JP6348412B2 - Combination scale - Google Patents

Description

  The present invention relates to a combination weigher that combines and weighs objects to be weighed so as to have a weight within a predetermined weight range.

  The combination weigher generally includes a plurality of weighing hoppers, and the combination weight obtained by variously combining the weights of the objects to be weighed supplied to the plurality of weighing hoppers is equal to or equal to the target combination weight. A combination of weighing hoppers that is in the near predetermined weight range is selected, and an object to be weighed is discharged from the selected weighing hopper. Usually, a combination weigher is used together with a packaging machine, and objects to be weighed within a predetermined weight range measured by the combination weigher are discharged from the combination weigher, put into the packaging machine, and packaged as one packaged item by the packaging machine. .

  For example, when the food to be weighed contains a lot of moisture such as sugared confectionery such as sweet natto and pickles, sugar, pickled juice, or fragments of the material to be weighed adhere to the inner wall of the weighing hopper. There is a case.

  For this reason, the weighing hopper is made of a plate material having an uneven surface, and adhesion of the object to be weighed is also prevented by the uneven surface, but it is difficult to completely prevent the object to be weighed from adhering. .

  When an object to be weighed adheres to the weighing hopper, the actual weight of the object to be discharged discharged from the weighing hopper becomes smaller than the target combined weight.

  In order to reduce the weighing error due to the adhesion of the weighing object, etc., the weighing hopper is emptied by prohibiting the feeding of the weighing object to the weighing hopper for one weighing cycle, and the weight of the weighing hopper in the empty state ( The zero point weight) is measured, and zero point correction is performed with the amount of the object to be weighed as the tare amount.

  Further, in Patent Document 1, data on an actual measurement value of the weight of an object to be weighed discharged from a weighing hopper is obtained from an external scale, and when the average of the actual measurement values is smaller than a planned weight, the target combination weight is corrected upward, When the average of the actually measured values is larger than the planned weight, the target combination weight is corrected downward to suppress the influence on the weighing due to the adhesion of the object to be weighed.

JP 2010-175514 A

  In the combination weigher, the above-mentioned “target combination weight” is set, and “the actual content of the product discharged from the combination weigher and packaged by the packaging machine” is set so that it does not fall below the “nominal weight”. "Flat" is set.

  In the combination weigher, a weight obtained by adding a “fill” to a set target combination weight (hereinafter referred to as “set target combination weight”) is set as an actual target combination weight used for the combination calculation. That is, the actual “target combination weight” used for the combination calculation is expressed as follows.

"Target combination weight" = "Set target combination weight" + "Inset"
“Cut” is added so that the actual content of the product does not fall below the nominal weight due to various factors. Conventionally, for example, the amount of reduction due to transpiration of water from the product, to the weighing hopper, etc. Insufficient stabilization time from when the weighing object is fed to when the weighing signal stabilizes and the weight value is acquired, disturbance such as floor vibration where the combination weigher is installed, and the weighing object to the weighing hopper The amount of adhesion is set in consideration of necessity.

  By setting the perforations, the target combination weight used in the combination calculation is increased accordingly, so that the yield decreases as the perforations increase.

  The adhesion of the object to be weighed to the weighing hopper progresses in the initial stage of operation where the elapsed time from the start of operation is relatively short, but then stabilizes with little progress.

  Conventionally, the “filler” is set so as to include the amount of the object to be weighed on the weighing hopper, but remains at the initially set value regardless of the elapsed time from the start of operation.

  Therefore, the elapsed time from the start of operation is long, the adherence of the object to be weighed hardly progresses, and even after the adhering amount is stabilized, the combination calculation is performed by the target combination weight added with the initially set “sealed”. There is a problem that the target combination weight is unnecessarily raised and the yield is lowered.

  The present invention has been made paying attention to such a situation, and an object thereof is to improve the yield without unnecessarily increasing the target combination weight.

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

(1) The present invention is a combination weigher including a plurality of weighing hoppers to which an object to be weighed is supplied,
Combination calculation means for performing combination calculation for selecting a combination of weighing hoppers to discharge the objects to be weighed based on the weights of the objects to be weighed supplied to the respective weighing hoppers and the target combination weight;
Determination means for determining whether or not the amount of the object to be weighed on the weighing hopper is stable;
Zero point correction means for correcting the zero point of the weighing hopper,
The combination calculation unit changes the target combination weight to a target combination weight smaller than the target combination weight when the determination unit determines that the adhesion amount is stable.

  According to the present invention, when the zero point correction of the weighing hopper is performed and it is determined that the amount of the object to be weighed on the weighing hopper is stable, the target combination weight is changed to a small target combination weight. At the beginning of operation when the amount of adhesion is not stable due to the progress of adhesion, the weight of the object to be weighed is set to the tare amount by correcting the zero point of the weighing hopper, and the combination calculation is performed with the target combination weight raised in anticipation of the object to be weighed. After that, when the amount of adhesion becomes stable with almost no new adhesion proceeding, the combination calculation is performed by changing to a smaller target combination weight with less increase in the height, so the target combination weight is unnecessarily increased. Therefore, the combination calculation is performed, and the yield can be improved as compared with the conventional example.

  (2) In a preferred embodiment of the present invention, the determination means determines whether or not the adhesion amount is stable based on an elapsed time from the start of operation.

  According to this embodiment, when the elapsed time from the start of operation becomes longer, the adhesion of the object to be weighed to the weighing hopper hardly progresses and the adhesion amount is stabilized. By measuring the elapsed time, the adhesion amount It can be determined whether or not is stable.

  (3) In a preferred embodiment of the present invention, the determination unit determines whether or not the adhesion amount is stable based on a zero point fluctuation amount obtained by the zero point correction by the zero point correction unit.

  According to this embodiment, the zero point of the weighing hopper fluctuates according to the amount of the object to be weighed at the initial stage of operation when the object to be weighed adheres to the weighing hopper and the amount of adhesion is not stable. When the amount of adhesion hardly progresses and the amount of adhesion becomes stable, the fluctuation of the zero point is almost eliminated. Therefore, based on the amount of fluctuation of the zero point, it can be determined whether or not the amount of adhesion is stable.

  (4) In another embodiment of the present invention, the small target combination weight is the second target combination weight, the target combination weight before being changed to the second target combination weight is the first target combination weight, When the weight obtained by subtracting the second target combination weight from the first target combination weight is used as an adhesion correction amount, an adhesion correction amount setting unit is provided for setting the adhesion correction amount.

  According to this embodiment, in the initial stage of operation when the adherence of the object to be weighed proceeds and the adhering amount is not stable, the combination calculation is performed using the first target combination weight in which the adhering correction amount is increased in anticipation of the adhering of the object to be weighed. After that, when new adhesion hardly progresses and the adhesion amount becomes stable, the combination calculation is performed by changing to the second target combination weight reduced by the adhesion correction amount. The combination calculation is performed without increasing the weight, and the yield can be improved as compared with the conventional example. The adhesion correction amount can be set in advance by operating the setting means.

  (5) In the embodiment of the above (4), it is possible to provide notifying means for notifying the zero point fluctuation amount obtained by the zero point correction by the zero point correcting means.

  The zero-point fluctuation amount to be notified may be the zero-point fluctuation amount from the previous zero correction every time zero correction is performed, or it is determined that the adhesion amount of the object to be measured has been stabilized by the determination means from the start of operation. It may be a cumulative value of the zero point fluctuation amount up to.

  Further, the zero point fluctuation amount may be that of the weighing hopper having the largest zero point fluctuation, or an average value of the zero point fluctuation amounts of a plurality of weighing hoppers.

  The notification means preferably displays the zero point fluctuation amount for notification, but may notify it by printing or voice.

  Zero point correction is to measure the weight when the weighing hopper is empty (zero point weight), correct the zero point, and use the amount of the object to be weighed as the tare amount. It depends on the amount of the sample.

  According to this embodiment, since the zero point fluctuation amount corresponding to the amount of the object to be weighed on the weighing hopper is notified, the operator is notified of the zero point fluctuation amount when setting the adhesion correction amount by the setting means. Can be helpful.

  (6) In a preferred embodiment of the present invention, when the small target combination weight is set as the second target combination weight, and the target combination weight before changing to the second target combination weight is set as the first target combination weight. The combination calculation means changes the first target combination weight according to the zero point fluctuation amount obtained by the zero point correction by the zero point correction means.

  As described above, the zero point correction is to measure the weight when the weighing hopper is empty (zero point weight) to correct the zero point, and to set the amount of the object to be weighed as the tare amount. It depends on the amount of objects to be weighed on the weighing hopper.

  According to this embodiment, at the initial stage of operation when the adhesion of the object to be weighed proceeds and the amount of adhesion is not stable, the first target combination weight, which is the target combination weight at that time, varies according to the amount of object to be weighed. Therefore, the first target combination weight can be increased according to the adherence of the object to be weighed, the first target combination weight is not unnecessarily increased, and the yield is further increased. It is possible to improve, and it is not necessary to set the raising amount as an adhesion correction amount in advance.

  (7) In the embodiment of the above (6), the combination calculation means multiplies the zero point fluctuation amount by an average value of the number of weighing hoppers selected in the combination calculation, thereby changing the first target combination weight change amount. May be requested.

  The target combination weight is a target value of the combined weight obtained by combining the weights of the objects to be weighed in a plurality of weighing hoppers, whereas the zero point variation obtained by the zero correction of the weighing hopper is the variation per weighing hopper. Therefore, according to this embodiment, the amount of change corresponding to the target combination weight is obtained by multiplying the zero point fluctuation amount per weighing hopper by the average value of the number of weighing hoppers selected in the combination calculation. be able to.

  According to the present invention, the zero point correction is performed, and in the initial stage of operation when the adhesion of the object to be weighed proceeds and the adhesion amount is not stable, the combination calculation is performed with the target combination weight raised in anticipation of the adhesion, and then the new adhesion is performed. When the amount of adhesion does not progress and the amount of adhesion becomes stable, the combination calculation is performed by changing to the target combination weight with less increase in height, so the combination calculation is performed without unnecessarily increasing the target combination weight. Therefore, the yield can be improved as compared with the conventional example.

It is a schematic diagram which shows schematic structure of the combination scale which concerns on one Embodiment of this invention. It is a block diagram which shows the structure of the control system of the combination weigher of FIG. It is a flowchart which shows the change process of the target combination weight in the combination calculation of the combination weigher of FIG. It is a flowchart corresponding to FIG. 3 of other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described 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. This combination weigher is provided with a main feeder (dispersing feeder) 2 at the center of the upper part of the apparatus, which disperses and transports the objects to be weighed and dropped from the supplying device 1 by vibration.

  The objects to be weighed are not particularly limited, but are suitable for foods such as confectionery and pickles that are not individually packaged.

  The dispersion feeder 2 includes a conical top cone 3 and a vibration mechanism 4 that drives the top cone 3 to vibrate.

  Around the dispersion feeder 2, a plurality of linear feeders 5 that radially convey the object to be weighed that has been oscillated and transferred to the peripheral portion of the top cone 3 outwardly are arranged radially. The linear feeder 5 includes a trough (feeder pan) 6 on which an object to be weighed is placed, and an excitation mechanism 7 that drives the trough 6 to vibrate.

  A supply hopper 8 is provided below the outer end portion of each linear feeder 5, and a weighing hopper 9 is provided below each supply hopper 8.

  Discharge gates 8 a and 9 a that can be opened and closed are provided below the supply hopper 8 and the weighing hopper 9, respectively. The supply hopper 8 receives the object to be weighed which is transported by the linear feeder 5 and dropped and discharged from the transport end, temporarily holds it, and when the weigh hopper 9 disposed below becomes empty, the feeding gate 8a is opened. Then, the object to be weighed is dropped and discharged into the weighing hopper 9. Each weighing hopper 9 is connected to a weight sensor 10 such as a load cell for measuring the weight of an object to be weighed in the hopper, and weighing data from each weight sensor 10 is output to the control device 11.

  The objects to be weighed discharged from the weighing hoppers 9 are guided to flow downward by the collecting chute 12 arranged below each weighing hopper 9, gathered by the collecting funnel 13, and then gathered below the collecting hopper 9. 14 and temporarily held.

  A combination of the weighing hoppers 9 from which the objects to be weighed are to be discharged is obtained from the plurality of weighing hoppers 9 by the combination calculation by the control device 11, and the objects to be weighed are discharged from the weighing hoppers 9 corresponding to the combination to the collecting hopper 14. When the discharge request signal is input from the packaging machine, the discharge gate 14a of the collecting hopper 14 is controlled to be opened, and discharged to the packaging machine 15 disposed below.

  In this embodiment, the weight of the object to be weighed supplied from the supply device 1 onto the top cone 3 is measured by the weight sensor 16, and the measured value is given to the control device 11. The control device 11 controls the supply device 1 so that the object to be weighed on the top cone 3 is kept within a preset range.

  In the control device 11, the operation control of the supply device 1 and the entire operation control of the combination weigher are performed, and the combination calculation and the zero correction in the weighing hopper 9 are performed. In the combination calculation, an appropriate amount combination in which the combination weight, which is the sum of the weight values of the objects to be weighed, is equal to the target combination weight or the weight closest to the target combination weight within the allowable range among the plurality of weighing hoppers 9. Is selected.

  To correct the zero point of the weighing hopper 9, after discharging the object to be weighed from the weighing hopper 9, the weighing hopper 9 is emptied by prohibiting the input of a new object to be weighed, and the weight at that time (zero point weight). Is measured, zero point correction is performed, and the amount of the object to be weighed is stored as a tare amount, and is sequentially performed for each weighing hopper 9.

  This zero point correction is performed in a short time interval at the initial stage of operation in which the elapsed time from the start of operation is short, and the adherence of the object to be weighed to the weighing hopper 9 proceeds, and thereafter the object to be weighed to the weighing hopper 9 is As the adhesion hardly progresses, it is performed at a long time interval.

  FIG. 2 is a block diagram showing a schematic configuration of a control system of the combination weigher in this embodiment, and parts corresponding to those in FIG. 1 are denoted by the same reference numerals.

  As shown in FIG. 2, the control device 11 includes a CPU unit 17 as a calculation control unit, a memory unit 18, an A / D conversion circuit unit 19, a gate drive circuit unit 20, a vibration control circuit unit 21, and a packaging machine 15. A connected I / O circuit unit 22 is provided, and an operation setting display unit 23 is connected.

  The CPU unit 17 as a calculation control unit controls each unit and measures combination calculation, zero correction of the weighing hopper 9 and elapsed time from the start of operation, and the amount of the object to be weighed on the weighing hopper 9 Judge whether or not is stable. The memory unit 18 stores an operation program for the combination weigher, set operation parameters, and the like, and serves as a work area for operations for the CPU unit 17. The A / D conversion circuit unit 19 receives analog signals from the weight sensor 16 for detecting the weight of the weighing object on the top cone 3 and the weight sensor 10 for detecting the weight of the weighing object in the weighing hopper 9. The digital signal is converted and output to the CPU unit 17.

  The gate drive circuit unit 20 controls the opening / closing of the discharge gate 8a of the supply hopper 8, the discharge gate 9a of the weighing hopper 9, and the discharge gate 14a of the collecting hopper 14 based on a control signal from the CPU unit 17. . The vibration control circuit unit 21 controls the supply device 1, the vibration mechanism 4 of the main feeder 2, and the vibration mechanism 7 of each linear feeder 5 based on a control signal from the CPU unit 17.

  The control device 11 controls the operations of the supply device 1 and the entire combination weigher by the CPU unit 17 executing the operation program stored in the memory unit 18.

  In the combination weigher, it is necessary to set a large number of operation parameters in order to perform the above-described operation. The operator performs the setting using the operation setting display unit 23, and the set operation parameter value is the CPU unit 17. To be stored in the memory unit 18. The operation parameters include a target combination weight that is a target value in the combination calculation, a stitch, an allowable range for the target combination weight, an adhesion correction amount to be described later, an amplitude and a driving time of each of the feeders 2 and 5 (continuous vibration once) Time).

  When the objects to be weighed are, for example, confectionery not individually packaged, sugar or pieces of objects to be weighed may adhere to the inner wall of the weighing hopper 9.

  The adherence of the object to be weighed to the weighing hopper 9 proceeds in the initial stage of operation where the elapsed time from the start of operation in the state where the object to be weighed does not adhere to the weighing hopper 9 is short, and thereafter, it hardly proceeds and the amount of adhesion Is stable.

  Conventionally, the “fill” is set by operating the operation setting display unit 23 so that the actual content of the product packaged by the packaging machine 15 does not fall below the nominal weight. The “eye” is set including the amount of the object to be weighed on the weighing hopper 9. Further, the target combination weight is set by operating the operation setting display unit 23.

  Conventionally, a weight obtained by adding a stitch to a set target combination weight (hereinafter referred to as “set target combination weight”) is used as an actual target combination weight used in the combination calculation. That is, the actual “target combination weight” used for the combination calculation is expressed as follows.

"Target combination weight" = "Set target combination weight" + "Inset"
As described above, the stitch is set including the amount of the object to be weighed on the weighing hopper, but it remains at the initially set value regardless of the elapsed time from the start of operation.

  Therefore, the elapsed time from the start of operation is long, the adherence of the object to be weighed hardly progresses, and even after the amount of adhesion is stabilized, the combination calculation is performed with the target combination weight added with the initially set “seam”. In other words, the target combination weight is unnecessarily raised and the yield is lowered.

  In this embodiment, in order to improve the yield without unnecessarily increasing the target combination weight, the following configuration is adopted.

  That is, in this embodiment, the “fill” is set without including the amount of the object to be weighed on the weighing hopper 9, and the amount of the object to be weighed on the weighing hopper 9 is set as a setting means. Is set as “adhesion correction amount”.

  Then, the amount of the object to be weighed is stable in the initial stage of operation when the amount of the object to be weighed on the weighing hopper 9 advances and the amount of adhesion is not stable, specifically, until a certain time elapses from the start of operation. The combination calculation is performed using the first target combination weight expressed by the following equation.

"First target combination weight"
= “Set target combination weight” + “Eye” + “Adhesion correction amount”
Then, when the predetermined time has elapsed, it is determined that the new adhesion hardly progresses and the adhesion amount is stable, and is changed to the second target combination weight represented by the following formula, which is smaller than the first target combination weight. To perform a combination operation.

"Second target combination weight"
= “Set target combination weight” + “Inset”
That is, for a certain period of time after the start of operation in which adhesion of the object to be weighed to the weighing hopper 9 proceeds, the amount of object to be weighed is not stable, and the “first target combination” is increased by the “adhesion correction amount”. Perform combination calculation using "Weight". Then, after the elapse of a certain time when the object to be weighed hardly adheres to the weighing hopper 9, the amount of the object to be weighed is assumed to be stable, and the “adhesion correction amount” is not raised. The combination calculation is performed using “weight”.

  As a result, even after the adherence of the object to be weighed hardly progresses, compared to the conventional example in which the combination calculation is performed with the target combination weight obtained by adding the “sealed” set including the amount of the object to be weighed as it is. Yield is improved.

  In this embodiment, the zero point correction is performed at a short time interval from the start of operation in which the object to be weighed adheres to the weighing hopper 9 until the fixed time elapses, and thereafter the weighing hopper 9 is covered with the weighing hopper 9. Since the adhesion of the weighing object is almost eliminated and the operation state is stabilized, the measurement is performed at a long time interval. By this zero point correction, the amount of the object to be weighed on the weighing hopper 9 is set to the tare amount. The time interval for zero point correction is set in advance by operating the operation setting display unit 23.

  The “adhesion correction amount” can be set as the amount of the object to be weighed on the weighing hopper 9 that was conventionally included in the “sealing”.

  Therefore, in this embodiment, the conventional “fill” that includes the amount of the object to be weighed on the weighing hopper 9 is replaced with the “mesh” that does not include the amount of the object to be weighed. It can also be understood that it is divided into “adhesion correction amount” corresponding to the amount of adhesion.

  As described above, the “adhesion correction amount” may be included as the amount of the object to be weighed on the weighing hopper 9 in the setting of the conventional “seam”. In this setting, it may be set with reference to the zero point variation obtained by the zero point correction.

  In other words, the zero point correction is to discharge the object to be weighed from the weighing hopper 9 and then prohibit the introduction of a new object to be weighed for one measuring cycle, empty the measuring hopper 9 and measure the weight at that time (zero point weight). Thus, the zero point is corrected, and the amount of the object to be weighed is the tare amount.

  Therefore, if the amount of the object to be weighed increases on the weighing hopper 9 during the period from the previous zero correction to the current zero correction, the corresponding amount appears as a zero change, that is, a zero fluctuation.

  Therefore, by accumulating the zero point fluctuation amount until a predetermined time has elapsed from the start of operation and displaying it on the operation setting display unit 23, the operator refers to the accumulated value of the displayed zero point fluctuation amount and performs “adhesion correction”. The “amount” may be determined.

  Since the zero point correction is sequentially performed for each weighing hopper 9, the accumulated value of the zero point fluctuation amount is calculated for each weighing hopper 9. For example, the accumulated value of the zero point fluctuation amount of the weighing hopper 9 having the largest zero point fluctuation amount is calculated. It may be used, or an average value of accumulated values of the zero point fluctuation amounts of the plurality of weighing hoppers 9 may be used.

  The target combination weight is the target value of the combination weight obtained by combining the weights of the objects to be weighed in the plurality of weighing hoppers 9, whereas the accumulated value of the zero point variation is the zero point of the weighing hopper 9 per unit. This is the cumulative value of the fluctuation amount.

  Therefore, an average value of the number of weighing hoppers 9 selected as an appropriate amount combination in the most recent combination operation is obtained, and the average value of the number of weighing hoppers 9 is multiplied by the accumulated value of the zero-point fluctuation amount. It may be displayed as “adhesion correction amount”.

  In addition, a value obtained by multiplying the average value of the number of weighing hoppers 9 by the accumulated value of the zero point fluctuation amount and further multiplying by a coefficient may be displayed as “adhesion correction amount”.

  FIG. 3 is a flowchart showing a combination calculation process by changing the target combination weight.

  When the weighing hopper 9 is started to operate without any object to be weighed (starting the start-up operation or starting the operation after washing the combination weigher for changing the type of the object to be weighed) An adhesion correction timer for measuring a certain time is set (step S01), and it is determined whether or not the adhesion correction timer is up (step S02). Note that the fixed time set in the adhesion correction timer is set and input in advance in the operation setting display unit 23. This fixed time is set and inputted with reference to actual measurement data acquired in advance as the time from the start of operation until the amount of deposits stabilizes when weighing the same type of objects to be weighed.

  When the adhesion correction timer is not up in step S02, the target combination weight used for the combination calculation is “first target combination weight” obtained by adding “adhesion correction amount” (= “set target combination weight” + “insertion”. Eye "+" adhesion correction amount ") (step S03), the combination weighing operation is executed using this" first target combination weight "(step S04), the adhesion correction timer is decremented (step S05), and step S02 Return to.

  In this way, for a certain time from the start of operation until the adhesion correction timer expires, the “first target” obtained by adding the above “adhesion correction amount” is assumed that the object to be weighed adheres to the weighing hopper 9. The combination calculation is performed using the “combination weight”.

  When the fixed time elapses and the adhesion correction timer expires in step S02, the target combination weight is not added from the "first target combination weight" to the "second target combination weight" (= (Set target combination weight) + “joint”) (step S06), and thereafter, the combination weighing operation is executed using the “second target combination weight” (step S07).

  Thus, the combination weighing operation with the first target combination weight added with the “adhesion correction amount” is performed for a certain period of time from the start of operation until the adhesion of the object to be measured is stabilized, and the certain period of time has elapsed. After the adhesion is stabilized, the combination weighing operation is performed with the second target combination weight without adding the “adhesion correction amount”. Therefore, after the object to be weighed on the weighing hopper 9 is stabilized, the target combination is unnecessarily necessary. The combination calculation is performed without increasing the weight, and the yield is improved as compared with the conventional example.

  The operation start that is the starting point of a certain time for determining whether or not the object to be weighed is stably attached to the weighing hopper 9 is the operation start in a state in which the object to be weighed is not attached to the weighing hopper 9. This is the start of operation after the start of operation at the start of work and after washing for switching the type of the object to be weighed.

  Therefore, when the operation is temporarily stopped after the operation is started and the operation is resumed without washing, the operation does not correspond to the operation start and the state before the operation is stopped is continued.

  In order to clearly distinguish this operation start, a start operation start switch that executes the processing of FIG. 3 from the beginning and a normal operation start switch that continues from the state before the operation stop may be provided separately. .

  FIG. 4 is a flowchart corresponding to FIG. 3 of another embodiment of the present invention.

  In the above embodiment, when a certain time has elapsed from the start of operation and the adhesion correction timer has expired, it is determined that the adhesion of the object to be weighed to the weighing hopper 9 hardly progresses and the adhesion amount is stable, and the target combination Although the weight is changed from the first target combination weight to the second target combination weight, in this embodiment, whether or not the amount of the object to be weighed on the weighing hopper 9 is stabilized based on the zero point fluctuation at the time of zero point correction. Judgment is made.

  That is, when there is almost no zero point fluctuation amount and the zero point is stable, it is determined that there is almost no progress of attachment of the object to be weighed to the weighing hopper 9, and the target combination weight is changed from the first target combination weight to the second. The target combination weight is changed.

  First, when the operation is started in a state where an object to be weighed is not attached to the weighing hopper 9, the “first target combination weight” (the “adhesion correction amount”) is added to the target combination weight used for the combination calculation ( = “Set target combination weight” + “sealing” + “adhesion correction amount”) (step S101), the combination weighing operation is executed using this “first target combination weight” (step S102), and zero point correction is performed. The zero value is stored (S103), and it is determined whether or not the zero value is stabilized from the zero fluctuation amount which is the difference between the zero value at the time of the current zero correction and the zero value at the time of the previous zero correction. (Step S104). Specifically, when the difference between the zero value at the current zero correction and the zero value at the previous zero correction is equal to or less than the threshold value, it is determined that the value is stable.

  If it is determined in step S104 that the value of the zero point is not stable, that is, the adhesion of the object to be weighed to the weighing hopper 9 has progressed and the amount of adhesion is not stable, the process returns to step S102, The combination calculation using “1 target combination weight” is continued.

  When it is determined in step S104 that the zero value is stable, it is determined that the adhesion of the object to be weighed to the weighing hopper 9 is almost eliminated and the amount of adhesion is stable, and based on the amount of zero fluctuation until then. The “adhesion correction amount” is calculated and displayed, and updated and stored as the “adhesion correction amount” at the start of the next luck point (step S105), and the process proceeds to step S106. This “adhesion correction amount” may be obtained by multiplying the average value of the number of weighing hoppers 9 selected as an appropriate amount combination in the most recent combination calculation by the accumulated value of the zero point fluctuation amount as described above. Furthermore, it is good also as what multiplied the coefficient.

  In step S106, the target combination weight is changed from “first target combination weight” to “second target combination weight” (= “set target combination weight” + “joint”) in which “adhesion correction amount” is not added. (Step S106) and thereafter, the combination weighing operation is executed using the “second target combination weight” (Step S107).

  In this way, the first target combination weight is changed to the second target combination weight based on the zero point fluctuation amount that fluctuates according to the amount of adhesion to the weighing hopper 9, so that when a certain time has elapsed from the start of operation. Compared with the embodiment in which the first target combination weight is changed to the second target combination weight, the target combination weight is switched and changed at an appropriate time in accordance with the state of the object to be weighed on the weighing hopper 9. be able to.

(Other embodiments)
The present invention can also be implemented in the following forms.

  (1) In the above embodiment, the target combination weight is switched in two stages of the first target combination weight and the second target combination weight. However, the target combination weight may be switched in three or more stages.

  (2) In the embodiment of FIG. 4, when it is determined that the zero value is stable, the adhesion correction amount based on the zero value is calculated, and the value is displayed on the operation setting display unit 23, and The adhesion correction amount is updated and stored as the adhesion correction amount at the start of the next operation. For simplicity, the adhesion correction amount displayed on the operation setting display unit 23 is input and set by the operator each time the operation is started. May be.

  (3) In each of the above embodiments, in the initial stage of operation in which the object to be weighed adheres to the weighing hopper 9, the combination calculation is performed using the first target combination weight added with the “adhesion correction amount”. However, as another embodiment of the present invention, the “adhesion correction amount” and, therefore, the “first target combination weight” may be changed according to the zero point fluctuation amount obtained by the zero point correction.

  That is, instead of setting the “adhesion correction amount”, the zero point fluctuation amount, which is the difference between the zero point of the previous zero point correction and the zero point of the current zero point correction, which is obtained each time zero correction is performed, is input to the weighing hopper 9. The above-mentioned “adhesion correction amount” is obtained by multiplying the zero point fluctuation amount by the average value of the number of the weighing hoppers 9 selected as an appropriate amount combination by the combination calculation. .

  This zero point fluctuation amount may be, for example, the zero point fluctuation amount of one weighing hopper 9 or an average value of the zero point fluctuation amounts of a plurality of weighing hoppers 9.

  According to this, every time the zero point fluctuation amount is obtained by the zero point correction, the zero point fluctuation amount is multiplied by the average value of the number of the weighing hoppers 9 selected as an appropriate amount combination to obtain the “adhesion correction amount”. This is updated by replacing the “adhesion correction amount” up to.

  At the time of the first zero correction, there is no previous zero correction, so the value included as the amount of adhesion of the object to be weighed is set as the `` adhesion correction amount '' in the setting of the conventional `` joint ''. The “adhesion correction amount” is used.

  According to this configuration, since the zero point fluctuation amount corresponding to the adhesion amount of the object to be weighed is set as the “adhesion correction amount” at the initial stage of operation in which the adhesion of the object to be weighed to the weighing hopper 9 proceeds, ”Is in line with the actual adhesion amount of the object to be measured, the first target combination weight is not unnecessarily increased, the yield can be further improved, and the“ adhesion correction amount ”is set in advance. There is no need to keep it.

2 Main feeder 5 Linear feeder 8 Supply hopper 9 Weighing hopper 10 Weight sensor 11 Control device 17 CPU unit 23 Operation setting display unit

Claims (7)

A combination weigher comprising a plurality of weighing hoppers to which objects to be weighed are supplied,
Combination calculation means for performing combination calculation for selecting a combination of weighing hoppers to discharge the objects to be weighed based on the weights of the objects to be weighed supplied to the respective weighing hoppers and the target combination weight;
Determination means for determining whether or not the amount of the object to be weighed on the weighing hopper is stable;
Zero point correction means for correcting the zero point of the weighing hopper,
The combination calculation means changes the target combination weight to a target combination weight smaller than the target combination weight when the determination means determines that the adhesion amount is stable.
A combination weigher characterized by that. The determination means determines whether or not the adhesion amount is stable based on an elapsed time from the start of operation.
The combination weigher according to claim 1. The determination unit determines whether or not the adhesion amount is stable based on a zero point fluctuation amount obtained by the zero point correction by the zero point correction unit.
The combination weigher according to claim 1. The small target combination weight is set as the second target combination weight, the target combination weight before changing to the second target combination weight is set as the first target combination weight, and the second target combination weight is calculated from the first target combination weight. An adhesion correction amount setting means for setting the adhesion correction amount when the weight obtained by subtracting is used as the adhesion correction amount,
The combination weigher according to any one of claims 1 to 3. Informing means for informing the zero point fluctuation amount obtained by the zero point correction by the zero point correcting means,
The combination weigher according to claim 4. When the small target combination weight is set as the second target combination weight, and the target combination weight before changing to the second target combination weight is set as the first target combination weight, the combination calculation means is configured to output the first target combination weight. The combination weight is changed according to the zero point fluctuation amount obtained by the zero point correction by the zero point correction means.
The combination weigher according to any one of claims 1 to 3. The combination calculation means obtains a change amount of the first target combination weight by multiplying the zero point fluctuation amount by an average value of the number of weighing hoppers selected in the combination calculation.
The combination weigher according to claim 6.

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