Hood design-Week 2

1.Hood: -

The hood is an opening body panel that covers the engine, in a front engine vehicle. The hood is also considered as another type of a door in a vehicle, as it consists of the outer and inner panel. The inner panel provides strength, while the outer panel functions as the metal cover. The main components of a hood assembly are, outer and inner panels of hood, Striker, hinge assembly. The striker can be used as a latch and it can be useful to lock the outer panel of the hood and it also uses for to reduce the NVH. The hinges are used for the opening and closing the hood assembly by using the hood stays.

2. Mastic data: -

The gap between outward and inner panel should be 5mm and this gap will be filled by the mastic points. This gap is called mastic data.

3. Latch Trajectory: -

It means “Hinge axis” of the hood. The path followed by the hood about hinge axis while opening and closing it is called trajectory and it will be in the circular shape.

4. Emboss: -

The pattern of a car hood and it can be used for to the relief against the smooth surface. And this embossed effect is got through the stamping method.

5. Manufacturing Processes: -

5.1 Deep drawing: -

A metal forming technique called deep drawing, is used to shape flat sheet metal into hollow, cylindrical, or box-shaped parts. This covers the steps involved in creating sheet metal, such as the metal preparation, blanking, punching, drawing, and final shaping of the product.

5.2 Hemming: -

Hemming is a technique used to provide a smooth, rounded finish by folding the edge of sheet metal back upon itself. And in order to make the desired product, this hemming process includes a number of phases, including material preparation, cutting, bending, flattening, and finishing.

6. Design parameters of a hood: -

The hood assembly of a passenger car involves some design parameters while design the hood to get the smooth flow while in the manufacturing process and also to get the desired shape of the product. The most important design parameters while design a hood are,

1. Opening angle (< 35 mm curvature)

2. Type of the hood stay (Support rod/Gas stay)

3. NVH (Noise and Vibration Harshness)

4. Reinforcement latch and striker

5. Hinges reinforcement

6. Stiffener pad

7. Technologies like hemming, gluing, mastic

6.1 Design considerations of a hood: -

1. Crash regulations

2.Pedestration safety

3. Functional requirements

4. Mastic data

5. Manufacturing feasibility

Note: -

1. The design files and detailed report are placed in the "zip "file for your reference.

2. STEP file was not added due, to option not avilable in my NX CAD version.