Linear servo electric machinery hauls the electric spark forming machine that use
- source:GERHOLD CNC Machining
The control of 0001mm is equivalent make athletic speed of the axis achieves 36m/min below the condition, such technical index makes the electric spark forming machine of new generation holds the integrated condition that provided high rate and precision work concurrently. (1) machines craft brand-newly, craft brought the electric spark take shape that the high speed motion that breaks through traditional technology index axis gives a tradition to change tremendously, this kind changed to be confined to moves because of high speed and shorten not just the time that place of outfit clip, corrective, exact location needs, more important is the high speed leap in realizing treatment (carry knife) . Bouncing (carry knife) it is the step with electric spark necessary form cutting, in appearance complex or deep narrow model in antrum treatment, do not take leap (carry knife) waiting for measure with strong fluid cannot be machined almost. But bouncing (carry knife) when without discharge phenomenon, it is electric spark treatment is medium " go-slow " phenomenon, affected the utilization rate of handling time. Fast leap (carry knife) make " go-slow " phenomenal time shortens, raised the utilization rate of time and treatment rate thereby. In the meantime, high speed is bouncing (carry knife) also hop to increase (carry knife) extent created a condition, make the fluid active force of clearance of the discharge when treatment got sufficient improvement, absolved the processing developing fluid when rough machining completely, and make handling time shortens arrive original 1/2. Graph 1 be what avoid processing developing fluid with fast leap is deep narrow model antrum machines example (treatment hind is fore-and-aft sliver) , the section dimension of electrode is 1mm × 38mm, electrode taper 1 ° , model antrum deepness 70mm, electrode material is black lead, two electrode. 5h of total handling time, among them 160min of rough machining time, ra is surface roughness of surface of the workpiece after treatment 2 μ M. Graph the advantage of 1 linear servo is in not only deep narrow model the treatment of antrum gained revolutionary headway on technology index, and functional domain is all-time also widen. Graph 2 it is a Y model (3 blade profile) electrode treatment is deep narrow model the model of antrum machines example. Y (3 blade profile) the ply of electrode only 0.
25mm, in the traditional idea of people, the treatment of such figure has the difficulty that comparative. Deepness exceeds 10mm to be regarded as reserve, the treatment deepness of this treatment example is 40mm, what it makes clear linear servo is practical change, make we entered traditional penalty area easy to doly. Graph 2(2) stabilizes the assurance of finish machining, tall in the electric spark forming machine of the servo dc servo that answers speed, tall stable treatment, linear electric machinery and slide formed unifinication structure. Accordingly, the shift of slide is the direct shift of linear electric machinery, both between extremelying He Chuan gives link. Such, go in servo motion the loss besides the link intermediate and answer lag. Graph the contrast of the 3 statement positions that are rod of linear servo movement and real position concerns, can see from which, in electric spark treatment this kind of special reversible servo moves in, trends answers time to be in only millisecond amount class. Accordingly, the high speed of linear electric machinery answers system and electric machinery of traditional servo of dc of pass on coming back to drive the systematic photograph of ball guide screw to compare, raised an amount level. Graph 3 well-known, in the finish machining process that machines in electric spark, electrode and workpiece are not contacted, the effective discharge clearance between them only ten micron, traditional servo electric machinery and system of ball guide screw are existing to count the 10 lag to about a hundred millisecond between instruction pulse and real position, the efficiency of finish machining discharge that implementation stability, flowing servo carries taller is very difficult. The advantage of linear servo got be reflectinged adequately in process of finish machining of electric spark little space. The acceleration that the high speed that counts millisecond only is answered and is more than 1g can, ensured can realize electric spark to discharge of microcosmic process little space durative, make utilization rate of finish machining pulse rises substantially, make the treatment speed of finish machining got rising in the flowing servo motion of linear servo then. (The athletic way of linear servo decided the comprehensive measure that 3) implements rigid control and long-term precision to maintain a gender its servo unit must use component of linear position feedback to detect as the position link, this is only way. Accordingly, the control of linear servo and drive may be the system of a complete closed circuit only, detect directly the linear shift of slide, do not have the pitch error of guide screw among them, without the backlash error of guide screw and shaft coupling, also avoided transmission catenary spare parts wear away wait for interference element. What move point-blank is oriented also used the scroll guide that answers speed photograph as high as linear electric machinery to suit, use integratedly of these measure, the rigid control that realized a machine tool and long-term precision maintain a gender. (4) is slow fast the average servo rate that the characteristic of the form cutting of flowing drive electric spark of small feed is treatment is slow. Horary feed distance has a few millimeter only when rough machining, horary feed is apart from when finish machining only zero millimeter is slower even. This machines servo to have good dynamic character with respect to requirement electric spark, in order to suit frequent apply the brake, retrorse with the little space that holds tool and work. Ask the system has flowing drive performance then, and must solve the effect that normally the alveolar effect place of AC electric machinery causes. For this, the control equivalent of the linear servo of sanded Dick company and drive equivalent are 0.
1 μ M, used high density rare land when making linear electric machinery at the same time kind permanent magnet regards magnetic field as material. In magnetic body distributing arrange on, adopted strewn at random the permutation that distributing method (show) 4 times like the graph, together with uses what match with photograph of electric machinery function, can undertake to each phase current subtle pilot frequency conversion communicates drive system, this a series of methods ensure acquire the most reasonable magnetic field phasic relation and reasonable electric current are phasic relation, thereby utmost ground balanced linear electric machinery the thrust between winding of each photograph armature, overcame dynamic load and the difficult problem that big range rate changes, make the bad influence of alveolar effect fell lowest, make servo motion is achieved smooth. Graph of forming machine of electric spark of 43 as linear as the relevant technology of linear servo form a complete set servo come out the tremendous function latent capacity that reachs its place to show, be opposite undoubtedly by tens of thousands the user fashioned powerful appeal, stimulate each manufacturer to contend for photograph development and newer product necessarily in order to contend for the market. But, the commercial process of linear servo machine tool is divided outside must solving article aforementioned to concern technical difficulty, still must solve a series of relevant technologies with linear servo form a complete set. (1) perpendicular slide (Z axis) because gravitational balance and lock axis are linear the character of high speed motion of servo and tall quicken character, decided this system to cannot serve as gravitational equalizer in order to weigh the means of hammer. Its reason depends on becoming slide (Z axis) when athletic acceleration is more than 1g, the free whereabouts of heavy weight dogs impossibly the ascendant motion of slide, lost balance action namely. Accordingly, equalizer used the Z rod of sanded Dick company the orgnaization of air cylinder type (the 5) that be like a graph, the atmospheric pressure in relying on air cylinder achieves gravitational balance. This one device is like next advantages: When ① machine tool is in working status, the bearing action with because baric equalizer is right gravitational slide, electric machinery job is in condition of small power comsumption, it is only when fast leap, electric machinery just enters the moving state of high-power; ② atmospheric pressure makes the Suo Zhougong of vertical axis can be changed reliably evenly. After driver breaks phone, instantaneous of perpendicular slide gravity is in free whereabouts condition, traditional electromagnetism locks up what the axis causes slide extremely easily because of behavioral lag right now to move by accident, it is from beginning to end to maintaining the position and the influence that machine precision very those who puzzle a person, baric equalizer and baric clamp will make the lock is decided reliable. Graph 5(2) main shaft is self-prossessed reach its to bearing the character of high speed motion of linear servo and tall quicken character, make main shaft self-prossessed the tool electrode that goes up in main shaft head with suspension is quickening instantaneous happening " overweight " or " weightlessness " phenomenon. If machining some instantaneous when, main shaft makes fast jumping with the acceleration of A, criterion the instantaneous gravity W=m(g+a) of the tool electrode that right now quality is M. Gravitational change creates enormous pressure to systematic drive necessarily. Accordingly, in ensure stiffness of main shaft head while, what give attention to two or morethings reduces main shaft is self-prossessed appear crucial. Have weight the makings of actor select material that light, heat is out of shape diminutive is versed in material of synthetic pottery and porcelain is to achieve afore-mentioned goals. But notable is, of the product practical change a process to make clear, the magnetic field power that responds gender and strict semmetry to distributing with the high speed of the linear slideway of form a complete set of photograph of steep drive system, mix to flowing drive it is more important to prevent slide to suffer force displacement. Accordingly, be located in main shaft to a pair of of two side linear electric machinery and a pair of positions of linear slideway are designed and find a place for debug craft must correct, with achieving power quits, be helpful for obtaining linearity the drive with tall, flowing good sex. Gravitational change is mixed to the output force of drive system the clamping force with heavy headstock raised taller requirement. The system of linear electric machinery that sanded Dick company makes outputs force to be able to amount to 3000N, the drive principle of linear electric machinery and traditional AC electric machinery are identical, can complete the design development that matchs with CNC software quickly. The clamping apparatus that covers suitably with servo of linear electric machinery is in with traditional system bearing below same situation, the structure designs solidder, clamping force and safe surplus bigger, can suit in the round from the smallest the filament electrode of a few micron, narrow muscle electrode is machined to the servo of the flowing stability of large electrode of the heaviest 50kg. (Slide structure already experienced the XY cross of the forming machine of electric spark of slide ram structure of 3) fixed workbench and XY axis tens of year practical course, convenient sex already was the mechanical tigidity that its move, pilot people place is accepted, its structure design and workmanship also employment is adult already. But, because the form cutting of workpiece immerses to undertake in working fluid, the character of high speed motion of linear servo machine tool and tall quicken character to cause working fluid likely spill over and splatter, the workbench that does not allow a machine tool so is mobile, this secures the reason of workbench to be in namely. The treatment servo of electric spark form cutting is direction is reversible. The fixed direction of this and cutting servo differs completely. Because this is sanded,the cutting machine tool such as the slide ram structure of the XY axis of the linear servo machine tool of Dick company and numerical control mill or machining center is widely divergent, even with certain the slide ram structure of commercial already electric treatment machine tool is disparate also. If regard main shaft head and slide ram a rigid whole, it must have chief broad measure to be more than the appropriate scale of high dimension. Main shaft head with slide fixed face should have ample area not only between ram, have enough height even. Such ability avoid what when servo is machined, be out of shape because of machinery and arise to answer lag (6) seeing a picture. Graph between the double slideway of 6 slide and ram due as far as possible big span, in order to get enough bearing is apart from. The X axis of machine tool of sanded Dick company is slide, y axis is ram, every axis has the slideway span that is more than 1m respectively, the servo that can get used to fixed workbench adequately, bouncing, function that achieves with outline joltily asks. Linear electric machinery and linear servo are in 4 conclusion the application on electric spark forming machine, make the economic target that machines craft happened to rise revolutionarily, it represented electric spark to machine the development trend of tooling. The commercialization in machine tool of servo of linear electric machinery and practical in changing a course, must solve a series of difficulty and perfect to it the relevant technology of form a complete set. CNC Milling