SU1357161A1 - Method of electrochemical machining of internal surfaces of parts of tube type - Google Patents

Abstract

The invention can be used for the electrochemical treatment of internal surfaces of pipes. The purpose of the invention is to increase the accuracy and quality of processing by compensating for changes in the conductivity of the electrolyte along the length of its flow. Screw grooves are made on the working surface of the electrode to create an additional electrolyte pumping path. The grooves are made with a monotonically variable depth determined from the condition that the electrical conductivity is kept constant as a function of temperature change and gas saturation, and the electrolyte is fed into the gap between the electrode and the workpiece on the side of the greatest groove depth. This allows you to control the electrolyte parameters along the length of the hole being machined and thereby increase the machining accuracy. 3 il. (L SO eaten

Description

The invention relates to the field of electrochemical machining and can be used in mechanical engineering for machining parts such as pipes or deep holes.

The purpose of the invention is to improve the accuracy and quality of processing by controlling the parameters of the electrolyte along the length of the hole being processed, the pressure parameters of the electrolyte inside the flow, its specific gas saturation, and the flow rate being used as control parameters.

Fig, 1 shows the electrode-tool with the workpiece, a cross-section; in fig. 2 - scan the side surface of the electrode tool; in fig. 3 - section A-A in FIG. 2.

The electrode tool for machining the hole in the workpiece 1 consists of a conductive body 2, in which helical grooves 3 are made with a variable cross-sectional area. The grooves are covered with cathode strips 4, in which slots 5 are cut for supplying electrolyte to MEZ 6. To center the tool electrode in the hole in the housing 2, insulating shoulders 7 are inserted.

The method is carried out as follows.

The electrode tool is inserted into the hole to be machined and a rotary motion is transmitted to it. the direction indicated by the arrow, and the direction of rotation is chosen in accordance with the direction of twist of the screw grooves. A potential difference is superimposed on the conductive housing 2 and the workpiece 1. An electrolyte is pumped through the screw grooves 3 and through the slots 5 in the cathode strips 4 enters the MEZ 6. The electrolyte pressure along the length of the MEZ changes depending on the change in the depth of the groove 3 The sludge and gaseous electrolyte exits through the opposite end of the hole.

Example. Let the depth of the screw groove at the end C be equal to B, and the depth at the end B be equal to h (Fig. 3). Then, with a constant groove width, the relative change in the cross-sectional area of the screw groove from the end C to the end B is equal to the ratio H: h. Let the pressure in the electrolyte flow at the end C of the screw groove P 1.5 MPa,

The cross section is the equalization of the area of the transverse or screw groove from the end C oct B, the speed of the electrolyte at the end C m / s.

From the flow continuity equation we have:

V

,

S

at

where s (.

8 „V, then V

the cross-sectional area of the groove at the end C; the cross-sectional area of the groove at the end B; electrolyte flow rate at end B.

V and; V and ch

40 m / s.

0

The Bernoulli equation in this case has the form:

cTTZO 72

+ R.

fZi +

2

fVf

p; 4FC 2

6

0

five

0

five

where j) is the electrolyte density;

P is the pressure in the electrolyte flow at the end B.

Substituting the corresponding values into the Bernoulli equation, we obtain 9 MPa.

When the cross-sectional area was changed by a factor of 2, the change in electrolyte pressure in the ORE was obtained by 40% without taking into account friction losses against the channel walls.

Thus, when processing by the proposed method, it is possible, by varying the pressure change in the MEP, to control the degree of gas-filling of the electrolyte over the cross sections, which causes a change in its specific conductivity. Due to this, a correction of hole shape errors can be obtained and the quality of processing can be increased.

45 Formula of invention

0

five

The method of electrochemical treatment of internal surfaces of parts such as pipes, in which electrolyte is pumped through the gap between the surfaces of the pipe and the electrode-tool inserted into it, in the body of which screw grooves are made to create an additional electrolyte pumping path, characterized in that in order to increase the accuracy and the quality of processing, by compensating for the change in the electrical conductivity of the electrolyte along the length of its pumping path, the grooves in the tool electrode are made with a monotonically varying depth, my condition

maintaining electrical conductivity of the groove depth

D

13571614

as a function of temperature change and gas saturation, and the electrolyte is fed into the gap from the side

Vus. one

(Reg. 5

Claims (1)

Claim A method of electrochemical processing of the inner surfaces of parts such as pipes, in which the electrolyte is pumped through the gap between the surfaces of the pipe and the inserted electrode-tool, in the body of which are made screw grooves to create an additional path for pumping the electrolyte, characterized in that, in order to increase accuracy and processing quality, by compensating for changes in the electrical conductivity of the electrolyte along the length of its pumping path3, the grooves in the electrode-tool are performed with a monotonously varying depth, determined from the conservation of electrical conductivity of constant changes in the temperature and gas saturation function, and the electrolyte is fed into the gap by the greatest depth of the grooves.