Design of Hood

                              Design of car HOOD

What is HOOD or Bonnet?

       Hood is also called as bonnet. It is the main componenet of front portion. The shape of bonnet is made aerodynamic in order to minimize the air resistence. It is used to access the parts like radiator,engine and many parts. Hood or bonnet in open position by the support of support rod or gas stay. Support rod is like different curves and bend to made it more strong to support hood.

Master section for HOOD design

Design of outer panel with hemming

• Outer panel is nothing but a outer skin of inner panel.
• Otherwise called as a cover of inner panel.
• It is the part, which gives luxurious look to the hood or bonnet.
• Outer pannel and inner pannel cannot join by any welding process like spot welding or rivet, which spoil the outer look of a car.
• So the special method called hemming had been adapoted to join them.
• Thickness of outer panel vary from 0.65 to 0.75mm
• Here I provide front relief 200mm, rear relief 29mm and 6mm for hemming in side.

What is hemming

        Hemming is a technology used in automotive industry to join inner and outer panel closure together. It is the process of bending/folding the flange of the outer panel over inner panel. It may be done by following methods

• Press hemming
• Table top hemming
• Robot (roller hemming)

Design of inner panel with embosses

• Inner panel supports outer panel.
• It consists of different embosses and hole at different places.
• Embosses provide stiffness as well as dissipate energy towards hinges.
• To determine the most effective position of hole, the method of modal stiffness is employed.
• Thickness of inner panel vary from 0.65 to 0.75mm
• Here I made 2mm gap between outer and inner panel for mastic seal.

What is emboss?

       Embossing is an operation in which sheet metal is drawn to shallow depths with male and female dies. The operation is carried out mostly for the purpose of stiffening flat surface and design in inner panel.

       It is also made that, when the car crashed the force will be passed to cabin. If embosses are made, the forces are made to passed or divided through embosses to hinges. So the passangers inside the car will be in safe.

Development of all necessary reinforcement

         Hood reinforcement structure as provided to reduce impact in collisions to passangers. When latch and striker attached to the panel, the strength will be reduced in that area. In order to improve the strength in that area the reinforcement is added.

       I between outer and inner panel there will be stiffner pad is also added to avoid NVH ( Noise,Vibration,Hardness).

       Here am made a reinforcement of hinges 1.5mm and striker 1mm. It may be vary. 

Position of hinge and striker

         For positioning hinge and striker, we have to place hinge tentatively and take hinge axis point and place striker position from data taken from parent car or our own. Take a hinge axis point and striker point as radius and draw a circle. From a circle we conclude two points

• Whether a circle is trajectory of hood opening and closing.
• At this position striker is exactly perpendicular to the trajectory locally

Mastic data

        Mastic seal is a kind of hard rubber glue added between outer and inner panel of hood to join them at different points called mastic points locally around 80mm diameter. There should be minimum 2mm gap between outer and inner panel to make a constant joint.

Embosses and mastic postiton that I have develop in my design

        I made a traditional v-shaped embosses to provide stiffness to my hood design. It will surely dissipate force to end of hinges and safeguard the passengers inside the car.

       Mastic postion that I made on the different points on hole on embosses and others, which will cover almost all area between outer and inner panel. 

Here is the link of my Hood project

https://drive.google.com/file/d/1Qk29uY-_s3I8C9RJ_wEHRn-aHUTaUakr/view?usp=sharing