SU1301597A1 - Method of electro-abrasion grinding - Google Patents

Abstract

The invention relates to electrophysical and electrochemical treatment systems, in particular, with electro abrasive grinding methods. The purpose of the invention is to increase the processing accuracy by eliminating uneven removal of material in the initial stages of the processing process. The method contains two transitions. At the first transition, the voltage corresponding to the passivation voltage of the treated surface is set, and the amplitude of low-frequency current pulsations caused by the presence of untreated zones covered with a non-conducting film on the surface of the workpiece is monitored. After these pulsations disappear, the voltage is increased to the transassivation voltage of the material being processed. This ensures uniform compression of the remaining allowance. 1 il. i 00 about ate with 1

Description

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11301597

The invention relates to electrophysical and electrochemical processing methods, in particular to electroabrasive grinding.

The purpose of the invention is to improve the machining accuracy by eliminating unevenness in removing the allowance at the initial stage of machining when the surface of the part is covered with an oxide film.

The drawing shows a diagram of the device for implementing the proposed method.,

The device contains a rotating spindle 1 with a chuck 2 into which the workpiece 3 is being installed, a spindle 4 for fixing an electrode tool 5, a process voltage source 6 connected to spindle m 1 and 4, a current sensor 7, a low-pass filter 8, 20 to sensor 7, divider 9 connected to sensor 7 and filter 8, task device 10, comparison device 11 connected by inputs to divider 9 and dividing device 10, and output to control device 12 whose output is connected to control input of source 6 tehnol ohic tension

In addition, the device has a mechanism 13 transverse feed.

The method is implemented as follows.

The treatment is started at a technological voltage equal to the passivation voltage of the material being processed. This voltage produces a source 6 when a switch-on signal is supplied from control device 12.

When the diamond electrode tool 5 is inserted into the part 3 during the working stroke of the drive 13 of the transverse feed and rotation of the spindles 1 and 4 by a change in the process pressure, the abrasive cleaning is performed either for the second transition, only some surface areas differing in that 3. Thus, in order to increase the accuracy of the zone, the processing of the tread, alternately with the rotation frequency, begins at the passivation stress, the parts fall as a cleaned part of the processed material, while

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There is no intensive removal of the allowance from the bare zones with the formation of macroscopic irregularities on the surface being processed.

Low-frequency oscillations of the current is fixed by the current sensor 7. Filter 8 extracts the average current value.

The inputs of the divider 9 receive two signals: the current reflecting nature of the pulsations from the sensor 7, and the average from the output of the filter 8. The divider 9 generates a signal for the ratio of the amplitude of the pulsations to the average value of the current.

The deviation signal in the comparison device 11 is compared with the signal of the task device 10. The result of the comparison is fed to the control device 12.

As the sections of the part 3 covered with a pass} with a spreading film are cleaned, the level of current pulsations decreases. After these areas disappear completely, the pulsations disappear. This registers the comparator device 11 and a signal is sent to the input of the control device 12, which causes the voltage to switch to a level corresponding to the voltage of the processed material. At this point, all areas of the surface to be treated are under the same conditions and removal, the stock is performed uniformly.

The machining accuracy is high, including when removing small allowances at the finishing technological operations.

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formula of invention

Electroabrasive grinding method, performed in two transitions with

ki, and areas covered with a passivating film. This causes current oscillations at frequencies that are multiples of the frequency of rotation of spindle 1.

Since the voltage between the part 3 and the electrode tool 5 is set at the voltage level

five

0

five

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five

There is no intensive removal of the allowance from the bare zones with the formation of macroscopic irregularities on the surface being processed.

Low-frequency oscillations of the current is fixed by the current sensor 7. Filter 8 extracts the average current value.

The inputs of the divider 9 receive two signals: the current reflecting nature of the pulsations from the sensor 7, and the average from the output of the filter 8. The divider 9 generates a signal for the ratio of the amplitude of the pulsations to the average value of the current.

The deviation signal in the comparison device 11 is compared with the signal of the task device 10. The result of the comparison is fed to the control device 12.

As the sections of the part 3 covered with a pass} with a spreading film are cleaned, the level of current pulsations decreases. After these areas disappear completely, the pulsations disappear. This registers the comparator device 11 and a signal is sent to the input of the control device 12, which causes the voltage to switch to a level corresponding to the voltage of the processed material. At this point, all areas of the surface to be treated are under the same conditions and removal, the stock is performed uniformly.

The machining accuracy is high, including when removing small allowances at the finishing technological operations.

a change in the process pressure for the execution of the second transition, characterized in that, in order to increase the accuracy, the processing begins at passivation voltages of the material being processed,

40 f

formula of invention

Electroabrasive grinding method, performed in two transitions with

a change in the process pressure for the execution of the second transition, characterized in that, in order to increase the accuracy, the processing is started at the passivation stresses of the material being processed,

50 controls the ratio of low-frequency pulsations of the process current to its average value and, as the value of this ratio decreases to a predetermined value, increases the technological voltage up to the trans-passivation voltage of the material being processed.

Editor A. Kozoriz

Compiled by R. Melder

Tehred A. Kravchuk Proofreader d.Obruchar

Order 1181/14 Circulation 976 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

Claims (1)

Claim The method of electro-abrasive grinding, carried out in two transitions with a change in the technological voltage to perform the second transition, characterized in that, in order to increase accuracy, the treatment is started at the passivation stresses of the processed material, while the ratio of low-frequency ripples of the technological current to its average value is controlled and reducing the value of this ratio to a predetermined value increases the process voltage to the voltage of the passivation of the processed material.