冶金机械专业英语Unit 1-11.docVIP

Contents Unit 1 Introducing to Working Drawings Unit 2 The computer in Design and Graphics Unit 3 Lathes Unit 4 Lubrication Unit 5 From the History Ironmaking and Steelmaking Unit 6 Raw Materials for the Production of Iron Unit 7 The Blast Furnace Plant Unit 8 Raw Materials of Steeling Unit 9 LD Practice Unit10 Continuous Casting of Steel Unit11 Rolling Unit 1 Introducing to Working Drawings Working drawings are the drawings from which a design is implemented. All principles of orthographic projection and techniques of graphics can be used to communicate the details of a project in working drawings. A detail drawing is a working drawing of a single part (or detail) within the ser of working drawings. Specifications are the written instructions that accompany working drawings. When the design can be represented on a few sheets, the specifications are usually written on the drawings to consolidate the information into a single format. All parts must interact. with other parts to some degree to yield the desired function from a design. Before detail drawings of individual parts are made the designer must thoroughly analyze the working drawing to ensure that the parts fit property with mating parts, that the correct tolerances are applied, that the contact surfaces are properly finished, and that the proper motion is possible between the parts. Much of the work in preparing working drawings is done by the drafter, but the designer, who is usually an engineer, is responsible for their correctness. It is working drawings that bring products and systems into being. Working drawings are legal contracts that document the design details and specifications as directed by the engineer. Therefore drawings must be as clear, precise, and thorough as possible. Revisions and modifications of a project at the time of production or construction are much more expensive than when done in the preliminary design stages. Poorly executed working dr