JP2012229977A - Combination balance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress reduction of combination accuracy due to reduction in the number of weighing hoppers disabled from participating in combination calculation.SOLUTION: A control device 9 determines whether or not weighing objects 20 are supplied from respective conveyance ends 6a to supply hoppers 12 based on detection outputs from a weighing object sensor 7 for respectively detecting the weighing objects 20 on respective conveyance ends 6a of respective linear feeder pans 6, and when determining that the supply hopper 12 to which no weighing object 20 is supplied is generated, a corresponding weighing hopper 13 under the supply hopper 12 discharge a weighing object 20 selected by combination calculation and zero point calculation of the weighing hopper 13 which is timing of zero point correction is performed. Consequently a frequency of performing zero point correction by forcedly prohibiting supply of the weighing object 20 from the supply hopper 12 to the weighing hopper 13 and generating an empty weighing hopper 13 can be reduced.

Description

  The present invention relates to a combination weigher for weighing an object to be weighed such as vegetables, fruits or confectionery, and more particularly to a combination weigher that automatically performs zero point correction during operation.

  Generally, objects to be weighed such as vegetables and fruits that have been weighed with a combination weigher to have a predetermined weight are packaged by a packaging machine, for example.

  FIG. 9 is a diagram schematically showing a schematic configuration of a conventional combination weigher of Patent Document 1. As shown in FIG.

  In this combination weigher, an object to be weighed is supplied from a supply device 30 to the central portion of a conical top cone 31a of a main feeder (dispersion feeder) 31, and the main feeder 31 feeds the object to be weighed toward the periphery by vibration. Then, it is conveyed to a plurality of tray-like linear feeders 32 that are radially installed around the main feeder 31.

  A vibration device is attached to the plurality of linear feeders 32, and each linear feeder 32 is vibrated to convey an object to be weighed and put into the plurality of supply hoppers 33. The plurality of supply hoppers 33 temporarily hold the objects to be weighed, open the charging gate 34, and load the objects to be weighed into the weighing hopper 35 as a weighing unit disposed below the supply hopper 33. In each weighing hopper 35, the weight of the object to be weighed is measured by the weight sensor 36, and a control unit (not shown) performs a combination operation based on the measured value, so that the total of the measured values matches the combined target weight. A combination of the weighing hoppers 35 of the closest predetermined weight range is obtained, the discharge gate 37 of the weighing hopper 35 selected by this combination is opened, the objects to be weighed are discharged, and the packaging machine 39 is connected via the collecting chute 38. And packaging with a packaging machine 39.

JP 62-1113024 A

  In the combination weigher, the output signal of the weight sensor for weighing an object to be weighed in the weighing hopper is subjected to processing such as amplification and A / D conversion in a signal processing circuit to obtain a weighing value. For example, a zero point drift (fluctuation) occurs due to a temperature change of the weight sensor itself, a temperature change of the signal processing circuit, or a residue of an object to be weighed attached to the weighing hopper, and appears as an error in the measured value.

  For this reason, it is necessary to periodically correct the zero point of the weighing hopper in order to ensure the accuracy of the measured value.

  When performing zero correction of a weighing hopper, the supply of the object to be weighed to the weighing hopper is prohibited by one weighing cycle, and the empty hopper is weighed to obtain a new zero. Perform zero point correction. This zero point correction is performed by sequentially setting the weighing hoppers one by one in an empty state.

  When such zero correction is performed, the weighing accuracy is improved, but the weighing hopper during the zero correction cannot participate in the combination calculation, and the number of weighing hoppers that can participate in the combination calculation decreases. To do.

  By the way, in a combination weigher, for example, in the case of manufacturing a packed product containing several pieces by weighing the objects to be weighed, such as peppers, with a large surface frictional resistance, supply from the main feeder to each linear feeder. If there is a stagnation or variation in the supply of the weighing object, the weighing object on the linear feeder becomes discontinuous, causing a state where the weighing object cannot be supplied to the supply hopper temporarily or periodically. The object to be weighed may not be put into the weighing hopper from the hopper.

  In this way, when there is an empty weighing hopper in which the object to be weighed does not enter, the timing of the zero point correction that is periodically performed overlaps, and an empty weighing hopper that does not inject the object to be weighed for the zero point correction If further added, the number of effective hoppers that can participate in the combination calculation is extremely reduced, the combination accuracy is lowered, and the yield is deteriorated.

  The present invention has been made in view of the above points, and an object of the present invention is to suppress a reduction in the combination accuracy due to a decrease in the number of measuring units that cannot participate in the combination calculation.

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

(1) The combination weigher of the present invention is arranged corresponding to each of the plurality of transport units for transporting the objects to be weighed and ejecting them from the transport end, and to be weighed being discharged from the transport end. A plurality of supply units that hold objects and supply the objects to be weighed downward, and are arranged corresponding to the respective supply units, hold the objects to be weighed supplied from each supply unit, and hold the objects A plurality of measuring units for measuring the weight of an object to be weighed, a zero point correction for the measuring unit, and a combination operation based on a measured value of the object to be weighed measured by the measuring unit, A combination weigher equipped with a calculation control unit that discharges an object to be weighed in the selected weighing unit,
A weighing object sensor for detecting a weighing object at each conveyance end of each conveyance unit and providing a detection output to the calculation control unit;
The arithmetic control unit controls the driving of the conveyance unit, and determines that the measurement object is not supplied from the conveyance end to the supply unit based on the detection output of the measurement object sensor. A weighing unit corresponding to the determined supply unit, which is selected as the appropriate amount combination, discharges an object to be weighed, and performs zero point correction on the weighing unit which is a timing at which zero point correction should be performed.

  Since the calculation control unit controls the driving of each conveyance unit and is provided with the detection output of the weighing object sensor that detects the measurement object at each conveyance end of each conveyance unit, for example, before driving the conveyance unit or During driving, the object to be weighed at the transport end is not detected by the object sensor, that is, when there is no object to be weighed at the transport end, the object to be weighed is supplied from the transport end to the supply unit even if the transport unit is driven. If the object to be weighed is detected by the object sensor before or during the driving of the transport unit, that is, when there is an object to be weighed at the transport end, By driving, it can be determined that the object to be weighed is supplied from the transport end to the supply unit.

  The measuring unit that is the timing at which zero correction should be performed refers to a measuring unit that has passed a predetermined time, which is a time interval for zero correction, or a measuring unit that has performed a predetermined number of times of measurement.

  If there is a stagnation or variation in the supply of the weighing object to the conveying unit that conveys the weighing object, the weighing object conveyed by the conveying unit becomes discontinuous, and the weighing object is temporarily or periodically transferred to the conveying end. Therefore, a state occurs in which the object to be weighed cannot be supplied from the transfer end to the supply unit.

  In this way, if the object to be weighed is not supplied from the transport end to the supply unit, the object to be weighed cannot be put into the corresponding weighing unit from the supply unit, and the weighing unit is selected as an appropriate amount combination by the combination calculation and is weighed. When the object is discharged, the measuring unit becomes empty.

  According to the present invention, the arithmetic control unit that controls the driving of each conveyance unit is configured to measure the objects to be weighed at each conveyance end based on the detection output of the object to be measured at each conveyance end of each conveyance unit. Therefore, if there is a supply unit that does not supply the object to be weighed, the weighing unit corresponding to the supply unit is selected as an appropriate combination by combination calculation. If the weighing unit is to discharge the object to be weighed and should perform the zero point correction, the zero point correction is performed for the weighing unit. In this way, when a supply unit to which an object to be weighed is not supplied and an empty measuring unit to which an object to be weighed is not supplied from the supply unit is generated, the zero point correction is performed with priority on the measurement unit, The number of empty measuring units that cannot participate in the combination calculation can be reduced by forcibly prohibiting the supply of objects to be weighed and reducing the frequency of zero correction by making the measuring unit empty. It can reduce and the fall of combination accuracy can be controlled.

  (2) In a preferred embodiment of the combination weigher of the present invention, when there is no supply unit that determines that the object to be weighed is not supplied, the arithmetic control unit selects the object to be weighed as the appropriate amount combination. The zero point correction is performed for the weighing unit which is the timing at which the discharge and the zero point correction should be performed.

  According to this embodiment, when there is no supply unit for which it is determined that the object to be weighed is not supplied, as in the conventional case, it is selected as an appropriate amount combination, the object to be weighed is discharged, and zero correction should be performed. The zero point correction can be performed for the measuring unit which is the timing.

  (3) In the embodiment of the above (2), when there are a plurality of weighing units that are selected as the appropriate amount combination, discharge the object to be weighed, and have a timing at which zero correction should be performed, Any one measuring unit may be selected to perform zero point correction.

  Any one of the weighing units is preferably selected in a predetermined order.

  In this embodiment, when zero correction is performed, since one weighing unit is selected, the number of weighing units that cannot participate in the combination calculation for zero correction can be limited to one, and the combination accuracy Can be suppressed.

  (4) In another embodiment of the combination weigher of the present invention, the plurality of transport units are a plurality of vibration feeders that transport the objects to be weighed by vibration, and the plurality of supply units are configured to hold the objects to be weighed. A plurality of supply hoppers for supplying to the weighing unit, the plurality of weighing units are a plurality of weighing hoppers for weighing the object to be weighed by a weight sensor, and the arithmetic control unit drives the vibration feeder. In addition to controlling, opening and closing of the gate for feeding the hopper and the gate for discharging the weighing hopper are controlled.

  According to this embodiment, the arithmetic control unit determines whether the object to be weighed at the conveyance end of the vibration feeder is supplied to the supply hopper by driving the vibration feeder based on the detection output of the object sensor. A weighing hopper corresponding to a supply hopper that is determined not to be supplied with an object to be weighed, is selected as an appropriate combination by combination calculation, discharges the object to be weighed, and timing for zero correction The zero point correction can be performed for the weighing hopper.

  (5) In the embodiment of the above (4), the calculation control unit prohibits opening / closing of the gate for feeding the supply hopper determined that the object to be weighed is not supplied, and the object to be weighed is not supplied. The weighing hopper corresponding to the supply hopper determined to be, may be selected as the appropriate amount combination to discharge the object to be weighed, and the zero point correction may be performed on the weighing hopper which is the timing at which the zero point correction should be performed. .

  According to this embodiment, the weighing object is supplied to the weighing hopper because it is prohibited to open and close the gate for supplying the weighing hopper that has been determined that the weighing object is not being supplied. Even if the object to be weighed is supplied to the supply hopper determined to be not, the object to be weighed will not be put into the corresponding weighing hopper. Can be done.

  According to the present invention, since there is a stagnation or variation in the supply of the weighing object to the conveying unit that conveys the weighing object, the weighing object is not conveyed to the conveying end of the conveying unit, and the weighing object is transferred from the conveying end. When a supply unit that is not supplied is generated, the weighing unit corresponding to the supply unit is selected by the combination calculation and discharges the object to be weighed. When there is a supply unit to which the object to be weighed is not supplied and an empty weighing unit from which the object to be weighed is not supplied from the supply unit, the zero point correction for the measurement unit is performed with priority. This forcibly prohibits the supply of objects to be weighed from the supply unit to the weighing unit, reduces the frequency of zero correction by leaving the weighing unit empty, and participates in combination calculations. Can There Reduce the number of metering portions of the empty, it is possible to suppress a decrease in combination accuracy.

FIG. 1 is a schematic diagram showing a schematic configuration of a combination weigher according to an embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of the combination weigher of FIG. FIG. 3 is a flowchart for explaining the operation of the combination weigher. FIG. 4 is a flowchart showing a zero point correction timing determination process. FIG. 5 is a flowchart showing details of the linear feeder control of FIG. FIG. 6 is a flowchart showing details of the supply hopper control of FIG. FIG. 7 is a flowchart showing details of the metering control of FIG. FIG. 8 is a flowchart showing details of the weighing hopper control of FIG. FIG. 9 is a schematic configuration diagram of a conventional combination weigher.

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

  FIG. 1 is a schematic diagram showing a schematic configuration of a combination weigher according to an embodiment of the present invention. The combination weigher of this embodiment has a conical top cone 3 that radially disperses the objects 20 to be weighed and dropped from the supply device 1 at the center of the upper portion of the device, and a main that vibrates the top cone 3. A feeder (distributed feeder) 4 is provided.

  The objects to be weighed 20 are not limited, but are, for example, vegetables such as peppers, tomatoes, potatoes, fruits such as oranges and apples, or relatively large “cracked rice cakes” that tend to rub and generate a large amount of residue (debris). ”And pillow-wrapped confectionery, etc., and is particularly suitable for producing net packages or the like containing several pieces by combination weighing.

  The supply device 1 conveys an object to be weighed 20 such as bell pepper supplied from a belt conveyor (not shown) by vibration and drops it to the center of the top cone 3 to supply. In the top cone 3, the object to be weighed 20 supplied from the supply device 1 to the central portion thereof is conveyed toward the peripheral portion by vibration. Around the top cone 3, a plurality of linear feeder pans 6 for conveying the objects 20 to be weighed sent from the top cone 3 to a plurality of supply hoppers 12 and a plurality of linear feeder pans 6 for vibrating the linear feeder pans 6. Feeders 8 are provided radially. A plurality of supply hoppers 12 serving as supply units are provided below the peripheral edge of the linear feeder pan 6, and a weighing hopper 13 serving as a weighing unit is provided below the supply hopper 12. It is arranged in a circle.

  Under the supply hopper 12 and the weighing hopper 13, a closing gate 12 a and a discharging gate 13 a that can be opened and closed are respectively provided. The supply hopper 12 receives the object 20 to be weighed 20 which is transported by the linear feeder pan 6 and dropped and discharged from the transport end 6a which is the front end thereof. 12a is opened, and the object 20 is dropped and discharged and put into the weighing hopper 13. Each weighing hopper 13 is connected to a weight sensor 10 such as a load cell for measuring the weight of the object 20 in the weighing hopper 13, and a measured value from each weight sensor 10 is output to the control device 9.

  The plurality of linear feeder pans 6 and the plurality of linear feeders 8 that respectively vibrate the respective linear feeder pans 6 constitute a plurality of transport units that transport the objects to be weighed 20 to the corresponding supply hoppers 12.

  The weighing hopper 13 can discharge the objects 20 to the collecting chute 14. When a combination of the weighing hoppers 13 from which the objects to be weighed 20 are to be discharged is obtained from the plurality of weighing hoppers 13 by the combination calculation by the control device 9, and a discharge request signal is input from the packaging machine 15, it corresponds to the combination. The objects 20 to be weighed are discharged from the weighing hopper 13 to the collecting chute 14 and further discharged to the lower packaging machine 15.

  In this embodiment, the amount of the weighing object 20 supplied from the supply device 1 to the top cone 3 is measured by the weight sensor 5 for the top cone supporting the top cone 3 and the main feeder 4, and the measured value is It is given to the control device 9. In the control device 9, based on the weight of the weighing object 20 on the top cone 3 measured by the top cone weight sensor 5, the amount of the weighing object 20 on the top cone 3 is kept within a preset range. Thus, the supply device 1 is controlled.

  The operation setting display unit 11 is configured using, for example, a touch panel or the like, and performs operation of the combination weigher, setting of operation parameters thereof, and the like, and displays an operation speed, a combination measurement value, and the like on a screen.

  The control device 9 performs operation control of the supply device 1 and overall operation of the combination weigher, and performs combination calculation and zero correction of the weighing hopper 13. In the combination calculation, the weight of the weighing object 20 in the weighing hopper 13 is measured by the weight sensor 10, and the measured value is set as the weight of the weighing object 20 in the weighing hopper 13. From the plurality of weighing hoppers 13, one appropriate combination is obtained in which the combined weight, which is the sum of the weight values of the objects 20 to be weighed, is equal to the combined target weight or the closest weight within the allowable range.

  In the case where the object to be weighed 20 is an object having a large surface frictional resistance such as bell pepper and not slippery, for example, the object to be weighed is retained in the supply of the object to be weighed 20 supplied from the top cone 3 to each linear feeder pan 6. If there is a variation, the weighing object 20 on the linear fee pan 6 becomes discontinuous, and the weighing object 20 cannot be conveyed temporarily or periodically to the conveying end 6a. The weighing object 20 cannot be supplied. The supply hopper 12 to which the object to be weighed 20 is not supplied cannot put the object to be weighed 20 into the weighing hopper 13, resulting in an empty weighing hopper 13.

  In this way, when an empty weighing hopper 13 in which the object to be weighed 20 is not input is generated, the timing of the zero correction periodically performed overlaps, and an empty object in which the object to be weighed 20 is not input for the zero point correction is overlapped. If the weighing hopper 13 is further added, the number of effective hoppers that can participate in the combination calculation is extremely reduced, the combination accuracy is lowered, and the yield is deteriorated.

  Therefore, in this embodiment, when the supply hopper 12 that cannot supply the weighing object 20 from the linear feeder pan 6 is generated, the weighing object 20 cannot be put into the corresponding weighing hopper 13 below the supply hopper 12. When the weighing hopper 13 is selected as an appropriate combination in the combination calculation and discharges the object 20 and the zero point correction is performed, the zero point correction is performed on the weighing hopper 13.

  That is, the weighing object 20 is supplied from the conveying end 6a of the linear feeder pan 6 to the supply hopper 12 due to stagnation or dispersion of the weighing object 20 supplied from the top cone 3 to each linear feeder pan 6. If the weighing object 20 cannot be put into the corresponding weighing hopper 13, the zero correction is preferentially performed on the weighing hopper 13, and therefore the supply of the weighing object 20 from the supply hopper 12 to the weighing hopper 13 is forcibly performed. Thus, the frequency of zero correction can be reduced by setting the weighing hopper 13 to an empty state. As a result, the number of empty weighing hoppers 13 that cannot participate in the combination calculation can be reduced, and the deterioration of the combination accuracy can be suppressed.

  In this embodiment, in order to determine whether or not the object to be weighed 20 has been supplied to the supply hopper 12, as shown in FIG. 1, the object to be weighed at the transport end 6a that is the tip of each of the plurality of linear feeder pans 6 is used. A plurality of objects to be weighed sensors 7 for detecting each of the objects to be weighed 20 are provided, and the control device 9 supplies the objects to be weighed 20 from the conveying end 6a of the linear feeder pan 6 to the supply hopper 12 based on the detection output of the objects to be weighed 7. It is determined whether or not is supplied.

  The determination as to whether or not the object 20 to be weighed has been supplied to the supply hopper 12 from the conveying end 6a of the linear feeder pan 6 can be performed as follows, for example.

  That is, before or during driving of the linear feeder 8, the weighing object 20 at the conveying end 6 a of the corresponding linear feeder pan 6 is not detected by the weighing object sensor 7, that is, there is no weighing object 20 at the conveying end 6 a. Sometimes, even if the linear feeder 8 is driven, it is determined that the object to be weighed 20 is not supplied from the transport end 6a to the supply hopper 12. Or, conversely, before or during the driving of the linear feeder 8, the weighing object 20 at the conveying end 6a of the corresponding linear feeder pan 6 is detected by the weighing object sensor 7, that is, the weighing object is measured at the conveying end 6a. When there is an object 20, it is determined that the object to be weighed 20 is supplied from the transport end 6 a to the supply hopper 12 by driving the linear feeder 8. In this case, the driving time of the linear feeder 8 is a time during which the weighing object 20 such as bell pepper can be transported, for example, by one distance, that is, one weighing object 20 is supplied to the supply hopper 12. It is good also as time which can be done.

  Although the determination is based on the ON / OFF detection output of the weighing object sensor 7 before or during the driving of the linear feeder 8, it may be performed based on the change in the detection output of the weighing object sensor 7. . For example, before the linear feeder 8 is driven, the detection output of the weighing object sensor 7 that detects the weighing object 20 at the conveyance end 6a of the corresponding linear feeder pan 6 is on (detected state), and the linear feeder 8 When the detection output of the object sensor 7 changes to OFF (non-detection state) by starting driving, the object to be weighed 20 at the transport end 6a is supplied to the supply hopper by driving the linear feeder 8. 12 may be determined to have disappeared from the transport end 6a.

  In this embodiment, for example, a photoelectric sensor is used as the weighing object sensor 7 that detects the weighing object 20, but the photoelectric sensor is not limited, and an image captured by a weight sensor such as a load cell, a limit switch, or a camera is used. Other sensors such as an image sensor to be processed may be used.

  FIG. 2 is a block diagram showing a schematic configuration of the control system of the combination weigher in this embodiment, and the same reference numerals are given to the portions corresponding to FIG.

  As shown in FIG. 2, the control device 9 includes a CPU unit 16 as an arithmetic control unit, a memory unit 17, an A / D conversion circuit unit 18, a gate drive circuit unit 19, a vibration control circuit unit 21, An I / O circuit unit 22 connected to the packaging machine 15 and an I / O circuit unit 25 to which a detection output of the object sensor 7 is given.

  The CPU unit 16 as a calculation control unit controls each unit, and performs combination calculation and zero correction of the weighing hopper 13. The memory unit 17 stores an operation program for the combination weigher, operation parameters to be set, and the like, and serves as a work area for operations on the CPU unit 16. The A / D conversion circuit unit 18 includes a weight sensor 5 for detecting the weight of the weighing object 20 on the top cone 3 and a weight sensor 10 for detecting the weight of the weighing object 20 of each weighing hopper 13. The analog signal is converted into a digital signal and output to the CPU unit 16. The CPU 16 is also provided with detection output from the above-mentioned object sensor 7 for detecting the object 20 to be measured at the conveyance end 6 a of each linear feeder pan 6 via the I / O circuit unit 25.

  The gate drive circuit unit 19 controls the opening / closing of the supply gate 12 a of the supply hopper 12 and the discharge gate 13 a of the weighing hopper 13 based on a control signal from the CPU unit 16. The vibration control circuit unit 21 controls each vibration operation of the supply device 1, the main feeder 4, and each linear feeder 8 based on a control signal from the CPU unit 16. The CPU unit 16 is connected so as to be able to communicate with the operation setting display unit 11.

  The control device 9 controls the operation of the supply device 1 and the entire combination weigher by the CPU unit 16 executing the operation program stored in the memory unit 17.

  In the combination weigher, it is necessary to set a large number of operation parameters for performing the operation as described above, and the setting is performed by the operator using the operation setting display unit 11, and the value of the set operation parameter is the CPU unit. 16 and stored in the memory unit 17. The operation parameters include a combination target weight which is a target value in the combination calculation and an allowable range thereof, an amplitude of vibration of each of the feeders 4 and 8, a driving time (one vibration duration time), and the like.

  FIG. 3 is a flowchart for explaining the entire processing operation of the combination weigher of this embodiment.

  First, the control device 9 performs ON / OFF control of the supply device 1 based on the detection output of the top cone weight sensor 5 to control the supply amount of the object 20 to be measured on the top cone 3. (Step s1).

  Next, the main feeder control for supplying the object 20 to the linear feeder pan 6 by controlling the driving of the main feeder 4 for vibrating the top cone 3 to disperse the object 20 on the top cone 3 to the surroundings is performed. (Step s2).

  Next, the driving of the linear feeder 8 that vibrates the linear feeder pan 6 is controlled, and the linear feeder pan 6 corresponding to the empty supply hopper 12 is vibrated so that the weighing object 20 on the linear feeder pan 6 is moved to the empty feeder hopper 6. Linear feeder control for supplying to the supply hopper 12 is performed (step s3).

  Next, the process proceeds to the supply hopper control in step s4. In this supply hopper control, the input gate 12a of the supply hopper 12 corresponding to the empty weighing hopper 13 is opened, the object 20 is introduced into the empty measurement hopper 13, and the process proceeds to step s5.

  In step s5, when the weighing object 20 is inserted into the weighing hopper 13, the weight of the weighing object 20 charged into the weighing hopper 13 is measured by the corresponding weight sensor 10, and the measured value is sent to the control device 9. Perform the weighing control.

  Next, based on the weight of the weighing object 20 put in the weighing hopper 13, combination calculation is performed, and whether the combined weight, which is the total weight of various weights of the weighing object 20, is equal to the combination target weight? Alternatively, an appropriate amount combination that is a combination of the weighing hoppers 13 that is heavier than the combination target weight and close to the combination target weight is selected (step s6).

  Thereafter, it is determined whether or not a discharge command signal is input from the packaging machine 15 (step s7). If a discharge command signal is input, the discharge hopper 13 for discharging the weighing hopper 13 of the appropriate combination selected by the combination calculation is used. Weighing hopper control for opening the gate 13a and discharging the object 20 to be weighed is performed (step s8), and the process returns to step s1. Thereafter, the weighing object 20 of an appropriate amount combination is discharged to the packaging machine 15 by repeating the same weighing cycle as described above.

  FIG. 4 is a flowchart showing a process for determining the timing for performing zero point correction, and this process is executed by a program that is activated at regular intervals.

  First, it is determined whether or not the zero point correction timing flag indicating the zero point correction timing is turned on (step s10). If it is turned on, the process ends. If not, the zero point correction timing is set. The measured value of the zero point correction timer for measurement is increased (step s11), and it is determined whether or not the measured value of the zero point correction timer coincides with a time interval of zero point correction performed periodically (step s12). The time interval for this zero point correction is set in advance.

  In step s12, when the measured value of the zero correction timer coincides with the zero correction time interval, the zero correction timing flag is turned on (step s13), assuming that the zero correction should be performed (step s13). All of the weighing hoppers 13 are turned on with the zero point correction flag indicating that they are candidates for the weighing hopper 13 to be subjected to zero point correction (step s14).

  FIG. 5 is a flowchart showing details of the linear feeder control in step s3 of FIG.

  First, the number k for specifying the plurality of linear feeders 1 to n is set to an initial value “1” (step s301). Next, it is determined whether or not the drive flag of the linear feeder 8 (k) is turned on (step s302). The drive flag of the linear feeder 8 is set for the linear feeder 8 corresponding to the supply hopper 12 that has been emptied by putting the object 20 into the weighing hopper 13 in the supply hopper control (step s4) of FIG. Is done. When the drive flag of the linear feeder 8 (k) is on, the drive time timer of the linear feeder 8 (k) is set and measurement of the drive time is started (step s303), and the linear feeder 8 (k) The driving flag is turned on (step s304), the driving of the linear feeder 8 (k) is started, and the process proceeds to step s306 (step s305).

  In step s306, whether the weighing object sensor 7 (k) that detects the weighing object 20 at the conveyance end 6a of the linear feeder pan 6 (k) corresponding to the linear feeder 8 (k) has detected the weighing object. Determine whether. In this step s306, when the weighing object sensor 7 (k) detects the weighing object 20, the weighing object 20 is present at the transport end 6a of the linear feeder pan 6 (k), so the linear feeder 8 (k ), The to-be-measured object 20 is put into the supply hopper 12 (k) from the transport end 6a, and the input flag for the supply hopper 12 (k) is turned on, and the process proceeds to step s317. In this step s306, when the weighing object sensor 7 (k) does not detect the weighing object 20, there is no weighing object 20 at the conveying end 6a of the linear feeder pan 6 (k), and the linear feeder 8 (k). Since the to-be-measured object 20 cannot be thrown into the supply hopper 12 (k) even if is driven, the charging flag for the supply hopper 12 (k) is turned off and the process proceeds to step s317. Accordingly, in step s308, the supply hopper 12 (k) whose input flag has been turned off has not been charged with the weighing object 20 immediately after the linear feeder 8 (k) starts to be driven, that is, the weighing object 20 Is determined not to be supplied.

  In step s302, when the driving flag of the linear feeder 8 (k) is not turned on, it is determined whether or not a driving flag indicating that the linear feeder 8 (k) is being driven is turned on (step s309). ) If not, the process proceeds to step s317.

  In step s309, when the driving flag of the linear feeder 8 (k) is on, the input flag of the supply hopper 12 (k) corresponding to the linear feeder 8 (k) is being driven while the linear feeder 8 (k) is being driven. Is turned on (step s310), and when the input flag is on, it is determined that the object 20 is already input to the supply hopper 12 (k), and the process proceeds to step s313.

  In step s310, when the input flag of the supply hopper 12 (k) is not on, that is, when the input flag is off, the conveyance end of the linear feeder pan 6 (k) corresponding to the supply hopper 12 (k). It is determined whether or not the weighing object sensor 7 (k) that detects the weighing object 20 of 6a detects the weighing object (step s311).

  In this step s311, when the weighing object sensor 7 (k) does not detect the weighing object 20, there is no weighing object 20 at the transport end 6a of the linear feeder pan 6 (k). 8 (k) also assumes that the workpiece 20 cannot be put into the supply hopper 12 (k) from the transport end 6a, and the process proceeds to step s313.

  In step s311, when the weighing object sensor 7 (k) detects the weighing object 20, the weighing object 20 is present at the conveyance end 6a of the linear feeder pan 6 (k). Assuming that the object to be weighed 20 is thrown into the supply hopper 12 (k) from the transport end 6a by (k), the charging flag for the supply hopper 12 (k) is turned on and the process proceeds to step s313 (step s312).

  In step s313, a drive time timer for measuring the drive time of the linear feeder 8 (k) is subtracted to determine whether or not the time is up (step 314). When it is up, the driving flag of the linear feeder 8 (k) is turned off (step s315), the driving of the linear feeder 8 (k) is stopped, and the process proceeds to step s317.

  In step s317, the number k is incremented by 1, and it is determined whether or not the number k is n + 1 (step s318). If not, the process returns to step s302 and the same processing is performed for the next linear feeder 8. To do. In step s318, when n + 1 is reached, the process ends.

  As described above, in the linear feeder control, the input flag corresponding to whether or not the weighing object 20 is supplied to the supply hopper 12 from the conveying end 6a of the linear feeder pan 6 is turned on and off by driving the linear feeder 8.

  FIG. 6 is a flowchart showing details of supply hopper control in step s4 of FIG.

  First, the number k for specifying the plurality of supply hoppers 1 to n is set to an initial value “1” (step s401). Next, it is determined whether or not a charging gate drive flag for driving the charging gate 12a of the supply hopper 12 (k) is turned on (step 402). In this step s402, when the input gate drive flag for the supply hopper 12 (k) is not turned on, the corresponding weighing hopper 13 (k) has not discharged the object 20 and the object 20 has been input. As it is not necessary to proceed to step s406.

  In step s402, when the input gate drive flag of the supply hopper 12 (k) is on, the corresponding weighing hopper 13 (k) has discharged the object 20 and is in an empty state. The loading gate 12a of the hopper 12 (k) is driven to open the loading gate 12a, and the object 20 is loaded into the corresponding weighing hopper 13 (k) (step s403), and the weighing hopper 13 (k ) Turns on a loading completion flag indicating that the loading of the object 20 has been completed, and proceeds to step s405 (step s404).

  In step s405, the corresponding linear feeder 8 (k) is driven in order to supply the object 20 to the supply hopper 12 (k) which has been emptied by putting the object 20 into the weighing hopper 13 (k). The flag is turned on and the process proceeds to step s406.

  In step s406, the number k is incremented by 1, and it is determined whether or not the number k is n + 1 (step s407). If not, the process returns to step s402 and the same applies to the next supply hopper 12 and the like. Perform processing. In step s407, when it becomes n + 1, the process ends.

  FIG. 7 is a flowchart showing details of the metering control in step s5 of FIG.

  First, the number k for specifying the plurality of weighing hoppers 1 to n is set to an initial value “1” (step s501). Next, it is determined whether or not the loading completion flag of the weighing hopper 13 (k) is turned on (step s502). When the loading completion flag is turned on, the weighing hopper 13 (k) is in the stable period of the balance. Is turned on (step s503), a measurement stability timer for measuring the stabilization time until the measurement value is stabilized is set (step s504), and the input completion flag of the measurement hopper 13 (k) is set. Turn off and proceed to step s521 (step s505).

  If the loading completion flag of the weighing hopper 13 (k) is not turned on in step s502, it is determined whether or not the stable flag of the weighing hopper 13 (k) is turned on (step s506). When it is on, the weighing stability timer is subtracted (step s507), and it is determined whether or not the stabilization time has elapsed, that is, whether or not the time is up (step s508). The process moves to s521. When the time is up in step s508, the measurement value of the weighing hopper 13 (k) is read, the measurement completion flag indicating that the measurement is completed is turned on (step s509), and the stable flag of the measurement hopper 13 (k) is set. Turn off and go to step s521 (step s510).

  In step s506, when the stable flag of the weighing hopper 13 (k) is not turned on, it is determined whether or not the zero correction execution flag indicating whether or not the zero correction is performed on the weighing hopper 13 (k) is turned on. Judgment is made (step 511), and when it is turned on, a zero point correction stabilization flag indicating that the weighing hopper 13 (k) is in the stable period of the balance for zero point correction is turned on (step s512). A zero point correction stabilization timer for measuring the correction stabilization time is set (step s513), the zero point correction execution flag of the weighing hopper 13 (k) is turned off, and the process proceeds to step s521 (step s514).

  If the zero correction execution flag of the weighing hopper 13 (k) is not turned on in step s511, it is determined whether or not the zero correction stable flag of the weighing hopper 13 (k) is turned on (step s515). If it is, the zero point correction stabilization timer is subtracted (step s), and it is determined whether or not the zero point stabilization time has elapsed, that is, whether or not the time is up (step s517).

  In step s517, when the time is up, the zero point correction stabilization flag of the weighing hopper 13 (k) is turned off (step s518), the measured value of the weighing hopper 13 (k) is read, and zero correction is performed to make a new zero point. (Step s519), the process proceeds to step s520. In step s520, the zero correction in-progress flag indicating that the zero correction is being performed for the weighing hopper 13 (k) is turned off, and the flow proceeds to step s521 (step s520).

  In step s515, when the zero point correction stable flag of the weighing hopper 13 (k) is not turned on, and when the time is not up in step s517, the process proceeds to step s521.

  In step s521, the number k is incremented by 1, and it is determined whether or not the number k is n + 1 (step s522). If not, the process returns to step s502 and the same processing is performed for the next weighing hopper 13. To do. In step s522, when n + 1 is reached, the process ends.

  FIG. 8 is a flowchart showing details of the weighing hopper control in step s8 of FIG.

  First, a number k for specifying a plurality of weighing hoppers 1 to n is set to an initial value “1” (step s801). Next, it is determined whether or not the weighing hopper 13 (k) is selected as an appropriate combination by the combination calculation (step s802). If not selected, the process proceeds to step s811. When the appropriate amount combination is selected, in order to discharge the object 20 to be discharged, the driving of the discharge gate 13a of the weighing hopper 13 (k) is set (step s803), and zero point correction is being performed. It is determined whether or not the indicated zero point correction execution flag is on (step s804). If the zero point correction execution flag is on, the process proceeds to step s811.

  In step s804, when the zero point correction execution flag is not turned on, it is determined whether or not the supply flag of the supply hopper 12 (k) is turned on (step s805). When the supply flag is turned on, the supply is performed. Assuming that the object 20 to be weighed is put in the hopper (k), the process proceeds to step s811.

  In step s805, when the input flag is not turned on, the weighing object 20 is not input to the supply hopper 12 (k), and therefore the zero correction flag of the corresponding weighing hopper 13 (k) is turned on. Is determined (step s806).

 If the zero point correction flag of the weighing hopper 13 (k) is not turned on in step s806, the weighing hopper 13 (k) is not a candidate for performing zero point correction, and the process proceeds to step s811. In step s806, when the zero point correction flag of the weighing hopper 13 (k) is on, the weighing hopper 13 (k) moves to step s807, assuming that it is a candidate for zero point correction.

  In step s807, it is determined whether or not the zero point correction execution flag of the other weighing hopper 13 is turned on. If it is turned on, the zero point correction is performed on the other weighing hopper 13 and the process proceeds to step s811. In step s807, when the zero point correction execution flag of the other weighing hoppers 13 is not turned on, the zero point correction is not performed for the other weighing hoppers 13, so that the zero point correction is performed for the weighing hopper 13 (k). The zero point correction execution flag of the weighing hopper 13 (k) is turned on (step s808), the zero point correction execution flag indicating that the zero point correction is being performed is turned on (step s809), the zero point correction flag is turned off, and the step The process moves to s811 (step s810).

  In step s811, the number k is incremented by 1, and it is determined whether or not the number k is n + 1 (step s812). If not, the process returns to step s802 and the same processing is performed for the next weighing hopper 13. To do. In step s812, when n + 1 is reached, the process ends.

  When all the supply hoppers 12 are turned on, that is, when there is no supply hopper 12 to which the object to be weighed 20 is not charged, the weighing is performed sequentially from the supply hopper 12 as in the conventional case. The zero point correction of the weighing hopper 13 is performed by forcibly prohibiting the input of the object to be weighed into the hopper 13.

  As described above, when the supply hopper 12 in which the object to be weighed 20 cannot be supplied from the linear feeder pan 6 is generated, the corresponding weighing hopper 13 below the selected hopper 13 is selected as an appropriate combination by the combination calculation and is weighed. When the object 20 is discharged and the zero point correction timing is reached, the zero point correction is performed on the weighing hopper 13, so that the other weighing hoppers 13 can perform the zero point correction on the other weighing hoppers 13. There is no need to forcibly prohibit the input of the object 20 to be measured 13 to make the other weighing hopper 13 empty.

  As described above, when the weighing object 20 cannot be supplied to the supply hopper 12 from the conveyance end 6a of the linear feeder pan 6 and the weighing object 20 cannot be put into the corresponding weighing hopper 13, the zero correction is performed on the weighing hopper 13. Since this is performed preferentially, the supply of the object 20 to be weighed from the supply hopper 12 to the weighing hopper 13 is forcibly prohibited, and the frequency of zero correction can be reduced by making the weighing hopper 13 empty. As a result, the number of empty weighing hoppers 13 that cannot participate in the combination calculation can be reduced, and the deterioration of the combination accuracy can be suppressed.

(Other embodiments)
A plurality of supply hoppers 12 in which the object to be weighed 20 could not be supplied from the linear feeder pan 6 are generated, and a plurality of corresponding weighing hoppers 13 below are selected as appropriate combinations by combination calculation and discharge the object to be weighed 20 respectively. In addition, when it is time for zero point correction, zero point correction may be performed for the plurality of weighing hoppers 13.

  In the above-described embodiment, the amount of the object 20 to be weighed on the top cone 3 is detected by the top cone weight sensor 5. However, as another embodiment of the present invention, instead of the weight sensor, above the top cone 3. For example, an ultrasonic type level detector is provided, and the level detector detects the amount of the object 20 on the top cone 3 and controls the amount of the object 20 on the top cone 3. Also good.

  As described above, if there is a stagnation or variation in the supply of the weighing object 20 from the top cone 3 to each linear feeder pan 6, the weighing object 20 cannot be supplied from the conveying end 6 a of the linear feeder pan 6 to the supply hopper 12. As a cause of the above-mentioned retention and variation, for example, in the case of the object 20 to be weighed having a large surface frictional resistance such as bell pepper and not slipping easily, the top cone 3 and a certain linear feeder pan 6 are used. In the vicinity of the boundary portion, the objects 20 to be weighed may be accumulated and overlapped to form a so-called bridge, and it may be impossible to supply the objects to be weighed 20 to a certain linear feeder 6. Therefore, when the state in which the object 20 cannot be supplied from the conveying end 6a of the linear feeder pan 6 to the supply hopper 12 is repeated, the supply of the object 20 to the top cone 3 from the supply device 1 is forcibly dropped. In this case, the bridge may be broken by the impact when the object to be weighed 20 is dropped so that the object to be weighed can be supplied from the top cone 3 to the certain linear feeder pan 6. .

DESCRIPTION OF SYMBOLS 1 Supply apparatus 3 Top cone 4 Main feeder 5 Top cone weight sensor 6 Linear feeder pan 7 Weighing object sensor 8 Linear feeder 9 Control device 10 Weight sensor 12 Supply hopper 13 Weighing hopper 15 Packaging machine 16 CPU part 20 Weighing object

Claims (5)

A plurality of transport units for transporting the objects to be weighed and discharging them from the transport end;
A plurality of supply units that are arranged corresponding to the respective conveyance units, hold the objects to be weighed discharged from the conveyance end, and supply the held objects to be weighed downward,
A plurality of measuring units arranged corresponding to each supply unit, holding the objects to be weighed supplied from each supply unit, and weighing the weight of the objects to be weighed;
Performs zero correction of the weighing unit, performs combination calculation based on the measured value of the object to be weighed by the weighing unit, selects an appropriate combination weighing unit, and discharges the weighing object of the selected weighing unit An arithmetic control unit to be
A combination weigher comprising:
A weighing object sensor for detecting a weighing object at each conveyance end of each conveyance unit and providing a detection output to the calculation control unit;
The arithmetic control unit controls the driving of the conveyance unit, and determines that the measurement object is not supplied from the conveyance end to the supply unit based on the detection output of the measurement object sensor. A weighing unit corresponding to the determined supply unit, which is selected as the appropriate amount combination, discharges an object to be weighed, and performs zero point correction on the weighing unit which is a timing at which zero point correction is to be performed;
A combination weigher characterized by that. When there is no supply unit for which it is determined that the object to be weighed is not supplied, the arithmetic control unit selects the appropriate amount combination, discharges the object to be weighed, and is a timing at which zero correction should be performed. Perform zero correction for the part.
The combination weigher according to claim 1. When there are a plurality of weighing units that are selected as the appropriate amount combination, discharge the object to be weighed, and there are a plurality of weighing units that are to be subjected to zero point correction, the arithmetic control unit selects any one weighing unit and corrects the zero point. Do,
The combination weigher according to claim 2. The plurality of conveyance units are a plurality of vibration feeders that convey an object to be weighed by vibration,
The plurality of supply units are a plurality of supply hoppers that supply the objects to be weighed to the measurement unit,
The plurality of weighing units are a plurality of weighing hoppers for weighing the weight of an object to be weighed by a weight sensor,
The arithmetic control unit controls the driving of the vibration feeder, and controls opening and closing of the gate for feeding the supply hopper and the gate for discharging the weighing hopper,
The combination weigher according to any one of claims 1 to 3. The arithmetic and control unit is a weighing hopper corresponding to the supply hopper that is determined not to supply the object to be weighed by prohibiting the opening and closing of the supply hopper that has been determined that the object to be weighed is not being supplied. The zero point correction is performed on the weighing hopper which is selected as the appropriate amount combination, discharges the object to be weighed, and is the timing at which the zero point correction should be performed.
The combination weigher according to claim 4.

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