JPS61249623A - Production of winding steel pipe - Google Patents

Abstract

PURPOSE:To make easy the pipe expansion on the spot with its transportation in the state of reducing the diameter by winding to the inner side one part of the end edge part in the state of the elastic bending of the almost cylindrical pipe body material with unjoining end edge part without giving a plastic bending. CONSTITUTION:The pipe body material 1 of about cylindrical shape with unjoined end edge part formed by bending a steel plate is placed on the roller of a rotary jig 4. The wire rope 6 that the one end is fixed to a fixed jig 3 is then wound on the rotary drum of a driving device 5 after winding it on the outer periphery of the pipe body material 1. The end edge part is then wound to the inner side in the state of elastic bending and becomes in the state 1a of its diameter reduced with the action of the tautening force by the wire rope 6 on the outer diameter of the pipe body material 1 and the sliding force as well by the dead weight of the pipe body material 1 and with the action of a tractive force on the wire rope 6 when the fixed metal fitting which tacks the end edge part of the pipe body material 1 is removed and the driving device 5 is operated. The fixed metal fitting 2 is then taken out by tacking it by the fixed metal fitting 2 and by transferring upto the piping spot.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of manufacturing a rolled steel pipe used as a water supply steel pipe or the like.

<Conventional technology> When installing large-diameter water and sewage pipes in water works, etc., conventionally, a steel plate is bent into a cylindrical body in a factory, and both axial edges are welded together to produce the pipe body. These pipe bodies were transported to a piping site, and piping was performed by connecting a plurality of pipe bodies with their ends in circumferential contact with each other.

However, in this construction method, the pipe body, which has been formed into a large diameter in advance, must be transported from the factory to the site, resulting in extremely poor transport efficiency. Furthermore, when piping is installed inside the genital tract, it is difficult to transport the pipe.

Therefore, recently, instead of performing axial welding of the tube body material, it is transported to the site as a rolled steel tube with one end rolled inward, and then rolled back on site and welded in the axial and circumferential directions. The method of installing piping after doing this has come to be adopted. This is a so-called pipe-in method where a new pipe is inserted into an old pipe, especially when repairing old pipes or repairing and reinforcing private passages.
Often used in pipe construction methods.

The above-mentioned pipe-in-bone pipe construction method includes a method of inserting an ordinary steel pipe manufactured by performing axial welding as described above, and a method of inserting the rolled steel pipe. FIG. 8 is an explanatory diagram showing a construction method using ordinary steel pipes, and FIG. 9 is an explanatory diagram showing a construction method using rolled steel pipes.

Rolled steel pipe is a steel plate that is rolled into a roughly cylindrical body at a temporary factory on site, then transported with the edges rolled inward without axial welding, and then transported at the piping site with its edges rolled inwards. Refers to steel pipes that undergo directional welding. In the construction method shown in Figure 9, which uses rolled steel pipes, the diameter of the new pipe when inserted is made as small as possible, and the inner diameter of the new pipe after construction is completed can be made close to the inner diameter of the old pipe, so that the water flow cross section of the pipe can be can be made larger.

Furthermore, since the diameter of the new pipe at the time of insertion is small, there is an advantage that even if the pipe has a bent part, a pipe with a longer length than that of ordinary steel pipe can be inserted.

<Problems to be Solved by the Invention> The general method for manufacturing rolled steel pipes in a factory is to roll a steel plate and bend it as shown in Figure 6.
As shown in FIG. 7, the tubular body 1a is formed by bending the end edge portions with a neck-shape until the overlapping allowance, that is, the winding allowance, reaches a predetermined value. However, if the bending process is performed until a predetermined folding allowance is reached, the steel plate must be forcibly bent plastically so that the radius of curvature is smaller than the required pipe radius, which makes it difficult to expand the pipe at the piping site. , it takes a lot of time to correct the actual inner diameter of the pipe to a perfect circle, and it becomes a very troublesome work. In addition, when the winding allowance increases, the time required for bending at the factory increases, and the operating efficiency of processing equipment is poor and it is uneconomical.

In order to solve the above-mentioned problems in the conventional method of manufacturing rolled steel pipes, the present invention has developed a winding method in which winding is performed in a natural state without forcing the pipe material to undergo plastic bending. The purpose of this invention is to provide a method for manufacturing steel pipes.

Ninth Means for Solving Problems> The method for manufacturing a rolled steel pipe of the present invention involves wrapping a wire rope around the outer periphery of a substantially cylindrical pipe material with unjoined edges formed by bending a steel plate. The present invention is characterized in that at least one end of the wire rope is pulled to apply a tightening force to the outer diameter of the tubular material so that one end edge of the tubular material is wrapped around the inner surface of the steel plate of the tubular material.

<Function> In the method of the present invention, the tubular material around which the wire rope is wound is subjected to a tightening force on its outer diameter by the wire rope, and the tube material is wrapped in a natural state due to the elastic surface without causing plastic bending. The piping is then temporarily secured and transported to the piping site. Therefore, at the piping site, pipe expansion can be easily performed by removing the temporary fixing.

Embodiments Hereinafter, details of the method of the present invention will be explained based on Examples and drawings.

In the method of the present invention, first, as shown in FIG. 6, the tubular material 1 is made of a steel plate with both end edges whitened to a predetermined radius of curvature, and then processed by rollers so that the entire body has a predetermined radius of curvature. Bending processing is applied. When the bending process is completed, the tubular material 1 that has been bent in this manner is temporarily fastened with the fixing fittings 2 shown in FIG. 5, with both end edges overlapped, resulting in a state as shown in FIG. 3. The tubular material 1 as shown in FIG. 3 is fed into the winding device shown in FIGS. 1 and 2, and the winding operation is performed.

FIG. 1 is a front view showing an embodiment of a winding device used in the method of the present invention, and FIG. 2 is a side view thereof. As seen in the figure, this winding device includes a fixed jig 3, a rotating jig 4,
It is composed of a drive device 5 and a wire rope 6.

The tube material l shown in FIG. 3 is placed on the rollers of the rotating jig 4 so as to be transferable.

The wire rope 6 has one end fixed to the fixing jig 3, is wound around the outer periphery of the tubular material 1, and is also wound around the rotating drum of the drive device 5.

Here, when the fixing metal fitting 2 which temporarily fastened the end edge of the tube material l in the state shown in FIG. 3 is removed and the drive device 5 is operated to rotate the rotating drum, the wire rope In the direction of the arrow shown in the figure, an attractive force acts, and a tightening force acts on the outer diameter of the tubular material 1 around which the wire rope 6 is wound, and the tension force acts on the outer diameter of the tubular material 1. As a result, one edge of the tubular material 1 is rolled inward in a natural state of elastic bending, resulting in four reduced diameter states as shown in the tubular material la shown in the figure. In this way, the body 1a that has been rolled up to a predetermined overlapping allowance, that is, the wrapping allowance, is temporarily fixed with the fixing fittings 2 as shown in Fig. 4, and is transported to the piping site in this state. Ru. In this case, it is preferable that the fixing fittings 2 be attached at two locations, one on the outer edge of the tube body 1a and the other on the inner edge, as shown in the figure. At the pipe site,
This fixing fitting 2 is removed and the end edge portion is left in a clear state for pipe expansion.

Although the above shows one embodiment of the method of the present invention, in another embodiment, the rotating jig 4 is not provided, and the tube material 1 is placed on, for example, a surface plate C. It is also possible to wrap the rope 6 around it and perform the above-mentioned operation. As another fifth example, the above-mentioned fixing jig 3 is not provided, and the drive device 5 is provided on both sides of the device to apply a traction force to both ends of the wire rope 60, and the above-mentioned N-th or The same operation as in the second embodiment may be performed.

<Effects of the invention> t According to the method of mounting a rolled steel pipe of the present invention, W)
Tightness in the tube material due to the traction force of the ear rope ζ
This can be done by applying force and winding the material in a state of natural elastic bending until a predetermined winding allowance is reached. Therefore, the pipe body can be easily transported in the required diameter-reduced state, and the pipe expansion work at the piping site can also be easily carried out. Furthermore, since the winding process is performed in separate equipment from the bending process, the operating rate of the bending equipment is improved. In addition, when the above-mentioned rotating jig is provided, the winding process can be performed even more easily.

[Brief explanation of drawings]

Fig. 1 is a front view of an embodiment of the winding device used in the method of the present invention, Fig. 2 is a side view thereof, Fig. 3 is a diagram showing the state of the tube material before winding, and Fig. 4 is a diagram showing the state of the tube material before winding. FIG. 5 is a cross-sectional view of the fixing fitting, FIG. 6 is a diagram showing the state of bending the tube material, and FIG. 7 is a diagram showing the conventional general winding method. , FIG. 8 is an explanatory diagram of a piping construction method using ordinary steel pipes, and FIG. 9 is an explanatory diagram of a piping construction method using rolled steel pipes. In the drawings, 1 is a tube material, 1a is a tube, 2 is a fixture, 3 is a fixing jig, 4 is a rotating jig, 5 is a driving device, and 6 is a wire quartz.

Claims (1)

[Claims] A wire rope is wound around the outer periphery of a substantially cylindrical tube material with unjoined edges formed by bending a steel plate, and at least one end of the wire rope is pulled to apply a tightening force to the outer diameter of the tube material. 1. A method for manufacturing a rolled steel pipe, characterized in that one end edge of the pipe material is rolled into the inner surface of a steel plate of the pipe material.