JP4938714B2 - Electrolytic cleaning apparatus and electrolytic cleaning method - Google Patents

Description

  The present invention relates to an electrolytic cleaning apparatus and an electrolytic cleaning method, and more specifically, without corroding or dissolving metal parts such as precision molds made of Fe, steel, stainless steel, Ni, Ti, rare metals, The present invention relates to an electrolytic cleaning apparatus and an electrolytic cleaning method capable of suitably removing adhered dirt such as resin, glass, rubber, abrasive, and smut, metal oxides such as rust and oxide film, and dirt such as discoloration.

  If resin molding is repeated using a mold at high temperature and high pressure, the gas generated by the thermal decomposition of the resin and additives will burn into the mold, or burnt resin may adhere, and in some cases, corrosion will occur. In some cases, an oxide film containing an active substance is formed. If this is left without proper maintenance, the mold may be corroded and damaged. Conventionally, metal parts such as molds with such dirt attached are often maintained by a method of manually polishing and removing them or by ultrasonic cleaning. However, these methods are troublesome, and the stains with strong binding force cannot be removed sufficiently.

  Therefore, as a cleaning method that can effectively remove such a stain having a strong binding force, a cleaning method using electrolysis has been proposed (for example, Patent Document 1, Patent Document 2, and Patent Document 3). .

  The basic principle of electrolytic cleaning is to push up the dirt with gas generated when the electrolytic cleaning solution is electrolyzed and peel it off. In general, additives such as chelating agents are added to the electrolytic cleaning solution, and these additives coordinate and block the metal ions dissolved in the electrolytic cleaning solution, so that the metal ions are cleaned. This prevents damage such as burning and discoloration.

  However, these additives are gradually decomposed and consumed by the electrolytic reaction, and when the cleaning liquid components are decomposed and consumed more than a certain amount, the function of sequestering metal ions as described above is rapidly lost, and cleaning is performed. The object becomes damaged. Therefore, the period from the state before use to this state is the life of the electrolytic cleaning solution. It is known that the life of the electrolytic cleaning solution and the energization amount are in an inversely proportional relationship according to Faraday's law of electrolysis (for example, Non-Patent Document 1). That is, if the energization amount is increased, the life is shortened, and conversely if the energization amount is decreased, the life is lengthened.

JP-A-11-128853 JP 7-214570 A JP-A-9-164533 “Plastics” Japan Plastics Federation, 58 (December 2007), p55-57

  Until now, it has been considered that the cleaning effect and the energization amount are in a proportional relationship. Therefore, in order to enhance the cleaning effect, a method of increasing the energization amount has been adopted, and as a result, the life has been inevitably shortened.

  However, since the electrolytic cleaning liquid is generally expensive and has a high proportion of the running cost, there is a problem that the running cost becomes high if the life is short. Also, it is not preferable to frequently discard the used electrolytic cleaning liquid because the environmental load is increased by increasing the amount of waste liquid. Furthermore, if the replacement frequency is high, there is a problem that the working efficiency of the entire electrolytic cleaning is lowered.

  Then, an object of this invention is to provide the electrolytic cleaning apparatus and the electrolytic cleaning method which can maintain the lifetime of an electrolytic cleaning liquid long, without reducing a cleaning effect.

The electrolytic cleaning apparatus according to the present invention is an electrolytic cleaning apparatus for electrolytically cleaning an object to be cleaned by immersing an anode and a cathode holding an object to be cleaned in an electrolytic cleaning liquid and passing an electric current between the anode and the cathode, A power supply for supplying power to the anode and the cathode, the anode including a plurality of anode portions that can be energized at different current values with respect to the cathode, and the power supply includes a portion of the anode portions of the plurality of anode portions. current value of the cathode in, characterized in Rukoto switch alternately between high state and low state than the current value of the cathode of the other anode portion.

The electrolytic cleaning method according to the present invention is an electrolytic cleaning method in which an anode and a cathode holding an object to be cleaned are immersed in an electrolytic cleaning solution, and an electric current is passed between the anode and the cathode to electrolytically clean the object to be cleaned. Te, the anode comprises a plurality of anode unit capable energized at different current values with respect to the cathode, the current value of the cathode in some of the anode portion of the plurality of anode portions, in other anode portion Control is performed so that the current value with respect to the cathode is switched alternately between a large state and a small state.

According to the electrolytic cleaning apparatus and the electrolytic cleaning method configured as described above, while maintaining the same cleaning effect as in the case of the conventional electrolytic cleaning apparatus and the electrolytic cleaning method in which current is always supplied uniformly between the anode and the cathode, The life of the cleaning liquid can be maintained for a long time. Alternatively, more objects to be cleaned can be cleaned using the same amount of electrolytic cleaning liquid. One of the reasons for this effect is that the amount of current (current value) between the specific anode and cathode always changes, and the state of gas generation in the object to be cleaned held by the cathode always changes. Therefore, it is conceivable that a cleaning action such as a peeling action can be effectively applied to the dirt adhering to the object to be cleaned. In addition, since the multiple anode parts are located at different positions, if the anode part with the largest amount of current (current value) changes over time, the direction in which the cleaning action is applied will change over time, and the cleaning action will be cleaned. One of the reasons is that it can be effectively added to dirt attached to the object. In addition, since the life of the electrolytic cleaning solution is inversely proportional to the amount of energization, the current always flows uniformly between the anode and the cathode (that is, all the anode parts arranged are always energized constantly) compared to the conventional electrolytic cleaning Therefore, the amount of energization can be suppressed, and the life of the electrolytic cleaning solution can be extended accordingly.

In the above configuration, it is preferable that the current value is controlled by a voltage applied by the power source between the anode portion and the cathode.

In this way, since the energization amount (current value) can be controlled by controlling the voltage, the energization amount (current value) can be easily controlled.

In the above configuration, the power source includes a state in which a voltage applied between the part of the anode and the cathode is higher than a voltage applied between the other part of the anode and the cathode, and the part of the anode. Rukoto example replacement disconnect the high state is preferred than the voltage the voltage applied between different anode portions and the cathode is applied between the anode part and cathode other than the anode portion of the said further and parts.

  In this way, high voltages are applied at different timings between some anode parts and cathodes and between different anode parts and cathodes, so that the cleaning action such as the peeling action is applied to the dirt adhering to the object to be cleaned. It can be added more effectively.

Specifically, the anode is composed of two anode parts, and the power source is in a state where a voltage is applied only between one anode part and the cathode, and a voltage is applied only between the other anode part and the cathode. switching Operation exchange e Rukoto the condition being preferred.

In this way, a voltage is always applied only to any one of the anodes and the cathodes, so that the energization amount (current value) per unit time can be suitably reduced.

  In addition, it is preferable that a voltage having a constant magnitude is alternately applied between the anode portions and the cathode every predetermined time.

  In addition, as the electrolytic cleaning method, a configuration in which a voltage having a constant magnitude is alternately applied between the anode portions and the cathode every predetermined time is preferable.

  In this way, since the total energization amount between each anode part and the cathode becomes the same, the object to be cleaned can be electrolytically cleaned uniformly throughout.

  The anode is preferably formed using Fe, Pt, Pd, Ir, Ru, or an alloy thereof.

  Alternatively, the anode may be formed by coating an anode body made of Ti with Pt, Pd, Ir, Ru, or an alloy thereof.

  The electrolytic cleaning apparatus preferably includes an ultrasonic generator that ultrasonically vibrates the electrolytic cleaning liquid.

  In this way, the electrolytic cleaning liquid can vibrate ultrasonically, thereby facilitating the removal of dirt attached to the object to be cleaned.

  The electrolytic cleaning solution contains at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and sodium citrate as an electrolyte, and carboxy as a chelating agent. Contains a chelating agent that coordinates a metal ion with a rate group (COO-) and a nitrogen (N) atom, and a gluconate, and as a surfactant, a neutral surfactant, an amphoteric surfactant, an anionic interface A configuration containing at least one of the activators is preferable.

  Further, the electrolytic cleaning method includes replenishing a replenisher in the electrolytic cleaning solution during the electrolytic cleaning, and the replenisher includes sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, carbonate as an electrolyte. A chelating agent containing at least one of sodium hydrogen, potassium hydrogen carbonate, sodium citrate, and a metal ion coordinated with a carboxylate group (COO-) and a nitrogen (N) atom as a chelating agent; and gluconic acid A structure containing a salt is preferred.

  As described above, according to the present invention, the life of the electrolytic cleaning solution can be maintained long without reducing the cleaning effect. Therefore, since the electrolytic cleaning liquid can be used for a long time, the running cost can be reduced, and the frequency of waste liquid generation can be reduced to reduce the burden on the environment.

  Embodiments of an electrolytic cleaning apparatus and an electrolytic cleaning method according to the present invention will be described below with reference to the drawings.

  As shown in FIGS. 1 and 2, the electrolytic cleaning apparatus 1 according to the first embodiment immerses the anode 10 and the cathode 20 holding the object to be cleaned M in an electrolytic cleaning solution, and between the anode 10 and the cathode 20. The cleaning object M is electrolytically cleaned by passing an electric current. In the following, first, a schematic description will be given of the configuration of the electrolytic cleaning apparatus 1 itself. The electrolytic cleaning apparatus 1 includes, in addition to the anode 10 and the cathode 20, a housing 2, a cleaning tank 3 disposed on the top of the housing 2, and containing an electrolytic cleaning liquid, and electrodes (anode 10 and cathode 20). A power supply 4 for supplying power is provided inside the housing 2.

  The anode 10 is provided such that a metal discharge portion 12a, which will be described later, is located inside the cleaning tank 3, and the discharge portion 12a is immersed in an electrolytic cleaning solution during electrolytic cleaning. Specifically, as shown in FIG. 2, the anode 10 is suspended from the opening at the upper end of the cleaning tank 3. The anode 10 includes a plurality (for example, two) of anode portions 11 and 11 that can separately apply different voltages. As a result, the anode 10 can be energized with different energization amounts with respect to the cathode 20. (In the following, when it is necessary to distinguish between the two anode portions 11, they are described with the suffixes A and B, such as anode portions 11A and 11B.)

  Each anode portion 11 is arranged such that the discharge portion 12a is positioned on a plane along a horizontal plane. Specifically, the anode body 12 having the discharge portion 12a and a support 13 that supports the anode body 12 are provided. And is configured. Further, the anode part 11 is a member as shown in FIG. 3A, and has a plurality of anode bodies 12 (for example, 4 to 10 pieces). As the anode body 12, a disk-shaped metal (diameter 36 mm) having a circular plane portion is used. The anode bodies 12 are provided in pairs. Further, as shown in FIG. 3B, the anode body 12 is covered with an insulator 12b such as a resin on the outer surface thereof except for the discharge portion 12a.

  The anode body 12 is configured such that the height position relative to the support body 13 can be adjusted, and is fixed at an arbitrary height direction position. Moreover, the anode body 12 is arrange | positioned so that the space | interval of the metal discharge part 12a and the upper end surface of the cleaning target M may be 20-50 mm, and 30 mm is especially preferable. In this way, the electrolytic cleaning can be suitably performed without causing damage such as burning or discoloration to the cleaning object M.

  Further, the anode body 12 of the anode 10 covers a portion of the cathode 20 on which the object to be cleaned M is placed over a wide range as compared with a conventional electrolytic cleaning apparatus (see, for example, FIGS. 5 and 7). Placed so as to cover. Specifically, as shown in FIG. 1, the anode body 12 is provided so as to cover at least a region slightly narrower than the area of the cathode 20. That is, the anode body 12 is disposed so as to cover the entire surface to be cleaned. For example, the virtual outline L1 of the anode 10 defined by the plurality of anode bodies 12, 12,... And the outline L2 of the cathode 20 defined by the portion on which the cleaning object M is placed are two-dimensionally represented. In a state where they are superposed on each other (viewed from above), the gap region S formed between the two outlines is set to such a size that the anode body 12 cannot be disposed. That is, the width of the gap region S is formed to be smaller than the anode body 12.

  The anode 10 (that is, the anode body 12) is formed using Fe. Since Fe is inexpensive, the cost of the electrolytic cleaning apparatus 1 can be reduced. However, since accumulation of metal ions in the electrolytic cleaning liquid increases the possibility of adsorption to the cleaning object M by changing to oxides or the like, from the viewpoint of preventing this, the anode 10 (that is, the anode body 12) is , Pt, Pd, Ir, Ru, or the like, or a platinum group metal having a low ionization tendency, or an alloy thereof is preferably used. Further, the anode body 12 may be formed by covering an anode body made of Ti with Pt, Pd, Ir, Ru, or an alloy thereof. In this way, the amount of expensive platinum group metal used can be reduced, which is economical.

  As shown in FIG. 2, the cathode 20 includes a support member 21 that supports the cleaning object M in a state of being electrically connected to the cleaning object M, and a suspension member 22 that suspends the support member 21. It is prepared for. The support member 21 has a metal conductive portion 21 a configured to come into contact with the cleaning object M. Specifically, the support member 21 is provided as a tray made of metal such as stainless steel. However, the cathode is not limited to those described above, and may be provided as a metal cage such as stainless steel. The support member 21 is formed with a space that communicates between both surfaces of the support member 21. In this way, since the electrolytic cleaning liquid can flow through the space formed in the support member 21, the cleaning liquid decomposed by electrolysis does not accumulate in the gap with the object to be cleaned M, and is always fresh. Therefore, it is possible to perform cleaning suitably without causing a problem that the decomposed cleaning liquid component is burned onto the object to be cleaned. Specifically, the support member 21 is formed using a so-called punching metal in which a plurality of punch holes are formed. Note that the upper end portion of the support member 21 is edged by an insulator 21b such as resin. Moreover, the suspension member 22 is covered with an insulator 22c such as a resin except for the connection portion 22a with the support member 21 and the connection portion 22b with the power source 4.

  In addition to the electrolytic cleaning, the electrolytic cleaning apparatus 1 includes an ultrasonic generator (not shown) for ultrasonically cleaning the object to be cleaned by ultrasonically vibrating the electrolytic cleaning liquid. The ultrasonic generator is provided in the lower part of the cleaning tank 3. The ultrasonic cleaning can be performed simultaneously with the electrolytic cleaning or alternately, but is preferably performed simultaneously with the electrolytic cleaning.

  In this way, it is possible to promote the peeling of dirt adhered to the cleaning object M by ultrasonic vibration of the electrolytic cleaning liquid. Specifically, cavitation is generated by ultrasonic vibration, which promotes peeling of dirt and activates the electrolytic reaction. Therefore, a high cleaning effect can be exerted even on a portion not facing the anode body 12 or a recessed portion.

  Further, the electrolytic cleaning apparatus 1 preferably includes a heating device (not shown) for heating the electrolytic cleaning liquid. In addition, as for the liquid temperature which performs electrolytic cleaning, 20-70 degreeC is preferable, In this case, it can wash | clean suitably, without the washing | cleaning target object M producing a burn or discoloration. Furthermore, when the liquid temperature is 50 to 60 ° C., the object to be cleaned M is also damaged by mold stains having relatively strong bonds such as metal oxide film, rust, resin deposits, and gas burn. And can be cleaned most efficiently in a short time.

  Further, the electrolytic cleaning apparatus 1 includes a circulation mechanism (not shown) that discharges the electrolytic cleaning liquid from the cleaning tank 3, removes impurities, and throws the electrolytic cleaning liquid into the cleaning tank 3 again. Here, the circulation mechanism will be specifically described. The cleaning tank 3 is configured such that the electrolytic cleaning liquid is supplied from the bottom, and when the cleaning tank 3 is full, the electrolytic cleaning liquid overflows from a discharge portion provided at a predetermined height. Yes. When electrolytic cleaning is performed, foreign substances such as deposits and bubbles peeled off from the cleaning object M are generated. By overflowing the electrolytic cleaning liquid, these foreign substances and bubbles are also washed with the electrolytic cleaning liquid in the cleaning tank 3. Discharged from. The discharged electrolytic cleaning liquid is purified by a known method such as filtration using a filter, and the cleaned electrolytic cleaning liquid is supplied to the cleaning tank 3 again.

  The cleaning object M to be cleaned by the electrolytic cleaning apparatus 1 is, for example, a gold for injection molding a light guide plate or a sheet-like optical lens of a flat panel display, an ultra-small and precise camera lens of a mobile phone, a vehicle reflector, or the like. It is a type.

  As the electrolytic cleaning solution, one containing an electrolyte, a chelating agent, and a surfactant is used. The electrolyte preferably contains at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and sodium citrate. As the chelating agent, those containing a chelating agent that coordinates a metal ion with a carboxylate group (COO-) and a nitrogen (N) atom, and a gluconate are preferable. As the surfactant, those containing at least one of a neutral surfactant, an amphoteric surfactant and an anionic surfactant are preferable, and an amphoteric surfactant is particularly preferable. In addition, the electrolytic cleaning solution is an alkaline aqueous solution having a pH of 8 to 14, and in this range, the higher the pH value, the higher the cleaning effect. Further, if cleaning is performed in this pH range, corrosion of the cleaning object made of Fe, steel, stainless steel, Ni, Ti, or rare metals can be ignored.

  In the above electrolytic cleaning solution, the chelating agent coordinates and blocks the metal ions dissolved in the electrolytic cleaning solution, so that it is possible to suitably prevent discoloration of the cleaning object derived from the metal ions. In addition, since the surfactant reduces the surface tension of the electrolytic cleaning liquid, it can increase the permeability with respect to the gaps in the dirt and enhance the cleaning effect. Moreover, since bubbles are generated on the surface of the electrolytic cleaning liquid by the surfactant, it is possible to suitably prevent the alkaline mist generated when the gas generated by the electrolytic cleaning is repelled on the liquid surface.

  Furthermore, if the electrolytic cleaning is performed for a long time, the amount of the liquid decreases due to the evaporation of the electrolytic cleaning liquid or the electrolysis of water. Therefore, the replenisher is appropriately replenished in order to maintain the liquid amount at the start of the electrolytic cleaning. The replenisher may be water, but preferably contains an electrolyte, a chelating agent, and a gluconate, and more preferably contains a surfactant. As with the above-described electrolytic cleaning solution, the electrolyte contains at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, and sodium citrate. preferable. The chelating agent preferably contains a chelating agent that coordinates a metal ion with a carboxylate group (COO-) and a nitrogen (N) atom. As the surfactant, those containing at least one of a neutral surfactant, an amphoteric surfactant and an anionic surfactant are preferable, and an amphoteric surfactant is particularly preferable.

  Next, control of voltage (energization amount), which is a characteristic part of the electrolytic cleaning apparatus 1 and the electrolytic cleaning method according to the present embodiment, will be described.

  As shown in FIG. 4, the electrolytic cleaning apparatus 1 is configured such that the energization amount with the cathode 20 in a part of the anode parts 11 </ b> A among the plurality of anode parts 11 and 11 is different from that of the cathodes 20 in the other anode parts 11 </ b> B. It is configured to be controllable so that it is alternately switched between a large state and a small state compared to the energization amount.

  Specifically, the energization amount is controlled by a voltage applied between the anode part and the cathode. That is, in the electrolytic cleaning apparatus 1, among the voltages between the plurality of anode parts 11, 11 and the cathode 20, the voltage between a part of the anode parts 11 </ b> A and the cathode 20 is changed to the voltage between the other anode parts 11 </ b> B and the cathode 20. It is configured to be controllable so as to switch alternately between a high state and a low state.

  Further, the electrolytic cleaning apparatus 1 includes a state in which the voltage applied between the part of the anode part 11A and the cathode 20 is higher than the voltage applied between the other part of the anode part 11B and the cathode 20, and the part The voltage applied between the anode part 11B different from the anode part 11A and the cathode 20 can be switched to a state in which the voltage applied between the anode part 11A other than the other anode part 11B and the cathode 20 is higher. Composed. Note that when the applied voltage falls below about 2V (so-called overvoltage), the current does not flow and the electrolytic gas cannot be generated. Therefore, the voltage applied between some of the anode portions 11A and the cathode 20 is different. When the voltage applied is higher than the voltage applied between the anode portion 11B and the cathode 20, the voltage applied between a part of the anode portions 11A and the cathode 20 is set to at least an overvoltage.

  The anode 10 has a state in which a voltage is applied only between one anode part 11A and the cathode 20 of the two anode parts 11 and 11, and a voltage is applied only between the other anode part 11B and the cathode 20. The state to be switched can be switched. Specifically, the anode 10 has a voltage between the other anode portion 11B and the cathode 20 while the voltage is applied between the anode portion 11A and the cathode 20 of the two anode portions 11 and 11. While no voltage is applied and a voltage is applied between the other anode portion 11B and the cathode 20, no voltage is applied between the one anode portion 11A and the cathode 20.

  A voltage having a constant magnitude is alternately applied between the anode portions 11 and the cathode 20 every predetermined time. For example, a DC voltage of 5V is alternately applied between the anode portions 11A and 11B and the cathode 20 in a cycle of 30 seconds (that is, every 15 seconds).

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the description of only these examples, and can be appropriately modified within the scope of the object of the present invention. First, in the following Examples 1 and 2 and Comparative Examples 1 and 2, the lifetime of the electrolytic cleaning solution was verified.

<Example 1>
In Example 1, the electrolytic cleaning apparatus 1 shown in FIGS. 1 and 2 was used. The anode 10 includes two anode portions 11 that can be energized with different energization amounts with respect to the cathode, and each anode portion 11 includes four disk-shaped anode bodies 12 (diameter 36 mm). As the cathode 20, a stainless steel tray in which a plurality of small holes are formed is used as the support member 21. Moreover, as the cleaning object M, a steel material (width 30 mm, length 30 mm, height 10 mm) used as a material for a mold or a metal part was used. For the measurement, one cleaning object M was used. The cleaning object M was set side by side on the support member 21. The anode 10 was disposed so that the distance between the metal discharge portion and the upper end surface of the cleaning object M was 30 mm.

  As an electrolytic cleaning solution, an alkaline aqueous solution containing 4.5% by weight sodium hydroxide, 5% by weight ethylenediaminetetraacetic acid / tetrasodium, 2% by weight sodium gluconate, and a trace amount (for example, 1% by weight or less) of an amphoteric surfactant. An electrolytic cleaning solution (pH 13.6) consisting of The cleaning tank 3 of the electrolytic cleaning apparatus 1 has a capacity of 10 L, and 9 L of this electrolytic cleaning liquid was put into the cleaning tank 3.

  Since the electrolytic cleaning solution decreased during the electrolytic cleaning, water was appropriately supplemented as a replenisher. The amount of replenisher replenished by the end of the measurement was about 2200 mL.

  Then, electrolytic cleaning was performed by alternately applying a DC voltage of 5 V to the anode in a cycle of 30 seconds (that is, every 15 seconds) (current 30 to 45 A / square decimeter). Moreover, 40 kHz ultrasonic waves were irradiated simultaneously with the electrolytic cleaning. The liquid temperature was maintained at 45-60 ° C.

  Then, every hour, it is verified whether or not the cleaning object M is damaged (specifically, burnt or discolored), and the time until the cleaning object M is confirmed to be damaged is measured. did. As a verification, the object to be cleaned M is taken out from the electrolytic cleaning apparatus, washed with running water to remove the electrolytic cleaning liquid, blown and dried with argon gas, and using the naked eye and an optical microscope in a bright environment with illumination. Work was done to check for damage (specifically, burns and discoloration). As a result, in the verification after 43 hours, the cleaning object M was confirmed to be damaged. These are shown in Table 1.

<Comparative Example 1>
In Comparative Example 1, various conditions are basically the same as those of Example 1 except for the configuration of the anode and the voltage applied to the anode. In Comparative Example 1, as shown in FIG. 5, the anode 60 is composed of one anode portion 61, and the anode cleaning portion 51 uses an electrolytic cleaning apparatus 51 having six anode bodies 62. In addition, about the structure similar to the electrolytic cleaning apparatus 1 which concerns on Example 1 among the electrolytic cleaning apparatus 51 which concerns on the comparative example 1, the same code | symbol is attached | subjected and description is abbreviate | omitted. And the DC voltage of 5V was always applied, without changing the voltage to apply. The amount of replenisher (water) replenished before the measurement was completed was about 1500 mL. As a result, in the verification after 29 hours, the cleaning object M was confirmed to be damaged. These are shown in Table 1.

<Example 2>
The second embodiment is basically the same as the first embodiment except for the replenisher. In Example 2, as a replenisher, an alkaline aqueous solution (pH 13.6) containing 2.5% sodium hydroxide, 1% ethylenediaminetetraacetic acid / tetrasodium (EDTA-4Na), and a trace amount of amphoteric surfactant of 1% by weight or less. ) Was used. Further, the amount of the replenisher replenished before the measurement was completed was about 5000 mL. As a result, in the verification after 57 hours, the cleaning object M was confirmed to be damaged. These are shown in Table 1.

<Comparative example 2>
In Comparative Example 2, various conditions are basically the same as in Example 2 except for the voltage relating to the anode. In Comparative Example 2, a direct current of 5 V is applied to all eight anode bodies 12 without changing the voltage applied between the anode portions 11 and 11 and the cathode 20 with respect to the anode 10 as shown in FIG. A voltage was constantly applied. The amount of replenisher (alkaline aqueous solution) replenished by the end of the measurement was about 1500 mL. As a result, in the verification after 16 hours, the cleaning object M was confirmed to be damaged. These are shown in Table 1.

  As a result of the above measurement, it was confirmed that the life of the electrolytic cleaning liquid was longer in Examples 1 and 2 than in Comparative Examples 1 and 2.

  Next, in the following Examples 3 and 4 and Comparative Examples 3 and 4, the effect of electrolytic cleaning was verified.

<Example 3>
In Example 3, as the cleaning object M, a steel material having the same material and dimensions as those in the above examples and having red rust on the surface was used. Such a cleaning object M was prepared by degreasing a steel material with ethanol, spraying salt water, and allowing to stand at room temperature for 5 days.

  As the electrolytic cleaning apparatus 1, one having the same configuration as that used in Example 1 was used. Moreover, various conditions are the same as that of the said Example 1 except the point whose liquid temperature is 55-60 degreeC.

  And the time when it was confirmed that the red rust which generate | occur | produced on the surface of the washing | cleaning target object M disappeared by the electrolytic cleaning was measured. As a result, it was confirmed that red rust remained in the verification after 5 minutes, but disappeared in the verification after 10 minutes. These are shown in Table 2.

<Comparative Example 3>
In Comparative Example 3, various conditions are basically the same as in Example 3 except for the configuration of the anode and the voltage applied to the anode. Further, in Comparative Example 3, the anode 60 having the configuration shown in FIG. 5 similar to that used in Comparative Example 1 was used.

  And the time when it was confirmed that the red rust which generate | occur | produced on the surface of the washing | cleaning target object M disappeared by the electrolytic cleaning was measured. As a result, it was confirmed that red rust remained in the verification after 5 minutes, but disappeared in the verification after 10 minutes. These are shown in Table 2.

<Example 4>
In Example 4, except for the cleaning object M, various conditions are basically the same as in Example 3 described above. In Example 4, as the cleaning object M, a steel material having the same material and dimensions as those of the above examples and having an oxide film formed on the surface thereof was used. Such an object to be cleaned M is produced by heating a steel material with an electric heater in the air. Specifically, until the surface state changes from the original metal color to brown and further changes from brown to purple. After being heated (about 10 minutes), the object to be cleaned M having an oxide film mixed with brown and purple was formed on the surface.

  As a result of measurement using the cleaning object M, it was confirmed that the oxide film remained in the verification after 5 minutes, but disappeared in the verification after 10 minutes. These are shown in Table 2.

<Comparative example 4>
In Comparative Example 4, various conditions are basically the same as in Example 4 except for the configuration of the anode and the voltage applied to the anode. In Comparative Example 4, the anode 60 having the configuration shown in FIG. 5 similar to that used in Comparative Example 1 was used.

  As a result of measurement using the cleaning object M, it was confirmed that the oxide film remained in the verification after 5 minutes, but disappeared in the verification after 10 minutes. These are shown in Table 2.

<Example 5>
Example 5 is basically the same as Example 3 except for the configuration of the anode and the number of objects M to be cleaned. In Example 5, two anode parts 11 having different anodes 10 as shown in FIG. 6 were provided, and each anode part 11 used had 10 disc-like anode bodies 12. In addition, six cleaning objects M were used for the measurement.

  And the time when it was confirmed that the red rust which generate | occur | produced on the surface of the washing | cleaning target object M disappeared by the electrolytic cleaning was measured. As a result, it was confirmed that red rust partially remained in all the cleaning objects M in the verification after 5 minutes, but disappeared in all the cleaning objects M in the verification after 10 minutes. These are shown in Table 3.

<Comparative Example 5>
Comparative Example 5 is basically the same as Example 5 except for the configuration and arrangement of the anode and the number of objects to be cleaned. In Comparative Example 5, as shown in FIG. 7, the anode 60 was composed of one anode portion 61, and the anode portions 61 each having eight anode bodies 62 (diameter 50 mm) were used. Further, the two cleaning objects M in the center are arranged to face the anode, but the four washing objects M on the left and right are arranged not to face the anode.

  And the time when it was confirmed that the red rust which generate | occur | produced on the surface of the washing | cleaning target object M disappeared by the electrolytic cleaning was measured. As a result, in verification at the time of 5 minutes and at the time of 10 minutes, it was confirmed that some red rust remained in the cleaning object M arranged on the left and right with the electrode interposed therebetween. These are shown in Table 3.

  When Examples 3 and 4 are compared with Comparative Examples 3 and 4, in Examples 3 and 4, a voltage is always applied to a specific anode, although the voltage is not always applied. It was confirmed that the cleaning effects were comparable to those of Comparative Examples 3 and 4. From this, it was confirmed that when the applied voltage was controlled as described above, the same cleaning effect was achieved with a small amount of energization.

  Further, in consideration of the comparison in Examples 1 and 2 and the comparison in Examples 3 and 4, according to the electrolytic cleaning apparatus 1 and the electrolytic cleaning method according to the present example, the lifetime is obtained while achieving the cleaning effect of the same level as the conventional one. It has been confirmed that can be maintained for a long time.

  Further, from the comparison between Example 5 and Comparative Example 5, the cleaning object M arranged in the region sandwiched between the anode 10 and the cathode 20 can be suitably subjected to electrolytic cleaning, but the anode is positioned at a position facing the cathode. It was confirmed that the cleaning object M arranged in a region where no water is present cannot sufficiently perform electrolytic cleaning.

  As described above, according to the electrolytic cleaning apparatus 1 and the electrolytic cleaning method according to the present embodiment, the lifetime of the electrolytic cleaning liquid can be maintained long without deteriorating the cleaning effect. Therefore, since the electrolytic cleaning liquid can be used for a long time, the running cost can be reduced, and the frequency of waste liquid generation can be reduced to reduce the burden on the environment.

  That is, according to the electrolytic cleaning apparatus 1 and the electrolytic cleaning method according to the present embodiment, it is possible to maintain the same cleaning effect as in the case of the conventional electrolytic cleaning apparatus and the electrolytic cleaning method in which current is always uniformly supplied between the anode and the cathode. However, the life of the electrolytic cleaning solution can be maintained for a long time. One of the reasons why such an effect is exhibited is that the gas generation state in the cleaning object M held by the cathode 20 is constantly changed by constantly changing the energization amount between the specific anode portion 11 and the cathode 20. Therefore, it can be considered that a cleaning action such as a peeling action can be effectively applied to the dirt adhering to the cleaning object M. In addition, since the plurality of anode portions 11 are located at different positions, when the anode portion 11 having the largest amount of energization changes with time, the direction in which the cleaning action is applied fluctuates with time, and the cleaning action is changed to the object to be cleaned. One of the reasons is that it can be effectively added to the dirt adhering to M.

  Further, when the energization amount is changed from a large state to a small state, the generation of gas is suppressed. Here, the electrolytic cleaning liquid is in a state of being constantly stirred by the flow by the circulation means, the vibration by the ultrasonic vibration, the convection generated by the temperature difference, the convection generated by the rising of the gas, or the like. Accordingly, since the gas is removed from the surface of the cleaning object M by stirring the electrolytic cleaning liquid while the generation of gas is suppressed, the electrolytic cleaning liquid can be suitably supplied to the surface of the cleaning object M. The cleaning effect is further enhanced.

  In addition, the amount of energization can be suppressed as compared with the case where a constant voltage is constantly applied, and the life of the electrolytic cleaning solution can be extended accordingly. Moreover, since the amount of heat generated from the anode 10 is reduced by reducing the energization amount, a rapid temperature rise of the electrolytic cleaning liquid can be suppressed. Therefore, it is possible to easily control the temperature of the electrolytic cleaning liquid, and it is also possible to suitably prevent excessive generation of bubbles due to the surfactant added to the electrolytic cleaning liquid.

  In addition, since the energization amount is controlled by the voltage applied between the anode portion 11 and the cathode 20, the energization amount can be controlled by controlling the voltage, so that the energization amount can be easily controlled.

  Further, the electrolytic cleaning apparatus 1 includes a state in which the voltage applied between the part of the anode part 11A and the cathode 20 is higher than the voltage applied between the other part of the anode part 11B and the cathode 20, and the part The voltage applied between the anode part 11B different from the anode part 11A and the cathode 20 can be switched to a state in which the voltage applied between the anode part 11A other than the other anode part 11B and the cathode 20 is higher. Composed. Accordingly, a high voltage is applied at different timings between a part of the anode parts 11A and the cathode 20 and between another anode part 11B and the cathode 20, so that a cleaning action such as a peeling action adheres to the cleaning object M. It can be added more effectively against stained dirt.

  The anode 10 has a state in which a voltage is applied only between one anode part 11A and the cathode 20 of the two anode parts 11 and 11, and a voltage is applied only between the other anode part 11B and the cathode 20. The state to be switched can be switched. Therefore, since a voltage is always applied only to any one of the anode portions 11A and 11B and the cathode 20, the amount of energization can be suitably reduced.

  A voltage having a constant magnitude is alternately applied between the anode portions 11 and the cathode 20 every predetermined time. Therefore, since the total energization amount between each anode part 11 and the cathode 20 becomes the same, the cleaning object M can be electrolytically cleaned uniformly throughout.

  Furthermore, in the electrolytic cleaning apparatus 1 according to the above-described embodiment, a voltage is alternately applied between the two anode portions 11 and 11 and the cathode 20, and a voltage is applied between any one of the anode portion 11 and the cathode 20. No voltage is applied between the other anode part 11 and the cathode 20. Accordingly, since the current-carrying area per unit time of the anode 10 as a whole can be controlled to be smaller than the electrode area, a large electrode area can be secured. That is, since the anode body 12 can be provided more than before, it is possible to dispose the anode body 12 in a dispersed manner instead of locally. Therefore, the area of the cross section along the depth direction of the cleaning tank 3 can be covered evenly, and even a relatively large cleaning object M can be uniformly and electrolytically cleaned. Further, even when a plurality of objects to be cleaned M are simultaneously cleaned, the electrolytic cleaning can be performed uniformly without any unevenness for each object to be cleaned.

  Conventionally, if a large number of anode bodies 12 are arranged so as to cover the entire area of the cross section along the depth direction of the cleaning tank 3, the electrode area increases accordingly, and the energization amount becomes excessive. In addition to shortening the life of the electrolytic cleaning solution, there is a possibility that an excessive current locally flows in the cleaning object M and damages the cleaning object. In this regard, by performing electrolytic cleaning by the voltage control method as described above, the life of the electrolytic cleaning liquid can be maintained for a long time, and damage to the cleaning object M due to excessive current can be suitably prevented. .

  For example, when the object to be cleaned M is small, when it is desired to perform electrolytic cleaning within a range covered by some of the plurality of anode parts 11, some of the anode parts 11 and the cathodes. A voltage may be applied only between 20 (always or intermittently by repeating ON / OFF), and other voltage may not be applied constantly. That is, without using all of the arranged anode parts 11, electrolytic cleaning is performed by energizing only between the anode part 11 and the cathode 20 facing the place where the object to be cleaned M is installed. A current may not be passed between the anode portion 11 and the cathode 20 at a location where the cleaning liquid is not installed, so that the cleaning liquid is not wasted.

  The electrolytic cleaning apparatus 1 and the electrolytic cleaning method according to the present invention are not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  For example, the anode portion 11 constituting the anode 10 has been described as having a plurality of anode bodies 12, 12,..., But is not limited thereto, and the anode portion 11 has a flat discharge portion. And having an anode body disposed so that the discharge portion is located on a plane along a horizontal plane.

  Specifically, for example, as shown in FIG. 8, it is conceivable that the anode body 32 is formed with a space portion 33 communicating between both surfaces of the anode body 32. The anode body 32 is configured as a member having a mesh shape (lass shape), that is, a mesh body. In general, the electrolysis current has a property of flowing in a concentrated manner at the edge of the electrode. In this case, since such a net-like anode body 32 can secure a large number of edges, it is possible to suitably prevent the current distribution from being biased and to clean the cleaning object M uniformly.

  In addition, in the case of the anode body 32 in which the space portion 33 communicating between both surfaces is formed, the gas generated during the electrolytic cleaning escapes through the space portion 33, so that the gas is vertically below the anode body 32. Even if generated, the rising gas can be suitably released without the anode body 32 accumulating. From this viewpoint, it is preferable that a plurality of the space portions 33 are provided. However, as shown in FIG. 9, the anode body 42 may have a flat plate shape that does not have a space as described above.

  In the electrolytic cleaning apparatus 1, the anode 10 may include three or more anode portions 11. In this case, the voltage may be applied to each anode part 11 in order or randomly. For example, when there are three anode portions, different voltages may be sequentially applied to them, and these anode portions are divided into two sets of two and one, and different voltages are applied to each of the two sets. It may be a thing.

  Further, in the above embodiment, the energization amount is controlled by dividing the plurality of anode portions into two, but the present invention is not limited to this. As shown in the schematic diagram of FIG. The energization amount may be controlled separately as described above. When the anode 10 includes four anode parts 71 (71A to 71D), and these are divided into three parts of the anode parts 71A and 71B, the anode part 71C, and the anode part 71D to control the energization amount, Referring to FIG. 10, a portion of the anode portions 71A and 71B (shown as a group G1) and the cathode 20 between the other anode portions 71C and 71D (shown as a group G2) and the cathode 20 A state where a higher voltage is applied between the anode part 71A and 71B (G1) and the anode part 71C other than the anode part 71C other than the anode part 71C between the anode part 71C and the cathode 20 , 71D (referred to as group G3) and a state in which a voltage higher than that between the cathode 20 is applied. The anode portions 71A and 71B are set so that the energization amount to the cathode is the same.

  In addition, among the plurality of anode parts, the voltage applied only between a part of the anode parts and the cathode is controlled so as to fluctuate, and a constant voltage is always applied between the other anode parts and the cathode. The value may be set so as to be between a maximum value and a minimum value of a voltage applied between the partial anode portion and the cathode. Furthermore, the maximum value of the applied voltage may be different between the voltage applied between the part of the anode parts and the cathode and the voltage applied between the other anode part and the cathode.

  In addition, a voltage is applied between the plurality of anode portions 11 and the cathode 20 over the same time, but the application time is appropriately changed depending on the anode portion 11 without being limited thereto. It may be.

  The anode 10 is not applied with a voltage between the other anode part 11B and the cathode 20 while a voltage is applied between the one anode part 11A and the cathode 20, and between the other anode part 11B and the cathode 20. While no voltage is applied between the anode portion 11A and the cathode 20 while a voltage is applied to the cathode, the present invention is not limited to this. For example, as shown in FIG. 10, the timing at which a voltage is applied between a part of the anode parts 11 </ b> A and the cathode 20 and the part between the anode parts 11 </ b> A and the cathode 20 that are different from the part of the anode parts 11 </ b> A and the cathode 20. The timing at which the voltage is applied may partially overlap. In other words, there may be a state in which a voltage is simultaneously applied between the part of the anode portion 11A and the cathode 20 and between the anode portion 11B and the cathode 20 different from the anode portion 11A and the cathode 20. Further, as shown in FIG. 11, there may be a state in which no voltage is applied between any of the anode portions 11 </ b> A and 11 </ b> B and the cathode 20.

  Further, as shown in FIG. 11 and FIG. 12, the applied voltage value is not limited to a constant value, and may continuously vary from a low state to a high state. Further, the applied voltage is not limited to the one that continuously changes over time, but may be one that changes discontinuously.

  Further, the anode 10 was one in which no voltage was applied between the other anode part 11B and the cathode 20 while a voltage was applied between the partial anode part 11A and the cathode 20, While the voltage is applied between the part of the anode part 11A and the cathode 20, the part of the anode part 11A and the part of the anode part 11B and the cathode 20 which are different from the part of the anode part 11A and the cathode 20 are not limited thereto. A voltage smaller than that between the cathodes 20 may be applied.

  In the above embodiment, the ultrasonic cleaning is performed together, the electrolytic cleaning liquid is circulated, the electrolytic cleaning liquid is filtered, and the replenishing liquid is replenished during the electrolytic cleaning. However, the present invention is not limited to this. Rather, these incidental operations may not be performed during the electrolytic cleaning, and some of these incidental operations may be performed.

The top view of the electrolytic cleaning apparatus which concerns on embodiment of this invention is shown. Sectional drawing of the electrolytic cleaning apparatus which concerns on the same embodiment is shown. The anode part which comprises the anode of the electrolytic cleaning apparatus which concerns on the embodiment is shown, (A) shows the perspective view of the whole anode part, (B) shows the perspective view of the anode body of an anode part. In the electrolytic cleaning apparatus and the electrolytic cleaning method according to the embodiment, a graph of a waveform of a voltage applied between each anode portion and the cathode is shown. The top view of the electrolytic cleaning apparatus which concerns on a comparative example is shown. The top view of the electrolytic cleaning apparatus which concerns on other embodiment of this invention is shown. The top view of the electrolytic cleaning apparatus which concerns on another comparative example is shown. The perspective view of the anode part which comprises the anode used in the electrolytic cleaning apparatus which concerns on other embodiment of this invention is shown. The perspective view of the anode part which comprises the anode used in the electrolytic cleaning apparatus which concerns on other embodiment of this invention is shown. In the electrolytic cleaning apparatus and the electrolytic cleaning method which concern on other embodiment of this invention, the schematic explaining the division | segmentation of the anode part in the case of controlling the energization amount with respect to several anode parts is shown. In the electrolytic cleaning apparatus and the electrolytic cleaning method which concern on other embodiment of this invention, the graph of the waveform of the voltage applied between each anode part and a cathode is shown. In the electrolytic cleaning apparatus and the electrolytic cleaning method which concern on other embodiment of this invention, the graph of the waveform of the voltage applied between each anode part and a cathode is shown.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electrolytic cleaning apparatus, 2 ... Housing | casing, 3 ... Cleaning tank, 4 ... Power supply, 10 ... Anode, 11 (11A, 11B) ... Anode part, 12 ... Anode body, 12a ... Discharge part, 12b ... Insulator, 13 DESCRIPTION OF SYMBOLS ... Support body, 20 ... Cathode, 21 ... Support member, 21a ... Conductive part, 21b ... Insulator, 22 ... Hanging member, 22a ... Connection part with support member, 22b ... Connection part with power supply, 22c ... Insulator 32 ... Anode body, 33 ... Space part, 42 ... Anode body, 51 ... Electrolytic cleaning device, 60 ... Anode, 61 ... Anode part, 62 ... Anode body, 71 (71A, 71B, 71C, 71D) ... Anode part, L1 ... outline, L2 ... outline, M ... object to be cleaned, S ... gap region, G1, G2, G3 ... group

Claims (7)

An electrolytic cleaning apparatus in which an anode and a cathode holding an object to be cleaned are immersed in an electrolytic cleaning solution, and an electric current is passed between the anode and the cathode to electrolytically clean the object to be cleaned.
A power source for supplying power to the anode and the cathode;
The anode includes a plurality of anode portions that can be energized at different current values with respect to the cathode,
Wherein the power source, the current value of the cathode in some of the anode portion of the plurality of anode portions, switch alternately between high state and low state than the current value of the cathode of the other anode portion Electrolytic cleaning apparatus characterized by the above. 2. The electrolytic cleaning apparatus according to claim 1, wherein the current value is controlled by a voltage applied by the power source between the anode portions and the cathode. In the power source, a voltage applied between the part of the anode part and the cathode is higher than a voltage applied between the other part of the anode and the cathode, and an anode part different from the part of the anode part and electrolytic cleaning as claimed in claim 2, the voltage applied between the cathode and wherein the switching Operation exchange e Rukoto a state higher than the voltage applied between the anode part and cathode other than the anode of said another apparatus. The anode is constituted by two anode parts,
The power supply according to claim, characterized the state where a voltage only between one of the anode portions and the cathode is applied, the Switching Operation exchange e Rukoto a state in which a voltage only between the other of the anode portion and the cathode are applied 2. The electrolytic cleaning apparatus according to 2 or 3.   5. The electrolytic cleaning apparatus according to claim 4, wherein a voltage having a constant magnitude is alternately applied between the anode portions and the cathode every predetermined time. An electrolytic cleaning method in which an anode and a cathode holding an object to be cleaned are immersed in an electrolytic cleaning solution, and an electric current is passed between the anode and the cathode to electrolytically clean the object to be cleaned,
The anode includes a plurality of anode portions that can be energized at different current values with respect to the cathode,
The current value with respect to the cathode in a part of the anode portions of the plurality of anode portions is controlled so as to be alternately switched between a larger state and a smaller state than a current value with the cathode in the other anode portions. An electrolytic cleaning method characterized by the above. The anode is constituted by two anode parts,
The electrolytic cleaning method according to claim 6 , wherein a voltage having a constant magnitude is alternately applied between the anode portions and the cathode every predetermined time.

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