JPS62145163A - Probe for high temperature - Google Patents

Abstract

PURPOSE:To obtain a probe generating no peeling between a vibrator and a case, even in case a differential thermal expansion of the vibrator and the case is large, by providing a slit in advance in the vibrator. CONSTITUTION:A probe is formed by enclosing a vibrator 3 provided with a slit 6, into a closed container consisting of a case 1 and an upper cover 2, and when transmitting and receiving an ultrasonic wave, a high temperature use cable 7 is used. The vibrator 3 and the case 1 are joined by a high temperature use adhesive layer 5. At the time of transmission, an electric signal is applied between an electrode 4 and the case 1, a distortion is generated in the vibrator 1, and this distortion goes to a pressure wave and propagated to the outside from the bottom face of the case 1. At the time of reception, a signal by the distortion of the vibrator 1 is obtained as an electric signal between the electrode 4 and the case 1. Since the slit 6 is provided in the disk- shaped vibrator 3, even if a stress caused by a differential thermal expansion is applied to the vibrator 3 and the case 1, the slit 6 progresses in the thickness direction or penetrates to the upper part and releases the stress, before a junction layer 5 peels off.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a probe used for ultrasonic flaw detection and the like.

In particular, the present invention relates to a high-temperature probe that can be used even when the object to be tested is at a high temperature.

[Background of the invention]

In the conventional high-temperature probe, as described in Japanese Patent Publication No. 853-3017, the vibrator and case were bonded together by baking with silver. However, in this type of high temperature probe, it is necessary that the bonding state does not change over a wide temperature range from room temperature to the operating temperature of 300 C or higher. With conventional methods, if there is a large difference in thermal expansion between the case and the transducer, the force generated by the difference in expansion may cause the transducer and case to separate, or the sensor may be damaged, resulting in a significant decrease in probe sensitivity. Therefore, the object of the present invention is to prevent delamination between the vibrator and the case even when the difference in thermal expansion between the vibrator and the case is large. The object of the present invention is to obtain a high-temperature probe with a structure that does not cause heat generation.

[Summary of the invention]

In order to achieve this objective, in the present invention, a slit is made in the camera element in advance.

When the difference in thermal expansion is large, K causes stress concentration to occur in the slit, causing the slit portion to break.

With this thorough approach, there is no separation between the case through which ultrasound waves pass and the camera element. A crack will appear in the slit portion of the camera element, but if the slit e is crimped so that the crack enters in a direction that does not interfere with the vibration of the camera element, no large sensitivity change will occur.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows a groove path of a high temperature probe for transmitting and receiving longitudinal ultrasonic waves according to the present invention. The probe has the camera element 3 with the slit 6 fully inserted in the case 1. It is enclosed in an airtight container consisting of a top lid 2, and a cable 7 for the upper part is used for transmitting and receiving ultrasonic waves. The camera element 3 and the case 1 are bonded together by a high-temperature adhesive layer 5.

When transmitting ultrasonic waves, an electrical signal with a desired waveform is applied to the t pole 4 and the case 11 river to generate vibration IK mechanical distortion, and this mechanical distortion becomes a pressure wave that propagates to the outside from the case 1 pregnancy surface. . When receiving ultrasonic waves, the signal generated by the mechanical distortion of the transducer 1 is obtained as an electrical signal between the FM 4 and the case 1, so this is guided by the high temperature cable 7 and connected to the onoroscope, etc. can. Here, the degree of bonding between the vibrator 3 and the case 1 is closely related to the sensitivity of the probe.

If the bonding is not sufficient, the high-temperature adhesive layer 5 will contain air bubbles, and the progress of ultrasonic waves will be blocked between the vibrator 3 and the case 1. If the opposite is true, the space between the transducer 3 and the case 1 will be filled with enough high-temperature adhesive layer 5, and since the high-temperature adhesive layer 5 is thin, the progress of the ultrasonic waves will not be hindered, allowing high-sensitivity detection. Becomes a tentacle.

Good sensitivity of the probe means that transducer 3 and case 1
This means that the bonding condition is good. On the other hand, if the bonding condition is good, there is no escape route for the stress caused by the difference in thermal expansion, so depending on the selection of materials for the vibrator 3 and case l, peeling of the adhesive layer or destruction of the vibrator may occur. It means that there is a gender. In order to prevent this, in the probe of the present invention, a slit 6 is provided in the vibrator 3. FIG. 2 shows the bottom of the probe of the present invention.

A dice-shaped slit 6 is inserted into the disc-shaped camera element 3. Even if the stress caused by the difference in thermal expansion between the camera element 3 and the case IK is applied, the slit 6
develops in the thickness direction or penetrates to the top to release stress. Therefore, <* does not occur in the adhesive layer 5. Also,
What about cracks in vibrator 3?

The main VC expands in the thickness direction guided by Surin) 6,
The sensitivity of imaging due to the thickness of the vibrator 3 itself does not deteriorate significantly.

The high-temperature probe of the present invention has a case], an upper lid 2 made of stainless steel, a vibrator 3 made of lithium niobate single crystal, and a high-temperature cable 7 made of stainless steel and a nickel-core MI cable. As the high temperature adhesive layer 5, a polyimide adhesive is used. The present invention is not limited to 5r% of these materials. In addition, we use high-cure-point vibrators such as lead meta-7obate, bismuth-stronotium titanium titanate/acid, and iron-cobalt alloys, and as adhesives, we use resistant materials such as silver or gold with a binder added. For high-temperature adhesives and cases, there are heat-resistant materials such as nickel and Inoconel.

The following effects are unique to this embodiment.

(1) The slit 6 of the vibrator 3 acts as a gas exhaust hole to release the gasified binder when the adhesive hardens.
When the case 1 and the vibrator 3 are bonded, no air bubbles remain in the adhesive wI, making it possible to increase the sensitivity of the probe, which has the effect of improving the performance of the probe.

(2) Compared to the case of combining and bonding vibrators that have been finely chopped in advance, the bonding work is easier and the manufacturing cost is reduced.

〔Effect of the invention〕

As described above, according to the present invention, the difference in thermal expansion between the camera element and the case does not become a problem when the probe is bent, so there is no restriction on the camera element to be used, and the performance of the probe is improved. There is an effect.

[Brief explanation of drawings]

FIG. 1 is a side view of a probe according to an embodiment of the present invention, and FIG. 2 is a plan view of an imager used in the present invention. 1... Case, 2... Upper lid, 3... Perturber 14.
...Electrode, 5゛...Adhesive layer, 6...Slit, 7...
・Cable for high τ seats.

Claims (1)

[Claims] 1. A high-temperature probe in which the slitted surface of a piezoelectric, electrostrictive, or magnetostrictive vibrator having slits in the thickness direction is joined to the acoustic emission surface of a sealed container that houses the vibrator.