U.S. patent application number 14/718553 was filed with the patent office on 2015-11-26 for modular hot forming tool.
This patent application is currently assigned to BENTELER AUTOMOBILTECHNIK GMBH. The applicant listed for this patent is BENTELER AUTOMOBILTECHNIK GMBH. Invention is credited to GEORG FROST, Max Niesse.
Application Number | 20150336151 14/718553 |
Document ID | / |
Family ID | 54431591 |
Filed Date | 2015-11-26 |
United States Patent
Application |
20150336151 |
Kind Code |
A1 |
FROST; GEORG ; et
al. |
November 26, 2015 |
MODULAR HOT FORMING TOOL
Abstract
A hot forming tool for the production of a press hardened sheet
steel product includes an upper tool and a lower tool. At least one
of the upper and lower tools has a base plate, a carrier tool
mounted on the base plate, and a mold segment exchangeably received
in the carrier tool and configured specific to the sheet steel
product.
Inventors: |
FROST; GEORG; (Steinheim,
DE) ; Niesse; Max; (Borchen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BENTELER AUTOMOBILTECHNIK GMBH |
Paderborn |
|
DE |
|
|
Assignee: |
BENTELER AUTOMOBILTECHNIK
GMBH
Paderborn
DE
|
Family ID: |
54431591 |
Appl. No.: |
14/718553 |
Filed: |
May 21, 2015 |
Current U.S.
Class: |
72/352 |
Current CPC
Class: |
B21D 37/02 20130101;
B21D 22/022 20130101 |
International
Class: |
B21D 22/02 20060101
B21D022/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 22, 2014 |
DE |
10 2014 107 210.3 |
Claims
1. A hot forming tool for the production of a press hardened sheet
steel product, comprising an upper tool and a lower tool, at least
one of the upper and lower tools having a base plate, a carrier
tool mounted on the base plate, and a mold segment exchangeably
received in the carrier tool and configured specific to the sheet
steel product.
2. The hot forming tool of claim 1, wherein the carrier tool is
exchangeably mounted to the base plate.
3. The hot forming tool of claim 1, wherein at least one of the
carrier tool and the mold segment is capable of being coupled with
a quick-action clamping system and/or quick-action coupling
system.
4. The hot forming tool of claim 1, wherein the mold segment is
comprised of multiple parts in the form of mold sub-segments, at
least two of said mold sub-segments being coupled to one another
via a thermal insulating layer placed there between.
5. The hot forming tool of claim 1, wherein at least one of the
carrier tool and the mold segment is coolable.
6. The hot forming tool of claim 1, wherein the mold segment is
made of light metal, in particular aluminum, or steel material, in
particular tool steel.
7. The hot forming tool of claim 1, further comprising a protective
wear-resistant plate placed upon the mold segment.
8. The hot forming tool of claim 1, wherein the mold segment is
configured to include a cooling duct and/or a cooling duct
system.
9. The hot forming tool of claim 4, wherein the mold segment is
configured for partial cooling, with the mold sub-segments in
particular being coolable at temperatures that differ from one
another.
10. The hot forming tool of claim 1, wherein the carrier tool has
cooling ducts and/or cooling duct ports for the mold segment.
11. The hot forming tool of claim 10, wherein the cooling duct
ports are capable of being coupled with the cooling ducts of the
mold segment.
12. The hot forming tool of claim 1, wherein the mold segment and
the carrier tool have straight cooling ducts in the form of
throughbores.
13. The hot forming tool of claim 1, wherein the mold segment
includes a mount and a molding tool sized to extend beyond the
mount, with the mount and the molding tool being made in particular
in one piece and of same material.
14. The hot forming tool of claim 1, wherein the mold segment is
cooled in at least one of two ways, a first way in which the mold
segment is directly cooled, a second way in which the mold segment
is cooled indirectly via the carrier tool.
15. The hot forming tool of claim 1, wherein the carrier tool has a
receiving trough for receiving the mold segment at least in part,
in particular to receive a mount of the mold segment.
16. The hot forming tool of claim 15, wherein the carrier tool has
cooling duct ports for the mold segment, said cooling duct ports
being arranged in a bottom of the receiving trough or in sidewalls
of the receiving trough.
17. A hot forming line for the production of a press hardened sheet
steel product, comprising; a furnace for heating a sheet steel
blank; a hot forming tool receiving the sheet steel blank from the
furnace for hot forming the sheet steel blank, said hot forming
tool comprising an upper tool and a lower tool, at least one of the
upper and lower tools having a base plate, a carrier tool mounted
on the base plate, and a mold segment received in the carrier tool
and configured specific to a sheet steel product being produced
from the sheet steel blank, said mold segment being exchangeable
with a different mold segment to enable production of different
sheet steel products of same product type; a cutting tool for
cutting the steel sheet blank formed in the hot forming tool; and a
transfer unit for transport of the sheet steel blank between the
furnace and the hot forming tool and between the hot forming tool
and the cutting tool.
18. A hot forming line for the production of a press hardened sheet
steel product, comprising; a furnace; a hot forming tool downstream
of the furnace for hot forming a sheet steel blank, said hot
forming tool comprising an upper tool and a lower tool, at least
one of the upper and lower tools having a base plate, a carrier
tool mounted on the base plate, and a mold segment received in the
carrier tool and configured specific to a sheet steel product being
produced from the sheet steel blank, said mold segment being
exchangeable with a different mold segment, and said carrier tool
being exchangeable with a different carrier tool to enable
production of different sheet steel products of different product
types; and a transfer unit for transport of the sheet steel blank
between the furnace and the hot forming tool.
19. A method for operating a hot forming line, comprising:
separating a hot forming tool from an external cooling circuit port
for initiating a product change between two different production
batches; removing a mold segment or a combination of mold segment
and carrier tool from a base plate of the hot forming tool;
selecting another mold segment of a plurality of mold segments or
another combination of mold segment and carrier tool of a plurality
of mold segments and carrier tools; attaching the other mold
segment or the other combination of mold segment and carrier tool
onto the base plate of the hot forming tool; and reconnecting the
hot forming tool to the external cooling circuit port.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent
Application, Serial No. 10 2014 107 210.3, filed May 22, 2014,
pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is
incorporated herein by reference in its entirety as if fully set
forth herein.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a hot forming tool for the
production of a press hardened sheet steel product, to a hot
forming line, and to a method for operating a hot forming line.
[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 generally known in the art to shape metal products of
hardenable steel alloys in their hot state and then to cool them
down rapidly enough to effect quenching and ultimately hardening.
Blanks are typically heated in a tempering station or furnace to a
temperature above the austenitic temperature. The thus heated
blanks are then transferred to a forming tool and shaped while
being hot at least in part. In this way, the blanks are malleable
to a greater extent compared to a cold state. The formed but still
hot metal product is then rapidly cooled down to convert the
austenitic regions into a martensitic and thus hard microstructure.
This process is normally carried out in the forming tool, which is
thus also referred to as a press hardening tool. The press
hardening tool has cooling ducts to dissipate heat. As the press
hardening tool is normally made of tool steel, the incorporation of
cooling ducts in the press hardening tool becomes complex.
[0005] Hot forming and press hardening tools made of tool steel are
constructed for the production of one particular sheet steel
product. Sheet steel products involve structures for general
machine construction, especially for motor vehicle construction,
e.g. for the vehicle body and/or chassis. For example, motor
vehicle pillars, door impact beams and such vehicle components like
sills, roof pillars, etc. are produced using hot forming and press
hardening technology.
[0006] It would therefore be desirable and advantageous to address
prior art shortcomings and in particular to provide an improved hot
forming tool which can easily be modified to allow a modular use
thereof.
SUMMARY OF THE INVENTION
[0007] According to one aspect, of the present invention, a hot
forming tool for the production of a press hardened sheet steel
product includes an upper tool and a lower tool, at least one of
the upper and lower tools having a base plate, a carrier tool
mounted on the base plate, and a mold segment exchangeably received
in the carrier tool and configured specific to the sheet steel
product.
[0008] In accordance with the present invention, the provision of a
basic tool is possible that has an upper tool and a lower tool
which are movable towards one another, typically by lowering the
upper tool toward the lower tool. The upper tool and/or lower tool,
in turn, have a base plate upon which at least one carrier tool is
mounted. The carrier tool may involve an attachment tool
constructed to receive a mold segment or molding tool that is
specific for a product to be produced. The carrier tool thus may
have mounting points for the mold segment and in addition
connections, such as cooling duct ports, via which the mold segment
can be coupled to carry out the press hardening process. The
carrier tool may be provided with tempering devices, e.g. in the
form of an inductor, to maintain the mold segment at moderate
temperature. As an alternative or in addition, the tempering device
may itself be integrated into the exchangeable mold segment.
[0009] According to another advantageous feature of the present
invention, the carrier tool may be exchangeably mounted to the base
plate. This allows production of a motor vehicle structure, e.g. A
pillar for the motor vehicle model Type 1. When the production line
should now be converted to produce an analogous motor vehicle
pillar of the motor vehicle Type 2, it is only required to exchange
the product-specific mold segment because dimensions of the
involved motor vehicle pillar are substantially the same. In the
event, a transmission tunnel or roof pillar should be produced for
example, however, the geometric dimensions are different. Thus, the
type of motor vehicle structure to be produced changes so that a
replacement of the carrier tool also becomes necessary. In other
words, the carrier tool is also designed for exchange on the base
plate.
[0010] According to another advantageous feature of the present
invention, either one of the carrier tool and the mold segment can
be configured for coupling with a quick-action clamping system
and/or quick-action coupling system. In this way, retrofitting can
be realized rapidly and effectively. For this purpose, actuators in
particular are provided which can snap in and/or lock, for example
electromechanically and/or pneumatically or by any other suitable
manner. There is thus no need to secure the heavy, up to several
hundreds kilogram, mold segments and/or carrier tools to a machine
bed with a multiplicity of several hundred bolts. A mechanical
locking can easily be released via the quick-action clamping system
in order to allow exchange of the carrier tool and/or the mold
segment and then to reattach them again by locking the quick-action
clamping system. The quick-action clamping system or quick-action
coupling system is hereby configured to allow attachment of
possible through passages and/or connections, e.g. for passage of
cooling liquid, in the absence of any particular retrofitting
steps.
[0011] According to another advantageous feature of the present
invention, the mold segment can be comprised of multiple parts in
the form of mold sub-segments. The mold segment may hereby be
subdivided transversely and/or longitudinally into single mold
sub-segments. Advantageously, the mold sub-segments are insulated
from one another in order to enable quenching and tempering of
selected regions of the motor vehicle structure to be produced.
Thus, the individual mold sub-segments can be maintained at
different temperatures, especially cooled to different
temperatures. This discriminative cooling may be implemented for
example by the absence of a flow of cooling fluid or coolant to
cooling duct ports of individual mold sub-segments. This, in turn,
can be realized by using plugs, when placing the mold segment in
the carrier tool. The presence of the plugs prohibits a flow of
cooling fluid through the selected mold sub-segment. The use of
respective valves, e.g. in the carrier tool, to prohibit or reduce
a flow of coolant through the selected mold sub-segment, is, of
course, also conceivable in order to decrease a cooling output in
relation to the remaining mold sub-segments.
[0012] The mold segment represents the actual molding tool. Each of
the upper tool and lower tool is configured to have a mold segment,
with the mold segments of the upper and lower tools interlocking
and bounding a mold cavity, when the hot forming tool is closed. A
blank placed in the mold cavity is shaped into the sheet steel
product. The sheet steel product contacts hereby the mold segments
of the upper and lower tools and can be quench-hardened by cooling
the mold segments.
[0013] According to another advantageous feature of the present
invention, the carrier tool and/or the mold segment can be
coolable. The mold segment may be cooled directly or the mold
segment may be cooled indirectly. "Directly" coolable means that
the mold segment itself is provided with cooling ducts and/or at
least is in direct contact with a cooling fluid. This may be
realized, for example, by providing a channel system on the
backside of the mold segment and/or on the carrier tool so that
cooling fluid conducted through the channel system comes into
contact with the mold segment.
[0014] "Indirect" cooling means within the scope of the invention
that the mold segment is devoid of any cooling duct but it is the
carrier tool that is provided with a cooling duct system so that
the mold segment is indirectly cooled, when the carrier tool cools
down. Advantageously, the placement of a highly heat-conductive
intermediary layer between carrier tool and mold segment is
advantageous. Indirect cooling may supplement the direct
cooling.
[0015] According to another advantageous feature of the present
invention, the mold segment may be made of light metal, in
particular from an aluminum alloy. Advantageously, a protective
wear-resistant plate can be placed upon the mold segment. A highly
heat-conductive intermediary layer may also be placed between the
protective wear-resistant plate and the core segment. The
protective wear-resistant plate may be exchangeably placed upon the
core segment so that a wearing off of the protective wear-resistant
plate can easily be addressed by simply replacing the worn-off
plate with another protective wear-resistant plate. Thus, a hot
forming tool according to the invention is easy to maintain and
cost-effective. As an alternative, the mold segment may also be
made of steel material, in particular tool steel.
[0016] When the hot forming tool according to the invention is
intended for the production of a different sheet steel product,
i.e. a product change is, for example, desired from the production
of a B pillar to the production of an A pillar or roof pillar, the
only requirement is a change of the mold segment. There is no need
to produce a complete core with respective cooling duct system.
This is beneficial because there is no need for expensive standby
and storage costs for different complete tool assemblies or
complete press facilities, and overall costs can be kept to a
minimum as far as production of the actual molding tool is
concerned because there is only need for replacing the mold
segment. Also, product tolerances and/or modifications of the
production process can be addressed in a rapid, simple and
cost-effective manner by simple replacement or suitable
modification of the mold segment. Handling of the mold segment,
which is smaller in size than both the base plate and the carrier
tool, is easy, and the mold segment can thus be produced cheaper
and/or is easy to modify or store.
[0017] According to another advantageous feature of the present
invention, the mold segment can be configured to include a cooling
duct and/or a cooling duct system. Advantageously, the mold segment
can have straight cooling ducts in the form of throughbores. These
cooling ducts can easily be formed in the mold segment at little
costs. To further enhance modularity of the hot forming tool, also
the carrier tool can have cooling ducts and/or cooling duct ports
for the mold segment, which may be standardized. This means within
the scope of the invention that each replaceable mold segment has
same connections for the cooling duct ports of the carrier tool so
that a simple exchange of the mold segment enables a coolant
introduced via the carrier tool to flow through the respective mold
segment and to provide targeted heat dissipation to carry out
quench-hardening. It may also be conceivable to use only some of
the cooling duct ports of the carrier tool to cool only some
regions in the mold segment.
[0018] According to another advantageous feature of the present
invention, the carrier tool can have a receiving trough for
receiving the mold segment at least in part. Currently preferred is
a rectangular configuration of the receiving trough. The receiving
trough has aligned openings between mold segment and carrier tool
for conducting a cooling fluid. Suitably, a seal is provided in a
transition zone of the openings. It is also conceivable to abut the
mold segment and the carrier tool snugly against one another so as
to attain a tightness sufficient to render any leakage of cooling
fluid negligible.
[0019] According to another advantageous feature of the present
invention, the cooling duct ports in the carrier tool can be formed
in a bottom of the receiving trough or on opposite sidewalls of the
receiving trough. In particular, when the cooling duct ports are
formed on the sidewalls, coolant can be guided through the
throughbores in the mold segment. When the cooling duct ports in
the carrier tool are formed in the bottom of the receiving trough,
coolant is introduced through the bottom into a cooling duct system
of the mold segment.
[0020] It is also conceivable within the scope of the invention, in
particular when the sheet steel product to be produced has overall
small outer dimensions, to produce two or more sheet steel products
at the same time. For this purpose, the base plate has mounted
thereon two carrier tools in side-by-side disposition so that two
mold segments are also arranged side-by-side. It is also possible
to produce different steel sheet products in one forming process or
during one press cycle. For example, pairs of vehicle pillars or
roof pillars can be produced respectively. In other words, the left
vehicle pillar and the right vehicle pillar of a motor vehicle type
can be produced simultaneously in one press cycle by the hot
forming tool.
[0021] According to another aspect of the present invention, a hot
forming line for the production of a press hardened sheet steel
product includes a heating unit, e.g. a furnace for heating a sheet
steel blank, a hot forming tool receiving the sheet steel blank
from the furnace for hot forming the sheet steel blank, the hot
forming tool including an upper tool and a lower tool, at least one
of the upper and lower tools having a base plate, a carrier tool
mounted on the base plate, and a mold segment received in the
carrier tool and configured specific to a sheet steel product being
produced from the sheet steel blank, the mold segment being
exchangeable with a different mold segment to enable production of
different sheet steel products of same product type, and an
optional cutting unit for trimming the hot formed sheet steel
blank.
[0022] Transfer units, such as industrial robots, can be provided
to transport the sheet steel product between the heating unit,
forming tool and optional cutting unit or to transport away a
produced sheet steel product.
[0023] A hot forming line according to the present invention can be
retrofitted in a simple, efficient and cost-effective manner for
the production of different products, without any need to replace
or store an entire hot forming tool. When producing a motor vehicle
pillar for small cars for example, and subsequently the hot forming
line is desired for the production of a motor vehicle pillar of a
midsize car, it is only required to exchange the mold segments. The
furnace, e.g. a continuous furnace, is able to heat either one of
the blanks, only the gripper device of the transfer units has to be
reprogrammed or slightly modified. Thus, the hot forming and press
hardening tool can be rapidly retrofitted through change of the
mold segments. The hot forming line may also be converted in a
similar rapid, efficient and cost-effective manner in the event of
a change in the product type. For example, it is possible to first
produce motor vehicle pillars and then produce structures that are
significantly greater in dimensions, e.g. a transmission tunnel.
The heating unit and the transfer unit can also be used in this
case. Retrofitting by exchanging at least the mold segment and,
optionally, also the carrier tool, renders the hot forming tool
according to the present invention also useful for the production
of a transmission tunnel. It thus becomes possible to store at a
production site tools for the production of different motor vehicle
structures in a cost-effective and space-saving manner and to
implement the switch in the production through rapid tool
change.
[0024] A hot forming tool according to the present invention can
also find application in a situation in which it may be necessary
for a change between two production batches of the same product,
which are produced either directly in succession or interrupted as
a result of a different product being produced in between, to
exchange the mold segments because of wear and/or unacceptable
product tolerances. In such a situation, it is especially easy to
separate the hot forming tool according to the invention from a
cooling circuit connection and to remove the mold segments from the
carrier tools or to remove the carrier tools together with the mold
segments from the hot forming tool and to replace them with new
mold segments or new mold segments on the carrier tools. The
previous carrier tools in particular may hereby be used again
because it is the molding tool of the mold segment that is
primarily responsible for the geometric precision and/or subject to
wear. Thus, retrofitting times and times for maintaining a hot
forming line, equipped with a hot forming tool according to the
invention, is significantly reduced, thereby decreasing production
costs.
BRIEF DESCRIPTION OF THE DRAWING
[0025] 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:
[0026] FIG. 1 is a perspective view of a lower tool of a hot
forming tool according to the present invention;
[0027] FIG. 2 is a plan view of the lower tool;
[0028] FIG. 3 is a sectional view of the lower tool, taken along
the line III-III of FIG. 2; and
[0029] FIG. 4 is a sectional view of another embodiment of a hot
forming tool according to the present invention.
[0030] FIG. 5 is a schematic representation of a hot forming line
with a furnace, a hot forming tool according to the present
invention and a cutting tool.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] Throughout all the figures, same or corresponding elements
may generally be 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 figures 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.
[0032] Turning now to the drawing, and in particular to FIG. 1,
there is shown a perspective view of a lower tool of a hot forming
tool according to the present invention, generally designated by
reference numeral 2. The hot forming tool 2 includes an upper tool,
not shown here, and a lower tool 1. The lower tool 1 includes a
base plate 3 which has mounted thereon two carrier tools 4 in
side-by-side arrangement. Placed or at least received in part in
the carrier tool 4 on the left-hand side of the drawing plane is a
mold segment, generally designated by reference numeral 5. The
carrier tool 4 on the right-hand side is shown without mold
segment, and it is readily apparent that the carrier tool 4 has a
receiving trough 6 of rectangular configuration. The mold segment
5, in turn, includes a bottom plate in the form of a mount 5a and a
molding tool 5b which projects beyond the mount 5a. Although not
shown in FIG. 1, the upper tool has a molding tool that complements
the molding tool 5b and may also be part of an exchangeable mold
segment. The receiving trough 6 has a bottom 7 which is formed with
cooling duct ports 8 to conduct a coolant into the mold segment 5.
Coolant is hereby introduced from the side via cooling duct ports
10 in a sidewall 9 of the receiving trough 6. The cooling duct
ports 10 receive coolant from a not shown cooling facility, heat
exchanger, or collector tank for guidance into the hot forming tool
2.
[0033] The mold segment 5 may be provided with not shown fasteners
for detachable connection of the mold segment 5 to the carrier tool
4. Currently preferred is however a connection of the mold segment
5 to the carrier tool 4 by a not shown quick-action clamping system
and/or quick-action coupling system.
[0034] FIG. 2 shows a plan view of the lower tool 1 of the hot
forming tool 2. As is readily apparent, the mold segment 5 depicted
on the left-hand of the drawing plane is used to produce a sheet
steel product in the form of a B pillar. FIG. 2 is merely a
simplified schematic illustration for ease of understanding of the
invention. It is to be understood that in practice, both carrier
tools 4 include a mold segment 5. The mold segment 5 is shown here,
by way of example, as being subdivided into mold sub-segments 5.1,
5.2, 5.3, 5.4, 5.5 in a longitudinal direction indicated by arrow
18. As a result, the mold sub-segments 5.1, 5.2, 5.3, 5.4, 5.5 can
be maintained at different temperatures. Optionally, an insulating
layer may be arranged between two neighboring mold sub-segments
5.1, 5.2, 5.3, 5.4, 5.5.
[0035] FIG. 3 shows a sectional view of the lower tool 1, taken
along the line of FIG. 2. As is readily apparent, the lateral
cooling duct ports 10 of the carrier tool 4 feed into cooling ducts
11, respectively, which extend through the carrier tool 4 to the
cooling duct ports 8 at the bottom 7 of the carrier tool 4. The
cooling ducts 10 of the carrier tool 4 feed into cooling ducts or a
cooling duct system 12 of the mold segment 5, in particular in the
mount 5a. The cooling ducts 11 are realized by straight bores and
thus easy and cost-effectively to make. The cooling duct system 12
of the mold segment 5 may be sealed off by a plug, as shown for
example in the right-hand region with respect to the drawing plane.
As an alternative, it may be possible to provide solely in the mold
segment throughbores which extend from left to right with respect
to the drawing plane, with respective cooling ducts 11 extending in
the mold segment 5 from one sidewall 9 to the opposite sidewall 9
in the receiving trough 6. Such an embodiment is shown by way of
example in FIG. 4. Parts corresponding with those in FIGS. 1-3 are
denoted by identical reference numerals and not explained again. In
this embodiment, the mold segment 5 has a core segment 13 and a
protective wear-resistant plate 14 which is placed upon the core
segment 13. Throughbores 15 extend through the core segment 13 for
direct cooling of the mold segment 5 and are fluidly connected with
not shown cooling duct ports 10 of the carrier tool 4 that lead
from one sidewall 9 to the opposite sidewall 9.
[0036] It is also conceivable within the scope of the present
invention, to provide cooling duct ports 10 in the mold segment 5
only, while the carrier tool 4 is not configured for circulation of
a coolant.
[0037] FIG. 4 further illustrates that both the upper tool 16 and
the lower tool 1 have exchangeable mold segments 5 on the carrier
tools 4. The carrier tools 4 may also be connected to the base
plates 3 by quick-action clamping systems and/or quick-action
coupling systems 19. The hot forming tool 2 is further provided
with a downholder 17 which is movable in relation to the mold
segments 5 and coupled with the lower mold segment 5. Although not
shown in detail, it is also possible as an alternative to couple
the downholder 17 directly with the carrier tool 4 and to exchange
it separately from the mold segment 5. The downholder 17 extends
hereby through the mold segment.
[0038] FIG. 5 shows a hot forming line including a furnace 20, the
hot forming tool 2 according to the invention and a cutting tool
22, and transfer units 21 for transferring a steel sheet workpiece
between the furnace 20 and the hot forming tool 2 and between the
hot forming tool 2 and the cutting tool 22.
[0039] 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 and scope of the
present invention. The embodiments were chosen and described in
order to 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.
[0040] 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:
* * * * *