JP3253744B2 - Pipe weld inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flaw detection device for a pipe weld applied to a flaw detection work at a pipe site of a joint weld such as a gas-filled instrumentation pipe.

[0002]

2. Description of the Related Art For example, joints such as gas-filled instrumentation piping,
For the purpose of obtaining a high sealing function, they are hermetically connected by welding. In general, a weld defect is inspected at a joint weld of such a pipe immediately after welding or at the time of periodic inspection.

In the case of performing a flaw detection inspection of a joint welded portion of such a pipe, it is necessary to perform flaw detection scanning over the entire circumferential direction of the welded portion in a continuous pipe. In order to perform such scanning, a closed-loop trajectory is required as guide means for continuously moving the flaw detection device over the entire circumferential direction. However, since the pipe is endless, it has been previously configured in a closed-loop shape. Tracks cannot be set up.

Therefore, conventionally, when performing a flaw detection inspection of such a joint welded portion of a pipe, a track including a guide rail having a split ring structure or the like is located near the welded portion of the pipe to be inspected at a site such as a plant. The ultrasonic flaw detection mechanism is mounted on the installed ring-shaped orbit, and the ultrasonic flaw detection scanning is performed by the guide movement along the orbit.

[0005]

However, in the above-mentioned conventional technique, the installation of the track and the mounting of the ultrasonic flaw detection mechanism on the track are required as separate operations. For this reason, the number of installation devices and installation steps increases, and workability tends to deteriorate. In particular, it takes a great deal of time and effort to center the trajectory required for performing precise flaw detection scanning, and to adjust when mounting the ultrasonic flaw detection mechanism. If the track and the ultrasonic flaw detection mechanism have different configurations, the number of parts is large, the configuration is complicated, and handling is complicated. Furthermore, in the case of instrumentation pipes with a small pipe diameter, the connection pipe diameters for the header pipes and the like are small, so that the connections are of different diameters, and the joint welds are socket welded, but in this case the work is more troublesome, A lot of trouble is required.

The present invention has been made in view of such circumstances, and can eliminate the installation of a conventionally used track, thereby simplifying the equipment configuration and reducing the number of parts, as well as providing equipment at a piping site. It is an object of the present invention to provide a pipe welded flaw detector that can reduce the number of installation steps and can also perform the installation operation extremely easily as compared with the related art.

[0007]

In order to achieve the above object, the present invention is directed to a fixing base detachably mounted on an outer peripheral portion near a welded portion to be inspected for a pipe, and a fixing base for the fixing base. A substantially semi-arc-shaped support member provided on the base and arranged coaxially outside the peripheral wall of the pipe; and a substantially semi-arc-shaped second support member coaxially arranged on the support member and movable in the circumferential direction. A first moving member, a substantially semi-circular second moving member supported in a coaxial arrangement with the first moving member and movable in a circumferential direction; A first driving mechanism for rotating the second moving member forward and backward by approximately 90 ° in the same direction with respect to the first moving member; (2) The member is provided so as to be integrally movable with the moving member, and is located in the entire circumferential direction of the welded portion of the pipe. An ultrasonic flaw detection mechanism for performing oblique flaw detection by shape scanning.

According to a second aspect of the present invention, in the first aspect of the invention, the first drive mechanism and the second drive mechanism are constituted by an associated gear train, and the second moving member is the second moving member of the first moving member.
It is set so as to always rotate at twice the moving angle.

[0009]

According to the first aspect of the present invention, it is possible to perform one-touch attachment / detachment to / from the pipe in a one-side open state in which the support member, the first moving member, and the second moving member are all overlapped.

Therefore, according to the present invention, the flaw detection of the welded portion can be performed simply by directly attaching the flaw detection apparatus itself to the pipe without requiring any installation of a track on the pipe which has been conventionally used. The number of devices can be reduced and the number of installation steps can be reduced, so that the workability can be greatly improved.

After the installation, the moving members are rotated in the forward and reverse directions by the first and second driving mechanisms, whereby the flaw detection scanning over the entire periphery of the pipe can be smoothly performed. In this case, the rotation range of each moving member is a minimum of 180 ° in the forward and reverse directions, and extremely efficient work can be performed.

Further, the apparatus of the present invention has a single machine structure in which all the members are integrally assembled, so that the machine structure can be simplified and the number of parts can be reduced, and the man-hour for installing the equipment at the piping site can be reduced. In addition, it is possible to easily handle and efficiently perform a flaw detection or the like of a socket welded portion of a different diameter pipe such as an instrumentation pipe having a small diameter.

According to the second aspect of the present invention, the first driving mechanism and the second driving mechanism are constituted by a gear train, and the second moving member always rotates at a moving angle twice that of the first moving member. Since it is set, the operation of the ultrasonic flaw detection mechanism is performed smoothly and stably.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a flaw detector for welded pipes according to the present invention.

FIG. 1 is a structural view of a main part of the apparatus, FIG. 2 is an external view of the entire apparatus, FIG. 3 is a sectional view of the main part, and FIGS.

In this embodiment, as shown in FIG. 1, a weld 2 of a pipe 1 to be inspected is a socket weld, and the pipe 1 extends in a vertical direction.

FIG. 1 shows a pipe welded flaw detector 3 of this embodiment.
As shown in FIG. 2, a fixed base 4 is detachably mounted on an outer peripheral portion of the small-diameter pipe portion 1 a above the welded portion 2, and is provided on the fixed base 4 so as to be coaxial with an outer peripheral wall of the pipe 1. And a substantially semi-circular first moving member 6 and a second semi-circular supporting member 5 supported coaxially by the supporting member 5 and movable in the circumferential direction.
It comprises a moving member 7, a first driving mechanism 8 and a second driving mechanism 9 for driving the first and second moving members 6, 7, and an ultrasonic flaw detection mechanism 10 attached to the second moving member 7. I have.

The fixed base 4 has a structure in which a clamp mechanism 12 and a centering mechanism 13 are provided on upper and lower pieces 11a and 11b of a substrate 11 having a substantially L-shaped cross section. The clamp mechanism 12 is configured such that a pair of clamp arms 15 facing each other are supported via a ball nut 16 on a reverse screw type ball screw 14 provided along the upper piece 11 a of the substrate 11. The rotation of the knob 17 provided at the end of the ball screw 14 causes the ball screw 14 to rotate.
The ball nuts 16 screwed into the reverse threaded portions of the above-mentioned parts come into contact with and separate from each other, whereby the clamp arm 15 opens and closes so that the small-diameter pipe portion 1a can be gripped.

When the small-diameter pipe portion 1a is gripped by the clamp arm 15, the axial direction (x
(Direction), the axis of the support member 5 is set so as to coincide with the axis of the small-diameter pipe portion 1a. Note that the clamp mechanism 12 may be a magnet type.

The centering mechanism 13 is for aligning the axis of the support member 5 with the axis of the small diameter pipe portion 1a in a direction (y direction) orthogonal to the axis of the ball screw 14.
That is, the centering mechanism 13 is configured such that the upper surface of the mounting plate 17 integrally provided at the upper end of the support member 5 is attached to the lower surface of the lower piece 11b of the substrate 11 by a dovetail-type connecting portion 17a along the y direction.
The board 11 and the mounting plate 17 are configured to be able to contact and separate in the same direction by means of a feed screw 18 in a suspended state via a. Then, by rotating a knob 19 provided at an end of the feed screw 18, the mounting plate 17 is attached to the substrate 1.
1 so that the axis of the support member 5 can be aligned with the axis of the small-diameter pipe portion 1a in the y direction.

As shown in FIG. 3, the support member 5 is vertically elongated along the outer peripheral wall of the small-diameter pipe portion 1a, and an outer peripheral surface having a substantially semicircular arc shape is a circumferential guide surface 5a. A substantially semi-circular first moving member 6 is slidably fitted in the circumferential guide surface 5a in the circumferential direction, and the inner peripheral surface of the first moving member 6 is dovetailed to the outer peripheral surface of the support member 5. It is slidably connected in the circumferential direction via a grooved connection portion 20. A second moving member 7 of substantially the same shape is connected to the lower end of the first moving member 6 via a dovetail type connecting portion 21 so as to be slidable in the circumferential direction.

A drive source such as a DC servo motor 22 is provided at a substantially central position in the circumferential direction of the support member 5, for example, a DC servo motor 22, and a drive gear 24 attached to an output shaft 23 of the motor 22 is a first moving member. 6 is engaged with the first driven gear 25. Thereby, the first drive mechanism 8 for rotating the first moving member 6 forward and backward substantially 90 ° around the pipe with respect to the support member 5.
Is configured.

Further, a pair of upper and lower idler gears 27a and 27b which are integrally rotated via a bracket 26 are provided on the outer peripheral surface of the first moving member 6 at a substantially central position in the circumferential direction. The upper idler gear 27 a meshes with a fixed gear 28 provided on the support member 5, and rotates in a direction opposite to the drive gear 24 by meshing with the fixed gear 28 when the first moving member 6 rotates. This upper idler gear 27a
A lower idler gear 27b that rotates integrally with the gear meshes with an interlock gear 29 attached to the bracket 26 in parallel with the lower idler gear 27b, and rotates the interlock gear 29 in a direction opposite to the idler gears 27a and 27b (in the same direction as the drive gear 24). It has become. The interlocking gear 29 meshes with a second driven gear 30 provided integrally with the second moving member 7 to further rotate the second moving member 7 in the same direction as the first moving member. That is, the above-described gear train constitutes a second drive mechanism 9 for simultaneously rotating the second moving member 7 forward and backward in the same moving direction with respect to the first moving member 5. In the present embodiment, the movement of the second moving member 7 is
The number of gears is set to double.

Further, an ultrasonic flaw detection mechanism 10 is provided on the second moving member 7 so as to be integrally movable. As shown in FIG. 1, the ultrasonic flaw detection mechanism 10 is attached to a vertically elongated frame 31 which hangs down from the second moving member 7 and rotates integrally therewith.
An ultrasonic probe 32 as an oblique probe is provided so as to be capable of reciprocating in a vertical direction (z direction) by a belt drive type driving unit 33. The ultrasonic probe 32 is pressed against the outer peripheral surface of the large-diameter pipe portion 1b in the vicinity of the welded portion 2 via a spring-attached probe holder 34 and a gimbal mechanism. Scanning is performed, and oblique flaw detection of the entire circumferential direction of the welded portion 2 is performed. In FIG. 1, reference numeral 35 denotes an encoder for detecting the rotation angle of the ultrasonic probe 32, reference numeral 36 denotes a drive motor for raising and lowering the ultrasonic probe 32, and reference numeral 37 denotes an encoder for detecting the vertical position. In FIG. 2, reference numeral 38 denotes a cover of the fixed base 3, 39 denotes a transfer handle, and 40 denotes a control cable.

Next, the operation will be described with reference to FIGS. 4 to 6 (note that FIGS. 4 to 6 are schematic plan views showing the rotating state of the apparatus, and FIGS. FIG.
The gear direction and the like are different from those shown in ().

FIG. 4 shows a state at the time of attachment / detachment of the apparatus (T1) and a state during the flaw detection (T3). FIG. 5 shows a state at the time of flaw detection start (T2).
FIG. 6 shows the state at the end of the flaw detection (T4).

As shown in FIG. 4, when the apparatus is mounted, the first and second moving members 6 and 7 are arranged so as to overlap with the supporting member 5, and the apparatus is open on one side. In this state, the device is fitted from the side of the pipe 1 and the clamp arm 1
At 5, the pipe 1 is gripped to fix the apparatus. In the state shown in FIG. 4, the ultrasonic probe 32 is located immediately below (T1 position).

At the time of flaw detection scanning, first, the drive gear 24 is rotated in one of the circumferential directions (clockwise a (reverse direction in FIG. 4)) from the state shown in FIG. In this case, the first driven gear 25 meshing with the driving gear 24 rotates, whereby the first moving member 6 rotates in the same direction. In addition, due to the rotation of the first moving member 6, the upper idle gear 27a (not shown in FIG. 4) meshes with the fixed gear 28 of the support member 5, rotates counterclockwise, and rotates integrally with the lower idle gear 27a. By the rotation of 27b, the interlocking gear 29 meshing therewith rotates clockwise (reverse direction), and the second moving member 7 also rotates in the same direction a.
In this embodiment, the rotation angle of the second moving member 7 is twice as large as that of the first moving member 6 due to the setting of the rotation angle.

In this embodiment, as shown in FIG.
When the first moving member 6 is rotated by 90 °, that is, when the second moving member 7 is rotated by 180 °, the operation is temporarily stopped. The position of the ultrasonic probe 32 in this state is a flaw detection start position (T2).

From the state shown in FIG. 5, the drive gear 24 is rotated in the other circumferential direction (counterclockwise b (positive direction) in FIG. 5). As a result, all the gear rotations are reversed from the above, and after passing through the position (T3) in FIG. 4, the ultrasonic probe 32 advances to the position (T4) rotated 360 ° shown in FIG. 6 and stops. During this time, flaw detection scanning is performed by the ultrasonic probe 32 (eg, 1 ° (0.5 mm) pitch in the circumferential direction), and a flaw plane map, a cross-section map, and the like are obtained by flaw detection data combined with the position information. Processing is performed.

After the end of the flaw detection, the operation reverse to the above is performed.
After returning to the state of FIG. 4, the device may be removed.

According to the above-described embodiment, the flaw detection of the welded portion can be performed only by directly attaching the flaw detection apparatus itself to the pipe without requiring any installation of a track for the conventionally used pipe. Therefore, the number of installation devices for the pipes can be reduced, and the number of installation steps can be reduced, so that workability can be significantly improved. In particular, according to this embodiment, the support member 5, the first
Since the attachment and detachment to the pipe 1 can be performed in the one-side opening state (the state of FIG. 4) in which the moving member 6 and the second moving member 7 are all overlapped, the attaching and detaching work is extremely easy.

The means for moving the ultrasonic flaw detection mechanism 10 over the entire circumferential direction of the pipe 1 includes a supporting member 5, a first moving member 6, a second moving member 7, a single motor 35, and a motor 35 associated therewith. The gear train can be realized with a compact configuration and the number of parts can be reduced.

In addition, the centering in one direction (x direction) by the clamp mechanism 12 can be easily set, and the support member 5 and the first moving member 6 can be easily set by the centering mechanism 13 in the direction (y direction) orthogonal to this. In addition, accurate centering of the second moving member 7 can be performed, and thereby, the ultrasonic flaw detection mechanism 10 can be accurately moved, so that high flaw detection accuracy can be obtained.

Further, since the apparatus according to the present embodiment has a single machine configuration in which all the members are integrally assembled, flaw detection or the like of a socket weld portion of a different-diameter pipe such as a small-diameter instrumentation pipe is performed. Also, the handling is easy and efficient work can be performed.

[0036]

As described above, according to the apparatus for detecting a welded portion of a pipe according to the present invention, it is possible to omit the installation of the conventional track, thereby simplifying the equipment configuration and reducing the number of parts. In addition, it is possible to reduce the number of man-hours required to install the equipment at the piping site, and to achieve an excellent effect that the installation operation itself can be performed much more easily than in the past.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part of an apparatus showing an embodiment of the apparatus of the present invention.

FIG. 2 is an external view of the entire apparatus according to the embodiment.

FIG. 3 is a sectional view of a main part of the apparatus according to the embodiment.

FIG. 4 is an operation explanatory diagram according to the embodiment, showing a state at the time of attachment and detachment.

FIG. 5 is an operation explanatory diagram according to the embodiment, showing a scanning initial state.

FIG. 6 is an operation explanatory view of the embodiment, showing a scanning end state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe 2 Weld part 4 Fixed base 5 Support member 6 1st moving member 7 2nd moving member 8 1st drive mechanism 9 2nd drive mechanism 10 Ultrasonic flaw detection mechanism

Continuation of the front page (72) Inventor Mitsuhiko Sugasawa 2-30 Kanda Jimbocho, Chiyoda-ku, Tokyo Tokyo Electric Power Company Nuclear Research Institute (56) References JP-A-3-206955 (JP, A) -27455 (JP, U) Fully open 1987-62961 (JP, U) Fully open 1986-139469 (JP, U) Fully open, 60-6011066 (JP, U) (58) Fields investigated (Int. . ^7, DB name) G01N 29/00 - 29/28 G01N 27/72 - 27/90

Claims (2)

(57) [Claims] 1. A fixed base detachably mounted on an outer peripheral portion near a welded portion to be inspected for a pipe, and a substantially semicircle provided on the fixed base and arranged coaxially outside a peripheral wall of the pipe. An arc-shaped support member, a substantially semicircular first movable member supported in a coaxial arrangement on the support member and movable in a circumferential direction, and supported in a coaxial arrangement on the first movable member in a circumferential direction. A substantially semi-arc-shaped second movable member movable along;
A first drive mechanism for rotating the first moving member forward and backward substantially 90 ° around the pipe with respect to the support member;
A second drive mechanism for rotating the moving member forward and backward by 90 ° in the same direction with respect to the first moving member; and a second driving mechanism provided integrally with the second moving member so as to be able to move integrally therewith. An ultrasonic flaw detection device for performing flaw detection by square scanning, comprising: 2. The first driving mechanism and the second driving mechanism are constituted by an associated gear train, and the second moving member is set to always rotate at twice the moving angle of the first moving member. Item 2. A flaw detector for pipe welds according to Item 1.