棒料自動(dòng)切割裝置設(shè)計(jì)
棒料自動(dòng)切割裝置設(shè)計(jì),棒料自動(dòng)切割裝置設(shè)計(jì),自動(dòng),切割,裝置,設(shè)計(jì)
第五章翻譯
（電火花線切割的介紹）
電火花線切割加工在對(duì)一些難切削的材料、特殊及復(fù)雜形狀的零件的加工上較傳統(tǒng)的切削加工方法具有明顯的優(yōu)勢(shì)，因此被廣泛應(yīng)用于模具、工具、航空航天等制造加工領(lǐng)域。
??? 根據(jù)電極絲運(yùn)動(dòng)的方式將電火花線切割機(jī)床分為快走絲電火花線切割機(jī)床和慢走絲電火花線切割機(jī)床，二者具有不同的特點(diǎn)和應(yīng)用場(chǎng)合?？熳呓z電火花線切割機(jī)床因其操作簡(jiǎn)單、成本低等優(yōu)點(diǎn)而被普遍采用。在線切割加工過(guò)程中，影響加工質(zhì)量和效率的因素較多，本文結(jié)合相關(guān)資料，對(duì)數(shù)控快走絲電火花線切割加工的工藝方法進(jìn)行研究。
??? 一．加工原理
??? 1．電極絲與工件之間脈沖式放電加工；
??? 2．電極絲沿其軸向作走絲運(yùn)動(dòng)；
??? 3．工件相對(duì)于電極絲在X，Y平面內(nèi)作數(shù)控運(yùn)動(dòng)。
??? 二．?dāng)?shù)控電火花線切割加工的特點(diǎn)
??? 1．無(wú)需制造成形電極，工件材料的預(yù)留量少；
??? 2．能夠方便地加工復(fù)雜形狀的型孔，微孔，窄縫等；
??? 3．直接采用精加工和半精加工規(guī)準(zhǔn)一次加工成形，一般不需要中途轉(zhuǎn)換規(guī)準(zhǔn)；
??? 4．只對(duì)工件材料進(jìn)行圖形輪廓加工，圖形內(nèi)外的余料還可利用；
??? 5．自動(dòng)化程度高，操作方便，加工周期短，成本低。
??? 三．?dāng)?shù)控電火花線切割加工的應(yīng)用
??? 數(shù)控電火花線切割加工為新產(chǎn)品試制，精密零件加工及模具制造開辟了一條新的工藝途徑，主要應(yīng)用于以下幾個(gè)方面：
??? 1．適用于各種形狀的冷沖模具。
??? 2．可以加工微細(xì)異形孔、窄縫和復(fù)雜形狀的工件。
??? 3．加工樣板和成型刀具。
??? 4．加工粉末冶金模、鑲拼型腔模、拉絲模、波紋板成型模。
??? 5．加工硬質(zhì)材料、切割薄片，切割貴重金屬材料。
??? 6．加工凸輪，特殊的齒輪。
??? 7．適合于小批量、多品種零件的加工，減少模具制作費(fèi)用，縮短生產(chǎn)周期。
??? 四．?dāng)?shù)控電火花線切割的加工工藝
??? 1．工件材料的選擇
??? 為了加工出尺寸精度高、表面質(zhì)量好的線切割產(chǎn)品，必須對(duì)所用工件材料進(jìn)行細(xì)致考慮：
??? (1) 由于工件材料不同，熔點(diǎn)、氣化點(diǎn)、導(dǎo)熱系數(shù)等都不一樣，因而即使按同樣方式加工，所獲得的工件表面質(zhì)量也不相同，因此必須根據(jù)實(shí)際需要的表面質(zhì)量對(duì)工件材料作相應(yīng)的選擇。例如要達(dá)到高精度，就必須選擇硬質(zhì)合金類材料，而不應(yīng)該選不銹鋼或未淬火的高碳鋼等，否則很難達(dá)到所需要求。
?? (2) 由于工件材料內(nèi)部殘余應(yīng)力對(duì)加工的影響較大，在對(duì)熱處理后的材料進(jìn)行加工時(shí)，由于大面積去除金屬和切斷加工會(huì)使材料內(nèi)部殘余應(yīng)力的相對(duì)平衡受到破壞，從而可能影響零件的加工精度和表面質(zhì)量。為了避免這些情況，應(yīng)選擇鍛造性好、淬透性好、熱處理變形小的材料。
??? 2．切割路線的選擇（多次切割）
??? 為了獲得較高的加工精度，可以考慮在快走絲線切割機(jī)床采用多次切割工藝。
采用多次切割工藝時(shí)，第一次切割主要進(jìn)行高速穩(wěn)定切割，因此可選用高峰值電流；第二次切割的主要任務(wù)是修光。應(yīng)選擇較小的脈沖電流和脈沖寬度。
??? 3．穿絲孔和電極絲切入位置的選擇
??? 對(duì)于不同的工件，加工穿絲孔的位置不同。在切割中、小孔形凹形類工件時(shí)，穿絲孔應(yīng)位于凹形的中心位置，既便于穿絲孔加工位置準(zhǔn)確，又便于控制坐標(biāo)軌跡的計(jì)算；在切割凸形或大孔形凹形類工件時(shí)，穿絲孔應(yīng)設(shè)置在加工起點(diǎn)附近，以縮短無(wú)用切割行程，同時(shí)應(yīng)便于簡(jiǎn)化有關(guān)軌跡控制的計(jì)算。穿孔絲也可選在距離型孔邊緣2-5mm處,如圖所示。加工凸模時(shí)，為減小變形，電極絲切割時(shí)的運(yùn)動(dòng)軌跡與運(yùn)動(dòng)邊緣的距離應(yīng)大于5mm.
??? 4．電參數(shù)的選擇
??? 對(duì)加工質(zhì)量具有明顯影響的電參數(shù)主要包括脈沖電流、脈沖寬度、脈沖間隔、運(yùn)絲速度等，通常需要在保證表面質(zhì)量、尺寸精度的前提下，盡量提高加工效率。
??? 脈沖電源是影響加工表面質(zhì)量的重要因素。減小單個(gè)脈沖能量可以改善表面粗糙度。決定單個(gè)脈沖能量的因素主要是脈沖寬度和脈沖電流。因此采用小的脈沖寬度和脈沖電流可獲得良好的表面粗糙度。但是單個(gè)脈沖能量越小， 切割速度越慢， 如果脈沖電流太小，將不能產(chǎn)生放電火化， 不能正常切割。一般來(lái)講，精加工時(shí)，脈沖寬度可在20μs內(nèi)選擇；中加工時(shí)，可在20μs～60μs內(nèi)選擇。
??? 脈沖間隔對(duì)切割速度影響較大，而對(duì)表面粗糙度影響較小。脈沖間隔越小，單位時(shí)間放電加工的次數(shù)越多，因而切割速度也越高。實(shí)際上，脈沖間隔不能太小，否則放電產(chǎn)物來(lái)不及被沖刷掉，放電間隙不能充分消電離，加工不穩(wěn)定，容易燒傷工件或斷絲。對(duì)于厚度較大的工件，應(yīng)適當(dāng)加大脈沖間隔，以充分消除放電產(chǎn)物，形成穩(wěn)定切割。一般脈沖間隔在10μs～250μs范圍內(nèi)基本上能適應(yīng)各種加工條件，進(jìn)行穩(wěn)定加工。
??? 走絲速度對(duì)加工速度具有一定影響，隨著走絲速度的提高，加工速度將明顯增大。但是，高速度會(huì)引起電極絲較大的振動(dòng)而使工件表面的直線度和粗糙度惡化。因此，應(yīng)在保證加工質(zhì)量的前提下，選擇一個(gè)具有適當(dāng)加工速度的合理走絲速度。
??? 5．其它非電參數(shù)的選擇
?? （1）電極絲及其走絲速度的選擇
??? 一般采用￠0.06-0.20mm的鉬絲。提高走絲速度有利于電極絲把工作液帶入較大厚度的工件放電間隙中，有利于電蝕產(chǎn)物排放和放電加工的穩(wěn)定。
?? （2）工作液的選擇及使用
??? 煤油介電強(qiáng)度高，間隙消耗放電能量多，分配到兩極的能量少，排屑困難，故切割速度低。但煤油受冷熱變化影響不明顯，且潤(rùn)滑性能好，因此不容易斷絲。皂化液洗滌性能好，有利于排屑，切割速度較高。
??? 乳化型工作液的節(jié)電強(qiáng)度比水高，比煤油低，冷卻能力比水弱，比煤油好，洗滌性比水和煤油都好，較非乳化型工作液的切割速度高，是普遍使用的工作液。
??? 純凈的工作液最初使用時(shí)并不能獲得最好加工效果，而在使用1～2個(gè)工作日后，金屬屑進(jìn)入工作液中形成一定臟度的混合液，這種混合液在切割中具有良好的效果。因此，定期更換工作液時(shí)往往不需要將工作液箱清洗非常干凈，以獲得具有一定臟度的混合液。
???? 五．常見問題的處理
??? 1．五種放電狀態(tài)
?? （1）開路（空載脈沖）
??? 放電間隙沒有擊穿，間隙上有大于50V的電壓，但間隙內(nèi)沒有電流流過(guò)，為空載狀態(tài)（td=ti）。
?? （2）火花放電（工作脈沖，或稱有效脈沖）
??? 間隙內(nèi)絕緣性能良好，工作液介質(zhì)擊穿后能有效地拋出、蝕除金屬。波形特點(diǎn)是：電壓上有td，te和Ie波形上有高頻振蕩的小鋸齒波形。
?? （3）短路（短路脈沖）
??? 放電間隙直接短路相接，這是由于伺服進(jìn)給系統(tǒng)瞬時(shí)進(jìn)給過(guò)多或放電間隙中有電蝕產(chǎn)物搭接所致。間隙短路時(shí)電流較大，但間隙兩端的電壓很小，沒有蝕除加工作用。
?? （4）電弧放電（穩(wěn)定電弧放電）
??? 由于排屑不良，放電點(diǎn)集中在某一局部而不分散，局部熱量積累，溫度升高，惡性循環(huán)，此時(shí)火花放電就成為電弧放電，由于放電點(diǎn)固定在某一點(diǎn)或某局部，因此稱為穩(wěn)定電弧，常使電極表面結(jié)炭、燒傷。波形特點(diǎn)是td和高頻振蕩的小鋸齒波基本消失。
?? （5）過(guò)渡電弧放電（不穩(wěn)定電弧放電，或稱不穩(wěn)定火花放電）
??? 過(guò)渡電弧放電是正?；鸹ǚ烹娕c穩(wěn)定電弧放電的過(guò)渡狀態(tài)，是穩(wěn)定電弧放電的前兆。波形特點(diǎn)是擊穿延時(shí)td很小或接近于零，僅成為一尖刺，電壓電流波上的高頻分量變低成為稀疏和鋸齒形。早期檢測(cè)出過(guò)渡電弧放電，對(duì)防止電弧燒傷有很大意義。
??? 2．精度、表面質(zhì)量分析及解決辦法
??? 由于高速絲線切割機(jī)是采取線電極高速往復(fù)供絲的方式，線電極的損耗均勻地分布在近300米電極絲上，雖然電極絲的損耗極小，但電火花線切割機(jī)工作時(shí)影響其加工工件表面質(zhì)量的因素很多，更需要對(duì)其有關(guān)加工工藝參數(shù)進(jìn)行合理選配，才能保證所加工工件表面質(zhì)量。
??? 對(duì)線切割加工質(zhì)量有直接影響的因素主要涉及人員、設(shè)備、材料等方面。為了改善加工工件表面質(zhì)量，可以從影響最大的人為因素、機(jī)床因素和材料因素等三方面來(lái)考慮對(duì)加工質(zhì)量的控制方式和改進(jìn)方法。具體方法如下：
??（1）合理安排切割路線。
?? （2） 正確選擇切割參數(shù)。
?? （3）采用近距離加工。
??（4）注意加工工件的固定。
?? （5）在加工前，必須檢查電極絲，電極絲的張力對(duì)加工工件的表面質(zhì)量也有很大的影響，加工表面質(zhì)量要求高的工件，應(yīng)在不斷絲的前提下盡可能提高電極絲的張力。
?? （6）高速走絲線切割機(jī)一般采用乳化油與水配制而成的工作液。
?? （7）必須檢查導(dǎo)電塊的磨損情況。
?? （8）檢查導(dǎo)輪的轉(zhuǎn)動(dòng)情況，若轉(zhuǎn)動(dòng)不好則應(yīng)更換，還必須仔細(xì)檢查上、下噴嘴的損傷和臟污程度，用清洗液清除臟物，有損傷時(shí)需及時(shí)更換。還應(yīng)經(jīng)常檢查貯絲筒內(nèi)絲的情況，絲損耗過(guò)大就會(huì)影響加工精度及表面質(zhì)量。
?? （9）保持穩(wěn)定的電源電壓。
?? （10）根據(jù)實(shí)際需要的表面質(zhì)量對(duì)工件材料作相應(yīng)的選擇。
?? （11）加工過(guò)程中應(yīng)將各項(xiàng)參數(shù)調(diào)到最佳狀態(tài)，以減少斷絲現(xiàn)象。
??? 影響電火花線切割加工工件表面質(zhì)量的因素很多，但只要對(duì)其進(jìn)行系統(tǒng)的分析和科學(xué)的分類，就可以對(duì)這類復(fù)雜而且零亂的因素進(jìn)行控制與調(diào)配，從而改善和提高工件表面質(zhì)量。
??? 3．電極絲損耗分析及措施
??? 數(shù)控電火花線切割加工中，電極絲的損耗或斷絲嚴(yán)重影響其連續(xù)自動(dòng)操作的進(jìn)行，尤其是在高速走絲電火花線切割中，因電極絲在加工中的反復(fù)使用，隨著電極絲損耗的增加，切縫越來(lái)越窄，不僅會(huì)使加工面的尺寸誤差增大；而且一旦在加工中發(fā)生斷絲，加工必須重新開始,這不僅花費(fèi)較多工時(shí)，而且影響加工的表面質(zhì)量。造成電極絲損耗或斷絲的原因及措施有：
???（1）電極絲快速(8～10m／s)移動(dòng)時(shí)和導(dǎo)輪、導(dǎo)電塊產(chǎn)生磨擦，引起導(dǎo)輪和導(dǎo)電塊磨損。長(zhǎng)期使用時(shí)，導(dǎo)輪V型槽底被電極絲拉出溝槽，導(dǎo)電塊長(zhǎng)期使用時(shí)，接觸電極絲的一面也被拉出溝槽。由此造成導(dǎo)絲部位摩擦阻力增大、電極絲由于運(yùn)動(dòng)受阻而斷裂。
?? （2）切除材料發(fā)生偏移切除材料重量大時(shí)，在加工即將結(jié)束時(shí)容易發(fā)生偏轉(zhuǎn)和位移，造成電極絲被卡斷。為此，可在工件和切除材料的平面上添加一塊經(jīng)過(guò)磨削的平面永久磁鋼，以利于切除材料在切割過(guò)程中保持固定位置。
?? （3）工件材料內(nèi)應(yīng)力過(guò)大線切割時(shí)，工件材料內(nèi)應(yīng)力的相對(duì)平衡狀態(tài)受到破壞，容易造成切縫變窄而卡斷電極絲。
?? （4）電極絲損耗線切割加工中，在工件材料被蝕除、切割成型的同時(shí)，電極絲也會(huì)被放電腐蝕，即電極絲發(fā)生損耗。電極絲使用的時(shí)間較長(zhǎng)時(shí)，絲徑變細(xì)且布滿顯微放電凹坑、抗拉強(qiáng)度下降，最終發(fā)生斷裂。一般來(lái)說(shuō)，在測(cè)量絲徑比新絲減少0.03～O.05mm時(shí)，應(yīng)及時(shí)更換新絲。
?? （5）電極絲疊繞電極絲應(yīng)均勻、整齊地繞在儲(chǔ)絲筒上。儲(chǔ)絲筒內(nèi)外圓不同軸時(shí)會(huì)產(chǎn)生不平衡慣量，轉(zhuǎn)動(dòng)時(shí)容易產(chǎn)生疊絲，導(dǎo)致電極絲斷裂。因此，儲(chǔ)絲筒必須經(jīng)過(guò)動(dòng)平衡校正。
除此之外，運(yùn)絲絲杠螺母副間隙太大；工件端面切割條件惡劣； 工作液選用不當(dāng)或者太臟；選擇脈沖電流、脈沖寬度過(guò)大；進(jìn)給速度過(guò)大等等都會(huì)引起電極絲損耗或斷絲，因此，為了防止出現(xiàn)斷絲故障，需要選擇合適的電參數(shù)、定期更換工作液、定期更換導(dǎo)輪、穩(wěn)定裝夾工件并選擇合理的切割路線等。
英文翻譯：
Part of five translation
WEDM in some hard-to-cut materials, special and complex forms processing components than traditional machining method has obvious advantages, it is widely used in moulds, tools, aerospace and other manufacturing processing.
???? According to wire electrode movement in the way that WEDM into WEDM Fast silk and silk WEDM walking, the two have different characteristics and applications. Fast wire WEDM its simple operation, and low cost advantages have been widely adopted. Online cutting process, the impact on the quality and efficiency of processing many factors, the paper with the relevant information on the NC Fast silk WEDM process approach.
一. Machining Principle
1. Electrode wire and workpiece between pulse discharge machining;
???? 2. Electrode wire along its axial movement for Wire;
???? 3. Parts of the electrode wire in the X, Y plane for NC campaign.
二. NC WEDM features
1. Without forming electrode manufacturing workpiece material for less;
???? 2. Easy processing of complex shape of holes, microporous, Narrow;
???? 3. Direct use of semi-finishing and finishing processing forming a quasi-regulatory generally do not regulate quasi-way conversion;
???? 4. Only the graphical outline of the workpiece materials processing, graphics and outside the residuals can also use;
???? 5. A high degree of automation, convenient operation, the processing cycle short, low cost.
三. NC WEDM Application
1. Apply to a variety of shapes Die.
???? 2. Micro-machining can be contoured, narrow shape of the workpiece and complexity.
???? 3. Processing model and molding tool.
???? 4. PM-processing, Xiangpin cavity mode, drawing module, corrugated sheets forming die.
???? 5. Machining of hard materials, cutting thin slices, cutting precious metal materials.
???? 6. Cam processing, special gear.
???? 7. Suitable for small quantities and variety parts processing, and reduce production costs die, shortening the production cycle.
四. NC WEDM Processing
1. Workpiece material selection
???? In order to produce a high dimensional accuracy and surface quality good Wire products must be used by the workpiece material and meticulous consideration:
???? (1) Since different workpiece materials, melting point, gasification, thermal conductivity, etc. is not the same, so in the same way even if the processing and have received the workpiece surface quality is not the same, it must be based on the actual needs of the surface quality of the workpiece material accordingly choice. For example, to achieve high-precision, we must choose carbide materials, the election should not be hardening stainless steel or high-carbon steel, it will be difficult to meet the required demand.
??? (2) Since the workpiece material processing internal residual stress on the impact of larger, in the heat treatment processing of the material, due to the removal of metals and materials will cut processing internal residual stress the relative balance of damage, which could affect parts machining precision and surface quality. In order to avoid such circumstances, should choose forging good, hardenability, and heat treatment of small deformation of materials.
???? 2. Cutting line choice (multiple Cutting)
???? In order to obtain high precision machining can be considered in the Fast Wire WEDM used repeatedly cutting process.
Used repeatedly cutting technology, the first major high-speed stability cutting cutting, it may choose to use the peak current; second cutting is the main task of repair light. Should choose smaller pulse current and pulse width.
???? 3. Wear silk hole and the electrode placed choose Siqi
???? For different parts, processing wear silk hole different positions. In cutting, keyhole-shaped concave Parts, wear silk concave hole should be located in the centre of the hole is easy to wear silk processing location accurate, and easy to control trajectory coordinates calculated in cutting convex or concave-shaped hole - Parts, wear silk hole in the processing should be set up near the starting point, cut to shorten the trip useless, and should be easy to simplify the trajectory control calculations. Also optional perforated silk-hole from the edge of 2-5 mm, as shown. Processing punch, to reduce the deformation of the electrode Siqi cutting trajectory and distance from the edge of movement should be larger than 5 mm.
???? 4. , The choice of parameters
???? Quality of the processing has significant effect on the electrical parameters including pulse current, pulse width, pulse interval, Wan wire speed, usually need to guarantee the quality of the surface, under the premise of dimensional accuracy, as far as possible to improve processing efficiency.
???? Pulse power is affecting the quality of surface machining an important factor. A single pulse energy can be reduced to improve the surface roughness. Decision of a single pulse energy is the main factor pulse width and pulse current. Therefore the use of small current pulse width and pulse will be good surface roughness. However, the smaller the single pulse energy, and cutting speed is slower, if pulse current is too small will not be able to have a discharge cremation, not normal cutting. Generally speaking, finishing, the pulse width can be within 20 μ s choice of processing, in 20 μ s ~ 60 μ s choose.
???? Pulse interval greater impact on the cutting speed, and the surface roughness less affected. Pulse interval smaller unit of time the frequency of EDM more, thus cutting speeds higher. In fact, not too small pulse spacing, or discharge of washouts was too late, discharge gap can not be fully deionization, processing unstable, easily burn the workpiece or broken wires. For larger workpiece thickness, and should be appropriately increased pulse interval in order to fully discharge elimination of product form a stable cutting. General pulse interval in 10 μ s ~ 250 μ s can basically meet within the framework of various processing conditions, stable processing.
???? Wire speed of the processing speed of a certain impact on the Wire with the speed of processing speed will be increased significantly. However, the high-speed wire electrodes will cause greater vibration而使workpiece surface roughness of straightness and deterioration. Therefore, we should guarantee the quality of processed under the prerequisite of a proper choice of a reasonable processing speed fiber walking speed.
???? 5. Other non-electrical parameters choice
??? (1) electrode wire and fiber walking speed choice
???? Generally use ￠ 0.06-0.20 mm of molybdenum wire. Increase the speed to go wire to wire electrode into the larger work of the thickness of the workpiece in the discharge gap is conducive to corrosion product of emissions and discharge machining stability.
??? (2) of the choice and use of
???? Kerosene high dielectric strength, space discharge energy consumption, the energy distribution to less polarization, Paixie difficult as low cutting speeds. But the cold kerosene not obvious change, and the lubricating properties, and therefore not easily broken wires. Saponification of washing performance and to Paixie, high cutting speed.
???? Working fluid emulsion type of energy-saving water than the high-intensity, low compared with kerosene, the weak than water cooling capacity than kerosene, and water and detergent than kerosene is good, compared with non-working fluid emulsion-cutting, high-speed, is the widespread use of working fluid.
???? The purity of the initial use of the work and not the best processing results, and in the use of 1 to 2 working days, metal shavings into the working fluid in a certain degree of dirt mixed in the cutting of this mixture has a good effect . , And periodic replacement of often do not work cleaning fluid me very clean in order to obtain a certain degree of dirty mixture.
五. Common Problems in
1. Five discharge status
??? (1) Open (empty Pulse)
???? No breakdown discharge gap, the gap is greater than the voltage of 50 V, but there is no current gap flow for the empty state (td = ti).
??? (2) spark discharge (working pulse, or effective pulse)
???? Gap, good insulation properties, dielectric breakdown after working solution can be effectively thrown out, in addition to metal corrosion. Waveform characteristics are: voltage on the td, and Ie te waveform on the high-frequency oscillation of small sawtooth waveform.
??? (3) short-circuit (short pulse)
???? Short-circuit directly connecting discharge gap, as the servo system for instantaneous feed too much or discharge gap in the product overlap caused by corrosion. Short-circuit current, larger space, but a very small gap ends of the voltage, not the exception processing corrosion role.
??? (4) arc discharge (stable arc discharge)
???? As Paixie undesirable discharge point on a local rather than decentralized, localized heat accumulation, temperature increases, the vicious circle, this time on a spark discharge arc discharge, a discharge point in the fixed point or a partial, as stability arc, making electrode surface coke burn. Td and waveform characteristics of high-frequency oscillation is a small sawtooth disappeared.
??? (5) the transition arc discharge (unstable arc discharge, or instability spark discharge)
???? Transition arc discharge is a normal spark discharge and stability in the transition state arc discharge, arc discharge is stable precursor. Waveform characteristics of the breakdown delay td little or close to zero, only to become a Jianqi, voltage and current wave of high frequency components as sparse and low variable zigzag. Early detection of a transition arc discharge, to prevent arc burns have great significance.
???? 2. Precision, surface quality analysis and solutions
???? Machine is due to high-speed wire line electrode wire for high-speed reciprocating, the loss of electrodes evenly distributed in the last 300 meters electrode wire, although very small electrode wire loss, but WEDM affect its processing work surface quality of many factors, the need for the processing parameters reasonable matching, the process can guarantee the quality of the workpiece surface.
???? Cutting the line have a direct impact on the quality of the main factors involved in personnel, equipment, materials, and so on. In order to improve the quality of workpiece surface processing, the greatest impact from the human factor, machine factors and material factors to consider three aspects of the processing methods and quality control improved method. Specific methods are as follows:
?? (1) reasonable arrangements for cutting line.
??? (2) correct choice for cutting parameters.
??? (3) close processing.
?? (4) attention to the processing of the workpiece fixed.
??? (5) In processing, must be examined electrode wire electrode wire tension on the surface of the workpiece machining quality had a great impact, high-machined surface of workpiece quality requirements, the wire should be as far as possible, under the premise of improving the electrode wire tension.
??? (6) High-Speed Wire Machine generally use of emulsified oil and water from the work of preparation.
??? (7) must be examined conductive block wear.
??? (8) the check-round rotation, if the rotation should not change, must also be carefully examined, the nozzle extent of the damage and dirt, remove the milk with cleaning fluid, damage to the timely replacement. It should also be regular checks receptacle wire tube silk, silk loss will be affected too large machining accuracy and surface quality.
??? (9) maintain a stable power supply voltage.
??? (10) In accordance with the actual needs of the surface quality of the workpiece materials for the corresponding choice.
??? (11) Processing of the parameters should be transferred to the best condition to reduce the phenomenon of broken wires.
???? WEDM impact of the workpiece surface quality of a number of factors, but as long as its systematic analysis and scientific categorization, and can be complex and disorder of such factors control and deployment, which improve and enhance the quality of the workpiece surface.
???? 3. Loss Analysis and wire electrode measures
???? NC WEDM, electrode wire or broken wires in the depletion of its serious impact on the conduct of continuous automatic operation, especially in the high-speed Wire EDM wire cutting as a result of electrode wire in the processing of repeated use, with the electrode The increase in loss silk, kerf increasingly narrow, not only will the size of the processing of error increases in the processing and once in a broken wires, processing must be re-started, this is not only spend more hours of work, but also affect the processing of surface quality. Loss caused electrode wire or broken wires and the reasons for the measures:
??? (1) electrode wire fast (8 ~ 10 m / s), and mobile-round, conductive block create friction caused guide pulley block and conductive wear. Long-term use, the V-round lead by the bottom of a trench Wire electrodes, conductive block long-term use, the contact electrode wire has been pulled out of a trench. The resulting guide wire increased friction parts, wire electrode movement delay due to fracture.
??? (2) resection of material removal offset the weight of the material, in the processing at the end of the forthcoming high deflection and displacement caused by the electrode wire card off. To this end, and the removal of the workpiece material and adding a plane after the plane grinding permanent magnet, the material removal in order to facilitate the process of cutting to maintain a fixed position.
??? (3) Stress the workpiece material, line cutting, workpiece material, the relative balance of stress damage, making it easy for narrow kerf, and a power wire card.
??? (4) electrode wire cutting line loss, in addition to the workpiece material is corrosion, cut-At the same time, wire electrode discharge will be corrosion, wear and tear is a wire electrode. Electrode wire used a longer time, the wire diameter and filled with fine microstructure changed discharge pit, the tensile strength decreased, and ultimately fracture. Generally speaking, the new measurement wire diameter wire than 0.03 ~ O.05mm reduction, should be the timely replacement of the new wire.
??? (5) electrode wire electrode wire should be stacked around uniform neatly around in the storage cylinder on the wire. Cylindrical different wire barrel Reserve will have a balanced axis of inertia, rotates easily lead Permian silk, lead wire electrode fracture. Therefore, the certificates must be silk tube balancing correction.
??????? In addition, the Advisory Nut shipped fishes and vice gap too workpiece cutting face harsh conditions of work, or the improper selection of Tazang chose pulse current, pulse width too large; feed speeds, and so on will lead to loss or electrode wire broken wires, Therefore, in order to prevent the emergence of broken wires failure, the need to choose the appropriate parameters, and the replacement of regular, periodic replacement guide pulley, stability and the workpiece clamping reasonable choice cutting routes
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