JP5324312B2 - Measuring method of fluid weight in tank - Google Patents

Description

  The present invention is an improvement of the weight measuring method, more specifically, it is possible to continuously measure fluids such as paint in the tank of the coating apparatus in which the capacity is constantly changing, and even if discharging and replenishment are performed simultaneously. The present invention relates to a method for measuring a fluid weight in a tank that can be accurately measured with little error.

  In order to continuously apply liquid raw materials (coating liquids) such as paint, ink, petroleum, adhesives, etc. to the surface of the sheet material, mechanical work using a coating device is performed. For example, in order to maintain a stable coating accuracy by immersing a plate roll for coating a liquid material in an ink plate and maintaining a stable coating accuracy, the liquid surface height of the liquid material filled in the ink plate is used. The liquid raw material overflowed from the ink tray is collected in a container called a sub tank, and the liquid raw material is recirculated from the sub tank to the ink tray. The sub tank is appropriately replenished from an external supply tank.

  Then, the sheet material is passed between the rotated plate roll and the press roll, and the liquid material adhering to the plate roll is transferred and applied to the surface of the sheet material.

  As described above, when the liquid material is circulated between the sub tank and the supply tank, the liquid material is replenished from the supply tank in this sub tank, while the liquid material is sequentially consumed by the coating operation. Since there is an inflow of liquid raw material that overflows and returns from the tank, the amount of liquid in the tank is constantly changing in a complicated manner, and there is a problem that it is difficult to stabilize the value measured by the weigh scale.

  In the conventional coating apparatus, in order to measure the amount of the liquid material applied to the sheet material, every predetermined length of the sheet material applied and processed by traveling at a constant speed is used as a reference for the measurement timing, that is, at a predetermined time interval. Each time, we measure the weight of the liquid raw material in the sub-tank, calculate the liquid raw material decrease by the difference between the current measurement value and the previous measurement value, and divide by the sheet area (processing distance x processing width) to calculate the coating amount. It was calculating (for example, refer patent document 1).

  However, in the conventional measurement method, since the reference of the measurement timing is the travel distance of the sheet material, the measurement time interval is long and the time lag is large. When a decrease factor occurs at the same time, there is a problem that it is difficult to find an abnormality.

  Therefore, if the measured value of the application amount shows an abnormality, it is necessary to wait until the next application amount is confirmed in order to determine whether this is a temporary disturbance applied to the scale. Therefore, since it takes time to determine when there is an abnormality, the product processed during that time may be defective.

Japanese Patent No. 2780378

  The present invention has been made in view of the above-described problems in the conventional measurement method, and the object of the present invention is to provide a coating material in a tank of a coating apparatus in which the amount of storage varies every moment. It is an object of the present invention to provide a method for measuring the weight of a fluid in a tank that can continuously measure a fluid such as the above, and can accurately measure even if the fluid is discharged or replenished at the same time.

  Means employed by the present inventor for solving the above-described problems will be described with reference to the accompanying drawings.

That is, according to the present invention, in the tank 1 in which fluid F having fluidity such as liquid or granular material is accommodated and discharged quantitatively per unit time, the weight of the fluid F that fluctuates in the tank 1 is weighted. It is a method of continuous measurement management by a total of 2,
An actual weight value W (W ₁ · W ₂ (W ₁ is the latest)) obtained by measuring the weight of the fluid F in the tank 1 at predetermined time intervals by the weighing scale 2 is transmitted as a data signal,
N actual weight values W (W ₁ · W ₂ ... W _N ) are accumulated to form an actual weight value group WA. The actual weight value group WA is added each time the latest actual weight value W1 is added. While erasing W _{N + 1} holds N numbers and updates them sequentially and records them in the memory means 3,
Each time the actual weight value group WA is updated, the arithmetic means 4 averages the average weight value A (A ₁ · A ₂ ... (A ₁ is the latest) by the moving average process based on the actual weight value group WA. )) One after another,
K pieces (<N) of actual weight values W (W ₁ · W ₂ ... W _K ) are accumulated to constitute a trend determination actual weight value group WJ. Each time the measured weight value W ₁ is added, K numbers are retained by deleting W _{K + 1} and sequentially updated.
Each time the trend determination actual weight value group WJ is updated, the arithmetic means 4 performs averaging by the moving average process based on the trend determination actual weight value group WJ, and the trend determination short-term average value J (J ₁ · J ₂ (J ₁ is the latest))
The magnitude of the latest calculated value J ₁ and the unit time T value J _T calculated before this trend determination short term average value J by comparison operation tendency determination unit 5, these values difference (J ₁ -J _T ) As an increase / decrease determination value P, when the increase / decrease determination value P is negative, it is determined that the weight of the fluid F in the tank 1 is decreasing, and the latest measured weight value W ₁ is determined as the actually measured weight value. In addition to the group WA, recording in the memory means 3 is continued, and the calculation means 4 calculates the average weight value A,
When the increase / decrease determination value P becomes positive, it is determined that the weight of the fluid F in the tank 1 has changed from a decreasing tendency to an increasing tendency, and the latest measured weight value W1 is recorded in the memory means 3. Stop,
Then, the turned value of decrease determination value P is negative, when turned to decrease from the increase trend, starts the adding the latest measured weight values W ₁ to the measured weight value group WA again, Resuming recording to the memory means 3,
While reading from the memory means 3 of N content of measured weight value group back to front from recorded immediately before stopping measured weight value W _E immediately before the recording stop period to the memory unit 3 as a retrospective measured weight value group WR ,
Wherein immediately after recording resumption immediately after resumption measured weight value W _S by calculating the difference value V between the stop just before the measured weight value W _E, retrospectively measured weight value group WR to the difference value V is read from the memory means 3 A virtual retroactively measured weight value group WR ′ is formed by adding to each of the N numerical values in
As value of said resume immediately measured weight value W _S and immediately before stop measured weight value W _E match, the virtual retrospective measured weight value group WR 'in blank places in the recording stop period to the memory means 3 Employing technical means to retain N numerical values in the weight value group that is the basis of calculation by retroactively complementing, and to resume construction of the actually measured weight value group WA and calculate the average weight value A Thus, a method for measuring the weight of fluid in the tank was completed.

  Further, in order to solve the above-described problems, the present invention employs technical means that the number N of actually measured weight values W accumulated in the actually measured weight value group WA is 1000 or more in addition to the above means as necessary. .

  Furthermore, in order to solve the above-described problems, the present invention adds the number K of the actually measured weight values W accumulated in the tendency determining actual weight value group WJ to the actual weight value group WA in addition to the above means as necessary. The technical means of reducing the number N of the actually measured weight values W to be 1/20 or less was adopted.

  Furthermore, in order to solve the above-described problems, the present invention employs technical means in which a circulating structure is formed by providing an inflow device 11 for the fluid F in the tank 1 in addition to the above means as necessary. .

  Furthermore, in order to solve the above-mentioned problems, the present invention employs technical means for displaying the numerical value of the average weight value A on the display means 6 in addition to the above means as necessary.

  Furthermore, in order to solve the above-described problems, the present invention employs technical means for converting the fluid F to be measured into a liquid in addition to the above means as necessary.

  In the present invention, an actual weight value obtained by measuring the weight of the fluid in the tank at a predetermined time interval by a weight meter is transmitted as a data signal, and N actual weight values are accumulated to be an actual weight value group. The average weight value is calculated one after another by averaging by moving average processing, and the actual weight value group for trend determination is constructed by accumulating K (<N) actual weight values, for the trend determination The short-term average value for trend determination is calculated one after another by moving average processing based on the measured weight value group. By adopting this short-term average value for trend determination, it is easy just to collect data of short measurement time In addition, since the increase / decrease tendency of the fluid can be grasped, it is possible to perform quick and accurate control and management.

  Further, if the measurement method of the present invention is applied to a coating apparatus, it becomes possible to continuously measure the amount of coating and the increase / decrease of the paint, so that the operator can quickly know the amount of coating and the amount of defective products generated. In addition, the amount of coating can be accurately measured and the quality can be stabilized, so that it is particularly useful in the field of applying a liquid to a sheet, and the practical utility value in fluid management is low. There is something expensive.

It is explanatory drawing schematic of the coating device using the measuring method of embodiment of this invention. It is a flowchart showing the procedure of the measuring method of embodiment of this invention. It is a graph showing the measured weight value of the measuring method of the embodiment of the present invention. It is a graph showing the procedure of the moving average process in the measuring method of embodiment of this invention. It is a graph showing the average weight value before the process of the measuring method of embodiment of this invention. It is a graph showing the short-term average value for tendency judgment of the measuring method of the embodiment of the present invention. It is a graph showing the process of the measuring method of embodiment of this invention. It is a graph showing the average weight value after the process of the measuring method of embodiment of this invention.

  The mode for carrying out the present invention will be described in more detail with reference to the drawings specifically illustrated as follows.

  An embodiment of the present invention will be described with reference to FIGS. The measurement method of the present embodiment is particularly suitable for use in an apparatus that applies an adhesive or the like to the surface of a sheet material S as shown in FIG. In the figure, what is indicated by reference numeral 1 is a tank. The tank 1 is a bottomed container and contains a fluid F (liquid in this embodiment) having fluidity such as a liquid or a granular material. The fluid F can be quantitatively discharged per unit time.

  In the present embodiment, a fixed amount is discharged to an ink tray of a coating apparatus via a pump, and a fluid F inflow device 11 is provided in the tank 1 to form a circulation structure. The inflow device 11 may be an overflow from the ink tray and may or may not be powered. Further, the consumed fluid F can be appropriately supplied from the supply device 12.

  Also, what is indicated by reference numeral 2 is a weigh scale, and this weight scale 2 measures the weight of the fluid F accommodated in the tank 1 at predetermined time intervals.

  Furthermore, what is indicated by reference numeral 3 is memory means, what is indicated by reference numeral 4 is arithmetic means, and what is indicated by reference numeral 5 is tendency determination means, which are built in a computer connected to the weighing scale 2. ing.

  Thus, in the present embodiment, the weight of the fluid F that fluctuates in the tank 1 is continuously measured and managed by the weigh scale 2, and the procedure is based on the flowchart of FIG.

First, an actually measured weight value W (W ₁ · W ₂ (W ₁ is the latest)) obtained by measuring the weight of the fluid F in the tank 1 at predetermined time intervals by the weigh scale 2 is transmitted to the computer as a data signal ( Step [1]). In this embodiment, measurement is performed at intervals of 0.05 seconds. This actually measured weight value W generally has a gradual decreasing trend because the paint (fluid F) is consumed. In the raw data, not only the paint is reduced, but also the ink level is returned from the overflow of the ink tray by the inflow device 11, so that the liquid level may fluctuate and repeatedly increase and decrease at each time (see FIG. 3).

Next, N actually measured weight values W (W ₁ · W ₂ ... W _N ) are accumulated to constitute the actually measured weight value group WA (step [3a]). Each time the latest measured weight value W ₁ is added, the measured weight value group WA holds N numerical values by erasing W _{N + 1} and sequentially updates and records them in the memory means 3 ( Step [2a]). At this time, the measurement work by the weighing scale 2 is always performed irrespective of the presence or absence of recording in the memory means 3.

  In the present embodiment, the measurement accuracy can be improved by setting the number N of actually measured weight values W accumulated in the actually measured weight value group WA to 1000 or more.

Each time the actual weight value group WA is updated, the arithmetic means 4 performs averaging by the moving average process based on the actual weight value group WA (step [4a]), and the average weight value A (A _1. A ₂ (A ₁ is the latest)) is calculated one after another (step [5a]).

  Here, the moving average process of the present invention will be described. FIG. 4 is a graph showing the measured value of the weigh scale 2 when the liquid raw material (fluid F) is consumed at a pace of 0.5 kg / min in the coating apparatus and the value obtained by moving average of the measured value. is there. When the measured value of the weighing scale 2 according to this graph is subjected to moving average processing, an average weight value A is obtained.

That is, an interval (number N) of a certain period for taking an average value is determined, an average value is calculated for continuous data within the interval, and the average value is set as a value a at the final point of the continuous data. Next, (erased W _{N + 1} by adding the latest measured weight values W ₁₎ for that shifting the measurement data only one time, also an average value for the continuous data of the same interval of (N) one it The next value a at the final time point of the continuous data shifted by the time point is assumed. This procedure is repeated sequentially to calculate the average weight value A. The data display is delayed by time B from the actual measurement value.

  At this time, the slope of the measured value of the weight scale 2 and the value obtained by moving average of the measured values are substantially the same, and both indicate the rate of change of the value of the measured value of the weight scale 2. Although it is difficult to calculate the change rate of the measured value in a short time with the measured value (raw data) of the weighing scale 2, the change rate of the measured value can be calculated in a short time by calculating the moving average value of the measured value. I can grasp it.

  Note that if this average weight value A is calculated without using the measuring method of the present invention, it is calculated based on the accumulated data including the points where the measured weight value increases rapidly, so that the curve shown in FIG. It will be affected by sudden changes such as when the liquid is replenished, resulting in large errors and poor response.

  As the moving average processing employed in this embodiment, in addition to simple moving average, weighted moving average, exponential moving average, triangular moving average, sine weighted moving average, cumulative moving average, and other processing methods are used depending on the accuracy and situation. Or it can be employed in combination.

On the other hand, K pieces (<N) of actually measured weight values W (W ₁ · W ₂ ... W _K ) are accumulated to constitute a tendency determining actually measured weight value group WJ (step [3b]). In the present embodiment, the number K of actual weight values W accumulated in the trend determination actual weight value group WJ is set to be equal to or less than 1/20 of the number N of actual weight values W accumulated in the actual weight value group WA. More specifically, N = 1000, K = 50, the measurement interval by the weight scale 2 is 0.05 seconds, N is 50 seconds, and K is 2.5 seconds. The measured weight value W accumulated in the trend determination measured weight value group WJ may be used in combination with the memory means 3, but can be recorded in a calculation memory as a separate system (step [2b]). .

This tendency determining measured weight value group WJ, each time adding a latest measured weight values W _1, successively updated holds the K numbers by deleting W K _{+ 1.}

Then, each time the trend determination actual weight value group WJ is updated, the arithmetic means 4 averages it by moving average processing based on the trend determination actual weight value group WJ (step [4b]). The determination short-term average value J (J ₁ · J ₂ ... (J ₁ is the latest)) is calculated one after another (step [5b]) (see FIG. 6). The moving average processing method is the same as that for obtaining the average weight value A.

Then, (in this embodiment, 0.5 seconds before) the latest calculated value J ₁ and the unit time T before this trend determination short term average value J compared by tendency determination unit 5 the magnitude of the value J _T calculated for The value difference (J ₁ −J _T ) is calculated as an increase / decrease determination value P (step [6b]).

When the increase / decrease determination value P is negative, it is determined that the weight of the fluid F in the tank 1 is decreasing (step [7b]), and it is determined whether there has been a recording stop period in the past. in (step [7a]), if the recording stop time was not, add the latest measured weight values W ₁ to the measured weight value group WA, continue to be recorded onto the memory means 3, the calculating means 4 is used to calculate the average weight value A.

  In this embodiment, the calculated average weight value A can be displayed on the display means 6 such as a computer monitor screen.

Further, when the increase / decrease determination value P becomes positive (step [7b]), it is determined that the weight of the fluid F in the tank 1 has changed from a decreasing tendency to an increasing tendency, and the latest measured weight value W _1. Recording in the memory means 3 is stopped (step [8b]). Note that the measurement of the actual weight value W by the weigh scale 2 is always continued.

Then, the turned value of decrease determination value P is negative, when turned to decrease from the increase trend, starts the adding the latest measured weight values W ₁ to the measured weight value group WA again, Recording in the memory means 3 is resumed (step [8a]).

Then, as shown in FIG. 7, retrospectively measured weight value group of N content of measured weight value group back to front from recorded immediately before stopping measured weight value W _E immediately before the recording stop period to the memory means 3 It reads out from the memory means 3 as WR (step [9]).

Then, the immediately after recording resumption immediately after resumption measured weight value W _S by calculating the difference value V between the stop just before the measured weight value W _E, retrospectively measured weight value of the difference value V is read from the memory means 3 Each is added to each numerical value of N in the group WR (step [10]) to constitute a virtual retrospectively measured weight value group WR ′ (step [11]).

Furthermore, as value of said resume immediately measured weight value W _S and immediately before stop measured weight value W _E match (step [12]), the virtual retrospectively measured weight in a blank portion of the stopped period of the memory recording The value group WR ′ is retrospectively supplemented (see FIG. 8). In this way, N numerical values in the weight value group as the basis of calculation are held, and the actual measurement weight value group WA is resumed (step [13]), and the average weight value A is calculated (step [14]).

  By doing so, in order to intentionally provide a blank period of measurement and cut without including data when there is a sudden weight change, and to supplement this blank period using the past trend history, High-precision measurement can be continuously performed without being affected by disturbance factors.

  Therefore, according to the measuring method according to the present embodiment, it is possible to continuously measure a fluid such as paint contained in a tank such as a paint container in the coating apparatus, and discharge and replenishment are simultaneously performed. Even if the weight changes every moment, there is little error and it can be measured accurately.

  The present invention is generally configured as described above, but is not limited to the illustrated embodiment, and various modifications are possible within the description of “Claims”. The apparatus to be used is not limited to the coating apparatus and can be applied to other apparatuses, and the number of N and K can be appropriately changed according to the accuracy.

  Furthermore, the fluid F to be measured is not limited to a liquid as long as it has fluidity, and powders, fluids, and the like can be employed, and any of these belongs to the technical scope of the present invention.

1 tank
11 Inflow device
12 Supply device 2 Weigh scale 3 Memory means 4 Calculation means 5 Trend determination means 6 Display means F Fluid S Sheet material

Claims (6)

In a tank 1 in which fluid F having fluidity such as liquid or granular material is accommodated and discharged quantitatively per unit time, the weight of the fluid F that fluctuates in the tank 1 is continuously measured by a weigh scale 2. A method for measuring and managing
An actual weight value W (W ₁ · W ₂ (W ₁ is the latest)) obtained by measuring the weight of the fluid F in the tank 1 at predetermined time intervals by the weighing scale 2 is transmitted as a data signal,
N actual weight values W (W ₁ · W ₂ ... W _N ) are accumulated to form an actual weight value group WA. The actual weight value group WA is added each time the latest actual weight value W ₁ is added. , W _{N + 1} is erased, N numbers are held and sequentially updated and recorded in the memory means 3,
Each time the actual weight value group WA is updated, the arithmetic means 4 averages the average weight value A (A ₁ · A ₂ ... (A ₁ is the latest) by the moving average process based on the actual weight value group WA. )) One after another,
K pieces (<N) of actual weight values W (W ₁ · W ₂ ... W _K ) are accumulated to constitute a trend determination actual weight value group WJ. Each time the measured weight value W1 is added, K numbers are retained by erasing W _{K + 1} and sequentially updated.
Each time the trend determination actual weight value group WJ is updated, the arithmetic means 4 performs averaging by the moving average process based on the trend determination actual weight value group WJ, and the trend determination short-term average value J (J ₁ · J ₂ (J ₁ is the latest))
The magnitude of the latest calculated value J ₁ and the unit time T value J _T calculated before this trend determination short term average value J by comparison operation tendency determination unit 5, these values difference (J ₁ -J _T ) As an increase / decrease determination value P, when the increase / decrease determination value P is negative, it is determined that the weight of the fluid F in the tank 1 is decreasing, and the latest measured weight value W ₁ is determined as the actually measured weight value. In addition to the group WA, recording in the memory means 3 is continued, and the calculation means 4 calculates the average weight value A,
When the increase / decrease determination value P becomes positive, it is determined that the weight of the fluid F in the tank 1 has changed from a decreasing tendency to an increasing tendency, and the latest measured weight value W1 is recorded in the memory means 3. Stop,
Then, the turned value of decrease determination value P is negative, when turned to decrease from the increase trend, starts the adding the latest measured weight values W ₁ to the measured weight value group WA again, Resuming recording to the memory means 3,
While reading from the memory means 3 of N content of measured weight value group back to front from recorded immediately before stopping measured weight value W _E immediately before the recording stop period to the memory unit 3 as a retrospective measured weight value group WR ,
Wherein immediately after recording resumption immediately after resumption measured weight value W _S by calculating the difference value V between the stop just before the measured weight value W _E, retrospectively measured weight value group WR to the difference value V is read from the memory means 3 A virtual retroactively measured weight value group WR ′ is formed by adding to each of the N numerical values in
As value of said resume immediately measured weight value W _S and immediately before stop measured weight value W _E match, the virtual retrospective measured weight value group WR 'in blank places in the recording stop period to the memory means 3 In the tank, the N weight values in the weight value group that is a basis for calculation are retained retroactively, and the actual weight value group WA is resumed to calculate the average weight value A. Measuring method of fluid weight.   2. The method for measuring fluid weight in a tank according to claim 1, wherein the number N of actual weight values W accumulated in the actual weight value group WA is 1000 or more.   The number K of actual weight values W accumulated in the actual weight value group WJ for tendency determination is set to be equal to or less than 1/20 of the number N of actual weight values W accumulated in the actual weight value group WA. A method for measuring a fluid weight in a tank according to 1 or 2.   The method for measuring a fluid weight in a tank according to any one of claims 1 to 3, wherein a circulation structure is formed by providing an inflow device 11 for the fluid F in the tank 1.   The method for measuring the weight of fluid in a tank according to any one of claims 1 to 4, wherein the numerical value of the average weight value A is displayed by the display means 6.   The method for measuring the weight of a fluid in a tank according to any one of claims 1 to 5, wherein the fluid F to be measured is a liquid.

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