EP2408593B1 - Method and device for grinding a continuous casting product - Google Patents

Description

The invention relates to a method for grinding a continuous casting product, in particular a slab, wherein the continuous cast product in cross section has a rectangular contour with two opposite long sides and two opposite short sides, wherein at least the long sides are subjected to surface treatment by means of at least one grinding tool. Furthermore, the invention relates to a device for grinding a continuous casting product.

Continuously cast products, in particular slabs, are subjected to surface finishing by grinding after continuous casting in order to achieve a sufficient quality in the further processing of the product. In the case of continuous casting slabs, the slab is usually reciprocated in the longitudinal direction in a reversing motion under a grinding device (grinding aggregate). At the end of each reversing movement, the grinder performs a stepwise cross-feed motion until the entire slab surface is ground.

During grinding, the slab is stored on a grinding table lying on its long broad side.

A generic prior art apparatus for grinding slabs is in Fig. 1 shown. It is similar to the one in the EP 0 053 274 A1 is described.

On the in Fig. 1 sketched device, the so-called. HP grinding (high-pressure grinding) of the slab 1 is performed. The device has a grinding table 13 and a grinding device 9 with drive motor 10 and grinding wheel 6. The slab 1 has in a known manner two long sides 2 and 3 (broad sides) and two short sides 4 and 5 (narrow sides). It lies with one of its long side 3 on the grinding table 13. When grinding the top of the slab, the grinding table 13 reversibly moves under the grinding device 9 in the direction perpendicular to the plane of the drawing. In this case, the grinding wheel 6 is pressed by means of a grinding pressure cylinder 14 against the upper side of the slab 1. The slab 1 is thus moved by means of the grinding table 13 relative to the grinding device 9 in the longitudinal direction back and forth. With each reversing the grinding device 9 performs by means of a feed cylinder 15 a stepwise cross-feed movement until the top of the slab is finished ground.

The disadvantage is that the slab 1 has a minimum area moment of inertia in its position with the broad side on the grinding table 13 about an axis which is horizontal and transverse to the slab longitudinal axis. Accordingly, the resistance to bending about this axis is minimal. In particular, when grinding a slab with a high temperature (eg up to 800 ° C) there is a risk of sagging. Therefore, the grinding table 13 is provided at defined intervals along the longitudinal axis of the slab 1 with supports 16, which are intended to minimize the bending of the slab. The number of copies 16 is selected to be correspondingly high. However, this disadvantageously results in a relatively robust and heavy construction of the grinding table.

Slabs with average temperatures (in the range of for example 450 ° C) bend due to the higher temperatures at its lower horizontal main side at the slab ends up. This leads disadvantageously to the fact that the slab in the illustrated positioning during grinding tends to undesirable vibrations during grinding. The slab 1 lies in this case, especially on the middle supports 13.

Even slab-cooled slabs are therefore generally not nearly flat with respect to their broadsides.

Another problem is that it can lead to significant caking of grinding chips on the device, if the flight of chips during grinding is not optimally maintained. Therefore, in prior art solutions, a relatively high maintenance effort is required to keep the device in optimal condition of use.

The invention is therefore based on the object to provide a method and an associated device, with which or with which it is possible to achieve in a relatively lightweight construction, that the deflection of the continuous casting product, in particular the slabs is minimized. This should also optimize the quality of the grinding process. Furthermore, it should be achieved that the grinding of the continuous casting product can be carried out in an efficient and rapid manner, so that the grinding can be carried out economically. Furthermore, the aim is to design the method or the device such that a removal of the grinding chips can take place in an improved manner. As a result, in particular caking chips are to be reduced to the device.

The solution of this object by the invention is characterized in that when controlling a long side of the continuous casting product, the continuous casting product is positioned by means of a receptacle such that the surface normal to the long side of the continuous casting product with the vertical includes an acute angle greater than zero degrees ,

The angle between the surface normal and the vertical is preferably between 30 ° and 90 °. One embodiment provides an angle between 40 ° and 75 °. A preferred embodiment provides that the angle between the surface normal and the vertical is 90 ° ("vertically arranged slab").

A refinement provides that both a long side and a short side are ground by means of the at least one grinding tool in one layer of the continuous casting product on the receptacle. This eliminates a separate grinding unit for grinding the short or narrow side.

In "vertically arranged slab" can be provided in a particularly advantageous manner that the two opposite long sides of the continuous casting product are simultaneously ground by means of at least two grinding tools. The continuous casting product can be positioned by means of a receptacle in the form of a holding frame during grinding in a hanging manner.

The long side of the continuous casting product is usually at least twice as long as the short side, often even more than twice as long.

The proposed apparatus for grinding a continuous casting product has at least one grinding device with at least one grinding tool for grinding at least one long side of the continuous casting product and is characterized in that the device comprises a receptacle designed to position the continuous casting product during grinding in such a way in that the surface normal to the long side of the continuous cast product with the vertical includes an acute angle greater than zero degrees, preferably an angle between 30 ° and 90 °.

The apparatus may also comprise two grinding devices, each having at least one grinding tool, which are designed and provided for the simultaneous processing of the two opposite long sides of the continuous casting product.

The intake for the continuous casting product may have a contact surface for a long side of the continuous casting product and a contact surface for a short side of the continuous casting product.

Optionally, the receptacle comprises a holding frame with which the continuous casting product can be positioned in a hanging manner.

The invention is based on the recognition that the area moment of inertia of the continuous casting product, in particular the slab, increases by a horizontal transverse axis and thus the resistance to deflections when the continuous casting product is inclined in the longitudinal direction on its narrow side. By reducing the necessary requirements on the grinding table, therefore, the weight of the grinding table can be reduced in an advantageous manner.

In the oblique arrangement of the continuous casting product during grinding, the chip flight is also steered more directly than in the horizontal storage in the chip collection box, d. H. optimized. The risk of caking is thus reduced. The chip collection box can therefore be made smaller advantageously. So it comes in an advantageous manner to a targeted flurse-side oriented flying sparks and thus the use of a simpler chip collection box.

In order to reduce the design effort for the device and in particular for the grinding table and the chip collecting box, so the increase of the area moment of inertia of the continuous casting product is desired during grinding, which can be achieved with said approach or embodiment of the invention.

Accordingly, the deflections of the continuous casting product are lower than in the case of previously known solutions.

If, when grinding hall temperature up to high temperatures, the grinding is carried out according to the invention obliquely employed slab, the slab is due to their high weight on their respective narrow side at a certain angle whose preferred range is given, so that only a few editions required are.

Another advantage of the proposed solution, especially at higher slab temperatures, is that the broad sides of the slab can be inspected directly from close to the side.

Fig. 1

eine Vorrichtung zum Schleifen eines Stranggussprodukts in Form einer Bramme gemäß dem Stand der Technik;

Fig. 2

schematisch eine Vorrichtung zum Schleifen eines Stranggussprodukts in Form einer Bramme gemäß einer ersten Ausführungsform der Erfindung;

Fig. 3

eine Vorrichtung zum Schleifen eines Stranggussprodukts in Form einer Bramme gemäß einer zweiten Ausführungsform der Erfindung;

Fig. 4

die Vorrichtung gemäß Fig. 2 bei einer erweiterten Verfahrensweise gemäß der Erfindung;

Fig. 5

schematisch eine Vorrichtung zum Schleifen eines Stranggussprodukts in Form einer Bramme gemäß einer dritten Ausführungsform der Erfindung; und

Fig. 6

eine Vorrichtung zum Schleifen eines Stranggussprodukts in Form einer Bramme gemäß einer vierten Ausführungsform der Erfindung.

In the drawings, embodiments of the invention are shown. Show it:

Fig. 1

a device for grinding a continuous casting product in the form of a slab according to the prior art;

Fig. 2

schematically a device for grinding a continuous casting product in the form of a slab according to a first embodiment of the invention;

Fig. 3

a device for grinding a continuous casting product in the form of a slab according to a second embodiment of the invention;

Fig. 4

the device according to Fig. 2 in an extended procedure according to the invention;

Fig. 5

schematically a device for grinding a continuous casting product in the form of a slab according to a third embodiment of the invention; and

Fig. 6

a device for grinding a continuous casting product in the form of a slab according to a fourth embodiment of the invention.

In Fig. 2 schematically a device for grinding a slab 1 is shown, which operates according to the invention. The slab 1 has a rectangular cross-section which is in Fig. 2 you can see; the slab 1 extends with its longitudinal axis in the direction perpendicular to the plane of the drawing. The slab 1 accordingly has two long sides 2 and 3 and two short sides 4 and 5. The long sides 2, 3 are usually at least twice as long as the short sides 4, 5, usually much longer.

The slab surface must be processed by means of a grinding process in order finally to be able to produce a product of sufficient quality from the slab by means of a subsequent rolling process. For this purpose, a Schleifvorrichtüng is provided by the in Fig. 2 only the grinding wheel 6 is sketched. The arrow indicates the direction of rotation of the grinding wheel 6 during its operation.

In order to increase the area moment of inertia about a horizontal axis extending transversely to the longitudinal direction of the slab and consequently to minimize the bending of the slab 1 during grinding, it is provided that during grinding of the upper long side 2 (the same applies after turning the slab during grinding) lower long side 3) of the slab 1 is positioned by means of a receptacle 7 such that the surface normal 8 on the long side 2 of the slab 1 with the vertical V (ie seen in the direction of gravity) forms an acute angle α. This angle is greater than zero degrees. It is preferably 30 ° or more.

In this position, the known grinding process is performed, d. H. the grinding table 13 oscillates in the direction of the longitudinal axis of the slab 1 (thus in the direction perpendicular to the drawing plane) back and forth, while the grinding wheel 6 at each stroke or double stroke of the grinding table 13 a certain amount transversely to the width direction of the slab 1 is continued.

For holding the slab 1, the receptacle 7 in the present case has a contact surface 11, consisting of mutually spaced struts, for the long side 3 and a contact surface 12 for the short side 4.

The direction of rotation of the grinding wheel 6 causes the grinding chips to be discharged down the inclined slab surface and guided into a chip collecting box below the device. Chip breakage is indicated by the reference number 18 indicated by the dashed line. As can be seen, a baffle 19 may be provided to affect the chip clearance 18.

The slab 1 thus processed may be a hot slab. Due to their higher temperature, the proposal according to the invention comes into its own, as here the bending of the slab is a particularly relevant topic.

A concrete embodiment of a device for grinding a slab 1, in which the various devices are shown, in the schematic representation according to Fig. 2 have been omitted is the Fig. 3 refer to. In principle, the same thing applies here, too Fig. 2 was said. The slab 1 is here, however, employed a little further obliquely, than at Fig. 2 the case is. Here, the surface normal 8 with the direction of the vertical V encloses an angle α which is about 75 °.

It can be seen that the grinding device 9 has a drive motor 10 for the grinding wheel 6 with which it is driven. The grinding wheel 6 is delivered or pressed in the processing of the slab 1 by a grinding pressure cylinder 14 normal to the slab surface. The stepwise movement of the grinding wheel 6 over the width of the long side 2 of the slab 1 is accomplished by a feed cylinder 15. Below the device, a chip collecting box 17 is arranged.

In Fig. 4 is a variation of the solution according to Fig. 2 to see.

Mostly both the long side of the slab and the short side are ground. In this case, usually two separate grinding devices are used. The long side is ground with a powerful main unit. For the short side, an auxiliary unit with lower power can be installed.

By extending the function of the main unit, the possibility can be created to also grind the short side with the main unit. This is in Fig. 4 illustrated.

The grinding wheel 6 is sketched here in two different positions. In the lower position, the grinding of the long side 2 of the slab is as in Fig. 2 explained. However, after grinding the long side 2, the grinding wheel 6 is also guided over the upper short side 5 in order to grind it in the illustrated positioning of the slab 1 on the receptacle 7. This is indicated by the upper layer of the grinding wheel 6. In order for the grinding chips to be able to be conducted downwards into the chip collection box (not shown) in this case, it is provided for the grinding of the short side 5 that the direction of rotation of the grinding wheel 6 is changed (see arrows). To guide the chips baffles 19 are also provided here.

The main unit is modified so that both the grinding of the long side and the grinding of the short side is possible. On a separate accessory can thus be dispensed with. For this purpose, both directions of movement of the grinding unit must be equipped with a grinding pressure control.

The concept proposed according to the invention also includes an arrangement of the slab 1 during grinding, so that the angle between the surface normal 8 on the long side 2 of the slab 1 with the vertical V encloses a right angle. This is in Fig. 5 shown. The slab is thus arranged vertically edgewise. This has the particular advantage that here in a particularly simple manner, the two long sides 2 and 3 can be ground simultaneously, which a corresponding time reduction of the processing of the slab 1 allows. For this purpose, two grinding wheels 6 and 6 'are provided, which process the two sides 2, 3 at the same time.

The slab 1 here is otherwise - which is not mandatory, but is preferred - hanging, d. H. the receptacle 7 is here designed as a frame-like structure, the slab 1 at its lower and upper side, d. H. on the short sides 4, 5, clamps and holds in the position shown. The grinding table 13 is accordingly arranged in the upper region of the device. Of course, alternatively arranged in a clamping frame slab 1 can also be set up with a short side in the manner shown on a grinding table and processed as explained above.

In addition to the schematic representation according to Fig. 5 shows Fig. 6 a concrete embodiment of this concept.

Here are the two grinding devices 9 and 9 'to see that operate the grinding wheels 6 and 6'. The grinding devices 9, 9 'are equipped with the required actuating elements (hydraulic piston-cylinder systems) in order to be able to guide the grinding wheels 6, 6' vertically along the long sides 2, 3. In the here formed as a pit chip collecting box 17 is a vibrating conveyor 20 is arranged, with which the chips can be promoted for disposal.

With "vertical arrangement" of the slab 1, the chip flight 18 is optimized in such a way that the chips are conducted directly into the chip collecting box 17 arranged below the machine.

Compared with the conventional grinding of the slab reduce the processing times by more than half with the explained procedure, Not only the time for grinding the second long side is eliminated, but also the non-productive time for turning the slab 1.

A device-technical advantage continues to be that in "vertical arrangement" of the slab can be provided that both grinding devices 9, 9 'can be arranged in a common cabin or Eirihausung. Furthermore, the inspection of the grinding result is easier.

For converting or re-clamping the slab 1 for a possibly desired grinding of the short sides, the grinding devices 9, 9 'are arranged such that they can be swiveled away or moved sideways from the slab.

The grinding devices are usually equipped with hot-pressed grinding wheels 6. The drive power as well as the diameter and the width of the grinding wheel 6 are limited by the resulting from the manufacturing process of the disc strength thereof. Therefore, for the most part, grinding wheels with a diameter of, for example, 915 mm and a width of, for example, 150 mm are used, which requires motor drive powers which, for example, amount to 315 kW.

A higher throughput can theoretically be achieved with wider grinding wheels and higher engine power, which, however, has its limitations. Any widening of the grinding wheel is not possible due to the manufacturing process of the wheels and the strength of the binder for the abrasive grains.

LIST OF REFERENCE NUMBERS

1

Continuous casting product (slab)

2

long page

3

long page

4

short page

5

short page

6

grinding tool

6 '

grinding tool

7

admission

8th

surface normal

9

grinder

9 '

grinder

10

drive motor

11

contact surface

12

contact surface

13

grinding table

14

Grinding pressure cylinder

15

feed cylinder

16

edition

17

Swarf drawer

18

flying chips

19

baffle

20

Vibrating conveyor

V

vertical

α

angle

Claims (13)

1. A method for grinding a continuous casting product (1), particularly a slab, wherein the continuous casting product has a rectangular cross-sectional contour with two opposing long sides (2, 3) and two opposing short sides (4, 5), and wherein at least the long sides (2, 3) are subjected to a surface treatment by means of at least one grinding tool (6),
   characterized in that
   the continuous casting product (1) is positioned by means of a receiver (7) during the grinding of a long side (2, 3) of the continuous casting product (1) in such a way that the surface normal (8) of the long side (2, 3) of the continuous casting product (1) includes an acute angle (α) greater than zero degrees with the vertical line (V).
2. The method according to Claim 1, characterized in that the angle (α) between the surface normal (8) and the vertical line (V) lies between 30° and 90°.
3. The method according to Claim 2, characterized in that the angle (α) between the surface normal (8) and the vertical line (V) lies between 40° and 75°.
4. The method according to Claim 2, characterized in that the angle (α) between the surface normal (8) and the vertical line (V) amounts to 90°.
5. The method according to one of Claims 1 to 4, characterized in that a long side (2, 3), as well as a short side (4, 5), is ground by means of the at least one grinding tool (6) in a position of the continuous casting product (1) on the receiver (7).
6. The method according to Claim 4, characterized in that both opposing long sides (2, 3) of the continuous casting product (1) are simultaneously ground by means of at least two grinding tools (6, 6').
7. The method according to Claim 6, characterized in that the continuous casting product (1) is positioned in a suspended fashion during the grinding process by means of a receiver (7) in the form of a holding frame.
8. The method according to one of Claims 1 to 7, characterized in that the long side (2, 3) of the continuous casting product (1) is at least twice as long as the short side (4, 5) of the continuous casting product (1).
9. A device for grinding a continuous casting product (1), particularly a slab, wherein the continuous casting product has a rectangular cross-sectional contour with two opposing long sides (2, 3) and two opposing short sides (4, 5), and wherein the device features at least one grinding device (9) with at least one grinding tool (6) for grinding at least one long side (2, 3) of the continuous casting product (1), particularly for carrying out the method according to one of Claims 1 to 8,
   characterized in that
   the device comprises a receiver (7) that is designed for positioning the continuous casting product (1) during the grinding process in such a way that the surface normal (8) of the long side (2, 3) of the continuous casting product (1) includes an acute angle (α) greater than zero degrees with the vertical line (V).
10. The device according to Claim 9, characterized in that the angle (α) between the surface normal (8) and the vertical line (V) lies between 30° and 90°.
11. The device according to Claim 9 or 10, characterized in that it features two grinding devices (9, 9') with at least one respective grinding tool (6, 6'), wherein said grinding tools are designed and provided for simultaneously processing the two opposing long sides (2, 3) of the continuous casting product (1).
12. The device according to one of Claims 9 to 11, characterized in that the receiver (7) features a contact surface (11) for a long side (2, 3) of the continuous casting product (1) and a contact surface (12) for a short side (4,5) of the continuous casting product (1).
13. The device according to one of Claims 9 to 12, characterized in that the receiver (7) comprises a holding frame, by means of which the continuous casting product (1) can be positioned in a suspended fashion.

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