JPH07164022A - Inclined rolling mill for producing seamless pipe - Google Patents

Abstract

PURPOSE:To prevent an increase in a gap caused by the deformation and the shifting of a disk roll during rolling. CONSTITUTION:Disk rolls 2U and 2D are arranged opposite to each other in the vertical direction on both sides of a pass center in a position where they are matched with inclined rolls 1R and 1L. And, roller devices 3, 3 which are two shift blocking members, are arranged on the side surfaces on the outlet sides of the rotation of a material H to be rolled of the disk roll 2U (2D), and the rotary shaft of the roller, is set in the radial direction on the side surface of the disk roll 2U (2D). The roller devices 3, 3... are made to come into contact with the side surfaces of the disk rolls 2U and 2D, and rotate following in the rotations of the disk rolls 2U and 2D, thereby blocking the shifting of the disk rolls 2U and 2D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piercing or rolling mill for producing seamless pipes.

[0002]

2. Description of the Related Art FIG. 3 is a schematic elevational view for explaining the problems of a conventional inclined rolling mill as seen from the rolling-out side. In the figure, a pair of inclined rolls 1R and 1L are cone-shaped inclined rolls having a flank angle, and are arranged facing each other on both left and right sides such that their own axes have a crossing angle with a predetermined path center interposed therebetween. , And is rotationally driven about respective different rotation axes having a predetermined inclination angle in opposite directions with respect to the path center. The large-diameter disk rolls 2U and 2D are vertically opposed to each other across the path center at a position aligned with the inclined rolls 1R and 1L in the longitudinal direction of the path center, and are arranged in a plane including the path center. It is driven to rotate about another rotation axis.

When a seamless pipe is manufactured by the above-described inclined rolling mill, the material H to be rolled is placed along the path center.
Is fed, the material H to be rolled is caught between the inclined rolls 1R and 1L, and is rotated by the rotation of the inclined rolls 1R and 1L. The swinging of the material H to be rolled at this time is suppressed by the peripheral surfaces of the disk rolls 2U and 2D which are rotationally driven following, whereby the rolling is smoothly performed.

During such rolling, the material to be rolled H
Is a rolling reaction force applied to the inclined rolls 1R, 1L in the direction of separating from the path center to the left and right, as indicated by the black arrow. As a result, the inclined rolls 1R and 1L are separated from the material H to be rolled as shown by the two-dot chain line in FIG.
The separation distance (gap) between the R, 1L and the peripheral edge portions of the disk rolls 2U, 2D becomes large.

Further, as shown in FIG. 4, the material H to be rolled also gives the disc rolls 2U and 2D a force as a rolling down reaction force indicated by a black arrow in the direction of vertically separating from the path center. As a result, the disc rolls 2U and 2D are separated from the material H to be rolled as indicated by the chain double-dashed line, and the inclined roll 1
The separation distance between the R, 1L and the peripheral edge portion of the disk rolls 2U, 2D becomes large. FIG. 4 is a schematic elevational view for explaining the problems of the conventional inclined rolling mill.

The increase in the separation distance between the inclined roll and the peripheral edge portion of the disc roll during rolling as described above increases the gap between the inclined roll and the disc roll as compared with the state of the initial setting. The expansion of such a gap involves rolling the pipe wall of the rolled material into the gap,
It causes peeling on the surface of the rolled material.

As a solution to this problem, there has been proposed a method and an apparatus for rolling a seamless pipe in which a disk roll is arranged so that its axis has a skew angle with which it is twisted with respect to a path center (Japanese Patent Laid-Open No. 2000-242242). 63-90396 publication). This arrangement of the disc rolls reduces the gap between the disc rolls and the inclined rolls, and prevents the rolled material from being caught in the gaps.

In order to further reduce the gap during rolling, the inventors of the present invention set the disc roll inclination angle at which the axis of the disc roll intersects the plane including the center point of the gorge portion of each inclined roll and the skew. A rolling method and apparatus arranged so as to have a corner is proposed (Japanese Patent Application No. 3-359775). This makes it possible to make the gap between the edge portion of the peripheral surface of the disk roll, which is the rotation-entry side of the material to be rolled, and the surface of the inclined roll close to the peripheral edge portion as close to zero as possible.

Further, the inventors of the present invention use a disc roll having an annular groove formed in the peripheral edge portion of the side surface, so that the gap between the disc roll and the inclined roll on the rotation-entry side of the material to be rolled can be further reduced. A rolling mill is proposed (Japanese Patent Application No. 4-112153).

[0010]

With such a proposal, the gap between the disc roll and the inclined roll in the initial setting of rolling can be made as small as possible.
However, during rolling, a force due to friction is applied from the material to be rolled H to the contact surface of the disk roll with the material to be rolled H, so that the disk roll is deformed or displaced in the direction away from the material to be rolled. The phenomenon occurs.

FIG. 5 is a schematic elevational view for explaining the problems of the conventional inclined rolling mill. The constituent members and the arrangement thereof are the same as those in FIG. The material to be rolled H is rotating around the path center, and the contact surfaces of the disk rolls 2U and 2D with the material to be rolled H are tangential to the direction of rotation due to the friction with the material to be rolled H and are shown in white in the figure. The force indicated by the hollow arrow is applied. As a result, as shown by the chain double-dashed line in FIG.
Circumferential surface edge of U of the rolled material on the rotation entry side and inclined roll 1R
And a gap G2 between the peripheral edge portion of the disc roll 2D on the side of the rolled material to be rolled in and the inclined roll 1L.

The expansion of the gap is caused by the small ratio of the thickness to the diameter of the disc roll and the small bending rigidity of the disc roll. The thickness of the disc roll is determined from the outer diameter target value of the material to be rolled, and does not exceed the distance between the pair of inclined rolls. Further, in order to prevent contact between the drive shaft of the disc roll and the roll chock supporting the inclined roll, it is necessary to increase the disc roll diameter. For these reasons, it is impossible to increase the ratio of the thickness to the diameter of the disc roll, and as a result, the bending rigidity of the disc roll becomes weak, and it is impossible to prevent the gap between the inclined roll and the disc roll from expanding. .

Another cause is that the bending rigidity of the disk roll shaft is small. FIG. 6 is a schematic elevational view for explaining the problems of the conventional inclined rolling mill.
The constituent members and the arrangement thereof are the same as those in FIG. 3, and the corresponding parts are designated by the same reference numerals and the description thereof will be omitted. As indicated by the chain double-dashed line in FIG. 6, during rolling of the rolled material H, the rolled material H is applied to each of the disc rolls 2U and 2D as in the case shown in FIG.
A tangential force is applied in the rotational direction of the material H to be rolled by the contact surface with the disk roll shaft having a small bending rigidity. As a result, the disc roll 2U is slanted to the inclined roll 1R side and the disc roll 2D is slanted to the inclined roll 1L side, and the gaps G1 and G2 described above are further expanded.

In order to increase the bending rigidity, the drive shaft may be thickened. However, in order to prevent contact with the roll chock that supports the inclined roll, it is necessary to make the drive shaft of the disc roll thin, and making the drive shaft thick causes a problem of increasing the size of the device.

The present invention has been made in view of the above circumstances, and by providing the movement preventing member on the side surface of the disk roll, the tangential force in the rotational direction of the material to be rolled during rolling is applied to the disk roll. An object of the present invention is to provide a tilt rolling mill for producing a seamless pipe, which prevents expansion of a gap caused by being applied to a contact portion of a material to be rolled.

[0016]

The inclined rolling mill for producing a seamless pipe according to the present invention uses a pair of inclined rolls and a pair of disc rolls and moves in the axial direction while rotating around the axis center. In the inclined pipe mill for seamless pipe manufacturing, in which the material to be rolled is brought into contact with the peripheral surface of the disk roll to pierce or expand the diameter, the movement of the disk roll to the rotation start side with respect to the disk roll of the material to be rolled is prevented. The movement preventing member is provided so as to face the side surface of the disk roll on the rotation start side.

[0017]

In the inclined rolling mill for producing a seamless pipe of the present invention, since the movement preventing member faces the side of the disk roll on the side where the material to be rolled is rotated out of the side of the disk roll, during rolling, Even if a frictional force is applied to the peripheral surface of the disk roll that comes into contact with the material to be rolled, the portion near the peripheral surface moves in the exit direction of the disk roll in the direction of rotation of the material to be rolled, for example, by deformation. You will not be punished. Therefore, it is possible to prevent the gap formed by the disk roll edge portion and the inclined roll peripheral surface on the rotation start side of the material to be rolled from increasing.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. FIG. 1 is a schematic elevational view of an inclined rolling mill of the present invention as seen from the rolling-out side. In the figure,
The pair of inclined rolls 1R and 1L are cone-shaped inclined rolls having a flank angle, and are arranged on both the left and right sides so that their own axes form a crossing angle with a predetermined path center interposed therebetween. With respect to each other, they are rotationally driven in opposite directions to each other about respective rotation axes having a predetermined inclination angle. The material H to be rolled is bitten between the roll gaps of the inclined rolls 1R and 1L and rolled while being rotationally moved.

The large diameter disc rolls 2U, 2D
Is arranged in a position vertically aligned with the inclined rolls 1R and 1L in the longitudinal direction of the path center, and is vertically opposed to the path center, and its peripheral surface is brought into contact with the material H to be rolled.
Each of them is driven to rotate around its own rotation axis. The disc rolls 2U and 2D have their own axes twisted with respect to the path center, and are provided with a skew angle so that the exit side thereof is opposite to the rotation direction of the material H to be rolled, and the entry side thereof. The side surfaces are inclined toward the inclined rolls 1R and 1L, respectively, so that the disc roll inclination angle is given. Further, the disc rolls 2U and 2D have a ring groove on the peripheral edge of the side surface. FIG. 2 shows a schematic sectional view of the disc roll. The ring groove is close to the bulging portions of the inclined rolls 1R and 1L, and the gap between the rotation entrance side of the rolled material H of the disc rolls 2U and 2D and the inclined rolls 1R and 1L becomes substantially zero.

Then, the two roller devices 3 and 3 which are the movement preventing members are provided on the side surface of the disk roll 2U on the side where the material H to be rolled is rotated and the rotation axis of the roller is set to the disk roll 2
It is arranged at a position separated from the gorge portion of the inclined roll 1L in the radial direction of the U side surface by a predetermined distance on the rolling-in side and the rolling-out side. Similarly, two roller devices 3 and 3 are arranged on the side surface of the disk roll 2D on the rotation start side of the material H to be rolled. The roller devices 3, 3 ... Are composed of a roller portion and a roller supporting portion, and the roller supporting portion is the inclined rolls 1R, 1
L and the disc rolls 2U and 2D are connected to a support device (not shown) that is attached independently. The roller portion is brought into contact with the side surfaces of the disc rolls 2U and 2D,
It is adapted to rotate following the rotation of the disk rolls 2U, 2D.

As a result of rolling the material H to be rolled using the inclined rolling machine constructed as described above, the disk rolls 2U, 2
Due to insufficient rigidity of D and the inclined rolls 1R, 1L, an increase in these intervals was observed, but the disc roll 2U,
Virtually no increase in the gap due to 2D deformation was observed. The rolling conditions are shown below.

Inclined roll: Roll gorge diameter 410mm,
Inlet side angle 3 °, Outer side angle 4 ° Cross angle 30 °, Inclination angle 12 ° Gorge roll gap 62mm Disc roll: Diameter 1200mm, Width 50mm Maximum gap between disc rolls 70mm Skew angle (δ) 4 °, Disc roll Inclination angle (κ) 2
0 ° Roller device: Roller diameter 100mm Installation position (distance from gorge part) 400mm (both input side and output side) Rolled material: Carbon steel 70mm diameter, heated at 1200 ℃, outer diameter after piercing and rolling 91mm

In order to investigate the deformed state of the disk rolls 2U, 2D when rolling is performed under such rolling conditions, a differential transformer is attached to the supporting portions of the roller devices 3, 3, ... Was measured. As a result, the displacement is 0.2 mm ~
It is 0.3 mm, and it can be seen that the disk rolls 2U and 2D are hardly deformed. In addition, when the displacement of the supporting portion is disconnected from the supporting device and the displacement is measured without fixing the supporting portion, the displacement is 1.2 mm to 1.5 mm, and the deformation of the disk rolls 2U and 2D that occurs during rolling. It can be said that the roller device is blocking.

Further, as a result of making the thickness of the material H to be rolled as thin as possible under the same rolling conditions, it was possible to pierce and roll to a thickness of 1.8 mm and a thickness / outer diameter of 2%. Moreover, the result of performing the same piercing rolling with the conventional inclined rolling mill was that the wall thickness / outer diameter could be up to 2.2%, but peeling occurred on the surface of the rolled material with more rolling than this. . From this, it is understood that the thin-wall rolling limit in the stretching rolling can be reduced by using the apparatus of this example.

In the present embodiment, the roller device is used as the movement preventing member, but the present invention is not limited to this, and for example, a non-rotating sliding block member may be used, and the number of installation is one. 1 or 3 for disc roll
One or more pieces may be disposed, and any structure may be used as long as it can prevent the movement of the disk roll toward the rolled-out side of the rolled material.

In this embodiment, the case where the disc roll is provided so as to have the skew angle and the disc roll inclination angle has been described. However, the present invention is not limited to this, and at least one of the skew angle and the disc roll inclination angle. One or both of them may be zero. Further, in the present embodiment, the disk roll having the ring groove on the peripheral edge is used, but the present invention is not limited to this, and a normal disk roll having no ring groove may be used.

[0027]

As described above, in the present invention, since the movement preventing member is provided on the side surface of the disk roll on the side where the rolled material is rolled out, the device does not have to be upsized and the disk can be rolled during rolling. The present invention has excellent effects such as preventing the roll from being deformed or moving, and preventing the gap formed between the disc roll and the inclined roll from expanding.

[Brief description of drawings]

FIG. 1 is a schematic elevational view of an inclined rolling mill of the present invention viewed from its rolling exit side.

FIG. 2 is a schematic sectional view of a disc roll.

FIG. 3 is a schematic elevational view for explaining the problems of the conventional inclined rolling mill.

FIG. 4 is a schematic elevational view for explaining the problems of the conventional inclined rolling mill.

FIG. 5 is a schematic elevational view for explaining the problems of the conventional inclined rolling mill.

FIG. 6 is a schematic elevational view for explaining a problem of a conventional inclined rolling mill.

[Explanation of symbols]

 1R, 1L inclined roll 2U, 2D disk roll 3 roll device H rolled material

Claims (1)

[Claims] 1. A pair of inclined rolls and a pair of disk rolls are used to perforate or expand a material to be rolled that rotates in the axial center direction while rotating around the center of axis and is brought into contact with the peripheral surface of the disk roll. In an inclined rolling mill for producing a seamless pipe having a diameter, a movement preventing member that prevents the movement of the disk roll of the material to be rolled to the disk roll is exposed to the side surface of the disk roll on the rotation output side. An inclined rolling mill for producing seamless pipes, which is equipped with.