JP2978218B2 - Combination weigher with automatic change of operation constant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention calculates the number of rooms (effective hoppers) including a weighing hopper for accommodating 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 having an operation constant automatic change function which is operated based on a predetermined operation constant corresponding to the following.

(Prior Art) A conventional combination weigher includes a dispersion feeder 1 shown in FIG. 8 and a crosshead feeder 2 for supplying articles onto the dispersion feeder 1. A plurality (P units) of linear feeders 3-1 and 3-
When the vibrator 4-1 # vibrates, the article supplied from the dispersion feeder 1 is conveyed to the tip side. A feed hopper 5-1 # is provided at the end of the linear feeder 3-1 #, and can hold articles. These feed hoppers 5-1
Below ‥‥, weighing hoppers 6-1 ‥‥ are provided, respectively, and when these are empty, the gate 7-1 ‥‥ of the feed hopper 5-1 開 か is opened to supply articles. Each of these weighing hoppers 6-1 ‥‥ has a weight detector 8-
1} is provided, and detects the weight value of the article supplied to the weighing hopper 6-1 # after a predetermined stabilization time has elapsed. Memory hoppers 9-1 # are provided below the inside of these weighing hoppers 6-1 #, respectively.
The gate 11-1 # inside the figure of the weighing hopper 6-1 # is opened, and articles are supplied. Then, a combination calculation or the like is performed on the weight values of the articles in the weighing hopper 6-1 # and the memory hopper 9-1 # (this calculation is performed by a calculation unit or the like, but detailed description is omitted. If the weighing hopper and the memory hopper from which the articles are to be discharged are selected, for example, if the weighing hopper 6-1 is selected, the gate 10-1 outside the drawing of the weighing hopper 6-1 is opened. Then, the article is supplied to the lower packaging machine 14 and the like via the lower split chute 12 and the inverted frustoconical collecting chute 13 on the weighing hopper 6-1. When a certain memory hopper 9-1 is selected, the gate 14-1 of the memory hopper 9-1 is opened, and
The article is supplied to the packaging machine 14 through the lower split chute 12 and the lower chute 13.

When the total number of the weighing hoppers and the memory hoppers (the number of effective hoppers) that accommodate the articles participating in the combination calculation is equal to or more than a certain value, the hoppers of a predetermined number (the upper limit of the number of the effective hoppers) are stored. A combination operation is performed on the weight value of the article being performed. Then, the stabilization time from when the feed hopper gate starts opening until the weight detector starts detecting the weight value of the article, the opening time of the feed hopper gate, the opening time of the weighing hopper gate, and the gate of the memory hopper are The operating constant such as the opening time is set in advance by the operator.

(Problems to be Solved by the Invention) In a conventional combination weigher, the total weight of the articles selected by the combination calculation at a certain operating speed or more (the number of times of selection of the articles by the combination calculation per unit time) is given. The problem is that the number of recombinations performed when the total weight is not within the allowable range is within a certain level or less.
In other words, when using a combination weigher to weigh as much as possible the total weight of selected articles as appropriate per unit time, the mechanical conditions of the combination weigher itself, the articles supplied to each weighing hopper, etc. The upper limit of the number of effective hoppers, the stable time, the gate opening time of the feed hopper, the gate opening time of the weighing hopper, the gate opening time of the memory hopper, etc. The operator must select and set the operating constant of For example, if the upper limit value of the number of effective hoppers is increased, the number of effective hoppers participating in the combination calculation increases, so that the weighing accuracy can be improved. However, if the value is increased by a certain value or more, the weighing accuracy will not be further improved, and conversely, the calculation time will be long, and the weighing speed will be reduced. Therefore, it is necessary to set an appropriate upper limit according to the number of weighing hoppers and the like.

However, since these operating constants are selected and set based on the experience and intuition of the operator, it is difficult to set the optimal operating constants and operate the combination weigher. In addition, even if the operator can set an operation constant close to the optimum operation constant at first, the optimum operation constant during operation may change due to a variation in the weight of the articles supplied to the feed hopper. For example, by measuring the total weight of sequentially weighed articles, the operator observes a change in the weighing accuracy, measures the number of reassembly times and the operation speed, and sets the operation constant to an optimal one according to these. It can be fixed, but this puts a heavy burden on the workers and it is difficult to achieve perfection. Therefore, the above problem cannot be solved by such a method.

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

(Summary of the Invention) In a combination weigher having an operation constant automatic change function according to the present invention, a weighing hopper measures the weight of an article, and a combination calculating means calculates a desired weight based on the weight of the article weighed by the weighing hopper. A combination of articles that are close to this is selected. Every time the combination calculating means selects a combination, the average value calculating means calculates the number of rooms for accommodating the weighed articles (hereinafter referred to as the "effective number of hoppers"), and the calculated number becomes a predetermined number. At this time, the average number of effective hoppers for this number is calculated. The reason for calculating the number of effective hoppers is that there is a close relationship between the number of effective hoppers and the operating constant related to the measurement accuracy. In other words, when the operating conditions change and the optimum operating constant for improving the weighing accuracy changes from the initial one, the new optimum operating constant can be known by calculating the number of effective hoppers. In addition,
The reason why the average value of the number of effective hoppers is calculated is to set or change the operation constants effectively by arranging a unique one among the numbers of the effective hoppers. Then, the combination weigher can be operated with a predetermined weighing accuracy and weighing ability by selecting the predetermined operating constant corresponding to the calculated average number of effective hoppers from the storage means and automatically setting or changing the operating constant.

Also, without calculating the average value of the number of effective hoppers, a predetermined operating condition corresponding to the number of effective hoppers, which is one data obtained by calculation, is selected from various operating constants stored in the storage means. Then, the combination weigher can be operated according to the selected operation constant.

(Example) In this example, the present invention is applied to a memory-type automatic combination weigher.
1 ‥‥, Feed hopper 5-1 ‥‥, Weighing hopper 6-1
メ モ リ ー, a memory hopper 9-1 ‥‥, a split chute 12 and a collective chute 13, and these components are the same as those shown in FIG. 8. Therefore, the detailed description is omitted, and the same parts are described below using the same reference numerals.
This embodiment has a weighing unit A as shown in FIG. Although not shown in the figure, a plurality of weighing units A are actually provided. The weighing unit A includes a weighing hopper 6 having a weight detector 8-1 such as a load cell.
-1, feed 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 an A / D converter 15 of the control unit B via a multiplexer (not shown), where the signal is converted into a digital signal. It is converted and the operation control unit 16
Supplied to When a predetermined activation signal is input from the setting display unit 17, the arithmetic control unit 16 sequentially inputs the digital weighing signals of the articles supplied to the respective weighing hoppers 6-1 #, and performs the combination calculation based on these. To determine the goods to be discharged. The articles weighed by the weighing hopper 6-1 # are stored in the memory hopper 9-1 # as described in the conventional example.
Are empty and supplied to and stored in the memory hopper 9-1 #. And these feed hoppers 5-1 @
‥, memory hopper 9-1 ‥‥ and measuring hopper 6-1 ‥
To open or close each gate when discharging or supplying the articles in the box, the gate driving device 18 of the weighing unit A is driven by the driving circuit 19. Also, the vibration control circuit
20 drives the linear feeder 3-1 #. Further, a storage unit 21 and a timer 22 are connected to the arithmetic control unit 16. The storage unit 21 has a RAM and a ROM, in which programs corresponding to flowcharts described later and various operation constants related to the measurement accuracy are written. As shown in FIGS. 6 (a) and 6 (b), the operating constant is an upper limit value of the number of effective hoppers to participate in the combination (when the number of effective hoppers is equal to or more than the upper limit value,
The articles stored in the effective hoppers of the upper limit number are allowed to participate in the combination. ), Stabilization time (time until the weighing signal stabilizes, after which time the weighing hopper weighs the article), and feed hopper 5-1
計量, weighing hopper 6-1 ‥‥ and memory hopper 9-1
‥‥ consists of each gate opening time. These operating constants are in different ranges (A <n, n ≦ A <n + 1, n + 1 ≦ A <n + 2, n +
2 ≦ A, where n is a threshold value and is a predetermined constant. ) Are determined in correspondence with each other.

The timer 22 is composed of a plurality of counters that count down the clock pulse from a set value proportional to the set time period, and when the count value becomes 0, the set time period is reached.

Further, the arithmetic and control unit 16 includes an average value calculating unit and an operation constant setting unit. The average value calculating means calculates the total number (effective number of hoppers) of the weighing hoppers and the memory hoppers that store the weighed articles each time a combination is selected,
It is stored in the storage unit 21 as shown in FIG. Then, when the number of times the number of effective hoppers is calculated reaches a predetermined number N, the average number of effective hoppers A for the N times is calculated. The operating constant calculation means selects an operating constant corresponding to the above-mentioned range including the calculated average effective hopper number from the respective operating constants stored in the storage unit 21 and assigns the selected operating constant to the selected operating constant. The balance is activated based on this.

The outline of this control will be described with reference to the timing chart shown in FIG. However, the combination calculation start times t ₁ , t ₃ , and t ₅ of each cycle shown in the figure are determined by the operation speed of the combination weigher, and when the operation speed is constant, the operation constant setting is performed. Even if the means automatically changes each operation constant, the cycle is not changed. The weighing hopper 6-1 and the memory hoppers 9-1,..., And the weighing hopper 6-p and the memory hopper 9-p are provided in pairs vertically as shown in FIG. Further, the time zone drawn by the solid line indicates that the article is stored in the corresponding hopper. Now, the time point t ₁ is weighed articles all weighing hoppers 6-1 to 6-p and memory hoppers 9-1 to 9-p are accommodated.

Next, a combination calculation is executed, for example, the weighing hopper 6
-1, 6-p and the memory hoppers 9-2, 9-p are selected, and each gate is opened to discharge the articles to the packaging machine 41 side.
Then, when a predetermined opening time has elapsed, each gate closes, and articles are supplied to the weighing hoppers 6-1 and 6-p from the corresponding feed hoppers 5-1 and 5-p, respectively. -P is supplied with articles from the linear feeders 3-1 and 3-p. Since the memory hopper 9-2 is empty, the articles of the weighing hopper 6-2 are supplied,
The empty weighing hopper 6-2 has a feed hopper 5-2.
Supplies the goods. Further, the weighing hopper 6-p supplies the article to the empty memory hopper 9-p when the weighing of the article is completed after the stable time has elapsed since the article was supplied.

The weighing hopper supplies the supplied article after a predetermined stabilization time has elapsed since the supply of the article from the feed hopper.

Then, in the next cycle combination calculation start time t _3, the weighing hoppers 6-1, memory hopper 9-1,9-
The combination calculation is performed based on the weights of the articles stored in 2, 9-p and the weights of the articles stored in other weighing hoppers and the like (not shown). Then, the articles selected by this combination operation are discharged,
Hereinafter, the same operation as described above is performed.

However, the total weight selected as a result of the combination operation is
The priorities are determined by the areas A, B, C, D, and E shown in FIG. 5 where the total weight exists, and the priorities are in the order of A, B, C, D (E). . That is, when a plurality of total weights exist in the areas A, B, and C, the weight closest to the target weight is selected from the total weights existing in the area A. A,
B and C are appropriate ranges, D is an excess range, and E is a lightweight range. Then, every time the total weight is selected, the average value calculating means calculates the average number of effective hoppers, and the operation constant setting means sets an operation constant corresponding to the calculated average effective hopper number, and activates the combination weigher. .

Next, a procedure for changing the operating constant of the memory-type automatic combination weigher will be described with reference to the flowchart of FIG. First, the operator operates the setting display unit 17 to set the upper limit value of the number of combination participation effective hoppers which are operation constants, the stabilization time, and the gate opening times of the feed hopper, the weighing hopper, and the memory hopper (step 100). ). These operating constants are, for example, m, a ₂ , b ₂ , c ₂ ,
It can be set to d _2. Next, the driving of the linear feeders, the gate opening and closing of the feed hopper, the gate opening and closing of the metering and weighing hoppers performed until the combination calculation start time t ₁ shown in FIG. 3 (step 102). Then, at the combination calculation start time t ₁ (step 104), the combination calculation end flag is determined whether it is ON (Step 10
6) When the product selected in the previous combination is ejected and the combination calculation end flag is OFF, the total number (effective number of hoppers) of the weighing hoppers and the memory hoppers storing the weighed products and the number of the stored products. Are stored in the storage unit 21 (step 108). Then, based on the weights of these weighed articles, a total weight that conforms to the priority order shown in FIG. 5 and is closest to the target weight is selected (step 110). It is necessary to determine whether the combination calculation end flag is OFF before performing the combination calculation as described above.
This is for preventing the next combination from being selected before the article selected by the combination is discharged, and 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 are repeated until the combination selected article is discharged and the combination calculation end flag is turned off. Next, it is determined which of the areas A to D shown in FIG. 5 the total weight selected by the combination calculation exists (step 11).
2, 116, 118). If it is determined that the total weight is in the area E (weighing range) smaller than the lower limit weight, a re-input command is issued (step 114), and the process returns to step 102. Total weight is A or B
If it is determined that it is in the area (appropriate amount range), the combination calculation completion flag is turned ON (step 120). When it is determined that the total weight is in the area C and the eye has a large suitable amount range, the counter value P of the number of poor combinations is incremented by 1 (step 12).
2) Go to step 120. If it is determined that the total weight is in the D region (excess area), the articles participating in the selection are ejected as excessive articles (step 124), and step 1 is executed.
Return to 02.

When the total weight is determined to be the weighing (E area) in step 112 and when the total weight is determined to be excessive (D area) in step 118, the next combination calculation start time (for example,
t ₃₎ were weighed articles by performing the steps 102,104,126 to come, to perform combination calculation in the same manner as described above when it came time t _2. If the total weight is determined to be an appropriate amount (A, B, C areas) in steps 116 and 118, step 120 or 122 is executed, and the process proceeds to step 134 to determine whether the number of effective hoppers has been calculated N times. Is determined (step 134),
If it has reached N times, the average value A of the number of effective hoppers for N times
Is calculated (step 136), and an operation constant is selected from the storage unit 21 and set based on the average value A (step 13).
8). At this time, the count values of the number of effective hopper calculations N and the number of poor combinations P are reset to zero. And
Returning to step 102, at this time, step 104 is NO because the combination calculation time has elapsed, and step 126 is YES because the combination completion flag is ON. In other words, the articles are supplied and weighed until a discharge signal is received from the packaging machine 14,
Upon receiving the ejection signal (step 128), the selected article is ejected to the packaging machine 14 (step 130), and the combination calculation completion flag is turned off (step 132). Then, the process returns to step 102 again to measure the articles and execute the combination calculation. If the number of times of calculating the number of effective hoppers in step 134 has not reached N, and if NO, the process returns to step 102 and executes the same steps as described above.

Next, the operation constant setting procedure of step 138 will be described in detail with reference to the flowchart of FIG. First, it is determined whether P / N ≧ α (step 200). Here, P is the number of sub-combinations, and is the number of sub-combinations counted until the number of effective hoppers is calculated N times (the number of times the selected total weight is in the C region). α is a threshold value. And P / N
If it is determined that ≧ α and the number of poor combinations is relatively large, the average number of effective hoppers A is A <n, n ≦ A <n + 1, n + 1 ≦
It is determined which of the range A <n + 2 and the other range (n + 2 ≦ A) belongs (steps 202 and 204,
206). If A <n, as shown in FIG. 6B, the upper limit value of the number of effective hoppers for combination participation is set to 1 (step 208), and other operation constants are not changed. Similarly,
If n ≦ A <n + 1, n + 1 ≦ A <n + 2 or n + 2 ≦ A, the upper limit is set to l + 1, l + 2 or l + 3, respectively (steps 210, 212, 214). Then, each count value of the data number N of the effective hopper number and the number P of the sub-combinations is reset to zero.

If it is determined in step 200 that P / N <α and the number of poor combinations is relatively small, the average number of effective hoppers A is A <A
It is determined which of n, n ≦ A <n + 1, n + 1 ≦ A <n + 2, and any other range (n + 2 ≦ A) (steps 218, 220, 222). If A <n, as shown in FIG. 6 (a), the upper limit value of the number of effective hoppers for combination participation is m, the stabilization time is a ₁ , and the opening time of each of the feed hopper, the weighing hopper and the memory hopper is
b _1, is set to c _1, d ₁ (step 224). Similarly, n ≦
When A <n + 1, n + 1 ≦ A <n + 2 or n + 2 ≦ A, each operation constant is set to the value shown in FIG. 6 (a). Then, the count values of the data number N of the effective hopper number and the number P of the sub-combinations are reset to 0 (step 21).
6).

However, there is a relationship of n <m and n <l. This is to make the upper limit value of the number of effective hoppers for combination participation larger than the average number of effective hoppers. Then, the values of n, l, and m are determined based on the number of weighing hoppers and memory hoppers of the weighing scale.

In the above embodiment, only the upper limit value of the number of effective hoppers to be combined is changed according to the area to which the average number of effective hoppers belongs (steps 202 to 214), and the upper limit value, the stable time, and the open time of each hopper are all changed. Changed (steps 218-230)
In Steps 202 to 214, other operating constants relating to weighing accuracy can be changed instead of the upper limit value, and in Steps 218 to 230, for example, only the stabilization time can be changed instead of the operating constant. .

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

In the above embodiment, the present invention is applied to a combination weigher having a memory hopper, but may be applied to a combination weigher having no memory hopper.

(Effects of the Invention) According to the present invention, an operation constant related to weighing accuracy set before operation of a combination weigher is different from an optimum operation constant during operation or an article supplied to each weighing hopper during operation of the combination weigher When the operating conditions such as weight or property of the article change and the optimal operating constant related to the weighing accuracy changes, the currently set operating constant can be automatically changed to the optimal operating constant. There is an effect that articles can be weighed with good weighing accuracy that is aimed at in advance. Since the operation constant can be automatically changed, accurate measurement can be reliably performed without imposing a burden on the operator. In addition, since accurate weighing can be performed, the number of times of reassembly can be reduced, thereby improving the number of times per unit time to discharge articles whose combination weight is within an allowable range and performing combination calculation. It is possible to improve the number of times of discharging articles whose combination weight per predetermined number is within the allowable range (improve the yield).

[Brief description of the drawings]

FIG. 1 is a flowchart showing the operation of a combination weigher having an automatic changing function of an operating constant according to an embodiment of the present invention, FIG. 2 is a flowchart for setting or changing the operating constant of the embodiment to a predetermined value, and FIG. FIG. 4 is a time chart showing the operation of the combination weigher with automatic operation constant changing function of the embodiment, FIG. 4 is a block diagram of the combination weigher with automatic operation constant change function of the embodiment, and FIG. FIGS. 6A and 6B show operating constants of the embodiment, FIG. 7 shows a storage unit for storing the number of effective hoppers of the embodiment, and FIGS. It is an external view of the combination weigher of the example and the conventional example. 6-1 to 6-P: weighing hopper, 16: arithmetic control unit, 17
... setting display section, 21 ... storage section.

Continuation of front page (56) References JP-A-62-2228 (JP, A) JP-A-62-42020 (JP, A) JP-A-62-103524 (JP, A) JP-A-1-113621 (JP) JP-A-61-278717 (JP, A) JP-A-63-171324 (JP, A)

Claims (2)

(57) [Claims] 1. A plurality of weighing hoppers each of which is supplied with an article and weighs the supplied article, and a total weight equal to or equal to a desired weight based on the weight of the article weighed by the weighing hopper. Combination calculation means for selecting a combination of close articles and the total number of rooms including the weighing hoppers accommodating the weighed articles each time the combination is selected (hereinafter referred to as "effective hopper number") are calculated. When the number of times of calculation of the number of hoppers becomes a predetermined number of times, an average value calculating means for calculating an average number of effective hoppers for this number of times,
An operation for changing the number of effective hoppers subsequent to the next and subsequent times relating to the weighing accuracy of the combination weigher according to the average effective hopper number calculated this time, which corresponds to each different range of the average effective hopper number that can be taken. Storage means for storing constants; and the operating constants stored in the storage means, the operating constants corresponding to the range including the average effective hopper number based on the calculated average effective hopper number. A combination weigher having an operation constant automatic change function, comprising: operating constant setting means for operating the combination weigher based on the selected operation constant. 2. A plurality of weighing hoppers each of which is supplied with an article and weighs the supplied article, and an article whose total weight is equal to or close to a desired weight based on the weight of the article weighed by the weighing hopper. Combination operative means for selecting a combination of the above, effective hopper number calculation means for calculating the total number of rooms including the weighing hoppers accommodating the weighed articles (hereinafter referred to as "effective hopper number"), and the effective hopper number A storage means for storing an operating constant for changing the effective hopper number from the next time onward relating to the weighing accuracy of the combination weigher according to the effective hopper number calculated this time, corresponding to each different range that can be taken. And storing the operating constant corresponding to the range including the effective hopper number in the storage means based on the calculated effective hopper number. Operation constants automatic change function combination weigher having a operating constant setting means for operating the combination weigher based selected from the driver constant to the selected operation constant.