EP2817110B1 - Straightening method with positioning system for the product to be straightened - Google Patents

Description

The present invention relates to a method for straightening band-shaped material or parts, with which an exact positioning of the workpieces on a downstream processing machine, such as a press, scissors etc., is made possible.

In order to process strip-shaped materials made of metal, which are usually drawn off from a coil, a level alignment of the material is required for processing in a processing device, such as, for example, a punch press, scissors, a forming machine or the like. Before the material is processed in such a processing device, the material must be leveled, which is done by a straightening process.

For such a process, roller or roller leveling machines are preferably used which have a plurality of upper and lower leveling rollers or rollers arranged in an upper and a lower roller mill. These are arranged offset from one another, a so-called straightening gap being formed between the upper and lower straightening rollers. The number of straightening rollers essentially depends on the straightening task, which in turn depends on the thickness of the material to be straightened. The thicker the material to be straightened, the larger rollers are used, whereas smaller straightening rollers can be used for thin sheets.

If very different materials are processed in a manufacturing company, the aim is to keep the number of different straightening machines to a minimum. To increase the more universal use of a straightening machine, straightening machines with exchangeable cassettes have been developed, in which an adaptation to the material thickness can be made by exchanging the exchangeable cassettes.

In some applications, especially with the aim of achieving a very high flatness of the material, it has been proposed to straighten the process in a two-stage process Process to subdivide, wherein in a first stage a first straightening machine straightens the material and in a second machine following the first machine a further fine machining is arranged to increase the flatness and precision of the straightening result. Such a multi-leveler system is for example from the DE 10 2009 012 929 B3 known. This also describes the technical processes involved in roller or roller straightening in detail.

The processing of the leveling material is carried out in clocked fashion in corresponding processing devices, for example in the case of punch presses. This means that the directed straightening material is fed to the processing device by means of a feed and, after reaching a certain position, the feeding is interrupted at the moment when the punching tool engages in the direction perpendicular to the direction of movement of the straightening material in order to punch out the corresponding parts from the straightening material.

A disadvantage of the prior art DE 10 2009 012 929 B3 is that there is no synchronicity between the leveling material feed in the leveling machine and the leveling material feed in the processing device. The continuously straightening and advancing tandem straightening machine of this prior art requires buffering in such a way that a belt loop must be provided between the straightening machine and the machining device in order to compensate for the difference in feed. In particular, this has the disadvantage of a large overall length of the system.

In modern parts production, one goal is to use the raw material used as sparingly as possible in order to receive as little waste as possible.

For the reasons mentioned above and to overcome the disadvantages described above, the object of the present invention is to create a method for straightening strip-shaped or parts-straightening goods, in particular flat parts, with which a space-saving assignment of the straightening process to a subsequent processing device is achieved can be, whereby an exact positioning of the material to be processed is created.

This object is achieved by the features of patent claim 1.

Advantageous refinements of the method are defined by the dependent claims.

Advantageously, the straightening material is carried on after the first straightening unit in that there is no loop of the band-shaped straightening material between the first straightening unit and the second straightening unit, nor between the second straightening unit and the resulting, possibly resulting or escalating during rapid cycle Vibrations in the loop material can be avoided.

In a first alternative embodiment of the invention, the upper and lower rollers of the first straightening unit advantageously have a different diameter than the upper and lower straightening rollers of the second straightening unit. The first straightening unit can thus advantageously be operated as a thick sheet metal machine for straightening material with a greater material thickness, for example in the range from 4 to 10 mm, and the second straightening unit in a thinner range, for example up to approximately 4 mm in material thickness. As a result, the upper and lower rollers of the first straightening unit have a larger diameter than the upper and lower straightening rollers of the second straightening unit.

It is accordingly advantageous that, depending on the requirements for the leveling result or due to the dimension of the leveling material, either the first leveling unit or the second leveling unit or both leveling units are used. This gives the processing company the great advantage of more flexible processing, with the additional advantage that a wider range of straightening material can be processed. In contrast to roller changing systems or cassette changing systems, no mechanical conversion is necessary, and the adjustment to the straightening and positioning task is advantageously carried out by a corresponding setting of the control or regulating device.

Characterized in that the feed speed of the first straightening unit is different, preferably lower, than the feed speed of the second straightening unit, , the tandem straightening machine is able to carry out a combined changing, bending and stretching straightening process. The feed speeds can be set and regulated accordingly with the control or regulating device.

It is also advantageous that the control or regulating device preferably records at least one of the following variables continuously: maximum torque, maximum position deviation, maximum belt tension, speed of the straightening good, acceleration of the straightening good. The straightening process can thus be comprehensively controlled, the detection of the maximum positional deviation furthermore making it possible to set the position more optimally before the processing by the processing device.

It is also advantageous that a measuring sensor of a measuring device is used to detect the positioning of the target material. This means that the positioning of the target material can be recorded immediately, which is a prerequisite for readjusting it if necessary. Advantageously, the control or regulating device is able, in the event of a deviation of the detected position of the conveyed straightening goods from the desired position, to move the straightening goods forwards or backwards into the desired position. This further optimizes the use of the target material.

Advantageously, in the cycle lifting of the upper straightening rollers, only a few tenths of a millimeter are moved with respect to the lower straightening rollers, as a result of which the ventilation state of the respective straightening unit is reached particularly quickly and briefly, which in turn advantageously enables high cycle rates of the processing device.

For a further advantageous optimization of the processing of strip-shaped straightening material, the unwinding movement of the strip-shaped straightening material from a coil is coupled to the feed of the tandem straightening machine. This is preferably done via the control or regulating device. The entire movement process is thus advantageously synchronized from the processing up to and including the machining process in the machining device.

According to the method according to the invention, flexible processing of a wide variety of dimensions of the straightening material is created, both in the form of metal strips unwound from the coil and in the form of parts, in particular flat parts, the processor being able to use the straightening units in a multitude of ways, which means that not only thick sheet straightening, but also precision straightening is possible. Precision straightening is generally understood to mean straightening with the result of a particularly level straightening good.

The use of the first and / or second straightening unit is advantageously controlled by means of the control or regulating device, so that it is not necessary to convert the production line, which leads to a considerably shortened adaptation to different production processes. After a short changeover time, other straightening material can be processed further.

Further details, features and advantages of the present invention will become apparent from the following description of the only one Figure 1 .

One embodiment of a tandem straightening machine 1 is shown in FIG Fig. 1 shown in side view, a view transversely to the direction of travel according to arrow 3 of a band-shaped material 25. The tandem leveler 1 has a first leveling unit 5 and a second leveling unit 7. The first leveling unit 5 has top leveling rollers 9 and bottom leveling rollers 11 and the second leveling unit 7 has top leveling rollers 10 and bottom leveling rollers 12. The two straightening units can be constructed identically, but they are preferably constructed differently. Thus, the first straightening unit 5 can have fewer straightening rollers 9, 11 than the second straightening unit 7, the upper and lower straightening rollers 10, 12 of which can be smaller in diameter for this.

The two straightening units 5 and 7 rest on a common machine bed 13, which in turn rests on support feet 15. Alternatively, the straightening units 5, 7 can also rest on separate machine beds.

The upper straightening rollers 9, 10 are mounted in a manner known per se in an upper roller mill 17 and the upper roller mill 17 is preferably designed to be pivotable according to arrows 19. Of course, the present invention also includes non-swiveling upper roller mills. The two straightening units 5 and 7 are essentially constructed like one straightening machine each, so that the description of further details, in particular with regard to drive and control, is omitted here.

The lower straightening rolls 11, 12 are mounted in a lower straightening roll mill 21, which rests on the machine bed 13 and is connected to it, if necessary. At the inlet of the straightening units 5 and 7 there is a band side guide 23 which serves to guide the band-shaped straightening goods 25 but also flat, in particular tabular, straightening goods laterally.

The leveling rollers serve to advance the leveling material in the respective leveling unit. The feed for discharging the straightening material 25 further advantageously includes an upper driving roller 27 and a lower driving roller 29 per straightening unit 5 or 7, which are located in the direction of travel according to arrow 3 behind the upper and lower straightening rollers 9, 10 and 11, 12 above and below the straightening material 25 are located. The drive rollers 27, 29 serve to drive the straightening good 25 and can be switched on or off depending on the operating situation. The leveling material is mainly driven via the leveling rollers 9, 11, 10, 12, which is why the tandem leveling machine 1 according to the invention is also referred to as a feed leveling machine.

The mode of operation is described as follows: The band-shaped straightening material 25 is threaded into the first straightening unit 5 and passed through, after which it is conveyed to the second straightening unit 7 by means of drive rollers 27 and 29. Then both position controllers are closed and the two straightening units are coupled via a synchronization bus. The physical quantities are continuously measured during the positioning process of the workpiece on the downstream processing device or machine. The physical quantities can include: maximum torque, maximum position deviation, maximum belt tension, speed and / or acceleration of the target material.

The actual values are compared with the target values in the computing module. In the system superimposing both straightening units 5 and 7, the position and moment of the individual straightening units 5, 7 and the movement of the straightening material 25 are monitored. If a measured variable exceeds the specified limit values, the process is stopped. A measuring sensor is used as the measuring means or measuring device, for example in the form of a pair of measuring wheel 33 and counter wheel 34. The measuring sensor is attached to the measuring wheel itself.

When the advanced material 25 has reached its desired position, a torque compensation with superordinate position stabilization acting on the material 25 is initiated in the superimposed system. The straightening good is stopped at the moment when the tool, for example a press ram of the processing device, is immersed in the straightening good. Due to the cycle ventilation of the leveling units 5, 7, the further advance of the leveling material is briefly interrupted until the tool of the processing device releases the leveling material again.

Furthermore, it is particularly advantageous that a defined strip tension can be realized by specifically setting the parameters of straightening unit 5 and straightening unit 7.

With the tandem straightening machine 1 and the method according to the invention it is possible to precisely position the straightening material after straightening on a downstream processing device, such as a punch press, which leads to a considerable improvement in the straightening material utilization. Manufacturing waste can be reduced accordingly. Furthermore, the output of the directed material can be increased significantly.

Reference list

1 -

Tandem leveler

3 -

arrow

5 -

first straightening unit

7 -

second straightening unit

9 -

upper straightening rollers

10 -

upper straightening rollers

11 -

lower straightening rollers

12 -

lower straightening rollers

13 -

Machine bed

15 -

Support feet

17 -

upper straightening roller mill

19 -

Arrows

21 -

lower straightening roller mill

23 -

Hinge side guidance

25 -

band-shaped tobacco

27 -

upper driver role

29 -

lower driver role

31 -

Control or regulating device

33 -

Measuring wheel

34 -

Counter wheel

Claims (9)

1. Method for straightening of strip-like (25) or part products to be straightened, in particular of flat parts, and for cyclic supply to a following processing apparatus or machine, in particular a punch press, a shear or shaping machine, which has the following steps,
   feeding the product to be straightened to a first straightening unit (5) and optionally straightening the product to be straightened in this first straightening unit,
   forwarding the product to be straightened without a loop to a second straightening unit (7) and optionally straightening the product to be straightened in this second straightening unit, forwarding the product to be straightened without a loop to the following processing machine,
   wherein the extent of the forward feed to the following processing machine is controlled by means of an open-loop or closed-loop control device (31), which controls cyclic venting of the straightening units (5, 7) synchronously with the cycling of the following processing apparatus,
   wherein, following closure of the two position controllers of the two straightening units, the two straightening units are coupled via a synchronization bus,
   wherein the product to be straightened is forwarded with position accuracy and with synchronization of the two straightening units by means of a system superimposed on the two straightening units, which comprises a measuring device, in which position and torque of the individual straightening units (5, 7) and the movement of the product to be straightened are monitored,
   wherein, when the product to be straightened has reached its desired position, compensation of the torque acting on the product to be straightened with superimposed position stabilization is initiated in the higher-order system, and
   wherein the use of the first and/or the second straightening unit (5, 7) is controlled by means of the open-loop or closed-loop control device (31) .
2. Method according to Claim 1, characterized in that, depending on the requirements of the straightening result or necessitated by the dimension of the product to be straightened, either the first straightening unit (5) or the second straightening unit (7) or both straightening units (5, 7) is/are used.
3. Method according to Claim 1 or 2, characterized in that the forward feed rate of the first straightening unit (5) relative to forward the feed rate of the second straightening unit (7) can be different, preferably lower.
4. Method according to one of the preceding claims, characterized in that at least one of the following variables is preferably detected continuously by means of the open-loop or closed-loop control device (31): maximum torque, maximum positional deviation, maximum strip tension, speed of the product to be straightened, acceleration of the product to be straightened.
5. Method according to one of the preceding claims, characterized in that a measuring sensor measuring device (33, 34) is used to detect the positioning of the product to be straightened.
6. Method according to one of the preceding claims, characterized in that in the event of a deviation of the detected position of the conveyed product to be straightened from the desired position, the open-loop or closed-loop control device (31) moves the product to be straightened forward or backward into the desired position.
7. Method according to one of the preceding claims, characterized in that during the cyclic venting, the upper straightening rollers (9, 10) are moved only by a few tenths of a millimetre with respect to the lower straightening rollers (11, 12).
8. Method according to one of the preceding claims, characterized in that the unwinding movement of the strip-like product to be straightened (25) from a coil is coupled to the forward feed of the tandem straightening machine (1).
9. Method according to one of the preceding claims, characterized in that two straightening units (5, 7) are used, of which the upper and the lower straightening rollers (9, 11) of the first straightening unit (5) have a different diameter from the upper and the lower straightening rollers (10, 12) of the second straightening unit (7).

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