JPS5914431A - Dielectric fluid processor for electrical machining - Google Patents

Abstract

PURPOSE:To achieve the circulation of a dielectric fluid economically for reusing, by heating the dielectric fluid containing a surface active agent whose solubility is reduced by a temperature rise, while recovering the surface active agent so as to be reused. CONSTITUTION:A substrate that is mixed with a surface active agent whose solubility is remakably reduced by a temperature rise is used for a dielectric fluid available in electrical machining such as electric discharge machining, etc. The dielectric fluid after being used in machining is led into a regnerative processing tank 8 after precipitating machining chips or the like in a setting tank 5, then heated by a heating device 11 and simultaneously stirred up by a stirrer 12. Iron powder 14 settled inside the regenerative processing tank 8 is made to stick to the surface active agent in time of heating. On the other hand, the dielectric fluid after separation is fed to an oil separator tank 15, and the residual iron powder 14 is poured with cooling water whereby the sticking surface active agent is redissolved. Thus the solution is circulated and mixed in the dielectric fluid for reusing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a machining fluid treatment device in an electrical machining device such as electrical discharge machining using an electrical discharge machining fluid containing water as a main component.

In the field of drilling and die-sinking using rod-shaped or contracted electrodes in the field of electric discharge machining, hydrocarbon oils such as kerosene (white kerosene) and transformer oil are usually used as machining fluids. On the other hand, in the field of so-called wire-cut electrical discharge machining that uses wire electrodes, water, water,
In particular, pure water-based products have come into regular use.

In the former case, kerosene is sometimes used because it is convenient for preventing rust in the machine, but it is generally used in the processing condition range of finishing processing where the processing speed is slow but the machined surface roughness is small and dimensional accuracy is high. The machining performance of each type is generally superior to the others over the entire machining condition range, from rough machining where the surface roughness is rough but the machining speed is high, and the machining performance is proportional to the set machining conditions. It can be obtained stably, is relatively inexpensive and easy to handle, has a relatively long life, and does not cause any particular pollution problems or is relatively easy to dispose of during processing and after-treatment such as disposal. It is thought that this is due to a number of reasons.

The biggest drawback of hydrocarbon oil-based machining fluids such as kerosene and transformer oil is that they are flammable, and electrical machining such as electrical discharge machining is not suitable.・A pair of electrodes (one is a machining electrode and the other is a workpiece) are placed opposite each other with a minute gap in or through the machining fluid, and current is applied to the gap to generate intermittent electrical discharge and Machining is performed by continuously generating and maintaining electrical discharge, etc. On the other hand, this type of electrical machining equipment can perform automatic machining without the operator being constantly in contact with the machine during operation. Because the processing fluid used is kerosene with various additives added to raise the ignition temperature, automatic fire extinguishing devices for fire detection have recently been introduced. Due to the situation in which each electric discharge machining device is attached, there is still a risk of ignition and fire.
For this reason, although it is a machine device for automatic operation as described above, it is difficult to operate it unmanned and/or overnight. The latter processing liquid water poses no danger of fire or the like, and even if various additives such as rust preventive agents are required, they are extremely cheap, easy to dispose of, and are still resistant to human skin like hydrocarbon oils. It has various advantages over hydrocarbon oil-based machining fluids, such as those that do not cause any damage to the machining surface. It is fully comparable to hydrocarbon oil-based machining fluids in the so-called finishing machining condition range where the roughness is approximately several 10 μRmax or less, and in the machining condition area close to medium machining or rough machining with machined surface roughness of the above degree or higher. In addition, when the machining area of the machining electrode becomes large, the machining speed may drop dramatically, machining becomes difficult, and electrode consumption increases, making it difficult to perform machining with low electrode consumption. For this reason, the machining liquid water described above has the disadvantage that the machining conditions are limited to the machining condition range of so-called finishing machining. It is usually only used in numerical control systems.

However, insofar as the so-called pure water of 5'-xIO3 Ωcm or more is used as the machining fluid (of course, it also includes those to which many rust preventives, etc., are added), machining voltage pulses (or discharge current pulses) ) width (τon or τD) is approximately 30~
When the machining conditions are around or above 20μRmax, that is, the medium machining conditions or higher, for example, the voltage pulse (τ
Exceptionally special machining conditions, such as when the no-load voltage (on) is made exceptionally large, or when the electrical discharge amplitude (IJ) of the electrical discharge source pulse (τD) is made exceptionally large, i.e., when the conventional normal voltage pulse (τ.11) or the discharge pulse (τ full and, if necessary, the voltage pulse (τo11), the body dwell time (τo
ff), or to the extent that they are devised to the extent that is relatively easily possible, the current situation is that it cannot be put to practical use due to the sudden decrease in processing speed, increase in electrode wear, etc. as described above. .

Therefore, the present inventors have already mixed water as the main component with less than 10 or more surfactants, or in addition,
At the same time, electrical discharge machining fluid is mixed with a conventional machining fluid component of hydrocarbon oil in an amount of around several inches, or fine conductive powder such as metal powder with a diameter of around several μm or less is added in a volume ratio (apparent) of less than 1 inch. We are developing an electrical discharge machining fluid with a trace amount of added. If an electrical discharge machining fluid containing a small amount of a surface active agent or a hydrocarbon oil is used, the machining speed will decrease and the degree of electrode wear will be reduced, and there is no risk of fire. Single processing can be performed by unmanned operation.

However, such surfactants have the disadvantage that they are generally expensive.

For this reason, for example, in the inventions of earlier applications such as Japanese Patent Application No. 56-176.128 and Japanese Patent Application No. 56-181,567, the machining fluid containing the above-mentioned surfactant is hardly wasted. We proposed a new electrical discharge machining method that would completely consume the material. That is,
For example, ``intermittent voltage pulses are applied to the opposed micro-machining gap, which is formed by facing each other with a micro-interval between the processing electrode and the workpiece electrode, and into which the processing fluid is supplied, with a pause period in between. In the electric machining method, the part of the workpiece electrode facing the machining electrode is removed by the electric discharge generated by the process, and the machining gap is maintained and controlled as the machining progresses. Using a substantially non-flammable aqueous machining fluid containing water as the main component as the machining fluid; 1. Using a full-type electrode such as a perforation or engraving having a machining area of around several cA or more as the machining electrode;
With the machining electrode and the workpiece electrode arranged in air so that at least the machining gap is formed and maintained in the air outside of the stored machining liquid, the machining liquid is continuously or When machining is performed by intermittently injecting and discharging,
The electric discharge maintains a state in which machining gap inclusions and products such as electric discharge machining debris, sparks, machining fluid, and their decomposition products eject and scatter into the surrounding air from the outer peripheral edge of the machining gap. The electric machining method O, Jb is characterized in that the supply injection of the machining fluid into the machining gap is limited and controlled so that the machining progresses. Ideally, limit control is such that almost all of the machining fluid supplied to the machining gap is used up through vaporization, vaporization, decomposition, combustion, etc., but depending on the machining area and machining shape. , the shape of the machining electrode, how to set up the machining fluid supply nozzle, how to form or install the machining fluid supply path and opening on the electrode or the workpiece, the machining shape according to the progress of machining, machining conditions, or machining state, etc. Depending on the situation, the above-mentioned machining fluid may be sprayed and supplied to the machining gap at a supply amount several times larger than that which is consumed in the machining gap as described above, or as a result, such machining fluid may be supplied. If this is unavoidable, as described in the above-mentioned prior invention, a part or more of the excessively supplied machining fluid can be disposed of as machining waste and disposed of as a machining fluid source (for example, Processing waste that does not contain active ingredients such as surfactants, water that contains combustion residue of active ingredients, etc.) is collected in a mixed state, and the solid components are separated and other treatments are performed before being recirculated and supplied. However, the treatment was rather difficult.

In other words, water other than the usually expensive surfactant (purified water), hydrocarbon oils such as spindle oil added in small amounts as necessary, and others added as necessary such as rust preventives. Since these additives are relatively inexpensive, it is not necessarily necessary to recover them. However, if you attempt to recover the above-mentioned surfactants while they are dissolved in water, various impurities generated during electrical discharge machining cannot be separated and removed. Therefore, the specific resistance of the machining fluid could not be improved or recovered, and the regeneration treatment of the machining fluid was difficult.

That is, in the treatment of the above-mentioned processing fluid, it is necessary to separate the organic matter such as surfactant and hydrocarbon oil into the organic matter such as water and other inorganic matter, and then deionize the latter. It was difficult to regenerate the processing fluid and recover and reuse the surfactant except by discarding the latter and using new pure water or the like.

The present invention has the advantage that there is no fear of the occurrence of fire, etc., unmanned overnight operation is possible, and it can be realized economically, or it further contains a small amount of hydrocarbon oil or fine conductive powder. An object of the present invention is to provide a machining fluid processing device in an electrical discharge machining machine that uses an electrical discharge machining fluid whose main component is water.

The present invention aims to recover and reuse an expensive surfactant after use. and a surfactant recovery device that heats the processed liquid and separates it from water as a solid content, and the surfactant recovery device includes a regeneration treatment tank that stores the processed liquid, and a regeneration treatment tank that stores the processed liquid and A heating device that heats the processed liquid in the treatment tank to a temperature above the cloud point, a deposit that promotes separation of the surfactant by adhering the surfactant that precipitates by heating, and a A stirring device that stirs the processed liquid, a device that discharges the supernatant liquid with the surfactant deposited to the outside of the regeneration treatment tank, and a device that discharges water (pure water) into the regeneration treatment tank after discharging the supernatant liquid. ) into the water to reduce the temperature and redissolve the surfactant in water.

By adopting such a structure, electric discharge machining using a water-based machining fluid as described in the invention of the earlier application such as the above-mentioned Japanese Patent Application No. 1987-1.76.128 can be improved from the viewpoint of the machining fluid. In addition to making it economically practical, the water-based machining fluid can also be used in conventional electric discharge machining methods other than the special electric discharge machining method described in the prior invention. Even when used in mahi, so-called wire-cut electric discharge machining, machining performance is equivalent to or higher than that of water (pure water), and electrode consumption is small, so it is thought to be useful.

The present invention will be explained below with reference to the drawings. 1 is supplied to the machining gap between the electrode 2 and the workpiece 3 in a limited manner in the required amount, and the used electrical discharge machining fluid 4 containing machining waste, decomposition products, etc. is collected as described later. At least the surfactant contained therein can be recovered and reused.

In the present invention, as the electrical discharge machining fluid 4, an aqueous solution containing water as a main component and mixed with at least a surfactant to give it a red and black color is used. The processed liquid after being used in the electrical discharge machining tank 1 is led to a settling tank 5, where machining waste 10 and other produced solids are precipitated. The sedimentation tank 5 is provided with two limit switches LS, , 'LS2 for detecting the liquid level with an interval in the vertical direction, and a pushing device 7 is also provided. Reference numeral 8 denotes a regeneration treatment tank, and the regeneration treatment tank 78 has a volume that is approximately a fraction of the volume of the sedimentation tank 5. When the limit switch LS is activated, the pump 9 and the piping 9a move to the sedimentation tank 5. The processed liquid inside is introduced into the regeneration treatment tank 8, and when the limit switch LS2 or LS3 is activated, the introduction is stopped.

Inside the regeneration treatment tank 8, there is a heating device 11 that heats the processed liquid from which most of the solids have been removed by precipitation to a temperature higher than red and black;
A stirring device 12, a temperature sensor 13, and limit switches LS3 and LS4 for detecting the liquid level are installed, and fine powder, such as iron powder 14, to which a surfactant adheres during heating is deposited.

15 is from the processing liquid source (mostly water, pumped up from the recycling tank 8), which does not contain a surfactant and is disposed of when oil such as kerosene oil is mixed in the processing liquid. This oil separation tank is provided to separate and collect oil and partially pumped iron powder (including some processing scraps), and the regeneration treatment tank 8 and the oil separation tank 15 have a pump 16. A discharge pipe 17 is connected to a return pipe 19 with an iron powder having a pump 18 (if the temperature is maintained, some of the surface active agent will adhere to it). The system separates oil from water (drained liquid) by separating the oil from the water (drainage liquid).It is divided into an oil separation side and a discharge side by an intermediate partition plate 20.A filter 21 for removing iron powder and processing waste is installed on the discharge side. 2
A concentration sensor 22 for ions generated by processing is provided on the drain outlet side of the drain 1, and after the concentration sensor 22 detects the concentration, the drain is discharged to a drain pipe 23.

The pump 18 is operated as appropriate to remove the deposited iron powder from the regeneration treatment tank 8.
This prevents the iron powder in the treatment tank 8 from being consumed or wasted.

24 is a solution in which a surfactant is dissolved by injecting cold pure water, and when the solution is pumped up from the processing tank 8 and reused as a processing liquid, the iron powder that is pumped up at the same time is separated by sedimentation from the pumped processing liquid. The iron powder separation tank 24 and the regeneration treatment tank 8. a reusable machining fluid suction pipe 26 with a pump 25; and an iron powder return pipe 2 with a pump 27.
It is connected to 8. Reference numeral 29 indicates a filter provided as necessary to remove iron powder from the machining fluid pumped up from the processing tank 8, and 30 indicates a filter that removes the iron powder from the filter and transfers the machining fluid to the machining fluid tank 31 for reuse. In the machining liquid tank 31, oil such as kerosene oil, surfactant, and others 32 are mixed for addition or replenishment in the required amount as necessary, and a pump 33 is used to remove valves 34 and piping. 35
．． It is supplied from one or both of the electrode 2 or the processing tank 1 via the electrode 2 or the processing tank 1 to the processing gap between the workpiece 3 or to fill the processing tank 1.

37 An ion exchange resin removes ions from the tap water 38; 39 is a pure water tank for storing pure water after ion removal; It joins with the supernatant liquid through a piping 42 having a valve 43 and can be supplied to the processing parts such as the electrode 2, and is then supplied to the regeneration treatment tank 8 as cold pure water through a piping 44 having a valve 43. It is now possible to introduce it.

Next, the operation of this device will be explained. The processed liquid in the processing tank 1 is supplied to the settling tank 5, and when the liquid level reaches the limit switch LS, the pump 9, which is turned on, causes the processed liquid to flow into the regeneration processing tank 8, and When the liquid level in the treatment tank 8 reaches the limit switch LS, the pump 9 is switched off and then heated, preferably rapidly, by a heating device 11. For example, 05 m/Se
Forcibly at a speed of c, that is, the iron powder 14 is suspended in the processing tank 8.
Stir so that it moves around evenly. When the processed liquid is heated to a temperature above red-black (for example, 55'C), the surfactant in the processed liquid is adsorbed to the surface of the iron powder, and the amount of iron powder 14 is sufficient for the surface active agent. Almost all of the surface active agent dissolved in the processed liquid was iron powder 1.
It is adsorbed on the surface of 4, and thus settles to the bottom of the regeneration treatment tank 8 by stopping 1'1. On the other hand, ions generated by electrical discharge machining are left behind in the supernatant liquid, and most of the decomposition products from each tank that are still floating in water remain in the supernatant liquid, and if oil is mixed in, Oil also remains in the liquid or floats to the surface. Therefore, the supernatant liquid is pumped into the oil separation tank 15 by the pump 16 until the lower limit switch LS4 is activated, after a settling time of a certain amount after the agitation is stopped, or by forcible sedimentation using, for example, magnetic means. It can be removed by introducing it into the room and letting it stand. Further, oil can be recovered in an oil separation tank 15 if necessary. The processed liquid from which oil and solids have been removed by the filter 21 is water with reduced purity, so it may be supplied to the resin tank 37 and reused, but since this may damage the resin 37, it is usually is drain pipe 2
It is discharged through 3.

After discharging the clear liquid, open the valve 43 and pump 4.
0 is driven to limit the pure water in the pure water tank 39 (preferably cold water, so a cooling device is provided between the tank 39 and the tank 39 if necessary) to the regeneration treatment tank 8 via the piping 44. By flowing in and stirring until the switch LS3 is activated, the iron powder 14 to which the surfactant is attached is suspended, and the surfactant adsorbed to the iron powder is dissolved in the water and processed. Regenerate as liquid. The recycled machining fluid is stirred and settled to separate iron powder, and the supernatant regenerated machining fluid is passed through an iron powder separation tank 24 and a filter 29 to sufficiently remove iron powder, and the machining fluid is passed through a return pipe 30. The liquid is returned to the machining liquid tank 31, and oil such as kerosene oil, a surfactant, and others 32 are added or replenished as necessary and mixed. It is supplied to other processing departments.

In addition, in the specific example of the above-mentioned embodiment, the volume up to the limit switch LS above the regeneration treatment tank 8 is 10
7? The amount of processing per time is 61. Processing capacity of 2 or more per minute
00cc/tni, one cycle time 30
It was a minute. And the recovery rate of the surfactant in this case is 95
%Met.

In addition, for example, in electric discharge machining as described in the invention of the prior application such as the aforementioned Japanese Patent Application No. 56-181,567, the flow rate of machining fluid changes depending on the machining conditions (electrical conditions) and the degree of releasability of the machining shape. The flow rate fR and the optimal minimum flow rate f(v)m
LrLLr is as follows.

/R= f (v)miyb + F Here, f(v)m ot□ is the voltage pulse τ. 1. and current pulse Ip, etc., and F is the flow rate that is not involved in machining, that is, the flow rate that is used to supply machining fluid to each part of the machining gap as desired depending on the machining shape, machining conditions, etc. is the flow rate of machining fluid that was excessive even though it was necessary to supply machining fluid in excess of the required amount. The flow rate F that does not cause any opening force during this machining is unused machining fluid, and therefore the total supply amount FT of pure water (machining fluid) that needs to be supplied to the machining parts such as the electrode 2 is as follows: FT = F +f (v) It becomes mirLxα. However, α is a coefficient that changes depending on the processing conditions. By controlling the total pure water supply amount F7, the recycled machining fluid is obtained. Such pure water may be supplied not only to the regeneration treatment tank 8 but also to the processing liquid tank 31. You can also do this. In the illustrated embodiment, the processed liquid is treated in the treatment tank 8 to cause the surfactant to adhere to and settle on the iron powder 14, and the supernatant liquid is pumped out to the oil-water separation tank 15 by the pump 16, and then to the pure water tank. If the amount of pure water supplied to the processing tank 8 by the pump 40 from 39 corresponds exactly to the unused flow rate of the processing fluid, the surfactant in the liquid returned to the liquid tank 31 by the piping 30 will be reduced. The concentration of is the same as that of the initial unused machining fluid, but the flow rate α×f(v)nLLrL consumed by machining varies considerably depending on the momentary machining state of the machining gap, etc. The amount of pure water supplied from the pure water tank 39 to the processing tank 8 is more than the amount of pure water corresponding to the above flow rate, for example: - Processed liquid treated in the processing tank 8, that is, oil-water separation tank 1'''5 It is desirable to adjust the concentration of the surfactant and other substances in the machining liquid tank 31 or at a stage before it, with the liquid pumped up to about 60q6.Of course, if necessary, the flow rate α× f(v), ntt, etc. may be detected and the amount of pure water supplied to the processing tank 8 by the pump 40 may be automatically controlled each time.

The surfactant may be a polyethylene glycol type nonionic surfactant, a lauryl alcohol to which ethylene oxide is added, a nonylphenol type surfactant, or a surfactant as described in the aforementioned earlier Japanese Patent Application No. 17-17-6,128. Various silicone oil-based surfactants listed above or alkylphenol-based ones are used, and the mixing amount of these is preferably about 0.1 to 15% by weight, particularly about 0.1 to 5%. .

In addition, in order to prevent an increase in the wear amount of the electrodes, or to stabilize machining performance such as machining speed, a hydrocarbon oil such as spindle oil or kerosene oil is added to about 10 parts or less, preferably 4 to 5 parts. Add around a few inches below
Further, if necessary, it is preferable to mix about 001 to 05% conductive powder such as fine metal powder in order to stabilize the processing state and improve the processing speed. The above-mentioned hydrocarbon oil is uniformly dispersed in the form of minute oil droplets in water, which is the main component, by adding the above-mentioned surfactant. The iron powder added for magnetic field separation is approximately 0.1μ to 20μ for high-speed separation if it is still a deposit in the treatment tank 8.
The size of the mixture is about 0.1~1% by weight.
It is desirable that it be about 0. Note that when magnetic field separation is not used, sand, other ceramic powder, non-magnetic metal powder, or the like that does not dissolve in water can be used in place of the iron powder. In addition to separating by applying a magnetic field, electrostatic or dielectric separation can be performed by using dielectric powder such as synthetic resin powder instead of iron powder and applying a DC or AC electric field.
However, as mentioned above, add graphite to the machining fluid as necessary.
In the case of a water-based electrical discharge machining fluid that is used for electrical discharge machining with the addition of fine powders of iron, copper, nickel, zinc, etc., iron powder 14
To assist in this process, the processing waste and the fine powder may be used as adsorbent powder in the processing tank 8. In any case, if the amount of adsorbed materials such as iron powder in the treatment tank 8 decreases, the intended treatment in the treatment tank 8 cannot be performed, so supplementary treatment is performed in the oil separation tank 15 and the separation tank 24. The structure is such that the water is returned to tank 8. Further, instead of powder, various types of steel materials may be used as objects to be adsorbed by inserting them in multiple cylindrical shapes around the pushing tool and between the inner circumferential wall of the processing tank 8.

In addition, to explain the separation effect due to the above-mentioned magnetic field and electric field using experimental results, after electrical discharge machining with a machining fluid in which 1 part of non-ionic silicone oil-based surfactant and 1 part of spindle oil were added to water with a specific resistance of 105 Ωcm. , 1% nonyphenol mixed with 12 moles of ethylene oxide,
Furthermore, 15 pieces of 5 μφ iron powder were mixed and stirred to 65
When heated to 'C, the activator adheres to the iron powder and processing waste,
Separated from water spindle oil and other water-dissolved substances, it is allowed to settle by natural precipitation for about 3 hours, the supernatant liquid is pumped out, the precipitate is cooled, and pure water is added to dissolve it.
Approximately 96 pieces of surfactant were recovered. However, when a magnetic field of 1100'G (Gauss) was applied to the above-mentioned punching machine, 995% of the processing waste and surfactant were precipitated and separated in 35 minutes. It could then be recovered by dissolving in water. When a DC magnetic field was applied, 98 chips were recovered.

In the above embodiment, the supernatant liquid in the regeneration treatment tank β is discharged after solids such as iron powder and oil and water are separated, but it is preferable to pass the supernatant liquid through an ion exchange resin and reuse it. You can also do this.

Reusing the supernatant fluid saves water and eliminates pollution problems caused by discharge of electrical discharge machining fluid.

Table 1 shows the experimental results of electrical discharge machining using an electrical discharge machining fluid using polyether-modified silicone oil as a surface active agent. In the experiment, a copper electrode with a diameter of about 30 mm was used as a processing electrode, and a diameter of 555 mm was used.
C iron material is the workpiece, and the duration of the voltage pulse (τOn
) approx. 60 μs 1 body IE time (τoff ) approx. 20 μs1
The amplitude (Ip) of the discharge current was set to approximately 45 A, and various machining fluids were used to obtain the results shown in Table 1 below.

Table 1 In the above table, A is when pure water with a specific resistance of about 0.5 x 10' Ωcm is used as the machining fluid, and B is when a solution consisting of water from A above is used as the machining fluid. In this case, C is a machining fluid that can be purchased as an electrical discharge machining fluid at a gas station, etc., and the ignition point is raised by additives, but if a hydrocarbon oil consisting essentially of kerosene is used as the machining fluid, D, E, F; G are the experimental results of the present invention, and are sold by Shin-Etsu Chemical Co., Ltd. under the product name KF-352, with a viscosity of approximately 1,600C8 (25″c) and a specific gravity of approximately 1.03 (25°C). ), refractive index approximately 1.446 (25'
c) Polyether-modified silicone oil is added to the water in A above, D is about 0.2 inch, E is about 0.5 inch, F is about 1.0 inch.
%, G is when approximately 20 pieces are each dissolved to make a processing liquid,
Numerical values without parentheses are the results of electric discharge machining in the conventional normal machining mode, as in the case of A, B, C added, and superfluid, whereas the numerical values with parentheses are the results of electric discharge machining in the conventional machining mode. This is the case when applied to the novel electric discharge machining method described above.

Above, the present invention has been explained about the so-called electric discharge machining fluid for electrical machining and the electric discharge machining method using the machining fluid. , NaNO3, NaNO2++KNO
3+ KNO24-Na2 co3. -An electrolyte cap such as NaOH 1! Can be used as a machining fluid for electrolytic discharge machining or electric discharge electrolytic machining by adding one or more kinds 0
As described above, in the present invention, as the electrical discharge machining fluid, a fluid whose main component is water containing a red and black surface active agent is used, so that, for example, numerically controlled electrical discharge machining can be carried out unattended all night. It goes without saying that it is now possible to recover the expensive surfactant added to water, the main component, without wasting it by discarding it, or until the surfactant is decomposed or wasted by the electric discharge machining action. Since it can be used as a material, there is an advantage that electrical discharge machining can be carried out more economically than in the case of using conventional kerosene.

Further, in the present invention, since the processing liquid is regenerated through a series of operations of heating the processed liquid in the regeneration treatment tank, discharging the supernatant liquid, and adding pure water, the surfactant is separated. Therefore, the device can be realized economically without requiring a filter or the like.

[Brief explanation of the drawing]

The drawing is a system diagram showing one embodiment of the present invention. 8... Regeneration treatment tank, 11... Heating device, 12... Stirring device, 15... Oil separation tank, 39... Pure water tank Patent applicant Inoue Japax Institute Co., Ltd. Agent Patent attorney Young 1) Win −

Claims (1)

[Scope of Claims] 1. In an electrical processing device that uses an aqueous solution mixed with a surfactant as a machining fluid, a surfactant whose solubility greatly decreases as the temperature of the aqueous solution increases, and The surfactant recovery device is configured to heat the processed liquid and separate it from water as a solid content, and the surfactant recovery device includes: - a regeneration treatment tank for storing the processed liquid;
A deposit that promotes separation of the surfactant by adhering the surfactant precipitated by heating, an agitation device that stirs the processed liquid in the reprocessing tank, and a A supernatant liquid discharge device that discharges the supernatant liquid to the outside of the regeneration treatment tank, and a surface active agent that is redissolved in the water by lowering the temperature by flowing water into the regeneration treatment tank after the supernatant liquid is discharged. A machining fluid treatment device for electrical machining, characterized in that it is equipped with a water supply device. 2. The machining fluid treatment device for electrical machining according to claim 1, wherein the machining fluid further contains hydrocarbon oil, and the supernatant fluid discharge device includes an oil recovery device.