JPH03180211A - Device for forming welded pipe - Google Patents

Abstract

PURPOSE:To prevent the blank pipe from being warped downward, to guide to the fin pass roll and to achieve the stable forming by arranging the bottom guide roll to receive the blank pipe at the final zone of the cage roll forming zone. CONSTITUTION:The bottom guide roll BGR receives the bottom part of blank pipe at the final zone L of the cage roll forming zone and prevents the blank pipe from being warped downward. Therefore, the blank pipe can maintain the normal pass line and the top of the blank pipe can be accurately guided to the next fin pass roll 1F and so it is not generated that the forming can not be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an F6 contact pipe forming device using a cage roll forming method.

``Prior Art'' One of the conventional fs connecting pipe forming apparatuses is the one shown in FIG. 1 which partially employs a cage roll forming method (for example, Japanese Patent Application Laid-open No. 135428/1982).

This device includes, from the upstream side to the downstream side, F-Siphominkroll EF, first to fourth centerhentrol IcB.
, 2CB, 3CB, 4CB and a large number of cage rolls CR..., CR..., and a plurality of fin pass rolls IF arranged on both sides of these rolls.

2F, 3F, and squeeze rolls SQ are arranged in sequence, and the edge forming roll EF bends the raw pipe edge of the strip, and the first to third center pend rolls IC8, 2CB, 3CI3 and cage roll CR are formed. ...
, CR... bend the boundary between the side part of the raw pipe and the bottom of the raw pipe, and bend the fourth center pend roll 4CB and 'r.
-'; a-/L/CR..., CR... to bend the bottom part of the raw tube to form a raw tube with a 0-shaped cross section, and then further fin pass roll IF. , 2F, and 3F to make the side part of the raw pipe protrude, and to form the edge part of the raw pipe, the boundary between the edge part of the raw pipe and the side part of the raw pipe, and the side part of the raw pipe and the bottom part of the raw pipe. The boundary portion is bent and unbended, and the joint is upset tg using a welder (not shown) and a squeeze roll SQ.

``Problems to be Solved by the Invention'' However, in this type of device, the raw tube is warped downward by the force applied from the cage roll in the final zone L of the cage roll forming zone, and when threading the strip, the tip of the raw tube is bent downward. It may not smoothly enter the first fin pass roll IF, and may come off the pass line, making it impossible to form.

Also, even if it enters, the first fin pass roll I
F's contact with the lower roll becomes strong, making roll flaws more likely to occur. Furthermore, when the left and right cage rolls are used to perform width-aligning forming, the bottom portion of the raw tube may be locally bent and deformed, resulting in a poor bottom shape.

The present invention attempts to eliminate these conventional drawbacks and to achieve stable molding.

"Means for Solving the Problems" The present invention is a welded pipe forming apparatus using a cage roll forming method, and is characterized in that a bottom guide roll for receiving the raw pipe is disposed in the final zone of the cage roll forming zone.

"Function" With the above structure, the bottom guide roll receives the bottom part of the raw tube at the final stage of cage roll forming, prevents the raw tube from warping downward, and creates a regular pass line for the raw tube. Maintain it and guide it correctly to the next fin bath roll.

"Embodiment" The drawings show an embodiment of the present invention, in which the final zone L of the cage roll forming zone is configured as shown in FIGS. 2 to 4 in the apparatus shown in FIG. 1 already described.

That is, a pot guide roll stand 3 is placed between the left and right cage roll stands 2, 2 installed on the robe 1.

Therefore, the left and right cage roll stands 2.2 are
Three cage rolls CR... are arranged above the stand body 21, 21 installed above, and these cage rolls are controlled by angle adjustment mechanisms 22..., elevation adjustment machines f123..., and It is mounted on the stand main body 21, 21 via a forward/backward adjusting mechanism 24, and each final cage roll is provided with an auxiliary roll CR'.

The bottom guide roll stand 3 has girder members 311, 311 installed between the stand main bodies 2121 of the left and right cage roll stands 2, 2, and a fitting 312 provided on the girder members, so that the stand main body 31 is fl Above the uniform, three bottom guide rolls BGR... are arranged in sequence along a line, and these bottom guide rolls are each connected to each pair of bearings 32°32 provided on the uniform. It consists of a shaft bearing.

1. Effects of the Invention According to the present invention, since the bottom guide rolls support the bottom part of the raw pipe, the raw pipe does not bend downward even in the final cage of the cage roll forming zone, and therefore, the raw pipe always has a regular position. The pass line can be maintained, the tip of the blank tube is correctly guided to the next fin bath roll, and molding is not impossible.

Further, since the raw pipe can maintain a regular pass line, the next fin pass roll does not come into strong contact with the lower roll, and roll flaws can be prevented from occurring.

Further, the bottom guide rolls restrain the bottom portion of the raw tube, thereby preventing local bending deformation of the bottom portion of the raw tube when the left and right cage rolls perform width-aligning forming.

Therefore, the operating rate and yield can be improved, and stable molding can be achieved.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the line configuration of the welded pipe forming apparatus of the present invention, and FIGS. 2 to 4 show examples of the present invention.
The figure is a side view, FIG. 3 is a plan view, and FIG. 4 is a cutaway front view. CR...Cage roll L...Final zone IF of cage roll forming zone, 2
F, 3F...Fin pass roll SQ...Squeeze roll B'GR...Bottom guide roll ■...Basic version 2...Cage roll stand 3...Bottom guide roll stand

Claims (1)

[Claims] A welded pipe forming apparatus using a cage roll forming method, characterized in that a bottom guide roll for receiving a blank pipe is arranged in the final zone of the cage roll forming zone.