Line cut machine tool reachs process designing brief introduction

Numerical control device and servo, 2.

Not be to rely on mechanical energy to carry work of cutting tool cutting, be machined however with form of report, hot energy. Electric spark treatment is more mature craft in non-traditional machining. Be in civil, wide application had been won in door of Department of Defense Production and scientific research, equipment of its machine tool finalizes the design quite, and the type is more, but the characteristic that moves relatively by the tool in process and workpiece and utility will divide, can divide roughly it is 6 kinds big, apply among them the widest, the amount is more is machine tool of electric spark processing and machine tool of cut of electric spark line. Machine tool of cut of electric spark line introduces here. Treatment of cut of  electric spark line is use on foundation of electric spark treatment linear electrode (molybdenum silk or cupreous silk) rely on scintilla discharge to have cut to workpiece, reason calls cut of electric spark line, sometimes abbreviation line cut. Controlling a system is the main component that undertakes cut of electric spark line is machined, the labor intensity that precision of the stability that controls a system, dependability, control and automation degree affect treatment technology index and worker directly. One, the classification of machine tool of phyletic CNC Machining of CNC Machining and non-traditional machine tool has two kinds of methods: 1.

By control systematic classification has bit of position control, linear control, successive control 3 kinds, 2.

By servo classification has system of open loop, half closed circuit, closed-loop control. Traditional cutting machines a method to basically rely on mechanical energy to excise metallic stuff or metalloid material. As the development of industrial production and science and technology, produced a variety of non-traditional machining methods that use other energy form to undertake machining, advocate if point to,use the electric energy, chemical energy, sound energy and light energy method that will undertake machining directly. Here, the application of the energy form beyond mechanical energy is a when non-traditional machining distinction machines at the tradition prominent symbol. New energy form is direct action at material, make treatment produced a lot of characteristic, for example, hardness need not be more than the tool that treatment uses to be machined the hardness of material, this makes the treatment of material of tall hardness, high strenth, tall tenacity becomes easy; Be like again, in machining a process, between tool and workpiece nonexistent striking mechanical cutting force, make imperceptible treatment becomes a possibility thereby. Be these characteristics, made non-traditional machining method achieve very great progress, apply extensively already at the industry such as aerospace, electron, motivation, electric equipment, appearance, machinery at present. Non-traditional machining sort basically presses the different classification of its energy source and working principle, basically have: Report, heat energy: Electric spark treatment, electron beam treatment, plasma bundle treatment; Report, mechanical energy: Ionic bundle of treatment; Report, chemical energy: Electrochemical machining, electroanalysis polishing; Report, chemical, mechanical energy: Electroanalysis grinding, electroanalysis honing, zincous mechanical grinding; Smooth, heat energy: Laser beam machining; Chemical energy: Chemical treatment, chemical polish; Sound, mechanical energy: Ultrasonic treatment; Mechanical energy: Abrasive eject treatment, abrasive sheds treatment, liquid eject treatment. Electron beam and ionic bundle of treatment and the compound treatment that machine means with a few kinds at the same time. 2, line cut machines principle of treatment of cut of electric spark line and essential condition electric spark is to use tool electrode (molybdenum silk) with workpiece polar between the report of the generation when pulse discharges corrodes a phenomenon to undertake to workpiece dimension is machined. Electric spark corrodes main reason: Two electrode are stood by in insulation liquid when, because the microcosmic surface of two electrode is uneven, its electric field distributings inhomogenous the electric field that leaves so that protruding dot is in recently is spent highest, extremely medium by puncture, form discharge channel, electric current rises quickly. Below electric field action, the negative electron high speed inside the passageway runs quickly to positive pole, ion runs quickly to cathode to form scintilla discharge, electron and ion collide each other when the high speed below electric field action moves, positive pole and cathode surface are shed the bombard that flows with ion respectively by the electron, make heat source of instantaneous high temperature is formed inside electrode clearance, passageway center temperature achieves 10000 degrees of above. As a result is local metallic stuff fuses and aerification. Treatment of cut of electric spark line can move normally, must have following requirement: 1.

Of molybdenum silk and workpiece be machined certain clearance must hold between the surface, the width of clearance is decided by the treatment condition such as capacity of working voltage, treatment. 2.

When machine tool of cut of electric spark line is machined, must undertake in the liquid medium that has certain insulation property, if kerosene, saponification is oily, go ionic water, the requirement teachs tall insulating properties is for benefit at producing pulse sexual scintilla discharges, liquid medium still has exclude child of corrode of the report inside clearance and cooling electrode effect. Molybdenum silk and workpiece are machined certain clearance holds between the surface, if gap is too big, extremely voltage cannot the medium between puncture pole, cannot produce electric spark discharge; If space is too little, form short circuit link easily, also cannot produce electric spark discharge. 3.

Must use pulse power source, namely scintilla discharge must be pulse sex, intermittence, graph 1 in Ti is pulse interval, Tp to be pulse cycle for pulse width, To. Inside pulse interval, make clearance medium eliminates ionization, make next pulse can be in polar a puncture discharge. 3, cut of electric spark line and forming machine are distinguished 1. The tool electrode of cut of electric spark line is the line electrode that moving along electrode silk axes, electrode of forming machine tool is to shape electrode, the part that with the requirement treatment gives has suit sectional or appearance. 2. The tool when line cut is machined and workpiece in the level two direction have opposite servo feed to move at the same time, forming machine workpiece and tool have an opposite servo feed to move only. 4, machine tool of cut of electric spark line is comprised 1. Machine tool main body: Lathe bed, silk wearing, orgnaization walking along silk, X, workbench of Y numerical control 2. Working fluid system 3.

High frequency power source: Produce high frequency and rectangular pulse, width of the amplitude of pulse signal, pulse can work according to differring state adjustment. 4.

Numerical control and servo 5, the applied 　 that line cut machines 1. Apply extensively at machining all sorts of die. 2. Can machine imperceptible abnormity aperture, narrow seam the workpiece 　 　 with complex form 3. Section mould and shape cutting tool. 4. Model of treatment powder metallurgy, set go all out model the antrum model, model that pull silk, ripple board shapes modular 　 　 5. Machine chip of horniness material, cut, material of cut precious heavy metal. 6. Machine cam, special gear. 7. Agree with the treatment of spare parts of small lot, much breed, reduce a mould to make charge, shorten production is periodic. 6, process designing has two kinds of kind in the editor in numerical control machine tool, one kind is manual process designing, another kind is automatic process designing. Artificial process designing uses all sorts of maths methods, use common computational tool, the data that requires artificially to process designing place has processing and operation. To simplify process designing works, using a computer to undertake automatic process designing is inevitable trend. Automatic process designing uses language of appropriative numerical control to reach all sorts of input methods to input necessary appearance and dimension data to the computer, use special application software to be able to get each to deliver coordinate of point of tangency and the data that compile machine program place to need. 1. Format of process designing of machine tool of cut of line of manual process designing is form of the statement that use 3B: If process designing format expresses 1 to show, the B in the watch is separator, its action is a X, Y, J these numbers are apart, facilitating computer identifies. When the program is inputted toward controller, after reading in the first B, it makes controller has made the preparation that accepts J value, the preparation that accepts value of Y axis coordinate has been made after reading in the 2nd B. The preparation that accepts J value has been made after reading in the 3rd B. When machining diagonal, the X in the program, Y must be the coordinate value of terminus of this inclined line segment relative to start. When machining circular arc, the X in the program, Y must be the coordinate value of circular arc start relative to its the centre of a circle. The numerical value of X, Y, J all is an unit with Um. (1) . G of the direction that note number and J of the length that note number want the circular arc of treatment to assure place or line segment can press the length treatment of the requirement to come out, machine tool of common thread cut is to pass control to arrive from start the total length of feed of a certain workbench comes to terminus achieve. Because this established a J to note number in the computer implement will undertake noting number, spend the workbench feed overall length that machines this line segment namely the numerical value of J beforehand buy enters J tally in, should be to write down several length certainly when treatment the workbench of this coordinate every feed one pace, j tally is decreased 1. Such, reduce zero hour when J tally, express this circular arc or already machined terminus point-blank. A way that when machining inclined line segment, must grow quite with feed distance makes feed control, the terminus that is like line segment is A (Xe, ye) , when | Xe | > | Ye | , the direction that note number takes Gx, conversely, the direction that note number takes Gy, if two coordinate value is same when, criterion two direction that note number all but. When coordinate of circular arc terminus stands by Y axis, computation direction takes Gx, when standing by X axis, 1000 direction take count Gy, already circular arc takes terminal coordinate absolute value to be the direction that note number smally. If pursue,3 are shown. The length that note number is linear or circular arc is umbriferous on reference axis of the direction that note number length summation. To inclined line segment, when ｜ Xe | > | Ye | When, take J ＝ | Xe | , conversely, take J ＝ | Ye | , to circular arc, it may span a few quadrant, if pursue, circular arc is arrive from A B, seal counts direction to be G X after, x3 of J of ＋ of X2 of J of ＋ of X1 of J ＝ J, the direction that note number is G Y, y3 of J of ＋ of Y2 of J of ＋ of Y1 of J ＝ J. (2) . Machining instruction Z Z is treatment instruction omnibus symbol, it shares 12 kinds, if the graph is shown 4 times, among them circular arc instruction has 8 kinds, SR expresses to arrange a circle, NR expresses to go against a circle, the number at the back of the letter states the start of this circular arc is in quadrant, if SR1 expresses to be suitable circle for this circular arc, start is in the first quadrant. Express with L to processing an instruction point-blank, the number at the back of L shows the quadrant that this line segment is in. What close to be being weighed with coordinate is linear, x axis is L 1 Y axis is L L of axis of 2 negative X 3 it is L to lose Y axis 4. When process designing, classmates want to notice, the distinction that coordinate of line cut process designing is fastened and coordinate of numerical control lathe, CNC Milling fastens, department of coordinate of line cut process designing is fastened relative to coordinate only, every machine a line segment or circular arc, want to move coordinate origin to the centre of a circle of sharp starting point or circular arc. Process designing citing machines outline, among them O dot is nodded to remove a knife, course taking a knife is OK from OA, AB, BC, CD, DE, EF, FA, AO, OK also from OA, AF, FE, ED, DC, CB, BA, AO, by OA, AB, BC, CD, DE, EF, FA, AO course process designing is as follows: OA of take the air line: AB of take the air line: BC of take the air line: CD of take the air line: B0B20000B20000GYL2 　 walks along circular arc DE: EF of take the air line: B0B20000B20000GYL4 　 walks along circular arc FA: AO of take the air line: B0B20000B20000GYL4 　 asks classmates to try to think along OA, AF, FE, ED, DC, CB, BA, AO course how process designing. 2. Automatic process designing machines a course to input the computer to mix the message in the design, should use certain automatic programming language (numerical control language) will convey, make source program. After source program is inputted, necessary processing and computational job rely on application software (the compiler that is aimed at numerical control language) will come true. The processing program of the numerical control programming language here basically divides for 3 parts: (1) inputs code to be machined directly; (Code of 2) draw translate into is machined; (3) sweeps code of tracing form translate into to machine. The input of automatic process designing according to process designing information and computer are different to the processing means of information, cent is the method of automatic process designing that is a foundation with automatic programming language and the method of automatic process designing that are a foundation with computer plot. It is method of automatic process designing with the language, when process designing process designing personnel is the process designing manual that uses numerical control language according to place and hardware design, with the form of the language expression gives the entire content of treatment, undertake handling in inputting these content to the computer next, make the NC that can be used at numerical control machine tool directly machine program. It is a foundation with computer plot method of automatic process designing, process designing personnel first the CAD function of software of automatic process designing, compose builds a geometrical figure, use CAM function ever since, set good geometry parameter, ability makes a NC machine program. More commonly used now CAD/CAM software has Mastercam, Pro/e, UG to wait, software of automatic process designing uses machine tool of cut of metalworking center line homebred CAXA. 1, workpiece material and spare parts of work of mould of semifinished product 　 are used commonly forging semifinished product, treatment of its line cut often is in quench as junior as temper travel. Because suffer material oil to show sexual effect, mix when metal of large area purify when cutting off treatment, can make material interior leftover the relative balance position of stress is destroyed and generation is out of shape, the influence machines precision, create material in cut process even abrupt craze. To reduce this kind of effect, except should choose when the design forging good, temper by dipping in water shows performance quality good, heat treatment is out of shape little alloy tool steel (like Cr12, Cr12MoV, CrWMn) outside making mould material, forging to mould semifinished product reach heat treatment craft to also should undertake correctly. 2, the preparative working procedure of base of model of 　 of working procedure of modular base preparation is to show punch or sunken model are online the full treatment working procedure before cut is machined. (1) the preparative working procedure of sunken model 1) next makings cut off place to require data with sawing machine. 2) forging improve in-house organization, and the form that forge wants into place. 3) anneal is eliminated forging internal stress, improvement machines function. 4) dig (mill) dig 6, leave grinding surplus 0.

4 ～ 0.

6mm. 5) grind grind a fluctuation plane and photograph adjacent two flank, to angle square. 6) underline contour line of lay off point and aperture (screw, sell the aperture, aperture that wear silk to wait) the position. 7) treatment aperture part is become when sunken standard is older, process a volume to reduce line cut, need will model mill of part of aperture leakage makings (car) piece, cut point height; Show the stuff with poor sex to temper by dipping in water, but will model the partial data purify of aperture, leave surplus of cut of 3 ～ 5mm.

8) screw of aperture treatment treatment, sell the aperture, aperture that wear silk to wait. 9) quench amount to design requirement. 10) grind grinding fluctuation plane and photograph adjacent two flank, to angle square. 11) demagnetization is handled (2) the prepares punch of working procedure 　 preparation working procedure of punch, but the structural characteristic according to punch, consult the preparative working procedure of sunken model, the working procedure take out that will not need among them can. But, should notice the following: 1) hold clip to facilitate treatment is mixed, cause semifinished product forge the parallelepiped commonly. Identical to dimension, appearance, the punch with section lesser dimension, can become moulding of a few protruding a semifinished product. 2) enough cut surplus should leave between the cut contour line of punch and semifinished product flank (do not be less than 5mm commonly) . On semifinished product even put apart outfit places place. 3) fall in some circumstances, to prevent semifinished product of the model when cut generation is out of shape, want to machine an aperture that wear silk on modular base. Of cut introduce a program to begin from the aperture that wear silk. CNC Milling