DESIGN OF HOOD

INTROUDCTION OF HOOD AND BONNET:

The hood (North american english) or bonnet (Commonwealth english excluding Canada) is the hinged cover over the engine of motor vehicles that allows access to the engine compartment, or trunk (boot in Commonwealth english) on rear-engine and some mid-engine vehicles) for maintenance and repair.

Function of hood:

• Protects the parts of the engine compartment from external damage
• Serves as cover for engine compartment
• Pedestrian safety is ensured
• Gives an aesthetic look to the car
• Helps in reducing the frontal crash

Hood thickness information:

Outer panel thickess = 0.75mm

Inner panel thickess = 0.75mm

Reinforcement thickess = 1.5mm

work bench:

• Sketcher
• Part design
• Generative shape design
• Assembly design

Outer panel whith the Hem:

This is an outer panel of the hood this bend inwards which helps this outer panel to joint the inner panel. This process is called hemming.

Relief at corners are provided to aviod red zone as during the process of hemming. When the rollers apply force on the outer panel to link the inner panel so at corners force applied by rollers should not disturb the shape of the outer panel and inner panel configuration.

If corners portions are disturbed then zones are called as red zones. To avoid red zones, relaxation at corners are allowed.

Design the embossing in inner panel:

Useing commend: Offset,Boundare, Fillet,Parallel,Extrude,Split,Multi-sections surface, Curve smooth, Sweep, Trim,Project,Thicksurface.

The embossing is the process of producing reliefs to the sheetmetal by giving designs in the sheetmetal.The embossings is used to provide support to the sheetmetal.

The embossings provided also make a passage for the force when acted upon the hood which dissipates the force so the passenger gets affected by a mimimum force. Its main purpose is to dissipate the energy

While designing the embossing different types of designs are used to make the passage and also it deepens the metal, so inorder to reduce the weight some parts are also removed in way to reduce the weight and at the same time whitout affecting the strenth of the material.

In this inner panel, embossing are provided in such a way that the force acted upon the hood gets dissipated along the passages provided in the hood, which reduces a considerable percentage of force which acts on the passenger so, the passenger gets a minimum damage.

Latch Reinforcement is of 1.5mm

This is latch reinforcement which is made by extruding the face of latch on inner panel. Reinforcements are made of flat plates of thickness 1.5mm.

This is hinge reinforcement which is made by extruding the face of latch on innerpanel reinforcement are made of flat plates of thickness 1.5mm

Assembly:

Hemming process to join the outer panel and inner panel:

To do the hemming process the outer panel is twisted and bent around the inner panel using rollers.

The bent shape is improved by passing different rollers till a perfect curve bent is formed. By doing this process spot welding is avoided.

This is a special technique used in preparetion of hood to join the outer panel and inner panel.

They are two types of Hemming

• Conventional die hemming
• Roll hemming

Cut section of view:

Mastic points:

It helps in improving NVH(Noise Vibration Hardness)

It tendes to improve the strength of panel locally up to 80mm in diameter.

Mastic sealants used in between the outer and inner panel.

These are like paste kept in between outer and inner panel afther coming out of the furnace it gets hardened.

Mastic sealants are preferred for joining as spot welding can make styling surface look worse. To keep the aesthetic look of car hemming and glueing mastic sealant are used.

Positioning of Hinge and Latch striker:

The position of the latch striker depends upon the position of the striker. The position of the striker depends upon distance between the centre of the hood and the hinge centre.

To determine whether the striker would hit the bottom,we have to create a trajectory whit radius being the distance between the hinge centre and midpoint the panel.The centre being the midpoint of the panel.

The trajectory is created and striker midpoint be perpendicular to the trajectory.

Here is the link to access my HOOD design project:

https://drive.google.com/drive/folders/1FT3LUb5nCO9wCRmvveVXa_AlSY-hYztu?usp=sharing