Traction working device and work vehicle

Abstract

To provide a traction type work device in which maintainability of a device body can be improved, and a work vehicle.SOLUTION: A traction type work device 1 includes a device body 3. The device body 3 is connected to a vehicle body of a work vehicle and towed by the vehicle body. The vehicle body 3 includes a work unit (dissemination unit 5) and a support part 7 that supports the work unit. The support part 7 supports the work unit in a rotatable manner between a first posture in which a target surface 50 of the work unit faces further upward than the horizontal and a second posture in which the target surface 50 faces further downward than the horizontal.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present invention relates to a towed working device and a work vehicle, which include a device body connected to a vehicle body of a work vehicle and towed by the vehicle body.

Background Art

[0002] As related art, a towed working device including a device body such as a wheel track eraser device and a work unit (direct seeding device) connected to the rear side of a work vehicle is known (see, for example, Patent Document 1). In the related art, a connection mechanism such as a three-point link mechanism capable of connecting a device body (such as a wheel track eraser device) is provided on the rear side of a vehicle body (a vehicle body part) of a work vehicle. By using the connection mechanism, the device body (such as a wheel track eraser device) is equipped on the work vehicle.

[0003] The device body (wheel track eraser device) of the towed working device according to the related art includes a pair of left and right earth-accumulating bodies on the device body. The pair of left and right earth-accumulating bodies are configured in an inclined posture in which the rear side portions approach each other in the left-right direction. According to this towed working device, it is possible to erase the wheel track by accumulating soil with the pair of left and right earth-accumulating bodies at the location where the wheels of a work vehicle such as a tractor have passed. In addition, as the work vehicle moves forward, the work unit discharges the seeds stored in the hopper little by little and directly seeds the seeds in the field.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the configuration of the related art described above, since the posture of the apparatus main body with respect to the vehicle main body is fixed, for example, when performing maintenance by discharging all the seeds remaining in the hopper after the work is completed, it takes time to discharge the seeds and it may take time to perform maintenance on the apparatus main body.

[0006] An object of the present invention is to provide a towed working device and a work vehicle capable of improving the maintainability of the apparatus main body.

Means for Solving the Problems

[0007] A towed working device according to one aspect of the present invention includes an apparatus main body. The apparatus main body is connected to a vehicle main body of a work vehicle and towed by the vehicle main body. The apparatus main body has a working unit and a support unit that supports the working unit. The support unit rotatably supports the working unit between a first posture in which a target surface of the working unit faces upward from the horizontal and a second posture in which the target surface faces downward from the horizontal.

[0008] A work vehicle according to another aspect of the present invention includes the towed working device and the vehicle main body.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a towed working device and a work vehicle capable of improving the maintainability of the apparatus main body.

Brief Description of the Drawings

[0010]

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Figure 13

[0011] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiments are an example of embodying the present invention and are not intended to limit the technical scope of the present invention. Also, in the accompanying drawings, for example, illustrations of fasteners such as screws, bolts, or nuts, various cover members, and the detailed shapes of each part are appropriately omitted.

[0012] (Embodiment 1) [1] Overall Configuration First, the overall configuration of the work vehicle 10 according to this embodiment will be described with reference to FIG. 1. The towed work device 1 according to this embodiment constitutes the work vehicle 10 together with the vehicle body 2 of the work vehicle 10. That is, the work vehicle 10 includes a towed work device 1 (hereinafter also simply referred to as the "work device 1") and a vehicle body 2.

[0013] The work device 1 includes a device main body 3 and a connecting device 4. The device main body 3 is connected to the vehicle body 2 of the work vehicle 10 and towed by the vehicle body 2. The connecting device 4 connects the device main body 3 and the vehicle body 2. Here, the connecting device 4 connects the device main body 3 to the rear side of the vehicle body 2 (the side opposite to the forward direction of the vehicle body 2). That is, the (towed) work device 1 is a device that is connected to the rear side of the vehicle body 2 and is towed by the vehicle body 2 when the vehicle body 2 moves forward, and moves forward together with the vehicle body 2. In particular, in this embodiment, the work device 1 does not have a power source that generates power by itself, and performs work using the force towed by the vehicle body 2.

[0014] The "work vehicle" as used in the present disclosure means a vehicle that performs various operations in a work area such as a farm field G1. As an example, it is an agricultural machine (agricultural machinery) such as a tractor, a seeder, a rice transplanter, a sprayer, a mist sprayer, a transplanter, and a harvester. The work vehicle 10 may be, for example, a construction machine (construction machinery). In this embodiment, unless otherwise specified, the case where the work vehicle 10 is a riding-type tractor equipped with a seeder will be described as an example. That is, the work vehicle 10 is configured by connecting the work device 1 as a seeder to the tractor as the vehicle body 2 in a towable state. In this work vehicle 10, by the vehicle body 2 traveling in a work area such as the farm field G1, it is possible to perform a seeding operation of sowing crop seeds on the locus of the vehicle body 2 in the work area. Further, in this embodiment, as an example, the work vehicle 10 is operated by an operation (including remote operation) of a person (operator), but is not limited thereto, and the work vehicle 10 may be a drone that operates by autonomous driving.

[0015] As used in the present disclosure, the "field" refers to a work area where various operations such as seeding, fertilizing, pesticide spraying, planting (rice transplanting), or harvesting are performed while the work vehicle 10 is moving, and includes paddy fields, farmlands, orchards, pastures, etc. for cultivation. For example, when a paddy field or a farmland where crops (agricultural products) such as rice, wheat, soybeans, or buckwheat are grown is the field G1, the crops grown in the field G1 are agricultural products. Further, when growing nursery stock in a nursery, the nursery is the field G1, and when growing trees that become timber in a forest as in forestry, the forest is the field G1. In this case, the crops grown in the field G1 are nursery stock, trees, etc. In the present embodiment, unless otherwise specified, the work vehicle 10 is used for the seeding operation of rice seeds (rice seeds), and the case where the field G1 is a paddy field for growing rice will be described as an example. Also, the work area is not limited to the field G1. For example, if the work vehicle 10 is a construction machine, the site where the construction machine performs work is the work area.

[0016] In the present embodiment, for convenience of explanation, the vertical direction in a state where the work vehicle 10 can be used is defined as the up-down direction D1. Based on the direction seen from a person (operator) riding on the vehicle body 2 (the driving part 21) of the work vehicle 10, the front-back direction D2 and the left-right direction D3 (see FIG. 2) are defined. The left side of the left-right direction D3 refers to the left side when the vehicle body 2 travels (moves forward) forward, and the right side of the left-right direction D3 refers to the right side when the vehicle body 2 travels (moves forward) forward. The outer side of the left-right direction D3 refers to the outer side of the work vehicle 10 in the left-right direction D3, and the inner side of the left-right direction D3 refers to the inner side of the work vehicle 10 in the left-right direction D3. However, these directions are not intended to limit the usage direction (direction during use) of the work vehicle 10 and the work device 1.

[0017] The vehicle body 2 has a driver's cab 21, front wheels 22, and rear wheels 23. The vehicle body 2 further has a power source (such as an engine or a motor) and a control device, etc. The driver's cab 21 can be boarded by a person (operator). A steering device, a transmission device, an operating device, etc. are arranged in the driver's cab 21. The front wheels 22 and the rear wheels 23 are provided, for example, in a pair on each of the left and right sides. And the vehicle body 2 is configured to be able to travel by driving the rear wheels 23 with the power generated by the power source. Here, the front wheels 22 function as steering wheels, enabling turning in the left-right direction D3. Thereby, the vehicle body 2 can travel so as to move in the front-rear direction D2 and the left-right direction D3 within the field G1 according to the operation of the person boarding the driver's cab 21. For example, the vehicle body 2 performs seeding work while meandering within the field G1.

[0018] As described above, the working device 1 is connected to the rear side of the vehicle body 2. In the present embodiment, the working device 1 is detachably connected to the vehicle body 2, and it is also possible to connect a device different from the working device 1 to the vehicle body 2.

[0019] In the present embodiment, since the working vehicle 10 can perform seeding work of sowing seeds (paddy seeds) in a field G1 consisting of paddy fields, the device body 3 of the working device 1 has at least a seeding unit 5 corresponding to the seeding work. Further, the device body 3 has a wheel track eraser 6 for erasing the tracks of the wheels (front wheels 22 and rear wheels 23) of the vehicle body 2. That is, the device body 3 of the working device 1 has a function of erasing wheel tracks and a seeding function. These seeding unit 5 and wheel track eraser 6 are arranged in the order of the wheel track eraser 6 and the seeding unit 5 from the front side in a state of being connected to the vehicle body 2.

[0020] As shown in FIG. 1, a three-point link mechanism including a pair of left and right lower links 24 and an upper link 25 is provided at the rear of the vehicle body 2 of the work vehicle 10, and the connecting device 4 of the work device 1 can be connected to the three-point link mechanism. The upper link 25 is located at the center in the left-right direction D3 and above the pair of lower links 24. The connecting device 4 connects the device main body 3 to the three-point link mechanism (a pair of lower links 24 and an upper link 25), thereby realizing the connection of the work device 1 to the vehicle body 2. Another device different from the work device 1 according to the present embodiment can also be connected to the three-point link mechanism (a pair of lower links 24 and an upper link 25). With this configuration, even without using a dedicated seeding machine, it is possible to perform a submerging direct seeding operation of directly sowing seeds (paddy seeds) on a paddy field G1 using a general-purpose vehicle body 2.

[0021] In the present embodiment, the work vehicle 10 particularly performs "spot seeding" of sowing an appropriate amount of seeds at a predetermined interval along the rows set in the field G1 during the direct seeding operation. That is, while the vehicle body 2 travels along the rows in the field G1, by performing a seeding (spot seeding) operation with the work device 1, seeds can be sown at a predetermined interval in the front-rear direction D2 and at positions separated by the row spacing in the left-right direction D3. Here, a lifting device having a hydraulic cylinder or the like may be provided at the rear of the vehicle body 2, and the position of the work device 1 in the up-down direction D1 may be configured to be adjustable by lifting and lowering the three-point link mechanism with the lifting device.

[0022] [2] Configuration of the work device Next, the configuration of the (traction type) work device 1 according to the present embodiment will be described in detail with reference to FIGS. 2 to 8.

[0023] The working device 1 according to this embodiment includes a device main body 3 and a connecting device 4 that connects the device main body 3 and the vehicle main body 2. As described above, the device main body 3 has the wheel mark eraser 6 and the seeding unit 5. Here, since the seeding unit 5 is a unit for performing seeding work, it is an example of a "working unit" that performs some work. Also, since seeding work is an example of spraying work for spraying seeds as a sprayed material, the seeding unit 5 is also an example of a "spraying unit" that performs spraying work of a sprayed material (here, seeds). In this embodiment, the device main body 3 has one wheel mark eraser 6 and a plurality (five as an example) of seeding units 5 (a plurality of working units).

[0024] By the way, the plurality of seeding units 5 (a plurality of working units) are arranged side by side in the left - right direction D3 and are connected to the wheel mark eraser 6 by the support portion 7. Here, a plurality (five as an example) of support portions 7 are provided corresponding to the plurality of seeding units 5, and one seeding unit 5 is connected to the connecting device 4 by one support portion 7. That is, the device main body 3 has a support portion 7 in addition to the wheel mark eraser 6 and the seeding unit 5 as a working unit. The support portion 7 supports the working unit (seeding unit 5). And, although it will be described in detail later, the support portion 7 rotatably supports the working unit (seeding unit 5) between a first posture in which the target surface 50 (see FIG. 2) of the working unit (seeding unit 5) is directed upward from the horizontal and a second posture in which the target surface 50 is directed downward from the horizontal.

[0025] [2.1] Configuration of the connecting device The connecting device 4 is coupled to a three - point link mechanism (a pair of lower links 24 and an upper link 25) provided at the rear part of the vehicle main body 2 of the work vehicle 10, thereby connecting the device main body 3 to the rear side of the vehicle main body 2. In FIGS. 2 and 3, the pair of lower links 24 and the upper link 25 are shown by imaginary lines (two - dot chain lines). In this embodiment, the components of the connecting device 4 are basically made of metal, and the material is selected according to the required strength, weather resistance, etc. However, the components of the connecting device 4 are not limited to being made of metal, and for example, resin or wood may be appropriately used.

[0026] The connecting device 4 has a support mechanism 41. The support mechanism 41 supports the apparatus main body 3 in a state where the apparatus main body 3 is movable in the vertical direction D1 in response to an external force while restricting movement of the apparatus main body 3 other than in the vertical direction D1. In the present embodiment, the support mechanism 41 supports the wheel mark erasing device 6 (land leveling body 62) of the apparatus main body 3, so that the wheel mark erasing device 6 together with the plurality of seeding units 5 connected to the wheel mark erasing device 6 moves in the vertical direction D1. In this way, the connecting device 4 supports the apparatus main body 3 (the wheel mark erasing device 6 and the plurality of seeding units 5) in a state where the apparatus main body 3 is movable in the vertical direction D1 in response to an external force.

[0027] The support mechanism 41 has an arm member 42 and a lifting member 43. Further, the connecting device 4 further has a biasing portion 44 and a guide member 45.

[0028] The arm member 42 is rotatably connected to a (pair of) lower links 24 provided at the rear portion of the vehicle body 2 at a first fulcrum 421. The support mechanism 41 moves the apparatus main body 3 in the vertical direction D1 as the arm member 42 rotates about the first fulcrum 421. Specifically, the support mechanism 41 has a pair of arm members 42 spaced apart in the left - right direction D3 so as to correspond to the pair of left - right lower links 24. Each arm member 42 is a long - shaped member having a length in one direction, and has a first fulcrum 421 at one end portion (here, the front end portion) in its longitudinal direction. Further, each arm member 42 has a second fulcrum 422 at the end portion (here, the rear end portion) opposite to the first fulcrum 421.

[0029] The elevating member 43 is a member rotatably connected to the arm member 42 at the second fulcrum 422, and moves in the vertical direction D1 as the arm member 42 rotates. Here, the elevating member 43 is rotatably connected to an upper link 25 provided at the rear part of the vehicle body 2 at a fourth fulcrum 434. Thereby, even when the elevating member 43 moves up and down, the elevating member 43 moves (parallel) while maintaining the posture of the elevating member 43 with respect to the horizontal plane. By coupling the apparatus main body 3 to such an elevating member 43, the apparatus main body 3 can also move in the vertical direction D1 while maintaining the posture of the apparatus main body 3 with respect to the horizontal plane.

[0030] That is, in the present embodiment, the support mechanism 41 causes the elevating member 43 to move up and down as the arm member 42 rotates about the first fulcrum 421, so that the apparatus main body 3 fixed to the elevating member 43 moves up and down together with the elevating member 43. Thus, in the present embodiment, the elevating member 43 is rotatably connected to the arm member 42 at a second fulcrum 422 provided at an end of the arm member 42 opposite to the first fulcrum 421. The support mechanism 41 has the apparatus main body 3 fixed to the elevating member 43.

[0031] More specifically, the elevating member 43 includes (a pair of) base portions 431, (a pair of) spring pressing portions 432, an upper coupling portion 433, a first frame F1, a second frame F2, (a pair of) third frames F3, and a fourth frame F4. These components of the elevating member 43 are fixed (joined) to each other by, for example, welding, adhesion, fastening tools such as bolts and nuts, or combinations thereof. Therefore, the elevating member 43 moves up and down with these components integrated.

[0032] The pair of base portions 431 are arranged at a constant interval in the left - right direction D3 and are fixed to the wheel track eraser 6 (land leveling body 62) of the apparatus main body 3. The pair of spring retainer portions 432 are arranged above the pair of base portions 431 and are fixed to the pair of base portions 431. The first frame F1 is a square - tube - shaped frame having a length in the left - right direction D3 and connects between the pair of spring retainer portions 432. The second frame F2 is a square - tube - shaped frame having a length in the up - down direction D1 and is fixed to the first frame F1 so as to protrude upward from the central portion of the upper surface of the first frame F1.

[0033] The upper coupling portion 433 is fixed to the upper end portion of the second frame F2. The upper coupling portion 433 has a fourth fulcrum 434 and is rotatably connected to the upper link 25 provided at the rear portion of the vehicle body 2 at the fourth fulcrum 434. The pair of third frames F3 are each cylindrical frames that protrude obliquely downward from the upper coupling portion 433 toward both sides in the left - right direction D3. Here, the third frame F3 includes an inclined portion that is located more rearward toward the lower end side in a side view. The tip end portion (lower end portion) of each third frame F3 is fixed to the wheel track eraser 6 (land leveling body 62) of the apparatus main body 3. The fourth frame F4 is a square - tube - shaped frame having a length in the left - right direction D3 and is formed longer than the total length of the wheel track eraser 6 (land leveling body 62) in the left - right direction D3. The fourth frame F4 is fixed to the upper surface side of the pair of base portions 431 and is also fixed to the pair of third frames F3.

[0034] Here, the support mechanism 41 is connected to the lower link 24 at the first fulcrum 421 of the arm member 42 and to the upper link 25 at the fourth fulcrum 434 of the upper coupling portion 433 in the lifting member 43 by shaft members such as pins having a length in the left - right direction D3. As a result, the arm member 42 and the upper coupling portion 433 are rotatably connected to the lower link 24 and the upper link 25, respectively, about a rotation axis extending in the left - right direction D3.

[0035] The biasing portion 44 biases the apparatus main body 3 upward. In the present embodiment, the connecting device 4 has a pair of biasing portions 44 arranged at a constant interval in the left - right direction D3. Each biasing portion 44 is a telescopic coil spring (coil spring), and is arranged in a posture that can be telescoped in the up - down direction D1. Here, the pair of biasing portions 44 are respectively arranged between a pair of arm members 42 and a pair of spring pressing portions 432. Specifically, each arm member 42 is connected to each spring pressing portion 432 at the second fulcrum 422 by a shaft member such as a pin having a length in the left - right direction D3. As a result, each arm member 42 is rotatably connected to each spring pressing portion 432 about a rotation axis extending in the left - right direction D3. And the biasing portion 44 is arranged between the upper position of the first fulcrum 421 on the upper surface of the arm member 42 and the lower surface of the spring pressing portion 432.

[0036] Thereby, the biasing portion 44 causes a biasing force in the direction of biasing the spring pressing portion 432 upward with respect to the first fulcrum 421 of the arm member 42 to act on the spring pressing portion 432. Therefore, when the coil spring as the biasing portion 44 is compressed, a biasing force in the direction of widening the gap between the two acts between each arm member 42 and each spring pressing portion 432. Since the spring pressing portion 432 is a part of the elevating member 43, the biasing force from the biasing portion 44 acts on the elevating member 43 so as to push the entire elevating member 43 upward. That is, in the present embodiment, the connecting device 4 has a biasing portion 44 that biases the elevating member 43 upward with respect to the first fulcrum 421 of the arm member 42, thereby biasing the apparatus main body 3 upward. Thereby, the operation of raising the elevating member 43 against the self - weight of the apparatus main body 3 etc. can be assisted by the biasing force from the biasing portion 44.

[0037] The guide member 45 is a member that controls the direction of the biasing force by the biasing portion 44 (here, a coil spring). Specifically, the guide member 45 has a length in one direction and is a rod-shaped member inserted inside the coil spring as the biasing portion 44. The biasing portion 44 expands and contracts along the longitudinal direction of the guide member 45. The base end portion (lower end portion) of the guide member 45 is rotatably supported by the arm member 42 at the third fulcrum. In the present embodiment, the third fulcrum is coaxial (common) with the first fulcrum 421, and the guide member 45 is connected to the arm member 42 at the first fulcrum 421 by a shaft member such as a pin having a length in the left-right direction D3 together with the lower link 24. As a result, the guide member 45 is rotatably connected to the arm member 42 about a rotation axis extending in the left-right direction D3.

[0038] The tip end portion (upper end portion) of the guide member 45 passes through the spring retainer portion 432. Therefore, when the arm member 42 rotates relative to the spring retainer portion 432, the guide member 45 rotates about the third fulcrum (the first fulcrum 421), and the inclination angle of the guide member 45 with respect to the arm member 42 changes. That is, in the present embodiment, the connecting device 4 is rotatably connected to the arm member 42 at the third fulcrum and has a guide member 45 that rotates about the third fulcrum as the arm member 42 rotates about the first fulcrum 421. The biasing portion 44 generates a biasing force along the guide member 45. Thereby, buckling of the coil spring as the biasing portion 44 can be prevented, and the biasing force of the biasing portion 44 can be efficiently applied to the elevating member 43.

[0039] [2.2] Configuration of the wheel track eraser device The wheel track eraser device 6 has a plurality of soil gathering bodies 61 and a leveling body 62. The plurality of soil gathering bodies 61 are configured to gather the soil on the surface layer of the farm field G1 to the passing position side of the wheels (mainly the rear wheels 23) of the vehicle body 2 in the left-right direction D3 when the vehicle body 2 of the vehicle body 2 is pulled by the device main body 3 during traveling (forward movement). The leveling body 62 is configured to level the soil gathered by the plurality of soil gathering bodies 61 when the vehicle body 2 of the vehicle body 2 is pulled by the device main body 3 during traveling (forward movement).

[0040] That is, the wheel track erasing device 6 piles up soil with a plurality of soil piling bodies 61 on the passing position side of the wheels, and levels the piled-up soil with a leveling body 62, thereby erasing the wheel tracks formed on the surface layer of the field G1 when the vehicle body 2 travels. Here, the "soil" piled up by the soil piling body 61 or leveled by the leveling body 62 includes mud, sand, clay, etc. In addition, the wheel track erasing device 6 includes not only a configuration that completely erases the wheel tracks, but also a configuration that makes the wheel tracks less conspicuous by covering the wheel tracks (i.e., grooves) with soil.

[0041] In the present embodiment, the leveling body 62 is constituted by a single metal plate, but is not limited to this example, and the leveling body 62 may be constituted by combining a plurality of members. For example, the leveling body 62 may be constituted by combining members divided into a plurality in the front-rear direction D2 or the left-right direction D3.

[0042] The leveling body 62 is a plate-like body made of metal having a length in both the front-rear direction D2 and the left-right direction D3 and having a rectangular shape in plan view. The leveling body 62 is joined to the support mechanism 41 of the connecting device 4 on the upper surface side thereof. Specifically, a pair of base portions 431 and a pair of third frames F3 in the support mechanism 41 are joined to the upper surface of the leveling body 62. The joining of the leveling body 62 and the support mechanism 41 is realized, for example, by welding, adhesion, fastening tools such as bolts and nuts, or a combination thereof.

[0043] The leveling body 62 has a total length (width) longer than the full width of the work vehicle 10 in the left-right direction D3. The leveling body 62 includes an inclined portion 621 that is inclined with respect to the horizontal plane so as to be positioned downward toward the rear end side and extends rearward, and a horizontal portion 622 that extends rearward along the horizontal plane from the rear end portion of the inclined portion 621. By including the inclined portion 621, the front end portion of the leveling body 62 is positioned at a higher position, and while suppressing the movement of soil above the leveling body 62, the soil can be guided rearward along the inclination of the inclined portion 621. The horizontal portion 622 can press the soil guided rearward by the inclined portion 621 from above to level the soil.

[0044] As shown in FIGS. 3, 5, and 6, a plurality (here, 12) of soil retaining members 61 are arranged on the lower surface side (rear surface side) of the leveling body 62, and each is a plate-like body made of metal extending from the front side to the rear side. Here, the plurality of soil retaining members 61 includes a plurality (here, 6) of soil retaining members 61 for the right wheel corresponding to the right rear wheel 23 of the vehicle body 2 and a plurality (here, 6) of soil retaining members 61 for the left wheel corresponding to the left rear wheel 23. Since the plurality of soil retaining members 61 for the right wheel and the plurality of soil retaining members 61 for the left wheel have the same configuration, hereinafter, unless otherwise specified, the description will focus on the plurality of soil retaining members 61 for the left wheel, and the description of the plurality of soil retaining members 61 for the right wheel will be omitted.

[0045] In the present embodiment, the plurality (here, 6) of soil retaining members 61 for the left wheel have three sets of soil retaining members 61 with a pair (2) of left and right soil retaining members 61 as a set of soil retaining members 61. That is, in the present embodiment, the plurality of soil retaining members 61 includes a first pair of soil retaining members 61a, a second pair of soil retaining members 61b, and a third pair of soil retaining members 61c. Here, the central position of the portion through which the (left) rear wheel 23 passes in the left-right direction D3 is defined as a reference position K1 (see FIG. 5). In this case, the pair of left and right soil retaining members 61 in each of the first to third sets are arranged at positions and postures (orientations) symmetric with respect to the left-right direction D3 with the reference position K1 as the center. And these three sets (a total of 6) of soil retaining members 61 are arranged in the order of the first set of soil retaining members 61a, the second set of soil retaining members 61b, and the third set of soil retaining members 61c from the side closer to the reference position K1.

[0046] Also, these three sets (a total of 6) of soil retaining members 61 are arranged so as to be arranged at regular intervals in the left-right direction D3. The pair of left and right soil retaining members 61 in each of the first to third sets are inclined with respect to the traveling direction (front-rear direction D2) of the vehicle body 2 so as to approach each other toward the rear side. That is, the interval in the left-right direction D3 of the pair of left and right soil retaining members 61 in each of the first to third sets becomes narrower toward the rear side. The rear ends of any of the left and right soil retaining members 61 in each of the first to third sets are not in contact with each other, and the interval between the rear ends is ensured to be a predetermined interval (for example, the width of the rear wheel 23) or more.

[0047] As shown in FIG. 6, each of the plurality of soil-accumulating bodies 61 is arranged across the inclined portion 621 and the horizontal portion 622 of the land leveling body 62 in the front-rear direction D2. Each soil-accumulating body 61 includes, at its bottom (lower end portion), a front-side portion 611 that extends rearward while being inclined with respect to the horizontal plane so as to be positioned lower toward the rear side, and a rear-side portion 612 that extends rearward along the horizontal plane. The rear-side portion 612 is formed such that its length in the front-rear direction D2 is longer than that of the front-side portion 611. Here, the rear end portion of the front-side portion 611 is at the same position or substantially the same position as the rear end portion of the inclined portion 621 of the land leveling body 62 in the front-rear direction D2. Therefore, the front-side portion 611 of each soil-accumulating body 61 and the inclined portion 621 of the land leveling body 62 overlap in the vertical direction D1, and the rear-side portion 612 of each soil-accumulating body 61 and the horizontal portion 622 of the land leveling body 62 overlap in the vertical direction D1.

[0048] The front end portions of the three sets (six in total) of soil-accumulating bodies 61 are at the same position in the front-rear direction D2. On the other hand, the three sets (six in total) of soil-accumulating bodies 61 are configured to have different lengths in the front-rear direction D2. The pair of left and right soil-accumulating bodies 61 in each of the first to third sets have a length in the front-rear direction D2 that reaches at least the portion where the rear wheels 23 pass. Therefore, the lengths of the three sets (six in total) of soil-accumulating bodies 61 in the front-rear direction D2 are the shortest for the soil-accumulating body 61a of the first set close to the reference position K1, and increase in the order of the soil-accumulating body 61b of the second set and the soil-accumulating body 61c of the third set.

[0049] The joining of the plurality of soil-accumulating bodies 61 and the land leveling body 62 is realized, for example, by welding, adhesion, fastening tools such as bolts and nuts, or a combination thereof. Further, each of the plurality of soil-accumulating bodies 61 may be configured to be rotatable (rockable) in a plan view with its front end portion as a fulcrum. Thereby, the inclination angle of each soil-accumulating body 61 with respect to the traveling direction (front-rear direction D2) of the vehicle body 2 becomes variable. In this case, it is preferable that the soil-accumulating body 61a of the first set, the soil-accumulating body 61b of the second set, and the soil-accumulating body 61c of the third set rotate in conjunction so that the interval in the left-right direction D3 between the three sets of soil-accumulating bodies 61 is maintained constant.

[0050] [2.3] Configuration of the Support Portion and the Seeding Unit The seeding unit 5 as a plurality (here, five) of working units is supported by a plurality (here, five) of support portions 7 as described above. In the present embodiment, each seeding unit 5 is connected to the elevating member 43 of the connecting device 4 by a support portion 7. More specifically, the plurality of support portions 7 support the plurality of seeding units 5 by connecting the plurality of seeding units 5 (working units) to the fourth frame F4 of the elevating member 43. The plurality of seeding units 5 are arranged at intervals in the left-right direction D3.

[0051] Each support portion 7 has an attachment portion 71 and a support bar 72. The attachment portion 71 is fixed to the fourth frame F4 and has a swing fulcrum 711. The joining of the attachment portion 71 and the fourth frame F4 is realized by, for example, welding, adhesion, fasteners such as bolts and nuts, or a combination thereof. The support bar 72 is a cylindrical member having a length in the front-rear direction D2, and an intermediate portion thereof is connected to the attachment portion 71, and a seeding unit 5 is connected to the rear end portion thereof. That is, the seeding unit 5 is connected to the connecting device 4 (the fourth frame F4) via the support bar 72 and the attachment portion 71 as the support portion 7.

[0052] Here, the support bar 72 is rotatably supported by the attachment portion 71 at the swing fulcrum 711. Specifically, an intermediate portion of the support bar 72 is connected to the attachment portion 71 by a shaft member such as a pin having a length in the left-right direction D3 at the swing fulcrum 711. Thereby, the support bar 72 is rotatably connected to the fourth frame F4 about a rotation axis extending in the left-right direction D3. Then, when the support bar 72 rotates (swings) so as to move the rear end portion up and down about the swing fulcrum 711, the seeding unit 5 connected to the rear end portion of the support bar 72 moves in the up-down direction D1. Further, the front end portion of the support bar 72 contacts the attachment portion 71 from below, thereby restricting the rotation range in the direction in which the rear end portion of the support bar 72 drops, and as a result, setting the bottom dead center in the movement range of the seeding unit 5 in the up-down direction D1.

[0053] In particular, in this embodiment, the support bars 72 of the plurality of support parts 7 connected to the seeding units 5 respectively are individually rotatable (swingable). And with the rotation of each support part 7, each seeding unit 5 will move individually in the vertical direction D1. That is, the apparatus main body 3 has a plurality of working units (seeding units 5) and support parts 7. The plurality of support parts 7 support the plurality of working units (seeding units 5) in a state where they can move individually in the vertical direction D1. In other words, the plurality of working units (seeding units 5) are supported in a state where they can move individually in the vertical direction D1.

[0054] In this way, the seeding units 5 as a plurality (here, five) of working units are arranged behind the wheel mark erasing device 6. That is, the apparatus main body 3 has a seeding unit 5 arranged on the side opposite to the vehicle body 2 (rear side) with respect to the land leveling body 62 in plan view. Since the plurality of seeding units 5 adopt the same configuration, hereinafter, unless otherwise specified, the description will focus on one seeding unit 5, and the description of the other seeding units 5 will be omitted.

[0055] As shown in FIGS. ⑦ and ⑧, the seeding unit 5 includes a float 51, a drive wheel 52, a hopper 53, a feeding part 54, a cover 55, a plurality of hole-opening parts 56, and a rotational force transmission mechanism 57.

[0056] The float 51 supports the seeding unit 5 so that the seeding unit 5 does not sink. The float 51 has a length in the front-rear direction D2 and is disposed at the lower end of the seeding unit 5. The float 51 has a front-side portion 511 and a rear-side portion 512, and is arranged in the order of the front-side portion 511 and the rear-side portion 512 from the front side in the front-rear direction D2 in plan view. The front-side portion 511 is formed in a semicircular shape (see FIG. 5) in plan view, and the rear-side portion 512 is formed in a rectangular shape that is narrower than the front-side portion 511 in the left-right direction D3. The rear-side portion 512 of the float 51 is rotatably connected to the support bar 72 about a rotation axis extending in the left-right direction D3. Thereby, the float 51 is connected to the rear end portion of the support bar 72.

[0057] The front-side portion 511 of the float 51 is formed in a shape in which its front end portion is warped upward in side view. Further, an elastic body (not shown) for biasing the float 51 upward is provided between the first engaging portion 513 of the front-side portion 511 of the float 51 and the second engaging portion 712 of the mounting portion 71. Thereby, the float 51 is biased upward, preventing inconveniences such as the front-side portion 511 of the float 51 being buried in the field G1.

[0058] On the lower surface side (back surface side) of the float 51, a first furrowing device 514 for forming a groove in the field G1 is provided. A pair of the first furrowing devices 514 are provided for one float 51, and these pair of first furrowing devices 514 are arranged on both sides in the left-right direction D3 of the rear-side portion 512. Each first furrowing device 514 is formed by bending a metal plate into a mountain-fold shape convex downward, and is formed such that the amount of protrusion from the lower surface of the float 51 increases toward the center side in the left-right direction D3 and the rear side in the front-rear direction D2. Each first furrowing device 514 forms a seeding groove G11 (see FIG. 9) along the traveling direction (front-rear direction D2) of the vehicle body 2 when the vehicle body 2 is traveling. In the present embodiment, since a pair of first furrowing devices 514 are provided for one seeding unit 5, two seeding grooves G11 are formed at intervals in the left-right direction D3.

[0059] Further, on the lower surface side (back surface side) of the float 51, a second furrow opener 515 for forming a furrow in the field G1 is provided. The second furrow opener 515 is disposed at the center in the left-right direction D3 of the float 51. The second furrow opener 515 is formed by bending a metal plate into a mountain-fold shape convex downward, and is formed such that the amount of protrusion from the lower surface of the float 51 increases toward the center side in the left-right direction D3 and the rear side in the front-rear direction D2. The second furrow opener 515 forms a drainage groove G12 (see FIG. 9) along the traveling direction (front-rear direction D2) of the vehicle body 2 when the vehicle body 2 is traveling.

[0060] Here, as shown in FIGS. 7 and 8, the second furrow opener 515 is disposed behind the pair of first furrow openers 514 in the front-rear direction D2 and between the pair of first furrow openers 514 in the left-right direction D3. That is, the seeding unit 5 includes a first furrow opener 514 that forms a seeding groove G11 along the traveling direction of the vehicle body 2, and a second furrow opener 515 that forms a drainage groove G12 along the traveling direction of the vehicle body 2 on the side of the seeding groove G11. Here, the height H2 (see FIG. 7) of the second furrow opener 515 from the lower surface of the float 51 is greater (higher) than the height H1 (see FIG. 7) of the first furrow opener 514 from the lower surface of the float 51. That is, the second furrow opener 515 is set to have a larger amount of protrusion from the lower surface of the float 51 than the first furrow opener 514. Therefore, the drainage groove G12 is formed deeper than the seeding groove G11.

[0061] The hopper 53 is an example of a container for storing a spraying material. In the present embodiment, since the working device 1 performs a spraying operation (i.e., a seeding operation) using seeds as the spraying material, the hopper 53 is an example of a container for storing (reserving) seeds. And in the present embodiment, one surface of the hopper 53, which is a container, constitutes the target surface 50 of the seeding unit 5 (working unit). That is, the target surface 50 is one surface of a container (here, the hopper 53) for storing a spraying material (here, seeds). Specifically, the upper surface of the hopper 53 in a state where the seeding unit 5 is in the first posture is defined as the target surface 50. Hereinafter, unless otherwise specified, the description will be made assuming that the seeding unit 5 is in the first posture.

[0062] The hopper 53 has a rectangular shape in plan view and is disposed at the upper end of the seeding unit 5. The hopper 53 has a hopper body 531 and a lid 532. The hopper body 531 is a box body that is open on one side with its upper surface as the opening surface. The lid 532 is configured to be openable and closable with respect to the hopper body 531. In the closed state, it covers the opening surface (upper surface) of the hopper body 531, and in the open state, it opens the opening surface (upper surface) of the hopper body 531. Therefore, when the lid 532 is in the open state, seeds as the scattering material can be replenished into the hopper body 531 from the upper surface of the hopper body 531.

[0063] The feeding section 54 sequentially feeds out the seeds stored in the hopper 53 and directly sows them in the field G1. The feeding section 54 is disposed below the hopper 53 and is integrated with the hopper 53. In the present embodiment, as shown in FIG. 8, the feeding section 54 includes a left feeding section 541 and a right feeding section 542, and is configured in a bifurcated shape branched in the left-right direction D3. The left feeding section 541 and the right feeding section 542 are fixed to the cover 55 so as to penetrate the upper surface of the cover 55.

[0064] The internal space of the hopper 53 and the internal spaces of the feeding section 54 (the left feeding section 541 and the right feeding section 542) are in communication (continuous), and the seeds stored in the hopper 53 can be supplied to the feeding section 54 by their own weight or the like. Here, the feeding section 54 further has a feeding roll 543 and a discharging section 544. The feeding roll 543 and the discharging section 544 are disposed in the cover 55. In the present embodiment, corresponding to the left feeding section 541 and the right feeding section 542, the feeding roll 543 and the discharging section 544 are provided in pairs for one seeding unit 5. That is, a pair of feeding rolls 543 are arranged at intervals in the left-right direction D3 and are respectively located below the left feeding section 541 and the right feeding section 542. A pair of discharging sections 544 are arranged at intervals in the left-right direction D3 and are respectively located below the left feeding section 541 and the right feeding section 542.

[0065] Each delivery roll 543 discharges seeds supplied from the hopper 53 through the left delivery section 541 or the right delivery section 542 from the discharge section 544 at a predetermined timing. Each delivery roll 543 is formed in a columnar shape having an axis along the left-right direction D3, and has a plurality of recesses at regular intervals in the circumferential direction on its circumferential surface. Thus, each delivery roll 543 takes in seeds into the recesses located on the upper side and discharges the seeds from the recesses located on the lower side to the discharge section 544. Further, a driven shaft 545 extending in the left-right direction D3 is rotatably held by the cover 55, and the pair of delivery rolls 543 are held by the cover 55 in a rotatable state together with the driven shaft 545. Therefore, as each delivery roll 543 rotates about the driven shaft 545, an appropriate amount of seeds in the hopper 53 are discharged from the discharge section 544. The discharge section 544 is open downward, and the seeds discharged from the discharge section 544 are directly sown in the field G1.

[0066] The working device 1 does not include a rotational drive unit (power source) for rotationally driving the drive wheels 52, and the drive wheels 52 rotate so as to roll on the field G1 as the vehicle body 2 travels. That is, in the present embodiment, the working unit (seeding unit 5) includes the drive wheels 52 that roll as the vehicle body 2 travels. In the present embodiment, the drive wheels 52 have a circular outer frame portion 521 and an annular inner frame portion 522. The outer frame portion 521 and the inner frame portion 522 are arranged at intervals in the left-right direction D3 and are connected to each other. The drive wheels 52 further have a drive shaft 523 extending in the left-right direction D3, and are configured to be rotatable about the drive shaft 523. The drive shaft 523 is rotatably held by the cover 55 in the same manner as the driven shaft 545.

[0067] In the present embodiment, a pair of drive wheels 52 are also provided for one seeding unit 5 so as to correspond to the left feeding section 541 and the right feeding section 542. The pair of drive wheels 52 are arranged at intervals in the left - right direction D3, and are respectively arranged at positions corresponding to the lower ends of the left feeding section 541 and the right feeding section 542. The pair of discharge sections 544 are respectively arranged so as to be housed within the width of the drive wheels 52 in the left - right direction D3. The drive wheel 52 corresponding to the left feeding section 541 is defined as the first drive wheel 52A (see FIG. 8), and the drive wheel 52 corresponding to the right feeding section 542 is defined as the second drive wheel 52B (see FIG. 8).

[0068] Here, on the outer periphery of each drive wheel 52, a plurality of opening portions 56 are provided at predetermined intervals in the circumferential direction. The plurality of opening portions 56 are members that extend radially from the drive shaft 523 in a side view. Each opening portion 56 protrudes outward (opposite to the drive shaft 523) from the outer periphery of the drive wheel 52, and the opening portion 56 is configured to scoop up the soil in the field G1 toward the rear side as the drive wheel 52 rotates to form seeding holes G13 (see FIG. 9) in the field G1. Here, as shown in FIG. 8, the opening portion 56 is arranged at the same position as the first furrow opener 514 in the left - right direction D3, and forms seeding holes G13 in the seeding furrow G11. That is, the seeding unit 5 includes drive wheels 52 that roll as the vehicle body 2 travels, and a plurality of opening portions 56 provided on the outer periphery of the drive wheels 52 that scoop the soil in the seeding furrow G11 to form seeding holes G13 in the seeding furrow G11.

[0069] Here, in the present embodiment, the first drive wheel 52A and the second drive wheel 52B are integrally connected by the same (single) drive shaft 523. Therefore, the first drive wheel 52A and the second drive wheel 52B rotate synchronously with each other while maintaining the rotational angle difference around the drive shaft 523. And a plurality of opening portions 56 are provided on each of the first drive wheel 52A and the second drive wheel 52B, and these plurality of opening portions 56 have a phase difference in the circumferential direction between the first drive wheel 52A and the second drive wheel 52B.

[0070] Specifically, in the present embodiment, four apertures 56 are provided in each of the first drive wheel 52A and the second drive wheel 52B. The four apertures 56 in each drive wheel 52 are arranged at intervals of 90 degrees around the drive wheel 52. On the other hand, the apertures 56 provided in the first drive wheel 52A and the apertures 56 provided in the second drive wheel 52B are arranged at intervals of 45 degrees around the drive wheel 52. Thus, in the first drive wheel 52A and the second drive wheel 52B, the positions (phases) where the apertures 56 are arranged in the rotational direction are set to be different.

[0071] Further, an opening 561 for dropping a part of the scooped soil is formed in the aperture 56. In the present embodiment, as an example, the opening 561 is formed in a notch shape that opens toward the tip side (opposite side to the drive shaft 523) of the aperture 56. By providing such an opening 561, it is possible to appropriately adjust the amount of soil scooped by the aperture 56.

[0072] Moreover, the working device 1 does not include a rotational drive unit (power source) for rotationally driving the pay-out roll 543, and is configured to rotate the pay-out roll 543 by transmitting the rotational force of the drive wheel 52 to the pay-out roll 543. Therefore, as shown in FIG. 8, the seeding unit 5 has a rotational force transmission mechanism 57 that transmits the rotational force of the drive wheel 52 to the pay-out roll 543. Specifically, the rotational force transmission mechanism 57 has a gear that rotates integrally with the drive shaft 523 and a gear that rotates integrally with the driven shaft 545. Thus, when the drive wheel 52 rotates, the rotational force transmission mechanism 57 transmits the rotational force of the drive shaft 523 to the driven shaft 545, rotating the pair of pay-out rolls 543.

[0073] Here, the timing at which each pay-out roll 543 discharges seeds from the discharge portion 544 is determined according to its rotational speed (number of rotations). In the present embodiment, since the pair of pay-out rolls 543 are connected by the same (single) driven shaft 545, they rotate integrally.

[0074] The cover 55 is formed in a hollow rectangular parallelepiped shape having a length in the left - right direction D3 in plan view and an open bottom surface. Here, as described above, the cover 55 holds the feeding part 54 (the left feeding part 541, the right feeding part 542, and the discharging part 544), and the hopper 53. Further, the cover 55 rotatably holds the drive shaft 523 of the drive wheel 52 and the driven shaft 545 of the feeding part 54. In short, in this embodiment, all the components of the seeding unit 5 except the float 51 are held by the cover 55.

[0075] Here, the cover 55 is rotatably supported by the support bar 72 of the support part 7 at the opening - closing fulcrum 551 (see FIG. 7). Specifically, the cover 55 has the opening - closing fulcrum 551 at its rear end and the locking part 552 (see FIG. 7) at its front end. On the lower surface side of the support bar 72, as shown in FIG. 7, a rear side stay 721 is arranged at the rear end position of the support bar 72, and a front side stay 722 is arranged at a position in front of the rear side stay 721 of the support bar 72. The rear side stay 721 and the front side stay 722 are each formed in a rectangular shape open downward in rear view and are fixed to the support bar 72 (see FIG. 8). And the cover 55 is connected to the rear side stay 721 by a shaft member such as a pin having a length in the left - right direction D3 at the opening - closing fulcrum 551, and is connected to the front side stay 722 by a shaft member such as a pin having a length in the left - right direction D3 at the locking part 552. Therefore, in a state where the opening - closing fulcrum 551 and the locking part 552 are connected to the rear side stay 721 and the front side stay 722 respectively, the cover 55 is fixed to the support bar 72 in such a manner as to sandwich the support bar 72 between the rear side stay 721 and the front side stay 722. On the other hand, in a state where the connection between the locking part 552 and the front side stay 722 is released, the cover 55 is rotatably connected to the support bar 72 about a rotation axis extending in the left - right direction D3 passing through the opening - closing fulcrum 551. FIG. 8 shows an imaginary line (two - dot chain line) of the shaft member 553 that connects the cover 55 to the support bar 72 (rear side stay 721) at the opening - closing fulcrum 551.

[0076] Thus, in the "unlocked state" where the locking portion 552 is free, the cover 55 is supported by the support portion 7 (support bar 72) so as to be rotatable about the opening / closing fulcrum 551 provided at the rear end thereof. Then, when the cover 55 rotates, the components of the seeding unit 5 held by the cover 55 (excluding the float 51) also rotate about the opening / closing fulcrum 551. In short, the support portion 7 rotatably supports the seeding unit 5 between a first posture in which the target surface 50 of the seeding unit 5 (here, the upper surface of the hopper 53) is directed upward from the horizontal and a second posture in which the target surface 50 is directed downward from the horizontal (see FIGS. 12 and 13). On the other hand, in the "locked state" where the locking portion 552 is fixed to the support bar 72 (front side stay 722), the rotation of the cover 55 is restricted, and the seeding unit 5 is maintained in the first posture in which the target surface 50 is directed upward from the horizontal. When performing seeding work with the seeding unit 5, by setting it to the "locked state", the seeding unit 5 maintains the first posture.

[0077] [3] Operation of the working device Next, the operation of the working device 1 according to the present embodiment will be described with reference to FIGS. 9 to 13. First, the operation of the working device 1 when performing work (here, seeding work) will be described below, and then the "hopper open operation" for setting the seeding unit 5 to the second posture will be described.

[0078] [3.1] Operation during work On the rear side of the vehicle body 2 of the work vehicle 10, the apparatus main body 3 is connected by a connecting device 4. When the vehicle body 2 is traveling, the apparatus main body 3 of the working apparatus 1 is towed by the vehicle body 2. At this time, the apparatus main body 3 is towed in a posture that grounds at least the float 51 and the drive wheel 52 of each seeding unit 5, and the wheel mark eraser 6 on the farm field G1 (see FIG. 1). On the lower surface side of the float 51, a pair of first furrow openers 514 and second furrow openers 515 are arranged. Therefore, when the vehicle body 2 moves forward, as shown in FIG. 9, on the farm field G1, a pair of seeding grooves G11 are formed along the traveling direction of the vehicle body 2 (the vertical direction in FIG. 9) by the pair of first furrow openers 514, and a drainage groove G12 is formed along the traveling direction of the vehicle body 2 (the vertical direction in FIG. 9) by the second furrow opener 515. Further, since a plurality of apertures 56 are provided on the outer periphery of the drive wheel 52, when the vehicle body 2 moves forward, a plurality of seeding holes G13 are formed on the farm field G1 along the traveling direction of the vehicle body 2 by the plurality of apertures 56.

[0079] Here, in the present embodiment, in the left - right direction D3, the first furrow opener 514, the aperture 56 of the drive wheel 52, and the discharge part 544 of the feeding part 54 are arranged at the same or substantially the same position. Thereby, when the vehicle body 2 travels forward, in the left - right direction D3, the seeding groove G11 formed by the first furrow opener 514 and the seeding hole G13 formed by the aperture 56 are formed at the same or substantially the same position. And for the seeds discharged from the discharge part 544, in the left - right direction D3, they are discharged (direct - seeded) at the same or substantially the same position as the seeding groove G11 and the aperture 56.

[0080] More specifically, in the forward direction of the position acting on the field G1, the first furrow opener 514, the opening 56 of the drive wheel 52, and the discharge part 544 of the feeding part 54 are arranged in this order. Therefore, a seeding groove G11 is formed in the field G1 by the first furrow opener 514, a seeding hole G13 is formed in the seeding groove G11 by the opening 56, and seeds are directly sown from the discharge part 544 by the feeding roll 543. Further, the opening 56 forms a seeding hole G13 in the field G1 by scooping up the soil of the field G1 toward the rear side, and deposits the soil scooped up behind the seeding hole G13 to form a soil part G14. As a result, in the seeding groove G11, the seeding holes G13 and the soil parts G14 are alternately formed along the longitudinal direction of the seeding groove G11.

[0081] And in the seeding groove G11, seeds are discharged from the discharge part 544 by the feeding roll 543 at a predetermined timing, so that seeds can be directly sown in the seeding holes G13 or the soil parts G14 in the seeding groove G11. Here, regarding the position for directly sowing seeds in the longitudinal direction of the seeding groove G11, it can be appropriately adjusted by adjusting the rotation timing of the feeding roll 543 and the like. In this way, by directly sowing seeds in the seeding groove G11 in which the soil parts G14 are intermittently formed, even if the seeds are likely to be washed away by the water on the surface of the field G1 (paddy field), the seeds ride on the soil parts G14, and it becomes easier to keep the seeds at a predetermined direct sowing position in the seeding groove G11.

[0082] Here, in the present embodiment, the working unit (seeding unit 5) includes a pair of feeding rolls 543 that rotate as the drive wheel 52 rolls, and a pair of discharge parts 544 that discharge discharge materials (seeds) at a timing synchronized with the rotation of the pair of feeding rolls 543. The pair of feeding rolls 543 rotate synchronously with each other. As a result, seeds as discharge materials are discharged from the pair of discharge parts 544 at synchronized timings. Thereby, seeds are discharged from the pair of discharge parts 544 in a well-balanced manner, and it becomes easier to appropriately adjust the amount and interval of the directly sown seeds.

[0083] Further, the second furrowing device 515 is disposed between the pair of first furrowing devices 514 in the left - right direction D3. In particular, in the present embodiment, both end portions of the second furrowing device 515 in the left - right direction D3 are arranged so as to overlap with the pair of first furrowing devices 514 in the front - rear direction D2. Therefore, as shown in FIG. 9, a drainage groove G12 is formed without a gap between the pair of sowing grooves G11. As a result, the drainage groove G12 can drain the water in the pair of sowing grooves G11 along the longitudinal direction of the drainage groove G12. Consequently, it becomes easier to prevent the seeds from being washed away by the water on the surface of the field G1 (paddy field).

[0084] Further, in the present embodiment, the working unit (seeding unit 5) includes a first drive wheel 52A and a second drive wheel 52B connected by the same drive shaft 523 as the drive wheels 52. A plurality of apertures 56 are provided at mutually different positions in the circumferential direction on the outer circumferences of each of the first drive wheel 52A and the second drive wheel 52B. Therefore, while suppressing the number of apertures 56 provided in each drive wheel 52, the apertures 56 are arranged in small increments in the circumferential direction in both the first drive wheel 52A and the second drive wheel 52B. Therefore, it is possible to surely drive the drive wheels 52 while reducing the probability that the seeds discharged from the discharge portion 544 adhere to the apertures 56.

[0085] In addition, since an opening 561 for dropping a part of the scooped soil is formed in the aperture 56, it is possible to appropriately adjust the amount of soil scooped by the aperture 56. That is, when the amount of soil scooped by the aperture 56 is too large, the soil hand portion G14 formed behind the sowing hole G13 may become too high due to the soil scooped by the aperture 56. However, by the opening 561, the amount of soil scooped by the aperture 56 can be reduced, and the height of the soil hand portion G14 can be appropriately adjusted. Furthermore, due to the presence of the opening 561, it is possible to reduce the probability that the seeds discharged from the discharge portion 544 adhere to the aperture 56.

[0086] Next, the operation of the wheel track eraser 6 disposed in front of the seeding unit 5 will be described. When the vehicle body 2 travels forward, the wheel track eraser 6 towed by the vehicle body 2 moves the soil toward the reference position K1, which is the center of the portion where the rear wheels 23 pass, with each of the plurality of soil pushing bodies 61. At this time, among the first set of soil pushing bodies 61a closest to the reference position K1 in the left-right direction D3, although the degree of soil crushing is rough, the crushed soil can be moved toward the reference position K1 side. Among the second set of soil pushing bodies 61b that are second closest to the reference position K1 in the left-right direction D3, the soil can be moved toward the reference position K1 side while making the degree of soil crushing finer. Further, among the third set of soil pushing bodies 61c that are farthest from the reference position K1 in the left-right direction D3, the soil can be moved toward the reference position K1 side while making the degree of soil crushing even finer. In this way, the soil can be moved toward the reference position K1 side while gradually making the degree of soil crushing by the plurality of sets of soil pushing bodies 61a to 61c finer.

[0087] Also, in the present embodiment, among the plurality of sets of soil pushing bodies 61a to 61c, the closer the soil pushing body 61 is to the reference position K1, which is the center of the portion where the rear wheels 23 pass, the shorter the length in the front-rear direction D2. Thereby, with each of the plurality of soil pushing bodies 61, the crushed soil can be appropriately moved while being collected toward the reference position K1 side. Therefore, for example, even when the soil in the farm field G1 is hard, the soil can be moved toward the reference position K1 side in a state where the soil has been sufficiently crushed by the plurality of soil pushing bodies 61. Moreover, since the soil is moved by the plurality of soil pushing bodies 61, a sufficient amount of soil can be ensured as the amount of soil to be moved.

[0088] Furthermore, since the wheel track eraser device 6 includes not only a plurality of soil heaping bodies 61 but also a leveling body 62, the soil heaped toward the reference position K1 side by the plurality of soil heaping bodies 61 can be leveled by the leveling body 62, and the wheel tracks can be appropriately erased (or made inconspicuous). Moreover, since the leveling body 62 has an inclined portion 621 on its front side, it is possible to suppress the movement of soil upward of the leveling body 62 and move a sufficient amount of soil to the lower side of the leveling body 62. Thereby, the leveling body 62 can appropriately level the soil moved to the lower side of the leveling body 62 at the inclined portion 621 at the horizontal portion 622, and the wheel tracks can be appropriately erased (or made inconspicuous).

[0089] As described above, in the working device 1 according to the present embodiment, the device main body 3 has, as a wheel track eraser device 6, a plurality of soil heaping bodies 61 and a leveling body 62. The plurality of soil heaping bodies 61 heap soil at the passing positions of the wheels (mainly the rear wheels 23) of the vehicle main body 2. The leveling body 62 levels the soil heaped by the plurality of soil heaping bodies 61. Thereby, in the working device 1, before the seeding operation is performed by the seeding unit 5, the wheel tracks (unevenness) generated in the field G1 by the passage of the wheels (particularly the rear wheels 23) of the vehicle main body 2 are erased (or made inconspicuous), so that the field G1 in a state suitable for the seeding operation can be prepared.

[0090] By the way, in the working device 1 according to the present embodiment, as described above, the connecting device 4 that connects the device main body 3 to the vehicle main body 2 has a support mechanism 41. The support mechanism 41 supports the device main body 3 in a state where the device main body 3 can move in the vertical direction D1 in response to an external force while restricting the movement of the device main body 3 other than in the vertical direction D1. That is, as shown in FIGS. 10 and 11, the entire device main body 3 including the wheel track eraser device 6 (a plurality of soil heaping bodies 61 and a leveling body 62) can be moved in the vertical direction D1 in response to an external force.

[0091] For example, when the apparatus main body 3 passes through a depression or a puddle formed in a part of the farm field G1, due to the gravity acting on the apparatus main body 3 (the self-weight of the apparatus main body 3), as shown in FIG. 10, within the range from the top dead center to the bottom dead center in the movable range of the apparatus main body 3, the apparatus main body 3 moves downward in the vertical direction D1. That is, the arm member 42 rotates around the first fulcrum 421 (clockwise in FIG. 10), whereby the entire apparatus main body 3 is displaced (lowered) so as to sink relatively downward with respect to the first fulcrum 421. In the "bottom dead center" at the lower part of FIG. 10, the working device 1 before the apparatus main body 3 descends is shown by an imaginary line (two-dot chain line).

[0092] When the apparatus main body 3 descends, the coil spring as the biasing portion 44 is compressed. Thereby, the impact when the apparatus main body 3 descends is absorbed by the biasing portion 44, and it is possible to mitigate the impact applied to the apparatus main body 3 and the connecting device 4, and prevent excessive sinking of the apparatus main body 3. Further, when the coil spring as the biasing portion 44 is compressed, the guide member 45 rotates relatively (clockwise in FIG. 10) around the third fulcrum (the first fulcrum 421). Thereby, buckling of the coil spring as the biasing portion 44 is prevented, and the biasing force of the biasing portion 44 can be efficiently applied to the lifting member 43.

[0093] Conversely, for example, when the apparatus main body 3 escapes from a depression or a puddle formed in a part of the farm field G1, due to the reaction force (vertical resistance force, buoyancy force, etc.) acting on the apparatus main body 3 from the farm field G1, as shown in FIG. 11, within the range from the bottom dead center to the top dead center in the movable range of the apparatus main body 3, the apparatus main body 3 moves upward in the vertical direction D1. That is, the arm member 42 rotates around the first fulcrum 421 (counterclockwise in FIG. 11), whereby the entire apparatus main body 3 is displaced (lifted) so as to lift relatively upward with respect to the first fulcrum 421. In the "top dead center" at the lower part of FIG. 11, the working device 1 before the apparatus main body 3 ascends is shown by an imaginary line (two-dot chain line).

[0094] When the apparatus main body 3 rises, the coil spring as the biasing portion 44 extends. As a result, the force for raising the apparatus main body 3 can be assisted by the biasing portion 44, the apparatus main body 3 can be smoothly lifted, and excessive sinking of the apparatus main body 3 can be prevented. Here, it is preferable that the biasing force from the biasing portion 44 is adjusted so that the apparatus main body 3 is in an appropriate grounding state with respect to the field G1. Further, when the coil spring as the biasing portion 44 extends, the guide member 45 rotates relatively (counterclockwise in FIG. 11) about the third fulcrum (the first fulcrum 421). Thereby, buckling of the coil spring as the biasing portion 44 can be prevented, and the biasing force of the biasing portion 44 can be efficiently applied to the elevating member 43.

[0095] As a result, for example, even when there are irregularities in the field G1, during the operation, the apparatus main body 3 appropriately moves in the vertical direction D1 so as to follow the field G1, whereby the grounding state of the apparatus main body 3 with respect to the field G1 can be appropriately maintained. Therefore, in the working device 1 according to the present embodiment, during the execution of the work, sinking or floating of the apparatus main body 3 with respect to the field G1 hardly occurs, and it is easy to suppress a decrease in the reliability and efficiency of the work (for example, wheel track erasing work) by the apparatus main body 3. In the present embodiment, since the apparatus main body 3 includes the wheel track erasing device 6 and the plurality of seeding units 5, it is easy to suppress a decrease in the reliability and efficiency not only in the wheel track erasing work but also in the seeding work.

[0096] Furthermore, in the present embodiment, as described above, the support bars 72 of the plurality of support portions 7 respectively connected to the seeding units 5 are individually rotatable (swingable). Therefore, as each support portion 7 rotates, each seeding unit 5 individually moves in the vertical direction D1. Thereby, even when there are irregularities on the surface of the field G1, the positions of the seeding units 5 in the vertical direction D1 are individually adjusted, and excessive sinking or floating of each seeding unit 5 can be suppressed. As a result, it becomes easier to perform the seeding work evenly with the plurality of seeding units 5. Moreover, since the plurality of working units (seeding units 5) in the apparatus main body 3 individually move in the vertical direction D1, the lifting and lowering operation of the entire apparatus main body 3 as described above becomes smoother.

[0097] Furthermore, in the present embodiment, as the apparatus main body 3 rises, the relative position of the fourth fulcrum 434 with respect to the first fulcrum 421 in plan view is displaced toward the vehicle main body 2 side. That is, the connecting device 4 has a first fulcrum 421 connected to the lower link 24 and a fourth fulcrum 434 connected to the upper link 25. Here, the relative position between the first fulcrum 421 and the fourth fulcrum 434 in the front-rear direction D2 changes as the apparatus main body 3 moves in the vertical direction D1. Specifically, as shown in FIG. 11, when the apparatus main body 3 is displaced (raised) so as to be lifted upward, the fourth fulcrum 434 moves obliquely upward in the front, and thus moves relatively toward the vehicle main body 2 side (that is, forward) with respect to the first fulcrum 421. As a result, even if the total length of the lower link 24 increases by the length of the arm member 42, it is less likely that the length of the upper link 25 will be insufficient.

[0098] [3.2] Hopper opening operation As described above, the seeding unit 5 (working unit) is rotatably supported by the support portion 7 between a first posture in which the target surface 50 is directed upward from the horizontal and a second posture in which the target surface 50 is directed downward from the horizontal. That is, after releasing the lock (connection with the front side stay 722) of the lock portion 552 of the cover 55 to make it in the "unlocked state", by rotating the cover 55 with the opening / closing fulcrum 551 as a fulcrum, as shown in FIGS. 12 and 13, the posture of the seeding unit 5 is switched from the first posture to the second posture. The first posture is a working posture adopted during work (here, seeding work), and the second posture is a non-working posture adopted during non-work (including during maintenance of the working device 1, etc.).

[0099] Thus, in the working device 1 according to the present embodiment, the posture of the working unit (seeding unit 5) can be switched between the first posture and the second posture. Therefore, for example, during non-work, by appropriately switching the posture of the working unit from the working posture, it is possible to improve the maintainability of the apparatus main body 3.

[0100] In FIGS. 12 and 13, only one of the plurality of seeding units 5 (here, the leftmost one) is shown in the second posture, and in FIG. 13, the seeding unit 5 in the first posture is shown by an imaginary line (two-dot chain line). That is, in the present embodiment, a support portion 7 is provided for each seeding unit 5, and the plurality of seeding units 5 can individually switch postures. Thus, the apparatus main body 3 has a plurality of work units (seeding units 5). These plurality of work units (seeding units 5) are supported by the support portion 7 in a rotatable state between the first posture and the second posture individually. Therefore, when performing maintenance on only an arbitrary work unit among the plurality of work units, by switching the posture of only the work unit, it is not necessary to switch the postures of unnecessary work units, leading to an improvement in the maintainability of the apparatus main body 3.

[0101] Further, in the present embodiment, the work unit includes a spraying unit (seeding unit 5) that performs a spraying operation (seeding operation) of a spraying material (here, seeds), and the target surface 50 is one surface of a container that stores the spraying material (here, the upper surface of the hopper 53). Therefore, for example, when discharging the seeds remaining in the hopper 53 from the opening surface (upper surface) of the hopper main body 531 after the seeding operation, by setting the seeding unit 5 to the second posture, the seeds can be discharged collectively from the opening surface of the hopper main body 531. That is, as shown in FIGS. 12 and 13, by setting the upper surface of the hopper 53 (target surface 50) downward to the second posture, the seeds in the hopper 53 can be discharged collectively, improving the maintainability of the work unit.

[0102] Further, in the present embodiment, as shown in FIG. 12, when the working unit (seeding unit 5) is in the second posture, the pair of feeding rolls 543 are exposed upward. Thereby, by setting the seeding unit 5 in the second posture, it becomes possible to easily perform maintenance such as removing seeds attached to the pair of feeding rolls 543. Further, each of the pair of feeding rolls 543 is configured such that the size (dimension in the left-right direction D3) of a plurality of concave portions formed on its peripheral surface can be manually adjusted. Specifically, by manually rotating the rotation operation portion provided on each feeding roll 543 about the driven shaft 545, it is possible to change the size of the plurality of concave portions by a "screw mechanism". Since the amount of seeds fed out per rotation of each feeding roll 543 changes depending on the size of the concave portion, it is possible to adjust the amount of seeds discharged per rotation of each feeding roll 543 by adjusting the size of the concave portion.

[0103] [4] Modification Hereinafter, modifications of Embodiment 1 will be listed. The modifications described below can be applied in appropriate combinations.

[0104] The shapes and dimensions of each part of the apparatus main body 3 and the connecting device 4 are not limited to the aspects described in Embodiment 1. Further, in Embodiment 1, the working device 1 is exemplified as being "for 10 rows" having five seeding units 5 each having a pair of drive wheels 52 and discharge portions 544, but the configuration is not limited to this. For example, it may be "for 2 rows" having one seeding unit 5 each having a pair of drive wheels 52 and discharge portions 544, "for 4 rows" having two, "for 6 rows" having three, "for 8 rows" having four, "for 12 rows" having six, and so on. Further, each seeding unit 5 may have one or three or more drive wheels 52 and discharge portions 544.

[0105] Further, the working unit is not limited to the seeding unit 5 and may include a spraying unit that sprays a spraying material such as fertilizer or chemical liquid. Alternatively, the working unit may include a working unit other than the spraying unit.

[0106] In Embodiment 1, an example was shown in which not only the wheel mark eraser 6 but also the seeding unit 5 was connected to the rear side of the vehicle body 2. However, it is also possible to connect and use only the wheel mark eraser 6. Further, the wheel mark eraser 6 may not have the soil leveling body 62 and may have only a plurality of soil gathering bodies 61.

[0107] In Embodiment 1, a plurality of seeding units 5 are configured to be individually movable in the vertical direction D1, but this configuration is not an essential configuration of the working device 1. That is, the plurality of seeding units 5 may be directly fixed to, for example, the connecting device 4 or the wheel mark eraser 6.

[0108] In Embodiment 1, the support bar 72 is handled as a set with the attachment portion 71 that constitutes the support portion 7. However, the present invention is not limited to this, and the support bar 72 and the attachment portion 71 may be handled separately. For example, the support bar 72 (including the rear side stay 721 and the front side stay 722) may be provided as a component associated with the seeding unit 5 (working unit), and the support portion 7 may be constituted by being combined with the attachment portion 71.

Explanation of Reference Numerals

[0109] 1 Towed working device 2 Vehicle body 3 Device body 5 Seeding unit (working unit, spraying unit) 7 Support portion 10 Working vehicle 50 Target surface 52 Driving wheel 52A First driving wheel 52B Second driving wheel 53 Hopper (container) 543 Pay - out roll 544 Discharge portion 56 Hole - opening portion D1 Vertical direction

Claims

1. It is provided with a device body that is connected to the vehicle body of a work vehicle and towed by the vehicle body, The device body has a work unit including a container and a support unit that supports the work unit, The support unit rotatably supports the work unit between a first posture and a second posture, and a target surface that is the opening surface of the container in the work unit and faces above horizontal in the first posture faces below horizontal in the second posture, The device body has a plurality of work units, The plurality of work units are individually supported by the support unit in a state where they can move vertically, A towed work device.

2. It is provided with a device body that is connected to the vehicle body of a work vehicle and towed by the vehicle body, The device body has a work unit including a container and a support unit that supports the work unit, The support unit rotatably supports the work unit between a first posture and a second posture, and a target surface that is the opening surface of the container in the work unit and faces above horizontal in the first posture faces below horizontal in the second posture, The work unit includes drive wheels that roll as the vehicle body travels, A towed work device.

3. The work unit includes a pair of payout rolls that rotate as the drive wheels roll, and a pair of discharge units that discharge discharge materials at a timing synchronized with the rotation of the pair of payout rolls, The pair of payout rolls rotate in synchronization with each other, The towed work device according to Claim 2.

4. When the work unit is in the second posture, the pair of payout rolls are exposed upward, The towed work device according to Claim 3.

5. The work unit includes a first drive wheel and a second drive wheel that are connected by the same drive shaft as the drive wheels, A plurality of apertures are provided at mutually different positions in the circumferential direction on the outer periphery of each of the first drive wheel and the second drive wheel, The towed work device according to any one of Claims 2 to 4.

6. The work unit includes a spraying unit that performs a spraying operation of a spraying material, The target surface is one surface of a container that houses the spraying material, The towed work device according to any one of Claims 1 to 5.

7. The device body has a plurality of work units, The plurality of work units are individually supported by the support unit in a state where they can rotate between the first posture and the second posture, The traction working device according to any one of claims 1 to 6.

8. The traction working device according to any one of claims 1 to 7, and the vehicle body, and comprising a work vehicle.

Images