JP7051532B2 - Anchor bolt ultrasonic flaw detection inspection device and inspection method - Google Patents

Description

The present invention relates to an ultrasonic flaw detection inspection device and an inspection method for anchor bolts, and in particular, an anchor bolt ultrasonic flaw detection inspection device capable of inspecting deterioration of bolts in an invisible part of an anchor bolt without damaging the embedded part of concrete. And about the inspection method.

A conventional anchor bolt ultrasonic flaw detection inspection method is described in, for example, Japanese Patent No. 6088088 (Patent Document 1). According to the same publication, the anchor bolt ultrasonic flaw detector inspects the corroded portion of the anchor bolt 27 by using an ultrasonic probe. Anchor bolt ultrasonic flaw detectors can be mounted on the head of anchor bolts, and have a probe mounting part that is cylindrical and has an inclined surface on which an ultrasonic probe can be mounted, and a probe mounting part. It includes a probe rotating jig that rotatably holds the portion, and a digital ultrasonic flaw detector that determines deterioration of the anchor bolt by receiving a reflected echo of an ultrasonic flaw detector signal from an ultrasonic probe.

Japanese Patent No. 6088088

Conventional anchor bolt ultrasonic flaw detection inspections have been performed as described above. Although deterioration can be sufficiently determined by such a method, there are cases where deep flaw detection is not sufficient.

The present invention has been made to meet the above problems, and an object of the present invention is to provide an anchor bolt ultrasonic flaw detection inspection method and apparatus capable of inspecting bolt deterioration in a deeper range.

The anchor bolt ultrasonic flaw detection inspection device according to the present invention inspects the corroded portion of the anchor bolt by using an ultrasonic probe. Anchor bolt ultrasonic flaw detectors can be mounted on the head of an anchor bolt, and have a probe mounting part that is cylindrical and has an inclined surface on which an ultrasonic probe can be mounted, and from the probe. The ultrasonic probe is a line focusing type probe, which includes a deterioration determining means for determining deterioration of an anchor bolt by receiving a reflected echo of an ultrasonic flaw detector signal.

Preferably, the line focusing probe propagates the ultrasonic wave in the first direction, and the oscillator of the line focusing probe is curved in a direction parallel to the first direction.

More preferably, the size of the oscillator is larger than that of the conventional probe.

According to one aspect of the present invention, the probe rotating jig includes a probe rotating jig that rotatably holds the probe mounting portion, and the probe rotating jig is a cylindrical rotation having a spiral groove on the outer circumference. The push portion includes a portion and a cylindrical push portion provided so as to be movable downward along the outer periphery of the rotating portion, and the push portion has an engagement portion on the inner circumference that can be engaged with the spiral groove of the rotating portion. Then, when pushed downward, the engaging portion moves downward while rotating along the groove, whereby the probe is rotated, and the probe rotation jig is axially driven by a spring. Is urged to the upper side.

According to another aspect of the present invention, it is an anchor bolt ultrasonic flaw detection inspection method for inspecting a corroded portion of an anchor bolt by using an ultrasonic probe, in which a line focusing type ultrasonic wave is applied to the head of the anchor bolt. A probe rotating jig with a probe mounting part was mounted with the probe tilted with respect to the axis of the anchor bolt, and the probe rotating jig was pushed in the axial direction of the anchor bolt. At this time, the probe mounting part can be rotated around the axis of the anchor bolt, and the probe rotating jig is pushed in the axial direction of the anchor bolt to rotate the probe mounting part around the axis of the anchor bolt. By doing so, the deterioration of the anchor bolt is determined by receiving the ultrasonic flaw detection signal from the probe.

According to the present invention, since the flaw detection portion is detected by using a line focusing type probe, the sound pressure of the reflected echo from the flaw detection portion at the time of detection becomes high. Therefore, it is possible to provide an ultrasonic flaw detector that can inspect an anchor bolt at a deep position in the axial direction because the apparent probe position is deepened.

It is a figure for demonstrating the difference in the flaw detection range between the case of using a conventional non-focusing type probe and the case of using a line focusing type probe. It is a schematic diagram which shows the whole structure of the anchor bolt ultrasonic flaw detection inspection apparatus. It is a figure which shows the inspection range of the conventional probe. It is a figure which shows the inspection range of the probe which concerns on this embodiment. It is a figure which shows the image when the focusing type probe is applied to an anchor bolt. It is a figure which shows the flaw detection waveform when the conventional probe is used, and when the focusing type probe which concerns on this embodiment is used. It is a figure explaining the effect when the thickness of the acrylic wedge is changed. It is a figure which shows the outline of the rotary jig which concerns on this embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the flaw detection range of the anchor bolt ultrasonic flaw detection inspection apparatus disclosed in Patent Document 1 and the anchor bolt ultrasonic flaw detection inspection apparatus according to this embodiment will be described. FIG. 1 is a diagram for explaining this range. With reference to FIG. 1, here, anchor bolts 27 are embedded on the foundation concrete 31. As shown in FIG. 1, a level adjusting mortar 33 may be installed between the foundation concrete 31 and the base plate 32. Thread defects due to corrosion may occur at this location. In the system of Patent Document 1, inspection was possible in the range above the base plate 32, but flaw detection was not possible in the range below that.

On the other hand, in this embodiment, the inspection can be performed in the range below the base plate 32. The reason will be explained below.

First, the configuration of the anchor bolt ultrasonic flaw detection inspection device 10 according to this embodiment will be described. FIG. 2 is a schematic view showing the configuration of the anchor bolt ultrasonic flaw detection device 10 according to this embodiment. With reference to FIG. 2, the configuration of the anchor bolt ultrasonic flaw detection inspection device 10 is basically the same as the configuration of the inspection device disclosed in Patent Document 1, and the configuration of the probe used is different. With reference to FIG. 2, the anchor bolt ultrasonic flaw detector 10 according to this embodiment uses a line focusing type probe as the vertical probe 16.

An angle wedge 17 is attached to the vertical probe 16 so that ultrasonic waves are incident at an angle. In this state, the vertical probe 16 and the probe rotary jig 11 are used to detect the anchor bolt 27 once in the circumferential direction.

The probe rotary jig 11 is a cylinder having a rotary mechanism 12 including a push-in portion 12a and a rotary portion 12b for rotating the vertical probe 16 and a circular upper end portion fixed to the lower end portion of the rotary mechanism 12. A vertical probe accommodating portion 13 that accommodates the vertical probe 16 inside, and a guide portion 14 that is attached to the head of the anchor bolt 27 and guides the vertical probe accommodating portion 13 in the axial direction. including.

The vertical probe accommodating portion 13 is provided on the outer periphery of the upper end portion 13a, the cylindrical portion 13b extending downward from the upper end portion 13a and accommodating the vertical probe 16 inside, and the lower end portion of the cylindrical portion 13b. Includes an outer ring 13c.

The guide portion 14 includes an upper end portion 14a having a through hole through which the cylindrical portion 13b is penetrated in the center, and a cylindrical portion 14b extending downward from the upper end portion 14a and surrounding the head of the anchor bolt from the outside, and the cylindrical portion 14b. The inner peripheral surface of the vertical probe accommodating portion 13 guides the outer peripheral ring 13c of the vertical probe accommodating portion 13.

The digital ultrasonic flaw detector 20 connected to the vertical probe 16 and analyzing the data from the flaw detector 20 is equipped with the anchor bolt corrosion investigation application software 21, and is capable of setting flaw detection conditions, displaying flaw detection results, and the like.

The digital ultrasonic flaw detector 20 connected to the vertical probe 16 and analyzing the data from the flaw detector 20 is equipped with the anchor bolt corrosion investigation application software 21, and it is possible to set the flaw detection conditions and display the flaw detection results. , The same as Patent Document 1.

Further, the vertical probe 16 was fixed to the upper end surface of the angle wedge 17. Here, the angle wedge 17 has a cylindrical shape having an inclined surface inclined at a predetermined angle at the upper end, and has a shape that can be attached to the upper end portion of the anchor bolt 27. Here, the inclination angle selects the optimum angle for detecting a wide range of inspection target parts at once. Since the optimum angle varies depending on the diameter of the anchor bolt, such as the pitch shape and dimensions of the thread thread, a plurality of angle wedges 17 can be prepared in advance and replaced as needed.

Next, the probe used in this embodiment will be described in comparison with the probe used in Patent Document 1.

3 and 4 show the case where the anchor bolt ultrasonic flaw detection device using the non-focusing type probe of Patent Document 1 is used (FIG. 3) and the line focusing type according to the embodiment of the present invention. It is a figure for demonstrating the level difference of the sound pressure of the ultrasonic beam when the probe is used (FIG. 4). FIG. 3A is a diagram showing the spread of the ultrasonic beam when the unfocused probe used in Patent Document 1 is used, and FIG. 3B is a diagram showing the spread of the ultrasonic beam in FIG. 3A. , Is a view of the portion indicated by arrows IIIB-IIIB, and is a diagram showing the reach of the ultrasonic beam. FIG. 3C is the portion indicated by arrows IIIB-IIIB shown in FIG. 3B. It is a figure which shows the sound pressure at the corresponding position in the reach of the ultrasonic beam of. In FIG. 3C, the X-axis is the sound pressure, the right direction is high, and the Y-axis is the depth of the anchor bolt. The corresponding range is shown by a dotted line. In FIG. 3, when the anchor bolt 27 is detected in the depth range a to b, the sound pressure level is in the range a1 to b1.

On the other hand, FIG. 4A is a diagram showing the spread of the ultrasonic beam when the line focusing type probe according to the embodiment of the present invention is used, and FIG. 4B is a diagram showing the spread of the ultrasonic beam. 4 (A) is an arrow view of the portion indicated by the arrow IVB-IVB, and is a diagram showing the reachable range of the ultrasonic beam. FIG. 4 (C) is the arrow shown in FIG. 4 (B). It is a figure which shows the sound pressure at the corresponding position in the reach of the ultrasonic beam of the part shown by IVB-IVB. In FIG. 4C, the X-axis is the sound pressure, the right direction is high, and the Y-axis is the depth of the anchor bolt. The corresponding range is shown by a dotted line.

In this embodiment, since the line focusing type probe 10 is used, as shown in FIG. 4B, there is an ultrasonic focusing point c at a predetermined position from the upper part of the anchor bolt 27, and the flaw is detected. The range is in the range of depths d to e below this position, and the sound pressure level is in the range of d1 to e1.

As shown in the figure, the range to be detected is the depths d to e, and the position is deeper than the position shown in FIG. This is possible because the line focusing type probe 10 is used, so that a higher sound pressure than a1 in the case of FIG. 3 can be obtained at the focusing point c, and the sound pressure levels of a1 to b1 in FIG. 3 can be obtained. This is because similar levels can be obtained in the deep range of d1 to e1 as shown in FIG. 4 (C).

Next, the details of the probe of the flaw detector according to this embodiment will be described. In this embodiment, a line focusing probe 10 having a frequency of 5 MHz is used to inspect a deeper part. The line focusing probe is usually used by bending the vibrator in a direction orthogonal to the propagation direction of the ultrasonic wave to focus the beam, but in this embodiment, the propagation direction of the ultrasonic wave (figure). By bending the vibrator in the parallel direction (indicated by middle f), the sound pressure is high to the deep part of the anchor bolt, which is focused so that the direction of the sound wave matches f by the bending as shown in the figure. It was possible to inject a sound wave beam. Furthermore, the inspection range was expanded by increasing the size of the diameter of the vibrator from the conventional 6.4 mm to 20 mm or more.

The focusing type probe is originally used for the purpose of focusing the ultrasonic beam on the part to be detected to improve the detection ability (S / N ratio), but this time, as explained in FIG. 4, the focusing type is used. Use a beam deeper than the focusing point of the probe to inspect the area corresponding to the construction site of the anchor bolt level adjustment mortar.

In addition, the direction of the ultrasonic beam to be focused is set to be orthogonal to the anchor bolt axis direction, and the ultrasonic beam with high sound pressure is applied to the depth deeper than the focusing point.

The effect of such a configuration will be described. 5A and 5B are diagrams for explaining the effects of such a configuration, and FIGS. 5A and 5B correspond to FIGS. 3B and 3A, respectively, and FIG. 5C corresponds to FIGS. 5A and 5C. Shows a comparison of the possible search range when using a focused probe with that when a conventional non-focused probe is used. As described in FIG. 3 (C), since a large sound pressure is obtained at the deeper position of the anchor bolt, the sound pressure level at which the probe obtains the reflected echo is higher, similar to that shown in FIG. Since it is obtained at a deep position, the apparent probe position becomes deep as shown in FIG. 5 (C).

Next, the flaw detection waveform obtained by a specific probe will be described. FIG. 6 shows the flaw detection waveform (A) (inspection range 60 mm to 140 mm) obtained by the ultrasonic probe disclosed in Patent Document 1 and the flaw detection waveform (B) (inspection range 110 mm) obtained in this embodiment. ~ 250 mm). In the figure, the X-axis is the distance in the depth direction of the anchor bolt, and the Y-axis is the amplitude of the obtained echo. Comparing FIGS. 6 (A) and 6 (B), (B) is better. It can be seen that the data having a larger amplitude is obtained in the deeper direction of the anchor bolt than in the case of (A).

Next, the angle wedge (acrylic wedge) 17 will be described. In this embodiment, the thickness of the acrylic wedge is made thicker than that in the case of Patent Document 1. Specifically, the thickness was increased from 2 mm in the case of Patent Document 1 to 12 mm in this embodiment.

FIG. 7 is a diagram showing a flaw detection waveform (A) when the acrylic wedge used in the flaw detector of Patent Document 1 is used and a flaw detection waveform (B) when the acrylic wedge used in this embodiment is used. be. In the figure, the X-axis is the detection range in the depth direction of the anchor bolt, and the Y-axis is the amplitude of the obtained echo. In the figure, the part indicated by the dotted line ○ indicates an unnecessary delayed echo during flaw detection.

Comparing FIGS. 7 (A) and 7 (B), both of them obtain reflected echoes with high amplitude in a wide range in the deep direction of the anchor bolt, but (B) is an unnecessary delayed echo at the time of flaw detection. It can be seen that the occurrence of is small.

Next, the rotary jig in this embodiment will be described. In the system of Patent Document 1, the push-in portion of the rotary jig is manually pushed in, and the cylindrical cam inside the rotary jig makes one round in accordance with the movement of the push-in portion, and the probe makes one round in conjunction with the cylindrical cam. At this time, the flaw detection data was acquired. As an issue at the time of inspection, there was a case where the rotary jig was shaken when it was pushed in manually and stable flaw detection data could not be obtained. Therefore, in this embodiment, the structure is improved so that the rotary jig is not touched at the time of data acquisition.

FIG. 8 is a diagram showing a configuration of a push-in portion of the inspection jig. With reference to FIG. 8A, the push-in portion 12a of the rotary jig 11 includes a jig 11 attached to the anchor bolt 27 and a spring 41 attached to the jig 11. Ultrasonic probe 16, bolt tightening part (fixing jig) 11, push-in portion 12a, air damper 43, ultrasonic probe cable 44, base plate 32, nut 45, and bolt tightening. The attachment part 46 and the air adjusting nozzle 47 are included. Here, when the pushing portion 12a is pushed, the probe 16 rotates once.

In this embodiment, a spring 41 is applied to the inside of the inspection jig 11, the spring 41 is pushed by the pushing portion 12a, and when the spring 41 is released, the pushing portion 12a rises due to the returning force of the spring 41, and the internal cylindrical cam 48 is raised. The structure was changed to one round, and the method was changed to acquire flaw detection data when the push-in portion 12a rises. In addition, this system acquires flaw detection data when the probe 16 makes one round, and then performs the following processing in the system in order to display the acquired flaw detection data as a development view of 0 to 360 degrees.

The number of acquired flaw detection data for one lap is divided by the time taken for the probe to make one lap. Therefore, it is necessary for the push-in to return at a constant speed. Therefore, the air damper 43 is built in the rotary jig 11, and the speed is adjusted to be constant even when the pushing portion 12a is returned by the force of the spring 41.

From the above, it is possible to acquire stable data without touching the rotary jig (no extra force is applied) when acquiring flaw detection data. In addition, even if different inspectors operate the probe, the probe makes one round at a constant speed, so that there is no variation in data acquisition by the inspectors.

By using the above method, it is possible to inspect up to a depth of 250 mm from the crown of the anchor bolt 27. The inspectable range changes depending on the size of the anchor bolt 27. In addition, stable data acquisition has become possible.

As described above, in the anchor bolt deterioration determination system according to this embodiment, the inspectable range of the anchor bolt is expanded as compared with the anchor bolt ultrasonic flaw detection inspection device disclosed in Patent Document 1. According to one example, it is possible to inspect up to a depth of 250 mm from the top of the anchor bolt.

Although embodiments of the present invention have been described with reference to the drawings, the invention is not limited to the illustrated embodiments. It is possible to make various modifications to the illustrated embodiments within the same scope as the present invention or within the equivalent scope.

According to the present invention, since it is possible to provide an anchor bolt ultrasonic flaw detection inspection apparatus capable of inspecting an anchor bolt flaw detection portion to a deeper range, it is advantageously used as an anchor bolt ultrasonic flaw detection inspection apparatus.

10 Anchor bolt inspection device, 11 Explorer rotating jig, 12 Rotating mechanism, 12a Pushing part, 12b Rotating part, 13 Vertical probe accommodating part, 13a Upper end part, 13b Cylindrical part, 13c Outer ring, 14 Guide part, 15 Inspection section, 16 vertical probes, 17 angle wedges, 20 digital ultrasonic flaw detectors, 21 anchor bolt corrosion investigation application software, 25 concrete, 26 base plates, 27 anchor bolts,

Claims (4)

Anchor bolt ultrasonic flaw detector that inspects corroded parts of anchor bolts using an ultrasonic probe.
A probe mounting portion that can be mounted on the head of the anchor bolt and has an inclined surface that is cylindrical and has an inclined surface on which the ultrasonic probe can be mounted.
It includes a deterioration determination means for determining deterioration of an anchor bolt by receiving a reflected echo of an ultrasonic flaw detection signal from the probe.
The ultrasonic probe is a line focusing type probe, and is
The line focusing probe propagates ultrasonic waves in the first direction and propagates ultrasonic waves in the first direction.
The oscillator of the line focusing type probe is an anchor bolt ultrasonic flaw detection inspection device that is curved in a direction parallel to the first direction . The anchor bolt ultrasonic flaw detection inspection device according to claim 1 , wherein the size of the vibrator is larger than that of the non-focusing probe. Includes a probe rotating jig that rotatably holds the probe mounting portion.
The probe rotation jig has a cylindrical rotating portion having a spiral groove on the outer circumference and a cylindrical rotating portion.
Including a cylindrical push-in portion provided so as to be movable downward along the outer circumference of the rotating portion.
The pushing portion has an engaging portion on the inner circumference that can be engaged with the spiral groove of the rotating portion, and by being pushed downward, the engaging portion is rotated downward along the groove. Move in the direction, thereby rotating the probe and
The anchor bolt ultrasonic flaw detection inspection device according to claim 1 or 2, wherein the probe rotation jig is urged upward in the axial direction by a spring. Anchor bolt ultrasonic flaw detection inspection method that inspects corroded parts of anchor bolts using an ultrasonic probe.
Attach a probe rotation jig with a probe attachment part to the head of the anchor bolt, which attaches a wire focusing type ultrasonic probe at an angle to the axis of the anchor bolt.
The line-focused ultrasonic probe propagates the ultrasonic wave in the first direction and propagates the ultrasonic wave in the first direction.
The oscillator of the line focusing type ultrasonic probe is curved in a direction parallel to the first direction.
When the probe rotation jig is pushed in the axial direction of the anchor bolt, the probe mounting part can rotate around the axis of the anchor bolt.
By pushing the probe rotation jig in the axial direction of the anchor bolt and rotating the probe mounting part around the axis of the anchor bolt, the ultrasonic flaw detection signal from the probe is received and the anchor bolt Anchor bolt ultrasonic flaw detection inspection method for determining deterioration.

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