JPS5937686B2 - Mandrel circulation device for seamless metal pipe manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus 1 in which a mandrel is recirculated between a press roll perforator i and an elongator in the next process in a seamless metal pipe manufacturing facility.

When manufacturing seamless metal pipes, such as seamless steel pipes, there is a need for equipment that can efficiently manufacture products of excellent quality at low cost.

In order to improve efficiency, there is a method of increasing the speed of the rolling rolls, but this method has reached its limit or requires large equipment.

Therefore, time other than rolling time, that is, operation time, etc., has been shortened. For example, in order to omit the time for removing the mandrel from the pipe, the pipe and mandrel after perforation or rolling can be jumped out of the machine (in one piece) and removed from the machine. A method has been proposed in which the two are separated and during this time drilling or rolling is performed using another mandrel.
In this method, the time for extracting the mandrel can be saved, but the time for setting the mandrel cannot be shortened.

Recently, the press roll perforation method has been put into practical use, and it has become possible to directly perforate inexpensive continuously cast slabs without blooming.

In the press roll drilling method, a polygonal section bloom is inserted from one side (a roughly circular caliber made up of a pair of driven rolls), and a plug attached to the mandrel end is inserted through the other side. This is a method of penetrating a circular pipe (raw pipe) by entering the axial center of the bloom.

Conventionally, in this drilling method, after drilling, the mandrel is retreated and the front end of the pipe is supported by a strip/flange block to remove the mandrel from the pipe. However, in case 1, it remains until the final product.

Further, the force required to pull out the mandrel is large, and the pulling device is large-scale.

Furthermore, air enters the inside of the tube after the mandrel is pulled out, and the inner surface of the tube becomes oxidized.

After drawing the mandrel, the raw tube is sent to the next process, an elongator, where its cross-sectional area is reduced. Conventionally, after the cutting material is jumped out of the machine, the mandrel is advanced and fixed at the rolling position, and then the raw tube is removed. Proceed and start rolling.

In elongator rolling, a set of rolls is arranged around a pass line, with its rotating shaft twisted once in the same direction and driven once in the same direction. Rolling is performed between a plug attached to one end of the mandrel and a roll.

When rolling is completed, the mandrel is pulled out from the raw tube and the raw tube is sent to the next process.

In some cases, the raw tube and mandrel are integrated) After jumping out of the machine, the mandrel is pulled out from the raw tube, and the raw tube is sent to the next process.

Oxidation of the inner surface of the pipe after perforation progresses, and the surface layer of the oxidized layer is partially peeled off by this elongator rolling, or the plug t
Decrease the inner surface roughness of the charred tube.

The oxide layer that grows on the inner surface of the tube similarly deteriorates the inner surface roughness of the tube during the subsequent rolling process, and seizes tools such as plugs and mandrels, reducing their lifespan.

In order to efficiently produce a jointed metal pipe with excellent quality at a low cost, the present invention does not remove the mandrel from the raw pipe even after perforation with a press roll perforator, but rather pulls out the mandrel after rolling with an elongator. The purpose is to send the material back to the press roll perforator and scrape it for reuse, and after the press roll perforator perforates a cylindrical pipe with a polygonal cross-section metal bloom garden or a cylindrical stock pipe, the joint is subsequently rolled with an elongator. In the manufacturing facility for metal-free tubes, there is a conveying device that sends the blank tube with the mandrel still attached after the press roll punching machine 1 completes drilling to the elongator, and the mandrel is attached after the rolling is completed using the elongator 1. The method is comprised of a extracting device for extracting the mandrel from the blank pipe as it is, a feeding device for returning the extracted mandrel to the press roll punching machine, and a straightening device for straightening the mandrel placed halfway through the feeding device. In a seamless metal pipe manufacturing facility where a metal bloom with a polygonal cross section is perforated by one press roll perforator, and then a cylindrical tube with a garden is subsequently rolled by an elongator, after the perforation is completed by one press roll perforator. A conveyance device that sends the raw tube with the mandrel still attached to the elongator, a press device that is provided in the middle of the conveyor device and that advances the mandrel toward the bottom of the raw tube to perforate the raw tube, and an elongator. 1. A extraction device for extracting the mandrel from the raw tube with the mandrel attached after completion of rolling, a feeding device for returning the extracted mandrel to the press roll punching machine, and a device disposed in the middle of the feeding device. It is characterized by comprising a correction device for correcting the mandrel.

As mentioned above, the present invention is applied to a seamless metal pipe manufacturing facility equipped with a press roll perforator and an elongator, and a polygonal cross-section metal bloom is used as the material.

A metal bloom with a polygonal cross section can have a shape that allows the best quality to be obtained by the continuous casting method and is easy to handle.The cross-sectional shape may be a rectangle such as a square or a rectangle, or there may be slight incisions in the corners of these metal blooms. It is desirable that the following modifications have been made.

Although such materials are much cheaper than the circular cross-section blooms used in conventional inclined roll punching machines, they can be made into cylindrical tubes of excellent quality using press roll punching machines.

FIG. 1 shows the layout of a circulation system according to the present invention.

A heating furnace 1 that heats polygonal cross-section metal bloom, which is a raw material, to a temperature suitable for hot processing 1 is connected to a press roll perforator 31 through a bloom conveyance device 2t, and the heated bloom is transferred by the bloom conveyance device 2 to a temperature suitable for hot processing. As shown by B1, the press roll punching machine 31 is sent.

The press roll punching machine 3 used in the present invention is shown in FIG. 2 A showing its cross section and FIG. 2 B1 showing the cross section from A to A in the same figure.
The tip of the plug 5' is positioned inside the caliber to support the mandrel 5 integrated therewith, and the bloom 6 sent from the bloom conveying device 21 is transferred to the roll 4. Due to the forward force caused by the rotation 1 and the pushing force t caused by the pushing device 71, the broom moves toward the mandrel 5 and perforates the axis of the bloom 6, forming a cylindrical blank tube 6'.

The end (bottom) of the cylindrical blank tube 6' is left unperforated or has a plug 5' slightly protruding from it, and such a blank tube 6' is called a cylindrical blank tube with a garden.

Incidentally, it is also possible to form a simple round pipe by perforating the bloom 6 with the press roll perforator 3.

Although the plug 5' can have the tip of the mandrel 5 shaped like a cone or a bullet, it is more advantageous for the purpose of customizing the plug 5' to change the materials of the two and connect them in a screw type.In this case, the plug 5' It is assumed that the diameters of the mandrel 5 and the mandrel 5 are approximately equal.

After the drilling is completed, the latch 8 supporting the mandrel 5 is opened, and the press roll drilling machine 31 is connected to the roller 101 forming the conveying device 9. With the remandrel 5 still attached, the raw pipe 6' is moved in the direction of arrow BM2. It is sent out as shown.

Therefore, the press roll punching machine 3+ is equipped with a device for integrally extracting the raw tube 6' and the mandrel 5.

When the raw pipe 6' and the mandrel 5 are fed out, a new bloom 6 is fed into the press roll punching machine 31 as shown by arrow B1, and a new mandrel 5 is fed and set as shown by arrow M4. Drilling is carried out in a similar manner.

The conveyance device 9 branches into conveyance branch paths 9' and 9'' on the way, and then becomes one again and is connected to the elongator IH.

One conveyance branch path 9'1 is not provided with anything, but the other conveyance branch path 9''1 is provided with a through-hole punching press device 12.
is installed.

This through-boring press device 12 is for penetrating the bottom of a cylindrical tube 6' by inserting a mandrel 5 mounted therein toward the bottom of the tube 6'.

Note that which branch path 1 is to be passed through is determined in advance, and one of the devices can be omitted.

The elongator 11 used in the present invention has a set of two or more rolls 13 twisted in the same direction around a pass line, as shown in FIG. The raw tube 6'1 is rotated and arranged, and is fed by the rollers 10' constituting the conveying device 9 with the bottom or rear end 6'' forward, and the rolls 131 impart a spiral motion to the rolls. 13 and the plug 5' or mandrel 5.

At this time, the plug 5' is connected to the raw pipe 6' at least once on the outlet side.
until it passes a position away from the roll 13, that is, the third
In FIG. 1, the outer end of the mandrel 5 outside the blank tube 6' is continued to be pushed by the pushing device 141 until the plug 5' passes through the line B--B.

By doing this 1, the biting of the raw pipe 6' into the roll 13 is improved, and the vicinity of the rear end of the base pipe 6' or the press roll punching machine 3 is separated from the mandrel 5, which impairs wall thickness reduction. This can be prevented, and the rolling time can be shortened by increasing the forward speed of the raw tube 6'.

It is also possible to continue pushing the mandrel 5 until the end of the raw pipe 6' is completely rolled, but in this case, a mandrel longer than the length of the pipe after rolling is required, which is uneconomical.

When the pushing is stopped at the position where the plug 5' at the front end of the mandrel 5 crosses the B-B line, the raw pipe 6' and the mandrel 5 after rolling are separated.
As shown in the left end of FIG. 5 can be easily removed.

Although FIG. 3 shows the case where the raw pipe 6' has a bottom, in the case of a raw pipe 6' that has been previously drilled with holes, or a raw pipe 6' that has been punched through with a punch press device 12), , with the mandrel 5 end protruding from the bottom penetration part.
This rolling is performed.

Since rolling is performed by the elongator 11 with the mandrel 5 used in the press roll perforator 3 attached, there is no opportunity for air to come into contact with the inner surface of the raw pipe 6' until the rolling is completed.
Almost no oxidized layer is generated on the inner surface of the raw tube 6', and its influence does not occur.

The elongator 111 is connected to the conveying device 15, and the raw tube 6 with the mandrel 5 still attached after rolling is finished.
' is an arrow B from the roller 161 that constitutes the conveyance device 15.
It is sent out as shown by M3.

The elongator 11 is equipped with a device for integrally extracting the raw pipe 6' and the mandrel 5 after rolling.

At one point in the middle of the conveying device 15, a extracting device (I-IJ collar) 17 is installed to extract the mandrel 5 from the raw pipe 6' to which the mandrel 5 is attached after rolling.

An example of this extraction device 17 is one in which the end of the raw pipe 6' is brought into contact with a stripper block, and the protruding end of the mandrel 5 is grasped and extracted.

As means for grasping the protruding end of the mandrel 5, there are a chuck-type method and a method for clamping the protruding end with rolls.

The conveying device 15 has a blank tube conveying device 18 at its tip.
The raw tube 6' after the mandrel 5 has been extracted is sent to the next step, such as a mandrel mill, by the raw tube conveying device 18 as shown by an arrow B4.

The mandrel feeding device 19 is connected to the press roll punching machine 3, and the mandrel 5 is air-cooled or water-cooled to an appropriate temperature on the way and sent back to the press roll punching machine 3 as shown by arrow M4 to be reused.

A straightening device 20 is provided in the middle of the mandrel feeding device 19, and the bending of the mandrel 5 during feeding is corrected.

The straightening device 20t may have a polishing function.

As the straightening device 20, a roll straightening machine that is generally used as a straightening machine for single round bars or circular pipes can be adopted.

Of these, in order to simultaneously straighten and polish the mandrel 5, a so-called i-type straightening machine in which a drum-shaped roll and a drum-shaped roll are opposed is most desirable.

If the mantle 5 is sufficiently straight and has a smooth surface before passing through the straightening device 20, the straightening device 20
It is also possible to widen the distance between the rolls and allow the material to pass through without straightening.

The mandrel feeding device 19 is also provided with an oil lubrication device 21, which applies lubricant to the mandrel 5 after passing through the straightening device 20, if necessary.

Between the straightening device 20 and the oil lubrication device 21 of the mandrel feeding device 19, the unloading device 22 and the loading device 23 are connected. The mandrel is carried out of the circulation system by the carrying-out device 22 as shown by the arrow M5, and a replacement mandrel is carried from the carrying-in device 231 onto the mandrel transport device 19 as shown by the arrow M6.

As described above, the mandrel 5 used in the press roll punching machine 3 is sent to the blank pipe 6') as shown by the arrow BM2 while being attached to the blank pipe 6'), and is selectively moved to the arrow BM2' or the arrow BM2.
” and sent to Elongator 11. Elongator 1
1+ Even after the rolling is completed, the raw tube 6' is taken out as shown by the arrow BM3 while being integrated with the raw tube 6', and the raw tube 6' is removed by the extraction device 11.
After being separated from the mandrel feeding device 191, as shown by arrow M4, the material is corrected along the way and then circulated through the press roll punching machine 31.

Note that the individual devices constituting the present invention are not limited to the first embodiment described above, and can be replaced with other devices that perform the same function.

According to the mandrel circulation device 1 of the present invention, as described above,
Since the same mandrel is used for the press roll perforator and the elongator, there is no opportunity for the inner surface of the raw tube to come into contact with air, which prevents oxidation of the inner surface of the raw tube and prevents simultaneous treading.
The time required to attach and detach the mandrel is also shortened, and since the mandrel is extracted from the tube and straightened for bends while being sent to the press roll punching machine, uneven thickness will not occur even if the mandrel is used repeatedly. Therefore, seamless pipes of excellent quality can be obtained efficiently and at low cost.

Furthermore, Figures 4 and 5 show the cycle times of the press roll perforator and elongator, respectively, and the actual time when one conventional mandrel is continuously used in the same equipment, and based on this, the cycle time of the press roll perforator and the elongator is shown. This is a comparative diagram of the results of trial calculations using the device.

Figure 4 shows a 248ψ copper piece of 215 x 20001 (mm).
This is a case of drilling one cylindrical blank pipe with a diameter of 62 mm and 25501 mm, and the cycle time of the conventional method was 19 mm.
Whereas it takes 5 seconds, the device of the present invention only takes 12.0 seconds.

Figure 5 continues with 248ψX25 tX52801 (m
m) When rolling f
In contrast, the device of the present invention only takes 11.5 seconds.

When viewed through the press roll perforator and the elongator, the cycle time is 20.6 seconds with the conventional device and 12.0 seconds with the device of the present invention, and by adopting the present invention, the cycle time is halved.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the layout of an embodiment based on the present invention 1, Fig. 2A is a sectional view of a press roll punching machine used in the present invention, and Fig. 2B is a line taken along line A-A in Fig. A. Cross section, 3rd
The figure is a sectional view of the elongator used in the present invention, and FIGS. 4 and 5 are diagrams comparing the cycle times of the apparatus of the present invention and the conventional apparatus. In the drawing, 3 is a press roll perforator, 5 is a mandrel, and 6
' is a raw pipe, 9 is a conveying device, 11 is an elongator, 12 is a through-hole press, 17 is a extractor, 19 is a mandrel feeding device, and 20 is a straightening device.

Claims (1)

[Scope of Claims] 1. A seamless metal pipe production facility where a polygonal cross-section metal bloom is perforated with a cylindrical pipe with a garden or a cylindrical pipe with a press roll punching machine, and then subsequently rolled with an elongator. , a conveying device that sends the raw tube with the mandrel still attached after drilling is completed by the press roll punching machine 1 to the elongator, and a conveyor device that transports the raw tube with the mandrel still attached after finishing the rolling by the elongator t. Seamless metal pipe manufacturing equipment comprising: a sampling device for removing the mandrel; a feeding device for returning the extracted mandrel to the press roll punching machine; and a straightening device disposed midway through the feeding device to straighten the mandrel. mandrel circulation device. 2. In a seamless metal pipe manufacturing facility where a metal bloom with a polygonal cross section is perforated by a press roll perforator 1 and then subsequently rolled by an elongator, the mandrel after perforation is completed by a press roll perforator t. a conveyance device that sends the raw tube with the attached tube to the elongator; a press device that inserts a mandrel toward the bottom of the raw tube and perforates the tube through the elongator; - A extraction device for extracting the mandrel from the raw tube 1 with the mandrel still attached after completion of rolling, a feeding device for sending the extracted mandrel back to the press roll punching machine, and a part in the middle of the feeding device. A mandrel circulation device for seamless metal pipe manufacturing equipment, comprising a straightening device for straightening a mandrel arranged in this manner.