U.S. patent application number 10/163838 was filed with the patent office on 2003-12-11 for bumper with integrated energy absorber and beam.
Invention is credited to Evans, Darin.
Application Number | 20030227184 10/163838 |
Document ID | / |
Family ID | 29710063 |
Filed Date | 2003-12-11 |
United States Patent
Application |
20030227184 |
Kind Code |
A1 |
Evans, Darin |
December 11, 2003 |
BUMPER WITH INTEGRATED ENERGY ABSORBER AND BEAM
Abstract
A bumper system includes a tubular beam with flattened end
sections, and further includes an energy absorber having a rear
recess mateably receiving the tubular beam in a nested
relationship, with the recess also including flat mating surfaces
engaging the flattened end sections. Mounts engage a rear of the
flattened end sections, and fasteners secure the tubular beam and
energy absorber to the mounts. In one modified bumper system,
corner sections on the energy absorber are shaped to slidingly
engage a side surface of the mount and simultaneously an end of the
beam upon corner impact of the vehicle. In another modified bumper
system, offset ends of the tubular beam fit into a recess in an
energy absorber, with its center section being between vehicle
mounts.
Inventors: |
Evans, Darin; (Wixom,
MI) |
Correspondence
Address: |
PRICE HENEVELD COOPER DEWITT & LITTON
695 KENMOOR, S.E.
P O BOX 2567
GRAND RAPIDS
MI
49501
US
|
Family ID: |
29710063 |
Appl. No.: |
10/163838 |
Filed: |
June 6, 2002 |
Current U.S.
Class: |
293/120 |
Current CPC
Class: |
B60D 1/56 20130101; B60R
2019/1866 20130101; B60R 2019/1826 20130101; B60R 19/24 20130101;
B60D 1/243 20130101; B60R 2019/1813 20130101; B60R 2019/1806
20130101; B60R 2019/188 20130101; B60D 1/52 20130101; B60R 19/18
20130101 |
Class at
Publication: |
293/120 |
International
Class: |
B60R 019/03 |
Claims
I claim:
1. A bumper system comprising: a tubular beam with front, rear,
top, and bottom walls, the front and rear walls being reformed at
ends of the tubular beam to form flattened end sections; an energy
absorber having a rear surface with a recess mateably receiving the
tubular beam, the recess including mating flat surfaces engaging a
front of the flattened end sections; mounts engaging a rear of the
flattened end sections; and fasteners securing the tubular beam and
energy absorber to the mounts.
2. The bumper system defined in claim 1, wherein the mounts include
flat plates that engage the rear of the flattened end sections.
3. The bumper system defined in claim 1, wherein the energy
absorber includes a rearwardly-facing U-shaped section of non-foam
polymeric material that defines top and bottom portions of the
recess.
4. The bumper system defined in claim 3, wherein the energy
absorber includes foam sections of material that cover at least
three sides of the rearwardly-facing U-shaped section.
5. The bumper system defined in claim 3, wherein the U-shaped
section defines a horizontal rail on the energy absorber.
6. The bumper system defined in claim 1, wherein the energy
absorber includes structure adapted to support headlight cans and
further includes through-holes for passing light from the headlight
cans.
7. The bumper system defined in claim 1, wherein the fasteners
include shafts that extend through the energy absorber and through
the beam ends into the mounts.
8. The bumper system defined in claim 1, wherein the energy
absorber includes corner sections forming at least one
honeycomb-shaped structure for absorbing impact energy during a
vehicle crash, the corner sections extending around and rearward of
the ends of the beam.
9. The bumper system defined in claim 8, wherein the corner
sections include a portion located proximate the mounts, the corner
sections being configured to flex, engage and slide on a side of
the mounts during a corner impact that is directed along a line
angled with respect of a length of the mounts, and being configured
to engage and crush against the mounts during a front impact that
is parallel a length of the mounts.
10. A bumper system for a vehicle comprising: a beam having front,
rear, top, and bottom walls defining a tubular center section and
having end sections; a one-piece energy absorber having an absorber
center section with a rear-facing recess mateably receiving the
tubular center section and engaging portions of the front, top and
bottom walls; and further having corner sections with an interior
surface located proximate an outer end of the end sections of the
beam; mounts engaging a rear of the end sections, the interior
surface of the corner sections being positioned to engage the outer
end of the beam and to simultaneously engage an outer side surface
of the mounts when the vehicle experiences a corner impact; and
fasteners that secure the tubular beam and energy absorber to the
mounts.
11. The bumper system defined in claim 10, wherein the corner
sections include a portion located proximate the mounts, the corner
sections being configured to flex, engage, and slide on a side of
the mounts during a corner impact that is directed along a line
angled with respect of a length of the mounts, and being configured
to engage and crush against the mounts during a front impact that
is parallel a length of the mounts.
12. The bumper system defined in claim 10, wherein the energy
absorber includes a rearwardly-facing U-shaped section of non-foam
polymeric material that defines top and bottom portions of the
recess.
13. The bumper system defined in claim 12, wherein the energy
absorber includes foam sections of material that cover at least
three sides of the rearwardly-facing U-shaped section.
14. The bumper system defined in claim 12, wherein the U-shaped
section defines a horizontal rail on the energy absorber.
15. The bumper system defined in claim 10, wherein the energy
absorber includes structure adapted to support headlight cans and
further includes through-holes for passing light from the headlight
cans.
16. The bumper system defined in claim 10, wherein the fasteners
includes shafts that extend through the energy absorber and through
the beam ends into the mounts.
17. The bumper system defined in claim 10, wherein the corner
sections form at least one honeycomb-shaped structure for absorbing
impact energy during a vehicle crash, the corner sections extending
around and rearward of the end sections of the beam.
18. A bumper system for a vehicle having a passenger compartment,
comprising: a tubular bumper beam having a tubular bumper beam that
includes a center section, end sections, and bent interconnecting
sections that interconnect each end section with an end of the
center section, the center section being at least 25% of a length
of the bumper beam and defining a longitudinal primary centerline,
and the end sections being at least 15% of the length and each
defining a secondary centerline that extends parallel the primary
centerline; an energy absorber with at least one recess shaped to
receive a portion of the tubular bumper beam; and mounts adapted
for attachment to a vehicle and that are attached to the end
sections, the secondary centerline being spaced horizontally from
the primary centerline when in a vehicle-mounted position, with the
center section being located partially between the mounts and
closer to the passenger compartment than the end sections.
Description
BACKGROUND
[0001] The present invention relates to vehicle bumper systems, and
more particularly relates to a bumper system having an integrated
energy absorber and beam, and also relates to novel beam
constructions such as are shaped for engagement with mating energy
absorbers.
[0002] Bumper systems using integrated energy absorber and bumper
beam arrangements are desired to improve assembly of bumper systems
to vehicles, to minimize the number and types of mechanical
fasteners overall, and to simplify tooling. In particular, it is
desirable to provide a design where the beam and energy absorber
can be assembled off-line of the main vehicle assembly line into a
unitary subassembly, and then manipulated as a unit for attachment
to the vehicle. Also, it is desirable to attach fascia to the
subassembly, and to integrate and attach other components to the
subassembly, such as headlights, grilles, and other functional and
ornamental components. At the same time, impact durability and
enhanced energy absorption continue to be high priority items in
bumper systems, and accordingly, any subassembly should preferably
not detract from the same.
[0003] In addition to the above, many vehicle manufacturers and
some insurance groups and government entities are pressing for
improved crashworthiness of vehicles, and also for bumper systems
that will provide for better pedestrian safety. Longer bumper
strokes with lower initial energy absorption rates have the
possibility of satisfying these desires, but this can result in
energy absorbers that are physically larger in size than present
bumper systems, and that are not easy to package and carry at a
front of the vehicle. Thus, new integrated bumper systems are
desired to deal with the conflicting functional and design
requirements.
[0004] Improvements are also desired in rear bumper systems on
vehicles. In particular, vehicle manufacturers are looking
increasingly at energy absorbers for rear bumper systems that are
not dissimilar in shape and function to energy absorbers for front
bumper systems. However, the energy absorber of any such rear
bumper system must be integrated into the bumper system such that
it does not interfere with other functional and aesthetic
requirements at a rear of the vehicle. For example, many rear
bumper systems include a step, and/or are adapted to support a ball
hitch for hauling a trailer.
[0005] Accordingly, bumper systems are desired solving the
aforementioned problems and having the aforementioned
advantages.
SUMMARY OF THE PRESENT INVENTION
[0006] In one aspect of the present invention, a bumper system
includes a tubular beam with front, rear, top, and bottom walls;
the front and rear walls being reformed at ends of the tubular beam
to form flattened end sections. The bumper system further includes
an energy absorber having a rear surface with a recess mateably
receiving the tubular beam, the recess including mating surfaces
engaging a front of the flattened end sections. Vehicle mounts
engage a rear of the flattened end sections, and fasteners secure
the tubular beam and energy absorber to the mounts.
[0007] In another aspect of the present invention, a bumper system
includes a beam having front, rear, top, and bottom walls defining
a tubular center section and having end sections. The bumper system
further includes a one-piece energy absorber having an absorber
center section with a rear-facing recess mateably receiving the
tubular center section and engaging portions of the front, top and
bottom walls; and further having corner sections with an interior
surface located proximate an outer end of the end sections of the
beam. Mounts engage a rear of the end sections, with the interior
surface of the corner sections being positioned to engage the outer
end of the beam and to simultaneously engage an outer side surface
of the mounts when the vehicle experiences a corner impact.
Fasteners secure the tubular beam and energy absorber to the
mounts.
[0008] In yet another aspect of the present invention, a bumper
system for a vehicle having a passenger compartment includes a
tubular bumper beam having a tubular bumper beam that includes a
center section, end sections, and bent interconnecting sections
that interconnect each end section with an end of the center
section, with the center section being at least 25% of a length of
the bumper beam and defining a longitudinal primary centerline, and
the end sections being at least 15% of the length. The end sections
each define a secondary centerline that extends parallel the
primary centerline, with the secondary centerline being spaced
horizontally from the primary centerline when in a vehicle-mounted
position, and with the center section being located partially
between the mounts and closer to the passenger compartment than the
end sections. An energy absorber is provided that includes at least
one recess shaped to receive a portion of the tubular bumper beam.
Mounts are provided that are adapted for attachment to a vehicle
and that are attached to the end sections.
[0009] An advantage of the present bumper systems is that some of
the traditional front-end support structure can be simplified or
eliminated. For example, the present inventive bumper system can
include an energy absorber with portions that support the
front-of-vehicle fascia in areas in front of the vehicle hood. This
allows the front end support structure of the vehicle to e
simplified, such as by eliminating fascia-supporting struts, by
eliminating forwardly-extending flanges on the radiator cross
support, by reducing the strength requirements on the radiator
cross support and/or by eliminating or reducing strength
requirements on a vehicle's front end panel.
[0010] These and other aspects, objects, and features of the
present invention will be understood and appreciated by those
skilled in the art upon studying the following specification,
claims, and appended drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a perspective view of a bumper system embodying
the present invention, including an energy absorber and a tubular
beam with flattened ends positioned within a rear-facing recess in
the energy absorber;
[0012] FIG. 2 is an exploded view of FIG. 1;
[0013] FIGS. 3 and 4 are cross sections taken along lines III-III
and IV-IV in FIG. 2;
[0014] FIG. 5 is a fragmentary top schematic view of the bumper
system of FIG. 1;
[0015] FIG. 6 is an exploded perspective view of another bumper
system embodying the present invention;
[0016] FIG. 7 is a perspective view of the bumper system of FIG. 6,
a portion of the energy absorber being removed to better show
engagement of the energy absorber with the beam;
[0017] FIG. 8 is a cross section taken along line VIII-VIII in FIG.
7;
[0018] FIG. 9 is a cross section of an alternative bumper system,
the cross section being similar to FIG. 8, and FIG. 9A is a
fragmentary perspective view of an apertured version of the U-beam
shown in FIG. 9;
[0019] FIG. 10 is a perspective view of a rear bumper system
embodying the present invention; and
[0020] FIG. 11 is an exploded view of FIG. 10.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] A bumper system 20 (FIG. 1) includes a beam 21 with a
tubular center section and flattened end sections 23 and 24, and a
molded energy absorber 22 adapted to nestingly receive the beam 21
to form a unitary subassembly that can be handled and assembled as
a unit to a vehicle. The flattened end sections 23 and 24 form
vertically enlarged attachment members or "hands" on each end of
the beam 21 that engage mating flat surfaces on the energy absorber
22. Mounts 26 abuttingly engage a rear of the flattened end
sections 23 and 24, and fasteners 27 extend through the energy
absorber 22 and the flattened end sections 23 and 24 to secure the
tubular beam 21 and energy absorber 22 to the mounts 26. It is
contemplated that the term "mount" as used herein includes a rail
extending from a vehicle frame, or similar structural frame
component.
[0022] The beam 21 (FIG. 1) is described in sufficient detail below
for an understanding of the present invention by persons skilled in
this art. Nonetheless, if additional discussion is desired, the
reader's attention is directed to application Ser. No. 09/822,658,
filed Nov. 1, 2001, entitled METHOD OF FORMING A ONE-PIECE TUBULAR
BEAM, and application Ser. No. 09/904,066, filed Mar. 30, 2002,
entitled ROLLFORMED AND STAMPED DOOR BEAM, and also U.S. Pat. No.
5,092,512, issued Mar. 3, 1992, entitled METHOD OF ROLLFORMING AN
AUTOMOTIVE BUMPER, the entire contents of all of which are
incorporated herein in their entireties. Different vehicle mounts
can be used with the present invention. The mounts illustrated in
FIG. 14 are described in sufficient detail below for an
understanding by persons skilled in the art. Nonetheless, if
additional discussion is desired, the reader's attention is
directed to application Ser. No. 09/964,914, filed Sep. 27, 2001,
entitled BUMPER CRUSH TOWER WITH RINGS OF VARIED STRENGTH, the
entire contents of which is incorporated herein in its
entirety.
[0023] Beam 21 (FIG. 2) includes a tubular center section 28 having
a square cross section defined by front, rear, top, and bottom
walls. The beam 21 is rollformed to a desired tubular shape, welded
along a weld bead 29 located at a middle of the rear wall, and then
swept into a curvilinear shape that matches a front end (or rear
end) of a selected model vehicle. It is noted that different cross
sections can be used, if desired. The weld bead 29 stops short of
an end of the beam 21, and about 6 to 8 inches of an end of the
walls are reformed and "opened up" to a relatively coplanar flat
condition to form the flattened end sections 23 and 24. A pattern
of holes 30 are formed in the flattened end sections 23 and 24,
which correspond to attachment holes in the mount 26.
[0024] Energy absorber 22 (FIG. 2) includes an injection-molded
member 32 made from a suitable non-foam polymeric material having
good properties for absorbing energy upon impact, such as Xenoy
material. The non-foam material substantially forms the structure
of energy absorber 22, including box-shaped sections 33, which are
molded along rail 34 at strategic locations for improved impact
properties, as described below. The box-shaped sections 33 include
vertical sidewalls 33' and top and bottom walls 33" that combine
with front wall 39' to form a hollow internal cavity.
[0025] The center section 28 includes horizontal upper and lower
rails 34 and 35, both of which have rearwardly-facing U-shaped
cross sections. The upper rail 34 defines a large portion of the
rearwardly-facing recess 25 (FIG. 4), which is shaped to closely
receive the center tubular section of the beam 21. The box-shaped
sections 33 are molded onto top, front and bottom surfaces of the
upper rail 34 at strategic locations along its length. Two such
sections 33 are shown, but more or less can be used. The sections
33 provide improved energy absorbing characteristics to the bumper
system 20, and further the sections 33 have an upper surface shaped
to support the vehicle front fascia 36, which is typically a low
stiffness or TPO material that requires support against the forces
of gravity.
[0026] The energy absorber 22 (FIG. 2) also includes mounting
sections 38 that form integrated crush boxes over the mounts 26 at
each end of the center section 28. The mounting sections 38 (FIG.
3) each include a rectangular ring-shaped planar outer front wall
39, rearwardly-extending walls 40 forming an open "C" shape that
extends rearwardly from the front wall 39, a rectangular
ring-shaped planar rear wall 41 that extends from the
rearwardly-extending walls 40, forwardly-extending walls 42 that
form a square tube shape that extends forwardly from the rear wall
41, a rectangular ring-shaped planar inner front wall 43 that
extends from the forwardly-extending walls 42, and an interior
stiffener flange 44 that extends rearwardly from the inner front
wall 43. Additional stiffening webs can be extended between the
rearwardly-extending walls 40 and the forwardly-extending walls 42
as needed for stiffness and structure in the energy absorber 22. A
plurality of legs 35' extend below the lower rail 35, such as for
supporting a bottom of the TPO fascia on a front of the
vehicle.
[0027] The flattened end section 23 (and 24) (FIG. 3) includes a
flat front surface that mateably engages the flat rear surface of
the planar rear wall 41. The mount 26 includes a tubular section 47
(e.g. a crush tower for optimal energy absorption in front impact),
a rear plate 48 shaped for connection to a vehicle, such as to
vehicle frame members, and a front plate 49 shaped to mateably
engage a flat rear surface on the end section 23 (and 24).
Fasteners, such as bolts 50 are extended through aligned holes in
the planar rear wall 41, in the flattened end sections 23 (and 24),
and the front plate 49. Notably, the tubular portion of beam 21
(i.e. center section 28) extends short of the mounts 26 (see FIG.
5), and further the flattened end sections 23 (and 24) extend only
to the outer edges of the mounts 26, for reasons discussed
below.
[0028] The energy absorber 22 includes corner sections 52 (FIGS. 2
and 5) having an apertured front wall 53, an apertured rear wall
54, and reinforcing walls 55 that extend between the front and rear
walls 52 and 53 for structural support. The front wall 53 curves
rearwardly at its outer edge to form an aerodynamic shape at a
front of the vehicle fenders. Further, the reinforcing walls 55
include a top wall 56 shaped to support portions of an RRIM fascia
in the area of a vehicle front fender. Also, the corner section 52
includes a tubular canister portion 57 and canister-mounting
structure 58 for adjustably securely supporting a fog lamp assembly
59 (and/or a turn signal assembly).
[0029] As shown in FIG. 5, the corner section(s) 52 include a
rearwardly-extending box section 60 that is outboard of the mount
26 and positioned adjacent an end of the flattened end sections 23
(and 24). During a corner impact by an object 61, forces are
transmitted along lines 62 and 63 into the corner section 52. The
angled forces 63 are directed through the box section 60 at an
angle toward a side surface of the mount 26. The angled forces
cause the corner section 52 to bend rearwardly in direction 64,
sliding rearwardly slightly along line 64' on the mount 26
(depending on the magnitude of the forces 63). This action tends to
allow the angled forces to relieve themselves, and also tends to
cause the object 61 to bounce sideways off the vehicle bumper
system 20.
[0030] When an object 66 is struck in a front impact directly
in-line with the mounts 26, the forces 67 are transmitted directly
against the mount 26 in a manner permitting the mount 26 to absorb
forces in a telescoping manner like it historically is designed.
(I.e. the forces are linear and permit the tubular section 47 to
telescopingly crush and collapse in a predictable manner.) When the
bumper system 20 is struck in a center area between the mounts 26,
the impact is primarily transmitted linearly into the mounts 26,
due to the strength of the beam 22. Nonetheless, it is noted that
with the present beam 22, some bending may occur, depending on a
width of the impact area on the bumper system 20 and how nearly it
is perfectly centered on the bumper system 20.
[0031] In the modified bumper system 20A (FIGS. 6-8), a beam 21A
similar to beam 21 is provided, and a "longer stroke" energy
absorber 22A is attached to its face. The energy absorber 22A
includes upper and lower U-shaped rails 34A and 35A that open
rearwardly. The rails 34A and 35A are connected by vertical webs
65A that extend fore/aft, and by a rear wall 66A that extends
across a back of the energy absorber 22A. Flanges 67A and 68A
extend rearwardly from the rear wall 66A. The flanges 67A and 68A
engage and cover top and bottom walls of the beam 21A, and include
fingers 67A and 68A' for snap-locking onto the beam 21A for
temporary securement of the energy absorber 22A to the beam 21A. In
energy absorber 22A, the corner sections 52A also form the mounting
section of the energy absorber 22A. Specifically, the corner
sections 52A include a flat rear wall 70A, and perpendicular walls
71A forming a box around the flat rear wall 70A. The end section
23A (and 24A) of the beam 21A engage a rear surface of the flat
rear wall 70A, and fasteners (i.e. bolts) are extended through
aligned holes in the flat rear wall 70A, the flattened sections 23A
(and 24A), and the front plate of the mount (26) to which it is
attached.
[0032] A rear "root" portion 72A of the inner wall of the rails 34A
and 35A is offset slightly from the flanges 67A and 68A (FIG. 8),
and also is offset from the corresponding top and bottom walls of
the beam 21A. Upon front impact, the rails 34A and 35A are driven
rearwardly. Due to the stiffness of the beam 21A, this causes the
"root" portion 72A of the energy absorber 22A to buckle and fold
onto itself and onto the flanges 67A and 68A, as shown by arrows
73A. The result is a much more predictable and "softer" impact. At
such time as the energy absorber 22A is completely crushed, forces
from the impact are directly transmitted to the beam 21A, providing
a force versus deflection force curve increases sharply over the
initial force versus deflection curve.
[0033] The bumper system 20B (FIG. 9) is not unlike the bumper
system 20A (FIGS. 6-7), but in system 20B the beam 21B is U-shaped
(i.e. is not tubular), and further it is insert-molded into a
center of the energy absorber 22B. In the bumper system 20B, the
beam 21B includes a plurality of apertures or holes to allow the
plastic material of the energy absorber to flow through and
interlock with the metal beam 21B, thus providing better bonding
and preventing de-lamination. It is noted that the apertures 75B
may reduce a bending strength of the beam 21B, depending on their
location. The illustrated apertures 75B are located only on the
vertical flange 76B of the beam 21B, such that they do not greatly
affect bending strength in a direction parallel an impact force.
Nonetheless, the location and shape of the apertures 75B can be a
desirable thing by helping distribute and relieve stress in some
specific vehicle applications.
[0034] It is noted that a strength of the tubular portion of the
beam 21B (or beams 21A or 21) can be substantially increased by
press-fitting within the tubular portion an internal energy
absorber, such as is illustrated in FIGS. 14-15. The internal
energy absorber tends to reduce a tendency of the beam to
prematurely kink or bend, resulting in a consistently higher and
more predictable energy of absorption during impact.
[0035] It is to be understood that variations and modifications can
be made on the aforementioned structure without departing from the
concepts of the present invention, and further it is to be
understood that such concepts are intended to be covered by the
following claims unless these claims by their language expressly
state otherwise.
* * * * *