SU1235675A1 - Method of detecting contact of electrodes in electrochemical working - Google Patents

Description

The invention relates to electrophysical and electrochemical processing methods, and specifically to methods for detecting contact of electrodes during electrochemical processing. The purpose of the invention is to improve the accuracy of fixing the touch; by adding a signal to the metal contact of the electrodes.

Fig. 1 shows current-voltage characteristics of the interelectrode gap and current and overvoltage pulses; in fig. 2 shows a DC voltage measurement circuit; Fig. 3 shows a constant current measurement circuit.

FIG. Figure 1 shows the current-voltage characteristics (curves 1 and 2) with different ohmic resistances of the interelectrode gap, a bipolar current pulse, whose forward and reverse half-wavelength pulses are different, and the constant component is zero (curve 3), and pulses of the measured voltage at different values of the resistance of the interelectrode charge (curves 4 and 5

On the curves marked: U - for example

polarization effect;

- amplitude

right half wave; 1 „5p is the amplitude of the reverse half-wave, T is the repetition period; t, p, to5p- durations of the forward and reverse half-wave of the current,,, SnP / 2, Sogp, are the areas bounded by the abscissa axis and curves of the voltage of the forward and reverse half-waves for different values of the resistance of the electrode gap p, UoSpi, oSp amplitudes of forward and reverse voltages for different values of the interelectrode charge.

The average voltage (constant component) at the interelectrode gap (FIG. 1) depends on the polarization voltage.

and (and + g 1 „,) n - (and„ + + g,) (1-n),

where n tnp / T,

g - equivalent resistance

interelectrode gap. In this case, the amplitude value of the voltage on the electrodes changes with the change in the resistance of the interelectronic gap, for example, when

electrodes, while the voltage of the voltage does not change, i.e.

YORP 1

Bp 9bc9

 const ,,

0

20

ts

25

35

40

thirty

45

50

55

In the absence of polarization voltage, the average voltage is zero if the pulses of one polarity have the same proportion of increased amplitude and reduced duration with respect to the pulses of the other polarity (i ,, g (1-п).

The measurement circuit of the DC component and the DC component of the current (Fig. 2 and 3) contain the source b - the pulse current of alternating forward and reverse half-wave alternating pulses, the interelectrode gap 7, the integrating chain 8, the amplifier 9, the indicator 10 zero, source 11 voltages of alternating forward and reverse half-wave pulses, inductance 12 and shunt 13.

(The method is implemented as follows.

A device can be used with and: a current point 6 or voltage source 11

Depending on the measurement circuit used, the current from source 6 or the voltage from source 11 goes to the interelectrode gap 7. The measured voltage or current from shunt 13 is smoothed in the integrating chain 8, amplified in the amplifier 9 and supplied to the indicator 10 zero.

In the presence of an interelectrode gap, its volt-ampere characteristic corresponds to curves 1 and 2, while the polarization voltage is applied in the case. The indicator 10 kul records the presence of a constant component. In the case of metal-. When the electrodes are in contact, the constant current component disappears and the actuator 10 indicates zero.

The transition time, during which the quasi-equilibrium state of the polarization potential is created, is about 10, therefore: the length of the direct half-wave exceeds no less than an order of magnitude. Ratio of durations of direct and inverse half-waves

there are 8 limits t 5-10 ,, and the ratio of the amplitudes of the currents i 5-10 i

1G

ka my 1.1-1.5 a.

The magnitude of the half-wave amplitude is

Registration of a metal contact improves the accuracy and reliability of detecting a contact, which allows obtaining high quality of the workpiece surface.

-ts

FIG. one

12

 yy: p7

(rig 2

fig.Z

Claims (1)

METHOD OF DETECTING ELECTRODES TO ELECTRODES IN ELECTROCHEMICAL PROCESSING, in which the technological current source is turned off, an alternating voltage from an auxiliary source is applied to the electrodes and the current passing through the interelectrode gap from the indicated source or voltage across the interelectrode gap is measured, characterized in that, for the purpose improve the accuracy of touch fixation by isolating the signal of the metal contact of the electrodes, an alternating voltage is formed from a sequence of alternating bipolar x pulses, in which the pulses of one polarity have the same proportions as the increased amplitude and reduced duration with respect to the pulses of the other polarity, and touch is determined by the fact that there is no constant component of the current or voltage of the auxiliary source. yu with words about m sl>