JP2001235456A - Local submerged jig for ultrasonic wave - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly supply a necessary and sufficient amount of a contact medium (water) to a gap between the bottom face of a probe and the outer surface of a material to be inspected, in the case where flaw of the material to be inspected is detected by using a local submerged ultrasonic probe. SOLUTION: The local submerged jig for detecting flaw of the ultrasonic probe while water is injected into the gap with the material to be inspected, is composed of a frame body in which the probe is inserted to be fixed on the outside of the lower end and a water supply passage supplying water to the gap is provided, and a material with an elastic skirt arranged by providing the space downward of the lower face of the frame body, fixing the outside end edge on the frame body by making a free end bringing the inside end edge into contact with the material to be inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a local immersion type ultrasonic flaw detector, and when a local water immersion type ultrasonic probe automatically scans an outer surface of a material to be inspected, a probe is used. The required amount of the contact medium (water) can be supplied smoothly and sufficiently to the gap between the bottom surface of the test piece and the outer surface of the material to be inspected. The present invention relates to a local water immersion jig for an ultrasonic probe capable of continuously detecting a defect with higher precision even when a large probe having a large size is used.

[0002]

2. Description of the Related Art Ultrasonic flaw detection by a local immersion method has a thickness of 1 mm.
It is widely used as a method for inspecting the presence or absence of internal defects in a steel material of 3 mm or more. Specifically, JIS G0801-
1974, JISZ2344-173, and the like.

FIG. 3 shows an example of a local immersion type ultrasonic probe used in the above-mentioned local immersion type ultrasonic flaw detection, in which 1 is a probe, and 2 is a probe housing. , 7 are joints, 8 is a water supply pipe, 9 is a material to be inspected, 12 is a water supply groove, 1
3 is a water film, 14 is a probe holder, 15 is a lead wire, 1
6 is an XY scanner, and 17 is a Z scanner.

A probe housing 2 for storing the probe
A water supply groove 12 having a substantially square cross section is formed in a loop shape on the lower end surface 2b of the water supply pipe 8 and the water W serving as a contact medium supplied through the supply passage 2a. The water film 13 having an appropriate thickness is formed by being supplied to the gap between the front surface 9a and the probe bottom surface 1a.

The thickness L of the water film 13 depends on the probe bottom surface 1a.
Shape / dimension, scanning speed, inspection material outer surface 9
The thickness is usually set to 3 to 15 mm in accordance with the state of a, and the supply pressure and the supply flow rate of the water W are controlled so that the water film 13 having the thickness L is formed. ~ 1.0
L / min of water W is supplied.

In FIG. 3, the water supply groove 12 is formed in a loop shape on the lower end surface 2b of the probe housing 2 for storing the probe 1, as shown in FIG. As described above, the water supply groove 12 is provided in a loop shape on the lower end surface 3a of the separately formed cylindrical frame 3, and the frame 3 is fixed to the outer surface of the lower end of the probe housing 2. The ultrasonic probe for local water immersion has been widely used for some time. This is because the processing of the water supply groove 12 becomes easier when the frame 3 is formed as a separate body.

In the case of a local water immersion type ultrasonic flaw detection for performing flaw detection while flowing water from the water supply groove 12,
During the measurement, the ultrasonic wave propagation range from the probe bottom surface 1a to the inspection target material outer surface 9a is completely filled with the water W as the propagation medium, and the probe bottom surface 1a and the inspection target material outer surface 9a Are constant, and the absence of foreign matter such as air bubbles in the water W as the contact medium or on the outer surface 9a of the material 9 to be inspected are indispensable requirements for increasing the flaw detection accuracy. . If these requirements are not satisfied, the ultrasonic echo may not return to the material to be inspected 9 and return as a reflected echo on the way, or information on the position to be measured may not be obtained.

Therefore, the flow rate of the water W to be supplied and the gap L between the probe bottom surface 1a and the outer surface 9a of the inspection target material need to be particularly strictly controlled during the measurement.
If the gap L can be accurately managed by increasing the parallelism of the scanner and the smoothness of the outer surface 9a of the material to be inspected, the local water immersion ultrasonic testing has excellent practical utility.

However, there are still many problems to be solved in the local water immersion type ultrasonic flaw detection. In particular, when a large probe 1 is used, a necessary amount of water W (ie, Water film 1
There is an urgent need to solve the problem that 3) is difficult to secure in the gap between the probe bottom surface 1a and the inspection object outer surface 9a. That is, if the size of the probe bottom surface 1a is up to about 60 mm × 60 mm, the thickness L of the water film 13 can be relatively easily adjusted over the entire surface of the probe bottom surface 1a to a uniform thickness of about 5 to 15 mm. Can be held.

However, the size of the probe bottom surface 1a is about 10
In the case of the large probe 1 exceeding 0 mm × 100 mm, the water W does not sufficiently spread over the entire surface of the probe bottom surface 1 a, and not only the thickness L of the water film 13 becomes non-uniform, but also the water film 13 Even a portion having no defect is generated, and it becomes difficult to perform high-precision flaw detection. Further, the amount of water leaking to the outside from the gap between the lower end surface 2a of the probe housing and the lower end surface 3b of the frame body increases, so that a large amount of water W is required and the thickness of the water film 13 is adjusted by adjusting the water supply pressure and the water supply amount. Control becomes difficult.

[0011]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem in the conventional local water immersion type ultrasonic flaw detection, that is, when a large probe 1 is used, water W is sufficiently supplied to the probe bottom surface 1a. When the outer surface 9a of the material to be inspected has many irregularities, it is possible to perform high-precision flaw detection, and the amount of water leaking from the gap between the lower end surface 2a of the housing increases, so that the water consumption increases and the water film increases. It is intended to solve problems such as difficulty in controlling the thickness of the probe 13. Even when the large probe 1 is used, or when the inspection material 9 has many irregularities on the outer surface 9 a, the probe An object of the present invention is to provide a local water immersion jig for an ultrasonic probe which can secure a sufficient amount of water W on the bottom surface 1a and can always perform high-precision and stable flaw detection.

[0012]

According to the first aspect of the present invention, there is provided a local water immersion jig of an ultrasonic probe for detecting a flaw while injecting water as a contact medium into a gap between the material and the inspection object. A frame body provided with a supply passage for water to be supplied to the gap, and a space provided below a lower surface of the frame body, the frame body being fixed to an outer surface of a lower end portion of the contactor and being fixed to an outer surface of the lower end portion; The basic structure of the present invention is that the skirt is made of an elastic material having an edge fixed to the frame and an inner edge being a free end contacting the material to be inspected.

According to a second aspect of the present invention, in the first aspect of the invention, a flat cylindrical elastic body having a water hole for supplying water to a space above the skirt material is interposed on the lower surface of the frame. It was done.

According to a third aspect of the present invention, in the first aspect, the outer edge of the skirt member is fixed to the outer surface of the frame.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the skirt member is formed as a square flange-shaped integrally formed product, and its thickness is gradually reduced inward.

When the weight of the probe 1 or the like is increased, the back surface 5a of the skirt material 5 covering the outer periphery of the probe housing 2 is airtight to the outer surface 9a of the material 9 to be inspected due to the elasticity of the skirt material itself. Pressed into a shape. Water W as a contact medium
Is injected at a predetermined pressure into a space 5c above the skirt material 5, and the injected water W enters a gap between the probe bottom surface 1a and the inspection object outer surface 9a. Since the back surface 5a of the skirt material is in close contact with the outer surface 9a of the material to be inspected with a predetermined elastic force, relatively little water W leaks from the gap on the back surface 5a of the skirt material. As a result, by appropriately adjusting the water injection pressure and the water injection flow rate, the probe 1 is lifted by a predetermined distance L like a hovercraft by the pressure of the injected water.

When the probe 1 is attached to an XY scanner or the like for flaw detection, the distance L is set to a predetermined value in advance on the scanner side. When the probe 1 is moved manually or by another driving source without using an XY scanner or the like, the probe 1 is moved at a predetermined speed along the inspection object outer surface 9a. During the flaw detection, the water W is continuously supplied at a predetermined pressure, thereby replenishing the leaked water amount.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a local water immersion jig for an ultrasonic probe according to the present invention, and FIG. 2 is a sectional view taken along the line イ ー in FIG. In FIGS. 1 and 2, members common to FIGS. 3 and 4 are denoted by the same reference numerals.

1 and 2, A is a local water immersion type ultrasonic flaw detector, B is a local water immersion jig for an ultrasonic probe, W is a contact medium (water), and 1 is a probe. 2 is a probe housing,
3 is a cylindrical frame, 4 is a flat elastic body, 5 is a skirt material, 6
Is a fixture, 7 is a joint, 8 is a water supply pipe, 9 is a material to be inspected,
10 is a mounting screw hole, 11 is a support piece, and the local water immersion jig B for an ultrasonic probe according to the present invention is a frame 3, a flat elastic body 4, a skirt material 5, a fixture 6, a joint 7 and the like.

The cylindrical frame 3 is formed in a square shape by a steel material having a substantially square cross section. The probe housing 2 containing the probe 1 is inserted into the frame 3 and a fixing screw (not shown) screwed into the mounting screw hole 10 is tightened, so that the probe 1 is moved to the frame. 3 and fixed. Also,
As shown in FIG. 2, a water supply passage 3a is bored in the frame 3, and a joint 8 of a water supply pipe 7 is fixed to an upper surface thereof.

The flat elastic body 4 is a flat hose body formed in a loop shape by a so-called elastic material.
Is disposed on the lower surface 3b side of the. The upper surface side 4c of the elastic body 4 is air-tightly fixed to the frame body lower surface 3b. Also,
The flat elastic body 4 is provided with water passage holes 4a, 4a 'at a portion facing the water supply passage 3a, and water W of the flat elastic body 4 passes through the water passage holes 4a, 4a'. It is supplied to the inside and the upper space 5c of the upper surface 5b of the skirt material. Further, the outer edge of the flat elastic body 4 is made of a skirt material 5 described later.
Are supported and fixed to the outer side surface of the frame 3 via the fixing bracket 6 together with the outer edge of the frame 3.

In the embodiment shown in FIGS. 1 and 2, a flat hose having elasticity and bent into a square loop is used as the elastic body 4, but the shape of the elastic body 4 is not limited. Any shape may be used as long as it has an appropriate cushioning effect. Although the flat elastic body 4 is used in the embodiment shown in FIGS. 1 and 2, the elastic body 4 can be omitted.

The skirt member 5 is integrally formed in a rectangular flange shape by using a thin synthetic resin plate having elasticity or a laminated plate of synthetic resin and woven fabric, and has a so-called sled shape in cross section. Have been. The skirt material 5 is disposed so as to form a space 5c of a predetermined size on the skirt material upper surface 5b side, and its outer edge is supported and fixed to the outer surface of the frame 3 via a fixing bracket 6. Have been. Further, the tip side (inner tip) of the skirt material 5 is a free end, and is in contact with the outer surface 9a of the material 9 to be inspected at a predetermined pressure.

In this embodiment, the skirt material 5 is used.
Is formed as a single piece by molding or die-cutting into a square flange shape, but it may be formed into a square flange shape by combining a plurality of skirt pieces. Also, the cross-sectional shape of the skirt material 5 is the inner tip edge (probe bottom surface 1a side).
It is formed so that its thickness becomes thinner as it goes.

As described above, when the weight of the probe 1 and the like is applied, the back surface 5a of the skirt member 5 covering the outer periphery of the probe housing 2 is airtightly sealed to the outer surface 9a of the material to be inspected due to its elasticity. Pressed to. The supplied water W as a contact medium is injected into the upper space 5c of the skirt material 5 with a predetermined pressure, and the injected water W flows into a gap between the probe bottom surface 1a and the inspection object outer surface 9a. Get in. Since the back surface 5a of the skirt material 5 is in close contact with the outer surface 9a of the material to be inspected with a predetermined pressure, relatively little water leaks from the gap between the back surface 5a of the skirt material and the outer surface 9a of the material to be inspected. as a result,
By appropriately adjusting the water injection pressure and the water injection flow rate, the probe 1 is lifted by a predetermined distance L like a hovercraft by the pressure of the injected water W, and is moved in a predetermined direction in this state. Will be.

[0026]

According to the present invention, the probe housing 2 is provided.
A skirt member 5 made of an elastic material is disposed below the lower surface 3b of the cylindrical frame body 3 fixed to the outer periphery at the lower end of the skirt member 5 with a space 5c therebetween, and the inner edge of the skirt member 5 is set as a free end. At the same time, the outer edge is fixed to the frame 3, and the water W supplied through the supply passage 3a provided in the frame 3 is injected from the space 5c below the probe bottom surface 1a. as a result,
The water W supplied to the upper space 5c of the skirt material 5 is pressed into the gap between the probe 1 and the material 9 to be inspected very smoothly without leaking to the outside. Even in the case of the probe 1 or the case where the outer surface 9a of the inspection object has a large number of irregularities, it is possible to sufficiently secure the water serving as the contact medium in the gap, and to achieve high precision. Ultrasonic flaw detection becomes possible. Further, since the amount of water leaking from the gap to the outside is reduced, the gap size (that is, the thickness L of the water film 13) can be easily controlled by adjusting the water supply pressure and the water supply flow rate. This is particularly advantageous when doing so. As described above, the present invention has excellent practical utility irrespective of a simple configuration.

[Brief description of the drawings]

FIG. 1 is a perspective view of a local water immersion jig for an ultrasonic probe according to the present invention.

FIG. 2 is a schematic sectional view taken along line II in FIG.

FIG. 3 shows an example of a conventional local water immersion ultrasonic probe.

FIG. 4 shows an example of a conventional local immersion jig for an ultrasonic probe.

[Explanation of symbols]

A is a local water immersion type ultrasonic flaw detector, B is a local water immersion jig for an ultrasonic probe, W is a contact medium (water), L is a gap size, 1 is a probe, and 2 is a probe housing. 3 is a cylindrical frame, 3a is a water supply passage, 3b is a lower surface, 4 is a flat cylindrical elastic body, 4a
4a 'is a water passage hole, 4b is a lower surface side, 4c is an upper surface side, 5 is a skirt material, 5a is a skirt back surface, 5b is a skirt upper surface, 5c is a space, 6 is a fixing bracket, 7 is a joint, 8 is a water supply. A pipe, 9 is a material to be inspected, 9a is an outer surface of the material to be inspected, 10 is a screw hole for mounting a local water immersion jig, 11 is a support piece of the local water immersion jig, 12 is a water supply groove, and 13 is a water film. , 14 is a probe holder, 15 is a lead wire, 16 is an XY scanner, and 17 is a Z scanner.

Claims (4)

[Claims] 1. A local water immersion jig for an ultrasonic probe which performs flaw detection while injecting water as a contact medium into a gap between the probe and a material to be inspected. A frame provided with a supply passage for water to be supplied to the gap, and a space provided below a lower surface of the frame, the outer edge of which is fixed to the frame and the inner edge of which is fixed. And a skirt member made of an elastic material having a free end in contact with a material to be inspected. 2. The ultrasonic probe local part according to claim 1, wherein a flat cylindrical elastic body having a water hole for supplying water to a space above the skirt material is interposed on a lower surface of the frame body. Water immersion jig. 3. The ultrasonic probe local water immersion tool according to claim 1, wherein the outer edge of the skirt material is fixed to the outer surface of the frame. 4. The local water immersion jig for an ultrasonic probe according to claim 1, wherein the skirt material is formed as a square flange-shaped integrally formed product, and the thickness thereof is gradually reduced inward.