electric work vehicle

Abstract

To make it possible to satisfactorily perform safety management of a vehicle body while charging is performed.SOLUTION: An electric work vehicle includes: an electric motor M capable of driving a vehicle body for traveling; a battery 4 which supplies electric power for driving to the electric motor M, and which can be charged by an external power supply device KD; a connection part 37 to which a power supply connector 36 on the power supply device side can be connected; a control device 34 which controls operation of the electric motor M, and which controls a state of charging by the power supply device KD; and a switching operation part 44 which receives an operation command for switching the control device 34 to an operation enabled state or a non-operation state, and which can switch a state of the control device 34. During operation for charging the battery 4 by the power supply device KD, when the switching operation part 44 receives the operation command for switching the control device 34 to the non-operation state, the charging by the power supply device KD is continuously performed. When the charging is completed, the control device 34 is switched to the non-operation state.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electric work vehicle that is configured to perform, for example, ground work or other tasks while the vehicle body is traveling, and that is equipped with an electric motor that can drive the vehicle body to travel, and a battery that supplies driving power to the electric motor. [Background technology]

[0002] In this type of electric work vehicle, when the battery power is consumed, it is charged from an external power supply device connected via a connector, as described in Patent Document 1, for example. During charging, no special control is performed on the vehicle body side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-957 Summary of the Invention [Problem to be solved by the invention]

[0004] Charging the battery may take a long time. As a result, while charging is in progress, it is possible that the driver may forget that charging is in progress and mistakenly sit in the driver's seat of the vehicle and operate the vehicle. It is also possible that someone else may operate the vehicle when the driver leaves the vehicle. This could cause the vehicle to move unexpectedly, potentially damaging the vehicle or the power supply device. Therefore, safety management of the vehicle while charging is insufficient.

[0005] Therefore, there is a need to ensure that the safety of the vehicle body can be properly managed while charging. [Means for solving the problem]

[0006] The characteristic configuration of the electric work vehicle according to the present invention is that it comprises an electric motor capable of driving the vehicle body, a battery that supplies driving power to the electric motor and can be charged by an external power supply device, a connection part to which a power supply connector on the power supply device side can be connected, a control device that controls the operation of the electric motor and controls the charging state by the power supply device, and a switching operation part that can switch the state of the control device by receiving an operation command to switch the control device between an operable state and an inoperative state, and When the vehicle body is prohibited from moving and the control device is in the operable state where it can be charged, In the above, when the switching operation unit receives an operation command to switch the control device to a non-operating state, the charging by the power supply device is continued, and when the charging is completed, the control device is switched to a non-operating state. 。 Another characteristic feature of the electric work vehicle of the present invention is that it comprises an electric motor capable of driving the vehicle body to travel, a battery that supplies driving power to the electric motor and is chargeable by an external power supply device, a connection part to which a power supply connector on the power supply device can be connected, a control device that controls the operation of the electric motor and controls the charging state by the power supply device, a switching operation part that accepts an operation command to switch the control device between an operable state and an inoperative state and can switch the state of the control device, and an operation key that can be inserted and attached to the switching operation part, and the control device is configured to prohibit movement of the vehicle body during charging operation after charging of the battery by the power supply device has started with the power supply connector connected to the connection part, and if the operation key is switched to a state where it is removed from the switching operation part while charging of the battery by the power supply device is in progress, charging by the power supply device will continue. Another characteristic feature of the electric work vehicle according to the present invention is that it comprises an electric motor capable of driving the vehicle body to travel, a battery that supplies driving power to the electric motor and is chargeable by an external power supply device, a connection part to which a power supply connector on the power supply device can be connected, a control device that controls the operation of the electric motor and controls the charging state by the power supply device, a switching operation part that receives an operation command to switch the control device between an operable state and an inoperative state and is able to switch the state of the control device, and an operation key that is capable of wireless communication with a receiving part provided on the vehicle body side, and the control device is configured to prohibit the vehicle body from moving during charging operation after charging of the battery by the power supply device has started with the power supply connector connected to the connection part, and if, during charging of the battery by the power supply device, the operation key is switched to a state where it is located farther than the communication distance with the vehicle body, charging by the power supply device continues.

[0007] According to the present invention, the vehicle is prohibited from moving during charging from the start to the completion of charging. As a result, when charging takes a long time, even if the driver accidentally sits in the driver's seat of the vehicle and operates the vehicle, or if someone else operates the vehicle, disadvantages such as damage to the vehicle or the power supply device due to the vehicle moving can be avoided.

[0008] Therefore, it is possible to ensure the safety of the vehicle body during charging.

[0009] In the present invention, it is preferable that the control device is configured not to drive the electric motor during the charging operation.

[0010] According to this configuration, the electric motor is not driven during charging, so the vehicle body does not move or travel by the power of the electric motor. If the vehicle body is equipped with a working device, the working device is not driven by the electric motor. Therefore, the electric motor, which is the power source, cannot be driven, ensuring safety.

[0011] In the present invention, the power from the battery is supplied to the electric motor via an inverter, and the control device is configured to stop output to the inverter during the charging operation so as not to drive the electric motor.

[0012] According to this configuration, by stopping the output to the inverter, the operation of the electric motor can be reliably restrained.

[0013]

[0014]

[0015]

[0016]

[0017] [Brief explanation of the drawings]

[0018] [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] FIG. 2 is a block diagram showing a configuration for charging. [Figure 5] 10 is a flowchart of a control operation. [Figure 6] FIG. 10 is a diagram showing a flow of power transmission in another embodiment. [Figure 7] FIG. 10 is a block diagram showing a configuration for charging according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] 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 defined as "front," the direction of arrow B as "rear," the direction of arrow L as "left," and the direction of arrow R as "right." The direction of arrow U in the drawings will be defined as "up," and the direction of arrow D as "down."

[0020] [Overall configuration of the tractor] The following describes a tractor as an example of an electric work vehicle according to the present invention. As shown in Figure 1, the tractor is equipped with left and right front wheels 10 and left and right rear wheels 11 as vehicle body travel devices, and a cover member 12.

[0021] The tractor includes a machine frame 2 and a driving section 3. The machine frame 2 is supported by left and right front wheels 10 and left and right rear wheels 11.

[0022] 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.

[0023] The driver's section 3 has a protective frame 30, a driver's seat 31, and a steering wheel 32. An operator can sit in the driver's seat 31. This allows the operator to get into the driver's 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 driver's section 3.

[0024] The tractor is equipped with a traveling battery 4. The cover member 12 is configured to be swingable about an opening / closing axis Q that extends along 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 traveling battery 4 is covered by the cover member 12.

[0025] As shown in Fig. 2, the tractor is equipped with an inverter 14 and an electric motor M. 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 electric motor M. The electric motor M is then driven by the AC power supplied from the inverter 14.

[0026] 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.

[0027] The hydraulic pump 15a is driven by rotational power from the electric 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 configured so that the gear ratio can be changed continuously.

[0028] The rotational power output from the hydraulic motor 15 b 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.

[0029] 2 and 3, the tractor is equipped with a mid PTO shaft 17 and a rear PTO shaft 18. Rotational power output from the electric 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.

[0030] If a working device is connected to the mid PTO shaft 17 or the rear PTO shaft 18, the working device is 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 grass cutting device 19 is connected to the mid-PTO shaft 17. The grass cutting device 19 is driven by the rotational power of the mid-PTO shaft 17.

[0031] [Configuration related to control of electric motor] As shown in FIG. 4, the configuration related to the control of the electric motor M includes an accelerator device 33, a control device 34 that controls the operation of the electric motor M, and the inverter 14. The accelerator device 33 is provided near the steering wheel 32. Although not shown, the accelerator device 33 includes a lever that can be swung and a potentiometer that is operated by swung operation of the lever. The accelerator device 33 is connected to the control device 34. The control device 34 is connected to the inverter 14 via a signal harness 35. The control device 34 is configured to issue commands to the inverter 14 in response to commands from the accelerator device 33. The inverter 14 is configured to adjust the power supplied from the traction battery 4 to the electric motor M to control the output of the electric motor M in response to commands from the control device 34.

[0032] [Configuration related to charging] As shown in FIG. 4, the driving battery 4 can be charged by an external power supply device KD. The tractor is provided with a charging connection part 37 to which a power supply connector 36 on the power supply device KD side can be connected. The charging connection part 37 is provided inside the cover member 12 and is exposed to the outside when the cover member 12 is swung open. The control device 34 controls the operation of the electric motor M and also controls the charging state by the power supply device KD.

[0033] The charging connection part 37 complies with commonly used standards. With the power feeding connector 36 on the power feeding device KD side connected to the charging connection part 37, the running battery 4 is charged via a power supply line 39. The running battery 4 supplies high-voltage power (for example, several tens to several hundreds of volts) to the running electric motor M via the power supply line 39.

[0034] The traction battery 4 is constructed using, for example, a lithium-ion battery, and although not shown, is made up of a large number of stacked, small, low-voltage unit cells (cells), which are enclosed in a sealed storage case. As a result, heat tends to build up inside the battery, and once the internal temperature rises, it is difficult to lower it. To prevent this, the traction battery 4 is equipped with a temperature sensor 40 as a temperature detection means for detecting the internal temperature. Information detected by the temperature sensor 40 is input to the control device 34.

[0035] In addition to the traction battery 4, the tractor is equipped with an electrical equipment battery 41 that supplies power to the control device 34 and other electrical equipment. The electrical equipment battery 41 supplies low-voltage (12 volts) power to drive the electrical equipment. The electrical equipment battery 41 is charged with power supplied from the traction battery 4 via a DC / DC converter 42.

[0036] The driving unit 3 is provided with a switching operation unit 44 as a start command means capable of switching the control device 34 between an operable state and an inoperative state. The switching operation unit 44 has an insertion portion 46 as an attachment portion into which a portable operation key 45 can be inserted and attached, and a push-button type switch 47 that can be manually pressed. With the operation key 45 inserted and attached in the insertion portion 46, pressing the switch 47 switches the control device 34 from an inoperative state to an operable state.

[0037] The operation panel 43 is provided with a meter panel 48 that displays, for example, the vehicle's running state, working state, battery information (charge level and temperature), etc. The meter panel 48 is connected to the control device 34, and its operation is controlled by the control device 34.

[0038] The control device 34, inverter 14, traction battery 4, DC / DC converter 42, meter panel 48, charging connection unit 37, etc. are connected to each other via a CAN (Controller Area Network) signal harness 35 so as to be able to communicate data. The control device 34 communicates with the charging connection unit 37 via a charging communication harness 49, and information such as whether the power feeding connector 36 is connected to the charging connection unit 37 and information about the charging current required on the work vehicle side is transmitted. Signals are also configured to be able to communicate between the charging connection unit 37 and the power feeding device KD. Operation information from a switching operation unit 44 is also input to the control device 34.

[0039] [Charging control] When the control device 34 is switched to an operable state while the power supply connector 36 is connected to the charging connection part 37, the control device 34 switches to a charging mode. In the charging mode, the control device 34 is configured to charge the driving battery 4 using the power supply device KD.

[0040] The control device 34 is configured to prohibit the vehicle body from moving during the charging operation from when the power supply device KD starts charging the driving battery 4 with the power supply connector 36 connected to the charging connection part 37 until charging of the driving battery 4 is completed. Specifically, the control device 34 is configured not to drive the electric motor M during the charging operation.

[0041] The control device 34 is configured to continue charging by the power supply device KD after starting charging by the power supply device KD even if the operation key 45 is switched to a state where it is removed from the insertion portion 46. Furthermore, if charging by the power supply device KD continues after the operation key 45 is switched to a state where it is removed from the insertion portion 46, the control device 34 is configured to automatically switch to a non-operating state when charging is completed.

[0042] Hereinafter, specific charging control by the control device 34 will be described with reference to the flowchart of FIG.

[0043] When charging the traveling battery 4, the operator connects the power supply connector 36 of the power supply device KD to the charging connection portion 37. Next, in the switching operation unit 44 provided on the operation panel 43 of the driving unit 3, the operator inserts and attaches the operation key 45 into the insertion portion 46 and presses the switch 47. When the control device 34 recognizes this, it switches to the charging mode (steps #1, #2, #3).

[0044] When the mode is switched to the charging mode, the output of the inverter 14 is stopped to inhibit the operation of the electric motor M (step #4). Next, necessary information is sent to the power supply device KD via the charging communication harness 49 to start supplying power, and charging of the driving battery 4 by the power supply device KD is started (step #5).

[0045] The driving battery 4 is charged up to a preset charge state, and when it is fully charged, charging is stopped (steps #6 and #7).

[0046] When charging is completed, it is determined whether or not the operation key 45 is inserted into the insertion portion 46 (step #8). If it is determined that the operation key 45 has been removed and is not attached at that time, it is assumed that the driver removed the operation key 45 while charging was in progress, and therefore the control device 34 is switched to a non-operating state to forcibly cut off the power supply (step #09).

[0047] Therefore, if charging continues using the power supply device KD after the operation key 45 is switched to a state where it is removed from the insertion portion 46, the control device 34 will automatically switch to a non-operating state when charging is completed.

[0048] If the operation key 45 is inserted when charging is completed, the operator removes the power supply connector 36 of the power supply device KD to disconnect it from the charging connection part 37, and then presses the switch 47 to cancel the charging mode (steps #08, #10, #11). At this time, the output of the inverter 14 is restarted to enable the electric motor M to operate, and the inhibited state of operation of the electric motor M is released (step #12). Therefore, while the driving battery 4 is being charged, the electric motor M will not be operated even if an operation to run the vehicle is performed, and the vehicle is prohibited from moving or running.

[0049] [Another embodiment] (1) In the above embodiment, the control device 34 does not drive the electric motor M during charging operation. However, instead of this configuration, the following configuration may be used.

[0050] As shown in Fig. 6, a traveling clutch 50 capable of connecting and disconnecting power is provided in a transmission path that transmits the power of the electric motor M to the hydrostatic continuously variable transmission 15, a first work clutch 51 capable of connecting and disconnecting power is provided in a transmission path that transmits the power of the electric motor M to the mid PTO shaft 17, and a second work clutch 52 capable of connecting and disconnecting power is provided in a transmission path that transmits the power of the electric motor M to the rear PTO shaft 18. Then, as shown in Fig. 7, a control device 34 is configured to control the operation of each of the traveling clutch 50, the first work clutch 51, and the second work clutch 52.

[0051] When using the hydrostatic continuously variable transmission 15, a traveling stop state can be realized by the neutral position, so generally no clutch is provided. However, in this embodiment, the traveling clutch 50 is provided, and the control device 34 normally sets the traveling clutch 50 to the engaged state, and during charging operation, even if a command to engage the traveling clutch 50 is issued, the control device 34 maintains the traveling clutch 50 in the disengaged state and does not switch to the clutch engaged state, thereby prohibiting movement of the vehicle body.

[0052] At this time, if either the first work clutch 51 or the second work clutch 52 is maintained in an engaged state, the work device can be driven while the vehicle body is stationary. Also, during charging work, the first work clutch 51 and the second work clutch 52 may each be maintained in a disengaged state.

[0053] Instead of this configuration, a configuration may be adopted in which only one of the first work clutch 51 and the second work clutch 52 is provided, or a configuration may be adopted in which neither work clutch is provided.

[0054] (2) In the above embodiment, the operation key 45 is configured to be able to be inserted into the insertion portion 46. However, instead of this configuration, the operation key 45 may be configured to be capable of wireless communication with a receiving portion on the vehicle body, and when the switch 47 is operated while the operation key 45 is close to the vehicle body, the control device 34 may be switched to an operable state.

[0055] (3) In the above embodiment, the control device 34 is configured to switch to the charging mode when the power supply connector 36 is connected to the charging connection portion 37 and the control device 34 is switched to an operable state. However, instead of this configuration, the control device 34 may be configured to switch to the charging mode when the power supply connector 36 is connected to the charging connection portion 37 after the control device 34 has been switched to an operable state in advance. [Industrial Applicability]

[0056] The present invention is not limited to tractors, but can also be applied to various electric work vehicles such as rice transplanters, combine harvesters, and construction machinery. [Explanation of symbols]

[0057] 4 Battery 36 Power supply connector 37 Connection 50 Running clutch 51 First working clutch 52 Second working clutch KD Power Supply Device M Electric motor

Claims

1. an electric motor capable of driving the vehicle body; a battery that supplies driving power to the electric motor and is chargeable by an external power supply device; a connection portion to which a power supply connector of the power supply device can be connected; a control device that controls the operation of the electric motor and controls a charging state of the power supply device; a switching operation unit that can switch the state of the control device by receiving an operation command for switching the control device between an operable state and an inoperative state, When the vehicle body is prohibited from moving due to the power supply device charging the battery and the control device is in the operable state where charging is possible, if the switching operation unit receives an operation command to switch the control device to a non-operating state, charging by the power supply device continues, and when charging is completed, the control device is switched to a non-operating state.

2. an electric motor capable of driving the vehicle body; a battery that supplies driving power to the electric motor and is chargeable by an external power supply device; a connection portion to which a power supply connector of the power supply device can be connected; a control device that controls the operation of the electric motor and controls a charging state of the power supply device; a switching operation unit that receives an operation command for switching the control device between an operable state and an inoperative state and switches the state of the control device; an operation key that can be inserted and attached to the switching operation unit; the control device is configured to prohibit movement and running of the vehicle body during a charging operation after the power feeding device starts charging the battery with the power feeding connector connected to the connection portion, When the operation key is switched to a removed state from the switching operation unit while the battery is being charged by the power supply device, the electric work vehicle continues charging by the power supply device.

3. an electric motor capable of driving the vehicle body; a battery that supplies driving power to the electric motor and is chargeable by an external power supply device; a connection portion to which a power supply connector of the power supply device can be connected; a control device that controls the operation of the electric motor and controls a charging state of the power supply device; a switching operation unit that receives an operation command for switching the control device between an operable state and an inoperative state and switches the state of the control device; an operation key capable of wireless communication with a receiver provided on the vehicle body side; the control device is configured to prohibit movement and running of the vehicle body during a charging operation after the power feeding device starts charging the battery with the power feeding connector connected to the connection portion, An electric work vehicle in which, if the operation key is switched to a state where it is located farther than the communication distance with the vehicle body while the battery is being charged by the power supply device, charging by the power supply device continues.

4. 4. The electric work vehicle according to claim 2, wherein charging by the power supply device is continued, and when charging is completed, the control device is switched to a non-operating state.

5. 5. The electric work vehicle according to claim 1, wherein the control device is configured not to drive the electric motor during the charging operation.

6. The power supply system is configured to supply power from the battery to the electric motor via an inverter, 6. The electric work vehicle according to claim 5, wherein the control device is configured to stop output to the inverter during the charging operation so as not to drive the electric motor.

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