FIELD OF INVENTION:
[001] The present subject matter described herein, relates to an impact energy absorber structure for hood of vehicle, and, in particular, to a deformable energy absorbing brackets/structure in vehicle hood hinge region to absorb impact energy thus protecting head of pedestrian and reducing injury to pedestrian upon impact. In more particularly, the present subject matter relates to two deformable energy absorbing structures in vehicle hood hinge region for reducing pedestrian head injury during collision of pedestrian head with vehicle hood hinge region.
BACKGROUND AND PRIOR ART:
[002] A hood of vehicle is provided at front end of the vehicle to cover the engine compartment of the vehicle. The hood contributes in adding aesthetics to the vehicle. Generally, the hood is mounted on the front portion of the vehicle with hinges at two ends, i.e., right side and left side. There can be two types of hinges, i.e., single joint hinge and multi joint hinge. Further, Single joint hinges can be non-collapsible type or collapsible type.
[003] The hood protects head of pedestrian from direct hitting with hard components, such as engine, battery, etc., in the engine compartment. When the vehicle hits the pedestrian from front, the vehicle impacts knee, leg, and femur region of the pedestrian. The frontal impact may elevate and/or flip the pedestrian such that the pedestrian's head strikes the vehicle's hood or windshield. The head impact with the hood or windshield may be fatal if the head suffers high energy impact. When the pedestrian is flipped on the hood of the vehicle, head of the pedestrian hits indirectly via the hood against a hard member, such as an engine, battery, cooling system, junction box, and hood hinge that is provided at least partly below the hood of the vehicle. Magnitude of the head impact injury depends on the area of impact on the front hood of the vehicle, under hood components layout and even on hood system structure in itself. Further, the area of impact is influenced by many components, such as outer panel of hood, inner panel of hood, hinge reinforcement of hood, hinge region, fender, wiper system, and cowl area.
[004] Fig. 1a, 1b, and 1c illustrate hood hinge assembly of hood hinge region of the vehicle as known in the art. The hood of vehicle is generally a closure which is placed over engine compartment. Further, rear end of the vehicle hood is connected to the vehicle body by special hood hinges. The hinge assembly has collapsible hinge bracket 101 and hinge arm 103. The collapsible hinge bracket 101 is mounted on lower front base 104 of the vehicle body, specifically cowl panel. The hinge arm 103 is attached to the lower part of the vehicle hood 102. The hinge arm 103 is mounted on the inner panel of the hood 102 with mounting bolts 105 at plurality of locations, specifically, at two locations. The collapsible hinge bracket 101 is pivotally connected with the hinge arm 103 to allow up and down movement along the pivot axis. During the head impact of the pedestrian on the area of hinge on the hood of vehicle, the impact force pushes the hood in downward direction for absorption of impact force. The collapsible bracket 101 collapse to absorb some part of the impact energy. Further, a space ‘Y’ is provided in body structure, either by making grooves in adjacent parts or by avoiding any part in the concerned region, to ensure downward movement of hinge arm, in case of impact.
[005] Fig. 2 illustrates another hood hinge assembly of hood hinge region of vehicle as known in the art. The figure also depicts the space between hood and vehicle body available or provided to absorb impact energy during head impact of the pedestrian with hood hinge region of the vehicle. In this structure of the vehicle hood, the hood of vehicle is generally mounted to the vehicle body by conventional hood hinge assembly. The hinge assembly has non-collapsible hinge bracket 201 and hinge arm 203. The non-collapsible hinge bracket 201 is mounted on lower front base 204 of the vehicle body, specifically cowl panel. The hinge arm 203 is fixed to lower part of the vehicle hood 202. The hinge arm 203 is mounted on the inner panel of the vehicle hood 202 with mounting bolts at plurality of locations, specifically, at two locations. The non-collapsible hinge bracket 201 is pivotally connected with the hinge arm 203 to allow up and down movement along the pivot axis. Further, the cowl panel is as per older design philosophy, i.e., considerations for pedestrian headform like space for hinge arm movement, collapsible structure, sufficiency of gap from hard point is not available or is very less. During the head impact of the pedestrian near the area of hinge on the hood of vehicle, the impact force pushes the hood in downward direction for absorption of impact force. To absorb the head impact energy, there is a gap Y’ provided in between the lower surface of the inner panel of vehicle hood 202 and the vehicle body 204. However, the gap Y’ with vehicle body 204 is very less and it restrict downward movement of the hinge arm 203 and head of the pedestrian hits the hard component with high impact force magnitude. Due to low impact energy absorbing capabilities of the present hinge assembly, the head of the pedestrian incurs injuries with high injury values.
[006] Nowadays, the upcoming regulation on pedestrian protection mandates that the vehicle hood be configured to attenuate injury to the pedestrian when the pedestrian is struck by the vehicle and fallen on the hood.
[007] To satisfy the regulatory requirements, several systems have been proposed for protecting the pedestrian head during the impact. In one such system, a sufficiently large gap between the vehicle hood member and its underlying components is suggested to absorb impact energy. However, the gap between the vehicle hood and vehicle body above the threshold limit is difficult due to vehicle design constraints, such as styling limitations, aerodynamics requirements, layout requirements etc. In another suggested system, a deformable collapsible hinge bracket is provided in the hinge assembly for reducing the impact of the pedestrian head on area of the vehicle hood hinge as explained with Fig 1a, 1b and 1c.
[008] Pedestrian safety being an important concern with an ever increasing number of vehicles on roads which thereby forces government to bring Pedestrian safety regulation norms in near future. Hood hinge area is one of the most critical areas to meet the HIC (Head Injury Criteria). It becomes more challenging when the same is to be incorporated in existing vehicle structure ensuring minimum changes to surrounding part structure. The current structure of the hood does not comply with required HIC in hinge region. Further, there is no sufficient space available for hinge arm movement on impact. Due to small gap between the lower part of the hood and the vehicle body, the head of the pedestrian directly hits the hinge arm onto the panel leading to increased injury values as explained with structure shown in Fig 2. The biggest problem in the existing vehicle structures is to make them safe for pedestrian without changing the layout and structure of the vehicle. Another challenge is to maintain the cost and weight of the vehicle while ensuring safety of the pedestrian head.
[009] To reduce the possibility of severe injury or lower the head injury during pedestrian head impact it has been suggested to raise the hood so as to increase the gap between the lower part of the hood and the under hood hard points and provide a collapsible type hinge assembly so as to achieve the structure similar to that explained with Fig 1a, 1b and 1c. However, these changes require modification in styling. Further, this require structural changes in the vehicle which have significant cost implications.
[0010] Other technical problems or challenges also exists. they are:
[0011] There is no sufficient space available for hinge arm movement on impact – the less gap with the adjacent cowl panel leads to direct hitting of the hinge arm onto the panel leading to increased injury values. The concerned cowl panel structure is designed as per older design philosophy (when there is no pedestrian compliance requirement) and is thus had very hard box section structure. Its modification is not feasible as it will lead to major structural changes.
[0012] Modification in existing body structure parts is difficult due to layout constraints
[0013] Shape modification in existing body structure leads to new tooling – cost up
[0014] Weight increase is to be minimized while ensuring pedestrian compliance
[0015] Cost up to be monitored and controlled while ensuring pedestrian compliance
[0016] Accordingly, it is desirable to develop an impact energy absorber structure in the hood hinge region that overcomes the foregoing and other problems and disadvantages as mentioned. Therefore, there is a need in the art to provide an impact energy absorber structure that can be more simple and inexpensive, and which can be placed in the existing structures with minimum modifications in the hood structure and hinge region of the vehicle to fulfill the regulations of the pedestrian safety.
OBJECTS OF THE INVENTION:
[0017] The principal object of the present invention is to provide an impact energy absorber structure to absorb head impact energy on hood of the vehicle and reduces injuries to pedestrian head.
[0018] Another object of the present subject matter is to provide a deformable energy absorber structure that deforms to absorb the impact energy during head impact with the hood of the vehicle.
[0019] Another object of the present subject matter is to provide a deformable energy absorber structure in vehicle hood.
[0020] Another object of the present subject matter is to provide a deformable energy absorber structure in between cowl panel and the hinge arm.
[0021] Yet another object of the present invention is to provide an impact energy absorber which is simple and inexpensive, and efficiently absorbs the head impact energy on hood hinge area thereby reduces injury to the pedestrian head.
[0022] Yet another object of the present invention is to provide a deformable energy absorber structure which can be implemented in existing vehicles without any major structural modifications.
[0023] Yet another object of the present invention is to make existing vehicles pedestrian safe by implementing the impact energy absorber structure.
SUMMARY OF THE INVENTION:
[0024] The subject matter disclosed herein relates to deformable energy absorbing structure in the vehicle hood assembly for reducing the impact of pedestrian head injuries during impact of the pedestrian head with vehicle hood, in particularly, to vehicle hood hinge region which is one of the hardest zone on the vehicle hood area from pedestrian impact perspective. The vehicle hood assembly has vehicle hood, two hood hinge assemblies and two deformable energy absorbing brackets. The vehicle hood is pivotally connected with the vehicle body through the hinge assembly for up and down movement about horizontal pivot axis to open and close position of engine compartment in the vehicle, respectively. The hinge assembly has hinge arm and non-collapsible hinge bracket. The non-collapsible hinge bracket is mounted on the vehicle body, specifically cowl top panel. The hinge arm is mounted on the vehicle hood inner panel from one end through hinge mounting bracket and pivotally connected with the non-collapsible bracket at other end. Similarly, another hinge assembly is provided on the other end of the vehicle hood to allow pivot movement of the vehicle hood.
[0025] In the vehicle hood, a first deformable energy absorbing bracket is provided in between the vehicle hood inner panel and the vehicle hood outer panel. The deformable energy absorbing bracket deforms and absorbs impact energy during head impact. The second deformable energy absorbing bracket is provided on cowl panel to prevent direct hitting of hood hinge arm with the cowl panel as it comes between the hood hinge arm (during downward movement) and the cowl panel.
[0026] In an aspect, the first and the second deformable energy absorbing brackets have hat section profile and made from a single sheet material.
[0027] In an aspect, the first deformable energy absorbing bracket covers mounting of the hinge arm and the vehicle hood.
[0028] In an aspect, the hinge arm overlaps the second deformable energy absorbing bracket in such a way that the hinge arm hits the second deformable energy absorbing bracket at initial stage of the collision, the second deformable energy absorbing bracket deforms upto a predefined limit to absorb collision impact energy, and the hinge arm slides away from the second deformable energy absorbing bracket to absorb further collision impact when the second deformable energy absorbing bracket is deformed upto the predefined limit.
[0029] In an aspect, the first deformable energy absorbing bracket and the second deformable energy absorbing bracket are made from single material, such as steel or aluminium, etc.
[0030] In an aspect, the first deformable energy absorbing bracket and the second deformable energy absorbing bracket are mounted on the vehicle hood inner panel and the cowl panel, respectively by means of bolting, spot welding, carbon dioxide welding.
[0031] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0033] Fig. 1a, 1b, and 1c illustrate hood hinge assembly with collapsible bracket to absorb head impact energy during head impact of pedestrian with hood hinge region of the vehicle as known in the art;
[0034] Fig. 2 illustrates hood hinge assembly having non-collapsible hinge bracket with space between hood and vehicle body to absorb impact energy during head impact of the pedestrian with hood hinge region of the vehicle as known in the art;
[0035] Fig. 3 illustrates vehicle hood assembly along cross section BB, in accordance with an embodiment of the present subject matter;
[0036] Fig. 4 illustrates structure of deformable energy absorbing bracket in the vehicle hood along cross section BB, in accordance with an embodiment of the present subject matter; and
[0037] Fig. 5 illustrates vehicle hood hinge assembly having hinge arm, energy absorbing bracket and cowl panel, in accordance with an embodiment of the subject matter.
[0038] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0039] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0040] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0041] Fig. 3 illustrates structure vehicle hood assembly, in accordance with an embodiment of the present subject matter. Fig. 4 illustrates cross section view along line BB’ of Fig. 3. As shown in fig. 4, a first deformable energy absorbing bracket 302 is provided in between a vehicle hood inner panel 301b and a vehicle hood outer panel 301a of the vehicle hood 301. The first deformable energy absorbing bracket 302 deforms and absorbs impact energy during head impact. The first deformable energy absorbing bracket 302 is mounted on the vehicle hood inner panel 301b and covers the mounting of the vehicle hood 301 and the hinge arm 203. Therefore, the first deformable energy absorbing bracket 302 absorbs the impact of collision at mounting of the vehicle hood and the hinge arm 203 mounting area. The bracket has specific shapes which help its deformation when pedestrian head impacts in the hood hinge region. While at the same time the absorber bracket 302 is not too stiff so as not to absorb energy during head impact and itself becoming a hard point resulting in higher HIC.
[0042] A second deformable energy absorbing bracket 303 is provided on a cowl panel 304 to prevent direct hitting of the hinge arm 203 with the cowl panel 304 as it comes between the hinge arm 203 (during downward movement) and the cowl panel 304 (as shown in the figure 5). The first and the second deformable energy absorbing brackets 302, 303 have hat section profile and made from a single sheet material. The first and the second deformable energy absorbing brackets 302, 303 are mounted on the vehicle hood inner panel 301b and the cowl panel 304 by flanges of their hat shape profile.
[0043] In the present subject matter, structure of hood hinge area is optimized by addition of two deformable energy absorbing brackets 302, 303 through specific shapes in absorber brackets and their thickness so as to prevent hitting of hinge arm with hard points (panel cowl 304) for energy absorption without affecting the performance requirements of strength and vehicle performance.
[0044] Fig. 5 shows view along CC of fig. 3, in accordance with an embodiment of the present subject matter. As shown in the fig. 5, the second deformable energy absorbing bracket 303 is provided on the cowl panel 304. The second deformable energy absorbing bracket 303 is provided in between the hinge arm 203 and the cowl panel 304. During the impact, the hinge arm 203 hits the second deformable energy absorbing bracket 303 in downward direction.
[0045] Fig. 5 show positioning of the second deformable energy absorbing bracket 303 in between the hinge arm 203 and the cowl panel 304. As viewing from top view, the hinge arm 203 overlaps the deformable energy absorbing bracket 303 on panel cowl 304. The overlap is optimized in such a way that hood hinge arm 203 hits the deformable energy absorbing bracket 303 for some time, during which deformable energy absorbing bracket 303 deforms, and then hinge arm 203 slides from the deformable energy absorbing bracket 303. Deformation of the deformable energy absorbing bracket 303 and sliding of the hinge arm 203 from the deformable energy absorbing bracket 303 helps in optimization of HIC value achieved in hinge area, also avoiding the hitting of hinge arm 203 with panel cowl 304 which is hard point in this case.
[0046] In an embodiment, the hinge arm 203 overlaps the second deformable energy absorbing bracket 303 in such a way that the hinge arm 203 hits the second deformable energy absorbing bracket 303 at initial stage of the collision, the second deformable energy absorbing bracket 303 deforms upto a predefined limit to absorb collision impact, and the hinge arm 203 slides away from the second deformable energy absorbing bracket 303 to absorb further collision impact when the second deformable energy absorbing bracket 303 is deformed upto the predefined limit.
[0047] This has been done as it has been observed that if overlap is too much, the hinge arm hits the second deformable energy absorbing bracket 303, which after deformation upto a predefined limit, acts as a hard point, thereby increasing HIC values. Therefore, sliding of the hinge arm 203 away from the deformable energy absorbing bracket 303 is provided to prevent the second deformable energy absorbing bracket 303 to become hard point due to deformation.
[0048] The first and the second deformable energy absorbing bracket 302, 303 can be manufactured easily by combination of stamping, punching, and bending operation.
[0049] The first and the second deformable energy absorbing bracket 302, 303 can be made of steel (any grade), Aluminum or with equivalent stiffness. Stiffness can also be managed by varying the thickness of energy absorbing bracket.
[0050] The first and the second deformable energy absorbing brackets can be mounted to the vehicle hood and hinge region by means of bolts, spot weld or CO2 welding.
[0051] The present first and the second deformable energy absorbing brackets reduce Head Injury Criteria (HIC) value at the hood hinge region. The structure of the present deformable brackets allow better energy absorbing capabilities during head impact at the hood hinge region.
[0052] It is easy to manufacture and assemble the present deformable energy absorbing brackets in the existing vehicles. There is no requirement to change the current structure of the existing vehicles so there is no significant modification cost. Further, there is no requirement to change the current layout. The present deformable energy absorbing brackets can be implemented in the existing vehicle to make the existing vehicles safe for pedestrian. The present deformable energy absorbing bracket in the vehicle hood assembly meets the required HIC value for complying pedestrian safety regulations. The present deformable energy absorbing brackets are light weighted so addition of deformable energy absorbing bracket does not add too much extra weight to the vehicle. Further, the present deformable energy absorbing brackets do not need any special welding facilities. Therefore, the present deformable energy absorbing bracket can be implemented in the existing vehicle using existing facilities.
[0053] Less time required for compliance development
[0054] No major change in In-house welding jig facility required
[0055] Can be adopted across models having similar structure constraints
[0056] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

We claim:
1. A vehicle hood assembly for absorbing pedestrian head impact energy during collision of vehicle with pedestrian head at hood hinge region, the vehicle hood assembly comprising:
a vehicle hood (301) pivotally mounted with a cowl panel (304) through a hinge assembly, the hinge assembly comprises a hinge arm (203) and a hinge mounting bracket (201), the hinge arm (203) pivotally mounted on the cowl panel (304) from one end through the hinge mounting bracket (201) and other end is connected with the vehicle hood (301); and
characterized in that
a first deformable energy absorbing bracket (302) is provided in between vehicle hood inner panel (301b) and vehicle hood outer panel (301a);
a second deformable energy absorbing bracket (303) is provided in between the hinge arm (203) and the cowl panel (304) to prevent direct hitting of the hinge arm (203) with the cowl panel (304).
2. The vehicle hood assembly as claimed in claim 1, wherein the first deformable energy absorbing bracket (302) and the second deformable energy absorbing bracket (303) defines hat section profile.
3. The vehicle hood assembly as claimed in claim 1, wherein the first deformable energy absorbing bracket (302) is mounted on the vehicle hood inner panel (301).
4. The vehicle hood assembly as claimed in claim 1, wherein the first deformable energy absorbing bracket (302) is located in the hood hinge region specifically covering the mounting of the hinge arm (203) and the vehicle hood (301).
5. The vehicle hood assembly as claimed in claim 1, wherein the second deformable energy absorbing bracket (303) is mounted on the cowl panel (304).

6. The vehicle hood assembly as claimed in claim 1, wherein the hinge arm (203) overlaps the second deformable energy absorbing bracket (303) in such a way that the hinge arm (203) hits the second deformable energy absorbing bracket (303) at initial stage of the collision, the second deformable energy absorbing bracket (303) deforms upto a predefined limit to absorb collision impact, and the hinge arm (203) slides away from the second deformable energy absorbing bracket (303) to absorb further collision impact when the second deformable energy absorbing bracket (303) is deformed upto the predefined limit.
7. The vehicle hood assembly as claimed in claim 1, wherein the first deformable energy absorbing bracket (302) and the second deformable energy absorbing bracket (303) are made from a material selected from steel or aluminum, etc.
8. The vehicle hood assembly as claimed in claim 1, wherein the first deformable energy absorbing bracket (302) and the second deformable energy absorbing bracket (303) are mounted on the vehicle hood inner panel (301b) and the cowl panel (304), respectively by means of bolting, spot welding, carbon dioxide welding.
9. The vehicle hood assembly as claimed in claim 1, wherein the first deformable energy absorbing bracket (302) and the second deformable energy absorbing bracket (303) are manufactured by combination of stamping, punching, and bending operations.