Work vehicles

Abstract

The present invention provides a work vehicle that can suppress power consumption by controlling the output rotation of the electric motor within a predetermined range by placing a hydraulic pump downstream of the electric motor's power transmission path. [Solution] A first electric motor (30) that drives the work device (4) and a second electric motor (40) that drives the front wheels (2) are provided on the lower side of the grass collection container (7). A hydraulic pump (51) that supplies oil to the hydraulic equipment (19) mounted on the work vehicle is placed between the first electric motor (30) and the transmission path of the work device (4). The controller (80) of the work vehicle increases or decreases the output rotation of the first electric motor (30) in accordance with the driving of the hydraulic equipment (19).

Description

Technical Field

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

Background Art

[0002] Conventionally, there is known a work vehicle including a work electric motor for driving a work device for mowing turf grass provided on the front side of a machine body frame, and a traveling electric motor for driving front wheels or the like. (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, with the means of Patent Document 1, there is a problem that large hydraulic equipment cannot be used because a hydraulic pump is not mounted.

[0005] Therefore, the present invention provides a work vehicle in which a hydraulic pump is arranged on the downstream side of the transmission path of a work electric motor, and the output rotation of the work electric motor is controlled within a predetermined range to suppress power consumption.

Means for Solving the Problems

[0006] The present invention that solves the above problems is as follows. That is, in the invention according to claim 1, a pair of left and right front wheels (2) and rear wheels (3) are provided below a machine body frame (1), a work device (4) for mowing turf grass is provided on the front side of the machine body frame (1), a control unit (5) on which an operator boards is provided on the rear side of the work device (4), and a grass collecting container (7) for accommodating turf grass is provided on the rear side of the control unit (5). The work vehicle is characterized in that a first electric motor (30) for driving the work device (4) and a second electric motor (40) for driving the front wheels (2) are provided below the grass collection container (7), a hydraulic pump (51) for supplying oil to hydraulic equipment (19) mounted on the work vehicle is placed between the first electric motor (30) and the transmission path of the work device (4), and the controller (80) of the work vehicle increases or decreases the output rotation of the first electric motor (30) in accordance with the driving of the hydraulic equipment (19).

[0007] The invention described in claim 2 is a work vehicle according to claim 1, wherein the controller increases or decreases the output rotation of the first electric motor (30) to a first rotational speed (R1) when the drive of the work device (4) and hydraulic equipment (19) is stopped, and increases or decreases the output rotation of the first electric motor (30) to a second rotational speed (R3) which is faster than the first rotational speed (R1) when the drive of the hydraulic pump (51) is stopped and the work device (4) is being driven.

[0008] The invention described in claim 3 is a work vehicle according to claim 2, wherein when the controller drives the hydraulic pump (51) to supply oil to the hydraulic equipment (19) that raises and lowers the work device (4) and the grass collection container (7), the output rotation of the first electric motor (30) is increased or decreased to a third rotation speed (R4) which is faster than the first rotation speed (R1).

[0009] The invention described in claim 4 is a work vehicle according to claim 3, wherein the controller drives the hydraulic pump (51) to increase or decrease the output rotation of the first electric motor (30) to a fourth rotation speed (R2) which is faster than the first rotation speed (R1) when the steering wheel (10) of the control unit (5) is operated.

[0010] The invention described in claim 5 is a work vehicle according to claim 4, wherein the second rotational speed (R3) and the third rotational speed (R4) are set to a higher speed than the fourth rotational speed (R2), and the third rotational speed (R4) is set to the same speed as or higher than the second rotational speed (R3). [Effects of the Invention]

[0011] According to the invention described in claim 1, a first electric motor (30) for driving a work device (4) and a second electric motor (40) for driving the front wheels (2) are provided below the grass collection container (7), a hydraulic pump (51) for supplying oil to hydraulic equipment (19) mounted on the work vehicle is placed between the first electric motor (30) and the transmission path of the work device (4), and the controller (80) of the work vehicle increases or decreases the output rotation of the first electric motor (30) in accordance with the driving of the hydraulic equipment (19), so that the output rotation of the first electric motor (30) can be controlled within a predetermined range and power consumption can be suppressed.

[0012] According to the invention described in claim 2, in addition to the effects of the invention described in claim 1, when the drive of the work device (4) and the hydraulic equipment (19) is stopped, the controller increases or decreases the output rotation of the first electric motor (30) to the first rotational speed (R1), and when the drive of the hydraulic pump (51) is stopped and the work device (4) is being driven, the controller increases or decreases the output rotation of the first electric motor (30) to the second rotational speed (R3), which is faster than the first rotational speed (R1), so that the hydraulic equipment (19) is not driven, and thus power consumption can be suppressed when the drive of the hydraulic equipment (19) is stopped.

[0013] According to the invention described in claim 3, in addition to the effects of the invention described in claim 2, when the controller drives the hydraulic pump (51) to supply oil to the hydraulic equipment (19) that raises and lowers the work device (4) and the grass collection container (7), it increases or decreases the output rotation of the first electric motor (30) to a third rotation speed (R4) which is faster than the first rotation speed (R1). Therefore, when the hydraulic equipment (19) is being driven, an appropriate amount of oil can be supplied from the hydraulic pump (51) to the hydraulic equipment (19).

[0014] According to the invention described in claim 4, in addition to the effects of the invention described in claim 3, when the controller drives the hydraulic pump (51) and the steering wheel (10) of the operation unit (5) is being operated, the output rotation of the first electric motor (30) is increased or decreased to a fourth rotational speed (R2) higher than the first rotational speed (R1). Therefore, when the steering wheel (10) is being operated, an appropriate amount of oil can be supplied from the hydraulic pump (51) to the steering device.

[0015] According to the invention described in claim 5, in addition to the effects of the invention described in claim 4, the second rotational speed (R3) and the third rotational speed (R4) are set higher than the fourth rotational speed (R2), and the third rotational speed (R4) is set to be the same speed as or higher than the second rotational speed (R3). Therefore, the output rotation of the first electric motor (30) can be controlled within a predetermined range to further suppress power consumption.

Brief Description of the Drawings

[0016] [Figure 1] It is a perspective view of the work vehicle viewed from the front left side. [Figure 2] It is a plan view of the operation panel. [Figure 3] It is a perspective view of the main part of the steering column. [Figure 4] It is a perspective view of the lift lever of the working device and the like. [Figure 5] It is an explanatory diagram of the main part of the hydraulic circuit. [Figure 6] It is a perspective view of the front part of the electric motor room viewed from the rear left side. [Figure 7] It is a perspective view of the rear part of the electric motor room viewed from the rear left side. [Figure 8] It is a perspective view of the electric motor and the gear case viewed from the front left side. [Figure 9] It is a perspective view of the electric motor and the gear case viewed from the rear left side. [Figure 10] It is a rear view of the electric motor and the gear case. [Figure 11] It is a sectional view of the broken part of the left part of the gear case. [Figure 12] It is a transmission diagram of the output rotation of the electric motor. [Figure 13] It is a perspective view of the battery seen from the rear left side. [Figure 14] It is a plan view of the battery mounted on the electric motor room. [Figure 15] It is a plan view of the electric motor and the inverter device. [Figure 16] It is a left side view of the electric motor and the inverter device. [Figure 17] It is a left side view of the electric motor room. [Figure 18] It is a perspective view of the electric motor room seen from the rear right side. [Figure 19] It is a connection diagram of the controller. [Figure 20] It is a flowchart of the increase and decrease of the output rotation of the electric motor. [Figure 21] It is an explanatory diagram of the output rotation of the electric motor.

Mode for Carrying Out the Invention

[0017] As shown in FIG. 1, the work vehicle is provided with a pair of left and right front wheels 2 at the front lower part of the body frame 1, and a pair of left and right rear wheels 3 at the rear lower part of the body frame 1.

[0018] At the front part of the body frame 1, a working device 4 for mowing the turf growing in the field is provided, and at the rear side of the working device 4, a control unit 5 on which an operator rides is provided. Further, at the rear side of the control unit 5, a safety frame (ROPS) 6 for protecting the operator is provided, at the rear side of the safety frame 6, a grass collecting container 7 for storing the mowed turf is provided, and at the lower side of the grass collecting container 7, an electric motor room 8 for arranging a working electric motor 30, a battery 60, etc. for driving the working device 4 is provided.

[0019] In front of the driver's seat of the control unit 5, a steering column 11 for supporting a steering wheel 10 is provided. An operation panel 12 is provided at the upper part of the steering column 11, and the lower part is fixed to the front part of the floor.

[0020] A brake pedal 13A for reducing the rotational speed of the front wheels 2 is located on the left side of the steering column 11, and an accelerator pedal 13B for increasing or decreasing the output rotational speed of the electric motor 40 that drives the front wheels 2 is located on the right side. The area above the front wheels 2 is covered by a fender 14.

[0021] The rear of the work 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 for exhausting air into the chute 16 is provided in the middle of the chute 16 in the front-to-back direction.

[0022] A pair of left and right link arms 18 are provided at the front of the left and right walls of the grass collection container 7. The front of the link arms 18 are fixed to the safety frame 6 so as to be able to swing from side to side, and the safety frame 6 and the link arms 18 are connected by a hydraulic cylinder 19. 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.

[0023] As shown in Figure 2, a monitor 12A that displays the output rotation speed of the electric motor 30 is provided in the center of the control panel 12, a rotation switch 12B that rotates the blade housed in the work device 4 is provided on the right rear of the control panel 12, and a start switch 12C that drives the hydraulic pump 51 (described later) to excite the solenoid valve 25A located between the hydraulic circuit of the hydraulic pump 51 and the hydraulic cylinder 19B is provided to the right of the monitor 12A.

[0024] As shown in Figure 3, the operating angle of the steering wheel 10 is measured by an angle sensor 10C that detects the rotation angle of a disc-shaped detection body 10B fitted onto a support shaft 10A that supports the steering wheel 10.

[0025] As shown in Figures 4 and 5, a lifting lever 15A for raising and lowering the work device 4 is provided at the front of the fender 14 located to the right of the cockpit. A lifting lever 15B for raising and lowering the grass collection container 7 is provided to the rear left of the lifting lever 15A, and a tilt lever 15C for moving the grass collection container 7 to a downward-sloping position is provided to the rear right.

[0026] When the lifting lever 15A is moved to the rear, oil is supplied to the hydraulic cylinder 19A via the solenoid valve 25A, shortening the rod of the hydraulic cylinder 19A and raising the work device 4 to the retracted position. When it is moved to the front, the rod extends and the work device 4 lowers to the working position. The movement of the lifting lever 15A is detected by a proximity sensor (not shown) provided at the base of the lifting lever 15A.

[0027] When the lifting lever 15B is moved to the rear, oil is supplied to the hydraulic cylinder 19B via the solenoid valve 25B, shortening the rod of the hydraulic cylinder 19B and raising the grass collection container 7 to the discharge position. When it is moved to the front, the rod extends and the grass collection container 7 is placed on the horizontal frame 21A. The movement of the lifting lever 15B is detected by a proximity sensor (not shown) provided at the base of the lifting lever 15B.

[0028] When the tilt lever 15C is moved to the rear, oil is supplied to the hydraulic cylinder 19C via the solenoid valve 25C, shortening the rod of the hydraulic cylinder 19C and tilting the grass collection container 7 downwards. When it is moved to the front, the rod extends and makes the grass collection container 7 horizontal. The movement of the tilt lever 15C is detected by a proximity sensor (not shown) provided at the base of the tilt lever 15C. In this specification, the hydraulic cylinders 19A to 19C are collectively referred to as the hydraulic cylinder ("hydraulic equipment" in the claims) 19.

[0029] As shown in Figures 6 and 7, the front motor compartment 8A of the motor compartment 8 is provided with an electric motor (the "first motor" in the claim) 30 and an electric motor (the "second motor" in the claim) 40, and the rear motor compartment 8B is provided with a battery 60 for storing power supplied to the electric motors 30 and the like.

[0030] 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 between the weight applied to the left of the aircraft frame 1's lateral centerline and the weight applied to the right of the aircraft frame 1's lateral centerline, steering performance can be improved.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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 46 of the rear wheel 3, preventing large deformations from occurring in the aircraft frame 1.

[0035] 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.

[0036] As shown in Figures 8 and 9, 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 working 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 working equipment etc. is connected. In this technical field, the output shaft is often referred to as a PTO.

[0037] Output shaft 31 extends forward from the left middle of the gear case 50 in the front-rear direction, and the front end of output shaft 31 is connected to the work device 4. Output shaft 32 extends forward from the front of the gear case 50, and the front end of output shaft 32 is connected to the blower 17. Output shaft 33 extends rearward from the rear of the gear case 50, and the rear end of output shaft 33 is connected to the hydraulic pump 51. A valve 52 is also provided on the upper part of the gear case 50.

[0038] 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.

[0039] 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 work device 4, which is constantly driven and subjected to a large load.

[0040] As shown in Figure 10, 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.

[0041] As shown in Figure 11, 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.

[0042] 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.

[0043] As shown in Figure 12, the output rotation of the electric motor 30 is transmitted to the input shaft 57A of the gear case 50, and the output rotation of the input shaft 57A is transmitted to the rotating shaft 58A after being increased or decreased in speed.

[0044] The output rotation of the rotating shaft 58A 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, which in turn drives the hydraulic pump 51.

[0045] The output rotation of the rotating shaft 58A is accelerated or decelerated before being 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 work device 4. This allows the electric motor 30 to be driven, which in turn drives the work device 4.

[0046] The output rotation of the rotating shaft 58A is accelerated or decelerated before being 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.

[0047] 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.

[0048] 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. In addition, the output rotation of the output shaft 42 can also be transmitted to the rear wheels 3 via a clutch, auxiliary work equipment, or the differential gear.

[0049] As shown in Figure 13, 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.

[0050] 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.

[0051] As shown in Figure 14, 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] As shown in Figures 15 and 16, 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.

[0057] As shown in Figures 17 and 18, a power receiving port 70 for receiving power from a household power supply is provided on the upper rear side of the radiator 65.

[0058] Below the battery 60 is an electrical unit 71 which houses 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.

[0059] 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 side of the left front and rear frame 24L and the right front and rear frame 24R.

[0060] 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.

[0061] 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.

[0062] As shown in Figure 19, the controller 80 of the work vehicle is formed from a processing unit 81 consisting of a CPU and the like, a storage unit 82 consisting of ROM, RAM, a hard disk drive, flash memory and the like, and a communication unit 83 for data communication with the outside.

[0063] The processing unit 81 increases or decreases the output rotation of the electric motor 30 according to the operating angle of the steering wheel 10.

[0064] The memory unit 82 stores the output rotation of the electric motor 30 and other settings that have been set in advance, and the communication unit 83 transmits and receives data with a portable controller (not shown).

[0065] On the input side of the controller 80, an angle sensor 10C for detecting the operating angle of the steering wheel 10, a rotation switch 12B for rotating the blade of the work device 4, a start switch 12C for driving the hydraulic pump 51, a lifting lever 15A for raising and lowering the work device 4 via a hydraulic cylinder 19A, a lifting lever 15B for raising and lowering the grass collection container 7 via a hydraulic cylinder 19B, and a tilt lever 15C for changing the posture of the grass collection container 7 via a hydraulic cylinder 19C are connected via a predetermined input interface circuit.

[0066] An inverter device 35 for driving the electric motor 30 is connected to the output side of the controller 80 via a predetermined output interface circuit.

[0067] As shown in Figure 20, in step S1, the processing unit 81 of the controller 80 determines whether the hydraulic pump 51 that supplies oil to the hydraulic cylinder 19A, etc., is running. If the start switch 12C that starts the hydraulic pump 51 is not pressed, the process proceeds to step S2; if the start switch 12C is pressed, the process proceeds to step S3.

[0068] In step S2, the processing unit 81 operates the inverter device 35 to maintain the output rotation of the electric motor 30 at a rotational speed (the "first rotational speed" in the claim) R1 [rps], and then returns to step S1.

[0069] In step S3, the processing unit 81 determines whether the steering wheel 10 is being operated. If the measurement value of the angle sensor 10C, which detects the operating angle of the steering wheel 10, is increasing or decreasing, that is, if the operator is operating the steering wheel 10, the process proceeds to step S4. If the measurement value of the angle sensor 10C is not increasing or decreasing, that is, if the operator is not operating the steering wheel 10, the process proceeds to step S5.

[0070] In step S4, the processing unit 81 operates the inverter device 35 to increase the output rotation of the electric motor 30 to the rotational speed (the "fourth rotational speed" in the claim) R2 [rps], and then returns to step S1. As shown in Figure 21, the rotational speed R2 [rps] is set to be faster than the rotational speed R1 [rps].

[0071] In step S5, the processing unit 81 determines whether the blade housed in the work device 4 is rotating. If the rotation switch 12B for rotating the blade is pressed, the process proceeds to step S6; otherwise, the process proceeds to step S7.

[0072] In step S6, the processing unit 81 operates the inverter device 35 to increase the output rotation of the electric motor 30 to the rotational speed (the "second rotational speed" in the claim) R3 [rps], and then returns to step S1. As shown in Figure 21, the rotational speed R3 [rps] is set to be faster than the rotational speed R2 [rps].

[0073] In step S7, the processing unit 81 determines whether the work device 4 or the grass collection container 7 is raised or lowered, or whether the grass collection container 7 is tilted. If the lifting lever 15A for raising or lowering the work device 4, the lifting lever 15B for raising or lowering the grass collection container 7, or the tilting lever 15C for changing the posture of the grass collection container 7 is being operated, the process proceeds to step S8. If the lifting lever 15A, the lifting lever 15B, or the tilting lever 15C are not being operated, the process ends.

[0074] In step S8, the processing unit 81 operates the inverter device 35 to increase the output rotation of the electric motor 30 to the rotational speed (the "third rotational speed" in the claim) R4 [rps], and then returns to step S1. As shown in Figure 21, the rotational speed R4 [rps] is set to be the same speed as or higher than the rotational speed R3 [rps].

[0075] When only the lifting lever 15A is operated, the rotational speed R4 [rps] of the output rotation of the electric motor 30 is set to the same speed as rotational speed R3 [rps]. When the lifting lever 15A and the lifting lever 15B or the tilting lever 15C are operated simultaneously, the rotational speed R4 [rps] of the output rotation of the electric motor 30 is set to a speed higher than rotational speed R3 [rps]. [Explanation of symbols]

[0076] 1. Aircraft frame 2 Front wheels 3 Rear wheels 4. Working equipment 5. Control Unit 7 Grass collection container 19. Hydraulic Cylinder (Hydraulic Equipment) 30 Electric motor (1st electric motor) 40 Electric motor (second electric motor) 51 Hydraulic pump 80 Controllers R1 rotation speed (first rotation speed) R2 rotation speed (4th rotation speed) R3 rotation speed (2nd rotation speed) R4 rotation speed (3rd rotation speed)

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) on the front of the frame (1), a pilot unit (5) on the rear of the pilot unit (4) where an operator sits, and a grass collection container (7) on the rear of the pilot unit (5), Below the grass collection container (7), a first electric motor (30) for driving the work device (4) and a second electric motor (40) for driving the front wheels (2) are provided. A hydraulic pump (51) for supplying oil to the hydraulic equipment (19) mounted on the work vehicle is placed between the transmission path of the first electric motor (30) and the work device (4). The controller (80) of the work vehicle is characterized in that it increases or decreases the output rotation of the first electric motor (30) in accordance with the drive of the hydraulic equipment (19).

2. The work vehicle according to claim 1, wherein the controller increases or decreases the output rotation of the first electric motor (30) to a first rotational speed (R1) when the drive of the work device (4) and the hydraulic equipment (19) is stopped, and increases or decreases the output rotation of the first electric motor (30) to a second rotational speed (R3) which is faster than the first rotational speed (R1) when the drive of the hydraulic pump (51) is stopped and the work device (4) is being driven.

3. The work vehicle according to claim 2, wherein when the controller drives the hydraulic pump (51) to supply oil to the hydraulic equipment (19) that raises and lowers the work device (4) and the grass collection container (7), the output rotation of the first electric motor (30) is increased or decreased to a third rotation speed (R4) which is faster than the first rotation speed (R1).

4. The work vehicle according to claim 3, wherein the controller drives the hydraulic pump (51) and, when the steering wheel (10) of the control unit (5) is operated, increases or decreases the output rotation of the first electric motor (30) to a fourth rotation speed (R2) which is faster than the first rotation speed (R1).

5. The work vehicle according to claim 4, wherein the second rotational speed (R3) and the third rotational speed (R4) are set to a higher speed than the fourth rotational speed (R2), and the third rotational speed (R4) is set to the same speed as or higher than the second rotational speed (R3).

Images