JPS58167006A - Method for exchanging mandrel bar in seamless steel pipe hot rolling mill - Google Patents

Abstract

PURPOSE:To eliminate loss time caused by the exchange of a mandrel bar, and to improve the efficiency of seamless steel pipe rolling, by transferring a hollow blank pipe, into which the mandrel bar is previously inserted at the side of a pass line, to the pass line, and rolling it. CONSTITUTION:A mandrel bar 7 conveyed in the direction of an arrow (a) by a conveying device (figure is eliminated) such as a chain is inserted into a hollow blank pipe 6 fed onto the conveying line M1-M1, and the blank pipe 6 is transferred in the direction of an arrow (c) onto a pass line P-P of a rolling-starting position 2. Next, the blank pipe 6 is fed to a rolling mill 1 after holding the mandrel bar 7 by a mandrel bar holding device 3. After finishing the rolling of the pipe 6, the bar 7 is retreated to the rolling-starting position 2 and is transferred in the direction of the arrow (c) to the 2nd conveying line M2-M2, and then the bar 7 is conveyed in the direction of an arrow (b) by rolls, etc. and further, is transferred in the direction of an arrow (d) to be cooled by a cooling device 4, and is conveyed on the conveying line M1-M1 in the direction of the arrow (a) to be coated with a lubricant by a lubricating device 5, then the mandrel bar stands ready for the insertion to the next hollow blank pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention describes hot rolling of jointless steel pipes, and a method for replacing a mandrel rolling mill with parr restraint type.

A mandrel bar is applied to a hollow blank tube that is formed into a thick hollow wall using a par-restricted type mandrel rolling machine or a punching machine, or a hollow blank tube that has been further stretched (by another rolling machine). Insert and over 116~? By installing stands 2
A hollow tube is continuously rolled between a mandrel bar and rolls using a 5-meter rolling mill to achieve the required pipe dimensions. After rolling, the mandrel bar is retreated to cool the tube. Then, a lubricant is applied to the tube and the tube is inserted into the next hollow tube.

One of the conventional mandrel bar changing methods in such a par-restricted mandrel rolling mill is to use one mandrel bar continuously. In this mandrel bar replacement method, when the hollow wooden tube is fed into the rolling start position, a mandrel bar is inserted from behind and sent into the rolling mill with a pusher. When the hollow wood tube passes the t-end roll of the rolling mill, the mandrel bar is replaced. During this time, the mandrel lever is cooled and when the next hollow wooden tube is sent to the rolling start position, the mandrel parlor is moved forward and inserted into the hollow blank tube.

However, in this method of replacing the mandrel bar, the first rolling is performed before the high temperature mandrel bar can be cooled down sufficiently, which increases the temperature of the mandrel bar surface and significantly shortens its life. Frequently, scratches occurred on the inner surface of the hollow wood pipe due to surface damage, etc. Also, when applying lubricant while the mandrel bar is moving forward, the time required for the hollow wood pipe to enter the roll of the rolling mill is However, the lubricant did not harden sufficiently, and as a result, the lubricating effect could not be achieved. It is possible to delay the start, but
If this is done, the rolling interval becomes long, production efficiency decreases, and production volume inevitably decreases significantly.

In order to solve these problems, Japanese Patent Application Laid-Open No. 53-589
A method of replacing a mandrel bar as shown in Japanese Patent No. 353 has been proposed. This method uses multiple mandrel bars, and when the rolling of the hollow tube is finished, the mandrel bars are moved back to the rolling start position, and then sent out from this position in a perpendicular direction to separately provided cooling equipment and lubricant application equipment. transport. On the other hand, the mandrel bar that has passed through the cooling equipment and lubricant application equipment is kept on standby on the pass line, and when the next hollow shell tube is sent to the rolling start position, this mandrel bar is advanced and inserted into the hollow shell tube. It is a round product that is fed into a rolling mill using a pusher.

As is well known, the production efficiency of mandrel girdle depends on the time from when a hollow shell tube is fed into a rolling mill until when the next hollow shell tube is fed into a rolling mill, that is, the positive arc interval. The conventional method described above involves carrying the hollow shell to the rolling start position, inserting the mandrel bar, feeding the paper into the rolling mill with a pusher and rolling, pulling out the mandrel bar, and carrying the mandrel bar out in the lateral direction. The series of working hours is a major factor in determining rolling intervals. According to this exchange method, the cooling time and the time from applying lubricant to rolling are certainly extended, and on the other hand, it is possible to eliminate the waiting time for the mandrel bar, but it takes a long time to carry the mandrel bar to the rolling start position. (For example, 10 to 15 fI@) Since the mandrel bar must be inserted into the hollow tube, a lot of time is required for this rounding, and there is still a large amount of lost time.

In particular, now that the rolling speed of the mandrel rolling mill and the perforating machine that is its maker 1 has increased significantly, the above-mentioned loss time appears to be a major obstacle to the rolling process. This has become a serious issue.

This invention was made to solve the above-mentioned conventional problems, and its target is the insertion of a mandrel bar into a medium-sized 9-piece pipe! Is it possible to completely eliminate loss time? To provide a method for replacing a mandrel bar in a single-unit steel pipe rolling mill that can provide sufficient cooling time and hardening time for lubricant.

A method for replacing a mandrel bar in a seamless copper tube hot rolling machine according to the present invention is a rounding method that achieves the first objective above, after inserting a mandrel bar into a hollow shell on one side of the pass line, and then passing the pass line. h) The mandrel bar carried out from the pass line is rolled by cooling equipment and lubricated. After passing through the cooling equipment and lubrication equipment, the mandrel bar is sequentially delivered to a position where it can be inserted into the hollow shell tube.

The figure is a layout diagram of rounding according to an embodiment of the present invention. 1
2 shows the mandrel rolling machine, 2 its inlet cheeple, P-P the pass line of the mandrel rolling machine, 5 the mandrel bar restraint device, 4 companies' cooling equipment, and 5 the lubrication equipment. 6 is a hollow tube, and 7 is a mandrel bar. M, -M are the mandrel bar 〇纂1 conveyor lines installed parallel to the pass line P-P 10,000@, and the mandrel bar 7an, t
The material is transported in the direction of the arrow by a transporting device (not shown) such as a holder. --M is a conveyance line of the iris 2 of nine mandrel bars installed on the other side of the pass line P-P in parallel thereto, and the mandrel bar 7 is connected to a conveyance device (not shown) such as a roller by K. 1.6. It is transported in the direction of the arrow. −.

Now, when the hollow tube 6, which has been perforated by the artist, is transported onto the first transport lines M, -M1 by the walking beam electrified transport device (not shown), the transport device The mandrel bar 7, which is being fed in the direction of arrow a, is inserted into the hollow tube 6. The six hollow tubes into which the mandrel bar 7 has been inserted are sent by a conveying device in the direction of the papermaking arrow, that is, in a direction perpendicular to the path twin P-P, and are stopped at a pressure level of gti brass on the pass line P-P. At this time, the mandrel bar
The restraining device 6 moves forward to restrain the tail end of the mandrel bar 7, and the mandrel bar 7 is fed into the mandrel rolling mill 1 by a pusher (not shown).

When the hollow shell 6 is rolled and its rear end passes the final roll, the mandrel bar 7 is moved back to the rolling start position, and the restraint of the mandrel bar (-7) by the restraint device 6 is released.

Next, the mandrel bar 7 is conveyed by the conveyance device in the direction of the arrow [phase] (direction perpendicular to the pass line P-P), and is conveyed in the direction of the arrow by the second conveyance lines M, -M. It is then stopped at the position , and then transported in the direction of arrow d by, for example, a walking beam electrostatic transport device (not shown), during which time it is cooled by the cooling equipment 4 . The cooled mandrel bar 7 is sent onto the first conveying line M, -M, and sent to the lubrication equipment 5 to be coated with lubricant.
It is sent out in the direction of arrow a by the first conveyance line M1-M.

On the other hand, when the mandrel bar 7 that has finished rolling is sent out from the rolling start position to the second conveyance line Mt-Ml, the first
On the conveyor lines M, -M, the next hollow blank tube 6 into which another mandrel bar 7 is inserted is sent to the rolling start position,
After the tail end of the mandrel bar 7 is restrained by a restraint device 6, it is sent to the mandrel rolling mill 1.

The above steps can be summarized as follows.

(1) Insert the mandrel (-) into the hollow tube on the side of the pass line.

■ Feed the hollow tube with the mandrel bar inserted into the sline.

(6) The mandrel bar is restrained and rolled using a mandrel rolling mill.

(4) Retract the mandrel bar after rolling.

6) Send the mandrel bar to the side from the pass line.

(6) The mandrel bar sent out from the pass line is sent to a cooling facility and cooled.

(7) Send the cooled mandrel bar to the lubrication equipment and apply handle lubricant.

(8) Send the mandrel bar sprinkled with lubricant to a position where it can be inserted into the hollow wood pipe.

As is clear from the above description, according to the present invention, the next hollow wood pipe mandrel bar is inserted during rolling of the hollow receiving pipe, and the retracted mandrel bar is carried out in any direction after the rolling is completed. At the same time, the next hollow wood pipe into which the mandrel bar has been inserted is fed onto the pass lie/top and rolling can begin immediately. The time for inserting the mandrel bar into the two blank tubes is not included in the cycle time at all, and the rolling interval can be shortened by this amount of time. Moreover, since sufficient time for cooling and curing of the lubricant can be taken, the rolling interval can be greatly shortened not only in the first conventional example but also in the second conventional example, and physiological efficiency can be improved. .

In the above embodiment, a mandrel bar is inserted into the hollow tube on one side of the pass line, and the tube is carried into the pass line.
Although the case has been described in which the mandrel bar is moved backward and carried out to the other side after rolling, the present invention is not limited to this. The mandrel bar may be conveyed to the pass line, and the mandrel bar may be released from the restraint at the rolling end position and the mandrel bar may be moved forward, or the mandrel bar may be moved back and the restraint released at the end of rolling.
It may be carried out again to the insertion side from above the pass line or below the channel. The present invention is characterized in that the mandrel bar is inserted into the hollow tube in advance at any point along the pass line.

In the above 0 @ Akira, the mandrel bar-O circulation Kll
Although we have shown a case in which lubricant is applied to the mandrel bar by installing lubricating equipment, this is not essential for Hiromoto loosening.
May be omitted. If necessary, a preheating device may be provided in the circulation path of the mandrel bar. Furthermore, although the above embodiment shows the case where the present invention is implemented in a mandrel rolling mill, there are many other rolling mills in which the present invention can be implemented.

As detailed above, one false INK twists and the pressure threshold distance is increased.
K-san and Cao, and what's more! Since sufficient time is allowed for the cooling of the dropper and the hardening of the lubricant, the mold efficiency is improved and the amount of raw mold can be greatly increased, so the effects of implementation are extremely large.

[Brief explanation of drawings]

The figure is a rounding arrangement diagram for explaining the invention in detail. 1: Mandrel rolling machine, 5: Restraint device, 4: Cooling equipment,
5: 1lff equipment, 6: Hollow pipe, 7: Beak drill par. Agent Patent Attorney Masato Sato

Claims (1)

[Claims] A mandrel bar is attached to the hollow tube on one side of the pass line.
A method for replacing a mandrel bar in a heat threshold rolling mill for SUI steelless tubes, characterized in that the mandrel bar is inserted into the pass line, the mandrel bar is restrained, and a 1lleφ air tube is rolled.