DESC:Field of the invention

The present invention relates to a support mechanism for a vehicle bonnet and more particularly, to a hinge mechanism for the bonnet of vehicles.

Background of the invention

An engine compartment of automotive vehicles is covered by a hood/bonnet/lid. The bonnet when opened/lifted allows access to the engine compartment and under bonnet parts for service purpose. Generally, the bonnet is opened by mechanical or hydraulic mechanisms that is either manually or with a gas strut. During the hydraulic opening operation, the gas strut rotates along an axis of a hinge which is a mechanical component fitted to a vehicle body. Manual lifting of the heavy bonnet requires more effort due to the weight of the bonnet. The efforts (in kilogram force,
kgf) required for lifting the bonnet in conventional design of hinges are as provided in the table below:

Sr. No Bonnet weight range Initial opening force required (kgf) Force required at full open condition (kgf)
1 13-14 kg 10.0 - 10.5 10.5 - 11.0
2 14-15 kg 8.5 - 9.0 10.5 - 11.0
3 19-20 kg 12.5 - 13.0 13.5 - 14.0

United States Patent number 6618904 discloses a torsion spring and a strut cylinder. The torsion spring opens a lid or hood by exerting a pop-up effect thereon. The strut cylinder acts as a dampening mechanism for slowing down the movement of torsion spring. However, the invention discloses a complicated mechanism that uses more number of parts. Further, the spring and the strut cylinder are directly connected to linkages such that failure of even one part affects the lid opening or closing operations.

Another United States Patent number 7546663 discloses a wounded helical coil spring to open lid by its own. The mechanism includes a coil spring acting like a torsion spring. One end of the coil spring is fixed and other end has wounded coil tension in a closed condition of a hood or lid. The coil spring used is self sufficient to lift and keep the bonnet open. However, the coil spring is packaged in transverse direction of the vehicle which needs more packaging space. Further, the coil spring being heavier requires more effort to close the hood and results in jerky opening of the hood. Moreover, absence of a bonnet stay rod in the mechanism increases the chances of an accident if spring fails.

Yet another United States Patent number 4991675 teaches use of compression springs to tilt a hood especially of heavy trucks/tractors where more engine access is required for service. In this mechanism, a solid rod is placed inside the compression springs to control travel of the hood. However, this mechanism is not suitable for vehicles wherein the hood is opened towards a wind shield due to the constraint of more space for its operation and therefore it will foul with the windshield.

Accordingly, there is a need for a hinge mechanism for a bonnet of a vehicle that overcomes the above mentioned drawbacks of the prior art.

Object of the invention

An object of the present invention is to provide a cost effective solution to reduce lifting effort during a bonnet opening operation.

Summary of the invention

Accordingly, the present invention provides a hinge mechanism for a bonnet of a vehicle. The hinge mechanism comprises a lower hinge member, an upper hinge member, at least two hinge links and a tension spring.

The lower hinge member is fixed to a body panel of the vehicle. The lower hinge member includes link stoppers configured thereon and a crash lock welded thereon. The crash lock includes a notch configured thereon.

The upper hinge member is fixed on a bonnet panel. The upper hinge member is capable of being moved / lifted to any of an intermediate open condition, a complete open condition and a closed condition with respect to the lower hinge member. The upper hinge member includes a longitudinal slot configured thereon. The longitudinal slot engages the notch of the crash lock thereon in the closed condition of the upper hinge member.

The at least two hinge links connect the upper hinge member and the lower hinge member. The at least two hinge links are connected between the upper hinge member and the lower hinge member through a plurality of rivets.

The tension spring is integrated between the upper hinge member and the lower hinge member. The tension spring through ends thereof is locked inside holes on the hinge members. The tension spring is capable of undergoing any of a compressed mode and a tension mode.
An initial opening of the upper hinge member to the intermediate open condition by a user causes compression of the tension spring resulting in complete open condition of the upper hinge member with respect to the lower hinge member thereby assisting in opening of the bonnet with reduced user efforts.

Brief description of the drawings

Other features as well as the advantages of the invention will be clear from the following description.

In the appended drawings:

Figure 1 shows a perspective view of a hinge mechanism for a bonnet of a vehicle, in accordance with present invention;

Figure 2a shows another perspective view of the hinge mechanism of figure 1 in an open condition;

Figure 2b shows yet another perspective view of the hinge mechanism of figure 1 in a closed condition;

Figure 3 shows a perspective view of a tension spring of the hinge mechanism of figure 1 in compressed and tension modes;

Figure 4 shows a side perspective view of the hinge mechanism of figure 1; and

Figure 5 shows a top perspective view of the hinge mechanism of figure 1.

Detailed description of the invention

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.

The present invention provides a hinge mechanism for a bonnet of a vehicle. The hinge mechanism is a cost effective spring assisted hinge mechanism that reduces the lifting effort during a bonnet opening operation.

This present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring to figures 1 to 3, in one aspect, a hinge mechanism (100) for a hood / bonnet (not numbered) of a vehicle (not shown) in accordance with the present invention is shown. The hinge mechanism (100) is positioned on both sides (not shown) of a vehicle body (not numbered) inside an engine compartment (not numbered) and under the bonnet. The hinge mechanism (100) comprises a lower hinge member (30), an upper hinge member (40), at least two hinge links (50, 60) and a tension spring (70). In an embodiment, the lower hinge member (30), the upper hinge member (40) and the at least two hinge links (50, 60) are made from a hot rolled steel sheet of grade IS-1079 EDD (Extra Deep Draw).

The lower hinge member (30) is fixed to a body panel (not numbered) of the vehicle. In an embodiment, the lower hinge member (30) is bolted on a bracket A-pillar lower (not shown) on the body panel on either side (not numbered) thereof. The lower hinge member (30) includes link stoppers (25) configured thereon and a crash lock (15) welded thereon by a weld joint (14) as shown in figure 2a. The crash lock (15) includes a notch (not numbered) configured thereon. The lower hinge member (30) on one end (not numbered) is connected to the upper hinge member (40).

The upper hinge member (40) is a spring assisted hood hinge fixed on a bonnet panel (110) of the vehicle. In an embodiment, the upper hinge member (40) is bolted on the bonnet panel (110). The upper hinge member (40) includes a first end (not numbered) and a second end (not numbered). The first end is connected to one end of the lower hinge member (30). The second end includes a longitudinal slot (35) configured thereon. The second end is free to be moved with respect to another end (not numbered) of the lower hinge member (30). When the second end of the upper hinge member (40) is moved down to the closed condition, the notch of the crash lock (15) thereon gets engaged inside the longitudinal slot (35) of the second end of the upper hinge member (40). This engagement helps in keeping the bonnet in a closed condition.

Thus, the upper hinge member (40) is capable of being moved / lifted to any of an intermediate open condition, a complete open condition and a closed condition with respect to the lower hinge member (30). The upper hinge member (40) in the complete open condition with respect to the lower hinge member (30) results in opening of the bonnet to provide access to the engine compartment and other components (not shown) of the vehicle for maintenance and repair purposes.

The at least two hinge links (50, 60) (herein after ‘the links (50, 60) are connected between the lower hinge member (30) and the upper hinge member (40) as shown in figure 4. The purpose of the links (50, 60) is to connect the hinge members (30, 40) to each other. In an embodiment, ends (not numbered) of the links (50, 60) are connected to the upper hinge member (40) and the lower hinge member (30) through a plurality of rivets (45). The movement of the link (60) in the open condition of the upper hinge member (40) and the movement of the link (50) in the closed condition of the upper hinge member (40) are restricted by the link stoppers (25).

The tension spring (70) (hereinafter referred as “the spring (70)”) is mounted / integrated between the lower hinge member (30) and the upper hinge member (40). Specifically, the spring (70) through ends (not numbered) thereof is locked in holes (12) on the hinge members (30, 40) as shown in figure 5. The spring (70) is capable of undergoing any of a compressed / idle mode and a tension / stretched mode as shown in figure 3. Specifically, the spring (70) is in the compressed mode when the upper hinge member (40) is in the open condition. The spring (70) because of its properties maintains the bonnet in the open condition. Although, the hinge mechanism (100) is designed in such way to withstand the load of the bonnet in the open condition, but for safety purpose, a stay rod (not shown) of the vehicles is optionally used. The spring (70) is in the tension mode when the upper hinge member (40) is in the closed condition.

Referring again to figures 1 to 3, in another aspect, working of the hinge mechanism (100) for opening and closing operations of the bonnet in accordance with the present invention is described.

Bonnet opening operation: The upper hinge member (40) is moved / lifted to the intermediate open condition by a user. The initial / partial opening of the upper hinge member (40) causes compression of the spring (70). The spring (70) in the compressed mode biases the upper hinge member (40) to the complete open condition with respect to the lower hinge member (30) thereby assisting in opening of the bonnet.

The spring (70) assists to lift the bonnet as well as reduce the lifting effort during the bonnet opening operation. In an embodiment, the efforts / force required for lifting the bonnet weighing between 15-20 kgs with the spring assisted hinge for initial opening to the intermediate open condition is between 8.5 - 9.0 kgf and for complete opening to the complete open condition is between 10.5 - 11.0 kgf. Thus, the hinge mechanism (100) requires 3.0 - 3.5 kgf lesser force to lift the bonnet as compared to the conventional hinges.

Bonnet closing operation: The upper hinge member (40) is moved, by the user, to the closed condition with respect to the lower hinge member (30) such that the notch on the crash lock (15) gets engaged with the longitudinal slot (35) on the second end of the upper hinge member (40) and the spring (70) comes to the tension mode to result in the closing of the bonnet.

Advantages of the invention

1. The hinge mechanism (100) provides cost effective solution to the problems in the art as compared to the prior art hydraulic system.
2. The hinge mechanism (100) is packaged within the existing designs of the vehicle body or in any of the related components in less packaging space without requiring modification of the design of the vehicle body.
3. The spring (70) of the hinge mechanism (100) reduces the lifting effort of the user.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.

,CLAIMS:1. A hinge mechanism (100) for a bonnet of a vehicle, the hinge mechanism
(100) comprising:
• a lower hinge member (30) fixed to a body panel of the vehicle, the lower
hinge member (30) having link stoppers (25) configured thereon and a crash lock (15) welded thereon, the crash lock (15) includes a notch configured thereon;
• an upper hinge member (40) fixed on a bonnet panel (110), the upper
hinge member (40) capable of being moved / lifted to any of an intermediate open condition, a complete open condition and a closed condition with respect to the lower hinge member (30);
• at least two hinge links (50, 60) connected between the upper hinge
member (40) and the lower hinge member (30); and
• a tension spring (70) integrated between the upper hinge member (40)
and the lower hinge member (30), the tension spring (70) being capable of undergoing any of a compressed mode and a tension mode,
wherein, an initial opening of the upper hinge member (40) to the intermediate open condition by a user causes compression of the tension spring (70) resulting in complete open condition of the upper hinge member (40) with respect to the lower hinge member (30) thereby assisting in opening of the bonnet with reduced user efforts.

2. The hinge mechanism (100) as claimed in claim 1, wherein the at least two
hinge links (50, 60) are connected to the upper hinge member (40) and the lower hinge member (30) through a plurality of rivets (45).

3. The hinge mechanism (100) as claimed in claim 1, wherein the tension spring
(70) through ends thereof is locked inside holes (12) on the hinge members (30, 40).
4. The hinge mechanism (100) as claimed in claim 1, wherein the upper hinge
member (40) includes a longitudinal slot (35) configured thereon for engaging the notch of the crash lock (15) thereon in the closed condition of the upper hinge member (40).