JPH0619340B2 - Probe setting method in ultrasonic testing equipment for pipes - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of setting a position and an incident angle of a probe for circumferential oblique angle flaw detection in an ultrasonic flaw detector for a pipe.

(Prior art) In an ultrasonic flaw detector by a local water immersion method, in which a material to be inspected such as a steel pipe or a steel rod is spirally conveyed, and a flaw detection water tank is contacted from the lower surface of the material to be inspected, Conventionally, the incident angle and water distance of the probe provided in the above were set manually.

(Problems to be Solved by the Invention) However, the conventional setting method by manual operation has a problem in that the probe cannot be set accurately and the setting cannot be made in a short time.

Therefore, the applicant of the present application proposed in Japanese Patent Application No. 59-170900 a flaw detection water tank capable of automatically setting the incident angle and water distance of the probe in order to solve the above-mentioned conventional problems.

The present invention uses the flaw detection water tank previously proposed by the present applicant to automatically and accurately set the incident angle and water distance of a probe for circumferential bevel flaw detection arranged in the flaw detection water tank. It is intended to provide a method.

(Means for Solving the Problems) The present invention provides a flaw detection water tank provided with a follow-up roller that comes into contact with and follows the outer surface of a pipe material that is spirally conveyed, and is separated in the axial direction of the pipe material; With a base that moves up and down with
A probe for water distance measurement provided on the base at a position immediately below the axial center of the pipe material, at the same height as the reference point of the probe for water distance measurement, and in the axial direction of the pipe material. A circumference whose rotation center is provided on the base at positions separated in the orthogonal direction and which is rotated around the rotation center in a plane orthogonal to the axial direction of the pipe material and whose tilt angle can be adjusted. When performing ultrasonic flaw detection on a pipe using an ultrasonic flaw detector equipped with a probe for bevel angle flaw detection, a probe for circumferential bevel flaw detection according to the outer diameter and wall thickness of the pipe The water distance and the incident angle of the child are selected from the water distance and the incident angle that have been input in advance, and based on the selected water distance and the incident angle and the input outer diameter, the pipe material is Calculate the vertical distance to the outer surface and the tilt angle of the probe for circumferential bevel flaw detection, The inclination angle of the probe is set to the calculated inclination angle, and the water distance is measured based on the vertical distance from the reference point of the calculated water distance measuring probe to the outer surface of the pipe material while raising and lowering the base. The height of the reference point of the probe for water is set with the center of the follower roller as a reference, and then the water distance to the outer surface of the pipe material is measured by the water distance measuring probe, and then the calculation is performed. The probe for water distance measurement is moved up and down again to match the measured water distance with the water distance corresponding to the vertical distance from the reference point of the probe for water distance measurement to the outer surface of the pipe material. Is a method for setting a probe in an ultrasonic flaw detector for a pipe material, which is characterized in that the height of the reference point is corrected.

(Operation) According to the method of the present invention, even if the follow-up roller that is disposed at the entrance / exit of the flaw detection water tank and follows the outer surface of the pipe material that is spirally conveyed and wears is accurately worn or incident, Since the angle can be set, accurate flaw detection can be performed automatically.

(Example) The present invention will be described below with reference to the accompanying drawings.

First, a schematic structure of a flaw detection water tank used when carrying out the method of the present invention will be described with reference to FIGS. 3 and 4.

In the figure, 1 is a flaw detection water tank, and the flaw detection water tank 1 is an upper tank portion 2.
And a lower tank part 3 attached to the lower part of the same.

Reference numeral 4 denotes a probe group for axial oblique flaw detection, which is provided at a front and rear position of a pass line immediately below the axial center of the pipe material with a required interval, for detecting circumferential defects, and 5 denotes the probe group 4, A water distance measuring probe provided between 4 and 6 are circumferential bevels for detecting axial defects provided in parallel below the pipe material and at a required distance from the axis of the pipe material. This is a probe group for flaw detection, and these probe groups 4 and 6 and the probe 5 are arranged on the same base 7. Then, among them, only the probe group 6 for circumferential oblique angle flaw detection has the center of rotation O (first position) in the plane orthogonal to the axial direction of the pipe material 27 as shown in FIG. (Refer to the drawing) It is pivotally held on the base 7 so as to be freely rotatable.

Reference numeral 9 denotes an up-and-down position adjusting mechanism for vertically moving a base 7 including both the probe groups 4 and 6 and the probe 5 by a required distance. The up-and-down position adjusting mechanism 9 is a lower tank. A motor 10 is attached to the portion 3 in a hanging shape, a screw shaft 11 directly connected to an output shaft of the motor 10, and a female screw member 12 screwed to the screw shaft 11, and the upper end of the female shaft member 12 is the base 7. And a connecting member 13 attached to the base member 7, and the screw shaft 11 is normally and reversely rotated by the forward and reverse rotation of the motor 10, and the base 7 is vertically moved via the female screw member 12 and the connecting member 13 which are screwed to the screw shaft 11. It is what makes me. In addition, 1 in the figure
Reference numeral 4 is a guide rod for guiding the vertical movement of the connecting member 13. Although not shown in the drawings, the vertical position of the base 7 is such that the guide rod 14 is attached in a hanging manner, and the detection rod is attached to the guide plate 15 attached to the connecting member 13 in a hanging manner like the guide rod 14 in a vertical direction. It can be confirmed by reading as a voltage value with potentiometer.

Reference numeral 16 denotes an incident angle adjusting mechanism for rotating the probe group 6 for circumferential oblique angle flaw detection by a required angle to set an incident angle. The incident angle adjusting mechanism 16 is the guide plate 1
5, the motor 17 mounted in a pendant shape, and the motor 17
A rotary shaft 19 which is directly connected to the output shaft of the rotary shaft 19 and has an upper part formed with the worm 18, and the worm 1 of the rotary shaft 19.
Axis 2 for rotatably holding the probe group 6 so as to mesh with 8.
The worm wheel 21 is keyed to 0, and the probe group 6 is rotated by a predetermined angle through the worm 18 and the worm wheel 21 of the rotary shaft 19 by the forward and reverse rotation of the motor 17. The inclination angle of the probe group 6 due to the rotation causes the potentiometer 24 to rotate through the spur gear 22 fitted to the rotary shaft 19 and the spur gear 23 meshing with the spur gear 22, and the voltage of the potentiometer 24 is changed. It can be confirmed by reading it as a value. At the time of attaching the potentiometer 24, at least two points of the voltage value of the potentiometer 24 and the inclination angle of the actual probe group 6 are measured,
It is necessary to calibrate the potentio voltage value and the tilt angle of the probe group.

In the figure, 25 is a seal member for sealing the upper water tank portion 2 and the lower water tank portion 3 at the connecting member 13 and the rotating shaft 19 portion, and 26 is a pipe member that is arranged at the inlet / outlet portion of the flaw detection water tank 1 and is spirally conveyed. This is a follow-up roller that comes into contact with and follows the outer surface.

Next, a case of carrying out the method of the present invention using the flaw detection water tank 1 configured as described above will be described with reference to FIGS. 1 and 2.

First, when the outer diameter and wall thickness of the pipe member 27 to be flaw-detected is input, the appropriate incident angle of the probe group 6 for circumferential oblique angle flaw detection determined in advance by the t / D of the pipe member 27. And the water distance is selected.

In order to set the proper incident angle and water distance, the height and tilt angle of the probe group 6 for circumferential oblique angle flaw detection are calculated by using the input value and known dimensions.

That is, in FIG. 1, the center of rotation O of the probe group 6 for circumferential oblique angle flaw detection is at the same height as the reference point Q of the probe 5 for measuring water distance, and the horizontal distance L thereof is L. ₁ is known,
Further, the horizontal distance B between the reference point Q of the probe 5 for water distance measurement and the center of the follower roller 26, the reference point Q at the lower limit position of the probe 5 for water distance measurement, and the center of the follower roller 26. Vertical distance H _L , the distance P _WL from the reference point Q of the probe 5 for water distance measurement to its tip, and the probe group 6 for circumferential oblique angle flaw detection
The distance P _L from the rotation center O to the tip thereof and the initial outer diameter d of the follower roller 26 are also known. On the other hand, the outer diameter OD of the pipe material 27 is an input value, and the proper incident angle A ₂ and the water distance (S ₂ −P _L ) of the probe group 6 for circumferential oblique angle flaw detection are outside the input pipe material. It is a value selected based on the diameter OD.
Then, this known L ₁ , the input OD, and the selected A ₂
And the reference point Q of the probe 5 for measuring the water distance based on the water distance
And the distance H ₂ to the outer surface of the pipe material 27 are calculated by the following formula.

Then, using this H ₂ , a known L ₁ and input O
Based on D, the selected A ₂ and the water distance, the inclination angle A _S of the probe group 6 for circumferential oblique angle flaw detection is calculated by the following formula.

However, Subsequently, based on H ₂ obtained by the above equation, the height of the reference point Q of the probe 5 for measuring the water distance with respect to the center of the follower roller 26 is obtained by the following equation.

_{H PS} = H-H ₂ ...... _{where, H = H L + C-} OD / 2 C = (OD / 2 + d / 2) 2 -B 2 above equations, probe group for flaw detection circumferential beveled by the formula 6 inclination angle a _S and the reference point Q of the probe 5 for water distance measurement height, the height H _PS rotational center O of the probe group 6 for circumferential oblique flaw in other words, When the calculation is made, the incident angle adjusting mechanism 16 is operated so as to become the calculated value A _S , the operation is terminated when the reading of the potentiometer becomes A _S, and the calculated value H _PS becomes The vertical position adjusting mechanism 9 is operated so as to move the base 7 up and down, and the operation ends when the reading of the potentiometer reaches H _PS .

Accordingly, when the outer diameter of the follower roller 26 is the initial value,
The tilt angle and height corresponding to the proper incident angle and the water distance of the probe group 6 for circumferential oblique flaw detection are set.

Then, when the tilt angle and height of the probe group 6 for circumferential oblique angle flaw detection are set, next, for example, the flaw detection water tank 1 is moved off-line and the test piece is moved by the follower roller 26 of the flaw detection water tank 1. It is supported, and the water distance in this state is measured by the water distance measuring probe 5.

This measured value is compared with the water distance corresponding to H ₂ calculated by the above formula, that is, H ₂ −P _WL, and when they do not match, the vertical position adjusting mechanism 9 is again set so that the measured value becomes equal to the calculated value. The base 7 is moved up and down by operating it, and the height of the reference point O of the probe 5 for measuring the water distance, in other words, the height of the rotation center O of the probe group 6 for oblique bevel flaw detection is set. to correct.

When this correction is completed, the test piece is scanned to correct GAIN and DAC, and when the predetermined scanning is completed, the flaw detection tank 1 is moved online. As the test piece scanning device, for example, Japanese Patent Application No. 59-233429 previously proposed by the present applicant is used.

In addition, although the water tank drawing method has been described in the present embodiment, it goes without saying that an online method using a long test piece is also sufficiently applicable.

(Effects of the Invention) As described above, according to the method of the present invention, the known dimensions such as the outer diameter of the pipe material and the distance between the centers of the probes arranged in the flaw detection water tank and the relationship distance between the follower roller and the pipe material are known. Set the tilt angle and height of the probe for circumferential bevel flaw detection based on the water distance and the incident angle selected according to the dimensions of, and then measure the water distance from the set position to the pipe material. When the calculated value and the measured value are different from each other, the height of the probe for circumferential oblique angle flaw detection is corrected so that the measured value is obtained. Even if the value changes, the accurate setting can be performed and the flaw detection accuracy is improved.

[Brief description of drawings]

FIG. 1 is an explanatory view of the method of the present invention, FIG. 2 is the same as the flow chart, and FIGS. 3 and 4 are views of one embodiment of the flaw detection water tank used when carrying out the method of the present invention. (A) is a plan view, (b) is a sectional front view, FIG. 4 (a) is a partially cutaway front view of the incident angle adjusting mechanism, and (b) is a sectional view showing the relationship between the worm and the worm wheel. The side view shown. 5 is a contactor for water distance measurement, 6 is a probe group for circumferential oblique angle flaw detection, 9 is a vertical position adjusting mechanism, 16 is an incident angle adjusting mechanism, 26 is a follow-up roller, and 27 is a pipe material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-58-219453 (JP, A) SAIKAI 60-70063 (JP, U)

Claims (1)

[Claims] 1. A flaw detection water tank provided with a follow-up roller that comes into contact with and follows the outer surface of a spirally conveyed pipe material in the axial direction of the pipe material, a base that moves up and down in the flaw detection water tank, and a pipe of the pipe material. A probe for water distance measurement provided on the base at a position directly below the axis, and a direction at the same height as the reference point of the probe for water distance measurement and orthogonal to the axial direction of the pipe material. A circular bevel flaw detector whose rotation center is provided on the base at a position spaced apart from each other and which can be rotated around the rotation center in a plane orthogonal to the axial direction of the pipe material to adjust the tilt angle. When performing ultrasonic flaw detection on a pipe using an ultrasonic flaw detector equipped with a probe for water, the water of the probe for circumferential oblique angle flaw detection according to the outer diameter and wall thickness of the pipe to be detected The distance and incident angle are selected from the water distance and incident angle that have been input in advance, and the selected water distance and incident angle are selected. Based on the incident angle and the input outer diameter, calculate the vertical distance from the reference point of the probe for water distance measurement to the outer surface of the pipe material and the inclination angle of the probe for circumferential oblique angle flaw detection. The inclination angle of the probe for oblique flaw detection is set to the calculated inclination angle, and the vertical distance from the reference point of the calculated probe for measuring water distance to the outer surface of the pipe material while raising and lowering the base. Based on, set the height of the reference point of the probe for water distance measurement with the center of the follower roller as a reference, and then measure the water distance to the outer surface of the pipe material with the probe for water distance measurement. After that, the water distance is measured by moving up and down the base again to match the measured water distance with the water distance corresponding to the vertical distance from the calculated reference point of the water distance measuring probe to the outer surface of the pipe material. Of the pipe material characterized by correcting the height of the reference point of the probe for Probe setting probe in ultrasonic flaw detector.