U.S. patent application number 12/759566 was filed with the patent office on 2011-02-10 for method for manufacturing a structural component for a motor vehicle.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS, INC.. Invention is credited to Andreas COTT, Jurgen MAIER.
Application Number | 20110030438 12/759566 |
Document ID | / |
Family ID | 42227985 |
Filed Date | 2011-02-10 |
United States Patent
Application |
20110030438 |
Kind Code |
A1 |
MAIER; Jurgen ; et
al. |
February 10, 2011 |
METHOD FOR MANUFACTURING A STRUCTURAL COMPONENT FOR A MOTOR
VEHICLE
Abstract
A method for manufacturing a component of a vehicle structure or
vehicle seat structure is provided that includes, but is not
limited to pressing a starting material through a die in order to
produce an extruded product, separating a section from the extruded
product, and forming the separated section into the component. A
varying wall thickness of the separated section is produced during
the pressing through the die.
Inventors: |
MAIER; Jurgen;
(Weitersweiler, DE) ; COTT; Andreas;
(Waltershausen, DE) |
Correspondence
Address: |
INGRASSIA FISHER & LORENZ, P.C. (GME)
7010 E. COCHISE ROAD
SCOTTSDALE
AZ
85253
US
|
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS,
INC.
Detroit
MI
|
Family ID: |
42227985 |
Appl. No.: |
12/759566 |
Filed: |
April 13, 2010 |
Current U.S.
Class: |
72/254 ; 72/256;
72/258; 72/260 |
Current CPC
Class: |
B60N 2/68 20130101; B21C
23/06 20130101 |
Class at
Publication: |
72/254 ; 72/256;
72/258; 72/260 |
International
Class: |
B21C 23/00 20060101
B21C023/00; B21C 23/18 20060101 B21C023/18 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 14, 2009 |
DE |
102009017374.9 |
Claims
1. A method for manufacturing a component of a motor vehicle
structure, comprising the steps of: pressing a starting material
through a die in order to produce an extruded product; separating a
section from the extruded product to produce a separated section
comprising a varying wall thickness transverse to an extruding
direction (y) prior to forming an produced during the pressing the
starting material through the die; and forming the separated
section into the component.
2. The method of claim 1, wherein the component is a vehicle seat
structure for a motor vehicle seat.
3. The method according to claim 1, wherein at least one region of
the separated section that is subjected to a higher load comprises
has a greater wall thickness than at least one other region that is
subjected to a lower load.
4. The method according to claim 3, wherein the component is a
crossbeam of a frame-like backrest structure and the separated
section comprises the greater wall thickness in a region of a
headrest receptacle.
5. The method according to claim 3, wherein the component is a seat
shell and the separated section comprises the greater wall
thickness in a region of a bearing point.
6. The method according to claim 1, wherein the starting material
comprises magnesium.
7. The method according to claim 1, wherein the starting material
comprises aluminum.
8. The method according to claim 1, wherein the starting material
comprises a magnesium alloy.
9. The method according to claim 1, wherein the starting material
comprises an aluminum alloy.
10. The method according to claim 1, wherein the extruded product
is produced by impact extrusion.
11. The method according to claim 1, wherein the separated section
is formed into the component with a compressive deformation.
12. The method according to claim 11, wherein the compressive
deformation is an open-die forging.
13. The method according to claim 11, wherein the compressive
deformation is a closed-die forging.
14. The method according to claim 11, wherein the separated section
is formed into the component by hot forming.
15. The method according to claim 14, wherein the hot forming
utilizes a heating process.
16. The method according to claim 1, wherein the extruded product
has a smaller width than a finished component.
17. The method according to claim 1, wherein the extruded product
is realized in a sheet-like fashion.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to German Patent
Application No. 102009017374.9, filed Apr. 14, 2009, which is
incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention pertains to a method for manufacturing
a component of a vehicle seat structure for a motor vehicle seat or
a motor vehicle structure, as well as to a motor vehicle seat or a
motor vehicle with a structure that features several components, at
least one of which was manufactured by means of such a method.
BACKGROUND
[0003] The backrest frames of motor vehicle seats frequently
consist of metal and have the shape of an upside down U. The limbs
of the U are referred to as the longitudinal beams that are
connected by a crossbeam. The backrest frame needs to withstand the
highest loads when the vehicle is subjected to longitudinal impacts
and the torso and head of the person using the seat are thrown
against the backrest and the headrest. In this case, high loads
occur, in particular, at the connecting points between the backrest
frame and the seat frame, as well as at the connecting points
between the backrest frame and the headrest.
[0004] In order to save material and weight, the components of the
supporting structure of a vehicle seat should only have a
cross-sectional surface that is adapted to the respective maximum
load at all locations. In frequently used backrest frames that are
formed of a bent round tube, a minimum cross-sectional surface
required at locations subjected to maximum loads also needs to be
used at locations, at which only low loads occur.
[0005] In frames that are realized in the form of die cast
magnesium parts, the cross-sectional surface can be adequately
adapted to the expected load. However, certain restrictions result
from the minimum wall thickness of the structural component caused
by the casting technology. Other disadvantages are the high costs
of the casting mould, the high material price, the low ductility of
casting alloys and the high expenditures required for avoiding or
detecting casting defects such as shrink holes or pores.
[0006] In frames that are formed of folded and bent sheets,
limitations result from the fact that the sheets have the same
thickness at all locations. A great sheet thickness is only
required, for example, at the connecting points of the backrest
frame to the seat frame and the headrest brackets or in the zones
subjected to bending stress in the cross-sectional regions situated
far from the neutral axis. A smaller wall thickness would be
advantageous at all other locations because these locations are not
subjected to any significant loads.
[0007] Consequently, EP 0 745 508 B1 proposes a method for
manufacturing an approximately U-shaped frame of a backrest of a
motor vehicle seat that consists of two longitudinal beams and a
crossbeam, wherein a profiled part with a strong center zone that
is followed on both sides by a weaker region and then an adjacent
strong region is initially produced from an originally straight
band-like, flat extruded product or rolled product with constant
cross-sectional surface by means of subsequent rolling and
trimming, and wherein this profiled part is subsequently bent into
the U-shaped frame.
[0008] In this case, it is disadvantageous that the rolling process
represents an additional production step required for realizing the
different regions of the originally straight band-like, flat
extruded product or rolled product with constant cross-sectional
surface.
[0009] According to DE 43 33 500 A1 that does not concern the
manufacture of a component of a vehicle structure or vehicle seat
structure, it is necessary to subject an extruded profile to
subsequent production steps, particularly to cut open and roll said
profile. Alternatively, WO 00/29138 proposes to weld together
adjacently arranged strips of different wall thickness in order to
produce a profiled part with different wall thicknesses.
[0010] In view of the foregoing, at least one objective is to
improve a structure for a motor vehicle seat or a motor vehicle and
a method for manufacturing a component of such a structure. In
addition, other objectives, desirable features, and characteristics
will become apparent from the subsequent detailed description, and
the appended claims, taken in conjunction with the accompanying
drawings and this background.
SUMMARY
[0011] According to an embodiment of the invention, one or more
components of a structure for a motor vehicle seat or a motor
vehicle are manufactured by pressing a starting material through
one or more dies in order to produce an extruded product. The
extruded product may be manufactured, in particular, by means of
impact extrusion or extrusion.
[0012] Subsequently, a section is separated from the extruded
product, for example, by means of sawing, particularly with a band
saw, cutting, particularly with a laser, or another separating
method, wherein the separated section subsequently serves as a
semi-finished product that is formed into the component. This may
be realized, for example, by means of compressive deformation,
particularly open-die forging, closed-die forging such as, in
particular, forging, indentation forming and/or additional
extrusion. Additionally or alternatively, the separated section may
also be formed into the component by means of indirect compression,
particularly cold drawing, deep drawing, spinning, plunging, upset
bulging and/or hydroforming. The separated section may be
additionally or alternatively formed into the component by means of
tensile forming, particularly extending and/or expanding, and/or by
means of bending, particularly wiping die bending and/or die
bending.
[0013] According to an embodiment of the invention, a varying wall
thickness of the separated section is already realized when the
starting material is pressed through one or more dies such that
said section already has a varying wall thickness transverse to the
extruding direction prior to the additional forming.
[0014] This advantageously makes it possible to eliminate one or
more additional rolling or welding steps after the extrusion in the
manufacture of a structural component such that the manufacturing
costs and the manufacturing time are reduced.
[0015] On the other hand, regions that are subjected to higher
loads can be realized with greater wall thicknesses and therefore
safer and regions that are subjected to lower loads can be realized
with smaller wall thicknesses and therefore lighter and with less
material, namely without requiring an additional production step
between the extrusion and the forming into the component of the
structure.
[0016] This method makes it possible, in particular, to manufacture
a crossbeam of a frame-like backrest structure, in which the
separated section advantageously has a greater wall thickness at
least in the region of a headrest receptacle. This method likewise
makes it possible to manufacture, for example, a seat shell,
wherein the separated section advantageously has a greater wall
thickness at least in the region of a bearing point, particularly
an adjustable pivot joint for producing a connection with a
backrest. Alternatively, this inventive method also makes it
possible to manufacture other components of a motor vehicle
structure such as, for example, car body or paneling
components.
[0017] With respect to the formability during the extrusion
process, the strength and the weight, magnesium or a magnesium
alloy is particularly advantageous as a starting material. In this
case, it may be particularly advantageous to form the separated
section into the component by means of hot forming, preferably by
utilizing a heating process realized prior to or during the
extrusion through the die. In comparison with conventional methods
used so far, in which magnesium sheets with homogenous wall
thickness were initially extruded or continuously cast and these
sheets were subsequently cold-formed, the hot forming of the
separated section that is still hot from the extrusion or
continuous casting process provides superior formability, a
superior texture and/or energy savings.
[0018] According to one preferred embodiment, the extruded product
has a smaller width than the finished component during the
extrusion through the die. This makes it possible, for example, to
initially produce a narrow sheet that is subsequently widened,
particularly in regions with greater wall thickness, by means of
forming processes, preferably hot forming, particularly by
utilizing a heating process realized prior to or during the
extrusion through the die, such that wider structural components
can be manufactured with narrower dies. Other advantageous
additional developments of the present invention result from the
dependent claims and the following description of preferred
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention will hereinafter be described in
conjunction with the following drawing figures, wherein like
numerals denote like elements, and
[0020] FIG. 1A shows a step of a manufacturing method according to
the state of the art;
[0021] FIG. 1B shows a separated section according to the state of
the art manufactured in the step shown in FIG. 1A;
[0022] FIG. 1C shows a crossbeam according to the state of the art
formed from the separated section shown in FIG. 1B;
[0023] FIG. 2A shows a step of a manufacturing method according to
one embodiment of the present invention in the form of a
representation that corresponds to FIG. 1A;
[0024] FIG. 2B shows a separated section manufactured in the step
shown in FIG. 2A in the form of a representation that corresponds
to FIG. 1B;
[0025] FIG. 2C shows a crossbeam formed of the separated section
shown in FIG. 2B in the form of a representation that corresponds
to FIG. 1C;
[0026] FIG. 3A shows a frame-like backrest structure with the
crossbeam according to FIG. 2C;
[0027] FIG. 3B shows the crossbeam according to FIG. 3A; and
[0028] FIG. 4 shows a seat shell according to another embodiment of
the present invention.
DETAILED DESCRIPTION
[0029] The following detailed description is merely exemplary in
nature and is not intended to limit application and uses.
Furthermore, there is no intention to be bound by any theory
presented in the preceding background or summary or the following
detailed description.
[0030] FIG. 1A shows a step of a manufacturing method according to
the state of the art, in which a magnesium alloy is pressed through
a die 2' in the y-direction of the coordinate system illustrated in
FIG. 1A in order to produce a sheet-like extruded product 1' with
constant wall thickness in the x-direction, i.e., the transverse
direction, wherein the height is measured in the z-direction. FIG.
1B shows a cross section through the extruded product 1' in the x-z
plane, i.e., perpendicular to the extruding or pressing direction
y, wherein the constant wall thickness is illustrated in this cross
section.
[0031] Subsequently, a section is separated from the extruded
product 1' by means of a cutting process and formed into the
crossbeam 3' for a backrest of a vehicle seat structure shown in
FIG. 1C in another not-shown forming process. In FIG. 1, "y"
indicates the extruding or pressing direction of the original
extruded product 1'. Due to the constant wall thickness of the
separated section, the crossbeam formed thereof also has an
identical wall thickness at all locations and therefore is
undersized in regions that are subjected to higher loads or
oversized in regions that are subjected to lower loads.
[0032] FIG. 2A to FIG. 2C respectively show a crossbeam of a
frame-like backrest structure for a motor vehicle seat and its
manufacture according to one embodiment of the present invention,
namely in the form of representations that correspond to FIG. 1A to
FIG. 1C. According to an embodiment of the invention, an extruded
product 1 with a wall thickness that varies in the x-direction,
i.e., in the transverse direction, is already formed when the
magnesium alloy is pressed through the die 2. In the cross section
according to FIG. 2B, an edge region 1.1 with greater wall
thickness and an adjacent region 1.2 with smaller wall thickness
are shown.
[0033] If the crossbeam 3 is now produced from this extruded
product in the above-described fashion by separating a certain
section and subsequent forming, the region 1.1 with the greater
wall thickness forms a headrest receptacle 3.1 of the crossbeam 3
as indicated with broken lines in FIG. 2C if this region 1.1 that
extends in the profile direction y is bent during the forming
process. This makes it possible to manufacture an advantageous
crossbeam 3, the headrest receptacle 3.1 of which is subjected to
higher loads and therefore has a greater wall thickness while
material and weight are saved due to smaller wall thicknesses in
frontal and lateral regions that are subjected to lower loads,
namely without having to separately produce an extruded profile
with varying wall thickness between the extrusion according to FIG.
2A and the forming into the final shape of the crossbeam 3
according to FIG. 2C by means of rolling or welding together
strips.
[0034] FIG. 3A shows the frame-like backrest structure 4 with two
lateral parts and the aforementioned upper crossbeam 3 that is
illustrated in an enlarged fashion in FIG. 3B such that, in
particular, headrest guide receptacles 3.2 in the region of the
headrest receptacle 3.1 are clearly visible.
[0035] FIG. 4 shows a seat shell 5 that was manufactured
accordingly by means of extruding and subsequent forming into the
final shape, namely without an intermediate rolling process for
changing the wall thickness of the extruded product 1. Since one
edge region 1.1 was once again realized with a greater wall
thickness and rear bearing points 5.1 of the seat shell 5 are
produced with this edge region during the forming process, the
bearing points 5.1 that are subjected to higher loads also have a
greater wall thickness while material and weight are saved in a
front region that is subjected to lower loads.
[0036] While at least one exemplary embodiment has been presented
in the foregoing summary and detailed description, it should be
appreciated that a vast number of variations exist. It should also
be appreciated that the exemplary embodiment or exemplary
embodiments are only examples, and are not intended to limit the
scope, applicability, or configuration in any way. Rather, the
foregoing summary and detailed description will provide those
skilled in the art with a convenient road map for implementing an
exemplary embodiment, it being understood that various changes may
be made in the function and arrangement of elements described in an
exemplary embodiment without departing from the scope as set forth
in the appended claims and their legal equivalents.
* * * * *