JPH0628658U - Automatic calculation device and automatic setting device of loading detection point in combination scale - Google Patents

Abstract

(57) [Summary] [Purpose] To improve weighing accuracy and weighing speed by automatically calculating load detection points and setting them on the combination weigher. A plurality of weight detectors 1 for measuring the weight of articles supplied to a plurality of respective weighing hoppers 2 are provided, and the weight value of an article which is equal to or higher than a loading detection point TD among the weight values of these articles is displayed. In a combination weigher that supplies various articles to the weighing hoppers 2 below the load detection point TD, a combination of the total weighing values that is equal to or close to the target weight TW is selected from the various combinations. The target weight TW is obtained by the value (a × NH + b) of the sum of the number a · NH close to the total number and the correction value b based on the total number HNO of the weighing hoppers 2.
And a load detection point calculation means (step 112) for calculating the load detection point TD and the calculated load detection point T.
Loading detection point setting means (step 122) for setting D to the combination scale.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an automatic calculation device and an automatic setting device for a load detection point in a combination scale for automatically calculating a weight, that is, a load detection point for determining the presence or absence of an item to be weighed in a weighing tank.

[0002]

[Prior art]

 The combination weighing machine to which the automatic load detection point calculation device and automatic setting device described above have, for example, a plurality of weighing hoppers for weighing the weights of the articles, and the weights of the articles supplied to the respective weighing hoppers. Various combinations of the above, and a combination of which the total weight is equal to or close to the predetermined target weight is selected, and the articles of the selected combination are discharged, and the articles of the approximately target weight are combined and weighed. You can do it.

Here, when supplying articles to the weighing hopper, it is necessary to determine whether or not the weighing hopper is empty. However, even if the discharge gate is opened to discharge the articles in the weighing hopper, some of the articles may remain attached to the weighing hopper. Therefore, it is determined whether the articles are attached by determining whether the articles are being fed into the weighing hopper or a small amount of the articles are attached. If so, it is reasonable to supply the goods to the weighing hopper. That is, the above-mentioned load detection point serves as a criterion for determining whether or not the goods are supplied to the weighing hopper.

Therefore, conventionally, an operator determines an appropriate loading detection point in consideration of the amount of articles attached and sets it on the combination scale. Since the load detection point has a great influence on the weighing accuracy and weighing speed (the number of combined weighings per unit time) of the combination weigher, it is required to be rationally determined.

[0005]

[Problems to be solved by the device]

 However, the weight of the articles attached to the weighing hopper is determined based on the type of articles to be weighed and the weight of the articles supplied to each weighing hopper (the weight of the articles supplied to each weighing hopper is determined based on the target weight). However, if the operator decided the loading detection point as in the past, there is a problem that the operator's arbitrary will not be able to always determine an appropriate value. .

If the loading detection point is too large and has an inappropriate value, the weighing hopper may be overscaled (additional load) when an additional article is supplied, and the additional weighing is supplied. As the number of hoppers increases, the number of weighing hoppers participating in the combination weighing decreases, and as a result, the weighing accuracy and weighing speed of the combination weighing decreases. If the load detection point is too small, the weighing hoppers that are supplied with only a small amount of goods will participate in the combination calculation, and it may not be possible to obtain the prescribed weighing accuracy. There is.

An object of the present invention is to provide an automatic calculation device and an automatic setting device for loading detection points in a combination scale that solves the above problems.

[0008]

[Means for Solving the Problems]

 The automatic load detection point calculating device in the combination weigher of the first invention has a plurality of weighing means for weighing the weight of the articles supplied to each of the plurality of weighing tanks. Various combinations of weighing values that are at or above the approximate load detection point are selected, and from among these combinations, a combination of total measurement values that is equal to or close to the specified target weight is selected, and a weighing tank that is below the load detection point described above is selected. In a combination weigher that supplies goods, the above target detection weight is calculated by dividing the above target weight by the sum of the total number of measuring tanks or a number close to it and the correction value based on the total number of measuring tanks. .

The automatic setting device of the load detection point in the combination weigher of the second invention has a plurality of weighing means for weighing the weight of the articles supplied to each of the plurality of weighing tanks, and weighs these articles. Of the values, various weight values of articles that are above the approximate load detection point are combined in various ways, and from among these combinations, a combination of total weight values that are equal to or close to the prescribed target weight is selected, and the load detection values described above are selected. In a combination weigher that supplies articles to weighing tanks below the point, the target weight is divided by the sum of the total number of the weighing tanks or a number close to it and the correction value based on the total number of the weighing tanks, and the above-mentioned load detection point And a loading detection point setting means for setting the calculated loading detection point in the combination weigher.

[0010]

[Action]

 According to the automatic load detection point calculating device in the combination scale of the first invention, the target is determined by the sum of the total number of measurement tanks provided in the combination scale or a number close thereto and the correction value based on the total number of measurement tanks. The load detection point is calculated by dividing the weight. In this way, since the loading detection point is calculated by a predetermined calculation formula, the weight of the articles stored in the weighing tank to which the articles are additionally supplied and the weighing tank to which the articles are not additionally supplied, that is, each weighing The weight of the articles contained in the tank can be kept within a predetermined range. As a result, it is possible to keep the total weight of the articles selected by the combination scale close to the target weight.

According to the load detection point automatic setting device in the combination weigher of the second invention, the load detection point calculation means calculates the load detection point and the load detection point setting means operates in the same manner as in the first invention. The load detection points calculated by the load detection point calculation step are automatically set in the combination scale.

[0012]

【Example】

 In this embodiment, a combination weighing machine is provided with an automatic setting device for loading detection points in the combination weighing machine according to the present invention. FIG. 2 is a block diagram showing the electric circuit of this combination scale. As shown in the figure, the combination weigher has, for example, ten weighing hoppers 2, 2, ... Supported by weight detectors 1, 1, ... Is provided with a discharge gate 3 for discharging articles from these weighing hoppers 2. Corresponding supply hoppers (not shown) are provided above the weighing hoppers 2, respectively. By opening the discharge gates of the corresponding supply hoppers, articles can be supplied to the predetermined weighing hoppers 2. The weighing signal of the weight detector 1 is amplified by an amplifier (not shown) and then supplied to the A / D converter 4 via a multiplexer (not shown), where it is converted into a digital signal, and the CPU 5 (Microcomputer). The CPU 5 sequentially inputs the digital weighing signals of the articles supplied to the weighing hoppers 2, compares them with the loading detection points set in advance and sets whether or not the weighing signals should participate in the combination calculation. To determine.

That is, the weighing signals above the loading detection point (or above the loading detection point) are allowed to participate in the combination calculation, but the weighing signals below the loading detection point (or below the loading detection point) are not allowed to participate in the combination calculation. Then, the articles are additionally supplied to the weighing hopper 2 corresponding to the weight detector 1 which generated the weighing signal. In this way, the CPU 5 variously combines the weighing signals above the load detection point, selects a combination of the total weighing signals equal to or close to the predetermined target weight from the combinations, and selects the combination. The items of the measured signal are discharged from the respective weighing hoppers 2. In this way, articles of approximately the target weight can be weighed.

However, 6 shown in FIG. 2 is an input / output device, and 7, 7 ... And 8, 8 ... Are air cylinders. The air cylinders 7 and 8 are driven at predetermined timings by the drive signals output from the CPU 5, and the air cylinders 7, 7 ... Are for opening and closing the discharge gate of the supply hopper. , 8 ... are for opening and closing the discharge gate 3 of the weighing hopper 2. And 9 is a storage unit. The storage unit 9 stores a target weight, a target number of combined hoppers, various constants and various programs. Further, 10 is an input unit. The input unit 10 is capable of instructing start and stop of the combination weigher and inputting a target weight, various kinds of constants and the like to the storage unit 9.

Next, an automatic setting device for loading detection points in the combination scale will be described. The load detection point automatic setting device is configured by the CPU 5, the storage unit 9, and a program previously written in the storage unit 9. That is, the CPU 5 calculates various loading values stored in the storage unit 9 according to a predetermined program, calculates a loading detection point, and sets the calculated loading detection point in the operation program of the combination weigher. It is equipped. That is, it is provided with a load detection point calculation means and a load detection point setting means for achieving this function.

The loading detection point calculation means multiplies the target combination hopper number NH by a constant a, and the multiplied value (the multiplied value is the total number of weighing tanks according to claims 1 or 2 or a number close thereto). And a constant b (the constant b is a correction value based on the total number of weighing tanks), the target weight TW is divided to calculate the loading detection point TD. That is, the loading detection point TD is

## EQU1 ## TD = TW / (a × NH + b) ... (1) Calculate. However, the upper limit value of the loading detection point TD is determined so that the weight detector 1 does not scale over when the additional supply of the goods is performed, and the load detection point TD is stored in the weighing hopper 2 that participates in the combination calculation. The lower limit of the load detection point TD is set in order to ensure the minimum weight of the article to be loaded. That is, TD upper limit = target supply weight WC for supplying articles to the weighing hopper 2 / constant c ... (2) TD lower limit = adhesion quantity d of articles to the weighing hopper 2 ... (3) ) Has been decided.

Here, the target combination hopper number NH is highly likely to be selected as a total value closest to the target weight among a plurality of total weight values (total values) calculated by variously combining the weighing signals. The number of weighing signals, that is, the number of weighing hoppers 2 corresponding to the weighing signals.

Now, for example, when using a combination weigher having, for example, 10 weighing hoppers 2 to perform combined weighing of an article having a total weight of 100 g, the weight of the articles to be supplied to each weighing hopper 2 (target supply weight). By setting the WC) to about 20 g so that the total weight of the articles supplied to the five weighing hoppers 2 becomes about 100 g, the articles can be weighed most accurately. This is because when the weighing signals output from the ten weighing hoppers 2 are combined in various ways to form a plurality of combinations, the number of sets of five weighing signals is the largest. As described above, selecting a combination having a total weight of about 100 g from the five combinations of weighing signals having the largest number of combinations is likely to select a combination relatively close to the target weight of 100 g. It is from. That is, if the number of the weighing hoppers 2 is 10, the half of the weighing hoppers 5, 5 is the target combination hopper number NH.

However, even when the total number of the weighing hoppers 2 is 10, there may be weighing hoppers 2 to which articles are not supplied during operation, and therefore the weighing hoppers that can actually participate in the combination can be weighed. Since the number of hoppers 2 is around 8, the number of halves 4 is generally set as the target combined hopper number NH. That is, the target combination hopper number NH 3 = total number of weighing hoppers NHO × 0.8 × (1/2) = NHO × 0.4.

The constant a is generally determined to be 2. That is, if the target combination hopper number NH is doubled, it becomes the total number of the weighing hoppers 2 or a value close thereto. When the target weight TW is divided by this 2 × NH, the value of 1/2 of the target supply weight WC to the weighing hopper 2 can be calculated. Now, for example, when the value of 1/2 of the target supply weight WC is set as the load detection point, the additional supply of the article is performed while the weighing hopper 2 is supplied with the article having a weight slightly smaller than the load detection point. When the command is issued, an article having a weight substantially equal to the weight of the article previously supplied is additionally supplied to the weighing hopper 2. This is because the weight of the articles supplied to the weighing hopper 2 does not change rapidly. Therefore, it is possible to achieve the purpose of supplying the weighing hopper 2 with an article having a substantially target supply weight WC, and the weight detector 1 does not cause scale over (overload). However, while the weighing hoppers 2 are being supplied with articles that are slightly heavier than the load detection points, no additional articles are supplied, but the total weight of the articles being supplied to all the weighing hoppers 2 is equal to or greater than the target weight. Therefore, the minimum weight of the articles to be supplied to the weighing hopper 2 can be secured. In this sense, it is significant to set the constant a to 2.

The constant b is a number determined based on the total number of weighing hoppers 2. That is, the total number of weighing hoppers 2 generally increases as the bulk density of the articles to be weighed decreases (the bulk increases). It is said that when an article having a low bulk density, that is, an article having a high bulk density is supplied to the weighing hopper 2, the supply amount (weight) varies more than when an article having a higher bulk density is supplied to the weighing hopper. It is known empirically. Therefore, it is necessary to reduce the load detection point as the total number of the weighing hoppers 2 increases so as not to cause an overscale when the articles are additionally supplied to the weighing hoppers 2. The constant b is determined based on the total number. Details of the constant b will be described with reference to the flowchart of FIG.

The constant c is usually set to 2. That is, the load detection point does not exceed 1/2 of the target supply weight WC to the weighing hopper 2. That is, when the load detection point TD is set to a value exceeding 1/2 of the target supply weight WC, the weight detector 1 may be overscaled when the article is additionally supplied.

The constant d is the weight of the article considered to be attached to the weighing hopper 2, and the attached amount is determined for each type of article. The loading detection point TD is calculated in principle by the equation (1), and the adhered amount of the article is not included in the equation (1). Therefore, it is not necessary to determine the adhered amount as strictly as in the conventional case, and this is a feature of the present invention.

The loading detection point setting means is for setting the loading detection point calculated or determined as described above in the operation program of the combination scale stored in the storage unit 9.

Next, the procedure for calculating and setting the load detection points by the automatic load detection point setting device in this combination weigher will be described with reference to the flowchart shown in FIG. The program corresponding to this flow chart is stored in the storage unit 9.

First, an operator operates the input unit 10 to set a target weight TW, a target number of combined hoppers N H (a value obtained by multiplying the total number of the weighing hoppers 2 by 0.4), constants a (= 2), c. (= 2), d (a predetermined number according to the type of article) and the total number HNO (= 10) of the weighing hoppers 2 are stored in the storage unit 9 (step 100). Then, the CPU 5 determines the constant b (correction value) based on the total number HNO of the weighing hoppers 2 (steps 102 to 110). That is, when the total number HNO is less than 9, b = 0 is determined, when the total number HNO is 9 or more and 12 or less, b = 1 is determined, and when the total HNO exceeds 12, b is determined. = 2 is determined. Next, TW, a, NH, and b are substituted into the equation (1) to calculate the loading detection point TD (step 112). Then, it is judged whether or not the calculated loading detection point TD is a value between the upper limit value WC / c and the lower limit value d (steps 114 and 118), and the loading detection point TD is set to the upper limit value WC /. When it exceeds c, it is determined that TD = WC / c (step 116), and when the load detection point TD is less than the lower limit value d, it is determined that TD = d (step 120), and the determined load is determined. The detection point TD is set in the storage unit 9 by storing it in the storage unit 9 (step 122). However, when the load detection point TD calculated in step 112 is between the upper limit value and the lower limit value, the calculated value is stored in the storage unit 9 to set (step 122). This completes the setting of the load detection point TD. The combination weigher determines the weighing hopper 2 to additionally supply the article and the weighing hopper 2 to participate in the combination calculation based on the set load detection points TD, and sequentially executes the operation.

However, in the above embodiment, the target number of combined hoppers NH = total number of weighing hoppers 2 is set to HNO × 0.4, but depending on the weighing speed of the combination weigher, the property of the article, the operating condition of the combination weigher, etc. You may change it. That is, for example, when the metering speed is relatively slow, NH = HNO × 0.5 can be set.

Then, the relation between the constant b and the total number HNO of the weighing hoppers 2 is set to the relation of steps 102 to 110 shown in FIG. 1, but the relation should be changed according to the weighing speed, the performance of the combination weigher and the like. You can Further, although the constant c = 2 is set, if the weight variation of the articles supplied to the weighing hopper 2 is large, it can be set to a value exceeding 2.

[0029]

[Effect of device]

 According to the automatic load detection point calculation device of the combination weigher of the first invention, when the total number of weighing tanks and the target weight of the combination weigher are determined, the operator is not at will and the appropriate load detection point is always automatically determined. The effect is that it can be calculated. That is, as in the conventional case, there is an effect that the loading detection point can be automatically calculated without considering the weight of the article attached to the weighing hopper. Then, by setting this appropriate load detection point on the combination weigher, the weight of the articles stored in each weighing tank can be kept within a predetermined range. As a result, it becomes possible to bring the total weight of the articles selected by the combination scale closer to the target weight than ever before. Therefore, the weighing accuracy (combined weighing accuracy) can be improved as compared with the conventional one, and the possibility of re-combination can be reduced, so that the weighing speed can be increased.

The automatic setting device for loading detection points in the combination weigher of the second invention has the effects of the first invention. Then, for example, when the target weight of the combination scale is changed, a newly automatically calculated load detection point can be automatically set in the combination scale, so that the labor of the operator can be reduced and This has the effect of preventing the operator from making setting mistakes.

[Brief description of drawings]

FIG. 1 is a flowchart showing a procedure for calculating and setting a load detection point by an automatic load detection point setting device in a combination weigher according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an electric circuit of the same automatic load detection point setting device in the embodiment.

[Explanation of symbols]

 1 Weight Detector 2 Weighing Hopper 5 CPU 9 Storage Section Step 112 Load Detection Point Calculation

Claims (2)

[Scope of utility model registration request] 1. A plurality of weighing means for weighing the weight of the articles supplied to each of the plurality of weighing tanks, and various combinations of the weighing values of these articles which are substantially equal to or higher than the load detection point. , A combination of total weight values equal to or close to a predetermined target weight is selected from those combinations,
In a combination weigher that supplies articles to weighing tanks that are less than the above-mentioned load detection points, the target weight is divided by the sum of the total number of the weighing tanks or a number close thereto and a correction value based on the total number of the weighing tanks. An automatic calculation device for load detection points in a combination scale for calculating the load detection points described above. 2. A plurality of weighing means for weighing the weight of the articles supplied to each of the plurality of weighing tanks are provided, and among the weighing values of these articles, various weighing values of the articles which are substantially equal to or higher than the load detection point are set. In the combination weigher that supplies the articles to the weighing tanks below the load detection point described above, the combination of the weighing tanks is selected from among the combinations. The load detection point calculation means for calculating the above-mentioned load detection point by dividing the target weight by the value of the sum of the total number or a number close thereto and the correction value based on the total number of the weighing tanks, and the calculated load detection point An automatic load detection point setting device in a combination scale, comprising: load detection point setting means for setting the combination scale.