Hood design-Week 2

WHAT IS HOOD?

Hood is the opening body panel which covers the engine assembly. Hood is also considered  another type of door in vehicle it consist of inner panel and outer panel. Inner panel provides more strength while outer panel performing as a metal cover.

DESIGN REQUIREMENT OF HOOD DESIGN?

• OPENING ANGLE

The opening angle varies from region to region, opening angle for hood decided by average height of people’s lives in that particular region. The hood opening angle changes with help of predefined length of the rod, if it varies the length then opening angle also varied. The main agenda is when open the hood the striker should not hit the person head.

DESIGN CONSIDERATION OF SUPPORT ROD

• The important design factor for support rod is it doesn’t straight we should develop our support rod some deflection because if support rod in straight condition it doesn’t withstand the load after certain time period it will cause breakage and cracks on the support rod. The support rod deflection should not exceed 35mm.
• Support rod should always mount opposite side of battery.
• Minimum gap between support rod and other hinges and engine components is 10-15 mm.

There are two types of components for open the hood

• SUPPORT ROD

This device support the engine hood of a motor vehicle in open position by mean of rod.

• GAS STAY

This device working function same as rod but it mechanism is different.it is run with help of actuator which is activated by using gas.

• REINFORCEMENT

Whenever add weight to the material at the time material get loss strength in locally. For example creating emboss is add weight of material, at the give reinforcement then it will compensate the loss of strength.

In hood we are going to develop different kind of emboss. They are STRIKER&HINGE emboss.

• MASTIC SEAL

It is placed between inner and outer panel. It will help to attained good NVH for the vehicle.

NVH mean is noise vibration and hardness.

Mastic seal is improving the strength of locally between 80mm diameter.

Distance between outer panel and mastic seal is around 5mm.

Outer and inner panel hold by using kind of rubber. When outer panel came out from the furnace in high temp at the time mount inner and outer panel by using the rubber. Because of heat the rubber is hardened.  

• DEEP DRAWING PROCESS

In this process the sheet metal blank space turn to radial projection, because it will help for during the stamping process. RADIUS IS 15MM in every blank space.

On the blank space we should give 15mm radius clearance for perfect stamping during production.

• EMBOSS

Whenever the collision happen without the emboss it cause huge impact to the human inside the vehicle, The impact force doesn’t deviated.

As a design engineer priority is first dissipate the force as early as possible, when developing the embosses it will dissipate the force. Emboss structure is developed like a triangle and circle like different shapes. Because of the different shapes the impact force is get arrested.

Distance between each emboss is 6-8mm

Fillet radius is 3+thickness of the component.

• LATCH AND HINGE.

The definition of a latch is a hook, bar or other mechanism that causes a door or to close and stay closed.

This will hold the hood with HINGE EMBOSS body.

The hinge emboss surface should be proper plane, it doesn’t deflected. Then only mount latch over the hinge emboss.

• LATCH TRAJECTORY

This is important design consideration while develop the hood, this will help striker to lock in the Locking system.

Radius of trajectory from hinge axis center point to striker center point.

• HEMMING PROCESS

This hemming process is a manufacturing process done by roller for develop the aesthetic surface.

Remove the sharp corner by using hemming process.

STRESS RELIEF

In every corner done some stress relief process, because the roller doesn’t perform over the corner at the time we give some relief which mean removal of unshaped materials.