The Energy Management Structure for the Volkswagen ESV

In order to improve the crashworthiness of vehicles, attention must be given both to an improvement of the occupant crash protection and to a reduction in the “aggressiveness” of heavy vehicles toward lighter vehicles. The latter requires a “soft nose” on the heavier vehicle. By use of hydraulic shock absorbers in the bumper system, an energy-absorption distribution can be achieved in vehicle-to-vehicle collisions without requiring larger deformations on the large vehicle than on the smaller vehicle.

A theoretical investigation has been conducted concerning which type of hydraulic absorbers can best achieve the ideal weight-dependent layout of the frontal structure. A hydraulic absorber with a stroke-controlled throttle outlet area appears to be a suitable type. With this system, energy distribution in frontal impacts is attained and most of the energy is absorbed in the frontal structure of the impacting vehicle in rear and side collisions.

The proposal for energy distribution and absorption achieved by weight and velocity dependent frontal crash behavior is tested and confirmed by means of experimental investigations within the scope of the Volkswagen experimental safety vehicle project.