STRAIGHTENING MACHINE AND METHOD FOR STRAIGHTENING A METAL STRIP OR A FLAT METAL PART

- Kohler Maschinenbau GmbH

A straightening machine (1) and a method for straightening a metal strip or a flat metal part (16) by the straightening machine, having upper straightening rollers (3) in an upper roller mill (2) and lower straightening rollers (6) in a lower roller mill (5). The upper and lower straightening rollers form upper and lower roller mill planes with a straightening gap therebetween and act on the metal strip to be straightened. In a working position, the upper roller mill plane forms an operating angle to the lower roller mill plane. The straightening gap (11) is changed by adjusting the upper roller mill plane relative to the lower roller mill plane. Before or at the start of a straightening process, the upper and/or lower roller mill is put in a starting position with a widened straightening nip, at least until a front end of the material strip has entered the inlet of the working region and for the rest of the straightening process, the upper and/or lower roller mill is put in the working position.

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Description
TECHNICAL FIELD

The invention relates to a method for straightening a material strip or a flat material part composed of metal or another material which can be plasticized by means of a straightening machine as well as a straightening machine for straightening such a material strip or flat material part.

The invention relates in general to a method and a straightening machine for a metal strip or a flat metal part; therefore, for the purpose of simplification, only a “metal strip” or “metal part” is discussed, which refers to a material strip or a metal part composed of metal or another material which can be plasticized.

BACKGROUND

A straightening machine of the present type contains a number of upper straightening rollers, which are mounted in an upper roller mill, and a number of lower straightening rollers, which are mounted in a lower roller mill. In this case, the upper and lower straightening rollers are arranged so that they form between an inlet and an outlet of the straightening machine in an operating region between the upper and lower roller mill a straightening gap in order, in an operating position in which an upper roller mill plane is parallel to a lower roller mill plane or forms an operating angle, to act at least temporarily from top to bottom on the metal strip or metal part to be straightened and guide this in an operating direction from the inlet to the outlet through the straightening machine. The operating angle normally opens toward the outlet; there are, however, special applications in the case of which the opening angle opens toward the inlet. The axes of the upper straightening rollers in the upper roller mill and the axes of the lower straightening rollers in the lower roller mill lie at least in part, preferably all, in the upper or lower roller mill plane.

A change in the straightening gap is normally performed by a parallel displacement of the upper roller mill plane relative to the lower roller mill plane so that the straightening gap can be adapted to a thickness of the metal strip or flat metal part to be straightened.

In the metal-processing industry, metal strips are often used which are supplied as coils and are unwound from there for production. By winding up the strip material to form coils, as well as by possible previous thermal treatment and the like, unevenness and tensions arise in the strip material which are inexpedient for further processing. Metal strips are therefore, after unwinding from the coil, generally conducted through the straightening gap of a straightening machine of the present type so that the metal strip can be supplied flat and with a low degree of tension for further processing. The same also applies to flat metal parts which should be made free from undesirable bending and tension which are generated in particular also during punching, bending or cutting of the metal parts.

Straightening machines of the present type serve to do away with such tensions and unevenness in metal strips or metal parts. The upper and lower straightening rollers are, for this purpose, arranged offset to one another along the straightening gap in such a manner that the material to be straightened is alternately bent around upward and downward on the straightening rollers. The bending is performed in the normal case so that the material at least at the first straightening rollers is bent beyond its yield point so that undesirable bending and tension in the material are balanced out as completely as possible. If the operating angle opens toward the outlet, as is usually the case, the material on the first straightening rollers of the straightening machine is highly plasticized. At each further straightening roller, the material is bent to a slightly lesser extent, and at the last straightening roller, the material is usually no longer plasticized, i.e. only elastically deformed.

As a result of the narrow advancing of the straightening rollers and the significant reshaping caused as a result of the metal part or metal strip during straightening, crushing can occur in the region of ends, edges or corners of the metal part or metal strip to be straightened, which crushing results in a tapering of the thickness or the cross-section of the metal strip or metal part. It has therefore been proposed in DE 10 2015 102 271 A1 to set the straightening gap in the region of the inlet of the straightening machine initially to a predetermined starting value which preferably corresponds approximately to the material thickness of the part to be straightened in order to avoid the above-mentioned crushing. Only after the metal part or metal strip runs into the operating region of the straightening machine is an advancing of the upper and/or lower straightening rollers to a preset end value for the straightening process performed. The advancing and/or placing of the upper and/or lower straightening rollers for setting the straightening gap is performed in this case by parallel displacement of the upper and/or lower roller mill to one another. It has, however, been shown that an advancing and placing of the upper and/or lower straightening rollers for setting the straightening gap can only be carried out very late if the part to be straightened has already been transported far into the straightening machine. This leads to it not being optimally possible to straighten the region around the front end of the part to be straightened.

SUMMARY

The object on which the invention is based is to propose a method for straightening a metal strip or a flat metal part by means of a straightening machine as well as a straightening machine of the above-mentioned type, with which the avoidance of crushing in the region of a front end of the metal part or metal strip to be straightened is improved alongside simultaneous, as optimal as possible straightening of the metal part or metal strip.

This object is achieved by a method for straightening a metal strip or a flat metal part by means of a straightening machine with one or more of the features disclosed herein as well as by a straightening machine with one or more of the features of disclosed herein. Preferred further development of the method are described below and, in the claims, along with advantageous configurations of the straightening.

The method according to the invention for straightening a material strip or a flat material part is performed by means of a straightening machine with a number of upper straightening rollers in an upper roller mill and a number of lower straightening rollers in a lower roller mill, which form a straightening gap between an inlet and an outlet of the straightening machine in an operating region between the upper and the lower roller mill, wherein the upper and the lower straightening rollers in an operating position of the upper and lower roller mill act at least temporarily from top to bottom on the material strip or material part to be straightened and guide it in an operating direction from the inlet to the outlet of the operating region through the straightening machine, wherein at least a part of the axes of the upper straightening rollers spans an upper roller mill plane and at least a part of the axes of the lower straightening rollers spans a lower roller mill plane, which in the operating position are parallel or at a predetermined operating angle to one another, wherein, in order to change or set the straightening gap, the upper roller mill and/or the lower roller mill can be adjusted relative to the respective other roller mill and is placed at least into a starting position with widened straightening gap and can be advanced into the operating position.

Prior to or at the start of a straightening process the upper and/or lower roller mill is placed into the starting position at least until a front end of the material strip or material part has run into the inlet of the operating region of the straightening machine, and for the further straightening process the upper and/or lower roller mill is advanced into the operating position, wherein the metal strip or the metal part is guided in the operating direction through the straightening gap of the straightening machine for the straightening process.

According to the invention, the straightening gap during placing into the starting position is widened to a greater extent at the inlet that at the outlet, or is widened to a greater extent at the outlet than at the inlet, i.e. the upper and/or the lower roller mill is adjusted in such a manner that the angle between the two roller mill planes changes.

The straightening gap during placing into the starting position is preferably widened to a greater extent at the inlet than at the outlet if the operating angle opens toward the outlet or the upper roller mill plane is parallel to the lower roller mill plane. If, in contrast, the operating angle opens toward the inlet, the straightening gap during placing into the starting position is preferably widened to a greater extent at the outlet than at the inlet.

The following method steps are preferably performed:

    • (A) placing the upper and/or lower roller mill into the starting position; and
    • (B) advancing the upper and/or lower roller mill into the operating position,

wherein method step B is performed when or after the front end of the material strip or material part has reached a predetermined position in the operating region.

As a result of the method according to the invention, it is made possible that the metal part or metal strip to be straightened can be introduced into the straightening machine without crushing of the front end, wherein the straightening result is improved over the prior art. This is because it can be achieved by angled adjustment of the upper roller mill plane with respect to the lower roller mill plane that those regions of the straightening gap, in which the greatest deformation of the material to be straightened occurs, are widened to a maximum extent, while the other regions of the straightening gap are widened to a lesser degree or not at all, i.e. the front end of the item to be straightened is also partially straightened in the starting position.

In the case of an operating angle which, as is usually the case, opens toward the outlet, the advancing of the upper and/or lower roller mill into the operating position can be carried out at an early stage so that the region of the front end of the metal strip or metal part is also at least partially straightened without crushing of the front end arising in this case. As a result of the change in the angle between the upper and lower roller mill plane during the advancing into the operating position, the upper and lower straightening rollers come into contact earlier with the metal strip or metal part to be straightened, in particular with the region adjacent to the front end of the metal strip or metal part, as a result of which the straightening result for the metal strip or metal part is improved.

The upper straightening rollers in the upper roller mill are preferably arranged in such a manner that the axes of all the upper straightening rollers run in the upper roller mill plane. Alternatively, the upper roller mill plane is formed by the axes of a plurality, but not all the upper straightening rollers. For example, in the case of a first upright upper straightening roller in the operating direction, the upper roller mill plane is formed by the axes of all the upper straightening rollers without the first upper straightening roller in the operating direction.

The lower straightening rollers in the lower roller mill are preferably arranged in such a manner that the axes of all the lower straightening rollers run in the lower roller mill plane. Alternatively, the lower roller mill plane is formed by the axes of a plurality, but not all the lower straightening rollers. For example, in the case of a last lowered lower straightening roller in the operating direction, the lower roller mill plane is formed by the axes of all the lower straightening rollers without the last lower straightening roller in the operating direction.

In the operating position, the operating angle is, as is known per se, preferably formed in such a manner that the straightening gap in the region of the outlet corresponds substantially to the thickness of the metal strip or metal part to be straightened and in the region of the inlet lies below the thickness of the metal strip or metal part. In special cases, an operating angle is occasionally selected which is oriented in a reversed manner.

In some cases, the operating angle is equal to zero, i.e. the roller mill planes are parallel to one another, and the straightening gap corresponds to the thickness of the material to be straightened or is a little smaller than this.

The predetermined position preferably lies in the region of the inlet, or is determined by a location of one of the lower or upper straightening roller in the operating direction, preferably by the location of a first, second, third, fourth or fifth lower or upper straightening roller in the operating direction. The predetermined position along the operating direction thus forms a type of trigger for the movement of the upper and/or lower roller mill into the operating position. The location of the predetermined position can in this case be specified for the respective straightening machine or input and changed in a control unit of the straightening machine independently of the metal part or metal strip to be straightened, in particular independently of its thickness.

The predetermined position is preferably determined by the location of one of the first upper or lower straightening rollers in the operating direction so that the advancing into the operating position can be performed at an early stage after the metal strip or metal part to be straightened has run into the operating region of the straightening machine. Alternatively, the location of the predetermined position can also be selected depending on the metal strip or metal part to be straightened.

A further preferred configuration of the method according to the invention is characterized in that the front end of the material strip or material part is detected by means of a sensor, preferably a physical sensor, in particular an optical or inductive sensor. A sensor signal is generated by the sensor if the front end of the metal strip or metal part passes or reaches the sensor. In response to the sensor signal, the upper and/or the lower roller mill can be moved immediately or with a time delay into the operating position.

The sensor is preferably formed as a light barrier which extends transversely to the operating direction in a transport plane of the metal strip or metal part. The detection of the front end of the metal strip or metal part can thus be performed in a simple and reliable manner.

Alternative or preferably additionally, the sensor is arranged at a predetermined position and method step B is performed immediately after detection of the front end of the metal strip or metal part by the sensor. The upper and/or lower roller mill is thus moved immediately into the operating position in response to the sensor signal generated by the sensor.

In one preferred embodiment of the method, the arrangement of the sensor is performed at a spacing in the operating direction upstream of the predetermined position, wherein a time delay is determined until the predetermined position of the front end of the material strip or material part is reached from a conveying speed of the material strip or material part and the spacing between the sensor and the predetermined position, and method step B is performed with or after the end of the time delay after detection of the front end of the material strip or material part by the sensor. In particular if the predetermined position is supposed to lie within the straightening machine, it is thus possible as a result of the structural circumstances to arrange the sensor at an easily accessible position at which an undisturbed measurement of the front end of the metal strip or metal part can also be carried out.

The arrangement of the sensor is preferably performed directly in front of the inlet of the straightening machine, as a result of which in particular reliable measurement and good accessibility are enabled at all times and it is possible to operate with a short time delay.

The placing of the upper and/or lower roller mill into the starting position is preferably performed in such a manner that the straightening gap in the region of the inlet corresponds at least to the thickness of the material strip or material part. By placing the upper and/or lower roller mill in the region of the inlet at a spacing which corresponds at least to the material thickness of the metal strip or metal part, it is ensured that the front end of the metal strip or metal part does not collide with an upper and/or lower straightening roller, as a result of which damage to the upper and/or lower straightening roller as well as a crushing of the front end of the metal strip or metal part is/are avoided.

Alternatively or preferably additionally, the advancing of the upper and/or lower roller mill into the operating position is performed in such a manner that the straightening gap in the operating position in the region of the outlet corresponds substantially to the thickness of the material strip or material part.

One preferred embodiment of the method, above all in the case of an operating angle which opens toward the outlet, is characterized in that the movement of the upper and/or lower roller mill into the operating position is performed in an incremental or step-by-step manner. As a result of the incremental or step-by-step movement of the upper and/or lower roller mill into the operating position, it can in particular be avoided that the front end of the metal strip or metal part hits one of the upper straightening rollers. A deformation of the front end of the metal strip or metal part or damage to the straightening rollers can thus be avoided. At the same time, the incremental advancing into the operating position makes it possible that the metal strip or metal part in the portion of the operating region upstream in the operating direction, which has already been passed by the front end of the metal strip or metal part, is at least partially straightened. In particular, the region of the metal strip or metal part adjacent to the front end of the metal strip can thus be better straightened so that overall a better straightening result can be achieved.

A step of advancing is preferably performed with or after passing a lower and/or upper straightening roller, wherein the advancing in the step is preferably performed in such a manner that the straightening gap at a downstream upper and/or lower straightening roller corresponds substantially to the thickness of the metal strip or metal part. By adjusting a downstream lower and/or upper straightening roller in such a manner that the spacing corresponds substantially to the thickness of the metal strip or metal part, it is avoided that the front end of the metal strip or metal part collides with the subsequent upper and/or lower straightening roller and that a crushing is performed in the region of the front end of the metal strip or metal part. At the same time, the metal strip or metal part is moved toward the outlet in a manner guided by the operating region of the straightening machine. As a result of the angled adjustment of the upper with respect to the lower roller mill plane, straightening forces are furthermore exerted on the metal strip or metal part by the upper and/or lower straightening rollers which have already been passed so that the metal strip or metal part is correspondingly optimally straightened.

An advancing of the straightening machine is thus preferably carried out with or after passing a lower and/or upper straightening roller in small steps in such a manner that, in the operating position, the straightening gap corresponds substantially to the thickness of the metal strip or metal part finally in the region of the outlet of the straightening machine.

The spacing of the front end of the metal strip or metal part downstream of the sensor or the predetermined position can also serve as a trigger for the incremental movement of the upper and/or lower roller mill into the operating position. For example, an advancing of the front end of the metal strip or metal part by a certain distance or by a certain time interval after passing the predetermined position can be a trigger for a further step of advancing into the operating position, wherein a further step of advancing is performed after travelling a further distance or after the expiry of a further time interval. The number of steps depends in particular of the metal part or metal strip to be straightened, in particular on its thickness. Alternatively or preferably additionally, the length of the operating region and the number of the upper and/or lower straightening rollers and their spacing also have an effect on the number of steps for the incremental advancing of the roller mills into the operating position.

The movement of the upper and/or lower roller mill into the operating position can also be performed continuously. As soon as the front end of the metal strip or metal part has reached the predetermined position, the upper and/or lower roller mill is moved linearly or in an accelerated manner into the operating position. The speed or acceleration of the continuous movement of the upper and/or lower roller mill into the operating position can preferably correlate with a speed of the metal strip or metal part and/or with the position of the metal strip or metal part within the straightening machine, in particular with the spacing of the front end of the metal strip or metal part to the predetermined position.

In one preferred embodiment, the movement of the upper and/or lower roller mill into the starting position is carried out at least partially via a pivoting movement, preferably about a pivot axis outside the operating region of the straightening machine. The upper and/or lower roller mill is thus pivoted with respect to the respective other roller mill into the starting position in such a manner that the angle between the upper and lower roller mill plane transitions from the operating angle (which can also be equal to zero) into a starting angle which is different from the operating angle and the non-parallel widening according to the invention of the straightening gap is achieved. If the operating angle opens toward the outlet, the straightening gap in particular in the region of the inlet is widened to a spacing at least in the region of the material thickness of the metal strip or metal part, while the straightening gap in the region of the outlet can be barely changed or not at all.

The upper and/or lower roller mill can be moved with a pure pivoting movement or in such a manner into the starting position that a parallel displacement of the upper and/or lower roller mill is performed and at the same time or consecutively a pivoting movement is performed. As a result of this, it is made possible that the metal strip or metal part to be straightened can be easily pulled into the straightening machine and optimally straightened, wherein crushing in the region of the front end of the metal strip is also avoided.

A straightening machine according to the invention for straightening a material strip or a flat metal part comprises a number of upper straightening rollers in an upper roller mill and a number of lower straightening rollers in a lower roller mill which form between an inlet and an outlet of the straightening machine in an operating region between the upper and the lower roller mill a straightening gap in order, in an operating position of the upper and lower roller mill, to act at least temporarily from top to bottom on the material strip or material part to be straightened and guide it in an operating direction from the inlet to the outlet of the operating region through the straightening machine. At least a part of the axes of the upper straightening rollers forms an upper roller mill plane and at least a part of the axes of the lower straightening rollers spans a lower roller mill plane, wherein the upper roller mill plane and the lower roller mill plane, in the operating position, are parallel or at a predetermined operating angle to one another. In order to change or set the straightening gap, the upper roller mill and the lower roller mill are adjustable relative to one another, can be placed at least into a starting position with a widened straightening gap and can be advanced into the starting position.

The straightening machine further comprises a controller for adjustment of the upper and lower roller mill with respect to one another and a sensor for detection of a front end of the metal strip or metal part to be straightened and outputting a sensor signal to the controller.

According to the invention, the upper roller mill and the lower roller mill are adjustable relative to one another in such a manner that the straightening gap during placing into the starting position is widened to a greater extent at the inlet than at the outlet or is widened to a greater extent at the outlet than at the inlet, i.e. the upper roll mill plane encloses a starting angle to the lower roller mill plane in the starting position, which starting angle is different from the operating angle, wherein the controller is formed in such a manner that it adjusts the upper and/or lower roller mill from the starting position into the operating position immediately in response to the sensor signal or with a time delay.

The straightening machine makes it possible to introduce the metal part or metal strip to be straightened in the starting position of the roller mills into the straightening machine so that a crushing or a rolling out of the front end of the metal part or metal strip is avoided. This improves the quality of the metal part or metal strip. Moreover, as a result of the placing possible according to the invention of the upper and/or lower roller mill into the starting position with widening, which is not parallel according to the invention, of the straightening gap, in particular in the region of the inlet of the straightening machine at the start of the straightening process, an abutment of the front end of the metal part or metal strip against one of the first straightening rollers during introduction is avoided, as a result of which the durability of the components is improved.

The sensor is preferably arranged at the height of a predetermined position, or upstream in the operating direction at a spacing in front of the predetermined position. In particular the upstream arrangement, preferably before the inlet of the straightening machine, enables simple installation and maintenance of the sensor.

The predetermined position preferably lies in the region of the inlet, or corresponds to a location of one of the upper and lower straightening roller, preferably the location of a first, second, third, fourth or fifth lower or upper straightening rollers in the operating direction.

The controller of the straightening machine is preferably formed so that the time delay for the adjustment of the upper and/or lower roller mill into the operating position is determined from a conveying speed of the material strip or material part and the spacing between the sensor and the predetermined position. As a result of this, it is made possible that the sensor can be arranged outside the straightening machine and the predetermined position can simultaneously lie within the straightening machine.

The sensor is preferably a physical sensor, in particular an optical or inductive sensor. The optical sensor involves in particular a light barrier.

A further preferred embodiment of the straightening machine is characterized in that the upper roller mill is pivotable with respect to the lower roller mill and/or the lower roller mill is pivotable with respect to the upper roller mill about a pivot axis, wherein the pivot axis preferably lies outside the operating region of the straightening machine.

The upper roller mill is preferably retained in guides of the straightening machine and can be moved up and down on the guides relative to the lower roller mill, wherein the guides are formed in such a manner that the upper roller mill is adjustable and/or pivotable asymmetrically on the guides. The attachment of the upper roller mill by means of these guides makes it possible that the forces acting on the metal strip or metal part to be straightened can be correspondingly absorbed and a movement of the upper roller mill with small tolerances can simultaneously be carried out. The guides furthermore enable a translational movement of the upper roller mill toward the lower roller mill and away from it.

In an even further preferred embodiment of the straightening machine, the upper roller mill is pivotable by means of a pivoting apparatus, wherein the pivoting apparatus is operatively connected at least to the guides which are arranged in the region of the outlet. In particular, a compact design can be achieved in this manner, in the case of which all the key components for pivoting and also for translational movement of the upper roller mill are arranged thereon or are operatively connected thereto. As a result of this, a retrofitting of existing systems with a pivotable upper roller mill is also enabled.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of a straightening machine configured according to the invention, on the basis of which an exemplary embodiment of a method according to the invention is also explained, is described below on the basis of the enclosed drawings. In the drawings:

FIG. 1 shows a schematic side view of the straightening machine in the starting position; and

FIG. 2 shows a schematic side view of a straightening machine in the operating position.

 DETAILED DESCRIPTION

A straightening machine 1 according to the invention is represented schematically in a side view in a starting position in FIG. 1. The straightening machine 1 comprises an upper roller mill 2 on which a multiplicity of upper straightening rollers 3, in the present case four upper straightening rollers 3, is arranged. A lower roller mill 5 which also comprises a multiplicity of lower straightening rollers 6, in the present case five lower straightening rollers 6, is arranged opposite the upper roller mill 2. The upper and lower straightening rollers 3, 6 are in the upper and lower roller mill 2, 5 equidistant and arranged in such a manner that an upper straightening roller 3 engages into the region of the space between two lower straightening rollers 6.

A lower roller mill plane 7 runs through the axes 9 of the lower straightening rollers 6; an upper roller mill plane 4 runs in an analogous manner through the axes 9 of the upper straightening rollers 3. Alternatively, the upper roller mill plane 4 can only partially comprise the axes 9 of the upper straightening rollers 3, in particular if a first upper straightening roller 3 in the operating direction 14 is raised with respect to the further upper straightening rollers 3. The lower roller mill plane 7 can likewise only partially comprise the axes 9 of the lower straightening rollers 6 in particular if a last lower straightening roller 6 in the operating direction is lowered.

The upper roller mill 2 is guided on four guides 20 which are configured as stud bolts, and it can be moved along these guides 20 translationally to the lower roller mill 5 and moved away therefrom. The upper roller mill 2 is guided in the guides 20 in such a manner that the upper roller mill 5 is adjustable within the guides 20 asymmetrically between inlet 12 and outlet 13 of the straightening machine 1 and/or is pivotable about an axis which runs parallel to the roller mill planes 4, 7.

For this purpose, there is arranged on the upper roller mill 2 a pivoting apparatus 21, by means of which the upper roller mill 2 is pivotable with respect to the lower roller mill 5 about a pivot axis, as a result of which the upper roller mill plane 4 is also changed with respect to the lower roller mill plane 7. The pivoting apparatus 21 is in this case operatively connected to the guides 20, arranged at the outlet 13, of the straightening machine 1. In addition to the pivoting apparatus 21, the upper roller mill 2 can be moved up and down with respect to the lower roller mill 5 in the guides 20 parallel to the lower roller mill 5.

In the starting position of the straightening machine 1, as is represented in FIG. 1, the lower roller mill plane 7 and the upper roller mill plane 4 enclose a starting angle 10 which opens toward the outlet 13. This starting angle 10 between the upper and lower roller mill plane 4, 7 in the starting position is formed in this case so that it is smaller than an operating angle 8 in the operating position (FIG. 2), i.e. the straightening gap 11 is widened to a greater extent in comparison with the operating position at the inlet 12 than at the outlet 13. With a pivoting of the upper roller mill 2 with respect to the lower roller mill 5 about the pivot axis, the straightening gap 11 is widened along the operating region of the straightening machine 1 between inlet 12 and outlet 13 so that the spacing of the upper straightening rollers 3 with respect to the lower straightening rollers 6 is also increased overall in comparison with the operating position. In the starting position, the straightening gap 11 in the region of the inlet 12 is formed in such a manner that it corresponds at least to the thickness of the metal part 16 to be straightened. For further widening of the inlet 12 of the straightening machine 1, the upper roller mill 2 can, in addition to the pivoting movement about the pivot axis, also additionally be displaced parallel along the guides 20. The movement of the upper roller mill 2 is controlled or regulated via a controller 22. In addition to the upper roller mill 2, the pivoting apparatus 21 is also operatively connected to the controller 22.

For the straightening of the metal part 16, the straightening machine 1 is firstly brought into the starting position, as represented in FIG. 1, in which the straightening machine 1 has a widened straightening gap 11 and a starting angle 10 between the upper and lower roller mill plane 4, 7 which opens toward the outlet 13, but is formed to be smaller than the operating angle 8.

A flat metal part 16 to be straightened firstly passes a sensor 18 during transport into the straightening machine 1 in operating direction 14, which sensor 18 detects a front end 17 of the metal part 16. The sensor 18 is formed in the present case as a light barrier and is arranged in a region upstream of the inlet 12 in operating direction 14. As a result of the arrangement outside the straightening machine 1, the sensor 18 is easily accessible in comparison with an installation of the sensor 18 within the straightening machine 1 and enables fault-free detection of the front end 17 of the metal part 16. The sensor 18 arranged in such a manner can furthermore where necessary be adapted flexibly and quickly to different metal strips or parts to be straightened, in particular of a different thickness. Alternatively, it is also possible that the sensor 18 is arranged within the straightening machine 1, in particular in the region of the inlet 12 or one of the first upper or lower straightening rollers 3, 6. The sensor 18 is also operatively connected to the controller 22 and outputs a corresponding sensor signal to the controller 22 during detection of the front end 17 of the metal part 16.

The front end 17 of the metal part 16 firstly runs through the inlet 12 of the straightening machine 1 along the conveying path of the metal part 16 into the straightening machine 1, along which the metal part 16 is conveyed with a constant speed. By widening the straightening machine 1 in the region of the inlet 12 at least into the region of the material thickness of the metal part 16 by pivoting the upper roller mill 2 with respect to the lower roller mill 5, it is ensured that the front end 17 of the metal part 16 does not collide with an upper straightening roller 3 or the upper roller mill 2. Moreover, during entry into the straightening machine 1, the region around the front end 17 of the metal part 16 initially does not experience any forces which could lead to a deformation of the front end 17, in particular to crushing. As soon as the front end 17 of the metal part 16 has reached or passed a predetermined position 15 which in the present case corresponds to the location of the axis 9 of the second upper straightening roller in operating direction 14, the upper roller mill 2 is moved incrementally from the starting position, as is represented in FIG. 1, into the operating position, as is represented in FIG. 2.

In the operating position, the upper roller mill plane 4 and the lower roller mill plane 7 enclose an operating angle 8 to one another. A straightening gap 11 is formed between the upper and lower straightening rollers 3, 6 in the operating position over the operating region between inlet 12 and outlet 13, in which straightening gap 11 corresponding forces are exerted at least temporarily via the upper and lower straightening rollers 3, 6 from top to bottom on the metal part 16 to be straightened. In this case, the metal part 16 is bent between the upper and lower straightening rollers 3, 6 arranged offset to one another, wherein a more pronounced bending of the metal part 16, beyond its yield point, occurs in the region of the inlet 12. As a result of the bending of the metal part 16 in the straightening gap 11, bending and tension in the metal part 16 are reduced. A lower degree of bending of the metal part 16 occurs at each subsequent upper or lower straightening roller 3, 6 in operating direction 14 so that a straightened and flat metal part 16 is conveyed out of the straightening machine 1 at the outlet 13. The further processing of the metal part 16 is significantly simplified and improved by the straightening.

In the operating position, the operating angle 8 between the upper and lower roller mill plane 4, 7 is formed in such a manner that, in the region of the outlet 13, the straightening gap 11 corresponds substantially to the material thickness of the metal part 16 to be straightened and that, in the region of the inlet 12, the upper and lower straightening rollers 3, 6 in the straightening gap 11 have a spacing smaller than the material thickness of the metal part 16.

The axes 9 of the lower straightening rollers 6 lie here in the lower roller mill plane 7 and the axes 9 of the upper straightening rollers 3 span the upper roller mull plane 4, which opens toward the outlet 13. As a result of this, it is achieved that the metal part 16 to be straightened in the straightening machine 1 is bent to a lesser extent toward the outlet 13 and is only slightly deformed.

The movement or advancing of the upper roller mill 2 from the starting position, as represented in FIG. 1, into the operating position, as represented in FIG. 2, is primarily performed via a pivoting movement of the upper roller mill 2 by means of the pivoting apparatus 21. The pivoting movement is performed incrementally in several steps so that it can be ensured that the front end 17 of the metal part 16 does not collide with one of the upper straightening rollers 3 during conveying into the straightening machine 1. As a result of the incremental movement of the upper roller mill 2 into the operating position, it is furthermore ensured that no crushing occurs in the region of the front end 17 of the metal part 16.

The incremental advancing from the starting position into the operating position is performed as a function of the conveying of the metal part 16 through the straightening machine 1. A step of further advancing into the operating position is thus triggered by virtue of the fact that the front end 17 of the metal part 16 passes an upper straightening roller 3 arranged after the predetermined position 15. The advancing is performed in the respective step by virtue of the fact that the upper roller mill 2 is pivoted so that an upper straightening roller 3 downstream of the passed upper straightening roller 3 is positioned in such a manner that a spacing to the lower straightening rollers 6 arises which corresponds substantially to the material thickness of the metal part 16. It is thus ensured at all times that the front end 17 of the metal part 16 does not collide with one of the upper straightening rollers 3. The incremental advancing is performed until the front end 17 of the metal part has reached the outlet 13 and the straightening gap 11 in the region of the outlet 13 corresponds substantially to the material thickness of the metal part 16. The straightening gap 11 in the region toward the inlet 12 is furthermore advanced to a greater extent with each step, hence corresponding forces already act on the metal part 16 during advancing, as a result of which the straightening result is improved.

The movement of the upper roller mill 2 into the operating position is started after the front end 17 of the metal part 16 reaches the predetermined position 15. As represented in FIG. 1, the predetermined position 15 is located within the straightening machine 1 at the height of the axis 9 of the second upper straightening roller 3 downstream in the operating direction 14. As a result of the location of the predetermined position 15 within the straightening machine 1 in the vicinity of the inlet 12, it is likewise ensured that the front end 17 of the metal part 16 is not crushed and rolled out by excessive straightening forces and nevertheless the metal part 16 is optimally straightened. It is achieved in particular as a result of the pivoting movement of the upper roller mill 2 into the operating position that straightening forces are exerted at least partially on the region of the metal part 16 adjoining the front end 17 of the metal part 16, and indeed immediately after the predetermined position 15 has been passed by the front end 17 and the advancing into the operating position has been performed. Alternatively, the predetermined position 15 can lie e.g. also directly at the inlet 12 into the straightening machine 1.

As also represented in FIG. 1, the sensor 18 for detecting the front end 17 of the metal part 16 is not arranged directly at the predetermined position 15, but rather has a spacing 19 upstream in operating direction 14 to the predetermined position 15. In order to determine the point in time at which the front end 17 of the metal part 16 reaches the predetermined position 15, a time delay is determined via the spacing 19 and the conveying speed of the metal part 16, after which time delay the front end 17 has reached the predetermined position 15 after detection of the corresponding sensor signal by the sensor 18 and the upper roller mill 2 is then adjusted incrementally from the starting position into the operating position.

LIST OF REFERENCE NUMBERS

    • 1 Straightening machine
    • 2 Upper roller mill
    • 3 Upper straightening roller
    • 4 Upper roller mill plane
    • 5 Lower roller mill
    • 6 Lower straightening roller
    • 7 Lower roller mill plane
    • 8 Operating angle
    • 9 Axis (of 3, 6)
    • 10 Starting angle
    • 11 Straightening gap
    • 12 Inlet
    • 13 Outlet
    • 14 Operating direction
    • 15 Predetermined position
    • 16 Metal part
    • 17 Front end
    • 18 Sensor
    • 19 Spacing
    • 20 Guide
    • 21 Pivoting apparatus
    • 22 Controller

Claims

1. A method for straightening a material strip or a flat material part composed of a material which is plasticizable using a straightening machine (1) with a number of upper straightening rollers (3) in an upper roller mill (2) and a number of lower straightening rollers (6) in a lower roller mill (5), which form a straightening gap (11) between an inlet (12) and an outlet (13) of the straightening machine (1) in an operating region between the upper and the lower roller mill (2, 5), the upper and the lower straightening rollers (3, 6) in an operating position of the upper and lower roller mill (2, 5) act at least temporarily from top to bottom on the material strip or material part to be straightened and guide the material strip or part in an operating direction (14) from the inlet (12) to the outlet (13) of the operating region through the straightening machine (1), at least a part of axes (9) of the upper straightening rollers (3) form an upper roller mill plane (4) and at least a part of axes (9) of the lower straightening rollers (6) forms lower roller mill plane (7), which in the operating position are parallel or at a predetermined operating angle (8) to one another, the method comprising:

in order to change the straightening gap (11), at least one of adjusting the upper roller mill (2) relative to the lower roller mill (5) or adjusting the lower roller mill (5) relative to the upper roller mill (2); and
prior to or at a start of a straightening process, placing at least one of the upper or lower roller mill (2, 5) into a starting position at least until a front end of the material strip or material part has run into the inlet (12) of an operating region of the straightening machine (1) by widening the straightening gap (11) to a greater extent that at the outlet (13), widening the straightening gap (11) to a greater extent at the outlet (13) than at the inlet (12); and
for the further straightening process, advancing at least one of the upper or lower roller mill (2, 5) into an operating position.

2. The method as claimed in claim 1, wherein the straightening gap (11) during placing into the starting position is widened to a greater extent at the inlet (12) than at the outlet (13) if the operating angle (8) opens toward the outlet (13) or the upper roller mill plane (4) is parallel to the lower roller mill plane (7), or the straightening gap (11) during placing into the starting position is widened to a greater extent at the outlet (13) than at the inlet (12) if the operating angle (8) opens toward the inlet (12).

3. The method as claimed in claim 1, further comprising the method steps:

(A) placing at least one of the upper or lower roller mill (2, 5) into the starting position; and
(B) advancing at least one of the upper or lower roller mill (2, 5) into the operating position,
wherein method step B is performed when or after the front end (17) of the material strip or material part (16) has reached a predetermined position (15) in the operating region.

4. The method as claimed in claim 3, wherein a region of the inlet (11), or a location of one of the lower or upper straightening rollers (3, 6) is used as the predetermined position (15).

5. The method as claimed in claim 3, wherein the front end (17) of the material strip or material part is detected by a sensor (18).

6. The method as claimed in claim 5, wherein the sensor (18) is arranged at the predetermined position (15) and method step B is performed immediately after detection of the front end (17) of the material strip or material part (16) by the sensor (18).

7. The method as claimed in claim 5, wherein the sensor (18) is arranged at a spacing (19) upstream of the predetermined position (15) in the operating direction (14), and the method further comprises determining a time delay until the predetermined position (15) of the front end (17) of the material strip or material part (16) is reached from a conveying speed of the material strip or material part and the spacing (19) between the sensor (18) and the predetermined position (15), and method step B is performed with or after the end of the time delay after detection of the front end (17) of the material strip or material part by the sensor (18).

8. The method as claimed in claim 1, wherein at least one of a) the placing of at least one of the upper or lower roller mill (2, 5) into the starting position is performed such that the straightening gap (11) in a region of the inlet (12) corresponds at least to a thickness of the material strip or material part (16) or b) the advancing of at least one of the upper or lower roller mill (2, 5) into the operating position is performed such that the straightening gap (11) in a region of the outlet (13) corresponds substantially to the thickness of the material strip or material part (16).

9. The method as claimed in claim 1, wherein at least one of a) the placing of at least one of the upper or lower roller mill (2, 5) into the starting position is performed such that the straightening gap (11) in a region of the outlet (13) corresponds at least to a thickness of the material strip or material part (16) or 12) the advancing of at least one of the upper or lower roller mill (2, 5) into the operating position is performed such that the straightening gap (11) in a region of the inlet (12) corresponds substantially to the thickness of the material strip or material part (16).

10. The method as claimed in claim 1, wherein the advancing of at least one of the upper or lower roller mill (2, 5) into the operating position is performed continuously.

11. The method as claimed in claim 1, wherein the advancing of at least one of the upper or lower roller mill (2, 5) into the operating position is performed in an incremental manner.

12. The method as claimed in claim 11, wherein one step of the advancing is performed with or after passing at least one of one said lower or upper straightening roller (3, 6), and the advancing is performed in the step such that the spacing of the upper and lower straightening rollers (3, 6) at a downstream said upper and/or lower straightening roller (3, 6) corresponds substantially to the thickness of the material strip or material part (16).

13. The method as claimed in claim 1, wherein at least one of the upper roller mill (2) or the lower roller mill (5) is moved at least partially via a pivoting movement into at least one of the starting position or the operating position.

14. A straightening machine (1) for straightening a material strip or a flat material composed of a material which can be plasticized, the straightening machine comprising:

a number of upper straightening rollers (3) in an upper roller mill (2);
a number of lower straightening rollers (6) in a lower roller mill (5);
a straightening gap formed between an inlet (12) and an outlet (13) of the straightening machine (1) in an operating region between the upper and the lower roller mills (2, 5), the straightening gap (11), in an operating position of the upper and lower roller mills (2, 5) being configured to act at least temporarily from top to bottom on the material strip or material part to be straightened and guide the material strip or material part in an operating direction (14) from the inlet (12) to the outlet (13) of the working region through the straightening machine (1);
at least a part of axes (9) of the upper straightening rollers (3) form an upper roller mill plane (4) and at least a part of axes (9) of the lower straightening rollers (6) form a lower roller mill plane (7) which in the operating position are parallel or at a predetermined operating angle (8) to one another;
in order to change the straightening gap (11), the upper roller mill (2) and the lower roller mill (5) are adjustable relative to one another, and are placeable at least into a starting position with a widened straightening gap (11) and are advanceable into the starting position;
a controller (22) configured to adjust the upper and lower roller mills (2, 5) with respect to one another;
a sensor (18) for detection of a front end (17) of the material strip or material part (16) to be straightened, the sensor configured to output a sensor signal to the controller (22);
the controller (22) being further configured to adjust at least one of the upper or lower roller mill (2, 5) from the starting position into the operating position immediately after or with a time delay to the sensor signal; and
the upper roller mill (2) and the lower roller mill (5) are adjustable relative to one another such that the straightening gap (11) during placing into the starting position is widened to a greater extent at the inlet (12) than at the outlet (13), or is widened to a greater extent at the outlet (13) than at the inlet (12).

15. The straightening machine as claimed in claim 14, wherein the controller (22) is configured to widen the straightening gap (11) during placing into the starting position at the inlet (12) to a greater extent than at the outlet (13) if the operating angle (8) opens toward the outlet (13) or the upper roller mill plane (4) is parallel to the lower roller mill plane (7), or to widen the straightening gap (11) during placing into the starting position at the outlet (13) to a greater extent than at the inlet (12) if the operating angle (8) opens toward the inlet (12).

16. The straightening machine as claimed in claim 14, wherein the upper roller mill plane (4) encloses a starting angle (10) to the lower roller mill plane (7) in the starting position, and said starting angle (10) is not equal to the operating angle (8).

17. The straightening machine as claimed in claim 14, wherein the sensor (18) is arranged at a height of a predetermined position (15), or upstream in the operating direction (14) at a spacing (19) in front of the predetermined position (15), wherein the predetermined position (15) lies in a region of the inlet (12), or corresponds to a location of one of the lower or upper straightening rollers.

18. The straightening machine as claimed in claim 17, wherein the controller (22) is configured such that the time delay for the adjustment of at least one of the upper or lower roller mill (2, 5) into the operating position is determined from a conveying speed of the material strip or material part and the spacing (19) between the sensor (18) and the predetermined position (15).

19. The straightening machine as claimed in claim 14, wherein the sensor (18) is a physical sensor.

20. The straightening machine as claimed in claim 14, wherein at least one of a) the upper roller mill (2) is pivotable with respect to the lower roller mill (5) or b) the lower roller mill (5) is pivotable with respect to the upper roller mill (2) about a pivot axis, and the pivot axis lies outside an operating region of the straightening machine (1).

21. The straightening machine as claimed in claim 14, wherein the upper roller mill (2) is retained in guides (20) of the straightening machine (1) and is movable up and down on the guides (20) relative to the lower roller mill (3), and the guides (20) are formed such that the upper roller mill (2) is at least one of adjustable or pivotable asymmetrically on the guides (20).

Patent History
Publication number: 20230294153
Type: Application
Filed: Jun 9, 2021
Publication Date: Sep 21, 2023
Applicant: Kohler Maschinenbau GmbH (Lahr)
Inventor: Anton Müllerleile (Offenburg)
Application Number: 18/013,810
Classifications
International Classification: B21D 1/02 (20060101);