Page 562 - Automotive Engineering Powertrain Chassis System and Vehicle Body

Vehicle safety C HAPTER 17.1

Fig. 17.1-5 View from above of an impact test in which a sled, on which is mounted a dummy front end, is propelled towards the side
of the target vehicle.

example, protection systems such as occupant-friendly sled towards its target. From the point at which the
trim and side air bags, sometimes termed curtain air button is pressed to trigger the test, it is over all over
bags, only the relevant part of the structure, which, of within a tenth of a second!
course, includes the doors, seats and dummies, need be The profiled firing pin controls the flow of air to the
mounted. HyGe simulation is used also for development piston, so that its motion truly represents the impact
work associated with the ECE 11 Latches and Hinges and pulse experienced in practice. Among the factors af-
ECE 17 Seat requirements. The relevant structures to fecting the shape of the pulse required are the inertia of
be tested are mounted on the sled and propelled towards the whole vehicle and the reactions of not only its tyres
the rigid barrier to which can be fixed an appropriate but, in some instances, also the inertia and reactions of
target object. A maximum acceleration of 100g is occupants. MIRA has a stock of 70 different pins, and
obtainable, although 40g is more usual. The sled can be makes another when ever a new pulse is required. Speeds
accelerated to speeds as high as 104 km/h, although of up to 56 mph (104.6 km/h) are attainable, although
56 km/h is more commonly required (65 and 35 mph 35 mph (56.33 km/h) is more commonly demanded.
respectively).
The sled is powered by what, in effect, is a huge air
gun, Fig. 17.1-6. Air is compressed up to 2760 kN/m 2 17.1.2 Protection of occupants
2
(4000 lb/in ) into a holding cylinder. It is then suddenly
released, to flow over a specially profiled firing pin, into Manufacturers have always been more concerned with
the firing cylinder, where it forces the piston to thrust the protecting the occupants of their cars than simply

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