FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
(SEE SECTION 10; RULE 13)
"VEHICLE BQNNET STRUCTURE FOR PEDESTRIAN PROTECTION"
MAHINDRA & MAHINDRA LIMITED
AN INDIAN COMPANY,
R&D CENTER, AUTOMOTIVE SECTOR,
89, M.I.D.C, SATPUR,
NASHIK-422 007,
MAHARASHTRA, INDIA.
THE FOLLOWING SPECIFICATION DESCRIBES THE NATURE OF THE INVENTION AND MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF INVENTION:-
The present invention is related to vehicle bonnet structure. More particularly the present invention is related to bonnet structure having deformable head impact zone and used in automobile vehicle and like other vehicles that protects the pedestrian at the time of impact.
BACKGROUND OF THE PRESENT INVENTION:-
Most of the vehicle bonnets include a generally planar or curvilinear outer skin which is joined to a series of reinforcing ribs provided by a stamped metallic sheet of material. During vehicle and pedestrian collision, it is observed that the pedestrian is seriously injured due to the pedestrian's head striking the bonnet of the vehicle. To keep the risk of injury as low as possible, controlled resilience in the head impact region of the bonnet is required. The present invention addresses this problem and provides the novel bonnet structure that will protect the pedestrian in case of pedestrian impact by absorbing the impact energy.
OBJECTIVES OF THE PRESENT INVENTION:-
The main objective of the present invention is to provide vehicle bonnet structure for pedestrian protection.
Another objective of the present invention is to provide vehicle bonnet structure with semi-spherical bulbs having a definite cut outs for pedestrian protection.
Another objective of the present invention is to provide vehicle bonnet structure for pedestrian protection wherein head impact energy is absorbed by the semi-spherical structures by undergoing deformation.
Accordingly the invention provides the vehicle bonnet structure for pedestrian protection comprises outer panel between front end and wind shield of vehicle;

an inner panel disposed and secured along the entire region of a reverse surface of the said outer panel; the plurality of Semi-spherical configurations; each semi-spherical configuration having the plurality of cuts on the periphery are provided on the inner panel of the bonnet; a bead is provided on the top of each of the said semispherical structure ; the said semi-spherical structure with bead accommodated between said inner panel and outer panel.
BRIEF DESCRIPTION OF THE FIGURES:-
The invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, wherein
Figure 1 shows isometric view of panel of a bonnet structure in accordance with the present invention.
Figure 2 shows bonnet structure wherein semi-spherical projections on the panel are deformed due to the head impact.
Figure 3 shows acceleration versus time plot and HIC criteria of a location on the hood.
DETAILED DESCRIPTION OF THE PRESENT INENTION:-
The vehicle bonnet structure is located between the front end and a windshield of a vehicle. The vehicle bonnet structure comprises of an outer panel structuring a vehicle body outer side surface, an inner panel disposed along the entire region of a reverse surface of the bonnet outer panel and secured to the outer panel. Semi-spherical configurations (1) with specially made cuts (2) are provided on the inner panel of the bonnet as disclosed in Figure 1. Each semi-spherical structure is provided with the bead (3) on the top of the semi-spherical structure (1). The semi-spherical structures (1) with cut outs (2) provides the flexibility of changing the stiffness as required for the head impact

at particular location by changing the cutout size, thickness, sphere diameter and by adding bead on the sphere. The semi-spherical structures with cut outs are accommodated in between the space between inner panel and outer panel of the bonnet and outer panel of the bonnet rests on the beads of the semi-spherical structure. The semi-spherical structure is provided with plurality of cuts along its periphery.
In case of pedestrian impact on the outer panel of the bonnet, the semi-spherical structure on the inner panel absorbs the impact energy and undergoes deformation as shown in Figure 2; thus protecting the pedestrian from serious injury.
Head impact criteria (HIC), sometimes called as head performance criteria, is measured by a spherical like object simulating the pedestrian head is impacted with the bonnet. The spherical object has an accelerometer mounted therein and HIC is calculated from the resultant of accelerometer time histories. Because of this semi-spherical structure on the inner panel of the bonnet HIC value is reduced too much below the permissible limit as shown in Figure 3. This design can be adopted for different vehicle engine layout by altering the stiffness. This design gives the flexibility of changing the stiffness as required for the head impact at particular location by changing the cutout size, thickness, sphere diameter and by adding bead on the sphere.
The bonnet structure for automotive vehicle as disclosed herein can be made in plastic or metal sheets or combination of thereof. Also the inner panel of the bonnet can be made of metal sheet and the semi-spherical structure can be made of suitable grade of plastic. The impact absorbing semi-spherical structures can be the add-on kind of fittings to the inner panel of the bonnet. The bonnet inner panel with semi-spherical structures can be made by forming to get an integrated inner panel. In case of modular inner panel the semi-spherical structures can be attached to the inner panel by clinching and/or riveting processes.

WE CLAIM:-
1. The vehicle bonnet structure for pedestrian protection comprises outer panel between front end and wind shield of vehicle; an inner panel disposed and secured along the entire region of a reverse surface of the said outer panel; the plurality of Semi-spherical configurations having the plurality of cuts on the periphery are provided on the inner panel of the bonnet; a bead is provided on the top of each of the said semispherical structure ; the said semi-spherical structure with bead accommodated between said inner panel and outer panel.
2. The vehicle bonnet structure as claimed in claim 1 wherein the said bonnet structure for automotive vehicle as disclosed herein made in plastic or metal sheets or combination of thereof.
3. The vehicle bonnet structure as claimed in claims 1 to2 wherein the inner panel of the bonnet made of metal sheet and the semi-spherical structure made of suitable grade of plastic fulfilling the requirement to absorb the head impact.
4. The vehicle bonnet structure as claimed in claims land 3 wherein the cutout size, thickness, sphere diameter and adding bead on the sphere of the said semi-spherical structures decided as per the stiffness as required for the head impact at particular location.
5. The vehicle bonnet structure as claimed in claims 1 to 4 wherein the said bonnet inner panel with semi-spherical structures made by forming process to get an integrated inner panel.

6. The vehicle bonnet structure as claimed in claims 1 to 5 wherein the modular inner panel the semi-spherical structures attached to the inner panel by clinching and/or riveting processes.
7. The vehicle bonnet structure as claimed in claims 1 to 6 wherein the said semi-spherical structures are the add-on kind of fittings to the inner panel of the bonnet.