JPH0515224B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for holding a probe in a probe holder,
Insert and transport the test material into the center of the probe holder,
Regarding a probe rotation type ultrasonic flaw detection device that performs flaw detection by rotating a probe holder around the test material at high speed, in particular, high-precision temperature compensation is performed for a dimension measurement probe. The present invention relates to an ultrasonic flaw detection device.

[Prior Art] Generally speaking, among metal tubes, those that require high quality and high precision, such as ultra-small diameter tubes used in nuclear power, are checked to prevent scratches on the tube and defects in the material. In addition to rigorous ultrasonic flaw detection,
Strict ultrasonic measurements are also performed to measure dimensions such as inner and outer diameters and wall thickness (hereinafter referred to as measurements).

Conventionally, as an ultrasonic flaw detection device, a plurality of probes are held in a probe holder, a water chamber is formed, and the holder is rotated to move the probes around the test material. There is a method that performs high-density flaw detection by drawing a spiral scanning locus on the outer circumferential surface of the test material by rotating the test material and simultaneously transporting the test material in the length direction.

On the other hand, as an ultrasonic dimension measuring device, conventionally, a water tank with an appropriately sealed insertion hole and a side wall is used.
Place the measurement probe and rotate the material to be inspected.
There is a device that is inserted through the above-mentioned insertion hole and transported inside the aquarium to perform dimension measurements. Furthermore, in order to perform more precise dimensional measurements, some devices are equipped with a temperature compensation probe to compensate for changes in the speed of ultrasonic waves due to temperature.

[Problems to be Solved by the Invention] However, these conventional devices are mutually independent devices, and it is necessary to perform flaw detection and dimension measurement separately. Therefore, it is necessary to prepare the work for each one, which increases the amount of work, becomes complicated, and has the disadvantage that the time required for inspection also increases.

In addition, since conventional dimension measuring devices use a water tank, it is necessary to rotate the material to be inspected. Therefore, the number of rotations cannot be increased, making inspection time-consuming. There is.

Furthermore, in the case of dimension measuring devices equipped with temperature compensation probes, the temperature distribution of the medium in the tank is uneven,
The disadvantage is that the compensation accuracy is not sufficient.

The present invention was made to solve these drawbacks, and it is possible to perform flaw detection and dimension measurement at the same time, requiring only one work setup, reducing the amount of work, and making the work easier. Moreover, it is an object of the present invention to provide a probe rotating type ultrasonic flaw detection device that does not take much time for inspection and can perform precise temperature compensation during dimension measurement.

[Means for Solving the Problems] The present invention holds a probe in a probe holder, inserts and conveys a specimen into the center of the probe holder, and moves around the specimen. In a rotating probe type ultrasonic flaw detection device that performs flaw detection by rotating the probe holder at high speed, as a means to solve the above problems, a A partition wall having a guide hole for guiding the material to be inspected is provided, and a water chamber for flaw detection and a water chamber for dimension measurement are separated by the partition wall, and the former is equipped with a flaw detection probe, while the latter is equipped with a dimension measurement water chamber. A measuring probe is disposed, and a temperature compensation probe is attached near the dimension measuring probe.

[Function] As shown in the above problem solving means, the present invention has the following features:
A water chamber for flaw detection and a water chamber for dimension measurement are formed in the probe holder, and the former is equipped with a flaw detection probe, while the latter is equipped with a dimension measurement probe. Dimensions can be taken at the same time. In this case, both water chambers are separated by a partition wall, and water distances suitable for each can be set.

Further, in the present invention, the speed of sound is measured by a temperature compensating probe disposed in the water chamber for dimension measurement, and the change in the sound speed of ultrasonic waves due to temperature is compensated for during dimension measurement. In the temperature compensation of the present invention, the volume of the water chamber for dimension measurement is set to be as small as possible in order to minimize the centrifugal force during rotation.Moreover, since the water is stirred by high speed rotation, The temperature distribution of the medium in the water chamber becomes almost uniform, allowing for highly accurate testing. Therefore, dimension measurement can be performed with high precision.

In addition, in the present invention, the test material is guided by the guide hole provided in the center of each of the partition walls so that the center of the test material and the center of rotation are almost aligned, so that the test material and the probe are guided. The object to be inspected is positioned by the guide hole without alignment with the center of rotation of the holder, and is conveyed so as to be automatically aligned with the center of rotation. Therefore, even if it is an extremely small diameter pipe, flaw detection and dimension measurement can be performed accurately.

[Example] An example of the present invention will be described with reference to the drawings.

<Configuration of Example> Figure 1 is a perspective view showing the external appearance of a rotating probe type ultrasonic flaw detection device to which this example is applied, and Figure 2 shows a probe holder, which is the main part of this example. A sectional view showing,
FIG. 3 is an explanatory diagram showing the arrangement of each probe in this embodiment.

First, the probe rotation type ultrasonic flaw detection apparatus shown in FIG. 1 will be explained.

In the figure, each part of the device of this embodiment is arranged in a straight line on the upper surface of a pedestal 10, and a device main body 12 for rotational driving and electrical connection of signals is installed in the center, and one end of the main body 12 is installed. A probe holder part 13 is connected to the mount 10, and transport devices 16 and 18 for transporting the test material P are provided at both ends of the pedestal 10 in the longitudinal direction. These devices are arranged with their central axes aligned so that the test material P can be transported without bending.

Probe holder 14 inside probe holder part 13
As shown in FIG.
2. Consists of a flaw detection section 24 and a medium introduction section 26,
The overall structure consists of multiple cylinders with different diameters stacked concentrically. Partition walls 28, 30 and 32 are provided at the boundary between each cylinder. The parts shown in the figure are all parts that rotate at high speed, and there is an outer cover 34 (first
Non-rotating parts such as (see figure) are provided.

A water chamber 36 for size measurement and a water chamber 38 for flaw detection are provided by the partition walls 28, 30, and 32. In addition, at the center of each of the partition walls 28, 30 and 32,
Through holes 40, 42 and 44 are provided concentrically. These through holes 40, 42 and 44 include
Positioning bushings 4 each precisely machined so that the center coincides with the center of the probe holder 14 and the inner diameter is approximately equal to the outer diameter of the test material P.
6, 48 and 50 are fitted. The holes provided in these bushings 46, 48, and 50 serve as guide holes for guiding the test material P so that its axis is aligned with the rotation center of the probe holder 14.

The dimension measurement section 22 includes dimension measurement probes 52 and 54,
A temperature compensation probe 56 (see FIG. 3) and a reflection plate 58 are arranged with their ends facing the measurement water chamber 36. The probes 52, 54, 56 are held and mounted by appropriate holding members. For example, as for the probes 52 and 54, as shown in FIG. 2, the water distance is adjusted by a holding member 60, and the probes 52 and 54 are held and fixed at that position.

The flaw detection section 24 includes flaw detection probes 62, 64, 6.
6 and 68 are arranged with each end facing the water chamber 38 for flaw detection. Note that the flaw detection probe 68 is
Although it is located in front of the cut plane and should not originally appear in the cross-sectional view of FIG. 2, it is shown in the same figure to show the position.

These flaw detection probes 62, 64, 66, and 68 are set obliquely with respect to the center of rotation in order to cause the ultrasonic waves to be obliquely incident on the test material P. This probe also allows adjustment of the water distance and angle using a suitable holding member. For example, the flaw detection probes 62 and 64 are held by holding members 70 and 72 such that the water distance and angle can be adjusted.

The mounting portion 20 is formed in a flange shape on the outside of the partition wall 28 and is fixed to a mounting portion 74 formed in a flange shape on the main body 12 side with a plurality of bolts 76 . A probe 5 is attached to this mounting portion 20.
A connector plug 78 for connecting a signal line leading to the second etc. is provided corresponding to the probe.

On the other hand, the plug 78 is provided on the main body 12 side.
A receptacle 80 is provided in the mounting portion 74 correspondingly. A signal line 82 connected from this receptacle 80 is connected to a signal transfer unit (not shown) such as a capacitor coupling that electrically connects the stationary side and the rotating side. Further, the mounting portion 74 is connected to the rotor 84 at its center. The rotor 84 is rotationally driven by an electric motor and a power transmission means (both not shown) housed in the pedestal 10, and rotates the probe holder 14 at high speed via the mounting portion 74. Further, a guide member 86 is inserted through the center of the rotor 84 to position the test material P at the center of rotation.

The medium introduction part 26 provided at the end of the probe holder 14 is fixed to the partition wall 32 with bolts 88. A groove 9 is provided on the outer periphery of this medium introducing portion 26.
0 is provided, and a water guide portion 92 that communicates with the water chamber 38 for flaw detection from a proper location of this groove 90 is provided. Further, a water guide hole 93 is also provided in the partition wall 30 so that the water chamber 38 for flaw detection and the water chamber 36 for size measurement are communicated with each other. The groove 90 is formed in the non-rotating case 9.
4, and a medium (usually water) is injected under pressure from a medium inlet 96 provided in the case 94.

In the above configuration, the measurement water chamber 36 is provided on the mounting part side of the probe holder 14, but this is due to the structure in which the probe holder 14 is supported in a cantilevered manner by the mounting part 20. Therefore, the purpose is to stabilize the rotation by setting the large-diameter portion where a large centrifugal force is applied to the base side.

Further, in the above embodiment, cylindrical covers 98 and 1 are provided on the outer peripheries of the dimension measurement section 22 and the flaw detection section 24, respectively.
00 is installed. This is probe holder 1
This is to prevent the water discharged from 4 from scattering excessively and to protect the lead wire of the probe.

<Operation of the embodiment> The operation of the embodiment configured as described above will be explained with reference to the above-mentioned FIGS. 1 to 3 and FIG. 4.

First, the rotor 84 is rotated by an electric motor (not shown) to rotate the probe holder 14 at high speed.
Further, water as a medium is injected into the probe holder 14 from the medium inlet 96. This injection is performed by connecting a pipe to the medium inlet 96. The injected water reaches the water chamber 38 for flaw detection and the water chamber 36 for dimension measurement from an appropriate place in the groove 90 through the water guide portion 92, filling them, and the overflowing water flows from a drain (not shown) to the probe holder 14. It is discharged to the outside.

On the other hand, the test material P is inserted into the guide member 86 in the rotor 84 from the tip by the conveyance device 16, and is further inserted into the partition walls 28, 30 and 3 of the probe holder 14.
Bushings 46, 48 and 50 provided in 2
The paper is sequentially inserted into the paper, reaches the transport device 18, and is transported at a constant speed in the direction of arrow A in FIG.

Dimension measurement and flaw detection are started when the approach of the tip of the test material P is detected by a proximity sensor such as a limit switch (not shown).

Dimension measurement involves emitting ultrasonic waves perpendicularly to the specimen P from the dimension measurement probes 52 and 54, measuring the time it takes for the echo to return, and determining the outer diameter and inner diameter of the specimen P. Measure dimensions, wall thickness, etc.

Furthermore, since the above-mentioned dimensions tend to have errors due to changes in the speed of sound due to changes in the temperature of the medium, temperature compensation is performed.

This temperature compensation is performed using a temperature compensation probe 56 and a reflective plate 58 that faces the temperature compensation probe 56 at a constant distance.
It is done with. That is, the ultrasonic waves emitted from the temperature compensation probe 56 are reflected by the reflection plate 58,
Again, the temperature compensation probe 56 detects the change in sound speed due to the temperature change in the time required to be detected, and thereby corrects the signal from the dimension measurement probe to eliminate the influence of the temperature change. do.

This temperature compensation effect will be explained with reference to FIG. FIG. 4 shows an example of measuring the outer diameter of a specimen.

First, the outer diameter D of the material P to be tested is determined using the dimension measuring probe 52.
W ₀ is the water distance between and W ₁ and W ₂ respectively
Then, it is given by the following formula.

D=W ₀ -(W ₁ +W ₂ )...(1) On the other hand, let the water distance between the temperature compensation probe 6 and the reflection plate 58 be W ₃ , and as the ultrasonic wave travels the water distance W ₃ , Assuming that the measured value of the required time is t ₃ , the temperature compensation coefficient α is determined as follows.

α=W ₃ /t ₃ ...(2) Therefore, the time required for the ultrasonic wave to travel the water distance W ₁ and W ₂ , respectively, is measured using the dimension measurement probes 52 and 54.
Measure t ₁ and t ₂ . Here, if the temperature compensation coefficient α given by the above second equation is used, the temperature compensated water distances W ₁ and W ₂ are given by the following equation.

W ₁ = αt ₁ W ₂ = αt ₂ Therefore, by substituting these relationships into the first equation above, the outer diameter D of the test material P is given by D = W ₀ - α (t ₁ + t ₂ ). It will be done.

In flaw detection, ultrasonic waves are emitted obliquely from the flaw detection probes 62, 64, 66, and 68 to the test material P, and are reflected back at the interface of the flaws or defects inside the test material P. This is done by detecting incoming ultrasonic echoes. In this flaw detection, since the probe holder 14 is rotating at high speed, the four probes 6, 64, 6
Flaw detection is carried out using four threaded scanning traces by No. 6 and No. 68.

In this way, in this example, dimension measurement and flaw detection are
Since the materials to be inspected are conveyed only once and the inspection is carried out simultaneously, it is possible to significantly reduce the working time.

In addition, during dimension measurement and flaw detection, the material P to be tested is
Since it is restrained by the bushings 46, 48 and 50 attached to the partition walls 28, 30 and 32 at the location, the dimension measurement and flaw detection are performed with the center axis of the bushings substantially aligned with the rotation center of the probe holder 14. . Therefore, it is possible to accurately measure dimensions and detect flaws even for specimens having a small diameter such as extremely small diameter pipes. In addition, in this embodiment, these bushings 4
6, 48, and 50 are tapered at their openings, so that when the tip of the test material is inserted, there is no collision with the tip, and the material can be easily inserted.

Furthermore, in this embodiment, since the temperature compensation probe 56 performs temperature compensation for the speed of sound during dimension measurement, accurate dimension measurement can be performed.

<Modification of the embodiment> In the above embodiment, a through hole is provided in the center of the partition wall of the probe holder, and a positioning bushing is fitted into the through hole, but the through hole itself is precisely machined to form a guide hole. , and the bushing may be omitted.

Further, in this embodiment, four flaw detection probes are used, but of course the number is not limited to this.

[Effects of the Invention] As explained above, the present invention can perform flaw detection and dimension measurement at the same time, requires only one work setup, reduces the amount of work, and facilitates the work. Inspection does not take much time, and precise temperature compensation can be performed during dimension measurement.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the external appearance of a rotating probe type ultrasonic flaw detection device to which this embodiment is applied, and FIG. 2 is a sectional view showing a probe holder, which is the main part of this embodiment.
FIG. 3 is an explanatory diagram showing the arrangement of each probe of this embodiment, and FIG. 4 is an explanatory diagram showing the effect of temperature compensation, taking as an example the case where the outer diameter of a specimen is measured. P... Test material, 10... Frame, 12... Device main body, 14... Probe holder, 16, 18... Transport device, 20... Mounting section, 22... Dimensions section, 24...
...Flaw detection section, 26...Medium introduction section, 28, 30, 3
2... Bulkhead, 34... Outer cover, 36... Water chamber for dimension measurement, 38... Water chamber for flaw detection, 40, 42, 44...
...Through hole, 46, 48, 50...Butching, 5
2, 54...Dimension measurement probe, 56...Temperature compensation probe, 58...Reflection plate, 60...Holding part, 6
2,64,66,68...flaw detection probe, 70,
72... Holding member, 74... Mounting part, 76, 88
... Bolt, 78 ... Plug, 80 ... Receptacle, 82 ... Signal line, 84 ... Rotor, 86 ...
... Guide member, 90 ... Groove, 92 ... Water guide portion, 9
4...Case, 96...Medium inlet, 98,10
0...Cover.

Claims (1)

[Claims] 1. A probe is held in a probe holder, a test material is inserted and conveyed through the center of the probe holder, and the probe holder is moved around the test material at high speed. In a rotating probe type ultrasonic flaw detection device that performs flaw detection by rotating, a partition wall having a guide hole for guiding the test material is provided at both ends and the center of the probe holder to perform flaw detection. A water chamber and a dimension measurement water chamber are separated by the partition wall, and the former is provided with a flaw detection probe, while the latter is provided with a dimension measurement probe, and the dimension measurement water chamber is provided with a flaw detection probe. A rotating probe type ultrasonic flaw detection device comprising a temperature compensation probe attached near the probe to measure the speed of sound and compensate for the temperature. 2. When providing the water chamber for flaw detection and the water chamber for dimension measurement of the probe holder, the former is placed on the distal end side of the probe holder, the latter on the proximal end side of the probe holder,
The probe rotating type ultrasonic flaw detection device according to claim 1, wherein the proximal end of the probe holder is attached to a rotation drive section. 3. Probe rotation in which the probe is held in a probe holder, the test material is inserted and conveyed through the center of the probe holder, and the probe holder is rotated at high speed around the test material. In the method of operating an ultrasonic flaw detection system, a dimension measurement probe is used to measure the dimensions of the material to be inspected, and this measurement signal is output, and a temperature compensation probe is used to measure the dimensions of the material to be inspected due to temperature changes. A probe characterized by comprising: a step of detecting a change in sound velocity and thereby correcting the dimensional signal; and a step of performing flaw detection on a test material using a flaw detection probe. How to operate a rotary type ultrasonic flaw detection device.