JPS6156926B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for weighing articles to be sorted and sorting them into appropriate quantity, light quantity, excessive quantity, etc. based on their weight.

Some of the above-mentioned sorting devices dynamically weigh the articles to be sorted by using a weighing conveyor as a weighing device that weighs the articles to be sorted while conveying them.
Since such sorting equipment uses a weighing conveyor, weighing errors may occur due to external disturbances such as shock loads caused by the shape of the articles to be sorted or the conveyance speed.
Errors were likely to occur in the selection results. Therefore, there was a method that added a correction device and operated by a worker to correct the dynamic weight value to a static weight value to prevent incorrect sorting, but it took a long time to operate and was accurate. It was not possible to make any necessary corrections.

An object of the present invention is to provide a sorting machine that can accurately prevent erroneous sorting with only simple operations.

The present invention will be explained below based on two illustrated embodiments. A first embodiment is shown in FIGS. 1 to 3. In FIG. 1, reference numeral 2 indicates a standard weight/appropriate amount number display section, 4 indicates an allowable upper limit deviation/excess amount number display section, and 6 indicates an allowable lower limit deviation/light weight number display section. Rotary switch 8 is used to switch between the weight display and the number of times display.
It is carried out by. Reference numerals 10, 12, and 14 indicate lamps, and the lamp 10 is turned on when the amount of articles to be sorted is appropriate, the lamp 12 is turned on when there is an excessive amount of the articles, and the lamp 14 is turned on when the articles are light. 16 is also a display section which, by switching the rotary switch 18, displays the weight of the article to be sorted, the standard weight, or the deviation of the weight of the article to be sorted from this standard weight. Reference numeral 20 denotes a bar graph display section, which consists of two rows of bar graph display tubes 22 and 24, upper and lower.The lower bar graph display tube 22 has upper and lower allowable deviations corresponding to the upper limit deviation and lower limit deviation on the left and right sides of the lower bar graph display tube 22, with the center as a reference. The bar is configured to display. Also, the upper bar graph display tube 24
is configured so that the bar from the leftmost bar to the bar corresponding to the deviation of the articles to be sorted lights up.

26 is a key switch, which switches rotary switch 8 to weight display, and selects S of this key switch.
When you press the key and operate the numeric key 28, the standard weight will be displayed on the standard weight/appropriate amount display section 2.
When you press the U key and operate the numeric key 28, the allowable upper limit deviation is displayed on the allowable upper limit deviation and overload count display section 4, and when you press the L key and operate the numeric key 28, the allowable lower limit deviation and overload count display section 6 is displayed. The allowable lower limit deviation is displayed. The displayed standard weight, allowable upper limit deviation, and allowable lower limit deviation are stored in the storage unit 32 via the arithmetic control unit 30 shown in FIG. 2 by pressing the _M1 key of the key switches.

In FIG. 2, reference numeral 34 denotes a weight detection section, which is provided on the belt conveyor and detects the dynamic weight value of the article to be weighed that is conveyed on the conveyor. This dynamic weight value is converted into a digital signal by an analog-to-digital conversion circuit (hereinafter referred to as an A/D conversion circuit) 36. Arithmetic control unit 30
After correcting this dynamic weight value to a static weight value as described later, the deviation from the static standard weight is calculated, and the deviation is compared with the static allowable upper limit deviation and allowable lower limit deviation, and overweight is determined. , is configured to sort to appropriate amount or light weight.

In addition, 38 is a correction/weighing mode changeover switch,
40 is a conveyor stop/start switch, 42
is the power switch. The _M2 key is used to store in the storage unit 32 the weight (static weight) of the articles to be sorted when the weighing conveyor is stopped in the correction mode.

FIG. 3 shows a schematic diagram of the correction circuit 44 included in the arithmetic control section 30. 46 is an integration circuit, A/
This is a circuit for integrating the digital dynamic metric values of the D conversion circuit 36, and 48 is a counting circuit for counting the number of integrations. 50 is a divider which divides the output of the integration circuit 46 by the output of the counting circuit 48 to calculate the average value of the dynamic measurement values. 52 is an arithmetic circuit that calculates the deviation between the output of the divider 50 and the static weight stored in the storage unit 32, or the ratio of the static weight to the output of the divider 50, and the deviation or ratio is stored in the storage unit. 32
is memorized. 54 is also an arithmetic circuit which calculates the absolute value of the deviation in the storage section 32 from the digital dynamic measurement value from the A/D conversion circuit 36 when the changeover switch 38 is switched to the weighing mode, and when this deviation is positive or zero. The difference is subtracted, and when this deviation is negative, it is added, or the ratio in the storage section 32 is multiplied by the digital dynamic metric value. The output of this arithmetic circuit 54 is
Excess amount, appropriate amount, or light amount is selected as described above.

The thus configured sorting machine operates as follows. Now, the stop/start changeover switch 40 is switched to the stop side to stop the weighing conveyor, and the correction/weighing mode changeover switch 38 is also switched to the correction mode side, and the storage unit 32 stores the static standard weight and static weight. It is assumed that the allowable upper limit deviation and allowable lower limit deviation are stored. In this state, a suitable article to be sorted is placed on the weighing conveyor, and the _M2 key is pressed to store the static weight converted into a digital signal W _S in the storage section 32. Next, start
The stop changeover switch 40 is switched to the starting side, the weighing conveyor is started, and the articles to be sorted whose static weights are stored are conveyed on the weighing conveyor n times, for example.
As a result, the integrating circuit 46 stores the integrated value of n dynamic measurement values, and the counting circuit 48 counts n. At this time, when the M ₂ key is pressed again, the divider 50 divides the output of the integrating circuit 46 by the output of the counting circuit 48 to calculate the average value W _D of the dynamic weight values. The arithmetic circuit 52 calculates the deviation W _C between this average value and the static weight W _S of the storage unit 32 or the ratio of the static weight to this average value K _C =W _S /W _D. This deviation W _C or ratio K _C is stored in the storage section 32.

The correction/weighing mode changeover switch 38 is switched to the weighing mode side, and a new article to be sorted is weighed on the weighing conveyor. At this time, the arithmetic circuit 54 outputs the deviation W
When _C is zero or positive, the absolute value of the deviation W _C is subtracted from the dynamic measurement value from the A/D conversion circuit 36, and when the deviation W _C is negative, the dynamic measurement value from the A/D conversion circuit 36 is subtracted. The dynamic metric value is corrected to the static metric value by adding the absolute value of the deviation _WC to , or by multiplying the dynamic metric value by the ratio _KC . The deviation between this correction value and the static standard weight is calculated, and this deviation is compared with the static allowable upper limit deviation and allowable lower limit deviation to determine whether the weight is excessive, appropriate, or lightweight. Note that when the ratio K _C is multiplied, there is no need to perform the correction again even if the article to be sorted is changed.

FIG. 4 shows a second embodiment, which is constructed in the same manner as the first embodiment except that a center value is determined by a circuit 55 instead of determining the average value of the dynamic measurement values. Equivalent parts are given the same reference numerals and their explanations will be omitted. This center value is determined by the n dynamic weight values obtained by weighing the articles to be sorted whose static weight is stored in the storage unit 32 n times on the weighing conveyor.
The calculation circuit 58 calculates and removes the maximum value among the n dynamic measurement values, and the remaining (n-
1) It is obtained by finding and removing the minimum value among the dynamic metric values, and then repeating this process to remove (n-1) dynamic metric values.

With these sorting machines, the dynamic weight value obtained by the weighing conveyor can be calculated by simply storing the static weight of the selected article and weighing the selected article any number of times on the weighing conveyor. Since the static weight value can be automatically and accurately corrected, and the static standard weight and the static allowable upper and lower limit deviations are used for sorting, erroneous sorting can be prevented.

In both of the above embodiments, the dynamic weighing value was corrected by the ratio K _C or the deviation W _C , but the same effect can be obtained by correcting the standard weight, the allowable upper limit deviation, and the allowable lower limit deviation to dynamic values. can get. Furthermore, although the configuration has been described in which the deviation between the weight value and the standard weight is determined and this is compared with the allowable upper limit deviation and the allowable lower limit deviation, a structure may be adopted in which the weight value is compared with the allowable upper limit weight and the allowable lower limit weight. Furthermore, although the static weight is stored in the storage unit 32 by pressing the _M2 key, instead of this, a device may be provided in the arithmetic control unit 30 that automatically stores the static weight in the storage unit 32 when the scale becomes stable. If the weight of the item is known, press numeric key 2.
8 may be operated to store it in the storage unit 32. In addition, although the configuration is such that the deviation W _C or the ratio K _C is calculated by pressing the _M2 key again, the calculation is performed when the weighing/correction mode changeover switch 38 is switched from the correction mode side to the weighing mode side. Alternatively, the static weight may be stored while the stop/start changeover switch 40 is switched to the stop side, and the calculation may be performed when the switch is switched to the start side. In addition, in the first example, all dynamic weight values were integrated and divided by the number of measurements to obtain the average value, but as in the second example, how many maximum and minimum values were calculated? The average value may be determined after removing the

[Brief explanation of the drawing]

FIG. 1 is a front view of a first embodiment of a sorting machine according to the present invention, FIG. 2 is a block diagram of the same embodiment, and FIG.
This figure is a block diagram showing a part of the arithmetic control section of the same embodiment, and FIG. 4 is a block diagram of the second embodiment. 30... Arithmetic control section, 32... Storage section, 34... Weight detection section, 44, 55... First arithmetic circuit, 52... Second arithmetic circuit, 54... Third arithmetic circuit.

Claims (1)

[Claims] 1 Comparing the weighing value of the article to be sorted with a reference weight or comparing the deviation of the weighing value of the article to be sorted from the standard weight with an allowable deviation, and sorting the article; In a sorting machine that performs dynamic weighing using a weighing conveyor and statically determining a comparison value consisting of only the above reference weight or the above standard weight and tolerance, any article to be sorted is weighed by the above weighing conveyor. a first arithmetic circuit that calculates an average value or a center value of the plurality of dynamic weighing values obtained based on the plurality of dynamic weighing values; a storage unit that stores the static weight of the arbitrary article to be sorted; and this static weight storage. a second arithmetic circuit that calculates the deviation between the stored value of the static weight storage section and the output of the first arithmetic circuit or the ratio of the stored value of the static weight storage section to the output of the first arithmetic circuit; A correction circuit comprising a third arithmetic circuit that calculates the dynamic weighing value from the weighing conveyor or the algebraic sum of the comparison value and the deviation or the multiplication value of one of the above values and the ratio and supplies it to the comparison circuit. A sorting machine characterized by being equipped with.