JP6191591B2 - Non-expanded pipe detecting device and detecting method, and welded steel pipe manufacturing equipment and manufacturing method - Google Patents

Description

  The present invention relates to a detection device and a detection method for an unexpanded portion of a welded steel pipe, and a manufacturing equipment and a manufacturing method for the welded steel pipe.

  When manufacturing a large-diameter welded steel pipe used for line pipe piping or structure, pipe expansion is performed to increase the roundness of the steel pipe. Specifically, the pipe expansion head inserted inside the steel pipe pushes and widens the steel pipe, thereby expanding the steel pipe and improving the roundness of the steel pipe. Usually, when expanding a steel pipe, the entire length of the steel pipe is expanded by performing a plurality of expansion processes corresponding to a plurality of expansion areas of the steel pipe divided in the longitudinal direction. At this time, in each tube expansion step, tube expansion is performed in a plurality of passes according to the length of the tube expansion head.

  In Patent Document 1, the pipe center part of the welded steel pipe is first expanded, and then at least one of roundness and straightness of the pipe end not expanded is measured, and each cross section of the pipe end is measured from the measurement result. Has disclosed a tube expansion method for expanding a tube end portion after lubricating the relatively small-diameter opposed inner surface. According to the pipe expansion method described in Patent Document 1, it is possible to improve the roundness and straightness of the welded steel pipe particularly at the pipe end.

JP-A-56-77033

  However, as in the pipe expansion method described in Patent Document 1, when pipe expansion is performed in a plurality of pipe expansion processes with respect to a plurality of pipe expansion areas, each pipe expansion is performed by moving the welded steel pipe relative to a fixed pipe expansion head. The area is expanded. At this time, if an abnormality occurs in the control system of the detector that detects the moving position of the welded steel pipe, an unexpanded pipe portion that has not been pipe-expanded occurs in the steel pipe. Usually, since it is difficult to determine the presence or absence of an unexpanded portion in a state where a welded steel pipe is arranged in a pipe expanding device that performs pipe expansion, the presence or absence of an unexpanded portion is determined after the steel pipe is transported to another facility. At this time, the welded steel pipe determined to have an unexpanded portion is conveyed again to the tube expanding device, and the unexpanded portion is expanded. In this case, it has been a problem that the productivity of the pipe expansion device is lowered.

  Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and can easily detect the unexpanded portion of the welded steel pipe, the detection device and the detection method of the unexpanded portion, and It aims at providing the manufacturing equipment and manufacturing method of a welded steel pipe.

In order to achieve the above object, the non-expanded portion detection device according to one aspect of the present invention is overlapped by two expansion steps in a welded steel pipe region expanded by a plurality of expansion steps using the expansion device. And a determination unit that determines whether or not there is an unexpanded portion of the welded steel pipe based on the expansion pressure of the expansion device when the overlapping region that is expanded is expanded.
In addition, the method for detecting an unexpanded pipe portion according to one aspect of the present invention includes two pipe expanding processes among the areas where the welded steel pipe is expanded when the welded steel pipe is expanded by a plurality of pipe expanding processes using the pipe expanding device. The presence or absence of an unexpanded portion of the welded steel pipe is determined based on a pipe expansion pressure when an overlapping region that is expanded and expanded is expanded.
In addition, a welded steel pipe manufacturing facility according to an aspect of the present invention includes the above-described unexpanded pipe detecting device and a pipe expanding device that expands the welded steel pipe in a plurality of pipe expanding processes.
Moreover, the manufacturing method of the welded steel pipe which concerns on 1 aspect of this invention determines the presence or absence of the unexpanded part of a welded steel pipe using the detection method of the said unexpanded part.

  According to the non-expanded pipe detecting device and detection method, and the welded steel pipe manufacturing facility and manufacturing method according to the present invention, the non-expanded pipe welded steel pipe can be easily detected.

It is a block diagram which shows the manufacturing equipment of the welded steel pipe which concerns on one Embodiment of this invention. It is a partial cross section figure which shows a pipe expansion part. It is explanatory drawing which shows the state at the time of a pipe expansion start. It is explanatory drawing which shows the state at the time of pipe expansion. It is explanatory drawing which shows the pipe expansion area | region of a welded steel pipe. It is a graph which shows the pipe expansion pressure in a 1st pipe expansion process. It is a graph which shows the pipe expansion pressure in a 2nd pipe expansion process.

DESCRIPTION OF EMBODIMENTS Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.
<Configuration of tube expansion device>
First, with reference to FIG. 1 and FIG. 2, the structure of the manufacturing equipment 1 of the welded steel pipe which concerns on one Embodiment of this invention is demonstrated. A welded steel pipe manufacturing facility 1 according to an embodiment of the present invention includes a pipe expansion device 2 and a detection device 3 as shown in FIG. The steel pipe S, which is a welded steel pipe expanded in the manufacturing facility 1, is a large-diameter welded steel pipe having an outer diameter of 400 mm or more formed and welded by the UOE method or the breath bend method. In the manufacturing facility 1, the roundness of the steel pipe S is improved by expanding the steel pipe S formed and welded in another manufacturing facility (not shown).

The pipe expansion device 2 includes a first pipe expansion portion 2a, a second pipe expansion portion 2b, and a control portion 2c, and is a processing device that expands the steel pipe S.
The 1st pipe expansion part 2a has the axial part 21a, the pipe expansion head 22a, the drive part 23a, the gripper trolley 24a, and the pipe receiving rolls 251a-255a. As shown in FIG. 2, the shaft portion 21a includes a horn 211a and a draw bar 212a. The tube expansion head 22a has a cone 221a and a die 222a.

  The horn 211a of the shaft portion 21a is a substantially cylindrical member, and one end is fixed to the housing of the drive unit 23a and the other end is connected to the die 222a. The draw bar 212a of the shaft portion 21a is a columnar member, and one end side is connected to driving means such as a hydraulic cylinder provided inside the driving portion 23a, and the other end side is fixed to the cone 221a. The cone 221a of the tube expansion head 22a is a member having a truncated cone shape, and is fixed to the draw bar 212a with the draw bar 212a inserted therein. The die 222a of the tube expansion head 22a is a substantially cylindrical member, and a taper corresponding to the inclination of the outer peripheral surface of the cone 221a is formed inside, and the taper is further tapered on the outer peripheral surface on one end side so that the outer diameter becomes smaller. It is formed. In other words, in the tube expanding head 22a, the cone 221a is provided in a wedge shape with respect to the die 222a. The die 222a has a length of about 400 to 1,100 mm in the longitudinal direction, and is composed of a plurality of members that are divided into equal lengths in a substantially cylindrical circumferential direction. The drive unit 23a is a device having a drive manual such as a hydraulic cylinder inside.

The drive unit 23a has a drive unit such as a hydraulic cylinder inside, and moves the draw bar 212a connected to the drive unit in parallel to the longitudinal direction of the draw bar 212a based on an instruction from the control unit 2c. Further, when the drive unit 23a moves the draw bar 212a, the drive unit 23a transmits the actual hydraulic pressure of the cylinder to the determination unit 31 as the pipe expansion pressure.
The gripper carriage 24a has a holding portion 241a at the tip. The holding part 241a holds the steel pipe S by sandwiching the ends of the steel pipes S provided on the pipe receiving rolls 251a to 255a. The gripper carriage 24a moves the steel pipe S by moving parallel to the longitudinal direction of the shaft part 21a in a state where the holding part 241a holds the end of the steel pipe S. Further, the gripper carriage 24a holds and moves the steel pipe S based on an instruction from the control unit 2c.

The pipe receiving rolls 251a to 255a are provided side by side in the longitudinal direction of the shaft portion 21a so as to overlap the central axis in the longitudinal direction of the shaft portion 21a. The pipe receiving rolls 251a to 255a support the steel pipe S from below and assist the movement in the direction parallel to the longitudinal direction of the shaft portion 21a of the steel pipe S.
The first pipe expanding section 2a expands the die 222a outward in the circumferential direction by moving the draw bar 212a by the driving section 23a in a state where the pipe expanding head 22a is disposed inside the steel pipe S. By this operation, the steel pipe S is expanded by the die 222a pushing the steel pipe S from the inside. Moreover, the 1st pipe expansion part 2a is the area | region of the one end side of the steel pipe S by arrange | positioning the drive part 23a on the one end side of the steel pipe S provided in the pipe receiving rolls 251a-255a, and the gripper carriage 24a on the other end side, respectively. To expand. Details of the operation at the time of tube expansion will be described later.

The 2nd pipe expansion part 2b has the same structure as the 1st pipe expansion part 2a. That is, the 2nd pipe expansion part 2b has the axial part 21b, the pipe expansion head 22b, the drive part 23b, the gripper carriage 24b, and the pipe receiving rolls 251b-255b. In addition, the 2nd pipe expansion part 2b differs from the 1st pipe expansion part 2a, and the drive part 23b is arrange | positioned at the other end side of the steel pipe S provided in the pipe receiving rolls 251b-255b, respectively, and the gripper carriage 24b is arrange | positioned at one end side. For this reason, the 2nd pipe expansion part 2b expands the area | region of the other end side of the steel pipe S which becomes an opposite side to the area | region expanded by the 1st pipe expansion part 2a.
The control part 2c performs the pipe expansion of the steel pipe S by controlling the pipe expansion operation of the first pipe expansion part 2a and the second pipe expansion part 2b. Details of the tube expansion operation of the tube expansion device 2 will be described later.

The detection device 3 includes a determination unit 31, a display unit 32, and an alarm unit 33.
The determination part 31 acquires and memorize | stores a pipe expansion pressure from the drive parts 23a and 23b, and determines the presence or absence of the unexpanded part of the steel pipe S based on the acquired pipe expansion pressure. A method for determining the unexpanded portion will be described later.
The display unit 32 is a display device such as a monitor, and displays a determination result on the presence or absence of an unexpanded portion by the determination unit 31. The alarm unit 33 is an acoustic device such as a speaker, and when the determination unit 31 determines that there is an unexpanded part, the alarm unit 33 notifies the determination result as an abnormality by voice or the like.

<Tube expansion operation>
Next, the tube expansion operation of the tube expansion device 2 will be described with reference to FIGS. In the present embodiment, when the steel pipe S is expanded using the pipe expansion device 2, the entire length of the steel pipe S is expanded by performing expansion in two expansion processes, the first expansion process and the second expansion process. At this time, in the first pipe expansion process, the first pipe expansion area on one end side of the steel pipe S is expanded using the first pipe expansion section 2a, and in the second pipe expansion process, the other end of the steel pipe S is used using the second pipe expansion section 2b. The second expanded area on the side is expanded.

[First tube expansion process]
First, a 1st pipe expansion process is demonstrated. First, in a 1st pipe expansion process, as shown to Fig.3 (a), the steel pipe S is arrange | positioned on the pipe receiving rolls 251a-253a of the 1st pipe expansion part 2a. As the steel pipe S, a pipe that is processed into a substantially pipe shape and welded at another seam is used.
Next, the holding portion 241 a of the gripper carriage 24 a sandwiches the end portion on the B side that is the other end side of the steel pipe S. Further, the control unit 2c moves the gripper carriage 24a to the tube expansion start position. At this time, the gripper carriage 24a moves in the direction parallel to the longitudinal direction of the steel pipe S, thereby moving the steel pipe S in the direction parallel to the longitudinal direction of the shaft portion 21a. The pipe expansion start position is a position shown in FIG. 3B, and is a position where the die 222 a of the pipe expansion head 22 a is partially inserted into the end portion on the A side that is one end side of the steel pipe S.

Furthermore, the control part 2c expands the steel pipe S by driving the drive part 23a. At this time, the drive part 23a moves the draw bar 212a to the drive part 23a side by the drive means provided inside. Further, as shown in FIG. 4, with the movement of the draw bar 212a, the cone 221a fixed to the tip of the draw bar 212a moves toward the drive unit 23a. Here, since the cone 221a is provided in a wedge shape with respect to the die 222a, when the cone 221a moves to the drive unit 23a side, the die 222a spreads outward in the circumferential direction and pushes the steel pipe S from the inside. spread. The tube expanding operation, as shown in FIG. 5 (a), the tube expanding region d ₁ is a region of Saitan portion A side of the steel pipe S is the tube expansion. In addition, in FIG. 4, although the mode of the pipe expansion in the area | region inside the edge part of the steel pipe S is shown, also in the edge part of the steel pipe S shown to the pipe expansion area | region d1, the _1st pipe expansion part 2a operate | moves similarly. The expansion is performed in the same way.

Thereafter, the controller 2c drives the drive unit 23a to move the draw bar 212a to the side opposite to the drive unit 23a, and returns the tube expansion head 22a to the state before the tube expansion.
Next, the control unit 2c moves the gripper carriage 24a to the drive unit 23a side by a predetermined distance. The predetermined distance is a distance determined by the length of the die 222a, the detection accuracy of the moving distance of the gripper carriage 24a, and the like, and is a distance at which an unexpanded portion is not generated by tube expansion using the tube expansion head 22a that is continuously performed thereafter. It is determined. In the example shown in FIG. 5 (a), the predetermined distance is the same distance as the longitudinal length of the tube expanding region d _2. The longitudinal length of the tube expanding region d ₂ is set to be shorter than the longitudinal length of the die 222a. Incidentally, longitudinal length of the tube expanding region _d 2 _{to d 15} are all the same length.
Furthermore, the control part 2c expands the steel pipe S by driving the drive part 23a. Tube expanding operation of the steel tube S is performed in the same manner as when the tube expansion of the expanded area d _1, the tube expanding region d ₂ is the tube expansion by this operation.

Thereafter, the operation of returning the pipe expansion head 22a to the state before the pipe expansion, the operation of moving the gripper carriage 24a toward the drive unit 23a side by a predetermined distance, and the operation of expanding the steel pipe S are repeatedly performed. The pipe expansion areas d _{3 to} d ₁₅ are expanded in order. Hereinafter, the above-described one-time tube expansion operation is also referred to as a tube expansion path. That is, in the first pipe expansion process, the pipe expansion areas d _{1 to} d ₁₅ that are the _first pipe expansion areas are all expanded by performing the pipe expansion pass 15 times.
After tube expansion of the expanded region d ₁₅ is completed, expanded pipe head 22a is returned to the state before the tube expansion. Next, the gripper carriage 24a moves until the steel pipe S shown in FIG. 3A is first provided in the pipe receiving rolls 251a to 253a. Further, the holding of the steel pipe S by the holding portion 241a is released. The first tube expansion step is completed through the above steps.

[Second pipe expansion process]
Next, the second tube expansion process will be described. In the second expanding process, using a second expanded portion 2b, by the same processing as that in the first expanding process is performed, the tube expanding region d ₁₆ to d ₃₀ is a second tube expanding region in FIG. 5 (b) expanded pipe Is done.
Specifically, first, after the first pipe expansion region of the steel pipe S is expanded in the first pipe expansion process, the steel pipe S is disposed on the pipe receiving rolls 251b to 253b of the second pipe expansion portion 2b. At this time, the steel pipe S is arrange | positioned so that the edge part by the side of B of the steel pipe S which is not expanded is located in the drive part 23b side.

Next, the holding portion 241 b of the gripper carriage 24 b sandwiches the end portion on the A side of the steel pipe S. Further, similarly to the first expanding process, the gripper carriage 24b is moved to tube expansion starting position, tube expanding region d ₁₆ shown in FIG. 5 (b) is the tube expansion.
Thereafter, as in the first pipe expanding step, an operation of returning the pipe expanding head 22b to the state before the pipe expanding, an operation of moving the gripper carriage 24b to the drive unit 23b side by a predetermined distance, and an operation of expanding the steel pipe S are performed. by repeatedly performed, the tube expanding region _d 17 _{to d 30} are sequentially pipe expansion. In the second tube expansion step, the second tube expansion region is expanded by performing tube expansion passes a total of 15 times.
After tube expansion of the expanded region d ₃₀ is completed, expanded pipe head 22b is returned to the state before tube expansion, the second expanding process is completed.

In the first and second tube expansion steps, the first and second tube expansion regions are expanded. At this time, as shown in FIG. 5 (c), overlapped region d _S occurs that tube expanding region d ₃₀ of the expanded region d ₁₅ and the second tube expanding region of the first tube expanding regions overlap. In the present embodiment, the entire length of the steel pipe S is expanded by overlapping the expanded area d ₁₅ and the expanded area d ₃₀ so that the overlapping area d _S is generated.

<Detection method of unexpanded tube>
When the position of the steel pipe S is adjusted in each pipe expansion path in the first and second pipe expansion processes, the control unit 2c detects the position of the steel pipe S from the moving distance of the gripper carriages 24a and 24b. The movement distances of the gripper carriages 24a and 24b are calculated based on detection results of sensors such as a rotation detector and a reference sensor connected to a rotation drive unit such as an electric motor provided in the gripper carriages 24a and 24b. However, if an abnormality occurs in the control system of these gripper carriages 24a and 24b, an error occurs in the movement results of the gripper carriages 24a and 24b. At this time, when the detected moving distance becomes longer than the actual result, the actual expanded area length becomes shorter than the target expanded area length, and thus an unexpanded portion where no expansion is performed occurs. In particular, in the overlapping region d _S of the steel pipe S that is greatly affected by the error, an unexpanded portion is likely to occur. In the present embodiment, the presence or absence of such an unexpanded portion is determined and detected by the following method.

With reference to FIG. 6 and FIG. 7, the detection method of the unexpanded pipe part which concerns on this embodiment is demonstrated. In this embodiment, the determination part 31 acquires and memorize | stores the pipe expansion pressure at the time of pipe expansion in a 1st and 2nd pipe expansion process from drive part 23a, 23b. At this time, for example, the tube expansion pressure is continuously acquired at regular intervals after the first and second tube expansion steps are started.
6 and 7 are time charts showing the tube expansion pressure in the first and second tube expansion steps, with the horizontal axis indicating time and the vertical axis indicating tube expansion pressure. In FIG. 6 and FIG. 7, 15 peaks are detected in accordance with 15 expansion paths in the first and second expansion processes. Of these, the first peak after the start of the first and second tube expansion steps has a lower tube expansion pressure than the second to 15th peaks in FIG. 6 and the second to 14th peaks in FIG. 7. This is because the first tube expansion pass in the first and second tube expansion steps is tube expansion at the position where the dies 222a and 222b are partially inserted into the steel pipe S, and the length of the tube expansion region is longer than other tube expansion paths. This is caused by shortness. Further, the fifteenth peak indicated by the broken line region in FIG. 7 has a lower tube expansion pressure than the second to fifteenth peaks in FIG. 6 and the second to fourteenth peaks in FIG. This is because the fifteenth tube expansion pass, which is the final tube expansion pass of the second tube expansion step, expands the tube expansion region including the overlapping region that has already been expanded by the first tube expansion step. This occurs because the length of the area to be processed is shortened. Therefore, when the expansion pressure at the peak of the final expansion path in the second expansion process is equal to the expansion pressure at the other peak, it indicates that the expansion of the same length as the other expansion paths has been performed, It shows that there is a possibility that an unexpanded portion has occurred in the vicinity of the overlapping portion region in the central portion of the steel pipe S.

  After acquiring the pipe expansion pressure, the determination unit 31 determines whether or not there is an unexpanded part of the steel pipe S based on the pipe expansion pressure when the overlapping region expanded in the first and second pipe expansion processes is expanded. judge. At this time, the determination unit 31 extracts peak values from the acquired tube expansion pressure. Next, the determination unit 31 extracts the expansion pressure in the final expansion path in the second expansion process from the detected peak value, and determines whether or not there is an unexpanded part depending on whether the expansion pressure in the final expansion path is greater than the reference pressure. To do. Here, the reference pressure is 80% of the average value of the tube expansion pressure at other peak values excluding the first and fifteenth peak values in the second tube expansion step, and is calculated by the determination unit 31 in advance. The determination unit 31 determines that there is an unexpanded part when the expanded pressure in the final expanded path is greater than the reference pressure, and determines that there is no unexpanded part when the pressure is equal to or lower than the reference pressure.

After determining the presence or absence of the unexpanded portion, the display unit 32 displays the determination result regarding the presence or absence of the unexpanded portion by the determination unit 31. Further, when the determination unit 31 determines that there is an unexpanded part, the operator is notified of the abnormality by voice or the like.
In addition, when there exists an unexpanded part, an operator operates the 2nd expanded part 2b so that the area | region of the A end side including an unexpanded part and a 2nd expanded area may be expanded. In this case, in a state in which the second tube expansion process is completed, because the pipe expanding head 22b is in a position superimposed on the tube expanding region d _30, operation of the gripper carriage 24b is moved to a predetermined distance driving unit 23b side, and the steel pipe S The unexpanded portion can be eliminated simply by performing the operation of expanding the tube.

<Modification>
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

For example, the number of pipe expansion passes and the length of the pipe expansion area in the first and second pipe expansion processes are appropriately set according to various manufacturing conditions such as the length of the pipe expansion heads 22a and 22b and the length of the steel pipe S.
Moreover, in the said embodiment, although the steel pipe S was expanded by two pipe expansion processes of the 1st and 2nd pipe expansion processes, this invention is not limited to this example. For example, as described in Patent Document 1, the steel pipe S may be expanded by three or more expansion processes. At this time, the detection of the unexpanded portion is performed on each of the plurality of overlapping regions using the above detection method.

  Moreover, in the said embodiment, when it determines with having an unexpanded part, the area | region of the A end side which follows a 2nd expanded area including an unexpanded part by an operator operating the 2nd expanded part 2b. However, the present invention is not limited to such an example. For example, when it is determined that there is an unexpanded part, the determination unit 31 may output an instruction to the control unit 2c so as to perform an additional tube expansion operation. Upon receiving the instruction for the additional tube expansion operation, the control unit 2c automatically controls the drive unit 23b and the gripper carriage 24b so that the region on the A end side is further expanded from the region expanded in the final tube expansion path of the second tube expansion process. Expanded. Further, when such an additional tube expansion operation is performed, the detection device 3 may further determine the presence or absence of an unexpanded portion from the tube expansion pressure during the additional tube expansion.

  Furthermore, in the above-described embodiment, the reference pressure is 80% of the average value of the expansion pressure at the first and fifteenth peak values in the second expansion process, that is, the other peak values excluding the peak values in the first and last expansion paths. However, the present invention is not limited to this example. For example, the reference pressure may be a value other than 80% of the average value of the expanded pressure at other peak values, depending on the detection accuracy of the moving distance of the steel pipe S in the second expanded portion 2b. In addition, it can be applied to most facilities by setting the reference pressure to 80% or 90% of the average value of the expansion pressure at other peak values. Furthermore, the reference pressure may be a value calculated in advance according to the material, size, etc. of the steel pipe S, or a value determined from the actual expansion of other steel pipes.

  Moreover, in the said embodiment, although the determination part 31 determined the presence or absence of the unexpanded part using the pipe expansion pressure in a 2nd pipe expansion process, this invention is not limited to this example. For example, the determination unit 31 determines the presence / absence of an unexpanded portion using the above-described expanded pressure, and simultaneously acquires the actual travel distance from the gripper carriages 24a and 24b, and determines the presence / absence of the unexpanded portion from the acquired travel distance. You may judge. Thereby, the presence or absence of the unexpanded portion can be detected in a double manner by using two different indexes of the tube expansion pressure and the movement distances of the gripper carriages 24a and 24b.

  In the above description, the first pipe expansion process is performed in the first pipe expansion section, and the second pipe expansion process is performed in the second pipe expansion section. However, the first pipe expansion process and the second pipe expansion process are common 1 It is also possible to carry out with two expanded parts. For example, a steel pipe rotating facility that rotates the longitudinal direction of the steel pipe by 180 degrees is provided, the longitudinal direction of the steel pipe that has completed the first pipe expanding step is rotated by 180 degrees using the steel pipe rotating device, and the first pipe expanding What is necessary is just to implement a 2nd pipe expansion process by the same pipe expansion part used by the process.

<Effect of embodiment>
(1) The unexpanded tube detection device according to the embodiment of the present invention is expanded by two tube expansion steps in the region of the steel pipe S expanded by a plurality of tube expansion steps using the tube expansion device 2. when overlapping area d _S is the tube expansion, based on the tube expansion pressure of expanding apparatus 2 includes a determining unit 31 whether the non-expanded portion of the steel pipe S.

  According to the above configuration, since the determination unit 31 determines the presence / absence of an unexpanded portion from the expanded pressure of the expanded device 2, the unexpanded portion can be detected immediately after expanded by the expanded device 2. For this reason, an unexpanded pipe part can be detected simply and in a short time. Moreover, after expanding the steel pipe S with the pipe expansion device 2, compared with the case where determination of an unexpanded part is performed in another equipment, conveyance to the pipe expansion apparatus 2 from another equipment, or addition with the pipe expansion apparatus 2 As a result, it is possible to reduce the time and work load required for the expansion of the pipe, and also to prevent other materials from being hindered, so that productivity can be improved.

  Here, when an unexpanded portion is generated due to a system abnormality such as a rotation detector, the operator can easily detect the abnormality at an early stage. However, when an unexpanded portion occurs due to a malfunction of the reference sensor or the like, it is difficult for an operator to find an abnormality, so the unexpanded portion must be discovered in a later inspection process or the like. In such a case, productivity decreases for the various reasons described above. However, according to the above configuration, in any case where an unexpanded portion occurs due to a system abnormality such as a rotation detector, or an unexpanded portion occurs due to a malfunction or the like of the reference sensor, An unexpanded portion can be detected immediately after the expansion.

(2) determination unit 31 determines that at tube expansion step to be performed later ones of two expanding process, non-expanded portion when the tube expanding pressure is greater than the reference pressure when the overlapping area d _S is the tube expansion there .
(3) determination unit 31, the tube expansion pressure when the tube expanding regions other than the overlap area d _S of the area to be expanded tube of steel S, and calculates the reference pressure. According to the above configuration, since the unexpanded portion is determined using the expanded pressure of the same steel pipe S as the reference pressure, the unexpanded portion can be detected with high accuracy.

(4) The tube expansion device 2 includes a first tube expansion step in which one end side in the longitudinal direction of the steel pipe S including the overlap region d _S is expanded by a plurality of tube expansion passes, and an overlap region d by a plurality of tube expansion passes after the first tube expansion step. _The steel pipe S is expanded by two expansion processes of the second process of expanding the other end side of the steel pipe S including S, and the determination unit 31 expands the expansion pressure when the overlapping region d _S is expanded in the second expansion process. Based on the above, the presence or absence of an unexpanded portion is determined. According to the above configuration, even in a general expanding process of tube expansion of the steel tube S is carried out in two expanding process, it is possible to easily detect the non-expanded pipe portion which occurs in an overlapping region d _S.

(5) When it is determined that there is an unexpanded part, the alarm part 33 for notifying abnormality is further provided. According to the above configuration, the operator can be quickly notified that the unexpanded portion has been detected as an abnormality, so that the worker can quickly perform a treatment on the unexpanded portion.
(6) When it is determined that there is an unexpanded portion, the determination unit 31 instructs the tube expansion device 2 to further perform a tube expansion operation. According to the above configuration, even when an unexpanded pipe portion is generated, a treatment for the unexpanded pipe portion can be performed automatically, so that the work load on the operator can be reduced.

(7) The method for detecting an unexpanded portion according to the embodiment of the present invention is to expand two of the regions where the steel pipe S is expanded when the steel pipe S is expanded by a plurality of expansion processes using the tube expansion device 2. based on the expanded pipe pressure when the overlapping region d _S is the tube expansion is expanded pipe overlap by step, and determines the presence or absence of non-expanded portion of the steel pipe S.
(8) A steel pipe manufacturing facility according to an embodiment of the present invention expands a steel pipe in a plurality of pipe expanding steps with the non-expanded portion detection device 3 according to any one of (1) to (6) above. A tube expansion device 2.
(9) The manufacturing method of the steel pipe which concerns on embodiment of this invention determines the presence or absence of the unexpanded part of a steel pipe using the detection method of the unexpanded part as described in said (7).
According to the configurations of (7) to (9) above, the same effect as in (1) can be obtained.

1: tube expansion device 2: tube expansion device 21: shaft portion 211: horn 212: draw bar 22: tube expansion head 221: cone 222: die 23: drive unit 3: gripper carriage 31: holding unit 4a to 4e: pipe receiving roll 5: determination Part 6: Display part 7: Alarm part 8: Control part

Claims (8)

Based on the tube expansion pressure of the tube expansion device when the overlapping region expanded by two of the tube expansion steps is expanded among the regions of the steel pipe expanded by a plurality of tube expansion steps using the tube expansion device, A determination unit for determining the presence or absence of an unexpanded portion of the steel pipe ;
The determination unit determines that the unexpanded portion is present when the tube expansion pressure when the overlapping region is expanded is larger than a reference pressure in the tube expansion step performed later of the two tube expansion steps. An unexpanded tube detecting device. The determination unit, non-expanded portion of claim 1, characterized in that from the tube expansion pressure when the tube expanding region other than the overlap area of the region to be expanded tube of the steel pipe, and calculates the reference pressure Detection device. The tube expansion device includes a first tube expansion step for expanding one end side in the longitudinal direction of the steel pipe including the overlap region by a plurality of tube expansion passes, and the overlap region by a plurality of tube expansion passes after the first tube expansion step. Expanding the steel pipe by the two expansion processes of the second expansion process of expanding the other end of the steel pipe;
The determination unit, in the second expanding process, based on the expanded pipe pressure when the overlapping area is expanded tube, the according to claim 1 or 2, characterized in that to determine the presence or absence of a non-expanded pipe portion Unexpanded tube detection device. The apparatus for detecting an unexpanded part according to any one of claims 1 to 3 , further comprising an alarm part for notifying abnormality when it is determined that the unexpanded part is present. The non-expansion unit according to any one of claims 1 to 4 , wherein the determination unit instructs the tube expansion device to further perform a tube expansion operation when it is determined that the unexpanded tube unit is present. A device for detecting the expanded portion. When expanding a steel pipe by multiple pipe expansion processes using a pipe expansion device,
Based on the tube expansion pressure when the overlapping region expanded by two of the tube expansion steps is expanded in the region where the steel tube is expanded, the presence or absence of an unexpanded portion of the steel tube is determined ,
When the presence or absence of the unexpanded portion is determined, the unexpanded portion is expanded when the expanded tube pressure is larger than a reference pressure in the expanded tube step performed later in the expanded tube region. A method for detecting an unexpanded portion, wherein it is determined that the expanded portion is present . The detection device for an unexpanded portion according to any one of claims 1 to 5 ,
A steel pipe manufacturing facility comprising a pipe expanding device for expanding a steel pipe in a plurality of pipe expanding processes. A method for manufacturing a steel pipe, wherein the presence or absence of an unexpanded portion of a steel pipe is determined using the method for detecting an unexpanded portion according to claim 6 .

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