Project 1 Hood

Hood

The car's hood consists of an inner and an outer panel. The inner panel provides strength, while the outer panel is just a metal cover.

The underside of the hood is often covered with a sound-absorbing material.

• Hood are typically made out of steel or aluminum, although aftermarket manufacturers may manufacture hoods out of fiberglass,

carbon fiber, or dry carbon.

• The hood or bonnet is the hinged cover over the engine of motor vehicles that allows access to the engine compartment for

maintenance and repair. On passenger cars, a hood may be held down by a concealed latch.

• Some high performance cars have 'hood scoops' which channel outside air directly to the air filter, which gives improved performance

and efficiency

• It is hinged thin sheet which covers and protects the main parts of car like engine. Its main function is to direct access to the engine,

bettry and other crucial parts of the cars for repair and maintenance and to protect these parts from direct sunlight and dust. It also

gives good looks and help to design car aerodynamically stable.

Regulations have come into effect in recent years that place a lingit on the severity of pedestrian head injury when struck by a motor

vehicle. This is leading to more advanced hood designs.

• The hood release is a small lever, which is usually mounted under the dash. It is connected to the hood latch by a cable. The hood

latch has a safety feature, which requires a second latch to be released before the hood will open. This is to prevent accidental

opening while driving.

DATA:

Inner hood has been designed by following the master data:-

Hood thickness:-

• Outer panel thickness:- 0.75mm
• Inner panel thickness:- 0.75mm
• Reinforcement thickness:- 1.5mm

.

DESIGN:-

Inner panel:

The inner panel supports the outer panel. it consists of embosses & holes. Embosses provide stiffness as well as it dissipates energy towards reinforcement.

Outer panel:-

Outer panel us nothing but a outside cover.

For engine and it is used to make a car look good.

Hemming -

• The outer panel & Inner panel can't join by any welding process if we did it will leave a spot on the outer panel and it will spoil the

look of a car. so, to join inner and outer closure panels together we use the Hemming process.

• It is the process of bending/folding the flange of the outer panel over the inner one.
• The flange of the outer panel is bent over the inner panel in progressive steps by means of the roller hemming head.

Corner Relief:-

There are many types of Hemming process but in Hoods Roller hemming is used. In this process the roller will be rolling over the edges of

the Outer panel to close it with the inner

panel. These roller will be rolling over 2-3 time for perfect closing. so, the certain

force is being used by rollers to all the corners but there are

some areas where the roller cannot tighten the part properly so thats why we give some relief to the corners.

Mastic sealant:-

The Mastic sealant or mastic points is a elastic compound that behaves like a rubber. it is applied between Hood's outer panel and inner

panel. it have an influence area of about 80mm.

Reinforcements -

Reinforcements are used to provide more strength to the assembly.

1. Latch & striker
2. Hinge

LATCH & STRIKER:-

Latch & striker is used for locking the hood with the car. it's usually placed on the space provided on the inner panel.

HINGE-

Hinges are used to connect the hood & cowl panel of an automobile. it enable the opening & closing operation of the hood. the hinge

should be made strong enough to to handle the weight of the hood and also to handle the force action on it during the collision.

Position of Hinge & Striker:-

The hinges should be usually placed on both sides of the hood in such a way that the strike fits exactly into the hole provided.

To ensure this the followning conditions are follow:-

1. Both the hinges should be on the same axis.
2. The centre of the striker's circular trajectory should be always perpendicular to the hinge axis.

EMBOSS:-

Embosses are the projections made on sheet metal using deep drawing techniques. the operation is carried out the mostly for the purpose of stiffening flat surface and design in the inner panel. the major function of embossing is to dissipate the force acting on the hood during the collision of the car toward the hinges as early as possible. this helps to reduce the impact of the force on the passenger sitting inside.