CN112167043A

CN112167043A - Plant holder and plant cultivation system

Info

Publication number: CN112167043A
Application number: CN202010602984.6A
Authority: CN
Inventors: 水品晃彦; 山本武
Original assignee: Yaskawa Electric Corp
Current assignee: Yaskawa Electric Corp
Priority date: 2019-07-03
Filing date: 2020-06-29
Publication date: 2021-01-05
Anticipated expiration: 2040-06-29
Also published as: CN112167043B; JP6880518B2; JP2021007376A

Abstract

A plant holder and a plant cultivation system. Ensuring the mobility of the plant holding device and improving the growth function of the plant. The plant cultivation system comprises: a plant holding tool (3) for holding a plant (2) to be cultivated; a rail section (40) configured to support the plurality of plant holders (3) so as to be movable in the conveyance direction by means of a rail support surface (45); and a water tank (47) which is disposed below the rail (40), is open at the top, and stores a culture solution (48) therein, wherein the plant holding tool (3) comprises: a holding cylinder part (32) which holds a plant (2) by an inner diameter part (39) taking the vertical direction as the axial direction; and a main body part (31) which supports the retainer cylinder part (32), wherein a lower end opening part (39d) of the retainer cylinder part (32) protrudes below a retainer supporting surface (38) which supports the main body part (31).

Description

Plant holder and plant cultivation system

Technical Field

The disclosed embodiments relate to a plant holding tool and a plant cultivation system.

Background

For example, patent document 1 describes a plant cultivation system including: the plant to be cultivated is held by a holding tool, and the holding tool is moved along the rail for a predetermined period of time to grow the plant. In this plant cultivation system, a nutrient solution is stored in a water tank disposed below the track, and the roots of the plants held by the holding tool are absorbed by the nutrient solution, thereby promoting growth.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2017/042891

However, since the culture medium filled in the hole of the holder is easily dried, the culture medium needs to be absorbed by contacting with a nutrient solution during sowing or during seedling raising. On the other hand, in order to allow the holder to smoothly slide while being supported by the rail, the nutrient solution should be prevented from being immersed in the contact portion between the main body of the holder and the rail.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide a plant holding device and a plant cultivation system capable of improving a plant growth function while ensuring a movement performance of the plant holding device.

Means for solving the problems

In order to solve the above problem, according to an aspect of the present invention, there is applied a plant cultivation system including: a plant holding tool for holding a plant to be cultivated; a rail portion configured to support the plurality of plant holders by a rail support surface so as to be movable in a conveying direction; and a water tank section which is disposed below the rail section, has an open upper end, and stores a culture solution therein, the plant holding tool including: a holding cylinder portion that holds the plant by an inner diameter portion having a vertical direction as an axial direction; and a main body portion that supports the retainer tube portion, wherein a lower end opening of the retainer tube portion protrudes downward beyond a retainer support surface that supports the main body portion.

Further, according to another aspect of the present invention, there is applied a plant holding appliance having: a holding cylinder portion that holds a plant by an inner diameter portion having a vertical direction as an axial direction; and a main body portion that supports the retainer tube portion, wherein a lower end opening of the retainer tube portion protrudes downward beyond a retainer support surface that supports the main body portion.

Effects of the invention

According to the present invention, the movement performance of the plant holding device can be ensured, and the growth function of the plant can be improved.

Drawings

Fig. 1 is a system block diagram showing a schematic configuration of the entire plant cultivation system according to the embodiment.

Fig. 2 is a perspective view showing an example of a stacked cultivation shelf.

Fig. 3 is an explanatory view showing an example of arrangement of the rails in each of the stacked cultivation shelves.

Fig. 4 is an explanatory view showing an example of arrangement of the light sources in the respective stacked cultivation shelves.

Fig. 5 is a perspective view showing an example of the structure of the robot.

Fig. 6 is a perspective view showing an example of the structure of the hand.

Fig. 7 is a perspective view showing an example of the structure of the plant holding tool.

Fig. 8 (a) is a left-right direction orthogonal cross section viewed in the direction of arrows VIIIa to VIIIa in fig. 7 (a), and fig. 8 (b) is a front-rear direction orthogonal cross section viewed in the direction of arrows VIIIb to VIIIb in fig. 7 (a).

Fig. 9 is a cross-sectional view showing an example of the structure of the rail in a state where the plant holding fixture is supported.

Fig. 10 is a vertical cross-sectional view of the retainer tube portion with a portion a in fig. 8 enlarged.

Fig. 11 is a view for explaining the growth process of the plant and the function of the inner diameter portion of the retainer tube portion during the sowing period and the seedling period.

Fig. 12 is a right-left orthogonal cross-sectional view of an end portion of a rail.

Fig. 13 (a) is a front-rear direction orthogonal cross-sectional view viewed from arrows XIIIa to XIIIa in fig. 12, and fig. 13 (b) is a front-rear direction orthogonal cross-sectional view viewed from arrows XIIIb to XIIIb in fig. 12.

Fig. 14 is a side view of the plant holder in which rectangular and mountain-shaped convex portions and concave portions are formed at both ends in the conveying direction of the main body.

Description of the reference symbols

1 plant cultivation system

2 plants

3 plant holding tool

4 track

5 laminated cultivation shelf

5a cultivation shelf

6 transfer robot

7 carry-in conveyor

8 carry-out conveyor

15 light source

21 hand

31 main body part

32 retainer cylinder portion

33 guide taper part

34 guide plate part

35 support part

36 maximum width direction dimension portion

37 flat surface

38 holding implement bearing surface

39 inner diameter part

39a upper end opening part

39b straight tube part

39c small diameter part (Small mouth part)

39d lower end opening part

39e chamfered part

40 track part

45 track bearing surface

47 water tank part

47c Water tank wall

48 culture solution

50 culture medium

Detailed Description

An embodiment will be described below with reference to the drawings. In the following, for convenience of explanation of the structure of the plant cultivation system, the directions such as up, down, left, right, front, and rear shown in the drawings may be collectively defined and used as appropriate. However, the positional relationship of the respective structures of the plant cultivation system is not limited.

<1. construction of plant cultivation System >

An example of the overall configuration of the plant cultivation system 1 according to the present embodiment will be described with reference to fig. 1 to 4. In fig. 1, in order to avoid complication of the drawing, only the entire configuration of the system is schematically shown, and the detailed configuration of each part is simplified and schematically shown.

As shown in fig. 1 and 2, the plant cultivation system 1 is a system including: a plant 2 to be cultivated is held by a plant holder 3, and the plant holder 3 is moved along a rail 4 for a predetermined period of time to grow the plant. The plant cultivation system 1 includes a stacked cultivation shelf 5, a transfer robot 6, a carry-in conveyor 7, a carry-out conveyor 8, and a plurality of plant holders 3.

(1-1. shelf for stacked cultivation)

In the stacked cultivation shelf 5, a plurality of (8 in this example) cultivation shelf 5a are arranged in a manner that a plurality of layers are stacked in the vertical direction. The "vertical direction" does not need to be a strict vertical direction, and may be a substantial vertical direction. Therefore, the "vertical direction" also includes a direction slightly inclined with respect to the vertical direction. The stacking direction of the cultivation shelves 5a of the stacked cultivation shelves 5 is not limited to the vertical direction, and may be a direction inclined at a predetermined angle with respect to the vertical direction.

Each of the cultivation shelves 5a is provided with a plurality of rails 4 extending horizontally in the front-rear direction. The "front-rear direction" in the present embodiment is a flowing direction (conveying direction) of the plants 2 on each cultivation shelf 5a, and is also a longitudinal direction or an extending direction of the rail 4. In addition, the "horizontal direction" does not need to be a strictly horizontal direction as long as it is a substantially horizontal direction. Therefore, a direction slightly inclined with respect to the horizontal direction is also included. The plurality of rails 4 are provided side by side in the left-right direction on the respective cultivation shelves 5a, and the rails 4 are arranged substantially in parallel. In addition, the "left-right direction" in the present embodiment is a direction orthogonal to the above-described up-down direction and front-rear direction.

The detailed structure will be described later, but the rail 4 supports the plurality of plant holders 3 so as to be movable in the longitudinal direction. Then, the plant holding fixture 3 is supplied to the rail 4 from one side in the front-rear direction, and thereby the other supported plant holding fixtures 3 are pushed to the other side in the front-rear direction and are slid.

The number of the cultivation shelves 5a in the stacked cultivation shelf 5 is not particularly limited, but in the present embodiment, a case of 8 layers will be described as an example. For convenience of explanation, the tier of the cultivation shelf 5a on which the cultivation shelf 5 is stacked is referred to as "tier a" for the lowest tier, tier B for the highest tier, tiers 2 to 5 from the top, and tiers 6 and 7 from the top. That is, as shown in fig. 1 to 4, the a-tier has 1 cultivation shelf 5a, the B-tier has 1 cultivation shelf 5a, the C-tier has 4 cultivation shelves 5a, and the D-tier has 2 cultivation shelves 5 a. In the example shown in fig. 3, a relatively large number (8 in the illustrated example) of rails 4 are provided on the cultivation shelves 5a on level a. The cultivation shelves 5a on the level B are provided with a smaller number (6 in the illustrated example) of rails 4 than the level a. The cultivation shelves 5a on level C are provided with a smaller number (4 in this example) of rails 4 than the number of levels B. The cultivation shelves 5a of the D-level are provided with a smaller number (3 in this example) of rails 4 than the number of the C-level.

(1-2. order of conveyance)

Next, an example of a carrying procedure of the plant holder 3 and the plant 2 in the plant cultivation system 1 will be described. In this example, the carrying-in conveyor 7 carries in and supplies the plant holder 3 (details will be described later) from the rear side of the layer a by a stacker not shown, and the plant holder 3 holds the plant 2 in a state in which the seed is sown and germinated. The carrying-out conveyor 8 carries out the plant holding tool 3 holding the plant 2 in a sufficiently grown state from the rear side of the cultivation shelf 5a of each of the D layers.

Fig. 1 and 3 show the direction of conveyance of the plant holding tool 3 and the plant 2 on each cultivation shelf 5 a. In fig. 1, broken-line arrows indicate the direction of conveyance of the plant holding tool 3 and the plant 2 on each cultivation shelf 5 a. Note that, in fig. 3, reference numeral 101 denotes a direction in which the plant holder 3 and the plant 2 are conveyed from the front side to the rear side in the front-rear direction, and reference numeral 102 denotes a direction in which the plant holder 3 and the plant 2 are conveyed from the rear side to the front side in the opposite direction. As shown in fig. 1 and 3, the plant holder 3 and the plant 2 are transported on the rails 4 from the rear side to the front side on level a. On level B, the plant holding fixture 3 and the plant 2 are transported from the front side to the rear side on the rails 4. In the layer C, the plant holder 3 and the plant 2 are transported from the rear side to the front side on each rail 4 in each layer. In level D, each level carries the plant holding fixture 3 and the plant 2 from the front side toward the rear side on each rail 4.

The transfer robot 6 located on the front side of the stacked cultivation shelf 5 performs ascending transfer of the plant holders 3 and plants 2 from the a-level to the B-level and descending transfer of the plant holders 3 and plants 2 from the C-level to the D-level. At this time, the front transfer robot 6 performs horizontal distribution and vertical distribution between the C-level and D-level layers having different numbers of layers. The transfer robot 6 located on the rear side of the stacked cultivation shelf 5 performs horizontal transfer of the plant holders 3 and plants 2 from the carry-in conveyor 7 to the level a, downward transfer of the plant holders 3 and plants 2 from the level B to the level C, and collective transfer of the plant holders 3 and plants 2 from the level D to the carry-out conveyor 8. At this time, the rear transfer robot 6 performs the horizontal distribution, and also performs the vertical distribution between the B-level and the C-level at different levels.

As shown in fig. 4, a plurality of light sources 15 are provided above the cultivation shelves 5a of the stacked cultivation shelves 5, and the plurality of light sources 15 are used to irradiate the leaves 2b (see fig. 9 described later) of the plant 2 with light. The light sources 15 are provided on the lower surface of the support plate 11 so as to extend in the left-right direction, and the support plate 11 is provided above the cultivation shelves 5 a. The light sources 15 are arranged at predetermined intervals in the front-rear direction. The light source 15 is not particularly limited, but for example, an LED or a fluorescent lamp is used to promote photosynthesis of plants.

In the above conveyance path, the track pitch in the left-right direction gradually increases as the conveyance proceeds in the order of layer a → layer B → layer C → layer D. Thus, at the stage of raising the plant 2 whose entire size is smaller than that of the plant holder 3, the plant can be densely planted in the layer a having the narrowest track pitch, and then transported in the order of the layer B → the layer C → the layer D having the wider track pitch. That is, the arrangement interval can be increased in accordance with the stage in which the entire plant 2 grows gradually, and so-called permanent planting in which the plant 2 cultivation area can be effectively utilized with respect to the installation area of the entire stacked cultivation shelf 5 can be realized.

<2 > transfer robot

Next, an example of the structure of the transfer robot 6 will be described with reference to fig. 5 and 6. In fig. 5 and 6, the transfer robot 6 is shown in a three-dimensional manner in front of the stacked cultivation shelf 5, and the X-axis positive direction corresponds to the right, the X-axis negative direction corresponds to the left, the Y-axis positive direction corresponds to the rear, the Y-axis negative direction corresponds to the front, the Z-axis positive direction corresponds to the upper, and the Z-axis negative direction corresponds to the lower. Note that, the same configuration is applied to the transfer robot 6 disposed on the rear side of the stacked cultivation shelf 5, except that the positive and negative directions of the X axis and the Y axis are reversed, and therefore, the illustration thereof is omitted.

(2-1. integral Structure)

The transfer robot 6 takes out the plant holder 3 and the plant 2 from the end of one rail 4 and transfers them, and pushes them into the end of the other rail 4 and supplies them. As shown in fig. 5, the transfer robot 6 includes a base 16, a gate-shaped support frame 17 provided on the base 16, an actuator 30 provided on the support frame 17, and a hand 21.

The support frame 17 includes: a pair of support columns 17a provided on the base 16 along the Z-axis direction so as to face each other in the X-axis direction; and a substantially horizontal beam 17b that is erected along the X-axis direction at the upper ends of the pair of support columns 17 a.

The actuator 30 has an X-axis unit 18, a Z-axis unit 19, and a Y-axis unit 20. The X-axis unit 18 has a beam 18a, a slider 18b, and an X-axis motor 18 c. The beam 18a is erected substantially horizontally in the X-axis direction between the pair of support columns 17 a. The slider 18b is supported by the beam 18a so as to be movable in the X-axis direction. The X-axis motor 18c is attached to the left end of the beam 18a, and drives the slider 18b in the X-axis direction via a chain, not shown, attached to the slider 18 b.

The Z-axis unit 19 has a beam 19a, a slider 19b, and a Z-axis motor 19 c. The upper end of the beam 19a is supported by the beam 17b to be movable in the X-axis direction, and the beam 19a is fixed to the slider 18 b. The slider 19b is supported by the beam 19a so as to be movable in the Z-axis direction. The Z-axis motor 19c is attached to the lower end of the beam 19a, and drives the slider 19b in the Z-axis direction via a chain, not shown, attached to the slider 19 b.

The Y-axis unit 20 has a beam 20a, a slider 20b, and a Y-axis motor 20 c. The slider 20b is fixed to the slider 19 b. The beam 20a is supported by the slider 20b to be movable in the Y-axis direction. The Y-axis motor 20c is attached to the front end of the beam 20a, and drives the slider 20b in the Y-axis direction via a chain, not shown, attached to the slider 20 b.

In the actuator 30, when the slider 18b is driven in the X-axis direction by the X-axis motor 18c, the beam 19a moves in the X-axis direction, and the beam 20a moves in the X-axis direction via the slider 19b and the slider 20 b. Further, when the slider 19b is driven in the Z-axis direction by the Z-axis motor 19c, the beam 20a moves in the Z-axis direction via the slider 19b and the slider 20 b. Further, when the slider 20b is driven in the Y-axis direction by the Y-axis motor 20c, the beam 20a moves in the Y-axis direction via the slider 20 b. In this way, the actuator 30 can move the beam 20a in three axial directions of the X axis, the Y axis, and the Z axis.

The hand 21 is attached to the rear end of the beam 20a of the actuator 30, and grips the plant holder 3. The actuator 30 moves the beam 20a in three axial directions, thereby enabling the hand 21 to move in three axial directions. That is, the actuator 30 moves the hand 21 in the front-rear direction (the longitudinal direction of the rail 4). The actuator 30 can move the hand 21 in 2 directions orthogonal to the front-rear direction and orthogonal to each other, that is, 2 directions, i.e., the left-right direction (the direction in which the rails 4 are arranged, which is also a substantially horizontal direction) and the up-down direction (the stacking direction of the cultivation shelves 5a, which is also a height direction).

(2-2. hand)

As shown in fig. 6, the hand 21 has a base 22, a pair of sliders 24, a pair of claw members 25, and a driving block 26. The pair of sliders 24 are slidably engaged with the pair of 2 rail members 23 along the extending direction of the pair of 2 rail members 23, and the pair of 2 rail members 23 are extended in the X-axis direction at the lower portion of the front surface of the base 22. The pair of claw members 25 are attached to the lower ends of the pair of sliders 24, respectively, and are arranged substantially parallel to the X-axis direction. The drive block 26 is provided at an upper front portion of the base 22 and incorporates a drive mechanism (not shown). The driving mechanism drives the slider 24 by a fluid pressure from a pressure source such as an air compressor, for example, and opens and closes the pair of claw members 25 so as to advance and retreat in a posture substantially parallel to the X-axis direction. A groove 28a for supporting a support portion 35 (see fig. 7 described later) of the plant holder 3 is formed inside the claw portion 28 at the tip of the pair of claw members 25. The groove 28a has a shape (isosceles trapezoid in this example) corresponding to the shape of the support portion 35 when viewed from the Y-axis direction. Further, a pair of stopper pins 28b are provided inside the respective groove portions 28a at positions spaced apart from the distal ends of the claw members 25 by a predetermined distance, and the stopper pins 28b are opposed to each other and project in the approaching direction. In the illustrated example, each stopper pin 28b is formed in a cylindrical shape, but may be formed in a polygonal prism shape (not illustrated).

For example, when the plant holder 3 located at the end of the rail 4 is pulled out, the hand 21 closes the pair of claw members 25 with respect to the plant holder 3 by the operation of the driving mechanism, and the plant holder 3 is gripped between the claw portions 28 at the distal ends of the claw members 25 from both sides and pulled out. For example, when inserting the plant holder 3 into the end of the rail 4, the hand 21 moves the held plant holder 3 toward the end of the other rail 4 by driving the actuator 30, and inserts the same into the rail 4. Then, the plant holder 3 is pressed by 1 pitch (the longitudinal length of the plant holder 3) in the Y-axis direction (the longitudinal direction) while being held. This allows the inserted plant holder 3 and the plurality of plant holders 3 supported by the rail 4 to slide by 1 pitch. At this time, the end surface of the plant holder 3 gripped by the claw portion 28 on the side opposite to the pushing direction (the back side of the groove portion 28a, the rear side in the Y direction in the drawing) abuts against each stopper pin 28b, whereby even when there is a variation in the dimensional tolerance of the plant holder 3, the relative position of the plant holder 3 with respect to the claw portion 28 can be positioned at a predetermined position. Thus, the transfer robot 6 can accurately position the plant holder 3 held at that time and the alignment of the plurality of plant holders 3 supported on the rail 4 at the insertion destination in the transfer direction, with the position of the stopper pin 28b as a reference. After the above insertion operation, the hand 21 opens the pair of claw members 25 to release the grip of the plant holding device 3.

<3 > plant holding tool

Next, an example of the structure of the plant holder 3 will be described with reference to fig. 7 and 8. In addition, fig. 8 (a) shows a right-left direction orthogonal cross section viewed in the direction of arrows VIIIa to VIIIa in fig. 7 (a), and fig. 8 (b) shows a front-rear direction orthogonal cross section viewed in the direction of arrows VIIIb to VIIIb in fig. 7 (a). The directions shown in fig. 7 and 8 indicate directions in which the plant holder 3 is actually supported by the rail 4 and used.

The plant holder 3 holds a plant 2 to be cultivated in the plant cultivating system 1 for each 1 plant. The term "1 strain" as used herein means a single plant grown from a single seed. For example, as shown in fig. 9, a plant in which a plurality of (or one) leaves 2b are supported by 1 stem 2a and an individual plant is 1 plant is shown. In addition, for example, when a plurality of stems are present due to branching or the like, 1 plant is a plant whose roots 2c are linked to become one individual.

As shown in fig. 7 and 8, the plant holder 3 has a symmetrical shape in each of the left-right direction and the front-back direction. Therefore, the plant holder 3 is configured to have a directional compatibility in which it can be used in both the front and back directions (i.e., the transport direction), which is the longitudinal direction thereof. The plant holder 3 is integrally molded from a material having high sliding properties (for example, resin, metal, or the like), and is configured to be slidable with respect to the rail 4 supporting the plant holder 3. The plant holder 3 mainly includes a main body portion 31, a retainer tube portion 32, a guide tapered portion 33, and a guide plate portion 34, as a whole or a part thereof.

The main body 31 is a flat plate-shaped portion having a substantially rectangular shape with the longitudinal direction being the front-rear direction when viewed from above, and chamfered corners 31a having a gentle inclination (a small angle with respect to a horizontal plane) are formed on the four sides of each of the upper surface and the lower surface. In particular, the left and right side edges of the main body 31 function as support portions 35 supported by the claw members 25 when gripped by the hand 21 (see fig. 6) of the transfer robot 6. The support portion 35 in this example is formed into an isosceles trapezoid as viewed from the front-rear direction by the chamfer 31a, but may be formed into another shape such as a triangle or a circle. In this example, for example, 2 left and right support portions 35 are disposed at intervals in the front-rear direction, but may be connected to each other and 3 or more.

The retainer tube portion 32 is a cylindrical portion that penetrates in the vertical direction (vertical direction) at the center position in the front-rear direction and the left-right direction of the body portion 31, and has an upper end opening portion formed in a coplanar state (flat state without a step) without protruding from the upper surface of the body portion 31 and a lower end opening portion formed in a predetermined size protruding downward from the lower surface of the body portion 31. In this example, the retainer tube portion 32 has, for example, a cylindrical shape having a circular inner diameter, but may have a polygonal tube shape having another polygonal shape such as a square or the like in cross section perpendicular to the axis of the inner diameter. The detailed structure of the inner diameter portion of the retainer tube portion 32 will be described later (see fig. 10 described later).

The guide tapered portion 33 is a tapered portion formed to protrude downward from the lower surface of the body portion 31, and the dimension in the left-right direction (width direction dimension) is enlarged from both end portions in the front-rear direction (conveying direction) toward the central portion. The maximum width dimension of the guide tapered portion 33 on the center side of the body portion 31 is a dimension that can be fitted to a lower rail groove 43b (see fig. 9 described later) of the rail 4 described later with an appropriate fitting tolerance, and the maximum width direction dimension portion 36 is extended to the vicinity of the retainer tube portion 32.

The guide plate portions 34 are a pair of flat plate-shaped portions that protrude upward from the upper surface of the main body portion 31 and extend in the front-rear direction, and are provided in parallel at 2 locations in the left-right direction across the upper end opening of the retainer cylinder portion 32. The width dimension w1 and the left-right direction position of the pair of guide plate members 34 as a whole are substantially equal to the maximum width dimension 36 in contact with the guide taper 33.

As shown in the figures, the entire body portion 31 including the guide tapered portion 33 is formed of a hollow structure having a hollow bottom opening at the lower side, and therefore, the plant holder 3 as a whole is reduced in weight. As shown in the drawings, the body 31 and the guide tapers 33 are formed by flat surfaces 37 that are perpendicular to the front-rear direction (i.e., the conveying direction is the normal direction) and that are coplanar with each other at both ends in the front-rear direction.

The configuration of the plant holder 3 described above is an example, and a configuration other than the above may be adopted. For example, although the plant holder 3 is integrally molded in the above description, it may be configured by a plurality of members.

<4. track >

Next, an example of the structure of the track 4 will be described with reference to fig. 9. The direction shown in fig. 9 is a direction in which the rail 4 is provided on the cultivation shelf 5a, and is shown by an orthogonal cross section of the rail 4 in the front-rear direction.

As shown in fig. 9, the rail 4 has a rail portion 40 and a water groove portion 47, and is integrally molded from a material having high slidability (for example, resin, or metal). The rail portion 40 is provided with: a pair of left and right upper rail plates 41a extending in the front-rear direction and having a predetermined width in the left-right direction; and a pair of left and right lower rail plates 42a extending in the front-rear direction, each having a predetermined width in the left-right direction at a position below the upper rail plates 41 a. Upper rail protrusions 44 having the same size and protruding downward are formed on the opposite edges of the pair of upper rail plates 41 a. The vertical dimension of the upper rail protrusion 44 and the lower rail plate 42a is a dimension that can be fitted with an appropriate fitting tolerance with respect to the vertical thickness dimension of the main body 31 of the plant holding fixture 3, and the main body 31 of the plant holding fixture 3 is accommodated in the space that is separated. An upper rail groove 43a is formed between the pair of upper rail plates 41a (upper rail protrusion 44), and the upper rail groove 43a accommodates the pair of guide plate parts 34 of the plant holder 3. A lower rail groove 43b is formed between the pair of lower rail plates 42a, and the lower rail groove 43b is configured to receive the maximum widthwise dimension 36 of the guide tapered portion 33 of the plant holder 3.

The water tank 47 has: a pair of side wall portions 47a projecting downward from the pair of lower rail plates 42a and extending in the front-rear direction; and a bottom wall portion 47b extending in the front-rear direction across the lower ends of the pair of side wall portions 47a, the entire water tank portion 47 being a long water tank having a substantially U-shaped cross section and being open upward, and storing a culture solution 48 therein. The culture solution 48 is flowed in the front-rear direction by an appropriate flow means (not shown) such as a pump. The configuration of the front-rear direction end portion of the water tank portion 47 will be described in detail later (see fig. 12 and 13 described later).

The plant holding fixture 3 inserted into the rail 4 is accommodated in the space 46 of the rail portion 40. At this time, the lower surface of the main body 31 of the plant holding fixture 3 slidably contacts the upper surfaces of the left and right lower rail plates 42a, and the upper surface of the main body 31 abuts the left and right upper rail protrusions 44. In this way, the plant holding fixture 3 is sandwiched from above and below by the upper rail protrusion 44 and the lower rail 42a, and thus, the plant holding fixture 3 can be prevented from tilting or falling. At this time, the lower surface (surface in contact with the lower rail plate 42 a) of the main body 31 of the plant holder 3 functions as a holder support surface 38 that supports the entire plant holder 3 including the cylindrical holder portion 32. In this example, since the lower surface of the body portion 31 is open as described above, the contact area (contact resistance) between the holder support surface 38 and the rail support surface 45, which is the upper surface of the lower rail plate 42a, is reduced, and the slidability with the rail 4 can be improved.

Further, the plant holder 3 is housed in the following manner: the pair of guide plate portions 34 above the body portion 31 and the maximum width-direction dimension portion 36 of the guide tapered portion 33 below the body portion 31 are fitted between the upper and

lower rail grooves

43a, 43b, respectively, with appropriate fitting tolerances. Therefore, the plant holding fixture 3 can be moved along the longitudinal direction of the rail 4 while suppressing positional deviation in the left-right direction and fluctuation in the orientation in the horizontal direction.

Further, as shown in the drawing, when the plant holder 3 is used, the inner diameter portion of the holding cylinder portion 32 is filled with the culture medium 50, and the holding cylinder portion 32 holds the stem 2a of the plant 2 growing from the seed sown in the culture medium 50. Plant 2 can grow in the following way: the root 2c penetrates downward through the lower end opening of the cylindrical holder portion 32 and is immersed in the culture solution 48 in the water tank portion 47, and the leaf 2b bulges upward of the rail 4 through the upper end opening of the cylindrical holder portion 32. The culture medium 50 filled in the cylindrical holder 32 may be a gel-like culture medium such as agar, or a solid culture medium such as sponge, polyurethane, or asbestos.

In the plant cultivation system 1, spacers (not shown) are used, which are inserted between the plurality of plant holders 3 to define the intervals in the front-rear direction of the plant holders 3. The spacer is formed of a member common to the plant holder 3. That is, as the spacer, the plant holder 3 in an empty state in which the inner diameter portion of the holding cylinder 32 is not filled with the culture medium 50 is used. Therefore, in the rail 4, the plurality of spacers are also arranged in the front-rear direction together with the plurality of plant holders 3, and the entire spacers are supported so as to be movable. Further, each time the spacer is fed from one side in the front-rear direction of the rail 4, the whole of the plant holding fixture 3 and the spacer that have been supported moves toward the other side.

< 5: characteristic of the present embodiment

The plant cultivation system 1 having the above-described configuration can collectively cultivate a large number of plants 2 such as leaf vegetables by the steps of sowing, seedling raising, and field planting. In this cultivation step, the plant 2 to be cultivated is held by the plant holding jig 3 for each 1 plant, and the plant holding jig 3 is moved along the rail portion 40, thereby being transferred to the environment corresponding to each step, and the plant 2 is grown. In the plant cultivation system 1, for example, a hole (a retainer tube portion 32 in this example) that penetrates in the vertical direction is formed in the main body portion 31 of the plant holder 3, and growth starts from a state in which seeds of the plant 2 are sown in the culture medium 50 filled in the inside of the hole. The seed germinates, and the radicle 2e is rooted in the culture medium 50 and penetrates downward through the hole, and the sprout 2f grows upward, whereby finally, the hole of the plant holder 3 holds the stem 2a of the plant 2 so as to surround the outer periphery. As described above, the water tank 47 for storing the culture solution 48 is provided below the rail 40 for supporting the plant holder 3, and the plant 2 is immersed in the culture solution 48 and absorbed, thereby promoting the growth.

However, as described above, in the culture medium 50 filled in the hole portion of the plant holder 3 and seeded with the seed of the plant 2, there are many materials (agar, sponge, etc.) which are easily dried, and in order to continuously supply sufficient water to the seed before germination or the radicle 2e after germination, the culture medium 50 needs to be brought into contact with and absorbed by the culture solution 48 during the sowing period and the seedling growing period. On the other hand, in order to support the plant holder 3 on the rail portion 40 and to enable smooth sliding movement, the state in which the culture solution 48 is immersed in the contact portion between the main body portion 31 of the plant holder 3 and the rail portion 40 should be avoided.

In contrast, in the present embodiment, the plant holder 3 includes the holder cylindrical portion 32 that holds the plant 2 with the inner diameter portion whose axial direction is the vertical direction, and the body portion 31 that supports the holder cylindrical portion 32, and the lower end opening portion of the holder cylindrical portion 32 protrudes below the holder support surface 38 that supports the body portion 31.

That is, the plant holder 3 of the present embodiment has the hole for holding the plant 2 as the cylindrical holding cylinder 32, and the inner diameter portion thereof is filled with the culture medium 50 at the time of sowing. Further, the lower end opening of the retainer tube portion 32 protrudes downward from the retainer support surface 38 on the body portion 31 side, and the retainer support surface 38 contacts the rail support surface 45 on the rail portion 40 side to support the entire plant retainer 3. Thus, the lower end opening of the cylindrical holder portion 32 is positioned downward, the holder support surface 38 is positioned upward, and a level difference is provided therebetween, and the water level of the culture solution 48 in the water tank portion 47 on the lower side of the rail portion 40 is maintained between the level differences, whereby the culture solution 48 does not enter the contact portion between the rail portion 40 and the main body portion 31, and the culture solution 48 can be absorbed by the culture solution 50 inside through the lower end opening of the cylindrical holder portion 32. This structure will be described in detail in turn.

< 6: detailed structure and function of retainer tube section >

Fig. 10 is an enlarged view of the portion a in fig. 8 (a). In fig. 10, as described above, the retainer tube portion 32 is a tubular portion having the inner diameter portion 39 whose axial direction is the vertical direction and vertically penetrating the body portion 31. The upper end opening of the retainer tube portion 32 is formed in a flush state without protruding from the upper surface of the body portion 31, and the lower end opening is formed to protrude downward from the lower surface of the body portion 31 by a predetermined protruding dimension t 1.

In the example of the present embodiment, the inner diameter portion 39 of the retainer cylindrical portion 32 formed as a circular hole has a plurality of kinds of inner diameters depending on the axial position thereof, and the entire retainer cylindrical portion 32 can be divided into 4 parts, i.e., an upper end opening portion 39a, a straight cylindrical portion 39b, a small diameter portion 39c, and a lower end opening portion 39d, in this order from above to below in the axial position, depending on the difference in the structure based on the inner diameters.

A tapered chamfered portion 39e is formed over the entire axial range of the upper end opening portion 39a, and the inner diameter of the chamfered portion 39e continuously increases from the central portion toward the upper end portion.

The straight tube portion 39b is formed of a cylindrical portion having the same inner diameter dimension in the axial direction as the minimum inner diameter dimension of the center side of the upper end opening portion 39 a.

The small diameter portion 39c is opened with a smaller inner diameter than the straight tube portion 39 b. That is, the small diameter portion 39c is formed as a small opening portion having an axial orthogonal cross-sectional area smaller than the upper end opening portion 39a at an inner diameter dimension smaller than the maximum inner diameter dimension of the upper end opening portion 39a, in other words, at an axially intermediate position (position other than the upper end and the lower end) of the inner diameter portion 39.

The lower end opening 39d is formed such that the inner diameter thereof gradually increases from the central portion toward the lower end portion over the entire axial range thereof. That is, the lower end opening 39d is opened with a larger inner diameter than the small diameter portion 39c, in other words, the axial orthogonal cross-sectional area is larger than the small diameter portion 39 c.

The 4 positions of the upper end opening 39a, the straight tube portion 39b, the small diameter portion 39c, and the lower end opening 39d are formed by coaxial arrangement with their respective axial centers aligned.

Next, the functions of the above-described portions of the inner diameter portion 39 will be described with reference to fig. 11 (a) to 11 (d). In each of the drawings, in order to avoid complication of illustration, the retainer tube portion 32 is shown only in an axial side cross section corresponding to fig. 10, and illustration of other components is omitted.

Fig. 11 (a) shows a state of the inner diameter portion 39 of the retainer tube portion 32 at the time of sowing. In the example shown in the figure, in a state before sowing, the culture medium 50 is filled in the entire space from the upper end opening 39a to the lower end opening 39d in the inner diameter portion 39 of the holding cylinder portion 32, and sowing is performed such that the seeds 2d of the plant 2 are placed on the upper surface of the culture medium 50 at the upper end opening 39 a. In the illustrated example, the seeds 2d of the plant 2 are coated with a predetermined coating agent and are formed into a spherical shape as a whole, but seeds exposed without any coating (not shown) may be used. In this state, the period until the seed 2d absorbs the moisture in the medium 50 and germinates is the sowing period. As described above, the carrying-in conveyor 7 of this example carries in and supplies the plant holder 3 to the layer a of the stacked cultivation shelf 5 in a state where the seeds 2d germinate, but the plant holder 3 may be carried in and supplied to the stacked cultivation shelf 5 in a state during sowing before germination.

Here, even if the culture medium 50 filled in the inner diameter portion 39 of the retainer cylinder portion 32 is made of a soft material having a high specific gravity, the small diameter portion 39c having a small inner diameter can lock the culture medium 50 at a position halfway in the axial direction, and thus the culture medium 50 can be prevented from dropping downward due to its own weight.

Next, when the seed 2d germinates, as shown in fig. 11 (b), a radicle 2e (in the illustrated example, a shoot 2f) emerges from the seed 2 d. However, at the beginning of the germination, the radicle 2e may not necessarily extend directly downward to the culture medium 50, but may extend slightly upward temporarily as in the illustrated example. On the other hand, as described above, the retainer cylinder portion 32 of the plant holder 3 of the present embodiment has the tapered chamfered portion 39e that is opened to a larger extent than the straight cylinder portion 39b at the upper end opening portion 39a, and thus, as shown in fig. 11 (c), when the young roots 2e extending upward thereafter descend downward, the young roots are easily guided to the culture medium 50 of the inner diameter portion 39. The inner diameter of the straight tube portion 39b and the small diameter portion 39c is set to be relatively small so that the outer circumference of the stem 2a of the plant 2 in the final growth stage can be appropriately held, but the opening area of the upper end opening portion 39a is formed to be wider than the straight tube portion 39b, and thereby the contactable area of the radicle 2e with respect to the culture medium 50 is set to be wide.

Then, as shown in fig. 11 (d), the radicle 2e of the plant 2 having absorbed the nutrient of the culture medium 50 extends downward to penetrate the inner diameter portion 39, and thereafter, comes into contact with the culture solution 48 of the water tank portion 47 disposed on the lower side, and can absorb the nutrient therefrom (see fig. 9 described above). At this time, the root 2c of the plant 2 bulges so as to extend downward through the lower end opening 39d and expand in the horizontal direction, but since the axially orthogonal cross-sectional area of the lower end opening 39d is formed larger than the small diameter portion 39c, it is possible to assist the growth without hindering the free growth of the root 2c of the plant 2. The above period from the time of germination in fig. 11 (b) to the time of growth in fig. 11 (d) is a seedling growing period.

< 7: dimensional arrangement relationship between plant holding implement and track >

Next, a detailed configuration of the end portion of the rail 4 as viewed from the viewpoint of the dimensional arrangement relationship with the plant holder 3 will be described with reference to fig. 12 and 13. Fig. 12 is a diagram showing a cross section orthogonal to the left-right direction at the end of the rail 4, that is, a vertical cross section along the conveying direction of the plant holder 3. As the rail 4, for example, a rail 4 which is provided on the a-layer of the stacked cultivation shelves 5 and supports the plant holding fixture 3 in a seedling growing period (or a sowing period), and particularly, a conveying direction end portion (see the B portion in fig. 4) on the side from which the plant holding fixture 3 is taken out is assumed. Fig. 13 (a) shows a front-rear direction orthogonal cross section viewed from arrows XIIIa to XIIIa in fig. 12, and fig. 13 (b) shows a front-rear direction orthogonal cross section viewed from arrows XIIIb to XIIIb in fig. 12. In order to avoid complication of the drawing, the plant 2 is not shown.

In fig. 12 and 13, a water tank wall 47c and a drain 51 are provided at an end of the rail 4. The water tank wall 47c is a wall surface portion that engages with only the water tank portion 47 located on the lower side thereof at the end of the rail 4, is lower in height than the left and right side wall portions 47a, and functions as a bank portion that blocks the free outflow of the culture solution 48. The drain portion 51 is a hollow structure that surrounds the entire end of the water tank portion 47 including the water tank wall portion 47c and communicates the internal space thereof with the drain pipe 52.

In this configuration, the culture liquid 48 supplied into the water tank 47 from a flow means such as a pump not shown in the drawings overflows so that a part of the water surface thereof goes over the upper edge 47d of the water tank wall 47c, and is then discharged to the outside via the drain part 51 and the drain pipe 52. Thus, the culture liquid 48 flows in the water tank portion 47 in a direction from a water supply position (not shown) where water is supplied from the flow means toward the water tank wall portion 47c at the end of the rail 4, and the water level thereof depends on the height position of the upper edge portion 47d of the water tank wall portion 47c and the water supply rate (the amount of water supplied per unit time) of water supplied from the flow means.

Here, as described above, in the culture medium 50 filled in the inner diameter portion 39 of the plant holder 3 and seeded with the seeds 2d of the plant 2, there are many materials (agar, sponge, etc.) which are easily dried, and in order to continuously supply sufficient water to the pre-germination seeds 2d or the post-germination radicles 2e, the culture medium 50 needs to be brought into contact with and absorbed by the culture solution 48 during the sowing period and the seedling raising period. On the other hand, in order to allow the plant holder 3 to smoothly slide while being supported by the rail portion 40, the state in which the culture solution 48 is immersed in the contact portion between the main body portion 31 of the plant holder 3 and the rail portion 40 should be avoided. Furthermore, the height position of the upper edge portion 47d of the water tank wall portion 47c must be regulated so that the lower end opening 39d of the retaining cylinder portion 32 can pass above the upper edge portion 47d of the water tank wall portion 47c when the plant-holding fixture 3 is removed from the end of the rail portion 40 by the transfer robot 6 in the horizontal transfer direction. In order to satisfy the above conditions at the same time, in the plant cultivation system 1 of the example of the present embodiment, the plant holder 3 and the rail 4 are configured in the following dimensional arrangement relationship.

That is, as shown in fig. 10 and 13 (b), the retainer tube portion 32 of the plant retainer 3 is formed such that the lower end opening 39d thereof protrudes downward by a projection dimension t1 from the retainer support surface 38 of the body portion 31 (the surface on the plant retainer 3 side that contacts the rail support surface 45 of the lower rail plate 42 a). That is, in the plant holder 3 in the posture in use, the lower end of the holder cylindrical portion 32 is relatively located lower than the holder support surface 38, and a step of a projection dimension t1 is provided therebetween. Further, by maintaining the water level of the culture solution 48 in the water tank 47 on the lower side of the rail portion 40 at the height difference t1, the culture solution 48 does not enter the contact portion between the rail portion 40 and the main body portion 31, and the culture solution 48 can be absorbed by the culture solution 50 inside through the lower end opening 39d of the cylindrical holder portion 32.

Here, as shown in fig. 13, with reference to the height position of the rail support surface 45 on the rail 4 side which is in contact with the holding fixture support surface 38 of the plant holding fixture 3, the height difference from the upper edge portion 47d of the water tank wall portion 47c located below is set to t 2. Further, the water level rise dimension Δ t is set to an amount that the water level can be raised in the culture solution 48 by its own surface tension.

In this case, the water level of the culture liquid 48 can be maintained at a high level or more separated downward by at least t2- Δ t relative to the height of the rail support surface 45. This is because, regardless of the water supply speed, the culture solution 48 in the water tank 47 can be brought into a water level state higher than at least the upper edge 47d of the water tank wall 47c by a predetermined water level rise Δ t by its own surface tension as long as the water supply is continued. Therefore, in order to always bring the lower end opening 39d into contact with the water surface of the culture solution 48, the water level of the culture solution 48 needs to be relatively higher than the lower end position of the lower end opening 39d, and therefore, the relative height position (the downward distance from the rail support surface 45) of the upper edge portion 47d may be set as follows,

t2-Δt≤t1

→ t2 ≦ t1+ Δ t … (equation 1).

Thus, by setting the design dimensions of the rail 4 including the water tank wall 47c, the contact state between the water surface of the culture solution 48 and the lower end opening 39d can be always ensured. Further, the water supply speed may be adjusted so that the water level of the culture solution 48 is not higher than the rail support surface 45.

On the other hand, the end of the rail portion 40 and the water tank wall portion 47c are disposed close to each other in the front-rear direction so that the length of the entire rail 4 can be shortened. Therefore, as described above, it is necessary to dispose the upper edge portion 47d relatively lower than the lower end position of the lower end opening portion 39d so that the lower end opening portion 39d of the holding cylinder portion 32 passes through without interfering with the upper edge portion 47d of the water tank wall portion 47c when the transfer robot 6 removes the plant holding fixture 3 from the end portion of the rail portion 40 in the horizontal transfer direction. In contrast, the relative height position (the distance of separation downward from the rail support surface 45) of the upper edge portion 47d may be set such that,

t 1. ltoreq.t 2 … (formula 2).

According to the above (formula 1) and (formula 2), the upper edge portion 47d of the water tank wall portion 47c in the present embodiment is disposed so that the height difference t2(t1 ≦ t2 ≦ t1+ Δ t: design value) between the protrusion dimension t1 (design value) of the lower end opening 39d and the water level rise dimension Δ t (physical constant of the culture solution 48) of the culture solution 48, which is an amount capable of raising the water level by its own surface tension, is not more than the total dimension (t1+ Δ t) and not more than the protrusion dimension t1 is positioned below the rail support surface 45.

The configuration of the dimensional arrangement relationship of fig. 12 and 13 described above is not limited to the end of the rail 4 on the side from which the plant holder 3 is removed, and can be applied to the end of the rail 4 on the side opposite to the side from which the plant holder 3 is inserted.

<8 > effects of the embodiment

As described above, in the plant cultivation system 1 of the present embodiment, the plant holder 3 includes: a holding cylinder portion 32 for holding the plant 2 by an inner diameter portion 39 having a vertical direction as an axial direction; and a body portion 31 for supporting the retainer tube portion 32, wherein the lower end opening portion 39d of the retainer tube portion 32 protrudes downward from the retainer support surface 38 for supporting the body portion 31.

Thus, the lower end opening 39d of the cylindrical holder portion 32 is positioned downward, the holder support surface 38 is positioned upward, and a level difference is provided therebetween, and by maintaining the water level of the culture solution 48 in the water tank portion 47 on the lower side of the rail portion 40 at the level difference, the culture solution 48 does not enter the contact portion between the rail portion 40 and the main body portion 31, and the culture solution 50 inside can be absorbed by the culture solution 48 through the lower end opening 39d of the cylindrical holder portion 32. As a result, the movement performance of the plant holder 3 can be ensured, and the growth function of the plant 2 can be improved.

In the present embodiment, in particular, the water tank 47 is disposed so that the upper edge 47d of the water tank wall 47c located at the end in the conveying direction is located below the rail support surface 45 by a height difference (t2 ≦ t1+ Δ t1) equal to or smaller than the total size (t1+ Δ t) of the protrusion size t1 of the plant holding instrument 3 from the holding instrument support surface 38 toward the lower end opening 39d and the water level rise size Δ t of the culture solution 48 by which the water level rises due to surface tension.

Thus, the water level of the culture solution 48 in the water tank 47 can be higher than at least the upper edge 47d of the water tank wall 47c by the water level rise Δ t due to the surface tension. Therefore, in the structure in which the upper edge portion 47d is arranged in accordance with the above-described dimensional relationship (t 2. ltoreq. t1+ Δ t1) so as to utilize the height difference, the lower end opening portion 39d of the retainer tube portion 32 can be maintained in a state of being constantly in contact at a position lower than the water level of the culture solution 48.

In the present embodiment, in particular, the water tank 47 is disposed such that the upper edge 47d of the water tank wall 47c located at the end in the conveying direction is located below the rail support surface 45 by a height difference (t2 ≧ t1) equal to or greater than the projection dimension t1 of the plant holding fixture 3 from the fixture support surface 38 toward the lower end opening 39 d. Thus, even when the plant holder 3 is removed from the end of the rail portion 40 in the horizontal conveying direction, the lower end opening 39d of the holding cylinder portion 32 can pass over the upper edge portion 47d of the water tank wall portion 47c positioned at the end of the water tank portion 47 in the conveying direction without interfering therewith.

In the present embodiment, in particular, the retainer tube portion 32 of the plant holder 3 has a small diameter portion 39c at a position halfway in the axial direction of the inner diameter portion 39, and the axial orthogonal cross-sectional area of the small diameter portion 39c is smaller than that of the upper end opening portion 39 a. Thus, even if the culture medium 50 filled in the inner diameter portion 39 of the retainer cylinder portion 32 is made of a soft material having a high specific gravity, the small diameter portion 39c can lock the culture medium 50 at a position halfway in the axial direction, and therefore, the culture medium 50 can be prevented from dropping downward due to its own weight.

In the present embodiment, in particular, the cylindrical holding portion 32 of the plant holder 3 has a tapered chamfered portion 39e formed at the upper end opening portion 39 a. Accordingly, there is no substantially right-angled corner in the upper end opening 39a of the holding tube 32, so that damage to the stem 2a of the plant 2 to be held can be prevented, and when the radicle 2e extends upward during germination of the seed 2d, the opening area is thereafter large, so that the root can be easily guided to the inner diameter portion 39 (culture medium 50).

In the present embodiment, in particular, the cylindrical retainer portion 32 of the plant holder 3 is formed such that the axial orthogonal cross-sectional area of the lower end opening 39d is larger than the small diameter portion 39 c. Thus, the stem 2a of the plant 2 is reliably held by the engagement of the small diameter portion 39c in the inner diameter portion 39 of the holding cylinder portion 32, and the root 2c of the plant 2 can be easily expanded in the horizontal direction when extending downward through the lower end opening portion 39 d. Further, when only the root 2c is removed from the plant holding tool 3 after the plant 2 has grown sufficiently and the leaf 2b has been cut from the stem 2a, the removal operation can be easily performed because the cross-sectional area orthogonal to the axis of the lower end opening 39d is made wide.

In the present embodiment, in particular, the main body 31 of the plant holder 3 has the guide taper portion 33, and the guide taper portion 33 protrudes downward from the holder support surface 38, and the width direction dimension (the left-right direction orthogonal to the conveying direction) is enlarged from the end portion toward the center portion in the conveying direction. Thus, when the plant holder 3 is inserted into the lower rail groove 43b between the 2 lower rail plates 42a arranged on the left and right, the distal end of the guide tapered portion 33 located at the end portion of the main body portion 31 is far smaller than the width dimension of the lower rail groove 43b, and thus the insertion operation is facilitated. Therefore, the insertion function of the plant holder 3 can be improved even when the position of the lower rail groove 43b is changed due to thermal expansion of the rail portion 40 itself or when the operation accuracy of the transfer robot 6 is low.

In the present embodiment, in particular, the main body 31 of the plant holder 3 including the guide tapered portion 33 is formed of a hollow structure having a lower opening. This reduces the weight of the entire plant holder 3, and reduces the contact resistance with the rail support surface 45 by reducing the area of the holder support surface 38 of the main body 31, thereby improving the movement performance of the plant holder 3 on the rail 40.

In the present embodiment, in particular, both ends of the main body 31 of the plant holder 3 in the conveying direction are formed by flat surfaces 37 that are orthogonal to the conveying direction (normal direction to the conveying direction). Accordingly, even when the plurality of plant holders 3 are conveyed in a state of being closely attached to each other and aligned in a row on the rail portion 40 so as to be pushed integrally from one end portion, it is possible to suppress the riding or the positional deviation between the adjacent plant holders 3 and to reliably transmit the pushing thrust while maintaining the aligned state in a straight line. Further, since the adhesion between the plant holders 3 in such an arranged state is improved, the light shielding property from the light source 15 located above toward the inside of the water tank 47 located below is also improved, and therefore, the generation of zinc powder or the like in the culture solution 48 in the water tank 17 can be suppressed.

The respective end portions of the body 31 in the conveying direction are not limited to the flat surfaces 37, and as shown in fig. 14, a convex portion and a concave portion may be formed in combination at the respective end portions so as to be engaged with each other. For example, as shown in fig. 14 (a), in one plant holder 3, a rectangular convex portion 37a may be formed at the front end in the conveying direction, and a rectangular concave portion 37b may be formed at the rear end. Thus, when a new plant holder 3 is pushed into the row of already arranged plant holders 3 and arranged, the convex portion 37a on the pushing side and the concave portion 37b on the pushed side are engaged with each other, and the plant holders 3 can be coupled to each other more reliably. Further, for example, as shown in fig. 14 (b), the plant holder 3 may be formed by a combination of a mountain-shaped convex portion 37c and a mountain-shaped concave portion 37d, and in this case, the connection between the plant holders is also secured. The positions of the convex portion and the concave portion may be opposite to each other with respect to the conveying direction, and the convex portion and the concave portion may be matched with each other, or may be formed in a shape other than the above-described rectangular shape or the mountain shape.

In the above description, when there are descriptions such as "perpendicular", "parallel", "planar", etc., the description is not intended to be strict. That is, these "perpendicular", "parallel" and "planar" are intended to mean "substantially perpendicular", "substantially parallel" and "substantially planar", which allow design and manufacturing tolerances and errors.

In the above description, when there are descriptions such as "same", "equal", and "different" in terms of apparent size or dimension, the descriptions are not intended to be strict. That is, these terms "the same", "the same" and "different" are intended to mean "substantially the same", "substantially the same" and "substantially different", which allow design and manufacturing tolerances and errors.

In addition to the above, the methods of the above embodiments and the modifications may be used in combination as appropriate.

In addition, although not illustrated, the above embodiment and each modification can be implemented by applying various modifications without departing from the scope of the invention.

Claims

1. A plant cultivation system, characterized in that the plant cultivation system has:

a plant holding tool for holding a plant to be cultivated;

a rail portion configured to support the plurality of plant holders by a rail support surface so as to be movable in a conveying direction; and

a water tank part which is arranged below the rail part, has an open upper part and stores a culture solution therein,

the plant holding device comprises:

a holding cylinder portion that holds the plant by an inner diameter portion having a vertical direction as an axial direction; and

a main body portion that supports the retainer cylinder portion,

the lower end opening of the retainer tube portion protrudes downward beyond a retainer support surface that supports the main body portion.

2. The plant cultivation system as claimed in claim 1,

the water tank portion is disposed such that an upper edge portion of the water tank wall portion located at an end in the transport direction is located below the rail support surface with a height difference equal to or smaller than a total of a protruding dimension of the lower end opening of the plant holding fixture from the fixture support surface toward a lower side and a water level rising dimension of a water level rising amount due to surface tension in the culture solution.

3. The plant cultivation system as claimed in claim 1 or 2,

the water tank portion is disposed so that an upper edge portion of the water tank wall portion located at an end in the conveying direction is located below the rail support surface by a height difference equal to or greater than a projecting dimension of the lower end opening of the plant holding fixture from the fixture support surface toward a lower side.

4. A plant holding appliance, comprising:

a holding cylinder portion that holds a plant by an inner diameter portion having a vertical direction as an axial direction; and

a main body portion that supports the retainer cylinder portion,

the plant-holding appliance is characterized in that,

5. The plant holding appliance of claim 4,

the retainer cylinder portion has a small opening portion at an axial intermediate position of the inner diameter portion, and an axially orthogonal cross-sectional area of the small opening portion is smaller than that of the upper end opening portion.

6. The plant holding appliance of claim 5,

the retainer cylinder portion has a tapered chamfered portion formed at an upper end opening portion.

7. The plant holding appliance according to claim 5 or 6,

the cross-sectional area of the retainer cylinder portion perpendicular to the axis of the lower end opening is larger than the small opening.

8. The plant holding appliance according to any one of claims 4 to 6,

the main body portion has a guide tapered portion that protrudes downward from the holding fixture support surface, and the width-directional dimension of the guide tapered portion increases from the end portion in the conveying direction toward the central portion.

9. The plant holding appliance according to any one of claims 4 to 6,

the main body portion is formed of a hollow structure having an opening at a lower side.

10. The plant holding appliance according to any one of claims 4 to 6,

both ends of the main body in the conveying direction are formed by flat surfaces orthogonal to the conveying direction.