Electric work vehicle

Abstract

Provided is an electric work vehicle in which a motor and a power control device can be connected while suppressing an increase in size of a housing. The electric vehicle is provided with a frame body which is arranged above the running vehicle body part in the vertical direction and accommodates the electric equipment. The power control device and the motor are disposed outside the housing and are connected by a high-voltage cable for power transmission. Therefore, the waterproof performance of the electrical equipment is ensured. In addition, the power control device and the motor can be directly connected through a high-voltage cable without penetrating through the frame body. Therefore, the motor and the power control device can be connected while the size of the frame body is restrained.

Description

Technical Field

[0001] The present invention relates to an electric work vehicle including a power control device that controls power supplied to an electric motor. Background Art

[0002] An electric work vehicle is known, which includes one or more electric motors, a travelable travel vehicle body portion, a power transmission portion that is mounted on the travel vehicle body portion and transmits power from the electric motor, a storage battery, and a power control device that controls power transmitted between the storage battery and the electric motor. For example, the electric tractor described in Patent Document 1 is such an electric work vehicle.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2023-66726 Summary of the Invention

[0006] However, when an electrical device is mounted on an electric work vehicle, for example, it is considered to house the electrical device in a housing. The electrical device is waterproofed by being mounted in the housing. At this time, since the housing is sealed for waterproofing, structures such as cables and connectors for connecting the inside and outside of the housing, holes for communicating the inside and outside of the housing, and metal grommets are required. On the other hand, since the electric motor is mechanically connected to the power transmission portion in order to transmit power to the power transmission portion and the travel vehicle body portion, it is disposed outside the housing. Therefore, if the power control device is housed in the housing, a structure in which a cable or the like for connecting the electric motor and the power control device penetrates from the inside to the outside of the housing while maintaining waterproof performance is required. When the electric motor and the power control device are connected by a high-voltage cable that is thicker and more rigid in shape than a low-voltage cable, there is a possibility that the structure for penetrating the housing becomes larger.

[0007] The present invention has been completed in view of the above circumstances, and an object thereof is to provide an electric work vehicle capable of connecting an electric motor and a power control device while suppressing enlargement of the housing.

[0008] The gist of the first invention is to provide an electric work vehicle, which (a) includes one or more electric motors, a travelable travel vehicle body portion, a power transmission portion that is mounted on the travel vehicle body portion and transmits power from the electric motor, a storage battery, and a power control device that controls power transmitted between the storage battery and the electric motor, wherein the electric work vehicle further includes: (b) an electrical device; and (c) a housing that is disposed above the travel vehicle body portion in the vertical direction and houses the electrical device, and (d) the power control device and the electric motor are disposed outside the housing and are connected by a high-voltage cable for power transmission.

[0009] According to the first invention, a housing for accommodating electrical equipment is provided above the vertical direction of the traveling vehicle body. A power control device and a motor are arranged outside the housing and connected by a high-voltage power transmission cable. Thereby, the waterproof performance of the electrical equipment is ensured. In addition, the power control device and the motor can be directly connected by the high-voltage cable without penetrating the housing. Therefore, the motor and the power control device can be connected while suppressing the enlargement of the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 FIG. is a diagram for explaining the schematic structure of an electric work vehicle to which the present invention is applied.

[0011] Figure 2 FIG. is a diagram for explaining an example of the arrangement of a waterproof box, a power control device, etc.

[0012] Figure 3 FIG. is a diagram for explaining an example of the electrical structure related to electrical equipment, a motor, etc.

[0013] Figure 4 FIG. is a diagram for explaining an example of a panel surrounding a dust-proof area. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0015]

Embodiment

[0016] Figure 1 FIG. is a diagram for explaining an example of the schematic structure of an electric tractor 10 as an example of an electric work vehicle to which the present invention is applied. Figure 1 (a) of FIG. is a left side view of the electric tractor 10. Figure 1 (b) of FIG. is a top view of the electric tractor 10. In addition, in Figure 1 (b) of FIG., the high-voltage battery 40 described later is removed for ease of explanation.

[0017] In Figure 1 , the electric tractor 10 includes a plurality of motors MG, a travelable vehicle body portion 20, a power transmission portion 30, a high-voltage battery 40, and a power control device PCU. The electric tractor 10 is, for example, an agricultural tractor.

[0018] The vehicle body portion 20 includes a tractor vehicle 22 and a vehicle frame 24. The tractor vehicle 22 is, for example, a known crawler tractor that can travel in a paddock. The vehicle frame 24 is fixedly provided to the chassis of the tractor vehicle 22. The electric tractor 10 is, for example, a full-track tractor.

[0019] The power transmission unit 30 is installed on the traveling vehicle body unit 20 and includes a traveling rotation transmission 32 and an operation transmission 34. The electric motor MG includes a traveling electric motor MGc, a rotation electric motor MGt, and an operation electric motor MGw.

[0020] The traveling electric motor MGc and the rotation electric motor MGt are respectively connected to the traveling rotation transmission 32 so as to be able to transmit power. The traveling rotation transmission 32 is connected to the tractor vehicle 22 so as to be able to transmit power. The traveling rotation transmission 32 transmits the power from the traveling electric motor MGc and the power from the rotation electric motor MGt to the tractor vehicle 22 respectively.

[0021] The operation electric motor MGw is connected to the operation transmission 34 so as to be able to transmit power. The operation transmission 34 is installed on the vehicle frame 24, and an operation machine (not shown) is installed as needed. This operation machine is, for example, a tiller, a plow, a fertilizer applicator, a lawn mower, a seeder, etc. The operation transmission 34 transmits the power from the operation electric motor MGw to this operation machine.

[0022] The high-voltage battery 40 is a chargeable and dischargeable DC power source, for example, a known secondary battery such as a nickel-metal hydride secondary battery or a lithium-ion battery. The high-voltage battery 40 is a battery that supplies power to the electric motor MG. The power control unit PCU is a device that controls the power exchanged between the high-voltage battery 40 and the electric motor MG.

[0023] The electric tractor 10 further includes an electrical device 50 and a waterproof box 60 that houses the electrical device 50. The electrical device 50 needs to be waterproof. The waterproof box 60 is a housing disposed above the traveling vehicle body unit 20, particularly in the vertical direction of the tractor vehicle 22. The waterproof box 60 has waterproof performance.

[0024] Figure 2 It is a diagram showing an example of the arrangement of the waterproof box 60, the power control unit PCU, etc. Figure 3 It is a diagram showing an example of the electrical structure related to the electrical device 50, the electric motor MG, etc.

[0025] In Figure 2 , Figure 3Among them, the electrical equipment 50 is electrical equipment and electronic equipment other than electrical equipment such as the motor MG that serves as a power source. For example, the electrical equipment 50 includes an AC charger 52, a distribution box 54, a DC-DC converter 56, an AC inverter 58, and a motor control device ECU. In addition, the electric tractor 10 further includes a charging cable 70, a charging socket 72, a power supply cable 74, a power supply socket 76, an auxiliary battery 78, a high-voltage power transmission cable 80 for power transmission, a low-voltage power transmission cable 82 for power transmission, and a low-voltage cable 84 for transmission, etc. The high-voltage power transmission cable 80 for power transmission is various high-voltage cables for power transmission. The low-voltage power transmission cable 82 for power transmission is various low-voltage cables for power transmission. The low-voltage cable 84 for transmission is various low-voltage cables for transmission.

[0026] The high-voltage battery 40 is connected to the AC charger 52, the power control unit PCU, and the distribution box 54 via the high-voltage power transmission cable 80 for power transmission, respectively. The high-voltage power transmission cable 80 for power transmission includes a high-voltage cable 80a, a high-voltage cable 80b, and a high-voltage cable 80c. The high-voltage cable 80a is a cable connecting the high-voltage battery 40 and the AC charger 52. The high-voltage cable 80b is a cable connecting the high-voltage battery 40 and the power control unit PCU. The high-voltage cable 80c is a cable connecting the high-voltage battery 40 and the distribution box 54.

[0027] The AC charger 52 is connected to the charging socket 72 via the charging cable 70. The charging socket 72 is provided on the vehicle frame 24 in a manner that can be connected to the charging connector 104, and the external charging cable 102 connected to an external power source 100 outside the electric tractor 10 has this charging connector 104. The charging socket 72 is a terminal for connecting to the charging connector 104 and for inputting the power supplied from the external power source 100, and is a charging port connected to the external power source 100. The charging cable 70 is also a kind of high-voltage cable.

[0028] The AC charger 52 is a charger that charges the high-voltage battery 40 with the power supplied from the external power source 100. The AC charger 52 converts the alternating current supplied from the external power source 100 into direct current, and boosts the voltage of the external power source 100 to the same voltage as the high-voltage battery 40 to charge the high-voltage battery 40.

[0029] The power stored in the high-voltage battery 40 is supplied to the motor MG via the power control unit PCU and others. In addition, when the charging connector 104 connected to the external power source 100 is connected to the charging socket 72, the power from the external power source 100 is supplied to the high-voltage battery 40 via the AC charger 52 and others. The electric tractor 10 is a tractor capable of charging the high-voltage battery 40 with the power from the external power source 100. The high-voltage battery 40 is a driving battery.

[0030] The power control unit PCU is connected to each motor MG via a high-voltage power transmission cable 80. The high-voltage power transmission cable 80 includes a high-voltage cable 80d, a high-voltage cable 80e, and a high-voltage cable 80f. The high-voltage cable 80d is a cable connecting the power control unit PCU and the traveling motor MGc. The high-voltage cable 80e is a cable connecting the power control unit PCU and the rotating motor MGt. The high-voltage cable 80f is a cable connecting the power control unit PCU and the working motor MGw.

[0031] The power control unit PCU includes an inverter having switching elements and the like. The power control unit PCU converts the direct current from the high-voltage battery 40 into an alternating current for driving each motor MG. In addition, the power control unit PCU may include a boost converter that boosts the voltage of the high-voltage battery 40 according to the voltage of the high-voltage battery 40 and supplies it to the inverter.

[0032] The distribution box 54 is connected to each of the DCDC converter 56 and the AC inverter 58 via the high-voltage power transmission cable 80. The high-voltage power transmission cable 80 includes a high-voltage cable 80g and a high-voltage cable 80h. The high-voltage cable 80g is a cable connecting the distribution box 54 and the DCDC converter 56. The high-voltage cable 80h is a cable connecting the distribution box 54 and the AC inverter 58.

[0033] The distribution box 54 supplies the power from the high-voltage battery 40 to each of the DCDC converter 56 and the AC inverter 58. That is, the DCDC converter 56 and the AC inverter 58 are respectively connected to the high-voltage battery 40 via the distribution box 54.

[0034] The DCDC converter 56 is connected to each of the auxiliary battery 78 and the motor control device ECU via a low-voltage power transmission cable 82. The DCDC converter 56 functions as a charging device that steps down the voltage of the high-voltage battery 40 to the same voltage as the auxiliary battery 78 and charges the auxiliary battery 78. The DCDC converter 56 and / or the auxiliary battery 78 supplies the power for operating the auxiliary equipment provided in the electric tractor 10, the motor control device ECU, and the like.

[0035] The AC inverter 58 is connected to the power supply socket 76 via the power supply cable 74. The AC inverter 58 converts the direct current supplied from the high-voltage battery 40 into an alternating current and steps down the voltage of the high-voltage battery 40 to the same voltage as, for example, the external power supply 100. The power supply socket 76 is provided on the vehicle frame 24 in a manner that allows the plug of an electrical device outside the electric tractor 10 to be connected. The power supply socket 76 is a terminal for supplying power to an electrical device outside the electric tractor 10 and is a power supply port connected to an external electrical device. The power supply cable 74 is also a type of high-voltage cable.

[0036] The motor control device ECU is connected to each of the power control device PCU and the motors MG via the low-voltage transmission cable 84. The low-voltage transmission cable 84 includes a low-voltage cable 84a, a low-voltage cable 84b, a low-voltage cable 84c, and a low-voltage cable 84d. The low-voltage cable 84a is the cable connecting the motor control device ECU and the power control device PCU. The low-voltage cable 84b is the cable connecting the motor control device ECU and the traveling motor MGc. The low-voltage cable 84c is the cable connecting the motor control device ECU and the rotating motor MGt. The low-voltage cable 84d is the cable connecting the motor control device ECU and the working motor MGw.

[0037] The motor control device ECU is an electronic control device that outputs a command signal to the power control device PCU via the low-voltage cable 84a to drive the power control device PCU. For example, the motor control device ECU outputs a command signal for driving the motor MG according to the output demand value corresponding to the needs of the operator. Detection signals such as the rotational speed and temperature of each motor MG are supplied from various sensors provided in the motor MG to the motor control device ECU via the low-voltage cable 84b, the low-voltage cable 84c, and the low-voltage cable 84d.

[0038] Electrical devices 50 such as an AC charger 52, a distribution box 54, a DC-DC converter 56, an AC inverter 58, and a motor control device ECU are mounted on the electric tractor 10. Therefore, a waterproof box 60 is provided on the electric tractor 10, and the electrical devices 50 are waterproofed by being mounted in the waterproof box 60. On the other hand, the motor MG serving as the prime mover of the electric tractor 10 is mechanically connected to the power transmission unit 30 in order to transmit power to the power transmission unit 30 and the tractor vehicle 22. Therefore, the motor MG is arranged outside the waterproof box 60. In addition, in order to supply power, the motor MG is connected to the power control device PCU by high-voltage cables 80d, 80e, and 80f. On the other hand, the high-voltage power transmission cable 80 has a thicker wire diameter and higher rigidity than the low-voltage power transmission cable 82 and the low-voltage transmission cable 84. In addition, the connectors or terminal blocks used in the high-voltage power transmission cable 80 are larger than the connectors or terminal blocks used in the low-voltage power transmission cable 82 and the low-voltage transmission cable 84.

[0039] Here, since the waterproof box 60 is sealed for waterproofing, structures such as cables for connecting the inside and outside of the waterproof box 60, the arrangement of connectors, holes for communicating the inside and outside of the waterproof box 60, and metal grommets are required. Therefore, if the power control unit PCU is housed in the waterproof box 60, large metal grommets for allowing the high-voltage cables 80d, 80e, 80f, and large terminal blocks to penetrate from the inside to the outside of the waterproof box 60 while maintaining the waterproof performance need to be provided and disposed. If so, there is a possibility that structures for penetrating the waterproof box 60 and the like become large-sized.

[0040] Therefore, in order to connect the motor MG and the power control unit PCU while suppressing the enlargement of the waterproof box 60, the power control unit PCU is arranged outside the waterproof box 60 in the same manner as the motor MG (refer to Figures 1-3 ). In the electric tractor 10, the inside of the waterproof box 60 is a waterproof-required area (= waterproof-required area) that requires waterproof performance. The electric tractor 10 has a non-waterproof (dust-proof) area that does not require waterproofing but has dust-proof performance. In the present embodiment, the non-waterproof (dust-proof) area is referred to as a dust-proof area (= dust-proof area) 90. The dust-proof area 90 is provided above the traveling vehicle body portion 20, particularly above the tractor vehicle 22 in the vertical direction and adjacent to the waterproof box 60 in the horizontal direction. The power control unit PCU is provided above the traveling vehicle body portion 20, particularly above the tractor vehicle 22 in the vertical direction and adjacent to the waterproof box 60 in the horizontal direction. The power control unit PCU has a simple waterproof function as a single unit and is arranged in the dust-proof area 90. In addition, the high-voltage battery 40 also has a simple waterproof function as a single unit, and the area where the high-voltage battery 40 is arranged is also a dust-proof area.

[0041] Refer to Figure 2 , the charging cable 70, the power supply cable 74, and the high-voltage cables 80a (and 80c) among the high-voltage cables communicate between the inside and outside of the waterproof box 60 via the high-voltage metal grommets 86. The high-voltage cables 80b, 80d, 80e, 80f among the high-voltage cables are arranged outside the waterproof box 60. The power transmission low-voltage cable 82 and the transmission low-voltage cable 84 communicate between the inside and outside of the waterproof box 60 via the low-voltage metal grommets 88.

[0042] Figure 4 is a diagram showing an example of the panel 92 surrounding the dust-proof area 90. Figure 4 (a) of Figure 4 is a left side view of the electric tractor 10. Figure 4 (b) of

[0043] In Figure 4In this case, the electric tractor 10 includes a panel 92 (refer to the wire mesh part) configured to surround the dust-proof area 90. The panel 92 includes a side panel 92a, a rear panel 92b, and a bottom panel 92c. The side panel 92a is disposed on the left side in the horizontal direction of the dust-proof area 90. The rear panel 92b is disposed at the rear in the horizontal direction of the dust-proof area 90. The bottom panel 92c is disposed below in the vertical direction of the dust-proof area 90. The right side and the front in the horizontal direction of the dust-proof area 90 are surrounded by the waterproof box 60. The side panel 92a and the rear panel 92b are panels disposed around the horizontal direction of the dust-proof area 90 except on the side of the waterproof box 60. The bottom panel 92c is a panel disposed below in the vertical direction of the dust-proof area 90. The high-voltage battery 40 is disposed adjacent to the power control unit PCU above in the vertical direction (refer to Figure 1 ). Therefore, the upper part in the vertical direction of the dust-proof area 90 is surrounded by the high-voltage battery 40. The dust-proof area 90 is surrounded by the panel 92, the waterproof box 60, and the high-voltage battery 40.

[0044] As described above, according to the present embodiment, there is provided a waterproof box 60 that houses the electrical equipment 50 and is disposed above the traveling vehicle body part 20 in the vertical direction. The power control unit PCU and the motor MG are disposed outside the waterproof box 60 and are connected by high-voltage cables 80d, 80e, and 80f. Thereby, the waterproof performance of the electrical equipment 50 is ensured. In addition, the power control unit PCU and the motor MG can be directly connected by high-voltage cables without penetrating the waterproof box 60. For example, there is no need to provide a large metal hole for penetrating the waterproof box 60. Therefore, the motor MG and the power control unit PCU can be connected while suppressing the enlargement of the waterproof box 60.

[0045] In addition, according to the present embodiment, the power control unit PCU is disposed adjacent to the waterproof box 60 horizontally above the traveling vehicle body part 20 in the vertical direction. Thereby, the cable for connecting the power control unit PCU and the inside of the waterproof box 60 is shortened. In addition, there is provided a dust-proof area 90 that is disposed adjacent to the waterproof box 60 horizontally above the traveling vehicle body part 20 in the vertical direction. The power control unit PCU is disposed in the dust-proof area 90. Thereby, the dust-proof performance of the power control unit PCU is ensured.

[0046] In addition, according to the present embodiment, the high-voltage battery 40 is disposed adjacent to the power control unit PCU above in the vertical direction. There are provided a bottom panel 92c disposed below in the vertical direction of the dust-proof area 90 and a side panel 92a and a rear panel 92b disposed around the horizontal direction of the dust-proof area 90 except on the side of the waterproof box 60. Thereby, the dust-proof area 90 where the power control unit PCU is disposed, that is, the non-waterproof area, prevents impacts of mud, water, flying stones, etc.

[0047] In addition, according to the present embodiment, the motor control unit ECU, the power control unit PCU, and the motor MG housed in the waterproof case 60 are connected by the transmission low-voltage cable 84. Thus, the waterproof performance of the motor control unit ECU is ensured. In addition, by providing a small low-voltage metal eyelet 88 for passing through the waterproof case 60, the motor control unit ECU, the power control unit PCU, and the motor MG can be connected.

[0048] As mentioned above, although the embodiment of the present invention is described in detail based on the drawings, the present invention can also be applied in other aspects.

[0049] For example, in the above-mentioned embodiment, a full-track tractor is exemplified as the electric tractor 10, but the present invention is not limited to this form. For example, the electric tractor 10 may also be a half-track tractor, a wheeled tractor, or the like.

[0050] In addition, in the above-mentioned embodiment, as the electric motor MG, the traveling electric motor MGc, the rotating electric motor MGt, and the working electric motor MGw are exemplified, but the present invention is not limited to this mode. For example, the electric motor MG may also be a single electric motor. In this case, for example, an electric motor connected to the working gearbox 34 in a manner that can transmit power may be provided, and an engine may be provided as a power source connected to the traveling rotating gearbox 32 in a manner that can transmit power. The electric working vehicle may be a tractor having a power source including at least an electric motor.

[0051] The above is ultimately one embodiment, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art.

[0052] (Explanation of symbols)

[0053] 10: Electric tractor (Electric work vehicle); 20: Traveling body; 30: Power transmission unit; 40: High-voltage battery (Battery); 50: Electrical equipment; 60: Waterproof box (Frame); 80: High-voltage cable for power transmission (High-voltage cable for power transmission); 84: Low-voltage cable for transmission (Low-voltage cable for transmission); 90: Dust-proof area (Dust-proof area); 92: Panel; 92a: Side panel (Panel); 92b: Rear panel (Panel); 92c: Lower panel (Panel); ECU: Motor control unit (Electronic control unit); MG: Motor; PCU: Power control unit.

Claims

1. An electric work vehicle (10), comprising: One or more electric motors (MG, MGc, MGt, MGw), a drivable traveling vehicle body portion (20), a power transmission portion (30) mounted on the traveling vehicle body portion (20) for transmitting power from the electric motors (MG, MGc, MGt, MGw), a storage battery (40), and a power control device (PCU) for controlling the power transmitted between the storage battery (40) and the electric motors (MG, MGc, MGt, MGw). It is characterized in that The electric work vehicle (10) further comprises: Electrical equipment (50, 52, 54, 56, 58, ECU); and A housing (60) disposed above the traveling vehicle body portion (20) in the vertical direction and accommodating the electrical equipment (50, 52, 54, 56, 58, ECU). The power control device (PCU) and the electric motors (MG, MGc, MGt, MGw) are disposed outside the housing (60) and connected by high-voltage cables (80, 80a, 80b, 80c, 80d, 80e, 80f) for power transmission.

2. The electric work vehicle (10) according to claim 1, characterized in that: The power control device (PCU) is disposed above the traveling vehicle body portion (20) in the vertical direction and adjacent thereto in the horizontal direction with respect to the housing (60).

3. The electric work vehicle (10) according to claim 2, characterized in that: The electric work vehicle (10) further comprises a dust-proof area (90) disposed above the traveling vehicle body portion (20) in the vertical direction and adjacent thereto in the horizontal direction with respect to the housing (60). The power control device (PCU) is disposed in the dust-proof area (90). The storage battery (40) is disposed adjacent to the power control device (PCU) above it in the vertical direction. The electric work vehicle (10) further comprises panels (92, 92a, 92b, 92c) disposed below the dust-proof area (90) in the vertical direction and around the dust-proof area (90) in the horizontal direction except on the side of the housing (60).

4. The electric work vehicle (10) according to claim 1, characterized in that: The electrical equipment (50, 52, 54, 56, 58, ECU) includes an electronic control unit (ECU) for driving the power control device (PCU). The electronic control unit (ECU) is connected to the power control device (PCU) and the electronic control unit (ECU) is connected to the electric motors (MG, MGc, MGt, MGw) respectively by low-voltage cables (84, 84a, 84b, 84c, 84d) for transmission.

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