200822998 九、發明說明： 【發明所屬之技術領域】 本發明係有關一種應用於放電加工技術之電極結構， 尤指一種其外周包覆有保護物之電極結構。 【先前技術】 放電加工原理是利用電能轉換成工件所需的熱能，而 使工件急速融熔的一種熱性加工方法。換言之，在作放電 加工時，電極與工件會同時放置在一工作液中，且電極與 工件間相隔一極微細的間隙，而產生過渡電弧放電現象， 進而對工件產生加熱作用，同時，工作液由於受到放電壓 力及加熱作用而產生氣化爆發現象，此時工件的融熔部 份，將伴隨液體氣化現象而進入工作液中，工件因放電的 作用而產生放電痕，如此不斷反覆進行，工件所需之加工 形狀便可完成。由此可知，放電加工與工件的硬度並無關 聯，只要是可通電的材料均可加工。當然，不見得一定需 要使用到工作液，電極亦可直接對工件作放電加工。 如弟3圖所不’為習用之放電加工機’其係將一電極 8 1裝設於一連接裝置8 3，而一工件8 2則設置於一工 作台8 4上，並將電極8 1電性連接於電源8 5之陰極8 5 1，而工件8 2則電性連接於電源8 5之陽極8 5 2， 且電極8 1對著工件8 2間具有一微小間隙。 然而，在加工過程中，電極8 1與工件8 2間會產生 放電作用，電流密度極高的電子流會自電極8 1急速衝擊 工件8 2之加工區域，而使工件8 2急劇受熱而達到熔 5 200822998 點，並且陽離子同時自工件8 2流向極性為陰極的電郎 1，既同時加熱電極8 1，造成電極8丄隨著工件8 2的 加工而產生熔融的碎屑並被逐漸消耗。故，如何在加工' 程中減少電極的消耗率實為本發明研究之 〇工過 【發明内容】 ^ 本發明之主要目的，在於解決上述的問題而提供一種 放電加工之電極結構二，其主要在電極外周包覆_保4蔓物 ，而有效降低在加工過程中工件對電極的熱傳導並減小♦ 極的消耗率。 ^包 本發明之另一目的，其由於電極外周的保護物造成— 月b隙（Energy Gap)的存在’只有能量超過該能隙的電 才能通過此保護物而衝擊至工件之加工區域，可減少~ < 量之熱電子的穿透，增進放電效率。 本發明之又一目的，其藉由改變電極外周之保護物、 厚度，而可控制穿透電流大小。 的 為達前述之目的，本發明之電極外周包覆有—保… "亥保濩物係由複數導電顆粒及複數非導電顆粒相^六物 密佈而成，以供於放電加工中減少該電極的消耗。人錯 本發明之上述及其他目的與優點，不難從下迷所雙 貫靶例之詳細說明與附圖中，獲得深入了解。 I用 當然，本發明在某些另件上，或另件之安排上容^ 所不同，但所選用之實施例，則於本說明書中，有 丁从詳細 6 200822998 說明，並於附圖中展示其構造。 【實施方式】 口月參閱第1圖至第2圖’圖中所示者為本發明所選用 之實施例結構，此僅供說明之用，在專利申請上並不受此 種結構之限制。 μ本實施例之放電加工之電極結構二，該電極工工係裝 叹於-工具夾頭3上，並與欲加卫之卫件2間保持一微小 間隙，電極11電性連接於電源4之陰極，而工件2則電 性連接於電源4之陽極。其中，該電i之外周包覆有 、—保《蒦物1 2 ’該保護物1 2係由複數導電顆粒^ 2 1及 複數非導電顆粒！ 2 2相互交錯密佈而成，以供於放電加 工中減少該電極1 1的消耗。於本實關巾，各該導電顆 氺1 2 1 1 2 3係為金屬，而各該非導電顆粒1 2 2、 1 2 4係為陶瓷，或者其他非金屬材料。 ^本實施例之技術手段在於，放電加工之電極1 1通常 係為金屬類之導電材料’容易在加工過程中受到卫件2對 電極1 1的熱傳導制而消耗電極i i本身，因此在電極 1 1外周包覆-保護物i 2，可有效降低工件2對電極工 1直接的熱傳導，而減少電極1 1被快速消耗。 另外，由於電極1 1通常為金屬類之導電材料，但包 覆於電極1 1外的保護物！ 2則具有導電顆粒工2丄與非 導電顆粒1 2 2 ’因此保護物工2的多層顆粒密佈結構造 ^能隙的存在，當進行放電加工作業時，只有能量超過該 能隙的電子才能穿遂該能輯礙並通過此保護物i 2而衝 7 200822998 擊工件2，故，可減少低能量之熱電子的穿透，有效增進 放電效率。 值得一提的，本發明之電極結構亦可應用於微細放電 加工技術，甚至達到奈米技術領域，使得加工精度大為提 高，改善超微精密加工的窘境。也就是各該導電顆粒1 2 1與各該非導電顆粒1 2 2均為奈米等級，並以奈米技術 交錯密佈於該電極11。 由上述實施例的說明可知，本發明具有下列之優點： 其一，其主要在電極外周包覆一保護物，而有效降低 在加工過程中工件對電極的熱傳導並減少電極的消耗率。 其二，由於電極外周的保護物造成一能隙（Energy Gap )的存在，只有能量超過該能隙的電子才能通過此保護物 而衝擊至工件之加工區域，可減少低能量之熱電子的穿透 ，增進放電效率。 其三，藉由改變電極外周之保護物的厚度，而可控制 穿透電流大小。 以上所述實施例之揭示係用以說明本發明，並非用以 限制本發明，故舉凡數值之變更或等效元件之置換仍應隸 屬本發明之範疇。 由以上詳細說明，可使熟知本項技藝者明瞭本發明的 確可達成前述目的，實已符合專利法之規定，爰提出專利 申請。 【圖式簡單說明】 8 200822998 弟1圖係本發明之放笔加工機局部結構干今图 第2圖係本發明第1圖之電極部分放大示二圖 第3圖係習用之放電加工機結構示意圖 【主要元件符號說明】 (習用部分） 電極8 1 連接裝置8 3 電源8 5 陽極8 5 2 (本發明部分彡 電極1 1 導電顆粒1 2 1 工件2 電源4 工件8 2 工作台8 4 陰極8 5 1 保護物1 2 非導電顆粒1 2 2 $具失頭3200822998 IX. Description of the Invention: [Technical Field] The present invention relates to an electrode structure applied to an electrical discharge machining technique, and more particularly to an electrode structure whose outer periphery is coated with a protective material. [Prior Art] The principle of electric discharge machining is a thermal processing method that uses electric energy required for electrical energy conversion into a workpiece to rapidly melt the workpiece. In other words, during the electrical discharge machining, the electrode and the workpiece are simultaneously placed in a working fluid, and the electrode and the workpiece are separated by a very fine gap, thereby causing a phenomenon of transitional arc discharge, thereby heating the workpiece, and at the same time, the working fluid Due to the discharge pressure and heating, the gasification explosion occurs. At this time, the melted portion of the workpiece enters the working fluid accompanying the liquid vaporization phenomenon, and the workpiece generates a discharge mark due to the discharge, so that the workpiece is continuously repeated. The required machining shape of the workpiece can be completed. From this, it can be seen that the electrical discharge machining is independent of the hardness of the workpiece, and can be processed as long as it can be energized. Of course, it is not necessary to use the working fluid, and the electrode can also directly discharge the workpiece. As shown in FIG. 3, the electric discharge machine is a conventional electric discharge machine, and an electrode 8 1 is mounted on a connecting device 83, and a workpiece 8 2 is disposed on a table 84, and the electrode 8 1 is disposed. The electrode 8 is electrically connected to the cathode 8 5 1 of the power source 85, and the workpiece 8 2 is electrically connected to the anode 8 5 2 of the power source 8 5 , and the electrode 8 1 has a slight gap between the workpieces 8 2 . However, during the processing, a discharge occurs between the electrode 8 1 and the workpiece 82, and the electron current having a very high current density rapidly hits the processing region of the workpiece 8 2 from the electrode 81, and the workpiece 8 2 is heated abruptly. Melting 5 200822998 points, and the cations flow from the workpiece 8 2 to the battery 1 having the polarity of the cathode, and simultaneously heating the electrode 8.1 causes the electrode 8 产生 to generate molten debris with the processing of the workpiece 8 2 and is gradually consumed. Therefore, how to reduce the electrode consumption rate in the process is a work of the present invention. [The present invention] The main object of the present invention is to solve the above problems and provide an electrode structure for electric discharge machining, which mainly The outer circumference of the electrode is coated with _ 4 vines, which effectively reduces the heat conduction of the workpiece to the electrode during processing and reduces the consumption rate of the ♦ pole. Another object of the present invention is that it is caused by the protection of the periphery of the electrode - the presence of an energy Gap - only energy having an energy exceeding the energy gap can be impacted to the processing region of the workpiece through the protective material. Reduce the penetration of ~ < quantity of hot electrons and improve discharge efficiency. Another object of the present invention is to control the magnitude of the penetration current by changing the protection and thickness of the periphery of the electrode. For the purpose of the foregoing, the electrode of the present invention is coated with a protective layer of a plurality of electrically conductive particles and a plurality of non-conductive particles, for the purpose of reducing electrical discharge during discharge machining. Electrode consumption. Human Errors The above and other objects and advantages of the present invention are readily apparent from the detailed description of the preferred embodiments and the accompanying drawings. I use of course, the present invention differs in some of the components, or the arrangement of the other parts, but the selected embodiment is described in the present specification, which is described in detail in 200802998, and in the drawings. Show its structure. [Embodiment] The description of the embodiment of the present invention is made for the purpose of illustration and is not limited by the structure of the patent application. In the electrode structure of the electric discharge machining of the embodiment, the electrode engineering system is attached to the tool chuck 3, and a small gap is maintained between the electrode holder 2 and the electrode 11 to be electrically connected. The electrode 11 is electrically connected to the power source 4. The cathode 2 is electrically connected to the anode of the power source 4. Wherein, the outer periphery of the electric i is coated with a "protective material 1 2". The protective material 12 is composed of a plurality of conductive particles ^ 2 1 and a plurality of non-conductive particles! 2 2 are intertwined and densely formed to reduce the consumption of the electrode 11 during discharge processing. In the actual cover towel, each of the conductive particles 氺1 2 1 1 2 3 is a metal, and each of the non-conductive particles 1 2 2, 1 2 4 is a ceramic or other non-metal material. The technical means of the present embodiment is that the electrode 11 of the electric discharge machining is usually a metal-based conductive material, which is easy to be subjected to heat conduction of the electrode 2 to the electrode 1 1 during processing, and consumes the electrode ii itself, thus the electrode 1 1 peripheral coating-protective i 2 can effectively reduce the direct heat conduction of the workpiece 2 to the electrode 1 while reducing the rapid consumption of the electrode 11. In addition, since the electrode 11 is usually a metal-based conductive material, it is coated with a protective material outside the electrode 11! 2 has the conductive particle 2丄 and the non-conductive particles 1 2 2 'therefore the protective layer 2 has a multi-layered particle structure, and when the electric discharge machining operation is performed, only electrons whose energy exceeds the energy gap can be worn.遂This can interfere with and pass through the protective object i 2 and hit the workpiece 2 in 200822998. Therefore, the penetration of low-energy hot electrons can be reduced, and the discharge efficiency can be effectively improved. It is worth mentioning that the electrode structure of the present invention can also be applied to micro-discharge processing technology, even to the field of nanotechnology, which greatly improves the processing precision and improves the dilemma of ultra-fine precision machining. That is, each of the conductive particles 1 2 1 and each of the non-conductive particles 1 2 2 are of a nanometer grade, and are interlaced to the electrode 11 by nanotechnology. As can be seen from the description of the above embodiments, the present invention has the following advantages: First, it mainly coats a protective material on the periphery of the electrode, thereby effectively reducing the heat conduction of the workpiece to the electrode during processing and reducing the consumption rate of the electrode. Second, because the outer periphery of the electrode protects the existence of an energy gap (Energy Gap), only electrons whose energy exceeds the energy gap can be impacted to the processing area of the workpiece through the protective material, thereby reducing the wear of low-energy hot electrons. Through, improve discharge efficiency. Third, the size of the penetration current can be controlled by changing the thickness of the protective material on the periphery of the electrode. The above description of the embodiments is intended to be illustrative of the invention, and is not intended to limit the scope of the invention. From the above detailed description, it will be apparent to those skilled in the art that the present invention can achieve the above-mentioned objects, and is in accordance with the provisions of the Patent Law. [Brief Description] 8 200822998 1 is a partial structure of the pen processing machine of the present invention. FIG. 2 is an enlarged view of the electrode portion of the first embodiment of the present invention. FIG. 3 is a conventional electric discharge machine structure. Schematic [Description of main component symbols] (conventional part) Electrode 8 1 Connecting device 8 3 Power supply 8 5 Anode 8 5 2 (Partial yttrium electrode 1 1 Conductive particles 1 2 1 Workpiece 2 Power supply 4 Workpiece 8 2 Workbench 8 4 Cathode 8 5 1 protector 1 2 non-conductive particles 1 2 2 $ with a head 3