It is generally known that it is advantageous to configure a motor vehicle such that a forward section of the vehicle will be predisposed to deform in a predetermined manner during a frontal collision, to thereby provide protection to occupants of the vehicle. Various governmental and industry organizations, such as the National Highway Safety and Transportation Authority (NHTSA) and the Insurance Institute for Highway Safety (IIHS) have promulgated standardized testing procedures, standards, and rating systems relating to the performance of vehicles during frontal collisions.
There are several aspects to providing acceptable protection of the occupants. It is desirable to cause the components of the forward part of the vehicle to deform in such a way that they do not penetrate the passenger compartment of the vehicle. It is also desirable to cause the components to deform in such a way that the change in momentum of the vehicle, caused by the frontal collision, is absorbed into the front frame structure during the collision over period of time that is long enough for supplemental restraint systems, such as air bags, to be deployed, and so that G-loads on occupants of the vehicle can be held within acceptable limits.
In order to achieve these objectives, in prior art vehicles, the forward end of the vehicle would be compressed 22–27 inches in a time period of about six hundredths (0.06) of a second. The amount and duration of compression that can be accomplished for a given vehicle are limited, of course, by the size and shape of the vehicle, and in particular by the percentage that the length of the portion of the vehicle extending forward from the passenger compartment can be compressed during the collision.
It is desirable to provide an improved front frame structure and method for absorbing energy during a frontal collision of the vehicle, that enhances occupant protection by increasing the percentage of length that the forward end of the vehicle can be compressed, and by lengthening the duration of the compression.