JPS60231164A - Ultrasonic flaw detector for piping - Google Patents

Abstract

PURPOSE:To improve the following property of a flaw detecting element by providing a driving source for changing the direction of detecting flaws of an ultrasonic flaw detecting element at the base end of a slider mounted on a travelling truck to make the tip of a lever having the flaw detecting element lighter weight. CONSTITUTION:A slider made up of a link block 23, a rod 24 and a feed nut 26 is mounted on a travelling truck 13 turning about a piping to be inspected in such a manner as to free to reciprocate. An arc-shaped rotary plate 28 is mounted rotatably at the tip of the slider and turned by a driving source 27 provided at the base end of the slider. A body 41 which has a bracket 39 composing a gimbals joint and an ultrasonic flaw detecting element 45 is mounted on a lever projected on the rotary plate. This minimizes the weight of the tip of the liver thereby enabling accurate inspection of flaws for a piping to be inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic flaw detection device for piping that can improve the followability of a flaw detector to a piping to be inspected and can automatically change the direction of flaw detection of the flaw detector by remote control.

There are pipes for various plants that flow high-pressure fluids or harmful fluids, and ultrasonic flaw detection is known as one method of defect inspection for welded joints of such highly dangerous pipes. As shown in FIG. 1, which shows the appearance of a conventional ultrasonic flaw detection device for piping, a piping to be inspected 101't! ``A two-sided band rail 102 detachably fixed to the piping to be inspected 101 so as to surround it is engaged with a traveling carriage lO3 that slides along the band rail 102. Due to the drive rotation of a pinion (not shown) that meshes with a gear 104 formed in A slider 106 that reciprocates along the arm rail 105 (by a feed drive mechanism (not shown)) has a lever 107 that can be displaced in the radial direction of the pipe 101 to be inspected. The proximal end of the piping 10 to be inspected is pivoted.
A holder 110 is rotatably held at the tip of the lever 107 that is pressed toward the first side via a gimbal joint 109t. The flaw detector is fixed.

Piping 1 to be inspected in such conventional ultrasonic flaw detection
As shown in Fig. 2(a) showing the flaw detection state of the welded joint in the blood vessel part of the 0th construction, and Fig. 2(a) showing its cross-sectional structure as viewed from the B-8 arrow, the holder 110 was twisted at the bent pipe part 111Kb. Even if you try to make the gimbal joint 109' work so that it comes into close contact with the outer circumferential surface of the curved tube part 111 by the spring force of the coil spring 108, if the tip of the lever 107 is not light, the flaw detector 112 will not be inspected. There is a drawback that due to minute irregularities on the surface of the pipe 101 or differences in the welded joint 1130, the pipe rises from the pipe to be inspected, making accurate inspection impossible. In particular, the holder 11 is used to change the direction of ultrasonic oscillation.
In the case where the 00 rotation machine is incorporated, the weight of the tip of the lever 107 increases, making the above-mentioned drawback even more noticeable.

In view of the above-mentioned problems in the conventional ultrasonic flaw detection equipment for piping, the present invention provides a lightweight structure in which the followability of the flaw detector to the piping to be inspected does not deteriorate even when a mechanism is incorporated that can automatically change the flaw detection direction of the flaw detector. The purpose is to provide a device with

The configuration of the ultrasonic flaw detection device for piping of the present invention that achieves this objective includes a traveling cart that revolves around the piping to be inspected;
A slider is attached to the traveling carriage so as to be able to reciprocate in a direction parallel to the turning center of the traveling carriage, and an axis perpendicular to the reciprocating direction of the slider is attached to the tip of the slider that is pressed against the piping to be inspected. an arc-shaped rotating plate rotatably supported around the slider; and a power transmission mechanism for rotating the rotating plate by connecting the rotating plate to a drive source provided at the base end of the slider. , a bracket rotatably attached to the tip of a lever protruding from the rotating plate in the ζX direction perpendicular to the center of rotation thereof; It comprises a rotatably held body, and a holder which is integrally attached to the body of the body and has an ultrasonic flaw detector mounted thereon.

Therefore, according to the present invention, the drive source for changing the flaw detection direction of the ultrasonic flaw detector is attached to the base end of the slider, and the bracket and body forming the gimbal joint are attached to the lever protruding from the rotating plate. As a result of being installed, the weight of the tip of the lever, where weight reduction is important, is kept to a minimum, and there is almost no negative effect of the increased weight due to the mechanism that changes the direction of ultrasonic oscillation of the flaw detector. Therefore, it is possible to efficiently perform accurate flaw detection inspection on the piping to be inspected.

Hereinafter, an embodiment of the ultrasonic flaw detection apparatus for piping according to the present invention will be described in detail with reference to FIGS. 3 to 7.

As shown in FIG. 3 showing the external appearance of this embodiment and FIG. 4 (a) showing the side shape thereof, a ring-shaped band rail 12 with a two-sided structure is detachably attached to the pipe 11 to be inspected. A running carriage 13 and a sabot 15 integrally connected to the running carriage 13 via an arcuate connecting link 14 are slidably engaged with the band rail 12. As shown in FIG. 4 Φ), which shows the right side shape of the traveling truck 13 in FIG. The drive rotation of the pinion 17 drives the carriage 13 and the support 1.
5 rotates around the piping to be inspected 11 along the band rail 12. Note that in this embodiment, the support 15 and the traveling cart 13 are separate bodies, but the support 15 is designed to incorporate a traveling function. Of course it is also possible.Support 1
5 has a pin 19 perpendicular to the center of rotation of the traveling trolley 13.
The support block 20 is swingably supported via the support block 20, and the front end of the support block 20 is located between the rear end of the support block 20 and a frame 21 that projects rearward from the sabot 15. A compression coil spring 22 is interposed to keep the section close to the surface side of the pipe 11 to be inspected. Support block 2
0, a pair of mutually parallel rods 24 each having a connecting butt 23 fixed to their tips are fitted to be slidable in a direction parallel to the turning center of the traveling truck 13, and these rods 2
A feed screw shaft 25 rotatably mounted on the support block 20 in parallel with the rod 24 is threaded with a feed nut 26 which is in the shape of a rod and is integral with the rod 24. Therefore, the support block 20
By operating the rod drive motor 27 attached to the rod drive motor 27, the feed screw shaft 25 is driven to rotate and the connecting block 23
reciprocates with the rod 24 relative to the support block 20 in a direction parallel to the feed screw shaft 25. In this embodiment, the slider is configured with the connecting pulley 23, the rod 24, and the feed nut 26, but other well-known configurations are also possible, and the mechanism for moving the rod 24 with respect to the pipe 11 to be inspected and the spring As the mechanism for approaching the surface of the pipe 110 to be inspected by force, other than this embodiment, a conventionally known mechanism can be appropriately adopted.

As shown in FIG. 5, which is an enlarged view of the part constituting the slider of this embodiment, a rotary plate 28 having a circular arc shape with a constant curvature is attached to the connecting block 23 and rotates about the center of the own vehicle via a bushing 29. A gear 30 having a pitch diameter corresponding to the curvature of the rotating plate 28 is carved into the rotating plate 28, and a pinion 31 is rotatably attached to the connecting block 23.
It meshes with the. An endless timing belt 34 is wound around the timing pulley 32 coaxially integrated with the binion 31 and the rtfc timing pulley S3 rotatably attached to the feed nut 26, and is protected from the outside by a cover 35. A transmission gear 36 coaxially integrated with the timing pulley 33 meshes with a driving gear 37 connected to a rotating plate pivoting motor (not shown) provided on the feed nut 26, thereby controlling the operation of this rotating plate driving motor. The rotating plate 28 rotates with respect to the connecting block 23 via the shift timing belt 34. Although the timing belt 34 and the like are used as the power transmission mechanism in this embodiment, it is also possible to use a mechanism using links.In other words, the structure is such that the weight on the rotating plate 28 side does not increase too much. It is desirable to have the same kind of humanity.

A lever 38 is integrally provided on the inner circumferential side of the rotating plate 28 and projects toward the center of curvature of the rotating plate 28. Fig. 6G shows the planar shape of the tip of this lever 38). As shown in FIG. 6 (6), which shows the cross-sectional structure taken along line B-B, a two-pronged fork-shaped bracket 39 is rotatably attached to the tip of the louver 38 via a bearing 40t. A ring-shaped body 41 is rotatably supported on the bracket 39 by a bearing 43 via a pair of pins 42t perpendicular to the lever 38.

As shown in FIG. 7, which shows the cross-sectional structure in the direction of the ■-■ arrow in FIG.
A holder 46, which holds 5 at a constant inclination, is removably fitted therein. A flange 48 is provided on a part of the outer periphery of the holder 46 to prevent the holder 46 from being removed from the body 41 by engaging a locking pawl 47 protruding from a part of the inner periphery of the body 41. The rotational phase t of the holder 46 with respect to the body 41 can be arbitrarily separated by adjusting the rotational phase t.
By using the so-called bayonet type, flaw detectors 45 having different inclination angles can be quickly replaced for each holder 46. The holder 46 is engaged with a rotation stopper 49 made of an elastic material attached to the body 41 so that the body 4
Engaging teeth 50 are provided in an arc shape along the outer periphery of the holder 46 to prevent rotation of the holder 460 times relative to the holder 1. By separating the rotation stopper 49t from the engagement teeth 50, the holder is 46 can be rotated. Note that when a plurality of flaw detectors with different inclination angles are all arranged in parallel on the holder 46 and any one of the flaw detectors is selectively used, the holder 46 may be integrated with the body 41 in advance. You can also leave it hanging. The holder 46, which has a convexly curved surface facing the pipe 11 to be inspected, has an ultrasonic propagation passage 5 communicating with the flaw detector 45.
1 is formed, and the pipe to be inspected 11 of this holder 46
A flexible thin film 52 that closes the opening of the ultrasonic propagation path 51 is mounted on the opposite surface.

The curvature of the surface of the holder 46 facing the pipe 11 to be inspected is the fourth
It is desirable to correspond to the minimum curvature of the curve 1 portion 53 of the pipe to be inspected 1.1 shown in FIG. Note that since this thin film 52 comes into sliding contact with the pipe to be inspected 11FC, it is desirable to use a durable member with a small coefficient of friction such as polyfluoroethylene resin. Further, a pair of reservoirs 54 communicating with the ultrasonic propagation path 51 are formed in the holder 46, and presser feet 1155' are also formed on the sides of the holder 46 where these reservoirs 54 open.
A flexible thin film 56 is attached to cover the opening of the reservoir 54 through the holder. A liquid 57 is contained in the ultrasonic propagation passage 51 and the reservoir 54 which are sealed by these thin films 52 and 56.
is filled with 1. The total cross-sectional area of these reservoirs 54 is set to be sufficiently larger (than the area of the opening of the ultrasonic propagation path 51),
This allows the thin film 56 to absorb elastic deformation of the thin film 520. The shape of the ultrasonic propagation path 51 is set to a conical shape in which the cross-sectional area of the thin film 52''tRll gradually increases so as not to adversely affect the flaw detection inspection. The guide plate 59 rotatably supported through the guide plate 59 rotates on an axis perpendicular to the bin 42, but has an arcuate shape with a curvature corresponding to the outer diameter of the pipe 11 to be inspected, and is in close contact with the pipe 11 to be inspected. It is now possible to do so.

Therefore, even if the tip end of the lever 38 is located at the bent pipe portion 53 of the pipe 11 to be inspected, as shown in the fourth row representing the working state of this embodiment, the spring force of the compression coil spring 20 The guide grate 59 that is pressed against the curved pipe portion 53 rotates the bracket 39 and the body 41 so that the contact state with the curved pipe portion 53 is most stable, and also rotates itself to contact the curved pipe portion 53. In close contact. As a result, the attitude of the flaw detector 45 with respect to the surface of the blood vessel section 530 can be maintained constant as in the case of the straight tube section 60, so that defect inspection of the welded joint section 61 can be performed accurately with high reproducibility. On the other hand, the thin film 525
Due to the elastic deformation of the thin film 6, the thin film 52 always follows the pipe 11 to be inspected while being in contact with the pipe 11 to be inspected, so there is no gap between the thin film 52 and the pipe 11 to be inspected, allowing for more accurate defect inspection. Is possible. On the other hand, when it is desired to change the direction of ultrasonic oscillation for the welded joint 61, the rotary plate drive motor is operated to rotate the transmission gear 36 that meshes with the drive gear 37 together with the timing pulley 33, and this rotational force is applied to the timing pulley 33. The transmission is transmitted via a belt 34 to a pinion 31 that is integrated with a timing pulley 32, and a gear 3 that meshes with this pinion 31.
The rotary plate 28 and the bushing 29 are rotated relative to the connecting block 23, thereby changing the direction of the flaw detector 45.
fr can be adjusted. The rotating position of the rotating plate 28, the reciprocating position of the rod 24 with respect to the support block 20, or the rotating position of the traveling carriage 13 with respect to the pipe to be inspected 11 are controlled by encoders attached to each drive motor or the like.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the external appearance of a conventional ultrasonic flaw detection device for piping, Fig. 2(a) is a conceptual diagram of the operation showing the state when the flaw detector is positioned in a curved pipe section, and Fig. ) is a sectional view taken along the line B-B, FIG. 3 is a perspective view showing the external appearance of an embodiment of the ultrasonic flaw detection device for piping according to the present invention, and FIG. 4-(a) is its working concept. 4 and 6) is a right side view of the traveling carriage, FIG. 5 is a plan view showing the structure of the main part of this embodiment, and FIG. 6(a) is an enlarged view of the flaw detector. 6) is a sectional view taken along arrow B-8, and FIG. 7 is a sectional view taken along arrows ■-■ in FIG. 6.
In the figure, 11 is the piping to be inspected, 12 is the band rail, 13 is the running trolley, 15 is the support, 18 is the trolley drive motor, 19.42 is the bin, 20 is the support block, 22 is the compression coil spring, 23 is the Connection block, 24 is a rod, 25 is a feed screw shaft, 26 is a feed nut, 27 is a rod drive motor, 28 is a rotating plate, 34 is a timing belt, 36 is a transmission gear, 37 is a drive gear, 38 Vi lever, 39 is a Bracket, 40, 43, 58 is a bearing, 41 is a body, 45 is a flaw detector, and 46 is a holder. Patent Applicant: Mitsubishi Heavy Industries, Ltd. Patent Attorney Shibe Mitsuishi (and 1 other person) Figure 1 Figure 2 (a) Figure 5 Figure 6, Figure 7 Figure 4

Claims (1)

[Claims] A traveling trolley that revolves around the piping to be inspected, a slider attached to the traveling trolley so as to be able to reciprocate in a direction parallel to the center of rotation of the traveling trolley, and a tip of the slider that is pressed against the piping to be inspected. An arcuate rotating plate supported rotatably around an axis perpendicular to the reciprocating direction of the slider, and a drive source provided at the base end of the slider 6 are connected to each other. a power transmission mechanism that rotates the rotating plate; a bracket that is rotatably attached to the tip of a lever that protrudes from the rotating plate in a direction perpendicular to the center of rotation thereof; An ultrasonic flaw detection device for piping, comprising: a body rotatably held by the bracket under an axial rotation force perpendicular to the center; and a holder integrally attached to the body and having an ultrasonic flaw detector attached thereto. .