Work vehicles

Abstract

The present invention provides a work vehicle that can reduce the amount of uncut grass by preventing grass from slipping through the gap between the teeth of the left blade and the right blade of the mowing device when the work vehicle turns. [Solution] The mowing device (4) is formed of a mower deck (81) and a left blade (80L) and a right blade (80R) for mowing grass, which are rotatably supported on the mower deck (81). The machine frame (1) and the mower deck (81) are connected by a left arm (84) formed to a predetermined length in the front-rear direction and a right arm (85) whose length in the front-rear direction is extendable and retractable. In the front-rear direction, the left rotation axis (88L) of the left blade (80L) is positioned in front of the right rotation axis (88R) of the right blade (80R). When the work vehicle is turned to the right, the right arm (85) is extended forward, and the mower deck (81) is rotated counterclockwise, bringing the right rotation axis (88R) closer to the left rotation axis (88L) in the front-rear direction.

Description

Technical Field

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[0001] The present invention relates to a work vehicle for mowing turfgrass.

Background Art

[0002] Conventionally, in order to prevent contact between a left blade disposed on the left side and a right blade disposed on the right side of a mowing work device for mowing turfgrass provided on the front side of a machine body frame, a technique of providing the left blade in front of the right blade in the front-rear direction is known. (Patent Document 1)

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, with the means of Patent Document 1, when the work vehicle makes a right turn to the right side of the traveling direction, there is a risk that the turfgrass may slip through between the left blade and the right blade, resulting in uncut turfgrass.

[0005] <0000​​​​​​​​​​​The mowing device (4) is formed by a mower deck (81) and a left blade (80L) and a right blade (80R) for mowing grass, which are rotatably supported on the mower deck (81). The machine frame (1) and the mower deck (81) are connected by a left arm (84) formed to a predetermined length in the front-rear direction and a right arm (85) whose length in the front-rear direction is extendable and retractable. In the front-rear direction, the left rotation axis (88L) of the left blade (80L) is positioned in front of the right rotation axis (88R) of the right blade (80R). When the work vehicle is turned to the right, the right arm (85) is extended forward, rotating the mower deck (81) counterclockwise, bringing the right rotation axis (88R) closer to the left rotation axis (88L) in the front-rear direction.

[0007] The invention described in claim 2 is a work vehicle having a machine frame (1) with a pair of left and right front wheels (2) and rear wheels (3) on the lower side, a grass cutting device (4) for cutting grass on the front side of the machine frame (1), and a control unit (5) for the operator to sit on on the rear side of the grass cutting device (4), The mowing device (4) is formed by a mower deck (81) and a left blade (80L) and a right blade (80R) for mowing grass, which are rotatably supported on the mower deck (81). The machine frame (1) and the mower deck (81) are connected by a left arm (84) formed to a predetermined length in the front-rear direction and a right arm (85) whose length in the front-rear direction is extendable and retractable. In the front-rear direction, the right rotation axis (88R) of the right blade (80R) is positioned in front of the left rotation axis (88L) of the left blade (80L). When the work vehicle is turned to the left, the right arm (85) is shortened to the rear, and the mower deck (81) is rotated clockwise, bringing the left rotation axis (88L) closer to the right rotation axis (88R) in the front-rear direction.

[0008] The invention described in claim 3 is a work vehicle according to claim 1 or 2, wherein the extension and retraction of the right arm (85) is stopped when the rotation of the left blade (80L) and the right blade (80R) is stopped.

[0009] The invention described in claim 4 is a work vehicle according to claim 1 or 2, wherein the extension and retraction of the right arm (85) is stopped when the harvesting device (4) is raised from a working position to a retraction position.

[0010] The invention described in claim 5 is a work vehicle according to claim 1, wherein a buzzer (87) provided on the control unit (5) sounds when the mower deck (81) has been rotated counterclockwise for a predetermined amount of time.

[0011] The invention described in claim 6 is a work vehicle according to claim 2, wherein when the mower deck (81) is rotated clockwise and a predetermined time has elapsed in that state, a buzzer (87) provided on the control unit (5) sounds. [Effects of the Invention]

[0012] According to the invention described in claim 1, the mowing device (4) is formed of a mower deck (81) and a left blade (80L) and a right blade (80R) for mowing grass, which are rotatably supported on the mower deck (81), and the machine frame (1) and the mower deck (81) are connected by a left arm (84) formed to a predetermined length in the front-rear direction and a right arm (85) whose length in the front-rear direction is extendable and retractable, and in the front-rear direction, the left rotation axis (88L) of the left blade (80L) is connected to the right rotation axis (88R) of the right blade (80R) When positioned further forward and the work vehicle is turned to the right, the right arm (85) extends forward, and the mower deck (81) rotates counterclockwise, bringing the right rotation axis (88R) closer to the left rotation axis (88L) in the front-rear direction. As a result, the right rotation axis (88R) of the right blade (80R) approaches the left rotation axis (88L) of the left blade (80L), allowing the right blade (80R) to cut the grass passing between the left blade (80L) and the right blade (80R), thus suppressing any uncut grass.

[0013] According to the invention described in claim 2, the mowing device (4) is formed of a mower deck (81) and a left blade (80L) and a right blade (80R) for mowing grass, which are rotatably supported on the mower deck (81), and the machine frame (1) and the mower deck (81) are connected by a left arm (84) formed to a predetermined length in the front-rear direction and a right arm (85) whose length in the front-rear direction is extendable and retractable, and in the front-rear direction, the right rotation axis (88R) of the right blade (80R) is connected to the left rotation axis (88L) of the left blade (80L) When positioned further forward and the work vehicle is turned to the left, the right arm (85) is shortened to the rear, and the mower deck (81) is rotated clockwise, bringing the left rotation axis (88L) closer to the right rotation axis (88R) in the front-rear direction. As a result, the left rotation axis (88L) of the left blade (80L) approaches the right rotation axis (88R) of the right blade (80R), and the grass passing between the left blade (80L) and the right blade (80R) is cut by the left blade (80L), suppressing the leaving of grass uncut.

[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 rotation of the left blade (80L) and the right blade (80R) is stopped, the extension and retraction of the right arm (85) is stopped, thereby suppressing unnecessary extension and retraction of the right arm (85) and allowing for efficient use of the output rotation of the electric motor.

[0015] According to the invention described in claim 4, in addition to the effects of the invention described in claim 1 or 2, when the harvesting device (4) is raised from the working position to the retraction position, the extension and retraction of the right arm (85) is stopped, thereby suppressing unnecessary extension and retraction of the right arm (85) and allowing for efficient use of the output rotation of the electric motor.

[0016] According to the invention described in claim 5, in addition to the effects of the invention described in claim 1, if the mower deck (81) has been rotated counterclockwise for a predetermined amount of time, a buzzer (87) provided on the control unit (5) sounds, thereby preventing operator error and shortening the harvesting time.

[0017] According to the invention described in claim 6, in addition to the effects of the invention described in claim 2, when the mower deck (81) is rotated clockwise and a predetermined time set in advance has elapsed, the buzzer (87) provided in the control unit (5) sounds, thus preventing an operator from making an incorrect operation and shortening the mowing operation time.

Brief Description of the Drawings

[0018] [Figure 1] It is a perspective view of the work vehicle as seen from the front left side. [Figure 2] It is a perspective view of the front part of the electric room as seen from the rear left side. [Figure 3] It is a perspective view of the rear part of the electric room as seen from the rear left side. [Figure 4] It is a perspective view of the electric motor and the gear case as seen from the front left side. [Figure 5] It is a perspective view of the electric motor and the gear case as seen from the rear left side. [Figure 6] It is a rear view of the electric motor and the gear case. [Figure 7] It is a sectional view of the broken left part of the gear case. [Figure 8] It is a transmission diagram of the output rotation of the electric motor. [Figure 9] It is a perspective view of the battery as seen from the rear left side. [Figure 10] It is a plan view of the battery mounted in the electric room. [Figure 11] It is a plan view of the electric motor and the inverter device. [Figure 12] It is a left side view of the electric motor and the inverter device. [Figure 13] It is a left side view of the electric room. [Figure 14] It is a perspective view of the electric room as seen from the rear right side. [Figure 15] It is a plan view for explaining the forward posture of the mower deck of the mowing work device. [Figure 16] It is a plan view for explaining the right rotation posture of the mower deck of the mowing work device. [Figure 17] It is a connection diagram of the controller. [Figure 18] This is a flowchart of a method for changing the posture of the mower deck when a work vehicle equipped with the harvesting device of the first embodiment turns to the right. [Figure 19] This is a flowchart of a method for changing the posture of the mower deck when a work vehicle equipped with the harvesting device of the second embodiment turns left. [Modes for carrying out the invention]

[0019] As shown in Figure 1, the work vehicle has a pair of front wheels 2 on the lower front part of the machine frame 1, and a pair of rear wheels 3 on the lower rear part of the machine frame 1.

[0020] The front of the machine frame 1 is equipped with a mowing device 4 for cutting grass growing in the field, and the rear of the mowing device 4 is equipped with a control unit 5 where the operator sits. Behind the control unit 5 is a safety frame (rops) 6 for protecting the operator, and behind the safety frame 6 is equipped with a grass collection container 7 for storing the cut grass. Below the grass collection container 7 is an electric motor room 8 where the electric motor 30 and battery 60 for driving the mowing device 4 are located.

[0021] A steering column is provided in front of the operator's seat of the control unit 5, which houses the shaft supporting the steering wheel 10. The operating angle of the steering wheel 10 is detected by an angle sensor 10S, such as a potentiometer, located at the bottom of the shaft.

[0022] A touch-panel monitor displaying the output rotation speed of the electric motor 30 is provided at the top of the steering column, a brake pedal 11 for reducing the rotation speed of the front wheels 2 is provided on the left side of the lower part of the steering column, and an accelerator pedal 12 for increasing or decreasing the output rotation speed of the electric motor 40 that drives the front wheels 2 is provided on the right side.

[0023] The area above the front wheel 2 is covered by a fender 13. A lifting lever 14 is provided on the left side of the fender 13, which lowers the harvesting device 4 from a stowed position to a working position and raises it from a working position to a stowed position. A speed control lever 15 is provided on the right side of the fender 13, which operates an inverter device 35 that increases or decreases the output rotation of the electric motor 30. The operating angle of the lifting lever 14 is detected by an angle sensor 14S, such as a potentiometer, located at the bottom of the lifting lever 14.

[0024] The rear of the mowing device 4 and the front of the grass collection container 7 are connected by a chute 16 that extends in the front-to-back direction, and a blower 17 is provided in the middle of the chute 16 in the front-to-back direction to exhaust air into the chute 16.

[0025] A pair of link arms 18 are provided on the front of the left and right walls of the grass collection container 7. The front of each link arm 18 is pivotably fixed to the safety frame 6, and the safety frame 6 and the link arms 18 are connected by a lifting component 19 such as a hydraulic cylinder. The rear of the lower wall of the grass collection container 7 is resting on the horizontal frame 21A of the support frame 21, which will be described later. This allows the lifting component 19 to be driven to raise and lower the grass collection container 7.

[0026] As shown in Figures 2 and 3, the front motor room 8A of the motor room 8 is equipped with motors 30 and 40, and the rear motor room 8B is equipped with a battery 60 for storing power supplied to motors 30 and the like.

[0027] In a plan view, the electric motor 30 is located to the left of the left-right centerline of the aircraft frame 1, and the electric motor 40 is located to the right of the left-right centerline of the aircraft frame 1. This allows for... By suppressing the weight difference applied to both sides of the aircraft frame 1 in the left-right direction, steering performance can be improved.

[0028] In a side view, a support frame 20 extending upward from the aircraft frame 1 is provided in the partition between the front motor compartment 8A and the rear motor compartment 8B, and a support frame 21 extending upward from the aircraft frame 1 is provided at the rear end of the rear motor compartment 8B.

[0029] The support frame 20 is formed by a left vertical frame 20L extending upward from the middle left portion of the aircraft frame 1, a right vertical frame 20R extending upward from the middle right portion of the aircraft frame 1, and a horizontal frame 20A extending in the left-right direction that connects the upper parts of the left vertical frame 20L and the right vertical frame 20R.

[0030] The support frame 21 is formed by a left longitudinal frame 21L extending upward from the left rear end of the aircraft frame 1, a right longitudinal frame 21R extending upward from the right rear end of the aircraft frame 1, a transverse frame 21A extending in the left-right direction and connecting the upper parts of the left longitudinal frame 21L and the right longitudinal frame 21R, and a transverse frame 21B extending in the left-right direction and connecting the intermediate parts of the left longitudinal frame 21L and the right longitudinal frame 21R. The left part of the transverse frame 21B extends to the left of the left longitudinal frame 21L, and the right part extends to the right of the right longitudinal frame 21R.

[0031] The middle section of the left vertical frame 20L and the left end of the horizontal frame 21B are connected by the left front-rear frame 22L, which extends in the front-rear direction, and the middle section of the right vertical frame 20R and the right end of the horizontal frame 21B are connected by the right front-rear frame 22R, which extends in the front-rear direction. This allows the rear of the battery 60 to be positioned above the drive shaft 44 of the rear wheel 3, preventing large deformations from occurring in the aircraft frame 1.

[0032] The upper part of the left vertical frame 20L and the middle part of the left vertical frame 23L located at the rear of the control unit 5 are connected by a left front-rear frame 24L that extends in the front-rear direction, and the upper part of the right vertical frame 20R of the support frame 20 and the middle part of the right vertical frame 23R located at the rear of the control unit 5 are connected by a right front-rear frame 24R that extends in the front-rear direction.

[0033] As shown in Figures 4 and 5, the motor 30 and motor 40 are in front of the motor 30 and motor 40. It is connected to a gear case 50 located on the side. The output rotation of the electric motor 30 is accelerated and decelerated within the gear case 50 before being transmitted to the output shaft 31 to which the harvesting work device 4 etc. is connected, the output shaft 32 to which the blower 17 etc. is connected, and the output shaft 33 to which the hydraulic pump 51 etc. is connected. The output rotation of the electric motor 40 is accelerated and decelerated within the gear case 50 before being transmitted to the output shaft 41 to which the front wheels 2 etc. are connected, and to the output shaft 42 to which auxiliary work equipment etc. is connected.

[0034] Output shaft 31 extends forward from the left middle of the gear case 50 in the front-rear direction, and the front of output shaft 31 is connected to the harvesting device 4. Output shaft 32 extends forward from the front of the gear case 50, and the front of output shaft 32 is connected to the blower 17. Output shaft 33 extends rearward from the rear of the gear case 50, and a hydraulic pump 51 is connected to the rear of output shaft 33. A valve 52 is also provided on the upper part of the gear case 50.

[0035] Output shafts 41 and 42 extend in the front-rear direction along the right side of the gear case 50. The output rotation of output shaft 41 is transmitted to drive shaft 43 via differential gear 54 located inside the gear case 50. An insertion hole 50A extending in the left-right direction is provided in the middle of the gear case 50 in the front-rear direction, through which drive shaft 43 is inserted. Output shaft 42 extends rearward from the rear of the gear case 50.

[0036] The length of the electric motor 30 in the front-to-back direction is longer than the length of the electric motor 40 in the front-to-back direction. This allows for smooth driving of the harvesting work device 4, which is constantly driven and subjected to a large load.

[0037] As shown in Figure 6, the hydraulic pump 51 is positioned below the electric motors 30 and 40. This prevents air from entering the hydraulic pump 51 and suppresses air lock. Furthermore, the flexible piping 53A connecting the hydraulic pump 51 and the valve 52 is routed between the electric motors 30 and 40. This allows for effective use of the space formed between the electric motors 30 and 40.

[0038] As shown in Figure 7, the oil supplied to valve 52 is then supplied via valve 52 to clutch 55, located upstream of the transmission path of output shaft 31 in the gear case 50, and to clutch 56, located upstream of the transmission path of output shaft 32. This allows valve 52 to be driven to connect and disconnect clutch 55 and clutch 56.

[0039] The oil supplied from clutches 55 and 56 to valve 52 is returned to the gear case 50 through a flexible pipe 53B and a circulation port 50B formed at the top of the gear case 50. This allows the amount of oil in the gear case 50 to be maintained at a predetermined level.

[0040] As shown in Figure 8, the output rotation of the electric motor 30 is transmitted to the input shaft 57A of the gear case 50, the output rotation of the input shaft 57A is accelerated or decelerated before being transmitted to the output shaft 33, and the output rotation of the output shaft 33 is transmitted to the hydraulic pump 51. This allows the electric motor 30 to be driven to drive the hydraulic pump 51. In addition, the output rotation of the input shaft 57A is accelerated or decelerated before being transmitted to the rotating shaft 58A.

[0041] The output rotation of the input shaft 57A is transmitted to the rotating shaft 58A, the output rotation of the rotating shaft 58A is transmitted to the rotating shaft 58B, and the output rotation of the rotating shaft 58B is transmitted to the output shaft 31 via the clutch 55. The output rotation of the output shaft 31 is transmitted to the harvesting device 4. This allows the electric motor 30 to be driven, which in turn drives the harvesting device 4.

[0042] The output rotation of the input shaft 57A is transmitted to the rotating shaft 58C, and the output rotation of the rotating shaft 58C is transmitted to the output shaft 32 via the clutch 56. The output rotation of the output shaft 32 is transmitted to the blower 17. This allows the electric motor 30 to be driven, which in turn drives the blower 17.

[0043] The output rotation of the electric motor 40 is transmitted to the input shaft 57B of the gear case 50, and the output rotation of the input shaft 57B is accelerated or decelerated before being transmitted to the output shafts 41 and 42.

[0044] The output rotation of the output shaft 41 is transmitted to the drive shaft 43 for the front wheels via the differential gear 54, and the output rotation of the drive shaft 43 is transmitted to the front wheels 2. This allows the electric motor 40 to be driven and the front wheels 2 to rotate.

[0045] The output rotation of the output shaft 42 is transmitted to the drive shaft 44 for the rear wheels via the clutch 47 and differential gear 59 for 4WD, and the output rotation of the drive shaft 44 is transmitted to the rear wheels 3. This allows the electric motor 40 to be driven and the rear wheels 3 to rotate.

[0046] As shown in Figure 9, the battery 60 is formed from four battery modules 60A. The upper parts of the four battery modules 60A are connected by a pair of left and right angle-shaped mounting frames 61 that extend in the front-to-back direction and are spaced apart in the left-to-right direction, and the lower parts are connected by a pair of left and right square pipe-shaped mounting frames 62 that extend in the front-to-back direction and are spaced apart in the left-to-right direction.

[0047] The front portion of the mounting frame 61 extends forward of the battery 60, and the rear portion extends backward of the battery 60. The mounting frame 62 extends from the front end to the rear end of the battery 60.

[0048] As shown in Figure 10, the front part of the mounting frame 61 is detachably fixed to the horizontal frame 20A of the support frame 20 by fastening members such as bolts, and the rear part is detachably fixed to the horizontal frame 21A of the support frame 21 by fastening members such as bolts.

[0049] The left mounting frame 62 is mounted on the left front / rear frame 22L, and the right mounting frame 62 is mounted on the right front / rear frame 22R.

[0050] The front and rear of the mounting frame 61 are formed with openings 61A through which a suspension hook can be inserted when replacing the battery 60. This allows the battery 60 to be easily attached to and detached from the support frame 20 and support frame 21, and the battery 60 to be easily replaced.

[0051] A radiator 65 for cooling the water used to cool the electric motor 30 and the like is provided on the outside of the left wall of the motor room 8, and a fan 66 for blowing outside air towards the motor room 8 is provided between the radiator 65 and the electric motor 30. In addition, a circular opening (not shown) is formed on the left wall of the motor room 8 in the area opposite the fan 66. This helps to suppress the temperature rise of the electric motor 30 and the like, and prevents the electric motor 30 and the like from malfunctioning.

[0052] An auxiliary battery 67 is provided on the outside of the right wall of the power room 8, opposite the radiator 65, to store power supplied to the monitor of the control unit 5. This helps to suppress the weight difference between the left and right sides of the work vehicle.

[0053] As shown in Figures 11 and 12, an inverter device 35 that drives the motor 30 is provided on the rear side of the motor 30 at a predetermined distance in the front-rear direction, and an inverter device 45 that drives the motor 40 is provided on the rear side of the motor 40 at a predetermined distance in the front-rear direction. Furthermore, the inverter devices 35 and 45 are provided on the front side of the battery 60 at a predetermined distance in the front-rear direction. This makes it easy to arrange the motors 30 and 40 and the inverter devices 35 and 45. In addition, the air blown from the fan 66 can pass through the gap between the motors 30 and 40 and the inverter devices 35 and 45, allowing for efficient cooling of the motors 30 and 40 and the inverter devices 35 and 45.

[0054] As shown in Figures 13 and 14, a power receiving port 70 for receiving power from a household power supply is provided on the upper rear side of the radiator 65.

[0055] An electrical unit 71 is located beneath the battery 60. The electrical unit 71 contains a charger that converts the power supplied to the power receiving port 70 from AC to DC and supplies it to the battery 60, and a converter that steps down the DC voltage supplied via the power distribution unit 73, etc., to the rated voltage of the auxiliary battery 67. The electrical unit 71 is detachably fixed to the underside of the left front and rear frame 22L and the right front and rear frame 22R.

[0056] A monitoring unit 72, which houses a monitoring device for monitoring the temperature and voltage of the battery 60, is provided on the front side of the battery 60. The monitoring unit 72 is detachably fixed to the upper part of the left front and rear frame 24L and the right front and rear frame 24R.

[0057] In a side view, it is preferable that the upper wall of the monitoring unit 72 be positioned below the mounting frame 61. This prevents the monitoring unit 72 from protruding above the mounting frame 61, allowing the height of the motor room 8 to be lower. As a result, the center of gravity of the grass collection container 7, which is located above the motor room 8, can be set at a lower position, allowing the work vehicle to run stably.

[0058] Below the monitoring unit 72, there is a power distribution unit 73 which houses terminal blocks for distributing the power supplied from the monitoring unit 72 to inverter devices 35 and 45, and converters of the electrical equipment unit 71, etc. The power distribution unit 73 is detachably fixed to the underside of the left front and rear frame 24L and the right front and rear frame 24R.

[0059] <Harvesting device according to the first embodiment> As shown in Figures 15 and 16, the mowing device 4 of the first embodiment is formed from a pair of left and right blades 80 for cutting grass, a mower deck 81 with an open lower section covering the blades 80, and support members 82 that extend in the front-rear direction at predetermined intervals in the left-right direction to support the mower deck 81. A vertically extending rotating shaft 88 provided at the center of the blades 80 is supported by the mower deck 81, and gauge wheels 83 are provided at the front of each support member 82.

[0060] An outlet (not shown) for discharging the cut grass to the outside is formed on the right wall of the mower deck 81, and the left blade 80L, located on the left side, is positioned in front of the right blade 80R, located on the right side. This allows the cut grass to be efficiently discharged to the outside through the outlet.

[0061] The aircraft frame 1 and the more deck 81 are connected via the left arm 84 and the right arm 85.

[0062] The left arm 84 is formed from a left rear arm 84A that extends forward from the left front of the aircraft frame 1, and a left front arm 84B that extends forward from the front of the left rear arm 84A to the left and then forward. The front parts of the left rear arm 84A and the left front arm 84B are rotatably fixed to the upper wall of the moor deck 81.

[0063] The right arm 85 is formed from a right rear arm 85A, which extends forward from the right front of the machine frame 1 and consists of a cylinder or the like that can extend and retract in the front-rear direction, and a right front arm 85B, which extends forward to the right from the front of the right rear arm 85A and then extends forward. The front parts of the right rear arm 85A and the right front arm 85B are rotatably fixed to the upper wall of the mower deck 81, and the length of the right rear arm 85A can be extended or retracted by driving an extension / retraction device 86 such as a valve.

[0064] If the work vehicle is turning to the right, the telescopic device 86 is driven to extend the right rear arm 85A forward, changing the mower deck 81 from a forward position to a right-turn position.

[0065] In this specification, the forward position of the mower deck 81 refers to the position shown in Figure 15 where the front edge of the front part of the mower deck 81 is perpendicular to the direction of travel of the work vehicle, and the left rotation axis 88L located at the center of the left blade 80L is in front of the right rotation axis 88R located at the center of the right blade 80R. The right-turn position of the mower deck 81 refers to the position shown in Figure 16 where the front edge of the front part of the mower deck 81 has a predetermined angle counterclockwise with respect to the direction of travel of the work vehicle, and the right rotation axis 88R of the right blade 80R approaches the left rotation axis 88L of the left blade 80L in the front-rear direction. A more preferable position is one where the left rotation axis 88L of the left blade 80L and the right rotation axis 88R of the right blade 80R are at the same position in the front-rear direction. The solid arrow in Figure 15 and the dashed arrow in Figure 16 illustrate the flow of turf grass passing between the left blade 80L and the right blade 80R when the work vehicle is turned to the right. Note that the rotation axis 88 is a collective term for the left rotation axis 88L and the right rotation axis 88R.

[0066] <Harvesting device according to the second embodiment> The description of the same components as those in the first embodiment of the mowing device 4 will be omitted. In the second embodiment of the mowing device 4, an outlet (not shown) for discharging the cut grass to the outside is formed on the left wall of the mower deck 81, and the right blade 80R, which is located on the right side, is positioned in front of the left blade 80L, which is located on the left side.

[0067] When the work vehicle is turning left, the telescopic device 86 is driven to shorten the right rear arm 85A to the rear, changing the mower deck 81 from a forward position to a left-turning position.

[0068] In this specification, the left-turning position of the mower deck 81 refers to a position in which the front edge of the front part of the mower deck 81 has a predetermined angle clockwise with respect to the direction of travel of the work vehicle, and the left rotation axis 88L of the left blade 80L approaches the right rotation axis 88R of the right blade 80R in the front-rear direction. A more preferable position is one in which the right rotation axis 88R of the right blade 80R and the left rotation axis 88L of the left blade 80L are at the same position in the front-rear direction.

[0069] <Controller connection diagram> As shown in Figure 17, the controller 90 of the work vehicle is composed of a processing unit 91 consisting of a CPU and the like, a storage unit 92 consisting of ROM, RAM, hard disk drive, flash memory and the like, a timer 93 for measuring processing time, and a communication unit 94 for data communication with the outside.

[0070] The processing unit 91 drives the telescopic device 86 according to the operating angle of the steering wheel 10 to change the attitude of the mower deck 81, etc.

[0071] The memory unit 92 stores pre-set required time and other information, the timer 93 measures the processing time, and the communication unit 94 transmits and receives data with a portable controller (not shown).

[0072] The input side of the controller 90 is connected via a predetermined input interface circuit to an angle sensor 10S that detects the operating angle of the steering wheel 10, an angle sensor 14S that detects the operating angle of the lifting lever 14, an operating switch 52S provided on the control unit 5 that operates a valve 52 for engaging and disengaging the clutch 55, and a turning sensor 81S that detects when the moor deck 81 changes from a forward position to a turning position.

[0073] The output side of the controller 90 is connected via a predetermined output interface circuit to an extension / retraction device 86 that extends or retracts the length of the right rear arm 85A and a buzzer 87 that alerts the operator to an alarm.

[0074] <Work vehicle equipped with the harvesting device of the first embodiment> As shown in Figure 18, in step S1, the processing unit 91 of the controller 90 determines whether the harvesting device 4 is in the working position. If it is determined from the measurement value of the angle sensor 14S, which detects the operating angle of the lifting lever 14, that the system proceeds to step S2, and if it is determined that the harvesting device 4 is in the retracted position, that the system proceeds to step S9. This suppresses unnecessary driving and allows for efficient use of the output rotation of the electric motor 30.

[0075] In step S2, the processing unit 91 determines whether the left blade 80L and the right blade 80R are rotating. If it determines that the clutch 55 is engaged because the operating switch 52S, which operates the clutch 55 located between the rotating shaft 58B to which the output rotation of the electric motor 30 is transmitted and the transmission path of the harvesting work device 4, is pressed, the process proceeds to step S3. If it determines that the clutch 55 is disengaged because the operating switch 52S is not pressed, the process proceeds to step S9. This suppresses unnecessary driving and allows for efficient use of the output rotation of the electric motor 30.

[0076] In step S3, the processing unit 91 determines whether the work vehicle equipped with the harvesting device 4 of the first embodiment is turning to the right. If it is determined from the measurement value of the angle sensor 10S that detects the operating angle of the steering wheel 10 that the work vehicle is turning to the right, the process proceeds to step S4. If it is determined that the work vehicle is moving forward or turning to the left, the process proceeds to step S9.

[0077] In step S4, the processing unit 91 operates the telescopic device 86 to extend the length of the right rear arm 85A, thereby extending the right rear arm 85A forward and changing the mower deck 81 from a forward position to a right-turning position, and proceeding to step S5. As a result, the right rotation axis 88R of the right blade 80R approaches the left rotation axis 88L of the left blade 80L in the front-rear direction, and the grass passing between the left blade 80L and the right blade 80R is cut by the right blade 80R, thereby suppressing the leaving of uncut grass.

[0078] In step S5, the processing unit 91 determines whether the elapsed time since changing the mower deck 81 to a right-turn position has exceeded a predetermined time. If it determines from the measurement value of the timer 93 that measures processing time that the elapsed time since changing the mower deck 81 to a right-turn position has exceeded the predetermined time, the process proceeds to step S6. If it determines that the elapsed time since changing the mower deck 81 to a right-turn position has been within the predetermined time, the process returns to step S4.

[0079] In step S6, the processing unit 91 activates the buzzer 87 to sound an alarm, prompting the operator to operate the steering wheel 10 to complete the right turn of the work vehicle and move forward, before proceeding to step S7. This prevents operator errors and shortens the harvesting time.

[0080] In step S7, the processing unit 91 determines whether the work vehicle equipped with the harvesting device 4 of the first embodiment is turning to the right. If it is determined from the measurement value of the angle sensor 10S that the work vehicle is turning to the right, the process returns to step S6. If it is determined that the work vehicle is moving forward or turning to the left, the process proceeds to step S8.

[0081] In step S8, the processing unit 91 stops the buzzer 87 and terminates.

[0082] In step S9, the processing unit 91 stops the telescopic device 86 that extends or retracts the length of the right rear arm 85A, maintaining the forward position of the mower deck 81 and ending the process.

[0083] <Work vehicle equipped with the harvesting device of the second embodiment> As shown in Figure 19, in step S11, the processing unit 91 of the controller 90 determines whether the harvesting device 4 is in the working position. If it is determined from the measurement value of the angle sensor 14S, which detects the operating angle of the lifting lever 14, that the system is in the working position, the system proceeds to step S12. If it is determined that the harvesting device 4 is in the retracted position, the system proceeds to step S19. This suppresses unnecessary driving and allows for efficient use of the output rotation of the electric motor 30.

[0084] In step S12, the processing unit 91 determines whether the left blade 80L and the right blade 80R are rotating. If it determines that the clutch 55, which is located between the rotating shaft 58B to which the output rotation of the electric motor 30 is transmitted and the transmission path of the harvesting work device 4, is pressed and the clutch 55 is engaged, the process proceeds to step S13. If it determines that the clutch 55 is disengaged and the operation switch 52S is not pressed, the process proceeds to step S19. This suppresses unnecessary driving and allows for efficient use of the output rotation of the electric motor 30.

[0085] In step S13, the processing unit 91 determines whether the work vehicle equipped with the harvesting device 4 of the second embodiment is turning left. If it determines from the measurement value of the angle sensor 10S that detects the operating angle of the steering wheel 10 that the work vehicle is turning left, the process proceeds to step S14. If it determines that the work vehicle is moving forward or turning right, the process proceeds to step S19.

[0086] In step S14, the processing unit 91 operates the telescopic device 86 to extend or retract the length of the right rear arm 85A, shortening the right rear arm 85A to the rear and changing the mower deck 81 from a forward position to a left-turning position, and proceeding to step S15. As a result, the left rotation axis 88L of the left blade 80L approaches the right rotation axis 88R of the right blade 80R in the front-rear direction, and the grass passing between the left blade 80L and the right blade 80R is cut by the left blade 80L, thereby suppressing the leaving of uncut grass.

[0087] In step S15, the processing unit 91 determines whether the elapsed time since changing the mower deck 81 to a left-turn position has exceeded a predetermined time. If it determines from the measurement value of the timer 93 that measures processing time that the elapsed time since changing the mower deck 81 to a left-turn position has exceeded the predetermined time, the process proceeds to step S16. If it determines that the elapsed time since changing the mower deck 81 to a left-turn position has been within the predetermined time, the process returns to step S14.

[0088] In step S16, the processing unit 91 activates the buzzer 87 to sound an alarm, prompting the operator to operate the steering wheel 10 to complete the left turn of the work vehicle and move forward, before proceeding to step S17. This prevents operator errors and shortens the harvesting time.

[0089] In step S17, the processing unit 91 determines whether the work vehicle equipped with the harvesting device 4 of the first embodiment is turning left. If it is determined from the measurement value of the angle sensor 10S that the work vehicle is turning left, the process returns to step S16. If it is determined that the work vehicle is moving forward or turning right, the process proceeds to step S18.

[0090] In step S18, the processing unit 91 stops the buzzer 87 and terminates.

[0091] In step S19, the processing unit 91 stops the telescopic device 86 that extends and retracts the length of the right rear arm 85A, maintaining the forward position of the mower deck 81 and ending the process. [Explanation of symbols]

[0092] 1. Aircraft frame 2 Front wheels 3 Rear wheels 4 Reaping device 5. Control Unit 80L Left Blade 80R Right Blade 81 More Deck 84 Left Arm 85 Right Arm 88L Left-hand rotation axis 88R Right-hand rotation axis

Claims

1. In a work vehicle having a frame (1) with a pair of front wheels (2) and rear wheels (3) on the underside, a grass cutting device (4) for cutting grass on the front side of the frame (1), and a control unit (5) for the operator to sit on on the rear side of the grass cutting device (4), The aforementioned mowing device (4) is formed by a mower deck (81) and a left blade (80L) and a right blade (80R) that are rotatably supported on the mower deck (81) for cutting grass. The aircraft frame (1) and the moor deck (81) are connected by a left arm (84) formed to a predetermined length in the front-rear direction and a right arm (85) whose length in the front-rear direction is extendable and retractable. In the front-to-back direction, the left rotation axis (88L) of the left blade (80L) is positioned forward of the right rotation axis (88R) of the right blade (80R). A work vehicle characterized in that, when the work vehicle is turned to the right, the right arm (85) is extended forward and the mower deck (81) is rotated counterclockwise, bringing the right rotation axis (88R) closer to the left rotation axis (88L) in the front-rear direction.

2. In a work vehicle having a frame (1) with a pair of front wheels (2) and rear wheels (3) on the underside, a grass cutting device (4) for cutting grass on the front side of the frame (1), and a control unit (5) for the operator to sit on on the rear side of the grass cutting device (4), The aforementioned mowing device (4) is formed by a mower deck (81) and a left blade (80L) and a right blade (80R) that are rotatably supported on the mower deck (81) for cutting grass. The aircraft frame (1) and the moor deck (81) are connected by a left arm (84) formed to a predetermined length in the front-rear direction and a right arm (85) whose length in the front-rear direction is extendable and retractable. In the front-to-back direction, the right rotation axis (88R) of the right blade (80R) is positioned forward of the left rotation axis (88L) of the left blade (80L). A work vehicle characterized in that, when the work vehicle is turned to the left, the right arm (85) is shortened to the rear and the mower deck (81) is rotated clockwise, bringing the left rotation axis (88L) closer to the right rotation axis (88R) in the front-rear direction.

3. The work vehicle according to claim 1 or 2, wherein the extension and retraction of the right arm (85) is stopped when the rotation of the left blade (80L) and the right blade (80R) is stopped.

4. The work vehicle according to claim 1 or 2, wherein the extension and retraction of the right arm (85) is stopped when the harvesting device (4) is raised from a working position to a retraction position.

5. The work vehicle according to claim 1, wherein a buzzer (87) provided on the control unit (5) sounds when the mower deck (81) has been rotated counterclockwise for a predetermined time.

6. The work vehicle according to claim 2, wherein when the mower deck (81) is rotated clockwise and a predetermined time has elapsed in that state, a buzzer (87) provided on the control unit (5) sounds.

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