JP2952187B2 - ERW pipe inspection apparatus, ERW pipe manufacturing apparatus and manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus for detecting welding defects in an ERW pipe with high sensitivity, an ERW pipe manufacturing apparatus, and a manufacturing method.

[0002]

2. Description of the Related Art An electric resistance welded pipe is a general term for a metal pipe manufactured by rolling a metal plate strip continuously through a plurality of forming rolls and then welding the butted edges. , Compared to seamless (seamless) pipes obtained by extrusion or drawing
There is an advantage in the manufacturing method that various processing can be performed at the stage of the strip material.

[0003] Incidentally, since an electric resistance welded tube necessarily has a welded portion continuous in the tube axis direction, it is extremely important to enhance the reliability of the welded portion. Therefore, conventionally, an inspection method of judging the presence or absence of a welding defect by passing the welded ERW pipe through an eddy current flaw detector as it is and detecting an abnormal eddy current due to a welding defect has been adopted.

[0004]

However, with the conventional inspection method, it has been difficult to reliably detect a seemingly normal defective portion. At first glance, a normally welded defect is a part of the weld in the thickness direction of the pipe wall that is not completely welded, and the interface is temporarily joined, resulting in abnormal eddy currents. It is difficult to detect with an eddy current flaw detector. In addition, since airtightness is ensured, it cannot be detected by a leak test using helium gas or the like. However, it is inferior to the normal part in terms of welding strength, and must be eliminated from the product as much as possible.

FIG. 11 is a sectional view showing an inner grooved heat transfer tube 1 as a kind of the electric resistance welded tube. The heat transfer tube 1 has a circular cross section, and a plurality of parallel fins 2 are formed spirally at a constant angle with respect to the tube axis over substantially the entire inner surface of the heat transfer tube 1. It is 3. Further, a welded portion 4 formed by electric resistance welding is formed at one location on the inner peripheral surface of the heat transfer tube 1, and finless portions 5 extending parallel to the central axis of the heat transfer tube 1 are formed on both sides of the welded portion 4. Each fin 2 is divided by the finless portion 5.

When the fins 2 and the spiral grooves 3 are formed on the inner surface of the electric resistance welded tube as described above, the fins 2 and the spiral grooves 3 are erroneously determined to be defective by increasing the flaw detection sensitivity of the eddy current flaw detector. Therefore, there is a limit in improving the flaw detection sensitivity. Therefore,
In the manufacturing process of this type of heat transfer tube with an inner groove, there is a special feature that it is more difficult to detect a seemingly normal defective portion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an electric resistance welded tube inspection device and an electric resistance welded tube manufacturing device capable of detecting even a seemingly normally welded defective portion of an electric resistance welded tube. And to provide a manufacturing method.

[0008]

In order to achieve the above object, a first ERW pipe inspection apparatus according to the present invention comprises an ERW pipe transport mechanism for moving an ERW pipe in a longitudinal direction thereof, and a traveling mechanism. An elliptical mechanism for revealing potential welding defects in the ERW pipe by deforming the ERW pipe into an elliptical cross section, and a circle for returning the ERW pipe with an elliptical cross section to a circular cross section And a flaw detection mechanism for detecting the revealed defect of the ERW tube having a circular cross section, wherein the elliptical mechanism sandwiches the ERW tube between outer peripheral surfaces of the ERW tube. A pair of elliptical rolls that rotate while being compressed, and a roll support mechanism that supports the elliptical rolls so that these elliptical rolls can rotate around the pipe axis of the ERW pipe. The outer peripheral surface is characterized in that it has an arc-shaped cross section.

A second ERW pipe inspection apparatus according to the present invention comprises an ERW pipe transport mechanism for moving the ERW pipe in its longitudinal direction, and deforming the running ERW pipe into an elliptical cross section. Thus, an elliptical mechanism for revealing a welding defect latent in the ERW pipe, a flaw detection mechanism for detecting the revealed defect of the ERW pipe having an elliptical cross section, and an elliptical cross section A circularization mechanism for returning the formed ERW pipe to a circular cross section, wherein the elliptical mechanism is a pair of elliptical rolls that rotate while compressing the ERW pipe between its outer peripheral surfaces. And a roll support mechanism that supports the elliptical roll so that these elliptical rolls can rotate around the pipe axis of the electric resistance welded pipe. The outer peripheral surface of the elliptical roll has an arc-shaped cross section. It is characterized by.

On the other hand, a first apparatus for manufacturing an electric resistance welded pipe according to the present invention comprises a tube forming mechanism for forming a metal strip into a tubular shape while running the metal strip through a plurality of forming rolls. A welding mechanism for heating and butt-welding both end edges of the tubular strip material to make an ERW pipe,
By deforming the running ERW pipe into an elliptical cross section,
An elliptical mechanism for revealing welding defects latent in the ERW pipe, a circularization mechanism for returning an ERW pipe having an elliptical cross section to a circular cross section, and an ERW pipe having a circular cross section And a flaw detection mechanism for detecting the revealed defects of the
The elliptical mechanism includes a pair of elliptical rolls that rotate while compressing the ERW tube between the outer peripheral surfaces thereof, and the elliptical roll so that these elliptical rolls can rotate around the pipe axis of the ERW tube. A roll support mechanism for supporting the forming roll, wherein an outer peripheral surface of the elliptical roll has an arc-shaped cross section.

A second apparatus for manufacturing an electric resistance welded pipe according to the present invention comprises: a tube forming mechanism for forming a metal strip into a tube while passing the metal strip through a plurality of forming rolls; A welding mechanism for heating and butt-welding both end edges of the tubular strip material to make an ERW pipe,
By deforming the running ERW pipe into an elliptical cross section,
An elliptical mechanism for revealing a welding defect latent in the ERW pipe, a flaw detection mechanism for detecting the revealed defect of the ERW pipe having an elliptical cross section, and an elliptical cross section. A circularization mechanism for returning the ERW tube to a circular cross section,
The elliptical mechanism includes a pair of elliptical rolls that rotate while compressing the ERW tube between the outer peripheral surfaces thereof, and the elliptical roll so that these elliptical rolls can rotate around the pipe axis of the ERW tube. A roll support mechanism for supporting the forming roll, wherein an outer peripheral surface of the elliptical roll has an arc-shaped cross section.

[0012]

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of an inspection apparatus for an electric resistance welded pipe, an apparatus for producing an electric resistance welded pipe, and a production method according to the present invention will be described in detail with reference to the drawings. In addition, these embodiments are for manufacturing an inner grooved heat transfer tube by forming a groove on the surface of a plate material and performing an electric resistance welding process, but the present invention relates to such an inner surface. The present invention is not limited to the application to the grooved heat transfer tube, but can be applied to the inspection and manufacture of an ERW pipe having a smooth inner surface or an ERW pipe having a groove or fin formed on the outer surface.

[First Embodiment] FIGS. 1 and 2 are side views showing a first embodiment of an electric resistance welded tube inspection apparatus and a manufacturing apparatus according to the present invention. FIG. Indicates the latter stage of the apparatus, respectively. First, an outline of the apparatus will be described. In the drawing, reference numeral 10 denotes an uncoiler (electrically-welded tube transport mechanism) for continuously feeding a metal plate strip T having a constant width, and the fed plate strip T is a pair of holding rolls. 12, through the opposed grooved roll 14 and the smoothing roll 16,
The fin 2 and the spiral groove 3 as illustrated in FIG. 11 are formed by the grooved roll 14.

The grooved plate strip T is made up of a pair of rolls 1
8 and gradually rounded into a tubular form through a plurality of paired forming rolls (tube forming mechanism) 20, a rolling separator 21 keeps a constant gap between both end edges to be abutted, and an induction heating coil. (Welding mechanism) is passed through 22 to heat both side edges. The plate material T formed into a tubular shape and heated is passed through a pair of squeeze rolls 24, and is pressed from both sides so that the heated side edges are butted and welded. Since a bead is formed by the protruding molten material on the outer peripheral surface of the ERW pipe P thus welded, the bead is cut by the bead cutter 26.

The ERW pipe P from which the beads have been cut is placed in a cooling bath 28.
, And is forcibly cooled, passed through an elliptical roll (elliptical mechanism) 30 which is a main feature of the present invention, and deformed from a circular cross section to an elliptical cross section. The electric resistance welded pipe P once made into an elliptical cross section is passed through a plurality of pairs of sizing rolls (rounding mechanisms) 32, and is again modified into a circular cross section and simultaneously reduced in diameter to a predetermined outer diameter. , And roughly wound by the rough coiler 33.

Next, the ERW pipe P roughly wound into a coil shape is transferred to an uncoiler 34 shown in FIG. 2, from which the ERW pipe P is fed out at a constant speed. ERW pipe P extended
Is passed through a roll 36 and a straightener 38 to correct the bending, and then passed through an eddy current flaw detector (flaw detection mechanism) 40 to perform eddy current flaw detection. The electric resistance welded pipe P that has passed through the eddy current detector 40 passes between the rolls 44 through the support rolls 42, passes through a position facing the ink spraying mechanism (mark mechanism) 43, and is densely wound by the alignment winding device 46. It is a coiled product.

On the other hand, the output of the eddy current flaw detector 40 is controlled by the control mechanism 4.
1 and the control mechanism 41 determines the presence or absence of a defect by signal processing. If the control mechanism 41 determines that there is a defect, the control mechanism 41
Activate When receiving the operation signal from the control mechanism 41, the ink spraying mechanism 43 continuously sprays quick-drying ink on the outer peripheral surface of the electric resistance welded pipe P during the duration of the operation signal. The defective part of P is marked. Further, a cover 45 is provided to prevent the ink from the ink spraying mechanism 43 from scattering around.

FIGS. 3 and 4 show the structure of the elliptical roll 30 which is a feature of this embodiment. The elliptical rolls 30 are arranged in a pair with the electric resistance welded pipe P interposed therebetween, and their axes are parallel to each other. Each of the elliptical rolls 30 is rotatably supported by a support frame 52 via a support shaft 50, and the support position of the support shaft 50 by the support frame 52 can be changed by loosening the fastener 54. .

On the outer peripheral surface of the elliptical roll 30, grooves 30A having a concave elliptical arc cross section along the roll axis are formed over the entire circumference, and the ERW pipe P is sandwiched between these grooves 30A.
Is deformed into an elliptical cross section. The orientation of the elliptical roll 30 may be such that the major axis of the cross section of the ERW pipe P elliptical by the elliptical roll 30 passes through the weld 4 or its vicinity, or the minor axis passes through the weld 4 or its vicinity. Is preferred. That is, as shown in the figure, it is preferable that the welded portion 4 is directed to the gap between the elliptical rolls 30 or to the center position of the groove 30A of one of the elliptical rolls 30.

As shown in FIG. 3, the major axis of the ellipse is
Or if it is set to pass near it,
As shown in FIG. 5 (b), the radius of curvature of the portion including the welded portion 4 is reduced, and as shown in FIG. 6 (b), the potential defect K1 on the outer peripheral surface of the electric resistance welded pipe P is pushed out to crack K2. Is highly effective.

On the other hand, when the minor axis of the ellipse is set so as to pass through or near the welded portion 4, the radius of curvature of the portion including the welded portion 4 is enlarged, and the potential radius on the inner peripheral surface of the ERW pipe P is increased. This has a high effect of spreading cracks that occur to generate cracks (see FIGS. 7C and 8C). However, in the present invention, it is not always necessary to exactly match the welded part 4 with the major axis or minor axis. The cross-sectional shape of the groove 30A does not have to be symmetrical with respect to the center of the groove. Is also good.

As shown in FIG. 3, the major axis D1 and the minor axis D2 of the ERW pipe P made elliptical by the elliptical roll 30.
Is preferably set to D1: D2 = 1.3: 1 to 1.9: 1, and more preferably 1.5: 1, regardless of the position of the welded portion 4 in the above position. ~ 1.
8: 1. If the ratio is less than 1.3: 1, the effect of eliciting defects due to ellipticity is poor. If the ratio is greater than 1.9: 1, the number of steps for returning the ERW pipe P to a circular cross section again increases.
However, since the effects of the present invention can be obtained even outside the above range, the present invention is not limited to the above range.

In the production of an electric resistance welded pipe, unexpected twisting may occur in the electric resistance welded pipe P during the process of forming the pipe. Therefore, if the direction of the elliptical roll 30 is not changed, the relative position between the welded portion 4 and the elliptical roll 30 may be shifted due to the twist of the ERW pipe P. FIG. 4 shows a modification in which the elliptical roll 30 can be turned around the pipe axis of the ERW pipe P in order to cope with such a twist of the ERW pipe P. The same reference numerals are given and the description is omitted.

In FIG. 4, arms 56 are formed on the support frame 52 so as to protrude to the side, and these arms 56 are fixed to a support 58 that stands upright from a base (not shown) via a fastening means 62. . The support columns 58 are formed with curved long holes 60, and fastening means 62 are passed through these long holes 60.
Therefore, when the fastening means 62 is loosened, the entire support frame 52 can be turned around the pipe axis of the electric resistance welded pipe P, whereby the welded portion 4 can be matched with the major axis or minor axis. However, the mechanism for turning the elliptical roll 30 is not limited to the structure as shown in FIG. 4, and any known turning structure can be adopted.

When turning the elliptical roll 30,
It is preferable to apply the same kind of turning structure to at least the first-stage sizing roll 32. This is because if the axis of the first-stage sizing roll 32 can be maintained at 90 ° with respect to the axis of the elliptical roll 30, the elliptical ERW pipe P can be easily returned to the circular cross section by the sizing roll 32. Note that the configuration of the sizing roll 32 may be the same as that of the related art, that is, the elliptical ERW pipe P may be returned to a circular shape and reduced in diameter to a predetermined outer diameter. Even if the cross section is returned to the circular shape by the sizing roll 32, the defect whose mouth is opened due to the ovalization is not completely closed, and the eddy current flaw detector 40 can easily find the defect. In addition, it can be easily found by a leak test using helium gas or the like.

FIG. 9 shows an example of the basic structure of the eddy current flaw detector 40 shown in FIG. The eddy current flaw detector 40 of this example has at least two coils 70, 72, and these coils 70, 7
While supplying a high-frequency current to each of the two, the inductances of the two are compared. Therefore, when a defective portion of the ERW pipe P passes through one of the coils, a difference occurs between the inductances of the two and a defect is detected. However, the flaw detection mechanism used in the present invention is not limited to the eddy current flaw detector having the basic structure shown in FIG. 9, and an eddy current flaw detector of a type that integrates signals using three or more coils can be used. Further, various flaw detection sensors based on an operation principle other than the eddy current flaw detection may be used.
Examples of such a flaw detection sensor include an optical flaw detection sensor and an ultrasonic flaw detection sensor.

Next, an embodiment of a method for manufacturing an ERW pipe using the ERW pipe manufacturing apparatus having the above configuration will be described. In this method, first, a plate material T having a constant width is continuously fed out from the uncoiler 10, and the fed plate material T is passed through a pair of holding rolls 12 to form a grooved roll 14 and a receiving roll 1.
6 and by a grooved roll 14, for example, as shown in FIG.
The fin 2 and the spiral groove 3 as illustrated in FIG.

Next, as shown in FIG. 1, the grooved plate material T is gradually rolled into a tube through a pair of rolls 18 and a plurality of forming rolls 20 arranged in a pair, and then abutted by a rolling separator 21. The distance (gap amount) between both edges to be kept is kept constant. Then, the two side edges of the plate material T are heated by passing through the induction heating coil 22, and furthermore, are pushed from both sides through a pair of squeeze rolls 24 so that the both side edges are butted and welded. Since a bead is generated by the protruding molten material on the outer peripheral surface of the ERW pipe P, the bead is cut by the bead cutter 26.

The ERW pipe P from which the beads have been cut is placed in the cooling bath 28.
, And forced through an elliptical roll 30. These elliptical rolls 30 may or may not be driven in synchronization with the flow of the ERW tube P. Elliptical roll 3
0, the electric resistance welded pipe P having a circular cross section as shown in FIG.
Is flattened to have an elliptical cross section in a state of being substantially coincident with the major axis. As a result, when a defect K1 that appears to be normal at first glance is latent on the outer peripheral surface side of the welded portion 4 as shown in FIG. 6A, the defect K1 is expanded by stress as shown in FIG. Crack K2.

Next, the elliptical ERW pipe P is passed through a plurality of pairs of sizing rolls 32, and is returned to a circular cross section again as shown in FIG. Until the diameter is reduced. If there is a crack K2 in the ERW pipe P, the opening width is reduced by circularization, but the crack once opened is not completely closed, and a slight crack remains regardless of the subsequent processing. Become.

The electric resistance welded pipe P whose diameter has been reduced to the outer diameter of the product is roughly wound by a rough coiler 33 and formed into a coil.
Is transferred to the uncoiler 34 of the subsequent device shown in FIG. In addition,
The reason why the processing is divided into the former stage and the latter stage is that the respective processing speeds are different, and if the processing speeds can be made the same, it is natural that they can be combined into one line.

The electric resistance welded pipe P is continuously fed out from the uncoiler 34, passed through a roll 36 and passed through a straightener 38, and straightened. The straightened electric resistance welded pipe P is passed through the eddy current flaw detector 40, and the presence or absence of a defect is determined based on the principles exemplified above. The electric resistance welded tube P manufactured in this embodiment is a heat transfer tube with an inner surface groove having a spiral groove 3 and a fin 2 formed on the inner surface thereof. Inspection cannot be performed because noise is picked up. However, in this embodiment, the latent defect K1 due to the action of the elliptical roll 30 is previously removed from the crack K1.
2, the defect detection capability can be sufficiently increased without forcibly increasing the sensitivity of the eddy current flaw detector 40.

When the eddy current flaw detector 40 detects a defect, the control mechanism 41 operates the ink spraying mechanism 43 to spray quick-drying ink on the outer peripheral surface of the electric resistance welded pipe P.
Thereby, the defective portion of the ERW pipe P is marked, so that the user can use the ERW tube P except for the defective portion. After the inspection, the electric resistance welded pipe P is aligned and wound by the alignment winding device 46 to complete a product coil.

According to the apparatus and method for manufacturing an electric resistance welded pipe having the above configuration, the defect K1 latent in the welded portion 4 of the electric resistance welded pipe P is changed into a crack by the elliptical roll 30, and thereafter, Since the defect is inspected by the eddy current flaw detector 40 after the cross section is returned to the original circular shape, the reliability of defect detection can be improved, and the quality reliability of the ERW pipe P as a product can be improved. is there.

In addition, in this apparatus and method, since only the elliptical roll 30 is substantially newly added, there is an advantage that a remarkable effect can be obtained without increasing the equipment cost so much. In addition, in this apparatus and method, since the defective portion of the ERW pipe P can be automatically marked by the ink spraying mechanism 43, only the defective portion of the long ERW pipe P can be discarded. , Can increase the yield.

Further, since the defects revealed by the elliptical roll 30 remain later, even if some of the defects are not detected by the eddy current flaw detector 40, helium gas or the like performed on the product coil is used. The effect that the probability of discovery by the gas leak test can be increased is also obtained.

[Second Embodiment] In the above-described first embodiment, only one pair of the elliptical rolls 30 is provided to make the ERW pipe P elliptic only once.
(The first elliptical mechanism) and the sizing roll 32,
By arranging another pair of elliptical rolls (second elliptic mechanism) in a direction in which the axis is orthogonal to the elliptical roll 30, it is possible to make the ellipse twice as shown in FIG.

In this case, the first ovalization is performed as shown in FIG.
It is desirable to match the major axis of the ellipse with the welded portion 4 as shown in FIG. 7, and to match the minor axis of the ellipse with the welded portion 4 as shown in FIG. When the ellipse is formed in two stages in this manner, as shown in FIG. 8B, in the first ovalization, the defect K1 latent on the outer peripheral surface of the welded portion 4 is revealed as a crack K2. In the ellipsoidalization, the defect K1 latent on the inner peripheral surface of the welded portion 4 is replaced with the crack K
3 can be realized. After the defect is made obvious, the cross section may be circularized again by the sizing roll 32 and the diameter may be reduced as in the previous embodiment.

According to the second embodiment, latent defects on both the outer peripheral surface and the inner peripheral surface of the welded portion 4 can be revealed, and the probability of finding a latent defect can be increased. Can be significantly increased. Note that, of course, the directions of the first and second ovalizations may be reversed.

[Third Embodiment] FIG. 10 is a side view showing a third embodiment of the apparatus for manufacturing an electric resistance welded pipe according to the present invention.
In each of the above two embodiments, the cross section of the electric resistance welded pipe P is made elliptical, then the cross section is made circular by the sizing roll 32, and then passed through the eddy current flaw detector 40. The main change is that the eddy current flaw detector 40 is disposed between the eddy current flaw detector 40 and the sizing roll 32, and the electric resistance welded pipe P, which has been made elliptical by the elliptical roll 30, is immediately passed through the eddy current flaw detector 40.

According to such a configuration, the eddy current flaw detector 4 is changed in a state where the latent defect is changed to a crack having a large opening width.
0, the reliability of defect detection can be further improved, or the inspection accuracy of the eddy current flaw detector 40 can be reduced without lowering the reliability of defect detection. is there. If the inspection accuracy of the eddy current flaw detector 40 can be reduced, the probability of an inspection error caused by noise caused by the fins 2 and the spiral grooves 3 should be reduced particularly when applied to the manufacture of a heat transfer tube with an inner surface groove. And yield can be improved.

Also, in this embodiment, instead of the ink spraying mechanism 43 used in the previous embodiment, a mark mechanism 74 of a type in which a part of the outer peripheral surface of the electric resistance welded pipe P is depressed is used. This is the second feature. When the mark mechanism 74 receives an operation signal from the control mechanism 41, the built-in actuator protrudes the roller 76 toward the ERW pipe P to depress a part of the outer peripheral surface of the ERW pipe P. The use of such a mark mechanism 74 has the advantage that there is no danger of falling off like ink or of contaminating others.

In each of the above embodiments, the ERW pipe P
The fin 2 and the helical groove 3 are formed on the inner surface of the ERW. However, the present invention can be applied to a simple ERW pipe without the fin 2 and the helical groove 3. The present invention can be applied to a device for forming dimples or the like on the wall surface of the electric resistance welded pipe P, and can also be applied to a case where fins or dimples are formed on the outer surface of the ERW pipe P. In each of the above embodiments, one-step groove rolling is performed by the grooved rolls 14. However, two or more grooved rolls are used to form grooves in two or more steps, and two types of grooves are crossed. It is also possible to form a cross groove or the like on the inner surface and / or outer surface of the heat transfer tube.
Further, the present invention is also applicable to a case where a large number of short fins divided in the longitudinal direction are formed along a staggered or spiral line.

Although the above embodiments relate to an apparatus for manufacturing an electric resistance welded tube, only the configuration of the elliptical roll 30, the eddy current flaw detector 40, the sizing roll 32, and the like are taken out and an independent electric resistance welded tube is manufactured. It goes without saying that the inspection device may be used. In this case, the completed ERW pipe P can be inspected with high accuracy. Further, as an elliptical mechanism for making the ERW tube elliptical, an elliptical roll 3 is used.
Other means may be used instead of 0. For example, a drawing die or the like can be used.

[0046]

As described above, according to the ERW pipe inspection apparatus, the ERW pipe manufacturing apparatus and the manufacturing method according to the present invention, a defect latent in the welded portion of the heat transfer pipe can be cracked by the elliptic mechanism. After the change, the defect can be inspected by the flaw detection mechanism, so that the reliability of defect detection can be improved.

[Brief description of the drawings]

FIG. 1 is a side view showing a first stage of a first embodiment of an electric resistance welded pipe manufacturing apparatus according to the present invention.

FIG. 2 is a side view showing a rear stage of the device.

FIG. 3 is a front view showing an elliptical mechanism of the device.

FIG. 4 is a front view showing a modification of the elliptical mechanism of the device.

FIG. 5 is a cross-sectional view of an electric resistance welded tube showing an elliptical action by the device.

FIG. 6 is an enlarged sectional view of a welded portion showing an effect of ellipticalization by the device.

FIG. 7 is a cross-sectional view of an electric resistance welded pipe showing an elliptical action according to a second embodiment of the apparatus for producing an electric resistance welded pipe according to the present invention.

FIG. 8 is an enlarged sectional view of a welded portion showing an effect of ellipticalization according to the second embodiment.

FIG. 9 is an explanatory diagram showing the principle of an eddy current flaw detector as an example of a flaw detection mechanism.

FIG. 10 is a side view showing a third embodiment of the apparatus for manufacturing an electric resistance welded pipe according to the present invention.

FIG. 11 is an enlarged cross-sectional view showing an inner grooved heat transfer tube as an example of an electric resistance welded tube to which the present invention can be applied.

[Explanation of symbols]

 Reference Signs List 1, 1 Heat transfer pipe with inner groove (electrically welded pipe) 2 Fin 3 Spiral groove 4 Welded part 10, 34 Uncoiler (part of ERW pipe transport mechanism) T Plate strip 14 Grooved roll 20 Forming roll (Pipe forming mechanism) 22) Induction heating coil (welding mechanism) 30 Elliptical roll (elliptical mechanism) 33 Rough coiler (part of ERW pipe transport mechanism) 40 Eddy current flaw detector (flaw detection mechanism) 41 Control mechanism 43 Ink spraying mechanism (mark mechanism) 46 Alignment winding device (part of the electric resistance welded tube transport mechanism) D1 major axis dimension D2 minor axis dimension 58, 60, 62 rocking mechanism K1 latent defect K2, K3 crack 74 mark mechanism

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshizo Nishimaki 128-7 Ogimachi, Aizuwakamatsu-shi, Fukushima Prefecture Inside Wakamatsu Works, Copper Co., Ltd. (72) Inventor Yoshihito Haga 7-27, 128 Ogimachi, Aizuwakamatsu-shi, Fukushima Prefecture (72) Inventor Yoshikatsu Arayama 128-7 Ogimachi, Aizuwakamatsu City, Fukushima Prefecture Mitsubishi Shindoh Wakamatsu Plant (56) References JP-A-63-249050 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B21C 37/08 B23K 31/00 G01N 27/82-27/90

Claims (9)

(57) [Claims] 1. An electric resistance welded tube transport mechanism for causing an electric resistance welded tube to travel in a longitudinal direction of the electrical resistance welded tube.
An elliptical mechanism for revealing welding defects latent in the ERW pipe, a circularization mechanism for returning an ERW pipe having an elliptical cross section to a circular cross section, and an ERW pipe with a circular cross section Flaw detection mechanism for detecting the revealed defects of the above, the elliptical mechanism sandwiches an electric resistance welded tube between the outer peripheral surfaces of each other
A pair of elliptical rolls that rotate while compressing, and these ellipses
So that the forming roll can rotate around the pipe axis of the ERW pipe.
A roll support mechanism for supporting the circularized roll,
An inspection apparatus for an electric resistance welded pipe, wherein an outer peripheral surface of the elliptical roll has an arc-shaped cross section . 2. An electric resistance welded pipe conveying mechanism for moving the electric resistance welded pipe in the longitudinal direction thereof, and by deforming the traveling electric resistance welded pipe into an elliptical cross section.
An elliptical mechanism for revealing a welding defect latent in the ERW pipe; a flaw detection mechanism for detecting the revealed defect of the ERW pipe having an elliptical cross section; and an elliptical cross section. A circularization mechanism for returning the ERW pipe to a circular cross section , wherein the elliptical mechanism sandwiches the ERW pipe between the outer peripheral surfaces of the ERW pipes.
A pair of elliptical rolls that rotate while compressing, and these ellipses
So that the forming roll can rotate around the pipe axis of the ERW pipe.
A roll support mechanism for supporting the circularized roll,
An inspection apparatus for an electric resistance welded pipe, wherein an outer peripheral surface of the elliptical roll has an arc-shaped cross section . 3. The ERW pipe inspection apparatus according to claim 1, wherein the flaw detection mechanism is an eddy current flaw detector. 4. The elliptical direction by the elliptic mechanism is:
The electric resistance welding according to any one of claims 1 to 3, wherein the major axis direction is set so as to be substantially parallel or substantially perpendicular to a direction connecting the center of the electric resistance welded tube and the welded portion. Pipe inspection equipment. 5. The ratio of the major axis to the minor axis of the ERW tube to be elliptical by the elliptic mechanism is 1.3: 1 to 1.9:
The inspection device for an electric resistance welded tube according to claim 1, wherein the inspection device is set to 1. 6. The elliptical mechanism has a first elliptical mechanism and a second elliptical mechanism, and the direction of ellipticalization by one of the first elliptical mechanism and the second elliptical mechanism is the major axis of the ellipse. The direction is set substantially parallel to the direction connecting the center of the ERW pipe and the welded part, and the direction of ellipticalization by the other is that the major axis direction of the ellipse connects the center of the ERW pipe and the welded part The inspection device for an electric resistance welded tube according to any one of claims 1 to 3 , wherein the inspection device is set to be substantially perpendicular to the direction. 7. A tube forming mechanism for forming a metal strip into a tubular shape while running the metal strip through a plurality of forming rolls, and heating both end edges of the tubular shaped strip. A welding mechanism that makes the ERW pipe by butt-welding, and by deforming the running ERW pipe into an elliptical cross section,
An elliptical mechanism for revealing welding defects latent in the ERW pipe, a circularization mechanism for returning an ERW pipe having an elliptical cross section to a circular cross section, and an ERW pipe with a circular cross section Flaw detection mechanism for detecting the revealed defects of the above, the elliptical mechanism sandwiches an electric resistance welded tube between the outer peripheral surfaces of each other
A pair of elliptical rolls that rotate while compressing, and these ellipses
So that the forming roll can rotate around the pipe axis of the ERW pipe.
A roll support mechanism for supporting the circularized roll,
An apparatus for manufacturing an electric resistance welded pipe, wherein the outer peripheral surface of the elliptical roll has an arc-shaped cross section . 8. A tube forming mechanism for forming a metal strip into a tube while passing the metal strip through a plurality of forming rolls, and heating both end edges of the tube-shaped strip. A welding mechanism that makes the ERW pipe by butt-welding, and by deforming the running ERW pipe into an elliptical cross section,
An elliptical mechanism for revealing a welding defect latent in the ERW pipe; a flaw detection mechanism for detecting the revealed defect of the ERW pipe having an elliptical cross section; and an elliptical cross section. A circularization mechanism for returning the ERW pipe to a circular cross section , wherein the elliptical mechanism sandwiches the ERW pipe between the outer peripheral surfaces of the ERW pipes.
A pair of elliptical rolls that rotate while compressing, and these ellipses
So that the forming roll can rotate around the pipe axis of the ERW pipe.
A roll support mechanism for supporting the circularized roll,
An apparatus for manufacturing an electric resistance welded pipe, wherein the outer peripheral surface of the elliptical roll has an arc-shaped cross section . 9. An electric resistance welded pipe manufacturing apparatus according to claim 7, further comprising a mark mechanism for forming a mark on a portion of the electric resistance welded pipe where a defect is detected by the flaw detection mechanism. .