 11 through the shape memory alloy layer 13 that is in close contact with the curved surface of the object to be measured 3, and the AE from the object to be measured 3 is can be detected with high accuracy.

When measuring another object having a curved surface different from the curved surface of the object 3, this AE sensor 10
The shape memory alloy layer 13 is heated to a temperature above its transformation temperature and below the guaranteed temperature of the AE sensor body to restore its original shape as shown in FIG. 2, and the shape memory alloy layer 13 is again pressed against the curved surface of the object Bring it into close contact.

[0015] By doing this, the shape memory alloy layer 13 comes into close contact with the objects to be measured having various curved surfaces, and the AE from the objects to be measured having various curved surfaces can be transmitted to the AE sensor main body 11 with a high transmission rate. can. Therefore, versatility is increased.

As described above, the AE sensor 10 does not need to damage the surface of the object to be measured, can come into close contact with the object to be measured having a curved surface, and is highly versatile.

Further, when the ambient temperature of this AE sensor 10 becomes higher than the transformation temperature of the shape memory alloy layer 13, the shape memory alloy layer 13 having a curved surface corresponding to the curved surface of the measurement object 3 changes as shown in FIG. As shown in the figure, since it returns to its original shape, it is possible to detect when the ambient temperature has reached a dangerous temperature close to the guaranteed temperature, and damage caused by heat can be prevented.

[0018]

As is clear from the above, according to the present invention, since a shape memory alloy layer having a transformation temperature lower than the guaranteed temperature of the AE sensor body is provided on the AE detection surface of the AE sensor body, the curved surface AE from a measurement object having
Detection can be performed with high transmittance through the shape memory alloy layer along this curved surface. Further, according to the present invention, after the shape memory alloy layer is once returned to its original memorized shape,
It can be deformed again and brought into close contact with the object to be measured, making it highly versatile for measuring objects having various curved surfaces. Moreover, since the transformation temperature of the shape memory alloy layer is below the guaranteed temperature of the AE sensor body, it is possible to monitor whether the ambient temperature of the AE sensor has reached a dangerous temperature.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the AE sensor of the present invention in close contact with a measurement object.

FIG. 2 is a schematic diagram of the AE sensor of the present invention.

FIG. 3 is an explanatory diagram of a conventional AE sensor.

FIG. 4 is an explanatory diagram of a conventional AE sensor.

FIG. 5 is an explanatory diagram of a conventional AE sensor.

[Explanation of symbols]

3. Object to be measured 10 AE sensor 11 AE sensor body 12 AE detection surface 13 Shape memory alloy layer

Claims (1)

[Claims] 1. An AE sensor comprising, on the AE detection surface of the AE sensor body, a shape memory alloy layer having a transformation temperature lower than the guaranteed temperature of the AE sensor body.