Circulating electrolytic coolant generation system and electrolytic treatment device for coolant regeneration applied to said system

Abstract

To efficiently regenerate and utilize a used coolant liquid by using an electrolytic treatment device.SOLUTION: A circulation type electrolysis coolant liquid generation system comprises: a coolant liquid tank which stores a used coolant liquid; an electrolytic treatment device which includes an anode tank that receives the used coolant liquid and a cathode tank that receives a diluted coolant liquid; a reutilization tank which stores the diluted coolant liquid containing an electrolysis coolant liquid subjected to the electrolytic treatment in the anode tank and water; and water feeding means which can feed the used coolant liquid to the anode tank, as well as, the diluted coolant liquid to the cathode tank. The used coolant liquid is fed to the reutilization tank after being subjected to the electrolytic treatment in the anode tank and the diluted coolant liquid is subjected to the electrolytic treatment in the cathode tank, and then, refluxed to the coolant liquid tank.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technology for purifying coolant used in machining processes such as cutting and grinding, and more particularly to a circulating electrolytic coolant generation system that efficiently recycles used coolant, and an electrolytic treatment device for coolant regeneration that is applied to the system. [Background technology]

[0002] In known processing devices that process workpieces such as metal parts, water-soluble coolant liquids or oil-based coolant liquids may be used for the purpose of cooling the frictional heat generated between the processing tool and the workpiece, preventing rust, and maintaining lubrication.

[0003] For example, water-soluble coolants have many advantages, such as not excessively soiling the workpiece or processing tools, and are therefore used in a variety of processing equipment.However, even water-soluble coolants can have problems, such as the proliferation of bacteria over long periods of use, which can cause a foul odor, changes in pH value and viscosity, resulting in a decline in processing performance, and the cost of having to have specialized disposal companies handle the disposal because it is difficult to dispose of.

[0004] To address this issue, there is a technique for purifying coolant using an electrolytic treatment device capable of applying a desired voltage, as exemplified by the following patent document. For example, Patent Document 1 discloses a coolant liquid purification device in which at least one pair of cathode and anode electrically connected to a DC power source is placed in a storage tank provided in a coolant circulation path, and metal ions are precipitated and recovered on the surface of the cathode by the electrochemical action between the cathode and anode.

[0005] On the other hand, Patent Document 2 discloses a technique for diluting and mixing a water-soluble coolant concentrate solution using electrolytic ionized water obtained by electrolysis, the pH value of which is 8.0 or more and 13.0 or less, and / or the oxidation-reduction potential of which is -100 mV to -1000 mV. Furthermore, Patent Document 3 listed below proposes a water-soluble coolant purification device equipped with a recovery means for peeling off or separating at least one of the substances deposited on and adsorbed on the surfaces of the cathode and anode plates and precipitating it at the bottom of the electrolytic cell. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-011661 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-167594 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-166176 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the prior art including the above-mentioned patent documents still has the following problems and there is much room for improvement. That is, it is certainly possible to purify the coolant to some extent by utilizing an electrolytic treatment device as shown in Patent Documents 1 to 3. However, for example, in the configurations of Patent Documents 1 and 3, metal ions are deposited on the cathode of the electrolytic treatment device, and there is a concern that if a large number of metal ions remain deposited and fixed on the surface of the cathode, maintenance will become very complicated and require a large amount of cost.

[0008] On the other hand, according to Patent Document 2, the water-soluble coolant stock solution is diluted and mixed using electrolytic ionized water, so maintenance of the electrolytic treatment device itself is not particularly complicated. However, since there is basically no consideration for recycling the coolant liquid after use, it must be said that there is still a lot of waste. As described above, the conventional technologies including those mentioned in the patent documents do not provide any perspective on efficiently recycling used coolant liquid while minimizing the complexity of maintenance, and it can be said that there is considerable room for improvement.

[0009] The present invention has been made in consideration of the above-mentioned problems as an example, and aims to provide a circulating electrolytic coolant liquid generation system that uses an electrolytic treatment device to efficiently recycle used coolant liquid and enable easy wastewater treatment of coolant water at low cost, and an electrolytic treatment device for coolant regeneration that is applied to the system. [Means for solving the problem]

[0010] In order to solve the above problems, a circulation type electrolytic coolant generating system according to one embodiment of the present invention includes: (1) a coolant tank for storing used coolant used in processing a workpiece; and (2) a coolant receiving device connected to the coolant tank for receiving the used coolant stored in the coolant tank. liquid and a cathode cell separated from the anode cell by an ion-exchangeable diaphragm; reuse tanks connected to the anode cell and the cathode cell, respectively, for storing diluted coolant liquid produced by diluting the electrolytic coolant liquid electrolyzed in the anode cell with water; and a reuse tank for sending the used coolant liquid to the anode cell. liquid At the same time, the diluted coolant liquid is sent to the cathode tank. liquid Possible delivery liquid and a coolant tank for supplying the diluted coolant to the coolant tank after the diluted coolant is electrolyzed in the cathode tank. liquid The used coolant is electrolyzed in the anode tank and then sent to the reuse tank. liquid It is characterized in that

[0011] In the circulation type electrolytic coolant generating system described in (1) above, (2) the coolant is sent from the reuse tank to the cathode tank. liquid and an electrolysis auxiliary agent adding means for adding an electrolysis auxiliary agent to the diluted coolant solution to be electrolyzed, and the diluted coolant solution to which the electrolysis auxiliary agent has been added is electrolyzed in the cathode cell.

[0012] Furthermore, in the circulating electrolytic coolant generation system described in (2) above, it is preferable that (3) it further includes a control device that controls the operation of the electrolytic treatment device and the amount of the electrolytic auxiliary agent added, and that the control device adjusts the amount of the electrolytic auxiliary agent added to the diluted coolant solution depending on the number of times voltage is applied in the electrolytic treatment device.

[0013] In the circulation type electrolytic coolant generating system described in any one of (1) to (3) above, (4) the coolant is sent from the coolant tank to the anode tank. liquid It is preferable that the used coolant further includes a foreign matter removal filter that removes foreign matter by performing solid-liquid separation and oil-water separation on the used coolant, and the used coolant from which the foreign matter has been removed is electrolyzed in the anode tank.

[0014] Furthermore, in order to solve the above problems, an electrolytic treatment device for coolant regeneration applicable to a circulation type electrolytic coolant generation system according to one embodiment of the present invention is (5) an electrolytic treatment device for coolant regeneration used in a circulation type electrolytic coolant generation system described in any one of (1) to (4) above, comprising an ion-exchangeable diaphragm and a coolant tank for receiving used coolant stored in the coolant tank. liquid The anode tank is separated from the anode tank by the diaphragm and is fed from the reuse tank. liquid Receive the diluted coolant liquid and a control device that applies a predetermined voltage between an anode installed in the anode cell and a cathode installed in the cathode cell via a power source.

[0015] In order to further solve the above-mentioned problems, a method for recycling coolant according to one embodiment of the present invention includes a step of processing a workpiece using a processing coolant, a step of storing the used coolant used in the processing in a coolant tank, and a step of receiving the stored used coolant in an anode tank of an electrolytic treatment device. liquid At the same time, the liquid stored in the reuse tank is received in the cathode tank. liquid and a step of electrolyzing the anode and the cathode in each tank. and neutralized The electrolytic coolant liquid is sent to the reuse tank. liquid At the same time, in the cathode chamber The liquid Electrolytic treatment By doing The coolant tank As a recycled coolant sending liquid and a step of electrolytically treating the used coolant liquid. The electrolytic coolant solution thus produced is In the reuse tank By adding water Diluted This results in a diluted coolant liquid. , the above Diluted coolant but As the liquid The cathode tank liquid As well as 、 The aforementioned The liquid stored in the reuse tank To prevent spoilage of of the liquid stored in the reuse tank Some exhaust liquid The present invention is characterized by carrying out the following. [Effects of the Invention]

[0016] According to the present invention, the coolant liquid used in machining is sent to the anode tank, while the coolant liquid electrolyzed in the anode tank is reused in the cathode tank and electrolysis is carried out in each tank. As the used coolant liquid passes through the anode tank, it is neutralized and sterilized, and its pH is adjusted to be suitable for use as a machining liquid, allowing the coolant liquid to be circulated and reused. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an overall configuration diagram of a circulating electrolytic coolant production system including an electrolytic treatment device for coolant regeneration according to an embodiment; [Figure 2] FIG. 2 is a diagram showing a schematic configuration of the structure around an electrolytic treatment tank included in the electrolytic treatment device for coolant regeneration. [Figure 3] FIG. 2 is a schematic diagram showing functional blocks of a control device included in the electrolytic treatment device for coolant regeneration. [Figure 4] 3 is a flowchart showing a method for recycling coolant applied to the circulation-type electrolytic coolant production system in the embodiment. [Figure 5] FIG. 10 is a configuration diagram of a circulating electrolytic coolant production system including an electrolytic treatment device for coolant regeneration according to a first modified example. [Figure 6] FIG. 10 is an overall configuration diagram of a circulating electrolytic coolant production system including an electrolytic treatment device for coolant regeneration according to a second modification. DETAILED DESCRIPTION OF THE INVENTION

[0018] The following describes an embodiment of the present invention, which is a circulating electrolytic coolant generation system that recycles coolant used in known processing equipment that removes a portion of a workpiece or polishes the surface of the workpiece, such as in cutting or grinding using known tools. Note that the configuration other than that described in detail below can be implemented by appropriately supplementing known technologies, including those described in the patent documents listed above.

[0019] [Circulating electrolytic coolant generation system 100] 1 is an overall configuration diagram of a circulating electrolytic coolant generation system 100 according to this embodiment. That is, the circulating electrolytic coolant generation system 100 is installed in association with a processing device that processes workpieces using the above-described coolant, and is configured to include a coolant tank 10, an electrolytic processing device 20, a reuse tank 30, a water supply means 40, and a control device 60. As will be described later, the circulating electrolytic coolant generation system 100 according to this embodiment may further include at least one of an electrolysis auxiliary agent addition means 50 and a foreign matter removal filter FT.

[0020] In this embodiment, the "workpiece" may be any of various known workpieces that are preferably processed using a coolant, such as metals and ceramics. In addition, suitable "processing devices" for this embodiment include various known processing devices that process workpieces via coolant liquid, such as a grinding device that grinds the above-mentioned workpiece, a cutting device that cuts the above-mentioned workpiece, or a polishing device that polishes the above-mentioned workpiece. Furthermore, examples of the "coolant liquid" suitable for this embodiment include various known water-soluble coolant liquids and oil-based (emulsion) coolant liquids that are used in the above-mentioned processing equipment to ensure cooling, lubrication, or rust prevention of the workpiece during processing.

[0021] The coolant tank 10 is a known container that stores at least used coolant CL1 that has been used in processing a workpiece in the processing device. As shown in Fig. 1, the coolant tank 10 is preferably provided with a known pH sensor S1 that can detect the pH value of the stored coolant. In this embodiment, the coolant liquid CL1 (described later) used during processing is supplied from the processing device to the coolant liquid tank 10 via, for example, known piping and water supply means such as a pump (not shown).

[0022] The coolant tank 10 is also connected to an anode tank 22 of an electrolytic processing device 20 (described later) via a second water supply pipe 42 and a second pump P2. This allows used coolant CL1 used in processing in the processing device to be supplied into the anode tank 22 under the control of a control device 60 (described later). As shown in the figure, the circulating electrolytic coolant generation system 100 of this embodiment preferably further includes a foreign matter removal filter FT that removes foreign matter from used coolant CL1 that is delivered from the coolant tank 10 to the anode chamber 22 of the electrolytic treatment device 20. Such a foreign matter removal filter FT can be a known mesh member such as a metal mesh or a ceramic mesh, and is provided in the second water supply pipe 42. As a result, foreign matter (oil, sludge, etc.) generated during machining, such as cutting chips, is removed by the foreign matter removal filter FT, and the used coolant CL1 that has been separated into solid-liquid and oil-water is electrolyzed in the anode chamber 22.

[0023] The coolant liquid tank 10 is also connected to the cathode tank 23 of the electrolytic treatment device 20 via a third water supply pipe 43 and a third pump P3. This makes it possible to supply regenerated coolant liquid CL4 (described below) that has been electrolyzed in the electrolytic treatment device 20 into the coolant liquid tank 10. The third pump P3 is not essential and may be omitted as appropriate. In the circulating electrolytic coolant production system 100 of this embodiment, it is preferable that the pH value of the regenerated coolant CL4 electrolyzed in the cathode chamber 23 is detected by a pH sensor S1, and the electrolytic treatment device 20 is driven in accordance with the pH value detected by the pH sensor S1 installed in the coolant tank 10. The pH sensor S1 may be installed in the coolant tank 10 or in the third water supply pipe 43, for example. In one example of using the pH sensor S1 in this way, the pH value can be detected by the pH sensor S1 to control whether or not the electrolytic treatment device 20 operates. For example, if the pH value is lower than a predetermined threshold value, the electrolytic treatment device 20 may be operated, whereas if the pH value is higher than the threshold value, the electrolytic treatment device 20 may be stopped.

[0024] The electrolytic treatment device 20 is configured to include an anode chamber 22 connected to the coolant tank 10 and receiving the used coolant CL1 stored in the coolant tank 10, and a cathode chamber 23 separated from the anode chamber 22 by an ion-exchangeable diaphragm 24. More specifically, as shown in FIG. 2 , the electrolytic treatment device 20 includes an electrolytic chamber 21 in which the anode chamber 22 and the cathode chamber 23 are separated by the diaphragm 24. Of the electrolytic chambers 21, the anode chamber 22 is provided with an anode 22a configured with a known electrode, and the cathode chamber 23 is provided with a cathode 23a similarly configured with a known electrode. The anode 22a and the cathode 23a are electrically connected to a known commercial power source E, and a desired voltage is applied between these electrodes under the control of a control device 60 described below.

[0025] The electrolytic treatment device 20 of this embodiment is also connected to a water supply means 40 that supplies used coolant CL and diluted coolant CL3 to their respective destination tanks. More specifically, as can be seen from FIG. 2 , used coolant CL1 is supplied from the coolant tank 10 to the anode tank 22 of the electrolytic treatment device 20 via a second water supply pipe 42, and electrolytic coolant CL2 electrolyzed in the anode tank 22 is supplied from the anode tank 22 to the reuse tank 30 via a fourth water supply pipe 44. Meanwhile, diluted coolant CL3 is supplied from the reuse tank 30 (described later) to the cathode tank 23 of the electrolytic treatment device 20 via a first water supply pipe 41 and a first pump P1. Regenerated coolant CL4 electrolyzed in the cathode tank 23 is supplied from the cathode tank 23 to the coolant tank 10 via a third water supply pipe 43 and a third pump P3.

[0026] The reuse tank 30 is connected to the anode chamber 22 and the cathode chamber 23, respectively, and is configured to store diluted coolant CL3 produced by diluting the electrolytic coolant CL2 electrolyzed in the anode chamber 22 with water. There are no particular limitations on the reuse tank 30 as long as it performs the above function, and various known containers similar to the coolant tank 10 can be used. The reuse tank 30 may be provided with a known sensor S2 capable of detecting the temperature and conductivity of the stored liquid, and a known temperature control device (not shown), such as a heater. This allows the control device 60 to adjust the temperature of the diluted coolant CL3 stored in the reuse tank 30 to an appropriate temperature before supplying it to the anode chamber 22.

[0027] 1, the reuse tank 30 is connected to a known water source 31 via a known water supply pipe. This makes it possible to receive water from the water source 31 into the reuse tank 30 as needed. Examples of such a water source 31 include known water supplies, groundwater such as well water, and known commercially available water such as industrial water. As can be seen from the figure, the reuse tank 30 includes a discharge pipe 32 connected to a known drainage location DP, such as a river, groundwater, or sewer. A known drainage adjustment valve 33 is provided in the discharge pipe 32, allowing the control device 60 to drain the liquid in the tank via the drainage adjustment valve 33. As will be described later, in this embodiment, the used coolant liquid is neutralized by electrolysis, so the liquid in the tank can be drained to the drainage location DP without the need to treat it with chemicals or the like. Furthermore, because liquid may decay if it remains in the reuse tank 30 for a relatively long period of time, it is important to drain an appropriate amount of liquid (neutralized water) from the reuse tank 30 appropriately and at low cost as described above. An example of wastewater treatment by the control device 60 based on such a drainage adjustment valve 33 is to automatically open the drainage adjustment valve 33 to perform wastewater treatment when the conductivity of the liquid in the reuse tank 30 or the integrated value of the electrolysis treatment time in the electrolytic cell 21 exceeds a predetermined value or a predetermined time. In this case, a known water level sensor (not shown) may be provided in the reuse tank 30, and the liquid in the tank may be drained through the discharge pipe 32 until the water level in the reuse tank 30 reaches a certain level.

[0028] The water supply means 40 is configured to have the function of supplying used coolant liquid CL to the anode chamber 22 and supplying diluted coolant liquid CL3 to the cathode chamber 23. The water supply means 40 of this embodiment includes the first water supply pipe 41 and first pump P1, the second water supply pipe 42 and second pump P2, the third water supply pipe 43 and third pump P3, and the fourth water supply pipe 44 and fourth pump P4, each of which has a known structure. Note that in the water supply means 40 of this embodiment, for example, any of the pumps described above may be omitted as long as the above functions are performed. Furthermore, the fourth pump P4 is not essential and may be omitted as appropriate.

[0029] The electrolysis auxiliary agent adding means 50 is configured to have the function of adding a known electrolysis auxiliary agent to the diluted coolant CL3 sent from the reuse tank 30 to the cathode chamber 23. Such electrolysis auxiliary can be used to reduce the electrical conductivity of the solution passing through the electrolysis treatment device 20 and to produce a solution with a pH value that does not consume excessive power required for electrolysis. In addition, such an electrolysis auxiliary is preferably a component that does not produce corrosive substances. If the circulating electrolytic coolant production system 100 is equipped with an electrolysis auxiliary agent adding means 50, the diluted coolant CL3 to which the electrolysis auxiliary agent has been added is electrolyzed in the cathode chamber 23. Note that, as the electrolysis auxiliary agent in this embodiment, for example, an aqueous solution in which potassium carbonate (K2CO3) or calcium carbonate (CaCO3) is dissolved at a concentration of about 0.01 to 1.0% can be exemplified, but various known electrolysis auxiliary agents may also be used as long as they satisfy the above-mentioned conditions.

[0030] More specifically, as shown in FIG. 1, the electrolysis auxiliary agent addition means 50 includes an auxiliary agent storage tank 51 for storing the electrolysis auxiliary agent, a known pipe 52 connected to the first water supply pipe 41 to send the electrolysis auxiliary agent stored in this tank, a valve 53 having a known structure for adjusting the amount of electrolysis auxiliary agent added to the diluted coolant liquid CL3, and a fifth pump P5 having a known structure. The control device 60 preferably has a function of controlling the amount of the electrolysis auxiliary added, which enables the control device 60 to adjust the amount of the electrolysis auxiliary added to the diluted coolant CL3 depending on the number of times a voltage is applied in the electrolysis treatment device 20.

[0031] The control device 60 is configured to have the function of overall control of the operations of the electrolytic treatment device 20, the water supply means 40, etc. As shown in Fig. 3, such control device 60 can be exemplified by a known computer equipped with a known storage device MD (for example, a memory MR, a hard disk HD, or a solid state drive SSD) and a calculation device CPU. In the circulating electrolytic coolant generation system 100 of this embodiment, under the control of this control device 60, diluted coolant CL3 is electrolyzed in the cathode tank 23 and then sent to the coolant tank 10, and used coolant CL1 is electrolyzed in the anode tank 22 and then sent to the reuse tank 30.

[0032] <Functional blocks of the control device 60> Next, functions that can be executed by the control device 60 in this embodiment will be described in detail with reference to Figure 3. The functions described below are programmed by software and configured to be executable by the control device 60. Furthermore, at least a part of such programs may be executed by a known information processing server or other computer that is remotely located via a known network NW such as the Internet.

[0033] That is, the control device 60 in this embodiment is configured to include a pH detection unit 61 , an applied voltage determination unit 62 , an electrolytic cell drive unit 63 , an electrolysis auxiliary agent addition control unit 64 , and a pump control unit 65 .

[0034] The pH detection unit 61 has a function of detecting the pH value in the coolant tank 10 via the above-mentioned pH sensor S1. When the pH value detected by the pH detection unit 61 falls below a predetermined value, for example, the control device 60 controls the supply of regenerated coolant CL4 from the cathode chamber 23 to the coolant tank 10 via the third water supply pipe 43 and the third pump P3.

[0035] This allows the pH value in the coolant tank 10 to be adjusted to an appropriate value when it becomes acidic and drops to a level at which bacterial growth becomes a problem. As an example, in this embodiment, when the pH value detected by the pH detection unit 61 falls to 10.0 or lower, the control device 60 controls the supply of regenerated coolant from the cathode chamber 23 into the coolant tank 10.

[0036] The applied voltage determination unit 62 has the function of determining the voltage to be applied between the anode 22a and the cathode 23a of the electrolytic cell 21. In addition to the above-mentioned voltages, the applied voltage determination unit 62 may also determine the current value between the anode E2 and the cathode E1. As an example, the voltage to be applied between the anode 22a and the cathode 23a1 is preferably about 8 V to 45 V, and the current value is preferably controlled within a range of about 5 A to 100 A, although these can be adjusted appropriately depending on the scale of the apparatus.

[0037] The electrolytic cell drive unit 63 has the function of applying a voltage between the anode 22a and the cathode 23a of the electrolytic cell 21 via the commercial power source E for a predetermined time based on the voltage determined by the applied voltage determination unit 62, etc., after the used coolant liquid CL1 and the diluted coolant liquid CL3 are supplied to the anode cell 22 and the cathode cell 23, respectively, via a valve not shown and the water supply means 40 described above.

[0038] The electrolysis auxiliary agent addition control unit 64 has a function of adding the above-described electrolysis auxiliary agent as needed to the diluted coolant CL3 flowing through the first water supply pipe 41. As an example, the electrolysis auxiliary agent addition control unit 64 can execute control to add a relatively large amount of electrolysis auxiliary agent to the diluted coolant CL3 when the electrolysis treatment device 20 first starts electrolysis (e.g., the first electrolysis treatment), and to add a relatively small amount of electrolysis auxiliary agent to the diluted coolant CL3 from the next time onwards (e.g., the second or subsequent electrolysis treatments). As a result, during the first electrolysis treatment, the reuse tank 30 is filled almost entirely with water supplied from the water source 31, making it possible to perform appropriate electrolysis treatment using the diluted coolant CL3 to which a relatively large amount of electrolysis auxiliary agent has been added.

[0039] The electrolysis auxiliary agent addition control unit 64 can determine an appropriate amount of electrolysis additive to be added by calculating the conductivity of the solution flowing into the electrolytic cell 21 using a known method, based on the conductivity and temperature of the liquid in the reuse tank 30 measured by the sensor S2 installed in the reuse tank 30. The electrolysis auxiliary agent addition control unit 64 may also have a function to automatically adjust the amount of electrolysis additive to be added depending on the voltage value and current value of the electrolytic cell 21 that is actually operating.

[0040] The pump control unit 65 has a function of controlling the drive of each of the first pump P1, second pump P2, third pump P3, fourth pump P4, and fifth pump P5 so that the above-mentioned coolant recycling process is properly performed. As mentioned above, the third pump P3 and the fourth pump P4 may be omitted as appropriate.

[0041] The control device 60 of this embodiment is configured to be capable of communicating with various sensors S, including the pH sensor S1 described above. The control device 60 may also monitor the pH value in the coolant tank 10 and the operating status of the electrolytic treatment device 20 via a known display device DD, such as a liquid crystal display panel. The control device 60 may also be connected to a known network NET, such as the Internet, via a known communication device CT, such as a modem.

[0042] [Electrolytic treatment equipment for coolant regeneration] The electrolytic treatment device for coolant regeneration of this embodiment can be incorporated as part of the circulating electrolytic coolant production system 100 described above. More specifically, the electrolytic treatment device for coolant regeneration in this embodiment includes the above-mentioned ion-exchangeable diaphragm 24, the anode chamber 22 that receives used coolant liquid CL1 stored in the coolant liquid tank 10, the cathode chamber 23 that is separated from the anode chamber 22 by the diaphragm 24 and receives diluted coolant liquid CL3 sent from the reuse tank 30, and a control device 60 that applies a predetermined voltage between the anode 22a installed in the anode chamber 22 and the cathode 23a installed in the cathode chamber 23 via a commercial power source E. The electrolytic treatment device for coolant regeneration of this embodiment may be configured to further include at least a part of the water supply means 40 described above.

[0043] <How to recycle coolant for processing equipment> Next, with reference to FIG. 4, a method for reusing used coolant stored in the coolant tank 10 by neutralizing and sterilizing it while adjusting its pH to an appropriate value using the electrolytic treatment device 20 of this embodiment will be described.

[0044] First, in step 1, a workpiece is machined using the machining coolant in the machining device, and the used coolant is stored in the coolant tank 10. Then, the pH detection unit 61 of the control device 60 executes control to measure the pH value in the coolant tank 10 via the pH sensor S1.

[0045] Next, in step 2, the control device 60 determines whether the pH value measured in step 1 is equal to or lower than a predetermined reference value (for example, pH 8.0). If the pH value is equal to or lower than the reference value in step 2, the process proceeds to step 3, whereas if the pH value is not equal to or lower than the reference value, the process returns to step 1 and continues detecting the pH value.

[0046] If the pH value becomes equal to or lower than the reference value in step 2, then in the following step 3, the voltage to be applied between the anode 22a and the cathode 23a of the electrolytic cell 21 is determined by the applied voltage determination unit 62 described above.

[0047] Next, in step 4, the used coolant CL1 is injected into the anode chamber 22 via the water supply means 40, and the diluted coolant CL3 is injected into the cathode chamber 23. At this time, a predetermined amount of electrolysis auxiliary may be added to the diluted coolant CL3 by the electrolysis auxiliary adding means 50. Thereafter, electrolysis is performed in the electrolysis chamber 21 based on the applied voltage determined in step 3. As described above, in the first electrolysis in this embodiment, the diluted coolant CL3 delivered from the reuse tank 30 is initially almost entirely tap water, so a relatively large amount of electrolysis auxiliary is added. On the other hand, in the second and subsequent electrolysis processes, for example, the electrolyzed electrolytic coolant CL2 is received in the reuse tank 30 and diluted with tap water, so a relatively small amount of electrolysis auxiliary is added compared to the first electrolysis.

[0048] Next, in step 5, the electrolytic coolant liquid CL2 electrolyzed in the anode cell 22 of the electrolytic cell 21 is sent to the reuse tank 30 via the fourth water supply pipe 44, and the recycled coolant liquid CL4 as alkaline water electrolyzed in the cathode cell 23 is sent to the coolant liquid tank 10.

[0049] In this way, the used coolant CL1 is first poured into the anode tank 22 of the electrolytic treatment device 20, electrolyzed in the anode tank to neutralize the pH value from alkaline to near neutral, then poured into the cathode tank 23 of the electrolytic treatment device 20 via the reuse tank 30, electrolyzed again in the cathode tank, and finally returned to the coolant tank 10. That is, in this embodiment, the used coolant as described above is returned through the electrolytic treatment device, thereby performing a regeneration and circulation process of the coolant.

[0050] Next, in step 6, it is determined whether the pH value in the coolant tank 10 is equal to or lower than a predetermined completion reference value. For example, the completion reference value may be set to a value close to the optimum pH value for coolant typically used in machining equipment. While the completion reference value is set to pH 9.0 in this embodiment, the completion reference value is not limited to this example, and other pH values ​​may be used as the reference.

[0051] If the pH value in the coolant tank 10 does not reach the completion reference value in step 6, the process returns to step 4, where new liquid to be treated in the electrolytic treatment device 20 is poured in, and the regeneration and circulation process of the coolant via the electrolytic treatment is repeated. On the other hand, if the pH value in the coolant tank 10 reaches the completion reference value in step 6, the process proceeds to the following step 7.

[0052] In the next step 7, it is determined whether or not the processing of the workpiece by the processing device has been completed. If the processing of the workpiece has not yet been completed, the process returns to step 1 and the above-described processing is repeated, whereas if the processing of the workpiece has been completed, the process proceeds to step 8.

[0053] In the following step 8, various well-known equipment shutdown processes are carried out, such as storing the tools used to process the workpiece and retracting the processing stage, and the method for recycling coolant liquid for processing equipment according to this embodiment is also completed.

[0054] As described above, the method for recycling machining coolant according to this embodiment includes the steps of: machining a workpiece using machining coolant; storing used coolant CL1 used in machining in coolant tank 10; receiving the stored used coolant CL1 in anode tank 22 of electrolytic treatment device 20 and receiving the liquid stored in reuse tank 30 in cathode tank 23, and performing electrolysis in each tank; and supplying electrolytic coolant CL2 electrolyzed in anode tank 22 to reuse tank 30 and supplying alkaline water electrolyzed in cathode tank 23 as recycled coolant CL4 to coolant tank 10. In the method for recycling machining coolant according to this embodiment, the used coolant CL1 is electrolyzed and diluted with liquid (such as tap water) from water source 31 in reuse tank 30, and the diluted used coolant (diluted coolant CL3) is supplied to the cathode tank and electrolyzed.

[0055] According to the circulating electrolytic coolant generation system 100 including the electrolytic treatment device for coolant regeneration in the present embodiment described above, the coolant after use is electrolyzed in the anode cell of the electrolytic treatment device to neutralize and sterilize it, and then electrolyzed again in the cathode cell to adjust the pH value to an appropriate value for machining coolant, and then returned to the coolant tank, allowing the machining coolant to be recycled efficiently and without waste.

[0056] Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

[0057] For example, in the above embodiment, the circulation regeneration process of the coolant liquid in the electrolytic treatment device 20 was performed according to the pH value in the coolant liquid tank 10, but this is not limited to this form. For example, the circulation regeneration process of the coolant liquid may be performed periodically without being triggered by the pH value, for example, after a certain period of time has elapsed.

[0058] Furthermore, in the above-described embodiment, if the polarity of the voltage applied to the electrolytic cell 21 is not changed, minerals will gradually adhere to the cathode side, and if this is left for a long period of time, there is a possibility that water will eventually stop flowing through the electrolytic cell 21. Therefore, as a countermeasure, the control device 60 may perform control to reverse the polarity of the voltage applied to the electrolytic cell 21. A circulating electrolytic coolant generation system 110 based on such Modification 1 is shown in Fig. 5. In Fig. 5, the explanation will be focused on the parts that are different from the above-described embodiment, and the explanation of the same components as the above-described embodiment will be omitted or the same reference numerals will be used (the same applies to Modification 2).

[0059] <Variation 1> As shown in Fig. 5, the control device 60 in this modification periodically switches the cathode and anode in the electrolytic cell 21. As a specific device configuration, as shown in the figure, three three-way valves V1 to V4, a second water supply pipe 42, a fourth water supply pipe 44, and switchable flow paths 45 (first switching flow path 45a to sixth switching flow path 45f) are applied to the electrolytic cell 21.

[0060] That is, as shown in the figure, a first three-way valve V1 is provided on a second water supply pipe 42 connecting the coolant liquid tank 10 to one of the electrolytic baths 21 (the bath located at the top in the figure), and a second switching flow path 45b is connected from the reuse tank 30 between the first three-way valve V1 and the electrolytic bath 21 via a second three-way valve V2. One end of a third switching flow path 45c is connected to the second three-way valve V2 (side A in the figure) on the second switching flow path 45b connected to the reuse tank 30, and the other end of the third switching flow path 45c is connected to the other bath of the electrolytic bath 21. One end of a first switching flow path 45a is connected to the first three-way valve V1 (side B in the figure), and the other end of the first switching flow path 45a is connected to the third switching flow path 45c.

[0061] Furthermore, a water supply path is established from one of the electrolytic baths 21 to the reuse tank 30 via a fourth water supply pipe 44, and this fourth water supply pipe 44 is provided with a third three-way valve V3. One end of a fourth switching flow path 45d is connected to the other of the electrolytic baths 21. The other end of the fourth switching flow path 45d is connected to the fourth water supply pipe 44 between the third three-way valve V3 and the reuse tank 30. A fourth three-way valve V4 is provided on this fourth switching flow path 45d, and one end of a fifth switching flow path 45e is connected to this fourth three-way valve V4 (side A in the figure), and the other end is connected to the coolant liquid tank 10. Furthermore, one end of a sixth switching flow path 45f is connected to the third three-way valve V3 (side B in the figure), and the other end is connected to the fifth switching flow path 45e between the fourth three-way valve V4 and the coolant liquid tank 10.

[0062] For example, when one of the electrolytic baths 21 (upper side in the figure) is the positive electrode, the control device 60 controls the valves of the first three-way valve V1 to the fourth three-way valve V4 so that water enters through the C side and flows out through the A side. On the other hand, when the other of the electrolytic baths 21 (lower side in the figure) is the positive electrode, the control device 60 controls the valves of the first three-way valve V1 to the fourth three-way valve V4 so that water enters through the C side and flows out through the B side. This makes it possible to appropriately switch the piping configuration for water inflow and outflow of the electrolytic bath 21 and to switch the inlet and outlet channels of the liquid in response to polarity reversal of the electrolytic bath 21 via the multiple three-way valves.

[0063] The circulating electrolytic coolant generation system in the modified example described above includes a three-way valve and a switching flow path that switches the inlet and outlet flow paths to the electrolytic cell in response to polarity reversal (switching between anode and cathode) of the electrolytic cell. This makes it possible to solve the above-mentioned problem caused by minerals adhering to the cathode side of the electrolytic cell 21.

[0064] <Variation 2> Next, a circulating electrolytic coolant production system 120 including an electrolytic treatment device for coolant regeneration according to Modification 2 will be described with reference to FIG. In the above-described embodiment and variant 1, the coolant liquid after use is neutralized by electrolytic treatment, so that it is possible to discharge the liquid in the reuse tank 30 to the discharge location DP without essentially having to treat it with chemicals or the like.

[0065] In contrast, the circulating electrolytic coolant liquid generation system 120 of this modified example 2 is based on the premise that the water is discharged to the discharge location DP without the need for treatment with the above-mentioned chemicals, etc., and is mainly characterized in that, compared to the above-mentioned embodiment, it further includes a water-soluble cutting fluid addition means 70 that adds a predetermined amount of water-soluble cutting fluid to the coolant liquid tank 10.

[0066] That is, as shown in Figure 6, the water-soluble cutting fluid adding means 70 in this modified example 2 is composed of a water-soluble cutting fluid tank 71 that stores the water-soluble cutting fluid (coolant fluid) concentrate used in processing in the processing device described above, a well-known discharge pump 72 for discharging a predetermined amount of water-soluble cutting fluid from the water-soluble cutting fluid tank 71, and a concentrate supply pipe 73 that is connected to the water-soluble cutting fluid tank 71 and supplies the water-soluble cutting fluid to the coolant fluid tank 10 via the discharge pump 72.

[0067] In this modified example 2, the undiluted water-soluble cutting fluid is used as the water-soluble cutting fluid to be added to the coolant liquid tank 10, but this is not limited to this form, and a diluted water-soluble cutting fluid diluted with water, for example, may also be used.

[0068] As an example, the control device 60 may add a predetermined amount of water-soluble cutting liquid to the coolant liquid tank 10 via the water-soluble cutting liquid adding means 70, for example, when (a) the liquid in the above-mentioned reuse tank 30 is drained through the discharge pipe 32, or (b) the processing process has been performed for a predetermined period of time (for example, several to several tens of hours) in the above-mentioned processing device. The amount of the water-soluble cutting fluid to be added can be adjusted as appropriate depending on the components of the water-soluble cutting fluid to be added and the processing purpose of the processing equipment.

[0069] The circulating electrolytic coolant generation system 120 according to the second modification described above not only achieves the effects of the above-described embodiment, but also makes it possible to appropriately replenish coolant (such as cutting fluid) when its quality or quantity becomes insufficient due to wastewater treatment or processing. This makes it possible to circulate and reuse coolant while maintaining a high level of quality in the processing equipment. [Industrial Applicability]

[0070] As described above, the circulating electrolytic coolant production system of the present invention is suitable for purification equipment that can electrolyze used coolant used in processing equipment with high efficiency and without waste, and reuse it. [Explanation of symbols]

[0071] 10 Coolant tank 20 Electrolytic treatment equipment 30 Reuse Tank 40 Water conveyance means 50 Means for adding electrolytic auxiliary agent 60 Control device 70 Coolant adding means 100, 110, 120 Circulating electrolytic coolant generation system

Claims

1. a coolant tank for storing used coolant used in processing the workpiece; an electrolytic treatment device including: an anode chamber connected to the coolant tank for receiving used coolant stored in the coolant tank; and a cathode chamber separated from the anode chamber by an ion-exchangeable diaphragm; a reuse tank connected to each of the anode tank and the cathode tank, for storing a diluted coolant liquid produced by diluting the electrolytic coolant liquid electrolyzed in the anode tank with water; a liquid delivery means for delivering the used coolant to the anode chamber and the diluted coolant to the cathode chamber, The diluted coolant is electrolyzed in the cathode tank and then sent to the coolant tank, and the used coolant is electrolyzed in the anode tank and then sent to the reuse tank. A circulating electrolytic coolant generating system characterized by:

2. an electrolysis auxiliary agent adding means for adding an electrolysis auxiliary agent to the diluted coolant liquid sent from the reuse tank to the cathode tank, The diluted coolant solution to which the electrolysis auxiliary agent has been added is subjected to electrolysis in the cathode cell. The circulating electrolytic coolant generating system according to claim 1 .

3. a control device for controlling the operation of the electrolytic treatment device and the amount of the electrolytic auxiliary agent added; the control device adjusts the amount of the electrolysis auxiliary agent added to the diluted coolant solution depending on the number of times a voltage is applied in the electrolysis treatment device. The circulating electrolytic coolant generating system according to claim 2 .

4. The coolant tank further includes a foreign matter removal filter that performs solid-liquid separation and oil-water separation on the used coolant liquid sent from the coolant liquid tank to the anode tank to remove foreign matter, The used coolant from which the foreign matter has been removed is subjected to electrolytic treatment in the anode tank. The circulating electrolytic coolant generating system according to any one of claims 1 to 3.

5. An electrolytic treatment device for coolant regeneration used in the circulating electrolytic coolant generation system according to any one of claims 1 to 4, an ion-exchangeable diaphragm; an anode tank that receives the used coolant stored in the coolant tank; a cathode chamber separated from the anode chamber by the diaphragm and configured to receive the diluted coolant liquid sent from the reuse tank; a control device that applies a predetermined voltage between an anode installed in the anode chamber and a cathode installed in the cathode chamber via a power source; An electrolytic treatment device for regenerating coolant liquid, comprising:

6. machining a workpiece using a machining coolant; storing the used coolant liquid in a coolant liquid tank after the processing; a step of receiving the stored used coolant liquid in an anode tank of an electrolytic treatment device and receiving the liquid stored in the reuse tank in a cathode tank, and performing electrolytic treatment in each tank; The electrolytic coolant liquid that has been electrolyzed and neutralized in the anode tank is sent to the reuse tank, and the liquid is electrolyzed in the cathode tank to be sent to the coolant liquid tank as a regenerated coolant liquid, The electrolytic coolant produced by electrolyzing the used coolant is diluted by adding water in the reuse tank to form a diluted coolant, The diluted coolant liquid is sent to the cathode tank as the liquid, and a portion of the liquid stored in the reuse tank is drained in order to prevent spoilage of the liquid stored in the reuse tank. A method for recycling coolant liquid.

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