JPH0754854Y2 - Heat resistant probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a heat-resistant probe in the case where the thickness of a high-temperature inspected material is measured using electromagnetic ultrasonic waves.

[Conventional technology]

A non-contact type wall thickness measuring device using the electromagnetic ultrasonic method has been put into practical use. Since this device is non-contact, it is possible to measure the wall thickness of a steel material at a high temperature (for example, 700 to 1100 ° C) in a hot rolling line.

In this device, the gap between the tip surface of the detection probe and the surface of the material to be inspected has a great influence on the detection accuracy (for example, about -4 dB / mm), so the gap should normally be about 1 to 2 mm.

However, in the case of hot use, radiant heat from the material to be inspected, for example, when used to measure the wall thickness of a 800 ° C steel pipe,
If you measure about 800 lines, they will no longer be used and will need to be replaced. Since this kind of detection probe is expensive, the economic loss is extremely high.

Generally, when increasing the heat resistance of this type of detection probe,
It is possible to take measures such as (1) using a heat-resistant material for the container surrounding the detection probe, (2) cooling the container from the outside, (3) sticking a heat-resistant tape to the container, etc. To be

On the other hand, (4) JP-A-57-131048 and 57-131049
In the publication, it is proposed that the probe container has a double structure and cooling water is circulated through a coil and a case gap in front of the coil for cooling, or the case gap is evacuated to reduce the heat transfer coefficient. .

[Problems to be solved by the device]

However, even if the means of (1) above is adopted, in the case of a non-contact type wall thickness measuring apparatus utilizing the electromagnetic ultrasonic method, it is necessary to use a non-metallic material as the probe container, and for this purpose, the probe is used. Normally, plastic is used, but it cannot be used under high temperature conditions.

In the means of (2), the cooling water has a small amount of cooling water flowing around the tip surface of the detection probe, resulting in poor heat resistance.

Even if the method of (3) is adopted, it has a drawback that it lacks heat resistance and the tape is easily peeled off.

On the other hand, although the prior art example (4) seems to be excellent at first glance, by providing a case in front of the detection probe,
As described above, the distance between the tip surface of the detection probe and the surface of the material to be inspected becomes long, and as described above, there is a fundamental defect that the detection accuracy is lowered.

On the other hand, in JP-A-58-137746, a flowing water guide member is arranged on the side of the tip of the probe, and a narrow cooling water passage is formed between the flowing water guide member and the material to be inspected. An eddy current flaw detection device for hot material is disclosed in which the cooling water is filled between the probe tip and the material to be inspected by the flow resistance generated when the cooling water passes through this water passage.

However, in such an eddy current flaw detector for hot material, the cooling water is introduced between the probe tip and the inspection material by the flow resistance of the cooling water passage between the flowing water guide member and the inspection material. There is. For this reason, although cooling water is conducted between the probe tip and the inspected material, the cooling water is conducted between the probe tip and the inspected material, but the flow direction is not stable, so that the probe tip is cooled uniformly. You cannot do it. In general, it is well known that the coil portion is the most worn out by heat in the probe, and in order to improve the durability of the probe, the coil portion must be cooled surely, but such a device does not stabilize the flow direction. For,
The coil portion cannot be cooled reliably. Further, since the cooling water is difficult to be discharged due to the flow resistance of the cooling water passage formed around the probe, the circulation state of the cooling water between the probe tip and the inspection material is very poor. Therefore, the temperature of the cooling water rises between the tip of the probe and the material to be inspected due to the heat of the material to be inspected, the cooling function deteriorates and the heat resistance deteriorates, so the durability of the probe is significantly impaired.

Then, the subject of this invention is raising the heat resistance of a detection probe, and thereby raising durability, without causing a fall in detection accuracy.

[Means for Solving the Problems]

The present invention, which solves the above-mentioned problems, is a heat-resistant probe in which a detection coil and an excitation coil are provided inside and the probe tip is spaced from the surface of the material to be inspected. Each of the coils is provided in a state of forming a hole and surrounding the outflow hole when viewed from the probe tip surface side, and cooling water guided into the probe is directly directed from the outflow hole toward the surface of the material to be inspected. It is characterized by having been made to flow out.

The heat-resistant probe of the present invention is preferably used in the case of an electromagnetic ultrasonic probe as described below, but naturally it can be used with other types of probes.

[Action]

In the heat-resistant probe according to the present invention, as shown in FIG. 1, an outlet hole 10B for the cooling water W is formed at a substantially central position of the tip surface, and the outlet hole 10B is surrounded by the outlet hole 10B when viewed from the probe tip surface side. Coils 11 and 12 are provided. Therefore, the cooling water W introduced into the probe container 10 through the inflow hole 10A
Flows out from the central position in the probe tip surface through the outflow hole 10B, collides with the material M to be inspected, and then uniformly flows in the radial direction on the surface of the material M to be inspected while changing its direction. Therefore, it is possible to uniformly cool the entire probe tip surface and the entire coil portion. Furthermore, the circulation state of the cooling water W is not bad between the probe tip surface and the material M to be inspected, and the cooling water W flows smoothly in front of the coils 11 and 12, so that the cooling water W has almost no temperature. It is discharged without being raised. Therefore, since the coils 11 and 12 can be sufficiently cooled, the probe can be made excellent in heat resistance and durability.

〔Example〕

Hereinafter, the present invention will be described in more detail by way of examples with reference to FIGS. 1 to 4.

A detection probe 1 is arranged in the mounting case 2. The detection probe 1 is a plastic probe container 10
And the detection coils 11 and 12 are the basic elements. The detection coils 11 and 12 are concentric and are led out to the outside via a lead wire 13. Conversely, the detection coils 11 and 12 are excited and an eddy current is generated in the material M to be inspected, and its distribution or the like is measured. By doing so, the thickness of the material M to be inspected and the like are measured.

In the present invention, the mounting case 2 is provided with a cooling water W supply passage 2A.
And the inflow hole 10 is formed on the side surface of the probe container 10 so that the cooling water W is supplied into the detection probe 1.
A is formed. Further, an outflow hole 10B is formed at the center of the tip of the probe container 10. Further, a sealing material 3 is provided in a gap between the outer periphery of the tip of the probe 10 and the mounting case 2 so that the cooling water W is prevented from flowing out of the gap and reliably flows into the probe container 10. . on the other hand,
Since the cooling water W enters the probe container 10, each coil 11,
In order to protect the coil 12, the back surfaces of the coils 11 and 12 are made watertight by a resin molding material 14.

In the heat-resistant probe having such a configuration, the probe container 10
The cooling water W that has flowed in through the inflow hole 10A flows out through the outflow hole 10B at the center of the tip. After colliding with the material M to be inspected, the flowing-out cooling water W uniformly flows in the radial direction while changing its direction. As a result, between the tip surface of the probe container 10 and the material M to be inspected in front of the coils 11 and 12,
Since the circulating state of the cooling water W does not deteriorate and flows smoothly in the radial direction uniformly, it is possible to effectively cool the entire probe tip surface and the coils 11 and 12.

Comparative Example A probe having the structure shown in FIG. 5 was manufactured.

In this probe 1 ', the probe container 10' is hermetically sealed, the cooling water W is caused to flow out through the gap between the probe container 10 'and the mounting case 2, and the heat-resistant tape 4 is attached to the tip surface of the probe container 10'. It is a thing.

When such a probe is used, as shown in FIGS. 6 and 7, the cooling water W flowing out from the gap flows mainly in the radial direction, and the flow toward the front surface of the probe container 10 'is extremely small. .

(Comparison result) When using the probe 1'shown in FIG. 5 to measure the wall thickness of a steel pipe at 800 ° C. on a hot line, if about 500 pieces are measured, it cannot withstand the subsequent use. It became a thing and needed exchange.

On the other hand, when the heat-resistant probe shown in FIGS. 1 and 2 according to the present invention is used, under the same conditions until now
No damage due to radiant heat is observed even after measuring 3000 lines.

[Effect of device]

As described above, according to the present invention, it is possible to enhance the heat resistance of the detection probe and thus the durability without lowering the detection accuracy.

[Brief description of drawings]

FIG. 1 is a view taken along the line II of FIG. 2, FIG. 2 is a perspective view of a probe, FIGS. 3 and 4 are perspective views illustrating the flow of cooling water according to the present invention example, and FIG. 5 is a comparative example. 6 and 7 are explanatory perspective views of the flow of cooling water in the case of the comparative example. 1 ... Heat-resistant probe, 2 ... Mounting case, 3 ... Sealing material, 10 ... Probe container, 10A ... Inflow hole, 10B ... Outflow hole, 11, 12 ... Coil, W ... Cooling water, M …… Inspected material.

Claims (1)

[Scope of utility model registration request] 1. A heat-resistant probe having a detection coil and an excitation coil provided therein, wherein the probe tip is spaced from the surface of the material to be inspected, and an outflow hole is formed at approximately the center of the probe tip surface. The coils are provided so as to surround the outflow hole as viewed from the probe tip surface side, so that the cooling water guided into the probe directly flows out from the outflow hole toward the surface of the inspection material. A heat-resistant probe characterized in that