Electric tractor

Abstract

This electric tractor comprises: a battery (10); a motor driven by power supplied from the battery (10); a travel device driven by the motor; and a support mechanism (W) having a first support part (S1) and a second support part (S2). The first support part (S1) supports the battery (10), and the second support part (S2) supports an electrical component (N).

Description

electric tractor

[0001] The present invention relates to an electric tractor.

[0002] [1] The work vehicle described in Patent Document 1 (referred to as a "tractor" in Patent Document 1) is equipped with an engine and a traveling device (referred to as "front wheels" and "rear wheels" in Patent Document 1) driven by the engine. The engine is housed in a bonnet (referred to as an "engine bonnet" in Patent Document 1).

[0003] [2] For example, the electric tractor disclosed in JP 2014-143965 A (Patent Document 2) is equipped with a battery, a first electric motor for propulsion (referred to in the document as a “propulsion system electric motor (7)”), and a second electric motor for at least one of work and hydraulic drive (referred to in the document as an “electric motor (6)”).

[0004] Japanese Patent Application Publication No. 2018-69926 Japanese Patent Application Publication No. 2014-143965

[0005] [1] The problem associated with Background Art [1] is as follows: In the work vehicle described in Patent Document 1, a battery and a motor may be provided instead of the engine. This allows the vehicle to travel without emitting exhaust gas.

[0006] Furthermore, in this configuration, a configuration in which the battery and electrical components (for example, a voltage converter) are disposed inside the hood is conceivable.

[0007] However, in this case, it is often necessary to place components for supporting the battery and the electrical equipment inside the hood, which makes it difficult to install a relatively large battery, and therefore the capacity of the battery that can be installed tends to be relatively small.

[0008] SUMMARY OF THE INVENTION An object of the present invention is to provide an electric tractor equipped with a battery having a relatively large capacity.

[0009] [2] Another problem corresponding to Background Art [1] is as follows: In the work vehicle described in Patent Document 1, a battery and a motor may be provided instead of the engine. This allows the vehicle to travel without emitting exhaust gas.

[0010] Furthermore, in this configuration, it is conceivable to mount various electrical components (for example, a voltage converter), but Patent Document 1 does not describe the arrangement of the electrical components.

[0011] An object of the present invention is to provide an electric tractor in which a plurality of electrical components are suitably arranged.

[0012] [3] The problem associated with Background Art [2] is as follows: When an electric tractor is configured to have multiple electric motors, a distribution unit for distributing power from the battery is required, but the challenge is how to position the distribution unit without creating unnecessary wiring in order to efficiently supply power from the battery to the electric motors.

[0013] An object of the present invention is to provide an electric tractor that can efficiently distribute electric power from a battery to a plurality of electric motors.

[0014] [1] The solution to problem [1] is as follows: The present invention is characterized in that it comprises a battery, a motor driven by power supplied from the battery, a traveling device driven by the motor, and a support mechanism having a first support part and a second support part, wherein the first support part supports the battery and the second support part supports electrical equipment.

[0015] According to this configuration, the support mechanism supports the battery. Furthermore, the support mechanism also supports the electrical components. This makes it easier to secure a larger space for the battery compared to when a mechanism for supporting the battery and a mechanism for supporting the electrical components are separately provided. As a result, a relatively large battery can be installed.

[0016] That is, with this configuration, an electric tractor equipped with a battery having a relatively large capacity can be realized.

[0017] Furthermore, in the present invention, it is preferable that the support mechanism has left and right support frames, each of which is arranged in a position that follows the side walls of the battery, and the battery is arranged in a position sandwiched between the left and right support frames.

[0018] According to this configuration, the left and right support frames of the support mechanism protect the sides of the battery. This makes it possible to protect the sides of the battery without providing a dedicated member for protecting the sides of the battery. This makes it easy to suppress increases in manufacturing costs.

[0019] Furthermore, in the present invention, it is preferable that a plurality of the batteries are provided, and the first support portion supports the plurality of batteries.

[0020] According to this configuration, multiple batteries are supported by the support mechanism. This makes it easier to secure a larger space for arranging the batteries than when multiple mechanisms are provided corresponding to the number of batteries and the multiple batteries are supported by the multiple mechanisms. As a result, relatively large batteries can be installed.

[0021] Furthermore, in the present invention, it is preferable that the plurality of batteries are arranged in a vertical direction.

[0022] With this configuration, the width of the vehicle body is smaller than when multiple batteries are lined up in the left-right direction. Also, with this configuration, the width of the vehicle body is smaller than when multiple batteries are lined up in the front-rear direction. This makes it possible to realize an electric tractor with a relatively small width of the vehicle body and a relatively small front-rear width.

[0023] Furthermore, in the present invention, it is preferable that there be gaps between the plurality of batteries.

[0024] With this configuration, air is present between the multiple batteries. The batteries are effectively cooled by the air flowing between them due to, for example, wind generated by running or a fan. This makes it possible to realize an electric tractor in which the batteries are effectively cooled.

[0025] [2] The solution to problem [2] is as follows: The present invention is characterized in that it includes a first battery, a motor driven by power supplied from the first battery, a driving device driven by the motor, and a plurality of electrical components, the plurality of electrical components being allocated to the left and right of the first battery.

[0026] According to this configuration, the multiple electrical components are distributed to the left and right of the first battery, which improves the weight balance in the left-right direction of the vehicle body compared to when the multiple electrical components are concentrated to the left or right of the first battery.

[0027] Furthermore, compared to when the electrical components are concentrated above the first battery, the electrical components are likely to be positioned lower, which lowers the center of gravity of the vehicle body and improves the stability of the vehicle body.

[0028] Furthermore, the electrical components are more likely to be positioned higher than when they are concentrated below the first battery, which makes it less likely for muddy water and the like from the ground to adhere to the electrical components.

[0029] That is, with this configuration, it is possible to realize an electric tractor in which a plurality of electrical components are suitably arranged.

[0030] Furthermore, in the present invention, the plurality of electrical components include a second battery for auxiliary equipment, a voltage converter that reduces the voltage of the power from the first battery and supplies it to the second battery, and a junction box, and it is preferable that the voltage converter and the junction box are arranged to the left and right of the first battery.

[0031] With this configuration, the weight balance in the left-right direction of the aircraft is more likely to be good than when the voltage converter and junction box are concentrated to the left or right of the first battery.

[0032] Furthermore, in the present invention, it is preferable that two first batteries are provided, the two first batteries are arranged in a vertical direction, and the voltage converter and the junction box are both arranged below the lower end position of the upper first battery.

[0033] With this configuration, the voltage converter and the junction box are positioned relatively low, which lowers the center of gravity of the aircraft, improving the stability of the aircraft.

[0034] Furthermore, in the present invention, it is preferable that the vehicle is provided with a first cooling path and a second cooling path through which a coolant circulates, the first cooling path and the second cooling path being independent of each other, the first cooling path including the voltage converter, the second cooling path including the first battery, at least a portion of the first cooling path passing through one of the left and right sides of the first battery, and at least a portion of the second cooling path passing through the other of the left and right sides of the first battery.

[0035] With this configuration, the weight balance in the left-right direction of the aircraft is more likely to be good compared to when both the first cooling path and the second cooling path pass through one side of the first battery, or when both the first cooling path and the second cooling path pass through the other side of the first battery.

[0036] Furthermore, in the present invention, it is preferable that two first batteries are provided, the two first batteries are arranged in a vertical direction, and the plurality of electrical components are arranged in a vertically distributed manner relative to the lower end position of the upper first battery.

[0037] This configuration makes it easy to arrange the electrical components above and below the lower end of the upper first battery so that they overlap each other in a plan view. This reduces the space required for arranging the multiple electrical components in a plan view. As a result, it is easy to realize an electric tractor that is compact in size in a plan view.

[0038] [3] The solution to problem [3] is as follows: The electric tractor of the present invention includes a battery that stores electric power, a first electric motor for traveling that receives electric power from the battery, a second electric motor for at least one of working and hydraulic driving that receives electric power from the battery, and a distribution unit that distributes electric power from the battery to each of the first electric motor and the second electric motor, and is characterized in that the distribution unit is disposed adjacent to a side portion of the battery that extends vertically.

[0039] According to the present invention, the distribution unit is disposed adjacent to a side portion of the battery. The side portion of the battery is more easily accessible to workers than the upper or lower portion of the battery. By disposing the distribution unit on this side portion, for example, an assembly worker can easily connect the wiring between the battery, the first electric motor, and the second electric motor. Furthermore, by disposing the distribution unit adjacent to the side portion of the battery, it is possible to minimize the wiring distance between the battery and the distribution unit. This makes it possible to avoid wasted wiring in terms of both structure and assembly man-hours. In other words, the present invention realizes an electric tractor that can efficiently distribute power from a battery to multiple electric motors.

[0040] In the present invention, it is preferable that a cover member is provided which has a swinging part that swings open and closed and a fixed part that is fixed below the swinging part, and which covers the battery, and that a porous mesh part is formed in the fixed part, and that the distribution unit is arranged adjacent to the mesh part.

[0041] With this configuration, the distribution unit is covered by the cover member. As a result, when the swinging part is closed, the battery and distribution unit are less likely to come into contact with foreign objects. Furthermore, since the fixed part has a porous mesh part, the entry of foreign objects into the internal space of the cover member is suppressed, while heat in the internal space is released to the outside through the mesh part. Furthermore, the configuration in which the distribution unit is adjacent to the mesh part promotes heat dissipation from the distribution unit.

[0042] In the present invention, the distribution unit is provided with a first electrical connection port for connecting the electrical cable on the battery side, a second electrical connection port for connecting the electrical cable on the first electric motor side, and a third electrical connection port for connecting the electrical cable on the second electric motor side, and it is preferable that the first electric motor and the second electric motor are shifted toward the rear of the aircraft relative to the battery, the first electrical connection port is located at the front of the distribution unit, and the second electrical connection port and the third electrical connection port are located at the rear of the distribution unit.

[0043] With this configuration, the first electrical connection port connected to the battery and the two electrical connection ports (the second and third electrical connection ports) connected to the electric motors are distributed between the front and rear of the distribution unit. This allows the distribution unit case to be more compact than when the first, second, and third electrical connection ports are concentrated at the front or rear of the distribution unit. Furthermore, with this configuration, the electrical cable extending from the second electrical connection port to the first electric motor and the electrical cable extending from the third electrical connection port to the second electric motor are routed as linearly as possible along the front-to-rear direction. This further simplifies the electrical cable routing configuration, enabling more efficient distribution of power from the battery to multiple electric motors.

[0044] In the present invention, it is preferable that a charging socket is provided for receiving power for charging the battery, and that the distribution unit is provided with a fourth current connection port for connecting a current-carrying cable on the charging socket side.

[0045] In this configuration, the wiring that charges the battery from the charging socket is also connected to the distribution unit, making it possible to centrally manage the power wiring to the battery using the distribution unit.

[0046] In the present invention, it is preferable that a radiator for cooling at least one of the battery, the first electric motor, and the second electric motor, and a cooling fan for generating cooling air are provided, the radiator and the cooling fan are arranged in front of the battery and the distribution unit, and the cooling fan is configured to generate the cooling air flowing rearward.

[0047] According to this configuration, the radiator and cooling fan are disposed in front of the battery and distribution unit. The cooling fan blows cooling air toward the side where the distribution unit is located. With this configuration, the cooling fan is used both to cool the radiator (promote heat dissipation) and to cool the battery and distribution unit with the cooling air.

[0048] In the present invention, it is preferable that the vertical width of the front part of the case of the distribution unit is formed so as to become smaller toward the front.

[0049] With this configuration, the flow of cooling air is divided into upper and lower flows across the case of the distribution unit, promoting heat dissipation from the distribution unit by the cooling air.

[0050] In the present invention, it is preferable that a hydraulic piping is provided which is connected to a hydraulic drive device that is driven based on the drive of the second electric motor, the hydraulic piping is arranged on one side, left or right, of the battery, and the distribution unit is arranged on the other side, left or right, of the battery.

[0051] This configuration allows the hydraulic system piping and the power cables between the battery and the two electric motors to be distributed to the left and right sides of the battery, further simplifying the wiring configuration of the power cables and enabling more efficient distribution of power from the battery to the multiple electric motors.

[0052] 1 is a diagram showing a first embodiment (the same applies to Fig. 14 below) and is a left side view of an electric tractor. FIG. 2 is a plan view showing the configuration of a front frame and a storage frame, etc.; FIG. 3 is a left side view showing the configuration of a first battery, etc.; FIG. 4 is a right side view showing the configuration of a first battery, etc.; FIG. 5 is a longitudinal front view showing the configuration of a first battery, etc.; FIG. 6 is a left side view showing the configuration of a support mechanism; FIG. 7 is a right side view showing the configuration of a support mechanism; FIG. 8 is a plan view showing the configuration of a support mechanism.; FIG. 9 is a left side view showing the configuration of a connecting section, etc.; FIG. 10 is a plan view showing the configuration of a first battery support section, a second battery support section, etc.; FIG. 11 is a rear view showing the configuration of a first battery support section, a second battery support section, etc.; FIG. 12 is a diagram showing the circulation paths of a first coolant and a second coolant; FIG. 13 is a diagram showing the configuration of a first cooling path, a second cooling path, etc.; FIG. 14 is a diagram showing the circulation paths of a first coolant and a second coolant in a first alternative embodiment; FIG. 25 is a diagram showing a second embodiment (the same applies to Fig. 21 below) and is an overall side view of an electric tractor. FIG. 15 is an overall plan view of an electric tractor. FIG. 16 is an overall side view of an electric tract to which a front loader is attached. FIG. 17 is a block diagram showing the power system and power system of an electric tractor. It is a front view of a main part showing a battery and devices arranged around the battery.It is a side view of a main part showing a battery, a distribution unit, etc ...

[0053] [First Embodiment] An embodiment of the present invention will be described with reference to the drawings. More specifically, the first embodiment will be described with reference to Figs. 1 to 14. 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."

[0054] [Overall Configuration of Electric Tractor] As shown in Figure 1, in an electric tractor A, left and right front wheels 1 (corresponding to the "traveling device" according to the present invention) are provided at the front of the machine body. Also, left and right rear wheels 2 (corresponding to the "traveling device" according to the present invention) are provided at the rear of the machine body. The machine body is supported by the front wheels 1 and the rear wheels 2.

[0055] The electric tractor A includes left and right front frames 4, a storage frame 5, and a transmission case 6. As shown in Figures 1 and 2, the front frame 4 extends in the front-to-rear direction. The rear end of the front frame 4 is connected to the front portion of the storage frame 5. The transmission case 6 is connected to the rear portion of the storage frame 5.

[0056] 2, a first motor 11 (corresponding to the "motor" according to the present invention) and a second motor 12 are housed in a housing frame 5. The first motor 11 and the second motor 12 are both electric motors.

[0057] 1 and 2, a front axle case 7 is attached to the front frame 4. Left and right front wheels 1 are attached to the front axle case 7. Left and right rear wheels 2 are attached to the transmission case 6.

[0058] A driver's section 8 on which an operator can ride is provided above the accommodation frame 5 and the transmission case 6. That is, the electric tractor A is equipped with a driver's section 8 on which an operator can ride.

[0059] A ROPs frame 9 is attached to the transmission case 6 and extends upward. The ROPs frame 9 is provided behind the driver's section 8. A plurality of first batteries 10 (corresponding to the "batteries" according to the present invention) are supported by the front frame 4.

[0060] The plurality of first batteries 10 are arranged in the front portion of the electric tractor A. A hood 15 is provided to cover the plurality of first batteries 10. Although not particularly limited, the number of first batteries 10 in this embodiment is two.

[0061] One or more air inlet holes (not shown) are formed in the front part of the bonnet 15. Furthermore, the wind (air) generated by the vehicle traveling is introduced into the inside of the bonnet 15 via the air inlet holes.

[0062] The first motor 11 and the second motor 12 are driven by power supplied from a plurality of first batteries 10. Although not particularly limited, the plurality of first batteries 10 in this embodiment are electrically connected in series.

[0063] As described above, the electric tractor A is equipped with a first battery 10 disposed at the front of the vehicle body. More specifically, the electric tractor A is equipped with a plurality of first batteries 10. Even more specifically, the electric tractor A is equipped with two first batteries 10. The electric tractor A also is equipped with a first motor 11 and a second motor 12 that are driven by power supplied from the first batteries 10.

[0064] A first inverter 13 is attached to the left side of the storage frame 5. A second inverter 14 is attached to the right side of the storage frame 5. Electric power from the plurality of first batteries 10 is supplied to the first inverter 13. Based on operation of a speed change pedal 35 (see FIG. 1 ) of the driving unit 8, the first inverter 13 converts DC power from the plurality of first batteries 10 into AC power and supplies it to the first motor 11. This drives the first motor 11.

[0065] As described above, the electric tractor A is equipped with the first inverter 13 that converts DC power from the first battery 10 into AC power and supplies it to the first motor 11 .

[0066] The power of the plurality of first batteries 10 is supplied to the second inverter 14. The second inverter 14 converts the DC power from the plurality of first batteries 10 into AC power and supplies it to the second motor 12. This drives the second motor 12.

[0067] As described above, the electric tractor A is provided with the second inverter 14 that converts DC power from the first battery 10 into AC power and supplies it to the second motor 12 .

[0068] Although not particularly limited, the first inverter 13 and the second inverter 14 may each be housed in a case (not shown).

[0069] The first battery 10 is, for example, a lithium-ion battery. Although not shown, the first battery 10 includes small, low-voltage unit cells and a storage case. The first battery 10 includes a stack of multiple unit cells. The multiple unit cells are housed and sealed in the storage case. The output voltage of the first battery 10 is, for example, 400 volts.

[0070] A hydraulic multi-plate traveling clutch (not shown), a transmission (not shown), and a rear wheel differential (not shown), which are transmission mechanisms, are provided inside the transmission case 6. The transmission is configured as a gear-shift type and is capable of switching between two speed states: a high-speed state and a low-speed state. Power from the output shaft (not shown) of the first motor 11 is transmitted to the traveling clutch, from the traveling clutch to the transmission, and from the transmission to the rear wheels 2 via the rear wheel differential. The output shaft of the first motor 11 extends rearward.

[0071] Inside the transmission case 6, the power branched off between the transmission and the rear wheel differential device is transmitted to the front wheel transmission shaft 31 described later, from the front wheel transmission shaft 31 to the front wheel differential device (not shown) inside the front axle case 7, and from the front wheel differential device to the front wheels 1.

[0072] With the configuration described above, the left and right front wheels 1 and the left and right rear wheels 2 are driven by the first motor 11. That is, the electric tractor A has the left and right front wheels 1 and the left and right rear wheels 2 driven by the first motor 11.

[0073] A PTO shaft 28 is provided facing rearward at the rear of the transmission case 6. A mid-PTO shaft 29 is provided facing forward at the bottom of the transmission case 6. A hydraulic multi-plate PTO clutch (not shown) and a PTO transmission system (not shown), which serve as a transmission mechanism, are provided inside the transmission case 6.

[0074] The power of the output shaft (not shown) of the second motor 12 is transmitted to the PTO clutch, from the PTO clutch to the PTO transmission system, and from the PTO transmission system to the PTO shaft 28 and the mid-PTO shaft 29. The output shaft of the second motor 12 extends rearward.

[0075] As shown in Fig. 1 , when the implement E is attached to the rear of the machine body, the power of the PTO shaft 28 is transmitted to the implement E. As a result, the PTO shaft 28 transmits the driving force of the second motor 12 to the implement E. In the example shown in Fig. 1 , the implement E is a rotary tiller. However, the present invention is not limited to this. The implement E attached to the rear of the machine body may be any device other than a rotary tiller.

[0076] Furthermore, for example, when a working device E such as a mower (not shown) is attached between the front wheel 1 and the rear wheel 2 on the lower part of the machine body (in other words, in the center of the machine body in the longitudinal direction), the power of the mid-PTO shaft 29 is transmitted to the working device E. However, the present invention is not limited to this. The working device E attached to the center of the machine body in the longitudinal direction may be any device other than a mower.

[0077] With the configuration described above, the PTO shaft 28 and the mid-PTO shaft 29 transmit the driving force of the second motor 12 to the work device E. In other words, the electric tractor A is equipped with the PTO shaft 28 and the mid-PTO shaft 29 that transmit the driving force of the second motor 12 to the work device E.

[0078] The electric tractor A can travel while driving the work implement E by simultaneously driving the first motor 11 and the second motor 12 .

[0079] As shown in Figure 2, a pipe member 30 is provided between the rear of the housing frame 5 and the front axle case 7. The pipe member 30 extends in the front-to-rear direction. The front wheel transmission shaft 31 described above is provided inside the pipe member 30. The front wheel transmission shaft 31 is provided between the inside of the transmission case 6 and the front wheel differential device of the front axle case 7.

[0080] As shown in Figure 1, the driver's section 8 is provided with a steering wheel 33 for steering the front wheels 1, a driver's seat 34, a speed change pedal 35, a brake pedal 36, etc. An operator can sit in the driver's seat 34. When the operator operates the brake pedal 36, brakes (not shown) that can brake the left and right rear wheels 2 are activated. As a result, the left and right rear wheels 2 are subjected to a braking action.

[0081] A foot step 41 is attached to the lower left part of the driver's section 8. An operator uses this step 41 to get on and off the driver's section 8 mainly from the left side of the machine body.

[0082] [Configuration inside the hood] As shown in Figures 3 to 5, the electric tractor A is equipped with an upper battery 21, a lower battery 22, a first radiator 38, a second radiator 39, a third radiator 40, a cooling fan 42, a first reserve tank 43, and a second reserve tank 44.

[0083] The electric tractor A also includes a plurality of electrical components N. In this embodiment, the plurality of electrical components N specifically include a charge control device 23, a junction box 24, a first control unit 25, a second control unit 26, a second battery 27, and a voltage converter 37.

[0084] The upper battery 21, the lower battery 22, the charge control device 23, the junction box 24, the first control unit 25, the second control unit 26, the second battery 27, the voltage converter 37, the first radiator 38, the second radiator 39, the third radiator 40, the cooling fan 42, the first reserve tank 43, and the second reserve tank 44 are all covered (in other words, housed) by the hood 15.

[0085] The upper battery 21 and the lower battery 22 are both the first battery 10. That is, the electric tractor A is equipped with a hood 15 that covers the first battery 10. Although not particularly limited, the specifications of the upper battery 21 and the lower battery 22 are the same. In other words, the upper battery 21 and the lower battery 22 are the same type of battery.

[0086] The upper battery 21 is disposed above the lower battery 22. As a result, the plurality of first batteries 10 are aligned vertically. More specifically, two first batteries 10 are aligned vertically.

[0087] The lower surface of the upper battery 21 and the upper surface of the lower battery 22 are spaced apart from each other. That is, a gap G exists between the upper battery 21 and the lower battery 22. In this way, a gap G exists between the plurality of first batteries 10.

[0088] The electric tractor A also includes a charging socket (not shown). When an operator or the like inserts a charger adapter into the charging socket, each of the first batteries 10 is charged. The charging socket receives power for charging each of the first batteries 10. The standard of the charging socket may be, for example, CHAdeMO, CCS2, GB / T, ChaoJi, NACS, or the like.

[0089] The charge control device 23 may be a power module or a PLC (programmable logic controller) having a microcomputer that executes a program for charging each first battery 10, or may be a relay circuit that operates based on an electrical signal. The charge control device 23 controls the charging voltage and charging current for each first battery 10 when charging (including rapid charging) each first battery 10.

[0090] The junction box 24 is electrically connected to the first battery 10, the first inverter 13, the second inverter 14, the voltage converter 37, and the charging socket. The junction box 24 functions as a hub that distributes power from the first battery 10 to each of the first inverter 13, the second inverter 14, and the voltage converter 37. The junction box 24 also receives charging power from the charging socket and transmits it to the first battery 10.

[0091] The first control unit 25 and the second control unit 26 are both ECUs (electronic control units) that control various parts of the electric tractor A. Although not particularly limited, for example, the first control unit 25 may be an ECU for controlling electric components (more specifically, for example, the cooling fan 42 and the first and second pumps 86 and 87 described below), and the second control unit 26 may be an ECU for controlling the main unit (more specifically, for example, the first and second inverters 13 and 14).

[0092] The second battery 27 is a battery for the auxiliary equipment. The second battery 27 is, for example, a lead battery. The second battery 27 supplies low-voltage (e.g., 12 volts) power to drive the auxiliary equipment (e.g., the cooling fan 42 and the first and second pumps 86 and 87 described below). The output voltage of the second battery 27 is lower than the output voltage of the first battery 10. The second battery 27 may also supply power to ECUs such as the first control unit 25 and the second control unit 26.

[0093] Furthermore, power is sent from the first battery 10 to the voltage converter 37. The voltage converter 37 steps down the power from the first battery 10 and supplies it to the second battery 27. This allows the second battery 27 to be charged.

[0094] Thus, the multiple electrical components N include a second battery 27 for auxiliary equipment, a voltage converter 37 that reduces the voltage of the power from the first battery 10 and supplies it to the second battery 27, and a junction box 24.

[0095] The electric tractor A is equipped with a first cooling path J1 and a second cooling path J2 through which coolant circulates. A first coolant (corresponding to the "coolant" according to the present invention) circulates through the first cooling path J1. A second coolant (corresponding to the "coolant" according to the present invention) circulates through the second cooling path J2. That is, the electric tractor A is equipped with the first cooling path J1 through which the first coolant circulates and the second cooling path J2 through which the second coolant circulates.

[0096] Although not particularly limited, in this embodiment, the first coolant and the second coolant are different types of coolants. Specifically, the first coolant is a known LLC (long life coolant), and the second coolant is an oil having insulating properties.

[0097] The first radiator 38 is included in the first cooling path J1. The first radiator 38 cools the first coolant. That is, the electric tractor A has the first radiator 38 that is included in the first cooling path J1 and cools the first coolant.

[0098] The second radiator 39 is included in the second cooling path J2. The second radiator 39 cools the second coolant. That is, the electric tractor A has the second radiator 39, which is included in the second cooling path J2 and cools the second coolant.

[0099] The third radiator 40 is included in the second cooling path J2. The third radiator 40 cools the second coolant.

[0100] The third radiator 40 is disposed below the first radiator 38. The first radiator 38 and the third radiator 40 constitute a radiator device K. The second radiator 39 is disposed in front of the radiator device K.

[0101] The cooling fan 42 is disposed behind the first radiator 38, the second radiator 39, and the third radiator 40. The cooling fan 42 blows cooling air rearward. As a result, outside air is introduced into the inside of the hood 15 through the air inlet holes and passes through the first radiator 38, the second radiator 39, and the third radiator 40. As a result, the first radiator 38, the second radiator 39, and the third radiator 40 are cooled.

[0102] The cooling fan 42 is disposed in front of the upper battery 21 and the lower battery 22. The cooling fan 42 is disposed in front of the lower battery 22.

[0103] The first reserve tank 43 is included in the first cooling path J1. The first reserve tank 43 is capable of storing the first coolant.

[0104] The second reserve tank 44 is included in the second cooling path J2. The second reserve tank 44 is capable of storing the second coolant.

[0105] 3 to 5 , the charge control device 23 and the junction box 24 are disposed on the left side of the first battery 10. The first control unit 25, the second control unit 26, the second battery 27, and the voltage converter 37 are disposed on the right side of the first battery 10. That is, the multiple electrical components N are disposed on the left and right sides of the first battery 10. Furthermore, the voltage converter 37 and the junction box 24 are disposed on the left and right sides of the first battery 10.

[0106] 3 to 5 show a reference position T. The reference position T is the lower end position of the upper battery 21. The charge control device 23, the second reserve tank 44, the first control unit 25, the second control unit 26, and the second battery 27 are all located above the reference position T. The voltage converter 37 and the junction box 24 are all located below the reference position T.

[0107] In this way, the electrical components N are arranged above and below the lower end position of the upper first battery 10. Furthermore, the voltage converter 37 and the junction box 24 are both arranged below the lower end position of the upper first battery 10.

[0108] As shown in Fig. 3, the second reserve tank 44 is located in front of the charge control device 23. As shown in Fig. 4, the second control unit 26 is located in front of the first control unit 25. In addition, the second battery 27 is located in front of the second control unit 26.

[0109] 3 and 5, a first support stay 46 and a second support stay 47 are provided on the left wall of the upper battery 21. The first support stay 46 and the second support stay 47 may be part of the upper battery 21, or may not be included in the upper battery 21.

[0110] The second support stay 47 is disposed rearward of the first support stay 46. A front support portion 44a extending forward is provided at the front end of the second reserve tank 44. A rear support portion 44b extending rearward is provided at the rear end of the second reserve tank 44.

[0111] The front support portion 44a is supported by the first support stay 46 while abutting against the first support stay 46 from above. The rear support portion 44b is supported by the second support stay 47 while abutting against the second support stay 47 from above. As a result, the second reserve tank 44 is supported on the left side wall of the upper battery 21 via the first support stay 46 and the second support stay 47.

[0112] A first plate-shaped member 48 is attached to the second support stay 47 by, for example, welding or bolting. The first plate-shaped member 48 is disposed behind the second support stay 47. The first plate-shaped member 48 is disposed in a position facing the left wall of the upper battery 21.

[0113] The charging control device 23 is supported by the first plate-shaped member 48 while abutting against the first plate-shaped member 48 from the left side. The charging control device 23 may be fixed to the first plate-shaped member 48 by, for example, bolting.

[0114] 4 and 5, a third support stay 49 and a fourth support stay 50 are provided on the right wall of the upper battery 21. The third support stay 49 and the fourth support stay 50 may be part of the upper battery 21, or may not be included in the upper battery 21.

[0115] As shown in Figures 4 and 5, the electric tractor A is equipped with a second plate-shaped member 51. The second plate-shaped member 51 has an upper portion 51a, a horizontal portion 51b, and a lower portion 51c. The upper portion 51a and the lower portion 51c are both in a vertical position and face the right wall of the upper battery 21. The horizontal portion 51b is in a horizontal position.

[0116] The lower end of the upper portion 51a is connected to the left end of the horizontal portion 51b, and the upper end of the lower portion 51c is connected to the right end of the horizontal portion 51b.

[0117] The horizontal portion 51b is supported by the third support stay 49 while abutting against the third support stay 49 from above. In this way, the second plate-shaped member 51 is supported by the third support stay 49. The second plate-shaped member 51 may be fixed to the third support stay 49 by, for example, bolting.

[0118] The first control unit 25 and the second control unit 26 are supported by the upper portion 51 a in a state of contacting the upper portion 51 a from the right side. The first control unit 25 and the second control unit 26 may be fixed to the upper portion 51 a by, for example, bolting.

[0119] As a result, the first control unit 25 and the second control unit 26 are supported on the right side wall of the upper battery 21 via the second plate-shaped member 51 and the third support stay 49 .

[0120] 4 and 5 , the second battery 27 is supported by the fourth support stay 50 while abutting against the fourth support stay 50 from above. As a result, the second battery 27 is supported on the right side wall of the upper battery 21 via the fourth support stay 50.

[0121] 3 to 5, the electric tractor A includes a support mechanism W. The support mechanism W is supported by the left and right front frames 4. The voltage converter 37 and the junction box 24 are both supported by the support mechanism W.

[0122] As shown in FIGS. 3 and 4, the cooling fan 42 and the radiator unit K are supported by the left and right front frames 4.

[0123] An upper support member 52 is provided spanning the upper end of the radiator device K and the upper end of the second radiator 39. Furthermore, a lower support member 53 is provided spanning the lower end of the radiator device K and the lower end of the second radiator 39. The second radiator 39 is supported by the upper support member 52 and the lower support member 53. As a result, the second radiator 39 is supported by the radiator device K via the upper support member 52 and the lower support member 53.

[0124] The first reserve tank 43 is supported by the radiator device K in a state where it abuts against the radiator device K from above.

[0125] [Configuration of Support Mechanism] As shown in FIG. 2 , the electric tractor A includes a third plate-shaped member 54 , a fifth support stay 55 , and a sixth support stay 56 .

[0126] The third plate-like member 54 is a horizontally oriented plate-like member. The third plate-like member 54 is disposed across the left and right front frames 4. As shown in Fig. 5 , the third plate-like member 54 is supported by the left and right front frames 4 while abutting against the left and right front frames 4 from above.

[0127] 5, the electric tractor A is also provided with a channel-shaped reinforcing frame 73. The reinforcing frame 73 is sandwiched between the left and right front frames 4 and fixed to the left and right front frames 4 by, for example, welding. The reinforcing frame 73 also abuts against the third plate-shaped member 54 from below. The reinforcing frame 73 is fixed to the third plate-shaped member 54 by, for example, welding.

[0128] The fifth support stay 55 and the sixth support stay 56 shown in Fig. 2 are both plate-like members bent into an L shape. The fifth support stay 55 is attached to the left front frame 4. The sixth support stay 56 is attached to the right front frame 4. The fifth support stay 55 and the sixth support stay 56 are disposed rearward of the third plate-like member 54.

[0129] 6 to 8 , the support mechanism W is made up of left and right support frames 58, a bottom plate portion 59, and a fourth plate-like member 62. That is, the support mechanism W has left and right support frames 58.

[0130] The left and right support frames 58 are made up of a left support frame 60 and a right support frame 61. The left support frame 60 is the left side support frame 58. The right support frame 61 is the right side support frame 58.

[0131] The left support frame 60 is disposed along the left side wall of the lower battery 22. The right support frame 61 is disposed along the right side wall of the lower battery 22. That is, each support frame 58 is disposed along the side wall of the lower battery 22. The lower battery 22 is disposed between the left and right support frames 58.

[0132] The bottom plate portion 59 is a horizontally oriented plate-like member. The left and right support frames 58 are supported by the bottom plate portion 59 while abutting against the bottom plate portion 59 from above. The left and right support frames 58 are attached to the bottom plate portion 59 by, for example, welding or bolting.

[0133] 5 and 8 , a hole 59a is provided in the front portion of the bottom plate portion 59. The fourth plate-shaped member 62 is a horizontally oriented plate-shaped member. The fourth plate-shaped member 62 is attached to the bottom surface of the bottom plate portion 59 by, for example, welding or bolting, so as to cover the hole 59a from below.

[0134] 6 and 7 , the fourth plate-shaped member 62 is supported by the third plate-shaped member 54 while abutting against the third plate-shaped member 54 from above. As a result, the front portion of the support mechanism W is supported by the left and right front frames 4 via the third plate-shaped member 54.

[0135] 5, the fourth plate-shaped member 62, the third plate-shaped member 54, and the reinforcing frame 73 are fastened together by fixing bolts 74. Furthermore, bolt holes 62a are formed in the fourth plate-shaped member 62. The fixing bolts 74 are inserted into the bolt holes 62a. Note that the number of fixing bolts 74 and the number of bolt holes 62a may be any number.

[0136] As shown in FIG. 8, in a plan view, the bolt hole 62a is provided inside the hole 59a (in other words, at a position corresponding to the hole 59a).

[0137] 6 and 7 , the rear portion of the support mechanism W is supported by the fifth support stay 55 and the sixth support stay 56 while abutting against the fifth support stay 55 and the sixth support stay 56 from above. As a result, the rear portion of the support mechanism W is supported by the left and right front frames 4 via the fifth support stay 55 and the sixth support stay 56.

[0138] 6 and 8 , the left support frame 60 includes a first column frame 63, a second column frame 64, a first connecting frame 65, and a second connecting frame 66. The first column frame 63 and the second column frame 64 both extend in the vertical direction. The lower ends of the first column frame 63 and the second column frame 64 are attached to the upper surface of the bottom plate portion 59 by, for example, welding or bolting. The first column frame 63 is located forward of the second column frame 64.

[0139] The first connecting frame 65 and the second connecting frame 66 both extend in the front-to-rear direction. The first connecting frame 65 is positioned higher than the second connecting frame 66. The front end of the first connecting frame 65 is connected to the upper part of the first pillar frame 63. The rear end of the first connecting frame 65 is connected to the upper part of the second pillar frame 64. The front end of the second connecting frame 66 is connected to the lower part of the first pillar frame 63. The rear end of the second connecting frame 66 is connected to the lower part of the second pillar frame 64. The first connecting frame 65 and the second connecting frame 66 are spaced apart from each other in the up-down direction.

[0140] 7 and 8 , the right support frame 61 includes a third pillar frame 67, a fourth pillar frame 68, a third connecting frame 69, and a fourth connecting frame 70. The third pillar frame 67 and the fourth pillar frame 68 both extend in the vertical direction. The lower ends of the third pillar frame 67 and the fourth pillar frame 68 are attached to the upper surface of the bottom plate portion 59 by, for example, welding or bolting. The third pillar frame 67 is located forward of the fourth pillar frame 68.

[0141] The third connection frame 69 and the fourth connection frame 70 both extend in the front-to-rear direction. The third connection frame 69 is positioned higher than the fourth connection frame 70. The front end of the third connection frame 69 is connected to the upper part of the third pillar frame 67. The rear end of the third connection frame 69 is connected to the upper part of the fourth pillar frame 68. The front end of the fourth connection frame 70 is connected to the lower part of the third pillar frame 67. The rear end of the fourth connection frame 70 is connected to the lower part of the fourth pillar frame 68. The third connection frame 69 and the fourth connection frame 70 are spaced apart from each other in the up-down direction.

[0142] 6 to 8 , the first support section S1 is configured by the bottom plate section 59, the first pillar frame 63, the second pillar frame 64, the third pillar frame 67, and the fourth pillar frame 68. The first support section S1 supports the upper battery 21 and the lower battery 22. That is, the first support section S1 supports the multiple first batteries 10.

[0143] 5 to 7 , the left front portion of the upper battery 21 is supported by the upper end of the first pillar frame 63 at the first support portion S1 via the first elastic member 71. The right front portion of the upper battery 21 is supported by the upper end of the third pillar frame 67 at the first support portion S1 via the first elastic member 71. The left rear portion of the upper battery 21 is supported by the upper end of the second pillar frame 64 at the first support portion S1 via the first elastic member 71. The right rear portion of the upper battery 21 is supported by the upper end of the fourth pillar frame 68 at the first support portion S1 via the first elastic member 71.

[0144] The left front portion of the lower battery 22 is supported by the left front portion of the bottom plate portion 59 of the first support portion S1 via the first elastic member 71. The right front portion of the lower battery 22 is supported by the right front portion of the bottom plate portion 59 of the first support portion S1 via the first elastic member 71. The left rear portion of the lower battery 22 is supported by the left rear portion of the bottom plate portion 59 of the first support portion S1 via the first elastic member 71. The right rear portion of the lower battery 22 is supported by the right rear portion of the bottom plate portion 59 of the first support portion S1 via the first elastic member 71.

[0145] The first elastic member 71 is not particularly limited, but may be, for example, a rubber mount.

[0146] 6 to 8, the second support portion S2 is formed by the first connecting frame 65, the second connecting frame 66, the third connecting frame 69, and the fourth connecting frame 70. The second support portion S2 supports the electrical equipment N (more specifically, the junction box 24 and the voltage converter 37). That is, the electric tractor A is provided with a support mechanism W having the first support portion S1 and the second support portion S2.

[0147] More specifically, the junction box 24 is supported by the first connecting frame 65 and the second connecting frame 66 in a state in which the junction box 24 abuts against the first connecting frame 65 and the second connecting frame 66 at the second support portion S2 from the left side. The junction box 24 is attached to the first connecting frame 65 and the second connecting frame 66 by, for example, bolting.

[0148] The voltage converter 37 is supported by the third connecting frame 69 and the fourth connecting frame 70 in a state in which the voltage converter 37 abuts against the third connecting frame 69 and the fourth connecting frame 70 at the second support portion S2 from the right side. The voltage converter 37 is attached to the third connecting frame 69 and the fourth connecting frame 70 by, for example, bolting.

[0149] [Hydraulic Pump] As shown in Figure 2, the electric tractor A is equipped with a hydraulic pump 72. The hydraulic pump 72 is attached to the right rear portion of the storage frame 5. The power of the output shaft (not shown) of the second motor 12 is transmitted to a power transmission gear (not shown), and then transmitted from the power transmission gear to an input shaft (not shown) of the hydraulic pump 72. In this way, the power of the second motor 12 is transmitted to the hydraulic pump 72. As a result, the hydraulic pump 72 is driven.

[0150] In this way, the electric tractor A is equipped with a hydraulic pump 72 driven by the second motor 12.

[0151] The power transmission gear is housed in the rear part of the housing frame 5. The input shaft of the hydraulic pump 72 extends forward.

[0152] The hydraulic pump 72 supplies hydraulic oil to each part of the electric tractor A. For example, if a front loader device (not shown) is attached to the machine body, the front loader device operates when hydraulic oil is supplied from the hydraulic pump 72 to the front loader device. In addition, various hydraulic devices (not shown) in the machine body operate when hydraulic oil is supplied from the hydraulic pump 72 to the hydraulic devices.

[0153] 1 to 3, a handle support mechanism 16 is provided at the front end of the driver's section 8. A steering handle 33 is supported by the handle support mechanism 16.

[0154] 9 and 10, a pillar frame 18 is provided in front of the handle support mechanism 16. As shown in Fig. 11, the pillar frame 18 is configured in an arch shape (gate shape) when viewed from behind. The pillar frame 18 is supported by the storage frame 5 while abutting against the storage frame 5 from above.

[0155] 9 and 11 , the electric tractor A includes a shaft support portion 75 and a shaft member 76. The shaft support portion 75 is fixed to the upper end portion of the pillar frame 18. The shaft support portion 75 extends upward from the upper end portion of the pillar frame 18.

[0156] The shaft member 76 extends in the left-right direction of the vehicle body. The shaft member 76 is supported by the shaft support portion 75. As a result, the shaft member 76 is supported by the pillar frame 18 via the shaft support portion 75. In other words, the shaft member 76 is supported by the pillar frame 18. Note that the number of shaft support portions 75 and the number of shaft members 76 may be any number.

[0157] 1, 9, and 11, the hood 15 is supported by the shaft member 76 in a state in which it can swing up and down around the shaft member 76. As a result, the hood 15 is supported by the pillar frame 18 via the shaft member 76 and the shaft support portion 75. This also allows the hood 15 to be opened and closed.

[0158] That is, the electric tractor A includes pillar frames 18 that support the hood 15. The hood 15 can be opened and closed by swinging up and down about a shaft member 76 that extends in the left-right direction of the vehicle body.

[0159] 10 and 11 , the electric tractor A includes a first battery support portion 77 and a second battery support portion 78. The first battery support portion 77 is disposed across the upper left portion of the pillar frame 18 and the upper left portion of the upper battery 21. The left end portion of the first battery support portion 77 is fixed to the upper left portion of the pillar frame 18 by welding, for example. The right end portion of the first battery support portion 77 is fixed to the upper left portion of the upper battery 21 by bolting, for example.

[0160] The second battery support portion 78 is disposed so as to span the upper right portion of the pillar frame 18 and the upper right portion of the upper battery 21. The right end portion of the second battery support portion 78 is fixed to the upper right portion of the pillar frame 18 by, for example, welding, etc. The left end portion of the second battery support portion 78 is fixed to the upper right portion of the upper battery 21 by, for example, bolting, etc.

[0161] With this configuration, the upper battery 21 is supported by the pillar frame 18 via the first battery support portion 77 and the second battery support portion 78. In other words, the upper battery 21 is supported by the pillar frame 18.

[0162] 9 and 11, the electric tractor A includes a seventh support stay 79 and a second elastic member 80. The seventh support stay 79 is fixed to the upper end of the pillar frame 18. The seventh support stay 79 extends rearward from the upper end of the pillar frame 18. The second elastic member 80 is attached to the rear end of the seventh support stay 79. Although not particularly limited, the second elastic member 80 may be made of rubber, for example.

[0163] 9 , the second elastic member 80 contacts the front end (more specifically, the front wall) of the handle support mechanism 16. When the hood 15 is opened or closed, the second elastic member 80 suppresses vibrations of the hood 15 and the pillar frames 18 that accompany the opening and closing of the hood 15.

[0164] 9 to 11 , the electric tractor A has left and right connecting portions 81. Each connecting portion 81 is provided across the pillar frame 18 and the front end portion of the handle support mechanism 16. In other words, the electric tractor A has the connecting portion 81 across the pillar frame 18 and the driving portion 8.

[0165] Each connecting portion 81 has a first connecting portion 82, a second connecting portion 83, a third elastic member 84, and a fourth elastic member 85. Although not particularly limited, the third elastic member 84 and the fourth elastic member 85 may be made of rubber, for example.

[0166] The first connecting portion 82 is attached to the pillar frame 18 via a third elastic member 84. The first connecting portion 82 extends rearward from the pillar frame 18.

[0167] The second connecting portion 83 is attached to the rear end of the first connecting portion 82 via a fourth elastic member 85. The second connecting portion 83 is then connected to the front end (more specifically, the front wall) of the handle support mechanism 16 by, for example, welding or bolting.

[0168] With the configuration described above, the pillar frame 18 is connected to the driving section 8 via the left and right connecting portions 81. However, the present invention is not limited to this, and any number of connecting portions 81 may be provided.

[0169] When an operator gets on or off the driving unit 8, vibrations may occur in the driving unit 8. The fourth elastic member 85 prevents vibrations transmitted from the driving unit 8 to the second connecting portion 83 from being transmitted from the second connecting portion 83 to the first connecting portion 82. As a result, the vibrations of the driving unit 8 are prevented from being transmitted to the pillar frame 18.

[0170] Furthermore, the third elastic member 84 suppresses the transmission of vibrations transmitted from the driving section 8 to the first connecting section 82 via the second connecting section 83 from the first connecting section 82 to the pillar frame 18. As a result, the transmission of vibrations of the driving section 8 to the pillar frame 18 is suppressed.

[0171] In this way, the connecting portion 81 has the third elastic member 84 and the fourth elastic member 85 that suppress the transmission of vibrations of the driver's section 8 to the pillar frame 18 .

[0172] 3 and 4, the electric tractor A includes a first pump 86 and a second pump 87. The first pump 86 and the second pump 87 are both disposed below the lower battery 22.

[0173] 12 , the first pump 86 and the second pump 87 are included in the first cooling path J1. The first pump 86 and the second pump 87 may be configured to be driven by power supplied from the second battery 27, for example. The first pump 86 and the second pump 87 pump the first coolant.

[0174] The first cooling path J1 includes a first inverter 13, a first motor 11, a second motor 12, a second inverter 14, a voltage converter 37, a first reserve tank 43, and a first radiator 38.

[0175] That is, the first cooling path J1 includes the voltage converter 37. The first cooling path J1 also includes the first motor 11. The first cooling path J1 also includes the second motor 12.

[0176] The first cooling path J1 includes a first path P1, a second path P2, and a third path P3. The first path P1 connects the first radiator 38 and the first motor 11. In the first path P1, the first coolant flows from the first radiator 38 toward the first motor 11.

[0177] The second path P2 connects the first motor 11 and the second motor 12. The first coolant flows from the first motor 11 to the second motor 12 through the second path P2.

[0178] The third path P3 connects the second motor 12 and the first radiator 38. In the third path P3, the first coolant flows from the second motor 12 toward the first radiator 38.

[0179] That is, the first cooling path J1 has a first radiator 38 that cools the first coolant, a first path P1 along which the first coolant flows from the first radiator 38 toward the first motor 11, a second path P2 along which the first coolant flows from the first motor 11 toward the second motor 12, and a third path P3 along which the first coolant flows from the second motor 12 toward the first radiator 38.

[0180] The first path P1 will now be described in detail. The first path P1 includes a first hose 96, a first pump 86, a second hose 88, a second pump 87, a third hose 89, a first inverter 13, and a fourth hose 90. That is, the first inverter 13 is included in the first path P1.

[0181] The first hose 96 connects the first radiator 38 and the first pump 86. The second hose 88 connects the first pump 86 and the second pump 87. The third hose 89 connects the second pump 87 and the first inverter 13. The fourth hose 90 connects the first inverter 13 and the first motor 11.

[0182] 3 , 4 , and 13 , a portion of the first hose 96 and a portion of the third hose 89 are located below the upper battery 21 and the lower battery 22. Furthermore, the first pump 86, the second hose 88, and the second pump 87 are located below the upper battery 21 and the lower battery 22. In this manner, at least a portion of the first path P1 is located below the first battery 10. Note that only a portion of the first path P1 may be located below the first battery 10, or the entire first path P1 may be located below the first battery 10.

[0183] 12 , the second path P2 is formed by a fifth hose 91. The fifth hose 91 connects the first motor 11 and the second motor 12.

[0184] The third path P3 will now be described in detail. The third path P3 includes the sixth hose 92, the second inverter 14, the seventh hose 93, the voltage converter 37, the eighth hose 94, the first reserve tank 43, and the ninth hose 95. That is, the second inverter 14 is included in the third path P3.

[0185] 3, 4, and 13, a portion of the seventh hose 93 and a portion of the eighth hose 94 are located to the right of the lower battery 22. In addition, a portion of the eighth hose 94 is located to the right of the upper battery 21. In addition, the voltage converter 37 is located to the right of the lower battery 22.

[0186] As a result, at least a portion of the third path P3 is located to the right of the first battery 10. However, the present invention is not limited to this. For example, the arrangement of the seventh hose 93, the eighth hose 94, and the voltage converter 37 may be reversed in the left-right direction. That is, at least a portion of the third path P3 is located to the left or right of the first battery 10. Only a portion of the third path P3 may be located to the left or right of the first battery 10, or the entire third path P3 may be located to the left or right of the first battery 10.

[0187] 12 , the first pump 86 and the second pump 87 are connected in series by a second hose 88. The first coolant pumped by the first pump 86 and the second pump 87 flows through the third hose 89, the first inverter 13, the fourth hose 90, the first motor 11, the fifth hose 91, the second motor 12, the sixth hose 92, the second inverter 14, the seventh hose 93, the voltage converter 37, the eighth hose 94, the first reserve tank 43, the ninth hose 95, the first radiator 38, and the first hose 96 in this order, before returning to the first pump 86 and the second pump 87.

[0188] 3, 4, and 13, the ninth hose 95 is not shown. Instead of providing the ninth hose 95, the first reserve tank 43 and the first radiator 38 may be directly connected to each other.

[0189] 3 and 4, the electric tractor A includes a third pump 17 and a battery heater 19. The third pump 17 is disposed below the radiator device K and the second radiator 39. The battery heater 19 is disposed below the lower battery 22.

[0190] 12, the third pump 17 and the battery heater 19 are included in the second cooling path J2. The third pump 17 may be configured to be driven by power supplied from the second battery 27, for example. The third pump 17 pumps the second coolant.

[0191] The battery heater 19 may also be configured to be driven by power supplied from the second battery 27. The battery heater 19 heats the second coolant when the upper battery 21 and the lower battery 22 are in a low-temperature state.

[0192] The second cooling path J2 includes the upper battery 21, the lower battery 22, the third radiator 40, the second radiator 39, and the second reserve tank 44. That is, the second cooling path J2 includes the first battery 10.

[0193] The second cooling path J2 includes a tenth hose 97, an eleventh hose 98, a twelfth hose 99, a thirteenth hose 100, a fourteenth hose 101, a fifteenth hose 102, and a sixteenth hose 103.

[0194] The tenth hose 97 connects the third pump 17 and the battery heater 19. The eleventh hose 98 connects the battery heater 19 and the upper battery 21. The twelfth hose 99 connects the upper battery 21 and the lower battery 22. The thirteenth hose 100 connects the lower battery 22 and the third radiator 40. The fourteenth hose 101 connects the third radiator 40 and the second radiator 39. The fifteenth hose 102 connects the second radiator 39 and the second reserve tank 44. The sixteenth hose 103 connects the second reserve tank 44 and the third pump 17.

[0195] 3, 4, and 13, a portion of the fifteenth hose 102 and a portion of the sixteenth hose 103 are located to the left of the upper battery 21. In addition, a portion of the sixteenth hose 103 is located to the left of the lower battery 22. In addition, the second reserve tank 44 is located to the left of the upper battery 21.

[0196] As a result, at least a portion of the second cooling path J2 is located to the left of the first battery 10. However, the present invention is not limited to this. For example, the arrangement of the fifteenth hose 102, the sixteenth hose 103, and the second reserve tank 44 may be reversed in the left-right direction.

[0197] With the configuration described above, at least a portion of the first cooling path J1 (more specifically, the third path P3) passes through one of the left and right sides (the right side in this embodiment) of the first battery 10. Also, at least a portion of the second cooling path J2 passes through the other of the left and right sides (the left side in this embodiment) of the first battery 10.

[0198] Only a portion of the first cooling path J1 may pass through one of the left and right sides of the first battery 10, or the entire first cooling path J1 may pass through one of the left and right sides of the first battery 10. Also, only a portion of the second cooling path J2 may pass through the other of the left and right sides of the first battery 10, or the entire second cooling path J2 excluding the first battery 10 may pass through the other of the left and right sides of the first battery 10.

[0199] As shown in Figure 12, the second coolant pumped by the third pump 17 flows in the following order: the tenth hose 97, the battery heater 19, the eleventh hose 98, the upper battery 21, the twelfth hose 99, the lower battery 22, the thirteenth hose 100, the third radiator 40, the fourteenth hose 101, the second radiator 39, the fifteenth hose 102, the second reserve tank 44, and the sixteenth hose 103, before returning to the third pump 17.

[0200] 12, the first cooling path J1 and the second cooling path J2 do not communicate with each other, that is, the first cooling path J1 and the second cooling path J2 are independent from each other.

[0201] According to the configuration described above, the first battery 10 is supported by the support mechanism W. Furthermore, the support mechanism W also supports the electrical equipment N. This makes it easier to ensure a larger space for arranging the first battery 10 than when a mechanism for supporting the first battery 10 and a mechanism for supporting the electrical equipment N are separately provided. As a result, a relatively large first battery 10 can be mounted.

[0202] That is, according to the configuration described above, an electric tractor A equipped with a first battery 10 having a relatively large capacity can be realized.

[0203] According to the configuration described above, the multiple electrical components N are distributed to the left and right of the first battery 10. This improves the weight balance in the left-right direction of the vehicle body compared to when the multiple electrical components N are concentrated to the left or right of the first battery 10.

[0204] Furthermore, the positions of the electrical components N are likely to be lower than when the electrical components N are concentrated above the first battery 10. This lowers the center of gravity of the vehicle, thereby improving the stability of the vehicle.

[0205] Furthermore, the positions of the electrical components N are likely to be higher than when the electrical components N are concentrated below the first battery 10. This makes it less likely that muddy water or the like from the ground will adhere to the electrical components N.

[0206] That is, according to the configuration described above, an electric tractor A can be realized in which a plurality of electrical components N are suitably arranged.

[0207] [Alternatives to the First Embodiment] Alternatives to the first embodiment will be described below. Matters other than those described in the following alternative embodiments are the same as those described in the first embodiment.

[0208] [First Alternative Embodiment] In the first cooling path J1 of the above-described embodiment, the first coolant circulates in the direction shown in FIG.

[0209] However, the present invention is not limited to this. Below, a first alternative embodiment of the present invention will be described, focusing on the differences from the above embodiment. The configuration other than the parts described below is the same as the above embodiment. Furthermore, the same reference numerals are used to designate the same components as the above embodiment.

[0210] In the first cooling path J1 of the first alternative embodiment according to the present invention, the direction in which the first pump 86 and the second pump 87 pump the first cooling liquid is opposite to that in the above-described embodiment, so that the first cooling liquid circulates in the direction shown in FIG.

[0211] More specifically, in the first path P1, the first coolant flows from the first motor 11 toward the first radiator 38. In addition, in the second path P2, the first coolant flows from the second motor 12 toward the first motor 11. In addition, in the third path P3, the first coolant flows from the first radiator 38 toward the second motor 12.

[0212] That is, the first cooling path J1 has a first radiator 38 that cools the first coolant, a first path P1 along which the first coolant flows from the first motor 11 to the first radiator 38, a second path P2 along which the first coolant flows from the second motor 12 to the first motor 11, and a third path P3 along which the first coolant flows from the first radiator 38 to the second motor 12.

[0213] Furthermore, the circulation direction of the first coolant may be switchable between the direction shown in Fig. 12 and the direction shown in Fig. 14 in response to a predetermined manual operation by an operator or automatically. That is, the circulation direction of the first coolant may be changeable.

[0214] Other Embodiments (1) The arrangement of some or all of the components may be reversed in the left-right direction.

[0215] (2) The electric tractor A may be equipped with an engine and configured as a hybrid.

[0216] (3) The number of first batteries 10 provided may be one.

[0217] (4) The second motor 12 does not have to be provided.

[0218] (5) The number of electrical components N supported by the second support portion S2 may be any number.

[0219] (6) Each support frame 58 does not have to be disposed along the side wall of the lower battery 22 .

[0220] (7) The lower battery 22 does not have to be disposed in a position sandwiched between the left and right support frames 58 .

[0221] (8) The first batteries 10 may be arranged in the left-right direction or the front-rear direction.

[0222] (9) The gaps G do not have to exist between the multiple first batteries 10 .

[0223] (10) The second battery 27 does not have to be provided.

[0224] (11) The voltage converter 37 and the junction box 24 may be concentrated on the left or right side of the first battery 10 .

[0225] (12) At least one of the voltage converter 37 and the junction box 24 may be disposed above the lower end position of the upper first battery 10 .

[0226] (13) The first cooling path J1 and the second cooling path J2 may be connected to each other. In addition, the electric tractor A may have only one path through which the coolant circulates.

[0227] (14) The plurality of electrical components N may be concentrated above or below the lower end position of the upper first battery 10 .

[0228] The configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments, unless a contradiction occurs. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these, and can be modified as appropriate within the scope of the present invention.

[0229] Second Embodiment A mode for carrying out the present invention will be described with reference to the drawings. More specifically, the second embodiment will be described mainly with reference to Figures 15 to 21. In the following description, components that are assigned the same reference numerals as those in the first embodiment are the same as those in the first embodiment, and detailed description thereof will be omitted.

[0230] An embodiment illustrating an electric tractor of the present invention will be described based on the electric tractor shown in Figures 15 to 21. In Figures 15 to 21, "F" indicates the forward direction, "B" indicates the backward direction, "U" indicates the upward direction, "D" indicates the downward direction, "R" indicates the rightward direction, and "L" indicates the leftward direction.

[0231] 15 to 17, right and left front wheels 210 are provided at the front of the machine body 201, and right and left rear wheels 211, which are the rear traveling devices, are provided at the rear of the machine body 201. The machine body 201 supports the front wheels 210 and the rear wheels 211.

[0232] The machine body 201 has a front frame 202, a housing frame AA, and a transmission case 215. The front frame 202 is connected to the front of the housing frame AA, and the transmission case 215 is connected to the rear of the housing frame AA, thereby forming the frame structure of the machine body 201. Electric motors M1 and M2, which serve as power sources, are housed in the housing frame AA.

[0233] A front axle case 210A is attached to the front frame 202, and right and left front wheels 210 are attached to the front axle case 210A. The left and right front wheels 210 are supported by the front axle case 210A. The front axle case 210A extends in the left-right direction. The front axle case 210A supports the left and right front wheels 210 and houses axles that transmit power to the left and right front wheels 210. The front frame 202 supports the front axle case 210A. The front wheels 210 and the front axle case 210A are an example of a "running device."

[0234] The transmission case 215 includes an axle case that transmits power to the left and right rear wheels 211. Therefore, the transmission case 215 supports the left and right rear wheels 211. The right and left rear wheels 211 are attached to the transmission case 215. The transmission case 215 supports the left and right rear wheels 211.

[0235] The driver's section 203, on which the operator sits, is provided above the accommodation frame AA and the transmission case 215. A ROP frame 231 is attached to the transmission case 215, extends upward, and is provided at the rear of the driver's section 203. A battery 204 that supplies power to the electric motors M1, M2 is attached to the front frame 202, and a hood 212 is provided to cover the battery 204. The hood 212 corresponds to a "cover member."

[0236] The battery 204 is mounted on and supported by the front frame 202. In other words, the front frame 202 supports the battery 204 from below. The front frame 202 is used to support both the battery 204 and the front axle case 210A of the front wheel 210. The battery 204 is located above the front frame 202. The battery 204 stores electricity for traveling, working, and hydraulic drive.

[0237] 19 and 21 , the hood 212 has a swinging part 212A that swings openably and closably, and a fixed part 212B that is fixed below the swinging part 212A. The swinging part 212A can swing about a horizontal axis that runs along the left-right direction of the vehicle body, thereby enabling the hood 212 to be opened and closed. When the swinging part 212A is in the closed state, the battery 204 is covered by the hood 212.

[0238] The electric tractor of this embodiment has two independent drive systems: a drive system for traveling and a drive system for working. Specifically, as shown in FIG. 16 , the electric tractor is equipped with an electric motor M1 for traveling and an electric motor M2 for working and hydraulic drive. The electric tractor is also equipped with two inverters 214A and 214B corresponding to the two electric motors M1 and M2. The two electric motors M1 and M2 are located on the rear side of the vehicle body relative to the battery 204. The electric motor M1 is a motor for traveling that is powered by the battery 204. The electric motor M2 is a motor for working and hydraulic drive that is powered by the battery 204. The inverters 214A and 214B are located laterally outboard of the vehicle body relative to the electric motors M1 and M2. The electric motor M1 corresponds to the "first electric motor." The electric motor M2 corresponds to the "second electric motor."

[0239] The battery 204 supplies power to two inverters 214A, 214B. Each of the inverters 214A, 214B receives DC current from the battery 204 and converts it into three-phase AC current. The left inverter 214A converts the DC power of the battery 204 into AC power and supplies it to the electric motor M1, thereby operating the electric motor M1. The right inverter 214B converts the DC power of the battery 204 into AC power and supplies it to the electric motor M2, thereby operating the electric motor M2.

[0240] The left and right loader attachment portions 208 are connected to the left and right side portions of the storage frame AA, respectively. A working device such as a front loader FA (see FIG. 17) is attached to each of the left and right loader attachment portions 208. Each of the left and right loader attachment portions 208 supports the working device such as the front loader FA so that it can be attached and detached. The front loader FA is an example of a "hydraulic drive device."

[0241] The valve unit 228 for the hydraulic piping is adjacent to the inverter 214B on the outer side of the machine body and adjacent to the loader attachment portion 208 on the right side of the machine body at the rear side of the machine body. The valve unit 228 for the hydraulic piping is connected and supported by the storage frame AA. A hydraulic piping connector is provided at the base end of the right arm of the front loader FA. Hydraulic piping 228H extending from the valve unit 228 is connected to the hydraulic piping connector of the front loader FA. In other words, the valve unit 228 is configured so that the hydraulic system can be connected to the hydraulic mechanism of the front loader FA when the front loader FA is attached to the loader attachment portion 208. Note that if a backhoe is attached to the rear of the machine body 201, the valve unit 228 may be configured so that the hydraulic system can be connected to the hydraulic mechanism of the backhoe.

[0242] 15 to 17, the driving section 203 is provided behind the battery 204 and the hood 212. The driving section 203 is provided with a ROPS frame 231, a driver's seat 232, a steering wheel 233 for steering the front wheels 210, a step 234, a floor 235, a charging socket 236, a work travel operating tool 237, a display unit 238, and the like.

[0243] The driving section 203 is supported by a housing frame AA and a transmission case 215. The electric motors M1 and M2 are arranged side by side below a floor 235 of the driving section 203 and inside the housing frame AA.

[0244] A footstep 234 is attached to the right side of the floor 235, and operators (passengers) mainly get on and off the driver's section 203 from the left side of the machine body 201. The operator gets on to the floor 235 of the driver's section 203 from the step 234 and can sit in the driver's seat 232. When the operator operates the steering handle 233, the left and right front wheels 210 are steered.

[0245] Although not described in detail, the work travel operating device 237 includes an accelerator operating device for adjusting the travel speed, and operating devices for adjusting the rotation speed of the mid PTO shaft 216A and rear PTO shaft 216B, which will be described later. This allows the operator to perform various driving operations in the driving section 203. The work travel operating device 237 also has potentiometers that detect the amount of operation of the various operating devices.

[0246] The display unit 238 displays, for example, the vehicle's running state, working state, information about the battery 204 (charge level and temperature), and the like.

[0247] The charging socket 236 is provided to the right of the control handle 233 and directly above the floor 235. When an operator or the like inserts a charger adapter into the charging socket 236, the battery 204 is charged. The charging socket 236 receives power for charging the battery 204. The standard of the charging socket 236 may be, for example, CHAdeMO, CCS2, GB / T, ChaoJi, NACS, or the like.

[0248] The housing frame AA, the electric motors M1, M2, the inverters 214A, 214B, and the transmission case 215 are disposed below the floor 235. The battery 204 is disposed above the floor 235. In addition, the battery 204 is provided forward of the driving unit 203 so that the rear end of the battery 204 is located forward of the front ends of the electric motors M1, M2.

[0249] 18 , the power transmission device TA is provided with a power transmission mechanism 215A for traveling, a power transmission mechanism 215B for working, and a hydraulic pump 215C. The transmission case 215 houses the power transmission mechanism 215A for traveling, the power transmission mechanism 215B for working, and the hydraulic pump 215C. In other words, the power transmission device TA has the transmission case 215, the power transmission mechanism 215A for traveling, the power transmission mechanism 215B for working, and the hydraulic pump 215C.

[0250] The power transmission mechanism 215A for traveling receives rotational power from the electric motor M1 and transmits the rotational power to the left and right front wheels 210 and the left and right rear wheels 211 while changing the speed using a gear-type transmission mechanism. As a result, the left and right front wheels 210 and the left and right rear wheels 211 are driven to rotate by the power for traveling from the electric motor M1. In other words, the power transmission mechanism 215A for traveling transmits the power for traveling from the electric motor M1 to the front wheels 210 and the rear wheels 211. In other words, the left and right front wheels 210 and the left and right rear wheels 211 are driven based on the electric power for traveling.

[0251] The electric tractor is also equipped with a mid PTO shaft 216A and a rear PTO shaft 216B. The work power transmission mechanism 215B receives rotational power from the electric motor M2 and distributes the rotational power to the mid PTO shaft 216A and the rear PTO shaft 216B. This causes the mid PTO shaft 216A and the rear PTO shaft 216B to rotate.

[0252] If a work device is connected to at least one of the mid PTO shaft 216A and the rear PTO shaft 216B, the work device is driven by the rotational power of the mid PTO shaft 216A and the rear PTO shaft 216B. In other words, the work power transmission mechanism 215B transmits work power from the electric motor M2 to the mid PTO shaft 216A and the rear PTO shaft 216B. The mid PTO shaft 216A and the rear PTO shaft 216B then supply the work power to the work device.

[0253] The hydraulic pump 215C receives rotational power from the electric motor M2 and is driven to rotate. The hydraulic pump 215C is the drive source for the hydraulic system of the electric tractor. Therefore, when a front loader FA is attached to the tractor, hydraulic oil is pumped by the hydraulic pump 215C. The front loader FA then operates based on the hydraulic pressure of the hydraulic oil. In other words, the hydraulic pump 215C supplies hydraulic pressure for work to the working implement. In other words, the front loader FA is driven based on the drive of the electric motor M2. The hydraulic pump 215C also pumps hydraulic oil for driving the lifting and lowering of the working implements connected to the mid PTO shaft 216A and the rear PTO shaft 216B, respectively.

[0254] In this way, the power transmission device TA is used for transmitting power for traveling, power for working, and hydraulic drive. In other words, the power transmission device TA is provided with a power transmission mechanism 215A for traveling that transmits power from the electric motor M1 to the front wheels 210 and the rear wheels 211, a power transmission mechanism 215B for working that transmits power from the electric motor M2 to the mid PTO shaft 216A and the rear PTO shaft 216B, and a hydraulic pump 215C for hydraulic drive. The power transmission device TA is also disposed behind the electric motors M1 and M2.

[0255] The work implement connected to mid PTO shaft 216A may be, for example, a grass cutter, a rotary rake, a leaf cutter, a spreader, etc. Also, mid PTO shaft 216A may be used as a front PTO shaft for a work implement attached to the front of machine body 201. The work implement connected to rear PTO shaft 216B may be a cultivator, a seed sowing implement, a planter, a fertilizer applicator, a leaf cutter, a spreader, a grass cutter, a baler, a mulcher, a stone picker, a rotary rake, a tedder, a towed harvester and sorter, a top pinching implement, a tillage management implement, a ridge forming implement, etc.

[0256] [Regarding the drive system of the electric tractor] As shown in Figure 18, there is provided a control device 220 that controls the drive of the electric motors M1, M2 in response to the operation of the work travel operating device 237. The control device 220 is a core element of the control system of the electric tractor, and is configured as a collection of multiple ECUs.

[0257] The control device 220 is connected to a charge / discharge control unit 204A of the battery 204, inverters 214A, 214B, electric motors M1, M2, a charge control unit 222, a DC / DC converter 223, a work driving operating tool 237, a display unit 238, etc., via a signal harness 221 of the CAN (Controller Area Network) type, for example, so as to be able to communicate data.

[0258] The control device 220 outputs command signals to the inverters 214A, 214B in response to commands from the work traveling operating device 237. The inverter 214A controls the output of the electric motor M1 by adjusting the three-phase AC power (voltage value, frequency, current value, etc.) supplied from the battery 204 to the electric motor M1 in response to the command signal from the control device 220. Similarly, the inverter 214B controls the output of the electric motor M2 by adjusting the three-phase AC power supplied from the battery 204 to the electric motor M2 in response to the command signal from the control device 220.

[0259] The control device 220 controls the operation of the display unit 238. Therefore, the display unit 238 displays the operating status of the electric motors M1, M2, information about the battery 204, and the like.

[0260] The battery 204 is, for example, a lithium-ion battery. Although not shown, the battery 204 is configured by stacking a large number of small, low-voltage unit cells. The output voltage of the battery 204 is, for example, 400 volts. The unit cells are housed in a storage case. These unit cells are sealed in the storage case.

[0261] The battery 204 is electrically connected to the power distribution unit 213. The power distribution unit 213 is also electrically connected to each of the inverters 214A, 214B and the DC / DC converter 223. Therefore, the power distribution unit 213 functions as a hub that distributes the power from the battery 204 to each of the inverters 214A, 214B and the DC / DC converter 223. As a result, the power distribution unit 213 distributes the power from the battery 204 to each of the electric motors M1 and M2. The power distribution unit 213 corresponds to a "distribution unit."

[0262] The power distribution unit 213 is also connected to the charging socket 236 via the charging control unit 222. The power distribution unit 213 is configured to receive charging power from the charging socket 236 and transmit the power to the battery 204.

[0263] The battery 204 is provided with a charge / discharge control unit 204A. The charge / discharge control unit 204A is configured to control the discharge current, charge current, etc. of the battery 204 based on the output voltage, receiving voltage, heat generation temperature, etc. of the battery 204.

[0264] Because the battery 204 outputs a large amount of power to the inverters 214A and 214B, the amount of heat generated by the battery 204 also increases. Temperature management is also important for appropriately managing the charge and discharge amounts of the battery 204. For this reason, a water-cooled temperature control flow path is installed inside the battery 204. A battery temperature control device 225 for supplying liquid refrigerant to this temperature control flow path is provided near the battery 204.

[0265] The battery temperature adjustment device 225 includes a battery radiator 225A, a reservoir tank 225B, a battery heater 225C, and a pump 225D. Refrigerant is stored in the reservoir tank 225B. The pump 225D pumps the refrigerant that cools the battery 204. The battery heater 225C heats the refrigerant, thereby raising the temperature of the battery 204. When the pump 225D is operating, the refrigerant circulates from the reservoir tank 225B through the battery heater 225C, the pump 225D, a temperature adjustment flow path inside the battery 204, and the battery radiator 225A in this order. In this way, the battery temperature adjustment device 225 is configured to adjust the temperature of the battery 204.

[0266] The battery heater 225C is provided between the pump 225D and the inlet of the temperature control flow path inside the battery 204. When the temperature of the battery 204 is low, the current for charging and discharging the battery 204 is low. When the electric tractor is started in this state, the charge / discharge control unit 204A operates the battery heater 225C to heat the refrigerant. This allows the temperature of the battery 204 to quickly rise to a temperature appropriate for charging and discharging.

[0267] The battery radiator 225A is provided between the reservoir tank 225B and the outlet of the temperature control flow path inside the battery 204. Therefore, the refrigerant heated in the temperature control flow path inside the battery 204 is cooled by heat dissipation in the battery radiator 225A and returned to the reservoir tank 225B.

[0268] The circuit of the charging control unit 222 is electrically connected to both the charging socket 236 and the power distribution unit 213. The charging control unit 222 may be, for example, a power module or PLC (Programmable Logic Controller) having a microcomputer that executes a program based on a control signal from the control device 220, or may be a relay circuit that operates based on an electrical signal from the control device 220. The charging control unit 222 controls the charging voltage and charging current for the battery 204 when charging the battery 204 (including rapid charging). The charging control unit 222 adjusts the power received from the charging socket 236 and supplies it to the battery 204 as charging power.

[0269] In addition to the battery 204, the electric tractor is equipped with an electrical equipment battery 224 that supplies power to the control device 220 and other electrical equipment. The electrical equipment battery 224 is, for example, a lead battery. The electrical equipment battery 224 supplies low-voltage (for example, 12 volts) power to drive the electrical equipment. The output voltage of the electrical equipment battery 224 is lower than the output voltage of the battery 204.

[0270] The electrical component battery 224 is charged with power supplied from the battery 204 via the DC / DC converter 223. The DC / DC converter 223 can drop the voltage of the battery 204 to the voltage of the electrical component battery 224 and then supply power to the low-voltage electrical components. The DC / DC converter 223 can also supply power to the electrical component battery 224. That is, the DC / DC converter 223 is electrically connected to both the battery 204 and the electrical component battery 224, and can receive power from the battery 204, drop the voltage, and transmit the power to the electrical component battery 224. This allows the battery 204 to supply power to the electrical component battery 224 and charge it. In other words, the electrical component battery 224 can be charged with power received from the battery 204 via the DC / DC converter 223.

[0271] High-power equipment that receives high-voltage power from the battery 204 tends to become hot due to heat generation. For this reason, the electric tractor is equipped with a high-voltage equipment cooling device 226 for cooling the high-power equipment. The high-voltage equipment cooling device 226 includes a high-voltage equipment radiator 226A and pumps 226B and 226C. The pumps 226B and 226C are connected in series. The pumps 226B and 226C pump a refrigerant that cools the high-power equipment that operates on electric power, such as the inverters 214A and 214B, the electric motors M1 and M2, and the DC / DC converter 223. When the pumps 226B and 226C are operating, the refrigerant flows through the cooling passages in the high-power equipment, such as the inverters 214A and 214B, the electric motors M1 and M2, and the DC / DC converter 223, to cool the high-power equipment. The refrigerant heated by the high-power equipment is cooled by heat radiation in the high-voltage equipment radiator 226 A. The order of the cooling flow paths in the high-power equipment can be changed as appropriate.

[0272] As shown in FIGS. 20 and 21 , the high-voltage equipment radiator 226A and the battery radiator 225A are arranged side by side in front of the battery 204. A cooling fan 229 is provided behind the high-voltage equipment radiator 226A and the battery radiator 225A and in front of the battery 204. The cooling fan 229 generates cooling air to cool the refrigerant inside the high-voltage equipment radiator 226A and the battery radiator 225A. A front grille 212f (see FIG. 15 ) is provided in front of the hood 212, and outside air is introduced from in front of the battery radiator 225A as cooling air. The cooling fan 229 generates cooling air that flows rearward. The cooling air promotes heat dissipation from the battery radiator 225A and the high-voltage equipment radiator 226A.

[0273] 19 to 21, the battery 204 of this embodiment is configured by stacking two housings one above the other. The two housings are formed in the shape of a rectangular parallelepiped extending along the front-to-rear direction, and have right and left side surfaces that extend in a planar manner along the top-to-bottom and the front-to-back directions. The power distribution unit 213 is disposed adjacent to the side surfaces of the battery 204 that extend vertically.

[0274] Specifically, the power distribution unit 213 is supported on the left side surface of the lower one of the two housings of the battery 204 .

[0275] In addition to the power supply distribution unit 213, a reservoir tank 225B, a DC / DC converter 223, a battery for electrical equipment 224, etc. are supported on the left and right side portions of the battery 204. The reservoir tank 225B is located on the side of the side portion of the battery 204 where the power supply distribution unit 213 is located in the left-right direction and on a side portion above the power supply distribution unit 213 in the up-down direction. The DC / DC converter 223 is supported on the right side portion of the battery 204. The battery for electrical equipment 224 is supported on the right side portion of the right side portion of the battery 204 above the DC / DC converter 223. The DC / DC converter 223 and the battery for electrical equipment 224 are supported on the side portion of the side of the battery 204 opposite the side where the power supply distribution unit 213 is located in the left-right direction.

[0276] The power distribution unit 213 is provided at its front with a first electrical connection port 213A and a fifth electrical connection port 213E. The power distribution unit 213 is provided at its rear with a second electrical connection port 213B, a third electrical connection port 213C, and a fourth electrical connection port 213D. A power cable on the battery 204 side is connected to the first electrical connection port 213A. A power cable on the electric motor M1 side is connected to the second electrical connection port 213B. A power cable on the electric motor M2 side is connected to the third electrical connection port 213C. A power cable on the charging control unit 222 side (charging socket 236 side) is connected to the fourth electrical connection port 213D. A power cable on the DC / DC converter 223 side is connected to the fifth electrical connection port 213E. Each of the first electrical connection port 213A, the second electrical connection port 213B, the third electrical connection port 213C, the fourth electrical connection port 213D, and the fifth electrical connection port 213E is configured as a pair of connection ports, one for a positive pole and one for a negative pole.

[0277] 20 , the electric motors M1, M2 and the inverters 214A, 214B are offset toward the rear of the vehicle relative to the battery 204. In addition, positive and negative power supply connection ports are provided in the front of the battery 204. Therefore, the first power connection port 213A is located in the front of the power distribution unit 213, and the second, third, and fourth power connection ports 213B, 213C, and 213D are located in the rear of the power distribution unit 213. With this configuration, the power cables connected to the second, third, and fourth power connection ports 213B, 213C, and 213D, respectively, extend linearly rearward around the power distribution unit 213 without wrapping around it.

[0278] The fifth electrical connection port 213E is located above the first electrical connection port 213A in the front part of the power distribution unit 213. The electrical cable connected to the fifth electrical connection port 213E is connected to the DC / DC converter 223 located on the right side of the battery 204. The middle part of the electrical cable connected between the fifth electrical connection port 213E of the power distribution unit 213 and the DC / DC converter 223 is located between the cooling fan 229 and the battery 204 in the front-to-rear direction, and is located below the battery 204 and the cooling fan 229 in the up-down direction.

[0279] Fifth electrical connection port 213E is disposed at the front of power distribution unit 213. With this configuration, the vertical size of power distribution unit 213 is more compact than in a configuration in which second electrical connection port 213B, third electrical connection port 213C, fourth electrical connection port 213D, and fifth electrical connection port 213E are lined up one above the other at the rear of power distribution unit 213.

[0280] Each of inverters 214A, 214B is provided with a power receiving connection port 214C and a power supply connection port 214D. The power receiving connection port 214C of inverter 214A is connected to the current carrying cable connected to second current carrying connection port 213B. The power receiving connection port 214C of inverter 214B is connected to the current carrying cable connected to third current carrying connection port 213C. The power supply connection port 214D of inverter 214A is connected to the current carrying cable for electric motor M1. The power supply connection port 214D of inverter 214B is connected to the current carrying cable for electric motor M2.

[0281] The power receiving connection port 214C and the power supply connection port 214D are provided at the rear edges of the inverters 214A, 214B. DC power is supplied from the second power connection port 213B via a current carrying cable to the power receiving connection port 214C of the inverter 214A. AC power is supplied from the power supply connection port 214D of the inverter 214A via a current carrying cable to the electric motor M1. DC power is supplied from the third power connection port 213C via a current carrying cable to the power receiving connection port 214C of the inverter 214B. AC power is supplied from the power supply connection port 214D of the inverter 214B via a current carrying cable to the electric motor M2.

[0282] The power receiving connection port 214C and the power supply connection port 214D are provided on the side opposite to the side on which the loader attachment portion 208 is located. This prevents the front loader FA from coming into contact with the power cables connected to the power receiving connection port 214C and the power supply connection port 214D when the front loader FA is attached to the loader attachment portion 208.

[0283] 17 , a valve unit 228 is provided on the right side of the machine body 201, and hydraulic piping 228H extends forward and upward from the valve unit 228. In addition, hydraulic piping is provided on the right side of the front loader FA, and hydraulic piping 228H is connected to the hydraulic piping of the front loader FA. The main body of the valve unit 228 and hydraulic piping 228H are disposed on the right side of the battery 204, and the power distribution unit 213 is disposed on the left side of the battery 204. As a result, the piping of the hydraulic system of the front loader FA and the electrical cables connected to high-power devices such as inverters 214A and 214B are distributed to the left and right sides of the battery 204.

[0284] The power distribution unit 213 is configured to receive high-voltage power from the battery 204 and distribute it to the electric motors M1, M2, etc., and to receive charging power from the charging socket 236 and transmit it to the battery 204. For this reason, the power distribution unit 213 is configured to easily generate heat. For this reason, the power distribution unit 213 is placed adjacent to the battery 204 and in a position where it can be easily cooled.

[0285] The case of the power distribution unit 213 also has inclined wall portions 213f at both the top and bottom of the front. The upper inclined wall portion 213f is inclined upward toward the rear. The lower inclined wall portion 213f is inclined downward toward the rear. With this configuration, the vertical width of the front of the case of the power distribution unit 213 is formed to become smaller toward the front.

[0286] The front portion of the power distribution unit 213 is provided with a first electrical connection port 213A and a fifth electrical connection port 213E. The rear portion of the power distribution unit 213 is provided with a second electrical connection port 213B, a third electrical connection port 213C, and a fourth electrical connection port 213D. In other words, the number of connection ports provided in the front portion of the power distribution unit 213 is fewer than the number of connection ports provided in the rear portion of the power distribution unit 213. This configuration makes the vertical width of the front portion of the case of the power distribution unit 213 shorter than the vertical width of the rear portion of the case of the power distribution unit 213. This configuration makes it possible to provide inclined wall portions 213f at both the top and bottom of the front portion of the case of the power distribution unit 213.

[0287] The upper end (upper end of its rotation range) of the cooling fan 229 and the upper edge of the power distribution unit 213 are located at approximately the same vertical position. Also, the lower end (lower end of its rotation range) of the cooling fan 229 and the lower edge of the power distribution unit 213 are located at approximately the same vertical position. That is, the cooling fan 229 blows cooling air rearward across the range from the upper edge to the lower edge of the power distribution unit 213. As a result, the power distribution unit 213 is cooled by this cooling air across the upper edge and the lower edge.

[0288] In this way, the battery radiator 225A, the high-voltage equipment radiator 226A, and the cooling fan 229 are disposed in front of the battery 204 and the power supply distribution unit 213, and the cooling fan 229 is configured to generate cooling air that flows rearward. In other words, the cooling fan 229 is used both to cool the battery radiator 225A and the high-voltage equipment radiator 226A (to promote heat dissipation), and to cool the battery 204 and the power supply distribution unit 213 with the cooling air.

[0289] The cooling air from the cooling fan 229 is efficiently divided between the upper and lower edge portions of the power distribution unit 213 by the upper and lower inclined wall portions 213f.

[0290] The power distribution unit 213 is disposed adjacent to the fixed portion 212B in the left-right direction. As shown in Figure 21, in a side view of the machine body 201, the inclined portion of the inclined wall portion 213f is inclined along the inclined portion of the upper edge of the fixed portion 212B. As a result, in a side view of the machine body 201, the case of the power distribution unit 213 is located within the outer periphery of the fixed portion 212B. This allows the power distribution unit 213 to be securely protected by the fixed portion 212B.

[0291] A porous mesh portion 212m is formed in the fixed portion 212B. The power distribution unit 213 is disposed adjacent to the mesh portion 212m. As a result, the cooling air from the cooling fan 229 flows from the front grill 212f (see FIG. 15) through the battery radiator 225A, the high-voltage equipment radiator 226A, the cooling fan 229, and the power distribution unit 213, and then through the mesh portion 212m to the left of the aircraft.

[0292] [Alternatives to the Second Embodiment] Alternatives to the second embodiment will be described below. Matters other than those described in the following alternative embodiments are the same as those described in the above embodiment.

[0293] Other Embodiments The present invention is not limited to the configurations exemplified in the above-described embodiments, and other representative embodiments of the present invention will be exemplified below.

[0294] (1) In the above-described embodiment, the electric motor M1 for traveling and the electric motor M2 for work and hydraulic drive are configured as completely independent drive systems, but this is not limiting. For example, a clutch may be interposed between the power transmission mechanism 215A for traveling and the power transmission mechanism 215B for work, and the electric motor M1 for traveling may be configured to be able to assist the torque of the electric motor M2 for work. Furthermore, the electric motor M2 for work may be configured to be able to assist the torque of the electric motor M1 for traveling.

[0295] (2) In the above-described embodiment, the electric motor M2 is used for both work and hydraulic drive. However, the present invention is not limited to this embodiment, and the electric motor M2 may be configured to be used for either work or hydraulic drive.

[0296] (3) In the above-described embodiment, the battery 204 stores power for traveling, working, and hydraulic drive. This is not limiting, and for example, the battery 204 supported by the front frame 202 may be configured to store power for at least one of traveling, working, and hydraulic drive. In this case, a battery that stores power other than the at least one of these may be disposed elsewhere in the electric tractor.

[0297] (4) The hydraulic drive device is not limited to the front loader FA. The hydraulic drive device may be, for example, a container bucket, a pallet fork, a bale fork, a bale grab, a grader, a spreader (sprayer, spreader), a soil sample collection device, or the like.

[0298] (5) In the above-described embodiment, the hydraulic pipe 228H is disposed on the right side of the battery 204, and the power supply distribution unit 213 is disposed on the left side of the battery 204. A configuration in which the hydraulic pipe 228H is disposed on the left side of the battery 204, and the power supply distribution unit 213 is disposed on the right side of the battery 204, is also possible. In other words, the hydraulic pipe 228H may be disposed on one of the left and right sides of the battery 204, and the power supply distribution unit 213 may be disposed on the other of the left and right sides of the battery 204. Also, a configuration in which the main body of the valve unit 228 is disposed on one of the left and right sides of the battery 204, and the hydraulic pipe 228H extends from the valve unit 228 so as to be located on the other of the left and right sides of the battery 204, is also possible.

[0299] (6) The inclined wall portions 213f may not be provided at the top and bottom of the front part of the case of the power distribution unit 213. In this case, the vertical width of the front part of the case of the power distribution unit 213 may not be smaller than that of the front side.

[0300] (7) The power distribution unit 213 may not be provided with the fourth electrical connection port 213D. In this case, the charging socket 236 and the charging control unit 222 may be electrically connected to the battery 204 by an electrical cable of a separate charging system.

[0301] (8) The battery radiator 225A and the high-voltage equipment radiator 226A may be integrally formed.

[0302] The configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments, unless a contradiction occurs. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these, and can be modified as appropriate within the scope of the purpose of the present invention.

[0303] The present invention can be used in electric tractors.

[0304] (First embodiment) 1: Front wheel (traveling device) 2: Rear wheel (traveling device) 10: First battery (battery) 11: First motor (motor) 24: Junction box 27: Second battery 37: Voltage converter 58: Support frame A: Electric tractor G: Gap J1: First cooling path J2: Second cooling path N: Electrical equipment S1: First support portion S2: Second support portion W: Support mechanism

[0305] (Second embodiment) 201: body 204: battery 212: bonnet (cover member) 212A: swinging portion 212B: fixed portion 212m: mesh portion 213: power distribution unit (distribution unit) 213A: first energization connection port 213B: second energization connection port 213C: third energization connection port 213D: fourth energization connection port 225A: battery radiator (radiator) 226A: high-voltage equipment radiator (radiator) 228H: ​​hydraulic piping 229: cooling fan 236: charging socket M1: electric motor (first electric motor) M2: electric motor (second electric motor)

Claims

1. An electric tractor comprising a battery, a motor driven by electric power supplied from the battery, a traveling device driven by the motor, and a support mechanism having a first support portion and a second support portion, wherein the first support portion supports the battery and the second support portion supports electrical components.

2. The electric tractor according to claim 1, wherein the support mechanism has left and right support frames, each support frame is arranged in a posture along the side wall of the battery, and the battery is arranged at a position sandwiched between the left and right support frames.

3. The electric tractor according to claim 1 or 2, comprising a plurality of the batteries, wherein the first support portion supports the plurality of batteries.

4. The electric tractor according to claim 3, wherein the plurality of batteries are arranged side by side in the vertical direction.

5. The electric tractor according to claim 3 or 4, wherein a gap exists between the plurality of batteries.

6. An electric tractor comprising a first battery, a motor driven by electric power supplied from the first battery, a traveling device driven by the motor, and a plurality of electrical components, wherein the plurality of electrical components are arranged separately to the left and right of the first battery.

7. The electric tractor according to claim 6, wherein the plurality of electrical components include a second battery for auxiliary equipment, a voltage converter that steps down the electric power from the first battery and supplies it to the second battery, and a junction box, and the voltage converter and the junction box are arranged separately to the left and right of the first battery.

8. The electric tractor according to claim 7, comprising two of the first batteries, the two first batteries being arranged side by side in the vertical direction, and the voltage converter and the junction box both being arranged below the lower end position of the upper first battery.

9. The electric tractor according to claim 7 or 8, comprising a first cooling path and a second cooling path through which a coolant circulates, the first cooling path and the second cooling path being independent of each other, the voltage converter being included in the first cooling path, the first battery being included in the second cooling path, at least a part of the first cooling path passing through one of the left and right sides of the first battery, and at least a part of the second cooling path passing through the other of the left and right sides of the first battery.

10. The electric tractor according to any one of claims 6 to 9, comprising two of the first batteries, the two first batteries being arranged side by side in the vertical direction, and the plurality of electrical components being arranged by being vertically distributed with respect to the lower end position of the upper first battery.

11. An electric tractor comprising a battery for storing electric power, a first electric motor for driving for traveling that receives electric power supply from the battery, a second electric motor for at least one of working and hydraulic driving that receives electric power supply from the battery, and a distribution unit for distributing the electric power from the battery to each of the first electric motor and the second electric motor, the distribution unit being arranged adjacent to a side surface portion extending vertically in the battery.

12. The electric tractor according to claim 11, having a swing portion that can swing open and close and a fixed portion fixed below the swing portion, and including a cover member that covers the battery, a porous mesh portion being formed in the fixed portion, and the distribution unit being arranged adjacent to the mesh portion.

13. The electric tractor according to claim 11 or 12, wherein the distribution unit is provided with a first power connection port for connecting the power cable on the battery side, a second power connection port for connecting the power cable on the first electric motor side, and a third power connection port for connecting the power cable on the second electric motor side, the first electric motor and the second electric motor being displaced rearward of the body with respect to the battery, the first power connection port being located at the front of the distribution unit, and the second power connection port and the third power connection port being located at the rear of the distribution unit.

14. The electric tractor according to any one of claims 11 to 13, further comprising a charging socket for receiving received power for charging the battery, and the distribution unit is provided with a fourth energization connection port for connecting the energization cable on the charging socket side.

15. The electric tractor according to any one of claims 11 to 14, further comprising a radiator for cooling at least one of the battery, the first electric motor, and the second electric motor, and a cooling fan for generating cooling air. The radiator and the cooling fan are arranged in front of the battery and the distribution unit, and the cooling fan is configured to generate the cooling air flowing rearward.

16. The electric tractor according to claim 15, wherein an upper and lower width of a front portion of a case of the distribution unit is formed to be smaller toward the front side.

17. The electric tractor according to any one of claims 11 to 16, further comprising a hydraulic pipe connected to a hydraulic drive device driven based on driving of the second electric motor. The hydraulic pipe is arranged on one side, left or right, with respect to the battery, and the distribution unit is arranged on the other side, left or right, with respect to the battery.

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