JPH0342103A - Rolling control method for reeler roll - Google Patents

Abstract

PURPOSE:To prevent excessive rolling reduction of a tube as an objective to be rolled by controlling a crossed axes angle so that ratio of a repulsive force of roll on the inlet side of reeler rolls to a repulsive force of roll on the outlet side of them is made into a specified number. CONSTITUTION:A crossing angle gamma is given to the roll shafts of the reeler rolls 21, 22 and the tube 1 is rolled using a reeler plug 3. Then, the crossed axes angle gamma is controlled using a computing element 6 and control device 4 for crossed axes angle so that the ratio (a/b) of the repulsive force (a) of roll on the inlet side of the reeler rolls 21, 22 to the repulsive force (b) of roll on the outlet side of the reeler rolls 21, 22 is made over 0.5 and below 3.0. Thereby, quality of product and efficiency of reeling can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rolling control method in a gluer for polishing the inner and outer surfaces of a seamless pipe.

[Conventional technology]

To manufacture seamless steel pipes using the Mannesmann plug mill method, a piercer is used to perforate the axial center of a heated billet, the wall is made thinner and the diameter is expanded using an elongator, and the diameter is expanded using a plug culle. This is done by reeling the outer surface and finishing it to the specified dimensions with sipes.

In the reeling step, internal rolling is performed simultaneously with the diameter expansion of the tube using a reeler consisting of a reeler roll and a reeler plug.

FIG. 4 is a schematic partially cutaway plan view showing the main parts of the reeler, and FIG. 5 is a schematic front view thereof.

A beam is placed in the center between the cylindrical reeler rolls 41 and 42.
A love rug 43 is arranged. In order to perform reeling by applying a frictional force to the tube 1 caught in the rolls 4142 and moving the tube 1 spirally in its length direction while penetrating the plug 43, move the rolls 41 and 42 in the same direction. It is necessary to rotate the rolls at the same speed, and to tilt the respective roll axes in opposite directions with respect to the horizontal direction by an angle of inclination β.

Slanting the tube in this way is necessary to provide propulsive force to the tube, but on the other hand, this slope reduces the contact area between the roll and the tube, so the tube cannot be rolled smoothly. The polishing ability of the tube may be reduced and the quality of the inner and outer surfaces of the tube may deteriorate.

Therefore, in order to reduce the distance between the rolls on the biting side (input side) of the tube, the roll axes of the rolls are rotated by an intersection angle γ (rolling) to increase the contact area between the roll and the tube on the input side of the reeler roll 4L42. Conventionally, efforts have been made to improve reeling efficiency and polishing ability.

Figure 6 shows the case where the crossing angle γ is not given, and Figure 7 shows the crossing angle T.
It is a graph showing the distance between rolls when given, the vertical axis shows the separation between the rolls, and the horizontal axis shows the position of the rolls (the entrance side and the exit side of the reeler roll 4L42).

As is clear from FIGS. 6 and 7, if the crossing angle T is not given, the roll will contact the pipe only at one point in its center,
Roll and Pipe 1 The contact area between the roll and plug is small,
Therefore, reeling efficiency and polishing ability are low. On the other hand, when the crossing angle T is given, the contact area on the entrance side of the rolls is large, and the reeling efficiency is high.

By the way, the appropriate value of the crossing angle T varies with changes in operating conditions during rolling, such as the outer diameter of the tube, wall thickness, steel type, temperature, etc., and is not constant. For this reason, conventionally, an operator has determined the crossing angle T from the state of the plug surface after use. However, such a crossing angle control method cannot cope with changes in operating conditions and cannot obtain an appropriate crossing angle γ. Therefore, there is a need for a rolling control method that appropriately controls the intersecting angle of the rolls.

As a method for controlling the rolling of the reeler roll, for example, in Japanese Patent Application Laid-Open No. 57-64407, the number of rotations of the rolling roll, the roll diameter, the finished outer diameter of the material to be rolled, and a prespecified control designation per rotation of the material to be rolled are disclosed. The angle at which the plane including the gorge intersects the tube axis (gorge angle) according to the control period calculated from the number of times.

A method for controlling the lead position of a plug, etc. is disclosed.

[Problem to be solved by the invention]

However, although the above-described rolling control method makes it possible to obtain a tube with excellent roundness in the longitudinal direction, it is not possible to improve the reeling efficiency.

Therefore, the present inventor conducted experiments and research to develop a rolling control method for appropriately controlling the crossing angle T of the rolls as a rolling control method for improving pipe quality and reeling efficiency.The results were as follows. , when the tube is rolled down by the rolls, the repulsive force from the tube to the rolls (roll repulsion force) is measured on the input side and the exit side, and the roll repulsion force a on the input side and the roll repulsion force on the output side are calculated. Calculate the ratio a/b and calculate the intersection angle T based on that value.
We found a way to properly control this.

The present invention has been made based on such knowledge, and its purpose is to reduce the intersection of the reeler rolls based on the ratio a/b of the roll repulsion force a on the input side and the roll repulsion force on the output side. An object of the present invention is to provide an eleventh method for controlling the rolling of a reeler roll, which improves the quality of a tube as an object to be rolled and has high reeling efficiency by controlling the angle.

[Means to solve the problem]

A rolling control method 11 for a reeler roll according to the present invention is a rolling control method for a reeler roll in which the roll axis of the reeler roll is made at an intersecting angle to perform rolling, and the roll repulsion force a on the entrance side of the reeler roll and the roll repulsion force a on the exit side of the reeler roll are The intersecting angle is controlled so that the ratio a/b to the roll repulsion force is 0.5 or more and 3.0 or less.

[Effect]

In the rolling control method for a reeler roll according to the present invention,
The ratio a/b of the roll repulsion force a on the inlet side of the reeler roll to the roll repulsion force on the outlet side of the reeler roll is 0.5 or more 3
．． The intersection angle is controlled so that it is 0 or less.

Thereby, the contact length between the reeler plug and the pipe is maintained at a certain level or more, and smooth reeling is performed. Further, the tube, which is the object to be rolled, is prevented from being rolled down excessively near the entrance and exit sides of the reeler roll.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on drawings showing embodiments thereof.

FIG. 1 is a schematic partially cutaway plan view showing an apparatus for carrying out the rolling control method for a reeler roll according to the present invention;
The figure is a schematic front view thereof. In the figure, 21.22
are the leeler rolls and these leeler rolls 21.2
A beam-love rug 3 is placed in the center between the two. The reeler rolls 21 and 22 are each tilted by an inclination angle β in opposite directions with respect to a horizontal plane by an inclination angle control device (not shown), and rotated in the same direction by a reeler roll drive device (not shown). Also Leela Roll 21
．． 22 are each tilted toward the tube 1 side by the intersection angle T toward the engagement side (inlet side) of the tube 1 which is the pressure-receiving leg by the intersection angle control device 4. When the tube 1 to be reeled is bitten into the reeler rolls 21 and 22, the tube 1 penetrates the reeler plug 3 in the direction of the white arrow shown in FIG. 1, that is, in the direction of the pass line of the tube 1. It moves while moving and is reeled.

Next, using the device as described above, the reeler rolls 21° and 22
A method for controlling the intersection angle will be explained.

The reeler rolls 21 and 22 are each supported by a support device (not shown) at two points: the biting side (inlet side) of the tube 1 and the side (outlet side) of the tube 1. The load applied to the support device or the strain of the support device is measured using a strain gauge 5, and the roll repulsion force a on the entry side (broken line arrow a in Figure 1) and the roll repulsion force b on the exit side (broken line in Figure 1) are determined. Obtain the arrow b) and these ratios a
/b is calculated by the calculator 6.

FIG. 3 is a graph showing the relationship between the ratio a/b of the input side roll repulsion force a and the exit side roll repulsion force S and the contact length of the reeler roll 21, 22 and the reeler plug 3, and the vertical axis is the above-mentioned The contact length and the above ratio a/b are plotted on the horizontal axis. As is clear from the figure, when a/b becomes less than 0.5 and the rolling edge becomes excessive in the direction of the exit side than the reeler plug 3, the reeler roll 21, 22 and the reel plug 3
Since the contact length with the reeler plug 3 becomes smaller,
Reeling is not performed smoothly and reeling efficiency is poor.

On the other hand, a/b becomes 3.0 or more, and Leela Plug 3
If the reduction blade is excessive in the entry side direction, the contact length between the reeler roll 21 and 22 and the love lug 3 becomes small, and the reeling of the pipe l by the reeler plug 3 is not performed in a circular manner, resulting in poor reeling efficiency. . Also, Leela Plug 3
The pipe 1 in the inlet and outlet directions is the reeler roll 21.22
Due to this, the pipe 1 is reduced excessively, and the pipe 1 is greatly deformed, resulting in defective products.

Therefore, is it necessary to control the crossing angle in the reeling process? 111, the ratio a/b of the roll repulsion force a on the inlet side and the roll repulsion force on the outlet side is calculated by the calculator 6 as described above.
If a/b shows a value outside the range of 0.5 or more and 3.0 or less, adjust the reeler roll 21.22 so that a/b is within the range of 0.5 or more and 3.0 or less. The angle of the drive shaft is adjusted by the crossing angle control device 4 to obtain the crossing angle γ.
Optimize and perform reeling. As a result, the contact area between the reeler plug 3 and the tube 1 is maintained above a certain level, and smooth reeling is performed.

[Numerical example]

The rolling control method of the glue roll of the present invention was carried out, and the outer diameter 2
A seamless steel pipe with a diameter of 44.5 mm and a thickness of 11.99 mm was obtained.

Table 1 shows the rolling conditions at that time.

(Leaving space below) Table■ As a result, reeling with a reduction amount Q of 4 mm was performed smoothly, the inside and outside of the steel pipe were polished well, and the reeling efficiency and polishing performance were improved compared to conventional ones. has improved.

〔effect〕

As detailed above, in the reeler roll rolling control method according to the present invention, the roll repulsion force a on the entry side of the reeler roll is
and the roll repulsion force on the exit side of the reeler roll a/
By controlling the intersecting angle so that b is 0.5 or more and 3.0 or less, it is possible to prevent the pipe, which is the object to be rolled, from being rolled down excessively near the entrance and exit sides of the reeler roll. Further, the contact length between the reeler plug and the pipe is maintained at a certain level or more, and reeling of the pipe by the reeler plug is performed smoothly. As described above, according to the method of the present invention, the intersecting angle T can be properly controlled, and the excellent effect of improving the quality of the finished product and the efficiency of the ring can be achieved.

[Brief explanation of drawings]

Figure 1 shows the rolling process t'f11 of the reeler roll according to the present invention.
FIG. 2 is a schematic front view of the apparatus for carrying out the method, and FIG. 3 is a ratio of the input roll repulsion force a to the output roll repulsion force a/ A graph showing the relationship between b and the contact length of the reeler roll and the reeler plug, FIG. 4 is a schematic partially cutaway plan view showing an apparatus for carrying out the conventional rolling control method for the reeler roll, and FIG. 5 is a schematic diagram thereof. The front view, FIG. 6 is a graph showing the distance between rolls in the conventional reeler roll control method when the crossing angle T is not given, and FIG. 7 is a graph showing the distance between the rolls in the conventional reeler roll control method when the crossing angle γ is given. This is a graph showing. l...Tube 21.22...Reeler roll 3...
Reeler plug 4...Cross angle control device 5...Strength end...Calculator a...Inlet side roll repulsion force b...Outlet side roll repulsion force γ...Cross angle patent

Claims (1)

[Scope of Claims] 1. A rolling control method for a reeler roll in which rolling is performed by giving an intersecting angle to the roll axis of the reeler roll, wherein a roll repulsion force a on the entry side of the reeler roll, a roll repulsion force b on the exit side of the reeler roll, and A method for controlling rolling of a reeler roll, characterized in that the crossing angle is controlled so that the ratio a/b is 0.5 or more and 3.0 or less.