Work vehicle

Abstract

To provide a working vehicle improved in stability during traveling by optimizing weight balance between a front vehicle body and a rear vehicle body.SOLUTION: The wheel loader 1 includes a vehicle body 4 in which a front vehicle body 2 and a rear vehicle body 3 are connected to each other in a laterally swingable manner, front wheels 21, 21 and rear wheels 31, 31 for making the vehicle body 4 travel, a loader 5 supported by the front vehicle body 2, a first battery 61 disposed in the front vehicle body 2, a first drive system for driving a bucket cylinder 55 and lift cylinders 54, 54 of the loader 5 by electric power supplied from the first battery 61, and a second drive system for driving the front wheels 2, 21 and the rear wheels 3, 3 by electric power supplied from the second battery 71.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a work vehicle equipped with a work implement. [Background technology]

[0002] Conventionally, a work vehicle such as a wheel loader is composed of a vehicle body equipped with a plurality of wheels and a work implement disposed in front of the vehicle body. The vehicle body of a wheel loader is composed of a front body and a rear body connected to each other so that they can swing freely left and right.

[0003] Patent Document 1 proposes a wheel loader in which a drive battery, which is the power source for the electric motor used to drive the wheels and the working equipment, is mounted on the rear body of the vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-201187 Summary of the Invention [Problem to be solved by the invention]

[0005] In the wheel loader disclosed in Patent Document 1, all batteries are mounted on the rear body, so the load on the rear wheels supporting the rear body is greater than the load on the front wheels supporting the front body. As a result, when going uphill, the weight distribution of the front wheel load is further reduced, and running stability is reduced.

[0006] Furthermore, the wheel loader's working implement is attached to the front vehicle body and has a pair of left and right lift arms and a bucket attached to the ends of the pair of left and right lift arms. With such a wheel loader, increasing the bucket capacity is one way to balance the weight between the front vehicle body and the rear vehicle body carrying the battery. However, increasing the bucket capacity requires increasing the strength of the lift arms and the frame of the front vehicle body that supports the lift arms. This makes the weight of the front vehicle body heavier than the rear vehicle body. In other words, simply increasing the bucket capacity makes it difficult to resolve the poor weight balance between the front vehicle body and the rear vehicle body.

[0007] Furthermore, as in the wheel loader disclosed in Patent Document 1, in order to supply the power required to operate the work equipment attached to the front body from a battery located in the rear body to the front body, it is necessary to route a power supply line from the rear body to the front body. However, in a wheel loader, the power supply line is bent when the front body and the rear body swing left and right. This makes it necessary to take further measures to improve the durability of the power supply line. This poses a problem of increased complexity in the assembly work of the work vehicle.

[0008] Furthermore, in a wheel loader in which a work machine having a hydraulic actuator is attached to the front body, if the battery is located in the front body and the hydraulic oil tank and hydraulic pump are located in the rear body to balance the weight with the battery on the front body, it will be necessary to run a hose for supplying hydraulic fluid to the hydraulic actuator from the rear body to the front body. In this case, as with the power supply line, measures will need to be taken to consider the durability of the hose against bending that occurs when the front and rear bodies swing left and right, and the assembly work of the work vehicle will become more complicated.

[0009] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a work vehicle that optimizes the weight balance between the front and rear bodies and improves stability during driving. [Means for solving the problem]

[0010] The work vehicle of the present invention is a work vehicle comprising a vehicle body in which a front body and a rear body are connected so as to be able to swing freely left and right, drive wheels that drive the vehicle body, and a work implement supported on the front body, and is also provided with a first battery arranged in the front body, a first drive system that drives an actuator of the work implement using power supplied from the first battery, a second battery arranged in the rear body, and a second drive system that drives the drive wheels using power supplied from the second battery.

[0011] A work vehicle according to another aspect of the present invention is a work vehicle in which the first drive system includes a first electric motor arranged in the front body, and the second drive system includes a second electric motor arranged in the rear body.

[0012] A work vehicle according to another aspect of the present invention is a work vehicle in which the first battery is arranged on one side of the front body in the fore-and-aft direction relative to the first electric motor, and the second battery is arranged on one side of the rear body in the fore-and-aft direction relative to the second electric motor.

[0013] A work vehicle according to another aspect of the present invention is a work vehicle in which the actuator is a hydraulic actuator, the first drive system includes a hydraulic oil tank disposed in the front body for storing hydraulic oil to be supplied to the hydraulic actuator, and the first battery is disposed on one side of the front body in the fore-and-aft direction relative to the hydraulic oil tank.

[0014] In another aspect of the present invention, the work vehicle is such that the hydraulic actuators include a first hydraulic actuator and a second hydraulic actuator, the first drive system is provided with a control valve disposed in the front body and controlling the supply and discharge of hydraulic oil to the first hydraulic actuator and the second hydraulic actuator, and the control valve is disposed on one side of the front body in the vertical direction relative to the first electric motor.

[0015] A work vehicle according to another aspect of the present invention is the work vehicle described above, wherein at least one of the control valve and the first electric motor is disposed above the hydraulic oil tank.

[0016] A work vehicle according to another aspect of the present invention is a work vehicle in which the first battery is arranged in front of the control valve, and the control valve is arranged between the hydraulic oil tank and the first electric motor in the vertical direction.

[0017] In another aspect of the work vehicle of the present invention, the control valve is disposed above the hydraulic oil tank, and a hydraulic pump that pressurizes the hydraulic oil stored in the hydraulic oil tank to the first hydraulic actuator and the second hydraulic actuator is disposed offset in the width direction of the front vehicle body from the control valve.

[0018] A work vehicle according to another aspect of the present invention is one in which the second drive system includes a power distribution device that distributes the power transmitted from the second electric motor in different directions, and the second electric motor is arranged above the power distribution device.

[0019] Another aspect of the work vehicle of the present invention is a work vehicle in which the drive wheels are a pair of front wheels mounted on the front body and a pair of rear wheels mounted on the rear body, the power distribution device distributes power transmitted from the second electric motor to the pair of front wheels and the pair of rear wheels, and the second electric motor is positioned in a position offset in the width direction of the rear body from a power transmission shaft that extends in the fore-and-aft direction of the vehicle body and transmits the power distributed by the power distribution device to the pair of front wheels. [Effects of the Invention]

[0020] According to the present invention, in a configuration in which the vehicle body has a front body and a rear body connected so that they can swing freely left and right, by placing a first battery in the front body and a second battery in the rear body, the weight balance between the front body and the rear body is optimized, making it possible to improve stability during driving. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a perspective view of a wheel loader according to an embodiment of the present invention. [Figure 2] 1 is a left side view showing the interior of a wheel loader according to an embodiment of the present invention. FIG. [Figure 3] 1 is a plan view showing the interior of a wheel loader according to an embodiment of the present invention. FIG. [Figure 4] FIG. 2 is a block diagram illustrating a first drive system of the wheel loader according to one embodiment of the present invention. [Figure 5] FIG. 4 is a block diagram illustrating a second drive system of the wheel loader according to one embodiment of the present invention.

[0022] The present invention aims to improve the stability of a work vehicle while it is traveling by devising the layout of the batteries and the layout of the various devices and accessories that are powered by the electric power from the batteries in a configuration in which a plurality of batteries are mounted on the vehicle to use electricity as a power source for the work equipment and wheels. Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] In the embodiments of the present invention, a wheel loader, which is an articulated work vehicle, will be described as an example of a work vehicle according to the present invention. However, the work vehicle according to the present invention is not limited to wheel loaders used for excavating and loading earth and sand, and can be widely applied to other work vehicles, such as agricultural tractors.

[0024] The configuration of the wheel loader 1 according to this embodiment will be described with reference to the drawings. In the following, unless a particular viewing direction is specified, the terms "front side," "rear side," "left and right sides," "flat side" or "upper side," "bottom side" or "lower side" will be used based on the position of the operator seated in the driver's seat of the wheel loader 1.

[0025] The overall configuration of a wheel loader 1 according to this embodiment will be described. Fig. 1 is a perspective view of the wheel loader 1. Fig. 2 is a left side view showing the interior of the wheel loader 1. Fig. 3 is a plan view showing the interior of the wheel loader 1. Note that in Figs. 2 and 3, the illustration of the configuration that is on the front side when viewed from each direction has been omitted as appropriate to allow for understanding of the main internal configuration.

[0026] The wheel loader 1 comprises a vehicle body 4 consisting of a front body 2 and a rear body 3, and a loader 5 attached to the front body 2 as a working machine.

[0027] The front vehicle body 2 has a front frame 20 supported by a pair of left and right front wheels 21, 21. The rear vehicle body 3 has a rear frame 30 supported by a pair of left and right rear wheels 31, 31. The rear end of the front frame 20 and the front end of the rear frame 30 are connected via a pivot shaft 41 whose axial direction is in the vertical direction. A steering cylinder 42 (see FIG. 3) is provided between the front vehicle body 2 and the rear vehicle body 3. As shown in FIG. 3, one end of the steering cylinder 42 is supported by a support bracket 43a that protrudes to the right from a connecting bracket 43 provided in the center of the front end of the rear frame 30, and the other end is supported by a bracket (not shown) fixed to the front frame 20 of the front vehicle body 2. The front vehicle body 2 and the rear vehicle body 3 bend left and right relative to each other about the pivot shaft 41 by extending and retracting the steering cylinder 42.

[0028] A loader 5 is mounted on the front vehicle body 2. The loader 5 is composed of a pair of left and right lift arms 51, 51, and a bucket 52 attached in a horizontal manner to the front ends of the pair of left and right lift arms 51, 51.

[0029] The pair of left and right lift arms 51, 51 have their base ends supported by the upper ends of a pair of left and right support columns 23, 23 erected on the rear side of the front frame 20, via pivotal support shafts 26 whose axial direction is in the left-right direction. A support section 24 is installed between each of the support columns 23, 23. A cylinder bracket 24a protrudes from the center of the support section 24 and supports a bucket cylinder 53 that swings the bucket 52 up and down. Lift cylinders 54, 54 that raise and lower both lift arms 51, 51 are installed between the midpoints of each of the lift arms 51, 51 and the midpoints of the support columns 23, 23, respectively. As the lift cylinders 54 extend and retract, the left and right lift arms 51, 51 rotate up and down around the pivotal support shafts 26 as fulcrums.

[0030] The pair of left and right lift arms 51, 51 are connected to each other at their midpoints by a connecting portion 56. A bell crank support piece 56a that rotatably supports a bell crank 55 is provided in the center of the connecting portion 56 in the left-right direction.

[0031] Bell crank 55 has a boomerang shape that extends in the vertical direction. The middle portion of bell crank 55 is attached to bell crank support piece 56a via support shaft 58 whose axial direction is in the left-right direction. The tip of rod portion 53b of bucket cylinder 53 is rotatably connected to the upper end of bell crank 55. An interlocking link 57 that interlocks bucket 52 and bell crank 55 is interposed between the lower end of bell crank 55 and bucket 52.

[0032] A base end of a cylinder portion 53a of the bucket cylinder 53 is rotatably supported by a cylinder bracket 24a. When the bucket cylinder 53 extends and contracts, the bucket 52 rotates about its axis in the left-right direction via a bell crank 55 and an interlocking link 57.

[0033] The lift cylinder 54 and bucket cylinder 53 of the loader 5 are both double-acting hydraulic cylinders that are operated by pressure oil discharged from the hydraulic pump 45. Each hydraulic cylinder is connected to hydraulic pipes (not shown) for supplying and discharging hydraulic pressure.

[0034] In the front frame 20, the space defined by the pair of lift arms 51, 51 in the left-right direction and the connecting portion 56 and the support portion 24 in the front-rear direction is a space for accommodating the first battery 61 (described later) and hydraulic equipment that supplies hydraulic oil to the hydraulic cylinder, and the upper part of this space is covered by a mudguard cover 25 (see Figure 1).

[0035] The rear vehicle body 3 is provided with a driver's section 10 that drives and operates the vehicle body 4 and the loader 5. The driver's section 10 has a horizontal floor section 11 provided in the front half of the rear frame 30 of the rear vehicle body 3, and a driver's seat 12 installed on a platform-shaped hood 15 provided in the rear half of the rear frame 30.

[0036] A cylindrical steering column 13 with a steering shaft installed therein is provided extending in the vertical direction in the front part of the floor part 11. The steering column 13 is provided in an inclined position with the front low and the rear high in a side view, and a handle 14 is attached to the upper end of the steering column 13 so that the operator can steer the front wheels 21 and rear wheels 31, which are the drive wheels.

[0037] The hood 15 is provided on a plate portion 32 that is disposed substantially horizontally at substantially the same height as the floor portion 11. The inside of the hood 15 is supported by a support frame 33 whose ends are fixed to the plate portion 32. A first battery 61 (described later) and other components are disposed in the internal space of the hood 15. A first electric motor 63 (described later) is disposed below the floor portion 11.

[0038] The upper part of the driver's section 10 is covered by a canopy 16. The canopy 16 is composed of a pair of left and right support columns 16a, 16a that extend upward from the plate section 32 at the rear end of the rear frame 30, and a canopy roof 16b that extends forward between the pair of left and right support columns 16a, 16a.

[0039] In the wheel loader 1 having the above-described configuration, the desired operation and work are performed by the operator in the driver's section 10 appropriately operating the steering wheel 14 and / or the work operation lever (not shown). For example, left and right turning is performed by operating the steering wheel 14, and excavation work, etc. is performed by the loader 5 by operating the work operation lever.

[0040] The drive system of the loader 5 in the wheel loader 1 according to this embodiment and the drive systems related to the travel of the vehicle main body 4 will now be described in further detail. Fig. 4 is a block diagram illustrating the first drive system 60, and Fig. 5 is a block diagram illustrating the second drive system 70. Note that in Fig. 4, with regard to the connection lines of each component, the power supply system from the first battery 61 is shown with a thick line, the signal system with a dashed line, and the hydraulic system operated by drive of the first electric motor 63 with a thin line. Also, in Fig. 5, with regard to the connection lines of each component, the power supply system from the second battery 71 is shown with a thick line, the signal system with a dashed line, and the power transmission system operated by drive of the second electric motor 73 with a double line.

[0041] The first drive system 60 is a system that drives actuators and the like that operate the loader 5 using power supplied from a first battery 61 arranged in the front vehicle body 2. The actuators in the first drive system 60 are hydraulic actuators. Specifically, the hydraulic actuators are the lift cylinders 54, 54, which are the first actuators, and the bucket cylinder 53, which is the second actuator.

[0042] The first drive system 60 is configured to include a first battery 61, a junction box 62 that is connected to the first battery 61 and branches the power supplied by the first battery 61 to each electrical device, and a first electric motor 63 that operates with the power supplied via the junction box 62. The first drive system 60 is configured so that the hydraulic pump 45 is operated by the rotation of the first electric motor 63, and hydraulic oil stored in a hydraulic oil tank 46 is supplied to each actuator via a control valve 47. The hydraulic equipment including the first battery 61, first electric motor 63, and hydraulic oil tank 46 that make up the first drive system 60 are arranged in the front body 2.

[0043] The first battery 61 is disposed on the front side of the front vehicle body 2. The first battery 61 is a battery unit made up of a plurality of power storage modules, and is connected to a charger 64 via a junction box 62. The first battery 61 can be charged by connecting the charger 64 to an external power source such as a commercial power source via a cable.

[0044] The first battery 61 is connected to the first electric motor 63 via a junction box 62. An inverter 65 for the first electric motor 63 is interposed between the first electric motor 63 and the junction box 62. The inverter 65 converts DC power supplied from the first battery 61 into AC power and transmits the AC power to the first electric motor 63 based on a command signal input from a front controller 66.

[0045] The front controller 66 is an electronic control unit that controls various devices mounted on the front body 2, including the loader 5. The front controller 66 receives input from an operating device disposed in the driver's section 10 and outputs a command signal according to the input.

[0046] The first battery 61 is connected to a cooling water pump 68 via a junction box 62. The cooling water pump 68 operates a cooling mechanism that cools electrical equipment such as an inverter 65 mounted on the front vehicle body 2. The cooling mechanism includes, for example, a radiator (not shown) that cools the cooling water, a cooling water pump 68 that sends out the cooling water, and a cooling path (not shown) that circulates the cooling water. The cooling mechanism cools the electrical equipment by driving the cooling water pump 68 with power supplied from the first battery 61 and circulating the cooling water through the cooling path.

[0047] A hydraulic oil tank 46 for storing hydraulic oil and a control valve 47 are arranged in the front body 2. The control valve 47 is a control valve device that supplies hydraulic oil to the corresponding hydraulic actuators in accordance with the operating state of an operating device, such as a work operation lever, arranged in the driver's unit 10. The control valve 47 is composed of a plurality of directional control valves that correspond to each of the hydraulic actuators, such as the lift cylinders 54, 54 and the bucket cylinder 53, and selectively controls the supply and discharge of hydraulic oil to each hydraulic actuator. The hydraulic oil discharged from the hydraulic pump 45 by driving the first electric motor 63 is supplied to the control valve 47 and operates each hydraulic actuator.

[0048] The second drive system 70 is a system that drives the drive wheels that propel the vehicle body 4 using electric power supplied from a second battery 71 disposed in the rear vehicle body 3. The second drive system 70 includes the second battery 71, a junction box 72 that is connected to the second battery 71 and branches the electric power supplied by the second battery 71 to various electrical devices, and a second electric motor 73 that operates using the electric power supplied via the junction box 72. The second battery 71, second electric motor 73, and a gearbox 81 (described later) that constitute the second drive system 70 are disposed in the rear vehicle body 3. The second drive system 70 is configured to operate a rear axle 82 using rotation of the second electric motor 73, and to transmit the rotational power to a front axle 84 on the front vehicle body 2 side via a propeller shaft 83, which is a power transmission shaft.

[0049] The second battery 71 is disposed in the hood 15 below the driver's seat 12. Like the first battery 61, the second battery 71 is configured to include a plurality of power storage modules. The second battery 71 is connected to a charger 74 via a junction box 72. By connecting the charger 74 to an external power source such as a commercial power source, the second battery 71 can be charged.

[0050] The second battery 71 is connected to the second electric motor 73 via a junction box 72. An inverter 75 for the second electric motor 73 is interposed between the second electric motor 73 and the junction box 72. Based on a command signal input from a rear controller 76, the inverter 75 converts DC power supplied from the second battery 71 into AC power and transmits the AC power to the second electric motor 73.

[0051] The rear controller 76 is an electronic control unit that controls various devices mounted on the rear vehicle body 3. The rear controller 76 receives input from an operating device disposed in the driving section 10 and outputs a command signal according to the input.

[0052] The second battery 71 is connected to a cooling water pump 78 via a junction box 72. The cooling water pump 78 operates a cooling mechanism that cools electrical equipment such as an inverter 75 mounted on the rear body 3. Note that the cooling mechanism used here is the same as the cooling mechanism that cools electrical equipment by operating the cooling water pump 68 in the first drive system 60.

[0053] The second battery 71 is connected to the steering cylinder 42 via a junction box 72. The steering cylinder 42 is an electric cylinder that is driven by power supplied from the second battery 71. A steering cylinder inverter 77 is installed between the second battery 71 and the steering cylinder 42. Based on a command signal input from the rear controller 76, the inverter 77 converts the DC power supplied from the second battery 71 into AC power and transmits the AC power to the steering cylinder 42.

[0054] A rear axle 82 and a gearbox 81 are provided below the rear frame 30. The rear axle 82 extends in the left-right direction, and rear wheels 31, 31 are attached to both left and right ends of the rear axle 82. A differential device 85 (shown by a dashed line in FIG. 3) is provided in the center of the rear axle 82 and is connected to a differential device (not shown) on the front axle 84 side via a propeller shaft 83. Rotational power of the second electric motor 73 is input to the rear axle 82 via the gearbox 81. The rear axle 82 transmits the rotational power of the second electric motor 73 to the rear wheels 31, 31.

[0055] The gearbox 81 constitutes a power distribution device that distributes the rotational power of the second electric motor 73 to the front wheels 21, 21 and the rear wheels 31, 31. In other words, the gearbox 81, together with the propeller shaft 83, constitutes a power transmission mechanism that transmits the rotational power of the second electric motor 73 to the rear axle 82 and the front axle 84.

[0056] The gearbox 81 is also connected to a front axle 84 via a propeller shaft 83. As shown in FIG. 2, the propeller shaft 83 is provided extending in the front-to-rear direction of the vehicle body 4. The propeller shaft 83 transmits the power distributed by the gearbox 81 to the pair of front wheels 21, 21. The propeller shaft 83 is provided below the rear frame 30 and the front frame 20, and is disposed in the center of the vehicle body 4 in the width direction in a plan view, as shown by a dashed line in FIG. 3, that is, along a center line CL shown by a dashed line in FIG. 3.

[0057] The front axle 84 is provided below the front frame 20. The front axle 84 is formed to extend in the left-right direction, and front wheels 21, 21 are attached to both ends of the front axle 84. The front axle 84 transmits the rotational power of the second electric motor 73, which is input via the gearbox 81 and the propeller shaft 83, to the front wheels 21, 21.

[0058] In the wheel loader 1 according to this embodiment, the power transmission mechanism that transmits the rotational power of the second electric motor 73 to the drive wheels includes a gearbox 81 and a propeller shaft 83, so that the rotational power of the second electric motor 73 is distributed and transmitted to the rear axle 82 and the front axle 84. As a result, the wheel loader 1 travels in a four-wheel drive state in which the left and right front wheels 21, 21 and the left and right rear wheels 31, 31 rotate simultaneously. However, by changing the configuration of the power transmission mechanism that transmits the rotational power of the second electric motor 73 to the drive wheels, only the rear wheels 31, 31 of the wheel loader may be used as drive wheels.

[0059] 2 and 3, the arrangement of the main components of the first drive system 60 and the second drive system 70 inside the front vehicle body 2 and the rear vehicle body 3 will be described.

[0060] The first battery 61 disposed in the front vehicle body 2 has a generally rectangular shape with its long sides extending in the vertical direction in the side view shown in Fig. 2, and has a generally rectangular shape with its long sides extending in the left-right direction, which is the width direction of the front vehicle body 2, in the plan view shown in Fig. 3. The lower end of the first battery 61 is fixed to the front frame 20. The first battery 61 is disposed so that the center of the first battery 61 aligns with a center line CL that passes through the center of the vehicle body 4 in the fore-and-aft direction in the plan view.

[0061] A first electric motor 63 and a hydraulic oil tank 46 are disposed behind the first battery 61. The first battery 61 is disposed forward of the first electric motor 63 in the fore-and-aft direction of the front body 2, and is also disposed forward of the hydraulic oil tank 46 in the fore-and-aft direction of the front body 2.

[0062] The hydraulic oil tank 46 has a substantially rectangular parallelepiped shape that is as long as the first battery 61 in the left-right direction, which is the width direction of the front vehicle body 2, and is shorter than the first battery 61 in the up-down direction.

[0063] A control valve 47 is disposed above the hydraulic oil tank 46. The control valve 47 is fixed to the upper surface of the hydraulic oil tank 46 with fasteners such as bolts. A first electric motor is disposed above the control valve 47. In other words, the control valve 47 is disposed below the first electric motor 63 in the up-down direction of the front body 2. In other words, the control valve 47 is disposed rearward of the first battery 61 in the fore-and-aft direction of the front body 2, and is disposed between the first electric motor 63 and the hydraulic oil tank 46 in the up-down direction.

[0064] The first electric motor 63 is disposed at a position offset in the width direction of the front vehicle body 2. Specifically, the first electric motor 63 is disposed at a position offset to the right with respect to the center line CL in the plan view shown in FIG. 3. The first electric motor 63 is disposed at a position offset to the right in the left-right direction, which is the width direction of the front vehicle body 2, and the control valve 47 is disposed directly below it. Furthermore, the hydraulic pump 45 is disposed above the hydraulic oil tank 46 at a position offset in the width direction of the front vehicle body 2 with respect to the control valve 47. In other words, the hydraulic pump 45 is disposed to the left of the control valve 47, which is disposed at a position offset to the right with respect to the center line CL. By disposing the hydraulic oil tank 46 and the hydraulic equipment together in the front vehicle body 2 in this way, it is possible to make maintenance of the hydraulic equipment more efficient.

[0065] In this embodiment, the vertical positional relationship between the first electric motor 63 and the hydraulic oil tank 46 is such that the hydraulic oil tank 46 is on the bottom and the first electric motor 63 is on the top, but they may be reversed. In this embodiment, the hydraulic oil tank 46, which has a larger volume, is on the bottom, and the control valve 47 and hydraulic pump 45 are disposed in the space between the hydraulic oil tank 46 and the first electric motor 63, so that the hydraulic equipment is concentrated on the rear side of the front frame 20.

[0066] Furthermore, for example, if the hydraulic oil tank 46, hydraulic pump 45, and control valve 47 were located in the rear vehicle body 3, hoses for supplying hydraulic fluid to the lift cylinders 54, 54 and bucket cylinder 53 located in the front vehicle body 2 would have to be laid across the rear vehicle body 3 and the front vehicle body 2. In this case, the efficiency of the assembly work would decrease due to the need to route the hoses. On the other hand, in the wheel loader 1 of this embodiment, all of the hydraulic equipment is located on the front vehicle body 2 side, which improves the efficiency of the assembly work.

[0067] The second battery 71 disposed in the rear vehicle body 3 is disposed within the hood 15 below the driver's seat 12 located at the rear of the rear vehicle body 3. The second battery 71 has the same size and shape as the first battery 61, and is disposed so that the center of the second battery 71 aligns with a center line CL that runs along the front-to-rear direction and passes through the center of the vehicle body 4 in a plan view. The second battery 71 is also provided so as to vertically penetrate approximately the center of the plate portion 32 within the hood 15, and is supported by a support member (not shown) connected to the plate portion 32 and / or a reinforcing member (not shown) of the rear frame 30 that supports the plate portion 32 from below.

[0068] The second electric motor 73 is disposed below the floor 11 and forward of the second battery 71. The second electric motor 73 is also disposed forward of the rear axle 82. In other words, the second electric motor 73 and the second battery 71 are disposed in front of and behind the rear axle 82.

[0069] The second electric motor 73 is disposed at a position offset in the width direction of the rear vehicle body 3. Specifically, the second electric motor 73 is disposed at a position offset to the right with respect to the center line CL in the plan view shown in Fig. 3. The second electric motor 73 is disposed at a position offset to the right in the left-right direction, which is the width direction of the rear vehicle body 3, and a gear box 81 is disposed further below the second electric motor 73.

[0070] The gearbox 81 has an input shaft to which power from the second electric motor 73 is input, and an output shaft that transmits the power to the rear axle 82 and the front axle 84. The output shaft has its axial direction along the center line CL and is connected to the propeller shaft 83 so that it can transmit power. Note that by positioning the gearbox 81 so that the input shaft is shifted to the left of the center line CL in the width direction of the rear body 3, a weight balance in the left-right direction is achieved with the second electric motor 73, which is positioned in the rear body 3 shifted to the right of the center line CL.

[0071] The rotational power of the second electric motor 73 is transmitted to the input shaft of a gearbox 81 located diagonally below and to the left of the second electric motor 73 via a fan belt or the like covered by a cover 35. The output shaft of the gearbox 81 is connected to a rear axle 82 and a propeller shaft 83. The propeller shaft 83 protrudes forward from the gearbox 81 so that its axial direction is aligned with the center line CL of the vehicle body 4, and its tip is connected to a front axle 84. The rotational power of the second electric motor 73 is transmitted to the front axle 84 via the gearbox 81 and the propeller shaft 83.

[0072] In the wheel loader 1 according to this embodiment, the battery unit is physically divided into two according to the system of the electric drive system, with a first battery 61 located in the front vehicle body 2 and a second battery 71 located in the rear vehicle body 3. By arranging battery units individually for the functional units to be driven in this way, the weight balance between the front vehicle body 2 and the rear vehicle body 3 is achieved, solving the problem of poor front-to-rear weight balance that occurs when a single battery unit is mounted only in the rear vehicle body, and the resulting deterioration in climbing performance.

[0073] The wheel loader 1 of this embodiment having the above-described configuration can be said to have the following configuration: That is, the wheel loader 1 includes a vehicle body 4 in which a front vehicle body 2 and a rear vehicle body 3 are connected so as to be able to swing left and right, drive wheels (front wheels 21, 21, rear wheels 31, 31) that drive the vehicle body 4, and a work implement (loader 5) supported by the front vehicle body 2, a first battery 61 arranged on the front vehicle body 2, a first drive system 60 that drives actuators (bucket cylinder 53, lift cylinders 54, 54) of the work implement (loader 5) with power supplied from the first battery 61, a second battery 71 arranged on the rear vehicle body 3, and a second drive system 70 that drives the drive wheels (front wheels 21, 21, rear wheels 31, 31) with power supplied from the second battery 71.

[0074] With the wheel loader 1 according to this embodiment, the first battery 61 that supplies power to the first drive system 60 that drives the actuators of the loader 5 arranged in the front body 2 is arranged in the front body 2, and the second battery 71 that supplies power to the second drive system 70 that drives the drive wheels is arranged in the rear body 3, so the weight balance between the front body 2 and the rear body 3 is optimized, making it possible to improve stability during driving. Furthermore, because two battery units, the first battery 61 and the second battery 71, are mounted on the vehicle, restrictions on placement due to the volume of the battery units are alleviated compared to when a single battery unit is mounted, and the battery capacity that can be mounted on the entire work vehicle can be easily increased.

[0075] In addition, in the wheel loader 1, the first drive system 60 includes a first electric motor 63 arranged in the front vehicle body 2, and the second drive system 70 includes a second electric motor 73 arranged in the rear vehicle body 3.

[0076] With a wheel loader 1 configured in this way, power conversion devices such as the first electric motor 63 and second electric motor 73, which receive power from batteries located in the front body 2 and rear body 3, respectively, can also be arranged in a well-balanced manner between the front body 2 and rear body 3. This makes it possible to improve the stability of the work vehicle when it is traveling.

[0077] Furthermore, in the wheel loader 1, the first battery 61 is disposed on one side (forward) of the front vehicle body 2 in the fore-and-aft direction relative to the first electric motor 63, and the second battery 71 is disposed on one side (rear) of the rear vehicle body 3 in the fore-and-aft direction relative to the second electric motor 73. As long as a weight balance can be achieved between the front vehicle body 2 and the rear vehicle body 3, the front-to-rear positions of the first battery 61 and the first electric motor 63 in the front vehicle body 2 may be interchanged. Similarly, the front-to-rear positions of the second battery 71 and the second electric motor 73 in the rear vehicle body 3 may also be interchanged. Note that by disposing the second battery 71 behind the second electric motor 73 in the rear vehicle body 3, the space within the bonnet 15 can be used effectively.

[0078] Furthermore, the positional relationship between the first battery 61 and the first electric motor 63 in the front vehicle body 2 and the positional relationship between the second battery 71 and the second electric motor 73 in the rear vehicle body 3 in the left-right direction of each vehicle body is not particularly limited. In this embodiment, as shown in FIG. 3 , in the front vehicle body 2, the first electric motor 63 is arranged so as to overlap with approximately the right half of the first battery 61 in the left-right direction. Furthermore, in the rear vehicle body 3, the second electric motor 73 is arranged so as to overlap with approximately the right half of the second battery 71 in the left-right direction. From the perspective of achieving such a compact arrangement, it is preferable that the batteries and motors in each of the front vehicle body 2 and the rear vehicle body 3 be arranged so as to overlap with each other at least partially in the left-right direction.

[0079] Furthermore, with regard to the positional relationship between the first battery 61 and the hydraulic oil tank 46 in the front vehicle body 2, the first battery 61 is disposed on one side (front side) of the hydraulic oil tank 46 in the fore-and-aft direction of the front vehicle body 2. In the front vehicle body 2, the positions of the first battery 61 and the hydraulic oil tank 46 may be interchanged.

[0080] In addition, in the wheel loader 1, the actuators are hydraulic actuators (bucket cylinder 53, lift cylinders 54, 54), the first drive system 60 is provided with a hydraulic oil tank 46 disposed in the front body 2 for storing hydraulic oil to be supplied to the hydraulic actuators (bucket cylinder 53, lift cylinders 54, 54), and the first battery 61 is disposed on one side of the front body 2 in the fore-and-aft direction relative to the hydraulic oil tank 46.

[0081] According to the wheel loader 1 configured in this way, it is possible to arrange the hydraulic equipment, which is heavy equipment other than the power conversion equipment, in a well-balanced manner.

[0082] In the wheel loader 1, the work machine (loader 5) has a pair of lift arms 51, 51 whose base ends are rotatably attached to the front vehicle body 2, and a bucket 52 rotatably attached to the tips of the pair of lift arms 51, 51. The hydraulic actuators include a pair of first hydraulic actuators (lift cylinders 54, 54) that rotate the pair of lift arms, and a second hydraulic actuator (bucket cylinder 53) that rotates the bucket 52.

[0083] With a wheel loader 1 configured in this way, the piping of hydraulic hoses and the routing of power lines to the hydraulic actuators of the loader 5 attached to the front body 2 can be completed within the front body 2. This makes it possible to eliminate the need for piping and wiring that crosses the front body 2 and rear body 3, eliminating the problem of piping and wiring being bent and damaged when the front body 2 and rear body 3 swing left and right relative to each other, and also improves the assembly efficiency of the work vehicle.

[0084] Furthermore, in the wheel loader 1, the first drive system 60 is provided with a control valve 47 that is disposed in the front body 2 and controls the supply and discharge of hydraulic oil to the first hydraulic actuator (lift cylinders 54, 54) and the second hydraulic actuator (bucket cylinder 53), and the control valve 47 is disposed on one side (lower side) of the front body 2 in the up-down direction relative to the first electric motor 63.

[0085] Furthermore, in the wheel loader 1, at least one of the control valve 47 and the first electric motor 63 is disposed above the hydraulic oil tank 46. In this embodiment, both the control valve 47 and the first electric motor 63 are disposed above the hydraulic oil tank 46, but, for example, only the control valve 47 may be disposed above the hydraulic oil tank 46. The relative positions of the first electric motor 63, hydraulic oil tank 46, and control valve 47 in the front vehicle body 2 can be changed taking into account the weight and volume of each component.

[0086] Furthermore, in the wheel loader 1, the first battery 61 is disposed in front of the control valve 47, and the control valve 47 is disposed vertically between the hydraulic oil tank 46 and the first electric motor 63. In other words, the control valve 47 is disposed at a position sandwiched between the hydraulic oil tank 46 and the first electric motor 63 on the top and bottom.

[0087] In addition, in the wheel loader 1, the control valve 47 is disposed above the hydraulic oil tank 46, and the hydraulic pump 45, which pressurizes the hydraulic oil stored in the hydraulic oil tank 46 to the first hydraulic actuator (lift cylinders 54, 54) and the second hydraulic actuator (bucket cylinder 53), is disposed offset from the control valve 47 in the width direction (left-right direction) of the front body 2.

[0088] With the wheel loader 1 configured as described above, the layout of hydraulic equipment such as control valves in the front body 2 can be designed to allow for efficient connection of pipes and the like so as not to interfere with power conversion equipment such as the first electric motor 63. Furthermore, by locating the hydraulic oil tank 46, which has a larger volume than the first electric motor 63 and becomes heavier due to the hydraulic oil stored therein, below the first electric motor 63, the space on top of the hydraulic oil tank 46 can be effectively utilized, making it possible to store hydraulic equipment such as the control valve 47 compactly in the front body 2.

[0089] Furthermore, in the wheel loader 1, the second drive system 70 includes a power distribution device (gear box 81) that distributes power transmitted from the second electric motor 73 in different directions, and the second electric motor 73 is disposed above the power distribution device (gear box 81). The drive wheels are a pair of front wheels 21, 21 attached to the front vehicle body 2 and a pair of rear wheels 31, 31 attached to the rear vehicle body 3, and the second drive system 70 includes a power distribution device (gear box 81) that distributes power transmitted from the second electric motor 73 to the pair of front wheels 21, 21 and the pair of rear wheels 31, 31, and the second electric motor 73 is disposed above the power distribution device (gear box 81).

[0090] Furthermore, in the wheel loader 1, the drive wheels are a pair of front wheels 21, 21 mounted on the front body 2 and a pair of rear wheels 31, 31 mounted on the rear body 3, a power distribution device (gearbox 81) distributes the power transmitted from the second electric motor to the pair of front wheels 21, 21 and the pair of rear wheels 31, 31, and the second electric motor 73 is positioned at a position offset in the width direction of the rear body 3 with respect to a power transmission shaft (propeller shaft 83) extending from the gearbox 81 towards the pair of front wheels 21, 21.

[0091] With a wheel loader 1 configured in this way, the rear vehicle body 3 can have a layout that allows for efficient connection of equipment related to driving the wheels, such as gearboxes, so as not to interfere with power conversion equipment, such as the second electric motor 73.

[0092] The above-described embodiment is an example of the present invention, and the work vehicle according to the present invention is not limited to the above-described embodiment. Therefore, even if it is an embodiment other than the above-described embodiment, various modifications can be made depending on the design, etc., as long as they do not deviate from the technical concept of the present invention. Furthermore, the effects described in this disclosure are merely examples and are not limiting, and other effects may also be obtained.

[0093] The present invention can take the following forms. (1) A work vehicle comprising: a vehicle body in which a front body and a rear body are connected so as to be able to swing freely left and right; drive wheels for driving the vehicle body; and a work implement supported on the front body, a first battery disposed in the front vehicle body; a first drive system that drives an actuator of the work machine using power supplied from the first battery; a second battery disposed in the rear vehicle body; a second drive system that drives the drive wheels using electric power supplied from the second battery; A work vehicle equipped with: (2) the first drive system includes a first electric motor disposed in the front body; The second drive system includes a second electric motor disposed in the rear body. The work vehicle described in (1) above. (3) the first battery is disposed on one side of the front vehicle body in the front-to-rear direction with respect to the first electric motor, The second battery is disposed on one side of the rear vehicle body in the front-rear direction relative to the second electric motor. The work vehicle described in (2) above. (4) the actuator is a hydraulic actuator; the first drive system includes a hydraulic oil tank that is disposed in the front vehicle body and stores hydraulic oil to be supplied to the hydraulic actuator; The first battery is disposed on one side of the front vehicle body in the front-to-rear direction with respect to the hydraulic oil tank. The work vehicle according to (2) or (3) above. (5) The hydraulic actuators include a first hydraulic actuator and a second hydraulic actuator; the first drive system includes a control valve that is disposed in the front vehicle body and controls the supply and discharge of hydraulic oil to the first hydraulic actuator and the second hydraulic actuator; The control valve is disposed on one side of the front vehicle body in the up-down direction with respect to the first electric motor. The work vehicle described in (4) above. (6) At least one of the control valve and the first electric motor is disposed above the hydraulic oil tank. The work vehicle described in (5) above. (7) the first battery is disposed in front of the control valve; The control valve is disposed between the hydraulic oil tank and the first electric motor in the vertical direction. The work vehicle according to (5) or (6) above. (8) the control valve is disposed above the hydraulic oil tank; a hydraulic pump that pumps hydraulic oil stored in the hydraulic oil tank to the first hydraulic actuator and the second hydraulic actuator, the hydraulic pump being disposed offset in the width direction of the front vehicle body relative to the control valve; A work vehicle according to any one of (5) to (7). (9) the second drive system includes a power distribution device that distributes power transmitted from the second electric motor in different directions; the second electric motor is disposed above the power distribution device; A work vehicle according to any one of (1) to (9). (10) the drive wheels are a pair of front wheels attached to the front vehicle body and a pair of rear wheels attached to the rear vehicle body, the power distribution device distributes the power transmitted from the second electric motor to the pair of front wheels and the pair of rear wheels, the second electric motor is disposed at a position shifted in the width direction of the rear vehicle body relative to a power transmission shaft that extends in the front-rear direction of the vehicle body and transmits the power distributed by the power distribution device to the pair of front wheels; The work vehicle according to (9) above. [Explanation of symbols]

[0094] 1 Wheel loader (work vehicle) 2 Front body 3 Rear body 4 Vehicle body 5 Loader 10 Driving Section 12 Driver's seat 13. Steering column 14 Handle 15. Bonnet 20 Front Frame 21 Front wheels (drive wheels) 30 rear frame 31 Rear wheels (drive wheels) 41 Pivot axis 42 Steering cylinder 45 Hydraulic Pump 46 Hydraulic oil tank 47 Control Valve 51 Lift arm 52 Bucket 53 Bucket cylinder (second hydraulic actuator) 54 Lift cylinder (first hydraulic actuator) 55 Bell crank 56 Connecting part 57 Related Links 60 First Drive System 61 First Battery 63 First electric motor 70 Second Drive System 72 Second Battery 73 Second electric motor 81 Gearbox (power distribution device) 83 Propeller shaft (power transmission shaft)

Claims

1. A work vehicle comprising: a vehicle body in which a front body and a rear body are connected so as to be able to swing freely left and right; drive wheels for driving the vehicle body; and a work implement supported on the front body, a first battery disposed in the front vehicle body; a first drive system that drives an actuator of the work machine using power supplied from the first battery; a second battery disposed in the rear vehicle body; a second drive system that drives the drive wheels using electric power supplied from the second battery; A work vehicle equipped with:

2. the first drive system includes a first electric motor disposed in the front body; the second drive system includes a second electric motor disposed in the rear body; The work vehicle according to claim 1.

3. the first battery is disposed on one side of the front vehicle body in the front-to-rear direction with respect to the first electric motor, the second battery is disposed on one side of the rear vehicle body in the front-rear direction with respect to the second electric motor, The work vehicle according to claim 2.

4. the actuator is a hydraulic actuator; the first drive system includes a hydraulic oil tank that is disposed in the front vehicle body and stores hydraulic oil to be supplied to the hydraulic actuator; The first battery is disposed on one side of the front vehicle body in the front-to-rear direction with respect to the hydraulic oil tank. The work vehicle according to claim 2 .

5. The hydraulic actuators include a first hydraulic actuator and a second hydraulic actuator, the first drive system includes a control valve that is disposed in the front vehicle body and controls the supply and discharge of hydraulic oil to the first hydraulic actuator and the second hydraulic actuator; the control valve is disposed on one side of the front vehicle body in the up-down direction with respect to the first electric motor, The work vehicle according to claim 4.

6. At least one of the control valve and the first electric motor is disposed above the hydraulic oil tank. The work vehicle according to claim 5.

7. the first battery is disposed in front of the control valve; The control valve is disposed between the hydraulic oil tank and the first electric motor in the vertical direction. The work vehicle according to claim 5.

8. the control valve is disposed above the hydraulic oil tank; a hydraulic pump that pressure-feeds the hydraulic oil stored in the hydraulic oil tank to the first hydraulic actuator and the second hydraulic actuator, the hydraulic pump being disposed offset in the width direction of the front vehicle body relative to the control valve; The work vehicle according to claim 5.

9. the second drive system includes a power distribution device that distributes power transmitted from the second electric motor in different directions; the second electric motor is disposed above the power distribution device; The work vehicle according to any one of claims 1 to 8.

10. the drive wheels are a pair of front wheels attached to the front vehicle body and a pair of rear wheels attached to the rear vehicle body, the power distribution device distributes the power transmitted from the second electric motor to the pair of front wheels and the pair of rear wheels; the second electric motor is disposed at a position shifted in the width direction of the rear vehicle body with respect to a power transmission shaft that extends in the front-rear direction of the vehicle body and transmits the power distributed by the power distribution device to the pair of front wheels; The work vehicle according to claim 9.

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