Work vehicle

Abstract

To provide a work vehicle capable of calculating the electric power of a battery consumed by a working electric motor and a traveling electric motor, and predicting a working time available for reaping work.SOLUTION: A first electric motor 30 that drives a working device 4, a second electric motor 40 that drives front wheels 2, and a battery 50 that supplies electric power to the first electric motor 30 and the second electric motor 40 are provided at a rear lower side of an operating unit 5. A mode switch 15 is provided on the operating unit 5, and for each mode selected by the mode switch 15, driving conditions of the first electric motor 30 and the second electric motor 40 are preset. When a mode is selected by the mode switch 15, the output rotation of the first electric motor 30 is not accelerated or decelerated by the output rotation of the second electric motor 40, and the first electric motor 30 is driven at preset power consumption.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a work vehicle for cutting lawn grass. [Background technology]

[0002] A known work vehicle has been known in which, behind and below the control unit, a drive motor that drives the rear wheels, a work motor that drives a work device that cuts grass, and a battery that supplies power to the drive motor and work motor, and which can drive the drive motor and work motor according to the settings for each mode selected by a mode switch on the control unit (Patent Document 1).

[0003] A known work vehicle has a grass-cutting implement mounted in front of the steering unit, and is provided below and behind the steering unit with a traveling motor that drives the rear wheels, a working motor that drives the grass-cutting implement, and a battery that supplies power to the traveling motor and the working motor (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-196354 [Patent Document 2] Japanese Patent Application Publication No. 2023-156640 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the technology of Patent Document 1, the output rotation of the driving motor is increased or decreased depending on the output rotation of the working motor, and therefore the battery power consumed by the working motor and the driving motor increases or decreases for each mode, making it difficult to predict the working time during which mowing work is possible.

[0006] Furthermore, with the technology of Patent Document 2, the mowing work is heavily dependent on the experience of the worker, making it difficult to predict the amount of battery power consumed by the working motor and the propulsion motor depending on the state of the grass planted, and making it difficult to predict the working time available for mowing work.

[0007] Therefore, the present invention provides a work vehicle that can calculate the battery power consumed by the work motor and the driving motor, and accurately predict the working time and driving time of the harvesting work. [Means for solving the problem]

[0008] The present invention, which has solved the above problems, is as follows. That is, the invention described in claim 1 is a work vehicle having a pair of left and right front wheels (2) and rear wheels (3) on the underside of a machine frame (1), a working device (4) for cutting grass on the front side of the machine frame (1), and a control section (5) on which an operator rides on the top side of the machine frame (1), The work vehicle is characterized in that a first electric motor (30) that drives the working device (4), a second electric motor (40) that drives the front wheels (2), and a battery (50) that supplies power to the first electric motor (30) and the second electric motor (40) are provided below and behind the steering unit (5), a mode switch (15) is provided in the steering unit (5), drive conditions of the first electric motor (30) and the second electric motor (40) are set in advance for each mode selected by the mode switch (15), and when a mode is selected by the mode switch (15), the output rotation of the first electric motor (30) is not increased or decreased by the output rotation of the second electric motor (40), and the first electric motor (30) is driven with a preset power consumption.

[0009] A second aspect of the present invention is the work vehicle of the first aspect, wherein the second electric motor (40) is driven at a preset maximum output rotation speed.

[0010] A third aspect of the present invention is the work vehicle according to the second aspect, wherein the maximum output rotation speed of the second electric motor (40) is set to be lower than the rated output rotation speed of the second electric motor (40).

[0011] A fourth aspect of the present invention is the work vehicle according to the second or third aspect, wherein the second electric motor (40) is driven at a preset angular acceleration.

[0012] The invention described in claim 5 is the work vehicle described in claim 1, wherein the operation section (5) is provided with a speed change lever (14) for increasing or decreasing the output rotation of the first electric motor (30) and an accelerator pedal (12) for increasing or decreasing the output rotation of the second electric motor (40), and when a mode is selected by the mode switch (15), the speed change lever (14) is regulated to increase or decrease the output rotation of the first electric motor (30) and the accelerator pedal (12) is regulated to increase or decrease the output rotation of the second electric motor (40). [Effects of the Invention]

[0013] According to the invention of claim 1, a first electric motor (30) for driving the working device (4), a second electric motor (40) for driving the front wheels (2), and a battery (50) for supplying power to the first electric motor (30) and the second electric motor (40) are provided below and behind the steering unit (5), a mode switch (15) is provided on the steering unit (5), and drive conditions of the first electric motor (30) and the second electric motor (40) are set in advance for each mode selected by the mode switch (15), and when a mode is selected by the mode switch (15), the output rotation of the first electric motor (30) is not increased or decreased by the output rotation of the second electric motor (40), and the first electric motor (30) is driven at a preset power consumption, so that the power of the battery (50) consumed by the first electric motor (30) can be calculated and the working time of the reaping work can be predicted with high accuracy.

[0014] According to the invention of claim 2, in addition to the effect of the invention of claim 1, the second electric motor (40) is driven at a preset maximum output rotation, and therefore, the power of the battery (50) consumed by the second electric motor (40) can be calculated, and the running time during which the harvesting work can be performed can be accurately predicted.

[0015] According to the invention of claim 3, in addition to the effect of the invention of claim 2, the maximum output rotation of the second electric motor (40) is set to a speed lower than the rated output rotation of the second electric motor (40). Therefore, even when a large load exceeding the rated torque is applied to the second electric motor (40), the maximum output rotation of the second electric motor (40) can be maintained.

[0016] According to the invention of claim 4, in addition to the effects of the invention of claim 2 or 3, the second electric motor (40) is driven at a preset angular acceleration, so that the output rotation speed of the second electric motor (40) can be quickly increased, and a quick response can be made to sudden rainfall.

[0017] According to the invention of claim 5, in addition to the effect of the invention of claim 1, the operating section (5) is provided with a speed change lever (14) for increasing or decreasing the output rotation of the first electric motor (30) and an accelerator pedal (12) for increasing or decreasing the output rotation of the second electric motor (40), and when a mode is selected by the mode switch (15), the speed change lever (14) regulates the increase or decrease of the output rotation of the first electric motor (30) and the accelerator pedal (12) regulates the increase or decrease of the output rotation of the second electric motor (40). Therefore, the power of the battery (50) consumed by the first electric motor (30) can be calculated, and the working time of the reaping work can be predicted with higher accuracy. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a perspective view of the work vehicle as seen from the front left side. [Figure 2] FIG. 2 is a perspective view of the front part of the motor chamber as viewed from the rear left side. [Figure 3] FIG. 2 is a perspective view of the rear of the motor compartment as viewed from the rear left side. [Figure 4] FIG. [Figure 5] FIG. 2 is a perspective view of the electric motor as seen from the rear left side. [Figure 6] FIG. [Figure 7] FIG. [Figure 8]FIG. 2 is a perspective view of the battery as seen from the rear left side. [Figure 9] FIG. 2 is a plan view of the motor compartment with the battery mounted therein. [Figure 10] FIG. 2 is a plan view of the electric motor and the inverter device. [Figure 11] FIG. 2 is a left side view of the electric motor and the inverter device. [Figure 12] 1 is a transmission diagram of the output rotation of an electric motor. [Figure 13] FIG. 2 is a connection diagram of a controller. [Figure 14] FIG. 2 is an explanatory diagram of modes 1 to 3 selected by the mode switch. [Figure 15] FIG. 2 is an explanatory diagram of a power circuit and output wiring. [Figure 16] 1 is an explanatory diagram of maximum output rotation in modes 1 to 3. DETAILED DESCRIPTION OF THE INVENTION

[0019] As shown in FIG. 1, the work vehicle has a pair of left and right front wheels 2 provided at the front lower portion of a machine frame 1, and a pair of left and right rear wheels 3 provided at the rear lower portion of the machine frame 1.

[0020] A working device 4 for cutting grass growing in the field is provided at the front of the body frame 1, a control unit 5 on which the operator sits is provided at the rear of the working device 4, a safety frame (ROPS) 6 for protecting the operator is provided at the rear of the control unit 5, a grass collection container 7 for storing the cut grass is provided at the rear of the safety frame 6, and an electric room 8 is provided below the grass collection container 7 in which an electric motor (the ``second electric motor'' in the claims) 40 that drives the front wheels 2, a battery 50, etc. are placed.

[0021] A steering column 10 that supports a steering wheel is provided in front of the driver's seat in the control section 5. A monitor that displays the output rotation speed of the electric motor 40 and the like is provided at the top of the steering column 10, and the bottom is fixed to the front part of the floor.

[0022] A brake pedal 11 for reducing the rotation speed of the front wheels 2 is provided on the left side of the steering column 10 on the floor, and an accelerator pedal 12 for increasing or decreasing the output rotation speed of the electric motor 40 for driving the front wheels 2 is provided on the right side. The depression amount of the accelerator pedal 12 is measured by an angle sensor 12S attached to the base of the accelerator pedal 12.

[0023] The area above the front wheel 2 is covered with a fender 13, and on the fender 13 located to the right of the driver's seat is provided a gearshift lever 14 for operating an inverter device 35 that increases or decreases the output rotation of a work electric motor (the "first electric motor" in the claims) 30 that drives the work implement 4, and on the right side of the gearshift lever 14 is provided a mode switch 15 for setting the power consumption of the electric motor 30 and the maximum output rotation and angular acceleration of the electric motor 40. The amount of operation of the gearshift lever 14 is measured by an angle sensor 14S attached to the base of the gearshift lever 14.

[0024] The rear of the working device 4 and the front of the grass collection container 7 are connected by a chute 16 extending in the front-to-rear direction, and a blower 17 for exhausting air into the chute 16 is provided in the middle of the front-to-rear direction of the chute 16.

[0025] 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 parts of the link arms 18 are fixed to the left and right parts of the safety frame 6 so that they can swing freely, and the safety frame 6 and the link arms 18 are connected by lifting parts 19 such as hydraulic cylinders, and the rear part of the bottom wall of the grass collection container 7 rests on a horizontal frame 21A of a support frame 21, which will be described later. This allows the lifting parts 19 to be driven to raise and lower the grass collection container 7.

[0026] As shown in Figures 2 and 3, the front motor chamber 8A of the motor chamber 8 is provided with the motor 30 and the motor 40, and the rear motor chamber 8B is provided with a battery 50 that stores the power to be supplied to the motor 30 and the like.

[0027] In a plan view, the electric motor 30 is provided on the left side of the center line in the left-right direction of the body frame 1, and the electric motor 40 is provided on the right side of the center line in the left-right direction of the body frame 1. By suppressing the weight difference between the weight applied to the left side of the center line in the left-right direction of the body frame 1 and the weight applied to the right side of the center line in the left-right direction of the body frame 1, it is possible to improve the steering performance.

[0028] When viewed from the side, a support frame 20 extending upward from the body frame 1 is provided in the partition between the front electric chamber 8A and the rear electric chamber 8B, and a support frame 21 extending upward from the body frame 1 is provided at the rear end of the rear electric chamber 8B.

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

[0030] The support frame 21 is formed of a left vertical frame 21L extending upward from the rear end of the left side of the body frame 1, a right vertical frame 21R extending upward from the rear end of the right side of the body frame 1, a horizontal frame 21A extending in the left-right direction connecting the upper parts of the left vertical frame 21L and the right vertical frame 21R, and a horizontal frame 21B extending in the left-right direction connecting the middle parts of the left vertical frame 21L and the right vertical frame 21R. The left part of the horizontal frame 21B extends leftward beyond the left vertical frame 21L, and the right part extends rightward beyond the right vertical frame 21R.

[0031] The middle part of the left vertical frame 20L and the left end part of the horizontal frame 21B are connected by a left front-rear frame 22L extending in the front-rear direction, and the middle part of the right vertical frame 20R and the right end part of the horizontal frame 21B are connected by a right front-rear frame 22R also extending in the front-rear direction. This allows the rear part of the battery 50 to be located above the drive shaft 46 of the rear wheel 3, preventing the vehicle frame 1 from being significantly deformed.

[0032] The upper part of the left vertical frame 20L and the middle part of the left vertical frame 23L provided at the rear of the control unit 5 are connected by a left front-rear frame 24L extending in the fore-and-aft 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 provided at the rear of the control unit 5 are connected by a right front-rear frame 24R extending in the fore-and-aft direction.

[0033] 4, the longitudinal direction of electric motor 30 is aligned along the front-to-rear direction. Electric motor 40 is aligned adjacent to and on the left side of electric motor 30, and the longitudinal direction of electric motor 40 is aligned along the front-to-rear direction.

[0034] A radiator 60 that cools water that cools the electric motor 30 and other components is provided on the outside of the left wall of the motor chamber 8, and a fan 61 that blows outside air toward the motor chamber 8 is provided between the radiator 60 and the electric motor 30. A circular opening (not shown) is formed in the left wall of the motor chamber 8 at a location facing the fan 61. This makes it possible to suppress a temperature rise in the electric motor 30 and other components, thereby preventing malfunctions of the electric motor 30 and other components. The fan 61 can also be provided on the left side of the radiator 60.

[0035] 5 to 7, the output shaft 30A of the electric motor 30 is connected to a reducer 31 provided below the electric motor 30. The output shaft 31A of the reducer 31 extends forward and is connected to a work clutch 32 provided between the reducer 31 and the transmission path of the working device 4.

[0036] An output shaft 40A of the electric motor 40 is connected to a reducer 41 provided in front of the electric motor 40. The output shaft 41A of the reducer 41 extends forward, and the output shaft 41B extends rearward and is connected to a 4WD clutch 43 provided between the transmission path of the reducer 41 and the rear wheels 3, which switches between front-wheel drive and four-wheel drive.

[0037] 8, the battery 50 is formed from four battery modules 50A. The upper parts of the four battery modules 50A are connected by a pair of left and right angle-shaped mounting frames 51 that are spaced a predetermined distance apart in the left-right direction and extend in the front-rear direction, and the lower parts are connected by a pair of left and right square pipe-shaped mounting frames 52 that are spaced a predetermined distance apart in the left-right direction and extend in the front-rear direction.

[0038] The front part of the mounting frame 51 extends forward of the battery 50, and the rear part extends rearward of the battery 50. The mounting frame 52 is formed to extend from the front end to the rear end of the battery 50.

[0039] As shown in Figure 9, the front part of the mounting frame 51 is removably fixed to the horizontal frame 20A of the support frame 20 by fastening members such as bolts, and the rear part is removably fixed to the horizontal frame 21A of the support frame 21 by fastening members such as bolts.

[0040] The left mounting frame 52 is placed on the left front-rear frame 22L, and the right mounting frame 52 is placed on the right front-rear frame 22R.

[0041] Openings 51A are formed in the front and rear of the mounting frame 51, through which hanging hooks can be inserted when replacing the battery 50. This allows the battery 50 to be easily attached to and detached from the support frames 20 and 21, making it easy to replace the battery 50.

[0042] 10 and 11 , an inverter device 35 for driving the electric motor 30 is provided at a predetermined distance in the front-to-rear direction behind the electric motor 30, and an inverter device 45 for driving the electric motor 40 is provided at a predetermined distance in the front-to-rear direction behind the electric motor 40. The inverter devices 35, 45 are also provided at a predetermined distance in the front-to-rear direction in front of the battery 50. This facilitates the routing of the electric motors 30, 40 and the inverter devices 35, 45. Furthermore, air blown from the fan 61 passes through the gaps between the electric motors 30, 40 and the inverter devices 35, 45, thereby enabling the electric motors 30, 40 and the inverter devices 35, 45 to be efficiently cooled.

[0043] As shown in FIG. 12, the output rotation of an output shaft 30A of an electric motor 30 is reduced in speed by a reducer 31 and then output from output shafts 31A and 31B of the reducer 31.

[0044] The output rotation of the output shaft 31A is transmitted to a work PTO 33 via a work clutch 32 to drive the work device 4. In addition, the output rotation of the output shaft 31B is transmitted to a hydraulic pump 34 that pressurizes and feeds oil to be supplied to the lifting component 19 and the like.

[0045] The output rotation of the output shaft 30A of the electric motor 30 is transmitted to a blower PTO 37 via a blower clutch 36 to drive the blower 17.

[0046] The output rotation of the output shaft 40A of the electric motor 40 is reduced by the reducer 41 and then output from the output shafts 41A and 41B of the reducer 41.

[0047] The output rotation of output shaft 41A is transmitted to a differential gear 42 for the front wheels to drive the front wheels 2, and the output rotation of output shaft 41B is transmitted to a differential gear 44 for the rear wheels via a 4WD clutch 43, and the output rotation of differential gear 44 is transmitted to a drive shaft 46 to drive the rear wheels 3.

[0048] As shown in FIG. 13, the controller 70 of the work vehicle is made up of a processing unit 71 consisting of a CPU or the like, a memory unit 72 consisting of a ROM, RAM, a hard disk drive, flash memory, etc., and a communication unit 73 for data communication with the outside.

[0049] The processing unit 71 calculates an output value to be output to the inverter device 45 based on the amount of depression of the accelerator pedal 12, calculates an output value to be output to the inverter device 35 based on the amount of operation of the shift lever 14, and calculates an output value to be output to the inverter device 35 based on the power consumption of the electric motor 30 that is preset for each mode selected by the mode switch 15.

[0050] Furthermore, when mode 1 to 3 is selected with mode switch 15, the calculation of the output value based on the depression amount of accelerator pedal 12 and the calculation of the output value based on the operation amount of gear shift lever 14 are restricted.

[0051] When the work vehicle is stopped, the memory unit 72 stores the mode that was selected by the mode switch 15 immediately before the work vehicle was stopped. This allows the work vehicle to be restarted in the mode that was selected immediately before the work vehicle was stopped, without having to select a new mode by the mode switch 15.

[0052] The communication unit 73 transmits and receives data to and from a portable controller (not shown).

[0053] The input side of the controller 70 is connected to an angle sensor 12S that measures the amount of depression of the accelerator pedal 12, which increases or decreases the output rotation of the electric motor 40 for driving, an angle sensor 14S that measures the amount of operation of the speed change lever 14, which increases or decreases the output rotation of the electric motor 30 for work, a mode switch 15, etc., via a predetermined input interface circuit.

[0054] The output side of the controller 70 is connected to an inverter device 35 that drives the work motor 30, an inverter device 45 that drives the travel motor 40, and the like via a predetermined output interface circuit.

[0055] As shown in FIG. 14 , in this embodiment, modes 1 to 3 can be selected using the mode switch 15. In mode 1, the power consumption of the work motor 30 is preset to low power consumption, and the maximum output rotation of the propulsion motor 40 is preset to low output rotation and low angular acceleration. In mode 2, the power consumption of the work motor 30 is preset to medium power consumption, the maximum output rotation of the propulsion motor 40 is preset to medium output rotation, and the angular acceleration is preset to medium angular acceleration. In mode 3, the power consumption of the work motor 30 is preset to high power consumption, the maximum output rotation of the propulsion motor 40 is preset to high output rotation, and the angular acceleration is preset to high angular acceleration. This allows for efficient mowing depending on the type of turfgrass planted in the field. For example, if the turfgrass is planted scattered throughout the field, mode 1 can be selected, and if the turfgrass is planted densely in a specific area of ​​the field, mode 3 can be selected. The settings of the work motor 30 can also be set to maximum torque, maximum current, and maximum power.

[0056] As shown in FIG. 15, power from battery 50 is supplied to controller 70 via power wiring P1, to inverter devices 35, 45 via power wiring P2, and to electric motors 30, 40 via power wiring P3.

[0057] The output value of controller 70 is input to inverter device 35 via output wiring S1, and the output value of inverter device 35 is input to electric motor 30 via output wiring S2. The output value of controller 70 is input to inverter device 45 via output wiring S3, and the output value of inverter device 45 is input to electric motor 40 via output wiring S4. In other words, the output rotations of electric motors 30 and 40 are controlled individually by inverter devices 35 and 45, respectively, and the output rotation of electric motor 30 is not affected by the output rotation of electric motor 40, and the output rotation of electric motor 40 is not affected by the output rotation of electric motor 30. This allows the operator to accurately predict the working time and travel distance that can be achieved by electric motors 30 and 40 consuming power from battery 50 for each of modes 1 to 3, thereby enabling the operator to efficiently plan the procedures for the reaping work.

[0058] Furthermore, the electric motor 30 that drives the working device 4 has a higher power consumption than the electric motor 40 that drives the front wheels 2. As a result, when the electric motors 30 and 40 consume power from the battery 50 to perform the mowing work, the working time of the mowing work can be extended by reducing the fluctuation in power consumption of the setting conditions of the electric motor 30.

[0059] 16 shows the relationship between the depression amount [%] of the accelerator pedal 12 and the travel speed [km / h] of the work vehicle. When the accelerator pedal 12 is fully depressed, the depression amount is 100 [%], and the travel speed of the work vehicle is 20 [km / h].

[0060] 16, the maximum output rotation of the electric motor 40 in modes 1 to 3 is set from low to high in the order of mode 1 to mode 3. As a result, in mode 1, the working vehicle travels slowly, so the load applied to the electric motor 30 from the grass via the working implement 4 is small, and fluctuations in the power consumption of the electric motor 30 can be further suppressed.

[0061] Furthermore, it is preferable to set the maximum output rotation of the electric motor 40 to a speed lower than the rated output rotation in modes 1 to 3. This allows the maximum output rotation to be maintained even when a load greater than the rated torque is applied to the electric motor 40 from the field via the front wheels 2.

[0062] The angular acceleration of the electric motor 40 in modes 1 to 3 is set from low to high in the order of mode 1 to mode 3. This allows the output rotation of the electric motor 40 to be quickly increased, so that in the event of sudden rainfall, the mode can be switched to mode 3 to quickly finish the mowing operation. [Explanation of symbols]

[0063] 1 Aircraft frame 2 front wheels 3 rear wheels 4 Work equipment 5 Control Unit 12 Accelerator pedal 14 Gear shift lever 15 Mode switch 30 Electric motor (1st electric motor) 40 Electric motor (second electric motor) 50 Battery

Claims

1. A work vehicle having a pair of left and right front wheels (2) and rear wheels (3) provided below a body frame (1), a working device (4) for cutting grass provided in front of the body frame (1), and a control section (5) for an operator to ride on provided above the body frame (1), A first electric motor (30) for driving the working device (4), a second electric motor (40) for driving the front wheels (2), and a battery (50) for supplying power to the first electric motor (30) and the second electric motor (40) are provided below and behind the steering section (5); A mode switch (15) is provided in the operating section (5), and drive conditions of the first electric motor (30) and the second electric motor (40) are preset for each mode selected by the mode switch (15); When a mode is selected by the mode switch (15), the output rotation of the first electric motor (30) is not increased or decreased by the output rotation of the second electric motor (40), and the first electric motor (30) is driven at a preset power consumption.

2. 2. A work vehicle according to claim 1, wherein the second electric motor (40) is driven at a preset maximum output rotational speed.

3. 3. A work vehicle according to claim 2, wherein the maximum output rotation speed of the second electric motor (40) is set to be lower than the rated output rotation speed of the second electric motor (40).

4. 4. A work vehicle according to claim 2 or 3, wherein the second electric motor (40) is driven at a preset angular acceleration.

5. The operating section (5) is provided with a speed change lever (14) for increasing or decreasing the output rotation of the first electric motor (30) and an accelerator pedal (12) for increasing or decreasing the output rotation of the second electric motor (40), 2. The work vehicle according to claim 1, wherein, when a mode is selected by the mode switch (15), the speed change lever (14) regulates the increase / decrease of the output rotation of the first electric motor (30) and the accelerator pedal (12) regulates the increase / decrease of the output rotation of the second electric motor (40).

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