JP2009232782A - Travel transmission mechanism of reaping harvester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To compose a travelling transmission mechanism of a reaping harvester to be capable of setting the travelling speed at a sufficiently high speed side and the low speed reaping work speed at a sufficiently low speed side while suppressing number of speeds. <P>SOLUTION: A first transmission device 19 and a second transmission device 28, freely changeable to plural stages, are serially equipped in a transmission system transmitting to a travelling device. The transmission ratio when the first transmission device 19 is in the low speed position and the second transmission device 28 is in the high speed position, and the transmission ratio when the first transmission device 19 is in the high speed position and the second transmission device 28 is in the low speed position, are set to be the same transmission ratios. When the first transmission device 19 is in the low speed position and the second transmission device 28 is in the high speed position, the reaping work speed is obtained, and, when the first transmission device 19 is in the low speed position and the second transmission device 28 is in the low speed position, the low speed reaping work speed is obtained. When the first transmission device 19 is in the high speed position and the second transmission device 28 is in the high speed position, the travelling speed is obtained, and, when the first transmission device 19 is in the high speed position and the second transmission device 28 is in the low speed position, the reaping work speed is obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a traveling speed change structure for a harvesting and harvesting machine such as a combine.

  In the harvesting harvester, for example, as disclosed in Patent Document 1, the power of the engine (6 in FIG. 2 of Patent Document 1) branches the first rotating shaft (10 in FIG. 2 and FIG. 3 in Patent Document 1). As a point, it is branched into two systems: a transmission system to the cutting part (3 in FIG. 2 of Patent Document 1) and a transmission system to the traveling device (1R, 1L in FIG. 2 of Patent Document 1). The transmission system is provided with a transmission (11 in FIGS. 2 and 3 of Patent Document 1).

  In Patent Document 1, a transmission for traveling is configured to be variable in a plurality of stages at a low speed position, a medium speed position, and a high speed position. The medium speed position is a speed at which a cutting work speed used in a normal cutting work state is obtained, and the high speed position is a speed at which a moving speed used on the road or the like is obtained. When the crops are lying more than normal, the speed of the aircraft is lower than that of the fallen crops by the cutting part by obtaining a low speed cutting speed that is lower than the cutting speed due to the low speed position. Can be avoided (see [0028] of Patent Document 1).

JP 2001-193835 A

In recent years, there has been an increasing demand for setting the moving speed sufficiently high, and for setting the low-speed cutting work speed sufficiently low. In this case, in Patent Document 1, if a traveling transmission different from the traveling transmission is arranged in series, the movement speed is sufficiently high on the power of the two traveling transmissions. It can be set, and the low-speed cutting work speed can be set sufficiently low.
However, if two travel transmissions are arranged in series, the number of shift stages obtained by multiplying the two travel transmissions by the number of shift stages can be obtained, and the two transmissions can be shifted. The number of steps becomes unnecessarily large.

  In the traveling speed change structure of the harvesting and harvesting machine, the present invention branches the engine power into two systems, that is, a transmission system to the cutting unit and a transmission system to the traveling device, and the transmission system to the traveling device can be shifted in multiple stages. When two traveling gearboxes are arranged in series, the moving speed can be set to a sufficiently high speed side while suppressing the number of shift stages as the two traveling gearboxes, and the low speed cutting operation speed Is intended to be configured to be sufficiently low speed side.

[I]
(Constitution)
The first feature of the present invention resides in the following structure in the traveling speed change structure of a harvesting harvester.
The power of the engine is branched into two systems, a transmission system to the cutting part and a transmission system to the traveling device, and the transmission system to the traveling device is divided into a first transmission device for traveling that can be shifted in multiple stages, and a plurality of stages. A second transmission for variable speed travel is provided in series.
The transmission ratio when the first transmission is operated to the low speed position and the second transmission is operated to the high speed position, and the first transmission is operated to the high speed position and the second transmission is operated to the low speed position. Set the transmission ratio in the same state to the same transmission ratio.
When the first transmission is operated to the low speed position and the second transmission is operated to the high speed position, the cutting work speed is obtained, the first transmission is operated to the low speed position, and the second transmission is set to the low speed position. When operated, a low-speed cutting operation speed is obtained.
When the first transmission is operated to the high speed position and the second transmission is operated to the high speed position, the moving speed is obtained, the first transmission is operated to the high speed position, and the second transmission is operated to the low speed position. Then, the cutting operation speed is obtained.

(Function)
According to the first feature of the present invention, the power of the engine is branched into two systems, a transmission system to the cutting part and a transmission system to the traveling device, and the transmission system to the traveling device is used for traveling that is variable in multiple stages. A first transmission and a second transmission for traveling that can be shifted in a plurality of stages are provided in series. As a result, the moving speed (operating the first and second transmission devices to the high speed position) can be set sufficiently high, and the low speed cutting operation speed (operating the first and second transmission devices to the low speed position) can be set. It can be set sufficiently low.

In this case, according to the first feature of the present invention, the transmission ratio when the first transmission is operated to the low speed position and the second transmission is operated to the high speed position, and the first transmission is operated to the high speed position. The transmission ratio in the state where the second transmission is operated to the low speed position is set to the same transmission ratio.
As a result, the traveling speed of the airframe when the first transmission is operated to the low speed position and the second transmission is operated to the high speed position, the first transmission is operated to the high speed position, and the second transmission is Since the traveling speed of the airframe in the state operated to the low speed position becomes the same speed and the same cutting work speed, the number of shift stages as the first and second transmissions is reduced by the same cutting work speed. be able to.

According to the first feature of the present invention, in the state where the first transmission is operated to the low speed position, operating the second transmission to the high speed position provides a cutting work speed, and operates the second transmission to the low speed position. Then, a low-speed cutting work speed is obtained.
Thereby, in a field where crops lying down are scattered among normal crops, the second transmission can be operated to the high speed position by operating the first transmission to the low speed position (cutting work speed). ), By operating the second transmission to a low speed position (low speed cutting work speed), it is possible to appropriately cope with the state of the crop.

According to the first aspect of the present invention, in the state where the first transmission is operated to the high speed position, operating the second transmission to the low speed position provides a cutting work speed, and operates the second transmission to the high speed position. Then movement speed is obtained.
Thus, for example, in a combine equipped with a Glen tank (an example of a harvesting harvester), by operating the first transmission to the high speed position, the second transmission is operated to the low speed position to perform the cutting operation ( When the grain tank is full, the second transmission is moved to the high speed position (moving speed), moved to the position of the truck located outside the field, and the grain in the grain tank is moved to the truck. Can be handled appropriately.

(The invention's effect)
According to the first aspect of the present invention, in the traveling speed change structure of the harvesting and harvesting machine, the moving speed (operating the first and second transmission devices to the high speed position) can be set sufficiently high, and the low speed cutting speed is achieved. (Operating the first and second transmissions to the low speed position) can be set to a sufficiently low speed side, and the number of shift stages as the first and second transmission units is reduced by the same cutting work speed. As a result, the driver is less confused by the large number of gears and the operability can be improved.

  According to the first feature of the present invention, in a state where the first transmission is operated to the low speed position, the second transmission is operated to the high speed position and the low speed position, or the first transmission is operated to the high speed position, By operating the second transmission to a low speed position and a high speed position, it is possible to appropriately cope with various states, and it is possible to improve operability and workability.

[II]
(Constitution)
The second feature of the present invention resides in the following structure in the traveling shift structure of the harvesting and harvesting machine of the first feature of the present invention.
An artificial operation tool that is artificially operated and an operation unit that operates the second transmission device based on the operation of the artificial operation tool.

(Function)
According to the second feature of the present invention, the “action” described in the preceding item [I] is provided in the same manner as the first feature of the present invention, and in addition to this, the following “action” is provided.
According to the second feature of the present invention, the driver does not directly operate the second transmission device with the operating force when operating the human operating tool, but the second speed change by the operating means based on the operation of the human operating tool. Operate the device. As a result, the driver can operate the second transmission device with a light operation to the extent that the manual operation tool is operated.

(The invention's effect)
According to the second feature of the present invention, the “effect of the invention” described in the preceding item [I] is provided in the same manner as the first feature of the present invention. In addition, the following “effect of the invention” is provided. ing.
According to the second feature of the present invention, the second transmission can be operated with a light operation to the extent that the artificial operation tool is operated, and the operability can be improved.

[1]
As shown in FIG. 1, a cutting unit 2 is supported on a front portion of a machine body supported by a crawler type right and left traveling device 1 so as to be movable up and down, and a driving unit 3 is provided on the rear side of the cutting unit 2. Thus, a threshing device 4 is provided on the rear left side of the machine body, and a grain tank 5 is provided on the rear right side of the machine body to constitute a combine that is an example of a harvesting and harvesting machine.

  FIG. 2 shows an outline of the transmission system of the mission case 6. The power of the engine 7 is transmitted to the hydrostatic continuously variable transmission 9 via a belt transmission mechanism 8 having a tension clutch function, and the power of the output shaft 9a of the hydrostatic continuously variable transmission 9 is Transmission gear 33 (fixed to the output shaft 9a of the hydrostatic continuously variable transmission 9), transmission gear 34 (fixed to the transmission shaft 10), transmission shaft 10, one-way clutch 11, output pulley 12, and belt having a tension clutch function It is transmitted to the cutting unit 2 through the transmission mechanism 13. Thereby, the power of the engine 7 is branched into a transmission system to the cutting unit 2 and a transmission system to the right and left traveling devices 1 with the transmission shaft 10 as a branch point.

  As shown in FIGS. 2 and 7, the hydrostatic continuously variable transmission 9 has a neutral position and is configured to be continuously variable to the forward side and the reverse side, and is provided in the driving unit 3. The hydrostatic continuously variable transmission 9 is operated by the shift lever 93. The one-way clutch 11 interrupts the reverse power of the hydrostatic continuously variable transmission 9 and transmits the forward power of the hydrostatic continuously variable transmission 9 to the output pulley 12.

As shown in FIG. 1 and FIG. 2, in the sprocket 98 that drives the right and left traveling devices 1, as shown in FIG. 8, the tip and the base of the drive teeth 98a of the sprocket 98 have substantially the same width (sprocket 98 (circumferential direction of 98), and the vertical surface portion 98b of the drive tooth 98a of the sprocket 98 is configured to be substantially linear (substantially parallel to the radial direction of the sprocket 98) in a side view.
As a result, in the right and left traveling apparatuses 1, the core metal 99 a of the crawler belt 99 comes into contact with the substantially entire surface of the vertical surface portion 98 b of the drive tooth 98 a of the sprocket 98, and the core metal 99 a of the crawler belt 99 is sprocket 98. It is possible to prevent partial wear due to partial contact with the drive teeth 98a.

[2]
Next, the first transmission 19 (corresponding to a first transmission for traveling) and the second transmission 28 (corresponding to a second transmission for traveling) will be described.
As shown in FIGS. 2 and 3, the shift gear 14 is externally fitted to the transmission shaft 10 so as to be slid and integrally rotatable by a spline structure, and the low-speed gear 15 is externally fitted to the transmission shaft 10 so as to be relatively rotatable. A low speed gear 17 and a high speed gear 18 are fixed to the transmission shaft 16, and the low speed gears 15 and 17 are engaged with each other.

  2 and 3, when the shift gear 14 is engaged with the low speed gear 14 (low speed position), the power of the transmission shaft 10 is transmitted to the transmission shaft 16 in a low speed state, and the shift gear 14 is transmitted to the high speed gear 18. When being engaged with each other (high speed position), the power of the transmission shaft 10 is transmitted to the transmission shaft 16 in a high speed state. As described above, the shift gear 14, the low-speed gears 15 and 17, the high-speed gear 18, and the like constitute the first transmission 19 that can be shifted in two steps.

  As shown in FIGS. 2 and 3, the shift gear 20 is externally fitted to the transmission shaft 16 so as to be slidable and relatively rotatable, and the shift gear 20 is urged to the occlusal side of the low-speed gear 17 by the spring 21, so that hydraulic oil is supplied. As a result, the shift gear 20 is operated away from the low speed gear 17. A high speed gear 22 is fitted on the transmission shaft 16 so as to be relatively rotatable, and a hydraulic clutch 23 is provided between the transmission shaft 16 and the high speed gear 22. The hydraulic clutch 23 is configured as a friction multi-plate type and is urged to a cut-off state, and is operated to a transmission state by supplying hydraulic oil.

  As shown in FIGS. 2 and 3, a low speed gear 25 and a high speed gear 26 are fitted on the transmission shaft 24 so as to be relatively rotatable, and the low speed gear 25 and the high speed gear 26 are integrally rotated by a cylindrical transmission member 27. It is connected to. The high speed gears 22 and 26 are engaged, the shift gear 20 and the low speed gear 25 are engaged, and even if the shift gear 20 is slid, the shift gear 20 and the low speed gear 25 are always engaged.

  2 and 3, when the hydraulic clutch 23 is operated in the disconnected state and the shift gear 20 is engaged with the low speed gear 17 (low speed position), the power of the transmission shaft 16 is reduced in the low speed state. When the shift gear 20 is operated away from the low speed gear 17 and the hydraulic clutch 23 is operated in the transmission state (high speed position), the power of the transmission shaft 16 is transmitted to the transmission member 27 in the high speed state. As described above, the shift gear 20, the low-speed gear 25, the high-speed gears 22, 26, the hydraulic clutch 23, and the like constitute the second transmission 28 that can be shifted in two steps.

2 and 3, the first transmission 19 is operated to the low speed position (the shift gear 14 is engaged with the low speed gear 15), and the second transmission 28 is moved to the high speed position (the shift gear 20 is moved from the low speed gear 17). It is assumed that the transmission ratio G1 from the transmission shaft 10 to the transmission member 27 is in a state where the hydraulic clutch 23 is separated and is operated to the transmission state.
The first transmission 19 is operated to the high speed position (the shift gear 14 is engaged with the high speed gear 18), and the second transmission 28 is operated to the low speed position (the shift gear 20 is engaged with the low speed gear 17 and the hydraulic clutch 23 is disconnected). It is assumed that the transmission ratio G <b> 2 from the transmission shaft 10 to the transmission member 27 is in the state of being operated.
In this case, the gear ratios of the shift gear 14, the low-speed gears 15, 17, the shift gear 20, the low-speed gear 25, and the high-speed gears 22, 26 are set so that the transmission ratio G1 and the transmission ratio G2 are the same (or substantially the same). Is set.

  As shown in FIGS. 2 and 3, when the first transmission 19 is operated to the low speed position and the second transmission 28 is operated to the high speed position, the cutting operation speed used in the normal cutting operation state can be obtained. Yes, the traveling speed of the airframe is adjusted by operating the hydrostatic continuously variable transmission 9 within the range of the cutting work speed. When the first transmission device 19 is operated to the low speed position and the second transmission device 28 is operated to the low speed position, a low speed cutting work speed lower than the cutting work speed can be obtained. By operating the continuously variable transmission 9, the traveling speed of the aircraft is adjusted. The low-speed cutting operation speed is used when the crops on the field are lying more than in the normal cutting operation state.

  As shown in FIGS. 2 and 3, when the first transmission 19 is operated to the high speed position and the second transmission 28 is operated to the high speed position, the moving speed used on the road or the like can be obtained. By operating the hydrostatic continuously variable transmission 9 within the range, the traveling speed of the aircraft is adjusted. When the first transmission device 19 is operated to the high speed position and the second transmission device 28 is operated to the low speed position, the same cutting work speed as described above can be obtained, and the hydrostatic continuously variable transmission 9 is within the range of the cutting work speed. By adjusting, the aircraft's running speed is adjusted.

[3]
Next, a transmission system (straight traveling system) to the right and left traveling devices 1 of the mission case 6 will be described.
As shown in FIGS. 2 and 3, a right traveling transmission gear 29 is fitted between the transmission member 27 and the low-speed gear 25 so as to be relatively rotatable and is externally fitted to the low-speed gear 25. In the middle, the left traveling transmission gear 30 is externally fitted to the high speed gear 26 so as to be relatively rotatable. A spline portion is formed on the outer surface of the transmission member 27, and a right transmission member 31 having a spline portion on the inner peripheral surface is slidably fitted over the transmission member 27 and the right traveling transmission gear 29. The left transmission member 32 having a spline portion on the inner peripheral surface is slidably fitted over the transmission member 27 and the left traveling transmission gear 30.

  As shown in FIGS. 2 and 3, transmission gears 36 and 37 are fixed to the transmission shaft 35, the transmission gear 36 is engaged with the left traveling transmission gear 30, and the axle 32 that drives the left traveling apparatus 1. The transmission gear 39 fixed to is engaged with the transmission gear 37. A transmission gear 40 externally fitted to the transmission shaft 35 is engaged with the right traveling transmission gear 29, and a transmission gear 41 externally fitted to the transmission shaft 35 is connected to the transmission gear 40. The transmission gears 40 and 41 are integrally fitted on the transmission shaft 35 so as to be relatively rotatable, and the transmission gear 42 fixed to the axle 32 that drives the right traveling device 1 is engaged with the transmission gear 41.

The state shown in FIGS. 2 and 3 is a state where the right transmission member 31 is operated to a transmission position where the right transmission member 31 is engaged with the transmission member 27 and the right traveling transmission gear 29, and the left transmission member 32 is connected to the transmission member 27. It is in a state where it has been operated to a transmission position that meshes with the left traveling transmission gear 30.
In this state, the power of the transmission member 27 is transmitted to the right traveling device 1 through the right transmission member 31, the right traveling transmission gear 29, and the transmission gears 40, 41, 42. Is transmitted to the left traveling device 1 through the left transmission member 32, the left traveling transmission gear 30, the transmission gear 36, the transmission shaft 35, and the transmission gears 37 and 39, and the aircraft advances straight.

[4]
Next, the transmission system (turning system) to the right and left traveling devices 1 of the mission case 6 will be described.
As shown in FIGS. 2 and 4, the turning transmission shaft 43 is rotatably supported, a spline portion 43 a is fixed to the center of the turning transmission shaft 43, and the shift member 44 is slidable and rotatable integrally with the spline structure. The spline part 43a of the turning transmission shaft 43 is externally fitted.

  As shown in FIGS. 2 and 4, the slow turning gear 45 is externally fitted to the side of the spline portion 43 a of the turning transmission shaft 43 so as to be relatively rotatable, and the slow turning gear 45 is engaged with the high speed gear 26. . A reversing gear 46 is externally fitted to the side of the spline portion 43a of the turning transmission shaft 43 (on the side opposite to the slow turning gear 45) so as to be relatively rotatable, and the reversing gear 47 is fixed to the transmission shaft 16 so that the reverse rotation is achieved. The gears 46 and 47 are engaged. As described above, the turning transmission shaft 43, the shift member 44, the slow turning gear 45, the reverse rotation gear 46, and the like constitute the turning mechanism 48, and the turning transmission shaft 43 is interposed between the slow turning gear 45 and the reverse rotation gear 46. The spline part 43a is located.

  2 and 4, the transmission gear 49 is fixed to the turning transmission shaft 43, the transmission gear 50 is externally fitted to the transmission shaft 24 so as to be relatively rotatable, and the transmission gears 49 and 50 are engaged. A hydraulic clutch 51 is provided between the transmission shaft 24 and the transmission gear 50. The hydraulic clutch 51 is configured as a frictional multi-plate type and is biased to a cut-off state, and is operated to a transmission state by supplying hydraulic oil.

  As shown in FIGS. 2 and 4, a brake 52 is provided between the outer peripheral portion of the casing 51 a (fixed to the transmission shaft 24) of the hydraulic clutch 51 and the inner surface portion of the transmission case 6. The brake 52 is disposed concentrically around the transmission shaft 24. The brake 53 is configured as a friction multi-plate type and is biased to a released state, and is operated to a braking state by supplying hydraulic oil. Since the brake 52 applies braking to the casing 51 a (fixed to the transmission shaft 24) of the hydraulic clutch 51, if the brake 52 is operated to a braking state, the transmission shaft 24 is braked, and the hydraulic clutch 51 is in a disconnected state. In this case, the turning transmission shaft 43 is not braked.

  As shown in FIGS. 2, 3, and 4, a transmission member 53 having a spline portion on the outer peripheral surface is fixed to the transmission shaft 24, and a turning transmission member 54 having a spline portion on the inner peripheral surface slides on the transmission member 53. The right turning transmission gear 55 is fitted on one side of the transmission member 53 (transmission shaft 24) so as to be relatively rotatable, and the left turning transmission gear 56 is fitted on the transmission member 53 (transmission shaft). 24) and is fitted on the other side so as to be relatively rotatable.

  2, 3 and 4, the transmission gear 57 fixed to the transmission shaft 35 is engaged with the left turning transmission gear 56, and the transmission gear 58 fixed to the transmission gears 40 and 41 is turned to the right. It meshes with the transmission gear 55. A hydraulic clutch 59 is provided between the transmission shaft 35 and the transmission gear 40. The hydraulic clutch 59 is configured as a frictional multi-plate type and is energized in a shut-off state, and is supplied with hydraulic oil to be in a transmission state. Operated.

  As a result, as shown in FIGS. 2 and 4, the shift member 44 is operated to a slow turning position that engages the turning transmission shaft 43 and the spline portions 43 a and 45 a of the slow turning gear 45 to transmit the hydraulic clutch 51. When the brake 52 is operated to the release state, the power transmitted from the second transmission 28 to the low speed gear 25 and the high speed gear 26 is transmitted to the low speed gear 26, the slow turning gear 45, the turning transmission shaft 43, and the transmission gear. 49, 50, the hydraulic clutch 51, and the transmission shaft 24 are transmitted to the transmission member 53 as low-speed power in the same direction as the power of the low-speed gear 25 and high-speed gear 26, as described in [10] described later. The airframe is transmitted to the right (left) traveling device 1 and the aircraft slowly turns to the right (left).

  As shown in FIGS. 2 and 4, the shift member 44 is operated to the reverse rotation position where the shift member 44 is engaged with the rotation transmission shaft 43 and the spline portions 43a, 46a of the reverse rotation gear 46, and the hydraulic clutch 51 is operated to the transmission state. When the brake 52 is operated to the release state, the power transmitted from the first transmission 19 to the transmission shaft 16 is applied to the reverse rotation gears 46 and 47, the turning transmission shaft 43, the transmission gears 49 and 50, the hydraulic clutch 51 and the transmission shaft 24. Through the transmission member 53 as the power in the direction opposite to the power of the low speed gear 25 and the high speed gear 26, and transmitted to the right (left) traveling device 1 as described in [12] described later. The aircraft turns to the right (left).

  As shown in FIGS. 2 and 4, when the shift member 44 is operated to the slow turning position or the reverse rotation position, the hydraulic clutch 51 is operated to the disengaged state, and the brake 52 is operated to the braking state, the braking force of the brake 52 is increased. It is transmitted to the transmission member 53 via the transmission shaft 24 and is transmitted to the right (left) traveling device 1 as described in [11], which will be described later, and the aircraft turns to the right (left).

[5]
Next, the hydraulic circuit structure of the second transmission 28, the right and left transmission members 31, 32, the shift member 44, the turning transmission member 54, the hydraulic clutches 51, 59, and the brake 52 will be described.
As shown in FIG. 5, an oil passage 61 from a hydraulic pump 60 is supplied to the hydrostatic continuously variable transmission 9, a relief valve 62 is provided in the oil passage 61, and a relief valve 63 is provided in the oil passage 61. It is connected.

  As shown in FIGS. 4 and 5, a double-action type operating cylinder 64 is provided, and three shift forks 64 a provided in the operating cylinder 64 include right and left transmission members 31 and 32, and a turning transmission member 54. The oil passages 65, 66, 67 from the hydraulic pump 60 are connected to the operation cylinder 64. Right and left direction switching valves 68 and 69 are provided in the oil passages 66 and 67, and the right and left direction switching valves 68 and 69 are electromagnetically operated with a hydraulic oil supply position and an oil discharge position. The spring is biased to the oil drain position.

  As shown in FIG. 5, a proportional electromagnetic pressure control valve 71 and a switching valve 72 are provided in series in an oil passage 70 from the operation cylinder 64, and a hydraulic clutch 51 and a brake 52 are connected to the switching valve 72. Yes. The switching valve 72 supplies hydraulic oil to the hydraulic clutch 51 to operate the hydraulic clutch 51 in a transmission state, discharges the hydraulic oil from the brake 52, and operates the brake 52 in a released state, the hydraulic clutch 51. The hydraulic fluid is discharged from the hydraulic clutch 51 so that the hydraulic clutch 51 is operated to be disconnected, the hydraulic fluid is supplied to the brake 52, and the brake 52 is operated to the braking state. It is comprised and is urged | biased by the 1st turning position with the spring.

  As shown in FIG. 5, the pilot oil passage 73 extends from the oil passage 65 and is connected to the switching valve 72, and the pilot oil passage 73 is provided with a switching valve 74. The switching valve 74 has a supply position for supplying the pilot hydraulic oil to the switching valve 72 and a drain oil position for discharging the pilot hydraulic oil, and is configured to be electromagnetically operated, and is urged to the drain position by a spring. . When the switching valve 74 is operated to the oil discharge position, the switching valve 72 is operated to the first turning position, and when the switching valve 74 is operated to the supply position, the switching valve 72 is operated to the second turning position.

  As shown in FIGS. 4 and 5, a switching valve 76 and an operation cylinder 77 are provided in series in an oil passage 75 branched from the oil passage 65, and the shift member 44 is operated to a slow turning position and a reverse rotation position by the operation cylinder 77. The operation cylinder 77 is biased to a gentle turning position by a spring. The switching valve 76 supplies hydraulic oil to the operation cylinder 77 to operate the operation cylinder 77 in the reverse rotation position, and discharges the hydraulic oil from the operation cylinder 77 to operate the operation cylinder 77 in the slow rotation position. It is configured to be electromagnetically operated, and is urged to a gentle turning position by a spring.

  As shown in FIG. 5, a switching valve 79 (corresponding to the operating means) and the shift gear 20 are provided in series in an oil passage 78 branched from the oil passage 65, and an oil passage 80 branched from between the switching valve 79 and the shift gear 20 is provided. The accumulator 81 and the hydraulic clutch 23 are provided in series, and an oil passage 82 that can unload the oil passage 80 and a valve mechanism 83 that can open and close the oil passage 82 are provided. The switching valve 79 has a high speed position for supplying hydraulic oil to the shift gear 20 and a low speed position for discharging hydraulic oil from the shift gear 20 and is configured to be electromagnetically operated, and is biased to a low speed position by a spring. .

  As shown in FIG. 5, a pilot oil passage 85 extends from the oil passages 66 and 67 through a check valve 84, and a pilot operated pressure reducing valve 86 and a hydraulic clutch 59 are provided in series with the pilot oil passage 85. The pilot oil passage 87 branched from the oil passage 70 is connected to the operation portion of the pressure reducing valve 86. In the oil passage 61, a bypass oil passage 88 that bypasses the relief valve 62 is provided, and the bypass oil passage 88 is provided with an on-off valve 89, and the on-off valve 89 is a pilot operated type that is biased to an open position by a spring. It is configured. A pilot oil passage 90 is branched from the oil passage 80, a pilot oil passage 92 is extended from the pilot oil passages 85, 90 via a check valve 91, and the pilot oil passage 92 is connected to the operation portion of the on-off valve 89. ing.

[6]
Next, the configuration of the operation system of the right and left direction switching valves 68, 69, the pressure control valve 71, and the switching valves 74, 76, 79 will be described.
As shown in FIG. 7, the first speed change lever 94 is provided in the operating section 3, and the first speed change lever 94 and the shift gear 14 are mechanically linked through a linkage mechanism (not shown). When the first speed change lever 94 is operated to the low speed position and the high speed position, the shift gear 14 is operated, and the first transmission 19 is operated to the low speed position and the high speed position (see the previous item [2]).

  As shown in FIG. 7, the second speed change lever 95 (corresponding to an artificial operation tool), a steering lever 96 and a selection switch 97 are provided in the operating unit 3, and the second speed change lever 95, the steering lever 96 and the selection switch 97 are provided. Are input to the control device 100, and the second shift lever 95 is configured to be freely operated at a low speed position and a high speed position. Based on the second shift lever 95, the steering lever 96, and the selection switch 97, the control device 100 controls the right and left direction switching valves 68 and 69, the pressure control valve 71, and the switching valves 74, 76, and 79 as follows. The operation is performed as described in [7] to [12].

  As shown in FIGS. 3, 5, and 7, when the second shift lever 95 is operated to the low speed position, the switching valve 79 is operated to the low speed position, the hydraulic oil is discharged from the shift gear 20, and the shift gear 20 is discharged by the spring 21. Is engaged with the low-speed gear 17, the oil passage 82 is opened by the valve mechanism 83, the hydraulic oil is discharged from the hydraulic clutch 23, and the hydraulic clutch 23 is operated to be disconnected (the low-speed position of the second transmission device 28). (See previous paragraph [2]).

  As shown in FIGS. 3, 5, and 7, when the second speed change lever 95 is operated to the high speed position, the switching valve 79 is operated to the high speed position to supply hydraulic oil to the shift gear 20, and the shift gear 20 is connected to the low speed gear. 17, the oil passage 82 is closed by the valve mechanism 83, the hydraulic oil is supplied to the hydraulic clutch 23 through the accumulator 81, and the hydraulic clutch 23 is operated in the transmission state (second operation). (High-speed position of transmission 28) (Refer to [2] above).

  As shown in FIGS. 3, 5, and 7, when the second speed change lever 95 is operated to the high speed position, the pilot hydraulic oil in the oil passage 80 is opened and closed via the check valve 91 and the pilot oil passages 90 and 92. The on-off valve 89 is operated to the closed position. As a result, the hydraulic oil of the hydraulic pump 60 is supplied to the hydrostatic continuously variable transmission 9 via the relief valve 62, and the hydraulic oil of the hydraulic clutch 23 is secured.

[7]
Next, a case where the steering lever 96 is operated to the neutral position N will be described.
As shown in FIG. 7, the steering lever 96 is configured to be freely operated at a neutral position N, right and left first turning positions R1, L1, and right and left second turning positions R2, L2.

  As shown in FIGS. 2, 5, and 6, when the steering lever 96 is operated to the neutral position N, the right and left direction switching valves 68 and 69 are operated to the oil discharge position, and the operation cylinder 64 The transmission member 31 is operated to a transmission position where the transmission member 27 and the right traveling transmission gear 29 are engaged, and the left transmission member 32 is operated to a transmission position where the transmission member 27 and the left traveling transmission gear 30 are engaged. . The turning transmission member 54 is operated to a neutral position engaged with the transmission member 53 and the right and left turning transmission gears 55 and 56.

  As shown in FIGS. 2 and 6, in the state where the steering lever 96 is operated to the neutral position N, the power of the transmission member 27 is changed to the right transmission member 31, the right traveling transmission gear 29, and the transmission gears 40, 41. , 42 is transmitted to the right traveling device 1, and the power of the transmission member 27 is transmitted to the left transmission member 32, the left traveling transmission gear 30, the transmission gear 36, the transmission shaft 35, and the transmission gear 37, The aircraft is transmitted to the left traveling device 1 via 39 and goes straight.

  As shown in FIGS. 2, 5, and 6, in a state where the steering lever 96 is operated to the neutral position N, the hydraulic clutch 59 is operated to be disconnected, and the hydraulic oil of the hydraulic clutch 51 and the brake 52 is supplied to the pressure control valve 71. The hydraulic clutch 51 is operated in the disconnected state, and the brake 52 is operated in the released state. The shift member 44 is operated to a slow turning position or a reverse rotation position as described in [9] described later. The on-off valve 89 is operated to the open position, and hydraulic oil of the hydraulic pump 60 is preferentially supplied to the hydrostatic continuously variable transmission 9 through the bypass oil passage 88.

[8]
Next, a case where the steering lever 96 is operated to the right and left first turning positions R1, L1 will be described.
As shown in FIGS. 2, 5, and 6, when the steering lever 96 is operated to the right first turning position R1, the right direction switching valve 68 is operated to the supply position, and the operating cylinder 64 is moved to the left side of FIG. The right transmission member 31 is moved away from the right traveling transmission gear 29 in the state where the left transmission member 32 is operated to the transmission position where the left transmission member 32 is engaged with the transmission member 27 and the left traveling transmission gear 30. Operated to the operated blocking position. The swivel transmission member 54 is operated to the left in FIG. 3 and meshed with the transmission member 53 and the right swivel transmission gear 55, so that the swivel transmission gear 56 is moved to the right turn position operated from the left swivel transmission gear 56 to the separation side. Operated. By the pressure control valve 71 and the switching valve 72, the hydraulic clutch 51 is maintained in the disconnected state, and the brake 52 is maintained in the released state.

As shown in FIGS. 2 and 6, in the state where the steering lever 96 is operated to the right first turning position R <b> 1, the right transmission member 31 is moved to the cutoff position where it is operated away from the right traveling transmission gear 29. By being operated, transmission to the right traveling device 1 is cut off, and the right traveling device 1 is in a free rotating state.
In this case, as shown in FIG. 5, the pilot hydraulic oil in the oil passage 66 is supplied to the on-off valve 89 via the check valves 84, 91 and the pilot oil passages 85, 92, and the on-off valve 89 is operated to the closed position. Is done. Accordingly, the hydraulic oil of the hydraulic pump 60 is supplied to the hydrostatic continuously variable transmission 9 through the relief valve 62, and the hydraulic oil of the operation cylinder 64 is secured.

  As shown in FIGS. 2, 5, and 6, in the state where the steering lever 96 is operated to the right first turning position R <b> 1, the pilot hydraulic oil in the oil passage 66 is supplied with the check valve 84, the pilot oil passage 85, and the pressure reducing valve 86. Is supplied to the hydraulic clutch 59, and the hydraulic clutch 59 is operated in a transmission state. The hydraulic clutch 59 does not have such a strong force as to completely connect the transmission shaft 35 and the transmission gear 40, but transmits a little power of the transmission shaft 35 to the transmission gear 40 and transmits it to the right traveling device 1. It is. Thereby, the transmission to the right traveling device 1 is cut off, the right traveling device 1 is in a free rotation state, and the state in which a little power is transmitted to the right traveling device 1 via the hydraulic clutch 59. The aircraft gradually turns to the right from straight.

  Next, as shown in FIGS. 2, 5, and 6, when the steering lever 96 is operated to the left first turning position L1, the left direction switching valve 69 is operated to the supply position, and the operating cylinder 64 is operated as shown in FIG. The right transmission member 31 is operated to the transmission position where the right transmission member 31 is engaged with the transmission member 27 and the right traveling transmission gear 29, and the left transmission member 32 is moved to the left traveling transmission gear 30. Is operated to the blocking position operated to the separation side. The swivel transmission member 54 is operated to the right in FIG. 3 and is engaged with the transmission member 53 and the left swivel transmission gear 56, so that the swivel transmission member 54 is operated to the left swivel position operated from the right swivel transmission gear 55 to the separation side. Is done. The hydraulic clutch 51 is maintained in the disconnected state, and the brake 52 is maintained in the released state.

As shown in FIGS. 2 and 6, in a state where the steering lever 96 is operated to the first left turning position L1, the left transmission member 32 is moved to the cut-off position operated from the left traveling transmission gear 30 to the separation side. By being operated, transmission to the left traveling device 1 is cut off, and the left traveling device 1 enters a free rotating state.
In this case, as shown in FIG. 5, the pilot hydraulic oil in the oil passage 67 is supplied to the on-off valve 89 via the check valves 84, 91 and the pilot oil passages 85, 92, and the on-off valve 89 is operated to the closed position. Is done. Accordingly, the hydraulic oil of the hydraulic pump 60 is supplied to the hydrostatic continuously variable transmission 9 through the relief valve 62, and the hydraulic oil of the operation cylinder 64 is secured.

  As shown in FIGS. 2, 5, and 6, in the state where the steering lever 96 is operated to the left first turning position L <b> 1, the pilot hydraulic oil in the oil passage 67 is supplied with the check valve 84, the pilot oil passage 85, and the pressure reducing valve 86. Is supplied to the hydraulic clutch 59, and the hydraulic clutch 59 is operated in a transmission state. The hydraulic clutch 59 does not have such a strong force as to completely connect the transmission shaft 35 and the transmission gear 40, but transmits a little power of the transmission gear 40 to the transmission shaft 35 and transmits it to the left traveling device 1. It is. As a result, transmission to the left traveling device 1 is cut off, the left traveling device 1 is in a free rotating state, and a state where a little power is transmitted to the left traveling device 1 via the hydraulic clutch 59. The aircraft gradually turns to the left from the straight line.

[9]
Next, the selection switch 97 will be described.
As shown in FIG. 7, the selection switch 97 is configured to be freely operated at a slow turning position, a belief turning position, and a super turning position.

  As shown in FIGS. 2, 5, and 6, when the selection switch 97 is operated to the slow turning position, the switching valve 72 causes the switching valve 72 to supply the hydraulic oil to the first turning position (hydraulic clutch 51 by supplying hydraulic oil to the hydraulic clutch 51. 4 is operated to discharge the hydraulic oil from the brake 52 and operate the brake 52 to be released), the switching valve 76 is operated to the slow turning position, and the operation cylinder 77 is operated as shown in FIG. The shift member 44 is operated to the left side of the drawing, and the shift member 44 is operated to the slow turning position (the shift member 44 is engaged with the turning transmission shaft 43 and the spline portions 43a and 45a of the slow turning gear 45).

  As shown in FIGS. 2, 5, and 6, when the selection switch 97 is operated to the super turning position, the switching valve 72 causes the switching valve 72 to supply the hydraulic oil to the first turning position (hydraulic clutch 51 by supplying hydraulic oil). 51, the hydraulic fluid is discharged from the brake 52 and the brake 52 is released to operate the brake 52, the switching valve 76 is operated to the reverse rotation position, and the operation cylinder 77 is operated as shown in FIG. Acting to the right, the shift member 44 is operated to the reverse rotation position (the shift member 44 is engaged over the turning transmission shaft 43 and the spline portions 43a and 46a of the reverse rotation gear 46).

As shown in FIGS. 2, 5, and 6, when the selector switch 97 is operated from the slow turning position to the strong turning position, the switching valve 72 causes the switching valve 72 to discharge the hydraulic oil from the hydraulic clutch 51. Then, the hydraulic clutch 51 is operated to the disengaged state, the hydraulic oil is supplied to the brake 52 and the brake 52 is operated to the braking state), the switching valve 76 is operated to the reverse rotation position, and the shift is performed as described above. The member 44 is operated to the reverse rotation position.
When the selection switch 97 is operated from the super pivot position to the pivot position, the switch valve 72 is operated to the second swing position by the switching valve 74, and the switch valve 76 is operated to the slow swing position. As described above, the shift member 44 is operated to the gentle turning position.

  In this case, even if the switching valve 72 is operated to the first and second turning positions, if the steering lever 96 is operated to the neutral position N, the right or left first turning positions R1, L1, the pressure control valve 71 is operated. Thus, the hydraulic clutch 51 is operated in the disconnected state (the brake 52 is operated in the released state by the pressure control valve 71).

[10]
Next, a case where the steering lever 96 is operated to the right and left first turning positions R1, L1 and the right and left second turning positions R2, L2 in a state where the selection switch 97 is operated to the slow turning position will be described. .

  As shown in FIGS. 2, 5, and 6, in a state where the selection switch 97 is operated to the slow turning position (the brake 52 is maintained in the released state by the switching valve 72), the steering lever 96 is turned to the first right turn. When the position R1 is operated to the right second turning position R2 (the left first turning position L1 to the left second turning position L2), the operating oil in the operation cylinder 64 and the oil passage 70 is passed through the pressure control valve 71. The hydraulic clutch 51 is supplied to the hydraulic clutch 51, and the operating pressure of the hydraulic clutch 51 is increased in response to the operating position of the steering lever 96, and the hydraulic clutch 51 is operated to the transmission side. When operated to the second turning position R2 (left second turning position L2), the operating pressure of the hydraulic clutch 51 becomes the highest pressure (the hydraulic clutch 51 is operated to the transmission state).

  Accordingly, as shown in FIGS. 2, 5, and 6, the pilot hydraulic oil is supplied to the operating portion of the pressure reducing valve 86 through the pilot oil passage 87, and the hydraulic clutch 59 corresponds to the operating position of the steering lever 96. When the operating lever 96 is operated to the right second turning position R2 (left second turning position L2), the hydraulic clutch 59 is operated. Is cut off.

  As shown in FIGS. 2, 5, and 6, in the state where the steering lever 96 is operated from the right first turning position R1 to the right second turning position R2, the power of the low speed gear 25 and the high speed gear 26 is changed to the low speed gear. 26, the slow turning gear 45, the turning transmission shaft 43, the transmission gears 49 and 50, the hydraulic clutch 51 and the transmission shaft 24, and the transmission member 53 as low speed power in the same direction as the power of the low speed gear 25 and high speed gear 26. (Refer to the preceding paragraph [4]), the power of the transmission member 53 is transmitted to the right traveling device 1 via the turning transmission member 54, the right turning transmission gear 55, the transmission gears 41, 42, 58, and the right axle 32. Once transmitted, the aircraft turns slowly to the right.

  As shown in FIGS. 2, 5, and 6, in the state where the steering lever 96 is operated from the left first turning position L1 to the left second turning position L2, the power of the low speed gear 25 and the high speed gear 26 is changed to the low speed gear. 26, the slow turning gear 45, the turning transmission shaft 43, the transmission gears 49 and 50, the hydraulic clutch 51 and the transmission shaft 24, and the transmission member 53 as low speed power in the same direction as the power of the low speed gear 25 and high speed gear 26. The power of the transmission member 53 is transmitted to the left via the turning transmission member 54, the left turning transmission gear 56, the transmission gears 37, 39, 57, the transmission shaft 35, and the left axle 32. Transmitted to the traveling device 1, the aircraft turns slowly to the left.

  In this case, as shown in FIGS. 2, 5, and 6, the steering lever 96 is operated from the right first turning position R1 to the right second turning position R2 (the left first turning position L1 to the left second turning position L2). As the operating pressure of the hydraulic clutch 51 is increased, the hydraulic clutch 51 is operated to the transmission side, the operating pressure of the hydraulic clutch 59 is reduced, and the hydraulic clutch 59 is operated to the cutoff side. As the steering lever 96 is operated from the right first turning position R1 to the right second turning position R2 (the left first turning position L1 to the left second turning position L2), the turning radius of the right (left) gentle turning is increased. Is getting smaller.

[11]
Next, a case where the steering lever 96 is operated to the right and left first turning positions R1, L1 and the right and left second turning positions R2, L2 in a state where the selection switch 97 is operated to the belief turning position will be described. To do.

  As shown in FIGS. 2, 5, and 6, in a state where the selection switch 97 is operated to the pivot position (the hydraulic clutch 51 is maintained in the shut-off state by the switching valve 72), the steering lever 96 is moved to the right side. When the first turning position R1 is operated to the right second turning position R2 (the left first turning position L1 to the left second turning position L2), the operating oil in the operation cylinder 64 and the oil passage 70 causes the pressure control valve 71 to be moved. The operating pressure of the brake 52 is increased in response to the operating position of the steering lever 96, and the brake 52 is operated to the braking side. When operated to the second turning position R2 (left second turning position L2), the operating pressure of the brake 52 becomes the highest pressure (the brake 52 is operated to the braking state).

  Accordingly, as shown in FIGS. 2, 5, and 6, the pilot hydraulic oil is supplied to the operating portion of the pressure reducing valve 86 through the pilot oil passage 87, and the hydraulic clutch 59 corresponds to the operating position of the steering lever 96. When the operating lever 96 is operated to the right second turning position R2 (left second turning position L2), the hydraulic clutch 59 is operated. Is cut off.

  As shown in FIGS. 2, 5 and 6, the braking force of the brake 52 is transmitted via the transmission shaft 24 in a state where the steering lever 96 is operated from the right first turning position R <b> 1 to the right second turning position R <b> 2. The braking force of the transmission member 53 is transmitted to the member 53 (refer to the preceding item [4]), and the right traveling is performed via the turning transmission member 54, the right turning transmission gear 55, the transmission gears 41, 42, 58, and the right axle 32. Transmitted to the device 1, the aircraft turns to the right.

  As shown in FIGS. 2, 5 and 6, the braking force of the brake 52 is transmitted via the transmission shaft 24 in a state where the steering lever 96 is operated from the left first turning position L <b> 1 to the left second turning position L <b> 2. The braking force of the transmission member 53 is transmitted to the member 53 (see the preceding item [4]), and the braking force of the transmission member 53 is transmitted via the turning transmission member 54, the left turning transmission gear 56, the transmission gears 37, 39, 57, the transmission shaft 35, and the left axle 32. Is transmitted to the left traveling device 1 and the aircraft turns to the left.

  In this case, as shown in FIGS. 2, 5, and 6, the steering lever 96 is operated from the right first turning position R1 to the right second turning position R2 (the left first turning position L1 to the left second turning position L2). Accordingly, the operating pressure of the brake 52 is increased, the brake 52 is operated to the braking side, the operating pressure of the hydraulic clutch 59 is decreased, and the hydraulic clutch 59 is operated to the disengagement side. As the direction lever 96 is operated from the right first turning position R1 to the right second turning position R2 (left first turning position L1 to left second turning position L2), the turning radius of the right (left) belief turning becomes larger. It gets smaller.

[12]
Next, when the steering lever 96 is operated to the right and left first turning positions R1, L1 and the right and left second turning positions R2, L2 in a state where the selection switch 97 is operated to the super turning position. explain.

  As shown in FIGS. 2, 5, and 6, in the state where the selection switch 97 is operated to the super turning position (the brake 52 is maintained in the released state by the switching valve 72), the steering lever 96 is in the right position. When the first turning position R1 is operated to the right second turning position R2 (the left first turning position L1 to the left second turning position L2), the operating oil in the operation cylinder 64 and the oil passage 70 causes the pressure control valve 71 to be moved. The hydraulic clutch 51 is supplied to the hydraulic clutch 51, the operating pressure of the hydraulic clutch 51 is increased corresponding to the operating position of the steering lever 96, and the hydraulic clutch 51 is operated to the transmission side. When 96 is operated to the right second turning position R2 (left second turning position L2), the operating pressure of the hydraulic clutch 51 becomes the maximum pressure (the hydraulic clutch 51 is operated to the transmission state).

  Accordingly, as shown in FIGS. 2, 5, and 6, the pilot hydraulic oil is supplied to the operating portion of the pressure reducing valve 86 through the pilot oil passage 87, and the hydraulic clutch 59 corresponds to the operating position of the steering lever 96. When the operating lever 96 is operated to the right second turning position R2 (left second turning position L2), the hydraulic clutch 59 is operated. Is cut off.

  As shown in FIGS. 2, 5, and 6, in the state where the steering lever 96 is operated from the right first turning position R <b> 1 to the right second turning position R <b> 2, the power of the transmission shaft 16 is changed to the reverse gears 46, 47, It is transmitted to the transmission member 53 through the turning transmission shaft 43, transmission gears 49 and 50, the hydraulic clutch 51 and the transmission shaft 24 as power in the opposite direction to that of the low speed gear 25 and high speed gear 26 (previous item [4] The power of the transmission member 53 is transmitted to the right traveling device 1 via the turning transmission member 54, the right turning transmission gear 55, the transmission gears 41, 42, 58 and the right axle 32, and the airframe is turned to the right. Make a super turn.

  As shown in FIGS. 2, 5, and 6, in a state where the steering lever 96 is operated from the left first turning position L1 to the left second turning position L2, the power of the transmission shaft 16 is changed to the reverse gears 46, 47, It is transmitted to the transmission member 53 through the turning transmission shaft 43, transmission gears 49 and 50, the hydraulic clutch 51 and the transmission shaft 24 as power in the opposite direction to that of the low speed gear 25 and high speed gear 26 (previous item [4] The power of the transmission member 53 is transmitted to the left traveling device 1 via the turning transmission member 54, the left turning transmission gear 56, the transmission gears 37, 39, 57, the transmission shaft 35, and the left axle 32. The aircraft turns to the left.

  In this case, as shown in FIGS. 2, 5, and 6, the steering lever 96 is operated from the right first turning position R1 to the right second turning position R2 (the left first turning position L1 to the left second turning position L2). As the operating pressure of the hydraulic clutch 51 is increased, the hydraulic clutch 51 is operated to the transmission side, the operating pressure of the hydraulic clutch 59 is reduced, and the hydraulic clutch 59 is operated to the cutoff side. As the steering lever 96 is operated from the right first turning position R1 to the right second turning position R2 (the left first turning position L1 to the left second turning position L2), the right (left) super turning turn is performed. The turning radius becomes smaller.

[First Alternative Embodiment of the Invention]
In the above-described [Best Mode for Carrying Out the Invention], the first and second transmissions 19 and 28 shown in FIGS. 2 and 3 may be configured to be three-speed or four-speed.
When the first and second transmissions 19 and 28 are configured to be a three-speed transmission, for example, the first transmission 19 is operated to the second speed position and the second transmission 28 is operated to the second speed position And the transmission ratio in a state where the first transmission 19 is operated to the third speed position and the second transmission 28 is operated to the first speed position are set to the same (or substantially the same) transmission ratio. To do.
When the first and second transmissions 19 and 28 are configured to be a four-speed shift, for example, the first transmission 19 is operated to the fourth speed position and the second transmission 28 is operated to the second speed position. And the transmission ratio in a state where the first transmission 19 is operated to the third speed position and the second transmission 28 is operated to the third speed position are set to the same (or substantially the same) transmission ratio. To do.

[Second Embodiment of the Invention]
In the above-mentioned [Best Mode for Carrying Out the Invention] [First Alternative Embodiment], a push button type switch (not shown) is used as an artificial operation tool instead of the second shift lever 95. May be. A third transmission for traveling (not shown) is provided between the first transmission 19 and the transmission shaft 10, between the first transmission 19 and the second transmission 28, and on the lower transmission side of the second transmission 28. May be provided.

Combine side view Diagram showing the outline of the transmission system of the mission case Longitudinal front view in the vicinity of the first and second transmissions in the transmission case Longitudinal front view near the swivel transmission shaft in the mission case Hydraulic circuit diagram of second transmission, right and left transmission member, shift member, turning transmission member, hydraulic clutch, brake The states of the right and left transmission members, the turning transmission member, the shift member, the hydraulic clutch and the brake are shown in the state where the steering lever is operated to the neutral position, the right and left first turning positions, and the right and left second turning positions. Figure The figure which shows the linkage state of a shift lever, the 1st and 2nd shift lever, a steering lever, a selection switch, and a control apparatus. Longitudinal side view of sprockets and crawler belt cores in the right and left traveling devices

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traveling device 2 Cutting part 7 Engine 19 1st transmission 28 2nd transmission 79 Operation means 95 Artificial operation tool

Claims (2)

The power of the engine is branched into two systems, a transmission system to the cutting part and a transmission system to the traveling device, and the transmission system to the traveling device has a first transmission for traveling that can be shifted in multiple stages, and a plurality of stages. And a second transmission for traveling that can be freely shifted in series,
The transmission ratio when the first transmission is operated to the low speed position and the second transmission is operated to the high speed position, and the first transmission is operated to the high speed position and the second transmission is set to the low speed position. Set the transmission ratio in the operated state to the same transmission ratio,
When the first transmission is operated to the low speed position and the second transmission is operated to the high speed position, a cutting work speed is obtained, the first transmission is operated to the low speed position, and the second transmission is low speed. When it is operated to the position, it is configured to obtain a low speed cutting work speed,
When the first transmission is operated at a high speed position and the second transmission is operated at a high speed position, a moving speed is obtained, the first transmission is operated at a high speed position, and the second transmission is at a low speed position. A traveling shift structure of a harvesting and harvesting machine configured to obtain a harvesting operation speed when operated in the above manner.   The traveling shift structure of a harvesting harvester according to claim 1, further comprising: an artificial operation tool that is artificially operated; and an operation unit that operates the second transmission device based on an operation of the artificial operation tool.

Images