Title of Invention

A RICE TRANSPLANTING MACHINE

Abstract

A working truck in which speed change function and handling performance are enhanced by providing a hydraulic speed change mechanism 57 and a transmission gear 74 for transmitting the driving power of an engine 2, forming a speed change output by combining outputs from the hydraulic speed change mechanism 57 and the transmission gear 74, obtaining an output of high power transmission efficiency using the transmission gear 74, obtaining a variable speed output capable of zero start using the hydraulic speed change mechanism 57 and performing speed regulation by a simple speed change operation depending on the situation, and in which creep speed performance is enhanced easily by rotating an output shaft 84 for combining and speed changing the outputs from the hydraulic speed change mechanism 57 and the transmission gear 74 uni-directionally by forward or reverse rotation of the hydraulic speed change mechanism 57 thereby ensuring the output torque easily at the time of zero start, while furthermore work efficiency on a muddy pavement is enhanced utilizing the output of high power transmission efficiency from the transmission gear 74 effectively at the working speed. Reference: Figure -1

Full Text

The present invention relates to a rice transplanting machine. TECHNICAL FIELD The present invention relates to a working truck such as a rice transplanter having seedling platforms and seedling planting pawls to continuously carry out rice transplanting operation, a tractor, a combined harvester and thresher, or earthmoving and construction equipment. BACKGROUND ART There is a prior technique of transmitting an output from an engine with changing its speed by utilizing differential operation of a planetary gear mechanism that combines an output from a hydraulic speed change mechanism or HST (Hydro-static transmission) and an output from a gear transmission, for example. In this prior technique, the planetary gear mechanism is set so that the combined output from the planetary gear mechanism is on forward and reverse sides of a stop (zero) to thereby obtain high power transmission efficiency and a continuous speed change capable of zero start. Specifically, when the combined output from the planetary gear mechanism is on the reverse side, a power is transmitted from the planetary gear mechanism to a pump shaft of the HST via hydraulic oil. Although the hydraulic transmission power reduces a speed change operating force of the HST, power transmission efficiency deteriorates due to the hydraulic transmission power. On the other hand, although the output efficiency is satisfactory at; the time of medium speed when the hydraulic transmission power from the planetary gear is zero and at the time of high speed when power is transmitted from the HST to the planetary gear, the speed change operating force becomes large. Furthermore, the operating force in operating a hydraulic speed change-operating arm from 0 to +1 is heavier than that in operating the arm from -1 to 0. The higher the speed, the larger the required operating force becomes. DISCLOSURE OF THE INVENTION The present invention provides a working truck comprising a HST 57 and a transmission gear 74 for transmitting driving power of an engine 2, respective outputs from the HST 57 and the transmission gear 74 being combined to form a speed change output, wherein a combining output shaft 84 for outputting the speed change output is rotated one-directionaily by forward or reverse output of the HST 57, Thus, output torque can easily be ensured at the time of zero start, creep speed traveling performance can easily be enhanced, and work efficiency on a muddy pavement can easily be enhanced by utilizing the output of high power transmission efficiency from the transmission gear 74 effectively at the working speed. Moreover, a combined speed change mechanism or HMT (hydro-mechanical transmission) 115 for forming a combined output of the outputs from the HST 57 and the planetary gear mechanism 83 for transmitting driving power of the engine 2 is provided, and a combining output shaft 84 of the HMT 115 is rotated one-directionally by a reverse output of the HST 57. Therefore, the power is transmitted from a combining part side to the hydraulic pump 85 of the HST 57 in a range of a light operating force of the speed change operating arm 109 to thereby easily speed change the HST 57 with the light operating force regardless of a load on the HST 57 to easily secure a continuous speed change capable of zero start and high transmission efficiency. Furthermore, the number of revolutions of an output shaft of the HST 57 is made approximately zero in a state of the highest rotation of the combining output shaft 84. Therefore, the driving power from the engine? 2 is transmitted to the transmission case 4 with maximum efficiency in. tho state of the highest rotation of the combining output shaft 84 to thereby improve workability by enhancing travelability. Moreover, a HMT 115 for forming a combined output of the outputs from the HST 57 and the planetary gear mechanism 83 for transmitting driving power of the engine 2 and a combined output speed change mechanism 4a for speed changing the combined output in multiple stages are provided, and a clutch 116 is interposed between the complex and combined output speed change mechanisms 115, 4a. Therefore, the shaft 84 pivotally supporting the speed change gears 87, 88 is brought into a free rotating state by disengaging the clutch 116 at the time of speed change operation to perform smooth speed change, and transmitted driving power is certainly cut off regardless of the speed change state (forward, neutral, reverse) to thereby improve speed change precision. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a general side view of a rice transplanter; FIG. 2 is a general plan view of the rice transplanter FIG. 3 is a side view of a travel vehicle. FIG. 4 is a plan view of the travel vehicle; FIG. 5 is a side view of a vehicle frame; FIG. G is a side explanatory view of a driving portion; FIG. 7 is a plan explanatory view of the driving portion,' FIG. 8 is a side explanatory view of a side clutch operating system; FIG. 9 is a plan explanatory view of the side clutch operating system; FIG. 10 is a perspective explanatory view of a vehicle body; FIG. 11 is a sectional view of a transmission case." FIG. 12 is an explanatory view of a traveling driving portion of the transmission case; FIG. 13 is an explanatory view of a planetary gear mechanism; FIG. 14 is a partial view of the transmission case; FIG. 15 is a sectional view of the planetary gear mechanism; FIG. 1G is an explanatory view of a gear arrangement of the transmission case; FIG. 17 is a side view of a hydraulic speed change operating arm; PIG. 18 is an explanatory view of an engine output; FIG. 19 is an explanatory view of rotation of the planetary gear mechanism; FIG. 20 is an explanatory view of an engine output in traveling at a low speed; FIG. 21 is an explanatory view of an engine output in traveling at a high speed; FIGS, 22(l) and 22(2) are explanatory views of outputs; FIG. 23 is an explanatory view of an output of a combining output shaft; FIG. 24 is an explanatory view of a clutch portion; FIG. 25 is an explanatory view of the clutch portion; FIG. 26 is an explanatory view of spline portions; FIG. 27 is an explanatory view of a speed change shaft portion; FIG. 28 is an explanatory view of a front lid portion; and FIG. 29 is an explanatory view of an arrangement of a breather portion. BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below in detail based on the drawings. FIG, 1 is a general side view, FIG. 2 is a general plan view, FIG. 3 is a side view of a vehicle framo, and PIG. 4 is A plan view of the vehicle frame. In the figures, a reference numeral 1 designates a travel vehicle on which an operator rides. An engine 2 is mounted on the vehicle frame 3. Paddy field traveling front wheels 6 are supported through front axle cases 5 on sides of a transmission case 4. Paddy field traveling rear wheels 8 are supported by a rear axle case 7 behind the transmission case 4. Auxiliary seedling platforms 10 are mounted on opposite sides of a hood 9 for covering the engine 2 and the; like. A vehicle body cover 11 on which the operator rides covers the transmission case 4 and the like. A driver's seat 13 is mounted to an upper portion of a rear side of the vehicle body cover 11 through a seat frame 12. A steering wheel 14 is provided to a rear portion of the hood 9 in front of the driver's seat 13. In the figure, a reference numeral 15 designates a planting portion including seedling platforms 16 for five-row planting, a plurality of seedling planting pawls 17, and the like. The forward-inclined seedling platforms 16 made of synthetic resin and having higher front portions and lower roar portions are supported for lateral sliding in a reciprocatable manner on planting cases 20 through a lower rail 18 and a guide rail 19. Rotary cases 21 for rotating in one direction at a constant speed are supported on the planting cases 20. A pair of pawl cases 22, 22 are disposed symmetrically with respect to a rotation axis of each of the cases 21. The seedling planting pawls 17, 17 are attached to tip ends of the pawl cases 22, 22. A hitch bracket 23 in front of the planting cases 20 is coupled to a rear side of the travel vehicle 1 through a lifting/lowering link mechanism 26 including a top link 24 and a lower link 25. The thus travel vehicle is constructed so that a hydraulic lifting/lowering cylinder 27 for lifting/lowering the planting portion 15 through the link mechanism 20 is coupled to the lower link 25. The front and rear wheels 6, 8 are driven for traveling to move and, at the same time, the seedling for one plant is taken out with the planting pawls 17 from the seedling platforms 16 for laterally sliding in the reciprocatable manner to carry out rice transplanting operation for continuously transplanting the seedling. In the figures, a reference numeral 28 designates a main speed change lever, 29 designates a planting operating lever for carrying out engagement/disengagement of position of the driver's seat 13, respectively, Furthermore, in the figures, a reference numeral 36 designates a one-row leveling center float, 37 designates a two-row leveling side float, and 38 designates a five-row side-fur row fertilizer applicator for discharging fertilizer in a fertiliser hopper 39 into side furrow openers 42 of the floats 36, 37 by draft power of a blower 40 through a flexible carriage hose 41. As shown in FIGS. 3 to 5, the vehicle frame 3 is divided into three parts, i.e., front portion frames 43, middle frames 44 and rear portion frames 45. The pair of left and right front portion frames 43 is providc-ui with the engine 2. The pair of left arid, right middle frames 44 is provided with the front axle cases 5. The pair of left and right rear portion frames 45 is provided with the rear axle case 7 and a fuel tank 46 for supplying fuel to the engine 2. A front frame 47 and a base frame 48 are respectively coupled to front sides and middle portions of the front portion frames 43 to form a rectangular frame shape in a plan view and the engine 2 is mounted on fixed brackets 49 and the base frame 48 through rubber cushions. As shown also in FIG. 10, middle rising portions 50 of the rear portion frames 45 are coupled with each other substantially in parallel by a pipe frame 51 and a gate-shaped frame 52. Rear ends of a gate frame 53 with its left and right lower ends fixed to the rear axle case 7 are coupled integrally. The fuel tank 46 is disposed between the left and right rising portions 50. Moreover, front and rear ends of the left and right middle frames 44 are detachably fixed to rear ends of the front portion frames 43 and front, ends of the rear portion frames 45 through bolts 54. The left and right front axle cases 5 are detachably fixed to lower faces of the left and right middle frames 44 through bolts 55, respectively. The left and right front axle cases 5 are connected and fixed to the transmission case 4. As shown in. FIGS. 6 to 10, a power steering case 56 is provided on a left side of a front face of the transmission caae 4, a HST (Hydro-static transmission) 57 for changing a transmitting speed in a non-stepwise manner is provided on the right side of the transmission case 4, a speed change inputting pump shaft 58 of the HST 57 projects in a forward • direction of the vehicle body and is coupled to a transmission shaft 59 in a front'to'rear direction under the engine 2. The transmission shaft 59 is coupled to an output shaft 60 of the engine 2 through a transmission belt 61 to thereby transmit an output of the engine 2 to the HST 57. The transmission case 4 and the rear axle case 7 are integrally coupled to each other by a pipe-shaped coupling frame 62 on a center-line in the front'tO'rear direction of the vehicle body. A rear output shaft 63 and a PTO output shaft 64 projects rearward from the transmission case 4. The rear output shaft 63 is coupled to a rear input shaft 65 projecting forward from the rear axle case 7 through a rear transmission shaft 66 to thereby transmit power from the traveling output shaft 63 to the left and right roar wheels 8. The PTO output shaft 64 is coupled to an intermediate shaft 68 provided to a bearing 67 at an upper portion of the rear axle case 7 through a universal joint shaft 69. The intermediate shaft 68 is coupled to inpul: shafts of the planting cases 20 through universal joint shafts to thereby transmit power from the PTO output shaft 64 to the planting portion 15. Moreover, as shown in FIGS. 11 to 16, the transmission case 4 includes a main body portion 70, a front lid portion 71 and a rear lid portion 72. The respective lid portions 71, 72 are detachably fixed through bolts to the front and rear of the body portion 70 to form an airtight box shape. A partition wall portion 73 for dividing- an inside of the body portion 70 into front and rear parts is provided. The HST 57 is mounted to a front face of the front lid portion 71, a small-diameter transmission gear 74 is fixedly mounted on the pump shaft 58 projecting into the transmission case 4, The transmission gear 74 is supported by the front lid portion 71 through A sun gear 78 is engaged with a motor shaft 77 of the HST 57 projecting into the transmission case 4. The sun gear 78 is supported on the front lid portion 71 through a bearing, A large-diameter carrier gear 79 is constantly engaged with the small 'diameter transmission gear 74. The carrier gear 79 is supported in a rotatable manner on a boss portion of the sun gear 78. Three planetary gears 80 are rotatably provided to the carrier gear 79 through shafts 81. The planetary gears 80 are engaged'with the sun gear 78. A ring gear 82 to be engaged with the planetary gears 80 is provided. The respective gears 78, 80 and 82 form a planetary gear mechanism 83. The front and rear of a combining output shaft 84 are rotatably supported by the sun gear 78 and the rear lid portion 72, The ring gear 82 is engaged with the combining output shaft 84. Forward/reverse rotation outputs from the HST 57 having a hydraulic pump 85 and a hydraulic motor 86 and decelerated rotation outputs (one-directional constant rotation) from the transmission gear 74 and the carrier gear 79 are combined by differential operation of the planetary gear mechanism 33. The combined output is transmitted to the combining output shaft 84 as u one-directional rotating force having a range of /ero to maximum speeds. Furthermore, a forward gear 87 and a reverse gear 88 are axially supported in the rotatable manner on the combining output shaft 84. The respective gears 87, 88 are selectively engaged with the combining output shaft 84 by a slider 89 to switch to a forward, neutral or reverse output, The rear output shaft 63 is supported on the partition wall portion 73 and the rear lid portion 72 through bearings. A front output shaft 92 and a counter shaft 94 are provided. The front output shaft 92 is provided for transmitting power to left and right front axles 91 through a differential gear 90. The counter shaft: is provided for supporting a PTO speed change gear 93 is engaged and axially supported are provided. Reverse power of the reverse gear 88 is transmitted to the rear and front output shafts 63,1)2 through output gears 95, 96 to drive the front and rear wheels 6, 8 for reverse traveling. A moving gear 97 and a planting gear 98 are supported in the rotatable manner on the rear output shaft 63, and the respective gears 97, 98 are selectively engaged with the rear output shaft 63 by an auxiliary speed change slider 99. The moving gear 97 is constantly engaged with the-; forward gear 87 through high speed gears 100a, l00b of the counter shaft 94, and the planting gear 98 is constantly engaged with the PTO speed change gear 93 for low speed of the counter shaft 94 to transmit power of the forward gear 87 to the respective output shafts 63, 92 through the respective gears lOOn, 93, 98 to drive the front and rear wheels 6, 8 for forward traveling at a speed of planting operation of the seedling. Manual rotation of the PTO output shaft 64 is made possible so that both the moving gear 97 and the planting gear 98 are brought into fraoly rotating states and that the operator can manually rotate the planting pawls 17 and the like to remove the crowded seedling. Power of the forward gear 87 is transmitted to the respective output shafts 63, 92 through the respective gears lOOa, lOOb to drive the front and rear wheels 6, 8 at high moving speeds for moving on a road between farming fields. Moreover, as shown in FIG. 1 i, power of the PTC) speed change gear 93 is transmitted to the PTO output, .shaft 64 through u PTO speed change shaft 101 and a PTO speed change mechanism 102 to drive the planting?, portion 15 so that the speed can be changed freely between the plants. A fertilizer applying output shaft 1,04 is coupled to the PTO output shaft 64 through a chain 103 provided inside the transmission case 4 to drive a fertilizer applicator 38 in synchronization with the planting portion 15. As shown in FIG. 13, an oil gage 105 is provided in the transmission case 4. As shown in FIG. 14, the respective sliders 89, 99 are supported to the same shifter fork 106 and a switch between forward and reverse traveling and a switch of auxiliary speed change (low and high speeds) are made by five-position switching of the vspeed change lever 28. Ae shown in FIGS. 16 and 17, a hydraulic speed change-operating arm 109 is coupled to a swash plate 107 of the hydraulic pump 85 through a control shaft 108. A speed change pedal 31 is coupled to the arm 109 through a rod 110. A spring 111 for automatically returning the pedal 31 to a stop (speed, zero) position by releasing the depressed pedal 31 from the foot is coupled to the arm 1.09, and an oil damper 112 is connected to the arm 109 so that the pedal 31 is returned at a substantially constant Blow speed by resistance of the oil damper 112 and a returning force of the spring 111 and r.tu)t the speed is reduced gradually when the depressed pedal 31 is released from the foot, The constant-speed actuating member may be formed of a gas spring instead of the oil damper 112. Furthermore, as shown in PIG. 19, when the pedal 31 has been released from the foot and has been returned to the stop (speed zero) position by the spring 111, the sun gear 78 rotates reversely and clockwise at highest rotation to cause the planetary gears 80 to rotate counterclockwise and, at the same time, to cause the planetary gears 80 to revolute clockwise and rotate counterclockwise by rotating the carrier gear 79 by the transmission gear 74 to thereby make rotation of the ring gear 82 zero and keep the combining output shaft 84 stopped. When the pedal 31 is depressed with the foot against the spring 111, the sun gear 78 is stopped, the carrier gear 79 is rotated by the transmission gear 74, the planetary gears 80 are caused to rotate clockwise while revolving clockwise, and the combining output shaft 84 is rotated by gear power of the transmission gear 74. As shown in FIG. 18, power of the engine 2 is transmitted to the transmission gear 74 and the HST 57, and is combined and output by the planetary gear mechanism 83. Then switching between the forward and reverse traveling and PTO speed change are carried out in the transmission case 4 to carry out respective operations of reverse traveling, low-speed forward traveling (traveling for planting in the farming field), and high-speed forward traveling (traveling for moving on the road). For example, while output powor P2 is about 70% of input power PI in a conventional HST 57, a part of the gear transmission power P3 is returned to the pump shaft 58 as hydraulic transmission power P4 in traveling at a low speed to increase the output power P2 to about 80% of the input power PI as shown in FIG. 20. In traveling at a high speed when the hydraulic transmission power of the HST 57 is zero (P4 = ()), a hydraulic loss is avoided to achieve high-efficiency rotation with which the output power P2 is increased to about 95% or more of the input power Pi as shown in FIG. 21. In this embodiment, when an angle of the hydraulic speed change-operating arm 109 is changed from -1 to 0, -1000 to 0 rpm of the motor shaft 77 is obtained as shown in FIG. 22(l). The gears 74, 79 and the planetary gear mechanism 83 arc formed so that 0 to 1000 rpm of the combining output shaft 84 is obtained with respect to the angle of the ann 109 as shown in FIG. 23 when the gear 74 side is rotated 1000 times irrespective of the angle of the arm 109 as shown in FIG. 22(2). If an overall range of control of the arm 109 is -1 to 0, low-speed (zero speed) side and high-speed side control operations of the arm 109 are restricted by bolt-type low-speed and high-speed stoppers 113, 114 as shown in FIG. 17. As is apparent from the above description, the HST 57 and the transmission gear 74 for transmitting the driving powor of the engine 2 are provided, the speed change output is formed by combining the respective outputs from the HST 57 and the transmission gear 74. Specifically, while the output of high power transmission efficiency is obtained by using the transmission gear 74, the variable speed output capable of zero start iy obtained by using the HST 57. Furthermore, speed regulation depending on the situation is performed by a simple speed change operation of the HST to thereby enhance speed change function and handling performance. Furthermore, creep speed traveling' performance is enhanced by causing the combining output shaft 84 for combining; and outputting the respective outputs from the HST 57 arid the transmission gear 74 to rotate in one direction with forward or reverse rotation output of the HST 57, Therefore, the output torque is easily ensured at the time of zero start, while furthermore work efficiency on a muddy pavement is enhanced utilizing the output of high power transmission efficiency from the transmission gear- 74 effectively at the working apeed. Moreover, the working truck is constructed to have a HMT (hydro-mechanical transmission) 115 including HST 57 and the planetary gear mechanism 83 for transmitting driving power of thy engine 2. Th« HMT is formed so that the combining output shaft 84 of the HMT 115 rotates one-directionally by using reverse rotation output of the HST 57. In the HMT, power is transmitted from a combining part- side to the hydraulic pump 85 of the HST 57 in a range of —1 to 0 side of the speed change operating arm 109 having an operating force lighter than 0 to + side. Therefore, speed of the HST 57 can be easily changed with the light operating force regardless of a load on the HST 57, with obtaining a continuous speed change capable of zero start and high transmission efficiency. Moreover, in the HMT, the highest rotation of the combining output shaft 84 is obtained by making the number of revolutions of the output shaft of the HST 57 approximately aero. Therefore, the driving power from the engine 2 is transmitted to the transmission case 4 with maximum efficiency in the state of the highest rotation of the combining output shaft 84 to thereby improve workability such as enhancing travelability. Moreover, the HMT 115 for forming the combined output of outputs from the HST 57 and the planetary gear mechanism 83 Tor transmitting driving power of the engine 2 and a combined output speed change mechanism 4a for speed changing the combined output in multiple stages are provided, and a clutch 116 is interposed between the complex and combined output speed change mechanisms 115, 4a. The shaft 84 pivotally supporting the speed change gears 87, 88 is brought into a free rotating state by disengaging the clutch 116 at the time of speed change operation to perform smooth speed change, and transmission driving power is certainly cut off regardless of the speed change state (forward, neutral, reverse) to thereby improve speed change precision. As shown in FIGS. 11, 12, 16, 24 and 25, the ball-joint-type main clutch 116 is interposed between the ring gear 82 and the forward gear 87 of the combining output shaft 84. The ring gear 82 is rotatably supported on a sleeve 117 spline-fitted to the combining output shaft 84, balls 119 capable of rushing into a ball groove 118 in an outer periphery of the sleeve 117 are embedded in a boss portion 82a of the ring gear 82. As shown in FIG. 24, when the balls 119 are pressed to rush into the ball groove 118 with a clutch body 121 slid over the sleeve 117 with a shifter fork 120, the main clutch 116 is engaged to transmit; rotation of the ring gear 82 to the combining output shaft 84. As shown in FIG. 25, when tho clutch body 3 23 is slid against a clutch spring 122 with the shifter fork 3.20 to release the balls 11.9 from the press, the balls 119 arc separated from the ball groove 118 by a rotary centrifugal action and the main clutch 1.3.6 is disengaged to thereby cut off power transmission from the ring gear 82 to the combining output shaft 84. As shown in FIGS. 14, 24 and 25, when the sliders 89, 99 operated by the shifter fork 106 are in reverse positions (the rightmost positions in FIG. 24), the slider 89 is spline-fitted to respective splines 84a, 88a of the combining output shaft 84 and the reverse gear 88 and the slider 99 is spline-fitted to a spline 98a of the planting gear 98. When the sliders 89, 99 arc switched from the reverse position:-) to neutral positions (solid-lino positions in FIG. 24), the slider 89 is spline-fitted to the spline 84a of tat; combining output shaft 84 and the slider 99 is spline-fitted to the spline 98a of the planting gear 98. When the slider 99 is switched from the reverse position to the neutral position, in order to avoid spline-fitting (engagement) of a spline 63a of the rear output shaft 63 to which the slider 99 is spline-fitted in forward movement and the slider 99 to each other, an. overlap portion of the spline 63a interfering with the slider 99 is formed into a cylindrical guide portion 63b having a .smooth surface to thereby facilitate switching of the sliders 89, 99 from the reverse positions to the neutral positions. As shown in FIG. 26, a backlash is secured between the slider 99 and the rear output shaft 63 which are spline-fitted to each other in forward movement. A cog thickness straddling' width b of each spline hole 99a of the slider 99 is formed to bo greater than a cog thicknens a of the spline 63a of the rear output shaft 63, and a tip end portion of each cog of the spline 63a is pointed and formed into a chamfered portion 63b for resolving a spline phase shift to thereby facilitate engagement in spline fitting of the slider 99 and the rear output shaft 63 to each other. As is apparent from the above description, the HMT 115 for forming the combined output of outputs from the HST 57 and the planetary gear mechanism 83 for transmitting driving power of the engine 2 and the speed change gear mechanism 4a of the transmission case 4 which is the combined output speed change mechanism for- speed changing the combined output from the HMT in multiple stages are provided, and the clutch 116 is interposed between the HMT 115 and the speed change gear mechanism 4a. As a result, the shaft pivotally supporting the speed change gears 87, 88 is brought into a free rotating state by disengaging the clutch 116 at the time of speed change operation to perform smooth speed change, and transmission driving power is certainly cut off regardless of the speed change state (forward, neutral, reverse) to thereby improve speed change precision. Furthermore, by providing speed change switching mechanism for carrying out the speed change by switching the sleeves 89, 99 which are two spline-fitting members to be integrally coupled and providing the cylindrical guide portion 63b which is a loosely fitting portion for avoiding engagement of the spline of the sleeve 99 to the apline G3a of the rear output shaft 63 as the spline member, smooth speed change switching irrespective of the phase can be achieved easily to enhance speed change operating performance oven when there is a phase shift between the sleeve 99 and the spline 63a to be engaged with the sleeve 99 in speed change switching from reverse to neutral, for example. As shown in FIGS. 11 and 27, the PTO speed change gear 93 of the counter shaft 94 has inter-plant speed change gears 93a, 93b, 93c, 93d, 5)3e for 50, 60, 70, 80 and 90 plants, and the PTO speed change shaft 101 has inter-plant gears 123a, 123b, 123e, 123d, 123e constantly engaged with the respective gears 93a, 93b, 93e, 93d, 93e. In the PTO speed change shaft 101, a speed change rod 125 is inserted in a slidable manner in an axial direction into a center of a cylindrical shaft through a guide 124, and balls 126 (three for each gear) for engaging and coupling the respective gears 123a to 123e and the speed change shaft 101 are embedded in ball grooves 127 in the speed change shaft .101. When a large "diameter clutch body 128 formed on the speed change rod 125 is moved to press and lock the balls 126 into a ball engaging groove 129 of one of the respective gears 123a to 123e with the clutch body 128, the gear 123a, 123b, 123c, 123d or 123e is coupled to the speed change shaft 101 to rotate the speed change shaft 101 at a predetermined inter-plant speed. Moreover, a plurality of detent grooves 130 are ibrmed in & front extending end of the speed change rod 125, and a detent balls 131 to be engaged with the grooves 130 is provided inside the transmission case 4 through a compression spring 132 to form a detent portion 133, so that positioning of the speed change rod 125 is carried out by engagement of the detent grooves 130 and the ball 131 with each other. By directly providing the detent portion 133 coaxially with the speed change shaft 124, a position of the speed change rod 125 can reliably be fixed with a simple structure; having the small number of parts. Between the speed change shaft 101 and the speed change rod 125 outside the inter-plant gears 123a to '123e with respect to the axial direction, an overstroke-preventing ball 134 is encapsulated through a gear collar 135 and an inter-plant power transmission gear 136. In an overstroke state in which the speed change rod 126 moves a predetermined distance or more, the clutch body 128 is brought in contact with the ball 134 to prevent overstroke of the speed change rod 126. In this case, the special overstroke-preventing member is not separately provided but. is integrated in a compact manner into the speed change shaft 101 to thereby simplify the structure and reduce the cost. As shown in FIG. 28, a periphery of the planetary gear mechanism 83 of the front lid portion 71 of the transmission case 4 is surrounded with a peripheral side wall 71a of the front lid portion 71 and a rib 137 erected from an inner side wall to suppress agitation of oil in the transmission case 4 by the planetary gear mechanism 83, thereby suppressing increase in oil temperature so as to obtain a satisfactory heat balances. As shown in FIG. 29, a breather 1.39 disposed on a lower right Bide of the driver's seat 13 is coupled through a flexible resin pipe 140 to an elbow pipe 138 at an upper portion of a rear side of the transmission case 4. The breather 139 is coupled to a right vortical frame portion of the gate-shaped frame 52 and is disposed above an xipper face of the transmission case 4 and above a step (portion under feet) l1a of the vehicle body cover 11 to thereby prevent a leakage of oil in the transmission case 4 from the breather 139 and reliably prevent entrance of muddy water on the step lla from the breather 139. The breather 139 may be mounted to any other members such as the gate-shaped frame 52 and the right rear portion frame 45. Claim: 1. A rice transplanting machine including a traveling vehicle (1) which has front wheels (6) and rear wheels (8) and on which an engine (2) is mounted, a planting portion (15) connected to the traveling vehicle (1). a hydrostatic transmission (57) that changes a speed of a rotational power input from the engine and that outputs a speed-changed power, a planetary gear mechanism (83) that combines the rotational power from the engine and the speed-changed power from the hydrostatic transmission to form a combined power, a combining output shaft (84) to which the combined power is transmitted from the planetary gear mechanism, and a transmission case (4) that includes a traveling output shaft (63) for outputting a rotational power toward the rear wheels and a PTO output shaft (64) for outputting a rotational power toward the planting part, the rice transplanting machine being characterized in that. the planetary gear mechanism is configured so that the speed of the rotational power of the combined output shaft is changed from zero to a maximum speed in one direction as the speed of the speed-changed power of the hydrostatic transmission is changed from a maximum speed in a reverse direction to zero. the rotational power of the combining output shaft in the one direction is operatively transmitted to the traveling output shaft trough a front gear (87) or a reverse gear (88) mounted on the combining output shaft so that the traveling output shaft is selectively in a forward rotational state, neutral state or a reverse rotational state, and the rotational power of the combined output shaft in the one direction is also operatively transmitted to the PTO output shaft.

Documents:

2097-DELNP-2004-Abstract-(04-03-2009).pdf

2097-delnp-2004-abstract.pdf

2097-DELNP-2004-Claims-(04-03-2009).pdf

2097-delnp-2004-claims.pdf

2097-DELNP-2004-Correspondence-Others-(04-03-2009).pdf

2097-DELNP-2004-Correspondence-Others-(09-03-2010).pdf

2097-DELNP-2004-Correspondence-Others-(14-09-2009).pdf

2097-delnp-2004-correspondence-others.pdf

2097-DELNP-2004-Description (Complete)-(04-03-2009).pdf

2097-delnp-2004-description (complete).pdf

2097-DELNP-2004-Drawings-(04-03-2009).pdf

2097-delnp-2004-drawings.pdf

2097-DELNP-2004-Form-1-(04-03-2009).pdf

2097-delnp-2004-form-1.pdf

2097-delnp-2004-form-18.pdf

2097-DELNP-2004-Form-2-(04-03-2009).pdf

2097-delnp-2004-form-2.pdf

2097-DELNP-2004-Form-3-(04-03-2009).pdf

2097-delnp-2004-form-3.pdf

2097-delnp-2004-form-5.pdf

2097-delnp-2004-gpa.pdf

2097-delnp-2004-pct-210.pdf

2097-delnp-2004-pct-304.pdf

2097-delnp-2004-pct-409.pdf

2097-DELNP-2004-Petition-137-(04-03-2009).pdf

2097-DELNP-2004-Petition-137-(14-09-2009).pdf

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