EP1725352B1 - Roller leveller with variable axle distance - Google Patents

Abstract

Tractionless planishing machine has at least the first five rollers from the inlet with an inter-axis relationship on a radius identical to that of a conventional planishing machine and at least the last five rollers from the inlet with an inter-axis relationship on a radius close to that of a bending machine. The inter-axis relationship between the intermediate rollers is advantageously augmented. An independent claim is also included for: the planishing of metal strip using this planishing machine.

Description

The present invention relates to a non-tensile planer for gluing metal strips according to the preamble of claim 1, and the planing method using said planer.

A planer according to the planer described in the preamble of claim 1 is known from the document FR-A-2334440 .

A metal strip or plate undergoes various operations, such as hot rolling and cold rolling, to impart consistent dimensional characteristics along its length; thus a laminated metal strip theoretically possesses at all points a constant thickness and width.

However, the rolling operation is not sufficient to obtain a band free of defects. Indeed, it may have non-developable flatness defects such as corrugations at the banks or the center, and / or developable defects such as a hanger or a tile, ie a curvature respectively depending on the length, depending on the width of the band.

These flatness defects can be corrected by planing the web in a roller planer. Such a planer consists of two superimposed cassettes each supporting several motorized rollers of constant diameter, offset relative to each other, and arranged alternately above and below the path of the strip. This type of planer is configured, in terms of number of rollers, roll diameter, center distance and adjustment, so as to satisfactorily plan strips whose thickness is within a defined range.

In a conventional planer, the centers between the rollers are constant and are adjusted so that the ratio of roll diameter to center distance is from about 0.90 to about 0.95. However, in this type of planeuse, efforts and planing couples are important. In order to reduce them, the manufacturers have developed planers in which all the distances are increased so that the ratio between the diameter and the center distance is of the order of 0.70 to 0.80. However, this no longer makes it possible to correct the non-developable defects on the entire range of the leveler in terms of strip thickness, and in particular on the strips of thinner thickness.

The manufacturers have also proposed to retract part of the rollers, and to go for example from nine to five rolls. But, when the number of useful rollers is reduced, the variations in the rate of plasticization inside the planer are abrupt, and it becomes difficult to control the developable defects.

The present invention therefore aims to provide a planer in which the efforts and the planing torque are reduced compared to those of a conventional planer, while maintaining a good correction of flatness over the entire range of the planer, and by facilitating the control of the hanger and the tile.

$$\mathrm{pour\; k}\mathrm{:}\mathrm{n}\mathrm{-}\mathrm{3}\mathrm{à\; n}\mathrm{,}\left(\mathrm{R}\mathrm{/}\mathrm{Ek}\right)\mathrm{=}\left(\mathrm{R}\mathrm{/}\mathrm{En}\right)\mathrm{,}$$

$$\left(\mathrm{R}\mathrm{/}\mathrm{En}\right)\mathrm{<}\left(\mathrm{R}\mathrm{/}\mathrm{E}\mathrm{1}\right)\mathrm{,}$$

et
pour k : 5 à (n-1), (R/En) ≤ (R/Ek) ≤ (R/E1), et (R/Ek) ≥ (R/E(k+1)),
ladite planeuse comprenant éventuellement des moyens de réglages des entraxes Ek.To this end, the subject of the invention is a non-traction planer intended to glide metal strips, having an inlet and an outlet, comprising n + 1 rollers, of the type comprising two superimposed cassettes each supporting at least n / 2 motorized rollers of constant radius R, offset relative to each other and arranged alternately above and below the path of the strip, the axis of each of the rollers of a cassette being separated from the axis of the immediately following roll of the another cassette by a center distance Ek, in which: $$\mathrm{for\; k}\mathrm{:}\mathrm{2}\mathrm{at}\mathrm{4}\mathrm{,}\left(\mathrm{R}\mathrm{/}\mathrm{Ek}\right)\mathrm{=}\left(\mathrm{R}\mathrm{/}\mathrm{E}\mathrm{1}\right)\mathrm{,}$$

$$\mathrm{for\; k}\mathrm{:}\mathrm{not}\mathrm{-}\mathrm{3}\mathrm{to\; n}\mathrm{,}\left(\mathrm{R}\mathrm{/}\mathrm{Ek}\right)\mathrm{=}\left(\mathrm{R}\mathrm{/}\mathrm{In}\right)\mathrm{,}$$

$$\left(\mathrm{R}\mathrm{/}\mathrm{In}\right)\mathrm{<}\left(\mathrm{R}\mathrm{/}\mathrm{E}\mathrm{1}\right)\mathrm{,}$$

and
for k: 5 to (n-1), (R / En) ≤ (R / Ek) ≤ (R / E1), and (R / Ek) ≥ (R / E (k + 1)),
said planer optionally comprising means for adjusting the distances Ek.

• n ≥ 8,
• lorsque l'épaisseur de la bande à planer est comprise entre 0,5 et 3 mm, 14 ≤ n ≤ 22,
• lorsque l'épaisseur de la bande à planer est comprise entre 3 et 15 mm, 10 ≤ n ≤16,
• pour k : 1 à x, 0,90 ≤ R/Ek ≤ 0,95, et pour k : (x+1) à n, 0,70 ≤ R/Ek ≤ 0,80.
• pour k : 1 à x, 0,90 ≤ R/Ek ≤ 0,95, l'un des entraxes Ex, avec 5 ≤ x ≤ n-4, étant tel que : 0,80 ≤ R/Ex ≤ 0,90, et pour k : (x+1) à n, 0,70 ≤ R/Ek ≤ 0,80.
• pour k : 1 à x, 0,90 ≤ R/Ek ≤ 0,95, l'un des entraxes Ex, avec 5 ≤ x ≤ n-4, étant tel que : 0,80 ≤ R/Ex ≤ 0,90, et 0,75 ≤ R/E(x+1) ≤ 0,85, et pour k : (x+2) à n, 0.70 ≤ R/Ek ≤ 0,80.

The planer according to the invention may furthermore have the following characteristics:

• n ≥ 8,
• when the thickness of the strip to be hovered is between 0.5 and 3 mm, 14 ≤ n ≤ 22,
• when the thickness of the glide strip is between 3 and 15 mm, 10 ≤ n ≤16,
• for k: 1 to x, 0.90 ≤ R / Ek ≤ 0.95, and for k: (x + 1) to n, 0.70 ≤ R / Ek ≤ 0.80.
• for k: 1 to x, 0.90 ≤ R / Ek ≤ 0.95, one of the distances Ex, with 5 ≤ x ≤ n-4, being such that: 0.80 ≤ R / Ex ≤ 0.90 , and for k: (x + 1) at n, 0.70 ≤ R / Ek ≤ 0.80.
• for k: 1 to x, 0.90 ≤ R / Ek ≤ 0.95, one of the distances Ex, with 5 ≤ x ≤ n-4, being such that: 0.80 ≤ R / Ex ≤ 0.90 , and 0.75 ≤ R / E (x + 1) ≤ 0.85, and for k: (x + 2) at n, 0.70 ≤ R / Ek ≤ 0.80.

The subject of the invention is also a method for flattening a metal strip, in particular a steel strip, in which this planer is used with a plasticization ratio greater than or equal to 60% and less than or equal to 90%.

As will be understood, the invention consists in proposing a planing machine in which at least the first five rollers from the entry of the planer have a center to center ratio identical to that of conventional planers, at least the last five rollers from the entrance of the planer have a center-to-spoke ratio close to that of a stripper, and wherein the distance between the intermediate rollers of the planer is advantageously increased.

• la figure 1 présente une vue schématique en coupe transversale d'une planeuse multirouleaux sans traction selon l'invention,
• la figure 2 présente une courbe de calcul du cintre résiduel d'une bande métallique planée, en fonction du serrage de sortie de la planeuse, pour un taux de plastification de 60 %, et
• la figure 3 présente une courbe de calcul du cintre résiduel d'une bande métallique planée, en fonction du serrage de sortie de la planeuse, pour un taux de plastification de 80 %.

The features and advantages of the present invention will become more apparent from the following description, given by way of non-limiting example, with reference to the appended figures in which:

• the figure 1 has a schematic cross-sectional view of a multi-roll planer without traction according to the invention,
• the figure 2 presents a calculation curve of the residual hanger of a flat metal strip, as a function of the output clamping of the leveler, for a plasticization ratio of 60%, and
• the figure 3 presents a design curve of the residual hanger of a flat metal strip, as a function of the output clamping of the leveler, for a plasticization rate of 80%.

On the figure 1 , schematically shown a planer 1 comprising two 2.3 superimposed cassettes and each supporting motorized rollers 4,4 'of constant radius R. To glide a metal strip 5, this strip 5 is passed between the rollers 4,4 'and a planer inlet corresponding to the entrance of the strip 5 in the planer 1 is thus defined, and a planer output corresponding to the leaving the strip 5 out of the leveler 1. The rollers 4,4 'are positioned offset from each other, and arranged alternately above and below the path of a metal strip 5. To obtain a correct leveling of the band 5, each cassette 2,3 must support at least n / 2 rolls 4,4 'and more precisely for a planer 1 having n + 1 rollers 4,4' the lower cassette 2 has (n / 2 ) +1 rolls 4 and the upper cassette 3 has n / 2 rolls 4 '. The axis of each of the rollers 4,4 'of a given cassette 2,3 is separated from the axis of the roll 4,4' immediately successive of the other cassette by a distance Ek which can be variable.

To obtain a flat strip 5 with a null hanger, it is necessary to adjust the spacing of the rollers 4 of the lower cassette 2 with respect to the rollers 4 'of the upper cassette 3 located at the output of the planer 1, it is necessary to ie to adjust the input clamping and the output clamping of the leveling machine 1. In order to adapt the adjustment according to the type of band 5 to be hung, it is possible to vary the center distance Ek by means of adjustment means not shown.

The inventors have demonstrated that a reduction in the ratio of radius on the center distance between the rollers to a value of about 0.8, starting from the fifth roll from the entry of the planer, in a planer whose ratio radius on center distance between at least the first five rollers from the entry of the planer corresponded to the ratio radius on the center distance of a conventional planer, efforts and planing pairs could be reduced by 5 to 25% depending on the type of adjustment made.

Thus, for the first five rollers from the input of the planer, that is to say when k varies from 2 to 4, the ratio R / Ek is equal to the ratio R / E1, in which E1 corresponds to the center distance between the first roll from the planer entry and the second roll from the planer entry, R / E1 being between 0.90 and 0.95, included terminals, values which correspond to the ratio radius on center distance of a conventional planer.

For the last five rolls from the entrance of the planer, that is to say when k varies from n-3 to n, the ratio R / Ek is equal to the ratio R / En, in which En corresponds to distance between the last roll from the entry of the planer and the penultimate roll from the entry of the planer, R / En being between 0.70 and 0.80, inclusive, values which correspond to the ratio of radius to center distance of a conventional stripper.

Thus, in the planer according to the invention, it is clear that the ratio R / E1 is always greater than the ratio R / En. Furthermore, it is also appropriate that between the fifth roll from the input and the roll n-1 from the input of the planer, ie when k varies from 5 to n-1, has the following relationships: $$(\mathrm{R}/\mathrm{In})\le (\mathrm{R}/\mathrm{Ek})\le (\mathrm{R}/\mathrm{E}1),\mathrm{and}(\mathrm{R}/\mathrm{Ek})\ge (\mathrm{R}/\mathrm{E}\left(\mathrm{k}+1\right))\mathrm{.}$$

These conditions make it possible to reduce the forces exerted on the rollers, to reduce the torque necessary for planing. Thus for an equivalent result in terms of planing, the power of the planer according to the invention will be 15 to 20% lower than the power of a conventional planer.

In addition, the inventors have found an increase in the number of operating points using a planer according to the invention, compared to a conventional planer having the same number of rollers. The number of operating points of a planer is determined by the adjustment to be made on the planer to obtain, at the output of the planer, a band having a zero hanger and a null tile. Thus, the greater the number of operating points for a given leveler, the lower the stress at the settings. This represents an additional advantage because the duration of the adjustment of the planer according to the invention will be reduced.

In order to obtain a correct correction of the non-developable defects of the flatness of the strip, it is essential that the ratio R / Ek is equal to the ratio R / E1, to the accuracy near the adjustments of distance between the rollers, for at least the five first rolls from the entrance of the planer.

Preferably, the planer comprises more than nine rolls, that is to say n greater than or equal to 8, to allow good correction of both defects not developable as developable defects. Indeed, under nine rollers, it becomes difficult to control the developable defects, and the sheet can retain a tile and a hanger residual.

Advantageously, to facilitate the adjustments and to obtain a good correction of all flatness defects of a metal strip in a thickness range between 0.7 and 3 mm, the planer comprises between 15 and 23 (inclusive), that is 14 ≤ n ≤ 22.

When the metal strip is in a thickness range of between 3 and 15 mm, the planer advantageously comprises between 11 and 17 rolls, that is to say 10 ≤ n ≤ 16.

According to the quality of resolution of flatness defects and the search for gain in effort and in planing torque, the inventors have developed different types of planer, which we will describe.

According to a first embodiment of the invention, the planer is divided into two zones. A first zone is thus between the first roll from the entry of the planer and the roll (x + 1) from the entry of the planer, that is to say when k varies from 1 to x, and extends at least to the fifth roll from the entrance of the planer. In this first zone, the ratio radius on center distance R / Ek is constant and between 0.90 and 0.95 (inclusive). The second zone is between the roll (x + 1) from the input of the leveler and the last roll from the input of the leveler which is the roll (n + 1), ie when k varies from (x + 1) to n, and starts at least from roll n-3 from the input of the planer. In this zone, the radius-to-center ratio R / Ek is constant and lies between 0.70 and 0.80 (including terminals).

According to a second embodiment of the invention, the planer is divided into three zones. A first zone is comprised, as in the first embodiment, between the first roller from the entrance of the planer and the roller (x + 1) from the entrance of the planer, ie when k varies from 1 to x, and extends at least to the fifth roll from the input of the planeuse. In this zone, the ratio radius on center distance R / Ek is constant and between 0.90 and 0.95 (including terminals). Then, a second zone in which one of the reports radius on center distance, which will be called R / Ex, is between 0.80 and 0.90 (inclusive). This second area is between the fifth roll from the planer entry and the roll (n-4) from the planer entry, ie when x varies from 5 to (n- 4). Finally, a third area is located between the roll (x + 1) from the input and the last roll of the planer (roll (n + 1)), ie when k varies from (x + 1) ) to n. In this third zone, the radius-to-center ratio R / Ek is constant and lies between 0.70 and 0.80 (inclusive).

According to a third embodiment of the invention, the planer is also divided into three zones. A first zone is understood, as in the previous embodiments, between the first roll from the entry of the planer and the roll (x + 1) from the entry of the planer, ie when k varies from 1 to x, and extends at least to the fifth roll from the entrance of the planer. In this zone, the radius-to-center ratio R / Ek is between 0.90 and 0.95 (including terminals). Then, a second zone in which one of the radius-to-center ratios, which will be called R / Ex, is between 0.80 and 0.90 (including terminals), and the radius ratio on the R / E distance ( x + 1) is between 0.75 and 0.85 (inclusive). This second area is between the fifth roll from the planer entry and the roll (n-4) from the planer entry, ie when x varies from 5 to (n- 4). Finally, a third zone is located between the roll (x + 2) from the planer entry and the last roll of the planer (roll (n + 1)), ie when k varies from (x +2) to n. In this third zone, the radius-to-center ratio R / Ek is constant and lies between 0.70 and 0.80 (inclusive).

The invention also relates to a method for gliding a metal strip in which one of the planers described above is used with a plastification rate equal to or greater than 60% and equal to or less than 90%.

The plasticization rate of a metal strip is defined as the thickness of the plasticized metal strip over the total thickness.

Thus, if the plastification rate is less than 60%, it is no longer possible to remedy the flatness defects of the strip. On the other hand, if this ratio is greater than 90%, the metal strip becomes difficult to glide, and in this case it is also difficult to remedy the flatness defects of the strip.

The metal strip to be hovered may be steel, ordinary or stainless, coated with a metal coating for example based on zinc or an organic coating.

The invention will now be illustrated by examples given for information only, and not limiting.

Planeuse A :

pour k : 1 à 4, R/Ek = 0,95, et
pour k : 5 à 16, R/Ek = 0,80.

Planeuse B :

pour k : 1 à 4, R/Ek = 0,95,
pour k = 5, R/Ek = 0,865, et
pour k : 6 à 16, R/Ek = 0,80.

Planeuse C :

pour k : 1 à 4, R/Ek = 0,95,
pour k = 5, R/Ek = 0,90, et R/E(k+1) = 0,85, et
pour k : 7 à 16, R/Ek = 0,80.

A conventional leveling machine, designated by X planer, comprising (k + 1) rolls with k equal to 16, or seventeen rolls, diameter 57 mm and constant center distance Ek 30 mm (BRONX type planer), thus having a ratio radius over constant center distance R / Ek of 0.95, has been modified to obtain different planers according to the invention, namely:

Planer A:

for k: 1 to 4, R / Ek = 0.95, and
for k: 5 to 16, R / Ek = 0.80.

Planer B:

for k: 1 to 4, R / Ek = 0.95,
for k = 5, R / Ek = 0.865, and
for k: 6 to 16, R / Ek = 0.80.

Planer C:

for k: 1 to 4, R / Ek = 0.95,
for k = 5, R / Ek = 0.90, and R / E (k + 1) = 0.85, and
for k: 7 to 16, R / Ek = 0.80.

Each of these levelers A, B, C and X is then passed through a strip of steel 2 mm thick by 1000 mm wide, applying either a 60% plasticization rate, ie 80%. The steel in question is a steel of the THR1000 type whose yield strength R _p0.2 is 900 MPa.

The figures 2 and 3 presents a curve of calculation of the residual hanger of the planed steel strip, according to the output clamping of the planer, for a level of plastification of 60% ( figure 2 ) and a plasticization rate of 80% ( figure 3 ).

• planeuse A : symbole ■,
• planeuse B : repère ▲,
• planeuse C : symbole X, et
• planeuse X : symbole ◆.

The different planers are identified by the following symbols:

• Planer A: symbol ■,
• planer B: mark ▲,
• planer C: symbol X, and
• X planer: ◆ symbol.

Finally, for each leveler and according to the plasticization rate, the planer input forces, the planer output forces, the total forces, and the planer torque are identified. Then, the gains obtained in each of the planers A, B and C according to the invention are calculated with respect to the conventional X planer, and all the results are summarized in Tables 1 and 2. Table 1: gain on forces and torque and number of operating points, at 60% plasticization rate Gain on the input efforts of planeuse (%) Gain on the output exits of planeuse (%) Gain on total effort (%) Gain on the total torque of the planeuse (%) Number of operating points Planer A 23 11 17 35 1 Planer B 18 14 15 31 3 Planer C 15 14 14 25 9 Planer X - - - - 6 Gain on the input efforts of planeuse (%) Gain on the output exits of planeuse (%) Gain on total effort (%) Gain on the total torque of the planeuse (%) Number of operating points Planer A 23 8 16 27 5 Planer B 17 11 14 24 5 Planer C 15 13 14 22 5 Planer X - - - - 4

From these two tables of results, that the planeuse A is the planeuse which makes it possible to obtain the biggest gains in effort and torque, and whatever the rate of plasticization. However, as we can see from the figures 2 and 3 , this planer is not necessarily the most reliable if it is desired to give the sheet a perfectly zero hanger, since, especially when the plasticization rate is 60%, the number of operating points is 1, then that it is 9 for the planer C.

Claims (9)

1. Tensionless leveller (1) intended for levelling a metal strip (5), having an entry and an exit, comprising n+1 motorized rolls (4,4'), of the type comprising two superposed cassettes (2, 3) each supporting at least n/2 rolls (4, 4') of constant radius R, offset with respect to one another and placed alternately above and below the path of the strip (5), the axis of each of the rolls (4, 4') of one cassette (2, 3) being separated from the axis of the immediately successive roll (4,4') of the other cassette by a centre-to-centre spacing E_k, in which: $$\mathrm{for\; k}\mathrm{:}\mathrm{2}\mathrm{to}\mathrm{4}\mathrm{,}\left(\mathrm{R}\mathrm{/}{\mathrm{E}}_{\mathrm{k}}\right)\mathrm{=}\left(\mathrm{R}\mathrm{/}{\mathrm{E}}_{\mathrm{1}}\right)\mathrm{;}$$

   

   $$\mathrm{for\; k}\mathrm{:}\mathrm{n}\mathrm{-}\mathrm{3}\mathrm{to\; n}\mathrm{,}\left(\mathrm{R}\mathrm{/}{\mathrm{E}}_{\mathrm{k}}\right)\mathrm{=}\left(\mathrm{R}\mathrm{/}{\mathrm{E}}_{\mathrm{n}}\right)\mathrm{,}$$

   

   $$\left(\mathrm{R}\mathrm{/}\mathrm{En}\right)\mathrm{<}\left(\mathrm{R}\mathrm{/}\mathrm{E}\mathrm{1}\right);$$

   

   and
   for k: 5 to (n-1), (R/E_n) ≤ (R/E_k) ≤ (R/E₁), and (R/E_k) ≥ (R/E_(k+1)),
   said leveller (1) optionally including means for adjusting the centre-to-centre spacings E_k.
2. Leveller (1) according to Claim 1, in which n ≥ 8.
3. Leveller (1) according to either of Claims 1 and 2, in which, when the thickness of the strip (5) to be levelled is between 0.5 and 3 mm, 14 ≤ n ≤ 22.
4. Leveller (1) according to either of Claims 1 and 2, in which, when the thickness of the strip (5) is between 3 and 15 mm, 10 ≤ n ≤ 16.
5. Leveller (1) according to any one of Claims 1 to 4, in which: $$\mathrm{for\; k}\mathrm{:}\mathrm{1}\mathrm{to\; x}\mathrm{,}0.90\le \mathrm{R}\mathrm{/}{\mathrm{E}}_{\mathrm{k}}\le 0.95;$$

   

   and $$\mathrm{for\; k}\mathrm{:}\left(\mathrm{x}\mathrm{+}\mathrm{1}\right)\mathrm{to\; n}\mathrm{,}\mathrm{0.70}\mathrm{\le }\mathrm{R}\mathrm{/}{\mathrm{E}}_{\mathrm{k}}\mathrm{\le }\mathrm{0.80.}$$

   
6. Leveller (1) according to any one of Claims 1 to 4, in which:

   - for k: 1 to x, 0.90 ≤ R/E_k ≤ 0.95;

   - one of the centre-to-centre spacings E_x, where 5 ≤ x ≤ n-4, being such that: $$\mathrm{0.80}\mathrm{\le }\mathrm{R}\mathrm{/}{\mathrm{E}}_{\mathrm{x}}\mathrm{\le }\mathrm{0.90}\mathrm{;}$$

   

   and

   - for k: (x+1) to n, 0.70 ≤ R/E_k ≤ 0.80.
7. Leveller (1) according to any one of Claims 1 to 4, in which:

   - for k: 1 to x, 0.90: ≤ R/E_k ≤ 0.95;

   - one of the centre-to-centre spacings E_x, where 5 ≤ x ≤ n-4, being such that : $$\mathrm{0}\mathrm{,}\mathrm{80}\le \mathrm{R}/\mathrm{Ex}\le 0,90,\mathrm{and}\mathrm{0}\mathrm{,}75\le \mathrm{R}/{\mathrm{E}}_{\left(\mathrm{x}+1\right)}\le 0,85;$$

   

   and

   - for k: (x+2) to n, 0.70 ≤ R/E_k ≤ 0.80.
8. Method for levelling a metal strip (5) in which a leveller (1) according to any one of Claims 1 to 7 is used, leveller in which the degree of plastic deformation is at least 60% and at most 90%.
9. Levelling method according to Claim 8, in which the metal strip (5) is a steel strip.

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