Week 1:- Introduction to BiW and Fixtures Challenge

1.What is BIW & define its parts?

BIW (Body in White) is the common terminology used to mention the car sheet metal welded structure (body shell).

Its just a sheet metal welded structure.BIW will not have doors,engines,chasis or any other parts.

BIW structure can be divided into following sub structures :-

1) Under Body Structure

2) Front End Structure

3)Body Side Structure

4) Closures

5) Roof

1)Under Body Structure :

• Dash Panel -provides partition between engine and the driver cabin.
• FRT floor - provides base for seats.
• Raiser- connects front floor to rear floor by providing level difference.
• Rear Floor - floor on the rear of the car and provides partition from ground and base for rear seats.
• Rear Wheel House

2) Front End Structure:

• Plenum Panel- a chamber located b/w the throttle body and runners of the intake manifold.
• FRT wheel house(FENDER) - is an encasement around front wheel.
• Wing Panel- Outermost Side panel in the front.
• Cowl - portion of the body bounded by the front fenders,the base of the windshield and the rear edge of the hood.
• Upper Tie Bar - Upper panel in front connecting the two sides of the front structure.
• Lower Tie Bar - Lower panel in front connecting the two sides of the front structure.

3) Body Side Structure:

• A-Pillar-Front Most support to the Roof.
• B-Pillar-Second Support to the Roof.
• C/D -Pillar- C- is the rear most support to the roof in case of two row seating system,it will be third one. D-is the fourth support usually the rear side of the quater panel.
• Ring Panel- Structure panel connecting rear and front portion.
• Quater Panel- Rear most panel of the body side structure.
• DripRails/Gutter -An exposed channel applied to the roof over the side windows to divert the water away from the windows.

4)Closures :

• All Doors .
• Hoods/Bonnet - a hinged panel providing access to the engine compartment.

5)Roof Structure

• Roofs
• Headers - a structural member above the windshield at the juncture at forward edge of the roof panel.
• Bows.

2)What do you understand by BIW nomenclature?

Nomenclature is naming different parts of the BIW . Nomenclature can differ from country to country . It is a name given to automotive sheet metal components.

3) What is fixture and its type?

A fixture is a device which holds and locates a workpiece during an inspection or for a manufacturing operation.

1. Turning fixtures.
2. Milling fixtures.
3. Broaching fixtures.
4. tagGrinding fixtures.
5. Boring fixtures.
6. Indexing fixtures.
7. Tapping fixtures.
8. Duplex fixtures.
9. Welding fixtures - BIW welding fixture comes under welding fixture.
10. Assembly fixtures.

Types of BIW fixtures are

1. Production Fixture-mass production fixture
2. Preproduction Fixture- For initial batch production
3. Checking Fixture - For car panel Geometric Inspection Purpose

4) What is the basic principle of fixture design ?

Any freebody has 12 degrees of freedom.(6 translation degrees of freedom & 6 rotational degrees of freedom).You must fix all 12 degrees of freedom to locate the workpart in the fixture.

Generally 3-2-1 principle is used to locate parts in BIW welding fixture.3 Locators are used to locate primary datums, 2 Locators for secondary datum, 1 Locators for tertiary direction.

5) Elaborate types of BIW Stations?

BIW station are divided broadly into following four catagory.

1. Tools- GeoTool, Respot Tool,Hemming Tool, Marriage tool ,Framer Tool Etc.
2. Grippers-Material Handling Grippers, Process Gripper,Combo Gripper Etc
3. Stands- Pedestal Stand, Gluing stand, Docking Stand,Date Stamping Stand Etc.
4. Miscellaneous - Curing Stand, Buffer Stand,Racks, Pallets,Take Out Trolleys,Conveyors Etc.

6) What are the basic terminologies used in the BIW Fixtures?

• Mylars/NC/fingers:-Rest Or clamp Block which are used to hold 2 to 3 BIW sheet metal parts.
• Spot Welding- Its a type of resistance welding where 2 or 3 sheets are joined together.
• Cycle Time :- Time required to excute a task.
• PLP (Principle Locating Points):- These are predefined Points on the car panel where we use locating pins and clamps to hold the panel.
• Round Pins:- Pin used for location of Sheet Metal Car Panel
• Diamond Pins :- Diamond shaped pin used to restrict movement in two directions.
• Shim Packs:- These are parts used to rectify the tolerance stackup and to locate the car panel correctly.
• Rough locators:- Used in manual fixture to guide the panel onto correct location so as to minimize the error.
• Risers :- Are the parts which gives height to the assembly. It is used mounts various parts such as Mylars, L block, Blade, Clamping Cylinders etc. It can be made with 50mm or 63mm thick plate or It can also be welded construction.
• Blade : Blades are mounted on the riser. Mylars, Pivoting clamp cylinders are mounted on the Blade.
• Units : In the BIW fixture different types of units are used to Locate the car panel. Clamp Unit, Pin Unit, Slide Unit, Dump Unit Etc.