Energy absorbing vehicle pillar structure

Abstract: An improved structure is provided for supporting pillars of automotive vehicles which provides energy absorption through provision of a pair of energy absorbing chambers (52,50) defined by an interior trim pillar (28) and interior (26) and exterior (24) panels forming the "A" pillar of a vehicle (10), respectively. Energy absorbing media (30), such as springs (76,78,86), elongated tubes (84) and viscous fluids are taught for use as energy absorbers.

Description: The present invention relates generally to automotive vehicle body structure, and more particularly to the construction of automotive vehicle pillars to accommodate energy absorption. In the design of modern automotive vehicles, it is has been a goal to provide body structures which manage the absorption of energy in response to the imposition of frontal loads. More recent design activity in the vehicle body arts has been directed to the management of energy imposed on the vehicle occupant compartment in response to loads imposed on the sides of the vehicle and to loading imposed within the vehicle occupant compartment. While the cushioning of surfaces facing the vehicle occupant compartment has long been practised in the automotive industry, the basic, usually metal, structure of the body itself has been accommodated rather than made an integral part of the energy management design, although early designs, such as that exemplified in U.S. Patent 5,163,730 to Welch, indicate the general principle of cushioning such structure is known. This cushioning, however, is disadvantageously limited to localised positions on the pillar , which may not provide optimal energy management in all applications. More recently commonly assigned USSN 08/225,689, published as EP-A-676315, disclosed a more comprehensive cushioning approach in certain pillar embodiments in which cushioning media are carried within the pillar. Accommodating such structure within a pillar is not, in all cases, possible or desirable. It is an object of the present invention to provide an energy absorbing pillar structure which enhances the capability of the pillar to absorb energy in response to loads laterally imposed with respect to the vehicle. DE-A-1780386 discloses a pillar structure for an automotive vehicle including an interior panel, an exterior panel and a trim pillar defining spaces therebetween and a viscous fluid carried in one of the spaces. According to the present invention there is provided an energy absorbing pillar structure for an automotive vehicle, comprising: an exterior panel arranged in generally vertical orientation to define an outwardly concave exterior surface of the vehicle; an interior panel arranged in longitudinal registration with the exterior panel and defining an interior surface convex with respect to the exterior panel exterior surface and defining an energy absorbing chamber with the exterior panel; an interior trim pillar fixedly secured to in complementary relationship with substantially all of interior panel interior surface and defining another energy absorbing chamber thereinwith the exterior panel; means defining peripheral flange portions for joining the exterior and interior panels together; and energy absorbing media carried laterally within the other energy absorbing chamber; characterized in that the energy absorbing media includes a plurality of tubes carried within the other chamber and extending generally parallel to the vertical axis of the pillar. The invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a partial side view of an automotive vehicle; Figure 2 is a cross section taken along line 2-2 of Figure 1; Figure 3 is a cross-sectional view similar to Figure 2 illustrating an embodiment which is not a part of the present invention and is described herein for better understanding of the present invention; Figure 4 is a cross-sectional view similar to Figure 3 illustrating an embodiment of the present invention; and Figure 5 is a cross-sectional view similar to Figure 3 illustrating an embodiment which is not a part of the present invention and is described herein for better understanding of the present invention. Turning now to the drawings, in particular to Figure 1 thereof, an automobile 10 is illustrated as having a body 12 having a lower portion such as indicated at the door 14, a roof portion 16, and pillars 18, 20. As is conventional, the pillars 18, 20 provide support for the roof 16 in closing the vehicle occupant compartment indicated generally at 22. The pillars 18, 20 are constructed to enhance energy absorption in response to loads imposed laterally of the pillars. As used herein, it is to be understood that the pillars 18, 20 extend generally vertically between the lower portion 14 of the vehicle 10 and the roof 16, and that loads imposed generally normal to this vertical extent are referred to as lateral or side loads. The pillars 18, 20 are preferably fabricated as metal stampings and are configured to enhance energy absorption both by the shape and arrangement of the metal stampings and by co-operation with interior trim structure to define an overall energy absorbing pillar structure. Turning now to Figure 2, an embodiment for the front or A-pillar 20 is illustrated as including an exterior panel 24, an interior panel 26, an interior trim pillar 28, and energy absorbing media 30 disposed within the trim pillar 28. The exterior panel 24, which is illustrated in Figure 2, defines an outwardly concave external surface 32. First and second peripheral flange portions 34, 36 bound an outwardly concave section 38 to define a truss-like structure adjacent the door 14. Known seal assemblies, generally denoted by the letter S are conventionally carried for sealing engagement between the panel 24 and the door 14; and the vehicle windshield W is mounted against the flange 34. The interior panel 26 likewise includes first and second peripheral flanges portions 40, 42 positioned in facing relationship with respect to the flange portions 34, 36 of the exterior panel 24. A concave inward truss portion 44 having a profiled laterally inwardly facing surface 46 extends between the flange portions 40, 42. The interior trim pillar 28 is carried interiorly of the interior panel 26 in complementary relationship with the surface 46 thereof. As shown in Figure 2 the trim pillar 28 is of L-shaped cross section and includes external surfaces 48 abutting the facing surfaces 46 of the interior panel 26. The trim pillar 28 is illustrated as being fabricated from a relatively soft plastic or rubber material and is formed in a closed section to define an energy absorbing chamber 50 for containing the energy absorbing media 30. To co-operate in the response of the pillar 20 to the imposition of lateral loads it is necessary to fixedly secure the trim pillar 28 in the position shown. This may be accomplished by conventional fastening means such as acrylic foam tape, urethane adhesive, rivets, clips and other mechanical fasteners, illustration of which is not needed for those skilled in the automotive body arts. With the panels 24, 26, and the trim pillar 28 so arranged, a first energy absorbing chamber 52 is defined between the exterior panel 24 and the interior panel 28, and a second energy absorbing chamber 50 is defined within the interior trim pillar 28. Turning next to Figure 3, in this embodiment, which is not a part of the present invention, the configuration for the pillar 20 is essentially identical to that in Figure 2 save the provision of an energy absorbing medium 330, preferably defined as a generally C-shaped, outward opening, resilient spring assembly 74. Two springs 76, 78 are interleaved to be grounded against the inner panel 326. The spring 76 has an out-turned flange 80 that is secured to the flange 340 of the interior panel 326, and the spring 78 has an out-turned flange 82 secured to the flange 342 of the interior panel 326. Turning next to Figure 4, the configuration in the embodiment of the present invention for the pillar 20 is essentially identical to that in Figure 2 save the provision of an alternative energy absorbing medium 430, defined as a plurality of crushable tubes 84 extending generally parallel to the longitudinal axis of the pillar 20. It is contemplated that aluminium or rubber may be used in constructing the tubes, energy absorbing requirements of a particular vehicle application dictating the choice. In some applications it may be possible to eliminate the walls of the trim pillar 430 and gang the tubes 84 together in complementary conformance with the surface 446 of the interior panel 426 in fixed relationship, as through the use of adhesives. Turning lastly to Figure 5 which is not a part of the present invention, yet another energy absorbing medium is indicated at 532, differing from the medium 432 illustrated in Figure 3 in that a spring member 86, preferably of metallic construction, is received in snap-in relationship at one end in a clip assembly 88 or other device adjacent the flange of interior panel 526 and is adhesively secured at its other end, as indicated at 90, to the flange. This embodiment offers the capability of tailoring energy management response to loading in a variable fashion. Depending upon the direction in which loading is imposed (left or right as viewed in Figure 5) the attachment of the spring 86 to the interior panel 526 will fail at 88 or 90 without failure at the other, changing the resistance of the overall trim pillar 528 to deformation. In the embodiment shown in Figure 4, the energy absorbing capability of the structural pillars of the automotive vehicle 10 is improved over the prior art through the provision of an interior trim pillar that carries an energy absorbing medium and is fixedly secured to the body structure in a complementary fashion. This improved structure may, in some situations permit economies in the design of the structural pillars because of the added function provided by the improved trim pillars.

Claims: An energy absorbing pillar structure for an automotive vehicle, comprising: an exterior panel (24,424) arranged in generally vertical orientation to define an outwardly concave exterior surface (32) of the vehicle; an interior panel (26,426) arranged in longitudinal registration with the exterior panel (24) and defining an interior surface convex with respect to the exterior panel exterior surface (32) and defining an energy absorbing chamber (52) with the exterior panel; an interior trim pillar (28) fixedly secured to in complementary relationship with substantially all of interior panel interior surface and defining another energy absorbing chamber (50) thereinwith the exterior panel; means defining peripheral flange portions (34,36,40,42) for joining the exterior and interior panels together; and energy absorbing media (330,430,530) carried laterally within the other energy absorbing chamber (50); characterized in that the energy absorbing media includes a plurality of tubes (84) carried within the other chamber (50) and extending generally parallel to the vertical axis of the pillar. An energy absorbing pillar structure as claimed in claim 1, wherein the interior trim pillar (28) is adhesively secured to the interior panel. An energy absorbing pillar structure as claimed in claim 1 or 2, wherein the tubes (84) are fabricated from aluminium or rubber.

Inventors: CHIREHDAST MEHRAN, SHAHAB SYED A, CHIREHDAST, MEHRAN, SHAHAB, SYED A.
Applicants: FORD FRANCE, FORD MOTOR CO, FORD WERKE AG, FORD FRANCE S.A., FORD MOTOR COMPANY LIMITED, FORD-WERKE AKTIENGESELLSCHAFT
Application year: 1995
Main classification: B62D25
IPC codes: B60R21, B62D25, B60R13