JP2013124125A - Liquid filling method and liquid filling apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid filling method and liquid filling apparatus capable of filling a filling liquid up to a target weight neither too much nor too little, reducing a variation in the filling amount of a filled product, rapidly coping with disturbance changes in the physical property, filling environment or the like of the filling liquid.SOLUTION: Before starting regular work of filling the liquid of the target weight into a container, an actual head amount by which it flows out from that filling valve after starting an operation of closing the filling valve is measured at flow rates of a plurality of patterns of the liquid to prepare a head characteristic curve interpolated by connecting together a plurality of control points indicating a corresponding relationship between the flow rate of each pattern and the actual head amount, or approximated to the plurality of control points, during the regular work, the flow rate when filling is measured in real time by a gravimeter, an estimated head amount by which it flows out after starting the filling valve closing operation according to the flow rate of the filling liquid which is being filled is always obtained based on the head characteristic curve, and the filling valve is operated to close at a timing that the filling amount of the liquid reaches a predetermined weight that the estimated head amount is subtracted from the target weight.

Description

  The present invention relates to a liquid filling method and a liquid filling apparatus for filling a container with a fixed amount of liquid using a weighing scale.

  When the filling liquid is quantitatively filled in the container, the weighing cell such as a load cell for measuring the weight of the container placed on the weighing table and the filling liquid supplied from the filling liquid tank are placed in the container on the weighing table. Using a liquid filling apparatus having a filling nozzle for injecting and a filling valve for opening and closing a passage of the filling liquid supplied to the filling nozzle, the filling valve is opened and filling is started. When the weight of the container (exactly the net weight obtained by subtracting the weight of the container itself from the total weight of the liquid-filled container. Hereinafter, this net weight is referred to as “filled weight”) becomes a predetermined weight. A liquid filling method for closing a filling valve and finishing filling has been executed.

  In such a liquid filling method, even after the filling valve is closed, the liquid on the downstream side of the filling valve falls into the container through the filling nozzle (hereinafter, the dropped amount after the filling valve is closed). When the filling valve is closed by detecting that the filling weight of the filling liquid in the container has reached the target weight by a weight meter, the filling liquid is injected into the filling weight by the amount of the head. End up. Therefore, generally, the weight obtained by subtracting the drop amount from the target weight of the liquid filled in the container is obtained as the predetermined weight, and when the predetermined weight is reached, the filling valve is closed and the subsequent drop amount is added. The final filling weight is set as the target weight.

  However, the flow rate of the filling liquid (weight change amount per unit time) is, for example, increase / decrease in the number of containers that are branched from the same filling liquid tank and filled at the same time, changes in physical properties of the liquid, It changes every moment due to changes in the pressure of the filling liquid.

  For example, in a rotary type or in-line type filling device, when filling a container by opening a plurality of filling valves at the same time, the container is not transported or is filled at the same time just before the operation of the device is stopped. When the prescribed number to be performed is insufficient, the number of filling valves that are simultaneously opened and filled is reduced, so that the flow rate of the filling liquid in the entire filling device is reduced. In proportion to this decrease in the flow rate, the pressure in the tank temporarily increases due to the reaction delay of the filling tank pressure regulator, so that the discharge pressure from each filling nozzle that continues to fill by opening the filling valve And the flow rate of these individual filling nozzles will temporarily increase.

  On the contrary, immediately after the start of the operation of the filling device, the containers are sequentially conveyed and the number of filling valves that are simultaneously opened and filled increases, so that the flow rate of the filling liquid in the entire filling device increases. In proportion to this increase in flow rate, the pressure in the filling tank temporarily decreases, the discharge pressure from the individual filling nozzles that continue filling by opening the filling valve is reduced, and these individual fillings are reduced. The flow rate of the nozzle will temporarily decrease.

  Further, the flow rate of the filling liquid also changes when the quality of the filling liquid changes due to factors such as environmental temperature (for example, the viscosity becomes high).

  And since the response speed which closes the said filling valve cannot be adjusted at any time according to the operating environment, if the flow volume of a filling liquid changes, naturally a head amount will also change.

  Therefore, conventionally, as the control for changing (correcting) the drop amount according to the flow rate of the filling liquid, as shown in Patent Document 1, the flow rate of the filling liquid is calculated from the increased weight within a fixed time during filling. The flow rate detecting means for storing, the storage means storing the closing timing of the filling valve corresponding to the flow rate of the filling liquid, and the filling valve closing timing corresponding to the flow rate of the filling liquid detected by the flow rate detecting means are read by the storage means. And a valve opening / closing command means for controlling opening / closing of the filling valve, and there is a head amount correction method for determining the filling valve closing timing from the flow rate of the filling liquid and preventing the occurrence of filling failure.

In this head amount correction method, the flow rate X is obtained from the increased weight within a certain time during filling, and the predicted head amount Y in the current filling is calculated from the previous head amount A and the previous flow rate B and the current flow rate X. The filling valve is closed when the weight is calculated by the equation and the weight is obtained by subtracting the predicted drop amount Y from the target filling weight. The calculation formula is as follows, and K is a flow rate proportional coefficient.
Y = K * A * X / B + (1-K) * A

JP 09-169394 A

  However, as a result of various studies on the relationship between the flow rate of the filling liquid and the head amount, the inventors have found that the “head amount” in the gravimetric filling device is the flow rate at the time of filling (unit: (Liquid volume per hour) Even if a calculation formula that assumes a direct proportion change even in part is used, and the estimated drop amount is calculated by applying the flow rate at the most recent filling, the filling error with respect to the target weight It has been found that there are many cases where it cannot be made small and an appropriate amount cannot be filled.

  The reason why the flow rate and the drop amount are not necessarily in direct proportion in the filling device using a weight meter is that, for example, the magnitude at which the discharge pressure of the filling liquid into the container acts on the weight meter is the discharge port of the filling nozzle Since the distance varies depending on the distance between the liquid level and the liquid level, there may be a large difference in the accuracy of weight measurement with a weigh scale. For example, when filling with the filling nozzle fixed to the upper part of the container mouth so that the filling liquid falls into the container from a high position, while inserting the filling nozzle into the container and keeping a certain distance from the filled liquid surface There is a large difference in the accuracy of measurement with the weigh scale from the case of raising the filling nozzle.

  Therefore, the present invention always fills the filling liquid with the target weight without excess or deficiency, and also can reduce the variation in the filling amount of the filled product, thereby changing disturbances such as the physical properties of the filling liquid and the filling environment. It is an object of the present invention to provide a liquid filling method and a liquid filling apparatus that can respond quickly.

  The first feature of the liquid filling method of the present invention is that the liquid is filled from the filling liquid tank to the filling nozzle while measuring the filling amount of the liquid filled in the container from the filling liquid tank via the filling nozzle. A liquid filling method in which a filling valve for opening and closing a liquid passage to be led is closed at a predetermined timing to fill the container with a target weight of liquid, and before starting the main operation of filling the container with the target weight of liquid, A plurality of controls that measure the actual drop amount that flows out from the filling valve after the filling valve starts the closing operation at a plurality of patterns of liquid flow in advance and indicate the correspondence between the flow rate of each pattern and the actual drop amount A drop characteristic curve interpolated between points, or a drop characteristic curve approximated to the plurality of control points, is created and managed, and during this work, whether the weight increases within a certain time during filling. The flow rate is obtained, and based on the head characteristic curve, the predicted head amount that flows out after the start of the closing operation of the filling valve according to the flow rate of the filling liquid during filling is obtained. The filling valve is closed at a timing when a predetermined weight is obtained by subtracting the predicted drop amount.

  According to such a liquid filling method, the most appropriate predicted drop amount can be obtained according to the flow rate at the time of filling, which changes in real time, using the drop characteristic curve created before the start of the main work of filling the target weight of liquid. Therefore, it becomes possible to fill the filling liquid with high accuracy without exceeding the target weight.

  The second feature of the liquid filling method of the present invention is that when the filling of the container into the container in the present work is completed, the flow rate and the actual drop amount immediately before the completion of filling the container with the liquid are measured, and the measured actual drop is measured. The amount is fed back and control is performed to update the managed head characteristic curve.

  According to such a liquid filling method, every time the filling of the filling liquid into the container is completed, the actual drop amount is fed back to the drop amount characteristic curve, and the drop amount correction is performed to update the drop characteristic curve. Fills the weight without excess and deficiency, and can quickly respond to disturbance changes such as physical properties of the filling liquid and filling environment.

  The first feature of the liquid filling apparatus of the present invention is that a weighing machine for measuring the weight of the filling liquid filled in the container, and a container in which the liquid fed from the filling liquid tank is set in the weighing scale. Interpolated by connecting between a filling nozzle for filling in, a filling valve for opening and closing a liquid passage for guiding the filling nozzle liquid from the filling liquid tank, and a plurality of control points corresponding to the flow rate and the actual drop amount. A drop characteristic curve consisting of a curve or a curve approximated to the plurality of control points is created and managed, and a drop for obtaining a predicted drop amount corresponding to the flow rate of the filling liquid during filling is created based on the drop characteristic curve. The amount determination means, the flow rate conversion means for calculating the flow rate from the increased weight within a fixed time during filling, and the filling by the fact that the weighing instrument has measured a predetermined weight obtained by subtracting the expected drop amount from the target weight. A valve opening and closing control means for closing controlling lube, in that with a certain.

  According to the liquid filling apparatus configured in this way, before the start of the main operation of filling the container with the target weight of liquid, the filling valve of the filling valve is set in advance at a flow rate of a plurality of patterns (preferably four patterns or more) of the liquid. A head characteristic curve obtained by measuring the actual head amount flowing out from the filling valve after the start of the closing operation and interpolating between a plurality of control points indicating the correspondence between the flow rate of each pattern and the actual head amount in the head amount determining means. Alternatively, a head characteristic curve approximated to the plurality of control points is created and managed, and during this work, the flow rate conversion means detects the flow rate in real time from the increased weight within a certain time during filling. The head amount determining means obtains the predicted head amount flowing out after the start of the closing operation of the filling valve in accordance with the flow rate of the filling liquid during filling at all times based on the head characteristic curve. In the opening / closing control means, the filling valve is closed at a timing when the filling amount of the liquid into the container becomes a predetermined weight obtained by subtracting the predicted drop amount from the target weight, thereby the liquid having the first feature described above. By performing the filling method, the filling liquid can be filled to the target weight without excess or deficiency.

  The second feature of the liquid filling apparatus according to the present invention is that the drop amount determining means calculates the difference between the flow rate immediately before completion of filling of the liquid into the container and the actual drop amount measured when the filling of the liquid into each container is completed. The point is that control is performed by reflecting a plurality of control points indicating the correspondence relationship on the head characteristic curve managed and updating the head characteristic curve.

  According to the liquid filling apparatus configured as described above, the liquid filling method having the second feature described above is executed, the filling liquid is filled with the target weight without excess or deficiency, and disturbances such as physical properties of the filling liquid and filling environment are caused. Respond quickly to changes.

  As described above, according to the liquid filling method and the liquid filling apparatus of the present invention, the filling liquid can be filled to the target weight without excess or deficiency, and the variation in the filling amount of the filled product can be reduced. There is an excellent effect that it is possible to respond quickly to disturbance changes such as the physical properties of the liquid and the filling environment.

The block diagram which shows the structure in embodiment of the liquid filling apparatus of this invention. Flowchart for explaining control of quantitative filling in the first embodiment of the liquid filling method of the present invention. The flowchart explaining the control for creating the head characteristic curve in the first embodiment of the liquid filling method of the present invention. An example of a drop characteristic curve created in the liquid filling method of the present embodiment An example of table data created by obtaining a head amount corresponding to a flow rate of 1 g / s based on the head characteristic curve of FIG. Flowchart for explaining control of quantitative filling in the second embodiment of the liquid filling method of the present embodiment Graph for explaining an example of drop characteristic curve update control An example of table data created by obtaining a head amount corresponding to a flow rate of 1 g / s based on each head characteristic curve of FIG. The graph for demonstrating another Example (comparative example) of head characteristic curve update control An example of table data created by obtaining a head amount corresponding to a flow rate of 1 g / s based on each head characteristic curve of FIG.

  The liquid filling apparatus of the present embodiment described below includes a filling liquid tank for storing filling liquid (filling liquid) such as soy sauce, edible oil, and shampoo, and a filling mechanism arranged in a plurality of series in this filling liquid tank. A rotary type or series type liquid filling device is assumed. Since the filling mechanism is configured similarly, only one series of filling mechanisms and a liquid filling method using the filling mechanism will be described, and other filling mechanisms and a liquid filling method using the filling mechanism will be described. Is omitted.

  The present invention is not limited to the rotary or in-line type liquid filling apparatus as described above, and may be a liquid filling apparatus having only a single filling mechanism. Similarly, only a single filling mechanism is available. It may be a liquid filling method using.

<Liquid filling device>
As shown in FIG. 1, the liquid filling apparatus (filling mechanism) of the present embodiment has a load cell 1 as a weigh scale for measuring the weight of a filling liquid filled in a container (not shown), and a desired internal pressure. A filling nozzle 3 that fills a container (not shown) set in the load cell 1 with a filling liquid fed from a filling liquid tank 2 that is controlled so as to be held at a constant level; A filling valve 4 having a known configuration for opening and closing the liquid passage 2a for introducing the filling liquid, and a load cell for controlling the filling valve 4 to be closed at a predetermined timing and a predetermined speed so that the container is filled with a target weight of the filling liquid. And a control unit 5. The filling nozzle 3 and the filling valve 4 may be integrally formed.

  Here, the load cell 1 is connected to a central control device 6 through a communication means such as CC-Link via a flow rate conversion means 5a that constitutes a load cell control unit 5 including an indicator so that signals can be transmitted. When the load cell 1 detects a change in weight, the flow rate conversion means 5a converts the weight (w) into a flow rate. That is, the flow rate conversion means 5a detects the flow rate (for example, in units of 0.1 g / s) from the increased weight within a fixed time during filling, and the weight and flow rate of the filling liquid at that time are detected by the flow rate management unit of the central controller 6. 8 is converted into a digital signal and transmitted.

  The filling valve 4 is connected to valve opening / closing control means 5b constituting the load cell control unit 5, and can be opened and closed by the valve opening / closing control means 5b. The valve opening / closing control means 5b is a container according to the target weight of the filling liquid input from the input unit 9 or the like of the central controller 6 and the predicted head amount acquired from the head amount determining means 7 of the central controller 6 described later. As will be described later, the filling valve 4 is controlled to be closed when the liquid filling amount becomes a predetermined weight obtained by subtracting the predicted drop amount from the target weight.

  The central controller 6 includes a flow rate management unit 8 for storing the flow rate transmitted from the flow rate conversion means 5a, a curve obtained by interpolating between a plurality of control points (points) indicating the correspondence between the flow rate and the actual drop amount, Alternatively, a drop characteristic curve indicating a correspondence relationship between the flow rate and the actual drop amount, which is a curve approximated to the plurality of control points, is managed, and based on the drop characteristic curve, the flow rate of the filling liquid during filling is handled. A head amount determining unit 7 for obtaining a predicted head amount, an input unit 9 such as a touch panel and a key, a display unit 10 such as a liquid crystal panel, and a storage unit 11 for storing various other data are provided.

  In the present embodiment, the head amount determining means 7 of the central controller 6 further includes a curve obtained by interpolating between a plurality of control points indicating the correspondence between the flow rate and the actual head amount, or the plurality of control points. The head characteristic curve can be created by approximating the points. A method for creating a head characteristic curve based on a plurality of control points uses a known method, and a tool for automatically creating the head characteristic curve can also be executed in the central controller 6 by a computer program that has been made public. .

  Further, the filling liquid tank 2 can be adjusted in internal pressure by the pressure adjusting means 13, and the pressure adjusting means 13 is configured to be controlled by the pressure control means 14 of the central controller 6.

Next, two embodiments of the liquid filling method of the present invention will be specifically described.
In the liquid filling method of the present invention, using the liquid filling apparatus configured as described above, the load amount of the liquid filled in the container from the filling liquid tank 2 through the filling nozzle 3 is measured by the load cell 1, The filling valve 4 that opens and closes the liquid passage 2a between the filling liquid tank 2 and the filling nozzle 3 is closed at a predetermined speed at a predetermined timing to fill the container with a target weight of liquid.

  In the following description, the actual amount of liquid flowing out from the filling nozzle 3 after starting the closing operation of the filling valve 4 at a certain flow rate is defined as “actual drop amount”, and filling is performed after the closing operation of the filling valve 4 at a certain flow rate is started. The amount of liquid predicted to flow out from the nozzle 3 is defined as the “predicted drop amount”. Further, when the actual head amount is measured in order to create a head characteristic curve described later, the amount of liquid flowing out from the filling nozzle 3 after the start of the closing operation of the filling valve 4 for interrupting the supply of the filling liquid is expressed as “temporary head amount”. Is defined.

  In addition, it is assumed that necessary data such as data relating to the target weight of the filling liquid is input to the liquid filling apparatus in advance.

<Liquid filling method 1>
FIG. 2 is a flowchart illustrating a control flow for quantitative filling in the liquid filling method.

  In the liquid filling method of the present embodiment, the filling liquid is filled in advance with a flow rate of n patterns (n is an integer of 4 or more) before starting the main operation of filling a container with a filling liquid of a target weight to obtain a product. The actual head amount is measured, and from this measurement result, a head composed of a curve interpolated by connecting a plurality of control points indicating the correspondence between the flow rate and the actual head amount, or a curve approximated to the plurality of control points. It is necessary to create a characteristic curve.

  Therefore, when the liquid filling apparatus is operated, first, it is confirmed whether or not the drop characteristic curve for filling this time has been created (ST1), and the drop characteristic curve for filling this time is still created and managed. If not (No in ST1), the head characteristic curve is created (ST2). If the drop characteristic curve for filling this time has already been created and managed (Yes in ST1), the step of creating the drop characteristic curve is omitted, and the process proceeds to the next step (ST3).

  FIG. 3 is a flowchart of the control related to the measurement of the head and the creation of the interpolation curve, which is executed in the head amount determination means 7 in order to create the head characteristic curve.

  In this control, the pressure in the filling liquid tank 2 is changed for each measurement in order to set the flow rate of the filling liquid to four patterns. It is desirable to set a plurality of pressures in the filling liquid tank 2 within a range in which a flow rate at the time of actual filling of the filling liquid can be obtained. Therefore, first, the number (n) of patterns to be measured is input as an integer of 4 or more from the input unit 9 of the central controller 6, and the pressure in the filling liquid tank 2 in each pattern is set (ST101). In the present embodiment, it is assumed that the actual drop amount in the flow rate of the filling liquid of four patterns is measured (n = 4), and the pressure in the filling liquid tank 2 is also 0.05 Mpa, 0.06 Mpa, 0.07 Mpa, It is set to 4 levels of approximately equal differential pressure of 0.08 MPa. This setting is appropriately stored in the storage area of the drop amount determining means 7 (including the case of the storage unit 11; the same applies hereinafter).

  Next, the head count n is reset to n = 0 (ST102).

  Subsequently, 1 is added to the current drop count n (ST103).

  Then, the pressure control means 14 controls the pressure adjusting means 13 so that the pressure is set in the pattern (n = 1) managed in the storage area of the head amount determining means 7 to control the inside of the filling liquid tank 2. Is adjusted (ST104).

  Thereafter, the filling valve 4 is opened by the valve opening / closing control means 5b, and the first filling of the filling liquid into the container set in the load cell 1 is started (ST105).

  At the time of filling, the load cell 1 sets the weigh scale to 0 in order to cancel the tare weight when the container is set. By doing so, the positive amount of the filling amount can be detected.

  In this embodiment, in order to create a head characteristic curve, first, when the flow rate conversion means 5a detects that the container is filled with half the target weight (assuming the target weight is 200 g), Once the filling valve 4 is closed, filling is interrupted, and a drop amount (temporary drop amount) at this time is obtained. Then, the filling valve 4 is opened again to resume filling. It should be noted that the amount of the filling liquid supplied first for creating the head characteristic curve is not limited to the half of the target weight described above. The ratio between the amount of filling liquid supplied first and the target weight can be freely set. When the flow rate conversion means 5a detects that the filling liquid of the target weight-temporal drop amount is filled in the container, the filling valve 4 is closed and the first filling is completed (ST106). That is, the filling is completed at the closing timing of the filling valve 4 based on the provisional drop amount.

Then, the actual drop amount under this first filling condition (actual drop amount during drop measurement) is obtained (ST107). The actual drop amount at this time can be obtained by the following equation from the relationship between the final filling liquid amount (actual filling weight), the target weight, and the temporary drop amount.
Actual head drop at head measurement = (actual filling weight-target weight) + temporary head

  Then, the flow rate immediately before closing the filling valve 4 and the actual drop amount at the time of drop measurement are transmitted to the flow rate management unit 8 of the central controller 6 and stored in the storage area of the drop amount determination means 7 via this flow rate management unit 8. (ST108).

  Subsequently, it is confirmed whether or not the head measurement number is the set head measurement number n (four times in the present embodiment, n = 4) (ST109), and the head number measurement number n still set is reached. If not (No in ST109), the process returns to ST103 again, 1 is added to the current drop measurement count n, and the following ST104 to ST108 are repeated.

  When the set number n of heads is reached (Yes in ST109), that is, when n = 4 in the present embodiment, the head amount determining means 7 is displayed on a graph showing the relationship between the head amount and the flow rate. A curve obtained by plotting control points indicating the correspondence between the flow rate and the actual head amount stored in each storage area stored in the storage area and interpolating the control points using a known interpolation method or the like Is created as a drop characteristic curve that can be referred to during filling, or a curve approximated to the control point is created as the drop characteristic curve and stored in the storage area of the drop amount determining means 7 (ST110).

  In FIG. 4, the control point n = 1 (flow rate: 73 g / s, drop amount: 21.5 g) in the first drop measurement with the pressure in the fill liquid tank 2 set to 0.05 Mpa, the fill liquid tank 2 is shown. Control point n = 2 (flow rate: 88 g / s, drop amount: 24.6 g) in the second drop measurement with the inner pressure set to 0.06 Mpa, third time with the pressure in the filling liquid tank 2 set to 0.07 Mpa Control point n = 3 in the head measurement of the current (flow rate: 106 g / s, head amount: 27.7 g), and control point n = 4 in the fourth head measurement in which the pressure in the filling liquid tank 2 is 0.08 Mpa. An example of a drop characteristic curve created by interpolating between (flow rate: 128 g / s, drop amount: 30.7 g) using a known interpolation method or the like is shown. In the drop characteristic curve shown in FIG. 4, a drop characteristic curve assuming a flow rate of 50.0 g / s to 149.0 g / s is created.

  Returning to FIG. 2, in the control for quantitative filling in the liquid filling method, when the load cell control unit 5 confirms that the container is set in the load cell 1 (Yes in ST2), the valve opening / closing control means. The filling valve 4 is opened by 5b, and the filling liquid is supplied from the filling liquid tank 2 into the container through the filling nozzle 4 (ST3).

  Even during this work, the load cell 1 sets the weight scale to 0 in order to cancel the tare weight when the container is set. When filling of the filling liquid is started (ST4), the load cell 1 measures the change in the weight of the container, in other words, the filling amount (weight) of the filling liquid filled in the container in real time (ST5).

  Then, the flow rate conversion management means 5a obtains the flow rate at that time in real time from the weight of the filling liquid, and converts the flow rate of the filling liquid into a digital signal and transmits it to the flow rate management unit 8 of the central controller 6 (ST6).

  Subsequently, in the central controller 6, the head amount determining means 7 obtains a predicted head amount corresponding to the current flow rate of the filling liquid transmitted to the flow rate management unit 8 based on the head characteristic curve (ST7). The valve opening / closing control means 5b always obtains the predicted head amount from the head amount determining means 7 of the central controller 6, and the filling amount of the filling liquid into the container changes from the target weight according to the change in the flow rate. Whether or not the predetermined weight obtained by subtracting the predicted head amount is continuously managed (circulation from ST8 No to ST4), and the filling valve 4 is closed when the filling amount of the filling liquid reaches the predetermined weight. Control is performed as follows (ST9).

  Thereafter, it is determined whether or not this work is to be ended (ST10), and when this work is continued (No in ST10), the process returns to ST3 again, and quantitative filling is performed on the next supplied container.

  Also in the present embodiment, the filling liquid flows out from the start of the closing operation of the filling valve 4 to the fully closed state. However, in the liquid filling method of the present embodiment, this outflow amount is calculated as the predicted drop amount. Therefore, the liquid can be accurately filled into the container without excess or deficiency with respect to the target weight.

  Thus, using the liquid filling apparatus of this embodiment, the flow rate at the time of filling is measured in real time by the load cell 1, and the drop characteristic curve created before the start of this work is used to respond to the flow rate at the time of filling that changes in real time. Thus, the liquid filling method for obtaining the most appropriate predicted drop amount and closing the filling valve 4 in anticipation of the predicted drop amount before the filling amount of the container reaches the target weight can be executed. As a result, even if the flow rate changes for some reason just before the closing operation of the filling valve 3, an expected drop amount corresponding to the change in the flow rate is obtained and reflected in the acquisition of the closing operation timing of the filling valve 4 in real time. Therefore, it becomes possible to fill the filling liquid with the target weight without excess or deficiency.

  The head amount determining means 7 creates and stores table data in which the flow rate is associated with the predicted head amount based on the head characteristic curve, and in the liquid filling method, based on the head characteristic curve. It is also possible to create table data in which the flow rate is associated with the predicted drop amount, and obtain the predicted drop amount according to the flow rate at the time of filling with reference to the table data. FIG. 5 is an example of table data in which a drop amount corresponding to a flow rate of 100 patterns in units of 1.0 g is obtained based on the drop characteristic curve of FIG.

  In this way, the predicted drop amount corresponding to the flow rate at the time of filling is stored as table data, and by referring to this table data, the predicted drop amount corresponding to the filling flow rate is calculated each time based on the drop characteristic curve. Compared with the case where the required control is performed, the process of determining the closing operation timing of the filling valve can be performed rapidly in a very short time, and the liquid filling amount can be controlled more strictly.

<Liquid filling method 2>
FIG. 6 is a flowchart for explaining a flow of control for quantitative filling in the liquid filling method of the present embodiment. The liquid filling method of the present embodiment is the same as the liquid filling method of the previous embodiment shown in FIG. 2, and the flow rate and the actual drop amount immediately before the completion of filling of the liquid into the container at the completion of filling of the liquid in the work in this operation It differs in that control is performed to measure, feed back the measured actual head amount, and update the managed head characteristic curve.

  The steps common to ST1 to ST9 in the above-described embodiment shown in FIG. 2 are shown in FIG. 6 as ST21 to ST29, respectively, and the description thereof is omitted, but in the liquid filling apparatus of this embodiment, the flow rate conversion is performed. The means 5a transmits not only the flow rate but also the weight of the filling liquid at that time in the form of a digital signal to the flow rate management unit 8 of the central controller 6, and in the steps ST25 and ST26, the filling to be filled in the container The filling amount (weight) of the liquid is measured in real time (ST25), the flow rate conversion means 5a obtains the flow rate in real time from the weight of the filling solution in real time, and the weight and flow rate of the filling solution are digitally signaled to the flow rate management unit 8. Assume that the data is transmitted (ST26).

  In the liquid filling method of this embodiment, after the filling valve 4 is closed at a timing when the filling amount of the liquid into the container becomes a predetermined weight obtained by subtracting the predicted drop amount from the target weight (ST29), the drop amount determining means 7 Then, based on the weight transmitted to the flow rate management unit 8, the actual drop amount under the filling condition of the filling liquid into the container is obtained (ST30).

The actual drop amount at this time (normal drop during normal filling) is the final filling liquid amount (actual filling weight) and the weight when the filling valve starts to be closed, that is, the weight obtained by subtracting the predicted falling amount from the target weight. From the relationship, it can be calculated as follows.
Actual drop amount at normal filling = Actual filling weight-(Target weight-Expected drop amount)

  Then, using the point indicating the correspondence between the flow rate immediately before closing the filling valve 4 and the actual drop amount during normal filling as a correction point, the drop characteristic curve is updated by feeding back (reflecting) the drop characteristic curve. The head amount is corrected, and the updated head characteristic curve is stored (ST31).

  Thereafter, it is determined whether or not this work is to be ended (ST32). If this work is continued (No in ST32), the process returns to ST23 again, and the filling liquid is supplied to the container to be supplied next in the processes up to ST31. And the correction control for updating the head characteristic curve (hereinafter referred to as head characteristic curve update control) is performed again.

  Thus, in the liquid filling method 2 of the present embodiment, the drop characteristic curve is obtained by performing the drop characteristic curve update control for feeding back the actual drop amount and updating the drop characteristic curve every time the filling liquid is filled into the container. Since it becomes a value closer to the true value that responds promptly to changes in the disturbance at that time, it is possible to fill the filling liquid with a high accuracy without exceeding the target weight.

<Example 1 of drop characteristic curve update control>
Here, a specific method of the head characteristic curve update control will be described.
FIG. 7 shows the filling control using the head characteristic curve shown in FIG. 21 shows an example of correction assuming a case where the process of setting the actual drop amount at the normal filling at the flow rate of 70.0 g / s shown in 21 to 22.8 g is performed five times in succession. Times through 5 show the drop characteristic curves after the respective correction processes. FIG. 8 is an example of table data in which 100 head amounts corresponding to a flow rate of 1.0 g / s are obtained based on a head characteristic curve corrected after each processing.

  In the drop characteristic curve update control shown in FIG. 7 and FIG. 8, the correction point (flow rate 70.0 g / s, actual drop amount 22. Extracting a plurality of points indicating a drop amount corresponding to a flow rate of 10.0 g / s with a flow rate of 8 g) as a reference, and creating a drop characteristic curve composed of an approximate curve using the plurality of points as control points. Thus, the head characteristic curve managed by the head amount determining means 7 is updated.

  That is, in the first correction, the drop characteristic curve shown in FIG. 4 and the table data shown in FIG. 5 are corrected (updated), and the correction point flow rate of 70.0 g / s is used as a reference in units of 10.0 g / s. Extract points. That is, in this embodiment, a point indicating a drop amount of 15.8 g corresponding to a flow rate of 50.0 g / s, a point indicating a drop amount of 18.4 corresponding to a flow rate of 60.0 g / s, and a flow rate of 70.0 g / s. A point indicating a head amount 20.8 g corresponding to a flow rate, a point indicating a head amount 23.0 g corresponding to a flow rate 80.0 g / s, a point indicating a head amount 25.0 g corresponding to a flow rate 90.0 g / s, a flow rate 100 A point indicating a head amount of 26.8 g corresponding to 0.0 g / s, a point indicating a head amount of 28.4 g corresponding to a flow rate of 110.0 g / s, and a head amount of 29.8 g corresponding to a flow rate of 120.0 g / s are shown. A point indicating a drop amount of 31.0 g corresponding to a point, a flow rate of 130.0 g / s, and a point indicating a flow rate of 32.0 g corresponding to a flow rate of 140.0 g / s are extracted.

  Among the 10 point drop amounts, the 20.8 g drop amount at the correction point of 70.0 g / s is set to 22.8 g of the correction value, and a drop characteristic curve is created using these 10 points as control points (see FIG. 7), the head characteristic curve managed by the head amount determining means 7 is updated by replacing the new head characteristic curve with the head characteristic curve being managed. Based on the drop characteristic curve created by the first correction, the drop amount corresponding to the flow rate of 10.0 g is as shown in the “first” table data of FIG.

  In this way, the head characteristic curve gradually corresponds to the flow rate that does not need to be corrected by performing head amount correction by feeding back the actual head amount every time the container is filled with the filling liquid and updating the head characteristic curve. The head can be corrected to a head characteristic curve that can determine the head amount to be.

  In the second correction, 10 points are extracted in the same manner, with the drop characteristic curve shown in “First time” in FIG. 7 and the table data in “First time” in FIG. 8 being corrected (updated). To do.

  Of the 10 points of drop, the 21.4 g of the drop at a flow rate of 70.0 g / s, which is the correction point, is set to 22.8 g of the correction value, and a drop characteristic curve is created using these 10 points as control points ( 7), the head characteristic curve managed by the head amount determination means 7 is updated.

  The drop amount corresponding to the flow rate of 1.0 g / s based on the drop characteristic curve created by the second correction is as shown in the “second” table data in FIG.

  Similarly, every time when the actual drop amount during normal filling at the flow rate of 70.0 g / s is detected to be 22.8 g, the third to fifth corrections are performed and the drop characteristic curve is updated. (See the drop characteristic curves shown in “third” to “fifth” in FIG. 7 and the table data shown in “third” to “fifth” in FIG. 8, respectively).

  In this embodiment, the drop amount at the correction point of 70.0 g / s is 21.8 g after the second correction, 22.1 g after the third correction, and 22.4 g after the fourth correction. It became 22.5 g after the fifth correction.

  In this way, the head characteristics including an approximate curve having a control point with a plurality of four or more points (the flow rate is preferably equal) including the correction point from the head characteristics curve under management as a reference for correction. By creating a curve and updating the head characteristic curve managed by the head amount determining means 7, it is possible to perform head amount correction that greatly reflects the numerical value of the correction point.

<Embodiment 2 of the drop characteristic curve update control (comparative example)>
In the head characteristic curve update control shown in FIG. 9 and FIG. 10, the correction point (flow rate 70.0 g / s, actual head amount 22.8 g at normal filling) is calculated from the head characteristic curve currently being managed as a reference for correction. 100 points indicating a head amount corresponding to a flow rate of 1.0 g / s based on the flow rate of), and a head characteristic curve composed of an approximate curve using the 100 points as control points is created. The head characteristic curve managed by the head amount determining means 7 is updated.

  In other words, the first correction includes a correction point flow rate of 70.0 g / s in units of 1.0 g / s, with the drop characteristic curve shown in FIG. 4 and the table data shown in FIG. 5 being corrected (updated). Extract 100 points from 50.0 g / s to 149.0 g / s.

  A head characteristic curve is created by correcting the head amount 20.8 g at the correction point of 70.0 g / s to 22.8 g out of the head amount of the 100 points (shown in “first” in FIG. 9). The head characteristic curve managed by the head amount determining means 7 is updated by replacing the head characteristic curve thus created with the head characteristic curve currently being managed as a reference for correction.

  The drop amount corresponding to the flow rate of 1.0 g based on the drop characteristic curve created by the first correction is as shown in the “first” table data in FIG.

  In the second correction, the drop characteristic curve shown in “First time” in FIG. 9 and the table data of “First time” in FIG. Then, a head characteristic curve was created by correcting the head amount 20.8 g at the correction point of 70.0 g / s to 22.8 g (refer to the curve shown in “second time” in FIG. 9), and this head was created. The head characteristic curve managed by the head amount determining means 7 is updated by substituting the head characteristic curve currently being managed as a correction reference with the characteristic curve.

  The head amount corresponding to the flow rate in units of 1.0 g based on the head characteristic curve created by the second correction is as shown in the “second” table data in FIG.

  Similarly, every time the actual drop amount during normal filling at the flow rate of 70.0 g / s is detected to be 22.8 g, the third to fifth corrections are performed, and the drop characteristic curve is updated ( (See the drop characteristic curves shown in “third” to “fifth” in FIG. 9 and the table data shown in “third” to “fifth” in FIG. 10, respectively).

  In the drop characteristic curve update control of the second embodiment, the drop amount at the correction point of 70.0 g / s is 20.9 g after the second correction, 20.9 g after the third correction, It was 21.0 g by the fourth correction, and 21.0 g by the fifth correction.

  Thus, in the drop characteristic curve update control, the correction point that actually needs to be reflected is only one control point among the 100 control points for creating the drop characteristic curve. Is difficult to be reflected in the head characteristic curve, and it is necessary to repeat many fillings until the head characteristics are updated to the correct head characteristic curve.

  Therefore, in the drop characteristic curve update control of the liquid filling according to the present invention, the drop characteristic curve is corrected by using, as control points, a plurality of four or more points including correction points from the managed drop characteristic curve serving as a correction reference. I found it desirable.

<Other embodiments>
The liquid filling device (filling mechanism) interpolates between the control points indicating the corresponding relationship between the required time per unit weight increase of the filling liquid immediately before closing the filling valve 4 and the actual drop amount in the drop amount determining means 7. A drop characteristic curve consisting of a curve or an approximate curve approximated to the plurality of control points is created and managed, and a predicted drop amount corresponding to the flow rate of the filling liquid is obtained based on the drop characteristic curve, and the valve opening / closing In the control means 5b, a predicted drop amount corresponding to the required time per unit weight increase of the filling liquid detected by the flow rate conversion means 5a is obtained from the drop amount determination means 7, and the predicted drop amount is subtracted from the target weight. The filling valve 4 may be controlled to be triggered by the load cell 1 measuring the predetermined weight.

  In short, the drop characteristic curve is created with the reciprocal of the flow rate, but the amount of filling can be managed more finely than when the predicted head amount is managed by the flow rate. The target weight can be filled with high accuracy without excess or deficiency, and variations in the filling amount of the filled product can be reduced.

  Even in this case, every time the container is filled with the filling liquid, the actual head amount can be fed back to the head characteristic curve, and head amount correction can be performed to update the head characteristic curve. By performing the head amount correction in this way, the filling liquid can be filled to the target weight without excess and deficiency, and it is possible to quickly respond to disturbance changes such as the physical properties of the filling liquid and the filling environment.

  Furthermore, the head amount determining means 7 creates and stores table data in which the required time per unit weight increase of the filling liquid and the predicted head amount are associated based on the head characteristic curve, and stores the table data. The table data in which the required time per unit weight increase of the liquid and the predicted head amount are associated with each other based on the head characteristic curve, and the predicted head amount corresponding to the required time per unit weight increase during filling is calculated. You may make it obtain | require with reference to the said table data.

  Even in this case, the process of determining the closing operation timing of the filling valve can be performed in a very short time compared to the case where the control for obtaining the predicted head amount corresponding to the filling flow rate is performed on the basis of the head characteristic curve. This makes it possible to control the liquid filling amount more strictly.

  Furthermore, in the above-described first example of the drop characteristic curve update control, when determining the control point for creating the drop characteristic curve, the correction point of this time is determined from the currently managed drop correction curve serving as a reference for correction. Although a plurality of points indicating a head amount corresponding to a flow rate of 10.0 g / s with respect to the flow rate of 10 are extracted, the method for determining the control point is not limited to this method. For example, a point indicating a drop amount corresponding to the flow rate of the correction point may be added to a plurality of predetermined points, and these points may be used as control points. Specifically, 50.0 g / s, 60.0 g / s, 70.0 g / s, 80.0 g / s, 90.0 g / s, 100.0 g / s, 110.0 g / s, 120 in advance. A point indicating a drop amount corresponding to a flow rate of 0.0 g / s and 130.0 g / s is used as the control point, and a point indicating a drop amount corresponding to the correction point (for example, a flow rate of 67. g) is used. If 0 g / s is a correction point, a new drop characteristic curve may be created using a control point to which a drop amount corresponding to this flow rate is also added. According to the drop characteristic curve update control, the correction point at this time can be largely reflected in the new drop characteristic curve (the “weight” of the correction point is increased), so that the correction effect can be obtained more quickly. .

  In addition, this invention is not restrict | limited at all to the above-mentioned embodiment, It is included by this invention unless it is contrary to the summary of this invention.

1 Load cell (Weigh scale)
2 Filling liquid tank 3 Filling nozzle 4 Filling valve 5 Load cell control unit 5a Flow rate conversion means 5b Valve opening / closing control means 6 Central controller 7 Head amount determination means 8 Flow rate management part 9 Input part 10 Display part 11 Storage part 13 Pressure adjustment means 14 Pressure control means

  The present invention relates to a liquid filling method and a liquid filling apparatus for filling a container with a fixed amount of liquid using a weighing scale.

  When the filling liquid is quantitatively filled in the container, the weighing cell such as a load cell for measuring the weight of the container placed on the weighing table and the filling liquid supplied from the filling liquid tank are placed in the container on the weighing table. Using a liquid filling apparatus having a filling nozzle for injecting and a filling valve for opening and closing a passage of the filling liquid supplied to the filling nozzle, the filling valve is opened and filling is started. When the weight of the container (exactly the net weight obtained by subtracting the weight of the container itself from the total weight of the liquid-filled container. Hereinafter, this net weight is referred to as “filled weight”) becomes a predetermined weight. A liquid filling method for closing a filling valve and finishing filling has been executed.

  In such a liquid filling method, even after the filling valve is closed, the liquid on the downstream side of the filling valve falls into the container through the filling nozzle (hereinafter, the dropped amount after the filling valve is closed). When the filling valve is closed by detecting that the filling weight of the filling liquid in the container has reached the target weight by a weight meter, the filling liquid is injected into the filling weight by the amount of the head. End up. Therefore, generally, the weight obtained by subtracting the drop amount from the target weight of the liquid filled in the container is obtained as the predetermined weight, and when the predetermined weight is reached, the filling valve is closed and the subsequent drop amount is added. The final filling weight is set as the target weight.

  However, the flow rate of the filling liquid (weight change amount per unit time) is, for example, increase / decrease in the number of containers that are branched from the same filling liquid tank and filled at the same time, changes in physical properties of the liquid, It changes every moment due to changes in the pressure of the filling liquid.

  For example, in a rotary type or in-line type filling device, when filling a container by opening a plurality of filling valves at the same time, the container is not transported or is filled at the same time just before the operation of the device is stopped. When the prescribed number to be performed is insufficient, the number of filling valves that are simultaneously opened and filled is reduced, so that the flow rate of the filling liquid in the entire filling device is reduced. In proportion to this decrease in the flow rate, the pressure in the tank temporarily increases due to the reaction delay of the filling tank pressure regulator, so that the discharge pressure from each filling nozzle that continues to fill by opening the filling valve And the flow rate of these individual filling nozzles will temporarily increase.

  On the contrary, immediately after the start of the operation of the filling device, the containers are sequentially conveyed and the number of filling valves that are simultaneously opened and filled increases, so that the flow rate of the filling liquid in the entire filling device increases. In proportion to this increase in flow rate, the pressure in the filling tank temporarily decreases, the discharge pressure from the individual filling nozzles that continue filling by opening the filling valve is reduced, and these individual fillings are reduced. The flow rate of the nozzle will temporarily decrease.

  Further, the flow rate of the filling liquid also changes when the quality of the filling liquid changes due to factors such as environmental temperature (for example, the viscosity becomes high).

  And since the response speed which closes the said filling valve cannot be adjusted at any time according to the operating environment, if the flow volume of a filling liquid changes, naturally a head amount will also change.

  Therefore, conventionally, as the control for changing (correcting) the drop amount according to the flow rate of the filling liquid, as shown in Patent Document 1, the flow rate of the filling liquid is calculated from the increased weight within a fixed time during filling. The flow rate detecting means for storing, the storage means storing the closing timing of the filling valve corresponding to the flow rate of the filling liquid, and the filling valve closing timing corresponding to the flow rate of the filling liquid detected by the flow rate detecting means are read by the storage means. And a valve opening / closing command means for controlling opening / closing of the filling valve, and determining a closing amount of the filling valve from the flow rate of the filling liquid to prevent a defective filling from occurring.

In this head amount correction method, the flow rate X is obtained from the increased weight within a certain time during filling, and the predicted head amount Y in the current filling is calculated from the previous head amount A and the previous flow rate B and the current flow rate X. The filling valve is closed when the weight is calculated by the equation and the weight is obtained by subtracting the predicted drop amount Y from the target filling weight. The calculation formula is as follows, and K is a flow rate proportional coefficient.
Y = K * A * X / B + (1-K) * A

JP 09-169394 A

  However, as a result of various studies on the relationship between the flow rate of the filling liquid and the head amount, the inventors have found that the “head amount” in the gravimetric filling device is the flow rate at the time of filling (unit: (Liquid volume per hour) Even if a calculation formula that assumes a direct proportion change even in part is used, and the estimated drop amount is calculated by applying the flow rate at the most recent filling, the filling error with respect to the target weight It has been found that there are many cases where it cannot be made small and an appropriate amount cannot be filled.

  The reason why the flow rate and the drop amount are not necessarily in direct proportion in the filling device using a weight meter is that, for example, the magnitude at which the discharge pressure of the filling liquid into the container acts on the weight meter is the discharge port of the filling nozzle Since the distance varies depending on the distance between the liquid level and the liquid level, there may be a large difference in the accuracy of weight measurement with a weigh scale. For example, when filling with the filling nozzle fixed to the upper part of the container mouth so that the filling liquid falls into the container from a high position, while inserting the filling nozzle into the container and keeping a certain distance from the filled liquid surface There is a large difference in the accuracy of measurement with the weigh scale from the case of raising the filling nozzle.

  Therefore, the present invention always fills the filling liquid with the target weight without excess or deficiency, and also can reduce the variation in the filling amount of the filled product, thereby changing disturbances such as the physical properties of the filling liquid and the filling environment. It is an object of the present invention to provide a liquid filling method and a liquid filling apparatus that can respond quickly.

The first feature of the liquid filling method of the present invention is that the filling amount of the liquid filled in the container from the filling liquid tank via the filling nozzle is measured with a gravimetric meter while the filling liquid tank is filled with the filling nozzle. A liquid filling method for closing and opening a liquid passage of the liquid passage at a constant speed at a predetermined timing to fill the container with a liquid of a target weight, and a plurality of patterns of flow rates in the liquid filling and their flow If a drop characteristic curve consisting of a curve interpolating between a plurality of control points indicating a corresponding relationship with the actual drop amount or a curve approximated to the plurality of control points is not managed, When the container is filled with the liquid, the filling is interrupted at a plurality of patterns of flow rates, and the temporary drop amount flowing out from the filling valve after the closing operation of the filling valve at the time of the interruption is measured. After that, the filling of the container is resumed, the filling valve is closed at a timing when the predetermined weight is obtained by subtracting the temporary drop amount from the target weight for the container, and the filling of the container is performed. The actual drop amount flowing out from the filling valve after the closing operation of the filling valve at the time of the quantitative filling is obtained, and after the measurement of the actual drop amount in the flow rates of the plurality of patterns is completed, the flow rate and the actual amount of each pattern are determined. A drop characteristic curve obtained by interpolating between a plurality of control points indicating a corresponding relationship with the drop amount, or a drop characteristic curve approximated to the plurality of control points is created and managed, and the drop characteristic curve is managed. after obtains the flow rate from the weight gain in a certain time during the filling, on the basis of the difference characteristic curve always closing of the filling valve in response to the flow rate of the filling liquid during filling Obtain a predicted drop amount flowing in Hajimego, loading of the liquid to container, the filling valve is closing operation at the timing when a predetermined weight obtained by subtracting the predicted drop amount from the target weight, perform quantitative filling for the container there to that point to.

According to such a liquid filling method, it is possible to obtain the most appropriate predicted drop amount according to the flow rate at the time of filling that changes in real time using the managed drop characteristic curve, so that the filling liquid is set to the target weight. It becomes possible to fill with high accuracy without excess or deficiency.

The second feature of the liquid filling method of the present invention is that, after the head characteristic curve is managed, when the liquid filling of each container is completed, the flow rate and the actual head just before the filling of the liquid into the container are completed. The amount is measured, and the measured actual head amount is fed back to perform control to update the managed head characteristic curve.

  According to such a liquid filling method, every time the filling of the filling liquid into the container is completed, the actual drop amount is fed back to the drop amount characteristic curve, and the drop amount correction is performed to update the drop characteristic curve. Fills the weight without excess and deficiency, and can quickly respond to disturbance changes such as physical properties of the filling liquid and filling environment.

Further, the first feature of the liquid filling apparatus of the present invention is that a weight meter for measuring the weight of the liquid filled in the container, and a container in which the liquid fed from the filling liquid tank is set in the weight scale. Between a plurality of control points indicating a correspondence relationship between the flow rate and the actual drop amount in the filling of the liquid , a filling valve for opening and closing a liquid passage for leading the liquid of the filling nozzle from the filling liquid tank, When a head characteristic curve consisting of a curve interpolated by connecting or a curve approximated to the plurality of control points is not managed, the container is filled with the liquid at a flow rate of a plurality of patterns of the liquid, respectively. The filling is interrupted when the filling valve is closed, the temporary drop amount flowing out from the filling valve is measured after the closing operation of the filling valve is started, and the target for the container is resumed after the filling of the container is resumed. The filling valve is closed at a timing when the predetermined weight is obtained by subtracting the temporary drop amount from the amount, and the actual drop amount flowing out from the filling valve after starting the closing operation of the filling valve at the time of the quantitative filling is obtained, Interpolating by connecting between a plurality of control points corresponding to the flow rate of liquid and the actual head amount, or creating and managing the head characteristic curve by approximating to the plurality of control points, the head characteristic curve After being managed , based on the head characteristic curve, a head amount determining means for obtaining a predicted head amount corresponding to the flow rate of the filling liquid during filling, and a flow rate conversion for calculating the flow rate from the increased weight within a certain time during filling. means a valve opening and closing control means for performing a pre-Symbol closing the filling valve control,
It is in the point with.

According to the liquid filling apparatus thus constructed, in the flow rate of the plurality of patterns of the liquid (preferably 4 patterns above), to measure the actual drop volume that flows out from the filling valve after closing the start of the filling valve, A drop characteristic curve interpolated by connecting a plurality of control points indicating the correspondence between the flow rate of each pattern and the actual drop amount or a drop characteristic curve approximated to the plurality of control points is created in the drop amount determining means. After the head characteristic curve is managed, the flow rate conversion means detects the flow rate in real time from the increased weight within a fixed time during filling, and the head amount determination means determines the flow rate based on the head characteristic curve. always to previously obtain a predicted drop amount flowing after closing the start of the filling valve according to the flow rate of the filling liquid during filling, in the valve opening and closing control means, of the liquid to the container By closing the filling valve at a timing when the filling amount becomes a predetermined weight obtained by subtracting the predicted head amount from the target weight, the liquid filling method having the first feature described above is executed, and the filling liquid is targeted. It can be filled without excess or deficiency in weight.

The second feature of the liquid filling apparatus of the present invention is that the drop amount determining means includes a flow rate immediately before completion of filling of the liquid into the container and an actual drop amount measured when the filling of the liquid into the individual containers is completed. there of a plurality of control points indicating the correspondence between, on the point of performing control to update the該落difference characteristic curve by reflecting the drop characteristic curve that manages.

  According to the liquid filling apparatus configured as described above, the liquid filling method having the second feature described above is executed, the filling liquid is filled with the target weight without excess or deficiency, and disturbances such as physical properties of the filling liquid and filling environment are caused. Respond quickly to changes.

  As described above, according to the liquid filling method and the liquid filling apparatus of the present invention, the filling liquid can be filled to the target weight without excess or deficiency, and the variation in the filling amount of the filled product can be reduced. There is an excellent effect that it is possible to respond quickly to disturbance changes such as the physical properties of the liquid and the filling environment.

The block diagram which shows the structure in embodiment of the liquid filling apparatus of this invention. Flowchart for explaining control of quantitative filling in the first embodiment of the liquid filling method of the present invention. The flowchart explaining the control for creating the head characteristic curve in the first embodiment of the liquid filling method of the present invention. An example of a drop characteristic curve created in the liquid filling method of the present embodiment An example of table data created by obtaining a head amount corresponding to a flow rate of 1 g / s based on the head characteristic curve of FIG. Flowchart for explaining control of quantitative filling in the second embodiment of the liquid filling method of the present embodiment Graph for explaining an example of drop characteristic curve update control An example of table data created by determining a head amount corresponding to a flow rate of 1 g / s based on each head characteristic curve of FIG. The graph for demonstrating another Example (comparative example) of head characteristic curve update control An example of table data created by obtaining a head amount corresponding to a flow rate of 1 g / s based on each head characteristic curve of FIG.

  The liquid filling apparatus of the present embodiment described below includes a filling liquid tank for storing filling liquid (filling liquid) such as soy sauce, edible oil, and shampoo, and a filling mechanism arranged in a plurality of series in this filling liquid tank. A rotary type or series type liquid filling device is assumed. Since the filling mechanism is configured similarly, only one series of filling mechanisms and a liquid filling method using the filling mechanism will be described, and other filling mechanisms and a liquid filling method using the filling mechanism will be described. Is omitted.

  The present invention is not limited to the rotary or in-line type liquid filling apparatus as described above, and may be a liquid filling apparatus having only a single filling mechanism. Similarly, only a single filling mechanism is available. It may be a liquid filling method using.

<Liquid filling device>
As shown in FIG. 1, the liquid filling apparatus (filling mechanism) of the present embodiment has a load cell 1 as a weighing scale for measuring the weight of a filling liquid filled in a container (not shown) and an internal pressure of a desired value. A filling nozzle 3 that fills a container (not shown) set in the load cell 1 with a filling liquid fed from a filling liquid tank 2 that is controlled so as to be held at a constant level; A filling valve 4 having a known configuration for opening and closing the liquid passage 2a for introducing the filling liquid, and a load cell for controlling the filling valve 4 to be closed at a predetermined timing and a predetermined speed so that the container is filled with a target weight of the filling liquid. And a control unit 5. The filling nozzle 3 and the filling valve 4 may be integrally formed.

  Here, the load cell 1 is connected to a central control device 6 through a communication means such as CC-Link via a flow rate conversion means 5a that constitutes a load cell control unit 5 including an indicator so that signals can be transmitted. When the load cell 1 detects a change in weight, the flow rate conversion means 5a converts the weight (w) into a flow rate. That is, the flow rate conversion means 5a detects the flow rate (for example, in units of 0.1 g / s) from the increased weight within a fixed time during filling, and the weight and flow rate of the filling liquid at that time are detected by the flow rate management unit of the central controller 6. 8 is converted into a digital signal and transmitted.

  The filling valve 4 is connected to valve opening / closing control means 5b constituting the load cell control unit 5, and can be opened and closed by the valve opening / closing control means 5b. The valve opening / closing control means 5b is a container according to the target weight of the filling liquid input from the input unit 9 or the like of the central controller 6 and the predicted head amount acquired from the head amount determining means 7 of the central controller 6 described later. As will be described later, the filling valve 4 is controlled to be closed when the liquid filling amount becomes a predetermined weight obtained by subtracting the predicted drop amount from the target weight.

  The central controller 6 includes a flow rate management unit 8 for storing the flow rate transmitted from the flow rate conversion means 5a, a curve obtained by interpolating between a plurality of control points (points) indicating the correspondence between the flow rate and the actual drop amount, Alternatively, a drop characteristic curve indicating a correspondence relationship between the flow rate and the actual drop amount, which is a curve approximated to the plurality of control points, is managed, and based on the drop characteristic curve, the flow rate of the filling liquid during filling is handled. A head amount determining unit 7 for obtaining a predicted head amount, an input unit 9 such as a touch panel and a key, a display unit 10 such as a liquid crystal panel, and a storage unit 11 for storing various other data are provided.

  In the present embodiment, the head amount determining means 7 of the central controller 6 further includes a curve obtained by interpolating between a plurality of control points indicating the correspondence between the flow rate and the actual head amount, or the plurality of control points. The head characteristic curve can be created by approximating the points. A method for creating a head characteristic curve based on a plurality of control points uses a known method, and a tool for automatically creating the head characteristic curve can also be executed in the central controller 6 by a computer program that has been made public. .

  Further, the filling liquid tank 2 can be adjusted in internal pressure by the pressure adjusting means 13, and the pressure adjusting means 13 is configured to be controlled by the pressure control means 14 of the central controller 6.

Next, two embodiments of the liquid filling method of the present invention will be specifically described.
In the liquid filling method of the present invention, using the liquid filling apparatus configured as described above, the load amount of the liquid filled in the container from the filling liquid tank 2 through the filling nozzle 3 is measured by the load cell 1, The filling valve 4 that opens and closes the liquid passage 2a between the filling liquid tank 2 and the filling nozzle 3 is closed at a predetermined speed at a predetermined timing to fill the container with a target weight of liquid.

In the following description, the actual amount of liquid flowing out from the filling nozzle 3 after starting the closing operation of the filling valve 4 at a certain flow rate is defined as “actual drop amount”, and filling is started after the closing operation of the filling valve 4 at a certain flow rate is started. The amount of liquid predicted to flow out from the nozzle 3 is defined as the “predicted drop amount”. Further, when the actual head amount is measured in order to create a head characteristic curve, which will be described later, the amount of liquid flowing out from the filling nozzle 3 after the start of the closing operation of the filling valve 4 that interrupts the supply of the filling liquid is expressed as “temporary head amount”. Is defined.

  In addition, it is assumed that necessary data such as data relating to the target weight of the filling liquid is input to the liquid filling apparatus in advance.

<Liquid filling method 1>
FIG. 2 is a flowchart illustrating a control flow for quantitative filling in the liquid filling method.

The keep liquid filling method of the present embodiment, sometimes filling the filling liquid of the target weight into the container, the filling liquid, n pattern (n is an integer of 4 or more) to measure the actual drop amount at a flow rate of, the measurement result Therefore, it is necessary to manage a drop characteristic curve consisting of a curve interpolated by connecting a plurality of control points indicating the correspondence between the flow rate and the actual drop amount, or a curve approximated to the plurality of control points.

  Therefore, when the liquid filling apparatus is operated, first, it is confirmed whether or not the drop characteristic curve for filling this time has been created (ST1), and the drop characteristic curve for filling this time is still created and managed. If not (No in ST1), the head characteristic curve is created (ST2). If the drop characteristic curve for filling this time has already been created and managed (Yes in ST1), the step of creating the drop characteristic curve is omitted, and the process proceeds to the next step (ST3).

  FIG. 3 is a flowchart of the control related to the measurement of the head and the creation of the interpolation curve, which is executed in the head amount determination means 7 in order to create the head characteristic curve.

  In this control, the pressure in the filling liquid tank 2 is changed for each measurement in order to set the flow rate of the filling liquid to four patterns. It is desirable to set a plurality of pressures in the filling liquid tank 2 within a range in which a flow rate at the time of actual filling of the filling liquid can be obtained. Therefore, first, the number (n) of patterns to be measured is input as an integer of 4 or more from the input unit 9 of the central controller 6, and the pressure in the filling liquid tank 2 in each pattern is set (ST101). In the present embodiment, it is assumed that the actual drop amount in the flow rate of the filling liquid of four patterns is measured (n = 4), and the pressure in the filling liquid tank 2 is also 0.05 Mpa, 0.06 Mpa, 0.07 Mpa, It is set to 4 levels of approximately equal differential pressure of 0.08 MPa. This setting is appropriately stored in the storage area of the drop amount determining means 7 (including the case of the storage unit 11; the same applies hereinafter).

  Next, the head count n is reset to n = 0 (ST102).

  Subsequently, 1 is added to the current drop count n (ST103).

  Then, the pressure control means 14 controls the pressure adjusting means 13 so that the pressure is set in the pattern (n = 1) managed in the storage area of the head amount determining means 7 to control the inside of the filling liquid tank 2. Is adjusted (ST104).

  Thereafter, the filling valve 4 is opened by the valve opening / closing control means 5b, and the first filling of the filling liquid into the container set in the load cell 1 is started (ST105).

  At the time of filling, the load cell 1 sets the weigh scale to 0 in order to cancel the tare weight when the container is set. By doing so, the positive amount of the filling amount can be detected.

  In this embodiment, in order to create a head characteristic curve, first, when the flow rate conversion means 5a detects that the container is filled with half the target weight (assuming the target weight is 200 g), Once the filling valve 4 is closed, filling is interrupted, and a drop amount (temporary drop amount) at this time is obtained. Then, the filling valve 4 is opened again to resume filling. It should be noted that the amount of the filling liquid supplied first for creating the head characteristic curve is not limited to the half of the target weight described above. The ratio between the amount of filling liquid supplied first and the target weight can be freely set. When the flow rate conversion means 5a detects that the filling liquid of the target weight-temporal drop amount is filled in the container, the filling valve 4 is closed and the first filling is completed (ST106). That is, the filling is completed at the closing timing of the filling valve 4 based on the provisional drop amount.

Then, the actual drop amount under this first filling condition (actual drop amount during drop measurement) is obtained (ST107). The actual drop amount at this time can be obtained by the following equation from the relationship between the final filling liquid amount (actual filling weight), the target weight, and the temporary drop amount.
Actual head drop at head measurement = (actual filling weight-target weight) + temporary head

  Then, the flow rate immediately before closing the filling valve 4 and the actual drop amount at the time of drop measurement are transmitted to the flow rate management unit 8 of the central controller 6 and stored in the storage area of the drop amount determination means 7 via this flow rate management unit 8. (ST108).

  Subsequently, it is confirmed whether or not the head measurement number is the set head measurement number n (four times in the present embodiment, n = 4) (ST109), and the head number measurement number n still set is reached. If not (No in ST109), the process returns to ST103 again, 1 is added to the current drop measurement count n, and the following ST104 to ST108 are repeated.

  When the set number n of heads is reached (Yes in ST109), that is, when n = 4 in the present embodiment, the head amount determining means 7 is displayed on a graph showing the relationship between the head amount and the flow rate. A curve obtained by plotting control points indicating the correspondence between the flow rate and the actual head amount stored in each storage area stored in the storage area and interpolating the control points using a known interpolation method or the like Is created as a drop characteristic curve that can be referred to during filling, or a curve approximated to the control point is created as the drop characteristic curve and stored in the storage area of the drop amount determining means 7 (ST110).

  In FIG. 4, the control point n = 1 (flow rate: 73 g / s, drop amount: 21.5 g) in the first drop measurement with the pressure in the fill liquid tank 2 set to 0.05 Mpa, the fill liquid tank 2 is shown. Control point n = 2 (flow rate: 88 g / s, drop amount: 24.6 g) in the second drop measurement with the inner pressure set to 0.06 Mpa, third time with the pressure in the filling liquid tank 2 set to 0.07 Mpa Control point n = 3 in the head measurement of the current (flow rate: 106 g / s, head amount: 27.7 g), and control point n = 4 in the fourth head measurement in which the pressure in the filling liquid tank 2 is 0.08 Mpa. An example of a drop characteristic curve created by interpolating between (flow rate: 128 g / s, drop amount: 30.7 g) using a known interpolation method or the like is shown. In the drop characteristic curve shown in FIG. 4, a drop characteristic curve assuming a flow rate of 50.0 g / s to 149.0 g / s is created.

  Returning to FIG. 2, in the control for quantitative filling in the liquid filling method, when the load cell control unit 5 confirms that the container is set in the load cell 1 (Yes in ST2), the valve opening / closing control means. The filling valve 4 is opened by 5b, and the filling liquid is supplied from the filling liquid tank 2 into the container through the filling nozzle 4 (ST3).

Your name, load cell 1, in order to cancel the tare weight in the container has been set stage, to set the weight meter to zero. When filling of the filling liquid is started (ST4), the load cell 1 measures the change in the weight of the container, in other words, the filling amount (weight) of the filling liquid filled in the container in real time (ST5).

  Then, the flow rate conversion management means 5a obtains the flow rate at that time in real time from the weight of the filling liquid, and converts the flow rate of the filling liquid into a digital signal and transmits it to the flow rate management unit 8 of the central controller 6 (ST6).

  Subsequently, in the central controller 6, the head amount determining means 7 obtains a predicted head amount corresponding to the current flow rate of the filling liquid transmitted to the flow rate management unit 8 based on the head characteristic curve (ST7). The valve opening / closing control means 5b always obtains the predicted head amount from the head amount determining means 7 of the central controller 6, and the filling amount of the filling liquid into the container changes from the target weight according to the change in the flow rate. Whether or not the predetermined weight obtained by subtracting the predicted head amount is continuously managed (circulation from ST8 No to ST4), and the filling valve 4 is closed when the filling amount of the filling liquid reaches the predetermined weight. Control is performed as follows (ST9).

  Thereafter, it is determined whether or not this work is to be ended (ST10), and when this work is continued (No in ST10), the process returns to ST3 again, and quantitative filling is performed on the next supplied container.

  Also in the present embodiment, the filling liquid flows out from the start of the closing operation of the filling valve 4 to the fully closed state. However, in the liquid filling method of the present embodiment, this outflow amount is calculated as the predicted drop amount. Therefore, the liquid can be accurately filled into the container without excess or deficiency with respect to the target weight.

Thus, using the liquid filling apparatus of this embodiment, the flow rate at the time of filling is measured in real time by the load cell 1, and the drop characteristic curve managed is used, and the most appropriate according to the flow rate at the time of filling that changes in real time. A liquid filling method can be performed in which a predicted drop amount is obtained and the filling valve 4 is closed in anticipation of the predicted drop amount before the filling amount of the container reaches the target weight. As a result, even if the flow rate changes for some reason just before the closing operation of the filling valve 3, an expected drop amount corresponding to the change in the flow rate is obtained and reflected in the acquisition of the closing operation timing of the filling valve 4 in real time. Therefore, it becomes possible to fill the filling liquid with the target weight without excess or deficiency.

  The head amount determining means 7 creates and stores table data in which the flow rate is associated with the predicted head amount based on the head characteristic curve, and in the liquid filling method, based on the head characteristic curve. It is also possible to create table data in which the flow rate is associated with the predicted drop amount, and obtain the predicted drop amount according to the flow rate at the time of filling with reference to the table data. FIG. 5 is an example of table data in which a drop amount corresponding to a flow rate of 100 patterns in units of 1.0 g is obtained based on the drop characteristic curve of FIG.

  In this way, the predicted drop amount corresponding to the flow rate at the time of filling is stored as table data, and by referring to this table data, the predicted drop amount corresponding to the filling flow rate is calculated each time based on the drop characteristic curve. Compared with the case where the required control is performed, the process of determining the closing operation timing of the filling valve can be performed rapidly in a very short time, and the liquid filling amount can be controlled more strictly.

<Liquid filling method 2>
FIG. 6 is a flowchart for explaining a flow of control for quantitative filling in the liquid filling method of the present embodiment. Liquid filling method of the present embodiment measures a liquid filling method in the above embodiment shown in FIG. 2, upon completion the filling of the liquid to container, the flow rate and the actual drop volume in the filling immediately before completion of the liquid into the container The difference is that control is performed by feeding back the measured actual head amount and updating the managed head characteristic curve.

  The steps common to ST1 to ST9 in the above-described embodiment shown in FIG. 2 are shown in FIG. 6 as ST21 to ST29, respectively, and the description thereof is omitted, but in the liquid filling apparatus of this embodiment, the flow rate conversion is performed. The means 5a transmits not only the flow rate but also the weight of the filling liquid at that time in the form of a digital signal to the flow rate management unit 8 of the central controller 6, and in the steps ST25 and ST26, the filling to be filled in the container The filling amount (weight) of the liquid is measured in real time (ST25), the flow rate conversion means 5a obtains the flow rate in real time from the weight of the filling solution in real time, and the weight and flow rate of the filling solution are digitally signaled to the flow rate management unit 8. Assume that the data is transmitted (ST26).

  In the liquid filling method of this embodiment, after the filling valve 4 is closed at a timing when the filling amount of the liquid into the container becomes a predetermined weight obtained by subtracting the predicted drop amount from the target weight (ST29), the drop amount determining means 7 Then, based on the weight transmitted to the flow rate management unit 8, the actual drop amount under the filling condition of the filling liquid into the container is obtained (ST30).

The actual drop amount at this time (normal drop during normal filling) is the final filling liquid amount (actual filling weight) and the weight when the filling valve starts to be closed, that is, the weight obtained by subtracting the predicted falling amount from the target weight. From the relationship, it can be calculated as follows.
Actual drop amount at normal filling = Actual filling weight-(Target weight-Expected drop amount)

  Then, using the point indicating the correspondence between the flow rate immediately before closing the filling valve 4 and the actual drop amount during normal filling as a correction point, the drop characteristic curve is updated by feeding back (reflecting) the drop characteristic curve. The head amount is corrected, and the updated head characteristic curve is stored (ST31).

  Thereafter, it is determined whether or not this work is to be ended (ST32). If this work is continued (No in ST32), the process returns to ST23 again, and the filling liquid is supplied to the container to be supplied next in the processes up to ST31. And the correction control for updating the head characteristic curve (hereinafter referred to as head characteristic curve update control) is performed again.

  Thus, in the liquid filling method 2 of the present embodiment, the drop characteristic curve is obtained by performing the drop characteristic curve update control for feeding back the actual drop amount and updating the drop characteristic curve every time the filling liquid is filled into the container. Since it becomes a value closer to the true value that responds promptly to changes in the disturbance at that time, it is possible to fill the filling liquid with a high accuracy without exceeding the target weight.

<Example 1 of drop characteristic curve update control>
Here, a specific method of the head characteristic curve update control will be described.
FIG. 7 shows the filling control using the head characteristic curve shown in FIG. 21 shows an example of correction assuming a case where the process of setting the actual drop amount at the normal filling at the flow rate of 70.0 g / s shown in 21 to 22.8 g is performed five times in succession. Times through 5 show the drop characteristic curves after the respective correction processes. FIG. 8 is an example of table data in which 100 head amounts corresponding to a flow rate of 1.0 g / s are obtained based on a head characteristic curve corrected after each processing.

  In the drop characteristic curve update control shown in FIG. 7 and FIG. 8, the correction point (flow rate 70.0 g / s, actual drop amount 22. Extracting a plurality of points indicating a drop amount corresponding to a flow rate of 10.0 g / s with a flow rate of 8 g) as a reference, and creating a drop characteristic curve composed of an approximate curve using the plurality of points as control points. Thus, the head characteristic curve managed by the head amount determining means 7 is updated.

  That is, in the first correction, the drop characteristic curve shown in FIG. 4 and the table data shown in FIG. 5 are corrected (updated), and the correction point flow rate of 70.0 g / s is used as a reference in units of 10.0 g / s. Extract points. That is, in this embodiment, a point indicating a drop amount of 15.8 g corresponding to a flow rate of 50.0 g / s, a point indicating a drop amount of 18.4 corresponding to a flow rate of 60.0 g / s, and a flow rate of 70.0 g / s. A point indicating a head amount 20.8 g corresponding to a flow rate, a point indicating a head amount 23.0 g corresponding to a flow rate 80.0 g / s, a point indicating a head amount 25.0 g corresponding to a flow rate 90.0 g / s, a flow rate 100 A point indicating a head amount of 26.8 g corresponding to 0.0 g / s, a point indicating a head amount of 28.4 g corresponding to a flow rate of 110.0 g / s, and a head amount of 29.8 g corresponding to a flow rate of 120.0 g / s are shown. A point indicating a drop amount of 31.0 g corresponding to a point, a flow rate of 130.0 g / s, and a point indicating a flow rate of 32.0 g corresponding to a flow rate of 140.0 g / s are extracted.

  Among the 10 point drop amounts, the 20.8 g drop amount at the correction point of 70.0 g / s is set to 22.8 g of the correction value, and a drop characteristic curve is created using these 10 points as control points (see FIG. 7), the head characteristic curve managed by the head amount determining means 7 is updated by replacing the new head characteristic curve with the head characteristic curve being managed. Based on the drop characteristic curve created by the first correction, the drop amount corresponding to the flow rate of 10.0 g is as shown in the “first” table data of FIG.

  In this way, the head characteristic curve gradually corresponds to the flow rate that does not need to be corrected by performing head amount correction by feeding back the actual head amount every time the container is filled with the filling liquid and updating the head characteristic curve. The head can be corrected to a head characteristic curve that can determine the head amount to be.

  In the second correction, 10 points are extracted in the same manner, with the drop characteristic curve shown in “First time” in FIG. 7 and the table data in “First time” in FIG. 8 being corrected (updated). To do.

  Of the 10 points of drop, the 21.4 g of the drop at a flow rate of 70.0 g / s, which is the correction point, is set to 22.8 g of the correction value, and a drop characteristic curve is created using these 10 points as control points ( 7), the head characteristic curve managed by the head amount determination means 7 is updated.

  The drop amount corresponding to the flow rate of 1.0 g / s based on the drop characteristic curve created by the second correction is as shown in the “second” table data in FIG.

  Similarly, every time when the actual drop amount during normal filling at the flow rate of 70.0 g / s is detected to be 22.8 g, the third to fifth corrections are performed and the drop characteristic curve is updated. (See the drop characteristic curves shown in “third” to “fifth” in FIG. 7 and the table data shown in “third” to “fifth” in FIG. 8, respectively).

  In this embodiment, the drop amount at the correction point of 70.0 g / s is 21.8 g after the second correction, 22.1 g after the third correction, and 22.4 g after the fourth correction. It became 22.5 g after the fifth correction.

  In this way, the head characteristics including an approximate curve having a control point with a plurality of four or more points (the flow rate is preferably equal) including the correction point from the head characteristics curve under management as a reference for correction. By creating a curve and updating the head characteristic curve managed by the head amount determining means 7, it is possible to perform head amount correction that greatly reflects the numerical value of the correction point.

<Embodiment 2 of the drop characteristic curve update control (comparative example)>
In the head characteristic curve update control shown in FIG. 9 and FIG. 10, the correction point (flow rate 70.0 g / s, actual head amount 22.8 g at normal filling) is calculated from the head characteristic curve currently being managed as a reference for correction. 100 points indicating a head amount corresponding to a flow rate of 1.0 g / s based on the flow rate of), and a head characteristic curve composed of an approximate curve using the 100 points as control points is created. The head characteristic curve managed by the head amount determining means 7 is updated.

  In other words, the first correction includes a correction point flow rate of 70.0 g / s in units of 1.0 g / s, with the drop characteristic curve shown in FIG. 4 and the table data shown in FIG. 5 being corrected (updated). Extract 100 points from 50.0 g / s to 149.0 g / s.

  A head characteristic curve is created by correcting the head amount 20.8 g at the correction point of 70.0 g / s to 22.8 g out of the head amount of the 100 points (shown in “first” in FIG. 9). The head characteristic curve managed by the head amount determining means 7 is updated by replacing the head characteristic curve thus created with the head characteristic curve currently being managed as a reference for correction.

  The drop amount corresponding to the flow rate of 1.0 g based on the drop characteristic curve created by the first correction is as shown in the “first” table data in FIG.

  In the second correction, the drop characteristic curve shown in “First time” in FIG. 9 and the table data of “First time” in FIG. Then, a head characteristic curve was created by correcting the head amount 20.8 g at the correction point of 70.0 g / s to 22.8 g (refer to the curve shown in “second time” in FIG. 9), and this head was created. The head characteristic curve managed by the head amount determining means 7 is updated by substituting the head characteristic curve currently being managed as a correction reference with the characteristic curve.

  The head amount corresponding to the flow rate in units of 1.0 g based on the head characteristic curve created by the second correction is as shown in the “second” table data in FIG.

  Similarly, every time the actual drop amount during normal filling at the flow rate of 70.0 g / s is detected to be 22.8 g, the third to fifth corrections are performed, and the drop characteristic curve is updated ( (See the drop characteristic curves shown in “third” to “fifth” in FIG. 9 and the table data shown in “third” to “fifth” in FIG. 10, respectively).

  In the drop characteristic curve update control of the second embodiment, the drop amount at the correction point of 70.0 g / s is 20.9 g after the second correction, 20.9 g after the third correction, It was 21.0 g by the fourth correction, and 21.0 g by the fifth correction.

  Thus, in the drop characteristic curve update control, the correction point that actually needs to be reflected is only one control point among the 100 control points for creating the drop characteristic curve. Is difficult to be reflected in the head characteristic curve, and it is necessary to repeat many fillings until the head characteristics are updated to the correct head characteristic curve.

  Therefore, in the drop characteristic curve update control of the liquid filling according to the present invention, the drop characteristic curve is corrected by using, as control points, a plurality of four or more points including correction points from the managed drop characteristic curve serving as a correction reference. I found it desirable.

<Other embodiments>
The liquid filling device (filling mechanism) interpolates between the control points indicating the corresponding relationship between the required time per unit weight increase of the filling liquid immediately before closing the filling valve 4 and the actual drop amount in the drop amount determining means 7. A drop characteristic curve consisting of a curve or an approximate curve approximated to the plurality of control points is created and managed, and based on this drop characteristic curve, a predicted drop amount corresponding to the flow rate of the filling liquid is obtained, and the valve opening / closing In the control means 5b, a predicted drop amount corresponding to the required time per unit weight increase of the filling liquid detected by the flow rate conversion means 5a is obtained from the drop amount determination means 7, and the predicted drop amount is subtracted from the target weight. The filling valve 4 may be controlled to be triggered by the load cell 1 measuring the predetermined weight.

  In short, the drop characteristic curve is created with the reciprocal of the flow rate, but the amount of filling can be managed more finely than when the predicted head amount is managed by the flow rate. The target weight can be filled with high accuracy without excess or deficiency, and variations in the filling amount of the filled product can be reduced.

  Even in this case, every time the container is filled with the filling liquid, the actual head amount can be fed back to the head characteristic curve, and head amount correction can be performed to update the head characteristic curve. By performing the head amount correction in this way, the filling liquid can be filled to the target weight without excess and deficiency, and it is possible to quickly respond to disturbance changes such as the physical properties of the filling liquid and the filling environment.

  Furthermore, the head amount determining means 7 creates and stores table data in which the required time per unit weight increase of the filling liquid and the predicted head amount are associated based on the head characteristic curve, and stores the table data. The table data in which the required time per unit weight increase of the liquid and the predicted head amount are associated with each other based on the head characteristic curve, and the predicted head amount corresponding to the required time per unit weight increase during filling is calculated. You may make it obtain | require with reference to the said table data.

  Even in this case, the process of determining the closing operation timing of the filling valve can be performed in a very short time compared to the case where the control for obtaining the predicted head amount corresponding to the filling flow rate is performed on the basis of the head characteristic curve. This makes it possible to control the liquid filling amount more strictly.

  Furthermore, in the above-described first example of the drop characteristic curve update control, when determining the control point for creating the drop characteristic curve, the correction point of this time is determined from the currently managed drop correction curve serving as a reference for correction. Although a plurality of points indicating a head amount corresponding to a flow rate of 10.0 g / s with respect to the flow rate of 10 are extracted, the method for determining the control point is not limited to this method. For example, a point indicating a drop amount corresponding to the flow rate of the correction point may be added to a plurality of predetermined points, and these points may be used as control points. Specifically, 50.0 g / s, 60.0 g / s, 70.0 g / s, 80.0 g / s, 90.0 g / s, 100.0 g / s, 110.0 g / s, 120 in advance. A point indicating a drop amount corresponding to a flow rate of 0.0 g / s and 130.0 g / s is used as the control point, and a point indicating a drop amount corresponding to the correction point (for example, a flow rate of 67. g) is used. If 0 g / s is a correction point, a new drop characteristic curve may be created using a control point to which a drop amount corresponding to this flow rate is also added. According to the drop characteristic curve update control, the correction point at this time can be largely reflected in the new drop characteristic curve (the “weight” of the correction point is increased), so that the correction effect can be obtained more quickly. .

  In addition, this invention is not restrict | limited at all to the above-mentioned embodiment, It is included by this invention unless it is contrary to the summary of this invention.

1 Load cell (Weigh scale)
2 Filling liquid tank 3 Filling nozzle 4 Filling valve 5 Load cell control unit 5a Flow rate conversion means 5b Valve opening / closing control means 6 Central controller 7 Head amount determination means 8 Flow rate management part 9 Input part 10 Display part 11 Storage part 13 Pressure adjustment means 14 Pressure control means

The first feature of the liquid filling method of the present invention is that a plurality of series of filling mechanisms each provided with a filling nozzle are arranged in one filling liquid tank, and the filling nozzles from the filling liquid tank are filled in each series of filling mechanisms. The filling valve that opens and closes the liquid passage between the filling liquid tank and the filling nozzle is closed at a constant speed at a constant speed while measuring the filling amount of the liquid filled in the container with a weighing scale. A liquid filling method for filling a liquid with a target weight into the container, and a curve obtained by interpolating between a plurality of control points indicating a correspondence relationship between a plurality of patterns of flow rates and their actual drop amounts in the filling of the liquid, Alternatively, when a head characteristic curve composed of curves approximated to the plurality of control points is not managed, the liquid is filled in the container at the flow rate of the plurality of patterns of the liquid, respectively. The filling is interrupted, and after the closing operation of the filling valve at the time of the interruption is started, the temporary drop amount flowing out from the filling valve is measured, and then the filling of the container is resumed and the provisional weight of the container from the target weight is resumed. The filling valve is closed at a timing when the predetermined weight is obtained by subtracting the head amount, and the filling of the container is performed, and after the closing operation of the filling valve at the time of the filling is started, the actual flow out of the filling valve is performed. A head characteristic curve obtained by calculating a head amount and then interpolating between a plurality of control points indicating the correspondence between the flow rate of each pattern and the actual head amount when measurement of the actual head amount at the flow rate of the plurality of patterns is completed. Alternatively, a drop characteristic curve approximated to the plurality of control points is created and managed, and after the drop characteristic curve is managed, the weight increased within a certain time during filling From the drop characteristic curve, the estimated drop amount that flows out after starting the closing operation of the filling valve according to the flow rate of the filling liquid being filled is obtained. The filling valve is closed at the timing when the predetermined weight is obtained by subtracting the predicted drop amount from the above, and the quantitative filling of the container is executed.

The first feature of the liquid filling apparatus of the present invention is a liquid filling apparatus constituting each of a plurality of series of filling mechanisms arranged for one filling liquid tank , and is filled in a container. liquid guiding a weighing scale for measuring the weight of the liquid, a filling nozzle for filling the filling liquid in a container of liquid to be fed is set to the weighing scale from the tank, the liquid in the filling nozzle from the filling liquid tank From a filling valve for opening and closing a passage and a curve interpolating between a plurality of control points indicating the correspondence between the flow rate and the actual drop amount in filling the liquid, or a curve approximated to the plurality of control points When the drop characteristic curve is not controlled, the filling is interrupted when the container is filled with the liquid at the flow rates of the plurality of patterns of the liquid, and the closing operation of the filling valve at the time of the interruption is performed. Open After the start, the amount of temporary drop flowing out from the filling valve is measured, and after the filling of the container is resumed, the filling valve is closed at a timing when the container reaches a predetermined weight obtained by subtracting the temporary drop amount from the target weight. The actual drop amount flowing out from the filling valve after starting the closing operation of the filling valve at the time of the quantitative filling is obtained, and a plurality of control points corresponding to the liquid flow rate and the actual drop amount are connected. Interpolate or approximate the plurality of control points to create and manage the head characteristic curve.After the head characteristic curve is managed, the flow rate of the filling liquid during filling is calculated based on the head characteristic curve. Drop amount determining means for obtaining a corresponding predicted drop amount, flow rate conversion means for calculating a flow rate from an increased weight within a predetermined time during filling, and valve opening / closing control means for performing control for closing the filling valve; , In the point with.

Claims (4)

  The filling valve that opens and closes the liquid passage between the filling liquid tank and the filling nozzle is constant at a predetermined timing while measuring the filling amount of the liquid filling the container from the filling liquid tank through the filling nozzle with a weighing scale. A liquid filling method in which the container is filled with a target weight of liquid by closing at a high speed, and before the start of the main operation of filling the container with the liquid of the target weight, the liquid is flowed in a plurality of patterns in advance. A drop characteristic curve obtained by measuring the actual drop amount flowing out from the filling valve after starting the closing operation of the filling valve and interpolating between a plurality of control points indicating the correspondence between the flow rate of each pattern and the actual drop amount, or Then, a head characteristic curve approximated to the plurality of control points is created and managed, and during this work, a flow rate is obtained from an increased weight within a certain time during filling, and based on the head characteristic curve, At the time, the estimated drop amount flowing out after the start of the closing operation of the filling valve according to the flow rate of the filling liquid being filled was obtained, and the liquid filling amount into the container became a predetermined weight obtained by subtracting the predicted drop amount from the target weight A liquid filling method, wherein the filling valve is closed at a timing.   At the completion of filling of the liquid into each container in this work, the flow rate and the actual drop amount immediately before the completion of filling the container are measured, and the measured actual drop amount is fed back to manage the drop characteristic curve that is managed The liquid filling method according to claim 1, wherein control for renewing is performed. A weigh scale for measuring the weight of the filling liquid filled in the container;
A filling nozzle that fills a container set in the weighing scale with a liquid fed from a filling liquid tank;
A filling valve for opening and closing a liquid passage for guiding the filling nozzle liquid from the filling liquid tank;
Create and manage a drop characteristic curve consisting of a curve interpolating between a plurality of control points corresponding to the flow rate and the actual drop amount, or a curve approximated to the plurality of control points, and managing the drop characteristic Based on the curve, a head amount determining means for obtaining a predicted head amount corresponding to the flow rate of the filling liquid during filling,
A flow rate conversion means for calculating a flow rate from an increased weight within a certain time during filling,
A valve opening / closing control means for controlling the closing of the filling valve triggered by the weight meter measuring a predetermined weight obtained by subtracting the expected head amount from a target weight;
A liquid filling apparatus comprising:   The drop amount determining means manages a plurality of control points for managing a plurality of control points indicating the correspondence between the flow rate immediately before completion of filling of the liquid into the container and the actual drop amount measured when the filling of the liquid into the container is completed. The liquid filling apparatus according to claim 3, wherein control is performed so as to reflect the difference in the characteristic curve and update the head characteristic curve.