JP2008141999A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combine harvester, that is equipped with a steering switch on its steering handle which solves the problem wherein the traveling machine body turns in an unexpected direction, when an operator accidentally contacts the steering switch, when making turning operation of the steering handle. <P>SOLUTION: The combine harvester is equipped with a selective control switch for selective operation whether a fine control operation of the steering switch is to be made. A steering brake mechanism 167 and a steering clutch mechanism 169, disposed in between an HST-type variable-speed mechanism 64 for turning use and a differential gear mechanism 86 work, in such a manner that the power transmission from the mechanism 64 to the mechanism 86 is permitted to or blocking in an interlocked manner, with the on/off operation of the selective control switch. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a work vehicle such as a farm work machine such as a combine machine or a special work machine such as a crane truck, and more particularly to a configuration for steering a traveling machine body in the work vehicle.

  Conventionally, a combine as a work vehicle is configured to transmit the power of an engine mounted on a traveling machine body to left and right traveling crawlers via a straight driving and turning hydraulic drive device and a differential mechanism. Yes.

  An example of a combine having such a configuration is disclosed in Patent Document 1. In the combine disclosed in Patent Document 1, the drive output amount of the hydraulic drive device for straight travel, that is, the straight travel speed of the traveling machine body is adjusted in accordance with the operation amount of the main transmission lever provided in the control unit of the traveling machine body. If the main transmission lever is in the neutral position, the traveling aircraft does not go straight.

  On the other hand, the amount of drive output of the turning hydraulic drive unit, that is, the traveling (turning) direction and turning speed of the traveling vehicle body is determined by the turning direction of the round steering handle erected in front of the control seat in the control unit and It is adjusted according to the amount of rotation operation.

The steering wheel portion of the steering handle is provided with an alignment switch as manual input means. The alignment switch is for finely adjusting (finely correcting) the traveling direction of the traveling machine body to the left and right, and is configured to be tiltable to the left and right with the root portion as a rotation fulcrum. When the alignment switch is tilted to the left or right, the traveling machine body makes a slight turn to the left and right, and the alignment is performed so that the weeding body of the cutting unit is aligned with the planted grain rows in the field.
Japanese Patent Laid-Open No. 9-248039

  By the way, according to the description of Patent Document 1, the alignment switch is provided on the right hand side grip portion of the handle wheel portion, and the operator tilts the alignment switch to the left and right even while holding the handle wheel portion. it can.

  However, in the configuration of Patent Document 1, since the alignment switch is present at a position where the operation can be performed without releasing the hand from the steering handle, there is a possibility that the alignment switch may be accidentally contacted during the operation of the steering handle. . When such a situation occurs, there has been a problem that the traveling body turns in an unexpected direction by operating both the steering handle and the alignment switch, resulting in lack of safety during traveling.

  Therefore, the present invention has as a technical problem to eliminate a problem caused by the steering handle and the manual input means coexisting.

  In order to solve this technical problem, the invention of claim 1 is to transmit the power of the engine mounted on the traveling machine body to the traveling unit from the straight drive and turning hydraulic drive devices via the differential mechanism. A steering handle for changing the traveling direction of the traveling machine body, and a manual input means for finely adjusting the traveling direction of the traveling machine body in the steering handle. Provided with a selection means for selecting whether or not fine adjustment operation of the manual input means is possible, and is disposed between the turning hydraulic drive device and the differential mechanism. The transmission switching mechanism is configured to allow or prevent power transmission from the turning hydraulic drive device to the differential mechanism in conjunction with the selection operation of the selection means. It is.

  According to a second aspect of the present invention, in the work vehicle according to the first aspect, the work vehicle includes a work clutch for interrupting power transmission to a work unit provided in the traveling machine body, and the work clutch is in a disengaged state. Even if the selection means is in the entering state permitting the fine adjustment operation of the manual input means, the fine adjustment operation of the manual input means is invalidated.

  According to a third aspect of the present invention, in the work vehicle according to the first or second aspect, when the selection means is in a cut-off state that prohibits the fine adjustment operation of the manual input means, the turning operation position of the steering handle Is out of the neutral position, the transmission switching mechanism is configured to allow power transmission from the turning hydraulic drive device to the differential mechanism.

  According to a fourth aspect of the present invention, in the work vehicle according to any one of the first to third aspects, when the selection means is in an entering state permitting fine adjustment operation of the manual input means, When the rotation operation position is out of a predetermined rotation angle range, the fine adjustment operation of the manual input means is invalidated.

  A fifth aspect of the present invention is the work vehicle according to the fourth aspect, further comprising a range setting device for presetting the predetermined rotation angle range.

  According to the first aspect of the present invention, since the selection means for selecting whether or not the fine adjustment operation of the manual input means provided on the steering handle is selected is provided, the manual input means can be operated by turning the selection means. If the fine adjustment operation is prohibited, even if the manual input means is accidentally touched, the turning motion of the traveling machine body is not executed.

  For this reason, it is possible to reduce the possibility that the traveling machine body will turn in an unexpected direction while the steering handle is provided with manual input means (the manual input means can be operated while holding the steering handle). This has the effect of being excellent in driving safety.

  In addition, if the fine adjustment operation of the manual input means is prohibited by the turning operation of the selection means, the transmission switching mechanism arranged between the turning hydraulic drive device and the differential mechanism is different from the turning hydraulic drive device. Since power transmission to the dynamic mechanism can be prevented, the straight running stability of the traveling machine body is also improved.

  In the invention of claim 2, when the work clutch for interrupting transmission of power to the working unit provided in the traveling machine body is in the disengaged state, the selection means is in the on state permitting fine adjustment operation of the manual input means. Also, the fine adjustment operation of the manual input means is invalidated.

  “When the working clutch is in the disengaged state” corresponds to a non-working state such as traveling on the road or over a saddle, that is, when not working. For this reason, if constituted as in claim 2, even if the operator forgets to turn off the selection means during non-work such as traveling on the road, as long as the work clutch is in the disengaged state, the traveling machine body by the manual input means Is not executed. Therefore, it is possible to reliably suppress the risk that the traveling machine body is inadvertently turned in an unexpected direction, and it is possible to further increase traveling safety.

  In the invention of claim 3, when the selection means is in a cut-off state that prohibits the fine adjustment operation of the manual input means, the transmission switching mechanism is turned when the turning operation position of the steering handle is out of the neutral position. It is comprised so that the motive power transmission from the hydraulic drive device for a motor may be permitted.

  By adopting such a configuration, halfway automatically switches to a state in which power can be transmitted from the turning hydraulic drive device to the differential mechanism in the process of turning the steering handle, without turning on and off the selection means. it can. Therefore, there is an effect that the operation burden on the operator can be reduced.

  In the fourth aspect of the invention, when the selection means is in the entering state permitting the fine adjustment operation of the manual input means, the manual operation is performed when the rotation operation position of the steering handle is out of the predetermined rotation angle range. The fine adjustment operation of the input means is invalidated.

  When such a configuration is adopted, for example, when turning the traveling machine body (normally turning), even if the manual input means is accidentally touched, the traveling machine body is turned slightly by the manual input means regardless of whether the selection means is turned on or off. The action is not performed. Therefore, in this respect as well, it is possible to reduce the operation burden on the operator and contribute to further improvement in traveling safety.

  According to the invention of claim 5, since it further comprises a range setter for presetting the rotation angle range of the steering handle when the fine adjustment operation of the manual input means is validated, the operation of the range setter Thus, the aforementioned rotation angle range can be changed and adjusted arbitrarily and easily. For this reason, there exists an effect that it can contribute to the operativity improvement of a steering handle or a manual input means.

  Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings (FIGS. 1 to 13) when applied to a combine as a work vehicle. 1 is a side view of the combine, FIG. 2 is a plan view of the combine, FIG. 3 is a schematic plan view of the front part of the cutting part, FIG. 4 is a front explanatory view of the front part of the traveling machine body, and FIG. 5 is a skeleton diagram of the power transmission system 6 is a skeleton diagram of the power transmission system in the transmission case, FIG. 7 is a hydraulic circuit diagram of the combine, FIG. 8 is an explanatory diagram schematically showing the connection relationship between the operating means and the hydraulic drive device, and FIG. FIG. 10 is an enlarged plan view of the steering handle, FIG. 11 is a schematic explanatory diagram of the selection adjusting switch, FIG. 12 is a functional block diagram of the controller, and FIG. 13 is a flowchart of automatic steering control.

(1). First, the schematic structure of the combine will be described with reference to FIGS. 1 and 2.

  The combine for 6-saw cutting in the embodiment includes a traveling machine body 1 supported by a pair of left and right traveling crawlers 2 as traveling portions. At the front part of the traveling machine body 1, a harvesting part 3 that is taken in while harvesting a planted grain culm C (uncut grain culm, see FIG. 3) in the field is mounted so as to be adjustable up and down by a single-acting hydraulic cylinder 4. Yes.

  A threshing unit 6 with a feed chain 7 and a grain tank 8 for storing grain after threshing are mounted on the traveling machine body 1 side by side. In the embodiment, the threshing unit 6 is disposed on the left side in the traveling direction of the traveling machine body 1, and the grain tank 8 is disposed on the right side in the traveling direction of the traveling machine body 1. The mowing unit 3 and the threshing unit 6 correspond to the working units described in the claims.

  A control unit 9 is provided between the harvesting unit 3 and the grain tank 8. A round steering handle 10 for changing the traveling (turning) direction and turning speed of the traveling machine body 1, a control seat 11 on which an operator is seated, and the like are disposed in the control unit 9. An engine 12 as a power source is disposed below the control unit 9. A mission case 13 is disposed in front of the engine 12 for appropriately shifting the power from the engine 12 and transmitting it to the left and right traveling crawlers 2.

  The mowing unit 3 includes a clipper-type cutting blade device 14, a culm pulling device 15 for six strips, a culm transporting device 16, and a weeding body 17 (seven in the embodiment). The cutting blade device 14 is disposed below the cutting frame 5 constituting the framework of the cutting unit 3. The grain raising device 15 is disposed above the cutting frame 5. The corn straw transporting device 16 is disposed between the corn straw pulling device 15 and the front end of the feed chain 7. The weeding body 17 protrudes in front of the lower part of the grain raising device 15. The harvested cereal grains harvested by the harvesting unit 3 are transferred to the feed chain 7 and are threshed by the threshing unit 6.

  In the handling room of the threshing unit 6, a handling cylinder 18 for threshing the harvested cereal meal is built. Below the handling cylinder 18, a sorting device 20 is arranged for performing rocking sorting using a handling net, chaff sheave, or the like and wind sorting using the wind of a Kara fan. After the sorting by the sorting device 20, the first thing such as fine grains collected in the first receiving bowl (not shown) at the bottom of the traveling machine body 1 is the first conveyor and the cereal conveyor (both not shown). ) To the grain tank 8.

  The second item such as the grain with branch stems is sent to the processing drum 19 through the second receiving rod and the reduction conveyor (both not shown) behind the first receiving rod, and is again recycled by the processing drum 19. Threshed. The second item after the threshing is returned to the sorting device 20 and re-sorted.

  The sawdust is sucked into a suction fan (not shown) disposed at the rear part of the threshing unit 6 and then discharged to the outside of the traveling machine body 1 through a discharge port formed at the rear part of the traveling machine body 1. The grain in the grain tank 8 is carried out of the traveling machine body 1 through the discharge auger 21.

  The waste handed over from the rear end of the feed chain 7 to the waste chain 22 (see FIG. 2) is discharged to the rear of the traveling machine body 1 in a long state or is sent to a waste cutter (not shown). After being cut to a short length as appropriate, it is discharged to the rear of the traveling machine body 1.

  As shown in FIG. 3, on the lower surface side of the second weed body 17 counted from the right end among the plurality of weed bodies 17, it protrudes leftward and can be rotated counterclockwise in a plan view of FIG. A left steering sensor 50 with an antenna lever 52 and a right steering sensor 51 with an antenna lever 53 that protrudes in the right direction and can be rotated clockwise in a plan view of FIG. 3 are arranged.

  The left and right steering sensors 50 and 51 detect whether or not the antennal levers 52 and 53 are in contact with the planted grain culm C (uncut grain culm) in the field, whereby the traveling machine body 1 is in a predetermined direction. It is of a contact type (limit switch type) that detects whether or not the vehicle is traveling along (for example, a strip direction described later).

  The distance between the tips of both antennal levers 52 and 53 is set to be shorter than the stock interval L in the row direction in the field (planting direction at the time of rice planting, see X direction in FIG. 3). For this reason, the left and right steering sensors 50 and 51 do not detect the planted culm C at the same time when the traveling machine body 1 is cut in the row direction (the X direction in FIG. 3). In general, the stock interval L in the strip direction is about 30 cm.

  As shown in FIG. 3, a culm passing sensor 54 (in the embodiment, for detecting whether or not the chopped culm taken into the reaper 3 has passed through the lower front end side of the culm pulling device 15. 3) are arranged for each cereal passage portion for two strips. The grain pass sensor 54 is also of a contact type (limit switch type) similar to the left and right steering sensors 50 and 51 described above. That is, by detecting whether or not the sensing body 55 protruding from each culm passage sensor 54 toward the culm passage location is in contact with the chopped culm, the harvested culm in the middle of the chopping unit 3 is conveyed. It is to detect whether or not there is.

  As shown in FIGS. 2 and 3, the height of the cutting unit 3 with respect to the ground (with respect to the field scene) An ultrasonic sensor 56 for detecting the height of the cutting unit 3 is attached with the transmitter (horn unit) of the transmitter and the receiver of the receiver facing the farm scene. The ground height of the cutting unit 3 is obtained from the detection value of the ultrasonic sensor 56. When the installation height of the ultrasonic sensor 56 and the installation height of the cutting blade device 14 are different, the ground height of the cutting unit 3 is obtained by a predetermined conversion based on the detection value of the ultrasonic sensor 56.

  Further, a lift position sensor 57 for detecting the height of the cutting unit 3 with respect to the machine body (relative height of the cutting unit 3 with respect to the traveling machine body 1) is attached to the proximal end portion of the cutting frame 5 near the rotation center. (See FIG. 12). The height of the cutting unit 3 with respect to the machine body is obtained from the up and down rotation angle of the cutting frame 5 detected by the up / down position sensor 57.

(2). Next, the power transmission system of the combine will be described with reference to FIGS.

  In the self-propelled self-removing combine of the embodiment, the power from the engine 12 is appropriately changed by the hydraulic drive device 62 in the mission case 13 and the like via the drive output shaft 24 that protrudes outward from the mission case 13 to the left and right. It is configured to output to the left and right drive wheels 25.

  The engine 12 includes an output shaft 60 that protrudes forward and backward. One of the power from the engine 12 is transmitted from the front end of the output shaft 60 to the hydraulic drive device 62 in the transmission case 13 via the universal joint shaft 61 and the input shaft 59 of the transmission case 13.

  In the transmission case 13, a differential gear mechanism 86 having a hydraulic drive device 62 for shifting the power from the engine 12, a sub-transmission mechanism 85 having a plurality of shift stages, a pair of left and right planetary gear mechanisms 157, and the like. Are installed (see FIG. 6).

  The hydraulic drive device 62 includes a straight traveling HST transmission mechanism 63 including a first hydraulic pump 150 and a first hydraulic motor 151, and a turning HST transmission mechanism 64 including a second hydraulic pump 152 and a second hydraulic motor 153. I have.

  The power from the output shaft 60 toward the hydraulic drive device 62 is transmitted to the linear pump shaft 65 of the first hydraulic pump 150 and the turning pump shaft 66 of the second hydraulic pump 152, respectively. In the straight traveling HST transmission mechanism 63, hydraulic oil is appropriately fed from the first hydraulic pump 150 toward the first hydraulic motor 151 by the power transmitted to the straight traveling pump shaft 65. Similarly, in the turning HST transmission mechanism 64, hydraulic oil is appropriately sent from the second hydraulic pump 152 toward the second hydraulic motor 153 with the power transmitted to the turning pump shaft 66.

  A charge pump 179 for supplying hydraulic oil to the hydraulic pumps 150 and 152 and the hydraulic motors 151 and 153 is mounted on the turning pump shaft 66. The charge pump 179 can be interlocked with the turning pump shaft 66 and is driven by the rotational power of the engine 12.

  In the straight traveling HST transmission mechanism 63, the first hydraulic pump 150 has a function corresponding to the shift position of a main transmission lever 131 (details will be described later) arranged in the control unit 9 and the amount of rotation of the steering handle 10. By changing and adjusting the inclination angle of the rotary swash plate 180 (see FIG. 7) and changing the discharge direction and discharge amount of the hydraulic oil to the first hydraulic motor 151, the straight travel protruding left and right from the first hydraulic motor 151 It is comprised so that the rotation direction and rotation speed of the motor shaft 67 may be adjusted arbitrarily.

  The rotational power of the linear motor shaft 67 in the first hydraulic motor 151 is transmitted to a sub-transmission mechanism 85, which is a conventionally known gear mechanism, and a counter, which will be described later, via a pulley / belt transmission system and a cutting clutch 82. The signal is also branched and transmitted from the case 72 to the tuning input shaft 75 (see FIG. 5) protruding to the center of the traveling machine body 1.

  The sub-transmission mechanism 85 operates the sub-transmission lever 132 (details will be described later) disposed in the control unit 9 to reduce the adjustment range of the rotational power (rotation direction and number of rotations) from the linear motor shaft 67 at a low speed. It is configured to be switchable to three speed stages, high speed and neutral. The brake shaft 154, which is a component of the auxiliary transmission mechanism 85, is provided with a parking brake means 155 such as a wet multi-plate disk.

  The rotational power from the auxiliary transmission mechanism 85 is transmitted to the differential gear mechanism 86 from the auxiliary transmission output gear 156 fixed to the brake shaft 154. The differential gear mechanism 86 includes a pair of left and right planetary gear mechanisms 157 and a relay shaft 158 positioned between the planetary gear mechanism 157 and the brake shaft 154. A center gear 159 fixed to the center portion of the relay shaft 158 meshes with the auxiliary transmission output gear 156 of the brake shaft 154. The side gears 160 fixed to the left and right sides of the relay shaft 158 with the center gear 159 interposed therebetween mesh with the outer peripheral surfaces of the corresponding ring gears 165 (details will be described later).

  The pair of left and right planetary gear mechanisms 157 are formed symmetrically and includes a pair of left and right carriers 161 that rotatably support a plurality of planetary gears 162 on the same radius. These two carriers 161 are arranged so as to oppose each other at an appropriate interval on the same axis.

  Sun gear members 164 are pivotally supported on the left and right sides of the sun shaft 163 located between the left and right carriers 161. Each sun gear member 164 meshes with each planetary gear 162 of the carrier 161 corresponding thereto. The left and right ends of the sun shaft 163 are rotatably supported by bearings positioned at the rotation center of each carrier 161.

  A pair of left and right ring gears 165 having inner teeth on the inner peripheral surface and outer teeth on the outer peripheral surface are arranged concentrically with the sun shaft 163 so that the inner teeth mesh with the plurality of planetary gears 162. . Each ring gear 165 is rotatably supported via a bearing on a drive output shaft 24 that protrudes left and right outward from the outer surface of the carrier 161.

  The rotational power from the subtransmission mechanism 85 is transmitted to the left and right planetary gear mechanisms 157 via the left and right side gears 160 in the relay shaft 158. The rotational power transmitted to the left and right planetary gear mechanisms 157 is transmitted to the drive output shaft 24 of each carrier 161 at the same rotational speed in the same direction.

  On the other hand, in the turning HST type transmission mechanism 64, the inclination angle of the rotary swash plate 182 (see FIG. 8) in the second hydraulic pump 152 in accordance with the amount of turning operation of the steering handle 10 disposed in the control unit 9. And adjusting the rotation direction and the number of rotations of the turning motor shaft 68 protruding from the second hydraulic motor 153 by changing the discharge direction and discharge amount of the hydraulic oil to the second hydraulic motor 153. Is configured to do.

  A turning output gear 166 is rotatably supported on the turning motor shaft 68. Further, a steering brake means 167 (details will be described later) as a transmission switching mechanism for braking the turning motor shaft 68 and the turning output gear 166 is provided at the tip of the turning motor shaft 68.

  The rotational power of the turning motor shaft 68 in the second hydraulic motor 153 is transferred from the turning output gear 166 of the turning motor shaft 68 through the transmission gear 170 of the clutch shaft 168 having the steering clutch means 169. 171 and the reverse gear 172. The forward rotation gear 171 meshes with one (right in the embodiment) of a pair of left and right input gears 173 that are rotatably supported around the sun shaft 163. The reverse gear 172 meshes with the other input gear 173 (left in the embodiment). The left and right input gears 173 are configured to rotate integrally with the corresponding sun gear members 164. In the embodiment, the steering clutch means 169 on the clutch shaft 168 is also a component of the transmission switching mechanism.

  When the right sun gear member 164 is normally rotated (reversely rotated) at a predetermined rotational speed via the normal rotation gear 171 and the right input gear 173 by the normal rotation (reverse rotation) of the second hydraulic motor 153, the left sun gear The member 164 reversely rotates (forward rotation) at the same rotational speed as the right sun gear member 164 via the reverse rotation gear 172 and the left input gear 173. The rotational power transmitted to the left and right planetary gear mechanisms 157 via the left and right sun gear members 164 is transmitted to the drive output shafts 24 of the left and right carriers 161 at the same rotational speeds in opposite directions.

  As can be seen from the above, the shift output from the straight motor shaft 67 and the turning motor shaft 68 is transmitted to the drive wheels 25 of the left and right traveling crawlers 2 via the auxiliary transmission mechanism 85 and the differential gear mechanism 86. As a result, the vehicle speed (traveling speed) and the traveling direction of the left and right traveling crawlers 2 and thus the traveling machine body 1 are determined.

  That is, when the straight motor shaft 67 is driven in the forward or reverse rotation direction with the drive of the turning motor shaft 68 stopped, the rotational power from the straight motor shaft 67 is transmitted to the sub-transmission mechanism 85 and the differential gear. Via the mechanism 86, it is transmitted to the drive wheels 25 of the left and right traveling crawlers 2 at the same rotational speed in the same direction, and the traveling machine body 1 travels straight. In this case, the traveling machine body 1 moves forward when the straight-travel motor shaft 67 (straight-travel HST transmission mechanism 63) is driven in the forward rotation direction, and the traveling machine body 1 moves backward when driven in the reverse rotation direction.

  On the other hand, when the turning motor shaft 68 is driven in the normal or reverse rotation direction with the driving of the linear motor shaft 67 stopped, the turning power from the turning motor shaft 68 via the differential gear mechanism 86 is used. One of the drive wheels 25 of the left and right traveling crawlers 2 rotates forward and the other rotates backward, and the traveling machine body 1 spin-turns on the spot.

  Further, when the turning motor shaft 68 is driven while the linear motor shaft 67 is driven, a difference occurs in the driving speed of the left and right traveling crawlers 2, and the traveling machine body 1 turns larger than the spin turn turning radius while moving forward or backward. Turn left or right at the radius. The turning radius at this time is determined according to the difference in driving speed between the left and right traveling crawlers 2.

  A cooling fan 175 for a radiator is attached to the fan shaft 174 that relays power between the linear pump shaft 65 and the turning pump shaft 66 and the input shaft 59 of the transmission case 13. In the embodiment, the power is transmitted from the fan shaft 174 to both the straight traveling pump shaft 65 and the turning pump shaft 66 via the transmission gear mechanism 176.

  In the embodiment, the power transmitted from the fan shaft 174 to the linear pump shaft 65 via the transmission gear mechanism 176 is transmitted to the vehicle speed constant speed clutch 177, the vehicle speed constant speed mechanism, and the like. It is configured to be able to directly transmit to the subtransmission mechanism 85 via 178 and the linear motor shaft 67. For this reason, when the vehicle speed constant speed clutch 177 is in the engaged state, the power from the engine 12 is directly transmitted to the subtransmission mechanism 85 without passing through the HST transmission mechanism 63 for straight travel. The traveling machine body 1 travels at a constant vehicle speed by rotational driving.

  On the other hand, other power from the engine 12 is branched and transmitted from the rear end of the output shaft 60 in two directions: the discharge auger 21 and the counter case 72 disposed on one side of the engine 12.

  The branching power from the output shaft 60 toward the discharge auger 21 is transmitted to the bottom conveyor 70 and the vertical conveyor (not shown) in the grain tank 8 via the discharge clutch 69, and then the discharge conveyor ( (Not shown).

  The branching power from the output shaft 60 toward the counter case 72 is transmitted to the threshing input shaft 73 of the counter case 72 via the threshing clutch 71, and further branched and transmitted from the threshing input shaft 73 in two directions.

  A part of the power transmitted to the threshing input shaft 73 is transmitted to the rotating shaft of the handling cylinder 6 and the processing cylinder 19 (not shown in FIG. 5) via a pulley / belt transmission system, and the handling cylinder 6 and processing. The body 19 is driven to rotate. Other power from the threshing input shaft 73 is transmitted to the constant speed rotating shaft 74 of the counter case 72 via a bevel gear mechanism provided in the middle thereof.

  Here, the counter case 72 includes the threshing input shaft 73 and the constant speed rotation shaft 74 described above, the tuning input shaft 75, the vehicle speed tuning shaft 76, the cutting transmission shaft 77, and the FC input extending in parallel with the constant speed rotation shaft 74. A cutting speed change mechanism 79 associated with the shaft 78, the tuning input shaft 75 and the vehicle speed tuning shaft 76, a cutting constant speed mechanism 80 associated with the constant speed rotating shaft 74 and the vehicle speed tuning shaft 76, and the vehicle speed tuning shaft 76. And an FC transmission mechanism 81 associated with the FC input shaft 78.

  Part of the power transmitted to the constant speed rotating shaft 74 is transmitted to a sorting device (not shown), the waste chain 22 (not shown in FIG. 5), etc., via a pulley / belt transmission system. The other power from the constant speed rotating shaft 74 is transmitted to the vehicle speed tuning shaft 76 via the cutting constant speed mechanism 80 when the cutting unit 3 is not driven in synchronization with the vehicle speed (traveling speed). Power is transmitted from 76 to the devices 14 to 16 of the cutting unit 3 through the cutting transmission shaft 77.

  On the other hand, a part of the rotational power of the linear motor shaft 67 is transmitted to the tuning input shaft 75 via a reaping clutch 82 as a working clutch. The rotational power transmitted to the tuning input shaft 75 is transmitted to the vehicle speed tuning shaft 76 via the one-way clutch 83 and the cutting speed change mechanism 79 when the cutting unit 3 is driven in synchronization with the vehicle speed. Power is transmitted to the devices 14 to 16 of the cutting unit 3 through the transmission shaft 77. The one-way clutch 83 is configured to transmit power only when the linear motor shaft 67 rotates forward.

  The power transmitted to the vehicle speed tuning shaft 76 is transmitted to the FC input shaft 78 via the FC transmission mechanism 81 and the FC clutch 84, and the feed chain 7 is driven to rotate by the power transmission from the FC input shaft. Has been.

(3). Combined Hydraulic Circuit Structure Next, the combined hydraulic circuit structure will be described with reference to FIG.

  The combine hydraulic circuit 190 shown in FIG. 7 includes the above-described charge pump 179, a main transmission cylinder 191 for changing and adjusting the inclination angle of the rotary swash plate 180 in the first hydraulic pump 150, and an operation to the main transmission cylinder 191. A manual transmission valve 192 for adjusting the supply of oil and an electromagnetic neutral valve 193 for reducing the output of the first hydraulic pump 150 by a predetermined amount are provided.

  The charge pump 179 and the main transmission cylinder 191 are connected via a main transmission oil passage 198, and a manual transmission valve 192 and an electromagnetic neutral valve 193 are disposed in the main transmission oil passage 198. The manual transmission valve 192 is mainly configured to be switched by the main transmission lever 131. The electromagnetic neutral valve 193 is configured to automatically perform switching operation by driving an electromagnetic solenoid 194 corresponding to the neutral operation of the main transmission lever 131.

  When the manual transmission valve 192 is switched by operating the main transmission lever 131, the main transmission cylinder 191 expands and contracts, the inclination angle of the rotary swash plate 180 in the first hydraulic pump 150 is changed, and the first hydraulic motor 151 is operated. The direction and amount of hydraulic oil discharged to the tank changes. As a result, a linear shift operation is performed in which the rotation direction and the rotation speed of the linear motor shaft 67 in the first hydraulic motor 151 are steplessly changed or reversed.

  Further, a feedback operation in which the manual transmission valve 192 returns to neutral by the angle adjustment operation of the rotary swash plate 180 can be executed. That is, when the main transmission lever 131 is neutrally operated, the rotary swash plate 180 is returned to the neutral state in accordance with this operation, and the electromagnetic neutral valve 193 is automatically switched by the excitation of the electromagnetic solenoid 194. The output of the first hydraulic pump 150 is made substantially zero. As a result, the rotational drive of the linear motor shaft 67 in the first hydraulic motor 151 stops.

  The charge pump 179 is connected to an auxiliary transmission cylinder 196 for changing and adjusting the inclination angle of the rotary swash plate 181 in the first hydraulic motor 151 via the main transmission oil path 198 and the auxiliary transmission oil path 199 branched therefrom. Yes. In the sub transmission oil passage 199, an electromagnetic sub transmission valve 195 that automatically switches in response to an operation of a sub transmission lever 132 described later is disposed.

  In this case, when the auxiliary transmission cylinder 196 is expanded and contracted by the automatic switching operation of the electromagnetic auxiliary transmission valve 195, the inclination angle of the rotary swash plate 181 in the first hydraulic motor 151 is forcibly changed, and the first hydraulic motor 151 is changed. Output is selectively switched to high speed or low speed.

  When the electromagnetic subtransmission valve 195 is in a neutral state, the subtransmission cylinder 196 communicates with the transmission case 13 which is also an oil tank, and the inclination angle of the rotary swash plate 181 in the first hydraulic motor 151 is set to the first hydraulic pump 150 and the first hydraulic pump 150. 1 is configured to be adjusted only with hydraulic oil in a closed circuit 197 connecting the hydraulic motor 151.

  In addition to the above-described configuration, the combine hydraulic circuit 190 adjusts the turning cylinder 201 for changing and adjusting the inclination angle of the rotary swash plate 182 in the second hydraulic pump 152, and the supply of hydraulic oil to the turning cylinder 201. A manual revolving valve 202 and an electromagnetic automatic steering valve 203 are provided.

  The turning cylinder 201 is connected to a charge pump 179 via a main transmission oil passage 198 and a turning oil passage 200 branched therefrom, and a manual turning valve 202 and an electromagnetic automatic steering valve 203 are provided in the turning oil passage 200. Has been placed. The manual swing valve 202 is configured to be switchable mainly by the steering handle 10. The electromagnetic automatic steering valve 203 is configured to automatically perform switching operation by driving left and right steering solenoids 204 and 205.

  When the manual swing valve 202 is switched by rotating the steering handle 10, the swing cylinder 201 is expanded and contracted to change the tilt angle of the rotary swash plate 182 in the second hydraulic pump 152, and the second hydraulic motor. The discharge direction and discharge amount of hydraulic oil to 153 change. As a result, a left / right turning operation is performed in which the rotation direction and the number of rotations of the turning motor shaft 68 in the second hydraulic motor 153 are steplessly changed or reversed.

  Also in this case, it is possible to execute a feedback operation in which the manual swing valve 202 is neutrally returned by the angle adjustment operation of the rotary swash plate 182. That is, when the turning operation position of the steering handle 10 is in a neutral position N (see FIG. 10) described later, the rotary swash plate 182 is returned to the neutral state and the output of the second hydraulic pump 152 is made substantially zero. Thus, the rotational drive of the second hydraulic motor 153 due to the turning operation of the steering handle 10 is stopped.

  When the turning operation position of the steering handle 10 is at the neutral position N (see FIG. 10), the manual swing valve 202 does not function (switching operation), and the traveling machine body 1 has the amount of turning operation of the steering handle 10. Do not perform proportional turning.

  In such a case, when the electromagnetic automatic steering valve 203 is automatically switched by the excitation of the left and right steering solenoids 204 and 205, the swing cylinder 201 expands and contracts, and the rotary swash plate 182 in the second hydraulic pump 152. Is changed, and the discharge direction and discharge amount of the hydraulic oil to the second hydraulic motor 153 are changed. As a result, a traveling direction correcting operation for changing the rotational direction and the rotational speed of the turning motor shaft 68 in the second hydraulic motor 153 is executed.

  On the other hand, in the embodiment, when the steering handle 10 is rotated to a position other than the neutral position N while the main transmission lever 131 is tilted to a position other than the neutral position, the operation direction and the operation amount of the main transmission lever 131 are changed. The output of the first hydraulic pump 150 and thus the output of the first hydraulic motor 151 is increased and decreased in the forward and reverse directions, and the output of the second hydraulic pump 152 and the output of the second hydraulic motor 153 is also proportional to the operation amount of the main transmission lever 131. Is configured to change.

  In this case, the turning radius of the traveling machine body 1 becomes smaller as the main transmission lever 131 is operated to the higher speed side, and the traveling machine body 1 always has a size corresponding to the turning operation amount of the steering handle 10 regardless of the vehicle speed. It is set to turn left or right with a turning radius of.

  Conversely, the outputs of the hydraulic pumps 150 and 151 and the hydraulic motors 152 and 153 are changed in proportion to the amount of rotation of the steering handle 10. In this case, the traveling vehicle body 1 turns to the left or right with a small turning radius as the turning operation amount of the steering handle 10 increases, and the vehicle speed of the traveling vehicle body 1 decreases as the turning radius decreases. .

  When the main transmission lever 131 is in the neutral position, even if the steering handle 10 is rotated, the manual swing valve 202 is maintained in the neutral state and the output of the second hydraulic pump 152 is made substantially zero. Thus, the second hydraulic motor 153 is configured to be prevented from rotating.

  By the way, in addition to the above-described configuration, the hydraulic circuit 190 is a component of a cutting shift cylinder 206 for operating a cutting shift slider (not shown) that is a component of the cutting shift mechanism 79 and a component of a cutting constant speed mechanism. A fixed cutting speed cylinder 207 for operating a switching slider (not shown), a threshing cylinder 208 for switching on and off the threshing clutch 71, and a vehicle speed constant speed cylinder 209 for switching on and off the vehicle speed constant speed clutch 177. And a brake cylinder 216 for turning on and off the steering brake means 167 and a clutch cylinder 217 for turning on and off the steering clutch means 169.

  In the charge pump 179, a cutting speed change cylinder 206, a constant cutting speed cylinder 207, a threshing cylinder 208, a constant vehicle speed cylinder 209, and a set of a brake cylinder 216 and a clutch cylinder 217 are arranged in parallel via a counter oil passage 218. It is connected to the.

  In the counter oil passage 218, a cutting shift valve 210 is disposed between the charge pump 179 and the cutting shift cylinder 206, and a cutting constant speed valve 211 is disposed between the charge pump 179 and the cutting constant speed cylinder 207. Has been.

  A threshing valve 212 is disposed between the charge pump 179 and the threshing cylinder 208, and a vehicle speed constant speed valve 213 is disposed between the charge pump 179 and the vehicle speed constant speed cylinder 209.

  Between the set of the brake cylinder 216 and the clutch cylinder 217 and the charge pump 179, an electromagnetic rectilinear valve 214 for adjusting the supply of hydraulic oil to both cylinders 216 and 217 is disposed. The electromagnetic rectilinear valve 214 is configured to automatically perform switching operation by driving a rectilinear solenoid 215 corresponding to the neutral position operation of the steering handle 10 and the auxiliary transmission lever 132.

  In this case, when the electromagnetic rectilinear valve 214 is automatically switched by excitation of the rectilinear solenoid 215, the brake cylinder 216 and the clutch cylinder 217 are expanded and contracted.

  The telescopic operation of the brake cylinder 216 causes the steering brake means 167 to be turned on and off, and as a result, the turning motor shaft 68 of the second hydraulic motor 153 is braked or released.

  On the other hand, the expansion / contraction operation of the clutch cylinder 217 turns the steering clutch means 169 on and off, and as a result, power transmission from the turning motor shaft 68 to the forward rotation gear 171 and the reverse rotation gear 172 (see FIG. 6) is interrupted. The

  That is, when at least one of the steering handle 10 and the auxiliary transmission lever 132 is operated to the neutral position, the differential gear from the turning HST transmission mechanism 64 is operated by the steering brake means 167 and the steering clutch means 169. In the state where the power transmission to the mechanism 86 is blocked and both the steering handle 10 and the auxiliary transmission lever 132 are operated to positions other than the neutral position, the power transmission from the turning HST transmission mechanism 64 to the differential gear mechanism 86 is performed. Is acceptable.

(4). Next, a connection structure between the operation means and the hydraulic drive device will be described with reference to FIG.

  The main transmission lever 131 disposed in the control unit 9 is interlocked and connected to a mechanical switching means 220 disposed in a steering column 90 (see FIG. 9) described later via a relay link mechanism 219. A handle shaft 92 that supports the steering handle 10 from below is also linked to the mechanical switching means 220.

The mechanical switching means 220 of the embodiment includes:
1. When the steering handle 10 is rotated to a position other than the neutral position N (see FIG. 10) while the main transmission lever 131 is tilted to a position other than the neutral position, the smaller the turning operation amount, the smaller the turning radius. Thus, the traveling vehicle body 1 turns left or right, and the vehicle speed of the traveling aircraft body 1 (the turning speed when moving forward and backward) decreases as the turning radius decreases.
2. Even when the main transmission lever 131 is tilted in either the forward or backward direction, the turning operation direction of the steering handle 10 and the turning direction of the traveling machine body 1 coincide (when the steering handle 10 is turned to the right, the vehicle travels. Aircraft 1 turns right, and if steering handle 10 is turned to the left, traveling machine 1 turns left)
3. When the main transmission lever 131 is in the neutral position, it does not function even if the steering handle 10 is operated.
In order to execute various operations, the operating force from the main transmission lever 131 and the steering handle 10 is appropriately converted and transmitted to the vertically long double shaft 221 that is rotatably disposed at the lower end of the steering column 90. Is configured to do.

  The mechanical switching means 220 itself is not directly related to the present invention and will not be described in detail. However, if necessary, refer to Japanese Patent Application Laid-Open No. 2002-274421.

  The double shaft 221 associated with the mechanical switching means 220 is formed in a vertically long concentric shape by a rectilinear outer cylindrical shaft 222 and a turning inner shaft 223 that can be rotated independently of each other. The rectilinear outer cylinder shaft 222 is linked to a rectilinear rotation shaft 225 protruding outward from one side surface of the mission case 13 via a rectilinear link mechanism 224. On the other hand, the turning inner shaft 223 is linked to a turning rotation shaft 227 protruding outward from the other side surface of the transmission case 13 via a turning link mechanism 226.

  Here, the rectilinear rotation shaft 225 is for adjusting the inclination angle of the rotary swash plate 180 of the first hydraulic pump 150 in the rectilinear HST transmission mechanism 63. Functions as an adjustment unit that adjusts the output. The turning shaft 227 is for adjusting the inclination angle of the rotary swash plate 182 of the second hydraulic pump 152 in the turning HST transmission mechanism 64, and adjusts the shift output of the turning HST transmission mechanism 64. Functions as an adjustment unit.

  The linear link mechanism 224 includes a lateral support shaft 230 that is rotatably inserted into a support cylinder 229 fixed to the upper surface of the transmission case 13 via a bracket 228, and a linear advance that projects from the linear cylinder outer shaft 222. The straight relay rod 233 that connects the rotary arm 231 and the first straight swing arm 232 fixed to one end (right end in the embodiment) of the horizontal support shaft 230, and the other end of the horizontal support shaft 230 (the embodiment). In this case, a linear movement interlocking rod 236 that connects a linear movement second swing arm 234 fixed to the left end) and a linear operation arm 235 attached to the linear rotation shaft 225 is provided.

  One end portion (front end portion in the embodiment) of the rectilinear relay rod 233 is pivotally attached to a rectilinear pivot arm 231 on the rectilinear outer cylinder shaft 222 side by a longitudinal pivot pin 237. Yes. The other end portion (rear end portion in the embodiment) of the rectilinear relay rod 233 is pivoted to the first rectilinear swing arm 232 on the side support shaft 230 side via a pivot pin 238 that is laterally laterally oriented. It is worn.

  One end portion (upper end portion in the embodiment) of the linear advancement interlocking rod 236 is pivotally attached to the second advancement swing arm 234 on the side of the lateral support shaft 230 so as to be rotatable by a left and right laterally attached pivot pin 239. Yes. The other end portion (the lower end portion in the embodiment) of the rectilinear interlocking rod 236 is pivotally attached to a rectilinear operation arm 235 on the rectilinear pivot shaft 225 side via a pivot pin 240 which is front-rear and sideways. ing.

  When the main transmission lever 131 is tilted forward from the neutral position, the mechanical switching means 220 moves the outer straight shaft 222 and the straight turn arm 231 around the turn inner shaft 223 via the relay link mechanism 219. By rotating integrally in the direction of the arrow SA, the straight relay rod 233 is pulled forward (moved), the first straight swing arm 232, the lateral support shaft 230, and the second straight swing. The arm 234 rotates integrally in the direction of the arrow SB around the lateral support shaft 220.

  Then, the rectilinear second swing arm 234 pulls up the rectilinear interlocking rod 236 by the rotational movement in the direction of arrow SB, so that the rectilinear operation arm 235 and hence the rectilinear rotation shaft 225 are moved in the direction of the arrow SC (forward increase). It rotates in the speed direction (or reverse deceleration direction). As a result, the traveling machine body 1 performs the forward movement in proportion to the forward tilting operation amount of the main transmission lever 131.

  On the other hand, when the main transmission lever 131 is tilted backward from the neutral position, the mechanical switching means 220 moves the rectilinear outer cylindrical shaft 222 and the rectilinear rotation arm 231 in the direction of the arrow SD via the relay link mechanism 219. By rotating integrally, the rectilinear relay rod 233 moves backward, and the first rectilinear swing arm 232, the lateral support shaft 230, and the second rectilinear swing arm 234 are arrows opposite to the previous arrows. Rotates integrally in the SE direction.

  Then, the rectilinear second swing arm 234 pushes down the rectilinear interlocking rod 236 by pivoting movement in the arrow SE direction, so that the rectilinear operation arm 235 and hence the rectilinear pivot shaft 225 are moved in the arrow SF direction (reverse increase). It rotates in the speed direction (or forward deceleration direction). As a result, the traveling machine body 1 performs the reverse operation in proportion to the backward tilting operation amount of the main transmission lever 131.

  On the other hand, the turning link mechanism 226 includes a turning cylinder 241 that is rotatably fitted to a projecting portion of the lateral support shaft 230 from the support cylinder 229 and a turning turning arm that protrudes from the turning inner shaft 223. 242 and a pivoting relay rod 244 connecting the substantially rod-shaped first swinging arm 243 projecting from the rotating cylinder 241 and a second swinging arm 245 for pivoting projecting from the rotating cylinder 241. And a turning interlocking rod 247 that connects the turning operation arm 246 attached to the turning shaft 227 for turning.

  One end portion (the front end portion in the embodiment) of the turning relay rod 244 is pivotally attached to the turning arm 242 on the turning inner shaft 223 side so as to be turnable by a longitudinally attached pivot pin 248. . The other end portion (rear end portion in the embodiment) of the turning relay rod 244 pivots to the turning first swing arm 243 on the turning cylinder 241 side via a left and right laterally attached pivot pin 249. It is worn.

  One end portion (upper end portion in the embodiment) of the turning interlocking rod 247 is pivotally attached to the second swinging arm 245 for turning on the side of the turning cylinder 241 so as to be turnable by a pivoting pin 250 facing left and right laterally. Yes. The other end portion (the lower end portion in the embodiment) of the turning interlocking rod 247 is pivotally attached to the turning operation arm 246 on the turning turning shaft 227 side via a pivoting pin 251 that is oriented in the front-rear and lateral directions. ing.

  For example, when the steering handle 10 is rotated to the left with the main transmission lever 131 tilted forward, the mechanical switching means 220 is connected to the turning inner shaft 223 and the turning turning arm via the handle shaft 92. By rotating 242 integrally in the direction of the arrow TA, the turning relay rod 244 is pulled forward, and the turning first swing arm 243, the turning cylinder 241 and the turning second swing arm 245 are moved. It rotates integrally in the direction of arrow TB around the lateral support shaft 230.

  Then, the second swing arm 245 for swinging raises the interlocking interlocking rod 247 by the rotational movement in the arrow TB direction, so that the swing operation arm 246 and hence the pivot shaft 227 for swinging are moved in the direction of the arrow TC (forward leftward rotation). Rotate in the rotation direction). As a result, the traveling machine body 1 performs a left turn operation in proportion to the amount of leftward turning operation of the steering handle 10.

  In this case, the straight link mechanism 224 causes the straight rotation shaft 225 to move in the direction of the arrow SF (forward deceleration direction) in proportion to the amount of leftward rotation of the steering handle 10 by the action of the mechanical switching means 220. ), And the forward turning speed of the traveling machine body 1 is decelerated corresponding to the turning radius at that time.

  On the other hand, when the steering handle 10 is rotated to the right while the main transmission lever 131 is tilted forward, the mechanical switching means 220 is connected to the turning inner shaft 223 and the turning rotation via the handle shaft 92. By rotating the moving arm 242 integrally in the direction of the arrow TD, the turning relay rod 244 moves rearward, and the first turning arm 243 for turning, the turning cylinder 241 and the second turning arm for turning. 245 rotates integrally in the direction of arrow TE opposite to the previous direction.

  Then, the second swing arm 245 for turning pushes down the turning interlocking rod 247 by the turning movement in the direction of the arrow TE, so that the turning operation arm 246 and consequently the turning shaft 227 for turning is moved in the direction of the arrow TF (forward right) It turns in the turning direction. As a result, the traveling machine body 1 performs a right turn operation in proportion to the amount of rightward turning operation of the steering handle 10.

  Also in this case, the straight link mechanism 224 causes the straight rotation shaft 225 to move in the direction of arrow SF (forward deceleration) in proportion to the amount of rotation of the steering handle 10 in the right direction by the action of the mechanical switching means 220. The forward turning speed of the traveling machine body 1 is decelerated corresponding to the turning radius at that time.

  When the steering handle 10 is turned left and right with the main transmission lever 131 tilted rearward, the operations of the turning link mechanism 226 and the rectilinear link mechanism 224 are opposite to those described above. In other words, the operations of both link mechanisms 226 and 224 at the time of forward left turn are the same as those at the time of reverse right turn, while the operations of both link mechanisms 226 and 224 at the time of forward right turn are the same as those at the time of reverse left turn. Is set to

(5). Next, the various operation means arranged in the control unit 9 will be described mainly with reference to FIGS. 9 to 11.

  A vertically long steering column 90 and a front panel body 91 extending horizontally from the steering column 90 are disposed in front of the control seat 11 in the control unit 9. A round steering handle 10 for changing the traveling (turning) direction and the turning speed of the traveling machine body 1 is attached to a handle shaft 92 (see FIGS. 9 and 10) protruding upward from the steering column 90. ing.

  When the turning operation position of the steering handle 10 is in a neutral position N (also referred to as a straight-ahead position, see FIG. 10), the manual swing valve 202 of the hydraulic circuit 190 is maintained in a neutral state, and the manual swing valve 202 is The supply of hydraulic oil to the revolving cylinder 201 is stopped. For this reason, the traveling machine body 1 does not execute a turning operation in proportion to the amount of turning operation of the steering handle 10.

  In this case, if the main transmission lever 131 and the sub transmission lever 132 described later are operated to a position other than the neutral position, the electromagnetic rectilinear valve 214 of the hydraulic circuit 190 is switched, and the steering brake means 167 operates. In addition, the turning motor shaft 68 of the second hydraulic motor 153 is braked, and the power transmission from the turning motor shaft 68 to the differential gear mechanism 86 is cut off by the operation of the steering clutch means 169.

  Then, only the rotational power from the straight traveling motor shaft 67 is transmitted to the drive wheels 25 of the left and right traveling crawlers 2 at the same rotational speed in the same direction via the auxiliary transmission mechanism 85 and the differential gear mechanism 86. Therefore, the traveling machine body 1 is excellent in the straight running stability.

  When the turning operation position of the steering handle 10 is out of the neutral position N, hydraulic oil is supplied to the turning cylinder 201 by the switching operation of the manual turning valve 202, and the traveling machine body 1 turns the steering handle 10. A turning motion is executed in proportion to the operation amount.

  Needless to say, when the hand is released from the steering handle 10, the steering handle 10 automatically returns to the neutral position N by the action of a return means such as a spring (not shown).

  In the embodiment, the rotatable range of the steering handle 10 is set to an angle range of about 135 ° to the left and right across the neutral position N (see FIG. 10).

  In the steering column 90, the rotation position sensor 93 as a rotation detection means for detecting the rotation operation position (or the rotation operation amount) of the steering handle 10 and the steering handle 10 are in the neutral position N. A rectilinear sensor 99 is provided in association with the handle shaft 92 for detecting whether or not the handle shaft 92 exists. The rotation position sensor 93 of the embodiment is of a rotary encoder type or a rotary potentiometer type.

  A center panel body 95 having a liquid crystal display device 96 and the like is disposed inside a substantially annular handle wheel portion 94 in the steering handle 10. Since the center panel body 95 is fixed only to the steering column 90 and is not connected to the steering handle 10, even if the steering handle 10 is rotated, the center panel body 95 and thus the liquid crystal display device 96 are also operated. Does not move, and the screen is always easy to see from the operator.

  A steering switch 100 as a manual input means is provided on the upper surface of the grip portion on one of the left and right sides (right side in the embodiment) of the handle wheel portion 94. The steering switch 100 is a so-called cross-direction switch configured to be operable in the front-rear and left-right directions (cross direction).

  The steering switch 100 according to the embodiment forcibly lifts the cutting unit 3 to a height position necessary for changing the direction of the traveling machine body 1 at the headland (binge) while pushing the steering switch 100 forward. And a forced setting operation for forcibly lowering the cutting unit 3 to a predetermined cutting height position can be executed while the button is pushed backward.

  Such a forward / backward pushing operation is allowed only when the turning operation position of the steering handle 10 is at the neutral position N. That is, if the steering switch 100 is pushed forward or backward in this state, a forced lift operation or a forced set operation is executed.

  On the other hand, while the steering switch 100 is being pushed to the left or right, the electromagnetic automatic steering valve 203 (see FIGS. 8 and 12) of the hydraulic circuit 190 is excited by the excitation of the left or right steering solenoids 204 and 205. By switching operation, the traveling machine body 1 is configured to be able to make a slight turn (fine correction) left or right.

  Although details will be described later, in principle, the left / right pushing operation on the steering switch 100 is permitted when a selection adjustment switch 260 (see FIGS. 9 and 11) described later is in the on state, and the selection adjustment switch 260 is in the off state. When this happens, the operation becomes invalid (does not work).

  That is, even if the steering switch 100 is pushed left or right when the selection adjustment switch 260 is in the off state, the traveling machine body 1 does not turn slightly (finely correct) left or right.

  Here, “invalidate the left / right push operation of the steering switch 100 (does not function)” means that the electromagnetic automatic steering valve 203 of the hydraulic circuit 190 is turned on when the steering switch 100 is pushed left or right. It is an expression (meaning) including maintaining the neutral state and disabling the pushing operation of the steering switch 100 in the left-right direction.

  In the embodiment, when the selection adjustment switch 260 is in the off state, the electromagnetic automatic steering valve 203 of the hydraulic circuit 190 is maintained in the neutral state.

  Needless to say, when the finger is released from the steering switch 100, the steering switch 100 automatically returns to its neutral position.

  In addition, a horn switch 103 for performing an operation of sounding the horn 102 (horn, see FIG. 12) is provided on the upper surface of the grip portion on the other side (left side in the embodiment) of the handle wheel portion 94 (see FIG. 9 and FIG. 9). (See FIG. 10).

  On the left and right front panel bodies 91, a plurality of various operation switches and setting dials are arranged. For example, an automatic cutting height switch 104, a cutting height setting dial 105, a sorting adjustment dial 106, an automatic steering switch 107, and the like are disposed on the left front panel body 91. The automatic cutting height switch 104 is for operating on / off of automatic cutting height control for maintaining the cutting unit 3 at a predetermined cutting height position. The cutting height setting dial 105 is used to set and operate the cutting height position during automatic cutting height control. The sorting adjustment dial 106 is for adjusting the sorting state of the grains in the sorting device 20.

  The automatic steering switch 107 is for operating on / off of the automatic steering control that causes the traveling machine body 1 to travel along the row of planted culms C in the field. Note that the automatic steering switch 107 according to the embodiment is set so that the automatic steering control is not executed even if the automatic steering switch 107 is in the on state if the selection adjustment switch 260 described later is in the off state.

  On the right front panel body 91, an automobile speed switch 108, an automatic horizontal switch 109, an inclination setting dial 110, an automatic handling depth switch 111, and the like are arranged. The vehicle speed switch 108 is for operating on / off of vehicle speed control for decelerating the vehicle speed when the engine 12 is overloaded and maintaining the rotational drive of the mowing unit 3 and the threshing unit 6 constant. The automatic horizontal switch 109 is for operating on / off of automatic horizontal control for maintaining the traveling machine body 1 in a horizontal horizontal posture. The tilt setting dial 110 is for setting and operating the left and right tilt angle of the traveling machine body 1. The automatic handling depth switch 111 is for operating on / off of the automatic handling depth control for maintaining the handling depth position of the harvested cereal mash relative to the threshing unit 6 at a predetermined position.

  Each of the switches 104, 107, 108, 109, and 111 is a push switch (momentary switch) that generates one ON pulse signal when pressed once, and is of a non-locking type. When the switch 104, 107, 108, 109, 111 is pressed once to enter the switch, the switch lamps 114, 117, 118, 119, 121 above it are lit, and the switch is pressed again to turn off the switch. In this case, the switch lamps 114, 117, 118, 119, 121 are configured to be turned off.

  On one side of the control seat 11 (left side in the embodiment), a side panel body 130 that is long in the front-rear direction is disposed. On the side panel body 130, a selection adjustment switch 260, a main transmission lever 131, a sub transmission lever 132, and a clutch lever 133 are arranged in order from the front.

  The selection adjustment switch 260 is basically for selecting whether or not the steering switch 100 can be pressed in the left-right direction.

  The selection adjustment switch 260 of the embodiment is a rotary switch that executes switching to a predetermined circuit by rotating the knob 261. In this case, the rotary operation position of the knob 261 is configured to be changed in three stages in the range from the left end (OFF) to the right end (always ON) in FIG.

  If the operator sets the knob 261 to the “OFF” display at the left end of FIG. 11 when the cutting clutch 82 is in the engaged state, the selection adjustment switch 260 is turned off, and the left / right push operation on the steering switch 100 becomes invalid. (Does not work).

  When the knob 261 is set to the “always on” display at the right end of FIG. 11, the selection adjustment switch 260 is always turned on, and the left and right pushing operations on the steering switch 100 are always performed regardless of the turning operation of the steering handle 10. Permissible.

  Therefore, if both the steering handle 10 and the steering switch 100 are operated in this state, both the manual swing valve 202 and the electromagnetic automatic steering valve 203 of the hydraulic circuit 190 are switched to operate the steering handle 10. The turning operation of the traveling machine body 1 in the left-right direction is executed by the sum of the turning operation amount corresponding to the turning operation amount and the minute turning operation amount corresponding to the pressing operation amount of the steering switch 100.

  In the knob setting range between the “OFF” display and the “always ON” display, the rotation operation position of the knob 261 can be changed continuously (analog) or stepwise (digital) from the left side to the right side.

  The rotational operation position of the knob 261 within the range indicates the rotation limit of the steering handle 10 when the left and right pushing operation of the steering switch 100 is permitted (validated).

  In this case, if the turning operation position of the steering handle 10 is within a predetermined set angle range from the neutral position N to the left and right (within the setting area AS shown in FIG. 10), the left and right pushing operation of the steering switch 100 is allowed. Is done. If the turning operation position of the steering handle 10 is out of the setting area AS, the left / right pushing operation of the steering switch 100 becomes invalid.

  The setting area AS of the embodiment can be set within an angle range of 0 ° to 20 ° (total 0 ° to total 40 °) from side to side with the neutral position N in between.

  As is clear from the above description, the selection adjustment switch 260 according to the embodiment has not only a function of selecting whether or not the steering switch 100 can be pushed in the left-right direction, but also the steering handle 10 when allowing the pushing operation. It also has a function of setting a rotation limit in advance. In other words, the selection adjustment switch 260 of the embodiment also functions as a range setter described in the claims. Further, “when the selection adjustment switch 260 is in the on state” means a state in which the knob 261 is set to “always ON” or within the knob setting range.

  By the way, regarding the selection adjustment switch 260, if the cutting clutch 82 as the working clutch is in the disengaged state, the left / right pushing operation on the steering switch 100 is invalidated regardless of whether the selection adjustment switch 260 is on or off. Has been.

  When the cutting clutch 82 is in the disengaged state, the clutch lever 133 is tilted to the left end position of the left and right groove portions 135a in the guide groove 135, and the clutch lever 133 is tilted to this position when traveling on the road. It is when it is in a non-agricultural work state, such as crossing over a straw or when it is not during cutting and threshing work.

  For this reason, even if the steering switch 100 is accidentally pushed left and right during non-farm work such as traveling on the road, the turning motion of the traveling machine body 1 by the steering switch 100 is executed as long as the cutting clutch 82 is not engaged. Not.

  A selection adjustment switch lamp 262 for alerting the operator is provided near the selection adjustment switch 260 on the side panel body 130. The selection / adjustment switch lamp 262 is configured to light up in a state in which the left / right pushing operation of the steering switch 100 is permitted, and to be turned off in a state in which the pushing operation is invalid.

  On the other hand, the main speed change lever 131 on the side panel body 130 is for continuously changing the forward, stop, reverse, and vehicle speed of the traveling machine body 1. The main transmission lever 131 is configured to tilt forward and backward along a guide groove 134 that is crank-shaped in plan view in the side panel body 130.

  When the main transmission lever 131 is tilted forward from a neutral position (stop position) in a substantially vertical posture, the traveling machine body 1 moves forward. The forward speed of the traveling machine body 1 increases as the tilt angle of the main transmission lever 131 forward increases. Conversely, when the main transmission lever 131 is tilted backward from the neutral position, the traveling machine body 1 moves backward. The reverse speed of the traveling machine body 1 increases as the tilt angle of the main transmission lever 131 to the rear increases.

  The sub-transmission lever 132 changes the sub-transmission mechanism 85 of the hydraulic drive device 62 according to the working state, and sets the output and the rotational speed of the hydraulic drive device 62 to three speed stages, low speed, high speed, and neutral. It is for holding. The auxiliary transmission lever 132 is also configured to tilt forward and backward.

  The clutch lever 133 is a combination of a lever for power cutting operation of the reaping portion 3 and a lever for power cutting operation of the threshing portion 6, and is substantially L-shaped in plan view in the side panel 130. It is configured to be tiltable in the left and right and front and rear directions along the guide groove 135.

  When the clutch lever 133 of the embodiment is tilted to the left end position of the left and right groove portions 135a in the guide groove 135, both the cutting clutch 82 and the threshing clutch 71 (see FIG. 6) are in a disconnected state, and the right end position (front and rear groove portions 135b) of the left and right groove portions 135a. The threshing clutch 71 alone is engaged when tilted to the rear end position), and the clutches 82 and 71 are both engaged when tilted to the front end position of the front and rear groove 135b.

(6). Configuration of Control Means Next, a configuration for executing the alignment operation and automatic steering control of the traveling machine body 1 will be described with reference to FIG.

  Although not shown in detail, a controller 140 such as a microcomputer as a control means includes a central processing unit (CPU) for executing various arithmetic processes and controls, and a read-only memory (for storing control programs and data). ROM), read / write memory (RAM) as needed to temporarily store control programs and data, clocks as timer functions, and input / output interfaces for exchanging data with input / output devices (sensors, actuators, etc.) (Not shown).

  The input interface of the controller 140 includes a rotation position sensor 93 as a rotation detection unit of the steering handle 10, a straight-ahead sensor 99, a steering switch 100 as a manual input unit, a horn switch 103, a main transmission lever 131, and a sub transmission lever. 132, clutch lever 133, automatic cutting height switch 104, cutting height setting dial 105, sorting adjustment dial 106, automatic steering switch 107, automobile speed switch 108, automatic horizontal switch 109, inclination setting dial 110, automatic handling depth A switch 111, a power switch 136 for turning on and off the entire combiner, left and right steering sensors 50 and 51, left and right ultrasonic sensors 56, a lift position sensor 57, a selection adjusting switch 260 as a selection means, and the like. Each is connected.

  On the other hand, the output interface of the controller 140 drives left and right steering solenoids 204 and 205 for switching the electromagnetic automatic steering valve 203, a linear solenoid 214 for switching the electromagnetic linear valve 214, and a cutting clutch actuator. Cutting drive circuit 137 for driving, threshing drive circuit 138 for driving threshing cylinder 208, lifting drive circuit 139 for driving hydraulic cylinder 4, switch lamps 114, 117, 118, 119, 121, selection adjustment switch A lamp 262, a liquid crystal display device 96, a horn 102 (horn), and the like are connected to each other.

(7). Mode of Automatic Steering Control Next, an example of automatic steering control of the traveling machine body 1 will be described with reference to the flowchart shown in FIG. Here, it is assumed that the main transmission lever 131 is tilted to a position other than the neutral position, and the auxiliary transmission lever 132 is tilted to a low speed position.

  First, following the start, it is determined whether or not the clutch lever 133 is at the front end position of the front and rear groove part 135b in the guide groove 135 (power connection position to the cutting part 3), that is, whether or not the cutting clutch 82 is engaged. (Step S1).

  When the clutch lever 133 is at a position other than the front end position of the front / rear groove portion 135b in the guide groove 135 and the cutting clutch 82 is in a disengaged state (S1: NO), it is under non-farm work such as traveling on the road. The process proceeds to step S4.

  When the clutch lever 133 is at the front end position of the front / rear groove 135b in the guide groove 135 and the cutting clutch 82 is in the engaged state (S1: YES), the cutting and threshing operation is being performed (farming operation). Therefore, in the next step S2, the detection value of the rotation position sensor 93 and the rotation operation position of the selection adjustment switch 260 are read, and then it is determined whether or not the selection adjustment switch 260 is in the on state (step S3). .

  In step S3, when the selection adjustment switch 260 is in the off state (the state where the knob 261 is set to “OFF” display, S3: YES), then, the straight travel provided in relation to the handle shaft 92 of the steering handle 10 is performed. It is determined whether or not the sensor 99 is in the on state (step S4).

  If the rectilinear sensor 99 is in the on state (S4: YES), since the steering handle 10 is in the neutral position N (not operated to rotate), the electromagnetic rectilinear valve 214 of the hydraulic circuit 190 is automatically switched. When the steering brake means 167 is turned on, the turning motor shaft 68 of the second hydraulic motor 153 is braked, and when the steering clutch means 169 is turned off, the turning motor shaft 68 is changed to the differential gear mechanism 86. The transmission of power toward is cut off (step S5). In other words, the operation of the steering brake unit 167 and the steering clutch unit 169 sets the state in which power transmission from the turning HST transmission mechanism 64 to the differential gear mechanism 86 is blocked.

  Then, the manual transmission valve 192 of the hydraulic circuit 190 is actuated based on the amount of tilting operation of the main transmission lever 131, and the straight traveling operation of the traveling machine body 1 is executed by the rotational power from the straight traveling HST transmission mechanism 63 (step S6). ), Then return.

  On the other hand, if the rectilinear sensor 99 is in the off state (S4: NO), the steering handle 10 is rotated, so that the electromagnetic rectilinear valve 214 of the hydraulic circuit 190 is automatically switched to operate the steering brake means. The turning motor shaft 68 is braked by the turning operation of 167, and the power transmission from the turning motor shaft 68 to the differential gear mechanism 86 is enabled by the turning-on operation of the steering clutch means 169 (step) S7). In other words, the operation of the steering brake unit 167 and the steering clutch unit 169 allows the power transmission from the turning HST transmission mechanism 64 to the differential gear mechanism 86.

  Then, the manual turning valve 202 of the hydraulic circuit 190 is operated based on the amount of turning operation of the steering handle 10, and the turning operation of the traveling machine body 1 in the left-right direction is executed (step S8), and then the process returns.

  Returning to step S3, when the selection adjustment switch 260 is in the on state (the state where the knob 261 is set to “always ON” or within the knob setting range, S3: YES), the adjusting operation and the automatic operation of the traveling machine body 1 are performed. Since the direction control is executed, similarly to the case of step S7, the electromagnetic rectilinear valve 214 of the hydraulic circuit 190 is automatically switched and operated by the steering brake means 167 and the steering clutch means 169. The power transmission from the turning HST transmission mechanism 64 to the differential gear mechanism 86 is allowed (step S9).

  Next, is the rotation operation position of the steering handle 10 detected by the rotation position sensor 93 within a predetermined set angle range (within the setting area AS shown in FIG. 10) to the left and right across the neutral position N? It is determined whether or not (step S10).

  In step S10, when the turning operation position of the steering handle 10 is out of the setting area AS (S10: NO), the process proceeds to step S8 described above. That is, the manual turning valve 202 of the hydraulic circuit 190 is operated based on the turning operation amount of the steering handle 10 to execute the turning operation of the traveling machine body 1 in the left-right direction, and then the process returns.

  In step S10, when the turning operation position of the steering handle 10 is within the setting area AS (S10: YES), since the steering handle 10 is not being turned, the steering switch 100 is then turned on. It is determined whether or not the operation has been performed in the left or right direction (step S11).

  When the steering switch 100 is operated in the left direction (S11: left), the automatic operation valve 203 of the hydraulic circuit 190 is automatically switched to perform the alignment operation for slightly turning the traveling machine body 1 in the left direction. Execute (step S12), and then return. Further, when the steering switch 100 is operated to the right (S11: right), the electromagnetic automatic steering valve 203 of the hydraulic circuit 190 is automatically switched to perform a condition for slightly turning the traveling machine body 1 to the right. The operation is executed (step S13), and then the process returns.

  When the steering switch 100 is not operated in either the left or right direction (S11: OFF), it is then determined whether or not the automatic steering switch 107 in the control unit 9 is turned on (step S14).

  If the automatic steering switch 107 is in the OFF state (S14: NO), the process returns to the above-described step S4, and then the straight traveling operation (step S6) of the traveling machine body 1 based on the tilting operation amount of the main transmission lever 131 or the steering A turning operation (step S8) in the left-right direction of the traveling machine body 1 based on the turning operation amount of the handle 10 is executed, and the process returns.

  If the automatic steering switch 107 is in the on state (S14: YES), the controller 140 determines that the traveling machine body 1 is in a state in which automatic steering is possible (straight-running state), and the left and right steering sensors in the subsequent steps. In accordance with the detection information of 50 and 51, automatic steering control is performed to cause the traveling machine 1 to travel along the planted culm C row in the field (steps S15 to S18).

  In this case, first, in step S15, it is determined whether only the left steering sensor 50 is in the on state. When the above condition is satisfied with respect to the left steering sensor 50 (S15: YES), the electromagnetic automatic steering valve 203 of the hydraulic circuit 190 is switched to execute a minute turning operation of the traveling machine body 1 in the left direction. (Step S16), and then returns.

  When the above condition is not satisfied for the left steering sensor 50 (S15: NO), it is then determined whether only the right steering sensor 51 is in the on state (step S17). When the above-mentioned conditions are satisfied for the right steering sensor 51 (S17: YES), the electromagnetic automatic steering valve 203 of the hydraulic circuit 190 is switched to execute a minute turning operation of the traveling machine body 1 in the right direction. (Step S18), and then returns.

  When the above condition is not satisfied for the right steering sensor 51 (S17: NO), the process returns to step S15 to wait as it is. Then, the above control is repeated. As can be seen from this control mode, in the embodiment, the pushing operation (alignment operation) of the steering switch 100 in the left-right direction is processed in preference to the automatic steering control of the traveling machine body 1.

  As is apparent from the above description, according to the combine of the embodiment, the selection adjustment switch 260 for selecting whether or not the steering switch 100 can be pushed in the left-right direction is provided. In this case, even if the steering switch 100 is erroneously pushed in the left-right direction, the steering switch 100 does not function, and the micro-turning motion of the traveling machine body 1 is not executed.

  For this reason, the steering switch 100 can be operated while holding the handle wheel portion 94 of the steering handle 10. However, the risk that the traveling machine body 1 turns in an unexpected direction can be reduced, and the driving safety is excellent. ing.

  In addition, if the selection adjustment switch 260 is turned off, the power transmission from the turning HST transmission mechanism 64 to the differential gear mechanism 86 can be prevented by the action of the steering brake means 167 and the steering clutch means 169. Therefore, when the steering handle 10 is not rotated, the straight traveling stability of the traveling machine body 1 is improved.

  In the embodiment, if the reaping clutch 82 is in the disengaged state, the left / right pushing operation on the steering switch 100 becomes invalid regardless of whether the selection adjustment switch 260 is on or off.

  For this reason, even if the operator forgets to turn off the selection adjustment switch 260 at the time of non-farm work such as traveling on the road, as long as the cutting clutch 82 is in the disengaged state, the vehicle body 1 is turned slightly by the steering switch 100. The action is not performed. Therefore, the risk that the traveling machine body 1 is inadvertently turned to an unexpected direction can be reliably suppressed, and traveling safety is further enhanced.

  Further, when the selection adjustment switch 260 is in the off state, when the turning operation position of the steering handle 10 is out of the neutral position N, the steering brake means 167 and the steering clutch means 169 act as follows. Power transmission from the turning HST transmission mechanism 64 to the differential gear mechanism 86 is allowed.

  Therefore, power can be transmitted from the turning HST transmission mechanism 64 to the differential gear mechanism 86 automatically in the course of the turning operation of the steering handle 10 without operating the selection adjustment switch 260. You can switch to the state. Therefore, the operation burden on the operator can be reduced.

  Further, when the selection adjustment switch 260 is in the on state, when the rotation operation position of the steering handle 10 is out of the setting area AS, the left / right pushing operation on the steering switch 100 is invalid.

  For this reason, for example, even when the steering switch 100 is accidentally touched when changing the direction of the traveling machine body (normal turning) on the headland (border) in the field, the steering is performed regardless of whether the selection adjustment switch 260 is turned on or off. The minute turning movement of the traveling machine body 1 by the switch 100 is not executed. Therefore, in this respect as well, it is possible to reduce the operation burden on the operator and to contribute to further improvement in traveling safety.

  The selection adjustment switch 260 according to the embodiment not only has a function of selecting whether or not the steering switch 100 can perform a left / right push operation, but also a rotation limit of the steering handle 10 when the push operation is permitted (validated). Since it also has a function to be set in advance, the rotation limit of the steering handle 10 when the push operation functions can be changed and adjusted arbitrarily and easily by rotating the selection adjustment switch. For this reason, the operability of the steering handle 10 and the steering switch 260 can be improved.

(8). Others The present invention is not limited to the above-described embodiment, and can be embodied in various forms. For example, the present invention is not limited to the above-described combine, and can be widely applied to work vehicles such as farm work machines such as tractors and special work vehicles such as crane cars.

  In addition, a selection unit having a function of selecting whether or not the steering switch 100 can be pushed in the left-right direction, and a range setting unit having a function of presetting a turning limit of the steering handle 10 when the pushing operation is permitted. May be provided separately.

  Further, the selection means may select only whether or not the steering switch 100 can be pressed in the left-right direction. In this case, the selection means may be, for example, a push switch or a momentary switch.

  In addition, the structure of each part is not limited to embodiment of illustration, A various change is possible in the range which does not deviate from the meaning of this invention.

It is a side view of a combine. It is a top view of a combine. It is a schematic plan view of the front part in a cutting part. It is front explanatory drawing of a traveling machine body front part. It is a skeleton figure of a power transmission system. It is a skeleton figure of the power transmission system in a mission case. It is a hydraulic circuit diagram of a combine. It is explanatory drawing which shows typically the connection relation of the main speed-change lever, a steering handle, and a hydraulic drive device. It is a top view of a control part. It is an enlarged plan view of a steering handle. It is a schematic explanatory drawing of a selection adjustment switch. It is a functional block diagram of a controller. It is a flowchart of automatic steering control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traveling machine body 2 Traveling crawler 9 as traveling part Steering part 10 Steering handle 11 Steering seat 12 Engine 13 Transmission case 60 Output shaft 62 Hydraulic drive device 63 Straight forward HST transmission mechanism 64 Turning HST transmission mechanism 65 Straight traveling pump Shaft 66 Turning pump shaft 67 Linear motor shaft 68 Turning motor shaft 72 Counter case 85 Sub-transmission mechanism 86 Differential gear mechanism 90 Steering column 92 Handle shaft 93 Rotation position sensor 94 as rotation detecting means Handle wheel portion 99 Linear sensor 100 Steering switch 130 as manual input means Side panel body 140 Controller 150 as control means First hydraulic pump 151 First hydraulic motor 152 Second hydraulic pump 153 Second hydraulic motor 167 Steering brake means as a transmission switching mechanism 169 Transmission Steering clutch means as conversion mechanism 179 charge pump 190 hydraulic circuit 214 solenoid straight valve 215 straight solenoid 216 brake cylinders 217 clutch cylinder 218 selected as the counter oil passage 260 selecting means adjusting switch 261 knob 262 selectively adjusting switch lamp

Claims (5)

It is configured to transmit the power of the engine mounted on the traveling machine body to the traveling part from the straight drive and turning hydraulic drive devices via the differential mechanism, while changing the traveling direction of the traveling machine body A steering wheel is provided with manual input means for finely adjusting the traveling direction of the traveling machine body.
A selection means for selecting whether or not the manual input means can be finely adjusted; and a transmission switching mechanism disposed between the turning hydraulic drive device and the differential mechanism. A work vehicle configured to allow or prevent power transmission from the turning hydraulic drive device to the differential mechanism in conjunction with a propriety selection operation. A working clutch for interrupting power transmission to a working unit provided in the traveling machine body;
When the working clutch is in a disengaged state, the fine adjustment operation of the manual input means is invalidated even if the selection means is in an on state in which fine adjustment operation of the manual input means is permitted. The work vehicle according to claim 1.   When the selection means is in a cut-off state that prohibits the fine adjustment operation of the manual input means, and the rotation operation position of the steering handle is out of the neutral position, the transmission switching mechanism moves the hydraulic pressure for turning. The work vehicle according to claim 1, wherein the work vehicle is configured to allow power transmission from a driving device to the differential mechanism.   When the selection means is in an entering state permitting fine adjustment operation of the manual input means, when the rotation operation position of the steering handle is out of a predetermined rotation angle range, the manual input means The work vehicle according to claim 1, wherein the work vehicle is configured to invalidate a fine adjustment operation.   The work vehicle according to claim 4, further comprising a range setter for presetting the predetermined rotation angle range.

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