FIELD OF INVENTION:
[001] The present subject matter described herein, relates to a hinge assembly for hood of vehicle, and, in particular, to a multi joint hinge assembly which can absorb pedestrian head impact energy thus protecting head of pedestrian and reducing injury to pedestrian upon impact. In more particularly, the present subject matter relates to deformable structure of the multi joint hinge assembly for the vehicle hood hinge for reducing pedestrian head injury during head collision pedestrian with hood/bonnet of the vehicle.
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 provides aerodynamic features to the vehicle. Generally, the vehicle 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.
[003] The hood protects head of pedestrian from direct hitting with hard components, such as engine, battery in the engine compartment. The frontal impact may elevate and/or flip the pedestrian such that the pedestrian's head strikes the vehicle's hood or windshield. When the pedestrian is flipped on the hood of the vehicle, the head of the pedestrian hits indirectly via the hood against a hard member, such as an engine, battery, cooling equipment, junction box, and hood hinge that is provided at least partly below the vehicle. Magnitude of the head impact injury depends on the area of impact on the hood of the vehicle. 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, cowl area etc.
[004] Fig. 1 and 2 illustrate single joint 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. The hood of vehicle is generally a metal lid which is placed over engine compartment. Further, rear end of the vehicle hood connected to the vehicle body by hood hinges. The hinge assembly has collapsible hinge bracket 101 and dog leg hinge arm 102. The collapsible hinge bracket 101 is mounted on lower front base 105 of the vehicle body, specifically cowl panel. The dog leg hinge arm 102 is positioned below the lower part of the vehicle hood 104. The dog leg hinge arm 102 is mounted on the inner panel of the hood 104 with mounting bolts 103 at plurality of locations, specifically, at two locations. The collapsible hinge bracket 101 is pivotally connected with the dog leg hinge arm 102 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 the impact energy. However, the collapsible hinge bracket reduces the capability of hinge assembly to restrict inside movement of the vehicle hood during frontal crash. Further, the collapsible bracket does not provide rigidity to the vehicle hood and does not absorb the head impact energy efficiently especially very large amounts of impact energy.
[005] Nowadays, the 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.
[006] In order to satisfy the regulation, several systems have been proposed for protecting the pedestrian head during the impact. In German Patent Publication DE102015013707A1, discloses a vehicle with a lift-able hood. The German patent discloses a vehicle with a detected collision in a passenger facing at one of a windshield edge lift-able hood. According to the invention an actuator for lifting the bonnet in a kinematics module, which comprises at least a hinge integrated. A major drawback of this arrangement is that it has an actuator which actuates and lift the hood upon collision. The module of actuator requires a sensor for actuating and then actuator itself is a complex structure. Further, this arrangement is expensive and complex.
[007] Chinese Patent publication CN1352606A discloses a front hood system has a front hood of a vehicle that is coupled to the frame of the vehicle via at least one multiple-joint hinge. In addition, the vehicle's front opening hood can be latched by means of at least one hood lock. At least one multiple-joint hinge has at least one link that can separate into at least two parts due to the force of impact of a pedestrian. The Chinese patent publication discloses that at least one multiple joint hinge has at least one link which can separate into at least two parts due to the force of impact of a pedestrian which is a disadvantage. Further, it also has four bar linkage and have more rotation axis.
[008] EP patent publication EP2351671A1 discloses a hinge has an upper hinge wing with upper and lower parts that are articulately connected with each other. A relative motion of the upper part takes place in relation to the lower part from a normal position into a crash position after separation of a connection by a separating equipment, where the connection fixing the upper part with the lower part. The upper part lying in the normal position over a stopper element against a limiting element of the lower part. A contact surface running parallel to an adjustment direction of the upper part in relation to the lower part. The stopper and limiting element exhibit a plastic coating. The separating equipment comprises a pyrotechnic actuator with one out quickly ends in the event of a crash piston member, said actuator is so constructed and arranged that the piston element in the event of a crash. Drawback of this arrangement is that it uses a pyrotechnic actuator to lift the vehicle hood which is costly and complex.
[009] 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. Hood hinge area is one of the most critical areas to meet the HIC (Head Injury Criteria). 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.
[0010] To reduce or eliminate the possibility of severe injury resulting from a pedestrian hood strike or to reduce Head injury, several systems have been suggested to increase the gap between the lower part of the hood and the vehicle, and provide a collapsible bracket in the hinge assembly. Further, these systems are complex and costly. Accordingly, it is desirable to develop a multi joint hinge assembly that overcomes the foregoing and other problems and disadvantages as mentioned. Therefore, there is a need in the art to provide a multi joint hinge assembly that can be more simple and inexpensive, and which can be placed in the existing structures of the vehicle to fulfill the regulations of the pedestrian safety.
OBJECTS OF THE INVENTION:
[0011] The principal object of the present invention is to provide a multi joint hinge assembly for safety of pedestrian head during collision of pedestrian with vehicle.
[0012] Another object of the present subject matter is to provide a deformable multi joint hinge assembly to absorb the impact energy during head impact with the hood of the vehicle.
[0013] Another object of the present subject matter is to provide a multi joint hinge assembly for absorbing pedestrian head impact energy in a controlled manner and reduce the magnitude of head injuries to pedestrian.
[0014] 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 vehicle hood without causing major injury to head of the pedestrian.
SUMMARY OF THE INVENTION:
[0015] The subject matter disclosed herein relates to a multi joint hinge assembly which facilitates conventional opening and closing operation of vehicle hood along with pedestrian head impact energy absorbing capacity during pedestrian collision. The multi joint hinge assembly has a hinge arm and a base component. The hinge arm and the base component are connected with each other through a plurality of link component. The hinge arm is mounted on the vehicle hood and the base component is mounted on the vehicle body at lower side. The plurality of link components is first link component, second link component, and third link component. The first link component is provided in between the hinge arm and the base component. The first link component is connected with the base component through a first rotatable pivot joint with first pin from one end and with the hinge arm through a second pin movable in a horizontal slot of the hinge arm from other end. The hinge arm has a horizontal slot in which the second pin of the first link which is provided on the other end moves during opening and closing of vehicle hood. The second link component is connected with the hinge arm through a second rotatable pivot joint with third pin at one end. Other end of the second link component is connected with free end of the third link component through a third rotatable pivot joint with fourth pin which moves in a predefined second slot provided on the third link component. The third link component is connected with rear end of the base component through a fourth rotatable pivot joint with fifth pin on the other end. During the conventional opening and closing of the vehicle hood, the hinge arm mounted with vehicle hood moves up and down about the pivot axis of the third pin of the second rotatable pivot joint,. During opening and closing of the vehicle hood, the first link component slides in the horizontal slot of the hinge arm via the second pin on one end while rotating about the pivot axis of first pin of first rotatable pivot joint. Further, the hood rotation is achieved at the third rotatable pivot joint around axis of the third pin. The first pin connected with the first link component also rotates in clockwise and anti-clockwise direction when the vehicle hood moves up and down. In the operation of opening and closing of the vehicle hood, the second link and the third link remain stationary with their positions being locked by the first and second shear pin respectively.
[0016] In another embodiment of the present subject matter, the second link component is locked/fixed with the third link component through first shear pin. The first shear pin locked movement of the fourth pin of the second link component in the predefined second slot of the third link component. The fourth pin of the second link component is movable in the predefined second slot of the third link component. The third link component is locked with the base component through a second shear pin. The second shear pin locked rotation of the third component about the axis of fifth pin in the fourth rotatable pivot joint. Both the first shear pin and the second shear pin break when the impact force on the hinge assembly is more than predefined threshold force. When the pedestrian’s head and upper body strike the vehicle hood hinge area, the first shear pin provided between the second link component and the third link component breaks when impact force is above the threshold force. The breaking of the first shear pin allows movement of the fourth pin of the second link component in the predefined second slot of the third link component. Due to movement of second link component in the predefined second slot in downward direction, the vehicle hood also moves in downward direction thereby allowing to absorb the pedestrian head impact force. Upon breaking of the first shear pin, the hinge arm is freely rotatable around the third pin. The first pin moves in clockwise direction while the first link freely slides in the horizontal slot in the hinge arm. At the same time, the fourth pin slides in the second slot to bring the vehicle hood down. The downward motion of the vehicle hood helps to reduce the impact of pedestrian head collision and protects the pedestrian head from serious injuries.
[0017] In yet another embodiment of the present subject matter, when there is more severe impact from the pedestrian head, the increased impact value at the vehicle hood hinge area is not completely absorbed by the breaking of the first shear pin, the fourth pin reaches the other end of the predefined second slot of the third link component and applies pressure on the third link component. Due to pressure, the second shear pin breaks and allow rotation of the third link component in clockwise direction which helps in further lowering down the vehicle hood and absorb the impact force. In another embodiment, when second pin reaches the end of first slot, the second shear pin breaks down and allow clockwise rotation of the third link component. The third link component rotates in clockwise direction to bring the vehicle hood in downward direction to absorb the head impact force of pedestrian.
[0018] 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
[0019] 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:
[0020] Fig. 1, and 2 illustrate single joint 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;
[0021] Fig. 3 illustrates structure of multi joint hinge assembly, in accordance with an embodiment of the present subject matter;
[0022] Fig. 4 and 5 illustrate vehicle hood opening arrangement with the multi joint hinge assembly side view of the deformable reinforcement, in accordance with an embodiment of the present subject matter;
[0023] Fig. 6 and 7 illustrate working and absorbing pedestrian head impact force by lowering down the multi joint hinge assembly on breaking of first shear pin when pedestrian head impact force is applied on the vehicle hood, in accordance with an embodiment of the present subject matter; and
[0024] Fig. 8 and 9 illustrate further breaking of multi joint hinge assembly for lowering down the vehicle hood to absorb the head impact force, in accordance with an embodiment of the present subject matter.
[0025] 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:
[0026] The subject matter disclosed herein relates to a multi joint hinge assembly which facilitates conventional opening and closing operation of vehicle hood along with pedestrian head impact energy absorbing capacity during pedestrian collision. The multi joint hinge assembly mounted with vehicle hood and vehicle body and configured to move in downward direction to absorb pedestrian head impact force. The multi joint hinge assembly provides conventional opening and closing operation of hood with a plurality of link component. Further, the conventional opening and closing of vehicle hood is permitted through a single rotatable pivot joint. The multi joint hinge assembly has a hinge arm and a base component. The hinge arm and the base component are connected with each other through a plurality of link component. The hinge arm is mounted on the vehicle hood and the base component is mounted on the vehicle body at lower side. The plurality of link components is first link component, second link component, and third link component. The first link component is provided in between the hinge arm and the base component. The first link component is connected with the base component through a first rotatable pivot joint with first pin from one end and with the hinge arm through a second pin movable in a horizontal slot of the hinge arm from other end. The hinge arm has a horizontal slot in which the second pin of the first link which is provided on the other end moves during opening and closing of vehicle hood. The second link component is connected with the hinge arm through a second rotatable pivot joint with third pinon one end. Other end of the second link component is connected with free end of the third link component through a third rotatable pivot joint with fourth pin which moves in a predefined second slot provided on the third link component. The third link component is connected with rear end of the base component through a fourth rotatable pivot joint with fifth pin on other end. During the conventional opening and closing of the vehicle hood, the hinge arm mounted with vehicle hood moves up and down about the pivot axis of the third pin of second rotatable pivot joint. During opening and closing of the vehicle hood, the first link component slides in the horizontal slot of the hinge arm via the second pin. Further, the hood rotation is achieved at the third rotatable pivot joint around axis of the third pin. The first pin connected with the first link component also rotates in clockwise and anti-clockwise direction when the vehicle hood moves up and down. In the operation of opening and closing of the vehicle hood, the second link and the third link remain stationary with their positions.
[0027] In another embodiment of the present subject matter, the second link component is locked/fixed with the third link component through first shear pin. The first shear pin locked movement of the fourth pin of the second link component in the predefined second slot of the third link component. The fourth pin of the second link component is movable in the predefined second slot of the third link component. The third link component is locked with the base component through a second shear pin. The second shear pin locked rotation of the third component about the axis of fifth pin in the fourth rotatable pivot joint. Both the first shear pin and the second shear pin break when the impact force on the hinge assembly is more than predefined threshold force. When the pedestrian’s head and upper body strike the vehicle hood hinge area, the first shear pin provided between the second link component and the third link component breaks when impact force is above the threshold force. The breaking of the first shear pin allows movement of the fourth pin of the second link component in the predefined second slot of the third link component. Due to movement of second link component in the predefined second slot in downward direction, the vehicle hood also moves in downward direction to absorb the pedestrian head impact force. Upon breaking of the first shear pin, the hinge arm is freely rotatable around the third pin. The first pin moves in clockwise direction while the first link freely slides in the horizontal slot in the hinge arm. At the same time, the fourth pin slides in the second slot to bring the vehicle hood down. The downward motion of the vehicle hood helps to reduce the impact of pedestrian head collision and protects the pedestrian head from serious injuries.
[0028] When there is more severe impact from the pedestrian head, the increased impact value at the vehicle hood hinge area is not completely absorbed by the breaking of first shear pin, the fourth pin reaches the other end of the predefined second slot of the third link component and applies pressure on the third link component. Due to pressure, the second shear pin breaks and allow rotation of the third link component in clockwise direction which helps in further lowering down the vehicle hood and absorb the impact force. In another embodiment, when second pin reaches the end of first slot, the second shear pin breaks down and allow clockwise rotation of the third link component. The third link component rotates in clockwise direction to bring the vehicle hood in downward direction to absorb the head impact force of pedestrian.
[0029] 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.
[0030] 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.
[0031] Fig. 3 illustrates structure of multi joint hinge assembly, in accordance with an embodiment of the present subject matter. The multi hinge assembly 300 has a hinge arm 301 and a base component 302. The hinge arm 301 and the base component 302 are connected with each other through a plurality of link components 303, 304, 305. The hinge arm 301 is mounted on the vehicle hood and the base component 302 is mounted on the vehicle body structure at lower side. The hinge arm 301 is rigidly connected with the vehicle hood using bolting, welding or similar fastening means. Similarly, the base component 302 is rigidly connected with the vehicle body using bolting, welding or similar fastening means The plurality of link components is first link component 303, second link component 304, and third link component 305. The first link component 303 is provided in between the hinge arm 301 and the base component 302. The first link component 303 is connected with the base component 302 through a first rotatable pivot joint 306 with first pin 306a from one end. In the present subject matter, each rotatable pivot joint has a pin which can be a bushing or rivet or similar means to provide rotating operations in the pivot joint. Other end of the first link component 303 is connected with the hinge arm 301 through a sliding second pin 307 movable in a horizontal slot 311 of the hinge arm 301. The hinge arm 301 has a horizontal slot 311 in which the second pin 307 of the first link component moves during opening and closing of vehicle hood.
[0032] One end of the second link component 304 connected with the hinge arm 301 through a second rotatable pivot joint 308 with/via third pin 308a. Other end of the second link component 304 is connected with other end of the third link component 305 through a third rotatable pivot joint 309 via fourth pin 309a which moves in a predefined second slot 312 provided on the third link component 305. The fourth pin 309a anchored in the predefined second slot 312 of the third link component 305. The second link component 304 moves/slides in the predefined second slot 312 via the fourth pin 309a. The second link component 304 is locked/fixed with the third link component 305 through first shear pin 313. The first shear pin 313 locked movement of the fourth pin 309 of the second link component 304 in the predefined second slot 312 of the third link component 305. The fourth pin 309 of the second link component 303 is movable in the predefined second slot 312 of the third link component 305. One end of the third link component 305 connected with rear end of the base component 302 through a fourth rotatable pivot joint 310 with/via fifth pin 310a. The third link component 305 is locked with the base component 302 through a second shear pin 3014. The second shear pin 314 locked rotation of the third component about the axis of fifth pin 310a in the fourth rotatable pivot joint 310.
[0033] Referring to figure 4 and 5, during the conventional opening and closing of the vehicle hood, the hinge arm 301 mounted with vehicle hood moves up and down 401 about the pivot axis of the third pin 308a in the second rotatable pivot joint 308. In the conventional operations, the multi joint hinge assembly 300 operates as a single pivot configuration and facilitates convention opening and closing of vehicle hood relative to vehicle body via second rotatable pivot joint. During opening and closing of the vehicle hood, the first link component 303 slides forward and backward in the horizontal slot 311 of the hinge arm 301 via the second pin 307. Further, the vehicle hood rotation 402 is achieved at the third rotatable pivot joint 308 around axis of the third pin 308a. The first pin 306a connected with the first link component 303 also rotates 404 in clockwise and anti-clockwise direction when the vehicle hood moves up and down. Further, the direction of rotation of the first pin 306a and the third pin 308a is opposite to each other during opening and closing of vehicle hood. In the operation of opening and closing of the vehicle hood, the second link and the third link remain stationary 403 with their positions.
[0034] Figure 6 illustrates the direction of pedestrian head impact near the vehicle hood hinge area. 601 indicate the direction of pedestrian head impact on the vehicle hood. Fig. 7 illustrates working and absorbing pedestrian head impact force by lowering down the multi joint hinge assembly when pedestrian head impact force is applied on the vehicle hood, in accordance with an embodiment of the present subject matter. As illustrated in the figure 3, the second link component 304 is locked/fixed with the third link component 305 through the first shear pin 313. The first shear pin 313 locked movement of the fourth pin 309 of the second link component 304 in the predefined second slot 312 of the third link component 305. The third link component 305 is locked with the base component 302 through a second shear pin 314. The second shear pin 314 locked rotation of the third link component 305 about the axis of fifth pin 310a in the fourth rotatable pivot joint 310. Both the first shear pin 313 and the second shear pin 314 break when the impact force on the multi joint hinge assembly 300 is more than predefined threshold force. Also, the threshold force for both the shear pins are different, therby enabling the breaking of second shear pin only when the force increases beyond a specific limit post breaking of first shear pin. Further, the threshold limit of the impact force depends on the size and configuration of the vehicle hood and vehicle. Therefore, a multi hinge assembly made with present concept has different threshold limit for different vehicles. For example, the bearing capacity of the multi hinge assembly or the threshold limit of the multi hinge assembly can be increased or decreased by increasing or decreasing the dimensions of the shears pin.
[0035] When the pedestrian’s head and upper body strike the vehicle hood hinge area, the first shear pin 313 provided between the second link component 304 and the third link component 305 breaks when impact force is above the threshold impact force. The breaking of the first shear pin 313 allows movement of the fourth pin 309 of the second link component 304 in the predefined second slot 312 of the third link component 305. Due to movement of second link component 304 in the predefined second slot 312 in downward direction 604 via anchored fourth pin 309, the complete vehicle hood assembly also moves in downward direction to absorb the pedestrian head impact force. Upon breaking of the first shear pin 313, the hinge arm 301 is freely rotatable around the third pin 308a . At the same time, the second pin 307 slides in the first slot 311 to bring the vehicle hood down. Further, the hinge arm 301 rotates in anti-clockwise direction 603 which allows movement of fourth pin 309 in the predefined second slot 312. The downward motion of the vehicle hood helps to reduce the impact of pedestrian head collision and protects the pedestrian head from serious injuries. Upon breaking of first shear pin 313, the third pin 308a rotates and angle between the hinge arm 301 and the second link component 304 decreases or increases which brings the vehicle hood in downward direction and upward direction. When the first shear pin 313 breaks and the fourth pin 309 moves in the predefined second slot 312 and the hinge arm 301 rotates about the first pin 306a in the first rotatable pivot joint 306 and the second pin 301 slides in the horizontal slot 311 of the hinge arm 301. During the breaking of the first shear pin 313, the third link component 305 remains stationary about the base component 302 due to the second shear pin 314.
[0036] Fig. 8 and 9 illustrate breaking of second shear pin of multi joint hinge assembly for further lowering down the vehicle hood to absorb the head impact force, in accordance with an embodiment of the present subject matter. Referring to fig. 8, in case of further intrusion of pedestrian impact and increase in impact force value of pedestrian head impact at the vehicle hood hinge area in direction of 801. Due to more severe impact force from the pedestrian head impact, the increased impact value at the vehicle hood hinge area is not completely absorbed by the breaking of the first shear pin 313, the fourth pin 309 reaches the other end of the predefined second slot 312 of the third link component 305. Further, the fourth pin 309 applies pressure on the third link component 305 at the end. Due to continuous pressure and increased impact value, the second shear pin 314 breaks and allow rotation of the third link component 305 in clockwise direction 803 which helps in further lowering down 802 the vehicle hood and absorb the pedestrian head impact force during collision. In another embodiment, when the second pin 307 reaches the end of the first slot 311 and the first slot 311 restrict further movement of the second pin 307, the second shear pin 314 breaks down and allow clockwise rotation 803 of the third link component 305. The third link component 305 rotates in clockwise direction 803 to bring the vehicle hood in downward direction 802 to absorb the head impact force of pedestrian.
[0037] The present multi joint hinge assembly is assembled at the ends of the vehicle hood to absorb the head impact force during collision. The present multi hinge assembly reduces Head Injury Criteria (HIC) score at the hood hinge region. The structure of the multi joint hinge assembly allow better energy absorbing capabilities during head impact at the hood hinge region. During the pedestrian head impact, the multi joint hinge assembly deforms in downward direction to absorb head impact force efficiently to provide better HIC values.
[0038] It is easy to manufacture and assemble the present multi joint hinge assembly in the existing vehicles. There is no requirement to change the current structure of the existing vehicles so there is no modification cost. The present multi joint hinge assembly can be implemented in the existing vehicle to make the existing vehicles safe for pedestrian. The present multi joint hinge assembly in the vehicle hood assembly meets the required HIC score for complying pedestrian safety regulations.
[0039] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possibleIn addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.
[0040] 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.

Claims:We claim:
1. A multi joint hinge assembly (300) for vehicle hood to absorb pedestrian head impact force during collision of pedestrian with vehicle front, the multi joint hinge assembly (300) comprising:
a hinge arm (301) mounted to the vehicle hood;
a base component (302) mounted on vehicle body;
a first link component (303) provided in between the hinge arm (301) and the base component (302), wherein the first link component (303) connected with the base component (302) via first rotatable pivot joint (306) via first pin (306a) from one end and with the hinge arm (301) via second pin (307) movable in a horizontal first slot (311) provided on the hinge arm (301);
a second link component (304) connected with the hinge arm (301) via second rotatable pivot joint (308) with third pin (308a) from one end and;
the second link component (304) connected with the third link component (305) via a fourth pin (309) which is guided by a predefined second slot (312) on the third link component (305);
a third link component (305) connected with the base component (305) via fourth rotatable pivot joint (310) with fifth pin (310a); and
wherein the vehicle hood open and close about rotational axis of the second rotatable pivot joint (308).

2. The multi joint hinge assembly (300) as claimed in claim 1, wherein the second link component (304) locked with the third link component (305) via a first shear pin (313).

3. The multi joint hinge assembly (300) as claimed in claim 1, wherein the third link component (305) locked with the base component (302) via a second shear pin (314).
4. The multi joint hinge assembly (300) as claimed in claim 1, wherein the first shear pin (313) breaks when pedestrian head impact force is greater than threshold impact bearing force, the breaking of the first shear pin (313) allows movement of the second link component (304) in predefined motion in the predefined second slot (312) via the fourth pin (309), and upon breaking of the first shear pin (313) and movement of the second link component (304) in the predefined second slot (312) the vehicle hood moves in downward direction to absorb the pedestrian head impact force.

5. The multi joint hinge assembly (300) as claimed in claim 4, wherein the breaking of the first shear pin (313) results in free movement of first link component (303) in the horizontal first slot (311) via second pin (307) of the first link component (303).

6. The multi joint hinge assembly (300) as claimed in claim 4, wherein the third pin (308a) rotates and angle between the hinge arm (301) and the second link component (304) decreases or increases which brings the vehicle hood downward.

7. The multi joint hinge assembly (300) as claimed in claim 3, wherein the second shear pin (314) breaks when the fourth pin (309) of the second link component (304) which moves in the predefined second slot (312) reaches other end of the predefined second slot (312) and the pedestrian head impact force is continuous;

wherein breaking of the second shear pin (314) allows rotation of the third link component (305) about the fourth rotatable pivot joint (310) with the help of the fifth pin (310a) in clockwise direction which helps in lowering down the vehicle hood to absorb the pedestrian head impact force.

8. The multi joint hinge assembly (300) as claimed in claim 4, wherein the breaking of the first shear pin (313) and the second shear pin (314), based on the pedestrian head impact force, one after another makes the multi joint hinge assembly (300) capable of effectively dissipating the pedestrian head impact energy in a controlled manner.

9. The multi joint hinge assembly (300) as claimed in claim 1, wherein the second rotatable pivot joint (308), during the pedestrian head impact, moves in anticlockwise direction along with the hinge arm (301) in respect of the second link component (304), wherein the fourth rotatable pivot joint (310) and the first rotatable pivot joint (306), during the pedestrian head impact, moves in clockwise direction along the first pin (306a) and the fifth pin (310a) respectively, in respect of the base component (302).

10. The multi joint hinge assembly (300) as claimed in claim 1, wherein the threshold force of the pedestrian head impact depends on the vehicle and vehicle hood structure and dimensions. ,