Rice transplanter

Abstract

To simplify a power switching structure that tends to be complicated in an intrarow spacing speed change gear capable of changing a work speed of a seedling planting device with respect to a travelling speed of a travelling part.SOLUTION: A rice transplanter includes a seedling planting device and an intrarow spacing speed change gear. The intrarow spacing speed change gear includes an output shaft for transmitting power to the seedling planting device, a first switching mechanism capable of switching power of a power transmission route to the output shaft to a plurality of steps, and a second switching mechanism capable of switching power of the power transmission route to the output shaft to a plurality of steps. The intrarow spacing speed change gear is configured so as to switch the power of the power transmission route to the output shaft to a plurality of speed change steps by combining the power switched by the first switching mechanism and the power switched by the second switching mechanism. The plurality of speed change steps include a plurality of uniform speed power speed change steps and a plurality of non-uniform speed power speed change steps, and only part of the speed change steps can be used of the plurality of non-uniform speed power speed change steps.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a rice transplanter that has a seedling planting device having a seedling carrier and a plurality of planting claws attached to a traveling body and that performs continuous seedling planting work. [Background technology]

[0002] In conventional rice transplanters, a seedling planting device having a seedling carrier and a transplanting mechanism with a planting claw is attached to the rear of the traveling body. The transplanting mechanism of the seedling planting device is generally a type with two planting claws on one rotary case, and when the rotary case rotates once, the two planting claws each rotate once in the opposite direction relative to the rotary case. In other words, the planting claws rotate while revolving around the axis of the rotary case.

[0003] In seedling planting work using this type of rice transplanter, the seedling carrier with the seedling mat placed on it is fed intermittently left and right at specified intervals, while the planting claws facing the direction of the seedling carrier in front are rotated while revolving around the axis of the rotary case, causing the planting claws to reciprocate between the seedling carrier and the field surface, picking off the seedlings one by one from the seedling mat and planting them in the field. The operating cycle (planting cycle) of the planting claws in the seedling planting device is linked to the traveling speed of the traveling machine body, so that the planting interval (distance between seedlings) is kept constant even if the traveling speed changes.

[0004] The number of seedlings planted per unit area (generally 3.3 square meters) is not necessarily fixed, and the desired number of seedlings to be planted per unit area varies, for example, depending on the region or the user. In this regard, conventional rice transplanters are provided with a variable-row transmission that adjusts the interlocking relationship between the traveling speed and the planting cycle. In this case, the variable-row transmission changes the operating speed (planting speed) of the transplanting mechanism relative to the traveling speed, thereby changing the spacing between the rows and changing the number of seedlings to be planted per unit area.

[0005] In recent years, sparse planting has been practiced, with longer spacing between plants compared to standard planting, taking into consideration the growing conditions of seedlings planted in the field, but the longer the spacing between plants, the slower the planting speed must be. However, simply slowing down the planting speed by using a variable-speed planting device can cause the tips of the planting claws to be dragged across the field, causing the seedlings to fall forward or to float.

[0006] In this regard, Patent Documents 1 and 2 disclose the structure of a rice transplanter equipped with a variable speed member that transmits variable speed rotational power to the transplanting mechanism so that the planting claws are not dragged in the field during sparse planting. The variable speed member is configured to change the angular velocity during one rotation of the rotary case that constitutes the transplanting mechanism (rotating at a variable speed), and increases the speed at which the planting claws leave the field even during sparse planting. In the rice transplanter of Patent Document 1, a variable speed member is incorporated in the inter-row transmission device in the transmission case. In the rice transplanter of Patent Document 2, a variable speed member is provided downstream of the power transmission from the lateral feed drive mechanism of the seedling carrier. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 4376154 [Patent Document 2] JP 2003-189712 A Summary of the Invention [Problem to be solved by the invention]

[0008] Now, the power switching structure of the inter-row transmission includes a type that changes (switches) the speed in stages and a type that changes the speed continuously, but all of them tend to have a large number of parts and a complex structure. [Means for solving the problem]

[0009] The present invention has been made in consideration of the above-mentioned current situation, and aims to prevent the disadvantages of a variable velocity member while enjoying the advantages of the variable velocity member.

[0010] A rice transplanter according to one aspect of the present invention comprises a seedling planting device supported by a traveling section, and an inter-row transmission that transmits power to the seedling planting device and is capable of changing the working speed of the seedling planting device relative to the traveling speed of the traveling section. The inter-row transmission comprises an output shaft that transmits power to the seedling planting device, a first switching mechanism that can switch the power of the power transmission path to the output shaft into a plurality of stages, and a second switching mechanism that can switch the power of the power transmission path to the output shaft into a plurality of stages. The inter-row transmission is configured to be able to switch the power of the power transmission path to the output shaft into a plurality of gear stages by combining the power switched by the first switching mechanism and the power switched by the second switching mechanism. The plurality of gear stages include a plurality of constant-speed power gear stages and a plurality of variable-speed power gear stages, and only some of the plurality of variable-speed power gear stages are usable.

[0011] It is preferable that the remaining gears among the plurality of non-uniform power gears are disabled.

[0012] The number of the plurality of gear stages is greater than a predetermined number of gear stages that can be set during planting work of the seedling planting device.

[0013] The first switching mechanism may include a plurality of transmission gears supported in parallel on the output shaft, a counter shaft provided parallel to the output shaft, and a plurality of counter gears supported on the counter shaft and corresponding to each of the plurality of transmission gears, and the second switching mechanism may include an input shaft arranged concentrically with the output shaft, a plurality of gears fixed to the input shaft, and a gear slidably fitted on the counter shaft and meshing with any of the plurality of gears.

[0014] In addition, a variable speed gear is also placed inside the rotary case that makes up the transplanting mechanism, but this operates the planting claws to trace a long, non-circular movement locus in the vertical direction, and is different from the variable speed member referred to in the present invention (i.e., a member that imparts variable speed rotation (acceleration / deceleration) to the transmission elements of the power transmission system). Effect of the Invention

[0015] According to the present invention, in a plant spacing variable speed device that can change the working speed of the seedling planting device relative to the traveling speed of the traveling part, the power switching structure, which tends to be complicated, can be simplified. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a plan view of a rice transplanter according to an embodiment. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a perspective view showing the framework of the rice transplanter. [Figure 4] (A) is a perspective view showing the entire power transmission pathway, and (B) is a perspective view of the implantation mechanism. [Diagram 5] (A) is a side view of the power transmission path, (B) is a side view of the transplantation mechanism, and (C) is a diagram showing the trajectory of the transplantation claw. [Figure 6] FIG. 1A is a plan view showing the power transmission path, FIG. 1B is an external perspective view of the plant spacing change device, and FIG. 1C and FIG. 1D are external perspective views of the center case provided in the planting section. [Figure 7] 1A is an external perspective view of the plant spacing change device and the gear group in the center case, and FIG. 1B is an external perspective view of the gear group in the center case. [Figure 8] This is a transmission system diagram. [Figure 9] 1A is a plan view showing a power transmission path to a planting device, FIG. 1B is an isolated plan view of the end planting part of the power transmission path, and FIG. 1C is a schematic diagram of a bevel gear. [Figure 10] (A) and (B) are plan views showing the meshing state of the bevel gears, (C) and (D) are perspective views of the bevel gears, and (E) is a comparison diagram showing pairs of bevel gears side by side. [Figure 11] 1 is a diagram showing the relationship between the gear combination in the inter-row transmission and the number of rows planted. [Figure 12] FIG. 13 is a diagram showing the movement trajectory of the planting claws when set to 43 plants at an uneven speed. [Figure 13] FIG. 13 is a diagram showing the change in angular velocity of the planting claw when set to 43 stumps at an uneven speed. [Figure 14] FIG. 2 is a plan view showing the arrangement of the transplant mechanism in the first embodiment. [Figure 15] This is a plan cross-sectional view showing the power transmission structure inside the planting transmission case. [Figure 16] An enlarged plan cross-sectional view of the rear of the planting transmission case. [Figure 17] An enlarged side cross-sectional view of the rear of the planting transmission case. [Figure 18] FIG. 13 is a diagram showing the relationship between the rotational torque and the antiphase torque of the implantation mechanism. [Figure 19] FIG. 11 is a power transmission system diagram from the planting transmission case to the transplanting mechanism in the second embodiment. [Figure 20] FIG. 11 is a power transmission system diagram from the planting transmission case to the transplanting mechanism in the third embodiment. [Figure 21] FIG. 13 is a power transmission system diagram from the planting transmission case to the transplanting mechanism in the fourth embodiment. [Figure 22] FIG. 13 is an explanatory diagram illustrating a schematic diagram of a variable velocity member in a fourth embodiment. [Diagram 23] FIG. 13 is an explanatory diagram illustrating a schematic diagram of a variable velocity member in a fifth embodiment. [Figure 24] FIG. 23 is an explanatory diagram illustrating a schematic diagram of a variable velocity member in a sixth embodiment. [Diagram 25] FIG. 23 is an explanatory diagram illustrating a schematic diagram of a variable velocity member in the seventh embodiment. [Figure 26] FIG. 23 is an explanatory diagram illustrating a schematic diagram of a variable velocity member in the eighth embodiment. [Figure 27] FIG. 13 is an explanatory diagram illustrating a schematic diagram of a variable velocity member in a ninth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Next, an embodiment of the present invention will be described with reference to the drawings. The embodiment is applied to a riding rice transplanter (hereinafter, simply referred to as "rice transplanter"). In the following description, the terms "front, back, left, right" are used to specify directions, but these terms "front, back, back, left, right" are defined as the forward direction of the rice transplanter being the front. The front view direction is the direction opposite to the forward direction.

[0018] (1) Overview of the rice transplanter First, an overview of the rice transplanter will be described with reference to Figs. 1 to 5. As shown in Figs. 1 to 3, the rice transplanter has a traveling body 1 and a seedling planting device 2 arranged behind it. The traveling body 1 has front and rear wheels 3, 4, a steering seat 5, and a steering handle 6, while the seedling planting device 2 has a seedling carrier 7 on which seedling mats are placed, and a transplanting mechanism 8. The rice transplanter of the embodiment is an eight-row planting type, and therefore eight seedling mat placement areas are formed on the seedling carrier 7, and eight transplanting mechanisms 8 are arranged in a horizontal row behind the seedling planting device 2.

[0019] As shown in Fig. 3, the traveling body 1 has a framework 9 made up of a number of frame materials, and an engine 10 is supported at the front of the framework 9. A transmission case 11 is disposed behind the engine 10. As clearly shown in Fig. 4(A), a hydrostatic continuously variable transmission (HST) 12 is attached to the left side of the transmission case 11, and the power of the engine 10 is transmitted to the hydrostatic continuously variable transmission (HST) 12 by a belt 13. The engine 10 is covered by a bonnet 14. Furthermore, the portion of the traveling body 1 excluding the bonnet 14 is covered by a vehicle body cover 15.

[0020] A front axle unit 17 is attached to the left and right side surfaces of the transmission case 11, and front wheels 3 are attached to the front axle unit 17. A rear axle case 18 is disposed behind the transmission case 11, and rear wheels 4 are attached to a rear axle that protrudes sideways from the rear axle case 18. The transmission case 11 and the rear axle case 18 are connected by a joint material 19 that is longitudinal between the front and rear. Two rear pillars 20, one on the left and one on the right, are attached to the rear axle case 18, and the upper ends of the rear pillars 20 are fixed to a left and right horizontally elongated rear frame 9a (see Figure 3) that constitutes the rear end of the framework 9.

[0021] A link device 21 consisting of upper and lower link bodies (top link and lower link) is rotatably connected to the left and right rear support pillars 20, and the seedling planting device 2 is attached to the rear end of the link device 21. The link device 21 can be rotated by a hydraulic cylinder (lifting cylinder) 22 connected to the joint material 19. Therefore, by extending and retracting the hydraulic cylinder 22, the seedling planting device 2 is raised and lowered.

[0022] As can be easily understood from Fig. 4, power is transmitted from the inside of the transmission case 11 to the inside of the rear axle case 18 through a rear wheel drive shaft 23. The rotation of the rear wheel drive shaft 23 is transmitted to the rear wheels 4 through a group of gears provided in the rear axle case 18. In the rice transplanter of the embodiment, the seedling planting device 2 is provided with a soil leveling rotor 24, and power is transmitted to the soil leveling rotor 24 through a rotor drive shaft 25 protruding rearward from the rear axle case 18.

[0023] In this embodiment, an inter-row transmission 26 is attached to the right side of the rear axle case 18, and power is transmitted from the transmission case 11 to the inter-row transmission 26 via a planting power transmission shaft 27. The rotation of the planting power transmission shaft 27 is changed in speed by a group of gears built into the inter-row transmission 26, and is transmitted to the seedling planting device 2 by a PTO shaft 29.

[0024] The seedling planting device 2 has a main frame 28 that is long from left to right, and a center case 30 is fixed to the approximate middle part of the main frame 28 from left to right, and the power of the PTO shaft 29 is transmitted to a group of gears built into the center case 30. Four planting transmission cases 31 that extend backward are fixed to the rear surface of the main frame 28, and a pair of transplanting mechanisms 8, one on each side, are rotatably attached to the rear side of the planting transmission cases 31.

[0025] A planting drive shaft 32 long horizontally extends through the front side (base end side) of the planting transmission case 31, and the transplanting mechanism 8 is driven by the rotation of this planting drive shaft 32 (details will be described later). Power is transmitted to the planting drive shaft 32 from the PTO shaft 29 via a group of gears built into the center case 30. A lateral feed shaft 33 long horizontally is also attached to the center case 30, and the seedling carrier 7 moves laterally one pitch at a time by the rotation of the lateral feed shaft 33.

[0026] The seedling planting device 2 has a group of belts 34 on which the seedling mats are placed, and the belts 34 are wound around a pair of vertical feed shafts 35. When the seedling carrier 7 moves completely to either the left or right, the vertical feed shafts 35 rotate, and the seedling mats move down by one pitch.

[0027] As shown in Fig. 4(B), each transplanting mechanism 8 has one rotary case 36 and planting claw members 37 rotatably attached to both ends thereof, and the planting claw members 37 scrape and plant seedlings every 1 / 2 rotation of the rotary case 36. The rotary case 36 is set to rotate 1 / 2 rotation for every rotation of the PTO shaft 29. The number of rotations of the PTO shaft 29 is basically proportional to the traveling speed of the traveling machine body 1, but the planting interval (interplant interval) of the seedlings can be changed by changing the relationship between the traveling speed and the number of rotations of the PTO shaft 29 using the interplant transmission 26.

[0028] (2) Structure of the inter-row transmission and power transmission structure (upstream non-uniform speed member) The power transmission system from the inter-plant transmission 26 to the transplanting mechanism 8 will be described in detail below. First, the structure of the inter-plant transmission 26 and the power transmission structure therefor will be described mainly with reference to Figures 6 to 8. The inter-plant transmission 26 has an inter-plant case 40 that is split into two parts, front and rear, as shown in Figure 6(B), and a group of gears are arranged inside it as shown in Figures 6(A) and (C).

[0029] An input shaft 41 and an output shaft 42 are arranged inside the inter-plant case 40, and the rear end of the planting power transmission shaft 27 is connected to the input shaft 41 via a universal joint. A first gear 43 and a second gear 44 of the same diameter are fixed to the input shaft 41. Both gears 43, 44 have the same diameter, but the second gear 44 has slightly fewer teeth than the first gear 43.

[0030] The input shaft 41 and the output shaft 42 are arranged concentrically. A cylindrical intermediate shaft 45 is fitted to the input shaft 41 so as to be rotatable relative to the output shaft 42, and the intermediate shaft 45 is fitted to the output shaft 42 so as to rotate together with the output shaft 42 (non-rotatable relative state). A third gear 46 and a fourth gear 47 are fitted to the intermediate shaft 45 so as to be slidable but non-rotatable relative to the output shaft 42 by spline fitting or the like. Furthermore, an upstream variable speed first gear 48 and an upstream variable speed third gear 121 are fitted to the intermediate shaft 45 so as to be rotatable relative to the output shaft 42.

[0031] A cam-type main clutch 49 is provided on the output shaft 42. The main clutch 49 is made up of a fixed part 49a and a sliding part 49b, and the sliding part 49b is urged towards the fixed part 49a by a clutch spring 49c (see FIG. 7(C)). When the sliding part 49b moves away from the fixed part 49a against the clutch spring 49c, the power transmission from the input shaft 41 to the output shaft 42 is cut off. When the seedling planting device 2 is raised, such as when traveling on a road or turning, the main clutch 49 is disengaged. The main clutch 49 is disengaged by lowering the main clutch operating shaft 50.

[0032] An idle shaft 51 extending parallel to the input shaft 41 and the output shaft 42 in a side view is rotatably supported inside the inter-plant case 40, and a fifth gear 52 capable of meshing with the first gear 43 or the second gear 44 is fitted onto this idle shaft 51 by spline fitting or the like so as to be slidable but non-rotatable relative to the first gear 43 or the second gear 44. The fifth gear 52 has about twice as many teeth as the first gear 43 or the second gear 44, and can select a first position in which it meshes with the first gear 43, or a second position in which it meshes with the second gear 44.

[0033] An upstream variable speed fourth gear 122 that is always meshed with the upstream variable speed third gear 121, a sixth gear 54 that meshes with and separates from the third gear 46, a seventh gear 55 that meshes with and separates from the fourth gear 47, and an upstream variable speed second gear 56 that is always meshed with the upstream variable speed first gear 48 are fixed to the idle shaft 51. The ratio of the number of teeth of the seventh gear 55 to the fourth gear 47 is set to be smaller than the ratio of the sixth gear 54 to the third gear 46. Therefore, the rotation speed of the intermediate shaft 45 (and the output shaft 42) is lower when the fourth gear 47 and the seventh gear 55 are meshed with each other than when the third gear 46 and the sixth gear 54 are meshed with each other.

[0034] The upstream variable speed first gear 48 and the upstream variable speed second gear 56 have a non-circular profile such as an ellipse, and the number of teeth is set to be the same. Therefore, when the rotation of the idle shaft 51 is transmitted to the intermediate shaft 45 and the output shaft 42 via the variable speed gears 48, 56, the rotation speeds of the idle shaft 51 and the output shaft 42 are the same, and the output shaft 42 rotates with its angular velocity periodically changing during one rotation. The variable speed gears 48, 56 are non-circular and the meshing phase is always fixed, so that they are always kept in meshing state. Similarly, the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 also have a non-circular profile such as an ellipse, and the number of teeth is set to be the same. Therefore, when the rotation of the idle shaft 51 is transmitted to the intermediate shaft 45 and the output shaft 42 via both the variable speed gears 48, 56, the rotation speeds of the idle shaft 51 and the output shaft 42 are the same, and the output shaft 42 rotates with its angular velocity periodically changing during one rotation. In other words, the upstream variable speed first gear 48 and the upstream variable speed second gear 56 are a non-circular gear pair such as eccentric gears, and have a large acceleration / deceleration ratio (non-uniform speed ratio). The upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 are also a non-circular gear pair such as eccentric gears, but have a small acceleration / deceleration ratio (non-uniform speed ratio).

[0035] Here, in the rotary case 36, for example, when sparsely planting at 37 stalks / m2, acceleration and deceleration are applied so that the maximum speed phase (the phase at which the operating speed of the planting claw 96 is at its maximum) of each planting claw member 37 is near the bottom dead center, and in addition, in this embodiment, the upstream variable speed first gear 48 and the upstream variable speed second gear 56 provided in the inter-plant transmission 26 apply a slightly larger acceleration and deceleration to the rotational power from the inter-plant case 40 to output a variable speed rotational power. Therefore, since the acceleration and deceleration ratio (variable speed ratio) is larger than the combination of the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122, the operating speed of the planting claw 96 near the bottom dead center of the operating trajectory is greatly increased. In addition, the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 impart slightly smaller acceleration and deceleration to the rotational power from the inter-plant case 40 to output variable speed rotational power. Therefore, since the acceleration / deceleration ratio (variable speed ratio) is smaller than the combination of the upstream variable speed first gear 48 and the upstream variable speed fourth gear 56, the operating speed of the planting claw 96 near the bottom dead center of its operating trajectory is increased slightly. The upstream variable speed first to fourth gears 48, 56, 121, 122 correspond to the upstream variable speed members on the inter-plant speed change device 26 side that transmit the variable speed rotational power to the transplanting mechanism 8.

[0036] A first intermediate clutch 57 that can be freely engaged and disengaged is provided between the fourth gear 47 and the upstream variable speed first gear 48. When the fourth gear 47 slides further rightward from the state shown in FIG. 8 after having been engaged with the seventh gear 55, the first intermediate clutch 57 engages. When the first intermediate clutch 57 is engaged, the power of the idle shaft 51 is transmitted to the output shaft 42 via the upstream variable speed second gear 56 and the upstream variable speed first gear 48. When the first intermediate clutch 57 is engaged, the third gear 46 and the fourth gear 47 rotate idly. Therefore, the first intermediate clutch 57 functions to connect and disconnect the intermediate shaft 45 and the upstream variable speed first gear 48.

[0037] The third gear 46 and the upstream variable speed third gear 121 are also provided with a second intermediate clutch 123 that can be freely engaged and disengaged. When the third gear 46 slides further leftward from the state shown in FIG. 8 after once engaging with the sixth gear 54, the second intermediate clutch 123 engages with the intermediate shaft 45. When the second intermediate clutch 123 is engaged, the power of the idle shaft 51 is transmitted to the output shaft 42 via the upstream variable speed fourth gear 122 and the upstream variable speed third gear 121. In this case, too, if the second intermediate clutch 123 is engaged, the third gear 46 and the fourth gear 47 rotate freely. Therefore, the second intermediate clutch 123 functions to connect and disconnect the intermediate shaft 45 and the upstream variable speed third gear 121.

[0038] The fifth gear 52 slides to switch between two stages, and the intermediate shaft 45 slides to switch between four stages. Therefore, there are eight stages of combination (speed switching) in total. For example, the number of plants per 3.3 square meters can be changed to 37 to 85 plants, covering almost all areas of sparse planting and dense planting. FIG. 11 shows the relationship between the gear combination and the number of planted plants in the embodiment. When the first gear 43 and the fifth gear 52 are engaged, if the fourth gear 47 and the seventh gear 55 are engaged, the number of planted plants is set to d plants with a uniform speed, and if the third gear 46 and the sixth gear 54 are engaged, the number of planted plants is set to f plants with a uniform speed. If the second intermediate clutch 123 is engaged, the number of planted plants is set to b plants with a non-uniform speed. When the second gear 44 and the fifth gear 52 are engaged, engaging the fourth gear 47 and the seventh gear 55 sets the number of stalks to be planted at a constant speed, c stalks, and engaging the third gear 46 and the sixth gear 54 sets the number of stalks to be planted at a constant speed, e stalks. Engaging the first intermediate clutch 57 sets the number of stalks to be planted at a non-uniform speed. In this case, the numbers of stalks indicated by the letters are in alphabetical order.

[0039] Here, the upstream variable speed first to fourth gears 48, 56, 121, 122 are attached to the intermediate shaft 45 or the idle shaft 51 by adjusting the mounting phase, so that the maximum speed phase at which the planting claw 96 in the transplanting mechanism 8 operates at the maximum speed can be set and changed in the range before and after the bottom dead center. FIG. 12 shows, as an example, the movement trajectory of the planting claw 96 when set to 43 stumps at variable speed. The symbol MS1 in FIG. 12 is the maximum speed phase when the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 are attached so that the planting claw 96 operates at the maximum speed before (upstream) the bottom dead center, and MS2 is the maximum speed phase when the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 are attached so that the planting claw 96 operates at the maximum speed near the bottom dead center. Symbol MS3 indicates the maximum speed phase when the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 are assembled so that the operating speed of the planting claws 96 becomes maximum speed behind the bottom dead center (downstream side).

[0040] Depending on the relationship with the assembly accuracy, for example, the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 can be assembled so that the front side (upstream side) of the bottom dead center is the highest speed phase MS1, the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 can be assembled so that the vicinity of the bottom dead center is the highest speed phase MS2, and further, the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 can be assembled so that the rear side (downstream side) of the bottom dead center is the highest speed phase MS3. That is, for example, in relation to the assembly accuracy, the highest speed phase can be changed to around the bottom dead center even when there is a concern that the torsion of the power transmission system is large and the operating period of the planting claw 96 is shifted, or when the torsion of the power transmission system is small and vibration of the power transmission system is to be suppressed as much as possible. In this way, it is possible to suppress the so-called "jerking" of the planting claw 96 and the vibration of the power transmission system. It goes without saying that the upstream variable speed first gear 48 and the upstream variable speed second gear 56 may be assembled to the intermediate shaft 45 and the idle shaft 51 by adjusting the mounting phase.

[0041] A fertilizer application rotating shaft 58 extending parallel to the input shaft 41 and the output shaft 42 is rotatably disposed on the upper part of the inter-plant case 40, and an eighth gear 59 meshing with the first gear 43 is fitted onto the fertilizer application rotating shaft 58 so as to be relatively rotatable. Power is transmitted from the fertilizer application rotating shaft 58 to a fertilizer application drive shaft 62 via a bevel gear 61.

[0042] As shown in Fig. 7(A), the inter-plant transmission 26 has two operating shafts, a first operating shaft 63 and a second operating shaft 64. These operating shafts 63, 64 are oriented longitudinally and are exposed in front of the inter-plant case 40. As can be seen from Fig. 6(B), the first operating shaft 63 can be slid back and forth with a first lever 65, and the second operating shaft 64 can be slid back and forth with a second lever 66. The first operating shaft 63 is for sliding the fifth gear 52, and has a shifter for sliding the fifth gear 52. The second operating shaft 64 is for sliding the intermediate shaft 45, and has a shifter that engages with the intermediate shaft 45.

[0043] (3) Internal structure of the center case Next, the internal structure of the center case 30 (i.e., the planting section transmission) will be described with reference to Figures 6 to 8. The center case 30 is made up of a shell body divided into two parts, left and right, and holds an input shaft 69 that is longitudinally long from front to rear so as to be freely rotatable. The front end of the input shaft 69 and the rear end of the PTO shaft 29 are connected via a universal joint.

[0044] A left-right long intermediate shaft 70 is disposed inside the center case 30, and the rotation of the input shaft 69 is transmitted to the intermediate shaft 70 by a pair of first bevel gears 71a, 71b. A transverse feed drive shaft 72 is disposed inside the center case 30 in a left-right long orientation, and the transverse feed shaft 33 is connected to the transverse feed drive shaft 72.

[0045] Three lateral feed amount adjustment driven gears 73 are fixed to the lateral feed drive shaft 72, while three lateral feed amount adjustment main gears 74 are loosely fitted to the intermediate shaft 70 in correspondence with the lateral feed amount adjustment driven gears 73. Power is selectively transmitted from the intermediate shaft 70 to only one of the three lateral feed amount adjustment main gears 74 by a slide key 76 (see FIG. 8). The slide key 76 is slid by a slide lever 77 shown in FIG. 6(C)(D) and FIG. 7(A)(B).

[0046] The pair of lateral feed amount adjustment gears 73, 74 have different ratios of the number of teeth, and changing the combination of the lateral feed amount adjustment gears 73, 74 changes the rotation ratio of the lateral feed drive shaft 72 to the PTO shaft 29. As a result, the lateral feed pitch of the seedling carrier 7 changes, and the amount of seedlings removed changes.

[0047] The center case 30 has a protruding portion 30a extending downward toward the rear, and a planting output shaft 78 elongated from side to side is rotatably held on this protruding portion 30a, and power is transmitted to the planting output shaft 78 via a first relay gear 79 fixed to the intermediate shaft 70, a second relay gear 80 fitted to the lateral feed drive shaft 72 so as to be relatively rotatable, a third relay gear 82 rotatably held on the center case 30 via an idle shaft 81, and a fourth relay gear 84. The fourth relay gear 84 is attached to the planting output shaft 78 via a sleeve 83.

[0048] The ratio of the number of teeth of the first bevel gears 71a, 71b is 1:1, and the number of teeth of the first relay gear 79, the second relay gear 80, and the fourth relay gear 84 is 1:1:1. Therefore, the rotation speed of the PTO shaft 29 and the planting output shaft 78 is 1:1. Since the third relay gear 82 is simply an idle gear, the number of teeth does not affect the rotation speed of the fourth relay gear 84.

[0049] The planting output shaft 78 and the planting drive shaft 32 located adjacent thereto are connected by a coupling (sleeve) 86. In addition, an intermediate shaft 85 is disposed between the planting drive shafts 32 adjacent to each other on the left and right, and the drive shafts 32 and the intermediate shafts 85 are also connected by a coupling 86. Therefore, each planting drive shaft 32 rotates integrally. The planting drive shaft 32 is divided into sections for each transplanting mechanism 8, and adjacent planting drive shafts 32 are connected by a spring 86. It is also possible to form the planting output shaft 78, each planting drive shaft 32, and the intermediate shaft 85 into a single structure made of a single rod material.

[0050] (4) Structure of implant mechanism and power transmission structure Next, the structure of the transplanting mechanism 8 and the power transmission structure therefor will be described. These constitute the main parts of the embodiment, and are mainly shown in Figures 8 to 10 (see also Figure 6(A)). The planting transmission case 31 has a hollow structure, and as shown in Figure 8, a planting transmission shaft 87 long in the front and rear directions is rotatably held inside it.

[0051] Power is transmitted to the planting transmission shaft 87 from the planting drive shaft 32 via a second bevel gear pair 88a, 88b. Of the second bevel gear pair 88a, 88b, the bevel gear 88b that rotates concentrically with the planting transmission shaft 87 is attached to a torque limiter 89 fitted to the planting transmission shaft 87. The torque limiter 89 has a spring 90, and when a load of a predetermined value or more is applied to the planting transmission shaft 87, the torque limiter 89 disengages and the power transmission is interrupted.

[0052] A horizontally long planting central shaft 91 is rotatably held at the rear (tip) side of the planting transmission case 31 via a pair of left and right bearings 104. The planting central shaft 91 protrudes to the left and right outside of the planting transmission case 31, and a sun gear 92 built into the rotary case 36 is fixed to its protruding end. Although details are omitted, the rotary case 36 is rotatably held at the rear end of the planting transmission case 31.

[0053] The rotary case 36 has a hollow structure in which two shell bodies, one on the left and one on the right, are stacked together, and the sun gear 92 described above is disposed in the longitudinal middle portion, and the intermediate gear 93 is disposed outside of that, and the planetary gear 94 is disposed outside of that. Each gear 92, 93, 94 is non-circular and eccentric. The planting claw member 37 is fixed to the unit shaft 95 fixed to the planetary gear 94.

[0054] As shown in Figure 5, the planting claw member 37 is equipped with a planting claw 96 and an ejection rod 97. As shown in Figure 5(C), the planting claw 96 cuts out a single seedling from the seedling mat and moves it to the field. When the seedling is near the bottom dead center, the ejection rod 97 moves forward relative to the planting claw 96, thereby planting the seedling in the field.

[0055] As shown in Fig. 9, power is transmitted from the planting transmission shaft 87 to the planting central shaft 91 by a downstream variable speed bevel gear pair 98, 99. That is, a downstream variable speed driving bevel gear 98 is fixed to the planting transmission shaft 87 via a coupling 100, while a downstream variable speed driven bevel gear 99 is fitted to the planting central shaft 91, and variable speed rotation is transmitted from the planting transmission shaft 87 to the planting central shaft 91 by these variable speed bevel gear pairs 98, 99.

[0056] The downstream variable speed driven bevel gear 98 has a stepped boss body 98a, and a coupling 100 is fitted into the small diameter portion of the boss body 98a. A bearing 101 is fitted into the boss body 98a. The coupling 100 is fixed to the planting transmission shaft 87 by welding and is held so as to be unable to rotate relative to the planting transmission shaft 87. The downstream variable speed driven bevel gear 99 is fitted into the planting central shaft 91 so as to be able to rotate relative to the planting transmission shaft 87, and has a cam portion 103 that meshes with a stripe stop clutch 102. An operation ring 105 is welded integrally to the stripe stop clutch 102.

[0057] The row stop clutch 102 is held slidably on the planting central shaft 91 but unable to rotate relative to it. The row stop clutch 102 is normally pressed into meshing engagement with the downstream variable speed driven bevel gear 99 by a spring 106. When the operating rod 129 is operated, the row stop clutch 102 moves away from the downstream variable speed driven bevel gear 99 along the axis of the planting central shaft 91, and power to the planting central shaft 91 is cut off.

[0058] For example, when planting on the edge of a field, some of the four pairs of transplanting mechanisms 8 may not be desired to operate, and in such a case, the row stop clutch 102 can be operated to stop the function of some of the transplanting mechanisms 8. In other words, the row stop function that reduces the number of planting rows is achieved.

[0059] (5).Downstream inconstant velocity member In the embodiment, the downstream variable speed bevel gear pair 98, 99 is provided with a function of rotating at a variable speed (accelerating and decelerating) (the downstream variable speed bevel gear pair 98, 99 is adopted as the downstream variable speed member). This point will be explained mainly based on Fig. 10 and Fig. 9(C). As shown in Fig. 10(E), when forming a large number of teeth 107 on the downstream variable speed main drive bevel gear 98, the distance from the tip of each tooth 107 to the axis O1 is set to gradually increase and decrease again. That is, each tooth 107 has a pitch cone angle minimum part 108 where the distance from the axis O1 to the tip is the narrowest, and a pitch cone angle maximum part 109 where the distance from the axis O1 to the tip is the widest, and the interval between the two gradually changes.

[0060] In other words, as shown in Fig. 9(C), the pitch circle 110 of each tooth 107 is nearly elliptical and eccentric with respect to a perfect circle (reference numeral 110' denotes the pitch circle in the case of a perfect circle). From the opposite perspective, in a normal bevel gear, the outer circumferential surface of the imaginary cone is inclined at the same angle with respect to the axis at every position, but in the downstream variable speed main drive bevel gear 98 of the embodiment, the inclination angle θ1 of the outer circumferential surface of the imaginary cone (see Figs. 10(A) and 10(C)) is gradually changed as the outer circumferential surface moves in the circumferential direction.

[0061] The downstream variable speed driven bevel gear 99 has twice as many teeth 112 as the downstream variable speed driven bevel gear 98. As can be clearly seen from Figures 10(A) and 10(B), the axial position of each tooth 112 is slightly shifted. In other words, in the downstream variable speed driven bevel gear 99 of the embodiment, as in the downstream variable speed driven bevel gear 98, the inclination angle θ2 (see Figure 10(A)) of the outer circumferential surface of the imaginary cone gradually changes as the outer circumferential surface moves in the circumferential direction.

[0062] Since the downstream variable speed driven bevel gear 99 has twice the number of teeth of the downstream variable speed driven bevel gear 98, the downstream variable speed driven bevel gear 99 has two pitch cone angle maximum portions 113 and two pitch cone angle minimum portions 114. Therefore, as shown in Fig. 9(C), the pitch circle 115 of the downstream variable speed driven bevel gear 99 is substantially elliptical and symmetrical with respect to the axis O2 (in Fig. 9(C), the pitch circle in the case of a perfect circle is indicated by the symbol 115'). In other words, the downstream variable speed bevel gear pair 98, 99 changes the pitch cone angles θ1, θ2 continuously along the rotation direction while keeping the cone distance γ (see Fig. 10(C)) constant. As can be seen from the above description, the downstream variable speed bevel gear pair 98, 99 as the downstream variable speed member is a single stage, and does not perform a speed change operation (no speed switching) like the upstream variable speed first to fourth gears 48, 56, 121, 122 as the upstream variable speed member.

[0063] In this way, by making the pitch circles 110, 115 of the downstream variable speed bevel gears 98, 99 nearly elliptical and eccentric with respect to a perfect circle centered on the rotation axes O1, O2, and then making the outer diameter shapes perfect circles, the pair of downstream variable speed bevel gears 98, 99 can be formed to a size comparable to that of normal bevel gears, and the installation space for the pair of downstream variable speed bevel gears 98, 99 in the power transmission system can be made smaller and more compact. The idea behind manufacturing the downstream variable speed bevel gears 98, 99 in this case is to cut a distorted cone shape formed with a constant cone distance with a cylinder having a common rotation axis O1, O2, to make the outer diameter shape a perfect circle.

[0064] Here, the downstream variable speed bevel gear pair 98, 99 can also be adjusted in the same manner as the upstream variable speed first to fourth gears 48, 56, 121, 122, by adjusting the mounting phase, and the above-mentioned maximum speed phase can be changed in a direction further away from the bottom dead center. FIG. 13 shows, as an example, the change in angular velocity of the planting claw 96 when the variable speed is set to 43 stumps. The thick dashed line in FIG. 13(A) shows the case where the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 are assembled so that the front side (upstream side) of the bottom dead center is the maximum speed phase MS1, and then the downstream variable speed bevel gear pair 98, 99 is assembled so that the front side of the bottom dead center is the maximum speed phase MS1' (see FIG. 12). The thick solid line in FIG. 13(B) shows the case where the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 are assembled and the downstream variable speed bevel gear pair 98, 99 are assembled so that the vicinity of the bottom dead center is the highest speed phase MS2. The thick two-dot chain line in FIG. 13(C) shows the case where the upstream variable speed third gear 121 and the upstream variable speed fourth gear 122 are assembled so that the rear side (downstream side) of the bottom dead center is the highest speed phase MS3, and then the downstream variable speed bevel gear pair 98, 99 is assembled so that the rear side of the bottom dead center is the highest speed phase MS3' (see FIG. 12). When configured in this way, the operating speed of the planting claw 96 is increased near the bottom dead center, and the effect of accurately and quickly releasing the planting claw 96 from the bottom dead center can be further promoted.

[0065] (6) Summary Figure 5(C) shows the relationship between the number of plants planted per 3.3 m2 and the movement trajectory of the planting claw 96. As can be seen from this figure, even if the planting claw 96 rises directly above the bottom dead point during dense planting, when sparse planting occurs, the planting claw 96 is unable to escape properly, causing the seedlings to tip forward.

[0066] In the embodiment, the planting speed change device 26 is provided with the upstream variable speed first to fourth gears 48, 56, 121, 122, and the seedling planting device 2 is provided with the downstream variable speed bevel gear pair 98, 99, so that the planting claw member 37 accelerates and rotates so that the operating speed becomes faster when the planting claw 96 is located near the bottom dead center. Therefore, the planting claw 96 quickly moves away from the bottom dead center, and as a result, the phenomenon of the planting claw 96 tipping the seedling forward can be prevented.

[0067] In the embodiment, the variable speed members are arranged separately in the inter-plant transmission 26 and the seedling planting device 2, so the proportion of non-uniform speed rotation between the inter-plant transmission 26 and the downstream variable speed bevel gear pair 98, 99 is smaller than in the past. As a result, torsion occurring in the transmission elements (PTO shaft 29, planting drive shaft 32, planting transmission shaft 87, etc.) constituting the power transmission system is significantly suppressed, ensuring smooth movement of the transplanting mechanism 8. In addition, rattle occurring in the power transmission system can be suppressed, so that problems such as timing of non-uniform speed being shifted and disturbance of the planting posture of the seedlings can be prevented.

[0068] Now, the transplanting mechanism 8 has the planting claw members 37 attached to both ends of the elongated rotary case 36 in a swingable manner, so that the planting claw members 37 themselves act as weights and generate a large inertial force. Moreover, a large load is generated when the seedlings are picked up, and a negative load is generated thereafter. In other words, the swinging of the planting claw members 37 generates large torque fluctuations in the rotation of the transplanting mechanism 8, cyclically changing from overload to no load to negative load. Such torque fluctuations become noticeable when the resonant rotation speed is exceeded, even if the transplanting mechanism 8 rotates at a constant speed during dense planting (this is because the transplanting mechanism 8 rotates at a higher speed during dense planting than during sparse planting).

[0069] More specifically, even if the transplanting mechanism 8 rotates at a constant speed, when one planting claw member 37 leaves the field, the other planting claw member 37 transitions to picking up seedlings, and therefore it can be said that the two planting claw members 37 act to cancel each other's load fluctuations. However, because a large torque is required to pick up seedlings, the movement of the two planting claw members 37 alone is not strong enough to level out the torque fluctuations. For this reason, the transplanting mechanism 8 does not rotate smoothly, and a phenomenon known as "jumping" is likely to occur.

[0070] In contrast, if the downstream variable speed bevel gear pair 98, 99 is used to impart a slightly variable speed rotation to the transplanting mechanism 8 even in a densely planted state as in the embodiment, the planting claw members 37 scrape off the seedlings while accelerating using inertial force, and after the seedlings are scraped off, the transplanting mechanism 8 decelerates, thereby preventing a large inertial force from acting on the transplanting mechanism 8. This makes it possible to level out the load fluctuations (or torque fluctuations) acting on the transplanting mechanism 8 and ensure smooth rotation.

[0071] (7) First embodiment of the antiphase torque generating member Next, a first example of the opposite phase torque generating member 130 will be described with reference to Fig. 8 and Figs. 14 to 18. The rice transplanter of the embodiment is equipped with an opposite phase torque generating member 130 that applies an opposite phase torque Tan, which is in the opposite phase to the rotation torque T, to the rotation torque T of the transplanting mechanism 8 based on the non-uniform rotational power of the upstream non-uniform speed and downstream non-uniform speed bevel gear pair 98, 99. In the first example, the opposite phase torque generating member 130 is provided for each of the multiple (four) planting transmission cases 31. Since each planting transmission case 31 is provided with a row stop clutch 102, there is an opposite phase torque generating member 130 for each combination of the planting transmission case 31 and the row stop clutch 102, a total of four sets.

[0072] As shown in Figures 14 to 17, a hollow end case 131 is integrally provided at the rear end of the planting transmission case 31. The end case 131 may be a separate structure that is detachably attached to the rear end of the planting transmission case 31. The inside of the planting transmission case 31 and the inside of the end case 131 are connected to each other. A planting branch shaft 132 that is long in the front and rear directions is rotatably supported via a bearing at the connecting portion between the inside of the planting transmission case 31 and the inside of the end case 131. A leveling bevel gear 133 that is constantly meshed with the downstream variable speed driven bevel gear 99 is provided at the front end of the planting branch shaft 132. The leveling bevel gear 133 and the downstream variable speed driven bevel gear 98 are in a positional relationship in which they face each other (opposite each other) at the front and rear of the planting central shaft 91.

[0073] The leveling bevel gear 133 is formed in the same shape as the downstream variable speed driven bevel gear 98. That is, the leveling bevel gear 133 has the same number of teeth as the downstream variable speed driven bevel gear 98, and is formed in a shape in which the pitch cone angle changes continuously along the rotation direction while keeping the cone distance constant, similar to the downstream variable speed driven bevel gear 98. Therefore, the leveling bevel gear 133 and thus the planting branch shaft 132 rotate in the opposite direction at the same speed as the downstream variable speed driven bevel gear 98 (rotating at twice the speed compared to the downstream variable speed driven bevel gear 99).

[0074] The rear end of the planting branch shaft 132 protrudes from the upper and lower middle parts of the end case 131. An eccentric shaft 134 extending parallel to the planting branch shaft 132 is fixed to the protruding part on the rear end side. The axis of the eccentric shaft 134 is eccentric with respect to the center of rotation of the planting branch shaft 132. Therefore, the planting branch shaft 132 and the eccentric shaft 134 are crankshaft-shaped (function as a crankshaft). A locking pin 135 is attached to the lower side of the end case 131. A tension spring 136 is mounted on the eccentric shaft 134 and the locking pin 135 as a means for generating a reverse phase torque. The tension spring 136 constantly urges the eccentric shaft 134 in a direction to move the eccentric shaft 134 downwards of the planting branch shaft 132. When the eccentric shaft 134 passes directly above the planting branch shaft 132, the tension spring 136 is set to cross the fulcrum. In the first embodiment, the planting branch shaft 132, the eccentric shaft 134 and the tension spring 136 constitute the antiphase torque generating member 130.

[0075] In addition, a driving spur gear 137 is fixed to the protruding portion on the rear end side of the planting branch shaft 132. A power take-off shaft 138 extending parallel to the planting branch shaft 132 is rotatably supported on the upper side inside the end case 131. A driven spur gear 139 is fixed to the front side of the power take-off shaft 138. The driving spur gear 137 and the driven spur gear 139 are constantly meshed. The rear end side of the power take-off shaft 138 protrudes backward from the rear surface of the end case 131. The rotational power of the planting transmission shaft 87 is transmitted to the power take-off shaft 138 via the downstream variable speed bevel gear pair 98, 99, the leveling bevel gear 133, the planting branch shaft 132, the driving spur gear 137 and the driven spur gear 139. When an optional device such as a chemical sprayer is attached to the seedling planting device 2, the rotational power of the power take-off shaft 138 is transmitted to the optional device.

[0076] Here, Fig. 18 shows, as an example, the relationship between the rotational torque T (fluctuation torque) of the planting central shaft 91 in the transplanting mechanism 8, the antiphase torque Tan, and the composite torque Tco obtained by combining these. The dashed line in Fig. 18 represents the rotational torque T (fluctuation torque) of the planting central shaft 91, and the rotational torque T is greatest near the bottom dead center where each planting claw 96 of the planting claw member 37 plants the seedlings. The two-dot chain line in Fig. 18 represents the antiphase torque Tan generated by the antiphase torque generating member 130 (the planting branch shaft 132, the eccentric shaft 134, and the tension spring 136), and the antiphase torque Tan is greatest near the bottom dead center where each planting claw 96 of the planting claw member 37 plants the seedlings.

[0077] The elastic restoring force of the tension spring 136 is transmitted to the planting central shaft 91 through the leveling bevel gear 133 provided on the planting branch shaft 132 and the downstream non-uniform speed driven bevel gear 99. As a result, as shown by the solid line in FIG. 18, the rotational torque T and the opposite phase torque Tan are synthesized, and the synthesized torque Tco is transmitted to the transplanting mechanism 8. In other words, the rotational torque T that is leveled (cancelled) by the synthesis of the opposite phase torque Tan is transmitted to the transplanting mechanism 8. Therefore, the load fluctuation (which may be called torque fluctuation) acting on the transplanting mechanism 8 is leveled, and the smooth rotation of the transplanting mechanism 8 can be ensured. This suppresses the occurrence of a phenomenon called "jumping," and allows the seedlings to be planted in the appropriate planting position.

[0078] As is clear from the above description and from Figures 8 and 14 to 18, the rice transplanter is equipped with a transmission case 11 that changes the speed of the power of the engine 10 mounted on the traveling body 1, a seedling planting device 2 having a transplanting mechanism 8 with planting claws 96 that draw a non-circular operating trajectory, a plant spacing transmission 26 that changes the operating speed of the transplanting mechanism 8 relative to the traveling speed of the traveling body 1 to change the plant spacing, and variable speed members 98, 99 that transmit variable speed rotational power to the transplanting mechanism 8. The rice transplanter further includes an anti-phase torque generating member 130 that adds an anti-phase torque Tan that is in the opposite phase to the rotational torque T of the transplanting mechanism 8 based on the variable speed rotational power. Therefore, the anti-phase torque Tan from the anti-phase torque generating member 130 cancels the rotational torque T of the transplanting mechanism 8 due to the variable speed rotational power, and the load fluctuation (which may be called torque fluctuation) acting on the transplanting mechanism 8 is leveled out, ensuring smooth rotation of the transplanting mechanism 8. This prevents the occurrence of a phenomenon known as "shuttleball," allowing seedlings to be planted in the correct planting position.

[0079] In particular, the power transmission system from the inter-plant transmission 26 to the transplanting mechanism 8 comprises intersecting rotating shafts 87, 91, and these intersecting rotating shafts 87, 91 are configured to transmit power via a bevel gear pair. The bevel gear pair is configured as a variable speed gear pair 98, 99 as the variable speed member, and the opposite phase torque generating member 130 is connected to the downstream variable speed gear 99 of the variable speed gear pair 98, 99. Therefore, the variable speed gear pair 98, 99, which is an existing member, can be utilized, which is advantageous in terms of cost.

[0080] (8) Second and third embodiments of the antiphase torque generating member Next, a second embodiment of the anti-phase torque generating member 130 will be described with reference to Fig. 19. The second embodiment differs from the first embodiment in that the end case 131 is eliminated from the rear end side of the planting transmission case 31, and the anti-phase torque generating member 130 is disposed at the rear side within the planting transmission case 31.

[0081] In this case, external teeth 141 are formed on the outer periphery of the operation ring 105 of the row stop clutch 102. A leveling spur gear 143 rotatably supported on the rear side of the planting transmission case 31 is meshed with the external teeth 142 of the operation ring 105. The rotation center axis 144 of the leveling spur gear 143 extends parallel to the planting center axis 91. A locking pin 145 is erected on one side of the leveling spur gear 143.

[0082] A tension spring 146 is mounted between the locking pin 145 and the inner peripheral wall of the planting transmission case 31 as a means for generating an antiphase torque. The tension spring 146 constantly urges the locking pin 145 in a direction away from the operation ring 105. The tension spring 146 expands and contracts as the leveling spur gear 143 rotates. The leveling spur gear 143 and the tension spring 146 form a kind of crank structure. In the second embodiment, the operation ring 105 of the row stop clutch 102, the leveling spur gear 143, the locking pin 145, and the tension spring 146 constitute the antiphase torque generating member 130. In other words, the antiphase torque generating member 130 is located downstream of the row stop clutch 102 in the planting transmission case 31. In the second embodiment, similarly to the first embodiment, an antiphase torque generating member 130 exists for each combination of a total of four planting transmission cases 31 and row stop clutches 102.

[0083] When configured as described above, the elastic restoring force of the tension spring 146 is transmitted from the leveling spur gear 143 through the operation ring 105 of the row stop clutch 102 to the planting central shaft 91. As a result, similar to the first embodiment (as shown by the solid line in FIG. 18), the rotational torque T and the opposite phase torque Tan are combined, and the combined torque Tco is transmitted to the transplanting mechanism 8, ensuring smooth rotation of the transplanting mechanism 8. Therefore, similar to the first embodiment, the occurrence of the phenomenon known as "jumping" is suppressed, and the seedlings can be planted in the correct planting position.

[0084] In addition, since the anti-phase torque generating member 130 is disposed downstream of the row stop clutch 102 in the planting transmission case 31, the anti-phase torque generating member 130 is located near the transplanting mechanism 8, which is the source of the load fluctuation. This has the effect of offsetting the rotational torque T of the transplanting mechanism 8 with the anti-phase torque Tan, i.e., of leveling out the load fluctuation. Moreover, since the anti-phase torque Tan is not generated when the row stop clutch 102 is in the power interrupted state, there is no risk of unnecessary torque being transmitted to the periphery of the transplanting mechanism 8.

[0085] Fig. 20 shows a third embodiment of the anti-phase torque generating member 130. The third embodiment shown in Fig. 20 is a modified example of the second embodiment described above. The third embodiment is similar to the second embodiment in that the anti-phase torque generating member 130 is disposed on the rear side of the planting transmission case 31 and downstream of the row stop clutch 102, but differs from the second embodiment in that the anti-phase torque generating member 130 is provided separately and independently from the row stop clutch 102.

[0086] In this case, a first leveling spur gear 152 is fixed to the planting central shaft 91 on the opposite side of the row stop clutch 102 across the downstream variable speed driven bevel gear 99. A second leveling spur gear 153 rotatably supported on the rear side of the planting transmission case 31 is meshed with the first leveling spur gear 152. A rotation central shaft 154 of the second leveling spur gear 153 extends parallel to the planting central shaft 91. A locking pin 155 is erected on one side of the second leveling spur gear 153.

[0087] A tension spring 156 is mounted on the locking pin 155 and the inner peripheral wall of the planting transmission case 31 as a means for generating an antiphase torque. The tension spring 156 constantly urges the locking pin 155 in a direction away from the first leveling spur gear 152. The tension spring 156 expands and contracts due to the rotation of the second leveling spur gear 153. The second leveling spur gear 153 and the tension spring 156 form a kind of crank structure. In the third embodiment, the first and second leveling spur gears 152, 153, the locking pin 155, and the tension spring 156 constitute the antiphase torque generating member 130. In the third embodiment, the antiphase torque generating member 130 exists for each combination of a total of four sets of planting transmission cases 31 and row stop clutches 102. Even when configured as described above, the same effects as those of the second embodiment are achieved.

[0088] As is clear from the above embodiment and from Figures 19 and 20, the rice transplanter is equipped with a transmission case 11 that changes the speed of the power of the engine 10 mounted on the traveling body 1, a seedling planting device 2 having a transplanting mechanism 8 with planting claws 96 that draw a non-circular operating trajectory, a plant spacing transmission 26 that changes the operating speed of the transplanting mechanism 8 relative to the traveling speed of the traveling body 1 to change the plant spacing, and variable speed members 98, 99 that transmit variable speed rotational power to the transplanting mechanism 8. The rice transplanter further includes an anti-phase torque generating member 130 that adds an anti-phase torque Tan that is in the opposite phase to the rotational torque T of the transplanting mechanism 8 based on the variable speed rotational power. Therefore, the anti-phase torque Tan from the anti-phase torque generating member 130 cancels out the rotational torque T of the transplanting mechanism 8 due to the variable speed rotational power, and the load fluctuations (which may be called torque fluctuations) acting on the transplanting mechanism 8 are leveled out, ensuring smooth rotation of the transplanting mechanism 8. This prevents the occurrence of a phenomenon known as "shuttleball," allowing seedlings to be planted in the correct planting position.

[0089] In addition, when the row stop clutch 102 is in the power interruption state, the antiphase torque Tan is not generated, and there is no risk of unnecessary torque being transmitted to the periphery of the transplanting mechanism 8. Moreover, the row stop clutch 102 that connects and disconnects the power transmission from the inter-plant speed change device 26 to the transplanting mechanism 8 is provided in the front-rear long planting transmission case 31 of the seedling planting device 2, and the antiphase torque generating member 130 is disposed downstream of the row stop clutch 102 in the planting transmission case 31. This means that the antiphase torque generating member 130 is located in the vicinity of the transplanting mechanism 8, which is the source of the load fluctuation, and this has the effect of offsetting the rotational torque T of the transplanting mechanism 8 with the antiphase torque Tan, i.e., has a high effect of leveling out the load fluctuation.

[0090] (9) Fourth to ninth embodiments of the antiphase torque generating member Next, a fourth embodiment of the reverse phase torque generating member 130 will be described with reference to Figures 21 and 22. In the fourth embodiment, the reverse phase torque generating member 130 is applied to a structure in which the rotation of the planting drive shaft 32 is transmitted to the planting central shaft 91 by the chain 163. In this case, the driving sprocket 161 is rotatably supported on the planting drive shaft 32 in the planting transmission case 31, while the driven sprocket 162 is rotatably supported on the planting central shaft 91. A chain 163 for power transmission is wound around the driving sprocket 161 and the driven sprocket 162 in the planting transmission case 31. A torque limiter 164 is fitted to the planting drive shaft 32 so as to be slidable and non-rotatable relative to the driving sprocket 161. When a load of a predetermined value or more is applied to the planting drive shaft 32, the torque limiter 164 is disengaged and the power transmission from the planting drive shaft 32 to the driving sprocket 161 is interrupted. A row stop clutch 102, which connects and disconnects the power transmission from the driven sprocket 162 to the planting central shaft 91, is fitted onto the planting central shaft 91 so as to be slidable and non-rotatable relative to the driven sprocket 162. As shown in FIG. 22, the driving sprocket 161 and the driven sprocket 162 are configured as non-uniform speed sprockets having an elliptical shape or the like (non-circular). An idle roller 163' is abutted against the chain 163. This configuration imparts non-uniform rotation to the planting central shaft 91. In the fourth embodiment, the reduction ratio in the chain 163 transmission is an average of 1 / 2.

[0091] A power take-off shaft 165 extending parallel to the planting central shaft 91 is rotatably supported at the rear end side of the planting central shaft 91 in the planting transmission case 31. One end side (the right end side in this embodiment) of the power take-off shaft 165 protrudes outward to the left and right from the planting transmission case 31. A leveling main driving sprocket 166 is fixed to the planting central shaft 91 on the opposite side of the row stop clutch 102 across the driven sprocket 162, while a leveling driven sprocket 167 is fixed to the power take-off shaft 165. A chain 168 for power transmission is wound around the leveling main driving sprocket 166 and the leveling driven sprocket 167. The rotational power of the planting central shaft 91 is branched and transmitted to the power take-off shaft 165 via the sprocket and chain transmission system 166-168. When an optional device such as a chemical sprayer is attached to the seedling planting device 2, the rotational power of the power take-off shaft 165 is transmitted to the optional device.

[0092] The other end of the power take-off shaft 165 is bent into a crank shape. A tension spring 169 is mounted between the crank tip of the power take-off shaft 165 and the inner peripheral wall of the planting transmission case 31 as a means for generating an antiphase torque. The tension spring 169 constantly urges the crank tip of the power take-off shaft 165 to move downwardly to the center of rotation of the power take-off shaft 165. The tension spring 169 expands and contracts due to the rotation of the power take-off shaft 165 via the leveling driven sprocket 167. In the fourth embodiment, the power take-off shaft 165, the leveling driving and driven sprockets 166, 167, the chain 168, and the tension spring 169 constitute the antiphase torque generating member 130. That is, the power take-off shaft 165 is one of the components of the antiphase torque generating member 130. In the fourth embodiment, there is an opposite phase torque generating member 130 for each combination of a total of four planting transmission cases 31 and row stop clutches 102. Even when configured as described above, the same effects as those of the second and third embodiments are achieved.

[0093] In all of the fifth and subsequent embodiments shown in FIG. 23, the rotation of the planting drive shaft 32 is transmitted to the planting central shaft 91 by the chain 163, and the reverse phase torque generating member 130 is applied to the structure in which the rotation of the planting drive shaft 32 is transmitted to the planting central shaft 91 by the chain 163, as in the fourth embodiment. In the fifth embodiment, both the driving sprocket 161 on the planting drive shaft 32 and the driven sprocket 162 on the idle shaft 170 are circular but eccentric non-uniform speed sprockets. The driving gear 171 is fixed to the idle shaft 170, and the driven gear 172 is fixed to the planting central shaft 91. By meshing the driving gear 171 and the driven gear 172, the planting central shaft 91 is given a non-uniform speed rotation. The reduction ratio in the chain 163 transmission is 1 on average, but the reduction ratio in the gear transmission from the driving gear 171 to the driven gear 172 is 1 / 2. The chain 163 is abutted against an idle roller 163'. It is also possible to configure one of the sprockets 161, 162 to be eccentric and the other not to be eccentric.

[0094] The sixth embodiment shown in Fig. 24 and the seventh embodiment shown in Fig. 25 are modified versions of the fourth embodiment shown in Fig. 21 and Fig. 22. In the sixth embodiment shown in Fig. 24, the driving sprocket 161 provided on the planting drive shaft 32 is configured as a circular constant speed sprocket. In the seventh embodiment shown in Fig. 25, the driving sprocket 161 provided on the planting drive shaft 32 is configured as a circular but eccentric non-constant speed sprocket. In the sixth and seventh embodiments, the reduction ratio in the chain 163 transmission is 1 / 2 on average.

[0095] In the eighth embodiment shown in Figure 26, the driving sprocket 161 provided on the planting drive shaft 32 is configured as a circular but eccentric variable speed sprocket, and the driven sprocket 162 provided on the planting central shaft 91 is a circular constant speed sprocket. In this case, the reduction ratio in the chain 163 transmission is also 1 / 2 on average.

[0096] In the ninth embodiment shown in Figure 27, the driving sprocket 161 provided on the planting drive shaft 32 is configured as an elliptical (non-circular) variable speed sprocket, and the driven sprocket 162 provided on the planting central shaft 91 is configured as a polygonal (non-circular) variable speed sprocket. In this case, the reduction ratio in the chain 163 transmission is also 1 / 2 on average. Because the driven sprocket 162 is formed in a substantially square shape, acceleration and deceleration occur four times in one rotation of the planting central shaft 91.

[0097] As is clear from the above embodiment and from Figures 21 to 27, in a rice transplanter equipped with a transmission case 11 that changes the speed of the power of the engine 10 mounted on the traveling body 1, a seedling planting device 2 having a transplanting mechanism 8 with planting claws 96 that draw a non-circular operating trajectory, a spacing transmission 26 that changes the operating speed of the transplanting mechanism 8 relative to the traveling speed of the traveling body 1 to change the spacing between the seedlings, and variable speed members 161, 162 that transmit variable speed rotational power to the transplanting mechanism 8, an anti-phase torque Tan that is in the opposite phase to the rotational torque T of the transplanting mechanism 8 based on the variable speed rotational power is added. The seedling planting device 2 further comprises an anti-phase torque generating member 130 which generates an anti-phase torque to the seedling planting device 2, and a power take-off shaft 165 capable of transmitting power to an optional device attached to the seedling planting device 2 is provided in the front-to-rear long planting transmission case 31 of the seedling planting device 2, and the power take-off shaft 165 is a component of the anti-phase torque generating member 130.This smooths out the load fluctuations (torque fluctuations) acting on the transplanting mechanism 8 and ensures smooth rotation of the transplanting mechanism 8, while effectively utilizing the power take-off shaft 165 to also serve as the anti-phase torque generating member 130, thereby contributing to simplifying and reducing the weight of the power transmission structure to the seedling planting device 2.

[0098] (10) Other The present invention can be embodied in various ways other than the above-mentioned embodiment. For example, the inter-row transmission 26 can be built into the transmission case 11, and in this case, one upstream variable speed member is built into the transmission case 11. When a variable speed member is provided in each of the traveling body 1 and the seedling planting device 2, the acceleration / deceleration ratio (variable speed ratio) may be set as necessary. Therefore, in some cases, it is also possible to make the acceleration / deceleration ratio (variable speed ratio) on the traveling body 1 side smaller than the variable speed conversion ratio in the seedling planting device 2. A belt transmission (preferably a timing belt) may be used instead of the chain transmission. In any of the first to ninth embodiments, the crank structure part and the tension spring of the reverse phase torque generating member 130 can be disposed outside the planting transmission case 31. [Explanation of symbols]

[0099] 1 Running body 2 Seedling planting device 8 Transplant mechanism 10 Engine 11 Mission case 26 Interplant transmission 36 Rotary Case 37 Planting claw parts 40 Interplant Case 87 Planting transmission shaft 91 Planting center axis 96 Planting Claw 98 Downstream inconstant velocity active bevel gear 99 Downstream variable speed driven bevel gear 102 Row stop clutch 105 Operation Ring 130 Antiphase torque generating member 131 End Case 132 Planting Branch Axis 133 Leveling bevel gear 134 Eccentric shaft 136 Tension Spring 142 Outer teeth 143 Leveling Spur Gear 145,155 Locking pin 146,156,169 Tension spring 152 1st spur gear for leveling 153 2nd spur gear for leveling 161 Drive sprocket 162 Driven sprocket 163,168 Chen 164 Torque limiter 165 Power take-off shaft 166 Leveling drive sprocket 167 Leveling driven sprocket 169 Tension Spring

Claims

1. A seedling planting device supported on a traveling part; A plant spacing variable speed device that transmits power to the seedling planting device and can change the working speed of the seedling planting device relative to the running speed of the traveling section, The inter-plant transmission device includes an output shaft that transmits power to the seedling planting device, a first switching mechanism that can switch the power of the power transmission path to the output shaft in multiple stages, and a second switching mechanism that can switch the power of the power transmission path to the output shaft in multiple stages. The inter-plant transmission device is configured to be able to switch the power of the power transmission path to the output shaft to a plurality of gear stages by combining the power switched by the first switching mechanism and the power switched by the second switching mechanism, The plurality of gear stages include a plurality of uniform power gear stages and a plurality of non-uniform power gear stages, The rice transplanter, wherein only some of the multiple non-uniform speed power transmission gear stages are usable.

2. The rice transplanter according to claim 1 , wherein the remaining gear stages other than the part of the gear stages among the plurality of variable speed power gear stages are unavailable.

3. The rice transplanter according to claim 1 or 2, wherein the plurality of gear stages is greater than a predetermined number of gear stages that can be set during planting work of the seedling planting device.

4. The first switching mechanism includes: A plurality of transmission gears supported in parallel on the output shaft; A counter shaft provided parallel to the output shaft; a plurality of counter gears supported by the counter shaft and corresponding to the plurality of transmission gears, The second switching mechanism includes: an input shaft arranged concentrically with the output shaft; A plurality of gears fixed to the input shaft; The rice transplanter according to any one of claims 1 to 3, further comprising: a gear that is slidably fitted onto the counter shaft and meshes with any one of the plurality of gears.

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