JP2022026337A - Wash solution replacement forecasting device, wash solution replacement forecasting system, wash solution forecasting method and program - Google Patents

Abstract

To provide a technique capable of highly accurately forecasting a replacement time of wash solution for use in an alkali immersion degreasing process.SOLUTION: A wash solution replacement forecasting device 3 time-sequentially arranges pH values of wash solution 60 sequentially measured after replacement of the wash solution 60 by a pH sensor 2 installed at a prescribed position in a washing tank 61, specifies a graph representing transition of the pH values of the wash solution 60 in the washing tank 61 and extracts a bottom-side change point and a top-side change point from the graph. The wash solution replacement forecasting device performs a filtering process for removing measurement values between the bottom-side change point and the top-side change point arranged in order from the bottom-side change point to the top-side change point and acquires a regression line from the graph after the filtering process. Then, the wash solution replacement forecasting device uses the regression line to calculate a time when the pH value of the wash solution 60 in the washing tank 61 reaches a threshold value predetermined as a pH value requiring to replace the wash solution 60, as a replacement forecasting time of the wash solution 60.SELECTED DRAWING: Figure 1

Description

The present invention relates to a technique for predicting the replacement time of a cleaning liquid used for a cleaning treatment such as an alkaline immersion degreasing treatment.

Conventionally, in metal processing or the like, a cleaning solution of an alkaline solution to which a surfactant is added is stored in a cleaning tank, and the work is immersed in the cleaning solution stored in the cleaning tank to adhere to the surface of the work. Alkaline immersion degreasing treatment for removing rust-preventive oil, processing oil, etc. is used. Here, the higher the alkalinity of the cleaning liquid, the stronger the cleaning power. However, since the alkalinity decreases and the detergency deteriorates due to long-term use, it is necessary to replace the cleaning liquid.

Patent Document 1 discloses a technique of measuring the pH value of a cleaning liquid before and after a cleaning operation and evaluating the cleaning power of the cleaning liquid using the difference between them as an index value. By evaluating the detergency of the cleaning liquid using this technique, the user can determine whether or not the cleaning liquid needs to be replaced each time.

Japanese Unexamined Patent Publication No. 10-73583

During the operation of the alkaline immersion degreasing equipment, the cleaning liquid of the alkaline solution stored in the cleaning tank is removed from the cleaning tank by a circulation pump, impurities are removed by a filter, and then returned to the cleaning tank. Therefore, the cleaning liquid in the cleaning tank is agitated, and the pH value of the cleaning liquid in the cleaning tank becomes uniform. On the other hand, when the alkaline immersion degreasing treatment equipment is not in operation, the circulation pump is stopped, so that the cleaning liquid in the cleaning tank is not agitated and the pH value of the cleaning liquid in the cleaning tank becomes non-uniform. Therefore, the technique described in Patent Document 1 is applied to the alkaline immersion degreasing equipment, and the pH value of the cleaning liquid is measured before and after the operation of the cleaning equipment by a sensor installed at a predetermined position in the cleaning tank, and the difference between them is measured. When the detergency of the cleaning solution is evaluated using the above as an index value, the noise component contained in the pH value measured by the sensor becomes large depending on the timing, and the detergency of the cleaning solution may not be evaluated correctly.

Further, the technique described in Patent Document 1 does not take any consideration into predicting a future replacement time. If it is possible to predict the future replacement time, it is sufficient to procure the cleaning liquid by the predicted replacement time, and there is an advantage that the inventory management cost of the cleaning liquid can be reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique capable of predicting the replacement time of a cleaning liquid used for a cleaning treatment with high accuracy.

In order to solve the above problems, the present invention presents a cleaning tank in which a cleaning liquid of an alkaline solution to which a surfactant is added is stored, a filter for removing impurities contained in the cleaning liquid, and a cleaning tank and a filter. In a cleaning facility equipped with a circulation pump that circulates the cleaning liquid between and, the replacement time of the cleaning liquid is predicted.

In one aspect of the present invention, the pH value of the cleaning liquid in the cleaning tank is sequentially measured by a sensor installed at a predetermined position in the cleaning tank, and the measured values are arranged in chronological order in the order of the measurement time based on the measurement time, and the cleaning liquid is used. A graph showing the transition of the pH value of the cleaning liquid in the cleaning tank after charging or replacement is specified. Then, the bottom side change point where the slope of the graph showing the transition of the pH value of the washing liquid in the washing tank changes from minus to plus and the top side change point where the slope changes from plus to minus are extracted, and the bottom side change point, A filtering process is performed to remove the measured values between the bottom side change points and the top side change points arranged in the order of the top side change points. Then, a regression line is obtained from the graph after the filtering process, and the time when the pH value of the washing liquid reaches a predetermined threshold value as the pH value requiring replacement of the washing liquid is calculated using this regression line, and this time. Is output as a predicted value of the replacement time of the cleaning liquid.

In the filtering process, the measured value included in the period from the top change point to the elapse of a predetermined time (pH value stabilization standby time) is also removed from the graph showing the transition of the pH value of the cleaning liquid in the cleaning tank. You may do so.

For example, one aspect of the present invention is
A cleaning tank in which a cleaning liquid of an alkaline solution to which a surfactant is added as needed is stored, a filter for removing impurities contained in the cleaning liquid, and a circulation pump for circulating the cleaning liquid between the cleaning tank and the filter. It is a cleaning liquid exchange prediction device that predicts the exchange time of the cleaning liquid in the cleaning equipment provided with
A measurement value acquisition means for acquiring the pH value of the cleaning liquid sequentially measured by a sensor installed at a predetermined position in the cleaning tank together with the measurement time.
The pH value of the cleaning liquid in the cleaning tank obtained by arranging the pH values of the cleaning liquid acquired by the measured value acquisition means in chronological order in the order of the measurement time after the cleaning liquid is charged into the cleaning tank or after replacement. A change point extraction means for extracting the bottom side change point where the slope of the graph showing the transition of the change from minus to plus and the top side change point where the slope changes from plus to minus,
For each bottom-side change point extracted by the change point extraction means, a measurement between the bottom-side change point and the top-side change point extracted by the change point extraction means following the bottom-side change point. A filtering means that performs a filtering process for removing the value from the graph,
A regression line calculation means for calculating a regression line from the graph on which the filtering process is performed by the filter means, and a regression line calculation means.
Using the regression line calculated by the regression line calculation means, the time when the pH value of the cleaning liquid reaches a predetermined threshold value as the pH value requiring replacement of the cleaning liquid in the cleaning tank is set. Exchange prediction time calculation means to calculate as the exchange prediction time of
It has an exchange prediction time output means for outputting the exchange prediction time of the cleaning liquid calculated by the exchange prediction time calculation means.

Further, in another aspect of the present invention, the pH value of the cleaning liquid is sequentially measured by a sensor installed at a predetermined position in the cleaning tank, and the measured values are arranged in chronological order in the order of measurement time, after the cleaning liquid is added or replaced. A graph showing the transition of the pH value of the washing liquid in the washing tank of No. 1 is specified. Then, the bottom side change point where the slope of the graph showing the transition of the pH value of the washing liquid in the washing tank changes from minus to plus is extracted, and for each bottom side change point, this bottom side change point and thereafter. Of the measured values included between the side change point and the bottom side change point, the filtering process for removing the measured value of the pH value higher than this bottom side change point is performed. Then, a regression line is obtained from the graph after the filtering process, and the time when the pH value of the washing liquid in the washing tank becomes a predetermined threshold value as the pH value requiring replacement of the washing liquid is determined by using this regression line. It is calculated, and this calculated time is output as a predicted value of the cleaning liquid replacement time.

For example, another aspect of the invention is
A cleaning tank in which a cleaning liquid of an alkaline solution to which a surfactant is added as needed is stored, a filter for removing impurities contained in the cleaning liquid, and a circulation pump for circulating the cleaning liquid between the cleaning tank and the filter. It is a cleaning liquid exchange prediction device that predicts the exchange time of the cleaning liquid in the cleaning equipment provided with
A measurement value acquisition means for acquiring the pH value of the cleaning liquid sequentially measured by a sensor installed at a predetermined position in the cleaning tank together with the measurement time.
The pH value of the cleaning liquid in the cleaning tank obtained by arranging the pH values of the cleaning liquid acquired by the measured value acquisition means in chronological order in the order of the measurement time after the cleaning liquid is charged into the cleaning tank or after replacement. A change point extraction means for extracting the bottom side change point where the slope of the graph showing the transition of the change from minus to plus,
For each bottom-side change point extracted by the change point extraction means, among the measured values included between the bottom-side change point and the next bottom-side change point of the bottom-side change point, the bottom-side change. A filter means for performing a filtering process for removing a measured value having a pH value higher than a point from the graph,
A regression line calculation means for calculating a regression line from the graph on which the filtering process is performed by the filter means, and a regression line calculation means.
Using the regression line calculated by the regression line calculation means, the time when the pH value of the cleaning liquid reaches a predetermined threshold value as the pH value requiring replacement of the cleaning liquid in the cleaning tank is set. Exchange prediction time calculation means to calculate as the exchange prediction time of
It has an exchange prediction time output means for outputting the exchange prediction time of the cleaning liquid calculated by the exchange prediction time calculation means.

According to the present inventor, in a cleaning facility for cleaning treatment such as alkaline immersion degreasing treatment, the pH value of the cleaning liquid of the alkaline solution stored in the cleaning tank decreases during operation while increases during non-operation. I found. Furthermore, it was found that by repeating operation and non-operation, the cycle of decrease and increase is repeated, and the overall decrease gradually with the passage of time.

Therefore, in one aspect of the present invention, the pH values of the cleaning liquids sequentially measured after the cleaning liquid is charged or replaced by the sensors installed at predetermined positions in the cleaning tank are arranged in chronological order in the order of measurement time, and the pH values in the cleaning tank are arranged in chronological order. A graph showing the transition of the pH value of the washing liquid is specified, and the bottom side change point and the top side change point of this graph are extracted. Then, a filtering process is performed to remove the measured values between the bottom side change points and the top side change points arranged in the order of the bottom side change point and the top side change point, and the regression line is obtained from the graph after the filtering process. , Predicts when to replace the cleaning solution.

Further, in another aspect of the present invention, the pH values of the cleaning liquids sequentially measured after the cleaning liquid is charged or replaced by the sensors installed at predetermined positions in the cleaning tank are arranged in chronological order in the order of the measurement time, and the pH values are arranged in the cleaning tank in chronological order. A graph showing the transition of the pH value of the washing liquid of No. 1 is specified, and the bottom side change point of this graph is extracted. Then, for each of the extracted bottom-side change points, among the measured values included between this bottom-side change point and the next bottom-side change point of this bottom-side change point, the pH value is higher than this bottom-side change point. A filtering process for removing high measurement points is performed, and a regression line is obtained from the graph after the filtering process to predict the replacement time of the cleaning liquid.

By doing so, a regression line is obtained after excluding the pH value having a large noise component during non-operation of the cleaning equipment from the graph showing the transition of the pH value of the cleaning liquid in the cleaning tank, and the cleaning liquid in the cleaning tank is obtained. It is possible to predict the replacement time of. Therefore, according to the present invention, it is possible to predict with high accuracy the replacement time of the cleaning liquid of the alkaline solution used for the cleaning treatment such as the alkaline immersion degreasing treatment. In addition, since the sensor installed at a predetermined position in the cleaning tank can be always operated regardless of whether the cleaning equipment is operating or not, it does not affect the maintenance of the cleaning equipment.

FIG. 1 is a schematic view of a cleaning liquid exchange prediction system 1 according to an embodiment of the present invention. FIG. 2 is a diagram for explaining the transition of the pH value of the cleaning liquid 60 stored in the cleaning tank 61. FIG. 3 is a diagram for explaining the principle of predicting the replacement time of the cleaning liquid 60 by the cleaning liquid replacement prediction device 3. FIG. 4 is a schematic functional configuration diagram of the cleaning liquid exchange prediction device 3. FIG. 5 is a flow chart for explaining the replacement prediction timing calculation process of the cleaning liquid replacement prediction device 3. FIG. 6 is a flow chart for explaining the pH value stabilization standby time setting process of the cleaning liquid exchange prediction device 3. FIG. 7 is a diagram for explaining the principle of predicting the replacement time of the cleaning liquid 60 by a modification of the cleaning liquid replacement prediction device 3.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Here, a case where the present invention is applied to an alkaline immersion degreasing treatment facility will be given as an example.

FIG. 1 is a schematic view of a cleaning liquid exchange prediction system 1 according to the present embodiment.

The cleaning liquid exchange prediction system 1 according to the present embodiment predicts the replacement time of the cleaning liquid 60 in the alkaline immersion degreasing treatment equipment 6.

Here, the alkaline immersion degreasing treatment equipment 6 circulates the cleaning liquid 60 between the cleaning tank 61 in which the cleaning liquid 60 is stored, the filter 62 for removing impurities contained in the cleaning liquid 60, and the cleaning tank 61 and the filter 62. It includes a circulation pump 63 and a nozzle 64 that injects a part of the cleaning liquid 60 supplied to the cleaning tank 61 by the circulation pump 63 into the cleaning tank 61. In FIG. 1, the cleaning liquid 60 supplied to the cleaning tank 61 by the circulation pump 63 is supplied from the nozzle 64 into the cleaning tank 61 and into the cleaning tank 61 without going through the nozzle 64. Although it is branched into two supply systems, at least one of them may be provided. Further, as the cleaning liquid 60, a cleaning liquid of an alkaline solution to which a surfactant is added is used, if necessary. As a cleaning solution for such an alkaline solution, for example, there is a product "Nikka Sun Clean L Series" manufactured by NICCA CHEMICAL CO., LTD.

During the operation of the alkaline immersion degreasing treatment equipment 6, the cleaning liquid 60 stored in the cleaning tank 61 is removed from the cleaning tank 61 by the circulation pump 63, impurities are removed by the filter 62, and then returned to the cleaning tank 61. Therefore, the cleaning liquid 60 in the cleaning tank 61 is agitated, and the pH value of the cleaning liquid 60 in the cleaning tank 61 becomes uniform. On the other hand, when the alkaline immersion degreasing treatment equipment 6 is not in operation, the circulation pump 63 is stopped, so that the cleaning liquid 60 in the cleaning tank 61 is not agitated and the pH value of the cleaning liquid 60 in the cleaning tank 61 becomes non-uniform. ..

The cleaning liquid exchange prediction system 1 is installed at a predetermined position in the cleaning tank 61, sequentially measures the pH value of the cleaning liquid 60 stored in the cleaning tank 61, and sequentially outputs the measured value to which the measurement time is added. And an operation terminal 4 for operating the cleaning liquid exchange prediction device 3 and the cleaning liquid exchange prediction device 3.

The cleaning liquid exchange prediction device 3 and the operation terminal 4 are connected to a network 50 such as a LAN (Local Area Network). Further, the pH sensor 2 is connected to the network 50 via the wireless communication device 51 and the wireless AP (access point) 52. The wireless communication device 51 sequentially transmits the measured values sequentially output from the pH sensor 2 to the cleaning liquid exchange prediction device 3 via the wireless AP 52 and the network 50. Instead of the wireless communication device 51, a communication device that connects the pH sensor 2 to the network 50 by wire may be used.

The cleaning liquid exchange prediction device 3 receives the measured values sequentially output from the pH sensor 2 from the wireless communication device 51, and predicts the replacement time of the cleaning liquid 60 stored in the cleaning tank 61 based on the measured values. Then, the prediction result is transmitted to the operation terminal 4 and displayed.

As shown in FIG. 2, the present inventor shows that the pH value of the cleaning liquid 60 in the cleaning tank 61 decreases (reference numeral 10) during the operation of the alkaline immersion degreasing treatment equipment 6, while the alkaline immersion degreasing treatment equipment 6 has a pH value. It was found that it rises (reference numeral 11) during non-operation. Then, by repeating the operation and non-operation of the alkaline immersion degreasing treatment equipment 6, the pH value of the cleaning liquid 60 in the cleaning tank 61 gradually decreases as a whole with the passage of time while repeating the cycle of decrease and increase. I found that I would go (reference numeral 12).

Therefore, in the cleaning liquid exchange prediction device 3, first, as shown in FIG. 3, the pH value of the cleaning liquid 60 is sequentially measured after the cleaning liquid 60 is charged or replaced by the pH sensor 2 installed at a predetermined position in the cleaning tank 61. Are arranged in chronological order to specify a graph 13 showing the transition of the pH value of the cleaning liquid 60 after charging or replacement, and the change point of the sign of the slope of this graph 13 (the bottom side change point where the slope changes from minus to plus). 14 and the top change point 15) where the slope changes from plus to minus are extracted. Then, between the bottom side change point 14 and the top side change point 15 that appears next to the bottom side change point 14 (the bottom side change point 14 and the top side change point 15 that are adjacent to each other in this order). The measured value between the top side change point 15, that is, the section where the inclination is positive (measured value when the alkaline immersion degreasing treatment equipment 6 is not operating), and the pH value stabilization standby time from the top side change point 15. A filtering process is performed to remove the measured value included in the period (time required for the cleaning liquid 60 in the cleaning tank 61 to be sufficiently stirred and the pH value becomes uniform after the alkaline immersion degreasing treatment facility 6 is operated). do. Then, a regression line 16 is obtained from the graph 13 after the filtering process (graph 13 from which the measured value of the broken line portion is removed), and the pH value of the cleaning liquid 60 in the cleaning tank 61 is set to the cleaning liquid 60 using this regression line 16. A time when a predetermined threshold value 17 is reached as a pH value requiring replacement is calculated, and this time is set as a prediction time for replacement of the cleaning liquid 60.

FIG. 4 is a schematic functional configuration diagram of the cleaning liquid exchange prediction device 3.

As shown in the figure, the cleaning liquid exchange prediction device 3 includes a network interface unit 300, a measured value acquisition unit 301, a measured value storage unit 302, an operation reception unit 303, a change point extraction unit 304, and a filter unit 305. It has a regression line calculation unit 306, an exchange prediction time calculation unit 307, a pH value stabilization standby time calculation unit 308, and a main control unit 309.

The network interface unit 300 is an interface for connecting to the network 50.

The measured value acquisition unit 301 is a measured value (in the cleaning tank 61) with a measurement time sequentially output from the pH sensor 2 transmitted from the wireless communication device 51 to the cleaning liquid exchange prediction device 3 via the wireless AP 52 and the network 50. The pH value of the cleaning liquid 60) is acquired via the network interface unit 300.

The measured value storage unit 302 stores the measured values with the measured time, which are sequentially output from the pH sensor 2 acquired by the measured value acquisition unit 301.

The operation reception unit 303 receives various operations including a replacement time prediction operation and a pH value stabilization standby time setting operation from the operation terminal 4 via the network interface unit 300. Then, the processing result of the received operation is transmitted to the operation terminal 4 as needed.

The change point extraction unit 304 changes the pH value of the cleaning liquid 60 in the cleaning tank 61 within the period specified by the replacement time prediction operation or the pH value stabilization standby time setting operation received from the operation terminal 4 by the operation reception unit 303. 13 (graph 13 in which a plurality of measured values output by the pH sensor 2 are arranged in chronological order according to the measurement time added to these measured values) is specified, and the inclination of this graph 13 is from minus to plus. The bottom side change point 14 that changes to and the top side change point 15 that changes from plus to minus are extracted (see FIG. 3).

The filter unit 305 has a specific result by the change point extraction unit 304 (graph 13 showing the transition of the pH value of the cleaning liquid 60 in the cleaning tank 61, the bottom side change point 14, and the top side change point 15) and the pH value stabilization. According to the pH value stabilization standby time t calculated by the standby time calculation unit 308, between the bottom side change point 14 and the top side change point 15 appearing next to the bottom side change point 14 (bottom side change point 14). , The measured value (between the bottom side change point 14 and the top side change point 15 adjacent in time series in the order of the top side change point 15), and the period from the top side change point 15 to the pH value stabilization waiting time t. A filtering process is performed to remove the measured value contained in (see FIG. 3).

The regression line calculation unit 306 calculates the regression line 16 by, for example, the least squares method, using a plurality of measured values constituting the graph 13 after the filtering process by the filter unit 305.

The replacement prediction time calculation unit 307 uses the regression line 16 calculated by the regression line calculation unit 306 to predetermine the pH value of the cleaning liquid 60 in the cleaning tank 61 as the pH value requiring replacement of the cleaning liquid 60. The time when the threshold value 17 is reached is calculated as the predicted replacement time of the cleaning liquid 60 (see FIG. 3).

The pH value stabilization standby time calculation unit 308 cooperates with the change point extraction unit 304, the filter unit 305, the regression line calculation unit 306, and the exchange prediction time calculation unit 307, and the cleaning liquid calculated by the exchange prediction time calculation unit 307. The pH value stabilization standby time in which the time difference between the replacement prediction time of 60 and the actual replacement time specified in the pH value stabilization standby time setting operation received from the operation terminal 4 by the operation reception unit 303 is within a predetermined range. Calculate the time.

Then, the main control unit 309 comprehensively controls each unit 300 to 308 of the cleaning liquid exchange prediction device 3.

The functional configuration of the cleaning liquid exchange prediction device 3 shown in FIG. 4 may be realized by hardware such as an integrated logic IC such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), or a DSP. It may be realized by software by a computer such as (Digital Signal Processor). Alternatively, a PC having a CPU (Central Processing Unit), a memory, an auxiliary storage device such as an HDD (Hard Disk Drive) and an SSD (Solid State Drive), and a communication interface such as an NIC (Network Interface Card) ( In a general-purpose computer such as a personal computer), the CPU may load a predetermined program from an auxiliary storage device onto a memory and execute the program.

FIG. 5 is a flow chart for explaining the replacement prediction timing calculation process of the cleaning liquid replacement prediction device 3. In this flow, the operation reception unit 303 receives from the operation terminal 4 via the network interface unit 300 a replacement time prediction operation accompanied by designation of the latest replacement time or charging time of the cleaning liquid 60 stored in the cleaning tank 61. Is started by.

First, the operation reception unit 303 notifies the main control unit 309 of the latest exchange time or input time specified in the exchange time prediction operation, and requests the calculation of the exchange prediction time. In response to this, the main control unit 309 checks whether or not the pH value stabilization standby time t has been set (S100). If the pH value stabilization standby time t has not been set (NO in S100), the main control unit 309 notifies the operation reception unit 303 to that effect. In response to this, the operation reception unit 303 transmits a message to the operation terminal 4 via the network interface unit 300 that it is necessary to perform the pH value stabilization standby time calculation process prior to the exchange prediction time calculation process. (S107).

On the other hand, when the pH value stabilization standby time t has already been set (YES in S100), the main control unit 309 has the latest replacement time or after the input time received from the operation reception unit 303 from the measurement value storage unit 302. A plurality of measured values (pH values of the cleaning liquid 60 in the cleaning tank 61) to which the measurement time is added are read (S101). Then, the main control unit 309 passes a plurality of measured values read from the measured value storage unit 302 to the change point extraction unit 304, and instructs the change point extraction unit 304 to extract the change point. In response to this, as shown in FIG. 3, the change point extraction unit 304 adds a plurality of measured values to which the latest exchange time or the measurement time after the input time is added to these measured values. Arranged in chronological order according to time, a graph 13 showing the transition of the pH value of the cleaning liquid 60 in the cleaning tank 61 after replacement or after charging is specified, and the bottom side change point 14 and the top side change point 15 are extracted from this graph 13. (S102).

Next, the main control unit 309 sets the graph 13 specified by the change point extraction unit 304, the bottom side change point 14 and the top side change point 15 extracted by the change point extraction unit 304, in the filter unit 305. The filtering process is instructed by passing the pH value stabilization waiting time t, which has already been completed. In response to this, as shown in FIG. 3, the filter unit 305 is located between the bottom side change point 14 and the top side change point 15 that appears next to the bottom side change point 14 (bottom side change point 14, top). The measured values (between the bottom side change point 14 and the top side change point 15 adjacent in time series in the order of the side change points 15) (measured values when the alkaline immersion degreasing treatment equipment 6 is not operating) and the top side. The measured value included in the period from the change point 15 to the pH value stabilization standby time t (from the operation of the alkaline immersion degreasing treatment equipment 6 until the cleaning liquid 60 in the cleaning tank 61 is sufficiently stirred until the pH value becomes uniform. A filtering process for removing the measured value (measured value belonging to the time zone of S103) is performed (S103).

Next, the main control unit 309 tells the regression line calculation unit 306 that the graph 13 after the filtering process by the filter unit 305 (bottom side change point 14 and top side change point 15 are adjacent to the bottom side change point in the order of time series). The regression line calculation is performed by passing the measured value between 14 and the top side change point 15 and the graph 13) from which the measured value included in the period of the pH value stabilization waiting time t is removed from the top side change point 15. Instruct. In response to this, as shown in FIG. 3, the regression line calculation unit 306 calculates the regression line 16 by, for example, the least squares method, using a plurality of measured values constituting the graph 13 after the filtering process by the filter unit 305. (S104).

Next, the main control unit 309 passes the regression line 16 calculated by the regression line calculation unit 306 to the exchange prediction time calculation unit 307, and instructs the exchange prediction time calculation. In response to this, as shown in FIG. 3, the replacement prediction time calculation unit 307 uses the regression line 16 calculated by the regression line calculation unit 306 to set the pH value of the cleaning liquid 60 in the cleaning tank 61 to the cleaning liquid 60. The time when a predetermined threshold value 17 is reached as the pH value requiring replacement of the cleaning liquid 60 is calculated as the predicted replacement time of the cleaning liquid 60 (S105).

Next, the main control unit 309 passes the replacement prediction time of the cleaning liquid 60 calculated by the replacement prediction time calculation unit 307 to the operation reception unit 303. In response to this, the operation reception unit 303 transmits to the operation terminal 4 via the network interface unit 300 the replacement prediction time of the cleaning liquid 60 received from the main control unit 309 (S106).

FIG. 6 is a flow chart for explaining the pH value stabilization standby time setting process of the cleaning liquid exchange prediction device 3. In this flow, the operation reception unit 303 has the latest replacement time of the cleaning liquid 60 stored in the cleaning tank 61 from the operation terminal 4 via the network interface unit 300, and the previous replacement time (the latest replacement time is). In the case of the first time, it is started by accepting the pH value stabilization standby time setting operation accompanied by the designation (only the latest replacement time).

First, the operation reception unit 303 tells the main control unit 309 that the latest replacement time specified in the pH value stabilization standby time setting operation and the previous replacement time (the latest if the latest replacement time is the first time). Notify the replacement time) and request the calculation of the pH value stabilization standby time. In response to this, the main control unit 309 receives from the measured value storage unit 302 between the latest exchange time received from the operation reception unit 303 and the previous exchange time (the latest if only the latest exchange time is available). A plurality of measured values (pH value of the cleaning liquid 60 in the cleaning tank 61) to which the measurement time of (before the replacement time) is added are read (S110). Further, the main control unit 309 notifies the pH value stabilization standby time calculation unit 308 of the latest replacement time specified in the pH value stabilization standby time setting operation, and instructs the pH value stabilization standby time to be calculated. do. In response to this, the pH value stabilization standby time calculation unit 308 sets the temporary pH value stabilization standby time t'to "0" and the previous time difference to the initial value (for example, the value S used in S116) (S111). ..

Next, the main control unit 309 passes a plurality of measured values read from the measured value storage unit 302 to the change point extraction unit 304, and instructs the change point extraction unit 304 to extract the change point. In response to this, the change point extraction unit 304 adds a plurality of measured values to which the measurement time received from the main control unit 309 is added, as in the case of S102 in the exchange prediction time calculation process described above. A graph 13 showing the transition of the pH value of the cleaning liquid 60 in the cleaning tank 61 during the period between the latest replacement time and the previous replacement time is specified by arranging them in chronological order according to the measured measurement time. The bottom side change point 14 in which the inclination of is changed from minus to plus and the top side change point 15 in which the inclination of is changed from plus to minus are extracted (S112).

Then, the main control unit 309 tells the filter unit 305 that the graph 13 specified by the change point extraction unit 304, the bottom side change point 14 and the top side change point 15 extracted by the change point extraction unit 304, and the provisional pH. The value stabilization wait time t'and the filtering process are instructed by passing. In response to this, the filter unit 305 is between each bottom side change point 14 and the top side change point 15 that appears next to each bottom side change point 14 (bottom side change point 14, as in S103 of the exchange prediction time calculation process described above. Measured values (between the bottom side change point 14 and the top side change point 15 adjacent in time series in the order of the top side change point 15), and within the temporary pH value stabilization waiting time t'from the top side change point 15. Performs a filtering process for removing the measured value contained in (S113).

Next, the main control unit 309 tells the regression line calculation unit 306 that the graph 13 after the filtering process by the filter unit 305 (bottom side change point 14 and top side change point 15 are adjacent to the bottom side change point in the order of time series). Regression line calculation by passing the measured value between 14 and the top side change point 15 and the graph 13) from which the measured value included in the provisional pH value stabilization waiting time t'is removed from the top side change point 15. To instruct. In response to this, the regression line calculation unit 306 uses, for example, a least squares method using a plurality of measured values constituting the graph 13 after the filtering process by the filter unit 305, as in the case of S104 of the exchange prediction timing calculation process described above. The regression line 16 is calculated by (S114).

Then, the main control unit 309 passes the regression line 16 calculated by the regression line calculation unit 306 to the exchange prediction time calculation unit 307, and instructs the exchange prediction time calculation. In response to this, the exchange prediction time calculation unit 307 uses the regression line 16 calculated by the regression line calculation unit 306 in the same manner as in S105 of the exchange prediction time calculation process described above, to use the cleaning liquid 60 in the cleaning tank 61. The time when the pH value reaches a predetermined threshold value 17 as the pH value requiring replacement of the cleaning liquid 60 is calculated as the replacement prediction time T of the cleaning liquid 60 (S115).

Next, the main control unit 309 notifies the pH value stabilization standby time calculation unit 308 of the exchange prediction time T calculated by the exchange prediction time calculation unit 307. In response to this, the pH value stabilization standby time calculation unit 308 has the exchange prediction time T calculated by the exchange prediction time calculation unit 307 and the latest exchange time T0 specified in the pH value stabilization standby time setting operation. The time difference with and from is calculated, and it is examined whether or not this time difference (T-T0) is within a predetermined range (for example, -S <T-T0 <S) (S116). When this time difference is not within the predetermined range (NO in S116), the pH value stabilization standby time calculation unit 308 adds the predetermined value a to the provisional pH value stabilization standby time t', and this added value (t'). + A) is set as a new temporary pH value stabilization standby time t'(S118), and the process returns to step S113.

If this time difference is within a predetermined range (YES in S116) and this time difference is smaller than the previously calculated time difference (YES in S117), the pH value stabilization standby time calculation unit 308 is provisionally A predetermined value a is added to the pH value stabilization standby time t', this added value (t'+ a) is set as a new provisional pH value stabilization standby time t'(S118), and the process returns to step S113. On the other hand, if this time difference is the same as or greater than the previously calculated time difference (NO in S117), the pH value stabilization standby time calculation unit 308 is set to a predetermined value from the temporary pH value stabilization standby time t'. The value obtained by subtracting a is the pH value stabilization standby time t, which is the time required from the operation of the alkaline immersion degreasing treatment equipment 6 until the cleaning liquid 60 in the cleaning tank 61 is sufficiently agitated and the pH value becomes uniform. (S119).

The embodiment of the present invention has been described above.

As described above, as shown in FIG. 2, the present inventor shows that the pH value of the cleaning liquid 60 in the cleaning tank 61 decreases (reference numeral 10) while the alkaline immersion degreasing treatment equipment 6 is in operation, while the alkaline immersion is performed. It has been found that the amount increases (reference numeral 11) when the degreasing treatment equipment 6 is not in operation. Then, by repeating the operation and non-operation of the alkaline immersion degreasing treatment equipment 6, the pH value of the cleaning liquid 60 in the cleaning tank 61 gradually decreases as a whole with the passage of time while repeating the cycle of decrease and increase. I found that I would go (reference numeral 12).

Therefore, in the present embodiment, as shown in FIG. 3, the pH values of the cleaning liquid 60 measured sequentially after the replacement or charging of the cleaning liquid 60 by the pH sensor 2 installed at a predetermined position in the cleaning tank 61 are measured in chronological order. A graph 13 showing the transition of the pH value of the cleaning liquid 60 after replacement or after charging is specified, and the bottom side change point 14 and the top side change point 15 of this graph 13 are extracted. Then, in the direction of the time axis, a filtering process is performed to remove the measured value between the bottom side change point 14 and the top side change point 15 arranged in the order of the bottom side change point 14 and the top side change point 15. The regression line 16 is obtained from the graph 13 after the filtering process. Further, using this regression line 16, the time when the pH value of the cleaning liquid 60 in the cleaning tank 61 reaches a predetermined threshold value 17 as the pH value requiring replacement of the cleaning liquid 60 is defined as the replacement prediction time of the cleaning liquid 60. It is calculated.

As described above, in the present embodiment, the pH value having a large noise component during non-operation of the alkaline immersion degreasing treatment equipment 6 is excluded from the graph 13 showing the transition of the pH value of the cleaning liquid 60 in the cleaning tank 61. Since the regression line 16 can be obtained and the replacement time of the cleaning liquid 60 can be predicted, the replacement time of the cleaning liquid 60 in the cleaning tank 61 can be predicted with high accuracy. Further, since the pH sensor 2 installed at a predetermined position in the cleaning tank 61 can be constantly operated regardless of whether the alkaline immersion degreasing treatment equipment 6 is operating or not, it does not affect the maintenance of the alkaline immersion degreasing treatment equipment 6.

Further, in the present embodiment, in the filtering process, as shown in FIG. 3, the order of the bottom side change point 14 and the top side change point 15 is from the graph 13 showing the transition of the pH value of the cleaning liquid 60 in the cleaning tank 61. In addition to the measured values between the adjacent bottom side change points 14 and the top side change points 15, the measured values included in the period of the pH value stabilization waiting time t from the top side change points 15 are also removed. Therefore, from the graph 13 showing the transition of the pH value of the cleaning liquid 60 in the cleaning tank 61, the cleaning liquid 60 in the cleaning tank 61 is sufficiently agitated after the alkaline immersion degreasing treatment equipment 6 is operated, and the pH value becomes uniform. Since the regression line 16 can be obtained by excluding the pH value having a large noise component up to, the replacement time of the cleaning liquid 60 in the cleaning tank 61 can be predicted with higher accuracy.

Further, in the present embodiment, the estimated replacement time of the cleaning liquid 60 is calculated using the temporary pH value stabilization standby time t', and the time difference between the calculated replacement prediction time of the cleaning liquid 60 and the actual replacement time of the cleaning liquid 60. The temporary pH value stabilization standby time t'is changed until is within the predetermined range, and the temporary pH value stabilization standby time t'where this time difference is within the predetermined range is set as the pH value stabilization standby time t. .. Therefore, the pH value stabilization standby time t, which is the time from the operation of the alkaline immersion degreasing treatment equipment 6 until the cleaning liquid 60 in the cleaning tank 61 is sufficiently agitated and the pH value becomes uniform, is set more accurately. be able to.

The present invention is not limited to the above embodiment, and many modifications can be made within the scope of the gist thereof.

For example, in the cleaning liquid exchange prediction device 3, the filter unit 305 has a pH value stabilization standby time t starting from the top side change point 15 with respect to all the top side change points 15 extracted by the change point extraction unit 304. As a result, the filtering process is carried out by commonly using the pH value stabilization standby time t calculated by the pH value stabilization standby time calculation unit 308. However, the present invention is not limited to this. The pH value stabilization standby time t may be changed for each top-side change point 15 extracted by the change-point extraction unit 304, starting from the top-side change point 15.

For example, in the pH value stabilization standby time setting process shown in FIG. 6, for each top-side change point 15 extracted by S112, this top-side change from the bottom-side change point 14 extracted immediately before the top-side change point 15. The increase value h up to the point 15 is obtained (see FIG. 3), the average value thereof is used as the reference increase value hs, and the pH value stabilization standby time t set in S119 is used as the reference pH value stabilization standby time ts. And.

Next, in the exchange prediction timing calculation process of FIG. 5, for each top-side change point 15 extracted by S102, from the bottom-side change point 14 extracted immediately before the top-side change point 15 to the top-side change point 15. The rising value h of the above is obtained (see FIG. 3), and the obtained rising value h is associated with the top side change point 15. Then, in S103, the filter unit 305 sets the reference pH value stabilization standby time ts for each top-side change point 15 extracted by the change-point extraction unit 304, and the increase value h associated with the top-side change point 15. The filtering process is performed by using the value (t = ts (h / hs)) corrected by the ratio h / hs of the reference rise value hs as the pH value stabilization standby time t starting from the top side change point 15. implement.

Alternatively, in the pH value stabilization standby time setting process shown in FIG. 6, for each top-side change point 15 extracted by S112, this top-side change from the bottom-side change point 14 extracted immediately before the top-side change point 15. The elapsed time m to the point 15 is obtained (see FIG. 3), the average value thereof is set as the reference elapsed time ms, and the pH value stabilization standby time t set in S119 is used as the reference pH value stabilization standby time ts. And.

Next, in the exchange prediction timing calculation process of FIG. 5, for each top-side change point 15 extracted by S102, from the bottom-side change point 14 extracted immediately before the top-side change point 15 to the top-side change point 15. The elapsed time m of the above is obtained (see FIG. 3), and the obtained elapsed time m is associated with the top side change point 15. Then, in S103, the filter unit 305 sets the reference pH value stabilization standby time ts for each top-side change point 15 extracted by the change point extraction unit 304, and the elapsed time m associated with the top-side change point 15. The filtering process is performed by using the value (t = ts (m / ms)) corrected by the ratio m / ms of the reference elapsed time ms as the pH value stabilization standby time t starting from the top side change point 15. implement.

According to the present inventor, the longer the period in which the cleaning liquid 60 stored in the cleaning tank 61 is not stirred (the non-operating period of the alkaline immersion degreasing treatment equipment 6) continues, the higher the pH value of the cleaning liquid 60 in the cleaning tank 61 becomes, and the more alkaline. It has been found that after the immersion degreasing treatment equipment 6 is operated, the time required for the cleaning liquid 60 in the cleaning tank 61 to be sufficiently stirred and the pH value of the cleaning liquid 60 in the cleaning tank 61 becomes uniform becomes long.

Therefore, as described above, in the filtering process, for each top-side change point 15 extracted from the graph 13 showing the transition of the pH value of the cleaning liquid 60 in the washing tank 61, the pH value starting from the top-side change point 15. As the stabilization standby time t, the reference pH value stabilization standby time ts is set as the increase value h and the reference increase value from the bottom side change point 14 extracted immediately before the top side change point 15 to the top side change point 15. A value corrected by the ratio h / hs with hs (t = ts (h / hs)), or from the bottom side change point 14 extracted immediately before the top side change point 15 to this top side change point 15. By using a value (t = ts (m / ms)) corrected by the ratio m / ms of the elapsed time m and the reference elapsed time ms, the cleaning liquid in the cleaning tank 61 after the alkaline immersion degreasing treatment equipment 6 is operated. The regression line 16 can be obtained by more reliably excluding the pH value having a large noise component until the pH value of the cleaning liquid 60 in the cleaning tank 61 becomes uniform after the 60 is sufficiently stirred. Therefore, the replacement time of the cleaning liquid 60 in the cleaning tank 61 can be predicted with higher accuracy.

Further, in the cleaning liquid exchange prediction device 3, as shown in FIG. 3, the filter unit 305 has a bottom side change point 14 and a top side change point 15 from the graph 13 showing the transition of the pH value of the cleaning liquid 60 in the cleaning tank 61. Filtering process to remove the measured value between the adjacent bottom side change point 14 and the top side change point 15 and the measured value included in the period of the pH value stabilization waiting time t from the top side change point 15 in the order of. Is being carried out. However, the present invention is not limited to this.

For example, as shown in FIG. 7, in the graph 13 showing the transition of the pH value of the cleaning liquid 60 in the cleaning tank 61, the filter unit 305 is used for each bottom side change point 14 and after the bottom side change point 14. From the measured values included between the side change point 14 and the bottom side change point 14, the measured value having a pH value higher than the pH value x of the bottom side change point 14 (measured value in the broken line portion) is removed. You may carry out the filtering process.

Even in this case, from the graph 13 showing the transition of the pH value of the cleaning liquid 60 in the cleaning tank 61, the pH value having a large noise component including the pH value measured during the non-operation of the alkaline immersion degreasing treatment equipment 6 can be obtained. Since the regression line 16 can be obtained by excluding it, the replacement time of the cleaning liquid 60 in the cleaning tank 61 can be predicted with high accuracy using this regression line 16. In this case, the change point extraction unit 304 may extract only the bottom side change point 14 from the graph 13 showing the transition of the pH value of the cleaning liquid 60 in the cleaning tank 61. Further, since the pH value stabilization waiting time t is not used in the filtering process, the exchange prediction timing calculation processes S100 and S107 shown in FIG. 5 and the pH value stabilization time waiting process shown in FIG. 6 are not required. Therefore, the configuration of the cleaning liquid exchange prediction device 3 can be simplified by omitting the pH value stabilization standby time calculation unit 308.

Further, in the above embodiment, the measured value acquisition unit 301 and the measured value storage unit 302 are omitted from the cleaning liquid exchange prediction device 3, and the measured value acquisition unit 301 and the measured value storage unit are separated from the cleaning liquid exchange prediction device 3. A database with 302 may be prepared. Then, in the cleaning liquid exchange prediction device 3, the main control unit 309 may access the database via the network interface unit 300 and acquire the required measured value from the measured value storage unit 302. Further, the cleaning liquid exchange prediction device 3 may be integrated with the operation terminal 4.

1: Cleaning liquid exchange prediction system 2: pH sensor 3: Cleaning liquid exchange prediction device 4: Operation terminal 6: Alkaline immersion degreasing treatment equipment 50: Network 51: Wireless communication device 52: Wireless AP 60: Cleaning liquid 61: Cleaning tank 62: Filter 63 : Circulation pump 64: Nozzle 300: Network interface unit 301: Measurement value acquisition unit 302: Measurement value storage unit 303: Operation reception unit 304: Change point extraction unit 305: Filter unit 306: Regression straight line calculation unit 307: Replacement prediction timing calculation Unit 308: pH value stabilization standby time calculation unit 309: Main control unit

Claims (10)

A cleaning tank in which a cleaning liquid of an alkaline solution to which a surfactant is added as needed is stored, a filter for removing impurities contained in the cleaning liquid, and a circulation pump for circulating the cleaning liquid between the cleaning tank and the filter. It is a cleaning liquid exchange prediction device that predicts the exchange time of the cleaning liquid in the cleaning equipment provided with
A measurement value acquisition means for acquiring the pH value of the cleaning liquid sequentially measured by a sensor installed at a predetermined position in the cleaning tank together with the measurement time.
The pH value of the cleaning liquid in the cleaning tank obtained by arranging the pH values of the cleaning liquid acquired by the measured value acquisition means in chronological order in the order of the measurement time after the cleaning liquid is charged into the cleaning tank or after replacement. A change point extraction means for extracting the bottom side change point where the slope of the graph showing the transition of the change from minus to plus and the top side change point where the slope changes from plus to minus,
For each bottom-side change point extracted by the change point extraction means, a measurement between the bottom-side change point and the top-side change point extracted by the change point extraction means following the bottom-side change point. A filtering means that performs a filtering process for removing the value from the graph,
A regression line calculation means for calculating a regression line from the graph on which the filtering process is performed by the filter means, and a regression line calculation means.
Using the regression line calculated by the regression line calculation means, the time when the pH value of the cleaning liquid reaches a predetermined threshold value as the pH value requiring replacement of the cleaning liquid in the cleaning tank is set. Exchange prediction time calculation means to calculate as the exchange prediction time of
A cleaning liquid exchange prediction device comprising: an exchange prediction time output means for outputting the exchange prediction time of the cleaning liquid calculated by the exchange prediction time calculation means. The cleaning liquid exchange prediction device according to claim 1.
The filter means
In the filtering process, the measured value included in the period from the top-side change point to the elapse of the predetermined pH value stabilization waiting time for each top-side change point extracted by the change point extraction means is also described. A cleaning fluid exchange predictor characterized by removing from the graph. The cleaning liquid exchange prediction device according to claim 2.
A pH value stabilization standby time determining means for determining the pH value stabilization standby time by using the exchange prediction timing of the cleaning liquid calculated by the replacement prediction timing calculation means and the actual replacement timing of the cleaning liquid. Have more
The means for determining the pH value stabilization standby time is
A preset temporary value is set in the pH value stabilization standby time, the replacement prediction time of the cleaning liquid is calculated by the replacement prediction time calculation means, and the calculated replacement prediction time of the cleaning liquid and the actual cleaning liquid are calculated. The cleaning liquid exchange is characterized in that the provisional value is changed until the time difference from the replacement time is within a predetermined range, and the provisional value within which the time difference is within a predetermined range is determined as the pH value stabilization standby time. Predictor. The cleaning liquid exchange prediction device according to claim 3.
The means for determining the pH value stabilization standby time is
In the graph filtered by the filter means with the tentative value in which the time difference is within a predetermined range as the pH value stabilization standby time, for each of the top-side change points extracted by the change point extraction means. The increase value from the bottom side change point extracted immediately before the top side change point to the top side change point is calculated, and the average value of the increase values is used as the reference increase value.
The filter means
For each top-side change point extracted by the change point extraction means, the pH value stabilization waiting time following the top-side change point was extracted immediately before the top-side change point by the change point extraction means. A cleaning liquid exchange prediction device characterized in that correction is made according to the ratio of the rise value from the bottom side change point to the top side change point and the reference rise value. A cleaning tank in which a cleaning liquid of an alkaline solution to which a surfactant is added as needed is stored, a filter for removing impurities contained in the cleaning liquid, and a circulation pump for circulating the cleaning liquid between the cleaning tank and the filter. It is a cleaning liquid exchange prediction device that predicts the exchange time of the cleaning liquid in the cleaning equipment provided with
A measurement value acquisition means for acquiring the pH value of the cleaning liquid sequentially measured by a sensor installed at a predetermined position in the cleaning tank together with the measurement time.
The pH value of the cleaning liquid in the cleaning tank obtained by arranging the pH values of the cleaning liquid acquired by the measured value acquisition means in chronological order in the order of the measurement time after the cleaning liquid is charged into the cleaning tank or after replacement. A change point extraction means for extracting the bottom side change point where the slope of the graph showing the transition changes from minus to plus,
For each bottom-side change point extracted by the change point extraction means, among the measured values included between the bottom-side change point and the next bottom-side change point of the bottom-side change point, the bottom-side change. A filter means for performing a filtering process for removing the measured value of the pH value higher than the point from the graph showing the transition of the pH value of the cleaning liquid.
A regression line calculation means for calculating a regression line from the graph on which the filtering process is performed by the filter means, and a regression line calculation means.
Using the regression line calculated by the regression line calculation means, the time when the pH value of the cleaning liquid reaches a predetermined threshold value as the pH value requiring replacement of the cleaning liquid in the cleaning tank is set. Exchange prediction time calculation means to calculate as the exchange prediction time of
A cleaning liquid exchange prediction device comprising: an exchange prediction time output means for outputting the exchange prediction time of the cleaning liquid calculated by the exchange prediction time calculation means. A cleaning tank in which a cleaning liquid of an alkaline solution to which a surfactant is added as needed is stored, a filter for removing impurities contained in the cleaning liquid, and a circulation pump for circulating the cleaning liquid between the cleaning tank and the filter. It is a cleaning liquid exchange prediction system that predicts the replacement time of the cleaning liquid in the cleaning equipment equipped with the above.
The cleaning liquid exchange prediction device according to any one of claims 1 to 5.
A sensor installed at a predetermined position in the cleaning tank, sequentially measuring the pH value of the cleaning liquid stored in the cleaning tank, and sequentially outputting the measured value to which the measurement time is added.
A cleaning liquid exchange prediction system comprising: a communication device sequentially output from the sensor and transmitting the measured value to which the measurement time is added to the cleaning liquid exchange prediction device. A cleaning tank in which a cleaning liquid of an alkaline solution to which a surfactant is added as needed is stored, a filter for removing impurities contained in the cleaning liquid, and a circulation pump for circulating the cleaning liquid between the cleaning tank and the filter. It is a cleaning liquid replacement prediction method for predicting the replacement time of the cleaning liquid in the cleaning equipment provided with the above.
The pH value of the cleaning liquid, which was sequentially measured by a sensor installed at a predetermined position in the cleaning tank, was acquired together with the measurement time.
The slope of the graph showing the transition of the pH value of the cleaning liquid in the cleaning tank, which is obtained by arranging the pH values of the cleaning liquid obtained after charging the cleaning liquid into the cleaning tank or after replacement in chronological order based on the measurement time. Extract the bottom side change point where is changing from minus to plus and the top side change point where is changing from plus to minus.
For each of the extracted bottom-side change points, a filtering process is performed to remove the measured value between the bottom-side change point and the extracted top-side change point following the bottom-side change point from the graph.
A regression line is calculated from the graph on which the filtering process is performed, and the regression line is calculated.
Using the calculated regression line, the time when the pH value of the cleaning liquid reaches a predetermined threshold value as the pH value requiring replacement of the cleaning liquid in the cleaning tank is calculated as the predicted replacement time of the cleaning liquid. A cleaning liquid exchange prediction method characterized by outputting. A cleaning tank in which a cleaning liquid of an alkaline solution to which a surfactant is added as needed is stored, a filter for removing impurities contained in the cleaning liquid, and a circulation pump for circulating the cleaning liquid between the cleaning tank and the filter. It is a cleaning liquid replacement prediction method for predicting the replacement time of the cleaning liquid in the cleaning equipment provided with the above.
The pH value of the cleaning liquid, which was sequentially measured by a sensor installed at a predetermined position in the cleaning tank, was acquired together with the measurement time.
The slope of the graph showing the transition of the pH value of the cleaning liquid in the cleaning tank, which is obtained by arranging the pH values of the cleaning liquid obtained after charging the cleaning liquid into the cleaning tank or after replacement in chronological order based on the measurement time. Extract the bottom side change point where is changing from minus to plus,
For each of the extracted bottom-side change points, the measurement of the pH value higher than the bottom-side change point among the measured values included between the bottom-side change point and the next bottom-side change point of the bottom-side change point. A filtering process is performed to remove the value from the graph.
A regression line is calculated from the graph on which the filtering process is performed, and the regression line is calculated.
Using the calculated regression line, the time when the pH value of the cleaning liquid reaches a predetermined threshold value as the pH value requiring replacement of the cleaning liquid in the cleaning tank is calculated as the predicted replacement time of the cleaning liquid. A cleaning liquid exchange prediction method characterized by outputting. A program that can be executed on a computer
The program is the computer.
A cleaning tank in which a cleaning liquid of an alkaline solution to which a surfactant is added as needed is stored, a filter for removing impurities contained in the cleaning liquid, and a circulation pump for circulating the cleaning liquid between the cleaning tank and the filter. To function as a cleaning liquid replacement predictor that predicts the replacement time of the cleaning liquid in a cleaning facility equipped with
The cleaning liquid exchange prediction device is according to the program.
A measured value acquisition means for acquiring the pH value of the cleaning liquid sequentially measured by a sensor installed at a predetermined position in the cleaning tank together with the measurement time.
The pH value of the cleaning liquid in the cleaning tank obtained by arranging the pH values of the cleaning liquid acquired by the measured value acquisition means in chronological order in the order of the measurement time after the cleaning liquid is charged into the cleaning tank or after replacement. A change point extraction means that extracts the bottom side change point where the slope of the graph showing the transition of the change from minus to plus and the top side change point where the slope changes from plus to minus.
For each bottom-side change point extracted by the change point extraction means, a measurement between the bottom-side change point and the top-side change point extracted by the change point extraction means following the bottom-side change point. A filter means that performs a filtering process that removes values from the graph.
A regression line calculation means for calculating a regression line from the graph on which the filtering process is performed by the filter means.
Using the regression line calculated by the regression line calculation means, the time when the pH value of the cleaning liquid reaches a predetermined threshold value as the pH value requiring replacement of the cleaning liquid in the cleaning tank is set. A program characterized by functioning as an exchange prediction time calculation means calculated as an exchange prediction time and an exchange prediction time output means for outputting the exchange prediction time of the cleaning liquid calculated by the exchange prediction time calculation means. A program that can be executed on a computer
The program is the computer.
A cleaning tank in which a cleaning liquid of an alkaline solution to which a surfactant is added as needed is stored, a filter for removing impurities contained in the cleaning liquid, and a circulation pump for circulating the cleaning liquid between the cleaning tank and the filter. To function as a cleaning liquid replacement predictor that predicts the replacement time of the cleaning liquid in a cleaning facility equipped with
The cleaning liquid exchange prediction device is according to the program.
A measured value acquisition means for acquiring the pH value of the cleaning liquid sequentially measured by a sensor installed at a predetermined position in the cleaning tank together with the measurement time.
The pH value of the cleaning liquid in the cleaning tank obtained by arranging the pH values of the cleaning liquid acquired by the measured value acquisition means in chronological order in the order of the measurement time after the cleaning liquid is charged into the cleaning tank or after replacement. Change point extraction means for extracting the bottom side change point where the slope of the graph showing the transition of
For each bottom-side change point extracted by the change point extraction means, the bottom-side change point is taken from the measured value included between the bottom-side change point and the next bottom-side change point of the bottom-side change point. A filter means that performs a filtering process to remove a measured value of a higher pH value from the graph.
A regression line calculation means for calculating a regression line from the graph on which the filtering process is performed by the filter means.
Using the regression line calculated by the regression line calculating means, the time at which the pH value of the cleaning liquid becomes a predetermined threshold value as the pH value requiring replacement of the cleaning liquid in the cleaning tank is set. A program characterized by functioning as a replacement prediction timing calculation means calculated as a replacement prediction timing of a cleaning liquid and a replacement prediction timing output means for outputting the replacement prediction timing of the cleaning liquid calculated by the replacement prediction timing calculation means.

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