Week 1:- Introduction to BiW and Fixtures Challenge
Que 1st Ans:-
A]
BIW - Body in White refers to the welded sheet of metal components that form the vehicle structures to which the other components will be named married i.e Engine, Chassis exterior and interior trim.
Body in white refers to the stage in Automotive design or Automobile Manufacturing in which the car body sheet metal has been assembled or designed but before the components have been added. The stage in Automotive design or Automobile manufacturing is in which the car body sheet metal components are been ass3mbled by the welded and by other joining processes.
B]BIW stations are classified into four types. They are TOOLS.
Framer Tool etc
GEO TOOL
RESPOT TOOL
MARRIAGE (OR) HEMMING TOOL
FRAMER TOOL
CHECKING TOOL
Que 2nd Ans:-
BIW Nomenclatures
A- Inner Wing Panel
B- Upper wing Panel
C- Suspension tower
D- Upper 'A-Pillar
E- Windshield header rail
F- Roofstiffner
G- Rear Parcel tray
H- Side roof rail
I- Backlight frame
J- 'C' Pillar
K-'D' Pillar
L- Rear Quater Panel
M-Boot Floor Panel
N- Rear Seat Back Panel
O- Rear seat Panel
P- 'B' Pillar
Q- Floor Panel
R- Sill
S- Lower 'A-Pillar
T- Dash Panel
U- Engine(Longitudinal rail)
V- Front Bumper
W- Spare wheel Well
X- Center (Longitudial) tunnel
Y- Rear Seat Cross-Beam
Z- Rear Suspension support beam
Que 3rd Ans:-
Fixtures - A fixture is a device that holds a workpiece to be processed by using the 3-2-1 principle.
In general, a welding fixture tool consists of a number of units together to hold the car panel and is mounted on a base unit. Welding fixtures are normally designed to hold and supported the various components to be welders. It is necessary to support them in a proper location that is capable of preventing distortion in the workpiece during welding for thus the locating elements needed to be placed carefully clamping has to be light but firm.
Types of Fixtures
1] Production Fixture - Mass production purpose.
2] Pre Production operation fixtures(PPO) - For the initial batch operation to study the feasibility.
3] Checking Fixtures - For car Panel Geometric inspection purposes.
Que 4th Ans:-
Principle of Fixture Design
For a fixture designer, the major portion of design time is spent on how to locate the workpiece in the fixture.
For any free body there are 12 degrees of freedom as below:-
6 translation design of freedom
+X, -X, +Y, -Y, +Z, -Z.
And 6 rotaional degree of freedom-
- Clockwise around X-axis.
- Anticlockwise around X-axis.
- Clockwise around Y-axis.
- Anticlockwise around Y-axis.
- Clockwise around Z-axis.
- Anticlockwise around Z-axis.
You must fix all the 12 degrees of freedom in order to locate the workpiece in the fixture. So, 12 degrees of freedom of the workpiece needs to be fixed & thus we can achieve zero degrees of freedom for the work piece.
Que 5th Ans:-
1. Geo station:
In this station geometry of two parts are fixed. it can be either using welding or riveting. In this station precision and geometry of the finished product is defined Locating pins have a closer tolerance of 0/-0.15.
Suppose the hole dia of the panel is 16mm then the pin dia minimum can be 15.85. The diameter of locating pins should be lesser than the panel hole dia. So Tolerance in locating pin is given in negative value.
2. Respot Station :
Once the product comes out of the Geo Station and there are left out spots where spot welding or riveting is to be done. then it is moved to another station, that station is called Re-spot station.
These left out spots may be due to clamp plan, cycle time, robot reachability or any other various reasons. In this station, pins have tolerance up to 0/-0.28.
3. Pedestal Station :
In this station, a Pedestal gun is mounted on a tool and the panel is manipulated manually or by the robot to weld the panels.
Pedestal station is generally a Re spot station. Re spot station and Pedestal station, both perform the same kind of operation. but to decide whether to go for a pedestal or a re-spot station some parameters needs to consider like cycle time, floor space, no. of welds, clamp plan, or size of the panel.
4. Loading Station :
This station is used for loading of the panel and the same station is used to change the orientation of the if it is required in the upcoming station. Sometimes this station is used when Robots are unable to transfer panels from one station to another.
5. Buffer Station :
This station is used to make the balance between the process. Some stations carry out processes in lesser time as compared to their respective stations. In that case, panels can be stored in one station so that the assembly line process remains smooth.
6. Sealer Station :
In this station, the Sealant application is carried out. This process can be carried out manually or by using robots. Sealer is used in between two panels so that panels do not flatter due to friction.
7. Marriage Station :
In this Station, inner and outer panels are joined. In this station to avoid the impression on the outer panel(A-class surface), copper strips are used in between the weld tip and A-class surface.
8. Curing Station :
In this Station product received after sealing application, is kept idle at ambient temperature, which allows the sealant to get dry with better bonding between the panel.
Que 6th Ans:-
NC/MYLARS/FINGER
PLP
BLADE
RISERS
SHIMS
ROUGH LOCATORS
HARDWARE
CMM
UNITS
NUMBER PLATE
CO-ORDINATE PLATE
NAMEPLATE
CLAM ARM
PIVOT
CLASS ' A' SURFACE / SKIN SURFACE
REED SWITCHES
SENSORS