JPS5890304A - Method and apparatus for cold rolling pipe, especially, extremely long pipe - Google Patents

Abstract

1. Process for the cold rolling of pipes (2), particularly of large lengths, on a rolling mill with a reciprocating roll stand and positively driven grooved rolls (1) located therein, with intermittent advance and/or rotation of the pipe in the region of one or both dead centres (ET, AT), whereby the alternate rotation, possibly with total angle of rotation added from one or more individual angles of rotation, is equally great for each direction of rotation, characterized in that in a buffer zone deflecting the pipe (2) from the direction of rolling, the cyclically irregular speed of the rolled out pipe is converted into a constant run-out speed at which the pipe (2) is withdrawn, whereby the distance between the run out chuck (3) and the driving apparatus (4) is proportioned such that the torsional stress of the rolled pipe (2) always lies in the elastic range.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that the direction of each rotation is adjusted so that at least one rotation is the same in all angles consisting of a plurality of unit rotation angles, and nine alternate rotations have the same magnitude. or a rolling machine equipped with a roll stand that moves back and forth once while giving intermittent feed and/or rotation to the pipe in the region of both dead centers, and a forcibly driven caliber roll for rolling pipes, especially very long ones. The present invention relates to a method for cold rolling pipes and an apparatus for carrying out the method.

When rolling pipes in stepwise rolling machines, especially cold pilger mills, for economic reasons the attempt is made to constantly increase the length of the pipe to be rolled. This means that the ingot is produced by cold rolling, drawing, or continuous drawing. 4 applies in the case of the production of copper pipes. In these methods, it is important to use heavy ingots and ingots from the viewpoint of cost efficiency, and it is required to roll the ingots to a distance of 250 meters measured from the back of the cold rolling equipment. There is.

With the currently commonly used cold rolling process, problems arise when the rolled pipe is finished rolled at cyclically different speeds, even for lengths of about 90 meters.

The acceleration acting on the pipe exceeds the IOC. In this case, the acceleration force must be received and supported by the frictional force between the fixed chuck on the exit side, the piezoelectric material, and the cold rolling tool.
The pipe moves forward in the rolling direction without being controlled during the luck stage. That is, the required feed in the pipe is 4
I have to be seen. The problems described above are amplified when the pipe vibrates along its length due to periodic acceleration pulses, making the pipe thus treated obsolete.

Another problem that arises when cold rolling very long pipes is that one dead center or one dead center gives rise to rotational acceleration at both dead centers, giving rise to rotational acceleration of the pipe < m1, resulting in one-turn vibration. , it becomes difficult to guide the pipe to the outlet side trough, noise is generated, and the holding moment acting on the fixing chuck of the cold piezoelectric device becomes large.

Therefore, the object of the present invention is to eliminate the above-mentioned gambling disadvantages associated with the conventional cold rolling method, and to reduce the acceleration forces generated in the longitudinal direction of the pipe as well as around the axis of the pipe, thereby reducing the pressure It is an object of this invention to allow only a relatively short portion of the entire length of the pipe to be affected by longitudinal and rotational accelerations, thereby making it possible to economically manufacture much longer pipes.

To achieve the above objective, the periodically non-uniform velocity of the rolled pipe is converted into a constant exit velocity in the buffer region which deflects the pipe from the rolling direction, thus the periodically non-uniform velocity of the pipe According to the invention, a method has been proposed, characterized in that the velocity is adjusted to reduce to zero in the buffer area and/or in an adjacent area.

According to a further preferred aspect of the invention, it is proposed to concentrically wrap the pubs in an area following the buffer area.

The work cycle is [The pipe is rotated in an angle range of 45° to 90°, but in normal cases,
It is known that the rotations are made in the same direction. However, it is also known to rotate the pipe by alternating the direction of one revolution. However, as a result of rolling tests, each direction of rotation is rotated only once or rotated in multiple stages.

It has been shown that if the partial rotation angles are the same or differ only slightly, it is not possible to keep the tolerances of the pipe within a satisfactory range. Furthermore, it is proposed according to another preferred embodiment of the invention that for each direction of rotation K, the unit rotation angles differ from each other by at least 20'.

It is known to wind up pipes in rolling mills (
(see German Patent No. 2,747,767).

However, when using the configuration of this known invention.

The purpose of the present invention is to achieve the intended purpose of secondary treatment of the pipe, which is to avoid subjecting the pipe to longitudinal and rotational acceleration over a large portion of the length of the knob. Can not.

According to the invention, an apparatus Fi for implementing the above-described inventive method:
A drive device operating at a constant speed is positioned at a predetermined distance from the compression area, and at this location the stresses in the pipe are adjusted so as not to exceed the yield point of the pipe.

The holding moment of the driving device and the holding moment of the fixed chuck of the rolling device are adjusted so as to be larger than the torsion moment, so that the above-mentioned distance does not flatten the uneven rolling speed that appears periodically and functions as a buffer area. It is characterized by being set. As a result of the rolling test, when rotating the pipe by a total of 90 degrees in each direction of rotation, the above distance (the length of the pipe is 2
It is clear that a range of about 40 to 50 meters is preferable (up to 50 meters).

A stationary device constructed so that it does not rotate around the pipe, and placed at nine strategic locations at a predetermined distance behind the rolling mill, converts the periodic non-uniform velocity of the pipe into a uniform transfer velocity. According to the present invention, a companion device is also proposed which is constructed so as to be able to convert the pipe into a vertical axis and to suppress the rotation of the pipe behind this device by Z af/C. The roller of this device can steplessly adjust the driving state according to the rolling speed of the cage or the formation state of the cage in the buffer area, and can also pull out the rolled pipe end. It is advantageous to provide a drive.

Another aspect of the invention is that the drive device is configured as a bending device for winding the pipe.

According to the invention, as an alternative, behind the rolling mill -
A device may also be provided.

1. According to the present invention, a reel having a constant circumferential speed is provided.

The reel has a tune formed by the device and is adjusted to give a uniform speed to the coil.

Alternatives to the zero-bending device and reel are proposed to be adjusted so that f) a K-drive coiler or a drum tensioner may be used.

Converting the rotational speed to a non-uniform longitudinal velocity without rotating the pipe"Another configuration is possible in the longitudinal direction K.
A holding and bending device that can be freely moved but prevents the pipe from rotating is placed at a predetermined distance from the deformation area to flatten the longitudinal velocity of the pipe. According to the invention, it is proposed to carry out this process at the final winding stage of the coil. According to this construction, the pipe is deflected from the central plane of the roll before the holding device, and the pushing force through the holding device is obtained from the rolling process. The advantage of this embodiment is that the pipe is guided in a straight line and that the speed can be adjusted relatively easily. However, the disadvantage is that this method can only be used if it is possible for the cross-sectional area of the rolled pipe to bear the pressure forces generated on the pipe without interfering with the rolling process.

According to the invention, the length of the eve behind the buffer region is dynamically uncoupled from the eave mass beyond which the eve can be rotated. This is advantageous because it allows the mass of the main part of the roll to be transferred at a constant speed and does not cause any hindrance to the rolling process.Furthermore, according to the present invention,
In addition to being able to transport pipes easily and safely, the pipes can be easily sawed, marked, inspected and straightened.The invention allows pipes to be wound into coils. By cooling, the length of factory equipment can be significantly reduced.

The present invention will now be described in detail with reference to the accompanying drawings, which illustrate one embodiment of the present invention.

A roll is designated by the reference numeral 1 and is adapted to move in a known manner while rotating between an entrance dead center ET and an exit dead center AT. The pipe 2 is rotated alternately in both rotational directions in a known manner, but in order to obtain a high-quality pipe and to reduce wear on the rolls, the total rotation angle is at least 90°, and each rotation angle is at least 90°. Preferably, the pipe is rotated in two unit steps of 35 degrees and the angular difference between each rotation step is adjusted to be at least 4120 degrees. The exit side fixed chuck 3Fi cooperates with the inlet side fixed chuck (not shown) to rotate the above rotation angle pipe 2 at both dead centers ET and one before AT.

Subsequently, the pipe 2Fi deviates from the rolling surface behind the straight exit section with a length of approximately 30 meters.
It is guided through a deflection section of approximately 70° with a radius of curvature of approximately 15 meters through a drive 4 driven at an average rolling speed. The driving device 411t is configured to be able to support the twisting moment of the pipe 2 generated in the outlet side fixed chuck 3 as the pipe rotates. The transport speed of the drive 4 is adjusted according to the radius of curvature of the drive. After leaving the pipe 2Fi drive 4, it is led to a bending roller unit 5, which does not carry out a bending roller unit 5Fi drive.

The bending roller unit 5Fi arrives and forms the pipe 2 into a coil 6 at a constant speed without giving any rotation to the pipe 2, and the coil 6 is wound onto the reel 7, but the circumferential speed of the coil on the reel 7 is It is adjusted to match the transport speed of the drive device 4. The circumference of the pipe is guided through a curved guide closed on three sides in the drive, and the end of the pipe is quickly pulled out by the drive after exiting the deformation area of the Taji device and wound onto a reel. It will be done. The reel is replaced before the new pipe is put on the reel. .

[Brief explanation of drawings]

The accompanying drawings are schematic diagrams conceptually illustrating the structure of an apparatus according to an embodiment of the present invention. 1...Roll, 2......ノ<4
7'. 3...Fixed chuck on the exit side. 4... Drive device, 5... Curved roller unit. 6...Coil% 7...Take-up reel.

Claims (8)

[Claims] (1) For each direction of rotation K, the alternating rotations are adjusted to have the same magnitude over the entire angle consisting of one or more unit rotation angles, while the front Intermittent feed/''
A method for cold rolling a pipe with a rolling machine equipped with a roll stand that moves back and forth while applying rotation, and a caliber roll that is forcibly driven, and a very long pipe, The periodically non-uniform velocity of the rolled pipe is converted into a constant exit velocity in a buffer area that deflects the pipe from the piezoelectric direction, and the pipe is pulled out at this constant exit velocity, which causes the rotation of the pipe. The pipe is held in place between the buffer area and the rolling area at a predetermined distance from the rolling area, where the torsional stress is adjusted so that it does not exceed the yield point of the pipe. How to characterize it. (2) The method according to claim 1, characterized in that the pipe is wound up in an N-stone shape in an area following the two buffer areas. (3) The method according to claim H, characterized in that the unit rotation angles differ from each other by at least 20° for each direction of rotation. (4)! An apparatus for carrying out the method according to claim 1, wherein a drive device 4 operated at a constant speed is disposed at a suitable location a predetermined distance away from the rolling area,
At this position, the torsional stress in pipe 2
It is adjusted so as not to exceed the yield point of the pipe, and the holding moment of the fixed chuck 3 on the exit side of the rolling machine l and the holding moment of the driving device 4 are adjusted so as to be larger than the threading moment based on the rotation of the pipe. Apparatus characterized in that said distance is set to act as a buffer region to even out periodic non-uniform piezoelectric velocities. (5) The ninth point where the drive device 4 winds up the pipe 2 is the device 5.
5. The device according to claim 4, characterized in that it is configured as: (6) In order to wind up the pipe 2, the device 5 drives the drive device 4.
5. Device according to claim 4, characterized in that the device is arranged in series behind the device. (7) A reel 7 rotating at a constant speed is arranged behind the bending device 5 (a coil 6 arranged in series, and a uniform speed corresponding to the transfer speed of the drive device 4 is formed on the 9-luer).
Device according to any one of the claims 4 to 6, characterized in that the device is adapted to provide a. (8) An apparatus for carrying out the method according to claim 1, wherein the holding device for preventing the pipe from rotating and the bending devices 4 and 5 are placed at a predetermined distance from the deformation processing area. This spacing ensures that torsional stresses are absorbed and that the velocity of the pipe is reduced along the length of the pipe during the final coil winding stage. A device characterized in that it is designed to flatten the surface.