JP2012063228A - Weighing system and combination balance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress reduction of combination accuracy as much as possible by performing zero-point correction only when required.SOLUTION: Whether zero-point correction of a weighing hopper is to be performed or not is determined based on a deviation between a combination weight value of an optimum combination weighing hopper weighed by a combination balance and a reweighed value of an object to be weighed reweighed by a weight selector to be a reweighing apparatus and discharged from the optimum combination weighing hopper, and when a plurality of determination results that zero-point correction is to be performed are obtained, a weighing hopper participating in the optimum combination weighing hoppers respectively corresponding to the plurality of determination results in common is specified as the weighing hopper to be subjected to the zero-point correction and zero-point correction of the specified weighing hopper is performed.

Description

  The present invention relates to a weighing system including a combination weigher and a reweighing device that reweighs a combination weighing value weighed by the combination weigher, and a combination weigher used in the weighing system.

  The combination weigher generally includes a plurality of weighing hoppers that weigh the supplied objects to be weighed, and various combinations of the weight values of the objects weighed by the plurality of weighing hoppers together with these combined weights (total Weight), for example, a combination calculation that selects a combination within a predetermined weight range closest to the target combination weight as the optimum combination is performed, and the object to be weighed is discharged from the weighing hopper of the selected optimum combination. For example, the weighing object is put into a packaging machine disposed below the combination weigher and packaged.

  In such a combination weigher, a zero point abnormality of the weighing hopper occurs during use, and the combined weight of the objects to be weighed discharged from the combination weigher may deviate from an allowable value. For this reason, the zero correction of the weighing hopper is performed (see, for example, Patent Document 1).

Japanese Patent Publication No. 61-12523

  In general, in combination weighers, the zero point of all weighing hoppers is automatically and sequentially corrected at regular intervals or every certain number of weighings. To perform zero point correction during operation, the weighing hopper that performs zero point correction is used. Does not supply an object to be weighed and must remain empty for a certain period. Accordingly, the weighing hopper cannot participate in the combination calculation during that time, and there is a problem that the number of combinations decreases and the combination accuracy decreases.

  The present invention has been made in view of the above-described problems. The zero point correction is not performed every fixed period or every fixed number of times of measurement, but is performed when necessary to reduce the combination accuracy. The purpose is to suppress as much as possible.

  In order to achieve the above object, the present invention is configured as follows.

(1) The weighing system of the present invention has a plurality of weighing units for weighing the objects to be weighed, and the combination of the weighing units satisfying the discharge condition when the combination weighing value obtained by variously combining the weighing values of each weighing unit satisfies the discharge condition. A combination weigher that selects as a combination and discharges the objects to be weighed of the selected weighing unit of the optimum combination; and a reweighing device that reweighs the objects to be weighed discharged from the weighing unit of the optimum combination of the combination weigher; A weighing system comprising:
Based on the combination weighing value of the weighing unit of the optimum combination weighed by the combination weigher and the reweighing value of the object to be weighed discharged from the weighing unit of the optimum combination and reweighed by the reweighing device Determining means for determining whether or not to perform zero correction of the measuring unit;
When the determination result that the zero point correction should be performed by the determination means is obtained a plurality of times, the measurement unit of the optimum combination corresponding to each of the determination results of the plurality of times participates in common. And a specifying means for specifying the weighing unit as a weighing unit to be zero-corrected,
The zero point correction of the measuring unit specified by the specifying means is performed.

  The weighing unit may be anything that can hold and weigh an object to be weighed.

  The discharge condition is a condition for discharging the object to be weighed from the combination weigher. The discharge condition is a condition for the combination to be established, for example, a combination measurement value obtained by variously combining the measurement values of each measurement unit. It may be a condition that it is within an allowable range determined based on a measurement value, or may be a condition that, in addition to the above condition, the combination measurement value is closest to the combination target measurement value. This discharge condition can be set by the operator.

  When weighing is performed normally by multiple weighing units of the combination weigher and re-weighing is performed normally by the reweighing device, the combination weighing value obtained by combining the weighing values of the weighing unit selected as the optimum combination and the optimum combination The re-weighed value obtained by re-weighing the object to be weighed from the weighing unit with the re-weighing device is almost the same, but if a zero point abnormality occurs, the combination weighing value and the re-weighing value There is a gap between them. The determination means determines whether or not zero correction is necessary based on the combination weighing value and the reweighing value. The determination means may determine whether or not zero correction is necessary based on a difference between the combination weighing value and the reweighing value, a ratio between the combination weighing value and the reweighing value, or the like.

  In the determination means, when the difference between the combination weighing value and the reweighing value becomes large, the zero point correction should be performed on the assumption that there are weighing units that should perform zero point correction in the plurality of weighing units of the combination weigher. judge.

  In the specifying unit, when the determination unit obtains the determination result that the zero correction of the weighing unit should be performed a plurality of times, each of the plurality of determination results is obtained for each optimum combination weighing unit. Among them, the measuring unit that participates in common is specified as the measuring unit that should be zero-corrected.

  The multiple times may be at least twice.

  According to the weighing system of the present invention, based on the combination weighing value of the weighing unit of the optimum combination by the combination weigher and the reweighing value of the object discharged from the weighing unit of the optimum combination and reweighed by the reweighing device. Determining whether or not the zero correction of the measuring unit is necessary, and when the determination result that the zero correction of the measuring unit is necessary is obtained a plurality of times, the weighing of the optimum combination corresponding to each of the plurality of determination results Since the weighing unit that participates in the unit is the weighing unit that needs zero correction, the zero point correction of the weighing unit is performed. Compared to the conventional example in which zero correction is automatically performed sequentially, zero correction is unnecessary, zero correction can be performed when necessary, and zero correction is performed sequentially for all measuring units. Rather than special Only it is possible to perform zero-point correction for metering unit which is. Thereby, it is possible to suppress as much as possible a reduction in combination accuracy due to the zero point correction.

  (2) In a preferred embodiment of the weighing system of the present invention, the object to be weighed is disposed between the combination weigher and the reweighing device and is discharged from the weighing unit of the optimum combination of the combination weigher. The reweighing device reweighs the object to be weighed packed by the packaging machine, and the determination means includes the combination weighing value of the weighing unit of the optimum combination. And the re-measurement value of the object to be weighed discharged from the weighing unit of the optimum combination is compared with a predetermined threshold value to make the determination.

  The predetermined threshold value may be one or plural. This threshold is preferably set in advance.

  In the determination means, for example, the absolute value of the difference between the combination weighing value of the weighing unit of the optimum combination and the reweighing value of the object to be weighed discharged from the weighing unit of the optimum combination is compared with a predetermined threshold value. Then, when the absolute value of the difference is larger than the predetermined threshold value, it may be determined that the zero point correction of the measuring unit should be performed.

  According to this embodiment, the weight of the packaged product packaged with the packaging material is weighed by the reweighing device, and the measured object discharged from the weighing unit of the optimum combination is reweighed by subtracting the known weight of the packaging material. The necessity of zero point correction can be determined by comparing the difference between the reweighing value and the combination weighing value of the optimum combination obtained by the combination weigher with a predetermined threshold value.

  (3) In another preferred embodiment of the measuring system according to the present invention, span calibration is performed for the measuring unit whose number of times specified as the measuring unit to be zero-corrected by the specifying unit is a predetermined number. Instruction means for instructing is provided.

  The instruction means may indicate the display, printing, voice, or a combination thereof.

  According to this embodiment, even after the zero point correction is specified by the specifying unit and the zero point correction is performed, the zero point correction is performed only when the zero point correction is repeatedly specified. Therefore, it is possible to instruct the span calibration to be performed because the deviation of the measurement value of the measurement unit cannot be corrected.

  (4) In another embodiment of the weighing system according to the present invention, when the determination means that the determination means that the zero point correction of the measuring section should be corrected continues more than a predetermined number of times, the re-weighing device It is instructed to perform zero point correction.

  According to this embodiment, when the determination result that the zero point correction of the weighing unit of the combination weigher should be corrected is continuously obtained a predetermined number of times or more, the reweighing by the reweighing device is performed instead of the combination weighing value by the combination weigher. Since there is a high possibility that an error has occurred in the value, in such a case, it is possible to instruct the reweighing device to perform zero point correction.

  As another embodiment of the present invention, after the zero point correction of the reweighing device is performed, and the determination result that the zero point correction of the weighing unit of the combination weigher should be continuously obtained a predetermined number of times or more Since the error of the reweighing value cannot be eliminated by the zero point correction, the recalibration apparatus may be instructed to perform the span calibration.

  (5) The weighing system of the present invention includes a weighing unit that has performed zero point correction, a number of times that zero point correction has been performed, a weighing unit that has performed span calibration, and an output unit that outputs the number of times that span calibration has been performed. .

  The output means may display, print, sound, or a combination thereof. It is also preferable to output the date and time when zero correction and span calibration were performed.

  According to this embodiment, since the weighing unit that has performed zero point correction and span calibration and the number of times thereof are output, it is possible to grasp the replacement timing of the weight sensor or the like constituting the weighing unit.

(6) The combination weigher of the present invention has a plurality of weighing units for weighing the objects to be weighed, and an optimum combination of weighing units satisfying the discharge conditions when the combination weighing values obtained by variously combining the weighing values of the respective weighing units satisfy the discharge conditions. A combination weigher that selects as a combination and discharges an object to be weighed in the weighing unit of the selected optimal combination,
Weighing based on the combination weighing value of the weighing unit of the optimum combination weighed by the combination weigher and the reweighing value by the reweighing device that reweighs the objects to be weighed discharged from the weighing unit of the optimum combination. Determining means for determining whether or not to perform zero correction of the part;
When the determination result that the zero point correction should be performed by the determination means is obtained a plurality of times, the measurement unit of the optimum combination corresponding to each of the determination results of the plurality of times participates in common. And a specifying means for specifying the weighing unit as a weighing unit to be zero-corrected,
The zero point correction of the measuring unit specified by the specifying means is performed.

  According to the combination weigher of the present invention, the weighing unit is based on the combination weighing value of the weighing unit of the optimum combination by the combination weigher and the reweighing value of the object to be weighed discharged from the weighing unit of the optimum combination by the reweighing device. When the determination result that the zero correction of the weighing unit is necessary is obtained a plurality of times, the weighing unit of the optimum combination corresponding to each of the plurality of determination results is included in the weighing unit. Since the measuring unit that participates in common is assumed to be a measuring unit that requires zero correction, the measuring unit is corrected to zero. Compared to the conventional example, which is automatically performed, zero correction can be performed when necessary without unnecessary zero correction, and the zero point correction is not performed sequentially for all measuring units. For the weighing unit Only it is possible to perform zero-point correction. Thereby, it is possible to suppress as much as possible a reduction in combination accuracy due to the zero point correction.

  According to the present invention, based on the combination weighing value by the combination weigher and the reweighing value by the reweighing device, it is determined whether the zero correction of the weighing unit is necessary, and the determination result that the zero correction of the weighing unit is necessary is obtained. If it is obtained a plurality of times, the weighing unit that participates in common among the weighing units of the optimum combination corresponding to the determination results of the plurality of times is regarded as a weighing unit requiring zero point correction. Because zero correction is performed, zero correction can be performed for the necessary measuring unit when necessary without unnecessary zero correction, and the reduction in combination accuracy due to zero correction is suppressed as much as possible. can do.

FIG. 1 is a diagram showing a configuration of a weighing system according to one embodiment of the present invention. FIG. 2 is a diagram showing a part of a data table stored in the control device of the combination weigher of FIG. 1 and a part of reweighing data transmitted from the weight sorter. FIG. 3 is a diagram showing a part of a data table processed and stored by the control device of the combination weigher of FIG. FIG. 4 is a flowchart for explaining the overall processing of the combination weigher of FIG. FIG. 5 is a flowchart for explaining processing such as zero correction of the combination weigher of FIG. FIG. 6 is a diagram showing an example of a display screen of the history of zero correction and span calibration. FIG. 7 is a diagram showing a configuration for instructing zero point correction of the weight sorter.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a schematic configuration of a weighing system according to one embodiment of the present invention.

  The weighing system 1 of this embodiment performs a combination calculation so that an object to be weighed (not shown) such as candy and snacks supplied from the supply device 2 is within a predetermined weight range which is a discharge condition, and performs a predetermined weight. A combination weigher 3 that discharges the objects to be weighed in the optimum combination within the range, a packaging machine 4 that wraps the objects to be weighed discharged from the combination weigher 3 with a packaging material, and conveying conveyors 5 and 6 from the packaging machine 4 And a weight sorter 7 as a re-weighing device that sorts whether the weight of the packaged product being conveyed is within the allowable weight range. The packaged product sorted by the weight sorter 7 is conveyed to a sorting device (not shown) via the conveyor 8 and the packaged product not within the allowable weight range is excluded from the production line as a defective product, while the allowable weight The packaged product within the range is packed as a good product by a subsequent boxing device (not shown).

  The combination weigher 3 is provided with a setting indicator 19, and this setting indicator 19 can be used to set and input operating conditions of the combination weigher 3, conditions for combination calculation, etc., and a function for displaying measurement results and the like. have. The setting indicator 19 can communicate with the control device 16 inside the combination balance 3 wirelessly or by wire, and in this embodiment, is configured by a touch panel.

  In the combination weigher 3, an object to be weighed is supplied from the supply device 2 to the central part of the dispersion feeder 9, and the object to be weighed is sent out in the direction of the peripheral edge by the vibration in the dispersion feeder 9. A plurality of, for example, 10 linear feeders 10 are conveyed. Each linear feeder 10 is provided with a vibration device, and each linear feeder 10 is vibrated to convey an object to be weighed and put into ten supply hoppers 11 installed radially around the linear feeder 10. To do. Each supply hopper 11 temporarily holds an object to be weighed, opens an openable / closable discharge gate 12 at the bottom, and places an object to be weighed in each weighing hopper 13 disposed below each supply hopper 11. throw into. The weighing hopper 13 has a discharge gate 15 that can be opened and closed at the bottom, and receives an object to be weighed from the supply hopper 11 with the discharge gate 15 closed. In each weighing hopper 13, the weight of the object to be weighed is weighed by a plurality of weight sensors 14 arranged inside the combination weigher 3.

  The detection output of each weight sensor 14 is given to a control device 16 disposed inside the combination scale 3, and the control device 16 performs a combination calculation based on the weight value of each weight sensor 14, whereby the combined weight is The combination of the weighing hoppers 13 that is within the predetermined weight range and matches or is closest to the combination target weight is selected as the optimal combination that satisfies the discharge condition, and the discharge gate 15 of the selected weighing hopper 13 of the optimal combination is opened. Then, the objects to be weighed are discharged, and are put into the packaging machine 4 through the collecting chute 17 and the charging chute 18.

  The control device 16 includes, for example, a microcomputer, performs the above-described combination calculation, and controls the feeders 9 and 10 and the hoppers 11 and 13 based on the setting operation of the setting indicator 19 described above. . Further, the re-weighing result data is given to the control device 16 from the weight sorter 7, and the control device 16 performs determination means for determining necessity of zero correction, zero correction, etc. as will be described later. It has a function as a specifying means for specifying the power weighing hopper 13.

  The packaging machine 4 is disposed below the combination weigher 3 and receives an object to be weighed discharged from the weighing hopper 13 of the optimum combination of the combination weigher 3 and wraps the object to be weighed with a packaging material such as a packaging bag. And discharged to the conveyor 5.

  The weight sorter 7 measures the package conveyed by the conveyors 5 and 6 from the packaging machine 4 and whether or not the weight of the package measured by the conveyor 20 is within the allowable weight range. A weight sorter main body 21 for performing such sorting and a setting display unit 22 are provided.

  The weight sorter 7 actually measures the weight of the entire packaged product including the objects to be weighed and the packaging material. However, since the weight of the packaging material is a known constant weight, packaging is performed from the weight of the entire packaged product. By subtracting the weight of the material, the weight of the object to be weighed can be re-weighed.

  The combination weigher 3, the packaging machine 4 and the weight sorter 7 are connected so as to be able to communicate with each other. The packaging machine 4 transmits to the combination weigher 3 a discharge command signal for the optimal combination of objects to be weighed in a predetermined weight range, and the combination weigher 3 responds to this discharge command signal to determine the optimal combination. The objects to be weighed are discharged from the weighing hopper 13 to the packaging machine 4 via the collecting chute 17 and a discharge completion signal is transmitted to the packaging machine 4. The packaging machine 4 receives the discharge completion signal and packages the objects to be weighed with the packaging material.

  Re-weighing result data is transmitted from the weight sorter 7 to the combination weigher 3. In other words, the combination weigher 3 can obtain from the weight sorter 7 data related to the re-weighing value of the weight of the objects to be weighed discharged from the combination weigher 3.

  In this embodiment, the zero point correction of all the weighing hoppers 13 is not sequentially performed every predetermined period or every predetermined number of times as in the conventional example, but the zero point correction can be performed for the necessary weighing hoppers when necessary. Thus, a reduction in combination accuracy due to the weighing hopper 13 that performs zero point correction being unable to participate in the combination calculation is suppressed as much as possible.

  That is, in the control device 16 of the combination weigher 3, the combination weight value of the weighing hopper 13 of the optimum combination satisfying the discharge condition by performing the combination calculation and the packaged product in which the objects to be weighed corresponding to the combination weight value are packaged are weighted. Based on the re-weight value re-weighed by the sorter 7, it is determined whether or not zero correction should be performed. When the determination result indicating that zero correction should be performed is obtained a plurality of times, the optimum combination of each time The weighing hopper 13 that participated in the weighing hopper 13 in common is identified as the weighing hopper 13 to be zero-corrected, and the zero-point correction is performed for the identified weighing hopper 13.

  FIG. 2 shows that when a combination operation is performed in the combination weigher 3, a part of the data table stored in the storage unit of the control device 16 and the weight sorter 7 are re-weighed to the combination weigher 3. It is a figure which shows a part of re-weighing data transmitted.

  In the combination weigher 3, the number of times of weighing, which is the number of times the combination is established and the object to be weighed, the combination weight value of the weighing hopper of the optimum combination at that time, and the hopper number of the weighing hopper participating in the optimum combination are Stored in the data table. From the weight sorter 7, the number of times of reweighing of the objects to be weighed discharged from the combination weigher 3 and the reweighed weight at that time are transmitted to the combination weigher 3. The combination weight of the combination weigher 3 and the re-weighing weight of the weight sorter 7 with the same number of times of measurement indicate the results of weighing the same object by the combination weigher 3 and the weight sorter 7, respectively.

  In the weight sorter 7, the objects to be weighed discharged from the weighing hopper 13 of the optimum combination that has been combined in the combination weigher 3 are packaged by the packaging machine 4 and further conveyed to the weighing conveyor 20 by the conveyors 5 and 6. Since the reweighed weight is transmitted to the combination weigher 3, the time until the reweighed weight of the corresponding object is obtained after the combination weight is weighed by the combination weigher 3 is measured. In the meantime, for example, the next several times of objects to be weighed for packaging are discharged from the combination scale 3.

  In FIG. 2, for example, when the number of times of weighing of the combination weigher 3 is 21, the combination weight value of the weighing hopper 13 of the optimum combination is 100.3 g, and the weighing hopper 13 that has participated in the optimum combination has the hopper number 3, 4, 6, and 10 weighing hoppers 13. Similarly, for example, when the combination weigher 3 is weighed 22 times, the combination weight value of the weighing hopper of the optimum combination is 100.1 g, and the weighing hopper 13 participating in the optimum combination has a hopper number of 2 This indicates that the weighing hoppers 13 are No. 5, No. 7, and No. 9.

  As described above, in the combination weigher 3, the combination weight value of the weighing hopper 13 of the optimum combination and the hopper number of the weighing hopper 13 participating in the optimum combination are stored as a data table for each weighing, and the weight selection is performed. Each time re-weighing is performed by the machine 7, the number of times of weighing and the re-weighing weight are transmitted to the combination scale 3.

  The control device 16 of the combination weigher 3 calculates the deviation based on the number of measurements from the weight sorter 7 and the re-weighed weight, and stores it as a data table shown in FIG.

  In the data table of FIG. 3, the number of times of weighing in the combination weigher 3 and the number of times of weighing in the weight sorter 7 are associated with each other so that the same weighing result of the object to be weighed is obtained. The deviation from the reweighed weight by the machine 7 is calculated as deviation = reweighed weight−combined weight−packaging material (2 g).

  In FIG. 3, for example, the deviation between the measurement number 21 and the measurement number 23 is large as “0.9” and “1.1”, and the measurement hopper 13 with the hopper number 4 is the measurement number 21. It participates in common as the weighing hopper of the optimum combination of the second time and as the weighing hopper 13 of the optimum combination of the number of times of weighing 23 times. That is, in the combination weight of the optimum combination in which the weighing hopper 13 with the hopper number 4 participates, the deviation is large.

  Therefore, the control device 16 determines that the zero correction of the weighing hopper 13 with the hopper number 4 is necessary, and as shown in FIG. 3, the weighing object is discharged from the weighing hopper 13 and becomes empty. In the 28th measurement, the zero correction of the weighing hopper 13 with the hopper number 4 is performed.

  Zero point correction prohibits the input of the object to be weighed into the weighing hopper 13 for which zero point correction is to be performed, and after the object to be weighed is discharged from the weighing hopper 13 and a stable time has passed, the weighing is performed and the measured value is obtained. Is the new zero.

  FIG. 4 is a flowchart for explaining the overall operation of the combination weigher 3.

  First, the control device 16 of the combination weigher 3 controls the dispersion feeder 9 to disperse the object to be weighed and supply it to the linear feeder 10 (Step S1), and further controls the linear feeder 10 to measure the object to be weighed. Is supplied to the empty supply hopper 11 (step S2).

  The control device 16 controls the discharge gate 12 of the supply hopper 11, opens the discharge gate 12 of the supply hopper 11 corresponding to the empty weighing hopper 13, and transfers the object to be weighed to the empty weighing hopper 13. Supply (step S3).

  When an object to be weighed is thus supplied to the empty weighing hopper 13, the weight of the object to be weighed supplied to the weighing hopper 13 is measured by the corresponding weight sensor 14, and the control device 16 supplies the weighing hopper 13 to the weighing hopper 13. Based on the weight of the object to be weighed, combination calculation is performed, and weighing control for selecting the optimum combination weighing hopper 13 that satisfies the discharge condition is performed (step S4). Thereafter, it is determined whether or not a discharge command signal is input from the packaging machine 4 (step S5). When the discharge command signal is input, the control device 16 causes the weighing hopper 13 that has participated in the combination weight and the optimal combination thereof. The hopper number is stored (step S6), a command is given to the weighing hopper 13 of the optimum combination to discharge the object to be weighed (step S7), and the process returns to step S1. Thereafter, by repeating the same weighing cycle as described above, an object to be weighed in an amount satisfying the discharge condition is discharged to the packaging machine 4.

  FIG. 5 is a flowchart for explaining processing for performing zero point correction and the like, and this processing is executed at regular intervals.

  First, the control unit 16 of the combination weigher 3 determines whether or not there is re-weighing data communication from the weight sorter 7 (step S10). The absolute value of the difference obtained by subtracting the known weight Pw of the packaging material from the re-weighed weight Cw of the packaged product and the combined weight Kw by the combination weigher 3 is calculated as a deviation H (= | Cw−Pw−Kw |) (step S11). ) And stored as the data table of FIG. 3 described above (step S12).

  Next, it is determined whether or not the deviation H is equal to or smaller than a first allowable value as a predetermined first threshold (step S13). When the deviation H is equal to or smaller than the first allowable value, It is not necessary to correct the zero point of the weighing hopper 13, and the process ends as normal. In step S13, when the deviation H is not less than or equal to the first tolerance value, it is determined whether or not it is less than or equal to a second tolerance value as a predetermined second threshold value (step S14).

  Here, the first and second tolerance values can be determined experimentally or empirically according to the type of the object to be weighed, and these tolerance values are set in advance by operating the setting indicator 19. be able to. In this embodiment, the first allowable value is 0.5 g, for example, and the second allowable value is 1.5 g, for example.

  In step S14, when the deviation H is greater than the first tolerance and less than or equal to the second tolerance, it is determined that zero correction is necessary, and the weighing hoppers 13 participating in the optimum combination at that time are determined. And before that, it is determined whether there is a weighing hopper 13 common to the weighing hoppers 13 participating in the optimum combination whose deviation H is also larger than the first tolerance and less than or equal to the second tolerance. (Step S15). That is, it is determined whether or not the optimum combination for which the deviation H is greater than the first allowable value and equal to or less than the second allowable value and should be zero-corrected is obtained a plurality of times. If there is a weighing hopper 13 that participates in common among the weighing hoppers 13 of the plurality of optimum combinations, it is determined.

  If there is no common weighing hopper 13 in step S15, the process ends. If there is a common weighing hopper 13, the weighing hopper 13 is specified as the weighing hopper 13 to be zero-corrected, and the zero-point correction control flag is set ( In step S16), the supply of the object to be weighed by the weighing hopper 13 is stopped, and the empty state is set to zero correction. That is, the measurement value of the measurement hopper 13 when stabilized in an empty state is set as a new zero point.

  Whether the frequency of the zero correction is high for the weighing hopper 13 that is specified as the weighing hopper 13 to be zero-corrected in step S16 and has the zero-point correction control flag set, for example, the zero-point correction control for the weighing hopper 13 until then. It is determined whether or not the sum of the number of times the flag has been set has reached a predetermined number (step S17). If the predetermined number has not been reached, that is, if the zero point correction frequency is not high, the process is terminated. When it reaches, that is, when the frequency of zero correction is high, the error cannot be resolved only by zero correction, and a message instructing that span calibration should be performed is displayed on the setting display 19 together with the hopper number of the weighing hopper 13 Then, the process ends (step S18). The operator appropriately performs span calibration of the designated weighing hopper 13 based on the instruction of the setting display unit 19.

  In step S14, when the deviation H is not less than or equal to the second allowable value, that is, when the deviation H is larger than the second allowable value, it is determined that zero correction is necessary, and participates in the optimum combination at that time. It is determined whether or not there is a weighing hopper 13 that is common to the weighing hopper 13 that is currently used and the weighing hopper 13 that is also participating in the optimum combination when the deviation H is larger than the second allowable value. (Step S19). That is, it is determined whether or not the optimum combination in which the deviation H is larger than the second allowable value and the zero point correction should be corrected is obtained a plurality of times. It is determined whether or not there are weighing hoppers 13 participating in common in the weighing hoppers 13.

  If there is no common weighing hopper 13 in step S19, the process ends. If there is a common weighing hopper 13, the weighing hopper 13 is specified as the weighing hopper 13 to be zero-corrected, and the zero-point correction control flag is set ( In step S20), the supply of the object to be weighed by the weighing hopper is stopped, and the zero state is corrected by making it empty.

  Further, for the weighing hopper in which the zero point correction control flag is set in step S20, the weighing hopper 13 on the setting display 19 is used to discharge an abnormal hopper, for example, an object to be weighed, whose deviation is larger than the second allowable value. It is determined that the hopper is an abnormal hopper such as a hopper bitten in the gate 15, a message to that effect is displayed to alert the operator (step S 21), and the process proceeds to step S 17.

  In this way, the deviation H is compared with the first and second tolerance values to determine whether or not to perform zero point correction, and when it is determined that zero point correction is to be performed, the same determination result is obtained multiple times. If it has been obtained, the weighing hoppers 13 participating in common among the weighing hoppers of the optimum combination of these multiple times are specified as the weighing hoppers 13 to be zero-corrected, and zero-point correction is performed.

  In addition, for the weighing hopper 13 that needs to repeatedly perform zero point correction, since the error cannot be eliminated only by zero point correction, the weighing hopper 13 is instructed to perform span calibration, so the operator needs to perform span calibration. Span calibration can be performed by recognizing the weighing hopper 13.

  Furthermore, in the case where the deviation H is larger than the second allowable value, for example, there is a possibility that it is an abnormal hopper such as a hopper that bites an object to be weighed into the discharge gate 15. A message can be displayed to alert the operator.

  As another embodiment of the present invention, the second tolerance value may be omitted.

  In this embodiment, the weighing hopper 13 that has been subjected to zero correction and the number of times thereof are stored, and the weighing hopper 13 that has been subjected to span calibration according to a span calibration instruction and the number of times thereof are stored.

  Therefore, for example, as shown in FIG. 6, the history of zero correction and span calibration can be displayed on the setting display 19 by operating the setting display 19.

  This zero point correction & span calibration history display screen 25 displays a period setting display area 26 for setting and displaying a period for displaying the history, and the hopper number, the number of zero point corrections and the number of span calibrations for each weighing hopper 13. And a display area 27. In the display example of the display area 27 in FIG. 6, for example, the weighing hopper 13 having the hopper number 1 indicates that zero point correction has been performed 21 times and span calibration has not been performed. The weighing hopper 13 with a hopper number of 6 indicates that zero point correction has been performed 40 times and span calibration has been performed 5 times.

  When a hopper number displayed in the display area 27 is touched, a history display pop small screen 28 showing a detailed history is displayed. In the display example of FIG. 6, when the hopper number 6 is touched, the display in the display area 27 of the weighing hopper 13 is reversed, and the detailed history of the weighing hopper 13 with the hopper number 6 is displayed in the history display pop small screen 28. Is displayed. In the history display pop small screen 28, the time when the zero correction of the weighing hopper 13 of the hopper number 6 is performed and the time when the span correction is performed are displayed. By touching the pop small screen display switching touch switches 29 and 30, the history display pop small screen 28 can be shifted to display previous and subsequent data. In addition, a touch switch 31 for returning the original display screen is provided.

  As described above, the setting display 19 outputs the weighing hopper 13 subjected to zero point correction and span calibration and the number of times thereof, and based on this, the replacement timing of the weight sensor 14 of the weighing hopper 13 is grasped. Can do.

  As another embodiment of the present invention, when the determination that the zero correction of the weighing hopper 13 should be performed can be obtained continuously and repeatedly, it is not the combined weight by the combination balance 3 but the weight sorter 7. Since there is a high possibility that an error occurs in the re-weighed weight due to the above, in such a case, as shown in FIG.

  The present invention is useful as a metering system.

1 Weighing System 3 Combination Weighing 4 Packaging Machine 7 Weight Sorter (Reweighing Device)
13 Weighing hopper 16 Control device

Claims (6)

A combination of weighing units having a plurality of weighing units for weighing the objects to be weighed, a combination of various weighing values of each weighing unit satisfying the discharge condition is selected as the optimum combination, and the selected optimum combination A weighing system comprising: a combination weigher for discharging the objects to be weighed in the weighing unit; and a reweighing device for reweighing the objects to be weighed discharged from the weighing unit in the optimum combination of the combination weighers
Based on the combination weighing value of the weighing unit of the optimum combination weighed by the combination weigher and the reweighing value of the object to be weighed discharged from the weighing unit of the optimum combination and reweighed by the reweighing device Determining means for determining whether or not to perform zero correction of the measuring unit;
When the determination result that the zero point correction should be performed by the determination means is obtained a plurality of times, the measurement unit of the optimum combination corresponding to each of the determination results of the plurality of times participates in common. And a specifying means for specifying the weighing unit as a weighing unit to be zero-corrected,
Performing zero correction of the measuring unit specified by the specifying means;
A weighing system characterized by that. A packaging machine that is disposed between the combination weigher and the reweighing device and wraps the objects to be weighed discharged from the weighing unit of the optimum combination of the combination weigher with a packaging material;
The reweighing device reweighs the object to be weighed packed by the packaging machine,
The determination means compares the difference between the combination weighing value of the weighing unit of the optimal combination and the re-weighing value of the object to be weighed discharged from the weighing unit of the optimal combination with a predetermined threshold value to determine the determination. I do,
The weighing system according to claim 1. Instructing means for instructing to perform span calibration with respect to the measuring unit whose number of times specified as the measuring unit to be zero-corrected by the specifying unit is a predetermined number of times,
The weighing system according to claim 1 or 2. The instructing means instructs the zero-correction of the re-weighing device when the determination result indicates that the zero-point correction of the weighing unit should be corrected a predetermined number of times or more;
The weighing system according to claim 3. A weighing unit that has performed zero point correction, a number of times that zero point correction has been performed, a weighing unit that has performed span calibration, and an output unit that outputs the number of times that span calibration has been performed.
The weighing system according to claim 3 or 4. A combination of weighing units having a plurality of weighing units for weighing the objects to be weighed, a combination of various weighing values of each weighing unit satisfying the discharge condition is selected as the optimum combination, and the selected optimum combination A combination scale for discharging the objects to be weighed in
Weighing based on the combination weighing value of the weighing unit of the optimum combination weighed by the combination weigher and the reweighing value by the reweighing device that reweighs the objects to be weighed discharged from the weighing unit of the optimum combination. Determining means for determining whether or not to perform zero correction of the part;
When the determination result that the zero point correction should be performed by the determination means is obtained a plurality of times, the measurement unit of the optimum combination corresponding to each of the determination results of the plurality of times participates in common. And a specifying means for specifying the weighing unit as a weighing unit to be zero-corrected,
Performing zero correction of the measuring unit specified by the specifying means;
A combination weigher characterized by that.

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