JPH11337531A - Ultrasonic inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an ultrasonic inspection device to detect the existence of a defect of a object to be inspected and the position of the defect automatically, accurately and surely, and to make a scanning unit attachable and detachable with respect to the object to be inspected easily and rapidly. SOLUTION: This inspection device is equipped with a scanning device 5 and a detecting device. The scanning device 5 is equipped with a cylindrical fixed frame 7 fixed and supported on the end of a cylindrical member 2, a cylindrical rotary frame 13 installed freely rotatively on the cylindrical fixed frame 7, and an ultrasonic probe 32 capable of moving in the direction parallel to the axis L2 of the cylindrical rotary frame 13 and capable of contacting to the inner circumferential surface of the object to be inspected of the cylindrical member 2. The detecting device is equipped with a means by which ultrasonic wave is sent to an ultrasonic probe 32, and data of the object to be inspected are gathered as waveforms, and the position where the data are gathered is also taken in.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ultrasonic flaw detector.

[0002]

2. Description of the Related Art For example, ultrasonic flaw inspection has been conventionally performed to detect the presence or absence of defects in a welded portion between a hemispherical member and a cylindrical member such as a reactor pressure vessel lower mirror and a control rod driving mechanism stub tube. Have been done.

[0003] One example of a conventional ultrasonic inspection method is manual inspection. In this manual flaw detection, an operator holds the ultrasonic probe in his hand and abuts the ultrasonic probe from the inside of the tubular member to a portion to be inspected, such as a welded part, and moves the ultrasonic probe around the circumference. It is moved in the axial direction and the circumferential direction of the cylindrical member along the inner surface, and the obtained result is displayed as an image on a television screen, and the presence or absence of a defect is visually determined. The axial position and the circumferential position of the ultrasonic probe with respect to the cylindrical member are measured by a worker using a scale.

[0004] In addition, in some cases, only the conventional ultrasonic probe is automatically scanned, and the presence / absence of a defect is visually determined from an image displayed on a television screen, as in the case of manual flaw detection.

[0005]

In the above-described ultrasonic flaw detection, the judgment is visually made in any case, so that the change in the ultrasonic transmittance in the thickness direction of the cylindrical member is corrected and the same is applied. It is difficult to determine the presence or absence of a defect under the conditions, and the detection result is not accurate.

Further, when the ultrasonic inspection is performed by manual inspection, the position of the ultrasonic probe is measured by a scale, so that the position detection accuracy is poor, and therefore the defect detection position has no reproducibility. However, it is difficult to accurately detect the position where the defect exists, and the ultrasonic probe cannot be pressed uniformly against the inner circumferential surface of the cylindrical member. Accurate detection of the resulting defect cannot be performed.

[0007] In the ultrasonic flaw detection, only the scanning of the ultrasonic probe is automatically performed, and the apparatus is fixed to the subject when the presence or absence of a defect is visually determined from an image displayed on a television screen. Therefore, an air cylinder is required, and the components of the driving system (motor, gear) are large, so that the weight increases, and as a result, it is difficult to install or remove the scanning device from the cylindrical member.

The present invention has been made in view of the above circumstances, and has an object to automatically and accurately detect the presence or absence of a defect, and to automatically and accurately detect the position of a defect. It is an object of the present invention to easily and quickly install and remove a scanning device for scanning a stylus with respect to a cylindrical member.

[0009]

The present invention comprises a scanning device and a detecting device, wherein the scanning device is fixed to and supported on one axial end of a cylindrical member having a portion to be inspected, A rotating frame inserted into the cylindrical member and attached to the fixed frame so as to be rotatable in a circumferential direction of the cylindrical member; and a rotating frame movable in a direction parallel to an axis of the rotating frame. And an ultrasonic probe which is attached so as to be pressed against an inspection target portion of the cylindrical member, wherein the detection device applies ultrasonic waves transmitted to the inspection target portion to the ultrasonic probe. Means for acquiring the waveform of the ultrasonic wave reflected back from the inspection object portion as waveform data and capturing the axial position and the circumferential position of the rotating frame from which the data was acquired. That.

Therefore, according to the present invention, at the time of ultrasonic flaw detection, the ultrasonic probe is pressed against the portion to be inspected of the cylindrical member at a constant pressure, and moves in a zigzag manner in the axial direction and the circumferential direction. Flaw detection is performed.

The data of the inspection object is collected together with the position as a waveform. Therefore, in the present invention, the presence or absence of a defect and the position of the defect can be automatically analyzed in consideration of the shape and material of the object to be inspected in the inspection target portion, and the position locating accuracy and the reproduction accuracy of the inspection result are improved. Further, since there is little difference between individuals, the reliability of the apparatus is improved, and the installation and removal of the scanning unit can be performed easily and quickly.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 12 show an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a hemispherical member such as a lower mirror of a reactor pressure vessel, 2 denotes a cylindrical member such as a stub tube of a control rod driving mechanism, and cylindrical member 2 denotes an inner surface of the hemispherical member 1. And is fixed by welding 4 concentrically with a through hole 3 formed in the hemispherical member 1.

Reference numeral 5 denotes a scanning device installed on the cylindrical member 2. Thus, the scanning device 5 includes a support plate 6 whose lower surface is supported by the upper edge of the cylindrical member 2, and the scanning device 5 is mounted on the cylindrical member 2 on the lower surface of the support plate 6. Cylindrical fixed frame 7 inserted into the cylindrical member 2 when
Is installed.

On the outer periphery of the cylindrical fixed frame 7, a plurality of circumferentially spaced predetermined intervals are provided so that the scanning device 5 can be brought into contact with the inner peripheral surface of the cylindrical member 2 when the scanning device 5 is installed on the cylindrical member 2. (FIG. 5
(Three places) are mounted.

The seat 8 can be fixed to the cylindrical fixing frame 7 with a countersunk screw, and can be replaced according to the inner diameter of the cylindrical member 2.

An annular member 9 (see FIGS. 3 and 5) is formed on the lower surface of the support plate 6 so as to be fitted to the upper end of the tubular member 2 at a predetermined interval in the radial direction. It is mounted so as to be concentric with the fixed frame 7.

A plurality of hydraulic cylinders 10 are horizontally arranged on the annular member 9 at positions corresponding to the seats 8 in plan view, and the axis L1 of the hydraulic cylinders 10 is set at the center of the seat 8 in the width direction. It is arranged radially so as to pass through to the center of the cylindrical fixed frame 7.

The piston rod 10 of the hydraulic cylinder 10
A gripping member 11 is attached to the end of a for gripping the cylindrical member 2 from the outer circumference in cooperation with the seat 8 and fixing the scanning device 5 to the cylindrical member 2.

A cylindrical rotary frame 13 is fitted to the bearing 12 fitted inside the lower end of the cylindrical fixed frame 7 so as to be able to rotate horizontally in the circumferential direction of the cylindrical member 2. The pulley 15, the belt 16, and the pulley 17 are driven by a driving device 14 disposed on the cylindrical fixed frame 7.
And can be driven to rotate.

At the lower end of the cylindrical rotary frame 13, two sets of guide means 18 for maintaining the attitude of the scanning device 5 are arranged at positions shifted by 180 degrees in the circumferential direction. Thus, the guide means 18 includes a ball 19 which can freely rotate in all directions, and moves forward and backward in the radial direction of the cylindrical rotary frame 13 via a screw driven by a driving device 20 to move the ball. 19 is a cylindrical rotating frame 13
And can roll on the inner peripheral surface of the roller.

On the outer periphery of the cylindrical rotating frame 13, a notch 21 extending in a direction parallel to the axis L 2 of the cylindrical rotating frame 13 is formed so as to be located above each guide means 18. The notch 21 is provided with a belt conveyer type elevating device 23 that allows the endless timing belt 22 to move up and down in parallel with the axis L2.

A guide rail 24 extending in the vertical direction, that is, in a direction parallel to the axis is provided in the notch 21 of the cylindrical rotary frame 13 in parallel with the lifting device 23.
The guide rail 24 is disposed so that the center in the width direction coincides with the center of the ball 19 and the axis L2 of the cylindrical rotating frame 13 when viewed from the front as shown in FIG.

As shown in detail in FIGS. 8 and 9, a substrate 25 protruding toward the guide rail 24 is attached to the timing belt 22 of the lifting device 23, and a guide provided on the side of the substrate 25 facing the guide rail 24. The plate 26 is slidably fitted to the guide rail 24 via the dovetail groove 27.

On the side of the substrate 25 facing the outer periphery of the cylindrical rotary frame 13, a bracket 28 is attached so as to protrude radially outward of the cylindrical rotary frame 13, and the bracket 28 has a cylindrical center. An arm 30 that projects obliquely outward in the radial direction of the cylindrical rotating frame 13 is pivotally mounted via a horizontal pin 29 that is tangential to the rotating frame 13, and a tip of the arm 30 is parallel to the horizontal pin 29. An ultrasonic probe 32 is pivotally mounted via a horizontal pin 31.
Thus, the arm 30 is urged by a spring (not shown), and when the scanning device 5 is installed in the tubular member 2,
The ultrasonic probe 32 can come into contact with the inner peripheral surface of the inspection target portion such as the annular weld 4.

A well-known cable carrier 41 extending in the longitudinal direction of the guide rail 24 is attached to the notch 21 of the cylindrical rotary frame 13 so as to face the lifting device 23 with the guide rail 24 interposed therebetween. Have been. The cable bear 41 is a cable for supplying power to the lifting device 23, a cable for supplying ultrasonic waves to the ultrasonic probe 32, and a cable for returning ultrasonic waves reflected and returned from the ultrasonic probe 32. It is for mounting.

As shown in FIGS.
A control unit 35 for transmitting and receiving signals to and from an inspection device 34 having an ultrasonic probe, an operation / display unit 36 for transmitting and receiving signals to and from the control unit 35, and a control unit 35 An ultrasonic flaw detector 37 for transmitting and receiving signals;
Signal from operation / display unit 36 and ultrasonic flaw detector 37
And a data collecting device 38 for collecting a signal from the device.

Between the control unit 35 of the detection device 33 and the inspection device 34, a UT (ultrasonic) signal, a UT trigger as a scan start command, a position signal of the ultrasonic probe 32, and a control signal can be transmitted and received. In addition, the power supply for driving the movable device can be supplied from the control unit 35 to the inspection device 34.

A UT signal and a UT trigger signal can be transmitted and received between the control unit 35 and the ultrasonic flaw detector 37. The UT signal and the UT trigger are transmitted from the ultrasonic flaw detector 37 to the data acquisition device 38. Can be given,
A position signal of the ultrasonic probe 32 can be given from the operation / display unit 36 to the data acquisition device 38.

Next, the operation of the present invention will be described.

When performing an ultrasonic flaw inspection of a portion to be inspected, such as a weld 4 of the cylindrical member 2 to the hemispherical member 1, the seat 8 must be large enough to abut the inner periphery of the cylindrical member 2. By exchanging and inserting the scanning device 5 into the tubular member 2 and bringing the lower surface of the support plate 6 into contact with the upper end of the tubular member 2,
The scanning device 5 is supported by the tubular member 2.

Further, by operating the fluid pressure cylinder 10, the gripping member 11 is brought into contact with the outer periphery of the cylindrical member 2,
The scanning device 5 is fixed to the cylindrical member 2 by the and the seat 8, and the driving device 20 is driven so that the guide means 18 is protruded toward the inner peripheral side of the cylindrical member 2, and the ball 19 is inserted into the cylindrical member 2. Make contact with the circumference.

Thus, the scanning device 5 is completely set in the tubular member 2.

Next, a drive device (not shown) of the elevating device 23 is activated to move the timing belt 22 up and down, and the two sets of ultrasonic probes 32 are positioned at predetermined positions of the inspection object portion.
In a state where the ultrasonic probe 32 is in contact with the inner peripheral surface of the inspection target portion by the resilience of the spring, the ultrasonic probe 32 moves the timing belt 22 of the elevating device 23 in a predetermined inspection range in the vertical direction. It is raised and lowered so as to reciprocate, and the cylindrical rotating frame 13 is rotated in the circumferential direction by the driving device 20. For this reason,
The ultrasonic probe 32 moves along a zigzag trajectory A as shown in FIG. 12, and an ultrasonic inspection is performed.

When the ultrasonic probe 32 moves up and down while being guided by the guide rails 24, the ultrasonic probe 32 does not move in the circumferential direction of the cylindrical rotating frame 13 and is less likely to move. When the ultrasonic probe 32 rotates together with the cylindrical rotary frame 13, the cylindrical probe 13 is guided by the ball 19 when the ultrasonic probe 32 rotates with the power. There is no radial displacement. Therefore, the size and weight of the scanning device 5 can be reduced.

The ultrasonic wave given from the ultrasonic flaw detector 37 of the detecting device 33 is transmitted from the ultrasonic probe 32 to the inspection object portion, and the ultrasonic wave emitted and returned is given to the detecting device 33 and appropriately Is displayed on the screen of the operation / display unit 36, or displayed on the screen of the ultrasonic flaw detector 37, and the data collection device 38 is provided with a cylindrical rotating frame 13 Data on the position in the center direction, the position in the circumferential direction of the cylindrical rotating frame 13, the presence or absence of a defect at the position, and the state of the defect are collected as a continuous waveform.

The axial position of the cylindrical rotating frame 13 and the circumferential position of the cylindrical rotating frame 13 are detected, for example, by providing a rotary encoder or the like to the driving device and the driving device 14 (not shown) of the lifting device 23. By leaving
Can be done accurately. The data collected by the data collection device 38 can be viewed on the screen of the data collection device 38 as appropriate, and the data can be printed out as needed.

That is, in the present embodiment, after all the flaw detection waveforms are collected as data, a cross-sectional image of the inspection target portion is operated and generated on the display unit 36, and the shape and material of the inspection target portion such as the weld 4 are formed. In consideration of the above, it is possible to automatically analyze the presence / absence of a defect and the position of the defect, thereby improving both the location accuracy and the reproduction accuracy of the inspection result.

Further, since the ultrasonic probe 32 can be pressed against the inspection target portion with a constant pressing force and can be inspected at a constant speed, it is difficult for the ultrasonic inspection inspection to show individual differences in the ultrasonic inspection inspection. Reliability is improved.

Further, since the scanning device 5 is small and lightweight,
The scanning device 5 can be installed and removed by a single worker, and the scanning device 5 can be securely installed on the tubular member 2. The ultrasonic flaw detection inspection can be performed in any direction such as horizontal or oblique, not vertical.

FIGS. 13 to 15 show another example of a support structure of the ultrasonic probe 32. The substrate 25 which can be moved up and down by being guided by the guide rail 24 by elevating the timing belt 22 is provided. Fluid pressure cylinder 3 capable of moving horizontally in the radial direction of cylindrical rotating frame 13
9 is disposed and the piston rod 3 of the hydraulic cylinder 39
An ultrasonic probe 32 is pivotally supported at the tip of 9a via a horizontal pin 40 so as to be able to abut on the portion to be inspected.

In this case, at the time of inspection, the fluid pressure cylinder 39 is operated to bring the ultrasonic probe 32 into contact with the inner peripheral surface of the inspection object portion, and the ultrasonic inspection is performed. Even with such a structure, the ultrasonic probe 32 in the above-described embodiment may be used.
In the same manner as described above, the ultrasonic probe 32 can be pressed against the inspection target portion with a constant pressing force, and the ultrasonic inspection can be performed.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

[0045]

According to the ultrasonic flaw detector of the present invention, I) it is possible to automatically analyze the presence / absence of a defect and the position of the defect in consideration of the shape and material of the inspection target part. II. ) The location accuracy and reproducibility of the inspection results are improved. III) The ultrasonic probe can be pressed against the inspection target with a constant pressing force, and the inspection can be performed at a constant speed. IV) The scanning device is small and lightweight, so that one operator can install and remove the scanning device, and work can be performed easily and quickly. V) Inspection can be performed irrespective of the orientation of the cylindrical member, so that the inspection target can be widened, and various excellent effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view showing a state in which a scanning device is set on a cylindrical member in an ultrasonic flaw detector of the present invention.

FIG. 2 is a layout diagram of a detection device used in the ultrasonic flaw detector of the present invention.

FIG. 3 is a partially cutaway front view of the scanning device of the ultrasonic flaw detector according to the present invention.

4 is a view in the direction of arrows IV-IV in FIG. 3;

FIG. 5 is a view in the direction of arrows VV in FIG. 3;

FIG. 6 is a view taken in the direction of arrows VI-VI in FIG. 3;

FIG. 7 is an enlarged view of a portion VII in FIG. 3;

FIG. 8 is an enlarged view of a portion VIII in FIG. 4;

FIG. 9 is a view taken in the direction of arrows IX-IX in FIG. 8;

FIG. 10 is a view as viewed in the direction of arrows XX in FIG. 8;

11 is a block diagram of the detection device shown in FIG.

FIG. 12 is a diagram showing a trajectory of an ultrasonic probe when an inspection is performed by the ultrasonic inspection device of the present invention.

FIG. 13 is a front view showing another example of the support structure of the ultrasonic probe.

14 is a view in the direction of arrows XIV-XIV in FIG. 13;

15 is a view taken in the direction of arrows XV-XV in FIG.

[Explanation of symbols]

 2 Cylindrical Member 5 Scanning Device 7 Cylindrical Fixed Frame (Fixed Frame) 13 Cylindrical Rotating Frame (Rotating Frame) 32 Ultrasonic Probe 33 Detector 35 Control Unit (Means) 36 Operation / Display Unit (Means) 37 Super Ultrasonic flaw detector (means) 38 Data collection device (means) L2 axis

Claims (1)

[Claims] 1. A scanning device comprising: a scanning device; and a detection device, wherein the scanning device is fixed to and supported on one axial end of a cylindrical member having a portion to be inspected, and inserted into the cylindrical member. A rotating frame attached to the fixed frame so as to be rotatable in a circumferential direction of the tubular member; and a tubular member attached to the rotating frame so as to be movable in a direction parallel to the axis of the rotating frame. With an ultrasonic probe adapted to be pressed against the inspection target part in the
The detection device gives an ultrasonic wave transmitted to the inspection target portion to the ultrasonic probe, collects the waveform of the ultrasonic wave reflected and returned from the inspection target portion as waveform data, and collects the data. Means for taking in the axial position and the circumferential position of the sampled rotating frame.