DE102020206534A1 - Roll stand with several rolls with integrated temperature measurement technology for determining the rolling stock temperature and correcting the caliber based on the rolling stock temperature - Google Patents

Abstract

The present application relates to a rolling stand (1) for a rolling block in a rolling train for rolling metallic rods, wires or tubes from a rolling stock (28), the rolling stand (1) at least three rollers (3) surrounding a rolling axis (4) in a star shape. which together form a caliber and rotate at a roll speed, the roll stand (1) or a guide (30) attached to the roll stand (1) having a temperature measuring device (29) for determining a surface temperature of the rolling stock (28).

Description

TECHNICAL AREA

The invention relates to a roll stand for a rolling block in a rolling train for rolling metallic rods, wires or tubes from a rolling stock, the roll stand comprising at least three rollers surrounding a rolling axis in a star shape, which together form a pass and rotate at one roller speed. The roll stand can comprise three, four or more rolls.

STATE OF THE ART

Such a roll stand is for example in DE 100 15 340 A1 revealed and also in 1a and 1b shown. Similar roll stands are also described in various documents, for example in DE 10 2007 030 408 A1 or in a slightly different design in EP 3 156 143 A1 . The former relates to a roll stand with three rolls arranged in a star shape around the rolling stock. The second describes a roll stand with four rolls arranged in a star shape around the rolling stock. Both are characterized by the fact that the rollers can be adjusted radially by means of an eccentric in order to make corrections to the caliber and thus to influence the quality and precision of the rolling stock. Each of the rolls can have a separate drive and can be rotatably and radially adjustable in a stand housing by means of a roll shaft and bearings arranged on both sides of the roll. As an alternative to three and four rolls arranged in a star shape around the rolling stock, even more rolls can be arranged around the rolling stock.

In EP 0 921 873 B1 another design of a stand with three rollers is described as an example. Here the rolls are held in movable rockers in the roll stand. With this type of construction, the rolling forces do not remain in the rolling stand, but are diverted into the rolling block via hydraulic cylinders. With this type of stand with three and four rolls, the hydraulic cylinders allow the caliber to be influenced during the rolling process.

All these types of stands with three, four or more rolls have the property that they are independent, quickly exchangeable roll stands, which are accommodated in the rolling block in a stand mount and can be exchanged within a few minutes with newly reconditioned roll stands.

This is necessary to ensure high productivity of the entire rolling train with high product quality. The change of the roll stands is especially necessary when rods or tubes of different diameters are to be rolled. Although it is possible to roll different diameters with the rolling stands described here, the usable adjustment range is limited to only a few millimeters in diameter. If it is desired to roll a significantly different diameter, for example 40 mm instead of 30 mm, it is necessary to equip the roll stands with an appropriately adapted set of rolls.

A rolling block comprises several stand receptacles arranged one behind the other along the rolling axis at roll stand positions, each with a roll stand, the roll stands usually being individually interchangeable in order to enable the aforementioned adjustment of the desired diameter of the rods, wires or tubes to be rolled in a large adjustment range.

For example, eight, twelve or more roll stands are available for a roll block with four roll stand positions, which are operated in a permanent exchange in the roll block.

The roll stands that are not in use are prepared for the next use in the stand workshop.

Most of these roll stands and rolling blocks have in common that the roll stands are equipped with an external adjustment facility for the rolls. The so-called remote setting is done either by an electric motor or by means of a hydraulically operated actuator, such as one or more hydraulic cylinders.

These actuators are able to change the caliber, either directly during rolling or during a rolling break.

It is decided either by the operator or by an automatic system whether there is a correction of the caliber.

It is now state of the art to arrange a measuring device as directly as possible behind the rolling block, with which the geometry and the dimensional accuracy of the rolling stock can be checked. On the basis of these measurement results, corresponding corrections are then carried out on the roll stands by adjusting the roll positions in order to minimize the deviations from the target geometry of the rolling stock.

The disadvantage of this method is that the geometrical deviations are only determined after rolling and that a correction of the material that has already been rolled is no longer possible.

In order for this method to be useful at all, it is necessary that the rolling stock that enters the rolling block has, if possible, no or only very slowly changing properties in its longitudinal direction, which have an influence on the rolling tolerances of the finished product.

Changes in the rolling stock entering the rolling block, such as geometric deviations or fluctuations in the rolling stock temperature, influence the tolerances of the finished rolled stock. If the period of the fluctuations in the longitudinal direction is shorter than the distance between the measuring device and the last roll stand, these fluctuations cannot be corrected with this method.

In the known method, the current state of the art, corrections of the caliber or the rolling speeds are carried out on the basis of the dimensions of the rolled stock that has already been finish-rolled.

It would be advantageous if corrections to the caliber were carried out on the basis of measured values which are already determined during rolling or even before the rolling stock enters the individual stand. It is conceivable that an upstream roll stand shares its measured values and corrections with a downstream stand and thus enables leading control.

The average temperature of the rolling stock below the surface of the rolling stock (referred to in this text as the "average internal temperature") that prevails in the rolling stand during the forming process has a significant influence on the tolerances that can be achieved after the rolling stock has cooled down. Among other things, it is included in the shrinkage equation for the rolling stock, according to which the force required for forming is, within certain limits, inversely proportional to the average internal temperature of the rolling stock.

This average internal temperature of the rolling stock is influenced on the one hand by the temperature of the rolling stock entering the roll stand and on the other hand by the deformation work performed in the roll stand.

The average internal temperature of the rolling stock influences in particular the deformation resistance of the material and the amount of shrinkage after the rolling stock has cooled down. If the average internal temperature of the rolling stock is unknown or if it fluctuates over the length of the rolling stock, the rolling stock will deviate from the desired diameter after cooling.

The average internal temperature of the rolling stock can deviate significantly from the surface temperature. However, since only the surface temperature can be recorded using non-contact optical measurement technology, tolerance deviations occur which can only be checked after the rolled material has cooled down.

In order to obtain the desired diameter after the rolling stock has cooled down, the shaping rollers in the rolling stands are set taking the shrinkage factor into account. For this procedure it is necessary to know exactly the average internal temperature during the rolling process so that the shrinkage behavior of the rolling stock can be precisely predicted by the cooling process in order to achieve the best possible rolling tolerances.

However, since the average internal temperature is not constant over the length of the rolled product due to the process, there is always a geometric deviation over the length of the rolled product.

In order to improve the achievable rolling tolerances, it is advantageous to continuously measure the temperature of the rolling stock and, based on the measured temperature, to change the caliber during the rolling process in such a way that the deviations from the desired geometry are minimized when the rolling stock has cooled down.

On the basis of these measured values, a correction signal is then sent to the rolling block in order to initiate a corresponding correction of the caliber or the roll speeds. However, this method has the disadvantage that on the one hand the actual internal temperature of the rolling stock cannot be used to determine the amount of shrinkage, and on the other hand that the determination of a caliber correction is based on an already rolled piece of the rolling stock. Changes in the temperature of the rolling stock in the longitudinal direction can only be corrected to a very limited extent.

It is also known to install temperature measuring points (pyrometers) at various points in a rolling train, which measure the surface temperature of the rolling stock without contact. Such measuring points are often installed directly in front of a block with several rolling stands in order to determine the temperature of the incoming rolling stock.

However, this method is disadvantageous in that it only determines the surface temperature of the rolling stock and the variable internal temperature as well as the temperature change of the rolling stock, which is due to the deformation work performed in each individual roll stand of the rolling block happens, can not take into account.

For the precise prediction of the shrinkage behavior, however, the average internal temperature of the rolling stock is decisive, which up to now has only been able to be estimated with insufficient accuracy.

DISCLOSURE OF THE INVENTION

The object of the present invention is to eliminate the above-mentioned deficiencies of the prior art and to provide a device of the above technical field which enables smaller tolerances in the rolling of the rolling stock by making use of more suitable information about the rolling stock to be rolled.

This is achieved by a roll stand according to claim 1. Advantageous further developments of the invention emerge from the subclaims and secondary claims.

A roll stand according to the invention in the above technical field is characterized in that the roll stand or a guide attached to the roll stand has a temperature measuring device for determining a surface temperature of the rolling stock. The temperature measuring device is preferably designed for contactless measurement of the surface temperature of the rolling stock. Alternatively, the temperature measuring device can also determine the surface temperature of the rolling stock on the basis of a contact with the rolling stock. The temperature measuring device is preferably a pyrometer, but other temperature measuring devices can also be used, provided they are suitable for determining the surface temperature of the rolling stock.

According to a first advantageous embodiment, the temperature measuring device is integrated directly into the roll stand of a roll block. According to a second advantageous embodiment, it is to be integrated in a guide built on the roll stand of the rolling block before the rolling stock enters the pass or is built onto the roll stand by means of the guide or some other device. The guide can in particular be the inlet guide or inlet roller guide, which is usually provided in the form of rollers or funnels.

This makes it possible, in a rolling block with several, usually four, five or more, one behind the other arranged roll stands, each equipped with such a temperature measuring point, also to take into account the temperature influence of the rolling stock by the forming process.

A preferred rolling stand also has a rolling force measuring device which is designed to determine a current rolling force applied by the rolling stand, the rolling stand further preferably being further designed to provide an average internal temperature of the rolling stock based on the surface temperature determined by the temperature measuring device and the determined rolling force to determine. On the basis of the surface temperature measured value and the rolling force, the average internal temperature of the rolling stock can be determined using a suitable algorithm.

The roll stand is also preferably designed to correct the caliber and / or the roll speed of the rolls in the roll stand on the basis of the average internal temperature of the rolling stock. In this way, the shrinkage behavior of the rolling stock can be compensated for with a high degree of accuracy.

In this way, the measured values can be processed in real time and corresponding corrections to the caliber and / or the roller speed can be initiated. In this way, the desired geometry of the rolling stock is achieved with the highest degree of accuracy in the cold state.

In a preferred rolling block with a plurality of rolling stands arranged one behind the other along the rolling axis, at least one upstream rolling stand and one downstream rolling stand of the rolling block are designed to communicate with one another and / or with a central unit. More preferably, they are designed to communicate with one another in such a way that the surface temperature, rolling force, average internal temperature of the rolling stock determined by the upstream roll stand can be used and preferably used to correct the caliber and / or the roll speed of the downstream roll stand. The roll stands, in particular the control units of the roll stands, can thus form a network and form a much better overall picture of the forming processes taking place in the rolling stock, which enables greater accuracy than with individually determined snapshots of these processes.

Since four, five or more roll stands are usually arranged one behind the other in a rolling block, it is particularly advantageous to use the rolling stock temperatures determined as described above in the front rolling stands in order to carry out caliber corrections in the rolling stands arranged behind them before the rolling stock was rolled.

Furthermore, it is advantageous to integrate the corresponding measurement data processing unit, generally a control device, in addition to the measurement point in each individual roll stand. A measurement data processing unit can, for example, be a freely programmable control which can process the measurement signals and preferably also determine the corresponding corrections to the caliber. If an integrated measurement data processing unit is provided in several, preferably in each roll stand, and these are networked with one another, the measurement data processing units can exchange the measurement data with one another. This makes it possible to react to changes in the temperature and / or geometry of the rolling stock before the rolling stock has passed the respective roll stand.

For such a data exchange, it is also advantageous to make the data transmission wireless and to ensure the power supply for the measurement technology and the measurement data processing unit by means of a rechargeable battery or a contactless inductive current transmission in the rolling block. The battery can be recharged in the scaffolding workshop. A power supply through a separable plug is also conceivable. The latter, however, is not very advantageous, since such connections are very susceptible to failure in the rough operation of a rolling mill.

Figure list

• 1a shows a preferred rolling device in section.
• 1b shows the rolling device 1a in a side view.
• 2 shows a partial sectional view of a part of a preferred rolling device with a temperature measuring device.
• 3 Fig. 13 shows a partial sectional view of part of another preferred rolling device with a temperature measuring device.

WAYS OF CARRYING OUT THE INVENTION

1a shows a roll stand 1 with a scaffolding housing 2 , in which three reels 3 are arranged in a star shape, which is a rolling axis 4th enclose and by their mutual distance or the distance from the central rolling axis 4th define a caliber. Each of the reels 3 has a separate drive 5 , a drive torque for the roller from a drive unit (not shown) 3 is exercised. Via a coupling half 6th , which rotatably on a roller shaft 7th is applied, the torque is applied to the roller 3 transfer.

On either side are the rollers 3 by means of the roller shafts 7th in rolling bearings 13th rotatably mounted. The rolling bearings 13th are located in eccentric sockets 14th and 15th , of which the eccentric bushes 14th on the input side of the rollers 3 are arranged and two rolling bearings 13th own in which the roller shaft 7th is stored, whereas the eccentric bushes 15th on the other side of the reels 3 just a roller bearing 13th have, in which also the roller shaft 7th is stored.

With two of the three roller shafts 7th have the eccentric bushes 15th a bevel gear-like sector gear 16 that is in a tooth segment 16 an eccentric bushing adjacent to the front 14th intervenes.

On one of the end faces of the scaffolding housing 2 is an adjustment device 17th with a rotatably mounted shaft 18th and a bevel gear 19th arranged. The bevel gear 19th engages in a tooth segment 20th one of the eccentric bushes 14th a. At one with the wave 18th non-rotatably connected coupling piece 21 can be a key to turn the shaft 18th , the bevel gear 19th and thus over the tooth segment 20th also the assigned eccentric bushing 14th be attached. Since these - like all eccentric bushings 14th - over one the roller 3 encompassing connecting bracket 22nd with the associated eccentric bush 15th Is rotatably and spaced connected and the tooth segments 16 the rotary movement on the eccentric bushes 14th , 15th of all roller shafts 7th are transmitted, all eccentric bushings 14th , 15th and with it the rollers 3 adjusted synchronously in the radial direction and changed the caliber.

1a and 1b show a disc 23 on the adjustment device 17th , which rotatably with the coupling piece 21 and the wave 18th connected is. On the disk 23 is an in 1b indicated scale 24 attached that along with a pointer 25th the current radial position of the rollers 3 and shows the caliber. A clamping device 26th enables the disc to be locked 23 and thus all eccentric bushings 14th and 15th as well as the rollers 3 in the radial direction so that a caliber can be specified.

Also shows 1b that the coupling half 6th with a toothing 27 is provided, in which a not shown second coupling half of a drive unit can engage.

2 shows part of a preferred rolling device with a roll stand 1 , for example as it is also described in the above 1a is shown. Of the three reels shown there 3 are in the partial sectional view according to 2 only two reels 3 to recognize. The caliber creates a rod-shaped rolled product 28 out, which is rolled by the rolling device.

Before the rolling stock 28 in contact with the rollers 3 comes, ie upstream of the rollers 3 , it gets through an inlet guide 30th passed through which the rolling stock 28 among other things, its alignment around its longitudinal axis can be corrected and fixed. The inlet guide 30th the end 2 is based on a funnel 33 through which the rolling stock 28 is guided to in the caliber between the rollers 3 to get. In the entry guide 30th is a pyrometer 29 arranged as a preferred embodiment of a temperature measuring device. The pyrometer 29 is arranged and designed so that there is a contactless surface temperature of the rolling stock 28 , ie of the staff, can determine. In other words, the surface temperature of the bar is an example of the rolled material 28 through the pyrometer 29 determinable as an example of the temperature measuring device.

3 Fig. 3 shows part of another preferred rolling device with a roll stand 1 , for example as it is also described in the above 1a or 2 is shown. In contrast to the in 2 The rolling device shown is the inlet guide 30th in the in 3 shown rolling device with levers 32 stored

Infeed guide rollers 31 provided and thus forms an infeed roller guide. Also the entry guide 30th the in 3 The rolling device shown serves the purpose of the rod-shaped rolling stock 28 among other things to correct and fix in its alignment around its longitudinal axis.

The in 3 shown inlet guide 30th points a pyrometer 29 on, which is arranged and designed so that there is a contactless surface temperature of the rolling stock 28 , ie of the staff, can determine. In other words, the surface temperature of the bar is an example of the rolled material 28 through the pyrometer 29 determinable as an example of the temperature measuring device.

For example via the adjustment device 17th or with the mechanism for adjusting the positions of the rollers 3 connected devices and elements, it is possible to determine the rolling force by means of a force measuring device that interacts with them. With the information on the surface temperature of the rolling stock and the information on the rolling force, the average internal temperature of the rolling stock can be determined, which can be used for a particularly high-quality rolled product and thus makes it possible to produce a particularly high-quality rolled product using a particularly preferred rolling device.

List of reference symbols

1

Roll stand

2

Scaffolding housing

3

roller

4th

Rolling axis

5

Drive

6th

Coupling half

7th

Roller shaft

13th

roller bearing

14th

Eccentric bushing

15th

Eccentric bushing

16

Tooth segment

17th

Adjusting device

18th

wave

19th

Bevel gear

20th

Tooth segment

21

Coupling piece

22nd

Connecting bracket

23

disc

24

scale

25th

pointer

26th

Clamping device

27

Gearing

28

Rolling stock

29

pyrometer

30th

Inlet guide

31

Infeed guide roller

32

lever

33

funnel

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 10015340 A1 [0002]
• DE 102007030408 A1 [0002]
• EP 3156143 A1 [0002]
• EP 0921873 B1 [0003]

Claims (10)

Roll stand (1) for a rolling block in a rolling train for rolling metallic rods, wires or tubes from a rolling stock (28), the roll stand (1) comprising at least three rollers (3) surrounding a rolling axis (4) in a star shape, which together have a Form caliber and rotate at a roll speed, characterized in that the roll stand (1) or a guide (30) attached to the roll stand (1) has a temperature measuring device (29) for determining a surface temperature of the rolling stock (28). Roll stand (1) after Claim 1 , the temperature measuring device (29) being designed for contactless measurement of the surface temperature of the rolling stock, the temperature measuring device (29) being in particular a pyrometer. Roll stand (1) after Claim 1 or 2 , the temperature measuring device (29) being integrated into the roll stand (1) or attached to the roll stand (1). Roll stand (1) according to one of the preceding claims, wherein the roll stand (1) has a rolling force measuring device which is designed to determine a current rolling force applied by the roll stand (1), wherein the roll stand (1) is preferably further designed to To determine an average internal temperature of the rolling stock (28) based on the surface temperature determined by the temperature measuring device (29) and the determined rolling force. Roll stand (1) after Claim 4 , wherein the roll stand (1) is designed to correct the caliber and / or the roll speed of the rolls (3) in the roll stand (1) on the basis of the average internal temperature of the rolling stock (28). Roll stand (1) according to one of the preceding claims, wherein the roll stand (1) furthermore has a control unit integrated into the roll stand (1) which is designed to process the determined surface temperature and in particular also the determined rolling force in order to determine the caliber and / or to correct the roller speed. Roll stand (1) according to one of the preceding claims, wherein the roll stand has a rechargeable battery for supplying the temperature measuring device (29), the rolling force measuring device and / or the control unit with electricity. Roll stand (1) according to one of the preceding claims, wherein the roll stand (1) can communicate via a wireless connection with a central unit and / or a further roll stand (1), in particular by means of the control unit. Rolling block with several roll stands (1) arranged one behind the other along the roll axis (4) according to one of the preceding claims, wherein at least one roll stand (1) arranged upstream and one roll stand (1) arranged downstream of the roll block are designed to work together and / or with a Central unit to communicate, in particular to use the surface temperature, rolling force and / or average internal temperature of the rolling stock (28) determined by the upstream roll stand (1) to correct the caliber and / or the roll speed of the downstream roll stand (1). Method for correcting a pass in a roll stand (1) according to Claim 4 or one of Claim 4 The dependent claim, comprising determining a surface temperature of the rolling stock (28), determining a rolling force applied by the roll stand (1), determining an average internal temperature of the rolling stock (28) and correcting the caliber and / or the roll speed on the basis of the average indoor temperature.

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