JP2005262155A - Ultrasonic cleaning apparatus using electrolytic alkaline water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safe cleaning apparatus aiming at a defatting, which aims at the improvement of cleaning qualities suppressing an oil content concentration in a cleaning liquid to a desired value or less, at the same time, reducing the use of wasteful wash water, having an economical efficiency by controlling minimally a cost of equipment, and does not have a bad influence on the environment. <P>SOLUTION: A wash water discharge part 3 discharging used electrolytic alkaline water containing the oil content, and an introduction part 12 introducing another electrolytic alkaline water are provided on an ultrasonic cleaning tub 1 ultrasonically cleaning a material to be washed using the electrolytic alkaline water AW. A turbidity meter 14 is provided on a circulation pipe 13 installed to the ultrasonic cleaning tub 1, and when a turbidity meter value becomes a turbidity check value, the electrolytic alkaline water AW is interchanged. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides an ultrasonic cleaning apparatus for cleaning objects to be cleaned such as various metal parts, optical lenses, and resin parts in general technical fields including machinery, metal, and electronics using an electrolytic alkaline water. More particularly, the present invention relates to an ultrasonic cleaning apparatus using electrolytic alkaline water that can suitably perform oil concentration control of cleaning water in cleaning mainly for degreasing.

  The “degreasing and cleaning method for aluminum parts and the like” described in Patent Document 1 describes a cleaning method mainly for degreasing regarding cleaning of aluminum parts. In this document, dirt adhering to a work, that is, oil and fat and cutting debris, is peeled and removed by ultrasonic vibration and the action of an underwater jet in a cleaning tank. The removed oil is separated to the water surface of the washing tank, floats and overflows, and is discharged outside the tank. In addition, when the workpiece is completely cleaned, when the workpiece is pulled up from the tank, pure water is poured in a shower form so that the oil that is separated and floats on the water surface portion of the cleaning tank does not adhere to the workpiece again. However, in order to prevent the separated floating oil from reattaching to the workpiece, there is a problem that a large amount of rinse water is required and the burden on facilities such as shower cleaning equipment increases.

  Further, in the cleaning mainly for degreasing, the oil is difficult to dissolve in water, so that the oil removed from the workpiece by the cleaning floats separately from the water without being uniformly dispersed in the tank. That is, the separated oil is separated into two layers, a floating oil layer and a washing water layer below the oil layer (part of the oil dissolves). However, since the oil concentration in each layer is different, even if a single turbidimeter (turbidimeter described in Patent Document 2) or an oil concentration meter is used, There is also a problem that oil stains cannot be detected accurately.

  Further, in order to accurately measure the oil content in the washing water, a method is adopted in which the oil content of the washing liquid is extracted into a solvent and measured by gravimetric method or infrared spectroscopy. (Examples of commercially available oil concentration meters include Horiba, OCMA-300, etc.)

  However, it takes time to measure the oil content using the above oil concentration meter, and it is difficult to monitor dirt in real time. Empirical management was performed. In addition, as described in Patent Document 1, for cleaning water stains, new cleaning water is continuously or intermittently introduced into the cleaning tank, and the oil component separated and floated is overflowed from the tank. In many cases, the contamination of the liquid is maintained at a predetermined level, and when the workpiece is pulled up, the workpiece is washed with pure water so that the floating oil does not reattach to the workpiece. However, as described above, this method requires a lot of rinse water and increases the burden on the facility.

Further, the applicant of the present application described in Patent Document 3 “Ultrasonic cleaning method and apparatus using electrolytic alkaline water”, cleaning method using electrolytic alkaline water cleaning effect, ultrasonic cleaning effect, and its Proposals related to equipment. However, even in cleaning using these electrolytic alkaline waters, there is a problem regarding the handling of oil as in the above.
JP-A-8-269755 JP-A-7-209184 JP 2000-320934 A

  Therefore, the technical problem of the present invention is not to use the one whose use is prohibited or restricted by legal regulations such as Freon and ethane in cleaning mainly for degreasing, and is safe for the environment. It is a detergent that contains a surfactant and the like, and is not a cleaning that requires a large amount of rinse water to rinse the surfactant.

  Another technical problem of the present invention is that, in cleaning mainly for degreasing, the oil contained in the cleaning water in the tank is uniformly dispersed in the cleaning water without being separated and floated, and is brought into the cleaning water. The detected oil can be detected in real time as needed by a detector installed in the wash water. In other words, the oil concentration in the wash water is detected online, and before the oil concentration in the wash water increases and separates and floats, necessary measures such as replacement of the wash water and addition of new liquid are performed. This makes it possible to control the oil concentration in the cleaning liquid.

(1) In order to solve the above technical problem, an ultrasonic cleaning apparatus using electrolytic alkaline water according to claim 1 of the present invention is ultrasonic cleaning using electrolytic alkaline water generated by electrolysis as cleaning water. An ultrasonic cleaning apparatus using electrolytic alkaline water configured to ultrasonically clean an object to be cleaned mainly for degreasing and cleaning inside the ultrasonic cleaning tank by introducing into the tank, The ultrasonic cleaning tank is provided with a cleaning water introduction section for introducing newly generated electrolytic alkaline water and a cleaning water discharge section for discharging used electrolytic alkaline water containing oil, and the ultrasonic cleaning tank And a place where the electrolytic alkaline water circulates is provided with a turbidimeter for detecting the turbidity value of the electrolytic alkaline water, and the oil concentration of the electrolytic alkaline water. When the turbidity value for management is detected and the turbidity meter detects the turbidity value for oil concentration management, the cleaning water introduction unit or the cleaning water discharge unit is controlled to A control unit for adding or replacing electrolytic alkaline water to the sonic cleaning tank is provided.

(2) Moreover, the ultrasonic cleaning apparatus using electrolytic alkaline water according to claim 2 of the present invention is provided with an input means capable of setting and inputting a turbidity value for oil concentration management in the control unit. It is characterized by that.

(3) Moreover, the ultrasonic cleaning apparatus using electrolytic alkaline water according to claim 3 of the present invention is characterized in that the turbidity value for oil concentration management is an oil concentration upper limit value in electrolytic alkaline water. .

(4) In the ultrasonic cleaning apparatus using electrolytic alkaline water according to claim 4 of the present invention, the turbidimeter is a transmitted light measurement type turbidimeter or a scattered light measurement type turbidimeter. It is characterized by.

(5) Moreover, the ultrasonic cleaning apparatus using the electrolytic alkaline water according to claim 5 of the present invention is a cleaning water circulation that circulates the electrolytic alkaline water in the ultrasonic cleaning tank adjacent to and in communication with the ultrasonic cleaning tank. A route is provided, and the turbidimeter is provided in the washing water circulation route.

(6) Furthermore, the ultrasonic cleaning apparatus using electrolytic alkaline water according to claim 6 of the present invention is in the path of the cleaning water circulation path, and is upstream of the position where the turbidimeter is provided. The feature is that a washing water introduction section is provided.

  According to the means described in (1) above, when an object to be cleaned that is primarily intended for degreasing is put into electrolytic alkaline water and subjected to ultrasonic cleaning, oil such as oil and fat adhering to the object to be cleaned becomes ultrasonic. The oil component separated from the workpiece and cleaned by the above-described cleaning is refined by the action of ultrasonic waves.

  In the electrolytic alkaline water, dissolved hydrogen and fine bubble hydrogen exist, and since the physical force by the ultrasonic wave is enhanced, the cleaning effect is enhanced and the oil component which is dirt is easily dispersed. Furthermore, in electrolytic alkaline water, the fats and oils contained as additives in the water-insoluble metalworking oil may be saponified and changed to substances having a surface-active effect, which will contribute to stabilization of oil dispersion. Even if the processing oil does not contain oil (cutting oil, GC-32, manufactured by Nippon Oil Corporation), the same tendency is shown as shown in FIG. However, the time that can exist stably tended to be short as compared with oils containing fats and oils. (Refer to FIG. 7 (B))

  The oil component separated from the workpiece in this way is uniformly dispersed in the cleaning liquid by the action of the ultrasonic waves and the action of dissolved hydrogen and fine bubble hydrogen contained in the electrolytic alkaline water. The oil that has been uniformly emulsified and dispersed has a high turbidity, and is detected by a turbidimeter and outputs a detection output. The detection output changes in proportion to the amount of oil supplied within a certain oil concentration, and when it exceeds a certain limit value, it separates from the wash water and rises. Therefore, the oil concentration can be managed within a predetermined value by managing the value indicated by the turbidimeter. It has been found that the oil concentration affects the cleaning quality (see FIG. 6), and it becomes possible to set the necessary control limit values and perform quality control.

  Although there is an example in which a turbidimeter is used for measuring the oil concentration in industrial water or river water, the oil concentration that can be stably dispersed in water is extremely low even when ultrasonic vibration is used. That is, it will separate into two layers of water and oil. Therefore, a confirmation experiment was conducted on water other than electrolytic alkaline water. As described above, the oil and water were separated, and the oil was not uniformly dispersed in the cleaning liquid. Moreover, in the cleaning liquid containing a water-soluble detergent, the value indicated by the turbidimeter changed during the course of oil cleaning, and the correct oil concentration could not be detected. Therefore, only in the case of ultrasonically cleaning the oil using electrolytic alkaline water, the oil can be uniformly dispersed in the cleaning liquid, and the oil concentration can be detected using a turbidimeter, and the time has elapsed. It can be said that the oil concentration can be stably measured without any change in the measured value in the turbidimeter.

  FIG. 2 is a graph showing an oil concentration and a turbidimeter when oil is added to electrolytic alkaline water and ultrasonic waves are applied (showing a relationship between an oil concentration analysis value by solvent extraction and a turbidimeter value), The value indicated by the turbidimeter with respect to the oil concentration is proportional, whereas the value indicated by the turbidimeter with respect to the oil concentration when oil is mixed in the tap water in FIG. 4 shows a proportional relationship. Absent. In other words, when the same amount of oil is added, the electrolytic alkaline water can correctly detect the concentration, but tap water causes the oil to float and cannot be detected correctly by the turbidimeter. In addition, the oil concentration value in FIG. 2 or FIG. 4 is the wash water measured beforehand using the oil concentration meter (for example, Horiba OCMA-300).

  If the management value of the oil concentration described above is used as the oil floating limit value, it is possible to prevent the floating oil from reattaching even in the worst state. In addition, when the control value is detected, automatic operation can be performed by operating each control unit so as to introduce new electrolytic alkaline water and discard the old washing water.

  Further, according to the means described in the above (1), the turbidimeter value corresponding to the management target oil concentration is stored in the storage unit, and when the stored value is detected, the detection is performed. A signal is transmitted, and control is performed for replacement of new liquid, introduction of cleaning water for adding new liquid, and discharging of cleaning water.

  Further, according to the means described in (2) above, the oil concentration required for quality can be set by inputting the turbidity control value, and according to the means described in (3) above, the oil component is separated and floated. By setting a value to be used, reattachment of floating oil to the workpiece can be prevented, and according to the means described in (4) above, the turbidimeter can detect emulsified oil and catch it as turbidity. According to the means described in the above (5), since the turbidimeter is provided at the place where the cleaning water circulates, the concentration of the cleaning water in the cleaning tank can be detected on average, and the means described in the above (6) According to the above, since new washing water passes through the place where the turbidimeter is provided, it is possible to prevent erroneous detection due to contamination of the turbidimeter.

  As described above, according to the ultrasonic cleaning apparatus using the electrolytic alkaline water according to the present invention, in cleaning for the purpose of degreasing, the oil concentration in the cleaning liquid is suppressed to a target value or less to improve the cleaning quality. At the same time, it is possible to provide a safe cleaning apparatus that is economical and reduces the use of wasted cleaning water, minimizes equipment costs, and does not adversely affect the environment.

  Hereinafter, an embodiment of an ultrasonic cleaning apparatus using electrolytic alkaline water according to the present invention will be described with reference to the configuration diagram shown in FIG. 1. In FIG. 1, reference numeral 1 denotes an ultrasonic oscillator 2 at the bottom. The ultrasonic cleaning tank AW provided is electrolytic alkaline water (cleaning water) accommodated in the cleaning tank 1, and the object to be cleaned is ultrasonically cleaned in the electrolytic alkaline water AW. Reference numerals 3A and 3B denote an overflow valve and a liquid exchange (drainage) electromagnetic valve provided on the upper and lower parts of the ultrasonic cleaning tank 1, respectively, and a washing water discharge section is provided by these upper and lower valves 3A and 3B. 3 is configured.

  10 and 12 are a drainage part (drainage port) and an introduction part (inlet port) for circulating cleaning water provided at the upper and lower parts of the ultrasonic cleaning tank 1, and 13 is an upper and lower drainage part. 10 shows a washing water circulation pipe (circulation path) connecting between the introduction pipe 12 and the introduction section 12, and a drain pipe 13A and an introduction pipe 13B connected to the upper and lower sides of the circulation pipe 13 are connected to the drain section 10 and the introduction section 12, respectively. Has been.

  15 is an electromagnetic switching valve provided with a solenoid 15M, the first port is connected to the drain pipe 13A, the second port is connected to the main pipe side (in the direction of the introduction pipe 13B) of the circulation pipe 13, The third port is connected to a supply pipe 16A of a new liquid tank 16 containing a new liquid of electrolytic alkaline water.

  14 is a turbidimeter of the transmitted light measurement system or the scattered light measurement system provided in the path of the washing water circulation pipe 13 and downstream of the switching valve 15, and the turbidimeter 14 circulates in the washing water circulation. A function of detecting the turbidity value of the electrolytic alkaline water AW (washing water) flowing through the pipe 13 and sending the detected value to the control unit 20 is provided.

  17 is a pump provided in the path of the washing water circulation pipe 13, and this pump 17 circulates the electrolytic alkaline water AW in the ultrasonic washing tank 1 through the washing water circulation pipe 13, while the switching valve 15 A function of supplying new electrolytic alkaline water AW in the new liquid tank 16 into the ultrasonic cleaning tank 1 according to the switching is provided.

  The control unit 20 is provided with a storage unit 21 for setting and storing a turbidity value for oil concentration management of the electrolytic alkaline water AW and an input unit 22 for setting and inputting the turbidity value. The turbidity value for oil concentration management is the upper limit value of oil concentration in electrolytic alkaline water, and the turbidity value of electrolytic alkaline water AW detected by the turbidimeter 14 is the oil concentration as the cleaning time elapses. When the turbidity value for management is reached, the control unit 20 controls the operation of the above-described liquid exchange electromagnetic valve 3B, the electromagnetic switching valve 15 or the pump 17, and the electrolytic alkaline water in the ultrasonic cleaning tank 1 is controlled. The AW is replaced with a new solution, or the electrolytic alkaline water AW is replenished (injected) with a new solution to adjust the turbidity value to be equal to or less than the value for oil concentration management.

  The turbidity management value varies depending on the cleaning quality of what is to be cleaned, so that the necessary value can be input and stored. In order to prevent the oil from floating in the cleaning tank 1, the upper limit value of the oil concentration that can be dispersed in the electrolytic alkaline water may be set as the turbidity control value.

  In the illustrated embodiment, a configuration in which the turbidimeter 14 is provided in the middle of the cleaning water circulation pipe 13 provided in the ultrasonic cleaning tank 1 and the electrolytic alkaline water AW is forcibly circulated by the pump 17 is adopted. Therefore, the turbidity state of the electrolytic alkaline water AW in the cleaning tank 1 can be detected on average. Further, because the switching valve 15 for introducing a new liquid is provided upstream of the turbidimeter 14, the turbidimeter 14 can be washed when the new liquid is supplied to prevent a decrease in sensitivity due to contamination of the turbidimeter 14. .

  As a result of conducting an experimental study using the ultrasonic cleaning apparatus having the above configuration, the following results were obtained.

  When the workpiece to which the oil component is attached is ultrasonically cleaned using electrolytic alkaline water, the oil component can be well washed away by the effect of the electrolytic alkaline water and the action of ultrasonic waves. The separated and removed oil is uniformly dispersed in the cleaning liquid by the effect of fine hydrogen bubbles of electrolytic alkaline water and the action of ultrasonic waves.

  The oil component (emulsified state) dispersed in the cleaning liquid can be detected by the turbidimeter 14, and the oil concentration can be determined from the value indicated by the turbidimeter. That is, the value indicated by the turbidimeter 14 is turbidity, but the concentration of oil in the wash water and the value obtained when the wash water indicating the concentration is measured by the turbidimeter 14 are previously determined based on experimental values. The oil concentration can be measured from the value of the turbidimeter 14 by making it correspond to. (See Figure 2)

Further, the amount of oil brought into the washing tank 1 separates and floats when it exceeds a predetermined oil concentration range, but the value indicated by the turbidimeter 14 is proportional to the oil concentration until the separated and floated concentration is reached. It was also found to show a high turbidity value. From this, it was found that the input oil was mixed and mixed in the wash water in proportion to the input amount up to a predetermined oil concentration. (See Figure 3)

  On the other hand, regarding the dispersion of the oil, an attempt was made under the same conditions as in the case of electrolytic alkaline water to determine what aspect in normal tap water. The detected value did not show a proportional value corresponding to the oil content, and did not show a value above a certain turbidity value (the oil concentration in the wash water did not rise above the specified concentration). ). In other words, in ordinary tap water, unlike electrolytic alkaline water, oil is difficult to disperse in water even when subjected to ultrasonic waves, and it is separated into two layers of water and oil, and the oil concentration in the wash water is predetermined. There was no rise above the value of. Therefore, it came to the conclusion that the oil mixed in normal tap water cannot be measured using the turbidimeter 14.

  Further, when the washing water after washing is left for a while and the state of change of the value indicated by the turbidimeter 14 with the passage of time is examined, in the electrolytic alkaline water, the change indicated by the turbidimeter 14 over time does not occur. On the other hand, in the washing water using a water-soluble detergent, the value indicated by the turbidimeter 14 changed with the passage of time, and the value decreased with the passage of time. Accordingly, it was concluded that it is not appropriate to measure the oil concentration using the turbidimeter 14 in the washing water using the detergent. (See Figure 5)

  In addition, it was confirmed that the cleaning quality depends on the oil concentration in the electrolytic alkaline water. This is more convinced of the necessity of managing the oil concentration of electrolytic alkaline water using the turbidimeter 14 and means that finer cleaning quality can be achieved. (See Figure 6)

  From the above, in cleaning intended for degreasing, ultrasonic cleaning is performed using electrolytic alkaline water, and the concentration of oil contained in the contaminated cleaning water is measured using the turbidimeter 14. From this main configuration, the following results could be obtained.

  Effective cleaning of oil (synergistic effect of ultrasonic and electrolytic alkaline water), uniform dispersion of oil in cleaning water (synergistic effect of ultrasonic and gas in electrolytic alkaline water), concentration of oil in cleaning water Can be regarded as a turbidimeter value (effect of dispersing and saponifying and emulsifying oil by the action of ultrasonic waves and electrolytic alkaline water), and accurate oil concentration that is proportional to the amount of oil introduced (Effect of making it possible to detect oil content dispersed by saponification / emulsification in the liquid with a turbidimeter), and correctly detecting oil stains in the wash water in real time as the oil concentration during workpiece cleaning (Installed directly in the washing tank and provided with detection output means), enabling the oil concentration management to determine and maintain the required degreasing quality.

The block diagram explaining the whole ultrasonic cleaning apparatus using the electrolytic alkaline water which concerns on this invention. The graph which showed the relationship between the oil content concentration (analysis value) of electrolysis alkaline water (cleaning liquid), and a turbidimeter value. A graph showing the relationship between the oil concentration brought in and the turbidimeter value. The graph which showed the turbidimeter value when oil was disperse | distributed in tap water. The graph which showed the comparison (aging change) of the turbidity value in detergent and electrolytic alkaline water. The graph which showed the relation between cleaning fluid oil concentration and the amount of residual oil. (A) is the graph which showed the turbidimeter value of the processing oil without fat addition, (B) is the graph which showed the turbidity meter value (time-dependent change) of the processing oil without fat addition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic washing tank 2 Ultrasonic oscillator 3 Washing water discharge part 10 Drainage part (drainage port) for circulation of washing water
12 Introduction part (inlet) for circulation of washing water
13 Circulation pipe (circulation path)
14 Turbidimeter 15 Electromagnetic switching valve 16 New liquid tank 17 Pump 20 Control unit 21 Storage unit 22 Input unit AW Electrolytic alkaline water (washing water)

Claims (6)

By introducing electrolytic alkaline water generated by electrolysis into the ultrasonic cleaning tank as cleaning water, the object to be cleaned mainly for degreasing cleaning is ultrasonically cleaned inside the ultrasonic cleaning tank. An ultrasonic cleaning device using electrolytic alkaline water,
The ultrasonic cleaning tank is provided with a cleaning water introduction section for introducing newly generated electrolytic alkaline water and a cleaning water discharge section for discharging used electrolytic alkaline water containing oil, and the ultrasonic cleaning A turbidimeter for detecting the turbidity value of the electrolytic alkaline water is provided at the inside of the tank or in a place where the electrolytic alkaline water circulates, and the oil content of the electrolytic alkaline water. When the turbidity value for concentration management is set and stored, and when the turbidimeter detects the turbidity value for oil concentration management, the washing water introduction unit or the washing water discharge unit is controlled, An ultrasonic cleaning apparatus using electrolytic alkaline water, comprising a controller for adding or replacing electrolytic alkaline water to an ultrasonic cleaning tank.   An ultrasonic cleaning apparatus using electrolytic alkaline water, characterized in that an input means capable of setting and inputting a turbidity value for oil concentration management is provided in the control unit.   The ultrasonic cleaning apparatus using electrolytic alkaline water according to claim 1 or 2, wherein the turbidity value for oil concentration management is an oil concentration upper limit value in electrolytic alkaline water.   4. The ultrasonic cleaning apparatus using electrolytic alkaline water according to claim 1, wherein the turbidimeter is a transmitted light measuring turbidimeter or a scattered light measuring turbidimeter.   2. A cleaning water circulation path for circulating electrolytic alkaline water in the ultrasonic cleaning tank is provided adjacent to and in communication with the ultrasonic cleaning tank, and the turbidimeter is provided in the cleaning water circulation path. , 2, 3 or 4, an ultrasonic cleaning apparatus using the electrolytic alkaline water.   6. A washing water introduction part is provided in a part of the washing water circulation path upstream of the position where the turbidimeter is provided. An ultrasonic cleaning apparatus using the electrolytic alkaline water described in 1.

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