DE3335942A1 - METHOD AND DEVICE FOR RETURNING THE PINS OF A PLUG ROLLING MILL FOR PRODUCING SEAMLESS TUBES - Google Patents

Description

Method and device for returning the mandrels of a plug rolling mill for the production of seamless tubes

The present invention relates to a method for returning the mandrels of an axially guided mandrel bars Rolling mill, which is used in particular for the production of seamless tubes.

The present invention also relates to a device to use the above procedure

In a rolling mill that works with mandrel bars, one becomes longitudinal drilled and clamped on a mandrel blank passed through a large number of uprights, wherein during this passage the mandrel is "supported" by a suitable holding device equipped with its own drive will. At the end of a rolling process, the mandrel withdrawn from the respective tube, which is also referred to as the mandrel bar can be returned by this device to its starting position located in front of the first stand frame, from where he goes through the stand framework again.

It is known that in the manufacture of seamless tubes in a rolling mill of the type described above, there is a surface finish of the mandrel and the optimally designed lubrication and temperature conditions are very important to. It is also known that the mandrel returned to its starting position after the end of a rolling process is subjected to a whole series of operations in order to prepare it accordingly for the next rolling process.

-3-

33942

The time required to perform these operations is not extremely long, but in any case longer than that Throughput time of the pipe to be produced. About the rolling mill performance better to use and, in terms of their surface properties, Having optimally equipped mandrels available for lubrication and temperature became the actual rolling mill a so-called mandrel circuit is connected upstream, all of them one after the other includes necessary stations for processing the mandrels and in which about four to five mandrels are in circulation. In this way there is always a ready-to-use mandrel available at the entrance to the rolling mill, which actually means better rolling mill utilization causes.

According to the current state of the art, the is returned to its starting position after the end of a rolling process The mandrel removed immediately so that a new mandrel can be attached just as quickly in this position, the one from the rolling mill on The farthest end is then fastened in the holding device.

Between the free end of this dome and the entrance to the rolling mill a free space is created to accommodate the rolled blank. This results between two successive rolling processes a dead time during which the holding device takes its position at a distance from the rolling mill entrance, the is greater than the length described by the mandrel plus blank (approx. 30 - 35 m); also takes place during this dead time Removing the used mandrel, positioning a new mandrel and the blank, and inserting the mandrel in this blank.

The main purpose of the present invention is to provide a method and the corresponding devices for returning the mandrels to provide a rolling mill of the type mentioned, with the help of which in the prior art between

-4-

· - '' · - ■ ~ ^{vJ r}

two successive rolling processes occurring dead times can be significantly reduced.

This task and other tasks explained in more detail below are achieved by a method for returning the mandrels according to the invention in that in a first method section in a laterally from the actual rolling axis Area, a new or reconditioned mandrel is introduced into a corresponding, longitudinally drilled out rolling blank is, while in a second process section this mandrel together with the applied rolling blank in a predetermined, in front of the rolling mill located at the height of the rolling axis position is implemented, with the removal of a used one at the same time Dornes takes place from this very position, in which he after completion of the previous rolling process has arrived.

Further features and advantages associated therewith emerge from the following description of a method according to the invention Return of the mandrels, in which reference is made to the accompanying drawings, in which an embodiment the devices for the practical application of said method is shown. Show it:

1 shows the schematic representation of a device for using the method according to the invention for recycling the thorn,

FIG. 2 shows the schematic representation of an individual part from FIG. 1 on an enlarged scale,

3 shows, on an even further enlarged scale, the section through a converter as it is in the device of FIG. 1 and 2 is used and

FIG. 4 shows the view of this converter from FIG. 3.

-5-

In the figures, the multitude of stand stands of a rolling mill working with a supported mandrel for the production of seamless tubes designated as a whole with 1, these stand frames being arranged along a horizontally extending rolling axis A. are. A mandrel 2 is in the working position between the plurality of upright frames 1 in exact alignment with the aforementioned Axis A shown. A rolled blank is applied to the mandrel 2, but this is for the sake of clarity of the drawing is not shown.

The end of the dome 2 is fastened in a clamping head 4 executed in a known manner, which is at the end of a toothed rack 5 is attached, which in turn runs along the rolling axis A and by a plurality of driven gears 6 is operated. The gears 6, the rack 5 and the clamping head 4 form a mandrel holder, with the help of which the rolling blank fed to the rolling mill and the mandrel supported during the rolling process and after completion of the rolling process from the Rolling mill is returned.

Of course, the mandrel holder described here only represents a preferred exemplary embodiment according to the invention and can, depending on the technical requirements and availability, by any, according to the state of the art Executed holding device are replaced.

After completion of the rolling process, the tube 8 just produced is removed with the aid of a plurality of peeling stands designated 7 (Release rollers) separated from the mandrel 2, which is then returned to its original position by the mandrel holder 4, 5 and 6 as shown in FIG. In this starting position, the mandrel 2 is supported by a plurality of rollers 9 (Fig. 2) supported, which are arranged along the rolling axis A in front of the rolling mill. As with the prior art, are these rollers 9 sunk attached so that the movements

Q Q ~ for α / ο

6 ο O ο · _; <J it £ _

the rack 5 and the clamping head 4 along the rolling axis A cannot be hindered.

To the side of the plurality of rollers 9, a roller conveyor 10 extends parallel to the rolling axis A, while between the rolling axis A and the mentioned rollers 9 a plurality of converters 11 is provided.

3 and 4, a preferred, but non-binding embodiment of one of these converters 11 is shown.

On a driven shaft 12 which is parallel to the rolling axis A runs, a crank 13 with two arms 14 and 15 is applied, from the free ends of which via corresponding bearings 16 and 17 a freely rotatable pin 18 is received. on this pin 18 is a rod-shaped between the arms 14 and 15 trained holder 19 arranged vertically, the upper end 20 of which is shaped like a cradle and dimensioned so that there is a Can accommodate thorn. A gearwheel is also driven onto the pin 18, which is rotatable about a pin 23 in the arm the crank 13 arranged gear 22 is in engagement. This gear 22 in turn engages in a ring-shaped one Rack 24 .ein, which is mounted on a holder 25 and the driven shaft 12 rotates coaxially. Based on the description and it is clear from the illustration that as soon as the shaft 12 is set in motion, the rod-shaped one Holder 19 while maintaining its vertical position about the axis of said shaft 12 at a distance therefrom which is determined by the length of the crank 13. The rod-shaped holder 19 is otherwise with a Counterweight 26 is provided, which is either formed as part of the crank 13 or attached as an individual part to the crank 13, always eccentric to the axis of the driven shaft

The roller conveyor 10 is continued up to a station 27, in

-7-

Q - ο Γ, Q / 9

which the mandrels are implemented for cooling, with the help of not shown, since on quite conventional Type, for example as lever works, executed relocating devices. Similar devices then do the relocation of the cooled mandrels from the station 27 onto a roller conveyor 28, which is parallel to the rolling axis A on the one opposite to the roller conveyor 10 Side runs.

The roller conveyor 28 is extended by a chain conveyor 29, which is optionally through an induction furnace 30 and then can be passed through a lubrication station 31, preferably designed as a cabin with suitable dimensions, those with the necessary devices for spraying the surface-improving Products must be provided on the mandrels passing through.

At the exit from the lubrication station 31 there is a chain conveyor 32, likewise running parallel to the rolling axis A Extension of the aforementioned chain conveyor 29 is provided. The chain conveyor 32 is then driven by a roller conveyor 33 extended, which ends in the vicinity of the zone 34 in which the already bored blanks 35 to be rolled arrive.

Between the roller conveyor 33 and the plurality of rollers 9 is a path 36 for introducing a mandrel into a drilled one Blank 35 is provided. This path consists in its first section of a chain part designated 37 and in its second section of a designated 38 roller part. The chain part 37 is known per se and is consequently not shown Devices for holding and advancing a mandrel guided in them equipped.

A "buffer" 39 is attached between the roller conveyor 33 and the track 36, in which in the event of interruptions in the rolling process or the process in the "mandrel circulation" forming, the

Stations upstream of the rolling mill, which can then remain on the accruing mandrels. Of course, this buffer can be bypassed as soon as a fast run-through of the mandrels is to be carried out.

Between the roller conveyor 33, the buffer 39 and the infeed track 33 converters are provided, which, depending on requirements, collect the incoming mandrels or do a fast run the thorns allow. Further relocators of the type shown in Figures 3 and 4 are between the web 36 for insertion of the mandrels and the plurality of recessed mounted rollers 9 are provided.

By means of the devices described above, this becomes the following further explained method according to the invention can be used.

During the rolling process, a mandrel 2 is driven from the Rack 5 and the clamping head 4 existing mandrel holder out. A second mandrel 2A lies on the roller conveyor 10, while another pair of mandrels 2B, 2C are in the station 27 is located. Another mandrel 2D passes through the lubrication station 31 at this point, while finally another Mandrel 2E from the chain part 37 of the infeed track 36 into one on the roller part 38 of the infeed track 36 immediately in front of the rolling mill provided, drilled out rolling blank 35 is advanced.

After the end of the rolling process, the used mandrel 2 is returned to its starting position by the mandrel bar holder 4, 5, 6, where it is supported by the plurality of rollers 9. From this position, the mandrel 2 is directly on the Roller conveyor 10 implemented. At the same time, the mandrel, which has already been introduced into the rolled blank 35, is placed on the released rollers 9 2E positioned. The end of this mandrel 2E is automatically fitted into the clamping head 4. Immediately after clamping the rack 5 is actuated by the gears 6. Another rolling process is initiated.

τ ■ "τ- ς η / 9 vj.,: ■ J ο ι \ L

During the rolling process, the mandrel 2D, which is the greasing station 31 has passed / transferred to the infeed belt 36, during which it cooled to a temperature of approx. 110-120 ° C The mandrel 2C is possibly passed through the induction furnace 30 and then through the lubrication station 31. In the meantime the used mandrel 2 is cooled while it is dwell on the roller conveyor 10 under the action of the room air, whereby out and again a control of the surface quality and the Straightness of the mandrel axis is carried out. During this check, the mandrel 2 is deemed to be unsuitable for a new rolling process found, it is separated out, for example, at an intermediate station 40, while a new mandrel from a mandrel magazine 41 is introduced into the mandrel circulation.

At the end of the roller conveyor 10, the mandrel 2 has completed the first cooling phase under room air and is operated with water Cooling station 27 initiated.

The previous introduction of the dome into a rolling blank while the rolling process is running offers the undeniable advantage of a considerable reduction in dead times between two successive rolling processes.

The time required to move a used mandrel from its starting position to the roller belt 10 and for the simultaneous positioning of one already in the rolled blank The mandrel introduced at the entrance to the rolling mill is much shorter than the time that is currently required technology is required to remove a used mandrel from the rolling line in order to create a new mandrel and a rolling blank to position in front of the rolling mill, insert the mandrel into the rolling blank and then the rolling mill with the unit To load the mandrel blank. In addition, the dead time is again reduced by the fact that the "return" of the clamping head according to the method according to the invention compared to the current one

-10-

Prior art can be done more quickly because the length dimension resulting from the length of the mandrel plus the drilled blank no longer has to be taken into account.

ΛΑ

Blank page

Claims (2)

Expectations Process for returning the mandrels of a rolling mill working with supported mandrel bars for the production of seamless pipes, characterized by a first process section in which in a side of the actual roll axis (A) area a new or reconditioned mandrel in a longitudinal axis drilled out Rolling blank (35) is introduced, and through a second process stage in which this mandrel together with the rolling blank in a predetermined before the rolling mill is implemented at the level of the rolling axis position, while at the same time the used mandrel is removed from this position in which it has come after completion of the previous rolling process. 2. Device for performing the method according to claim 1, characterized by arranged parallel to the rolling axis (A) Receiving devices (36, 37, 38) for at least one mandrel (2E) which can be introduced into the blank (35) and by means of transfer devices (11), with which the mandrel or mandrels from the receiving devices to their position on the rolling axis (A) can be translated. ■ <-