FIELD OF INVENTION
This invention is directed to pedestrian protection hood particularly a
deformable hood inner panel of vehicle for improved energy absorption during
pedestrian head impact. This hood inner panel increases pedestrian safety
during collision between pedestrian and motor vehicle.
BACKGROUND/ PRIOR ART
Hood of vehicle includes hood inner panel (1) which is joined with hood outer
panel (2) being hemmed at one end and sealed by mastic sealant (S) at the
other end as shown in fig 1. The hood inner panel forms a cup structure., one I
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inclined side wall (3) of which is bent to adjoin with hood outer panel (2) for
hemming at one end and at lower end, the side wall (3) joins resting surface of
hood seal rear (5) as illustrated in fig 1.
The inclined side surface (3) increases rigidity. Here, there is one point of
bending (T) and the inner panel (4) adjoined with the .outer panel only takes
part in deformation..
Therefore it undergoes less deformation under pedestrian head impact in case
of collision with vehicle. This leads to increase in head injury criteria (HIC)
value.
In this regard reference may be made to US patent No. US2015/0054305 A1
providing hood inner panel, which includes two regions separated by an angled
wall or a reinforcing structure that increases local rigidity. The rigidity of the
hood inner panel in the vicinity of the angled wall is devised for energy
absorption by the provision of a .plurality of apertures which can increase the
deformability of the hood inner panel.
In the above, energy absorption takes placetthrough the slots and apertures
located on the angular wall. For making slots and apertures additional tool and
operation is required.
In 2ase such kind of slots are provided in rear side of hood inner near
windshield, it would cause controlled deformation of hood at the time of head
impact but the hot air would leak from slots and hood seal' rear would not be
able to stop the hot air leakage from engine room to the cabin side, thereby . ,
affecting the air-conditioning performance of vehicle.
Hence, hood inner needs to be designed in such a manner that, it causes
controlled deformation as well as prevents hot, air leakage from engine room to
cabin.
None of the above can fulfill the requirements of the present invention. Hence
the present invention has been introduced to make'the hood inner panel
deformable, which can efficiently serve the purpose.
OBJECTS OF THE INVENTION
An object of this invention is to propose a pedestrian protection hood for
improved energy absorption during pedestrian head impact.
Another object of this invention is to propose a pedestrian protection hood for
improved energy absorption during pedestrian head impact which obviates
shortcomings of known art, (s).
Further object of this invention is to propose a pedestrian protection hood for
improved energy absorption during pedestrian head impactwhich meets the
head injury criteria value.
SUMMARY OF INVENTION
, According .to this invention there is provided a pedestrian protection hood for
improved energy absorption during pedestrian head impact comprising a .hood
outer panel joined with a hood inner panel being hemmed at one end and
sealed at other end, wherein the inner panel constitutes a cup structure
including a base between two side walls, in which the side wall inclined
towards the hemming area is having an intermediate bending point to form
deformable hood inner panel.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from
the ensuing description when read in conjunction with the accompanying
drawings of exemplary embodiments of invention and wherein:
Fig. 1 shows: Conventional front hood inner panel and sectiona1,view thereof.
Fig. 2 shows: Front hood inner panel according to present invention.
Fig. 3 shows:. Enlarged view of modified.'inclined wall of hood inner panel in
accordance with present invention.
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Fig; 4 shows: Installation of novel hood inner panel in the hood of vehicle.
Fig. 5 and 6 shows: Deformirig pattern.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS
The instant invention makes- a disclosure in respect of pedestrian protection
hood of vehicle for improved energy absorption during pedestrian head impact.
A novel hood inner panel of vehicle.,is introduced for better energy absorption.
during a pedestrian head impact on hood comp.
Now, the deformable hood inner panel of vehicle will .be described with
reference to fig' 2 hereinunder.
The inclined side wall (3) of the, hood inner panel directing towards the
hemming area undergoes deviation from its alignment at an intermediate point
(P) in.proximity to the hemming area so as to form another inclined wall. Thus
the side wall (3) ,of prior art is transformed into two inclined side walls (3A,3B)
adjoined with each other at the intermediate point (P) as bestseen in fig. 3.
The intermediate point (P) constitutes bending point. Thus, this inclined wall
(3B) gives rise another bending point (P) in addition to a bending point (P').
Now.fig 4 can be referred to illustrating hood of vehicle implementing said novel
inner panel.
Thus, the invention increases the deformability of front hood inner panel
during the head impact by reducing the rigidity of inclined wall of hood inner
panel. This eventually decreases the HIC vzlue of pedestrian head impact. The
additional surface (3B) changes the deformation pattern and acts as a bending
initiation point. At the time of pedestrian head impact on the top surface of
hood, hood inner first bends down from the junction point (P). This junction
point acts as a hinge point at which the rotation of said wall occurs thereby
assisting in absorption of impact energy. This bending gives required amount
of deformability to the front hood inner panel for the absorption of impact
energy which reduces the HIC value.
The designed shape of the inclined wall (3A, 3B) generates two bending points
(P', P). So that, the newly added inclined surface (3B) as well as the part of
inner panel (4) adjoined with the outer panel participate in deformation during
head impact on hood.
PPQ BELHI 83-10-2015 17 154
I - Now referring to fig 5 and 6 in respect of 'deforming pattern, in. which the
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figures indicate deformation of existing hood inner panel (HI) and hood inner
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panel of present invention (Hz).From fig 5, it can be observed that additional
inclined surface (3B) in the hood inner panel helps to augment the controlled
deformation of hood' inner panel at highlighted 1ocation.From fig 6 it can be
observed that the newly added tapered wall (3B) weakens the hood inner in the .
indicated region which results in bringing down the head injury'criteria value
at various'locations on the hood throughout the vehicle width.
Advantageous Features:
- Meets the head injury criteria value during head impact of pedestrian.
- Reduction in the contact surface between the hood inner and outer
panel, which inturn reduces the chances of rusting unlike prior art
, - No addition to cost and assembly time.
I t is 'to be noted that the present invention is susceptible to modifications,
adaptations and changes by those skilled in the art. Such variant embodiments
employing the concepts and features of this invention are intended to be within
the scope 'of the present invention, which is further set forth under the
following claims:-

WE CLAIM:
1. A pedestrian protection hood for improved energy absorption during
pedestrian head impact comprising a hood outer panel joined with a
hood inner panel being hemmed at one end and sealed at other end,
wherein the inner panel constitutes a cup structure incl~iding a base
between two side walls, in which the side wall' inclined towards the
hemming area is having an intermediate bending point to form
deformable hood inner panel.
2. A pedestrian protection hood for improved. energy absorption during
pedestrian head impact as claimed in claim 1 wherein the inclined side
wall of the inner panel directing towards the hemining area undergoes
deviation from its alignment at the intermediate point in proximity to the j
hemming area to form another inclined wall.
3. A pedestrian protection hood for improved energy absorption during
pedestrian head impact as claimed in claim. 1 or 2wherein the
' intermediate point forms a bending initiation point which acts as a hinge
point for rotation of said side wall for absorption of impact energy 'to I
reduce the head injury criteria value.
4. A pedestrian protection hood for improved energy absorption during
pedestrian head impact as claimed in any of the proceeding claims
wherein the intermediate bending point comprises first bending point
and the point at which the inner panel is adjoined with the outer panel
comprises second bending point.
. .
5. A pedestrian protection hood for improved energy absorption during I pedestrian head impact as claimed in ally of the preceding claims is
associated with the advantageous features such as herein described.
I P O DELHI
6. A pedestrian protection hood for improved energy absorption during
pedestrian head impact substantially as herein described with reference
to the accompanying drawings.