JPH09262794A - Method and device for removing film for covering steel pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate the need for peeling work at a refining process, obviate the need for a device for peeling use only, and reduce the cost by a method wherein when a part of a film with which the whole of a covering steel pipe is covered is cut and removed, partial cutting of the film and peel of the cut film is effected on a cover processing line. SOLUTION: In a cover processing line related to a covering steel pipe, a circular blade 4 and a longitudinal blade 7 are arranged at a cutter head 8 at a specified distance so as to surround the periphery of a covering steel pipe so that cutting of a part of a film 6 with which the whole of a pipe is covered and peeling thereof are simultaneously effected. Namely, the one or more circular blades 4 are arranged with a specified distance therebetween in the longitudinal direction of the covering steel pipe in such a manner that a surface is extended vertically to a pipe axis and a vertical blade 7 to cut a longitudinal direction has a blade surface arranged in parallel to a pipe axis. The film 6 for a removing part is cut in an oblong shape. A plurality of sets of the circular blade 4 and the vertical blade 7 are supported at the periphery of the covering steel pipe by the cutter head 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a coated steel pipe, and more particularly to a technique capable of temporarily cutting and stripping a coating covering the entire pipe in a coating processing line.

[0002]

2. Description of the Related Art In recent years, so-called coated steel pipes, in which the outer peripheral surface of a steel pipe is coated with a plastic resin, have been used for communication cable protection pipes, gas supply pipes, etc. from the viewpoint of their excellent corrosion resistance and economical efficiency. became. Therefore, in the manufacturing process of these coated steel pipes, it is necessary to remove a part of the coating depending on the application before shipping. For example, the coating on the pipe end is cut and removed by an appropriate length so as to be convenient for piping work.

Now, in the coating process line for coating the steel pipe (base pipe) 1, as is apparent from FIG. 2, an aluminum connector called core 2 is commonly used in the pipe end where adjacent steel pipes abut. Then, the outer peripheral surface of that portion is wound with a tape 3 to be connected and integrated, and then the covering process is continuously performed. Then, the integrated product that has been covered is provided on the downstream side of the same line in FIGS. 3 (a) and 3 (b).
The coating 6 is run to the position of the coating cutting machine 5 having the circumferential blade 4 as shown in FIG. The cutting point at that time varies depending on the length of the removed portion, as shown in FIG. 3 (b), but it is common to set the circumferential blade 4 within a range of 100 to 200 mm from the pipe end. is there. After that, the coating 6 on the pipe end, which is circumferentially cut by the circumferential blade 4, is peeled and removed manually by a post-conditioning equipment, and further, the core 2 is removed as a final work, and a large number of pieces are removed. Coated steel pipes are produced at the same time.

By the way, Japanese Patent Publication No. 56-4397 discloses a "pipe end adjusting device for coated steel pipe" capable of cutting the coating film 6 at high speed and with high efficiency and for a wide variety of steel pipes 1.
Suggested. It states that "two pedestals that move horizontally on a base that can move up and down are arranged as a set, and a bearing and a rotary shaft are rotatably fitted and inserted into each pedestal, and one end side of this rotary shaft is an actuator. And a circular machining head is arranged on the other end side, and one machining head is fixedly provided with an opening / closing device (round blade raising / lowering) connected to the fluid pressure drive source. A rotary blade is rotatably attached to the machine part, and an opening / closing device (elevating the holder) connected to the fluid pressure drive source is fixedly installed on the other machining head, and the holder is connected to the moving part of the opening / closing device. The vertical blades are connected to the heating device by engaging with the elastic body provided and using the shaft attachment portion as a fulcrum. "
However, this device does not allow cutting and stripping of the removed portion at the same time, and (1) it is installed not on the coating processing line but on the finishing equipment in the post process,
(2) It takes time to remove the cut coating, (3) a separate peeling machine is required to remove the cut coating, and two or more pipes are required at both pipe ends. (4) Pipe There were drawbacks in terms of equipment cost and work content, such as making it difficult to work on parts other than the end.

[0005]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention provides a method and an apparatus for removing a coating film from a coated steel pipe, which can partially cut and remove the coating film on a coating treatment line at one time. Has an aim.

[0006]

Means for Solving the Problems The inventor has diligently studied in order to achieve the above object, and has two types of cutting blades of a coated steel pipe, a circumferential direction and a longitudinal direction, and the longitudinal cutting blade also has a peeling action. The present invention has been completed with an eye on making it possible. That is, the present invention, cutting a part of the coating covering the entire coated steel pipe,
In the removal, the coating is partially removed and the cut coating is peeled off on a coating treatment line. The present invention is also a method for removing a coating film from a coated steel pipe, characterized in that the above-mentioned cutting is performed in the circumferential direction and the axial direction of the pipe, and the stripping is performed by the cutting blade used for the axial cutting. Further, the present invention provides at least one circumferential cutting blade that circumferentially cuts a part of the coating film that covers the coated steel pipe, at least one vertical cutting blade that cuts in the axial direction of the pipe, and the circumferential cutting blade. And a rotary drum-shaped cutter head that holds a vertical cutting blade and rotates around the pipe axis of the coated steel pipe to cause the vertical cutting blade to peel off the coating, and the cutter head is placed and coated. A coat removing apparatus for a coated steel pipe, comprising: a carriage movable in the axial direction of the steel pipe. In addition, the present invention comprises an electric heater for heating the circumferential cutting blade and / or the vertical cutting blade, or a clamp for gripping the coated steel pipe is provided on the carriage, to remove the coating film from the coated steel pipe. It is also a device.

According to the present invention, the partial coating of the coated steel pipe can be cut and stripped at the same time on the coating processing line, and the post-process conventionally performed, that is, the stripping work by manpower in the conditioning equipment is performed. No longer needed. Further, since no special stripping device is required, increase in equipment cost can be suppressed. Moreover, the coated steel pipe is gripped by the clamp locked to the truck to synchronize the movement of the truck and the movement of the steel pipe, and the work can be smoothly performed even while the steel pipe is traveling. Further, the cutting blade is heated by an electric heater so that cutting can be performed easily and quickly.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. First, FIG. 1 is a perspective view showing the concept of the present invention, and FIG. 12 is a sectional view showing the entire device according to the present invention. Although the rotary drum-shaped cutter head 8 supporting the cutting blade is omitted in FIG. 1, the circumferential cutting blade (usually a disk cutter) 4 is fixed in the longitudinal direction of the coated steel pipe 9. At least one sheet is arranged at intervals (adjustable) so that the surface is perpendicular to the tube axis, and the longitudinal direction is set between these circumferential cutting blades 4 (hereinafter referred to as circumferential blades). A vertical cutting blade 7 (hereinafter referred to as a vertical blade) for cutting is provided with a blade surface parallel to the tube axis. As a result, the coating on the removed portion is cut into a rectangular shape. Although not clear in FIG. 1, a plurality of sets of these circumferential blades 4 and vertical blades 7 are arranged around the coated steel pipe 9 while being supported by the cutter head 8 (shown by dotted lines). The vertical blades 7 at different positions are temporarily shown with an electric heater 11).

The vertical blade 7 is used to remove the cut coating 6. That is, by rotating the cutter head (not shown) 8 around the tube axis, the coating cut by the vertical blade 7 is lifted and peeled off (see FIG. 11). Further, since the cutter head 8 is mounted on the carriage 10 that moves along the pipe axis, even if the coated steel pipe 9 is traveling on the coating treatment line, it is possible to synchronize the truck speed with the traveling speed. So, you can cut and peel off smoothly.

FIG. 4 shows a state in which the circumferential blade 4 and the vertical blade 7 are arranged on the rotary drum-shaped cutter head 8 omitted in FIG. There, the circumferential blade 4 and the vertical blade 7 are arranged at regular intervals so as to surround the circumference of the coated steel pipe 9. Further, the circumferential blade 4 and the vertical blade 7 are cut (roll down) into the coating film 6.
Are configured so that each can be performed by an air cylinder (compression cylinder) 12, and the arrangement position of the circumferential blade 4 in the tube axis direction can be adjusted according to the change in the length of the peeled portion. ing.

5 to 10 show details of the mounting portion of each cutting blade to the cutter head 8. 5 to 7 show details of the mounting of the circumferential blade 4 at the position A in FIG.
Is rotatably supported by a shaft 13 and a bearing 14, and a shaft box 15 can be moved in the pipe axis direction by rotating a screw shaft 16. The drive belt 17 and the rotation knob 18 are shown. The pressure reducing cylinder 12 of the circumferential blade 4 is fixed to a metal fitting 19 fixed to the cutter header 8 with a bolt, and the pressure reducing cylinder 12, the circumferential blade 4 and a sliding frame 20 to which the moving device thereof is attached. Are connected by screws and are slidably supported.

On the other hand, the reduction device for the vertical blade 7 is shown in FIGS.
Will be revealed in. That is, the vertical blade 7 at the position of B in FIG. 4 is fixed to the sliding frame 20 with bolts, and the sliding frame 20 and the pressing cylinder 12 are screwed with the screw 2
They are connected by 2 and are slidably supported by the cutter head 8. In addition, the reduction cylinder 12 of the vertical blade 7 is
It is fixed to the metal fitting 23 fixed to the cutter head 8 with a bolt. Further, when the width of the peeling portion changes and the position of the circumferential blade 4 changes, the vertical blade 7 is changed to a width corresponding to the peeling work.

Next, a method of operating the film removing apparatus according to the present invention will be described. First, when the coated steel pipe 9 for which the coating operation has been completed in the coating processing line 25 is still traveling in the line 25, the core position is detected by a detection device (not shown), and the coating removal device according to the present invention is detected. Are to be synchronously moved to that position (fixed by the clamp 21 shown in FIG. 12). Then, in the synchronized state, the circumferential blade 4 is actuated to start cutting the pipe end position, and after the circumferential cutting progresses to some extent (the circumferential cutting is equal to or more than the phase angle difference between the circumferential blade and the vertical blade). (Advanced state) Start cutting with the vertical blade 7 in the longitudinal direction. As a result, as the cutter head 8 rotates in the state as shown in FIG. 11, the cut portions can be peeled off successively by a predetermined amount.

Since the set of the circumferential blade 4 and the vertical blade 7 is installed in three places in the circumferential direction in this embodiment, three pieces of peeling pieces are formed on one side of the coated steel pipe 9. This peeling piece is dropped on the dolly of the film removing device and discharged to the outside of the device by a suction device (not shown) or the like. Further, in the present embodiment, the pressing cylinder 12 is used as the pressing means of the vertical blade 7, but an AC servomotor or the like may be used.

The present invention was carried out by selecting a coated steel pipe 9 having a two-layer polyethylene coating (coating thickness, about 3 mm). Table 1 summarizes the operating conditions and effects of the apparatus at that time. Further, although the above-mentioned embodiment is the removal of the coating at the pipe end, the present invention is not limited to this, and it is possible to perform smoothly at any position of the steel pipe (for example, when connecting a branch pipe). Is.

[0016]

[Table 1]

[0017]

As described above, according to the present invention,
(1) A part of the tube coating can be removed by online processing, (2) Stripping processing in the refining process becomes unnecessary, and (3)
Since the coating cutting machine also serves as stripping, a device dedicated to stripping is unnecessary.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating the concept of a film removing apparatus according to the present invention.

FIG. 2 is a view showing a contact portion between adjacent steel pipes.

FIG. 3 is a view showing a conventional coating cutting state, (a)
Shows a front surface (b) and a side surface.

FIG. 4 is a view showing a state in which a cutting blade is attached to the cutter head of the present invention.

5 is a view in which the circumferential blade at the position A in FIG. 4 is attached to the cutter head.

FIG. 6 is a plan view of FIG. 5;

FIG. 7 is a front view of FIG. 5;

FIG. 8 is a view in which the vertical blade at the position B in FIG. 4 is attached to the cutter head.

9 is a side view of FIG.

FIG. 10 is a front view of FIG.

FIG. 11 is a diagram schematically showing a film peeling state after cutting with a vertical blade.

FIG. 12 is a view of the coating film cutting machine according to the present invention as seen from the front of the coating line.

[Explanation of symbols]

 1 Steel pipe (base pipe) 2 Core (aluminum connector) 3 Tape 4 Circumferential cutting blade (circumferential blade) 5 Coating cutting machine 6 Coating 7 Vertical cutting blade (vertical blade) 8 Rotating drum-shaped cutter head 9 Coated steel pipe 10 Bogie 11 Electrothermal heater 12 Air cylinder (compression cylinder) 13 Shaft 14 Bearing 15 Shaft box 16 Screw shaft 17 Belt 18 Rotating knob 19 Metal fitting 20 Sliding frame 21 Clamp 22 Screw 23 Metal fitting 24 Conveyor roller 25 Coating processing line (line)

Claims (5)

[Claims] 1. A part of a coating covering the entire coated steel pipe is cut,
A method for removing a coating film from a coated steel pipe end portion, characterized in that the coating film is partially cut and the cut coating film is peeled off on a coating treatment line. 2. The method for removing a coating film from a coated steel pipe according to claim 1, wherein the cutting is performed in a circumferential direction and an axial direction of the pipe, and the stripping is performed by a cutting blade used for the axial cutting. 3. A part of the coating covering the coated steel pipe is circumferentially cut, at least one circumferential cutting blade, at least one longitudinal cutting blade is cut in the pipe axial direction, the circumferential cutting blade, and A rotating drum-shaped cutter head that holds a vertical cutting blade and rotates about the pipe axis of the coated steel pipe to cause the vertical cutting blade to strip the coating film, and a pipe of the coated steel pipe on which the cutter head is mounted. A coat removing device for a coated steel pipe, comprising a carriage movable in the axial direction. 4. The coating film removing apparatus for a coated steel pipe according to claim 3, further comprising an electric heater for heating the circumferential cutting blade and / or the vertical cutting blade. 5. The coating film removing apparatus for a coated steel pipe according to claim 3, wherein the carriage is provided with a clamp for gripping the coated steel pipe.