MANUFACTURING METHOD AND MANUFACTURING APPARATUS
FOR UOE STEEL PIPE OR TUBE
Technical Field
[0001]
The present invention relates to a manufacturing method and
manufacturing apparatus for a UOE steel pipe or tube (hereinafter
referred to as "pipe" when deemed appropriate). To be specific, it relates
to a method and apparatus for manufacturing a UOE steel pipe while
suppressing manufacturing man-hours and a deterioration of yield by, for
example, accurately measuring the cross-sectional shape of a bevel that is
formed in an edge part of a thick plate which is a blank steel plate.
Background Art
[0002]
In a typical manufacturing process of a UOE steel pipe, a cutting
machine is first used to bevel an edge part of a steel plate, which is the
starting material, in preparation for welding. In particular, in
manufacturing of a large diameter UOE steel pipe having an outer
diameter of about 20 to 60 inches, beveling is carried out for forming a
bevel for welding by a cutting machine called an edge planer with a
cemented carbide bite to cut out an edge part of a thick plate (a plate
thickness of 6 to 50 mm) in accordance with its outer diameter.
[0003]
The beveled steel plate is successively subjected to C-pressing, Upressing,
and 0-pressing into an open-pipe having an 0-shape cross
2
section. Thereafter, the edge parts of the open pipe, which have beveled,
are butted together and welded, and thereafter an expansion processing
is carried out to form a UOE steel pipe.
[0004]
For example, Patent Literature 1 (JP2005-2884 71A) discloses a
method for manufacturing a UOE steel pipe.
Summary of Invention
Technical Problem
[0005]
In a conventional manufacturing process of UOE steel pipe, in
order to determine whether or not a normal bevel has been formed by
beveling, it is necessary to sample a welding bead of a pipe end surface of
the UOE steel pipe after welding, grind the end surface of the sampled
welding bead by using a file and a grinding stone, and further estimate
the bevel shape from the bead shape after pickling.
[0006]
This means that, after the edge parts of the open pipe are welded
together, there is no other way to determine whether or not the bevel
shape is appropriate than to estimate it based on the fused state between
the weld metal and the base metal, and it takes much time until to
determine that the bevel shape is not appropriate.
[0007]
Further, even if it is assumed that a defect of bevel shape of one
manufactured UOE steel pipe can be observed and found after welding,
3
similar inappropriate beveling may have been performed when the defect
has been found, on a large number of thick plates, which are the starting
material of many other UOE steel pipes that are manufactured following
the aforementioned one UOE steel pipe. For this reason, since it
becomes necessary to additionally cut the bevels of the large number of
thick plates, the production efficiency of UOE steel pipe will be
significantly deteriorated.
[0008]
In particular, if a thick plate is fed to a C-press machine in the next
process with a machined chip attached to the bevel, which has been
generated during beveling, the machined chip, if detached from the bevel
during C-pressing, falls into the die of the C-press machine and adheres
to the die. Thus, a further problem is that the machined chip adhering
to the die of the C-press machine causes a dent flaw on the outer surface
of the UOE steel pipe, which is made of a thick plate as a starting
material that is to be fed to the C-press machine after the above described
thick plate.
[0009]
These are technical problems that are desired to be solved promptly,
because they directly lead to an increase in manufacturing man-hours
and a decline of yield of the UOE steel pipe.
Solution to Problem
[0010]
4
The present invention is a method for manufacturing a UOE steel
pipe or tube in which a steel plate provided with a bevel in an edge part
thereof is successively subjected to C-pressing, U·pressing, and apressing
into an open pipe or tube, and bevels of the open pipe or tube are
butted together and welded, wherein a shape of the bevel of the steel
plate is measured prior to the C·pressing and determination is made
based on the measurement result whether there is a need for modifying
the shape of the bevel of the steel plate before the C-pressing is started.
[0011]
From another aspect, the present invention is an apparatus for
manufacturing a UOE steel pipe or tube including: a beveling device for
forming a bevel in an edge part of a steel plate; a conveyance system for
conveying the beveled steel plate; a steel pipe or tube forming device
including a C·press machine, aU-press machine, and an 0-press machine,
and for shaping the beveled steel plate into an open pipe or tube; and a
welding machine for butting the bevels of the open pipe or tube and
welding the same, wherein the apparatus further includes a bevel-shape
measurement device for measuring the shape of the bevel of the steel
plate prior to C-pressing carried out by the C-press machine, between the
beveling device and the C·press machine, and the bevel-shape
measurement device determines whether there is a need for modifying
the shape of the bevel of the steel plate before the C-pressing is started
based on the measurement result of the shape of the bevel.
[0012]
5
In these aspects of the present invention, it is preferable that the
shape of the above described bevel is measured by a light-section method
that irradiates the edge part of the above described steel plate with a
linear laser beam that expands in the thickness direction of the above
described steel plate.
In these aspects of the present invention, it is preferable that a
plurality of the above described linear laser beams are applied in the
conveyance direction of the above described steel plate.
[0013]
Further, in these aspects of the present invention, it is preferable
that after the above described bevel is formed, the above described steel
plate is conveyed with a conveyor roller up to the C-press machine which
applies C-press, and the shape of the above described bevel is measured
in the vicinity of the conveyor roller and at an exit side of the conveyance
direction of the above described steel plate.
Advantageous Effects of Invention
[0014]
According to the present invention, it is possible to accurately
measure the cross-sectional shape of the bevel formed in the edge part of
the blank steel plate, for example, a thick plate etc. before C-pressing is
started, and specifically it is possible to determine whether or not the
shape of the bevel formed in the edge part of the steel plate by a beveling
device such as an edge planer is appropriate by using a dedicated bevelshape
measurement device for measuring the bevel shape of the blank
6
steel plate, and quickly output the need for modifying the shape of the
bevel to the operator when necessary. This makes it possible to
manufacture a UOE steel pipe or tube while preventing an increase in
man· hours and a decline of yield caused by inappropriateness of the
shape of the bevel.
Brief Description of Drawings
[0015]
Figure 1 is an explanatory diagram to schematically show the
outline of an embodiment of the present invention.
Figure 2 is an explanatory diagram to show an example of the
shape of the bevel of the thick plate.
Figure 3 is an explanatory diagram to show a situation where the
two-dimensional laser range meters measure the shape of the bevels of
the thick plate.
Figure 4A is an explanatory diagram to show a case where the
thick plate has a semicylindrical shape, and Figure 4B is an explanatory
diagram to show a case where a front edge of the thick plate has a warped
shape.
Figure 5 is an explanatory diagram to show the positional
relationship between the conveyor roller and the bevel-shape
measurement device.
Figure 6 is a graph to show an example of the measurement result
of the shape of the bevel by the bevel-shape measurement device.
7
Figure 7 is an explanatory diagram to schematically show the
procedure of a test for verifying that the bevel-shape measurement device
can detect the presence or absence of a foreign substance.
Figure 8 is a graph to show an example of the result of the test
shown in Figure 7.
Figure 9 is a graph to show an example of the result of the test
shown in Figure 7.
Figure 10 is a graph to show an example of the result of the test
shown in Figure 7.
Figure 11 is a graph to show an example of the result of the test
shown in Figure 7.
Description of Embodiments
[0016]
Hereafter, an embodiment for carrying out the present invention
will be described with reference to the appended drawings.
First, the manufacturing apparatus relating to the present
embodiment will be described. Figure 1 is an explanatory diagram to
schematically show the outline of the present embodiment.
[0017]
As shown in Figure 1, a manufacturing apparatus 1 relating to the
present embodiment includes a beveling device 2, a conveyance system 3,
a steel pipe forming device 4, a welding device 5, and a bevel-shape
measurement device 6. Hereafter, these components will be successively
described.
8
[0018]

The beveling device 2 is a device for forming a bevel in edge parts
7a and 7b of a thick plate (a steel plate having a plate thickness of about
6 to 50 mm) 7 which is the starting material of a large diameter UOE
steel pipe 30 having an outer diameter of about 20 to 60 inches.
[0019]
As the beveling device 2, a known, ordinary device may be used,
which may be exemplified by an edge planer that uses a cemented carbide
bite for performing the machining of the edge parts 7 a and 7b of the thick
plate 7.
[0020]
Since the beveling device 2 is well known to one skilled in the art,
further description on the beveling device 2 will be omitted.
[0021]

The conveyance system 3 is a device for conveying the thick plate 7,
whose edge parts 7a and 7b are provided with bevels 8a and 8b, to the
steel pipe forming device 4. The conveyance system 3 is made up of a
large number of conveyor rollers 9 which are placed side by side in the
conveyance direction.
[0022]
After the bevels 8a and 8b are formed, the thick plate 7 is conveyed
by the large number of conveyor rollers 9 making up the conveyance
system 3 to a C·press machine 10 where C·pressing is carried out.
9
Since the conveyance system 3 is well known to one skilled in the
art, further description on the conveyance system 3 will be omitted.
[0023]

The steel pipe forming device 4 is a device including a C-press
machine 10, aU-press machine 11, and an 0-press machine 12, and for
shaping the thick plate 7, which is provided with bevels 8a and 8b, into
an open pipe 13.
[0024]
Since the steel pipe forming device 4 is well known to one skilled in
the art, further description on the steel pipe forming device 4 will be
omitted.
[0025]

The welding device 5 is a device for butting the bevels 8a and 8b of
the open pipe 13 together and welding the same. Since the welding
device 5 is well known to one skilled in the art, further description on the
welding device 5 will be omitted.
[0026]
It is noted that the steel pipe 14 which has been welded by the
welding device 5 is subjected to expansion processing by an expansion
processing device 15 into a DOE steel pipe 30 which is the product.
[0027]

10
A bevel-shape measurement device 6 is a device disposed between
the beveling device 2 and the C-press machine 10 and for measuring the
shape of the bevels 8a and 8b of the thick plate 7 before C-pressing by the
C-press machine 10 is carried out.
[0028]
The bevel-shape measurement device 6 determines whether there
is a need for modifying the shape of the bevels 8a and 8b of the thick plate
7 before C-pressing is started for the thick plate 7 by the C-press machine
10. The bevel-shape measurement device 6 includes two-dimensional
laser range meters 18a and 18b for measuring bevel shapes by a lightsection
method, and a determination device 61 for determining whether
there is a need for modifying the bevel shapes.
[0029]
A main feature of the manufacturing apparatus 1 is that the bevelshape
measurement device 6 which has a function of detecting the shapes
of the bevels 8a and 8b of the thick plate 7 preferably by a light-section
method that irradiates the edge parts 7a and 7b of the thick plate 7 with
linear laser beams 16a and 16b, and if there is an abnormality in the
shapes of the bevels 8a and 8b, notifying the abnormality to the operator
17 is disposed between the beveling device 2 such as an edge planer, and
the C-press machine 10.
[0030]
While a UOE steel pipe 30 is generally manufactured by a device in
which the bevel-shape measurement device 6 is omitted from the
manufacturing apparatus 1 shown in Figure 1, it is often the case that
11
the thick plate 7, which is an intermediate product provided with the
bevels 8a and 8b, is put on a temporary standby such as between the
beveling device 2 (for example, an edge planer) and the C-press machine
10 because of balancing between the respective process capacities.
[0031]
In the present embodiment, the bevel-shape measurement device 6
is newly placed immediately downstream the beveling device 2 such as an
edge planer, and a measurement result of the bevel-shape measurement
device 6 is fed back to the operator 17 so that the operator 17 can take
necessary measures for the bevels 8a and 8b of the thick plate 7 before
the C-pressing by the C-press machine 10 is carried out.
[0032]
The method for the feedback to the operator 17 may be
appropriately chosen, without being particularly limited, in accordance
with the configuration of manufacturing process: for example, (1) a
method of just notifying the operator by issuing an alarm, (2) a method of
temporarily halting the conveyance system 3 in automatic fashion with
an alarm, and the like.
[0033]
A difference between an appropriate shape of bevels 8a and 8b
which is input in advance and the measured shape of bevels 8a and 8b is
detected from a measurement result of the shape of the bevels 8a and 8b
of the thick plate 7 by the bevel-shape measurement device 6, and if the
difference deviates from a reference range, it can be determined that the
shape of the bevels 8a and 8b is defective. It is desirable that, by
12
determining that the shape of the bevels 8a and 8b is defective when a
plurality of linear laser beams 16a and 16b are applied in the conveyance
direction of the thick plate 7 and two or more cases as described above are
detected, it may be possible to prevent accidental malfunctions thereby
enhancing the reliability of the bevel-shape measurement device 6.
[0034]
The measurement of the shape (cross-sectional shape) of the bevels
8a and 8b of the thick plate 7 by the bevel-shape measurement device 6 is
carried out by measuring the distance in the width direction of the thick
plate between the bevels 8a and 8b of the thick plate 7 and the twodimensionallaser
range meters 18a and 18b by using the linear laser
beams 16a and 16b. Then, by way of example, a difference from an
appropriate cross-sectional shape of the bevels 8a and 8b which is
inputted in advance is detected, and when this difference is not less than
5 mm, it is determined that a defective shape has occurred in the bevels
8a and 8b.
[0035]
Figure 2 is an explanatory diagram to show an example of the
shape ofthe bevel8b of the thick plate 7 (the relationship between the
angle and the thickness in the plate thickness direction). It is noted that
since the bevel 8a is formed in symmetrical with the bevel 8b, Figure 2
will be described by taking the bevel 8b as example.
[0036]
It is possible to measure angles (9 1 to 93) of various portions of the
bevel8b, and thicknesses (X1 to X3) in the plate thickness direction
13
having angles (91 to 93) in numeral forms by the bevel-shape
measurement device 6. For this reason, the operator 17 can easily
adjust the setting of a cemented carbide bite of the beveling device 2 (for
example, an edge planer) based on the angles (91 to 93) and the
thicknesses (X1 to X3) of the bevel 8b.
[0037]
Figure 3 is an explanatory diagram to show a situation where the
two-dimensional laser range meters 18a and 18b measure the shape of
the bevels 8a and 8b of the thick plate 7.
A frame 19 is fixedly disposed by being bridged over across the
width of the thick plate 7 above the thick plate 7 to be conveyed by the
conveyor roller 9. The two-dimensional laser range meter 18b is fixedly
disposed via a bracket 20 which is fixedly disposed on one end side of the
frame 19. On one hand, the two-dimensional laser range meter 18a is
disposed movably in the width direction of the thick plate 7 via a bracket
22 which is disposed to be movable in the width direction of the thick
plate 7 with respect to the frame 19 by a stepping motor 21. This
provides the two-dimensional laser range meter 18a that is configured to
automatically move to a position suitable for measurement in accordance
with the width of the thick plate 7.
[0038]
Figure 4A is an explanatory diagram to show a case where the
thick plate 7 has a semicylindrical shape, and Figure 4B is an
explanatory diagram to show a case where a front edge of the thick plate
7 has a warped shape.
14
The two-dimensional laser range meters 18a and 18b, which
measure the cross-sectional shape of a part irradiated with the linear
laser beams 16a and 16 by using a light-section method that irradiates
the edge parts 7 a and 7b of the thick plate 7 with the linear laser beams
16a and 16b, radiate linear laser beams 16a and 16b divergently as
shown in Figures 1 and 3. As a result, setting a laser detection range L
to be not less than a supposed movable range in the vertical direction of
the cross section of the thick plate 7 as shown in Figure 4A makes it
possible to measure the shape of the entire cross section of the bevels 8a
and 8b of the thick plate 7 even in a case where the thick plate 7 has a
semicylindrical shape as shown in Figure 4A, and a case where a front
edge of the thick plate 7 has a warped shape as shown in Figure 4B.
[0039]
Figure 5 is an explanatory diagram to show the positional
relationship between the conveyor roller and the bevel-shape
measurement device 6 (the two-dimensional laser range meters 18a and
18b).
Since the thick plate 7 is stably conveyed in the vicinity of the
conveyor roller 9, disposing a laser beam radiation port of the two·
dimensional laser range meters 18a and 18b near the conveyor roller 9
will make it possible to detect the shape of the bevels 8a and 8b in a
stable manner.
[0040]
The laser beam radiation port of the two-dimensional laser range
meters 18a and 18b is preferably disposed on the downstream side of the
15
conveyor roller 9 in the conveyance direction of the thick plate 7,
specifically, at a position of about 500 mm on the downstream side of the
conveyor roller 9 in the conveyance direction, because a stable
measurement becomes possible. As a result, even when the thick plate 7
is relatively thin, the measurement is less likely to susceptible to a
warping of the front edge of the thick plate 7, and accurate measurement
can be performed.
[0041]
Further, since the bevels Sa and Sb have a luster like a mirror
surface, if the linear laser beams 16a and 16b are radiated in an
arrangement such that a specularly reflected light of the linear laser
beams 16a and 16b will be incident into light receiving elements of the
two-dimensional laser range meters 1Sa and 1Sb, the reflected light will
become too strong thereby causing noises and accurate measurement
becomes difficult. For this reason, it is preferable to dispose the two·
dimensional laser range meters 1Sa and 1Sb, for example, 5 to 10°
inclined with respect to the conveyance direction of the thick plate 7 from
the above described arrangement so that the amount of the reflected light
is suppressed by slantedly irradiating the bevel with the linear laser
beams 16a and 16b.
[0042]
In this way, it is preferable that the bevel-shape measurement
device 6 measures the shape of the bevels Sa and Sb of the thick plate 7
by using the linear laser beams 16a and 16b which expands in the
thickness direction of the thick plate 7. Moreover, it is preferable that
16
the bevel-shape measurement device 6 measures the shape of the bevels
8a and 8b in the vicinity of the conveyor roller 9 and at the exit side in
the conveyance direction of the thick plate 7.
[0043]
Figure 6 is a graph to show an example of the measurement result
of the shape of the bevel8b by the bevel-shape measurement device 6.
Since the bevel 8b is measured in the thickness direction and the width
direction of the thick plate 7 as shown by the graph in Figure 6, the crosssectional
shape of the entire bevel 8b is accurately measured.
[0044]
It is preferable to arrange side by side a plurality (two in the
example shown in Figure 5) of the two-dimensional laser range meters
18a and 18b making up the bevel-shape measurement device 6.
For example, it is preferable that the bevel-shape measurement
device 6 measures the shape of the bevels 8a and 8b at a pitch of about 10
mm in the conveyance direction of the thick plate 7, from the viewpoint of
the reliability of measured values. Supposing that the conveyance speed
of the thick plate 7 is, for example, 60 m/min, it is preferable that two
two-dimensional laser range meters 18a-1, 18a·2 and 18b-1, 18b-2 (these
are not shown) are arranged on one side in the conveyance direction as
shown in Figure 5, and each of the two-dimensional laser range meters
18a-1, 18a-2 and 18b-1, 18b-2 measures the shape of the bevels 8a and 8b
of the thick plate 7 at the same period of about 20 ms pitch, and shifts the
position of the linear laser beam to be radiated by 10 mm respectively
between the two-dimensional laser range meter 18a-1 and the two-
17
dimensional laser range meter 18a·2, and between the two-dimensional
laser range meter 18b-1 and the two-dimensional laser range meter 18b-2
to perform measurement accurately at a pitch of 10 mm.
[0045]
It is desirable to provide a warping suppressor 23 as shown in
Figure 5 before the two-dimensional laser range meters 18a and 18b
making up the bevel-shape measurement device 6. The warping
suppressor 23 has a roof-type steel plate 23a whose height decreases from
a plate entrance side toward the plate conveyance direction, and it is
possible to suppress a warping of, for example, not less than 80 mm which
takes place in the thick plate 7 caused by the roof-type steel plate 23a.
[0046]
Further, since the bevel-shape measurement device 6 can measure
the shape of the bevels 8a and 8b of the thick plate 7 at a high accuracy,
it has a foreign-substance adherence detection function to detect not only
defects in the shape of the bevels 8a and 8b themselves, but also the
presence or absence of adherence of foreign substances (for example,
machined chips) to the bevels 8a and 8b (in the present invention,
adherence of foreign substances is also regarded as a kind of defective
shape).
[0047]
For example, if the shape measured by the bevel-shape
measurement device 6 deviates by 5 mm or more from an appropriate
shape, an alarm sounds notifying the operator 17 of adherence of a
foreign substance to the bevels 8a and 8b.
18
Figure 7 is an explanatory diagram to schematically show the
procedure of a test for verifying that the bevel-shape measurement device
6 can detect the presence or absence of a foreign substance (for example,
machined chips) adhering to the bevels 8a and 8b.
[0048]
In this test, a machined chip 25 is caused to adhere to various
positions of a tentative work 24 which imitates a thick plate, and a linear
laser beam 27 is radiated from a two-dimensional laser range meter 26
(trade name LJ-G200 manufactured by KEYENCE CORPORATION)
toward the tentative work 24 and the machined chip 25, and the
reflection light thereof is detected to measure the shape. The shape is
also measured without the machined chip 25 being adhered thereto.
[0049]
Measurement results are shown in graphs by way of example in
Figures 8 to 11. The abscissa in the graphs of Figures 8 to 11 is the
distance in the thickness direction of the tentative work 24, and the
ordinate is the distance (with a reference distance being 200 mm,
measurement is made in a range of ±40 mm therefrom) between the twodimensional
laser range meter 26 and the tentative work 24 or the
machined chip 25.
[0050]
Figure 8 shows a case where a machined chip 25 is not adhering to
the tentative work 24, Figure 9 shows a case where a machined chip 25 is
adhering to a middle portion of the tentative work 24, Figure 10 shows a
case where a machined chip 25 is adhering to a position of 10 mm from
19
the upper surface of the tentative work 24, and further Figure 11 shows a
case where a machined chip 25 is adhering to a middle portion of the
tentative work 24.
[0051]
Comparing the graph of Figure 8 with the graphs of Figures 9 to 11,
there are clear differences between them, thereby showing that the
presence or absence of adherence of a foreign substance (for example, a
machined chip) to the bevels 8a and 8b can be reliably detected by the
bevel·shape measurement device 6.
[0052]
Next, the situation of manufacturing a UOE steel pipe 30 by the
manufacturing apparatus 1 relating to the present embodiment will be
described.
In the present invention, the shape of the bevels 8a and 8b before
C·pressing by the C·press machine 10 is carried out is measured as
described above by the bevel-shape measurement device 6 on the thick
plate 7 in whose edge parts 7a and 7b the bevels 8a and 8b are formed by
the beveling device 2.
[0053]
Then, the bevel-shape measurement device 6 determines whether
there is a need for modifying the shape of the bevels 8a and 8b of the
thick plate 7 based on the measurement result as described above before
C·pressing by the C·press machine 10 is started.
[0054]
20
When determining that there is no need for modifying the shape of
the bevels 8a and 8b of the thick plate 7, the bevel-shape measurement
device 6 does not output an alarm etc. to the operator 17. In this case,
the thick plate 7 is fed as-is to the steel pipe forming device 4, and is
subjected to C-pressing by the C-press machine 10, U-pressing by the Upress
machine 11, and 0-pressing by the 0-press machine 12 to be
shaped into an open pipe 13. The open pipe 13 is fed to the welding
device 5, and the bevels 8a and 8b are butted together and welded to be
formed into a steel pipe 14; the steel pipe 14 being fed to an expansion
processing device 15 and subjected to expansion processing to be formed
into a UOE steel pipe 30.
[0055]
On one hand, when determining that there is a need for modifying
the shape of the bevels 8a and 8b of the thick plate 7, the bevel-shape
measurement device 6 outputs an alarm etc. to the operator 17. In this
case, the operator 17 temporarily stops the beveling device 2 and adjusts
the setting of the cemented carbide bite of the beveling device 2 such that
appropriate angles (91 to 93) and thicknesses (X1 to X3) are obtained, for
example, based on the angles (91 to 93) and the thicknesses (X1 to X3) of
the bevels 8a and 8b outputted by the bevel-shape measurement device 6.
Then, for all the thick plates which have beveled after the above
described thick plate 7, the modification of the shape of the bevels 8a and
8b is performed by the beveling device 2 including the cemented carbide
bite of which setting has been adjusted.
[0056]
21
Then, the thick plate 7 for which modification of the shape of the
bevels 8a and 8b has been thus performed is fed to the steel pipe forming
device 4 and is subjected to C-pressing by the C·press machine 10, Upressing
by the U ·press machine 11, and O·pressing by the 0-press
machine 12 to be shaped into an open pipe 13. The open pipe 13 is fed to
the welding device 5 so that the bevels 8a and 8b are butted together and
welded to form a steel pipe 14, and further the steel pipe 14 is fed to an
expansion processing device 15 and subjected to expansion processing to
form a UOE steel pipe 30.
[0057]
In this way, according to the present invention, it is determined
whether or not the shape of the bevels 8a and 8b formed in the edge parts
7a and 7b of the thick plate 7 by the beveling device 2 such as an edge
planer is appropriate by using a dedicated bevel-shape measurement
device 6 for measuring the shape of the bevels 8a and 8b of the thick plate
7; and when it is not appropriate, it is possible to quickly output the need
for modifying the shape of the bevels 8a and 8b to the operator 17. As a
result, it becomes possible to manufacture the UOE steel pipe 30 while
preventing an increase in man-hours and a decline of yield caused by
abnormalities of the shape of the bevels 8a and 8b.
[0058]
Moreover, according to the present invention, it becomes possible to
very quickly perform the adjustment of the cutting quantity of the
cemented carbide bite of the beveling device 2 such as an edge planer, and
22
to suppress the occurrence of welding defects which have been occurring
at the start of the manufacturing ofUOE steel pipe so far.
[0059]
Further, according to the present invention, since it is also possible
to detect the presence or absence of a machined chip during beveling
which is thermally stuck to and remains to adhere to the bevels 8a and 8b,
it is possible to significantly suppress a defective holding down (a dent
flaw) of the outer surface of the UOE steel pipe 30 caused by the press
working at the steel pipe forming device 4.
Reference Signs List
[0060]
1 Apparatus for manufacturing UOE steel pipe
2 Beveling device
3 Conveyance system
4 Steel pipe forming device
5 Welding device
6 Bevel-shape measurement device
7 Thick plate
7 a, 7b Edge part
8a, 8b Bevel
9 Conveyor roller
10 C·press machine
11 U ·press machine
12 O·press machine
23
13 Open pipe
14 Steel pipe
15 Expansion processing device
16a, 16b Linear laser beam
17 Operator
18a, 18b Two-dimensional laser range meter
18a-1, 18a-~ 18b-1, 18b-2 Two-dimensional laser range meter
19 Frame
20 Bracket
21 Stepping motor
22 Bracket
23 Warping suppressor
24 Tentative work
25 Machined chip
26 Two-dimensional laser range meter
27 Linear laser beam
30 UOE steel pipe

We claim:
1. A method for manufacturing a UOE steel pipe or tube in which
a steel plate provided with a bevel in an edge part thereof is successively
subjected to C-pressing, U-pressing, and 0-pressing into an open pipe or
tube, and bevels of the open pipe or tube are butted together and welded,
wherein
a shape of the bevel of the steel plate is measured prior to the Cpressing
and determination is made based on the measurement result
whether there is a need for modifying the shape of the bevel of the steel
plate before the C-pressing is started.
2. The method for manufacturing a UOE steel pipe or tube
according to claim 1, wherein
the shape of the bevel is measured by a light-section method that
irradiates the edge part of the steel plate with a linear laser beam which
expands in the thickness direction of the steel plate.
3. The method for manufacturing a UOE steel pipe or tube
according to claim 1 or 2, wherein
a plurality of the linear laser beams are radiated in the conveyance
direction of the steel plate.
4. The method for manufacturing a UOE steel pipe or tube
according to any of claims 1 to 3, wherein
25
after the bevel is formed, the steel plate is conveyed by a conveyor
roller to the C-press machine where the C-pressing is carried out, and the
shape of the bevel is measured in the vicinity of the conveyor roller and at
an exit side of the conveyance direction of the steel plate.
5. An apparatus for manufacturing a UOE steel pipe or tube
comprisinga
beveling device for forming a bevel in an edge part of a steel plate;
a conveyance system for conveying the beveled steel plateJ
a steel pipe or tube forming device including a C-press machine, a
U'press machine, and an 0-press machine, and for shaping the beveled
steel plate into an open pipe or tubeJ and
a welding machine for butting the bevels of the open pipe or tube
and welding the same, wherein
the apparatus further comprises a bevel-shape measurement device
for measuring the shape of the bevel of the steel plate prior to C-pressing
carried out by the C-press machine, between the beveling device and the
C-press machine, and
the bevel-shape measurement device determines whether there is a
need for modiiying the shape of the bevel of the steel plate before the Cpressing
is started based on the measurement result of the shape of the
bevel.