SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING UNrSⅨX MANUFACTURING PROCESSES process过程 LESSON ONE MACHINING PROCESSES 工艺规程方法 In a sense The manufacturing (or production) process 从某种意义上说 of a factory in a broad sense, is the sum total of sum total总数 separate processes involved in the conversion of raw materials or semi-finished products into final as far as至于 products. As far as a factory is concerned,its‖bank空白的 products can be blanks, finished parts 毛坯,坯件 mec hanisms, units or end products. The raw‖lpat部分,零件 materials or semi-finished products used for mechanism manufacturing the products are often produced‖机构,机理 and supplied by other factories. Sometimes theunit单位,部件 products of the factory need to be further processed by other factories before they become the end products
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING UNIT SIX MANUFACTURING PROCESSES LESSON ONE MACHINING PROCESSES process 过程 工艺规程,方法 The manufacturing (or production) process of a factory, in a broad sense, is the sum total of separate processes involved in the conversion of raw materials or semi-finished products into final products. As far as a factory is concerned, its products can be blanks, fi ni shed parts, mechanisms, units or end products. The raw materials or semi-finished products used for manufacturing the products are often produced and supplied by other factories. Sometimes the products of the factory need to be further processed by other factories before they become the end products. in a sense 从某种意义上说 sum total 总数 as far as 至于 blank 空白的 毛坯，坯件 part 部分，零件 mechanism 机构，机理 unit 单位，部件
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING The manufacturing (production) process cost accounting includes not only processes acting directly upon 成本会计, the manufactured objects, but also preparatory成本核算 processes(such as production planning, process planning, production scheduling, tooling preparation, etc and auxiliary processes(such as equipment maintenance, inter-shop material and workpiece handling, cutting tool sharpening narrow sense quality inspection,, production statistics, cost‖狭义 accounting, etc.) The processes, acting directly upon the manufactured objects, change the shape, dimensions and properties of raw materials or semi-finished products, or assemble parts into final products. These processes are manufacturing (or production) processes in a narrow sense
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING The manufacturing (production) process includes not only processes acting directly upon the manufactured objects, but also preparatory processes (such as production planning, process planning, production scheduling, tooling preparation, etc.) and auxiliary processes (such as equipment maintenance, inter-shop material and workpiece handling, cutting tool sharpening, quality inspection, production statistics, cost accounting, etc.) The processes, acting directly upon the manufactured objects, change the shape, dimensions and properties of raw materials or semi-finished products, or assemble parts into final products. These processes are manufacturing (or production) processes in a narrow sense. cost accounting 成本会计， 成本核算 narrow sense 狭义
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING There are various manufacturing processes casting铸造 used for converting raw materials into finishedforging f#xit parts. These processes include casting, forging, welding Htk welding, punching, forming, machining, heat- punching it. treatment, plating, coating, and so on. Among forming成形加工 them, the machining process plays an machining切削加工 important role in the manufacture of parts heat- treatment热处理 The machining process of a part may plating电镀 include various machining operations, such as coating i a turning, milling, drilling, grinding, broaching operation操作,工序 gear-cutting, etc. depending on the required turning车削 shape, dimensions, accuracy and surface milling铣肖 quality of the part. In order to ensure the drilling fijl quality of a completed part. well-planned grinding磨削 processes documents are necessary broaching拉削 etc.= et cetera
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING There are various manufacturing processes used for converting raw materials into finished parts. These processes include casting, forging, welding, punching, forming, machining, heattreatment, plating, coating, and so on. Among them, the machining process plays an important role in the manufacture of parts. The machining process of a part may include various machining operations, such as turning, milling, drilling, grinding, broaching, gear-cutting, etc. depending on the required shape, dimensions, accuracy and surface quality of the part. In order to ensure the quality of a completed part, well-planned processes documents are necessary. casting 铸造 forging 锻造 welding 焊接 punching 冲压 forming 成形加工 heat-treatment热处理 machining 切削加工 plating 电镀 coating 油漆 operation 操作,工序 turning 车削 milling 铣削 drilling 钻削 grinding 磨削 broaching 拉削 etc.= et cetera
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING After a new product is designed planning the processes for its component parts is the first step of the preparatory work for manufacturing. The planned process documents serve as the basis and initial data for all other preparatory work, and the rules and regulations for production operations, the quality of process plans influences directly the degree of complexity of the preparatory work for manufacturing, the time length of the preparatory stage, the quality of parts and products manufactured, the degree of complexity of production scheduling and operations sequencing, the makespan of parts and products, and the production costs Hence process planning is of key importance to manufacturing 制造时间
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING After a new product is designed, planning the processes for its component parts is the first step of the preparatory work for manufacturing. The planned process documents serve as the basis and initial data for all other preparatory work, and the rules and regulations for production operations, the quality of process plans influences directly the degree of complexity of the preparatory work for manufacturing, the time length of the preparatory stage, the quality of parts and products manufactured, the degree of complexity of production scheduling and operations sequencing, the makespan of parts and products, and the production costs. Hence process planning is of key importance to manufacturing. 制造时间
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING Often there exist alternatives of process plans for manufacturing a part. The quality of a process plan should be evaluated from a technological as well as an economical standpoint. A good process plan not only ensures the required quality of manufactured parts, but also reduces the production cost. In process planning, a comprehensive analysis of part structure, material and technical specifications, production volume and manufacturing conditions must be made, so as to properly make all the decisions related to the planning of the process Many decisions should be made in machining process planning Selection of the blank and its manufacturing method Selection of machining methods for part sur faces Determination of operations sequence Determination of workpiece setting method for each operation
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING Often there exist alternatives of process plans for manufacturing a part. The quality of a process plan should be evaluated from a technological as well as an economical standpoint. A good process plan not only ensures the required quality of manufactured parts, but also reduces the production cost. In process planning, a comprehensive analysis of part structure, material and technical specifications, production volume and manufacturing conditions must be made, so as to properly make all the decisions related to the planning of the process. ﹡Many decisions should be made in machining process planning. ﹡Selection of the blank and its manufacturing method. ﹡Selection of machining methods for part surfaces. ﹡Determination of operations sequence. ﹡Determination of workpiece setting method for each operation
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING Selection of machining equipment and tooling for operations Determination of operating procedure for each operation k Determination of operational dimensions and tolerances for machining operations k Selection of machining conditions and determination of time Standards Of each operation Composition of Machining processes A machining process is made up of a number of operations through which raw materials or blanks are transformed into parts The basic components of machining processes are operations An operation is a complete portion of the machining process for cutting, grinding, or otherwise treating, a workpiece (or seyeral workpieces simultaneously)at a single workplace. An operation is accomplished by one or several operators(until they start to repeat the same procedure for the next workpiece or next set of workpieces in the batch) 批[ work piec件
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING ﹡Selection of machining equipment and tooling for operations. ﹡Determination of operating procedure for each operation. ﹡Determination of operational dimensions and tolerances for machining operations. ﹡Selection of machining conditions and determination of time standards of each operation. Composition of Machining Processes A machining process is made up of a number of operations through which raw materials or blanks are transformed into parts. The basic components of machining processes are operations. An operation is a complete portion of the machining process for cutting, grinding, or otherwise treating, a workpiece (or several workpieces simultaneously) at a single workplace. An operation is accomplished by one or several operators (until they start to repeat the same procedure for the next workpiece or next set of workpieces in the batch). 一批 work piece 工件
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING The operation is characterized by the unchanged equipment, unchanged workpiece and continuity. For example, a batch of workpieces is machined first on a lathe, and then on a milling machine. Obviously, two operations are involved. Fig. 6. 1 shows the machining of the center hole and recess of a recess退刀槽 flange. f a batch of the workpieces areflange法兰盘 machined consecutively by drilling, boring‖bore镗孔 holes and boring recesses with three different cutting tools at the same workplace(e.g.a lathe), it is a single operation. If these holes are drilled on a lathe and then bored on another, the machining of the workpieces will consist of two operations instead of one
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING The operation is characterized by the unchanged equipment, unchanged workpiece, and continuity. For example, a batch of workpieces is machined first on a lathe, and then on a milling machine. Obviously, two operations are involved. Fig. 6.l shows the machining of the center hole and recess of a flange. If a batch of the workpieces are machined consecutively by drilling, boring holes and boring recesses with three different cutting tools at the same workplace (e.g. a lathe),it is a single operation. If these holes are drilled on a lathe and then bored on another, the machining of the workpieces will consist of two operations instead of one. recess 退刀槽 flange 法兰盘 bore 镗孔
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING The contents of an operation include all activities directl related to machining(or other treatment ), as well as all necessary handling and auxiliary motions. An operation is the basic unit of a manufacturing process. An operation element is a component of an operation, which is performed without changing the cutting 步 tool (or a group of simultaneously-used cutting tools), the machined workpiece surface, and cutting speed and feed. If one of them changes, it becomes a different operation element. figure For example, the hole machining operation shown in Fig 6.1 consists of three operation elements which are first, drilling of the hole; second, boring of the hole; and third, boring of the recess. This is because, in each of the three operation elements either the changing of the cutting tool or the machined sur face occurs If the hole is rough bored first and then, after changing the cutting speed and feed, finish bored, the operation would consist of four operation elements
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING The contents of an operation include all activities directly related to machining (or other treatment), as well as all necessary handling and auxiliary motions. An operation is the basic unit of a manufacturing process. An operation element is a component of an operation, which is performed without changing the cutting tool (or a group of simultaneously-used cutting tools), the machined workpiece surface, and cutting speed and feed. If one of them changes, it becomes a different operation element. For example, the hole machining operation shown in Fig. 6.l consists of three operation elements which are first, drilling of the hole; second, boring of the hole; and third, boring of the recess. This is because, in each of the three operation elements, either the changing of the cutting tool or the machined surface occurs. If the hole is rough bored first and then, after changing the cutting speed and feed, finish bored, the operation would consist of four operation elements. 工 步 figure
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING In order to obtain higher machining efficiency, several simple operation elements are sometimes combined into one complex operation element. In a complex operation element, several cutting tools are simultaneously used to machine different workpiece surfaces. Fig. 6.2(a) shows the machining of two plane sur faces using two milling cutters Fig. 6.2(b)illustrates the machining of a workpiece on a lathe equipped with a turret. This has been commonly used in 转塔一 many turret lathes, automatic lathes, and numerically controlled turning centers for increased productivity. When it is necessary to remove a thick layer of material from the workpiece and it cannot be done in a single cut, an operation element can be divided into several passes (or cuts). A pass or cut, is a single cutting motion of the cutting tool in the direction of the feed along the machined surface, without changing the set-up of the tool or the cutting speed or feed
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING In order to obtain higher machining efficiency, several simple operation elements are sometimes combined into one complex operation element. In a complex operation element, several cutting tools are simultaneously used to machine different workpiece surfaces. Fig.6.2 (a) shows the machining of two plane surfaces using two milling cutters. Fig.6.2 (b) illustrates the machining of a workpiece on a lathe equipped with a turret. This has been commonly used in many turret lathes, automatic lathes, and numerically controlled turning centers for increased productivity. When it is necessary to remove a thick layer of material from the workpiece and it cannot be done in a single cut, an operation element can be divided into several passes (or cuts). A pass, or cut, is a single cutting motion of the cutting tool in the direction of the feed along the machined surface, without changing the set-up of the tool or the cutting speed or feed. 转 塔
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING As an example, if there is a big difference between the diameters of the hole and the recess shown in Fig 6.1, the boring of the recess must be accomplished in several passes. In each pass, a layer of material is removed. However, all these passes are part of the recess machining operation element since none of the cutting tool, machined sur face, cutting speed or feed changes There are many elementary handling operations for the operator to accomplish a given operation, an operation element or a pass(for example, loading and unloading the workpiece, changing the tool, starting the machine tool advancing the tool to approach the workpiece, measuring the machined surface, etc. ) Among them, the set-up of the workpiece plays an important role
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING As an example, if there is a big difference between the diameters of the hole and the recess shown in Fig.6.1, the boring of the recess must be accomplished in several passes. In each pass, a layer of material is removed. However, all these passes are part of the recess machining operation element, since none of the cutting tool, machined surface, cutting speed, or feed changes. There are many elementary handling operations for the operator to accomplish a given operation, an operation element or a pass (for example, loading and unloading the workpiece, changing the tool, starting the machine tool, advancing the tool to approach the workpiece, measuring the machined surface, etc.). Among them, the set-up of the workpiece plays an important role