1、機(jī)械工程英語機(jī)械工程英語Mechanical Engineering EnglishDefinition of a Drill JigContentsTypical Jigs and Fixtures1234New Words and Terminologies Jig : 鉆模 Fixture：夾具 Workpiece：工件 Cutting tool：刀具，切削工具，切削刀具 Clamp：vt, 夾住，加緊；n, 夾具 Casting :n,鑄造，鑄件 Forging: n, 鍛造，鍛件 Rib：n, 加強(qiáng)肋 Core: n,型芯 Drill: n, 鉆頭，鉆機(jī) Reamer: n, 鉸刀N

2、ew Words and Terminologies Cutter : n, 銑刀 Bolt: n, 螺栓 Nut ：n, 螺母 Clearance: n, 間隙 Observance :n, 遵守 Encroach :侵犯，侵占 Perpendicular:垂直的 Tap: 攻螺紋 Bushing : n, 套管，襯管 Hardened-steel：淬火鋼 Flange : n,法蘭，凸緣 Milling: n, 銑削 planing: n, 刨 Shaping: n,成形 Turning: n,車削，車削加工 Tenon: n,突隼New Words and TerminologiesIn

3、troduction It has already been stated that the workpiece must be located relative to the cutting tool, and be secured in that position. After the workpiece has been marked out, it is still necessary to position it with re s p e c t to t h e m a c h i n e movements, and to clamp it in that position b

4、efore machining is started.已經(jīng)說明了工件必須相對于切削刀具定位并確保到位。工件劃線后，仍有必要將其相對于切削運動定位，并在機(jī)加工開始前把它裝夾到位。工件工件劃線劃線機(jī)械工程英語機(jī)械工程英語When several identical workpieces are to be produced the need to mark out each part is eliminated by the use of jigs and fixtures, but if a casting or forging is involved, a trial workpiece is

5、 marked out, to ensure that the workpiece can be produced from it, and to ensure that ribs, cores, etc. have not become misplaced.當(dāng)要加工若干同樣的工件時，使用鉆模和夾具可以不必在每個工件上劃線；但對鑄件或鍛件而言，還需取一試驗工件劃線以保證照此加工不會將加強(qiáng)肋、型芯等放錯位置。鉆模鉆模夾具夾具鑄件鑄件鍛件鍛件加強(qiáng)肋加強(qiáng)肋型芯型芯機(jī)械工程英語機(jī)械工程英語 Jigs and fixtures are alike in that they both incorporat

6、e devices to ensure that the workpiece is correctly located and clamped, but they differ in that jigs incorporate means of tool guiding during the actual cutting operation, and fixtures do not. In practice, the only cutting tools that can be guided while actually cutting are drills, reamers, and sim

7、ilar cutters; and so jigs are associated with drilling operations, and fixtures with all other operations. Fixtures may incorporate means of setting the cutting tools relative to the location system.鉆模和夾具的相似點是它們都把保證工件正確定位和夾緊的裝置相結(jié)合，它們的不同在于鉆模在實際切削作業(yè)中還能與刀具導(dǎo)向方法相結(jié)合，它們的不同在于鉆模在實際切削作業(yè)中還能與刀具導(dǎo)向方法相結(jié)合，而夾具則不能。實際

8、上，在真實切削中能被導(dǎo)向的切削刀具只有鉆頭、鉸刀和類似的刀具；因此鉆模用于鉆削作業(yè)，而夾具用于其余作業(yè)。夾具可以與切削刀具相對定位系統(tǒng)裝夾的方法結(jié)合在一起。夾緊夾緊切削操作切削操作鉆頭鉆頭鉸刀鉸刀刀具刀具機(jī)械工程英語機(jī)械工程英語The advantages of jigs and fixtures can be summarized as follows:1)Marking out and other measuring and setting out methods are eliminated; 2)Unskilled workers may proceed confidently and

9、 quickly in knowledge that the workpiece can be positioned correctly, and the tools guided or set;鉆模和夾具的優(yōu)點可歸納如下： 1)可以省去劃線和其它測量及放樣程序； 2)在知道工件能正確定位、刀具能恰當(dāng)導(dǎo)向或裝夾的情況下，不熟練的工人也能自信而快速地操作；布置，安裝布置，安裝機(jī)械工程英語機(jī)械工程英語 3)the assembly of parts is facilitated, since all components will be identical within small limits,

10、 and “trying” and filing of work is eliminated; 4)The parts will be interchangeable, and if the product sold over a wide area, the problem of spare parts will be simplified.3)由于所有零件在較小極限范圍內(nèi)是相同的，可以省掉工件的試裝和銼削銼削，所以零件裝配很方便； 4)零件具有互換性，這樣如果產(chǎn)品在較大范圍內(nèi)銷售的話，備件問題將簡單化。銼削銼削機(jī)械工程英語機(jī)械工程英語Bolt holes often have 1.5mm

11、or even 3.0mm clearance for the bolt, and the reader may doubt the necessity of making precision jigs for such work. It must be remembered that the jigs, once made, will be used on many components, and the extra cost of an accurately made jig is spread over a large output. Furthermore, it is surpris

12、ing how small errors accumulate in a mechanism during its assembly. When a clearance is specified, it is better to ensure its observance, rather than to allow careless marking out and machining to encroach upon it螺栓孔常給螺栓留出1.5毫米或甚至3.0毫米的間隙，讀者可能會懷疑為這樣的工作制造精密鉆模的必要性。但要記住，這種鉆模一旦造好，可用于許多零部件，精確制造鉆模的額外成本可分?jǐn)?/p>

13、在大量產(chǎn)品上。此外，這樣做在裝配機(jī)械裝置時其累積誤差之小也是令人驚訝的。在確定一個間隙時，最好能保證它的習(xí)慣要求，而不是隨便劃線和機(jī)加工使其超出正常的界限。螺栓螺栓間隙間隙遵守遵守侵犯，侵占侵犯，侵占機(jī)械工程英語機(jī)械工程英語 1) The location of workpiece. Fig.13.1 represents a body that is completely free in space. In this condition it has six degrees of freedom. Consider these freedoms with respect to the thr

14、ee mutually perpendicular axes XX, YY, and ZZ. The body can move along any of these axes; it therefore has three freedoms of translation. It can also rotate about any of the three axes; it therefore has three freedoms of rotation. The total number of freedoms is six. 自由度自由度垂直的垂直的axis機(jī)械工程英語機(jī)械工程英語When

15、 work is located, as many of these freedoms as possible must be eliminated, to ensure that the operation is performed with the required accuracy. Accuracy is ensured by machining suitable location features as early as possible, and using them for all location, unless other considerations mean that o

16、ther location features must be used. If it is necessary, the new location features must be machined as a result of location from the former location features.機(jī)械工程英語機(jī)械工程英語1) 工件的定位：工件的定位：圖13.1表示一個在空間完全自由的物體，在這種情況下它具有六個自由度。相對于三根互相垂直的坐標(biāo)軸XX、YY和ZZ來考慮這些自由度。此物體能沿三根坐標(biāo)軸的任意一根移動；這樣就具有三個平移自由度。它也能圍繞三根坐標(biāo)軸的任意一根回轉(zhuǎn)；這

17、樣它又具有三個旋轉(zhuǎn)自由度?？偟淖杂啥葦?shù)目是六個。當(dāng)工件被定位時，必須盡可能多地消除這些自由度，以保證作業(yè)按要求精度進(jìn)行。除非有必要采用另外定位要素的其它考慮，精度可通過盡可能早地加工合適的定位要素并采用它們進(jìn)行所有定位來保證。如果必要的話，新的定位要素必須作為先前的定位要素的定位結(jié)果來加工。機(jī)械工程英語機(jī)械工程英語2) The clamping of the workpiece. The clamping system must be such that the workpiece is held against the cutting forces, and the clamping for

18、ces must not be so great as to cause the workpiece to become distorted or damaged. The workpiece must be supported beneath the point of clamping, to ensure that the forces are taken by the main frame of the jig or fixture, and on to the machine table and bed. When jigs and fixtures are designed, the

19、 clamping system is designed to ensure that the correct clamping force is applied, and that the clamps can be operated quickly but with safety.切削力切削力裝夾力裝夾力機(jī)械工程英語機(jī)械工程英語2) 工件的裝夾：工件的裝夾：裝夾系統(tǒng)必須使工件對著切削力夾持，而且裝夾力又不能大得引起工件變形或損壞。工件必須在裝夾點下被支撐，以保證這些力由鉆模或夾具的主框架來承受并傳遞給機(jī)床工作臺和床身。在設(shè)計鉆模和夾具時，要同時設(shè)計裝夾系統(tǒng)來保證提供恰當(dāng)?shù)难b夾力，并使裝夾操

20、作快速而安全。Definition of a Drill JigA drill jig is a device for ensuring that a hole to be drilled, tapped, or reamed in a workpiece will be machined in the proper place. Basically it consists of a clamping device to hold the part in position under hardened-steel bushings through which the drill passes

21、during the drilling operation. The drill is guided by the bushings. If the workpiece is of simple construction, the jig may be clamped on the workpiece. In most cases, however, the workpiece is held by the jig, and the jig is arranged so that the workpiece can be quickly inserted and as quickly remo

22、ved after the machining operation is performed.鉆鉆攻螺紋攻螺紋鉸鉸淬火鋼淬火鋼套管，襯管套管，襯管Definition of a Drill Jig鉆模是一種確保在工件正確位置進(jìn)行鉆孔、攻絲或鉸孔加工的裝置。它基本上由在淬硬鋼襯套下將零件夾持到位的夾持裝置組成，鉆孔作業(yè)中鉆頭穿過這些襯套，通過它們來導(dǎo)向。如果工件結(jié)構(gòu)比較簡單，鉆?？蓨A持在工件上。然而大多數(shù)情況下，工件由鉆模來夾持，并且把鉆模設(shè)計成能將工件迅速裝入而在加工后同樣能很快取出。機(jī)械工程英語機(jī)械工程英語 Jigs make it possible to drill, ream, and

23、tap holes at much greater speeds and with greater accuracy than when the holes are produced by conventional hand methods. Another advantage is that skilled workers are not required when jigs are used. Responsibility for the accuracy of hole location is taken from the operator and given to the jig.相對

24、于用常規(guī)的手工方法加工孔，鉆模使得鉆孔、鉸孔和攻絲速度快很多而且精度更高成為可能。另一個優(yōu)點是采用鉆模時不需要熟練工人。保證孔定位精度的責(zé)任從操作者身上轉(zhuǎn)移到了鉆模上。機(jī)械工程英語機(jī)械工程英語 The term jig should be used only for devices employed while drilling, reaming, or tapping holes. It is not fastened to the machine on which it is used and may be moved around on the table of the drilling

25、 machine to bring each bushing directly under the drill. Jigs physically limit and control the path of the cutting tool.鉆模這個術(shù)語只用在服務(wù)于鉆孔、鉸孔或攻絲的裝置上。它不固定在使用它的鉆床上，它能在鉆床工作臺上到處移動以使每個襯套都直接位于鉆頭下。鉆模有形地限制和控制鉆削刀具的路徑。機(jī)械工程英語機(jī)械工程英語 If the operation includes machining operations like milling, planing, shaping, turn

26、ing, etc., the term fixture should be used. A fixture holds the work during machining operations but does not contain special arrangements for guiding the cutting tool ,as drill jigs do.如果作業(yè)還包括其它象銑削、刨削、成型、車削等機(jī)加工，則應(yīng)采用夾具這一術(shù)語。夾具在機(jī)加工作業(yè)時夾持工件，但它不象鉆模那樣包含引導(dǎo)切削刀具的特殊布置。Typical Jigs and FixturesTypical drill ji

27、g. Figure 13.2 illustrates a drilling jig for drilling four holes in the flange of a workpiece that has been completed except for the four holes. The workpiece has an accurately machined bore, and is located from the bore and the end face, from a cylindrical post. There is no need to control the rot

28、ational position about the axis of the bore, because up to the time when the holes are drilled, it is symmetrical about that axis. The four bushes used to control the drill are held in the drill plate, which, with the hand nut, is used to clamp the workpiece against the base of the fixture.Typical J

29、igs and Fixtures典型的鉆模：典型的鉆模：圖13.2所示為一個能在某工件的法蘭上鉆四個孔的鉆模，該工件除了這四個孔外已全部完成。此工件有一精確機(jī)加工的大孔，因此通過一圓柱體采用該孔和工件端面定位。由于直至鉆這些小孔時，工件都對稱于大孔軸線，所以沒必要控制圍繞大孔軸線回轉(zhuǎn)的位置。四個控制鉆頭的襯套裝在鉆板里，連同手?jǐn)Q螺母一起用于靠著夾具基座夾持工件。Typical Jigs and FixturesTypical milling fixture. Figure 13.3 illustrates a simple milling fixture for milling the slo

30、t in the otherwise completed workpiece shown. The workpiece is located from two of the four holes in its base, and from the underside of the base. The workpiece is clamped in position, and cutter is located against the setting block, which provides setting or cutter position and depth of cut. The fixture must be po