During the Seventies the market demand showed a
need for higher product differentiation, so
the Auto Indutries were forced to develop several different
platforms.
The 1973 energy crisis changed the perspective
of car makers.
The Federal Corporate Average Fuel Economy (CAFE)
standard was enacted in 1975: it required auto makers to meet
certain mileage standards across their
entire
fleet of vehicles.
In order to meet these standards, between 1976 and 1982 the
average content of steel per vehicle was lowered from 1035 Kg
to 795 Kg. This was made possible by reducing the vehicle size
and switching from the body-on-frame to the unibody layout.
|
|
Renault R16 (1970) - Unibody exploded view (Source: "Style
Auto" N.6, Edizioni Style Auto, Torino, Italy,
1965)
|
|
In addition to this, Auto Industries started new researches investigating the
use of light materials.
In 1979 Ford created a prototype based on the LTD sedan, entirely
made of carbon fiber composites: this enabled to obtain a primary
and secondary weight reduction respectively equal to 315 Kg and
215 Kg.
Fiat VSS (1978) - Veicolo
Sperimentale a Sottosistemi(SubSystems
Experimental Vehicle)
The Fiat VSS prototype (see Figure) was based on the
Fiat Ritmo, and was the result of the collaboration between
Fiat, the I.D.E.A. Institute and Renzo Piano's team.
The structure was a steel spaceframe and
the body (with plastic panels) had no load-bearing capacity,
but for the first time this choice was made in order
to reduce the vehicle weight and to obtain a high
flexibility in terms of external shape, production
and assembly.
After twenty years these issues became of primary importance
for the whole Automobile Industry.
In the original concept the 9 external panels had to
be produced separately (as complete "subsystems")
and then assembled in a final production line.
Today this philosophy of production is being investigated
by many Car Manufacturers.
|
|
|
Fiat
VSS (1978)
|
 |
Space
Frame structure
|
|
|
|
