Transplanter

Abstract

To provide a transplanter capable of accurately detecting the height of the surface of soil even when the height of the surface of soil changes, and thereby capable of planting seedlings in the soil with a predetermined planting depth.SOLUTION: A transplanter includes a travelling machine body, a planting part having a seedling planting mechanism for plating seedlings in soil, which is liftably connected to the rear part of the travelling machine body, and a mulch sheet releasing and laying mechanism for releasing and laying a mulch sheet on the surface of soil before planting seedlings. The transplanter further includes a height detection mechanism for detecting the height of the surface of soil that serves as a reference for setting a seedling planting depth before the mulch sheet is laid on the surface of soil.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a transplanter.

Background Art

[0002] For example, Patent Document 1 discloses a multi-transplanter. The multi-transplanter is configured such that a transplanting work implement is vertically movably connected to a traveling machine body, a sheet (also referred to as a "multi-sheet") is unwound so as to cover a field surface, and a plurality of rows of planting work is performed from above the sheet on the field surface covered with the sheet. The multi-transplanter includes a sensor roller for setting a planting depth during the planting work. The sensor roller is located above the sheet covering the field surface and senses the height of the field surface from above the sheet.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the field is a paddy field, the field surface (paddy field surface) after puddling is flat. On the other hand, when the field is a dry field, there are variations in tillage or ridging in the dry field. For this reason, the height of the soil surface, that is, the height of the ridges, is often not constant. Therefore, in a configuration that senses the height of the field surface (ridge height) from above the sheet as in Patent Document 1, when the ridge height changes, it may not be possible to accurately detect the ridge height due to the presence of the sheet. For example, when there are irregularities in the ridges in the traveling direction of the traveling machine body and the sheet laid on the ridges is stretched horizontally between the convex portions of the ridges, it becomes impossible to accurately detect the height of the surface of the concave portion located between the convex portions of the ridges. For this reason, it has been difficult to apply the multi-transplanter of Patent Document 1 to dry field cultivation.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide a transplanter having a multi-sheet feeding and laying mechanism, which can accurately detect the height of the soil surface (ridge height) even when the height of the soil surface changes, and thereby can plant seedlings in the soil at a predetermined planting depth.

Means for Solving the Problems

[0006] A transplanter according to one aspect of the present invention includes a traveling machine body, a seedling planting mechanism for planting seedlings in the soil, a planting part that is connected to the rear of the traveling machine body so as to be vertically movable, and a multi-sheet feeding and laying mechanism for feeding and laying a multi-sheet on the surface of the soil before planting the seedlings. The transplanter is provided with a height detection mechanism for detecting the height of the soil surface, which serves as a reference for setting the planting depth of the seedlings, before the multi-sheet is laid on the surface of the soil.

Effects of the Invention

[0007] According to the above configuration, even when the height of the soil surface changes, the height of the soil surface can be accurately detected, and thereby seedlings can be planted in the soil at a predetermined planting depth.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17A

Figure 17B

Figure 18A

Figure 18B

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

Mode for Carrying Out the Invention

[0009] Embodiments of the present invention will be described with reference to the drawings. For convenience of explanation below, the directions are defined as follows. First, the traveling direction of the traveling machine body 2 (the left direction in FIG. 1) is defined as the front (forward), and the opposite direction is defined as the rear (backward). Also, the left side toward the traveling direction of the traveling machine body 2 is referred to as the left (leftward), and the right side toward the traveling direction is referred to as the right (rightward). Further, the gravitational direction is defined as the vertical direction, the upstream side is defined as the upper (upward), and the downstream side is defined as the lower (downward). In the drawings, if necessary, the front is indicated by the symbol "F", the rear is indicated by "B", the left is indicated by "L", the right is indicated by "R", the upper is indicated by "U", and the lower is indicated by "D".

[0010] <1. Outline of the Transplanter> FIG. 1 is a side view showing a schematic configuration of a transplanter 1 according to an embodiment of the present invention. FIG. 2 is a side view of a planting unit 3 of the transplanter 1 in FIG. 1. In FIG. 2, illustration of the left discharge plate 34L, the left skirt pressing roller 51L, and the left soil gathering disk 52L shown in FIG. 1 is omitted for convenience. The transplanter 1 in the present embodiment is a vegetable transplanter for transplanting (planting) seedlings of vegetables such as cabbages into soil. The transplanter 1 includes a traveling body 2 and a planting unit 3.

[0011] The traveling body 2 is supported by left and right front wheels 1a and left and right rear wheels 1b. An engine 1c as a drive source is mounted on the traveling body 2. The power output from the engine 1c is transmitted to a driven part via a transmission part 1d. The driven part includes the front wheels 1a and the rear wheels 1b, as well as the planting unit 3 described later. Therefore, the above-described transmission part 1d includes a PTO (Power Take Off) shaft 1d1 (see FIG. 2) for driving the planting unit 3.

[0012] The traveling body 2 includes a seat 2a for the operator to sit on, an operation part 2b operated by the operator, and a preliminary mounting part 2c for mounting a preliminary seedling mat. The operation part 2b includes a steering handle for operating the traveling direction, a shift lever for operating the traveling speed, and a work lever for operating the planting unit 3.

[0013] The planting unit 3 is connected to the rear of the traveling body 2 via a lifting mechanism 4 so as to be liftable. The lifting mechanism 4 includes a top link 41, a lower link 42, and a lifting cylinder 43. The top link 41 and the lower link 42 connect the traveling body 2 and the planting unit 3. The lifting cylinder 43 is connected to the lower link 42 via a connection part 44. For example, by operating the lifting cylinder 43 to expand and contract according to the operation of the operation part 2b (work lever), the lower link 42 is rotated via the connection part 44 and the top link 41 is rotated. Thereby, the planting unit 3 can be lifted with respect to the traveling body 2.

[0014] The planting unit 3 includes a seedling placing device 31 and a seedling planting mechanism 32 (see FIG. 2). The seedling planting mechanism 32 scrapes one seedling from the seedling mat MT (see FIG. 3) placed on the seedling placing device 31, and plants the scraped seedling into the soil (ridge) from above the multi-sheet S described later.

[0015] FIG. 3 is a rear view of the seedling placing device 31 seen from the rear. The seedling placing device 31 conveys the seedling mat MT placed on the seedling placing table 311 downward by driving the vertical feed belt 312 (see FIG. 2). The transplanter 1 of the present embodiment is configured by arranging six one-row seedling placing tables 311 capable of placing one row of the seedling mat MT side by side in the left-right direction, and can plant up to six rows of seedlings. Here, for the sake of simplicity, a configuration for planting one row of seedlings is shown as an example.

[0016] The vertical feed belt 312 is vertically fed and driven by a vertical feed mechanism 313 (see FIG. 2). The vertical feed mechanism 313 vertically feeds the vertical feed belt 312 by one seedling (one row) at the timing when the scraping of the seedlings for one row in the left-right direction from the seedling mat MT is completed. Thereby, the seedling planting mechanism 32 can scrape the seedlings in the next row from the seedling mat MT. Further, the seedling placing table 311 is horizontally fed and driven by a horizontal feed mechanism 314 (see FIG. 2). The horizontal feed mechanism 314 horizontally feeds the seedling placing table 311 in one of the left and right directions after the vertical feed belt 312 vertically feeds the seedling mat MT. In particular, the horizontal feed mechanism 314 reverses the horizontal feed direction of the seedling placing table 311 every time the vertical feed belt 312 vertically feeds the seedling mat MT (every time the scraping of the seedlings for one row from the seedling mat MT is completed). Thereby, the seedling planting mechanism 32 can continuously scrape the seedlings in the next row after the scraping of the seedlings for one row from the seedling mat MT is completed.

[0017] The horizontal feed mechanism 314 has a drive shaft (horizontal feed shaft) for horizontally feeding the seedling placing table 311. The horizontal feed shaft is driven by the power transmitted from the engine 1c via the PTO shaft 1d1. A drive cam 314a is attached to the horizontal feed shaft. The drive cam 314a rotates as the horizontal feed shaft rotates.

[0018] The vertical feeding mechanism 313 has a drive shaft (vertical feeding shaft) for driving the vertical feeding belt 312 and a rotating shaft for rotating the vertical feeding shaft. A driven cam 313a is attached to the rotating shaft. The driven cam 313a contacts the drive cam 314a of the lateral feeding mechanism 314 at a predetermined timing. Here, the above-mentioned predetermined timing is the timing when the scraping of the seedlings for one row from the seedling mat MT is completed.

[0019] When the drive cam 314a contacts the driven cam 313a at the above-mentioned predetermined timing due to the rotation of the lateral feeding shaft and rotates the rotating shaft by a predetermined angle together with the driven cam 313a, the power generated by the rotation of the rotating shaft is transmitted to the vertical feeding shaft via a power transmission mechanism (not shown). As a result, the vertical feeding belt 312 is vertically fed and driven at the above-mentioned predetermined timing. When the contact between the drive cam 314a and the driven cam 313a is released, the driven cam 313a rotates in the reverse direction by the biasing force of a biasing member (not shown) and returns to the initial position before rotation. Note that the above-mentioned power transmission mechanism is configured to include, for example, gears, belts, chains, etc., but may be provided as necessary. That is, it may be configured to directly transmit the power of the rotating shaft to which the driven cam 313a is attached to the vertical feeding shaft (without providing a power transmission mechanism).

[0020] FIG. 4 is a side view of the seedling planting mechanism 32. The seedling planting mechanism 32 has a rotary case 321 and a planting unit 322. The seedling planting mechanism 32 is driven by the power taken out from the PTO shaft 1d1.

[0021] The rotary case 321 is rotatably supported by the planting case 33a of the planting section 3. The planting case 33a is fixed to the planting frame 33 (particularly the rear surface of the post-planting frame 332 (see FIG. 7)). The rotating shaft 321a of the rotary case 321 extends in the left-right direction.

[0022] The planting unit 322 has planting claws 322a. The planting unit 322 is supported by the rotary case 321 at two positions. The two planting units 322 are pivotally supported by the rotary case 321 at positions that are point-symmetrical with respect to the rotation axis 321a of the rotary case 321 in a side view. When the rotary case 321 rotates, the planting claws 322a of each planting unit 322 sequentially scrape seedlings one by one from the seedling mat MT (see Fig. 3) and plant the scraped seedlings in the ridges in sequence. Note that the number of planting units 322 supported by the rotary case 321 may be one.

[0023] Fig. 5 is a perspective view showing an enlarged view of one planting unit 322. The planting unit 322 further has a pushing member 322b and a holding member 322c. The pushing member 322b is provided to push out the seedlings scraped from the seedling mat MT by the planting claws 322a. The pushing member 322b slides in the direction opposite to the pushing direction at a predetermined timing before scraping. Thereby, it becomes possible to scrape the seedlings from the seedling mat MT by the planting claws 322a. The scraped seedlings are held by the planting claws 322a and the holding member 322c. Then, the pushing member 322b slides in the pushing direction at a predetermined timing before planting. Thereby, the seedlings held by the planting claws 322a and the holding member 322c are pushed out and planted in the ridges.

[0024] The planting unit 322 further includes a cutter 322d. The cutter 322d is located on the downstream side in the rotational direction of the rotary case 321 with respect to the planting claws 322a. That is, the cutter 322d is in a positional relationship that precedes the planting claws 322a when the rotary case 321 rotates. The cutter 322d opens a rectangular hole in a plan view in the multi-sheet S (see FIGS. 1 and 2) fed out from the multi-sheet feeding and laying mechanism 36 described later immediately before the seedlings are planted by the planting claws 322a due to the rotation of the rotary case 321. Thereby, the seedlings held by the planting claws 322a and the holding member 322c can be planted in the ridge through the hole in the multi-sheet S. Note that the sheet piece that closed the hole in the multi-sheet S is not completely separated from the multi-sheet S, but is connected to the surrounding sheet through a part of the outer shape of the hole (one side of the rectangle).

[0025] The cutter 322d has a main body portion 322d1 formed by bending a flat plate and a protruding claw (key claw) 322d2. The protruding claws 322d2 are provided at the left and right corner portions on the tip side (the contact side with the multi-sheet S) of the main body portion 322d1 and protrude on the downstream side in the rotational direction of the rotary case 321 with respect to the main body portion 322d1. That is, the protruding claws 322d2 are in a positional relationship that precedes the main body portion 322d1 when the rotary case 321 rotates. In such a configuration of the cutter 322d, sharp claws such as the protruding claws 322d2 contact the multi-sheet S at an angle (from a direction close to perpendicular to the multi-sheet S). For this reason, the cutter 322d is less likely to slide on the multi-sheet S. That is, the protruding claws 322d2 surely catch on the multi-sheet S and pierce the multi-sheet S. Thereby, a hole can be surely opened in the multi-sheet S, and the hole can be opened in the multi-sheet S with an accurate size and position. Further, by cutting the multi-sheet S with the two protruding claws 322d2 on both the left and right sides, a hole with a minimum size through which the seedlings can pass can be opened in the multi-sheet S.

[0026] As shown in FIG. 2, an earth discharging plate 34 is supported by a planting frame 33 of the planting unit 3. The earth discharging plate 34 includes a right earth discharging plate 34R and a left earth discharging plate 34L (see FIG. 1). The right earth discharging plate 34R and the left earth discharging plate 34L form a ridge for planting seedlings by scraping the soil as the traveling body 2 travels. The mounting positions of the right earth discharging plate 34R and the left earth discharging plate 34L with respect to the planting frame 33 in the left-right direction and the up-down direction are adjustable according to the width and height of the ridge to be formed.

[0027] A planting depth adjusting mechanism 35, a multi-sheet feeding and laying mechanism 36, a pressing mechanism 37, and an under-sheet working body 38 are supported by the planting frame 33 of the planting unit 3. Further, a height detection mechanism 39 is supported by the planting depth adjusting mechanism 35. Details of the planting depth adjusting mechanism 35, the multi-sheet feeding and laying mechanism 36, the pressing mechanism 37, the under-sheet working body 38, and the height detection mechanism 39 will be described later.

[0028] A trailing edge pressing roller 51, a soil gathering disk 52, and a soil covering wheel 53 are supported by the planting frame 33 via an auxiliary frame (not shown). The trailing edge pressing roller 51 includes a right trailing edge pressing roller 51R and a left trailing edge pressing roller 51L (see FIG. 1). The right trailing edge pressing roller 51R and the left trailing edge pressing roller 51L press both ends (the portions protruding outside the ridge) of the multi-sheet S laid over the ridge and fed out from the multi-sheet feeding and laying mechanism 36.

[0029] The soil gathering disk 52 includes a right soil gathering disk 52R and a left soil gathering disk 52L (see FIG. 1). The right soil gathering disk 52R and the left soil gathering disk 52L cover both ends of the multi-sheet S pressed by the right trailing edge pressing roller 51R and the left trailing edge pressing roller 51L with soil so that the multi-sheet S does not fly off. The soil covering wheel 53 includes a right soil covering wheel (not shown) and a left soil covering wheel 53L. The right soil covering wheel and the left soil covering wheel 53L press the soil on the right and left sides of the seedlings planted in the ridge by the seedling planting mechanism 32 via the multi-sheet S. As a result, the periphery of the planted seedlings is solidified with soil, and thus seedling lodging is suppressed.

[0030] <2. Details of the multi-sheet feeding and laying mechanism> FIG. 6 is a side view showing a part of the planting unit 3. As shown in the figure, the multi-sheet feeding and laying mechanism 36 has a roll holding part 361 and a sheet feeding guide part 362. The roll holding part 361 holds a roll body S0 around which a multi-sheet S is wound in a roll shape, and feeds out the outermost multi-sheet S of the roll body S0. The multi-sheet S is composed of, for example, a vinyl sheet. The sheet feeding guide part 362 guides the multi-sheet S fed out from the roll holding part 361 toward the surface H of the soil (ridge) in front of the seedling planting position by the seedling planting mechanism 32, and lays it on the surface H of the soil. That is, the transplanter 1 of the present embodiment includes a multi-sheet feeding and laying mechanism 36 that feeds out and lays the multi-sheet S on the surface H of the soil before planting the seedlings. The roll holding part 361 and the sheet feeding guide part 362 of the multi-sheet feeding and laying mechanism 36 are supported by the planting frame 33. That is, the multi-sheet feeding and laying mechanism 36 is provided in the planting unit 3.

[0031] Here, the details of the planting frame 33 will be described first. FIG. 7 is a perspective view of the planting frame 33 when viewed obliquely from the rear. The planting frame 33 has a pre-planting frame 331, a post-planting frame 332, and side pipes 333. The pre-planting frame 331 extends in the left-right direction and is located on the front side of the planting frame 33. The post-planting frame 332 extends in the left-right direction and is located behind the pre-planting frame 331. The post-planting frame 332 is longer in the left-right direction than the pre-planting frame 331.

[0032] The side pipes 333 include a right pipe 333R and a left pipe 333L. The right pipe 333R extends in the front-rear direction and connects the right end of the pre-planting frame 331 and the post-planting frame 332. The left pipe 333L extends in the front-rear direction and connects the left end of the pre-planting frame 331 and the post-planting frame 332.

[0033] On the right end of the post-planting frame 332, a right side frame 334R is erected. On the left end of the post-planting frame 332, a left side frame 334L is erected. The right side frame 334R and the left side frame 334L extend upward from the connecting side with the post-planting frame 332 and have a shape that bends obliquely forward midway. The right side frame 334R and the left side frame 334L are connected by an upper frame 335 and a cross frame 336. The upper frame 335 extends in the left-right direction and connects the upper parts of the right side frame 334R and the left side frame 334L. The cross frame 336 is located behind the upper frame 335 and obliquely downward and extends in the left-right direction to connect the right side frame 334R and the left side frame 334L. The above-described seedling mounting device 31 (see FIG. 1 etc.) is driven to traverse horizontally while maintaining a forward-tilted posture along the upper frame 335 and the cross frame 336.

[0034] FIG. 8 is a perspective view of the above-described roll holding portion 361 as viewed from below. As shown in the figure, the roll holding portion 361 has a shaft holding frame 361a. The shaft holding frame 361a extends in the left-right direction and holds both axial ends of the roll body S0. The shaft holding frame 361a is attached to the pre-planting frame 331 via a frame support stay 361b. The frame support stay 361b is connected to approximately the center portion in the left-right direction on the rear surface of the pre-planting frame 331, for example, by bolt fastening.

[0035] FIG. 9 is a perspective view of the above-described sheet feeding guide portion 362 as viewed from the front. As shown in the figure, the sheet feeding guide portion 362 has a first guide roller 362a, a second guide roller 362b, and a roller holding frame 362c. The first guide roller 362a is located in front of the second guide roller 362b and guides the multi-sheet S fed out from the shaft holding frame 361a toward the second guide roller 362b. The second guide roller 362b presses the multi-sheet S guided by the first guide roller 362a downward and guides it so as to approach the surface H of the soil.

[0036] The roller holding frame 362c includes a right holding frame 362cR and a left holding frame 362cL. The right holding frame 362cR and the left holding frame 362cL extend from above downward and have a shape that bends obliquely backward in the middle.

[0037] The right holding frame 362cR is respectively arranged on the right sides of the first guide roller 362a and the second guide roller 362b, and rotatably supports the right ends of the rotation axes of the first guide roller 362a and the second guide roller 362b. The left holding frame 362cL is respectively arranged on the left sides of the first guide roller 362a and the second guide roller 362b, and rotatably supports the left ends of the rotation axes of the first guide roller 362a and the second guide roller 362b. The first guide roller 362a is rotatably supported near the bent portions of the right holding frame 362cR and the left holding frame 362cL. The second guide roller 362b is rotatably supported at the lower end portions (rear end portions) of the right holding frame 362cR and the left holding frame 362cL.

[0038] The right holding frame 362cR is attached to the post-planting frame 332 via a right support stay 363R at a position above the first guide roller 362a. The right support stay 363R is connected to the front surface of the post-planting frame 332, for example, by bolt fastening. Similarly, the left holding frame 362cL is attached to the post-planting frame 332 via a left support stay 363L. The left support stay 363L is connected to the front surface of the post-planting frame 332, for example, by bolt fastening.

[0039] <3. Details of the pressing mechanism> Figure 10 is a perspective view when the above-described pressing mechanism 37 is viewed obliquely from the rear. The pressing mechanism 37 is provided to press the multi-sheet S guided by the sheet feeding guide portion 362 of the multi-sheet feeding and laying mechanism 36 against the surface H of the soil. Such a pressing mechanism 37 has a pressing roller 371 and a roller holding mechanism 372.

[0040] The pressing rollers 371 are arranged in two side by side in the left - right direction (see Fig. 11). The rotation axes of the respective pressing rollers 371 extend in the left - right direction. Each pressing roller 371 is arranged above the groove - processing part 381b of the grooving tool 381 of the sheet - under working body 38, which will be described later, and is arranged on both the left and right sides of the groove - processing part 381b in plan view.

[0041] The roller holding mechanism 372 rotatably holds the two pressing rollers 371. Such a roller holding mechanism 372 is composed of an arm part 372a, an arm support body 372b, and a biasing member 372c.

[0042] Two arm parts 372a are provided corresponding to each pressing roller 371. Each arm part 372a rotatably supports the rotation axis of the pressing roller 371. The arm support body 372b rotatably supports the two arm parts 372a. The biasing member 372c is composed of, for example, a spring. Two biasing members 372c are provided corresponding to each arm part 372a. One end of the biasing member 372c is fixed to the arm support body 372b. The other end of the biasing member 372c is connected to the end on the side opposite to the support side of the pressing roller 371 with the rotation axis of the arm part 372a interposed therebetween. Such a roller holding mechanism 372 is fixed to the left side surface of the planting case 33a, for example, by bolt fastening.

[0043] When the arm part 372a rotates by the biasing force of the biasing member 372c, each pressing roller 371 is pressed downward. Then, by each pressing roller 371, the multi - sheet S is pressed against the surface H of the soil. Thereby, tension is applied to the multi - sheet S. Therefore, when the cutter 322d (see Fig. 5 etc.) of the seedling planting mechanism 32 makes a hole in the multi - sheet S, the cutter 322d can easily pierce the multi - sheet S, and it becomes easy to make the hole with a predetermined size.

[0044] <4. Details of the sheet - under working body> FIG. 11 is a perspective view of the under-sheet working body 38 as viewed obliquely from the rear. As the traveling body 2 travels forward, the under-sheet working body 38 forms a groove G (see FIG. 14) in which seedlings are to be planted in the soil below the multi-sheet S fed out by the multi-sheet feeding and laying mechanism 36 prior to the planting of the seedlings. Such an under-sheet working body 38 includes a furrow opener 381 and a soil gathering mechanism 382.

[0045] The furrow opener 381 forms a groove G in which seedlings are to be planted in the soil prior to the planting of the seedlings by scraping a part of the soil (ridge) as the traveling body 2 travels. The furrow opener 381 is attached to the pre-planting frame 331 via an actuator support portion 300. The actuator support portion 300 is connected, for example, by bolt fastening to the right side of the frame support stay 361b (see FIG. 8) at the rear surface of the pre-planting frame 331. Thus, the transplanter 1 of the present embodiment includes an actuator support portion 300 that supports the under-sheet working body 38 (particularly the furrow opener 381). Further, since the furrow opener 381 is attached to the pre-planting frame 331 via the actuator support portion 300, it can be said that the under-sheet working body 38 having the furrow opener 381 is provided in the planting unit 3.

[0046] The furrow opener 381 has a main body portion 381a and a groove processing portion 381b. The main body portion 381a extends obliquely downward as it extends rearward from the supported side by the actuator support portion 300, and bends at a bending portion 381a1 and further extends rearward. When the seedlings are planted by the seedling planting mechanism 32, the rear side from the bending portion 381a1 in the furrow opener 381 is located below the surface H of the soil (ridge) (see FIG. 6).

[0047] The groove processing portion 381b is joined to the rear end of the main body portion 381a by, for example, welding. Therefore, when the seedlings are planted by the seedling planting mechanism 32, like a part of the main body portion 381a, the groove processing portion 381b is also located below the surface H of the soil (ridge) (see FIG. 6).

[0048] FIG. 12 is a perspective view showing an enlarged rear side of the furrow opener 381. The groove processing portion 381b of the furrow opener 381 has a V shape and is joined to the main body portion 381a at the root portion of the V. That is, the width of the groove processing portion 381b in the left-right direction widens as it goes backward from the joining side with the main body portion 381a. The maximum width in the left-right direction of the groove processing portion 381b (corresponding to the width W in FIG. 14) is wider than the width of the main body portion 381a in the left-right direction. Thereby, the width of the soil cut by the groove processing portion 381b becomes wider than the width of the soil cut by the main body portion 381a, and a groove G with an appropriate width for planting seedlings can be formed in the soil.

[0049] The soil gathering mechanism 382 shown in FIG. 11 gathers soil into the groove G as the traveling body 2 travels forward from the side of the groove G formed in the soil by the furrow opener 381. Such a soil gathering mechanism 382 has a backfilling member 383. The backfilling member 383 is a member that gathers and backfills soil into the groove G from the soil. The backfilling member 383 is attached to the main body portion 381a of the furrow opener 381 via a mounting bracket 382a.

[0050] FIG. 13 is a perspective view of the backfilling member 383 as viewed from the rear. The backfilling member 383 has a pair of rod-shaped portions 3831, a connecting portion 3832, and a pair of clamping portions 3833.

[0051] As shown in FIG. 11, the pair of rod-shaped portions 3831 are respectively located on the left and right sides with respect to the furrow opener 381. That is, the pair of rod-shaped portions 3831 are located on one side and the other side in the width direction perpendicular to the front-rear direction of the traveling body 2. And the pair of rod-shaped portions 3831 are located extending in the front-rear direction of the traveling body 2 in the soil.

[0052] The connecting portion 3832 is formed by bending a rod-shaped body into a U shape. Both ends of the connecting portion 3832 are respectively connected to the front end portions 3831a of the pair of rod-shaped portions 3831. Also, a part of the connecting portion 3832 is located above the soil (see FIG. 6).

[0053] The pair of clamping portions 3833 are respectively connected to the rear end portions 3831b of the pair of rod-shaped portions 3831, and the interval in the width direction becomes narrower as it goes backward. A flat plate 3833a is attached to the rear ends of the pair of clamping portions 3833 (the ends on the side opposite to the connection side with the pair of rod-shaped portions 3831) in order to enhance the efficiency of soil accumulation (to scrape as much soil as possible).

[0054] FIG. 14 is a plan view of the under-sheet working body 38. In FIG. 14, the groove G formed in the soil by the grooving device 381 and the state in which soil is accumulated in the groove G by the soil accumulation mechanism 382 (the backfill member 383) are shown together. In FIG. 14, for the sake of convenience, the illustration of the multi-sheet S covering the surface of the soil is omitted.

[0055] When the traveling body 2 is made to travel (move forward) with a part of the grooving device 381 (particularly the groove processing part 381b) and a part of the soil accumulation mechanism 382 (particularly the pair of rod-shaped parts 3831 and the pair of clamping parts 3833) being located in the soil, the groove processing part 381b of the grooving device 381 scrapes the soil with a predetermined width W. As a result, a groove G with a width W is formed in the soil below the multi-sheet S. Thereafter, the seedlings E are planted in the groove G by the seedling planting mechanism 32 (see FIG. 4 etc.). It should be noted that when the seedling planting mechanism 32 plants the seedlings E, holes are made in the multi-sheet S prior to planting, and the seedlings E are planted from above the multi-sheet S through the above-mentioned holes, as described above.

[0056] In the transplanter 1 of the present embodiment, the under-sheet working body 38 (particularly the grooving device 381) forms the groove G in the soil prior to the planting of the seedlings E. Therefore, even in a field where the soil is hard, the planting of the seedlings E into the soil (the groove G) can be facilitated. In particular, in the planting of vegetable seedlings E, from the viewpoint of heat preservation etc., a multi-sheet S made of a vinyl film is covered on the soil. Since the transplanter 1 of the present embodiment further includes a multi-sheet feeding and laying mechanism 36, the laying of the multi-sheet S and the formation of the groove G in the soil by the under-sheet working body 38 can be carried out in parallel while planting the vegetable seedlings E. Therefore, it is possible to realize a transplanter 1 suitable for planting vegetable seedlings E where the soil for planting the seedlings E is hard and the laying of the multi-sheet S is necessary.

[0057] The under-sheet actuator 38 has a furrow opener 381. As the furrow opener 381 scrapes a part of the soil as the traveling body 2 of the traveling machine travels, a furrow G for planting the seedling E is surely formed in the soil.

[0058] The under-sheet actuator 38 has a soil banking mechanism 382. In this configuration, after the seedling E is planted in the furrow G formed in the soil by the furrow opener 381, or almost simultaneously with the planting of the seedling E, the soil is filled back into the furrow G from the side by the soil banking mechanism 382 (particularly the pair of clamping portions 3833). Therefore, the root of the seedling E planted in the furrow G is covered with soil, and a good transplanting posture (planting posture) of the seedling E is stably maintained.

[0059] The soil banking mechanism 382 has a filling-back member 383. In this configuration, the seedling E planted in the furrow G is supported by the soil filled back into the furrow G by the filling-back member 383. For this reason, the seedling E is held in a stable posture in the soil.

[0060] The backfilling member 383 has a pair of rod-shaped parts 3831, a connecting part 3832, and a pair of clamping parts 3833. The pair of rod-shaped parts 3831 extend in the soil in the front-rear direction of the traveling body 2, and do not cross the width direction (left-right direction). Here, FIG. 15 is a cross-sectional view of the backfilling member 383 in FIG. 13 cut along the line A-A'. As shown in the figure, in a configuration in which each rod-shaped part 3831 extends in the front-rear direction in the soil, the projected area in the front-rear direction of each rod-shaped part 3831 is equal to the cross-sectional area (area of ​​the hatched part) of each rod-shaped part 3831, and is certainly smaller than the arrangement in which each rod-shaped part 3831 crosses the width direction. As a result, as the traveling body 2 travels, a groove much wider than the groove G made by the furrow maker 381 is formed by the backfilling member 383, and the risk of the posture of the planted seedling E becoming unstable is reduced. Therefore, even if the seedlings E planted are short, the seedlings E can be grown to pass through the holes in the mulch sheet S, reducing the risk that the seedlings E will not pass through the holes and will remain hidden under the mulch sheet S. In other words, since the backfilling member 383 does not cross the width direction of the traveling body 2 underground and a wide groove is not formed in the soil, even when short seedlings E are planted, the planting posture of the seedlings E can be stabilized and good planting can be achieved.

[0061] 14, in the soil piling mechanism 382, ​​the rear ends of the pair of clamping parts 3833 are located rearward of the planting position of the seedlings E. In this configuration, after the seedlings E are planted in the trench G, the pair of clamping parts 3833 reliably backfills the trench G with soil. Therefore, the seedlings E after planting are held in a stable position.

[0062] The soil piling mechanism 382 piles soil into the trench G from below the mulch sheet S. In this configuration, even when the mulch sheet S is laid on the soil surface H and seedlings E are planted, the soil piling mechanism 382 piles soil from below the mulch sheet S, making it possible to improve and stabilize the planting posture of the seedlings E.

[0063] In this embodiment, as described above, the actuator support portion 300 supports the under-sheet actuator 38. As shown in FIG. 11, the actuator support portion 300 is supported by the planting frame 33 (particularly the pre-planting frame 331) of the planting unit 3. And, as shown in FIG. 6, the actuator support portion 300 extends downward from the support side with the planting frame 33 (pre-planting frame 331) toward the lower side of the multi-sheet feeding and laying mechanism 36. As a result, the actuator support portion 300 is disposed below the multi-sheet S fed out from the multi-sheet feeding and laying mechanism 36.

[0064] In this configuration, the actuator support portion 300 is supported by the planting frame 33 so as not to impede the feeding of the multi-sheet S by the multi-sheet feeding and laying mechanism 36. And the under-sheet actuator 38 supported by the actuator support portion 300 penetrates into the soil below the multi-sheet S. Thereby, the groove G is surely formed in the soil by the grooving device 381 of the under-sheet actuator 38. Also, the soil return mechanism 382 of the under-sheet actuator 38 surely returns the soil to the groove G.

[0065] In this embodiment, the multi-sheet feeding and laying mechanism 36 and the under-sheet actuator 38 are provided in the planting unit 3. In this configuration, by the lifting mechanism 4, the multi-sheet feeding and laying mechanism 36 and the under-sheet actuator 38 can be lifted and lowered simultaneously with the lifting and lowering of the planting unit 3 with respect to the traveling machine body 2. Therefore, it is not necessary to provide a dedicated lifting mechanism for lifting and lowering the multi-sheet feeding and laying mechanism 36 and the under-sheet actuator 38 separately from the lifting mechanism 4 and perform lifting and lowering control separately from the planting unit 3. This leads to simplification of the configuration of the transplanter 1.

[0066] In addition, since the under-sheet actuator 38 is provided in the planting unit 3, it can be said that the soil gathering mechanism 382 of the under-sheet actuator 38 is also provided in the planting unit 3. In this configuration, even when the height of the planting unit 3 is adjusted according to the height of the soil ridge by the lifting mechanism 4, the position (height) of the soil gathering mechanism 382 can be changed following the planting unit 3 to keep the position of the soil gathering mechanism 382 with respect to the ridge surface (particularly the position in the height direction) constant. As a result, even if the height of the planting unit 3 changes according to the height of the ridge, the soil gathering by the soil gathering mechanism 382 is appropriately performed at a constant position with respect to the ridge surface.

[0067] <5. Details of the height detection mechanism> Next, the details of the height detection mechanism 39 will be described. FIG. 16 is a perspective view showing the configuration of the height detection mechanism 39. As shown in FIGS. 6 and 16, the height detection mechanism 39 detects the height (vertical position) of the soil surface H before the multi-sheet S is laid on the soil surface H by the multi-sheet feeding and laying mechanism 36 described above. The planting depth of the seedlings planted in the soil by the seedling planting mechanism 32 (see FIG. 2 etc.) is set to a predetermined depth with respect to the soil surface H. Therefore, the height of the soil surface H detected by the height detection mechanism 39 serves as a reference for setting the planting depth of the seedlings. Two such height detection mechanisms 39 are provided in the left-right direction. Each height detection mechanism 39 includes a lifting sensor 391 and a sensor support 392.

[0068] The lifting sensor 391 is supported by the sensor support 392 so as to be rotatable about the sensor rotation axis 391a. The sensor rotation axis 391a extends in the left-right direction. The sensor support 392 is supported by the lever support 352 of the planting depth adjustment mechanism 35 described later via a plurality of connecting members 393 so as to be vertically movable. The above lever support 352 is fixed to the pre-planting frame 331 of the planting unit 3 by bolt fastening. Therefore, it can be said that the height detection mechanism 39 having the sensor support 392 is provided in the planting unit 3 via the planting depth adjustment mechanism 35.

[0069] A locking piece 392a is provided at the upper front part of the sensor support 392. Further, a support shaft 391b extending in the left-right direction is provided in front of the sensor rotation shaft 391a of the lifting sensor 391. One end of a biasing spring 394 is connected to the locking piece 392a. The other end of the biasing spring 394 is fixed to the support shaft 391b. The lifting sensor 391 tends to rotate about the sensor rotation shaft 391a in the direction in which the front end rises due to the biasing force in the contracting direction of the biasing spring 394. As a result, the rear end side of the lifting sensor 391 is pressed against the surface H of the soil and always contacts the surface H of the soil. Therefore, when the height of the surface H of the soil changes, the lifting sensor 391 rotates about the sensor rotation shaft 391a following the change, and the height position of the rear end portion of the lifting sensor 391 changes.

[0070] The height detection mechanism 39 further includes a potentiometer 395 and a rotating stage 396. The potentiometer 395 detects the rotation angle of the rotating stage 396. The rotating stage 396 is connected by the tip of the lifting sensor 391 and a rod 397.

[0071] FIG. 17A is a side view of the height detection mechanism 39 as seen from the right when the lifting sensor 391 is in contact with the soil surface at height H1. FIG. 17B is an enlarged side view showing the height detection mechanism 39 of FIG. 17A. Further, FIG. 18A is a side view of the height detection mechanism 39 as seen from the right when the lifting sensor 391 comes into contact with the soil surface at height H2 (> H1). FIG. 18B is an enlarged side view showing the height detection mechanism 39 of FIG. 18A.

[0072] Due to variations in tillage or ridging, the height of the soil surface can change. For example, when the height of the soil surface changes from H1 to H2, the lifting sensor 391 in contact with the soil surface rotates about the sensor rotation shaft 391a. As a result, the rotating stage 396 connected via the lifting sensor 391 and the rod 397 rotates around the central axis of the potentiometer 395. FIG. 18B shows a state where the rotating stage 396 rotates clockwise from the state of FIG. 17B.

[0073] The rotation angle of the rotation station 396 corresponds to the rotation angle of the lifting sensor 391. Therefore, by detecting the rotation angle of the rotation station 396 by the potentiometer 395, the rotation angle of the lifting sensor 391 can be detected, and the height position of the lifting sensor 391 (particularly, the height position of the rear end portion of the lifting sensor 391 that contacts the soil surface) can be detected. That is, the height position of the soil surface that the lifting sensor 391 contacts can be detected. The potentiometer 395 outputs an electric signal corresponding to the detected rotation angle of the rotation station 396 (the rotation angle of the lifting sensor 391) to a controller 80 (see FIG. 28) described later. Thereby, the controller 80 can perform rolling control according to the above electric signal. The details of the rolling control will be described later.

[0074] As shown in FIG. 16 and the like, the height detection mechanism 39 further has a wire connection portion 398. One end portion of a lifting wire 400 (see FIG. 19) is fixed to the wire connection portion 398. The wire connection portion 398 penetrates through a locking piece 392a of the sensor support 392 and is fixed to the locking piece 392a.

[0075] The lifting wire 400 has a structure in which an inner wire passes through the inside of an outer wire. The outer wire is connected to the wire connection portion 398, and the inner wire passes through the wire connection portion 398 and is connected to a connecting spring 399. On the other hand, a locking portion 391c is provided in front of the support shaft 391b of the lifting sensor 391. The other end portion of the connecting spring 399, that is, the end portion of the connecting spring 399 on the side opposite to the connection portion with the lifting wire 400 is hooked on the locking portion 391c. Therefore, the lifting wire 400 is connected to the lifting sensor 391 via the connecting spring 399. For this reason, when the lifting sensor 391 rotates according to the change in the height of the soil surface, the lifting wire 400 (particularly, the inner wire) is pulled via the connecting spring 399.

[0076] In the present embodiment, the lifting control of the planting portion 3 by the lifting mechanism 4 (see FIG. 1) is performed according to the rotation operation of the lifting sensor 391 of the height detection mechanism 39. Hereinafter, the lifting control will be described.

[0077] FIG. 19 is an explanatory diagram schematically showing the configuration of the elevating mechanism 4. Here, for convenience of explanation, among the elevating sensors 391 of the height detection mechanism 39 provided in two side-by-side arrangements in the left-right direction, the elevating sensor 391 located on the right side is referred to as the right elevating sensor 391R, and the elevating sensor 391 located on the left side is referred to as the left elevating sensor 391L. Further, the elevating wire 400 connected to the right elevating sensor 391R via the connecting spring 399 is referred to as the right elevating wire 400R, and the elevating wire 400 connected to the left elevating sensor 391L via the connecting spring 399 is referred to as the left elevating wire 400L.

[0078] The elevating mechanism 4 includes an equalizer unit 45. The right elevating sensor 391R is connected to the equalizer unit 45 via the right elevating wire 400R. The left elevating sensor 391L is connected to the equalizer unit 45 via the left elevating wire 400L. The equalizer unit 45 is fixed to the support frame 2d of the traveling body 2 (see FIG. 1) via a coupler 45a. The equalizer unit 45 is a member that averages and outputs two inputs. A more detailed explanation of the equalizer unit 45 is as follows.

[0079] FIG. 20 is a perspective view schematically showing the configuration of the equalizer unit 45. In FIG. 20, for convenience, the illustration of the cover 450 (see FIG. 19) of the equalizer unit 45 is omitted. The equalizer unit 45 has left and right stays 451 and an elevating stay 452. The left and right stays 451 and the elevating stay 452 are each configured by flat plates extending in the left-right direction. The left and right stays 451 are located above the elevating stay 452.

[0080] The left and right stays 451 are rotatably connected to the lifting and lowering stay 452 via a first shaft portion 451a extending in the vertical direction. That is, the left and right stays 451 are relatively rotatable with respect to the lifting and lowering stay 452 about the first shaft portion 451a as the central axis. The first shaft portion 451a passes through the center in the left - right direction with respect to the left and right stays 451, and passes through a position on the left side of the second shaft portion 452a which serves as the rotation axis of the lifting and lowering stay 452 with respect to the lifting and lowering stay 452. The second shaft portion 452a extends in the vertical direction and is rotatably supported by a connecting member 45a (see FIG. 19). The above - mentioned right lifting wire 400R is connected to the right - hand end portion of the left and right stays 451. The above - mentioned left lifting wire 400L is connected to the left - hand end portion of the left and right stays 451. The lifting and lowering stay 452 is connected to a lifting and lowering valve 47 (see FIG. 19) via a connecting rod 46.

[0081] In the above configuration, for example, when the height of the soil surface changes from H1 to H2 (> H1), and both the left and right lifting sensors 391 rotate in response to this change (when the rear ends of both the left and right lifting sensors 391 rise), both the left and right lifting wires 400 (inner wires) are pulled, for example, rearward with respect to the equalizer unit 45 by the left and right lifting sensors 391.

[0082] FIG. 21 is a plan view schematically showing the behavior of the equalizer unit 45 when the left and right lifting wires 400 are pulled rearward. When both the left and right lifting wires 400 are pulled rearward, forces (tensile forces) are evenly applied to the left - hand end portion and the right - hand end portion of the left and right stays 451 of the equalizer unit 45. For this reason, the left and right stays 451 pull the first shaft portion 451a rearward with a force that equalizes the left and right tensile forces. As a result, the left - hand end portion of the lifting and lowering stay 452 rotates rearward about the second shaft portion 452a. Therefore, the connecting rod 46 connected to the lifting and lowering stay 452 is pulled rearward, adjusting the lifting and lowering valve 47 to change the supply amount and supply direction of the hydraulic oil from a hydraulic pump (not shown) to the lifting cylinder 43. As a result, the lifting cylinder 43 extends and the planting unit 3 rises.

[0083] Conversely, when the height of the soil surface changes from H2 to H1, the lifting and lowering operation opposite to the above is performed. That is, when the rear ends of the left and right lifting sensors 391 both descend, the tension of the left and right lifting wires 400 is loosened, and the pulling of the left and right stays 451 of the equalizer section 45 backward is equally loosened on both sides. As a result, since the pulling of the first shaft portion 451a by the left and right stays 451 weakens, the left end portion of the lifting stay 452 rotates forward about the second shaft portion 452a (more than the state in the lower diagram of FIG. 21). Then, the connecting rod 46 acts on the lifting valve 47 to change the supply amount and supply direction of the hydraulic oil from the hydraulic pump to the lifting cylinder 43. As a result, the lifting cylinder 43 contracts and the planting unit 3 descends.

[0084] By raising and lowering the planting unit 3 in response to the change in the height of the soil surface in this way, even if the height of the soil surface changes, the planting unit 3 can be positioned so as to have a predetermined planting depth with respect to the soil surface, and seedlings can be planted in the soil.

[0085] On the other hand, if the height of the soil surface is different in the left - right direction, the rotation amounts of the left and right lifting sensors 391 may be different. For example, when the left lifting sensor 391L rises and the right lifting sensor 391R descends, the rotation amounts of the left and right lifting sensors 391 are different. In this case, the left lifting wire 400L is pulled backward, and the tension of the right lifting wire 400R is loosened.

[0086] FIG. 22 is a plan view schematically showing the behavior of the equalizer unit 45 when the left lifting wire 400L is pulled backward and the tension of the right lifting wire 400R is relaxed. The left end of the left and right stays 451 of the equalizer unit 45 is pulled backward by the left lifting wire 400L. On the other hand, the pulling of the right end of the left and right stays 451 by the right lifting wire 400R backward is less than that of the left end. For this reason, the left and right stays 451 rotate with the first shaft portion 451a as the center and the left end rotates to the rear side. Due to this rotation, the force acting on the first shaft portion 451a from the left and right stays 451 becomes almost zero. For this reason, the lifting stay 452 hardly rotates, and hardly any pulling force of the connecting rod 46 backward occurs. As a result, the lifting cylinder 43 hardly expands and contracts, and the lifting operation of the planting unit 3 is not substantially performed. Instead, in this embodiment, rolling control described later is performed.

[0087] In this embodiment, the height detection mechanism 39 detects the height of the surface of the soil (for example, a ridge) before the multi-sheet S is laid on the soil (see FIG. 6 and the like). For this reason, even when the surface H of the ridge of the soil (for example, a field) is not flat and the height of the ridge changes in the traveling direction (front-rear direction) of the traveling machine body 2, the height detection mechanism 39 can accurately detect the height of the ridge following the change in the height of the ridge. Therefore, according to the detected height of the ridge, the lifting mechanism 4 can lift and control the planting unit 3 as described above and plant the seedlings in the ridge at a predetermined planting depth. More specifically, it is as follows.

[0088] For example, FIG. 23 shows a configuration in which the height detection mechanism 39 detects the height of the soil surface H after the multi-sheet S is laid on the soil surface H. As shown in the figure, when there are irregularities on the soil surface H in the front-rear direction in which the traveling machine body 2 travels, since the multi-sheet S is stretched over the recessed portion HR, the height detection mechanism 39 may detect the height of the multi-sheet S covering the recessed portion HR and misdetect this as the height of the soil surface H.

[0089] In this embodiment, as shown in FIG. 24, before the multi-sheet S is laid on the surface H of the soil, the height detection mechanism 39 detects the height of the surface H of the soil. Therefore, even if there are irregularities on the surface H of the soil, the height detection mechanism 39 can detect the height (bottom) of the concave portion HR and accurately detect this as the height of the surface H of the soil. As a result, it becomes possible to plant seedlings at a predetermined planting depth based on the detected height of the surface H of the soil.

[0090] Further, in the configuration where the height detection mechanism 39 detects the height of the surface H of the soil before the multi-sheet S is laid, the height detection mechanism 39 can be arranged on the side opposite to the seedling planting mechanism 32 with respect to the multi-sheet feeding and laying mechanism 36 (on the front side in the traveling direction). Thereby, it becomes possible to narrow the space in the front-rear direction between the multi-sheet feeding and laying mechanism 36 and the seedling planting mechanism 32. In other words, it becomes possible to arrange the seedling planting mechanism 32 as close as possible to the multi-sheet feeding and laying mechanism 36 in front of it. As a result, it becomes easy to shorten the overall length of the transplanter 1 and miniaturize the transplanter 1 in the front-rear direction.

[0091] Also, for example, when the height detection mechanism 39 is provided on the traveling body 2 side, when the traveling body 2 is displaced in the vertical direction due to irregularities on the traveling surface (the grounding surfaces of the front wheels 1a and the rear wheels 1b) during traveling, the height detection mechanism 39 also follows and is displaced in the vertical direction. For this reason, even if there are irregularities on the ridge surface, it becomes difficult for the height detection mechanism 39 to accurately detect the irregularities on the ridge surface (because the influence of the vertical displacement of the traveling body 2 is added to the detection result by the height detection mechanism 39).

[0092] In this embodiment, since the height detection mechanism 39 is provided in the planting unit 3 that is connected to the traveling body 2 so as to be vertically movable, even when the traveling body 2 is displaced in the vertical direction, the height detection mechanism 39 can be moved up and down together with the planting unit 3 to allow the height detection mechanism 39 to detect the irregularities on the surface of the soil. Therefore, it is possible to suppress the influence of the vertical displacement of the traveling body 2 on the detection result by the height detection mechanism 39. That is, it is possible to suppress a decrease in the detection accuracy of the height of the surface of the soil by the height detection mechanism 39 due to the vertical displacement of the traveling body 2.

[0093] <Details of the Planting Depth Adjustment Mechanism> Next, the details of the planting depth adjustment mechanism 35 shown in Fig. 16 will be described. The planting depth adjustment mechanism 35 is a mechanism that adjusts the planting depth of the seedlings by adjusting the installation height of the height detection mechanism 39 with respect to the planting unit 3. Such a planting depth adjustment mechanism 35 includes a planting depth adjustment lever 351 and a lever support 352.

[0094] The planting depth adjustment lever 351 is supported by the lever support 352 so as to be rotatable within a plane perpendicular to the left - right direction. The lever support 352 is fixed to the upper surface of the pre - planting frame 331 of the planting unit 3 by means such as bolt fastening. A multi - stage groove portion 352a for supporting the planting depth adjustment lever 351 is formed in the lever support 352. By fitting the planting depth adjustment lever 351 into any position of the groove portion 352a, the planting depth adjustment lever 351 can be held at a predetermined rotation position. Further, the planting depth adjustment lever 351 is connected to the sensor support 392 of the height detection mechanism 39 via a support member 353. The support member 353 is supported so as to be rotatable with respect to the sensor support 392.

[0095] Fig. 25 is a side view schematically showing the state in which the height detection mechanism 39 (particularly the lifting sensor 391) moves up and down due to the rotation of the planting depth adjustment lever 351. As shown in the right figure of Fig. 25, when the planting depth adjustment lever 351 is rotated upward, the sensor support 392 moves upward via the support member 353. Therefore, the lifting sensor 391 supported by the sensor support 392 moves upward. In this case, the position of the seedling planting mechanism 32 (see Fig. 2 etc.) with respect to the lifting sensor 391, that is, the position of the seedling planting mechanism 32 with respect to the surface of the soil that the lifting sensor 391 contacts, relatively decreases. For this reason, the planting of the seedlings by the seedling planting mechanism 32 becomes deep planting. That is, the planting position of the seedlings becomes deeper with respect to the surface of the soil.

[0096] Conversely, as shown in the left diagram of Fig. 25, when the planting depth adjustment lever 351 is rotated downward, the sensor support 392 moves downward via the support member 353. Therefore, the lifting sensor 391 supported by the sensor support 392 moves downward. In this case, since the position of the seedling planting mechanism 32 relative to the lifting sensor 391 rises, the seedlings are planted shallowly by the seedling planting mechanism 32. That is, the planting position of the seedlings becomes shallower with respect to the surface of the soil.

[0097] In this way, by providing the transplanting machine 1 with the planting depth adjustment mechanism 35, the vertical position of the lifting sensor 391 can be adjusted by rotating the planting depth adjustment lever 351. That is, the adjustment of the planting depth can be realized with a simple configuration that adjusts the installation height of the height detection mechanism 39.

[0098] <7. Regarding the rolling control of the planting unit> Fig. 26 is a perspective view of the planting unit 3 of the transplanting machine 1 of the present embodiment as viewed from the front. Fig. 27 is a perspective view showing an excerpt of the roll mechanism 60 shown in Fig. 26. In the transplanting machine 1 of the present embodiment, as described above, two height detection mechanisms 39 are provided side by side in the left-right direction. That is, a plurality of height detection mechanisms 39 are provided in the width direction of the traveling machine body 2.

[0099] Further, the transplanting machine 1 includes a roll mechanism 60. The roll mechanism 60 is a rotation mechanism that rotates the planting unit 3 with respect to the traveling machine body 2. The roll rotation axis 61 that serves as the rotation axis of the planting unit 3 extends in the front-rear direction of the traveling machine body 2. The roll rotation axis 61 is accommodated in the axis housing portion 62 of the roll mechanism 60. The axis housing portion 62 is supported by the traveling machine body 2. Further, the roll rotation axis 61 is connected to the frame connection portion 64 via the rotation axis connection portion 63. The frame connection portion 64 connects the upper frame 335 and the horizontal frame 336 of the planting frame 33, and also connects the horizontal frame 336 and the rotation axis connection portion 63.

[0100] The roll mechanism 60 has a rolling cylinder 65. The rolling cylinder 65 is a hydraulic cylinder that expands and contracts in the left - right direction. The cylinder body 65a of the rolling cylinder 65 is held by the above - mentioned shaft housing portion 62. The tip of the rod 65b that expands and contracts in the left - right direction with respect to the cylinder body 65a is connected to the frame connection portion 64.

[0101] In FIG. 27, when the rod 65b is moved (extended) in the left direction L1 with respect to the cylinder body 65a of the rolling cylinder 65, the frame connection portion 64, together with the planting frame 33, rotates in the D1 direction with respect to the traveling machine body 2 about the roll rotation axis 61. That is, the planting portion 3 having the planting frame 33 rotates in the D1 direction. Conversely, when the rod 65b is moved (contracted) in the right direction R1 with respect to the cylinder body 65a, the frame connection portion 64, together with the planting frame 33, rotates in the D2 direction with respect to the traveling machine body 2 about the roll rotation axis 61. That is, the planting portion 3 rotates in the D2 direction. Thus, the planting portion 3 is rotatably supported with respect to the traveling machine body 2 about the roll rotation axis 61. Hereinafter, the rotation directions (D1 direction, D2 direction) of the planting portion 3 about the roll rotation axis 61 extending in the front - rear direction are also referred to as the roll direction.

[0102] FIG. 28 is a block diagram schematically showing a configuration related to the rolling control of the transplanter 1 of the present embodiment. The transplanter 1 includes a controller 80. The controller 80 is composed of an electronic control unit, also called an ECU (Electronic Control Unit) for example, and performs electrical control of each part of the transplanter 1. In particular, the controller 80 functions as an inclination detection unit that detects the relative inclination of the planting portion 3 in the roll direction, that is, the relative inclination around the roll rotation axis 61, with respect to the soil surface based on the difference in the output values of the two height detection mechanisms 39 provided in the width direction of the traveling machine body 2.

[0103] Here, the potentiometer 395 of the height detection mechanism 39 on the left side is designated as the left potentiometer 395L, and the potentiometer 395 of the height detection mechanism 39 on the right side is designated as the right potentiometer 395R. As described above, the left potentiometer 395L and the right potentiometer 395R output electrical signals corresponding to the rotation angle of the rotation stage 396 shown in FIG. 16 etc., that is, the rotation angle of the lifting sensor 391, to the controller 80. The controller 80 detects the difference in the rotation angle of each lifting sensor 391 based on the electrical signals output from the left potentiometer 395L and the right potentiometer 395R. The difference in the rotation angle becomes the relative inclination (angle) in the roll direction of the planting part 3 with respect to the surface of the soil.

[0104] When the inclination in the roll direction of the planting part 3 is detected, the controller 80 controls the roll mechanism 60 to rotate the planting part 3 in a direction in which the inclination of the planting part 3 with respect to the surface of the soil becomes smaller. Specifically, the controller 80 outputs an electrical signal to the rolling control valve 66 to change the supply amount and supply direction of the hydraulic oil from a hydraulic pump (not shown) to the rolling cylinder 65. Thereby, the rolling cylinder 65 expands and contracts in the left - right direction, and it becomes possible to rotate the planting part 3 in the roll direction as shown in FIG. 27. The above - mentioned rolling control valve 66 is composed of, for example, a solenoid valve and is electrically connected to the controller 80.

[0105] FIG. 29 schematically shows an example of rolling control based on the result of inclination detection by the controller 80. In FIG. 29, the magnitude of the rotation angle of the lifting sensors 391 of the left and right height detection mechanisms 39 is shown corresponding to the vertical interval between the lifting sensors 391. That is, the wider the vertical interval between the lifting sensors 391, the larger the rotation angle of the lifting sensors 391. Also, it is assumed that the ground contact surfaces (the running surfaces on the outer side in the width direction of the ridge) of the front wheels 1a and the rear wheels 1b of the transplanter 1 are horizontal in the left - right direction.

[0106] As shown in the upper diagram of FIG. 29, when the height of the soil surface H is constant in the left-right direction (when the surface H is horizontal in the left-right direction), the rotation angles of the left lifting sensor 391L and the right lifting sensor R are the same. As shown in the middle diagram of FIG. 29, when the soil surface H slopes downward to the lower right, the rotation angle of the right lifting sensor 391R becomes larger than the rotation angle of the left lifting sensor 391L. In this state, when seedlings are planted by the planting unit 3, the planting depth with respect to the soil surface H varies depending on the position in the left-right direction. Therefore, for example, when planting two rows of seedlings in one furrow, the planting depth of the seedlings on the right side becomes shallower than that of the seedlings on the left side. For this reason, in the present embodiment, the roll mechanism 60 rotates the planting unit 3 in a direction in which the difference in the rotation angles of the left lifting sensor 391L and the right lifting sensor R becomes smaller.

[0107] That is, as shown in the lower diagram of FIG. 29, the roll mechanism 60 rotates the planting unit 3 in the roll direction so that the rotation angle of the right lifting sensor 391R approaches the rotation angle of the left lifting sensor 391L. As a result, the planting unit 3 becomes parallel to the soil surface H, and even when planting two rows of seedlings in one furrow, the planting depth of the seedlings can be made the same for the two rows on the left and right.

[0108] As described above, since the transplanter 1 is provided with the controller 80 as the inclination detection unit, even when the soil surface H is inclined in the roll direction with respect to the traveling direction of the traveling machine body 2, based on the relative inclination detection of the planting unit 3 by the controller 80, it is possible to perform rolling control to keep the ground angle of the planting unit 3 constant (position the planting unit 3 parallel to the soil surface H).

[0109] In particular, the roll mechanism 60 rotates the planting unit 3 in a direction in which the difference in the output values of each height detection mechanism 39 (corresponding to the difference in the rotation angles of the left lifting sensor 391L and the right lifting sensor R) becomes smaller based on the inclination of the planting unit 3 in the roll direction detected by the controller 80. Thereby, even when the soil surface H is inclined in the roll direction, it becomes possible to plant a plurality of rows of seedlings with the same planting depth for each row.

[0110] Incidentally, the rolling control described above is also applicable when planting seedlings in a flat field or a field without ridges. Also, in the above description, the configuration and control for rotating the planting unit 3 in the roll direction around a specific rotation axis, i.e., the roll rotation axis 61, have been described. However, the rolling control of the present embodiment is applicable to other configurations as well. For example, it is possible to apply the rolling control described in the present embodiment to a configuration in which the planting unit 3 is supported so as to be able to move up and down by a three-point link method and is also supported so as to be able to rotate in the roll direction.

[0111] <9. Supplementary Note> The transplanter described in the present embodiment can also be expressed as the transplanter shown in the following supplementary note.

[0112] The transplanter of Supplementary Note (1) is a traveling machine body, a seedling planting mechanism for planting seedlings in the soil, and a planting unit that is connected to the rear of the traveling machine body so as to be able to move up and down, a multi-sheet feeding and laying mechanism for feeding and laying a multi-sheet on the surface of the soil before planting the seedlings, and is a transplanter comprising a height detection mechanism for detecting the height of the surface of the soil, which serves as a reference for setting the planting depth of the seedlings, before the multi-sheet is laid on the surface of the soil.

[0113] The transplanter of Supplementary Note (2) is the transplanter described in Supplementary Note (1), wherein the height detection mechanism is provided on the planting unit.

[0114] The transplanter of Supplementary Note (3) is the transplanter described in Supplementary Note (1) or (2), wherein it further comprises a planting depth adjustment mechanism for adjusting the planting depth of the seedlings by adjusting the installation height of the height detection mechanism with respect to the planting unit.

[0115] The transplanter of Supplementary Note (4) is the transplanter described in any one of Supplementary Notes (1) to (3), wherein a plurality of the height detection mechanisms are provided in the width direction of the traveling machine body, The planting unit is supported so as to be rotatable in the roll direction with respect to the traveling machine body. The transplanter further includes an inclination detection unit that detects the relative inclination of the planting unit in the roll direction with respect to the surface of the soil based on the difference in the output values of each height detection mechanism.

[0116] The transplanter according to supplementary note (5) is the transplanter according to supplementary note (4), further includes a rotation mechanism that rotates the planting unit in a direction in which the difference in the output values of each height detection mechanism becomes smaller based on the inclination of the planting unit detected by the inclination detection unit.

[0117] As described above, the embodiments of the present invention have been described, but the scope of the present invention is not limited thereto, and it can be implemented with expansion or modification without departing from the gist of the invention.

Industrial Applicability

[0118] The transplanter of the present invention can be used, for example, for a transplanter that plants vegetable seedlings in soil (ridges).

Explanation of Signs

[0119] 1 Transplanter 2 Traveling machine body 3 Planting unit 32 Seedling planting mechanism 33 Planting frame 35 Planting depth adjustment mechanism 36 Multi-sheet feeding and laying mechanism 39 Height detection mechanism 60 Roll mechanism (rotation mechanism) 61 Roll rotation shaft 80 Controller (inclination detection unit) E Seedling H Surface S Multi-sheet

Claims

1. A traveling body, a planting unit having a seedling planting mechanism for planting seedlings in the soil and being connected to the rear of the traveling body so as to be vertically movable, a multi-sheet feeding and laying mechanism for feeding and laying a multi-sheet on the surface of the soil before planting the seedlings, and a transplanter comprising: a height detection mechanism for detecting the height of the surface of the soil serving as a reference for setting the planting depth of the seedlings before the multi-sheet is laid on the surface of the soil.

2. The transplanter according to claim 1, wherein the height detection mechanism is provided on the planting unit.

3. The transplanter according to claim 1, further comprising a planting depth adjustment mechanism for adjusting the planting depth of the seedlings by adjusting the installation height of the height detection mechanism with respect to the planting unit.

4. a plurality of the height detection mechanisms are provided in the width direction of the traveling body, the planting unit is supported so as to be rotatable in the roll direction with respect to the traveling body, the transplanter further comprises an inclination detection unit for detecting the relative inclination of the planting unit in the roll direction with respect to the surface of the soil based on the difference in the output values of the respective height detection mechanisms.

5. The transplanter according to claim 4, further comprising a rotation mechanism for rotating the planting unit in a direction in which the difference in the output values of the respective height detection mechanisms becomes smaller based on the inclination of the planting unit detected by the inclination detection unit.

Images