U.S. patent application number 15/337794 was filed with the patent office on 2017-05-25 for hot forming line and method for producing a hot formed and press hardened motor vehicle part.
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 | 20170144207 15/337794 |
Document ID | / |
Family ID | 49226026 |
Filed Date | 2017-05-25 |
United States Patent
Application |
20170144207 |
Kind Code |
A1 |
Trippe; Carsten ; et
al. |
May 25, 2017 |
HOT FORMING LINE AND METHOD FOR PRODUCING A HOT FORMED AND PRESS
HARDENED MOTOR VEHICLE PART
Abstract
A hot forming line for producing hot formed and press hardened
steel sheet products, includes: a forming device; a heating device
having a temperature treatment station, wherein the temperature
treatment station includes an upper tool and a lower tool, and at
least one temperature treatment source; and exchangeable
temperature treatment plates for conductive temperature treatment
of a blank or part inserted into the temperature treatment station,
wherein the exchangeable temperature treatment plates are
constructed for arrangement on the upper tool and/or the lower
tool, and the temperature treatment source is constructed for
heating or cooling the temperature treatment plates. The
temperature treatment station is constructed for treating different
regions of the blank or part with different temperatures by
conductive contact of the temperature treatment plates with the
blank of part.
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: |
49226026 |
Appl. No.: |
15/337794 |
Filed: |
October 28, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14030733 |
Sep 18, 2013 |
|
|
|
15337794 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C22C 38/50 20130101;
C21D 1/673 20130101; Y02P 10/253 20151101; C22C 38/12 20130101;
C22C 38/002 20130101; Y02P 10/25 20151101; B21D 22/022 20130101;
C22C 38/06 20130101; C21D 9/46 20130101; C21D 2221/00 20130101;
C22C 38/02 20130101; C21D 1/18 20130101; C21D 1/40 20130101; C21D
1/42 20130101; C21D 8/00 20130101; C22C 38/44 20130101; C21D 9/0062
20130101; C22C 38/14 20130101; C21D 1/34 20130101; C22C 38/48
20130101; C22C 38/54 20130101; C22C 38/04 20130101; C21D 1/185
20130101; C21D 8/005 20130101 |
International
Class: |
B21D 22/02 20060101
B21D022/02; C21D 8/00 20060101 C21D008/00; C21D 1/673 20060101
C21D001/673; C21D 1/40 20060101 C21D001/40; C21D 1/18 20060101
C21D001/18; C22C 38/48 20060101 C22C038/48; C22C 38/50 20060101
C22C038/50; C22C 38/44 20060101 C22C038/44; C22C 38/06 20060101
C22C038/06; C22C 38/02 20060101 C22C038/02; C22C 38/04 20060101
C22C038/04; C22C 38/00 20060101 C22C038/00; C21D 9/46 20060101
C21D009/46; C22C 38/54 20060101 C22C038/54 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 7, 2012 |
DE |
10 2012 110 649.5 |
Claims
1. A temperature treatment station for temperature treatment of
sheet metal blanks and/or sheet metal components, said temperature
treatment station comprising: an upper tool, and a lower tool; at
least one temperature treatment source configured as an electrical
resistance heating source; and temperature treatment plates
configured for arrangement on at least one of the upper tool and
the lower tool and for conductive temperature treatment of at least
one of the sheet metal blanks and sheet metal components, said
temperature treatment plates being exchangeable and configured as
an electrical resistance themselves and heatable to above 1,000
degree Celsius.
2. The temperature treatment station of claim 1, wherein the
temperature treatment plates are configured flat for temperature
treatment of a sheet metal blank plate, and wherein a hollow space
remains between the temperature treatment plates in a closed state
of the temperature treatment station.
3. The temperature treatment station of claim 1, wherein one of the
temperature treatment plates is form fittingly coupled with the
upper tool and/or another one of the temperature treatment plates
is form fittingly coupled with the lower tool.
4. The temperature treatment station of claim 1, wherein one of the
temperature treatment plates is form fittingly coupled with the
upper tool via bolts and/or another one of the temperature
treatment plates is form fittingly coupled with the lower tool via
bolts.
5. The temperature treatment station of claim 1, wherein the
temperature treatment plates have a coating.
6. The temperature treatment station of claim 1, wherein the
coating is a scale resistant coating
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of prior filed copending
U.S. application Ser. No. 14/030,733, filed Sep. 18, 2013 which
claims the priority of German Patent Application, Serial No. 10
2012 110 649.5, 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 and
method for producing a hot formed and press hardened motor vehicle
part
[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 the state of the art to produce motor
vehicle bodies from metallic materials. For this, in particular
steel materials or lightweight metal materials are used. In recent
years high-strength and ultra high-strength steel materials were
used which have at least partially high strengths or ductile
properties so that the strength and the crash performance of a
vehicle body can be increased while at the same time saving
weight.
[0005] For example DE 10 2010 004 081 B3 discloses a heat treatment
method for producing steel sheet blanks with at least two
micro-structural regions of different ductility. For this, a blank
is first homogenously heated in a furnace to a temperature and
subsequently at least sub regions of the blank are further heated
in a heating station above the austenizing temperature (AC3). The
blank is then form pressed and quench hardened.
[0006] DE 10 2010 048 209 B3 discloses a method for producing a hot
formed and press hardened metal part, wherein the metal part is
produced as motor vehicle structural part with different strength.
For this an intermediate cooling step is provided in which a sheet
metal blank, which is first heated in its entirety to above
austenizing temperature, is intermediately cooled in a first
region. The intermediate cooling can occur directly in the
press-hardening tool. Due to the homogenous heating of the entire
plate, this requires a high energy input, wherein an intermediate
cooling in the press tool is often only sub-optimal due to energy
related aspects.
[0007] It would therefore be desirable and advantageous to provide
a method and a device with which it is possible to produce sheet
metal parts that have regions of different strength properties,
while using a low amount of energy and requiring low acquisition
costs for a device.
SUMMARY OF THE INVENTION
[0008] According to one aspect of the present invention, a hot
forming line for producing hot formed and press hardened steel
sheet products, in particular for producing 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. The temperature treatment station is characterized
according to the invention in that it has at least one temperature
treatment source for cooling or heating, and exchangeable
temperature treatment plates on the upper tool or lower tool for
conductive temperature treatment, wherein the temperature treatment
plates can be heated or cooled by the temperature treatment
source.
[0009] With the temperature treatment tool according to the
invention it is possible to correspondingly temperate the sheet
metal blanks and/or sheet metal parts which are to be treated in
the hot forming line in an energetically sensible manner. The
temperature treatment can for example include heating, in
particular a heating or warming up to above AC3 temperature or a
cooling or quenching. Within the framework of the invention it is
possible due to the exchangeable temperature treatment plates to
conductively heat sheet metal blanks i.e., flat parts and also
three-dimensionally pre-formed or end-formed parts. In the
conductive heating, the proportion of lost heat is especially low
because heat transfer essentially occurs due to heat conduction via
the temperature treatment plates to the blank to be heated or the
part to be heated. Heat that is radiated off or incidentally heated
heating spaces are completely avoided. The temperature treatment
source, in particular the heat source thus heats the temperature
treatment plate, wherein the upper and/or lower temperature
treatment plate comes to form fittingly rest against the blank or
the part by inserting a sheet metal blank or a part into the
temperature treatment device and closing the temperature treatment
device, and in this way conductively heat the blank or the part.
Within the framework of the invention a one-sided contact is also
possible.
[0010] A further important advantage of the present invention is
that the high acquisition costs of the tool with corresponding
temperature treatment devices and corresponding closing mechanics
are only incurred once and the temperature treatment device can
then be used flexibly in a broad range of applications by simple
exchange of the temperature treatment plates. Thus, only the
temperature treatment plates have to be renewed or exchanged but
not the entire temperature treatment device. As a result,
cumbersome retrofitting work is not required, and the production
costs of the parts are kept low.
[0011] The temperature treatment plates may extend over the entire
surface of the upper tool and/or the lower tool so that in the case
of a blank a hollow space is formed between the temperature
treatment plates when closing the temperature treatment device,
which hollow space essentially covers the entire plate.
[0012] According to another advantageous feature of the present
invention, the temperature treatment plates can be configured flat
for temperature treatment of a sheet blank or three-dimensionally,
wherein a hollow space remains between the temperature treatment
plates when the temperature treatment station is closed. In the
case of temperature treatment plates with flat configuration it is
thus possible to conductively temperate, in particular heat a sheet
metal blank by top-side contact with the temperature treatment
plate on the upper tool and bottom-side contact with the
temperature treatment plate on the lower tool.
[0013] According to another advantageous feature of the present
invention, preformed parts may be heated by the three-dimensionally
configured temperature treatment plates, wherein the hollow space
between the temperature treatment plates of the closed temperature
treatment station essentially corresponds to the contour of the
already preformed part. In this regard it is further advantageous
that the part is held centered and with this is fixed during the
conductive temperature treatment thereby avoiding deformation.
[0014] According to another advantageous feature of the present
invention, a temperature treatment source can be arranged in the
upper and/or the lower tool. A temperature treatment source is in
particular configured as electric resistance heating source or as
burner or as inductive heat source. The temperature treatment
source is integrated in or arranged on the upper or lower tool so
that by exchanging the temperature treatment plate a heating
preferably exclusively of the temperature treatment plate itself
occurs. This reduces the energy required for heating the part to
the essential amount so that by the at least regional contact a
fast and efficient temperature treatment, in particular a heating
of the sheet metal blank and/or the part occurs. In the case of an
electric resistance heating, the temperature treatment plate is
configured in a first embodiment especially preferably so that the
temperature treatment plate is configured itself as electric
resistor, wherein by applying a voltage essentially only the
temperature treatment plate is heated but not the upper or the
lower tool. As an alternative, an electric resistance heating
source is arranged on the upper tool or lower tool so that by
coupling with the temperature treatment plate a heating of the
temperature treatment plate via the electric resistance heat source
occurs.
[0015] When a burner is used the burner is preferably operated with
fossil fuels as a fuel oil burner, wherein the burner is preferably
arranged on the upper or lower tool so that its flame is directed
to the temperature treatment plates to be coupled. Corresponding
supply air and exhaust air for the combustion are then integrated
in the upper tool or the lower tool.
[0016] According to another advantageous feature of the present
invention, the burner can be constructed as a radiant tube which
then temperates the temperature treatment plates from a back
side.
[0017] A further preferred embodiment provides for an inductive
heating, wherein corresponding induction means are integrated on or
in the top tool or bottom tool so that the temperature treatment
plate is temperated, in particular heated via the induction means,
wherein the temperature treatment plate transfers its temperature
or heat by means of heat conduction at contact with a blank or part
to be heated. As an alternative, at least sections of the
temperature treatment plate can be used for cooling, wherein then a
channel is formed between the upper tool and the temperature
treatment plate and the lower tool and the temperature treatment
plate thereby establishing a cooling medium supply so that the
cooling medium correspondingly cools the temperature treatment
plate. The conductive contact between the blank or part to be
cooled then result in cooling of the blank or part. Cooling of the
blank or part within the context of the invention relates in
particular to a targeted setting of a temperature below or to the
starting temperature attained by the blank or part from the
preceding heating, wherein for a holding of the temperature in a
second region of the blank or part only the amount of heat is
dissipated which is necessary for heat conduction within the plate
or part, while for reducing the temperature of the part the
temperature treatment plate is set to a lower temperature.
[0018] According to another advantageous feature of the present
invention, hot air may be used for the temperature treatment. In
this case corresponding channels can then be formed in the
temperature treatment plates through which hot air flows or through
which hot air is blown by a compressor or fan. Within the framework
of the invention the temperature in the temperature treatment plate
can also be set by steaming hot air over a bottom side of the
temperature treatment plates.
[0019] The temperature treatment itself occurs in the temperature
treatment station according to the invention so that first regions
of the blank or part and second regions of the blank or part are
treated with different temperatures. For this, the first regions
are in direct contact with the temperature treatment plates when
the temperature treatment station is closed and in the second
regions between the surface of the part or the blank to be heated
or between the part and the temperature treatment plate, a distance
is formed so that an air gap is created or an insolating material
is arranged in the temperature treatment plate in the second
regions. This allows temperature treatment, in particular heating,
of first regions directly and immediately by conductive contact.
For this, the temperature treatment plates preferably have
temperatures of more than 1000.degree. C., in particular between
100.degree. C. and 1500.degree. C. so that in case of conductive
contact a temperature above austenizing temperature, i.e., above
AC3 temperature can be realized in the first regions of the blank
or part to be heated.
[0020] According to another advantageous feature of the present
invention, a hardenable steel may be used, in particular a boron
manganese steel with good hot forming and tempering properties.
[0021] Particularly preferably, a heat treatable steel is used in
the method according to the invention, which can be categorized as
micro alloy heat-treatable steel. The latter has in particular the
following alloy elements in weight percent:
TABLE-US-00001 Carbon (C) 0.19 to 0.25% Silicone (Si) 0.15 to 0.30%
Manganese (Mn) 1.10 to 1.40% Phosphorous (P) 0 to 0.025% Sulfur (S)
0 to 0.015% Chromium (Cr) 0 to 0.35% Molybdenum (Mo) 0 to 0.35%
Titanium (Ti) 0.020 to 0.050% Boron (B) 0.002 to 0.005% Aluminum
(Al) 0.02 to 0.06% Remainder iron and smelting related
contaminations
[0022] As an alternative it is also possible to use a steel alloy
which has the following alloy components expressed in weight
percent:
TABLE-US-00002 Carbon (C) 0.14-0.3% Manganese (Mn) 0.8-2.5%
Silicone (Si) 1.5-2.5% Chromium (Cr) max. 0.4% Aluminum (Al) max
0.1% Nickel (Ni) max 0.3% Boron (B) 0.0008-0.005% Titanium (Ti)
0.005-0.1% Niobium (Nb) max. 0.1% Remainder iron and smelting
related contaminations.
[0023] The distance between the surface of the part and a surface
of the temperature treatment plate in the second regions results in
an insulation, i.e., a heat transfer due to heat conduction is
prevented as a due to the air gap. As a result, the second regions
are heat treated insignificantly or in the case of a preheated
blank or part the second regions are essentially held at the
preheated temperature. In order to prevent possible heat radiation
into the air gap in the second regions, in a preferred embodiment
an insulating material is arranged in the temperature treatment
plates. This can be for example be a ceramic insulating material or
another insulating material. Within the framework of the invention
it is also possible that the temperature treatment plate carries
out a combined heating and cooling process in two different regions
at the same time. A first region is heated or is at least held at
its temperature by a heat source, wherein a second region is cooled
relative to the first region. Within the framework of the invention
it is further advantageous when a heating paste is applied to at
least the first regions for improving the heat conducting effect
during the conductive temperature treatment.
[0024] According to another advantageous feature of the present
invention, a heat conducting paste can be applied between the
respective upper tool or lower tool and the temperature treatment
plate.
[0025] In order to be able to use the temperature treatment station
as universally as possible and in a broad range of applications,
the temperature treatment station is configured so that a
temperature treatment plate is coupled with the upper tool and
another temperature treatment plate with the lower tool, wherein
the temperature treatment plates are universally exchangeable for
each application. Particularly preferably, the temperature
treatment plates are form fittingly coupled to the upper tool
and/or the lower tool, and are preferably secured via bolts. This
enables adjusting the temperature treatment station to the
respective application in a particularly short mounting time, and
when changing the hot forming line in accordance with a new product
only the temperature treatment plates have to be newly produced,
but not the temperature treatment station with a costly closing
mechanics and the costly temperature treatment sources.
[0026] According to another advantageous feature of the present
invention, the hot forming line according to the invention can be
constructed so that a furnace is arranged upstream of the
temperature treatment station, wherein the blanks and/or parts
i.e., the metal parts are homogenously preheated in the furnace to
a temperature. For example the blanks and/or parts are preheated to
a temperature above AC1, but below AC3, wherein at least first
regions of the blank are further heated in the temperature
treatment station to a temperature above AC3, and wherein second
regions of the blank or part are for example held at a temperature
between AC1 and AC3.
[0027] According to another advantageous feature of the present
invention, a spacer can be arranged on the temperature treatment
plate on the lower tool, wherein a blank or a part which is placed
on the temperature treatment plate is supported by the spacer, in
particular in the second regions so that here no conductive contact
is established between the temperature treatment plate and the
surface of the part. Further, when a second region extends over the
entire border of the part, this prevents the risk that the sheet
metal blank tilts during insertion into the temperature treatment
station and thus inadvertently comes into contact with the
temperature treatment plate.
[0028] According to another advantageous feature of the present
invention, the temperature treatment plate may have a coating. The
coating is particularly a scale-resisting coating so that a soot
deposition, contamination or scaling of the surface of the
temperature treatment plate can essentially be prevented and the
operating costs of the temperature treatment station according to
the invention can be kept low. Further the coating may be
configured heat resistant so that a baking-in or adhesion of
coatings of the blank or the part, or of a heat conducting paste
are prevented. Further, the coating can be configured wear
resistant, so that the temperature treatment plate can be used over
a cycle of a product series with negligible wear.
[0029] According to another advantageous feature of the present
invention, the blank or the part can be coated for example by an
aluminum silicone coating or a zinc coating, wherein the coating
already unites with the surface of the part in the furnace or the
coating unites with the surface of the part during the temperature
treatment process in the temperature treatment station.
[0030] The present invention further relates to a method for
producing a hot formed and press hardened motor vehicle part with a
hot forming line which includes at least one of the above mentioned
features, wherein the method is characterized by the following
method steps: [0031] heating a blank to a temperature below AC3,
[0032] transferring the blank in a temperature treatment station,
[0033] heating first regions of the blank in the temperature
treatment station by means of conductive heating to above AC3,
[0034] holding second regions of the blank at a temperature below
AC3, [0035] transferring the sheet metal plate into a forming tool,
and [0036] forming and press hardening the blank.
[0037] Accordingly, a blank is first heated homogenousiy to a
temperature below AC3, preferably in a furnace. The thus preheated
blank is then transferred into the temperature treatment station
according to the invention, wherein by conductive heating in the
temperature treatment station first regions of the blank are heated
to a temperature above AC3, wherein second regions of the blank are
held at a temperature below AC3, in particular at a temperature to
which the blank or part was first heated. In the course of this,
transition regions between the first regions and the second regions
within the range of 30 mm, in particular smaller than 20 mm are
realized.
[0038] Subsequent to the temperature treatment in the temperature
treatment station, the heat treated sheet metal blank is
transferred into a forming tool, hot formed in the forming tool and
press hardened by rapid subsequent cooling. This results in a part
that has at least two regions with different strength properties
and/or ductility properties, wherein between the regions a clearly
defined, in particular small transition region of less than 30 mm,
in particular of less than 20 mm is formed. The targeted
temperature treatment with the temperature treatment station
according to the invention further allows heating the blanks or
parts energetically optimally and in a targeted manner to
temperatures of more than 900.degree. C., so that heat loss during
the temperature treatment is avoided as far as possible.
[0039] A further embodiment of the method according to the
invention provides for the following method steps: [0040] heating a
blank to a temperature greater or equal to AC3, [0041] transferring
the blank into a temperature treatment station, [0042] cooling
second regions of the blank to a temperature below AC3, [0043]
holding first regions of the blank at a temperature above AC1, in
particular above AC3, [0044] transferring the temperature treated
sheet metal blank into a forming tool, and [0045] hot forming and
press hardening the blank.
[0046] According to another advantageous feature of the present
invention, the blank can first be heated to below AC1, wherein the
region of the second type in the temperature treatment station
itself is held at a temperature below AC1. As an alternative the
part can also be first heated to below AC1 i.e., to a temperature
of 500 or 600.degree. C. so that the energy expenditure for
preheating is only minor and subsequent thereto a post heating
occurs by the conductive heating in the temperature treatment
station according to the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0047] 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:
[0048] FIG. 1 shows a hot forming line according to the
invention,
[0049] FIG. 2 shows the temperature profile of the heating with a
hot forming line according to the invention,
[0050] FIG. 3A shows a cross section through a temperature
treatment station according to the invention,
[0051] FIG. 3B shows a cross section through another embodiment of
a temperature treatment station according to the invention
[0052] FIG. 4 shows a temperature treatment station according to
the invention with spacer,
[0053] FIG. 5 shows a temperature treatment station with two placed
on plate to be temperature treated; and
[0054] FIGS. 6a and 6b show a top view and side view of a
temperature treatment plate with thickness step.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0055] 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.
[0056] Turning now to the drawing, and in particular to FIG. 1,
there is shown a hot forming line 1 according to the invention,
wherein the hot forming line 1 has a furnace 2 for homogenously
heating a blank 3. After the heating in the furnace, the blank 3 is
transferred into a temperature treatment station 4 according to the
invention for the here shown targeted post-heating. After finishing
the temperature treatment in the temperature treatment station 4,
the blank 3 is transferred into a forming tool 5, wherein it is hot
formed in the forming tool 5 and subsequently quenched and thereby
press hardened.
[0057] FIG. 2 shows different time points t1 to t5 at which the
blank 3 passes thorough the different stations of the hot forming
line and has corresponding temperatures. For this, the part or the
blank 3 starts at a temperature below AC1 at the time point t1.
Upon transfer into the temperature treatment station 4, first
regions of the blank 3 are heated starting from the temperature
treatment in the temperature treatment station 4 at the time point
t2 to a temperature above AC3, which is shown by the curve 6.
Second regions of the blank 3, which are indicated by the curve 7
essentially remain at the temperature after exiting the furnace
2.
[0058] At the time point t3 heating in the temperature treatment
station 4 is finished and the blank 3 is transferred into a forming
tool 5. Subsequent thereto the blank is formed, wherein both
regions are already slightly cooled as a result of contact with the
forming tool 5. At the time point t4' the quenching process starts
in the forming tool 5 and the first regions 6 and the second
regions 7 are cooled from above AC3 to below AC1 so that an
essentially martensitic microstructure forms in the first regions
6, and a more ductile microstructure in the second regions 7. This
can for example be a ferritic-perlitic martensitic microstructure.
The cooling process is finished at the time point t5 and the
finished formed and press hardened part is removed from the forming
tool.
[0059] FIGS. 3A and 3B show a cross sectional view through a
temperature treatment station 4 according to the invention, wherein
the temperature treatment station 4 has an upper tool 8 and a lower
tool 9 and a temperature treatment source 10, here shown in the
form of a resistance heating device, integrated in the upper tool 8
and the lower tool 9. Further, the temperature treatment device 4
has in first regions 6 a temperature treatment plate 11 at the
upper tool 8 and also a temperature treatment plate 11 at the lower
tool 9. By means of the temperature treatment plates 11 a heat
transfer Q & occurs through conduction from the temperature
treatment source 10 via the temperature treatment plate 11 to the
surface of the part and thus into the blank 3. In the second
regions 7 on the other hand, an air gap 13 is formed between the
part surface 12 and a tool surface 14 so that essentially no heat
transfer Q & or heat introduction occurs in the second regions
7.
[0060] FIG. 3B shows an embodiment analogous to the one of FIG. 3A,
wherein in the second regions 7 between the respective upper tool 8
or lower tool 9 and the surface of the blank 3 a respective
insulating plate 15 is incorporated which enables preventing a heat
introduction as a result of heat radiation compared to the
embodiment of FIG. 3A.
[0061] According to the invention, the temperature treatment plates
11 are exchangeable so that the upper tool 8 and the lower tool 9
of the temperature treatment station 4 can be used universally and
in a broad range of applications by simple exchange of the
temperature treatment plates 11, so that the acquisition costs for
tools can be kept low.
[0062] In the application of FIG. 4, a spacer 16 is additionally
arranged in the second regions 7 in which an air gap 13 is formed
between part surface 12 and tool surface 14, so that on one hand
the surface of the blank 3 in the second regions 7 does not come
into contact with the tool surface 14, and on the other hand
tilting of the blank 3 is prevented when closing the upper tool 8
and lower tool 9 which would otherwise cause a high fluctuation of
production tolerances.
[0063] FIG. 5 shows a temperature treatment plate 11 in a top view
with cut-to-size metal sheets 17 placed on the temperature
treatment plate 11. The temperature treatment plate 11 is
configured so that insulating plates 15 are arranged in second
regions 7, and in first regions 6 the temperature treatment plates
are configured so that they come into conductive contact with the
first regions 6 essentially with their full surface. Only slight
overlaps occur between the border of the part and the border of the
contact between temperature treatment plate 11 and the part and the
border of the contact between the temperature treatment plate 11
and the part and the insulating plate 15 so that energy influx into
the parts themselves is as efficient as possible and strong heat
losses which for example are dissipated to the environment are
avoided.
[0064] FIG. 6a shows a temperature treatment plate 11 in a top view
onto a lower tool 9 without a blank being placed on the temperature
treatment plate 11. The temperature treatment plate 11 again has a
first region 6 and a second region 7, which can be subjected to
different temperature treatment. FIG. 6b shows a side view along
the line A-A however with placed-on blank 3. The blank 3 rests on
the temperature treatment plate 11, wherein the temperature
treatment plate 11 is fastened on a lower tool 9. The blank 3 has a
thickness step 19, which is mirror symmetrically formed on the
temperature treatment plate 11. Thus, a bottom side 20 of the blank
3 comes into form fitting contact on a surface 21 of the
temperature treatment plate 11. This enables homogeneously heating
a blank 3 having two different wall thicknesses W1, W2, in the
region of the thickness step 19, wherein the wall thickness W1 is
greater than the wall thickness W2. The temperature treatment
station 4 can thus be easily adjusted to a respective blank 3 to be
heated by simple exchange of the temperature treatment plate
11.
[0065] 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.
[0066] 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:
* * * * *