INTRODUCTION

Manufacturing is the backbone of any industrialized nation.Manufacturing and technical staff in industry must know the various manufacturing process,materials being processed,tools and equipments for manufacturing different componenets 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 that 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 organisation.

The complete understanding of basic manufacturing processes and workshop technology is highly difficult for one to claim experties over it.The study deals with several aspects of workshop practices also for imparting the basic working knowledge of the different engineering materials, tools , equipments ,manufacturing processes, basic concepts of electro-mechanical 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 shops in an industrial environment.It also describes and demonstrate 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.

MANUFACTURING ENGINEERING

Manufacturing is derived from the Latin word manufactus,means made by hand.In modern context it involves making products from raw materials 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,and computerized numeric control (CNC)
  6. Jigs and Fixture
  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)

PRODUCTION PROCESS

It is the process followed in a plant for converting semi-finished products or raw materials into finished products.The art of converting raw materials into finished products with application of different types of tools, equipments, machine tools, manufacturing set ups and manufacturing process ,is known as production.Generally there are three types of production system that are given as under.

1.Job production

2.Batch production

3.Mass production

Job production comprises of an operator or group of operators to work upon a single job and complete it before proceeding to the next similar or different job.The production requirement in the job production system is extremely low.It requires fixed type of layout for developing same products.

Manufacturing of products (less in number say 200 to 800) with variety of similar parts with very little variation in size and shape is called batch production.Whenever the production of batch is over, the same manufacturing facility is used for production of other batch product or items.The batch may be for once or of periodical type or of repeated kinds after some irregular interval. Such manufacturing concepts are leading to GT and FMS technology.Manufacturing of products in this case requires process or fuctional layout.

where as mass production involves in large number of identical products (say more than 50000) that needs line layout type of plant layout which is highly rigid type and involves automation and huge amount of investment in special purpose machine to increase the production.

PROCESS PLANNING

Process planning consists of selection of means of production (machine-tools, cutting tools, 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 action of operator. It includes the calculation of the machining time, as well as the required skill of 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.Althogh these concepts may also be extended to other process such as casting, forging sheet matal forming, assembling and heat treatment as well.

CLASSIFICATION OF MANUFACTURING PROCESS

For producing of products materials are needed. It is therefore important to know the characteristics of the available engineering materials. Raw materials used manufacturing of products, tools, machine and equipments in factories or industries are extracted from Ores. The ores are suitably converted the metal into a molten from by reducing or refining processes in foundries. This molten is poured into moulds for providing commersial castings, called ingots. Such ingots are then processed in rolling mills to obtain market from of material supply in form of bloom, slabs and rods. These forms of material supply are further subjected to various manufacturing processes for getting usable metal products of different shapes and sizes in various manufacturing shops. All these processes used in manufacturing concern for changing the ingots into usable products may be classified into six major groups as primary shaping processes, secondary machining processes, metal forming processes, joining processes, surface finishing processes and processes effecting change in properties.These are discussed as under.

PRIMARY SHAPING PROCESSES

Primary shaping processes are manufacturing of a products 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. Casting 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 mattalic moulds to obtain the casting. Thus the intricate shapes can be manufactured. Typical examples of 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 undergo 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.

SECONDARY OR MACHINING PROCESSES

As large number of components require further processing after the primary processes. These components are subjected to one or more number of machining operations in machine shops, to obtain the desired shape nd dimensional accuracy on flat and cylindrical jobs. Thus, the jobs undergoing these operations are the roughly finished products received through primary shaping processes. The process of removing the undesired or unwanted material from the workpiece or component to produce a required shape using cutting tool is knwon as machining. This can be done by a manual process or by using a machine called machine tool (traditional machines namely lathe, milling machine, drilling, shaper, planner, slotter). In many cases these operations are mainly required for achieving dimensional accuracy and a very high degree of surface finish. The secondary processes require the use of one or more machine tools, various single or multi-point cutting tools (cutters), jobs holding devices, marking and measuring instruments, testing devices and gauges etc. The example of parts produced by machining processes includes hand tools machine tools instruments, automobile parts, nuts, bolts and gears etc. Some of the common secondary or machining processes are_____

(1) Turning, (2) Threading, (3) Knurling, (4) Milling, (5) Drilling, (6) Boring, (7) Planning, (8) Shaping, (9) Slotting, (10) Sawing, (11) Broaching, (12) Hobbing, (13) Grinding, (14) Gear cutting, (15) Threading cutting.

METAL FORMING PROCESSES

Forming processes encompasses a wide variety of techniques, which make use of suitable force, pressure or stresses, like compression, tension and shear or thier combination to cause a permanent deformation of the raw material to impart required shape. These processes are also known as mechanical working processes and are mainly classified into two major categories i.e, hot working processes and cold working processes. In these processes, no material is removed, however it is deformed and displaced using suitable stresses like compression, tension, and shear or combined stresses to cause plastic deformation of the materials to produce required shapes. Such processes lead to production of directly usable articles which include kitchen utensils, rods, wires, rails, cold drink bottle caps, collapsible tubes etc. Some of the important metal forming processes are.

HOT WORKING PROCESSES

(1) Forging, (2) Rolling, (3) Hot spinning, (4) Extrusion, (5) Hot drawing

COLD WORKING PROCESSES

(1) Cold forging, (2) Cold rolling, (3) Cold heading, (4) Cold drawing, (5) Wire drawing, (6) Stretch forming, (7) Sheet metal working process, punching, lancing, notching, coining, squeezing, deep bending etc.