RU2287419C2 - Apparatus for preparing ionized and ozonized cutting fluids - Google Patents

Abstract

FIELD: machine engineering, working metals by cutting.

SUBSTANCE: apparatus includes mounted in the same housing nozzle and circuit for generating high voltage. In order to provide compactness of apparatus and efficiency of metal cutting process, apparatus includes unit for pumping gaseous lubricating and cooling technological fluid with receiver for equalizing pressure and with device that improves lubrication capability of fluid. Said device may add to lubricating and cooling fluid lubricating components in different aggregate states. Nozzle is in the form injector for micro-doze feeding of gaseous fluid with lubricating component directly to zone of tool-lubricated material contact, to cutting zone and adjacent areas. Circuit for generating high voltage may generate corona discharge for positive or negative ionization of fluid. It is possible to use air flow as gaseous flow. Circuit for generating high voltage may be made with possibility for creating barrier discharge for ozonization.

EFFECT: compactness of apparatus providing improved efficiency of metal cutting process.

3 cl, 2 dwg, 2 tbl

Description

The invention relates to mechanical engineering, in particular to metal cutting processes, and in particular to devices for cooling and lubricating tools.

A known design of a device for cooling a tool with an ionized gas stream formed using a corona discharge. This device consists of a high-voltage generation unit and an air duct, in which ionization of air or another gas occurs under the influence of a corona discharge. The unit's supply voltage is 220 V. The high-voltage generation unit and the air duct are interconnected by high-voltage conductors. Ionized air is supplied to the air duct using hoses from external sources [1].

The disadvantage of this design is the high complexity of the electrical circuit of the high-voltage generation unit, as well as the difficulty in controlling the entire installation.

In industry, an apparatus is used to implement a cooling method when cutting metals with ionized air formed using a unipolar (single sign) corona discharge. The ionizing installation consists of a power supply placed in a separate housing, and a spark gap (ionizer). A spark gap with a voltage of 8 kV on the corona electrode is connected to the power supply unit by a high-voltage wire. The power supply is a high-voltage rectifier with a supply voltage of 220 V, stabilizing the mode of corona discharge that occurs in the arrester. The resulting ions and ozone are transferred to the cutting zone by means of compressed air, which is supplied through the housing of the arrester from the workshop network of compressed air connected to the arrester by a hose. Air pressure regulation is carried out using a manometer. Special filters are used to clean air from solid particles, oil, excess moisture [2].

The main disadvantage of this setup is the use of only one sign of high potential on the corona electrode.

The closest in technical essence is the installation for dry electrostatic cooling. The installation is a power supply unit, the output voltage of which varies from 0 to 8000 V, and a nozzle in which an ionizing electrode is placed. The power supply and nozzle are connected by a high voltage conductor. Compressed air is supplied to the nozzle by pipelines from the main duct. Passing through the nozzle, the air is ionized by a corona discharge and fed into the cutting zone. The ionizing electrode has a constant unipolar potential. The supply voltage of the installation is carried out from an AC network with a frequency of 50 Hz and a voltage of 220 V. The technical characteristics of this installation are given in table 1.

The main disadvantages of this device are the large dimensions and weight of the installation, as well as the presence of only one polarity on the ionizing electrode.

In addition, the main disadvantages of the considered installations include: high voltage of their power supply (220 V); block construction of installations, which leads to the need to connect power supplies and ionizing electrodes to external high-voltage (up to 8000 V) current-carrying conductors; the need for supply lines for air supply; low efficiency of installations; the impossibility of increasing the efficiency of ionized SOTS by introducing additional components into its composition; lack of protection against short circuit when exposed to foreign bodies (for example, chips) and the transition of the corona discharge in the arc.

The objective of this work is to develop a compact electrically safe installation for producing ionized and ozonized SOTS, which does not require additional supply of air ducts, and to increase the efficiency of the metalworking process.

The task is achieved in that the installation (ion-ozonizer), which is powered from the on-board network of the machine with a safe voltage of 36 V with galvanic isolation, is made in one housing (Fig. 1). The device is equipped with a nozzle installed in the housing, a high-voltage generation unit and means for injecting a gaseous lubricating-cooling technological means (COTS) with a receiver for equalizing pressure and a device for increasing the lubricating ability of COTS, through which lubricating components can be introduced into the COTS in any aggregate state, the nozzle is made in the form of an injector for microdosed supply of gaseous COTS with a lubricating component directly into the contact zone of the tool and with the processed material, the cutting zone and adjacent areas. In this case, the high voltage generation unit is configured to receive a corona discharge for positive and negative ionization of COTS, as well as to obtain a barrier discharge for ozonation of COTS.

The air flow forming unit is an adjustable air pump, which can be constructed in any design (diaphragm, plunger, rotary, centrifugal, etc.) and which is necessary for pumping the required amount of air to the SOT receiving unit and cooling the components of the electrical circuit of the high forming unit voltage.

The electrical circuit of the high voltage generation unit is shown in FIG. 2. The circuit is based on the principle of pulse-width control of a high-voltage transformer (for example, TVS-70) with the possibility of smooth adjustment and stabilization of the output voltage (4). Using a bipolar voltage multiplier allows you to get a high voltage (up to 15 kV) of both positive and negative polarity at the output of the unit. In addition, the block design provides for the possibility of replacing the voltage multiplier with a barrier discharge forming device, which is supplied with an alternating voltage of 20 kHz from the same high-voltage transformer (6). Measurement of discharge current is carried out on a low-potential wire.

The main functions of the SOTS receiving unit are: introducing finely dispersed lubricant components into the air stream, activating the obtained SOTS (air mixture with lubricant components) by applying corona or barrier discharges to it, forming a narrowly directed activated SOTS stream into the contact zone and at the same time cooling the ionized cutting zone ( ozonized) gas flow.

An alternating voltage of 36 V, galvanically isolated from the electrical network of the machine, is rectified by a push-pull rectifier, filtered (1) and fed through controlled stabilizers with an overload protection function (2, 5) to the electric motor of the air flow forming unit (3) and the high-voltage block (4) . Using resistor R1, the required speed of the air pump drive is adjusted. The magnitude of the high-voltage voltage supplied to the corona (ionizing) electrode and the electrode of the barrier discharge is regulated by a resistor R2. Ballast resistors R3, R4 protect the system from the transition of the corona discharge to the spark and arc.

The air from the room where the installation is operated (Fig. 1), with the help of an air pump (1) is pumped into the housing (2) of the installation, which simultaneously acts as a receiver. Passing to the other end of the housing to the SOTS receiving unit, the air flow cools the components of the electronic high-voltage generation circuit (3). At the entrance to the SOTS receiving unit, the air flow is divided into three parts. The first part of the flow enters the inner nozzle (4). The second part, passing through the container with the lubricating component (5) and enriched by it, is connected to the first stream at the outlet of the internal nozzle (4). In this case, the lubricating component is evenly distributed over the entire air flow passing through the internal nozzle, the output part of which (6) is simultaneously the corona electrode. The third part of the flow through a special hole (7) in the membrane (8) enters the external nozzle (9). Passing near the corona end of the inner nozzle, both streams are ionized.

The design features of the SOTS receiving unit make it possible to obtain a difference in the velocities of the expiration of air flows from the internal and external nozzles, and the internal flow rate significantly exceeds the similar characteristic of the external one. In addition, the design allows you to maintain the shape and direction of movement of the ionized air flow with the lubricating component directly into the contact zone, where the lubricating and cooling functions of the COTS are realized. Ionized air flow from the external nozzle is involved only in the cooling of the cutting zone and the adjacent areas. The regulation of the flow rates of the internal and external flows, as well as the amount of the lubricating component in the stream passing through the internal nozzle, are regulated by valves (10) and (11), respectively.

Table 1 presents the comparative characteristics of the proposed device in comparison with the prototype.

Table 1
Characteristics of the prototype and the proposed installation No. p / p Name of indicator Prototype Proposed device one 2 3 four d = 40 one Overall dimensions, mm 240 × 200 × 90 L = 165 excluding nozzle length 2 Weight kg 6.0 0.33 3 Supply voltage 220 36 four Power consumption at maximum load, W 12 fifteen 5 Voltage at the ionizing electrode, kV, no more 10 fifteen 6 Ionization current, μA, no more twenty 200 7 The number of charge polarities on the ionizing electrode, units one 2 8 The presence of the ozonizer function No Is available 9 External air supply Is required Not required

The testing of the proposed device was carried out during blade processing of representatives of various groups of structural materials: carbon steel 45, chromium steel 40X, stainless austenitic steel 12X18H10T, heat-resistant alloy VZh-98, titanium alloys VT6, VT5-1. The cutting was carried out on the operations of turning and milling with tools made of high-speed steels P6M5, P9 and equipped with hard alloy plates T5K10, T15K6, VK6. As the lubricating component, we used: finely dispersed powders of molybdenum disulfide MoS ₂ , copper, aluminum, magnetic microcapsules according to [4], and industrial oil I-40A.

Examples of using the proposed installation.

In the operations of turning titanium alloy VT5-1, carbon steel 45 and austenitic stainless steel 12X18H10T, the cutting was carried out by stop-boring cutters from high-speed steel P6M5 at a cutting depth of t = 0.5 mm and a feed S = 0.1 mm / rev. Cutting speeds V corresponded to 0.39, 1.24 and 0.48 m / s. To obtain SOTS, a prototype (Varkash installation according to [3]) and the proposed installation were used. As an additional lubricating component for the proposed installation, magnetic microcapsules with sizes of 10-50 microns in the amount of 0.3 g / hour were used. The distance from the nozzle to the contact zone in both cases was 60 mm. The wear criterion was the chamfer of wear along the back surface of a cutter 0.6 mm high. The results of changing the resistance characteristics of the tools are given in table.2.

The ratio of the results of blade processing for various operations of other processed and tool materials is close to those given in the table.

Information sources

1. RF patent No. 2156927. Device for cooling the tool. Authors: Trifonov ON, Panin MG

2. Kholmogortsev Yu.P. Dry electrostatic cooling during gear hobbing. // Bulletin of mechanical engineering. 2001. No1. S.45-46.

3. UK Patent GB No. 2243319 B Apparatus for machining materials by cutting. Invantors: Akhmetzyanov I.D., Vereschagin I.P., Dogadin G.S., Lilin V.I., Suslov A.D., Terentiev A.G.

4. RF patent №2147923. A method of obtaining microcapsules. Authors: Latyshev V.N., Naumov A.G., Chirkin S.A., Pribylov A.N.

Claims (3)

1. A device for cooling tools with an ionized gas stream, comprising a nozzle and a high-voltage generation unit installed in one housing, characterized in that it is equipped with means for injecting a gaseous cutting fluid with a receiver for pressure equalization and a device to increase the lubricating ability of COTS, made with the possibility of introducing lubricating components into the composition of COTS in various aggregate states, the nozzle being made in ide mikrodozirovannoy injector for feeding a gaseous cutting fluid with the lubricating component directly to the nip tool with a workpiece material, the cutting area and surrounding area, and the high voltage generating unit has a supply voltage of 36 V. 2. The device according to claim 1, characterized in that the high voltage generation unit is configured to create a corona discharge for positive or negative ionization of the COTS. 3. The device according to claim 1, characterized in that the air flow is used as the gaseous stream, and the high voltage generation unit is configured to create a barrier discharge for the ozonation of COTS.

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