制造技術(shù)基礎復習基本概念、基本原理英語表達參考

1、制造技術(shù)基礎復習基本概念、基本原理英語表達參考Review the Basic Concepts and Principles of Fundamentals of Manufacturing Technology in EnglishCHAPTER ONE DESIGN FOR MECHANICAL PROCESS PLANNINGSection 1 Basic conceptsProduction procedure of mechanical productsProcess procedure of machiningElements of Process procedure of ma

2、chining 1 sequence 工序；2 installation 安裝；3 station 工位；4 step 工步； 5 pass 走刀Sequence: process procedure that consists of several sequences during which workers operate on the works continuously in the same place;(操作者、加工地、工作對象人為劃分，相對可變)Installation: in a sequence if the work is required to put into posi

3、tion and clamp several times,the part of sequence done in one positioning and clamping is called an installation;(確定）Station: In an installation, by using the indexing or moving device the work is changed its position relatively to the cutting tool. All the tasks done for the work in one machining p

4、osition in an installation is termed as the station;(確定）Step：In one station if the surface cut, cutting tool, velocity, and feed remain unchanged, these working contents are thought of as the step.(加工表面、刀具、切削速度、進給量任一改變均為另一工步）Pass: When the surface of the work is cut for any one time ,such task carri

5、ed out is named as the pass(刀具在加工表面的每一次切削）Processing system: a system that contains the work to be machined, fixture that holds the work in the proper position, cutting tool that machines the work directly, and machine tool that gives the power and provide the movements to accomplish the processing.

6、 In recent years the gauging and measuring is added to the system.Relationship between the batch and the pattern of productionN-program of production, Q-annual turnout of the productn-number of the components a year, -share rate, -waste rate, F -annual working days, A- number of days for inventory,

7、-number of components in a lot(1%)N =QnbNFn =AA Program of production In a period of planning, the turnout of product and schedule to be fulfilled is called program. (計劃期的產(chǎn)量加進度=生產(chǎn)綱領(lǐng)）The turnout in one year planning is named the annual program .B Batch of production At a time, the number of identical

8、 products to be put into production or to be produced is termed as batch of production.(一次投入生產(chǎn)的同一產(chǎn)品的數(shù)量=生產(chǎn)批量）Process planning for machining operations :stipulated document for technological process (機械加工工藝規(guī)程：以工藝文件形式規(guī)定的機械加工工藝過程)Patterns of the process planning for machining Generally speaking, the pro

9、cess planning for machining appears in the form of sheet or card with the same basic content in three patterns:Pattern A: sheet of process procedures(工藝過程卡), a very simple and concise document, usually for single/small batch productionPattern B: sheet of process operation (機械加工工藝卡), often for batch

10、productionPattern C: sheet of process sequence (機械加工工序卡), with detailed and complete contents, frequently for massive productionSection 2 Location and Datum of the work in machiningInstallation and clamping(裝夾）: concerning about the ways in which the work is installed and clamped in the fixture or o

11、n the machine tool, including two aspects, locating(定位定位) and clamping(夾緊夾緊).Locating: the procedure during which the work gains its proper position in the fixture or on the machine tool.Clamping: when the workpiece has gained its correct position in the fixture, it will be subject to the external f

12、orces while being machined. So, to hold or keep the workpiece in the correct position is definitely required, which is called clamping.Six-Point Locating Principles：A cuboid is in cartesian coordinate with six degrees of freedom The six degrees of freedom are three linear movements along the three c

13、oordinate axes, respectively, and three rotations around these coordinate axes In theory, the locating point is the geometric point; in reality, it is something different with its three dimensions. The following are commonly used in workshops.Button locator(支撐釘);Plug(檔銷); Supporting plate（支撐板）; Pin/

14、pin locator （長銷）Button; Cut pin/rhombus pin（削邊銷/菱形銷）; Mandrel（心軸）; V block（形塊）Short V block （短形塊）; Positioning sleeve（定位套）; Fixed/floating conic pin（固定/浮動錐銷）; Center(頂尖（固定/浮動）)Complete positioning :locating with constraint for all six degrees of freedom.Incomplete positioning: locating with constrai

15、nt for less than six degrees of freedom.Under/over-positioning: the number of constraints of degree of freedom is less than that required. Under-positioning ought to be avoided and,Over-positioning: the same degree of freedom is constrained by two or even more constraining points, such situation is

16、called over positioning, which will be allowed occasionally.Datum(基準基準) is the point, line or surface based on which the geometric relation-ships among geometric elements of the object to be worked at are determined. The concept is so important that is may be used for any aspect of production, from

17、design, through manufacturing including X,Y,and Z X, Y, and Zsequences of operation, to the gauging and assemblyTechnological/process datumsSequential datum: on the sequential drawing ,datum that is used in this sequence to determine the size, form, and position of the work after being machined is n

18、amed Sequential datum. The three aspects are supposed to be taken into consideration: the priority of sequential datum is paid to the design datum, that is use the design datum as sequential datum, the selected datum is favorable for the location and the gauging of the work, and if the above require

19、ments are hardly met, the datum used to guarantee the technical conditions.Datum may be classified into two categories,Design datum and Technological datum, according to their functions .I design datum: in design of components, the origin from which ,according to the assembly relationship of the com

20、ponent and the relative relationship of the structural elements of the component itself, the dimensioning is done. These original positions are called design datums .(設計圖紙上零件標注的起始位置設計圖紙上零件標注的起始位置)II technological datum: datum used in the process operations is termed technological datum, which can be

21、 even classified as:Locating datum: datum used for the workpiece to gain its proper position in machining, it directly influences the effectiveness of machining. Locating datum covers Rough datum and Finishing datum.a) Rough datum /Finishing datum : un-machined locating datum, in other word, any loc

22、ating datum used in the first sequence of operation in the manufacturing process planning is the rough datum; finishing datum: machined locating datum.b) additional/auxiliary datum: the specially designed datum in the workpiece because of the requirement of the mechanical process operations.Gauging

23、datum: during and after machining, datum used for measuring and checking the form, position, and error of size , of the workpiece.Assembling datum: in assembling datum adopted to determine the relative positions of the work or the component in the product.Section 3 Design of the routes of machining

24、processes（工藝路線的制定）（工藝路線的制定）Consideration must be taken with the locating datum of the workpiece(定位基準）, the process methods（加工方法）, the order of the processes（加工順序）, heat treatment（熱處理）, testing（檢驗） ， and the related operations（其他工序）. A selection of locating datums(定位基準的選擇)B selection of economic accu

25、racy and process methods of machining（機加的經(jīng)濟精度與方法）C machining routes for the typical surfaces（典型表面的加工路線外圓、孔和平面）D order of sequences（工序順序安排）Selecting rules of rough machining datum:I guarantee the proper relative positions .II guarantee reasonable allocation of the allowance for the surface being mach

26、ined .III facilitate the locating and clamping of the workpiece. For this reason, the selected surfaces as the datums must be to some extent smooth, enough-sized, flasher-free , without other defects such as reservoir and riser or the like. IV the rough locating datum used only for one time (without

27、 repetition)Selecting rules of finishing machining datum:I overlapping principle(基準重合）-datum used as the same as design datumII unifying principle（基準統(tǒng)一）-use the same datum as early and as frequently as possibleIII inter-reference principle（互為基準）-especially used for the high accuracy of relative posi

28、tions of the surfacesIV self-reference principle（自為基準)- for sequence of small roughness, small and even allowance V clamping-facilitating/convenient principle（便于裝夾）-for proper and secure (reliable) locating, simple structure of the clamping device with easy operationEconomic accuracy in machining (經(jīng)

29、濟加工精度經(jīng)濟加工精度)Under the common machining conditions , that is , with facilities and tooling in standard quality, the operators with typical skills, and in rated time ,the machining is done with the relevant accuracy and roughness imparted to the component. Such accuracy and roughness is called the eco

30、nomic accuracy in machining Order of sequences（工序順序安排）a datum first then others; b flat first then others, generally; c the main surfaces first;d rough machining first, followed by finishing machiningCentralized, decentralizes sequences and the Machining stages I rough machining II semi-finishing ma

31、chiningIII finishing machining IV precision, ultra-precision ,and smooth machiningSection 4 Determination of machining allowance, dimensions between sequences, and tolerancemachining allowance: the difference between the size of the blank and that of the component design on drawing the total allowan

32、ce is equal to the sum of material thickness to be removed for every step in the process operation.Sequential allowance: the thickness of metal removal of the cut layer in every sequenceThe relationship between the total allowance and Sequential allowance will be expressed in terms of Zo=Z1+Z2+Zn=CH

33、APTER TWO DESIGN PRINCIPLES OF MACHINE TOOL JIGS AND FIXTURESSection 1 introduction to the machine tool jigs and fixturesFunction, constituents, and classification（夾具的功用，組成和分類）（夾具的功用，組成和分類）Function: the machine tool jig or fixture is a device used in machine tool by which the workpiece obtains and k

34、eeps the proper position relative to the machine tool before and during the workpiece being machined.Constituents of the fixture: Six elements or units of a jig or fixtureI locating elements: for locating the work, such as button locator, base (body), and rhombus.II tool guide: for guiding the tool

35、or adjusting relative position of the tool to the fixture, such as ,tool setting block.III clamping device: for holding the work firmly, such as the bolt, screw, and the heel.IV connecting elements: for determining the position of the fixture on the machine tool and connecting the fixture with the m

36、achine tool ,such as the locating key, and the base.V body: for connecting all the elements and devices as a whole, and through the body the fixture being fixed to the machine tool, such as the base.VI additions: for other purposes ,like indexing, safeguarding, error-avoiding and the like, such as t

37、he stop pin.Classification of the fixture:According to the range of usage, fixtures can generally be classified into six categories : all-purpose, special, all-purpose adjustable and group, composite, transferring fixtures.In accordance with the machine tool on which the fixture is utilized, fixture

38、s can also be nii=1Zclassified into lathe, milling machine, drill, borer, grinder, automatic machine tool, and NC machine tool, fixtures.Based on the power which drives the clamping devices to hold the work firmly in place, fixtures can even be classified into manual, pneumonic, hydraulic, electric-

39、magnetic , and vacuum, fixtures Section 2 Workpiece-location in the fixture * the analysis and calculation of locating errorCommonly used methods of locating and the locating elements （the surfaces of the workpiece) A locating by flat/plane/surface（平面定位）Fixed/adjustable/self-adapted/auxiliary suppor

40、t(固定/可調(diào)/自位/輔助支承)Section 3 Workpiece-clamping in the fixtureRequirements of the clamping forcesDetermination of the clamping forcesCommonly used clamping mechanismsRequirements of the clamping forcesI sustain, during the whole period of clamping, the proper position of the workpiece when it locates I

41、I be reliable and proper. The clamping mechanisms are, usually, supposed to have the function of self-locking, guaranteeing the clamping device being free from relief and vibration. On the other hand, preventing ought to promise from being unwanted deformation and the damage of the surfaces.III It i

42、s taken for grant that the clamping device is convenient, not energy-consuming, and safe, to operate.IV be consistent ,for the complexity and level of automation of the clamping device, with the batch production and the pattern of productionA Direction The following rules should be ensured: favorabl

43、e for the workpiece locatingParallel to the direction of the most rigid of the workPreferable to parallel to the direction of the cutting forces, or the gravity of the work to reduce the clamping forceB Exerting pointunder the given force, to select the point at which the clamping force actuates and

44、 the number of the exerting pointsI the exerting point coincides with the supports of the fixture or is on the supporting area backed by the supports.II the exerting point ought to be so set that the touched area has great rigidity of the work, in order to reduce the deformation of the work possible

45、 to occur.III It is preferable to exert the clamping force at the as near place of the being cut surface as possible to eliminate the turn-over moment by the cutting forces.C Magnitude of the clamping forcesSection 4 types of machine tool mixturesDrill jigs; Borer jigs; Milling machine fixtures; Lat

46、he fixtures; Group fixtures; Composite fixtures;Transferring fixturesCHAPTER THREE MECHANICAL PROCESS ACCURACY1 Concept of the machining accuracy and the influencing factors2 Geometric accuracy influencing the machining accuracy3 Deformation of the processing system from external forces 4 Deformatio

47、n of the processing system caused by heat5 Statistics and analysis, and ways of guaranteeing and enhancing the machining accuracySection 1 Brief introduction to Machining AccuracyThe quality of a component by machining contains two-fold, one is Mechanical Process Accuracy ,and another is the Integri

48、ty of Machined Surfaces .Here we discuss the first aspect of the quality of the component .Mechanical process accuracy is the degree of the real geometry (including the size, form, and relative position between surfaces) of a workpiece imparted by machining that approaches the perfect geometry. Infl

49、uencing factors of machining accuracy1) Installation of the workpiece(工件的裝夾)installing error of the workpiece（工件裝夾誤差）2) Adjustment of the processing system（機床、刀具和夾具的調(diào)整）geometric error of the processing system（工藝系統(tǒng)幾何誤差）3) Machining operation （加工過程）dynamic error(動誤差)Sensible direction of the error: on

50、 the workpiece the initial errors vary both in magnitude and in direction, when the direction of initial error is parallel to that of the sequential size, such error has the greatest influence on the machining accuracy. So we call this direction Sensible direction of the error. Section 2 The influen

51、ce of geometric accuracy of the processing system on the machining accuracyA error of principle in machining(加工原理誤差)B error of adjustment (調(diào)整誤差)C error of machine tools(機床誤差)Guiding error of the guide-way, For a linear guide-way, the guiding accuracy includeslinearity on the horizontal plane, y, lin

52、earity on the vertical plane, z, parallelism between the two guide-ways ( warp，扭曲), and the parallelism between the guide-way and the axis of the spindle Rotating error of the spindle Notion：rotating accuracy of the spindle is one of the main aspects of accuracy. Rotating accuracy of the spindle inf

53、luences mainly the accuracy of geometric form, position, and roughness, of the machined surfaces because of its function of installing and clamping the work or tool, and providing the primary power and machining movement. Rotating error of the spindle is the real floatation/drift of the rotating axi

54、s from the perfect rotating axis of the spindle, including radial-round flounce, facial-round flounce, and inclined-angular swing.and transmitting error of the transmission linkageD error of the fixture in its own production and wear（夾具制造誤差與磨損）E error of the tool in its own production and wear（刀具制造誤

55、差與磨損）Section 3 Deformation of the processing system from external forcesBasic concept: in machining, any element or all the elements of the processing system may be subjected to cutting force, clamping force, and weight, leading to deform, and further cause machining errorsThe ability to resist the

56、deformation is often expressed in terms of rigidity k (剛度) of the system，which means the ratio of the normal component of the cutting force to the displacement of the work in the direction of the normal component of the cutting forceSection 4 Deformation of the processing system caused by heata) Not

57、ion of the deformation from heat, and the heat balance and temperature distributionb) Influence of the deformation of the work from heat on machining accuracyc) Influence of the deformation of the tool from heat on machining accuracyd) Influence of the deformation of the machine tool from heat on ma

58、chining accuracye) Ways of reducing the influence of the deformation from heat on the machining accuracyOrigin of the heat:Internal heat source :mainly the cutting force and friction forces with the conductivityExternal heat source: mainly the environmental temperature with circulation, as well as h

59、eat-radiating sourcesThe cutting force is the main and important source of heatThe heat balance and the temperature fieldQgeneration+Qtakein=Qgoingout =(x, y, z, t) (x, y, z ) deformation(x, y, z )Ways of reducing the influence of the deformation from heat on the machining accuracy1) Reducing the he

60、at from the heat source and keeping free from the heat source2)Evening the temperature field/distribution3)Adopting the proper structure and assembling datums of the machine tool4)Speeding up the procedure of heat balance5)Controlling the surrounding temperatureSection 5 Statistics and analysis, and