JPS6260948B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a multi-item weight sorting device that simultaneously performs weight sorting and type sorting of a wide variety of articles having different weights and shapes.

In the quality inspection process of a manufacturing factory, a standard weight standard is set for each manufactured item, and items heavier than the standard value and items lighter than the standard value are rejected as defective products. The multi-item weight sorting device, which sorts the weight of a wide variety of articles that are successively brought in in random order by a conveyor or the like, as described above,
It mainly consists of a conveyor for carrying in goods, a weighing machine equipped with a weighing conveyor for placing the goods carried in by this carrying-in conveyor, and a sorting machine adjacent to this weighing machine. Further, near the end of the carry-in conveyor, a product type detector is provided to detect the type of the product from the mark (for example, bar code), shape (for example, height), etc. of the product to be carried into the weighing conveyor of the weighing device. Then, the weight of the item carried onto the weighing conveyor is measured by the weighing device, and the measured weight value is compared with the reference value of the item specified by the type detector. Then, when the measured items are carried from the weighing conveyor to an adjacent sorting machine, the sorting machine determines whether the measured weight value is greater than the reference value or When the value is smaller than the standard value, the item is selected and excluded.

However, the multi-item weight sorting apparatus configured as described above has the following problems.

In other words, since the time at which an item is carried onto the weighing conveyor by the carry-in conveyor is generally irregular, a sensor such as a phototube or a limit switch is provided at a reference position on the weighing conveyor or the carry-in conveyor so that the tip of the article is above the The output value of the weighing device after a certain period of time has elapsed after passing through the reference position is taken as the measured weight value of the item. Similarly, the sorting machine
The item is driven after a predetermined period of time, which is separately determined, has elapsed since the item passed through the reference position.

However, when measuring the weight of an item with a scale, after the tip of the item is placed on the tip of the weighing conveyor, and after the entire item is placed on the weighing conveyor, the output value of the scale is stable and accurate. The time required for this to appear varies depending on the shape, weight, etc. of the item. In the case of an article that is short in the transport direction, the above-mentioned time is short, and conversely, in the case of an article that is long in the transport direction, the above-mentioned time is long. Therefore, in an apparatus in which the above-mentioned time is uniformly set short regardless of the shape of the article, there is a problem that the measured weight value of a long article cannot be accurately determined. Moreover, if the above-mentioned time is set too long, there is a problem that when measuring short items, the entire item comes off the weighing conveyor before the measurement time is reached. As a result, since the weight value of the item cannot be determined accurately, there is a risk that the sorting accuracy of the entire apparatus will be reduced.

In addition, the operating time of the sorting machine is set uniformly regardless of the shape of the item, so depending on the item,
In some cases, an external force is forcibly applied when the item is not set in the correct position, and in that case, there is a risk that the item may be damaged and there is a problem that a smooth sorting operation cannot be performed.

The present invention has been made based on these circumstances, and its purpose is to measure the weight of each type of item at different measurement timings and to sort the items at different sorting timings. Then,
To provide a multi-product weight sorting device which can improve sorting speed and weight measurement accuracy, perform smooth sorting operations, improve the sorting accuracy of the entire device, and improve reliability.

The present invention will be explained below using the drawings. FIG. 1 is a schematic configuration diagram showing a multi-product weight sorting device according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes an incoming conveyor for conveying articles 2, and a weighing device 3 is installed adjacent to this incoming conveyor 1 in the conveying direction. This weighing device 3 has a built-in weighing conveyor 4 on which the articles 2 carried in by the carrying-in conveyor 1 are placed. Further, an unloading conveyor 5 is installed adjacent to this weighing device 3 for unloading the weighed items, and an air jet type or pusher type sorting machine 6 is installed on the unloading conveyor 5 near the weighing device 3 side. is installed. Further, the carry-in conveyor 1 determines the mark (for example, barcode), shape (for example, height), etc. of the article 2 to be carried onto the weighing conveyor 4.
A product type detector 7 is provided to detect the type of product, and a sensor 8 such as a phototube that is activated when the tip of the product 2 passes is installed at an intermediate position between the carry-in conveyor 1 as a reference position and the weighing conveyor 4. has been done.

FIG. 2 shows a control block diagram of the multi-item weight sorting apparatus having the above configuration. In the figure, 9 is a CPU (central processing unit) that performs various information processing and controls each device.
I/O (input/output interface) 11, ROM
(read only memory) 12, RAM (random access memory) 13, arithmetic unit 14, and timer 15 are connected. The I/O 11 also includes an encoding circuit 16 connected to the product type detector 7, a time detector 17 connected to the sensor 8, and an A/D connected to an amplifier 18 for amplifying the output signal of the measuring instrument 3. The converter 19, a drive circuit 21 of a display 20 that displays the calculation results in the calculation section 14, a drive circuit 22 of the sorter 6, and the like are connected.

The ROM 12 stores fixed data such as programs for setting the operating procedure of this device. Further, as shown in FIG. 3, the RAM 13 stores data on, for example, N types of items 2 to be sorted by this sorter. That is, the reference value W _s , the upper limit value W _a , and the lower limit value W of the weight of the item 2
_s , measurement indicating the time from the time when the item 2 detected by the sensor 8 and the time detector 17 passes the reference position until the time when the A/D converter 19 reads the output signal of the reference clock scale 3. The sorting machine 6 operates from the delay time T ₁ and the above reference time, and the above article 2
The sorting delay time T ₂ indicates the time until the time of sorting.
are stored in order of number (address) of item 2.

The arithmetic unit 14 operates on the A/D according to a command sent from the CPU 9 via the control bus 23.
The weight value of item 2 input from converter 19 is
It compares the upper limit value W _a and the lower limit value W _b in the RAM 13, calculates the difference from the reference value W _s , and displays the difference on the display 20. Further, the timer 15 measures a measurement delay time T ₁ and a selection delay time T ₂ from the reference time. The driving circuit 22 drives the sorting machine 6 for sorting based on the comparison result of the arithmetic unit 14, that is, the judgment of lightness and excess amount, after the elapse of sorting delay time T ₂ from the reference time according to a command from the CPU 9.

Next, the operation of the multi-item weight sorter configured as described above will be explained. First, when the item 2 is carried in by the carry-in conveyor 1, the type of the item 2 is detected by the type detector 7. This detection signal is converted by the encoding circuit 16 into a digital code signal determined for each item and inputted to the I/O 11.
The CPU 9 uses the code signal input from the I/O 11 to input each data W _a ,
Read W _b , W _s , T ₁ , T ₂ , send W _a , W _b , W _s to the calculation unit 14 via the data bus 10 ,
T ₁ and T ₂ are transferred to the timer 15 via the data bus 10. Next, the tip of item 2 reaches the reference position,
When the sensor 8 is activated, the time detector 17 transmits the trigger pulse at this time, that is, the reference time, to the I/O 11.
Enter. When the above reference time is input, the CPU 9 inputs the measurement delay time previously input to the timer 15.
T ₁ , commands to start measuring the sorting delay time T ₂ . As shown in Figure 4a, when the item 2 is placed on the weighing conveyor 4 from the carry-in conveyor 1 and moves in the direction of the arrow on the weighing conveyor 4, the output value of the weighing device 3 will be as shown in the A characteristic in Figure 4b. The weight gradually increases and eventually stabilizes at the correct weight value. This output signal is amplified by an amplifier 18 and input to an A/D converter 19. When the timer 15 finishes measuring the measurement delay time _T1 , the A/D converter 19 converts the above output signal into an A/D signal according to a command from the CPU 9 and outputs it to the I/O1.
Enter 1. The weight value of the item 2 input to the I/O 11 is transferred to the calculation unit 14 via the data bus 10, and the calculation unit 14 calculates the upper limit value W _a and the lower limit value W _b that were previously transferred from the RAM 13. be compared. If it is smaller than the lower limit value W _b , it is determined that it is lightweight, and if it is larger than the upper limit value W _a , it is determined that it is overweight. Furthermore, the difference between the weight value and the reference value _Ws is also calculated. The light weight/overweight determination signal is input to the drive circuit 22 of the sorter 6 via the data bus 10 and I/O 11. On the other hand, the above difference is similarly input to the drive circuit 21 of the display 20 via the data bus 10 and I/O 11, and is displayed on the display 20 electronically.

Furthermore, when the article 2 is moved from the weighing conveyor 4 to the unloading conveyor 5 and reaches the central position of the sorting machine 6, and the timer 15 finishes measuring the sorting delay time _T2 , the drive circuit 22 is activated by a command from the CPU 9. The sorting machine 6 is driven to sort based on the light weight/overweight determination signal inputted from the calculation unit 14. That is, if the item 2 is light or overweight, the item 2 is removed from the carry-out conveyor 5, and is transported to the next process by the carry-out conveyor 5 only if it is of standard weight.

With the multi-item weight sorting device having such a configuration, it is possible to set the measurement delay time T ₁ and the sorting delay time T ₂ to optimal values depending on the shape and weight of the article 2. For example, in FIG. 4a, the No. 1 item 2 with a shape shown by a solid line and the No. 2 item 2a with a longer shape than the item 2 shown with a broken line are placed on the weighing conveyor 4 by the carry-in conveyor 1. Then, the outputs of the measuring instrument 3 for the item 2 and the item 2a have the A and B characteristics shown in FIG. 4b, respectively. In other words, the characteristic A of the No. 1 item 2 is stable at approximately the center position of the weighing conveyor 4, but the characteristic A of the No. 1 item 2 is stable.
Since a is long, characteristic B becomes stable when its tip reaches the end of the weighing conveyor 4. Therefore, in this case, as shown in FIG. 3, the measurement delay time T ₁ ' of the No. 2 item 2a is the measurement delay time of the No.
If it is set longer than T ₁ , measurement results with stable characteristics can be obtained for both No. 1 and No. 2 items 2 and 2a. As a result, the weight value of the item 2 can always be accurately determined regardless of the shape and weight of the item, so it is possible to improve the sorting speed and accuracy of the entire apparatus.

In addition, when the items 2 and 2a of No. 1 and No. 2 are sorted by the sorter 6, the center position of the items 2 and 2a is located at the sorter 6 from the installation position of the sensor 8, where the items 2 and 2a are the reference position. The time it takes for the No. 2 item 2a to arrive at the center position is longer than the No. 1 item 2. Therefore, as shown in FIG. 3, if the sorting delay time T ₂ ' for No. 2 item 2a is set longer than the sorting delay time T ₂ for No. 1 item 2, No. 1 and
Since both No. 2 items 2 and 2a are sorted while being properly set at the center of the sorting machine 6, the items are smoothly sorted without being damaged. As a result, the reliability of the entire device can be improved.

As explained above, according to the present invention, the accuracy of weight measurement is improved by measuring the weight in a stable state after a period of time that differs depending on the type of item has elapsed from the reference time when the item passes the reference position. Therefore, it is possible to improve the sorting accuracy of the entire apparatus. In addition, since the items are properly set in the sorting machine and sorted after a different amount of time has elapsed from the above reference time for each type of item, it is possible to prevent damage to the items and improve the reliability of the entire device. be able to.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a multi-item weight sorting device according to an embodiment of the present invention, FIG. 2 is a control block diagram of the sorting device, and FIG. 3 is a storage arrangement diagram in the storage section of the sorting device. FIGS. 4a and 4b are explanatory diagrams for explaining the effects of the sorting device, respectively. 1... Carrying in conveyor, 2... Goods, 3... Weighing device, 4... Weighing conveyor, 5... Outgoing conveyor,
6...Sorting machine, 7...Type detector, 8...Sensor, 9...CPU, 13...RAM (storage unit), 14
... Arithmetic unit, 15 ... Timer, 16 ... Encoding circuit, 17 ... Reference time detector, 19 ... A/D converter, 20 ... Display device, 21 ... Drive circuit, 22
...Drive circuit.

Claims (1)

[Claims] 1. After transferring multiple types of items from a carry-in conveyor to a scale equipped with a weighing conveyor and measuring the weight of the items with the scale, the weight of the items is measured according to a reference weight value preset for each type. A multi-item weight sorting device for sorting the articles by a sorter, comprising a type detector for detecting the type of the articles carried in by the carry-in conveyor, and a reference position near the tip of the weighing conveyor. a reference time detector for detecting that the item has passed; and the reference weight;
a storage unit that stores a measurement delay time from the reference time to the time of weight measurement in the weighing device and a sorting delay time from the reference time to the time of sorting in the sorting machine in correspondence with the type of article; weight measuring means for detecting a weight value signal output from the weighing instrument when the measurement delay time has elapsed from time; and the reference stored in the storage unit corresponding to the type detected by the product type detector. a calculation unit that reads out a weight value and compares it with the detected weight value to determine whether the item is light or overweight; and based on the determination, when the sorting delay time has elapsed from the reference time, the sorting machine A multi-product weight sorting device characterized by comprising: a drive circuit that drives sorting;