JP2007247906A - Combined harvester and thresher - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce horsepower loss near a maximum speed, to relieve shock felt by a worker in switching a constant rate driving, and to improve handleability. <P>SOLUTION: In a working vehicle provided with a car speed constant rate mechanism 76 driving a travelling portion 2 and an operating portion 7 by variable-speed output of a hydraulic pump 38 of a hydraulic gear shift mechanism 40 at a speed lower than the maximum speed, and connecting an input side and an output side of the hydraulic gear shift mechanism 40 near the maximum speed, and a work constant rate mechanism 121 driving the working portion 7 at a constant rate, the working portion 7 is transferred from a car speed synchronization to constant rate driving before the working maximum speed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a work vehicle such as a combine, a tractor, or a construction vehicle in which a pair of left and right traveling crawlers are mounted and moved.

Conventionally, for example, in a combine equipped with left and right traveling crawlers, as shown in, for example, Japanese Patent Application Laid-Open No. 2004-151620, a traveling unit (traveling crawler) and a working unit (reaching unit) are driven by a shift output of a hydraulic pump of a hydraulic transmission mechanism What to do is known.
Japanese Patent Laid-Open No. 62-163826

  However, in a combine equipped with left and right traveling crawlers, the traveling unit (traveling crawler) and the working unit (cutting unit) are driven by the speed change output of the hydraulic pump of the hydraulic transmission mechanism at a speed below the highest speed. When the input side and output side of the hydraulic transmission mechanism are directly connected by the vehicle speed constant speed mechanism near the maximum speed or when the working part is driven at a constant speed, the rotational difference (speed difference) before and after the direct connection by the constant speed mechanism There are problems such as the possibility of shock.

  However, according to the present invention, the traveling unit and the working unit are driven by the shift output of the hydraulic pump of the hydraulic transmission mechanism at a speed lower than the highest speed, and the input of the hydraulic transmission mechanism near the highest speed. A working vehicle equipped with a vehicle speed constant speed mechanism that directly connects the output side and a work constant speed mechanism that drives the working portion at a constant speed, and the working portion is shifted from vehicle speed synchronization to constant speed driving before the highest working speed; did.

  According to the second aspect of the present invention, when the working unit is shifted from the vehicle speed synchronization to the constant speed driving, the traveling unit is shifted from the hydraulic speed change driving to the constant speed driving after increasing the vehicle speed.

  According to the third aspect of the present invention, when the traveling portion is switched from the constant speed drive to the hydraulic transmission by the deceleration of the vehicle speed from around the maximum speed, after the vehicle speed is further decelerated, the working portion is changed from the constant speed drive to the vehicle speed synchronization. I decided to switch.

  According to another aspect of the present invention, the traveling portion is driven by the shift output of the hydraulic pump of the hydraulic transmission mechanism at a speed lower than the highest speed, and the input side and the output side of the hydraulic transmission mechanism are directly connected near the highest speed. In a work vehicle having a vehicle speed constant speed mechanism, the output of the hydraulic motor of the hydraulic speed change mechanism is made free after the traveling portion is shifted from the hydraulic speed shift to the constant speed drive in the vicinity of the maximum speed.

  According to the first aspect of the present invention, the traveling unit and the working unit are driven by the shift output of the hydraulic pump of the hydraulic transmission mechanism at a speed equal to or lower than the highest speed, and at the input side of the hydraulic transmission mechanism near the highest speed. In a work vehicle equipped with a vehicle speed constant speed mechanism that directly connects the output side and a work constant speed mechanism that drives the work part at a constant speed, the work part is shifted from vehicle speed synchronization to constant speed drive before the highest work speed. With a structure that can work smoothly at a work speed synchronized with the motor, it can reduce the horsepower loss near the maximum speed, and the operator feels shock when switching the work part from vehicle speed synchronization to constant speed drive Shock can be relieved and handling can be improved.

  According to another aspect of the present invention, when the working unit is shifted from the vehicle speed synchronization to the constant speed driving, the traveling unit is shifted from the hydraulic shift driving to the constant speed driving after increasing the vehicle speed. After shifting to constant speed driving, the vehicle speed is increased to the vicinity of the maximum speed, and the traveling part is driven at a constant speed, so that the horsepower loss near the maximum speed can be reduced and the input side and output of the hydraulic transmission mechanism can be reduced. The shock felt by the operator, such as a shock when directly connecting the sides, can be alleviated, and the handling property can be improved.

  According to the third aspect of the present invention, when the traveling portion is switched from the constant speed drive to the hydraulic transmission by the deceleration of the vehicle speed from around the maximum speed, after the vehicle speed is further decelerated, the working portion is changed from the constant speed drive to the vehicle speed synchronization. It can reduce the shock felt by the operator, such as shock when switching the working part from constant speed drive to vehicle speed synchronization, or shock when releasing the direct connection between the input side and output side of the hydraulic transmission mechanism Can be improved.

  According to another aspect of the present invention, the traveling portion is driven by the shift output of the hydraulic pump of the hydraulic transmission mechanism at a speed lower than the highest speed, and the input side and the output side of the hydraulic transmission mechanism are directly connected near the highest speed. In a work vehicle equipped with a constant vehicle speed mechanism, the output of the hydraulic motor of the hydraulic transmission mechanism is adjusted freely after the traveling part is shifted from the hydraulic transmission to the constant speed drive near the maximum speed. With a structure that can run, it can reduce horsepower loss near the maximum speed, and can reduce the shock felt by the operator, such as shock when switching the traveling part from hydraulic speed change to constant speed drive, handling ease Can be improved.

  Embodiments of the present invention will be described below in detail with reference to the drawings. 1 is a perspective view of the entire combine, FIG. 2 is a right side view thereof, and FIG. 3 is an explanatory plan view thereof. In FIG. 1, 1 is a pair of left and right track frames on which a pair of left and right traveling crawlers 2 are installed. 4 is a threshing unit which is a threshing machine which has a feed chain 5 stretched to the left and incorporates a handling cylinder 6 and a processing cylinder, 7 is a pulling mechanism 8 and a cutting blade 9 and A mowing unit including the culm transporting mechanism 10, 11 is a hydraulic lifting cylinder that raises and lowers the mowing unit 7 via the mowing frame 12, 13 is a slaughter processing unit that faces the end of the sewage chain 14, and 15 is a threshing unit 4. A grain tank for carrying in the grain through a milling cylinder, 16 and 17 a discharge auger for carrying out the grain in the tank 15 to the outside of the machine, 18 a driving cabin provided with a driving operation handle 19 and a driver seat 20, 21 Is installed under the driving cabin 18 That an engine is configured to threshing continuously harvests culms.

  Further, as shown in FIGS. 4 to 8, a mission case 22 is disposed between the left and right traveling crawlers 2 on the front side of the machine base 3, the mission case 22 and the engine 21 are provided substantially in series, and the mission case 22 is provided. The driving force of the engine 21 is transmitted to the traveling crawler 2 via the left and right support bases 23 and 24 erected on the upper surface of the machine base 3 on the front side of the threshing unit 4, and the support bases 23 and 24 are cut through the cutting frame 12. The part 7 is provided so as to be movable up and down and laterally movable. Further, a counter case 25 is provided on the upper surface of the machine base 3 on the rear side of the support bases 23 and 24, and the driving force of the engine 21 is transmitted to the threshing unit 4 and the mowing unit 7 through the counter case 25.

  Further, the cabin front frame 26 is erected on the machine base 3 on the side of the transmission case 22, and the front portion of the step frame 27 of the cabin 18 is provided on the upper portion of the front frame 26 via the rotation fulcrum shaft 28. The cabin 18 is rotatably supported forward, and the left cabin rear frame 29 is erected on the right support 24 and the machine base 3 between the right cabin rear frame 30 erected on the machine base 3. An engine 21 is provided on the upper surface, and the engine 21 is covered with an engine room cover 31. Further, the upper parts of the left and right rear frames 29 and 30 are connected to each other by the cabin horizontal frame 32 above the cover 31, the hook lever 33 is provided on the cabin horizontal frame 32, and the rear portion of the step frame 27 of the cabin 18 is mounted on the horizontal frame 32. The hook lever 33 is detachably fixed and the horizontal connecting frame 34 is fixed between the right support 24 and the front frame 26, and the inclined connecting frame 35 is fixed between the horizontal connecting frame 34 and the horizontal frame 32. The frame rigidity is ensured by the connecting frames 34 and 35. In addition, an auger support 36 is connected to the left rear frame 29 to provide an auger rest 37 on the upper side, and the discharge auger 17 provided so as to be able to move up and down and turn is supported at the machine storage position of the auger rest 37.

  Further, as shown in FIGS. 9 to 14, the transmission case 22 for driving the traveling crawler 2 is provided with a pair of hydraulic traveling pumps 38 and a hydraulic traveling motor 39 to provide a hydraulic continuously variable transmission mechanism for traveling main transmission. A traveling speed change member 40 to be formed, and a turning member 43 which forms a hydraulic continuously variable transmission mechanism for turning by providing a pair of hydraulic turning pumps 41 and a hydraulic turning motor 42, are provided on the output shaft 44 of the engine 21. The pumps 38 and 41 are configured to be connected via an input shaft 45 of the mission case 22.

  Further, each drive wheel 49 of the left and right traveling crawler 2 is interlockedly connected to the motor shaft 46 of the traveling motor 39 via a sub-transmission mechanism 47 and a differential mechanism 48. Each planetary gear mechanism 50 includes a single sun gear 51, three planetary gears 52 that mesh with the outer periphery of the sun gear 51, and a ring gear 53 that meshes with these planetary gears 52. .

  The planetary gear 52 is rotatably supported by a free-wheeling shaft 54 of the sun gear 51 and a carrier 56 of an axle 55 on the same axis, so that the left and right carriers 56 are opposed to each other with the left and right sun gears 51 therebetween. Has internal teeth meshing with each planetary gear 52 and is rotatably supported on an axle 55. The axle 55 is extended to support a drive wheel 49.

  The traveling speed change member 40 controls forward / reverse rotation and rotational speed of the traveling motor 39 by changing the swash plate angle of the traveling pump 38. The traveling speed of the traveling motor 39 is controlled by the motor shaft 46 and the auxiliary transmission mechanism 47. The low-speed and high-speed gears 57 and 58, the brake shaft 59, and the branch shaft 60 are transmitted to the left and right ring gears 53 to rotate the left and right carriers 56. A parking brake 61 is provided on the brake shaft 59, and a cutting drive pulley 62 that transmits a rotational force to the cutting unit 7 is provided on the motor shaft 46 to drive the cutting unit 7 at a vehicle speed synchronization speed.

  As described above, the driving force of the traveling motor 39 transmitted to the ring gear 53 via the branch shaft 60 is transmitted to the left and right carriers 56 via the left and right planetary gear mechanisms 50, and the rotation transmitted to the left and right carriers 56. Is transmitted to the left and right drive wheels 49, respectively, so that the left and right traveling crawlers 2 are driven in the same direction and at the same speed.

  Further, the turning member 43 formed by the hydraulic continuously variable transmission mechanism for turning controls the forward / reverse rotation and the rotational speed of the turning motor 42 by changing the swash plate angle of the turning pump 41. A motor shaft 64 provided with 63, a clutch shaft 66 provided with a steering output clutch 65, and left and right input gears 67 and 68 that are always meshed with the left and right sun gears 51. The clutch shaft 66 is connected via the steering output clutch 65, and the left and right input gears 67 and 68 are connected to the clutch shaft 66 via the forward rotation gear 69 and the reverse rotation gear 70. Then, the rotational force of the motor 42 is transmitted to the right sun gear 51 via the forward rotation gear 69, and the rotation of the motor 42 is transmitted to the left sun gear 51 via the reverse rotation gear 70. The left sun gear 51 is reversely rotated (forward rotation) and the right sun gear 51 is rotated forward (reverse rotation) at the same left and right rotational speeds, and the left and right traveling crawlers 2 are driven in the reverse direction at the same speed.

  Thus, when the traveling motor 39 is driven in a state where the turning motor 42 is stopped and the left and right sun gears 51 are stationary, the rotation of the traveling motor 39 is transmitted to the left and right ring gears 53 at the same rotational speed, and the left and right planetary gears. The left and right traveling crawlers 2 are driven at the same rotational speed in the same direction in the left and right directions through the carrier 56 of the mechanism 50, and the vehicle body travels straight forward and backward. On the other hand, when the turning motor 42 is driven to rotate forward and reverse with the traveling motor 39 stopped and the left and right ring gears 53 stationary, the left planetary gear mechanism 50 rotates forward or reverse, and the right planetary gear mechanism 50. Rotates in the reverse or forward direction, drives the left and right traveling crawler 2 in the reverse direction, and turns the aircraft to the left or right. Further, by driving the turning motor 42 while driving the traveling motor 39, the aircraft turns left and right to correct the course, and the turning radius of the aircraft is determined by the output rotation speed of the turning motor 42. .

  Further, a fan shaft 71 is connected to the input shaft 45, and a cooling fan 72 of a radiator for cooling the engine 21 is driven by the fan shaft 71, and the pump shafts 73 and 74 of the traveling and swirling pumps 38 and 41 are connected to the pump shafts 73 and 74. The fan shaft 71 is connected via a gear group 75, the input shaft 45 is connected to the pumps 38 and 41, and the pump shaft 73 of the traveling pump 38 and the motor shaft 46 of the traveling motor 39 are connected to a constant speed clutch 76. When the constant speed clutch 77 is turned on and the constant speed clutch 76 is turned on, the pump shaft 73 and the motor shaft 46 are gear-connected via the constant speed shaft 77, and without the travel speed change member 40 being interposed, The rotation of the input shaft 45 is transmitted to the sub-transmission mechanism 47, the left and right traveling crawlers 2 are driven by the constant speed rotation of the engine 21, and the harvesting operation is performed by traveling at a substantially constant vehicle speed. I make. A charge pump 78 is provided on the swing pump shaft 74 and driven.

  Further, as shown in FIG. 15, a main transmission cylinder 80 for adjusting the output by changing the angle of the swash plate 79 of the traveling pump 38, a transmission valve 82 connected to the main transmission lever 81 and the steering handle 19, and a traveling pump. 38, a valve 83 for decelerating the output by a certain amount is provided, and the charge pump 78 is hydraulically connected to the main transmission cylinder 80 via the valves 82 and 83. The main transmission lever 81 switches the transmission valve 82, and the main transmission cylinder 80 is operated to change the angle of the swash plate 79 of the traveling pump 38, to change the rotational speed of the motor shaft 46 of the traveling motor 39 steplessly or to perform a traveling shift operation that reverses the rotation. The swash plate 7 is made proportional to the operation amount of the main transmission lever 81 by performing a feedback operation in which the transmission valve 82 is neutrally returned by the angle adjustment operation. The angle is varied, by varying the rotation speed of the traveling motor 39 to change the vehicle speed.

  Further, a sub-transmission cylinder 85 for adjusting the output by changing the angle of the swash plate 84 of the traveling motor 39 is provided, and the sub-transmission cylinder 85 is hydraulically connected to the charge pump 78 via the electromagnetic sub-transmission valve 86. When the engine is neutral, the auxiliary transmission cylinder 85 is short-circuited to the transmission case 22 which is an oil tank, the angle of the swash plate 84 of the traveling motor 39 is changed by the main circuit oil pressure, and the angle of the swash plate 84 is changed by switching the auxiliary transmission valve 86. The output of the traveling motor 39 is changed to a high speed or a low speed by forcibly changing.

  Further, a slewing cylinder 88 for adjusting the output by changing the angle of the swash plate 87 of the slewing pump 41 is provided, and is connected via the slewing valve 89 and the electromagnetic automatic steering valve 90 which are switched by being connected to the steering handle 19 and the main transmission lever 81. The charge pump 78 is hydraulically connected to the turning cylinder 88, the turning valve 89 is switched by the steering handle 19, the turning cylinder 88 is operated to change the angle of the swash plate 87 of the turning pump 41, and the motor shaft 64 of the turning motor 42 is changed. A left / right turning operation that changes the rotation speed steplessly or reversely is performed, and a feedback operation in which the turning valve 89 is neutrally returned by an angle adjustment operation of the swash plate 87 is performed. The angle of the swash plate 87 is changed proportionally, and the rotation speed of the turning motor 42 is changed to change the left / right turning angle.

  Further, when the main transmission lever 81 is operated to a position other than the neutral position and the steering handle 19 is operated other than the straight traveling, the hydraulic output of the traveling pump 38 is proportional to the operation direction and the operation amount of the main transmission lever 81. Increase / decrease, forward / reverse or increase / decrease the hydraulic motor 39 to change the forward / reverse speed (vehicle speed), and change the output of the swing pump 41 in proportion to the amount of operation of the main shift lever 81. Automatically reduces the turning radius and automatically increases the turning radius by low-speed side shifting, and the turning radius of the left and right traveling crawlers 2 is maintained substantially constant by constant operation of the steering handle 19 regardless of the traveling speed. To change the work travel speed and to correct the course so that the machine body is aligned with the uncut grain row. On the other hand, when the turning pump 41 output and the traveling pump 38 output are changed by the control of the valves 82 and 89 in proportion to the operation amount of the steering handle 19, the traveling speed is reduced when the turning radius (steering angle) is made small (large). The speed difference between the left and right traveling crawlers 2 is increased and the left and right traveling crawlers 2 are swung left and right while the vehicle speed is reduced in proportion to the vehicle speed. The direction is changed by spin-turning at, and the harvesting operation is carried out to continuously harvest and thresh grains. When the main transmission lever 81 is neutral, the swing valve 89 is maintained neutral regardless of the operation of the steering handle 19, the hydraulic output of the swing pump 41 is maintained at substantially zero, and the swing motor 42 is stopped.

  Further, as shown in FIGS. 14 to 22, the output shaft 44 of the engine 21 is projected on the front side and the rear side, the input shaft 45 is connected to the front side of the output shaft 44, and work is performed on the rear side of the output shaft 44. An output pulley 91 is provided, and a counter case 25 is provided on the upper surface of the machine base 3 in front of the threshing section 4 on the left side of the engine 21. The input pulley 92, the vehicle speed tuning pulley 93, the threshing pulley 94, the cutting pulley 95, and the sorting pulley 96 are countered. The case 25 is pivotally supported, and the input pulley 92 on the rear side of the case 25 is connected to the work output pulley 91 via a belt threshing clutch 97 to transmit the driving force of the engine 21 to the counter case 25. In addition, the vehicle speed tuning pulley 93 on the right side of the counter case 25 is connected to the cutting drive pulley 62 of the transmission case 22 via the idle pulley 99 on the front side of the right support base 24 and is erected on the front upper surface of the machine base 3. A cutting input case 101 is pivotally supported on the support bases 23 and 24, a cutting frame 12 is connected to the case 101, and the cutting unit 7 is rotated around the case 101 to move up and down. The cutting input pulley 103 is pivotally supported via the cutting input shaft 102, the cutting pulley 95 on the left side of the counter case 25 is connected to the cutting input pulley 103 with the belt 104, and the driving force is transmitted to each part of the cutting unit 7.

  Further, a threshing pulley 94 on the front side of the counter case 25 is connected to the driving input pulley 105 of the handling cylinder 6 with a belt 106, and a driving force is transmitted from the sorting pulley 96 to the sorting and swinging selection mechanism on the lower side of the handling cylinder 6, thereby threshing. While driving each part of the part 6, a feed chain input shaft 107 is provided on the left side surface of the counter case 25, and power is transmitted from the input shaft 107 to the drive sprocket 108 of the feed chain 5 that can move outward. Further, a discharge drive pulley 109 is provided on the front side of the grain tank 15, the pulley 109 is belt-connected to the work output pulley 91 via a discharge clutch 110, and the output of the engine 21 is transmitted to the discharge auger 17 to transfer the grain in the tank 15. Drain the grains.

  Further, the barrel input shaft 111 is pivotally supported on the counter case 25, the shaft 111 is extended in the front-rear direction, a threshing pulley 94 is provided on the front side of the shaft 111 outside the front surface of the counter case 25, and the rear surface of the counter case 25 An input pulley 92 is provided on the rear side of the outer shaft 111, and a constant rotational power of the engine 21 is input to the handling cylinder input shaft 111 to rotate at a constant speed. Further, a tuning input shaft 112 is pivotally supported on the right side of the counter case 25, a vehicle speed tuning pulley 93 is provided on the right side of the shaft 112 outside the right side of the counter case 25, and a belt is provided between the pulleys 62 and 93 via the idle pulley 99. 100 is tensioned, and the vehicle speed synchronization power is input from the mission case 22 to the counter case 25.

  Further, the counter case 25 includes a constant speed shaft 114 that is a counter shaft or a selection input shaft for connecting the bevel gear 113 on the right side to the handle cylinder input shaft 111 and a vehicle speed tuning shaft 115 provided substantially parallel to the front side of the shaft 114. A low-speed gear 117 and a high-speed gear 118 forming a cutting and shifting mechanism 116 are provided between the shafts 114 and 115, and each gear is supported by a cutting and shifting slider 119 that performs low-speed, neutral and high-speed cutting shifts. 117 and 118 are selectively engaged with the vehicle speed tuning shaft 115 to perform a cutting shift. Further, a one-way clutch 120 is provided on the tuning input shaft 112 to transmit the vehicle speed tuning rotational force of the tuning input shaft 112 to the gears 117 and 118, and the gear 117 transmits power from the vehicle speed tuning pulley 93 by the one-way clutch 120. The vehicle speed tuning shaft 115 is configured to rotate via 118.

  Further, a pouring gear 122 and a high speed cut gear 123 forming a cutting constant speed mechanism 121 are provided between the shafts 114 and 115, and the shafts 114 and 115 are switched by a switching slider 124 for pouring driving or high speed cutting driving of the cutting portion 7. The gears 122 and 123 are selectively engaged with each other, and the cutting unit 7 is poured and driven to convey the grain of the cutting unit 7 to the feed chain 5 regardless of the running state, while the cutting unit 7 is operated at high speed. It cuts and drives the cutting part 7 at a constant rotational speed faster than the maximum speed synchronized with the vehicle speed to cut the fallen cereal.

  Further, the left end of the constant speed shaft 114 is protruded to the lower rear side on the left side of the counter case 25, and the sorting pulley 96 is pivotally supported on the left end portion of the shaft 114. Further, the cutting transmission shaft 125 is pivotally supported on the lower front side on the left side of the counter case 25, the right side of the shaft 125 is connected to the vehicle speed tuning shaft 115 via the torque limiter 126, and the shaft 125 is projected to the left side of the counter case 25. A cutting pulley 95 is pivotally supported on the left end, a cutting drive shaft 127 is connected to the cutting input shaft 102 with a gear 128, and the cutting input pulley 103 is pivotally supported on the cutting drive shaft 127. A case of a gear 128 is provided on the base 23 via a fulcrum shaft 129 so as to be rotatable about the vertical axis, the left side of the cutting input case 101 is fixed to the case of the gear 128, and the gear 128 is provided in each case 101, A cutting power is input from the left end side of the cutting input shaft 102 via a cutting transmission shaft 130 which is inserted into the cutting frame 12 on the right end side of the case 101. While causing the driving of the reaper 7, the reaper 7 substantially horizontally to the fuselage left pivot shaft 129 around rotated move, the maintenance of each case 22, 25 near the inboard like.

  Further, the feed chain input shaft 107 is pivotally supported on the upper left part of the counter case 25, the input shaft 107 is connected to the chain 133 to a feed chain drive shaft 132 provided with a feed chain clutch 131, and the constant speed shaft 114 is rotated. Is provided with a feed chain transmission mechanism 134 that transmits the speed by changing the rotational speed of the vehicle speed tuning shaft 115, and the planetary gear mechanism 138 including the sun gear 135, the planetary gear 136, and the ring gear 137 forms the mechanism 134 so as to be continuously variable. In addition, the sun gear 135 is supported on the constant speed shaft 114 and the ring gear 137, which freely supports the constant speed shaft 114, is connected to the gear 139 to the vehicle speed tuning shaft 115, and the bearing 140, which supports the planetary gear 136, is fixed. The fast shaft 114 is supported in an idle manner, and the feed chain is The bearing body 140 is connected to the gear 141 via the clutch 131 to the feed chain drive shaft 132 to ensure the minimum rotation necessary for conveying the cereal, and the feed chain 5 speed is increased from the low constant rotation to the high rotation. It is configured so that it can be changed in synchronization.

  Further, a hydraulic cutting speed change cylinder 142 for operating the cutting speed change slider 119, a hydraulic cutting speed constant cylinder 143 for operating the switching slider 124, and a hydraulic threshing cylinder 144 for receiving the threshing clutch 97 are provided on the upper cover of the counter case 25. The vehicle speed constant speed valve 147 that operates the vehicle speed constant speed cylinder 146 that engages the constant speed clutch 76, the cutting speed change valve 148 that operates the cutting speed change cylinder 142, and the cutting setting. A mowing constant speed valve 149 for operating the speed cylinder 143 and a threshing valve 150 for operating the threshing cylinder 144 are hydraulically connected in parallel to the charge pump 78.

  Further, as shown in FIGS. 15, 23 to 28, the threshing clutch 97 is pivotally supported on the tension arm 151, and the tension arm 151 is pivotally supported on the support shaft 152 of the counter case 25 so that it can be bent. The piston rod 155 of the threshing cylinder 144 is connected to the tension arm 151 via the two links 153 and 154, and the threshing clutch 97 is engaged by the pushing (advancing) operation of the piston rod 155 to tension the belt 98. By the pulling (withdrawing) operation of the piston rod 155, the threshing clutch 97 is operated to loosen the belt 98. In addition, a spring 156 that elastically presses the threshing clutch 97 to the cut side is connected to the link 154, and a throttle valve 157 is provided on the return side of the oil passage on the piston rod 155 advancement side of the double-action type threshing cylinder 144. Is advanced at a slow speed to turn on the threshing clutch 97, while the piston rod 155 is retracted at a high speed to turn off the threshing clutch 97.

  As is clear from the above, in a work vehicle including a counter case 25 that is a transmission case that distributes the power from the engine 21 to the traveling crawler 2 that is the traveling unit, the threshing unit 4 that is the working unit, and the mowing unit 7. The oil passage base 145 forming a part of the case 25 is provided with a threshing clutch 97 as a working clutch or a plurality of hydraulic cylinders 142, 143, and 144 for working speed change, both inside or outside the counter case 25 The hydraulic cylinders 142, 143, and 144 can be used for switching, and the hydraulic switching structure can be made compact and maintenance can be improved. The pistons 160 and 161 of the hydraulic cylinders 142 and 143 for work shifting can be used as a counter case. 25, and the piston cylinder of the hydraulic cylinder 144 for the threshing clutch 97 The switch case 155 is externally mounted on the counter case 25, and a switching structure such as a gear shift or a clutch provided inside and outside the counter case 25 can be compactly arranged around the oil passage base 145 that is a part of the counter case 25. The support rigidity of the hydraulic cylinders 142, 143, and 144 with respect to the switching reaction force can be easily secured by attaching the oil passage base 145, and the assembling / removing property and the maintenance property can be improved.

  Further, the piston rod 155 of the hydraulic cylinder 144 for the threshing clutch 97 is connected to the belt clutch tension arm 151 forming the threshing clutch 97, and the tension force required for the belt clutch is increased by increasing the capacity of the hydraulic cylinder 144. The hydraulic cylinder 144 for the threshing clutch 97 is double-acted and both the on and off of the belt clutch are hydraulically operated. By increasing the capacity of the cylinder 144, the tension force necessary for the belt clutch can be sufficiently obtained, and the compactness and the improvement of the maintainability are performed. Further, the hydraulic cylinder 144 for the threshing clutch 97 is driven using the hydraulic charge pump 78, and the tension force is easily made by the hydraulic pressure of the charge pump 78, the diameter of the piston 155 of the hydraulic cylinder 144, and the tension arm 151 ratio. It is possible to determine and improve the maintainability by eliminating the need for tension adjustment, and to make the piston rod 155 roke of the hydraulic cylinder 144 for the threshing clutch 97 larger than the maximum extension amount of the belt 98. However, an appropriate tension force can be easily secured without adjusting the tension.

  Further, as shown in FIGS. 15, 27 to 32, the oil passage base 145 is detachably fixed to the upper surface of the counter case 25 with a bolt 158 to close the upper surface opening 159 of the counter case 25, and the oil passage base. 145, the valves 148, 149, 150 are fixed to the upper surface side, the cylinders 142, 143, 144 are fixed to the lower surface side of the oil passage base 145, and a threshing cylinder 144 is provided outside the counter case 25, The cutting speed change cylinder 142 and the fixed cutting speed cylinder 143 are installed in the counter case 25. In addition, the piston rods 160 and 161 protrude from opposite sides of the cylinders 142 and 143 in opposite directions, and the speed change arms 164 are provided on the arm bases 162 and 163 that form the rear lids of the cylinders 142 and 143. The fulcrum shafts 166 and 167 on one end side of the constant speed arm 165 are rotatably inserted from the lower side and supported, and the piston rods 160 and 161 are connected to the other end sides of the arms 164 and 165, respectively.

  In addition, a fork shaft 168 is provided in the counter case 25 so as to be rotatable around the axis substantially parallel to the vehicle speed tuning shaft 115, a speed change fork 169 for switching the cutting speed change slider 119, and a constant speed fork 170 for switching the change slider 124. The fork shaft 168 is provided to be slidable in the axial direction, and the pins 171 and 172 provided in the middle of the arms 164 and 165 are engaged with the forks 169 and 170, and the arms 164 and 165 are engaged with the forks. The piston rods 160 and 161 of the cylinders 142 and 143 are advanced or retracted by the control of the valves 148 and 149, and the arms 164 and 165 are swung around the fulcrum shafts 166 and 167. , Move the shift fork 169 from neutral to high speed or standard (low speed) output side Write, and configured to move the constant speed fork 170 from the neutral fast cut or cast into a rotary output side.

  14, 29, and 30, a back pressure rod 174 is fixed to the piston rods 160 and 161 via a piston head 173, and a ring-type retraction piston 175 is provided on the outer periphery of the back pressure rod 174. The back pressure rod 174 has a larger diameter than the piston rods 160 and 161 and a smaller diameter than the piston head 173, and the outer diameter of the retraction piston 175 is larger than the piston head 173, and the valves 148 and 149 are formed. Is neutral, the retraction piston 175 is brought into contact with the step 177 of the cylinders 142 and 143 by the A port 176 pressure oil of the charge pump 78, and the piston head 173 is retreated by the B port 178 pressure oil of the charge pump 78. The piston rods 160 and 161 are moved back to the neutral position by hydraulic pressure. To be supported. When the valves 148 and 149 are switched, the B port 178 is opened to the tank passage of the valves 148 and 149 so that the back pressure rod 174, the head 173, and the piston rods 160 and 161 are moved by the A port 176 pressure oil. On the other hand, by opening the A port 176 to the tank passage of the valves 148 and 149, the head 173, the back pressure rod 174, the retracting piston 175, and the piston rods 160 and 161 are retracted by the B port 178 pressure oil. Therefore, the arms 164 and 165 are fixed back to the neutral position in a pressurized state via the piston rods 160 and 161, and can be supported by returning the sliders 119 and 124 to the neutral position without providing a spring or the like. . Further, a lubrication port 179 is opened at the step 177 of the cylinders 142 and 143, and the port 179 is communicated with the A port 176 or the B port 178.

  As is apparent from the above, the piston rods 160 and 161 and the retracting piston 175 of the double-acting type hydraulic cutting speed change and cutting constant speed cylinders 142 and 143 are double-structured and are supported neutrally by applying pressure to both sides. The piston rods 160 and 161 and the retracting piston 175 can be held in the neutral position by hydraulic pressure by the neutral operation of the three-position switching valves 148 and 149, and the piston rods 160 and 161 protrude from one of the cylinders 142 and 143. The double-acting cylinders 142 and 143 can appropriately switch the three positions, can form a compact and reliable switching mechanism, and simplify the switching structure of one or both of the cutting speed change mechanism 116 and the constant speed mechanism 121. In addition, improve operability.

  Furthermore, as shown in FIG. 32, the fork 169/170 is supported by the detent ball 180 in a neutral position, and a rectangular hole-shaped transmission cam 181 having a vertical angle positioned in a direction perpendicular to the axial direction of the fork shaft 168 is provided. A boss portion of the constant-speed fork 170 is provided with a long-hole-type constant-speed cam 183 provided on the boss portion of the transmission fork 169 and having the pin 182 inserted through the fork shaft 168 and the transmission cam 181 and obliquely intersecting the fork shaft 168. The pin 184 is inserted through the fork shaft 168 and the constant speed cam 183. Then, when the speed change fork 169 is switched to the cutting standard (low speed) or high speed side, the pin 182 comes into contact with the apex portion of the speed change cam 181 in the axial direction of the fork shaft 168, and the fork shaft 168 rotates around the axis. The constant-speed fork 170 is supported in the neutral position. On the other hand, by switching the constant-speed fork 170 to the high-speed cut or flow-in rotation side, the pin 184 is pushed by the constant-speed cam 180 to rotate the fork shaft 168 around the axis, and in the direction perpendicular to the axis of the fork shaft 168 The pin 182 is brought into contact with the apex angle portion of the transmission cam 181 to prevent the transmission fork 169 from moving in the axial direction, thereby supporting the transmission fork 169 in the neutral position. In this way, the speed change fork 169 and the constant speed fork 170 are provided on one fork shaft 168, the operations of the forks 169 and 170 are mutually regulated by the speed change cam 181 and the constant speed cam 183, and the gear 117 by simultaneous switching is provided.・ Prevents the occurrence of biting such as 118, 122, and 123.

  As apparent from the above, in the combine including the cutting speed change mechanism 116 that changes the driving speed of the cutting unit 7 and the cutting constant speed mechanism 121 that drives the cutting unit 7 at a substantially constant speed, the cutting constant speed mechanism 121 is neutral. In some cases, it is possible to switch the cutting speed change mechanism 116, and it is possible to eliminate the problem that the outputs of the different speeds of the mechanisms 116 and 121 are simultaneously transmitted to the cutting unit 7. The speed output is prioritized over the output of the cutting speed change mechanism 116 and transmitted to the cutting unit 7 so that the cutting unit 7 can be driven smoothly, driving trouble of the cutting unit 7 can be reduced, and driving operability is improved. In addition, the constant speed fork 170, which is a constant rotation operation tool of the constant cutting speed mechanism 121, is operated in a position other than neutral, so that the cutting speed change mechanism 116 is neutral. When switching the output of the non-neutral 21, or return the cutting speed change mechanism 116 in a neutral, it can save the trouble of such as to ensure a neutral, improving the driving operability.

  Further, a speed change fork 169 which is a speed change operating tool for switching the cutting speed change mechanism 116 and a constant speed fork 170 for switching the constant speed mechanism 121 are provided on the same fork shaft 168 which is the same operation shaft. Are provided with a speed change cam 181 and a constant speed cam 183 that regulate the switching operation of each other, and the forks 169 and 170 are provided by sharing the same fork shaft 168. Can be easily assembled and adjusted, and the forks 169 and 170 can be easily connected to each other by the cams 181 and 183, so that the speed change operation structure can be simplified and compact, and the speed change operability can be improved. At the same time, a camshaft 168 provided with the speed change and constant rotation forks 169 and 170 is provided rotatably, and the fork shaft 1 Eight pins 182 and 184 are inserted into through holes of the forks 169 and 170 to form cams 181 and 183. The cams 181 and 183 can be provided by effectively using the fork shaft 168, and the pins The cams 181 and 183 have a simple structure and can be configured with high functionality by using the 182 and 184 and the through holes, thereby simplifying and downsizing the speed change operation structure and improving the speed change operability.

  Further, as shown in FIGS. 17, 20 to 22, a fastening seat 185 formed on the counter case 25 is fixed to the machine base 3 with a bolt 186 and a separation case 187 is detachably attached to the outside of the counter case 25. A part of the counter case 25 is formed by the separation case 187, and the outer side surface of the counter case 25 is formed to be openable and closable by attaching / detaching the separation case 187. The counter case 25 and the separation case 187 The shafts 107, 114, 115, 125, and 132 are pivotally supported, and the opening area of the outer surface of the case 25 when the separation case 187 is removed is larger than the opening 159 on the upper surface of the counter case 25. 107, 114, 115, 125, and 132 can be attached and detached and gears can be exchanged.

  As apparent from the above, in the work vehicle including the counter case 25 that distributes the power from the engine 21 to the traveling crawler 2 that is the traveling unit and the threshing unit 4 and the mowing unit 7 that are the working units, the upper surface of the counter case 25 The opening 159 that can be opened and closed is provided, and by opening the opening 159, the inside of the counter case 25 can be maintained through the opening 159, and the handleability can be improved. A separation case 187 forming a part of the counter case 25 is detachably provided as a cover on the outer side of the counter case 25, and the opening area of the outer side of the counter case 25 when the separation case 187 is removed is determined on the upper surface. The counter case 25 is formed larger than the opening 159, and the counter case 25 is removed by removing the separation case 187. Such gear or the shaft parts can be exchanged or damage check, it is possible to improve the maintainability.

  Also, the oil passage base 145 equipped with the hydraulic cylinders 142, 143, 144 and the hydraulic valves 148, 149, 150 closes the opening 159 on the upper surface of the counter case 25 so that it can be opened and closed. Since the lid of the case 25 is also used, it is possible to make it compact and improve the maintainability, and the support members 23 and 24 of the cutting unit 7 and the separation case 187 are configured separately, and the counter case 25 is fixed to this machine, and the separation case 187 is fixed to the counter case 25. The separation case 187 can be easily attached or removed, and the handling property such as maintenance can be improved.

  Further, as shown in FIG. 33, a threshing switch 190 for detecting the threshing operation of the work lever 189, a reaping switch 191 for detecting the reaping operation of the work lever 189, and a cutting speed change for switching the cutting speed change slider 119 between low speed and high speed. A switch 192, a high-speed operation switch 193 and a reverse switch 194 that detect switching between high-speed forward and reverse of the main transmission lever 81, a manual pouring switch 196 that detects an operator's stepping operation of the pouring pedal 195, and low-speed and high-speed A sub shift switch 197 for performing sub shift switching is connected to a work controller 198 constituted by a microcomputer.

  Further, a direct drive switch 199 for manually switching to an operation for driving the cutting unit 7 by a constant rotational output of the engine 21, an automatic switch 200 for turning on / off the manual input of the switch 199, and the speeds (vehicle speeds) of the left and right traveling crawlers 2 ) For detecting left and right vehicle speed sensors 201 and 202, for detecting the presence or absence of a conveying culm in the cutting unit 7, and for input of a tuning input shaft 112 for inputting a driving force for vehicle speed synchronization to the reaping unit 7. A cutting input sensor 204 for detecting the rotational speed via the low speed gear 117, a cutting low speed and cutting high speed solenoid 205/206 for switching the cutting shift cylinder 142 to a low speed or a high speed, and a feed chain so as to turn off the feed chain clutch 131. It is switched by a feed chain solenoid 191 that operates the clutch cylinder and a constant rotation cylinder 143. A flow solenoid 208 for engaging the idler 124 with the flow gear 122 and a high speed cut solenoid 209 for engaging the switching slider 124 with the high speed cut gear 123 by the constant speed cylinder 143 are connected to the work controller 198. As described above, the cutting unit 7 is operated at the pouring speed, the high speed cutting speed, or the vehicle speed synchronization speed.

  In addition, when the automatic switch 200 is turned on and the high-speed operation switch 193 is turned on, the high-speed operation solenoid 211 that turns on the constant-speed clutch 76 and the sub-transmission cylinder 197 are switched. The operation controller includes a low speed and high speed solenoids 212 and 213 for sub-transmission for operating the motor 85 to output the traveling motor 39 at low speed or high speed, and a threshing clutch solenoid 214 for turning on the threshing clutch 97 when the threshing switch 190 is turned on. Connect to 198.

  Furthermore, as shown in the flowchart of FIG. 34, when the threshing switch 190 is turned on by operating the operation lever 189, the feed chain solenoid 207 is turned off, the feed chain clutch 131 is turned on, the drive of the feed chain 5 is started, and The threshing clutch solenoid 214 is operated to turn on the threshing clutch 97, and the threshing unit 4 and the feed chain 5 are driven.

  When the cutting switch 191 is turned on by operating the work lever 189, the main transmission driving force is transmitted to the cutting unit 7 through the vehicle speed tuning pulley 93. At this time, when the pouring pedal 195 is stepped on and the pouring switch 196 is turned on, when the input rotational speed of the cutting portion 7 detected by the mowing input sensor 204 is equal to or less than the rotation setting by the pouring gear 122, the mowing is performed. The shift slider 119 is moved to the neutral position so that the cutting shift output of the cutting transmission mechanism 116 is neutral, the transmission of the vehicle speed tuning input shaft 122 is turned off, and the flow solenoid 208 is operated to cut the cutting portion 7 via the flow gear 122. Is driven at a constant speed at a lower speed than the high speed cut gear 123. On the other hand, when the pouring switch 196 is turned on, if the input rotational speed of the trimming section 7 is equal to or higher than the rotation setting by the pouring gear 122, the trimming shift output of the trimming transmission mechanism 116 is made neutral and the tuning input shaft 112 The transmission is turned off, and the high speed cut solenoid 209 is operated to drive the cutting unit 7 through the high speed cut gear 123 and drive at a constant speed at a maximum speed higher than that of the gear 122.

  When the reverse switch 194 is off and the axle 55 detected by the vehicle speed sensors 201 and 202 is stopped, the cutting speed change mechanism 116 is made neutral and the vehicle speed synchronization drive of the cutting unit 7 is stopped. On the other hand, when the axle 55 is driven, when the sub-shift output of the traveling motor 39 is at a low speed, the input rotation for the vehicle speed synchronization of the cutting unit 7 detected by the cutting input sensor 204 is equal to or higher than the rotation setting by the high speed cut gear 123. Then, the high-speed cut solenoid 209 is operated to make the cutting transmission mechanism 116 neutral, and the high-speed cutting operation for driving the cutting unit 7 at the maximum speed at a constant speed through the high-speed cutting gear 123 is performed.

  When the sub-shift output of the traveling motor 39 is low, the input rotation of the cutting unit 7 is greater than or equal to the setting, the automatic switch 200 is on, and the direct drive switch 199 is turned on, the high-speed operation solenoid 211 is operated, the constant speed clutch 76 is turned on, and the driving force of the engine 21 is directly transmitted from the constant speed clutch 76 to the auxiliary transmission mechanism 47 without passing through the traveling speed change member 40, so that the high speed operation is performed.

  Further, when the key switch for operating the engine 21 is turned on to apply power to the work controller 198, the low speed solenoid 212 is turned on to operate the auxiliary transmission valve 86, and the swash plate 84 of the travel motor 39 is switched to low speed. . The main transmission lever 81 is operated to change the swash plate 79 angle of the traveling pump 38 and travel, and the auxiliary transmission switch 197 is operated at a high speed, whereby the auxiliary transmission valve 86 is switched to a high speed and the auxiliary transmission switch 197 is operated. When the auxiliary speed change valve 86 is switched to a low speed by operating the low speed, the volume efficiency of the travel pump 38 is increased to 90 to 95% by operating the main speed change lever 81 so that the travel pump 38 reaches the maximum speed. When the high speed operation switch 193 is turned on by the main speed change lever 81 and the maximum speed operation of the main speed change lever 81 is detected, the low speed and high speed solenoids 212 and 213 are automatically turned off and the auxiliary speed change is made. The valve 86 is kept neutral, and the sub-transmission cylinder 85 is short-circuited to the oil tank side to freely move the piston of the cylinder 85 The swash plate 84 of the travel motor 39 is returned to the neutral side by the pump 38 hydraulic pressure so that the discharge hydraulic pressure of the travel pump 38 becomes the charge pump 78 hydraulic pressure, and the high-speed operation solenoid 211 is automatically turned on to determine the vehicle speed. The speed valve 147 is switched, the vehicle speed constant speed cylinder 146 is operated to turn on the constant speed clutch 76, and the driving force of the engine 21 is directly transmitted from the constant speed clutch 76 to the auxiliary transmission mechanism 47 without passing through the traveling speed change member 40. The left and right traveling crawlers 2 are driven. After the constant speed clutch 76 is turned on, about 0.2 seconds have elapsed, the auxiliary transmission valve 86 is neutralized, and the swash plate 84 of the traveling motor 39 is delayed. Let it be free.

  As is apparent from the above, the traveling crawler 2 that is the traveling portion is driven by the shift output of the hydraulic pump 38 of the traveling transmission member 40 that is the hydraulic transmission mechanism at a speed that is less than or equal to the maximum speed, and the vehicle travels near the maximum speed. In a work vehicle provided with a constant speed clutch 76 that is a vehicle speed constant speed mechanism that directly connects the input side and the output side of the speed change member 40, after the traveling crawler 2 is shifted from a hydraulic speed shift to a constant speed drive in the vicinity of the maximum speed. The output adjustment of the hydraulic motor 39 of the traveling speed change member 40 is made free. In addition, the structure capable of running smoothly reduces horsepower loss near the maximum speed, and reduces shocks felt by the operator, such as shocks when the running crawler 2 is switched from hydraulic speed change to constant speed drive. , Improve handling.

  Further, when the direct drive switch 199 is off, the cutting shift output of the cutting transmission mechanism 116 is switched to low speed or high speed by operating the cutting shift switch 197, and the cutting unit is driven by vehicle speed tuning input through one of the gears 117 and 118. 7 is driven at a low speed or at a high speed, and a standing culm is cut at a low speed, or a lying culm is cut at a high speed.

  Further, as shown in the vehicle speed control flowchart of FIG. 35 and the output diagram showing the relationship between the vehicle speed and the rotational speed of the cutting unit 7 in FIG. 36, the vehicle speed and the rotational speed of the cutting unit 7 are increased by the speed increasing operation of the main transmission lever 81. When the harvesting operation is carried out at a high speed by synchronizing the swaying, the traveling crawler 2 is continuously shifted by the output of the traveling transmission member 40 until the cutting part 7 performs the high speed cutting operation, and the cutting part 7 is synchronized with the vehicle speed. When the vehicle speed increases to the high speed cutting position of the cutting unit 7, the high speed cutting solenoid 209 is automatically excited to transmit the engine 21 output to the cutting unit 7 via the cutting constant speed mechanism 121. A high-speed cutting operation for driving the unit 7 at a constant speed is performed. Further, when the vehicle speed increases to near the maximum speed or when the high speed operation switch 197 is turned on by the maximum speed operation of the main speed change lever 81, the high speed operation solenoid 211 is automatically excited to perform the vehicle speed constant speed clutch 76. The vehicle speed locking operation is performed to directly connect the input side and the output side of the traveling speed change member 40, and the traveling crawler 2 is driven at a vehicle speed locking position near the maximum speed.

  As is clear from the above, the traveling crawler 2 as the traveling unit and the cutting unit 7 as the working unit are driven by the shift output of the hydraulic pump 38 of the traveling transmission member 40 as the hydraulic transmission mechanism at a speed below the maximum speed. In addition, a constant speed clutch 76 that is a vehicle speed constant speed mechanism that directly connects the input side and the output side of the traveling speed change member 40 in the vicinity of the highest speed, and a cutting constant speed mechanism that is a work constant speed mechanism that drives the cutting part 7 at a constant speed. In the work vehicle provided with 121, the cutting unit 7 is shifted from the vehicle speed synchronization to the constant speed drive before the highest work speed. And with a structure that can work smoothly at a work speed synchronized with the vehicle speed, while reducing the horsepower loss near the maximum speed, work such as shock when switching the cutting part 7 from vehicle speed synchronization to constant speed drive Alleviate the shock felt by the person and improve handling. Further, when the cutting unit 7 is shifted from the vehicle speed tuning to the constant speed driving, the vehicle crawler 2 is shifted from the hydraulic speed change driving to the constant speed driving after increasing the vehicle speed. After shifting to driving, the vehicle speed is increased to the vicinity of the maximum speed, and then the traveling crawler 2 is driven at a constant speed to reduce the horsepower loss near the maximum speed, and the input side and the output side of the traveling transmission member 40 are directly connected. This reduces the shock felt by the operator, such as the shock at the time of operation, and improves handling.

  Further, when the traveling crawler 2 and the cutting unit 7 are driven at a constant speed in the vehicle speed lock operation state, if the vehicle speed is lowered by the deceleration side operation of the main transmission lever 81, the vehicle speed is lowered to the high speed cut position of the cutting unit 7. Up to this point, while the traveling crawler 2 is driven by the continuously variable transmission output of the traveling transmission member 40 by disengaging the vehicle speed constant speed clutch 76, the cutting unit 7 is driven at a constant speed, and the vehicle speed is the high speed cutting position of the cutting unit 7. Is lowered, the high-speed cut solenoid 209 is turned off, the cutting high-speed solenoid 206 is turned on, and the cutting unit 7 is driven in synchronism with the vehicle speed.

  As is clear from the above, when the traveling crawler 2 is switched from the constant speed drive to the hydraulic speed change drive due to the deceleration of the vehicle speed from around the maximum speed, after the vehicle speed further decelerates, the cutting unit 7 is synchronized from the constant speed drive to the vehicle speed. Switch to. The shock felt by the operator, such as a shock when switching the mowing unit 7 from constant speed driving to vehicle speed synchronization or a shock when releasing the direct connection between the input side and the output side of the traveling speed change member 40, is eased. To improve.

  As is apparent from the above embodiments, the present invention drives the traveling unit 2 and the working unit 7 by the shift output of the hydraulic pump 38 of the hydraulic transmission mechanism 40 at a speed lower than the highest speed as in claim 1. In a work vehicle provided with a vehicle speed constant speed mechanism 76 that directly connects the input side and the output side of the hydraulic transmission mechanism 40 in the vicinity of the maximum speed and a work constant speed mechanism 121 that drives the work unit 7 at a constant speed, before the work speed is the fastest. The work unit 7 is shifted from the vehicle speed synchronization to the constant speed drive, and can be smoothly operated at a work speed synchronized with the vehicle speed, and the horsepower loss near the maximum speed can be reduced. The shock felt by the operator, such as a shock when the part 7 is switched from the vehicle speed synchronization to the constant speed drive, can be alleviated, and the handleability can be improved.

  According to the second aspect of the present invention, when the working unit 7 is shifted from the vehicle speed synchronization to the constant speed driving, the traveling unit 2 is shifted from the hydraulic transmission to the constant speed driving after the vehicle speed is increased. After the vehicle is shifted from the vehicle speed tuning to the constant speed drive, the vehicle speed is increased to the vicinity of the maximum speed, and then the traveling unit 2 is driven at a constant speed. The shock felt by the operator, such as a shock when the input side and the output side of the mechanism 40 are directly connected, can be mitigated, and the handleability can be improved.

  According to the third aspect of the present invention, when the traveling unit 2 is switched from the constant speed drive to the hydraulic speed change drive by the deceleration of the vehicle speed from the vicinity of the maximum speed, after the vehicle speed is further decelerated, the working unit 7 is moved from the constant speed drive to the vehicle speed. Reduces shocks felt by the operator, such as shocks when the working unit 7 is switched from constant speed drive to vehicle speed synchronization or shocks when the direct connection between the input side and the output side of the hydraulic transmission mechanism 40 is released. The handling property can be improved.

  Further, according to the fourth aspect of the present invention, the traveling unit 2 is driven by the shift output of the hydraulic pump 38 of the hydraulic transmission mechanism 40 at a speed below the maximum speed, and the input side and the output of the hydraulic transmission mechanism 40 are output near the maximum speed. In a work vehicle provided with a vehicle speed constant speed mechanism 76 that is directly connected to the vehicle side, after the traveling unit 2 is shifted from a hydraulic speed shift to a constant speed drive in the vicinity of the maximum speed, the output adjustment of the hydraulic motor 39 of the hydraulic speed change mechanism 40 is adjusted. It is free and has a structure that can run smoothly, reduce horsepower loss near the maximum speed, and work such as shocks when switching the traveling unit 2 from hydraulic shift to constant speed drive The shock felt by the person can be alleviated, and the handleability can be improved.

The perspective view of a combine. The same side view. FIG. Side surface explanatory drawing of a front body. The front explanatory drawing. Side surface explanatory drawing of a drive part. The front explanatory drawing. FIG. Drive system diagram of the transmission case. FIG. FIG. An enlarged view of the previous figure. The enlarged view. Engine output system diagram. Hydraulic circuit diagram. The drive system figure of a counter case. FIG. The enlarged view. FIG. The external appearance front view. FIG. The same side view. The top view of a threshing clutch part. The rear view. FIG. Sectional drawing of a threshing cylinder part. The bottom view of an oil passage base. FIG. Sectional drawing of a trimming shift cylinder part. Sectional drawing of a cutting constant speed cylinder part. The cross-sectional rear view of a fork shaft part. FIG. FIG. The harvesting operation control flowchart of the previous figure. The vehicle speed control flowchart. Traveling pump output diagram.

Explanation of symbols

2 Traveling crawler (traveling part)
7 Mowing section (working section)
38 Hydraulic traveling pump 39 Hydraulic traveling motor 40 Traveling transmission member (hydraulic transmission mechanism)
76 Vehicle speed constant speed clutch (vehicle speed constant speed mechanism)
121 Mowing constant speed mechanism (work constant speed mechanism)

Claims (4)

  A vehicle speed constant speed mechanism that drives the traveling part and the working part by the speed change output of the hydraulic pump of the hydraulic speed change mechanism at a speed lower than the maximum speed, and directly connects the input side and the output side of the hydraulic speed change mechanism near the highest speed. A work vehicle provided with a work constant speed mechanism for driving the work part at a constant speed, wherein the work part is shifted from vehicle speed synchronization to constant speed drive before the highest work speed.   2. The work vehicle according to claim 1, wherein when the working unit is shifted from vehicle speed synchronization to constant speed driving, the traveling unit is shifted from hydraulic transmission to constant speed driving after increasing the vehicle speed.   The operation unit is switched from constant speed drive to vehicle speed tuning after the vehicle speed is further decelerated when the traveling unit is switched from constant speed drive to hydraulic speed change drive by deceleration of the vehicle speed from around the maximum speed. The work vehicle according to 1.   A work vehicle that is provided with a vehicle speed constant speed mechanism that drives the traveling portion by the speed change output of the hydraulic pump of the hydraulic speed change mechanism at a speed lower than the maximum speed and that directly connects the input side and output side of the hydraulic speed change mechanism near the maximum speed. The working vehicle is characterized in that the output of the hydraulic motor of the hydraulic transmission mechanism is made free after the traveling portion is shifted from the hydraulic transmission to the constant speed drive in the vicinity of the maximum vehicle speed.

Images