SU1646729A1 - Electrical machining method - Google Patents

Abstract

The invention relates to mechanical engineering and can be used in the finishing processing of plastic conductive materials. The purpose of the invention is to improve the quality and productivity of processing by eliminating wire defects and reducing the number of tools used. The rotating brush electrode is a sleeve 1. on which a wire 2 is cantilevered, placed in a tube 3 made of elastic dielectric. The tube 3 is made shorter than the wire and has the ability to slide relative to it. Processing at the rough stage is based on the erosion-chemical-mechanical removal of metal. The rotation frequency is set so that the tube does not touch the treated surface 4. Then the brush is retracted until the discharges are eliminated and the rotation frequency is increased to the value at which the tube 3 lengthens to the contact with surface 4, and thus the finishing process is performed current strength. 5 il. (L S o -N o th H)

Description

Fy

The invention relates to mechanical engineering and can be used in the final processing of plastic conductive materials.

The purpose of the invention is to improve the quality and productivity of processing by eliminating wire defects and reducing the number of tools used.

Figure 1 presents a diagram of the process of roughing the electrode-brush; in fig. 2 is a section A-A in FIG. one; in fig. 3 - the brush electrode is retracted from the surface to be treated; in fig. 4 - finishing scheme; in fig. 5 is a section BB in FIG. four.

The method is carried out as follows.

The brush electrode is a sleeve 1 on which the wire 2 is cantilevered, placed in the tube 3 of an elastic dielectric material. The tube 3 is fixed on the sleeve 1 and has the possibility of free sliding relative to the wire 2. The treatment is carried out in two stages. At the first stage, roughing, processing is carried out with a clamp of 0.8-1.2 mm. allowing the accelerated removal of metal from the treated surface 4. At this stage, the treatment is based on the erosion-chemical and mechanical removal of metal. The dielectric tube is shorter than the wire and does not touch the surface to be machined; the rotational frequency of the seam is set such that at the first stage the tube does not touch the surface to be machined. In the second stage, the brush electrode is retracted from surface 4 to eliminate discharges. The absence of bits is recorded via video or instrument. The rotational speed is then increased to on. Under the action of centrifugal forces, the elastic tube 3 lengthens (C) until it touches the treated surface 4, and thus the finishing process is carried out with a constant amperage.

The elongation of the elastic tube depending on the frequency of rotation is determined by the dependence

. r0COS € G (1- $).

Ґ cos bЈf U)

sin vETЈ vЈFcos vEFu

-r0.

ly is the elongation of the electric tube; r0 is the radius of the brush hub;

n-b ° L

a k T

where PO is the density of the elastic tube in a non-deformable state;

k is the coefficient of linear elasticity;

a) is the frequency of rotation of the brush electrode; LO is the length of the elastic tube in a non-deformable state;

Ј is the coordinate of the non-deformable dielectric tube.

PRI me R. The device is a brush of 0250 mm, the radius of the brush hub is 12 mm, copper wire is 00.6 mm, the width of the brush is 15 mm. external diameter

dielectric tube 0.74-0.76 mm, internal diameter 0.7 mm; packing density 0.53 (tubes per 1 mm2). The treatment is carried out in two stages, at a constant current of 100 A and a voltage of 8 V, first with

clamping 0.8-1.2 mm and a rotational speed of 1200 rpm, the metal was removed, then the brush was retracted from the surface to be processed, the circumferential speed increased to 1500 rpm, the dielectric tubes were lengthened until they touched the parts and then the surface was attained A, 1NZ B. When roughing (1st stage) the submission of parts M / min, when finishing (2nd stage) M / min. The composition of the electrolyte used: 15-20% №e2CO3 + 20% oil Indusgrienoe 20. The temperature of the electrolyte is 20-26 ° С.

The device uses nylon

tube. Density p 1.2 g / cm (determined experimentally). The coefficient of linear elasticity, 87 10.

The use of the method of metal finishing by the brush electrode allows to obtain a surface without local defects from the effect of the wire, reducing the number of tools used.

Claims (1)

Invention Formula A method of electromechanical processing carried out by a rotating metal bristle brush electrode, which is characterized in that, in order to improve the quality and productivity of the finishing machining of plastic conductive materials, a brush electrode is taken, the bristle wires of which are placed in tubes of elastic dielectric material and come out of them, the treatment is first led the ends of the tubes coming out of the tubes, then the brush is retracted from the part until the discharges are eliminated and the rotation frequency is increased to a value determined by the dependence X - roCOS C1-0 Ј) + cos (VcTu) . stn VETЈ ЈTcos Vcf Lo Ј is the coordinate of the undeformable tube; „Pa (I   T where X is the elongation of the dielectric tube until it touches the surface being treated where where l is the density of the tube in the non-deformed state; r0 is the radius of the brush hub; K is the coefficient of linear elasticity; LO is the length of the elastic tube in nedefor- y- the frequency of rotation of the electrode-brush, abnormal condition; FIG. I FiaZ Figm 5-5 FIG. five