【文章內(nèi)容簡(jiǎn)介】 產(chǎn)工藝 ,采用傳統(tǒng)加工過(guò)程不可行 ,滿意或經(jīng)濟(jì)因特殊原因如下所示 : 1. Very bard fragile materials difficult to clamp for traditional machining。 1。非常脆 弱的材料很難夾巴德傳統(tǒng)加工 。 2. When the workpiece is too flexible or slender, 2。當(dāng)工件太靈活或苗條 , 3. When the shape of the part is too plex。 3。當(dāng)形狀的部分是過(guò)于復(fù)雜 。 4. Parts without producing buns or inducing residual stresses. 4。部分沒(méi)有生產(chǎn)面包或誘導(dǎo)殘余應(yīng)力。 Traditional machining can be defined as a process using mechanical (motion) energy. 傳統(tǒng)加工可以被定義為一個(gè)流程使用機(jī)械 (運(yùn)動(dòng) )能量。 Nontraditional machining utilizes other forms of energy。 the three main forms of energy 非傳統(tǒng)加工利用其他形式的能源 。三種主要形式的能量 used in nontraditional machining processes are as follows: 用于非傳統(tǒng)加工過(guò)程如下 : 1. Thermal energy。 1。熱能 。2. Chemical energy, 2?；瘜W(xué)能源 ,3. Electrical energy. 3。電能。 Several types of nontraditional machining processes have been developed to meet extra required machining conditions. When these processes are employed properly, they offer many advantages over traditional machining processes. The mon nontraditional machining processes are described in the following section. 幾種類型的非傳統(tǒng)加工過(guò)程已經(jīng)被開(kāi)發(fā)出來(lái) ,以滿足額外的要求加工條件。當(dāng)這些流程是正確使用 ,他們提供了許多優(yōu)點(diǎn)比傳統(tǒng)的加工過(guò)程。常見(jiàn)的非傳統(tǒng)加工過(guò)程是下一節(jié)描述。 Electrical Discharge Machining (EDM) 電火花加工 (EDM) Electrical discharge machining (EDM) sometimes is colloquially referred to as spark machining, spark eroding, burning, die sinking or wire erosion. It is one of the most widely used nontraditional machining processes. The main attraction of EDM over traditional machining processes such as metal cutting using different tools and grinding is that this technique utilizes thermoelectric process to erode undesired materials from the workpiece by a series of rapidly recurring discrete electrical sparks between workpiece and electrode. [2] 電火花加工 (EDM)有時(shí)是通俗地稱為電火花加工、電火花侵蝕 ,燃燒 ,開(kāi)?；蜾摻z侵蝕。這是一個(gè)最廣泛使用的非傳統(tǒng)加工過(guò)程。主要的吸引力比傳統(tǒng)的電火花加工過(guò)程 ,如金屬切削使用不同的工具和磨削是這種技術(shù)利用熱電過(guò)程侵蝕無(wú)用的材料工件的一系列迅速反復(fù)出現(xiàn)的離散 電火花工件和電極之間。 [2] The traditional machining processes rely on harder tool or abrasive material to remove the softer material whereas nontraditional machining processes such as EDM uses electrical spark or thermal energy to erode unwanted material in order to create desired shapes. So, the hardness of the material is no longer a dominating factor for EDM process. 傳統(tǒng)的加工流程依賴?yán)щy工具或研磨材料去除軟 材料而非傳統(tǒng)加工如 EDM使用電火花或熱能侵蝕多余的材料以創(chuàng)建所需的形狀。所以 ,硬度的材料不再是一個(gè)主要因素電火花放電加工。 EDM removes material by discharging an electrical current, normally stored in a capacitor bank, across a small gap between the tool (cathode) and the workpiece (anode) typically in the order of 50 volts/l0 amps. As shown in Fig6. 1, at the beginning of EDM operation, a high voltage is applied across the narrow gap between the electrode and the workpiece. This high voltage induces an electric field in the insulating dielectric that is present in narrow gap between electrode and workpiece. This cause conducting particles suspended in the dielectric to concentrate at the points of strongest electrical field. When the potential difference between the electrode and the workpiece is sufficiently high ,the dielectric breaks down and a transient spark discharges through the dielectric fluid, removing small amount of material from the workpiece surface. The volume of the material removed per spark discharge is typically in the range of 105 to 106 mm3. The gap is only a few thousandths of an inch, which is maintained at a constant value by the servomechanism that actuates and controls the tool feed. 除材料的電火花加工放電電流 ,通常存儲(chǔ)在電容器銀行 ,在一個(gè)小差距工具 (陰極 )和工件 (陽(yáng)極 )通常在訂單 50 伏特 / 10 安培。圖 6 所示。 1,開(kāi)始時(shí) ,一個(gè)高壓電火花加工操作是應(yīng)用在狹窄的電極之間的差距和工件。這個(gè)高電壓產(chǎn)生電場(chǎng)在絕緣介質(zhì)中存在的差距和工件之間的狹窄電極。這導(dǎo)致導(dǎo)電粒子懸浮在介質(zhì)集中點(diǎn)的最強(qiáng)的電場(chǎng)。當(dāng)潛在的區(qū)別和工件的電極是足夠高 ,電介質(zhì)分解和瞬時(shí)放電通過(guò)電介質(zhì) ,消除少量的材料從工件表面。材料去除的體積每火花放電通常在 10 5 到 10 6 的范圍 mm3。這個(gè)差距只有幾英寸的秒這個(gè)級(jí)別 ,這是維持在一個(gè)恒定值由伺服機(jī)構(gòu) ,促動(dòng)和控制工具進(jìn)給。 Chapter 7 Introduction 引入 Quality and accuracy are major considerations in making machine parts or structures. 質(zhì)量和準(zhǔn)確性是主要的考慮因素在制造機(jī)零件或結(jié)構(gòu)。 Interchangeable parts require a high degree of accuracy to fit together. With increasing accuracy or less variation in the dimension, the labor and machinery required to manufacture a part is more cost intensive. [l] Any manufacturer should have a thorough knowledge of the tolerances to increase the quality and reliability of 39。a manufactured part with the least expense. 具有互換性的零件需要一個(gè)高精確度來(lái)組裝在一起。隨著準(zhǔn)確性或更少的變異在尺寸、勞動(dòng)和機(jī)械需要制造一個(gè)部分是更多的成本密集型。 []是任何制造商應(yīng)該有一個(gè)全面的知識(shí)的公差 ,以便提高質(zhì)量和可靠性的一個(gè)制造最少的部分費(fèi)用。 An engineering drawing must be properly dimensioned in order to convey the designer39。s intent to the end user. Dimensions of parts given on blueprints and manufactured to those dimensions should be exactly alike and fit properly. Unfortunately, it is impossible to make things to an exact or dimension. Most dimensions have a varying degree of accuracy and a means of specifying acceptable limitations in dimensional variance so that a manufactured part will be accepted and still function. It is necessary that the dimensions, shapes and mutual position of surfaces of individual parts are kept within a certain accuracy to achieve their correct and reliable functioning. Routine production processes do not allow maintenance (or measurement) of the given geometrical properties with absolute accuracy. [2] Actual surfaces of the produced parts therefore differ from ideal surfaces prescribed in drawings. Deviations of actual surfaces are divided into four groups to enable assessment, prescription and checking of the permitted inaccuracy during production: 一個(gè)工程圖紙必須得到適當(dāng)?shù)某叽?,以傳達(dá)設(shè)計(jì)者的意圖給最終用戶。維度上給出的部分設(shè)計(jì)圖和制造這些維度應(yīng)該完全一樣 ,恰到好處。不幸的是 ,它是不可能讓事情一個(gè)確切的或維度。大多數(shù)維度有不同程度的準(zhǔn)確性和一種方式來(lái)指定可接受的限制在維方差這樣一個(gè)人造的部分會(huì)被接受 ,還是函數(shù)。這是必要的 ,尺寸、形狀和表面的相互位置的各個(gè)部分都保持在一定的精度 ,達(dá)到他們的正確和可靠的功能。日常生產(chǎn)過(guò)程不允許維護(hù) (或測(cè)量 )給定的幾何屬性以絕對(duì)的精度。 [2]實(shí)際表面產(chǎn)生部分因此不同于理想的表面在圖紙規(guī)定。偏離實(shí)際的表面分為四組 ,使評(píng)估、處 方和檢查錯(cuò)誤的允許生產(chǎn)過(guò)程中 : 1. Dimensional deviations。 1。尺寸偏差 。 2. Shape deviations。 2。形狀的偏差 。 3. Position devi