Hood design-Week 2

DESIGNING OF HOOD

HOOD IN AUTOMOBILE: Hood refers to the metal cover that encloses and protect the engine ccompartment at the front of the vechile. In some regions its also known as "bonnet" , the main purpose of the hood is to sheid the engine and its components from the elements such as snow, rain and debris , its used to decorate the car for styling purpose

DESIGN CONSIDERATION OF HOOD:

AS A BIW ENGINNER THE DESIGN CONSIDERATION OF HOOD ARE

• STRUCTURAL INTERGRITY
• CRASHWORTHINESS
• PEDESTRIAN PROTECTION
• MANUFACTURABILITY AND ASSEMBLY
• HINGE AND LATCH MECHANISM
• SEALING AND WATER MANAGEMENT
• DURABILITY AND TESETS
• AERODYANMICS AND WIND NOISE

STRUCTURAL INTERGITY:THE HOOD SHOULD BE DESGINED TO PROVIDE ADEQUATE STRENGTH AND RIGIDITY WHILE MAINTANING A LIGHT WEIGHT STRUCTURE

CRASHWORTHINESS: THE HOOD IS AN ESSENTAIL PART OF THE VECHILE CRASH MANAGEMENT SYSTEM. IT UST BE DESGINED TO ABSORB AND DISTRIBUTE IMPACT ENGRY DURING FRONTAL COLLISIONS TO PROTECT OCCUPANTS AND MINIMIZE DAMAGE TO CRITICAL COMPONENTS LIKE ENGINE AND SUSPESNION

PEDESTRIAN PROTECTION : MODERN CAR HOODS OFTEN HAVE FEATURE LIKE ENERGY OBSERVING MATERIALS AND SPECIFIC DEFORMAION ZONES TO MITIGATE INJRIES TO PEDESTRIANS DURING ACCIDENT

MANUFACTURABILITY AND ASSEMBLY:BIW ENGINNER MUST DESIGN THE HOOD WITH MANUFACTURING AND ASSEMBLY IN MIND , THIS INCLUDES ENSURING EASE OF STAMPING , WELDING , OR BONDING PROCESSES DURING PRODUCTION

HINGE AND LATCH MECHANISMS: THE HOOD HINGE AND LATCH MECHANISMS MUST BE ROBUST AND RELIABLE TO ENSURE SMOOTH OPERATIONS AND REVENT UNINTENDED OPENING WHILE DRIVING

SEALING AND WATER MANGEMENT:PROPER SEALING OF THE HOOD INTERFACE IS CRUCIAL TO PREVENT WATER LEAKAGE INTO THE ENGINES COMPARTMENT OR PASSENGERS CABIN DURING RAIN OR CAR WASHING

DURABILITY AND TESETING:HOOD UNDERGOES RIGOROUS TESTING TO ENSURE THEY MEET QUALITY AND DURABILITY STANDARDS. TESTING INCLUDES VALIDATION FOR RESISTANCE TO FATIGUE , DEFORMATION AND VIBRATION

AERODYANMICS AND WIND NOISE:BIW ENGINEERS CONSIDER THE HOOD SHAPE AND DESIGN TO OPTIMIZE AERODYNAMICS AND REDUCE WIND NOISE AT HIGHER SPEEDS, SMOOTH AIRFLOW OVER THE HOOD HELPS IMPROVE VECHILE AFUEL EFFFIENCY AND PERFORMANCE

COMPONENTS OF HOOD:

INNER PANEL: ITS AN INTERGRAL COMPONENT OF VECHILE FRONT END STRUCUTRE , ITS LOCATED ON THE UNDERSIDE OF THE OUTERHOOD SKIN AND PLAYS SEVERAL ROLES LIKE

1. SOUND DAMPING
2. HEAT INSULATION AESTHETIC APPEARANCE
3. PROTECTION OF UNDERHOOD COMPONENTS
4. SAFETY ENHANCEMENT
5. ADHESIVE BONDING SURFACE
6. WEIGTH OPTIMIZATION

OUTER PANEL:IT IS THE VISIBLE AND OUTERMOST PART OF THE HOOD THAT FACES THE FRONT OF THE VECHILE , ITS IS THE COMPONENT THAT PEOPLE SEE WHEN LOOKING AT THE CAR FROM THE FRONT ITS ALSO PLAY SEVERAL IMPORANANT ROLES

1. ASTHETICS
2. WINDRESISTANCE AND AERODYNAMICS
3. PROTECTION FROM EXTERNAL ELEMENTS
4. HOOD LATCH AND HINGE ATTACHMENT
5. BRAND INDENTITY
6. CORROSION RESISTANCE
7. PEDESTRIAN PROTECTION
8. CRASH SAFETY

LATCH AND STRIKER:

LATCH: ITS A MECHANICAL COMPONENT THAT SECURES THE HOOD IN ITS CLOSED POSOTIONS , IT TYPICALLY CONSISTS OF A HOOK OR A PAWL THAT ENGAGES WITH A MATING COMPONENT (STRIKER) TO PREVENT THE HOOD FROM OPENING UNINTENTIONALLY , LATCHES OFTEN HAVE A REALASE MECHANISM THAT ALLOWS USERS TO OPEN THE HOOD WHEN NEEDED.

STRIKE: ITS THE STRIKER PLATE OR CATCH , IS THE COUNTERPART OF LATCH , ITS A METAL PLATE OR BRACKET MOUNTED ON THE VECHILE BODY STRUCTURE , WHEN THE HOOD IS CLOSED THE LATCH HOOK ENGAGES WITH STRIKER CREATING SECURE AND RELIABLE CLOSURE

MASTIC DATA: AUTOMOTIVE MASTIC DATE CAN BE BITUMEN BASED , RUBBER BASED OR SYNTHETIC MATERIALS, ITS USED FOR SOUND , DAMPENING , VIBRATION REDUCTIONS AND SEALING PURPOSE , IT HAVE HIGH ADHEVSIVE STRENGTH , TEMPERATURE RESISTANCE , FLEXIBILITY AND ACOUSTIC PROPERTIES

EMOBOSS: ITS A DECORATIVE TECHINIQUE USED TO CREATE A RAISED OR THREE DDIMENSIONAL DESIGN ON A SURFAE , IT INVOLVES IMPRESSING PATTERN ON TO A MATERIAL , TH EPROCESS MAY USE HEAT, PRESSURE , OR BOTH WITH SPECIALIZED TOOLS AND DIES WITH THE DESIRED DESIGN IT INVOLVES IN BODY PANELS, BADAGES AN LOGOS ,INTERIOR TRIM UPHOLSTERY , STEERING WHEELS , FLOOR MATS , EMBLEMS AND TRIMS

DEEP DRAWING:

ITS A WIDELY USED METAL FORMING PROCESS FOR MANUFACUTRING AND VARIOUS PARTS FOUND IN CAR, IT ALLOWS CAR MANUFACTURERS TO PRODUCE COMPLEX AND INTRICATE SHAPES WITH HIGH PRECISION AND CONSISITENCY, IT ALLOWS CAR MANUFACTURESES TO ACHIEVE CONSISTENCY QUALITY IN PARTS , WHICH IS CRUCUAL FOR MEETING SAFETY AND PERFORMANCE STANDARDS

DEEP DRAWING IS TYPICALLY PERFORMED USING SPECIALIZED MACHINES AND DIES DESIGNED FOR SPECIFIC OMPONENT , THE PROCESS REQUIRED AREFUL PLANNING , MATERIAL SELECTION AND QUALITY CONTROL TO ENSURE THAT THE FINAL PARTS MEET THE REQUIRED SPECIFICATIONS AND PERFORMANCE STANDARDS OF THE AUTOMOBILE INDUSTRY

PARTS IN CAR FOR DEEP DRAWINGS:

1. BODY PANELS
2. ENGONE COMPONENT
3. EXHAUST SYSTEM
4. FUEL SYSTEM
5. SUSPENSION PARTS

ADVANTAGES OF DEEP DRAWING:

• ABILITY TO PRODCE MASS PRODUCE PARTS WITH HIGH PRECICION
• REDUED MATERIAL WASTE
• COST EFFECTIVENESS

HEMMING:

HEMMING IS A METAL FORMING PROCESS USED TO JOIN TWO SHEETS OF METAL TOGETHER , TYPICALLY BY FOLDING ONE SHEET OVER OTHER , THE PURPOSE OD HEMMING IS TO CREATE A SMOOTH AND ROUNDED EDGES THAT NOT ONLY ENHANCES THE APPERANCE OF THE JOINT AND ALSO PROVIDES ADDITIONAL STRENGTH AND IMPROVES SAFETY IN CERTAIN APPLICATION, ITS COMMONLY USED IN BODY PANELS , HOOD, DOOR, AND TRUNK LIDS.

HEMMING PROCESS:

1. PREPARING THE SHEETS
2. BENDING THE TOP SHEET
3. SECURING THE SHEET
4. TRIMMING AND FINISHING

ADVANTAGES OF HEMMING:

• INCREASED STRENGTH
• SEALED EDGES
• IMPROVED SAFETY
• ENHANCED AESTHETICS

DESIGNING OF CAR HOOD:

MASTERSECTION AND REQUIREMENT FOR HOOD

Hood Thickness Information

• Outer Panel Thickness = 0.75mm
• Inner Panel Thickness = 0.75mm
• Reinforcement Thickness = 1.5mm

HOOD OUTERPANEL:

HOOD INNERPANEL:

USING WAVE LINKER GEOMETRY EXTRACTING THE HOOD SURFACE AND TRIMMING WITH CENTRE DATUM PLANE

TOOLS USING NXCAD

• DATUMPLANE
• EMBOSS
• BRIDGE CURVE
• EDGE BLEND
• THROUGH CURVE
• OFFSET CURVE
• TRIM SHEET
• SEW
• PROJECT CRUVE
• FACE BLEND
• EXTENED SHEET AND MIRROR USING THIS THE INNER HOOD OF CAR IS DESIGNED

LATCH,STRIKER AND HINGE ATTACTMENT

USING ASSEMBLY CONSTRIANS ITS FIXED IN THE INNER PANEL OF HOOD

THE HINGE IS MIRRORED TO THE CENTRE DATUM PLANE

LATCHE TRAJECTORY:

• IT REFERS TO THE PATH OR MOVEMENT THAT A LATCH FOLLOWS DURING ITS OPERATION , THE LATCH AND STRIKER POSITIONED TENTAVIELY , WHEN ASSEMBLING THE LATCH STRIKER WITH HOOD PANEL , ITS TAKEN AS CIRCLE WITH HINGE AXIS AS THE CENTRE OF CIRCLE , STRIKER IS PLACED IN 90DEGREE SUCH THAT TANGENT TO THE CIRCLE

• CLOSING TRAJECTORY : WHEN CLOSING A HOOD EQUIPPED WITH LATCH E, THE TRAJECTORY INVOLVES BRINGING THE LATCHE HOOK OR PAWL INTO CONTACT WITH THE MATING STRIKER PATH IT CAN OPERATED MANUALLY OUT AUTOMATED MECHANISM

• OPENING TRAJECTORY: TO OPEN A HOOD , THE TRAJECTOY INVOLVES DISENAGAING THE HOOK FROM STRIKER PLATE ,WHEN THE RELEASE ACTION IS INITIAATED THE HOOK IS DISENGAGED FROM STRIKER AND THE HOOD CAN BE PULLED OUT

HEMMING PROCESS:

FRONT AND REAR RELIEF:

FORCE DISTRIBUTION:

FORCE DISTRIBUTION TOWARDS HINGES

ISOMETRIC VIEW OF HOOD