JPS585368B2 - Weighing method - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a weighing system for a weighing machine that quantitatively weighs fruits and vegetables, confectionery, secondary processed products, fresh foods, etc., which have large variations in unit weight, with high precision and with restrictions on the number of pieces. It is.

In the conventional weighing method, under various conditions such as errors due to head difference, misalignment, damping of the main frame, and variations in unit weight, the measurement accuracy will have an error of one unit weight.

To explain in concrete numerical terms, when weighing 150 g, if the unit weight of the weighed object varies from 20 to 45 g, the main frame will not stop supplying unless the main frame is displaced by 150 g or more.

Now, if the weight is 145g, the supply will not stop, so the next step is
If this one piece weighs 45g, then 190g has entered the hopper, and the supply will stop, but 4
The amount will be 0g.

As described above, in conventional weighing machines that do not stop supplying unless the displacement reaches a set amount, the measurement error range has a variation of at least one unit weight.

Therefore, if the set weight is large, if there are large variations in unit weight, or if the average unit weight is heavy, it has a very inadequate and fatal drawback.

Another conventional method is the correction feeding method, in which the unit weight distribution is divided into several parts in advance for correction feeding, and the result of one-stage weighing is then corrected. There are always errors when weighing and errors in the detection results of single-stage weighing.

In addition, in general, the amount of material that is divided into sections and prepared for correction input is uneven (unit weight), so the amount of preparation for each section is not uniform. The amount is generally an average value, and each category requires approximately the same amount, resulting in an imbalance between demand and supply, and if one of the valley side sections runs out, this mechanism becomes unusable.

In view of the above-mentioned drawbacks of the conventional weighing system, the present invention aims to fundamentally improve and eliminate the drawbacks and provide a combination type automatic weighing machine with revolutionary accuracy.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the structure of the present invention shown in the drawings will be described below.

FIG. 1 shows a schematic diagram of the weighing mechanism of the present invention, where AI, A2, . . . An are weighing machines, B1. B2・
...Bn indicates a weighing hopper of a weighing machine, C indicates a guide chute, D indicates a pool hopper, and E indicates a transfer device linked to a packaging machine, for example, a packet.

Each of the weighing hoppers mentioned above is equipped with an independent supply device (not shown) for the object to be weighed, and the feeding operation of each feeding device begins after the corresponding weighing hopper has finished discharging the object to be weighed. It is possible to use a conventionally known type of feeding device and weighing mechanism that starts when the weighing point is reached and stops after feeding - or a set number of objects to be weighed, or approximately a set weight.

The guide chute C is configured to collect the objects to be weighed discharged from each of the weighing hoppers into a pool hopper D, which is a single section at the bottom.

As will be described later, the pool hopper D is opened at a predetermined time and discharges the collected objects to be weighed into the packet E at the bottom.

Each of the weighing machines A1. A2...An is configured to be able to supply the weight value of the object to be weighed in the corresponding weighing hopper as an input to the electronic calculation circuit of the present invention, as will be described later.

Now, the weighing value signals output from each weighing machine AI, A2...An are sent to al, A2...・・・・・・An.

As shown in the block diagram of FIG. 2, the electronic calculation circuit of the present invention has the above-mentioned measurement value signals a1. a2. . . . First and second adders F capable of selectively adding an.

G, an addition code selection circuit H that selects a combination of addition codes of the first adder F, and the first and second adders F, G.
an addition code storage circuit J for a second adder G that stores a combination code with a value closest to the desired set weight according to the comparison result of the comparator ■; When all combinations of codes are finished, calculation EN
This readout circuit K is used to read out the optimal addition code stored in the addition code storage circuit J using the D signal, and a code discrimination circuit (not shown) is attached to this readout circuit K. The device is configured to open the weighing hopper.

The above-mentioned addition code refers to the combination of code numbers attached to each weighing machine or each weighing hopper.

Now, the code numbers of each weighing machine are Xl, X2.・・・・・・
...If Xn, then the total number of combinations in which one item is extracted from n items is n.

Also, a combination of taking out two out of n items is a combination beam that takes out one beam.

Any one of these combinations is input to the addition code selection circuit H of the electronic calculation circuit.

first and second adders F of the electronic calculation circuit;

The output from G is input to comparator I as the absolute value of the value obtained by subtracting the added value from the respective set value.

That is, the set value is a.

FXIX2O3 calculator G
If the added value of is GX, the input to the comparator ■ is, respectively,
α-1aOF'XI.

β”Iao-GXI.

This comparator ■ is used by the addition code storage circuit J only when α<β.
This is to update the memory code of α〈
In cases other than β, that is, in the case of α≧β, the comparison result does not reach the addition code storage circuit J, and therefore the stored code in the addition code storage circuit J is maintained.

Now, using n weighing machines and combining two weighing machines, the set weight is a.

We will explain the measurement procedure when taking the value closest to .

The code numbers of each weighing machine are Xl, X2...Xn, and the weight values are a1, . a2. ......If it is an, the addition combination code is (X10X2).

(XIx3), (Xt+X4)...(Xn-1+X
n), and calculations are performed by the first adder F in this order.

First, in the case of (XI+X2), the added value of the first adder F is Fx=(at+a2), and this added value is sent to the comparator ■
is entered as a=la0-FXl=la6-(a1+a2).

On the other hand, since the addition value Gx of the second adder G has now started its first calculation, the addition code storage circuit J has not stored the code, so GX=O.

Then, the input to the comparator (2) by the second adder G is β=1ao-GX1=la, -01=Ia, 1.

Here, α and β are compared, and the comparison result is α<β or α
≧β.

Now, if the result of α<β is obtained, the code (X1+
X2) will be stored in the addition code storage circuit J.

Then, the next addition of the first adder F, ie (X1+X3)=
FX=(a1+a3) is a=la0-(a1+a3),
Assuming that the addition value GX=(a1+a2) of the second adder G is β=, a.

A comparison is performed by inputting -(a1+a2)1, and here again a result of α minus β or α≧β is obtained, and thereafter the above operation is automatically repeated until all combinations are completed.

On the other hand, if the comparison result of the comparator I is α≧β, the code stored in the addition code storage circuit J is not updated and the process moves to the next code combination calculation.

In short, α is the absolute value of the error of the added value calculated at that time for each combination code with respect to the set weight value, and β is the absolute value of the minimum error of the added value calculated before that with respect to the set weight value. be.

That is, the addition value GX by the second adder G always indicates the value closest to the set weight value among the values calculated in the previous calculation, and therefore the addition code storage circuit J always indicates the value closest to the set weight value. It memorizes the addition combination codes that were close to each other.

Therefore, the comparator ■ is the sum of the current combination code and
This means that the value closest to the previous set weight value is compared, and the memory is updated only if the comparison result shows that the current value is closer to the set value than the past value. be.

When all the combination calculations in one measurement are completed in this way, a calculation END signal is output, the memory code stored in the addition code memory circuit J is read out, and this memory code is passed through a code discrimination circuit, etc. Only the weighing hopper of the weighing machine corresponding to the code number is opened, and the objects to be weighed are collected in the pool hopper D by the guide chute C and thrown into the bucket) E.

The weight of the object to be weighed is naturally the closest value to the set weight or the same value as the set value.

Note that the weighing hopper from which the object to be weighed has been discharged is supplied with the object to be weighed, and the weighing hopper from which the object has not been discharged remains on standby in preparation for the next weighing calculation.

All combination calculations in the above-mentioned measurements are performed in a very short time by electronic circuits.

Since this is a combination of the weights contained in each weighing hopper, each weighing machine can be set individually for the weight or for the number of pieces.In short, the weight signal of the contents of each weighing hopper can be set. Once you take it out, it will automatically select the item of the set weight and let you take it out.

In addition, when adding a limit condition to the number of pieces in addition to the weight setting, the number of pieces to be weighed at one time in each weighing hopper is set as a constant number, and the addition code is set so that the number of combination codes becomes the desired number. All you have to do is assemble the combinations, and then calculate the set weight in the same manner as described above.

As described above, since this is a combination weighing system, the number of heads for each weighing machine must be determined based on the allowable error in grams for the set weight.

The greater the number of heads, the higher the accuracy can be obtained.

As an example of the above-mentioned weighing method, when the following conditions are used: Object to be weighed: Fruits and vegetables limit = 4 to 6 Unit weight range: 20 to 45 g Set weight: 150 g Number of weighing machine heads: 8 Setting the number of pieces: X1X2X3X4X5X6X7X8 22g 20g 35g 22g 45g 31g 2
If we get a result of 5g 30g, all combinations of n=8 2
It reads 4 to 6 codes (X1+X2+X4+X6+X7+X8) out of 255 combinations (°-1=2e-1), resulting in a total weight of 6 pieces of 150 g.

In addition, as another example, there is no limit on the number of the above conditions,
When the set weight is 1 kg, a certain arbitrary amount is set as a rough measurement setting, and the remaining weight is combined with the weight selection method.As explained above, the weighing method of this invention does not directly affect the measurement accuracy due to variations in unit weight, and is very effective. In addition to being able to perform highly accurate weighing, disturbances in supply or alignment do not directly lead to weighing or errors, and even if the set weight becomes large, high precision can be maintained.

In addition, since it is a combination of the actual weighing values of each weighing machine, errors in the settings of each weighing machine do not affect the final error, and the individual unit weight,
It is ideal for assorting or packaging items to a predetermined weight because the weight of individual items, bags, and packets varies and cannot be processed by counting, and in particular, the error curve has an extremely large number of values close to 0, making it ideal. , items that deviate from the optimal combination code are not processed and remain in the next calculation, so the items are not scratched.

Further, there are advantages in that the weighing machine and the packaging machine can be easily linked together, and that the weighing machine can be accurately and quickly automatically fed to the packaging machine.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a metering mechanism in the metering method of the present invention, and FIG. 2 is a block diagram of an electronic calculation circuit. A: Weighing machine, B: Weighing hopper,
C...Chute, D...Pool hopper, E...Packet.

Claims (1)

[Claims] 1. Weigh the weights of the objects to be weighed supplied to the plurality of weighing hoppers, add up each different combination of arbitrary or predetermined numbers of actual measured amounts, and compare each added value with the required predetermined weight. A weighing method characterized in that a combination of predetermined weights or similar weights is obtained, and objects to be weighed corresponding to this combination are collected and discharged to a transfer device linked to a packaging machine or the like.