JPH02187215A - Manufacture of ribbed pipe - Google Patents

Abstract

PURPOSE:To enable the mass production of strong pipe by causing plastic deformation in pipe and manufacturing continuously ribbed pipe formed projecting ribs without recessed grooves on the wall surface. CONSTITUTION:On forming rolls, special rolls 9 which tapering projecting parts 7 are located on one side and recessed parts 8 opposed to them are located on the other side are incorporated as the first roll 9a, the second roll 9b and the third roll 9c in order toward the direction of travel and a strip is formed into a projecting and recessed surface by the forced rotation of these special rolls 9. Continually, the other pair of special rolls 14 which, on the surrounding direction of roll, the roll on the upper part side is a plane roll 12 and the roll on the lower part side is a recessed roll 13 which the width of recessed part is reduced gradually toward the direction of travel are located as the forth roll 14a, the fifth roll 14b and the sixth roll 14c toward the direction of travel and the recessed grooves 11 are blocked by pressing and mating the projecting ribs 10 together gradually from both sides. Then the strip is formed tubularly and plural projecting ribs in blocking state are formed on the longitudinal peripheral wall of pipe integrally and continuously and the projecting ribs 10 are projected inside the pipe and blocked concave grooves 11 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing ribbed pipes suitable for fields requiring exceptional strength such as reinforcement materials for construction.

[Prior Art] Conventionally, as a method for continuously manufacturing pipes, a strip is passed through forming rolls made up of a plurality of pairs of flat rolls and curved rolls arranged in series to form a tubular shape. There is a method of heating and welding both ends to form a tubular body.

[Problems to be Solved by the Invention] By the way, ribs are also called inner ribs and are reinforcing members attached to reinforce plate-like or thin-walled parts. Conventionally, in continuous pipe manufacturing methods, ribs are There was no way to continuously manufacture integrally ribbed pipe.

However, forming ribs on the peripheral wall of the pipe is desirable from the viewpoint of reinforcing the vibrator material, and since the pipe diameter increases due to the ribs protruding from the peripheral wall, it is economical as it requires less material than a normal pipe of the same diameter. In a method for continuously manufacturing pipes, it would be desirable to provide a method for manufacturing such ribbed pipes.

Prior to this point, the inventor developed a method for manufacturing a ribbed pipe in which a plurality of reinforcing ribs are integrally and continuously formed over the entire circumferential wall in the longitudinal direction of the pipe.

That is, in a pipe manufacturing method in which a band plate is passed through a series of forming rolls in which a plurality of upper and lower unit forming rolls are arranged in series in the traveling direction and continuously formed into a tubular shape, By incorporating a plurality of pairs of special rolls in which the upper roll has a convex part and the lower roll has a concave part facing the convex part of the upper roll, so that the uneven state gradually increases in the direction of travel. , the strip is continuously rolled according to the uneven shape to form convex ribs on the lower surface and concave grooves on the upper surface, and is further formed into a tubular shape, and a plurality of convex ribs are formed on the outer peripheral wall in the longitudinal direction of the pipe. This is a manufacturing method that involves integral continuous molding.

SUMMARY OF THE INVENTION An object of the present invention is to improve the method for manufacturing such a ribbed pipe, and to provide a method for manufacturing a ribbed pipe with excellent layer strength.

[Means for Solving the Problems] In order to achieve the above object, the present invention further includes, in addition to the above special forming roll, the upper roll is a flat roll and the lower roll is a concave roll in the roll circumferential direction. By incorporating a plurality of pairs of special rolls so that the width of the concave portion of the lower roll gradually decreases in the direction of travel, the convex ribs are gradually pressed from both sides to close the concave grooves and further form a tube. A manufacturing method was adopted in which a plurality of closed convex ribs were integrally and continuously formed on the circumferential wall in the longitudinal direction of the pipe.

That is, the present invention provides a pipe manufacturing method in which a band plate is passed through a series of forming rolls in which a plurality of upper and lower unit forming rolls are arranged in series in the traveling direction and continuously formed into a tubular shape. A pair of special rolls in which the upper roll has a tapered convex part and the lower roll has a concave part facing the convex part of the upper roll in the roll circumferential direction, and the uneven state gradually increases in the traveling direction. By incorporating multiple sets, the strip is continuously rolled according to the uneven shape to form convex ribs on the lower surface and concave grooves on the upper surface, and then continuously in the roll circumferential direction. By incorporating multiple sets of other special rolls in which the upper roll is a flat roll and the lower roll is a concave roll so that the width of the concave portion of the lower roll gradually decreases in the direction of travel, the convex ribs can be formed on both sides. Manufacture of a ribbed pipe characterized by gradually pressing it together from the side to close the concave groove, forming it into a tubular shape, and integrally and continuously forming a plurality of closed convex ribs on the circumferential wall in the longitudinal direction of the pipe. It's a method.

[Function] Therefore, according to this manufacturing method, it is possible to cause plastic deformation in the pipe and to continuously manufacture a pipe having a rib structure integrally formed to project in the longitudinal direction of the pipe circumferential wall. It is possible to obtain a ribbed pipe with exceptional strength compared to a pipe with a non-irregular shape. Moreover, according to the manufacturing method of the present invention, since the protruding ribs are in a closed state, it is possible to continuously manufacture pipes whose strength is significantly improved compared to pipes with ribs in a non-closed state. .

[Example] Figure 1 is a diagram of a square pipe manufacturing process, Figure 2 is a partial schematic diagram of a forming section in the same process, and Figure 3 (() (+7
) (C) (D) (E) are schematic front views of forming rolls in the same forming section, Figure 4 (A) (0) (C) and Figure 5 (() (CI) (C) are special rolls. FIG. 3 is a schematic front view of another special roll.

The pipe manufacturing process for jointed pipes generally involves a pair of upper and lower unit forming rolls, namely a flat roll 1a and curved rolls lb and lc.
, ld, and le are sequentially arranged in series in the direction of travel, and the process of continuously forming the strip plate 2 into a tubular shape, and tightening the joints at both ends of the strip plate 2 with a tightening roll 3. The process consists of a step of welding using resistance heat, a step of forming into a square shape with a forming roll 4, a sizing step 5, and a cutting step 6 of cutting into a predetermined length with a traveling cutter.

In this embodiment, the series of forming rolls 1 are provided with a tapered convex portion 7 on one side and a concave portion 8 opposite to the convex portion 7 on the other side, as shown in FIG. 4(4)(CI)(c). 10 - 9 a
It is incorporated as No. s No. 20-Rule 9b and No. 30-Rule 9C. Note that the special rolls 9 include the 10th to 20th rolls 9a to 20th rolls.
Convex portions 7 and concave portions 8 are provided so that the unevenness of the pipe gradually increases as the pipe progresses through the 30th and 30th rules, and by forced rotation of these special rolls 9, the strip plate 2 forms an uneven surface. do. Note that 10 is a convex rib, and 11 is a concave groove.

Furthermore, in this series of forming rolls 1, following the special roll 9, the upper roll in the roll circumferential direction is the flat roll 1, as shown in FIG.
2. The other pair of special rolls 14, in which the lower roll is a concave roll 13 whose concave width gradually decreases in the direction of travel, are moved in the direction of travel by rolling the 40th roll 14a1 and the 50th roll 14b.
1 No. 60-ru 14c, convex rib 1
0 is gradually pressed from both sides to close the concave groove 11.

Subsequently, this strip plate 2 is formed into a tubular shape, and a plurality of convex ribs in a closed state are continuously formed in one direction on the outer circumferential wall in the longitudinal direction of the pipe. Note that the gap between the forming rolls at this stage is such that the plate thickness increases by the amount of rib formation, so the clearance between the rollers is adjusted as appropriate.

When forming the band plate 2 into a tubular shape, it is preferable to bend it in the direction in which the concave groove 11 is closed. As a result, the concave groove 11 is reliably closed, and the reinforcing effect of the convex ribs is further improved.

Figure 6 shows a pipe obtained by this manufacturing method,
Convex ribs 10 protrude into the pipe, while concave grooves 11 form a closed pipe. Incidentally, the pipe obtained by the manufacturing method invented earlier by the inventor is the seventh
As shown in the figure, the concave groove 11 is in a non-closed state.

By the way, in the above example, the special roll 9. is included in the prostrate roll 1a.
14, curved rolls lb, lc,
It is also possible to adopt a method in which ribs are formed at the same time by incorporating it into ld and le and forming it into a curved shape. Note that when forming convex ribs on the inner surface, due to the structure, it is necessary to apply force in the non-occluding direction during the pipe manufacturing process, so the forming roll 1 may be occluded at a relatively light stage. It is desirable to do so.

Although the above example is a method for manufacturing a square pipe, the present invention is not limited thereto. Further, other methods for joining the pipes may be adopted as appropriate. Although the convex ribs are formed on the entire surface in the above embodiment, the convex ribs are not limited thereto, and a method of forming them partially can also be adopted. Further, although the above manufacturing method is a method of forming the convex rib on the inner wall surface of the pipe, a method of forming the convex rib on the outer circumferential wall is also possible. In addition to steel pipes, various pipe materials such as stainless steel and aluminum can be used.

[Effects of the Invention] As described above, the present invention is a method for continuously manufacturing a ribbed pipe in which a pipe is plastically deformed and a convex rib without a concave groove is formed on the wall surface. It is possible to produce extremely strong pipes in large quantities.

In addition, the pipe obtained by this manufacturing method uses relatively less material than conventional pipes and has the same diameter and width with the same or twice the strength due to the protrusion formation associated with rib formation. Therefore, it is extremely economical, and when the convex rib is formed on the inner surface, the concave groove is closed, so it can be handled in the same way as a normal pipe, and it is beautiful and has excellent practical value.

[Brief explanation of the drawing]

Figure 1 is a diagram of the square pipe manufacturing process, Figure 2 is a partial schematic diagram of the forming section in the same process, Figure 3 is a schematic front view of the forming rolls in the same section, and Figures 4 and 5 are special rolls. and another special roll, FIG. 6 is a perspective view of a ribbed pipe obtained by this manufacturing method, and FIG. 7 is a perspective view of a ribbed vibrator in which the concave groove is in an unoccluded state.

Claims (1)

[Claims] (1) In a pipe manufacturing method in which a band plate is passed through a series of forming rolls in which a plurality of upper and lower unit forming rolls are arranged in series in the traveling direction and continuously formed into a tubular shape, the above forming rolls are A pair of special rolls each having an upper roll having a tapered convex part and a lower roll having a concave part facing the convex part of the upper roll in the direction of travel are arranged so that the concave and convex state gradually increases in the traveling direction. By incorporating multiple sets, the strip is continuously rolled according to the uneven shape to form convex ribs on the lower surface and concave grooves on the upper surface, and then continuously rolls the upper part in the circumferential direction of the roll. By incorporating multiple sets of other special rolls, in which the side roll is a flat roll and the lower roll is a concave roll, so that the concave width of the lower roll gradually decreases in the direction of travel, convex ribs are formed on both sides. A method for producing a ribbed pipe, which comprises gradually pressing the pipe together to close the concave groove, forming the pipe into a tubular shape, and integrally and continuously forming a plurality of closed convex ribs on the circumferential wall in the longitudinal direction of the pipe. .