JP4554309B2 - Combination scale - Google Patents

Description

  The present invention relates to a combination weigher, and more particularly, to one that determines whether there is an abnormality in a weight signal to be combined.

  In general, a combination weigher, a combination of various weights of articles weighed by a plurality of weighing means, a combination which is equal to or close to a target weight is selected from these combinations, and the selected article is discharged from the weighing means It is. In such weighing means, when a failure occurs in the weighing means, it becomes impossible to select a combination that is exactly equal to or close to the target weight. As a technique for improving this point, for example, there is one disclosed in Patent Document 1.

  In this technique, after an article is supplied to a weighing hopper as a weighing means and the weighing is performed, the weighing value is compared with the weighing value of the article previously weighed by the weighing hopper, or another weighing hopper is used. It is determined whether or not there is an abnormality in the discharge mechanism of the articles from the weighing hopper, the supply mechanism of the articles to the weighing hopper, or the weighing mechanism.

JP 7-218328 A

  In this technique, it is determined whether or not there is an abnormality based on a measured value at a certain time when an article is supplied to the weighing hopper. However, in this case, if an abnormality occurs after the measurement value is acquired, the abnormality cannot be detected. Further, even when an abnormality occurs such that the measured value fluctuates over a certain period, this cannot be detected.

  An object of the present invention is to provide a combination weigher capable of detecting an abnormality in which a measured value fluctuates.

The combination weigher of one aspect of the present invention has a plurality of weighing means. These weighing means are capable of generating a weight signal representing the weight of the supplied article and discharging the article. As the weighing means, for example, an article accommodating means that contains an article and includes a discharging means that discharges the article, and a load detection means that is connected to the article accommodating means can be provided. The combination control means performs various combinations of the respective weight signals, and executes a combination calculation for selecting a combination in which the total weight is equal to or close to the target weight among these combinations. As a result of the combination calculation, the combination control means discharges the articles constituting the selected combination from the corresponding weighing means, and supplies the articles to the empty weighing means from the article supply means. This combination calculation, article discharge, and supply are repeated. In addition, the articles weighed by the weighing means are transferred to other article accommodating means, and the articles are newly supplied to the empty weighing means, and the articles of these other article accommodating means and the articles of the weighing means are targeted. Combination operations can also be performed. In addition, the discharge of the articles from the weighing means can be performed based on an article acceptance signal generated when the article acceptance means for accepting these discharged articles is acceptable. An abnormality determining means is provided for each of the weighing means. These abnormality determination means are the amount of variation that is the difference between the maximum value and the minimum value of the weight signal in the determination period after the weight signal of the corresponding weighing means is stabilized until the article of the corresponding weighing means is discharged. Is determined to be abnormal when is outside the allowable range. Based on the determination results of these abnormality determination means, the abnormality diagnosis means diagnoses whether or not there is an abnormality that causes a change with time of each measurement signal.

When disturbance occurs in the entire combination weigher, for example, when the power source used to operate the combination weigher fluctuates or noise is applied to this power source, the weight signals of all weighing means fluctuate. . Alternatively, when a disturbance is applied only to some weighing means, only the weight signals of some weighing means are changed. In addition, when abnormality occurs individually in the weighing means, fluctuation occurs regardless of the weight signal of other weighing means. Based on the fluctuations of these measurement signals, the determination results of the abnormality determination means are various. The abnormality diagnosis means diagnoses such a determination result and determines what abnormality has occurred.

For example, the abnormality diagnosis unit displays a disturbance abnormality display when the determination results of all of the abnormality determination units that have been determined immediately before the start of the abnormality diagnosis are abnormal. As described above, when a disturbance occurs in the entire combination weigher, the weight signal of each weighing means varies. Therefore, when the weight signal of each weighing unit is determined by the abnormality determination unit over a certain period, all the determination results of the abnormality determination unit that performed the determination during this period are abnormal. Therefore, when the determination results of all the abnormality determination means are abnormal, it is possible to notify that the combination weigher is affected by the disturbance by displaying the disturbance abnormality.

Alternatively, when the determination results of the plurality of abnormality determination means that have been determined most recently at the start of abnormality diagnosis are abnormal, the combination weigher is stopped and, for example, required for stabilization of the weight signal after the first predetermined time has elapsed. After the elapse of time, it is determined whether or not the variation amount of each weight signal is within an allowable range during a second predetermined time, and the combination weigher is operated when the variation amount of each weight signal is within the allowable range. You can resume. As described above, it is considered that the combination weigher is affected by disturbance if the determination results of all the abnormality determination means that have been determined most recently at the start of abnormality diagnosis are abnormal. Therefore, in order to determine whether or not this disturbance is temporary, the combination weigher is stopped, and each abnormality diagnosis is performed again after a lapse of the first predetermined time. At this time, if it is determined that there is no abnormality, the disturbance is temporary, so the operation of the combination weigher is resumed.

  Alternatively, in the second abnormality diagnosis, when the fluctuation amount of each weight signal is out of the allowable range, the disturbance is continuously generated, so the disturbance abnormality is displayed. As a result, it is possible to take measures for fundamentally removing the influence of disturbance.

The combination weigher according to another aspect of the present invention generates a weight signal representing the weight of a supplied article, and variously combines the plurality of weighing means capable of discharging the article and the respective weight signals. A combination operation for selecting a combination in which the total weight is equal to or close to the target weight is executed, the articles constituting the selected combination are discharged from the corresponding weighing means, and the emptying weighing means is supplied with the article supply means. A combination control unit that repeats the supply of articles from the weighing unit, and is provided for each of the weighing units, and after the weight signal of the corresponding weighing unit is stabilized, until the article of the corresponding weighing unit is discharged, A plurality of abnormality determination means for determining an abnormality when the fluctuation amount of the weight signal is outside an allowable range, and an abnormality that causes a change with time of each weight signal based on a determination result of the abnormality determination means An abnormality diagnosing means for diagnosing whether or not, and when the determination results of all the abnormality determining means that have been determined immediately before the abnormality diagnosis by the abnormality diagnosing means are abnormal, stop After the elapse of the predetermined time, it is determined whether the variation amount of each weight signal is within the allowable range during a second predetermined time, and the variation amount of each weight signal is within the allowable range. When the operation resumes.

The combination weigher according to another aspect of the present invention generates a weight signal representing the weight of a supplied article, and variously combines the plurality of weighing means capable of discharging the article, and the respective weight signals. A combination operation for selecting a combination in which the total weight is equal to or close to the target weight is executed, the articles constituting the selected combination are discharged from the corresponding weighing means, and the emptying weighing means is supplied with the article supply means. A combination control unit that repeats the supply of articles from the weighing unit, and is provided for each of the weighing units, and after the weight signal of the corresponding weighing unit is stabilized, until the article of the corresponding weighing unit is discharged, A plurality of abnormality determination means for determining an abnormality when the fluctuation amount of the weight signal is out of an allowable range, and an abnormality that causes a change with time of each weight signal based on a determination result of the abnormality determination means. An abnormality diagnosing unit for diagnosing whether or not, and when the determination results of the plurality of abnormality determining units that have been determined most recently at the time of the start of the abnormality diagnosis by the abnormality diagnosing unit are abnormal, After the predetermined time elapses, it is determined whether the variation amount of each weight signal is within the allowable range during a second predetermined time, and the variation amount of each weight signal is outside the allowable range. Sometimes the disturbance is displayed abnormally.

In each of the above aspects, each abnormality determination unit may be configured to determine when the determination period is equal to or longer than a predetermined time. In this case, the measurement signal of the measurement unit corresponding to the abnormality determination unit that has not been determined is excluded from the combination target.

  As described above, according to the present invention, when a change in the weight signal with time is caused, the change is caused in all the weighing means or in some of the weighing means provided in series. It is possible to determine what kind of abnormality has occurred in each measuring means by determining whether or not it has occurred independently.

  As shown in FIG. 1, the combination weigher according to an embodiment of the present invention has a plurality of weighing means, for example, a weighing instrument 2. These scales 2 are provided with an article storage section, for example, a weighing hopper 2a, and a load detection means, for example, a load cell 2b. ing. These measuring instruments 2 are arranged in an annular shape close to each other.

  Above these scales 2, supply means, for example, a supply hopper 4, is arranged. Although not shown, the supply hopper 4 is provided with discharge means, for example, a discharge gate. By operating the discharge means, articles in the supply hopper 4 are supplied to the corresponding weighing hopper 2. These supply hoppers 4 are also arranged in an annular shape.

  Articles are supplied to each supply hopper 4 from the upper part by a corresponding linear feeder 6. These linear feeders 6 are arranged radially from the center side of the above-described ring toward each supply hopper 4. By controlling the vibration of the centripetal feeder 6, the amount of articles supplied to the supply hopper 4 is controlled.

  Articles are supplied to the linear feeder 6 by the dispersion feeder 8 located at the center of the ring. That is, the articles are supplied to each linear feeder 6 by the turning of the dispersion feeder 8 about the vertical axis. The dispersion feeder 8 is a trough provided with an article supply device disposed above it, for example, a bucket lifter or a vibration device. The amount of articles supplied to the dispersion feeder 8 is controlled based on the layer thickness of the articles on the dispersion feeder 8 detected by the level detection device 12.

  Under each weighing hopper 2a, auxiliary article storage means, for example, a memory hopper 14, is arranged, and weighed articles are supplied from the corresponding weighing hopper 2a. Note that the discharge gate of each weighing hopper 2 a is configured to be able to discharge articles to the memory hopper 14 and to the collecting chute 16. Further, a discharge means such as a discharge gate is provided so that articles of the memory hopper 14 can also be discharged to the collecting chute 16. The articles discharged to the collecting chute 16 are supplied to an article receiving means (not shown) such as a packaging machine via a collecting funnel 18 provided below the collecting chute 16 and packaged there for another production line. It is conveyed to.

  The weighing instrument 2, the supply hopper 4, the rectilinear feeder 6, the dispersion feeder 8, the article supply device 10, and the memory hopper 14 are controlled by control means, for example, the control device 20.

  For example, it is assumed that articles are accommodated in each weighing hopper 2, each memory hopper 14, and each supply hopper 4, and articles are placed on the rectilinear feeder 6 and the dispersion feeder 8, respectively. Furthermore, it is assumed that weight signals indicating the weights of articles in each weighing hopper 2 and each memory hopper 14 are supplied to the control device 20.

  The control device 20 variously combines the respective weight signals, and the total weight of these combinations is equal to the target weight set in advance in the control device 20 or within the allowable weight range set for the target weight. The combination calculation for selecting the combination closest to the target weight is performed.

  The control device 20 discharges the articles to the collecting chute 16 from the weighing hopper 2a and the memory hopper 14 containing the articles corresponding to the weight signal selected by the combination calculation. This discharge is performed when a discharge instruction signal is sent from the packaging machine to the control device.

  The control device 20 sends the article from the weighing hopper 2a located above the memory hopper 14 from which the article has been discharged. Further, the control device 20 causes the weighing hopper 2a that has discharged the articles to the memory hopper 14 or the weighing hopper 2a that has discharged the articles to the collecting chute 16 to supply the articles from the supply hopper 4 above them. After the stabilization time required for the weight signal of the load cell 2b to stabilize has elapsed since the start of supply, the control device 20 takes in the stable weight signal. Then, the combination calculation is executed again. Thereafter, similarly, the discharge, supply, and combination calculation are repeated.

  On the other hand, the control device 20 causes the supply hopper 4 that has been emptied to supply articles from the corresponding linear feeder 6 and causes the dispersion feeder 8 to supply articles to each of the linear feeders 6. Further, when the level detector 12 detects that the number of articles on the dispersion feeder 8 has decreased, the control device 20 causes the supply device 10 to supply the articles to the dispersion feeder 8.

  The control device 20 further functions as an abnormality determination unit for each measuring instrument 2. This abnormality determination means is provided corresponding to each weighing instrument 20, and as shown in FIG. 2, after a stable time elapses after the article is supplied to the weighing instrument 2 until the weight signal is stabilized, the weighing is performed. The period until the article is discharged from the weighing hopper 2a of the container 2, for example, the determination period from when the combination calculation is finished until the discharge command is supplied from the packaging machine (however, the discharge after the combination calculation is completed) Determine whether or not the amount of change in weight signal (for example, the difference between the maximum value and the minimum value) is within a predetermined allowable range) However, when the above difference is outside the allowable range, it is determined that there is an abnormality.

  This determination period is shortened when the discharge command is output after a short time has elapsed since the combination calculation is completed as shown in the first half of FIG. 3, but the combination calculation is completed as shown in the second half of FIG. If the discharge command is output after a relatively long time has elapsed, the time becomes longer. FIG. 3 shows a discharge operation period of one weighing device 2, a supply operation period of the supply hopper 4 corresponding thereto, an operation period of the linear feeder 6, a period during which a combination calculation is performed, and a discharge command. This shows the relationship with the time point.

  For example, the flowchart shown in FIG. 4 shows an abnormality determination process executed by an arbitrary (n-th) measuring instrument 2 among the measuring instruments 2. This abnormality determination process is performed for any measuring instrument 2. In this process, first, it is determined whether or not an article has been put into the weighing hopper 2a of the nth weighing instrument 2 and weighing has been completed (step S2). For example, it is determined whether a predetermined time has elapsed after the combination calculation is completed. If the answer to this determination is no, the abnormality determination data loading flag corresponding to this measuring instrument 2 is turned off (step S4), and step S2 is repeated.

  If the answer to the determination in step S2 is yes, that is, if the weight signal can be captured, it is determined whether or not the abnormality determination data capturing flag is on (step S6). If the answer to this determination is no, the abnormality determination data fetching flag is turned on (step S8), the data used in the previous abnormality determination is cleared (step S10), and how many abnormality determinations have been made. The value of the update number representing “1” is incremented by one (step S12).

  Subsequent to step S12 or when the answer to the determination in step S8 is yes, that is, when the data for abnormality determination has already been taken in, the weight signal (measurement data) is read (step S14). Then, it is determined whether the read weighing data is larger than the maximum value so far (step S16). If the answer to this determination is yes, the weighing data is set as a new maximum value (step S18). If the answer to the determination in step S16 is no, it is determined whether the weighing data is smaller than the previous minimum value (step S20). If the answer to the determination is yes, the weighing data is set as a new minimum value ( Step S22). If the answer to the determination in step S20 is no, or following step S18 or S22, it is determined whether the difference between the maximum value and the minimum value is greater than a predetermined allowable value (step S24). If the answer to this determination is yes, an abnormality flag provided for the nth measuring instrument 2 is set (step S26), and the process is repeated from step S2. If the answer to the determination in step S24 is no, the process is repeated from step S2.

  FIG. 5 shows a table in the control device 20 that stores the result of the abnormality determination for each measuring instrument 2 as described above. Here, there is a difference in the update numbers in the measuring instrument 2 because the determination period continues until the article is discharged from the measuring instrument 2.

  The control device 20 also functions as an abnormality diagnosis processing means for diagnosing the contents of this table. For example, if the determination result of all the measuring instruments 20 determined in a certain determination period is abnormal, it is considered that the voltage of the power source supplied to the combination weigher is fluctuating or noise is added to the power source voltage. Therefore, as shown in FIG. 6, when a certain determination period ends, it is determined whether all the abnormality flags of the measuring instrument 2 having the latest update number (the most recently determined determination) are set (step S28). ). If the answer to this determination is yes, the combination weigher is temporarily stopped (step S30), the time required for the weight signal to stabilize is awaited (step S32), and the fluctuation of each weight signal within a predetermined time Is within an allowable range (step S34). That is, steps S14, S16, S18, S20, S22, S24, and S26 are repeated over a predetermined time. Next, it is determined whether there is any abnormality flag set in this determination (step S36). If the answer is yes, that is, if there is no abnormality in the weight signal of any measuring instrument 2, the power supply is temporarily turned on. It is determined that noise is on the voltage, and the operation of the combination weigher is resumed (step S38). If there is an abnormality in the weight signal of any of the measuring instruments 2, it is considered that noise is continuously on the power supply voltage or the power supply voltage fluctuates. Therefore, a warning display indicating that fact is displayed on a display device (not shown) attached to the control device 20 (step S40), and prompts to take a fundamental countermeasure.

  If the answer to the determination in step S28 is no, as shown in FIG. 7, as a result of the abnormality determination of the latest update number, it is determined whether there are a plurality of measuring instruments 2 in which the abnormality flag is set are in proximity. (Step S42). If the answer to this determination is yes, it is considered that the weight signal fluctuates due to wind hitting a plurality of measuring instruments 2 arranged close to each other among the measuring instruments 2 arranged in a circle. . Therefore, the wind warning is displayed on the display device described above (step S44).

  If the answer to the determination in step S42 is no, it is determined whether any abnormality determination result of the latest update number has an abnormality flag set (step S46). If the answer to this determination is yes, it is determined that an abnormality has occurred in the measuring instrument 2 alone, so that the measuring instrument 2 is displayed on the display device described above (step S48).

  Subsequent to step S48 or when the answer to the determination in step S46 is no, there is a measuring instrument 2 that has not been updated more than a predetermined number of times, that is, a measuring instrument 2 that has not been determined more than a predetermined number of times. It is determined whether it exists (step S50). This is whether or not there is a measuring instrument 2 that continues to discharge articles without a predetermined time for determination between when the combination calculation is performed and when a discharge command is given. Is determined. If the result of this determination is yes, such a measuring instrument 2 is excluded from the combination because the measuring instrument 2 has a period during which the determination is not substantially performed over a long period of time (step S52). As a result, the weight signal of the weighing instrument is also determined. When step S52 ends or when the answer to the determination in step S50 is no, the abnormality diagnosis process ends.

  In the above-described embodiment, the measuring instrument 2 is arranged in a circular shape, but the measuring instrument 2 is not limited to this. For example, the measuring instrument 2 may be arranged in a single line or a plurality of lines. In the above embodiment, the memory hopper 14 is provided, but it can be removed. Further, although the supply of the articles of the weighing hopper 2a is performed by the supply hopper 4, it can be performed directly from the linear feeder 6 or can be manually performed by an operator. Moreover, although the articles | goods discharged | emitted from the weighing hopper 2 or the memory hopper 14 were conveyed to the packaging machine via the collection chute 16 and the collection funnel 18, it can also be conveyed by conveyance means, such as a conveyor. In the above embodiment, the fluctuation of the weight signal due to the fluctuation of the power supply voltage or noise, the fluctuation of the weight signal due to the wind pressure, and the fluctuation of the weight signal due to the abnormality of the measuring instrument 2 alone are diagnosed. It is also possible to diagnose only one that can occur frequently.

It is a schematic block diagram of the combination weigher of one Embodiment of this invention. It is a figure which shows the time-dependent change of the weight signal of the measuring instrument used for the combination scale of FIG. It is a figure which shows the timing of 1 set of measuring instruments, supply hopper, linear feeder, combination calculation, and article discharge | emission in the combination weigher of FIG. It is a flowchart of the abnormality determination performed in the combination weigher of FIG. It is a figure which shows the table produced as a result of the abnormality determination of FIG. FIG. 6 is a flowchart of a part of abnormality diagnosis performed using the table of FIG. 5. It is a flowchart of the remaining part of the abnormality diagnosis performed using the table of FIG.

Explanation of symbols

2 Weighing instruments (measuring means)
4 Supply hopper (supply means)
20 Control device (control means, abnormality determination means, abnormality diagnosis means)

Claims (7)

A plurality of weighing means capable of generating a weight signal representative of the weight of the supplied article and capable of discharging the article;
Various combinations of the weight signals are performed, and a combination operation is performed to select a combination in which the total weight is equal to or close to the target weight, and the articles constituting the selected combination are discharged from the corresponding weighing means. Combination control means for repeatedly supplying articles from the article supply means to the empty weighing means;
The difference between the maximum value and the minimum value of the weight signal in the determination period provided for each weighing means and after the weight signal of the corresponding weighing means is stabilized until the article of the corresponding weighing means is discharged. A plurality of abnormality determining means for determining an abnormality when the fluctuation amount is outside the allowable range;
An abnormality diagnosis means for diagnosing whether or not there is an abnormality that causes a change with time of each weight signal based on the determination result of these abnormality determination means;
A combination weigher. 2. The combination weigher according to claim 1, wherein the abnormality diagnosing means displays a disturbance influence display when the determination results of all the abnormality determining means that have been determined most recently at the start of the abnormality diagnosis are abnormal. The combination weigher according to claim 1, wherein the operation is stopped when the determination results of all of the abnormality determination means that have been determined immediately before the abnormality diagnosis by the abnormality diagnosis means are abnormal, and the first predetermined time after the lapse of the variation amount of the respective weight signals during a second predetermined time is determined whether or not within the allowable range, the resume operation when in the variation amount the allowable range of the weight signal Combination weigher. 2. The combination weigher according to claim 1, wherein when the determination results of the plurality of abnormality determination means that have been determined most recently at the time of the start of abnormality diagnosis by the abnormality diagnosis means are abnormal, after a lapse of a first predetermined time the variation amount of the respective weight signals during a second predetermined time is determined whether or not within the allowable range, the fluctuation amount of each weight signal to a disturbance abnormality display when outside the allowable range Combination scale. A plurality of weighing means capable of generating a weight signal representative of the weight of the supplied article and capable of discharging the article;
Various combinations of the weight signals are performed, and a combination operation is performed to select a combination in which the total weight is equal to or close to the target weight, and the articles constituting the selected combination are discharged from the corresponding weighing means. Combination control means for repeatedly supplying articles from the article supply means to the empty weighing means;
Provided for each weighing means, after the weight signal of the corresponding weighing means is stabilized, the fluctuation amount of the weight signal is out of the allowable range during the determination period until the article of the corresponding weighing means is discharged. A plurality of anomaly judging means for judging when an anomaly;
An abnormality diagnosis means for diagnosing whether or not there is an abnormality that causes a change with time of each weight signal based on the determination result of these abnormality determination means;
And when the determination result of all of the abnormality determination means whose determination period has ended most recently at the start of abnormality diagnosis by the abnormality diagnosis means is abnormal, after the first predetermined time has elapsed, the second predetermined A combination weigher that determines whether or not the variation amount of each weight signal is within the allowable range over time, and resumes operation when the variation amount of each weight signal is within the allowable range . A plurality of weighing means capable of generating a weight signal representative of the weight of the supplied article and capable of discharging the article;
Various combinations of the weight signals are performed, and a combination operation is performed to select a combination in which the total weight is equal to or close to the target weight, and the articles constituting the selected combination are discharged from the corresponding weighing means. Combination control means for repeatedly supplying articles from the article supply means to the empty weighing means;
Provided for each weighing means, after the weight signal of the corresponding weighing means is stabilized, the fluctuation amount of the weight signal is out of the allowable range during the determination period until the article of the corresponding weighing means is discharged. A plurality of anomaly judging means for judging when an anomaly;
An abnormality diagnosis means for diagnosing whether or not there is an abnormality that causes a change with time of each weight signal based on the determination result of these abnormality determination means;
And when the determination results of the plurality of abnormality determination means that have been determined most recently at the time of the start of abnormality diagnosis by the abnormality diagnosis means are abnormal, the second predetermined time after the first predetermined time elapses A combination weigher that determines whether or not the variation amount of each weight signal is within the allowable range during the period, and displays a disturbance abnormality when the variation amount of each weight signal is outside the allowable range . The combination scale according to any one of claims 1 to 6, wherein each abnormality determination means is configured to determine when the determination period is equal to or longer than a predetermined time.
A combination weigher in which the weighing signal of the weighing unit corresponding to the abnormality determining unit that has not been determined is excluded from the combination target .

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