Hood design-Week 2

REPORT :

HOOD- it is a hinged cover of engine of motor vehicles that allows acess to engine compartment, trunk, rear engine or mid engine vehicles. This part is made up of same material material as rest of the body part. the materials can be steel, aluminiun, fibre glass or carbon fibre.

Hood consists of- outer panel, inner panel, latcher, hinge assembly.

in order to design the hood, the engineers need to take few parametrs into consideration such as

pedastrian safety, occupant safety, styling, manufacturibility and

important points to be considered while designing hood is open angle of hood, NVH- noise, vibrations , harshness and wrap around distance. etc.

Sheet metal operations:

emboss: is a stamping processfor producing raised or sunken designs or releif in sheet metal. It can be made by matched male and female roller dies, or by passing sheet or strip metal between rolls of desired pateern. The material suitable for embossing is aluminiun, brass, card stock, copper, glavanized steel etc.

Deep drawing: Deep drawing is a sheet metal forming process in which a sheet metal blank is radically drawn into forming die by mechanical action of a punch. It is a shape transformation process process with material retention. the process is considered deep drawing when the depth of the drawn part exceeds its diameter.

Hemming:Hemming and seaming are two similar metal working process in which a sheet metal edge is rolled flush to itself, while seam joins the edges of two materials. Hems are commonly used to reinforce an edge, hide burrs and rough adges, improve apperance. Hemming is a metal forming process in which sheets are joined by bending it to 180 degree.

Mastic points: Mastic sealants are used to stick the inner surface of outer panel and inner panel. it behaves like elastic component that behave like rubber. Its is applied between the inner and outer panels at specified spots.

PARTS

outer panel: outer panel are the aesthetic elements of a car. the style, position and size of the hood should satisfy the safety norms. So while designing the hood we should give importance to pedisterian safety.The outer panel is attached to inner panel by hemming and provide mastic sealants between inner panel and outer panel to reduce vibration. the picture is shared. The thickness is 0.75mm.

inner panel Inner panel is the right that gives strength and rigidity to the outer panel.The master section represents the initial emboss shape and size, thickness is 0.75mm

Latch and hinge: Latch trajectory is given by the circle drawn from the hinge axis point. Hinge axis point is the centre point of the hinge axis. First, we can fix either the latch or the hinge. If we have fixed the hinge position then we should plot the Trajectory circle for the latch. For proper mating condition the striker axis through the tip of the striker should be tangential to the latch trajectory.

the tolerance in the resulted result is shown in the pictures.