electric work vehicle

Abstract

To provide an electric working vehicle that can properly travel or start working, even in a state where a motor is rotating at a speed of 0 rpm or at a minimum speed.SOLUTION: An electric working vehicle is provided with: a motor M that drives at least either of travelling devices (10 and 11) and a working device; speed changers (38 and 39) that perform operation of changing a speed of rotative power for driving the travelling devices (10 and 11) or the working device; an accelerator operating tool 37 that performs operation of increasing / decreasing a motor rotating speed of the motor M; and a motor control part 54 that controls the motor rotating speed in accordance with operation to the accelerator operating tool 37. While the motor M is in operation, a predetermined notification is made.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an electric work vehicle in which a traveling device is driven by a motor. [Background technology]

[0002] As shown in Patent Document 1, an electric tractor (electric work vehicle) uses a motor to drive both the travel device and the work device. An electric work vehicle such as an electric tractor is equipped with various operating tools, and the motor and other components are controlled based on the operation of the various operating tools to travel and work. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-150560 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the motor can be in standby mode with a rotation speed of 0 rpm, and if the wrong procedure is performed when the motor is in a 0 rpm state, the machine may suddenly accelerate and may not be able to start running or working properly.

[0005] An object of the present invention is to start traveling or work appropriately even when the motor rotation speed is 0 rpm or at very low rotation speed. [Means for solving the problem]

[0006] In order to achieve the above object, an electric work vehicle according to one embodiment of the present invention comprises a motor that drives at least one of a traveling device and a working device, a speed change device that changes the speed of the rotational power that drives the traveling device or the working device, an accelerator operation device that increases or decreases the motor rotation speed of the motor, and a motor control unit that controls the motor rotation speed in response to operation of the accelerator operation device, and to Leave, When it is detected that the accelerator operation device has been operated after the gear shift operation device has been operated, the operation is detected as an inappropriate operation that may cause the vehicle to suddenly start, Motor suppression control to suppress increases in motor output but It will be held.

[0007] When starting the vehicle, if a driver mistakenly believes that the motor is stopped even though it is operating at low speed and operates the gearshift and accelerator in an inappropriate manner, the motor speed may increase, causing the vehicle to suddenly start moving unintentionally.Furthermore, when operating a work device, if a driver mistakenly believes that the motor is stopped even though it is operating at low speed and operates the gearshift and accelerator in an inappropriate manner, the motor speed may increase, causing the work device to suddenly start moving unintentionally.

[0008] According to the above configuration, a predetermined notification is issued while the motor is running, allowing the operator (work vehicle driver) to recognize that the motor is running. This prevents the operator from mistakenly thinking that the motor is stopped when it is actually running at low speed, and allows the operator to be aware of operating the gear shifter and accelerator pedal in the appropriate order. As a result, the vehicle can be driven or work can be started appropriately.

[0009] Also, a predetermined method for preventing the inappropriate operation; Notification but, This may be performed when the motor rotation speed is 0 or equal to or less than a predetermined first rotation speed after the speed change device is operated.

[0010] By operating the speed change operating device after appropriately increasing the motor rotation speed with the accelerator operating device, the rate at which the rotational power increases is moderated by the power transmission mechanism that transmits power from the motor to the traveling device or working device.

[0011] Therefore, by issuing a notification when the motor rotation speed is 0 or almost no after the gearshift operating device is operated, the operator can recognize that the motor M is running. As a result, the operator can be aware of the need to operate the gearshift operating device and accelerator operating device in the appropriate procedure, and can start driving or working appropriately.

[0012] Furthermore, when the speed change device is operated while the motor rotation speed is equal to or lower than the first rotation speed, the motor control unit increases the motor rotation speed to a predetermined speed higher than the first rotation speed. The aircraft will not take off The rotation speed may be set to a second rotation speed or less, and the notification may be made by the sound of the motor rotating.

[0013] With this configuration, the motor rotation speed is set to the second rotation speed, and the motor generates a motor sound. The motor sound allows the operator to recognize that the motor is running. This allows the operator to be aware of the need to operate the gear shifter and accelerator pedal in the appropriate order, allowing the operator to start driving or working appropriately.

[0014] In addition, the motor control unit may control the motor rotation speed so that it does not exceed an idling rotation speed, which is a predetermined rotation speed greater than 0 rotations, while the motor is operating, and the notification may be made by the sound of the motor rotating.

[0015] With this configuration, the motor rotation speed is set to an idling speed or lower, at which the travel device and work device are barely operating, and the motor generates a motor noise. The motor noise allows the operator to recognize that the motor is running. This allows the operator to be aware of the need to operate the gear shifter and accelerator pedal in the appropriate order, allowing the operator to start travel or work appropriately.

[0016] The device may further include a notification unit that issues the notification.

[0017] This configuration allows the operator to recognize that the motor is running, which in turn helps the operator to be aware of the proper procedures for operating the gear shifter and accelerator pedal, allowing the operator to start driving or working appropriately.

[0018] The notification unit may be a speaker that emits a warning sound, and the notification may be made by the warning sound.

[0019] This configuration allows the operator to recognize that the motor is running by the warning sound, which helps the operator to be aware of the need to operate the gear shifter and accelerator pedal in the appropriate order, allowing the operator to start driving or working appropriately.

[0020] The notification unit may be a warning light, and the notification may be made by turning on or flashing the warning light.

[0021] With this configuration, the operator can recognize that the motor is running by the warning light being lit or flashing, which helps the operator to be aware of the need to operate the gear shifter and accelerator pedal in the appropriate order, allowing the operator to start driving or working appropriately.

[0022] The vehicle may further include a hydrostatic continuously variable transmission that changes the speed of the rotational power transmitted from the motor to the traveling device, and the speed change operating device may include an HST operating device that operates the angle of a swash plate of the hydrostatic continuously variable transmission.

[0023] This configuration allows the operator to recognize that the motor is running even if the HST operating device that controls the angle of the swash plate of the hydrostatic continuously variable transmission is not operated in the correct order, which helps the operator to be aware of the need to operate the transmission operating device in the correct order and allows the vehicle to start traveling properly.

[0024] The speed change operating device may also include a PTO operating device that changes the speed of the rotational power transmitted from the motor to the working device.

[0025] This configuration allows the operator to recognize that the motor is running even if the PTO operating device, which changes the speed of the rotational power, is not operated in the proper procedure. This allows the operator to be aware that the speed change device should be operated in the proper procedure, and allows the operator to start work appropriately. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 2 is a left side view of the tractor. [Figure 2] FIG. 2 is a left side view showing the arrangement of an inverter and the like. [Figure 3] FIG. 2 is a diagram illustrating a flow of power transmission. [Figure 4] 3A and 3B are diagrams illustrating the configuration of an operating tool in a driving section. [Figure 5] FIG. 2 is a diagram illustrating a functional configuration for controlling a motor. [Figure 6] FIG. 4 is a diagram illustrating a processing flow of motor suppression control in the first embodiment. [Figure 7] 10 is a diagram illustrating an example of a rotation speed transition, which is a change in the motor rotation speed relative to the operation amount of the accelerator lever. FIG. [Figure 8]FIG. 10 is a diagram illustrating a flow of notification in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] An embodiment of the present invention will be described with reference to the drawings. In the following description, unless otherwise specified, the direction of arrow F in the drawings will be referred to as "front," the direction of arrow B as "rear," the direction of arrow L as "left," and the direction of arrow R as "right." Furthermore, the direction of arrow U in the drawings will be referred to as "up," and the direction of arrow D as "down."

[0028] [Overall configuration of the tractor] In the following, an electric tractor (hereinafter simply referred to as "tractor") will be described as an electric work vehicle according to this embodiment. As shown in Figure 1, the tractor has left and right front wheels 10, left and right rear wheels 11, and a cover member 12.

[0029] The tractor also includes a machine frame 2 and a driving section 3. The machine frame 2 is supported by left and right front wheels 10 (corresponding to "traveling devices") and left and right rear wheels 11 (corresponding to "traveling devices").

[0030] The cover member 12 is disposed at the front of the vehicle body, and the driving section 3 is provided behind the cover member 12. In other words, the cover member 12 is disposed in front of the driving section 3.

[0031] The driving section 3 has a protective frame 30, a driving seat 31, and a steering wheel 32. An operator (worker / driver) can sit in the driving seat 31. This allows the operator to get on the driving section 3. The left and right front wheels 10 are steered by operating the steering wheel 32. The operator can perform various driving operations in the driving section 3.

[0032] The tractor is equipped with a traction battery 4. The cover member 12 is configured to be swingable about an opening / closing axis Q that extends in the left-right direction of the vehicle body. This allows the cover member 12 to be opened and closed. When the cover member 12 is in the closed state, the traction battery 4 is covered by the cover member 12.

[0033] As shown in Fig. 2, the tractor includes an inverter 14 and a motor M (electric motor). The traction battery 4 supplies power to the inverter 14. The inverter 14 converts DC power from the traction battery 4 into AC power and supplies it to the motor M. The motor M is then driven by the AC power supplied from the inverter 14.

[0034] 2 and 3, the tractor is equipped with a hydrostatic continuously variable transmission 15 and a transmission 16. As shown in Fig. 3, the hydrostatic continuously variable transmission 15 has a hydraulic pump 15a and a hydraulic motor 15b.

[0035] The hydraulic pump 15a is driven by rotational power from the motor M. When the hydraulic pump 15a is driven, rotational power is output from the hydraulic motor 15b. The hydrostatic continuously variable transmission 15 is configured so that the speed of the rotational power is changed between the hydraulic pump 15a and the hydraulic motor 15b. The hydrostatic continuously variable transmission 15 is also configured so that the gear ratio can be changed continuously.

[0036] The rotational power output from the hydraulic motor 15b is transmitted to the transmission 16. The rotational power transmitted to the transmission 16 is changed in speed by a gear-type speed change mechanism of the transmission 16 and distributed to the left and right front wheels 10 and the left and right rear wheels 11. In this way, the left and right front wheels 10 and the left and right rear wheels 11 are driven.

[0037] 2 and 3, the tractor is also equipped with a mid PTO shaft 17 and a rear PTO shaft 18 (hereinafter, these may be collectively referred to simply as "PTO shafts"). Rotational power output from the motor M is distributed to the hydraulic pump 15a, the mid PTO shaft 17, and the rear PTO shaft 18. This causes the mid PTO shaft 17 and the rear PTO shaft 18 to rotate.

[0038] If a working device is connected to the mid PTO shaft 17 or the rear PTO shaft 18, the working device will be driven by the rotational power of the mid PTO shaft 17 or the rear PTO shaft 18. For example, as shown in FIG. 2, in this embodiment, a brush cutting device 19 is connected to the mid PTO shaft 17. The brush cutting device 19 is driven by the rotational power of the mid PTO shaft 17.

[0039] [Travel and work operations] As shown in Figures 1 and 4, the driving section 3 is provided with various operating devices for driving or working. For example, the operating devices include a main shift lever 34, a sub-shift lever 35, an accelerator lever 37 (corresponding to an "accelerator operating device"), an HST pedal 38 (corresponding to a "shift operating device" and an "HST operating device"), and a PTO lever 39 (corresponding to a "shift operating device" and an "PTO operating device"). Note that although these operating devices are described as levers and pedals, they may each be operating devices in any form.

[0040] The main speed change lever 34 and the sub-speed change lever 35 are provided on the left side of the driver's seat 31 and are used to set the vehicle speed for forward and reverse travel. The accelerator lever 37 is provided on the right side of the steering wheel 32 and is used to increase or decrease the rotation speed of the motor M. The PTO lever 39 is provided on the left side of the driver's seat 31 and is used to change the rotational power of the PTO shaft.

[0041] The HST pedal 38 is located on the floor of the driver's section 3, to the right of and in front of the driver's seat 31. The HST pedal 38 is operated with the right foot by an operator seated in the driver's seat 31 and is used to start forward and reverse travel and to adjust the vehicle speed. In this case, the vehicle speed is limited to a range of vehicle speeds set by the main shift lever 34 and the auxiliary shift lever 35. The HST pedal 38 receives a speed change operation for the rotational power that drives the wheels (front wheels 10 and rear wheels 11). When the HST pedal 38 is tilted forward from the neutral position, the angle of the swash plate of the hydrostatic continuously variable transmission 15 is changed, causing the vehicle to move forward. When the HST pedal 38 is tilted backward from the neutral position, the angle of the swash plate of the hydrostatic continuously variable transmission 15 is changed, causing the vehicle to move backward. The vehicle speed can be controlled by the amount the HST pedal 38 is tilted forward or backward.

[0042] When the machine is to be driven, the main speed change lever 34 and the sub-speed change lever 35 are first operated with the motor M running to set the maximum vehicle speed for forward or reverse. Next, the accelerator lever 37 is operated to adjust the rotation speed of the motor M to a rotation speed suitable for driving and work. Then, the HST pedal 38 is operated to start the machine moving. By operating in this order, the hydrostatic continuously variable transmission 15 reduces the sudden transmission of the rotational power of the motor M to the wheels (front wheels 10 and rear wheels 11), preventing the machine from suddenly starting to move.

[0043] At this time, when adjusting the power of the PTO shaft, the accelerator lever 37 is operated to adjust the rotational speed of the motor M, and then the PTO lever 39 is operated to adjust the rotational power appropriate for the work to be output to the PTO shaft. By operating in this order, the hydrostatic continuously variable transmission 15 reduces the abrupt transmission of the rotational power of the motor M to the working device, preventing the working device from operating suddenly.

[0044] If the operator does not realize that the motor M is running and does not operate the operating tools in the proper procedure as described above, the vehicle may not be able to start traveling properly, and work may not be performed properly. For example, if the accelerator lever 37 is operated after the HST pedal 38 is operated, the rotational power of the motor M may be transmitted abruptly (directly) to the wheels (front wheels 10 and rear wheels 11), which may cause the vehicle to suddenly accelerate unintentionally. Also, if the accelerator lever 37 is operated after the PTO lever 39 is operated, the rotational power of the motor M may be transmitted abruptly (directly) to the working device, which may cause the working device to suddenly operate unintentionally.

[0045] An embodiment for suppressing such inappropriate driving and work will be described below.

[0046] [Embodiment 1] First, as a first embodiment, a configuration for suppressing inappropriate traveling and work by controlling the output of the motor M will be described with reference to FIGS. 3 and 4 and with reference to FIGS. 5 to 7. FIG.

[0047] The tractor according to the first embodiment performs predetermined motor suppression control to suppress inappropriate driving and work. The motor suppression control is controlled by the control unit 50. The control unit 50 is equipped with a processor such as a CPU or ECU, and operates under the control of the processor.

[0048] The control unit 50 is connected to operating devices such as the main shift lever 34, the sub-shift lever 35, the accelerator lever 37, the HST pedal 38, and the PTO lever 39, and controls the motor M and the hydrostatic continuously variable transmission 15 and transmission 16 according to the operating states of these operating devices. As described above, the motor M drives the wheels (front wheels 10 and rear wheels 11) and the PTO shafts (mid PTO shaft 17 and rear PTO shaft 18). The control unit 50 may also be connected to the notification unit 26, in which case the control unit 50 causes the notification unit 26 to issue a predetermined notification.

[0049] The control unit 50 includes an operation acquisition unit 52, a motor control unit 54, and a notification control unit 55 if the notification unit 26 is provided.

[0050] The operation acquisition unit 52 acquires information regarding operations performed on operating tools such as the main shift lever 34, the sub shift lever 35, the accelerator lever 37, the HST pedal 38, and the PTO lever 39. Specifically, the operation acquisition unit 52 acquires information such as the operating positions of the operating tools.

[0051] The motor control unit 54 controls the output of the motor M, such as the motor rotation speed and torque of the motor M, based on information regarding the operation performed on the operating tool acquired by the operation acquisition unit 52. Furthermore, when the accelerator operating tool, HST pedal 38, and PTO lever 39 are operated in an inappropriate procedure, the motor control unit 54 executes (implements) control to restrict an increase in the output of the motor M as predetermined motor suppression control. The notification control unit 55 causes the notification unit 26 to issue a predetermined notification, for example, to notify that motor suppression control is being executed.

[0052] In this configuration, when starting work travel with the motor M running, the main shift lever 34 and the sub shift lever 35 are first operated. Next, the accelerator lever 37 (accelerator operating device) is operated to adjust the motor rotation speed of the motor M. The appropriate procedure is to operate the accelerator lever 37 (accelerator operating device), and then operate the HST pedal 38 and PTO lever 39 (speed change operating device) to positions appropriate for work travel.

[0053] The following describes the process for performing motor suppression control when the operating devices are not operated appropriately. That is, the accelerator lever 37 (accelerator operating device) is not operated, and the HST pedal 38 and PTO lever 39 (gear change operating device) are operated to positions suitable for work driving (step #1 in FIG. 6).

[0054] Next, the motor control unit 54 determines whether the motor rotation speed is 0 (0 revolutions per minute (rpm)) (Step #2 in FIG. 6). That is, according to the appropriate procedure, the accelerator lever 37 (accelerator operation device) is operated, followed by the operation of the HST pedal 38 and the PTO lever 39 (speed change operation device). However, when the accelerator lever 37 (accelerator operation device) is not operated, it is checked whether at least one of the HST pedal 38 and the PTO lever 39 (speed change operation device) is operated. If the motor rotation speed is 0 (Step #2 in FIG. 6: Yes), it is further checked whether the accelerator lever 37 (accelerator operation device) has been operated (Step #3 in FIG. 6). In this way, the motor control unit 54 checks whether the accelerator lever 37 (accelerator operation device) has been operated (operated in an improper procedure) after the HST pedal 38 and the PTO lever 39 (speed change operation device) have been operated from a state in which the motor rotation speed is 0.

[0055] If the accelerator lever 37 (accelerator operating device) is operated after the HST pedal 38 and PTO lever 39 (gear change operating device) are operated (step #3 Yes in Figure 6), the motor control unit 54 performs motor suppression control to restrict the increase in motor rotation speed of the motor M so that the motor rotation speed does not increase from 0 rotations (step #4 in Figure 6).

[0056] 7 is a diagram illustrating rotation speed transitions, which are changes in motor rotation speed relative to the amount of operation of accelerator lever 37. When accelerator lever 37 (accelerator operation device) is operated, followed by operation of HST pedal 38 and PTO lever 39 (gear change operation device), and the operation devices are operated appropriately, the motor rotation speed changes in accordance with the amount of operation of accelerator lever 37, within an upper limit range according to the amount of operation of main shift lever 34 and sub shift lever 35, as shown in rotation speed transition LR0.

[0057] In contrast, when motor suppression control is being executed, the motor rotation speed remains at 0 rotations and does not change, even if the accelerator lever 37 is operated, as shown by rotation speed transition LC1.

[0058] As described above, with the motor suppression control of this embodiment, even if the accelerator lever 37 is operated, the motor rotation speed does not increase, the machine does not start moving, and the working device does not operate. As a result, sudden starts of the machine and sudden operation of the working device are suppressed, and the operator is encouraged to operate the operating tools in the appropriate procedure. Then, by repeating the operation in the appropriate procedure, the operator can start traveling or working appropriately.

[0059] If a predetermined release condition is satisfied while the motor suppression control is being executed (step #5 in FIG. 6), the motor control unit 54 ends the motor suppression control (step #6 in FIG. 6). The release condition is that the HST pedal 38 and the PTO lever 39 are turned off (returned to the neutral position). Note that the release condition may also be that the HST pedal 38 and the PTO lever 39 are turned off and the accelerator lever 37 is returned to the 0 rotation position.

[0060] By setting a release condition to terminate the motor suppression control, the machine returns to a state where it can accept operations to run the machine or operate the work equipment, and then by performing operations in the appropriate procedure, it is possible to start running or working appropriately.

[0061] Then, after the motor suppression control is terminated, or if the motor rotation speed is not 0 revolutions (0 revolutions per minute rpm) (step #2 No in FIG. 6), or if the accelerator lever 37 (accelerator operating device) is not operated after the HST pedal 38 and PTO lever 39 (speed change operating device) are operated (step #3 No in FIG. 6), the motor control unit 54 controls the motor M in accordance with the operation of the accelerator lever 37, HST pedal 38, PTO lever 39, etc., to start work driving (step #7 in FIG. 6).

[0062] [Another embodiment of embodiment 1] (1) The motor suppression control may be performed when the rotation speed of the motor M is equal to or less than a predetermined first rotation speed and an operating tool is operated in a predetermined (inappropriate) procedure, not just when the rotation speed is 0. Furthermore, the motor suppression control may be performed when the accelerator lever 37 (accelerator operating tool) is operated after the HST pedal 38 and PTO lever 39 (gear change operating tool) are operated, without checking whether the rotation speed of the motor M is equal to or less than the predetermined first rotation speed or 0.

[0063] This allows motor suppression control to be performed appropriately in situations where motor suppression control is necessary, preventing the machine from suddenly starting or the work equipment from suddenly operating, allowing the machine to start traveling or working appropriately.

[0064] (2) The motor suppression control is not limited to a configuration that does not increase the motor rotation speed, but may be a configuration that does not increase the torque of the motor M. Furthermore, the motor suppression control is not limited to a configuration that does not increase the motor rotation speed or the torque of the motor M, but may be an output restriction control that restricts an increase in the output of the motor M by any method.

[0065] With this configuration, it is possible to appropriately regulate (suppress) the increase in rotational power of the motor M transmitted to the wheels (front wheels 10 and rear wheels 11) and the working device depending on the situation. As a result, sudden acceleration of the machine body and sudden operation of the working device are suppressed, allowing the machine to start traveling or working appropriately.

[0066] (3) The motor suppression control is not limited to a configuration that prevents the motor rotation speed from increasing. It may also be configured to prevent the motor rotation speed from increasing above a predetermined idling rotation speed greater than zero, even when the accelerator lever 37 is operated. That is, as shown by the rotation speed transition LC2 in FIG. 7 , the motor control unit 54 controls the motor rotation speed so that it does not increase above the idling rotation speed even when the HST pedal 38 or PTO lever 39 (speed changer) is operated when the motor rotation speed is zero or very small (less than a predetermined first rotation speed). The idling rotation speed is a motor rotation speed at which the machine cannot start moving and the implement cannot perform work, or at which the machine travels only at an extremely low speed and the implement barely operates. Specifically, the idling rotation speed is between 300 and 900 revolutions per minute (rpm), e.g., 600 revolutions per minute (600 rpm), which is slightly lower than the motor rotation speed at which the machine actually begins to travel.

[0067] As a result, even when the accelerator lever 37 is operated, the motor rotation speed does not rise above the idling rotation speed. As a result, sudden starts of the machine and sudden operation of the work equipment are suppressed, allowing the machine to start traveling or work appropriately. Furthermore, when the motor M reaches the idling rotation speed, the operator can hear the rotation sound of the motor M and become aware that the motor M is operating. Therefore, the operator recognizes that the motor M is operating and can be conscious of starting the machine or operating the work equipment in the appropriate procedure. As a result, operations are performed in the appropriate procedure, sudden starts of the machine and sudden operation of the work equipment are suppressed, allowing the machine to start traveling or work appropriately.

[0068] (4) The motor suppression control is not limited to a configuration that does not increase the motor rotation speed. It may also be configured to control the motor rotation speed to a predetermined rotation speed within a range that prevents the vehicle from suddenly accelerating or the working device from suddenly operating when the accelerator lever 37 is not being operated. For example, as motor suppression control, when the accelerator lever 37 is not being operated, the motor rotation speed may be set to a predetermined second rotation speed that is greater than the first rotation speed, and when the accelerator lever 37 is operated, the motor rotation speed may be increased from the second rotation speed according to the amount of operation. The second rotation speed is a motor rotation speed that prevents the vehicle from starting and the working device from performing work, or a motor rotation speed that prevents the vehicle from traveling at an extremely low speed and the working device from operating at all. Specifically, the second rotation speed is between 300 and 900 revolutions per minute (rpm), for example, 600 revolutions per minute (600 rpm), which is slightly lower than the motor rotation speed at which the vehicle actually begins to travel. 7, when the HST pedal 38 or PTO lever 39 (speed change device) is operated while the motor rotation speed is 0 rotations or a small number of rotations (less than a predetermined first rotation speed), the motor control unit 54 increases the motor rotation speed to the second rotation speed regardless of the operating position of the accelerator lever 37. After that, when the accelerator lever 37 is operated, the motor rotation speed is changed from the second rotation speed in accordance with the operation of the accelerator lever 37.

[0069] As a result, the motor rotation speed is increased in advance when the HST pedal 38 or PTO lever 39 (speed change operating device) is operated, so a sudden increase in the motor rotation speed is suppressed even when the accelerator lever 37 (accelerator operating device) is operated. As a result, sudden acceleration of the machine and sudden operation of the working device are suppressed, allowing the machine to start traveling or work appropriately. Furthermore, by maintaining the motor M at the second rotation speed, the operator can be made aware that the motor M is operating by the rotation sound of the motor M. Therefore, the operator can recognize that the motor M is operating and be aware of the need to start the machine or operate the working device in the appropriate procedure. As a result, sudden acceleration of the machine and sudden operation of the working device are suppressed, allowing the machine to start traveling or work appropriately.

[0070] (5) Motor suppression control may be performed to increase the motor rotation speed at or below a predetermined acceleration. In other words, when the accelerator lever 37 (accelerator operation device) is operated after the HST pedal 38 or PTO lever 39 (speed change operation device) is operated, motor suppression control is performed to gradually increase the motor rotation speed at or below a predetermined acceleration. As a result, a sudden increase in the motor rotation speed is suppressed, and sudden acceleration of the machine or sudden operation of the work device is suppressed, allowing the machine to start traveling or work appropriately.

[0071] (6) The tractor may be configured without the notification unit 26. This allows the tractor to be configured with a simpler structure.

[0072] [Embodiment 2] Next, as a second embodiment, a configuration for suppressing inappropriate driving and work by notifying the user when the motor M is operating will be described using Figures 5, 7, and 8, with reference to Figures 3 and 4.

[0073] In order to prevent inappropriate driving and work, the tractor according to the second embodiment issues a notification that motor M is operating while motor M is operating. This notification allows the operator (worker / driver) to recognize that motor M is operating and to be aware of the need to drive the machine or operate the work implement in the appropriate procedure. As a result, operations are performed in the appropriate procedure, sudden acceleration of the machine or sudden operation of the work implement is prevented, and driving or work can be started appropriately.

[0074] In the tractor according to the second embodiment, when starting to travel for work while the motor M is running, the main speed change lever 34 and the sub-speed change lever 35 are first operated. Next, the accelerator lever 37 (accelerator operating device) is operated to adjust the motor rotation speed of the motor M. The appropriate procedure is to operate the accelerator lever 37 (accelerator operating device), and then operate at least one of the HST pedal 38 and the PTO lever 39 (speed change operating device) to a position suitable for traveling for work.

[0075] The following describes the control that the tractor performs when an improper operation is performed: the accelerator lever 37 (accelerator operation device) is not operated, and the HST pedal 38 and PTO lever 39 (gear change operation device) are operated to positions suitable for work travel (step #1 in FIG. 8).

[0076] Next, the motor control unit 54 determines whether the motor rotation speed is 0 rotations (0 rotations per minute (rpm)) (step #2 in FIG. 8). That is, according to the appropriate procedure, the accelerator lever 37 (accelerator operation device) is operated, and then the HST pedal 38 and the PTO lever 39 (speed change operation device) are operated. However, when the accelerator lever 37 (accelerator operation device) is not operated, it is confirmed whether at least one of the HST pedal 38 and the PTO lever 39 (speed change operation device) is not operated.

[0077] If the motor rotation number is 0 (Yes in step #2 in FIG. 8), the notification control unit 55 causes the notification unit 26 to issue a notification that the motor M is operating (step #3 in FIG. 8).

[0078] After that, the operator, recognizing that motor M is running, sets HST pedal 38 and PTO lever 39 (speed change operating devices) to the OFF position (neutral position), operates accelerator lever 37 (accelerator operating device), and then operates at least one of HST pedal 38 and PTO lever 39 (speed change operating device) (step #4 in FIG. 8). This then causes work travel to begin in accordance with the operation of the operating devices (step #5 in FIG. 8). Note that appropriate work travel is also performed when the motor rotation speed is not 0 rotations (0 revolutions per minute rpm) (the motor rotation speed is increasing) (step #2 No in FIG. 8).

[0079] This configuration allows the operator (worker / driver) to recognize that the motor M is operating and to be aware of the need to run the machine or operate the work equipment in the appropriate procedure. As a result, operations are performed in the appropriate procedure, preventing the machine from suddenly starting or the work equipment from suddenly operating, allowing the machine to start running or working in the appropriate manner.

[0080] [Another embodiment of embodiment 2] (1) After at least one of the HST pedal 38 and the PTO lever 39 (shift operating device) is operated, a notification that the motor M is operating may be made when the rotation speed of the motor M is equal to or lower than a predetermined first rotation speed, not just when the rotation speed is 0 rotations.

[0081] This allows the operator to be properly notified in situations where the operator should be aware that the motor M is operating, allowing the operator to accurately recognize that the motor M is operating. As a result, by the operator performing operations in the appropriate procedure, sudden acceleration of the machine and sudden operation of the work device are suppressed, allowing the machine to start traveling or work appropriately.

[0082] (2) The notification is not limited to a configuration in which a notification is given when the motor rotation speed is 0 (the first rotation speed or less) when at least one of the HST pedal 38 and the PTO lever 39 is operated. After the motor M is started, while the motor rotation speed is 0 or the first rotation speed or less, the notification control unit 55 may cause the notification unit 26 to issue a notification that the motor M is operating. In this case, when the accelerator lever 37 (accelerator operating device) is operated, the notification control unit 55 may end the notification.

[0083] This more accurately prevents the HST pedal 38 and / or the PTO lever 39 (gear change operating device) from being operated when the accelerator lever 37 (accelerator operating device) is not being operated. As a result, if the operator performs the operations in the appropriate procedure, sudden acceleration of the machine and sudden operation of the work device are prevented, allowing the machine to start traveling or work appropriately.

[0084] (3) In addition to or separately from each of the above embodiments, when the motor M is operating, the tractor may maintain the motor rotation speed at or above an idling rotation speed, which is a predetermined rotation speed greater than 0 rotations. The motor sound of the motor M operating at the idling rotation speed allows the operator to recognize that the motor M is operating. As a result, by the operator performing operations in the appropriate procedure, sudden acceleration of the machine body and sudden operation of the work implement can be suppressed, and traveling or work can be started appropriately.

[0085] (4) When the motor suppression control in the first embodiment is executed, the notification control unit 55 may cause the notification unit 26 to notify at least one of the fact that the motor suppression control is being executed and that the motor M is operating. This allows the operator to more accurately recognize that the motor M is operating. As a result, if the operator performs operations in an appropriate procedure, sudden acceleration of the machine and sudden operation of the work device are suppressed, and traveling or work can be started appropriately.

[0086] [Another embodiment] (1) In each of the above embodiments, the gearshift operating devices are not limited to the HST pedal 38 and the PTO lever 39, but may be any operating devices for operating a gearshift of rotational power, or any combination thereof. Furthermore, the accelerator operating devices are not limited to the accelerator lever 37, but may be any operating devices for increasing or decreasing the motor rotation speed of the motor M, or any combination thereof. When at least one of the gearshift operating devices and at least one of the accelerator operating devices is operated in an improper order, at least one of motor suppression control and a predetermined notification is executed.

[0087] This allows at least one of motor suppression control and a predetermined notification to be performed depending on the configuration of the tractor, allowing the tractor to start traveling or work appropriately.

[0088] (2) In each of the above embodiments, the notification unit 26 may be any device capable of notifying the operator. For example, the notification unit 26 may be a speaker or voice alarm generator capable of issuing a voice or warning sound, an LED, lamp, or warning light capable of notifying the operator using a lighting or flashing pattern, a monitor or information terminal capable of displaying text or images, or a combination of these. This allows for notifications that are easy for the operator to check depending on the situation.

[0089] (3) In each of the above embodiments, the traveling device is not limited to wheels and may be a crawler.

[0090] (4) In each of the above embodiments, the control unit 50 is not limited to being configured with the above-described functional blocks, but may be configured with any functional blocks. For example, each functional block of the control unit 50 may be further subdivided, or conversely, some or all of the functional blocks may be combined. Furthermore, the functions of the control unit 50 are not limited to the above-described functional blocks, and may be realized by a method executed by any functional block. Furthermore, some or all of the functions of the control unit 50 may be configured with software. A program related to the software is stored in any storage device and executed by a processor such as a CPU included in the control unit 50 or a separately provided processor. [Industrial Applicability]

[0091] The present invention can be applied to electric agricultural vehicles such as tractors, harvesters, and rice transplanters, as well as various electric work vehicles that travel electrically to perform various tasks. [Explanation of symbols]

[0092] 10 Front wheels (running gear) 11 Rear wheels (running gear) 15 Hydrostatic continuously variable transmission 26. Information Department 37 Accelerator lever (accelerator operating device) 38 HST pedal (HST operating device / gear shift operating device) 39 PTO lever (PTO operating device / speed change operating device) 54 Motor control unit Medium motor

Claims

1. a motor that drives at least one of the traveling device and the working device; a speed change operating device that changes the speed of rotational power that drives the traveling device or the working device; an accelerator operation tool for increasing or decreasing the motor rotation speed of the motor; a motor control unit that controls the motor rotation speed in response to an operation of the accelerator operation tool, When the electric work vehicle is stopped while the motor is running and it is detected that the accelerator operating device has been operated after the gear change operating device has been operated, the operation is detected as an inappropriate operation that could lead to a sudden start of the vehicle, and motor suppression control is performed to suppress an increase in motor output.

2. An electric work vehicle as described in claim 1, wherein a predetermined alert to avoid the inappropriate operation is given when the motor rotation speed is 0 rotations or less than a predetermined first rotation speed after the speed change operating device is operated.

3. the motor control unit, when the speed change device is operated while the motor rotation speed is equal to or less than the first rotation speed, sets the motor rotation speed to equal to or less than a second rotation speed that is greater than the first rotation speed and at which a predetermined vehicle does not take off, 3. The electric work vehicle according to claim 2, wherein the notification is made by the rotation sound of the motor.

4. the motor control unit controls the motor rotation speed so as not to exceed an idling rotation speed, which is a predetermined rotation speed greater than 0 rotations, while the motor is operating; 3. The electric work vehicle according to claim 2, wherein the notification is made by the rotation sound of the motor.

5. The electric work vehicle according to claim 2 , further comprising a notification unit that issues the notification.

6. 6. The electric work vehicle according to claim 5, wherein the notification unit is a speaker that emits a warning sound, and the notification is made by the warning sound.

7. 6. The electric work vehicle according to claim 5, wherein the notification unit is a warning light, and the notification is made by lighting or flashing the warning light.

8. The motor further includes a hydrostatic continuously variable transmission that changes the speed of the rotational power transmitted to the traveling device, 2. The electric work vehicle according to claim 1, wherein the speed change operating device includes an HST operating device that operates the angle of a swash plate of the hydrostatic continuously variable transmission.

9. The electric work vehicle according to claim 1, wherein the speed change device includes a PTO device that changes the speed of the rotational power transmitted from the motor to the work device.

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