Week 1:- Introduction to BiW and Fixtures Challenge

1. BIW DEFINATION:-

BIW FIXTURE(BODY IN WHITE) IS STRUCTURE OF SHEETMETAL CAR WELEDED TOGETHER LIKE BODY UNDER &BODY INNER, FENDER,CLOSERUE.

PARTS:-BODY INNER,BODY OUTER,FLOOR ROOF,HOOD,CLOSURE.

2.NOMENCLATURE:- THRER ARE TWO TYPES USED UK AND US NOMENCLATURE.

NOMENCLATURE PART NAME:- SIDE ROOF,SIDE PANEL,UPPER A-PILLER,B-PILLER,C-PILLER,CROSS BEAM,OUTER WHEEL FENDER,FRONT DOOR ,REAR DOOR,TRUCK ETC.

3.FIXTURE:-FIXTURE IS HOLDING OR TO FIX THE PART IN PROPER WAY TO CARRY THE OPERTAION LIKE WELDING,CLUING,RIVTING ETC.

TYPES OF FIXTURE:-THERE ARE THREE TYPES OG FIXTURE

a) PRODUCTION FIXTURE b) PRE-PRODUCTION FIXTURE C) CHECKING FIXTURE.

4.BASIC PRINCIPLE :-

BASIC PRINCIPLE OF FIXTURE DESIGN IS BASED ON 3-2-1 PRINCPLE. THE PART HAVE 6 DEGREES OF FREEDOM IN THAT 6 HAS TRANSITION (X,-X,Y,-Y,Z,-Z) AND 6 HAS ROTATION (CX,CWX,CY,CWY,CZ,CWZ).IN FIXTURE WE HAVE TO ARREST 6 DEGREES OF FREEDOM. IN 3-2-1,3 MEANS BOTTOM SIDE THREE RESTING PROVIDED TO ARREST 3 DREGREES,2 MEANS IN VERTICAL DIRECTION TWO RESTING POVIDED TO LOCK 2 DEGREES AND 1 MEANS 1 UPWARD SIDE RESTING TO ARREST ONE DRGREES.

5.BIW STATIONS:-

THREAE ARE FOUR TYPES OF STATION

a) TOOLS b) GRIPPER c) STAND c) MISCELLANEOUS

a) TOOL:- TOOLS IS FIXTURE WHICH HOLD NUMBER OF UNITS TOGETHER TO HOLD THE CAR PART.

1) GEO TOOL 2)RESPOT TOOL 3)MARRIAGE TOOL 4)FRAMER TOOL

1.GEO TOOL:- A GEO TOOL IS FIXTURE IN WHICH GEOMATERY OF PANELS WHICH ARE WELD TOGTHER ACCURATELY.THE PIN TOLERANCEOF GEO PIN IS CLOSER TOLERANCE I.E.0.15mm IN GENRAL.IT IS VERY CLOSER TOLRANCE FIXTURE.FOR EX.PART HOLE IS 20mm THEN PIN DIA SHOULD BE 19.85mm.

2.RESPOT TOOL:- RESPOT TOOL IS FIXTURE WHICH CARRY THE REMAINING WELDING SPOT WHICH NOT DONE IN GEO TOOL.THE PIN TOLERANCE OF RESPOT TOOL IS -0.28mm.FOR EX.PART HOLE SIZE 20mm THEN PIN DIA SHOULD BE 19.72mm.THESE TOOL WELDED SPOT ONLY RIGID AND SUPPORT PURPOSE.

3.MARRIAGE TOOL:-A MARRIAGE TOOL IS A FIXTURE IN WHICH THE INNER PANEL ASSEMBLY & OUTER PANNEL ASSEMBLY ARE JOINED.

4.FRAMER TOOL:- THE STATION AFTER MARRIAGE TOOL IS THE FRAMER TOOL.IN THIS TOOL ROOF WILL BE ATTACHED FROM THE OUTPUT OF THE MARRIAGE TOOL.A CAR WILL NOW FORM A FRAME SO THE NAME ARISE IS FRAMER TOOL.

5.CHECKING TOOL:- AS FROM NAME WE UNDERSTAND THIS TYPE OF FIXTURES ARE USED FOR THE CHECKING PURPOSE OF THE PART.A CHECKING FIXTURE IS USED TO CHECK THE AUTOMOBILE PARTS OR ASSEMBLIES, ENSURING ALL COORIDINATES,POSITON,REATIVE DIMENSION.A CHECKING FIXTURE IS A TOOL WHERE WORK PIECE IS HOLD & VARIOUS MEASURING GAUGES ARE INTRODUCE TO ENSURE THE DIMENSIONS & REPEATABILITY

b) GRIPPER :-

A GRIPPER IS A DEVICE WHICH ENABLES THE HOLDING OF AN OBJECT TO BE MANIPULATED. THE EASIER WAY TO DESCRIBE A GRIPPER IS TO THINK OF THE HUMAN HAND. JUST LIKE A HAND, A GRIPPER ENABLES HOLDING, TIGHTENING, HANDLING AND RELEASING OF AN OBJECT. A GRIPPER IS JUST ONE COMPONENT OF AN AUTOMATED SYSTEM. A GRIPPER CAN BE ATTACHED TO A ROBOT OR IT CAN BE PART OF A FIXED AUTOMATION SYSTEM.

DIFFERENT GRIPPERS ARE USED IN BIW AS FOLLOWS,

A) MATERIAL HANDLING GRIPPER -

AS THE NAME SUGGEST THESE GRIPPERS ARE USED FOR MATERIAL HANDLING.THESE GRIPPERS CAN PICK ASSEMLY FROM ONE STATION & WILL DROP THE ASSEMBLY TO ANOTHER STATION.

B) PROCESS GRIPPERS -

THESE GRIPPERS ARE USED TO CARRYOUT SOME SPECIFIC PROCESS LIKE GLUING, WELDING. RIVETING ETC. IN ADDITION WITH MATERIAL HANDLING,THE GRIPPER WILL GOES UNDER GLUING STAND IN CASE OF GLUING PROCESS & WILL GOES UNDER THE PEDESTAL WELD STAND IN CASE OF WELDING PROCESS.

C) COMBO GRIPPER –

COMBO GRIPPERS ARE THE ONE WHICH CAN CARRY OUT MULTIPLE TASKS LIKE IT CAN DO MATERIAL

HANDLING & ALSO IT CAN CARRY OUT SOME SPECIFIC PROCESS LIKE GLUING, WELDING ETC. AS WELL.

WELD GUN + GRIPPER

D) DUAL GRIPPER -

THESE ARE TWO SIDED GRIPPERS. IN CASE WHEN WE WANT ONE LH & ONE RH PART, THESE GRIPPERS ARE USED. IT CAN HANDLE THE MATERIAL FROM ONE STATION TO ANOTHER STATION

GRIPPER + GRIPPER

C) STANDS -STANDS ARE USED TO HOLD PART WHEN NOT IN USE OR ALSO IT IS USED TO MOUNT SOME PARTS OR BODIES ON IT.

DIFFERENT STANDS ARE USED IN BIW

A) PEDESTAL STANDS -

WELD GUN IS MOUNTED ON THE FIXED STAND WHICH IS MOUNTED TO THE FLOOR PERMANENTALY. THE GRIPPER CAN CARRY THE PANEL UNDER THE STAND TO DO THE OPERATION

B) GLUING & SEALER STAND –

GLUING GUN OR SEALER GUN IS FIXED TO A WELDED OR A STANDARD STAND WHICH IS GROUTED TO THE FLOOR PERMANENTLY.

C) DOCKING STAND –

THE ROBOTS HAVE SOME LIMITATIONS SUCH AS THE PAYLOAD CAPCITY OF THE ROBOT & ALSO DUE TO LACK OF SPACE. WHEN WE SELECT THE ROBOT FOR MULTITASKING IT CAN'T DO BOTH THE TASK SIMULTANEOUSLY DUE TO LIMITATIONS. IN THIS KIND OF CASE, WE ADD DOCKING STAND TO PUT SOME EQUIPMENT WHICH IS NOT IN USE FOR THE CURRENT OPERATION BUT WILL BE REQUIRED FOR NEXT OPERATION. HENCE THE ROBOT CAN DROP A GRIPPER OR GUN & PICK NEXT OPERATION EQUIPMENT TO COMPLETE THE TASK FROM THE DOCKING STAND.

D) DATE STAMP STAND -

EVERY MANUFACTURED PRODUCT HAVE SOME DATA TO STAMPED OR TO BE EMBOSSED ON IT LIKE SERIAL NO, BATCH NO, DATE ETC. FOR SOME FUTURE REFERENCE OR FOR DATA COLLECTION.

THE REQUIRED DATA IS STAMPED OR EMBOSSED BY USING THE STAMPING DEVICE MOUNTED ON THE STAND.

4) MISCELLANEOUS STAND -

1. CURING- AFTER GLUING IT NEEDS SOME TIME TO COOL DOWN, SO WE PUT ASSERNLY ON SOME BELTS & IT WILL TAKE THE PANEL TO ANOTHER STATION & MEANWHILE GLUING WILL COOL DOWN.
2. BUFFER STAND- AFTER SOME OPERATION WE CAN PUT THE NO. OF ASSEMBLIES IN THIS STAND WHICH IS BUFFER STOCK & IT CAN BE TRANSPORTED TO ANOTHER STATION IN EASY WAY. THEY ARE ALSO USED TO STORE THE INVENTORY WHILE THE MACHINE IS UNDER GOING FOR SOME MAINTAINENCE.
3. TAKE OUT TROLLEYS - IT USED TO TAKE OUT SOME PANELS FOR INSPECTION TO RECTIFY THE PROCESS IS GOING IN RIGHT OR NOT BETWEEN THE CYCLE.
4. CONVEYOR - CONVEYOR IS THE ROTATING PATH WHICH TRANPORT THE PARTS TO THE NEXT STATION WHICH ARE KEPT OVER IT.
6. THE BASIC TERMINOLOGIES USED IN BIW FIXTURE DESIGN

   THE FOLLOWING TERMINOLOGIES ARE USED IN BIW

   1. NC/MYLARS/FINGERS- MYLARS IS THE COMPONENT WHICH HOLDS THE PANEL WHILE OPERATION. THESE ARE PLACED FROM TOP SIDE & FROM BOTTOM SIDE ALSO. THE TOP SIDE MYLARS CALLED AS CLAMPING MYLARS & THE BOTTOM SIDE MYLARS CALLED AS RESTING MYLARS. EVERY CLAMPING MYLARS HAVE RESTING MYLARS. IT DONT ALLOW DEFORMATION OF THE PART DUE TO WELDING STRESSES.
   2. PRINCIPLE LOCATING POINT (PLP) - THESE ARE THE POINTS WHICH ARE USED FOR THE ACCURATE LOCATION OF THE PART TO MAINTAIN THE GEOMETRY OF THE ASSEMBLY. THERE ARE LOTS OF HOLES ON THE PANEL WHICH ARE NOT ACCURATE DUE TO STAMPING OPERATION. THE PLP ARE DEFINED IN THE DRAWING. THE POSITIONAL DIMENSIONS OR RELATIVE DIMENSIONS ARE VERY PRECISE IN STAMPING & IN FIXTURES ALSO.
   3. RISERS - RISERS ARE OF DIFFERENT TYPE LIKE L-TYPER RISES, SQUARE TUBE RISER ETC. RISER IS THE MANUFACTURING PART WHICH GIVES HEIGHT TO THE ASSEMBLIES.
   4. BLADE- BLADES ARE PLATES MOUNTED ON THE RISER. OTHER PARTS LIKE CYLINDER, ARMS ETC ARE MOUNTED ON THE BLADE.
   5. SHIMS - SHIMS ARE THE SMALL PART WHICH COMES WITH THE THICKNESS OF 0.1MM, 0.2MM, 0.5MM ETC. THESE WILL COMPENSATE THE STACKUP TOLERANCE WHICH REFLECTS AT THE PANEL HOLDING PART CALLED MYLARS. WE GIVE TOLERANCE TO ALL THE PARTS OF THE FIXTURE. DUE TO THIS TOLERANCE THE MYLARS WILL EITHER LIFT UP OR GOES DOWN FROM ITS DEFINED POSITION. IF THE MYLARS GOES DOWN FROM THE DEFINED HEIGHT IT WILL MAKE IMPRESSION OR DENT ON THE PANEL. IF THE MYLAR'S LIFT UP THEN THERE WILL BE A DISTORSION DUE TO WELDING STRESS. TO ADJUST THE MYLARS AT ITS DEFINED POSITION WE USE SHIMS SO THE PANEL WON'T DEFORMED & ALSO DON'T GET ANY IMPRESSION ON IT.
   6. ROUGH LOCATORS - THE OPERATOR CAN PLACE THE PART IN WRONG ORIENTATION MISTAKANELY. THE ROUGH LOCATOR WILL WORK AS A GUIDE WHILE PLACING THE PART IN THE FIXTURE & THE PART WILL BE LOADED IN DESIRED ORIENTATION. IT IS A PART OF FOOL PROOFING.
   7. HARDWARE’S - HARDWARE’S ARE LIKE THE HEX HEAD BOLTS, ALLEN BOLTS, HEX NUTS, SPRING WASHERS, SELF LOCKING NUTS ETC.
   8. CMM CMM STANDS FOR COORDINATE MEASURING MACHINE. IT IS A DEVICE THAT MEASURES THE GEOMETRY OF PHYSICAL OBJECTS BY SENSING DISCRETE POINTS ON THE SURFACE OF THE OBJECT WITH A PROBE. IT GENERATES REPORT MY COMPARING THE DATA WITH THE CAD FILE DATA
   9. UNIT - THE FIXTURE IS THE ASSEMBLY OF DIFFERENT TYPES OF UNITS TO FORM A FIXTURE. THERE ARE DIFFERENT UNITS LIKE PIN UNIT, BASE UNIT, CLAMPING UNIT ETC.
   10. NUMBER PLATES NUMBER PLATE IS THE ALUMINIUM EMBOSSED PLATE PLACED ON THE EACH UNIT FOR EASILY RECOGNISING THE UNIT.
   11. NAME PLATE - THE DATA LIKE MANUFACTURING COMPANY NAME, FIXTURE TYPE, FIXTURE WEIGHT ETC. IS EMBOSSED ON THE PLATE & JOINED TO THE FIXTURE.
   12. CLAMP ARM - CLAMP ARM IS THE PART OF CLAMP UNIT WHICH MOVES OVER A AXIS. OVER CLAMP ARM THE MYLARS ARE MOUNTED
   13. PIVOT - IT IS A AXIS ABOUT WHICH THE CLAMP ARM WILL ROTATES.
   14. CLASS A SURFACE/SKIN SURFACE - THE OUTER PANELS OF THE CAR LIKE HOOD, DOOR. BACKDOOR, FENDER. ROOF ETC. ARE VISIBLE TO THE CUSTOMER. THE OUTER PANELS SHOULD BE ASTHETICALLY VERY GOOD. NO ANY SCRATCHES OR DENT IS ACCEPTABLE OVER IT. WHILE DESIGNING THE FIXTURE TO THE SKIN SURFACE THE CLAMPING MATERIAL SHOULD BE SOFT, SO THAT IT COULD NOT ABLE TO LEFT ANY IMPRESSION OR DENT OVER SKIN. GENERALLY NYLON OR PU MATERIAL IS USED FOR CLAMPING PURPOSE.