JP6091898B2 - Combination scale - Google Patents

Description

  The present invention relates to a semi-automatic combination weigher that manually supplies objects to be weighed, and more particularly to a combination weigher that mixes and weighs a plurality of different types of objects to be weighed.

  2. Description of the Related Art Conventionally, there is a combination weigher that performs so-called mix weighing in which a plurality of different types of objects to be weighed are mixed and weighed so that the total weight of the mixed objects falls within a predetermined weight range (see, for example, Patent Document 1).

  In addition, when performing mix weighing, there is also a monetary combination weigher that measures the total amount of the mixed objects to be measured or the amount close to the target amount, not the total weight of the mixed objects to be weighed. (For example, refer to Patent Document 2).

Japanese Patent Laid-Open No. 7-198466 Japanese Utility Model Publication No. 1-102731

  In FIG. 1, FIG. 2, etc. of the above-mentioned patent document 1, an automatic combination weigher that automatically supplies and discharges an object to be weighed is disclosed as a combination weigher that performs mix weighing.

  However, with an automatic combination weigher, for example, in the case of an object to be weighed having a relatively large single unit weight and an irregular shape, it is difficult to automatically convey the object. Not.

  The monetary combination weigher described in Patent Document 2 is a manual combination weigher that manually supplies and discharges an object to be weighed. Therefore, it is difficult to automatically move an object to be weighed as described above. Although it is suitable for mix weighing, there is a drawback that workability is very poor due to manual operation.

  3 and 4 of the above-mentioned Patent Document 1 are semi-automatic, which can also handle mixed weighing of objects to be weighed that are difficult to be automatically conveyed, and manually put the objects to be weighed into the combination weigher and discharge automatically. A formula combination weigher is also disclosed.

  However, in the semi-automatic combination weigher disclosed in Patent Document 1, an operator manually loads an object to be weighed into each of a plurality of weighing hoppers from each loading port, and the weighing hopper selected by the combination calculation is used. The object to be weighed is discharged onto the belt conveyor and transported. However, the belt conveyor transports the object to be weighed in the direction in which the weighing hoppers are lined up. The weighing hopper is located at a very high position. For this reason, there is a case where the impact when the object to be weighed falls from the weighing hopper to the belt conveyor is large, and the object to be weighed which is easily broken or damaged may be damaged to reduce the value of the product or not be sold as a product.

  The present invention has been made in view of the above points, and provides a semi-automatic combination weigher that can perform mix weighing without damage even if the object is fragile or easily damaged. For the purpose.

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

(1) The combination weigher of the present invention is a combination weigher in which a plurality of types of objects to be weighed are mixed and weighed,
A plurality of weighing conveyors that are grouped according to the type of the objects to be weighed, and corresponding types of objects to be weighed are supplied, and the objects to be weighed selected by the combination operation are conveyed;
A plurality of weight sensors for respectively weighing the objects to be weighed supplied to each weighing conveyor;
A transport conveyor for transporting objects to be weighed discharged from the weighing conveyor;
A combination calculation unit for performing the combination calculation based on the output of the weight sensor;
A control unit for controlling the driving of the weighing conveyor and the transfer conveyor based on the combination calculation result of the combination calculation unit;
The combination calculation unit includes a weight combination of the objects to be weighed for each group out of the plurality of weighing conveyors to which the objects to be weighed are supplied, and an allowable weight range for each group, and each The total combination of weights of the group's weighing objects is within the total allowable weight range of multiple types of weighing objects , and the total weight of the weighing objects of each group and the unit price of the weighing object. Select a combination of weighing conveyors whose amount is based on the total target amount of multiple types of objects to be weighed ,
The control unit drives the weighing conveyor selected by the combination calculation unit to discharge the objects to be weighed to the transport conveyor, and drives the transport conveyor to transport the discharged objects to be weighed. .

  According to the combination weigher of the present invention, since the objects to be weighed are not discharged from the weighing hopper to the belt conveyor as in the prior art, but are discharged from the weighing conveyor to the transport conveyor, the level difference between the conveyors is reduced, and the weighing conveyor It is possible to reduce the impact when the object to be weighed transferred from the machine to the conveyor is dropped. In addition, among the plurality of weighing conveyors to which the objects to be weighed are supplied, the weight combinations of the objects to be weighed for each group are within the allowable weight range, and the total of these is the total of the plural kinds of objects to be weighed. Since the weighing objects are discharged by selecting a combination of weighing conveyors within the allowable weight range, even if the weighing objects are fragile or easily damaged, the mixed weighing can be performed without damage.

According to the present invention , in the combination calculation, there are combinations of the weights of the objects to be weighed for each group in each allowable weight range, and there are a plurality of combinations of weighing conveyors in which the total of them is within the total allowable weight range. Can select a combination of weighing conveyors whose amount based on the total and the unit price of the objects to be weighed is close to the overall target amount.

  Even when the combination of the weights of the objects to be weighed for each group falls within the allowable weight range, variation may occur depending on the lower limit side or the upper limit side of the allowable weight range for each group. At this time, if there is a large difference in the unit price of the objects to be weighed for each group, even if the weight is within the allowable weight range as a whole, the total amount of the mixed objects to be discharged from the selected weighing conveyor, that is, However, the value of the product obtained by packing the entire mixed object to be weighed greatly varies. According to this embodiment, since the combination of the weighing conveyors close to the overall target amount is selected, the value of the product is reduced. It is possible to provide consumers with fair products by suppressing variations.

( 2 ) In still another embodiment of the combination weigher of the present invention, the combination calculation unit generates all the combination patterns of the plurality of weighing conveyors, and selects the combination of the weighing conveyors for each combination pattern. Perform the operation.

  For the generation of all combination patterns of a plurality of weighing conveyors, it is preferable to use a Gray code that changes only one bit at a time when changing from one value to an adjacent value.

  According to this embodiment, since the combination calculation is performed for all the combination patterns, for example, when the combination calculation is performed in order for each of the plurality of groups, the measurement of the previous group is performed by the combination calculation of the previous group. The weight of the object is selected and the weight of the selected actual weight is adjusted so that the allowable weight range of the later group is adjusted to satisfy the allowable weight range of the entire group. It is possible to prevent wrinkles from coming to the group, and to perform mix measurement with no bias between the groups, thereby improving the yield.

( 3 ) In another embodiment of the combination weigher of the present invention, the control unit is configured so that the objects to be weighed are discharged from the weighing conveyor to the transport conveyor at the same timing or different timing for each group. The driving timing or conveying speed of the weighing conveyor is controlled.

  According to this embodiment, it is possible to adjust the discharge timing from the weighing conveyor to the transport conveyor for each group of objects to be weighed, i.e., the types of objects to be weighed. It becomes possible to adjust the timing for discharging the objects to be weighed to the packaging machine for each type. Thus, for example, by discharging one kind of objects to be weighed out of two kinds of objects to be measured and then discharging the other kind of objects to be weighed, the packaging machine is in a state of being laminated in two layers. Two types of objects to be weighed can be packaged.

  According to the present invention, it is possible to perform mix measurement without damaging an object to be weighed that is easily broken or damaged by an impact or the like when dropped.

FIG. 1 is a plan view of a combination weigher according to an embodiment of the present invention. FIG. 2 is a front view of FIG. FIG. 3 is a schematic side view showing the weighing conveyor and the transfer conveyor. FIG. 4 is a block diagram of the combination weigher of FIG. FIG. 5 is a flowchart showing an example of the operation of the combination weigher. FIG. 6 shows a part of the Gray code. FIG. 7 is a flowchart showing another example of the operation of the combination weigher.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a plan view of a combination weigher according to an embodiment of the present invention, and FIG. 2 is a front view thereof.

The combination weigher 1 of this embodiment includes a conveyor 2 composed of a belt conveyor that conveys an object to be measured in the direction of arrow A, and a plurality of examples arranged in two rows along the conveying direction of the conveyor 2, in this example Then, weighing conveyors 3 _{1 to} 3 ₁₂ composed of 12 belt conveyors, an apparatus main body 5 supported on the gantry 4 shown in FIG. 2, and setting of operation control parameters such as a target combination weight and an allowable upper limit value, A touch panel type operation setting display 6 for displaying the operation status is provided.

  The combination scale 1 includes a normal mode in which a single type of combination weighing is performed by an operator operating the operation setting display 6, and a mix weighing mode in which a plurality of types of objects to be weighed are mixed and mixed weighing is performed. Can be selected and set. The operation in the normal mode is basically the same as that of the conventional semi-automatic combination weigher. Here, a case where the mix weighing mode is set will be described.

The transport conveyor 2 transports the objects to be weighed selected by the combination calculation and discharged from the weighing conveyors 3 _{1 to} 3 _{12 in the} direction of arrow A, and discharges them to a subsequent packaging machine (not shown).

  In the combination balance 1 of this embodiment, as an example, two types of objects to be weighed will be mixed and weighed and discharged to a packaging machine, and will be described when applied to a packing machine. The objects to be weighed in the mix are not particularly limited, but weighed objects that are relatively large and indefinite and cannot be automatically supplied to the combination weigher, and are easily fragile or easily damaged. , Suitable for mix measurement of heel foot and nails.

The weighing conveyors 3 _{1 to} 3 ₁₂ are linearly arranged in two rows of 6 units along the conveying direction of the conveying conveyor 2 so as to sandwich the conveying conveyor 2 from both sides. As indicated by the symbol B, it is orthogonal to the transport direction of the transport conveyor 2. The six weighing conveyors 3 _{1 to} 3 ₆ in one row constitute a first group G1 for weighing one of the two types of objects to be weighed, and the six weighing conveyors in the other row. 3 _{7 to} 3 ₁₂ constitute a second group G2 for weighing the other type of objects to be weighed.

Operator, one type of the objects to be weighed, placed on an empty weighing conveyor 3 ₁ to 3 ₆ are stopped in the first group G1, the other types of objects to be weighed, the second group G2 Is placed on the empty weighing conveyors 3 _{7 to} 3 ₁₂ .

As shown in the schematic side view of FIG. 3, the weighing conveyors 3 _{1 to} 3 ₁₂ and the conveying conveyor 2 whose conveying directions are orthogonal to each other have small steps between the conveyors and are discharged from the weighing conveyors 3 _{1 to} 3 _12. The impact when the object to be weighed is transferred onto the conveyor 2 can be reduced.

Each of the weighing conveyors 3 _{1 to} 3 ₁₂ is driven by a driving motor installed below the weighing conveyors 3 _{1 to} 3 _12, and each of the weighing conveyors 3 _{1 to} 3 ₁₂ and the driving motor are installed in the apparatus main body 5 such as a load cell. It is supported by a weight sensor (not shown), and the weight of the objects to be weighed on the weighing conveyors 3 _{1 to} 3 ₁₂ is calculated by a control unit described later.

As shown in FIG. 1, indicator lights 8 ₁ to 8 ₁₂ including signal towers are provided on the sides of the weighing conveyors 3 _{1 to} 3 ₁₂ , respectively. Reference numeral 9 denotes an emergency stop switch.

  FIG. 4 is a block diagram showing a schematic configuration of the combination weigher 1 of this embodiment, and parts corresponding to those in FIGS. 1 to 3 are denoted by the same reference numerals.

  The combination scale 1 includes first and second conveyor drive circuit units 10 and 11, an indicator light drive circuit unit 12, an A / D conversion unit 13, a control unit 14, an I / O circuit unit 15, and the like.

Further, each of the weighing conveyor 3 ₁ to 3 ₁₂ is supported by the weight sensor 16 _{1-16 12} such as a load cell, as described above, the weighing conveyor 3 ₁ to 3 ₁₂ on these weight sensors 16 ₁ to 16 ₁₂ The weight of the object to be weighed is measured, and the measured value (analog weight signal) is converted into a digital signal by the A / D converter 13 and sent to the controller 14.

  The control unit 14 includes, for example, a microcomputer, and includes an arithmetic control unit 17 that includes a CPU and a storage unit 18 that includes a memory such as a RAM and a ROM. The storage unit 18 stores an operation program, operation parameter data, measurement data, and the like.

The control unit 14 performs overall control of the combination weigher 1 by the operation control unit 17 executing the operation program stored in the storage unit 18, and performs combination calculation processing and the like described later. For example, the control unit 14 obtains the measured value measured by the weight sensors 16 _{1 to} 16 ₁₂ to which the weighing conveyors 3 _{1 to} 3 ₁₂ are attached as digital values at any time via the A / D conversion unit 13, If necessary, it is stored in the storage unit 18.

Further, the control unit 14 controls the driving of each of the weighing conveyors 3 _{1 to} 3 ₁₂ via the first conveyor driving circuit unit 10 and controls the driving of the conveying conveyor 2 via the second conveyor driving circuit unit 11. Further, a discharge command signal is input from the subsequent packaging machine via the I / O circuit unit 15 and a discharge completion signal is output to the packaging machine. In addition, a signal is input from the operation setting display 6 and a signal such as data to be displayed on the operation setting display 6 is output.

  In this embodiment, two types of objects to be weighed corresponding to the first and second groups G1 and G2 are mixed, and in this case, the total target combined weight obtained by mixing both groups G1 and G2 is used. The operation setting display 6 is operated in one of a weight priority mode for selecting a close optimal combination and a price priority mode for selecting an optimal combination close to the target amount as a whole by mixing both groups G1 and G2. Can be selected.

  First, in the weight priority mode, the operator operates the operation setting display 6, and for example, a target combined weight that is a target value of a total weight (combined weight) obtained by combining the weights of the objects to be weighed in the first group G1. In addition to setting the allowable upper limit value, the target combination weight and the allowable upper limit value of the second group G2 objects to be weighed are set, and further, the target combination weight of the entire object to be weighed by mixing two kinds of objects to be weighed. And set the allowable upper limit.

  For example, if 500 g is set as the target combination weight of the objects to be weighed in the first group G1 and 550 g is set as the allowable upper limit value, the allowable weight range of the objects to be weighed in the first group G1 is 500 g to 550 g.

  On the other hand, in the amount priority mode, the operator operates the operation setting display 6 to set, for example, the unit price per g of the objects to be weighed in the first group G1, the target amount and the upper limit amount, and the second group. The unit price per g of the object to be weighed in G2, the target amount, and the upper limit amount are set. In this example, the target amount for the entire object to be weighed, which is a mixture of two types of objects to be weighed, is the sum of the target amounts of the groups G1 and G2, and the upper limit amount for the entire object to be weighed is the group G1. , G2 is the sum of the target amounts.

  In this amount priority mode, the control unit 14 calculates a target combination weight, an allowable upper limit value, and the like based on the amount set by the operation setting display 6.

  For example, if the unit price per g of the weighing object of the first group G1 is set to 5 yen, the target amount is 2500 yen, and the upper limit amount is 2750 yen, the target combination weight of the weighing object of the first group G1 is 500 g (= 2500 ÷ 5), and the allowable upper limit value is 550 g (= 2750 ÷ 5).

  The above setting is only an example. For example, in the weight priority mode, setting of the target combination weight and the allowable upper limit value of one group is omitted, or in the amount priority mode, the target for the entire object to be weighed is set. An amount and an upper limit amount may be set.

  Further, in this embodiment, when two types of objects to be weighed corresponding to the groups G1 and G2 are packed in the latter packaging machine of the combination weigher 1, they are stacked in two layers and packed, The case of packing at random can be selected and set, and the operator can select which packing to select by operating the operation setting display 6. Here, first, a case where two types of objects to be weighed are packed in a random manner will be described, and a case where two layers are stacked and packed will be described later.

When performing the mixed weighing of two types of objects to be weighed, the operator can place one type of objects to be weighed on the weighing conveyors 3 _{1 to} 3 ₆ of the first group G1 in a stopped state. For example, one piece is placed on an empty weighing conveyor where no one is placed, and the other type of objects to be weighed are weighing conveyors 3 _{7 to} 3 ₁₂ of the second group G2, and are stopped. For example, one piece is placed on an empty weighing conveyor on which an object to be weighed is not placed.

The control unit 14 acquires the measurement values of the weight sensors 16 _{1 to} 16 ₁₂ from the A / D conversion unit 13 at regular time intervals, and performs combination calculation processing based on the measurement values of the weight sensors 16 _{1 to} 16 _12. .

In the combination calculation processing of this embodiment, for each combination pattern of all the combination patterns of the plurality of weighing conveyors 3 _{1 to} 3 ₁₂ , whether or not the weights of the objects to be weighed in the groups G1 and G2 are in each allowable weight range. Or determine whether the total weight of the objects to be weighed in both groups G1 and G2 is within the entire allowable weight range, and if it is not within the allowable weight range, the same determination is sequentially performed for the next combination pattern, When the weight is within the allowable weight range, the combination pattern closest to the entire target combination weight is selected as the optimum combination.

  Then, the objects to be weighed on the weighing conveyors selected for the optimum combination are conveyed by the weighing conveyors and discharged onto the conveying conveyor 2, and are conveyed by the conveying conveyor 2 and discharged to the packaging machine.

  FIG. 5 is a flowchart for explaining the operation of the combination weigher of this embodiment, and shows processing in the above-described weight priority mode.

In this embodiment, as described above, in order to perform arithmetic processing on each combination pattern of all the combination patterns of the _twelve weighing conveyors 3 _{1 to} 3 ₁₂ , the control unit 14 controls the twelve weighing conveyors 3 ₁ to 3. Each combination pattern is generated by generating a 12-bit gray code corresponding to 3 ₁₂ and incrementing the gray code.

  For example, as shown in part of FIG. 6, the Gray code is a code that changes only one bit at a time when changing from a certain value to an adjacent value. In a general binary number, the number of bits that change when moving to an adjacent value is one or more. For example, when changing from “3” to “4”, a 3-bit change occurs from “011” to “100” in binary. In the case of performing a combination calculation, by stepping with a Gray code, the number of additions and subtractions is reduced, so that there is an advantage that the combination calculation speed is increased.

  As shown in FIG. 5, first, a combination pattern is initialized (step S101), and a combination operation is performed with the generated combination pattern (step S102). That is, the combination weight which is the total weight of the objects to be weighed placed on the weighing conveyor of the first group G1 of the combination pattern is the allowable weight range based on the target combination weight of the first group G1 and the allowable upper limit value. (Step S103), when it is not within the allowable weight range, the process proceeds to step S109, and when it is within the allowable weight range, the process proceeds to step S104.

  In step S104, the combination weight which is the total weight of the objects to be weighed placed on the weighing conveyor of the second group G2 of the combination pattern is the allowable weight range based on the target combination weight of the second group G2 and the allowable upper limit value. If it is not within the allowable weight range, the process proceeds to step S109. If it is within the allowable weight range, the process proceeds to step S105.

  In step S105, the total weight of the combined weight of the first group G1 in step S103 and the combined weight of the second group in step S104 is the target combination for the entire object to be weighed that is a mixture of two kinds of objects to be weighed. It is determined whether or not it is within the allowable weight range based on the weight and the allowable upper limit value (step S105). If it is not within the allowable weight range, the process proceeds to step S109, and if within the allowable weight range, the process proceeds to step S106.

  In step S106, the combination pattern so far satisfies the steps S103, S104, and S105, and is the optimum (best) total weight combination pattern that is closest to the target combination weight for the entire mixed objects to be weighed ( It is determined whether or not the (best) combination pattern is already stored in the storage unit 18, and if it is not stored, the combination pattern and its total weight are stored as the optimal combination pattern and the optimal total weight (step S108). If already stored, the process proceeds to step S107.

  In step S107, it is determined whether or not the total weight of the combination pattern is closer to the target combination weight for the whole than the already stored optimum total weight. If not, the process proceeds to step S109. The process moves to S108, the combination pattern and the total weight thereof are stored as the optimum combination pattern and the optimum total weight, and the process proceeds to Step S109.

  In step S109, the gray code is stepped to generate the next combination pattern, and it is determined whether or not the combination pattern has already been subjected to the combination operation (step S110), and the combination operation has already been performed. If not, the process ends. Otherwise, the process returns to step S102, and the same processing as described above is performed for the combination pattern.

  When processing for all the combination patterns is completed, the weighing conveyors of the first and second groups G1 and G2 are simultaneously driven in accordance with the optimum combination pattern stored in the storage unit 18, and the weighing object corresponding to the optimum combination pattern is obtained. The product is discharged onto the conveyor 2, and the conveyor 2 is further driven to the packaging machine for discharge.

In addition, in all combinations, when there is no combination that falls within the allowable weight range, the operation setting display 4 and the indicator lights 8 ₁ to 8 ₁₂ are instructed to the weighing conveyor on which the objects to be weighed are to be transferred, and the operator Replace the objects to be weighed on the weighing conveyor.

According to the combination weigher of this embodiment, the objects to be weighed are not discharged from the weighing hopper to the belt conveyor as in the prior art, but are discharged from the weighing conveyors 3 _{1 to} 3 ₁₂ to the transport conveyor 2. The head is small and damage to the weighing object during transportation is reduced.

Further, for each combination pattern of all the combination patterns of the ₁₂ weighing conveyors 3 _{1 to} 3 ₁₂ , whether or not the weights of the objects to be weighed in the groups G1 and G2 are within the allowable weight ranges, It is determined whether or not the total weight of the G2 objects to be weighed is within the entire allowable weight range, and when it is within the allowable weight range, the combination pattern closest to the entire target combination weight is selected as the optimal combination. The weight of the object to be weighed in the previous group is selected by the combination operation in the previous group, as in the case of performing the combination operation in order for each of the plurality of groups, and the weight of the actual object to be weighed is selected. To prevent the rear group from wrinkling, such that the allowable weight range of the rear group is adjusted to satisfy the allowable weight range of the entire group. It is possible to perform the unpolarized mix weighing between groups, the yield is improved.

In the control of the weighing conveyors 3 _{1 to} 3 ₆ and 3 _{7 to} 3 ₁₂ , the conveying conveyors 2 are operated by simultaneously operating the weighing conveyors 3 _{1 to} 3 ₆ and 3 _{7 to} 3 ₁₂ of the first and second groups G 1 and G 2. The two kinds of objects to be weighed are discharged at the top and mixed randomly. For example, the weighing conveyors 3 _{1 to} 3 ₆ of the first group G1 are driven first to measure the objects of the first group G1. Is then discharged onto the transport conveyor 2, and then the weighing conveyors 3 _{7 to} 3 ₁₂ of the second group G 2 are driven to discharge the objects to be weighed in the second group G 2 onto the transport conveyor 2. First, the first group G1 object to be weighed is put into the packaging machine provided in the container, and then the second group G2 object to be weighed is put thereon, and two kinds of objects to be weighed are stacked in two layers and packed. You may make it do. Thus, by mixing different types of objects to be weighed in layers, it can be packed in a good-looking manner. Further, instead of shifting the driving timing of the weighing conveyors 3 _{1 to} 3 ₁₂ between the groups G1 and G2, the conveyance speed of the weighing conveyors 3 _{1 to} 3 ₁₂ may be changed. For example, even if the weighing conveyors of the first and second groups G1 and G2 are simultaneously driven, the weighing conveyors 3 _{1 to} 3 ₆ of the first group G1 are driven at a higher speed than the weighing conveyors 3 _{7 to} 3 ₁₂ of the second group G2. By doing so, the objects to be weighed in the first group G1 can be discharged to the transport conveyor 2 earlier than the objects to be weighed in the second group G2 and stacked in two layers.

  The combination calculation process of FIG. 5 described above is the weight priority mode, but the process when the amount priority mode is selected will be described based on the flowchart of FIG.

  First, a combination pattern is initialized (step S201), and a combination calculation is performed with the generated combination pattern (step S202). That is, the combination weight which is the total weight of the objects to be weighed placed on the weighing conveyor of the first group G1 of the combination pattern is the allowable weight range based on the target combination weight of the first group G1 and the allowable upper limit value. Is determined (step S203).

  Here, the target combination weight and the allowable upper limit value of the first group G1 are based on the unit price, the target amount, and the upper limit amount of the objects to be weighed of the first group G1 set by the operation setting display 6 as described above. Calculated by the control unit 14.

  If it is determined in step S203 that it is not within the allowable weight range, the process proceeds to step S210. If it is within the allowable weight range, the process proceeds to step S204.

  In step S204, the combination weight which is the total weight of the objects to be weighed placed on the weighing conveyor of the second group G2 of the combination pattern is an allowable weight range based on the target combination weight of the second group G2 and the allowable upper limit value. It is determined whether or not.

  The target combination weight and the allowable upper limit value of the second group G2 are based on the unit price, the target amount, and the upper limit amount of the objects to be weighed of the second group G2 set by the operation setting display 6 as in the first group G1. Calculated by the control unit 14.

  If it is determined in step S204 that it is not within the allowable weight range, the process proceeds to step S210. If it is within the allowable weight range, the process proceeds to step S205.

  In step S205, the total weight of the combined weight of the first group G1 in step S203 and the combined weight of the second group in step S204 is the target combination for the entire object to be weighed by mixing two types of objects to be weighed. It is determined whether or not the weight is within the allowable weight range based on the weight and the allowable upper limit value.

  The target combination weight and the allowable upper limit value for the entire mixed objects to be weighed are based on the unit price, the target amount and the upper limit amount of the objects to be weighed in the first and second groups G1 and G2 set by the operation setting display 6. Calculated by the control unit 14.

  If it is determined in step S205 that it is not within the allowable weight range, the process proceeds to step S210. If it is within the allowable weight range, the process proceeds to step S206.

  In step S206, the amounts of the objects to be weighed in the groups G1 and G2 are respectively calculated by multiplying the unit price of the objects to be weighed by the combination weight of the objects to be weighed, and the total amount is calculated (step S206). S206), the process proceeds to step S207.

  In step S207, the above-described combination patterns satisfy the above-described steps S203, S204, and S205, and the total amount calculated in step S206 is the optimum (best) total amount closest to the target amount for the entire object to be weighed. It is determined whether or not the optimal (best) combination pattern that is a combination pattern is already stored in the storage unit 18, and when it is not stored, the combination pattern and its total amount are used as the optimal combination pattern and the optimal total amount. Store (step S209), and if already stored, proceed to step S208.

  In step S208, it is determined whether or not the total amount of the combination pattern is closer to the target amount for the whole than the already stored optimum total amount. If not, the process proceeds to step S210. Then, the combination pattern and the total amount are stored as the optimum combination pattern and the optimum total amount, and the process proceeds to step S210.

  In step S210, the gray code is stepped to generate the next combination pattern, and it is determined whether or not the combination pattern has already been subjected to the combination operation (step S211), and the combination operation has already been performed. If not, the process ends. Otherwise, the process returns to step S202, and the same processing as described above is performed for the combination pattern.

  When processing for all the combination patterns is completed, the weighing conveyors of the first and second groups G1 and G2 are simultaneously driven in accordance with the optimum combination pattern stored in the storage unit 18, and the weighing object corresponding to the optimum combination pattern is obtained. The product is discharged onto the conveyor 2, and the conveyor 2 is further driven to the packaging machine for discharge.

  Even when the combination of the weights of the objects to be weighed for each of the groups G1 and G2 is within the allowable weight range, the variation may occur depending on the lower limit side or the upper limit side of the allowable weight range for each group G1 and G2. There is. At this time, if there is a large difference in the unit price of the objects to be weighed for each of the groups G1 and G2, even if the weight is within the allowable weight range as a whole, the entire mixed objects to be discharged discharged from the selected weighing conveyor The value of the product that packs the entire mixed object to be weighed greatly varies, but in this amount priority mode, a combination of weighing conveyors close to the overall target combination amount is selected. It is possible to provide consumers with a fair product by suppressing variations in product value.

  In the above-described embodiment, the calculation process is performed for all the combination patterns. However, as another embodiment of the present invention, the calculation process is not performed for all the combination patterns. The combination calculation may be performed in order, and the combination of the weighing conveyors to be selected may be determined in order.

In the above-described embodiment, the weighing conveyors 3 _{1 to} 3 ₆ on one side of the transfer conveyor 2 are assigned to the first group G1, and the weighing conveyors 3 _{7 to} 3 ₁₂ on the other side are assigned to the second group G2. , weighing conveyor 3 ₁ to 3 ₃ on the upstream side of the conveying direction of the conveyor 2, a 3 _{7-3 9} to the first group G1, so as to assign the weighing conveyor 3 _{4-3 6,} 3 _{10-3 12} downstream It may be.

  Furthermore, the types of objects to be weighed are not limited to two, but may be three or more, and the number of weighing conveyors is arbitrary.

Further, the weighing conveyors 3 _{1 to} 3 ₁₂ and the transfer conveyor 2 are not limited to belt conveyors, and may be other conveyors such as a chain conveyor and a roller conveyor.

1 Combination Weigher 2 Conveyor 3 _{1 to} 3 ₁₂ Weighing Conveyor 14 Controller 16 _{1 to} 16 ₁₂ Weight Sensor

Claims (3)

A combination scale for mixing and weighing a plurality of types of objects to be weighed,
A plurality of weighing conveyors that are grouped according to the type of the objects to be weighed, and corresponding types of objects to be weighed are supplied, and the objects to be weighed selected by the combination operation are conveyed;
A plurality of weight sensors for respectively weighing the objects to be weighed supplied to each weighing conveyor;
A transport conveyor for transporting objects to be weighed discharged from the weighing conveyor;
A combination calculation unit for performing the combination calculation based on the output of the weight sensor;
A control unit for controlling the driving of the weighing conveyor and the transfer conveyor based on the combination calculation result of the combination calculation unit;
The combination calculation unit includes a weight combination of the objects to be weighed for each group out of the plurality of weighing conveyors to which the objects to be weighed are supplied, and an allowable weight range for each group, and each The total combination of weights of the group's weighing objects is within the total allowable weight range of multiple types of weighing objects , and the total weight of the weighing objects of each group and the unit price of the weighing object. Select a combination of weighing conveyors whose amount is based on the total target amount of multiple types of objects to be weighed ,
The control unit drives the weighing conveyor selected by the combination calculation unit to discharge the objects to be weighed to the transport conveyor, and drives the transport conveyor to transport the discharged objects to be weighed.
A combination weigher characterized by that. The combination calculation unit generates all combination patterns of the plurality of weighing conveyors, and performs an operation for selecting the combination of the weighing conveyors for each combination pattern.
The combination weigher according to claim 1. The control unit controls the driving timing or the conveying speed of the weighing conveyor for each group so that the objects to be weighed are discharged from the weighing conveyor to the conveying conveyor at the same timing or different timing for each group.
The combination weigher according to claim 1 or 2 .

Images