CORRUGATED INSERT CUTTING APPARATUS AND METHOD
An insert cutting apparatus useable in a production line for producing tubes from shaped sheet-metal strips includes an upper die having a first row of punches, and a lower die having a second row of punches. The first and second rows of punches can form predetermined breaking points in at least one of the shaped sheet-metal strips, and the first and second rows of punches can alternate, so that two punches of the first row of punches have a punch of the second row of punches therebetween.
This application claims priority to German Patent Application No. 10 2010 022 713.7 filed Jun. 4, 2010, the entire contents of which are hereby incorporated by reference herein.
BACKGROUNDThe invention relates to a device, for example as part of a production line for producing tubes from shaped sheet-metal strips. Furthermore, the invention relates to a method for producing tubes.
In DE 10 2007 028 710 A1, perforations or predetermined breaking points are formed following the shaping of sheet-metal strips a, b, c, for simplifying alignment of the perforations or predetermined breaking points in the sheet-metal strips a, b, c (see attached
In DE 196 41 144 A1, in GB 2 203 677 A and in U.S. Pat. No. 2,222,842, notchings are made in a single sheet-metal strip. The sheet-metal strip is still flat, i.e. still not deformed, at the time the notchings are created.
SUMMARYIt is an object of the invention to propose a highly suitable device with which a sheet-metal strip which is already shaped, for example a flat tube inner insert provided with a transverse corrugation, or the flat tube itself, can be perforated or provided with predetermined breaking points without the transverse corrugation or the shaping being destroyed. Furthermore, a method for producing tubes is provided, with which the preparation costs for a production line can be reduced.
In some aspects, the device has at least one row of punches in each case in the upper die and in the lower die. In each case, two punches of one row can have a punch of the other row arranged therebetween. In some embodiments, at least one of the sheet-metal strips is provided with a transverse corrugation, and one row of punches acts on the wave crests and the other row of punches acts on the wave troughs. The device can be part of a production line for producing tubes. However, the device may also serve to produce individual deformed sheet-metal strips which are suitable for purposes other than producing tubes.
Furthermore, the device can also be used to perforate complete flat tubes in order to cut the latter to a predetermined length. In this case, the shaped sheet-metal strip should be interpreted as being the flat tube. The production method according to some embodiments of the invention therefore also makes provision to create perforations or predetermined breaking points into the tube which has already been produced, with at least one row of punches from one side and another row of punches from the opposite side being pierced through the tube, and in each case, two punches of one row have a punch of the other row engaging therebetween. This saves on separate devices and systems for orienting the perforations or predetermined breaking points in the sheet-metal strip. The punches may be cutting or stamping punches. In some embodiments, at the moment of producing the perforations or predetermined breaking points, the abovementioned row of punches in the one (e.g. upper) die together with the row of punches in the other (e.g. lower) die lie exactly in one plane—transversely with respect to the longitudinal direction of the sheet-metal strip—so that separating points which are as rectilinear as possible can be produced at the ends.
In some embodiments, the punches in the rows of punches are designed as needles or similar slim piercing tools. The use of such piercing tools results in the wave crests and the wave troughs being pierced. Short webs can be retained in the wave flanks and on the longitudinal edges of the sheet-metal strip, said webs being separated later, i.e. during the severing of individual flat tubes at the end of the production line.
Provision is furthermore made for the needles of one (e.g. upper) die to pierce the wave troughs and needles of the other (e.g. lower) die to pierce the wave crests. With some embodiments of the device, the wave flanks are subjected to a tensile stress during the piercing of the wave crests/wave troughs, and therefore there need be no concern at the same time that the corrugation will be deformed, even when using tools edge lives that have already been exceeded.
Some embodiments utilize a device having one (e.g. upper) die and the another (e.g. lower) die formed with a matching wave shape, wherein the shaped sheet-metal strip is severed or adequately notched at least in the corrugated region. Accordingly, by means of some embodiments, perforations are produced, and the entire corrugated region of the sheet-metal strip is notched or cut into with this device.
According to some embodiments, the transverse corrugation of the sheet-metal strip is maintained, that is to say, the wave shape does not have to be restored by reworking, as is necessary in the prior art described above.
In some embodiments, a pair of rolls, for example, is used as the dies (e.g. the upper and lower dies).
The device according to some embodiments cooperates with other devices from the prior art described above in such a manner that all of the devices are activated at the same time. In contrast to the prior art shown in
In the first exemplary embodiment of a device P1 according to the present invention, a pair of rollers is used as an upper die O and a lower die U, as can best be seen from
In other embodiments (not shown), rather than a pair of rollers, use is made of two rams which are vertically movable, for example, by means of eccentric shafts and to which rows of punches are fastened, as described below. The abovementioned pair of rolls or the device P1 can be part of a production line (shown in
According to
The dimensions D, d (
In the exemplary embodiment according to
In contrast to the exemplary embodiment shown in
If the device P1 according to
Various features and advantages of the invention are set forth in the following claims.
Claims
1.-9. (canceled)
10. A device useable as part of a production line for producing tubes from shaped sheet-metal strips, the device comprising:
- an upper die having a first row of punches; and
- a lower die having a second row of punches;
- wherein the first and second rows of punches form predetermined breaking points in at least one of the shaped sheet-metal strips, and
- wherein a punch of the second row of punches engages between two punches of the first row of punches.
11. The device according to claim 10, wherein the predetermined breaking points comprise perforations.
12. The device according to claim 10, wherein at least one of the shaped sheet-metal strips has a transverse corrugation defining a plurality of wave crests and wave troughs, and wherein the first row of punches acts in the wave crests and the second row of punches acts in the wave troughs.
13. The device according to claim 10, wherein the two punches of the first row of punches each include a piercing tool.
14. The device according to claim 13, wherein the piercing tool includes a perforation needle.
15. The device according to claim 13, wherein the punch of the second row of punches includes a piercing tool.
16. The device according to claim 15, wherein the piercing tool includes a perforation needle.
17. The device according to claim 15, wherein the piercing tools of the two punches of the first row of punches are spaced apart a first distance, such that the piercing tools of the two punches of the first row of punches have the piercing tool of the punch of the first row of punches therebetween.
18. The device according to claim 15, wherein at least one of the shaped sheet-metal strips has a transverse corrugation defining a plurality of wave troughs and wave crests, and wherein the piercing tools of the first row of punches pierce the wave troughs and the piercing tool of the second row of punches pierces the wave crests.
19. The device according to claim 10, wherein the upper die includes a first roll and the lower die includes a second roll.
20. The device according to claim 19, wherein the first roller defines an outer surface, the first row of punches extending across the outer surface, such that rotation of the first roller moves the first row of punches into and out of engagement with the at least one the shaped sheet metal strips.
21. A production line for producing tubes from a first shaped endless sheet-metal strip, and a second shaped endless sheet-metal strip, the production line comprising:
- a first device including an upper die having a first row of punches; and a lower die having a second row of punches; wherein the first and second rows of punches form predetermined breaking points in the first shaped sheet-metal strip, and wherein a punch of the second row of punches engages between two punches of the first row of punches;
- a second device positioned at a common location along the production line with the first device, the second device operable to form predetermined breaking points in the second shaped endless sheet-metal strip;
- a first section upstream of the first device and the second device, the first section operable to shape the first and second shaped endless sheet-metal strips; and
- a second section downstream of the first device and the second device, the second section operable to combine the first and second shaped endless sheet-metal strips,
- wherein the first device and the second device work simultaneously to form the predetermined breaking points.
22. The device according to claim 21, wherein the predetermined breaking points comprise perforations.
23. A device useable as part of a production line for producing tubes from shaped sheet-metal strips, the device comprising:
- an upper die having a first wave shape; and
- a lower die having a second wave shape,
- wherein at least one of the shaped sheet-metal strips has a transverse corrugation substantially matching the first wave shape and the second wave shape, and
- wherein the upper die and the lower die produce predetermined breaking points in at least one of the shaped sheet-metal strips in the transverse corrugation without the corrugation being damaged.
24. The device according to claim 23, wherein the predetermined breaking points comprise perforations.
25. The device according to claim 23, wherein the upper die includes a knife and the lower die includes a roller.
26. A method for producing tubes on a production line having rolls, the method comprising:
- shaping sheet-metal strips;
- combining the sheet-metal strips to form a tube;
- after shaping and combining, forming predetermined breaking points in the tube by contacting a first side of the tube with at least two punches from a first row of punches and contacting a second side of the tube with at least one punch from a second row of punches, wherein the at least two punches of the first row of punches have the at least one punch from the second row of punches therebetween.
27. The method according to claim 26, further comprising severing individual tubes from the tube, wherein the tubes are severed along the predetermined breaking points.
28. The method according to claim 26, wherein forming predetermined breaking points including forming perforations.
29. The method according to claim 26, wherein contacting the tube first side includes inserting the two punches into respective wave troughs of the tube and wherein contacting the tube second side includes inserting the one punches into a wave crest of the tube.
Type: Application
Filed: Jun 3, 2011
Publication Date: Dec 8, 2011
Inventors: Manfred Lenkner (Stuttgart), Andreas Laug (Reutlingen)
Application Number: 13/153,053
International Classification: B21D 31/02 (20060101);