JPH04109122A - Combination scale with operation constant automatic change function - Google Patents

Abstract

PURPOSE:To obtain the new optimum operation constant and operate a combination scale with the preset measurement precision and capability by calculating the number of effective hoppers when operation conditions are changed and the optimum operation constant to improve the measurement precision is changed from the original one. CONSTITUTION:The measurement signal of a weight detector 8-1 is amplified by an amplifier then fed to the A/D converter 15 of a control unit B via a multiplexer to be converted into the digital signal, then it is fed to an arithmetic controller 16. When the preset start signal is inputted to the controller 16 from a set display section 17, digital measurement signals of articles fed to measuring hoppers 6-1... are inputted in sequence, combination calculation is performed based on them, and the article to be discharged is determined. The driving device 18 of a measuing unit A is driven by a driving circuit 19 when respective gates are opened or closed to discharge or feed the articles in feed hoppers 5-1..., memory hoppers 9-1... and the hoppers 6-1... Linear feeders 3-1... are driven by a vibration control circuit 20.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention calculates the number of rooms (effective number of hoppers) containing weighing hoppers that accommodate articles participating in a combination, and calculates the number of effective hoppers or the average number of effective hoppers. The present invention relates to a combination weigher with an automatic operating constant change function that operates based on predetermined operating constants corresponding to the above.

[Conventional technology]

Some conventional combination weighers include a dispersion feeder 1 shown in FIG. 8 and a crosshead feeder 2 for feeding articles onto the dispersion feeder 1. There are a plurality of scales (P units) radially arranged around the dispersion feeder 1. linear feeder 3-1.3-2
. . . are provided, and when the vibrator 4-1 . And linear feeder 3-1...
A foot hopper 5-1 is provided at the tip of the hopper 5-1 to hold articles. Below these foot hoppers 5-1..., weighing hoppers 6-1... are provided, and when these are empty, the gates 7-1... of the foot hoppers 5-1... ...is opened and goods are supplied. These weighing hoppers 6-1・
... are respectively provided with weight detectors 8-1..., which detect the weight values of the articles supplied to the weighing hoppers 6-1... after a predetermined stable time has passed. Memory hoppers 9-1... are provided below the insides of these weighing hoppers 6-1..., and when these are empty,
Gate 11-1 inside the figure of weighing hopper 6-1...
...is opened and goods are supplied. These weighing hoppers 6-1... and memory hoppers 9-1
A combination calculation, etc. is performed on the weight values of the items in ... (This calculation is performed in a calculation unit, etc., but detailed explanation will be omitted.), and from which weighing hopper and memory hopper the items are discharged. For example, when weighing hopper 6-1 is selected, gate 1 outside the weighing hopper 6-1 in the figure is selected.
0-1 is opened, and the articles are supplied to a lower packaging machine 14, etc., through a dividing chute 12 and an inverted truncated cone-shaped gathering chute 13 under the weighing hopper 6-1. Also, when the memory hopper 9-1 consisting of the memory hopper 9-1 is selected, the memory hopper 9-1
The gate 14-1 is opened and the articles are fed to the packaging machine 14 via the lower dividing chute 12 and collecting chute 13.

In addition, if the total number of weighing hoppers and memory hoppers that accommodate the items participating in the combination calculation (the number of effective hoppers) is a certain number or more, the items will be stored in the preset number of hoppers (the upper limit of the number of effective hoppers). Combination calculations are performed on the weight values of the articles. The stability time from when the foot hopper gate begins to open until the weight detector begins to detect the weight value of the article, the opening time when the foot hopper gate opens, the opening time when the weighing hopper gate opens, and the memory hopper gate. Operating constants such as opening time are set in advance by the operator.

(Problem to be Solved by the Invention) Conventional combination scales have a system in which the total weight of the items selected by the combination calculation is The problem is to keep the total weight within the allowable range with a probability greater than a certain value, and to keep the number of recombinations performed when the total weight is not within the allowable range within a certain probability. In other words, when using a combination scale to weigh as much of the total weight of the selected items as possible per unit time, the mechanical conditions of the combination scale itself, the supply to each weighing hopper, etc. The upper limit of the effective number of hoppers, stabilization time, foot hopper gate opening time, weighing hopper gate opening time, and memory hopper gate opening time described in the above conventional example are optimal depending on the weight of the article to be weighed and the properties of the article to be weighed. The operator must select and set operating constants such as time.
For example, if the upper limit of the number of effective hoppers is increased, the number of effective hoppers that participate in the combination calculation increases, so that the weighing accuracy can be improved. However, if the value is increased beyond a certain value, the metering accuracy will not improve any further, and on the contrary, the calculation time will become longer, causing a decrease in the metering speed. For that reason,
It is necessary to set an appropriate upper limit value according to the number of weighing hoppers, etc.

However, since these operating constants are selected and set based on the experience and intuition of the operator, it is difficult to set the optimum operating constants and operate the combination weigher. Furthermore, even if the operator initially sets operating constants close to the optimum operating constants, the optimum operating constants may change during operation due to variations in the weight of goods supplied to the foot hopper, etc. For example, by measuring the total weight of the items that have been weighed one after another, an operator can observe changes in the weighing accuracy, measure the number of recombinations and the operating speed, and set the operating constants to the optimum value accordingly. Although it may be possible to fix the problem, this would place a heavy burden on the worker and would be difficult to ensure perfection. Therefore, this method cannot solve the above problem.

An object of the present invention is to provide a combination weigher with an automatic operating constant change function that solves the above problems.

(Summary of the Invention) The combination weigher with an automatic operating constant changing function of the present invention measures the weight of articles using a weighing hopper, and the combination calculation means calculates a desired total weight based on the weight of the articles weighed by the weighing hopper. Select a combination of items equal to or close to the weight of . Each time the combination calculation means selects a combination, the average value calculation means calculates the number of rooms that accommodate the weighed articles (hereinafter referred to as the "effective number of hoppers"), and the number of times this calculation has been made becomes a predetermined number of times. Then, calculate the average number of effective hoppers for this number of times. The reason why the number of effective hoppers is calculated in this way is that there is a close relationship between the number of effective hoppers and the operating constants related to weighing accuracy. In other words, if the operating conditions change and the optimal operating constant that improves metering accuracy changes from the initial one, the new optimal operating constant can be found by calculating the effective number of hoppers. Note that the reason for calculating the average value of the number of effective hoppers is to smooth out the unique number of each effective hopper and effectively set or change the operating constant. Then, the predetermined operation constant corresponding to the calculated average effective number of hoppers is selected from the storage means,
By automatically setting or changing, the combination scale can be operated with a predetermined weighing accuracy and weighing capacity.

In addition, without calculating the average value of the effective number of hoppers, a predetermined operating condition corresponding to the effective number of hoppers, which is one piece of data obtained by calculation, can be selected from various operating constants stored in the storage means. The combination balance can then be operated according to this selected operating constant.

(Example) In this example, the present invention is implemented in a memory-type automatic combination weigher, in which a distributed feeder 1, a linear feeder 3-1
..., foot hopper 5-1..., weighing hopper 6-1..., memory hopper 9-1..., dividing chute 12, and collection chute 13, and these configurations is equivalent to that shown in FIG. Therefore, detailed description thereof will be omitted, and equivalent parts will be described below using the same drawing symbols.

This embodiment has a metering unit A as shown in FIG. Although not shown in the figure, a plurality of weighing units A are actually provided. Weighing unit A includes a weighing hopper 6 equipped with a weight detector 8-i such as a load cell.
-1, foot hopper 5-1 and memory hopper 9-1
have.

The weighing signal from the weight detector 8-1 is amplified by an amplifier (not shown) and then supplied to the A/D converter 15 of the control unit B via a multiplexer (not shown), where it is converted into a digital signal. It is converted and supplied to the calculation control section 16. The arithmetic control unit 16 displays a predetermined activation signal in the setting display unit 1.
7, the digital weighing signals of the articles supplied to each weighing hopper 6-1, .

In addition, the articles weighed in the weighing hopper 6-1...
As explained in the conventional example, the memory hopper 9-1...
When the memory hopper is empty, it is supplied to the memory hopper 9-1 and stored therein. And these foot hoppers 5-
1..., memory hopper 9-1... and weighing hopper 6-1..., when opening and closing the respective gates when discharging or supplying articles, the gate drive of weighing unit A is used. This is performed by driving the device 18 with a drive circuit 19. In addition, the linear feeder 3-1 is controlled by the vibration control circuit 2°.
Drive...

Furthermore, a storage section 21 and a timer 22 are connected to the arithmetic control section 16. The storage unit 21 has a RAM and a ROM,
Programs corresponding to flowcharts to be described later and various operating constants related to measurement accuracy are written. This operating constant is determined by the upper limit of the number of effective hoppers that can participate in the combination as shown in Figures 6 (a) and (b) (if the number of effective hoppers is greater than the upper limit, the number of effective hoppers that can be accommodated is the upper limit). ), a stabilization time (the time it takes for the weighing signal to become stable, after which the weighing hopper weighs the articles), and a foot hopper 5-1... ..., weighing hopper 6-1...
. . . and memory hopper 9-1. These operating constants are based on different ranges that the average effective number of hoppers A can take (A<n, n≦A<
n+1, n+1≦A<n+2. n+2≦A, where n
is a threshold value and a predetermined constant. ).

The timer 22 is composed of a plurality of counters each counting down clock pulses from a set value proportional to the set time limit, and when the count value reaches 0, the set time limit is reached.

Further, the arithmetic control section 16 includes an average value calculation means and an operating constant setting means. The average value calculation means calculates the total number of weighing hoppers and memory hoppers (effective number of hoppers) that accommodate weighed articles each time a combination is selected,
The information is stored in the storage unit 21 as shown in FIG. Then, when the number of times the number of effective hoppers has been calculated reaches a predetermined number N, the average number A of effective hoppers for the N times is calculated. The operating constant calculation means stores operating constants corresponding to the range including the calculated average effective number of hoppers in the storage unit 2.
1, and operate the combination weigher based on the selected operating constant.

The outline of this control will be explained according to the timing chart shown in FIG. However, the combination calculation start time of each cycle shown in the figure is 1. ．． 13, t5 is determined by the operating speed of this combination scale, and if the operating speed is constant, even if the operating constant setting means automatically changes each operating constant, the cycle will not change. not be done, and
Weighing hopper 6-1 and memory hopper 9-1,...
The weighing hopper 6-P and the memory hopper 9-p are provided vertically in pairs as shown in FIG. 8, respectively.

In addition, the time zone drawn with a solid line indicates that articles are stored in the corresponding hopper.At the time t1, all weighing hoppers 6-1 to a-p and memory hopper 9-
Measured articles are stored in boxes 1 to 9-p.

Next, a combinatorial operation is performed such that, for example, weighing hopper 6-
1.6-p, memory hopper 9-2.9-p is selected, and each gate opens to discharge the article to the packaging machine 14 side.
Then, when a predetermined opening time has elapsed, each gate closes, and articles are supplied to the weighing hopper 6-1.6-p from the corresponding foot hopper 5-1.5-p, and the foot hopper 5-1.5 -p is supplied with articles from the linear feeder 3-1.3-p. Then, since the memory hopper 9-2 is empty, the goods in the weighing hopper 6-2 are supplied.
Feet hopper 5-2 is placed in empty weighing hopper 6-2.
Goods are supplied from Furthermore, when the weighing of the article is completed after a stable period of time has elapsed since the article was supplied, the weighing hopper 6-p supplies the article to the empty memory hopper 9-p.

Note that the weighing hopper weighs the supplied article after a predetermined stable time has elapsed since the foot hopper started supplying the article.

Then, at the combination calculation start time t3 of the next cycle, the weighing hopper 6-1. Memory hopper 9-1.9-2
．． A combination calculation is performed based on the weighed weights of the articles stored in the respective weighing hoppers 9-P and the weights of the articles stored in other weighing hoppers (not shown). Then, the article selected by this combination calculation is discharged, and the same operation as described above is performed.

However, the total weight selected as a result of the combination calculation is determined by the priority order according to the area A, area B, area C, area D, and area E shown in FIG. 5 where the total weight exists.
The priority order is A, B, C, D (E). In other words,
If a plurality of total weights exist in areas A, B, and C, the weight closest to the target weight is selected from the total weights existing in area A. In addition, A, B,
C is an appropriate amount range, D is an excessive amount range, and E is a light amount range. Each time the total weight is selected, the average value calculating means calculates the average effective number of hoppers, and the operating constant setting means sets an operating constant corresponding to the calculated average effective hopper number.
Activate the combination scale.

Next, the procedure for changing the operating constants of the memory-type automatic combination weigher will be explained according to the flowchart shown in the tJ1 diagram. First, the operator operates the setting display section 17 to set the upper limit of the number of effective hoppers participating in the combination, which are operating constants, the stabilization time, and the opening time of each gate of the foot hopper, weighing hopper, and memory hopper (Step 1 (10), these operating constants are, for example, m, a shown in step 2 of FIG.
,,b,,C2,d2. Next, the linear feeder is driven, the gate of the foot hopper is driven to open and close, and the gate of the metering and weighing hopper is driven to open and close until the combination calculation start time M tr shown in FIG. 3 is reached (step 102). Then, when the combination calculation start time t1 comes (step 104), it is determined whether the combination calculation end flag is ON or not (step 106).
When the articles selected for the previous combination are discharged and the combination operation end flag is OFF, the total number of weighing hoppers and memory hoppers that accommodate weighed articles (the number of effective hoppers) and the number of each of these accommodated articles are displayed. Weight storage section 2
1 (step 108), and then, based on the weights of these weighed articles, select the total weight that meets the priority order regulations in FIG. 5 and is closest to the target weight (step 110). The reason for determining whether the combination calculation end flag is OFF before performing the combination calculation is to prevent the next combination from being selected before the items selected by the combination are discharged. , is necessary when the reception of the packaging machine 14 is delayed for some reason. Therefore, steps 102 to 106 or steps 102, 104, and
126 is repeated.Next, it is determined in which region the total weight selected by the combination calculation exists in the regions A to A shown in FIG. 5 (steps 112, 116, 1).
18).

If it is determined that the total weight is in the E area (weighing range) below the lower limit weight, a command to reload is issued (step 114).
, return to step 102 if the total weight is A or B area (
If it is determined that the amount is within the appropriate amount range, the one combination calculation completion flag is turned on (step 120).

Further, if it is determined that the total weight is in the C area and the appropriate amount range is large, the counter value P of the number of poor combinations is incremented by 1 (step 122), and the process proceeds to step 120, and the total weight is in the D area ( If it is determined that the selected item is within the appropriate amount range (step 124), the item participating in the selection is discharged as the appropriate amount item (step 124), and the process returns to step 102.

Note that if the total weight is determined to be light (region E) in step 112 or excessive (region D) in step 118, the process continues in step 102 until the next combination calculation start time (for example, t) comes. , 1 (14, 126
is executed to weigh the article, and when time t3 comes, the combination calculation is executed in the same manner as above. In addition, if the total weight is determined to be an appropriate amount (A, B, C area) in steps 116 and 118, step 120 or 122 is executed and the process proceeds to step 134, and the effective number of hoppers is calculated N times. Step 134) to determine whether or not the number of effective hoppers has been carried out N times, step 136) to calculate the average value A of the number of effective hoppers for N times. Set (step 138
), at this time, each count value of the number N of calculations of the number of effective hoppers and the number P of inferior combinations is reset to O. and,
Returning to step 102, since the combination calculation time has elapsed, step 104 is NO, and since the combination completion flag is ON, step 126 is YES. In other words, if the articles are fed and weighed until the discharge signal is received from the packaging machine 14, and the discharge signal is received (step 12).
B) Discharge the selected article to the packaging machine 14 (Step E30) and turn off the combination calculation completion flag (
Step 132).

Then, the process returns to step 102, where the articles are weighed and a combination calculation is performed. Note that if the number of times the effective hopper number was calculated in step 134 has not reached N times, and the answer is NO, the process returns to step 102 and the same steps as described above are executed.

Next, the operating constant setting procedure in step 138 will be explained in detail with reference to the flowchart of FIG. First, it is determined whether P/N≧α (step 200), where P is the number of inferior combinations, and the number of inferior combinations counted until the effective number of hoppers is calculated N times (selected total Weight is C
α is the threshold value. Then, if it is determined that P/N≧α and the number of inferior combinations is relatively large, then the average effective number A of hoppers is A<n, n≦A<n+1
, n+1≦A<n+2 and other ranges (n
+2≦A) to determine which range it belongs to (
Step 202. , 204 , 206 ), A<
If n, the upper limit of the number of valid hoppers participating in the combination is set to 2 as shown in FIG. 6(b), and (step 20B)
No other operating constants will be changed. Similarly, n≦A<n
+1. If n+1≦A<n+2 or n+2≦A, set the upper limit to intersection+1, sentence+2, or look+3, respectively (
Steps 210, 212, 214).

Then, each count value of the data number N of the number of effective hoppers and the number of inferior combinations P is reset to O.

In addition, if it is determined in step 200 that P/N<α and the number of poor combinations is relatively small, the average effective number of hoppers is A or A<n, n≦A<n+1, n+1≦A<n+2, and other ranges. Determine which range it belongs to (n+2≦A) (steps 218, 220, 222)
), if A<n, the upper limit of the number of effective hoppers participating in the combination is set as m, and the stabilization time is set as 8, as shown in Fig. 6(a).
1, and the opening times of the foot hopper, weighing hopper, and memory hopper are set to b□, 1, and dl (step 224). Similarly, n≦A<n+1. n+1≦A
If <n+2 or n+2≦A, each operating constant is set to the value shown in FIG. 6(a). Then, each count value of the data number N of the number of effective hoppers and the number of inferior combinations P is set to 0.
(Step 2I5).

However, there is a relationship of n<m and n<1. This is to make the upper limit of the number of effective hoppers participating in the combination larger than the average number of effective hoppers. The values of n, 1, and m are determined based on the number of weighing hoppers and memory hoppers of the combination weigher.

In the above embodiment, only the upper limit of the number of effective hoppers participating in the combination is changed (steps 202 to 214), depending on the area to which the average number of effective hoppers belongs, or the upper limit, the stabilization time, and the opening time of each hopper are changed. I changed everything (step 21)
8 to 230), in steps 202 to 214, other operating constants related to weighing accuracy can be changed instead of the upper limit value, and in steps 218 to 230
Instead of the above-mentioned operating constants, for example, only the stabilization time can be changed.

Then, in steps 136 and 138, the average number of effective hoppers is calculated, and whether the average number of effective hoppers is set or changed, or the operation constant corresponding to the area to which the average number of hoppers belongs is calculated for the Nth time without calculating the average number of effective hoppers. The operating constant corresponding to the area to which the effective number of hoppers belongs can be set or changed.

The embodiments described above are applied to a combination weigher having a memory hopper, or can also be applied to a combination weigher not having a memory hopper.

〔Effect of the invention〕

The present invention is applicable to cases where the operating constants related to weighing accuracy set before the combination weigher is in operation are different from the optimum operating constants during operation, or the weight of the articles or the properties of the articles supplied to each weighing hopper during the operation of the combination weigher. If the optimum operating constants related to weighing accuracy change due to changes in operating conditions such as This has the effect of allowing articles to be weighed with high weighing accuracy. In addition, since the operating constants can be changed automatically, highly accurate weighing can be performed without placing any burden on the operator. In addition, since it is possible to perform accurate weighing, it is possible to reduce the number of recombinations, thereby increasing the number of times per unit time for discharging items whose combined weight is within the allowable range and recombining. It is possible to increase the number of times articles whose combined weight is within the permissible range per predetermined number of calculations are discharged (improvement in yield).

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the operation of a combination weigher with an automatic operating constant changing function according to one embodiment of the present invention, FIG. 2 is a flowchart for setting or changing the operating constant to a predetermined value, and FIG. A time chart showing the operation of the combination scale with an automatic operation constant change function according to the embodiment, Fig. 4 is a block diagram of the combination scale with an automatic operation constant change function according to the embodiment, and Fig. 5 shows the combination calculation result judgment of the embodiment. Figures 6(a) and 6(b) are diagrams showing the operating constants of the same embodiment, Figure 7 is a diagram showing the storage section for storing the effective number of hoppers in the same embodiment, and Figure 8 is a diagram showing the area. It is an external view of the combination balance of the same Example and a conventional example. 6-1 to 6-P...Measuring hopper, 16...Calculation control section, 17...Setting display section, 21...Storage section.

Claims (2)

[Claims] (1) A combination of a plurality of weighing hoppers each supplied with articles and weighing the supplied articles, and articles whose total weight is equal to or close to a desired weight based on the weight of the articles weighed by the weighing hoppers. and a combination calculation means for selecting the combination, and each time the combination is selected, the total number of rooms including the weighing hoppers that accommodate the weighed articles (hereinafter referred to as the "effective number of hoppers") is calculated, and the effective number of hoppers is calculated. an average value calculation means for calculating the average number of effective hoppers for the number of times when the number of times reached a predetermined number, and a weighing accuracy of this combination scale corresponding to each different range that the average number of effective hoppers can take. a storage means for storing operating constants related to the above, and a storage means for storing the operating constants corresponding to the range including the average effective hopper number based on the calculated average effective hopper number; A combination weigher with an automatic operating constant changing function, comprising an operating constant setting means that selects from each operating constant and operates the combination weigher based on the selected operating constant. (2) A combination of a plurality of weighing hoppers each supplied with articles and weighing the supplied articles, and articles whose total weight is equal to or close to a desired weight based on the weight of the articles weighed by the weighing hoppers. a combination calculation means for selecting the weighing hopper, an effective hopper number calculation means for calculating the total number of rooms including the weighing hoppers that accommodate the weighed articles (hereinafter referred to as the "effective number of hoppers"), and a calculation means for calculating the effective number of hoppers. a storage means for storing operating constants related to the weighing accuracy of the combination scale in association with each different range obtained;
Based on the calculated effective hopper number, select the operating constant corresponding to the range that includes this effective hopper number from among the operating constants stored in the storage unit, and based on the selected operating constant. A combination scale with an operation constant automatic change function, which is equipped with an operation constant setting means for operating the lever combination scale.