JP2006322751A - Weighing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a weighing device that can easily verify whether weighing by a weighing means is correct, and can be easily verified even by an operator having no specialized knowledge or experience, and improves verification workability. , Try to prevent verification mistakes.
SOLUTION: A weighing unit 7 provided on a weighing conveyor 3 for outputting a measured value corresponding to the weight of an object to be weighed, and a statistical unit 11 for statistically measuring a measured value by the measuring unit 7 and outputting a statistical value indicating variation. In the weighing device 1 including the display unit 9 for displaying the measurement value and the statistical value, and the parameter setting unit 12 for setting the parameter relating to the measurement, the statistical unit 11 is used when the same object W is repeatedly measured. The repeated statistical value representing the variation of the repeated weighing value is calculated, the weighing accuracy of the weighing means 7 is calculated based on the repeated statistical value, and the display means 9 is set by the weighing accuracy of the weighing means 7 and the parameter setting means 12. And an allowable value representing the upper limit of the weighing accuracy is displayed side by side.
[Selection] Figure 1

Description

  The present invention relates to a weighing device that measures the weight of an object to be weighed received from a preceding conveyor to a weighing conveyor during conveyance and determines whether the object to be weighed is within an allowable range based on the measurement result.

  In factories and the like, a weight sorter is used to check whether the weight of an article is excessive or insufficient while the article is being conveyed in a line (see, for example, Patent Document 1). As shown in FIG. 5, the weight sorting apparatus 100 receives the article W carried out from the carry-in conveyor 101 into the weighing conveyor 102, and sends a weighing signal corresponding to a load change caused by the carried-in article W from the weighing machine 103. Output to the calculation unit 104.

  On the other hand, the timing for starting the delivery of the article W to the weighing conveyor 102 is optically detected by a loading sensor (not shown) disposed on the loading side of the weighing conveyor 102, and the loading detection signal is output to the weight calculation unit 104. The The weight calculation unit 104 performs sampling of the weighing signal for a predetermined time after the time necessary for the article W to completely transfer onto the weighing conveyor 102 after receiving the carry-in detection signal, and the average value of the sampling values And the calculated value is output to the determination unit 105 as the weight value of the article W.

The determination unit 105 determines whether or not the calculated weight value is within a predetermined weight range, and outputs a selection signal corresponding to the determination result to the selection control means 106. The sorting control means 106 delays and outputs a sorting signal to the sorting machine 108 provided on the sorting conveyor 107. The sorter 108 allows the article W carried out of the weighing conveyor 102 to pass through if it is determined to be within the predetermined weight range, and excludes the article W from the selection conveyor 107 if it is determined to be outside the predetermined weight range. To do.
Japanese Patent No. 2925252

By the way, in the above-described weight selection apparatus, the object to be weighed (master work) is flowed a plurality of times (about 30 to 60 times) for the confirmation (confirmation mode) of the apparatus before the start of production or periodically, and the measurement accuracy is verified. Doing work. And the administrator judged the verification result.
However, verification of whether or not the weighing of the measuring means is correct is performed by the administrator determining the allowable error based on specialized knowledge and experience, calculating the statistical result, and judging based on the allowable error and the statistical result. I was going. For this reason, there has been a problem that verification cannot be performed easily. In addition, in the weight selection device disclosed in Patent Document 1, the standard deviation can be calculated by key operation at the time of test weighing. However, the verification of the measurement accuracy based on the standard deviation is the expert knowledge of the administrator after all. And was done by experience. For this reason, verification is difficult for an operator who does not have specialized knowledge and experience, verification workability is poor, and a mistake in verification of weighing accuracy may occur.

  Therefore, the present invention has been made in view of the above situation, and can easily verify whether the weighing of the weighing means is correct, and can be easily verified even by an operator having no specialized knowledge or experience. The purpose of this is to improve the verification workability and prevent verification errors.

Next, means for solving the above problems will be described with reference to the drawings corresponding to the embodiments.
The weighing device 1 according to the first aspect of the present invention includes a weighing conveyor 3 that sequentially conveys the objects to be weighed, and weighing means that is provided on the weighing conveyor 3 and outputs a weighing value according to the weight of the objects to be weighed W. 7, a statistical unit 11 that statistically outputs the statistical value representing the dispersion by statistically measuring the measurement value by the measurement unit 7, a display unit 9 that displays the measurement value and the statistical value, and a parameter setting that sets a parameter related to the measurement In a weighing device 1 comprising means 12,
The statistical means 11 calculates a repeated statistical value representing variation of repeated measured values when the same object W is repeatedly measured, calculates the measurement accuracy of the weighing means 7 based on the repeated statistical values, The display means 9 displays the weighing accuracy of the weighing means 7 calculated by the statistical means 11 and the allowable value set by the parameter setting means 12 and representing the upper limit of the weighing accuracy. .

  According to such a configuration, when the weighing object W is weighed a plurality of times before the start of production, the weighing accuracy of the weighing means 7 based on repeated statistical values (standard deviations) representing variations obtained by the statistical means 11 And the allowable value representing the upper limit of the weighing accuracy of the weighing means 7 set in advance by the parameter setting means 12 are displayed on the display means 9 and can be viewed at the same time to verify whether the weighing of the weighing means 7 is correct. Can be easily performed.

  The weighing apparatus 1 according to claim 2, wherein the statistical unit 11 further represents a deviation of the repeated weighing value from the reference weight of the object to be weighed W set by the parameter setting unit 12 and the repeated weighing value. Bias calculating means 16 for calculating repeated statistical values is provided, and weighing accuracy calculating means 17 for calculating the weighing accuracy of the weighing means 7 based on the repeated statistical values representing the variation and the repeated statistical values representing the bias is provided. It is characterized by that.

  According to such a configuration, by setting the actual weight of the object W to be measured by the parameter setting unit 12, the true value (actual weight) is subtracted from the average value of the repeated measurement values, so that one of the entire measurement distributions is obtained. Various biases with different amounts of deviation can be obtained. This deviation and variation are added to obtain the weighing accuracy of the weighing means 7.

  The weighing apparatus 1 according to claim 3, wherein the parameter setting unit 12 selects a formula for calculating the weighing accuracy of the weighing unit 7 that is set in advance to determine a margin with respect to the allowable value, and the statistical unit 11. Is characterized in that the weighing accuracy of the weighing means 7 is calculated based on the calculation formula.

  According to such a configuration, for example, it is possible to select a calculation formula for calculating the weighing accuracy of the weighing means 7 such as standard deviation (sigma) × 3, standard deviation + | bias |, variation + | bias | Become.

  5. The weighing apparatus according to claim 4, wherein the parameter setting means 12 sets a coefficient for determining a margin for the allowable value, and the statistical means 11 measures the weighing of the weighing means 7 based on the coefficient. It is characterized by calculating accuracy.

  According to such a configuration, for example, the standard deviation (sigma) as a repeated statistical value representing variation can be set to 3 times (3σ) to 6 times (6σ), and the weighing accuracy of the weighing means 7 can be further increased. Coefficients for calculation with strict accuracy can be set.

  The measuring device 1 according to claim 5 includes a determination unit 18 that compares the statistical result calculated by the statistical unit 11 and the allowable value set by the parameter setting unit 12. The determination result obtained by the above is displayed on the display means 9.

  According to such a configuration, the statistical result (variation, bias) obtained by the statistical means 11 and the allowable value indicating the upper limit of the measurement accuracy preset by the parameter setting means 12 are displayed on the display means 9. At the same time, it is possible to visually recognize the judgment result (whether it is within the allowable range) obtained by the judgment means 18 on the display means 9 so that even an operator without specialized knowledge or experience can easily measure. It is possible to verify whether the measurement of the means 7 is correct.

  According to the weighing apparatus of the first aspect of the present invention, the weighing accuracy of the weighing means based on the repeated statistical value (standard deviation) representing the variation obtained by the statistical means, and the upper limit of the weighing means preset by the parameter setting means. Is displayed on the display means and can be visually recognized at the same time, so that it is possible to easily verify whether the weighing of the weighing means is correct.

  Further, according to the weighing device of the second aspect, since the bias is calculated based on the reference weight of the object to be weighed set by the parameter setting means and the measurement accuracy of the measurement means is calculated, Various misalignments are corrected. By adding the deviation and the variation to obtain the measurement accuracy, and using this measurement accuracy, it is possible to compare a more strict statistical result with an allowable value.

  Furthermore, according to the weighing device of the third aspect, a calculation formula for calculating the weighing accuracy of the weighing means can be arbitrarily selected. Thereby, measurement precision can be selected with various precision, and goods management can be performed with different level precision.

  Further, according to the weighing device of the fourth aspect, it is possible to set a coefficient for calculating the weighing accuracy of the weighing means with a stricter accuracy. Thereby, like the effect by the weighing device according to the third aspect, the weighing accuracy can be selected with various accuracy, and the merchandise can be managed with different level accuracy.

  Further, according to the weighing device of the fifth aspect, the measuring device includes a determination unit that compares the statistical result calculated by the statistical unit with the allowable value set by the parameter setting unit, and further obtained by the comparison of the determination unit. Since the determined determination result is displayed on the display means, even an operator having no specialized knowledge or experience can easily verify. As a result, verification workability can be improved and verification errors can be prevented.

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a weighing device according to the present invention.

  The weighing device 1 according to this embodiment can be suitably used for a weight sorting device 6 including a front conveyor 2, a weighing conveyor 3, a sorting conveyor 4, a sorting machine 5, and the like. The weighing device 1 can be used for verification of weighing accuracy by being used before the start of production in the weight sorting device 6 or during periodic device confirmation (confirmation mode).

  As shown in FIG. 1, the weighing device 1 has, as its basic configuration, a weighing means 7 for weighing an article W that is an object to be weighed (master work) provided on the weighing conveyor 3, a control unit 8, and a display means 9. With. The weighing means 7 includes a weighing instrument 10 attached to the weighing conveyor 3. The control unit 8 includes a statistical unit 11 that calculates statistics of repeated measurement values obtained by the weighing unit 7 and a parameter setting unit 12 that sets an allowable value. Here, the allowable value means an upper limit value of the weighing accuracy allowed by the production manager, and is set by the parameter input means 14 described later. The parameter setting means 12 further comprises a parameter storage means 13 for storing the allowable value in advance and a parameter input means 14 for inputting the allowable value. The display unit 9 is connected to the statistical unit 11 and the parameter setting unit 12, and can display a repeated statistical value representing variation and an allowable value representing an upper limit of the weighing accuracy.

  The weighing instrument 10 has the necessary minimum components shown in FIG. 1, and is configured to be able to weigh the weight of the article W carried into the weighing conveyor 3 from the preceding conveyor 2. Then, before the start of production, the weighing of the article W is performed a plurality of times, so that the repeated statistical value (variation) representing the variation of the repeated weighing value obtained by the weighing means 7 and the parameter setting means 12 are set in advance. The allowable value indicating the upper limit of the weighing accuracy is displayed side by side on the display means 9 and can be visually recognized at the same time, so that it is possible to easily verify whether the weighing of the weighing means 7 is correct.

FIG. 2 is a block diagram showing a more specific configuration example of the configuration shown in FIG.
In addition to the basic configuration shown in FIG. 1, the weighing device 1 preferably further includes the components shown in FIG. That is, in this specific configuration, the statistical unit 11 includes a variation calculating unit 15 and a bias calculating unit 16. Between the statistical unit 11 and the display unit 9, a measurement accuracy calculation unit 17 and a determination unit 18 are sequentially inserted.

  In this weighing device 1, the front conveyor 2, the weighing conveyor 3, and the sorting conveyor 4 are driven at the same conveyance speed. The weighing instrument 10 of the weighing conveyor 3 outputs a weighing signal corresponding to the load change to the weighing conveyor 3 with a predetermined response delay time. On the carry-in side of the weighing conveyor 3, an optical carry-in sensor (not shown) for detecting the carry-in timing of the article W is provided at a position away from the carry-in end by a predetermined distance in the direction of the pre-stage conveyor 2. The weighing signal from the weighing instrument 10 and the carry-in detection signal from the carry-in sensor are input to the statistical means 11 of the control unit 8.

  Upon receipt of the carry-in detection signal, the statistical means 11 performs sampling of the weighing signal for a predetermined time after the predetermined measurement start timing has elapsed, and the variation calculating means 15 calculates the average value as the weight value of the article W. Output to the accuracy calculation means 17. Usually, in dynamic weighing (dynamic weighing), sufficient measurement time cannot be taken, and therefore uncertainties occur in the weighing. When repeated weighing is performed, a distribution of measured values is obtained. The variation calculation means 15 calculates this distribution as a quantitative width. Specifically, it is obtained as 3 times (3 sigma) of standard deviation S (sigma) as a repeated statistical value representing variation.

  Here, the statistic means 11 can set a coefficient for determining a margin with respect to an allowable upper limit of the weighing accuracy. That is, the variation can be selected with a stricter accuracy, for example, 3 times (3σ) to 6 times (6σ). In this way, by enabling the statistical means 11 to set a coefficient for judging the margin of the allowable value, the processing for calculating the variation from the measurement result can be selected with various accuracy, and different levels can be selected. Product management can be performed with high accuracy.

  The bias calculation means 16 of the statistical means 11 calculates a repeated statistical value (bias) representing the bias based on the reference weight of the article W set in the parameter storage means 13. Here, the bias means a uniform shift amount of the entire metric distribution. Specifically, it is obtained by bias (X-bar) = average value of repeated weighing values−reference weight.

  The variation and the bias obtained by the statistical unit 11 are output to the weighing accuracy calculation unit 17, and the weighing accuracy calculation unit 17 calculates the weighing accuracy based on this. Here, the measurement accuracy refers to an evaluation index of the performance (measurement accuracy) of the balance obtained from variation and bias. Specifically, the measurement accuracy is obtained from a calculation formula such as standard deviation (S) × 3, standard deviation (S) + | bias |, variation + | bias |.

  Thus, by calculating the measurement accuracy, the uniform deviation amount of the entire distribution of the measurement is corrected, and a stricter statistical result and the allowable value can be compared.

  The determination unit 18 compares the measurement accuracy calculated by the measurement accuracy calculation unit 17 with the allowable value set by the parameter storage unit 13 and displays the determination result on the display unit 9. Therefore, the measurement accuracy and the determination result are displayed on the display unit 9 at the same time. In addition, the display unit 9 also displays an allowable value set in advance by the parameter input unit 14 along with the measurement accuracy and the determination result. Thus, the measurement accuracy, the determination result, and the allowable value are displayed on the display unit 9 and can be visually recognized at the same time, and the determination result (whether it is within the allowable range) obtained by the determination unit 18 is displayed on the display unit 9. Thus, even an operator who has no specialized knowledge or experience can easily verify whether the weighing of the weighing means 7 is correct.

  The control unit 8 delays the defect selection signal from the determination unit 18 by a preset delay time and outputs the signal to the sorter 5. When receiving the failure sorting signal from the control unit 8, the sorter 5 is driven for a preset operation time.

  The parameter input means 14 is for storing an allowable error or the like input by a key operation or another device (another inspection device on the carry-in line side, a line central control device, etc.) in the parameter storage means 13, and is a keyboard (not shown). And an external interface device.

  FIG. 3 is a display image diagram displayed on the display means, and FIG. 4 is a display image diagram according to another example displayed on the display means.

  The display means 9 includes a mode display unit 21, an operation procedure and determination result display unit 22, a normal quality amount display unit 23, a mass value display unit 24, an allowable value display unit 25, a weighing accuracy display unit 26, a statistical value display unit 27, A product type display unit 28 is provided. Further, the statistical value display unit 27 includes a count display unit 27a, a repeated statistical value (X-bar) display unit 27b representing bias, a standard deviation (S) display unit 27c as a repeated statistical value representing variation, and a maximum value-minimum. A value (R) display unit 27d, a maximum value (MAX) display unit 27e, and a minimum value (MIN) display unit 27f are provided.

  As shown in FIG. 4, the display unit 9 </ b> A may display each display unit shown in FIG. 3 in a simplified manner.

Next, the operation of the weighing device 1 will be described.
In the weighing device 1, an upper limit allowable value of the weighing accuracy is inputted in advance by the parameter input means 14. This allowable value is input as, for example, a JIS standard value. Moreover, the measurement accuracy is input by the parameter input unit 14 as an arbitrary value of 1 sigma to 6 sigma. Usually, the weighing accuracy is set to 3 sigma.
When the operation is started, a message indicating the operation procedure of, for example, “Please feed a normal product” is displayed on the operation procedure of the display means 9 and the determination result display unit 22.

  When the article W is carried into the weighing conveyor 3 from the upstream conveyor 2, a weighing signal from the weighing means 7 is sent to the statistical means 11. By repeating this measurement a plurality of times (about 30 to 60 times), the variation calculated by the variation calculation unit 15 and the bias calculated by the bias calculation unit 16 are sent to the measurement accuracy calculation unit 17.

  The weighing accuracy calculation means 17 calculates the weighing accuracy from the variation and the bias. That is, the weighing accuracy is obtained by weighing accuracy = variation + | bias |. The measurement accuracy calculated by the measurement accuracy calculation means 17 is sent to the determination means 18. The determination unit 18 compares the measurement accuracy calculated by the measurement accuracy calculation unit 17 with the allowable value set by the parameter storage unit 13 and displays the determination result on the display unit 9.

  The determination result is displayed with a comment such as “It is a normal product” on the operation procedure of the display means 9 and the determination result display unit 22, for example. At this time, the display means 9 includes weighing accuracy, determination result, allowable value, mass value, count, average value, standard deviation (repeated statistical value representing variation), maximum value-minimum value, maximum value, minimum value. Is also displayed.

  According to the weighing device according to the present embodiment, the statistical result calculated by the statistical unit 11 (repeated statistical value representing variation, repeated statistical value representing bias) and the upper limit of the weighing accuracy set by the parameter input unit 14 are set. Since the judgment means 18 for comparing with the allowable value to be expressed is provided and the judgment result obtained by the comparison of the judgment means 18 is displayed on the display means 9, even an operator who has no specialized knowledge or experience can easily verify. Is possible. As a result, verification workability can be improved and verification errors can be prevented.

1 is a block diagram showing a schematic configuration of a weighing device according to the present invention. FIG. 2 is a block diagram illustrating a more specific configuration example of the configuration illustrated in FIG. 1. It is a figure which shows the display image displayed on a display means. It is a figure which shows the display image by the other example displayed on a display means. It is a block diagram which shows schematic structure of the conventional weighing | measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Weighing device 3 ... Weighing conveyor 7 ... Measuring means 9 ... Display means 11 ... Statistical means 12 ... Parameter setting means 18 ... Judgment means W ... Article (object to be weighed)

Claims (5)

A weighing conveyor (3) for sequentially transporting the objects to be weighed, a weighing means (7) provided on the weighing conveyor for outputting a weighing value corresponding to the weight of the objects to be weighed (W), and weighing by the weighing means Statistical means (11) for statistically outputting values and outputting statistical values representing variation, display means (9) for displaying the measurement values and the statistical values, and parameter setting means (12) for setting parameters relating to measurement In a weighing device (1) comprising:
The statistical means calculates a repeated statistical value representing variation of repeated measured values when the same object is repeatedly measured, calculates a measurement accuracy of the weighing means based on the repeated statistical values, and the display means Is a weighing apparatus that displays the weighing accuracy of the weighing device calculated by the statistical device and the allowable value set by the parameter setting device and representing the upper limit of the weighing accuracy.   The statistical means further includes a bias calculating means (16) for calculating a repeated statistical value representing a bias of the repeated weighing value from the reference weight of the object to be weighed set by the parameter setting means and the repeated weighing value. The measurement accuracy calculation means (17) according to claim 1, further comprising: a measurement accuracy calculation means (17) for calculating a measurement accuracy of the measurement means based on a repetition statistics value representing the variation and a repetition statistics value representing the bias. Weighing device.   The parameter setting means selects a preset calculation formula for measuring accuracy of the weighing means for determining a margin with respect to the allowable value, and the statistical means measures the weighing means based on the calculation formula The weighing apparatus according to claim 1 or 2, wherein the accuracy is calculated.   The parameter setting means sets a coefficient for judging a margin for the allowable value, and the statistical means calculates the measurement accuracy of the measurement means based on the coefficient. 2. The weighing device according to 2.   A determination unit (18) for comparing the statistical result calculated by the statistical unit with the allowable value set by the parameter setting unit; and the determination result obtained by the comparison of the determination unit is displayed on the display unit. The weighing device according to claim 1, wherein the weighing device is displayed.