JP4297572B2 - Ride type rice transplanter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a four-wheel drive type rice transplanter having left and right front wheels that can be steered and left and right rear wheels that cannot be steered.
[0002]
[Prior art]
  In the riding type rice transplanter, the left and right front wheels are driven through a differential mechanism, and the left and right rear wheels are driven at a constant speed through side clutches and brakes. A pair of left and right side clutch brake pedals that operate the side clutch and brake independently on the left and right sides are arranged in parallel on the right side of the feet of the boarding operation unit.
[0003]
  In the above configuration, the steering wheel is steered and only one side clutch brake pedal on the inside of the turn is depressed, the side clutch on the inside of the turn is turned off, and the side brake on the inside of the turn is braked. Thus, the aircraft can be turned around.
[0004]
  Incidentally, if the left and right rear wheels are driven through the differential mechanism in the same manner as the tractor, the driving speed of the left and right rear wheels is automatically changed during turning, and smooth turning can be performed. Since the rotation speed of the left and right rear wheels changes according to the load, in a paddy field where there is unevenness in the tiller and the ground contact load of the left and right rear wheels tends to change greatly, the straightness is reduced, making it difficult to control the aircraft Become. Therefore, in paddy field work machines such as riding type rice transplanters where straight traveling is regarded as important, side clutch and brake systems are adopted for the left and right rear wheels.
[0005]
[Problems to be solved by the invention]
  Although the riding type rice transplanter provided with the traveling system having the above structure excellent in straight traveling performance is suitable for planting traveling in a paddy field, there is a problem in turning performance at the coast. In other words, when the aircraft is to make a large U-turn at the shore, if the aircraft is turned by depressing the side clutch brake pedal, the rear wheel inside the turn will be fixed by the side brake. As a result, the farming field is greatly damaged, and a problem that the traveling load increases is likely to occur. This tendency was particularly strong in deep fields.
[0006]
  The present invention has been made paying attention to such a situation, and can be turned lightly without damaging the field, and has excellent operability when turning the fuselage on the shore. The main purpose is to provide a type rice transplanter.
[0007]
[Means for Solving the Problems]
  [Configuration, operation and effect of the invention of claim 1]
[0008]
(Configuration) The riding type rice transplanter of the invention according to claim 1 is:The power of the engine is transmitted to the hydraulic continuously variable transmission, and the hydraulic continuously variable transmissionThe power is transmitted to the left and right front wheels that can be steered and the left and right rear wheels that cannot be steered.To do. Without a brake to brake only the right rear wheel, without a brake to brake only the left rear wheel,Friction-type side clutch for each of the left and right rear wheelsPrepared,A side clutch automatic operation mechanism is provided that allows the side clutch inside the turn to be disengaged only when the front wheel is steered beyond the set reference angle. A vehicle body stop pedal is provided at the right foot portion of the boarding operation unit so that the main clutch is disengaged and the vehicle body stop brake is braked only by the vehicle body stop pedal.There is no pedal to operate only the main clutch. The side clutch automatic operation mechanism and the main clutch being disengaged only by the airframe stop pedal and the airframe stop brake being braked are configured to operate independently of each other.
[0009]
(Effect) According to the above configuration, when the direction of the body is changed at the side of the heel and the like, if the front wheel is largely steered, the side clutch of only one rear wheel that is automatically turned inside is turned off. According to this, the aircraft turns by driving with the left and right front wheels and the rear wheels on the outside of the turn, and at this time, the rear wheels inside the turn with the side clutch disengaged are in an idle state. Follows and rotates with ease as it moves.
[0010]
[0011]
[0012]
[0013]
[0014]
(Effect) Therefore, according to the invention according to claim 1, the side brakes of the left and right rear wheels are abolished so that only one of the side clutches is turned off when turning, so that the side clutch / brake is This side clutch can be used to suppress the roughing of the field and the increase in travel load caused by dragging the rear wheels inside the turn, which is a problem found in the conventional configuration of turning by using this, and can smoothly turn the body and lightly. This makes it possible for an inexperienced worker to turn on the heel appropriately and easily just by steering the front wheels.
[0015]
  [Configuration, operation and effect of invention of claim 2]
[0016]
(Configuration) The riding type rice transplanter of the invention according to claim 2 is the invention of claim 1, so that when the front wheel is steered to the maximum and the U-turn is turned, the center of the aircraft body is in a substantially adjacent planting state. The maximum steering angle of the front wheels is set.
[0017]
(Action / Effect) According to the above configuration, when the end of the planting run of one stroke is reached, the front wheel is steered to the maximum and the U-turn is turned, so that the steering correction is almost correct. Even if it is not performed, it is possible to move to the planting run of the next stroke, the small turning of the aircraft can be performed smoothly and easily, and the steering operation of the front wheels for troublesome alignment can be simplified, even for inexperienced workers Reciprocal planting can be performed.
[0018]
  [Configuration, operation and effect of invention of claim 3]
[0019]
(Structure) The riding type rice transplanter of the invention according to claim 3 is provided with a power steering device for steering the front wheels in the invention of claim 1 or 2.
[0020]
(Action / Effect) According to the above configuration, the steering operation of the front wheels can be easily performed by the power steering device, so that the steering operation of the front wheels can be quickly and easily performed on the shore where the steering operation of the large front wheels is necessary. It is possible to perform smooth turning by operating the side clutch automatic operation mechanism more accurately and lightly.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
  FIG. 1 and FIG. 2 show a riding type rice transplanter of a five-row planting specification. This riding type rice transplanter has a five-row planting seedling planted on the rear part of a riding type self-propelled body 3 having a pair of left and right front wheels 1 that can be steered and a pair of rear wheels 2 that cannot be steered. The device 4 is connected to be movable up and down via a four-link mechanism 5 driven by a lifting cylinder 6,Of self-propelled aircraft 3It has a structure equipped with a fertilizer application device 5 in the rear part.
[0022]
  A transmission case 9 provided with a front axle case 9a that pivotally supports the front wheel 1 is connected and fixed to the front part of the body frame 8 of the self-propelled body 3, and the rear wheel 2 is connected to the rear part of the body frame 8. A rear transmission case 10 that supports the shaft is supported in a freely rolling manner. In addition, an engine 11 having a lateral output shaft 11 a is mounted via a vibration-proof rubber 12 at a position near the front of the mission case 9, and a boarding operation unit 13 is provided in a state of being positioned behind the engine 11. ing. The boarding operation unit 13 is provided with a steering handle 14, a driving seat 15, a driving step 24, and the like for steering the front wheel 1.
[0023]
  The seedling planting device 4 mounts seedlings for 5 lines and cuts seedlings one by one from the lower end of the seedling platform 16 and the seedling platform 16 which are reciprocated by a set stroke in the left-right direction. It consists of five rotary planting mechanisms 17 for planting, three leveling floats 18 for leveling the planting location, etc., and reserve seedlings for replenishing the seedling platform 16 in multiple stages. Spare seedling platforms 49 to be placed and accommodated are arranged on the left and right of the front part of the aircraft.
[0024]
  The fertilizer application device 7 is mounted on the self-propelled aircraft 3 between the driver seat 15 and the seedling planting device 4, and sets a fertilizer hopper 19 for storing powdered fertilizer and a fertilizer in the fertilizer hopper 19. A feeding mechanism 20 that feeds out by quantity, an electric fan 23 that air-feeds the fed fertilizer through a supply hose 22 to a grooving device 21 provided in the leveling float 18 of the seedling planting device 4, and the like.
[0025]
  As shown in FIGS. 3 and 4, on the left side surface of the transmission case 9 is a main transmission having a lateral input shaft 41a linked to the output shaft 11a of the engine 11 via a belt transmission device 40. The hydrostatic continuously variable transmission (HST) 41 is connected in a state in which its output is transmitted to the mission case 9 by a laterally oriented shaft, and the input shaft 41a and the output shaft 41b are connected to the front and rear. Has been.
[0026]
  The belt transmission device 40 winds a transmission belt 40c between an output pulley 40a attached to the output shaft 11a of the engine 11 and an input pulley 40b attached to the input shaft 41a of the hydrostatic continuously variable transmission 41, and this transmission belt. A tension pulley 40d is provided to apply tension to 40c.
[0027]
  An input shaft 41 a of the hydrostatic continuously variable transmission 41 is extended to the right through the front portion of the transmission case 9. A main transmission lever 46 for operating the hydrostatic continuously variable transmission 41 is disposed on the left side of the steering handle 14 and moves forward by a swing operation from the neutral to the front of the main transmission lever 46. The speed can be changed, and the reverse speed can be changed by a swing operation from neutral to backward.
[0028]
  As shown in FIG. 4, a hydraulic pump 42 driven by the extended end portion of the input shaft 41a of the hydrostatic continuously variable transmission 41 is connected to the right side surface of the mission case 9, and the mission case As shown in FIGS. 3 and 4, a torque generator 43 constituting a hydraulic power steering device interlocked with the handle shaft 14 a of the steering handle 14 and a working device for controlling the elevating cylinder 6 are disposed on the upper surface of 9. A control valve 44 for lifting operation is attached.
[0029]
  The transmission case 9 is also used as a hydraulic oil tank, and the lubricating oil in the transmission case 9 is taken out as hydraulic fluid through an oil filter 45 attached to the right side surface of the transmission case 9 so as to be hydrostatic. The pressure oil supplied from the hydraulic pump 42 to the transmission 41 and the hydraulic pump 42 is supplied to the torque generator 43, and then supplied to the elevating cylinder 6 through the control valve 44. The drain oil of the hydrostatic continuously variable transmission 41 is returned to the front axle case 9a communicating with the transmission case 9, and the drain oil from the control valve 44 is directly returned to the transmission case 9. .
[0030]
  As shown in FIGS. 5 and 6, in the transmission case 9, the main clutch 50 that intermittently transmits the output from the hydrostatic continuously variable transmission 41, and the output from the main clutch 50 are divided into high and low two stages. And a differential device 52 for transmitting the output from the sub-transmission device 51 to the left and right front wheels 1, and only the forward rotation power of the power branched from the traveling transmission system is installed. A one-way clutch 53 that transmits to the seedling planting device 4, a planting speed change mechanism 54 that changes the power from now on, a planting clutch 55 that intermittently transmits power to the seedling planting device 4, etc. Equipped.
[0031]
  The main clutch 50 employs a multi-plate type, and a drive-side boss member 58 rotates integrally with an input shaft 57 connected to an output shaft 41b of the hydrostatic continuously variable transmission 41 via a coupling 56. The driven drum 60 covering the driving boss member 58 is connected to and supported by the clutch output shaft 59 that is loosely fitted to the input shaft 57 so as to be integrally rotatable. 59 and the driven drum 60 are shifted with respect to the driving boss member 58, and the friction plates 61 interposed between the driving boss member 58 and the driven drum 60 are pressed or released from the driving side. The friction transmission of power from the boss member 58 to the driven drum 60 is configured to be interrupted, and the clutch output shaft 59 and the driven drum 60 are always pressed against the friction plate. It urged by (clutch engaging direction) the spring 62.
[0032]
  The main clutch 50 can be turned on and off only by pedal operation. In other words, the airframe stop pedal 25 provided at the right foot position of step 24 in the boarding operation unit 13 and the upper surface of the mission case 9 are penetratingly mounted so as to be rotatable around the vertical axis P perpendicular to the input shaft 57. A clutch operating shaft 63 is interlocked and connected, and a rotating arm 27 is attached to a pedal shaft 26 that rotates integrally with the machine body stop pedal 25. The rotating arm 27 and the clutch operating shaft 63 project outside the case. And the passive arm 63a provided on the clutch is linked to each other by the rod 28, and the clutch operating shaft 63 is rotated in the forward and reverse directions when the body stop pedal 25 is depressed and released. ing.
[0033]
  An eccentric cam 63b having a semicircular cross section formed by cutting away a part of the circumferential surface is formed at the front end of the clutch operating shaft 63 in the case, and this eccentric cam 63b is formed on the end surface of the clutch output shaft 59. Opposed. In the normal state in which the fuselage stop pedal 25 is not depressed, as shown in FIG. 5, the eccentric cam 63 b is in a posture in which the pressure against the clutch output shaft 59 is released, and this brings about an “on” state of the main clutch 50. It is. Further, when the fuselage stop pedal 25 is depressed, the edge portion of the eccentric cam 63b is displaced and pressed against the end face of the clutch output shaft 59, and the clutch output shaft 59 is moved against the urging by the spring 62, and the driven side When the drum 60 is displaced rightward in the figure, the main clutch 50 is switched to the “disengaged” state. In this clutch disengaged state, the friction between the edge portion of the eccentric cam 63 b and the end face of the clutch output shaft 59 gives resistance to the rotation of the clutch output shaft 59, and the clutch output shaft 59 rotates with the input shaft 57. Is to be prevented.
[0034]
  The auxiliary transmission 51 is of a gear shift type, and the transmission input shaft 64 is positioned in the axial direction in a state in which a large-diameter transmission gear 65 for high speed and a small-diameter transmission gear 66 for low speed rotate together. The transmission output shaft 67 is engaged with the large-diameter transmission gear 65 and the small-diameter gear portion 68 is engaged with the small-diameter gear portion 68. The low-speed position is engaged with the small-diameter transmission gear 66 and the large-diameter gear portion 69 is interlocked. A shift gear 70 that can be shifted to a neutral position that is not allowed to rotate is mounted so as to rotate integrally. The clutch output shaft 59 is mounted in a state where a small-diameter output gear 71 that meshes with and engages with the large-diameter transmission gear 65 and rotates and transmits the power is integrally rotated, and the transmission input shaft 64 is interlocked with the clutch output shaft 59 and decelerated. ing. An auxiliary transmission lever 47 for operating the auxiliary transmission 51 is arranged on the left side of the driver seat 15.
[0035]
  The differential device 52 that drives the left and right front wheels 1 is configured to be differentially lockable. A differential locking shift member 74 is attached to one of the differential shafts 72 extending to the left and right so that the differential shaft 72 can rotate integrally with the differential shaft 72 and can be shifted. As shown in FIG. The state of being separated from the differential case 73 is a normal differential lock release state, and the shift member 74 is shifted rightward in the drawing and engaged with the end face of the differential case 73 to bring about a differential lock state. The differential lock operating means for switching the differential device 52 between the differential lock state and the differential lock release state is configured such that the shift member 74 is biased by a spring (not shown) to the differential lock release position, and the rear left part of the foot of the riding operation unit 13 The diff lock pedal 48 provided on the vehicle is linked to the shift member 74, and the diff lock release state is maintained by keeping the foot away from the diff lock pedal 48 during normal driving, so that the vehicle body can be taken in and out of the field and the transport vehicle. The diff lock state can be brought about by depressing the diff lock pedal 48 with the left foot heel as needed, such as loading and unloading the aircraft on the cargo bed, and the left and right front wheels 1 can be driven at a constant speed.
[0036]
  The differential case 73 of the differential mechanism 52 has a gear integrally formed with an input gear 76 that meshes with a transmission output gear 75 that is splined to the transmission output shaft 67 and a main transmission shaft 77 for transmission to the rear wheel 2. An output gear 79 is attached to 78.
[0037]
  The one-way clutch 53 is provided so as to transmit only forward rotation of the rotation of the transmission input shaft 64 to the planting transmission system using the transmission input shaft 64 as a branch point from the traveling transmission system to the planting transmission system. ing.
[0038]
  The planting speed change mechanism 54 is mounted on the speed change output shaft 67 so as to be freely rotatable only relative to the output shaft 80 of the one-way clutch 53 via a gear 81. A group of driven gears 87 which are always engaged with and interlocked with the planting shift output shaft 86 which is mounted in a state of rotating integrally with the planting gear 83 and interlocked with the planting clutch 55 via bevel gears 84 and 85. Is mounted so as to be relatively rotatable, and a transmission ball 89 for interlockingly connecting the driven gear 87 to the planting transmission output shaft 86 by engaging with an engaging recess 88 formed in the center hole of each driven gear 87 is a planting transmission output. The structure is provided with an operation shaft 90 that is provided so as to rotate integrally with the shaft 86 and that selectively engages the transmission ball 89 with the engaging recess 88. In other words, the driven gear 87 is selectively coupled to the planting shift output shaft 86 so that the driven gear 87 used for transmission is changed to perform a shift of a plurality of stages (in the example, six stages). Has been.
[0039]
  As shown in FIGS. 7 to 9, the rear transmission case 10 for driving the rear wheels includes a lateral transmission case portion 10 </ b> A supported on the body frame 8 so as to be able to roll around the longitudinal axis X within a certain range, and its left and right sides. It is comprised from the deceleration case part 10B connected with each both ends. In the lateral transmission case portion 10 </ b> A, a lateral transmission shaft 93 that distributes the power from the main transmission shaft 77 extending rearward from the mission case 9 to the left and right is built in, and the lateral transmission shaft 93 and the main transmission shaft 77. Are linked together via bevel gears 91 and 92. Each reduction case portion 10B is equipped with an axle 2A that supports the rear wheel 2 and a reduction gear mechanism 94 that links the lateral transmission shaft 93 and the axle 2A with a reduced speed.
[0040]
  A transmission system for the rear wheel 2, specifically, a multi-plate type side clutch that separates the transmission to the rear wheels 2 separately between both ends of the lateral transmission shaft 93 and the reduction gear mechanisms 94. 96 is interposed. These side clutches 96 include a boss member 96A that is spline-fitted to the lateral transmission shaft 93 and rotates integrally, and is movable in the axial direction, and a driven drum 96B that is linked to the reduction gear mechanism 94, and includes a boss member 96A. A plurality of friction plates 96C are brought into pressure contact with each other by moving the fuselage laterally outward to engage the friction (with clutch), and release the frictional interlock (clutch disengagement) by moving the boss member 96A laterally inward of the fuselage. A clutch spring 96D that is distributed and attached to 96A and the driven drum 96B and moves and urges the boss member 96A toward the clutch engagement side is externally attached to the transmission shaft 93.
[0041]
  The reduction gear mechanism 94 is disposed on the lateral outer side of the driven drum 96B of the side clutch 96, and has a small-diameter first gear G1 that rotates integrally with the driven-side drum 96B, and a large-diameter second gear G2 that meshes with the first gear G1. And a third gear G3 having a small diameter and a wide width which is coaxial with the second gear G2 and rotates integrally therewith and a fourth gear G4 having a large diameter and a wide width which is connected to the axle 2A. Yes, by arranging the gear pair of the third gear G3 and the fourth gear G4 on the inner side of the fuselage so as to be pushed into the lower side of the side clutch 96, the reduction case 95 is suppressed from being widened laterally outward. Yes.
[0042]
  In addition, as shown in FIG. 8, an airframe stop brake 30 is provided between the right deceleration case portion 10B and the boss member 96A. The fuselage stop brake 30 presses the friction plate 31 that is externally attached to the outer periphery of the boss member 96A and the friction plate 32 that is engaged with the inner periphery of the speed reduction case portion 10B and stops the rotation. The member 96A and the lateral transmission shaft 93 that rotates integrally with the member 96A are braked, and the cup-shaped operation member 33 loosely fitted to the boss member 96A moves laterally outward (rightward in FIG. 8). As a result, the friction plates 31 and 32 are brought into pressure contact with each other.
[0043]
  The airframe stop brake 30 is a deceleration case.PartIt is operated by a brake operation shaft 34 that is rotatably mounted on the upper surface of 10B so as to be rotatable around the vertical axis P1. In other words, a shift fork 35 is attached to a portion of the brake operation shaft 34 that enters the case, and the shift fork 35 is disposed opposite to the end surface of the operation member 33, and the brake operation shaft 34 is rotated. The operating member 33 can be shifted via the shift fork 35 to brake the boss member 96A.
[0044]
  As shown in FIG. 7, the operation arm 34 a provided on the case protruding portion of the brake operation shaft 34 is linked to the machine body stop pedal 25 via the linkage rod 36, and the machine body stop pedal 25 is depressed. In accordance with the operation, the linkage rod 36 is pulled and displaced forward, and the airframe stop brake 30 is braked. When the airframe stop pedal 25 is released and returned to the original posture, the brake of the airframe stop brake 30 is released. It has become so. Here, since the fuselage stop pedal 25 is also linked to the main clutch 50 as described above, it functions as a main clutch / brake pedal. Thus, braking is applied by the subsequent depressing operation.
[0045]
  The linkage rod 36 is provided with a turnbuckle 36a, and the operation timing of the body stop brake 30 with respect to the main clutch 50 can be adjusted by adjusting the expansion and contraction of the turnbuckle 36a.
[0046]
  The operation structure of the side clutch 96 is configured as follows. That is, the clutch operating sleeve 102 that is disposed in abutment with the lateral transmission shaft 93 via the thrust collar 103 on the end surface of the boss member 96A is slidably loosely fitted, and the speed reduction case portion 10BA clutch operating shaft 104 is inserted through the upper surface of the clutch operating shaft 104 so as to be rotatable about the vertical axis P2, and an eccentric cam 105 formed at the end of the clutch operating shaft 104 in the case is disposed opposite to the end surface of the clutch operating sleeve 102. Thus, the side clutch 96 is turned on and off by the turning operation of the clutch operation shaft 104.
[0047]
  As for the left and right side clutch 96, only the one on the inside of the turn is automatically turned off based on the aircraft steering operation, and this side clutch automatic operation mechanism 106 is configured as follows. . That is, as shown in FIG. 7, the pitman arm 111 swingably driven left and right by the torque generator 43 constituting the power steering device and the knuckle arm 118 of each front wheel 1 are interlocked and connected via the tie rod 119. A steering link mechanism 110 is configured, and an operation fitting 111a provided continuously with the pitman arm 111 and a relay arm 113 provided so as to be swingable about a longitudinal axis Y at a lower portion in the vicinity of the front and rear of the airframe are pushed and pulled. 112, the left and right ends of the balance arm 115 connected to the upper end of the fulcrum shaft 114 of the relay arm 113, and the operation arms 104a connected to the case outer protrusions of the left and right clutch operation shafts 104 respectively connect the rods 116. It is linked and connected through. It should be noted that the rear end of the rod 116 and the operation arm 104a are elongated pin pins so that the operation arm 104a is swung by the forward displacement of the rod 116, and the operation arm 104a is not swung by the rearward displacement of the rod 116. It is linked.
[0048]
  Here, the connection hole 117 with the push-pull rod 112 formed on the operation fitting 111a provided continuously with the pitman arm 111 is formed as a long hole along the swinging direction of the operation fitting 111a, and the pitman arm 111 advances straight. The length of the linkage hole 117 is such that the swing of the pitman arm 111 is transmitted to the push-pull rod 112 only when it swings more than a set angle (for example, 30 °) from the posture, but the swing less than the set angle is not transmitted. Is set.
[0049]
  Therefore, when the left and right front wheels 1 are steered more than a set angle in order to make the airframe largely turn, the swing of the pitman arm 111 is transmitted to the balance arm 115 via the relay arm 113 and is pulled forward. Only one side clutch 96 linked to 116 is turned off. That is, only the side clutch 96 on the inner side of the turning is operated to turn, and the body turns by the three-wheel drive of the left and right front wheels 1 and the rear wheel 2 on the outer side of the turning. As the vehicle turns, the vehicle rotates following the ground contact, and the vehicle body is turned by the rear wheel 2 inside the turn without unduly roughening the field.
[0050]
  In this case, as shown in FIG. 10, when the front wheel 1 is steered to the maximum and the aircraft is turned U-turn, the maximum steering angle of the front wheel 1 is set to the planting width so that the center of the aircraft is in an adjacent planting state. (The number of planting strips), the front wheel tread, and the wheel base are set so as to facilitate the alignment operation after the U-turn turning at the shore.
[Brief description of the drawings]
[Fig. 1] Overall side view of a riding rice transplanter
[Figure 2] Overall plan view of the riding rice transplanter
[Fig. 3]Self-propelled aircraftFront side view
[Fig. 4]Self-propelled aircraftFront view
FIG. 5 is a sectional view showing a part of the transmission mechanism in the mission case.
FIG. 6 is a sectional view showing a part of a transmission mechanism in a mission case.
[Figure 7] Operation system diagram
FIG. 8 is a longitudinal rear view showing the right part of the rear transmission case.
FIG. 9 is a longitudinal rear view showing the left part of the rear transmission case.
FIG. 10 is a plan view showing a turning operation at the shore.
[Explanation of symbols]
  1 front wheel
  2 Rear wheels
  11 Engine
  13 Boarding operation
  25 Aircraft stop pedal
  30 Airframe stop brake
  41 Hydraulic continuously variable transmission
  43 Power steering device
  50 Main clutch
  96 side clutch
  106 Side clutch automatic operation mechanism

Claims (3)

The engine power is transmitted to a hydraulic continuously variable transmission, and the power of the hydraulic continuously variable transmission is configured to be transmitted to left and right front wheels that can be steered and to left and right rear wheels that cannot be steered .
Without a brake that brakes only the right rear wheel, without a brake that brakes only the left rear wheel, each has a friction side clutch corresponding to the left and right rear wheels ,
A side clutch automatic operation mechanism that allows the side clutch on the inside of the turn to be turned off only by the steering operation of the front wheel beyond the set reference angle,
A pedal that is provided with a fuselage stop pedal at the right foot portion of the boarding operation part, and that is configured such that the main clutch is operated only by the aircraft stop pedal and the vehicle stop brake is operated by braking, and only the main clutch is operated. Without
A riding-type rice transplanter configured such that the side clutch automatic operation mechanism and the main clutch is disengaged and the airframe stop brake is braked only by the airframe stop pedal are operated independently of each other .   The riding type rice transplanter according to claim 1, wherein a maximum steering angle of the front wheel is set so that the center of the aircraft body is in an adjacent planting state when the front wheel is steered to the maximum and makes a U-turn.   The riding type rice transplanter according to claim 1 or 2, further comprising a power steering device that steers the front wheel.

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