1、 Wire EDM Technology Abstract: With the continuous improvement of machinery manufacturing and the need for precision processing, advanced machinery manufacturing technology also matter of course. In this paper, EDM wire cutting technology and its application and development trends. Key words: Mechan
2、ical manufacturing technology, EDM wire cutting 0.Preface Manufacturing technology is not only a measure of a country an important indicator of the level of technological development is the focus of international technological competition. Machinery manufacturing technology is the study of product d
3、esign, production, processing, manufacturing, selling and use, maintenance services and even the whole process of recycling the engineering disciplines, is to enhance quality, efficiency, competitiveness as the goal, including material flow, information flow and energy flow complete system works. Wi
4、th the development of society, the requirements for products, great changes have taken place, asked to diverse species, update to speed, quality to high-end, the use to be convenient, the price must be reasonable and appearance to appearance, higher degree of automation, service better, more and mor
5、e to meet the requirements necessary to adopt advanced machine manufacturing technology. The characteristics of advanced manufacturing technology: (1) it is the 21st century technology. (2) it is the technology for indust of micro-hole slot, narrow, arbitrary curves, with allowance of small, high pr
6、ecision, short production cycle, manufacturing highlight the advantages of low cost, has been widely apprial applications. (3) it is to harness the production process systems engineering. (4) it is a technology for global competition. (5) it is the unity of the three elements of market competition.
7、However, EDM wire cutting technology is one of advanced manufacturing technology, mechanical production and wide application, it is mainly used for processing a variety of complex shapes and precision small parts, for example, Die punch, die, punch and die, fixed plate, stripper plate and so on, for
8、ming cutter, model, EDM machining the metal electrode, a varietylied in production, the current account abroad WEDM EDM over 60% of the total. The following highlights WEDM machining technology and application of principles and development trends. 1. Principles of WEDM WEDM (Wire cut Electrical Disc
9、harge Machining, referred to as the WEDM), sometimes also known as cutting. The basic physical principle is the presence of free positive ions and electrons to accumulate, and soon to be ionized to form a conductive channel. In this stage, a current between two plates, lead to numerous collisions be
10、tween particles occur, forming a plasma, and soon increased to 8000 to 12,000 degrees Celsius, melting moments in the two conductors, some of the material at the same time, the electrode and dielectric fluid vaporized, forming a bubble, the rules and it increased until the pressure is very high. And
11、 current interruption, the temperature suddenly drop, causing the bubble implosion, the momentum generated to melt the material thrown into the crater, and then the material is corrosive fluid in the dielectric re-condensed into a small ball, and was discharged dielectric fluid. NC-controlled then t
12、he monitoring and control, servo bodies, so that the phenomenon of uniform discharge to achieve the processing of materials to be processed, making it meet the requirements of size and shape precision products. On this basis, our domestic development of the Fast Wire System (HS). Europe and Japan, d
13、eveloped the walking system (LS). The main difference is 1, the electrode wire of tungsten and molybdenum alloy wire used, the foreign use of brass. 2, by specification of the working fluid, demonized water used abroad. 3, take the wire of the speed of 11 meters / second or so, abroad for 3 to 5 m /
14、 min. 4, we repeat the electrode wire is to use until the broken wire to the foreign is not reused after the walk. 5, our precision than in other countries. According to the electrode wire running at different speeds, and processing quality of different WEDM is usually divided into three categories:
15、 the first is to go wire speed WEDM (WEDM-HS), the electrode wire for high-speed reciprocating motion, generally take the wire speed of 8 10m / s, the electrode wire can be reused, the higher processing speed, rapid walking easily lead to the electrode wire and reverse wire jitter when the pause, th
16、e decline in the quality process is the production and use of the main machine species, but also our unique WEDM model； second is the low-speed WEDM wire walk (WEDM-LS), the electrode wire for low-speed one-way movement, generally take the wire speed is lower than 0.2m / s , no longer in use after d
17、ischarge electrode wire, smooth, uniform, small jitter, processing, better quality, but the processing speed of lower production and use is the main foreign models. The third class to go wire-speed WEDM and accurately should be called multi-speed to go wire. Is our original, and its principle is to
18、cut the work piece repeatedly, beginning with fast speed wire tube, strong high-frequency to cut, as the current Fast thread cut, the last knife wire tube with a slower rate than weak high-frequency current to repair light, thereby enhancing the processing finish； and wire-speed reduction, the guide
19、 wheel and bearing less jitter, precision is also increased； In addition, the first knife to cut the fastest speed, then cutting and cutting the amount of light repair is very small, therefore, generally Mito time together cut the knife than the speed wire cut faster. Trajectory based on the control
20、 of the electrode wire in different forms, can be divided into three WEDM: one is an imitation of shape control, before cutting the conducting wire, pre-create the same shape as the die and the workpiece, the processing time rough and die while the workpiece clamping in the machine table, the electr
21、ode wire in the cutting process closely for the trajectory moves close to the edge mode, thereby cutting out the shape with the mold and precision parts to the same； the other is the optical tracking control, the conducting wire cutting before amplification under a certain percentage of part drawing
22、s depict an optical tracking map, the processing machine will be placed in optical pattern tracing stage, the stage of the optical head tracking to follow the ink line graph is always trajectory, then by means of electrical, mechanical linkage, the control machine table with the workpiece relative t
23、o the movement of the electrode wire to do similar figures to cut out shapes with the same pattern to the workpiece； another one is the digital process control, advanced digital automatic control technology, the drive machine according to the geometric shape of the workpiece before processing parame
24、ters based on pre-programmed processing of the NC machining program automatically, without making look like board and need not draw Enlargement, two forms of control than the previous higher precision and wide range of applications, more than 95% at home and abroad WEDM have adopted CNC. Direct Digi
25、tal Control (DNC) EDM wire cutting system can improve the level of automation, the overall productivity and responsiveness. 2. WEDM Characteristics and Application The so-called EDM wire cutting, is to move forward to the filament (diameter of about 0.5mm or less) to make electrodes, the electrode w
26、ire and the spark discharge between the workpiece and simultaneously driven by the shape of the parts required for processing. 2.1.WEDM characteristics: (1) it 0.03 0.35mm metal wire to the electrode tool, do not need to create a specific shape of the electrode. (2) Although the process is mainly fl
27、at shape of the object, but in addition to the decision of the inside of the wire diameter foot minimum diameter R (radius + wire discharge gap) such restrictions, no restrictions, no complicated at the beginning of all can be processed. (3) contouring less than the required processing can be effect
28、ive in saving precious materials. (4) loss of wire can be ignored (using low-loss high-speed cutting away Siqie pulse power； slow walk for a continuous thread cutting one-way wire, always kept in the processing area Sijia new electrode), high precision (5) relies on a tiny computer-controlled electr
29、ode wire traces and space compensation, while both concave and convex mold processing, the gap can be adjusted. (6) by emulsion liquid or to the working fluid from the water, do not have to worry about fire, day and night, no one can be a continuous process. (7) cutting WEDM can be difficult to mach
30、ine or can not be the traditional method for processing high hardness, high strength, high brittleness, high-Ren Xing and other conductive materials and semiconductor materials. (8) at the beginning of any complex parts, as long as the preparation of processing can be processed, and thus very suitab
31、le for small batch production of parts and test products, processing, short processing cycle, application flexibility. (9) with four simultaneous axes, can be processed, the following special-shaped body, the shape distortion of the body surface, such as variable taper and spherical parts. (10) process, the tools are not in direct contact with the workpiece, there is
