Electric work vehicle

Abstract

To provide an electric work vehicle which reduces a situation disadvantageous for normal power supply of a battery, in a state where a radiator and a cooling fan are provided in front of the battery.SOLUTION: An electric work vehicle includes a battery 4 provided in front of a machine body, an inverter 14 to which power of the battery 4 is supplied, and a motor M driven by power from the inverter 14. A cover member 12 is provided in which an introduction part 21 to which outside air is introduced is provided on a front part 12. Between the introduction part 21 inside the cover member 12 and the front part of the battery 4, a radiator 1 which produces cooling water for cooling the motor M and is provided in the vertical direction and the front-and-back direction, and a cooling fan 7a which is provided adjacent to the radiator 1 so as to be rotatable around a shaft core P1 in the right-and-left direction are provided.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] As disclosed in Patent Document 1, some electric work vehicles are equipped with a battery located at the front of the vehicle body and an inverter to which power from the battery is supplied, and are configured so that the motor is driven by power from the inverter. In Patent Document 1, a battery is housed in a cover member, and a radiator that produces coolant for cooling the motor and a cooling fan are provided in an area in front of the battery inside the cover member. [Prior art documents] [Patent documents]

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

[0004] In the electric work vehicle of Patent Document 1, as the vehicle body moves forward, outside air is introduced into the interior of the cover member mainly from the front part of the cover member, passes through the radiator due to the action of the cooling fan, and the hot air flows from the cooling fan to the battery at the rear. Batteries often have an upper limit temperature set for the temperature at which they can normally supply power. For example, when working in the summer, if hot air from the radiator flows toward the battery, the battery temperature may reach the upper limit.

[0005] The present invention aims to reduce situations that are unfavorable to the normal power supply of the battery when the radiator and cooling fan are provided in front of the battery in an electric work vehicle. [Means for solving the problem]

[0006] The electric work vehicle of the present invention comprises a battery provided at the front of the vehicle body, an inverter to which power from the battery is supplied, a motor driven by power from the inverter, a traveling device driven by the motor, a cover member that houses the battery and has an intake section at the front that introduces outside air, and a radiator that produces cooling water to cool the motor and is provided along the up-down and front-rear directions between the intake section inside the cover member and the front of the battery, and a cooling fan that is provided adjacent to the radiator and can rotate around an axis that is along the left-right direction. and an oil cooler arranged along the vertical and longitudinal directions, the radiator being arranged on the side closer to the lateral portion of the cover member, and the oil cooler being arranged on the opposite side of the lateral portion of the cover member from the radiator.

[0007] According to the present invention, when outside air is introduced into the inside of the cover member through the introduction part of the cover member as the aircraft moves forward, the air introduced into the inside of the cover member passes through the radiator due to the action of the cooling fan and flows in the left-right direction from the radiator, and is less likely to flow into the battery behind the radiator. This reduces the flow of high-temperature air from the radiator toward the battery, reducing situations that are unfavorable to the battery's normal power supply and improving the durability of the battery. Electric work vehicles are sometimes provided with an oil cooler for the hydraulic oil used in the hydraulic equipment mounted on the vehicle, and are sometimes configured so that air from a cooling fan is supplied to the oil cooler. According to the present invention, even if an oil cooler is installed, the flow of high-temperature air from the radiator and oil cooler toward the battery can be reduced, which is advantageous in terms of improving the durability of the battery. In the present invention, it is preferable that the radiator, the cooling fan, and the oil cooler are arranged so that the cooling fan is positioned between the radiator and the oil cooler, the radiator is arranged on the side closer to the lateral portion of the cover member relative to the cooling fan, and the oil cooler is arranged on the opposite side of the radiator relative to the cooling fan. According to the present invention, air flows in the order of the radiator, cooling fan, and oil cooler in the left-right direction, or the oil cooler, cooling fan, and radiator in the left-right direction, thereby improving the efficiency of heat exchange in the radiator and oil cooler.

[0008] In the present invention, it is preferable that the radiator generates cooling water for cooling the motor and cooling water for cooling the inverter.

[0009] In an electric work vehicle, the radiator is sometimes configured with a sufficient capacity so that the motor and inverter are cooled by the cooling water from the radiator. According to the present invention, even if the radiator is configured to have a sufficient capacity, it is possible to reduce the amount of high-temperature air flowing from the radiator toward the battery, which is advantageous in terms of improving the durability of the battery.

[0010] In the present invention, it is preferable that a lateral ventilation portion that allows ventilation is provided in a portion of the lateral portion of the cover member that faces the radiator.

[0011] According to the present invention, if the lateral ventilation portion of the cover member is located upstream of the air flow in the left-right direction caused by the cooling fan, in addition to external air being introduced into the interior of the cover member from the introduction portion of the cover member as the aircraft moves forward, external air is introduced into the interior of the cover member through the lateral ventilation portion of the cover member, and a large amount of external air is supplied to the radiator. This improves the efficiency of heat exchange in the radiator, reducing the temperature of the air passing through the radiator, which is advantageous in terms of improving the durability of the battery.

[0012] According to the present invention, if the lateral ventilation portion of the cover member is located downstream of the air flow in the left-right direction caused by the cooling fan, the air that has passed through the radiator can easily escape to the outside through the lateral ventilation portion of the cover member. This improves the efficiency of heat exchange in the radiator, reducing the amount of high-temperature air from the radiator that flows toward the battery, which is advantageous in terms of improving battery durability.

[0013]

[0014]

[0015]

[0016] [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is a left side view of the tractor. [Figure 2]FIG. 2 is a left side view showing the arrangement of an inverter and the like. [Figure 3] FIG. 2 is a diagram illustrating a flow of power transmission. [Figure 4] FIG. [Figure 5] FIG. 4 is a left side view of the vicinity of the battery and the radiator inside the cover member. [Figure 6] FIG. 4 is a front view of the vicinity of the battery and the radiator inside the cover member. [Figure 7] FIG. 4 is a plan view of the battery, the radiator, and the surrounding area inside the cover member. [Figure 8] FIG. 10 is a front view of the vicinity of the battery and the radiator inside the cover member in the second modified embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of the present invention will be described with reference to the drawings. In the following description, unless otherwise specified, the direction of arrow F in the drawings will be referred to as "front," the direction of arrow B as "rear," the direction of arrow L as "left," and the direction of arrow R as "right." Furthermore, the direction of arrow U in the drawings will be referred to as "up," and the direction of arrow D as "down."

[0019] [Overall configuration of the tractor] The tractor of this embodiment will be described below. As shown in Fig. 1, the tractor has left and right front wheels 10, left and right rear wheels 11, and a cover member 12.

[0020] The tractor also includes a machine body frame 2 and a driving section 3. The machine body frame 2 is supported by left and right front wheels 10 and left and right rear wheels 11.

[0021] The cover member 12 is disposed at the front of the vehicle body, and the driving section 3 is provided behind the cover member 12. In other words, the cover member 12 is disposed in front of the driving section 3.

[0022] The driver's section 3 has a protective frame 30, a driver's seat 31, and a steering wheel 32. An operator can sit in the driver's seat 31. This allows the operator to get into the driver's section 3. The left and right front wheels 10 are steered by operating the steering wheel 32. The operator can perform various driving operations in the driver's section 3.

[0023] The tractor is equipped with a traction battery 4. The cover member 12 is configured to be swingable about an opening / closing axis Q that extends in the left-right direction of the vehicle body. This allows the cover member 12 to be opened and closed. When the cover member 12 is in the closed state, the traction battery 4 is covered by the cover member 12.

[0024] As shown in Fig. 2, the tractor includes an inverter 14 and a motor M. The traction battery 4 supplies power to the inverter 14. The inverter 14 converts DC power from the traction battery 4 into AC power and supplies it to the motor M. The motor M is then driven by the AC power supplied from the inverter 14.

[0025] 2 and 3, the tractor is equipped with a hydrostatic continuously variable transmission 15 and a transmission 16. As shown in Fig. 3, the hydrostatic continuously variable transmission 15 has a hydraulic pump 15a and a hydraulic motor 15b.

[0026] The hydraulic pump 15a is driven by rotational power from the motor M. When the hydraulic pump 15a is driven, rotational power is output from the hydraulic motor 15b. The hydrostatic continuously variable transmission 15 is configured so that the speed of the rotational power is changed between the hydraulic pump 15a and the hydraulic motor 15b. The hydrostatic continuously variable transmission 15 is also configured so that the gear ratio can be changed continuously.

[0027] The rotational power output from the hydraulic motor 15b is transmitted to the transmission 16. The rotational power transmitted to the transmission 16 is changed in speed by a gear-type speed change mechanism of the transmission 16 and distributed to the left and right front wheels 10 and the left and right rear wheels 11. In this way, the left and right front wheels 10 and the left and right rear wheels 11 are driven.

[0028] 2 and 3, the tractor is equipped with a mid PTO shaft 17 and a rear PTO shaft 18. The rotational power output from the motor M is distributed to the hydraulic pump 15a, the mid PTO shaft 17, and the rear PTO shaft 18. This causes the mid PTO shaft 17 and the rear PTO shaft 18 to rotate.

[0029] If a working device is connected to the mid PTO shaft 17 or the rear PTO shaft 18, the working device will be driven by the rotational power of the mid PTO shaft 17 or the rear PTO shaft 18. For example, as shown in FIG. 2, in this embodiment, a brush cutting device 19 is connected to the mid PTO shaft 17. The brush cutting device 19 is driven by the rotational power of the mid PTO shaft 17.

[0030] [Configuration of cover member] 1 and 2, the right and left body frames 2 and the transmission 16 are connected to form a body as the skeleton of the tractor, which is made up of the body frames 2 and the transmission 16. A traction battery 4 (hereinafter referred to as the battery 4) is mounted on the front of the body, and the battery 4 is housed in a cover member 12 in a closed state.

[0031] As shown in Fig. 4, the cover member 12 is configured to have a front portion 12a, right and left side portions 12b, and an upper portion 12c. A headlamp 20 and a ventilated lattice-shaped front grille 21 (corresponding to an introduction portion) are provided on the front portion 12a of the cover member 12, and ventilated lattice-shaped side grilles 22 (corresponding to lateral ventilation portions), 23 are provided on the right and left side portions 12b of the cover member 12. As the aircraft moves forward, outside air is introduced into the interior of the cover member 12 mainly through the front grille 21.

[0032] [Battery Configuration] As shown in Figures 5, 6, and 7, the battery 4 contains multiple stacks (not shown) each made up of multiple battery modules (not shown) connected together, and connection portions 4a, 4b, 4c, and 4d are provided at the front of the battery 4.

[0033] A connection part 13 to which a charger (not shown) for an external power supply (not shown) is connected is provided on the left front part of the battery 4, and a harness 24 is connected between the connection part 4a of the battery 4 and the connection part 13. Power from the external power supply is supplied to the connection part 4a of the battery 4 via the connection part 13 and the harness 24, and the battery 4 is charged. A harness 25 is connected between the connection portion 4b of the battery 4 and the inverter 14, and power is supplied from the connection portion 4b of the battery 4 to the inverter 14.

[0034] The DC-DC converter 5 and the battery 6 are provided along the vertical and longitudinal directions between the front grille 21 and the front part of the battery 4 inside the cover member 12. A harness 26 is connected between the connection part 4c of the battery 4 and the DC-DC converter 5, so that the power of the battery 4 is supplied to the DC-DC converter 5, and the power reduced to 12 V by the DC-DC converter 5 is supplied to the battery 6.

[0035] A harness 27 is connected between the connection part 4d of the battery 4 and the battery 6, and the 12V power of the battery 6 is supplied to the battery 4. Various devices (not shown) equipped on the tractor are operated by the 12V power of the battery 4.

[0036] [Configuration of the radiator and its vicinity] As shown in Figures 5, 6, and 7, the radiator 1 is provided inside the cover member 12 between the front grille 21 and the front of the battery 4, on the left side of the DC-DC converter 5 and the battery 6, along the vertical and longitudinal directions.

[0037] A fan device 7 is provided inside the cover member 12 between the front grille 21 and the front part of the battery 4, and between the radiator 1 and the DC-DC converter 5, along the vertical and front-rear directions.

[0038] The right and left side grilles 22 described above are provided on the right and left lateral portions 12b of the cover member 12 at portions facing the radiator 1. A stay 28 is connected across the rear portion of the upper part of the radiator 1 and the front portion of the battery 4, and the connection portion 13 described above is supported by the stay 28.

[0039] The fan device 7 is provided with a cooling fan 7a that can rotate around an axis P1 that runs along the left-right direction, an electric motor (not shown) that drives and rotates the cooling fan 7a, and a fan shroud 7b that covers the cooling fan 7a and the electric motor, and the electric motor is driven by 12V power from the battery 4. The fan shroud 7b of the fan device 7 is connected to the radiator 1, and the fan device 7 (cooling fan 7a) is provided adjacent to the radiator 1.

[0040] An oil cooler 8 is provided along the vertical and longitudinal directions inside the cover member 12 between the front grille 21 and the front part of the battery 4, and between the fan device 7 and the DC-DC converter 5. The oil cooler 8 is for cooling the hydraulic oil of the hydrostatic continuously variable transmission 15 and the hydraulic oil of other hydraulic equipment (not shown).

[0041] Thus, the radiator 1, the fan device 7 (cooling fan 7a), and the oil cooler 8 are provided such that the fan device 7 (cooling fan 7a) is disposed between the radiator 1 and the oil cooler 8.

[0042] [Radiator cooling configuration] 5, 6, and 7, a water pump 9 is provided between the right and left body frames 2, and is driven by 12V power from the battery 4. A pipe 29 connects the lower part of the radiator 1 to the water pump 9, and a pipe 33 connects the water pump 9 to the inverter 14.

[0043] A pipe 34 is connected between the inverter 14 and the motor M, and a pipe 35 is connected between the motor M and the DC-DC converter 5. A pipe 36 is connected between the DC-DC converter 5 and the upper part of the radiator 1, and a water supply port 37 is provided in the pipe 36.

[0044] When the water pump 9 is driven, the cooling water generated in the radiator 1 is supplied to the inverter 14 via the pipe 29, the water pump 9, and the pipe 33. The cooling water that has passed through the inside of the inverter 14 is supplied to the motor M via the pipe 34, and the cooling water that has passed through the inside of the motor M is supplied to the DC-DC converter 5 via the pipe 35.

[0045] The cooling water that has passed through the inside of the DC-DC converter 5 returns to the radiator 1 via the pipe 36, and the cooling water produced in the radiator 1 cools the motor M, the inverter 14, and the DC-DC converter 5. As a result, the radiator 1 generates cooling water for cooling the motor M, cooling water for cooling the inverter 14, and cooling water for cooling the DC-DC converter 5.

[0046] [Fan device operating status] 5, 6, and 7, as the aircraft moves forward, external air is introduced into the interior of the cover member 12 mainly through the front grill 21. When the cooling fan 7a of the fan device 7 is driven to rotate, an air flow is generated between the front grill 21 and the front part of the battery 4 inside the cover member 12 in the left-right direction.

[0047] Most of the air introduced into the cover member 12 through the front grille 21 is supplied to the radiator 1 from the left side of the radiator 1. In addition, external air is introduced into the cover member 12 through the left side grille 22 of the cover member 12 and is supplied to the radiator 1 from the left side of the radiator 1.

[0048] The air that passes through the radiator 1 flows to the right from the fan device 7 (cooling fan 7a) through the oil cooler 8, passing around the DC-DC converter 5 and the battery 6, and exiting the cover member 12 mainly through the right side grill 22 of the cover member 12. As a result, a large amount of outside air is supplied to the radiator 1, and the air that has passed through the radiator 1 does not easily flow to the battery 4 behind the radiator 1.

[0049] [First Alternative Embodiment of the Invention] 5, 6, and 7, the cooling fan 7a of the fan device 7 may be configured to rotate so that air flows from right to left between the front grille 21 and the front of the battery 4 inside the cover member 12.

[0050] According to this configuration, the cooling fan 7a of the fan device 7 introduces external air into the interior of the cover member 12 through the right side grill 22 of the cover member 12. Most of the air introduced into the interior of the cover member 12 through the front grill 21 and the right side grill 22 of the cover member 12 passes, in this order, around the battery 6, around the DC-DC converter 5, the oil cooler 8, the fan device 7 (cooling fan 7a), and the radiator 1, and exits to the outside of the cover member 12 mainly through the left side grill 22 of the cover member 12.

[0051] In this case, the air introduced into the cover member 12 through the front grille 21 includes air that enters from the front between the DC-DC converter 5 and the oil cooler 8, passes through the oil cooler 8, and flows to the fan device 7 (cooling fan 7a), and air that enters from the front between the oil cooler 8 and the fan device 7 (cooling fan 7a) and flows to the fan device 7 (cooling fan 7a).

[0052] [Second Alternative Embodiment of the Invention] As shown in FIG. 8, the fan device 7 (cooling fan 7a) may be provided on the left side of the radiator 1.

[0053] In the configuration shown in Figure 8, when the cooling fan 7a of the fan device 7 generates an air flow in the left-to-right direction, most of the air that is introduced into the inside of the cover member 12 through the front grille 21 and the left side grille 22 of the cover member 12 passes through the fan device 7 (cooling fan 7a), the radiator 1, the oil cooler 8, the periphery of the DC-DC converter 5, and the periphery of the battery 6, in that order, and exits to the outside of the cover member 12 mainly through the right side grille 22 of the cover member 12.

[0054] In the configuration shown in Figure 8, when air flows from right to left in the left-right direction due to the cooling fan 7a of the fan device 7, most of the air introduced into the inside of the cover member 12 through the front grille 21 and the right side grille 22 of the cover member 12 passes around the battery 6, around the DC-DC converter 5, the oil cooler 8, the radiator 1, and the fan device 7 (cooling fan 7a), in that order, and exits to the outside of the cover member 12 mainly through the left side grille 22 of the cover member 12.

[0055] In this case, the air introduced into the inside of the cover member 12 through the front grille 21 includes air that enters from the front between the DC-DC converter 5 and the oil cooler 8, passes through the oil cooler 8, and flows to the radiator 1, as well as air that enters from the front between the oil cooler 8 and the radiator 1 and flows to the radiator 1.

[0056] [Third Alternative Embodiment of the Invention] The DC-DC converter 5 and the battery 6 may be provided at positions other than those shown in FIGS. With this configuration, when the cooling fan 7a of the fan device 7 is driven to rotate, and air flows in the left-right direction between the front grille 21 inside the cover member 12 and the front part of the battery 4, the DC-DC converter 5 and the battery 6 do not obstruct the air flow.

[0057] [Fourth Alternative Embodiment of the Invention] 5 to 8, the left lateral portion 12b of the cover member 12 does not necessarily need to be provided with the side grille 22. According to this configuration, outside air is introduced into the inside of the cover member 12 mainly through the front grille 21, and the air introduced into the inside of the cover member 12 passes through the radiator 1, etc., and then exits to the outside of the cover member 12 through the right side grille 22, the bottom of the cover member 12, etc.

[0058] [Fifth Alternative Embodiment of the Invention] 5 to 8, the side grille 22 does not necessarily have to be provided on the right lateral portion 12b of the cover member 12. According to this configuration, the air introduced into the inside of the cover member 12 from the front grille 21 and the left side grille 22 passes through the radiator 1, etc., and then exits the cover member 12 from the left side grille 22, the bottom of the cover member 12, etc.

[0059] [Sixth Alternative Embodiment of the Invention] The front wheels 10 and rear wheels 11 are the traveling devices of the present invention. Instead of the front wheels 10 and rear wheels 11, right and left crawler traveling devices (not shown) may be provided on the machine body as the traveling devices. [Industrial Applicability]

[0060] The present invention can be applied not only to tractors but also to other electric work vehicles such as electric carts and transport vehicles, and can also be applied to autonomous or radio-controlled electric work vehicles that do not have an operator on board. [Explanation of symbols]

[0061] 1 radiator 4 Battery 7a Cooling fan 8 Oil cooler 10 Front wheels (running gear) 11 Rear wheels (running gear) 12 Cover member 12a front 12b Side part 14 Inverter 21 Front grille (introduction part) 22 Side grill (horizontal ventilation part) Medium motor P1 axis center

Claims

1. A battery provided at the front of the aircraft; an inverter supplied with power from the battery; a motor driven by power from the inverter; a traveling device driven by the motor; a cover member that houses the battery and has an intake portion at the front for introducing external air, Between the introduction portion and the front portion of the battery inside the cover member, a radiator that generates cooling water for cooling the motor and is provided along the vertical and front-rear directions; a cooling fan provided adjacent to the radiator and rotatable about an axis extending in the left-right direction; and an oil cooler provided along the vertical and longitudinal directions, the radiator is provided on a side of the cover member that is closer to a lateral portion thereof, The oil cooler is provided on the opposite side of the radiator from the lateral portion of the cover member.

2. The radiator, the cooling fan, and the oil cooler are provided so that the cooling fan is disposed between the radiator and the oil cooler; 2. The electric work vehicle according to claim 1, wherein the radiator is provided on a side of the cooling fan closer to the lateral portion of the cover member, and the oil cooler is provided on an opposite side of the cooling fan from the radiator.

3. 3. The electric work vehicle according to claim 1, wherein the radiator generates cooling water for cooling the motor and cooling water for cooling the inverter.

4. The electric work vehicle according to any one of claims 1 to 3, wherein a lateral ventilation section that allows ventilation is provided in a portion of the lateral section of the cover member that faces the radiator.

Images