RU2401725C2 - Method of electrochemical dimensional treatment of parts and device to this end - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to electrochemical treatment of metals and alloys. Articles from sheet materials are treated by at least two oscillating tools-cathodes and by feeding process voltage pulses synchronised with cathodes oscillation. Complete profile of articles is produced during two stages. During the first stage, one side of anode-article billet is formed. Then after turning anode-billet through 180° about turning axis perpendicular to electrolyte feed axis, second side is formed. At the same time at least one pair of anodes-billets is subjected to treatment, each pair having split line located in one plane. Said pairs are located on both sides of axis of symmetry passing through axis of turning. Note here that treatment during first stage is performed till split line of anodes-billets in each pair. Note also that treatment is performed with electrolyte feed rate of 10-15 m/s process voltage amplitude of 30-40 V that allows pulse duration of said voltage of 0.2-0.3 s. Proposed device comprises cathode-tools, electrode support plate for fixation of cathodes-tools, locator plate for anode-billet with process allowances and process tooling providing feed of electrolyte into treatment zone via electrolyte feed channels and anode dissolution product discharge line, and accumulating bath. Cathodes-tools are grouped in at least one pair of parallel cathodes-tools on both sides of vertical plane of symmetry and arranged in pairs with mirror mapping of work surfaces facing each other with symmetry reversed through 180°.

EFFECT: possibility to treat simultaneously several anodes-billets, simplified process and equipment, higher accuracy of treatment.

9 cl, 11 dwg

Description

The invention relates to the field of electrochemical dimensional processing of metals and alloys, mainly products from sheet material, and can be used, for example, for the manufacture of aircraft blades.

There is a method of electrochemical treatment of a turbine blade simultaneously with two shaping surfaces of the anodes-blanks of the turbine blade moving towards one another with cathode tools (Baysupov IA Electrochemical processing of metals. M.: Higher School, 1988, 117-118 pp.).

The disadvantage of this method is the instability of the processing parameters, from which errors appear in the accuracy of processing, in addition, the method is characterized by low productivity due to the impossibility of simultaneously processing several anode blanks of a turbine blade.

A known method of processing in a pulsed-cyclic mode, in which during the processing periodically change the direction of supply of the electrolyte into the interelectrode gap, and the change in the direction of supply of the electrolyte is carried out by rotating the anode-workpiece together with the cathode-tool around an axis perpendicular to the direction of supply of electrolyte. (Patent RU No. 2263010, B23H 3/00, publ. 2005.10.27).

The disadvantage of this method is the limitation of technological capabilities and processing accuracy, as well as the inability to process several anodes-blanks of the product.

Among the known analogues of the claimed technical solution (prototype), there can be a method of electrochemical dimensional processing of a product with two vibrating tool cathodes with a supply of process voltage pulses synchronized with tool cathode vibrations, in which a complete product profile is obtained in series in two stages, first one side of the anode is formed -workings, and then after turning 180 ° around an axis perpendicular to the direction of electrolyte supply, the second side of the anode is formed application (RU №2305614 C2, publ. 2007.09.10).

A device for implementing this method includes two tool cathodes, an interelectrode gap between the tool cathodes and a workpiece anode having a parallelepiped shape with technological allowances on the end sides, an electrode plate for attaching tool cathodes, a base plate for the workpiece anode, and technological equipment that provides the supply of electrolyte to the zone of electrochemical processing, storage bath.

This known method and device for its implementation have disadvantages: firstly, the complexity of the device for attaching cathodes-tools, leading to a loss of time; secondly, because removable cathodes-tools are used in the known device, there is a probability of errors in the cathode-tool base when it is changed, as well as unreliability of the anode-workpiece fixing contacts, which reduces the accuracy of electrochemical shaping; thirdly, low productivity.

The technical result of the claimed invention is the ability to simultaneously process several anode blanks while simplifying the process technology and equipment design and improving the accuracy of processing the profile part of the anode blank of the product.

In accordance with the invention, the stated technical problem is achieved by the fact that in the claimed method of electrochemical dimensional processing of products from sheet material, fundamentally different and simpler, compared with the prototype, technical solutions are used regarding the design of cathodes-tools, sub-electrode plate, base plate, technological equipment based on the correct basing of anode blanks, as well as the choice of processing parameters (tool oscillation frequency, speed under chi electrolyte magnitude voltage amplitude value of the technological cycle and pulse duration).

The electrochemical dimensional processing of sheet metal products is carried out at least by two vibrating tool cathodes with a supply of process voltage pulses synchronized with the tool cathode vibrations, in which a complete product profile is obtained in two stages in series, at the first stage one side of the billet anode is formed products, and then after turning the anode-workpiece 180 ° around the axis of rotation perpendicular to the direction of supply of the electrolyte, form its second side. At least one pair of billet anodes is subjected to processing at the same time, each of which has a split line lying on one plane and located on both sides of the vertical plane of symmetry passing through the axis of rotation, while processing at the first stage is carried out to the line connector anodes-blanks in each pair, and the processing is carried out at an electrolyte feed rate of 10-15 m / s and a magnitude of the amplitude value of the process voltage of 30-40 V, providing a cycle time of pulses of the process voltage spacing 0.2-0.3 sec.

A device for electrochemical dimensional processing of products from sheet material contains cathodes-tools, a sub-electrode plate for attaching cathodes-tools, a base plate for the anode-blank with technological allowances and technological equipment that provides the supply of electrolyte to the treatment zone through the channels for supplying electrolyte and the output of anode dissolution products , storage bath. Tool cathodes are grouped in at least one pair of parallel tool cathodes located on both sides of the vertical plane of symmetry and made in pairs, each with a mirror image of the profiles of the working surfaces facing each other with 180 ° symmetry inverted.

The tooling is equipped with at least one pair of longitudinal cavities with dimensions equal to the overall dimensions of the tool cathodes, an electrolyte feed channel into the interelectrode gap, and an anode dissolution product outlet channel located along the surface of the anode blank in the areas of technological allowances.

The base plate is made with overall dimensions designed to accommodate at least one pair of workpiece anodes on it and has base fingers to ensure that each workpiece anode is paired with respect to the tool cathodes.

The electrode plate is made with overall dimensions designed to accommodate at least one pair of tool cathodes on it, and is equipped with pins to base each tool cathode in pair relative to the longitudinal cavities of the tooling.

Preferably, the feed channel of the electrolyte was made in the area of the front end side of the anode blank in the form of a flow channel connected to the storage tank and an intermediate channel in communication with the flow channel in the operating mode. The outlet channel for the products of anodic dissolution is made in the form of a through longitudinal cavity formed in the area of the rear end side of the billet anode by the cathode-tool and the inner wall of the through cavity made with a size larger than the size of the cathode-tool.

It is desirable that the stepped cavities be dimensioned to ensure that the walls of the cathode-tool are mated to the walls of the cavity along a sliding fit H8 / h8 directed normal to the corresponding forming surfaces of the anode blanks.

The flow channel is made inside the cathode-tool, and the intermediate channel is formed by the cathode-tool that has entered the longitudinal cavity and the inner wall of the stage is provided on the lower side of the longitudinal cavity, while the intermediate channel is made with a width smaller than the width of the flow channel.

The longitudinal cavities are dimensioned so that the walls of the cathode-tool are mated to the walls of the cavity along a sliding fit H8 / h8 directed normal to the corresponding forming surfaces of the anode blanks.

The device is equipped with columns mounted on the sub-electrode plate to determine its position relative to the base plate.

The present invention is illustrated by one specific example of the method of electrochemical dimensional processing of one pair of blades for aircraft, which is not the only one, but clearly demonstrates the case of a specific application of this set of essential features in a particular object.

The invention is illustrated by drawings, which depict:

figure 1 is a schematic diagram of a device for electrochemical shaping of the surfaces of two blades, a longitudinal section;

figure 2 - view aa of figure 1, tooling conditionally removed;

figure 3 - tooling, top view;

figure 4 is a view aa of figure 3;

5 is an anode-blank of the blade;

6 is an anode blank, view A of FIG. 5;

Fig.7 is a sequence diagram of the operation of the machine EHKP-7M, the dependence of the washing and working clearances on the processing time;

Fig - a sequence diagram of the work of the machine EHKP-7M, the dependence of the pulse voltage on the duration of the pulse train;

Fig.9 is a variant of the product to be processed;

figure 10 - location of the anodes-blanks;

11 is a variant of the location of the anode blanks.

The device for electrochemical dimensional processing (Fig. 1) includes a sub-electrode plate 1, tooling 2, which provides an electrolyte supply, an anode-blank 3, a base plate 4.

At least one pair of vertically arranged tool cathodes 5 on both sides of the vertical plane of symmetry ZZ1, made with a mirror image of the working surface profiles, is mounted on a sub-electrode plate made in the form of a parallelepiped and connected to the negative pole of a power source (not shown) facing each other with 180 ° symmetry inverted.

The profile of one cathode-tool in a pair repeats the geometry of the upper surface 6 of the anode-workpiece, and the other - the lower surface 7 of the anode-workpiece (Fig.6).

The anode blank of sheet material has a longitudinal line of connector XX1 lying in the same plane (Fig. 6). Relative to the horizontal axis UU1 (figure 2), perpendicular to the direction of supply of the electrolyte and through which the vertical plane of symmetry ZZ1 passes, the anode-blank has a pair. The billet anodes located on both sides of the symmetry plane ZZ1 are oriented in such a way that when they are turned around the horizontal axis of the UI1, the treated surfaces are mirrored relative to the surfaces to be processed. The anode blank has landing holes 8 located on the technological allowances 9 on its end sides, providing an accurate basing of the anode blanks (figure 5). Each anode billet is fastened in pairs by technological allowances on the end sides with special clamps (not shown) or directly with technological equipment (as in the example).

In the body of each of the cathodes-instruments included in the pair, a flow channel 10 for electrolyte is made with a through hole 11 made in the side wall of the flow channel. The cathodes-tools are attached to the sub-electrode plate with screws 12 (Fig. 2) and are based on technological equipment with the help of pins 13, which fix them against displacement.

The base plate is fixed to the machine table 14 with bolts 15. Base fingers 16 are fixed to the base plate for interaction with the bore holes of the anode-workpiece in a sliding fit H8 / h7.

Technological equipment is equipped with at least one pair of longitudinal cavities 17 (Fig.3) for input of cathodes-tools. Each longitudinal cavity is made with dimensions equal to the dimensions of the cathode-tool and ensuring the coupling of the walls of the cathode-tool with the walls of the cavity along a sliding fit H8 / h8 directed along the normal to the corresponding forming surface of the anode-workpiece. In the tooling is also made from the front end side of the anode-billet intermediate channel 18.

The flow channel of each cathode-tool, communicating through a through hole with an intermediate channel, serves as a common channel for supplying the electrolyte to the interelectrode gap 19. From the side of the opposite end side of the workpiece anode, the walls of the through cavity are larger than the size of the cathode-tool, which creates the appearance of the wall of the channel that entered the cavity of the cathode-tool in the form of a through longitudinal cavity 20 for the output of anode dissolution products from the interelectrode gap zone (Fig. 2). The feed and exit channels are located along the split line of the anodes-blanks in the areas of technological allowances. An intermediate channel is formed (Fig. 4) by a cathode-tool entering the cavity and the inner wall of the stage 21 provided on the lower side of the longitudinal cavity, while the intermediate channel is made with a width smaller than the width of the flow channel. The height of the step is connected with the possibility of communication through the through hole of the flow channel of the cathode-tool with an intermediate cavity in the operating mode. To create a backpressure that provides the best hydrodynamic conditions for the passage of the electrolyte through the interelectrode gap, the cross-sectional area of the outlet channel of the anode dissolution products is slightly smaller than the cross-sectional area of the interelectrode gap. At the same time, it is necessary to ensure the maximum possible electrolyte consumption in the interelectrode gap, which can be achieved by eliminating electrolyte losses in front of the treatment zone.

Landing holes 22, coaxially made with the base fingers of the base plate, serve to base a pair of stepped cavities of technological equipment relative to a pair of cathode-tools.

The position of the electrode plate relative to the base plate is determined by the columns 23. In the electrode plate there is a storage bath 24, which communicates with the flow channels of the cathode-instruments.

By the example of two anodes-blanks of the blades of aircraft, the electrochemical processing was carried out on a modernized machine EHKP-7M with a vertical arrangement of cathodes-tools as follows.

A pair of workpiece anodes 3 is laid on the base plate 4 and the base fingers 16 by the connector line XX1, in our example, an anode plate is calculated to receive one pair of blades. The technological equipment 2 is mounted on the same base fingers by the mounting holes 22, which fastens the anode plate on the base plate in places of technological allowances for 9 blades. The cathodes-tools 5 are introduced into the longitudinal cavities 17 of the tooling, moving at the same speed. The position of the cathodes-tools before processing is set by touching them with the surface of the blades with subsequent retraction to the minimum allowable distance, i.e. the value of the washing gap Spr within 0.2-0.3 mm (Fig.7). In this position, the flow channel 10 of each cathode-tool through the through hole 11 communicates with the hole 18 for supplying the electrolyte into the interelectrode gap 19. The electrolyte is supplied under pressure at a speed of 10-15 m / s (Fig. 8), and through the flow channels 10 and intermediate channels 18, the electrolyte is pumped into the interelectrode gap along the connector line of the anode-blanks of the blades (in our example, the anode-plate).

The duty cycle is activated.

Based on the studies, the values of the main processing parameters are selected. In the process of the working cycle, the cathode-instruments make symmetrical oscillations with a frequency of 8-10 hertz every half period, touching the surface of the blade during the period of a voltage pause of the switching power supply. On the working cycle, the cathodes-tools are allocated to the working gap Sp in the range of 0.03-0.05 mm, and then to the washing gap. An impulse voltage is applied at a working gap with a duration of 4-5 seconds at an amplitude value of 30-40 V with a pulse train duration of 0.2-0.3 seconds. In the washing gap, through the outlet channel 20, anodic dissolution products are removed. Depending on the set cycle time, the processing process is repeated until the cathodes-tools reach the connector line XX1. The first stage of electrochemical processing is over.

At the second stage, the installation is turned off, the cathodes-tools are removed from the cavities of the technological equipment, the technological equipment and the anode plate are removed, they are turned 180 ° around the horizontal axis of УУ1. After the installation of technological equipment and the introduction of cathodes-tools in its cavity, the processing process is repeated. The formation of opposite surfaces of the blades occurs. The process ends when the complete profile of the machined surfaces of the blades is achieved.

At the end of the electrochemical shaping of both sides of the blades technological stocks 9 are removed mechanically. The blades are ready.

Figure 7 presents a variant of a complex product made of sheet material with a connector line lying in the same plane. Without changing the technology of the processing process, changing only the overall dimensions of the device, the invention allows you to simultaneously process several complex products, grouped in pairs with different options for their location in the device (Fig. 8 and 9).

The method and device for implementing the proposed method are characterized by a simplified process technology, the maximum accuracy of the base pair of the anode-workpiece, which positively affects the accuracy of the processing of the profile part of the anode-workpieces, reliability in operation.

Claims (9)

1. The method of electrochemical dimensional processing of products from sheet material with at least two vibrating tool cathodes with a supply of process voltage pulses synchronized with the oscillations of the tool cathodes, in which a complete product profile is obtained sequentially in two stages, at the first stage one side of the anode is formed - preparation of the product, and then after turning the anode-workpiece 180 ° around the rotation axis perpendicular to the direction of supply of the electrolyte, form its second side, characterized by At the same time, at least one pair of blank anodes is subjected to processing at the same time, each of which has a connector line lying in the same plane and located on both sides of the vertical plane of symmetry passing through the axis of rotation, while processing at the first stage they are carried out up to the anode-workpiece connector line in each pair, and the processing is carried out at an electrolyte feed rate of 10-15 m / s and a value of the amplitude value of the process voltage of 30-40 V, providing a cycle time of the process pulses about voltage 0.2-0.3 s. 2. Device for electrochemical dimensional processing of products from sheet material, containing cathodes-tools, a sub-electrode plate for attaching cathodes-tools, a base plate for the anode-blank with technological allowances and technological equipment that provides the supply of electrolyte to the processing zone through the channels for supplying electrolyte and exit products of anodic dissolution, storage bath, characterized in that the cathodes-tools are grouped in at least one pair of parallel-located cathodes-in trumentov on both sides of a vertical symmetry plane and formed in a pair with each mirror image profiles working surfaces facing to each other with an inverted by 180 ° symmetry. 3. The device according to claim 2, characterized in that the tooling is equipped with at least one pair of longitudinal cavities with dimensions equal to the overall dimensions of the tool cathodes, an electrolyte feed channel into the interelectrode gap, and an anode dissolution product exit channel located along the surface anode blanks in the areas of technological allowances. 4. The device according to claim 2, characterized in that the base plate is made with overall dimensions designed to accommodate at least one pair of billet anodes on it and has base fingers to ensure that each billet anode is paired with respect to the cathodes -tools. 5. The device according to claim 2, characterized in that the sub-electrode plate is made with overall dimensions designed to accommodate at least one pair of tool cathodes on it and equipped with pins to base each tool cathode in pair relative to the longitudinal cavities of the process snap. 6. The device according to claim 2, characterized in that the feed channel of the electrolyte is made in the area of the front end side of the anode blank in the form of a flow channel connected to the storage bath and an intermediate channel in communication with the flow channel in the operating mode, and the output channel of the anode dissolution products made in the form of a through longitudinal cavity formed in the area of the rear end side of the billet anode by the cathode-tool and the inner wall of the through cavity made with a size larger than the size of the cathode-tool. 7. The device according to claim 2, characterized in that the flow channel is made inside the cathode-tool, and the intermediate channel is formed by the cathode-tool included in the longitudinal cavity and the inner wall of the stage provided on the lower side of the longitudinal cavity, while the intermediate channel is made with a width smaller width of the flow channel. 8. The device according to claim 2, characterized in that the longitudinal cavities of the tooling for the input cathode-tools are made with dimensions that ensure the coupling of the walls of the cathode-tool with the walls of the cavity along a sliding fit H8 / h8 directed normal to the corresponding forming surfaces of the anodes- blanks. 9. The device according to claim 2, characterized in that it is equipped with columns mounted on the sub-electrode plate to determine its position relative to the base plate.

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