SU1450941A1 - Method of electric machining of current-conducting materials - Google Patents

Abstract

The invention relates to electrophysical processing methods and can be used for electrocontact processing. The purpose of the invention, the NIN, is an increase in the productivity and quality of treatment due to the intensification of the melt emission at unit discharge. The imposition of an additional impulse transverse field is carried out with a frequency lying within the frequency of the operating pulses. The determination of the moment of application of a magnetic field to the erosion gap is made by the signal of the current differentiator at the moment when the current of each working pulse begins to fall and is kept for a time until the current increment is negative. 2 Il.

Description

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The invention-te relates to electrophysical methods of processing current-carrying materials and can be used for electroerosive, for example electrocontact, processing of metals.

The purpose of the invention is noBbraieiffle performance and improved surface finish.

Fig. 1 is a block diagram of a device for implementing the method; Fig. 2 is a schematic of the device for performing the electrocontact cutting operation.

The device contains a power source 1 of an erosion gap 2, a sensor 3 of the force of a working current. differentiator 4, shaper 5 pulses of the pitcher of the coil of the solenoid 6, located on the magnetic conduit 7.

The workpiece 8 and the disk electrode-tool 9 are connected via brush devices and, the current leads to the power source of the erosion gap 2 consisting of the transformer Yu and the rectifier 11. In turn, the shunt 12 is turned on in the power supply circuit of the erosion gap 2. The shunt is differentiated by means of a differentiating circuit 13 and is applied to the control electrodes of the thyristors 14 of the impregnator 5. This is a transformer 15 and a controlled rectifier consisting of valves 16 and thyristors 14. The load of the pulse shaper is a coil 17 of the solenoid wound on the magnetic circuit 18. A diode serves to protect the thyristor control circuit from the reverse polarity. 19. The resistors 20 serve to match the thyristor control current to the output of the differentiator 13. As can be seen from the diagram, the thyristors 14 are in the open state only during periods when the polarity of the signal from the differential output torus corresponds to the one shown in the diagram. The rest of the time thyristors are closed, and the coil 17 is de-energized.

The method is as follows.

in a way.

During processing, the signal is proportional to the strength of the operating current from the sensor 3 operating current strength, is fed to the input of the differentiator 4

At the times when the current in the working pulse increases, the signal from the differentiator to the input of the pulse shaper has a positive value, and the voltage at the top of the pulse shaper is not available, the solenoid coil is de-energized. At the time when the current in the working discharge begins to decrease, the signal at the output of the differentiator becomes negative, and at the output of the pulse shaper a voltage of 5 is applied, and the magnetizing current passes through the solenoid coil. An impulse of additional transverse magnetic field is superimposed on the aerosion 0 gap. At the end of the pulse

operating current, the signal from the operating current sensor becomes zero, the pulse driver de-energizes the solenoid coil. 5 Thus, the imposition of an additional transverse magnetic field on the erosion gap is made only at the moments when the operating current decreases, i.e. when its first pro 30 derivative is negative.

The technical and economic efficiency of the method consists in increasing the productivity and ul: improving the quality of the treated surface, which is achieved by reducing the melt ejection from the well by an external pulsed transverse magnetic field, which is additionally imposed on the interelectrode gap at 40 when the derivative of the current of each working pulse has a negative value.

Claims (1)

Invention Formula The method of electrical treatment of current-carrying materials with the imposition of an additional pulsed transverse magnetic field on the erosion gap with a frequency lying within the frequency of operating current pulses, characterized in that, in order to improve the performance and quality of processing by increasing the ejection of the melt from the well, magnetic field, the imposition of this field on the erosion gap is produced by the signal of the current differentiator at the time of the beginning of the current decline 31450941 each working impulse and keep it constant for a time-negative value, NIr while the increment of forces negative meaning, NIr until the current increment has A and F f c 5L ZX to to i l