Hood design-Week 2

HOOD ASSEMBLY DESIGN

The hood or bonnet is the hinged cover over the engine of motor vehicles Hoods can open to allow access to the engine compartment, or trunk on rear-engine and some mid-engine vehicles for maintenance and repair. It is used to decorate the car and add a luxurious look. The shape of the Hood is made aerodynamic in order to minimize the air effect

Hood is consist of

Hood outer panel

1. Hood inner panel
2. Hinge
3. Striker
4. Hood Outer Panel

Outer panels are the aesthetic elements of a car. It is the styling team who provides the skin for the outer panel. The shape, position and size of the hood should satisfy the safety norms. it is important for reduce Aerodynamics force . For our design we have consider outer panel length for considering Hemming and relief for connecting Inner panel.

1. Hood Inner Panel

Inner panel is the part that gives strength and rigidity to the outer panel. It has expose for considering pedestrian safety at the time of collision (Accident). it does not harmful for humans head when it is hitting so that we need to make cutout in inner panel also it does not affect hood strength. Inner panel having proper space for mastic and Hinge assembly expose, Striker assembly expose it will help to make final hood assembly.

1. Mastic data

Mastic seals are used as a bond between the inner and outer panels.it is also used to improve the stiffness of the area. It plays a vital role which is reducing the NVH, the gap between the inner and outer panel is 1.7 mm. Mastic seal will occupy the 1.7mm gap.

2. Hinge

Hinge is used to hold and rotate the Hood while open and Close. Our Hood is rotate in Hinge axis only So we have ensure correct place for mounting and give appropriate Constrain with Hood.

3. Striker

A system for releasing and lifting an automobile hood includes a sensor located proximate a front location of an automobile that detects impact with an object. Also included is a hood having a striker pin operably connected to the hood for engaging a rotatable latch, wherein such engagement places the hood in the secured position. Further included is a releasing mechanism operably connected to one of the striker and the latch for lifting a front region of the hood in response to a signal from the sensor.

In Design while mounting Striker we have to provide proper expose for mounting and need to provide constraint with latch Axis and trajectory line from hinge axis with inner panel and made proper law extension in inner panel.

Manufacturing Process for Hood Assembly

For Sheet metal Operation Deep drawing and hemming is mainly used for Hood.

1. Deep Drawing

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

Here Inner Panel is manufacturing using below process. The tie consist of hinge assembly emboss, Striker emboss, various Steps and others. While designing we are given 7 degree as Draft angle .

2. Hemming Process

Hemming is a forming operation in which the edges of the sheet are folded or folded over another part in order to achieve a tight fit. Normally hemming operations are used to connect parts together, to improve the appearance of a part and to reinforce part edges.

Here we used for joining Hood Outer panel and Inner Panel

Hemming and relief

Using Above process i have done Hood assembly design Using UG-NX.

, here we see different types of views in Hood Design

CONCLUSION

Understand how to use the NX CAD software for design Surface modelling understand how to design hood and what is the purpose of hood. Understand the Sheet metal manufacturing process and impact of Hood design. Understand the need to the safety requirement to be needed while designing the hood