Work vehicle

Abstract

To enhance responsiveness which restrains sudden acceleration in comparison with detecting a load based on acceleration.SOLUTION: A work vehicle can enhance responsiveness which restrains sudden acceleration in comparison with when detecting load at acceleration speed by supplying electrical power to electric motors (4, M0) with reference to a first electric energy (A1) as upper limit if a control part (300) actuates travel devices (2, 3) but does not actuate a work machine (18) and by supplying the electrical power to the electric motors (4, M0) with reference to a second electric energy (A2) as upper limit if it actuates the travel devices (2, 3) and actuates the work machine (18).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a work vehicle, and more particularly to a work vehicle in which a traveling device and a work implement are electrically driven. [Background technology]

[0002] In a forklift that uses an electric motor as a power source, a technology is known in which a first upper limit value and a second upper limit value are set as detection values ​​for detected acceleration, and when the detected acceleration is equal to or greater than the second upper limit value, the current value supplied to the traveling motor is reduced to suppress sudden acceleration of the forklift, and when the detected acceleration is equal to or less than the first upper limit value, the current value of the traveling motor is set to a target current value, thereby improving the acceleration responsiveness of the forklift (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-95113 Summary of the Invention [Problem to be solved by the invention]

[0004] Forklifts have a problem in that the load changes depending on the weight of the load, and the response is poor when detecting acceleration. Therefore, when the load is relatively light, there is a risk of sudden acceleration even when the second upper limit has not been reached. When a work vehicle equipped with a work machine such as a lawnmower suddenly accelerates, the work machine, which has many weak parts, is more likely to be damaged than the forks, which are relatively strong. Furthermore, lawnmowers sometimes have a higher upper speed limit than forklifts, which poses a greater risk to the driver.

[0005] The present invention has as its technical object to improve the responsiveness in suppressing sudden acceleration compared to when the load is detected by acceleration. [Means for solving the problem]

[0006] The above-mentioned problems of the present invention are solved by the following means. The invention described in claim 1 includes a vehicle body (1a), a work implement (18) supported by the vehicle body (1a) and performing work on a field, an electric motor (4, M0) having a first electric motor (4) that drives traveling devices (2, 3) of the vehicle body (1a) and a second electric motor (M0) that drives the work implement (18), and a control unit (300) that controls power supplied to the electric motor (4, M0), and that operates the traveling devices (2, 3) and drives the forward The control unit (300) supplies electric power to the electric motor (4, M0) up to a predetermined first electric power amount (A1) when the work implement (18) is not operated, and supplies electric power to the electric motor (4, M0) up to a predetermined second electric power amount (A2) that is greater than the first electric power amount (A1) when the traveling device (2, 3) is operated and the work implement (18) is operated.

[0007] The invention described in claim 2 is the work vehicle described in claim 1, characterized in that it includes an inclination detection means (302) that detects the inclination angle of the vehicle body (1a), and the control unit (300) that, when the inclination angle reaches a predetermined threshold, limits the amount of power supplied to the electric motor (4, M0) to an amount of power lower than the first amount of power (A1) and the second amount of power (A2).

[0008] The invention described in claim 3 is the work vehicle described in claim 1, characterized in that it comprises: power measurement means (305) that measures power consumption by the second electric motor (M0); and the control unit (300) that has a predetermined standard second lower limit value (A2b1) of power amount and a predetermined light load second lower limit value (A2b2) of power amount, and that, based on a measurement result of the power measurement means (305) while the work machine (18) is in operation, controls the lower limit value of power supplied to the electric motor (4, M0) to be reduced from the standard second lower limit value (A2b1) of power amount to the light load second lower limit value (A2b2) of power amount. [Effects of the Invention]

[0009] According to the invention of claim 1, when the control unit (300) operates the traveling device (2, 3) but does not operate the work machine (18), it supplies electric power to the electric motor (4, M0) up to the first electric power amount (A1), and when the control unit (300) operates the traveling device (2, 3) and operates the work machine (18), it supplies electric power to the electric motor (4, M0) up to the second electric power amount (A2), thereby improving responsiveness in suppressing sudden acceleration compared to when the load is detected by acceleration.

[0010] According to the invention of claim 2, in addition to the effect of the invention of claim 1, the control unit (300) limits the amount of electric power supplied to the electric motor (4, M0) when the tilt angle reaches a threshold value to an amount of electric power lower than the first amount of electric power (A1) and the second amount of electric power (A2), thereby making it possible to suppress sudden acceleration compared to when the amount of electric power is not limited.

[0011] According to the invention of claim 3, in addition to the effects of the invention of claim 1, when the power consumption does not reach the lower limit value (A2b1) of the second amount of electric energy for standard use, the control unit (300) controls the lower limit value of the electric energy to be supplied to the electric motor (4, M0) to be reduced from the lower limit value (A2b1) of the second amount of electric energy for standard use to the lower limit value (A2b2) of the second amount of electric energy for light load. This makes it possible to reduce energy loss compared to when the lower limit value (A2b2) of the second amount of electric energy for light load is not reduced. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is an explanatory diagram of a tractor as an example of a work vehicle according to an embodiment. [Figure 2] FIG. 2 is a functional block diagram of the control unit according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] FIG. 1 is an explanatory diagram of a tractor as an example of a work vehicle according to an embodiment. In Figure 1, a tractor 1, which is an example of a work vehicle of the present invention, is equipped with front wheels 2, 2 and rear wheels 3, 3 at the front and rear of a traveling body (an example of a vehicle main body) 1a. A traveling motor 4, which is an example of a first electric motor, is mounted below a driver's seat 8 at the rear of the traveling body 1a. The rotational power of the traveling motor 4 is appropriately reduced by a speed change device in a transmission case (not shown) and is configured to be transmitted to the front wheels 2, 2 and rear wheels 3, 3.

[0014] A container 7, which is an example of a work implement, is supported at the rear of the body of the tractor 1. Cut grass is stored in the container 7. Instead of the container 7, a work implement such as a cultivator that cultivates the ground (field) behind the tractor 1 can be attached to the rear of the tractor 1. Power is transmitted to the transport device of the container 7 via a PTO shaft (rear PTO shaft) not shown, and the cut grass is sent into the container 7. Drive is transmitted to the PTO shaft in this embodiment from a PTO motor M0, which is an example of a second electric motor. In the tractor 1 of this embodiment, a lawnmower 18, as an example of a work machine, is supported between the front wheels 2 and the rear wheels 3. Power is transmitted to the lawnmower 18 via a second PTO shaft (mid-PTO shaft), not shown. The second PTO shaft is driven by a PTO motor M0, but it is also possible to install a separate motor dedicated to the second PTO shaft. In this specification, the left and right sides of the tractor 1 when viewed in the forward direction are referred to as the left and right sides, respectively, and the forward direction is referred to as the front side, and the backward direction is referred to as the rear side.

[0015] A driver's seat (operating seat) 8 is disposed at the top of the traveling vehicle body 1a, and a steering wheel 10 is disposed in front of the driver's seat 8. Also disposed in front of the driver's seat 8 are a display panel (meter panel) for a speedometer (not shown) and various operation switches (not shown). Disposed below and in front of the driver's seat 8 are driving operation devices such as a brake pedal 12 and an accelerator pedal 13 having a forward pedal and a reverse pedal.

[0016] In Figure 1, lift arms 15, 15 are pivotally mounted to the rear of the traveling vehicle body 1a. Lift rods (not shown) are interposed and connected between the lift arms 15, 15 and lower links 16, 16. A container 7 is attached to the lift arms 15 and the lower links 16, but instead of the container 7, a work machine such as a tiller can be attached.

[0017] The lift arms 15 are driven by hydraulic cylinders (not shown). When the hydraulic pressure in the hydraulic cylinders increases and the lift arms 15, 15 are rotated upward, the work equipment (container, etc.) is raised via the lift rods, lower links 16, etc. When the hydraulic oil is discharged and the hydraulic pressure decreases, the lift arms 15, 15 are lowered. Therefore, when the grass collected in the container 7 is to be discharged, the lift arms 15 are raised, the rear end of the container 7 is turned downward, and the grass is discharged from the rear end. The working machines that can be attached to the rear of the traveling vehicle body 1a include rotary tillers for agricultural work, plows, seed sowing machines, seedling transplanters, fertilizer spreaders, chemical sprayers, and the like.

[0018] (Explanation of the tractor control unit) FIG. 2 is a functional block diagram of the control unit according to the embodiment. The tractor of the embodiment has a control unit 300 that controls each function. The control unit 300 has an input / output interface I / O that performs input and output of signals with the outside. The control unit 300 also has a read-only memory (ROM) that stores programs and information for performing necessary processing. The control unit 300 also has a random access memory (RAM) for temporarily storing necessary data. The control unit 300 also has a central processing unit (CPU) that performs processing according to programs stored in the ROM or the like. Therefore, the control unit 300 of the embodiment is configured with a small information processing device, a so-called microcomputer. Therefore, the control unit 300 can realize various functions by executing programs stored in the ROM or the like.

[0019] The control unit 300 receives signals from a display panel (not shown), which is an example of an input unit and an example of a display unit, and is composed of a touch panel, as well as signal input elements such as a positioning device SN1, a power measuring device SN2, a work machine switch SW1, and various other sensors not shown.

[0020] The positioning device SN1 has a GNSS (Global Navigation Satellite System) receiver SN1a and an IMU (Inertial Measurement Unit, an example of an inclination measurement component) SN1b. The GNSS receiver SN1a receives positioning signals from artificial satellites and can measure the current position of the tractor. The IMU SN1b measures acceleration and angular velocity and can measure the direction (direction of travel) and attitude (left-right tilt and front-back tilt) of the tractor. Therefore, by correcting the measurement results of the GNSS receiver SN1a with the IMU SN1b, the current position can be measured with higher accuracy than when the current position is measured using only the GNSS method.

[0021] The power measurement device SN2 measures the power supplied from the battery 5a (see FIG. 1) inside the hood 5 to the traveling motor 4 and the PTO motor M0. As an example, an ammeter can be used as the power measurement device SN2, and an ammeter connected to the output terminal of the battery 5a can be used. In the embodiment, the ammeters are individually arranged according to the power supply system so as to individually measure the power supplied to each of the traveling motor 4 and the PTO motor M0, but this is not limiting. It is also possible to measure the sum of the output currents. The work machine switch SW1 is operated to input "ON" to operate the lawn mower 18 or "OFF" to stop the lawn mower 18.

[0022] The control unit 300 sends control signals to the power supply circuit E, the travel motor 4, the PTO motor M0, the hydraulic cylinder S1, etc., as examples of controlled elements, to control the running / stopping and running speed of the tractor 1, the operation / stopping and operating speed of the lawn mowing device 18, and the raising / lowering and operation / stopping of the work machine (container 7) attached to the lift arm 15. The control unit 300 can also output a control signal to a display monitor, which is an example of a display unit, to display work information, work status, the vehicle position, and the like. The tractor 1 of this embodiment is equipped with a total of two electric motors 4, M0, including the travel motor 4 and the PTO motor M0. The number of electric motors is not limited to two, and it is possible to have a total of three (or more) motors by providing a PTO motor for the lawn mower 18 and one for the rear implement, or it is possible to use only one electric motor, the travel motor 4, by using the power of the travel motor 4 to drive the lawn mower 18 and the rear implement.

[0023] The positioning means 301 measures the current position of the tractor 1 based on the measurement results of the positioning device SN1. The tilt detection means 302 detects the tilt of the tractor 1 based on the detection result of the IMU SN1b.

[0024] The driving control means 303 controls the driving motor 4 in response to inputs to the accelerator pedal 13, brake pedal 12, steering wheel 10, and a speed change lever (not shown), thereby controlling the driving (acceleration / deceleration, steering, braking) of the tractor 1. The work implement control means 304 controls the PTO motor M0 in response to inputs to the work implement switch SW1, a work speed setting switch (not shown), etc., to control the operation of the lawnmower 18. If a work implement is attached to the rear, the work implement control means 304 also controls the operation of the attached work implement.

[0025] The power measurement means 305 measures the power consumption of the travel motor 4 and the PTO motor M0 based on the measurement results of the power measurement device SN2. Note that the power measurement means 305 in this embodiment measures the power consumption of the travel motor 4 and the power consumption of the PTO motor M0. The travel control means 303 requests power supply to the travel motor 4 so that the vehicle travels at a target speed according to operation. Therefore, as the travel load increases, the amount of power requested of the travel motor 4 increases to maintain the target speed. Therefore, by monitoring the power consumption of the travel motor 4, the load on the travel motor 4 can also be monitored. Similarly, the work machine control means 304 requests power supply to the PTO motor M0 so that the work machine operates at a predetermined operating speed. Therefore, as the work load increases, the amount of power requested of the PTO motor M0 increases. Therefore, by monitoring the power consumption of the PTO motor M0, the load on the PTO motor M0 can also be monitored. Therefore, the power measurement means 305 in this embodiment also has the function of measuring the load on the travel and the load on the work machine through power consumption.

[0026] The power supply control means 306 has a first power amount storage means 306a and a second power amount storage means 306b, and controls the power supply circuit E to control the power supply to each part of the tractor 1. The first electric power amount storage means 306a stores, as the first electric power amount A1, the upper limit of the amount of electric power to be supplied to the electric motors 4, M0 when the wheels 2, 3 are operated by the traction motor 4 and the lawn mower 18 is not operated by the PTO motor M0. The second power amount storage means 306b stores, as the second power amount A2, the upper limit of the amount of power to be supplied to the electric motors 4 and M0 when the wheels 2 and 3 are operated by the travel motor 4 and the lawn mower 18 is operated by the PTO motor M0.

[0027] In this embodiment, as an example, the current values ​​of the current supplied from the power supply circuit E are stored as the first electric power amount A1 and the second electric power amount A2. Therefore, in this embodiment, the second electric power amount (second current value) A2 is set to a larger value than the first electric power amount (first current value) A1. Note that the second electric power amount (second current value) A2 is not limited to the current value, and any parameter related to the amount of electric power supplied to the traveling motor 4 or the PTO motor M0, such as a voltage value, can be used. In addition, the first electric power amount A1 and the second electric power amount A2 are predetermined when the tractor 1 is shipped from the factory, but they can also be changed by an operator, service engineer, etc., or can be changed automatically in response to deterioration of the battery 5a over time.

[0028] In this embodiment, when the work implement (lawn mower 18) is not operating based on the input of work implement switch SW1, the power supply control means 306 limits the upper limit of the current supplied to the travel motor 4 when traveling using the travel motor 4 to a first current value (A1). Therefore, even if sudden acceleration is likely to occur due to operating the accelerator pedal 13 or the like, or when overcoming unevenness or slopes in the field, or when climbing over stones or obstacles in the field, travel using the travel motor 4 is limited to the first current value (A1), and sudden acceleration is suppressed.

[0029] Furthermore, in this embodiment, the power supply control means 306 limits the upper limit of the total current supplied to the travel motor 4 and PTO motor M0 to a second current value (A2) when the work implement (lawnmower 18) is operating based on input from the work implement switch SW1 and the vehicle is traveling using the travel motor 4. Therefore, even if sudden acceleration is likely to occur due to operation of the accelerator pedal 13 or the like, or due to unevenness or slopes in the field, or overcoming stones or obstacles (ridges, etc.) in the field, or if the load on the lawnmower 18 suddenly increases and the traveling load increases when passing through an area with dense or long grass, causing the vehicle to suddenly decelerate, or if the load on the lawnmower 18 suddenly decreases and the traveling load becomes lighter when passing through an area with sparse or short grass, causing the vehicle to suddenly accelerate, the power supply to the travel motor 4 and PTO motor M0 is limited to the second current value (A2), preventing sudden acceleration and other such occurrences.

[0030] Therefore, the power supply control means 306 in this embodiment controls the first power amount A1 or the second power amount A2 depending on whether the work machine (lawn mower 18) is operating or not. Therefore, compared to conventional technology where the load is detected by measured acceleration, the determination of whether the work machine is operating or not allows for faster and more reliable control to limit the power amounts A1 and A2, improving responsiveness in suppressing sudden acceleration. In the embodiment, a lawnmower 18 is used as an example of a working machine, but the values ​​of the electric energy amounts A1 and A2 can be different depending on the type of working machine (rotary tiller, plow, seed sower, seedling transplanter, fertilizer spreader, chemical sprayer, etc.). For example, some working machines, such as plows, create significant resistance to travel when in contact with the field, but when the plow temporarily floats due to uneven ground, the load is removed and the machine is prone to rapid acceleration. Other working machines, such as rotary tillers, generate an acceleration force when the rotating rotary comes into contact with the ground (a negative load, so to speak), but lose the acceleration force when the rotary comes off the ground. Therefore, because the load on travel differs depending on the type of working machine, it is desirable to set the electric energy amounts A1 and A2 according to the load.

[0031] In particular, the power supply control means 306 of this embodiment limits the upper limit (A1a or A2a) of the amount of power supplied to the electric motor 4, M0 to a low amount of power when the tilt angle θ1 of the traveling vehicle body 1a detected by the tilt detection means 302 reaches a predetermined threshold θ0. As an example, when the tilt angle θ1 of the traveling vehicle body 1a is downward-facing, that is, when traveling downhill, the power supply control means 306 limits the upper limit to an amount of power (A1-A0) lower than the first amount of power A1 when the working machine (lawn mower 18) is not operating, and limits the upper limit to an amount of power (A2-A0) lower than the second amount of power A2 when the working machine is operating, thereby suppressing sudden acceleration. Although the example has been given in which the reduction value A0 of the electric energy is a common value for the first electric energy A1 and the second electric energy A2, this is not limiting. For example, it is also possible to use different reduction values ​​A0 and A0', such as A1-A0 and A2-A0'. Furthermore, when the historical information on the detection results of the inclination angle θ1 indicates that downhill and uphill slopes are repeated within a predetermined time, i.e., when the field is highly uneven and has many ups and downs, it is preferable to similarly limit the electric energy to a low value (A1-A0 or A2-A0).

[0032] In the embodiment, a standard lower limit A2b1 and a light load lower limit A2b2 are pre-registered for the lower limit A2b of the second electric energy A2. The light load lower limit A2b2 is set to a value lower than the standard lower limit A2b1. In the embodiment, the power supply control means 306 controls the lower limit of the electric power supplied to the electric motors 4 and M0 so as to decrease from the standard second electric energy lower limit A2b1 to the light load second electric energy lower limit A2b2 when the power consumption measured by the electric energy measurement means 305 does not reach the standard lower limit A2b1.

[0033] Depending on the type of grass (thick or thin stems) and the condition of the grass and the field, such as the growth rate, the workload of the lawnmower 18 may be very light. To prevent clogging, the lawnmower 18 sets a lower limit (standard lower limit A2b1) for the amount of power supplied to the lawnmower 18 during operation. Specifically, the PTO motor M0 is controlled to receive power equal to the standard lower limit A2b1 at the start of operation, and as the load increases, the power supply is increased within the range of the upper limit (second power amount A2). When the load during operation is light and the amount of power required of the PTO motor M0 is lower than the standard lower limit A2b1, energy loss (waste of energy) occurs. In other words, the implement rotates at an unnecessarily high rotational speed. To address this, in this embodiment, when the required amount does not reach the standard lower limit A2b1, the amount is controlled to decrease to the light-load lower limit A2b2. This reduces the operating speed of the work implement by the PTO motor M0, reduces power consumption, and reduces energy loss.

[0034] The reduction from the standard lower limit value A2b1 to the light load lower limit value A2b2 may be performed by suddenly switching, or by gradually reducing it in stages (over time) through two or more stages, or by gradually reducing it continuously in a linear or non-linear manner. Furthermore, if the load on the work machine increases while power is being supplied at the light load lower limit A2b2, causing the amount of power requested of the PTO motor M0 from the work machine control means 304 to increase, it is possible to switch from the light load lower limit A2b2 to the standard lower limit A2b1. At this time, it is possible to quickly or gradually switch to the standard lower limit A2b1, or it is also possible to control the power supply to the PTO motor M0 to increase while suppressing the power supply to the traveling motor 4 until the rate of change in the requested amount reaches a predetermined range (when the load increases but remains within the light load range).

[0035] Furthermore, in the embodiment, the amount of power required for the electric motor 4,M0 changes depending on the running load and the work load, and power is supplied according to the required amount. However, this is not limiting. It is also possible to control the power supply depending on the temperature of the electric motor 4,M0. That is, when the temperature of the electric motor 4,M0 is high, for example, if the temperature rises due to continuous use and further use of the electric motor 4,M0 is likely to cause the electric motor 4,M0 to break down, the electric power supply can be zeroed or reduced (output limited) and the electric motor 4,M0 can be stopped or slowed down. In this case, it is preferable to perform deceleration control of the electric motor 4,M0 when the output limit temperature is reached, and to stop the electric motor 4,M0 when the stop temperature, which is higher than the output limit temperature, is reached. The deceleration control can be performed in stages or in proportion to the temperature.

[0036] The control according to temperature can be the same for the traveling motor 4 and the PTO motor M0, or different controls can be used for each. Furthermore, the control is not limited to being based on the temperature of the electric motor 4, M0, and it is also possible to adopt a mode in which the power supply is restricted according to the temperature of the power supply circuit E including an inverter, etc. In this case, the temperature at which the output is restricted is generally set to be different between the temperature of the electric motor 4, M0 and the temperature of the power supply circuit E, and it is possible to individually restrict or stop the output when either temperature reaches the output restriction temperature or stop temperature, or, since individual control reduces the accuracy of the operation, it is also possible to restrict or stop the output of all the electric motors 4, M0 when either temperature reaches the output restriction temperature or stop temperature.

[0037] When the output of either the electric motor 4 or the electric motor M0 is limited or stopped, it is desirable to notify the operator by a display panel or the like. Furthermore, once the output of the motor 4, M0 is limited or stopped, it is desirable that it not automatically return to normal even if the temperature drops due to natural cooling, but that it return to normal when the operator makes a specified input (such as turning the key off and then on again).This is because if the motor 4, M0 automatically returns to normal while the operator is checking the tractor 1 with the motor 4, M0 stopped, there is a risk that the tractor 1 or the implement may suddenly start moving, causing an accident.

[0038] In the above embodiment, the tractor 1 is operated by the electric motor 4, M0, but this is not limiting. The present invention can also be applied to a tractor 1 equipped with an electric motor 4, M0 and an internal combustion engine (engine), i.e., a tractor equipped with a so-called hybrid engine. In this case, even in a configuration in which the traveling and the work equipment are driven by power from the engine and the electric motor 4, M0 is used as an assist (support), it is possible to suppress sudden acceleration by limiting the electric power amounts A1, A2 as in the embodiment. When the engine is assisted by the electric motor 4, M0, the electric motor 4, M0 may be turned on and off based on the engine speed, or a clutch that transmits power from the electric motor 4, M0 may be turned on and off based on the engine speed. Assistance may be performed, for example, when the actual rotation speed is insufficient compared to the target rotation speed, and the strength of the assist may be controlled by controlling the power supplied to the electric motor 4, M0 according to the insufficient rotation speed. Assistance may also be performed only when the work equipment is operating and not performed when the work equipment is not operating.

[0039] If an engine is installed, it is desirable to provide a function for calculating the amount of CO2 (carbon dioxide) emissions during use. The amount of CO2 emissions can then be displayed on a display panel or a tablet device that can communicate with the tractor 1. At this time, by allowing the user to input the type of fuel used (gasoline, diesel, biofuel, e-fuel, etc.) and its blend ratio, it is also possible to calculate and display the amount of CO2 emissions according to the type of fuel. This makes it possible to disclose the exact amount of CO2 emitted during crop production. For example, if HVO fuel (hydrogenated vegetable oil fuel), which is made by hydrotreating waste oil, or e-fuel, a synthetic liquid fuel made from carbon dioxide and hydrogen, is used, it is possible to convert CO2 emissions to "0" because these are 100% carbon-neutral fuels. It is also possible to reduce the need for manual input by providing a sensor for determining the type of fuel.

[0040] It is also preferable to register and manage the amount of CO2 emitted during the manufacture of materials used during work, such as chemical fertilizers, in association with the amount of CO2 emitted during the travel and operation of the tractor 1. By managing the amount of CO2 emitted for each material used for each field based on the location information measured by the positioning means 301, or by each task such as soil preparation, tilling, and sowing, it becomes possible to disclose the amount of CO2 emitted during the production of each crop harvested in each field. [Explanation of symbols]

[0041] 1...Work vehicle, 1a...Vehicle body, 2,3...Travel gear, 4...first electric motor, 4,M0...Electric motor, 18...Work equipment, 300...control unit, 302...Tilt detection means, 305...Power measurement means, A1: First power amount, A2: Second power amount, A2b1: Lower limit of the second power amount for standard use. A2b2: Lower limit of the second energy amount for light loads. M0...Second electric motor.

Claims

1. A vehicle body (1a), a work machine (18) supported by the vehicle body (1a) and configured to perform work on a field; an electric motor (4, M0) including a first electric motor (4) that drives the traveling device (2, 3) of the vehicle body (1a) and a second electric motor (M0) that drives the working machine (18); a control unit (300) that controls a power source to be supplied to the electric motor (4, M0), the control unit (300) supplying electric power to the electric motor (4, M0) up to a predetermined first electric power amount (A1) when the traveling device (2, 3) is operated and the working machine (18) is not operated, and supplying electric power to the electric motor (4, M0) up to a predetermined second electric power amount (A2) that is larger than the first electric power amount (A1) when the traveling device (2, 3) is operated and the working machine (18) is operated; A work vehicle comprising:

2. An inclination detection means (302) for detecting the inclination angle of the vehicle body (1a); the control unit (300) limiting the amount of power supplied to the electric motor (4, M0) to an amount of power lower than the first amount of power (A1) and the second amount of power (A2) when the tilt angle reaches a predetermined threshold value; 2. The work vehicle according to claim 1, further comprising:

3. a power measurement means (305) for measuring the power consumption of the second electric motor (M0); the control unit (300) having a predetermined standard second lower limit value (A2b1) of the amount of electric energy and a predetermined light load second lower limit value (A2b2) of the amount of electric energy, and controlling, based on a measurement result of the electric power measurement means (305) during operation of the work machine (18), when the measured power consumption does not reach the standard second lower limit value (A2b1) of the amount of electric energy, to reduce the lower limit value of the electric energy to be supplied to the electric motor (4, M0) from the standard second lower limit value (A2b1) to the light load second lower limit value (A2b2); 2. The work vehicle according to claim 1, further comprising:

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