20-10-2016, 12:05 PM
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Abstract
Body shop is a place where the assembly of automobile body parts takes place with the help of direct welding techniques. About 85% of the joining processes are done by the using spot welding guns/machines. Body shop is divided into 2 areas namely
1. Body Assembly
2. Body Finishing Area.
Any variation in output of the product will be due to a change in the process or input provided. Spot welding is a sheet metal joining process in which parts to be welded are held together under pressure by electrodes. When the current is applied, resistance in the interface of sheets causes coalescence only at the contact point (spot) and forms a joint.
The objective of my internship is to know about the industrial flow process and to study about Jeeto body shop process.
WHAT IS BODY?
The body is a combination of various sheet metal parts in different shapes which is in accordance with the design. Steel is generally used to make automotive bodies, it’s used because of its general availability, low cost, and good workability. Different parts are joined together at various sections by means of welding. Spot welding is used for joining sheet metals and to give good quality, strength to the body.
The tool used for the spot welding is the portable spot welding guns. The body of an automobile is categorized according to the number of doors, the arrangement of seats, and the roof structure.
ASSEMBLY LINE:-
An assembly line is a manufacturing process (most of the time called a progressive assembly) in which parts (usually interchangeable parts) are added to a product in a sequential manner to create a finished product much faster than with handcrafting-type methods.
CONCEPT OF ASSEMBLY LINE:-
Assembly lines are designed for the sequential organization of workers, tools or machines, and parts. The motion of workers is minimized to the extent possible. All parts or assemblies are handled either by conveyors or motorized vehicles such as forklifts, or gravity, with no manual trucking. Heavy lifting is done by machines such as overhead cranes or forklifts. Each worker typically performs one simple operation.
According to Henry Ford:
The principles of assembly are these:
(1) Place the tools and the men in the sequence of the operation so that each component part shall travel the least possible distance while in the process of finishing.
(2) Use work slides or some other form of carrier so that when a workman completes his operation, he drops the part always in the same place—which place must always be the most convenient place to his hand—and if possible have gravity carry the part to the next workman for his operation.
(3) Use sliding assembling lines by which the parts to be assembled are delivered at convenient distances.
PURPOSE OF BODY:-
The purpose of the car body is to:
1. Enclose the vehicle for passenger comfort and safety.
2. Create minimal resistance as it cuts through the air.
3. Act as a solid mount for other elements in the car.
Welding
Welding is a process that joins materials usually metals or thermoplastics, by causing fusion, which is distinct from lower temperature metal-joining techniques such as brazing and soldering, which do not melt the base metal. In addition to melting the base metal, a filler material is often added to the joint to form a pool of molten material that cools to form a joint.
Types of Welding:
Arc Welding (MIG Welding)
Resistance Welding
Stud Welding
Seam Welding
Spot Welding:
Spot welding is one of the oldest welding processes. It is used in a wide range of industries but notably for the assembly of sheet steel vehicle bodies. This is a type of resistance welding where the spot welds are made at regular intervals on overlapping sheets of metal. Spot welding is primarily used for joining parts that are normally up to 3 mm in thickness. Thickness of the parts to be welded should be equal or the ratio of thickness should be less than 3:1. The strength of the joint depends on the number and size of the welds. Spot-weld diameters range from 3 mm to 12.5 mm.
How spot welding works
Spot welding is one form of resistance welding, which is a method of welding two or more metal sheets together without using any filler material by applying pressure and heat to the area to be welded. The process is used for joining sheet materials and uses shaped copper alloy electrodes to apply pressure and convey the electrical current through the workpieces. In all forms of resistance welding, the parts are locally heated. The material between the electrodes yields and is squeezed together. It then melts, destroying the interface between the parts. The current is switched off and the "nugget" of molten materials solidifies forming the joint.
To create heat, copper electrodes pass an electric current through the workpieces. The heat generated depends on the electrical resistance and thermal conductivity of the metal, and the time that the current is applied.