Hood design-Week 2
HOOD
HOOD IS THE HINGED COVER THAT RESTS OVER THE ENGINE BAY OF A FRONT-ENGINE VEHICLE. THE CAR HOOD PROTECTS THE ENGINE AND CONNECTED PARTS FROM THE ELEMENTS WHILE PROVIDING EASY ACCESS FOR REPAIRS AND MAINTENANCE.
CAR HOODS ARE TYPICALLY CONSTRUCTED FROM STEEL AND SOMETIMES FROM ALUMINUM. AFTERMARKET CAR HOODS MAY BE CONSTRUCTED FROM VARIOUS OTHER MATERIALS, INCLUDING CARBON FIBER, FIBERGLASS, OR DRY CARBON.
A CONCEALED LATCH IS TYPICALLY USED TO LOCK THE HOOD IN PLACE WHILE DRIVING. A RELEASE FOR THE MECHANISM CAN BE ACCESSED FROM THE DASH BELOW THE STEERING WHEEL. ON RACE CARS AND VEHICLES WITH AN AFTERMARKET HOOD, EXPOSED PINS MAY BE USED TO SECURE THE CAR HOOD.
HOODS SOMETIMES CONTAIN A HOOD SCOOP OR A POWER BULGE TO ALLOW FOR GREATER ENGINE CAPACITY AND AIRFLOW TO INCREASE THE CAR’S PERFORMANCE OUTPUT.
LATCH TRAJECTORY
MOST VEHICLES OF COURSE, HAVE A HOOD. HOODS ARE SQUARE- OR RECTANGULAR-SHAPED PANELS THAT LIE FLAT ACROSS THE FRONT-END OF A VEHICLE. THEY ARE DESIGNED TO COVER EQUIPMENT LIKE THE VEHICLE’S MOTOR, TRANSMISSION, RADIATOR, ALTERNATOR, BATTERY AND OTHER COMPONENTS. IF YOU NEED TO ACCESS ANY OF THESE COMPONENTS, THOUGH, YOU’LL HAVE TO OPEN THE HOOD.
YOU CAN OPEN THE HOOD ON A VEHICLE BY ENGAGING THE HOOD LATCH. HOOD LATCHES TYPICALLY CONNECT TO A CABLE. ENGAGING THE HOOD LATCH WILL RELEASE THIS CABLE, AFTER WHICH YOU CAN LIFT THE HOOD.
WHILE ASSEMBLING THE LATCH WITH THE HOOD PANEL IT IS STRICTLY RECOMMENDED THAT THE POSITION OF LATCH STRIKER SHOULD BE PLACED SUCH THAT THE LATCH STRIKER EXACTLY FIT INTO THE LOCK HOLE IN THE ENGINE COMPARTMENT. KEEPING THIS IN MIND, THE LATCH STRIKER IS PLACED ON THE INNER HOOD PANEL USING LATCH TRAJECTORY PATH. THIS PATH IS CREATED USING THE THE HINGE AXIS TAKEN AS REFERENCE TO DRAW A BIG TRAJECTORY PATH.
MASTIC DATA
A HOOD INNER PANEL AND A HOOD OUTER PANEL. THE HOOD INNER PANEL IS ENCLOSED BELOW THE OUTER PANEL AND THEREBY PROVIDES RIGIDITY TO THE HOOD. WHEN THESE PARTS ARE ASSEMBLED TO FORM A HOOD A SMALL GAP REMAINS BETWEEN THESE TWO PARTS AS THEY ARE BOTH METAL PARTS THIS MAY LEAD TO NOISE AND VIBRATIONS WHEN THE VEHICLE IS IN RUNNING CONDITION WHICH IS UNDESIRABLE TO AVOID THIS MASTIC SEALANT IS FILLED BETWEEN THIS SMALL GAP.
A MASTIC SEALENT IS USED BETWEEN THE OUTER AND THE INNER PANNEL OF THE BOND THE TWO PANNELS. THE MASTIC ALSO PROVIDES THE STRENGTH FOR THE HOOD OUTER PANNEL. THIS CAN BE A GLUE OR A RUBBER WHICH IS PLACED IN BETWEEN THE INNER AND THE OUTER PANEL AT POINTS KNOWN AS MASTIC POINTS.
EMBOSS
AN EMBOSS IS A METAL FORMING PROCESS IN WHICH A HIGH PRESSURE IS APPLIED ON A DIE TO MAKE A IMPRINT ON THE WORKING SURFACE. THE IMPRINT CAN BE RAISED OR SUNKEN. IN THIS PROCESS IT IS ASSUMED THAT THE METAL THICKNESS REMAINS THE SAME WHILE EMBOSSING.
THE IMPLEMET OF EMBOSSES ARE VERY IMPORTANT ON THE INNER HOOD SINCE IT PLAYS A IMPORTANT ROLE IN SAVING HUMAN LIFE DURING A CRASH FROM THE FRONT.
DEEP DRAWING
DEEP DRAWING IS A MANUFACTURING PROCESS IN WHICH A SHEETMETAL IS APPLIED WITH A FORCE BY A METAL DIE TO FORM A DESIRED SHAPE. IF THE DEPTH OF THE DRAWN PART IS MORE THAN THE DIAMETER OF THE METAL FLANGE THE PROCESS IS CALLED DEEP DRAWING. IN THE AUTOMOBILE INDUSTRY THE DEEP DRAWING IS DONE USING RIGID TOOLS LIKE PUNCH, DIE AND BINDERS.
HEMMING
THE HEMMING PROCESS IS A METAL FORMING PROCESS IN WHICH A SHEETMETAL IS FOLDED, OR FOLDED OVER ANOTHER SHEETMETAL. THIS GIVE THE TWO METALS PARTS A TIGHT FIT. THIS IS USED IN AUTOMOBILE INDUSTRY TO CREATE DOORS, HOOD, TRUNK, ETC. THE OUTER AND THE INNER PANELS ARE FITTED TOGETHER USING THIS PROCESS.
THERE ARE CONVENTIONAL HEMMING AND ROLLER HEMMING. THE ROLLER HEMMING IS USED FOR HEMMING THE HOOD OUTER PANEL. THE CONVENTIONAL HEMMING IS USED FOR MASS PRODUTION.
HINGE
A HINGE IS A MACHINE ELEMENT THAT CONNECTS TWO BODIES ALLOWING ANGULAR MOVEMENT ABOUT A FIXED AXIS OF ROTATION, ALL THE WHILE PREVENTING TRANSLATIONS AND ROTATIONS ON THE REMAINING TWO AXES. A HINGE CAN BE CONSIDERED AS A JOURNAL BEARING WITH ONLY ONE DEGREE OF FREEDOM WHERE A SHAFT IS ROTATING IN A HOLE. HINGES ONLY ALLOW ONE ROTATION, EITHER YAWING (THE MOST COMMON), PITCHING, OR ROLLING. HINGES ARE A JOINTED AND FLEXIBLE DEVICE THAT IS ATTACHED TO ANY SWINGING PART. HINGES ARE MECHANICAL BEARINGS THAT ARE USED TO CONNECT TWO SWINGING OBJECTS OR POINTS AND GIVE THEM THE FREEDOM TO MOVE RELATIVE TO EACH OTHER. HINGES HAVE LIMITED MOVEMENT, ALLOWING THE JOINT TO MOVE ONLY AT ONE ANGLE AND RESTRICTING THE OTHER MOVEMENTS OF SWINGING PARTS.
REINFORCEMENT
THE STRIKER AND HINGES ARE ATTACHED AT THE LOWER SIDE OF THE INNER PANEL. IT IT CAN BE DONE BY DIRECTLY THEN MORE STRESS CAN ACT AT THE PARTICULAR AREA IN THE INNER PANEL, IT MAY CAUSE DEFORMATION OF THE INNER PANEL AT THAT PARTICULAR REGION. SO THAT THE REINFORCEMENT COMES IN AND PLACED BETWEEN THE STRIKER AND THE HOOD, HINGE AND THE HOOD. IT CAN ABLE TO REDUCE TO DEFORMATION AND STRENGTHENING THE INNER PANEL AT THAT PARTICULAR REGION.
CONSEQUENTLY, TO AVOID ANY FAILURE TO ROTATE AND LATCH REGION UPHELD WITH EXTRA MATERIALS WHOSE THICKNESS IS REGULARLY DIRECTED BY THE VEHICLE. THE REINFORCEMENTS GIVE ADDITIONAL FORTITUDE INNER PANEL OF THE CENTRES WHERE VARIOUS PARTS, FOR INSTANCE, THE LOCK AND ROTATE, WILL BE PUT. THE REINFORCEMENT ENSURES THAT THE TURNS AND THE SNARE HAVE BETTER ASSISTANCE TO AVOID FRUSTRATION.