Electric working 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 a cooling fan are provided. A shielding member 41 capable of shielding a flow of air to the battery 4 from the radiator 1 is provided between the radiator 1 inside the cover member 12, and the cooling fan and the front part of the battery 4.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] In an electric work vehicle, as disclosed in Patent Document 1, there is a configuration in which a battery provided at the front part of the vehicle body and an inverter to which the power of the battery is supplied are provided, and the motor is driven by the power from the inverter. In Patent Document 1, the battery is housed in a cover member, and a radiator that generates cooling water for cooling the motor and a cooling fan are provided in a region in front of the battery inside the cover member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the electric work vehicle of Patent Document 1, as the vehicle body moves forward, external air is mainly introduced from the front part of the cover member into the inside of the cover member, passes through the radiator by the action of the cooling fan, and the hot air flows from the cooling fan to the rear battery. In the battery, since an upper limit temperature at which power can be normally supplied is often set, for example, in the case of work in summer, if the hot air from the radiator flows toward the battery, the temperature of the battery may reach the upper limit temperature.

[0005] An object of the present invention is to reduce a situation disadvantageous to the normal power supply of the battery when a radiator and a cooling fan are provided in front of the battery in an electric work vehicle.

Means for Solving the Problems

[0006] The electric work vehicle of the present invention includes a battery provided at the front part of the vehicle body, an inverter to which the power of the battery is supplied, a motor driven by the power from the inverter, a traveling device driven by the motor, a cover member that houses the battery and is provided with an introduction part at the front part through which external air is introduced, a radiator provided between the introduction part and the front part of the battery inside the cover member and generating cooling water for cooling the motor, and a cooling fan provided between the introduction part and the front part of the battery inside the cover member and allowing the air introduced from the introduction part into the inside of the cover member to be supplied to the radiator. A shielding member capable of shielding the flow of air from the radiator to the battery is provided between the radiator and the cooling fan and the front part of the battery inside the cover member. Moreover, a horizontal ventilation portion that allows ventilation is provided at a portion of the horizontal portion of the cover member that faces the shielding member.

[0007] According to the present invention, when external air is introduced from the introduction part of the cover member into the inside of the cover member as the vehicle body moves forward, the air introduced into the inside of the cover member passes through the radiator by the action of the cooling fan and flows rearward from the radiator. In this case, the air from the radiator is blocked by the shielding member, and it is difficult for the air to flow to the battery behind the radiator. Thereby, it is possible to reduce the flow of high-temperature air from the radiator toward the battery, reduce the situations unfavorable for the normal power supply of the battery, and improve the durability of the battery. When the air introduced into the cover member passes through the radiator by the action of the cooling fan and is blocked by the shielding member, the air may flow in the left-right direction along the shielding member. According to the present invention, since a horizontal ventilation portion that allows ventilation is provided at a portion of the horizontal portion of the cover member that faces the shielding member, the air that passes through the radiator and flows in the left-right direction along the shielding member easily exits to the outside through the horizontal ventilation portion of the cover member. Thereby, it is possible to reduce the flow of high-temperature air from the radiator toward the battery, which is advantageous in terms of improving the durability of the battery.

[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 may be configured to have a sufficient capacity so that the motor and the inverter are cooled by the cooling water of the radiator. According to the present invention, even if the radiator is configured to have a sufficient capacity, it is possible to reduce the flow of hot air from the radiator toward the battery, which is advantageous in terms of improving the durability of the battery.

[0010]

[0011]

[0012] In the present invention, it is preferable that the shielding member is operable between a closed state in which the flow of air from the radiator to the battery can be shielded and an open state in which the flow of air from the radiator to the battery can be allowed.

[0013] In the battery, for example, in the case of work in summer, the temperature of the battery may reach the upper limit temperature, whereas in the case of work in winter, if the temperature of the battery decreases, the power supply of the battery may not be sufficiently performed, and when the temperature of the battery becomes low, the charging efficiency of the battery may decrease.

[0014] According to the present invention, the shielding member is configured to be operable between a closed state and an open state. For example, in the case of work in winter, when the work is interrupted and the electric work vehicle is left unattended for several hours, the shielding member may be operated to the open state and the cooling fan may be operated. Thereby, the hot air from the radiator flows through the shielding member toward the battery, and the temperature drop of the battery can be suppressed, so that the power supply of the battery can be performed without trouble when the work is restarted.

[0015] For example, when charging the battery in winter, before charging, the shielding member can be operated to the open state, the motor can be idled by the remaining power in the battery, and the cooling fan can be activated. As a result, the high-temperature air from the radiator flows through the shielding member towards the battery, and the temperature of the battery can be raised. Therefore, when charging the battery later, the charging of the battery can be carried out without any problems.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0017] The embodiments for carrying out 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 is defined as "front", the direction of arrow B is defined as "rear", the direction of arrow L is defined as "left", and the direction of arrow R is defined as "right". Also, the direction of arrow U in the drawings is defined as "up", and the direction of arrow D is defined as "down".

[0018] 〔Overall Configuration of the Tractor〕 Hereinafter, the tractor of the present embodiment will be described. As shown in FIG. 1, the tractor includes left and right front wheels 10, left and right rear wheels 11, and a cover member 12.

[0019] The tractor also includes a body frame 2 and an operation unit 3. The body frame 2 is supported by the left and right front wheels 10 and the left and right rear wheels 11.

[0020] The cover member 12 is disposed at the front of the body. And the operation unit 3 is provided behind the cover member 12. In other words, the cover member 12 is disposed in front of the operation unit 3.

[0021] The operation unit 3 has a protection frame 30, an operator seat 31, and a steering wheel 32. The operator can sit on the operator seat 31. Thereby, the operator can board the operation unit 3. By operating the steering wheel 32, the left and right front wheels 10 are steered. The operator can perform various driving operations in the operation unit 3.

[0022] The tractor includes a traveling battery 4. Also, the cover member 12 is configured to be swingable around an opening / closing axis Q along the left-right direction of the body. Thereby, the cover member 12 is configured to be openable and closable. When the cover member 12 is in the closed state, the traveling battery 4 is covered by the cover member 12.

[0023] As shown in FIG. 2, the tractor includes an inverter 14 and a motor M. The traveling battery 4 supplies electric power to the inverter 14. The inverter 14 converts the DC power from the traveling battery 4 into AC power and supplies it to the motor M. And the motor M is driven by the AC power supplied from the inverter 14.

[0024] As shown in FIGS. 2 and 3, the tractor includes 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.

[0025] The hydraulic pump 15a is driven by the rotational power from the motor M. When the hydraulic pump 15a is driven, rotational power is output from the hydraulic motor 15b. Note that the hydrostatic continuously variable transmission 15 is configured such that the rotational power is transmitted between the hydraulic pump 15a and the hydraulic motor 15b. Further, the hydrostatic continuously variable transmission 15 is configured such that the transmission ratio can be changed steplessly.

[0026] The rotational power output from the hydraulic motor 15b is transmitted to the transmission 16. The rotational power transmitted to the transmission 16 is shifted by the gear-type transmission mechanism of the transmission 16 and distributed to the left and right front wheels 10 and the left and right rear wheels 11. Thereby, the left and right front wheels 10 and the left and right rear wheels 11 are driven.

[0027] Also, as shown in FIGS. 2 and 3, the tractor includes 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. Thereby, the mid PTO shaft 17 and the rear PTO shaft 18 rotate.

[0028] If a working device is connected to the mid PTO shaft 17 or the rear PTO shaft 18, the working device is driven by the rotational power of the mid PTO shaft 17 or the rear PTO shaft 18. For example, as shown in FIG. 2, in the present embodiment, a mowing device 19 is connected to the mid PTO shaft 17. The mowing device 19 is driven by the rotational power of the mid PTO shaft 17.

[0029] 〔Configuration of Cover Member〕 As shown in FIGS. 1 and 2, the right and left body frames 2 and the transmission 16 are connected to form a body of the tractor as a skeleton by the body frames 2 and the transmission 16. The traveling battery 4 (hereinafter referred to as the battery 4) is mounted on the front part of the body, and the battery 4 is housed in the cover member 12 in a closed state.

[0030] As shown in FIG. 4, the cover member 12 is configured with a front portion 12a, right and left side portions 12b, and an upper portion 12c. A headlight 20 and a ventilable lattice-shaped front grille 21 (corresponding to the introduction portion) are provided on the front portion 12a of the cover member 12, and ventilable lattice-shaped side grilles 22 (corresponding to the lateral ventilation portion), 23 are provided on the right and left side portions 12b of the cover member 12. As the aircraft moves forward, external air is introduced mainly through the front grille 21 into the interior of the cover member 12.

[0031] 〔Configuration Regarding Battery〕 As shown in FIGS. 7, 8, and 9, a plurality of stacks (not shown) in which a plurality of battery modules (not shown) are connected are accommodated inside the battery 4, and connection portions 4a, 4b, 4c, 4d are provided at the front portion of the battery 4.

[0032] A connection portion 13 to which a charger (not shown) of an external power source (not shown) is connected is provided at the left portion of the front portion of the battery 4, and a harness 24 is connected across the connection portion 4a of the battery 4 and the connection portion 13. Electric power of the external power source is supplied to the connection portion 4a of the battery 4 via the connection portion 13 and the harness 24, and the battery 4 is charged. A harness 25 is connected across the connection portion 4b of the battery 4 and the inverter 14, and electric power is supplied from the connection portion 4b of the battery 4 to the inverter 14.

[0033] As shown in FIGS. 7 and 8, a DC-DC converter 5 and a battery 6 are provided between the front grille 21 and the front portion of the battery 4 inside the cover member 12 along the vertical direction and the front-rear direction.

[0034] A harness 26 (see FIG. 9) is connected across the connection portion 4c of the battery 4 and the DC-DC converter 5, electric power of the battery 4 is supplied to the DC-DC converter 5, and electric power stepped down to 12V by the DC-DC converter 5 is supplied to the battery 6.

[0035] A harness 27 (see FIG. 9) is connected across the connection part 4d of the battery 4 and the battery 6, and 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] 〔Radiator and Configuration near the Radiator〕 As shown in FIGS. 7 and 8, between the front grille 21 and the front part of the battery 4 inside the cover member 12, on the left side of the DC-DC converter 5 and the battery 6, the radiator 1 is provided along the vertical and horizontal directions.

[0037] As shown in FIGS. 5 to 8, between the front grille 21 and the front part of the battery 4 inside the cover member 12, behind the radiator 1, the fan device 7 is provided along the vertical and horizontal directions. A stay 28 is connected across the left part of the upper part of the radiator 1 and the front part of the battery 4, and the aforementioned connection part 13 is supported by the stay 28.

[0038] The fan device 7 is provided with a cooling fan 7a rotatable around the axis along the front-rear direction, an electric motor (not shown) for rotationally driving the cooling fan 7a, and a fan shroud 7b covering the cooling fan 7a and the electric motor. The electric motor is driven by the 12V power of 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.

[0039] As shown in FIGS. 5, 6, and 7, between the front grille 21 and the front part of the battery 4 inside the cover member 12, in the part between the fan device 7 and the front part of the battery 4, the oil cooler 8 is provided along the vertical and horizontal directions.

[0040] In a plan view, a channel-shaped support member 38 is connected along the left-right direction across the right and left portions at the rear of the radiator 1, and the upper portion of the oil cooler 8 is connected to the support member 38. The oil cooler 8 is for cooling the hydraulic oil of the hydrostatic continuously variable transmission 15 and the hydraulic oil of other hydraulic devices (not shown).

[0041] 〔Configuration of Cooling by Radiator〕 As shown in FIGS. 5 to 8, a water pump 9 is provided between the right and left body frames 2, and the water pump 9 is driven by the 12V power of the battery 4. A pipe 29 is connected across the lower portion of the radiator 1 and the water pump 9, and a pipe 33 is connected across the water pump 9 and the inverter 14.

[0042] A pipe 34 is connected across the inverter 14 and the motor M, and a pipe 35 is connected across the motor M and the DC-DC converter 5. A pipe 36 is connected across the DC-DC converter 5 and the upper portion of the radiator 1, and a water supply port 37 is provided in the pipe 36.

[0043] 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.

[0044] 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 motor M, the inverter 14, and the DC-DC converter 5 are cooled by the cooling water generated in the radiator 1. Thereby, the radiator 1 generates the cooling water for cooling the motor M, the cooling water for cooling the inverter 14, and the cooling water for cooling the DC-DC converter 5.

[0045] 〔Configuration Regarding Shielding Member〕 As shown in FIGS. 5, 6, 7, and 9, a shielding device 39 is provided along the vertical and horizontal directions between the front grille 21 and the front portion of the battery 4 inside the cover member 12, and also between the oil cooler 8 and the front portion of the battery 4.

[0046] The shielding device 39 is provided with a frame member 40, a shielding member 41, an operation lever 42, etc. The shielding device 39 has substantially the same height as the radiator 1, and is higher than the fan device 7 and the oil cooler 8. The shielding device 39 has substantially the same width as the radiator 1, the fan device 7, and the oil cooler 8.

[0047] In the shielding device 39, the frame member 40 is formed in a rectangular shape when viewed from the front, and the lower part of the frame member 40 is connected to the body frame 2. A support stay 43 is connected to the support member 38 and extends obliquely rearward and upward from the support member 38, and the upper part of the frame member 40 is connected to the support stay 43.

[0048] In the shielding device 39, the shielding member 41 is formed in a horizontally long and slender flat plate shape when viewed from the front. A number of shielding members 41 are arranged side by side along the vertical direction, and the upper part of each shielding member 41 is swingably attached to the frame member 40 around an axis along the horizontal direction. Each of the shielding members 41 is swingable between a downward-facing closed state and a rearward-facing open state.

[0049] In the shielding device 39, the operation lever 42 is provided at the upper part of the frame member 40. When the operation lever 42 is operated, all the shielding members 41 are operated to the closed state (see FIG. 5), and all the shielding members 41 are operated to the open state (see FIG. 6).

[0050] With the above configuration, the shielding device 39 (shielding member 41) is provided between the radiator 1 and the fan device 7 (cooling fan 7a) and the front portion of the battery 4 inside the cover member 12. Right and left side grilles 22 are provided at portions of the right and left horizontal portions 12b of the cover member 12 that face the shielding device 39 (shielding member 41).

[0051] 〔Operating state of the fan device〕 As shown in FIGS. 5 to 8, as the aircraft moves forward, external air is mainly introduced into the inside of the cover member 12 through the front grille 21. When the cooling fan 7a of the fan device 7 is rotationally driven, the air introduced into the inside of the cover member 12 passes through the radiator 1, and the air that has passed through the radiator 1 passes through the oil cooler 8 from the fan device 7 (cooling fan 7a) and flows backward.

[0052] As shown in FIGS. 5 and 9, in the shielding device 39, when the operator operates the operation lever 42 and all the shielding members 41 are operated to the closed state, in each of the shielding members 41, the lower part of the upper shielding member 41 is in contact with the upper part of the lower shielding member 41.

[0053] As a result, the air that has passed through the oil cooler 8 from the fan device 7 (cooling fan 7a) and flows backward cannot pass through the shielding device 39 (shielding member 41), and the air flow from the radiator 1 to the battery 4 is blocked. The air blocked by the shielding device 39 (shielding member 41) flows in the left - right direction along the shielding device 39 (shielding member 41), and mainly exits to the outside of the cover member 12 through the right and left side grilles 22.

[0054] As shown in FIG. 6, in the shielding device 39, when the operator operates the operation lever 42 and all the shielding members 41 are operated to the open state, in each of the shielding members 41, the lower part of the upper shielding member 41 is separated from the upper part of the lower shielding member 41 rearward and upward.

[0055] As a result, the air that has passed through the oil cooler 8 from the fan device 7 (cooling fan 7a) and flows backward passes through the shielding device 39 (shielding member 41) and flows to the battery 4, and the air flow from the radiator 1 to the battery 4 is allowed.

[0056] 〔First alternative embodiment of the invention〕 In the shielding device 39, the operation lever 42 may be abolished, and instead of a number of horizontally long and slender flat shielding members 41, one flat shielding member 41 having the same size as the frame member 40 may be adopted. According to this configuration, when the shielding member 41 is attached to the frame member 40, the shielding member 41 is in the closed state, and when the shielding member 41 is removed from the frame member 40, the shielding member 41 is in the open state.

[0057] 〔Second alternative embodiment of the invention〕 The shielding device 39 (shielding member 41) may be configured to be higher than the radiator 1, or may be configured to have a height close to the upper part 12c of the cover member 12. The shielding device 39 (shielding member 41) may be configured to have a width larger than that of the radiator 1, or may be configured to have a width extending across the right and left horizontal parts 12b of the cover member 12.

[0058] 〔Third alternative embodiment of the invention〕 In the shielding device 39, the operation lever 42 may be abolished and may be configured as described below.

[0059] In the shielding device 39, an electric motor (not shown) for operating the shielding member 41 between the closed state and the open state is provided. A battery temperature sensor (not shown) for detecting the temperature of the battery 4 and an air temperature sensor (not shown) for detecting the outside air temperature are provided, and based on the detection values of the battery temperature sensor and the air temperature sensor, the shielding member 41 is automatically operated between the closed state and the open state by the electric motor.

[0060] 〔Fourth alternative embodiment of the invention〕 The fan device 7 (cooling fan 7a) may be provided in front of the radiator 1. The front wheels 10 and the rear wheels 11 are the traveling devices of the present invention. Instead of the front wheels 10 and the rear wheels 11, right and left crawler traveling devices (not shown) may be provided on the machine body as the traveling devices.

Industrial applicability

[0061] The present invention can be applied not only to tractors but also to other electric work vehicles such as electric carts and carrier vehicles, and can also be applied to self-driving or wirelessly controlled electric work vehicles without an operator on board.

Explanation of Signs

[0062] 1 Radiator 4 Battery 7a Cooling fan 10 Front wheels (travel device) 11 Rear wheels (travel device) 12 Cover member 12a Front part 12b Side part 14 Inverter 21 Front grille (introduction part) 22 Side grille (lateral ventilation part) 41 Shielding member M Motor

Claims

1. A battery provided at the front of the vehicle body, an inverter supplied with power from the battery, a motor driven by the power from the inverter, a traveling device driven by the motor, a cover member that houses the battery and is provided with an introduction part at the front for introducing external air, a radiator provided between the introduction part and the front part of the battery inside the cover member, which generates cooling water for cooling the motor, a cooling fan provided between the introduction part and the front part of the battery inside the cover member, which supplies the air introduced from the introduction part into the inside of the cover member to the radiator, a shielding member capable of shielding the flow of air from the radiator to the battery is provided between the radiator and the cooling fan and the front part of the battery inside the cover member, An electric work vehicle provided with a horizontal ventilation part capable of ventilation at a portion of the lateral part of the cover member facing the shielding member.

2. 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.

3. The electric work vehicle according to claim 1 or 2, wherein the shielding member is operable between a closed state capable of shielding the flow of air from the radiator to the battery and an open state capable of allowing the flow of air from the radiator to the battery.

Images