U.S. patent application number 16/349658 was filed with the patent office on 2019-09-19 for method and semifinished product for producing an at least partially hardened profiled component.
This patent application is currently assigned to Linde + Wiemann SE & Co. KG. The applicant listed for this patent is Linde + Wiemann SE & Co. KG. Invention is credited to Martin BELL, Peter KOPFER, Hermann MISS, Daniela NEUL, Werner SCHMIDT, Elmar VOGT.
Application Number | 20190283100 16/349658 |
Document ID | / |
Family ID | 60388071 |
Filed Date | 2019-09-19 |
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United States Patent
Application |
20190283100 |
Kind Code |
A1 |
MISS; Hermann ; et
al. |
September 19, 2019 |
METHOD AND SEMIFINISHED PRODUCT FOR PRODUCING AN AT LEAST PARTIALLY
HARDENED PROFILED COMPONENT
Abstract
The invention relates to a method for producing an at least
partially hardened profiled component and to a corresponding
semi-finished product (1) which simplifies the development process
and reduces the investment costs in production machines. At first,
a first profiled segment (19), which has a uniform cross-sectional
shape (9, 10) along its extent (22), and a second profiled segment
(20), which has a non-uniform cross-sectional shape (9, 10) along
its extent (22), are joined together at a joining point (6) in
order to form at least part of a semi-finished product (1). At the
joining point (6), the first and the second profiled segments (19,
20) have cross-sectional shapes (9, 10) which substantially
correspond with one another. After heating (25) to a hardening
temperature, the semi-finished product (1) is formed in a forming
tool (11) by means of internal high-pressure forming (26) or
pressing to produce the profiled component (2) which, after the
forming (26) within the forming tool (11), is hardened by quenching
(27).
Inventors: |
MISS; Hermann; (Berleburg,
DE) ; NEUL; Daniela; (Biskirchen, DE) ;
KOPFER; Peter; (Dillenburg, DE) ; BELL; Martin;
(Dillenburg, DE) ; VOGT; Elmar; (Ludenscheid,
DE) ; SCHMIDT; Werner; (Alzenau, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Linde + Wiemann SE & Co. KG |
Dillenburg |
|
DE |
|
|
Assignee: |
Linde + Wiemann SE & Co.
KG
Dillenburg
DE
|
Family ID: |
60388071 |
Appl. No.: |
16/349658 |
Filed: |
November 20, 2017 |
PCT Filed: |
November 20, 2017 |
PCT NO: |
PCT/EP2017/079725 |
371 Date: |
May 14, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B21D 35/006 20130101;
B21D 26/057 20130101; B21D 22/022 20130101; B21D 22/025 20130101;
B21D 26/033 20130101 |
International
Class: |
B21D 22/02 20060101
B21D022/02; B21D 26/033 20060101 B21D026/033; B21D 26/057 20060101
B21D026/057; B21D 35/00 20060101 B21D035/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 12, 2016 |
DE |
10 2016 123 265.3 |
Claims
1. A method (34) for producing an at least partially hardened
profiled component (2), with a first profiled segment (19), which
has a uniform cross-sectional shape (9, 10) along its extension or
length (22), and a second profiled segment (20), which has a
non-uniform cross-sectional shape (9, 10) along its extension or
length (22), comprising: joining the first profiled segment (19) to
the second profiled segment (20) at a joint (6) in order to form at
least part of a semi-finished product (1), wherein the first and
the second profiled segments (19, 20) have cross-sectional shapes
(9, 10) that substantially match at the joint (6), heating the
semi-finished product (1) to a hardening temperature, shaping the
semi-finished product (1) in a forming tool (11) by hydroforming
(26) or by means of pressing so as to produce the profiled
component (2), and hardening the profiled component (2) in the
forming tool (11) by quenching (27).
2. The method (34) according to claim 1, wherein the second
profiled segment (20) has a connecting end (32) with a
cross-sectional shape (9, 10) substantially matching the
cross-sectional shape (9, 10) of the first profiled component
(19).
3. The method (34) according to claim 1, wherein the profiled
segments (19, 20) are joined together by welding their connecting
ends (31, 32, 33) at the joint (6).
4. The method (34) according to claim 1, wherein at least a third
profiled segment (21) is joined to the first profiled segment (19)
or to the second profiled segment (20), said third profiled segment
having either a uniform or a non-uniform cross-sectional shape (9,
10) along its extension or length (22).
5. The method (34) according to claim 4, wherein at least one of
the first profiled segment (19), second profiled segment (20) and
third profiled segment (21) is made of an alloy that can be
hardened when heated up (25) to a hardening temperature and
subsequently quenched (27).
6. The method (34) according to claim 1, wherein the hydroforming
(26) is carried out by a pressurized gas that serves as the forming
medium, at a pressure between 300 bar and 600 bar, and the
quenching (27) is carried out with a separate cooling medium which
is conveyed into the forming tool (11) after the hydroforming
process (26).
7. The method (34) according to claim 1, wherein the first profiled
segment (19) is produced by roller/roll profiling, while the second
profiled segment (20) is produced by a U/O bending method.
8. A semi-finished product (1) for producing an at least partially
hardened profiled component (2), comprising: at least two profiled
segments (19, 20) whose extensions or lengths (22) are arranged one
after the other and which are joined together at a joint (6),
wherein the first profiled segment (19) has a uniform
cross-sectional shape (9, 10) along its length while the second
profiled segment (20) has a non-uniform cross-sectional shape (9,
10) along its length, and the profiled segments (19, 20) have
substantially matching cross-sectional shapes (9, 10) at the joint
(6), and wherein the semi-finished product (1) of the joined
together profiled segments (19, 20) is shaped by hydroforming or by
pressing, along the extensions or lengths (22) of the joined
together profiled segments (19, 20).
9. The semi-finished product (1) according to claim 8, wherein the
second profiled segment (20) has a connecting end (32) whose
cross-sectional shape (9, 10) substantially matches the
cross-sectional shape (9, 10) of the first profiled component
(19).
10. The semi-finished product (1) according to claim 8, wherein the
profiled segments (19, 20) are joined by an integral welded bond at
the joint (6).
11. The semi-finished product (1) according to claim 8, further
comprising: at least a third profiled segment (21) that has either
a uniform or else a non-uniform cross-sectional shape (9, 10) along
its extension or length (22) that is joined to one of the first
profiled segment (19) or second profiled segment (20) as part of
the semi-finished product (1).
12. The semi-finished product (1) according to claim 11, wherein
the at least one profiled segment (19, 20, 21) comprises an alloy
that can be hardened by being heated up (25) to a hardening
temperature and subsequently quenched (27).
13. A semi-finished product (1) according to claim 8, wherein the
extension or length (22) of the semi-finished product (1), at least
in certain sections, follows at least a straight line (29) and/or a
two-dimensional and/or three-dimensional curve (30).
14. The method according to claim 5, wherein the alloy comprises
steel or a boron alloyed steel.
15. The method according to claim 3, wherein the first profiled
segment and second profiled segment are joined together by laser
welding or orbital laser welding.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a national stage application (under 35
USC .sctn. 371) of PCT/EP2017/079725, filed Nov. 20, 2017, which
claims benefit of German application No. 10 2016 123 265.3, filed
Dec. 1, 2016, the contents of each of which are incorporated by
reference herein.
BACKGROUND OF THE INVENTION
Technical Field and State of the Art
[0002] The invention relates to a method for producing an at least
partially hardened profiled component, in which method a
semi-finished product, after being heated up to a hardening
temperature, is shaped in a forming tool by means of hydroforming
or by means of pressing so as to produce the profiled component
which, after being shaped in the forming tool, is hardened by means
of quenching.
[0003] In particular, the invention relates to structural profiled
components for motor vehicles such as, for example, A-pillars,
B-pillars or other frame components that can be used for the
production of monocoque car bodies. The profiled component can
especially be an A-pillar for a convertible car.
[0004] On the one hand, such profiled components are subject to
extremely high requirements in terms of their strength, for
instance, in order to enhance the crash safety of motor vehicles.
On the other hand, in modern automotive construction, these
requirements run counter to the desire for a great deal of design
flexibility as well as for lightweight construction.
[0005] The above-mentioned profiled components, which are
especially used in automotive construction, are also subject to
various requirements in terms of their mechanical strength. Such
components should be configured so as to be, for example,
mechanically stiffer in a first section, and more easily deformable
in another section. For instance, an A-pillar or a B-pillar, as
part of the crumple zone of a motor vehicle, should have a higher
strength so that it does not fail in case of an impact in the area
of the greatest load. On the other hand, by being deformed, that
same component should convert as much impact energy as possible
into deformation work. When it comes to A-pillars for convertibles,
the A-pillars should provide sufficient support for the window
frame of the windshield in order to create a survival space for the
vehicle occupants, for example, in the eventuality of a vehicle
roll-over. For this reason, such an A-pillar should exhibit a very
high mechanical strength, especially in the transition area between
the fender and the window frame. For this purpose, profiled
components are sometimes used which have a non-uniform cross
section along their extension in order to be very rigid, for
example, in certain places in a certain direction. This means that
the shape of the cross section along the extension of the component
in question makes a transition, for example, from a round basic
shape to a box-like shape and then again to a round or oval shape
so that different places of the component are provided with the
appertaining section-specific contours of the profile and the
corresponding transitions of the various profile cross
sections.
[0006] Such components can be produced, for instance, by means of
the so-called U/O bending method in which a flat metal blank is
used to first create a component with a U-shaped cross section and
it is then shaped in a second work step to create a closed
O-profile. At the same time, when it comes to such a U/O bending
method, the component can be bent in the direction of its extension
so that an extension that was originally configured as a straight
line is shaped into a two-dimensional or three-dimensional
extension curve. In this manner, for instance, a semi-finished
product can be made which, in another work step, ensures a collapse
of the cross section by means of a shaping mandrel that is inserted
into the blank. Such a method is disclosed, for example, in
European patent specification EP 2 205 370 B1. This method,
however, entails the drawback that at least one end of the
semi-finished product as well as one end of the finished component
must have a sufficiently large cross sectional shape to accommodate
the drawing mandrel. This restricts the design freedom during the
development of the final shape.
[0007] European patent specification EP 2 282 853 B1 discloses a
support core for such a U/O shaping method which is employed to
shape blanks into a structured hollow profile. The support core has
a plurality of support members connected to each other, whereby,
when the individual support members are in a position where they
have been pushed together, they form the inside contour of the
hollow profile that is to be produced so as to be at least
partially flat and they are connected to each other via coupling
elements. In such a production method, a blank is first imparted
with a U-shape. Then, the support core is inserted into the
U-shaped blank in order to then shape the blank into a hollow
profile by means of a U/O shaping process or by employing a rolling
technique.
[0008] German patent specification DE 10 2009 003 668 A1 discloses
a method and a device for the production of closed profiles,
whereby a blank is placed onto the upward-facing edges of the side
walls of a first die. A U-shaped punch is moved into the matrix of
the first die, thereby pre-shaping the blank. Owing to the movement
of the side walls of the first die relative to the matrix of the
first die, the blank acquires an at least partially U-shaped cross
section, whereby the U-shaped punch remains positioned in the
matrix of the first die. The U-shaped punch is then removed from
the U-shaped blank and from the matrix of the first die, and a
support core is inserted into the U-shaped blank. Subsequently, a
second die located opposite from the first die is put into
position. Via the side walls of the second die, which rest on the
side walls of the first die, the side walls of the first die are
moved relative to the matrix of the first die, so that the
U-shaped, bent blank is shaped into a profile with a closed cross
section.
[0009] For the production of structural components for motor
vehicles, it is also a known procedure to impart hollow profiles
with their final shape by means of hydroforming. Towards this end,
international patent document WO 98/54370 discloses a production
method to blow-mold a heated hollow blank that, after having been
expanded, is subsequently quenched in the same forming tool by
introducing a cooling medium so that the component has already
hardened when it is removed from the forming tool.
[0010] Other hydroforming methods are disclosed, for example, in
international patent application WO 2010/105341 A1 and German
patent application DE 10 2007 018 281 A1.
[0011] In the method known from international patent application WO
2010/105341 A1, sections of a tube having a round or circular
cross-section are shaped in such a way that the cross-section along
the extension of the tube is tapered. Then a bending method is
employed to impart the thus-formed tube with a shape that follows a
two-dimensional or three-dimensional curve. Subsequently, the
thus-created semi-finished product is imparted with its final shape
by means of hydroforming. In order to prevent material failure
during the hydroforming due to cold-work hardening during the
preceding forming steps, the semi-finished product has to undergo
an intermediate heat treatment so that it can be shaped by means of
the hydroforming step. Here, the semi-finished product can also
consist of two profiled segments that have been welded together and
that have already been pre-shaped so as to be conical, and after
these profiled segments have been welded, they are bent in a
bending machine so as to approximate the envisaged final shape. All
in all, however, this method proves to be quite complex since the
cold-work hardening that takes place during the production of the
semi-finished product has to be compensated for by means of a heat
treatment prior to the hydroforming process.
[0012] According to the method disclosed in German patent
application DE 10 2007 018 281 A1, it is possible for the
semi-finished product to consist of two pre-shaped tubular profiled
segments. Here, the ends of the individual profiled segments are
arranged in such a way that they can be slid into each other in
order to ensure a gas-tight closure for the subsequent hydroforming
process. This, in turn, requires for both ends of the profiled
segments to undergo a special treatment--which is also subject to
strict tolerance requirements--so as to achieve a gas-tight seal
between the two profiled segments. In the final shape of the
profiled component, both profiled segments are then joined by means
of a positive-fit, radially circumferential connection which,
however, has an influence on the final shape of the profiled
component that is to be produced.
[0013] It would also be conceivable for the method disclosed in
international patent application WO 98/543 70 A1 to be employed for
a semi-finished product produced by means of the U/O profile
forming method described above. Such a method, however, would
entail the problem that, in order to produce the semi-finished
product, which sometimes can have a length of more than one meter,
there would be a need for special presses with an extremely large
stroke of approximately more than one meter, in order to make it
possible for the above-mentioned U/O forming method to be carried
out. Moreover, such semi-finished products are developed
iteratively together with the tool for the subsequent high-pressure
forming process, whereby changes in shape due to production-related
requirements for the semi-finished product as well as for the final
product each mutually influence the other method. Consequently, the
development of such a component has proven to be particularly
complex.
[0014] Before this backdrop, the invention is based on an objective
of putting forward an improved method and an improved semi-finished
product for said method, thus allowing a simplification of the
development process as well as a reduction in the investment costs
for the requisite production machines.
SUMMARY OF THE INVENTION
[0015] The method according to the invention for producing an at
least partially hardened profiled component provides that, to start
with, a first profiled segment, which has a uniform cross-sectional
shape along its extension, and a second profiled segment, which has
a non-uniform cross-sectional shape along its extension, are joined
together at a joint in order to form at least part of a
semi-finished product, wherein the first and the second profiled
segments have cross-sectional shapes that essentially match at the
joint. After the semi-finished product has been heated up to a
hardening temperature, it is then shaped in a forming tool by means
of hydroforming or by means of pressing so as to produce the
profiled component which is subsequently hardened inside the
forming tool by means of quenching.
[0016] For instance, the first profile can be configured as a round
tube. As an alternative, the first profiled segment can be
configured as a uniform oval or box-like profile. Both profiled
segments can be produced by means of profile rolling processes that
are relatively simple and manageable, as a result of which the
production costs for the individual sections of the semi-finished
product as well as the investment costs for the requisite tools can
be significantly reduced.
[0017] The invention also assumes that only a few areas, or even
just one single area--for example, in the form of the second
profiled segment having a non-uniform cross-sectional shape along
its extension as the transition area has to be configured between
two uniform profiled segments in order to meet the necessary
requirements made of the mechanical properties. In this manner, for
example, in the case of an A-pillar of a convertible, the total
length of this second profile element can be reduced from about 1.5
m to about 0.4 m. This permits the use of considerably smaller and
thus cheaper tools.
[0018] In comparison to a likewise conceivable subsequent joining
of profiled sections that have already acquired their final shape
in order to form the profiled component, the present method entails
the advantage that any structural changes in the profiled segments
are automatically compensated for if these changes result from the
production process of the profiled segments or from the creation of
the joined connection between the profiled segments. Owing to the
heat treatment prior to the hydroforming process, such structural
changes do not occur in the finished profiled component.
[0019] Therefore, the first profiled segment can be made in a way
that is geometrically extremely simple and cost-effective, a
process in which the cost-intensive shaping steps for producing the
semi-finished product are then limited to the second profiled
segment.
[0020] The shaping in the forming tool can be carried out by means
of simple pressing. This is particularly the case for geometrically
simple profiled components in which collapsing of the profile
caused by the pressing procedure is not to be expected at all or
else only to a tolerable extent. In contrast, if collapsing of the
profile has to be prevented--that is to say, if it has to be
ensured that the wall of the semi-finished product will come to
rest against the contour of the forming tool--then hydroforming is
employed.
[0021] In accordance with an advantageous embodiment of the method
according to the invention, it is provided that, when the second
profiled segment is produced, it is made with a connecting end
whose cross-sectional shape essentially matches the cross-sectional
shape of the first profiled component. This means that the
adaptations of the cross-sectional shape needed for joining the
profiled segments can be shifted to the second profile, which is
more cost-intensive anyway, as a result of which the first profiled
segment can be produced geometrically even more simply and in a
less costly manner.
[0022] Preferably, the profiled segments can be joined by an
integral bond, for instance, by means of welding, especially
preferably by means of laser welding, particularly by means of
orbital laser welding. Such joining operations allow a very simple
production of the joined connection between the profiled segments.
In this context, the profiled segments are especially preferably
butt-welded, a measure that allows high throughput rates in the
production facility.
[0023] In a refinement of the invention, it can be provided that at
least a third profiled segment is joined to the first or to the
second profiled segment, said third segment having either a uniform
or a non-uniform cross-sectional shape along its extension. This
allows the production of semi-finished products which, as a
function of the desired final shape, are already pre-shaped and
consequently are optimally adapted to the subsequent hydroforming
process. This yields a very cost-effective semi-finished product
for the production of a profiled component, some of whose sections,
in turn, can be subject to different mechanical requirements or
which, owing to the final design, have to be produced so as to
exhibit markedly different degrees of deformation.
[0024] In a special manner, it can be provided that at least one of
the profiled segments is made of a hardenable alloy. This means
that the alloy in question can be hardened in that it is heated to
a hardening temperature and subsequently quenched, in other words,
it is quickly cooled off. In this context, the alloy preferably
consists of steel, particularly a boron-alloyed steel. During the
hardening procedure, the component is heated up to the hardening
temperature.
[0025] As far as the terminology is concerned, it should be
mentioned that the hardening temperature is a temperature above the
structural transformation temperature which, for example, in the
case of a steel material, causes a structural transformation into
an austenitic structure. Due to the subsequent rapid cooling, i.e.
the quenching, the structure is transformed into a martensitic
structure that is permanently retained when the material is in its
cooled state. In comparison to the initial structure, the
martensitic structure is harder. In the case of hardenable alloys,
the hardness of the material is particularly high after the
hardening when compared to the hardness that prevailed before.
Particularly well-suited for this are steel materials, especially
preferably boron-alloyed steel grades. In this manner, at least
partially high-strength steel components can be made. An example of
such a steel grade is 22MnB5 (see the German publication titled
SZFG material sheet 11-112, status as of May 2014, which can be
downloaded at:
http://www.salzgitter-flachstahl.de/fileadmin/mediadb/szfg/informationsma-
terial/produktinformatione
n/kaltgewalztes_feinblech/deu/22mnb5.pdf).
[0026] According to a preferred embodiment, the hydroforming is
carried out by a pressurized gas that serves as the forming medium,
especially at a pressure between 300 bar and 600 bar, whereby the
quenching is carried out with a separate cooling medium which is
conveyed into the forming tool, especially into the shaped profiled
component, after the hydroforming process.
[0027] Using pressurized gas for shaping the semi-finished product
into the finished component has the advantage that, on the one
hand, the provision of the gas in the above-mentioned pressure
range is considerably cheaper than the provision of a pressurized
liquid of the type employed in hydroforming.
[0028] According to the invention, the hydroforming or pressing of
the semi-finished product is carried out at a hardening
temperature, for instance, above 950.degree. C. This temperature
has to be present before the beginning of the quenching in order
for the desired hardening to be achieved. The high temperature
during the shaping renders the steel more resilient so that it can
be shaped by means of the pressurized gas at pressures that are
well below the pressures normally employed during hydroforming.
[0029] Moreover, a gas fundamentally exhibits a lower thermal
capacity and thermal conductivity than a liquid, so that the
temperature of the semi-finished product is only negligibly lowered
when the forming medium is introduced. In contrast, a gas or a
liquid having a relatively higher thermal conductivity or thermal
capacity is preferably employed as the cooling medium; for
instance, water or a water-oil emulsion can be used as the cooling
medium. Preferably, the method for the hydroforming and the
subsequent quenching can be based on the method disclosed in
international patent application WO 98/54370 A1.
[0030] In a preferred embodiment of the invention, it can be
provided for the first profiled segment to be produced by means of
a profile rolling method, especially by means of roller/roll
profiling, while the second profiled segment is produced by means
of a U/O bending method. An example of a U/O bending method is the
so-called T3.RTM. method of ThyssenKrupp Steel, which is described,
for example, in European patent specification EP 2 205 370 B1, in
European patent specification EP 2 282 853 B1 or in German patent
application DE 10 2009 003 668 A1.
[0031] Once the profiled segment has been shaped by means of
roller/roll profiling or by means of the U/O bending method, the
profile segment in question is joined at the seam of the sides that
are bent onto each other, preferably by means of welding, to form a
closed hollow profile that is sufficiently liquid-tight so that it
can be expanded during the subsequent hydroforming process or at
least so that, following a pressing operation, it can hold the
cooling medium needed for the quenching. The structural changes and
tensions introduced into the material by this welding operation and
the resultant structural transformation processes are largely or
completely compensated for when the material is heated up to a
hardening temperature, so that the appertaining seam on the
finished profiled components no longer, or almost no longer,
constitutes a weak spot.
[0032] A semi-finished product for producing an at least partially
hardened profiled component has at least two profiled segments
whose extensions are arranged one after the other and which are
joined together at a joint in such a way that the semi-finished
product can be shaped by means of hydroforming or by means of
pressing, whereby, along their appertaining extensions, the first
profiled segment has a uniform cross-sectional shape while the
second profiled segment has a non-uniform cross-sectional shape,
and the profiled segments have essentially matching cross-sectional
shapes at the joint.
[0033] A semi-finished product configured in this manner and
preferably produced by means of the method described above can be
adapted very well to the pressing process or to the hydroforming
process, whereby, on the one hand, the strength properties of the
produced profiled component are optimized with respect to the
amount of material that has been used and shaped. In particular,
this also makes it possible to meet the recent requirements for
lightweight construction in modern motor vehicles since less
material can be used in the areas of the profiled components that
are less stressed.
[0034] In a preferred embodiment of the invention, the second
profiled segment can be provided with a connecting end whose
cross-sectional shape essentially matches the cross-sectional shape
of the first profiled component. This has the advantage that the
adaptations needed during the production in order to subsequently
join the two profiled segments are concentrated in the second
profiled segment, which is the one that is more complex to produce
anyway, as a result of which the first profiled segment can be
produced in a very cost-effective and simple manner.
[0035] Preferably, the profiled segments can be joined by an
integral bond, for instance, by means of welding, especially
preferably by means of laser welding, particularly by means of
orbital laser welding. In this context, the profiled segments can
have connecting ends that are preferably butt-welded at the joint.
Such joining operations allow a very simple creation of the joined
connection between the profiled segments. Here, the profiled
segments are especially preferably butt-welded, a measure that
allows high throughput rates in the production facility.
[0036] Preferably, it can be provided for the semi-finished product
to have at least a third profiled segment that has either a uniform
or else a non-uniform cross-sectional shape along its
extension.
[0037] In this manner, the semi-finished product can already be
pre-shaped as a function of the desired final shape so that it can
be optimally adapted to the subsequent hydroforming process.
[0038] According to a special embodiment of the invention, it can
be provided that the at least one profiled segment consists of an
alloy that can be hardened by being heated up to a hardening
temperature and subsequently quenched, whereby the alloy preferably
consists of steel, particularly a boron-alloyed steel.
[0039] In the method according to the invention and the
semi-finished product according to the invention, it can also be
provided for the extension of the profiled segments and/or of the
semi-finished product, at least in certain sections, to follow at
least a straight line and/or a two-dimensional and/or
three-dimensional curve.
[0040] As a result, the semi-finished product can already be
pre-shaped or pre-bent so as to match the final shape of the
profiled components so that the degrees of bending necessary during
the hydroforming method can be reduced to an extent that is
permissible for the material in question. In particular, it can be
provided that the second profiled segment follows a two-dimensional
and/or a three-dimensional curve, whereby the first profiled
segment or else other profiled segments attached to the second
profiled segment are shaped so as to be straight, in other words,
so as to follow in the direction of the extension of a straight
line. In this manner, complex production steps such as, for
instance, the bending of the profiled segment or the creation of a
bent shape, can be concentrated on the second profiled segment,
which is already more cost-intensive to produce anyway.
[0041] The term "extension" of the appertaining profiled segment
refers to the part that is subsequently shaped in the forming tool.
A conical expansion that might be provided at one end of the
profiled segment for attaching a feed connection piece for the
hydroforming medium or for the cooling medium is not included under
the concept of "extension".
DESCRIPTION OF THE DRAWINGS
[0042] Additional objectives, advantages, features and application
possibilities of the present invention ensue from the description
below of an embodiment making reference to the drawing. In this
context, all of the described and/or depicted features, either on
their own or in any meaningful combination, constitute the subject
matter of the present invention, also irrespective of their
compilation in the claims or the claims to which they refer
back.
[0043] In this context, the following is shown, at times
schematically:
[0044] FIG. 1 a view of the first profiled segment according to the
invention, of the second profiled segment and of a profiled segment
before being joined;
[0045] FIG. 2 a side view of a semi-finished product according to
the invention;
[0046] FIG. 3 a side view from the left onto a profiled component
according to the invention;
[0047] FIG. 4 a side view from the right onto a profiled component
according to the invention;
[0048] FIG. 5 a schematic view from below of a semi-finished
product consisting of a first profiled segment and of a second
profiled segment;
[0049] FIG. 6 a schematic view from below of a semi-finished
product with a first profiled segment and a second profiled
segment;
[0050] FIG. 7 a schematic view of a production system according to
the invention; and
[0051] FIG. 8 a schematic view of the production method according
to the invention, in individual steps.
DETAILED DESCRIPTION OF EMBODIMENTS
[0052] For the sake of clarity, identical components or those
having the same effect are provided with the same reference
numerals in the figures shown below.
[0053] FIG. 1 schematically shows the constituents with which the
semi-finished product 1 according to the invention can be produced,
said product being shown in the joined state in FIG. 2. A profiled
component 2 is shown in side views from the left in FIG. 3 and in
side views from the right in FIG. 4.
[0054] In the present example, the profiled component 2 forms an
A-pillar 8 of a convertible that has to be configured so as to be
very stable in case the convertible rolls over. Here, especially
the area between an upper tube 3 and a lower tube 4 has to be
configured so as to be very stable, and in the present case, this
area is formed by an intermediate piece 5.
[0055] On the upper right, FIG. 1 shows the upper tube 3 that forms
the first profiled segment 19 as set forth in the invention. The
profiled segment 19 has a uniform cross-sectional shape along its
extension 22. This means that, in the present case, the
cross-sectional shape 9, which is shown here as being circular by
way of an example, is the same at every place along the extension
22. In the present case, the extension 22 itself follows a straight
line 29 in the first profiled segment 19. At its ends, the first
profiled segment 19 is provided with at least one connecting end
31. Owing to the uniform cross-sectional shape 9, which can be
seen, for example, in FIG. 5, the connecting ends 31 of the first
profiled segment 19 are likewise configured so as to be the same.
Instead of two connecting ends 31, there can also be a conical
expansion (not shown here) at one end so that a connection piece
for feeding in a forming medium or a cooling medium can be attached
so as to create a seal. Such a conical expansion is located in a
part of the appertaining profiled segment that does not have to be
included in the concept of "extension".
[0056] The second profiled segment 20 has a non-uniform
cross-sectional shape 9, 10 along its extension 22, whereby in the
present case, said shape expands starting at a connecting end 31
towards a connecting end 32 of the second profiled segment 20.
Moreover, the extension 22 of the second profiled segment 20
follows an at least two-dimensional curve 30. By the same token,
the two-dimensional curve 30 can also be a three-dimensional curve
30 which, in the views of FIGS. 1 and 2, additionally extends into
the plane of the page.
[0057] The second profiled segment, as an intermediate piece 5, has
the two differently configured connecting ends 35, 36, whereby the
connecting end 35 is shaped during the production of the profiled
segment 20 in such a way that it essentially matches the first
profiled segment 19. This means that the two connecting ends 31 and
35 can be, for instance, positioned so as to abut each other and
can then be joined together by means of a simple welding
operation.
[0058] The second connecting end 36--which lies on the second
profiled segment 20 along the extension 22 opposite from the first
connecting end 35--in turn, is shaped so as essentially match
another connecting end 32 of a third profiled segment 21. The third
profiled segment 21 is shown at the bottom of FIG. 1. It forms the
lower tube 4 of the A-pillar 8 shown in FIG. 2 and it fundamentally
has the same properties as the first profiled segment 19. Diverging
from this, however, the cross-sectional shape of the third profiled
segment 21 according to the view of FIG. 6 does not have a circular
shape but rather, for example, can have an oval cross-sectional
shape. It is also possible to select a box-like shape or a shape
that is different but that is uniform over the course of the
extension 22. These cross-sectional shapes 9, 10 would also be
possible for the first profiled segment 19. Other, different
profiled segments can adjoin the first profiled segment 19 or else
the other profiled segments 20, 21 so as to form the semi-finished
product 1 according to the invention.
[0059] FIG. 2 shows the semi-finished product 1 with the joined
upper tube 3, the lower tube 4 and the intermediate piece 5 joined
between them, and they are welded at the joints 6, 7. A well-suited
welding method here is especially one in which the individual
profiled segments 19,20, 21 are positioned so as to abut each
other. Here, it is easy to use laser welding or orbital laser
welding. The addition of welding filler is likewise possible.
[0060] It can be seen in FIG. 2 that the semi-finished product 1
likewise has an extension 22, whereby the result is that it has a
non-uniform cross-sectional shape along its extension 22. Moreover,
the extension 22 of the semi-finished product 1 here follows a
curve 30 that can be configured so as to be two-dimensional or else
three-dimensional.
[0061] FIGS. 3 and 4 show the finished profiled components 2 in the
form of the A-pillars 8, whereby it can be seen here that the
joints 6, 7 shown in FIG. 2 are hardly or not at all present on the
finished profiled components 2.
[0062] FIGS. 5 and 6 show the various cross-sectional shapes 9, 10
of the profiled segments 19, 20, 21, whereby the cross-sectional
shape 9 should depict an approximately circular form and the
cross-sectional shape 10 an approximately oval form. Instead of a
circle or an oval, there can also be an irregularly shaped contour
or a box-like shape. This depends on the desired final shape of the
profiled component 2 as well as on the production parameters of the
hydroforming method with which the semi-finished product 1 is
formed into its final shape.
[0063] FIG. 7 schematically shows a production system 33 in which
the profiled component 2 according to the invention can be
produced. This production system 33 has an installation 16 for
producing the semi-finished product 16 in which there is a tube
feed mechanism 14 for producing the first profiled segment 19, that
is to say, the upper tube 3, as well as for producing and feeding
in the third profiled segment, i.e. the lower tube 4. Moreover, the
production installation 16 for the semi-finished product has a U/O
processing station where the second profiled segment 20, that is to
say, the intermediate piece 5, is produced. The upper tube 3, the
lower tube 4 as well as the intermediate piece 5 are then fed
inside the production installation 16 for the semi-finished product
to a joining station 13 where the semi-finished product 1 is
created by joining the upper tube 3, the lower tube 4 and the
intermediate piece 5. The semi-finished product 1 is then fed to a
heating device 17 where it is heated up to a hardening temperature,
for example, above 950.degree. C., in order to subsequently be fed
in its heated state to the forming tool 11 for the subsequent
shaping. The shaping takes place inside the forming tool 11. The
semi-finished product 1 is shaped into the profiled component 2
either by means of pressing or hydroforming 26. The hydroforming 26
is carried out in that a pressurized and optionally preheated gas
that serves as the forming medium is fed into the interior of the
semi-finished product 1 so that the material of the semi-finished
product 1, under the influence of the gas pressure, comes to rest
against the contour of the forming tool 11 and in this process, the
profiled component 2 acquires its final shape. The profiled
component 2 thus produced then remains in the forming tool 11 for
the time being.
[0064] The gas that serves as the forming medium is subsequently
vented from the forming tool 11 and replaced by a cooling medium
that then performs the quenching 27 of the profiled component 2 and
thus the hardening. The forming tool 11 and the heating device 17
can each be part of a physically interrelated hydroforming
installation 18.
[0065] The formed and hardened profiled component 2 in its final
shape can still be fed to an aftertreatment station 12 where, for
instance, by means of laser cutting, any protruding edges or burrs
or else conical expansions that might have been provided at the
ends for the hydroforming 26 can then be removed.
[0066] The production method 34 schematically shown in FIG. 8, is
as follows:
[0067] First of all, the profile production 23 is carried out for
the first and second and optionally additional profiled segments
19, 20 21 which are subsequently put together to create the
semi-finished product 1 by means of joining 24. Then the
semi-finished product 1 is brought to a hardening temperature, for
instance, above 950.degree. C., in order to subsequently impart the
profiled component 2 with its final shape by means of hydroforming
26. The profiled component 2 is hardened by means of quenching 27
and by the structural transformation that takes place in this
process. Subsequently, an aftertreatment 28 can be carried out in
order to remove any protruding edges and burrs.
[0068] The method 34 according to the invention or the
semi-finished product 1 according to the invention make it possible
to produce partially as well as completely hardened profiled
components. Putting together the semi-finished product 1 out of
various profiled components 19, 20, 21 allows the use of profiled
segments made of different materials having, for example, different
hardening characteristics, so that in a single work step, differing
degrees of hardening occur in the same profiled component 2 during
the quenching 27 down from the hardening temperature.
[0069] The present invention is not restricted in terms of its
configuration to the embodiments presented here. Rather, several
variants are conceivable which make use of the solution presented
here, even in the case of other types of configurations. It will be
appreciated by those skilled in the art that changes could be made
to the embodiments described above without departing from the broad
inventive concept thereof. It is understood, therefore, that this
disclosure is not limited to the particular embodiments disclosed,
but it is intended to cover modifications within the spirit and
scope of the present disclosure as defined by the appended
claims.
LIST OF REFERENCE NUMERALS
[0070] 1 semi-finished product [0071] 2 profiled component [0072] 3
upper tube [0073] 4 lower tube [0074] 5 intermediate piece [0075] 6
joint [0076] 7 joint [0077] 8 A-pillar [0078] 9 cross-sectional
shape (circular) [0079] 10 cross-sectional shape (oval) [0080] 11
forming tool [0081] 12 aftertreatment station [0082] 13 joining
station [0083] 14 pipe feed mechanism [0084] 15 U/O processing
station [0085] 16 production installation for the semi-finished
product [0086] 17 heating device [0087] 18 hydroforming
installation [0088] 19 profiled segment [0089] 20 profiled segment
[0090] 21 profiled segment [0091] 22 extension [0092] 23 profile
production [0093] 24 joining [0094] 25 heating [0095] 26
hydroforming [0096] 27 quenching [0097] 28 aftertreatment [0098] 29
straight line [0099] 30 curve [0100] 31 connecting end [0101] 32
connecting end [0102] 33 production system [0103] 34 production
method [0104] 35 connecting end [0105] 36 connecting end
* * * * *
References