Hood design-Week 2

AIM

To create hood design and hood assembly by using nx.

HOOD

The hood is a opening panel that covers a engine in front engine vehicle.the hood is a also another type of door in vehicle that consists of outer and inner panel.the inner panel provide strength of outer panel functions.  a hood stay is on aparatus for on engine room car which can safely keep on engine hood in a open state even on external force is abrupty generate vibration wind and can facilate an opening and closing operation of engine hood.a car hood also called as bonnet in some countries.is the hinged cover over that resit over the engine bay of the front engine vehicle the car hood that protects engine and connected parts the elemets while provide easy acces of repairs and maintenance.

TYPES OF HOOD STAY

1.Support rod

2.Gas stay

1.SUPPORT ROD

support rod basically cylindrical rod it safely keep on engine hood in on open state even if external force on abruptly generated due to vibration and wind.and also support the hood when attending the problems and car maintenance situation.support rod fixed to car body when open the hood the rod is hinged to hood.so that hood movement is arrested.

2.GAS STAY

There are used to lift the car hood. its the purpose to give the lifting force to the hood.then it automatically open the car hood by means of gas pressure.one end connected to hood and other end connected to car body.a gas stay also refered as a gas spring that operate due to force extered by the compressed gas stored inside the cylinder.luxuxy carmakers provide a gas stay to lift the hood and hold it in place.it takes mimimal efforts to lift on otherwise heavy hood and lends upmarket to feel the car. 

 

WRAP AROUND DISTANCE

When a car hits on a pedestrian the whole human body wrap around the front shape of the car and head impacts the hood or windscreen.the distanct at which head impact the car from the ground is called wrap around distance.

SHEET METAL FORMING OPERATIONS

This is usually carried out with the materials at room temperature,typically done combination with blanking in a stamping die.press forming differ from bending because of more complex shapes and multi axis forming on the various steels.the process relies on the ductility of the material being pressed.the materials used in the process stainless steel,aluminium,brass.

 

EMBOSSING PROCESS

This is smilier to press forming.the main difference that is used to create decorative features with some quite intricate detail.sheet metal embossing is a stamping process for producing raised and sunken designs or relief in sheet metal.the process can be made by means of matched male and female dies or passing sheet or roller strip of metal between rolls of the desired pattern.

HEMMING

Hemming is a forming operation in which the edges of sheet folded or folded over the another part in order to achieve thight fit .normally hemming operations are used to connect parts together to improve the apperance of the part and reinforced the part edges.

HOOD COMPONENTS

1.Outer panel

2.Inner panel

3.Hings

4.Striker

5.Reinforcement

OUTER PANEL

Outer panel is also called as skin of vehicle which is designed by styling team.the outer and inner pannel joined together by using hemming operation.

 

INNER PANEL

Inner  pannel used to strengthen the outer pannel.the primary function of inner pannel to disipate the impact forces during accident time by using embossing.to prevent the passenger.most of the inner pannel are made from pressing operations.the inner pannel consists of hinge assembly and striker.

HINGES

A hood hinge mechanism having a pivot pin having D shaped cross sectional poisitioned with in the recess.a bracket coupled with hood abut the support member when the hood is pivoted fully opened such than the hood is held open by the weight of the hood and is generally blocked from being detached from the vechile unless acted upon by the operator.

STRIKER

Hood latch striker designed for long lasting use.its durable steel construction safegurds against body damage ensuring the hood won't open unexpectedly open while driving.easy to install latch restore proper  hood functionally.

REINFORCEMENT

 The purpose of reinforcement to provide more strength of hinge and striker.basically thickness of reinforcement is 1.75mm.

MASTIC POINT

The main function of mastic point to reduce the NVH(noise vibration and harshness)that created on hood.that provide more number of mastic point at the center area of hood will increase the performance of car.

DESIGN APPROACH 

Master section provide the all the data of  so first we have create inner pannel.

now we have trimmed the outer pannel of half section and then the offset the surface 1.7mm

next we have using the offset on face command the curve wii be offseted on 20mm and then trimmed the sheet.

next we have offset the surface offser value is 4mm and trimmed the sheet.

by using law of through curve command join the bot offset surface.

next we have offset the 25mm offset value and trimmed the sheet.

join the edges by using through curve command.

by using sew command join the all the offset surface 

now we have fillet the all sharp edges using edge blend command

next we have create emboss on offset surface now we have create the emboss sketch and then using projected curve option projected the surface.

now we have create emboss on surface with 5 degree angle 15mm offset value.

next we have create the sketch on emboss surface to create the mastic point

now we have trim the emboss section.

now we have create the hinge and striker 

now we have mirror the surface.

now we have the thicken the sheet the value of 0.75mm

LATCH AND TRAJECTORY

the patch the striker will follow the hood while open and closing the hood using hinge axis.the hinge axis perpendicular to striker point.

next we have created hemming on outer pannel so trim the half section of outer pannel 

next we trim the outer edges with 0.2mm offset value

next we have law extension command exten the edges 

now offset the surface downward with 2.65mm value.side offset value is 6.75mm and then remove the unwanted surfaces.

 next we have using face blend command to bend the offset surfaces.

now we have mirror and thicken the sheet with 0.75mm value.

corner relief

 

HOOD ASSEMBLY

CONCLUSION

we have successfully created hood with consider of passenger safety and pedestrain safety.by using nx and also created the hood inner panel and hemming on outer pannel with help of master section and set the striker trajectory and reinforcements.