US 5,706,908 A · Front upper structure of automotive vehicle

Abstract

A hood structure for absorbing an impact applied to a hood (31) of an automotive vehicle at collision has: a hood outer panel (33) for closing an engine room (35); at least one impact absorb body (43) disposed under the hood outer panel, for absorbing the impact applied to the hood when deformed; and an engine (37) disposed under the impact absorb body, for stopping the deformed impact absorb body. Here, to reduce head injury criterion (HIC) effectively at a shortest possible stoke of the hood outer panel, an impact energy absorption rate of the impact absorb body and a total hollow gap formed between the hood outer panel (33) and the engine (37) are both determined in such a way that an impact energy generated at collision can be absorbed in accordance with an ideal impact energy absorption waveform Cm representative of an ideal relationship between reaction force (F) and stroke (S) of the deformed hood outer panel. The ideal impact waveform Cm can be obtained by calculation on the basis of an amount of impact energy required to be absorbed at collision and in accordance with the HIC derivation formulae (1) and (2). Since the impact absorb body is deformed at collision at a relatively moderate energy absorption rate to generate a secondary reaction force required for the ideal impact waveform Cm, the head impact characteristics can be securely improved.

Claims36

Dependent claims

A front upper structure for absorbing an impact applied to a front upper body of an automotive vehicle at collision having:

a front upper outer panel;
an impact absorbing mechanism disposed under the front upper outer panel, for absorbing the impact applied to the front upper outer panel when deformed;
and
an impact interference body disposed under the impact absorbing mechanism, for stopping the deformed impact absorbing mechanism,
wherein an impact energy absorption rate of the impact absorbing mechanism and a total hollow gap formed between the front upper outer panel and the impact interference body are both determined in such a way that an impact energy generated at collision can be absorbed in accordance with an ideal impact energy absorption waveform to reduce head injury criterion effectively at a shortest possible stroke of the front upper panel,
wherein the ideal impact energy absorption waveform is an ideal relationship between reaction force and stroke of the deformed front upper panel, and obtained by calculation on the basis of an amount of impact energy required to be absorbed at collision and in accordance with head injury criterion derivation formulae:
##EQU3## where HIC denotes a head injury criterion;
a(t) denotes acceleration at a center of gravity of a test impactor;
t.sub.1 and t.sub.2 denote any duration time (0<t.sub.1 <t.sub.2) during which the acceleration is applied;
and aiL from (t.sub.1, t.sub.2) to (max) denotes a maximum value selected from (a.sub.12.sup.2.5 (t.sub.2 -t.sub.1)).

7 more elements

A hood structure for absorbing an impact applied to a hood of an automotive vehicle at collision, having:

a hood outer panel for closing an engine room;
an impact absorbing mechanism disposed under the hood outer panel, for absorbing the impact applied to the hood when deformed;
and
an impact interference body disposed under the impact absorbing mechanism, for stopping the deformed impact absorbing mechanism,
wherein an impact energy absorption rate of the impact absorbing mechanism and a total hollow gap formed between the hood outer panel and the impact interference body are both determined in such a way that an impact energy generated at collision can be absorbed in accordance with an ideal impact energy absorption waveform to reduce head injury criterion effectively at a shortest possible stroke of the hood outer panel,
wherein the ideal impact energy absorption waveform is an ideal relationship between reaction force and stroke of the deformed hood outer panel, and obtained by calculation on the basis of an amount of impact energy required to be absorbed at collision and in accordance with two head injury criterion derivation formulae;
and the impact absorbing mechanism is deformed at collision at an energy absorption rate smaller than that of the hood outer panel, in order to generate a secondary reaction force required for the ideal impact energy absorption waveform.

4 more elements

A hood structure for absorbing an impact applied to a hood of an automotive vehicle at collision, having:

a hood outer panel for closing an engine room;
an impact absorbing mechanism disposed under the hood outer panel, for absorbing the impact applied to the hood when deformed;
and
an impact interference body disposed under the impact absorbing mechanism, for stopping the deformed impact absorbing mechanism,
wherein an impact energy absorption rate of the impact absorbing mechanism and a total hollow gap formed between the hood outer panel and the impact interference body are both determined in such a way that an impact energy generated at collision can be absorbed in accordance with an ideal impact energy absorption waveform to reduce head injury criterion effectively at a shortest possible stroke of the hood outer panel, and
wherein the impact interference body is a pair of strut towers provided on both sides of an engine room, and the impact absorbing mechanism is an over-strut hood inner panel and a plurality of impact absorbing members disposed between the hood outer panel and the over-strut hood inner panel.

3 more elements

A hood structure for absorbing an impact applied to a hood of an automotive vehicle at collision, having:

a hood outer panel for closing an engine room;
an impact absorbing mechanism disposed under the hood outer panel, for absorbing the impact applied to the hood when deformed;
and
an impact interference body disposed under the impact absorbing mechanism, for stopping the deformed impact absorbing mechanism,
wherein an impact energy absorption rate of the impact absorbing mechanism and a total hollow gap formed between the hood outer panel and the impact interference body are both determined in such a way that an impact energy generated at collision can be absorbed in accordance with an ideal impact energy absorption waveform to reduce head injury criterion effectively at a shortest possible stroke of the hood outer panel,
wherein the ideal impact energy absorption waveform is an ideal relationship between reaction force and stroke of the deformed hood outer panel, and obtained by calculation on the basis of an amount of impact energy required to be absorbed at collision and in accordance with two head injury criterion derivation formulae;
and the impact absorbing mechanism is deformed at collision at an energy absorption rate smaller than that of the hood outer panel, in order to generate a secondary reaction force required for the ideal impact energy absorption waveform, and
wherein the impact interference body is an engine, and the impact absorbing mechanism includes an inner panel formed with a long channel-shaped inner rib having an outer flange portion and two short channel-shaped inner ribs each having an outer flange portion and intersecting the long channel-shaped inner rib and bonded to the hood outer panel at the surfaces of the flange portions of the ribs so as to cover the engine, each intersecting portion of the long and short channel-shaped ribs being connected through a curved portion on both sides thereof, respectively.

5 more elements

Dependencies are inferred from the claim text.

Front upper structure of automotive vehicle

Life of this patent

Front upper structure of automotive vehicle

Life of this patent

Abstract

Claims36