SU884930A1 - Method and apparatus for eliminating electrode short circuit at electric discharge machining - Google Patents

Description

The diameter of the wire was smaller.

The reduction of the diameter of the electrode wire is carried out by the EDM method using an additional electrode.

After the restoration of the normal process on the EDM gap formed by the product and the electrode-wire, the treatment of the latter in order to reduce its diameter is stopped. Feed controller included. The processing continues in the usual way. With the proposed method of eliminating short circuits, it is expedient at the time of electroerosive electrode wire-wire to accelerate the rewinding of the electrode in order to quickly bring its reduced participation: to the short-circuit zone. After elimination of the short circuit, the wire is rewound at a normal speed corresponding to the normal course of the treatment process.

The proposed method for the elimination of short-term shortcomings is most expedient to use with a non-reverse or with a limited reverse of the drive of the working feed of the machine.

The drawing shows a device for implementing the proposed method

In order to reliably eliminate short circuits and increase processing performance, the device is equipped with an additional electric drive using a screw pair connected to a table and controlling the movement of an additional electrode, a pulse generator, one of the outputs of which is connected to a non-profiled electrode, and the other through a switching element - to the additional electro-DU1 by the control device and the sensor of the state of the erosion gap, the input of which is connected to the product and the non-profiled electrode m, and the output - with the control device.

The device contains a non-profiled electrode-wire 1 rewired from coil 2 to coil 3, product 4 mounted on foot 5, moved by means of a screw gear 6 from electric motor 7 with an erosion gap regulator 8, a pulse generator 9 connected to one of the outputs To the electric wire 1, and to the product 4j, to the product 4j, sensor 1O of the erosion gap,

849304

connected to the electrode wire 1 and to the product 4, the control device 11 connected to the sensor 10, an additional electrode 12, connected by a screw pair 13 to an electric motor 14 controlled from the erosion gap controller 15, a pulse generator 16 connected one of the outputs to the electrode wire 1, and 10 through the switching element to the additional electrode. The control device 11 controls the switching elements 17 and 18. J

The device works as follows 15 times.

In the normal EDM process, the treatment of the products 4 is carried out with the aid of a pulse generator 9. The controller 8 maintains an optimal working gap between the product and the electrode wire, and the controller 15 between the same electrode wire and the additional electrode 12. Together with the product 4 installed on the table 5,

25 also moves the additional electrode 12 with a screw pair 13. The output of the generator 16 is disconnected from the additional electrode 12 when the noMomii switching element.

30 Sensor 10 measures the state of the interelectrode gap between product 4 and electrode-wire 1. In the absence of a short circuit, there is no signal to trigger the control device 11. The positions of the switching elements (contact block) 17 and 18 correspond to the positions indicated in the drawing.

Claims (2)

In the case of a short wedge of the product 4 and the electrode wire 1, the sensor 1O will issue a signal to the operation of the control device 11, which switches the switching elements 17 and 18. At this, the controller 8 is turned off, and the controller 15 continues to fit the interelectrode gap between an electrode wire and an additional electrode 12. For this same erosion gap, a generator 16 is operated. The GTolarity of the connection of the generator 16 is chosen such that it ensures predominant wear of the electrode wire 1 according to Compared with the wear of the additional electrode 12. In this case, the processing mode is chosen such that the wear of the wire relative to its nominal cross section in diameter is 10-30%. The wire section subjected to EDM processing in the process of its rewinding goes to the place of short circuit with the product. Since, at the point of contact, the electrode-wire came down with a reduced curl in the dia-; meter, the short circuit is eliminated, which is fixed by the sensor 10 which extracts the command to the device by turning it to perform the corresponding switching of elements 17 and 18. At the same time, the generator 16 is turned off and the regulator 8 is connected. The processing of the product 4 from the generator 9 is prolonged. The processing time of the part using the proposed device is shortened by 2 times. In addition, it becomes possible to process large-sized parts and eliminate the defects caused by undercuts and the breakdown of the gap when inserting the wire after frequent wire breaks with known processing methods. Claim 1. The method of eliminating short-circuiting of electrodes during electroerosive processing is continuously updated by a non-profiled electrode using an additional electrode, characterized in that, in order to increase processing performance, during moments of short 306 cations between the product and the non-profiled electrode, the latter is subjected to electrical erosion by means of electrical discharges between it and the additional electrode until the liquidation of the short circuit. 2. A device for electroerosive processing with a continuously renewed non-profiled electrode, containing a table for installing the product and electrically driving it, a bracket with a receiving and unwinding coil, a pulse generator, one of the outputs of which is connected to an unprinted electrode, and the other with the product, an additional electrode the controller, the controller of the erosion gap and the sensor of the state of the erosion promekutka, the input of which is connected to the product and the non-profiled electrode, and the output to the device and characterized in that it is equipped with a pulse generator, one of the outputs which is connected to an un-profiled electrode, and the other to an additional electrode, and the latter in turn is equipped with an electric displacement relative to the table and a gap regulator. Sources of information taken into account in the examination 1, USSR Author's Certificate No. 152789, cl; B 23 P 1 / OO, 1962.