EP0099413B1 - Method of straightening elongated round material and apparatus therefor - Google Patents

Description

According to the preamble of claim 1, the invention relates to a method for straightening elongated round material by moving forward in the longitudinal direction and simultaneously rotating about the longitudinal axis and thereby briefly deflecting from the inlet straight in a straightening sheet containing straightening nozzles while exceeding the flow limit.

Furthermore, the invention relates, according to the preamble of claim 3, to a device for carrying out this method for straightening elongated round material with at least one drive device for moving the round material axially and rotationally and at least one straightening sheet, each consisting at least of a deflecting straightening nozzle, an outlet straightening nozzle and a device for introducing the round material into the deflection straightening nozzle, and at least one device having takeover elements for taking over the round material behind an outlet straightening nozzle.

Methods for straightening elongated round material of the type described in the introduction have become known, for example, from DE-A-29 37 635 or from DE-A-30 20 536.

Devices of the type described at the outset for carrying out such methods have also become known from the cited documents.

The technology of straightening elongated round material has been known for a long time. The last improvements in the judging result were achieved with the measures taught in the writings mentioned at the beginning. Despite the well-known straightening technology, it has so far not been possible to satisfactorily straighten the beginning and end of a round material bar to be straightened. The known straightening methods and straightening devices produce areas of unsatisfactory straightness at both ends of the bar to be straightened, so that the user of the straightened bars is often forced to cut off the unsatisfactorily directed ends of the bar. Apart from the additional work step required for this, this also results in a relatively large loss of material.

In DE-A-16 27 612 a straightening process of the prior art is shown in progressive sequence in FIGS. 1 to 3. The figures mentioned schematically show the usual three straightening nozzles of a straightening sheet. Here, Figure 1 shows the inlet situation of the round material to be straightened. The round material 1 entering through the directional nozzle 2 in the direction of entry is deflected upwards by the deflecting directional nozzle 4 and, with its front end, abuts the insertion funnel of the outlet nozzle 3. FIG. 2 shows that the outlet nozzle 3 has taken over the round material 1 to be straightened at its beginning and bent it in the opposite direction again for forwarding and taking over by further machine elements. In the prior art, these further machine elements are either further straightening bends or a drive device arranged at the end. This then takes over the material to be straightened again so that the area taken over flows again in the direction of entry, as can be clearly seen in FIG. 3. It is exactly this approach that creates the disadvantages described above.

With the US-A-2 318 019 a device for unwinding and straightening wire wound on bobbins is known, in which the wire is first threaded into a bending device with the approximate coil curvature and then with a sufficiently large curvature in the opposite direction, but in same level, is brought out again. However, this is only a rough alignment, which only takes place in one plane and also leaves undesirable stresses in the material. It is not possible to straighten elongated round material in all possible levels of unevenness.

The invention is therefore based on the object of proposing a straightening method with which a better straightening result is achieved at the ends of the round material rods to be straightened.

According to the invention, this object is achieved in a method of the type described at the outset in that the deviation from the infeed line which is forced in the straightening sheet by deflection is maintained approximately as the direction of exit from the straightening sheet. Surprisingly, this measure has resulted in practical testing that only very small straightening errors occur at the ends of the round material rods to be straightened and these only extend over a much shorter range. The straightening error that is still present is so small that it is often no longer a hindrance in the further processing of these rods, for example by centerless grinding, but is instead eliminated by the grinding operation. In such cases, there is no longer any waste piece at all on the round material rods to be straightened.

According to an embodiment of the method, it is proposed that the direction of exit of a preceding straightening sheet is approximately the direction of entry for a subsequent straightening sheet. As is known, straightness errors of different wavelengths can be detected and directed by using several different straightening sheets. It is advisable to arrange a subsequent straightening sheet so that it can take over the outgoing round material in the outflow direction without any constraint. Here it can be advantageous as after the following straightening sheet to arrange a straightening sheet with straightening straightening nozzles so that ever shorter ripples are detected in the continuous straightening process. If the successive straightening sheets are each arranged according to the teaching of the invention, the final error can thereby be reduced further and further.

Another object of the invention is to propose a device with which the method according to the invention can be carried out.

According to the invention, this object is achieved in a device of the type described in the introduction in that each device for taking over the round material behind an outlet straightening nozzle is aligned or can be aligned at least with its take-over elements in such a way that the round material emerging from the outlet straightening nozzle under the deviation from that required in the straightening sheet Inlet straight line is adopted without significant changes in direction. With such an alignment of the transfer elements, it is easily possible to maintain the deflection from the inlet straight line, which is forced in the straightening sheet, as the exit direction from the straightening sheet.

According to an embodiment of the device, it is proposed that at least one device for taking over the round material is formed by a further straightening sheet comprising straightening nozzles. This makes it possible to combine the means for the formation of the directional sheet and the means for the formation of the device for taking over the round material in a sequence of straightening sheets, whereby the overall construction effort can be reduced.

According to a further embodiment of the device, it is proposed that, in a sequence of several straightening sheets, one inlet straightening nozzle of the following straightening sheet forms the takeover element. This makes it possible to save a special takeover element in front of the respective straightening sheets.

A further embodiment of the device provides that at least the device for taking over the round material following the first straightening sheet is arranged on a base which changes in position. This makes it possible to easily adapt the device for taking over the round material to different discharge directions.

According to a further embodiment of the device, it is also provided that the outlet straightening nozzle of the first straightening sheet is arranged on the same position-changing base. In this way it is achieved that the device for taking over the round material automatically adapts to a change in the outlet direction.

A further embodiment of the device provides that the deflecting straightening nozzle of the first straightening sheet is also arranged on the same position-changing base. In this way, the most important elements for creating the straightening sheet and for taking over the leaking round material are combined in a common machine assembly.

Again according to an embodiment of the device, it is proposed that the base can be pivoted about an axis perpendicular to the surface in which the round material curved in the straightening sheet lies. In this way, it is possible to adapt the device to different requirements by changing the curvature of the straightening sheet. At the same time, all components essential to the invention remain in the relative position to one another that is required to carry out the method according to the invention.

According to another embodiment of the device, it is provided that an aligned or orientable device for taking over the round material is arranged at least after the last outlet straightening nozzle of all straightening sheets. This makes it possible, for example, to carry out a straightening process of a conventional type in a plurality of straightening sheets which are conventionally connected or superimposed one after the other, which is then followed by the method according to the invention by the corresponding device for taking over the round material in a corresponding orientation. This makes it possible to structurally supplement existing straightening machines so that the method according to the invention can also be carried out with these machines.

According to another embodiment of the device, it is provided that the deflecting straightening nozzle of at least the first straightening sheet can be pivoted about its vertical axis independently of the base. This makes it possible to achieve fine adjustment of the straightening sheet by independently pivoting the deflecting straightening nozzle and thus by shifting the point of contact between the straightening nozzle and the material. In narrow areas, this can also influence the direction of discharge of the round material.

According to another embodiment of the device, it is again provided that the outlet straightening nozzle of at least the first straightening sheet can be pivoted about its vertical axis independently of the base. This also applies to the fine-tuning of the straightening sheet and the influencing of the outlet direction of the round material.

A further embodiment of the device provides that the device for introducing the round material of at least the first straightening sheet is arranged on a stationary base. This minimizes the construction work for the moving parts and clearly separates the functional groups.

According to another embodiment of the device, it is also provided that the inlet straightening nozzle of at least the first straightening sheet is arranged on an immobile base. This results in a more Bauvereinfachun is ^g achieved, which still has all the advantages of the invention.

Finally, according to a further embodiment of the device, it is provided that the deflecting straightening nozzle of the first straightening sheet is also arranged on the immovable base. This combination offers the possibility of inexpensively retrofitting existing straightening machines so that the method according to the invention can be carried out.

The invention will now be explained in more detail with reference to the accompanying drawings, which show an embodiment.

• Figur 1 Prinzipdarstellung der erfindungsgemäßen Einrichtung in Draufsicht mit horizontalem Schnitt durch die Richtdüsen
• Figur 2 Darstellung nach Figur 1, jedoch mit Einlaufrichtbogen für kurzwellige Geradheitsabweichungen

Show it :

• Figure 1 schematic representation of the device according to the invention in plan view with a horizontal section through the directional nozzles
• FIG. 2 representation according to FIG. 1, but with an inlet straightening curve for short-wave straightness deviations

On a stationary base 13, a drivable pair of friction wheels 16 is arranged in the usual and known manner in the case of straightening machines of the generic type, which ensures the axial and rotational movement of the round material 20 to be straightened. The round material 20 is moved forward in the direction of arrow 21. Arrow 21 thus indicates the direction of transport of the round material 20.

When the round material 20 leaves the friction wheel pair 16 in the transport direction, it is taken over by a straightening nozzle 18 (FIG. 1) and threaded into the inlet straightening nozzle 15. The inlet straightening nozzle 15 is fixedly arranged on the immobile base 13. In the arrangement described, the straightening nozzle 18 fulfills the task of reliably introducing the round material 20 into the inlet straightening nozzle 15 of the straightening sheet 1. It is entirely possible to arrange the straightening nozzle 18 as an outlet straightening nozzle of a straightening curve 19 (FIG. 2). In this straightening curve 19, the individual straightening nozzles are then arranged as closely as possible to one another and have only a relatively small radial offset relative to one another. The straightening sheet 19, which can be arranged on the immobile pedestal 13, only serves to straighten small, short-wave oddities. Here, the relative arrangement of the straightening sheet 19 to the friction wheel pair 16 can be conventional, so that the outlet direction is the same or at least parallel to the inlet direction. However, it is also possible to arrange the components or straightening sheets following the straightening sheet 19 such that the outlet direction from the straightening nozzle 18 of the straightening sheet 19 is maintained and is taken over by the next straightening nozzle, for example the inlet straightening nozzle 15 of the straightening sheet 1. In the exemplary embodiment, the relative arrangement of straightening sheet 19 and friction wheel pair 16 is provided in a conventional manner for the sake of simplicity, so that the round material 20 emerging from the straightening nozzle 18 of the straightening sheet 19 is first bent back by the inlet straightening nozzle 15 in the direction of the arrow 21.

However, as the exemplary embodiment according to FIG. 1 shows, the round material 20 can in principle be completely omitted in the straightening sheet 19.

The assembly 14 or 14a arranged on the immovable pedestal 13 in its entirety forms the device for introducing the round material 20 into the inlet straightening nozzle 15 of the straightening sheet 1. In the exemplary embodiment, the inlet straightening nozzle 15 is fixedly arranged on the immovable pedestal 13. The straightening sheet 1 is the main straightening sheet in which the round material 20 is straightened with the desired tolerance. For this purpose, the round material 20 is moved further out of the inlet straightening nozzle 15 in the direction of the arrow 21 and taken over by the deflecting straightening nozzle 10, which in the exemplary embodiment is arranged on the base 9 which changes in position, and is guided further into the outlet straightening nozzle 6. The outlet straightening nozzle 6 is also arranged on the base 9 which can change its position. In the exemplary embodiment, the arrangement of the deflecting straightening nozzle 10 and the outlet straightening nozzle 6 on the position-changing base is such that the round material 20 to be straightened comes into contact with it approximately tangentially to the narrowest cross section of the mentioned straightening nozzles, as can be seen in FIGS. 1 and 2. This type of contact between the round material 20 to be straightened and the aforementioned straightening nozzles is particularly advantageous, but is not absolutely necessary. In order to achieve the described advantage, the deflecting directional nozzle 10 must be arranged on the base 9 so that it can rotate about its vertical axis independently of the position-changing base 9.

Since, in the exemplary embodiment, the position-changing pedestal 9 can be pivoted, as indicated by arrow 22, it is sufficient if the outlet directional nozzle 6 is rigidly arranged on the position-changing pedestal 9. Due to the pivotability of the position-changing base 9, the outlet straightening nozzle 6 always maintains the desired position.

When the round material 20 to be straightened leaves the outlet straightening nozzle 6, it has undergone a deflection 3 from the inlet straight line 2 (FIG. 2) and has now become the directed round material 7. So that the unpleasant end defects described at the beginning do not occur, it must now be ensured that the round material 7 emerging from the outlet straightening nozzle 6 and now directed can continue to flow in the outlet direction 4 and is not bent back into or parallel to the inlet direction by subsequent directional nozzles The arrow 21. In the exemplary embodiment, the directional round material 7 is taken over from the inlet straightening nozzle 8 of a further straightening sheet 5 arranged on the base 9, which is variable in position. Behind the straightening bow 5, a drivable friction wheel pair 17 is again provided in a known manner for the further transport of the straightened round material 7 . The directed round material 7 can each but also without the interposition of a further straightening sheet 5 immediately after the outlet straightening nozzle 6 by the friction wheel pair 17.

The addition of a further straightening sheet 5 has the advantage, however, that small, short-wave unevenness can be re-aligned here. Here, the arrangement can be such that the friction wheel pair 17 is pivoted slightly so that it takes over the round material 7 running out of the straightening sheet 5 without a new change of direction. This would then be an arrangement according to the present invention. Since the amounts still to be straightened in straightening sheet 5 are generally smaller than the required straightness tolerance of the entire round material bar to be straightened, such an arrangement is not absolutely necessary. It is entirely possible to arrange the pair of friction wheels 17 in such a way that the round material flowing out of the straightening sheet is brought back in the same direction as the round material 7 entering the straightening nozzle 8 of the straightening sheet 5. The resulting end bend is so small in size that it is small it can be accepted. This is because the main straightening work was carried out in straightening sheet 1 and straightening sheet 5 is designed so that only very small, short-wave deviations in straightness are straightened. In an arrangement according to the exemplary embodiments shown, the straightening sheet 5 in combination with the friction wheel pair 17 can therefore be seen in its entirety as a device for taking over the round material behind the straightening sheet 1.

It should be particularly pointed out that the pivotable arrangement of the position-changing base 9 is not the only possible design of a straightening machine for executing the straightening method according to the invention. For example, it is entirely conceivable to arrange the entire device 14 or 14a and the straightening sheet 1 together on a fixed machine frame. In this case, the straightening nozzles 6, 10 and 15 of the straightening sheet 1 can then be pivoted and displaced radially in a conventional manner and, if appropriate, can also be rotated additionally about the vertical axis. It is then only necessary to align the devices following the straightening sheet 1 in such a way that they can take over the round material emerging from the straightening sheet 1 without constraint. In this case, these take-over devices can either be fixed in the required take-over position for a very specific and known application, or they can be pivotable or radially displaceable on their or with their base, or both to adapt to the necessary outlet direction. It is irrelevant here whether the devices that follow straightening sheet 1 are further straightening sheets for straightening minor unevenness or whether they are other devices.

However, it is also conceivable to provide a plurality of straightening bends one behind the other in the arrangement according to the invention, so that a kind of sinusoidal curve is produced for all the straightening nozzles of all the straightening bends connected in series. It is only important that after leaving a previous directional sheet, entry into the subsequent directional sheet is casual, i.e. H. done while maintaining the exit direction. It is also conceivable to combine straightening sheets connected in series in this way to form a superordinate straightening sheet, with which particularly long-wave oddities can then be straightened.

The method according to the invention and the device according to the invention enable for the first time significant improvements in the straightening result at the respective ends of the bars to be straightened.

Claims (15)

1. Method for straightening drawn round stock (20) by moving the said stock forward in lengthwise direction (21) and simultaneously rotating the stock about the longitudinal axis and thereby briefly deflecting the stock from a straight line (2) in a straightening arc (1) containing straightening dies whereby the yield point of the stock is exceeded, characterized in that the deflection from the straight line (2) enforced in the straightening arc is approximately kept as the exit path (4) out of the straightening arc (1).

2. Method according to claim 1 characterized in that the exit path of a preceding straightening arc (1) is approximately the entry path for a following straightening arc (5).

3. Apparatus for carrying out the method according to claims 1 and 2 for straightening drawn round stock (20) with at least one drive means (17, 16) for advancing the stock (20) axially and rotating and at least one straightening arc (1) each consisting of at least a deflecting die (10), an exit die (6) and a device (14, 14a) for introducing the stock into the deflecting die as well as a device having at least one receiving element for receiving the round stock behind an exit die (6) characterized in that each device (5, 17) for receiving the round stock (20) behind the exit die (6) is oriented or can be oriented behind an exit die at least by its receiving elements (8, 17) so that the round stock (7) leaving the exit die (6) with the deflection from the straight line enforced by the straightening arc (1) is received without a mentionable change of direction.

4. Apparatus according to claim 3 characterized in that at least a device for receiving the round stock is formed by a further straightening arc (5) containing straightening dies.

5. Apparatus according to claims 3 and 4 characterized in that in a series of more straightening arcs (15) an entry die (8) forms the receiving element of the following straightening arc (5) respectively.

6. Apparatus according to claims 3 to 5 characterized in that at least the device for receiving the round stock (7) behind the first straightening arc (1) is mounted on a movable frame (9).

7. Apparatus according to claim 6 characterized in that the exit die (6) of the first straightening arc (1) is mounted on the same movable frame (9).

8. Apparatus according to claim 7 characterized in that also the deflecting die (10) of the first straightening arc (1) is mounted on the same movable frame (9).

9. Apparatus according to claims 6 to 8 characterized in that the frame is pivotable about an axis (11) perpendicular to the plane in which the curved round stock (7) lies in the straightening arc (1).

10. Apparatus according to claim 3 characterized in that an adjusted or adjustable device for receiving the round stock (7) is arranged at least behind the last exit die of all straightening arcs.

11. Apparatus according to claims 3 to 10 characterized in that the deflecting die (10) of at least the first straightening arc (1) is pivotable independently of the frame (9).

12. Apparatus according to claims 3 to 10 characterized in that the exit die (6) of at least the first straightening arc (1) is pivotable about its axis independently of the frame (9).

13. Apparatus according to claims 3 to 10 characterized in that the device for introducing the round stock (7) of at least the first straightening arc (1) is mounted on an immovable frame (13).

14. Apparatus according to claims 3 to 7 characterized in that the entry die (15) of at least the first straightening arc (1) is mounted on an immovable frame (13).

15. Apparatus according to claims 3 to 7 and 9 to 14 characterized in that the deflecting die (10) of the first straightening arc (1) is also mounted on an immovable frame (13).

Images