Introduction
Manufacturing study is a general term for those processes and techniques which are used in all its context, some factors as measurement and marking out instruments, machines, operators, designers and management which lead to the investigate the desired aim of manufacturing processes. Manufacturing is the process of converting raw materials into products, it consist of the design of the product and the selection of raw materials so the sequence process to the product will be manufactured. It is the backbone of any industrialised country and the importance of manufacturing is economic activity. A country ?s level of manufacturing activity is directly related to its economic health. Generally, the higher the level of manufacturing activity in a country is the higher the standard of living of its people.
Manufacturing processes can be divided into two groups, primary manufacturing processes and secondary manufacturing processes. Primary processes provide the raw materials or the basic shape and size to the work as casting, forming, powder metallurgy, etc. Secondary manufacturing processes are aims to obtain desired product with final shape and size with exact dimension of surface characteristics, as materials removal processes. All of the products mentioned are made by various processes that we call manufacturing as Casting or Moulding, Machining or Cutting, Forming or Deforming, Assembly etc.
In order to create a competitive manufacturing system, it must be a well-established cooperation between human and the machine, which is the basis of the relationship between technology and an operator. The human participation as a successful management of equipment and organization of work, in other word the human participation in manufacturing processes is contributing an essential contribution to achieving the optimal aim of this relationship.
Figure1. Relation between the Human and Machine
The mechanical or chemical steps used to create any product with large quantity are termed production processes, generally involves the use of raw materials, machinery and human power to create a final products with exact dimensions and desired shapes. In addition to the process for shaping of raw materials, finishing operations are used to obtain the desired final quality. These operations include: Cleaning, Painting, Plating, Polishing, Deburring, Heat treatment etc.
Measuring & Marking out& Hand Tools
Measurement a method to determine quantity, capacity, or dimension, in other word, it is values made meaningful by quantifying into specific units. Measurements act as labels which make those values more useful in terms of details. Several systems of measurement exist, each one comprising units whose amounts have been arbitrarily set and agreed upon by specific groups, but International System is accepted all over the world as the standard system for use in science. Measuring is taken from a baseline or datum surface. A lot of tasks require two datum surfaces at right angles to each other. Smoothing off will turn a rough, newly-sawn edge into a datum surface.
• To create a datum surface on wood, a plane is used.
• To create a datum surface on metal and plastics, a flat file or hand file is used.
A steel rule or straight edge is used to check that a surface is flat, and a try square is used to check a surface is at right angles to another surface
Marking out or layout is the process of transferring a design or pattern to a work piece, as the first step in the manufacturing process. Or transfer of shapes and lines onto the material, as guides for cutting, bending or shaping them. Accurate marking out is essential if the different parts of the product are to fit together properly. It is performed in many industries or hobbies although in the repetition industries the machine s initial setup is designed to remove the need to mark out every individual piece.
Hand Tools
Bench Vice
A bench vice (figure 19) is the device for holding the workpiece where most hand processes to be carried out. The body of the vice is made of cast iron while the two clamping jaws are made of hardened tool steel. Some bench vice has a swivel base, which can set the workpiece at an angle to the table. The vice height should be correct ergonomically. Vice clamps, made of copper are fitted over the vice jaws when holding finished work to avoid damage to the finish surfaces.
Care of Vices
a. Do not direct impact the vice body by the hammer.
b. Light hammering can be done on and only on the anvil of the vice.
c. To avoid over clamping, the handle of the vice should be tightened by hand only
Figure19. Bench Vice
Files
Files are the most important hand tools used for the removal of materials. They are made of hardened high carbon steel with a soft tang . to which a handle can be fixed. Files are categorised as follows:-
Length - measured from the shoulder to the tip. Shape - the cross-sectional profile. Grade - the spacing and pitch of the teeth. Cut - the patterns of cutting edge.
Figure 20. File
Save Edge; there is edge without teeth on one side of the hand file. The purpose of the save edge is to avoid damage of work.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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