FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
AND
THE PATENTS RULES, 2003
"COMPLETE SPECIFICATION"
(SEE SECTION 10; RULE 13)
"VEHICLE HOOD PANEL WITH STIFFENER 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 PARTICULARLY DESCRIBES AND ASCERTAINS THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE INVENTION:-
The present invention is related to vehicle body systems. More particularly the present invention is related to vehicle hood panel targeted to reduce the injuries in the event of pedestrian head impact.
BACKGROUND OF THE PRESENT INVENTION:-
In today's automotive field, human safety has become an important aspect in designing automotive systems. A variety of vehicle body systems targeted to protect the pedestrian in case of impact are available in public domain with varying degree of success.
Japanese patent application No. JP.2009137525 discloses hood structure of vehicle to more effectively perform shock absorbing at a front position of a stiffener part while securing dent resistance. But it does not talk about impact energy absorption during pedestrian impact. UK patent No. GB.928722 discloses improvements in hoods for vehicles wherein the hem of a hood contains a stiffener provided with elongated holes through which the fixing bolts pass thereby allowing some degree of adjustment of the hood tension. Though it talks about hood panel with stiffener, it does not talk about energy absorbing phenomenon in case of pedestrian impact.
Japanese patent application No. JP.2009029194 describes engine hood of vehicle to enhance shock absorbing performance by sufficiently securing a crash stroke when an object collides with an engine hood from above. When an object collides with the top surface of an engine hood of a vehicle formed by joining an outer frame of a stiffener to the inner surface of a skin through a space, a bridge forcing the outer frame of the stiffener connected thereto in a vehicle longitudinal direction is transformed downward by being pressed by the skin transformed downward toward the engine room. At that time, a U-shaped curved part formed in the bridge is stretched so that the skin can be substantially transformed downward without being hampered by the stiffener.

As a result, impact absorbing performance can be enhanced by sufficiently securing a crush stroke downward of the engine hood.
In this prior art document, a U-shaped structure is provided at the inner panel, which provide the more elongation length to sheet metal of inner panel during impact eventually deflection is high in this case. However, the present invention works opposite to it.
OBJECTIVES OF THE PRESENT INVENTION:-
The main objective of the present invention is to provide vehicle hood structure for pedestrian protection in case of impact.
Another objective of the present invention is to provide vehicle hood panel with stiffeners having a definite profile for pedestrian protection in case of impact.
Another objective of the present invention is to provide vehicle hood structure for pedestrian protection wherein head impact energy is absorbed by the stiffeners by undergoing deformation.
Still another object of the present invention is to provide low cost solution to reduce the head injury criteria (HIC) while pedestrian head impact with the hood.
STATEMENT OF INVENTION:-
Accordingly the invention provides a The vehicle hood panel with stiffener for pedestrian protection comprises an outer panel, an inner panel and a stiffener pad in the sheet form having number depression formation on the surface; the said stiffener pad is integrated with the outer panel with the help of suitable adhesives or sealers; the said outer panel and inner panel are connected together by hemming so that the stiffener pad is positionally sandwiched between inner panel and outer panel of the hood of a vehicle.

DESCRIPTION OF THE FIGURES:-
Figure 1 shows the outer panel of the hood with the stiffener integrated with it in accordance with the present invention.
Figure 2 shows plan view of stiffener pad and the bead pattern according to the present invention.
Figure 3 shows the cross sectional view of stiffener across the A-A in figure 2.
DETAILED DESCRIPTION OF THE PRESENT INVENTION:-
In accordance with the present invention, the hood system of a vehicle comprises of outer panel (1), inner panel (not shown) and stiffener pad (2). The stiffener pad is having the bead pattern according to the present invention. This bead pattern is formed by depression (3) on the surface of the said stiffener pad (2) as illustrated in the figures 2 and 3. The stiffener pad (2) is integrated with the outer panel (1) with the help of suitable adhesives or sealers as illustrated in figure 1. Outer panel (1) and inner panel are connected together by hemming. Thus, the stiffener pad (2) is positionally sandwiched between inner panel and outer panel of the hood of a vehicle.
When there is a pedestrian head impact on outer panel of the hood, the stiffener pad absorbs the impact energy with minimum deflection of the hood panel. This solution eliminates the need of raising the height of the bonnet or to push the engine assembly down so as to create a gap between hood surface and engine hard points. This novel arrangement of hood panels with stiffeners absorbs adequate amount of impact energy with less deflection of hood structure. Thus it avoids the contact between pedestrian head and engine hard point and subsequent head injuries. The stiffener is placed from inside the Hood Outer Panel. Stiffener and Outer Panel are joined together using adhesives or sealers.
The said stiffener pad is made of plastic sheet. And said outer and inner panel are made of metallic sheet.

The present invention is different in terms of flexibility of inner panel design and stiffener connection. It provides the energy absorbing phenomenon to maximum part of the hood and especially where the gap between inner panel and inner component of engine compartment is very less. It gives cost effective solution for absorbing the energy. The geometry, profile, orientations and dimensions of the ribs of the stiffener pad can be changed to achieve required stiffness without differing from the spirit of the invention for lowering the HIC value.
The advantages of the present invention are-
• It is simple in design
• It is a low cost solution
• It is easy to assemble and repair
• It is produced using conventional processes
• It is easy to apply in existing hood design

WE CLAIM:-
1. The vehicle hood panel with stiffener for pedestrian protection comprises an outer panel, an inner panel and a stiffener pad in the sheet form having number depression formation on the surface; the said stiffener pad is integrated with the outer panel with the help of suitable adhesives or sealers; the said outer panel and inner panel are connected together by hemming so that the stiffener pad is positionally sandwiched between inner panel and outer panel of the hood of a vehicle.
2. The vehicle hood panel as claimed in claim 1 wherein the said depression formation on the said stiffener pad are parallel and at equidistant.
3. The vehicle hood panel as claimed in claims 1 and 2 wherein the said stiffener pad is made of elastic plastic material.
4. The vehicle hood panel as claimed in claims 1 to 3 wherein the said outer panel and inner panel formed by metal sheet.