RU200853U1 - Electrochemical plant - Google Patents

Abstract

The utility model relates to the field of technology for processing metals and other electrically conductive materials, in particular, to electrochemical installations (ECU). The ECU contains a connected electrode unit with a holder for the workpiece and with the possibility of placing in a container for electrolyte, an electrolyte preparation unit with a pump and a filter, a power supply unit with the ability to connect to an AC source, and a control and monitoring unit with means for displaying information about the technological process. The ECU is made portable, assembled in a sealed case with a lid, the holder of the workpiece is made magnetic with the possibility of removing reaction products from the processing zone, the electrolyte preparation unit is made in a sealed compartment of the case, includes an electrolyte flow meter, a heating element and an electrolyte conductivity sensor, a power supply is made with the ability to connect to an alternating current source with a voltage of 220 V through a current converter located in the case cover, and includes a duplicate DC source in the form of an electric power storage for autonomous power supply, and the control and monitoring unit is configured to install and control the electrolyte consumption, setting the temperature of the electrolyte, monitoring the electrical conductivity and pH of the electrolyte, setting the process duration, measuring and monitoring the voltage and current at the outlet of the installation, as well as the discharge parameters of the said energy storage device. EFFECT: expanding the technical and operational capabilities and characteristics of the installation by reducing its weight and size indicators, increasing the processing performance at increased interelectrode gaps and expanding the functional purpose. 3 ill.

Description

The utility model relates to the field of metal processing technology and other electrically conductive materials, specifically - to electrochemical installations (ECU).

Electrochemical sizing (ECM) is based on the phenomenon of anodic dissolution of a metal, carried out by the passage of current through an electrolyte, which is supplied under pressure to the interelectrode gap (IES).

The world's leading manufacturers of ECHO machines are JAPAX (Japan), CHARMILLES (Switzerland), BOSH (Germany), CHEMTOOL (USA).

The leading manufacturer in Russia is ESM LLC.

The machines they produce require the creation of specialized areas with significant areas and energy costs and are inaccessible to small and medium-sized businesses.

Taking into account that 40-60% of the total labor intensity of machine-building production falls on finishing operations, and the manufactured machines for ECHO do not have mobility and speed of restructuring for a new type of technological operation, it seems expedient to create easily reconfigurable machine tools for technological equipment (STO) for ECHO purposes.

Most of the finishing operations can be carried out according to the scheme with a fixed electrode with increased IES, namely:

- cleaning from dirt (including after casting);

- cleaning from rust and scale;

- degreasing (for welding; for paint and varnish coatings; for galvanic coatings; for adhesive joints);

- removal of applied coatings;

- oxidation (resistance to rust formation);

- improvement of surface roughness;

- applying a relief to the surface;

- removal of burrs;

- stencil electrochemical processing, including the manufacture of printed circuit boards.

Domestic installations are quite diverse - there is plenty to choose from [1. Electrochemical machines for dimensional processing. - URL: http://volga.prom-rus.com/cat-tehnologicheskoe-oborydovanie/stanki-specialnie/12760/ (date of access: 03/02/2020)].

However, each of them, along with attractive characteristics, has a number of disadvantages that restrain a potential buyer-consumer.

Known electric discharge superdrill JOEMARS TR-100 in a desktop version, the "standard configuration" of which assumes the presence of a generator and installation with a chuck, brass rod electrodes, a flushing nozzle and a sealant [2. JOEMARS TR-100 Super EDM Drill. - URL: http://www.joemars.ru/tap.htm (date of treatment 03/02/2020)].

However, it is not compact enough, transportable and relatively limited in performing various technological operations.

No close analogs of the claimed device were found in the patent array. An example of a plant for a similar purpose patented in Russia is the "Installation for electrochemical machining of holes in large-sized parts" of the Ural Electromechanical Plant [3. RU 2014112589 A, C25F 3/14, 10/10/2015]. It contains a table for fixing parts, a stand with a holder for fixing the electrode in a clamping device with the possibility of linear movement of the electrode along at least one horizontal guide, and is characterized in that the table, which is a vertically located metal plate, includes horizontally located T -shaped grooves and can be attached to the unit body; the device for the workpieces has the ability to be attached to the table by the T-shaped grooves, as well as to move along these grooves, the electrode on the stand has the ability to move along the vertical axis, in addition, the side surface of its working part repeats the shape of the hole being machined.

However, such a design is far from solving a complex of problems facing the authors of the claimed utility model (see below).

The closest analogue (prototype) to the claimed device in terms of purpose and a set of essential design features is a serially produced in Russia electrochemical installation SNE-20MK [4. SNE-20MK machine. - URL: https://www.aieco.ru/ machines_sne20mk.html (date of treatment 03/02/2020)].

It implements one of six ECS schemes (principles), namely, with a fixed electrode with increased IES. The workpiece processing scheme is presented, for example, in another source of information - [5. Electrochemical machine SNE-20MK. - URL: https://studopedia.org/2-56121.html, fig. 26, 28 (date of treatment 03/02/2020)].

The prototype installation includes an electrode unit with a holder for the workpiece and with the possibility of placing it in a container for electrolyte, an electrolyte preparation device with a pump and a filter, a power supply unit with the ability to connect to an AC source, and a control unit with means for displaying information about the technological process ...

It is made portable to parts (at least seven units) installed on the table and on the floor (see illustration in the source [4]), the power supply is designed to be connected to an alternating current source with a voltage of 380 V through a current converter, there is a control system for controller base with information display on a small-sized liquid crystal display (oscilloscope), as well as a monitoring system for the IES.

However, for all its positive qualities, the prototype device is still not perfect enough, it is limited in its technical and operational capabilities: it is not compact and mobile enough, it is suitable for a relatively narrow range of technological operations, it is poorly adapted for conducting prospecting work and when developing new technologies and modes in the field of electrochemical processes in laboratories and small businesses. The machine tool does not include technical means for electrolyte preparation, measuring and setting electrolyte consumption, heating electrolyte to a forced temperature and measuring its electrical conductivity and pH; duplication of mains power supply with autonomous power supply, as well as setting the duration of the technological process. In addition, most of the above operations using ECHO are carried out in chemically aggressive environments, the exclusion of which from technological cycles is important.

The task to be solved by the claimed utility model (device) is to develop a small-sized, portable ECU for multifunctional purposes with the possibility of using both at machine-building enterprises and in prospecting operations and in the development of new technologies and modes in the field of electrochemical processes in laboratories and small enterprises.

The technical result is the expansion of the technical and operational capabilities and characteristics of the ECS by reducing the weight and size indicators, increasing the processing performance at increased interelectrode gaps (IES) and expanding the functional purpose.

The solution to the indicated problem (task) is achieved by the fact that an electrochemical installation for processing a part made of an electrically conductive material contains an electrode unit connected with a holder of a workpiece and with the possibility of placement in a container for electrolyte, an electrolyte preparation unit with a pump and a filter, a power supply unit with the ability to connect to a source alternating current, and a control and monitoring unit with means for displaying information about the technological process, while it is made portable, arranged in a sealed case with a lid, the holder of the workpiece is made magnetic with the ability to remove reaction products from the processing zone, the electrolyte preparation unit is made in a sealed compartment case, includes an electrolyte flow meter, a heating element and an electrolyte conductivity sensor, the power supply unit is configured to be connected to an alternating current source with a voltage of 220 V through a current converter located in the case cover, and includes a backup direct current source in the form of an electric power storage for autonomous power supply, and the control and monitoring unit is configured to set and control the electrolyte consumption, set the electrolyte temperature, control the conductivity and pH of the electrolyte, set the process duration, measure and control voltage and current on the output of the installation, as well as the discharge parameters of the said energy storage.

Particular sets of essential features of the device are also aimed at solving the problem posed within the framework of the basic set of its features, formulated in the previous paragraph and further in the formula of the utility model, namely:

- the mentioned converter as part of the power supply unit can be placed in the case cover, with the exclusion of the possibility of electrical contact of the high-voltage part of the installation with the low-voltage and the device (unit) for electrolyte preparation (this radically, most effectively solves the problem of compactness, mobility and ease of use of the installation, especially for needs of scientific organizations or departments, small businesses);

- in the power supply unit, the current converter can be decoupled from the energy storage device by diodes, with the possibility of protecting the converter in the mode of operation from the storage device (it is quite simple and reliable to ensure the desired level of safety of the installation);

- the electrolyte preparation device can be made in a separate sealed compartment - the electrolyte preparation unit, with the possibility of removing it from the case (this additionally contributes to the convenience and safety of the installation in operation, storage and transportation modes);

- with the main or previous additional set of design features, the electrolyte conductivity sensor used to measure the electrolyte conductivity can be made in the form of two parallel plates with an area of 1 cm ² , installed at a distance of 1 cm, while it includes a stabilized source 3, 3 In its supply with direct current (these are rational constructive and specific geometric and dimensional features obtained by the authors when designing the installation);

- an aqueous solution of sodium nitrate - NaNO ₃ can be used as an electrolyte in the installation (this makes it possible to abandon modern chemical compositions characterized by chemical aggressiveness and non-versatility in a wide range of technological operations);

- the mentioned means of displaying information, which are part of the control unit, can include a digital multimeter, with the ability to measure and control both the voltage and current at the output of the installation, and the discharge parameters of the said energy storage device (this is, to the greatest extent, at the current level of development of metrological support, meets the tasks of operational control of the technological process and its management in a wide range of operations).

Among the array of known devices, no such were found, the set of essential features of which would coincide with the stated set of features. At the same time, it is due to the latter that a new technical result is achieved, which determines the presence of the qualification feature of the claimed device “world level of novelty”.

The second qualification feature, industrial applicability, is also indisputable and follows, first of all, from the presence of a successfully tested experimental model of the device (see Fig. 2) and the list of purchased main components of the device, the production of which is industrially mastered, given below.

The essence of the utility model is revealed in more detail in the examples below, illustrated by Figures 1-3:

in fig. 1 shows an enlarged schematic block diagram of an electrochemical installation (using the example of an option with an intermediate container for electrolyte (not formally included in the claimed kit), where the positions indicate: 1 - case; 2 - electrode block; 3 - electrode; 4 - linear electrode drive; 5 - body of electrochemical electrode tool; 6 - workpiece holder (magnetic or vacuum); 7 - workpiece; 8 - container for electrolyte; 9 - device (block) for electrolyte preparation; 10 - intermediate container for electrolyte; 11 - cleaning filter electrolyte; 12 - pump (for electrolyte); 13 - flow meter (for electrolyte); 14 - heating element (for electrolyte); 15 - electrolyte conductivity sensor; 16 - power supply unit; 17 - device for connecting to a 220 V AC network; 18 - electrical fuse (P); 19 - current converter; 20 - energy storage (electric battery); 21 - control and monitoring unit (par process meters) with means of displaying information about the process; 22 - digital multimeter (with digital voltmeter "V" and ammeter "A"); 23 - time relay (Рв); 24 - pH meter; K1 - STOP button;

in fig. 2 - 3D-image of a computer model of the claimed ECU, front-top view in an open (working) form, where the position numbers - see in Fig. 1;

in fig. 3 is a photo of an experimental sample of the claimed ECU, front-top view in an open (working) form.

The electrochemical installation contains an electrode block 2 with a holder 6 of the workpiece 7 and with the possibility of its (2) placement in a container 8 for electrolyte, a device (block) 9 for electrolyte preparation with a pump 12 and a filter 11, a power supply 16 with the ability to connect to an alternating current source , and a control and monitoring unit 21 with means for displaying information about the technological process.

It is made portable, arranged in a specialized sealed case 1. The holder 6 of the workpiece 7 is made magnetic or vacuum, with the possibility of removing the reaction products from the processing zone. The electrolyte preparation device (unit) 9 further includes an electrolyte flow meter 13, a heating element 14 and an electrolyte conductivity sensor 15. The power supply unit 16 is configured to be connected (by means of the device 17) to an AC source with a voltage of 220 V through a current converter 19 and additionally includes a redundant DC power supply 20 in the form of an electric power storage device for autonomous power supply. The control and monitoring unit 21 is configured to set and control the flow of electrolyte, set the temperature of the electrolyte, control the electrical conductivity and pH of the electrolyte, and set the duration (time) of the process.

Further features of the proposed device are private, rational, and therefore priority recommended for implementation.

The converter 19 as part of the power supply 16 is located in the cover of the case 1 (see Figs. 2, 3), with the exclusion of the possibility of electrical contact of the high-voltage part of the installation with the low-voltage and the device (block) 9 for electrolyte preparation.

In the power supply 16, the current converter 19 is decoupled from the energy storage 20 by diodes (not shown), with the possibility of protecting the converter 19 in the mode of operation from the storage.

The electrolyte preparation device 9 is made in a separate sealed compartment - the electrolyte preparation unit (9), with the possibility of removing it from case 1.

In this case, the conductivity sensor 15 used to measure the conductivity of the electrolyte can be made in the form of two parallel plates with an area of 1 cm ² , installed at a distance of 1 cm, and it includes a stabilized 3.3 V source of DC power supply (not shown ).

An aqueous solution of sodium nitrate (NaNO ₃ ) is used as an electrolyte, which is justified:

1) its non-aggressiveness;

2) the ability to process a wide range of alloy grades (armco iron, alloy cast iron, aluminum, brass, zinc, tin, lead, cobalt, tungsten, molybdenum, hardened steels, stainless steel, carbon steels, nickel) [6. Polilov L.Ya. Handbook of electrical and ultrasonic processing methods. - L .: Mechanical engineering, 1974];

3) the possibility of realizing a bipolar current lead with an insoluble electrode. In this case, the current supply to a complex surface is carried out at the current output (the share of electrical energy going to dissolve the metal of the part at low current densities, large surfaces), which allows working in the mode of a completely insoluble electrode-tool.

For NaNO ₃ , the current (see previous paragraph) is 60 mA at 20 ° C.

The information display means included in the control unit 21 include a digital multimeter 22 capable of measuring and monitoring both the voltage (V) and current (A) at the output of the installation, and the discharge parameters of the energy storage 20.

An example of the implementation of the claimed ECU (see the experimental sample in the photo of Fig. 3) uses specific, modern components mastered by the industry (which additionally convinces of the fulfillment of the patenting criterion of the utility model "industrial applicability"), in particular:

- Basic case Caliber 350 with dust and moisture resistance class. IP67;

- RS-350 current converters;

- Diodes D132-50-12 50A 1200V;

- Electricity storage (battery) lithium polymer 7080180;

- Power contactor KLIVAC EV200 1000A;

- Digital multimeter DMS-20LCD-0-5-C;

- Temperature relay TR-MO2 / 24V with temperature sensor TD-2;

- Time relay ESB40-40 40A;

- Adjustable pump FLO-2403 (2.6 lit / min);

- USN-HS06PA-4 flow sensor with US202M indicator;

- Aurus mini filter (4 degrees of purification, for domestic use);

-pH-meter EC / pH / TEMP;

- Network switch 250 / 15A;

- Fuse AGV150.

The claimed ECS works as follows.

The installation operates both from a 220 V network (when device 17 is connected) and independently from an energy storage device (battery) 20, since the power supply unit 16 includes two 6S lithium polymer batteries with a capacity of 10 Ah, which ensure the operation of the installation without a network for load of 100 A for 6 minutes, which is sufficient for most operations. Voltage and current control is carried out by a multimeter 22 (built-in digital ammeter A and voltmeter V). Starting and stopping the supply of voltage (V) to the working area occurs at the time set by the time relay 23. Emergency power off is carried out by pressing the stop button (K1). The contacts of the time relay (Рв) 23 withstand currents of 150 A for breaking the circuit. The protection of the power supply unit 16 against high currents on the power wire of the positive bus is performed by a 150 A fuse Pr. liters is sufficient for treating surfaces up to 200 cm ² . If it is necessary to carry out operations in a container (bath) of large dimensions, a container (bath) 8 of the required volume can be selected (in addition to the declared set in the case).

Before the start of the ECHO process, the electrolyte parameters are installed and controlled. Heating of the electrolyte is set by means of a temperature switch with a temperature sensor, which allows setting the electrolyte temperature with an accuracy of 1 degree. When the set temperature is reached, the relay switches off. The quality of the electrolyte, which is necessary when performing operations requiring special accuracy, is determined by the readings using the electrical conductivity sensor 15 and the pH meter 24. In case of deviation from the technological values, the electrolyte is corrected to the required parameters. The required flow rate is set by a potentiometer and controlled by a flow meter (flow sensor) 13. The flow values are displayed on the indicator of the multimeter 22.

Before the start of the ECHO process, the duration of the operation is also set, for which the required estimated time is set on the time relay (Рв) 23. After pressing the corresponding button, the time relay (Pv) 23 starts up. The power contactor is switched on and the voltage is supplied to the anode. After the processing time has elapsed, the time relay (PB) is switched off. ECHO emergency stop is provided by pressing another corresponding button. The power relay is selected to ensure open circuit at currents up to 200 A.

The installation can perform both classic piercing operations in technological equipment and operations in universal equipment that do not require a protective case. An electrochemical electrode-tool, which is a cylindrical body, fixed to the part using magnets and (or) a vacuum suction cup, ensures that the tool is held on the part. The electrolyte is pumped under a low pressure of the order of 1 atm or less. The electrode 3 is fed into the treatment zone either by a spring-loaded linear drive 4 or by a micromotor with a linear transmission.

The removal of reaction products from the treatment zone is provided by magnetic activation. Since the size of the gap at increased (as in this case) IES is measured in millimeters (1-5 mm), the removal of dissolution products does not require high pressures, which avoids jet streaks and can be organized even in a standing electrolyte. An increase in the gap makes it possible to control the intensity in the IES by dielectric shielding, as well as to reduce the shielding of the ECM process and to increase the area of the treated surface as the length of the treatment increases. Reducing the bulkiness of the equipment makes it possible to increase the mobility of a small-sized electrochemical installation when processing large-sized parts (for example, sheet-like). Increasing the clearance fundamentally eliminates the risk of short circuits and makes the equipment simple and affordable to operate. With the use of enlarged IES, it is possible to carry out active control over the changing size of the workpiece, as well as to carry out additional control using external magnetic, laser means of influence and an ultrasonic field [7. A.A. Korchagin Development of electrochemical processing methods (a review of domestic and foreign materials for 1928-1980). Series XIII №156 - Center for Scientific and Technical Information "Poisk". - 1981].

In comparison with pulse-cyclic processing methods, where the removal of ECHO products is carried out by the expansion of the IES and the processes of jet cleaning of the anode surface, work on large IES allows the use of an external magnetic field, which, when crossed with its own electric field, creates a magnetohydrodynamic action [8. Gak E. Magnetic fields and water electrolytes - in nature, research, technology. SPb .: Elmore, 2013.] and removes the products of anodic dissolution without the need to switch to a pulsed voltage supply mode. This makes it possible to increase the productivity of processing at increased IES by eliminating the loss of time for anodic etching of the workpiece 7 by eliminating the loss of time for anodic etching of the workpiece 7 by eliminating the multi-stage processing.

The magnetic-electrochemical process can be called the magnetic activation of the ECHO process.

The main functions and capabilities of the electrochemical plant (technological operations):

- cleaning from dirt (including after casting);

- cleaning from rust and scale;

- degreasing (for welding; for paint and varnish coatings; for galvanic coatings; for adhesive joints);

- removal of applied coatings;

- oxidation (resistance to rust formation);

- improvement of surface roughness;

- applying a relief to the surface;

- removal of burrs;

- stencil electrochemical processing, including the manufacture of printed circuit boards.

Installation allows:

1) receive currents up to 150 A;

2) maintain stable electrolyte parameters for a long time:

- Temperature constancy in the range from 30 to 50 ° С;

- Electrolyte consumption from 0.5 to 1.5 l / min;

- Filtration of electrolyte;

- electrolyte pH;

3) set the processing duration with an accuracy of fractions of a second.

Thus, a small-sized, portable multipurpose ECU has been proposed that can be used both at machine-building enterprises, and in prospecting operations and in the development of new technologies and modes in the field of electrochemical processes in laboratories and small enterprises. The use of such an ECS will allow expanding the technical and operational capabilities and characteristics of the installation by reducing its weight and size indicators, increasing the processing efficiency at increased IEP, expanding the functional purpose and removing the acuteness of the problem of the chemical aggressiveness of the electrolyte.

Claims (1)

An electrochemical installation for processing a part made of an electrically conductive material, containing an associated electrode unit with a holder for a workpiece and with the possibility of placement in an electrolyte container, an electrolyte preparation unit with a pump and a filter, a power supply unit with the ability to connect to an AC source, and a control and monitoring unit with by means of displaying information about the technological process, characterized in that it is made portable, arranged in a sealed case with a lid, the holder of the workpiece is made magnetic with the possibility of removing reaction products from the processing zone, the electrolyte preparation unit is made in a sealed compartment of the case, includes an electrolyte flow meter , a heating element and an electrolyte conductivity sensor, the power supply unit is configured to be connected to an alternating current source with a voltage of 220 V through a current converter located in the case cover, and includes a redundant constant source current in the form of an electric power storage for autonomous power supply, and the control and monitoring unit is configured to set and control the electrolyte consumption, set the electrolyte temperature, control the conductivity and pH of the electrolyte, set the process duration, measure and control the voltage and current at the output of the installation, as well as parameters discharge of the said storage of electricity.

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