JP3897290B2 - Method and apparatus for manufacturing spiral steel pipe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a steel strip coil formed by winding steel strips having different shape materials and properties on the A side and B side, such as a hot-rolled steel strip with projections having projections formed on one side, The present invention relates to a method and an apparatus for manufacturing a spiral steel pipe capable of forming an A surface or a B surface on both a peripheral surface and an outer peripheral surface.
[0002]
[Prior art]
For example, there are two types of spiral steel pipes with protrusions used as steel pipe piles, steel pipe sheet piles, etc. in the construction civil engineering field, with protrusions (usually spiral ridges) on the outer peripheral side and those on the inner peripheral side. . In the case of using a normal hot-rolled steel strip without projections as a method of manufacturing a spiral steel pipe with projections having projections on either the inner peripheral surface or the outer peripheral surface, it is found in JP-A-6-190440. As described above, a roll with projections and depressions is formed on a pass line for rewinding a steel strip coil formed by winding the hot-rolled steel strip without projections, and the projections are formed on the steel strip with the rolls with projections and depressions. There is known a method of forming a spiral steel pipe with a projection by a forming machine composed of a subsequent forming roll or the like while forming. In addition, a method is also known in which protrusions are provided by extra-beads by welding in the middle of molding, without using a protrusion-formed uneven roll.
[0003]
However, as described above, in the method of forming protrusions on the steel strip by forced deformation with a roll with unevenness during rewinding or the method of forming protrusions by applying heat as in welding, the hot-rolled steel strip is deformed. Since it becomes large, forming is not stable, and it is difficult to obtain a high-quality spiral steel pipe with protrusions.
[0004]
On the other hand, a steel strip having projections formed on one side in advance, for example, five projections (projections) 15 are formed at predetermined intervals in the width direction of one side (A surface) as shown in FIG. A method of manufacturing a spiral steel pipe with projections by using a manufacturing apparatus 300 as shown in FIGS. 6 and 7 using a steel strip coil formed by winding a hot-rolled steel strip 11 is also known. Although the manufacturing apparatus 300 shown by FIG. 6 and FIG. 7 is the same structure, the kind of used steel strip coil and the spiral steel pipe obtained differ. That is, in FIG. 6, the steel strip coil (projection inner surface side steel strip coil) 10 wound with the A surface on which the projection 15 is formed being the inner surface side is used, and the projection 15 is disposed on the inner peripheral side. A spiral steel pipe 1 is obtained, and in FIG. 7, a steel strip coil (projection outer surface side steel strip coil) 10 ′ wound with the A surface on which the projection 15 is formed being the outer surface side is used. A spiral steel pipe 1 ′ having protrusions 15 on the outer peripheral side is obtained.
[0005]
The manufacturing apparatus 300 shown in FIGS. 6 and 7 includes a coil holding part 120 that rotatably supports a mandrel 122 holding the steel strip coils 10 and 10 ′, and a pass line for the steel strip coils 10 and 10 ′. A cradle (roll) 180, a roller leveler (strain relief) 140, a feed roll 150, and a rewound steel strip fed from the feed roll 150 as a rewind feed means for rewinding and feeding on P. 11 includes a forming machine 160 including a support roll 162 and a forming roll (not shown) for forming 11 into the spiral steel pipe 1.
[0006]
In the manufacturing apparatus 300, the steel strip coils 10 and 10 ′ are placed on the cradle 180 (when set), and both end portions of the mandrel 122 are moved up and down in the support grooves 124 and 124 of the upper opening in the coil holding unit 120. The steel strip coils 10 and 10 'are unwound from the lower side to be unwound and unwound. At the initial stage of rewinding, the steel strip coils 10 and 10' are rotated by the cradle 180, The starting end portion is sent to the feed roll 150 through the roller leveler 140, and thereafter, the steel strip 11 is rewound by the feed roll 150, and the rewound steel strip 11 is sent to the molding machine 160. 11 is bent so as to draw a clockwise spiral along the traveling direction, and the seam (mating surface) of the side end surface of the steel strip 11 is welded to the inside and outside. They are joined at 71 and 72.
[0007]
As a result, as shown in FIG. 6, when the protrusion inner surface side steel strip coil 10 is used, the spiral steel pipe 1 having the protrusion 15 on the inner peripheral side is formed. As shown in FIG. When the outer surface side steel strip coil 10 'is used, the spiral steel pipe 1' having the protrusion 15 on the outer peripheral side is formed.
[0008]
In the manufacturing apparatus 300, as shown in FIG. 6, the diameter of the spiral steel pipe 1 to be formed and the center line Os are determined by the crossing angle β between the steel strip 11 to be rewound and the spiral steel pipe 1 to be formed. The inclination angle α (usually 40 ° to 50 °) of the protrusion 15 is determined.
[0009]
[Problems to be solved by the invention]
When manufacturing a spiral steel pipe using the conventional manufacturing apparatus 300 as described above, depending on the type of spiral steel pipe to be obtained (whether the protrusion is the inner peripheral side or the outer peripheral side), the type of steel strip coil to be used (the protrusion is the inner surface) Side or external side) must be selected. That is, as shown in FIG. 6, when manufacturing a spiral steel pipe 1 having a protrusion 15 on the inner peripheral side (spiral steel pipe with an inner peripheral protrusion) 1, the A surface on which the protrusion 15 is formed is the inner surface side. In order to manufacture a spiral steel pipe (spiral steel pipe with outer peripheral protrusions) 1 ′ having protrusions 15 on the outer peripheral side as shown in FIG. It is necessary to use the protrusion outer surface side steel strip coil 10 'wound with the A surface on which the protrusion 15 is formed being the outer surface side.
[0010]
Therefore, each time the type of spiral steel pipe to be manufactured is changed, it is required to reassemble the steel strip coil, which requires a lot of labor and time for the recombination work, and the workability and the line operation rate are significantly reduced. was there.
[0011]
In addition, there are about 50 items of steel strip coil depending on the steel strip width, plate thickness, material, etc., with the projections on the inner side and outer side, respectively. There is also a problem that the cost of manufacturing and managing the steel strip coil is high.
[0012]
In addition, the above problem is not only in the case of using a hot-rolled steel strip 11 (steel strip coil) having protrusions formed on one side (A surface) as shown in FIG. As shown in A), for example, when a hot-rolled steel strip 12 made of a clad steel plate having a surface A of SUS304 and a surface B of SS400 is used, or as shown in FIG. The same occurs when the hot-rolled steel strip 13 subjected to surface treatment such as plating is used.
[0013]
The present invention has been made to solve the above-described problems, and the object of the present invention is to provide two types of spiral steel pipes having different shapes, materials, and the like on the inner peripheral surface and the outer peripheral surface in one type of steel strip coil. It is an object of the present invention to provide a method and apparatus for manufacturing a spiral steel pipe that can improve workability, line operation rate, and the like, and can reduce the cost of manufacturing and managing steel strip coils.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the method for manufacturing a spiral steel pipe according to the present invention basically rewinds a steel strip coil formed by winding steel strips having different shapes, materials, and the like on the A and B surfaces. A manufacturing method for forming a spiral steel pipe, wherein the steel strip coil starts to be unwound from the lower side and is rewound to obtain a spiral steel pipe having the one A surface as the inner peripheral side, and the steel strip coil is unwound from the upper side. It is characterized in that a spiral steel pipe having the one A surface as the outer peripheral side is obtained by rewinding for the first time.
[0015]
Another aspect of the spiral steel pipe manufacturing method according to the present invention is basically a steel strip coil in which steel strips having different shapes, materials, and the like on the A and B sides are wound with the A side facing inward. Is a manufacturing method of forming a spiral steel pipe while rewinding, and when manufacturing a spiral steel pipe having the A-side as an inner peripheral side, the A-side is turned up and the A-side is set as an outer peripheral side. When manufacturing a spiral steel pipe, the steel sheet is rewound with the A surface facing downward.
[0016]
As the steel strip used in the method of the present invention, in addition to the hot-rolled steel strip with projections formed on one side, the hot-rolled steel strip made of clad steel plate or one surface was subjected to surface treatment such as coating or plating. Hot rolled steel strip and the like can be mentioned.
[0017]
According to the manufacturing method of the spiral steel pipe according to the present invention having such a configuration, for example, the starting end portion of the protrusion inner surface side steel strip coil (lower part of the unrolling portion) is on the lower side, and the steel strip coil is moved from the lower side. By starting unwinding and rewinding, a spiral steel pipe having an A surface on which protrusions and the like are formed as the inner peripheral side is obtained. On the other hand, by turning the same protrusion inner surface side steel strip coil 180 ° in a vertical plane or a horizontal plane, for example, with the starting end portion (unwinding portion) on the upper side and starting to unwind the steel strip coil from the upper side and rewinding it. A spiral steel pipe having an A surface on which the projections and the like are formed as an outer peripheral side is obtained.
[0018]
Therefore, it is not necessary to prepare two types of steel strip coils, ie, the inner surface side steel strip coil and the outer surface side steel strip coil, as in the prior art. Both a spiral steel pipe and a spiral steel pipe with protrusions on the outer peripheral surface can be manufactured.
[0019]
For this reason, as in the prior art, every time the type of spiral steel pipe to be manufactured is changed, the work of rearranging the steel strip coil becomes unnecessary, and the workability, the line operation rate, etc. are improved.
[0020]
Also, as the steel strip coil, it is only necessary to prepare any one of the protrusion inner surface side steel strip coil and the protrusion outer surface side steel strip coil, so that two types of steel strip coils are prepared as in the prior art. Compared to the case, manufacturing and management costs of the steel strip coil can be reduced.
[0021]
On the other hand, the spiral steel pipe manufacturing apparatus according to the present invention is basically an apparatus for manufacturing a spiral steel pipe while rewinding a steel strip coil formed by winding steel strips having different shapes, materials, and the like on the A and B sides. Then, it can start to be unwound from either the lower side or the upper side of the steel strip coil, and can be rewound on the pass line.
[0022]
Another aspect of the manufacturing apparatus of the spiral steel pipe according to the present invention is a coil holding means having a lifting drive mechanism for supporting and rotating the steel strip coil in a rotatable manner, and rewinding the steel strip coil on a pass line. It comprises a rewind feed means for feeding out, and a forming means for forming a steel strip sent from the rewind feed means into a spiral steel pipe.
[0023]
The coil holding means includes a frame-shaped holding portion having a window-shaped guide portion, and the elevating drive mechanism includes a slide bearing that cantilever-supports a mandrel that rotatably supports the steel strip coil, the slide bearing Is slidably inserted into the window-shaped guide portion. In this case, the elevating drive mechanism is preferably capable of elevating the outer peripheral upper end and the outer peripheral lower end of the steel strip coil to substantially the same level with respect to the pass line.
[0024]
The spiral steel pipe manufacturing apparatus according to the present invention configured as described above can start to be unwound from either the lower side or the upper side of the steel strip coil, and can be rewound on the pass line, Specifically, it is configured to have a coil holding means having a lifting drive mechanism that supports the steel strip coil in a pivotable manner and moves up and down, so that the upper and lower positions of the steel strip coil lower side and upper side at the beginning of unraveling are set. The steel strip coil can be easily set, and the steel strip coil can be rotated and supported at the set position so that the steel strip coil can be unwound. Therefore, it is optimal for carrying out the manufacturing method of the spiral steel pipe of the present invention. is there.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0026]
1 and 2 show a first embodiment of a spiral steel pipe manufacturing apparatus according to the present invention, in which (A) is a schematic side view and (B) is a schematic plan view. In these drawings, the same functional parts corresponding to the respective parts of the conventional manufacturing apparatus 300 shown in FIG. 6 and FIG. 7 described above are denoted by the same reference numerals, and redundant description is omitted. Explain mainly.
[0027]
The manufacturing apparatus 100 of the first embodiment shown in FIG. 1 and FIG. 2 has the same configuration, and the steel strip coils used are also of the same type and the same item, with the A surface on which the projections 15 are formed on the inner surface side. The inner surface of the protrusion-side steel strip coil 10 wound around is different from the set state of the steel strip coil 10 (position, orientation and rotation direction during rewinding) and the type of spiral steel pipe obtained (described later).
[0028]
The manufacturing apparatus 100 according to the present embodiment includes a pair of left and right frames having a lifting drive mechanism 30 that supports a mandrel 22 that holds the steel strip coil 10 so as to be pivotally supported via rectangular slide bearings 32 and 32 and moves up and down. Cradle (not shown), roller leveler 140, and feed roll 150 as rewind feed means for rewinding and feeding the steel strip coil 10 onto the pass line P And a forming machine 160 including a support roll 162 and a forming roll (not shown) for forming the unrolled steel strip 11 sent from the feed roll 150 into the spiral steel pipe 1.
[0029]
The elevating drive mechanism 30 has a pair of left and right hydraulic cylinders 35 and 35 that are mounted downward on the upper surface of the frame-shaped holders 25 and 25 as a drive source. The piston rod tip is connected to the slide bearings 32, 32. The slide bearings 32, 32 are slidably fitted into window-shaped guide portions 26, 26 formed on the frame-shaped holders 25, 25, and the steel strip coil 10 is It is possible to raise and lower the outer peripheral upper end portion and the outer peripheral lower end portion, which become the unraveling portion, to approximately the same level with respect to the pass line P.
[0030]
Here, when manufacturing the spiral steel pipe 1 with the inner circumferential projection, as shown in FIG. 1, the coil holding portion is arranged with the starting end portion (unwinding portion Q) of the projection inner surface side steel strip coil 10 facing down. Set to 20 and start solving from below. In other words, the film is rewound with the A surface on which the protrusions 15 are formed facing upward. At this time, the lower end part of the outer periphery of the steel strip coil 10 (the unrolling start part Q) is maintained at approximately the same level as the pass line P by the lifting drive mechanism 30.
[0031]
Thereby, the steel strip 11 rewound by the feed roll 150 is sent to the molding machine 160, and in the molding machine 160, the steel strip 11 is bent so as to draw a clockwise spiral along the traveling direction, The seam (joint surface) of the side end surfaces of the steel strip 11 is joined by welding torches 71 and 72 from inside and outside. In this case, since the protrusion inner surface side steel strip coil 10 starts to be unwound from the lower side and is rewound with the A surface on which the protrusions 15 are formed facing upward, as in the case shown in FIG. The spiral steel pipe 1 having the protrusions 15 is formed.
[0032]
On the other hand, when manufacturing the spiral steel pipe 1 ′ with the outer peripheral projection, the same inner surface side steel strip coil 10 is rotated by 180 ° in a vertical plane or a horizontal plane, for example, as shown in FIG. The side steel strip coil 10 is set on the coil holding portion 20 with the starting end portion (unwinding portion Q ′) on the upper side and starts to be unwound from the upper side. In other words, the film is rewound with the A surface on which the protrusions 15 are formed facing downward. Under the present circumstances, the raising / lowering drive mechanism 30 maintains the outer peripheral upper end part (unrolling start part Q ') of the steel strip coil 10 at the substantially same level as the pass line P. FIG.
[0033]
Thereby, the steel strip 11 rewound by the feed roll 150 is sent to the molding machine 160, and in the molding machine 160, the steel strip 11 is bent so as to draw a clockwise spiral along the traveling direction, The seam (joint surface) of the side end surfaces of the steel strip 11 is joined by welding torches 71 and 72 from inside and outside. In this case, since the protrusion inner surface side steel strip coil 10 starts to be unwound from the upper side and is rewound with the A surface on which the protrusion 15 is formed facing downward, the protrusion 15 is formed on the outer peripheral side as in the case shown in FIG. A spiral steel pipe 1 'is formed.
[0034]
By doing in this way, it becomes unnecessary to prepare two types of steel strip coils of the projection inner surface side steel strip coil 10 and the projection outer surface side steel strip coil 10 'as in the prior art, and any one type of steel strip coil is eliminated. As a result, both the spiral steel pipe 1 having the protrusion on the inner peripheral surface and the spiral steel pipe 1 'having the protrusion on the outer peripheral surface can be manufactured.
[0035]
For this reason, as in the prior art, every time the type of spiral steel pipe to be manufactured is changed, the work of rearranging the steel strip coil becomes unnecessary, and the workability, the line operation rate, etc. are improved.
[0036]
Also, as the steel strip coil, it is only necessary to prepare any one of the protrusion inner surface side steel strip coil and the protrusion outer surface side steel strip coil, so that two types of steel strip coils are prepared as in the prior art. Compared to the case, manufacturing and management costs of the steel strip coil can be reduced.
[0037]
3 is a schematic perspective view showing a second embodiment of the spiral steel pipe manufacturing apparatus according to the present invention, FIG. 4 is a detailed view as viewed from the arrow X in FIG. 3, and FIG. 5 is a detailed view as viewed from the arrow Y in FIG. is there.
[0038]
In the manufacturing apparatus 200 of the second embodiment, the steel strip coil 10 is cantilevered by the coil holding portion 40 in order to facilitate the setting of the steel strip coil 10 and the like. In other words, the coil holding part 40 cantileverly supports the mandrel 42 holding the steel strip coil 10 via the rectangular slide bearing 52 and can be lifted and lowered, as can be understood with reference to FIGS. A frame-like holding body 45 having an elevating drive mechanism 50 is provided. The frame-shaped holding body 45 is mounted on a support frame 56 that is slidable on the rails 44, 44 by a hydraulic ram 83.
[0039]
The elevating drive mechanism 50 has a hydraulic cylinder 55 attached downward to the upper surface of the frame-shaped holding body 45 as a drive source, and the piston rod tip of the hydraulic cylinder 55 is connected to the slide bearing 52. ing. The slide bearing 52 is slidably inserted into a window-shaped guide portion 46 formed on the frame-shaped holding body 45 and is moved up and down by a hydraulic cylinder 55 in the vertical direction.
[0040]
On the right side of the coil holding part 40, a cradle (roll) 80 is provided for setting the steel strip coil 10 to the coil holding part 40 and rotating the starting end part of the steel strip coil 10 to feed it to the feed roll 70. ing. The cradle 80 is rotationally driven by a driving motor 85 and is moved forward and backward on the rails 84 and 84 by a moving motor 83 in the left-right direction.
[0041]
When setting the steel strip coil 10 to the coil holding portion 40, when manufacturing the spiral steel pipe 1 with the inner peripheral projection, the projecting inner surface side steel strip coil 10 has the starting end (unwinding portion) on the lower side, Further, when manufacturing the spiral steel pipe 1 ′ with outer peripheral projections, the protruding inner surface side steel strip coil 10 is placed on the cradle 80 with the starting end portion (unwinding portion) on the upper side and placed on the cradle 80. The mandrel 42 is moved up and down by the lift drive mechanism 50 so that the center axis of the mandrel 42 coincides with the center line Oc of the steel strip coil 10. After that, the cradle 80 on which the steel strip coil 10 is placed is advanced to the coil holding portion 50 side, and the steel strip coil 10 is extrapolated and held on the mandrel 42. In this case, one end surface of the steel strip coil 10 is abutted and locked to a face plate 48 externally fitted and fixed to the mandrel 42, and the other end surface is brought into and out of operation by operating the air rotary joint 47. It is locked by.
[0042]
In this state, when manufacturing the spiral steel pipe 1 with the inner peripheral projection, as in the first embodiment (in the case shown in FIG. 1) described above, the starting end portion of the projection inner surface side steel strip coil 10 (the unwinding portion) Start solving from below with Q) down. In other words, the film is rewound with the A surface on which the protrusions 15 are formed facing upward. On the other hand, when manufacturing the spiral steel pipe 1 ′ with the outer peripheral projection, similarly to the above-described first embodiment (in the case shown in FIG. 2), the start end portion (unwinding portion Q ') On top and start solving from above. In other words, the film is rewound with the A surface on which the protrusions 15 are formed facing downward. At the time of the rewinding molding, the steel strip coil 10 is rewound from the steel strip coil 10 while the steel strip coil 10 is pressed by the pressing rollers 91, 92, 93 and the like for preventing the steel strip coil 10 from being lifted. 62 (when rewinding from the lower side), or is fed to the feed roll 70 while being guided by the guide roller 65 whose position is adjustable, and sent from the feed roller 70 to a molding machine (not shown) via the leveler 75. In this molding machine, as in the first embodiment, the steel strip 11 is bent so as to draw a clockwise spiral along the traveling direction, and the seam (mating surface) of the side end surface of the steel strip 11 is formed. ) Are joined from the inside and outside by a welding torch, and the spiral steel pipe 1 with the inner circumferential protrusion or the spiral steel pipe 1 ′ with the outer circumferential projection is formed according to the respective unwinding modes.
[0043]
Therefore, even when the manufacturing apparatus 200 according to the second embodiment is used, substantially the same effects as those of the first embodiment described above can be obtained.
[0044]
In addition, in the said embodiment, although the hot-rolled steel strip 11 with a protrusion by which the protrusion 15 was formed in one side as shown in FIG. 8 was used as a steel strip, it replaces with that, and FIG. 9 (A) As shown in FIG. 9, a hot-rolled steel strip 12 made of a clad steel plate, or a hot-rolled steel strip 13 or the like having a surface treatment such as coating 16 or plating as shown in FIG. The present invention can also be applied when used.
[0045]
【The invention's effect】
As can be understood from the above description, according to the method and apparatus for manufacturing a spiral steel pipe according to the present invention, two types of spiral steel pipes having different shapes, materials, and the like on the inner peripheral surface and the outer peripheral surface in one type of steel strip coil. As a result, it is possible to improve the workability, the line operation rate, etc., and to reduce the manufacturing and management costs of the steel strip coil.
[Brief description of the drawings]
1A and 1B show a state in which a spiral steel pipe with inner peripheral projections is being manufactured by a first embodiment of a spiral steel pipe manufacturing apparatus according to the present invention, wherein FIG. 1A is a schematic side view, and FIG.
FIGS. 2A and 2B show a state where a spiral steel pipe with outer peripheral projections is manufactured by the first embodiment of the spiral steel pipe manufacturing apparatus according to the present invention, wherein FIG. 2A is a schematic side view, and FIG. 2B is a schematic plan view.
FIG. 3 is a schematic perspective view showing a main part of a second embodiment of the spiral steel pipe manufacturing apparatus according to the present invention.
4 is a detailed view taken in the direction of arrow X in FIG. 3;
FIG. 5 is a detailed view taken along arrow Y in FIG. 3;
6A and 6B show a state in which a spiral steel pipe with inner peripheral projections is manufactured by a conventional spiral steel pipe manufacturing apparatus, in which FIG. 6A is a schematic side view, and FIG. 6B is a schematic plan view.
7A and 7B show a state in which a spiral steel pipe with outer peripheral projections is manufactured by a conventional spiral steel pipe manufacturing apparatus, where FIG. 7A is a schematic side view, and FIG. 7B is a schematic plan view.
FIG. 8 is a cross-sectional view showing a steel strip having protrusions formed on one side.
9A is a cross-sectional view showing a hot-rolled steel strip made of a clad steel plate, and FIG. 9B is a cross-sectional view showing a hot-rolled steel strip coated on one side.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Spiral steel pipe with inner periphery protrusion 1 'Spiral steel pipe with outer periphery protrusion 10 Projection inner surface side steel strip coil 11 Steel strip 20, 40 Coil holding part 30, 50 Lifting drive mechanism 35, 55 Hydraulic cylinder 70, 150 Feed roll 160 Molding machine

Claims (9)

A manufacturing method for forming a spiral steel pipe while rewinding a steel strip coil formed by winding steel strips having different shapes, material properties, etc., on the A and B sides, and starting to unwind the steel strip coil from the lower side. Thus, a spiral steel pipe having the one A surface as the inner peripheral side is obtained, and a spiral steel pipe having the one A surface as the outer peripheral side is obtained by starting to unwind the steel strip coil from the upper side. A method for producing a spiral steel pipe, comprising: A manufacturing method of forming a spiral steel pipe while rewinding a steel strip coil in which steel strips having different shapes, material properties, etc., are formed on the A surface and the A surface inside. When manufacturing a spiral steel pipe having a circumferential side, the A surface is faced upward, and when revolving, a spiral steel pipe having the A surface being the outer peripheral side is rewound with the A side facing downward. A method for producing a spiral steel pipe, characterized by comprising: The manufacturing method according to claim 1 or 2, wherein the steel strip is a hot-rolled steel strip with a protrusion having a protrusion formed on one side. The manufacturing method according to claim 1, wherein the steel strip is a hot-rolled steel strip made of a clad steel plate. The manufacturing method according to claim 1, wherein the steel strip is a hot-rolled steel strip having a surface treatment such as painting or plating on one side. An apparatus for producing a spiral steel pipe while rewinding a steel strip coil formed by winding steel strips having different shapes, material properties, etc. on both sides, and the steel strip coil can be unwound from either the lower side or the upper side. An apparatus for producing a spiral steel pipe, wherein the apparatus can be rewound on a pass line. Coil holding means having a raising and lowering drive mechanism for supporting and rotating the steel strip coil in a rotatable manner, rewind feed means for rewinding and feeding the steel strip coil on a pass line, and sent from the rewind feed means And a forming means for forming the incoming steel strip into a spiral steel pipe. The coil holding means includes a frame-shaped holding portion having a window-shaped guide portion, and the elevating drive mechanism includes a slide bearing that cantilever-supports a mandrel that rotatably supports the steel strip coil, the slide bearing The spiral steel pipe manufacturing apparatus according to claim 7, wherein the sliding guide pipe is slidably fitted into the window-shaped guide portion. The said raising / lowering drive means can raise / lower the outer periphery upper end part and outer periphery lower end part used as the part which starts the said steel strip coil to substantially the same level with respect to the said pass line, It is characterized by the above-mentioned. The manufacturing apparatus of the spiral steel pipe of 7 or 8.

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