Week 1:- Introduction to BiW and Fixtures Challenge

1)What is BIW & Define its parts?

Ans:

BIW Stands for Body in white.its the stage that autombile manufacturing car body frame and its parts joined together. that is before the painting chassis and subassemlies or parts like glass, seats this all parts integarated into the structure.

there are many techniques and process of joining the parts such as Welding ( MIG/MAG), reveting, clinching, bonding,brazing and etc..

BIW parts catagorised below.

a)Underbody structre.

b)Front end structure.

c)Body side structure.

d)Closure.

e)Roof.

All those substructure consist of following major panels.

• Under body:

a)Dash panel- it provids partition between Engine and driver cabin.

b)FRT Floor- It prover base to the seats.

c)Raiser- Connects front floor to rear floor by providing the level differance.

d)Rear Floor- floor on the rear side of car an dit provids partition from ground and base for the seats.

e)Rear whhel inhouse.

• Front end structure:

a)Planum panel: A chamber located between the trhrottle body and runner of the intake manifold.

b)Front wheel house(Fender)- is an encasement around the front wheel.

c)Wing Panel-Outer side panel in front body.

d)Cowl-Portion of the body bounded by the front fenders, the base of windshield & the rear edge of hood.

e)Upper tier bar-upper panel is front connecting to the 2 sides of structure.

f)Lower tier bar-Lower panel is front connecting to the 2 sides of structure.

• Body Structure:

a)A Piller- Front side support of the roof.

b)B Piller- Second support of the roof.

c) C/D Piller- Cpiller is the rear most support of the roof incase 2 row seating it will be third one.

      D piller is the fourth support usually rear side of quarter panel.

d)Ring panel-a structure panel connecting to rear and front portion.

e)Quarter panel-rear most panel of the body side structure.

f) Drip rails/Gutters-eposed channel applied to the roof of over side the windows to direct water awy from the windows.

• Closure:

a)All doors.

b)Hoods & Bonnet- A hinged panel providing access to the engine compartment.

• Roof Structure-

a)Roof

b)Headers- structural member above windshield at juncture with the forward edge of the roof panel.

c) Bows.

2)What do you understand by BIW Nomenclature?

Ans:

Nomenclature is basically choosing of names for things.

BIW have many no of parts in it. in those all parts have different names.

As the automotive industry spread all over the world. 

So the same parts having different names in differernt region.

Examples:

UK Consideration                             Us considration

A-Inner wing panel                  Motor compartment side panel

B-Upper wing member             Motor compartment upper upper rail.

C-Suspension tower                 Shock tower

D-Upper A Pillar                       A piller or windshield pillar

E-Windscreen Header rail         Windshield header or front head.

F-Roof stiffner                         Roof Bow.

G-Rear parcel tray                    Package shelf

H- Cant rail                              Side Roof Rail

I-Backlight frame                      Backlight header

J-C Pillar                                   C pillar

K-D pillar                                  D Pillar

L- Rear Quarter panel                 Rear Quarter Panel

M-Boot Floor Panel                     Rear Compartment panel.

N-Rear seatback ring                 Rear seatback opening frame

O-Rear Seat panel                     Rear Seat Back panel.

P-B Pillar                                   B pillar or center pillar

Q-Floor panel                             Floor pan

R-Still                                        Rocker Or Rocker Panel

S- Lower A Pillar                         Front Body Hinge Piller

T-Dash Panel                              Dash Panel

U- Engine Rail                            Lower Compartment rail

V-Front bumper                         Front Bumper

W-Spare wheel well                    Spare tire Well

X-Center Tunnel                        Tunnel

Y- Rear Seat cross beam           #4 Crossbar

Z-Rear suspension support beam  #5 Crossbar         

3.What is the Fixture and its types ?     

Ans:

Fixture is the device which holds the body or workpice to be processed by 3-2-1 Priciple.

In BIW fixture, the fixtures are designed to hold the workpiece or parts during the welding.

it is necessary to hold the part proper location and restion to avoid distortion 7 maintain the required dimension & geometry of the parts.

BIW Fixture Requirements-

a)It should prevent distortion in parts during the welding opeatrtion.

b)the clamping need to be light but firm means clamping force should able to maintain the part it requires its postion without damaging the parts.

c)Fixture need to be quite stable rigid and withstand to the welding stresess.

d) Placement of clamping need to be clear of welding area.

f)the fixture should maintain consistency of geometry and dimesions to achieve reapitability.

Typeas of BIW fixtures

a) Production fixture:

This Fixture are used for mass production purpose. it require high consistency of through its operation to maintainn the geomerty of the parts so material used well tested for the hardness & Asthetics. The quality for maintaining dimension 7 Tolerance also checked. The production fixture is need to easy maintainace purpose. the fixture needs some maintainance after completing no of opeartion. the time requires for assembly & dis assembly should be low as possible which saves lot of time.

b)Production opeartion fixture:

These fixture are designed as prototype fixture to chekc the feasibility of initial batch  & To check which things need to be done improve before starting the production. this fixture to be taken as base fixture which sets as benchmark and    critria which helps us to rectify the errors that we could get from production opeartion fixtures. in this many manual opeartions involved many engineers & quality related engineers required. It has large cycle time compared to production fixtures. It requires lot of time and cost also. We have to maintain cost of car low as low as posible so we can directly go through the prodcuionfixture by considering the standerds,  checklist to maintain  the error free production.

c)Checking Fixture:     

these fixture are used for checkinng purpose. No operations like gluing, Welding or Hemming corried out in this fixtures. the guages are used in these fixtures to get dimensions and the tolerances part having & the data is compared with the designed dimension to check wheter the part is ok or not ok. the geometry of the welded parts is also the parts maintain the required dimension & Geometry.

4) What is the basic principle of Fixture design?

Ans:

For the fixture designer, the major portion of the design time is spent desciding how to locate the work piece in the fixture.

The basic is any body has 12 degrees of freedom that is translational and the rotational respective X,Y,Z Axis. To make sure all degrees of freedom we need to restrict of workpiece.

The jig and fixtures are tools used to holding the workpiece in correct location for mass production. Variuos types of fixture(like drilling fixtures, milling fixtures,& welding fixtures ) are used in industry. the 3-2-1 principle used in all types of fixture design.

 5) Elaborate the types of BIW stations?

BIW Station is the parts of Assembly line.BIW Lines are devided into zones this zones are again devided into stations.

The BIW station are devided into following:

a)Tool station.

b)Gripper station.

c)Stand station.

d)Miscellineous Station.

• Tool stations:

a)Geo Fixtures:

I BIW we conside tack/Geo fixture.In Geo fixture tack welding done  for all parts to be assembled together in that  geo fixture. The Geo fixture defines the geometry of the parts.

All parts must be located in to 2 locating pins. 

The jigs have close accuracy standerd.In case of geo fixture all the machine parts individually should be made with maximum tol.±0.02. Where as pin positonal accuaracy should be less than-0.015.

In geo fixture spots/MIG welding done in such sequence that after taking out from the fixture to achieve the desired accuracy and doesnt get disturb during transportation of geo fixture to respot fixture.

Geo fixture controls the sub-assembly accuracy in all the 3-AXIS.

b) Re-spot fixture: 

In BIW we consider Re-spot fixtures , the remaining spots/tacks are completed in this fixture.              Suppse in asembly  we need 50 weld tacks. One station we can not complete all the spots because it will take more time & another station relative to the assembly will be ideal condition.

In this type of case, we carefull choose weld tack points which will defines the geometry of the parts & assembly will not get deformed after opening the clamping or in transportion due to welding stresses.

The remaining weld tacks completed in re-spot welding station as per needed. by performing this kind of operation   no station will be ideal hence use Respot station.

Respot fixture also very close postional accuracy. Re spot jig pin accuracy will be 0.028mm.

c) Marriege fixture:

As name suggest the marriege of different assemblies carried out in this fixture.

In different zones of assembly line different assemblies completed like under body,side body, front body, Rear body etc.

After all this parts comes to the station where this all parts get assembled together by using various techniques like welding , gluing & Reveting. this station called marriege station.

d) Framer station: 

Framer station in next station to marriege station

In the faramer fixture the roof is atached to the out put of the marriege fixtyure and it form like a frame hence it called as framer staion.

e)Checking fixture:

This are used to check the assemblies and the parts.

It can be guage type , fixed type or automated type.

Checking guage is a tool where as fix the part and check the dimesion, repaeratability .   

Fixed type checking fixture is used where fixed the part with clamps & Pins measued diminsion with CMM. which measured different coordinates of different points of assembly. the compared with CAD data and compare it.

2) Grippers:

Gripper is a object which hold the workpice and manipulate.the easy way of undertainding is human hand.

Gripper is the just  one part automated system. Gripper is attached to Robot or the part to holding.

differetnt types of grippers following:

a)Material handling gripper:

This gripper is used for pick the assembly from one station and drop the assembly to another station.

b)Process Grippers:

this grippers are used for specific prcosses carried out like gluing, Welding & reveting etc..in addition with material handling.

c)Combo gripper:

Combo grippers are the on which carry out multiple task where as material handling as well as process such as welding, gling and reveting etc.. Weld gun +Gripper.

d)Dual gripper:

This are 2 sided grippers. its used for when one part on LH side & one part on RH side. It can handle material from one station to another station.

Grpper +Gripper

3)Stands:

Stands are used to hold the parts when not in use & also used to mount some parts.

Different types of stands:

a) Pedestal stand :

Weld gun is mounted on fixed stand which is mounted on the floor permanantly.the gripper can carry the panel under stand to do the opeartion.

b)Gluing & sealer stand:

Gliung gun and sealer gun fixed to welded or grouted peramanantly.

c) Docking stand: