JP3446114B2 - Weight sorter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weight sorting device for weighing objects to be weighed, which are filled in a container by a filling machine, and to a technique for accurately grasping the filling state.

[0002]

2. Description of the Related Art A weight sorter measures the weight of an object to be weighed, which is filled in a container by a filling machine, determines whether the measured value is within the non-defective range, and determines whether the measured value is within the non-defective range. It is configured to sort objects and objects out of range.

In such a weight sorting apparatus equipped with a filling machine, it is necessary to adjust the filling machine in advance so that the objects to be weighed can enter the non-defective range with a high probability.

For this adjustment, for example, the weight sorting device is actually put in an operating state, and the operating state of the filling machine is set so that the average value of the weighing results is in the approximate center of the non-defective product range.

[0005]

However, as described above, in the method of simply determining the operating state by the average value of the whole, it is determined whether or not the filling amount of the filling machine is in a sufficiently controlled state. In many cases, it is not possible to notice the abnormality in the filling amount of the filling machine until an abnormality occurs in the selection result, and it is not possible to prevent the efficiency of the line from decreasing.

The present invention solves this problem, and can accurately determine whether or not the filling amount of the filling machine is in a sufficiently controlled state, and prevent the efficiency of the line from decreasing. It is intended to provide a weight sorting device.

[0007]

In order to achieve the above object, the weight sorting apparatus of the present invention has M (M is a plurality) filling heads for filling a container with an object to be weighed. A filling machine that carries out a container in which the objects to be weighed are sequentially filled by a plurality of filling heads, and a weighing conveyor that detects the weight of the object to be weighed in the container while conveying the container carried out from the filling machine, Weight storage means for storing the weight value of the object to be weighed on the weighing conveyor by a predetermined number N for each filling head in association with the filling head filled with the object, and the weight storage means. A first average calculating means for calculating a total average A of the weight values, and an average A of the weight values stored by the weight storage means for each filling head.
second average calculating means for calculating h _{1 to} Ah _M, and first standard deviation calculating means for calculating the standard deviation Sh _{1 to} Sh _M of each filling head of the weight value stored by the weight storing means. , The upper control limit UCLh and the upper control limit UCLh based on the total average A calculated by the first average calculation means and the standard deviations Sh _{1 to} Sh _{M for} each filling head calculated by the first standard deviation calculation means. Downward control limit LCL
The first control limit calculation means for calculating h and the weight value stored by the weight storage means are set in the order of storage and the number M of the filling heads is set as one set, and the average Ag ₁ to
Third average calculating means for calculating Ag _N , second standard deviation calculating means for calculating the standard deviations Sg _{1 to} Sg _N for each set, and total average calculated by the first average calculating means Second control limit calculation means for calculating the upper control limit UCLg and the lower control limit LCLg based on A and the standard deviations Sg _{1 to} Sg _{N for} each set calculated by the second standard deviation calculation means. And at least output means for displaying and outputting the calculation results of the respective calculation means.

[0008]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall configuration of a weight sorting device according to an embodiment.

In FIG. 1, a filling machine 20 has ten (M = 10) filling heads 21 _{1 to} 21 ₁₀ arranged in an annular shape.
While being orbited by a drive device (not shown), the objects W to be weighed are sequentially filled in the container 23 which is conveyed below by a conveyor 22 at the same speed. The filling machine 2
When the operation is started, 0 outputs a code signal indicating a filling head in which the container 23 at the head is filled with the object to be weighed to the control instruction device 30 described later.

The container 23 filled with the objects to be weighed is carried into the carrying section 25 of the weighing conveyor 24. The weighing device 26 supporting the transport unit 25 outputs a weighing signal corresponding to the total weight of the container 23 carried into the transport unit 25 and the object to be weighed. The weighing conveyor 24 is provided with a sensor 27 for detecting the loading of the container 23.

The weighing signal of the weighing device 26 and the output signal of the sensor 27 are input to a control instructing device 30 which will be described later, and the weight of the object to be weighed is detected.

After passing through the weighing conveyor 24, the container 23 is
It is carried into the distribution device 28 and distributed to different routes (not shown) according to the weight of the objects to be weighed in the container 23.

The control instructing device 30 is for controlling the entire weight sorting device, controls the entire device according to the sorting conditions and the like set by the operation of the operating section 31, and sets the set conditions and operation. Various information necessary for the operation of the apparatus such as the state is displayed and output to the display 32 or the printer 33.

The control instructing device 30 is composed of a microcomputer, and its functional blocks are shown in FIG. In FIG. 2, the weight detecting unit 35 detects the carry-in of the container 23 to the weighing conveyor 24 by the signal of the sensor 27 for a predetermined time, that is, after the container 23 is completely transferred to the transport unit 25 of the weighing conveyor 24. The weighing signal when the time required for the weighing signal of 26 to stabilize has been taken in as the total weight of the container 23 and the object to be weighed, and the weight of the container 23 stored in advance is subtracted from this total weight, Container 23
The weight of the object to be weighed inside is detected. The weight of the container 23 is set based on the weighing signal of the weighing device 26 when the empty container is loaded.

The weight value detected by the weight detecting means 35 is
It is output to the selection determination means 36 and the weight writing means 37.

The selection determination means 36 compares the weight value detected by the weight detection means 35 during the operation mode with a non-defective weight range preset by the operation section 31 and the like, and the weight detection means 35 detects the weight value. If the weight value is within the good product weight range, a good product signal is output to the distribution device 28, and if it exceeds the good product weight range, a defective signal is output to the distribution device 28.
The sorting device 28 sorts good products and defective products.

The weight writing means 37 receives the code signal from the filling machine 20 and stores the weight value of the object to be weighed detected by the weight detecting means 35 in association with the filling head filled with the object to be weighed. Write in 38. The weight writing means 3
Reference numeral 7 denotes a weight value N times the number M of filling heads (10 in this example) with respect to the number N (N is an arbitrary number from 1 to 32, for example) preset by the operation unit 31. The data is continuously stored in the memory 38.

The first average calculating means 40 calculates a total average A of all M · N weight values stored in the memory 38.

Further, the second average calculating means 41 is an average A of the weight values stored in the memory 38 for each filling head.
h _1, Ah _2, ..., and calculates the Ah _10, the first standard deviation calculation means 42, the standard deviation Sh ₁ for each filling head of the stored weight value in the memory _{38, Sh 2, ..., Sh} 10 And the average Sh thereof is calculated.

Further, the first control limit calculation means 43 has a total average A calculated by the first average calculation means 40 and a standard deviation Sh for each filling head calculated by the first standard deviation calculation means 42. Average S of ₁ , Sh ₂ , ..., Sh ₁₀
the upper control limit U for the filling head based on h and
Calculate CLh and the lower control limit LCLh.

On the other hand, the third averaging means 44 divides the weight value stored in the memory 38 into N groups in units of 10 (the number M of filling heads) in the order in which the weight values are stored, and for each group. mean Ag _1, Ag _2, ..., and calculates the Ah _N, the second standard deviation calculation unit 45, the standard deviation Sg _1, Sg ₂ of each of the respective groups, ..., Sg _N and the average Sg
To calculate.

The second control limit calculating means 46 is based on the total average A calculated by the first average calculating means 40 and the average value Sg of the standard deviations calculated by the second standard deviation calculating means 45. , Upper control limit U for group
Calculate CLg and down control limit LCLg.

The NG head detecting means 47 calculates the average value Ah ₁ , Ah ₂ , ..., Ah ₁₀ for each filling head calculated by the second average calculating means 41 by the first control limit calculating means 43. A filling head is detected that is out of the upper control limit UCLh and the lower control limit LCLh.

The determination means 49 determines that the average value calculated by the third average calculation means 44 during operation is between the upper control limit UCLg and the lower control limit LCLg calculated in advance by the second control limit calculation means 46. When it is determined that the average value calculated by the third average calculating means 44 exceeds between the upper control limit UCLg and the lower control limit LCLg, the notification means 50 determines whether a sound or a lamp is exceeded. This is notified by the light of.

The display control means 51 displays the selection condition, the selection result, etc. on the display 32. Also, the print control means 5
When the sampling operation is designated by the operation of the operation unit 31, the printer 2 prints the calculation result of each of the above-mentioned calculation means by the printer 33 and outputs it when the sampling operation is completed.

3 to 5 are flowcharts showing the processing procedure of the control instruction device 30. The operation of the weight selecting device will be described below with reference to this flowchart.

First, when the start of the sampling operation is designated by the operation of the operation unit 31, the filling machine 20 is instructed to start the filling (S1, S2).

When the filling machine 20 receives the instruction to start filling, it sequentially fills the containers 23 on the conveyor 22 with the objects to be weighed and controls the code signal Cn indicating the filling head 21n that first fills the objects to be weighed. Output to the indicating device 30.

Upon receiving the code signal Cn from the filling machine 20, the control instruction device 30 stores this and sets the variables P and Q to 1 (S3 to S5). Then, the weight value of the object to be weighed in the container 23 is detected based on the measured value after a lapse of a predetermined time after the leading container 23 filled with the object to be weighed is carried into the weighing conveyor 24, and the detected weight is detected. For example, the value is stored in the address (Cn, P) of the memory 38 in which the code Cn is upper and the lower is P, and the received code Cn is changed to the code of the next filling head (S6 to S9).

Hereinafter, each time the container 23 is loaded, the memory 3
8 addresses are updated, P reaches N (eg 15) and Q reaches M (10 in this example), ie 150
The above operation is repeated until the weight value of each piece is stored in the memory 38, and then the arithmetic processing of FIG. 4 is performed (S10).
S13).

That is, the total average A of all the weight values stored in the memory 38 is calculated, and subsequently, among the weight values stored in the memory 38, (1, 1), (1, 2), ... ,
For example, (1,15) has a common upper address of 15
Number of weight values, i.e., the average Ah ₁ ~Ah ₁₀ of each weight value of the objects to be weighed of the same filling head is filled by 15 times and the standard deviation Sh ₁ ~Sh ₁₀ is calculated for each filling head, standard deviation mean value sh of sh ₁ ~Sh ₁₀ is calculated (S21 to
S23).

Then, the upper limit control limit UCLh and the lower limit control limit LCLh for the filling head are calculated by the following equation (S24). UCLh = A + a · Sh LCLh = A−a · Sh

Next, among the weight values stored in the memory 38, ten weight values having common lower addresses, such as (1,1), (2,1), ..., (10,1). As one group, and the average value Ag _{1 to} Ag of the weight values for each group
₁₅ and the standard deviation Sg ₁ to SG ₁₅ is calculated, the average value Sg for the standard deviation is calculated (S25, S26).

Then, the upper control limit UCLg and the lower control limit LCLg for the group are calculated by the following equations (S27). UCLg = A + a · Sg LCLg = A−a · Sg

Here, the coefficient a is an average value control limit coefficient of 99% and is set to, for example, 2.58 / (number of filling heads) ^1/2 .

When the two types of upper limit control limit and lower limit control limit for the filling head and the group are calculated in this way, the control instructing device 30 causes the average value A for each filling head.
If any of h _{1 to} Ah ₁₀ exceeds the upper control limit UCLh and the lower control limit LCLh, they are detected, and the calculated values obtained by the above calculation are shown in FIG.
The printer 33 prints out as shown in (S2
8, S29).

In this printing, the filling heads whose average value exceeds the upper limit control limit UCLh and the lower limit control limit LCLh are marked with, for example, * as shown in FIG. The abnormal filling head can be identified immediately.

Looking at this print output, the operator sees the filling machine 20.
The operating state of can be accurately grasped. That is, the average and the variation of the filling amount for each filling head can be grasped, and the average and the variation of the filling amount for each group can be grasped with all the filling heads as one group. It is possible to accurately understand what range is being controlled with respect to the control limit.

Based on the printing result, each filling head is adjusted and the entire filling machine is adjusted and the sampling operation is performed again to bring the filling amount of the object to be weighed by the filling machine 20 into a sufficiently stable management state. To normal sorting operation (process S14 in FIG. 3).

As shown in FIG. 5, the processing during the sorting operation is as follows.
First, the variable Q is set to 1, the weight is detected when the loading of the container is detected, and the detected weight is stored in the memory 38 (S31 to S34).

Then, it is judged whether or not the detected weight is within the non-defective range, and if it is within the non-defective range, a non-defective signal is output to the distribution device 28 and the display 32 indicates the non-defective range. If it is not within the range, a defect signal is output to the distribution device 28 and a defect is displayed on the display 32 (S35 to S39).

Hereinafter, the same operation is repeated every time the container is loaded, but the variable Q reaches M, that is, every time 10 containers are loaded in this example, the average of the weights thereof is calculated,
It is determined whether or not the calculated average is between the upper control limit and the lower control limit for the group obtained during the sampling operation, and if it is within that range, the filling machine 2
It is assumed that the filling amount of 0 is maintained in a sufficiently controlled state, and if the filling amount is not within the range, the filling machine 20 is informed by sound or lamp light as a change that should be noted in management. (S40 to S44).

As described above, even during the normal sorting operation, it is constantly monitored whether or not the filling amount of the filling machine is in the control state, so that it is possible to take measures before a large number of defective products occur.
The efficiency of the line can be significantly improved.

In the above description, the sampling operation and the normal sorting operation are separated from each other, but the weight storage and each calculation during the sampling operation described above may be performed during the sorting operation.

In the above embodiment, each calculation result is printed out as a numerical value. However, the calculation result may be printed out as a graph or displayed on the screen of the display 32 as a graph.

[0046]

As described above, the weight sorting apparatus of the present invention is capable of determining the average and standard deviation of the filling amount of each filling head of the filling machine and the filling amount of each group including all filling heads. It is configured to calculate an average and a standard deviation, further calculate an upper control limit and a lower control limit, and output the display.

Therefore, the operator can accurately grasp the operating state of the filling machine 20 by confirming the display output. That is, the average and the variation of the filling amount for each filling head can be grasped, and the average and the variation of the filling amount for each group can be grasped, and those values can be compared with the upper control limit and the lower control limit. It is possible to accurately grasp whether it is controlled within the range, and based on that, adjust each filling head and the entire filling machine to make the filling amount of the object to be weighed by the filling machine sufficiently stable. be able to.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

FIG. 2 is a block diagram of a main part of one embodiment.

FIG. 3 is a flowchart showing a processing procedure of a main part of one embodiment.

FIG. 4 is a flowchart showing a processing procedure of a main part of one embodiment.

FIG. 5 is a flowchart showing a processing procedure of a main part of one embodiment.

FIG. 6 is a diagram showing an example of a printout of each calculation result obtained by sampling operation.

[Explanation of symbols]

20 Filling Machines 21 _{1 to} 21 ₁₀ Filling Head 22 Conveyor 23 Container 24 Measuring Conveyor 30 Control Instructing Device 31 Operating Unit 32 Display 33 Printer 35 Weight Detecting Means 40 First Averaging Calculating Means 41 Second Averaging Calculating Means 42 First Standard deviation calculation means 43 first control limit calculation means 44 third average calculation means 45 second standard deviation calculation means 46 second management limit calculation means 47 NG head detection means 49 determination means 50 notification means 52 print control means

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI G01G 19/62 G01G 19/62 (58) Fields investigated (Int.Cl. ⁷ , DB name) G01G 15/00 B07C 5/18 B65B 57/10 B67C 3/00 G01G 11/00 G01G 19/62

Claims (3)

(57) [Claims] 1. M pieces for filling a container with an object to be weighed (M
Has a plurality of filling heads and carries out the containers in which the objects to be weighed are sequentially filled by the plurality of filling heads, and the containers inside the containers while conveying the containers carried out from the filling machine. A weighing conveyor that detects the weight of the object to be weighed, and a weight storage that stores the weight value of the object to be weighed by the weighing conveyor in association with the filling head filled with the object to be weighed by a predetermined number N for each filling head. Means and a total average A of the weight values stored by the weight storage means.
And a second average calculating means for calculating the average Ah _{1 to} Ah _M of the weight values stored by the weight storing means for each filling head, and stored by the weight storing means. First standard deviation calculating means for calculating standard deviations Sh _{1 to} Sh _M of the respective filled heads of the obtained weight value, a total average A calculated by the first average calculating means, and the first standard deviation First control limit calculation means for calculating the upper control limit UCLh and the lower control limit LCLh based on the standard deviations Sh _{1 to} Sh _{M for} each filling head calculated by the calculation means, and stored by the weight storage means. A third average calculating means for calculating the average Ag _{1 to} Ag _N for each set, in which the number M of the filling heads is set as one set in the stored order of the stored weight values, and the standard deviation for each set. Sg ₁ ~ Sg Second standard deviation calculation means for calculating _N , total average A calculated by the first average calculation means, and standard deviations Sg _{1 to} Sg for each set calculated by the second standard deviation calculation means Upper control limit UCLg and lower control limit LC based on _N and
A weight sorting apparatus comprising: a second control limit calculation means for calculating Lg; and an output means for displaying and outputting a calculation result of each of the calculation means. 2. The upper control limit UC calculated by the first control limit calculation means is the average Ah _{1 to} Ah _M for each filling head calculated by the second average calculation means.
2. The weight sorter according to claim 1, further comprising: an NG head detection unit that detects a filling head that is out of a range between Lh and the lower control limit LCLh; and an NG head display unit that displays the filling head detected by the NG head detection unit. apparatus. 3. The averages Ag _{1 to} Ag _{N for} each set calculated by the third average calculating means are within the range of the upper control limit UCLg and the lower control limit LCLg calculated by the second control limit calculating means. The judging means for judging whether or not it exceeds, and the average Ag _{1 for} each group in response to the judgment result of the judging means.
~ Ag _N is the upper control limit UCLg and the lower control limit LCL
The weight sorting apparatus according to claim 1, further comprising a notification unit that notifies that the range of g has been exceeded.