SU738817A1 - Method of extremal control - Google Patents

Description

I

This invention relates to electrophysical methods for processing materials; and, in particular, concerns the method of extreme control of the working parameters of the EDM process.

The known method of extreme regulation of the interelectrode gap during electro-erosive processing.

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The automatic search for maximum performance by this method is based on calculating the difference of two measurements of the number of pulses moving an electrode tool over two equal time intervals. In this case, the readings obtained for the second are subtracted from the accumulated for the first interval of readings, and the adjustment of the machine setting, for example, the interelectrode gap, is carried out according to the sign of the obtained difference 1.

The disadvantage of this method is that, by the sign of the difference obtained, one can only determine the sign of the next correction correction pro (Interwire. The magnitude of the correction remains unknown.

A small correction value leads to an increase in the search time for the maximum; performance, and a large amount of correction - to the oscillations of the electrode-tool and, as a consequence of this, to a short circuit between the electrode-tool and the product.

The aim of the invention is to reduce the search time for the maximum performance of the EDM machine, by determining the sign and the absolute value of the correction of the interelectrode gap.

This goal is achieved by the fact that in the well-known method instead of two, periodically speaking, measurements of the number of imputations,. moving the electrode tool in two

15 equal, periodically repeating time interval, producing a single measurement of three values of the speed of movement of the electrotool with three values of the interelectrode gap, simultaneously determine these

Claims (1)

The 20 values are, using these values, the proportionality coefficient, at which the interelectrode gap value corresponds to the maximum performance. 3 n |) 6ixecca, is found in one step, and the difference between the last measured values determines the sign and the absolute value of the interproject-gap correction. The known erosion rate V and inter-electrode strip Z is described by the equation of the second-order curve on the plane. This dependence can be presented analytically as follows:, VV - k (Z - Z), (1) where V is the maximum value of the erosion rate at a given processing mode Z is the interelectrode gap value corresponding to the maximum value flaxity; k - the coefficient of proponality. For some value of the interelectronic gap Zj, it is necessary to carry out the emission of the speed of movement of the electrode tool Vi. By changing Zi to the well AZ, the inter-electrode gap is led to the value of Zj and the speed of the Scheni variable of the electrode-tool Vj is measured. By a similar change in Zj by the value AZ, the value of the interval Za is set and the measurement of the speed of movement of the USE Vi, Vj and Vj is made. The first differences can be determined :, AV, V2-Vi n, AV2 V3-V2, and then the second difference: DUg - AV, OZ - 2 Vj + UG. ;.: l To transform the value by substituting the values of Y, Y, UZ according to dependence (1), we get: - (Z3-Z.) D Y from here: 2 (Uz-2Y ;, - K (,) It is known that Z, corresponding to the maximum performance mode and the Y – K (ZZ) dependency, decides with: Z Zj + 2oi, K For a ”, j2, the value of Z can be determined after measuring Zj, Zj, Zj immediately if the interelectrode gap is changed by : 24 - 2 At the same time, a as follows from (3) 2 Z. That is, knowing A À g Vs, UZ, Zs, we can define, -blN divide Z. Since the value of V is in a constant known relation ( 1) from Z, then, zn, zn Its absolute value and sign can be maintained at 2 2 7 4. S In Fig. 1, a block diagram of the device that implements the proposed method is given; Fig. 2 is a plot of the movement speed from the interelectrode gap; Fig. 3 is a diagram of the change spacing in time. The method can be implemented using a device consisting of a reversible counter of displacements I, devices 2-4 of potential-pulse coincidence of signals, software device 5, computing device 6, generator 7 of rectangular impulses All of the voltage transducers are code 8, 9, the switch 10, the pinch motor 11, the measuring device 12, the electrode tool 13, the electrode part 14. In FIG. 2 shows the speeds of movement to points 15, 16, 17 and the corresponding gap values by points 18, 19, 20, as well as the optimum gap 21 at maximum speed (point 22). The method is carried out as follows. The pulse of the electrode electrode 13. At time intervals, periodically set by the programmer 5, through the potential-impulse coincidence circuit 2 is fed to the input of the computing device $. At the same time, the average value of the voltage between the electrodes 13, 14, characterizing the interelectrode gap, is measured by the device 12 and converted into a code by the device 9 are entered into the lowering unit 6 at a time interval. The coincidence determined by the programmer 5 through the potential-pulse matching circuit 4. The change in the interelectrode gap 13, 14 during the adjustments is made by Pbdk input to the switch 10 of the stepper motor P of the generator 7 of the square pulses. The connection is carried out through a potential-pulsed coincidence circuit 3, controlled by the programmer 5. The voltage between the electrodes 13, 14 is measured and the value of the interelectrode gap 18 is determined by the linear dependence of the voltage Y on the magnitude of the electrode gap Z Y 3 10 Z then, by the number of pulses of movement of the electrotool over a fixed time interval At, the erosion rate 15 corresponding to the interelectrode gap 18 is determined. Then, the voltage between the electrodes 13, 14 is changed by Y A Y, which corresponds to a change in the interelectrode gap 18 by the value of D Z to a value of 19 and in the number of impulses of movement of the electrode-in5. . for the time interval A t, the erosion rate 16 corresponding to the interelectronic gap 19 is determined. Thereafter, the voltage AND again between the electrodes 13, 14 is changed by -LV, which corresponds to the change in the interelectrode gap 19 by D 20 and by the number of pulses of movement of the electrode tool over the time interval D t, the erosion rate 17 corresponding to the interelectrode gap 20 is determined. By the values of erosion rates 15.16, 17 and the corresponding values of the interelectrode gaps 18, 19, 20 Computing device 6 by expression A determines the value of a — the coefficient of correction of the interelectrode gap 20, and by the values of the erosion rates 16, 17, the corresponding values of the interelectrode ind., 19, 20, and the coefficient a, by expression (4), em is greater than the correction of the interelectrode gap 20 to a value of 21, corresponding to the maximum performance of the EDM process 22. -1 The amount of correction of the interelectrode strip 13, 14 is converted into a unitary code by the device 8, is input to the switch Ator 10 and further is worked out by a scapular motor 11. The established interelectrode gap value is optimal. The use of this method reduces the search time for the optimal feed rate and the optimal interelectrode gap, which leads to an increase in the productivity of the process. Claims. The method of extreme regulation of the electrical meters erosion process, consisting in measuring the number of pulses moving an electrode tool at equal intervals of time, determining the difference between these measurements and correcting the machine setting by the sign of the difference obtained, in order to improve the performance of the process, measure the number the impulses of the transference; the electrodes of the tool electrode produce the values of the interelectrode gap, determine the absolute value of the difference of these values and the correction value poured proportional to this difference. Sources of information taken into account during the examination 1. USSR author's certificate No. 243112, cl. B 23 P 1/14, 1968. GU