JP2012196199A - Seedling transplanter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problem that torsion of a shaft caused by functioning an unequal speed conversion means in a rice transplanter having a rotary planting device.SOLUTION: The planting device 8 includes: a rotary case 36; and a pair of scraping units 37 mounted on the rotary case. A sun gear 92, an intermediate gear 93, and a planetary gear 94 are incorporated in the rotary case 36. The sun gear 94 is fixed to a planting center shaft 91. Power is transmitted from a planting transmission shaft 87 to a planting center shaft 91 through third bevel gears 98, 99. Half or more of the required acceleration or deceleration speed is given to a power transmission passage by an unequal speed gear incorporated in a spacing changing device in sparse planting. Half or less of the acceleration or deceleration speed in sparse planting is always given in the third bevel gears 98, 99. Acceleration or deceleration is performed at multiple locations, thus, oscillation is suppressed, and torsion deformation of the shaft is suppressed.

Description

  The present invention relates to a seedling transplanter such as a riding rice transplanter, and particularly has a feature in power transmission means for a planting device.

  Rice transplanter is a representative seedling transplanter. This rice transplanter generally has a traveling machine body on which an engine is mounted and a planting part arranged behind the traveling machine body, and the planting part is connected to the traveling machine body so as to be movable up and down. The planting part has a seedling platform on which a seedling mat is placed and a planting device arranged behind the seedling platform. The planting apparatus is generally of a type in which two scraping units are provided in one rotary case. When the rotary case rotates once, each of the two scraping units rotates once with respect to the rotary case. In other words, the scraping unit rotates while revolving around the axis of the rotary case, and the scraping unit moves up and down while changing its posture, so that the seedling can be scraped off and planted on the field. Done.

And how many seedlings are planted per unit area (generally 3.3 m ² ) is not always constant, and the desired number of strains varies depending on the region and user. Therefore, the number of planting strains per unit area can be changed by changing the operation speed of the planting device with respect to the traveling speed and changing the interval between the seedling stocks and the stock (between strains). Previously, there were many dense plantings of 60-90 strains per 3.3m ² , but the planting density and yield of seedlings were not proportional, and even if the planting density was low, there was no difference in yield or on the contrary it was seen that the revenue increased Therefore, in recent years, it can be said that sparse vegetation, for example, 37 to 50 strains per 3.3 m ² tended to increase.

  Now, the rotary planting device has a planting claw, and the planting claw scrapes off the seedling from the seedling mat in a slanted posture in a side view, and then the planting claw is in a nearly vertical posture. Then head to the field, start to descend and then start to rise. In other words, the planting claw is designed to move away from the field quickly, while drawing a closed loop trajectory and scraping the seedling, inserting the seedling into the field (mud), and leaving the field. It has been done.

  However, since the operation cycle of the planting device per unit mileage will inevitably change when the stock changes, set so that the planting claw is in a nearly vertical position near the bottom dead center, for example, when densely planted. If so, the speed at which the planting claws escape from the field becomes slow in the sparsely planted state, so that in the sparsely planted state, the planted nails tend to push down the planted nails forward. On the other hand, if the planting is set so that it is in the vertical position near the bottom dead center in the sparsely planted state, in the densely planted state, the phenomenon that the planting claws enter the field and go backwards will occur, and the mud will crawl This causes a problem that floating seedlings are easily generated.

  Therefore, in order to move the planting claw away from the field more quickly in the sparsely planted state with reference to the densely planted state, an inconstant speed gear is arranged in the power transmission path in the sparsely planted state (for example, Patent Documents 1 and 2.). That is, by providing an inconstant speed gear and changing the angular velocity during one rotation of the rotary case, the planting claws are quickly released from the field.

  In patent document 1, the stock change apparatus is arrange | positioned inside the driving | running | working mission case provided in the traveling body, and the inconstant speed gear is integrated in this stock change apparatus. On the other hand, in patent document 2, the inconstant speed gear is arrange | positioned in the site | part of the planting part in the downstream rather than the transverse feed mechanism of a seedling stand.

  Now, in a rotary type planting device, two planting claws are provided in the rotary case, and planting is performed twice by one rotation of the rotary case. Therefore, the seedlings are scraped one by one by horizontally feeding the seedling platform by one pitch each time the rotary case makes a half rotation. In addition, power is transmitted from the traveling machine body to the planting part through the PTO shaft. However, in Patent Document 1, since the inconstant speed gear is built in the mission case of the traveling machine body, the PTO shaft rotates at an inconstant speed. Accordingly, the transverse feed shaft also rotates at a non-uniform speed. On the other hand, in Patent Document 2, an inconstant speed gear is disposed on the downstream side of the lateral feed mechanism section in consideration of the adverse effect of the infinite speed rotation of the lateral feed shaft.

Japanese Patent No. 4376154 JP 2003-189712 A

  Now, the power transmission path from the inter-plant change device to the planting claw is composed of transmission elements such as gears and rotating shafts, but the transmitting elements such as the rotating shafts are not perfect rigid bodies, and load (rotational torque) is applied. When the load is released, the elastic deformation force returns and deforms. That is, in the power transmission system, torsion and untwisting are alternately generated by the rotation, and this appears as vibration. And if a rotating shaft etc. twist, the operation timing of a planting claw will shift | deviate and there exists a possibility that a planting defect may generate | occur | produce.

  The non-constant speed gear accelerates and decelerates the angular velocity during one rotation of the rotating shaft, and the load fluctuation acting on the rotating shaft increases by accelerating and decelerating the rotation. If this is done, the torsion of the power transmission system will be noticeable. For example, when the vibration caused by the load fluctuation matches the natural frequency of the transmission element constituting the power transmission path, a resonance phenomenon occurs, and the timing difference of the planting claw appears more remarkably. Durability is also reduced. Further, when the planting speed is increased, the torque fluctuation increases, and the shaft twist and phase shift also increase, and planting defects are likely to occur. Furthermore, if the power transmission path rotates largely at a non-uniform speed as a whole, backlash is likely to occur at the connecting portion between the members, and this backlash accumulates and a planting phase shift may occur.

  The present invention has been made in view of such a current situation, and in providing an inconstant speed conversion means such as an inconstant speed gear, it is intended to prevent problems while enjoying the merits thereof. In addition, the present application discloses unprecedented inventions related to the inconstant speed conversion means, and it can be grasped as an object to provide these inventions.

  The inventor of the present application includes various configurations. The invention of claim 1 constitutes a superordinate concept. A seedling transplanting machine according to the present invention includes a planting device that repeats scraping and planting transplanting operations while traveling in a field, and a power source that drives the planting device. And a strain change device that changes the relationship between the traveling speed of the planting apparatus and the transplanting operation speed in the power transmission path from the power source to the planting apparatus, and the power transmission path is configured And an inconstant speed converting means for applying inconstant speed rotation to the rotating shaft. The inconstant speed converting means is provided at a plurality of locations in the power transmission path.

  The invention of claim 2 is a preferred development of the invention of claim 1, and in this invention, a traveling machine body on which an engine as the power source is mounted, and a planting portion disposed behind or in front of the traveling machine body are provided. In the configuration in which the planting device is attached to the planting unit, the inconstant speed conversion means is provided separately for the traveling machine body and the planting unit.

  The invention of claim 3 embodies the invention of claim 2, and in this invention, the unequality of the unequal speed conversion means in the planting part is greater than the unequal speed ratio of the unequal speed conversion means in the traveling body. The speed ratio is set small. According to a fourth aspect of the present invention, as a suitable development example of the second or third aspect, the inconstant speed conversion means of the planting portion is provided at the end of the power transmission path.

  As a transmission element constituting the power transmission path, there are various elements such as a gear, a rotating shaft, a clutch, a sprocket, and a chain. There are various gears such as a bevel gear and a planetary gear as well as a flat gear. Conventionally, a flat gear is configured as an inconstant speed gear as the inconstant speed conversion means. On the other hand, in the invention of claim 5, the bevel gear is an inconstant speed gear. That is, according to a fourth aspect of the present invention, the power transmission path has rotating shafts intersecting each other, and the bevel gear is configured to transmit power to these intersecting rotating shafts, and the bevel gear is an inconstant speed gear.

  The invention of claim 6 is the invention according to claim 2 or 3, wherein the power from the traveling machine body is input to the planting part by a PTO shaft extending substantially in the front-rear direction in plan view, and the rotation of the PTO shaft is The rotation of the planting drive shaft that is horizontally long through the first bevel gear pair is converted into the rotation of the planting drive shaft that is longitudinally longitudinal through the second bevel gear pair, and the planting The rotation of the transmission shaft is converted into the rotation of a laterally long planting central shaft through a third bevel gear pair, and the rotary planting device is attached to the planting central shaft, and the third bevel gear The pair is an inconstant gear.

  The invention according to claim 7 is the invention according to claim 2 or 3, wherein the non-uniform speed conversion means in the traveling machine body is provided with a switching means between non-uniform speed rotation and constant speed rotation, and rotates at non-uniform speed in a sparse planting state. On the other hand, the unequal speed conversion means in the planting part is always set to rotate at an unequal speed.

  An inconstant speed gear is arranged inside the rotary case constituting the rotary planting device, which is for giving a long trajectory up and down to the planting claw. This is different from the constant speed conversion means (that is, means for imparting inconstant speed rotation (acceleration / deceleration) to the members constituting the power transmission path).

  As described above, when a power transmission system composed of a group of power transmission elements rotates at unequal speed, the load fluctuation becomes larger than that at constant speed rotation. In this case, since the inconstant speed conversion means is arranged at only one place, a load acts intensively on a member having a low strength among the elements constituting the power transmission system, and therefore the amount of torsional deformation increases. Guessed. On the other hand, in the present invention, since the inconstant speed conversion means is provided dispersedly at a plurality of locations in the power transmission path, it is possible to suppress a load from being concentrated on a specific power transmission element. As a result, planting defects can be prevented or suppressed.

  In addition, in the present invention, since the portion that rotates largely at a non-uniform speed can be reduced as compared with the prior art, it is possible to suppress the occurrence of play in the power transmission path, and as a result, the planting phase shifts due to play in the power transmission path. Can be prevented or suppressed. As described above, in general, it is necessary to rotate the power transmission system at unequal speed in a sparsely planted state. Therefore, it is preferable to set so as to rotate at a non-uniform speed in conjunction with switching between the strain change devices to the sparse planting state.

  On the other hand, in the case of a seedling transplanter having a traveling machine body and a planting device, it is theoretically possible to provide an inter-plant change device in the planting unit, but it is a good idea to make the planting unit as light as possible. It is preferable that the inter-stock change device is provided on the traveling machine body. Also, in recent seedling transplanters (rice transplanters), a fertilizer is often installed on the traveling machine, but the fertilizer must be linked to the movement of the planting device. It is provided in the machine body, and power is transmitted from the inter-strain change device to the fertilizer and the planting unit. In any case, it is preferable that the stock change apparatus is provided on the traveling machine body.

  Then, as in the invention of claim 2 of the present application, when one non-uniform speed conversion means is provided in the inter-cell change device of the traveling machine body and the other one is provided in the planting part, the planting is linked to the operation of the inter-cell change device. While maintaining the function of imparting a large unequal speed rotation to the attaching device, it is possible to suppress twisting during the unequal speed rotation. In addition, when the unequal speed conversion means is provided in the planting part as in claim 2, the unequal speed conversion means of the planting part can always function, and is switched between a functioning state and a non-functioning state. It is also possible.

  When the unequal speed conversion means is arranged separately in the traveling machine body and the planting part as in claim 2, the rotational fluctuation ratio of the unequal speed conversion means in the traveling machine body and the rotational fluctuation of the unequal speed conversion means in the planting part. Although the ratio can be set arbitrarily, the strength of the members constituting the power transmission path is often reduced as the planting device is approached. It is possible to prevent an excessive load from being applied to the member due to a load variation due to constant speed rotation.

  Moreover, when the structure of Claim 3 is employ | adopted, there also exists an advantage by which a bad influence does not generate | occur | produce even if a planting apparatus is rotated at a nonuniform speed in a dense planting state. That is, it is possible to deal with sparse planting and dense planting simply by switching between a functioning state and a non-functioning state of the inconstant speed conversion means provided in the traveling machine body, and therefore, it is possible to avoid complication of the switching structure. In rice transplanters, in general, the planting device is given acceleration / deceleration of, for example, about 10 to 40 by the non-uniform speed conversion means in the sparse planting state. It was preferable to set the variation ratio of the means to be slightly large and the variation ratio of the non-uniform speed conversion means in the planting part to be slightly small.

  Now, since the scraping unit is attached to both ends of the long and narrow rotary case, the rotary type planting device has an inherently unbalanced structure, and when the seedling is scraped, the torque reaches its peak, and then Torque is almost lost. For this reason, there is a characteristic that the torque fluctuation is large and the resonance becomes easier as the speed becomes higher. However, in the present invention, by applying slight acceleration / deceleration to the planting device at all times, torque variation of the planting device can be suppressed and smooth high-speed operation can be achieved.

  Since the non-uniform speed conversion means is for rotating the planting device at non-uniform speed, if it is provided at the end of the power transmission path as in claim 4, the planting device can accurately rotate at a non-uniform speed. This is preferable. That is, it is preferable because it is possible to prevent or significantly suppress the accumulation of bending in the middle of the power transmission path.

  As described above, in the past, the spur gear was replaced with the inconstant speed gear as the inconstant speed converting means, but this may complicate the structure. On the other hand, if the bevel gear is an inconstant speed gear as in claim 5, the bevel gear for transmitting the power to the rotating shaft with the intersecting posture can be used as it is for the inconstant speed converting means, thus simplifying the structure. be able to.

  The invention of claim 6 is a specific example in which claims 4 and 5 are combined, and an inconstant speed rotation is imparted to the rotary type planting device without complicating the structure. For this reason, it is excellent in adaptability to an actual seedling transplanter such as a rice transplanter. In addition, when the 1st-3rd bevel gear is arrange | positioned at the planting part like Claim 6, it is also possible to make a 1st bevel gear or a 2nd bevel gear with an inconstant speed gear.

  If it comprises like Claim 7, since the burden (torque fluctuation | variation) of the axis | shaft which comprises a power transmission mechanism can be reduced, the twist of an axis | shaft can be prevented or suppressed and it is suitable. In this case, since the degree of acceleration / deceleration at the planting part is small, there is no adverse effect even if the acceleration / deceleration is performed even in the densely planted state.

It is a top view of the rice transplanter concerning an embodiment. It is a side view of a rice transplanter. It is a perspective view which shows the framework of a rice transplanter. (A) is a perspective view which shows the whole power transmission path | route, (B) is a perspective view of a planting apparatus. (A) is a side view of a power transmission path, (B) is a side view of a location of a planting device, and (C) is a diagram showing a locus of a planting claw. (A) is a top view which shows a power transmission path | route, (B) is an external appearance perspective view of a stock change apparatus, (C) and (D) are external appearance perspective views of the center case provided in the planting part. (A) is an external perspective view of the gear group in the stock change device and the center case, (B) is a perspective view of the gear group in the center case, and (C) is a rear view of the gear group in the center case. It is a transmission system diagram. (A) is a top view which shows the power transmission path | route to a planting apparatus, (B) is the isolation | separation top view of the terminal planting part of a power transmission path | route, (C) is the schematic of a bevel gear. (A) And (B) is a top view which shows the meshing state of a bevel gear, (C) (D) is a perspective view of a bevel gear, (E) is a contrast figure which arranged the pair of bevel gears. It is a principal part top view of 2nd Embodiment. It is a principal part isolation | separation top view of 2nd Embodiment. (A) is a sectional view taken along line XIIIA-XIIIA in FIG. 12, (B) is a sectional view taken along line BB in (A), (C) is a sectional view taken along line CC in (A), and (D) is another example. FIG. It is a figure which shows 3rd Embodiment, (A) is a principal part side view, (B) is a BB view of (A), (C) is a partially broken isolation | separation side surface which shows a switching means. It is a figure which shows 4th Embodiment, (A) is a sectional side view, (B) is a schematic diagram. It is a side view which shows 5th Embodiment. It is a figure which shows 6th Embodiment, (A) is sectional drawing, (B) is BB sectional drawing of (A). It is a side view which shows 7th Embodiment. It is a side view which shows 8th Embodiment. It is a side view which shows 9th Embodiment. It is a side view which shows 10th Embodiment. It is a side view which shows 11th Embodiment.

  Next, embodiments of the present invention will be described with reference to the drawings. This embodiment is applied to a riding type rice transplanter (hereinafter simply referred to as “rice transplanter”). In the following description, the front / rear / left / right wording is used to specify the direction, but the front / rear / left / right wording defines the forward direction of the rice transplanter as the front. The front view direction is opposite to the forward direction.

(1). Outline of rice transplanter First, the outline of the rice transplanter will be described with reference to FIGS. As shown in FIGS. 1-3, the rice transplanter has the traveling body 1 and the planting part 2 arrange | positioned behind it. The traveling machine body 1 includes front and rear wheels 3 and 4, a control seat 5, and a control handle 6, while the planting unit 2 includes a seedling platform 7 and a planting device 8 on which a seedling mat is placed. The rice transplanter of the present embodiment is an eight-row planting type. For this reason, eight seedling mat placement areas are formed on the seedling placing stand 7, and eight planting devices are provided at the rear of the planting portion 2. 8 are arranged in a horizontal row.

  As shown in FIG. 3, the traveling machine body 1 has a frame 9 made of a large number of frame members, and an engine 10 is supported by the front portion of the frame 9. A traveling mission case 11 is disposed behind the engine 10. As clearly shown in FIG. 4A, a hydrostatic continuously variable transmission (HST) 12 is mounted on the left side surface of the mission case 11, and the power of the engine 10 is hydrostatically continuously variable by a belt 13. Is transmitted to the machine (HST) 12. The engine 10 is covered with a hood 14. Further, a portion of the traveling machine body 1 excluding the hood 14 is covered with a vehicle body cover 15.

  A front axle device 17 is attached to the left and right side surfaces of the mission case 11, and the front wheel 3 is attached to the front axle device 17. A rear axle case 18 is disposed behind the transmission case 11, and the rear wheel 4 is attached to a rear axle that protrudes laterally from the rear axle case 18. The transmission case 11 and the rear axle case 18 are connected to each other by a longitudinal joint material 19. Two rear struts 20 are attached to the rear axle case 18, and the upper end of the rear strut 20 is fixed to a laterally long rear frame 9 a that forms the rear end of the skeleton 9.

  A link device 21 composed of upper and lower link bodies (top link and lower link) is rotatably connected to the left and right rear columns 20, and the planting portion 2 is attached to the rear end of the link device 21. The link device 21 can be rotated by a hydraulic cylinder (elevating cylinder) 22 connected to the joint material 19. Therefore, the planting part 2 moves up and down by extending and contracting the hydraulic cylinder 22.

  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 by the rear wheel drive shaft 23. The rotation of the rear wheel drive shaft 23 is transmitted to the rear wheel 4 through a gear group provided on the rear axle case 18. The rice transplanter of this embodiment is provided with a leveling rotor 24 in the planting part 2, and power is transmitted to the leveling rotor 24 from 25 by a rotor drive shaft that protrudes backward from the rear axle case 18.

  In the present embodiment, a stock change device 26 is attached to the right side portion of the rear axle case 18, and power is transmitted from the transmission case 11 to the stock change device 26 through a planting power transmission shaft 27. The rotation of the planting power transmission shaft 27 is changed by a gear group built in the inter- stock changer 26 and transmitted to the planting unit 2 by the PTO shaft 29.

  The planting part 2 has a horizontally long main frame 28, and a center case 30 is fixed to a substantially right and left intermediate part of the main frame 28. The power of the PTO shaft 29 is transmitted to a gear group built in the center case 30. Communicated. Four support arms 31 extending rearward are fixed to the rear surface of the main frame 28, and a pair of right and left planting devices 8 are rotatably attached to the rear end portion of the support arm 31.

  A laterally long planting drive shaft 32 passes through a base end portion (front end portion portion) of the support arm 31, and the planting device 8 is driven by the rotation of the planting drive shaft 32 (details will be described later). . Further, power is transmitted to the planting drive shaft 32 from the PTO shaft 29 via a gear group built in the center case 30. The center case 30 is also provided with a laterally long lateral feed shaft 33, and the seedling stage 7 moves laterally by one pitch by the rotation of the lateral feed shaft 33.

  The planting part 2 has a group of belts 34 on which seedling mats are placed. The belts 34 are wound around a pair of upper and lower vertical feed shafts 35. When the seedling placing table 7 has completely moved to either the left or right, the vertical feed support shaft 35 rotates, and the seedling mat moves downward by one pitch.

  As shown in FIG. 4 (B), each planting device 8 has one rotary case 36 and a scraping unit 37 that is rotatably provided at both ends thereof, and the rotary case 36 makes a half turn. Each time, the scraping unit 37 is scraped and planted. Further, the rotary case 36 is set to rotate 1/2 when the PTO shaft 29 rotates once. The rotational speed of the PTO shaft 29 is proportional to the traveling speed of the rice transplanter. By changing the relationship between the traveling speed and the rotational speed of the PTO shaft 29 by the inter- stock changer 26, the seedling planting interval (between stocks) Can be changed.

(2). Structure of the inter-strain changing device Details of the power transmission path from the inter-strain changing device 26 to the planting device 8 will be described below. First, the details of the inter- stock change apparatus 26 will be described mainly based on FIGS. The stock change apparatus 26 has a front / back split stock case 40 shown in FIG. 4 (B), and a gear group shown in FIGS. 6 (A) and 6 (C) is arranged therein. .

  An input shaft 41 and an output shaft 42 are disposed inside the stock 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 having the same diameter are fixed to the input shaft 41. Although both gears 43 and 44 have the same diameter, the number of teeth of the second gear 44 is slightly smaller than that of the first gear 43.

  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 relatively rotatable, and the intermediate shaft 45 is fitted in a state of rotating together with the output shaft 42 (a state in which relative rotation is impossible). A third gear 46 and a fourth gear 47 are slidably fitted to the intermediate shaft 45 by spline fitting or the like so as not to be relatively rotatable. Further, a first inconstant speed gear 48 is fitted on the intermediate shaft 45 so as to be freely rotatable and slidable.

  A cam-type main clutch 49 is provided on the output shaft 42. The main clutch 49 includes a fixed part 49a and a slide part 49b. The slide part 49b is urged toward the fixed part 49a by a clutch spring 49c (see FIG. 7C). When the slide part 49b moves away from the fixed part 49a against the clutch spring 49c, power transmission from the input shaft 41 to the output shaft 42 is cut off. The main clutch 49 is disengaged in the state where the planting part 2 is raised as when traveling on the road or turning. The disengagement operation of the main clutch 49 is performed by lowering the main clutch operation shaft 50.

  An idle shaft 51 extending in parallel with the input shaft 41 and the output shaft 42 in a side view is rotatably supported inside the inter-case case 40, and the first gear 43 or the second gear 44 is supported on the idle shaft 51. The fifth gear 52 that can mesh with each other is fitted so as to be slidable and relatively non-rotatable by spline fitting or the like. The fifth gear 52 has about twice as many teeth as the first gear 43 or the second gear 44, and a first position meshed with the first gear 43 and a second position meshed with the second gear 44 can be selected. .

  Instead of selectively meshing the fifth gear 52 with the first gear 43 or the second gear 44, in addition to the fifth gear 52 for deceleration meshing with the first gear 43, FIG. It is also possible to employ a configuration in which a reduction gear 53 that meshes with the second gear 44 is provided and power is transmitted to either of the reduction gears 52, 53.

  Regarding the relationship between the number of teeth of the first gear 43, the second gear 44, and the fifth gear 52, for example, the number of teeth of the fifth gear 52 with respect to the first gear 43 is set to 2.0 times the ratio. The ratio of the number of teeth of the fifth gear 52 to can be set to about 2.3 times.

  The idle shaft 51 always meshes with the sixth gear 54 that meshes with and separates from the third gear 46, the seventh gear 55 that meshes with and separates from the fourth gear 47, and the first inconstant speed gear 48. The second inconstant speed gear 56 is fixed. 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. Accordingly, the rotational speed of the intermediate shaft 45 (and the output shaft 42) is higher in the state in which the fourth gear 47 and the seventh gear 55 are engaged than in the state in which the third gear 46 and the sixth gear 54 are engaged. Is lower. As a specific ratio of the number of teeth, for example, the ratio of the number of teeth of the sixth gear 54 to the third gear 46 is about 1: 1.94, and the ratio of the number of teeth of the seventh gear 55 to the fourth gear 47 is about 1: 1.41.

  The first inconstant speed gear 48 and the second inconstant speed gear 56 are non-circular profiles such as ellipses, and the number of teeth is set to be the same. Therefore, in a state where the rotation of the idle shaft 51 is transmitted to the intermediate shaft 45 and the output shaft 42 through the inconstant speed gears 48 and 56, the rotational speeds of the idle shaft 51 and the output shaft 42 are the same, and The output shaft 42 rotates in a state where the angular velocity is periodically changed during one rotation. The two inconstant speed gears 48 and 56 are non-circular and are always kept in an engaged state due to the particularity that the engaging posture is fixed.

For example, when the planting claw 96 is near the bottom dead center at the time of sparse planting of 37 strains / m ² , acceleration / deceleration is given to the rotary case 36 so that the movement is accelerated. Slightly larger acceleration / deceleration is imparted to the inter-stock case 40 by the non-constant speed gears 48 and 56 provided in FIG.

  The fourth gear 47 and the first inconstant speed gear 48 are provided with an intermediate clutch 57 that can be engaged and separated. When the fourth gear 47 is further slid rightward from the state shown in FIG. 8 after being engaged with the seventh gear 55, the intermediate clutch 57 is engaged. In a state where the intermediate clutch 57 is engaged, the power of the idle shaft 51 is transmitted to the output shaft 42 via the inconstant speed gears 56 and 48. In a state where the intermediate clutch 57 is engaged, the third gear 46 and the fourth gear 47 are idling. Accordingly, the intermediate clutch 57 serves to disconnect the connection between the intermediate shaft 45 and the first inconstant speed gear 48.

  When the fifth gear 52 slides, switching in two stages is performed, and when the intermediate shaft 45 slides, switching in three stages is performed. Therefore, there are six combinations as a whole. For example, the number of shares per 3.3 square meters can be changed to 37, 43, 50, 60, 70, 85, etc., covering almost all areas of sparse and dense planting. .

  A fertilizer rotation shaft 58 extending in parallel with the input shaft 41 and the output shaft 42 is rotatably disposed on the upper part of the inter-case case 40, and the fertilizer rotation shaft 58 is engaged with the first gear 43. A gear 59 is fitted so as to be relatively rotatable. Power is transmitted from the fertilizer rotating shaft 58 to the fertilizer driving shaft 62 via the bevel gear 61.

  As shown in FIG. 7A, the stock change apparatus 26 has two operation shafts, a first operation shaft 63 and a second operation shaft 64. These operation shafts 63 and 64 have a longitudinal and longitudinal posture, and are exposed in front of the inter-case case 40. As can be understood from FIG. 6B, the first operation shaft 63 can be slid back and forth with the first lever 65, and the second operation shaft 64 can be slid back and forth with the second lever 66. The first operation 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 includes a shifter that engages with the intermediate shaft 45.

(3). Internal Structure of Center Case Next, the internal structure of the center case 30 (that is, the planting part transmission) will be described with reference to FIGS. The center case 30 is formed of a left and right split type shell body, and a longitudinal input shaft 69 is rotatably held. The front end of the input shaft 69 and the rear end of the PTO shaft 29 are connected via a universal joint.

  A left and right longitudinal 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 71. Inside the center case 30, a lateral feed drive shaft 72 is disposed in a horizontally long posture, and the lateral feed shaft 33 is connected to the lateral feed drive shaft 72.

  Three scraping amount adjustment driven gears 73 are fixed to the lateral feed drive shaft 72, while three scraping amount adjustment main driving gears corresponding to the scraping amount adjustment driven gear 73 are fixed to the intermediate shaft 70. 74 is loosely fitted. Power is selectively transmitted from the intermediate shaft 70 to only one of the three scraping amount adjusting main driving gears 74 by the slide key 76 (see FIG. 8). The slide key 76 is slid by a slide lever 77 shown in FIGS.

  The ratio of the number of teeth of the pair of scraping amount adjusting gears 73 and 74 is different, and when the combination of the scraping amount adjusting gears 73 and 74 is changed, the rotation ratio of the transverse feed drive shaft 72 to the PTO shaft 29 is changed. . As a result, the lateral feed pitch of the seedling stage 7 changes, and the amount of seedling scraping changes.

  The center case 30 has an overhang 30a extending rearward and downward, and a horizontally long planting output shaft 78 is rotatably held by the overhang 30a. The planting output shaft 78 is fixed to an intermediate shaft 70. 1 relay gear 79, a second relay gear 80 fitted to the transverse feed drive shaft 72 so as to be relatively rotatable, a third relay gear 82 held by the center case 30 via an idle shaft 81, and a fourth relay gear. Power is transmitted through 84. The fourth relay gear 84 is attached to the planting output shaft 78 via the sleeve 83.

  The ratio of the number of teeth of the two gears constituting the pair of the first bevel gear 71 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 relationship. Therefore, the rotational speed between the PTO shaft 29 and the planting output shaft 78 has a 1: 1 relationship. Since the third relay gear 82 is a simple idle gear, the number of teeth does not affect the rotational speed of the fourth relay gear 84.

  The planting output shaft 78 and the planting drive shaft 32 located adjacent to the planting output shaft 78 are connected by a coupling (sleeve) 86. A relay shaft 78 ′ is disposed between the planting drive shafts 32 adjacent to the left and right, and the drive shaft 32 and the relay shaft 78 ′ are also connected by a coupling 86. Therefore, each planting drive shaft 32 rotates integrally. The planting drive shaft 32 is divided for each planting device 8, and adjacent planting drive shafts 32 are connected by a coupling 86. The planting output shaft 78, each planting drive shaft 32, and the relay shaft 78 'can be formed as a single structure made of a single bar.

  It is also possible to make the coupling 86 have a damper function (flywheel function) by configuring the coupling 86 to have a certain amount of mass as indicated by reference numeral 86 ′ at the lower end of FIG. 6A. . In this case, it is also possible to cancel the rotational fluctuation of the planting device 8 by making the coupling 86 an eccentric configuration in which the center of gravity is shifted from the planting device 8. The damper means may be provided on another rotating member constituting the power transmission path.

(4). Structure / Power Transmission Structure of Planting Device According to First Embodiment Next, the structure of the planting device 8 and the power transmission structure corresponding thereto will be described. These are the main parts of the first embodiment, and are mainly displayed in FIGS. 8 to 10 (see also FIG. 6A). The support arm 31 has a hollow structure, and as shown in FIG. 8, a longitudinally-planted transmission shaft 87 is rotatably held therein.

  Power is transmitted to the planting transmission shaft 87 from the planting drive shaft 32 by a pair of second bevel gears 88a and 88b. Of the second bevel gears 88 a and 88 b, the bevel gear 88 b 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. When a predetermined load or more is applied to the planting transmission shaft 87, the torque limiter 89 is disengaged and the power transmission is interrupted.

  A horizontally long planting center shaft 91 is rotatably held at the rear end portion (tip portion) of the support arm 31 via a pair of left and right bearings 104. The planting center shaft 91 projects to the left and right outside of the support arm 31, and a sun gear 92 built in the rotary case 36 is fixed to the projecting end portion. Although details are omitted, the rotary case 36 is rotatably held at the rear end portion of the support arm 31.

  The rotary case 36 has a hollow structure in which two left and right shell bodies are overlapped. The sun gear 92 described above is disposed in the longitudinal middle portion thereof, the intermediate gear 93 is disposed outside thereof, and the planetary gear is disposed outside thereof. A gear 94 is arranged. Each gear 92, 93, 94 is non-circular and eccentric. The scraping unit 37 is fixed to the unit shaft 95 fixed to the planetary gear 94.

  As shown in FIG. 5, the scraping unit 37 includes a planting claw 96 and a protruding rod 97, and as shown in FIG. The seedlings are planted in the field by cutting out and shifting to the field, and the protruding rod 97 moves forward relative to the planting claws 96 near the bottom dead center.

  As shown in FIG. 9, power is transmitted from the planting transmission shaft 87 to the planting central shaft 91 by a pair of third inconstant speed bevel gears 98 and 99. That is, a third inconstant speed driven bevel gear 98 is fixed to the planting transmission shaft 87 via the coupling 100, while a third inconstant speed driven bevel gear 99 is fitted to the planting center shaft 91. Uneven speed rotation is always transmitted from the planting transmission shaft 87 to the planting center shaft 91 by the pair of unequal velocity bevel gears 98 and 99.

  The third inconstant speed main drive bevel gear 98 has a stepped boss body 98a, and the coupling 100 is fitted in a small diameter portion of the boss body 98a. A bearing 101 is fitted in the boss body 98a. The coupling 100 is held on the planting transmission shaft 87 and the boss body 98a so as not to rotate relative to each other by key engagement or pinning. The third inconstant speed driven bevel gear 99 is fitted to the planting center shaft 91 so as to be relatively rotatable, and the third inconstant speed driven bevel gear 99 has a cam portion 103 that meshes with the movable clutch 102. An operation ring 105 is integrally welded to the movable clutch 102.

  The movable clutch 102 is slidable on the planting center shaft 91 and is held so as not to be relatively rotatable. The movable clutch 102 is normally pushed by a spring 106 so as to mesh with the third inconstant speed driven bevel gear 99. When a rotary operation rod (not shown) is operated, the movable clutch 102 is centered on the planting center shaft 91. Then, the power to the planting center shaft 91 is cut off.

  For example, in the planting operation at the shore, there is a case where it is not desired to operate some of the four pairs of planting devices 8. In such a case, the movable clutch 102 is operated to operate some planting devices 8. Can be stopped. In other words, the streaking function to reduce the number of planting streaks is exhibited.

(5). Unequal speed conversion means In the present embodiment, the third inconstant speed bevel gears 98 and 99 hold the inconstant speed conversion function. This point will be described mainly with reference to FIGS. 10 and 9C. As shown in FIG. 10 (E), when a large number of teeth 107 are formed on the third inconstant speed main driving bevel gear 98, the distance from the tip of each tooth 107 to the axis O1 is gradually increased and narrowed again. It is set. That is, each tooth 107 has a pitch cone angle minimum portion 108 with the shortest distance from the axis O1 to the tip, and a pitch cone angle maximum portion 109 with the widest distance from the axis O1 to the tip. The distance between them is gradually changing.

  In other words, as shown in FIG. 9C, the pitch circle 109 of each tooth 107 has a shape close to an ellipse and is eccentric with respect to a perfect circle (109 ′ indicates the pitch circle in the case of a true circle) Yes.) In other words, in the normal bevel gear, the outer peripheral surface of the virtual spindle is inclined at the same angle with respect to the axis at any part. However, in the main bevel gear 98 of the present embodiment, the virtual spindle The inclination angle θ1 (see FIG. 10A) of the outer peripheral surface gradually changes as it moves in the circumferential direction.

  The third inconstant speed driven bevel gear 99 has teeth 112 that is twice the number of teeth of the third inconstant speed driven bevel gear 98. And the position of the axial direction of each tooth | gear 112 has shifted | deviated little by little so that it can grasp | ascertain clearly from FIG. 10 (A) (B). In other words, the angle θ2 of the cone constituting the bevel gear changes little by little as it moves in the circumferential direction.

  Since the third inconstant speed driven bevel gear 99 has twice the number of teeth of the third inconstant speed bevel gear 98, the third inconstant speed bevel gear 98 has two pitch cone angle maximum portions 113 and pitches. It has a cone angle minimum portion 114. Accordingly, as shown in FIG. 9C, the pitch circle 115 of the third invariant driven bevel gear 99 has a substantially elliptical shape, and is symmetric with respect to the axis O2 (FIG. 9 ( In C), the pitch circle in the case of a perfect circle is indicated by reference numeral 115 '.)

(6) Summary of First Embodiment FIG. 5C shows the relationship between the number of planted stocks per 3.3 square meters and the movement trajectory of the planting claws 96. As can be seen from this figure, in the dense planting state, the planting claw 96 rises directly above the bottom dead center, but in the sparse planting state, the planting claw 96 escapes badly and the seedling is pushed down. Can understand.

  And in this embodiment, by providing the inconstant speed gears 48 and 56 in the stock change apparatus 26 and forming the third inconstant speed bevel gears 98 and 99 of the support arm 31 as inconstant speed gears, The rotary case 36 is accelerated so that the rotational speed increases when the planting claw 96 is located near the bottom dead center. For this reason, the planting claw 96 quickly escapes from the bottom dead center, and as a result, the phenomenon of pushing down the seedling with the planting claw 96 can be prevented.

  In the present embodiment, the inconstant speed gear that is the inconstant speed converting means is arranged separately between the stock change device 26 and the rear end of the support arm 31, so that the third inconstant speed bevel gear 98 is changed from the stock change device 26. , 99, the ratio of non-uniform rotation is smaller than in the prior art. As a result, the members constituting the power transmission path (PTO shaft 29, planting drive shaft 32, planting transmission shaft 87, etc.) The bending which generate | occur | produces can be suppressed remarkably and the smooth motion of the planting apparatus 8 can be ensured. Moreover, since the play which generate | occur | produces in a power transmission path | route can also be suppressed, the malfunction that the operation | movement phase of the scraping unit 37 shift | deviates and the position of planting shifts can also be prevented.

  Now, since the planting device 8 has a configuration in which the scraping unit 37 is swingably attached to both ends of the elongated rotary case 36, the scraping unit 37 serves as a weight and generates a large inertia force. Moreover, a large load is generated when the seedling mat is scraped off, and thereafter a negative load is generated. That is, due to the swinging of the scraping unit 37, a large torque fluctuation occurs in a cycle of overload-no load-negative load with respect to the rotation of the planting device 8. This torque fluctuation appears remarkably when the resonance rotational speed is exceeded even when rotating at a constant speed in the dense planting state (in the dense planting state, the planting device 8 rotates at a higher speed than in the sparse planting state). ).

  More specifically, even if the planting device 8 rotates at a constant speed, when one scraping unit 37 escapes from the field, the other scraping unit 37 has shifted to scraping of seedlings, and therefore two scraping units. It can be said that the scraping unit 37 acts to counteract the load fluctuations of each other, but since a large torque is required for scraping off the seedlings, the torque fluctuations are leveled only by the movement of the two scraping units 37. The function is weak. For this reason, the planting apparatus 8 does not rotate smoothly, and a phenomenon called “sucking” easily occurs.

  In this regard, when the planting apparatus 8 is slightly rotated at a non-uniform speed by the third non-uniform speed bevel gears 98 and 99 even in the dense planting state as in this embodiment, the scraping of the seedling by the scraping unit 37 exerts an inertial force. It is performed in a state where acceleration is applied while being used, and after the seedling is scraped off, the planting device 8 is decelerated, so that a large inertial force can be prevented from acting on the planting device 8, For this reason, load fluctuations (or torque fluctuations) acting on the planting device 8 can be leveled to ensure smooth rotation.

(7) Second Embodiment Next, a second embodiment shown in FIGS. 11 to 13 will be described. This embodiment is based on the first embodiment, and can be switched between a state where the inconstant speed rotation by the third inconstant speed bevel gears 98 and 99 functions and a state where it does not function. That is, in this embodiment, the support arm 31 is provided so that the non-constant speed rotating means and the constant speed rotating means can be switched.

  In the second embodiment, the third inconstant speed driven bevel gear 99 is integrally provided with a third constant speed driven gear 117 having a larger diameter. On the other hand, the third inconstant speed main drive bevel gear 98 is formed on the tip shaft 118 fitted to the planting transmission shaft 87. Further, the planting transmission shaft 87 is fitted with a tip cylinder 119 having a recess 120 with a rearward opening in which the tip shaft 118 is fitted, and the tip cylinder 119 meshes with the third constant velocity driven bevel gear 117. A third constant speed main driving bevel gear 121 is formed. Therefore, the tip shaft 118 and the tip cylinder 119 are always rotated together.

  As shown in FIG. 13, an outward key groove 122 is formed on the outer peripheral surface of the planting transmission shaft 87 so as to extend to the positions of the tip cylindrical body 119 and the tip shaft 118, and the key member 123 is formed in the outward key groove 122. Is slidably fitted. On the other hand, an inward key groove 124 facing the outward key groove 122 is formed on the inner peripheral surfaces of the front end cylindrical body 119 and the front end shaft 118. The key member 123 is integrally provided with a key portion 123 a that fits in the inward key groove 124.

  Therefore, when the key member 123 slides and the key portion 123a is selectively fitted into the inward key groove 124 of the distal end cylindrical body 119 and the inward key groove 124 of the distal end shaft 118, the planting transmission shaft 87 is The rotation is selectively transmitted to the third constant speed bevel gears 121 and 117 and the third inconstant speed bevel gears 98 and 99. Thereby, the planting center shaft 91 is switched between the constant speed rotation state and the non-constant speed rotation state.

  The front end portion of the key member 123 is integrally fixed to a slide ring 125 that is slidably fitted to the planting transmission shaft 87. An annular groove 126 is formed on the outer periphery of the slide ring 125. In addition, a lever 127 having a bifurcated portion 127 a straddling the slide ring 125 is connected to the support arm 31 so as to rotate about an axis perpendicular to the planting transmission shaft 87, and the bifurcated portion 127 a of the lever 127. In addition, a pin portion 127b is slidably fitted into the annular groove 126 of the slide ring 125.

  Therefore, by rotating the lever 127, the slide ring 125 can be slid to switch between constant speed rotation and non-constant speed rotation. The upper portion of the lever 127 protrudes above the support arm 31, and the upper end portion of the lever 127 is connected to a rib 128 formed on the support arm 31 with a pin. In this embodiment, the lever 127 is pushed in one direction by the spring 129, and the lever 127 can be pulled by the wire 130 against the spring 129. When the wire 130 is loosened, the lever 127 is rotated by the biasing force of the spring 129. As an operation means of the lever 127, an electromagnetic solenoid, a hydraulic cylinder, or the like can be used.

  As shown in FIG. 13D, it is also possible to use a rotary operation shaft 131 as the slide means of the slide ring 125. That is, a flat surface 131aa is formed at the lower end of the operation shaft 131. When the operation shaft 131 is rotated by 90 °, the flat surface 131a hits the side surface of the slide ring 125 and the outer periphery hits the side surface of the slide ring 125. Thus, the slide ring 125 slides.

  As a sliding means of the slide ring 125, it is also possible to form an inclined cam surface on the slide ring 125 and to apply a vertical movement type operation shaft to the inclined cam surface (that is, the slide ring 125 by a wedge action). Can also be slid.) Thus, when a rotary or vertical movement type operation shaft is employed, there is an advantage that the seal structure is simplified. In addition, when using the rotary or up-and-down operation shaft 131, the slide ring 125 needs to be biased by a spring in one direction.

(8) Third Embodiment Next, a third embodiment shown in FIG. 14 will be described. In this embodiment, the center case 30 is provided with unequal speed conversion means. In other words, in this embodiment, the planting output shaft 78 is configured to selectively impart non-uniform rotation and uniform rotation. In the third embodiment, power is transmitted from the second relay gear 80 to the third relay gear 82 of the idle shaft 81 as in the first embodiment. However, the number of teeth of the third relay gear 82 and the number of teeth of the second relay gear 80 are set to the same number.

  In this embodiment, the fifth constant speed main relay gear 133 and the fifth inconstant speed main relay gear 134 are rotatably fitted to the idle shaft 81, while the sleeve 83 provided on the planting output shaft 78 is fitted to the idle shaft 81. The fifth constant speed driven relay gear 135 and the fifth inconstant speed driven relay gear 136 are fixed. The constant speed relay gears 133 and 135 mesh with each other, and the inconstant speed relay gears 134 and 136 mesh with each other.

  The idle shaft 81 is formed with an outward key groove 122 as in the case of the second embodiment, and a key member 123 having a key portion 123a is slidably fitted in the outward key groove 122. Yes. On the other hand, an inward keyway 124 is formed in the fifth constant speed main relay gear 133 and the fifth inconstant speed main relay gear 134. A slide ring 125 is fixed to the key member 123, and the slide ring 125 is slid by an operation rod 138 that is slidably attached to the center case 30.

  The operating rod 138 has an engaging portion 138 a that fits in the annular groove 126 of the slide ring 125. Further, two engagement grooves 139 are formed in the operation rod 138, and the operation position is maintained by selectively fitting the ball 140 into one of the engagement grooves 139. The ball 140 is pressed by a spring 141.

  In this embodiment, the internal structure of the support arm 31 may be the same as before, and the respective planting drive shafts 32 are simultaneously switched between constant speed rotation and non-constant speed rotation. This simplifies the structure. When the unequal speed conversion means provided in the planting unit 2 is switched between the constant speed rotation and the unequal speed rotation, when this embodiment is adopted, the structure is particularly simple because only one switching is sufficient. In addition, it is the same as that of 1st Embodiment to have an inconstant speed conversion means in the stock change apparatus 26. FIG.

(9) Fourth to Eleventh Embodiments The fourth embodiment shown in FIG. 15 is applied to a type in which the rotation of the planting drive shaft 32 is transmitted to the planting central shaft 91 by a chain. That is, in this embodiment, the horizontally long idle shaft 142 is rotatably disposed on the rear end side of the support arm 31, and the driven sprocket 143 fitted to the idle shaft 142 is provided on the planting drive shaft 32. Power is transmitted from the main drive sprocket 144 by the chain 145, and further, from the idle shaft 142 to the planting center shaft 91, a pair of the main drive constant speed gear 146 and the driven constant speed gear 147, the main drive inconstant speed gear 148, and the driven inconstant speed gear. Power is selectively transmitted to the pair 149 (a belt can be used instead of the chain 145).

  The driven constant speed gear 147 and the driven inconstant speed gear 149 are fixed to the planting center shaft 91. On the other hand, a spline cylinder 150 having spline teeth formed on the outer periphery thereof is slidably and rotatably fitted to the idle shaft 142. The spline cylinder 150 is always meshed with the driven sprocket 143 and selectively meshed with the main driving constant speed gear 146 and the main driving inconstant speed gear 148 (therefore, the main driving constant speed gear 146 and the main driving inconstant speed gear 148 A spline groove is formed on the inner peripheral surface of.

  The spline cylinder 150 can be slid by a lever 151. As described above, the spline cylinder 150 is selectively meshed with the main driving constant speed gear 146 and the main driving inconstant speed gear 148, so that the rotation of the idle shaft 142 is driven by the driven constant speed gear 147 and the driven inconstant speed gear. 149 is selectively transmitted to 149, whereby the planting center shaft 91 is switched between constant speed rotation and non-constant speed rotation.

  The fifth embodiment shown in FIG. 16 is applied to the type in which the rotation of the planting drive shaft 32 is transmitted to the planting central shaft 91 by the chain 145 as in the fourth embodiment. In this embodiment, the main sprocket 144 provided on the planting drive shaft 32 and the driven sprocket 143 provided on the planting central shaft 91 are elliptical or other (non-circular) inconstant speed sprockets, so that the planting central shaft 91 Is imparted with non-uniform rotation. An idle roller 145 ′ is applied to the chain 145. It is also possible to use a belt (preferably a timing belt) instead of the chain.

  In the sixth embodiment shown in FIG. 17, a transmission mechanism including an internal gear 152 and a spur gear 153 meshing with the internal gear 152 is employed as the inconstant speed conversion means. That is, the main driving spur gear 153 is an eccentric inconstant speed gear, and the driven internal gear 152 is also an inconstant speed gear having a short circle portion and an oval portion. The number of teeth of the driven internal gear 152 is twice that of the main driven spur gear 153. Therefore, every time the main driven spur gear 153 makes one rotation, the driven internal gear 152 has an acceleration region. The deceleration area occurs twice.

  In the seventh and subsequent embodiments shown in FIG. 18, the rotation of the planting drive shaft 32 is applied to the type in which the rotation of the planting drive shaft 32 is transmitted to the planting central shaft 91 by the chain 145 as in the fourth embodiment. In the seventh embodiment, both the main sprocket 144 provided on the planting drive shaft 32 and the driven sprocket 143 provided on the idle shaft 142 are circular but eccentric inconstant speed sprockets, which are fixed to the idle shaft 142. By engaging the driven gear 155 fixed to the planting central shaft 91 with the main driving gear 154, the planting central shaft 91 is imparted with non-uniform speed rotation. The average reduction ratio in the chain 145 transmission is 1, but the reduction ratio in the gear transmission from the main driving gear 154 to the driven gear 155 is ½. An idle roller 145 ′ is applied to the chain 145. A belt may be used instead of the chain 145. It is also possible to adopt a configuration in which only one of the sprockets 143 and 144 is eccentric and not one.

  The eighth embodiment shown in FIG. 19 and the ninth embodiment shown in FIG. 20 are modifications of the fifth embodiment shown in FIG. In the eighth embodiment shown in FIG. 19, the main sprocket 144 provided on the planting drive shaft 32 is a circular constant velocity sprocket. In the ninth embodiment shown in FIG. 20, the main driving sprocket 144 provided on the planting drive shaft 32 is a circular but eccentric constant speed sprocket. In the eighth and ninth embodiments, the reduction ratio in the chain 145 transmission is an average of ½.

  In the tenth embodiment shown in FIG. 21, the main driving sprocket 144 provided on the planting drive shaft 32 is a circular but eccentric non-constant speed sprocket, and the driven sprocket 143 provided on the planting central shaft 91 is a circular constant speed sprocket. . In this case, the reduction ratio in the chain 145 transmission is also ½ on average.

  In the eleventh embodiment shown in FIG. 22, the main sprocket 144 provided on the planting drive shaft 32 is an infinite speed sprocket having an elliptical shape (non-circular), and the driven sprocket 143 provided on the planting central shaft 91 is polygonal ( Non-circular) non-uniform speed sprocket. In this case, the reduction ratio in the chain 145 transmission is also ½ on average. Since the driven sprocket 143 is formed in a substantially square shape, acceleration / deceleration occurs four times in one rotation of the planting center shaft 91.

(10). Others The present invention can be embodied in various ways other than the above embodiment. For example, when the bevel gear is an inconstant speed gear, the first bevel gear 71 can be an inconstant speed gear, and the second bevel gear 88 can be an inconstant speed gear. It is also possible to provide inconstant speed conversion means such as inconstant speed gears at three or more locations in the power transmission path. Furthermore, it is also possible to provide a plurality of unequal speed conversion means in the traveling machine body without providing the unequal speed conversion means in the planting part.

  Moreover, this invention is applicable to various seedling transplanting machines other than a rice transplanter. The stock change apparatus can also be built in the mission case. In this case, one inconstant speed conversion means is built in the mission case. In the case where unequal speed conversion means is provided for each of the traveling machine body and the planting part, the unequal speed conversion ratio may be set as necessary. Therefore, depending on the case, it is also possible to make the conversion ratio in the traveling body smaller than the conversion ratio in the planting unit 2.

  The present invention is embodied in a rice transplanter and exhibits utility. Therefore, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Traveling machine body 2 Planting part 3, 4 Wheel 7 Seedling stand 8 Planting device 10 Engine 11 Transmission case 26 Stock change device 27 Power transmission shaft for planting 29 PTO shaft constituting power transmission path 30 Center case 31 Support arm 32 Planting Drive shaft 36 Rotary case 37 Scraping unit 48 First inconstant speed gear 56 Second inconstant speed gear 71 First bevel gear 88 Second bevel gear 96 Planting claw 98 Third inconstant speed main driving bevel gear 99 Third inconstant speed driven Bevel gear

Claims (7)

A planting device that repeats scraping and planting and transplanting operations while traveling in the field, and a power source that drives the planting device, and is in a power transmission path from the power source to the planting device And a strain change device for changing the relationship between the traveling speed of the planting device and the transplanting operation speed, and an inconstant speed conversion means for imparting an inconstant speed rotation to the rotating shaft constituting the power transmission path. The unequal speed conversion means is provided at a plurality of locations in the power transmission path.
Seedling transplanter. It has a traveling machine body equipped with an engine as the power source, and a planting part arranged behind or in front of the traveling machine body, and the planting device is attached to the planting part,
The unequal speed conversion means is provided separately for the traveling machine body and the planting part,
The seedling transplanter according to claim 1. The unequal speed ratio of the unequal speed conversion means in the planting part is set smaller than the unequal speed ratio of the unequal speed conversion means in the traveling machine body,
The seedling transplanter according to claim 2. The inconstant speed conversion means of the planting part is provided at the end of the power transmission path,
The seedling transplanter according to claim 2 or 3. The power transmission path has rotating shafts intersecting each other, and the bevel gear is configured to transmit power to these intersecting rotating shafts, and the bevel gear is an inconstant speed gear.
The seedling transplanter according to claim 4. Power from the traveling machine body is input to the planting part by a PTO shaft extending long in the front-rear direction in a plan view, and the rotation of the PTO shaft is a horizontally long planting drive shaft via a first bevel gear pair. The rotation of the planting drive shaft is converted into the rotation of the longitudinal transmission gear shaft through the second bevel gear pair, and the rotation of the planting transmission shaft is laterally elongated through the third bevel gear pair. Converted to rotation of the planting center shaft, and the rotary planting device is attached to the planting center shaft, wherein the third bevel gear pair is an inconstant speed gear,
The seedling transplanter according to claim 2 or 3. The unequal speed conversion means in the traveling machine body is provided with a switching means between unequal speed rotation and constant speed rotation, and is switched to rotate at an unequal speed in a sparse planting state, while the unequal speed conversion in the planting part. The means are always set to rotate at a non-uniform speed,
The seedling transplanter according to claim 2 or 3.

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