The transducer application on machine tool of cut of electric spark line

Summary: The control means of electric machinery of canister of machine tool silk uses relay to control normally, but use this means control to be put in a series of malpractice. Transducer is the control that passes pair of alternating current frequency, achieve the goal that controls electromotor rotate speed. Article place narrated a method to make full use of the functional characteristic of transducer, implementation rises circuit is simple, it is good to can safeguard a gender. Reason converts small-power transducer will realize former control way. Keyword: Transducer; Frequency control; IGBT inversion; DSP; PWMThe Transducer Has Application In The W Ire Cut Electro-discharge MachineAN Lian, Xiang ' , HE Xiao-rui, GAO Li-ping. (1. Institute Of Electric Engineering Automation, hebei University Technology, tianjin 3001 30, china; 2. Beijing DM, CUTMachine Tool CO. , beijing 101307, china; 3. Beijing Sanyi Power Electronics Companny, beijing 102613, china) Abstract: Relay Is Always Used In Electrical Motor ' S Contro1. But This Control Mode Has A Series Of Shortcomings. Transducer Is Used To Control The Speed Of Electrical Motor By Changing The Frequency Of AC. This Technique Takes Full Advantage Of The Character Of The Transducer. The Circuitry Is Simplicity. The Maintainability Is Wel1. So The Low Power Transducer Is Used To Carry Out The Former Control Mode. Key Words: Transducer; Frequency Control; LGBT Contravariance; DSP; Line cut machines electric spark of PW M foreword is the main component that electric spark machines, it is to use a metal linear tool electrode (call electrode silk again) along given geometrical graph contrail, the principle that uses pulse discharge to corrode a metal will process work. Walk along machine tool of silk thread cut quickly to be in our country at 70 time arisen progressively and wide application asks at machining precision tall, form is complex, especially the metal such as the mould in treatment. What take machine tool of silk thread cut quickly is electric reach control department to unite kind of cent to be: Part of part of personal computer control, high frequency power source and filar canister electric machinery control a share. Control of filar canister electric machinery controls electric machinery and filar canister partly, drive what molybdenum silk makes fast positive and negative to start move and stop, provide all sorts of corresponding protection functions. Electric control uses other type machine tool normally relay controls fashion, more practical also, but means of this kind of control is existing undermentioned a series of problem: (1) relay contactor movement is frequent, loss is opposite bigger; Intermediate changeover control is complex, give breakdown possibility tall. (2) electric machinery is being started often to total pressure instead, the electric current that start is big, impact of mechanical to filar canister component is big. (3) contactor contact closes often disconnect the noise that cause is big. The main consequence that these problems cause is whole treatment dependability is reduced, burn the problem grow in quantity such as silk, this certainly will brings about fabricating, affect product quality finally, cause needless pecuniary loss. Be aimed at the problem of afore-mentioned existence, reason realizes the improvement of former control means with small-power transducer, its reason basically has the following: (1) maturity of transducer product technology, function is reliable, in already was being applied extensively at asynchronous electric machinery to control a system each. (2) use transducer outside the output terminal that receives control to input terminal and report to run state and powerful can code function, can according to be being accused the object is mixed those who control fashion is different have agile choice and set, leave out complex intermediate changeover control. (3) of electric machinery open stop time and electric current to be able to move encode or automatic setting to finish through the hand respectively, electric current starts in reducing former kind big, machinery pounds big drawback. (4) the appearance sequence switch of main circuit passes transducer interior compositive control circuit is finished (without contact switch) . D.c.braking function still is set inside transducer additionally, and set is when electric machinery rotate speed 0 hind, process of apply the brake can remove automatically, because operate the big electric current with needless susceptive of place of undeserved electric machinery,avoid. (5) transducer still can make up for wave motion of voltage of electrified wire netting by oneself, install automatic delay time to close machine and incoming telegram to continue the function such as treatment, can raise automation rate further. This machine tool introduces Altivar31 series high-powered transducer, power limits from 0. 18 ～ 15KW; Without control of vector of speed sensor magnetic flux; 6 alterable logic input terminal, 3 can configure imitate to input terminal, imitate of 3 logistic ／ outputs terminal, provide control function and protective function. 1 orgnaization walking along silk controls a system to walk along the orgnaization walking along silk of machine tool of silk thread cut quickly, it is the crucial part that affects its to machine quality and treatment stability. The function of orgnaization walking along silk is to drive electrode silk to move by certain linear velocity silk of carry of move back and forth, discharge electrode silk trimly circle on Chu Si canister. Itself of Chu Si canister makes high speed turning reversely, it is to use electromotor positive and negative to come around achieve. Shaft coupling of electric machinery classics drives filar canister, drive guide screw roll via synchronous belt again, procrastinate board make reciprocate, procrastinate board mobile journey but by adjust inverting left and right sides to bump piece the distance will achieve. If the graph is shown 1 times,the machine tool walks along filar orgnaization. Nextpage2 silk canister system of frequency control of frequency control construction of system basically is formed by the following link, block diagram of construction of system shows 2 times like the graph: (1) link of power transformation of main circuit system uses circuit of commutate of AD ／ DC and IGBT inversion circuit. (2) control circuit basically uses control circuit to accept ab extra signal and give out control command and PWM weaveform. (3) drive circuit uses module of IGBT intelligence power (IPM) . (4) protective circuit monitors a gender to protect fast sex of the movement and real time, used hardware circuit to impose the monitoring kind of software subprogram, the if be,attributes and so on of electric machinery short circuit breakdown when breakdown happening, criterion hardware circuit will generate signal instantly, shut undee generator and undertake protective installing in interrupting a subprogram, make the program returns initiative condition. The circuit of system of 3 frequency control designs Chu Sijian to use electromotor of three-phase communication asynchronous to procrastinate move, electric machinery speed undertakes notting have through transducer timing knob extremely timing. 3. The module of commutate of diode of classics of design three-phase alternating voltage of 1 main circuit, the three-phase inverter that evacuation of wave of filter of large electric capacity goes to to be comprised by 6 IGBT, systematic power parts of an apparatus chooses the 3rd acting IGBT and diode of follow on current, by inverter missive the alternating current of alterable frequency furnishs electromotor timing. 3. The design of 2 control circuit uses DSP to serve as controller can the number that utmost ground reduces periphery parts of an apparatus, increase systematic stability. The PWM of main in this design use 1MS32OC24Ox DSP outputs a mouth, reach board on mouth of A ／ D, capture interface CAP. The 6 PWM signal of DSP turns over photograph evacuation through bumper to drive IPM of circuit board drive. If the graph shows 3 times,control construction of system pursues: To the input of mouth of sampling of A ／ D signal did the processing of early days, the signal of direct input is amplitude the volts d.c. signal in 0 ～ 5V, the requirement of can contented DSP to input imitate signal. The vector control of alternating current machine asks to alternating current machine speed undertakes sampling. 3. The design of 3 drive circuit uses module of IGBT intelligence power in the design (IPM) , it is module of a kind of large scale integration, mix power switch parts of an apparatus not only drive circuit is compositive together, and still overvoltage, cross the breakdown such as electric current and overheat to detect circuit is included inside, can protect breakdown signal to send CPU or DSP to undertake handling. 3. The design IGBT of 4 protection circuit is used at electric power alternates, appear easily overvoltage, cross the fault such as electric current, cause the damage of parts of an apparatus, when consequently IGBT is working, must take complete safeguard. These safeguard basically had included to press protection, shed protection and too lukewarm protection too 3 parts. IPM interior is already integrated very careful protection circuit, from electric current protection, voltage protects hot protection. Line cut machines 4 conclusion electric spark efficient, high accuracy and Gao Rou sex are machine tool collect an organic whole, scope of timing of system of requirement electromotor control it is wide, good to add decelerate performance, speed precision is tall, special function (if high speed locates) strong. Transducer controls the application in the system in orgnaization walking along silk, achieve the stepless speed regulation of pair of three-phase asynchronous electric machinery, have sex of machinery of energy-saving, big to scope of free from contamination of electrified wire netting, timing, timing to wait for an advantage forcedly. CNC Milling