SU623274A1 - Method of electric supply of gas-discharge thermal plant for workpiece treatment - Google Patents

Description

one

The invention of the ognosigs to the execrocaster and can be used in the technological processes of machining parts produced with the help of a precision current discharge.

Methods are known for ejecting gas-discharge thermal installations, which allow the south to regulate a HIGH-CURRENT glow discharge by reducing the supply voltage.

Incorporate into the circuit a discharge of additional resistance when an arc discharge occurs flj. The application of these methods is possible with the help of switching bodies, connected in series or in parallel with the discharge gap.

A known method of powering a gas-discharge thermal unit designed for parts machining, which consists in supplying electrical power pulses to the gas discharge interval with the time interval between the pulses, deactivating the discharge gap time.

Moreover, depending on the temperature of the machined parts, the duration of each of the supply pulses is adjusted and when the current exceeds a certain amount of time, the source of the pulses is turned off.

However, this method, due to the inevitable inertia of the current sensor, power source and other episodes, does not allow shutting off the power source quickly enough, which leads to incomplete elimination of undesirable effects (damage to the surface of the workpiece, overload of the power source, etc.) with the transition of a glow discharge to an arc.

The aim of the invention is the elimination of the harmful effects of the arc discharge on the workpieces arising during the transition of the glow discharge to the arc and the improvement of the quality of processing.

Claims (2)

The goal is achieved by maintaining the energy of each of the power pulses to maintain a constant and lesser energy of damage to the parts. The damage energy level of the degapay is determined by the type of energy processed by the level of the supplied energy and other installation parameters and is within (1, MG, where the nominal voltage is supplied, Fig. 1 shows a diagram of the device implementing the proposed method, Fig. 2 - temporary device operation diagrams. The device contains a source of constant voltage 1, a vacuum chamber 2, inside of which there is a workpiece 3, connected to the minus of a source of constant voltage 1, thyristors 4-7 and a dosing condensate 8. Assume that thyristors 4 and 7 are turned on at time point –fc.r. The supply voltage IJf through a capacitor 8 is applied to the discharge gap, and a glowing discharge occurs between the part and the chamber walls. As the capacitor charges, the discharge current decreases to zero and the thyristors 4 and 7. At time I, the thyristors 5 and b open, and a voltage pulse is discharged on the discharge gap with an amplitude equal to 2111. Then the process repeats. Thus, pulses are formed on the load, the shape of which is determined by the parameters of the circuit and the nature of the discharge. If at the moment of time ... an arc discharge arises, then a fast recharging of 1 capacitor will occur, with the result that the energy in the impulse will remain constant and approximately equal to (C the capacity of the metered capacitor). The shaded portion of the pulse in FIG. 2 corresponds to the arc discharge. The arc-off time in this case can be made quite short (on the order of 2ie, where the recovery time of the thyristors used in the circuit). The average energy of the load can be adjusted by changing the frequency of recharging the capacitor or the magnitude of the supply voltage, or the capacitance of the capacitor C. The proposed method makes it possible to completely eliminate the harmful effects of arc discharge on the workpieces and improves the reliability of the power sources in gas discharge installations using heating high-current glow discharge. This allows to improve the quality of processing, reduce losses from scrap and reduce costs in the operation of these wok. DETAILED DESCRIPTION OF THE INVENTION A method for supplying electrical parts to a gas-discharge thermal unit for processing parts, in which electrical power pulses are applied. with the time interval between pulses, longer deionization time of the discharge gap and changing the parameters of each of the pulses, distinguishing with the fact that, in order to improve the quality of machining of parts, the energy of each pulse is kept constant and less energy of damage of parts. into account in the examination: 1.Patent of Germany K 1275229, cl. 21 H - 16/60, 1969. 2. The UK patent number 1255321, cl. From 7th, 1971. Vuz.1 t FIG. 2