DE102006054383B4 - Method, apparatus and their use for pulling or braking a metallic material - Google Patents

Abstract

Method for operating a device (1) for pulling or braking a metallic good (2) in a removal direction (L), the device (1) having at least one pulling device (3) and the at least one pulling device (3) having a magnetic pulling force can exert on the metallic good (2), characterized in that the distance (a) of the metallic good (2) is measured relative to a desired position (S) and the position (b) of the at least one pulling device (3) perpendicular to the pull-off direction ( L) is regulated relative to the metallic good (2) in such a way that the metallic good (2) remains in its target position (S) as far as possible.

Description

The invention relates to a method for operating a device for pulling or braking a metallic material in a take-off direction, wherein the device has at least one pulling device and wherein the at least one pulling device can exert a magnetic pull-off force on the metallic material. Furthermore, the invention relates to a device and its use for pulling or braking a metallic Guts.

The assembly and disassembly of strip tension is essential for the operation of strip processing equipment. Depending on the corresponding process stages, an adapted, defined train is of great importance for the optimum quality of the product produced. This leads to the need to repeatedly set up and remove tape tension in the course of passing the tape as it passes through the treatment plant. Exemplary is the directional tape run through the system, the increase of the strip tension for devices for stretching and straightening in flatness defects, the tempering (adjusting the metallurgical properties of the material used) and the drawdown in the annealing furnace called.

From the WO 97/02103 A1 a device for braking electrically conductive tape is known, in which the tape is further processed under tension having a magnetic field generating device. This generates an alternating magnetic field, which induces eddy currents in the band, which exert a directed against the conveying direction of the belt force on this. It is provided that the magnetic field generating means comprises a rotatable magnet roller, which is aligned transversely to the conveying direction of the tape and having on its peripheral surface arranged in alternating sequence magnetic poles of different polarity. The direction of rotation of the magnet roller is opposite to the conveying direction of the belt.

From the EP 1 054 743 B1 For example, there is known an apparatus for pulling or braking metal bands, the band being disposed between endless circulating chain systems that clamp the band with carriage-like roller blocks. It is further provided there that each roller block carries its own elastic coating that can be tailored by shaping and filling pieces. Furthermore, it can be provided that magnetic coils or permanent magnets are arranged on the roller blocks.

In a very similar way, the EP 1 350 576 B1 Such a device with endless circulating chain systems of carriage-like roller blocks that take the tape, the roller blocks carry magnets to produce a linear strip tension by means of eddy current. Again, permanent magnets or solenoids can be provided.

The DE 101 15 389 A1 shows a device for drawing or braking metal strip in process lines between two oppositely arranged, sprocket-driven, endlessly circulating carriage chain systems. Again, roller blocks are equipped with permanent magnets or with electric coils to produce a magnetic force that brakes or pulls the belt.

The DE-AS 1 288 865 shows a similar solution in which permanent magnets or electromagnets are used.

The DE 23 01 434 A describes a tape drawing apparatus in which the tape tension is generated by a traveling magnetic field by means of stationary inducers. In training of which sees the WO 2005/035158 A1 a traction device for non-contact application of the tape tension, wherein between two synchronously running upper and lower magnetic traveling wave fields, a phase shift is introduced and controlled so that a central hovering of the belt is achieved.

The well-known use of rotating permanent magnets and electromagnets - especially when they are on chains and thus act as driving caterpillars - are mainly used in non-ferrous metallurgy (metallurgy of non-ferrous metals), for example, for copper and aluminum.

The magnetically applied volume force for building up and reducing strip tension is proportional to the product of the electrical conductivity of the strip, the square of the magnetic induction field strength of the magnets at the location of the strip and the slip (the speed difference) between the strip and the rotational speed of the magnets magnetic field (in the traveling field). In the case of nonferrous metallurgy, the very good electrical conductivity, for example of aluminum and copper, is of great importance, which is why the tensile or braking force generation here is relatively high. On the other hand, the force exerted by the magnet force comes about by eddy currents in the band, which acts repulsive for the tape and thus self-centering.

The problem is the pulling or braking of a tape with the prior art devices, if this z. B. steel and thus consists of a ferromagnetic material. In addition to the inferior to non-ferrous metals such as aluminum and copper electrical conductivity of Steel is here the ferromagnetic attraction of the steel as massively disturbing added.

While the above discussed solutions give good results in the case of conveying non-ferrous metal strips, this is not true for ferromagnetic material strips. If the tensile force is built up by the eddy currents in a band of non-ferrous metal, they act, as mentioned, repulsive on the continuous band, so that there is a certain self-centering of the band between the traction devices. However, this effect is limited to non-ferrous metal strips.

If, however, bands of ferromagnetic material (in particular steel bands) are to be conveyed, the attractive effect between band and magnetic traction device dominates due to ferromagnetism over the repelling effect, so that the band can not be stably guided by the conveying device. It can be roughly said that the ferromagnetic attraction effect is greater by a factor of 100 than the repulsive effect due to the eddy currents.

At the time of the EP 1 350 576 B1 and from the EP 1 054 743 B1 known solution to the brake or scaffolding in the crawler solution only consist of half in the form of a transfer table and should achieve by a desired Bandanziehung that a tensile torque is transmitted to the belt. For better replacement of the ferromagnetic strip from the circulating conveyor belt, the rotating magnetic tape has a protective belt there.

In case of WO 97/02103 A1 The permanent magnets are located on a rotating drum, which counteracts the effect of - unwanted - ferromagnetic attraction by an outer protective sheath, which moves independently of the rotating magnetic drum and runs synchronously to the belt speed.

The band can lean against this protective cover and suffers no damage. However, this arrangement is correspondingly complex, and it must be feared that in continuous operation process-related difficulties arise (lubrication).

In the other, above-mentioned prior art, the problem of pulling or braking ferromagnetic material is not discussed at all.

The invention is in the light of the above problems the object of the invention to provide a method and associated apparatus for pulling or braking a metallic Guts, in particular of ferromagnetic material, or overcomes the difficulties mentioned and improved pulling or braking Guts, in particular a belt, allows to take without complex measures to stabilize the belt between the traction devices despite the ferromagnetic attraction effect. It is to ensure a stable promotion of the band through the device, even if the good has ferromagnetic properties.

This object is achieved by the method according to the invention in that the distance of the metallic Guts measured relative to a desired position and the position of at least one pulling device is controlled perpendicular to the withdrawal direction relative to the metallic Good so that the metallic material remains as possible in its desired position.

After that, therefore, the distance of the traction device is controlled by the deducted good that the good itself remains in its desired position. If there is a ferromagnetic, unidirectional tensile force between one of the traction devices and the good that wants to deflect it from its desired position, so the pulling device is removed or removed from the estate, so that the ferromagnetic tightening force decreases, and the good returns to its desired position ,

A further development provides that at least one pulling device is used, which has a carrier element for magnets, wherein the magnetic withdrawal force takes place by circulation of the carrier element and wherein a part of the carrier element passes through the metallic material parallel to its surface plane. Furthermore, it can be provided that the magnetic pull-off force is generated by permanent magnets or by electromagnets which are arranged along the carrier element. Preferably, a carrier element is used in the manner of a crawler.

Thus, in the event that the traction device is removed from the estate, which would basically decrease the magnetic withdrawal force in the withdrawal direction, a very constant withdrawal force is maintained, provides a development that the rotational speed of the support member in dependence of the distance of the magnets of the metallic It is well regulated that a largely constant magnetic pull-off force is applied to the metallic material. As can be seen from the above relationship, the slip is then increased to the extent that the distance between the magnets increases from the good and the force acting on the good induction field strength decreases, so that overall the withdrawal force remains at least substantially constant.

The device for pulling or braking a metallic material has at least one Pulling device, wherein the at least one pulling device can exert a magnetic pull-off force on the metallic good by means of magnets. According to the invention, means of movement are provided with which the at least one pulling device can be moved perpendicularly to the withdrawal direction, and that measuring means are provided with which the distance of the metallic good from a desired position can be measured, wherein the moving means and the measuring means via control means are arranged in a closed loop.

The measuring means are preferably designed for non-contact measurement of the distance of the metallic material from the desired position. This can be a laser measuring device, a capacitive measuring device or an inductive measuring device.

Between the magnet and the metallic material, a separating plate made of a non-abrasive material, preferably a ceramic plate, can be arranged to protect the material. Since it comes to a possible tape touch to friction effects (= heat), ceramic plates are preferred over, for example, separating plates made of hardwood or plastic, because they can tolerate heat effects better.

When forming the support element in the manner of a crawler, the drive of the support element is preferably equipped with at least one electric motor, wherein it can be provided in particular that the electric motor has a low rotational moment of inertia to quickly speed changes of the support element can accomplish. For this purpose, known pencil-shaped pencil motors have proven themselves. In this case, the electric motor may have a stationary core and a rotating enclosure.

The proposed arrangement has proven particularly useful when pulling or braking of good ferromagnetic material, although it can also be used for non-ferrous metals. The material is particularly preferably a steel strip.

Further features and details of the invention will become apparent from the claims and the description of an embodiment of the invention shown in the drawing.

The single figure shows schematically a device for pulling or braking a metal strip, which in the present case consists of ferromagnetic material.

The device 1 for pulling or braking the metallic material 2 in the form of a steel strip has two pulling devices 3 on - it may of course also be braking devices that the band 2 do not pull but brake -, where ever a pulling device 3 above and below the band 2 is arranged. The illustration in the figure shows the band 2 and the pulling devices 3 on average; the ribbon 2 and the devices 3 extend flat in the plane that emerges vertically from the plane of the drawing.

Every pulling device 3 is designed in the manner of a caterpillar track. A carrier element 4 is band-shaped and is about wheels 10 guided. The wheels 10 turn from electric motors 9 driven so that the carrier element 4 has a circulation speed v. At the periphery of the support element 4 (Carrier tape) are present permanent magnets 5 arranged. Over the area along which the magnets 5 parallel to the plane of the band 2 drive, they generate a withdrawal force in the withdrawal direction L due to the above-mentioned relationship.

The goal is, in spite of ferromagnetism, between magnets 5 and band 2 exists and tries the tape 2 to the magnets 5 to draw, as far as stable promotion of the tape 2 to achieve that this remains possible in its desired position S, that of the symmetrical center between the traction devices 3 equivalent. For this purpose, the procedure according to the invention is as follows:
It is envisaged that the distance a of the band 2 measured relative to a desired position S and the position b of the at least one pulling device 3 perpendicular to the withdrawal direction L relative to the metallic good 2 so regulated that the metallic good 2 remains as possible in its desired position S. These are means of movement 6 provided, which are shown only schematically and serve to the entire traction device 3 perpendicular to the withdrawal direction L to move away or back to the tape 2 : approaching. Furthermore, measuring means 7 present the distance a between the band 2 and its target position S measure. This distance a should be as zero as possible; then that is the band 2 in the ideal position. However, this will not always be the case during operation. Will the band 2 deflected and consequently a value for a not equal to zero from the measuring means 7 measured, controls a control means 8th the means of movement 6 and pulls in the position of the tape shown in the figure 2 the upper pulling device upwards away, so that the magnetic attraction between band 2 and magnets 5 decreases and the band 2 causes it to return to its desired position S. In this case, therefore, the distance b between the traction device 3 and an upper stationary wall, thereby reducing the distance c between the belt 2 and the magnet 5 increased accordingly.

Thus the pull-off force between the magnets 5 and the band 2 In the withdrawal direction L nevertheless remains as constant as possible, drive the electric motors of the upper take-off device 3 the carrier element 4 with magnets 5 faster, ie the circulation speed v increases. This will also cause the slip between the magnets 5 and the band 2 larger, which keeps the withdrawal force constant despite decreasing induction field strength of the magnets.

This will also be good when pulling or braking 2 Made of ferromagnetic material possible to ensure a stable delivery process, the required equipment required is limited.

An immediate contact between the band 2 and the magnet 5 the pulling device 3 is prevented by separating plates, not shown, preferably ceramic plates.

Also not shown are means of movement, a approach and a departure of the traction devices 3 to the band 2 or from this way to allow maintenance or repair work.

The attraction force on the band associated with the induction field strength 2 As explained in the introduction, this method also has a strong effect on this method as a result of the ferromagnetic material, which however can be controlled by the proposed invention.

The traction devices 3 should be as close to the tape as possible 2 to be placed. To protect the continuous belt 2 before touching the magnets 5 the mentioned additional partition plates are provided. These are similar to the sliding blocks known from pickling lines to avoid scratches on the strip surface during strip contact.

For maintenance and repair of the system, the arrangement of the traction devices 3 be formed so that opening and closing around the band 2 is possible. For this purpose, not shown moving means are provided.

The detection of the tape in its position relative to the desired position S thus takes place without contact with the measuring means 7 , wherein preferably, but not exclusively, a laser, a capacitive or an inductive sensor can be used.

The entire pulling device 3 gets off the line fast 2 moved so that the attraction force on the band with the induction field weakening is restored or increases. The regulation must be done depending on the page (top or bottom band). While in the figure only moving the traction device 3 is provided up or down, the entire traction device can be pivoted controlled about an axis that is normal on the drawing plane.

Simultaneously with the enlarged or reduced distance, the induction field strength at the strip position and thus the propulsion force goes back to the tensile structure or it rises. To compensate for this effect, the slip between the orbital velocity v of the magnets must 5 and the band 2 to be changed. The consequence of this is a mass reduction for the circulation system and a reduction of the rotational moments of inertia. In order to change the speeds quickly, you need motors with a low rotational moment of inertia. Preferred engines are long drawn and have a small diameter; they are known as pencil motors. In the embodiment, motors are used, which have a stationary core, wherein the outer casing rotates (exchange of rotor and stator). The motors must be operated in the main current connection.

The system is started up in such a way that the circulation stand, d, h. the traction devices 3 once off the line 2 stand away. The carrier elements 4 with the magnets 5 Run according to the belt speed and have only once a small difference in speed. The two pulling devices 3 will now join the band 2 moved up and the regulation for the position of the traction devices 3 activated. The rotational speed of the traction devices 3 is now increased, so that builds a strip.

The departure process is the same as the start-up procedure; it only takes place in the reverse order.

In the figure, the structure of a strip tension is shown in the horizontal direction. Of course, according to a Bandzugaufbau also possible in the vertical direction.

Both for the movement of the traction devices 3 through the moving means 6 as well as for the change of the speeds of the electric motors 9 Very fast control processes are required to ensure a stable process.

LIST OF REFERENCE NUMBERS

1

Device for pulling or braking

2

metallic good

3

hitch

4

support element

5

magnet

6

means

7

measuring Equipment

8th

control means

9

electric motor

10

wheel

L

withdrawal direction

S

target position

a

distance

b

distance

c

distance

v

velocity of circulation

Claims (16)

Method for operating a device ( 1 ) for pulling or braking a metallic material ( 2 ) in a take-off direction (L), wherein the device ( 1 ) at least one pulling device ( 3 ) and wherein the at least one pulling device ( 3 ) a magnetic pull-off force on the metallic material ( 2 ), characterized in that the distance (a) of the metallic material ( 2 ) relative to a desired position (S) and the position (b) of the at least one pulling device ( 3 ) perpendicular to the withdrawal direction (L) relative to the metallic good ( 2 ) is regulated so that the metallic good ( 2 ) remains as possible in its desired position (S). Method according to claim 1, characterized in that at least one pulling device ( 3 ), which is a carrier element ( 4 ) for magnets ( 5 ), wherein the magnetic pull-off force by circulation of the carrier element ( 4 ) and wherein a part of the carrier element ( 4 ) the metallic good ( 2 ) happens parallel to its surface plane. A method according to claim 2, characterized in that the magnetic withdrawal force by permanent magnets ( 5 ) is generated along the support element ( 4 ) are arranged. A method according to claim 2, characterized in that the magnetic pull-off force by electromagnets ( 5 ) is generated along the support element ( 4 ) are arranged. Method according to one of claims 2 to 4, characterized in that a carrier element ( 4 ) is used, which is formed in the manner of a caterpillar track. Method according to one of claims 2 to 5, characterized in that the rotational speed (v) of the carrier element ( 4 ) as a function of the distance (c) of the magnets ( 5 ) of the metallic good ( 2 ) is regulated so that the metallic good ( 2 ) a substantially constant magnetic withdrawal force is applied. Contraption ( 1 ) for pulling or braking a metallic material ( 2 ) in a take-off direction (L), wherein the device ( 1 ) at least one pulling device ( 3 ) and wherein the at least one pulling device ( 3 ) by means of magnets ( 5 ) a magnetic pull-off force on the metallic material ( 2 ) for carrying out the method according to claim 1, characterized in that movement means ( 6 ) are present, with which the at least one pulling device ( 3 ) can be moved perpendicular to the withdrawal direction (L), and that measuring means ( 7 ) are present, with which the distance (a) of the metallic material ( 2 ) can be measured from a desired position (S), wherein the movement means ( 6 ) and the measuring means ( 7 ) via control means ( 8th ) are arranged in a closed loop. Apparatus according to claim 7, characterized in that the measuring means ( 7 ) for non-contact measurement of the distance (a) of the metallic material ( 2 ) are formed by the target position (S). Apparatus according to claim 8, characterized in that the measuring means ( 7 ) are a laser measuring device, a capacitive measuring device or an inductive measuring device. Device according to one of claims 7 to 9, characterized in that between the magnets ( 5 ) and the metallic good ( 2 ) is arranged a partition plate made of a non-abrasive material. Device according to one of claims 7 to 10, characterized in that when forming a carrier element ( 4 ) for the magnets ( 5 ) in the manner of a crawler, the drive of the support element ( 4 ) with at least one electric motor ( 9 ) he follows. Apparatus according to claim 11, characterized in that the electric motor ( 9 ) has a low rotational moment of inertia. Apparatus according to claim 12, characterized in that the electric motor ( 9 ) is a pencil motor. Device according to one of claims 11 to 13, characterized in that the electric motor ( 9 ) has a stationary core and a rotating enclosure. Use of the device according to one of claims 7 to 14 for removing metallic material ( 2 ) in the form of a ferromagnetic material. Use according to claim 15, characterized in that the ferromagnetic material is a steel strip.

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