Milling of inclined shaft electric spark machines research pre-test

It Includes The Study Of The Basic Machining Conditions, the Design Of The Essential Experimental Devices And The Investigation Of The Effect Of Some Factors On Metal Removal Rate(MRR) And Electrode Wear(EW) .

The Factors Are Electrode Diameters, electrode Rotating Speeds And Electrical Parameters.

Key Words:EMilling of electric spark of 　 of Lectro-discharge Milling(EDM);Aided Tilting Shaft;Electrode Roatating Speed is machined (also call electric spark to achieve treatment) , it is method of a kind of new-style electric spark treatment. It is to use the simple tube shape that high speed rotates or strong record electrode to make three-dimensional or treatment of 2 dimension outline, like CNC Milling, need to make complex figuration electrode no longer. Method of this kind of treatment and photograph of electric spark processing are compared, have electrode of economic and many figuration, production charge of cycle weak point, treatment low, treatment is flexible and advanced advantage. Current, abroad already had production of much home company to issue the machine tool of electric spark finished product that has milling function, and the research of domestic this side still is in start level. Electrode high speed rotates, it is the characteristic that electric spark milling machines. As similar as common and mechanical milling, electric spark milling is machined, according to electrode runner shaft coming back tilt the position, can divide again for vertical scroll of painting or calligraphy, cross axle and milling of inclined shaft electric spark. Be put when horizontal stroke of electrode axis level or inclined when putting, the opposite feed of electrode and workpiece moves, can make 3 axes linkage come true by the X of machine tool of numerical control electric spark, Y, Z, OK also make linkage come true by the whirligig of axis of the X of machine tool of numerical control electric spark, Z2 and workpiece. Former the side direction that is used at big diameter cylinder or conic spare parts normally is three-dimensional model the treatment of the face, place is electrode of sincere ball head commonly with electrode. And latter application is wider. To the cylinder of big diameter or conic spare parts, the stage of outline of the helix of its side direction chamfer, 2 dimension or hole, all can adopt latter treatment method, use hollow and columnar electrode to try to come true. The article grinds beforehand in the light of some aviation namely the specific target of the helix chamfer on taper seat of Baobi of small taper of difficult treatment of big diameter of project Zhong Mou, 2 dimension stage, to milling of inclined shaft electric spark treatment makes one initial exploration. The thin wall spare parts of the postulate aviation big diameter of milling of inclined shaft of 1 implementation electric spark, in its the regular meeting on side direction wall has hole of a few different 2 dimension, stage, chamfer, this kind of spare parts accepts the restriction such as oil groove of electric spark machine tool, can set upright an axis to place only commonly, apparent, face of these different treatment uses machining method, because data is hard treatment and spare parts tigidity are poor wait for an element, be very difficult treatment. Using electric spark inclined shaft or treatment of cross axle milling is feasible, effective treatment method. The electric spark milling that should realize different of side direction of this kind of spare parts extent is machined, must have the feed orgnaization that realizes feed of servo of spare parts Zhou Xiang. For this, design of our proper motion is made give a large numerical control to rotate workbench, the mesa diameter of this workbench makes an appointment with 650mm, the placement of can contented general and large part needs. The main drive of this component deputy the synchronous tooth form that compares for big slowdown takes drive deputy. Tooth form takes transmission to have drive the smooth, good point that grows without apparent backlash, life. When electric spark is machined, servo feed function can affect the stability that machines a process greatly. Because workpiece diameter is bigger, electric machinery drive rotates the workpiece that installs on workbench turns one very small angle, can give the generation on direction bigger feed arc length in Zhou Xiangjin, make treatment produces excessive feed. Consequently, the function of low speed drive of drive electric machinery becomes an influence to rotate workbench servo smooth stability and the key that machine index. For this, we chose property of medium, low speed good, and as comfortable as photograph of system of power source drive the Japan that match produces communication servo electric machinery. The pulse resolution of this electric machinery is 2500 pulse / turn, if press overall diameter to be the workpiece computation of 650mm, arc length of the smallest feed is about 0.

04mm. The experiment makes clear, equivalent of this one the smallest feed, the feed that the Zhou Xiangjin when milling of inclined shaft of basic contented electric spark gives asks, treatment feed is smooth. Want to realize treatment of milling of inclined shaft electric spark, the accessory of milling of special electric spark that still must deserve to clip holds inclined shaft to place electrode, electrode rotating clamp first, rotate in order to realize the high speed of tubal shape electrode, high-pressured strong oil and adjust electrode axes banking angle to spend. Design of our proper motion, make the electrode rotating clamp that go out first, basically also use synchronous tooth form to take drive, its rotate speed can undertake modulatory through simple circuit. Electrode rotates precision demand is higher, must very small radial beats with axial change is moved, still ask to have the very good sealing that prevent oil. Structure of experiment of milling of whole electric spark, if pursue,1 is shown. Graph we chose composition of a picture of form of test of milling of electric spark of 1 inclined shaft the NF40 power source of Japanese Sodick company controls ark, made corresponding butt joint transform to the machine tool. This are electronic-controlled ark, control function is strong, electric parameter is rich, can realize treatment of 3 axes linkage. What require numerical control process, can finish in the work out on this machine, OK also have the aid of is finished at work out of system of process designing of other computer CAD/CAM hind, transplant to come up to this machine again, perhaps have communication contact through exterior interface directly. Milling of electric spark of 2 craft experiment is machined, make one axial feed first with electrode mostly, on hypostatic workpiece treatment goes out one cylindrical hole begins, this cylindrical the deepness of hole is called beforehand feed deepness. Treatment of milling of inclined shaft electric spark basically suffers electrode material, dimension, electrode to rotate force of material of speed, workpiece, strong hydraulic pressure, beforehand parameter of feed deepness, report (the influence of the element such as Ip) of electric current of the To between wide Ti of arteries and veins, arteries and veins, peak value. This experiment basically studies diameter of Ip of electric current of the To between wide Ti of arteries and veins, arteries and veins, peak value, electrode, electrode rotates speed is right the treatment corrode of common steel material divides speed and electrode the influence of opposite loss. Full trial uses red copper, 45 steel electrode is right; Beforehand feed deepness is 3mm; Working fluid is kerosene; Force of strong oil pressure is 1.

5MPa; Experiment rotate the diameter is 450mm; Lose polarity to machine. Test equipment sees a picture 1. The experiment uses only factor method. (The milling of influence electric spark that wide Ti of 1) arteries and veins divides speed Vw and electrode loss θ to machining corrode is machined, because tool electrode high speed rotates, often develop fluid with high pressure, the performance that discharge bits is good, treatment is stabler, the ratio of the To between wide Ti of reason arteries and veins and arteries and veins is 3:1 surely roughly, electrode external diameter is 10mm, internal diameter is the hollow and columnar violet copper pipe of 3mm. Electrode rotate speed coming back spends N ＝ 300r/min. Test result is shown 2 times like the graph. Graph the influence experiment of wide Ti of 2 arteries and veins to Vw, θ discovers, as the accretion of wide Ti of arteries and veins, corrode increases gradually except speed Vw, treatment surface surface roughness also increases gradually, because the energy of individual pulse also increases gradually,this is. And the accretion as Ti, electrode drops gradually relative to loss θ . (The Ip of electric current of influence peak value that Ip of electric current of 2) peak value divides speed Vw and electrode loss θ to corrode also is the main parameter that affects energy of individual pulse discharge, its experiment to the influence of Vw and θ , see a picture 3. Graph the influence experiment of Ip of electric current of 3 peak value to Vw, θ discovers, increase as Ip gradually, vw rises gradually, but Ip is too big, machine not quite stable, observe from discharge weaveform, the weaveform that pull arc and form of empty carrier wave have increase, consequently, vw drops somewhat instead. This explains, correspondence is spent at different rotate speed coming back, different electrode diameter, ip of due and corresponding electric current of optimal peak value, accordingly, as the accretion of Ip, θ increases gradually, when Ip is more than 45A, electrode surface has burn sign. (The milling of influence electric spark that D of 3) electrode external diameter divides speed Vw and electrode loss θ to corrode is machined, should integrate the structure of specific spare parts commonly, choose the tubal shape of corresponding diameter or strong record electrode. The effect that studies D reachs θ to Vw very be necessary. Its test result is shown 4 times like the graph. Graph the influence experiment of D of 4 electrode external diameter to Vw, θ discovers, as the accretion of D of electrode external diameter, vw also increases gradually, this and discharge area increase, pulse utilization rate rises about; But after D is more than 12mm, the accretion of Vw is not quite apparent, very apparent, this is main the limitation as a result of pulse energy. Accordingly, as the accretion of D, electrode drops gradually relative to loss θ . D is too small, tool electrode wall is large too thin, current density is too big, consequently, electrode is opposite loss is severe. (One of features of milling of influence electric spark that 4) electrode rotate speed coming back spends N to divide speed Vn and electrode loss θ to corrode, the high speed that is electrode rotates. Electrode high speed rotates, those who be helpful for the platoon bits that machines a process and treatment is stable. Electrode rotate speed coming back spends N to experiment to the influence of Vw and θ , see a picture 5. Graph 5 electrode rotate speed coming back spends N to experiment to the influence of Vw, θ discovery, it is the red copper electrode of 10mm to external diameter, as the addition of N, vw also increases accordingly, but after N is more than 300r/min, n is not quite apparent to the influence of Vw. This explains, to the electrode of some diameter, one make accordingly machine stable, efficient basic rotate speed. As the addition of N, electrode drops gradually relative to loss, after N is more than basic rotate speed, the impact is very little. After this and rotate speed rise considerably, high pressure is opposite to fluid machine an area erode action increases, effect of electrode plating Fu is abate about. 3 conclusion 　 (1) uses homebred lead plane, match with advanced and electronic-controlled system and the numerical control that design by oneself rotate workbench and special electrode rotating clamp first, can realize treatment of milling of inclined shaft electric spark conveniently. (2) is complex to big diameter thin wall, apply milling of inclined shaft electric spark to machine a method, it is effective and feasible selection method. (When milling of inclined shaft of 3) electric spark, main report parameter reachs electrode except speed Vw to machining corrode the influence rule of opposite loss θ , with the likeness when electric spark processing. (4) experiment whole process discovers, can bigger impact machines electrode loss precision of the appearance of the face, dimension. The real time that studies electrode loss further detects and compensate, very be necessary. CNC Milling