Evolution of Manufacturing

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Manufacturing and Production For my first example, I am using motorcycle engines. The first motorcycle engines were steam powered but soon changed to internal combustion engines sourced from ditch-pumps and early aircraft engines all of which were produced in a similar manner. The casting and machining of the casings and cylinders was very primitive but effective. The cavity in the sand is formed by using a pattern (an approximate duplicate of the real part), which are typically made out of wood, sometimes metal. The cavity is contained in an aggregate housed in a box called the flask. Core is a sand shape inserted into the mould to produce the internal features of the part such as holes or internal passages. Cores are placed in the cavity to form holes of the desired shapes. Core print is the region added to the pattern, core, or mould that is used to locate and support the core within the mould. A riser is an extra void created in the mould to contain excessive molten material. The purpose of this is feed the molten metal to the mould cavity as the molten metal solidifies and shrinks, and thereby prevents voids in the main casting. In a two-part mould, which is typical of sand castings, the upper half, including the top half of the pattern, flask, and core is called cope and the lower half is called drag. The parting line or the parting surface is line or surface that separates the cope and drag. The drag is first filled partially with sand, and the core print, the cores, and the gating system are placed near the parting line. The cope is then assembled to the drag, and the sand is poured on the cope half, covering the pattern, core and the gating system. The sand is compacted by vibration and mechanical means. Next, the cope... ... middle of paper ... ...s called the buck-tail. On installation the rivet is placed in a pre-drilled hole. Then the tail is upset (deformed) so that it expands to about 1.5 times the original shaft diameter and holds the rivet in place. To distinguish between the two ends of the rivet, the original head is called the factory head and the deformed end is called the shop head. Bibliography http://www.efunda.com/processes/metal_processing/sand_casting_intro.cfm https://www.amazines.com/Metal_Casting_Techniques_related.html http://dhkites.com/custom2.html http://www.patentstorm.us/patents/6082674/description.html http://books.google.co.uk/books?id=EU2qaouuuzoC&pg=PA22&lpg=PA22&dq=how+are+the+panels+of+airplanes+shaped+and+assembled%3F&source=web&ots=62muPfVCEe&sig=iqlLNnQ0do658ToC9Yz65KnQFSQ&hl=en&sa=X&oi=book_result&resnum=4&ct=result http://www.freepatentsonline.com/2337535.html

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