JP4833658B2 - Combination weighing device - Google Patents

Description

  The present invention relates to a combination weighing device that puts a weighed object into a packaging machine or the like.

  Conventionally, in a combination weighing device, objects to be weighed such as detergents and confectionery are supplied to, for example, a plurality of weighing hoppers, and a combination operation is performed based on a weight measurement value of the objects to be weighed supplied to the weighing hopper. The combination of the weighing hoppers in which the total of the weighing values is within a predetermined weight range is obtained. Then, the objects to be weighed in the weighing hopper corresponding to the combination are discharged together, for example, the objects to be weighed are put into a packaging machine and packed in a bag by the packaging machine.

  In such a combination weighing device, it is well known that when the number of measurement values used in the combination calculation is increased, the number of combinations is increased and the measurement accuracy can be improved. Moreover, in order to suppress the enlargement of the apparatus and increase the number of measurement values, a combination weighing apparatus including a plurality of storage chambers in one hopper has been proposed (see, for example, Patent Document 1).

  For example, a weighing hopper 6 having a plurality of weighing units, each of which has two storage chambers 6a and 6b capable of individually discharging the objects to be weighed, as shown in FIG. In the combination weighing apparatus including the memory hopper 8 having the two storage chambers 8a and 8b capable of individually discharging the objects to be weighed, weighing is performed for one weighing unit in combination calculation. A maximum of four measurement values (measurement values of the weights of the objects to be weighed supplied to the four storage chambers 6a, 6b, 8a, 8b) can be obtained as values. When eight weighing units are provided, a maximum of 32 weighing values can be used for the combination calculation, and the weighing accuracy can be improved.

In this case, for example, the number of combinations that can be combined using 32 measurement values becomes very large, and enormous calculation time is required to perform the combination calculation, which hinders the operation speed of the combination weighing device and is practical. is not. Therefore, there is a method of limiting the number of measurement values used for the combination calculation. For example, in a combination weighing device having eight weighing units described above, numbers are assigned to each weighing unit in order from No. 1 to No. 8, and the weighing values of the weighing units from No. 1 to No. 4 are first calculated. The combination calculation is performed using the measurement values of the weighing units from No. 5 to No. 8, and the combination calculation is performed using the measurement values of all the weighing units. There is a method of performing combination calculation using weighing units up to a certain number.
JP-A-4-118528

  However, as described above, when the weighing values used for the combination calculation are selected in the order of the numbers of the weighing units, the weighing values are not selected in consideration of the weighing accuracy. Therefore, there is room for improvement in order to improve the weighing accuracy.

  The present invention has been made to solve the above-described problems, and shortens the time required for the combination calculation when the time required for the combination calculation exceeds the desired time when all the measurement values are used for the combination calculation. An object of the present invention is to provide a combination weighing device that can improve the weighing accuracy.

  In order to solve the above-described problems, the combination weighing device of the present invention includes a plurality of storage chambers that hold and discharge the objects to be supplied, and the weights of the objects to be weighed held in the storage chambers. By performing the combination calculation using the measured value, the total measured value of the weight of the object to be weighed is within the allowable range with respect to the target weight value, and the absolute value of the difference from the target weight value is minimized. A combination calculation means for obtaining one combination of the storage chambers, and a control means for discharging an object to be weighed to the storage chamber of the combination obtained by the combination calculation means, wherein the combination calculation means includes: The maximum number n of measurement values used in the combination calculation is determined in advance, and a value obtained by dividing the target weight value by a divisor consisting of an arbitrary integer value is used as a reference candidate value, and the number of measurement values equal to or greater than the reference candidate value is m or more { Is n / 2 when n is even and (n−1) / 2 or (n + 1) / 2 when n is odd} and the number of metric values less than the reference candidate value is Among the divisors determined so that there are (n−m) or more, the reference candidate value corresponding to the divisor that minimizes the absolute value of the difference from n / 2 is obtained as a reference value, and Prior to selecting m measurement values that are greater than or equal to a reference value and having a small absolute value of the difference from the reference value, the absolute value of the difference from the reference value is smaller than the reference value. It is configured to perform a measurement value selection process that selects (n−m) measurement values with priority, and to perform the combination calculation using a total of n measurement values selected by the measurement value selection process. ing.

  According to this configuration, for example, when the combination calculation is performed using the measurement values corresponding to all the storage rooms (the number of measurement values greater than n), the time required for the combination calculation exceeds the desired time. By determining the number n so that the time required for the combination calculation using the measurement value is within the desired time, the time required for the combination calculation can be shortened within the desired time. The absolute value of the difference from the value of n / 2 among the divisors determined so that there are the same or approximately the same number of measurement values before and after the reference candidate value as n measurement values used in the combination calculation The reference candidate value corresponding to the divisor that minimizes is obtained as a reference value, and the same or approximately the same number of measured values before and after the reference value are selected. Here, the divisor corresponding to the reference candidate value that has become the reference value is the planned number of measurement values selected by the combination, and n / 2 or n / 2 for n measurement values used for the combination calculation. Since the closest possible number is set as the planned selection number, the number of combinations can be increased, and the same or approximately the same number of measurement values before and after the reference value are selected and used as n measurement values for combination calculation. Therefore, a combination within the allowable range can be easily obtained, and the measurement accuracy can be improved.

  Further, the combination calculation means sets the divisor used in the measurement value selection process to be P or more (P is a predetermined integer value of 2 or more) and Q or less {Q is n / 2 when n is an even number. And when n is an odd number, an arbitrary integer value within a range of (n−1) / 2 or (n + 1) / 2} is set, and a combination process including the measurement value selection process and the combination calculation is performed. When repeatedly performing the combination process, the measurement value selection process of the combination process to be performed later is obtained by the previous combination process in any combination r times (r is a plurality). It is configured to use a weight value of an object to be weighed supplied to the storage chamber that does not belong to a combination, and the control means performs the combination every time the combination processing by the combination calculation means is performed. Belonging to May be each other is configured such that the order from the storage chamber to discharge the objects to be weighed that.

  According to this configuration, the combination processing is performed r times during one operation cycle time (one weighing cycle time), the object to be weighed can be discharged r times, and a high-speed discharging operation is possible. . When r = 2, a so-called double shift operation is performed, and when r = 3, a so-called triple shift operation is performed.

In the measurement value selection process, when the divisor is the value of P, the combination calculation means determines that the value of the measurement value is not more than m as many as the reference candidate values. select the n weighing in favor of larger, in the absence number of weighing values below the reference candidate value (n-m) or more is giving priority to those values of the metric value is small n It may be configured to select individual weighing values.

  The present invention has the above-described configuration, and in the combination weighing device, when all the measurement values are used for the combination calculation, the time required for the combination calculation is shortened when the time required for the combination calculation exceeds the desired time. And the measurement accuracy can be improved.

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

  FIG. 1 is a schematic diagram showing the configuration of a combination weighing device according to an embodiment of the present invention. FIG. 2A is a schematic view of the supply hopper, the weighing hopper, and the memory hopper of the combination weighing device as viewed from the outside front, and FIG. 2B is a side view of the supply hopper, the weighing hopper, and the memory hopper. It is the schematic diagram seen from.

  In the present embodiment, a supply device 1 for supplying an object to be weighed to the combination weighing device is provided as a preceding device of the combination weighing device, and an object to be weighed in combination as a latter device of the combination weighing device. A packaging machine 20 is provided. The supply device 1 is a trough (trough: large slender container) to which a vibrator 1a is attached. An object to be weighed is supplied to the trough from another device (not shown), and the trough is appropriately vibrated by the vibrator 1a. As a result, the objects to be weighed are sent out onto the dispersion feeder 3 of the combination weighing device.

  In this combination weighing device, a conical dispersion feeder 3 having a vibrator 3 a is provided in the center of the upper portion of the device, and an amount of an object to be weighed on the dispersion feeder 3 is detected above the dispersion feeder 3. In addition, for example, an ultrasonic level sensor 2 is provided. The dispersion feeder 3 disperses the objects to be weighed supplied from the supply device 1 radially by the vibration of the vibrator 3a. Around the dispersion feeder 3, a plurality of rectilinear feeders 4 provided with vibrators 4a are provided radially. Each rectilinear feeder 4 sends the objects to be weighed sent from the dispersion feeder 3 to each supply hopper 5 by the vibration of the vibrator 4a. A supply hopper 5 is provided on the delivery side of each object to be weighed in each linear feeder 4, and a weighing hopper 6 having two storage chambers is provided below each supply hopper 5. Each weighing hopper 6 is provided with a weight sensor 7 such as a load cell, and the weight sensor 7 measures the weight of an object to be weighed in each storage chamber of the weighing hopper 6. A memory hopper 8 having two storage chambers is provided obliquely below each weighing hopper 6. A plurality of weighing units including the linear feeder 4, the supply hopper 5, the weighing hopper 6, the memory hopper 8, and the weight sensor 7 are provided, and below each of the linear feeders 4, the supply hopper 5, The weighing hopper 6 and the memory hopper 8 are provided corresponding to each other, and each is arranged in a circle. Further, below the weighing hopper 6 and the memory hopper 8, there is provided a collecting chute 9 for collecting the objects to be weighed discharged from these hoppers and discharging them from the lower discharge port. In addition, a collective funnel 10 is disposed at a discharge port below the collective chute 9. It can be said that the collecting funnel 10 constitutes a part of a collecting chute for collecting the objects to be weighed discharged from the weighing hopper 6 and the memory hopper 8 and discharging them to the packaging machine 20. The objects to be weighed discharged from the weighing hopper 6 and the memory hopper 8 onto the collecting chute 9 are fed into the packaging machine 20 through the collecting funnel 10. In the packaging machine 20, for example, while manufacturing a bag, the bag is filled with an object to be weighed supplied from a combination weighing device and packaged.

  Further, as shown in FIGS. 2A and 2B, each weighing hopper 6 has two storage chambers 6a and 6b to which objects to be weighed are supplied, and each memory hopper 8 has a weighing hopper. There are two storage chambers 8a and 8b corresponding to six weighing chambers 6a and 6b. Hereinafter, the storage chamber of the weighing hopper is referred to as a weighing chamber, and the storage chamber of the memory hopper is referred to as a memory chamber. The two weighing chambers 6a and 6b of each weighing hopper 6 are arranged side by side in substantially the same direction as the arrangement direction (rowing direction) of the plurality of weighing hoppers 6, and the two memory chambers 8a and 8b of each memory hopper 8 are plural. The memory hoppers 8 are arranged side by side in substantially the same direction as the arrangement direction (row arrangement direction).

  The supply hopper 5 is provided with two gates 51 and 52 that can be driven independently, and by opening each gate, the object to be weighed can be selectively discharged to the weighing chamber 6a and the weighing chamber 6b. . When the gate 51 is opened, the object to be weighed is discharged to the weighing chamber 6b, and when the gate 52 is opened, the object to be weighed is discharged to the weighing chamber 6a.

  The weighing hopper 6 is provided with two gates 61 and 62 that can be independently driven in the respective weighing chambers 6a and 6b. By opening each gate, an object to be weighed can be separately provided from each weighing chamber 6a and 6b. In this configuration, the collective chute 9 and the memory hopper 8 can be selectively discharged to the corresponding memory chambers 8a and 8b. When the gate 61 of the weighing chamber 6a is opened, the objects to be weighed are discharged onto the collecting chute 9, and when the gate 62 of the weighing chamber 6a is opened, the objects to be weighed are discharged to the memory chamber 8a of the memory hopper 8. Similarly, when the gate 61 of the weighing chamber 6b is opened, the objects to be weighed are discharged onto the collecting chute 9, and when the gate 62 of the weighing chamber 6b is opened, the objects to be weighed are discharged to the memory chamber 8b of the memory hopper 8. .

  The memory hopper 8 has a configuration in which a gate 81 is provided in each of the memory chambers 8a and 8b, and the objects to be weighed can be separately discharged onto the collecting chute 9 from each of the memory chambers 8a and 8b by opening each gate. .

  FIG. 3 is a block diagram showing an outline of a control system of the combination weighing device according to the present embodiment.

  The control unit 16 includes a combination calculation unit and a control unit, and includes a calculation control unit 161 including a CPU and a storage unit 162 including a memory such as a RAM and a ROM. The storage unit 162 stores an operation program, a number of operation parameter data that are operation setting data, other measurement value data, and the like. The calculation control unit 161 executes the operation program stored in the storage unit 162 to control the entire supply device 1 and the combination weighing device and perform combination processing including combination calculation. In addition, the arithmetic control unit 161 controls the vibration control drive circuit 12 so as to keep the object to be weighed on the dispersion feeder 3 at a constant amount based on the signal of the level sensor 2 input via the I / O circuit 15. The operation of the vibrator 1a of the supply device 1 is controlled via Further, the operation of the vibrator 3 a of the distributed feeder 3 and the vibrator 4 a of each linear feeder 4 is controlled via the vibration control drive circuit 12. Further, the gate opening / closing devices 5A, 6A, 8A of the supply hopper 5, the weighing chambers 6a, 6b of the weighing hopper 6 and the memory chambers 8a, 8b of the memory hopper 8 are connected via the gate drive circuit 14 (for example, pulse motors). ) Control the operation. Further, the measurement value of each weight sensor 7 is received via the A / D conversion circuit 13. In addition, a signal is input from the operation setting display 17 and a signal such as data to be displayed on the operation setting display 17 is output. Reference numeral 18 denotes a gate opening / closing device corresponding to one weighing unit.

  In the arithmetic control unit 161, combination processing including combination calculation is performed, and a total sum of measured values of the objects to be weighed is determined from the weighing chambers 6a and 6b of the plurality of weighing hoppers 6 and the memory chambers 8a and 8b of the memory hopper 8. One storage chamber combination (discharge combination) within the weight range (allowable range for the target weight value) is obtained. In this combination processing, the weighing value of the weighing object calculated based on the weight measurement value by the weight sensor 7 is used as the weighing value of the weighing object in the weighing chambers 6 a and 6 b of the weighing hopper 6. In each weighing hopper 6, when the object to be weighed is supplied only to one of the two weighing chambers 6a and 6b, for example, the weighing chamber 6a, the weight of the object to be weighed in the weighing chamber 6a is heavy. It is measured by the sensor 7. Further, when an object to be weighed is supplied to the other weighing chamber 6b, the total weight of the objects to be weighed in the two weighing chambers 6a and 6b is weighed by the weight sensor 7. In the arithmetic and control unit 161, the weighing chamber 6b is subtracted from the total weight of the weighing objects in the two weighing chambers 6a and 6b by subtracting the measured value of the weighing object in the weighing chamber 6a previously measured. Calculate the measurement value of the object to be weighed. When an object to be weighed is supplied from the weighing chambers 6a and 6b of the weighing hopper 6 to the memory chambers 8a and 8b of the memory hopper 8, the calculation control unit 161 measures and calculates in the weighing chambers 6a and 6b of the weighing hopper 6. The weighing value of the weighing object at that time is recognized as the weighing value of the weighing object supplied to the memory chambers 8a and 8b of the memory hopper 8. The weighing values of the objects to be weighed held in the weighing chambers 6 a and 6 b of the weighing hopper 6 and the memory chambers 8 a and 8 b of the memory hopper 8 are stored in the storage unit 162. Further, as shown in FIG. 1, the calculation control unit 161 of the control unit 16 receives a discharge command signal from the packaging machine 20 via the I / O circuit 15, and selects a discharge combination based on the discharge command signal. A discharging operation for discharging the object to be weighed from the storage chamber is performed. Details of the combination process for obtaining the discharge combination will be described later.

  The operation setting display 17 includes, for example, a touch screen display, and can perform operations such as start and stop of the combination weighing device on the screen. Further, the operation parameters of the combination weighing device can be set by switching the display screen, and the set operation parameter values are stored in the storage unit 162 via the arithmetic control unit 161. During operation, the operation status such as the operation speed of the combination weighing device and the combination processing result is usually displayed.

  First, an outline of the operation of the combination weighing device of the present embodiment configured as described above will be described. The operations of the supply device 1 and the combination weighing device are realized by the control of the control unit 16.

  First, an object to be weighed is conveyed above the combination weighing device by the feeding device 1 and placed on the dispersion feeder 3. Then, the objects to be weighed are sent to the supply hoppers 5 that are radially dispersed by the vibration of the dispersion feeder 3 and arranged in a plurality of circles via the linear feeder 4 that follows the dispersion feeder 3. When the weighing chambers 6 a and 6 b of the weighing hopper 6 positioned below the supply hoppers 5 are empty, the objects to be weighed in the supply hoppers 5 are supplied to the weighing chambers 6 a and 6 b of the weighing hoppers 6. At this time, the object to be weighed is supplied to only one of the measuring chambers in one supply of the supply hopper 5. The object to be weighed is supplied to the weighing chamber 6b by opening and closing one gate 51 of the supply hopper 5, and the object to be weighed is supplied to the weighing chamber 6a by opening and closing the other gate 52. Further, when the memory chambers 8a and 8b of the memory hopper 8 corresponding to the weighing chambers 6a and 6b of each weighing hopper 6 are empty, the memory hopper discharge gates 62 of the weighing chambers 6a and 6b are opened and closed. Thus, the objects to be weighed are supplied to the memory chambers 8a and 8b of the memory hopper 8.

  The control unit 16 determines the discharge combination of the storage chamber in which the objects to be weighed should be discharged by performing the combination process, and, for example, based on the discharge command signal from the packaging machine 20, the control unit 16 removes the objects to be measured from the discharge combination storage chamber. It is discharged onto the collecting chute 9. At this time, in the memory chambers 8 a and 8 b of the memory hopper 8, the objects to be weighed are discharged by opening and closing the respective gates 81. In the weighing chambers 6 a and 6 b of the weighing hopper 6, the respective collecting chute discharging gates are discharged. The object to be weighed is discharged by opening and closing 61. The objects to be weighed slide down on the collecting chute 9, pass through the collecting funnel 10 and are discharged to the packaging machine 20. In the packaging machine 20, for example, while manufacturing a bag, the bag is filled with an object to be weighed discharged from the combination weighing device and packaged.

  Here, an example of the operation of a certain weighing unit will be described. Here, let us consider a state where an object to be weighed is supplied to all of the weighing chambers 6a and 6b of the supply hopper 5, the weighing hopper 6, and the memory chambers 8a and 8b of the memory hopper 8 in one weighing unit. From this state, when one storage chamber, for example, the memory chamber 8a is selected as the discharge combination and the object to be weighed is discharged and emptied by the combination processing, immediately after that, the object to be weighed is transferred from the weighing chamber 6a to the memory chamber 8a. While being supplied, an object to be weighed is supplied from the supply hopper 5 to the measuring chamber 6a. In this case, after the stable time of the weight sensor 7 has elapsed after the weighing object is supplied, the weighing value in the weighing chamber 6a is weighed, and then the measured value can be used for the combination calculation. When the corresponding weighing chamber 6a and the memory chamber 8a are selected as the discharge combination and the weighing object is discharged and emptied, the weighing object is supplied from the supply hopper 5 to the weighing chamber 6a. At this time, the memory chamber 8a remains empty, and the metering chamber 6a to the memory chamber 8a is not inspected until one metering cycle time (one metering cycle time Tw; see FIGS. 6A and 6B) has not elapsed. Weighing items are not supplied. In addition, when the weighing chamber 6a and the memory chamber 8b which are not corresponding to each other are selected as the discharge combination and the object to be weighed is discharged and becomes empty, the object to be weighed is supplied from the weighing chamber 6b to the memory chamber 8b. An object to be weighed is supplied from the hopper 5 to the weighing chamber 6a. At this time, the weighing chamber 6b is emptied, and the weighing object is not supplied from the supply hopper 5 to the weighing chamber 6b unless one weighing cycle time has elapsed. Further, when both of the two weighing chambers 6a and 6b are selected as the discharge combination and the object to be weighed is discharged and emptied, immediately after that, one of the two weighing chambers 6a and 6b is weighed from the supply hopper 5. The object to be weighed is supplied to the chamber. At this time, the other weighing chamber remains empty, and the weighing object is not supplied from the supply hopper 5 to the other weighing chamber unless one weighing cycle time has elapsed. It is determined in advance which of the two empty measuring chambers 6a and 6b is supplied from the supply hopper 3 to the weighing chamber. As described above, the supply of the object to be weighed from the supply hopper 5 to the weighing hopper 6 is performed only once to one weighing chamber (6a, 6b) which is empty every one weighing cycle time.

  Next, the combination processing in the present embodiment will be described in detail. FIG. 4 is a flowchart showing combination processing by the control unit 16 in the present embodiment. Here, the combination weighing device includes, for example, twelve weighing units. In this case, there are four weighing values corresponding to the weighing chambers 6a and 6b of the weighing hopper 4 and the memory chambers 8a and 8b of the memory hopper 5 for each weighing unit. Since they are arranged, it is possible to use a total of 48 measurement values at the maximum for the combination calculation. However, if the combination calculation is performed using all the measurement values that can be used for the combination calculation, the calculation takes a long time and high-speed operation cannot be performed. Therefore, in the present embodiment, the number of measurement values used for the combination calculation (hereinafter referred to as “number of used measurement values”) is limited to n or less, and the combination calculation is performed. The number n of used measurement values is smaller than the number of measurement values corresponding to all the storage chambers (the aforementioned 48), and the time required to perform the combination calculation using the n measurement values is a combination weighing device. The value is determined in advance in consideration of the performance of the CPU used for the arithmetic control unit 161 so as to be within a desired time without lowering the operation speed. In addition, in FIG. 4, the flowchart in case the number n of used measurement values is an even number is shown.

  Note that the measurement value (hereinafter referred to as “effective measurement value”) that can be used for the combination calculation is a measurement value that has been measured for the objects to be measured held in the measurement chambers 6a and 6b and the memory chambers 8a and 8b. The measured value (for example, 0.0 g) when not measured (including during measurement) or empty when the object to be weighed is not held is not included.

  First, in step S1, it is determined whether or not the number of effective measurement values is larger than the number n of used measurement values. If the number of use measurement values is n or less, the process proceeds to step S8 and all effective measurement values are combined and calculated. Select the measurement value to be used for. Then, the process proceeds to step S7, where the combination calculation is performed based on the measurement value selected in step S8, and the total of the measurement values is within a predetermined weight range (allowable range with respect to the target weight value) and the difference from the target weight value is determined. One storage room combination having the smallest absolute value is obtained and determined as a discharge combination. When the number of effective measurement values is less than or equal to the number of used measurement values n, it occurs mainly at the start of operation or the like, and usually exceeds the number of use measurement values n during continuous operation.

  If the number of effective weighing values is larger than the number n of used weighing values, the process proceeds to step S2 to create a weighing value table in which the effective weighing values are arranged in the order of weight (heavy order or light order).

  FIG. 5 (a) is a diagram showing an example of measured values of the objects to be weighed held in the respective weighing chambers 6a and 6b and the memory chambers 8a and 8b of the twelve weighing units in the present embodiment. FIG. 5B is an example of the measurement value table created in step S2, and is a diagram showing the measurement value table created based on the measurement values shown in FIG. In FIG. 5A, the weighing chamber 6a of the first weighing unit is WB1a, the weighing chamber 6b of the first weighing unit is WB1b, the weighing chamber 6a of the second weighing unit is WB2a, and the weighing chamber 6b of the second weighing unit is WB2b. , ..., the weighing chamber 6a of the twelfth weighing unit is shown as WB12a, and the weighing chamber 6b of the twelfth weighing unit is shown as WB12b. Similarly, the memory chamber 8a of the first weighing unit is MB1a, the memory chamber 8b of the first weighing unit is MB1b, the memory chamber 8a of the second weighing unit is MB2a, the memory chamber 8b of the second weighing unit is MB2b,. The memory chamber 8a of the twelfth weighing unit is denoted as MB12a, and the memory chamber 8b of the twelfth weighing unit is denoted as MB12b. The notation in parentheses indicates the measurement value of the object to be weighed in each storage chamber, and the measurement value in the measurement chambers 6a and 6b (WBxa, WBxb; x = 1 to 12) of the measurement hopper 6 is expressed as 0.0 g. If the measured value is not measured, the measured value in the memory chambers 8a and 8b (MBxa, MBxb; x = 1 to 12) of the memory hopper 8 is indicated as 0.0 g. , Indicates that the object to be weighed is not supplied. These measurement values (0.0 g) are not measurement values that can be used for the combination calculation, and are not included in the effective measurement values.

  FIG. 5B shows a measurement value table that is created based on the data shown in FIG. 5A and in which the effective measurement values are arranged in descending order. The number of effective measurement values is 22. The data in FIG. 5A and the measurement value table created in step S2 in FIG. 5B are stored in the storage unit 162. Note that the measurement value table may be created by arranging effective measurement values in a lighter order rather than in a heavy order.

  Next, in step S3, the divisor x is set to a value of n / 2 (1/2 of the used measurement value number n), and the repetition count k is set to 1.

  Next, in step S4, a value obtained by dividing the target weight value by x is obtained as a reference candidate value.

  Next, in step S5, with reference to the measurement value table created in step S2, there are n / 2 or more effective measurement values greater than or equal to the reference candidate value and n / 2 effective measurement values less than the reference candidate value. It is determined whether or not there are more than one.

  If it is determined as Yes in step S5, the process proceeds to step S6, where the reference candidate value is set as the reference value, and the measurement value table is referred to and the absolute value of the difference from the reference value is small with reference to the measurement value table. Priority is given to n / 2 effective weighing values, and n / 2 effective weighing values are combined to give priority to those that are less than the reference value and have a small absolute difference from the reference value. Select the measurement value to be used for. And it progresses to step S7 and performs the above-mentioned combination calculation based on the measured value selected at step S6, and calculates | requires discharge | emission combination.

  When it is determined No in step S5, the process proceeds to step S9, and it is determined whether or not the number of repetitions k is the set number A. If the number of repetitions k is not the set number of times A, the process proceeds to step S10, the value of the divisor x is decreased by 1 and the value of the number of repetitions k is increased by 1, and the processing from step S4 is repeated. If the number of repetitions k is the set number A, the process proceeds to step S11.

  In step S11, it is determined by referring to the measurement value table whether there are n / 2 or more effective measurement values less than the reference candidate value. If there are n / 2 or more effective measurement values less than the reference candidate value, the process proceeds to step S12, and the n most effective measurement values in order from the heaviest one to the measurement value to be used for the combination calculation are referred to the measurement value table. The combination is calculated (step S7). Here, n / 2 or more effective weighing values less than the reference candidate value means that there are few heavy effective weighing values, so that a predetermined weight range by combination calculation is selected by preferentially selecting from the heavy ones. It becomes easy to make a combination. If there are no n / 2 or more effective measurement values less than the reference candidate value, that is, less than n / 2, the process proceeds to step S13, and the n lightest values are sequentially checked with reference to the measurement value table. The effective weighing value is selected as the weighing value used for the combination calculation, and the combination calculation is performed (step S7). Here, the fact that there are less than n / 2 effective weighing values less than the reference candidate value means that there are few light effective weighing values. It becomes easy to make combinations within the range.

  In step S11, it is determined whether or not there are n / 2 or more effective metric values less than the reference candidate value. However, there are n / 2 or more effective metric values greater than or equal to the reference candidate value. It may be determined whether or not. In this case, if there are n / 2 or more effective metric values greater than the reference candidate value, the process proceeds to step S13, and if not, the process proceeds to step S12.

  Next, for example, a case where the number n of used measurement values is 14, the target weight value is 100 g, the set number of times A is set to 3, and the measurement value table of FIG. 5B is created in step S2 will be described. To do. In this case, among the measurement values shown in FIG. 5A, there are 26 measurement values (0.0 g) that are not used for the combination calculation, and the total number of effective measurement values is 22. .

  In step S3, n / 2 is set to the divisor x, and 1 is set to the number of repetitions k. Here, since n is 14, x = 7.

  Next, in step S4, the reference candidate value becomes 14.3 g by dividing 100 g of the target weight value by x (= 7).

  Next, referring to the measurement value table of FIG. 5B in step S5, there are 0 effective measurement values less than 14.3 g of the standard candidate value, and there are n / 2, that is, no more than 7 effective measurement values. The process proceeds to step S9. Since the current k is 1 and is not 3, which is the set number of times A, the process proceeds to step S10. In step S10, the value of x is decreased by 1 and set to 6, the value of k is increased by 1 and set to 2, and the process returns to step S4.

  Next, in the second step S4, the reference candidate value becomes 16.7 g by dividing the target weight value of 100 g by x (= 6).

  Next, referring to the measurement value table in FIG. 5B in the second step S5, there are three effective measurement values less than 16.7 g of the standard candidate value, and n / 2, that is, seven or more. Since it does not exist, the process proceeds to step S9. Since the current k is 2 and not 3 of the set number A, the process proceeds to step S10. In step S10, the value of x is decreased by 1 and set to 5, the value of k is increased by 1 and set to 3, and the process returns to step S4 again.

  Next, in the third step S4, the reference candidate value becomes 20.0 g by dividing the target weight value of 100 g by the divisor x (= 5).

  Next, referring to the measurement value table of FIG. 5B in the third step S5, there are n / 2 effective measurement values of 20.0 g or more of the standard candidate values, that is, 7 or more, and 20 Since there are seven or more effective weighing values less than 0.0 g, the process proceeds to step S6.

  In step S6, 20.0 g of the reference candidate value is used as a reference value, and 20.0 g is selected from effective measurement values of 20.0 g (reference value) or more with reference to the measurement value table of FIG. If seven items are selected with priority given to the absolute value of the difference being small, the measurement values from No. 4 to No. 10 are selected. Further, if seven of the effective weighing values less than 20.0 g are selected with priority given to those having a small absolute value of the difference from 20.0 g, the weighing values from No. 11 to No. 17 are selected. Accordingly, a total of 14 measurement values from No. 4 to No. 17 are selected.

  Next, in step S7, a combination calculation is performed based on the 14 measurement values selected in step S6 to obtain one discharge combination. In this case, the number of measurement values selected for the discharge combination is five, which is the same as the value (5) of the divisor x. That is, it can be said that the divisor x is a planned selection number of measurement values selected for the discharge combination.

In the combination weighing device, since the planned selection number is 2 or more, the divisor x must be 2 or more. Further, the relationship between the divisor x and the number of repetitions k is x = n / 2 when k = 1, x = n / 2−1 when k = 2, and x = n / when k = 3. Since it is 2-2,
x = n / 2−k + 1
Can be shown. Here, since the divisor x is 2 or more, n / 2−k + 1 ≧ 2, and k ≦ n / 2-1. Further, 1 ≦ k. The set number A is set as an integer value within a settable range of k. That is, the set number A is an integer value that is predetermined within a range of 1 or more and (n / 2-1) or less. However, when the set number A is 1, the reference candidate value cannot be changed, so the set number A is preferably 2 or more. In this way, from the point of finding the reference candidate value that satisfies the condition (step S5) that can be changed to the reference value by sequentially changing the reference candidate value, the set number of times A is a large value within the settable range of k (for example, n / 2-1, n / 2-2) is preferable.

  Further, as described above, x = n / 2−k + 1, and the settable range of k is 1 ≦ k ≦ n / 2-1. Here, setting the set number of times A to 3, for example, means that the setting range of k is set to 3 or less (1 ≦ k ≦ 3). This means that the divisor x is 5 when n = 14. The above integer value (5 ≦ x ≦ 7) is used. By setting the set number A, the minimum value used for the divisor x is set.

  Although the case where the number n of used measurement values is an even number has been described above, the case where the number n of used measurement values is an odd number will be described next.

  When n is an odd number, in step S3, instead of setting the value of n / 2 to the divisor x, the value of N {N = (n + 1) / 2 or (n-1) / 2} is set. In step S5, referring to the measurement value table, there are m {m = (n + 1) / 2 or (n-1) / 2} or more effective measurement values greater than or equal to the reference candidate value and less than the reference candidate value. It is determined whether or not there are (n−m) or more effective weighing values, and in step S6, the number of which is greater than or equal to the reference value and whose absolute value of the difference from the reference value is small is given priority. Effective weight values are selected, and (nm) effective weight values are selected with priority given to those that are less than the reference value and have a small absolute value of the difference from the reference value. In step S11, Determine whether there are (nm) or more effective measurement values less than the standard candidate value It may be set to so that.

In this case, the relationship between the divisor x and the number of repetitions k is
x = N−k + 1
Can be shown. Here, since the divisor x is 2 or more, k ≦ N−1. Further, 1 ≦ k. The set number A is set as an integer value within a settable range of k. That is, the set number A is an integer value that is predetermined within a range of 1 or more and (N−1) or less. However, when the set number A is 1, the reference candidate value cannot be changed, so the set number A is preferably 2 or more. In this way, from the point of finding the reference candidate value that satisfies the condition (step S5) that can be changed to the reference value by sequentially changing the reference candidate value, the set number of times A is a large value within the settable range of k (eg N-1 and N-2) are preferred.

  As described above, x = N−k + 1, and the settable range of k is 1 ≦ k ≦ N−1. Here, setting the set number of times A to 3, for example, means that the set range of k is 3 or less (1 ≦ k ≦ 3). This means that when N = (n + 1) / 2 and n = 13, an integer value of 5 or more (5 ≦ x ≦ 7) is used for the divisor x, and N = (n−1) / In the case of 2 and n = 13, an integer value of 4 or more (4 ≦ x ≦ 6) is used for the divisor x. By setting the set number A, the minimum value used for the divisor x is set.

  In the control unit 16, after obtaining the discharge combination by the combination processing, for example, when a discharge command signal is input from the packaging machine 20 via the I / O circuit 15, the gate of the discharge combination storage chamber is opened and the object to be weighed. Is discharged.

  In the combination processing according to the present embodiment, for example, when the combination calculation is performed using the measurement values corresponding to all the storage rooms (the number of effective measurement values greater than n), the time required for the combination calculation exceeds a desired time. The time required for the combination calculation can be shortened within the desired time by determining the number n so that the time required for the combination calculation using the n effective measurement values is within the desired time. it can.

In addition, the number of combinations when selecting y effective weighing values from n effective weighing values is _{n Cy} . When n is an even number, for example, n = 14, ₁₄ C ₈ = 3003, ₁₄ C ₇ = 3432, ₁₄ C ₆ = 3003, and when y = 7 = n / 2, the number of combinations is the largest. Further, when n is an odd number, for example, n = 13, ₁₃ C ₈ = 1287, ₁₃ C ₇ = 1716, ₁₃ C ₆ = 1716, ₁₃ C ₅ = 1287, and y = 7 = (n + 1) / 2 When y = 6 = (n−1) / 2, the number of combinations is the largest. In the combination processing of the present embodiment, among divisors x determined so that there are the same or substantially the same number of effective metric values before and after the reference candidate value, n / 2 or n / 2 as close as possible is planned. Since the divisor x that is the selected number is used, the number of combinations can be increased. In this way, the number of combinations is increased, and the reference candidate value corresponding to the divisor x that is the planned selection number is set as the reference value, and the same or approximately the same number of effective measurement values before and after the reference value are selected. Therefore, combinations within a predetermined weight range are easily obtained. If it becomes easy to obtain a combination within the predetermined weight range, a large number of combinations within the predetermined weight range are obtained, and one of the combinations having the smallest absolute value of the difference between the total effective weight value and the target weight value is selected. Since it is possible to select and determine the discharge combination, it is possible to improve the measurement accuracy.

  In this embodiment, even when the combination weighing device is configured to perform any of so-called single shift operation, double shift operation, and triple shift operation, the combination processing described above may be performed. .

  FIG. 6A is a timing chart when the combination weighing device of the present embodiment is configured to perform a single shift operation, and FIG. 6B is a double shift operation of the combination weighing device of the present embodiment. It is a timing chart at the time of comprising so that.

  One weighing cycle time Tw is, for example, immediately after the discharge combination is determined by the combination processing in the immediately preceding measurement cycle, the object to be weighed is discharged from the storage chamber selected for the discharge combination, and then the discharge is performed. The time (1) required for the object to be weighed to be supplied to the combination storage chamber and for the combination processing to be performed after measuring the weight of the object to be weighed after the stabilization time of the weight sensor 7 has elapsed, thereby determining the discharge combination. Operation cycle time). This one weighing cycle time Tw includes a margin time or a waiting time until the object to be weighed starts to be discharged from the storage chamber selected for the discharge combination after the discharge combination is determined by the combination processing. However, it is preferable to set the operation so that these times become zero for high-speed operation.

  First, as shown in FIG. 6A, in the case of a single shift operation, the above combination processing is performed every Tw time, and the discharge command from the packaging machine 20 input every Tp1 (= Tw) time. In response to the signal, the object to be weighed is discharged from the storage chamber of the discharge combination selected in the combination process. As a result, the object to be weighed is put into the packaging machine once within one weighing cycle time Tw.

  For example, when a discharge command signal is input from the packaging machine 20, the control unit 16 opens the gate of the storage chamber selected for the discharge combination in response to the discharge command signal, and moves from the storage chamber to the collecting chute 9. The object to be weighed is discharged (time t1). When the next discharge command signal is input, the gate of the storage chamber selected for the next discharge combination is opened, and the objects to be weighed are discharged from the storage chamber to the collecting chute 9 (time t3). Thereafter, the same operation is repeated.

  Note that when the single shift operation is performed, the combination processing shown in the flowchart of FIG. 4 may be changed as follows.

  In the case of the single shift operation, when the number of used measurement values n is an even number, x used in step S4 when step S4 is repeated is, for example, n / 2, n / 2-1, n / 2 + 1, n / 2. -2, n / 2 + 2,..., Or n / 2, n / 2 + 1, n / 2-1, n / 2 + 2, n / 2-2,. The processing of may be changed. Further, when the number n of used measurement values is an odd number and x is set to (n + 1) / 2 in step S3, x used in step S4 is, for example, (n + 1) / 2, (n + 1) / 2 The processing in step S10 may be changed so as to change in the order of -1, (n + 1) / 2 + 1, (n + 1) / 2-2, (n + 1) / 2 + 2,. Further, when the number n of used measurement values is an odd number and x is set to (n-1) / 2 in step S3, x used in step S4 is, for example, (n-1) / 2, ( n-1) / 2 + 1, (n-1) / 2-1, (n-1) / 2 + 2, (n-1) / 2-2,... It may be changed.

  Even when a double shift operation or a triple shift operation described later is performed, the divisor x can be changed as described above. However, in the case of the double shift operation, the storage chamber that is selected as the discharge combination in the combination process and the object to be weighed is discharged does not become an effective measurement value in the next combination process. If x is increased, the number of effective measurement values decreases, which is not preferable for improving measurement accuracy. Similarly, in the case of the triple shift operation, the storage chamber selected as the discharge combination in the combination process and to which the object to be weighed is discharged is effectively weighed in the next combination process and further in the next combination process. Since it does not become a value, increasing the divisor x, which is the planned number of selections, decreases the number of effective measurement values, which is not preferable for improving measurement accuracy. In such a case, if the number of weighing units is not further increased to increase the size of the apparatus, the number of effective weighing values may be n or less in step S1 of the repetitive combination process.

  Next, as shown in FIG. 6 (b), an operation in the case where a double shift operation is performed will be described. Here, a collection hopper (not shown) is provided at the discharge port of the collection funnel 10 to temporarily hold and discharge the objects discharged from the storage chamber. In this case, the objects to be weighed discharged from the collecting hopper are put into the packaging machine 20.

  In the double shift operation, the aforementioned combination processing is performed every Tw / 2 hours, and the objects to be weighed are discharged from the storage chamber of the discharge combination selected in the combination processing. The objects to be weighed discharged from the storage chamber are once held by the collecting hopper, and then discharged from the collecting hopper in response to the discharging command signal from the packaging machine 20 input every Tp2 (= Tw / 2) time. Done. As a result, the object to be weighed is put into the packaging machine 20 twice within one weighing cycle time Tw. In this case, the one discharge cycle time Td2 of the combination weighing device is the same as the one packaging cycle time Tp2 of the packaging machine 20, and is ½ of the one weighing cycle time Tw. Here, the discharge combinations sequentially obtained by the combination processing performed every Tw / 2 hours are shown separately as the first discharge combination and the second discharge combination that are obtained alternately. Here, the measured value of the storage room selected as the first discharge combination is not used in the combination process for obtaining the next second discharge combination. Further, the measured value of the storage room selected as the second discharge combination is not used for the combination process for obtaining the next first discharge combination.

  For example, when a discharge command signal is input from the packaging machine 20, the control unit 16 opens the gate of the collecting hopper in response to the discharge command signal and discharges the objects to be weighed to the packaging machine 20 (time t <b> 1). Further, the storage chamber gate selected as the first discharge combination is opened based on the operation timing of the collection hopper gate, and the objects to be weighed are discharged from the storage chamber to the collection chute 9 (time t1). When the next discharge command signal is input, the gate of the collecting hopper is opened in response to the discharge command signal, and the objects to be weighed are discharged to the packaging machine 20 (time t2). Further, the storage chamber gate selected as the second discharge combination is opened based on the operation timing of the collection hopper gate, and the objects to be weighed are discharged from the storage chamber to the collection chute 9 (time t2). Thereafter, the same operation is repeated.

  In the case of FIG. 6B, the objects to be weighed discharged from the storage chamber at time t1 are collected and held in the collecting hopper until time t2, and the collecting hopper gate is opened and packaged at time t2. It is discharged to the machine 20. Similarly, the objects to be weighed discharged from the storage chamber at time t2 are collected and held in the collecting hopper until time t3, and the collecting hopper gate is opened and discharged to the packaging machine 20 at time t3. .

  In the case of FIG. 6B, the gate opening / closing timing of the collecting hopper and the gate opening / closing timing of the storage chamber are made the same, but the present invention is not limited to this. For example, the control unit 16 can control the opening / closing timing of the gates of the storage hopper based on the opening / closing timing of the gates of the collecting hopper, so that the opening / closing timings of these gates can be varied.

  By performing the double shift operation as described above, discharge to the packaging machine 20 is performed every Tw / 2 hours, enabling high-speed discharge at twice the speed of the single shift operation, and packaging that operates at high speed. It can correspond to the machine 20.

  In the above-described double shift operation, the weighing object is discharged from the storage chamber of the combination process and the discharge combination described above every Tw / 2 hours. On the other hand, in the triple shift operation, the above-described combination process and discharge of the object to be weighed from the storage chamber of the discharge combination are performed every Tw / 3 hours. The objects to be weighed discharged from the storage chamber are once held by the collecting hopper, and then discharged from the collecting hopper in response to a discharge command signal from the packaging machine 20 input every Tw / 3 hours. . As a result, the objects to be weighed are loaded into the packaging machine 20 three times within one weighing cycle time Tw, enabling high-speed discharge at a speed three times that of the single shift operation, and the packaging machine 20 operating at a higher speed. It can correspond to.

  In order to correspond to the packaging machine 20 operated at high speed as described above, a double shift operation or a triple operation is performed, and a collective hopper is provided at the discharge port of the collective funnel 10 as described above, so that the objects to be weighed are one lump. It is desirable to be discharged. Further, even when a single shift operation is performed, a collective hopper may be provided.

  In the present embodiment, each weighing unit has a weighing hopper 6 having two weighing chambers 6a and 6b and two memory chambers 8a and 8b in order to configure a storage chamber that is a target of combination processing. Although the memory hopper 8 is provided, it is not limited to such a configuration. For example, the weighing hopper 6 and the memory hopper 8 may each have only one storage chamber. In this case, the supply hopper 5 may be configured to discharge the object to be weighed to the weighing hopper 6 in one chamber, and the weighing hopper 6 in one chamber is selectively transferred to the memory hopper 8 and the collecting chute 9 in one chamber. Any structure that can discharge the object to be weighed is acceptable. Further, only the weighing hopper 6 having the two weighing chambers 6a and 6b and the memory hopper 8 may be omitted in order to configure the storage chamber of each weighing unit. In this case, the weighing chambers 6 a and 6 b of the weighing hopper 6 may be configured so that the objects to be weighed can be discharged to the collecting chute 9. Alternatively, the memory hopper 8 may be omitted and the weighing hopper 6 may have only one storage chamber. In this case, the supply hopper 5 may be configured to discharge the objects to be weighed to the weighing hopper 6 in one chamber, and the weighing hopper 6 in one chamber may be configured to be able to discharge the objects to be collected to the collecting chute 9. . In addition, you may change variously the structure of the storage chamber used as the object of a combination process.

  The combination weighing device according to the present invention is useful for a combination weighing device having a large number of storage chambers to be subjected to combination processing.

It is a schematic diagram which shows the structure of the combination weighing | measuring apparatus of embodiment of this invention. (A) is the schematic diagram which looked at the supply hopper, the weighing hopper, and the memory hopper of the combination weighing device of the embodiment of the present invention from the outside front, and (b) is the side view of the supply hopper, the weighing hopper, and the memory hopper. It is the schematic diagram seen from. It is a block diagram which shows the outline of the control system of the combination weighing | measuring apparatus of embodiment of this invention. It is a flowchart which shows the combination process in embodiment of this invention. (A) is a figure which shows an example of the measured value of the to-be-measured object currently hold | maintained in each measurement chamber and memory room of 12 measurement units in this Embodiment, (b) is (a) It is a figure which shows an example of the measurement value table created based on the measurement value shown by. FIG. 6A is a timing chart when the combination weighing device according to the present embodiment is configured to perform a single shift operation, and FIG. 6B is a diagram illustrating a double shift operation of the combination weighing device according to the present embodiment. It is a timing chart at the time of comprising.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feeding device 2 Level sensor 3 Dispersing feeder 4 Straight advance feeder 5 Feeding hopper 6 Weighing hopper 6a, 6b Measuring hopper storage chamber (measuring chamber)
7 Weight sensor 8 Memory hopper 8a, 8b Memory hopper storage room (memory room)
9 Collective chute 10 Collective funnel 11 Control unit 12 Vibration control circuit 13 A / D conversion circuit 14 Gate drive circuit 15 I / O circuit 16 Control unit 17 Operation setting indicator 20 Packaging machine

Claims (3)

A plurality of storage chambers for holding and discharging the objects to be weighed respectively;
By performing a combination calculation using the weight values of the weights of the objects to be weighed held in the respective storage chambers, the sum of the weight values of the weights of the objects to be weighed is within the allowable range with respect to the target weight value. And a combination calculation means for obtaining one combination of the storage chambers having an absolute value of the difference between the target weight value and the minimum, and
Control means for discharging the objects to be weighed from the storage chamber of the combination obtained by the combination calculation means,
The combination calculation means includes:
The maximum number n of measurement values used in the combination calculation is determined in advance, and a value obtained by dividing the target weight value by a divisor consisting of an arbitrary integer value is a reference candidate value, and the number of measurement values equal to or greater than the reference candidate value M or more {m is n / 2 when n is an even number and (n-1) / 2 or (n + 1) / 2 when n is an odd number} and is less than the reference candidate value The reference candidate value corresponding to the divisor that minimizes the absolute value of the difference from the n / 2 value among the divisors determined so that the number of measured values of (n−m) or more exists is obtained. And select m number of measurement values by giving priority to a value that is equal to or greater than the reference value and has a small absolute value with respect to the reference value, and less than the reference value that is less than the reference value. Weighing that selects (n−m) weighing values with priority given to the one with the smallest absolute value It performs selection processing, configured combination weighing apparatus to perform the combination calculation using the total of n weighing value selected by the metric selection process. The combination calculation means sets the divisor used in the measurement value selection process to P or more (P is a predetermined integer value of 2 or more) and Q or less {Q is n / 2 when n is an even number. , When n is an odd number, an arbitrary integer value within the range of (n−1) / 2 or (n + 1) / 2} is used, and the combination process including the measurement value selection process and the combination calculation is repeatedly performed. When the combination process is repeatedly performed, in the continuous combination of r times (r is a plurality), the measurement value selection process of the combination process performed later is a combination obtained by the previous combination process. It is configured to perform using a measured value of the weight of an object to be weighed supplied to the storage chamber not belonging to,
2. The combination weighing device according to claim 1, wherein the control unit is configured to discharge an object to be weighed from the storage chamber belonging to the combination every time the combination processing by the combination calculation unit is performed. In the measurement value selection process, when the divisor is the value of P, the combination calculation means has a larger value of the measurement value when there are no m or more measurement values greater than or equal to the reference candidate value. Is selected in preference to n, and when there are not more than (n−m) measurement values less than the reference candidate value, priority is given to n values with a smaller value of the measurement value. The combination weighing device according to claim 2, wherein the combination weighing device is configured to select a measurement value.

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