JP6164921B2 - Weight sorter and filling weighing system - Google Patents

Description

  The present invention relates to a filling and weighing system that measures various items and fills them into a packaging bag and measures the weight of the filled items, and a weight sorter used therefor.

  As such a filling and weighing system, a combination weigher that combines and weighs articles such as confectionery, a packaging machine that packages the articles discharged from the combination weigher, and a non-defective product by measuring the weight of the packaged goods from the packaging machine, Some include a weight sorter that sorts out defective products (see, for example, Patent Document 1).

JP 2010-175514 A

  In a combination weigher, a target combination weight value and a higher upper limit weight value are generally set, and the weight values of articles supplied to a plurality of weighing hoppers are variously combined, and a combined total weight value (combination weight value) is obtained. The weighing hopper that is the combination closest to the target combination weight value is selected as the optimum combination among the combinations of the predetermined weight ranges defined by the target combination weight value (lower limit value) and the upper limit weight value.

  The articles discharged from the weighing hopper selected as the optimum combination are put into a packaging machine installed at the subsequent stage of the combination weigher, and are packed into a single packaged product by the packaging machine.

  The weight of the contents of the packaged product is specified on the label of the packaged product as a so-called nominal weight, but under the Japanese Measurement Law, the true weight value of the packaged product content is a weight that is smaller than the nominal weight. Should not be sold.

  For this reason, a weight sorter is installed after the packaging machine, the weight of the packaged product conveyed from the packaging machine is measured, and the weight of the packaged product content obtained by subtracting the average weight of the packaging material from the measured weight value. A packaged product whose value is smaller than the nominal weight is excluded as a defective product.

  In the combination weigher, as described above, based on the weight values of articles supplied to a plurality of weighing hoppers, which are a plurality of weighing instruments, the combination closest to the target combination weight value among the combinations in a predetermined weight range, Since the optimum combination is selected, the total weight value of the articles selected for the combination, that is, the weight value of the contents of the packaged goods, must be equal to or greater than the target combination weight value. Since there is a variation error in the measured weight value of the hopper, the true weight value of the commodity selected for the combination is distributed in a range of values smaller than the target combination weight value.

  In addition, since there is zero point drift due to the attachment of articles to each weighing hopper, or the load sensor that measures the load of each weighing hopper and the measurement circuit, for the plurality of weighing hoppers participating in the combination selection, The true weight value of the contents of the packaged goods selected in combination varies and drifts due to the characteristics of the plurality of weighing hoppers.

  Therefore, for products manufactured with a combination weigher, the target combination weight value cannot be manufactured and sold as the above nominal weight, and the target combination weight value is larger than the nominal weight in consideration of the weighing error of the combination weigher. To select the optimal combination. In order to check the true weight value of the product, a weight sorter is installed at the rear stage of the combination weigher.

  If the target combination weight value is not set appropriately, and is not too large compared to the nominal weight, and set to a value close to the nominal weight, the number of prepackages that are excluded as defective products by the weight sorter will increase. Become. Depending on the nature of the contents of a packaged product that has been excluded as a defective product, the contents cannot usually be used again, resulting in a loss of raw materials.

  On the other hand, if the target combination weight value is set to a value sufficiently larger than the nominal weight so that no defective product is generated, the content weight of the packaged product will be excessive for the manufacturer. If there is a raw material loss and the excessive amount is large, the price of the packaged product may have to be reflected.

  For this reason, the target combination weight value can be appropriately set, and the raw material loss can be suppressed to a range acceptable by the manufacturer, or the raw material loss can be reduced as much as possible to increase the raw material usage efficiency. desired.

  Such raw material loss is not limited to the case where articles are combined and weighed with a combination weigher and filled into a packaging bag, but when a packaging container or the like is filled with a predetermined amount of goods such as powder or liquid. Is a similar problem.

  This invention is made | formed in view of the above points, Comprising: It aims at suppressing the raw material loss and improving the use efficiency of a raw material.

  In order to achieve the above object, the present invention is configured as follows.

(1) weight sorter of the invention, the filling weight of the article to the container is disposed downstream of the auger quantitative weight filling apparatus for filling such that the target fill Weight, the article is filled A weight sorter for measuring the weight of a filled container,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Depending on the rate of occurrence of defective products to be set on the setting means, a determining means for the target fill weight of the quantitative weight filling apparatus of the auger, is determined as a management target weight value,
Calculating a deviation between an average weight value of the contents of the filled container and the management target weight value, and including a control means for outputting the calculated deviation to the auger-type fixed weight filling apparatus;
The auger-type fixed weight filling apparatus controls increase / decrease of the target filling weight so as to cancel the deviation.

  A container means a container and includes not only bottles and cans but also bags.

  A filled container refers to a container filled with an article, which may be sealed and made into a product, or an unsealed container that is filled with an article but is not equipped with a lid or the like. There may be.

  The nominal weight for a filled container refers to the nominal weight for the contents of the filled container and refers to the nominal weight when the filled container is sold as a commercial product.

According to the weight sorter of the present invention, the target filling amount of the filling device is determined as the management target weight value by setting the allowable rate of defective products, and accordingly, the target filling amount of the filling device is set as the target filling amount. By controlling so as to be the management target weight value, the generation rate of defective products is suppressed to an allowable generation rate. Thereby, the loss of the raw material article as a defective product can be suppressed to an acceptable loss amount.
(2) The weight sorter of the present invention is disposed at the subsequent stage of an auger type quantitative volume filling device that fills the container so that the filling volume of the article into the target filling volume corresponds to the target filling weight, A weight sorter for measuring the weight of a filled container filled with the article,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Determining means for determining the target filling weight of the auger type quantitative volume filling device as a management target weight value in accordance with the occurrence rate of defective products set in the setting means;
Calculating a deviation between an average weight value of the contents of the filled container and the management target weight value, and a control means for outputting the calculated deviation to the auger-type fixed volume filling device;
The auger type fixed volume filling device controls the increase or decrease of the target filling weight so as to cancel the deviation.
(3) In the weight sorter of the present invention, the combination weight obtained by combining the weights of the articles based on the weights of the articles weighed by the plurality of weighing hoppers to which the articles are supplied is a predetermined lower limit value. A combination weighing scale that selects a combination of the weighing hoppers close to the target combined weight and discharges articles from each selected weighing hopper, and a packaging machine that fills containers discharged from the combination weighing scale A weight sorter for measuring the weight of a filled container filled with the article, which is disposed in a subsequent stage of the filling device,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Determining means for determining the target combination weight of the combination weigher as a management target weight value according to the occurrence rate of defective products set in the setting means;
A control means for calculating a deviation between an average weight value of the contents of the filled container and the management target weight value, and outputting the calculated deviation to the combination weigher;
The combination weigher controls increase / decrease of the target combination weight so as to cancel out the deviation.

( 4 ) The weight sorter of the present invention is arranged at the subsequent stage of the filling device for filling the container so that the amount of the article filled in the target filling amount, and measures the weight of the filled container filled with the article. A weight sorter that performs
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Sum usage, and usage exceeding the nominal weight of the article is the contents of the pre-filled container is judged as good products are the contents of the pre-filled container is determined to be defective the article Determining means for determining the target filling amount of the filling device as a management target weight value so as to suppress the total used amount ,
The determining means determines the management target weight value based on the reference weight value, a weight distribution of the contents of the filled container, and the nominal weight, and the determining means includes: When the weight distribution of the contents of the filled container is a normal distribution, and the management target weight value is variously changed, the average weight value of the contents of the filled container is the changed management target weight. The management target weight value is determined so that the total usage calculated when it is assumed to be controlled to match the value is minimized,
The filling device controls the target filling amount to the management target weight value .

Determining means, and the amount of the article is the contents of the pre-filled container is determined to be defective, the article is the contents of the pre-filled container is determined to be nondefective, the sum of the amount in excess of the nominal weight The management target weight value is determined so as to suppress the total usage amount.

In the determining means, when the management target weight value is changed, the number of non-defective products is determined based on the reference weight value for determining the quality of the weight value of the filled container contents and the weight distribution of the filled container contents. And the number of defective products can be calculated, and the amount of non-defective items used exceeding the nominal weight and the amount of defective items used can be calculated. .
According to the weight sorter of the present invention, the amount of the article is the contents of the pre-filled container to be sorted as a defective, i.e., the loss of raw material article as a defective product, the pre-filled container is determined to be good Filling device so as to suppress the total amount of use exceeding the nominal weight of the article that is the content, that is, the amount of excess article usage exceeding the nominal weight that would result in loss of the raw material article for the manufacturer. Since the target filling amount is determined as the management target weight value, the target filling amount of the filling device is controlled so as to become the management target weight value, thereby suppressing the loss amount of the raw material article and the usage efficiency of the raw material article. Can be improved.

( 5 ) In the embodiment of (1) or (2) , the determining means is based on the reference weight value, the amount of variation in the measured weight value of the filled container, and the occurrence rate of the defective product. The management target weight value may be determined.

  According to this embodiment, the reference weight value, which is the boundary weight value for determining the quality of the weight value of the contents of the filled container, is taken into account the variation amount of the measured weight value and the occurrence rate of the defective product set. An appropriate management target weight value can be determined by adding the values.

(6) Filling weighing system of the present invention, the filling weight of the article to the container, and quantifying the weight filling device auger filling so that the target filling Weight, subsequent quantification weight filling apparatus of the auger A weighing and weighing system comprising: a weight sorter configured to measure the weight of a filled container filled with the article,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Depending on the rate of occurrence of defective products to be set on the setting means, a determining means for the target fill weight of the quantitative weight filling apparatus of the auger, is determined as a management target weight value,
The deviation between the average weight value of the contents of the filled container and the management target weight value is calculated, and the target filling weight of the auger type quantitative weight filling apparatus is controlled to increase or decrease so as to cancel the deviation. Control means.

  The discrimination means is preferably built in a weight sorter, and the control means is preferably built in a filling device.

According to the filling and weighing system of the present invention, by setting an acceptable rate of defective products, the target filling amount of the filling device is determined as the management target weight value accordingly, and the target filling amount of the filling device is Since the control is performed so as to achieve the management target weight value, the generation rate of defective products is suppressed to an allowable generation rate. Thereby, the loss of the raw material article as a defective product can be suppressed to an acceptable loss amount.
(7) The filling and weighing system of the present invention includes an auger-type fixed volume filling device that fills a container so that a filling volume amount of an article becomes a target filling volume amount corresponding to a target filling weight; A filling and weighing system, comprising a weight sorter that is disposed in a subsequent stage of a fixed volume filling device and measures a weight of a filled container filled with the article,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Determining means for determining the target filling weight of the auger type quantitative volume filling device as a management target weight value in accordance with the occurrence rate of defective products set in the setting means;
The deviation between the average weight value of the contents of the filled container and the management target weight value is calculated, and the target filling weight of the auger type quantitative volume filling device is controlled to increase or decrease so as to cancel the deviation. Control means.
(8) In the filling and weighing system of the present invention, the combination weight obtained by combining the weights of the articles based on the weights of the articles weighed by the plurality of weighing hoppers to which the articles are supplied is a predetermined value having the target combination weight as a lower limit value. A combination weighing scale that selects a combination of the weighing hoppers close to the target combined weight and discharges articles from each selected weighing hopper, and a packaging machine that fills containers discharged from the combination weighing scale A filling and weighing system comprising: a filling device comprising: a weight sorter disposed at a subsequent stage of the filling device and measuring a weight of a filled container filled with the article,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Determining means for determining the target combination weight of the combination weigher as a management target weight value according to the occurrence rate of defective products set in the setting means;
And a control unit that calculates a deviation between the average weight value of the contents of the filled container and the management target weight value, and controls the increase / decrease of the target combination weight so as to cancel the deviation.

( 9 ) In the filling and weighing system of the present invention, a filling device for filling the container so that the amount of the article to be filled becomes the target filling amount, and a filled state in which the article is filled, which is arranged at a subsequent stage of the filling device. A filling weighing system comprising a weight sorter for measuring the weight of a container,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Sum usage, and usage exceeding the nominal weight of the article is the contents of the pre-filled container is judged as good products are the contents of the pre-filled container is determined to be defective the article Determining means for determining the target filling amount of the filling device as a management target weight value so as to suppress the total used amount ;
Control means for controlling the target filling amount of the filling device to the management target weight value ,
The determining means determines the management target weight value based on the reference weight value, a weight distribution of the contents of the filled container, and the nominal weight, and the determining means includes: When the weight distribution of the contents of the filled container is a normal distribution, and the management target weight value is variously changed, the average weight value of the contents of the filled container is the changed management target weight. The management target weight value is determined so that the total use amount calculated when it is assumed that the control is performed so as to match the value is minimized.

According to the filling weighing system of the present invention, the amount of the article is the contents of the pre-filled container to be sorted as a defective, i.e., the loss of raw material article as a defective, the filled container is discriminated as good products In order to suppress the total amount of usage exceeding the nominal weight of the article that is the content of the product, i.e., the amount of excess article usage exceeding the nominal weight that results in the loss of the raw material article to the manufacturer, The target filling amount of the filling device is determined as the management target weight value, and the target filling amount of the filling device is controlled so as to become the management target weight value. Can be improved.

  According to the present invention, by setting an acceptable rate of defective products, the target filling amount of the filling device is determined as the management target weight value accordingly, and the filling amount becomes the management target weight value. Since the control is performed, the loss amount of the raw material article as a defective product can be suppressed to an allowable loss amount.

Further, according to the present invention, the loss of raw material article as a defective, the amount of sum of the sum of the amount of excess articles exceeding the nominal weight of a good product, to suppress, filling device Is determined as the management target weight value and is controlled so that the filling amount becomes the management target weight value. Therefore, the loss of the raw material article can be suppressed and the usage efficiency of the raw material article can be improved.

1 is a schematic configuration diagram of a filling and weighing system according to an embodiment of the present invention. It is a schematic plan view which shows the branch type conveying machine (channelizer) of FIG. It is a figure which shows the weight distribution of the content of the filled container measured with a weight sorter. It is a figure for demonstrating the management target weight value Wqo in the weight distribution of FIG. It is a flowchart for demonstrating the operation | movement in the 1st control period of a weight sorter. It is a flowchart for demonstrating the operation | movement in the control period after the 2nd time of a weight sorter. It is a figure which shows the relationship of each weight level of the nominal weight Qn at the time of setting to selection margin width K = 2.88 (sigma), the reference | standard weight value Qt, and the average weight value of the content of the filled container. It is a figure which shows the relationship of each weight level of the nominal weight Qn at the time of setting to the selection margin width K = 2.65 (sigma), the reference | standard weight value Qt, and the average weight value of the content of the filled container. It is a figure which shows the relationship of each weight level of the nominal weight Qn at the time of setting to sorting margin width K = 1.88 (sigma), the reference | standard weight value Qt, and the average weight value of the content of the filled container. It is a schematic block diagram of the filling measurement system which concerns on other embodiment of this invention. It is a schematic block diagram of the filling measurement system which concerns on other embodiment of this invention. It is a schematic plan view which shows the distribution apparatus (flipper) of FIG. It is a figure which shows the weight distribution of the content of the packaging container measured with the weight sorter of FIG. It is a figure which shows the change of distribution of the measured weight value Wx according to the change of the management target weight value Wqo. It is a figure which shows the example of each frequency distribution table at the time of changing management target weight value Wqo.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a filling and weighing system according to an embodiment of the present invention.

  The system of this embodiment includes a container supply device 2 that supplies a packaging container 1, a fixed weight filling machine 4 that fills the supplied container 1 with a certain weight of, for example, a granular article 3, and an article 3. And a weight sorter 5 that measures the weight of the container 1 filled with, sorts out defective products with insufficient weight and excludes them from the main transport line.

  The fixed weight filling machine 4 as a filling device is an auger type filling machine, and the auger (longitudinal screw) 9 is rotated by a servo motor 10 by a predetermined number of revolutions to measure the article 3 in the storage hopper 6. Drop supplied to the hopper 7. A pulse generator 11 attached to the rotation shaft of the servo motor 10 generates a pulse corresponding to the rotation of the servo motor 10. The control device 12 of the fixed weight filling machine 4 is supplied to the weighing hopper 7 based on the load signal from the load cell 8 corresponding to the weight of the article 3 supplied to the weighing hopper 7 and the pulse from the pulse generator 11. The drive of the servo motor 10 is controlled so that the weight of the article 3 to be obtained becomes the target filling weight.

  The weighing hopper 7 opens the pair of discharge gates 7a at a required timing, and fills the container 1 with the supplied constant weight article 3.

  The container 1 filled with the article 3 (hereinafter also referred to as “filled container”) is conveyed to the weight sorter 5. The weight sorter 5 includes a weighing conveyor 14 supported by the load cell 13 and a control device 15 to which a load signal from the load cell 13 is given.

  The control device 15 of the weight sorter 5 is set with a reference weight value Qt, which will be described later, for determining defective products relative to the content weight of the filled container 1a, and is based on the measured weight value of the filled container 1a measured by the weighing conveyor 14. If the content weight value of the filled container 1a is less than the reference weight value Qt, it is determined as a defective product. The control device 15 of the weight sorter 5 and the control device 12 of the fixed weight filling machine 4 are connected via a communication line.

  At the subsequent stage of the weight sorter 5, a branch type transporter (channelizer) 16 which is a kind of sorting device is provided, and as shown in the schematic plan view of FIG. 1a is removed from the main transfer line 17 of the conveyor to the branch path 17a.

  The filled container 1a selected as a non-defective product is sealed with a lid attached during the transfer of the main transfer line 17 to be a packaged product.

  In such a filling and weighing system, if the true weight value of the contents of the filled container 1a filled with the article 3 by the quantitative weight filling machine 4 is smaller than the nominal weight Qn, it cannot be made into a product.

  In the fixed weight filling machine 4, a constant weight of the article 3 is filled into the container 1 via the weighing hopper 7. However, since the article 3 is dropped and supplied to the weighing hopper 7, the weighing hopper 7 has a large noise due to an impact. If it occurs and the filling cycle time is short, the supply amount of the article 3 being filled cannot be reduced, and the article 3 supplied to the weighing hopper 7, and thus the true weight of the article 3 filled in the container 1. The variation of is large.

  Also, the weighing hopper 7 that supplies the article 3 to the container 1 adheres to the article 3 to be filled and the zero point drifts. However, when the filling cycle time is short, there is no timing for measuring the zero point weight and adjusting the zero point. The true weight of the article 3 filled in the container 1 drifts.

  Therefore, as in the case of the combination weigher described above, the target filling weight of the fixed weight filling machine 4 cannot be manufactured and sold with the nominal filling weight as the nominal weight. In consideration of error, it is set to a value larger than the nominal weight value. If the target filling weight is not properly set and is set to a value close to the nominal weight, the number of filled containers 1a that are excluded as defective products by the weight sorter 5 increases, resulting in a raw material loss. On the contrary, if the target filling weight is set to a value sufficiently larger than the nominal weight value, the content weight of the filled container 1a is excessively larger than the nominal weight, resulting in a raw material loss for the manufacturer.

  Therefore, in this embodiment, by setting the occurrence rate of defective products acceptable to the manufacturer in the weight sorter 5, the fixed weight filling is performed so that the occurrence rate of defective products is suppressed to the set occurrence rate. The target filling weight of the machine 4 is controlled.

  Alternatively, while reducing the number of filled containers 1a that are excluded as defective products by the weight sorter 5 and reducing the raw material loss, the excessive weight larger than the nominal weight of the filled containers 1a is reduced. In order to reduce the raw material loss for the manufacturer, the target filling weight of the fixed weight filling machine 4 is controlled to improve the use efficiency of the raw material.

  First, the target filling weight of the quantitative weight filling machine 4 is controlled so that the occurrence rate of defective products is suppressed to the set occurrence rate by setting the acceptable rate of defective products in the weight sorter 5. The case where it does is demonstrated.

  That is, in this embodiment, the operator sets an allowable defective product rate as an allowable defective product rate R by operating a setting display unit (not shown) of the control device 15 of the weight sorter 5. Thereby, the control device 15 determines the management target weight value Wqo according to the allowable defective product rate R as described later, and calculates the average value of the measured content weight of the filled container 1a and the management target weight value Wqo. The deviation is calculated and transmitted to the control device 12 of the fixed weight filling machine 4. The control device 12 fills the container 1 with the article 3 by increasing / decreasing the target filling weight so as to cancel the deviation. Therefore, filling the article 3 by the quantitative weight filling machine 4 so that the weight value of the contents of the filled container 1a measured by the weight sorter 5 becomes the management target weight value Wqo corresponding to the allowable defective product rate R. The amount will be controlled.

  The increase / decrease control of the target filling weight is performed based on the content weight Wx of the filled container 1a in a predetermined number unit measured by the weight sorter 5 for every predetermined control period. The predetermined number P of the filled containers 1a manufactured during the predetermined control period is called a control unit number, and is set by operating the setting display unit of the control device 15 of the weight sorter 5 before starting the operation. To do.

  The value of P is preferably large so that the tendency of the weight of the contents of the filled container 1a can be expressed as accurately as possible, but conversely, it is controlled without delay to the weight change of the contents of the filled container 1a. A small value is appropriate in order to follow. For this reason, in consideration of the properties of the production line and the article 3 to be filled, the control period is set to, for example, 30 minutes, and the number of filled containers 1a to be manufactured in the meantime, for example, about 100 to 500 is set. The

  The control device 15 of the weight sorter 5 is set with a reference weight value Qt that is a reference value (boundary weight value) for defective product sorting. This reference weight value Qt is larger than the nominal weight Qn. In the weight sorter 5, the filled container 1a whose content weight of the filled container 1a is less than the reference weight value Qt is excluded as a defective product.

  The probability of occurrence of a filled container 1a that is excluded as a defective product, that is, the occurrence rate of the defective product depends on the weight distribution probability of the manufactured filled container 1a and the reference weight value Qt.

  Even if a predetermined target filling weight is set in the fixed weight filling machine 4 and the container 3 is filled with the article 3, the weight of the article 3 filled in the container 1 varies, so the true weight of the filled container 1a varies. . The variation in the weight of the container 1 is also included in the variation in the true weight of the filled container 1a.

  Furthermore, since the weight sorter 5 also has a variation error in the weight measurement value, the weight value of the filled container 1a measured by the weight sorter 5 is the variation in the weight of the contents of the filled container 1a and the weight of the container 1. 3 and a variation of the weight measurement value of the weight sorter 5, for example, a normal distribution as shown in FIG.

When the filled container 1a in which the weight measurement values are normally distributed as described above is sorted based on the reference weight value Qt, as shown in FIG. 3, the reference weight value Qt is the weight sorter 5 with respect to the nominal weight Qn. Qt = Qn + Wsc (1) in consideration of the shift weight Wsc considering the weighing error of
And decide.

The shift weight Wsc in consideration of the weighing error of the weight sorter 5 is the weighing accuracy Ew indicating the variation error of the measurement value of the weight sorter 5, the zero point drift amount in use, and the environmental conditions where the weight sorter 5 is installed. Wsc = Ew + Df (2) using the accuracy margin expected value Df taking into consideration the use conditions such as the implementation status of zero and zero correction
And decide.

  The weighing accuracy Ew representing the variation error is defined as a measurement accuracy Ew (Ew = 3 sigma value), which is a 3 sigma value representing a variation error that occurs when the same heavy article is measured a plurality of times by the weight sorter 5 alone. Alternatively, the weighing accuracy Ew may be defined as a 2 sigma value.

  The value of the weighing accuracy Ew is preferably a fixed value set in the control device 15 of the weight sorter 5 and stored in its memory. Since the measurement accuracy Ew varies depending on the measurement conditions, that is, the type of product to be manufactured, the conveyance speed, and the like, the measurement conditions Wcn (n = 1, 2,...) Corresponding to these requirements are specified in advance. Then, in the adjustment stage before the start of operation, the weighing accuracy Ew1, Ew2,... Showing the variation error for each weighing condition Wc1, Wc2,... Is obtained and controlled as a weighing accuracy table for each weighing condition number. Store in the memory of the device 15. When the measurement condition is designated or set in the control device 15 by the value of the number n or the like during operation, the measurement accuracy Ew corresponding to the measurement condition is read from the measurement accuracy table.

  Since the value of the accuracy margin expected value Df also varies depending on the use conditions such as the environmental conditions where the weight sorter 5 is installed and the state of zero correction as described above, the initial value is “0” but not a fixed value. It is preferable that the user can set an arbitrary value.

  The value of the shift weight Wsc determined in this way can be displayed on the setting display section of the control device 15 of the weight sorter 5.

  The filled container 1a carried into the weight sorter 5 has a reference weight value Qt as a boundary based on the content weight Wx obtained by subtracting the average weight value Wpa of the container 1 from the weight value Wx ′ measured by the weight sorter 5. Sorted into good and defective products by weight. The filled container 1a selected as a defective product having the content weight Wx less than the reference weight value Qt is branched and conveyed from the main conveyance line 17 as described above, and is not a packaged product.

  In the control device 15 of the weight sorter 5, the management target weight value Wqo is determined as follows based on the set allowable defective product rate R.

  As described above, the weight value of the filled container 1a measured by the weight sorter 5 includes the variation in the weight of the contents of the filled container 1a, the variation in the weight of the container 1, and the weight measurement of the weight sorter 5. When the variation is added, it is assumed that the variation is expressed in a state expressed by a probability density function corresponding to a normal distribution as shown in FIG. 3, and the standard deviation of the variation amount is Ws.

When the average weight value Wxa of the content weight of the filled container 1a is controlled to satisfy, for example, the following expression (3) by controlling the filling weight of the article 3 by the fixed weight filling machine 4:
Wxa-3 · Ws = Qt (3)
Based on the probability density function of the standard normal distribution, since the value of Z = 3 sigma is 0.4987, the reference weight value is about 0.13% (= 0.5-0.4987) of the filled container 1a. There will be a filled container 1a with a content weight less than Qt, and the filled container 1a will be sorted out with a probability of 0.13%.

  It is assumed that a sigma value is set as the selection margin width K from the reference weight value Qt to the management target weight value Wqo, and the selection margin width K = 3 sigma.

The management target weight value Wqo is based on the reference weight value Qt and the standard deviation Ws. Wqo = Qt + 3 · Ws (4)
It is expressed. If the average weight value Wxa is controlled to coincide with the management target weight value Wqo, defective product selection with a probability of 0.13% is achieved.

When the selection margin K is set as the sigma value, the management target weight value Wqo is
Wqo = Qt + K · Ws (5)
It is expressed.

  In order to obtain the standard deviation value Ws, the fixed weight filling machine 4 and the weight sorter 5 are operated under the same conditions as in the operation operation in the adjustment stage before the start of the operation operation. That is, the fixed weight filling machine 4 sets a predetermined target filling weight of the filled container 1a to be manufactured during the operation operation, and repeatedly fills the container 1 with the article 3 as a test in the adjustment stage, whereby a plurality of filled containers are filled. 1a is manufactured. The weight of the manufactured filled container 1a is measured by the weight sorter 5 under the conditions during operation, and the control device 15 calculates the standard deviation value Ws from the measured weight measurement value.

  When the sorting margin K is set as a sigma value in the control device 15 of the weight sorter 5, the management target weight value is calculated according to the above equation (5) using the calculated standard deviation value Ws and the set sorting margin K. Wqo can be determined. The reference weight value Qt is calculated according to the above equations (1) and (2) by setting the nominal weight Qn.

  In this embodiment, the sorting margin width K is determined not by setting the sorting margin width K in the control device 15 of the weight sorter 5, but by setting the allowable defective product occurrence rate. A weight value Wqo is determined.

  That is, the allowable defective product rate R is set in the control device 15 as the allowable defective product rate.

  In a control calculation unit (not shown) of the control device 15 of the weight sorter 5, a standard normal distribution table is stored in advance in a built-in memory, and by setting an allowable defective product rate R, as follows, The selection margin K (sigma value) and the management target weight value Wqo are determined.

  That is, when the allowable defective product rate R is set to R = 1 (%), for example, in the standard normal distribution table, 0.5- (R / 100) = 0.5-0.01 = 0.49 is the most. Find a close value.

Since the value of Z = 2.33 sigma is 0.4901, the management target weight value Wqo is set as shown in FIG.
Wqo = Z + Qt = 2.33 · Ws + Qt (6)
And decide.

  When there is no Z value that exactly matches the set allowable defective product rate R, the closest Z value may be used, or may be obtained by an interpolation method.

Instead of the allowable defective product rate R, the number of defectives relative to the P control unit number may be used. In that case, the allowable defective product rate R is as follows.
R = (Ru / P) · 100 (%).

  The standard deviation Ws for calculating the management target weight value Wqo may be determined in the adjustment stage test before the start of operation as described above and set as a fixed value, but is determined as follows. Also good.

  That is, at the start of operation, a large temporary management target weight value Wqo is set so that the filled container 1a is not easily sorted as a defective product, and P control units are set as the first control period. The standard deviation Ws is calculated from the weight measurement value of the filled container 1a, and the management target weight value Wqo is determined by using the above equation (5) by the calculated standard deviation Ws. As will be described, the filling target weight may be controlled.

  And after the second control period, the standard deviation Ws obtained in the first control period may be used continuously, but for each control period, the weight measurement value from the start of operation until now, Alternatively, the next standard target weight value Wqo may be updated by calculating the latest standard deviation Ws based on the weight measurement value for each control period.

  Next, increase / decrease control of the target filling weight of the fixed weight filling machine 4 will be described.

  The filling weight of the quantitative weight filling machine 4 is controlled on the basis of the average value of P content weight values of the filled container 1a measured by the weight sorter 5 and the management target weight value Wqo.

  Here, a case where the standard deviation Ws is obtained after the operation operation is started will be described.

  At the start of operation, the setting display unit of the control device 15 of the weight sorter 5 sets and inputs the control unit number P, the nominal weight Qn, the shift weight Wsc, and the allowable defective product rate R (%) corresponding to the control period. . However, the accuracy margin expected value Df is set in advance, and the weighing accuracy Ew is read by setting the weighing condition Wcn, and the shift weight Wsc is set by the above equation (2).

  Thereby, the reference weight value Qt is calculated and set. At the start of operation, a target filling weight is set in the control device 12 of the fixed weight filling machine 4 so that the content weight of the filled container 1a has a sufficient margin compared to the reference weight value Qt.

  The weight Wx ′ of the filled container 1a is measured by the weight sorter 5, the preset average weight value Wpa of the container 1 is subtracted, and the weight Wx of the filled container 1a is used as a weight measurement value of the weight sorter 5. (= Wx′−Wpa) is calculated.

  In addition, since the trouble accompanying filling of the articles | goods 3 may generate | occur | produce on the fixed weight filling machine 4 side, in order to determine whether it is the weight as an appropriate filled container 1a, lower limit value We1 and upper limit If the value We2 is set in advance and the measured weight does not fall within this appropriate weight range, it is excluded from the control calculation target.

After measuring the weight of the P filled containers 1a after the start of the operation operation, the standard deviation Ws is calculated based on the weight measurement value, the control target weight value Wqo is determined as described above, and the control operation is started.
Each time the content weight Wx of the P filled containers 1a is measured, the latest average weight value Wxa and the latest standard deviation Ws are obtained, and the comparison result between the average weight value Wxa and the management target weight value Wqo, for example, the difference wdx Is calculated as follows.

Wxa-Wqo = wdx
The absolute value and sign of the difference wdx are transmitted to the control device 12 of the quantitative weight filling machine 4 as an operation amount for the quantitative weight filling machine 4 to be controlled. As a comparison result between the average weight value Wxa and the management target weight value Wqo, a ratio value may be transmitted by obtaining a ratio between the average weight value Wxa and the management target weight value Wqo. At the same time, P average weight values Wxa are also transmitted.

  If there are S filled containers 1a in the transport path between the fixed weight filler 4 and the weight sorter 5, the weight sorter 5 transmits the operation amount, and the fixed weight filler 4 side Since the filled containers 1a appearing as a result of the control based on the operation amount are after S pieces have passed, the collection of the weights of the P filled containers 1a for the next control is S filling The next P weight measurement values are collected by excluding the measurement value of the content weight of the finished container 1a. The value of S is set as a dead number in the control device 15 of the weight sorter 5 before the start of operation.

  Since the average value Wxa of the content weight of the filled container 1a measured by the weight sorter 5 is always controlled to be near the management target weight value Wqo, the defective product rate becomes a value close to the allowable defective product rate R.

  Note that the S dead number is smaller and less affected than the P control unit number, and therefore the weight measurement values of (P + S) filled containers 1a are collected in the second and subsequent control periods. You may make it do.

Since the fixed weight filling machine 4 performs the filling by setting the target filling weight value Wt, the target filling weight value Wt is determined by the absolute value and sign of the difference wdx received from the weight sorter 5.
Wt-wdx → Wt (7)
And fix it. That is, the target filling weight is corrected so as to cancel out the deviation.

  Thereby, the average value Wxa of the content weight of the filled container 1a measured by the weight sorter 5 is controlled to become the management target weight value Wqo, and the defective product sorted by the weight sorter 5 is set. The value is close to the allowable defective product rate.

  FIG. 5 is a flowchart for explaining the above operation of the weight sorter 5.

  First, it is determined whether or not the first end flag F1 indicating that the first control period after the start of the operation operation has ended is set to “1” (step n1). When the first control period has not expired, the control calculation is started. In this tabulation calculation, it is determined whether or not the weight measurement value Wx ′ of the filled container 1a has been read (step n2), and if not, the process ends.

  When it is determined that the weight measurement value Wx ′ has been read in step n2, the content weight Wx of the filled container 1a is calculated by subtracting the average weight Wpa of the container 1 from the weight measurement value Wx ′ (step n3). It is determined whether or not the weight Wx is an appropriate weight range as a control calculation target, that is, a weight range defined by the lower limit value We1 and the upper limit value We2 (step n4). ,finish.

  When the content weight Wx is in an appropriate weight range in step n4, “1” is added to the number counter Cx that counts the number of the filled containers 1a (step n5), and the average value or standard value of the content weight Wx is added. Aggregation processing for calculating the deviation is performed. Specifically, the content weight Wx is integrated (step n6), and the square of the content weight Wx is integrated (step n7).

  Next, it is determined whether or not the count value of the number counter Cx for counting the number of filled containers 1a reaches the control unit number P (step n8). When the number becomes P, the average value Wxa of the content weight Wx of the filled container 1a is calculated (step n9), and further, the standard deviation Ws is calculated (step n10), and the totals calculated in the above steps n6 and n7. The value is reset (step n11).

  Next, the Z value corresponding to the set allowable defect rate R is calculated based on the standard normal distribution table (step n12), and the management target weight value Wqo is calculated based on the above equation (6). (Step n13). The reference weight value Qt in equation (6) is calculated based on the above equations (1) and (2).

  Next, the count value of the number counter Cx is reset to “0” (step n14), and the first end flag F1 indicating that the first control period has ended is set to “1” and the process ends (step S14). n15).

  When the first end flag F1 is set to “1” in the above step n1, the first control period has ended, so the process proceeds to step n16 in FIG. 6, and the first and subsequent control periods are set. It is determined whether or not the second end flag F2 indicating the end is set to “1”. If the second end flag F2 is set, the control period is ended, and the process proceeds to step n21. In step n21, it is determined whether or not the weight measurement value Wx ′ of the filled container 1a has been read. If it has not been read, the process ends. If the weight measurement value Wx ′ has been read, the measured number of filled containers 1a. 1 is added to the count value of the number counter Cx (step n22), and it is determined whether or not the count value of the number counter Cx has become an insensitive number (step n23). If not, the process ends. If the number reaches S, the count value of the number counter is reset to “0” (step n24), the second end flag F2 is reset to “0”, and the process returns to step n16. (Step n25).

  In this way, the S filled containers 1a after the end of the control period are excluded from the target of the control calculation.

  When the second end flag F2 is not set to “1” at step n16, that is, when it is reset to “0”, the control period has not ended. The control calculation processing for the control period is performed. This aggregation calculation process is the same as the process from step n2 to step n14 in FIG.

  Next, in step n18, the average value Wxa of the content weight of the filled container 1a based on the weight measurement value acquired in the current control period, and calculated in the previous control period and used for the control of the current control period. A difference wdx from the management target weight value Wqo is calculated, and the absolute value and sign of the calculated difference wdx are transmitted to the quantitative weight filling machine 4 (step n19), and a second end flag indicating that the control period has ended. F2 is set to “1” and the process ends (step n20).

  In the fixed weight filling machine 4, the target filling weight is controlled so that the difference wdx is eliminated, whereby the occurrence rate of the filled container 1a sorted as a defective product by the weight sorting machine 5 is set as an allowable defective product set. It becomes a value close to the rate R, and the loss of the raw material article as a defective product can be suppressed to an acceptable loss amount.

  As described above, the operator determines the management target weight value Wqo according to the allowable defective product rate R by setting the allowable defective product rate R in the control device 15 of the weight sorter 5, and measured filling. The deviation between the content weight of the finished container 1a and the management target weight value Wqo is calculated and transmitted to the control device 12 of the fixed weight filling machine 4, and the control device 12 controls the target filling weight so as to cancel the deviation. By doing so, the loss of the raw material article as a defective product can be suppressed to an acceptable loss amount.

  Further, since the average value Wxa of the content weight of the filled container 1a measured by the weight sorter 5 is controlled to be near the management target weight value Wqo, the content weight of the filled container 1a is set to the reference weight value Qt. It won't be too big. Thereby, the loss of the raw material by the excessive amount exceeding the nominal weight Qn of the contents of the filled container 1a can be prevented.

  In the above, although the allowable defective product rate R is set and the management target weight value Wqo is determined accordingly, in this embodiment, the number of filled containers 1a excluded as defective products by the weight sorter 5 is further determined. To reduce the loss of raw material and reduce the excess of the content weight of the filled container 1a more than the nominal weight to reduce the raw material loss for the manufacturer and improve the use efficiency of the raw material it can.

  That is, in this embodiment, when a predetermined number of filled containers 1a are manufactured based on the weight distribution of the filled containers 1a, the reference weight value Qt, and the nominal weight value Qn, the use efficiency of the raw material is maximized. The management target weight value Wqo can be determined.

  The content weight value of the filled container 1a manufactured by the fixed weight filling machine 4 and measured by the weight sorter 5 is normally distributed as described above.

  In order to maximize the use efficiency of the raw material, which is an article to be filled in the container 1, from the viewpoint of cost, that is, to minimize the amount of raw material loss for the manufacturer, the content weight value target of the filled container 1a to be manufactured It is necessary to set the management target weight value Wqo, which is a value, too large so that the content weight of the filled container 1a becomes too large and there is not enough room from the nominal weight. On the contrary, it is necessary to select the management target weight value Wqo so that the content weight of the filled container 1a becomes too small and the number of defective products does not increase.

  A specific example will be given and explained.

  For example, it is assumed that the weighing error of the weight sorter 5 is anticipated in the filled container 1a filled with the nominal weight Qn = 100 g and the standard deviation Ws = 1 g, and Wsc = 1 g is set.

  Defective products are selected using the reference weight value Qt = Qn + Wsc = 101 g as the boundary weight value.

  When, for example, 1000 pieces of the filled containers 1a are weighed and sorted, the amount of loss of the raw material is calculated depending on the set value of the sorting margin width K.

  Here, the definition of the raw material loss amount is as follows: for the content weight of the filled container 1a measured by the weight sorter 5, the weight difference from the nominal weight value and the content weight of the filled container 1a to be sorted as defective (reference) There are various weight values less than the weight value Qt, but they are nominal weight values), and these total values are the total raw material loss.

  The definition of the raw material loss amount is defined as the difference between the weight of the content weight of the filled container 1a measured by the weight sorter 5 and the content weight of the filled container 1a to be sorted as a defective product (reference weight value). There are various weight values less than Qt, which are assumed to be the reference weight value Qt), and these total values may be used as the total raw material loss amount.

(1) When the selection margin K = 2.88 (sigma) is set As shown in FIG. 7, the standard deviation Ws = 1g with respect to the nominal weight Qn = 100g, and the reference weight value Qt = Qn + Wsc = 101g. It becomes. Since the sorting margin K = 2.88 sigma and the average value Wxa of the content weight of the filled container 1a is controlled to the management target weight value Wqo, the value is Wqo = Qt + K · Ws = 103.88 g. Become.

  On the standard normal distribution table, 2.88 sigma has Z = 0.498, and the distribution probability of Z = Qt or less is 0.002. That is, the defective product rate = 0.002, and the number of generated defective products is 2 for 1000 filled containers 1a.

Therefore, the number of good products is
1000-2 = 998
The average loss of raw material per good product is
103.88g-100g = 3.88g
The total amount of raw material loss for non-defective products is
998 × 3.88 = 387.24 g
It becomes.

On the other hand, the amount of raw material loss due to defective products, assuming that the content weight of defective products is nominal weight,
100x2 = 200g
It becomes.

Therefore, the total amount of raw material loss for non-defective and defective products is
387.24 g + 200 g = 407.24 g
It becomes.

(2) When the selection margin K = 2.65 (sigma) is set K = 2.65 (sigma) to reduce the loss of non-defective products instead of slightly reducing the selection margin K and increasing the number of defective products. ), As shown in FIG. 8, the average value of the content weight of the filled container 1a is 103.65 g.

  On the standard normal distribution table, 2.65 sigma is Z = 0.4096, and the distribution probability of Z = Qt or less is 0.004. That is, the defective product rate = 0.004, and the number of defective products generated is 4 for 1000 filled containers 1a.

Therefore, the number of good products is
1000-4 = 996
The average loss of raw material per good product is
103.65g-100g = 3.65g
The total amount of raw material loss for non-defective products is
996 × 3.65 = 3635.4 g
It becomes.

On the other hand, the amount of raw material loss due to defective products is
100x4 = 400g
It becomes.

Therefore, the total amount of raw material loss for non-defective and defective products is
3635.4 g + 400 g = 4035.4 g
It becomes.

(3) When the selection margin width K = 1.88 (sigma) is set When the selection margin width K is further reduced and K = 1.88 (sigma) is set, as shown in FIG. The average value of the content weight of the container 1a is 102.88 g.

  On the standard normal distribution table, 1.88 sigma is Z = 0.4699, and the distribution probability of Z = Qt or less is 0.03. That is, the defective product rate = 0.03, and the number of defective products generated is 30 for 1000 filled containers.

Therefore, the number of good products is
1000-30 = 970
The average loss of raw material per good product is
102.88g-100g = 2.88g
The total amount of raw material loss for non-defective products is
970 × 2.88 = 2793.6 g
It becomes.

On the other hand, the amount of raw material loss due to defective products is
100x30 = 3000g
It becomes.

Therefore, the total amount of raw material loss for non-defective and defective products is
2793.6 g + 3000 g = 5793.6 g
It becomes.

  When the weight of the filled container 1a manufactured as described above is normally distributed, when the variation amount Ws is given and the nominal weight Qn and the reference weight value Qt for defective product selection are set, the sorting margin width K is changed. When the management target weight value Wqo is variously changed by this, the average value Wxa of the weight measurement values in the weight sorter 5 of the filled container 1a manufactured by the fixed weight filling machine 4 matches the management target weight value Wqo. It is possible to calculate the amount of loss of the raw material in a predetermined number of processing when control is performed. In the case described above, it can be seen that there is a value of K that minimizes the amount of material loss between the selection margins K = 2.88 and K = 1.88.

  Therefore, in this embodiment, a mode for determining the management target weight value Wqo that maximizes the use efficiency of the raw material is set by operating the setting display unit of the control device 15 of the weight sorter 5.

  In accordance with this setting, the control device 15 determines a management target weight value Wqo that minimizes the raw material loss amount by the following procedure.

  Prior to the start of the operation, a sample product having a weight substantially equal to the reference weight value Qt is manufactured by the fixed weight filling machine 4 and is weighed by the weight sorter 5 to obtain the standard deviation Ws.

  When the maximum value is obtained from the case where the sorting margin width K is set to the minimum value (that is, the management target weight value Wqo is equal to the reference weight value Qt) (that is, the management target weight value Wqo is filled with respect to the reference weight value Qt). For the variation of the weight measurement value of the weight sorter 5 of the finished container 1a, the value of the sorting margin K is set to a value that is as large as 3.5 sigma and 4 sigma). Then, the management target weight value Wqo is changed, the total raw material loss amount is obtained by the above definition, and compared with each other, and the management target weight value Wqo when the total raw material loss weight is minimum is determined.

  The operation after determining the management target weight value Wqo that minimizes the total material loss weight is the same as the above-described case where the management target weight value Wqo is determined according to the setting of the allowable defective product rate R (%). .

  In this way, the control target weight value Wqo is determined and the quantitative weight is determined so as to suppress the loss amount of the raw material article of the filled container 1a selected as a defective product and the loss amount of the raw material article exceeding the nominal weight of the non-defective product. Since the target filling weight of the filling machine 4 is controlled, the loss of the raw material article can be suppressed and the usage efficiency of the raw material article can be maximized.

  In this embodiment, the control target weight value Wqo is calculated by the control device 15 of the weight sorter 5, and the difference wdx from the average value Wxa of the content weight Wx of the filled container 1 a is calculated by the control device 12 of the quantitative weight filling machine 4. The weight data such as the average value Wxa of the content weight Wx of the filled container 1a is transmitted to the control device 12 of the quantitative weight filling machine 4, and the control target weight value Wqo is calculated by the control device 12. The filling target weight may be controlled by calculating the difference wdx between the average value Wxa of the content weight Wx of the filled container 1a and the management target weight value Wqo by the control device 12.

  Or you may comprise the control apparatus 15 of the weight sorter 5, and the control apparatus 12 of the fixed weight filling machine 4 by one control apparatus.

(Embodiment 2)
In the above-described embodiment, the description has been made by applying the fixed weight filling machine 4 for filling the article 3 into the packaging container 1 with a constant weight. However, the present invention provides a fixed volume for filling the article into the packaging container 1 with a constant volume. The same applies to the filling machine.

  FIG. 10 is a schematic configuration diagram of a filling and weighing system provided with a fixed volume filling machine 4a for filling an article 3 into a packaging container 1 with a fixed volume instead of the fixed weight filling machine 4, and corresponds to FIG. Are denoted by the same reference numerals.

  In this filling and weighing system, products to be produced are sold at a price corresponding to the weight value. Therefore, if the true weight value of the internal volume of the filled container 1a filled with the article 3 by the fixed volume filling machine 4a is smaller than the nominal weight Qn, it cannot be made into a product.

  Even if the predetermined target filling volume is set by the fixed volume filling machine 4a and the article 3 is filled into the container 1, there is a variation in the filling volume by the fixed volume filling machine 4a, and the weight value varies accordingly.

  Moreover, since the apparent specific gravity of the article 3 differs when the temperature of the article 3 is different, the weight varies according to the variation of the temperature of the article 3 even when the predetermined volume is filled.

  The control device 12a of the fixed volume filling machine 4a controls the volume of the article 3 filled in the container 1 so that the set target filling volume Vt is obtained.

  The fixed volume filling machine 4 a of this embodiment is an auger type filling machine, and fills the container 1 with a predetermined volume amount of articles 3 corresponding to a predetermined rotation speed of the auger 9. The control device 12a of the fixed volume filling machine 4a counts the number of pulses from the pulse generator 11 provided on the rotating shaft of the auger 9 with a built-in counter.

The volume V of the article 3 at room temperature and the number of pulses C corresponding to the rotational speed of the auger 9 are previously determined by a test in the adjustment stage before starting the operation operation. V = kc · C (8)
And a proportionality constant kc is determined and related.

When the apparent specific gravity of the article 3 in a predetermined environmental condition is ρ, the relationship between the filling weight W and the volume V is W = ρ · V (9)
It is. The relationship between the number of pulses C and the filling weight W is given by the equations (8) and (9): C = V / kc = (1 / ρ · kc) · W (10)
become.

In the fixed volume filling machine 4a of the auger set, a predetermined number of pulses (target number of filling pulses) Ct for filling a predetermined volume Vt,
Ct = Vt / kc (11)
And the auger 9 is rotated until the number of pulses reaches Ct to obtain a predetermined filling volume. The weight of the volume 3 of the article 3 is Wt = ρ · Vt (12) because the apparent specific gravity is ρ under predetermined environmental conditions.
It becomes. However, when the environmental conditions change and the value of the apparent specific gravity ρ changes, the content weight of the filled container 1a changes from Wt even if it is filled with a predetermined number of pulses Ct. When defective products are selected based on the reference weight value Qt, defective products increase or raw material loss increases.

  At the start of operation, the weight of the filled container 1a, for example, a weight larger than the reference weight value Qt by a weight Wd that is twice the minimum scale of the displayed weight value is set as the initial filling weight Wt, and the controller for the quantitative volume filling machine 4a Set to 12a.

The initial filling weight Wt is expressed by the equations (10) and (11). Ct = (1 / ρ · kc) · Wt (13)
Are converted into a target pulse number Ct corresponding to the rotational speed of the auger 9, and the individual filled containers 1a are filled with the articles 3 in the container 1 with the pulse number Ct and sent to the weight sorter 5, and the content weight Wx Is measured.

  Since the value of the apparent specific gravity ρ varies depending on the environmental conditions, increase / decrease control of the filling volume is performed on the fixed volume filling machine 4a side.

Therefore, as in the above embodiment, the content weight of the filled container 1a transmitted from the weight sorter 5 is increased or decreased from the average value Wxa, the management target weight value Wqo, and the difference wdx by the following equation (14). To the number of power pulses cdx cdx = (1 / ρ · kc) · wdx (14)
Ct-cdx → Ct (15) in consideration of the codes that are converted and transmitted at the same time
And the new target filling pulse number is obtained so that the content weight of the filled container 1a becomes the management target weight value Wqo, and the article 3 is filled into the container 1.

In the calculation of equation (14), the value of the number of corrected pulses also changes with the change in apparent specific gravity ρ. Therefore, from the relationship of equation (14), ρ = (1 / kc · Ct) · Wx
Therefore, using the P average weight values Wxa transmitted at the same time as the latest apparent specific gravity value ρn, ρn = (1 / kc · Ct) · Wxa (16)
Cdx = (1 / ρn · kc) · wdx (17) according to equation (16)
It is preferable to correct as follows. However, since cdx is a small value, the apparent specific gravity value ρ obtained at the time of adjustment may be used.
Other configurations are the same as those of the above-described embodiment.

(Embodiment 3)
In each of the above-described embodiments, description has been made by applying the present invention to the quantitative filling machines 4 and 4a for filling the container 1 with the article 3 having a constant weight or a constant volume. The same can be applied when filling a bag or the like.

  FIG. 11 is a schematic configuration diagram of a system using the combination weigher 20, and parts corresponding to those in FIG.

  The system of this embodiment includes a combination weigher 20 for combining and discharging articles such as confectionery, a packaging machine 21 for packaging the articles discharged from the combination scale 20, and the weight of the packaged goods from the packaging machine 21. And a weight sorter 5a for measuring and sorting.

  In the combination weigher 20, an article (not shown) is supplied from a supply device (not shown) to the central portion of the dispersion feeder 23, and the dispersion feeder 23 sends the article toward the peripheral edge by vibration, and radially around the dispersion feeder 23. It is conveyed to a plurality of installed linear feeders 24. A vibration device is attached to each linear feeder 24, and each linear feeder 24 is vibrated to convey an article and put it into a plurality of supply hoppers 25 installed radially around the linear feeder 24. Each supply hopper 25 temporarily holds the article, opens a discharge gate that can be opened and closed at the bottom, and puts the article into each weighing hopper 26 disposed below each supply hopper 25. In each weighing hopper 26, the weight of the loaded article is weighed by each weight sensor 27 such as a plurality of load cells.

  The detection output of each weight sensor 27 is given to the control device 22 arranged inside the combination scale 20, and the control device 22 performs a combination calculation based on the weight value of each weight sensor 27, so that the combination weight is predetermined. The combination of the weighing hoppers 26 that is within the weight range and matches or is closest to the target combination weight is selected as the optimal combination, the gate for discharging the weighing hopper 26 of the selected optimal combination is opened, the article is discharged, It is put into the packaging machine 21 through the collecting chute 28.

  The packaging machine 21 receives the articles discharged from the weighing hopper 26 of the optimum combination of the combination scale 20, packages the articles with a packaging material such as a packaging bag, and discharges the articles as a packaged product 1b to the transport conveyor.

  In this embodiment, the combination weigher 20 and the packaging machine 21 constitute a filling device that fills the packaging bag with the articles weighed in combination.

  In the weight sorter 5a, as in each of the above-described embodiments, if the content weight value of the packaged product 1b measured by the weighing conveyor 14 is less than the reference weight value Qt, it is determined as a defective product, and is used as a rear-stage sorting device. As shown in the schematic plan view of FIG. 12 by operating the flipper 29, the packaged goods 1b determined to be defective are dropped and excluded from the main transport line 17 of the conveyor.

  In the combination weigher 20, a target combination weight value Wt and an upper limit weight value Wu are set from a setting display unit (not shown), and a combination calculation is performed based on the weight measurement values of articles stored in the plurality of weighing hoppers 26. Is the target combination weight value Wt or more and is in a predetermined weight range of the upper limit weight value Wu or less and the closest combination to the target combination weight value Wt is selected as the optimum combination, and the article stored in the selected weighing hopper 26 Is put into the packaging machine 21 and packed in the packaging machine 21 to obtain a packaged product 1b.

  Therefore, the weight measurement value of the contents of the packaged product 1b is in a predetermined weight range that is not less than the target combination weight value Wt and not more than the upper limit weight value Wu, and the distribution probability increases as the target combination weight Wt is approached.

  However, since there is a variation error in the measured weight value of the weighing hopper 26 which is a measuring instrument of the combination weigher 20, the true weight of the contents of the packaged product 1b is from a weight less than the target combined weight value Wt to an upper limit weight value. Distributes to a weight range exceeding Wu. Furthermore, the distribution of the weight measurement value of the weight sorting machine 5 of the packaged goods 1b having such a weight distribution is further spread by the measurement variation of the weight sorting machine 5 and has a shape as shown in FIG.

  This distribution is not a normal distribution, and a probability distribution function of a normal distribution cannot be applied as in the above embodiment.

In this case, the management target weight value Wqo is determined by setting the target combination weight value Wt and the upper limit weight value Wu in the adjustment stage before the start of the operation operation, and manufacturing the packaged product 1b as many combination selection products as possible. Then, the weight is measured by the weight sorter 5, and the average weight value Wxa and the minimum weight value Wmin at the adjustment operation stage in the weight measurement value Wx of the contents of the packaged product 1b are obtained, and the difference between them is calculated as the downward maximum variation width (Wxa -Wmin) as the management target weight value Wqo,
Wqo = Qt + (Wxa−Wmin) (18)
And set. The lower maximum variation width (Wxa−Wmin) corresponds to the product K · Ws of the selection margin width K and the standard deviation Ws in the above equation (5).

  That is, control is performed so that defective products are selected only with a very small probability in combination products.

  However, since the number of combination selection products in the adjustment stage cannot be increased due to the working time and cost, the downward variation width Dw (=) which is the width of the average weight value Wxa and the minimum weight value Wmin obtained in the adjustment operation stage. Wxa−Wmin) may be statistically biased.

When the operation is started, the lower maximum variation width Dw is obtained for each control period in which the weight of P control units is measured. Therefore, the control is performed by continuously adding a plurality of lower maximum variation widths Dw for each control period. By dividing by the number of periods and using the average weight value Wxa and the minimum weight value Wmin during operation, the average value Dwa of the lower maximum variation width is calculated as Dwa = Wxa−Wmin, so that the lower maximum variation width is statistically calculated. Increase the reliability and set the management target weight value Wqo with the average value Dwa Wqo = Qt + Dwa (19)
And after updating it,
The difference wdx is obtained by Wxa−Wqo = wdx.

The absolute value and sign of the difference wdx are transmitted to the combination weigher 20, and the combination weigher 20 calculates the target combination weight value Wt based on the absolute value and sign of wdx Wt−wdx → Wt (20)
And correct.

  Further, the packaged product 1b which is a combination selection product is manufactured at the adjustment stage before the start of the operation operation or the operation operation stage, and the weight of the packaged product 1b is measured by the weight sorter 5.

  In the control device 5a of the weight sorter 5, based on the measurement result of the weight of the packaged product 1b, the number of the packaged products 1b for each measured weight value of the contents of the packaged product 1b is set to a minimum display scale, for example, 1 g. A frequency distribution table classified and aggregated according to weight values divided in steps is created and stored in a memory. That is, a frequency distribution table is created in which each measured weight value of the contents of the packaged product 1b is associated with the number of packaged products 1b with each measured weight value. Based on the frequency distribution table, the management target weight value Wqo corresponding to the allowable defective product rate R set in the control device 15a is determined.

  Specifically, the affiliation number of the packaged product 1b for each measured weight value in the frequency distribution table is divided by the total number of the measured packaged product 1b and replaced with the distribution ratio value for each measured weight value.

  Now, when the allowable defective product rate R (%) is set, the weight measured in the minimum weight display scale step in order from the distribution ratio r <1> (%) corresponding to the minimum measured weight value W <1>. As the value is increased, the distribution ratio is added, and the measured weight value W <i> in which the added value of the distribution ratio is equal to or larger than the allowable defective product rate R is detected for the first time.

  The measured weight value W <i> and the average weight value Wxa of all the measured weight values are obtained, and the downward maximum variation width according to the allowable defective product rate R is defined as follows.

Maximum downward variation width = Wxa−W <i>
Furthermore, the management target weight value Wqo corresponding to the allowable defective product rate R is
Wqo = Qt + Wxa-W <i>
And decide.

  In this way, by setting the allowable defective product rate R (%) in the control device 15 of the weight sorter 5, the management target weight corresponding to the allowable defective product rate R based on the frequency distribution table created in advance. The value Wqo is determined.

After the management target weight value Wqo is determined, the difference wdx is obtained by Wxa−Wqo = wdx and the absolute value and the sign of the difference wdx are transmitted to the combination weigher 20 in the same manner as in the above embodiment. Based on the absolute value and the sign of wdx, Wt-wdx → Wt
And correct.

  That is, the difference between the average value Wxa of the contents of the packaged product 1b and the management target weight value Wqo is obtained. If the average weight value Wxa of the packaged product 1b is larger than the management target weight value Wqo, the combined target weight value Wt is set. When the average weight value Wxa of the packaged product 1b is smaller than the management target weight value Wqo, the content weight Wx of the packaged product 1b measured by the weight sorter is increased by increasing the target combination weight value Wt. It is controlled so that it always becomes a value near the management target weight value Wqo. The weight range defined by the target combination weight value Wt and the upper limit weight value Wu is constant, and the predetermined weight range is moved with a constant weight width according to the change of the target combination weight value Wt.

  Next, the determination of the management target weight value Wqo that maximizes the use efficiency of the raw material as in the above embodiment will be described.

  As described above, the weight value measured by the weight sorter 5 of the packaged product 1b manufactured by selecting the optimum combination with the combination weigher 20 is not normally distributed.

  Before starting the operation operation, for example, the combination selection product is manufactured by setting the reference weight value Qt to the target combination weight value Wt, and the frequency distribution table in which the measured weight value and the number are associated as described above is created. Further, an average value Wxa of all measured weight values is obtained.

As described above, since the minimum measured weight value is W <1>, the maximum value of the downward maximum variation width is Wxa−W <1>. The management target weight value Wqo is decreased from Wqo = Qt + Wxa−W <1> by the minimum display scale of weight until Wqo = Qt.
Wqo = Qt + Wxa-W <1>, Qt + Wxa-W <2>, ...
..., Qt + Wxa-W <v>, ..., Qt
Since the average value Wxa of the measured weight value Wx is controlled to coincide with the management target weight value Wqo, the distribution of the measured weight value Wx is changed according to the change of the management target weight value Wqo. It changes as shown in FIG. FIG. 14 representatively shows the distribution of the measured weight value Wx when Wqo = Qt + Wxa−W <1>, Wqo = Qt + Wxa−W <v>, and Wqo = Qt.

  Thus, for each of the management target weight values Wqo decreased by the minimum display scale of the weight, the frequency distribution table shows the number of non-defective products whose measured weight value Wx is greater than or equal to the reference weight value Qt and the number of defective products less than the reference weight value Qt Then, the number of defective products and non-defective products in a predetermined number is calculated, the total material loss amount is calculated based on the above definition, and the management target weight value Wqo when the total material loss amount is minimum is determined.

  FIG. 15 shows an example of each frequency distribution table when the management target weight value Wqo is decreased from Wqo = Qt + Wxa−W <1> to Wqo = Qt by 1 g which is the minimum display scale of weight. In this example, the nominal weight Qn = 276 g and the reference weight value Qt = 280 g. Since the average value Wxa of the measured weight values Wx is controlled so as to coincide with the management target weight value Wqo, if the management target weight value Wqo is decreased by 1 g which is the minimum display scale, the frequency distribution table is also 1 g accordingly. It will shift one by one.

  As shown in FIG. 15, as the management target weight value Wqo is decreased by 1 g, which is the minimum weight display scale, the frequency distribution table is set to the minimum display scale based on the average value Wxa (= 300 g). Based on the frequency distribution table shifted every time, the reference weight value Qt is used as the boundary weight value, the number of defective products and the number of non-defective products are calculated, the total raw material loss amount is calculated based on the above definition, The management target weight value Wqo when the total raw material loss amount is minimum is determined.

DESCRIPTION OF SYMBOLS 1 Container 1a Filled container 1b Packaged goods 3 Goods 4 Fixed weight filling machine 4a Fixed volume filling machine 5,5a Weight sorter 8,13 Load cell 12 Control apparatus of fixed weight filling machine 12a Control apparatus of fixed volume filling machine 14 Measuring conveyor 15, 15a Weight sorter control device 20 Combination weigher 21 Packaging machine

Claims (9)

Filling Weight of the article to the container is disposed downstream of the auger quantitative weight filling apparatus for filling such that the target fill Weight, weight sorter wherein the article to measure the weight of the pre-filled container filled Because
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Depending on the rate of occurrence of defective products to be set on the setting means, a determining means for the target fill weight of the quantitative weight filling apparatus of the auger, is determined as a management target weight value,
Calculating a deviation between an average weight value of the contents of the filled container and the management target weight value, and including a control means for outputting the calculated deviation to the auger-type fixed weight filling apparatus;
The auger-type fixed weight filling device is to increase or decrease the target filling weight so as to cancel the deviation.
A weight sorter characterized by that. The weight of the filled container in which the article is filled, which is arranged at the subsequent stage of the auger-type quantitative volume filling apparatus for filling the container so that the filling volume of the article becomes the target filling volume corresponding to the target filling weight. A weight sorter for measuring
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Determining means for determining the target filling weight of the auger type quantitative volume filling device as a management target weight value in accordance with the occurrence rate of defective products set in the setting means;
Calculating a deviation between an average weight value of the contents of the filled container and the management target weight value, and a control means for outputting the calculated deviation to the auger-type fixed volume filling device;
The auger-type fixed volume filling device is to increase or decrease the target filling weight so as to cancel the deviation.
A weight sorter characterized by that. Based on the weights of the articles weighed by the plurality of weighing hoppers to which the articles are supplied, the combined weight of the weights of the articles is a predetermined weight range with the target combination weight as a lower limit, and the target combined weight is The combination of the weighing hoppers close to each other, the combination weigher that discharges the articles from each selected weighing hopper, and the packing device that fills the containers with the articles discharged from the combination weighers are arranged at the rear stage of the article. A weight sorter for measuring the weight of a filled container filled with
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Determining means for determining the target combination weight of the combination weigher as a management target weight value according to the occurrence rate of defective products set in the setting means;
A control means for calculating a deviation between an average weight value of the contents of the filled container and the management target weight value, and outputting the calculated deviation to the combination weigher;
The combination weigher controls to increase or decrease the target combination weight so as to cancel the deviation.
A weight sorter characterized by that. A weight sorter that is disposed in a subsequent stage of a filling device that fills a container so that a filling amount of an article becomes a target filling amount, and measures the weight of a filled container filled with the article,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
The amount of use of the article that is the contents of the filled container determined to be defective and the amount of use exceeding the nominal weight of the article that is the contents of the filled container determined to be non-defective Determining means for determining the target filling amount of the filling device as a management target weight value so as to suppress the total usage amount;
The determining means determines the management target weight value based on the reference weight value, a weight distribution of the contents of the filled container, and the nominal weight, and the determining means includes: When the weight distribution of the contents of the filled container is a normal distribution, and the management target weight value is variously changed, the average weight value of the contents of the filled container is the changed management target weight. The management target weight value is determined so that the total usage calculated when it is assumed to be controlled to match the value is minimized,
The filling device controls the target filling amount to the management target weight value.
A weight sorter characterized by that . The determining means determines the management target weight value based on the reference weight value, the amount of variation in the measured weight value of the filled container, and the occurrence rate of the defective product.
The weight sorter according to claim 1 or 2 . Filling the filling weight of the article to the container, and quantifying the weight filling device auger filling so that the target filling Weight, disposed downstream of the quantitative weight filling apparatus of the auger, wherein the article is filled A filling and weighing system comprising a weight sorter for measuring a weight of a used container,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Depending on the rate of occurrence of defective products to be set on the setting means, a determining means for the target fill weight of the quantitative weight filling apparatus of the auger, is determined as a management target weight value,
The deviation between the average weight value of the contents of the filled container and the management target weight value is calculated, and the target filling weight of the auger type quantitative weight filling apparatus is controlled to increase or decrease so as to cancel the deviation. Control means;
A filling and weighing system comprising: Filling volume of the article to the container, and quantifying the volume filling device auger filling so that the target fill volume amount corresponding to the target fill weight, disposed downstream of the quantitative volume filling device of the auger, the A filling and weighing system comprising a weight sorter for measuring the weight of a filled container filled with an article,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Determining means for determining the target filling weight of the auger type quantitative volume filling device as a management target weight value in accordance with the occurrence rate of defective products set in the setting means;
The deviation between the average weight value of the contents of the filled container and the management target weight value is calculated, and the target filling weight of the auger type quantitative volume filling device is controlled to increase or decrease so as to cancel the deviation. Control means;
A filling and weighing system comprising: Based on the weights of the articles weighed by the plurality of weighing hoppers to which the articles are supplied, the combined weight of the weights of the articles is a predetermined weight range with the target combination weight as a lower limit, and the target combined weight is A combination weighing scale that selects a combination of the weighing hoppers close to each other, discharges articles from each selected weighing hopper, and a filling device that fills the containers with the articles discharged from the combination weighing scale; A filling and weighing system comprising a weight sorter disposed and measuring a weight of a filled container filled with the article,
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
Setting means for setting the occurrence rate of the defective products;
Determining means for determining the target combination weight of the combination weigher as a management target weight value according to the occurrence rate of defective products set in the setting means;
A control means for calculating a deviation between an average weight value of the contents of the filled container and the management target weight value, and for increasing / decreasing the target combination weight so as to cancel the deviation;
A filling and weighing system comprising: A filling device for filling the container so that the amount of the article to be filled becomes a target filling amount, and a weight sorter for measuring the weight of the filled container filled with the article, which is arranged at a subsequent stage of the filling device. A filling and weighing system comprising:
Based on the measured weight value of the filled container and the reference weight value larger than the nominal weight for the filled container, the filled container is a non-defective product whose weight value is not less than the reference weight value. And a discriminating means for discriminating between defective products less than the reference weight value,
The amount of use of the article that is the contents of the filled container determined to be defective and the amount of use exceeding the nominal weight of the article that is the contents of the filled container determined to be non-defective Determining means for determining the target filling amount of the filling device as a management target weight value so as to suppress a total use amount;
Control means for controlling the target filling amount of the filling device to the management target weight value,
The determining means determines the management target weight value based on the reference weight value, a weight distribution of the contents of the filled container, and the nominal weight, and the determining means includes: When the weight distribution of the contents of the filled container is a normal distribution, and the management target weight value is variously changed, the average weight value of the contents of the filled container is the changed management target weight. The management target weight value is determined so that the total usage calculated when it is assumed to be controlled to match the value is minimized.
A filling weighing system characterized by that.

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