JP2011063137A - Riding type farm working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate operation of a transmission control lever in a riding type rice-planting machine including a hydrostatic continuously variable transmission (HST). <P>SOLUTION: A traveling mode is changed by changing a gear mesh of a traveling transmission 24 by operating the transmission control lever 54. The traveling transmission 24 uses the HST 41 and a gear group together. The HST 41 is controlled by an electric motor 122. The electric motor 122 is driven by a signal from a sensor device for detecting movement of a transmission pedal 62. When the transmission pedal 62 returns completely, an interlock shaft 165 retracts by the return rotation of a rotary shaft 109. Then, a clutch arm 159 rotates in a clutch disengaging direction, and a brake works lightly. The transmission control lever 54 can be operated without pedaling a brake pedal 100 by changing foot every time. Therefore, the riding type rice-planting machine has excellent usability. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a riding type farm working machine such as a riding type rice transplanter, and more particularly to a riding type farm working machine in which a traveling state is switched by a shift operation lever.

  For example, a riding rice transplanter has a planting mode (low-speed mode) set to a speed range for planting in a field, a high-speed mode set to a speed range for on-road driving, There are maneuvering control modes such as a toll mode and a reverse mode, and switching between these modes is performed by an operator operating a shift operation lever in the maneuvering area. That is, when the speed change lever is operated, the movable gear built in the travel transmission device slides, and the mode is switched by changing or releasing the meshing of the gear.

  On the other hand, a continuously variable transmission and a rotary steering handle (so-called round handle) are used for the traveling transmission, and this type of passenger rice transplanter can be operated with a feeling close to that of a passenger car. Therefore, it is excellent in operability both in the field work and on the road.

  There are two types of continuously variable transmissions: belt type (CVT) and hydrostatic type (HST). Belt type continuously variable transmissions reversely change the inner diameter of the drive pulley and the driven pulley (the diameter of the part where the belt abuts). As a result, the hydrostatic continuously variable transmission is continuously variable by rotating the output control shaft and changing the discharge amount of the drive pump. In any case, the control member of the continuously variable transmission moves in conjunction with the depression amount of the shift pedal.

  For example, in Patent Document 1, in a riding-type rice transplanter using a belt-type continuously variable transmission, a control member of the continuously variable transmission is moved by a transmission motor (electric motor) and the amount of depression of the transmission pedal (accelerator pedal) is described. Is detected by a transmission motor switch, and the belt-type continuously variable transmission is controlled by controlling the rotation of the transmission motor by the transmission motor switch.

JP 2004-284458 A

  Now, when changing the meshing of the gear by operating the speed change lever, whether the gear that is engaged is disengaged or the gear that is separated is engaged, the driving force must not be applied to the gear. Cannot switch to smooth.

  On the other hand, when the shift pedal is fully retracted, the output of the continuously variable transmission becomes minimum and the agricultural machine stops, but even in the stopped state, a slight torque acts on the output shaft of the continuously variable transmission, Even in the stopped state, a force to rotate the gear group of the traveling transmission device is applied. Therefore, it is difficult to change the meshing of the gears simply by stopping the agricultural machine, and even if it is attempted to move the shift operation lever, it will be caught in the middle.

  Therefore, even a travel transmission having a continuously variable transmission is provided with a main clutch (travel clutch), and the operation of the speed change operation lever (that is, switching of the travel mode) is performed with the main clutch disconnected. Conventionally, a system has been adopted in which the main clutch is disengaged when the brake pedal is depressed. However, although this method is superior in operability as compared with a method in which the main clutch is turned on and off by manual operation, there is an inconvenience that a foot must be switched from a shift pedal to a brake pedal.

  This invention is made | formed in view of such a present condition, and makes it a subject to improve the operativity of a riding type farm working machine.

  The present invention has a multifaceted spread. The invention of claim 1 constitutes a superordinate concept. This invention relates to a traveling vehicle body supported by wheels, an engine, a traveling transmission device for shifting the power of the engine, and a shifting operation that can be manually operated by an operator in a seated state. A lever, a foot-operated speed change pedal and a brake pedal that can be operated in a seated state are provided, and the traveling speed change device has a transmission case in which a gear group for speed change, a clutch, and a brake are incorporated. In the riding type agricultural work machine, wherein the shift operation lever can be operated when the main clutch is disengaged, the shift pedal, the main clutch, and the brake return to a traveling stop state in which the shift pedal is not depressed. And the main clutch is disengaged and the brakes work together.

  The invention of claim 2 is a preferred embodiment of claim 1 in which the main clutch is disengaged when the shift pedal, the main clutch, and the brake return to a travel stop state in which the shift pedal is not depressed. Are linked so that the brakes work.

  According to a third aspect of the present invention, the invention according to the second aspect of the present invention is preferably embodied. In the present invention, the transmission includes a continuously variable transmission to which power from an engine is transmitted. The output of the machine is transmitted to the gear group for transmission through the main clutch, and the continuously variable transmission is powered by an actuator driven by sensor means for detecting the movement of the shift pedal. The main clutch and the brake are operated in conjunction with a member that is controlled and moved by the actuator.

  According to a fourth aspect of the present invention, the invention of the second or third aspect is more preferably embodied. In the present invention, the brake can be operated by depressing a brake pedal, and the brake works in conjunction with the shift pedal. It is allowed to further depress the brake pedal.

  The invention of claim 5 further embodies the invention of claim 3 or 4, and in this invention, the sensor device is composed of an acceleration sensor and a deceleration sensor, both of which are The two sensors rotate together with a rotating shaft driven by an actuator and are biased by spring means so that they are held at neutral positions in an OFF state and are freely operated. When one of the two is turned ON and the rotating shaft stops, both sensors are set to return to the neutral position and turn OFF, and further, the main clutch is disengaged in conjunction with the movement of the rotating shaft. The braking operation is performed.

  The invention of claim 6 also embodies claim 3 or claim 4, and in this invention, the sensor means is a potentiometer, while the actuator is an electric motor and is disposed at a location in front of the mission case. Further, an output control arm for controlling the continuously variable transmission, a clutch arm for controlling the on / off of the main clutch, and a brake arm for controlling the brake can be horizontally rotated on the upper surface of the transmission case. The clutch arm and the brake arm are rotated together by an electric motor.

  In the present invention, the main clutch is disengaged when the traveling of the agricultural machine is stopped by turning the shift pedal back, so that the operator operates the shift operation lever without stepping or operating the clutch lever by hand. Since the mode can be switched, the shift operation lever can be easily switched. As a result, the operability of the agricultural machine can be significantly improved and the burden on the operator can be reduced.

  If a structure in which the main clutch is disengaged and the brake is effective when the shift pedal is completely returned as in claim 2 is employed, there is an advantage that the farm work machine can be stopped reliably and safety can be ensured.

  As described above, when a continuously variable transmission is incorporated in a traveling transmission, there is an advantage that a traveling feeling like a passenger car can be obtained, and when the continuously variable transmission is dynamically controlled by an actuator, There is an advantage that reaction force can be prevented from acting on the operator via the shift pedal. When the invention according to claim 3 is adopted, since the member driven by the actuator that dynamically controls the continuously variable transmission also serves as the operation member of the main clutch and the brake, an actuator for controlling the continuously variable transmission is provided. There is an advantage that the cost can be reduced by suppressing the number of members while enjoying the advantages of the provision.

  When operating agricultural machines, the brake pedal is often depressed for safety. And if the structure of Claim 4 is employ | adopted, since a main clutch can be cut | disconnected by the return of a speed change pedal, accepting pushing down a brake pedal strongly, it can be said that it is highly realistic.

  The sensor means for detecting the movement of the shift pedal to drive the actuator can be embodied in various ways. However, if a combination of ON / OFF type sensors is used as in claim 5, for example, an inexpensive limit switch (microswitch) is used. It can be used to contribute to cost reduction. In the fifth aspect of the present invention, the main clutch and the brake are operated by the rotation shaft to which the sensor is attached. Therefore, it can be said that the structure can be simplified and the cost can be further reduced.

  On the other hand, the invention of claim 6 is characterized in that the output control arm, the clutch arm, and the brake arm are arranged on the upper surface portion of the transmission case. For example, even when the engine is mounted on the front part of the traveling vehicle body, the output control arm, the clutch arm, and the brake arm can be arranged without any interference without interfering with other members. . Therefore, the invention of claim 6 can suppress the design effort related to the arrangement of the members, and is particularly suitable when the engine is arranged in front of the transmission case.

It is a left view of the rice transplanter which concerns on 1st Embodiment. It is a top view of a rice transplanter. It is a perspective view in the state where a vehicle body cover was separated. (A) is a partial side view in the state which isolate | separated the vehicle body cover, (B) is a partial side view which shows the relationship between a mission case and a power steering unit. It is the perspective view seen from the left rear in the state which omitted some members so that a framework might be understood. It is the perspective view seen from the right back in the state where a member was partially omitted so that a framework might be understood. It is a partial top view. It is a top view of the principal part. It is a transmission system diagram. (A) is a top view of a mission case, (B) is a top view which displayed the gear group inside a mission case. It is the perspective view which looked at the gear group from the front. It is a top view which shows a power control system. (A) is an overall perspective view of the power control system, (B) is a perspective view showing the mounting structure of the speed change lever, and (C) is a plan view of the speed change lever guide hole. (A) is a perspective view showing a power control system, (B) is a partially separated plan view of a control mechanism of HST. (A) is the perspective view seen from the bottom in order to show a power control system, (B) is a side view which shows the attachment structure of a clutch rod. It is a figure which shows the front part and power steering unit of a mission case, (A) is the perspective view seen from the top, (B) is the perspective view seen from the side. (A) And (B) is a perspective view which shows a traveling control system, (C) is a figure which shows the function of a sensor apparatus. It is a perspective view which shows the attachment structure of a brake pedal. It is a perspective view of a travel control unit. It is a perspective view of 2nd Embodiment. It is a perspective view of 2nd Embodiment. The perspective view of the traveling vehicle body which concerns on 3rd Embodiment, (A) is a figure which shows an external appearance, (B) is a perspective view which shows a framework. It is a perspective view of the traveling vehicle body which displayed the framework and the drive system. It is a top view which shows a power system. It is a transmission system diagram. (A) is a top view of the principal part, (B) is a perspective view showing the mounting structure of the speed change lever, and (C) is a plan view of the speed change lever guide hole. It is the perspective view of a mission case, (A) is the figure seen from the side, (B) is the figure seen from the back. It is a perspective view which shows the control mechanism of a travel transmission, (A) is a general view, (B) is a partial figure. (A) is a figure which shows a shift pedal and its vicinity, (B) is a side view of the brake pedal and the member attached to this. It is the perspective view which mainly shows the attachment structure of a brake pedal, (A) is the figure seen from the top, (B) is the figure seen from the bottom. It is a top view of the principal part. (A) is an exploded perspective view showing the control mechanism, (B) is a perspective view showing a part of the traveling transmission. It is a figure which shows a control mechanism, (A) is a top view, (B) is the perspective view seen from back lower part, (C) is a separated top view. It is a figure which shows a trunnion rod control unit, (A) is a perspective view of the state which displayed the steering unit, (B) is a perspective view of the state which abbreviate | omitted the steering unit. It is a figure which shows a motor unit, (A) is the perspective view seen from the diagonal side, (B) is a side view in the state which removed the case.

  Next, an embodiment 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 words “front and rear” and “left and right” are used to specify the direction, but these words are based on the direction of the operator seated in the forward direction as specified in the claims. I have to.

(1). Outline of Rice Transplanter According to First Embodiment First, an outline of a rice transplanter (4-jou rice transplanter) according to the first embodiment will be described mainly with reference to FIGS. As can be easily understood from FIGS. 1 and 2, the rice transplanter has a traveling vehicle body 1 and a seedling planting device 2 as main parts, and the traveling vehicle body 1 is supported by left and right front wheels 3 and rear wheels 4. ing. The seedling planting device 2 has four rotary planting devices 5, a seedling mounting table 6 having four belts, a float 7 for maintaining a horizontal posture, a leveling rotor 8 for leveling a headland, and the like. Yes.

  The traveling vehicle body 1 has a maneuvering area 9 in which a seat 10 with a backrest on which a driver sits and a maneuvering handle 11 arranged in front of the seat 10 are arranged. The seat 10 and the steering handle 11 are disposed at the left and right intermediate positions of the traveling vehicle body 1. The steering handle 11 is provided in a steering mechanism portion 14 covered with a front and rear split bonnets 12 and 13. In addition, preliminary seedling stands 15 are provided on the left and right sides in front of the seat 10, and a fertilizer application device 16 is provided behind the seat 10.

  For example, as can be understood from FIGS. 5 and 6, the traveling vehicle body 1 includes a left and right square steel pipe side frame 18 extending in the front-rear direction, a front frame 19 in which the left and right side frames 18 are connected at a portion near the front end, It has a left and right longitudinal rear frame 20 connected to the rear end of the side frame 18. A vehicle body frame (chassis) constituting a part of the framework of the traveling vehicle body 1 is configured with the side frame 18, the front frame 19 and the rear frame 20 as main members.

  For example, as shown in FIG. 5, left and right side frames 18 are fixed to each other by an outward branch frame 21 that is horizontally long and protrudes outward, and the spare seedling stand 15 is attached to the two outward branch frames 21. It is attached. Further, auxiliary frames 22 extending in the front-rear direction are arranged in parallel on the left and right outer sides of the side frame 18 in plan view. The auxiliary frame 22 is welded to the outward branch frame 21.

  The side frame 18 is bent so that a substantially front half portion is in a substantially horizontal posture and a rear half portion is in a backward inclined posture with a front and rear intermediate portion as a boundary, and a seat 10 is disposed substantially above the bent portion. ing. Further, as can be understood from FIGS. 4 and 5, for example, the engine 23 is disposed in a portion of the side frame 18 positioned below the inclined portion in a side view, and is lower than the side frame 18 in front of the engine 23. A mission case 25 that constitutes the traveling transmission device 24 is disposed at the position.

  The engine 23 is disposed in a posture in which the crankshaft extends in the left-right direction and the cylinder bore in a posture in which the crankshaft is tilted rearward. Power is transmitted to the traveling transmission device 24 by a pulley and a belt 27. A front axle device 28 is attached to the left and right side surfaces of the front portion of the mission case 25, and the front wheel 3 is rotatably supported by the front axle device 28.

  As can be understood from FIG. 7, the engine 23 and the seat 10 are generally arranged at the left and right intermediate portions of the traveling vehicle body 1. As shown in FIG. 1, a fuel tank 29 is disposed between the seat 10 and the engine 23. The left and right sides and the rear side of the seat 10 are shoulder portions on which a person can get on and off, and a fertilizer application device 16 is disposed at a rear portion of the shoulder portion.

  A rear axle case 30 is disposed behind the engine 23, and the rear wheel 4 is fixed to a rear axle 31 that protrudes left and right from the rear axle case 30. Note that an auxiliary wheel may be attached to the rear wheel 4 in a deep mud field.

  The rear axle case 30 and the rear frame 20 are connected by two right and left rear columns 32. For example, as can be understood from FIG. 1, a top link 33 is connected to the rear column 32 so as to rotate up and down around its front end, while the left and right rear columns 32 are provided with parallel members extending in the front-rear direction. A lower link 34 as a main material is connected so as to rotate around its front end, and a hitch (not shown) is connected to the rear ends of the top link 33 and the lower link 34 so as to be relatively rotatable. The planting device 2 is attached to the hitch. For example, as can be understood from FIG. 1, a hydraulic cylinder 36 is connected to the lower link 34 and the rear frame 20 so as to be relatively rotatable, and when the hydraulic cylinder 36 is expanded and contracted, the seedling planting device 2 moves up and down.

  As shown in FIGS. 3 and 4, a portion of the traveling vehicle body 1 on which a person is placed is covered with a vehicle body cover 37. Accordingly, the vehicle body cover 37 has a stepped shape, and the floor of the control area 9 is constituted by the vehicle body cover 37. Note that the vehicle body cover 37 is divided into the upper and lower parts, but may be an integral structure. A lower part of the body cover 37 is supported by the side frame 18, the auxiliary frame 22, and the like.

(2). Outline of Power System / Control System For example, as can be understood from FIG. 8, the mission case 25 has a hollow structure in which two main members on the left and right are roughly overlapped and fastened with a bolt group. Left and right convex portions 25a and 25b are provided on the front side portion of the mission case 25, and a front axle device 28 is attached to the convex portions 25a and 25b. The projecting dimension of the left projecting portion 25a is larger than the projecting dimension of the right projecting portion 25b. This is because the differential mechanism is arranged inside the left projecting portion 25a. The upper end of the front axle device 28 is attached to the side frame 18 via a bracket.

  For example, as can be easily understood from FIG. 1, the transmission case 25 and the rear axle case 30 are connected by a hollow rectangular joint member 40. The front part of the engine 23 is supported by a joint member 40 via a front bracket material, and the rear part of the engine 23 is supported by a rear axle case 30 via a rear bracket material.

  A hydrostatic continuously variable transmission (hereinafter referred to as “HST”) 41, which is an example of a continuously variable transmission, is attached to the left side surface of the rear portion of the transmission case 25 with its input shaft 42 in a horizontally long posture. The power from the engine 23 is first transmitted to the input shaft 42 of the HST 41 by the belt 27. Then, the front wheel 3 and the rear wheel 4 are driven in synchronism with the power from the traveling transmission device 24, and are driven in conjunction with the rotation of the planting device 2 and the fertilizer application 16 wheels 3 and 4.

  For example, as can be understood from FIG. 10, the traveling drive shaft 43 extends rearward from the rear surface of the transmission case 25, and the driving power of the rear wheels 4 is transmitted to the inside of the rear axle case 30 via the traveling drive shaft 43. Yes. The leveling rotor 8 shown in FIG. 1 is driven by a leveling output shaft provided on the rear surface portion of the rear axle case 30.

  For example, as shown in FIG. 6, a power steering unit 44 is disposed at the left and right intermediate part of the steering mechanism unit 14, and a hollow handle post inclined backward at a gentle angle in a side view is disposed on the upper surface of the power steering unit 44. 45 is fixed. A handle shaft 46 is rotatably disposed inside the handle post 45, and the steering handle 11 is fixed to the upper end of the handle shaft 46.

  As shown in FIG. 4B, the power steering unit 44 has the above-described steering hydraulic motor 47 constituting the upper portion, and a steering gear box 48 fixed to the lower end of the steering hydraulic motor 47. A handle post 45 is attached to the upper end of the steering hydraulic motor 47. The handle shaft 46 is connected to the rotation shaft of the steering hydraulic motor 47. The steering gear box 48 is disposed so as to extend rearward from the steering hydraulic motor 47. The steering gear box 48 is fixed to the front frame 19 via a front bracket 49, and is also bolted to the front end of the transmission case 25. It is fixed with. Therefore, in this embodiment, the steering gear box 48 of the power steering unit 44 also serves as the structural material of the traveling vehicle body 1.

  A rotatable steering arm 50 is exposed from the lower end of the steering gear box 48, and two left and right steering rods 51 shown in FIG. On the other hand, for example, as shown in FIG. 5, the front axle device 28 has a front wheel gear case 52 that can turn horizontally, and the front wheel 3 is fixed to the front axle of the front wheel gear case 52. A steering rod 51 is connected to an arm portion provided in the front wheel gear case 52. Accordingly, when the steering handle 11 is rotated, the left and right front wheels 3 are synchronously turned horizontally in the same direction via the power steering unit 44, whereby the traveling direction of the traveling vehicle body 1 is changed.

  For example, as shown in FIG. 5, a plate-like front plate 53 is fixed to the upper portion of the handle post 45, and switches and keys are provided on a front panel (not shown) attached to the front plate 53. (A display or the like can also be provided.) A manual speed change operation lever 54 for switching the traveling mode is arranged on the left side surface portion of the handle post 45 so as to rotate in the front-rear direction. The front plate 53 has a guide hole 55 that holds the position (rotation posture) of the speed change lever 54.

(3) Structure of Traveling Transmission Device Next, the shifting mode of the traveling transmission device 24 will be described mainly based on FIG. 9 (power system diagram). The input shaft 42 of the HST 41 is always rotating during operation of the engine 23, and a general-purpose hydraulic pump 58 driven by the input shaft 42 is attached to the right side surface of the mission case 25. The lifting hydraulic cylinder 36 and the power steering unit 44 are driven by pressure oil generated by a general-purpose hydraulic pump 58.

  The HST 41 has a traveling hydraulic pump 59 and a traveling hydraulic motor 60, the traveling hydraulic pump 59 is driven by the input shaft 42, the traveling hydraulic motor 60 is driven by the pressure oil sent from the traveling hydraulic motor 59, and The hydraulic oil discharge amount of the traveling hydraulic pump 59 is adjusted by the rotation amount of the movable swash plate (flow rate control plate), and as a result, the output of the traveling hydraulic motor 60 can be changed steplessly. For example, as shown in FIG. 8, in the HST 41, an output control shaft 61 for rotating the movable swash plate protrudes upward. Although details will be described later, the output control shaft 61 rotates based on, for example, the movement of the shift pedal 62 displayed in FIG.

  In the present embodiment, the HST 41 and the planetary gear mechanism 63 are combined, and the traveling hydraulic pump 59 adjusts the ratio at which the rotation of the first gear 64 fixed to the input shaft 42 is transmitted to the planetary gear mechanism 63 (that is, By rotating the output shaft 65 of the HST 41 forward or backward with the stationary state as the boundary, the rotation of the first rotation shaft 66 that is the output shaft of the planetary gear mechanism 63 is changed steplessly from zero to the maximum value. it can.

  A hollow second rotating shaft 67 is fitted on the first rotating shaft 66 so as to be slidable and relatively rotatable. The rotation of the first rotating shaft 66 is rotated through a main clutch (traveling clutch) 68 in the second rotation. It is transmitted to the shaft 67. A third rotating shaft 69 is disposed in parallel with the first rotating shaft 66 and the second rotating shaft 67 in front of the first rotating shaft 66 and the second rotating shaft 67. A group of main gears 70 is fixed to the second rotating shaft 67, while a group of driven gears 71 is slidably attached to the third rotating shaft 69. Engagement with the group changes. The reverse drive is performed by a back idler system in which a gear (not shown) fixed to the second rotating shaft 67 is driven to drive a gear rotating on the input shaft 42. Reference numeral 73 indicates a state in which the gear 71 is slid. When the reverse gear 73 provided on the third shaft 69 slides, the traveling vehicle body 1 enters the reverse mode. The third rotating shaft 69 is provided with a multi-plate brake (parking brake) 74 having a sliding friction plate.

  The power of the third rotating shaft 69 is transmitted to the differential shaft 77 via gears 75 and 76. The differential shaft 77 has a hollow structure and a differential case 78, and the differential case 78 rotates integrally with the differential shaft 77. Further, the differential shaft 77 is fitted to the right front wheel drive shaft 79 from the outside. A left front wheel drive shaft 80 is arranged concentrically with the right front wheel drive shaft 79, and the rotation of the differential shaft 77 is transmitted to the left front wheel drive shaft 80 via a differential gear built in the differential case 78. The right front wheel drive shaft 79 is provided with a differential lock device 82. When the differential lock device 82 is operated, the differential state of the left and right front wheels is released, and the left and right front wheel drive shafts 79 and 80 rotate in complete synchronization.

  A bevel gear 83 is attached to the left end portion of the third rotation shaft 69, and the power of the third rotation shaft 69 is transmitted to the rear wheel output shaft 84 by the pair of bevel gears 83. A travel drive shaft 43 is connected to the rear wheel output shaft 84 via a universal joint.

  A left and right longitudinal fourth rotary shaft 85 is pivotally supported in a part of the transmission case 25 behind the input shaft 42, and the second rotary shaft 67 is rotated by the main driving gear 86, the idle gear 87 and the driven gear 88. This is transmitted to the fourth rotation shaft 85. The idle gear 87 is fitted to the input shaft 42 so as to be relatively rotatable (therefore, the input shaft 42 is also used as a support shaft of the idle gear 87).

  A work power output unit 89 that protrudes into the right end portion of the fourth rotating shaft 85 projects from the rear side of the right side surface of the mission case 25. The work power output unit 89 is supported by a longitudinal work power output shaft 90 extending in the front-rear direction, and the rotation of the fourth rotating shaft 85 is transmitted to the work power output shaft 90 through a pair of bevel gears 91. An intermediate shaft 92 is connected to the work power output shaft 90 through a universal joint.

  As shown in FIG. 6, an inter-stock case 93 constituting an inter-stock adjustment device is disposed in the vicinity of the right end portion of the rear axle case 30. The intermediate shaft 92 displayed in FIG. 9 is input into the inter-stock case 93. A planting drive shaft (PTO shaft) 94 projects from the rear surface of the inter-case 93, and a fertilization drive shaft 95 projects from the upper surface of the inter-case 93.

  In FIG. 9, the left and right front wheel drive shafts 79 and 80 are displayed in front of the third rotation shaft 69, but as can be understood from FIG. 11, for example, the left and right front wheel drive shafts 79 and 80 are slightly different from the third rotation shaft 69. The front side is arranged below. In this way, the travel transmission device 24 can be made compact by arranging the rotation shafts in a three-dimensional manner.

(4) Shift control system For example, as shown in FIG. 8, a brake pedal 100 and a shift pedal 62 are arranged side by side on the right side of the handle post 45 in the floor of the control area 9. To be exact, both are arranged so that the brake pedal 100 is on the left and the shift pedal 62 is on the right.

  As shown in FIGS. 12 and 13, the shift pedal 62 is attached to the outward branch frame 21 of the right side frame 18 via the pedal hinge 101 so as to turn forward and turn around its rear end. For example, as shown in FIG. 12, a left and right first bearing cylinder 102 penetrates through the right side frame 18 at a position ahead of the center of rotation of the speed change pedal 62, and this first bearing cylinder 102. The first control rotary shaft 103 is rotatably inserted into the first control rotary shaft 103. The left and right end portions of the first control rotating shaft 103 are exposed to the outside of the first bearing cylinder 102.

  Further, a bell crank lever 104 having two rearwardly facing arm portions, diagonally upward and diagonally downward, is fixed to the right end portion of the first control rotating shaft 103, and the diagonally downward arm portion of the bell crank lever 104 is pulled. While being pulled backward by the first spring 105 of the formula, the diagonally upward arm portion of the bell crank lever 104 is connected to the speed change pedal 62 via the swing member 106. Accordingly, the shift pedal 62 is rotated so that the front end is directed downward when the driver depresses, and the shift pedal 62 is rotated back so that the front end is raised by the elastic force of the first spring 105 when the driver lifts his / her foot. To do.

  For example, as shown well in FIG. 15, a drive arm 107 extending substantially forward is fixed to the left end portion of the first control rotation shaft 103. On the other hand, a left and right second bearing cylinder 108 is disposed on the left side of the first bearing cylinder 102 and in front of the handle shaft 46, and the second control rotating shaft 109 is disposed on the second bearing cylinder 108. Is rotatably fitted. The third control rotation shaft 109 corresponds to the rotation shaft recited in the claims.

  As shown in FIG. 14, a forward bracket 110 is welded to the second bearing cylinder 108, and the forward bracket 110 is fastened to the front bracket 49 with bolts. The second control rotating shaft 109 is exposed on the right side of the second bearing cylinder 108, and the sensor case 112 is fixed to the right exposed portion via the sensor bracket 111. A driven arm 113 is rotatably attached to the right end portion of the second control rotation shaft 109. As shown in FIG. 15, a long hole 114 is formed in the driven arm 113, and a pin 115 projecting sideways on the drive arm 107 is slidably fitted in the long hole 114. Accordingly, when the first control rotating shaft 103 rotates by the rotation of the shift pedal 62, the driven arm 113 rotates in conjunction with the drive arm 107.

  As schematically shown in FIG. 17C, in the sensor case 112, two limit switches (sensor devices) including an acceleration detection limit switch 116a and a deceleration detection limit switch 116b are provided as an example of a sensor. The contactor is arranged in a state of facing the base (dog portion) of the driven arm 113. The two limit switches 116 a and 116 b are attached to the sensor case 112 in a state where they can be relatively rotated by a slight angle around the axis of the second control rotation shaft 109. Further, the two limit switches 116a and 116b are urged by two push springs 117 so as to be held in a neutral position where they do not come into contact with the driven arm 113 and to become free.

  For example, as shown in FIGS. 17 and 19, a support piece 118 is provided at the left end of the forward bracket 110 fixed to the front bracket 49, and a support plate 119 that is longitudinally long in plan view is provided on the support piece 118. It is fixed via a rod 120. A fan-shaped gear 121 having a large number of teeth formed on the outer periphery is rotatably attached to the support plate 119, and an electric motor 122 is fixed to the support plate 119. The sector gear 121 is fixed to the left end portion of the second control rotation shaft 109. The gear teeth are exposed backwards. On the other hand, the electric motor 122 is provided with a gear that meshes with the teeth of the sector gear 121. It is also possible to use a circular gear instead of the sector gear 121.

  For example, as shown in FIG. 15, an HST control rod 125 is connected to a part of the base portion of the sector gear 121 that is somewhat distant from the rotation center through a joint, and the HST control rod 125 is directed toward the HST 41. Extending backwards.

  On the other hand, as shown in FIGS. 8, 12, and 14, for example, an output control arm 126 that extends toward the upper side of the transmission case 25 in a cantilevered posture is fastened and fixed to the output control shaft 61 of the HST 41. An HST control rod 125 is connected to the tip of the output control arm 126 by a pin so as to be relatively rotatable. Accordingly, when the electric motor 122 is rotated forward and backward, the sector gear 121 is rotated. Then, the HST control rod 125 is pushed and pulled substantially in the front-rear direction, and accordingly, the output control arm 126 is rotated and the output of the HST 41 is output. Change. The HST control rod 125 is a composite type having a nut, and the length can be finely adjusted.

  For example, the output control arm 126 is clearly shown in FIG. When the output control arm 126 rotates clockwise in plan view, the output of the HST 41 increases. A guide pin 127 protrudes upward from a portion of the output control arm 126 between the front end and the base end. The throttle bracket 128 is fitted into the guide pin 127, and the rear end of the throttle bracket 128 is connected to the output control arm 126. The rear end face is locked.

  In the throttle bracket 128, the hole into which the guide pin 127 is fitted is a long hole 128a. One end of a throttle wire 130 is attached to the front end of the throttle bracket 128 via a second spring 129, and the throttle wire 130 is inserted into a tube (cable tube) 130a having one end fixed to the intermediate bracket 131. . The other end of the throttle wire 130 is attached to a throttle lever (not shown) of the engine 23. Therefore, when the output control arm 126 rotates clockwise, the throttle wire 130 is pulled and the output of the engine 23 increases.

  As shown in FIG. 16, the intermediate bracket 131 is generally U-shaped in plan view, and its rear end is fixed to the transmission case 25 with a bolt, and its front end is the lower end of the power steering unit 44 (gear case). ) Through auxiliary support columns 132.

  As shown in FIG. 14B, a support pin 133 protrudes upward at the tip (free end) of the output control arm 126, and on the other hand, the tip of the HST control rod 125 fits into the support pin 133. A U-shaped holder 134 in a plan view is fixed, and the holder 134 is held by a support pin 133 so that it cannot be removed.

  The empty space of the holder 134 is a long hole 136, so that the support pin 133 and the holder 134 can be moved relative to each other, and the rear end of the HST control rod 125 is in contact with the output control arm 126. Further, the third spring 137 biases the HST control rod 125 so that the rear end of the HST control rod 125 contacts the output control arm 126. Accordingly, the output control arm 126 is pushed and rotated by the HST control rod 125, and only the HST control rod 125 is opposed to the third spring 137 in a state where the output control arm 126 is completely rotated to the output zero posture. It can be retracted by some dimension.

  As described above, when the output control arm 126 rotates in the speed increasing direction, the output of the engine 23 increases, and when the output control arm 126 rotates in the deceleration direction, the engine 23 decreases. The maximum output of the engine 23 is limited. Therefore, the second spring 129 is provided so that the rotation of the output control arm 126 is not hindered even when the throttle lever of the engine 23 is fully rotated. Further, since the throttle bracket 128 is fitted into the guide pin 127 through the elongated hole 128a, the output control arm 126 can further return and rotate with the output of the engine 23 fully throttled.

  As can be understood from FIG. 17C, when the shift pedal 62 is depressed, the driven arm 113 rotates in the speed increasing direction (F1 direction), and then the base end portion (dog portion) of the driven arm 113 is used for speed increasing. When the limit switch 116a is turned ON, the electric motor 122 rotates in the forward direction, and the second control rotating shaft 109 and the sector gear 121 rotate in the forward direction, whereby the HST 41 is accelerated. In the initial rotation of the driven arm 113, the two limit switches 116a and 116b do not rotate. When the driven arm 113 rotates against the second spring 117 and hits the acceleration limit switch 116a, both limit switches 116a. 116b rotate together with the sensor case 112 and the second control rotating shaft 109.

  Since the acceleration limit switch 116a is kept ON while the operator continues to step on the shift pedal 62, the HST 41 continues to increase (that is, the traveling vehicle body 1 continues to accelerate). When the operator stops depressing the speed change pedal 62, both limit switches 116a and 116b are rotated by a slight angle with respect to the sensor case 112 so as to return to the neutral position by the pressing action of the spring 117. 113 is removed from the speed limit switch 116a, and the speed limit switch 116 is turned OFF.

  When the operator stops the depression of the shift pedal 62 and keeps the state, the electric motor 122 does not rotate, so the HST 41 is kept in the set state, and the traveling vehicle body 1 travels at a constant speed. When the operator releases the depression of the shift pedal 62, the driven arm 113 rotates in the deceleration direction (F2 direction in FIG. 17C) and the deceleration limit switch 116b is turned on. The HST 41 is decelerated. If the shift pedal 62 is returned and stopped in the middle of rotation, the reverse rotation of the electric motor 122 is also stopped, and the vehicle speed is kept constant.

  When the shift pedal 62 is fully returned, the driven arm 113 returns to the original position (original posture), and the second control rotary shaft 109 and the sector gear 121 are completely reversed by the electric motor 122. In this state, both limit switches 116 a and 116 b are in a neutral state where they are not in contact with the driven arm 113. Then, as described with reference to FIG. 14, since the HST control rod 120 is further retracted after the output control arm 126 of the HST 41 has fully retracted to the output zero posture, the second control rotary shaft is further decelerated after the HST 41 has completely decelerated. 109 reverses by some angle.

  Thus, the movement of the shift pedal 62 is transmitted to the output control shaft 61 via the electric motor 122. The output control of the HST 41 is accompanied by a resistance. If the output control of the HST 41 is directly performed by the driver's stepping force, a large stepping resistance acts on the driver's foot, and the burden on the driver increases. However, when the HST 41 is controlled by the electric motor 122 as in the present embodiment, the burden on the driver can be reduced.

(5) Travel mode switching mechanism As described above, the travel mode is switched by rotating the shift operation lever 54 back and forth. In the present embodiment, the mode is switched to four states of a high speed travel (road travel) mode, a planting travel (low speed travel) mode, a neutral position that has been stopped (neutral), and a reverse mode (the seedling mode is changed as in the third embodiment). It is also possible to provide it.)

  On the other hand, as shown in FIG. 11 and FIG. 12, the sliding operation of the gear group is performed by sliding the left and right horizontally long shifting operation shaft 139 attached to the mission case 25 in the axial direction. The speed change operation shaft 139 has a built-in part inside the mission case 25 and an exposed part protruding outside the mission case 25, and a shifter of a gear group is engaged with the built-in part.

  On the other hand, for example, as shown in FIG. 13, a vertically long rod 142 is connected to the speed change lever 54 via a bracket 140 and a crank lever 141, and the vicinity of the lower end of the lengthwise rod 142 and the tip of the speed change operation shaft 139. A hollow intermediate shaft 144 that is long in the longitudinal direction is rotatably disposed in the vicinity thereof, and a laterally long arm portion 144a connected to the longitudinal rod 142 is provided at the front end of the intermediate shaft 144, and at the rear end of the intermediate shaft 144 A downward arm portion 144b engaged with the speed change operation shaft 139 is provided. As shown in FIG. 16, the intermediate shaft 144 is rotatably attached to the intermediate bracket 131 described above.

  When the shift operation lever 54 is rotated back and forth, the shift operation shaft 139 slides through the vertical movement of the longitudinal rod 142 and the rotation of the intermediate shaft 144. Then, a group of driven gears (movable gears) 71 and 73 shown in FIG. Shifts and the meshing relationship changes.

  Now, when changing the meshing of the gear by operating the speed change lever 54, it is not in a state where the driving force is not acting on the gear, even if the meshing gear is disengaged or the separated gear is meshed. Can not switch to and smooth.

  On the other hand, when the shift pedal 62 is fully returned, the output of the HST 41 becomes minimum and the traveling vehicle body 1 stops. However, a slight torque is applied to the output shaft 65 of the HST 41 even in the stopped state. Even if it exists, the force which tries to rotate this acts on the gear group. Accordingly, it is difficult to change the meshing of the gears when the traveling vehicle body 1 is merely stopped, and even if the shift operation lever 54 is moved, it is grasped midway.

  Therefore, conventionally, even the travel transmission 24 having the HST 41 is provided with the main clutch 68, and the operation of the speed change operation lever 54 (that is, switching of the travel mode) is performed with the main clutch 68 disconnected. Conventionally, a system in which the main clutch 68 is disengaged when the brake pedal 100 is depressed is employed. However, although this method is superior in operability as compared with a method in which the main clutch 68 is turned on and off by manual operation, there is an inconvenience that the foot must be switched from the shift pedal 62 to the brake pedal 100. The present invention takes this point into consideration, and a specific example will be described below.

(6) Relationship between main clutch, shift pedal and brake pedal The brake pedal 100 is arranged on the left side of the shift pedal 62. For example, as shown in FIG. It is attached to a left and right longitudinal support cylinder 147 disposed slightly forward. The support cylinder 147 is rotatably supported by left and right brackets 148. One of the left and right brackets 148 is fixed to the intermediate stay 146, and the other is fixed to the transmission case 25 and the stay 146. A torsion torsion type fourth spring 149 is fitted in the support cylinder 147, and the brake pedal 100 is urged in the return direction by the fourth spring 149.

  For example, reference numeral 100 'shown in FIG. 18 is a side lever that holds the brake applied. For example, as shown in FIG. 12, the lower part of the brake pedal 100 extends backward with the support cylinder 147 interposed therebetween, while the brake operation shaft 151 slightly protrudes from the front surface of the transmission case 25, for example, as shown in FIG. The front end of the arm body 152 fixed to the brake operation shaft 151 and the rear end of the brake pedal 100 are connected via a coil-type fifth spring 153.

  The rear end of the brake operation shaft 151 extends to the location of the brake 74, and a contact portion that presses the group of friction plates constituting the brake 74 so as to closely contact is provided at the rear end portion. When the brake operation shaft 151 is rotated around the axis, the brake is applied. Needless to say, the braking effect can be adjusted by depressing or depressing the brake pedal 100 (rotating the brake operating shaft 151).

  For example, as shown in FIGS. 14 and 15, an upward arm 154 is fixed to the other end (left end) of the support cylinder 147 to which the brake pedal 100 is attached, and the front end of the clutch rod 155 is connected to the pin 156 on the upward arm 154. It is connected with. In this case, when a pin insertion hole into which the pin 156 is fitted is formed in the upward arm 154, the pin insertion hole is formed into a longitudinally long slot 157 as shown in FIG. The long hole 157 is an example of a release means, and thus the brake pedal 100 can be further stepped on with the clutch rod 155 moved forward. The clutch rod 155 is a composite type having a screw shaft and a long nut, and the length can be finely adjusted.

  For example, as shown in FIGS. 10, 12, and 18 (A), a clutch operating shaft 158 slightly protrudes at the front and right side of the upper surface of the mission case 25, and the clutch operating shaft 158 A clutch arm 159 extending to the left side is fixed to the projecting end portion, and the tip end portion of the clutch arm 159 and the rear end portion of the clutch rod 155 are connected by a pin so as to be relatively rotatable.

  As shown in FIGS. 12 and 9, a movable clutch body (ball clutch) 161 urged in the entering direction by a clutch spring is slidably disposed on the third rotating shaft 67, and A shifter 162 that slides the movable clutch 161 in the cutting direction against the clutch spring 160 is disposed so as to rotate horizontally around the axis of the clutch operating shaft 158. The shifter 162 is fixed to the clutch operation shaft 158.

  Therefore, when the brake pedal 100 is depressed, the clutch rod 155 moves forward, and the clutch arm 159 rotates clockwise in plan view. Then, the shifter 162 also rotates together and the movable clutch 161 is pushed and moved. As a result, the main clutch 68 is disengaged.

  Further, as shown in FIG. 12, for example, a downward arm 164 is fixed to the right end portion of the second control rotary shaft 109 that rotates in conjunction with the shift pedal 62, and the tip (lower end) of the downward arm 164 and the clutch arm 159 is connected by an interlocking shaft 165. The downward arm 164 is integrated with the sensor arm 111. The clutch arm 159 is connected to the interlocking shaft 165 at a position closer to the center of rotation than the attachment portion of the clutch rod 155.

  As shown in FIG. 14, the clutch arm 159 has a substantially L-shaped side section having a back plate 159a, and the interlocking shaft 165 passes through a hole formed in the back plate 159a. A nut 166 that hits the rear surface is attached (in place of the nut 166, a double nut and a washer may be used). Therefore, the clutch arm 159 is not pushed by the interlocking shaft 165 when the second control rotating shaft 109 is rotated by depressing the shift pedal 62. That is, the provision of the interlocking shaft 165 does not hinder the control of the HST 41.

  When the operator completely removes his / her foot from the shift pedal 62, the shift pedal 62 and the second control rotating shaft 109 are returned to the initial posture by the first spring 105. Then, the interlocking shaft 165 moves forward when the second control rotating shaft 109 returns and rotates slightly by the electric motor 122, thereby causing the clutch arm 159 to rotate in the clutch disengagement direction. As the brake pedal 151 is rotated by the pressing action of the clutch arm 159, the brake pedal 100 is also rotated in the same state as when a person has stepped on, so that the traveling vehicle body 1 is braked. Note that the amount of rotation of the brake pedal 100 due to the forward movement of the interlocking shaft 165 is not large, and therefore the brake is lightly applied.

  In this way, when the shift pedal 62 is fully retracted, the brake pedal 100 is lightly applied and the main clutch 68 is disengaged, so that the operator does not have to step on the brake pedal 100 by stepping one foot (right foot) from the position of the shift pedal 62. The travel mode can be switched by lightly operating the speed change lever 54 with the foot left at the position of the speed change pedal 62. For this reason, it is excellent in operability.

  The main clutch 68 needs to be kept in a disengaged state in a state where the shift pedal 62 is fully turned back. The main clutch 68 needs to be kept in a disengaged state in a state where the shift pedal 62 is fully turned back. In this respect, the third spring 137 for returning the HST control rod 125 retains its function. The function of the first spring 105 for returning the speed change pedal 62 may be maintained, or another spring may be provided. When the electric motor 122 is stopped, the sector gear 121 is held unrotatable, so that the second control rotating shaft 109 is also held unrotatable, and the electric motor 122 can function as a holding means.

  When the shift pedal 62 is fully retracted, the brake pedal 100 is lightly rotated, and therefore the brake pedal 100 must be able to be depressed further. In this respect, since the upward arm 154 protruding from the support cylinder 147 and the clutch rod 155 are connected via the long hole 157, the clutch rod 155 does not move and only the upward arm 154 of the brake operation shaft 151 rotates. Is allowed to do. Accordingly, the long hole 157 is an example of a release means that allows the brake pedal 100 to be further depressed while the main clutch is disengaged.

(7) Summary of First Embodiment In the above configuration, since the electric motor 122 is arranged near the mission case 25 to control the HST 41, the HST control rod 125 for operating the HST 41 can be shortened. As described above, the member for controlling the HST 41 can be made compact. Further, since the electric motor 122 is disposed on the opposite side of the speed change pedal 62 with the handle shaft 46 interposed therebetween, it is possible to prevent the electric motor 122 or the like from being disposed in a state where a member is clogged in a specific narrow portion. The members can be arranged neatly and in a well-balanced manner without any design difficulties.

  In particular, if the HST 41 is arranged on the left side surface of the mission case 25 as in the present embodiment, the electric motor 122 can be brought closer to the HST 41, so that the HST control rod 125 can be a simple and short one and is particularly suitable. is there. As in the present embodiment, when the sensor case 112, the sector gear 121 and the downward arm 164 are provided on the second control rotating shaft 109, and the second bearing cylinder 108 is fixed to the forward bracket 110, the sensor case 112 and the electric motor 122 are provided. Since the control members such as the fan-shaped gear 121 are unitized into one unit, parts management and assemblability are excellent.

  In this embodiment, the electric motor 122 and the sector gear 121 are covered with the bonnets 12 and 13 (refer FIG. 1). For this reason, there is no possibility that the operator will pinch his / her foot, and the electric motor 122 and its peripheral part are exposed when the bonnet 13 is removed, so that maintenance and repair can be easily performed.

  When the shift pedal 62 is fully returned, the main clutch 68 is disengaged, but as described with reference to FIG. 14B, the HST control is further performed after the output control arm 126 of the HST 41 returns to the output zero state and rotates. In the process in which the rod 125 is retracted and only the HST control rod 125 is retracted, the interlocking shaft 165 is retracted, the main clutch 68 is disengaged, and the brake 74 is lightly activated. Thereby, the shift operation lever 54 can be operated without changing the foot from the shift pedal 62 to the brake pedal 100.

  Since the holder 134 of the HST control rod 125 is U-shaped in plan view, the holder 134 moves relative to the support pin 133. As a result, the HST control rod 125 is allowed to move backward after the output control arm 126 returns and rotates. However, in this way, the main clutch 68 can be disengaged by the return movement of the shift pedal 62 by providing a relief means such that the holder 134 is U-shaped in plan view.

(8) Second Embodiment Next, a second embodiment shown in FIGS. 20 and 21 will be described. This 2nd Embodiment is a modification of 1st Embodiment, and the parts centering on the control system of HST41 differ. Descriptions of parts common to the first embodiment are omitted, and only differences are described. First, the attachment position of the interlocking shaft 165 for disengaging the clutch differs depending on the return of the shift pedal 62. In other words, in the present embodiment, the front end of the interlocking shaft 165 is connected to the downward projecting portion 111a (see FIG. 17) provided on the sensor bracket 111. By connecting to the sensor bracket 111 in this way, members can be omitted and the structure can be simplified.

  Next, the peripheral part of the sensor case 112 is different. First, as a member corresponding to the drive arm 107 of the first embodiment, the present embodiment is different in that a circumferential cam 107 ′ is used. Further, as shown in FIG. 20, a rearward-facing auxiliary arm 111b is integrally provided on a portion of the sensor bracket 111 opposite to the driven arm 113 with the sensor 112 interposed therebetween, and a pin 115 fixed to the auxiliary arm 111b is attached to the driven arm. The pin 115 is brought into contact with the outer peripheral surface of the peripheral cam 107 ′ through the long hole 114 of 113. In order to keep the pin 115 in contact with the cam 107 ′, the auxiliary arm 111 b is pulled downward by the spring 111 c (the direction in which the transmission lever 62 is returned to the original position).

  As shown in FIG. 21 (B), the circumferential cam 107 'has first to third guide surfaces 107a, 107b, 107c in order from the rotation axis. Adjacent guide surfaces continue in a crossed state at an obtuse angle in a side view. Therefore, each guide surface 107a, 107b, 107c is inclined so as to be farther from the rotation axis as it goes to the tip, and the inclination angle has a relationship of first guide surface 107a <107b <107c.

  In this embodiment, first, since the guide surfaces 107a, 107b, and 107c are inclined, the rotation of the first control rotating shaft 103 is transmitted to the driven arm 113 in an amplified state. The responsiveness of the sensors 116a and 116b shown is excellent, and as a result, adjustment (fine adjustment) for controlling the rotation of the electric motor 122 by stepping on and returning the transmission lever 62 is easy. The response of HST due to the movement of the camera is greatly improved.

  Further, the acceleration region (or deceleration region) is divided into, for example, three areas of low speed, medium speed, and high speed, and the amount of depression (or return amount) per unit time of the shift lever 62 and the amount of acceleration per unit time of HST. Can be changed in three areas, so that the acceleration performance can be improved, thereby improving the driving feeling.

  In this embodiment, since the main clutch 68 is disengaged after the speed change lever 62 has completely returned, the travel is stopped, so that there is an area of play where the speed change lever 62 is rotated in the travel stop state. In view of this, it is preferable that this play be as small as possible. In this regard, in the present embodiment, the amount of movement of the pin 115 (that is, the amount of rotation of the second control drive shaft 109) is secured to an amount necessary for disengaging the main clutch 68, while the amount of rotation of the speed change lever 62 is slightly reduced. Therefore, the acceleration response can be improved by reducing the play interval of the speed change lever 62 as much as possible.

  The next difference is that a support plate 119 for attaching the electric motor 122 and the fan-shaped gear 121 is also fixed to the intermediate stay 146. The support plate 119 is fixed to the intermediate stay 146 via a bracket 146b. In this way, by supporting the support plate 119 from both the front and rear sides, the support plate 119 can be prevented from being bent, and the sector gear 121 and the electric motor 122 can be accurately positioned. As a result, the control of the HST 41 can be performed smoothly.

  Next, the connection mechanism of the throttle wire 130 is different. That is, in the present embodiment, as shown in FIG. 20, the output control arm 126 is provided with a rearward protruding portion 126a, and the throttle wire 130 is connected to the rearwardly protruding portion 126a via the second spring 129. One end of the cable conduit 130a is fixed to a support member (not shown). The support member is fixed to the mission case 25 (may be fixed to a stay member connected to the left and right side frames 12). In the present embodiment, the engine 23 is disposed at the rear portion of the traveling vehicle body 1. When this embodiment is adopted, the length of the throttle wire 130 can be shortened, and it does not interfere with other members. There is an advantage that assemblability is improved.

  On the left side of the support plate 119 to which the sector gear 121 is attached, an angular velocity sensor S for detecting the left-right inclination of the vehicle body is disposed. The angular velocity sensor S is attached to the front frame 13 via a bracket S ′. This angular velocity sensor S is used to hold the seedling planting device 2 in a horizontal posture.

(9). Outline of Third Embodiment Next, a third embodiment shown in the drawings of FIG. Members having the same functions as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted unless particularly necessary. For example, as shown in FIG. 23, in this third embodiment, the engine 23 is mounted on the front portion of the traveling vehicle body 1. Although the traveling vehicle body 1 has left and right side frames 18, in the present embodiment, the left and right side frames 18 are separated in the front and rear, and the side frames 18 separated in the front and rear are welded to a horizontally elongated center frame 168.

  Further, as clearly shown in FIG. 22B, the front ends of the left and right side frames 18 are connected by a front frame 19, and the front portion of the side frame 18 has a front U-shaped (or U-shaped) front and rear. Two support frames 169 are fixed, and the engine 23 is supported by these two support frames 169. The engine 23 has a posture in which the crankshaft is directed in the left-right direction, and the output pulley is disposed on the left side of the engine 23.

  The transmission case 25 is disposed behind the engine 23, and the front axle case 28 is fixed to the left and right outward projecting portions 25 a and 25 b, and the upper end portion of the front axle case 28 is fixed to the side frame 18. Further, the transmission case 25 and the rear axle case 30 are connected by the joint member 40, and therefore the transmission case 25 also serves as the structural material of the traveling vehicle body 1 as in the first embodiment.

  For example, as clearly shown in FIG. 27, in this embodiment, the power steering unit 44 is integrated with the front portion of the mission case 25. That is, the gear case of the power steering unit 44 is formed integrally with the transmission case 25, and the steering unit is attached to the gear case. Although not clearly shown in the drawing, the handle shaft 46 and the handle post 45 are composed of a main part attached to the power steering unit 44 and an upper part connected to the upper end thereof, and from a rearward tilt angle of the main part. Also the rear tilt angle of the upper part is increased. The main part and upper part of the handle shaft 46 are connected by a universal joint.

  The function of the traveling transmission device 24 is the same as that of the first embodiment. The HST 41 is arranged on the left side portion of the mission case 25, the front axle device 28 is attached to the left and right projecting portions 25a and 25b of the mission case 25, and the rear surface portion. A rear wheel drive shaft 43 is provided, and a work power output unit 89 is continuous with the right outward projecting portion 25b. A general-purpose hydraulic pump 58 driven by the input shaft 42 is attached to the right side surface of the mission case 25 opposite to the HST 41. In this embodiment, the mission case 25 has a longitudinally long partition plate 171 (see FIG. 32B) as a specific configuration, and the partition plate 171 has a bearing function to increase strength. .

  As shown in FIG. 25, in this embodiment, an intermediate rotation shaft 69 'is interposed between the first rotation shaft 66 and the second rotation shaft 69, and a gear 70' provided on the intermediate rotation shaft 69 '. The driven gear 70 'meshes with the gear.

  For example, as shown in FIGS. 26 and 27, a brake operation shaft 151 is disposed in a substantially vertical position on the right-side part and the front-side part of the mission case 25 as in the first embodiment. The clutch operating shaft 158 is arranged in a vertical posture at the left and right intermediate portions, and the transmission operation shaft 139 is arranged in a substantially horizontal posture at the front and rear intermediate portions of the transmission case 25.

  Although the essential functions of the operation shafts 151, 158, and 139 are the same as those in the first embodiment, the speed change operation shaft 139 can select five positions. That is, it is possible to select five positions: road traveling (high speed traveling), neutral, planting traveling (low speed traveling), seedling joining, and reverse traveling. Therefore, as clearly shown in FIG. 26C, a branch groove 55a is formed in the guide hole 55 into which the speed change operation lever 54 is fitted so that the speed change operation lever 54 can also be held at five positions. The guide hole 55 is opened in a dedicated auxiliary plate 53a.

  As shown in FIG. 26 and FIG. 28, the movement of the speed change lever 54 includes a longitudinal rod 142 connected to the speed change lever 54, a bell crank lever 172 having one end connected to the lower end of the longitudinal rod 142, and a bell crank lever 172. The front and rear longitudinal rods 173 are connected to the other end of the rod, the arm 174 is coupled to the rear end of the horizontal rod 173, the longitudinal shaft 175 is fixed to the arm 174, and is fixed to the lower end of the longitudinal shaft 175. This is transmitted to the speed change operation shaft 139 via the shifter 176.

  The bell crank lever 172 is rotatably attached to the left bracket 177, and the left bracket 177 is fixed to a left and right longitudinal stay 178 as shown in FIG. Further, as shown in FIG. 27, the longitudinal shaft 175 is rotatably attached to the mission case 25.

  For example, as shown in FIG. 26, the shift pedal 62 and the brake pedal 100 are disposed on the right side of the handle post 45, and the electric motor 122 is disposed on the left side of the handle post 45. As shown in FIG. 31, in this embodiment, the electric motor 122 is covered with a protective case 179.

(10) Control mechanism In this embodiment, as shown in FIG. 29A, a potentiometer 181 is attached to the right side of the speed change pedal 62 in the side frame 18 via a side bracket 182 to change the speed. The movement of the pedal 62 is detected by a potentiometer 181. More precisely, the potentiometer 181 has a rotation type detection lever 183, and a wire pusher 184 attached to the detection lever 183 is brought into contact with the back surface of the speed change pedal 62, whereby the speed change pedal 62. The rotation angle can be detected.

  As shown in FIGS. 29B and 30, the brake pedal 100 is connected to a right bracket 185 fixed to the stay 178. In this case, the lower end portion of the brake pedal 100 is connected to the right bracket 185 with a pivot pin 186, and the brake rod 187 is connected to a portion slightly above the pivot pin 186 with a pin 187a. Accordingly, when the brake pedal 100 is depressed, the brake rod 187 moves forward. The brake pedal 100 is biased to the return posture by the fourth spring 149.

  As shown in FIG. 34A, the protective case 179 covering the electric motor 122 is fixed to the bracket plate 188 fixed to the upper end surface of the power steering unit 44 via the spacer plate 189. The protective case 179 incorporates the same sector gear 121 as in the first embodiment, and the sector gear 121 is driven by an electric motor 122. A rotating shaft 191 of the sector gear 121 is projected outward, an auxiliary arm 190 is fixed thereto, and an HST control rod 125 is connected to the auxiliary arm 190.

  In this embodiment, since the engine 23 is arranged in front of the HST 41, as can be understood from the power system diagram of FIG. 25, the HST 41 is in a posture in which the traveling hydraulic pump 59 is located in front and the traveling hydraulic motor 60 is located in the rear. Is arranged in. For example, as shown in FIG. 31, the output control shaft 61 of the HST 41 protrudes upward similarly to the first embodiment, and the output control arm 126 is fixed to the output control shaft 61.

  For example, as shown in FIGS. 27 and 28, the clutch operation shaft 158 is held by the transmission case 25 so as to rotate about its axis, and as clearly shown in FIG. The movable clutch body 161 slides when the shifter 158a attached to the lower end rotates. When the clutch operating shaft 158 rotates clockwise in plan view, the main clutch 68 is disengaged.

  As shown in FIG. 33, a first interlocking lever 192 is disposed between the clutch operating shaft 158 and the output control arm 126. The first interlocking lever 192 has a substantially L shape extending in the left direction and the rear direction, and a portion near the left end is connected to the transmission case 25 by a first shaft 193 so as to be horizontally rotatable. An HST control rod 125 is connected to the right front end portion of the first interlocking lever 192 via a shaft. A first roller 194 is provided on the upper surface of the left end portion of the first interlocking lever 192.

  On the other hand, a second interlocking lever 195 that overlaps the first roller 194 in plan view is connected to the output control arm 126 by a second shaft 196 so as to be horizontally rotatable. A downward pin 197 protrudes from the rear end portion of the second interlocking lever 195, and a hole 198 into which the downward pin 197 is fitted is provided in the output control arm 126, and further, a front end portion of the second interlocking lever 195 is provided. A wall plate 199 with which the first roller 194 hits is provided.

  Accordingly, when the HST control rod 125 moves backward, the first interlocking lever 193 rotates clockwise, and then the output control arm 126 rotates counterclockwise (that is, in the speed increasing direction) via the second interlocking lever 195. Rotate. The output control arm 126 is pulled backward (deceleration direction) by the sixth spring 200, and the sixth spring 200 is connected to the mission case 25 (see FIG. 26A). Since the first roller 194 of the first interlocking lever 192 is in contact with the wall plate 199 of the second interlocking lever 195 from behind, the first interlocking lever is further turned on after the output control arm 126 returns and rotates in the direction of zero output. 192 can be rotated back (HST control rod 125 can be retracted).

  A clutch arm 201 extending to the right rear is fixed to the clutch operation shaft 158. The base end portion of the clutch arm 201 projects forward, and a second roller 202 is attached to the upper surface of the projecting end portion so as to be horizontally rotatable. The cam body 203 is connected to the rear end portion of the first interlocking lever 192 so as to be horizontally rotatable, and the front end portion of the cam body 203 is brought into contact with the second roller 202.

  FIG. 33A shows a state in which the speed has been fully increased. When the HST control rod 125 moves forward from this state, the first interlocking lever 192 escapes and rotates counterclockwise. Until the output control arm 126 returns and fully rotates, the cam body 203 does not rotate and does not apply torque to the clutch arm 201. However, after the output control arm 126 returns and fully rotates, the cam body 203 does not rotate. When the HST control rod 125 moves forward, a pressing force acts on the second roller 202 in the process, and thereby the clutch arm 201 and the clutch operating shaft 158 rotate (rotate) in the clockwise direction, and then the main clutch 68. Cuts out.

  An action portion for pressing the second roller 202 of the cam body 203 is indicated by reference numeral 204. In addition, a stepped portion (concave portion) 205 that holds the second roller 202 is formed in the cam body 203 continuously with the action portion 204. The main clutch 68 incorporates a spring that pushes the movable clutch body 161, and the clutch arm 201 acts to rotate counterclockwise by this spring.

  For example, as shown in FIGS. 28, 31, and 33, the brake operation shaft 151 is fixed with a first brake arm 206 projecting substantially to the right side of the brake operation shaft 151, and both left and right sides of the brake operation shaft 151. A second brake arm 207 extending in the direction fits in a relatively rotatable manner. The right end portion of the second brake arm 207 is positioned in front of the first brake arm 206, and the first brake arm 206 and the second brake arm 207 are back plates 208 and 209 through which the brake rod 187 passes. have.

  The brake rod 187 is provided with a front stopper (nut) 210 that can hit the back plate 209 of the second brake arm 207 from the front and a stopper spring 211 that hits the back plate 208 of the first brake arm 206 from the back. Further, the brake rod 187 is provided with an intermediate stopper (double nut) 212 that can come into contact with the back plate 209 of the second brake arm 207 from behind. There is a gap between the intermediate stopper 212 and the front stopper 210.

  A portion of the second brake arm 207 on the left side of the rotation center has a groove shape (channel shape) that opens downward, and a third roller provided at the right end of the clutch arm 201 in the groove. 213 is inserted. Therefore, the clutch arm 201 and the second brake arm 207 rotate in conjunction with each other.

  As shown in FIG. 35A, a throttle arm 215 extending substantially in the front-rear direction is connected to the left outer surface of the protective case 179 that covers the electric motor 122 by an arm shaft 216 so as to be rotatable. One end of a throttle wire 130 is connected to the tip via a spring 217, and the throttle wire 130 is inserted into a cable conduit 130 a fixed at one end to a protective case 179. The other end of the throttle wire 130 is attached to the throttle lever of the engine 23.

  On the other hand, a cam hole 218 extending in the rotation center direction is formed in the sector gear 121, and a roller 220 is provided at the tip of an inner link 219 fixed to the inner end portion of the arm shaft 216, and this roller 220 is attached to the cam hole 218. It is inserted in.

  The cam hole 218 is formed to be non-concentric with respect to the rotation center of the sector gear 121, and has a profile in which the distance from the axis increases as the sector gear 121 rotates in the speed increasing direction. . When the sector gear 121 is rotated in the speed increasing direction, the throttle arm 215 is rotated by the action of the cam hole 218, whereby the output of the engine 23 is increased. That is, the output of the engine increases with the traveling speed. By devising the shape of the cam hole 218, the relationship between the running speed and the engine output can be changed variously. The engine output control mode using such a cam mechanism can also be applied to the first embodiment.

(11). Summary of Third Embodiment In the third embodiment, the rotation angle of the shift pedal 62 is detected by a potentiometer 181 (see FIG. 29A), and the electric motor 122 is operated based on a signal from the potentiometer 181. When driven, the HST control rod 125 moves back and forth, whereby the HST 41 is controlled.

  The potentiometer 181 detects the rotation of the shift pedal 62 as a numerical value such as a resistance value, a current value, or a pulse number, and when the shift pedal 62 is depressed or rotated back, the numerical value changes greatly or slightly. Or Therefore, when the value of the potentiometer 181 continues to change greatly, the electric motor 122 continues to rotate forward, and when the value continues to change small, the electric motor 122 continues to rotate reversely, and the rotation of the shift pedal 62 stops. The speed of the rice transplanter can be controlled by performing a control to stop the rotation of the electric motor 122 when the numerical value disappears. For this reason, the driving | running | working feeling similar to a passenger car can be obtained.

  Then, when the operator removes his / her foot from the shift pedal 62 while traveling, the shift pedal 62 returns with a spring, and accordingly, the HST 41 is controlled to decelerate, and the traveling vehicle body 1 is eventually stopped. As already described, at a stage just before the shift pedal 62 completely returns, the output control arm 126 returns and fully rotates. In other words, buffer means is provided in which the speed change pedal 62 is further returned after the output control arm 126 has returned and turned completely.

  Therefore, even if the output control arm 126 returns and rotates completely, the HST control rod 125 moves forward by a slight size, and then the clutch arm 201 rotates clockwise by the pressing action of the cam body 203. The clutch 68 is disengaged and the traveling vehicle body 1 is held in a stopped state. That is, the main clutch 68 is disengaged almost at the same time when the traveling vehicle body 1 stops traveling, and the brake is applied lightly. Thus, the operator can operate the shift operation lever 54 without stepping the right foot one by one.

  When the shift pedal 62 has completely returned, the rotation of the electric motor 122 stops. Even in this state, the state where the main clutch 68 is disengaged and the brake is effective must be maintained, but this function is achieved by fitting and holding the second roller 202 on the step portion 205 of the cam body 203 as described above. Done. Of course, it is possible to use the elastic restoring force of the return spring 105 of the shift pedal 62 (or the return spring 200 of the output control arm 126). Alternatively, when the sector gear 121 is driven by the electric motor 122, a worm gear can be provided in the electric motor 122 and meshed with the sector gear 121. In this case, the return rotation of the sector gear 121 is applied to the motor. Since it does not act, the HST control rod 125 can be securely held in the retracted position with the electric motor 122 turned off.

  The brake rod 187 can be further advanced in a state in which the second brake arm 207 is completely rotated counterclockwise. That is, when the brake pedal 100 is further depressed, the brake rod 187 moves forward and the first brake arm 206 is pushed by the stopper spring 211, so that the brake can be applied strongly. Therefore, in the present embodiment, the first brake arm 206 and the second brake arm 207 are provided independently as a release means.

  Further, when the brake pedal 100 is strongly depressed during traveling, the first brake arm 206 is rotated by the pushing action of the stopper spring 211 to apply the brake, and the intermediate stopper 212 of the brake rod 187 is moved to the first position at the end of the depression of the brake pedal. 2 hits the brake arm 209, thereby disengaging the main clutch 68.

  For example, as can be understood from FIG. 31, in this embodiment, the output control shaft arm 126, the interlocking levers 195, 192, 203 and the brake arms 207, 206 are arranged in a substantially lateral direction at a location above the mission case 25. Therefore, there is an advantage that the control mechanism can be made compact. When the engine 23 is mounted on the front part of the traveling vehicle body 1, the space covered with the bonnets 12 and 13 is filled with many members. In this embodiment, the output control shaft arm 126 and the levers 195 and 192 are used. 203, the clutch arm 201, and the brake arms 207 and 206 are disposed in the space between the transmission case 25 and the vehicle body cover 37, so that there is no problem of interference with other members, thereby reducing the design effort. There is an advantage.

  Moreover, when the electric motor 122 and the sector gear 121 are covered with the protective case 179 as in the present embodiment, there is an advantage that high safety and waterproofness can be ensured. Further, when the movement of the speed change pedal 62 is detected by the potentiometer 181 as in the present embodiment, for example, various outputs of the engine 23 can be easily controlled according to the amount of depression of the speed change pedal 62. This is an advantage that various controls can be easily performed with the movement of the pedal 62 as a trigger.

(12). Others The present invention can be embodied in various ways other than the above embodiment. For example, a belt type (CVT) can be adopted as the continuously variable transmission. Of course, the present invention can also be applied to a riding-type agricultural machine that does not include a continuously variable transmission. It is also possible to mount the engine and the crankshaft on the traveling vehicle body 1 with the posture extending in the front-rear direction. Moreover, the application object of this invention is not restricted to a rice transplanter, It can apply also to other farm work machines, such as a scraper and a vegetable transplanter.

  The present invention can be embodied in a riding type agricultural machine such as a rice transplanter and has high utility. Therefore, it has industrial applicability.

DESCRIPTION OF SYMBOLS 1 Traveling body 2 Seedling planting device 3 Front wheel 4 Rear wheel 9 Steering area 10 Seat 11 Steering handle 23 Engine 24 Traveling transmission 25 Mission case 41 HST as an example of continuously variable transmission
54 Speed change lever 61 Output control shaft of HST 62 Shift pedal 68 Main clutch 74 Brake 100 Brake pedal 109 Second control rotary shafts 116a and 116b driven by the actuator Limit switch 122 as an example of sensor device Electric drive as an example of actuator Motor 126 HST output control arm 139 Shifting operation shaft 151 for gear switching Brake operation shaft 158 Clutch operation shaft 159 Clutch arm 164 Downward arm 165 Interlocking shaft 181 Potentiometer 201 as an example of sensor device Clutch arms 206 and 207 Brake arm

Claims (6)

An engine, a travel transmission that shifts the power of the engine, a shift operation lever that can be manually operated by the operator in a seated state, a foot-operated shift pedal and a brake pedal that can be operated by the operator in a seated state, The traveling transmission device has a transmission case and a gear group for shifting, a clutch, and a brake are built in the transmission case, and the shifting operation lever can be operated when the clutch is disengaged. ing,
A riding-type agricultural machine
The shift pedal and the main clutch are interlocked so that the main clutch is disengaged when returning to a travel stop state where the shift pedal is not depressed,
Riding type farm work machine. The shift pedal, the main clutch, and the brake are interlocked so that the main clutch is disengaged and the brake is effective when returning to the travel stop state where the shift pedal is not depressed,
The riding type agricultural working machine according to claim 1. The transmission has a continuously variable transmission to which power from an engine is transmitted, and an output of the continuously variable transmission is transmitted to a gear group for transmission via a main clutch; and The continuously variable transmission is dynamically controlled by an actuator driven by sensor means for detecting movement of the shift pedal, and a main clutch and a brake are operated in conjunction with a member moving by the actuator.
The riding type agricultural machine according to claim 2. The brake can be operated by depressing a brake pedal, and it is allowed to further depress the brake pedal after the brake works in conjunction with the shift pedal.
The riding type farm working machine according to claim 2 or 3. The sensor device is composed of an acceleration sensor and a deceleration sensor, both of which rotate together with a rotating shaft driven by the actuator and are held at a neutral position in an OFF state. In the state where the rotating shaft is rotating, either one of the two sensors is turned on, and when the rotating shaft stops, both sensors return to the neutral position and are turned off. In addition, the main clutch is disengaged and the brake is operated in conjunction with the movement of the rotating shaft.
The riding type agricultural working machine according to claim 3 or 4. While the sensor means is a potentiometer, the actuator is an electric motor and is disposed at a front portion of the transmission case, and an output control arm for controlling the continuously variable transmission on the upper surface of the transmission case. And a clutch arm for controlling turning on and off of the main clutch and a brake arm for controlling the brake are arranged to be horizontally rotatable, and the clutch arm and the brake arm are rotated together by an electric motor. ,
The riding type agricultural working machine according to claim 3 or 4.

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