Work vehicles

Abstract

To provide a work vehicle that suppresses sudden acceleration and sudden deceleration of a work vehicle due to a difference between output rotations of a continuously variable transmission and prevents a behavior of the work vehicle from becoming unstable.SOLUTION: When a switch (19) is short pressed, if an operation attitude of a main shift lever (16) is in a rear-side inclined attitude more than a preset operation attitude of the main shift lever (16), the controller (60) accelerates or decelerates a continuously variable transmission (40) on the basis of the preset operation attitude of the main shift lever (16) and, if the operation attitude of the main shift lever (16) is in a front-side inclined attitude more than the preset operation attitude of the main shift lever (16), the controller (60) accelerates or decelerates the continuously variable transmission (40) on the basis of the operation attitude of the main shift lever (16).SELECTED DRAWING: Figure 6

Description

Technical Field

[0006] , , ,

[0005] , ,

[0001] The present invention relates to a work vehicle including a continuously variable transmission for increasing or decreasing the output rotation of an engine and a main transmission lever for operating the continuously variable transmission.

Background Art

[0002] Conventionally, in a work vehicle, a continuously variable transmission for increasing or decreasing the output rotation of an engine and a transmission are provided in the transmission path between the engine and the rear wheels. During work, the operation posture of the main transmission lever for operating the continuously variable transmission stored in a controller in advance and the shift position of the sub-transmission lever for operating the transmission are read, and the output rotation of the engine is increased or decreased based on the read operation posture of the main transmission lever and the shift position of the sub-transmission lever. A technology of a continuously variable transmission is known. (Patent Document 1)

Prior Art Documents

Patent Documents

[0003]

Patent Document - 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when there is a difference between the operation posture of the main transmission lever being operated by the operator and the operation posture of the main transmission lever stored in the read controller, there is a problem that the output rotation of the continuously variable transmission is different and the behavior of the work vehicle becomes unstable, such as sudden acceleration or sudden deceleration of the work vehicle.

[0005] Therefore, an object of the present invention is to provide a work vehicle that suppresses sudden acceleration or sudden deceleration of the work vehicle due to a difference in the output rotation of the continuously variable transmission and prevents the behavior of the work vehicle from becoming unstable.

Means for Solving the Problems

[0006] <° The present invention, which solves the above problems, is as follows. In other words, the invention described in claim 1 is a work vehicle in which a pair of front wheels (2) and rear wheels (3) are provided on the lower side of a machine frame (1) on which an engine (E) is mounted, and a control unit (5) on the upper side of the machine frame (1) on which an operator sits, A continuously variable transmission (CVT) (40) that increases or decreases the output rotation of the engine (E) is provided in the transmission path between the engine (E) and the rear wheel (3), and the control unit (5) is provided with a main shift lever (16) that changes the acceleration or deceleration of the CVT (40), a switch (19) that measures the operating position of the main shift lever (16), and a controller (60) that stores the operating position of the main shift lever (16) which is set in advance for each field, and the controller (60) when the main shift lever (16) is operated to a forward tilt position , with respect to the output rotation of the engine (E) Continuously variable transmission (40) Speed ​​increase rate When the main gear shift lever (16) is operated to a rearward tilt position, , with respect to the output rotation of the engine (E) Continuously variable transmission (40) Speed ​​increase rate The work vehicle is characterized by reducing the force, and when the switch (19) is briefly pressed, if the operating position of the main shift lever (16) is tilted to the rearward position than a preset operating position of the main shift lever (16), the controller (60) increases or decreases the speed of the continuously variable transmission (40) based on the preset operating position of the main shift lever (16), and if the operating position of the main shift lever (16) is tilted to the frontward position than a preset operating position of the main shift lever (16), the controller (60) increases or decreases the speed of the continuously variable transmission (40) based on the operating position of the main shift lever (16).

[0007] The invention described in claim 2 is a work vehicle according to claim 1, in which, while the controller (60) is changing the acceleration / deceleration of the continuously variable transmission (40) based on the operating position of the main transmission lever (16), if the operating position of the main transmission lever (16) becomes tilted to the rearward position than a preset operating position of the main transmission lever (16), the controller (60) performs acceleration / deceleration of the continuously variable transmission (40) based on the preset operating position of the main transmission lever (16).

[0008] The invention described in claim 3 is a work vehicle according to claim 1 or 2, wherein when the switch (19) is pressed and held down, the preset operating position of the main gear lever (16) is updated to the operating position of the main gear lever (16) when the switch (19) is pressed and held down.

[0009] The invention described in claim 4 is a work vehicle in which an engine (E) is mounted on a body frame (1), a pair of front wheels (2) and rear wheels (3) are provided on the lower side of the body frame (1), and a control unit (5) on the upper side of the body frame (1) is provided for the operator to sit in, A continuously variable transmission (CVT) (40) and a gearbox (42) are provided in the transmission path between the engine (E) and the rear wheel (3). The control unit (5) is provided with a main gear lever (16) for changing the acceleration and deceleration of the CVT (40), a sub-gear lever (17) for changing the acceleration and deceleration of the gearbox (42), a switch (19) for measuring the operating position of the main gear lever (16) and the gear position of the sub-gear lever (17), and a controller (60) for saving the operating position of the main gear lever (16) and the gear position of the sub-gear lever (17) that are set in advance for each field. The controller (60) is provided when the main gear lever (16) is operated to a forward tilt position. , with respect to the output rotation of the engine (E) Continuously variable transmission (40) Speed ​​increase rate When the main gear shift lever (16) is operated to a rearward tilt position, , with respect to the output rotation of the engine (E) Continuously variable transmission (40) Speed ​​increase rateWhen the switch (19) is briefly pressed, if the shift position of the sub-shift lever (17) matches the preset shift position of the sub-shift lever (17), and the operating position of the main shift lever (16) is tilted further back than the preset operating position of the main shift lever (16), the controller (60) increases or decreases the speed of the gearbox (42) based on the preset shift position of the sub-shift lever (17), and controls the continuously variable transmission based on the preset operating position of the main shift lever (16). The work vehicle is characterized in that, when the gear shift position of the sub-gear lever (17) differs from the preset gear shift position of the sub-gear lever (17), or when the operating position of the main gear lever (16) is tilted forward more than the preset operating position of the main gear lever (16), the controller (60) increases or decreases the gear of the gearbox (42) based on the gear shift position of the sub-gear lever (17) and increases or decreases the continuously variable transmission (40) based on the operating position of the main gear lever (16).

[0010] The invention described in claim 5 is a work vehicle according to claim 4, wherein the controller (60) changes the acceleration / deceleration of the transmission gearbox (42) based on the shift position of the sub-transmission lever (17), and while the controller (60) is changing the acceleration / deceleration of the continuously variable transmission (40) based on the operating position of the main transmission lever (16), if the shift position of the sub-transmission lever (17) coincides with a preset shift position of the sub-transmission lever (17), and the operating position of the main transmission lever (16) is in a rearward tilt position than a preset operating position of the main transmission lever (16), the controller (60) performs acceleration / deceleration of the transmission gearbox (42) based on the preset shift position of the sub-transmission lever (17) and acceleration / deceleration of the continuously variable transmission (40) based on the preset operating position of the main transmission lever (16).

[0011] The invention described in claim 6 is a work vehicle according to claim 4 or 5, wherein when the switch (19) is pressed and held, the preset operating position of the main transmission lever (16) and the shift position of the sub-transmission lever (17) are updated to the operating position of the main transmission lever (16) and the shift position of the sub-transmission lever (17) when the switch (19) is pressed and held. [Effects of the Invention]

[0012] According to the invention described in claim 1, a continuously variable transmission (40) for increasing or decreasing the output rotation of the engine (E) is provided in the transmission path between the engine (E) and the rear wheel (3), the control unit (5) is provided with a main shift lever (16) for changing the acceleration or deceleration of the continuously variable transmission (40), a switch (19) for measuring the operating position of the main shift lever (16), and a controller (60) for saving the operating position of the main shift lever (16) that is set in advance for each field, and the controller (60) when the main shift lever (16) is operated to a forward tilt position , relative to the engine (E) power rotation Continuously variable transmission (40) Speed ​​increase rate When the main gear shift lever (16) is operated to a rearward tilt position, , relative to the engine (E) power rotation Continuously variable transmission (40) Speed ​​increase rate By reducing the amount of force applied, if the operating position of the main transmission lever (16) is tilted further back than the preset operating position of the main transmission lever (16) when the switch (19) is briefly pressed, the controller (60) increases or decreases the speed of the continuously variable transmission (40) based on the preset operating position of the main transmission lever (16). If the operating position of the main transmission lever (16) is tilted further forward than the preset operating position of the main transmission lever (16), the controller (60) increases or decreases the speed of the continuously variable transmission (40) based on the operating position of the main transmission lever (16). As a result, the output rotation of the engine (E) is increased or decreased based on the preset increase or decrease of the continuously variable transmission (40), allowing the work vehicle to travel at a speed suitable for the field and to cultivate the field uniformly. Furthermore, a sudden decrease in the travel speed of the work vehicle due to a reduction in the increase or decrease of the continuously variable transmission (40) can be prevented, thereby suppressing a decrease in safety.

[0013] According to the invention described in claim 2, in addition to the effects of the invention described in claim 1, if the controller (60) is changing the acceleration / deceleration of the continuously variable transmission (40) based on the operating position of the main shift lever (16) and the operating position of the main shift lever (16) becomes tilted to the rearward position than the preset operating position of the main shift lever (16), the controller (60) will accelerate / deceleration the continuously variable transmission (40) based on the preset operating position of the main shift lever (16), so that the work vehicle can be driven at a travel speed suitable for the field and the field can be tilled more uniformly.

[0014] According to the invention described in claim 3, in addition to the effects of the invention described in claim 1 or 2, when the switch (19) is pressed and held down, the preset operating position of the main gear lever (16) is updated to the operating position of the main gear lever (16) when the switch (19) is pressed and held down. This allows the previously stored operating position of the main gear lever (16) to be updated to a more suitable operating position of the main gear lever (16), enabling more uniform tilling of the field.

[0015] According to the invention described in claim 4, a continuously variable transmission (40) and a gearbox (42) for increasing and decreasing the output rotation of the engine (E) are provided in the transmission path between the engine (E) and the rear wheel (3), and the control unit (5) is provided with a main gear lever (16) for changing the acceleration and deceleration of the continuously variable transmission (40), a sub-gear lever (17) for changing the acceleration and deceleration of the gearbox (42), a switch (19) for measuring the operating position of the main gear lever (16) and the gear position of the sub-gear lever (17), and a controller (60) for saving the operating position of the main gear lever (16) and the gear position of the sub-gear lever (17) that are set in advance for each field, and the controller (60) when the main gear lever (16) is operated to a forward tilt position , relative to the engine (E) power rotation Continuously variable transmission (40) Speed ​​increase rate When the main gear shift lever (16) is operated to a rearward tilt position, , relative to the engine (E) power rotation Continuously variable transmission (40) Speed ​​increase rateWhen the shift position of the sub-shift lever (17) is reduced and the switch (19) is briefly pressed, if the shift position of the sub-shift lever (17) matches the preset shift position of the sub-shift lever (17), and the operating position of the main shift lever (16) is tilted further back than the preset operating position of the main shift lever (16), the controller (60) increases or decreases the speed of the gearbox (42) based on the preset shift position of the sub-shift lever (17) and increases or decreases the speed of the continuously variable transmission (40) based on the preset operating position of the main shift lever (16), and the shift position of the sub-shift lever (17) matches the preset shift position of the sub-shift lever (17 If the gear position differs from that of the sub-gear lever (17), or if the operating position of the main gear lever (16) is tilted forward more than the preset operating position of the main gear lever (16), the controller (60) increases or decreases the speed of the gearbox (42) based on the gear position of the sub-gear lever (17) and increases or decreases the speed of the continuously variable transmission (40) based on the operating position of the main gear lever (16). This allows the output rotation of the engine (E) to be increased or decreased based on the preset increases or decreases of the continuously variable transmission (40) and the gearbox (42), enabling the work vehicle to travel at a suitable speed for the field and to cultivate the field uniformly. Furthermore, it is possible to prevent a sudden decrease in the travel speed of the work vehicle due to a reduction in the increases or decreases of the continuously variable transmission (40), etc., thereby suppressing a decrease in safety.

[0016] According to the invention described in claim 5, in addition to the effects of the invention described in claim 4, the controller (60) changes the acceleration / deceleration of the transmission gearbox (42) based on the shift position of the sub-transmission lever (17), and changes the acceleration / deceleration of the continuously variable transmission (40) based on the operating position of the main transmission lever (16). If the shift position of the sub-transmission lever (17) coincides with a preset shift position of the sub-transmission lever (17), and the operating position of the main transmission lever (16) is tilted further back than a preset operating position of the main transmission lever (16), the controller (60) accelerates / decelerates the transmission gearbox (42) based on the preset shift position of the sub-transmission lever (17) and accelerates / decelerates the continuously variable transmission (40) based on the preset operating position of the main transmission lever (16). This allows the work vehicle to travel at a speed suitable for the field, enabling more uniform tilling and other operations on the field.

[0017] According to the invention described in claim 6, in addition to the effects of the invention described in claim 4 or 5, when the switch (19) is long-pressed, the preset operating posture of the main transmission lever (16) and the gear shift position of the sub-transmission lever (17) are updated to the operating posture of the main transmission lever (16) and the gear shift position of the sub-transmission lever (17) when the switch (19) is long-pressed. Therefore, the preset operating posture of the main transmission lever (16) can be updated to a more suitable operating posture of the main transmission lever (16), and the preset gear shift position of the sub-transmission lever (17) can be updated to a more suitable gear shift position of the sub-transmission lever (17), and the tillage of the field can be made more uniform, such as tillage.

Brief Description of the Drawings

[0018] [Figure 1] It is a left side view of a work vehicle. [Figure 2] It is a perspective view of the driver's seat. [Figure 3] It is a transmission diagram of the output rotation of the engine. [Figure 4] It is a cross-sectional view of a continuously variable transmission. [Figure 5] It is a connection diagram of the controller [Figure 6] It is an operation method of the particular work.

Modes for Carrying Out the Invention

[0019] As shown in FIG. 1, a work vehicle such as a tractor is provided with a pair of left and right front wheels 2 at the front part below the body frame 1, and a pair of left and right rear wheels 3 at the rear part below the body frame 1.

[0020] A bonnet 4 for storing the engine E is provided at the front part above the body frame 1, a control unit 5 for the operator to board is provided at the rear side of the bonnet 4, and a PTO shaft 6 extending in the front-rear direction to which the output rotation of the engine E is transmitted is provided at the lower rear side of the control unit 5. A work implement 7 such as a manual spreader for spreading compost on the field is connected to the rear part of the PTO shaft 6.

[0021] A steering wheel 12 is provided in front of the cockpit 11 of the control unit 5, and a clutch pedal 14 is provided on the lower left side of the steering column 13, which houses the steering shaft supporting the steering wheel 12. In addition, a fender 15 is provided above the rear wheel 3 to cover the rear wheel 3.

[0022] As shown in Figure 2, a main shift lever 16 is provided at the front of the fender 15 located to the right of the cockpit 11, which rotates the trunnion shaft (not shown) of the continuously variable transmission 40 that increases and decreases the output rotation of the engine E. A sub-shift lever 17 is provided at the front of the fender 15 located to the left of the cockpit 11, which switches the gears of the transmission gearbox 42 that increases and decreases the output rotation of the continuously variable transmission 40. The operating position of the main shift lever 16 is measured by an angle sensor 16A, such as a potentiometer, attached to the base of the main shift lever 16, and the shift position of the sub-shift lever 17 is measured by an angle sensor 17A, such as a potentiometer, attached to the base of the sub-shift lever 17.

[0023] To the right of the main gear shift lever 16 is a selection dial 18 for selecting a file 64 that stores setting values ​​such as the driving conditions of the work vehicle stored in the memory unit 62 of the controller 60. Behind the selection dial 18 is a read / write switch (the "switch" in the claim) 19 for reading the measured values ​​of the angle sensor 16A and the angle sensor 17A. To the right of the read / write switch 19 is a control switch 20 that drives the work vehicle based on the operating position of the main gear shift lever 16 and the gear shift position of the sub-gear shift lever 17 stored in the file 64.

[0024] As shown in Figure 3, the output rotation of engine E is transmitted to the input shaft 40A of the continuously variable transmission 40. The output rotation transmitted to the input shaft 40A is increased or decreased by the continuously variable transmission 40, and the output rotation increased or decreased by the continuously variable transmission 40 is output from the first output shaft 40B and the second output shaft 40C.

[0025] When the "こだわり" switch 20 is not activated, i.e., during normal operation, the output rotation of the engine E is increased or decreased by the continuously variable transmission 40 based on the operating position of the main shift lever 16 being operated by the operator. When the main shift lever 16 is operated to the rearmost tilt position, the acceleration rate of the continuously variable transmission 40 becomes 0%, and as the main shift lever 16 is operated from the rearward tilt position to the forward tilt position, the acceleration rate of the continuously variable transmission 40 increases, and when the main shift lever 16 is operated to the frontmost tilt position, the acceleration rate of the continuously variable transmission 40 becomes 100%, and if the output rotation of the engine E is 1500 rps, the output rotation of the continuously variable transmission 40 will increase to 3000 rps.

[0026] When the "こだわり" switch 20 is activated, i.e., during "こだわり" operation, the operating position of the main transmission lever 16 read by the angle sensor 16A when the read / write switch 19 is briefly pressed is compared with the operating position of the main transmission lever 16 stored in file 64. If the read operating position of the main transmission lever 16 is tilted further back than the stored operating position of the main transmission lever 16, the output rotation of the engine E is increased by the speed increase rate of the continuously variable transmission 40 based on the operating position of the main transmission lever 16 stored in file 64. For example, if the speed increase rate of the continuously variable transmission 40 for the read operating position of the main transmission lever 16 is 20%, and the speed increase rate of the continuously variable transmission 40 for the stored operating position of the main transmission lever 16 is 30%, the speed increase rate of the continuously variable transmission 40 is set to 30%. This allows the engine E's output speed to be increased based on a preset speed increase rate of the continuously variable transmission 40, enabling the vehicle to travel at a suitable speed for the field and cultivate the field uniformly. Furthermore, the selection dial 18 can be used to create and retrieve a file 64 containing the optimal speed increase rate of the continuously variable transmission 40 for each field.

[0027] On the other hand, if the operating position of the main transmission lever 16 that has been read is tilted forward more than the operating position of the main transmission lever 16 that has been retracted, the output rotation of the engine E will be increased by the rate of increase of the continuously variable transmission 40 based on the operating position of the main transmission lever 16 that has been read. For example, if the rate of increase of the continuously variable transmission 40 in the operating position of the main transmission lever 16 that has been read is 50%, and the rate of increase of the continuously variable transmission 40 in the operating position of the main transmission lever 16 that has been retracted is 30%, then the rate of increase of the continuously variable transmission 40 will be set to 50%. This prevents a sudden deceleration of the driving speed due to a decrease in the rate of increase of the continuously variable transmission 40, thereby suppressing a decrease in safety.

[0028] In this case, if the operating position of the main transmission lever 16 being operated by the operator remains tilted forward compared to the stored operating position of the main transmission lever 16, the speed increase rate of the continuously variable transmission 40 is set based on the operating position of the main transmission lever 16 being operated by the operator. If the operating position of the main transmission lever 16 being operated by the operator is tilted backward compared to the stored operating position of the main transmission lever 16, the speed increase rate of the continuously variable transmission 40 is set based on the operating position of the main transmission lever 16 stored in file 64.

[0029] The output rotation of the first output shaft 40B is transmitted to the input shaft of the transmission gearbox 42 via the clutch 41. The clutch 41 is engaged and disengaged by pressing the clutch pedal 14. The output rotation of the continuously variable transmission 40 is increased or decreased in the transmission gearbox 42 and output from the output shaft of the transmission gearbox 42. When the clutch 41 is disengaged, it is preferable to change the operating position of the main transmission lever 16 stored in the file 64 to a rearward tilt position. This prevents a sudden acceleration of the driving speed due to an increase in the acceleration rate of the continuously variable transmission 40 when the clutch 41 is engaged again, thereby suppressing a decrease in safety.

[0030] When the "こだわり" switch 20 is not activated, i.e., during normal operation, the output rotation of the continuously variable transmission 40 is increased or decreased by the gearbox 42 according to the gear position of the sub-gear lever 17. When the sub-gear lever 17 is operated to 1st gear, the speed increase rate of the gearbox 42 becomes 0%, and as the sub-gear lever 17 is operated from 1st gear to 3rd gear, the speed increase rate of the gearbox 42 increases, and when the sub-gear lever 17 is operated to 3rd gear, the speed increase rate of the gearbox 42 becomes 20%, and if the output rotation of the continuously variable transmission 40 is 3000 rps, the output rotation of the gearbox 42 will increase to 3600 rps.

[0031] When the "こだわり" switch 20 is activated, i.e., during a "こだわり" operation, the shift position of the sub-transmission lever 17 read by the angle sensor 17A when the read / write switch 19 is briefly pressed is compared with the shift position of the sub-transmission lever 17 stored in the file 64. If the read shift position of the sub-transmission lever 17 and the stored shift position of the sub-transmission lever 17 match, the operating posture of the main transmission lever 16 read by the angle sensor 16A when the read / write switch 19 is briefly pressed is compared with the operating posture of the main transmission lever 16 stored in the file 64.

[0032] If the reading operating position of the main transmission lever 16 is tilted further back than the stored operating position of the main transmission lever 16, the output rotation of the engine E is increased by the speed increase rate of the continuously variable transmission 40 based on the operating position of the main transmission lever 16 stored in file 64. For example, if the speed increase rate of the continuously variable transmission 40 for the reading operating position of the main transmission lever 16 is 20%, and the speed increase rate of the continuously variable transmission 40 for the stored operating position of the main transmission lever 16 is 30%, then the speed increase rate of the continuously variable transmission 40 is set to 30%. This allows the engine E's output rotation to be increased based on the preset speed increase rate of the continuously variable transmission 40, and the output rotation of the continuously variable transmission 40 to be increased or decreased at the preset gearbox 42 shift position, enabling the vehicle to travel at a suitable speed for the field and cultivate the field uniformly.

[0033] On the other hand, if the operating position of the main transmission lever 16 that has been read is tilted forward more than the operating position of the main transmission lever 16 that has been retracted, the output rotation of the engine E will be increased by the rate of increase of the continuously variable transmission 40 based on the operating position of the main transmission lever 16 that has been read. For example, if the rate of increase of the continuously variable transmission 40 in the operating position of the main transmission lever 16 that has been read is 50%, and the rate of increase of the continuously variable transmission 40 in the operating position of the main transmission lever 16 that has been retracted is 30%, then the rate of increase of the continuously variable transmission 40 will be set to 50%. This prevents a sudden deceleration of the driving speed due to a decrease in the rate of increase of the continuously variable transmission 40, thereby suppressing a decrease in safety.

[0034] In this case, if the operating position of the main transmission lever 16 being operated by the operator remains tilted forward compared to the stored operating position of the main transmission lever 16, the speed increase rate of the continuously variable transmission 40 is set based on the operating position of the main transmission lever 16 being operated by the operator. If the operating position of the main transmission lever 16 being operated by the operator is tilted backward compared to the stored operating position of the main transmission lever 16, the speed increase rate of the continuously variable transmission 40 is set based on the operating position of the main transmission lever 16 stored in file 64.

[0035] When the read / write switch 19 is briefly pressed, the shift position of the sub-transmission lever 17 read by the angle sensor 17A is compared with the shift position of the sub-transmission lever 17 stored in the file 64. If the read shift position of the sub-transmission lever 17 and the stored shift position of the sub-transmission lever 17 do not match, the acceleration rate of the continuously variable transmission 40 is set based on the operating position of the main transmission lever 16, and the gears of the transmission gearbox 42 are switched based on the shift position of the sub-transmission lever 17. This prevents the start of unintended work against the operator's will and suppresses a decrease in safety.

[0036] In this case, the speed increase rate of the continuously variable transmission 40 is set based on the operating position of the main transmission lever 16 being operated by the operator, and the gears of the transmission gearbox 42 are switched based on the shift position of the auxiliary transmission lever 17 being operated by the operator. If the shift position of the auxiliary transmission lever 17 being operated by the operator matches the shift position of the stored auxiliary transmission lever 17, the operating position of the main transmission lever 16 being operated by the operator is compared with the operating position of the main transmission lever 16 stored in file 64.

[0037] The output rotation of the output shaft of the transmission gearbox 42 is transmitted via bevel gears to the input shaft of the differential gear 43 for the rear wheels, and via gears to the rotating shaft 46. The output rotation, which has been increased or decreased by the differential gear 43, is output to the left and right drive shafts 44, and the output rotation of the drive shafts 44 is transmitted to the left and right pair of rear wheels 3 via the left and right pair of wheels.

[0038] The output rotation of the rotating shaft 46 is transmitted to the input shaft of the differential gear 48 for the front wheels via a clutch 47 for four-wheel drive. The clutch 47 is switched on and off by operating a four-wheel drive lever (not shown) located on the fender. The output rotation, which has been increased or decreased by the differential gear 48, is output to the left and right drive shafts 49, and the output rotation of the left and right drive shafts 49 is transmitted to the left and right pair of front wheels 2 via a left and right pair of wheels.

[0039] The output rotation of the second output shaft 40C is transmitted to the input shaft of the PTO gearbox 51 via the PTO clutch 50. The clutch 50 is engaged and disengaged by operating a clutch lever (not shown) provided on the control unit 5. The output rotation, which has been increased / decelerated or its direction of output rotation switched by the PTO gearbox 51, is output from the output shaft.

[0040] The output rotation of the output shaft of the PTO variable speed gearbox 51 is transmitted to the rotary shaft 52, and the output rotation of the rotary shaft 52 is transmitted to the PTO shaft 6 via gears.

[0041] As shown in Figure 4, the continuously variable transmission 40 has a pump chamber 55 and a motor chamber 56. The pump chamber 55 is equipped with a variable displacement hydraulic pump 55A and a swash plate 55B, and the motor chamber 56 is equipped with a fixed displacement hydraulic motor 56A and a swash plate 56B.

[0042] When the main shift lever 16 is operated from a rearward tilt position to a forward tilt position, the trunnion shaft rotates, increasing the tilt angle of the swash plate 55B, which increases the capacity of the hydraulic pump 55A and allows the output rotation speed of the hydraulic motor 56A to be increased. In this specification, the tilt angle of the swash plate 55B refers to the angle at which the swash plate 55B tilts forward from a position in which it is perpendicular to the input shaft 40A.

[0043] On the other hand, when the main shift lever 16 is operated from a forward tilt position to a rearward tilt position, the trunnion shaft rotates, reducing the tilt angle of the swash plate 55B, decreasing the capacity of the hydraulic pump 55A, and slowing down the output rotation of the hydraulic motor 56A. When the main shift lever 16 is moved to the rear end, the swash plate 55B becomes perpendicular to the input shaft 40A, the capacity of the hydraulic pump 55A becomes zero, and the output rotation of the hydraulic motor 56A stops.

[0044] As shown in Figure 5, the controller 60 is composed of a processing unit 61 consisting of a CPU and the like, a storage unit 62 consisting of ROM, RAM, a hard disk drive, flash memory and the like, and a communication unit 63 for data communication with the outside.

[0045] The processing unit 61 compares the operating position of the main shift lever 16 and the shift position of the sub-shift lever 17 stored in the file 64 selected by the selection dial 18 with the operating position of the main shift lever 16 and the shift position of the sub-shift lever 17 when the read / write switch 19 is briefly pressed.

[0046] The memory unit 62 stores a file 64 containing the operating position of the main transmission lever 16 and the shift position of the sub-transmission lever 17, which are set in advance for each field.

[0047] The communication unit 63 transmits and receives data with a portable controller (not shown).

[0048] The input side of the controller 60 is connected via a predetermined input interface circuit to a clutch pedal 14 for connecting and disconnecting the drive clutch 41 and the PTO clutch 50, an angle sensor 16A for measuring the operating position of the main shift lever 16, an angle sensor 17A for measuring the shift position of the sub-shift lever 17, a selection dial 18 for selecting a file 64 corresponding to each field, a read / write switch 19 for reading and writing measured values ​​from the angle sensor 16A and other sensors to the file 64, and a control switch 20 for driving the continuously variable transmission 40 and the like based on the operating position of the main shift lever 16 and the like stored in the file 64.

[0049] The output side of the controller 60 is connected to a continuously variable transmission 40, a drive clutch 41, a transmission gearbox 42, and a PTO clutch 50 via a predetermined output interface circuit.

[0050] <How to use the advanced features> As shown in Figure 6, during normal operation in which an operator operates the main shift lever 16 and the sub-shift lever 17 to change the speed increase rate of the continuously variable transmission 40 and the gears of the gearbox 42, in step S1, the processing unit 61 of the controller 60 determines whether or not the "こだわりswitch 20" has been activated. If it is determined that the "こだわりswitch 20" has not been activated, the process proceeds to step S2; if it is determined that the "こだわりswitch 20" has been activated, the process proceeds to step S7.

[0051] In step S2, the processing unit 61 determines whether the read / write switch 19 has been pressed for approximately 2 seconds or longer. If it determines that the read / write switch 19 has been pressed, the unit proceeds to step S3; otherwise, it proceeds to step S4.

[0052] In step S3, the processing unit 61 reads the measurement value from the angle sensor 16A, calculates the operating position of the main shift lever 16 based on the read measurement value, changes the operating position of the main shift lever 16 that is previously stored in the storage unit 62 of the controller 60 to the newly calculated operating position of the main shift lever 16, and proceeds to step S4. This makes it possible to change the previously stored operating position of the main shift lever 16 to a more suitable operating position of the main shift lever 16, enabling more uniform tilling of the field. In this embodiment, the previously stored operating position of the main shift lever 16 is stored in association with the shift position of the sub-shift lever 17, which is 1st to 3rd gear.

[0053] In step S4, the processing unit 61 reads the measurement value from the angle sensor 16A, calculates the operating position of the main shift lever 16 based on the read measurement value, and compares the calculated operating position of the main shift lever 16 with the operating position of the main shift lever 16 stored in the storage unit 62 of the controller 60. If the calculated operating position of the main shift lever 16 is tilted further back than the operating position of the main shift lever 16 stored in the storage unit 62 of the controller 60, the process proceeds to step S5. If the calculated operating position of the main shift lever 16 is tilted further forward than the operating position of the main shift lever 16 stored in the storage unit 62 of the controller 60, the process returns to step S1. This prevents a sudden deceleration of the travel speed due to a decrease in the rate of increase of the output rotation of the continuously variable transmission 40, thereby suppressing a decrease in safety.

[0054] In step S5, the processing unit 61 rotates the trunnion shaft of the continuously variable transmission 40 based on the operating position of the main shift lever 16 stored in the memory unit 62, regardless of the operating position of the main shift lever 16, and proceeds to step S6. This allows tilling work to be performed at the optimal speed increase rate of the continuously variable transmission 40 for the field, and enables more uniform tilling of the field.

[0055] In step S6, the processing unit 61 determines whether the sub-transmission lever 17 has been operated or whether the read / write switch 19 has been pressed or pressed for a long time. If it determines that neither the sub-transmission lever 17 nor the read / write switch 19 has been operated, the unit returns to step S5. If it determines that neither the sub-transmission lever 17 nor the read / write switch 19 has been operated, the unit returns to step S1.

[0056] In step S7, the processing unit 61 reads the file 64 selected by the selection dial 18 and proceeds to step S8.

[0057] In step S8, the processing unit 61 determines whether the read / write switch 19 has been pressed for approximately 2 seconds or longer. If it determines that the read / write switch 19 has been pressed, the process proceeds to step S9; otherwise, the process proceeds to step S10.

[0058] In step S9, the processing unit 61 reads the measured values ​​from angle sensor 16A and angle sensor 17A, calculates the operating position of the main transmission lever 16 and the shift position of the sub-transmission lever 17 based on the read measured values, changes the operating position of the main transmission lever 16 and the shift position of the sub-transmission lever 17 stored in the selected file 64 to the newly calculated operating position of the main transmission lever 16 and the shift position of the sub-transmission lever 17, and proceeds to step S10. This allows the previously saved operating position of the main transmission lever 16 and the shift position of the sub-transmission lever 17 to be changed to a more suitable operating position of the main transmission lever 16 and the shift position of the sub-transmission lever 17, enabling more uniform tilling of the field.

[0059] In step S10, the processing unit 61 reads the measurement value from the angle sensor 17A, calculates the shift position of the sub-transmission lever 17 based on the read measurement value, and compares the calculated shift position of the sub-transmission lever 17 with the shift position of the sub-transmission lever 17 stored in the selected file 64. If the calculated shift position of the sub-transmission lever 17 matches the shift position of the sub-transmission lever 17 stored in the selected file 64, the process proceeds to step S11. If the calculated shift position of the sub-transmission lever 17 does not match the shift position of the sub-transmission lever 17 stored in the selected file 64, the process returns to step S1.

[0060] In step S11, the processing unit 61 reads the measurement value from the angle sensor 16A, calculates the operating position of the main shift lever 16 based on the read measurement value, and compares the calculated operating position of the main shift lever 16 with the operating position of the main shift lever 16 stored in the storage unit 62 of the controller 60. If the calculated operating position of the main shift lever 16 is tilted further back than the operating position of the main shift lever 16 stored in the storage unit 62 of the controller 60, the process proceeds to step S12. If the calculated operating position of the main shift lever 16 is tilted further forward than the operating position of the main shift lever 16 stored in the storage unit 62 of the controller 60, the process returns to step S1. This prevents a sudden deceleration of the travel speed due to a decrease in the rate of increase of the output rotation of the continuously variable transmission 40, thereby suppressing a decrease in safety.

[0061] In step S12, the processing unit 61 rotates the trunnion shaft of the continuously variable transmission 40 based on the operating position of the main shift lever 16 stored in the memory unit 62, regardless of the operating position of the main shift lever 16, and proceeds to step S13. This allows tilling work to be performed at the optimal speed increase rate of the continuously variable transmission 40 for the field, and enables more uniform tilling of the field.

[0062] In step S13, the processing unit 61 determines whether the sub-transmission lever 17, the selection dial 18, or the read / write switch 19 has been operated (long press or short press). If it determines that the sub-transmission lever 17, the selection dial 18, and the read / write switch 19 have not been operated, the unit returns to step S12. If it determines that any of the sub-transmission lever 17, the selection dial 18, or the read / write switch 19 has been operated, the unit returns to step S1. [Explanation of symbols]

[0063] 1. Aircraft frame 2 Front wheels 3 Rear wheels 5. Control Unit 16 Main gear shift lever 17. Sub-transmission lever 19. Reading Switch (Switch) 40 Continuously Variable Transmission 42 Gearbox 60 Controllers E-engine

Claims

1. In a work vehicle having a frame (1) on which an engine (E) is mounted, a pair of front wheels (2) and rear wheels (3) on the lower side, and a control unit (5) on the upper side of the frame (1) where a worker sits, A continuously variable transmission (40) that increases or decreases the output rotation of the engine (E) is provided in the transmission path between the engine (E) and the rear wheel (3). The control unit (5) is provided with a main shift lever (16) for changing the acceleration and deceleration of the continuously variable transmission (40), a switch (19) for measuring the operating position of the main shift lever (16), and a controller (60) for saving the operating position of the main shift lever (16) that is set in advance for each field. The controller (60) increases the rate of increase of the continuously variable transmission (40) relative to the output rotation of the engine (E) when the main shift lever (16) is operated to a forward tilt position, and decreases the rate of increase of the continuously variable transmission (40) relative to the output rotation of the engine (E) when the main shift lever (16) is operated to a rearward tilt position. If the switch (19) is briefly pressed and the operating position of the main shift lever (16) is tilted further back than the preset operating position of the main shift lever (16), the controller (60) increases or decreases the speed of the continuously variable transmission (40) based on the preset operating position of the main shift lever (16). A work vehicle characterized in that, when the operating position of the main shift lever (16) is tilted forward more than a preset operating position of the main shift lever (16), the controller (60) increases or decreases the speed of the continuously variable transmission (40) based on the operating position of the main shift lever (16).

2. The work vehicle according to claim 1, wherein, while the controller (60) is changing the acceleration / deceleration of the continuously variable transmission (40) based on the operating position of the main shift lever (16), if the operating position of the main shift lever (16) becomes tilted to the rearward position than a preset operating position of the main shift lever (16), the controller (60) accelerates or decelerates the continuously variable transmission (40) based on the preset operating position of the main shift lever (16).

3. The work vehicle according to claim 1 or 2, wherein when the switch (19) is pressed and held, the preset operating position of the main gear lever (16) is updated to the operating position of the main gear lever (16) when the switch (19) is pressed and held.

4. In a work vehicle having an engine (E) mounted on a frame (1) with a pair of front wheels (2) and rear wheels (3) on the lower side, and a control unit (5) on the upper side of the frame (1) where an operator sits, A continuously variable transmission (40) and a gearbox (42) are provided in the transmission path between the engine (E) and the rear wheel (3) to increase or decrease the output rotation of the engine (E). The control unit (5) is provided with a main shift lever (16) for changing the acceleration and deceleration of the continuously variable transmission (40), a sub-shift lever (17) for changing the acceleration and deceleration of the transmission gearbox (42), a switch (19) for measuring the operating position of the main shift lever (16) and the shift position of the sub-shift lever (17), and a controller (60) for saving the operating position of the main shift lever (16) and the shift position of the sub-shift lever (17) that are set in advance for each field. The controller (60) increases the rate of increase of the continuously variable transmission (40) relative to the output rotation of the engine (E) when the main shift lever (16) is operated to a forward tilt position, and decreases the rate of increase of the continuously variable transmission (40) relative to the output rotation of the engine (E) when the main shift lever (16) is operated to a rearward tilt position. When the switch (19) is briefly pressed, if the gear shift position of the auxiliary gear lever (17) coincides with a preset gear shift position of the auxiliary gear lever (17), and the operating position of the main gear lever (16) is tilted further back than a preset operating position of the main gear lever (16), the controller (60) increases or decreases the speed of the gearbox (42) based on the preset gear shift position of the auxiliary gear lever (17), and increases or decreases the speed of the continuously variable transmission (40) based on the preset operating position of the main gear lever (16). A work vehicle characterized in that, if the gear position of the auxiliary gear lever (17) differs from the preset gear position of the auxiliary gear lever (17), or if the operating position of the main gear lever (16) is tilted forward more than the preset operating position of the main gear lever (16), the controller (60) increases or decreases the speed of the gearbox (42) based on the gear position of the auxiliary gear lever (17) and increases or decreases the speed of the continuously variable transmission (40) based on the operating position of the main gear lever (16).

5. The work vehicle according to claim 4, wherein the controller (60) changes the acceleration / deceleration of the transmission gearbox (42) based on the shift position of the sub-transmission lever (17), and while the controller (60) is changing the acceleration / deceleration of the continuously variable transmission (40) based on the operating position of the main transmission lever (16), if the shift position of the sub-transmission lever (17) coincides with a preset shift position of the sub-transmission lever (17), and the operating position of the main transmission lever (16) is tilted further back than a preset operating position of the main transmission lever (16), the controller (60) performs acceleration / deceleration of the transmission gearbox (42) based on the preset shift position of the sub-transmission lever (17) and acceleration / deceleration of the continuously variable transmission (40) based on the preset operating position of the main transmission lever (16).

6. The work vehicle according to claim 4 or 5, wherein when the switch (19) is pressed and held, the preset operating position of the main transmission lever (16) and the shift position of the sub-transmission lever (17) are updated to the operating position of the main transmission lever (16) and the shift position of the sub-transmission lever (17) when the switch (19) is pressed and held.

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