25-08-2017, 09:32 PM
introduction to basic manufacturing processes and work shop technology
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INTRODUCTION
Manufacturing is the backbone of any industrialized nation. Manufacturing and technical staff
in industry must know the various manufacturing processes, materials being processed, tools
and equipments for manufacturing different components or products with optimal process
plan using proper precautions and specified safety rules to avoid accidents. Beside above, all
kinds of the future engineers must know the basic requirements of workshop activities in
term of man, machine, material, methods, money and other infrastructure facilities needed
to be positioned properly for optimal shop layouts or plant layout and other support services
effectively adjusted or located in the industry or plant within a well planned manufacturing
organization.
The complete understanding of basic manufacturing processes and workshop technology
is highly difficult for any one to claim expertise over it. The study deals with several aspects
of workshops practices also for imparting the basic working knowledge of the different
engineering materials, tools, equipments, manufacturing processes, basic concepts of electromechanical
controls of machine tools, production criteria’s, characteristics and uses of various
testing instruments and measuring or inspecting devices for checking components or products
manufactured in various manufacturing shops in an industrial environment. It also describes
and demonstrates the use of different hand tools (measuring, marking, holding and supporting
tools, cutting etc.), equipments, machinery and various methods of manufacturing that facilitate
shaping or forming the different existing raw materials into suitable usable forms. It deals
with the study of industrial environment which involves the practical knowledge in the area
of ferrous and non ferrous materials, their properties and uses. It should provide the knowledge
of basic workshop processes namely bench work and fitting, sheet metal, carpentry, pattern
making, mould making, foundry, smithy, forging, metal working and heat treatment, welding,
fastening, machine shop, surface finishing and coatings, assembling inspection and quality
control. It emphasizes on basic knowledge regarding composition, properties and uses of
different raw materials, various production processes, replacement of or improvement over
a large number of old processes, new and compact designs, better accuracy in dimensions,
quicker methods of production, better surface finishes, more alternatives to the existing
materials and tooling systems, automatic and numerical control systems, higher mechanization
and greater output.
SCOPE OF STUDY
Today’s competitive manufacturing era of high industrial development and research, is being
called the age of mechanization, automation and computer integrated manufacturing. Due to
new researches in the manufacturing field, the advancement has come to this extent that
every different aspect of this technology has become a full-fledged fundamental and advanced
study in itself. This has led to introduction of optimized design and manufacturing of new
products. New developments in manufacturing areas are deciding to transfer more skill to the
machines for considerably reduction of manual labor. The scope of the subject of workshop
technology and manufacturing practices is a extremely wide as it specifies the need of greater
care for man, machine, material and other equipments involving higher initial investment by
using proper safety rule and precautions. The through and deep knowledge in the course of
study of this important subject is therefore becoming essential for all kinds of engineers to
have sound foundation in their profession. Therefore the course of study of this subject
provides a good theoretical background and a sound practical knowledge to the engineering
students and workshop staff. One should also be aware of the following terms for better
understanding of the scope of the study
MANUFACTURING ENGINEERING
Manufacturing is derived from the Latin word manufactus, means made by hand. In modern
context it involves making products from raw material by using various processes, by making
use of hand tools, machinery or even computers. It is therefore a study of the processes
required to make parts and to assemble them in machines. Process Engineering, in its
application to engineering industries, shows how the different problems related to development
of various machines may be solved by a study of physical, chemical and other laws governing
the manufacturing process. The study of manufacturing reveals those parameters which can
be most efficiently being influenced to increase production and raise its accuracy. Advance
manufacturing engineering involves the following concepts—
1. Process planning.
2. Process sheets.
3. Route sheets.
4. Tooling.
5. Cutting tools, machine tools (traditional, numerical control (NC), and computerized
numerical control (CNC).
6. Jigs and Fixtures.
7. Dies and Moulds.
8. Manufacturing Information Generation.
9. CNC part programs.
10. Robot programmers.
11. Flexible Manufacturing Systems (FMS), Group Technology (GT) and Computer
integrated manufacturing (CIM).
PROCESS PLANNING
Process planning consists of selection of means of production (machine-tools, cutting tools,
presses, jigs, fixtures, measuring tools etc.), establishing the efficient sequence of operation,
determination of changes in form, dimension or finish of the machine tools in addition to the
specification of the actions of the operator. It includes the calculation of the machining time,
as well as the required skill of the operator. It also establishes an efficient sequence of
manufacturing steps for minimizing material handling which ensures that the work will be
done at the minimum cost and at maximum productivity. The basic concepts of process
planning are generally concerned with the machining only. Although these concepts may also
be extended to other processes such as casting, forging, sheet metal forming, assembling and
heat treatment as well.
MANUFACTURING PROCESS
Manufacturing process is that part of the production process which is directly concerned
with the change of form or dimensions of the part being produced. It does not include the
transportation, handling or storage of parts, as they are not directly concerned with the
changes into the form or dimensions of the part produced.
Primary Shaping Processes
Primary shaping processes are manufacturing of a product from an amorphous material.
Some processes produces finish products or articles into its usual form whereas others do not,
and require further working to finish component to the desired shape and size. Castings need
re-melting of scrap and defective ingots in cupola or in some other melting furnace and then
pouring of the molten metal into sand or metallic moulds to obtain the castings. Thus the
intricate shapes can be manufactured. Typical examples of the products that are produced by
casting process are machine beds, automobile engines, carburetors, flywheels etc. The parts
produced through these processes may or may not require to under go further operations.
Some of the important primary shaping processes is:
(1) Casting, (2) Powder metallurgy, (3) Plastic technology, (4) Gas cutting, (5) Bending and
(6) Forging.