JP4440610B2 - Weight-type filling apparatus and weight-type filling method - Google Patents

Description

  The present invention relates to a weight-type filling device and a weight-type filling method, and in particular, for example, after supplying an object to be measured to a predetermined target weight to a tare placed on a weighing means, the supplied object to be weighed. The present invention relates to a weight-type filling device in which a tare is removed from a weighing means together with an object, and a filling method using the weight-type filling device.

In various weighing devices including a weight-type filling device, the natural vibration of the weighing means such as a load cell itself becomes noise and greatly affects the weighing accuracy. The frequency of the natural vibration, that is, the natural frequency varies depending on the magnitude of the load applied to the measuring means. As a technique for reducing the influence of such natural vibration, there has been conventionally disclosed in Patent Document 1, for example. . According to this prior art, a digital variable band elimination filter to which a weighing signal output from the weighing means is supplied is provided. Then, a zero point measurement characteristic constant for giving the filter a characteristic capable of removing a natural vibration component when no article is loaded on the weighing means, and an article having a weight close to a predetermined reference weight. A characteristic constant for measurement for providing the filter with a characteristic capable of removing the natural vibration component when loaded on the filter is prepared. In such a configuration, when no article is loaded on the weighing means, the zero-point measurement characteristic constant is input to the filter, and when the article is loaded on the weighing means, the measurement characteristic constant is input to the filter. Accordingly, the natural vibration component is effectively removed and high weighing accuracy is obtained when the article is not loaded and when the article is loaded. Note that Patent Document 1 also discloses that the technique can be applied to a weight-type filling device (quantitative filling machine).
JP-A-3-21826

  By the way, in the weight-type filling device, a tare such as a bottle is placed on the weighing means, and after the tare is filled with the object to be weighed, the tare is removed from the weighing means together with the filled object to be weighed. There are things. In such a weight type filling device, in order to realize so-called quantitative filling in which an object to be weighed is filled so as to have a predetermined weight with respect to the tare, it is necessary to accurately grasp the tare weight as a reference. On the other hand, in the weight-type filling device disclosed in Patent Document 1, it is assumed that a so-called weighing hopper in which an object to be weighed is directly loaded thereon is used as the weighing means. Therefore, when trying to measure the weight of the object to be weighed by such conventional technology, the natural frequency of the weighing means is affected by the weight of the tare placed separately from this, and the weight of the object to be weighed is reduced. It becomes impossible to measure accurately. In other words, the conventional technique has a problem that high-precision quantitative filling cannot be performed in a weight-type filling device configured to add or remove a tare together with an object to be weighed. This problem becomes more prominent as the tare weight increases.

  In view of this, an object of the present invention is to make it possible to realize high-precision quantitative filling in a weight-type filling device configured to add or remove a tare together with an object to be weighed.

The first invention is provided with weighing means on which a tare is placed, and after the tare is placed on the weighing means and the object to be weighed is supplied to the tare in a predetermined target weight, In a weight-type filling device configured to remove a tare from a weighing means together with a weighing object, a filtering means for performing a filtering process according to a selected filter constant on a weighing signal output from the weighing means, an initial load of the weighing means, and the weighing A first setting means having a first constant determined based on a spring constant of the means and a standard weight of the tare, an initial load, a spring constant, a standard weight, and at least one reference weight Second setting means in which at least one second constant is set, and a tare is placed on the weighing means, and the first constant is used as a filter constant in a state where an object to be weighed is not supplied to the tare. In the state where the tare is placed on the weighing means and the weight of the object to be weighed supplied to the tare is substantially equal to one of the reference weights, the second constant corresponding to the reference weight is used as the filter constant. And selecting means for selecting the filter constant as selected.

That is, in the first invention, when the tare is placed on the weighing means and the object to be weighed is not supplied to the tare, in other words, the load applied to the weighing means is the initial load and the tare. The first constant determined based on the initial load, the spring constant of the weighing means, and the standard weight of the tare is selected as a filter constant for measurement when the weight is the weight. And the filter process according to the said 1st constant is performed with respect to the measurement signal output from a measurement means by the filter means. Therefore, at this time, the natural vibration of the frequency according to the initial load, the spring constant, and the tare weight is included in the measurement signal, but the natural vibration component included in the measurement signal is effectively reduced by the filter processing. Removed. On the other hand, when the tare is placed on the weighing means and the weight of the object to be weighed supplied to the tare is substantially equal to one of the reference weights, in other words, the load applied to the weighing means is Based on the initial load, the spring constant, the tare weight, and the weight of the object to be weighed close to one reference weight, based on the initial load, the spring constant, the standard weight of the tare, and the one reference weight. The second constant determined in this way is selected as the filter constant. Therefore, at this time, the measurement signal includes the natural vibration of the frequency according to the initial load, the spring constant, the tare weight, and one reference weight. However, the natural vibration component included in the measurement signal is the second vibration component. It is effectively removed by filtering according to a constant. That is, the influence of the natural vibration generated by the weighing means itself is effectively reduced both when the tare is placed on the weighing means and when the object to be weighed is supplied to the tare.

  Note that, when the tare is placed on the weighing means and the object to be weighed is not supplied to the tare, strictly speaking, it is necessary to accurately measure the tare weight. Say that. In other words, at least when the tare weight needs to be accurately measured, the first constant is actually selected as the filter constant. Therefore, for example, the first constant before the tare is placed on the weighing means. May be selected as the filter constant. In addition, when the tare is placed on the weighing means and the weight of the object to be weighed supplied to the tare is substantially equal to one of the reference weights, strictly, the tare is supplied to the tare. This refers to when it is necessary to accurately measure the weight of an object. In other words, when the weight of the object to be weighed supplied to the tare is substantially equal to one of the reference weights, the second constant corresponding to the reference weight is actually selected as the filter constant. For example, the second constant corresponding to the reference weight may be selected as the filter constant before the weight of the object to be weighed supplied to the tare becomes substantially equal to one of the reference weights.

  The reference weight described above may include a target weight. If it does in this way, the final weight of the to-be-measured object supplied to the tare can be measured correctly.

  Moreover, you may further provide the switching means which switches the supply amount per unit time of the to-be-measured item to a tare. In this case, it is desirable that the reference weight includes at least one switching weight serving as a reference when the supply amount is switched. In this way, it is possible to accurately determine whether or not the weight of the object to be weighed supplied to the tare has reached the switching weight. In other words, it is possible to accurately grasp the switching timing of the supply amount.

  In addition, the natural frequency of the measuring means when a known first weight is applied to the object mounting portion of the measuring means, for example, the mounting table, and a known second weight different from the first weight are applied. A determining means for determining the first constant and the second constant may be provided based on an arithmetic expression including the natural frequency of the weighing means when it is being performed. That is, the natural frequency of the weighing means is related to a so-called initial load applied to the weighing means such as a mounting table from the beginning. The natural frequency is also related to the spring constant of the measuring means itself. Therefore, in order to prepare the accurate first constant and the second constant so as to effectively remove the natural vibration component included in the measurement signal as described above, it is necessary to accurately obtain the initial load and the spring constant. Therefore, the determining means determines the initial load and the spring constant based on the natural frequency actually measured when the first weight is applied and the natural frequency actually measured when the second weight is applied. Ask for. More specifically, the initial load and the spring constant are obtained based on a binary simultaneous equation representing the relationship between each natural frequency and an unknown initial load and a spring constant. An arithmetic expression including these initial load and spring constant, in other words, an arithmetic operation indirectly including the natural frequency when the first weight is applied and the natural frequency when the second weight is applied. Based on the equation, appropriate first and second constants are obtained. Note that the first weight (or the second weight) may be zero. That is, the time when the first weight (or the second weight) is applied may be when no object is placed on the object placement portion.

The second invention includes a procedure in which the tare is removed from the weighing means together with the supplied weighing object after the weighing object is supplied to the tare placed on the weighing means so as to have a predetermined target weight. In the gravimetric filling method, based on a filtering process in which a weighing signal output from the weighing means is subjected to a filtering process according to a selected filter constant, an initial load of the weighing means, a spring constant of the weighing means, and a standard weight of the tare. A selection step of selecting any one of at least one second constant determined based on the first constant and the initial load, the spring constant, the standard weight, and the at least one reference weight determined as the filter constant. To do. In the selection process, when the tare is placed on the weighing means and the object to be weighed is not supplied to the tare, the first constant is selected as the filter constant, and the tare is placed on the weighing means. In addition, when the weight of the object to be weighed supplied to the tare is substantially equal to one of the reference weights, the second constant corresponding to the reference weight is selected as the filter constant. Furthermore, the natural frequency of the weighing means when the known first weight is applied to the mounting table of the weighing means and the unique characteristic of the weighing means when the known second weight different from the first weight is applied. Determining an initial load and a spring constant of the measuring means based on the frequency, and determining a first constant and a second constant based on an arithmetic expression including the initial load and the spring constant. It is a feature.

  That is, the second invention is a method invention corresponding to the first invention, and thus has the same effect as the first invention.

  According to this invention, when only the tare is placed on the weighing means and when the object to be weighed is supplied to the tare, the influence of the natural vibration of the weighing means itself is effectively reduced. Is done. Therefore, it is possible to accurately grasp the tare weight serving as a reference and the weight of the object to be weighed supplied to the tare, and therefore, more accurate than the above-described conventional technology that cannot accurately grasp the tare weight. A quantitative filling can be realized.

  An embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the weight-type filling device 10 according to this embodiment is for quantitatively filling a predetermined container 12 such as a bottle with a predetermined liquid as an object to be weighed, for example, a beverage, In order to cope with mass production, N (N: plural) units 14, 14,... Of the same type are provided.

  Each unit 14 is provided with a mounting table 16 on which the container 12 is mounted, a weighing machine 18 as a weighing unit to which the mounting table 16 is coupled, and a distance above the weighing machine 18. And a valve 20 as supply means for supplying a beverage to the container 12. In addition, a stand 22 for supporting the container 12 placed on the placement table 16 is provided in the vicinity of the placement table 16. In this embodiment, N = 36, that is, 36 units 14, 14,... Are provided. Each unit 14, 14,... Is assigned an individual identification number from 1 to N.

  As shown in FIG. 2, each unit 14, 14,... Is disposed at a portion near the periphery of the disc-shaped turntable 24 at equal intervals along the periphery, that is, every 10 degrees (= 360 degrees / N). Have been placed. The turntable 24 rotates about the rotation shaft 26 in the direction indicated by the arrow 100 in FIG. 2 (clockwise in FIG. 2) together with the rotation shaft 26. As the turntable 24 rotates, the units 14, 14,. The above identification numbers are assigned to the units 14, 14,... So that the values n (n = 1 to N) increase sequentially in the counterclockwise direction in FIG.

  Returning to FIG. 1, the upper end portion of the rotating shaft 26 is located at a position higher than each unit 14, 14,... (Each valve 20, 20,...). A shaped storage tank 28 is fixed. This storage tank 28 is for temporarily storing beverages, and N pipes 30, 30,... Are radially connected to the lower part of the side wall thereof. Are individually coupled to the ends of the pipes 30, 30,... Therefore, the beverage in the storage tank 28 flows through the pipes 30, 30,... To the valves 20, 20,. And a drink is supplied to each container 12,12, ... via these valves 20,20, .... In addition, when the storage amount of the beverage in the storage tank 28 becomes a certain amount or less, the storage tank 28 is automatically replenished with the beverage from a replenishment tank (not shown).

  On the other hand, the lower end of the rotary shaft 26 is positioned below the turntable 24 in a state of passing through the center of the turntable 24. A motor 34 as a driving unit is coupled to the lower end portion of the rotating shaft 26 via a gear mechanism 32. The motor 34 is controlled by a controller 36 described later, and the rotating shaft 26 rotates through the gear mechanism 32 when the motor 34 is driven. The gear mechanism 32 generates one pulse every time the rotating shaft 26 makes one rotation, in other words, for detecting a rotation reference (origin) provided at one place on the periphery of the rotating shaft 26. In other words, an encoder 38 for detecting the rotation reference is coupled. In addition to the encoder 38, the gear mechanism 32 is also coupled with an encoder 40 for detecting rotation angle, which generates α × N (α: natural number) pulses each time the rotating shaft 26 makes one rotation. Has been. The output pulses of these encoders 38 and 40 are input to the controller 36. The controller 36 includes a data output terminal 42 for outputting raw load data Wy [n] to be described later, and the raw load data Wy [n] is observed at the data output terminal 42. For example, a digital recorder 44 can be connected.

  The controller 36 will be described in more detail. As shown in FIG. 3, the controller 36 includes a CPU (Central Processing Unit) 360. The data output terminal 42 described above is connected to the CPU 360 via a data output circuit 362 as an interface circuit. The controller 36 also has a pulse input circuit 364 as an interface circuit between the encoders 38 and 40, and output pulses of the encoders 38 and 40 are sent to the CPU 360 via the pulse input circuit 364. Entered. The CPU 360 recognizes the rotation angle of the rotary shaft 26 from these output pulses, and consequently recognizes the current position of each unit 14, 14. And based on this recognition result, the positional data mentioned later for every unit 14 is produced | generated.

  Further, the controller 36 includes a motor control circuit 366 as an interface circuit with the motor 34 and an external control circuit 368 as an interface circuit with an external device such as a carry-in conveyor 50 (see FIG. 2) described later. These are also connected to the CPU 360. The CPU 360 is also connected with an operation key 370 as an operation unit, a liquid crystal display 372 as a display unit, and a memory 374 in which a so-called control program for controlling the operation of the CPU 360 is stored. The memory 374 also functions as a first storage unit that stores parameters such as a tare measurement time Tr described later.

  Further, the controller 36 can communicate with each weighing machine 18, 18,... Of each unit 14, 14,... Individually, and each weighing machine 18 is realized in order to realize such a communication function. , 18,... Has a communication circuit 376 as an interface circuit. This communication circuit 376 is also connected to the CPU 360.

  On the other hand, as shown in FIG. 4, each weighing machine 18 has, for example, a strain gauge type load cell 180, and the mounting table 16 is coupled to the load cell 180. The load cell 180 generates a voltage measurement signal corresponding to the magnitude of the load Wy [n] applied to the load cell 180. The load Wy [n] includes not only the weight Wx [n] of the article placed on the mounting table 16 such as the container 12 described above but also the load cell 180 like the weight of the mounting table 16 itself. The so-called initial load Wi [n] applied from the beginning is also included. The measurement signal generated by the load cell 180 is amplified by the amplification circuit 182 and then input to the A / D conversion circuit 184. The A / D conversion circuit 184 converts the input weighing signal into raw load data that is a digital signal (hereinafter, this raw load data is also represented by the symbol Wy [n]) at a predetermined sampling period Tc. . The converted raw load data Wy [n] is input to the CPU 186. Note that the sampling period Tc of the A / D conversion circuit 184 is, for example, about 1 ms.

  The CPU 186 constitutes a moving average filter 188 as filter means as shown in FIG. 5, and the moving average filter 190 performs the moving average process on the raw load data Wy [n]. Further, based on the so-called processed load data Wy [n] ′ after the moving average processing, the total load Wy [n] currently applied to the load cell 180 is calculated, and eventually the final measured value Ws [n] described later. Is calculated. Note that the number of taps of the moving average filter 188 (the number of raw load data Wy [n] to be averaged), that is, the filter constant C [n] is appropriately changed according to the situation as will be described later.

  Furthermore, the weighing machine 18 also functions as a control means for controlling the valve 20 corresponding to itself. In order to realize this, the weighing machine 18 has a valve control circuit 190 as an interface circuit for connecting the CPU 186 and the valve 20 to each other. The weighing machine 18 includes a communication circuit 192 as an interface circuit with the controller 36 in order to enable mutual communication with the controller 36 as described above. This communication circuit 192 is also connected to the CPU 186. That is, these functions as the control means and the communication function with the controller 36 are realized by the CPU 186 operating according to the control program stored in the memory 194. In addition to this, all the operations of the CPU 186 such as configuring the above-described moving average filter 188 are controlled by the control program. The memory 194 also functions as a second storage unit that stores parameters such as the tare measurement time Tr described above.

  The weight-type filling device 10 having such a configuration realizes quantitative filling by operating as follows. That is, when an operation for starting operation is performed by the operation key 370 of the controller 36, the motor 34 is activated. As a result, the turntable 24 rotates around the rotation shaft 26 in the direction indicated by the arrow 100 in FIG. 2 at a constant rotation speed, for example, at a rate of one rotation every several seconds (about 3 seconds to 5 seconds). As the turntable 26 rotates, the units 14, 14,..., The storage tank 28, and the pipes 30, 30,. Further, in accordance with the activation of the motor 34, the external device described above, specifically, the carry-in conveyor 50, the carry-in star wheel 52, the carry-out star wheel 54, the carry-out conveyor 56 shown in FIG. The machine also starts.

  Then, as shown by an arrow 102 in FIG. 2, empty containers 12, 12,... Are first transported to the loading star wheel 52 by the loading conveyor 50. The carry-in star wheel 52 rotates in the direction indicated by the arrow 104 in FIG. 2 (counterclockwise in FIG. 2), and the containers 12, 12,... One by one is conveyed to the turntable 24. As a result, these containers 12, 12,... Are placed one by one on the placement tables 16, 16,. The containers 12 set in the respective units 14 in this way naturally rotate in the direction indicated by the arrow 100 together with the units 14. During this rotation, each unit 14 fills the container 12 set therein with a beverage.

  Specifically, referring to FIG. 2 and FIG. 6, an arbitrary unit 14 having an identification number “n” (hereinafter referred to as a unit n for convenience of explanation), for example, is an empty container 12. Is set, and at the time t1 when the predetermined tare measurement start position Pr is reached, measurement of the weight of the container 12 itself, that is, the tare weight is started. Thus, whether the unit n has reached the tare measurement start position Pr is recognized based on the position data described above. That is, as described above, the controller 36 (CPU 360) recognizes the current positions of the units 14, 14,... Including the unit n based on the output pulses from the encoders 38 and 40. And based on this recognition result, the position data showing the said present position are produced | generated, and the produced | generated position data are separately transmitted to each unit 14,14, .... Each unit 14 recognizes its current position including whether or not it has reached the tare measurement start position Pr based on this position data (see FIG. 6B).

  The unit n performs the above-described tare measurement from the time point t1 until the predetermined tare measurement time Td elapses. Specifically, the value of the processed load data Wy [n] ′ at the time point t2 when the tare measurement time Td has elapsed is defined as a tare measurement value Wr [n]. That is, the tare measurement value Wr [n] is obtained based on the following equation 1.

  The tare measurement value Wr [n] includes a component of the initial load Wi [n]. The tare measurement value Wr [n] is temporarily stored in the memory 188 in the unit n. The tare measurement time Td is set to be equal to or longer than the natural vibration period Tr of the load cell 180 at least at the time point t2 (or t1), that is, when the empty container 12 is mounted on the mounting table 16. For example, it is set to about 0.1 seconds to 0.3 seconds. This natural vibration period Tr will also be described in detail later.

  Further, the unit n determines whether or not the container 12 is set in itself by comparing the tare measurement value Wr [n] with a predetermined threshold value β. That is, when the tare measurement value Wr [n] is larger than the threshold value β, it is determined that the container 12 is set in itself. On the other hand, when the tare measurement value Wr [n] is equal to or less than the threshold value β, it is determined that the container 12 is not set, and waits for another opportunity to reach the tare measurement start position Pr.

  When it is determined that the tare measurement has been completed and the container 12 has been set, the unit n immediately opens its valve 20. Thereby, the beverage is supplied to the container 12. At this time, the valve 20 is opened with a relatively large diameter, so to speak, it is in a large input state. Then, when the weight of the beverage supplied to the container 12 reaches a predetermined switching weight Wa, specifically, at the time t3 when the following equation 2 is established, the unit n slightly reduces the diameter of the valve 20.

  Thus, by reducing the diameter of the valve 20 a little, the supply amount per unit time of the beverage from the valve 20 to the container 12 is reduced to about 1/2 to 1/3 of the large charging state, In other words, it becomes a small input state. The unit n closes the valve 20 when the weight of the beverage supplied to the container 12 reaches a predetermined supply stop weight Wb, specifically, at the time t4 when the following equation 3 is established.

  Even if the valve 20 is closed, the supply of the beverage to the container 12 is not immediately stopped, and the beverage is continuously supplied to the container 12 for a while. This is mainly due to the fact that there is a distance (drop) between the valve 20 and the container 12 and that there is a time lag between when Formula 3 is established and when the valve 20 is closed. Therefore, until the beverage supply is completely stopped and the vibration of the load cell 180 due to the supply of the beverage being stopped can be regarded as having converged to some extent, in other words, from the time t4 to the predetermined time. Until the stable waiting time Tw elapses, the unit n is in a standby state. The stable waiting time Tw is, for example, about 0.3 to 0.5 seconds, although it depends on the magnitude of the total load Wy [n], the required measurement accuracy, and the like.

  At time t5 when the stabilization waiting time Tw elapses, the unit n starts the final measurement in order to measure the final weight of the beverage supplied to the container 12. This final measurement is performed from the time t5 until a predetermined final measurement time Ts elapses. Specifically, the unit n substitutes the value of the processed load data Wy [n] ′ at the time point t6 when the final measurement time Ts has passed into the following equation 4 to represent the final weight of the beverage. A measurement value Ws [n] is obtained. This final measured value Ws [n] is also temporarily stored in the memory 188.

  It is ideal that the final weighing value Ws [n] is equivalent to a target filling weight of the beverage, so-called target value Wt. The supply stop weight Wb described above is set so as to satisfy such a relationship (Ws [n] ≈Wt). That is, the value (Wt−ΔW [n]) obtained by subtracting the so-called drop amount ΔW [n] from the target value Wt from the weight of the beverage supplied to the container 12 after the valve 20 is closed at the time point t4. The stop weight is Wb. Further, the final measurement time Ts is at least at the natural vibration period Tt of the load cell 180 at the time t6 (or t5), that is, when the container 12 is filled with a beverage having a weight substantially equal to the target value Wt. For example, it is set to about 0.1 seconds to 0.3 seconds. This natural vibration period Tt will also be described in detail later.

  At the time t7 when the unit n reaches the predetermined end position Pe after the end of the final measurement, the above-described final measured value Ws [n] (strictly, the data representing the final measured value Ws [n]) is the unit n. To the controller 36. Thereby, the controller 36 recognizes the final weighing value Ws [n] by the unit n, that is, the weight of the beverage filled in the container 12 by the unit n. Whether or not the unit n has reached the end position Pe is also recognized based on the position data.

  The controller 36 determines whether or not the final measurement value Ws [n] by the unit n satisfies a predetermined standard. Specifically, the final measurement value Ws [n] has a predetermined range “Wt ± γ based on the target value Wt. It is judged whether it is in "." If this standard (Wt−γ ≦ Ws [n] ≦ Wt + γ) is not satisfied, an instruction is given to the above-described sorter so that the containers 12 that do not satisfy the standard are excluded from the production line.

  Note that the unit n cannot obtain the final measurement value Ws [n] until the end position Pe is reached, for example, because the valve 20 is clogged. In other words, the time point t6 is not determined for the unit n. It may not arrive. In such a case, the unit n transmits data “Error” to the controller 36 as the final measured value Ws [n]. Also in this case, the controller 36 gives an instruction to the sorter so that the container 12 that is set to “Error” is excluded from the production line.

  The container 12 that has passed the end position Pe is removed from the unit n (mounting table 16) by the carry-out star wheel 54 as indicated by an arrow 106 in FIG. Thus, a series (one time) of the filling operation by the unit n is completed. And the container 12 removed from the unit n is conveyed by the carrying-out conveyor 56 as shown by the arrow 108, and is sent to the above-mentioned sorter.

  By the way, the load cell 180 of the unit n always emits natural vibration. The natural vibration appears as noise with respect to the measurement signal output from the load cell 180, in other words, the raw load data Wy [n]. Therefore, in order to perform accurate quantitative filling as described above, it is necessary to remove the natural vibration component included in the raw load data Wy [n]. Therefore, the above-mentioned moving average filter 188 is provided to remove this natural vibration component. Since the frequency of the natural vibration, that is, the natural frequency fx [n] varies depending on the load Wy [n] applied to the load cell 180, the filter constant C [n] of the moving average filter 188 as described above. Are appropriately changed. This will be described in detail below.

  That is, the natural frequency fx [n] of the load cell 180 is expressed by the following formula 5.

  Here, k [n] is the spring constant of the load cell 180, and g is the gravitational acceleration. Since the load Wy [n] in the equation 5 includes the initial load Wi [n] in addition to the weight Wx [n] of the object placed on the placement table 16 as described above, 5 can be expressed as the following Equation 6.

  In this equation 6, for example, the following equation 7 is substituted into the weight Wx [n]. Then, the natural frequency fx [n] (hereinafter referred to as the symbol fr [n]) at the time point t2 described above, that is, when the tare measurement value Wr [n] is obtained is obtained.

  Here, Wr [n] ′ is the actual weight of the container 12 itself mounted on the mounting table 16.

  Further, when the following formula 8 is substituted as the weight Wx [n] in the formula 6, for example, the natural frequency fx [n] at the time point t3 described above, that is, the timing at which the beverage supply amount by the valve 20 is switched. (Hereinafter, this is represented by the symbol fa [n]).

  Similarly, by substituting the following equation 9 into the weight Wx [n] in equation 6, the natural frequency fx [at the time point t4 described above, that is, when the supply of the beverage by the valve 20 is stopped is reached. n] (hereinafter referred to as fb [n]).

  When the following equation 10 is substituted into the weight Wx [n] in equation 6, the natural frequency fx [n] (hereinafter referred to as ft) at the time point t6 described above, that is, at the time of obtaining the final measured value Ws [n]. (Represented by the symbol [n]).

  In this equation 10, Ws [n] 'is the actual weight of the beverage filled in the container 12 (present in the container 12 at time t6).

  Then, the natural frequencies fr [n], fa [n], fb [n], and ft [n] at these times t2, t3, t4, and t6 are in the relationship shown in Expression 11.

  Here, for example, it is assumed that the weight Wr [n] ′ of the container 12 itself is substantially uniform and is substantially equivalent to, for example, a standard value Wr determined by a predetermined standard. Further, it is assumed that the weight Ws [n] ′ of the beverage filled in the container 12 is substantially equivalent to the target value Wt. In this case, Equations 7 to 10 can be expressed as Equations 12 to 15, respectively.

  As described above, a natural vibration having a frequency of fr [n], in other words, a period of Tr [n] (= 1 / fr [n]), which is the reciprocal of the frequency, occurs at time points t1 to t2. In order to remove the natural vibration component of the period Tr [n], the raw load data Wy [n] may be averaged over the time equal to or an integral multiple of the period Tr by the moving average filter 188 described above. That is, if the value Cr [n] obtained by the following equation 16 is set as the filter constant C [n] of the moving average filter 188, the natural vibration component of the period Tr [n] is effectively removed. Processed load data Wy [n] ′ is obtained.

  In Equation 16, ε is an integer greater than or equal to 1 (ε ≧ 1), and is, for example, “1” here. Tc is the sampling period of the A / D conversion circuit 184 described above. Then, the decimal number of the value Cr [n] obtained by the equation 16 is rounded off, for example.

  In the memory 194 of the unit n, the value Cr [n] obtained by the equation 16 is stored in advance. Then, before the time point t1 arrives at the unit n, for example, immediately after the previous time point t6 has arrived (the final measured value Ws [n] has been acquired) or immediately after the previous time point t7 has arrived (passed the end position Pe). The value Cr [n] is set as the filter constant C [n]. As a result, the natural vibration component included in the raw load data Wy [n] is effectively removed at time t2, and an accurate tare measurement value Wr [n] is obtained.

  At time t3, a natural vibration having a frequency of fa [n], in other words, a reciprocal of Ta [n] (= 1 / fa [n]) is generated. In order to remove the natural vibration component of the period Ta [n], the raw load data Wy [n] is equivalent to the period Ta or an integral multiple (ε times) of the period Ta by the moving average filter 188 as described above. Should be averaged. That is, if the value Ca [n] obtained by the following equation 17 is set as the filter constant C [n] of the moving average filter 188, the natural vibration component of the period Ta [n] is effectively removed. Processed load data Wy [n] ′ is obtained.

  Therefore, in the memory 194 of the unit n, in addition to the value Cr [n] described above, the value Ca [n] obtained by the equation 17 is stored in advance. Then, before the time point t3 arrives at the unit n, for example, immediately after the time point t2 before the time point 3 has arrived (the tare measurement value Wr [n] is acquired), this value Ca [n] becomes the filter constant C. Set as [n]. As a result, the natural vibration component contained in the raw load data Wy [n] is effectively removed at time t3, and it is accurately grasped that the timing for switching the beverage supply amount by the valve 20 has arrived. Note that the value Ca [n] obtained by Equation 17 is also rounded off after the decimal point.

  Further, at time t4, a natural vibration having a frequency of fb [n], in other words, a period of Tb [n] (= 1 / fb [n]), which is the reciprocal thereof, is generated. Therefore, at this time, if the value Cb [n] obtained by the following equation 18 is set as the filter constant C [n], the natural vibration component of the period Tb [n] is effectively removed. Completed load data Wy [n] ′ is obtained.

  That is, the value Cb [n] obtained by the equation 18 is also stored in advance in the memory 194 of the unit n. Then, before the time point t4 arrives at the unit n, for example, immediately after the time point t3 before the time point t4 has arrived (the supply amount of the beverage by the valve 20 has been switched), this value Cb [n] becomes the filter constant C. Set as [n]. As a result, the natural vibration component included in the raw load data Wy [n] is effectively removed at the time t4, and it is accurately captured that the timing for closing the valve 20 has arrived. The value Cb [n] obtained by the equation 18 is also rounded off after the decimal point.

  Then, from time t5 to t6, a natural vibration having a frequency of ft [n], in other words, a period of Tt [n] (= 1 / ft [n]), which is the reciprocal thereof, occurs. Accordingly, at this time, if the value Ct [n] obtained by the following equation 19 is set as the filter constant C [n], the natural vibration component of the period Tt [n] is effectively removed. Used load data Wy [n] ′ can be obtained.

  For this reason, the value Ct [n] obtained by the equation 19 is also stored in advance in the memory 194 of the unit n. The value Ct [n] is set as the filter constant C [n] before the time point t5 arrives at the unit n, for example, immediately after the time point t4 before the time point t5 arrives (the valve 20 is closed). Is done. As a result, the natural vibration component included in the raw load data Wy [n] is effectively removed at time points t5 to t6, and an accurate final measurement value Ws [n] is obtained. Note that the value Ct [n] obtained by Equation 19 is also rounded off after the decimal point.

  FIG. 7 conceptually shows the configuration of the moving average filter 188. As shown in FIG. 7, the moving average filter 188 has a plurality of, for example, Q registers 200, 200,. The raw load data Wy [n] converted by the A / D conversion circuit 184 is first input to the first register 200 (at the left end in FIG. 7). The raw load data Wy [n] input to the register 200 is rewritten every time new raw load data Wy [n] is input from the A / D conversion circuit 184, in other words, the A / D conversion circuit. In accordance with the sampling timing of 184, the data is sequentially moved (shifted) to the register 200 on the right side. The raw load data Wy [n] moved to the last (Qth register at the right end in FIG. 7) register 200 is discarded at the next sampling timing by the A / D conversion circuit 184.

  Here, for example, when the value Cr [n] obtained by the above equation 16 is set as the filter constant C [n], it is stored in the first to Cr [n] -th registers 200, 200,. An average value Wyr [n] of the raw load data Wy [n] is obtained. The average value Wyr [n] is output as processed load data Wy [n] ′. On the other hand, when the value Ca [n] obtained by Expression 17 is set as the filter constant C [n], the raw load data stored in the first to Ca [n] -th registers 200, 200,. An average value Wya [n] of Wy [n] is obtained, and this average value Wya [n] is output as processed load data Wy [n] ′. Further, when the value Cb [n] obtained by Expression 18 is set as the filter constant C [n], the raw load data stored in the first to Cb [n] -th registers 200, 200,. An average value Wyb [n] of Wy [n] is output as processed load data Wy [n] ′. When the value Ct [n] obtained by Equation 19 is set as the filter constant C [n], the raw load data stored in the first to Ct [n] -th registers 200, 200,. An average value Wyt [n] of Wy [n] is output as processed load data Wy [n] ′. Note that the number Q of the registers 200 is at least the maximum value (Ct [n]) that can be set as the filter constant C [n].

  Thus, the values Cr [n], Ca [n], Cb [n] and Ct [n] set as the filter constant C [n] are obtained by the adjustment mode.

  That is, in the adjustment mode, first, for each unit 14, the natural frequency fz [n] when there is no load, strictly, when no object is placed on the mounting table 16. Is required. Specifically, for each unit 14, a predetermined impact is applied, for example, by an impulse hammer (not shown) in a state where no object is placed on the mounting table 16. At this time, the raw load data Wy [n] of the unit 14 to which the impact is applied is input to the digital recorder 44 via the controller 36 and is recorded by the digital recorder 44 over a certain period of time. Then, the natural frequency fz [n] is read by the operator from the raw load data Wy recorded in the digital recorder 44, and the read natural frequency fz [n] is written down in, for example, a note. The natural frequency fz [n] at the time of no load is, for example, about 50 Hz to 200 Hz, although it depends on the size of the unit 14.

  Next, for each unit 14, the natural frequency fm [n] when the existing test load Wm is placed on the placement table 16 is obtained. Specifically, a predetermined impact is applied to each unit 14 by the above-described impulse hammer while the test load Wm is placed. Then, the raw load data Wy [n] of the unit 14 to which this impact is applied is recorded in the digital recorder 44 over a certain period of time as described above. The natural frequency fm [n] is read from the raw load data Wy [n] recorded in the digital recorder 44, and the read natural frequency fm [n] is written down in a note. The natural frequency fm [n] is smaller than the natural frequency fz [n] at no load.

  In this way, after the natural frequencies fz [n] and fm [n] are obtained for all the units 14, 14,..., These natural frequencies fz [n] and fm [n] Input from 36 operation keys 370 (by the operator). The input natural frequencies fz [n] and fm [n] (strictly, these data) are stored in the memory 374 in the controller 36 and then transmitted to the corresponding units 14 (the weighing machines 18). The

  Following this, by further operation of the operation key 370, the above-described parameters, specifically, the tare measurement time Td, the stabilization waiting time Tw, the final measurement time Ts, the standard weight Wr of the container 12, the switching weight Wa, and the supply stop weight Wb. And the target value Wt is input. These parameters are also stored in the memory 374 in the controller 36, and then transmitted to the units 14, 14,.

  On the other hand, in each unit 14, the natural frequencies fz [n], fm [n] and parameters transmitted from the controller 36 are stored in the memory 194. Then, based on these natural frequencies fz [n] and fm [n] and each parameter, strictly, the standard weight Wr, switching weight Wa, supply stop weight Wb, and target value Wt of the container 12, Values Cr [n], Ca [n], Cb [n] and Ct [n] are determined.

  That is, the natural frequencies fz [n] and fm [n] described above are expressed by Equations 20 and 21, respectively.

  Then, the equations for obtaining the spring constant k [n] and the initial load Wi [n] are derived as shown in the following equations 22 and 23 by the simultaneous equations consisting of these equations 20 and 21.

  The spring constant k [n] and the initial load Wi [n] obtained by the equations 22 and 23 are substituted into the above equation 6, and each of the above equations 12 to 15 is substituted into the equation 6. When substituted, the natural frequencies fr [n], fa [n], fb [n], and ft [n] at the time points t1 to t2, t3, t4, and t5 to t6, and the natural vibration periods Tr [n], Ta [N], Tb [n] and Tt [n] can be obtained. Then, by substituting these natural vibration periods Tr [n], Ta [n], Tb [n], and Tt [n] into Equations 16 to 19, respectively, the above-described values Cr [n], Ca [N], Cb [n] and Ct [n] can be calculated. The calculated values Cr [n], Ca [n], Cb [n], and Ct [n] are stored in the memory 194.

  After the values Cr [n], Ca [n], Cb [n], and Ct [n] are obtained in the adjustment mode as described above, the filling operation is performed in the above-described manner according to the operation mode. In the filling operation in the operation mode, the tare measurement from the time point t1 to the time point t2 is performed based on the tare measurement time Td, the stabilization waiting time Tw, and the final measurement time Ts as parameters stored in the memory 194 in the adjustment mode. A stabilization wait from time t4 to time t5 and a final measurement from time t5 to time t6 are performed. Then, based on the switching weight Wa and the supply stop weight Wb stored as parameters in the memory 194, a time t3 that is a beverage supply amount switching timing and a time t4 that is a supply stop timing are determined.

  In order to realize a series of operations in each of the adjustment mode and the operation mode, the CPU 360 of the controller 36 and the CPU 186 of each unit 14 (the weighing machine 18) perform multitask processing as follows. Note that, during this process, for example, when an interrupt operation for forcible termination is performed by the operation key 370, the process being executed is forcibly terminated. In the adjustment mode, it is assumed that the digital recorder 44 is connected to the data output terminal 42 of the controller 42 in advance. It is assumed that so-called zero point adjustment and temperature drift adjustment are performed in advance for each of the units 14, 14,.

  First, when the adjustment mode is selected by operating the operation key 370, the CPU 360 of the controller 36 executes the adjustment mode task shown in FIGS. That is, in step S101 in FIG. 8, the units 14, 14,... Are notified that the adjustment mode has been selected. In step S103, in order to validate the unit 14 with the identification number "1" among the units 14, 14, ..., a value "1" is set in the index n for specifying the identification number. . In step S105, the raw load data Wy [n] are sequentially acquired from the activated unit 14 (hereinafter, this activated unit 14 is also expressed as unit n), and the obtained raw data is obtained. The load data Wy [n] is sequentially transferred to the data output circuit 362. Thus, the raw load data Wy [n] is input to the digital recorder 44. In step S107, the CPU 360 displays a message on the display 372 requesting that the unit n be measured for the natural frequency fz [n] at no load.

  After displaying this message, the CPU 360 proceeds to step S109 and waits for the measurement of the natural frequency fz [n] for the unit n to end. That is, during this period, an impact is applied to the unit n by the impulse hammer as described above in a state where no object is placed on the mounting table 16 of the unit n. The raw load data Wy [n] of the unit n at this time is recorded in the digital recorder 44, and the natural frequency fz [n] of the unit n is read by the operator from the recorded raw load data Wy [n]. It is done. The read natural frequency fz [n] is written down in a note by the operator.

  After the natural frequency fz [n] of the unit n is obtained in this way (written in a note), an operation to the effect that the measurement of the natural frequency fz [n] of the unit n is completed by the operation key 370. When the process is completed, the CPU 360 proceeds from step S109 to step S111. In step S111, it is determined whether or not the value of the index n described above is equal to the maximum value “N”. Here, when the value of the index n is not equal to the maximum value “N”, that is, when there is a unit 14 for which the measurement of the natural frequency fz [n] has not been completed, the natural frequency of the unit 14 is determined. In order to measure fz [n], the value of index n is incremented by “1” in step S113, and then the process returns to step S105. On the other hand, when the value of the index n is equal to the maximum value “N”, that is, when the measurement of the natural frequency fz [n] is completed for all the units 14, 14,..., The process proceeds from step S 111 to step S 115.

  In step S115, the CPU 360 sets a value “1” to the index n in order to validate the unit 14 with the identification number “1” again. In step S117, the raw load data Wy [n] is sequentially acquired from the validated unit n, and the acquired raw load data Wy [n] is sequentially transferred to the data output circuit 362. In step S119, a message requesting that measurement of the natural frequency fm [n] with the test load Wm applied to the unit n is requested is displayed on the display 372. Then, the process proceeds to step S121, and waits for the measurement of the natural frequency fm [n] for the unit n to end.

  During this time, an impact is applied to the unit n by the impulse hammer while the test load Wm is placed on the placing table 16 of the unit n. The raw load data Wy [n] of the unit n at this time is recorded in the digital recorder 44, and the natural frequency fm [n] of the unit n is read from the recorded raw load data Wy [n]. Then, the read natural frequency fz [n] is written down in a note.

  After the natural frequency fz [n] of the unit n is obtained in this way, when the operation indicating that the measurement of the natural frequency fm [n] of the unit n is completed is performed by the operation key 370, the CPU 360 is performed. Advances from step S121 to step S123. In step S123, it is determined whether or not the value of the index n is equal to the maximum value “N”. Here, when the value of the index n is not equal to the maximum value “N”, that is, when there is a unit 14 for which the measurement of the natural frequency fm [n] has not been completed, the natural frequency of the unit 14 is determined. In order to measure fm [n], the value of the index n is incremented by “1” in step S125, and the process returns to step S117. On the other hand, when the value of the index n is equal to the maximum value “N”, that is, when the measurement of the natural frequency fm [n] is completed for all the units 14, 14,. move on.

  In step S127, the CPU 360 sets a value of “1” to the index n in order to re-enable the unit 14 having the identification number “1”. In step S129, the display 372 displays a message requesting input of the natural frequency fz [n] of the activated unit n when there is no load. Then, the process proceeds to step S131 and waits for the natural frequency fz [n] to be input.

  In step S131, when the natural frequency fz [n] of the unit n is input from the operation key 370, the CPU 360 proceeds to step S133. In step S133, the input natural frequency fz [n] (strictly, data representing the natural frequency fz [n]) is stored in the memory 374. In step S135, the natural vibration fz [n] is stored. The number fz [n] is transmitted to unit n. Then, the process proceeds to step S137.

  In step S137, the CPU 360 displays on the display 372 a message requesting input of the natural frequency fm [n] when the test load Wm is applied to the unit n. Then, the process proceeds to step S139 to wait for the natural frequency fm [n] to be input.

  Here, when the natural frequency fm [n] of the unit n is input by operating the operation key 370, the CPU 360 proceeds to step S141. In step S141, the input natural frequency fm [n] is stored in the memory 374. In step S143, the natural frequency fm [n] is transmitted to the unit n, and then in step S145. move on.

  In step S145, the CPU 360 determines whether or not the value of the current index n is equal to the maximum value “N”. Here, when the value of the index n is not equal to the maximum value “N”, that is, when there is a unit 14 for which the input of the natural frequencies fz [n] and fm [n] by the operation key 370 has not been finished yet. In step S147, the value of the index n is incremented by “1” to request the unit 14 to input the natural frequencies fz [n] and fm [n], and then the process returns to step S129. On the other hand, when the value of the index n is equal to the maximum value “N”, that is, when the input of the natural frequencies fz [n] and fm [n] is completed for all the units 14, 14,. The process proceeds to S149.

  In step S149, the CPU 360 displays a message on the display 372 requesting input of the parameters (Td, Tw, Ts, Wr, Wa, Wb, and Wt) described above. Then, the process proceeds to step S151 and waits for the input of the parameter. Here, when any parameter is input from the operation key 370, the CPU 360 proceeds to step S 153 and stores the input parameter in the memory 374. In step S155, it is determined whether all parameters have been input. If all parameters have not yet been input, the process returns to step S151. On the other hand, if all parameters have been input, the process proceeds from step S155 to step S157 in FIG.

  In step S157, the CPU 360 transmits the parameters stored in the memory 374 to all the units 14, 14,. In step S159, it is currently in the final setting stage of the adjustment mode. Specifically, in each unit 14, the above-described values Cr [n], Ca [n], Cb [n], and Ct [n] are set. A message indicating that it is being requested is displayed on the display 372. In step S161, a value of “1” is set to the index n described above, and the process proceeds to step S163.

  In step S163, the CPU 360 obtains the current situation, specifically the values Cr [n], Ca [n], Cb [n], and Ct [n] for the unit n specified by the index n described above. Inquire whether or not. In step S165, the system waits for a response from the unit n to the inquiry.

  When a response is returned from the unit n, that is, when it is recognized that the respective values Cr [n], Ca [n], Cb [n] and Ct [n] have been obtained in the unit n, the CPU 360 proceeds to step S165. To step S167. In step S167, it is determined whether or not the current index n value is equal to the maximum value “N”. Here, if the value of the index n is not equal to the maximum value “N”, that is, if there is a unit 14 that has not yet inquired about the situation, in step S169, the index n is inquired about the situation. After incrementing the value by “1”, the process returns to step S163. On the other hand, when the value of the index n is equal to the maximum value “N”, that is, when inquiries are made to all the units 14, 14,..., The process proceeds from step S167 to step S171.

  In step S171, CPU 360 displays a message indicating that a series of settings in the adjustment mode has ended on display 372 over a certain period of time. Then, the adjustment mode task is completed with the elapse of the predetermined time.

  For the operation of the CPU 36 on the controller 36 side, the CPU 186 on each unit 14 (unit n) side executes the pair adjustment mode task shown in FIG. 11 in the adjustment mode.

  That is, upon receiving a notification that the adjustment mode has been selected from the controller 36, the CPU 186 proceeds to step S201, and the raw load data Wy [n] input from the A / D conversion circuit 184 is left as it is. Transfer to the communication circuit 192. Thus, the raw load data Wy [n] is transmitted to the controller 36 via the communication circuit 192.

  In step S203, the CPU 186 waits for the natural frequency fz [n] (specifically, data representing the natural frequency fz [n]) to be sent from the controller 30 when no load is applied. When the natural frequency fz [n] is received, the process proceeds to step S205, and the natural frequency fz [n] is stored in the memory 194. In step S207, the controller 30 waits for the natural frequency fm [n] when the test load Wm is applied to be sent from the controller 30.

  In step S207, upon receiving the natural frequency fm [n] from the controller 30, the CPU 186 proceeds to step S209, and stores the received natural frequency fm [n] in the memory 194. In step S211, the spring constant k [n] and the initial load Wi [n] are calculated based on these natural frequencies fz [n] and fm [n], that is, based on the above-described equations 22 and 23. calculate.

  After executing step S211, the CPU 186 proceeds to step S213 and waits for the above-described parameters (Td, Tw, Ts, Wr, Wa, Wb, and Wt) to be sent from the controller 30. When these parameters are received, the process proceeds to step S215, and the received parameters are stored in the memory 194. In step S217, these parameters, strictly speaking, the standard weight Wr, switching weight Wa, supply stop weight Wb and target value Wt of the container 12, and the above-described natural frequencies fz [n] and fm [n] are obtained. Then, the respective values Cr [n], Ca [n], Cb [n] and Ct [n] are calculated in the manner described above (based on Equations 12 to 23). These calculation results Cr [n], Ca [n], Cb [n], and Ct [n] are stored in the memory 194.

  After executing step S217, the CPU 186 proceeds to step S219 and waits for a status inquiry from the controller 30. When this inquiry is accepted, the process proceeds to step S221, and a response to the inquiry is returned. In step S223, the output of the raw load data Wy [n] is stopped, and the series of pair adjustment mode tasks are ended.

  On the other hand, in the operation mode, the CPU 360 on the controller 36 side executes the operation mode task shown in FIG. In this operation mode, it is assumed that the digital recorder 44 is removed from the data output terminal 42 of the controller 36.

  That is, when the operation mode is selected by operating the operation key 370, the CPU 360 proceeds to step S301 and notifies all the units 14, 14,... That the adjustment mode has been selected. In step S303, it is determined whether or not an operation start operation has been performed with the operation key 370, that is, whether or not an operation start command has been input from the operation key 370.

  When this operation start command is input, the CPU 360 proceeds from step S303 to step S305, starts the motor 34, and instructs the external device such as the carry-in conveyor 50 to start. In step S307, all units 14, 14,... In step S309, the execution of the timing control task is started. This timing control task will be described in detail later.

  In step S311, the CPU 360 continues until an empty container 12 is set in each unit 14, 14,..., For example, until a certain time elapses when it can be sufficiently considered that the container 12 is set. It will be in a standby state. And after progress of this fixed time, it progresses to step S313 and starts performing a data acquisition task. Thereby, the filling operation by each unit 14 is repeatedly performed in the manner described above. The data acquisition task will be described in detail later.

  While the filling operation is performed in this way, in step S315, the CPU 360 determines whether or not an operation stop operation has been performed by the operation key 370, that is, whether or not an operation stop command has been input from the operation key 370. Judging. Here, when the operation stop command is input, the process proceeds to step S317, the above-described timing control task is terminated, and further, the data acquisition task is terminated in step S319. In step S321, all units 14, 14,... Are instructed to stop operation, and in step S323, the motor 34 is stopped and the external device is instructed to stop driving. With the end of step S323, a series of operation mode tasks are ended.

  Details of the timing control task described above will be described with reference to FIG. In this timing control task, the CPU 360 first acquires the output pulses of the encoders 38 and 40 in step S401. In step S403, “1” is set to the index n described above, and then the process proceeds to step S405.

  In step S405, the CPU 360 determines whether the unit n has reached the tare measurement start position Pr based on the output pulses of the encoders 38 and 40 acquired in step S401. Here, when the unit n has reached the tare measurement start position Pr, in step S407, the fact is notified to the unit n by the position data described above, and the process proceeds to step S409. On the other hand, if the unit n has not reached the tare measurement start position Pr, the process skips step S407 and proceeds directly to step S409.

  In step S409, the CPU 360 determines whether the unit n has reached the end measurement start position Pe based on the output pulses of the encoders 38 and 40 acquired in step S401. Here, when the unit n has reached the end measurement start position Pe, in step S411, the fact is notified to the unit n by position data, and the process proceeds to step S413. If the unit n has not reached the end measurement start position Pe, the process skips step S411 and proceeds directly to step S413.

  In step S413, the CPU 360 determines whether or not the value of the index n is equal to the maximum value “N”. Here, when the value of the index n is not equal to the maximum value “N”, that is, when all the units 14, 14,... In order to execute step S405 to step S411, in step S415, the value of index n is incremented by “1”, and then the process returns to step S405. On the other hand, when the value of the index n is equal to the maximum value “N”, that is, when the steps S405 to S411 are completed for all the units 14, 14,..., All the units 14, 14,. The process returns to step S401 to execute steps S405 to S411.

  Next, details of the data acquisition task will be described with reference to FIG. In this data acquisition task, the CPU 360 first sets “1” to the index n in step S501. In step S503, it is determined whether the unit n has reached the end position Pe. If the unit n has reached the end position Pe, the process proceeds to step S505.

  In step S505, the CPU 360 requests the unit n to obtain the final measurement value Ws [n]. In step S507, it is determined whether or not the final measurement value Ws [n] is sent from the unit n. If it is sent, the process proceeds to step S509.

  In step S509, the CPU 360 determines whether or not the final measurement value Ws [n] received from the unit n is “Error”. Here, if it is not “Error”, the process further proceeds to step S511, and it is determined whether or not the final measured value Ws [n] satisfies the above-mentioned standard (Wt−γ ≦ Ws [n] ≦ Wt + γ). If this standard is satisfied, the process proceeds to step S513.

  On the other hand, if the final measurement value Ws [n] is “Error” in step S509, the CPU 360 proceeds to step S515. In step S515, an instruction is given to the above sorter so that the unit n is excluded from the production line, and then the process proceeds to step S513. Similarly, when the final measurement value Ws [n] does not satisfy the above-described standard in step S511, the process proceeds to step S513 via step S515.

  In step S513, the CPU 360 determines whether the value of the index n is equal to the maximum value “N”. Here, when the value of the index n is not equal to the maximum value “N”, that is, when the final measured values Ws [n] of all the units 14, 14,. After incrementing the value of n by “1”, the process returns to step S503. On the other hand, when the value of the index n is equal to the maximum value “N”, that is, when the final measured values Ws [n] of all the units 14, 14,. In order to obtain the final measured value Ws [n] from the number unit 14, the process returns to step S501.

  On the other hand, the CPU 186 of each unit 14 is in the operation mode. It operates as follows.

  In other words, upon receiving notification from the controller 36 that the operation mode has been selected, the CPU 186 executes the anti-operation mode task shown in FIG. In this anti-operation mode, first, in step S601, the controller 36 waits for an operation start instruction sent from the controller 36. When this operation start instruction is received, the process proceeds to step S603 to start executing a weighing task described later.

  Then, the CPU 186 proceeds to step S605, and determines whether or not an acquisition request for the final measurement value Ws [n] has been received from the controller 36. If the acquisition request is accepted, the process proceeds to step S607, and the final measured value Ws [n] is transmitted to the controller 36. After this transmission, the process returns to step S605. On the other hand, if an acquisition request for the final measurement value Ws [n] is not accepted in step S605, the process proceeds to step S609, and it is determined whether an operation stop instruction is accepted from the controller 36. And when this operation stop instruction is not received, it returns to Step S605.

  When accepting the operation stop instruction in step S609, the CPU 186 proceeds to step S611 and ends the execution of the weighing task started in step S603 described above. Then, upon completion of the weighing task, a series of anti-operation mode tasks are terminated.

  The weighing task will be described in detail with reference to FIGS. 16 and 17. In this weighing task, the CPU 186 first proceeds to step S701 in FIG. 16, and sets a value Cr [n] as the filter coefficient C [n] of the moving average filter 188 described above. Accordingly, the moving average filter 188 outputs the above-described average value Wyr [n] in FIG. 7 as processed load data Wy [n] ′.

  Then, the CPU 186 proceeds to step S703 to determine whether or not itself (strictly, the unit 14 having the CPU 186) has reached the tare measurement start position Pr. This determination is made based on the above-described position data sent from the controller 36. When it is determined that the tare measurement start position Pr has been reached, the process proceeds to step S705, where a timer for measuring the tare measurement time Td is reset and immediately started. In step S707, it is determined whether or not the tare measurement time Td has elapsed.

  When the tare measurement time Td has elapsed, the CPU 186 proceeds from step S707 to step S709, and obtains a tare measurement value Wr [n]. That is, according to the above equation 1, the value of the processed load data Wy [n] ′ at the time point t2 when the tare measurement time Td has elapsed is set as the tare measurement value Wr [n]. This tare measurement value Wr [n] is temporarily stored in the memory 194.

  Then, the CPU 18 proceeds to step S711, and determines whether or not the empty container 12 is correctly set in itself (unit 14) based on the tare measurement value Wr [n]. That is, as described above, the tare measurement value Wr [n] is compared with the predetermined threshold value β. If the tare measurement value Wr [n] is equal to or less than the threshold value β, it is determined that the container 12 is not set correctly, and the process returns to step S703. On the other hand, if the tare measurement value Wr [n] is larger than the threshold value β, it is determined that the container 12 is set correctly, and the process proceeds to step S713.

  In step S713, the CPU 186 controls the valve 20 so that the supply of the beverage to the container 12 is started. As a result, the valve 20 enters a large input state. Then, the CPU 186 proceeds to step S715, and sets the value Ca [n] as the filter coefficient C [n] of the moving average filter 188. Thereby, the moving average filter 188 outputs the average value Wya [n] in FIG. 7 as processed load data Wy [n] ′.

  After execution of step S715, the CPU 186 proceeds to step S717 in FIG. 17 and determines whether or not the weight of the beverage supplied to the container 12 has reached the switching weight Wa. That is, it is determined whether or not the above equation 2 is established. Here, when the weight of the supplied beverage has not yet reached the switching weight Wa, the process proceeds to step S719, and it is determined whether or not the beverage has reached the end position Pe. This determination is also made based on the position data described above. If the end position Pe has not yet been reached, the process returns from step S719 to step S717.

  On the other hand, when the weight of the beverage already supplied reaches the switching weight Wa in step S717, in other words, when the time point t3 comes, the CPU 186 proceeds to step S721 and slightly reduces the aperture of the valve 20. As a result, the valve 20 transitions from the large input state to the small input state. Further, in step S723, the CPU 186 sets a value Cb [n] as the filter constant C [n]. Accordingly, the moving average filter 188 outputs the average value Wyb [n] in FIG. 7 as processed load data Wy [n] ′.

  Then, the CPU 186 proceeds to step S725 to determine whether or not the weight of the supplied beverage has reached the supply stop weight Wb [n]. That is, it is determined whether or not the above equation 3 is established. Here, if the weight of the supplied beverage has not yet reached the supply stop weight Wb [n], the process further proceeds to step S727 to determine whether or not the beverage has reached the end position Pe. If the end position Pe has not yet been reached, the process returns from step S727 to step S725.

  On the other hand, when the weight of the beverage already supplied reaches the supply stop weight Wb [n] in step S725, in other words, when the time point t4 comes, the CPU 186 proceeds to step S729 and closes the valve 20. In step S731, the timer for measuring the stable waiting time Tw is reset and immediately started. In step S733, the value Ct [n] is set as the filter constant C [n]. Accordingly, the moving average filter 188 outputs the average value Wyt [n] in FIG. 7 as processed load data Wy [n] ′.

  After execution of step S733, the CPU 186 proceeds to step S735 and determines whether or not the stabilization waiting time Tw has elapsed. If the stabilization waiting time Tw has not yet elapsed, the process further proceeds to step S737, where it is determined whether or not it has reached the end position Pe. If the end position Pe has not been reached, the process returns to step S735.

  When the stable waiting time Tw elapses in step S735, in other words, when the time point t5 arrives, the CPU 186 proceeds to step S739, resets a timer for measuring the final measurement time Ts, and starts immediately. In step S741, it is determined whether or not the final measurement time Ts has elapsed. If it has not elapsed, it is further determined in step S743 whether or not it has reached the end position Pe. If the end position Pe has not been reached, the process returns to step S741.

  When the final measurement time Ts has elapsed in step S741, the CPU 186 proceeds to step S745 and calculates the final measurement value Ws [n]. Specifically, the final measured value Ws [n] is obtained by substituting the processed load data Wy [n] ′ at the time point t6 when the final measurement time Ts has passed into the above-described equation 4. In step S745, the final measured value Ws [n] is stored in the memory 192. Thereby, one filling operation is completed. Then, after executing step S745, the process returns to step S701 in FIG. 16 to repeat the filling operation.

  When the end position Pe is reached in step S743, that is, when the final waiting time Tw has elapsed but the final weighing value Ws [n] has not been obtained, the CPU 186 proceeds to step S747 and proceeds to step S747. The above-described data “Error” is set as Ws [n]. And after execution of this step S747, it returns to step S701 of FIG. Similarly, when the end position Pe is reached in step S737, that is, when the final weighing value Ws [n] is not obtained although the filling of the beverage into the container 12 is completed, the process goes through step S747 in the same manner as in FIG. The process returns to step S701.

  Further, when the end position Pe is reached in step S727 described above, that is, when the end position Pe is reached in the small injection state, the CPU 186 closes the valve 20 in step S749. Then, after step S747, the process returns to step S701 in FIG. Also, when the end position Pe is reached in step S719, that is, when the end position Pe is reached in the large input state, the process returns to step S701 in FIG. 16 through step S749 and step S747.

  As described above, according to this embodiment, when the tare measurement value Wr [n] is obtained at the time t2, when determining the time t3 that is the switching timing of the beverage supply amount by the valve 20, and by the valve 20 The raw load data Wy is used as the filter constant C [n] of the moving average filter 188 when determining the time point t4 that is the beverage supply stop timing, and further when obtaining the final measured value Ws [n] at the time point t6. Values Cr [n], Ca [n], Cb [n] and Ct [n] suitable for removing the natural vibration component included in [n] are set. Therefore, the tare measurement value Wr [n], the beverage supply amount switching timing, the beverage supply stop timing, and the final measurement value Ws [n] can be accurately captured. Therefore, more accurate quantitative filling can be realized as compared with the above-described conventional technique in which the tare weight cannot be accurately captured.

  Further, the natural frequency fz [n] of each unit 14 when there is no load and the natural frequency fm [n] when the test load Wm is applied are measured, and these measured results fz [n] and Based on fm [n], the spring constant k [n] and the initial load Wi [n] are obtained. Therefore, for example, compared with the case where the respective estimated values are applied as the spring constant k [n] and the initial load Wi [n], the natural frequencies fr [n at the respective times t2, t3, t4, and t6 described above. ], Fa [n], fb [n] and ft [n] can be determined accurately, and thus more accurate values Cr [n], Ca [n], Cb [n] as the filter constant C [n]. ] And Ct [n] can be determined.

  In this embodiment, the so-called rotary weight type filling device 10 in which the filling operation is performed while the units 14, 14,. For example, the present invention is applied to a so-called parallel (line) type intensive filling device in which a plurality of units are arranged in a row and filling operations are performed in parallel (so as to badge processing) by these units. You may apply.

  In addition, although the number N of the units 14, 14,... Is “36”, other numbers may be used. In addition, the present invention is applied not only to the so-called multiple-type heavy-weight filling device 10 having a plurality of units 14, 14,... But also to a so-called single-type filling device having only one unit. May be.

  And the to-be-measured object is not limited to beverages, but may be other liquids such as alcohol and oil. Moreover, this invention is applicable not only to a liquid but to the apparatus which fills solids, such as a granular material, as a to-be-measured object.

  Further, each of the flowcharts shown in FIGS. 8 to 17 described above is merely an example, and is not limited to this as long as the same operations and effects as those described in this embodiment can be obtained. For example, in this embodiment, the above-described values Cr [n], Ca [n], Cb [n] and Ct [n] are obtained in each unit 14 (the weighing machine 18). You may make it ask | require collectively by.

  Further, although the moving average filter 188 is employed as the filter means, other filters such as an FIR (Finite-duration Impulse Response) filter may be employed.

  The digital recorder 44 is used to obtain the natural frequency fz [n] when no load is applied to each unit 14 and the natural frequency fm [n] when the test load Wm is applied. Not exclusively. For example, by analyzing the raw load data Wy [n] of each unit 14 in the frequency domain using a spectrum analyzer (FFT (Fast Fourier Transform) processing), the natural frequencies fz [n] and fm [n ] May be obtained. Further, a function of automatically obtaining these natural frequencies fz [n] and fm [n] may be provided in the controller 36 or each unit 14. Further, in place of the natural frequency fz [n] at no load, a natural frequency fm [n] ′ when a test load Wm ′ (≠ Wm) different from the test load Wm is applied is obtained, Even if the spring constant k [n] and the initial load Wi [n] are obtained based on the natural frequency fm [n] ′ and the natural frequency fm [n] ′ when the test load Wm is applied. Good.

  A plurality of switching timings such as the time point t3 described above may be provided. That is, the present invention can be applied even when the beverage supply amount is switched in a plurality of stages. Further, the present invention can also be applied to a so-called different kind of filling device in which a plurality of types of objects to be weighed are filled with a predetermined weight.

  Furthermore, instead of the standard weight Wr of the container 12 in the above-described formulas 12 to 15, an actual measurement value of the weight of the container 12 may be used. In this way, the natural frequencies fr [n], fa [n], fb [n], and ft [n] at each time point t2, t3, t4, and t6, and thus each value as the filter constant D [n]. Cr [n], Ca [n], Cb [n] and Ct [n] can be obtained more accurately.

It is a schematic block diagram of one Embodiment of this invention. It is an illustration figure for demonstrating the operation | movement of the embodiment. It is a block diagram which shows the structure of the controller in the same embodiment. It is a block diagram which shows the structure of each unit in the embodiment. It is an illustration figure which shows notionally the moving average filter comprised by CPU of each unit side in the embodiment. It is an illustration figure for demonstrating operation | movement of each unit in the embodiment. It is an illustration figure which shows notionally the detailed structure of the moving average filter of FIG. It is a flowchart which shows the content of the adjustment mode task which CPU of the controller side in the embodiment performs. It is a flowchart following FIG. It is a flowchart following FIG. It is a flowchart which shows the content of the pair adjustment mode task which CPU of each unit side in the embodiment performs. It is a flowchart which shows the content of the operation mode task which CPU of the controller side in the embodiment performs. It is a flowchart which shows the content of the timing control task which CPU of the controller side in the embodiment performs. It is a flowchart which shows the content of the data acquisition task which CPU of the controller side in the embodiment performs. It is a flowchart which shows the content of the operation mode task which CPU of each unit side in the embodiment performs. It is a flowchart which shows the content of the measurement task which CPU of each unit side in the embodiment performs. It is a flowchart following FIG.

Explanation of symbols

10 Weight Filling Device 14 Unit 18 Weighing Machine 20 Valve 36 Controller 44 Digital Recorder

Claims (4)

A tare is placed on the tare, and the tare is supplied to the tare placed on the weighing means to a predetermined target weight; In the gravimetric filling device removed from the weighing means,
Filter means for applying a filtering process according to the selected filter constant to the weighing signal output from the weighing means;
First setting means in which a first constant determined based on an initial load of the weighing means, a spring constant of the weighing means, and a standard weight of the tare is set;
A second setting means in which at least one second constant determined based on the initial load, the spring constant, the standard weight, and at least one reference weight is set;
When the tare is placed on the weighing means and the object to be weighed is not supplied to the tare, the first constant is selected as the filter constant, and the tare is placed on the weighing means. And the second constant corresponding to the reference weight is selected as the filter constant when the weight of the object to be weighed supplied to the tare is substantially equal to one of the reference weights. A selection means for selecting a filter constant;
The weighing when a known second weight different from the natural frequency of the weighing means when the known first weight is applied to the object mounting portion of the weighing means is applied. Determining means for determining the initial load and the spring constant based on the natural frequency of the means, and determining the first constant and the second constant based on an arithmetic expression including the initial load and the spring constant;
A weight-type filling device comprising:   The gravimetric filling device according to claim 1, wherein the reference weight includes the target weight. Switching means for switching the supply amount of the object to be weighed to the tare per unit time;
The weight-type filling device according to claim 1 or 2, wherein the reference weight includes at least one switching weight that becomes a reference when the supply amount is switched. In the gravimetric filling method in which the tare is removed from the weighing means together with the supplied weighing object after the weighing object is supplied to the tare placed on the weighing means so as to have a predetermined target weight.
A filtering process for applying a filtering process in accordance with the selected filter constant to the weighing signal output from the weighing means;
Based on an initial load of the weighing means, a spring constant of the weighing means, and a standard weight of the tare, based on a first constant, the initial load, the spring constant, the standard weight, and at least one reference weight. A selection step of selecting any one of at least one second constant defined as the filter constant;
Comprising
In the selection process, the first constant is selected as the filter constant when the tare is placed on the weighing means and the object to be weighed is not supplied to the tare. Is placed and the weight of the object to be weighed supplied to the tare is substantially equal to one of the reference weights, the second constant corresponding to the reference weight is selected as the filter constant,
Furthermore, when a known second weight different from the natural frequency of the weighing means when the known first weight is applied to the object mounting portion of the weighing means and the first weight is applied. Determining the initial load and the spring constant based on the natural frequency of the measuring means, and determining the first constant and the second constant based on an arithmetic expression including the initial load and the spring constant; To have,
A gravimetric filling method.

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