JPS63303625A - Production of thin-walled pipe and its apparatus - Google Patents

Abstract

PURPOSE:To obtain a thin-walled pipe high in forming speed and welding speed and improved in mass-productivity by compression-forming a strip in forming pairs of shoes from both sides of the strip into a circular form and butt-welding both edge parts of the strip after a first half breakdown forming is completed by edge bending. CONSTITUTION:In a cold roll-forming, the edges of the strip is bent by rolls and when the first half breakdown forming of all forming processes has been completed, the edges of the strip are bent like an strip S1. Groups 1, 1 of pairs of forming shoes like a long strip of paper having a half cylindrical recess 2 and a notch 3 making up a welding groove are brought sequentially into contact with the strip S1, advanced synchronously, compressed separately and formed into a circle as the process goes ahead. In the formed strip material both edge parts are welded by a welding equipment to obtain a thin-walled pipe.

Description

[Detailed description of the invention] Industrial field of application This invention is applicable to wall thicknesses of 0.5 mm or less, and even 0.1 m.
It relates to a pipe manufacturing method for forming ultra-thin strip material with a diameter of less than 1.5 m into a pipe of a required diameter.In particular, when manufacturing ultra-thin walled and small-diameter pipes, it has excellent formability with less green liquid and deformation, and also has excellent formability at seams. The present invention relates to a method and apparatus for producing thin-walled tubes that have high weldability without discrepancies or openings, have high forming and welding speeds, and are excellent in mass production.

BACKGROUND ART A common method for making pipes is to form a strip into a tubular shape by roll forming, and then weld the abutting portions of the edges of the strip.

In this method, for example, in the case of a copper strip, it is manufactured as a so-called electric resistance welded steel pipe by various roll arrangements in the order of preforming, breakdown, fin pass, and squeeze.
In the case of thin-walled materials, the springback is strong, causing various problems in formability and seam weldability, and various improvements have been made.

However, with the roll forming method, the wall thickness is 0.5m.
BACKGROUND ART It has been considered extremely difficult to form an extremely thin strip material with a thickness of less than 0.1 mm, or even less than 0.1 mm, into a pipe with a required diameter of, for example, several fences.

In other words, green liquid is likely to be generated when forming ultra-thin strip material, which may cause discrepancies in the seam during welding, and the squeeze pressure decreases once it passes the squeeze point. It was difficult to use rolls, and it was necessary to weld while preventing the squeeze pressure from decreasing using auxiliary rolls or shoes.

Furthermore, when welding is performed at a high speed, springback is large due to the thin plate, and the squeeze pressure decreases before solidification of the welded area is completed, which tends to cause the welded area to open.

Furthermore, since the material is thin, even if the seams are aligned during molding, heat such as arc heat will cause thermal stress and deformation.
This made welding difficult because the butt condition collapsed.

On the other hand, conventionally, as a method for producing ultra-thin-walled, small-diameter pipes, there is a method in which a larger pipe is roll-formed and seam welded, and then pultruded to the required diameter. When it is necessary to insert an optical cable, etc. into a small diameter pipe after pipe making, it is difficult to insert it into a small diameter pipe, so the pipe is formed into the required diameter from the beginning, and the required diameter is inserted from the point where the edge butt part is open before welding. Although it is desirable to insert cables and the like, no pipe-making method or apparatus for this purpose has been proposed.

Purpose of the Invention This invention provides a wall thickness of 0.5 without using a drawing method.
The purpose is to provide a pipe-making method and device for forming ultra-thin strip material of 0.1 mm or less into a pipe of a desired diameter. The object of the present invention is to provide a method and apparatus for manufacturing thin-walled tubes that have no differences or openings, have high weldability, have high forming and welding speeds, and are excellent in mass production.

SUMMARY AND EFFECTS OF THE INVENTION According to the present invention, when pipe-forming an ultra-thin strip material with a wall thickness of 0.5 mm or less into a required small diameter, the first half is broken down by edge forming with rolls, and then, for example, A large number of shoe blocks with semicircular recessed end faces placed opposite to each other are attached to the endless chain via attachments to enable synchronized movement with the band material, and the side opposite to the contact surface of the forming shoe block to the band material. Then, by bringing back-up rolls, guides, etc. into contact with each other, the distance between the forming shoes of each village is gradually narrowed until the squeeze point is reached, and before and after the squeeze point, the forming shoes of each village are completely brought into contact with each other. When the abutting parts of the strips exposed from the upper groove of the shoe are welded, for example, by laser beam welding, they are held in the shoe and the shoe block functions as a cooling ring, so there is no thermal deformation. In addition, since the squeeze pressure is constant over the required distance in the longitudinal direction, the squeeze pressure does not decrease during melting and solidification.
Good welding is possible, and high-speed welding of 10 m/min or more is possible.

Furthermore, by the pipe making method and apparatus according to the present invention, the wall thickness is 0.
．． A material with a diameter of 1 mm or less can be made into a tube with a diameter of about 1 mm, with excellent formability and weldability, and can be manufactured efficiently.

In addition, it is possible to form a tube with a required diameter of about 1 mm from the beginning, and to insert an optical cable or the like through the open edge abutting portion before welding, making it possible to apply it to new uses.

Structure of the Invention This invention is a method of making a thin-walled tube by forming a thin-walled strip material and welding the edge abutting portions. , A pair of forming shoes are provided in the vertical end surface of the shoes, which are short pieces in the direction of the strip material, with a recess that can cover the semicircular portion of the tube after forming, so that they can abut from the side direction of the strip material. A large number of pairs are arranged in the direction of the material, and the forming shoes are brought into contact sequentially from the side of the strip material that has completed breakdown forming and progresses, and the shoes of each village are temporarily moved in the opposite direction while running in synchronization with the strip material. A method for manufacturing a thin-walled pipe, which comprises: pressing and forming the strip into a desired circular shape as it progresses, and after completing the required forming, welding the abutting edges while being pressed and gripped by the forming shoe. It is.

In addition, the present invention provides a roller chain that slides on a leveler guide installed on a base and rotates in a required orbit, and is equipped with a large number of strip-shaped guide shoes via fastening members, and The lower surface of each guide shoe slides into contact with the leveler guide installed on the base, and a semicircular recess is formed on the short side end surface and a notch that becomes a welding groove is formed at the upper end of the recess. A forming shoe group is comprised of a forming shoe group in which a pair of rectangular forming shoes are slidably held on the upper surface of each guide shoe with the recessed portions facing each other, and the forming shoe group is configured to hold a pair of rectangular forming shoes slidably on the upper surface of each guide shoe, and the forming shoe group A guide and l or a backup roll are provided that contact the outer surface of each forming shoe so that the forming shoes in each village contact each other by shortening their facing distance for a while until the forming shoe contacts the required squeeze point. Furthermore, a back-up roll with a vertical axis is provided at a position sandwiching the forming shoe before and after the squeeze point, and the shoe ring that contacts and presses the outward end surface of the forming shoe in each village is applied to the roll surface via an elastic material. A welding device is arranged so that heat can be input to the abutting edge of the strip through the welding window formed by the forming shoes of each village that abut each other at the squeeze point, This thin-walled tube manufacturing apparatus is characterized in that means for separating the forming shoe from the tube after welding is completed is disposed downstream of the squeeze point.

In the present invention, the manufacturing device includes an endless forming shoe group in which a large number of rectangular forming shoe elbows are arranged, each having a semicircular recess on the short side end face and a notch serving as a welding window at the upper end of the recess; - a guide or backup roll that contacts the outer end surface, upper surface, etc. of each forming shoe for the purpose of temporarily shortening the facing distance and bringing the forming shoes of each village into contact with each other until a required squeeze point;
In addition to the configuration of the embodiment, various configurations can be adopted as long as the configuration includes a welding device and separation means for each shoe.

Any known welding method can be used, such as TIG welding or laser beam welding, as long as the heat input can be concentrated on the edge abutment in the welding groove of the shoe.

Further, since the forming shoe and the guide shoe form a cooling mass and radiate welding heat, there is little residual thermal stress in the thin-walled tube, and a tube with excellent weldability and excellent welding properties can be obtained. 'The means for approaching or separating the forming shoes of each village can be applied in various ways in addition to the configuration of the embodiment. By incorporating a spring and constantly separating the material, for example, separating it to the extent that it can separate from the pipe after welding, and using a guide on the upstream side to separate it so that the distance is wider than the width of the strip material after breakdown is completed,
It is also preferable to have a configuration in which they are brought into contact with each other by the force of a shoe press guide or the like during forming, and are separated from each other at the same time as they are released from the pressure of the backup roll after welding.

In addition, by providing a protruding pawl on the upper surface of the forming shoe and bringing the pawl into contact with a separation guide provided downstream from the welding device, it is possible to separate the forming shoes from each other, or to separate the forming shoes from each other when they arrive at a desired position. Various methods such as pulling in the direction of separation,
Configurations available.

Based on the drawings〈Disclosure of the invention Fig. 1 is an explanatory view of the configuration of an endless forming shoe group showing the forming process according to the present invention, Fig. A is an explanatory top view, and Fig. B is a longitudinal cross-sectional explanatory view of each pair of shoes in Fig. A. It is. However, the drawings show only eight stages out of the continuous molding stages.

FIG. 2 is an explanatory diagram showing the thin-walled pipe manufacturing apparatus according to the present invention, FIG. Figure A is an explanatory sectional view taken along line b-b, and Figure C is an explanatory cross-sectional view taken along line c-c in figure b, which shows the guide plate.

FIG. 3 shows a thin-walled tube manufacturing apparatus according to the present invention, and is a longitudinal cross-sectional view of FIG. 2a, looking at the contact surface of the shoe.
The guide strip (15) on the left side of the center line of S) indicates the entry side, and the guide strip (15) on the right side indicates the squeeze point.

First, the method for forming a thin-walled tube according to the present invention will be explained based on FIG.
The process can be roughly divided into the stage of completing the first half of the entire forming process up to breakdown forming as shown in 1), the forming process using a forming shoe as shown in Figure 1a, and the welding process.

That is, the strip material is edge bent using rolls in a general cold roll forming mill.
After completing the first half of the entire molding process up to the breakdown molding, the sheet material progresses in an edge-bent state like the strip material (Sl) shown in FIG.

Here, a semicircular recess (2) capable of enclosing the semicircular part of the tube after forming is formed on the vertical end surface of the short side in the direction of movement of the strip, and a welding groove (2) is formed at the upper end of this recess (2). 4) Notch (3)
A plurality of pairs of rectangular forming shoes (IXI) are arranged in the direction of the strip (S) and can be pressed by coming into contact with the strip (S) from the edge to the center from the side direction of the strip (S). A group of forming shoes (IXI) which are arranged in series and rotate endlessly like a caterpillar are arranged downstream of the cold roll forming mill.

Next, the strip material (
Forming shoes (IXI) are sequentially brought into contact with the side surface of S) and run in synchronization with the strip material (S), and the shoes (IXI) of each village are temporarily pressed in the opposite direction while running in synchronization with the strip material (S). As step (S) progresses, it is shaped into the desired circular shape.

Furthermore, the strip material (Sn) that has completed the required forming is pressed and held by the forming shoe (IXI) group, and
The edge portion is welded using a welding device that can face the abutting edge portion from above to obtain a thin-walled tube.

The outline of the forming method has been explained above, but to further explain the details of the apparatus, as shown in Figs. A rectangular guide shoe (22) is attached via a fastening member (21) between a pair of roller chains (20) that slide on leveler guides (11) and (12) and rotate in a required elliptical orbit. A large number of them are mounted and arranged in series in the track direction.

Further, the lower surfaces of the plurality of guide shoes (22) are slid into contact with a central leveler guide (13) installed in the center of the base (10) between the roller chains (20).

Therefore, a large number of guide shoes (22) that are fixed to the roller chain (20) with an elliptical orbit and rotate in synchronization with the roller chain (20) move on the parallel two leveler guides (11, 12). 20) slides and the lower surfaces of the guide shoes (22) contact and slide on the center leveler guide (13) surface, so the height level of the upper surface of the guide shoe (22) is lower than that of the roller chain (20). ) is held constant and highly accurate regardless of the accuracy of

In addition, each village of the forming shoe (IXI) mentioned above has a groove on the lower surface, and one guide shoe (
22) The protruding stripes (23) provided in the longitudinal direction of the upper surface are fitted with the aforementioned dovetail grooves, and the short side end surfaces provided with semicircular recesses (2) are made to face each other. (23) Endless forming shoe (IXI) configured to be able to slide freely on the top
forming a group.

The above endless forming shoe (1) (1) group rotates on an elliptical orbit of a roller chain (20) stretched between a pair of foils, but on the base (10) As shown, the forming shoes (IXI) of each village are running in synchronization while sequentially contacting the progressing strip material (S) from the side direction after completion of breakdown forming, and the forming shoes (IXI) of each village temporarily shorten the opposing distance until the required squeeze point. The opposing distance is controlled by a guide plate (14) so that they come into contact with each other in a compressed manner, and gradually separate from each other after the squeeze point.

The guide plate (14) is mounted on the back surface of a support substrate (16) horizontally suspended between the upper ends of the vertical axes of a pair of vertically supported backup rolls (30), which will be described later, so as to face the base (10). has been done.

The guide plate (14) has a plate shape, and two guide strips (15) having a roughly L-shaped cross section are provided on the surface facing the forming shoe (IXI) group in the direction of movement of the strip material. The forming shoe (IXI) is configured to fit into and come into contact with a groove (5) and a convex portion (6) provided on the upper surface of each forming shoe (IXI).

The second guide line (15) is designed so that the forming shoes (1) (1) of each village contact each other by shortening their facing distance for a while until the required squeeze point, and gradually separate from each other after the squeeze point. The arrangement is such that the facing distance is controlled.

This guide plate (14) allows the forming shoe (
When the forming shoes (IXI) sequentially contact the strip material from the side direction and run in synchronization, and the pair of forming shoes (IXI) temporarily shorten their facing distance and completely contact each other, the strip material forms a pipe (Sn) of the required diameter. This completes the forming process and moves on to the welding stage.

A backup roll (30) supported by a vertical axis is provided at a position sandwiching the forming shoes (IXI) that are in contact with each other before and after the squeeze point, and is in contact with the outward end surface of the forming shoes (IXI) in each village. It has a configuration in which a shoe ring (31) for suppressing is provided around the roll surface of a backup roll (30) via an elastic material (32).

By providing the shoe ring (31) around the roll surface of the backup roll (30) via the elastic material (32), the form of contact with the outward end surface of the forming shoe (IXI) changes from point contact to line contact. The pressing force becomes constant and wide-ranging.

As shown in Figure 2a (see Figure 1), the forming shoes (IXI) of each village contact each other at the squeeze point.
A welding device is arranged so as to be able to input heat to the abutting edge of the strip (Sn) through the welding groove (4) formed in the step.

For example, the opening of the guide plate (14) and the welding groove (4)
), the abutting portions of the strips exposed from
Since the Gatsu shoe (IXI) functions as a cooling mass without causing springback while being held in the IXI), thermal deformation is less likely to occur, and the squeeze pressure over the required distance in the longitudinal direction is constant. Therefore, during melting and solidification, the squeeze pressure does not decrease and good welding is possible.
High-speed welding of in or more is possible.

Endless forming shoe (IXI) group +, t,
After welding is completed, it is turned over at the downstream end of the base (10), and again comes into contact with the strip material after breakdown has been completed at the upstream end.

Therefore, the opposing distance of the forming shoes (IXI) group is controlled by the guide strip (15) of the guide plate (14) so that they gradually separate from each other after the squeeze point.
0) Another guide plate (17) arranged on the elliptical orbital plane to provide the required facing distance to allow contact with the strip material after breakdown is completed when separated from the upper guide plate (14).
The guide strip (18) maintains the required distance and moves upstream.

[Brief explanation of drawings]

FIG. 1 is an explanatory view of the configuration of a group of endless forming shoes showing the forming process according to the present invention, where FIG. 1A is an explanatory top view, and FIG. However, the drawings show only eight stages out of the continuous molding stages. FIG. 2 is an explanatory diagram showing the thin-walled pipe manufacturing apparatus according to the present invention, FIG. Figure A is an explanatory sectional view taken along line b-b, and Figure C is an explanatory cross-sectional view taken along line c-c in figure b, which shows the guide plate. FIG. 3 shows a thin-walled tube manufacturing apparatus according to the present invention, and is a longitudinal cross-sectional view of FIG. 2a, looking at the contact surface of the shoe.
The guide line (15) on the left side of the center line in 8) indicates the entry side, and the guide line (15) on the right side indicates the squeeze point. 1... forming shoe, 2... recess, 3...
Notch, 4... Welding groove, 5... Groove, 6...
Convex portion, 10... Base, 11.12... Leveler guide, 13... Center leveler guide, 14.17...
Guide plate, 15.18... Guide strip, 16... Support substrate, 20... Roller chain, 21... Fixing member,
22... Guide shoe, 30... Backup roll, 31... Shoe ring, 32... Elastic body. 1st (a) (b) 5I strip material

Claims (1)

[Scope of Claims] 1. In a pipe-making method in which a thin-walled pipe is formed by forming a thin-walled strip material and welding the edge abutting portions, after completing the first half of the entire forming process up to breakdown forming by edge bending using rolls. , A pair of forming shoes are provided in the vertical end surface of the shoes, which are short pieces in the direction of the strip material, with a recess that can cover the semicircular portion of the tube after forming, so that they can abut from the side direction of the strip material. A large number of pairs are arranged in the direction of the material, and the forming shoes are sequentially contacted from the side of the strip material that has completed breakdown forming and is progressing, and the shoes of each pair are temporarily moved in the opposite direction while running in synchronization with the strip material. A method for manufacturing a thin-walled tube, characterized in that the strip material is pressed and formed into a desired circular shape as it progresses, and after the required forming is completed, the abutting edge portions are welded while being pressed and gripped by the forming shoe. . 2. A large number of strip-shaped guide shoes are mounted via fixing members on a roller chain that slides on a leveler guide installed on a base and rotates in a required orbit, and are arranged in a connected manner in the orbit direction. , the lower surface of each guide shoe slides into contact with a leveler guide installed on the base, and a strip-shaped forming having a semi-cylindrical recess on the short side end face and a notch serving as a welding groove at the upper end of the recess a pair of shoes with the recesses facing each other,
It is composed of a group of forming shoes slidably held on the upper surface of each guide shoe, and the group of forming shoes sequentially abuts from the side surface of the strip material after breakdown forming and runs synchronously, and each pair of forming shoes Each pair of forming shoes has a guide that contacts the outer surface of each forming shoe and one or more backup rolls for temporarily shortening the opposing distance and bringing the forming shoes into contact until a required squeeze point, and each pair of forming shoes contact each other at the squeeze point. The welding device is arranged so that heat can be input to the abutting edge of the strip material through the welding window formed by the above-mentioned squeeze point. A thin-walled pipe manufacturing device characterized by being located downstream. 3. A backup roll with a vertical axis is provided at a position sandwiching the forming shoes before and after the squeeze point, and a shoe ring that abuts and presses the outward end surface of each pair of forming shoes is arranged on the roll surface via an elastic material. An apparatus for manufacturing a thin-walled tube according to claim 2.