U.S. patent application number 16/351580 was filed with the patent office on 2019-09-26 for method for machining a sheet-metal profile.
The applicant listed for this patent is BENTELER AUTOMOBILTECHNIK GMBH. Invention is credited to Guenter FORTMEIER, Matthias KOERNER.
Application Number | 20190291160 16/351580 |
Document ID | / |
Family ID | 65321904 |
Filed Date | 2019-09-26 |
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United States Patent
Application |
20190291160 |
Kind Code |
A1 |
FORTMEIER; Guenter ; et
al. |
September 26, 2019 |
METHOD FOR MACHINING A SHEET-METAL PROFILE
Abstract
The invention relates to a method for machining a sheet-metal
profile 1, wherein the sheet-metal profile 1 is trimmed in a
multi-stage cutting process and a cutting edge 2 is produced. Here,
pre-cutting is firstly performed on the sheet-metal profile 1,
whereby a free space 3 is generated. Stamping of the sheet-metal
profile 1 is subsequently performed, wherein the thickness d of the
sheet-metal profile 1 along the cutting edge 2 to be produced is
reduced. Subsequently, the cutting finishing of the sheet-metal
profile 1 is performed, wherein, in particular, cutting is
performed in the opposite direction to the stamping of the outline
of the finished contour, and the cutting edge 2 is generated.
Inventors: |
FORTMEIER; Guenter;
(Delbrueck, DE) ; KOERNER; Matthias; (Schloss
Holte-Stukenbrock, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BENTELER AUTOMOBILTECHNIK GMBH |
Paderborn |
|
DE |
|
|
Family ID: |
65321904 |
Appl. No.: |
16/351580 |
Filed: |
March 13, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B21D 28/16 20130101;
B23D 31/002 20130101; B21D 28/10 20130101; B21D 35/001 20130101;
B23D 15/08 20130101 |
International
Class: |
B21D 35/00 20060101
B21D035/00; B21D 28/10 20060101 B21D028/10; B21D 28/16 20060101
B21D028/16 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 20, 2018 |
DE |
10 2018 106 520.5 |
Claims
1-6. (canceled)
7. A process of machining a sheet-metal profile, the process
comprising: trimming the sheet-metal profile in a multi-stage
cutting process forming a cutting edge, pre-cutting a free space in
the sheet-metal profile, stamping of the free space formed in the
precutting of the sheet-metal profile, wherein a thickness of the
sheet-metal profile along the cutting edge is reduced by the
stamping, and cutting finishing the sheet-metal profile, wherein
the cutting edge is formed such that the stamping and the cutting
finishing are performed in opposite directions.
8. A process according to claim 7, wherein the pre-cutting and the
stamping are performed in opposite directions.
9. A process according to claim 7, wherein the pre-cutting is
performed along a pre-cutting edge, wherein the pre-cutting edge
has a spacing to the cutting edge, which spacing is dimensioned to
be between 30% and 75% of the thickness of the sheet-metal
profile.
10. A process according to claim 7, wherein the thickness of the
sheet-metal profile is reduced by 15% to 50%, due to the
stamping.
11. A process according to claim 7, wherein during the stamping, a
portion of the sheet-metal profile in a stamping zone is molded
into the free space substantially at right angles with respect to
the stamping direction.
12. A process according to claim 7, wherein the sheet-metal profile
is deformed before, during and after the cutting process.
13. A process according to claim 7, wherein the thickness of the
sheet-metal profile is reduced by 20% to 40%, due to the
stamping.
14. A process according to claim 7, wherein the thickness of the
sheet-metal profile is reduced by 30%, due to the stamping.
15. A process according to claim 9, wherein the spacing is
dimensioned to be between 40% and 60% of the thickness of the
sheet-metal profile.
16. A process according to claim 9, wherein the pre-cutting is
performed along the pre-cutting edge, wherein the pre-cutting edge
has the spacing is dimensioned to be between 45% and 55% of the
thickness of the sheet-metal profile.
17. A process according to claim 9, wherein the pre-cutting is
performed along the pre-cutting edge, wherein the pre-cutting edge
has the spacing is dimensioned to be 50% of the thickness of the
sheet-metal profile.
Description
RELATED APPLICATIONS
[0001] The present application claims priority of German
Application Number 10 2018 106 520.5 filed Mar. 20, 2018, the
disclosure of which is hereby incorporated by reference herein in
its entirety.
FIELD
[0002] The disclosure relates to a method for machining a
sheet-metal profile, wherein the sheet-metal profile is trimmed in
a multi-stage cutting process.
BACKGROUND
[0003] In the deformation of metal sheets, shear cutting is an
established technique. In this method, a characteristic roughness
and a burr are formed, because short cut and relatively long break
portions form at the cutting edge. These reduce the capability of
the components or sheet-metal profiles to withstand expansions or
fluctuating loads.
[0004] Another method is countercutting. Here, the sheet-metal
profile is, in a first step, subjected to initial cutting on a
first side at the desired cut edge. In the second step, a second
cutting punch is used from the opposite side. Said cutting punch
then severs the metal in the opposite direction. As a result of the
first stamping or initial cutting, a material accumulation forms on
the opposite side, whereby the second cutting punch does not make
contact in the correct manner with the metal sheet to be cut. As a
result, the desired intense increase of the cut stress at the cut
edge does not arise.
[0005] DE 1 0 2008 028 242 A1 describes a method and a device for
the sheer cutting of sheet-metal components. Here, before the shear
cutting, the sheet-metal component is locally warmed in the region
of the cut edge by means of a laser beam in order to lower the
hardness. In this way, the cutting tool is preserved, in the case
of press-hardened steels.
[0006] The prior art also includes a method for producing a
sheet-metal molded part as per DE 10 2005 051 403 B3. In said
document, before or during the hot working, a stamping is
introduced into cut zones in the workpiece, which stamping reduces
the wall thickness in the cut zone. After the hot working, trimming
is performed on the hardened component within the stamping. This
measure also contributes to facilitating the trimming, like hard
cutting, or making this possible in the first place.
[0007] Within the scope of WO 2013/167232 A1, a method for dividing
up a workpiece is disclosed, and a device suitable for this purpose
is specified. Here, into the workpiece to be divided up, a notch
geometry is introduced at least on one side along a parting line
with plastic deformation, which notch geometry ends in the
workpiece, and the workpiece is subjected to shear cutting along
the parting line. It is sought in this way to generate a burr-free
cut or break surface.
[0008] In the method discussed in WO 02/081116 A1, it is the
intention for burr-free cutting of metal sheets to be performed by
virtue of the metal sheet initially being merely pressed along the
desired cut line by means of a stamping punch and a stamping die
without relative bending thereof so as to form a step in a first
direction, and only then being fully severed using a cutting punch
and a cutting die in the opposite direction. A cutting gap is
present between the cutting punch and the cutting die. The stamping
punch and the stamping die are intended to overlap one another with
the aim of pressing the metal sheet along the desired cutting line
to an only small residual thickness. By means of the small residual
thickness, it is then possible in the second method step for a
relatively large cutting gap to be set between the cutting punch
and the cutting die, whereby it is sought to reduce the risk of
collision between the cutting punch and the cutting die.
[0009] Within the scope of JP 2008 229710 A, the formation of holes
in a blank is discussed. Here, circular stamping using a first
punch is performed, following which a second punch with a smaller
diameter than the stamping is used to punch the hole in the
opposite direction. This involves countercutting.
[0010] A similar approach is also disclosed in EP 2 062 664 B1.
[0011] JP H06-344 049 A discloses a method in which pre-cutting is
performed on a sheet-metal profile, whereby a free space is
generated. Subsequently, stamping of the sheet-metal profile is
performed, wherein the thickness of the sheet-metal profile along
the cutting edge to be produced is reduced. Subsequently, the
cutting finishing of the sheet-metal profile is performed, wherein
the cutting edge is generated.
SUMMARY
[0012] The disclosure is based on the object of specifying a method
for machining a sheet-metal profile, in which the sheet-metal
profile is trimmed and a burr-free cutting edge which can be
subjected to static and dynamic loading is produced, wherein the
method can be integrated into a standard deformation process.
[0013] In the method according to one or more embodiments of the
disclosure for machining a sheet-metal profile, the sheet-metal
profile is trimmed in a multi-stage cutting process, wherein a
cutting edge is produced. For this purpose, pre-cutting is firstly
performed on the sheet-metal profile, whereby a free space is
generated. Stamping of the sheet-metal profile is subsequently
performed, wherein the thickness of the sheet-metal profile along
the cutting edge to be produced is reduced. Subsequently, the
cutting finishing of the sheet-metal profile is performed, wherein
the cutting edge is generated. Here, the outline of the finished
contour is cut.
[0014] The method according to one or more embodiments of the
disclosure can be applied to different sheet-metal profiles and
various components, for example structural components (for example
transverse connectors) or chassis components (for example torsional
profiles, links).
[0015] In the context of one or more embodiments of the disclosure,
a sheet-metal profile is to be understood to mean both a planar
sheet-metal blank and also a pre-shaped sheet-metal blank, a
semifinished part or a shaped molded component. The sheet-metal
profile is made of metal, like steel or of light metal.
[0016] Compared to known approaches, the edges of the workpiece or
of the sheet-metal profile are rounded, and there is no burr. A
sheet-metal profile is provided which has a burr-free cutting edge
which can be subjected to high static and dynamic loading. By means
of the absence of burrs on both sides at the one or more cutting
edges, the service life of the components is greatly improved.
Furthermore, the assembly of such sheet-metal profiles, or of
components produced therefrom, is improved. By contrast to shear
cutting, the rough break zone is relocated into the middle part
which is subjected to lower stresses, and is additionally reduced.
The cutting edge produced according to one or more embodiments of
the disclosure withstands greater expansions, whereby no cracks
form in the event of further deformations. Greater numbers of
dynamic load alterations can also be withstood.
[0017] According to one or more embodiments of the disclosure, the
stamping and cutting finishing are performed in opposite
directions, that is to say the direction of action during the
stamping and the direction of action during the cutting finishing
are from opposite sides in relation to the plane of the sheet-metal
profile.
[0018] The pre-cutting and the stamping in one or more embodiments
are also performed in opposite directions.
[0019] The pre-cutting is performed along a pre-cutting edge. The
pre-cutting edge has a spacing to the cutting edge to be produced,
that is to say the final cutting edge. The spacing is dimensioned
to be between 30% and 75% of the sheet-metal thickness. This means
that the spacing of the pre-cutting edge to the cutting edge to be
produced lies between 0.3 and 0.75 times the sheet-metal thickness.
The spacing amounts to 40% to 60% of the sheet-metal thickness. A
spacing between 45% and 55% of the sheet-metal thickness is
considered to be suitable for practical purposes. In at least one
embodiment provides for the spacing of the pre-cutting edge to the
final cutting edge to be 50% of the sheet-metal thickness of the
sheet-metal profile. This means that the spacing amounts to 0.5
times the sheet-metal thickness.
[0020] A further aspect of the disclosure provides for the
thickness of the sheet-metal profile to be reduced by 15% to 50%,
or by 20% to 40%, during the stamping. A reduction of the
sheet-metal thickness by 30%, that is to say by 0.3 times the
sheet-metal thickness.
[0021] During the stamping, the material in the region of the
stamping zone is plastically deformed or stamped between the
pre-cutting edge and the cutting edge to be produced. The material
in the stamping zone to be is molded into the free space
substantially at right angles, that is to say at 90.degree., with
respect to the stamping direction. This measure assists the
subsequent cutting finishing.
[0022] As already mentioned, the cutting process according to one
or more embodiments of the disclosure can be integrated into a
standard deformation process. Accordingly, the sheet-metal profile
can be deformed before, during or after the cutting process.
[0023] With the method according to one or more embodiments of the
disclosure for machining a sheet-metal profile, and the cutting
process used here, the formation of a cut burr can be avoided.
Finish machining processes formed after the cutting process in
order to remove cut burrs can be omitted, or are substantially
minimized. Grinding inspections of the cutting edges produced
according to one or more embodiments of the disclosure have shown
that outer smooth cut portions with cutting edges almost at right
angles are obtained.
[0024] The method according to one or more embodiments of the
disclosure is in regard to processing times, productivity and also
energy efficiency. The method and the sheet-metal profiles or
molded components produced in accordance with the method are
distinguished by their cut surface quality.
[0025] In the machining of the sheet-metal profile and the cutting
process according to one or more embodiments of the disclosure, it
is possible to produce closed cutting edges or cut lines and open
cutting edges or cut lines. With the cutting process, it is
possible to perform both hole formation and trimming, cutting-out
or notching on a sheet-metal profile.
[0026] The disclosure will be described in more detail below on the
basis of at least an exemplary embodiment illustrated in the
drawings. FIGS. 1 to 3 illustrate three method stages of a cutting
process on a sheet-metal profile.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] For an understanding of embodiments of the disclosure,
reference is now made to the following description taken in
conjunction with the accompanying drawings, in which:
[0028] FIG. 1 shows the pre-cutting of a sheet-metal profile;
[0029] FIG. 2 shows the subsequent stamping at the cut contour of
the sheet-metal profile, and
[0030] FIG. 3 shows the cutting finishing of the sheet-metal
profile.
[0031] In the figures, the same reference numerals are used for
identical or similar components, even though a repeated description
is omitted for reasons of simplification.
DETAILED DESCRIPTION
[0032] The method according to one or more embodiments of the
disclosure for machining a sheet-metal profile 1 includes a
three-stage cutting process for generating at least one
cutting-edge 2, in the course of the production of holes, recesses
and similar trimming contours on the sheet-metal profile 1. A
sheet-metal profile 1 may be a planar sheet-metal blank, a
preformed sheet-metal blank, a semifinished part or a fully shaped
molded component, composed in each case of metal.
[0033] The cutting process comprises the process steps: [0034]
pre-cutting (in this regard, see FIG. 1), [0035] stamping (in this
regard, see FIG. 2), and [0036] cutting finishing (in this regard,
see FIG. 3).
[0037] Pre-cutting: to create a free space 3 for the subsequent
"stamping" operation, trimming is performed, using standard
methods, with a spacing a of 0.5 times the sheet-metal thickness d
in relation to the (final) cutting edge 2 to be produced.
[0038] Stamping: the outline of the finished contour is stamped to
a depth of 0.3 times the sheet-metal thickness. The displaced
material flows in this case at an angle of 90.degree. into the free
space 3 produced previously. No accumulations of material form.
[0039] Cutting finishing: in the opposite direction to the
stamping, the outline of the finished contour is now cut on the
sheet-metal profile 1, wherein the cutting edge 2 is generated.
[0040] The stamping and the cutting finishing are performed in
opposite directions. The directions of action are indicated in
FIGS. 2 and 3 by the arrows P and F.
[0041] The pre-cutting and the stamping are also performed in
opposite directions. This is illustrated in FIGS. 1 and 2 by the
labeling of the directions of action using the arrows V and P.
[0042] During the pre-cutting, the sheet-metal profile 1 is clamped
between a lower tool part 4 and an upper tool part 5. The
pre-cutting is performed by means of a pre-cutting punch 6. For the
pre-cutting, the pre-cutting punch 6 is, in the plane of the image
of FIG. 1, moved from top to bottom in accordance with the arrow V.
Here, a portion 8 is separated out of the sheet-metal profile 1
along a pre-cutting-edge 7.
[0043] The pre-cutting-edge 7 is situated with a spacing (a) to the
cutting edge 2 to be produced. The spacing a amounts to 0.5 times
the sheet-metal thickness d, that is to say 50% of the sheet-metal
thickness. It is basically possible for the spacing to be
dimensioned to be between 30% and 75%, between 40% and 60%, or
between 45% and 55%, of the sheet-metal thickness (d).
[0044] During the stamping, the pre-cut sheet-metal profile 1 is
fixed between the lower tool part 4 and an upper counterholder 9.
The stamping is performed using a stamping tool 10 which, in the
plane of the image, is moved from bottom to top in accordance with
the arrow P. Here, the stamping zone 11 between the pre-cutting
edge 7 and the cutting edge 2 to be produced is stamped, that is to
say the outline of the finished contour is stamped to a depth of
0.3 times the sheet-metal thickness d. Here, the displaced material
flows into the free space 3 substantially at right angles, or at an
angle of 90.degree. with respect to the stamping direction or
direction of action P.
[0045] As discussed above, the outline of the finished contour and
the thickness d of the sheet-metal profile 1 is reduced during the
stamping by 0.3 times the sheet-metal thickness d, that is to say
30%. In practice, depending on the sheet-metal profile 1 and the
cut contour or cutting edge 2 to be produced, a reduction of the
thickness d by 15% to 50%, or between 20% and 40%, may be
performed.
[0046] During the cutting finishing, the sheet-metal profile 1 is
clamped between the lower tool part 4 and an upper tool part 12.
The upper tool part 12 may also be the upper tool part 5 or the
upper counterholder 9 as illustrated in FIG. 1 or FIG. 2. For the
cutting process for the cutting finishing, the upper tool part 5 or
the upper counterholder 9 is then displaced into the
component-specific cutting finishing position. The cutting
finishing is performed using a cutting punch 13 which, in the plane
of the image of FIG. 3, moves from top to bottom in accordance with
the arrow F. Here, the stamped material of the stamping zone 11 is
separated off from the sheet-metal profile 1 along the cutting edge
2.
[0047] The method according to the disclosure for producing a cut
edge 2 on or in a sheet-metal profile 1 leads to high cut surface
quality. The cutting process can also be integrated into a
deformation process. It is therefore possible for the sheet-metal
profile 1 to be deformed before, during or after the cutting
process.
[0048] The foregoing description of some embodiments of the
disclosure has been presented for purposes of illustration and
description. It is not intended to be exhaustive or to limit the
disclosure to the precise form disclosed, and modifications and
variations are possible in light of the above teachings. The
specifically described embodiments explain the principles and
practical applications to enable one ordinarily skilled in the art
to utilize various embodiments and with various modifications as
are suited to the particular use contemplated. It should be
understood that various changes, substitutions and alterations can
be made hereto without departing from the spirit and scope of the
disclosure.
* * * * *