U.S. patent application number 14/030683 was filed with the patent office on 2014-05-08 for hot forming line for producing hot formed and press hardened steel sheet products.
This patent application is currently assigned to Benteler Automobiltechnik GmbH. The applicant listed for this patent is Benteler Automobiltechnik GmbH. Invention is credited to Stefan Adelbert, Elisabeth Danger, Carsten Trippe, Dieter Wulfes.
Application Number | 20140124105 14/030683 |
Document ID | / |
Family ID | 49226027 |
Filed Date | 2014-05-08 |
United States Patent
Application |
20140124105 |
Kind Code |
A1 |
Trippe; Carsten ; et
al. |
May 8, 2014 |
HOT FORMING LINE FOR PRODUCING HOT FORMED AND PRESS HARDENED STEEL
SHEET PRODUCTS
Abstract
A hot forming line for producing hot formed and press hardened
steel sheet products, in particular motor vehicle parts includes a
heating device and a forming device, wherein the heating device has
a temperature treatment station with an upper tool and a lower tool
and the temperature treatment station has a temperature source for
heating, wherein exchangeable temperature treatment plates are
arrangeable on the upper and/or the lower tool and the temperature
source is constructed as inductor, and the temperature treatment
plates can be heated by the inductor.
Inventors: |
Trippe; Carsten;
(Salzkotten, DE) ; Wulfes; Dieter; (Borchen,
DE) ; Adelbert; Stefan; (Delbruck, DE) ;
Danger; Elisabeth; (Paderborn, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Benteler Automobiltechnik GmbH |
Paderborn |
|
DE |
|
|
Assignee: |
Benteler Automobiltechnik
GmbH
Paderborn
DE
|
Family ID: |
49226027 |
Appl. No.: |
14/030683 |
Filed: |
September 18, 2013 |
Current U.S.
Class: |
148/567 ;
72/342.7 |
Current CPC
Class: |
Y02P 10/253 20151101;
C21D 9/46 20130101; C21D 1/185 20130101; C21D 8/005 20130101; C21D
1/673 20130101; B21D 22/022 20130101; C21D 11/00 20130101; C21D
1/42 20130101; C21D 1/34 20130101; C21D 2221/00 20130101; Y02P
10/25 20151101 |
Class at
Publication: |
148/567 ;
72/342.7 |
International
Class: |
B21D 22/02 20060101
B21D022/02; C21D 8/00 20060101 C21D008/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 7, 2012 |
DE |
10 2012 110 650.9 |
Claims
1. A hot forming line for producing hot formed and press hardened
steel sheet products, in particular motor vehicle parts,
comprising: a heating device, said heating device comprising a
temperature treatment station with an upper tool and a lower tool;
exchangeable temperature treatment plates arranged on the upper
tool and/or the lower tool; and an inductor for heating the
temperature treatment plates.
2. The hot forming line of claim 1, wherein the temperature
treatment plates are configured flat for temperature treatment of a
sheet metal blank.
3. The hot forming line of claim 1, wherein the temperature
treatment plates are configured three-dimensional wherein a hollow
space remains between the temperature treatment plates when the
temperature treatment station is closed.
4. The hot forming line of claim 1, further comprising two said
inductor, wherein one the two conductors is arranged in the upper
tool and the other one of the two inductors is arranged in the
bottom tool, said one of the inductors heating the upper tool, said
other conductor heating the bottom tool, wherein the temperature
treatment plates are heatable to above 1000.degree. C.
5. The hot forming line of claim 1, wherein a surface distribution
of the inductor essentially corresponds to a surface of one of the
temperature treatment plates associated with the inductor.
6. The hot forming line of claim 1, wherein the inductor is smaller
than one of the temperature treatment plates associated with the
inductor, wherein at least regions the one of the temperature
treatment plates are heated by the inductor.
7. The hot forming line of claim 1, wherein the inductor is
constructed so that different voltages can be applied at different
regions of the inductor thereby causing different regions of the
temperature treatment plates to attain different temperatures
8. The hot forming line of claim 1, wherein the temperature
treatment plate is constructed from at least two parts, said at
least two parts having different heat conducting properties and/or
different material properties.
9. The hot forming line of claim 1, wherein the temperature
treatment plates are constructed to establish different
temperatures in first and second regions of the sheet metal blank,
wherein the first regions are in direct contact with the
temperature treatment plates when the temperature treatment station
is closed, and wherein a space is formed in the second regions
between a surface of the sheet metal blank and the temperature
treatment plates.
10. The hot forming line of claim 1, wherein the temperature
treatment plates are constructed to establish different
temperatures in first and second regions of the sheet metal blank,
wherein the first regions are in direct contact with the
temperature treatment plates when the temperature treatment station
is closed, and wherein an insulating material is arranged in the
temperature treatment plates in the second regions.
11. The hot forming line of claim 1, further comprising a furnace
arranged upstream of the temperature treatment station for
pre-heating the metal parts or the sheet metal blank to a
temperature.
12. The hot forming line of claim 9, wherein at least the
temperature treatment plate on the lower tool has spacers, wherein
the sheet metal blank or the metal part placed on the temperature
treatment plate is supported by the spacer.
13. The hot forming line of claim 12, wherein the wherein the sheet
metal blank or the metal is supported in the second regions.
14. The hot forming line of claim 1, wherein the temperature
treatment plates have a coating.
15. The hot forming line of claim 14, wherein the coating is a
scale resisting coating.
17. The hot forming line of claim 1, wherein the temperature
treatment plates are coupled form fittingly on the upper tool
and/or the lower tool.
18. The hot forming line of claim 1, wherein the temperature
treatment plates are coupled on the upper and/or the lower tool via
bolts.
19. A method for producing a hot formed and press hardened motor
vehicle part with the hot forming line according to claim 1,
comprising: heating a sheet metal blank to a temperature below AC3;
transferring the sheet metal blank into the temperature treatment
station heating first regions of the sheet metal blank in the
temperature treatment station by means of condicutive heating to
above AC3; holding second regions of the sheet metal blank at a
temperature below AC3; and transferring the sheet metal blank into
a forming tool; forming and press hardening the sheet metal
blank.
20. The method of claim 19, wherein the sheet metal blank is heated
to below AC1, wherein the second region is held in the temperature
treatment station at below AC1.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent
Application, Serial No. 10 2012 110 650.9, filed Nov. 7, 2012,
pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a hot forming line
producing hot formed and press hardened steel sheet products.
[0003] The following discussion of related art is provided to
assist the reader in understanding the advantages of the invention,
and is not to be construed as an admission that this related art is
prior art to this invention.
[0004] It is known from state-of-the-art to produce motor vehicle
bodies from metallic materials. For this in particular steel
materials but also lightweight metal materials are used. In recent
years high-strength and ultra-high-strength steels were used as
steel materials, which have at least portions of high hardness or
ductile properties so that the strength and also the crash
performance of a motor vehicle body is increased while at the same
time saving weight.
[0005] Thus a tempering method is known for example from DE 10 2010
004 081 B3 for producing steel sheet blanks with at least two
structural regions of different ductility. For this, a blank is
first homogenously heated in a furnace to a temperature and then
further heated at least in sub-regions to a temperature above the
austenizing temperature (AC3). Subsequent thereto, the blank is
closed-die press formed and quench hardened
[0006] It would be desirable and advantageous to provide an
improved device with which it is possible to produce sheet metal
parts having regions of different strength properties, wherein the
device requires low energy and low acquisition costs and can be
flexibly used in a broad range of applications.
SUMMARY OF THE INVENTION
[0007] According to one aspect of the present invention, a hot
forming line for producing hot formed and press hardened steel
sheet products, in particular motor vehicle parts, includes a
heating device formed as a temperature treatment station with an
upper tool and a lower tool, exchangeable temperature treatment
plates arranged on the upper tool and/or the lower tool; and a
temperature source constructed as an inductor for heating the
temperature treatment plates
[0008] According to the invention it is thus possible to heat a
metallic part preferably a blank, by means of the temperature
treatment plates, which metallic part is inserted in the
temperature treatment station. The temperature treatment plates are
arranged on the upper tool and/or the lower tool so that heat is
transferred from the temperature treatment plate to the metallic
part to be heated via conductive heat transfer i.e., by heat
conduction. In order for the temperature treatment plates
themselves to be brought to a temperature, which is higher than the
ambient temperature, inductors are arranged in/or on the lower tool
and/or the upper tool. By means of these inductors it is possible
due to inductive heating to heat the temperature treatment plates
themselves. According to the invention the temperature treatment
plates can thus be exchanged to heat different parts on the upper
tool and/or the lower tool.
[0009] In particular, the temperature treatment plates can be
exchanged in case of wear and/or retrofitting. It is also possible
however that the temperature treatment plates are exchangeable in
such a manner that they can be adjusted to the different
requirements of heating. Thus it is for example possible to
configure the temperature treatment plates so that they contact the
metal part to be heated, in particular the blank, only in regions
thereby only heating regions of the metal blank.
[0010] According to another advantageous feature of the invention,
the temperature treatment plates themselves can be configured flat
for temperature treatment of the sheet metal blank. This enables in
particular to heat a sheet-metal blank by means of the temperature
treatment plates. As an alternative however it is also possible
that the temperature treatment plates are configured
three-dimensional, wherein between the temperature treatment plates
a hollow space remains in the in the temperature treatment station
when the temperature treatment station is closed. The sheet-metal
blank is then located in this hollow space. Within the scope of the
invention the term three-dimensionally configured means that the
temperature treatment plates have in particular a
three-dimensionally extending surface or contact surface.
[0011] According to another advantageous feature of the invention,
at least one inductor is arranged in the upper tool or the lower
tool, wherein the inductor of the upper tool heats the temperature
treatment plate of the upper tool and the inductor of the lower
tool heats the temperature treatment plate of the lower tool,
wherein the temperature treatment plates can preferably be heated
to a temperature of more than 1000.degree. C. by means of the
inductors. With this it is possible within the scope of the
invention that at least regions of an inserted metal part in
particular a sheet-metal blank which is preferably formed from a
steel material can be heated to a temperature above austenizing
temperature. However, it is also possible within the scope of the
invention to set a temperature of the temperature treatment plate
by means of the inductors in a targeted manner, which then
correspondingly heats the sheet-metal blank and/or the metallic
part. For example it is thus possible within the framework of the
invention to set the temperature in a targeted manner, which heats
the sheet-metal blank to AC1. However, it is also possible within
the scope of the invention to set the temperature of the
sheet-metal blank such that the sheet metal blank can be heated to
a desired temperature between 200.degree. to 1200.degree. C. In
particular it is possible by selecting the temperature treatment
plates and/or by arranging the inductors and/or by means of closed
loop or open loop control of the inductors to heat regions of a
sheet metal blank, which is inserted the temperature treatment
station to different temperatures.
[0012] According to another advantageous feature of the invention
the inductor can have essentially the same surface distribution as
the temperature treatment plate, which is associated with the
inductor. Within the framework of the invention, multiple induction
loops and/or induction coils are thus for example distributed on
the upper tool and/or lower tool or are integrated in the upper
tool and/or product so as to essentially cover the same region as
the associated temperature treatment plate.
[0013] According to another advantageous feature of the invention,
the inductor can be distributed across the surface so as to be
configured smaller than the associated temperature treatment plate.
In the following only a surface region, which corresponds to the
inductor is heated. The remaining surface regions of the
temperature treatment plate are initially not heated in a targeted
manner by the inductor. In this case however heat is conducted from
the heated surface region to the not heated surface region of the
temperature treatment plate, which however is negligible in the
context of the invention in particular in the case of short time
heating between one second and up to 10 minutes.
[0014] According to another advantageous feature of the invention,
different voltages can be applied to different regions of the
inductor, which is arranged on the upper tool and/or lower tool to
thereby generate different temperatures in different regions on the
temperature treatment plates. This is realized for example in that
different inductor loops are installed inside the lower tool and/or
upper tool, wherein different regions of the inductor loops can be
controlled independent of each other.
[0015] Further preferably it is possible within the framework of
the invention for heating regions to different temperatures to use
temperature treatment plates which are formed from multiple parts.
The at least two different parts of the temperature treatment plate
then differ in their respective heat conducting properties and/or
material properties. Thus, when the temperature treatment plate has
two regions of different heat conducting properties it is possible
to heat the temperature treatment plate to an essentially uniform
temperature by inductive heating, however due to the different heat
conducting properties heat is transferred in the two regions of the
temperature treatment plate differently to the sheet metal blank to
be heated, which in turn results in the sheet metal blank being
heated differently in different regions.
[0016] According to another advantageous feature of the invention
the temperature treatment plate can have regions of different
material properties. This makes it possible that while the
temperature treatment plate is under uniform influence of the
inductor, these different regions are heated differently due to the
different material properties. As a result, when the temperature
treatment plate contacts the sheet metal blank, different regions
of the sheet metal blank are then also heated to different
temperatures.
[0017] According to another advantageous feature of the invention,
regions of a first type and regions of a second type are treated
with different temperatures in the same sheet metal blank, wherein
the regions of the first type are in direct contact with the
temperature treatment plate themselves when the temperature
treatment station is closed and in the regions of the second type a
space is formed between the surface of the sheet metal blank and
the temperature treatment plate, which space is in particular
formed as an air gap. As an alternative it is also possible that in
the region of the second type an insulating material is arranged
between the surface of the sheet metal blank and the temperature
treatment plate. The air gap and/or the insulating material thus
results in decreased heat conduction from the temperature treatment
plate to the sheet metal blank so that different regions of the
sheet metal blank are heated to different temperatures.
[0018] The previously mentioned different embodiments of the
temperature treatment plates and/or the sectional heating of the
temperature treatment plates can also be combined in any desired
manner within the scope of the invention, with the associated
advantages. It is an important advantage of the invention that at
least two different regions can be treated with different
temperatures in the same blank. It is also possible to expose in
particular small local surfaces to temperature treatment with the
temperature treatment plates according to the invention. Especially
preferably, it is possible to temperate in the region of flanges or
passages, in particular at regions that border at the flanges or
the passages.
[0019] Subsequent to the heating of the sheet metal blank, the
sheet metal blank is transferred to a forming tool, where it is hot
formed and preferably subsequently press hardened.
[0020] According to another advantageous feature of the invention,
a furnace can be arranged in the hot forming line upstream of the
temperature treatment station and the metal parts or the sheet
metal blanks can be pre-heated in the furnace to a temperature. For
example it is possible to heat the part homogenously in the furnace
to AC1 temperature and then to heat regions above AC3 point by the
temperature treatment station. In particular this heating process
can be carried out with the temperature treatment station
particularly cost efficiently because the inductive heating only
requires a small energy input.
[0021] According to another advantageous feature of the invention,
the temperature treatment plate on the lower tool can have spacers,
wherein the blank or the metallic part that is placed on the
temperature treatment plate can be supported by the spacer so that
it is held at a distance to the surface of the temperature
treatment plate. In particular this arrangement is formed in the
region of the second type so that here a lower heating occurs than
in the region of the first type.
[0022] According to another advantageous feature of the invention,
the temperature treatment plates can have a coating, in particular
a scale resisting coating. This achieves that during the entire
production process an almost constant production quality is
maintained because the temperature treatment plates essentially do
not become contaminated due to the scale resisting coating and with
this the same heating of the different blanks, sheet metal blanks
and/or metallic parts can be carried out over the entire
production. Particularly preferably, the coating is also heat
resistant and/or wear resistant.
[0023] According to another advantageous feature of the invention,
the temperature treatment plate can be coupled form fittingly to
the upper tool and/or the lower tool, preferably via bolts. This
enables a coupling so that the bolts can also be unscrewed again
and/or are configured as quick closures, so that the temperature
treatment plates in case of a different dimensioning and/or wear
can be easily exchanged while requiring only short mounting
times.
[0024] According to another advantageous feature of the invention,
the temperature treatment plates can further be configured to have
a convex curvature, which is formed in the hollow space of the
temperature treatment station. Thus a central region of the
temperature treatment plate protrudes into the hollow space
opposite the regions of the temperature treatment plates, which
flatten towards the sides. This achieves that when the temperature
treatment station is closed the central region initially rests
against the blank and when further closing and/or pressing the
temperature treatment station, the border regions also successively
rest against the sheet metal blank to be heated. Within the scope
of the invention a full surface contact is thereby created between
the temperature treatment plate and the surface of the sheet metal
blank to be heated. According to the invention it is again possible
due to the inductive heating of the temperature treatment plate
itself to compensate displacements of up to a few millimeters that
are caused thereby, because the temperature treatment plate itself
is contactlessly heated via the inductive heating.
[0025] The invention also includes a method for producing a hot
formed and press hardened motor vehicle part with a hot forming
line according to at least claim 1, wherein the method is
characterized by the following method steps: [0026] heating a blank
to a temperature below AC3, [0027] transferring the blank into a
temperature treatment station, [0028] heating regions of a first
type in the temperature treatment station by means of conductive
heating to above AC3, [0029] holding region of a second type at a
temperature below AC3, [0030] transferring the sheet metal blank
into a forming tool, hot forming and press hardening.
[0031] According to another advantageous feature of the invention,
the blank may not already heated to below AC3 before the transfer
into the temperature treatment station but to below AC1
temperature. Regions of the second type are then held in the
temperature treatment station at a temperature below the AC-1
point. An important advantage of the method according to the
invention is in particular the possibility to set the temperature
on the sheet metal blank and/or the metallic part to be heated in a
targeted manner while at the same tie using a small amount of
energy due to the inductive heating of the temperature treatment
plate, wherein then again the temperature treatment plate heats the
part to be heated by means of conduction.
BRIEF DESCRIPTION OF THE DRAWING
[0032] Other features and advantages of the present invention will
be more readily apparent upon reading the following description of
currently preferred exemplified embodiments of the invention with
reference to the accompanying drawing, in which:
[0033] FIG. 1 shows a temperature treatment station according to
the invention with different temperature treatment plates, wherein
the temperature treatment plates have different regions;
[0034] FIG. 2 shows the temperature treatment station with only
partially arranged inductor and
[0035] FIG. 3 shows a top view onto a temperature treatment plate
according to the invention with placed on blank.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] Throughout all the Figures, same or corresponding elements
are generally indicated by same reference numerals. These depicted
embodiments are to be understood as illustrative of the invention
and not as limiting in any way. It should also be understood that
the drawings are not necessarily to scale and that the embodiments
are sometimes illustrated by graphic symbols, phantom lines,
diagrammatic representations and fragmentary views. In certain
instances, details which are not necessary for an understanding of
the present invention or which render other details difficult to
perceive may have been omitted.
[0037] Turning now to the drawing, and in particular to FIG. 1,
there is shown a temperature treatment station 1 according to the
invention, wherein the temperature treatment station 1 has an upper
tool 2 and a lower tool 3. The upper tool 2 and/or the lower tool 3
are movable in the movement direction B, so that between the
temperature treatment plate 4 of the upper tool 2 and a temperature
treatment plate 5 of the lower tool 3 a hollow space 6 remains. A
sheet metal blank 7 can be inserted into the hollow space 6,
wherein the sheet metal blank 7 can then be heated by the
temperature treatment plates 4, 5 by means of conductive heating to
a predetermined temperature.
[0038] In order to heat the temperature treatment plate 5 itself,
inductors 8 are provided on the lower tool 3 and on the upper tool
2 in the form of inductor loops 9. By means of the inductors 8 the
temperature treatment plates 4, 5 themselves can then be heated to
a desired temperature, wherein heat is then conducted from the
temperature treatment plates 4, 5 into the sheet metal blank 7 when
the temperature treatment plates 4, 5 contact the sheet metal blank
7. Consequently, the sheet metal blank 7 itself can be heated up to
the temperature of the temperature treatment plate 4, 5 depending
on the time for which the sheet metal blank 7 stays between the
upper tool 2 and the lower tool 3.
[0039] FIG. 1 also shows that the temperature treatment plate 4 of
the upper tool 2 and the temperature treatment plate 5 of the lower
tool 3 are constructed two-part. The first part 10 is made of a
different material than a second part 11. The first part 10 is for
example a material of the temperature treatment plate 4, 5 which
has a good heat conducting property and the second part 11 is a
material which relative to the second part 10 is less heat
conducting. Within the scope of the invention the second part 11
can also be configured as insulating material, for example a
ceramic or other insulating material can be used. This allows the
sheet metal blank 7 to be heated to different temperatures.
[0040] FIG. 2 shows an analogous embodiment, wherein as shown on
the right hand image plane no inductors 8 are provided above the
second part 11 of the temperature treatment plate 4, 5.
[0041] FIG. 3 shows a top view onto a lower tool 3 onto which a
sheet metal blank 7 is placed, whose contour is shown. It can be
recognized that the temperature treatment plate 5 does not extend
over the complete region of the lower tool 3 but has outer
dimensions so as to only partially rest against the outer geometry
of the sheet metal blank 7. This reduces the energy input for
heating the sheet metal blank 7 to a necessary minimal amount. It
can also be well recognized that an induction loop 9 is only formed
in the region of the first part 10 of the temperature treatment
plate 4, 5, whereas the second part 11 of the temperature treatment
plate 4, 5 does not have an inductor. The inductor loop 9 itself is
distributed above the first part 10 so that also here an adjustment
of the induction loop 9 to the outer dimensions of the first part
10 of the temperature treatment plate 5 is formed, which again
leads to energy savings.
[0042] While the invention has been illustrated and described in
connection with currently preferred embodiments shown and described
in detail, it is not intended to be limited to the details shown
since various modifications and structural changes may be made
without departing in any way from the spirit of the present
invention. The embodiments were chosen and described in order to
best explain the principles of the invention and practical
application to thereby enable a person skilled in the art to best
utilize the invention and various embodiments with various
modifications as are suited to the particular use contemplated.
[0043] What is claimed as new and desired to be protected by
Letters Patent is set forth in the appended claims and includes
equivalents of the elements recited therein:
* * * * *