Koninklijke Philips Corporation N.V.

U.S. Philips Corporation

Viktor Nikolaevich Kucenko

Nasich Zijatdinovich Gimaev

Rafail Ramzisovich Muchutdinov

Igor Leonidovich Agafonov

Aleksandr Leonidovich Belogorsky

Aleksandr L Belogorskij

Aleksandr N Zajcev

Alexandr Nikolaevich Zajcev

Natalya Markelova

Naila A Amirchanova

Rinat A Alimbekov

The invention relates to a method, an apparatus and a computer program for electrochemical machining where a removal of cathode depositions is performed in a fully automated way by means of an application of optimal pulses of a suitable polarity. The method comprises establishing an optimal pulse duration for pulses of the inverse polarity for a removal of the cathode depositions from an electrode surface during the electrochemical machining, said optimal pulse duration being determined from a first calibration carried out preceding the machining of the work piece and a second calibration carried out during the machining of the work piece; performing a control of the machining of the work piece by means of a monitoring of an actual value of an operational parameter and comparing said actual value of the operational parameter to a preset value of the operational parameter, applying a pulse of the inverse polarity of the optimal pulse duration in case the actual value of the operational parameter is greater than the preset value of the operational parameter. The operation of the apparatusin a machining mode is controlled by a process control means C. The operation of the apparatusin an electrode cleaning mode is controlled by the control system Carranged to remove the cathode depositions from the surface of the electrode in real time.

Method, an apparatus, a control system and a computer program to perform an automatic removal of cathode depositions during a bipolar electrochemical machining

A method and an arrangement () for determining an actual value of the gap () between the work piece () and the electrode () during a process of electrochemical machining. According to the invention first process control means () are arranged to supply a set of machining current pulses (Im) to the electrode and the work piece. Second process control means () are arranged to perform a measurement of an operational parameter (U) representing a value of the gap () in real time under operational conditions. The second process control means () comprise means to determine the actual value of the gap () based on the measurement of the operational parameter and logical unit () to actuate the positioning means () to translate the electrode () in case the measured value of the gap deviates from the preset value of the gap.

Method and an arrangement to determine a running value of the gap during the electrochemical machining

A method of electrochemically machining an electrically conductive workpiece in an electrolyte by applying electrical pulses between the workpiece and an electrically conductive electrode, one or more machining pulses alternating with passivation voltage pulses for depositing passivation layers on the workpiece. The amplitude of the passivation voltage pulses is adjusted during an adjustment procedure in which the amplitude of the passivation voltage pulses is increased gradually from zero to the voltage at which the workpiece starts to dissolve in the electrolyte. After each voltage increase the resistance of the gap between the electrode and the workpiece is measured. The voltage value for the highest gap resistance is stored in a memory and used during further machining. The time span of the passivation voltage pulses may be divided into time slices and for each time slice the voltage is adjusted for maximum gap resistance during that time slice.

Method of and arrangement for electrochemical machining

Method of electrochemically machining an electrically conductive workpiece (2) in an electrolyte by applying bipolar electric pulses between the workpiece (2) and an electrically conductive electrode (6), one or more current pulses of normal polarity alternating with voltage pulses of opposite polarity. The amplitude (Un) of the voltage pulses is adjusted between two predetermined values (Un1, Un2) derived from the occurrence of a given surface quality of the workpiece (2) and the occurrence of wear of the electrode (6). The derivation is effected by means of at least one test which precedes the machining of the workpiece (2). During the test the amplitude (Un) of the voltage pulses is increased gradually from an initial value to a final value. The two predetermined values (Un1, Un2) are determined upon the occurrence of a sign reversal in the difference between successive values of a parameter which is representative of a property of a gap (5) between the electrode (6) and the workpiece (2). The parameter may be the amplitude (Umin) of a global minimum in the voltage across the gap (5) during the current pulses, which global minimum results from an oscillatory movement of the workpiece (2) and the electrode (6) relative to one another. The parameter may also be the integral (Qn) of the current across the gap (5) during the voltage pulses; or the integral (Fp) of the voltage across the gap (5) during the current pulses; or the resistance across the gap (5); or the size (St) of the gap (5).

Method and apparatus for electrochemical machining by bipolar current

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Ufa, Russia

Viktor Nikolaevich Kucenko