JP2006300703A - Combination weighing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combination weighing apparatus of which the weighing hopper has a plurality of storage sections and which can prevent deterioration in the accuracy of weighing even when an object to be weighed is improperly supplied to the weighing hopper at the timing when the object to be weighed is not supposed to be supplied intrinsically. <P>SOLUTION: A controller redetects the holding amount of the weighing hopper by a weight sensor before the object to be weighed is discharged from the storage section, calculates variations of weighing hopper holding amount which is the difference between a weighing hopper holding amount which has been stored and the weighing hopper holding amount obtained through the redetection, and decides whether the object to be measured is allowed to be discharged from a storage section participating in an optimum combination or not on the basis of whether the sum of the total variations of the weighing hopper holding amount and the combination total weight of the optimum combination satisfies discharge conditions or not. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a combination weigher. More specifically, the present invention relates to a combination weigher provided with a weighing hopper having a plurality of storage units.

  When filling an object to be weighed into a container or the like as a product or the like, it is required to put a target amount of the object to be weighed into the container or the like accurately and automatically. For this purpose, there is a combination weigher.

  In a general combination weigher, an object to be weighed is put into a plurality of weighing hoppers, and the weight of the object to be weighed put into the weighing hopper is detected. Then, the combination in which the total weight when the weights are combined is closest to the target weight is selected. Finally, the objects to be weighed are discharged from the weighing hoppers participating in the combination.

  In the combination weigher, as the number of combination candidates increases, the measurement accuracy improves. For this reason, it is desirable to increase the number of weighing hoppers. On the other hand, if the number of weighing hoppers is increased, the apparatus becomes larger. Further, since the number of weight sensors attached to the weighing hopper increases, the apparatus becomes expensive. For this reason, in the combination weighers disclosed in Patent Literature 1 and Patent Literature 2, each storage hopper is provided with a plurality of storage units. Then, the objects to be weighed are sequentially supplied to the storage units, and the increase in the weight of the weighing hopper is set as the weight of the objects to be weighed held by the respective storage units. Thereby, the number of storage parts can be increased with respect to the number of weight sensors (the number of weighing hoppers). Therefore, the same effect as increasing the number of weighing hoppers can be obtained.

In addition, there is a case where an object to be weighed is erroneously supplied from a device (for example, a supply hopper) that supplies the object to be weighed to the weighing hopper when it is not the timing to originally supply the object to be weighed. As a countermeasure for such a situation, there is a combination weigher disclosed in Patent Document 3. In the combination weigher disclosed in Patent Document 3, the weight of the weighing hopper selected in the combination calculation is continuously detected until the object to be weighed is discharged from the weighing hopper. When the total weight of the weighing hopper selected in the combination calculation is out of the predetermined range, the weight of the weighing hopper is updated and the combination calculation is performed again.
Japanese Patent Publication No. Hei 4-38295 Patent Publication No. Hei 5-77247 Utility Model Registration Gazette No. 2565169

  However, the combination weigher in which the weighing hopper has a plurality of storage units has a problem that the weighing accuracy is lowered when the weighing object is supplied to the weighing hopper when the weighing object is not originally supplied. It was.

  The present invention has been made to solve the above-described problems, and is a combination weigher in which the weighing hopper has a plurality of storage units, and the weighing object is originally supplied to the weighing hopper when it is not time to supply the weighing object. It is an object of the present invention to provide a combination weigher capable of preventing a decrease in measurement accuracy even when the is supplied incorrectly.

  One example of the cause of erroneous supply is the biting of articles into the gate of the supply hopper. That is, some apparatuses (for example, linear feeders) that supply articles to the supply hopper supply articles by turning vibrations on and off. In this case, depending on the shape and viscosity of the article, the article may fall down to the supply hopper even after the vibration stops. If a fall from the linear feeder occurs while the discharge gate of the supply hopper is closed, the object to be weighed may bite into the gate. In this case, if the object to be weighed is held by the gate and does not fall on the weighing hopper, the weight detection value is not affected and there is no problem. However, after that, when a new article is supplied to the supply hopper and the bite is eliminated by the impact of the drop, the object to be weighed is erroneously supplied to the weighing hopper at an unintended timing by design. (Hereinafter, erroneous supply occurs).

  In the combination weigher disclosed in Patent Document 3, each weighing hopper has only one storage portion. For this reason, even if erroneous supply occurs, the measurement value (element used for the combination calculation) can be updated by detecting the weight of the measurement hopper again. However, in the combination weigher in which the weighing hopper is divided into a plurality of storage units, there is only one weight sensor for each weighing hopper, and even if the holding amount in the entire weighing hopper can be detected again, the individual storage units can be held. The amount cannot be updated. In addition, it is impossible to determine which storage unit has been erroneously supplied. Further, it is impossible to grasp in which part of which supply hopper a malfunction that causes erroneous supply occurs.

  The inventors of the present invention have intensively studied a method of discharging in a combination weigher having a plurality of storage units in a weighing hopper without causing a drop in weighing accuracy when an erroneous supply occurs. Here, when a certain storage unit participates in the optimum combination, it is assumed that an erroneous supply has occurred in the weighing hopper (selected weighing hopper) including the storage unit (selected storage unit). At this time, an erroneously supplied object to be weighed may be in the selected storage unit, but may be in a different storage unit of the same weighing hopper. However, the increase in the holding amount of the selective storage unit does not exceed the increase in the holding amount of the entire weighing hopper. That is, the total amount of objects to be weighed erroneously supplied to the selected storage unit does not exceed the total amount of objects to be weighed incorrectly supplied to the weighing hopper provided with the selection storage unit. Therefore, the actual discharge amount (the total amount of the objects to be weighed held by the selective storage unit) is the fluctuation amount of the holding amount of the weighing hopper (the holding amount at the time of combination calculation and the holding amount re-detected before discharging). The difference between the quantities: the sum of the weights of the objects to be weighed erroneously supplied to the selected weighing hopper) and the sum of the combined total weights of the optimum combination will not be exceeded. Therefore, even if an erroneous supply occurs, for example, if discharge is performed on the condition that the sum satisfies the discharge condition, the actual discharge amount naturally satisfies the discharge condition. Therefore, it is possible to prevent an increase in measurement error due to erroneous supply.

  In addition, if the sum does not satisfy the discharge condition, an error may occur if another combination calculation (forced combination calculation) is performed on condition that all storage units included in the weighing hopper in which erroneous supply has occurred are included in the combination. The storage section in which the supply has occurred can be returned. Further, when the discharge condition is not satisfied by the forced combination calculation, it is possible to prevent the storage portion of the weighing hopper in which the erroneous supply has occurred from participating in the combination and to perform the combination calculation again, thereby preventing a reduction in measurement accuracy. . In addition, it is possible to determine in which storage section an erroneous supply has occurred by taking the difference in the weighing hopper holding amount before and after discharging and comparing it with the stored measurement value. Furthermore, if information such as the time and state is stored in the case of erroneous supply, that information can be used for maintenance, which is convenient.

  Therefore, in order to solve the above problems, the combination weigher according to the present invention includes a weighing hopper that includes a plurality of storage units that hold and discharge the objects to be weighed, and a supply hopper that supplies the objects to be weighed to each of the storage units. And a weight sensor that detects a weighing hopper holding amount that is the weight of an object to be weighed held by the weighing hopper, and a control device, and the control device, when there is an empty storage portion, A first detection for detecting and storing the weighing hopper holding amount by a weight sensor is performed, and after the first detection, the control device controls the supply hopper to supply an object to be measured to the empty storage unit. The control device performs a second detection of detecting and storing the weighing hopper holding amount by the weight sensor after the supply, and the control device determines the result of the first detection and the second detection. Based on the empty The weight of the object to be weighed supplied to the storage unit is calculated and stored as a measured value, and the control device performs a first combination operation that is a combination operation using the measured value, thereby determining the object to be weighed. A combination that selects an optimal combination that is a combination of storage units to be discharged, and the control device discharges an object to be measured from a selected storage unit that is a storage unit that participates in the optimal combination when a predetermined condition is satisfied. The control device detects a weighing hopper holding amount of a selected weighing hopper, which is a weighing hopper having the selected storage portion, by the weight sensor before discharging the object to be weighed from the selected storage portion. A third detection is performed, and the control device determines, for each of the selected weighing hoppers, the weighing hopper holding amount stored when the weighing hopper becomes the selected weighing hopper and the third detection. The weighing hopper holding amount fluctuation amount, which is the difference between the measured weighing hopper holding amounts, is calculated, and the control device determines whether the sum of the weighing hopper holding amount fluctuation amount and the combined total weight of the optimum combination satisfies the discharge condition. Based on whether or not it is satisfied, it is determined whether or not the object to be weighed is discharged from the storage units participating in the optimum combination.

  As a result, if there is a large deviation between the weight of the object to be weighed (actual holding amount) and the measured value in the storage unit (a significant missupply has occurred), the storage It is possible to prevent the section from discharging the object to be weighed. Therefore, it is possible to prevent an increase in the error of the discharge amount resulting from the deviation of the measured value.

  In the combination weigher according to the present invention, when the sum does not satisfy the discharge condition, the control device sets the weighing hopper whose amount of fluctuation in the weighing hopper exceeds a predetermined threshold as an abnormal weighing hopper, and The second combination calculation is performed so that the weighing hopper holding amount of the abnormal weighing hopper stored when the weighing hopper becomes the selected weighing hopper always participates in the combination, and the discharge condition is determined by the second combination calculation. When a satisfying combination is obtained, the optimum combination may be updated.

  Thereby, about the storage part in which the missupply occurred, the storage parts belonging to the same weighing hopper can be made to participate in the combination and discharged. Even if the weighing hopper holding amount is detected again, the actual holding amount of the storage unit in which the erroneous supply has occurred cannot be individually known. However, the holding amount of the weighing hopper to which the storage unit belongs can be accurately grasped. In other words, even if individual weighing values cannot be updated, the total of weighing values belonging to the same weighing hopper can be accurately updated. Accordingly, it is possible to realize discharge with less error.

  Further, in the combination weigher according to the present invention, the control device is provided on the condition that the storage unit of the abnormal weighing hopper is not allowed to participate in the combination when the combination satisfying the discharge condition is not obtained in the second combination calculation. The first combination calculation may be performed again.

  As a result, the combination calculation can be performed again using only the measurement value that accurately reflects the weight of the object actually held in the storage unit. Therefore, the measurement accuracy can be improved.

  In the combination weigher according to the present invention, each weighing hopper has two storage units, and each supply hopper has two gates for selectively supplying objects to be measured to the storage unit, The control device performs a fourth detection by the weight sensor to detect the weighing hopper holding amount of the abnormal weighing hopper that has discharged the object to be weighed only in the storage portion on one side, and the control device is a result of the fourth detection. Based on the measurement value of the storage portion of the abnormal weighing hopper from which the object to be weighed has not been discharged, and based on the measurement value obtained by the recalculation and the result of the second detection Based on the obtained measured value, it may be determined which gate of which supply hopper is defective.

  Thereby, it can be determined to which storage unit the erroneous supply has occurred. Therefore, it can be determined from which gate of which supply hopper an erroneous supply is generated. Therefore, maintenance can be easily performed.

  The combination weigher according to the present invention further includes an output device, and the control device determines that the object to be weighed is not discharged from the storage unit participating in the first optimal combination and the second device. When there is no combination that satisfies the discharge conditions in the combination calculation, the fact and the time at which such occurrence occurred are stored and output, and which weighing hopper is determined to be an abnormal weighing hopper is stored. , Output, store and output the weighing hopper holding amount fluctuation amount of the abnormal weighing hopper, and store and output which supply hopper gate is determined to have the defect.

  Thereby, even when the operation is performed for a long time, it is possible to easily know at which point in time which storage unit or supply hopper has been erroneously supplied. Therefore, the user can perform maintenance work using the stored and displayed information.

  The present invention has the above-described configuration and has the following effects. That is, the weighing hopper is a combination weigher having a plurality of storage units, and the weighing accuracy is reduced even when the weighing object is erroneously supplied to the weighing hopper when it is not the timing to supply the weighing object. It becomes possible to provide a combination scale that can be prevented.

Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments.
(First embodiment)
[Construction]
FIG. 1 is a diagram showing a part of a schematic configuration when the combination weigher according to the first embodiment of the present invention is cut in the vertical direction. A plurality of linear feeder pans 5, linear feeders 6, supply hoppers 7, weighing hoppers 9, storage units 9 a and 9 b, collective chutes 11, and weight sensors 13 are provided. However, one each is a set, and each set has the same configuration. Therefore, only one set is shown in the figure, and the remainder is omitted. In addition, the circle mark in a figure shows a to-be-measured object. Hereinafter, the hardware and control system of the combination weigher according to the present embodiment will be described with reference to FIG.

  First, the hardware will be described below. As shown in FIG. 1, the hardware of the combination weigher of this embodiment includes a supply device 1 that supplies an object to be weighed, and a top cone 3 that distributes the object to be weighed supplied from the supply device 1 and supplies it downstream. A main feeder 4 that vibrates the top cone 3, a plurality of linear feeder pans 5 that receive an object to be weighed from the top cone 3 and supplies it downstream, a plurality of linear feeders 6 that vibrate the linear feeder pan 5, A plurality of supply hoppers 7 that are provided with a plurality of gates 10a and 10b and receive an object to be weighed from the linear feeder pan 5 and are supplied downstream, and are supplied from the supply hopper 7 that is provided with two storage portions 9a and 9b and a gate. A plurality of weighing hoppers 9 for receiving the objects to be weighed and supplying them downstream, and a plurality of collecting chutes for receiving and collecting the objects to be weighed from the weighing hoppers 9 and supplying them to the downstream 1, and a collection funnel 12 to discharge to the packaging machine (not shown) receives the objects to be weighed supplied from the collecting chute 11. The two gates of the weighing hopper 9 can be selectively opened, and it is configured so that it can be selected from which of the storage portions 9a and 9b the object to be weighed is discharged depending on which gate is opened. . The two gates of the supply hopper 7 can be selectively opened, and it is configured to be able to select which of the storage portions 9a and 9b is to supply an object to be weighed depending on which gate is opened. . Further, the gates 10a and 10b of the supply hopper 7 are assigned with individual identification numbers (gate numbers), and if the gate number is designated, which gate 10a or 10b of which supply hopper 7 is specified. It can be done.

  In the present embodiment, for example, a belt conveyor in which a plurality of containers are arranged in a row on an endless belt, a passage provided with a vibration device, or the like is used as the supply device 1. Moreover, the main feeder 4 and the linear feeder 6 vibrate by ON-OFF of the electromagnet provided in the vibration part, for example.

  Next, the control system will be described below. As shown in FIG. 1, the control system of the combination weigher according to the present embodiment supplies a level sensor 2 that detects the amount of an object to be weighed supplied from the supply device 1 to the top cone 3, and supplies the weighing hopper 9 from the supply hopper 7. A weight sensor 13 for detecting the weight of the measured object, a control device 14, and an input / output device 15 are provided.

  For example, an optical sensor is used as the level sensor 3 in the present embodiment. For example, a load cell is used for the weight sensor 13. For example, a microcomputer is used as the control device 14. For example, a touch panel is used as the input / output device 15. Here, the input / output device 15 does not necessarily have to be single, and the input device and the output device may be provided separately. In addition, the arrow in a figure shows the direction where a signal is transmitted.

  Next, the configuration of the control device 14 will be described. FIG. 2 is a block diagram illustrating a schematic configuration of the control device 14 included in the combination weigher according to the first embodiment of the present invention. As shown in FIG. 2, the control device 14 includes a calculation unit 16, a storage unit 17, an I / O circuit 18, an A / D conversion circuit 19, a gate drive circuit 20, a vibration control circuit 21, a time count. Part 22. For example, a CPU is used as the calculation unit 16. For the storage unit 17, for example, an internal memory is used. For the clock unit 22, for example, a calendar circuit with a clock is used. The memory | storage part 17 and the time measuring part 22 are connected so that it can communicate with the calculating part 16 mutually. The I / O circuit 18 and the A / D conversion circuit 19 are connected to the calculation unit 16 so that each can transmit a signal to the calculation unit 16. Each of the gate drive circuit 20 and the vibration control circuit 21 is connected to the calculation unit 16 so that a signal from the calculation unit 16 can be received. The arithmetic unit 16 is further connected to the input / output device 15 so as to communicate with each other. The I / O circuit 18 is connected to the level sensor 2 so that a signal from the level sensor 2 can be received. The A / D conversion circuit 19 is connected to the weight sensor 13 so that the signal from the weight sensor 13 can be received. The gate drive circuit 20 is connected to the supply hopper 7 and the weighing hopper 9 so that signals can be output to the supply hopper 7 and the weighing hopper 9. The vibration control circuit 21 is connected to the supply device 1, the main feeder 4, and the linear feeder 6 so that signals can be transmitted to the supply device 1, the main feeder 4, and the linear feeder 6. In addition, the arrow in a figure shows the direction where a signal is transmitted.

  Next, the operation of the control device 14 will be described with reference to FIG. A parameter indicating a combination target weight, an operation speed condition, or the like is input to the calculation unit 16 from the input / output device 15. The calculation unit 16 stores the received parameters in the storage unit 17. The stored parameters and the like are read by the calculation unit 16 and output to the input / output device 15 as necessary, and are confirmed by the user. The storage unit 17 also stores a program for performing a combination calculation. A detection signal from the level sensor 2 is input to the arithmetic unit 16 via the I / O circuit 18. The detection signal from the weight sensor 13 is converted into a detection value by the A / D conversion circuit 19 and sent to the calculation unit 16. The computing unit 16 processes the received detection signal and the like using a program stored in the storage unit 17. Furthermore, the arithmetic unit 16 gives a control signal to the gate drive circuit 20 and the vibration control circuit 21 based on the processing result. Thereby, the calculating part 16 controls the supply apparatus 1, the supply hopper 7, and the weighing hopper 9. Further, the calculation unit 16 controls the top cone 3 and the linear feeder pan 5 via the main feeder 4 and the linear feeder 6, respectively. In addition, the calculation unit 16 outputs a processing result to the input / output device 15 as necessary. In addition, the arithmetic unit 16 receives the date and time from the time measuring unit 22 and stores them in the storage unit 17 when a certain processing result is generated. With the above operation, the control device 14 detects and controls the weight of the objects to be weighed supplied and discharged by the feeding device 1, the top cone 3, the linear feeder pan 5, the feeding hopper 7, and the weighing hopper 9, and operates the combination weigher. To do. In addition, the control device 14 outputs information obtained as a result of operation, the date and time when a failure occurs, the content of the failure, etc. to the input / output device 15 and stores them in the storage unit 17.

  In the combination weigher of this embodiment, the number of the control device 14 and the calculation unit 16 is one. However, a plurality of calculation units and control devices may be provided. That is, the control by the arithmetic unit and the control device may be centralized control or distributed control. The storage unit 17 need not be single, and the combination weigher of the present embodiment may include a plurality of storage units.

Moreover, the combination weigher of this embodiment is used in combination with a packaging machine (not shown). A discharge signal is output from the packaging machine in accordance with the timing of packaging of the objects to be weighed by the packaging machine. Although not shown in FIG. 2, the calculation unit 16 is also connected to the packaging machine so as to be able to receive the discharge signal.
[Outline of operation]
First, an outline of operation in the combination weigher of this embodiment will be described.

The object to be weighed is supplied from the supply device 1 to the top cone 3. Here, the layer thickness of the object to be weighed supplied on the top cone 3 is detected by the level sensor 2, and the detection result is sent to the control device 14. The control device 14 vibrates the supply device 1 at a predetermined time and intensity based on the obtained detection value, and controls the amount of the object to be weighed supplied to the top cone 3. The control device 14 also vibrates the main feeder 4 at a predetermined time and intensity, and the object to be weighed on the top cone 3 is supplied to the linear feeder pan 5. Further, the control device 14 vibrates the linear feeder 6 at a predetermined time and intensity, and the object to be weighed on the linear feeder pan 5 is supplied to the supply hopper 7. Next, when the storage unit 9a or 9b is empty, the control device 14 opens the gates 10a and 10b of the corresponding supply hopper 7, and supplies the objects to be weighed to the storage unit 9a or 9b. When an object to be weighed is supplied to the storage portion 9a or 9b, the weight sensor 13 disposed in the corresponding weighing hopper 9 detects the weight of the object to be weighed held by the weighing hopper (weighing hopper holding amount). . The weight detection result is sent to the control device 14. The control device 14 calculates and stores the measurement value based on the detection result, and performs a combination calculation. That is, the control device 14 selects an optimum combination based on the combination target weight. Thereafter, the control device 14 gives a command to the gates of the weighing hoppers 9 corresponding to the storage units 9a and 9b participating in the optimum combination, and discharges the objects to be weighed. The discharged objects to be weighed are collected by the collecting chute 11 and the collecting funnel 12 and discharged to a packaging machine (not shown). Thereafter, by repeating the same operation as described above, an amount of an object to be weighed that satisfies a certain condition is discharged to the packaging machine. A series of operations starting from the supply of the objects to be weighed from the supply hopper 7 to the discharge from the collective funnel 12 is referred to as one weighing cycle.
[Details of operation]
FIG. 3 is a diagram illustrating an example of an operation program of the control device 14 in the combination weigher according to the first embodiment of the present invention. Hereinafter, the operation of the combination weigher of this embodiment will be described in detail with reference to FIG. In the following description, the number of weighing hoppers 9 provided in one combination weigher of this embodiment is n.

First, the flow of operation at the start of operation will be described in order.
1. Supplying an object to be weighed to the weighing hopper When the operation program is started, first, 1 is assigned to the variable i in step S1. Thereafter, the first and nth weighing hoppers are sequentially checked and supplied to the a-side and b-side storage units. First, the a-side check and supply are performed, and then the b-side check and supply are performed.
1.1. Checking and Supplying on the a Side of the Weighing Hopper When step S1 is completed, first, checking and supplying are performed on the storage portion on the a side of the weighing hopper. That is, in step S2, the control device 14 determines whether or not the storage part 9ai on the a side of the i-th weighing hopper 9i is empty (whether or not it is discharged). In this determination, for example, the discharge flag is turned on when the object to be weighed is discharged from the storage unit 9ai (step S21), and the discharge flag is turned off when the object to be weighed is inserted into the storage unit 9ai (step S4). This can be done by determining whether the discharge flag is ON / OFF.

  If it is determined in step S2 that the a-side storage unit 9ai is empty, the process proceeds to step S3. In step S3, the control device 14 detects and stores the weight (weighing hopper holding amount) of the object to be weighed held by the weighing hopper 9i via the weight sensor 13i (first detection).

  Next, in step S4, the control device 14 controls the supply hopper 7i and puts an object to be weighed into the storage portion 9ai.

  Next, in step S5, the control device 14 detects again and stores the weighing hopper holding amount of the weighing hopper 9i (second detection).

Next, in step S6, the control device 14 increases the increment of the weighing hopper holding amount of the weighing hopper 9i (the weighing hopper holding amount of the weighing hopper 9i stored in step S3 and the weighing of the weighing hopper 9i stored in step S5. Difference from hopper holding amount: The difference between the weighing hopper holding amount in the first detection and the second detection) is stored as the weight (measurement value) of the weighing object held in the storage portion 9ai. This completes the check and supply of the storage part on the a side of the i-th weighing hopper. When step S6 is completed, the control device 14 proceeds to step S7, adds 1 to the variable i, and repeats the same operation until i exceeds n.
1.2. Check and supply on the b side of the weighing hopper If it is determined in step S2 that the a side storage portion 9ai is not empty, the b side storage portion of the weighing hopper is checked and supplied. In this case, the control device 14 proceeds to step S8, and determines whether or not the storage portion 9bi on the b side of the i-th weighing hopper 9i is empty (whether or not it is discharged). In this determination, for example, the discharge flag is turned on when the object to be weighed is discharged from the storage unit 9bi (step S21), and the discharge flag is turned off when the object to be weighed is inserted into the storage unit 9bi (step S10). This can be done by determining whether the discharge flag is ON / OFF.

  If it is determined in step S8 that the b-side storage unit 9bi is empty, the control device 14 proceeds to step S9. In step S9, the control device 14 detects and stores the weighing hopper holding amount of the weighing hopper 9i via the weight sensor 13i (first detection).

  Next, in step S10, the control device 14 controls the supply hopper 7i, and puts an object to be weighed into the storage portion 9bi.

  Next, in step S11, the control device 14 detects again and stores the weighing hopper holding amount of the weighing hopper 9i (second detection).

  Next, in step S12, the control device 14 increases the increment of the weighing hopper holding amount of the weighing hopper 9i (the weighing hopper holding amount of the weighing hopper 9i stored in step S9 and the weighing of the weighing hopper 9i stored in step S5). Difference from hopper holding amount: difference between weighing hopper holding amount in first detection and second detection) is stored as a measured value in storage portion 9bi. Then, it progresses to step S7.

If it is determined in step S8 that the storage unit 9bi on the b side is not empty, there is no need to put an object to be measured into any of the storage units 9ai and 9bi. Proceed to step S7.
1.3. Determination of repetition When the check and supply of the storage section of the i-th weighing hopper are completed, it is checked whether the check and supply have been completed for all the weighing hoppers.

  That is, if it progresses to step S7, the control apparatus 14 will add 1 to the variable i (i + 1 is substituted to the variable i).

  Next, in step S13, the control device 14 determines whether or not the variable i is larger than n.

If it is determined in step S13 that the variable i is not larger than n, it means that there is a weighing hopper that has not been checked and supplied yet. In this case, the control device 14 returns to step S2. Accordingly, the check and supply are sequentially performed on the first to nth weighing hoppers.
2. In the first combination calculation step S13, when it is determined that the variable i is larger than n, the supply of the object to be weighed to the weighing hopper is finished. At this time, the control device 14 proceeds to the combination calculation step. That is, the control device 14 proceeds to step S14, and determines whether or not a combination completion flag (a flag indicating whether or not a combination calculation has already been performed in the measurement cycle) is ON.

  At the start of operation, the combination completion flag is turned off. Therefore, in step S14, it is determined that the combination completion flag is not ON. In response to this, the control device 14 proceeds to step S15, and performs a combination calculation using the measured values of the storage units 9a and 9b (first combination calculation). Here, the combination calculation is to select a combination of storage units that optimizes the total of measured values. For example, the total weight of the measurement values (combination total weight) is calculated for a combination in which one or a plurality are extracted from all the measurement values. Then, the combination whose combination weight is larger than the combination target weight but closest to the combination target weight is selected. And when the total of the measured value by the combination satisfy | fills discharge conditions, it memorize | stores as an optimal combination. In the first combination calculation, the combination calculation is performed using only the measured value of the storage unit in which the combination prohibition flag is not ON. Since the combination prohibition flag is OFF for all the storage units at the start of operation, the measurement values of all the storage units 9a and 9b participate in the combination calculation. As will be described in detail later, the combination prohibition flag will be briefly described. When the discharge condition is not satisfied due to erroneous supply to the weighing hopper, the storage portion of the weighing hopper in which the erroneous supply has occurred is turned ON. (Step S48). If there is a storage unit for which the combination prohibition flag is ON, the storage unit is excluded and the combination calculation is performed. When a combination that satisfies the discharge condition cannot be obtained in the first combination calculation, for example, processing such as forced discharge and operation stop may be performed.

  Next, in step S16, the control device 14 turns on the combination completion flag.

Next, in step S17, the control device 14 updates the variable WC with the total (combination total weight) of the measured values of the storage units 9a and 9b (selected storage units) participating in the first optimal combination. Thereafter, the control device 14 returns to step S14.
3. When the discharge combination calculation is completed, the control device 14 discharges the object to be weighed. When the combination calculation is completed, the combination completion flag is ON. Therefore, the control device 14 proceeds from step S14 to step S18. In step S18, the control device 14 determines whether or not a discharge signal is input from the packaging machine or the like.

  If the preparation of the packaging machine is completed, a discharge signal is input to the control device 14 from the packaging machine. Receiving this, the control apparatus 14 progresses to step S19. In step S19, the control device 14 discharges the objects to be weighed from the storage units 9a and 9b (selective storage unit) participating in the optimum combination. As a result, the objects to be weighed are collected in the collecting funnel 12 via the collecting chute 11 and discharged to the packaging machine.

  Next, in step S20, the control device 14 turns off the combination completion flag.

  Next, in step S <b> 21, the control device 14 clears (sets to zero) the measured values of the discharged storage units 9 a and 9 b. This is because the object to be weighed is not held in the discharged storage part.

  Next, in step S22, the control device 14 substitutes 1 for the variable i.

  Next, in step S23, the control device 14 determines whether or not the storage portion 9ai or 9bi of the i-th weighing hopper 9i has participated in the optimum combination in the immediately preceding step S19 (whether or not the object to be weighed has been discharged). Make a decision.

  If it is determined in step S23 that the storage section 9ai or 9bi of the i-th weighing hopper 9i has not participated in the optimum combination in the immediately preceding step S19 (the object to be weighed has not been discharged), the control device No. 14 proceeds to step S32 (described later) in order to make a repeat determination.

  If it is determined in step S23 that the storage portion 9ai or 9bi of the i-th weighing hopper 9i has participated in the optimum combination (discharges the object to be weighed) in the immediately preceding step S19, the control device 14 performs step S24. Proceed to In step S24, the control device 14 determines whether or not the abnormality flag of the i-th weighing hopper 9i is ON.

  At the start of operation, the abnormality flag is OFF for all the weighing hoppers. For this reason, in step S24, it is determined that the abnormality flag of the i-th weighing hopper 9i is not ON. In response to this, the control device 14 proceeds to step S32 in order to make repeated determinations.

  In step S32, the control device 14 adds 1 to the variable i (i + 1 is substituted for the variable i).

  Next, in step S33, the control device 14 determines whether or not the variable i is larger than n.

  If it is determined in step S33 that the variable i is not greater than n, it means that there is a weighing hopper that has not yet been checked for an abnormality flag. In response to this, the control device 14 returns to step S23.

If it is determined in step S33 that the variable i is greater than n, the object to be weighed has already been discharged, and the check of the abnormality flag has been completed for all the weighing hoppers. In response to this, the control device 14 returns to step S1. That is, at this point, one metering cycle is completed and the controller 14 starts a new metering cycle.
4). Detection and handling of incorrect supply To 3. In the description of, the operation is described on the assumption that the operation is started (when there is no erroneous supply of an object to be weighed from the supply hopper). Below, the case where the incorrect supply has arisen is demonstrated. Detection and processing of erroneous supply is performed between the discharge of the object to be measured and the next discharge.

When the objects to be weighed are discharged from the combination weigher, the packaging machine packages the objects to be weighed and prepares for the next packaging. For this reason, the discharge signal is not input for a while. In the meantime, the control device 14 supplies the objects to be weighed to the weighing hopper (steps S1 to S13), performs a combination operation (steps S14 to S17), and detects and processes an erroneous supply of the objects to be weighed to the weighing hopper. I do. Since the supply of the object to be weighed to the weighing hopper and the combination calculation are the same as those described above, the description thereof will be omitted. Hereinafter, detection and processing of erroneous supply will be described.
4.1. Detection of erroneous supply When it is determined in step S18 that the discharge signal is not input, the control device 14 proceeds to step S34. In step S34, the control device 14 substitutes 1 for the variable i.

  Next, in step S35, the control device 14 determines whether or not at least one of the storage portions 9ai or 9bi of the i-th weighing hopper 9i participates in the optimum combination (at least one of the storage portions 9ai or 9bi is the selected storage portion). Whether or not). Hereinafter, the weighing hopper having the selective storage portion is referred to as a selective weighing hopper. That is, in step S35, it is determined whether or not the weighing hopper 9i is a selected weighing hopper.

  If it is determined in step S35 that at least one of the storage portions 9ai or 9bi of the i-th weighing hopper 9i is participating in the optimum combination (the weighing hopper 9i is the selected weighing hopper), the control device 14 The process proceeds to step S36. In step S36, the control device 14 detects and stores the weighing hopper holding amount of the weighing hopper 9i again (third detection).

  Next, in step S37, the control device 14 determines the amount of change in the weighing hopper holding amount of the weighing hopper 9i (the stored weighing hopper holding amount of the weighing hopper 9i and the weighing hopper 9i obtained in the third detection. The difference from the weighing hopper holding amount: hereinafter, the weighing hopper holding amount fluctuation amount) is substituted into the variable αi. Here, the “measured hopper holding amount of the weighing hopper 9i” is, in principle, the weighing hopper holding amount stored at the time of the first combination calculation (step S15) (obtained by the second detection). It refers to the weighing hopper holding amount). However, when the second combination calculation (step S44) has already been performed in the same weighing cycle and the optimum combination has been updated, the time of the second combination calculation (that is, immediately before the second combination calculation). It is desirable to calculate the increment by setting the weighing hopper holding amount stored in step S36 of the third detection) as the “stored weighing hopper holding amount of the weighing hopper 9i”. That is, it is desirable to calculate the fluctuation amount based on the weighing hopper holding amount stored when the weighing hopper 9i becomes the selected weighing hopper. Thereby, it is possible to grasp the weight of the object to be weighed erroneously supplied to the selection storage unit after the time when the optimum combination is selected.

  Next, in step S38, the control device 14 determines whether or not the variable αi (measurement hopper holding amount fluctuation amount) exceeds a predetermined threshold value (δ). Here, the value of δ may be zero, but it is preferable to set a constant positive value that is not zero in consideration of the error of the weight sensor 13. If αi exceeds δ, it is determined that an erroneous supply has occurred. That is, the combination weigher of the present embodiment detects erroneous supply based on the amount of change in the weighing hopper holding amount.

  In step S38, when it is determined that the variable αi exceeds the predetermined threshold value (δ), the control device 14 turns on the abnormality flag of the i-th weighing hopper 9i. Hereinafter, the weighing hopper in which the abnormality flag is turned on is referred to as an abnormal weighing hopper. The abnormal weighing hopper is a weighing hopper determined to be a weighing hopper in which an erroneous supply has occurred.

  Next, in step S40, the control device 14 adds 1 to the variable i (i + 1 is substituted for the variable i).

  Next, in step S41, the control device 14 determines whether or not the variable i is larger than n.

  If it is determined in step S41 that the variable i is not greater than n, the control device 14 returns to step S35.

  If it is determined in step S35 that none of the storage units 9ai and 9bi of the i-th weighing hopper 9i participates in the optimum combination, the control device 14 proceeds to step S40.

  If it is determined in step S38 that the variable αi (the amount of change in the weighing hopper holding amount) does not exceed the predetermined threshold value (δ), the control device 14 proceeds to step S40.

  If it is determined in step S41 that the variable i is larger than n, detection of erroneous supply has already been completed for all the weighing hoppers. Therefore, the control device 14 proceeds to step S42.

  Next, the control device 14 determines whether to perform the discharge as it is or to perform a separate process depending on the degree (severity level) of erroneous supply. That is, in step S42, the control device 14 determines whether or not the sum of the WC + Σαi (= WC + α1 + α2 + α3 +... + Αn), that is, the sum of the measured hopper holding amount variation amount and the combined total weight of the optimum combination satisfies the discharge condition. Judgment is made. This determination can be made, for example, based on whether or not the difference between WC + Σαi and the combination target weight is within a certain range.

In step S42, when it is determined that WC + Σαi satisfies the discharge condition, there is no erroneous supply, or even if it does not interfere with discharge. Therefore, the control board 14 returns to step S14. If the combination calculation is completed (step S14) and the discharge signal is input (step S18), the object to be weighed is discharged as it is (step S19).
4.2. Processing when incorrect supply occurs If an incorrect supply occurs in the weighing hopper and the discharge conditions are not satisfied, the forced combination calculation (second combination calculation) and the determination of the storage section where the incorrect supply has occurred Is done.
4.2.1. Forced combination operation (second combination operation)
That is, when it is determined in step S42 that WC + Σαi does not satisfy the discharge condition, the control device 14 proceeds to step S43. In step S <b> 43, the control device 14 stores in the storage unit 17 the fact that the discharge condition has not been satisfied due to fluctuations in the holding amount of the weighing hopper and the time at that time, and displays it on the input / output device 15.

  Next, in step S44, the control device 14 performs combination calculation (second combination calculation: forced combination calculation) so that all the storage units 9a and 9b of the weighing hopper 9 whose abnormality flag is ON participate in the optimal combination. ). That is, the combination calculation is performed on the condition that the weighing hopper holding amount obtained by the third detection (the total of the measured values of the storage portions 9a and 9b of the weighing hopper 9 whose abnormality flag is ON) is included in the combination. This means that the storage portions 9a and 9b are integrated and participate in the combination.

  Next, in step S45, the control device 14 determines whether or not a combination satisfying the discharge condition is obtained in step S44.

  If it is determined in step S45 that a combination that satisfies the discharge conditions has been obtained, the control device 14 proceeds to step S46. In step S46, the control device 14 updates the optimal combination based on the result of the second combination calculation. As a result, the weighing storage unit in which erroneous supply has occurred can participate in the optimum combination without being affected by the deviation of the weighing value. Accordingly, accurate weighing can be performed, and at the same time, a weighing hopper in which an erroneous supply has occurred can be returned.

  Next, in step S47, the control device 14 updates the variable WC with the combined total weight based on the optimum combination in step S46. Thereafter, the control device 14 returns to step S14. Thereby, the control apparatus 14 discharges | emits by the optimal combination based on a 2nd combination calculation (forced combination calculation).

  If it is determined in step S45 that no combination satisfying the discharge conditions has been obtained, the control device 14 proceeds to step S48. In step S48, the control device 14 turns ON the combination prohibition flag of the storage portions 9a and 9b of the weighing hopper 9 whose abnormality flag is ON.

  Next, in step S <b> 49, the control device 14 stores the storage units 9 a and 9 b (or the corresponding weighing hoppers 9) for which the combination prohibition flag is turned on in the storage unit 17 and displays them on the input / output device 15.

Next, in step S50, the control device 14 turns off the combination completion flag. Thereafter, the control device 14 returns to step S14. Since the combination completion flag is OFF, the process proceeds to step S15 and the combination calculation is performed again. In the second combination calculation, the abnormal weighing hopper is prohibited from participating in the combination calculation (step S15). Therefore, the combination calculation can be performed using only the measurement value of the storage unit for which the holding amount can be accurately grasped, and the reduction of the measurement accuracy can be prevented.
4.2.2. Judgment of storage units with erroneous supply When an erroneous supply of an object to be weighed to a weighing hopper with multiple storage units occurs, each storage unit is not equipped with a weight sensor, so any storage unit can be left as it is. It is not possible to grasp whether an incorrect supply has occurred in the department. Therefore, in the combination weigher of this embodiment, for the weighing hopper in which erroneous supply has occurred (the abnormality flag is ON), the weighing value is re-detected after the object to be weighed is discharged to the memory hopper, and the weighing is stored. By comparing with the value, it is determined which storage unit has been erroneously supplied. When an erroneous supply occurs, the control device 14 turns on the abnormality flag for the weighing hopper. As already described, if the optimum combination is obtained by either the normal combination calculation (step S15) or the forced combination calculation (step S44), the process proceeds to step S19, and the object to be weighed is discharged. Since the same operation is performed up to step S24 regardless of the presence or absence of the abnormal weighing hopper, the description of the overlapping parts is omitted.

  In step S24, it is determined whether or not there is an erroneous supply (whether the abnormality flag is ON) to the weighing hopper that has participated in the optimal combination in the weighing cycle (has discharged the object to be weighed). If it is determined in step S24 that the abnormality flag of the i-th weighing hopper 9i is ON, the control device 14 proceeds to step S25. In step S25, the control device 14 determines whether or not the storage units 9ai and 9bi of the i-th weighing hopper 9i have both participated in the optimum combination (discharged the object to be weighed) in the immediately preceding step S19.

  In step S25, the storage portions 9ai and 9bi of the i-th weighing hopper 9i are not participating in the optimum combination in the immediately preceding step S19 (the object to be weighed is not discharged), that is, only one side is discharged. If determined to be, the control device 14 proceeds to step S26. In step S26, the control device 14 redetects the weighing hopper holding amount of the i-th weighing hopper 9i via the weight sensor 13i (fourth detection). The measured value of the storage portion 9ai or 9bi on the side from which the object to be weighed is not discharged is updated by the obtained weighing hopper holding amount.

  Next, in step S27, the control device 14 determines whether or not the updated measurement value is equal to the measurement value before the update.

  If it is determined in step S27 that the updated measured value is not equal to the measured value before update, the control device 14 proceeds to step S28. In step S28, the control device 14 indicates that there is a problem in the gates 10a and 10b of the supply hopper 7 corresponding to the storage portion 9ai or 9bi on the side that has not been discharged (the wrong object has been supplied) 10a or 10b gate number), the time at that time, and the weighing hopper holding amount variation (αi) of the weighing hopper 9i are stored in the storage unit 17 and displayed on the input / output device 15.

  Next, in step S29, the control device 14 turns off the abnormality flag of the i-th weighing hopper 9i and turns off the combination prohibition flag of the storage units 9ai and 9bi. This is because at least one of the storage portions 9ai or 9bi has already discharged the object to be weighed, so that accurate measurement values are obtained at this time for the storage portions 9ai and 9bi of the weighing hopper 9i. .

  If it is determined in step S25 that the storage units 9ai and 9bi of the i-th weighing hopper 9i have both joined the optimal combination (discharged the object to be weighed) in the previous step S19, the control device 14 The process proceeds to step S30. In step S30, the control device 14 may have a problem in the gates 10a and 10b of the supply hopper 7 corresponding to the storage portions 9ai and 9bi on both sides (there may be an erroneous supply of the object to be weighed). The fact (the gate number of the gates 10a and 10b), the time at that time, and the amount of change in the weighing hopper holding amount (αi) of the weighing hopper 9i are stored in the storage unit 17 and displayed on the input / output device 15. Thereafter, the control device 14 proceeds to step S29.

  When it is determined in step S27 that the recalculated measurement value is equal to the stored measurement value, the control device 14 proceeds to step S31. In step S31, the control device 14 indicates that there is a problem in the gate 10a or 10b of the supply hopper 7 corresponding to the storage portion 9ai or 9bi on the discharged side (the object to be weighed was erroneously supplied) (the gate 10a or 10b), the time at that time, and the weighing hopper holding amount fluctuation amount (αi) of the weighing hopper 9i are stored in the storage unit 17 and displayed on the input / output device 15. Thereafter, the control device 14 proceeds to step S29.

  When step S29 ends, the control device 14 proceeds to step S32. Since the subsequent operation has already been described, the description thereof is omitted.

Through the operation as described above, the combination weigher of the present embodiment discharges an object to be weighed in an amount close to the combination target weight using combination calculation while detecting and processing erroneous supply.
[Features and effects]
The main features of the combination weigher of this embodiment are roughly divided into five.

  The first feature of the combination weigher of this embodiment is based on whether or not the sum of the amount of change in the weighing hopper holding amount and the combined total weight of the optimum combination satisfies the discharge condition before discharging the object to be weighed. Thus, it is determined whether or not to discharge according to the optimum combination at that time. That is, the weighing hopper holding amount of the weighing hopper having the storage part participating in the optimum combination is detected (step S36: third detection), and the difference from the stored weighing hopper holding amount (the weighing hopper holding amount fluctuation amount) Is calculated (step S37). Then, it is determined whether the sum of the weighing hopper holding amount fluctuation amount and the combined total weight WC of the optimum combination satisfies the discharge condition (step S42). If the condition is satisfied, the operation is continued as it is (step S14). On the other hand, if the above condition is not satisfied, the optimum combination does not discharge.

  As a result, if there is a large deviation between the weight of the object to be weighed (actual holding amount) and the measured value in the storage unit (a significant missupply has occurred), the storage It is possible to prevent the section from discharging the object to be weighed. Therefore, it is possible to prevent an increase in the error of the discharge amount resulting from the deviation of the measured value.

  The second feature of the combination weigher of the present embodiment is that when the sum of the weighing hopper holding amount fluctuation amount and the combined total weight of the optimum combination does not satisfy the discharge condition, the weighing hopper holding amount fluctuation amount is a predetermined threshold value. The combination calculation is performed so that all the storage units belonging to the weighing hoppers exceeding the limit are forced to participate in the optimum combination. That is, it is determined whether or not the weighing hopper holding amount fluctuation amount exceeds a predetermined threshold (step S38), and the abnormality flag of the weighing hopper (abnormal weighing hopper) exceeding the threshold is turned ON (step S39). When the sum of the total amount of change in the weighing hopper holding amount and the combined total weight WC of the optimum combination does not satisfy the discharge condition, the second value is set so as to include all the storage units of the weighing hopper whose abnormality flag is ON. A combination calculation (forced combination calculation) is tried (step S44). If there is a combination that satisfies the discharge condition in the forced combination calculation, the optimum combination is updated (step S46), the combined total weight WC of the optimum combination is updated (step S47), and the operation is continued.

  Thereby, about the storage part in which the missupply occurred, the storage parts belonging to the same weighing hopper can be made to participate in the combination and discharged. Even if the weighing hopper holding amount is detected again, the actual holding amount of the storage unit in which the erroneous supply has occurred cannot be individually known. However, the holding amount of the weighing hopper to which the storage unit belongs can be accurately grasped. In other words, even if individual weighing values cannot be updated, the total of weighing values belonging to the same weighing hopper can be accurately updated. Accordingly, it is possible to realize discharge with less error.

  A third feature of the combination weigher according to the present embodiment is that, when a combination that satisfies the discharge condition is not obtained by the forced combination calculation, it is prohibited that a storage unit that may have been erroneously supplied participates in the combination. It is in. In the present embodiment, this operation is realized by using a combination prohibition flag. The combination prohibition flag is set to ON for the storage portion of the abnormal weighing hopper when a combination that satisfies the discharge condition is not obtained in the second combination calculation (step S48). In the storage section in which the combination prohibition flag is ON, there is a possibility that a deviation occurs between the stored measurement value and the weight of the object to be weighed actually held in the storage section. If the storage unit is allowed to participate in the combination in such a state, there is a possibility that a deviation occurs between the combined total weight obtained as a result of the calculation and the weight of the actually weighed object to be measured, resulting in a decrease in measurement accuracy. is there. Therefore, the storage unit is not allowed to participate in the first combination calculation (step S14).

  As a result, the combination calculation can be performed again using only the measurement value that accurately reflects the weight of the object actually held in the storage unit. Therefore, the measurement accuracy can be improved.

  A fourth feature of the combination weigher of the present embodiment is that it is possible to specify a storage unit in which an erroneous supply has occurred. That is, when only the storage unit on one side discharges the object to be weighed (if NO is determined in step S25), the holding amount of the weighing hopper is detected again, and the measurement value of the storage unit that has not been discharged is updated. (Step S26). Then, if the updated measured value is equal to the measured value before the update, it is determined that an erroneous supply has occurred in the discharged storage unit (step S31). Conversely, if the updated measured value is different from the updated measured value, it is determined that an erroneous supply has occurred in the storage unit that has not been discharged (step S28).

  As a result, it is possible to determine to which storage section the erroneous supply has occurred under a certain condition. Therefore, it can be determined from which gate of which supply hopper an erroneous supply is generated. Therefore, maintenance can be easily performed.

  The fifth feature of the combination weigher of this embodiment is that it stores and outputs relevant information when an erroneous supply occurs. That is, if an incorrect supply is detected in the supply hopper (or storage unit), if the discharge condition is not satisfied due to an incorrect supply, or if a storage unit is prohibited from participating in the combination, that fact and The time at that time is stored and displayed (steps S28, S30, S31, S43). Further, the storage section (the storage section of the abnormal weighing hopper) whose combination prohibition flag is turned on is displayed and stored (step S49).

Thereby, even when the operation is performed for a long time, it is possible to easily know at which point in time which storage unit or supply hopper has been erroneously supplied. Therefore, the user can perform maintenance work using the stored and displayed information.
[Modification]
In the present embodiment, the storage unit in which the combination prohibition flag is ON is not allowed to participate in the forced combination calculation (step S45) in the subsequent measurement cycle. As a result, the operation of the storage unit once prohibited from participating in the combination is stopped until the contents are discarded by manual work or the like.

  However, once the object to be weighed is discharged from another storage unit and the object to be weighed is newly supplied, each measured value changes. Therefore, the discharge condition may be satisfied even when using a storage unit whose combination prohibition flag is ON. In consideration of such a case, the second combination calculation performed thereafter may be allowed to participate in the combination again. If the storage unit prohibited from participating in the combination participates in the optimum combination, the object to be weighed is discharged. As a result, the storage unit once the combination prohibition flag is turned on can be restored, and it is expected that the stability of the operation is improved. Alternatively, in the second combination calculation, both the case where the storage unit with the combination prohibition flag set to ON is allowed to participate in the combination and the case where it is not allowed to participate may be tried. For the same reason, a forced combination may be tried in the first combination calculation (step S15) in the next and subsequent weighing cycles. Note that, from the viewpoint of increasing the number of combinations in the forced combination calculation, it is desirable that the storage unit prohibited from participating in the combination is not allowed to participate in the second combination calculation. This is because the more storage units that are forced to participate in the second combination calculation, the smaller the number of combinations.

  In the present embodiment, in determining which storage unit is erroneously supplied, the case where erroneous supply is simultaneously generated in both storage units is not specified. Here, the difference between the result of the recalculation and the stored measurement value may be compared with the measurement hopper holding amount fluctuation amount (αi: step S37). As a result, if the difference between the result of recalculation and the stored measurement value is not zero and the two are different, it can be determined that an erroneous supply has occurred in both storage units. On the other hand, if both are equal, it can be determined that an erroneous supply has occurred only in the storage section that has not been discharged.

  The supply hopper may be an apparatus having any configuration as long as it can individually supply the objects to be weighed to each of the plurality of storage units included in the weighing hopper.

The discharge conditions may be different in each step. That is, the discharge condition when selecting the optimum combination in step S15, the discharge condition in step S42, and the discharge condition in step S45 may be the same or different.
[Definition of terms]
The “discharge condition” refers to a condition for determining whether or not the object to be weighed can be discharged based on a specific combination. For example, the discharge condition can be whether the combination target weight is within a range having a lower limit and a value obtained by adding a certain threshold to the combination target weight.

  The “weighing value” is an element used for the combination calculation, and in the present invention, the weight of the object to be weighed respectively held by the storage portion of the weighing hopper is the weighing value.

  “Combination total weight” refers to the total of the measured values of the storage units participating in the combination when a combination in which one or a plurality of storage units are extracted from all candidate storage units is created.

  “Combination target weight” refers to the weight targeted by the combination weigher.

  The “optimal combination” refers to a combination of storage units that are scheduled to be discharged. For example, a combination that has a combined total weight within an allowable range determined based on the combination target weight and that is closest to the combination target weight can be determined as the optimum combination. For storage units that participate in the optimal combination, the measurement target is discharged if the total weight (measurement value) of the measurement items held by the storage unit satisfies the discharge condition.

  “Control device” refers to general means for controlling a gate, a feeder, etc. of a combination weigher. For example, even if the CPU and memory are combined and operated according to a software program, as in the control device 14 of the first embodiment. The logic circuit may be a combination of logic elements for performing control. A single control device may perform centralized control, or a plurality of control devices may perform distributed control.

  “Output device” generally refers to a device that can output a wide range, for example, an input / output device such as a touch panel, an electronic display device such as a display, or a printing device such as a printer. It may be a device.

  “Gate” generally refers to an apparatus for turning on / off the discharge of an object to be measured. For example, even if the discharge is turned on / off by opening / closing a door, the discharge is turned on / off by the presence or absence of vibration. It may be a thing.

  The combination weigher according to the present invention is a combination weigher in which the weighing hopper has a plurality of storage units, and the weighing object is erroneously supplied to the weighing hopper when it is not the timing to supply the weighing object. It is useful as a combination weigher capable of preventing a decrease in weighing accuracy.

It is a figure which shows a part of schematic structure when the combination balance of 1st Embodiment of this invention is cut | disconnected in the perpendicular direction. It is a block diagram which shows schematic structure of the control apparatus with which the combination weigher of 1st Embodiment of this invention is provided. It is a figure which shows an example of the operation program of the control apparatus in the combination scale of 1st Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feeding device 2 Level sensor 3 Top cone 4 Main feeder 5 Linear feeder pan 6 Linear feeder 7 Feeding hopper 9 Weighing hopper 9a, 9b Storage part 10a, 10b Gate 11 Collecting chute 12 Collecting funnel 13 Weight sensor 14 Control device 15 Input / output device Reference Signs List 16 arithmetic unit 17 storage unit 18 I / O circuit 19 A / D conversion circuit 20 gate drive circuit 21 vibration control circuit 22 timing unit

Claims (5)

A weighing hopper having a plurality of storage units for holding and discharging the objects to be weighed, a supply hopper for supplying the objects to be weighed to each of the storage units, and a weighing hopper holding which is the weight of the objects to be weighed held by the weighing hoppers A weight sensor for detecting the amount, and a control device;
The control device performs a first detection of detecting and storing a weighing hopper holding amount by the weight sensor when there is an empty storage unit,
After the first detection, the supply hopper is controlled to supply an object to be weighed to the empty storage unit,
After the supply, a second detection for detecting and storing the weighing hopper holding amount by the weight sensor is performed,
Based on the results of the first detection and the second detection, the weight of the object to be weighed supplied to the empty storage unit is calculated and stored as a measured value,
By performing a first combination calculation that is a combination calculation using the measured value, an optimal combination that is a combination of storage units to be discharged is selected,
When a predetermined condition is satisfied, a combination scale that discharges an object to be weighed from a selection storage unit that is a storage unit that participates in the optimal combination,
The control device detects and stores a weighing hopper holding amount of a selected weighing hopper, which is a weighing hopper having the selected accommodating portion, by the weight sensor before discharging the object to be weighed from the selected accommodating portion. Detection
For each of the selected weighing hoppers, the weighing hopper holding amount that is the difference between the weighing hopper holding amount stored when the weighing hopper becomes the selected weighing hopper and the weighing hopper holding amount obtained by the third detection Calculate the fluctuation amount,
In addition, the objects to be weighed are discharged from the storage units participating in the optimum combination based on whether or not the sum of the amount of change in the weighing hopper holding amount and the combined total weight of the optimum combination satisfies the discharge condition. A combination weigher that determines whether or not   When the sum does not satisfy the discharge condition, the control device sets the weighing hopper whose amount of variation in the holding amount of the weighing hopper exceeds a predetermined threshold as an abnormal weighing hopper, and the abnormal weighing hopper becomes the selected weighing hopper. When the second combination calculation is performed so that the weighing hopper holding amount of the abnormal weighing hopper stored at that time always participates in the combination, and the combination satisfying the discharge condition is obtained by the second combination calculation. The combination weigher according to claim 1, which updates the optimal combination.   The control device performs the first combination calculation again on condition that the storage unit of the abnormal weighing hopper is not allowed to participate in the combination when the combination satisfying the discharge condition is not obtained in the second combination calculation. The combination weigher according to claim 2, which is performed. Each of the weighing hoppers has two storage parts, and each of the supply hoppers has two gates for selectively supplying the objects to be weighed to the storage parts,
The control device performs a fourth detection by the weight sensor to detect a weighing hopper holding amount of an abnormal weighing hopper in which an object to be weighed is discharged only in a storage portion on one side,
The control device recalculates the measurement value of the storage unit on the side where the object to be weighed of the abnormal weighing hopper is not discharged based on the result of the fourth detection,
4. The supply hopper gate is determined to be defective based on a measured value obtained by the recalculation and a measured value obtained based on a result of the second detection. Combination weigher. Furthermore, an output device is provided,
The control device includes:
When it is determined that the objects to be weighed are not discharged from the storage units participating in the first optimal combination, and when there is no combination that satisfies the discharge condition in the second combination calculation,
Memorize and output the fact and the time when it occurred,
Store and output which weighing hopper is determined to be an abnormal weighing hopper,
Store and output the weighing hopper holding amount fluctuation amount of the abnormal weighing hopper,
5. The combination weigher according to claim 4, which stores and outputs which supply hopper gate is determined to have the defect.

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