DE2447823A1 - MOLDING STEEL MILL FOR THE PRODUCTION OF PROFILE MATERIAL FROM METAL - Google Patents

Description

Pcrfenian whale

Dr.-Ing. Wilhelm Beichel
DipL-Ing. Wbliyäng lüichel

6 Franlduri a. M. 1 _Qn , _n

Parkstrasse © 13 ⁸⁰⁵ °

NIPPON STEEL CORPORATION, Tokyo, Japan

Sectional steel mill for the production of profile material from metal

The invention relates to a profile steel rolling mill for profiling of longitudinally expanded molding material or profile material Made of metal, such as angle steel, the web and flange parts of which have different lengths and thicknesses. the The invention relates in particular to a section steel mill with devices for correcting deformations which the Roll pass contour formed by at least two work rolls due to the expansion and contraction of the rolling mill and the work rolls is exposed in different directions.

It is known experience when rolling profiled material that the roller pass contour defined by two or more work rollers (roll-pass contour) due to the expansion and / or contraction of the rolling mill stand and those operated in the rolling mill Rolling is deformed, as a result of which products are produced with a cross-section that differs greatly from the inch dimensions.

Cross-sectional shapes of profile material made of metal do not only have a right-angled or a uniform width, e.g. ordinary panels, but they have different widths

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and thickness. When rolling out profile material with such complicated Cross-sectional shapes will be the metallic material between the work rolls in the rolling direction (the direction in which the material is transported), in the reducing direction (the direction perpendicular to the surface in contact with the rollers of the material) and deformed and shifted in the transverse direction (the direction parallel to the axes of the rollers).

When rolling metals into a material with a given cross-section, the roller pass contour is generally through several rollers defined. In order to get the desired cross-section exactly, it is necessary to shift the metallic To restrict the material in the direction of the roller axes to the extent of the rolling with respect to the corresponding parts of the roller passage contour balance. The deformation of the metallic material in the direction of the roll axes is variable and depends on the special shape of the roll pass and the roll load, which is applied in the vertical direction (reduction direction) is exercised.

If the roller pass contour remains in the originally dimensioned shape, it is possible to produce rolling stock with a cross-section that corresponds to the intended shape. In the practical rolling process, however, the rolling mill is insufficient Strength in the reducing direction (vertical direction) and opposing rolls are due to the rolling stock bent vertically away from each other in their central area (rolling reaction), causing fluctuations in the free passage width caused by the rollers. The clear passage width of the rollers is therefore subject to different parts of the roller gap Fluctuations of various sizes and contributes to the deformation of the metal material that passes through the rollers. this has

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finally, dimensional errors or deviations and irregular ones Fluctuations in the cross-section of the end product and sometimes bending of the rolled metal material as a consequence.

When rolling metal to predetermined cross-sections, the Adjustment of the clearance and the pressure (roller position in the axial direction) so far exclusively to avoid dimensional fluctuations and cross-sectional variations on experience. It is very difficult and almost impossible even for an experienced specialist to deform the 'roller pass contour correct exactly.

The object of the invention is therefore to specify a rolling mill that allows profile material made of metal to be given predetermined dimensions and to roll cross-sectional shapes. The purpose of the rolling mill is to correct the cross-section to be rolled in a simplified manner enable, and the rolling mill should also be able to correct curvatures and bends of the rolling material.

This task is carried out in a section mill, e.g. »a two-roll, Three-roll, four-roll universal rolling mill or a similar rolling mill achieved in that devices for adjustment the rigidity of the rolling mill are provided in the axial direction of the rollers. According to the invention, the correction of the Roll pass contour, i.e. the correction of the roll cross-sectional shape by means of adjusting the rolling mill rigidity achieved that the rolling mill rigidity in the axial direction of the Adjust rollers. The rigidity of the rolling mill in the vertical or reduction direction is usually fixed. Oppose it own the deviations in the axial direction of the rollers or the roller flow contour different behavior when the rolling mill rigidity is changed in the axial direction of the rollers. the

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Roll pass contour, which is the cross-sectional shape of the rolling stock can be corrected so that an optimal cross-sectional shape by means of the devices for adjusting the rolling mill stiffness ity is constantly maintained, the devices for adjusting the rolling mill rigidity the rolling mill rigidity in the axial direction in connection with the fixed stiffness in the vertical direction (reduction direction) keep in balance.

In a preferred embodiment, the rolling mill also contains a second device for adjusting the rolling mill rigidity, which adjusts the rolling mill rigidity in the vertical direction (reduction direction). In this case, the rolling mill has one variable stiffness in the vertical direction, whereby the control of the roller flow contours a greater degree of freedom required to ensure the desired rolling stock cross-section.

In the following, exemplary embodiments are described in more detail with reference to the drawing. Show it:

1 shows a schematic representation of a rolling mill according to the invention _p in which the devices for regulating the rolling mill rigidity are given in the form of a block diagram;

2a to 21 a schematic representation of the step-by-step reduction of a metallic workpiece which is shown in FIG several roll stands were rolled j

3 * shows a schematic cross section through the rollers used for rolling out an angle steel cross-section;

4 shows a schematic representation of a roller passage contour in which the correct circumferential shape is shown in a solid line _t deviations in the circumferential shape, on the other hand, with a dashed line;

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5 shows a graphic representation in which the computing steps for calculating the dimensional deviations at vertex B. the roller passage contour shown in FIG. 4 is indicated;

6 shows a block diagram of a sectional steel rolling mill with a plurality of rolling stands;

7 shows an illustration for calculating the roller displacements Δχ and ΔΥ as a function of the stiffness ratio

K -
-

8 shows an illustration of the coefficient of curvature

as a function of the stiffness ratio

In Fig. 1 is a preferred embodiment of the section mill shown according to the invention. The rolling mill is for rolling made of angle steel, the side walls of which are variable in length and thickness. The upper and lower work rolls 1 and 2 with a predetermined surface design are stored within a stand 3 in bearing shells or housings 4. the lower roller 2 is also by a fluid pressure device 5 supported, which moves the lower roller 2 up and down to increase the rigidity in the vertical. Direction (reduction direction of the workpiece).

An independent fluid pressure device 6 is on the outer sides of the bearing shells 4 for setting the rolling mill rigidity in Direction of the roller axes provided. This fluid pressure device 6 exerts a fluid pressure via the corresponding bearing shells 4 on the lower and upper rollers 1 and 2 parallel to the roller axes the end.

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The pressures of the first and second fluid pressure devices 5 and are controlled by the fluid pressure control unit 10 supplied with fluid pressure from a fluid pressure generator 9. the Dimensions in different areas of the form rolling material that comes out of the roll stand are determined by a detector 7 checked, and the perceived signals are forwarded to an operation unit 8. The operation unit compares the perceived signals with fixed reference signals, which have a predetermined roller flow contour (cross-sectional shape and dimensions) to produce output signals indicative of the corrective dimensional deviations. Of the Fluid pressure generator 9 then generates a corrective fluid pressure in accordance with the deviation signals of the operation unit 8, the corrective fluid pressure is determined by the dependent working from the deviation signals fluid pressure control unit 10 of the first or the second fluid pressure device 5 or 6 fed.

At the forming rolls of angle steel with a web and a flange of varying length and thickness of the metallic workpiece, for example, while it makes Durchlaufe.-multiple, or passes through several roll stands, gradually deformed, see figs. 2a to 21. Specifically, a metal blank having rectangular cross-section, see Fig. 2a, rolled in the first pass or roll stand into a shape shown in Fig. 2b and then rolled in the second pass or roll stand into the cross-section shown in Fig. 2c. In a similar way, the rolling stock is deformed by successive passes or roll stands in such a way that the cross-sectional shape shown in FIG. 21 finally results in the last pass or roll stand. The roller pass contours of the corresponding passages or roll stands have a shape corresponding to the cross-sections shown in FIGS. 2a to 21. For example, a rolling stock which has the cross-section shown in Fig. 2k,

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in the last pass or roll stand in those shown in FIG Transformed cross-section, a roller passage contour according to FIG. 3 being used.

Fig. 3 shows in cross section a roller passage contour of the Rolls, in which the rolling stock cross-section according to FIG. 2k in the Cross-section according to FIG. 21 is transformed. The metallic rolling stock is in the passage or roll passage 13 between • 'of the upper and lower rollers 1 and 2 rolled out. The upper and the lower rollers 1 and 2 are fixedly connected to the shafts 11 and 12, respectively, so that when the shafts 11 and 12 rotate the metallic rolling stock runs through the roll passage 13 and thereby assumes the cross section shown in FIG. the Design of the surfaces of the rollers 1 and 2 are also such as the positions of the shafts 11 and 12 before the start of the rolling operation,. Derart determined that the roll passage 13 is a predetermined Has cross-sectional shape.

At the beginning of the rolling process, when the metallic rolling stock enters the rollers, the roller flow contour is on. deformed in various places depending on the rigidity of the rolling mill in the vertical and transverse direction. The roll stand is normally brought into a position ₉ which takes into account the anticipated deformation of the cross-sectional shape in the roll pass 13, the metallic rolling stock is then rolled into the cross-sectional shape intended according to FIG. 21 in the initial stage of the rolling operation. While the rolling operation takes place, there are complicated changes in the roller flow contour 13 ₉ which are caused by thermal deformations of the rolling stock, the rollers, the stands, etc. or in positional deviations in the vertical or transverse direction of the upper or lower roller, which are usually caused by abrasion the rolling stock processing surfaces or the pressure bearing surfaces 14 and 15 of the upper and lower rollers 1 and 2 are caused.

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The roller flow contour 13, which is due to the above-mentioned causes is deformed, then have the shape shown by the dashed line 13 'in Fig. 4, for example. Fig. 4 shows in the roller passage 13, which is defined by the upper and lower rollers 1 and 2, on an enlarged scale. The deformation of the The rolling contour is determined by the relative displacement of the upper and lower rollers 1 and 2 in the vertical direction (Direction of the Y-Y axis) and parallel to the roller axes (direction of the X-X axis). In Fig. 4 represent the solid lines the correct shape of the roll passage 13 and the dashed lines that in the course of the rolling operation caused deformation.

The initial shape of the roll passage 13 has web and flange parts, offset at an angle to one another, of thickness h 1 and h 1, which in the course of the rolling process are increased to thicknesses h ^f _w and h ^! _{F can be} enlarged or reduced. The apex angle f also changes in jp ^"8 ο Ia this case, the positional deviation of the -Scheitels B (in the position B ²⁾ can be expressed with the illustration of Fig. Pursuant _s t? Obei ^ Y the relative vertical displacement of the upper wad tanteres Orphan 1 wan 2 (as gap displacement) and AX represents the relative trsaeversal © Yersetgtmg (parallel to the roller axes or to the direction of the axis 2S = I) «, the web and the flange have angles oC and jß ₉ with respect to the roller axis (axis XX) the thickness of the web on the left-hand side of FIG. 5 can be calculated as follows on the basis of geometric relationships:

- ^h w - ^hS w

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The flange shown on the right-hand side of FIG. 4 is subject a thickness variation that turns out to be

= Y sin

f (2)

can be printed out. Equations (1) and (2) result in the vertical and transverse changes in the roll gap AX and AY zu

^Ah W

From geometrical relationships, see Fig. 5, the change A1, results in the web length AB due to the sizes AX and to

AIw = AX sin * + AY sin fi (3 ¹ )

The change AIF of the flange length results in a similar way BC in the shape

AlF = AX sinoC + AY sin / S (4 »)

The changes in thickness Ahw and AhF result from a comparison of the quantities h ¹ «measured on the outer side of the roll stand. and h'p with the specified comparison values (target values) h ^. and hpj then result in the vertical and transverse change AX and ΔΪ of the nip according to equations (3) and (4). The changes in length ^ l ^ and Alp then result from equations (3 ¹ ) and (4 ¹ ) (these changes can also be determined by measurements).

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During the rolling process of the rolling mill according to the invention shown, for example, in FIG. 1, the detector 7 takes the dimensions (h'y, h ^f _F ) of the various parts of the metallic rolling stock on the output side of the rolling stand for comparison with the predetermined reference values (h ^ , hp) within the operating unit

8 from. As a result of this comparison, the vertical and transverse roll gap changes 4X and ΔΥ are calculated. The operation unit 8 generates output signals indicative of nip changes & X and ΔΥ which are sent to the fluid pressure generator

9 and the fluid pressure control unit 10 are transmitted in order to control the first fluid pressure device 5 and / or the second fluid pressure device 6 in such a way that the deviations ΔΧ and & Y are made to disappear.

In fact, it is extremely difficult to find the deviations ÄX. and to operate ΔΥ without an extremely large structural effort in the construction of the rolling mill, to make it disappear completely. As can be the equations (i) and (2) refer to, are the gap changes ΔΧ ΔΥ and corresponding thickness variations and Er- ^ equal AX and AY, multiplied by the constant sine * and sinis. Therefore, in order to keep the dimensional deviations evenly in different parts of the profile material, it is not necessary to make the values ^ X and ΔΥ disappear, rather it is sufficient to keep a balance between these values

δχ%

- * ti

i.e.

ΔΥ. - | HJ

sin $

ΔΧ · _ ~ 1ιρ (5)

ΔΪ * ~ sing

h _v

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Since the sizes and are constant, the result is the same

ⁿ F ⁿ W
moderate dimensional deviations when the quantities / JX and ΛΥ are controlled so that equation (5) is satisfied. This equation can easily be fulfilled by regulating the pressures of the first and second fluid pressure devices 5 and 6, see FIG. If the dimensional deviations of the different parts of the profile material from a roll stand are adjusted in this way, the cross-section of the profile material in the subsequent roll stands can be checked and controlled much more easily than without this adjustment, whereby a dimensionally accurate and precise cross-sectional shape of the end product can be achieved.

The foregoing description illustrates the operation of a roll stand, on the other hand the profile material passes through a plurality of mutually similar and arranged one after the passages or rolling stands, as explained in connection with Figures _2a-o 21st It should be noted that the present invention can be used in a roll stand or in roll stands at any production stage.

6 shows a block diagram of a multi-stand form rolling mill, in which the present invention is used in certain roll stands. The rolling mill contains several rolling stands 15 to 22, through which the metallic profile material runs one after the other. Of these are rolling stands set up in series the hatched roll stands 15, 18 and 19 with the inventive Equipped with devices for adjusting the rigidity. In Fig. 6, reference numeral 7 indicates a dimension detector at. In the entry stands 20 to 22, the metallic rolling stock is rolled raw under relatively high rolling pressure, a precise one It is not necessary to check the shape of the cross-section. According to the invention equipped rolling stands can be used more effectively on the exit side of the multi-stand rolling mill. The detector 7 can be attached to each exit side of each roll stand

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or attach to only one side of a specific roll stand, which stands at the end of several similar roll stands, see Fig. 7, the output signals of the detector 7 then also being used to control and regulate the rolling stands in front of it Alternatively, the output signals of a single detector can also be used to control several roll stands.

To simplify the explanations, the force required to stretch or contract the rolling mill by a unit of length is denoted by K, the vertical stiffness by Ky, the transverse stiffness by Κ _χ and the roll load by P. If the load in the reduction direction is P, the roll gap in the reduction direction is Sy, the load parallel to the roll axes (thrust direction) is Ρ _χ , the roll gap in the direction parallel to the roll axes is S _x , and the thickness hy of the rolling stock in the reduction direction is = Sy + Y. On the other hand, the thickness ίι _{χ of} the rolling stock

in the direction parallel to the roller axes h _Y = S + e ^ =. Amounts to

a Ji _x

Therefore, see FIG. 4, the rolling load on the web AB of the metallic rolling stock P _w within the roll passage 13 'and the Y / roller load on the flange BC has the size P', with the corresponding vertical components P ^ ₇ and P 'y and the transverse components P ^ _x and Pp _x , the following equations result:

ΔΣ - .. fe. (6)

~ ¹ VX ⁺¹⁸ EX ₍₆₎

^Δϊ = Ίζ- ■ ·; (7)

- ^P re ⁺ _ ^F rc (7)

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where Ky. the rolling stiffness in the transverse direction parallel to the roll axes and Ky the rolling mill stiffness in the vertical direction (reduction direction). Furthermore, if the roller loads for the correct roller flow _contour 13 are denoted by P wn and P ^ _n , then the following results:

. ΔΧ -I- ^9P y.-. ΔΙ (8)

2ΔΥ

Pt? ~

. ΔΧ

P - ^r po '®ΔΧ "<* ΔΥ

-f ^ L. . _Δ ϊ (9)

where P "the sum of the" vectors P- ^ _x and P ™ y "and Pp the sum of the vectors Ρ _ρχ and Ppy.

From equations (6) to (9) it can be seen that the changes ΛΧ and ΔΥ of the roll gap and the roll loads P ″ and Ρ ™ are correlated with one another. The changes A ^- X. and the roll gap are influenced by the roll loads P ™ and Pp, and the reverse type is also influenced. As can be seen from equations (1) and (2), the changes Δ X and ΔΥ cause fluctuations in the thickness of the metallic rolling stock; they are determined by the values of the vertical and transverse stiffnesses Κ _χ and Ky. Therefore, if the values Κ _χ and Ky are fixed, it is extremely difficult to determine the values ΔΧ and

To make ΔY disappear. This is due to the fact that a change in the values ^ X and ΛΥ causes changes in the quantities P ^ and P _p and thus in the quantities P ,, -, + Ρρ _χ and P ~ y +. The parameters that influence the values ^ X and ΔΊ must now be considered. As shown in Fig. 4, the vertical and transverse roll loads are:

^P W ^{= P} WX ^{+ P} WY ^P F ^{= P} FX ^{+ P} FY »

so that equations (8) and (9) are rewritten as follows can be:

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where the following relationships are already known:

ρ ρ

WX + ^r FX

^{+ P} FY

K ₁

Within these equations represent the values

and PpYQ components of the roller reaction force within a correct, non-deformed roller passage contour 13 and are

3 p Qp> « ~. " WX to ° FY result as

ä ΔΧ d ΔΥ fixed values that depend on the type of rolling material. The quantities ^ X and ΔΎ are calculated from equations (3) and (4) based on the dimensions perceived after rolling. The six values K ^, Κ _γ , P ^, Ρ ^ γ, Pp ^ and Ρργ are unknown, but they can be calculated from the six equations mentioned above, which represent a system of equations with six unknowns. After scanning and measuring the web and flange thicknesses, the quantities / iX and ΔΥ are calculated from equations (3) and (4) and substituted in equations (10) to (13) and (6) and (7), whereby the unknown parameters including the rolling mill stiffness K _v and K ₇ can then be determined. The metallic rolling stock can therefore be rolled to a correct cross-sectional shape when the fluid pressures

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of the first and second fluid pressure devices 5 and 6 can be controlled or regulated _{in the form of the values Κ χ and Ky.} If a load detector for checking and perceiving the vertical load Ρ _γ (= P ^ y + Ppy) and another detector for perceiving the transverse load Ρ _χ C = P ^ _x ^{+ ρ} ρχ) ^{in the} rolling mill according to Fig. 1, the values Κ _χ and Ky can be determined directly from equations (6 ^f ) and (7 '), since the quantities P ^ y + Ppy and P ^ _x + Ppy were then determined by measurements. In this case, it is then not necessary to solve the system of equations (10) to (13). In Fig. 1, the loads P _v and P _{Y are} indicated by the output signals of a fluid pressure detector connected to the first and second fluid pressure devices 5 and 6; The output signals of the fluid pressure detector are fed to an operation unit 8, which is also supplied by the detector 7 with signals which indicate the degree of the deviations ΔΧ and ΔΥ. On the basis of the signals received, the operating unit 8 calculates and delivers the values K _v and K _v which are required to carry out the necessary correction of the cross-sectional deformation.

The section mill according to the invention has so far been related described with the control of the cross-sectional shape of a roll forming material. However, it can also be used for control purposes and correct the curvatures in the rolling stock, as described below. - ·

The variations in thickness cause different expansion between different parts of the cross-sectional area of the metallic rolling stock. These differences in relative extent cause curvatures in the metallic rolling stock. If, for example, in the deformed roll passage 13 »of Fig. 4, the web AB of the rolling stock an elongation or expansion AW and the flange BC is subject to an expansion ^ F, the relationship arises

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AW
SA = +1 (14)

AF

If, on the other hand, the web and puddle extensions are given in the correct roller passage contour 13 by Wo and Fo, this results the relationship:

A correction coefficient (bend assessment coefficient) CA. definable as follows:

If the curvature coefficient CX = 0, the metallic rolling stock has the desired curvature (normally the relevant sizes are selected so that no curvature is produced). If CA has a large positive or negative value, the rolling stock also has a curvature due to which it deviates greatly from the design values. The illustration in Fig. 7 shows the relative roller displacements ΔΧ and ZiY in the vertical and transverse direction as a function of changes in the vertical stiffness Ky and the transverse stiffness Κ _χ and as a function of the stiffness ratio K = X. The diagram after

FIG. 8 shows representations of the data based on FIG. 7 Curvature coefficient CA «

The sectional steel rolling mill according to the invention can also be used in the form shown in FIG. 1 to control the curvatures of the metallic rolling stock. In the rolling mill shown in Fig. 1, the vertical rolling mill rigidity Ky is controlled by the first fluid pressure device 5 and the transverse rigidity by the second fluid pressure device 6, so that curvatures in the rolling stock can be easily corrected _{by adjusting the rigidity ratio Κ χ.}

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Claims (1)

Claims Sectional steel mill for the production of profile material from metal, in which a metallic rolling stock for production a predetermined cross-sectional shape through a roller gap shaped in a predetermined manner runs through, which is formed between several, oppositely arranged rollers, characterized, that a first fluid pressure device (5) for adjustment the rolling mill stiffness is provided in the transverse direction parallel to the roll axes, and that pressure control means (7 to 10) for controlling and regulating the fluid pressure in the first Fluid pressure means (5) are provided which maintain the transverse stiffness in a suitable ratio keep to the vertical rigidity of the rolling mechanism. Sectional steel mill according to Claim 1, characterized in that that a second fluid pressure device (6) for adjusting the rolling mill rigidity in the reduction direction is provided, and that the pressure control devices (7 to 10) for controlling the fluid pressure in the first Fluid pressure device (5) and the second fluid pressure device (6) are formed. 509834/0822 3. 'Sectional steel mill according to claim 2, characterized in that the pressure control devices (7 to 10) have a detector (7) attached to the output side of a roll stand for perceiving the cross-sectional shape of the metallic rolling stock, an operating unit (8) for comparing the output signals of the detector (7) with predetermined reference signals and for generating them of control signals, a fluid pressure generator (9) and a fluid pressure control unit (10) included. 4. Sectional steel mill according to claim 3 »characterized in that further fluid pressure detectors in connection with the first and the second fluid pressure device (5, 6) are provided, and that the further fluid pressure detectors are designed to generate output signals which indicate the roller loads in the reduction direction and the transverse direction and on the operation unit (8) are transferred. ReRb / Pi. 509834/0822 Blank page