Title: Hydroformed space frame and rearward ring assembly therefor
Abstract: A space frame for a motor vehicle having a pair of laterally spaced, longitudinally extending side rail structures, a pair of forward-most upright structures each being connected to a respective side rail structure, thereby forming a pair of A pillars, a pair of roof rail structures, a forward end of each roof rail structure being connected to an upper end of an associated A pillar, and a rearward ring assembly connected at upper portions thereof with the roof rail structures and at bottom portions thereof with the side rail structures. The rearward ring assembly having (a) a tubular hydroformed inverted U-shaped upper member having a cross portion and a pair of leg portions extending downwardly from opposite ends of the cross portion, (b) a pair of tubular hydroformed side members, and (c) a cross structure rigidly connected in ring-forming relation between the second ends of the side members.
Patent Number: 6,926,350 Issued on 08/09/2005 to Gabbianelli, et al.
| Inventors:
|
Gabbianelli; Gianfranco (Troy, MI);
Ashley; Richard D. (Gaylord, MI)
|
| Assignee:
|
Cosma International Inc. (Concord, CA)
|
| Appl. No.:
|
416549 |
| Filed:
|
November 9, 2001 |
| PCT Filed:
|
November 9, 2001
|
| PCT NO:
|
PCT/US01/43043
|
| 371 Date:
|
October 17, 2003
|
| 102(e) Date:
|
October 17, 2003
|
| PCT PUB.NO.:
|
WO02/38434 |
| PCT PUB. Date:
|
May 16, 2002 |
| Current U.S. Class: |
296/203.01; 296/187.11; 296/193.08 |
| Intern'l Class: |
B60J 009/00 |
| Field of Search: |
296/29,146.05,146.08,187.01,187.03,187.11,193.01,193.08,203.01,203.04
|
References Cited [Referenced By]
U.S. Patent Documents
| 5209541 | May., 1993 | Janotik.
| |
| 5848853 | Dec., 1998 | Clenet.
| |
| 6015182 | Jan., 2000 | Weissert et al.
| |
| 6053562 | Apr., 2000 | Bednarski.
| |
| 6092865 | Jul., 2000 | Jaekel et al.
| |
| 6099039 | Aug., 2000 | Hine.
| |
| 6508035 | Jan., 2003 | Seksaria et al.
| |
| 6533348 | Mar., 2003 | Jaekel et al.
| |
| 2004/0051345 | Mar., 2004 | Gabbianelli et al.
| |
| Foreign Patent Documents |
| 0 823 363 | Feb., 1998 | EP.
| |
| 0 823 363 | Dec., 1999 | EP.
| |
| 2 131 361 | Jun., 1984 | GB.
| |
Primary Examiner: Engle; Patricia L.
Attorney, Agent or Firm: Pillsbury Winthrop Shaw Pittman LLP
Parent Case Text
This application is the National Phase of International Application PCT/US01/43043
filed 9 Nov. 2001 which designated the U.S. and that International Application
was published under PCT Article 21(2) in English on May 16, 2002 as International
Publication Number WO 02/38434 A2. This application also claims priority to U.S.
Provisional Application No. 60/247,045, filed 13 Nov. 2000, which document is herein
incorporated by reference.
Claims
1. A space frame for a motor vehicle, said space frame comprising:
a pair of laterally spaced, longitudinally extending side rail structures;
a pair of forward-most upright structures each being connected to a respective
side rail structure, thereby forming a pair of A pillars;
a pair of roof rail structures, a forward end of each roof rail structure being
connected to an upper end of an associated A pillar; and
a rearward ring assembly connected at upper portions thereof with said roof rail
structures and at bottom portions thereof with said rail structures, said rearward
ring assembly comprising (a) a tubular hydroformed inverted U-shaped upper member,
said upper member having a cross portion and a pair of leg portions extending downwardly
from opposite ends of said cross portion, (b) a pair of tubular hydroformed side
members, said side members each having first and second ends, each said side member
being connected at said first end thererof with a free end of a respective leg
portion of said upper member, and (c) cross structure rigidly connected in ring-forming
relation between said second ends of the side members,
said side rail structures, said A pillars, said roof rail structures and said
rearward ring assembly generally defining a space frame interior region, said rearward
ring assembly providing a rearward opening into said interior region, and
said side members having lower portions thereof disposed closer to one another
than upper portions thereof, said side members having lower portions thereof disposed
more rearwardly in a longitudinal frame direction in relation to upper portions
thereof,
wherein said inverted hydroformed U-shaped upper member and said hydroformed
side members together form an inverted U-shaped assembly, said inverted U-shaped
assembly defining a pair of rearward-most pillars, each said rearward-most pillar
having an essentially straight upper end portion extending downwardly from an associated
juncture with said cross portion, an essentially straight lower end portion, and
an inwardly angled central portion so that said straight upper end portions define
a relatively wide upper portion of said rearward opening and said straight lower
end portions define a relatively narrow lower portion of said rearward opening,
further including a laterally extending rearward connecting structure connected
between rearward portions of said side rail structures and wherein said cross structure
of said rearward ring assembly is connected to said rearward connecting structure
such that said cross structure extends laterally between said side rail structures,
said lower end portion of each said rearward-most pillar being connected to said
rearward first connecting structure and extending generally upwardly with respect
thereof.
2. A space frame as defined in claim 1, wherein said essentially straight upper
end portions of said rearward-most pillars taper rearwardly and said essentially
straight lower end portions of said rearward-most pillars taper rearwardly from
top to bottom.
3. A space frame as define in claim 2, wherein the essentially straight lower
end portion of each said rearward-most pillar is vertical and the essentially straight
upper end portion forms an angle of approximately 10 degrees therewith as viewed
in side elevation.
4. A space frame for a motor vehicle, said space frame comprising:
a pair of laterally spaced, longitudinally extending side rail structures;
a pair of forward-most upright structures each being connected to a respective
side rail structure, thereby forming a pair of A pillars;
a pair of roof rail structures, a forward end of each roof rail structure being
connected to an upper end of an associated A pillar; and
a rearward ring assembly connected at upper portions thereof with said roof rail
structures and at bottom portions thereof with said side rail structures, said
rearward ring assembly comprising (a) a tubular hydroformed inverted U-shaped upper
member, said upper member having a cross portion and a pair of leg portions extending
downwardly from opposite ends of said cross portion, (b) a pair of tubular hydroformed
side members, said side members each having first and second ends, each said side
member being connected at said first end thereof with a free end of a respective
leg portion of said upper member, and (c) cross structure rigidly connected in
ring-forming relation between said second ends of the side members,
said side rail structures, said A pillars, said roof rail structures and rearward
ring assembly generally defining a space frame interior region, said rearward ring
assembly providing a rearward opening into said interior region, and
said side members having lower portions thereof disposed closer to one another
than upper portions thereof, said members having lower portions thereof disposed
more rearwardly in a longitudinal frame direction in relation to upper portions
thereof,
wherein said cross structure forms a hollow, tubular element extending between
said second ends of said side members.
5. A space frame as defined in claim 4, wherein said inverted hydroformed U-shaped
upper member and said hydroformed side members together form an inverted U-shaped
assembly, said inverted U-shaped assembly defining a pair of rearward-most pillars,
each said rearward-most pillar having an essentially straight upper end portion
extending downwardly from an associated juncture with said cross portion, an essentially
straight lower end portion, and an inwardly angled central portion so that said
straight upper end portions define a relatively wide upper portion of said rearward
opening and said straight lower end portions define a relatively narrow lower portion
of said rearward opening.
6. A space frame according to claim 4, wherein said cross structure comprised
an assembly of stamped members assembled into a tubular configuration.
7. A space frame for a motor vehicle, said space frame comprising:
a pair of laterally spaced, longitudinally extending side rail structures;
a pair of forward-most upright structures each being connected to a respective
side rail structure, thereby forming a pair of A pillars;
a pair of roof rail structures, a forward end of each roof rail structure being
connected to an upper end of an associated A pillar; and
a rearward ring assembly connected at upper portions thereof with said roof rail
structures and at bottom portions thereof with said side rail structures, said
rearward ring assembly comprising (a) a tubular hydroformed inverted U-shaped upper
member, said upper member having a cross portion and a pair of leg portions extending
downwardly from opposite ends of said cross portion, (b) a pair of tubular hydroformed
side members, said side members each having first and second ends, each said side
member being connected at said first end thereof with a free end of a respective
leg portion of said upper member, and (c) cross structure rigidly connected in
ring-forming relation between said second ends of the side members,
said side rail structures, said A pillars, said roof rail structures and said
rearward ring assembly generally defining a space frame interior region, said rearward
ring assembly providing a rearward opening into said interior region, and
said side members having lower portions thereof disposed closer to one another
than upper portions thereof, said side members having lower portions thereof disposed
more rearwardly in a longitudinal frame direction in relation to upper portions
thereof,
further including a front structural assembly, said front structural assembly
comprising a pair of front upper side rail structures, a front cross structural
assembly and a pair of side support structures, said front cross structural assembly
being connected laterally between forward end portions of said side rail structures,
each said front upper side rail structure being connected between said front cross
structural assembly and an intermediate portion of a respective A pillar so that
said front upper side rail structures are laterally space from one another and
generally vertically space above forward portions of said side rail structures,
each side support structure being connected at one end to an intermediate portion
of a respective A pillar and extending forwardly and downwardly therefrom and being
connected at another end opposite said one end to an associated side rail structure.
8. A space frame as defined in claim 7, wherein said pair of front upper side
rail structures are provided by a pair of tubular hydroformed front upper side
rail members and wherein said pair of side support structures are provided by a
pair of tubular hydroformed front upper side rail members.
9. A space frame as defined in claim 8, wherein said roof rail structures are
tubular hydroformed members.
10. A space frame for a motor vehicle, comprising:
a pair of side rail structures, said side rail structures each having an upwardly
arched portion defining a pair of wheel wells;
first and second connecting structures connected laterally between said side
rail structures rearwardly and forwardly, respectively, of said wheel wells; and
a cradle assembly comprising a pair of elongated cradle support structures and
a pair of U-shaped cradle structures, each U-shaped cradle structure having a pair
of leg portions extending from a cross portion, said cradle support structures
being laterally spaced and each being connected between said first and second connecting
structures, said U-shaped cradle structures being longitudinally spaced and each
leg portion of said pair of leg portions of each said U-shaped cradle structure
being connected to a respective one of said pair of cradle support structures.
11. A space frame as defined in claim 10, wherein each said cradle support structure
is provided by a tubular hydroformed cradle support member, each said cradle support
member being defined by an outwardly deformed metallic wall fixed into a predetermined
surface configuration, and wherein each said U-shaped cradle structure is provided
by a tubular hydroformed U-shaped cradle member, each said U-shaped cradle member
being defined by an outwardly deformed metallic wall fixed into a predetermined
surface configuration.
12. A space frame as defined in claim 11, wherein said pair of corresponding
wheel wells define a pair of rear wheel wells.
13. A method of forming a space frame for a motor vehicle, comprising:
providing components for a space frame including a pair of side rail structures,
each side rail structure including a wheel well-forming portion, a pair of connecting
structures, and a cradle assembly, said cradle assembly including a pair of elongated
cradle support members and a pair of U-shaped cradle members, each U-shaped cradle
member having a pair of leg portions extending from a cross portion, the cradle
support members and the U-shaped cradle members each being formed in a hydroforming
procedure that includes providing a tubular blank having a metallic wall, placing
the blank in a die assembly having die surfaces defining a die cavity and providing
pressurized fluid in an interior of the blank to expand said wall into conformity
with said die surfaces, and
assembling said components such that the first and second connecting structures
are connected laterally between said side rail structures rearwardly and forwardly,
respectively, of said wheel well-forming portions, said cradle support members
are laterally spaced and are each connected between the first and second connecting
structures, and said U-shaped cradle structures are longitudinally spaced and each
leg portion of said pair of leg portions of each U-shaped cradle member is connected
to a respective one of said pair of cradle support members.
14. A method of forming a space frame for a motor vehicle, comprising:
providing components for a space frame including a pair of side rail structures,
a pair of roof rail structures, pair of forward-most and rearward-most upright
structure, and a front structural assembly, said front structural assembly including
a pair of forward upper rail members, a front cross structural assembly and a pair
of side support members, each said member being formed in a hydroforming procedure,
each procedure including providing a tubular blank having a metallic wall, placing
the blank into a die assembly having die surfaces defining a die cavity, and providing
pressurized fluid into an interior of the blank to expand the wall into conformity
with the die surfaces; and
assembling said components so that forward-most upright structure is connected
to a respective side rail structure so as to define an A pillar thereon, each rearward-most
upright structure is connected to a respective side rail structure so as to define
a D pillar thereon, each roof rail structure is connected between an upper end
of a respective A pillar and an upper end of an associated D pillar, said front
cross structural assembly is connected laterally between forward end portions of
said side rail structures, each front upper side rail member is connected between
said front cross structural assembly and an intermediate portion of a respective
a pillar so that said front upper side rail members are laterally spaced from one
another and are each generally vertically spaced above the forward portion of an
associated side rail structure, and each side support member is connected at one
end to an intermediate portion of a respective A pillar and extends forwardly and
downwardly therefrom and is connected at another end opposite said one end to an
associated side rail structure.
15. A method for forming a rearward ring frame assembly for a motor vehicle, comprising:
bending a tubular blank into a generally U-shaped configuration; hydroforming
said U-shaped blank to form a hydroformed inverted U-shaped frame member by applying
pressurized fluid internally to said U-shaped blank so as to expand said U-shaped
blank into conformity with die surfaces of a hydroforming die;
providing a pair of side member blanks;
hydroforming each of said side members blanks to form a pair of frame side members
by applying pressurized fluid internally thereto so as to expand said side member
blank into conformity with die surfaces of a hydroforming die;
connecting a first end of each said hydroformed frame side members to associated
leg portions of said hydroformed inverted U-shaped frame member;
providing a cross structure; and
connecting said cross structure between second ends of said hydroformed frame
side members,
wherein the providing a cross structure includes forming a cross structure as
a hollow, tubular element.
16. A space frame for a motor vehicle, said space frame comprising:
a pair of laterally spaced, longitudinally extending side rail structures;
a pair of forward-most upright structures each being connected to a respective
side rail structure, thereby forming a pair of A pillars;
a pair of roof rail structures, a forward end of each roof rail structure being
connected to an upper end of an associated A pillar; and
a rearward ring assembly connected at upper portions thereof with said roof rail
structures and at bottom portions thereof with said side rail structures, said
rearwarding ring assembly comprising (a) a tubular hydroformed inverted U-shaped
upper member, said upper member having a cross portion and a pair of leg portions
extending downwardly from opposite ends of said cross portion, (b) a pair of tubular
hydroformed side members, said side members each having first and second ends,
each said side member being connected at said first end thereof with a free end
of a respective leg portion of said upper member, and (e) cross structure rigidly
connected in ring-forming relation between said second ends of the side members,
said side rail structures, said A pillars, said roof rail structures and said
rearwarding ring assembly generally defining a space frame interior region, said
rearward ring assembly providing a rearward opening into said interior region,
and
said side members having lower portions thereof disposed closer to one another
than upper portions thereof, said side members having lower portions thereof disposed
more rearwardly in a longitudinal frame direction in relation to upper portions
thereof,
wherein said rearward ring assembly is rigidly and permanently connected at upper
portions thereof with said rail structures, also
said rearward ring assembly is rigidly and permanently connected at bottom portions
thereof with said side rail structures.
Description
FIELD OF THE INVENTION
The present invention is generally related to motor vehicle frames and more particularly
to space frames that utilize tubular hydroformed members.
BACKGROUND OF THE INVENTION
Space frame architecture is increasingly being used in vehicle manufacturing
and represents a relatively new approach to vehicle construction. A space frame
is an assembly of individual frame components that are connected at joints to form
a cage-like structure on which the other vehicle components, such as the engine,
the drive train, the suspension and the hang-on vehicle body parts, are mounted.
The hang-on vehicle body parts may include the floor pan, roof, fenders, doors,
body panels, hood and trunk lid.
Individual space frame components can be of hydroformed construction.
Tubular hydroforming offers many advantages in space frame construction because
it allows vehicle manufacturers to better control frame stiffness, dimensional
accuracy, fatigue life, and crashworthiness over prior vehicle construction methods
while reducing frame mass and cost. Non-hydroformed vehicle frame construction
typically utilizes individual frame components that are formed, for example, by
roll forming or by forming several metallic structures by stamping and then welding
them together. Hydroforming is a metal-forming process in which high pressure fluid
is used to outwardly expand a tubular blank into conformity with surfaces of a
die cavity of a die assembly to form an irregularly shaped tubular part. Individual
hydroformed members can be provided with a wider range of complex longitudinal
curvatures and transverse cross sectional shapes in comparison with stamped or
roll formed parts. Each hydroformed member can have a transverse cross-sectional
configuration that varies continuously along its length, to the configuration desired.
Hydroformed parts are also advantageous because they have a higher strength
than stamped parts, partly because of their tubular (i.e., closed cross sectional)
construction and partly because the outward expansion of the wall of the blank
during hydroforming caused by the fluid pressure creates a work-hardening effect
which uniformly hardens the metallic material of the resulting individual hydroformed
member. Hydroforming also produces less waste metal material than stamping.
Sheet metal panels (forming exterior surface portions of, for example, the
fenders, the hood, the roof and the hatchback or trunk) and glass panels (such
as, for example, the front and rear windshields and the side windows) mounted on
the space frame comprise most of the exterior of the vehicle. In recent years consumers
have preferred vehicles having curved exterior surfaces and rounded corners and edges.
Although many consumers prefer vehicles having these curved and rounded
exterior surfaces for aesthetic reasons, these body types offer many functional
advantages beyond the improved aesthetics. Vehicles having curved and rounded exterior
surfaces, for example, have improved aerodynamic properties. Improved aerodynamics
provide many advantages, including improved fuel efficiency and improved vehicle
handling, particularly at high speeds. Curved and rounded vehicle exterior surfaces
(including both glass and metal surfaces) are generally convex and therefore scatter
reflected light more efficiently than flat exterior surfaces, thereby improving
driver visibility in direct sunlight. It is particularly desirable in this regard
that the exterior surface on the back of the vehicle be rounded to avoid reflecting
a large quantity of bright sunlight toward drivers in other vehicles.
For a vehicle body to have a curved exterior surface, portions of the space frame
which support the metallic and glass body panels must often have a similar curvature.
Although tubular blanks can be hydroformed so that the transverse cross-sectional
geometry and the longitudinal shape (for example, the longitudinal curvature) of
the finally-formed hydroformed member varies greatly, some space frame components
must have a very complex geometry which cannot easily be achieved by using a component
comprised of a hydroformed member formed from a single tubular blank.
There are several reasons for the practical limitations on the complexity of
the geometry of an individual hydroformed member. During hydroforming, a tubular
metallic blank is usually expanded radially outwardly along its length and is pushed
axially inwardly at each end during this outward expansion to control the wall
thickness, thereby preventing the localized wall thinning that would otherwise
occur during outward expansion. This axial pressure exerted on the ends of the
blank causes portions of the outer surface of the tubular blank to slide in an
axial direction with respect to the die cavity surface. The greater the degree
of outward expansion of the blank into conformity with the die surface and the
greater the radially directed outward pressure (caused by the internal fluid pressure),
the greater the surface-to-surface frictional force between the cavity and the
blank. A lubricant is often applied to the outer surface of the blank prior to
placement of the blank in the die cavity of the die assembly to facilitate axial
movement of the metallic wall of the blank with respect to the surface defining
the die cavity during outward expansion. If required by the geometry of the hydroformed
member, the tubular blank may be pre-bent at selected locations along its length
prior to placement into the die cavity. The more complex the geometry of the blank
due to pre-bending and the longer the length of the tubular blank, the more difficult
it is to achieve axial flow of the metallic material of the tubular blank during
outward expansion. Consequently, some complex individual tubular hydroformed space
frame member geometric configurations cannot be achieved with commercially available
hydroforming technology, and other complex tubular hydroformed space frame geometric
configurations cannot be achieved in a cost effective and commercially feasible
manner starting from a single tubular metallic blank. Therefore there may be a
need to form some space frame components having complex geometric configurations
by hydroforming a plurality of individual hydroformed members and then connecting
them together.
A rearward opening in a space frame for a sports utility-type vehicle (or a rearward
opening of other types of vehicles such as a station wagons or vehicles having
a hatchback-type opening) may be provided by a closed loop or ring-like structure.
A suitable ring-like structure must often have a complex geometry to provide suitably
shaped support structure for curved and rounded vehicle body sheet metal and glass
panels while providing an opening having a desired configuration. It is particularly
important, for example, that the rear opening defined by the rear ring-like structure
provide optimal driver field of vision when a driver looks into his or her central
rear view mirror. There is a need in the vehicle manufacturing industries for a
rear ring-like structure provided by a rearward ring assembly of tubular hydroformed
construction that can provide the complex geometry required for contemporary vehicles.
SUMMARY OF THE INVENTION
To meet the needs identified above, the invention provides a space frame for a
motor vehicle comprising a pair of laterally spaced, longitudinally extending side
rail structures, a pair of forward-most upright structures and a pair of roof rail
structures. Each forward-most upright structure is connected to a respective side
rail structure, thereby forming a pair of A pillars and a forward end of each roof
rail structure is connected to an upper end of an associated A pillar. A rearward
ring assembly is connected at upper portions thereof with the roof rail structures
and at bottom portions thereof with the side rail structures. The rearward ring
assembly includes a tubular hydroformed inverted U-shaped upper member, a pair
of tubular hydroformed side members and a cross structure. The tubular hydroformed
upper member has a cross portion and a pair of leg portions extending downwardly
from opposite ends of the cross portion. Each side member has a first end and a
second end and the first end of each side member is connected with a free end of
a respective leg portion of the upper member. The cross structure is rigidly connected
in ring-forming relation between the second ends of the side members. The side
rail structures, the A pillars, the roof rail structures and the rearward ring
assembly generally defining a space frame interior region and the rearward ring
assembly provides a rearward opening into the interior region. The side members
have lower portions thereof disposed closer to one another than the upper portions
thereof, the side members have lower portions thereof disposed more rearwardly
in a longitudinal frame direction in relation to the upper portions thereof.
Other objects, features, and advantages of the present invention will become
apparent from the following detailed description, the accompanying drawings, and
the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a motor vehicle space frame that is constructed
according to the principles of the invention and that includes a rearward ring
assembly constructed according to the principles of the present invention;
FIG. 2 shows an embodiment of a motor vehicle space frame that includes a cradle
assembly constructed according to the principles of the present invention;
FIG. 3 shows the cradle assembly in isolation;
FIG. 4 shows the space frame of FIG. 2 in side elevation view;
FIG. 5 shows a perspective view of the rearward ring assembly and a hydroformed
cross member in isolation;
FIG. 6 shows a perspective view of the rearward ring assembly in isolation;
FIG. 7 shows a rear elevational view of the rearward ring assembly in isolation;
FIG. 8 shows a side elevational view of the rearward ring assembly in isolation;
FIG. 9 shows and exploded view of the rearward ring assembly;
FIG. 10 shows a cross sectional view of a portion of the rearward ring assembly
taken through the line 10-10 of FIG. 7; and
FIG. 11 is a schematic cross sectional view of an exemplary hydroforming assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
FIG. 1 shows a space frame, generally designated
10, constructed according
to the principles of the present invention. The space frame
10 generally
includes a pair of laterally spaced, longitudinally extending side rail structures
12, a laterally extending rearward connecting structure
14 connected
between rearward portions of the side rail structures
12 and a pair of forward-most
upright structures
16. Each forward-most upright structure
16 is
connected to a respective side rail structure
12 and extends generally upwardly
therefrom to form a pair of A pillars. A pair of roof rail structures
18
are disposed on each side of the space frame
10 in generally vertically
spaced relation above the side rail structures
12 and are connected to the
space frame
10 in a manner described below.
The space frame
10 includes a rearward ring assembly
20. The rearward
ring assembly
20 is shown in isolation in FIGS. 5-9 and is described in
detail below. It can be appreciated from FIG. 1 that the rearward ring assembly
20 includes a tubular hydroformed inverted U-shaped upper member
22
and a pair of tubular hydroformed side members
24,
26. The side members
24,
26 are preferably of mirror image construction so only member
24 will be discussed in detail, but the discussion applies equally to member
26. Generally, in the present application, when a pair of structures or
members are identified as being of mirror image construction, only one structure
or member is discussed in detail, but the discussion applies to both. The upper
member
22 is an integral structure having a cross portion
28 and
a pair of legs
30 extending downwardly from junctures
31 at opposite
ends of the cross portion
28.
The pair of tubular hydroformed side members
24,
26 are each connected
at a first end thereof with a free end of a respective leg
30 of the upper
member
22. The cross portion
28 of the upper member
22 and
the pairs of connected legs and side members,
30,
24 and
30,
26, respectively, thereby define a cross portion and pair of leg portions,
respectively, of a tubular hydroformed inverted generally U-shaped assembly
32.
The cross portion of the U-shaped assembly
32 is identical to the cross
portion
28 of the upper member
22 and will therefore be referred
to by the same reference numeral. The leg portions of the U-shaped assembly
32
are designated
34 and
36 to facilitate discussion of the invention.
Cross structure, generally designated
38, is rigidly connected in ring-forming
relation between the second ends of the side members
24,
26 in a
manner best seen in FIGS. 5-7. The structure of the rearward ring assembly
20
in considered in detail below.
The manner in which the assembled rearward ring assembly
20 is connected
to the space frame
10 can be understood from FIG.
1. The cross structure
assembly
38 is connected to the rearward connecting structure
14
such that the cross structure assembly
38 extends laterally between the
side rail structures
12 and each leg portion
34,
36 of the
U-shaped assembly
32 is connected to an associated side rail structure
12
and extends generally upwardly with respect thereto, thereby forming a pair of
rearward-most or "D" pillars
34,
36. Each roof rail structure
18
is connected between an upper end of a respective A pillar
16 and an associated
juncture
31 of the rearward ring assembly
20. The side rail structures
12, the A pillars
16, the roof rail structures
18 and the
rearward ring assembly
20 generally define a space frame interior region
40 and the rearward ring assembly
20 provides a rearward opening
into the interior region
40.
Before the rearward ring assembly
20 is considered in detail, the construction
of the space frame
10 will be considered. The space frame
10 includes
a pair of tubular hydroformed upper longitudinal members
42,
44 which
are mounted on respective side rail structures
12. Each hydroformed member
is defined by an outwardly deformed tubular metallic wall fixed into a predetermined
surface configuration. The upper longitudinal members
42,
44 are
preferably of mirror image construction. Each upper longitudinal member
42
has a pillar-forming portion
46 and an integral longitudinally extending
portion
48. The pillar-forming portion
46 of each upper longitudinal
member
42 is connected to a respective side rail structure
12 and
extends upwardly therefrom to provide one A-pillar
16 of the pair of A-pillars
16. The longitudinally extending portion
48 of the upper longitudinal
member
42 extends rearwardly from the pillar-forming portion
46 and
a free end the longitudinally extending portion
48 is connected to an associated
juncture
31 of the rearward ring assembly
20. The longitudinally
extending portions
48 of the upper longitudinal members
42,
44
define the pair of roof rail structures
18.
The longitudinally extending portion
48 of each upper longitudinal member
42 also defines a longitudinal length between the forward-most or A pillar
and the associated rearward-most or D pillars
34,
36 (defined by
the leg portions
34,
36 of the tubular hydroformed U-shaped assembly
32 of the rearward ring assembly
20, as will become clear) on each
side of the space frame
10. The longitudinal length define by each integral
hydroformed longitudinally extending portion
48 minimizes the stacked tolerances
between the forward-most 16 and rearward-most pillars
34,
36 as taught
and described in detail in commonly assigned U.S. patent application Ser. No. 09/173,554
entitled HYDROFORMED SPACE FRAME AND METHOD OF MANUFACTURING THE SAME hereby incorporated
by reference in its entirety into the present application for all material disclosed therein.
A pair of first and second hydroformed inverted U-shaped members
50,
52
are mounted between the side rail structures
12. Each inverted U-shaped
member
50,
52 includes a cross portion
54,
56, respectively,
and a pair of leg portions
58,
60, respectively, extending integrally
from junctures at opposite ends of the cross portions
54,
56. Each
leg portion
58 of the first U-shaped member
50 is connected to a
respective side rail structure
12 and extends upwardly therefrom and each
juncture thereof is connected to the longitudinally extending portion
48
of an associated upper longitudinal member
42,
44. The leg portions
58 of the first U-shaped member
50 thereby define a pair of B pillars
of the space frame
10. Each leg portion
60 of the second U-shaped
member
52 is connected to an arched wheel well-forming portion
66
of a respective side rail structure
12 and extends upwardly therefrom and
each juncture of the second U-shaped member
52 is connected to the longitudinally
extending portion
48 of an associated upper longitudinal member
42,
44. The leg portions
60 of the second U-shaped member
52 thereby
define a pair of C pillars of the space frame.
Preferably each side rail structure
12 is comprised of a tubular
hydroformed forward side rail member
72,
74, respectively, and a
tubular hydroformed rearward side rail member
76,
78, respectively.
The forward side rail members
72,
74 are of mirror image construction
and the rearward side rail members
76,
78 are of mirror image construction.
The forward side rail member
72 has an essentially straight forward portion
82, an outwardly angled intermediate portion
84 and an essentially
straight rearward portion
86. The rearward side rail member
76 has
a short essentially straight forward portion
88, an upwardly arched intermediate
portion
90 (that forms the wheel well
66) and an essentially straight
rearward portion
92. The forward and rearward side rail members
72,
76 are preferably telescopically interengaged and welded together to form
a joint
80 therebetween.
A front bumper beam assembly
94 is laterally connected across the forward
ends of the forward side rail members
72,
74. The forward-most end
of each forward side rail member
72,
74 includes an integral hydroformed
collapsible forward terminal end portion
96 that is constructed and arranged
to collapse in a controlled, energy absorbing manner in the event of a front and
collision, thereby absorbing impact energy.
A rear bumper beam assembly
98 is connected across the rearward ends of
the rearward side rail members
76,
78. The rearward side rail members
76,
78 include integral hydroformed collapsible rearward terminal
end portions
100 that are constructed and which function similarly to the
collapsible forward terminal end portions
96.
A pair of connecting structures are connected laterally between the side rail
structures
12 forwardly and rearwardly, respectively, of the wheel wells
66.
Preferably, the connecting or cross structures are provided by intermediate and
rearward tubular hydroformed connecting or cross members
102,
104.
Preferably, the rearward tubular hydroformed connecting member
104 comprises
the rearward connecting structure
14. For discussion purposes, the hydroformed
cross members
102,
104 are also referred to as the intermediate and
rearward connecting structures
102,
104. The intermediate and rearward
connecting structures
102,
104 are connected laterally between the
side rail structures
12 forwardly and rearwardly, respectively, of the wheel
wells
66. Specifically, each end of each cross member
102,
104
is secured within pairs of aligned openings
101,
103, respectively,
formed in the rearward side rail members
76,
78 and are secured within
the openings by welding. A pair of longitudinally extending support structures
are each connected between the intermediate and rearward connecting structures
102,
104 and are preferably provided by a pair of tubular hydroformed
support members
105,
107. A notch
109 is formed in each end
of each support member
105,
107 and the support members
105,
107 are affixed to the space frame
10 by positioning each of the
intermediate and rearward connecting structures
102,
104 within a
notch
109 and welding the support members
105,
107 to the
connecting structures
102,
104.
A central cross structure, preferably provided by a tubular hydroformed central
member
111, is connected between the forward side rail members
72,
74. Preferably the central member
111 is connected between the side
rail members
72,
74 in a manner similar to the way in which members
102,
104 are connected between the rearward side rail members
76,
78. A central portion of the central member
111 is upwardly arched
to accommodate a portion of the drive train (not shown) of the assembled vehicle.
The space frame
10 includes a front structural assembly generally designated
106. The front structural assembly
106 includes a pair of front upper
side rail structures
108, a front cross structural assembly
110 and
a pair of side support structures
112. The front cross structural assembly
110 is connected laterally between forward end portions of the side rail
structures
12. Each front upper side rail structure
108 is connected
between the front cross structural assembly
110 and an intermediate portion
of a respective A pillar
16 so that the front upper side rail structures
108 are laterally space from one another and are generally vertically spaced
above forward portions of the side rail structures
12. Each side support
structure
112 is connected at one end to an intermediate portion of a respective
A pillar
16 and extends forwardly and downwardly therefrom and is connected
at another end opposite the one end to an associated side rail structure
12.
The front cross structural assembly
106 includes a front U-shaped structure
that is preferably provided by an integral tubular hydroformed front U-shaped member
114. The U-shaped member
114 has a cross portion
116 and a
pair of leg portions
118 that extend upwardly from junctures
120
at each end of the cross portion
116. Preferably each juncture
120
is welded to an associated side rail structure
12. Preferably a bracket
structure
122 is mounted in reinforcing relation between each side rail
structure
12 and an intermediate portion of an associated leg portion
118
of the U-shaped member
114. Preferably each bracket structure
122
is a metallic structure that has been shaped by stamping or other suitable method
and is secured to the space frame
10 by welding.
The front cross structure assembly
110 further includes an elongated essentially
straight front upper cross structure that is preferably provided by a tubular hydroformed
front upper cross member
124. Opposite end portions of the cross member
124 are flattened and are connected to end portions of leg portions
118
of the U-shaped member
114, preferably by welding.
Preferably the front upper side rail structures
108 are provided
by a pair of tubular hydroformed front upper side rail members
126,
128.
Each upper side rail member
126,
128 can be secured between the pillar
forming portion
46 of a respective upper longitudinal member
42,
44 and the associated leg portion
118 of the U-shaped member
114
by any appropriate means. Preferably a notch
130,
132 is formed in
each end of each upper side rail member
126,
128 and each member
126,
128 is secured to space frame
10 by welding.
Preferably each side support structure
112 is provided by a tubular
hydroformed side support member
134,
136. The side support members
134,
136 are of mirror image construction so only member
134
will be discussed in detail. The side support member
134 can be secured
to space frame
10 by any appropriate means. For example, preferably a notch
138,
140 is cut into each end of the side support member
134
and the member
134 is secured to the space frame
10 by positioning
the forward side rail member
72 in the notch
138 and the pillar forming
portion
46 of the upper longitudinal member
42 in the notch
140
and welding. The side support members
134,
136 reinforce the frame
10. Specifically the members
134,
136 strengthen the front
structure assembly
106 and resist deformation of the front end of the vehicle
in the event of a head on collusion.
An elongated forward cross structure that is preferably provided by a tubular
hydroformed forward cross member
144 extends laterally between and is secured
between the forward side rail members
72,
74. Preferably, the forward
cross member
144 is secured between the side rail members
72,
74
in manner similar to the way in which hydroformed connecting members
102,
104 are secured between side rail members
76,
78, although
any suitable means can be used.
A pair of forward upper cross structures are secured between the pillar forming
portions
46 of the upper longitudinal members
42,
44 and are
preferably provided by a pair of tubular hydroformed forward upper cross members
146,
148. Preferably a notch
150,
151 is cut in each
end of each forward upper cross member
146,
148, respectively, so
that a single wall portion extends outwardly in cantilevered fashion from each
end of each cross member
146,
148 and the cross members
146,
148 are secured between the upper longitudinal members
42,
44
by placing the upper longitudinal members within respective notches so that the
cantilevered wall portions are in adjacent and overlying relation therewith and
then welding.
FIG. 2 shows a second embodiment of a space frame, generally designated
150.
The space frame
150 is identical to the space frame
10 except that
the space frame
150 includes a cradle assembly
152. The portions
of the space frame
150 that are identical to portions of the space frame
10 are designated by identical reference numbers and are not commented upon
the further in the description of the space frame
150.
The cradle assembly
152 is shown in FIG. 2 mounted to the space frame
150 and is shown in FIG. 3 in isolation. As best appreciated from FIG. 3,
the cradle assembly
152 includes a pair of elongated cradle support structures
that are preferably provided by a pair of elongated tubular hydroformed cradle
support members
154,
156 (of mirror image construction). The cradle
assembly
152 further includes a pair of U-shaped cradle structures which
are preferably provided by a pair of tubular hydroformed U-shaped cradle members
158,
160. Each U-shaped cradle member
158,
160 has
a pair of leg portions
162,
164, respectively, extending from an
integral cross portion
166,
168, respectively. Preferably notches
170,
172 are formed in each leg portion
162,
164, respectively,
of the U-shaped cradle members
158,
160. The cradle support members
154,
156 are secured to the U-shaped cradle members
158,
160
by positioning the cradle support members
154,
156 within the notches
170,
172 and then welding. The cradle assembly
152 is used
to mount a rear wheel assembly (which is not shown and which includes a rear wheel
suspension system) to the space frame
10 when the vehicle is assembled.
A plurality of brackets
174,
176 are secured to the U-shaped cradle
members
158,
160 to facilitate attachment of the rear wheel assembly
to the vehicle.
The manner in which the cradle assembly
152 is secured to the space frame
150 can be appreciated from FIGS. 2 and 4. The cradle support structures
(provided by the cradle support members
154,
156 in the exemplary
embodiment of the space frame
150) are laterally spaced and each is connected
between the intermediate and rearward connecting structures
102,
104.
More particularly, as best seen in FIG. 4, each end portion of each cradle support
member
154,
156 is secured to a bottom surface portion of a respective
connecting member
102,
104. The cradle support members
154,
156 can be secured to the connecting members
102,
104 by welding,
by bolts, or by any other suitable means. The U-shaped cradle structures (provided
by the cradle members
158,
160) are longitudinally spaced and, as
mentioned, each leg portion
162,
164 of the pair of leg portions
of each U-shaped cradle structure
158,
160, respectively, is connected
to a respective one of the pair of cradle support structures
154,
156.
It can be understood from FIG. 4 that when a rear wheel assembly is secured to
the cradle assembly
152, each rear wheel (not shown) of the assembled vehicle
is disposed generally below a respective wheel well
66. Preferably the cradle
assembly
152 is provided to facilitate mounting of a rear wheel assembly
to the space frame. It is within the scope of the invention to provide an appropriately
constructed cradle assembly to facilitate mounting of a front wheel assembly.
The rearward ring assembly
20 is shown in isolation in FIGS. 6 and 8 and
is shown in isolation mounted with respect to the rearward connecting structure
14 in FIG.
5. The construction of the reward ring assembly
20
can be best understood from the exploded view of FIG.
9. As mentioned above,
because the tubular hydroformed side members
24,
26 are of mirror
image construction, only the member
24 will be discussed in detail. Preferably,
an upper terminal end
180 of the side member
24 is of reduced diameter
so that the side member
24 can be telescopically received within an end
portion of the associated tubular leg portion
30 of the hydroformed upper
member
22. Preferably the telescopically interengaged hydroformed members
22,
24 are secured together by welding. It can be appreciated, however,
that the hydroformed members
22,
24 can be rigidly affixed together
by any suitable means.
The cross structure
38 is preferably comprised of an assembly of metallic
structures that have been shaped by stamping, although any suitable metal shaping
or metal forming means can be used to construct the metallic structures of the
cross structure
38. The cross structure
38 comprises an assembly
of stamped members assembled into a tubular configuration. The construction of
the cross structure assembly
38 can be best understood from the exploded
view of FIG.
9 and the cross sectional view of FIG.
10.
More particularly, the cross structure assembly
38 includes a pair of
upper cross elements
182,
184, an intermediate cross element
186
and a lower cross element
188. Preferably each cross element
182,
184,
186,
188 is of one-piece stamped sheet metal construction,
although any suitable metal shaping or metal forming method can be used to construct
each element. As best seen in FIG. 9, preferably the upper cross elements
182,
184 are of mirror image construction (so only element
182 will be
discussed in detail).
The cross element
182 is shaped to define integrally an upwardly facing
surface
190 (defined by a central wall portion
191), an essentially
vertically extending rearward wall portion
192 and a forwardly extending
flange portion
194 that extends perpendicularly forwardly from an essentially
vertically extending forward wall portion
196. A recessed area
198
that is constructed and arranged to receive a lower terminal end
200 of
the side member
24 is generally defined by the forward, central and rearward
wall portions
196,
191 and
192 of the cross element
182.
The lower end portion
200 of the side member
24 is of reduced diameter
so that when the lower portion
200 of the side member
24 is disposed
within the recessed area
198 of the cross element
182, the outwardly
facing surfaces defined by the wall portions
196,
191,
192
of the cross element
182 are essentially flush with respective adjacent
wall surfaces defined by a lower intermediate portion
202 of the side member
24. Preferably, therefore, the wall thickness of the sheet metal used to
form the cross element
182 is approximately equal to the depth of the recessed
end portion
200 of the side member
24 relative to the lower intermediate
portion
202 thereof.
The intermediate cross element
186 is preferably an essentially L-shaped
structure (in cross section as best seen in FIG. 10) of stamped sheet metal construction
that includes an essentially vertically extending rearward wall portion
206
and a forwardly and essentially horizontally extending wall portion
208.
The lower cross element
188 is preferably of stamped sheet metal construction
and includes essentially vertically extending forward and rearward wall portions
210,
212, respectively, and a central wall portion
214 extending
integrally therebetween. The details of the construction of the intermediate and
lower cross elements
186,
188 can best be understood after examining
the construction of the preferred embodiment of the rearward connecting or cross
structure
14, which preferred embodiment is provided by the tubular hydroformed
connecting member
104.
The assembled rearward ring assembly
20 is shown mounted to the hydroformed
connecting member
104 in isolation in FIG. 5 to illustrate the manner in
which the cross structure assembly
38 of the rearward ring assembly
20
is connected to the tubular hydroformed connecting member
104. The rearward
ring assembly
20 defines an opening
220 into the interior region
40 of the space frame
10,
250. As best seen in FIG. 5, the
tubular connecting member
104 is mounted to the rearward ring assembly
20
at a position generally below the opening
220. The tubular connecting member
104 has straight, horizontally extending terminal end portions
222,
a straight, horizontally extending central portion
224, and angled transition
portions
223 each extending tubularly integrally between each terminal end
portion
222 and an adjacent end of the central portion
224. The central
portion
224 has a length approximately equal to the width of the lowermost
portion of the rearward opening
220 and the cross structure assembly
38
is connected to the tubular connecting member
104 such that the central
portion
224 thereof is spaced vertically downwardly from the rearward opening
220.
Returning again to a consideration of the structure of the intermediate
and lower cross elements
186,
188 as best shown in FIG. 9, it can
be appreciated that end portions of the wall portion
206 of the intermediate
cross element
186 are tapered at
228 and opposite end portions of
the central wall portion
214 of the lower cross element
188 are angled
upwardly at
230 so that the cross structure assembly
38 of the assembled
rearward ring assembly
20 is shaped to receive the hydroformed tubular connecting
member
104 and thereby facilitate welded engagement between the connecting
