JPS6277121A - Pipe forming device - Google Patents

Abstract

PURPOSE:To increase the product quality by abutting a press roll to the width end face of the upper and lower roll with its providing and further by giving pressure to the strip plate end face via the press roll. CONSTITUTION:The lower roll 1 is provided freely rotatably on a bearing base 7 and the upper roll 2 is supported to the rolling reduction frame 8 of angular shape as well. A screw rod 13 is made coming in and out by driving a driving motor 15, further a pressing roller 21 is abutted to the end face of a strip plate 3 by a pressing cylinder 22. The width end part is then bent by descending the rolling reduction frame 8 via a rolling reduction motor 11 and by pinching the strip plate 3 by the lower roll 1 and upper roll 2. In this case, the press roller 21 is abutted to the end face of the strip plate 3 and it presses the strip plate end face with the pressure of the pressing cylinder 22. The shear drop of the width end lower edge of the strip plate 3 in bend forming is prevented and the product quality is increased with this method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tube forming apparatus used in the manufacturing process of thick-walled tubes.

[Prior Art] Thick-walled pipes are manufactured by sequentially forming band-shaped flat plates into circular shapes using a forming mill, abutting both width ends of the band plates, and welding the abutted portions.

Generally, when bending a flat plate, the strip plate 3 is compressed by the lower roll 1 and the upper roll 2.2 as shown in FIGS. 2 and 3.
First, the width end portions are bent and then further bent into a circular shape using forming rolls 4.5 whose working degree is increased sequentially. Once the bending is completed, both width ends are welded using a required welding machine.

[Problems to be Solved by the Invention] However, in the above-described conventional method, sagging occurs at the lower edge of the width end due to bending of both width ends.

That is, as shown in FIG. 4, when the strip plate 3 is compressed by the lower roll 1 and the upper roll 2, the width end part is bent and formed, and at the same time, the lower width end part A is plastically deformed and is bent. Put it away.

Therefore, in a tube formed by the conventional method, a dent is formed on the tube surface side of the abutment part B, as shown in FIG. I end up.

In view of the above circumstances, the present invention attempts to prevent plastic deformation from occurring at the lower edge of the width end during width end processing.

[Means for Solving the Problems] The present invention provides a method in which at least the upper roll of the upper and lower rolls for bending and forming the width end portion by pinching the band plate is made narrow, and a pressure roll is brought into contact with the width end surface. The device is characterized in that it is configured so that a pressing force is applied through the.

[Function] By applying a pressing force to the width edge of the strip using the pressure roll, a bending force is applied to the width edge, and this bending force significantly reduces the clamping force between the upper and lower rolls required to form the strip. Ru.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

The lower roll 1 is rotatably provided via a bearing stand 7, and is rotated by a required drive device (not shown). The upper roll 2 is rotatably supported by a chevron-shaped rolling frame 8. The outer peripheral surfaces of the lower roll 1 and the upper roll 2 are formed so that when the strip 3 is compressed, the width end of the strip 3 is bent upward and the strip cross section becomes arched, and the upper roll 2 is It is narrower by the required amount than the strip 3 to be formed. The roll-down frame 8 can be pressed downwards by a roll-down screw 9.9 and is pulled upwards by a balance cylinder 10.

11 is a reduction motor for moving the reduction screw 9;
12 is a drive conversion unit consisting of a gearbox, nut, etc.

Screw rods 13 are provided at both ends of the reduction frame 8,
13 is provided so as to be able to move in and out toward the center via a nut unit 14, and the nut unit 14 and a drive motor 15 attached to the upper surface of the rolling frame are connected to the universal joint 1.
Connect by 6.

Pressing roll units 17.17 are symmetrically provided at the tip of the screw rod 13.13.

The configuration of the roll unit 17 is as follows.

A pedestal 19 is attached to the tip of the screw rod 13, and a slider 20 is provided on the pedestal 19 so as to be slidable in the tangential direction of the strip end. A pressing roller 21 is provided on the slider 20 so as to be rotatable about an axis perpendicular to the tangent,
The slider 20 is connected to the rond of a pressing cylinder 22 attached to the pedestal 19.

Next, the operation will be explained.

Drive the drive motor 15 to move the screw rod 13 in and out, move the pedestal 19 so that the pressing surface of the pressing roller 21 is on the tangent to the width end of the strip, and then move the pressing cylinder 2
2, the pressing roller 21 is brought into contact with the end surface of the band plate 3.

The reduction frame 8 is lowered by the reduction motor 11 via the reduction screw 9, and the lower roll 1 and the upper roll 2 pinch the strip plate 3 to curve the width end portion. Since the upper roll 2 is narrower than the strip plate 3, the end of the strip plate 3 is bent upward while sticking out, but the pressing roller 21 is in contact with the end surface of the strip plate 3. , lower roll 1, upper roll 2
At the same time, the screw rod 13 is pushed out by the drive motor 15, and the pressing force is activated by the pressing cylinder 22, so that the pressing roller 21 is pressed against the end surface of the strip.

A bending force is applied to the end of the strip 3 by the pressure of the pressing roller 21, which facilitates bending of the width end of the strip 3 by the lower roll 1 and the upper roll 2.

That is, in the above device, the clamping force required between the lower roll 1 and the upper roll 2 for bending is greatly reduced, and the edge of the strip is not pressed by the lower roll or upper roll during bending. Sagging of the lower edge of the width end can be prevented.

In the above embodiment, only the upper roll has a narrow width, but it goes without saying that the lower roll may also have a narrow width, or the upper and lower rolls may have the same width.

[Effects of the Invention] As described above, according to the present invention, pressing force is applied to the end face of the strip and the squeezing force between the lower roll and the upper roll is reduced, thereby preventing sagging of the lower edge of the width end and preventing shape defects. can be improved,
Product quality of thick-walled pipes can be improved.

[Brief explanation of drawings]

FIG. 1 is a front view of a tube forming apparatus according to the present invention, FIG. 2 is an explanatory diagram of a conventional example, FIG. 3 is an explanatory diagram of a conventional example, and FIG. 4 is an explanatory diagram showing a bending state in the conventional example. Figure @5 is an explanatory diagram showing a problem when forming a tube according to a conventional example. 1 is a lower roll, 2 is an upper roll, 3 is a strip plate, and 21 is a pressing roll. Patent application Hitoshi Kawajima Bankara Heavy Industries Co., Ltd. Figure 2 Figure 4 Figure 3 Figure 5

Claims (1)

[Claims] 1) A tube forming apparatus characterized in that a pressure roll is brought into contact with the width end surfaces of the upper and lower rolls that pinch the band plate to bend and form the width end portion, and a pressure force is applied via the pressure roll.