JP2012177682A - Water seal type probe holding device and inspection method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an amount of water to be supplied between an ultrasonic probe and the surface of an inspection object and to prevent interference of air bubbles which becomes an obstacle in an inspection of the inspection object in ultrasonic measurement by a local water immersion method.SOLUTION: A water seal pad 12 consisting of an annular elastic member is closely adhered to the surface of an inspection object 1 by pressing a water seal type probe holding device 10 to the inspection object 1, water to be supplied from the outside is introduced inside the water seal pad 12 by a water supply path 11a, and measurement by a probe 2 is performed in a state where the water introduced inside is accumulated in a cylindrical housing 18 at a lower part along the side of the ultrasonic probe 2.

Description

  The present invention relates to an apparatus for holding a sealed probe used when measuring the thickness of a steel plate or a steel pipe by a local water immersion method, and a method for inspecting an object to be inspected using the apparatus.

  As a method for inspecting corrosion or thinning of a steel plate or a steel pipe, ultrasonic thickness measurement is known. Devices that do this automatically have been developed, but in many cases, a local water immersion method is used.

  In this ultrasonic measurement apparatus based on the local water immersion method, measurement is performed by forming a water film by supplying water to the gap between the ultrasonic probe and the object to be inspected. For this reason, water must be constantly supplied during measurement, and the amount of water consumption increases as the inspection target increases. In addition, the thickness of the water film is set according to the bottom surface dimension of the probe, the scanning speed, the surface condition of the object to be inspected, and the like so that the water film of that thickness is stably formed. It is necessary to control the pressure and flow rate (see Patent Document 1).

  Therefore, for example, when performing an ultrasonic inspection automatically in a place where it is difficult to supply water, such as when checking the thickness of a water supply pipe installed in a mountain, the water used during the inspection should be It must be transported by hand. However, when the amount of water to be used is large, the amount of water to be transported becomes large and the burden on the transporter increases. Therefore, it is desired to reduce the amount of water consumed.

  Moreover, the inside of the device holding such a probe is filled with water. For this reason, it is necessary to bring the holding device into close contact with the surface of the object to be inspected so that the supplied water does not leak outside.

Japanese Patent No. 4353604

  However, if water is supplied into the holding device in a close contact state, bubbles tend to accumulate inside the holding device, and this bubbles affects the propagation of ultrasonic waves and makes it difficult to perform accurate measurement. In particular, when the surface of the object to be inspected is horizontal, such as a horizontally extending steel pipe, bubbles tend to stay near the bottom surface of the ultrasonic probe facing the surface. For this reason, there is a problem that high-precision measurement or inspection becomes difficult.

  Therefore, the object of the present invention is to reduce the consumption of water necessary for forming a water film between the ultrasonic probe and the surface of the object to be inspected in ultrasonic measurement by the local water immersion method. It is an object to provide a sealed-type probe holding device that can prevent the interference of bubbles that become obstacles when inspecting an object to be inspected, and an inspection method using a probe using the same.

  A sealed-type probe holding device of the present invention includes a probe holding member that holds an ultrasonic probe so as to take a gap between the surface of the object to be inspected and the ultrasonic probe at the time of measurement, A sealing pad made of an annular elastic material that surrounds the lower end of the probe held by the holding member and closes the gap by being in close contact with the surface of the object to be inspected, and from the inside of the sealing pad A cylindrical housing disposed so as to open in the gap, and a water supply path for introducing water into the sealed pad from the outside of the probe holding member.

  The method of the present invention is a method for inspecting an object to be inspected by a probe using the sealed probe holding device having the above-described structure, and a sealing pad by pressing the holding device against the object to be inspected In close contact with the surface of the object to be inspected, water supplied from an external water supply source is introduced into the sealing pad through the water supply channel, and the water introduced into the inside of the sealing pad is introduced into the side surface of the ultrasonic probe. The measurement by the probe is performed in a state where the probe is stored in the cylindrical housing below.

  According to the apparatus of the present invention or the inspection method using the same, it is possible to measure the thickness by ultrasonic waves using a local water immersion type probe without controlling the water supply pressure and flow rate during the inspection. Also, water consumption can be much reduced compared to continuous water supply during measurement.

  Further, by providing the cylindrical housing inside the apparatus, it is possible to suppress the interference of bubbles generated inside, and it is possible to realize stable measurement without degrading accuracy.

  In addition, since the periphery of the ultrasonic probe is covered with a sealing pad, the probe can be protected against external protrusions and the like.

  Furthermore, since the contact surface between the sealing pad and the surface of the object to be inspected is formed of a water film, the frictional resistance between the contact surfaces of both is reduced.

  In the present invention, the probe holding member is formed into a vertically long cylindrical shape by inserting and fixing the lower portion of the upper cylindrical member into the upper portion of the lower cylindrical member, and the ultrasonic wave is formed inside the probe holding member. It is preferable to hold the probe. According to this, even if a tensile force is applied to the ultrasonic probe, the ultrasonic probe can be prevented from being tilted.

  Moreover, it is preferable to provide a drainage channel that leads from the inside of the sealing pad to the outside of the probe holding member. According to this, since the bubbles generated inside the cylindrical housing are discharged through the drainage channel from the lower end of the cylindrical housing, interference of the bubbles generated inside can be further suppressed.

Sectional drawing which shows the structure of the sealed probe holding device of 1st Embodiment. The figure which shows the use condition of the sealed-type probe holding | maintenance apparatus of 1st Embodiment. Sectional drawing which shows the structure of the sealed probe holding device of 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described.

[First embodiment]
A sealed-type probe holding device 10 shown in FIG. 1 holds a bar-shaped ultrasonic probe 2 perpendicular to the surface of a test object 1 such as a steel pipe, and is superposed with the surface of the test object 1. In order to supply water between the bottom surface of the acoustic probe 2, a flat cylindrical probe holding member 11 for inserting and holding the lower portion of the ultrasonic probe 2, and the probe 2 A sealing pad 12 made of an annular elastic material (for example, a synthetic rubber material) surrounding the lower end and forming a gap 3 sealed between the bottom surface 2a of the probe 2 and the surface of the object 1; A pad fixing tool 13 disposed between the child holding member 11 and the sealing pad 12, an annular pad pressing tool 14 disposed inside the bottom surface of the sealing pad 12, and an opening below the pad fixing tool 13. A bolt 15 that passes through the sealing pad 12 and is coupled to a screw hole of the pad presser 14 and a water supply source (not shown) It is constituted by a water supply pipe 16 to be introduced into the water supply passage 11a which communicates with the interior of the seal water pad 12 from the water side of the probe holding member 11 probe put from the upper end of the water inlet 16a to be sent from.

  Here, a probe cable 2b that electrically connects an internal circuit of the ultrasonic probe 2 and an external device extends from the upper end of the probe 2 to the outside.

  In addition, in order to adjust the distance between the ultrasound probe 2 and the object 1 to be inspected according to the thickness of the object 1 to be inspected, a step in which the diameter of the lower part of the ultrasound probe 2 is reduced. An annular spacer 17 can be disposed between the portion and the probe holding member 11.

  Moreover, in this embodiment, the cylindrical housing 18 is integrally formed below the inner surface of the pad presser 14 disposed inside the bottom surface of the sealing pad 12.

  When the inspection object 1 is inspected, the sealing pad 12 is inspected by pressing the holding device 10 holding the lower end portion of the ultrasonic probe 2 against the inspection object 1 using, for example, a cylinder mechanism. It adheres to the surface of the body 1. As a result, the water 4 is accumulated in the sealed gap 3 inside the sealing pad 12 so that the inspection by the ultrasonic probe 2 can be performed.

  Here, the water supplied from the external water supply source and flowing into the water supply port 16 a is introduced from the water supply pipe 16 through the water supply path 11 a into the sealing pad 12 and stored in the cylindrical housing 18. Thereby, the gap 3 between the probe 2 and the surface of the inspection object 1 can be filled with the water 4, and a certain amount of water can be sealed under pressure. Therefore, it is not necessary to constantly supply water, and the amount of water consumption can be reduced.

  In addition, the water supplied through the water supply channel 11a flows from the side of the ultrasonic probe 2 along the side surface thereof into the gap 3 below the probe 2, thereby reducing the generation of bubbles, Bubbles generated inside are pushed outward from the lower end of the cylindrical housing 18. Thereby, it is possible to minimize the interference of bubbles during measurement.

  Further, since the periphery of the ultrasonic probe 2 is covered with the sealing pad 12, it is avoided that the bottom surface of the probe 2 directly hits a solid substance or an external projection attached to the surface of the object to be inspected. Thus, the probe 2 can be protected.

  Further, since the surface of the device under test 1 and the opposite surface of the sealing pad 12 are covered with water 4, there is also an advantage that the frictional resistance between both surfaces is reduced.

  When performing automatic measurement using the probe holding device of the present embodiment, the probe holding device 10 is supported by the slide table 21 via the fixture 20, as shown in FIG. Attached to the air cylinder mechanism 22. Specifically, the mounting tool 20 is composed of a vertically extending member that is coupled to the pad fixing tool 13 of the holding device 10, and is mounted on the movable portion 23 that moves in the vertical direction in the drawing by the operation of the air cylinder.

  Further, in order to deal with the unevenness of the surface of the device under test 1 during measurement, the holding device 10 is attached to the fixture 20 so as to be movable up and down, and two or more are provided between the lower end of the fixture 20 and the pad fixture 13. It is preferable to install the coil spring 24.

  Furthermore, it is preferable to provide a plurality of rollers 25 that can rotate in the left-right direction in the figure at both ends of the bottom surface of the pad fixture 13 of the holding device 10. According to this, at the time of measurement, each roller 25 comes into contact with the surface of the device under test 1, thereby assisting the holding device 10 to move along the surface of the device under test 1 and holding it by the air cylinder mechanism 22. It is possible to prevent the device 10 from being excessively pressed against the device under test 1.

[Second Embodiment]
FIG. 3 shows the sealed probe holding device 30 of the second embodiment. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals. The present embodiment has a different configuration from the above-described first embodiment in the following points.

  In the first embodiment, the lower part of the ultrasonic probe 2 is inserted into the flat cylindrical probe holding member 11 to hold the ultrasonic probe 2, but only the holding member 11 having this shape is used. Then, when a large tensile force is applied to the probe cable 2b, the ultrasonic probe 2 is inclined. Then, if the ultrasonic probe 2 is tilted during measurement, there is a possibility that precise measurement cannot be performed.

  Therefore, in order to improve the holding property of the ultrasonic probe, in the second embodiment, the probe holding member is composed of two upper and lower cylindrical members 31 and 32 as shown in FIG. It is formed as a socket type (nested type) structure in which the lower part of the upper cylindrical member 31 is inserted and fixed to the upper part of the shape member 32.

  That is, the two cylindrical members 31 and 32 constituting the probe holding member both have an inner diameter that allows the ultrasonic probe 2 to be inserted and held, while the lower portion of the upper cylindrical member 31 It is formed as a small-diameter portion having a small diameter, and the upper portion of the lower cylindrical member 32 is formed as a large-diameter portion having an inner diameter that allows the lower portion of the upper cylindrical member 31 to be inserted and fitted.

  Therefore, in the present embodiment, the probe holding member is formed into a vertically long cylindrical shape by inserting the lower portion of the upper cylindrical member 31 into the upper portion of the lower cylindrical member 32, and the entire length is formed inside the probe holding member. The ultrasonic probe 2 is held. The connecting portion between the two cylindrical members 31 and 32 has four set screws 33 radially from the upper outer peripheral surface of the lower cylindrical member 32 at an angular interval of 90 ° on the circumference of the cross section. By screwing in, the two members 31 and 32 are fixed so as not to be separated.

  Since the entire main part of the ultrasonic probe 2 is held by the socket-type probe holding member, the ultrasonic probe 2 is inclined when a tensile force is applied to the probe cable 2b. Can be prevented.

  Furthermore, in the present embodiment, in order to hold the ultrasonic probe 2 inserted into the probe holding member more firmly, the upper and lower parts of the upper cylindrical member 31 are each 90 on the circumference of the cross section. The ultrasonic probe 2 is fixed by screwing four set screws 33 radially from the outer peripheral surface at an angular interval of °.

  Next, in the first embodiment, air bubbles are prevented from interfering during measurement using only the cylindrical housing 18, but in the sealed probe holding device of the second embodiment, the air bubbles are further interfered. In order to reduce this, a drainage channel that leads from the inside of the sealing pad to the outside of the probe holding member is added.

  That is, as shown in FIG. 3, the pad retainer 14, the sealing pad 12, the pad fixture 13, and the lower part of the probe holding member are formed from the inside of the sealing pad 12 outside the cylindrical housing 18. A drain pipe 19 that extends through the cylindrical member 32 and forms a drain passage 11 b that extends from the side surface of the cylindrical member 32 to the outside is extended. Accordingly, bubbles generated inside the cylindrical housing 18 are discharged from the lower end of the cylindrical housing 18 to the outside through the drainage channel 11b.

  A check valve 34 is attached to the tip of the drain pipe 19. Thereby, the backflow of the air from the drainage channel 11b to the inside of the sealing pad 12 can be prevented.

  Specifically, as in the first embodiment, the water that has flowed in from the water supply pipe 16 travels along the side surface of the probe 2 and fills the cylindrical housing 18 and the sealing pad 12. At this time, bubbles generated inside are discharged from the drain pipe 19 through the drainage channel 11b. Further, the check valve 34 attached to the drain pipe 19 prevents the inflow of air (back flow).

  Although the illustrated embodiments have been described above, the present invention is not limited to these embodiments.

DESCRIPTION OF SYMBOLS 1 ... Test object, 2 ... Ultrasonic probe, 3 ... Gap, 4 ... Water, 10 ... Probe holding device, 11 ... Probe holding member, DESCRIPTION OF SYMBOLS 11a ... Water supply channel, 11b ... Drainage channel, 12 ... Sealing pad, 13 ... Pad fixing tool, 14 ... Pad presser, 15 ... Bolt, 16 ... Water supply pipe 17 ... Spacer, 18 ... Cylindrical housing, 19 ... Drain pipe, 20 ... Fixture, 21 ... Slide table, 22 ... Air cylinder mechanism, 23 ... Movable part 24 ... Coil spring, 25 ... Roller, 30 ... Probe holding device, 31, 32 ... Probe holding member, 33 ... Set screw, 34 ... Check valve.

Claims (4)

A probe holding member that holds the ultrasonic probe so that a gap is formed between the surface of the object to be inspected and the ultrasonic probe during measurement;
A sealing pad made of an annular elastic material that surrounds the lower end of the probe held by the holding member and is in close contact with the surface of the object to be inspected to seal the gap;
A cylindrical housing arranged to open into the gap from the inside of the sealing pad;
A sealed-type probe holding device comprising: a water supply path for introducing water into the sealed pad from the outside of the probe holding member.   2. The sealed probe holding device according to claim 1, wherein the probe holding member is a vertically long cylinder by inserting and fixing a lower portion of an upper cylindrical member into an upper portion of a lower cylindrical member. A sealed-type probe holding device formed into a shape and holding the ultrasonic probe therein.   The sealed-type probe holding device according to claim 1, further comprising a drainage channel leading from the inside of the sealed pad to the outside of the probe holding member. Tactile holding device. A method for inspecting an object to be inspected using the sealed probe holding device according to claim 1,
By pressing the holding device against the object to be inspected, the sealing pad is brought into close contact with the surface of the object to be inspected, and water supplied from an external water supply source is introduced into the sealing pad through the water supply path, In a state where the water introduced in is stored in the cylindrical housing below along the side surface of the ultrasonic probe, the measurement is performed by the probe. Inspection method.