JPS6324425B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a sorting device for removing foreign substances such as rocks mixed in root vegetables such as beets and yams that are conveyed by a conveyor or the like.

[Prior art and its problems]

Conventionally, there are devices of this type that use visual sensors and devices that use electromagnetic waves, but even though the color is almost the same, they vary in size, and because they are transported in a lump, they cannot be used in large quantities. It is almost impossible to sort out foreign substances mixed in root vegetables in a short time. There is also a known sorting device that uses the difference in specific gravity between root vegetables and foreign substances, but since this requires soaking in water, if you leave the vegetables for a while after purchase, they may germinate or rot. There is a drawback. Similarly, in the case of sorting by water jet using the difference in specific gravity, there are disadvantages in that an enormous amount of running cost and equipment space are required due to the amount of water and the storage space for root vegetables.

[Purpose of the invention]

This invention was made in view of these points,
To provide a sorting device capable of simply, quickly, and accurately sorting out foreign substances mixed in root vegetables.

[Key points of the invention]

In order to separate foreign substances from objects to be sorted including root vegetables and foreign substances, there is provided a conveyance means for conveying the objects to be sorted, and a means for conveying the objects to be sorted, and the objects to be sorted which are arranged with a step relative to the conveyance means and naturally fall from the conveyance means. A colliding plate member, a detection means for detecting a vibration frequency generated based on the collision, and a determination means for determining whether or not a foreign object is present in the target object from the frequency distribution of the detected vibration. , and performs selection based on the determination result.

[Embodiments of the invention]

FIG. 1 is an external configuration diagram showing an embodiment of the present invention;
FIG. 2 is a side view showing a specific example of the mechanism, and FIG. 3 is an explanatory diagram showing how the sensor is attached.

As shown in FIG. 1, the sorting device according to the present invention is roughly divided into a mechanism section consisting of conveyors 3 ₁ to 3 ₃ , a vibration plate 4, a sorting damper 5 and a partition plate 6, and a judgment/control section 7. be done. Furthermore, as shown in FIG. 2, the mechanism section is provided with a sensor 10, an air cylinder 12, a switching solenoid valve 13, an air compressor 14, and the like. In Figure 1, 1 indicates root vegetables such as beets or potatoes, and 2
is a foreign object such as a stone.

The operation will be explained below with reference to FIG. The figure shows an example in which the diaphragm 4 also serves as a sorting damper.

The mixture of root vegetables 1 and foreign matter 2 is transferred to conveyor 3 ₁
, and naturally falls onto the diaphragm 4 arranged with steps. As a result, an impact or impact sound is generated between the root vegetable or foreign object and the diaphragm.
It has been confirmed that the frequency distribution of this impact vibration or impact sound differs from each other due to the difference in the elastic modulus of the root vegetable and the foreign object, so the difference in this vibration or frequency distribution is detected via a predetermined sensor 10. Then, the determination/control unit 7 performs predetermined arithmetic processing to discriminate between root vegetables and foreign substances. As a result, when it is determined that it is a foreign object, the determination/control unit 7 outputs a control signal at a predetermined timing and the switching solenoid valve 13 is operated.
Air from 4 is given to the air cylinder 12 via the solenoid valve 13, and the air cylinder 12 is operated.
As a result, the diaphragm 4, which also functions as a sorting damper, is driven and rotates in the direction of arrow A, causing the foreign matter to fall onto the foreign matter conveyor ₃₂ . In addition, for root vegetables, the diaphragm 4 and the partition plate 6
It falls over the root vegetable conveyor 3 ₃ side.

In these embodiments, well-known vibration sensors such as a vibration accelerometer, vibration velocity meter, and vibration level meter, or acoustic sensors such as a microphone are used as means for detecting vibrations or impact sounds caused by impact. The sensor is not limited to this, and various sensors similar to this can be used. Note that FIG. 3A shows an example using a vibration meter, and FIG. 3B shows an example using a microphone.

In addition, in these embodiments, apart from the case where the root vegetables or foreign objects are arranged one by one and transported at a predetermined interval, when they are transported in large quantities as a lump, Both root vegetables and foreign matter may coexist in the sorting damper 5, and the root vegetables may also fall onto the foreign matter conveyor ₃₂ . Therefore, in order to perform a large amount of sorting in a short period of time, it is necessary to carry out two types of sorting, primary sorting and secondary sorting, as shown in Figure 4.
We perform heavy selection to ensure accuracy. Note that FIG. 4 is a configuration diagram showing an example of such a case.

In the figure, 3 ₄ to 3 ₈ are conveyors, 4 _1
46 is a diaphragm, ₅₁ to ₅₆ are sorting dampers, 21 is a truck for transporting root vegetables, and 22 is an alignment device, which is an example in which the diaphragm and the sorting damper are provided separately.

Root vegetables containing foreign substances such as stones are transferred by a truck 21 to a conveyor ₃₄ equipped with a soil removal mechanism (sieve, etc.).
Pebbles, etc. are removed. The removed soil, pebbles, etc.
While being collected by the truck 21 via the transport conveyors ₃₅ , ₃₆ , the remaining root vegetables etc. are collected by the vibrating plates ₄₁ to ₄₅ and the sorting dampers ₅₁ to ₅₅ in the same way as in the case of FIG. Next, sorted and foreign matter conveyor 3 ₆
drop a foreign object into the At this stage, it is expected that root vegetables are still mixed in, so the sorting device 2
2, they are arranged one by one at a predetermined interval and subjected to secondary sorting using a diaphragm 4 ₆ and a sorting damper 5 ₆ arranged at the end of the conveyor 3 ₆ .
The foreign matter is collected onto the truck 21 via the conveyor ₃₈ . As a result, soil, pebbles and foreign matter are collected on the truck 21, and only root vegetables are sorted on the conveyor ₃₇ . Note that, if necessary, a plurality of diaphragms and sorting dampers can be provided on the conveyor ₃₆ side.

5A to 5D are block diagrams showing each embodiment of the determination/control section, and FIGS. 6A to 6D are explanatory diagrams illustrating the sensor output and its determination operation.

For example, it has been confirmed that when a vibrational sound generated between a root vegetable or a foreign object and a diaphragm is detected using a vibration accelerometer, its frequency characteristics are expressed as shown in FIGS. 6A to 6D. That is, (a) Case of only root vegetables Because root vegetables have a higher elastic modulus than stones, etc., the peak of impact sound appears only in the reduction of the frequency band, and the output in the middle and high ranges is small. The waveform in this case is shown as X in A of FIGS. 6A-6D.

(b) In the case of foreign objects Foreign objects such as stones have a small elastic modulus, so the impact sound produces a large output over the entire frequency range. This case is shown as Y in FIGS. 6A to 6D.

(c) When root vegetables and foreign substances coexist, the waveform (a) and (b) are superimposed, and the waveforms from 6A to
It is shown as Z in Figure 6C.

By examining the sensor output, it is possible to determine whether foreign matter is present.

Figure 5A shows an example of this.
The control section includes an amplifier 71, a filter 72, and an integrator 7.
3, a comparator 74, a timing adjuster 75, an output relay 76, a setting device 77, etc.

That is, the output from the sensor is first passed through the amplifier 7.
1 and a predetermined frequency by a filter 72.
Components below f ₁ are removed. Therefore, filter 72 in this case is a low cut filter. The integrator 73 integrates frequency components higher than a predetermined frequency, and the comparator 74 compares the integrated value with a predetermined set value given from the setter 77. If the integrated value exceeds this set value, it is determined that a foreign object is present. It is assumed that it has been mixed in. As this relationship is clear by referring to Figure 6A, in the case of only root vegetables,
As shown in Figure A, the integral value S ₁ of the component with frequency f ₁ or higher is:
Since it is smaller than the integral value S ₁ in cases B and C that contain at least foreign matter, the set value K ₁ by the setting device 77 is
By appropriately selecting , it is possible to determine whether foreign matter is mixed in. Furthermore, when it is determined that foreign matter is mixed in, the output relay 76 is activated at a predetermined timing by the timing adjuster 75 shown in FIG. 5A, and the solenoid valve explained in FIG. 2 is driven. be. This timing is appropriately determined based on the conveyance speed of the conveyor, the time from detection on the diaphragm to arrival at the sorting damper, and the like.

The feature shown in FIG. 5B is that the sensor output is amplified and integrated as is. In other words, as is clear from FIG. 6B, the value obtained by simply integrating the sensor output, that is, the area S ₀
There is a clear difference between the case of only root vegetables as shown in A in the same figure, and the cases as shown in B and C of the same figure that contain at least foreign substances, so it is possible to make a distinction by selecting the setting value appropriately. can. By doing so, the filter can be made unnecessary and the circuit can be simplified.

What is shown in FIG. 5C includes two types of filters (a low-pass filter 72 and a high-pass filter 72).
2'), an arithmetic unit 78, and an AND gate 79 are provided. That is, as is clear from FIG. 6C, the relationship between the integral value S ₁ above the predetermined frequency f ₁ and the integral value S ₂ below it is similar to that for root vegetables only, as shown in A in the same figure. If S ₁ < S ₂
On the other hand, in the case of B and C in the same figure, which contain at least foreign matter, the method focuses on the point where S ₁ > S ₂ and determines the ratio, S ₂ /S ₁ , and uses a low-pass filter. 72 and the integrator 73, and the output S ₂ obtained through the high-pass filter 72' and the integrator 7
Based on the output S ₁ obtained through 3', the calculation unit 78 calculates the ratio S ₂ /S ₁ , compares the result with a predetermined set value, and if it is less than the predetermined value, it is determined that there is a foreign object. It is something to do. At this time, the comparator 74' detects whether the instantaneous value of the sensor output exceeds the base value, and only when it exceeds the base value, outputs a predetermined signal to the AND gate 79 to make the above judgment. Enable output. By doing so, malfunctions due to noise or the like can be avoided. Note that the output of the AND gate 79 in FIG. 5C is given to a timing adjuster, etc., as in FIGS. 5A and 5B, but illustration is omitted here.

The embodiment shown in FIG. 5D is characterized in that a bandpass filter is used as the filter. This is clear from Figure 6D,
The integral value S ₁₁ of the component between frequencies f ₁ and f ₂ is also different in size between the case of only root vegetables as shown in Figure A and the case where at least foreign matter is present as shown in Figure B. Therefore, the determination can be made by setting a predetermined set value _K2 as shown in FIG. Note that although the timing adjuster and the like are omitted in this case as well, they are provided in the same way. Moreover, although the case where a vibration accelerometer is used has been described above, the determination can be made in exactly the same manner when an acoustic sensor is used.

〔Effect of the invention〕

According to this invention, by examining the frequency distribution of vibrations or impact sounds caused by the collision between root vegetables or foreign objects and the plate member, it is possible to determine whether or not at least foreign objects are included. This makes it possible to easily, quickly, and accurately sort out foreign substances mixed in a product. Therefore, as a buyer of root vegetables, it is not only possible to purchase high-quality root vegetables that do not contain foreign substances such as stones, but also
There is no need for processing work to remove foreign matter, and it is possible to eliminate problems such as having trouble finding a place to store foreign matter. Furthermore, the percentage of foreign substances in root vegetables (which is said to be over 10% in some cases), which was previously negotiated between producers and buyers based on visual inspection.
This eliminates the need for determination work, which also allows for labor savings.

[Brief explanation of the drawing]

FIG. 1 is an external configuration diagram showing an embodiment of the present invention;
Fig. 2 is a side view showing a specific example of the mechanism, Fig. 3 is an explanatory view showing how the sensor is attached, and Fig. 4 is a side view showing a specific example of the mechanism.
Layout diagram showing the heavy sorting system, Nos. 5A to 5D
The figure is a block diagram showing each embodiment of the judgment/control section.
6A to 6D are explanatory diagrams for explaining the sensor output waveform and its determination operation. Explanation of symbols 1... Root vegetables, 2... Foreign matter, 3 ₁ to 3 ₈ ... Conveyor, 4, _{4 1} to 4 ₆ ... Vibration plate, 5, 5 ₁ to 5 ₆ ...
Sorting damper, 6... Partition plate, 7... Judgment/control unit, 1
0...Sensor, 12...Air cylinder, 13...Switching solenoid valve, 14...Air compressor, 21...Truck, 22...Alignment device, 71...Amplifier, 72,7
2'...Filter, 73, 73'...Integrator, 74,7
4'... Comparator, 75... Timing adjuster, 76...
Output relay, 77... Setting device, 78... Arithmetic unit, 79
…andgate.

Claims (1)

[Scope of Claims] 1. In order to separate foreign substances from objects to be sorted including root vegetables and foreign objects, a conveyance means for conveying the objects to be sorted; A plate-like member with which the falling object to be sorted collides with, a detection means for detecting a vibration frequency generated based on the collision, and a detection means for detecting whether or not foreign matter is present in the object from the frequency distribution of the detected vibration. What is claimed is: 1. A device for sorting out foreign substances mixed in root vegetables, comprising: a judging means for making a judgment; and carrying out sorting based on the judgment result.