UNITARY HYDROFORMED ROOF SUPPORT PILLAR

POTEAU MONOLITHIQUE HYDROFORME DE SUPPORT DE TOIT

English Abstract

A one-piece B-pillar having a front flange and a rear flange formed on an upper portion of the B-pillar. The front and rear flanges extend forwardly and rearwardly from a trapezoidal section of the B-pillar. An inner concave portion is provided in a lower portion of the B-pillar. The one-piece B-pillar is secured to the outer and upper surfaces of a roof rail and to the outer surface of a rocker to provide side impact strength. The B-pillar is hydroformed in one-piece to provide superior strength for roof crush performance. The tubular portion of the B-pillar is partially collapsed to form a trapezoidal section in the upper portion of the B-pillar.

French Abstract

Un pied milieu monobloc ayant une bride avant et une bride arrière formées sur une partie supérieure du pied milieu. Les brides avant et arrière s'étendent vers l'avant et l'arrière à partir d'une section trapézoïdale du pied milieu. Une partie concave interne est fournie dans une partie inférieure du pied milieu. Le pied milieu monobloc est fixé aux surfaces externes et supérieures d'un brancard de pavillon et à la surface externe d'un bas de caisse pour assurer une résistance aux chocs latéraux. Le pied milieu est hydroformé d'un seul bloc afin de conférer au toit une résistance supérieure à l'écrasement. La partie tubulaire du pied milieu est partiellement affaissée pour former une section trapézoïdale dans la partie supérieure du pied milieu.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A vehicle roof support assembly, comprising:
a roof rail; a rocker panel;
a one-piece, partially hollow support pillar having
an inner wall, an outer wall, a front wall and a rear
wall, the support pillar having a tubular lower section
that extends upwardly from the rocker panel, an upper
section that extends downwardly from the roof rail, the
upper section has a convergent tubular shape formed by the
inner wall, the outer wall, the front wall, and the rear
wall that converge in the vertically upward direction, the
convergent tubular section having flanges extending
longitudinally from the front wall and the rear wall,
wherein the flanges extending from the front wall and the
rear wall begin at an intermediate point on the front wall
and rear wall and increase in longitudinal extent in the
vertical vehicle direction, the upper end of the
convergent tubular section terminating in a top portion
that includes only the inner wall and the outer wall that
are compressed together and that is assembled to an outer
surface and an upper surface of the roof rail.
2. The vehicle roof support assembly of claim 1
wherein the tubular lower section terminates in a
compressed rocker attachment flange that includes only an
inner wall and an outer wall and that is assembled to an
outer surface of the rocker panel.
3. The vehicle roof support assembly of claim 2
wherein the rocker attachment flange extends around to the
rocker panel.
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4. The vehicle roof support assembly of claim 3
wherein the rocker attachment flange spot welded to the
rocker panel.
5. The vehicle roof support assembly of claim 1
wherein the tubular lower portion has an inner wall that
defines a concave portion.
6. The vehicle roof support assembly of claim 1
wherein the roof rail defines an indentation relative to
an outer surface of the roof onto which the top portion of
the support pillar is received.
7. The vehicle roof support assembly of claim 1
wherein the top portion has at least two layers of metal
and wherein at least one layer of metal is removed in
limited areas to facilitate spot welding the roof rail to
the roof rail.
8. The vehicle roof support assembly of claim 1
further comprising a roof bow extending in a transverse
vehicle direction and wherein an end flange of the roof
bow overlaps the roof rail and is welded to the end
flange.
9. A roof support pillar for a vehicle that supports
the vehicle roof over a passenger compartment, the pillar
being disposed adjacent a rear edge of a vehicle door for
access to a front seat, the vehicle having a roof rail and
a rocker panel, the roof support pillar comprising:
a unitary and partially tubular member having a
closed roof rail flange on an upper end and a closed
rocker panel flange on a lower end, a front flange
extending forwardly from the tubular member beginning at
an intermediate point along the length of the tubular
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member and increasing in forward extent in the vertical
direction, and a rear flange extending rearwardlv from the
tubular member beginning at an intermediate point along
the length of the tubular member and increasing in
rearward extent in the vertical direction;
wherein the top portion is assembled to the roof rail
on a surface of the roof rail that is on the opposite side
of the roof rail from the passenger compartment; and
wherein the rocker attachment flange is assembled to
the rocker panel on a surface of the rocker panel that is
on the opposite side of the rocker panel from the
passenger compartment.
10. The roof support pillar of claim 9 wherein the
rocker attachment panel flange may be spot welded to the
rocker panel.
11. The roof support pillar of claim 9 wherein the
pillar has an inner wall that defines a concave portion.
12. The roof support pillar of claim 9 wherein the
roof rail defines an indentation relative to an outer
surface of the roof onto which the top portion is
received.
13. The roof support pillar of claim 9 wherein the
top portion has at least two layers of metal and wherein
at least one layer of metal is removed in limited areas to
facilitate spot welding the top portion to the roof rail.
14. The roof support pillar of claim 9 further
comprising a roof bow extending in a transverse vehicle
direction and wherein an end flange of the roof bow
overlaps the top portion and is welded to the end flange.
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15. A roof support pillar disposed between a front
row of seats and a rear row of seats of a vehicle, the
roof support pillar comprising:
a one-piece hollow tubular body having a top portion
on an upper end and a rocker attachment flange on a lower
end, wherein an upper portion of the tubular body portion
has a tubular rectilinear cross-section at a beltline of
the vehicle and further wherein the rectilinear cross-
section of the upper portion of the tubular body portion
is reduced in the vertical vehicle direction, and wherein
the upper portion of the tubular body portion has a
forward extending flange and a rearward extending flange,
wherein the forward and rearward extending flanges begin
above the beltline and increase in longitudinal extent in
the vertical vehicle direction;
a seat belt retractor cavity being formed in the
tubular portion and adjacent to the lower end; and
wherein the top portion is welded to an outer surface
of the roof rail and the rocker attachment flange is
welded to an outer surface of the rocker.
16. The roof support pillar of claim 15 wherein the
top portion, the forward extending flange, and the
rearward extending flange are formed by collapsing a
portion of a tubular member from which the tubular body
portion is formed in a hydroforming operation.
17. The roof support pillar of claim 15 wherein the
rocker attachment flange on the lower end of the tubular
body portion is formed by collapsing a portion of a
tubular member from which the tubular body portion is
formed.
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Description

CA 02569999 2013-07-03
UNITARY HYDROFORMED ROOF SUPPORT PILLAR
10 BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a unitary
hydroformed roof support pillar for a vehicle.
2. Background Art
Roof support pillars support the roof of a vehicle
and are located between the windows and doors of a vehicle.
Roof support pillars are frequently identified as A, B, C
and in some instances D-pillars depending on the vehicle
style. A B-pillar is generally located immediately behind
the front door of a vehicle. The B-pillar is an important
element in determining roof strength and the degree of side
impact intrusion.
Passenger vehicle designs are tested for roof
strength and side impact strength. Conventional B-pillars
are fabricated as multiple stamped sheet metal parts that
are generally spot welded together. It is possible to
improve the strength of conventional B-pillars by forming
the sheet metal parts from high grade material, such as dual
phase and boron steels. B-pillars may also be made stronger
by using thicker gauge sheet metal components. However, the
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use of high strength alloys and thicker sheet metal may
increase the weight of a vehicle and also increases the cost
to manufacture the B-pillar. Even with the use of thicker
alloy components, B-pillars of conventional design may not
always meet stringent test requirements for roof strength
and side impact performance.
It has been proposed to use hydroformed tubes to
fabricate vehicles having space frame construction in, for
example, U.S. Patent No. 6,282,790. This patent proposes
integrally forming two B-pillars and a roof bow in a single
U-shaped piece that is connected to the top surface of two
tubular rockers. This proposed design presents a
manufacturing problem in that the closed box section of the
parts precludes spot welding assembly techniques. Also, the
longitudinal thickness of the hydroformed tube portion
between vehicle doors is objectionable from a styling
standpoint.
Other proposed designs for hydroformed B-pillars
are disclosed in published U.S. patent application US
2004/0239091 Al and published U.S. patent application US
2005/0023865 Al. However, these proposed designs require
reinforcing brackets to connect the B-pillar to a rocf rail.
Tn addition, the B-pillar is not reinforced by the roof rail
and rocker panel members. In the event of a side impact
intrusion, the connection of the B-pillar to the roof rail
and rocker must rely upon welds for structural integrity.
In addition, the width of the B-pillar in the longitudinal
vehicle direction limits styling and adversely impacts
vehicle appearance.
The present invention is directed to solving the
above problems and other problems relating to the
manufacture of a roof support pillar with minimum part count
and improved roof crush and side impact performance. Prior
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art methods of hydroforming roof support pillars face
technical barriers relating to the hydroforming procedure,
methods of joining hydroformed components and packaging
constraints. In particular, it is difficult for a
hydroformed tube that has a uniform perimeter to accommodate
desired section variations for vehicle styling.
Prior art multiple-piece B-pillars are designed to
connect the roof rail, rocker and body outer panels.
Connection between these elements are critical for vehicle
body strength and noise, vibration and hardness (NVH) joint
stiffness. Packaging constraints for B-pillars include
providing clearance for seatbelt retractors and adequate
mounting surfaces for door latch and hinge reinforcements.
The above problems and design challenges are
addressed by applicants' invention as summarized below.
SUMMARY OF THE INVENTION
According to one aspect of the present invention a
roof support assembly is provided in part by a roof rail and
rocker panel that are connected by a one piece partially
hollow support pillar. The support pillar has an inner
wall, an outer wall, a front wall and a rear wall. The
support pillar has a tubular lower section that extends
upwardly from the rocker panel and an upper section that
extends upwardly from the lower section. The upper section
has a convergent tubular shape formed by the inner wall, the
outer wall, the front wall and the rear wall that converge
in the vertical direction. The convergent tubular section
has flanges extending longitudinally from the front wall and
the rear wall. The upper end of the convergent tubular
section terminates in a compressed roof rail flange that
includes only the inner wall and the outer wall. The
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CA 02569999 2006-12-04
compressed roof rail flange is assembled to an outer surface
and upper surface of the roof rail.
According to another aspect of the present
invention, a roof support pillar for a vehicle is provided
for supporting a vehicle roof over a passenger compartment.
The pillar is disposed adjacent a rear edge of the vehicle
door that provides access to a front seat of the vehicle.
The vehicle has a roof rail and a rocker panel that are
interconnected by the roof support pillar. The roof support
pillar comprises a unitary and partially tubular member
having a closed roof rail flange on an upper end and a
closed rocker panel flange on a lower end. The roof rail
flange is assembled to the roof rail on a surface of the
roof rail that is on the opposite side of the roof rail from
the passenger compartment. The rocker flange is assembled
to the rocker panel on a surface of the rocker panel that is
on the opposite side of the rocker panel from the passenger
compartment.
According to another aspect of the present
invention a roof support pillar that is disposed between a
front row of seats and a rear row of seats of the vehicle is
provided. The roof support pillar comprises a hollow
tubular body having a roof rail flange on the upper end and
a rocker flange on the lower end. A seatbelt retractor
cavity is formed in the tubular portion adjacent to the
lower end of the pillar. The roof rail flange is welded to
an outer surface of the roof rail and the rocker flange is
welded to an outer surface of the rocker.
According to other aspects of the present
invention, the support pillar may have a tubular lower
section that terminates in a compressed rocker flange that
includes only an inner wall and an outer wall and that is
assembled to an outer surface of the rocker panel. The
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CA 02569999 2006-12-04
rocker flange may extend around to the bottom surface of the
rocker panel. The rocker flange may have a spot weld flange
disposed below the rocker panel. The tubular lower portion
of the support pillar may have an inner wall that defines a
concave portion in which a seatbelt retractor may be
assembled.
The roof rail defines an indentation relative to
an outer surface of the roof onto which the roof rail flange
of the support pillar is received. The roof rail flange
preferably has at least two layers of metal wherein at least
one layer of metal is removed from certain portions to
facilitate spot welding the roof rail flange to the roof
rail. The roof rail flange overlaps and is welded to an end
flange of a transversely extending roof bow.
According to another aspect of the invention, an
upper portion of the tubular body portion may have a tubular
rectilinear cross section at a belt line of the vehicle.
The rectilinear cross section of the upper portion of the
tubular body portion is reduced in the vertical vehicle
airection. The forwardly extending flange and rearwardly
extending flange of the upper portion of the tubular body
may increase in longitudinal extent along the vertical
vehicle direction. The forward extending flange and
rearward extending flange are formed by collapsing a portion
of the tubular member from which the tubular portion is
formed in the hydroforming operation.
According to further aspects of the invention, the
rocker flange on the lower end of the tubular body portion
may be formed by collapsing a portion of the tubular member
from which the tubular body portion is formed.
These and other aspects of the present invention
will be better understood in view of the attached drawings
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CA 02569999 2006-12-04
and following detailed description of the illustrated
embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a fragmentary side elevation view of a
B-pillar, roof rail, roof bow and rocker;
Figure 2 is a side elevation view of a B-pillar;
Figure 3 is a cross-sectional view taken along the
line 3-3 in Figure 1;
Figure 4 is a cross-sectional view taken along the
line 4-4 in Figure 1;
Figure 5 is a cross-sectional view taken aLong the
line 5-5 in Figure 1;
Figure 6 is a fragmentary perspective view of a B-
billar, roof rail and roof bow; and
Figure 7 is a fragmentary front elevation view of
a B-pillar, roof rail and roof bow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
Referring to Figure 1, a one-piece B-pillar 10 is
shown attached to a roof rail 12 and roof bow 14. The B-
pillar 10 is also attached to a rocker 18.
The B-pillar 10 has a middle portion 20 and an
upper portion 22 extending upwardly from the middle portion
20. A lower portion 24 extends downwardly from the middle
portion 20. Referring to Figure 3, which is a cross section
taken through the middle portion 20, the cross section of
the B-pillar 10 in that area includes a front wall 28, a
rear wall 30, and outer wall 32 and an inner wall 34. The
four walls 28-34 form a substantially rectangular box shaped
beam.
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Referring to Figure 4, a cross section taken
through the upper portion 22 of the B-pillar 10 is
illustrated. A front flange 36 and a rear flange 38 extend
forwardly and rearwardly, respectively, from a trapezoidal
section 40. The trapezoidal section 40 extends upwardly as
a continuation of the walls 28-34 with the front wall 28 and
rear wall 30 converging toward the outer wall 32 in the
vertical direction. The upper portion 22 of the B-pillar 10
terminates in a flat top portion 42. The flat top portion
42 extends on the outer and upper sides of the roof rail 12
and is received below the roof bow 14.
Referring to Figure 5, a cross section taken
through the lower portion 24 of the B-pillar 10 is shown to
define an inner concave portion 46. The inner concave
portion 46 may receive a seat belt retractor mechanism (not
shown) if desired.
Referring to Figure 2, the one-piece B-pillar 10
is shown in conjunction with the roof bow 14. The B-pillar
10 includes on its lower portion 24 the inner concave
portion 46 that leads to a rocker attachment flange 48 at
its lower end. The B-pillar includes D-ring attachment
holes 50 and a wiring duct access hole 52.
Referring to Figure 6, the connection between the
B-pillar 10, roof rail 12 and roof bow 14 is shown in
greater detail. The upper portion 22 of the B-pillar 10
includes a front flange 36 and a rear flange 38 that are
formed in a hydroforming operation by compressing the beam
from which the B-pillar is formed. The upper portion 22 of
the B-pillar 10 may be seated in an indentation 56 formed on
the roof rail 12. Ribs 58 may be formed on the roof bow 14
to provide the desired degree of rigidity and reinforce the
roof structure.
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A plurality of weld access areas may be provided
in front and rear flanges 36 and 38 by removing a single
layer area 60 of the tubular blank prior to the hydroforming
operation. The single layer area 60 facilitates welding
operations for joining the roof rail to the B-pillar.
Referring to Figure 7, the B-pillar 10 is secured
to a body side outer panel (not shown). The B-pillar is
joined to the roof rail 12 and the roof bow 14 at its upper
end. Hinge hardware holes 54 or other door hardware such as
striker plates or locking plates may be secured to the front
wall 28 and rear wall 30 of the B-pillar by means of holes
such as hinge hardware holes 54. The upper end of the B-
pillar includes the flat top portion 42 that extends over
the roof rail 12 and under the roof bow 14 as previously
described.
While the best mode for carrying out the
Lnvention has been described in detail, those familiar with
the art to which this invention relates will recognize
various alternative designs and embodiments for practicing
the invention as defined by the following claims.
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Representative Drawing