MD550Z - Process current generator for dimensional electrochemical machining - Google Patents

Process current generator for dimensional electrochemical machining Download PDF

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Publication number
MD550Z
MD550Z MDS20110131A MD550Z MD 550 Z MD550 Z MD 550Z MD S20110131 A MDS20110131 A MD S20110131A MD 550 Z MD550 Z MD 550Z
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Moldova
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transformer
diodes
dimensional electrochemical
common point
secondary winding
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Romanian (ro)
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Valeri Sirvo
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Im Uzina Topaz S A
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Publication of MD550Z5 publication Critical patent/MD550Z5/en

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Abstract

The invention relates to process current generators for machine tools, which provide the dimensional electrochemical machining of turbine blades of compressors.The process current generator for dimensional electrochemical machining contains a three-phase half-controlled rectifier (1) to which is connected a controlled inverter (2), to which, in turn, is connected the primary winding of a power high-frequency low-profile transformer (3), the magnetic circuit of which is made of nanocrystalline alloy GM 414-2. The secondary winding of the transformer (3), made stamped single-turn, is connected to the buses of the current leads (4 and 5) for connection to tool electrodes (6). To the secondary winding of the transformer (3) are connected diodes (7), connected into a common point (A), which is connected to the bus of the current lead (10) for connection to the work part (8). Between the common point (A) of diodes (7) and the tool electrodes (6) are connected capacitors (9).

Description

Invenţia se referă la generatoarele de curent tehnologic pentru strungurile, care asigură prelucrarea electrochimică dimensională a paletelor pentru turbinele compresoarelor. The invention relates to technological current generators for lathes, which ensure the dimensional electrochemical processing of blades for compressor turbines.

Generatoare modulare de profil jos de curent tehnologic asigură producerea energiei de înaltă frecvenţă cu densitate mare (de la sute de kilowaţi până la megawaţi într-un impuls) în zona de dizolvare anodică a materialului din care este confecţionat semifabricatul paletei pentru turbina cu gaze. Low-profile modular generators of technological current ensure the production of high-frequency energy with high density (from hundreds of kilowatts to megawatts in a pulse) in the anodic dissolution zone of the material from which the gas turbine blade blank is made.

Este cunoscut un generator de impulsuri unipolare pentru realizarea procedeului de prelucrare electrochimică dimensională, care constă din generatorul de lucru şi generatorul de impulsuri tăiate. În generatorul de lucru ieşirea transformatorului de coborâre este conectată la interstiţiul dintre electrozi printr-o punte de redresare şi un tiristor de putere. Dispozitivul de încărcare cu filtru al generatorului de impulsuri tăiate este conectat printr-un tiristor de încărcare cu condensatorul de comutare, care printr-un tiristor de comutare este conectat cu tiristorul de putere al generatorului de lucru [1]. A unipolar pulse generator for carrying out the dimensional electrochemical machining process is known, which consists of a working generator and a chopped pulse generator. In the working generator, the output of the step-down transformer is connected to the gap between the electrodes through a rectifier bridge and a power thyristor. The filter charging device of the chopped pulse generator is connected through a charging thyristor to the switching capacitor, which through a switching thyristor is connected to the power thyristor of the working generator [1].

Dezavantajele generatorului cunoscut constau în pierderile active în generator şi durata suboptimală a frontului anterior de impulsuri, care nu trebuie să depăşească 100 µs pentru satisfacerea cerinţelor înaintate faţă de calitatea suprafeţei prelucrate electrochimic dimensional. The disadvantages of the known generator consist in the active losses in the generator and the suboptimal duration of the leading pulse front, which must not exceed 100 µs to satisfy the requirements set for the quality of the dimensionally electrochemically processed surface.

Este cunoscută, de asemenea, o sursă de curent tehnologic a strungului pentru prelucrare electrochimică, executată pe baza unui bloc de putere, care include un redresor trifazat, ieşirea căruia este conectată la intrarea unui invertor dirijat, care, la rândul său, este conectat la intrarea unui transformator de putere de înaltă frecvenţă şi în continuare la un redresor secundar de putere [2]. A technological current source of the lathe for electrochemical processing is also known, made on the basis of a power block, which includes a three-phase rectifier, the output of which is connected to the input of a controlled inverter, which, in turn, is connected to the input of a high-frequency power transformer and further to a secondary power rectifier [2].

Energia electrică de mare densitate se transferă sarcinii prin intermediul barelor de alimentare, ce cuplează ieşirea sursei de curent tehnologic. În acest caz, lungimea barelor de alimentare depinde de dimensiunile geometrice ale surselor de curent tehnologic şi poate ajunge până la câţiva metri. The high-density electrical energy is transferred to the load via the power supply bars, which couple the output of the technological power source. In this case, the length of the power supply bars depends on the geometric dimensions of the technological power sources and can reach up to several meters.

Mai este cunoscută o sursă de curent tehnologic, la baza căreia se află schema dublorului de curent, care include o sursă de tensiune, un transformator de putere de înaltă frecvenţă cu impulsuri, înfăşurarea secundară a căruia este conectată la sarcină prin intermediul a două drosele, diode şi al unui condensator [3]. There is also a known technological current source, based on the current doubler scheme, which includes a voltage source, a high-frequency pulse power transformer, the secondary winding of which is connected to the load through two chokes, diodes and a capacitor [3].

Dezavantajele acestei surse de curent tehnologic constau în pierderile de energie în borne şi barele de alimentare, care cresc la pătrat în funcţie de majorarea lungimii acestora, precum şi reducerea calitativă şi cantitativă a diapazonului de transmitere a energiei de înaltă frecvenţă cu creşterea lungimii barelor de alimentare. The disadvantages of this technological current source consist in the energy losses in the terminals and supply bars, which increase squared as their length increases, as well as the qualitative and quantitative reduction of the high-frequency energy transmission range with increasing supply bar length.

Problema, pe care o rezolvă invenţia, constă în reducerea pierderilor de energie şi excluderea modificării diapazoanelor de energie şi de frecvenţă a energiei transmise de înaltă frecvenţă, precum şi reducerea distanţei dintre ieşirile generatorului de curent tehnologic pentru prelucrarea electrochimică dimensională şi sculele-electrozi. The problem, which the invention solves, consists in reducing energy losses and excluding the modification of the energy and frequency ranges of the transmitted high-frequency energy, as well as reducing the distance between the outputs of the technological current generator for dimensional electrochemical processing and the electrode tools.

Generatorul de curent tehnologic pentru prelucrarea electrochimică dimensională, conform invenţiei, înlătură dezavantajele menţionate mai sus prin aceea că conţine un redresor trifazat semidirijat, la care este conectat un invertor dirijat, la care, la rândul său, este conectată înfăşurarea primară a unui transformator de putere de înaltă frecvenţă de profil jos, circuitul magnetic al căruia este confecţionat din aliaj nanocristalin de tip GM 414-2, iar înfăşurarea secundară a transformatorului, executată ştanţat cu o singură spiră, este conectată la nişte bare de alimentare pentru unirea cu sculele-electrozi, totodată la înfăşurarea secundară a transformatorului sunt conectate nişte diode, unite într-un punct comun, care este conectat la o bară de alimentare pentru unirea cu piesa de prelucrat; între punctul comun al diodelor şi sculele-electrozi sunt conectate nişte condensatoare. The technological current generator for dimensional electrochemical processing, according to the invention, eliminates the disadvantages mentioned above by containing a three-phase semi-conductive rectifier, to which a directed inverter is connected, to which, in turn, the primary winding of a low-profile high-frequency power transformer is connected, the magnetic circuit of which is made of nanocrystalline alloy type GM 414-2, and the secondary winding of the transformer, made stamped with a single turn, is connected to some power bars for connection with the electrode tools, at the same time, some diodes are connected to the secondary winding of the transformer, connected in a common point, which is connected to a power bar for connection with the workpiece; some capacitors are connected between the common point of the diodes and the electrode tools.

Rezultatul tehnic obţinut constă în excluderea modificării diapazoanelor de energie şi de frecvenţă a energiei de înaltă frecvenţă care se transmite, reducerea pierderilor de energie în barele de alimentare, reducerea distanţei dintre ieşirile generatorului de curent tehnologic şi sculele-electrozi, precum şi în obţinerea concordanţei necesare a caracteristicilor de impedanţă ale generatorului şi sarcinii complexe în formă de celulă electrochimică, care este formată din sculele-electrozi, camera de presiune, umplută cu soluţie electrolitică, şi piesa supusă prelucrării - paleta turbinei cu gaze. The technical result obtained consists in excluding the change in the energy and frequency ranges of the transmitted high-frequency energy, reducing energy losses in the power supply bars, reducing the distance between the outputs of the technological current generator and the electrode tools, as well as in obtaining the necessary correspondence of the impedance characteristics of the generator and the complex load in the form of an electrochemical cell, which consists of the electrode tools, the pressure chamber filled with an electrolytic solution, and the workpiece to be processed - the gas turbine blade.

Invenţia se explică prin desenul din figură, care reprezintă circuitul electric al generatorului de curent tehnologic pentru prelucrarea electrochimică dimensională. The invention is explained by the drawing in the figure, which represents the electrical circuit of the technological current generator for dimensional electrochemical processing.

Generatorul de curent tehnologic conectat la reţeaua de putere de 380 V şi frecvenţa de 50 Hz conţine redresorul trifazat semidirijat 1, la ieşirile căruia este conectat invertorul dirijat 2, care formează trenuri de impulsuri ale tensiunii cu diapazon de milisecunde din impulsuri dreptunghiulare ale frecvenţei purtătoare cu diapazon de microsecunde, şi care efectuează modularea curentului în înfăşurarea primară a transformatorului 3 de putere de înaltă frecvenţă de profil jos cu circuitul magnetic din aliaj nanocristalin de tip GM 414-2, şi care este conectat cu înfăşurarea primară la ieşirea invertorului dirijat 2. The technological current generator connected to the 380 V and 50 Hz power network contains the three-phase semi-directed rectifier 1, to the outputs of which the directed inverter 2 is connected, which forms trains of voltage pulses with a millisecond range from rectangular pulses of the carrier frequency with a microsecond range, and which performs current modulation in the primary winding of the low-profile high-frequency power transformer 3 with the magnetic circuit made of nanocrystalline alloy of the GM 414-2 type, and which is connected with the primary winding to the output of the directed inverter 2.

Înfăşurarea secundară a transformatorului 3, executată ştanţat cu o singură spiră, prin intermediul barelor de alimentare 4 şi 5 este conectată la sculele-electrozi 6, iar diodele 7 sunt conectate la paleta supusă prelucrării 8 a turbinei cu gaze printr-o bară de alimentare 10. Barele de alimentare 4, 5 şi 10 sunt executate în formă de benzi din cupru, între care este situat un strat termoizolant, de exemplu imidoflex. The secondary winding of the transformer 3, made in a stamped form with a single turn, is connected to the electrode tools 6 by means of the power bars 4 and 5, and the diodes 7 are connected to the processed blade 8 of the gas turbine by means of a power bar 10. The power bars 4, 5 and 10 are made in the form of copper strips, between which a thermal insulation layer, for example imidoflex, is located.

La punctul comun A al diodelor 7 sunt conectate unele dintre contactele condensatoarelor 9, iar celelalte contacte sunt conectate la sculele-electrozi 6. To the common point A of the diodes 7, some of the contacts of the capacitors 9 are connected, and the other contacts are connected to the electrode tools 6.

Generatorul de curent tehnologic funcţionează în modul următor. The process current generator operates in the following mode.

Tensiunea reţelei trifazate de 380 V se furnizează prin redresorul trifazat semidirijat 1 şi se transformă în tensiune continuă cu valoarea de cca 500 V, care se transmite la invertorul dirijat 2, care transformă această tensiune într-o consecutivitate de impulsuri cu diapazon de microsecunde cu durata de cca 10 µs şi spongiozitate minimă de cca 2,4. The three-phase network voltage of 380 V is supplied through the three-phase semi-directed rectifier 1 and is transformed into a direct voltage with a value of approximately 500 V, which is transmitted to the directed inverter 2, which transforms this voltage into a sequence of pulses with a microsecond range with a duration of approximately 10 µs and a minimum sponginess of approximately 2.4.

Din această consecutivitate de impulsuri microsecundare la comanda blocului de control şi dirijare (pe desen nu este indicat) se formează trenuri de impulsuri cu o durată, care se află într-un diapazon de milisecunde, determinat de procesul tehnologic pentru prelucrarea electrochimică dimensională, şi care se află în diapazonul de la 300 µs până la 3 ms. From this sequence of microsecond pulses at the command of the control and management block (not shown in the drawing), pulse trains are formed with a duration that is in the range of milliseconds, determined by the technological process for dimensional electrochemical processing, and that is in the range from 300 µs to 3 ms.

Consecutivitatea impulsurilor milisecundare pe frecvenţa purtătoare a diapazonului microsecundar este transmisă la transformatorul 3, şi mai departe prin barele de alimentare 4 şi 5 se transmite la sculele-electrozi 6, iar prin diodele 7 - la paleta supusă prelucrării. Între sculele-electrozi 6 şi punctul comun A al diodelor 7 sunt incluse condensatoarele 9, care asigură condiţiile de transmisie optimală de energie. The sequence of millisecond pulses on the carrier frequency of the microsecond tuning fork is transmitted to the transformer 3, and further through the power supply bars 4 and 5 it is transmitted to the electrode tools 6, and through the diodes 7 - to the pallet being processed. Between the electrode tools 6 and the common point A of the diodes 7, capacitors 9 are included, which ensure the conditions for optimal energy transmission.

Astfel, energia de înaltă frecvenţă cu densitate mare prin trenuri cu durată milisecundară de impulsuri bipolare ale frecvenţei diapazonului microsecundar prin câmpul magnetic se transmite la transformatorul 3. Thus, high-density high-frequency energy through millisecond-duration trains of bipolar pulses of the microsecond tuning fork frequency through the magnetic field is transmitted to transformer 3.

În acest caz durata reglabilă a trenurilor de impulsuri bipolare este comensurabilă cu timpul stabilirii potenţialelor pe electrozi pentru materialele respective, iar impulsurile curentului de polaritate inversă contribuie la sporirea productivităţii şi preciziei de prelucrare electrochimică dimensională cu reducerea esenţială simultană a rugozităţii (până la 0,2 µm). In this case, the adjustable duration of bipolar pulse trains is commensurate with the time of establishing potentials on the electrodes for the respective materials, and the reverse polarity current pulses contribute to increasing the productivity and accuracy of dimensional electrochemical processing with the simultaneous essential reduction of roughness (up to 0.2 µm).

Mai jos este prezentat un exemplu cu diapazonul energetic şi de frecvenţă a impulsurilor de tensiune/curent, formate de generatorul dat pentru prelucrarea profilului paletei cu o suprafaţă de 333 cm2 a turbinei cu gaze, care se aplică în zona de prelucrare la sculele-electrozi: Below is an example of the energy and frequency range of voltage/current pulses formed by the given generator for processing the blade profile with a surface area of 333 cm2 of the gas turbine, which is applied in the processing area of electrode tools:

diapazonul tensiunilor impulsurilor cu frecvenţă purtătoare şi ale trenurilor de impulsuri de 5...40 V; voltage range of carrier frequency pulses and pulse trains of 5...40 V;

diapazonul curenţilor impulsurilor dreptunghiulare cu frecvenţă purtătoare şi ai trenurilor de impulsuri de 5...50 kA; the range of currents of rectangular pulses with carrier frequency and of pulse trains of 5...50 kA;

durata impulsurilor cu frecvenţă purtătoare de 10 µs; pulse duration with carrier frequency of 10 µs;

- durata frontului/căderii impulsurilor cu frecvenţă purtătoare de 2 µs; - duration of the front/fall of pulses with carrier frequency of 2 µs;

- diapazonul spongiozităţii trenurilor de impulsuri de 3...1000.- the range of sponginess of impulse trains is 3...1000.

1. RU 2177391 C1 2001.12.27 1. RU 2177391 C1 2001.12.27

2. Лаборатория силовых источников. Универсальные мощные источники питания "ГОРН", http://www.power2000.ru/, 2010.12.16 (regăsită în internet 2012.07.23) 2. Laboratory of power sources. Universal power supplies "GORN", http://www.power2000.ru/, 2010.12.16 (found on the Internet 2012.07.23)

3. Laszlo Balogh. The Current-Doubler Rectifier: An Alternative Rectification Technique For Push-Pull And Bridge Converters. DN-63, Unitrode Corporation, Texas Instruments Incorporated, 1999 3. Laszlo Balogh. The Current-Doubler Rectifier: An Alternative Rectification Technique For Push-Pull And Bridge Converters. DN-63, Unitrode Corporation, Texas Instruments Incorporated, 1999

Claims (1)

Generator de curent tehnologic pentru prelucrarea electrochimică dimensională, care conţine un redresor trifazat semidirijat (1), la care este conectat un invertor dirijat (2), la care, la rândul său, este conectată înfăşurarea primară a unui transformator (3) de putere de înaltă frecvenţă de profil jos, circuitul magnetic al căruia este confecţionat din aliaj nanocristalin de tip GM 414-2, iar înfăşurarea secundară a transformatorului (3), executată ştanţat cu o singură spiră, este conectată la nişte bare de alimentare (4 şi 5) pentru unirea cu sculele-electrozi (6), totodată la înfăşurarea secundară a transformatorului (3) sunt conectate nişte diode (7), unite într-un punct comun (A), care este conectat la o bară de alimentare (10) pentru unirea cu piesa de prelucrat (8); între punctul comun (A) al diodelor (7) şi sculele-electrozi (6) sunt conectate nişte condensatoare (9).Technological current generator for dimensional electrochemical processing, which contains a three-phase semi-conductive rectifier (1), to which is connected a directed inverter (2), to which, in turn, is connected the primary winding of a low-profile high-frequency power transformer (3), the magnetic circuit of which is made of nanocrystalline alloy type GM 414-2, and the secondary winding of the transformer (3), made stamped with a single turn, is connected to some supply bars (4 and 5) for connection with the electrode tools (6), at the same time, to the secondary winding of the transformer (3) are connected some diodes (7), connected in a common point (A), which is connected to a power bar (10) for connection with the workpiece (8); between the common point (A) of the diodes (7) and the electrode tools (6) are connected some capacitors (9).
MDS20110131A 2011-07-15 2011-07-15 Process current generator for dimensional electrochemical machining MD550Z5 (en)

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