Industry has always been attempting for increased production, improved quality of products and enhanced production efficiency. And in its pursuit for these objectives, industry has developed a tendency to transfer more and more human activities into power-operated mechanized activities. This led to the development of mechanization of manufacturing processes in which human inputs were replaced more and more by a variety of special machines and mechanical aids, but the control of the process was, however, done by human beings using either electrical or electronic system. Mechanization of a particular process means the transfer of human skills and activities involved in a particular process to machines or mechanized operations.
The process, however, continued to be controlled or monitored by the operator. The aim of mechanization had been to reduce process time, element of labour and cost, human fatigue and risks, and to improve the production rate and quality. Automation is another term used in relation to mechanization and represents a higher degree of mechanization in which most or all of the activities involved in manufacturing a product (including the control of process) are performed with the help of automatic machines without the direct participation of a human being (barring a few operations such as change of tooling when there is a change of product, readjustment for correction, etc.).
Automation may be partial automation or full automation. In partial automation, replacement of human activities by automatic means is done only partially, whereas in full automation, human involvement is totally eliminated and the process is carried out and controlled through automatic means along with a proper feedback system. Therefore, the full automation includes all aspects of manufacturing such as loading and unloading, production, material handling, services, handling of information, sensing and correction of errors, process control, inspection, etc.
Latest trend in automation is computer integrated manufacturing, i.e. to use computers not only for actual manufacturing but also for designing the product, planning for manufacturing and performing all business-related functions.
Automatic machines are those machines in which both the workpiece handling and the metal casting operations are performed automatically. Operations right from feeding of the stock to clamping, machining and even inspection of the workpiece are carried out automatically.
Types of automatic machines given in the following cover only the most popular types.
(a) Single spindle: cutting off, Swiss type, automatic screw type.
(b) Multiple spindle: cutting off bar, drilling, forming, bar, special type.
(ii) Transfer machines
(iii) Machining centres
The automatic lathes have already been discussed under Section 6.16. The transfert machines and machining centres will be discussed in the following.
Justification for Adopting Automation
- · Where adoption will enable maximum utilization of machines, advanced production methods, higher production rates and improved quality standards.
- · Where adoption will lead to large scale saving in labour cost and tooling cost.
- · Where environment is highly injurious to human beings (such as dealing with radioactive substances).
- · Where operation is rapid and complex and difficult for human beings to perform safely and easily. Where adoption will facilitate the use of a large number of standard components and subassemblies.
- · Where adoption will enable the use of Group Technology in the manufacture of parts having similarities in design and production thus affecting substantial reduction in the number of types and sizes of cutting and measuring tools.
Advantages of Automation
- · Reduced production cost
- · Increased productivity Human safety improved
- · Reduced human fatigue and risks
- · Several machines can be looked after by one operator
- · Less floor area required and number of machine tools reduced as with machining centre (discussed later)
- · Effective control on production process
- · Increased overall profit.
- · Reduced maintenance requirement
- · Due to the use of standard parts and assemblies, inventory requirement reduced
- · Reproducibility of components ensured in mass production
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