Work vehicle

Abstract

To provide a work vehicle which can have traveling stability during operation while sufficiently securing battery capacity.SOLUTION: A work vehicle comprises: a travel unit; an electric motor for travel which drives the travel unit; and a vehicle body which is travelably supported by the travel unit. The vehicle body includes a coupling device which can be coupled, when a work device performing a prescribed work is arranged at either one side of a front side and a rear side in a cross direction of the vehicle body, with the work device. A driving battery is directly or indirectly supported by the vehicle body to be capable of supplying the electric motor for travel with electric power. The driving battery includes: a first battery arranged in the vehicle body; and a second battery which is arranged at the other side of the front side and the rear side to sandwich the vehicle body between the second battery and the work device to be an opposite side of the work device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a work vehicle equipped with an electric motor that drives a traveling device. [Background technology]

[0002] Conventionally, work vehicles such as tractors have been equipped with a vehicle body supported by a traveling device, and a work device for performing a predetermined task is connected to the vehicle body with the work device located either on the front or rear side of the vehicle body. In addition, in this type of work vehicle, a balance weight is attached to the opposite side of the work device in the fore-and-aft direction (either the front or rear side of the vehicle body) to achieve a weight balance in the fore-and-aft direction of the work vehicle (see, for example, Patent Document 1). This allows the travelling device to come into proper contact with the ground, and the work vehicle can make the work device perform work properly while traveling within a work site (for example, a farm field). In recent years, electric work vehicles have been provided in which the drive source for driving the traveling device has been replaced by an electric motor instead of an internal combustion engine (engine) (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2024-2265 [Patent Document 2] Japanese Patent Application Publication No. 2024-32808 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when an electric motor is used as the drive source for driving the traveling device, a battery is required to power the electric motor, but since there is limited space available for batteries in a work vehicle such as a tractor, it is not possible to install an additional battery or a battery with a sufficient charge capacity, making it impossible to ensure sufficient work time (content). Furthermore, even if an additional battery can be installed, because batteries are heavy, even if weight balance is achieved when the working device is connected with a balance weight, the additional battery may disrupt the weight balance, resulting in a loss of traveling stability during work.

[0005] SUMMARY OF THE INVENTION The present invention provides a work vehicle that can ensure sufficient battery capacity while also ensuring stable running during work. [Means for solving the problem]

[0006] The present invention comprises a traveling device, a traveling electric motor that drives the traveling device, a vehicle body that is supported by the traveling device so that it can travel, the vehicle body having a coupling device that can couple a working device that performs a specified task while it is positioned on either the front or rear side of the vehicle body in the fore-and-aft direction, and a driving battery that is supported directly or indirectly on the vehicle body and can supply power to the traveling electric motor, the driving battery including a first battery that is positioned on the vehicle body, and a second battery that is positioned on the other side of the working device, either the front side or the rear side, across the vehicle body in the fore-and-aft direction. [Effects of the Invention]

[0007] According to the present invention, it is possible to ensure sufficient battery capacity while also improving running stability during work. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a left side view of a work vehicle according to an embodiment of the present invention, in which a coupled work implement is shown in imaginary lines. [Figure 2] FIG. 2 is a plan view of the work vehicle according to the embodiment, in which the coupled work implement is shown in phantom lines. [Figure 3] FIG. 3 is a perspective view of a second battery of the work vehicle according to the embodiment. [Figure 4] FIG. 4 is an exploded perspective view of the second battery of the work vehicle according to the embodiment. [Figure 5] Figure 5 is an enlarged cross-sectional view of the external terminal of the second battery of the work vehicle according to the embodiment and the main parts around the external terminal, in which the external terminal of the second battery is electrically connected to the connection terminal of the battery support part. [Figure 6] Figure 6 is an enlarged cross-sectional view of the external terminal of the second battery of the work vehicle according to the embodiment and the main parts around the external terminal, showing the main parts in a state where the external terminal of the second battery is electrically disconnected from the connection terminal of the battery support part. [Figure 7] FIG. 7 is a schematic perspective view of a coupling device (first coupling device) of the work vehicle according to the embodiment. [Figure 8] FIG. 8 is a perspective view of the battery support section and the second battery of the work vehicle according to the embodiment, showing a state in which the second battery is mounted on the battery support section. [Figure 9] FIG. 9 is a perspective view of the battery support section and the second battery of the work vehicle according to the embodiment, showing the second battery before it is mounted on the battery support section (disassembled state). [Figure 10] FIG. 10 is a schematic perspective view of a battery support portion of the work vehicle according to the embodiment. [Figure 11] FIG. 11 is a block diagram of a battery management system for a work vehicle (electric work vehicle) according to the embodiment, and is a system block diagram that includes a block diagram of the electrical system of the work vehicle. [Figure 12] FIG. 12 is a flowchart of information transmission processing of the work vehicle according to the embodiment. [Figure 13]FIG. 13 is a flowchart of request processing by the server of the battery monitoring system for a work vehicle (electric work vehicle) according to the embodiment. [Figure 14] FIG. 14 is an explanatory diagram illustrating replacement of the second battery of the work vehicle according to the embodiment using a transport vehicle equipped with a crane device. [Figure 15] FIG. 15 is an explanatory diagram of when the second battery of the work vehicle according to the embodiment is replaced using a transport vehicle equipped with a dedicated battery replacement device. [Figure 16] FIG. 16 is an explanatory diagram illustrating replacement of the second battery of the work vehicle according to the embodiment using a dedicated work implement connected to another work vehicle. [Figure 17] FIG. 17 is an explanatory diagram illustrating replacement of the second battery of the work vehicle according to the embodiment using a stationary charging device. [Figure 18] FIG. 18 is an explanatory diagram illustrating replacement of the second battery of the work vehicle according to the embodiment using a PTO-driven charging device. [Figure 19] FIG. 19 is a left side view of a work vehicle according to another embodiment of the present invention, with the coupled work implement shown in phantom lines. [Figure 20] FIG. 20 is a perspective view of a second battery and a battery support part of a work vehicle according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] A work vehicle and a battery management system for an electric work vehicle according to one embodiment of the present invention will be described below with reference to the drawings. In the following description of the work vehicle, the straight-ahead direction of the work vehicle (the direction in which it moves forward or backward straight) will be referred to as the longitudinal direction, the forward side in the longitudinal direction will be referred to as the front, and the backward side in the longitudinal direction will be referred to as the rear. Accordingly, the direction perpendicular to the longitudinal direction and the up-down direction and corresponding to the width of the work vehicle will be referred to as the lateral direction.

[0010] As shown in Figures 1 and 2, a work implement E that performs a predetermined task in a work site is coupled to the work vehicle 1. The work implement E is coupled to the work vehicle 1 while being positioned in front or behind (rear in Figures 1 and 2) the work vehicle 1. In this embodiment, the work vehicle 1 is an agricultural work vehicle (tractor) that is used in a farm field, which is the work site. 1 and 2, the work implement E is shown simplified with imaginary lines, but examples of the work implement E that can be connected to the work vehicle 1 include a rotary (cultivator) that tills the soil in the field, a plow that turns the soil over in the field, a soiler that breaks up clumps of soil in the field, a harrow, a ridge coating machine that coats ridges, a seeder that sows seeds in the field, a ridge maker that makes ridges, a broadcaster that spreads fertilizer and soil conditioner, a mulcher (mulcher) that mulches the ridges, a cultivator that weeds between the ridges, a flail mower that mows, and a harvester (digger) that digs up crops in the soil of the field. The work implement E connected to the work vehicle 1 can be replaced (changed) with another work implement E depending on the work content (purpose).

[0011] The work vehicle 1 of this embodiment is an electric work vehicle that drives an electric motor 3 with power supplied from a drive battery 5 to cause a working device E to perform a predetermined task while traveling. Specifically, the work vehicle 1 of this embodiment is equipped with a traveling device 2, a traveling electric motor 3 that drives the traveling device 2, a vehicle body 4 that is supported by the traveling device 2 so that it can travel, the vehicle body 4 having coupling devices 40, 41 that can couple a working device E that performs a predetermined task while it is positioned on either the front or rear side of the vehicle body 4 in the fore-and-aft direction, and a drive battery 5 that is supported directly or indirectly on the vehicle body 4 and can supply power to the traveling electric motor 3. The work vehicle 1 of this embodiment is equipped with an device electric motor 6 that drives the working device E. The work vehicle 1 of this embodiment is also equipped with a control device 7 that controls the power supply of the drive battery 5. The work vehicle 1 of this embodiment is also equipped with a transmitter 8a that is capable of wireless communication with the outside world. Accordingly, the work vehicle 1 of this embodiment is also equipped with a receiver 8b that is capable of wireless communication with the outside world. Furthermore, the work vehicle 1 is equipped with a position detection sensor S that transmits and receives signals to and from an external position detection sensor S, which will be described later.

[0012] Prior to describing the traveling device 2, the traveling electric motor 3, and the vehicle body 4, the drive battery 5 will be described. The drive battery 5 is connected to the traveling electric motor 3 via a power line L so as to be able to supply power. The drive battery 5 is also connected to the equipment electric motor 6 via a power line L so as to be able to supply power. An electrical circuit breaker (not shown) that opens and closes the electrical circuit in response to instructions from the control device 7 is provided on the power line L. This causes the supply of power to the traveling electric motor 3 and the equipment electric motor 6 to be stopped based on instructions from the control device 7. Note that the equipment electric motor 6 is used to drive the working device E that has dynamic functional units (to make the functional units function). Therefore, if the working device E does not have dynamic functional units, the electrical circuit breaker opens the electrical circuit of the power line L in response to instructions from the control device 7, and the power supply (power feed) from the drive battery 5 to the equipment electric motor 6 is stopped.

[0013] In this embodiment, the driving battery 5 includes a first battery 5A disposed on the vehicle body 4, and a second battery 5B disposed on the other of the front or rear sides (front in FIGS. 1 and 2) of the vehicle body 4, on the opposite side of the working implement E in the fore-and-aft direction. In other words, the work vehicle 1 has, as the driving battery 5, the first battery 5A which cannot be removed (replaced) and the second battery 5B which is replaceable. Accordingly, the work vehicle 1 is provided with a battery support part 9 which can support the second battery 5B, the battery support part 9 being connected to the vehicle body 4 and disposed on the front or rear side (front side in FIGS. 1 and 2).

[0014] The first battery 5A is a rechargeable secondary battery. In this embodiment, the first battery 5A is a lithium ion battery. The first battery 5A is a battery pack made up of a plurality of battery cells, and is capable of supplying a large amount of power. The first battery 5A has a positive external terminal The positive and negative external terminals are connected to a power line L that is connected to electrical equipment such as the electric motor 3 for driving.

[0015] The second battery 5B is also a chargeable and dischargeable secondary battery. In this embodiment, the second battery 5B is also a lithium-ion battery. As shown in Figures 3 and 4, the second battery 5B is an assembled battery made up of a plurality of battery cells 500, and is capable of supplying a large amount of power.

[0016] More specifically, the second battery 5B includes a plurality of battery modules 50, 50 electrically connected in series, each having a positive electrode module terminal Tma and a negative electrode module terminal Tmb, a battery case 51 that houses the plurality of battery modules 50, 50, and a positive electrode external terminal 53a and a negative electrode external terminal 53b.

[0017] The support mode of the second battery 5B (battery case 51) by the battery support section 9 is constant or approximately constant. Accordingly, in this embodiment, the lateral size (length) of the second battery 5B (battery case 51) when supported by the battery support section 9 is set to be equal to or less than the overall lateral width of the work vehicle 1. In other words, the second battery 5B is set to a size that fits within the overall width of the work vehicle 1 when lined up in the front-to-rear direction relative to the vehicle body 4. In this embodiment, the lateral size of a single second battery 5B (battery case 51) is set to be equal to or less than half the overall lateral width of the work vehicle 1. In other words, the lateral size of a single second battery 5B (battery case 51) is set to a size that allows two or more batteries to be placed within the overall width of the work vehicle 1.

[0018] In this embodiment, the battery case 51 has a cubic or rectangular parallelepiped appearance and constitutes the exterior of the second battery 5B. Specifically, the battery case 51 has a bottom 510 placed on the battery support 9, a top 511 that is spaced apart from the bottom 510 in the vertical direction and is positioned above the bottom 510, and a peripheral wall 512 that connects the outer periphery of the bottom 510 and the outer periphery of the top 511.

[0019] The bottom 510 and the top 511 are set to have the same shape and size in a plan view (viewed from the top to bottom direction). In this embodiment, the bottom 510 and the top 511 are rectangular in a plan view (viewed from the top to bottom direction). Note that although the top 511 is shown separated from the peripheral wall 512 and the bottom 510 in FIG. 4, the outer periphery of the top 511 is firmly connected to the peripheral wall 512 by welding or the like (see FIG. 3).

[0020] As the bottom portion 510 and the top portion 511 are formed in a rectangular shape in a plan view, the peripheral wall 512 is formed in a rectangular cylindrical shape. That is, the peripheral wall 512 includes a pair of first walls 512a, 512a spaced apart in the front-rear direction, and a pair of second walls 512b, 512b spaced apart in the horizontal direction, the pair of second walls 512b, 512b having both ends in the front-rear direction connected to the pair of first walls 512a, 512a. In this embodiment, one front end of each of the pair of second walls 512b, 512b in the front-rear direction is connected to a horizontal edge of one of the first walls 512a located on the front side and extending in the vertical direction, and one rear end of each of the pair of second walls 512b, 512b in the front-rear direction is connected to a horizontal edge of the other first wall 512a located on the rear side and extending in the vertical direction.

[0021] Accordingly, the distance between the pair of second walls 512b, 512b (the horizontal size of the first walls 512a, 512a) is set to be less than the overall horizontal width of the work vehicle 1 (in this embodiment, less than half the overall horizontal width of the work vehicle 1).

[0022] The multiple battery modules 50 are aligned and arranged in a battery case 51. In this embodiment, the multiple battery modules 50 are arranged one on top of the other in the vertical direction. The positive external terminal 53a is connected to a positive module terminal Tma of one of the two battery modules 50 located at both ends of the multiple battery modules 50 arranged electrically in series, and the negative external terminal 53b is connected to a negative module terminal Tmb of the other of the two battery modules 50 located at both ends of the multiple battery modules 50 arranged electrically in series. In this embodiment, the second battery 5B includes two battery modules 50. Accordingly, the positive external terminal 53a is connected to a positive module terminal Tma of one of the two battery modules 50, and the negative external terminal 53b is connected to a negative module terminal Tmb of the other of the two battery modules 50.

[0023] Each of the battery modules 50 is an assembled battery including a plurality of battery cells (single cells) 500 electrically connected in series. More specifically, the battery module 50 includes a plurality of battery cells 500 each having a positive terminal Ta and a negative terminal Tb, a module case 52 accommodating the battery cells 500, and a positive module terminal Tma and a negative module terminal Tmb. In each of the battery modules 50, the battery cells 500 are electrically connected via bus bars. As a result, the positive terminal Ta of one of the two battery cells 500 located at both ends of the battery cells 500 electrically arranged in series constitutes the positive module terminal Tma, and the negative terminal Tb of the other of the two battery cells 500 located at both ends of the battery cells 500 electrically arranged in series constitutes the negative module terminal Tmb.

[0024] 1 and 2, the second battery 5B is supported by the battery support portion 9. Accordingly, with the second battery 5B supported by the battery support portion 9, as shown in FIGS. 1, 2, and 5, the positive external terminal 53a and the negative external terminal 53b of the second battery 5B are electrically connected to the power lines L that connect to the traveling electric motor 3 and the device electric motor 6. In addition, the positive external terminal 53a and the negative external terminal 53b of the second battery 5B are also electrically connected to the positive external terminal 53a and the negative external terminal 53b of the first battery 5A via the power lines L.

[0025] The second battery 5B is replaceable. That is, the second battery 5B is detachable from the battery support part 9. Accordingly, as shown in FIGS. 3 and 4, the second battery 5B of this embodiment is provided with a hanging ring part 54 that protrudes from the upper surface of the battery case 51 (top part 511), and that is equipped with a hanging ring part 54 to which a hook 113c (see FIG. 15) of the crane device 113 is engaged. Furthermore, since the second battery 5B is detachable from the battery support part 9, it can be placed in a state where it is electrically connected to the power line L and a state where it is electrically disconnected from the power line L.

[0026] Specifically, the second battery 5B is attachable to and detachable from the battery support part 9 in the vertical direction. Based on this premise, as shown in FIGS. 5 and 6, the positive external terminal 53a and the negative external terminal 53b of the second battery 5B are configured to be attachable to and detachable from the positive connecting terminal 92a and the negative connecting terminal 92b of the battery support part 9 in the vertical direction. In this embodiment, the positive external terminal 53a and the negative external terminal 53b of the second battery 5B and the positive connecting terminal 92a and the negative connecting terminal 92b of the battery support part 9 are configured to be attachable and detachable in the vertical direction. That is, in the second battery 5B, the positive external terminal 53a has either a convex portion extending in the vertical direction or a concave portion recessed in the vertical direction, and the negative external terminal 53b has either a convex portion extending in the vertical direction or a concave portion recessed in the vertical direction. In contrast, in the battery support part 9, the positive connecting terminal 92a has either a convex portion extending in the vertical direction or a concave portion recessed in the vertical direction. The negative electrode connecting terminal 92b has the other of a protrusion extending in the vertical direction or a recess recessed in the vertical direction.

[0027] In this embodiment, both the positive external terminal 53a and the negative external terminal 53b of the second battery 5B have recesses 530a, 530b recessed in the vertical direction, and both the positive electrode connecting terminal 92a and the negative electrode connecting terminal 92b of the battery support part 9 have protrusions 920a, 920b extending in the vertical direction. The positive electrode external terminal 53a and the negative electrode external terminal 53b (recesses 530a, 530b) of the second battery 5B and the positive electrode connecting terminal 92a and the negative electrode connecting terminal 92b (protrusions 920a, 920b) of the battery support part 9 are formed so that, when fitted together, the positive electrode external terminal 53a and the negative electrode external terminal 53b (inner peripheral surfaces of the recesses 530a, 530b) of the second battery 5B are in close contact with the positive electrode connecting terminal 92a and the negative electrode connecting terminal 92b (outer peripheral surfaces of the protrusions 920a, 920b) of the battery support part 9. As a result, when the positive external terminal 53a and negative external terminal 53b of the second battery 5B are fitted with the positive connection terminal 92a and negative connection terminal 92b of the battery support part 9 (convex-concave fitted state), the outer peripheral surface and inner peripheral surface are in close contact and electrically connected.

[0028] In this embodiment, assuming that the positive external terminal 53a and the negative external terminal 53b of the second battery 5B approach (connect) the positive connection terminal 92a and the negative connection terminal 92b of the battery support part 9 from above, the recesses 530a, 530b of the positive external terminal 53a and the negative external terminal 53b of the second battery 5B are formed in a tapered shape that expands in diameter from the upper side to the lower side, and the protrusions 920a, 920b of the positive connection terminal 92a and the negative connection terminal 92b of the battery support part 9 are formed in a tapered shape that narrows from the lower side to the upper side.

[0029] As a result, when the second battery 5B is lowered from an upper position of the battery support part 9, the small-diameter tips of the convex parts 920a, 920b of the positive electrode connecting terminal 92a and the negative electrode connecting terminal 92b lead and enter toward the large-diameter openings of the positive electrode external terminal 53a and the negative electrode external terminal 53b (openings with a larger diameter than the tips of the convex parts 920a, 920b), and the inner surfaces of the concave parts 530a, 530b of the positive electrode external terminal 53a and the negative electrode external terminal 53b are guided by the tapered outer surfaces of the convex parts 920a, 920b of the positive electrode connecting terminal 92a and the negative electrode connecting terminal 92b, and finally the outer and inner surfaces come into surface contact (close contact) and are electrically connected.

[0030] The second battery 5B is configured so that, when supported by the battery support part 9, the positive external terminal 53a and the negative external terminal 53b of the second battery 5B are fitted (convex-concave fitted) with the positive connecting terminal 92a and the negative connecting terminal 92b of the battery support part 9. The positive external terminal 53a and the negative external terminal 53b of the second battery 5B are disposed in accordance with the arrangement (position and height) of the positive connecting terminal 92a and the negative connecting terminal 92b of the battery support part 9.

[0031] In this embodiment, the positive external terminal 53a and the negative external terminal 53b of the second battery 5B are disposed outside the outer circumferential surface of the peripheral wall 512 of the battery case 51. In this embodiment, the positive external terminal 53a and the negative external terminal 53b (recesses 530a, 530b) of the second battery 5B are fixed to the other second wall 512b on the rear side in the front-to-rear direction, and are located outside (on the rear side) of the second wall 512b.

[0032] Accordingly, the second battery 5B is provided with a terminal cover part 55 that covers the positive external terminal 53a and the negative external terminal 53b (recesses 530a, 530b) from above so that the positive external terminal 53a and the negative external terminal 53b (recesses 530a, 530b) are accessible from above (below). That is, the terminal cover part 55 covers the positive external terminal 53a and the negative external terminal 53b from above, while forming an opening that exposes the positive external terminal 53a and the negative external terminal 53b (recesses 530a, 530b) from below. The driving battery 5 (first battery 5A and second battery 5B) is as described above.

[0033] 1 and 2, the traveling device 2 of this embodiment is a tire-type traveling device and includes front wheels 2F and rear wheels 2R spaced apart in the fore-and-aft direction. The front wheels 2F and rear wheels 2R are each arranged as a pair spaced apart in the lateral direction (vehicle width direction). That is, the traveling device 2 includes a pair of front wheels 2F, 2F arranged to sandwich the vehicle body 4 in the lateral direction, and a pair of rear wheels 2R, 2R arranged rearward of the pair of front wheels 2F, 2F in the fore-and-aft direction and to sandwich the vehicle body 4 in the lateral direction. In the work vehicle 1 of this embodiment, each of the pair of front wheels 2F, 2F is a steered wheel that is operated by an operating device 46 (steering wheel), and each of the pair of rear wheels 2R, 2R is a drive wheel that is driven by an electric traveling motor 3. The traveling device 2 of the work vehicle 1 may be a so-called 4WD (four-wheel drive) in which the pair of front wheels 2F, 2F are steered wheels and driven together with the pair of rear wheels 2R, 2R.

[0034] The vehicle body 4 has a vehicle body frame 42 that extends in the front-to-rear direction and supports the first battery 5A. The vehicle body 4 also has a hood 43 that covers the equipment on the vehicle body frame 42 from above and the sides. The work vehicle 1 is a passenger vehicle and has a driver's seat 44 located behind the hood 43. The work vehicle 1 also has a protection mechanism 45 that protects the driver's seat 44.

[0035] 1, the body frame 42 includes a front frame 420 disposed on the front side in the longitudinal direction, and a casing 31 of the drive transmission device 30 that transmits the output of the traveling electric motor 3 to the rear wheel 2R. Specifically, the body frame 42 is configured by the front frame 420 as a structural body, and the casing 31 that houses the transmission mechanism of the drive transmission device 30 and is connected directly or indirectly to the front frame 420.

[0036] The traveling electric motor 3 is disposed on the front frame 420. That is, the traveling electric motor 3 is fixed to the front frame 420. In this embodiment, the casing 31 of the drive transmission device 30 is connected to the traveling electric motor 3. Therefore, the drive transmission device 30 is indirectly connected to the front frame 420 via the traveling electric motor 3, and is disposed on the rear side of the front frame 420. The transmission mechanism includes a clutch mechanism and a gear mechanism connected to the output shaft of the traveling electric motor 3, and distributes and transmits the output of the traveling electric motor 3 to the pair of rear wheels 2R, 2R.

[0037] The front frame 420 supports the first battery 5A of the drive batteries 5. That is, the first battery 5A is disposed on the front frame 420 and fixed to the front frame 420 in an undetachable manner. That is, the case of the first battery 5A is fixed to the vehicle body frame 42 (front frame 420). The first battery 5A is disposed within the hood 43. That is, the hood 43 faces the first battery 5A laterally and up and down and covers the first battery 5A.

[0038] In this embodiment, the traveling electric motor 3 is disposed below the first battery 5A. The front frame 420 supports the first battery 5A as well as devices such as a radiator He that cools the traveling electric motor 3 and the drive battery 5 (first battery 5A). These devices such as the radiator He are disposed in front of the first battery 5A and are disposed inside the hood 43 together with the first battery 5A. As a result, the traveling electric motor 3 and the drive battery 5 (first battery 5A) are disposed within half or approximately half of the area on the front side in the fore-and-aft direction of the body frame 42.

[0039] The first battery 5A is disposed between the front wheels 2F (a pair of front wheels 2F, 2F) and the rear wheels 2R (a pair of rear wheels 2R, 2R) in the front-rear direction. Specifically, the center of gravity G of the first battery 5A is located between the front wheels 2F (a pair of front wheels 2F) and the rear wheels 2R (a pair of rear wheels 2R, 2R) in the front-rear direction.

[0040] The protection mechanism 45 of this embodiment is a so-called cabin that covers the driver's seat 44 and defines the driver's cab DR. Accordingly, various devices (operation devices 46 (steering wheel and operation lever), a display device 47 described later, etc.) are arranged in the driver's cab DR (inside the protection mechanism 45).

[0041] The driver's seat 44 and the protection mechanism 45 are located above the body frame 42 and are supported by the body frame 42. Specifically, the driver's seat 44 and the protection mechanism 45 are located above the casing 31 of the drive transmission device 30 within the body frame 42 and are fixed to the casing 31. As a result, the driver's seat 44 and the protection mechanism 45 are located on half or approximately half of the area on the rear side in the fore-and-aft direction of the body frame 42. In addition, devices such as the operating device 46 and the display device 47 arranged in the driver's cab DR are also located on half or approximately half of the area on the rear side in the fore-and-aft direction of the body frame 42.

[0042] The driver's seat 44 is disposed between the front wheels 2F and the rear wheels 2R in the front-to-rear direction. Devices such as the operating device 46 and the display device 47 are disposed in front of the driver's seat 44 so that an operator seated in the driver's seat 44 can operate them. As a result, the center of gravity of the protection mechanism 45, and the driver's seat 44 and devices disposed within the protection mechanism 45 when viewed as a whole, is located between the front wheels 2F and the rear wheels 2R in the front-to-rear direction, and the center of gravity of the entire vehicle body 4 is located between the front wheels 2F and the rear wheels 2R in the front-to-rear direction.

[0043] As described above, the center of gravity of the entire body 4 and the center of gravity G of the first battery 5A are located between the front wheel 2F and the rear wheel 2R, so that the load of the structure supported by the body frame 42 does not act excessively on either the front wheel 2F or the rear wheel 2R, but is distributed and acts on the front wheel 2F and the rear wheel 2R.

[0044] The coupling devices 40, 41 are attached to the body frame 42. A working device E is directly or indirectly coupled to the coupling devices 40, 41. The working device E coupled to the coupling devices 40, 41 is disposed on either the front or rear side in the longitudinal direction of the body 4. The work vehicle 1 is equipped with support portion coupling devices 48a, 48b for coupling the battery support portion 9 that supports the second battery 5B, the support portion coupling devices 48a, 48b being attached to the body frame 42. The battery support portion 9 (second battery 5B) coupled to the support portion coupling devices 48a, 48b is disposed on the other side of the front or rear side in the longitudinal direction of the body 4.

[0045] Here, the coupling devices 40, 41 are attached to at least one of the front end and the rear end of the body frame 42, and the support portion coupling devices 48a, 48b are attached to at least the other of the front end and the rear end of the body frame 42. In other words, the coupling device 40 is attached to either the front end or the rear end of the body frame 42, and the support portion coupling devices 48a, 48b are attached to the other of the front end or the rear end of the body frame 42.

[0046] In this embodiment, the coupling devices 40, 41 are attached to the front and rear ends of the body frame 42, respectively, and the support portion coupling devices 48a, 48b are also attached to the front and rear ends of the body frame 42. That is, the support portion coupling device 48a corresponding to the coupling device 41 attached to the rear end of the body frame 42 is attached to the front end of the body frame 42, and the support portion coupling device 48b corresponding to the coupling device 41 attached to the front end of the body frame 42 is attached to the rear end of the body frame 42.

[0047] The support part connecting devices 48a and 48b are dedicated devices for connecting the battery support part 9, and may be configured separately from the connecting devices 40, 40. The connecting devices 40 and 41 for connecting the device E also serve as support portion connecting devices 48a and 48b for connecting the battery support portion 9.

[0048] Therefore, the coupling devices 40, 41 of this embodiment can couple both the working device E and the battery support part 9, and during work, either the working device E or the battery support part 9 is coupled. Note that, because the coupling devices 40, 41 also serve as the support part coupling devices 48a, 48, in the following explanation, the support part coupling devices 48a, 48b will be explained as the coupling devices 40, 41 to avoid duplication. That is, in the following explanation, the coupling devices 40, 41 can be read as the support part coupling devices 48a, 48b.

[0049] In this embodiment, the coupling device (hereinafter referred to as the first coupling device) 40 attached to the front end of the body frame 42 and the coupling device (hereinafter referred to as the second coupling device) 41 attached to the rear end of the body frame 42 may have the same form, but in this embodiment they have different forms.

[0050] 7, in the work vehicle 1 of this embodiment, the first coupling device 40 has a mounting surface 401a for mounting the working device E, the mounting surface 401a facing forward at a position a predetermined distance forward of the front end of the body frame 42 (front frame 420). The first coupling device 40 supports the working device E attached to the mounting surface 401a, maintaining it in a fixed position.

[0051] Specifically, the first coupling device 40 includes an arm 400 extending forward from the front end of the body frame 42 (front frame 420), and a coupling base 401 coupled to the front end of the arm 400. The first coupling device 40 (arm 400, coupling base 401) may be integrally molded by casting or the like, or may be integrally molded by combining plate materials or the like by welding or the like. The first coupling device 40 (arm 400, coupling base 401) of this embodiment is integrally molded by combining plate materials or the like by welding or the like.

[0052] Specifically, the arm 400 in this embodiment is formed in a plate shape and has a thickness in the lateral direction. The first connecting device 40 has two arms 400. The two arms 400 are arranged with a gap in the lateral direction. The connecting base 401 is formed in a plate shape and has a mounting surface 401a facing forward, which is a flat mounting surface 401a that extends in the vertical and horizontal directions. Accordingly, the front ends of the arms 400 are connected to the surface of the connecting base 401 opposite (the back side) to the mounting surface 401a. In the first connecting device 40, the connecting base 401 has a plurality of through holes H that penetrate in the front-rear direction, through which bolts B that secure the working device E are inserted. In this embodiment, since the arm 400 is formed in a plate shape that has a thickness in the lateral direction, the first connecting device 40 includes reinforcing ribs 402 to increase rigidity in the lateral direction (to reinforce the arm 400).

[0053] As described above, the first connecting device 40 is a structure, and therefore the working device E attached to the attachment surface 401a cannot move up and down (raise and lower), and is positioned at a fixed position. Therefore, when it is necessary to raise and lower the working device E to be connected, an intermediate device (for example, a three-point linkage device) that can be connected to the working device E and has the necessary functions such as raising and lowering the working device E is attached to the first connecting device 40 (attachment surface 401a). In other words, the working device E may be indirectly connected to the first connecting device 40 via an adapter device.

[0054] 1 and 2, the second connecting device 41 is a so-called three-point link, and supports the connected working device E so that it can be raised and lowered. Specifically, the second connecting device 41 (three-point link) is a pair of lower links 410, 411 extending rearward from the rear end of the body frame 42. and a top link 411 extending rearward from the rear end of the body frame 42, the top link 411 being positioned higher than and between the pair of lower links 410, 410. The second connecting device 41 (three-point link) includes an actuator that rotates the pair of lower links 410, 410.

[0055] Each of the pair of lower links 410 has a base end and a tip end, and the base end is rotatably connected to the rear end of the body frame 42 about an axis extending in the lateral direction. Similarly, the top link 411 has a base end and a tip end, and the base end is rotatably connected to the rear end of the body frame 42 about an axis extending in the lateral direction.

[0056] The tip ends of the pair of lower links 410, 410 and the tip end of the top link 411 are each configured to be able to directly or indirectly lock onto the working device E. The tip ends of the pair of lower links 410, 410 and the tip end of the top link 411 lock onto a hitch device Ea that can lock onto the working device E. Although not shown, the tip ends of the pair of lower links 410, 410 and the tip end of the top link 411 can also directly lock onto the working device E. The second connecting device 41 raises and lowers the connected working device E by rotating the lower links 410, 410 with an actuator not shown.

[0057] In the work vehicle 1 of this embodiment, the electric motor 6 for equipment has an output shaft that is supported at the rear end of the body frame 42 so that the output shaft extends rearward. Accordingly, in the work vehicle 1 of this embodiment, the output shaft of the electric motor 6 for equipment is connected via a universal joint 60 to a work device E (work device E that requires rotational drive) supported by the second connecting device 41.

[0058] 1 and 2, the battery support part 9 is detachably connected to the connecting devices 40, 41 (first connecting device 40, second connecting device 41) on the opposite side in the front-to-rear direction to the connecting devices 40, 41 to which the working device E is connected. In this example, the working device E is connected (locked) to the second connecting device 41 on the rear side in the front-to-rear direction, so the battery support part 9 is connected to the first connecting device 40 on the front side in the front-to-rear direction.

[0059] As shown in Figures 8 and 9, the battery support part 9 of this embodiment is configured to be able to support two or more second batteries 5B. The battery support part 9 is configured to be able to support two or more second batteries 5B lined up in the width direction. In this embodiment, the battery support part 9 is configured to be able to support two second batteries 5B. Accordingly, the battery support part 9 is configured to be able to support two second batteries 5B, 5B lined up in the horizontal direction.

[0060] 9, the battery support part 9 includes a connecting part 90 connected to the connecting devices 40, 41, and a battery mounting part 91 on which the second battery 5B can be mounted, the battery mounting part 91 being connected to the connecting part 90. The battery support part 9 of this embodiment includes connection terminals 92a, 92b connectable to the external terminals 53a, 53b of the second battery 5B. Specifically, the battery support part 9 includes a positive electrode connection terminal 92a and a negative electrode connection terminal 92b connectable to the positive electrode external terminal 53a and the negative electrode external terminal 53b of the second battery 5B.

[0061] The connecting portion 90 is configured to fit the shapes of the connecting devices 40, 41 so as to be connectable to the connecting devices 40, 41. The battery support portion 9 shown in Fig. 9 is configured so as to be connectable to the connecting base 401 of the first connecting device 40 of this embodiment. That is, the connecting portion 90 connected to the first connecting device 40 is fixed to the connecting base 401 (first connecting device 40) by screwing a bolt B inserted into a through hole H of the connecting base 401 while overlapping the connecting portion 90 with the connecting base 401 in the front-to-rear direction.

[0062] In contrast, the battery mounting portion 91 has a common configuration regardless of the form of the connecting devices 40, 41. More specifically, as shown in Figures 9 and 10, the battery mounting portion 91 includes a base portion 910 on which the bottom portion 510 of the second battery 5B (battery case 51) is mounted, and a restricting wall 911 erected on the upper surface of the base portion 910, which restricts movement of the second battery 5B placed on the base portion 910 in the front-rear and lateral directions.

[0063] The base portion 910 is formed in a plate shape and is arranged so that the plate thickness is in the vertical direction. The base portion 910 is set to a size that allows at least one second battery 5B to be arranged therein in a plan view. In this embodiment, the base portion 910 is set to a size that allows two or more (two in this embodiment) second batteries 5B to be arranged side by side in the horizontal direction. More specifically, the base portion 910 is set to a size that allows two second batteries 5B to be arranged side by side with a gap between them in the horizontal direction. In this embodiment, the base portion 910 is formed in a rectangular shape with its long sides in the horizontal direction in a plan view (viewed from the vertical direction).

[0064] The restricting wall 911 is formed in an annular shape when viewed from the top-bottom direction, and surrounds the lower end of the peripheral wall 512 of the second battery 5B. In the present embodiment, the peripheral wall 512 of the second battery 5B is formed in a rectangular cylindrical shape by a pair of first walls 512a and a pair of second walls 512b, and therefore the restricting wall 911 includes a pair of first restricting walls 912 that face the pair of first walls 512a from the outside, and a pair of second restricting walls 913 that face the pair of second walls 512b from the outside. Since the battery support portion 9 of this embodiment is capable of accommodating two second batteries 5B, the regulating wall 911 includes a pair of first regulating walls 912, 912 and a pair of second regulating walls 913, 913 for one second battery 5B, and a pair of first regulating walls 912, 912 and a pair of second regulating walls 913, 913 for the other second battery 5B.

[0065] For each of the first and second batteries 5B, a pair of first restriction walls 912 are arranged along both ends of the base portion 910 in the front-rear direction and protrude upward from the upper surface of the base portion 910. For each of the second batteries 5B and the other second battery 5B, a pair of second restriction walls 913 are arranged with a gap in the lateral direction. In this embodiment, since the two second batteries 5B are arranged with a gap in the lateral direction, one of the pair of second restriction walls 913 is arranged along a lateral edge (an edge extending in the front-rear direction) of the base portion 910, and the other of the pair of second restriction walls 913 is arranged between the two second batteries 5B arranged side by side.

[0066] In this embodiment, the other second restriction wall 913 for one second battery 5B and the other second restriction wall 913 for the other second battery 5B are integrated. That is, a plate P is erected on the upper surface of the base portion 910 so as to be positioned between the two second batteries 5B, and this plate P constitutes the other second restriction wall 913 for one second battery 5B and the other second restriction wall 913 for the other second battery 5B.

[0067] One first restriction wall 912 for one second battery 5B and one first restriction wall 912 for the other second battery 5B are continuously aligned side by side in the horizontal direction, and the other first restriction wall 912 for the other second battery 5B and the other first restriction wall 912 for the other second battery 5B are continuously aligned side by side in the horizontal direction. The inner surfaces (surfaces facing the second battery 5B) of the pair of first restriction walls 912, 912 and the pair of second restriction walls 913, 913 each include an inclined surface 914 that slopes inward (toward the second battery 5B) from the upper end downward. As a result, the insertion opening (fitting opening) for the second battery 5B defined by the peripheral wall 512 (the pair of first restriction walls 912, 912 and the pair of second restriction walls 913, 913) expands upward, and the inclined surface 914 forms a guide surface for guiding the second battery 5B into the restriction wall 911 (toward the lower end). is doing.

[0068] As a result, the battery support section 9 can lower the second battery 5B lifted by the crane device 113 (see, for example, FIGS. 14 and 15 ) to insert (fit) the second battery 5B (battery case 51) into the annular restricting wall 911. In particular, since the first restricting walls 912, 912 and the second restricting walls 913, 913 have inclined surfaces 914, even if the center of the second battery 5B does not coincide with the center of the area surrounded by the restricting wall 911 (the area in which the second battery 5B is disposed), the second battery 5B (battery case 51) can be accommodated in the annular restricting wall 911 by lowering while contacting the inclined surfaces 914. In addition, the battery support portion 9 can remove the second battery 5B (battery case 51) from within the restricting wall 911 by lifting the second battery 5B housed within the annular restricting wall 911 with the crane device 113 (raising the second battery 5B placed on the base portion 910).

[0069] For each of the first battery 912 for the first battery 5B and the second battery 5B, the thickness in the front-rear direction of the other first restriction wall 912 located on the rear side in the front-rear direction is set to be thicker than the thickness of the first restriction wall 912 located on the front side. For each of the first battery 5B and the second battery 5B, the height in the up-down direction of the other first restriction wall 912 located on the rear side in the front-rear direction is set to be higher than the height of the first restriction wall 912 located on the front side. The lower ends of the pair of first restriction walls 912, 912 are connected to the base portion 910, so their positions in the up-down direction (height levels) are the same. Therefore, for each of the first battery 5B and the second battery 5B, the upper end of the other first restriction wall 912 located on the rear side in the front-rear direction is positioned higher than the upper end of the first first restriction wall 912 located on the front side. In other words, the other first restriction wall 912 protrudes upward beyond the upper end of the first first restriction wall 912. The connecting portion 90 is connected to the outer surface of the other first restricting wall 912 .

[0070] Furthermore, for each of the first battery 5B and the other second battery 5B, a recess 915 into which the terminal cover 55 of the second battery 5B can be inserted and removed in the vertical direction is formed in the horizontal center of the inner surface of the other first restriction wall 912. That is, the other first restriction wall 912 has the recess 915 formed so as to divide the inclined surface 914 in half in the horizontal direction. As a result, in the other first restriction wall 912, inclined surfaces 914 are formed on both sides of the horizontal recess 915.

[0071] As shown in Figures 5, 6, and 10, the recess 915 is a terminal installation surface 915a on which the connection terminals 92a, 92b are installed, and is defined by: a flat terminal installation surface 915a facing upward; a first plane 915b standing from the rear edge of the terminal installation surface 915a in the front-to-rear direction; and a pair of second planes 915c, 915c extending forward from both lateral ends of the first plane 915b and also connected to both lateral ends of the terminal installation surface 915a.

[0072] 5 and 6, a positive electrode connection terminal 92a and a negative electrode connection terminal 92b are arranged on the terminal installation surface 915a as connection terminals 92a, 92b, spaced apart in the horizontal direction. The positive electrode connection terminal 92a and the negative electrode connection terminal 92b are connected to a power line L connected to the electric traction motor 3. In this embodiment, the battery support part 9 is detachable from the first coupling device 40. Accordingly, the power lines connected to the positive electrode connection terminal 92a and the negative electrode connection terminal 92b are connected to the power line L on the vehicle body 4 side via a connector C1 (see FIG. 1).

[0073] In the work vehicle 1 of this embodiment, as described above, the working device E is disposed either at the front or rear of the vehicle body 4, and the second battery 5B is disposed on the opposite side of the working device E in the front-to-rear direction. 1, the electric power lines L on the vehicle body 4 side connected to the traveling electric motor 3 and the like have a first connector C1 for connecting to the electric power lines connected to the positive electrode connection terminal 92a and the negative electrode connection terminal 92b of the battery support part 9 connected to the first coupling device 40, and a second connector C2 for connecting to the electric power lines connected to the positive electrode connection terminal 92a and the negative electrode connection terminal 92b of the battery support part 9 connected to the second coupling device 41. The first connector C1 is arranged near the front end of the vehicle body frame 42, and the second connector C2 is arranged near the rear end of the vehicle body frame 42.

[0074] 5 and 6, as described above, the protrusions 920a, 920b of the positive electrode connecting terminal 92a and the negative electrode connecting terminal 92b are tapered upward. As a result, in the battery support part 9 of this embodiment, when the second battery 5B (battery case 51) is inserted (fitted) into the annular restricting wall 911, the positive electrode external terminal 53a of the second battery 5B is fitted into the positive electrode connecting terminal 92a to be electrically connected, and the negative electrode external terminal 53b of the second battery 5B is fitted into the negative electrode connecting terminal 92b to be electrically connected. Furthermore, in the battery support part 9 of this embodiment, when the second battery 5B is removed, the positive electrode external terminal 53a of the second battery 5B is detached from the positive electrode connecting terminal 92a to be electrically disconnected, and the negative electrode external terminal 53b of the second battery 5B is detached from the negative electrode connecting terminal 92b to be electrically connected.

[0075] 8 and 9, the work vehicle 1 of this embodiment is provided with a drop-off prevention fitting 93 that prevents the second battery 5B supported by the battery support part 9 from floating up (disconnecting the electrical connection between the positive external terminal 53a and the positive connecting terminal 92a, and disconnecting the electrical connection between the negative external terminal 53b and the negative connecting terminal 92b). In this embodiment, the drop-off prevention fitting 93 is placed on the top part 511 of the second battery 5B and then fixed (with screws in this embodiment) to the battery support part 9.

[0076] Here, the weight of the second battery 5B supported by the battery support part 9 is set according to the weight of the working device E arranged on the opposite side in the front-to-rear direction. In this embodiment, the battery support part 9 can accommodate two second batteries 5B, and therefore the total weight of these two batteries is set taking into account the total weight of the working device E arranged on the opposite side (rear side).

[0077] Depending on the function, the working implement E may be coupled to the coupling devices 40, 41 while being biased in the width direction relative to the vehicle body 4. As described above, there are various types of working implement E, and depending on the type of working implement E, a part of the working implement E (for example, a functional part that performs a predetermined task (function) on the ground) or the entire working implement E may be coupled to the coupling devices 40, 41 in a state where it is biased laterally relative to the vehicle body 4 (a state where the lateral center is misaligned with the lateral center of the work vehicle 1).

[0078] In light of this, the battery support part 9 is configured to be able to support the second battery 5B on the opposite side to the biased side in the lateral direction of the working device E relative to the body 4. In other words, the second battery 5B is disposed on the opposite side of the battery support part 9 in the biased direction of the working device E relative to the body 4.

[0079] In the battery support section 9 of this embodiment, the two second batteries 5B, 5B can be arranged symmetrically with respect to the center line extending in the longitudinal direction of the vehicle body 4. Therefore, when the battery support section 9 is supporting two second batteries 5B, the weight balance is achieved in the lateral direction. In contrast, when the battery support section 9 is supporting one of the two second batteries 5B, the load of the second battery 5B acts on one or the other lateral side of the center line extending in the longitudinal direction of the vehicle body 4 as the reference (boundary). Therefore, when working, When a part of the device E (for example, a functional part that performs a specified task (function) on the ground) or the entire working device E is biased laterally (widthwise) relative to the body 4 (a state in which the lateral center is misaligned with the lateral center of the work vehicle 1), the second battery 5B is positioned only on the opposite side of the battery support part 9 from the bias direction of the working device E relative to the body 4, thereby achieving lateral weight balance (so-called roll direction balance) in relation to the working device E.

[0080] In order to recognize the charge amount (remaining charge) and power supply state (current value) of the first battery 5A and the second battery 5B, the work vehicle 1 is equipped with voltage sensors SV1 and SV2 that detect the voltage of the first battery 5A and the second battery 5B, and current sensors SA1 and SA2 that detect the current values ​​of the first battery 5A and the second battery 5B, as shown in FIG. 11. The voltage sensors SV1 and SV2 and the current sensors SA1 and SA2 are provided on the first battery 5A and the second battery 5B, respectively, or are arranged on a power line connected to the first battery 5A or the second battery 5B. That is, in the case of a typical battery pack, the battery pack is charged and discharged while placed in a fixed position, so the battery pack is equipped with voltage sensors SV1 and SV2 and current sensors SA1 and SA2. In this embodiment, the first battery 5A is fixed to the vehicle body frame 42 and placed in a fixed position, so it is equipped with a voltage sensor (hereinafter referred to as a first voltage sensor) SV1 and a current sensor (hereinafter referred to as a first current sensor) SA1. In contrast, the second battery 5B is configured to be detachable (replaceable), and therefore a voltage sensor (hereinafter referred to as the second voltage sensor SV2) and a current sensor (hereinafter referred to as the second current sensor SA2) that measure the voltage and current of the second battery 5B are disposed on the power line L connected to the second battery 5B. Note that a protection circuit for preventing overcharging and the like is provided in each of the first battery 5A and the second battery 5B.

[0081] The control device 7 controls the power supply to the drive batteries 5 (first battery 5A and second battery 5B). That is, the control device 7 includes a battery control system BMS. In this embodiment, the control device 7 includes not only the battery control system BMS but also an electronic control unit ECU that controls the drive of the device. Note that in this embodiment, the battery control system BMS and the electronic control unit ECU are not separated, but are collectively referred to as the control device 7.

[0082] The control device 7 includes an arithmetic control unit 70, a memory unit 71 that stores information used for processing by the arithmetic control unit 70, an input unit 72 that is electrically connected to the arithmetic control unit 70 and inputs an electrical signal as input information from an external electrical device to the arithmetic control unit 70, and an output unit 73 that is electrically connected to the arithmetic control unit 70 and outputs an instruction signal (electrical signal) as output information from the arithmetic control unit 70 to the external electrical device.

[0083] The arithmetic and control unit 70 is a CPU (MPU) and includes an arithmetic unit 70a and a control unit 70b. In the control device 7 according to this embodiment, the storage unit 71 includes a first storage unit 71a that temporarily or short-term stores information used in processing by the arithmetic and control unit 70 (arithmetic unit 70a and control unit 70b), and a second storage unit 71b that long-term stores information used in processing by the arithmetic and control unit 70 (arithmetic unit 70a and control unit 70b). The first storage unit 71a is a so-called memory, and the second storage unit 71b is a storage device such as a hard disk or SSD (Solid State Drive).

[0084] The input unit 72 and the output unit 73 are so-called interfaces. An electrical device that outputs an electrical signal as information is connected to the input unit 72. On the other hand, an electrical device that inputs an electrical signal as information is connected to the output unit 73.

[0085] Specifically, the input unit 72 includes a first voltage sensor SV1, a first current sensor SA1, a second voltage sensor SV2, a second current sensor SA2, a position detection sensor S, a receiving unit 8b, a GPS device 8, 0, etc. are connected to the output unit 73. On the other hand, the output unit 73 is connected to the transmitter 8a, the traveling electric motor 3, the device electric motor 6 (strictly speaking, the circuit breaker on the power line connected to these), etc. In this embodiment, the display device 47 is a touch panel type, and is therefore connected to the input unit 72 and the output unit 73 to send and receive information (signals) to and from the control device 7 (arithmetic control unit 70).

[0086] In this embodiment, the control device 7 controls the supply of power from the second battery 5B to the traveling electric motor 3 to be given priority over the supply of power from the first battery 5A to the traveling electric motor 3. Also, in this embodiment, the control device 7 controls the supply of power from the second battery 5B to the device electric motor 6 to be given priority over the supply of power from the first battery 5A to the device electric motor 6. In other words, the control device 7 supplies power from the second battery 5B to the traveling electric motor 3 and the device electric motor 6 so as to reduce (conserve) consumption of the stored power in the first battery 5A. Furthermore, when the charge level of the first battery 5A is less than fully charged, the control device 7 controls the first battery 5A to be charged with power supplied from the second battery 5B.

[0087] In this embodiment, the transmitter 8a and receiver 8b are integrated. That is, the work vehicle 1 is equipped with a transceiver 8 in which the transmitter 8a and receiver 8b are integrated (see FIG. 1). The transceiver 8 is connected to an antenna At (see FIG. 1) installed outside (in this embodiment, on the roof of the protection mechanism 45), and transmits and receives signals to and from a base station via the antenna At.

[0088] Various communication methods can be used for the transceiver 8 (transmitter 8a and receiver 8b). The transceiver 8 (transmitter 8a and receiver 8b) utilizes a wireless communication network as the communication network N1 for communicating with a base station. That is, because the work vehicle 1 operates while moving within a work site away from the base station, a transceiver terminal capable of communicating with the base station of the wireless communication network N1 is used as the communication network. If the work site environment requires long-distance communication with the base station, a transceiver terminal that transmits and receives signals to and from the base station of the public wireless communication network NT1 is used for the transceiver 8. On the other hand, if a private base station such as a Wi-Fi base station can be installed in a location close to the work site, a transceiver terminal that can transmit and receive signals to and from the base station of the public wireless communication network NT1 or the private base station is used for the transceiver 8. However, the information (signal) transmitted and received by the transceiver 8 is transmitted from the base station where it is directly received via the wired or wireless public wireless communication network NT1 to the destination (in this embodiment, a server 10 of the battery management system MS of the work vehicle 1, which will be described later).

[0089] In this embodiment, transmission and reception by the transceiver 8 (transmitter 8a, receiver 8b) is performed by the control device 7. Accordingly, the transceiver 8 (transmitter 8a, receiver 8b) is connected to the control device 7.

[0090] The control device 7 wirelessly transmits from the transceiver 8 (transmitter 8a) current status information including at least information regarding the remaining charge of the drive batteries 5 (first battery 5A, second battery 5B). In this embodiment, the control device 7 (transmitter 8a) transmits, as current status information, information regarding the remaining charge of the drive batteries 5 (first battery 5A, second battery 5B), as well as location information of the work site where the work vehicle 1 is performing work. Furthermore, the control device 7 (transmitter 8a) transmits, as current status information, the remaining charge of the drive batteries 5 (first battery 5A, second battery 5B) and the work area that can be worked with that remaining charge, or the work time that can be worked with the remaining charge of the drive batteries 5 (first battery 5A, second battery 5B). Furthermore, the control device 7 (transmitter 8a) transmits, as current status information, the traveling distance from the work site to the battery storage facility SY or the transport vehicle 11. That is, the control device 7 calculates the distance (travel distance) from the current position acquired by the GPS device 80 to the pre-registered battery storage facility SY or the transport vehicle 11, and transmits the calculated result (travel distance) as current status information. The destination (address) of the information (current status information) wirelessly transmitted by the is a server 10, which will be described later.

[0091] 12, when the work vehicle 1 is being driven (at least when work is being performed using the work implement E), the control device 7 performs an information transmission process for transmitting current status information to the server 10. In this information transmission process, the control device 7 acquires the voltage and current values ​​of the first battery 5A from the first voltage sensor SV1 and the first current sensor SA1, and acquires the voltage and current values ​​of the second battery 5B from the second voltage sensor SV2 and the second current sensor SA2 (S1).

[0092] The control device 7 then calculates the current amount of stored power of the first battery 5A from the acquired voltage and current values ​​of the first battery 5A, and calculates the current amount of stored power of the second battery 5B from the acquired voltage and current values ​​of the second battery 5B (S2).In addition, the control device 7 sums the calculated current amount of stored power of the first battery 5A and the calculated current amount of stored power of the second battery 5B to calculate the amount of stored power of the entire drive battery 5 (S3).

[0093] The control device 7 calculates the workable time or workable area with the calculated current amount of stored power (S4). In this embodiment, the control device 7 displays the calculated workable time and workable area on the display device 47. The workable time can be calculated by dividing the current amount of stored power by the rated power consumption of the work device E (for example, power consumption at rated output). The workable area can be calculated by dividing the current amount of stored power by the performance of the work device E (power required to perform work per unit area).

[0094] Furthermore, the control device 7 calculates the distance (travel distance) from the current position acquired by the GPS device 80 to the battery storage facility SY or the transport vehicle 11 registered in advance (S5).

[0095] The control device 7 then causes the transmitting unit 8a to transmit these calculation results as current status information of the work vehicle 1 working at the work site (S6), and repeats the above processing (S1 to S6) until the work at the work device E is completed (YES in S7) (NO in S7, END).

[0096] The work vehicle 1 of this embodiment is as described above. Assuming that the work vehicle 1 is an electric work vehicle, replacement of the battery (second battery 5B) is managed by the battery management system MS of the electric work vehicle 1, as shown in FIG. 11.

[0097] The battery management system MS of the work vehicle 1 manages whether or not replacement of the second battery 5B is necessary and arrangements for replacement based on the current charge capacity of the batteries (first battery 5A, second battery 5B).

[0098] Specifically, the battery management system MS of the work vehicle 1 is a work vehicle 1 that performs predetermined work within a work site using power supplied from a battery 5 (second battery 5B), and includes: a work vehicle 1 having a transmitter 8a that wirelessly transmits current status information including at least information regarding the remaining battery charge; and a server 10 having a receiver 10a that receives the current status information wirelessly transmitted from the transmitter 8a via a communication network (wireless communication network or wireless-wired communication network) NT1.

[0099] As described above, the work vehicle 1 transmits the current status information from the transmitter 8a to the server 10 in response to instructions from the control device 7.

[0100] Based on the current status information received by the receiving unit 10a, the server 10 requests the battery storage facility SY that has a charged replacement battery 5B that can be replaced with the second battery 5B or the transport vehicle 11 that transports the replacement battery 5B to transport the replacement battery 5B to the work site. That is, the server 10 performs a request process to request the delivery and replacement of the second battery 5B, which is a replacement battery. Accordingly, the server 10 has, in addition to the receiving unit 8b, a transmitting unit 10b that transmits information related to the request for delivery of the replacement battery 5B to the workshop. In this embodiment, the transmitting unit 10b transmits (sends) information to a communication network (wireless communication network or wired / wireless communication network) NT2. Here, the communication network NT2 is a wired or wireless public communication line.

[0101] The server 10 includes an arrival time calculation unit 100 that calculates the time that the replacement battery (second battery) 5B should arrive at the workshop based on the current status information (information on the remaining battery charge, location information) received by the receiving unit 8b, and a transportation request unit 101 that requests the battery storage facility SY or the transportation vehicle 11 to transport the replacement battery 5B to the workshop based on the calculation result of the arrival time calculation unit 100.

[0102] In the request processing, the transportation request unit 101 requests transportation to the work site of a charged replacement battery (second battery) 5B that can be replaced with the second battery 5B mounted on the work vehicle 1. That is, the transportation request unit 101 requests the battery storage facility SY or the transportation vehicle 11 to transport to the work site via the wired or wireless communication network NT2.

[0103] In this embodiment, the server 10 includes a server memory unit 102 that stores pre-registered request destinations (battery storage facility SY or transport vehicle 11) that are requested to transport a charged replacement battery (second battery) 5B to a work site, and the transport request unit 101 requests the request destination pre-registered (stored) in the server memory unit 102 to transport the battery to the work site via a wired or wireless communication network NT2.

[0104] Furthermore, the transportation request unit 101 transmits the location information of the work site to the battery storage facility SY or the transportation vehicle 11 in the request process.

[0105] As described above, the current status information includes the remaining battery capacity, the work area that can be worked with that remaining capacity, or the work time that can be worked with the remaining battery capacity. Accordingly, the arrival time calculation unit 100 calculates the time that the replacement battery 5B should arrive at the work site based on the remaining battery capacity and the work area that can be worked with that remaining capacity, or the work time that can be worked with the remaining battery capacity, included in the received current status information. The transportation request unit 101 requests the battery storage facility SY or the transportation vehicle 11 to transport the replacement battery 5B to the work site so that the replacement battery 5B arrives at the work site before the arrival time calculated by the arrival time calculation unit 100.

[0106] Furthermore, the current status information includes the travel distance from the workshop to the battery storage facility SY or the transport vehicle 11. Accordingly, the arrival time calculation unit 100 calculates the travel time required for transportation based on the travel distance included in the received current status information, and calculates the departure time from the battery storage facility SY or the departure time of the transport vehicle 11 based on the travel time so that the arrival of the replacement battery 5B at the workshop will be earlier than the calculation result of the arrival time calculation unit 100. The transportation request unit 101 notifies the battery storage facility SY or the transport vehicle 11 of the departure time in addition to requesting the battery storage facility SY or the transport vehicle 11 to transport the replacement battery 5B to the workshop.

[0107] More specifically, as shown in FIG. 13, the server 10 (arrival time calculation unit 100) acquires the current situation (S10), and calculates the time (required arrival time) by which the replacement battery (second battery) 5B should arrive at the work site based on the current situation (S11). That is, the server 10 (arrival time calculation unit 100) calculates the time until the amount of stored electricity in the drive battery 5 of the work vehicle 1 reaches 0 (zero) as the required arrival time (S11). Note that the required arrival time may be calculated as a time of day, but it may also be calculated as the elapsed time, which is the difference between the current time and the time the vehicle should arrive at the work site. In this embodiment, the server 10 calculates the required arrival time as a time. Calculate as follows.

[0108] The server 10 (arrival time calculation unit 100) also calculates the time required for travel (transportation) (required travel time) based on the travel distance included in the current status information (S12). At this time, the server 10 (arrival time calculation unit 100) calculates the required travel time by dividing the travel distance by the standard speed (average speed) of the transport vehicle 11 when traveling (S11). The server 10 (arrival time calculation unit 100) then calculates the time (departure time) at which the transport vehicle 11 loaded with the replacement battery (second battery) 5B should depart (S13). In other words, the server 10 calculates the departure time of the transport vehicle 11 so that the replacement battery 5B can arrive at the work site before the drive battery 5 runs out of charge (S13).

[0109] Note that, because the second battery 5B of the work vehicle 1 needs to be replaced with the replacement battery (charged second battery) 5b while the work vehicle 1 is in a state where it can move (before the amount of electricity stored in the drive battery 5 reaches 0 (zero)), it is assumed that the final time (time) of the required travel time, starting from the current time, will not exceed the required arrival time (time). Furthermore, the departure location of the transport vehicle 11 (the location value of the battery storage facility SY or the transport vehicle 11) is a predetermined location, and information about this location is detailed information about the battery storage facility SY or the transport vehicle 11 extracted from the battery storage facility SY or the transport vehicle 11 stored in the server storage unit 102 based on the location information included in the current status information. This detailed information includes geographical location information as well as an address (IP address or email address) for sending information.

[0110] The server 10 (transportation request unit 101) then transmits the above calculation results (departure time, required travel time, required arrival time) as request information to the battery storage facility SY or the transport vehicle 11 (S14). In addition, the server 10 also transmits the current location information of the work site (work vehicle) contained in the current status information (S14). In this embodiment, the request processing by the server 10 is repeated (S10 to S15) while the current status information is transmitted from the work vehicle 1 that is working and the server 10 is receiving the current status information (S15). When no current status information is received (NO in S15), it is assumed that the work vehicle 1 has finished its work, and the request processing by the server 10 also ends (END).

[0111] As described above, the ever-changing situation is transmitted to the battery storage facility SY or the transport vehicle 11, and the situation is reported to the worker who transports and replaces the replacement battery (second battery) 5B. Accordingly, the worker who transports the replacement battery (second battery) 5B transports the replacement battery (second battery) 5B based on the report.

[0112] In this embodiment, the delivery vehicle 11 has a monitor 110 that displays a map (see FIG. 11). The monitor 110 displays a travel route to a work site based on the location information of the work site from the server 10. In other words, the monitor 110 of the delivery vehicle 11 is a monitor of a navigation system that displays a map and a travel route, and displays the travel route on a map based on the received (accepted) location information.

[0113] These notifications allow the worker at the battery storage facility SY or the worker (driver) of the transport vehicle 11 to understand the conditions (departure time, time required for driving (traveling), etc.) under which the replacement battery 5B (replacement second battery 5B) can be delivered to the work site before the stored power of the drive battery 5 (first battery 5A and second battery 5B) of the work vehicle 1 working at the work site runs out, thereby preventing delays in the delivery of the second battery 5B and enabling the second battery 5B to be delivered before the work vehicle 1 becomes unable to operate.

[0114] The driver of the transport vehicle 11 drives the transport vehicle 11 according to the travel route displayed on the monitor 110, and transports the charged second battery 5B to the designated work site. This allows the driver transporting the second battery 5B to operate (transport) as scheduled without getting lost. Note that, upon receiving the supply of the second battery 5B, the transport vehicle 11 may automatically travel to the workshop using known automatic travel (unmanned travel) technology based on the location information of the workshop from the server 10.

[0115] As described above, when the replacement battery (replacement second battery) 5B arrives at the work site, the worker quickly removes the second battery 5B supported by the battery support part 9 and supports the charged second battery 5B on the battery support part 9.

[0116] Because the second battery 5B is a heavy item, the transport vehicle 11 that transports the replacement battery (second battery for replacement) 5B is either a cargo truck equipped with a crane device 113 having a loading platform for loading the second battery 5B, as shown in FIG. 14, or a dedicated vehicle equipped with an exchange device 13 that exchanges the battery of the work vehicle 1 with the replacement battery 5B, as shown in FIG. 15. In this embodiment, the replacement battery (second battery 5B) is transported by the dedicated vehicle shown in FIG. 15. The transport vehicle 11 as a dedicated vehicle is equipped with a conveyor device 112 for transporting (moving) the second battery 5B, and a crane device 113, as the exchange device 13.

[0117] The conveyor device 112 is a rail conveyor. The conveyor device 112 is a so-called roller conveyor, which includes a rail 112a extending in one direction and a plurality of rollers 112b arranged at intervals in the direction in which the rail 112a extends, the plurality of rollers 112b being rotatable around an axis extending in a direction perpendicular to the direction in which the rail 112a extends. The conveyor device 112 is attached so as to be slidable in the longitudinal direction of the rail 112a, and is switchable between a first state in which the rail 112a is housed within the loading platform of the transport vehicle 11, and a second state in which the rail 112a extends outward from the loading platform of the transport vehicle 11. In this embodiment, the conveyor device 112 extends rearward from the loading platform in the second state.

[0118] More specifically, the transporter vehicle 11 includes a guide rail 115 that extends in the front-to-rear direction of the transporter vehicle 11 and is attached to the loading platform, and a slider 116 that is movable in the front-to-rear direction along the guide rail 115 and is attached to the conveyor device 112 (rail 112a). With this, by moving the second battery 5B placed on the conveyor device 112 (rollers 112b...) rearward with the conveyor device 112 in the second state, the second battery 5B can be positioned rearward of the loading platform. In other words, because there is a limit to how close the work vehicle 1 can be to the transporter vehicle 11, even if the work vehicle 1 is parked at a moderate distance, by placing the conveyor device 112 in the second state, the replacement second battery 5B can be positioned closer to the work vehicle 1 (battery support portion 9).

[0119] In this embodiment, a position detection sensor S is attached to the tip of the arm 113a of the crane device 113, and by communication between the position detection sensor S of the crane device 113 and the position detection sensor S of the work vehicle 1, the tip of the arm 113a of the crane device 113 is automatically controlled to be positioned directly above the battery support part 9.

[0120] The second battery 5B has a suspending ring 54 on the top 511, and the hook 113c attached to the tip of the crane wire 113b of the crane is engaged with the suspending ring 54, and the second battery 5B is hoisted up by winding up the crane wire 113b. First, the second battery 5B supported on the battery support part 9 of the work vehicle 1 is removed. That is, the fall prevention fittings 93 are removed, and then the second battery 5B is hoisted up from the battery support part 9. As described above, the tip of the arm 113a of the crane device 113 is automatically aligned and positioned directly above the battery support part 9, and therefore the second battery 5B is lifted directly up by winding up the crane wire 113b. At this time, the positive electrode connection terminal The positive external terminal 53a and the negative external terminal 53b are separated from the terminal 92a and the negative external terminal 92b, and the electrical connection is also released. Then, the second battery 5B is placed on the conveyor device 112 that extends to the rear side of the loading platform.

[0121] Then, the hook 113c is engaged with the suspending loop 54 of the replacement battery (charged second replacement battery) 5B placed on the conveyor 112, and the crane wire 113b is wound up to lift the second battery 5B from the conveyor 112. Even at this time, communication between the position detection sensor S of the crane 113 and the position detection sensor S of the work vehicle 1 automatically controls the tip of the arm 113a of the crane 113 to be positioned directly above the battery support section 9. Therefore, when the crane wire 113b is unwound and the second battery 5B is lowered with the tip of the arm 113a positioned directly above the battery support section 9, the second battery 5B is placed in the appropriate position and arranged on the base 910. Even if the swinging of the crane wire 113b causes the second battery 5B to swing (move) in a direction perpendicular to the up-down direction, the second battery 5B is guided by the inclined surface 914 and placed in the appropriate position. Furthermore, as the replacement battery (second battery) 5B is lowered, the positive electrode connecting terminal 92a and the negative electrode connecting terminal 92b are fitted into the positive electrode external terminal 53a and the negative electrode external terminal 53b, respectively, and are electrically connected. In this embodiment, two second batteries 5B are placed on the battery support part 9, and therefore the remaining second battery 5B is also replaced using the above-described process.

[0122] As described above, by setting the conveyor device 112 to the second state, the second battery 5B is kept close to the battery support portion 9, thereby reducing the amount of movement of the second battery 5B by the crane device 113, thereby improving the efficiency of the replacement work.

[0123] Furthermore, if the transport vehicle 11 cannot approach the work vehicle 1 due to the influence of the surrounding environment of the work site, etc., it may be possible to utilize another work vehicle 1a (for example, a work vehicle 1a that is no longer primarily used for work at the work site) as shown in FIG. 16. Specifically, the work implement E that is connected to the coupling device 41 of the other work vehicle 1 may be a fork F on which the second battery 5B can be placed, the work implement including a lifting device 114 including the fork F that can be raised and lowered, and a crane device 113 that hoists the second battery 5B on the fork F. In this way, by using a work vehicle 1a that was previously active at the work site, it is possible to transport the second battery 5B close to the electric work vehicle 1 that is currently working. Furthermore, because the fork F can be raised and lowered, the height of the replacement battery (second battery 5B) and the height of the second battery 5B supported by the battery support section 9 can be matched, making it easier to suspend the second battery 5B with the crane device 113 without moving the second battery 5B significantly.

[0124] The above-described embodiment has been described above, and the present invention (preferable embodiments thereof) provides a work vehicle 1 described in the following items (items 1-1 to 1-14). In addition, the above-described embodiment also provides a battery management system MS for the electric work vehicle 1 described in the following items (items 2-1 to 2-11).

[0125] (Item 1-1) a vehicle body 4 supported by the traveling device 2 so as to be capable of traveling, the vehicle body 4 having coupling devices 40, 41 to which a working device E for performing a predetermined task can be coupled while being positioned on either the front or rear side of the vehicle body 4 in the fore-and-aft direction; and a drive battery 5 supported directly or indirectly on the vehicle body 4 and capable of supplying power to the electric traveling motor 3, the drive battery 5 including a first battery 5A positioned on the vehicle body 4, and a second battery 5B positioned on the other side of the vehicle body 4 in the fore-and-aft direction from the working device E, the second battery 5A being positioned on either the front side or the rear side.

[0126] According to the work vehicle 1 of item 1-1, since the second battery 5B is provided in addition to the first battery 5A, the drive battery 5 has a large overall capacity. Furthermore, since the second battery 5B is heavy, it functions as a balance weight when placed on the opposite side of the work implement E. Therefore, the work vehicle 1 of item 1-1 can ensure driving stability during work while ensuring sufficient battery capacity.

[0127] (Item 1-2) The work vehicle (1) according to item (1-1) includes an electric motor (6) for driving the work device (E), and the drive battery (5) is configured to be able to supply power to the electric motor (6) for driving the work device (E).

[0128] According to the work vehicle 1 of item 1-2, not only the electric motor 3 for driving but also the electric motor 6 for the equipment is provided, and these are driven by the power supply from the drive battery 5, so that problems such as exhaust gas are eliminated.

[0129] (Item 1-3) The work vehicle 1 described in item 1-1 or 1-2, wherein the traveling device 2 includes front wheels 2F and rear wheels 2R arranged at a distance in the fore-and-aft direction, and the first battery 5A is arranged between the front wheels 2F and the rear wheels 2R.

[0130] According to the work vehicle 1 of item 1-3, the first battery 5A, which is a heavy load, is disposed between the front wheels 2F and the rear wheels 2R, so that the load of the first battery 5A is distributed and applied to the front wheels 2F and the rear wheels 2R, thereby improving driving stability.

[0131] (Items 1-4) The work vehicle 1 described in any one of items 1-1 to 1-3 includes a battery support part 9 that can support the second battery 5B, the battery support part 9 being connected to the vehicle body 4 and positioned on the front side or the rear side.

[0132] According to the work vehicle 1 of items 1-4, the second battery 5B is stably supported (mounted) by the battery support portion 9.

[0133] (Items 1-5) The work vehicle 1 according to item 1-4, wherein the battery support portion 9 is configured to be able to support two or more second batteries 5B.

[0134] According to the work vehicle 1 of items 1-5, the size (weight) of each of the second batteries 5B arranged on the battery support portion 9 can be reduced, improving the handling characteristics of the second batteries 5B.

[0135] (Items 1-6) The work vehicle 1 described in item 1-4 or 1-5, wherein the body 4 has a body frame 42 extending in the fore-and-aft direction and supporting the first battery 5A, the coupling devices 40, 41 are attached to the front and rear ends of the body frame 42, respectively, and the battery support part 9 is detachably coupled to the coupling device 40, 41 that is located on the opposite side in the fore-and-aft direction from the coupling device 40, 41 to which the work device E is coupled.

[0136] According to the work vehicle 1 of items 1-6, since the battery support part 9 is detachable from the coupling devices 40, 41, the battery support part 9 can be attached to the opposite side of the work device E depending on the arrangement of the work device E. As a result, the second battery 5B can be disposed on the opposite side of the working device E in accordance with the position of the working device E, and the second battery 5B can function as a balance weight.

[0137] (Items 1-7) The work vehicle 1 according to item 1-5 or item 1-6 which cites item 1-5, wherein the battery support portion 9 is configured to be able to support two or more second batteries 5B arranged in the width direction of the vehicle body 4.

[0138] According to the work vehicle 1 of items 1-7, the weight balance (balance in the roll direction) of the entire work vehicle 1 can be achieved in the vehicle width direction (the lateral direction perpendicular to the front-to-rear direction).

[0139] (Items 1-8) The work vehicle 1 described in items 1-7, wherein the working device E is connected to the coupling devices 40, 41 while being biased in the width direction relative to the vehicle body 4, and the battery support portion 9 is configured to be able to support the second battery 5B on the side opposite to the bias direction of the working device E relative to the vehicle body 4.

[0140] According to the work vehicle 1 described in items 1-8, the arrangement (configuration) of the work implement E can prevent the weight balance (balance in the roll direction) from being lost.

[0141] (Items 1-9) The work vehicle 1 according to any one of items 1-1 to 8, wherein the second battery 5B is replaceable with another charged second battery 5B.

[0142] According to the work vehicle 1 of items 1-9, there is no need to charge the second battery 5B during work, and work can be continued simply by replacing it with another second battery 5B.

[0143] (Items 1-10) The work vehicle 1 is described in item 1-6, or any one of items 1-7 to 1-9 which directly or indirectly cite item 1-6, in which the body 4 has a hood 43 which covers the equipment on the body frame 42 from above and from the sides, and the first battery 5A is disposed within the hood 43.

[0144] According to the work vehicle 1 of items 1-10, the first battery 5A is not affected by wind and rain.

[0145] (Item 1-11) The work vehicle 1 according to any one of items 1-1 to 1-10, wherein the total weight of the second batteries 5B is set so that the traveling device 2 comes into contact with the ground in a travellable state.

[0146] According to the work device E of item 1-11, the gripping force of the traveling device 2 is increased, making it easier to work on rough roads or in environments with poor ground conditions.

[0147] (Items 1-12) The work vehicle 1 described in any one of items 1-1 to 1-11 includes a control device 7 that controls the power supply to the drive battery 5, and the control device 7 controls the power supply from the second battery 5B to the electric motor 3 for traveling to be given priority over the power supply from the first battery 5A to the electric motor 3 for traveling.

[0148] According to item 1-12 of the work vehicle 1, power is supplied from the second battery 5B to be replaced. By giving priority to power supply from the first battery 5A, it is possible to reduce power consumption from the first battery 5A. Furthermore, even if the amount of stored power in the second battery 5B decreases or runs out, power can be supplied from the first battery 5A until the second battery 5B is replaced with a charged one, so work can be continued without interruption.

[0149] (Items 1-13) The work vehicle 1 is provided with a control device 7 that controls the power supply to the drive battery 5, and the control device 7 controls the power supply from the second battery 5B to the device electric motor 6 to be given priority over the power supply from the first battery 5A to the device electric motor 6. The work vehicle 1 is described in item 1-2 or any one of items 1-3 to 1-12 that directly or indirectly cites item 1-2.

[0150] According to the work vehicle 1 of item 1-13, power consumption by the first battery 5A can be reduced by giving priority to power supply from the second battery 5B to be replaced over power supply from the first battery 5A. Furthermore, even if the amount of stored power in the second battery 5B decreases or runs out, power can be supplied from the first battery 5A until the second battery 5B is replaced with a charged one, so work can continue without interruption.

[0151] (Items 1-14) The work vehicle 1 described in item 1-12 or 1-13, wherein the control device 7 controls the first battery 5A to be charged with power supplied from the second battery 5B when the charge amount of the first battery 5A is less than fully charged.

[0152] According to the work vehicle 1 of item 1-14, the first battery 5A can be kept constantly fully charged, and when the amount of stored power in the second battery 5B decreases, work can be continued by using the power supply from the first battery 5A.

[0153] (Item 2-1) The electric work vehicle (work vehicle) 1 is an electric work vehicle (work vehicle) 1 that performs specified tasks within a work site using power supplied from a battery (driving battery) 5, and is equipped with: an electric work vehicle 1 having a transmitter 8a that wirelessly transmits current status information including at least information regarding the remaining charge of the battery (driving battery) 5; and a server 10 having a receiver 8b that receives the current status information wirelessly transmitted from the transmitter 8a via a communication network NT1, and the server 10 makes a request to a battery storage facility SY that holds a charged replacement battery (second battery) 5B that can be replaced with the battery (second battery of the driving battery 5) 5B, or to a transport vehicle 11 that transports the replacement battery (second battery) 5B, to transport the replacement battery (second battery) 5B to the work site, based on the current status information received by the receiver 8b.

[0154] According to the battery management system MS of the electric work vehicle 1 of item 2-1, based on current status information including at least information regarding the remaining charge of the battery (driving battery) 5, a request is made to a battery storage facility SY that holds a charged replacement battery (second battery) 5B that can be replaced with the battery (second battery of the driving battery 5) 5B, or to a transport vehicle 11 that transports the replacement battery 5B, to transport the replacement battery (second battery) 5B to the work site, so that the battery (second battery) 5B arrives before it is consumed. This makes it possible to reduce waiting times, etc.

[0155] (Item 2-2) The server 10 includes an arrival time calculation unit 10 that calculates the time when the replacement battery (second battery) 5B should arrive at the work site based on the current status information received by the receiving unit 8b. 0, and a transportation request unit 101 that requests the battery storage facility SY or the transportation vehicle 11 to transport the replacement battery (second battery) 5B to the work site based on the calculation result of the arrival time calculation unit 100.

[0156] According to the battery management system MS for the electric work vehicle 1 in item 2-2, the expected arrival time is calculated from current status information from the work vehicle 1, and a battery (second battery) 5B is requested based on this, which is efficient in terms of operation.

[0157] (Item 2-3) The battery management system MS for an electric work vehicle 1 described in item 2-2, wherein the transportation request unit 101 requests the battery storage facility SY or the transportation vehicle 11 to transport to the work site via a wired or wireless communication network NT2.

[0158] According to the battery system of the electric work vehicle 1 in item 2-3, a transport request is made via the wired or wireless communication network NT2, so that the request is transmitted to the battery storage facility SY or transport vehicle 11 without delay.

[0159] (Item 2-4) The current status information includes location information of the work site where the electric work vehicle 1 performs work, and the transportation request unit 101 transmits the location information of the work site to the battery storage facility SY or the transportation vehicle 11 along with the transportation request. A battery management system MS for an electric work vehicle 1 described in item 2-2 or item 2-3.

[0160] According to the battery management system MS for the electric work vehicle 1 in item 2-4, the location information of the work site is also transmitted, so the battery (second battery) 5B can be transported smoothly.

[0161] (Item 2-5) The battery management system MS for the electric work vehicle 1 described in any one of items 2-2 to 2-4, wherein the electric work vehicle 1 has a non-removable first battery 5A and a replaceable second battery 5B as the batteries, and the transportation request unit 101 requests transportation to the work site of a charged replacement battery (second battery) 5B that is replaceable with the second battery 5B in the transportation request.

[0162] According to the battery management system MS for an electric work vehicle in item 2-5, only the specific battery (second battery) 5B is replaced, which reduces the chance of arranging errors during transportation and storage.

[0163] (Item 2-6) The current status information includes the remaining capacity of the battery (driving battery) 5 and the work area that can be worked with that remaining capacity, or the work time that can be worked with the remaining capacity of the battery (driving battery) 5, and the arrival time calculation unit 100 calculates the time that the replacement battery (second battery) 5B should arrive at the work site based on the remaining capacity of the battery (driving battery) 5 and the work area that can be worked with that remaining capacity, or the work time that can be worked with the remaining capacity of the battery (driving battery) 5, and the transportation request unit 101 requests the battery storage facility SY or the transportation vehicle 11 to transport the replacement battery 5B to the work site so that the replacement battery (second battery) 5B arrives at the work site before the calculation result of the arrival time calculation unit 100. A battery management system MS for an electric work vehicle 1 described in any one of items 2-2 to 2-5.

[0164] According to the battery management system MS of the electric work vehicle 1 in item 2-6, the replacement battery ( A request for transportation of replacement battery 5B to the work site is made so that replacement battery 5B arrives before the calculated result, thereby preventing replacement battery 5B from arriving late at the work site.

[0165] (Item 2-7) Item 2-6: A battery management system MS for an electric work vehicle 1 described in item 2-6, wherein the current status information includes a travel distance from the work site to the battery storage site SY or the transport vehicle 11, the arrival time calculation unit 100 calculates the travel time required for transport based on the travel distance, and calculates a departure time from the battery storage site SY or a departure time of the transport vehicle 11 based on the travel time so that the arrival of the replacement battery (second battery) 5B at the work site will be earlier than the calculation result of the arrival time calculation unit 100, and the transport request unit 101 notifies the battery storage site SY or the transport vehicle 11 of the departure time in addition to requesting the battery storage site SY or the transport vehicle 11 to transport the replacement battery (second battery) 5B to the work site.

[0166] According to the battery management system MS of the electric work vehicle 1 in item 2-7, the departure time required to complete the replacement (arrival) of the replacement battery (second battery) 5B is notified, so that the time limit for departure can be understood before taking action, thereby preventing delays to the replacement battery 5B.

[0167] (Item 2-8) The transport vehicle 11 has a monitor 110 that displays a map, and the monitor 110 displays a route to the work site based on location information of the work site from the server 10. A battery management system MS for an electric work vehicle 1 described in item 2-4, or any one of items 2-5 to 2-7 that cite item 2-4.

[0168] According to the battery management system MS for the electric work vehicle 1 in item 2-8, the travel route is displayed on the monitor 110, so delays in the arrival of the replacement battery 5B due to taking the wrong route or the like can be reduced.

[0169] (Item 2-9) The transport vehicle 11 automatically travels to the work site based on the location information of the work site from the server 10. A battery management system MS for an electric work vehicle 1 described in item 2-4 or any one of items 2-5 to 2-7 which cite item 2-4.

[0170] According to the battery management system MS for the electric work vehicle 1 in item 2-9, the transport vehicle 11 automatically drives to the work site based on the location information of the work site from the server 10, thereby reducing delays in the arrival of the replacement battery 5B due to human error.

[0171] (Item 2-10) The transport vehicle 11 is a battery management system MS for an electric work vehicle 1 described in any one of items 2-1 to 2-9, which is equipped with an exchange device 13 that exchanges the battery (second battery) 5B of the electric work vehicle 1 with the exchange battery (second battery) 5B.

[0172] The battery management system MS for the electric work vehicle of item 2-10 utilizes the transport vehicle 11 equipped with the replacement device 13, thereby reducing the work time and improving work efficiency when replacing the replacement battery (second battery) 5B.

[0173] (Item 2-11) The transport vehicle 11 and the electric work vehicle 1 are provided with a position detection sensor S and a battery management system MS for an electric work vehicle 1 as described in item 2-10, in which at least one of the transport vehicle 11 and the electric work vehicle 1 adjusts the position of the exchange device 13 to a position where the battery (second battery) 5B and the replacement battery (second battery) 5B can be exchanged based on detection by the position detection sensor S.

[0174] According to the battery management system MS of the electric work vehicle 1 in item 2-11, based on the detection results of the position detection sensor S, the replacement device 13 adjusts the position of the battery (second battery) 5B and the replacement battery (second battery) 5B to a position where they can be replaced, thereby eliminating the effort required for replacement work (alignment work) and improving work efficiency.

[0175] The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present invention.

[0176] In the work vehicle 1 of the above embodiment, the first coupling device 40 and the second coupling device 41 have different structures, but this is not limited to this. For example, the first coupling device 40 and the second coupling device 41 may have the same structure. Furthermore, the first coupling device 40 and the second coupling device 41 may have the same structure as in this embodiment, with the front and rear of the first coupling device 40 and the second coupling device 41 swapped (the first coupling device 40 is a three-point link, and the second coupling device 41 is a fixed type). In this case, the coupling portion 90 of the battery support part 9 is naturally configured to be connectable to the coupling devices 40, 41 to be connected. Therefore, if the first coupling device 40 and the second coupling device 41 have the same configuration, the coupling portion 90 of the battery support part 9 is configured to be connectable to both the first coupling device 40 and the second coupling device 41, so the battery support part 9 can be used for both the front and rear.

[0177] In the above embodiment, the description is based on the assumption that the replacement battery (second battery) 5B is transported (transported) by the transport vehicle 11. However, for example, as shown in FIG. 17, a charging device EC having a charging function (power generation unit 120) for the second battery 5B may be installed near the work site. In this case, transportation of the replacement battery (second battery) 5B is unnecessary. In this case, the charging device EC is equipped with a replacement device 13 including a conveyor device 112 and a crane device 113. The conveyor device 112 is slidable in the direction of extension of the rail 112a, which is perpendicular to the up-down direction, and a position detection sensor S is attached to the tip of the arm 113a of the crane device 113, thereby achieving the same functions and effects as the dedicated vehicle described above. In this case, however, since the second battery 5B placed on the conveyor device 112 is to be charged, the charging terminals 120a, 120b electrically connected to the power generation unit 120 and connected to the external terminals 53a, 53b of the second battery 5B are connected to the external terminals 53a, 53b of the second battery 5B placed at the charging position by approaching them from below, and then moving away downward to release the electrical connection. It goes without saying that the charging terminals 120a, 120b are shaped similarly to the connection terminals 92a, 92b of the battery support unit 9.

[0178] Furthermore, as shown in FIG. 18, another work vehicle 1b (for example, work vehicle 1b) having a PTO shaft PS that transmits the drive of a prime mover (for example, an internal combustion engine) to a work implement may be utilized. Specifically, in this type of work vehicle 1b, the PTO shaft PS can be coupled directly or indirectly to the work implement that is coupled to the coupling device 41. Accordingly, a power generator EC1 that can be coupled to the PTO shaft PS and that generates electricity by receiving the rotation (drive) of the PTO shaft PS may be coupled to the other work vehicle 1b via the coupling device 41. In this way, the power generator EC1 is electrically connected to the drive batteries 5 (first battery 5A and second battery 5B), and the other work vehicle 1b drives the power generator EC1 to generate electricity, thereby charging the drive batteries 5 (first battery 5A and second battery 5B) that have a low stored amount of electricity. In this case, the power generator EC1 is equipped with a regulator and configured to be able to apply a charge voltage in DC, thereby enabling rapid charging. Furthermore, a work vehicle (electric work If a connector C3 is attached to the power line L of the work vehicle 1, connecting the charging power line L2 from the power generator EC2, then simply connecting the charging power line L2 to the connector C2 will electrically connect the power generator EC1 and the drive battery 5 (first battery 5A and second battery 5B). Therefore, the work vehicle 1 can charge the second battery 5B without removing it. As described above, the control device 7 supplies power preferentially from the second battery 5B over the first battery 5A, and therefore the second battery 5B has less stored power than the first battery 5A (normally, the first battery 5A is fully charged and conserved), so charging of the second battery 5B is the main focus, enabling charging to take place in a short period of time.

[0179] In the above embodiment, the working device E is disposed at the rear of the vehicle body 4, and the second battery 5B is disposed at the front of the vehicle body 4, opposite the working device E. However, this is not limiting. For example, as shown in FIG. 19 , the working device E may be disposed at the front of the vehicle body 4, and the second battery 5B may be disposed at the rear of the vehicle body 4, opposite the working device E. That is, the battery support part 9 may be connected to the second coupling device 41 (a three-point link in the figure). In this case, the positive electrode connection terminal 92a and the negative electrode connection terminal 92b of the battery support part 9 are connected to the power line L on the vehicle body 4 side via the second connector C2. Needless to say, the coupling part 90 is configured to be connectable to the second coupling device 41 or the hitch device Ea attached to the second coupling device 41 (capable of being engaged with the three-point link) using a known coupling structure for the working device E.

[0180] In the above embodiment, the battery support section 9 of the work vehicle 1 is configured to be able to support two second batteries 5B, but this is not limiting. For example, the battery support section 9 may be configured to be able to support three or more second batteries 5B. In this case, it is preferable that the three or more second batteries 5B are arranged side by side in the horizontal direction. Furthermore, as shown in FIG. 20, the battery support section 9 may be configured to be able to support a single second battery 5B. In this case, it is preferable to increase the size of the second battery 5B so that its power storage capacity is large. More specifically, it is preferable to increase the size of the battery case 51 and provide the second battery 5B with many battery cells 500... housed within the battery case 51. Furthermore, in this case, when increasing the size of the battery case 51, it is preferable that the second battery 5B (battery case 51) be formed horizontally elongated (with its long sides extending horizontally). Furthermore, in this case, since the second battery 5B is heavy, it is preferable that the hanging ring sections 54 be provided at multiple locations.

[0181] In the above embodiment, the lateral size (length) of the second battery 5B (battery case 51) when supported by the battery support part 9 is set to be equal to or less than the overall lateral width of the work vehicle 1, but the lateral size may be set to exceed the overall width of the work vehicle 1. In this case, a sensing device (for example, an optical sensor, such as an imaging device such as a camera, a LiDAR (Light Detection And Ranging) sensor, or a ToF (Time of Flight) camera) that senses the surroundings of the work vehicle 1 may be provided at both lateral ends of the battery support part 9. In other words, the battery support part 9 may serve both to support the second battery 5B and the sensing device. In this case, the second battery 5B supported by the battery support part 9 is disposed between the pair of sensing devices at both lateral ends. Naturally, even when the lateral size (length) when supported by the battery support part 9 is set to be equal to or less than the overall lateral width of the work vehicle 1, a sensing device or a support stay that supports the sensing device may be provided at both lateral ends of the battery support part 9.

[0182] In the above embodiment, when replacing the second battery 5B, the second battery 5B is lifted (raised) using the crane device 113. However, for example, the second battery 5B may be raised (jacked up) and lowered (jacked down) using a jack device. However, in order to move the second battery 5B in the front-rear direction while supporting the lower surface of the second battery 5B (the bottom 510 of the battery case 51), for example, the jack device may need to be moved. The battery support portion 9 may be provided with a slit that allows the jack device to move in the front-rear direction relative to the battery mounting portion 91 by providing the running wheels.

[0183] In the second battery 5B of the above embodiment, the positive external terminal 53a and the negative external terminal 53b have the recesses 530a, 530b, but this is not limiting. For example, the positive external terminal 53a and the negative external terminal 53b may have convex portions extending in the vertical direction instead of the recesses 530a, 530b. In this case, it goes without saying that in the battery support part 9, the positive connecting terminal 92a and the negative connecting terminal 92b have concave portions into which the convex portions of the positive external terminal 53a and the negative external terminal 53b can be fitted, instead of the convex portions 920a, 920b. Furthermore, in the second battery 5B, both the positive external terminal 53a and the negative external terminal 53b have the concave portions 530a, 530b, but this is not limiting. For example, either the positive external terminal 53a or the negative external terminal 53b may have a concave portion, and the other may have a convex portion. In this case, in the battery support part 9, either the positive electrode connecting terminal 92a or the negative electrode connecting terminal 92b has a convex part that can fit into the concave part of either the positive electrode external terminal 53a or the negative electrode external terminal 53b, and the other of the positive electrode connecting terminal 92a or the negative electrode connecting terminal 92b has a concave part that can fit into the convex part of the other of the positive electrode external terminal 53a or the negative electrode external terminal 53b.

[0184] In the above embodiment, the connecting devices 40, 41 also serve as the support portion connecting devices 48a, 48, but this is not limiting. For example, the support portion connecting devices 48a, 48b may be dedicated devices for connecting the battery support portion 9. In other words, the support portion connecting devices 48, 48b may be separate and independent from the connecting devices 40, 41.

[0185] In the above embodiment, the coupling devices 40, 41 (first coupling device 40, second coupling device 41) are attached to both the front and rear ends of the body frame 42, and the support portion coupling devices 48a, 48b are attached to both the front and rear ends of the body frame 42, but this is not limiting. For example, the coupling devices 40, 41 (first coupling device 40, second coupling device 41) may be attached to only one of the front end or the rear end of the body frame 42, and the coupling devices 40, 41 (first coupling device 40, second coupling device 41) may be attached to only the other of the front end or the rear end of the body frame 42.

[0186] In the above embodiment, the coupling devices 40, 41 (first coupling device 40, second coupling device 41) are attached to the front and rear ends of the body frame 42, but the present invention is not limited to this. For example, the coupling devices 40, 41 may be attached to a middle position in the fore-and-aft direction of the body frame 42, on the assumption that the working device E is disposed at the front or rear of the body 4. Specifically, the coupling devices 40, 41 may be arms that extend from a middle position of the body frame 42 to either the front or rear, and have a tip to which the working device E (for example, a bucket for scooping soil) is connected. In this case, by attaching the working device E to the tip of the arm of the coupling device, the working device E is disposed at either the front or rear of the body 4. In this case, for example, by connecting the battery support part 9 to the support part connecting devices 48a, 48b attached to either the front or rear end of the vehicle body 4 and having the second battery 5b supported by the battery support part 9, the second battery 5B is positioned on the opposite side of the working device E in the fore-and-aft direction (either the front or rear of the vehicle body 4), and as a result, the same action and effect as in the above embodiment can be achieved.

[0187] In the above embodiment, the support portion coupling devices 48a, 48b are attached to the front and rear ends of the body frame 42, but this is not limiting. For example, the support portion coupling devices 48a, 48b may be attached to a middle position in the front-rear direction of the body frame 42, on the premise that the second battery 5B supported by the battery support portion 9 is located either at the front or rear of the body 4, on the opposite side of the working device E in the front-rear direction. In this case, the battery support portion 9 is attached to the battery mounting portion 91 (second battery 5B) at the front or rear of the body 4. The connecting portion 90 is configured so that it can be placed in either one of the positions. [Explanation of symbols]

[0188] 1: Work vehicle (electric work vehicle) 2: Running gear 2F: Front wheel 2R: Rear wheel 3: Electric motor for driving 4: Body 5: Drive battery 5A: 1st battery 5B: Second battery (replacement battery) 6: Electric motor for equipment 7: Control device 8a: Transmitter 8b: Receiving section 9: Battery support 10: Server 10a: Receiving section 11: Transport vehicle 40: Connecting device (first connecting device) 41: Connecting device (second connecting device) 42: Body frame 43: Bonnet 44: Driver's seat 100: Arrival time calculation section 101: Transportation Request Department 102: Server storage 110: Monitor 111: Exchange device MS: Battery Management System NT1: Communication network (public communication network, public wireless communication network) S: Position detection sensor SY: Battery storage

Claims

1. Running gear and an electric motor for driving the traveling device; a vehicle body supported by the traveling device so as to be capable of traveling, the vehicle body having a coupling device that can couple a work device that performs a predetermined work to the vehicle body while the work device is disposed on either the front side or the rear side in the longitudinal direction of the vehicle body; a drive battery that is supported directly or indirectly on the vehicle body and is capable of supplying power to the electric motor for running; The work vehicle includes a first battery arranged in the vehicle body, and a second battery arranged on the other of the front and rear sides, on the opposite side of the work implement with the vehicle body sandwiched between them in the fore-and-aft direction.

2. an electric motor for driving the working device; 2. The work vehicle according to claim 1, wherein the drive battery is configured to be able to supply power to the electric motor for the device.

3. the traveling device includes front wheels and rear wheels spaced apart in the front-rear direction, The work vehicle according to claim 1 , wherein the first battery is disposed between a front wheel and a rear wheel.

4. The work vehicle according to claim 1 , further comprising a battery support portion capable of supporting the second battery, the battery support portion being connected to the vehicle body and being disposed on the front side or the rear side.

5. The work vehicle according to claim 4 , wherein the battery support portion is configured to be able to support two or more second batteries.

6. the vehicle body includes a vehicle body frame extending in the front-rear direction and supporting the first battery, the coupling device is attached to each of the front end and the rear end of the body frame, The work vehicle according to claim 4 , wherein the battery support portion is detachably connected to the connecting device that is located on the opposite side in the front-to-rear direction from the connecting device to which the work implement is connected.

7. The work vehicle according to claim 5 , wherein the battery support portion is configured to be able to support two or more second batteries arranged in a width direction of the vehicle body.

8. the working device is connected to the connecting device while being biased in the width direction relative to the vehicle body, The work vehicle according to claim 7 , wherein the battery support section is configured to be able to support the second battery on the side opposite to the direction in which the work implement is biased relative to the vehicle body.

9. The work vehicle according to claim 1 , wherein the second battery is replaceable with another charged second battery.

10. the vehicle body has a hood that covers the equipment on the vehicle body frame from above and from the sides, The work vehicle according to claim 6 , wherein the first battery is disposed inside the hood.

11. The work vehicle according to claim 1 , wherein a total weight of the second battery is set so that the travel device contacts the ground in a travelable state.

12. a control device that controls power supply to the drive battery, 2. The work vehicle according to claim 1, wherein the control device controls the supply of power from the second battery to the electric motor for traveling to be given priority over the supply of power from the first battery to the electric motor for traveling.

13. a control device that controls power supply to the drive battery, 3. The work vehicle according to claim 2, wherein the control device controls the supply of power from the second battery to the electric motor for the device to take priority over the supply of power from the first battery to the electric motor for the device.

14. The work vehicle according to claim 12 or 13, wherein the control device controls the first battery to be charged with power supplied from the second battery when the first battery is less than fully charged.

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