Hood design-Week 2
AIM :
To Design the hood of the car using Hood Outer Panel, Inner Panel and the necessary reinforcements by following the Master Section mentioned with the Design parameters.
INTRODUCTION:
Hood is main component of a car at the front portion. It is used to decorate the car and also gives a luxurious look of the car. The shape of the bonnet is made aerodynamic in order to minimize the air effect.The front hood has been cut from general assembly shapes of an electric prototype vehicle.
The design of this it was done using NX CAD software program using surface design and composite design modules. It was performed behind it based on the shape of the external surface of the model. The hood are some fixing points and reinforcement zone for its hardening, this element was modelled in according with similar element from actual cars.
In UK terminology, a hood refers to a fabric covering over the passenger compartment of the car (known as the “roof” or “top” in the US). For many motor vehicles built in the 1930s and 1940s, the resemblance to an actual hood is clear when it is opened and viewed from the front; in modern vehicles, it still serves the same purpose, but no longer resembles head covering.
The Hood should be designed with a light weight for the pedestrain saftey as the person hit to hood there should be minimal harm to the person.
Another important criteria for the hood design is the protection of the occupants inside the car during front collision. The design of the hood should be in a such a way that the during the collision, the force should travel in the upward direction through the embosses & directed towards the body of car. Thus protecting the occupants inside.
design input for the input panel is given below:
Following parts are using in hood assembly for this report,
- Hood outer panel
- Hood inner panel
- Hinge assembly
- Striker assembly
Hood thickness:
Outer panel thickness= 0.75 mm
Inner panel thickness= 0.75 mm
Reinforcement thickness= 1.5 mm
INNER PANEL:
In the inner panel only we can research & implement the safety of pedestrians & as well as the driver. In this panel only we can attach the reinforcement, embossed, mastic points etc.
It is an object of the present invention to provide a hood inner panel capable of reduction of a reaction force of the hood inner panel even if a level of deformation of a hood of a vehicle increases, & ensuring a sufficient energy absorption capacity.
OUTER PANEL:
We can also call it as cover of inner panel. It is the part, which gives luxurious look to the hood or bonnet. Outer & inner panel can not join by any welding process like spot welding or rivet, which spoil the outer look of a car.
HINGE ASSEMBLY:
Hinge is a component that fixes the hood to the fenders of the car. The latch must be fixed perpendicular to the hinge axis so that the hood opens or closes properly.
STRIKER ASSEMBLY:
Latch & striker is used for locking the hood with the car. It is usually placed on the space provided on the inner panel.
HEMMING:
Hemming is a sheet metal forming process in which sheets are joined by bending it usually to 180 degree. Automotive body panels & parts such as deck-lids, trunk-lids, doors, hoods & tailgates are formed by hemming processes.
Roll hemming is carried out incrementally with a hemming roller. An industrial robot guides the hemming roller & forms the flange. Roll hemming operation can also be divided into several pre-hemming & final hemming process steps.
Coventional die hemming is suitable for mass production. In die hemming, the flange is folded over the entire length with a hemming tool. Normally the actual hemming is a result of a forming operation in which the flange is formed with a hemming tool after the drawing & trimming operations have been completed.
While doing the hemming process a relief angle is formed as a product of hemming when attaining at the corner of the sheet.
EMBOSS:
The sheet metal embossing operation is commonly accomplished with a combination of heat & pressure on the sheet metal, depending on what type of embossing is required.A sheet metal is drawn through the male & female roller dies, producing a pattern or design on the sheet metal. Depending on the roller dies used, different patterns can be produced on the sheet metal.
DEEP DRAWING:
Deep drawing is a manufacturing process that is used extensively in the forming of sheet metal into a cup or box-like structures. Pots & pans for cooking, containers, sinks, automobile parts, such as panel & gas tanks, are among a few of the items manufactured by sheet metal deep drawing.A deep drawing of sheet metal is performed with a punch and die. The punch is the desired shape of the base of the part, once drawn. The die cavity matches the punch and is a little wider to allow for its passage, as well as clearance. For many calculations, the sheet metal thickness is assumed to remain constant. There are changes in thickness in certain areas, due to force involved.
LATCH TRAJECTORY:
While opening or closing the hood, the latch must be perfectly aligned to the fixing or striker point. For that, the latches trajectory must be perpendicular to the hinge axis.
THE FINAL ASSEMBLY OF HOOD:
CONCLUSION:
We have designed a hood that falls under the rules & regulations of the manufacturer's standards.
CAD DATA:
https://drive.google.com/drive/folders/1ihBnuV1DnzDgw2Qvh1J4lCmca8fhSTwL?usp=sharing