JPH0438297B2 - - Google Patents

Description

Detailed Description of the Invention <Field to which the present invention pertains> The present invention is a method for reducing the weight of articles (hereinafter referred to as lumps) that vary in individual weight, such as sausages, sweets, fruits, and vegetables, to a substantially constant weight. The present invention relates to a combination selection circuit for a combination weighing machine, which is used when packing a plurality of items into bags.

<Prior Art> (Figs. 4 and 5) Even if an attempt is made to group together a set weight of lumps whose individual weights vary, an error will occur between the set weight and the target weight. For this reason, a combination weighing machine has conventionally been used to always reduce the error from the set weight as much as possible and group the weights together.

That is, in the combination weighing machine, as shown in FIG. 4, objects to be weighed consisting of a plurality of lumps are sequentially supplied to a plurality of weighing hoppers ₁₁ to _1o , and each of the weighing hoppers ₁₁ to _1o
The plurality of lumps contained therein are each weighed by the weighing machines 2 ₁ to 2 _o provided in each weighing machine 2 ₁ .
~2 _o Weighing values are input to the combination selection circuit 3 to calculate the combination weight for each combination, and among all the combination weights obtained by calculation, the difference from the set weight is the smallest, and upper limit value,
Determine the combination that falls within the lower limit value,
The objects to be weighed in the combination hopper of this combination are discharged and collected in a collection chute or the like.

<Problems to be Solved by the Present Invention> In such conventional combinations, there are cases where it is desired to manage not only the combined weight but also the combined number.

At this time, if the standard deviation of the individual weights of the lumps is extremely small, the number of combinations can be easily obtained by dividing the combined weight by the average weight of the lumps.

That is, if the combined weight is managed, the number of pieces is also managed at the same time.

However, when the standard deviation of the individual weights of the lumps is large to some extent, the number obtained by simply dividing the combined weight by the average weight of the lumps may differ from the actual number.

That is, the individual weight distribution of the lumps is a in FIG.
As shown in , the weight is distributed with a standard deviation centered around the average weight W ₀ . The weight distribution of a plurality of these lumps (for example, N-1 pieces, N pieces, N+1 pieces) is as shown in b, c, and d in the figure, respectively (N-1) W ₀ , NW ₀ , (N+1) It is known that the weight is distributed around the weight value of W ₀ with a standard deviation approximately √-1, √, √+1 times the standard deviation of the weight distribution a of a single unit. When the standard deviation of the weight distribution a of a single substance is large or when the number N of combinations of lumps is large, the weight distributions b, c, and d are approximately ±W ₀ /2 with respect to NW ₀ as shown in the same figure. Overlapping parts A and B occur at the point.

Therefore, for example, when the total weight of the combined lumps is W grams in the figure, it is not possible to determine whether the combined number of lumps is N-1 or N.

To explain with a practical example, when packing multiple wieners with an average weight of 10 grams into bags with a target weight of 100 grams, one bag contains
A total of 10 wieners are packed, 5 of which weigh 11 grams and 5 of which weigh 9 grams, and the other bag contains 8 wieners, 4 of which weigh 15 grams each, and 4 of which weigh 10 grams. It happens that the wiener of the book gets stuffed.

That is, even if the products are the same, the difference in the number of products can be seen at first glance. In other words, the problem of product non-uniformity will occur.

<Object of the present invention> The present invention was made to solve the above-mentioned problems, and an object thereof is to provide a combination selection circuit for a combination weighing machine that makes not only the combined weight but also the combined number uniform. It is said that

<Example of the present invention> An embodiment of the present invention will be described below.

1 and 2 show the combination selection circuit of the present invention.

In Figure 1, 10 ₁ to 10 _o is the weighing hopper 1.
Measurement value storage circuits ₁₁ to 11 _o each store measurement value signals from measuring instruments 2 ₁ to 2 _o for measuring the weight of objects to be measured supplied _{to 1} to 1 _o , and a combination control circuit 41 to be described later. This is a group of switches that are sequentially turned on one by one in response to all combination patterns from .

12 is an adder that sequentially adds the metric value of one of the metric value storage circuits 10 ₁ to 10 _o inputted via the switch groups 11 ₁ to 11 _o to the value temporarily stored in the register 13; The result added by the adder 12 is stored via the switch 14, and the adder 12
This is a register that sequentially outputs the stored values. In addition, here, switch 14 is also
It is turned on by an addition signal from a combination control circuit 41, which will be described later.

Reference numeral 15 denotes an upper limit weight setting device for setting and outputting an upper limit weight value of the target weight, and numeral 16 a lower limit weight setting device for setting and outputting a lower limit weight value for the target weight.

17 compares the stored value stored in the register 13 and outputted sequentially with the upper limit weight value from the upper limit weight setter 15, and when the stored value from the register 13 is smaller than the upper limit weight value, the level becomes "H". , on the other hand, is a comparator that outputs an "L" level when it is large.

18 compares the stored value stored in the register 13 and outputted sequentially with the lower limit weight value from the lower limit weight setter 16, and when the stored value from the register 13 is greater than the lower limit weight value, the level is "H"; On the other hand, it is a comparator that outputs "L" level when it is smaller.

Reference numeral 19 denotes an AND circuit that performs the logical product of the outputs from the comparators 17 and 18.

Reference numeral 20 compares each of the weighing values stored in the weighing value storage circuits 10 ₁ to 10 _o with m reference values set in advance as integral multiples of the average weight of a single unit, and determines the deviation weight that minimizes the deviation. Calculate each value,
This is a deviation value calculation circuit that outputs this, and its contents will be described later.

30 ₁ to 30 _o are deviation value storage circuits that respectively store the minimum deviation value from the reference value for each measured value calculated by the deviation value calculation circuit 20.

31 ₁ to 31 _o are switch groups that are sequentially turned on one by one in synchronization with the switch groups 11 ₁ to 11 _o in response to all combination patterns from a combination control circuit 41 to be described later.

32 is an adder that sequentially adds the deviation value of one of the deviation value storage circuits 30 ₁ to 30 _o inputted via the switch groups 31 ₁ to 31 _o to the value temporarily stored in the register 33; The result added by the adder 32 is stored via the switch 34, and the result added by the adder 32 is stored via the switch 34.
This is a register that sequentially outputs the stored values. In addition, here switch 34
is turned on in synchronization with the switch 14 by an addition signal from a combination control circuit 41, which will be described later.

35 is an upper limit deviation setting circuit in which an allowable upper limit deviation value of the deviation value added by the adder 32 is set and outputted; 36 is an upper limit deviation setting circuit for setting the allowable upper limit deviation value of the deviation value added by the adder 32; This is a lower limit deviation setting circuit in which a lower limit deviation value is set and outputted.

37 compares the stored value stored in the register 33 and outputted sequentially with the upper limit deviation value from the upper limit deviation setting circuit 35, and becomes "H" level when the stored value from the register 33 is smaller than the upper limit deviation value. , on the other hand, is a comparator that outputs an "L" level when it is large.

38 compares the stored value stored in the register 33 and sequentially outputted with the lower limit deviation value from the lower limit deviation setting circuit 36, and becomes "H" when the stored value from the register 33 is greater than the lower limit deviation value. This is a comparator that outputs "L" level when the level is low.

39 is an AND circuit that takes the AND of the outputs from the comparators 37 and 38; 40 is an AND circuit 19 and 3;
9 and an addition end signal from a combination control circuit 41, which will be described later.

41 is a switch group 11 ₁ to 11 _o , 31 ₁ to 3
The switch groups 11 ₁ to 11 _o , 3 are controlled synchronously to correspond to all combination patterns _of measurement values.
1 ₁ to 31 _o are selected and turned ON one by one, and an addition signal synchronized with this is sent to the switches 14 and 34, and furthermore, switch groups 11 ₁ to 11 _o , 31 ₁ to 31 according to one combination pattern are selected. At the end of the control of _o , the addition end signal of "H" level is sent to the AND circuit 4.
This is a combinational control circuit that sends data to 0.

Reference numeral 42 denotes a combination storage circuit that temporarily stores the combination pattern from the combination control circuit 41 by using the "H" level output from the AND circuit 40, and outputs this combination pattern.

Note that the deviation value calculation circuit 20 is configured as shown in FIG.

In the figure, 21 ₁ to 21 _n are m reference values (for example, 10, 20, 30...10×
This is a reference value setting circuit in which a value corresponding to m) is set.

22 ₁ ~ 22 _n is sequentially one by one in the order of 1 ~ m
The group of switches to be turned on, 23, is the measurement value storage circuit 1
From the measured values from 0 ₁ to 10 _o , switch group 22 ₁
~22 _n Reference value setting circuit 21 ₁
This is a subtracter that subtracts a reference value of ~21 _n and outputs the result of this subtraction. 24 is an absolute value conversion circuit 25 that converts the subtraction result from the subtracter 23 into an absolute value and outputs this absolute value and a code value before conversion;
stores the absolute value from the absolute value conversion circuit 24 via the switch 26 and outputs it to the comparator 27, and also stores the positive and negative sign values of the subtraction result before the absolute value is exchanged, separately from the absolute value. , a minimum deviation value storage circuit that stores the value via the switch 28.

27 compares the new absolute value from the absolute value conversion circuit 24 with the stored value stored in the minimum deviation storage circuit 25, and only when the new absolute value is smaller than the stored value, switches 26 and A comparator that sends an output to 28. After the minimum absolute value is obtained, 29 combines this minimum absolute value with the original positive/negative sign and outputs it as a deviation value from the minimum deviation value storage circuit 25 to the deviation value storage circuit _301. This is a switch for

Note that the deviation value calculation circuit 20 includes calculation circuits 20 ₁ to 20 _o having exactly the same configuration as the circuit configuration described above.
are provided in parallel for each of the measured value storage circuits 10 ₁ to 10 _o , and the deviation values are calculated from the measured values from the measured value storage circuits 10 ₁ to 10 _o by the respective arithmetic circuits 20 ₁ to 20 _o. The deviation storage circuit 30 ₁ ~
30 _o will be stored.

<Operation of the example> Next, the operation of the above embodiment will be explained.

(1) The weight of the objects to be weighed supplied to the weighing hoppers 1 ₁ to 1 _o is weighed by the respective weighing devices 2 ₁ to 2 _o ,
Each of the measured values is stored in the storage circuits 10 ₁ to 10 _o , respectively, and each of the stored measured values is input to each of the calculation circuits 20 ₁ to 20 _o of the deviation value calculation circuit 20.

The measured value storage circuit 10 ₁ (e.g. _{, the value 32) inputted to the arithmetic circuit 20 1 is stored as the} reference value (e.g., 10, 20,
30...10×m) and are sequentially subtracted by the subtractor 23 to obtain the subtraction results (+22, +12, +2, -8, -18
...) are sequentially converted into absolute values (22, 12, 2, 8, 18...) by the absolute value conversion circuit 24 and input to the comparator 27. At this time, the initial value of the subtraction result (value "22") is
is stored in the minimum deviation storage circuit 25 via.

The comparator 27 compares the initial stored value (“22”) stored in the minimum deviation storage circuit 25 with the next input subtraction result (“12”), and calculates the value from the stored value (“22”). Since the new input value ("12") is small, the output from the comparator 27 is sent to switches 26 and 28, and this new input value ("12") is also sent to the switches 26 and 28 via the switch 26. 28
The original code value is separately stored in the minimum deviation value storage circuit 25 via the minimum deviation value storage circuit 25. Subsequently, the next input value (“2”) and the stored value (“12”) are compared, and similarly, the new input value (“2”) and the sign value are stored as the minimum deviation value via switches 26 and 28. It is stored in circuit 25. Furthermore, the next input value ("8") and the stored value ("2") are compared by the comparator 27, but at this time, the new input value ("8") is compared with the stored value ("2"). ) is large, no output is generated from the comparator 27 to the switches 26 and 28, and the stored value remains at the previous value ("2"). Thereafter, in the same manner, the new input value and the stored value of the minimum deviation value storage circuit 25 are compared (m-1) times, and as a result,
The minimum deviation value storage circuit 25 stores the minimum deviation value (“2”) with respect to the m reference values and the original code value. This minimum deviation value (“2”) and the original code value are transmitted via the switch 29,
It is input to the deviation value storage circuit 30 ₁ and stored as a deviation value including positive and negative signs.

The above operations are performed in each of the calculation circuits 20 ₁ to 20 _o of the deviation value calculation circuit 20, and the minimum deviation value obtained based on the respective measurement values stored in the measurement value storage circuits 10 ₁ to 10 _o is determined. , are stored in the deviation value storage circuits 30 ₁ to 30 _o , respectively.

(2) Next, the measured values stored in the measured value storage circuits 10 ₁ to 10 _o and the deviation values stored in the deviation value storage circuits 30 ₁ to 30 _o are processed according to the combination pattern from the combination control circuit 41. The signals are sequentially input to adders 12 and 32 via switch groups 11 ₁ to 11 _o and 31 ₁ to 31 _o , which are turned on in sequence and in synchronization.

In the adder 12, the sequentially inputted measurement values are added to the stored value of the register 13 having an initial value of 0, and the addition result is added to the combination control circuit 41.
Each time a weighing value is input,
Register 13 through switch 14 that is turned ON.
is memorized. Therefore, the metric values selected by the combination pattern are accumulated in the register 13.

The addition results stored in the register 13 are input to comparators 17 and 18, and are compared with the upper limit weight value set in the upper limit weight setting device 15 and the lower limit weight value set in the lower limit weight setting device 16, respectively. .

Therefore, only when the cumulative weight values selected by the combination pattern are between the upper limit weight set in the upper limit weight setter 15 and the lower limit weight set in the lower limit weight setter 16, The outputs of comparators 17 and 18 both go to "H" level, and the output of AND circuit 19 goes to "H" level, and otherwise goes to "L" level.

That is, when the output of the AND circuit 19 is at the "H" level, it can be determined that the sum of the weight values selected by the combination pattern is within the target weight range.

On the other hand, the deviation values sequentially input to the adder 32 are the upper limit deviation value and lower limit deviation value of the upper limit deviation setter 35 and lower limit deviation setter 36 to be compared.
The calculation process is completely the same as the calculation of the measured value except that the value is different from the value explained above.

That is, the deviation values selected by the combination pattern are sequentially stored in the register 3 by the adder 32.
3 is accumulated and stored, and this stored value is added every time it is added.
The upper limit deviation setter 3 is set by the comparators 37 and 38.
5. It is compared with the upper limit deviation value and lower limit deviation value of the lower limit deviation setter 36. Here, the average weight of the unit is
As W ₀ , the above-mentioned deviation value is set in advance to W ₀ /2, and the lower limit deviation value is set to (-W ₀ /2). Then, the stored value accumulated and stored in the register 33 is between the upper limit deviation value and the lower limit deviation value (±W ₀ /
2), the outputs of the comparators 37 and 38 become "H" level, and the output of the AND circuit 39 becomes "H" level.

Also, 1 selected by the combination pattern
If the final accumulation of the set of weight values is outside the target weight range, the output of the AND circuit 19 will be at the "L" level, and therefore the AND circuit 40 will output the "L" level. This "L" level output is sent to a control circuit (not shown), and calculation based on the next combination pattern is started.

Therefore, the final accumulation of one set of weight values selected by the combination pattern is within the target weight range, and the accumulation of the same set of deviation values is always within the upper and lower limit deviation range (0±W _0/2 ), the output of the AND circuit 40 becomes "H" level. The "H" level output from the AND circuit 40 is sent to the combination storage circuit 42, and the combination pattern at this time is stored.

The weighing hopper corresponding to the combination determined in this way is released, and the discharged objects to be weighed are grouped together. After being discharged, the objects to be weighed are supplied to those weighing hoppers again, and the above operation is repeated.

As shown in Figure 3, the weight distribution f of the weighed objects grouped together (for example, N pieces) is limited to NW ₀ because the total deviation is limited within the range of 0 + W/2. Therefore, there is no distribution outside the range of ±W ₀ /2. Also,
The same holds true for (N-1) and (N+1) weight distributions e and g.

Therefore, for example, if the total weight of the objects to be weighed together (ie, the final stored value of the register 13) is W grams, it can be determined that the combined number of objects to be weighed is N.

<Other Embodiments of the Present Invention> In the above embodiments, each deviation is calculated from the measured value of the object to be measured stored in the measured value storage circuit by an arithmetic circuit provided in parallel for each weighing device. Although the values were determined, this may be one arithmetic circuit, and the input and output may be switched using a switch to sequentially determine the deviation values.

In addition, the upper limit deviation value and lower limit deviation value are O±
It is not limited to W ₀ /2 (W ₀ is the average weight of a single item), and the range of this deviation value can be fixed or automatically set within ±W ₀ /2 depending on the object to be weighed. good.

Furthermore, in the above embodiment, when the final accumulation of a set of weighing values selected by a combination pattern is within the target weight range and the accumulation of deviation values of the same set is always within the set range, the combination pattern is determined, and after the objects to be weighed are discharged according to this combination pattern, the objects to be weighed are again supplied to these weighing hoppers. However, this may be determined by performing similar arithmetic processing on all combination patterns and selecting, from among the combination patterns obtained, the combination pattern in which the total weight of the object to be weighed is closest to the target weight.

Further, although the measured value storage circuit 10 was provided in the above embodiment, it is not necessary to provide this in particular, and the calculation method of the deviation value calculation circuit 20 is not limited to the above embodiment. You can find the deviation by repeatedly subtracting the single average weight from the total weight, or you can divide the total weight of the combination by the single average weight, calculate the quotient, and the remainder.Total weight - (quotient + 1) x single unit It is also possible to compare the value obtained by calculating the average weight and the remainder value obtained by division, and use the smaller value as the deviation value.

<Effects of the Present Invention> As is clear from the above description, the combination selection circuit of the present invention compares the measured value from each measuring device with a plurality of reference values set to integral multiples of the average weight of each unit. Then, find the minimum deviation value, calculate the combination of each measurement value, and at the same time accumulate each deviation value,
A combination is selected such that the accumulated deviation is always within a predetermined range and the total of the measured values is within the target weight range.

Therefore, since combinations of objects to be weighed with large weight deviations are prohibited, objects to be weighed with individual weight deviations are combined into one.

For this reason, the number of objects to be weighed is equalized, so individual weight deviations are small.
It is possible to provide a product whose number is uniform, that is, whose quality is controlled.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a block diagram showing a part of FIG. 1,
FIG. 3 is a diagram showing the weight distribution of the combination result according to one embodiment of the present invention. FIG. 4 is a diagram showing a conventional combination weighing device, and FIG. 5 is a diagram showing the weight distribution of the conventional combination result. 1 ₁ ~ 1 _o ... Weighing hopper, 2 ₁ ~ 2 _o ... Measuring instrument, 10 ₁ ~ 10 _o ... Measurement value storage circuit, 11 ₁ ~
11 _o ...switch group, 12... adder, 13...
...Register, 15... Upper limit weight setting device, 16...
Lower limit weight setting device, 17... Comparator, 18... Comparator, 19... AND circuit, 20... Deviation value calculation circuit, 21 ₁ to 21 _n ... Reference value setting circuit, 22 ₁ to
22 _n ...Switch group, 23...Subtractor, 24...
... Absolute value conversion circuit, 25 ... Minimum deviation value storage circuit, 27 ... Comparator, 30 ₁ to 30 _o ... Deviation value storage circuit, 31 ₁ to 31 _o ... Switch group, 32 ...
Adder, 33... Register, 35... Upper limit deviation setting circuit, 36... Lower limit deviation setting circuit, 37... Comparator, 38... Comparator, 39... AND circuit, 4
0...AND circuit, 41...Combination control circuit, 4
2...Combination pattern storage circuit.

Claims (1)

[Scope of Claims] 1. A reference value setting circuit in which a plurality of reference values each having a value that is an integral multiple of the average weight of an object to be weighed; and a measurement value of an object to be weighed supplied to a plurality of weighing hoppers. a deviation calculating circuit that calculates the deviation from a reference value closest to the measured value set in the reference value setting circuit; and storing the deviation for each measured value calculated by the deviation calculating circuit. a deviation storage circuit for determining whether the total weight of any combination of the weight values of the objects to be weighed supplied to the plurality of weighing hoppers is within a predetermined range; a second determination circuit that determines whether the sum of the deviations stored in the deviation storage circuit based on the combination of the measurement values of the first determination circuit and the same combination is always within a predetermined range; The first determination circuit determines whether the combined weight is within a predetermined range from among arbitrary combinations of
A combination selection circuit for a combination weighing machine, characterized in that the second determination circuit selects a combination whose combination deviation always falls within a predetermined range.