JP2017219316A - Inspection method for peripheral weld zone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection method that makes it possible to determine whether inner surface beads in all peripheral weld zones have normal sizes.SOLUTION: The inspection method according to the present invention comprises: a preparation step of preparing a reference pipe P2 having the same outer diameter or inner diameter with that of a pipe P to be examined, fitting a first ring member 7 having a thickness meeting a determination criterion to an inner surface of the reference pipe, and generating a first reference image as an X-ray image of the reference pipe using an X-ray inspection machine; an inspection step of generating an inspection image as an X-ray image of the pipe P1 to be examined; and a determination step of determining whether a peripheral weld zone of the pipe to be examined is normal using the first reference image and inspection image. In the determination step, the inspection image is compared with the first reference image and it is determined that inner surface beads have normal sizes at the peripheral weld zone when the radial position of a pixel region corresponding to a top part of the inner surface beads at the peripheral weld zone in the inspection image is at the same position with or radially outside a radial position of a pixel region corresponding to an inner surface of the first ring member in the first reference image, and it is determined that the beads have defective sizes when radially inside.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for inspecting a circumferential weld formed to connect ends of a plurality of tubes. In particular, the present invention relates to an inspection method that can determine the quality of the inner surface bead of a circumferential welded part.

  Conventionally, as disclosed in Patent Document 1, a tube wound around a reel called coiled tubing is known. For example, the coiled tubing is unwound from a reel at sea and lowered to a well such as a subsea oil field or a subsea gas field. Coiled tubing is used, for example, as an umbilical cable that functions as a control line that connects an offshore host facility and a subsea well. The umbilical cable includes an electric wire, a high-pressure hydraulic hose, an optical cable, and the like.

  Coiled tubing wound on one reel is generally a long tube exceeding 3000 feet. Therefore, coiled tubing is formed by circumferential welding between the ends of a plurality of tubes. Long tubes are widely used.

  One of the inspection items for the circumferential weld formed on the long pipe as described above is the dimension of the inner surface bead. Specifically, if the distance between the inner surface of the pipe called a route and the top of the inner surface bead of the circumferential welded portion (see FIG. 4A) exceeds a predetermined criterion (for example, 0.8 mm), The dimension of the inner surface bead of the circumferential weld is determined to be defective. This is because if the route is large, there may be a problem in inserting an electric wire or the like into a long tube such as an umbilical cable.

  Conventionally, the above route does not inspect the total number of circumferential welds formed on the long pipe, but determines the quality by offline observation of a sample obtained by cutting the vicinity of the circumferential welds. In other words, since only a sampling inspection is performed, the inspection is not necessarily sufficient. For this reason, an inspection method capable of determining all the routes of the peripheral welds online is desired.

For example, methods disclosed in Patent Documents 2 and 3 are known as methods for inspecting a welded portion of a welded pipe such as a UO pipe or an electric resistance welded pipe.
The method described in Patent Document 2 is a method of optically measuring the outer surface bead height of a welded portion with an optical gap sensor. To apply this method to the route of a circumferential welded portion, an optical gap sensor or its Since it is necessary to insert the drive mechanism into the pipe, it is difficult to inspect all the circumferential welds of the long pipe.

  In the method described in Patent Document 3, an X-ray source that emits X-rays toward a welded pipe, and a position that faces the X-ray source across the welded pipe and is emitted from the X-ray source and welded pipe This is a method for inspecting a welded portion of a welded pipe using an X-ray inspection machine including an X-ray detector that detects X-rays transmitted through the X-ray. If the method of patent document 3 is applied to the test | inspection of a circumference welding part, it will be thought that the inner surface bead of a circumference welding part can be visualized. However, Patent Document 3 describes the detection of defects (microcracks) in the welded part, but the disclosure also suggests that the quality of the route of the peripheral welded part is determined using an X-ray inspection machine. There is no.

International Publication No. 1998/31499 JP 59-112210 A JP 58-117445 A

  An object of the present invention is to provide an inspection method capable of determining the quality of the inner surface bead of the circumferential welded portion.

In order to solve the above problems, the present inventors have intensively studied. As a result, a reference tube having the same outer diameter and inner diameter as the tube to be inspected is prepared, and the inner surface of the reference tube has a thickness corresponding to the criterion of the route. By attaching a ring member to generate an X-ray image and comparing this with the X-ray image generated for the tube to be inspected, it is possible to determine the quality of the route of the circumferential welded portion of the tube to be inspected with relatively high accuracy. As a result, the present invention was completed.
That is, in order to solve the above-mentioned problem, the present invention is arranged in an X-ray source that emits X-rays toward the tube to be inspected, and a position facing the X-ray source across the tube to be inspected. A peripheral welded portion of the inspection tube is inspected using an X-ray inspection machine including an X-ray image detector that detects X-rays emitted from the radiation source and transmitted through the inspection tube and generates an X-ray image. A reference pipe having the same outer diameter and inner diameter as the pipe to be inspected is prepared, and a first ring member having an outer diameter substantially the same as the inner diameter of the reference pipe and having a thickness according to a judgment criterion is provided. A preparatory step for generating a first reference image, which is an X-ray image of the reference tube including the first ring member, using the X-ray inspection machine, attached to the inner surface of the reference tube, and using the X-ray inspection machine An inspection step of generating an inspection image that is an X-ray image of the inspection tube including the circumferential weld; A determination step of determining the quality of the peripheral weld of the tube to be inspected using the first reference image and the inspection image, wherein the determination step corresponds to the inner surface of the tube to be inspected in the inspection image. When the inspection image and the first reference image are compared by matching the radial position of the pixel region to be matched with the radial position of the pixel region corresponding to the inner surface of the reference tube in the first reference image The radial position of the pixel region corresponding to the top of the inner surface bead of the circumferential weld in the inspection image is the radial position of the pixel region corresponding to the inner surface of the first ring member in the first reference image. If it is the same or radially outside, the circumferential weld is determined to have good inner bead dimensions, and the radial position of the pixel region corresponding to the top of the inner bead of the circumferential weld in the inspection image is , The first reference in the first reference image. An inspection method for a circumferential welded portion, wherein the circumferential welded portion is determined to have a bad dimension of the inner surface bead if it is radially inward from a radial position of a pixel region corresponding to the inner surface of the gripping member I will provide a.

According to the method for inspecting a circumferential weld according to the present invention, in the preparation step, a first ring member having a thickness corresponding to a determination criterion (route determination criterion) is attached to the inner surface, and the tube to be inspected, the outer diameter, A first reference image that is an X-ray image of a reference tube having the same inner diameter is generated.
Further, in the inspection process, an inspection image that is an X-ray image of a tube to be inspected that is an actual inspection object is generated.
Further, in the determination step, the radial position of the pixel region corresponding to the inner surface of the inspection tube in the inspection image is matched with the radial position of the pixel region corresponding to the inner surface of the reference tube in the first reference image. The inspection image and the first reference image are compared. In order to compare the inspection image and the first reference image in a state where the radial position of the pixel region corresponding to the inner surface of the tube to be inspected matches the radial position of the pixel region corresponding to the inner surface of the reference tube, The inner route (distance between the radial position of the pixel region corresponding to the inner surface of the tube to be inspected and the radial position of the pixel region corresponding to the top of the inner surface bead) is determined based on the determination reference (reference tube of the reference tube). It is relatively easy to determine whether or not the distance between the radial position of the pixel region corresponding to the inner surface and the radial position of the pixel region corresponding to the inner surface of the first ring member is exceeded.
That is, in the determination step, the radial position of the pixel region corresponding to the top of the inner surface bead in the inspection image is the same as or the same as the radial position of the pixel region corresponding to the inner surface of the first ring member in the first reference image. If it is outside in the direction, it is possible to determine that the peripheral weld has a good inner bead size (the route is not more than the criterion). On the other hand, if the radial position of the pixel region corresponding to the top of the inner surface bead in the inspection image is radially inward from the radial position of the pixel region corresponding to the inner surface of the first ring member in the first reference image. It is possible to determine that the circumferential weld has a defective inner bead size (the route exceeds the criterion).
According to the present invention, since it can be determined relatively easily only by comparing the first reference image and the inspection image, it is possible to determine the quality of the dimensions of the inner surface bead of the circumferential welded portion.
In the present invention, the “radial position” means a position in a direction corresponding to the radial direction of the test tube and the reference tube. The “radially outer side” means a side corresponding to the side opposite to the central axis side of the tube to be inspected and the reference tube. Furthermore, “inward in the radial direction” means a side corresponding to the central axis side of the tube to be inspected and the reference tube.

  Another inspection item of the circumferential weld is the dimension of the outer bead. Specifically, if the distance (see FIG. 4A) between the outer surface of the tube to be inspected called a cap and the top of the outer surface bead of the circumferential welded portion exceeds a predetermined criterion (for example, 0.8 mm). The dimensions of the outer bead of the circumferential weld are determined to be poor. Since the quality of the cap can be determined from the outer surface side of the tube to be inspected, it is also conceivable to apply a method of optical measurement as described in Patent Document 2, for example. However, it is preferable that the X-ray inspection machine used for determining the quality of the route is also used for the quality of the cap because the cost of the inspection apparatus can be reduced.

  That is, preferably, in the preparation step, a second ring member having an inner diameter substantially the same as the outer diameter of the reference tube and having a thickness corresponding to a determination criterion is attached to the outer surface of the reference tube, and the X-ray inspection is performed. A second reference image that is an X-ray image of the reference tube including the second ring member using a machine, and in the determination step, a pixel region corresponding to an outer surface of the inspection tube in the inspection image The inspection image is compared with the inspection image and the second reference image by matching the radial position with the radial position of the pixel region corresponding to the outer surface of the reference tube in the second reference image. The radial position of the pixel region corresponding to the top of the outer surface bead of the circumferential weld is the same as or radial direction of the radial position of the pixel region corresponding to the outer surface of the second ring member in the second reference image. If inside, the circumference The contact portion determines that the size of the outer surface bead is good, and the radial position of the pixel region corresponding to the top of the outer surface bead of the circumferential welded portion in the inspection image is the second position in the second reference image. If it is radially outer than the radial position of the pixel region corresponding to the outer surface of the ring member, the circumferential weld portion determines that the outer bead has a defective dimension.

According to the preferable method, in the preparation step, the second ring member having a thickness corresponding to the determination criterion (cap determination criterion) is attached to the outer surface, and the reference tube has the same outer diameter and inner diameter as the tube to be inspected. A second reference image that is an X-ray image is generated.
In the determination step, the radial position of the pixel region corresponding to the outer surface of the inspection tube in the inspection image is matched with the radial position of the pixel region corresponding to the outer surface of the reference tube in the second reference image. The inspection image and the second reference image are compared. In order to compare the inspection image and the second reference image in a state where the radial position of the pixel region corresponding to the outer surface of the tube to be inspected matches the radial position of the pixel region corresponding to the outer surface of the reference tube, The inner cap (the distance between the radial position of the pixel region corresponding to the outer surface of the tube to be inspected and the radial position of the pixel region corresponding to the top of the outer surface bead) is determined according to the determination reference (reference tube of the reference tube). It is relatively easy to determine whether or not the distance between the radial position of the pixel region corresponding to the outer surface and the radial position of the pixel region corresponding to the outer surface of the second ring member is exceeded.
That is, in the determination step, the radial position of the pixel region corresponding to the top of the outer surface bead in the inspection image is the same as or the same as the radial position of the pixel region corresponding to the outer surface of the second ring member in the second reference image. If it is inside in the direction, it is possible to determine that the peripheral weld has a good dimension of the outer bead (the cap is equal to or less than the criterion). On the other hand, if the radial position of the pixel region corresponding to the top of the outer bead in the inspection image is radially outer than the radial position of the pixel region corresponding to the outer surface of the second ring member in the second reference image. It is possible to determine that the peripheral weld has a defective outer bead size (cap exceeds the criterion).
According to the above preferred method, since it can be determined relatively easily only by comparing the second reference image and the inspection image, it is possible to determine the total quality of the dimensions of the outer surface bead of the circumferential weld.

  As another inspection item of the circumferential welded portion, alignment can be cited. Specifically, if the distance between both outer surfaces (see FIG. 4 (a)) sandwiching the circumferential weld of the tube to be inspected called misalignment exceeds a predetermined criterion (for example, 0.3 mm), The alignment of the circumferential weld is determined to be poor. Since the quality of the alignment can also be determined from the outer surface side of the tube to be inspected, it is also conceivable to apply an optical measurement method as described in Patent Document 2, for example. However, it is preferable that the X-ray inspection machine used for determining the quality of the route is used for the quality of the alignment because the cost of the inspection apparatus can be reduced.

  That is, preferably, in the preparation step, a third ring member having an inner diameter substantially the same as the outer diameter of the reference tube and having a thickness corresponding to a determination criterion is attached to the outer surface of the reference tube, and the X-ray inspection is performed. A third reference image, which is an X-ray image of the reference tube including the third ring member, is generated using a machine, and in the determination step, both peripheral welds of the inspection tube in the inspection image are sandwiched The radial position of the pixel region corresponding to one outer surface located on the radially inner side of the outer surface is matched with the radial position of the pixel region corresponding to the outer surface of the reference tube in the third reference image, When the inspection image and the third reference image are compared, a pixel region corresponding to the other outer surface located on the outer side in the radial direction among both outer surfaces sandwiching the circumferential welded portion of the tube to be inspected in the inspection image. The radial direction position is the third reference image. If it is the same as the radial position of the pixel region corresponding to the outer surface of the third ring member in the inside or the inside in the radial direction, the circumferential weld is determined to have good alignment, and the inspected in the inspection image If the radial position of the pixel region corresponding to the other outer surface of the tube is radially outer than the radial position of the pixel region corresponding to the outer surface of the third ring member in the third reference image, The circumferential weld is determined to have poor alignment.

According to the preferable method described above, in the preparation step, the third ring member having a thickness corresponding to the determination criterion (misalignment determination criterion) is attached to the outer surface, and the reference tube has the same outer diameter and inner diameter as the tube to be inspected. A third reference image that is an X-ray image of is generated.
In the determination step, the radial position of the pixel region corresponding to one outer surface located on the radially inner side of both outer surfaces sandwiching the circumferential welded portion of the test tube in the inspection image, and the third reference image The inspection image and the third reference image are compared by matching the radial position of the pixel region corresponding to the outer surface of the reference tube. In a state where the radial position of the pixel region corresponding to one outer surface located on the radially inner side of the inspection tube matches the radial position of the pixel region corresponding to the outer surface of the reference tube, the inspection image and the third reference In order to compare the images, misalignment in the inspection image (the radial position of the pixel region corresponding to one outer surface located on the inner side in the radial direction of the tube to be inspected and the pixel corresponding to the other outer surface located on the outer side in the radial direction) The distance from the radial position of the region is a criterion in the third reference image (the radial position of the pixel region corresponding to the outer surface of the reference tube) and the radial position of the pixel region corresponding to the outer surface of the third ring member. It is relatively easy to determine whether or not the distance is exceeded.
That is, in the determination step, a pixel corresponding to the outer surface of the third ring member in the third reference image has a radial position in the pixel region corresponding to the other outer surface located on the outer side in the radial direction of the tube to be inspected in the inspection image. If it is the same as the radial position of the region or radially inward, it is possible to determine that the circumferential weld is well aligned (misalignment is equal to or less than the criterion). On the other hand, the radial position of the pixel region corresponding to the other outer surface located on the radially outer side of the inspection tube in the inspection image is the radial direction of the pixel region corresponding to the outer surface of the third ring member in the third reference image. If it is radially outward from the position, it is possible to determine that the circumferential weld is poorly aligned (misalignment exceeds the criterion).
According to the preferable method described above, since it is possible to determine relatively easily only by comparing the third reference image and the inspection image, it is possible to determine the total quality of the alignment of the circumferential welded portion.
In addition, the 3rd ring member used with said preferable method is attached to the outer surface of a reference | standard pipe | tube similarly to the above-mentioned 2nd ring member. For this reason, it is also possible to form the third ring member integrally with the second ring member.

  According to the present invention, it is possible to determine the total quality of the dimensions of the inner surface bead of the circumferential weld.

FIG. 1 is a plan view schematically showing a schematic configuration of a long pipe manufacturing facility to which a method for inspecting a circumferential weld according to an embodiment of the present invention is applied. FIG. 2 is a diagram schematically showing a schematic configuration of an X-ray inspection machine provided in the X-ray inspection apparatus main body shown in FIG. FIG. 3 is a diagram schematically showing a schematic configuration of the X-ray leakage suppression mechanism shown in FIG. FIG. 4 is a diagram schematically showing a schematic configuration of a target to be judged by the circumferential welded portion inspection method according to an embodiment of the present invention and a ring member used to judge the quality of each target. FIG. 5 is an explanatory diagram for explaining a quality determination method for the route of the circumferential welded portion, which is executed by the image processing apparatus shown in FIG. FIG. 6 is an explanatory diagram for explaining a method for determining whether or not the cap of the circumferential welded portion is executed by the image processing apparatus shown in FIG. FIG. 7 is an explanatory view illustrating a method for determining the quality of alignment of the circumferential welded portion, which is executed by the image processing apparatus shown in FIG. FIG. 8 is a plan view for explaining the movement of the welding apparatus and the X-ray inspection apparatus according to the procedure executed by the control apparatus shown in FIG. FIG. 9 is a plan view for explaining the movement of the welding apparatus and the X-ray inspection apparatus according to the procedure executed by the control apparatus shown in FIG. FIG. 10 is a plan view for explaining the movement of the welding apparatus and the X-ray inspection apparatus according to the procedure executed by the control apparatus shown in FIG. FIG. 11 is a plan view for explaining the movement of the welding apparatus and the X-ray inspection apparatus according to the procedure executed by the control apparatus shown in FIG. FIG. 12 is a plan view for explaining the movement of the welding apparatus and the X-ray inspection apparatus according to the procedure executed by the control apparatus shown in FIG. FIG. 13 is a plan view for explaining the movement of the welding apparatus and the X-ray inspection apparatus according to the procedure executed by the control apparatus shown in FIG.

Hereinafter, a method for inspecting a circumferential weld according to an embodiment of the present invention will be described with reference to the accompanying drawings, taking as an example a case where the method is applied to a long pipe manufacturing facility such as coiled tubing. First, the overall configuration of the manufacturing facility will be described.
FIG. 1 is a plan view schematically showing a schematic configuration of a long pipe manufacturing facility to which the method for inspecting a circumferential weld according to the present embodiment is applied.
As shown in FIG. 1, a long tube manufacturing facility (hereinafter simply referred to as “manufacturing facility”) 100 according to the present embodiment includes a conveying device 1, a welding device 2, a winding device 3, and an X A line inspection device 4. In addition, the manufacturing facility 100 according to the present embodiment includes a control device 5 that controls operations of the transport device 1, the welding device 2, the winding device 3, and the X-ray inspection device 4. Furthermore, the manufacturing facility 100 according to the present embodiment includes a carry-in table 6 on which a plurality of pipes P are placed.
In the manufacturing facility 100 according to the present embodiment, as a preferable configuration, the welding device 2 and the X-ray inspection device 4 can be moved separately along the transport device 1. That is, the welding apparatus 2 and the X-ray inspection apparatus 4 can be moved separately from each other along the conveying direction of the pipe P (longitudinal direction of the pipe P). Specifically, for example, the welding device 2 and the X-ray inspection device 4 are each attached to a drive device (not shown) such as an air cylinder, and wheels (not shown) are respectively attached to the lower part. Yes. In addition, rails (not shown) are provided on the floor surface along the conveyance direction of the pipe P. By driving the drive device by the control device 5, the welding device 2 and the X-ray inspection device 4 can move independently of each other along the transport device 1 by rolling the respective wheels on the rail. ing. Therefore, as described later, when the X-ray inspection device 4 determines that the peripheral weld is defective, it is not necessary to drive the transport device 1 and the winding device 3 in the reverse direction. For example, if the distance between the welding apparatus 2 and the X-ray inspection apparatus 4 is adjusted according to the length of the pipe P to be circumferentially welded and set to a distance substantially equal to the length of the pipe P, the welding apparatus It is also possible to increase the manufacturing efficiency by performing the circumferential welding by 2 and the circumferential welded portion by the X-ray inspection apparatus 4 in parallel.

  The pipe P of the present embodiment is, for example, a stainless steel pipe. When the long pipe P1 formed by circumferential welding of the pipe P by the welding apparatus 2 is used as an umbilical cable, preferably two pipes are used. Phase stainless steel pipe. The pipe P may be an electric sewing pipe or a seamless pipe.

  The transport device 1 is a device that is driven by the control device 5 and transports the pipe P in a straight line in the longitudinal direction (X direction shown in FIG. 1). Specifically, in the present embodiment, a plurality of tubes P placed on the carry-in table 6 are sequentially carried in the direction (Y direction shown in FIG. 1) perpendicular to the longitudinal direction toward the transfer device 1 and transferred. The apparatus 1 conveys the several pipe | tube P carried in to a longitudinal direction. The carry-in table 6 includes a predetermined carry-in mechanism (not shown), and a plurality of pipes P are sequentially carried in by the carry-in mechanism being driven by the control device 5.

The transport device 1 of this embodiment includes a side clamp roller 11 and a V roller 12.
The side clamp roller 11 is disposed so as to sandwich the pipe P in the horizontal direction on the upstream side in the conveyance direction (X direction) of the pipe P with respect to the welding apparatus 2. The side clamp roller 11 applies a driving force in the longitudinal direction of the pipe P by rotating using a motor or the like as a driving source.
The V roller is arranged below the pipe P (including the long pipe P1) between the position where the pipe P is carried from the carry-in table 6 and the winding device 3. The V roller supports the pipe P from below and rotates as the pipe P is conveyed in the longitudinal direction.
With the above configuration, the tube P before being circumferentially welded by the welding device 2 and the long tube P1 before being wound around the reel 31 by the winding device 3 are driven by the side clamp roller 11 in the longitudinal direction. The long tube P1 that has been applied and wound on the reel 31 by the winding device 3 is given a driving force in the longitudinal direction by the winding device 3, and is transported in the longitudinal direction.
In addition, although this embodiment demonstrated the structure which comprises the side clamp roller 11 which provides a driving force, and the V roller 12 which only follows, without providing a driving force, as the conveying apparatus 1, It restricts to this. It is not a thing. As the transport device, for example, a pusher that pushes the pipe P from the upstream side to the downstream side in the transport direction can be used instead of the side clamp roller 11 and various configurations can be adopted as long as the pipe P can be transported in the longitudinal direction. is there.

The welding device 2 is disposed along the transport device 1. The welding device 2 is a device that is driven by the control device 5 and that performs circumferential welding on the ends of a plurality of pipes P conveyed by the conveying device 1 to form a long pipe P1.
The welding apparatus 2 of the present embodiment includes a circumferential welder (circumferential welder) 21 and a pair of gripping devices disposed along the conveying direction of the pipe P (longitudinal direction of the pipe P) with the circumferential welder 21 interposed therebetween. 22. Moreover, the welding apparatus 2 of this embodiment also includes a cooling device (not shown). As a cooling method of the cooling device, for example, forced air cooling can be exemplified.

  The control device 5 stops the operations of the conveying device 1 and the winding device 3 and drives each gripping device 22 at the timing when the end of each pipe P arrives at the position where the circumferential welding machine 21 is arranged. As a result, each gripping device 22 grips the end of each pipe P. That is, the tip of the pipe P positioned upstream in the transport direction is gripped by the gripping device 22 disposed on the upstream side in the transport direction of the pipe P, and downstream in the transport direction by the gripping device 22 disposed on the downstream side in the transport direction. The rear end portion of the pipe P (long pipe P1) is gripped. And each holding | grip apparatus 22 adjusts the position of each pipe | tube P so that the axial center of each pipe | tube P may correspond. Next, the control device 5 drives the circumferential welder 21, and the circumferential welder 22 performs circumferential welding on the ends of the pipes P whose positions have been adjusted. Finally, the control device 5 drives the cooling device, and the cooling device cools the formed circumferential weld PW. After the cooling of the circumferential weld PW is completed, the control device 5 releases the gripping by each gripping device 22, drives the transport device 1 and the winding device 3, and transports the long tube P1.

The winding device 3 is arranged along the conveying device 1 on the downstream side in the conveying direction of the pipe P (long pipe P1) with respect to the welding device 2. The winding device 3 is a device that is driven by the control device 5 and winds the long tube P <b> 1 conveyed by the conveying device 1 around the reel 31.
Specifically, the winding device 3 of the present embodiment includes a rotation mechanism (not shown) that rotates the reel 31 around its central axis, and a moving mechanism that moves the reel 31 in the central axis direction (Y direction). (Not shown). The winding device 3 rotates the reel 31 by a rotating mechanism and moves the reel 31 by a moving mechanism, thereby winding the long tube P <b> 1 on the outer surface of the reel 31.

The X-ray inspection apparatus 4 is an apparatus for executing the inspection method of the circumferential weld PW according to one embodiment of the present invention. The X-ray inspection device 4 is disposed between the welding device 2 and the winding device 3 along the transport device 1. The X-ray inspection device 4 is driven by the control device 5 and inspects the circumferential weld PW of the long pipe P1.
The control device 5 is configured such that the circumferential weld portion PW of the long pipe P1 formed by the welding device 2 is disposed at the position where the X-ray inspection device 4 is disposed (specifically, the position where X-rays are emitted by the X-ray source 412 described later). ), The long tube P1 is stopped by stopping the operations of the transport device 1 and the winding device 3, and the X-ray inspection device 4 is driven.

The X-ray inspection apparatus 4 includes an X-ray inspection apparatus main body 41 and an X-ray leakage suppression mechanism 42 attached in the vicinity of the entrance and exit openings of the X-ray inspection apparatus main body 41. In the X-ray inspection apparatus main body 41, the long pipe P1 has openings on the entry side (upstream side in the conveyance direction of the long pipe P1) and the exit side (downstream direction in the conveyance direction of the long pipe P1) of the X-ray inspection apparatus main body 41. The circumferential weld PW of the long pipe P1 is inspected in a state protruding from the outside. While the X-ray inspection apparatus body 41 is inspecting the peripheral weld PW of the long pipe P1 by the X-ray inspection apparatus body 41, the X-ray leakage suppression mechanism 42 is connected to the outside from the entrance and exit openings of the X-ray inspection apparatus body 41. Suppresses X-ray leakage.
Hereinafter, a more specific configuration of the X-ray inspection apparatus 4 will be described with reference to FIGS. 2 and 3 as appropriate.

  As shown in FIG. 1, the X-ray inspection apparatus main body 41 includes a housing 41a, a pair of sleeves 41b that are respectively provided on the entrance side and the exit side of the housing 41a, and communicates with the housing 41a. And an X-ray inspection machine 41c arranged at the same position. This X-ray inspection machine 41c is an X-ray inspection machine used for executing the inspection method of the circumferential weld PW according to one embodiment of the present invention. The X-ray inspection apparatus main body 41 has the long tube P1 circumferentially welded to the long tube P1 by the X-ray inspection device 41c in a state where the long tube P1 is inserted into the X-ray inspection device 41c and each sleeve 41b disposed in the housing 41a. Inspect part PW.

FIG. 2 is a diagram schematically illustrating a schematic configuration of an X-ray inspection machine 41 c included in the X-ray inspection apparatus main body 41. 2A is a perspective view, and FIG. 2B is a front view of the long pipe P1 as viewed from the longitudinal direction.
As shown in FIG. 2, the X-ray inspection machine 41 c includes a rotation mechanism unit 411, an X-ray source 412, an X-ray image detector 413, and an image processing device 414.

The rotation mechanism unit 411 includes, for example, an outer ring member 411A that surrounds the circumference of the long pipe P1, and an inner ring member 411B that is attached to the inner side of the outer ring member 411A so as to be rotatable with respect to the outer ring member 411A. It comprises.
The X-ray source 412 is a device that emits X-rays toward a long tube P1 that is a tube to be inspected. The X-ray source 412 is attached to the inner ring member 411B of the rotation mechanism unit 411, and rotates around the circumferential direction of the long tube P1 when the inner ring member 411B rotates with respect to the outer ring member 411A. As shown in FIG. 2B, the X-ray source 412 repeats rotation and stop, and X-rays are obtained at a plurality of predetermined positions (in the example shown in FIG. 2B, three positions with a 60 ° pitch). Radiate.
The X-ray image detector 413 is disposed at a position facing the X-ray source 412 across the long tube P1, detects X-rays emitted from the X-ray source 412 and transmitted through the long tube P1, and X-rays are detected. For example, a flat panel detector (FPD) is preferably used. The X-ray image detector 413 is also attached to the inner ring member 411B of the rotation mechanism unit 411, and the inner ring member 411B rotates relative to the outer ring member 411A, so that the X-ray image detector 413 is integrated with the X-ray source 412 (the long tube P1). (While maintaining a state of being opposed to the X-ray source 412 across the tube) and rotating around the circumferential direction of the long tube P1.
The image processing device 414 is a device that performs image processing on the X-ray image generated by the X-ray image detector 413 and inspects the circumferential weld PW of the long tube P1. The image processing device 414 determines the quality of the inner surface bead size or the like of the peripheral weld PW by executing the inspection method of the peripheral weld PW according to the embodiment of the present invention. Specific contents of this determination will be described later. In addition, the image processing apparatus 414 extracts, for example, a pixel area having a high pixel density (for example, porosity) as a defect area (for example, porosity) by performing image processing on an X-ray image, and the area of the extracted defect area It is also possible to determine the quality of the circumferential welded part PW by evaluating the size of.

FIG. 3 is a diagram schematically illustrating a schematic configuration of the X-ray leakage suppression mechanism 42. 3A is a front view showing a state of the X-ray leakage suppression mechanism 42 when the peripheral weld PW of the long pipe P1 is inspected by the X-ray inspection apparatus main body 41, and FIG. 3B is FIG. The bb arrow sectional drawing of (a) is shown. FIG. 3C shows the state of the X-ray leakage suppression mechanism 42 when the inspection of the circumferential weld PW of the long pipe P1 is completed by the X-ray inspection apparatus main body 41 and the long pipe P1 is transferred by the transfer apparatus 1. FIG. 3 (d) is a sectional view taken along the arrow dd in FIG. 3 (c).
As described above, the X-ray leakage suppression mechanism 42 is attached to the vicinity of the entrance and exit openings of the X-ray inspection apparatus main body 41. Specifically, the X-ray leakage suppression mechanism 42 is attached in the vicinity of the substantially circular opening 410 included in the pair of sleeves 41 b included in the X-ray inspection apparatus main body 41. More specifically, the X-ray leakage suppression mechanism 42 is located in the vicinity of the opening 410 on the upstream side with respect to the sleeve 41b provided on the upstream side in the transport direction of the long tube P1 out of the pair of sleeves 41b. The sleeve 41b that is attached and provided on the downstream side in the transport direction of the long pipe P1 is attached in the vicinity of the opening 410 on the downstream side. Since each X-ray leakage suppression mechanism 42 attached to the entrance side and the exit side of the X-ray inspection apparatus main body 41 has the same configuration, only one X-ray leakage suppression mechanism 42 will be described here.

The X-ray leakage suppression mechanism 42 includes a closing member 421. The closing member 421 includes a plurality of members (in the example shown in FIG. 3, two half-divided members 42a and 42b) that can be opened and closed in the radial direction (the radial direction of the long tube P1), and the plurality of members 42a. , 42b is in a radially closed position (the state shown in FIGS. 3A and 3B), a substantially circular opening 421a into which the long tube P1 is inserted is formed inside. Specifically, each member 42a, 42b is attached to a drive device (not shown) such as an air cylinder, and by driving this drive device, each member 42a, 42b is in the radial direction (FIG. 3). In the example shown in FIG. 2, the opening and closing is possible (up and down movement). The members 42a and 42b constituting the closing member 421 are made of, for example, stainless steel.
In the example shown in FIG. 3, the members 42a and 42b can be opened and closed in the vertical direction. However, the present invention is not limited to this, and the radial direction of the long pipe P1 (in the longitudinal direction of the long pipe P1). It is also possible to use a member that can be opened and closed in another direction such as a horizontal direction as long as the direction is orthogonal. In the example shown in FIG. 3, the closing member 421 includes two members 42 a and 42 b. However, the closing member 421 is not limited to this, and as long as it is a plurality of members that can be opened and closed in the radial direction, It is also possible to comprise from the above members.

  When the peripheral weld PW of the long pipe P1 is inspected by the X-ray inspection apparatus main body 41 (that is, when X-rays are radiated from the X-ray source 412), the control device 5 is shown in FIG. As shown in b), the X-ray leakage suppression mechanism 42 is driven so that the plurality of members 42a and 42b constituting the closing member 421 are in a radially closed position. That is, when a drive device such as an air cylinder included in the X-ray leakage suppression mechanism 42 is driven by a control signal from the control device 5, the plurality of members 42 a and 42 b are in a radially closed position. As shown in FIGS. 3A and 3B, when the plurality of members 42a and 42b are in the radially closed position, the radial dimension L1 of the opening 421a of the closing member 421 is determined by X-ray inspection. It is smaller than the radial dimension L2 (the radial dimension of the opening 410 of the sleeve 41b, see FIG. 3C) of the opening on the entry side and the exit side of the apparatus main body 41. Accordingly, a part of the opening of the X-ray inspection apparatus main body 41 (a part of the opening 410 of the sleeve 41b) is closed by the closing member 421 (a plurality of members 42a and 42b). When the plurality of members 42a and 42b are in the radially closed position, the radial dimension L1 of the opening 421a of the closing member 421 is substantially the same as the radial dimension of the long pipe P1 other than the circumferential weld PW. It is. Accordingly, the gap between the opening 421a of the closing member 421 and the long tube P1 is eliminated or extremely small. For this reason, if the circumferential welded part PW of the long tube P1 is inspected by the X-ray inspection apparatus main body 41 after the plurality of members 42a and 42b reach the radially closed position, the opening of the X-ray inspection apparatus main body 41 is opened. It is possible to suppress leakage of X-rays from the portion (opening portion 410 of the sleeve 41b) to the outside.

  On the other hand, the control device 5 finishes the inspection of the circumferential weld P1 of the long tube P1 by the X-ray inspection device main body 41 (that is, the X-ray emission from the X-ray source 412 stops), and the conveying device 1 When transporting the long tube P1, as shown in FIGS. 3C and 3D, X-ray leakage is performed so that the plurality of members 42a and 42b constituting the closing member 421 are in the radially open position. The suppression mechanism 32 is driven. As shown in FIGS. 3C and 3D, when the plurality of members 42a and 42b are in the radially open position, the closing member 421 does not interfere with the circumferential weld PW of the long pipe P1. Is in position. In the present embodiment, the plurality of members 42a and 42b constituting the closing member 421 are positioned radially outward from the sleeve 41b. For this reason, even if the long tube P1 is transported after the X-ray inspection in the X-ray inspection apparatus main body 41 is completed, there is no possibility that the circumferential welded portion PW of the long tube P1 interferes with the closing member 421. Will not cause any problems.

  In order to further suppress the leakage of X-rays, as shown in FIG. 1, a pair of X-ray leakage suppression mechanisms 42A having the same configuration as the X-ray leakage suppression mechanism 42 is attached in the housing 41a. preferable. Of the pair of sleeves 41b, the X-ray leakage suppression mechanism 42A is attached to the sleeve 41b provided on the upstream side in the transport direction of the long tube P1 in the vicinity of the opening 410 on the downstream side. The sleeve 41b provided on the downstream side in the conveyance direction of P1 is attached in the vicinity of the opening 410 on the upstream side.

  When the peripheral weld PW of the long pipe P1 is inspected by the X-ray inspection apparatus 4 described above and it is determined that the peripheral weld PW is normal, the control device 5 controls the transport device 1 and the winding device 3. By driving, the long tube P <b> 1 is conveyed and wound on the reel 31.

  On the other hand, when it is determined by the X-ray inspection apparatus 4 that the circumferential weld PW of the long pipe P1 is defective, the welding apparatus 2 and the X-ray inspection apparatus 4 are connected to each other along the transport apparatus 1 as described above. Since the control device 5 can move separately, the control device 5 does not drive the transport device 1 and the winding device 3 in the reverse direction (without transporting the long pipe P1 in the reverse direction). It is possible to form the circumferential weld PW again on the long tube P1 and inspect the circumferential weld PW formed again by the X-ray inspection apparatus 4. A specific operation example of the control device 5 when it is determined that the circumferential weld PW of the long pipe P1 is defective will be described later.

  Hereinafter, an inspection method for the circumferential weld PW according to an embodiment of the present invention will be described with reference to FIGS. 4 to 7 as appropriate. As described above, the inspection method of the circumferential weld PW according to the present embodiment is a long tube that is an inspection tube using the X-ray inspection machine 41c including the X-ray source 412 and the X-ray image detector 413. This is a method for inspecting the circumferential weld PW of P1.

FIG. 4 is a diagram schematically illustrating a schematic configuration of a target for determining pass / fail by the inspection method of the circumferential weld PW according to the present embodiment and a ring member used for determining pass / fail of each target. FIG. 4A shows an object for determining pass / fail, and FIG. 4B shows a schematic configuration of the ring member.
As shown to Fig.4 (a), in the inspection method of the circumference welding part PW which concerns on this embodiment, the distance (long) of the inner surface of the long pipe P1 called a root | route and the top part of the inner surface bead of the circumference welding part PW The quality of the distance in the radial direction of the canal P1 is determined. Moreover, in this embodiment, as a preferable aspect, the quality of the distance (distance about the radial direction of the long pipe P1) of the outer surface of the long pipe P1 called a cap and the top part of the outer surface bead of the circumferential welding part PW is also good. It is a judgment target. Furthermore, in the present embodiment, as a preferred mode, alignment according to the distance between both outer surfaces (distance in the radial direction of the long pipe P1) sandwiching the circumferential weld PW of the long pipe P1 called misalignment. The quality is also determined.

  The inspection method for the circumferential weld PW according to the present embodiment includes a preparation process, an inspection process, and a determination process. Hereinafter, each process will be described sequentially.

<Preparation process>
As shown in FIG. 4B, in the preparation step, a reference pipe P2 having the same outer diameter and inner diameter as the long pipe P1, which is a test pipe, is prepared. In order to make the X-ray transmittance equal, it is preferable to prepare a reference tube P2 made of the same material as the long tube P1. Then, a first ring member 7 having an outer diameter substantially the same as the inner diameter of the reference pipe P2 and having a wall thickness t7 (for example, 0.8 mm) according to the route determination standard is attached to the inner surface of the reference pipe P2 (fitting) Included).
In addition, a second ring member 8 having an inner diameter substantially the same as the outer diameter of the reference pipe P2 and having a wall thickness t8 (for example, 0.8 mm) according to the gap determination standard is attached to the outer surface of the reference pipe P2. Included).
Furthermore, a third ring member 9 having an inner diameter substantially the same as the outer diameter of the reference pipe P2 and having a thickness t9 (for example, 0.3 mm) according to the misalignment criterion is attached to the outer surface of the reference pipe P2 ( Fit). In the present embodiment, the third ring member 9 is formed integrally with the second ring member 8 in the axial direction. Specifically, for example, the amount of cutting of the outer surface of the cylindrical member, which is a material for forming the ring members 8 and 9, is integrated by changing according to the axial position of the cylindrical member. The ring members 8 and 9 can be formed. Since the third ring member 9 of the present embodiment is formed integrally with the second ring member 8, when the second ring member 8 is attached to the outer surface of the reference pipe P2, the third ring member 9 is also the reference at the same time. It will be attached to the outer surface of the pipe P2.

Next, in a state where the long tube P1 does not exist in the X-ray inspection apparatus 4, the reference tube P2 to which the first ring member 7, the second ring member 8, and the third ring member 9 are attached is installed in the X-ray inspection apparatus 4. To do. Then, a first reference image that is an X-ray image of the reference tube P2 including the first ring member 7 is generated using the X-ray inspection machine 41c at a position where X-rays are emitted to the first ring member 7. In the present embodiment, one first reference image is generated in a state where the X-ray source 412 and the X-ray image detector 413 are in positions facing each other in the vertical direction (a state indicated by a solid line in FIG. 2B). .
Further, after adjusting the position of the reference tube P2 in the longitudinal direction as necessary so that X-rays are emitted to the second ring member 8, the reference tube including the second ring member 8 using the X-ray inspection machine 41c is used. A second reference image that is an X-ray image of P2 is generated. Specifically, similarly to the first reference image, the second reference image is generated in a state where the X-ray source 412 and the X-ray image detector 413 are in positions facing each other in the vertical direction.
Furthermore, after adjusting the position of the reference tube P2 in the longitudinal direction as necessary so that X-rays are emitted to the third ring member 9, the reference tube including the third ring member 9 using the X-ray inspection machine 41c is used. A third reference image that is an X-ray image of P2 is generated. Specifically, similarly to the first reference image, the third reference image is generated in a state where the X-ray source 412 and the X-ray image detector 413 are in positions facing each other in the vertical direction.
The generated first reference image to third reference image are stored in the image processing device 414 of the X-ray inspection machine 41c.

<Inspection process>
In the inspection process, as described above, at the timing when the circumferential weld PW of the long pipe P1 arrives at the arrangement position of the X-ray inspection apparatus 4 (position where the X-ray source 412 emits X-rays), the X-ray inspection machine An inspection image which is an X-ray image of the long tube P1 including the circumferential weld PW is generated using 41c. Specifically, the X-ray source 412 and the X-ray image detector 413 are not only in positions facing each other in the vertical direction, but also in three positions at a 60 ° pitch shown in FIG. The inspection image is generated.

<Judgment process>
In the determination step, the quality of the circumferential weld PW of the long pipe P1 is determined using the first reference image to the third reference image stored in the image processing device 414 and the inspection image. Specifically, the quality of the route of the circumferential weld PW is determined by comparing the first reference image and the three inspection images. Further, the quality of the cap of the circumferential weld PW is determined by comparing the second reference image and the three inspection images. Furthermore, the quality of the alignment of the circumferential weld PW is determined using the third reference image and the three inspection images. In this embodiment, when comparing each reference image and the inspection image, pixel regions corresponding to the vicinity of both side edges in the radial direction of the reference tube P2 in each reference image are extracted, and the long tube in the inspection image is extracted. Pixel regions corresponding to the vicinity of both side edges in the radial direction of P1 are extracted, and pixel regions on the same side are compared with each other. The “radial both-side edges” of the reference tube P2 or the long tube P1 means that the reference tube P2 or the long tube P1 is projected onto a plane orthogonal to the facing direction of the X-ray source 412 and the X-ray image detector 413. In this case, one edge (outer surface edge and inner surface edge) in the radial direction with respect to the central axis of the reference tube P2 or the long tube P1 and the other radial direction with respect to the central axis of the reference tube P2 or the long tube P1 Means side edges (outer and inner edges).
In the present embodiment, only one each of the first reference image to the third reference image is generated. However, the present invention is not limited to this, and the 60 ° shown in FIG. It is also possible to generate a total of three first to third reference images, respectively, at three positions on the pitch. In this case, the comparison between the first reference image and the inspection image may be performed by comparing images generated in a state where the X-ray source 412 and the X-ray image detector 413 are at the same position. The same applies to the second reference image and the third reference image.
Hereinafter, the determination method for each determination target will be described more specifically.

<Routine pass / fail judgment>
FIG. 5 is an explanatory diagram for explaining a method of determining the quality of the route of the circumferential weld PW. FIG. 5 shows an example in which it is determined that the route of the circumferential weld PW is defective. FIG. 5A is a diagram schematically illustrating an example of a first reference image (specifically, a pixel region corresponding to the vicinity of one edge in the radial direction of the reference tube P2 in the first reference image). FIG. 6B is a diagram schematically illustrating a density profile along the Y direction at a predetermined position in the X direction of the first reference image. FIG. 5C is a diagram schematically showing an example of one inspection image (specifically, a pixel region corresponding to the vicinity of one edge in the radial direction of the long tube P1 in the inspection image). (D) is a figure which shows typically the density profile along the Y direction in the predetermined | prescribed X direction position of a test | inspection image. The X direction shown in FIG. 5 indicates a direction corresponding to the longitudinal direction of the long pipe P1 and the reference pipe P2. The Y direction indicates a direction corresponding to the radial direction of the long pipe P1 and the reference pipe P2. The same applies to the X direction and the Y direction shown in FIGS.
As shown in FIG. 5, when determining the quality of the route, the image processing device 414 of the X-ray inspection machine 41c uses a pixel region PI corresponding to the inner surface of the long tube P1 in the inspection image (FIG. 5C). And the radial direction position (Y direction position) of the pixel region PI corresponding to the inner surface of the reference tube P2 in the first reference image (FIG. 5A), The inspection image and the first reference image are compared. Specifically, the image processing apparatus 414 according to the present embodiment displays both images Y so that the Y-direction position of the pixel area PI in the inspection image matches the Y-direction position of the pixel area PI in the first reference image. After parallel translation in the direction, both images are simultaneously displayed on a monitor provided in the image processing device 414. In the example shown in FIG. 5, for convenience, one first reference image and one inspection image are displayed at the same time, but actually, in the present embodiment, one first image is provided for each of both sides in the radial direction. A reference image and three inspection images are displayed simultaneously.

The position in the Y direction of the pixel region PI in the first reference image (FIG. 5A) is, for example, the density along the Y direction at a predetermined X direction position of the first reference image shown in FIG. 5B. It can be automatically detected by detecting the minimum point of the profile. In the first reference image, the position in the X direction of the pixel area corresponding to the first ring member 7 can be grasped in advance. For this reason, the predetermined X-direction position for evaluating the density profile may be set to the position of the pixel region corresponding to the portion of the reference tube P2 to which the first ring member 7 is not attached in the first reference image. .
Similarly, the Y direction position of the pixel region PI in the inspection image (FIG. 5C) is, for example, the minimum of the density profile along the Y direction at the predetermined X direction position of the inspection image shown in FIG. It can be automatically detected by detecting a point. In the inspection image, the position in the X direction of the pixel region corresponding to the circumferential weld PW can be predicted in advance. This is because, as described above, the long pipe P1 is stopped at the timing when the circumferential welding portion PW arrives at the position where the X-ray source 412 emits X-rays by the control device 5. For this reason, the predetermined X-direction position for evaluating the density profile may be set to the position of the pixel region corresponding to the portion of the long pipe P1 where the circumferential weld PW is not formed in the inspection image.

The radial position (Y-direction position) of the pixel region BI corresponding to the top of the inner surface bead of the circumferential weld PW in the inspection image (FIG. 5C) is the first reference image (FIG. 5A). If the radial position (Y direction position) of the pixel region 71 corresponding to the inner surface of the first ring member 7 in the middle is the same as or outside the radial direction (Y direction), the peripheral weld PW has a good inner bead size. It is possible to determine that there is a route (the route is equal to or less than the criterion).
The image processing device 414 may automatically determine whether or not the Y direction position of the pixel area BI in the inspection image is the same as the Y direction position of the pixel area 71 in the first reference image or outside the Y direction. As shown in FIG. 5, a straight line 72 passing through the pixel region 71 and orthogonal to the Y direction may be displayed on the monitor, and the operator may make a visual decision.

The position in the Y direction of the pixel region 71 in the first reference image (FIG. 5A) is, for example, a density along the Y direction at a predetermined X direction position of the first reference image shown in FIG. 5B. It can be automatically detected by detecting the minimum point of the profile. The predetermined X-direction position may be set to a position of a pixel region corresponding to the first ring member 7 that can be grasped in advance in the first reference image.
Similarly, the position in the Y direction of the pixel region BI in the inspection image (FIG. 5C) is, for example, the minimum of the density profile along the Y direction at the predetermined X direction position of the inspection image shown in FIG. It can be automatically detected by detecting a point. The predetermined X-direction position may be set to a position of a pixel region corresponding to the circumferential weld PW that can be predicted in advance in the inspection image.

On the other hand, the radial position (Y-direction position) of the pixel region BI corresponding to the top of the inner surface bead of the circumferential weld PW in the inspection image (FIG. 5C) is the first reference image (FIG. 5A). If the inner diameter of the inner circumferential bead PW is in the radial direction (Y direction) than the radial position (Y direction position) of the pixel region 71 corresponding to the inner surface of the first ring member 7 in the middle, the dimension of the inner surface bead is poor. It is possible to determine that the route exceeds the criterion.
In the example shown in FIG. 5, since the radial position of the pixel region BI is radially inward of the radial position of the pixel region 71, it is determined that the dimension of the inner surface bead of the circumferential weld PW is poor.
According to the route quality determination method described above, since it is possible to determine relatively easily only by comparing the first reference image and the inspection image, in the manufacturing process of the long pipe P1, the circumferential weld PW It is possible to determine the total quality of the dimensions of the inner surface bead.

<Decision determination of cap>
FIG. 6 is an explanatory diagram for explaining a method for determining the quality of the cap of the circumferential weld PW. FIG. 6 shows an example in which it is determined that the cap of the circumferential weld PW is defective. FIG. 6A is a diagram schematically showing an example of the second reference image (specifically, a pixel region corresponding to the vicinity of one edge in the radial direction of the reference tube P2 in the second reference image). (B) is a diagram schematically showing a density profile along the Y direction at a predetermined position in the X direction of the second reference image. FIG. 6C is a diagram schematically showing an example of one inspection image (specifically, a pixel region corresponding to the vicinity of one edge in the radial direction of the long tube P1 in the inspection image). (D) is a figure which shows typically the density profile along the Y direction in the predetermined | prescribed X direction position of a test | inspection image.
As shown in FIG. 6, when determining the quality of the cap, the image processing device 414 of the X-ray inspection machine 41c uses a pixel region PO corresponding to the outer surface of the long tube P1 in the inspection image (FIG. 6C). And the radial position (Y direction position) of the pixel region PO corresponding to the outer surface of the reference tube P2 in the second reference image (FIG. 6A), The inspection image and the second reference image are compared. Specifically, the image processing apparatus 414 according to the present embodiment displays both images Y so that the Y-direction position of the pixel area PO in the inspection image matches the Y-direction position of the pixel area PO in the second reference image. After parallel translation in the direction, both images are simultaneously displayed on a monitor provided in the image processing device 414. In the example shown in FIG. 6, for convenience, one second reference image and one inspection image are displayed at the same time, but actually, in the present embodiment, one second reference image is provided for each of both sides in the radial direction. A reference image and three inspection images are displayed simultaneously.

The position in the Y direction of the pixel region PO in the second reference image (FIG. 6A) is, for example, the density along the Y direction at the predetermined X direction position of the second reference image shown in FIG. 6B. It can be automatically detected by detecting the maximum point of the profile. Further, in the second reference image, the position in the X direction of the pixel region corresponding to the second ring member 8 can be grasped in advance. For this reason, the predetermined X-direction position for evaluating the density profile may be set to the position of the pixel region corresponding to the portion of the reference tube P2 to which the second ring member 8 is not attached in the second reference image. .
Similarly, the position in the Y direction of the pixel region PO in the inspection image (FIG. 6C) is, for example, the maximum of the density profile along the Y direction at a predetermined X direction position of the inspection image shown in FIG. It can be automatically detected by detecting a point. Further, as the predetermined X-direction position for evaluating the density profile, as in the case of determining the quality of the route, in the inspection image, a pixel corresponding to a portion of the long pipe P1 where the circumferential weld PW is not formed. What is necessary is just to set to the position of an area | region.

Then, the radial position (Y-direction position) of the pixel region BO corresponding to the top of the outer surface bead of the circumferential weld PW in the inspection image (FIG. 6C) is the second reference image (FIG. 6A). If the radial position (Y direction position) of the pixel region 81 corresponding to the outer surface of the second ring member 8 in the middle is the same as or radially inward (Y direction), the peripheral weld PW has a good outer bead size. It is possible to determine that the cap is present (the cap is equal to or less than the criterion).
The image processing apparatus 414 may automatically determine whether the Y direction position of the pixel area BO in the inspection image is the same as or inward of the Y direction position of the pixel area 81 in the second reference image. As shown in FIG. 6, a straight line 82 that passes through the pixel region 81 and is orthogonal to the Y direction may be displayed on the monitor, and the operator may make a visual decision.

The position in the Y direction of the pixel region 81 in the second reference image (FIG. 6A) is, for example, the density along the Y direction at a predetermined X direction position of the second reference image shown in FIG. 6B. It can be automatically detected by detecting the maximum point of the profile. The predetermined X-direction position may be set to a position of a pixel region corresponding to the second ring member 8 that can be grasped in advance in the second reference image.
Similarly, the position in the Y direction of the pixel region BO in the inspection image (FIG. 6C) is, for example, the maximum of the density profile along the Y direction at a predetermined X direction position of the inspection image shown in FIG. It can be automatically detected by detecting a point. The predetermined X-direction position may be set to a position of a pixel region corresponding to the circumferential weld PW that can be predicted in advance in the inspection image.

On the other hand, the radial position (Y-direction position) of the pixel region BO corresponding to the top of the outer surface bead of the circumferential weld PW in the inspection image (FIG. 5C) is the second reference image (FIG. 6A). If the outer diameter of the outer peripheral bead PW is outside the radial direction (Y direction position) of the pixel region 81 corresponding to the outer surface of the second ring member 8 in the radial direction (Y direction position), the dimension of the outer surface bead is poor. It is possible to determine that the cap exceeds the criterion.
In the example shown in FIG. 6, since the radial position of the pixel region BO is outside the radial direction of the pixel region 81, it is determined that the dimension of the outer surface bead of the circumferential weld PW is defective.
According to the cap quality determination method described above, since it is possible to determine relatively easily by simply comparing the second reference image and the inspection image, in the manufacturing process of the long pipe P1, the circumferential weld PW It is possible to determine the quality of the dimensions of the outer bead.

<Alignment pass / fail judgment>
FIG. 7 is an explanatory diagram for explaining a method for determining the quality of the alignment of the circumferential weld PW. FIG. 7 shows an example in which it is determined that the alignment of the circumferential weld PW is good. FIG. 7A is a diagram schematically illustrating an example of a third reference image (specifically, a pixel region corresponding to the vicinity of one edge in the radial direction of the reference tube P2 in the third reference image). FIG. 6B is a diagram schematically illustrating a density profile along the Y direction at a predetermined position in the X direction of the third reference image. FIG. 7C is a diagram schematically showing an example of one inspection image (specifically, a pixel region corresponding to the vicinity of one side edge in the radial direction of the long tube P1 in the inspection image). (D) is a figure which shows typically the density profile along the Y direction in the predetermined | prescribed X direction position of a test | inspection image.
As shown in FIG. 7, when determining the quality of the alignment, the image processing device 414 of the X-ray inspection machine 41c sandwiches the circumferential weld PW of the long tube P1 in the inspection image (FIG. 7C). The radial position of the pixel region PO corresponding to one of the outer surfaces located on the inner side in the radial direction (Y direction) (the outer surface located above the circumferential weld PW in the example shown in FIG. 7C). (Y-direction position) and the radial position (Y-direction position) of the pixel region PO corresponding to the outer surface of the reference tube P2 in the third reference image (FIG. 7A) are matched, Compare the three reference images. Specifically, the image processing apparatus 414 according to the present embodiment displays both images Y so that the Y-direction position of the pixel area PO in the inspection image matches the Y-direction position of the pixel area PO in the third reference image. After parallel translation in the direction, both images are simultaneously displayed on a monitor provided in the image processing device 414. In the example shown in FIG. 7, for convenience, one third reference image and one inspection image are displayed at the same time. Actually, in the present embodiment, one third reference image is provided on each of both sides in the radial direction. A reference image and three inspection images are displayed simultaneously.

The position in the Y direction of the pixel region PO in the third reference image (FIG. 7A) is, for example, the density along the Y direction at the predetermined X direction position of the third reference image shown in FIG. 7B. It can be automatically detected by detecting the maximum point of the profile. Further, in the third reference image, the X-direction position of the pixel region corresponding to the third ring member 9 can be grasped in advance. For this reason, the predetermined X-direction position for evaluating the density profile may be set to the position of the pixel region corresponding to the portion of the reference tube P2 to which the third ring member 9 is not attached in the third reference image. .
Similarly, the position in the Y direction of the pixel region PO in the inspection image (FIG. 7C) is, for example, the maximum of the density profile along the Y direction at a predetermined X direction position of the inspection image shown in FIG. It can be automatically detected by detecting a point. In addition, the predetermined X-direction position for evaluating the concentration profile corresponds to a portion of the long pipe P1 in which the circumferential weld PW is not formed in the inspection image, as in the case of determining the quality of the route and the cap. What is necessary is just to set to the position of the pixel area | region to perform.
In the inspection image, it can be determined as follows which of the two outer surfaces sandwiching the circumferential weld PW of the long pipe P1 is located on the inner side in the Y direction. That is, in the same manner as detecting the Y-direction position of the pixel region PO from the maximum point of the density profile at the X-direction position located above the circumferential weld PW, the density at the X-direction position located below the circumferential weld PW. The position in the Y direction of the pixel region PO ′ is detected from the maximum point of the profile. Then, it may be determined which of the Y direction position of the pixel area PO and the Y direction position of the pixel area PO ′ is inside the Y direction. In the example shown in FIG. 7, the Y direction position of the pixel region PO is inward in the Y direction.

Then, the pixel region PO ′ corresponding to the other outer surface located on the outer side in the radial direction (Y direction) among the two outer surfaces sandwiching the circumferential weld PW of the long pipe P1 in the inspection image (FIG. 7C). The radial position is the same as the radial position (Y-direction position) of the pixel region 91 corresponding to the outer surface of the third ring member 9 in the third reference image (FIG. 7A) or inside the radial direction (Y-direction). If this is the case, it is possible to determine that the circumferential weld PW has good alignment (misalignment is equal to or less than the criterion).
The image processing device 414 may automatically determine whether the Y direction position of the pixel area PO ′ in the inspection image is the same as or inward of the Y direction position of the pixel area 91 in the third reference image. Then, as shown in FIG. 7, a straight line 92 passing through the pixel region 91 and orthogonal to the Y direction may be displayed on the monitor, and the operator may make a visual decision.
In the example shown in FIG. 7, since the radial position of the pixel region PO ′ is radially inward of the radial direction position of the pixel region 91, it is determined that the alignment of the circumferential weld PW is good.

  The position in the Y direction of the pixel region 91 in the third reference image (FIG. 7A) is, for example, the density along the Y direction at a predetermined X direction position of the third reference image shown in FIG. 7B. It can be automatically detected by detecting the maximum point of the profile. The predetermined X-direction position may be set to a position of a pixel region corresponding to the third ring member 9 that can be grasped in advance in the third reference image.

On the other hand, the pixel region PO ′ corresponding to the other outer surface located on the outer side in the radial direction (Y direction) among both outer surfaces sandwiching the circumferential weld PW of the long pipe P1 in the inspection image (FIG. 7C). The radial position is on the outer side in the radial direction (Y direction) than the radial position (Y direction position) of the pixel region 91 corresponding to the outer surface of the third ring member 9 in the third reference image (FIG. 7A). If there is, it is possible to determine that the circumferential weld PW is poorly aligned (misalignment exceeds the criterion).
According to the alignment quality determination method described above, since it can be determined relatively easily by simply comparing the third reference image and the inspection image, in the manufacturing process of the long pipe P1, the circumferential weld PW It is possible to determine the total quality of alignment.

  When it is determined that the peripheral weld PW of the long pipe P1 is defective by the inspection method of the peripheral weld PW according to the present embodiment described above, as described above, the welding device 2 and the X-ray inspection device 4 are used. Can be moved separately from each other along the transfer device 1, the control device 5 can execute the following first to sixth procedures as a preferred mode. Hereinafter, the first to sixth procedures executed by the control device 5 will be described with reference to FIGS. 8 to 13 as appropriate. 8 to 14 are plan views for explaining the movements of the welding apparatus 2 and the X-ray inspection apparatus 4 according to the first to sixth procedures executed by the control device, and the illustration of the conveying device 1 is omitted for convenience. doing.

<First procedure>
When it is determined by the X-ray inspection apparatus 4 at the initial position indicated by the broken line in FIG. 8 that the circumferential weld PW of the long pipe P1 is defective, the control device 5 causes the X-ray inspection apparatus 4 to be connected to the long pipe P1. Is moved downstream in the transport direction. The amount of movement of the X-ray inspection apparatus 4 does not interfere with the cutting operation of the peripheral weld PW determined to be defective, and the welding apparatus 2 is moved in the conveying direction of the long pipe P1 in the second procedure described later. It is preferable to set so that the welding apparatus 2 does not interfere with the X-ray inspection apparatus 4 when moved to the downstream side.
After the X-ray inspection apparatus 4 moves, as shown in FIG. 9, the circumferential weld PW determined to be defective may be cut. The cutting of the circumferential weld PW can be performed manually by an operator using, for example, a portable cutting machine installed on the downstream side of the welding device 2.
In addition, it is preferable that the end surface of the long pipe P1 after cutting is subjected to deburring, polishing, and the like so that circumferential welding can be easily performed in a third procedure described later. Deburring and polishing of the end face of the long pipe P1 can be performed manually by an operator using, for example, a portable groove / chamfering machine installed on the downstream side of the welding apparatus 2.

<Second procedure>
Next, as shown in FIG. 10, the control device 5 is a welding device in an initial position indicated by a broken line up to the cutting position of the long pipe P <b> 1 after the circumferential weld PW determined to be defective is cut. 2 is moved downstream in the conveying direction of the long pipe P1.

<Third procedure>
Next, as shown in FIG. 11, the control device 5 drives the welding device 2 and again performs circumferential welding on the cut portion of the long pipe P <b> 1 by the welding device 2, thereby forming the circumferential welded portion PW.
According to the first to third procedures described above, it is necessary to transport the long pipe P1 in the reverse direction (upstream side) by driving the transport device 1 and the winding device 3 (see FIG. 1) in the reverse direction. There is no. Instead of transporting the long tube P1 in the reverse direction, the X-ray inspection device 4 and the welding device 2 are moved in the normal transport direction of the long tube P1.

<4th procedure>
Next, as shown in FIG. 12, the control device 5 moves the welding device 2 to the upstream side in the transport direction of the long pipe P1. At this time, it is preferable to move the welding apparatus 2 to the initial position (position shown in FIG. 8). Thereby, even if the X-ray inspection apparatus 4 is moved in the fifth procedure described later, the welding apparatus 2 does not interfere with the X-ray inspection apparatus 4.

<5th procedure>
Next, as shown in FIG. 13, the control device 5 moves the X-ray inspection device 4 to the upstream side in the transport direction of the long tube P <b> 1 until the circumferential weld PW of the long tube P <b> 1 is formed again. That is, the X-ray inspection apparatus 4 is moved to the initial position (position indicated by a broken line in FIG. 8).
Note that the fourth procedure and the fifth procedure may be executed simultaneously as long as the moving speed of the X-ray inspection apparatus 4 is higher and there is no problem that the welding apparatus 2 and the X-ray inspection apparatus 4 interfere with each other. Is possible.

<Sixth procedure>
Finally, the control device 5 drives the X-ray inspection device 4 and inspects the circumferential weld PW formed again by the X-ray inspection device 4 on the long tube P1.
Even in the fourth to sixth procedures described above, there is no need to transport the long pipe P1.
That is, by performing the above first to sixth procedures, the welding apparatus is not driven in the reverse direction (without transporting the long pipe P1 in the reverse direction), and the welding apparatus. 2, the circumferential weld PW can be formed again on the long pipe P <b> 1, and the circumferential weld PW formed again by the X-ray inspection apparatus 4 can be inspected. For this reason, generation | occurrence | production of the outer surface defect resulting from conveying the elongate pipe P1 to a reverse direction, and deterioration of intensity | strength can be suppressed.

  As a result of executing the above first to sixth procedures, when it is determined that the circumferential weld PW formed again is normal, the control device 5 drives the conveying device 2 and the winding device 3, The long tube P <b> 1 is transported and wound around the reel 31. On the other hand, when it is determined that the circumferential weld PW formed again is defective, the first to sixth procedures are repeatedly executed.

DESCRIPTION OF SYMBOLS 1 ... Conveying device 2 ... Welding device 3 ... Winding device 4 ... X-ray inspection device 5 ... Control device 7 ... 1st ring member 8 ... 2nd ring member 9 ... Third ring member 31 ... Reel 41 ... X-ray inspection apparatus main body 42 ... X-ray leakage suppression mechanism 100 ... Long pipe manufacturing equipment P ... Pipe P1 ... covered Inspection tube (long tube)
P2 ... reference pipe PW ... circumferential weld

Claims (3)

An X-ray source that emits X-rays toward the tube to be inspected, and a position that faces the X-ray source across the tube to be inspected, is emitted from the X-ray source and passes through the tube to be inspected A method for inspecting a peripheral weld of a tube to be inspected using an X-ray inspection machine comprising an X-ray image detector that detects an X-ray and generates an X-ray image,
A reference pipe having the same outer diameter and inner diameter as the pipe to be inspected is prepared, and a first ring member having an outer diameter substantially the same as the inner diameter of the reference pipe and having a thickness corresponding to the determination standard is provided on the inner face of the reference pipe. Mounting, preparing a first reference image that is an X-ray image of the reference tube including the first ring member using the X-ray inspection machine;
An inspection step of generating an inspection image which is an X-ray image of the inspection tube including the circumferential weld using the X-ray inspection machine;
Using the first reference image and the inspection image, and a determination step of determining the quality of the peripheral weld of the tube to be inspected,
In the determination step,
The radial position of the pixel region corresponding to the inner surface of the inspection tube in the inspection image is matched with the radial position of the pixel region corresponding to the inner surface of the reference tube in the first reference image, When comparing the inspection image and the first reference image,
The radial position of the pixel region corresponding to the top of the inner surface bead of the circumferential weld in the inspection image is the same as the radial position of the pixel region corresponding to the inner surface of the first ring member in the first reference image. Or, if the outer side in the radial direction, the circumferential weld is determined to have good internal bead dimensions,
The radial position of the pixel region corresponding to the top of the inner surface bead of the circumferential weld in the inspection image is greater than the radial position of the pixel region corresponding to the inner surface of the first ring member in the first reference image. If it is radially inward, the circumferential weld will determine that the inner bead dimension is poor,
A method for inspecting a circumferential welded portion. In the preparation step, a second ring member having an inner diameter substantially the same as the outer diameter of the reference tube and having a thickness corresponding to a determination criterion is attached to the outer surface of the reference tube, and the X-ray inspection machine is used to Generating a second reference image that is an X-ray image of the reference tube including a second ring member;
In the determination step,
The radial position of the pixel region corresponding to the outer surface of the inspection tube in the inspection image is matched with the radial position of the pixel region corresponding to the outer surface of the reference tube in the second reference image, When comparing the inspection image and the second reference image,
The radial position of the pixel region corresponding to the top of the outer surface bead of the circumferential weld in the inspection image is the same as the radial position of the pixel region corresponding to the outer surface of the second ring member in the second reference image. Or, if the inner side in the radial direction, the circumferential weld is determined to have good outer bead dimensions,
The radial position of the pixel region corresponding to the top of the outer surface bead of the circumferential weld in the inspection image is greater than the radial position of the pixel region corresponding to the outer surface of the second ring member in the second reference image. If the outer side in the radial direction, the circumferential weld is determined to have a defective outer bead size,
The method for inspecting a circumferential weld according to claim 1. In the preparation step, a third ring member having an inner diameter substantially the same as the outer diameter of the reference tube and having a thickness corresponding to a determination criterion is attached to the outer surface of the reference tube, and the X-ray inspection machine is used to Generating a third reference image that is an X-ray image of the reference tube including a third ring member;
In the determination step,
A radial position of a pixel region corresponding to one outer surface located on the radially inner side of both outer surfaces sandwiching a circumferential welded portion of the tube to be inspected in the inspection image, and the reference tube in the third reference image When the inspection image and the third reference image are compared by matching the radial direction position of the pixel region corresponding to the outer surface of
The radial position of the pixel region corresponding to the other outer surface located on the outer side in the radial direction among the two outer surfaces sandwiching the circumferential welded portion of the tube to be inspected in the inspection image is the third position in the third reference image. If it is the same as the radial position of the pixel region corresponding to the outer surface of the ring member or the radially inner side, the circumferential weld is determined to have good alignment,
The radial position of the pixel region corresponding to the other outer surface of the inspection tube in the inspection image is larger than the radial position of the pixel region corresponding to the outer surface of the third ring member in the third reference image. If it is radially outside, the circumferential weld is determined to have poor alignment.
The method for inspecting a circumferential weld according to claim 1 or 2, wherein