JP2004017912A - Work vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize planting posture and an amount of fertilizer, for example, in a rice transplanter, by maintaining the working speed under work to the constant, and also to improve operation efficiency by enabling stable traveling which does not receive the influence of the traveling load, and by enhancing travelability. <P>SOLUTION: The work vehicle is equipped with a continuously variable transmission 57 continuously changing working speed, a speed detection means 134 detecting the working speed, and a constant speed setting means 140 maintaining the working speed to the setting speed. The continuously variable transmission 57 is increasingly/decreasingly controlled so as to maintain the setting speed of the constant speed setting means 140. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a work vehicle such as a rice transplanter, a tractor, a combine, or a construction machine that continuously performs a seedling operation with a seedling mounting table and a seedling mounting claw.
[0002]
[Problems to be solved by the invention]
Conventionally, as the vehicle speed control of a rice transplanter, when the running load increases and the engine speed decreases, control is performed to reduce the running load by decelerating a belt-type continuously variable transmission (CVT). However, in such control, the planting posture of the seedlings and the amount of fertilization are not stable because the vehicle speed fluctuates due to the running load.
[0003]
[Means for Solving the Problems]
Therefore, the present invention comprises a continuously variable transmission for continuously changing the working speed, speed detecting means for detecting the working speed, and constant speed setting means for maintaining the working speed at the set speed. By controlling the continuously variable transmission to increase or decrease the speed so as to maintain the speed, to keep the working speed constant, for example, in the case of a rice transplanter, to stabilize the planting posture and fertilizer application amount, and not to be affected by the running load. It enables stable running, improves running performance, and improves work efficiency.
[0004]
In addition, the control range of the continuously variable transmission is made larger than the shift range of the shift operation member for performing the shift operation of the continuously variable transmission, and the working speed is higher than the working speed of the highest speed position of the shift operation member due to the increase of the traveling load. This makes it possible to perform control in the case where it is necessary to stably maintain the work speed and improve the work efficiency.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is an overall side view, FIG. 2 is a plan view of the same, FIG. 3 is a side view of a vehicle body frame, and FIG. 4 is a plan view of the same. In the drawing, reference numeral 1 denotes a traveling vehicle on which an operator rides; It is mounted on the vehicle body frame 3 to support a paddy field traveling front wheel 6 on a side of the transmission case 4 via a front axle case 5, and a rear axle case 7 behind the transmission case 4 supports a paddy field rear wheel 8. A spare seedling mounting table 10 is mounted on both sides of the hood 9 covering the engine 2 and the like, and the transmission case 4 and the like are covered by a body cover 11 on which an operator rides. The driver's seat 13 is attached to the vehicle, and a steering handle 14 is provided in front of the driver's seat 13 and at the rear of the hood 9.
[0006]
In the figure, reference numeral 15 denotes a planting section provided with a seedling mounting table 16 for five-row planting and a plurality of seedling mounting claws 17 and the like. The planting case 20 is supported by the planting case 20 via the lower rail 18 and the guide rail 19 so as to be reciprocally slidable left and right, and a rotary case 21 that rotates at a constant speed in one direction is supported by the planting case 20. A pair of claw cases 22 are arranged at symmetrical positions about the axis, and seedling-planting claws 17 are attached to tips of the claw cases 22.
[0007]
Further, the hitch bracket 23 on the front side of the planting case 20 is connected to the rear side of the traveling vehicle 1 via a lifting link mechanism 26 including a top link 24 and a lower link 25, and the planting section 15 is raised and lowered via the link mechanism 26. A hydraulic raising / lowering cylinder 27 to be connected is connected to the lower link 25, and the front and rear wheels 6.8 are driven and moved. It is configured to take out and continuously perform rice transplanting to plant seedlings.
[0008]
In the drawing, 28 is a main shift lever, 29 is a planting operation lever for raising / lowering the planting section 15, turning on / off the planting clutch, and operating the marker, 30 is a brake pedal, 31 is a speed change pedal, 32 is a differential lock pedal, 33 is a sensitivity adjusting lever, 34 is a stop lever for stopping the planted portion 15 at an arbitrary height position, 35 is a unit clutch lever 35, which is a speed change / elevation lever 28/29 near the position of the steering handle 14, a brake and a speed change. The pedals 30 and 31 are arranged, and the sensitivity adjustment and stop and unit clutch levers 33, 34 and 35 are arranged near the position of the driver's seat 13.
[0009]
Further, in the drawing, 36 is a center float for equalizing one line, 37 is a side float for equalizing two lines, and 38 is a float 36 for feeding fertilizer in a fertilizer hopper 39 by a blower 40 through a flexible transfer hose 41. A 5-row side fertilizer that is discharged to 37 side-row cropping devices 42.
[0010]
As shown in FIGS. 3 to 5, the body frame 3 is divided into a front frame 43, an intermediate frame 44, and a rear frame 45, and the engine 2 is mounted on the pair of left and right front frames 43 and the pair of left and right intermediate frames 44. A front axle case 5 is provided, and a pair of left and right rear frames 45 are provided with a rear axle case 7, a fuel tank 46 for supplying fuel to the engine 2, and the like. Are connected to form a quadrangular frame shape in a plan view, and the engine 2 is mounted on the fixed bracket 49 and the base frame 48 via vibration-proof rubber.
[0011]
As shown in FIG. 10, a portal frame 53 that connects the middle rising portion 50 of the rear frame 45 substantially in parallel with a pipe frame 51 and a portal frame 52, and that fixes the left and right lower ends to the rear axle case 7. And the fuel tank 46 is disposed between the right and left rising portions 50.
[0012]
Further, the front and rear ends of the left and right intermediate frames 44 are detachably fixed to the rear end of the front frame 43 and the front end of the rear frame 45 via bolts 54, and the left and right front axle cases are fixed to the lower surfaces of the left and right intermediate frames 44 via bolts 55. The left and right front axle cases 5 are connected and fixed to the transmission case 4.
[0013]
As shown in FIGS. 6 to 10, a power steering case 56 is provided on the front left side of the transmission case 4 and a continuously variable hydraulic transmission 57 is provided on the right side of the case 4, and a shift input pump shaft 58 of the hydraulic transmission 57 is provided. , The pump shaft 58 is connected to a transmission shaft 59 in the front-rear direction below the engine 2, and the transmission shaft 59 is connected to an output shaft 60 of the engine 2 via a transmission belt 61. The two outputs are transmitted to the hydraulic transmission 57.
[0014]
Further, the transmission case 4 and the rear axle case 7 are integrally connected by a pipe-shaped connection frame 62 on the center line in the front-rear direction of the vehicle body, and a rear output shaft 63 and a PTO output shaft 64 are protruded to the rear of the transmission case 4. The rear output shaft 63 is connected via a rear transmission shaft 66 to a rear input shaft 65 protruding forward from the case 7, and power is transmitted from the traveling output shaft 63 to the left and right rear wheels 8. Further, the PTO output shaft 64 is connected via a universal joint shaft 69 to an intermediate shaft 68 provided on a bearing 67 on the upper part of the rear axle case 7, and the intermediate shaft 68 is connected via an universal joint shaft to the input shaft of the planting case 20. Then, power is transmitted from the PTO output shaft 64 to the planting section 15.
[0015]
Further, as shown in FIGS. 11 to 16, the transmission case 4 includes a main body 70, a front cover 71, and a rear cover 72, and each of the covers 71, 72 is provided before and after the body 70. It is detachably bolted and formed into a closed box shape, and a partition wall portion 73 for dividing the inside of the body portion 70 into front and rear portions is provided. Further, the hydraulic transmission 57 is mounted on the front surface of the front cover 71, and a small-diameter transmission gear 74 is engaged with a pump shaft 58 projecting into the transmission case 4. Then, the power of the transmission gear 74 is transmitted via a pipe shaft 76 to a charge pump 75 fixed to the rear surface of the rear lid 72.
[0016]
A sun gear 78 is engaged with a motor shaft 77 of the hydraulic transmission 57 projecting into the transmission case 4, and the sun gear 78 is bearing-beared on the front cover 71. The carrier gear 79 having a diameter is always meshed with the boss portion of the sun gear 78 so that the carrier gear 79 is rotatably supported. The carrier gear 79 is provided with three planetary gears 80 rotatably via a shaft 81, and And a ring gear 82 meshing with the planetary gear 80 is provided, and the planetary gear mechanism 83 is formed by the gears 78, 80 and 82.
[0017]
The sun gear 78 and the rear lid 72 rotatably support the combined output shaft 84 back and forth, and the ring gear 82 is engaged with the combined output shaft 84 for engagement. And the forward / reverse rotation output of the hydraulic motor 86, which is a continuously variable hydraulic transmission output, and the reduced rotation output (constant rotation in one direction) of the transmission gear 74 and the carrier gear 79 are synthesized by the differential action of the planetary gear mechanism 83, and Or transmitted to the combined output shaft 84 as a rotational force in one direction at the maximum speed. That is, the rotation of the motor shaft 77 when the angle of the hydraulic shift operation arm 109 for changing the swash plate 107 of the hydraulic pump 85 of the hydraulic transmission 57 is changed from −1 to 0 as shown in FIG. When the gear 74 is rotated 1000 times irrespective of the angle of the arm 109 as shown in FIG. 17 (2), the combined output shaft with respect to the angle of the arm 109 as shown in FIG. The rotation of 84 is set to 0 to 1000.
[0018]
Further, a forward gear 87 and a reverse gear 88 are rotatably supported on the combined output shaft 84, and the respective gears 87 and 88 are selectively engaged with the combined output shaft 84 by a slider 89, so that forward, neutral or reverse output is performed. And the rear output shaft 63 is bearing-supported on the partition wall 73 and the rear lid 72. Further, a front output shaft 92 for transmitting power to the left and right front axles 91 via a differential gear 90 and a counter shaft 94 for engaging and supporting a PTO transmission gear 93 are provided, and the rear and front output shafts 63 and 92 are provided. The reverse power is transmitted to the front and rear wheels 6.8 through output gears 95 and 96 to drive the front and rear wheels 6.8 backward, and the rear output shaft 63 supports the moving gear 97 and the planting gear 98 for free rotation. The gears 97 and 98 are selectively engaged with the rear output shaft 63 by the speed change slider 99.
[0019]
Further, the moving gear 97 is always meshed with the forward gear 87 via the high-speed gears 100a and 100b of the counter shaft 94, and the planting gear 98 is always meshed with the low-speed PTO gear 93 of the counter shaft 94. The power of the forward gear 87 is transmitted to the output shafts 63 and 92 via the gears 100a, 93 and 98, and the front and rear wheels 6.8 are driven forward at the seeding planting operation speed. Further, both the moving gear 97 and the planting gear 98 are in the idle state, and the manual rotation of the PTO output shaft 64 is performed so that the worker can manually rotate the planting claws 17 and the like to remove the clogged seedlings. At the same time, the power of the forward gear 87 is transmitted to the output shafts 63 and 92 via the gears 100a and 100b, and the front and rear wheels 6.8 are driven forward at a high speed such as on the road between fields. .
[0020]
Further, as shown in FIG. 11, the power of the PTO transmission gear 93 is transmitted to the PTO output shaft 64 via the PTO transmission shaft 101 and the PTO transmission mechanism 102 to drive the planting section 15 so as to be able to perform the inter-stock transmission and to transmit the transmission case 4. The fertilizer output shaft 104 is connected to the PTO output shaft 64 via a chain 103 installed inside the fertilizer, and the fertilizer applicator 38 is driven in synchronization with the planting unit 15. Further, as shown in FIG. 13, an oil gauge 105 is provided on the transmission case 4, and the sliders 89 and 99 are locked on the same shift fork 106 as shown in FIG. It switches between forward and reverse and sub-speed (low speed).
[0021]
As shown in FIG. 16, a hydraulic shift operation arm 109 is connected to a swash plate 107 of the hydraulic pump 85 via a control shaft 108, and a speed change motor 110 is connected to the arm 109. The rotation output of the hydraulic motor 86 is configured to be increased or decreased. The speed change motor 110 is installed on a motor base 110 a connected to the front frame 43.
[0022]
Also, a traveling brake 111 is provided on a front output shaft 92 connected to the front axle 91 via a differential gear 90, and a brake pedal 30 is connected via a brake rod 113 to a brake operation shaft 112 protruding above the transmission case 4. The operation of the brake pedal 30 activates the brake 111 to stop the travel of the aircraft.
[0023]
As shown in FIGS. 11, 12, and 16, a ball joint type main clutch 114 is interposed between the ring gear 82 and the forward gear 87 of the composite output shaft 84, and the clutch is attached to the clutch shaft 115 protruding outside the transmission case 4. The brake pedal 30 is connected via an arm 116 to operate the shift fork 106 of the clutch shaft 115 to deactivate the main clutch 114 at the time of stepping on the brake pedal 30 for stopping the body.
[0024]
As shown in FIGS. 19 to 22, a speed change pedal 31 is disposed on the right side of the brake pedal 30. The speed change pedal 31 is swingably supported on a pedal shaft 118 via a pedal arm 119, and the speed change pedal 31 is An arm 120 to be integrally connected is provided on a pedal shaft 118, and a spring 127 for automatically returning the pedal 31 to a stop (zero speed) position when the foot is released from the pedal 120 is opposed to an oil damper 128 (or a gas spring). When the foot is released from the pedal 31 which has been depressed, the pedal 31 returns slowly at a substantially constant speed due to the resistance of the oil damper 128 and the return power of the spring 127, and gradually becomes slow. .
[0025]
As shown in FIG. 22, a detection rod 130 is fixed to the other end of the pedal arm 119, and the detection rod 130 is brought into contact with the sensor arm 132 of the potentiometer-type pedal position sensor 131 so that the pedal arm 119 is depressed. The operation position is detected by the sensor 131.
[0026]
Also, as shown in FIG. 2, an automatic cruise switch 140 for automatic cruise control for controlling the drive of the transmission motor 110 to maintain a constant working speed such as a running speed, and a transmission 57 of the transmission 57 for the same operation amount of the transmission pedal 31. A slow speed switch 141 for changing the speed (speed ratio) to change the working speed to a slow speed, and an escape switch 143 for controlling the optimum escape vehicle speed when the front wheel 6 or the rear wheel is fitted in the field. An auto cruise lamp 144 for displaying an auto cruise control that is lit when the auto cruise switch 140 is turned on, a slow speed setting display lamp 145 for displaying a slow speed control that is lit when the slow speed switch 141 is turned on, and an escape switch. An escape mode display lamp 146 that is lit and displayed in an escape mode in which the 143 is on; A switch-off warning device 147 for warning that the switch-off is not possible is provided. These switches 140, 141, 143 and lamps 144, 145, 146 are arranged on the upper surface of the operation column 9a near the steering handle 14 in front of the driver's seat 13. Thus, the switches 140, 141, and 143 can be easily operated and the operations can be confirmed.
[0027]
Further, as shown in FIG. 16, an electric motor driven cooling fan 142 is installed near the hydraulic transmission 57, and the transmission 57 is externally cooled by the cooling air from the cooling fan 142 so that the inside of the transmission 57 is cooled. It is configured to suppress an increase in the oil temperature.
[0028]
As shown in FIG. 23, an engine rotation sensor 133 for detecting the rotation speed of the engine 2, a vehicle speed sensor 134 for detecting the vehicle speed from the rotation of the rear or front output shafts 63 and 92, and a stepping operation of the brake pedal 30 A brake pedal switch 135 for detecting (ON), a planting position sensor 136 for detecting a planting (low-speed forward) position by the main shift lever 28, and a shift position sensor 137 for detecting a shift position of the operation arm 109. An oil temperature sensor (such as a thermistor) 138 for detecting the oil temperature of the hydraulic transmission 57; a transmission oil pressure sensor 139 for detecting the oil pressure of the hydraulic transmission 57; the auto cruise switch 140; And the escape switch 143 are input connected to the controller 148, and the speed change motor 1 The controller 148 is connected to the drive circuit 149, the cooling fan 142, the auto cruise lamp 144, the slow speed setting display lamp 145, the escape mode display lamp 146, and the alarm device 147 so that the controller 148 is connected thereto. It is configured to perform drive control of the 146 and the alarm device 147.
[0029]
In the embodiment, the configuration in which the brake pedal 30 and the travel brake 111 are mechanically connected via the brake rod 113 or the like has been described. However, a brake drive mechanism for electrically operating the travel brake 111 is provided. The operation of the travel brake 111 and the on / off operation of the main clutch 114 may be performed by operating the brake pedal switch 135 using the pedal 30.
[0030]
The present embodiment is configured as described above. In the normal shift control, the operation amount of the shift pedal 31 is detected by the pedal position sensor 131, and the position corresponding to the operation amount (the shift position sensor 137 is detected). In the automatic cruise control, when the auto cruise switch 140 is operated during traveling, the operation of the switch 140 is controlled. 24, the speed of the transmission 57 is controlled to increase or decrease via the speed change motor 110 so as to maintain the detection value of the vehicle speed sensor 134, so that the vehicle speed is kept constant. As shown in FIG. When the switch 140 is turned on (set), the auto cruise lamp 143 is turned on and the traveling speed at that time is stored as the set speed, After that, the automatic cruise control is performed by the speed change motor 110 that keeps the set speed constant, and the lamp 143 blinks (temporarily completes) until the speed change pedal 31 reaches the lowest speed (not depressed), and the speed becomes the lowest speed. At this time, the lamp 143 is turned on to start the control. If the speed change pedal 31 does not return to the minimum speed within a predetermined time, the switch 140 is not turned on and the lamp 143 is turned off.
[0031]
When the operation of the brake pedal 30 or the speed change pedal 31 is detected by the brake pedal switch 135 or the pedal position sensor 131, the lamp 143 flashes, and the auto cruise control is performed with the auto cruise mode (set speed storage) maintained. Release and return to normal control (change of vehicle speed by operation of shift pedal 31) to perform work other than planting such as turning and seedling connection, and run for a certain period of time at a speed higher than the initially set auto cruise speed. At this time, the lamp 143 is turned on to automatically shift to the original auto cruise state again.
[0032]
The auto cruise switch 140 can be turned off only in the auto cruise mode while the lamp 143 is blinking, and when the switch 140 is off, the auto cruise mode is turned off to return to normal shift control.
[0033]
As shown in FIG. 25, the control range L1 of the continuously variable transmission 57 is set to be larger on the high-speed side than the operation range L2 of the speed change pedal 31, and when the control range L1 has the maximum value, for example, the maximum rotation speed of the engine 2 The vehicle speed v2 (≒ 1.3 m / s), which is the maximum value of the pedal operation range L2, is made smaller (v1> v2) than the vehicle speed v1 (≒ 1.45 m / s), and is affected by running load and the like. It enables high-precision auto-cruise control without any problems. Although the configuration in which the continuously variable transmission 57 is controlled to increase or decrease the speed is shown, a configuration in which the rotation speed of the engine 2 is controlled (the throttle opening is controlled by an actuator) may be used.
[0034]
Also, as shown in FIG. 26, when the front wheel 6 or the rear wheel 8 is stuck in the field, the vehicle speed is automatically controlled to an optimum speed for escape so that the escape can be performed. When the vehicle speed v is 0 and the vehicle is stopped, the escape mode indicator lamp 146 is turned on, the transmission 57 is returned to the minimum speed (prevention of sudden deceleration due to erroneous operation), and the operation of the transmission 57 by the shift pedal 31 is performed. When the gear ratio is larger than the current gear ratio, the transmission 57 is driven to gradually increase (increase) the gear ratio, and the current vehicle speed v becomes larger than the set vehicle speed v1, which is the reference escape vehicle speed for determining that the vehicle has escaped. When the vehicle speed sensor 134 detects "Large", it is determined that the escape is completed. When the current gear ratio of the transmission 57 is smaller (slower) than the gear ratio of the speed change pedal 31, the current gear ratio is maintained, and when the gear ratio of the speed change pedal 31 becomes lower than the current gear ratio, the vehicle escapes. The mode display lamp 146 is turned on to return to the normal control, thereby preventing sudden acceleration or the like when returning to the normal control with the operator depressing the shift pedal 31 to the maximum at the time of escape.
[0035]
Even when the transmission 57 is driven to increase the speed ratio (increased speed), the vehicle speed v is lower than the set speed v1 (v1>v> 0). (Deceleration) control, and when the vehicle speed v is in the stopped state and the output of the engine rotation is low, the alarm device 147 is activated to lower the speed ratio of the transmission 57.
[0036]
As described above, the vehicle speed is detected by the vehicle speed sensor 134 and the engine speed is detected by the engine speed sensor 131, and the transmission 57 is controlled so as to maintain the optimum vehicle speed for escape during the output reduction (stall) of the transmission 57 and the engine 2. , So that a smooth escape can be easily performed.
[0037]
As is apparent from the above description, the continuously variable transmission 57 for continuously changing the working speed, the vehicle speed sensor 134 as speed detecting means for detecting the working speed, and the constant speed setting means for maintaining the working speed at the set speed. An automatic cruise switch 140 is provided, and by controlling the continuously variable transmission 57 to increase or decrease the speed so as to maintain the set speed of the auto cruise switch 140, the work speed during the work is maintained at a constant level. In addition to stabilizing the planting posture and the amount of fertilizer applied, it enables stable running without being affected by the running load, thereby improving running performance and improving work efficiency.
[0038]
Further, since the control range L1 of the continuously variable transmission 57 is set to be larger than the operation range L2 which is the shift range of the transmission pedal 31 which is the shift operation member for performing the shift operation of the continuously variable transmission 57, the traveling load increases. Thus, it is possible to perform control when a work speed higher than the work speed of the highest speed position of the speed change pedal 31 is required, to stably maintain the work speed, and to improve work efficiency.
[0039]
【The invention's effect】
As is apparent from the above embodiment, the present invention is characterized by a continuously variable transmission 57 for continuously changing the working speed, a speed detecting means 134 for detecting the working speed, and a constant speed setting means 140 for maintaining the working speed at a set speed. The stepless transmission 57 is controlled to increase or decrease the speed so that the speed set by the constant speed setting means 140 is maintained. In addition to stabilizing the mounting posture and the amount of fertilization, it enables stable running without being affected by the running load, thereby improving running performance and improving work efficiency.
[0040]
Further, since the control range L1 of the continuously variable transmission 57 is made larger than the shift range L2 of the transmission operation member 31 for performing the shift operation of the continuously variable transmission 57, the maximum speed of the transmission operation member 31 is increased by increasing the traveling load. It is possible to perform control when a work speed higher than the work speed at the position is required, to stably maintain the work speed, and to improve work efficiency.
[Brief description of the drawings]
FIG. 1 is an overall side view of a rice transplanter.
FIG. 2 is an overall plan view of the rice transplanter.
FIG. 3 is a side view of the traveling vehicle body.
FIG. 4 is a plan view of a traveling vehicle body.
FIG. 5 is a side view of the vehicle body frame.
FIG. 6 is an explanatory side view of a driving unit.
FIG. 7 is an explanatory plan view of a driving unit.
FIG. 8 is an explanatory side view of a side clutch operation system.
FIG. 9 is an explanatory plan view of a side clutch operation system.
FIG. 10 is an explanatory perspective view of a vehicle body.
FIG. 11 is a sectional view of a transmission case.
FIG. 12 is an explanatory diagram of the traveling drive unit.
FIG. 13 is an explanatory diagram of a planetary gear mechanism.
FIG. 14 is a partial view of a mission case.
FIG. 15 is a sectional view of a planetary gear mechanism.
FIG. 16 is an explanatory diagram of gear arrangement of a transmission case.
FIG. 17 is an explanatory diagram of output.
FIG. 18 is an explanatory diagram of an output of a combined output shaft.
FIG. 19 is an explanatory perspective view of an operation unit.
FIG. 20 is an explanatory side view of the operation unit.
FIG. 21 is an explanatory perspective view of a pedal unit.
FIG. 22 is a side view of the speed change pedal unit.
FIG. 23 is a control circuit diagram.
FIG. 24 is a flowchart of auto cruise control.
FIG. 25 is an explanatory diagram of a control range of the transmission.
FIG. 26 is a flowchart of escape control.
[Explanation of symbols]
31 Speed change pedal (speed change operation member)
57 continuously variable transmission 134 vehicle speed sensor (speed detection means)
140 Auto cruise switch (speed detection means)
L1 control range L2 operation range (shift range)

Claims (2)

A continuously variable transmission for continuously changing the working speed, speed detecting means for detecting the working speed, and constant speed setting means for maintaining the working speed at the set speed, wherein the set speed of the constant speed setting means is maintained. A work vehicle characterized in that the continuously variable transmission is controlled to increase or decrease in speed. 2. The work vehicle according to claim 1, wherein a control range of the continuously variable transmission is set to be larger than a shift range of a shift operation member that shifts the continuously variable transmission.

Images