JP7513271B2 - Sorting machine - Google Patents

Description

The present invention relates to a sorting machine.

In recent years, vegetables have been grown in places all over Japan as an alternative to rice paddy cultivation. Taro in particular is suitable for cultivation in moist fields, so it has been converted to rice paddy cultivation. However, taro harvesting is almost entirely done by hand, and there is a strong demand for mechanization to reduce the labor required.

Although there are already machines that can remove mud while picking up onions, potatoes, etc., there are no machines that can remove mud while picking up taro. In conditions where there is a lot of mud contamination, such as when it is necessary to pick up small diameter tubers such as taro or when using in wet fields, it is necessary to improve the mud removal capacity of existing machines. Furthermore, taro in particular has irregular shapes such as spindle shapes and tubers with multiple tubers connected together, and devices that use mud removal screens are prone to clogging as they tend to get caught in the gaps in the mud removal screen and are difficult to roll, making it difficult to remove mud with existing machines.

In addition, taro is an agricultural crop in which child tubers branch out from parent tubers and then grandchild tubers branch out from the child tubers, but the size of the child and grandchild tubers is known to be significantly smaller than the parent tubers at harvest time. For example, it is known that in a certain variety of taro, the ratio of the minor axis of the child and grandchild tubers to the average minor axis of the parent tuber at harvest time is about 1/7 to 5/7. In this specification, the "minor axis" refers to the maximum length value when the length is measured at right angles to the major axis direction of the taro. However, the major axis refers to the length equivalent to the major axis of a spheroid when the taro is modeled after a spheroid.

As a technology related to conventional potato mud removal devices, Patent Document 1 discloses a technology that improves efficiency and reduces labor in removing soil clods, in which two rollers, one of which has a spiral projection on its peripheral surface and the other of which has a flat surface with no irregularities, roll in and crush soil clods while transporting the crops by the rolling rotation of the rollers.

Patent document 2 discloses a technology for a manual taro separation device that allows soil adhering to taro to fall from multiple wires.

Patent Document 3 discloses an earth discharge device that separates excavated soil, including boulders, excavated by the cutter head of a shield excavator into boulders and excavated soil including small-diameter gravel using a screen bar during transport, and discharges the boulders from a boulder discharge port and the excavated soil separately using a screw feeder.

JP 2004-242568 A Registered Utility Model No. 3138737 JP 2013-241740 A

In the two-shaft roller of Patent Document 1, the spiral protrusions transport agricultural products, but it is thought to be difficult to transport all the different sized tubers such as taro, including parent tubers, child tubers, and grandchild tubers, all at once. For example, to transport parent tubers, the height of the spiral protrusions would need to be about 1/3 the height of the parent tuber's short diameter, but as mentioned above, in the case of taro, the ratio of the short diameter of small tubers to that of large tubers is extremely small, at a minimum of about 1/7, so there is a concern that the small tubers will be removed from the gaps between the rollers along with the soil and sand.

In the method of Patent Document 2 in which soil falls through the gaps between multiple wires, even if one taro plant is separated and the parent tuber is removed by hand, the baby and grandchild tubers remain on the wires together with the soil, so manual assistance is required to drop the soil below the wires, which raises concerns about increased work.

In Patent Document 3, boulders are received by a screen bar, and the excavated soil, including small-diameter gravel that falls through the gaps in the screen bar, is transported by a screw feeder. The boulders received by the screen bar are intermittently discharged from the boulder discharge port, and continuous operation is not possible. The curved groove on the underside of the screw auger is intended to ensure that the soil is transported by the screw auger without any omissions.

In consideration of the above problems, the present invention provides a sorting machine that can efficiently sort taro, which has a significant difference in size, into large and small ones and remove mud.

In order to solve the above problems, according to the present invention, there is provided a sorting machine for sorting taro tubers by size, comprising a screw conveyor consisting of a pair of left and right screws which rotate inwardly towards each other when viewed from above, and a screen arranged close to the underside of the screw conveyor, with notches made in the longitudinal direction of the screws, and characterized in that when unsorted taro tubers are transported from the front end to the rear end of the screw conveyor while removing mud, taro tubers with larger short diameters are sorted onto the upper side of the screw conveyor and taro tubers with smaller short diameters are sorted onto the underside of the screw conveyor and above the screen.

The screw may be formed by providing a spiral groove in a cylindrical rod material, and may be configured so that the cross section of the spiral ridge in the longitudinal direction does not have any acute angles.

The screw may have a notch in the longitudinal direction.

The width of the gap between the opposing spiral grooves of the screw may be configured to be equal to the short diameter of the largest of the small-diameter taros. Alternatively, the width of the gap between the spiral grooves of the screw may be gradually increased from the front end to the rear end of the screw conveyor, and the width of the gap between the spiral grooves at the front end of the screw conveyor may be equal to the short diameter of the smallest of the small-diameter taros, and the width of the gap between the spiral grooves at the rear end of the screw conveyor may be equal to the short diameter of the largest of the small-diameter taros.

The screw conveyor may be a first screw conveyor, the screen may be a plurality of second screw conveyors, and the plurality of second screw conveyors may have left and right second screws each having a spiral groove formed in a cylindrical rod material, and the width of the gap between the opposing spiral grooves of the second screws may be configured to be smaller than the minor axis of the smallest of the small-diameter taros.

The present invention provides a sorting machine that can efficiently sort taro, which has significant size differences, into large and small varieties and remove mud.

1 is a diagram showing a schematic overview of a taro harvesting system according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing an outline of the positional relationship between a screw conveyor and a screen in the sorting machine according to the embodiment of the present invention. FIG. 2 is a schematic diagram showing an outline of taro sorting using a sorting machine according to the present embodiment. FIG. 2 is a cross-sectional view of a schematic diagram showing an outline of taro sorting by the sorting machine according to the present embodiment. FIG. 2 is a cross-sectional view of a schematic diagram showing an outline of taro sorting by the sorting machine according to the present embodiment. FIG. 13 is a schematic diagram showing an outline of a screw conveyor in a sorting machine according to a modified example. FIG. 13 is a schematic diagram showing an outline of a plurality of second screw conveyors in a sorting machine according to a modified example. FIG. 11 is a schematic diagram showing an outline of another example of a screw conveyor in the sorter according to the present embodiment. FIG. 11 is a schematic diagram showing an outline of another example of a screw conveyor in the sorter according to the present embodiment. FIG. 2 is a schematic diagram showing an outline of sorting of stuck taro using a sorting machine according to the present embodiment. FIG. 2 is a cross-sectional view of a schematic diagram showing an outline of sorting of bound taro using a sorting machine according to the present embodiment.

The following describes an embodiment of the present invention with reference to the drawings.

Figure 1 is a side view (Figure 1(a)) and a plan view (Figure 1(b)) that show a schematic overview of a taro harvesting system 1 according to this embodiment.

The taro harvesting system 1 according to this embodiment has a picker 3, a sorter 4, and a container car 5. The picker 3 is self-propelled and pulls the container car 5 behind it. The sorter 4 is attached to the picker 3 and moves integrally with the picker 3. In this specification, the direction forward in the direction of travel of the picker 3 (the direction of the bold arrow in Figure 1) is simply referred to as the forward direction, and the opposite direction, behind the direction of travel of the picker 3, is simply referred to as the rearward direction.

In this embodiment, the taro harvesting system 1 picks up taro A that has been dug up near the ground surface of the field by any taro digging device and stores it in a container vehicle 5. Any taro digging device separates some parent taro A from child and grandchild potatoes and digs them up to the ground surface, but does not completely separate the parent potato from the child and grandchild potatoes, and does not sort and store them. In the present invention, a sorting machine 4 is provided between the picker 3 and the container vehicle 5, so that the parent potato, which is taro A that has been dug up near the ground surface of the field, and the child and grandchild potatoes are sorted and separated and stored in the container vehicle 5.

The picker 3 has a crawler 10, a slat conveyor 12, a guide plate 13, a gauge arm 14, a gauge wheel 15, and a chute 16.

On both the left and right ends of the Picka 3, left and right crawlers 10 equipped with endless tracks are provided to facilitate maneuvering in wet fields. The left and right crawlers 10 are connected to a power source (not shown), and the left and right crawlers 10 are rotated using the driving force from the power source, making the Picka 3 self-propelled. A vehicle body is provided between the left and right crawlers 10 as the structure of the Picka 3, and all of the components of the Picka 3 are attached to the vehicle body.

In front of the picker 3, the front end of the slat conveyor 12 is buried to an arbitrary depth (cultivation depth), and the rear end of the slat conveyor 12 is extended to the rear of the picker 3. At the left end position forward of the front end of the slat conveyor 12, in the groove portion of the field ridge (hereinafter referred to as the ridge groove), a gauge wheel 15 is provided that runs along the ridge groove to keep the cultivation depth of the front end of the slat conveyor 12 constant.

The slat conveyor 12 has a configuration in which the ends of each of the multiple slats 12a are sandwiched between left and right conveyor chains (not shown), and the multiple slats 12a rotate integrally with the rotation of the conveyor chains. The direction of rotation is the direction in which the slats 12a move from the front to the rear of the picker 3 on the upper surface (conveying surface) of the slat conveyor 12. This allows the dug-up taro A that contacts the front end of the slat conveyor 12 to be picked up by placing it on the upper surface (conveying surface) of the slats 12a as the picker 3 moves forward. The taro A is also transported backward while placed on the conveying surface. The multiple slats 12a are provided so that there is a gap between them. By setting the width of the gap smaller than the short diameter of the taro A, the taro A does not fall, and only the mud and gravel attached to the taro A can be dropped.

The conveyor chain is connected to the power of picker 3 by gears and chains (not shown) and is driven to rotate.

The guide plate 13 is provided on the left side of the front end of the slat conveyor 12, and serves to guide the dug-up taro A located on the outside of the width of the slat conveyor 12 so that it can come into contact with the front end of the slat conveyor 12. For this reason, the guide plate 13 is provided so that its front end is located outside the width of the slat conveyor 12 and its rear end is adjacent to the left side of the front end of the slat conveyor 12.

The slat conveyor 12 is rotatably connected to the vehicle body 11 at its rear end 12b, and by changing the angle of the slat conveyor 12 through such rotation, the tilling depth at the front end of the slat conveyor 12 can be adjusted.

The angle of the slat conveyor 12 is changed using a gauge wheel 15 that contacts the furrow at the front left end of the front end of the slat conveyor 12 and a gauge arm 14 that connects the gauge wheel 15 to the front and rear ends of the slat conveyor 12.

Specifically, the gauge arm 14 has a front arm 14a, a rear arm 14b, and a cylinder 14c, with the front arm 14a connected to the gauge wheel 15, the rear arm 14b connected to the rear end side of the slat conveyor 12, and the cylinder 14c provided on the rear arm 14b connected to the front end side of the slat conveyor 12.

The gauge wheel 15 is in contact with the ground and supports the weight of the gauge arm 14 and the slat conveyor 12. The operator can adjust the angle by extending and retracting the cylinder 14c and adjusting the distance between the gauge arm 14 and the front end of the slat conveyor 12, thereby rotating the slat conveyor 12 around the rear end 12b of the slat conveyor 12.

A chute 16 is provided behind the picker 3 to transfer the picked up taro A to the sorter 4. The front end of the chute 16 is adjacent to the rear end of the slat conveyor 12, and the width of the chute 16 narrows toward the rear end of the chute 16, which is adjacent to the sorter 4.

The taro A picked up and transported by the picker 3 and arriving at the sorter 4 from the chute 16 has mud and gravel adhering to it, with the taro A having a large short diameter (hereafter referred to as large taro B) and the taro A having a small short diameter (hereafter referred to as small taro C). The sorter 4 removes the mud and gravel from the taro A (hereafter referred to as mud removal) and sorts the large taro B and the small taro C. Note that the large taro B is the taro A having a large short diameter, and may include, for example, a parent potato. The small potato C is the taro A having a small short diameter, and may include, for example, a child or grandchild potato that has branched off from the parent potato and grown, and the ratio of the short diameter to the average of the short diameter of the parent potato is about 1/7 to 5/7.

The sorting machine 4 has a screw conveyor 20, a screen 21, a pressure belt 22, a first chute 23, and a second chute 24. In this embodiment, two sorting machines 4 are provided in parallel in the left-right direction, but the number and arrangement are not limited to this example. In the following explanation, one of the two sorting machines 4 will be explained, but the other sorting machine 4 may be configured in the same way.

The front end of the screw conveyor 20 is located adjacent to the rear end of the chute 16. The screw conveyor 20 is composed of a left screw 30 and a right screw 31, which are connected to a power source so that they rotate inwardly when viewed from above. In this specification, when the screw conveyor 20 is viewed backward from the front side in the direction of travel of the picker 3, the left side is defined as the left screw 30 and the right side is defined as the right screw 31. The configuration and function of the sorting machine 4 will be described later.

The taro A transported from the chute 16 to the sorting machine 4 is transported on the top surface of the screw conveyor 20 (upward transport, described below) or transported between the screw conveyor 20 and the screen 21 (downward transport, described below). The taro A transported upward falls from the rear end of the screw conveyor 20 and passes through the first chute 23 into the first container 40 in the container car 5. The taro A transported downward falls from the rear end of the screen 21 and passes through the second chute 24 into the second container 41 in the container car 5. Thus, large and small taro A are sorted into the first container 40 or the second container 41 and collected.

The container car 5 has the first container 40 and the second container 41 placed on a trolley 42, and is towed by connecting the trolley 42 to the body 11 of the picker 3.

The screw conveyor 20 does not necessarily need to be inclined so that its rear end is higher than its front end as shown in FIG. 1, but in order to lift the picked-up taro A to the height of the inlets of the first container 40 and the second container 41 as in this embodiment, it is preferable to install it so that its rear end is higher than its front end. In this case, by providing a pressure belt 22, it is possible to prevent the taro A being transported upward from rolling from the rear end side to the front end side on the upper surface of the screw conveyor 20.

The pressure belt 22 is provided on the upper surface of the screw conveyor 20 so that the conveying surface of the screw conveyor 20 and the lower surface of the pressure belt 22 are approximately parallel. A plurality of pressure plates 50 are provided on the pressure belt 22 at regular intervals so as to be approximately perpendicular to the belt portion 51, which is an endless belt. The length of the belt portion 51 is approximately the same as the length of the screw conveyor 20, and rotating ends 52 are provided at the front and rear ends of the belt portion 51. The belt portion 51 rotates as the rotating ends 52 rotate, and the pressure plates 50 provided on the belt portion 51 rotate. The rotation direction is the same as the conveying direction of the taro A transported by the screw conveyor 20, and the speed is also approximately the same.

The rotating end 52 may be connected to the power of the picker 3 by gears, sprockets, and chains (not shown) to rotate it.

Side panels (not shown) may be provided at both ends of the sorting machine 4 to prevent the taro A being transported from falling off both ends of the sorting machine's screw conveyor 20. In this case, it is preferable to provide the above-mentioned vertical side panels with a small gap between them and the screw conveyor 20 so that the taro does not fall off the sides of both sides of the two sorting machines 4.

There are no particular limitations on how the sorter 4 is attached to the picker 3 or how the container car 5 is connected to it. For example, the sorter 4 may be attached to the body 11 of the picker 3 via a support frame 54. The container car 5 may be connected to the body 11 of the picker 3 via a towing rod 55.

Next, the sorting machine 4 according to this embodiment will be described with reference to FIG. 2. FIG. 2 is a schematic diagram showing an outline of the positional relationship between the screw conveyor 20 and the screen 21 in the sorting machine 4 according to this embodiment. FIG. 2(a) is a top view of the screw conveyor 20 and the screen 21, FIG. 2(b) is a side view, and FIG. 2(c) is a bottom view. However, for ease of viewing, the first chute 23 and the second chute 24 are omitted from the bottom view of FIG. 2(c). Also, FIG. 2(d) is a cross-sectional view taken in the direction of the arrow at the X-X position in FIG. 2(a).

In the screw conveyor 20, the left screw 30 is a cylindrical rod material with a left-handed (S-wound) spiral groove 60, which rotates clockwise when viewed from the front end of the screw conveyor 20. The right screw 31 is a cylindrical rod material with a right-handed (Z-wound) spiral groove 60, which rotates counterclockwise when viewed from the front end of the screw conveyor 20. The groove shape of the spiral groove 60 may be, for example, an arc. A groove shape of an arc refers to a case where the spiral groove 60 is in the shape of an arc on a cross section of the screw cut parallel to the rotation axis of the screw.

The left screw 30 and the right screw 31 are arranged so that the positions of their spiral grooves 60 are aligned. Therefore, a wide first gap 61 is formed where the spiral grooves 60 face each other.

The screw conveyor 20 may be connected to the power of the picker 3 by gears, sprockets, and chains (not shown) and driven to rotate.

A screen 21 is provided on the underside of the screw conveyor 20 along the length of the left screw 30 and the right screw 31. The screen 21 has a number of screen bars 62, each of which is provided from the front end of the screw conveyor 20 to just before the rear end of the screw conveyor 20. However, just before the rear end may be, for example, a length just before the front-to-rear width of the second chute 24.

The screen 21 is spaced a predetermined distance away from the screw conveyor 20 so as not to come into contact with it. This distance will be described later.

Next, the upward and downward conveyance in the sorting machine 4 according to this embodiment will be described in detail with reference to Figures 3 to 5. In addition, the function of separating the large potatoes B and the small potatoes C that are stuck together will be described.

Figure 3 is a schematic diagram showing an outline of the mechanism by which taro A is sorted into large potatoes B and small potatoes C by a sorting machine 4. However, both are side views of the sorting machine 4, and Figures 3(a) to (c) are in chronological order as taro A is transported over time.

Unsorted taro A is fed from the rear end of the chute 16 and placed at the front end of the top side of the screw conveyor 20, straddling the left screw 30 and the right screw 31. The taro A fed to the front end of the screw conveyor 20 is then pushed by the helical ridge 63 (the part of the outer periphery of the cylindrical rod that does not have the helical groove 60) as the left screw 30 and the right screw 31 rotate, and is transported from the front end to the rear end of the screw conveyor 20.

When large potatoes B are placed on the front end of the screw conveyor 20, the large potatoes B are transported on the upper surface of the screw conveyor 20 from the front end to the rear end by the rotation of the left screw 30 and the right screw 31. This transport on the upper surface of the screw conveyor 20 is called upward transport. During upward transport, the large potatoes B do not fall from the first gap 61 because their short diameter is larger than the width of the first gap 61 as shown in Figure 4. Note that Figure 4 is a cross-sectional view taken in the direction of the arrow at the Y-Y position in Figure 3(b).

When small potatoes C are placed on the front end of the screw conveyor 20, as shown in FIG. 5, in addition to mud and gravel, small potatoes C with a shorter diameter smaller than the width of the first gap 61 fall from the first gap 61 of the left screw 30 and the right screw 31. In this case, the small potatoes C can be transported so as to remain in the first gap 61, or they can be transported by either dropping onto the screen 21 without staying in the first gap 61 and being transported on the screen 21. Note that FIG. 5 is a cross-sectional view seen in the direction of the arrow at the Z-Z position in FIG. 3(b). The mud and gravel that fall from the first gap 61 fall toward the ground from the second gap 64, which is the gap between the multiple screen bars 62 in the screen 21, but the small potatoes C stay between the underside of the screw conveyor 20 and the screen 21 and do not fall from the second gap 64. The small potatoes C remaining in the first gap 61 and the small potatoes C between the bottom surface of the screw conveyor 20 and the screen 21 are pushed by the helical ridges 63 as the left screw 30 and the right screw 31 rotate, and are transported on the screen 21 from the front end to the rear end of the screw conveyor 20. The transport in the first gap 61 or the bottom surface of the screw conveyor 20 is called downward transport.

When the large potatoes B transported upward reach the rear end of the screw conveyor 20, they fall into the first chute 23, pass through the first chute 23 and are stored in the first container 40. Meanwhile, the small potatoes C transported downward fall into the second chute 24 (Figure 3(c)), pass through the second chute 24 and are stored in the second container 41.

The outer diameter of the left screw 30 and the right screw 31 (referring to the outer diameter of the cylindrical rod), the pitch of the spiral groove 60, the depth of the spiral groove 60, the width of the spiral ridge 63, the width of the first gap 61, the distance between the spiral ridge 63 and the screen 21, the width of the second gap 64, etc. can be determined from the short diameter of the taro A to be sorted as small potatoes C.

As mentioned above, in a certain variety of taro A, the short diameter of small potatoes C is at most 5/7 of that of large potatoes B. For this reason, large potatoes B and small potatoes C are clearly distinguished in size. Therefore, the largest short diameter of small potatoes C is set as the classification point, and the width of the first gap 61 is set to a length equal to the classification point. In this case, the classification point refers to a threshold value at which taro A with a short diameter equal to or less than that length is selected as small potatoes C.

In addition, in order to make the width of the first gap 61 equal to the above-mentioned classification point, the outer diameter of the left screw 30 and the right screw 31, the pitch of the spiral groove 60, the depth of the spiral groove 60, the width of the helical ridge 63, the width of the gap between the left screw 30 and the right screw 31, etc. are appropriately determined.

Specifically, for example, the width of the first gap 61 may be set to a value slightly larger than the short diameter of the largest taro A to be selected as small potatoes C, so that the small potato with the largest short diameter can pass through the first gap 61 and fall.

Also, for example, the width of the second gap 64 may be set to a value slightly smaller than the short diameter of the smallest taro A to be selected as a small potato C, so that the small potato with the smallest short diameter does not fall through the second gap 64.

For example, the width of the first gap 61 may be made variable by making the distance between the rotation axes of the left screw 30 and the right screw 31 (axis distance) variable. In this case, the width of the first gap 61 can be changed based on the minor axis of the largest small potato C to be sorted by downward transport due to differences in variety, etc. The maximum changeable axis distance may be set so that the width of the first gap 61 is equal to the diameter of the circumscribing circle of the spiral groove 60. In this case, the cross-sectional shape of the spiral groove 60 is an arc, and the first gap 61 is close to a circle, making it easy for potatoes smaller than the width of the first gap 61 to pass through.

The rotational speed of the left screw 30 and the right screw 31 may be set to a rotational speed that allows the screw conveyor 20 to smoothly transport the taro A, and the speed at which the screw conveyor 20 transports the taro A may be set to be faster than the working speed at which the picker 3 picks up the taro A.

Furthermore, by making the width of the gap between the spiral ridge 63 and the screen 21 and the width of the second gap 64 smaller than the length of the smallest short diameter of the small potatoes C, the smallest small potatoes C can be transported downward without falling through the second gap 64.

In this case, the width of the gap between the spiral ridge 63 and each screen bar 62 may be less than half the short diameter of the smallest of the small potatoes C. This allows the small potatoes C on the screen 21 to enter the inside of the spiral groove 60 regardless of their size, and the small potatoes C can be transported downward between the spiral groove 60 and the screen bar 62 without falling from the gap between the spiral ridge 63 and the screen bar 62 to the front end side of the screw conveyor 20.

Also, one screen bar 62a may be provided below the screw conveyor 20 and in the center between the left screw 30 and the right screw 31. This is preferable because the distance between the screen bar 62a provided in the center and the left screw 30 and the right screw 31 can be made small, which allows for good downward transport.

When the side panels are provided, the number of screen bars 62 is such that they do not come into contact with the vertical side panels, and they are positioned to cover the lower half of the screw conveyor so that small potatoes do not fall through the gap between the screen bars 62 and the side panels. The number and diameter of the screen bars are such that small potatoes do not fall through the gap between the screen bars 62 and the side panels.

In the above embodiment, the taro A is separated into two types, taro A that falls through the first gap 61 of a predetermined size and taro A that does not fall, but this is not limited to this. Depending on the modified example of the present invention, the type and stage of separation can be changed as appropriate.

Below, a modified example of the present invention will be described with reference to Figures 6 to 11.

Figure 6 is a schematic diagram showing the configuration for drawing small potatoes C passing through the first gap into a first gap 61 that further separates the small potatoes C into several pieces according to their size in the screw conveyor 20 of this modified example.

As shown in FIG. 6, in this modified example, the spiral groove 60 is provided so that it gradually becomes deeper and wider from the front end to the rear end of the left screw 30 and the right screw 31. As a result, the width of the first gap 61 is narrower at the front end side of the screw conveyor 20 and wider at the rear end side.

By setting the width of the first gap 61 in this manner, the relatively small first gap 61 formed by the spiral groove 60 on the front end side of the screw conveyor 20 allows small potatoes C with a relatively small short diameter to fall through the first gap 61, and the relatively large first gap 61 formed by the spiral groove 60 on the rear end side of the screw conveyor 20 allows small potatoes C with a relatively large short diameter to fall through the first gap 61. This makes it possible to further sort small potatoes C with varying sizes into multiple stages based on size.

In this case, the width of the first gap 61 on the front end side should be approximately the smallest of the short diameters of the small potatoes C, and the width of the first gap 61 on the rear end side should be the classification point.

In this modified example, the small potatoes that pass through the first gaps, each of which is of a different size, may be dropped into the corresponding individual containers by a chute for sorting, or may be rotated and transported by a second screw conveyor (described below), and further de-mudified while being dropped into the corresponding individual containers for sorting.

In this embodiment, the small potatoes C that fall through the first gap 61 are received by the screen 21, and the small potatoes C are transported downward between the underside of the screw conveyor 20 and the screen 21. However, unlike the upward transport in which the rotation of the left screw 30 and the right screw 31 efficiently removes mud while transporting the small potatoes C, in the downward transport, although transportation is possible, there is a concern that mud removal is insufficient simply by transporting the small potatoes C by sliding them over the multiple screen bars 62.

As shown in FIG. 7, a modified example for resolving the above concerns has a first screw conveyor 67 as the screw conveyor 20 in the above embodiment, and a plurality of second screw conveyors 70 as the plurality of screen bars 62 of the screen 21 in the above embodiment. The second screw conveyor 70 will be described below with reference to FIG. 7.

Figure 7 is a schematic diagram showing an outline of the sorting machine 4 in the above modified example, which has a first screw conveyor 67 and multiple second screw conveyors 70. Figure 7(a) is a top view of the first screw conveyor 67 and the second screw conveyor 70, Figure 7(b) is a side view, and Figure 7(c) is a bottom view. However, for ease of viewing, the first chute 23 and the second chute 24 are omitted from the bottom view of Figure 7(c). Also, Figure 7(d) is a cross-sectional view seen in the direction of the arrow at the W-W position in Figure 7(a).

The first screw conveyor 67 has a configuration similar to that of the screw conveyor 20 in the above embodiment, and has a first left screw 68 and a first right screw 69. The first left screw 68 and the first right screw 69 rotate inwardly toward each other, similar to the left screw 30 and the right screw 31 in the screw conveyor 20, and transport the taro A from the front end to the rear end as they rotate. Otherwise, the configuration and function of the first screw conveyor 67 are the same as those of the screw conveyor 20 described above, and a description thereof will be omitted.

The multiple second screw conveyors 70 are provided on the underside of the first screw conveyor 67, and each has a second left screw 71 and a second right screw 72. The second left screw 71 and the second right screw 72 rotate inwardly toward each other, similar to the left screw 30 and the right screw 31 in the screw conveyor 20, and transport the small potatoes C from the front end to the rear end as they rotate.

The second left screw 71 and the second right screw 72 are generally cylindrical rods with left-handed (S-wound) and right-handed (Z-wound) spiral grooves 73, similar to the left screw 30 and the right screw 31 in the screw conveyor 20. The second left screw 71 and the second right screw 72 are arranged so that the positions of the spiral grooves 60 of each screw are aligned. Therefore, a wide third gap 74 is formed where the spiral grooves 60 of each screw face each other.

The second screw conveyor 70 may be connected to the power of the picker 3 by gears, sprockets, and chains (not shown) and driven to rotate.

As the second left screw 71 and the second right screw 72 rotate, the small potatoes C are transported while rolling and the mud is removed. The mud and gravel are drawn into the third gap 74 and fall to the ground. At this time, by making the width of the third gap 74 smaller than the smallest minor axis of the small potatoes C, only the mud and gravel fall from the third gap 74, and the small potatoes C do not fall but remain on the upper surface of the second screw conveyor 70.

Then, the large potatoes B transported upward on the first screw conveyor 67 fall into the first chute at the rear end of the first screw conveyor 67 and are stored in the first container 40. The small potatoes C transported downward on the second screw conveyor 70 fall into the second chute and are stored in the second container 41.

In the above modified example, multiple second screw conveyors 70 are provided, but this is not limited to this. For example, one second screw conveyor 70 may be provided below the first left screw 68 and the first right screw 69 below the first screw conveyor 67, and a screen bar 62 may be provided to form a third gap 74 between these second screw conveyors 70 and the screen bar 62. In the above case, punching metal or a net that forms the third gap 74 may be used instead of the screen bar 62. In addition, the number and arrangement of the second screw conveyor 70, the screen bars 62, the punching metal, etc. may be changed.

The above-described configuration allows for the separation and removal of mud between large potatoes B and small potatoes C. However, there is a concern that mud adhering to the surface may not be sufficiently removed simply by transporting taro A while it rotates on the screw conveyor 20.

To resolve the above concerns and further promote the removal of mud from the taro A transported by the sorting machine 4, it is preferable to provide unevenness on the spiral ridge 63 and spiral groove 60 of the screw conveyor 20. The above-mentioned configuration will be explained using Figures 8 and 9. Note that, although the screw conveyor 20 will be explained below, the same effect can be obtained by adopting a similar configuration for the first screw conveyor 67 and the second screw conveyor 70 in the above modified example.

Figures 8 and 9 are schematic diagrams showing an example of a configuration for further promoting the removal of mud from taro A transported in the sorting machine 4 in the screw conveyor 20 according to the above embodiment. The configuration of the sorting machine 4 other than the screw conveyor 20 is the same as described above, so it is not shown.

In the examples of Figures 8 and 9, the mud adhering to the surface of the taro A is separated from the taro A by providing unevenness to the spiral ridge 63 and the spiral groove 60. In both Figures 8 and 9, multiple notches 80 are provided in the length direction of the left screw 30 and the right screw 31. Note that dimensions other than the notches 80 can be determined in the same manner as above.

In FIG. 8, the helical ridge 63 has a notch 80 in the length direction of the left screw 30 and the right screw 31 so that the cross section is roughly gear-shaped. Note that FIG. 8(a) is a top view of such a screw conveyor 20, and FIG. 8(b) is a cross section seen in the direction of the arrow at the S-S position in FIG. 8(a). The notch 80 makes it easier for the roughly gear-shaped uneven portion of the helical ridge 63 to mesh with the unevenness of the surface of the taro A, which has no fixed shape. In other words, by having the roughly gear-shaped unevenness of the helical ridge 63, the unevenness scrapes off mud and the like adhering to the potatoes being transported as it rotates, making it possible to more effectively separate mud adhering to the surface of the taro A.

In addition, the spiral ridge 63 has roughly gear-shaped projections and recesses, which are expected to scrape away dirt and other debris from the bond between the large potatoes B and the small potatoes C as they rotate, weakening the bond.

In Figure 9, in addition to the spiral ridge 63, a notch 80 is also provided in the spiral groove 60. Note that Figure 9(a) is a top view of such a screw conveyor 20, and Figure 9(b) is a cross-sectional view taken in the direction of the arrow at position T-T in Figure 9(a). By providing a notch 80 in the spiral groove 60 as well, the unevenness of the screw conveyor 20 caused by the notch 80 can be more easily meshed with the unevenness of the surface of the taro A, and mud adhering to the surface of the small potatoes C passing through the first gap 61 can also be scraped off.

When taro A is picked up by the picker 3, the parent tuber and the baby tubers that have branched off and grown from the parent tuber may be attached to each other.

In FIG. 10, the bound potatoes D, which is formed by binding large potatoes B and small potatoes C, are transported from the front end to the rear end on the upper surface of the screw conveyor 20, while the small potatoes C of the bound potatoes D are drawn into the first gap 61 (FIG. 10(b), FIG. 11). Note that FIG. 11 is a cross-sectional view seen in the direction of the arrow at the position U-U in FIG. 10(b). The small potatoes C drawn into the first gap 61 are peeled off from the binding with the large potatoes B by the rotation of the left screw 30 and the right screw 31, and finally fall to the lower surface of the screw conveyor 20, and are then transported downward (FIG. 10(c)). On the other hand, the large potatoes B, whose short diameter is larger than the width of the first gap 61, do not fall through the first gap 61, but remain on the upper surface of the screw conveyor 20 and are transported upward (FIG. 10(c)). As a result, the bound potatoes D are sorted into large potatoes B and small potatoes C.

In the sorting machine 4 according to this embodiment, the left screw 30 and the right screw 31 are configured with a spiral groove 60 on a cylindrical rod, so that the spiral ridge 63 does not have an acute angle in the cross section in the longitudinal direction, but consists only of obtuse angles. With this configuration, it is possible to prevent the taro A that falls from the chute 16 onto the upper surface of the screw conveyor 20 from being damaged by the acute angle of the spiral ridge 63.

In addition to the above, as an example of the configuration of the screw conveyor 20, the left screw 30 and the right screw 31 may be formed so that the periphery of a core material such as metal or resin provided along the rotation axis is covered with rubber, which is an elastic member. It is preferable that the above-mentioned core material is covered with rubber, which is an elastic member, even at the deepest position of the spiral groove 60 so that it is not exposed on the surface of the left screw 30 and the right screw 31. In addition, it is preferable to provide the spiral groove 60 with a shallow depth and a narrow width so that the first gap 61 is shorter than the classification point. By configuring in this way, since the left screw 30 and the right screw 31 are formed of rubber, the spiral groove 60 deforms when drawing in the small potatoes C, making it possible to draw in small potatoes C larger than the width of the first gap 61. As a result, it is possible to efficiently draw in small potatoes C having a short diameter shorter than the classification point into the first gap 61, and small potatoes C of the size of the classification point can also be drawn into the first gap 61.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an example. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

For example, in the above embodiment, the picker 3 has power and tows the container car 5, but the present invention is not limited to such an example. For example, the picker 3 may not have power for self-propulsion, and the picker 3 and container car 5 may be towed by any tractor. In this case, the screw conveyor 20, which is connected to the power of the picker 3 and rotates, may be connected to the power of the tractor.

Using the sorting machine 4 as described above, taro A, which has a significant difference in size, can be demudged and efficiently sorted into large potatoes B and small potatoes C.

This invention can be used in a taro sorting machine.

A Taro B Large potato C Small potato D Sticky potato 1 Taro harvesting system 3 Picker 4 Sorting machine 5 Container car 10 Crawler 12 Slat conveyor 13 Guide plate 14 Gauge arm 15 Gauge wheel 16 Chute 20 Screw conveyor 21 Screen 22 Presser belt 23 First chute 24 Second chute 30 Left screw 31 Right screw 40 First container 41 Second container 42 Cart 50 Presser plate 51 Belt section 52 Rotating end 54 Support frame 55 Towing rod 60 Spiral groove 61 First gap 62 Screen bar 63 Spiral ridge 64 Second gap 67 First screw conveyor 68 First left screw 69 First right screw 70 Second screw conveyor 71 Second left screw 72 Second right screw 73 Spiral groove 74 Third gap

Claims (5)

A sorting machine for sorting taro by size,
A screw conveyor including a pair of left and right screws rotating inwardly with respect to each other when viewed from above, and a screen provided on the lower surface of the screw conveyor,
A notch is provided in the length direction of the screw,
When unsorted taro is transported from the front end to the rear end of the screw conveyor while removing mud,
Large diameter taros are sorted onto the upper side of the screw conveyor,
The method is characterized in that small diameter taro is sorted on the lower surface side of the screw conveyor and above the screen.
Sorting machine. The sorting machine according to claim 1, characterized in that the screw is a cylindrical rod with a spiral groove and has no acute angle in the cross section of the spiral thread in the longitudinal direction. The sorting machine of claim 2, characterized in that the width of the gap between the opposing spiral grooves of the screw is equal to the minor axis of the largest of the small-diameter taros. The sorting machine of claim 2, characterized in that the width of the gap between the spiral grooves of the screws is gradually increased from the front end to the rear end of the screw conveyor, the width of the gap between the spiral grooves at the front end of the screw conveyor is equal to the short diameter of the smallest of the small-diameter taros, and the width of the gap between the spiral grooves at the rear end of the screw conveyor is equal to the short diameter of the largest of the small-diameter taros. The screw conveyor is a first screw conveyor,
The screen is a plurality of second screw conveyors,
The plurality of second screw conveyors have left and right second screws each having a spiral groove formed on a cylindrical rod material, and the width of the gap between the opposing spiral grooves of the second screws is smaller than the minor axis of the smallest of the small diameter taros. The sorting machine according to any one of claims 1 to 4, characterized in that:

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