Box member for a vehicle

Land vehicles: bodies and tops – Bodies – Body shell

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C296S205000, C296S182100

Reexamination Certificate

active

06367868

ABSTRACT:

TECHNICAL FIELD
The present invention relates to a beam in a vehicle comprising a box-shaped member made of bent sheet metal and having a greater length than both width and height. The box-shaped member also has a portion oriented in the longitudinal direction of the vehicle and that has, at a distance from one end, an area made so that the stiffness of the beam in the longitudinal direction is suddenly reduced after the beam has been deformed a pre-determined distance beginning from said end.
BACKGROUND OF THE INVENTION
Box beams appear in a number of different applications in automobiles. As an example, such beams are utilized as front lateral members in passenger car chassis and are thus components, the design of which crucially affects the collision safety of the automobile. One method of achieving high collision safety through crash control is to force, as much as possible, the elements in the structure to be deformed in the most energy-absorbing manner, which is progressive crushing or fold formation. Less energy-absorbing modes, such as rigid body rotation or bending, should thus be avoided.
From the point of view of crash safety, the ideal situation would be to allow the volume represented by the forward portion of the car to consist of a large number of cells, each having a large energy-absorbing capacity regardless of from which direction the car is struck. Such solutions, however, have not been able to be employed in mass production for a number of reasons.
Test vehicles have been manufactured in which foam plastic-filled box beams have been used to achieve controlled deformation. Such vehicles have, however, never been produced in large volumes. The reasons are many, but the most important are the high costs connected with complicated manufacturing processes and the effect on the environment of harmful chemicals in the foam used.
Normally, the beam member system in a vehicle is regarded as a passive security system where it is primarily the geometric shape of the box beams which, through their energy-absorbing capacity, determine the collision safety. It is, however, known to arrange in a vehicle an “active” beam system; that is, a system where a collision triggers an activity which makes the beam system act in a certain manner beyond its normal mechanical limitations. Such an active beam system is shown, for example, in U.S. Pat. No. 4,050,537. In the '537 patent, an explosive charge is used in the event of a collision to change a cross section of a box beam in such a manner that the beam's stiffness, and thus its energy-absorbing capacity, increases.
In view of the above described deficiencies associated with known box beam designs for vehicles, the present invention has been developed. These enhancements and benefits are described in greater detail hereinbelow with respect to several alternative embodiments of the present invention.
DISCLOSURE OF THE INVENTION
The present invention in its several disclosed embodiments alleviates the drawbacks described above with respect to conventionally designed vehicular box beams and incorporates several additionally beneficial features.
The purpose of the present invention is, in general, to achieve a simple and inexpensive active beam arrangement of the type described by way of introduction which avoids less energy-absorbing modes such as rigid rotation and bending.
This is achieved, according to the invention, by virtue of the fact that the box-shaped member is stiffened in relevant areas by means of stiffeners fixed to the box profile. The stiffeners are arranged to split off when the beam has been deformed a predetermined distance. The stiffeners can be simple plates which are glued to the beam with an adhesive which provides a hard and brittle glue joint; for example, an epoxy glue. If the areas under the plates are, for example, stamped, folded, perforated or of smaller thickness than the rest of the beam plate, a substantial reduction in the stiffness of the beam can be obtained in these areas when the glue joint breaks and the plates are shed.
A beam, arranged according to the invention, is thus considered an active beam. By studying the deformation of a passive beam after a collision, it is possible to determine where the transition occurred between upsetting or fold formation, and buckling of the entire beam. By actively softening the beam in this failure area, buckling can be avoided during deformation. As a result of the softening, the area in which fold formation occurs is extended also across the softened area up to the area behind it, which can be stiffer.
The beneficial effects described above apply generally to the exemplary systems and methods for improving box beam performance. The specifics through which these benefits are enabled will be described in detail hereinbelow.


REFERENCES:
patent: 4050537 (1977-09-01), Bez
patent: 4194763 (1980-03-01), Reidelbach et al.
patent: 5314229 (1994-05-01), Matuzawa et al.
patent: 5951097 (1999-09-01), Esposito et al.
patent: 2459518 (1976-07-01), None
patent: 3826958 (1989-03-01), None
patent: 0278912 (1988-08-01), None
patent: 0015017 (1977-02-01), None
patent: 0017221 (1979-02-01), None
patent: 0124974 (1984-07-01), None

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Box member for a vehicle does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Box member for a vehicle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Box member for a vehicle will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2818436

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.