Patent Application
20120256445
The present disclosure generally relates to vehicle structures, and more particularly to a high strength and low weight roof support pillar for a vehicle.
It is well known that in order to improve fuel efficiency and vehicle emissions, it is desirable to produce a lightweight motor vehicle. To achieve this goal, several vehicle manufacturers have proposed vehicles in which a substantial proportion of the body structure or body shell is constructed from a lightweight material such as an aluminum alloy. An example of such a vehicle construction is shown in U.S. Pat. No. 6,099,071.
With reference to
Reinforcements between the inner and outer sheet metal structures are generally not employed. However, to the extent reinforcement members are employed, the reinforcement members for vehicle body structures are generally provided to improve the vehicle structure's performance in a side impact collision or a rear end collision.
For example, DE 3103580 A1 and U.S. Pat. No. 4,462,633 improve occupant protection in the event of a side impact collision. The vehicle body structure components are aligned with the rocker such that the rocker provides structure, stiffness and strength to protect the vehicle occupant in a side impact collision. Similarly, in EP0037587 A1, the reinforcement for the vehicle body structure components is operatively configured to protect a passenger in the event of a collision also comes in the form of partition plates at vehicle rocker.
Other support structures are shown, for example, in U.S. Pat. No. 5,267,772. U.S. Pat. No. 5,267,772 discloses a reinforcement which is formed in the quarter panel by placing a closed cross-sectional channel against the inner wall of the quarter panel. This channel extends between the rear fender panel and the quarter panel along the length of the rear body portion. The reinforcement is controlled by a crush pattern control means so that the reinforcement causes an intended pattern of deformation of the rear body portion in the event of a rear-end collision. The impact energy of a rear-end collision applied to the vehicle is absorbed during the deformation of this reinforcement.
Finally, DE19528874 A1 discloses a body structure for a motor vehicle where a reinforcement structure is also provided within a two piece hollow body structure component. However, this multi-part profile arrangement is quite complicated and run produced only with considerable manufacturing and assembly costs.
Accordingly, it is desirable to implement a low cost, robust, light weight and high strength pillar structure which can improve the roof strength of a vehicle.
A vehicle roof support pillar is disclosed according to the embodiment(s) provided herein. The vehicle roof support pillar includes a pillar inner panel, a pillar outer panel and a unitary closed-section reinforcement member. The unitary closed-section reinforcement member is disposed entirely within a chamber defined by the pillar inner panel and the pillar outer panel. The unitary closed-section reinforcement member includes an upper area and a lower area. The lower area of the unitary close-section reinforcement member has an increasing cross-section below the buckling line. The pillar inner panel includes upper and lower ends. The lower inner end has a greater width relative to the upper inner end. The pillar outer panel also has a progressively increasing width relative to the upper outer end.
The present invention will now be described by way of example, with reference to the accompanying drawings:
Referring now to the drawings wherein like reference numerals are used to identify identical components in the various views.
With reference to
The upper inner end 22 of the pillar inner panel 14 is proximate to the roof rail 24 of the vehicle. The lower inner end 20 of the pillar inner panel 14 is proximate to the rocker 26 of the vehicle. The lower inner end 20 has width that is greater than the upper inner end 22. Accordingly, as the pillar inner panel 14 extends toward the rocker 26, the width of the pillar inner panel 14 increases.
A pillar outer panel 16 is affixed to the pillar inner panel 14 via a welding process, mechanical fasteners or the like. The pillar outer panel 16 also includes an upper outer end 28 and a lower outer end 30 wherein the upper outer end 28 is proximate to the roof rail 24. The lower outer end 30 of the pillar outer panel 16 is proximate to the rocker 26. The pillar outer panel 16 also has a progressively increasing width relative to the upper outer end 28. As the pillar outer panel 16 extends toward the rocker 26, the width of the pillar outer panel 16 increases or widens as shown in
The unitary closed-section reinforcement member 18 is disposed entirely within a chamber defined by the pillar inner panel 14 and the pillar outer panel. The unitary closed-section reinforcement member 18 includes an upper area 36 and a lower area 38. The lower area 38 of the unitary closed-section reinforcement member 18 (or alternatively referenced as “reinforcement member”) is progressively increasing in cross section relative to the upper area 36 of the unitary closed-section reinforcement 18. Accordingly, as the reinforcement member 18 extends below the buckling line, the cross-sectional area of the unitary closed-section reinforcement member 18 increases.
It is also to be understood that the unitary closed-section reinforcement member 18 has a varying cross section. As shown in
The closed-section reinforcement member 18 is disposed both below and above the buckling line on the inner side of the B-Pillar 58?. The closed-section reinforcement member 18 attaches to a one-piece B-Pillar inner and to the one-piece B-pillar outer in several locations around the beltline over a length extending for several inches both below and above the buckling line 44 location. The closed-section reinforcement member 18 provides self-stability through its closed and multi-shaped cross section that attaches to the same buckling inner B-pillar. By attaching the unitary closed-section reinforcement member to the pillar inner panel, the roof strength of the vehicle is improved given that there is a higher thickness to the (buckling plate) width ratio.
This thickness to width (t/w) ratio allows for higher critical stresses thus higher buckling stresses. Thus, higher buckling stresses may be applied to the roof of a vehicle structure. Accordingly, the material use is optimized. For example, the present disclosure allows for a two-thickness level flanges (instead of three or four thickness) thereby providing a lighter weight structure. Moreover, the unitary structure of the closed section reinforcement member 18 provides improved stiffness in the roof pillar area of the vehicle without adding unnecessary weight or requiring a costly manufacturing/assembly process. Furthermore, this structural stability is achieved through connecting both the pillar inner panel 14 and the pillar outer panel in and around the buckling line 44.
Accordingly, the unitary closed-section reinforcement member 18 is operatively configured to connect the pillar inner panel 14 to the pillar outer panel 16 in the event of a roof impact to the vehicle to deter buckling in the roof support pillars 10. As shown in
Referring now to
The unitary closed-section reinforcement member 18 further comprises a front face 50 and a rear face 52. The front face 50 connects the inner face 46 to the outer face 48 at a front end 68 of each of the inner face 46 and the outer face 48. The rear face 52 connects the inner face 46 to the outer face 48 at a rear end 70 of the front face 50 and the rear face 52. In yet another non-limiting example of the unitary closed-section reinforcement member 18, the middle portions 54, 56 of the front face 50 and the rear face 52 may be affixed to each other as shown in
With reference to
The unitary closed-section reinforcement member 18′ is disposed entirely within a chamber defined by the pillar inner panel 14′ and the pillar outer panel 16′. The unitary closed-section reinforcement member 18′ has an upper end 22′ and a lower end 20′. The unitary closed-section reinforcement member 18′ has a varying cross-section between the upper end 22′ and the lower end 20′. The varying cross-section improves the vehicle stability by preventing buckling in the pillar inner panel 14 given that the reinforcement member 18′ and the pillar outer panel 16 are providing support to the pillar inner panel 14. Given the varying cross section of the unitary closed-section reinforcement member 18′, the unitary closed-section reinforcement member 18′ is stationary between the pillar inner panel 14′ and the pillar outer panel 16′, and therefore, prevents buckling in the pillar inner panel 14′ and the pillar outer panel 16′.
As indicated, the unitary closed-section reinforcement member 18′, 18 (shown in
Hydroforming allows complex shapes with concavities to be formed, which would be difficult or impossible with standard solid die stamping. Hydroformed parts can often be made with a higher stiffness to weight ratio and at a lower per unit cost than traditional stamped or stamped and welded parts. The hydroformed reinforcement member 18′, 18 may then be affixed between the pillar inner panel 14, 14′ and the pillar outer panel 16, 16′.
While the best mode for carrying out the invention 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.
