Work vehicle

Abstract

Provided is a work vehicle that has excellent durability at mast mechanisms that connect a vehicle body and a travel structure.　A work vehicle (1) comprises a vehicle body (2) that can move in the vertical direction, a travel structure (3) that is provided to the side of the vehicle body (2), and a plurality of mast structures (7) that each have a travel-side mast member (71) that is a first member that is attached to the travel structure (3), a vehicle body–side mast member (72) that is a second member that is attached to the vehicle body (2) and can move in the vertical direction along the travel-side mast member (71) to raise / lower the vehicle body (2), and a restriction part (74) that restricts the movement of the vehicle body–side mast member (72) in a direction that intersects the vertical direction. The plurality of mast mechanisms (7) include a first mast mechanism (7A) and a second mast mechanism (7B) that are attached to the vehicle body (2) and the travel structure (3) such that the restriction directions of the respective restriction parts (74) are different.

Description

Work vehicles

[0001] The present invention relates to a work vehicle for performing work such as agricultural work.

[0002] In recent years, agricultural work using work vehicles has been shifting from a manual operation performed by a worker in the vehicle to a remote-controlled operation where the worker remotely controls the vehicle using a terminal device, or an autonomous operation where the vehicle is driven by GPS along a route set in the field, in which the work vehicle is driven unmanned.

[0003] Therefore, the vehicle configuration may change from a conventional tractor type with a driver's seat, as disclosed in Patent Document 1, to a configuration that is more convenient for carrying out the intended work, such as agricultural work, while also providing excellent protection and durability for each part.

[0004] Here, when considering a case where an unmanned work vehicle consisting of a vehicle body and left and right running structures with wheels etc. arranged on both the left and right sides of the vehicle body is used to perform agricultural work, for example, by placing the liftable vehicle body across a ridge and arranging the left and right running structures on both the left and right sides of the ridge, it is conceivable to connect the vehicle body and running structures with a mast mechanism such as that used in forklifts as described in Patent Document 1.

[0005] Japanese Patent Publication No. 2023-64964

[0006] When such mast mechanisms are used, for example, in a front-to-back or side-to-side arrangement to connect the left and right running structures of the vehicle body, by considering the layout in consideration of the direction in which stress is applied due to the structure, it is possible to provide a work vehicle equipped with a mast mechanism that is strong and highly durable.

[0007] A work vehicle according to one embodiment of the present invention comprises a vehicle body that can move in an up-and-down direction, a running structure provided on the side of the vehicle body, a first member attached to the running structure, a second member attached to the vehicle body that can raise and lower the vehicle body by moving in an up-and-down direction along the first member, and a plurality of mast mechanisms each having a regulating part that regulates movement of the second member in a direction intersecting the up-and-down direction, and the plurality of mast mechanisms include a first mast mechanism and a second mast mechanism attached to the running structure and the vehicle body so that the regulating directions of the regulating parts differ from each other.

[0008] The first mast mechanism may be attached to the running structure and the vehicle body so that the regulating portion regulates the movement of the second member in the forward / backward direction, and the second mast mechanism may be attached to the running structure and the vehicle body so that the regulating portion regulates the movement of the second member in the left / right direction.

[0009] The plurality of mast mechanisms including the first mast mechanism and the second mast mechanism may be arranged side by side in the front and rear directions on the left or right side of the vehicle body.

[0010] The plurality of mast mechanisms including the first mast mechanism and the second mast mechanism may be provided at the front, rear, and intermediate portions between the front and rear on the left or right side of the vehicle body.

[0011] The first mast mechanism may be provided at each of the front and rear sections, and the second mast mechanism may be provided at the intermediate section between the front and rear sections.

[0012] The plurality of mast mechanisms including the first mast mechanism and the second mast mechanism may be arranged side by side in the front-to-rear direction on each of the left and right sides of the vehicle body.

[0013] The plurality of mast mechanisms including the first mast mechanism and the second mast mechanism may be provided at the front, rear, and intermediate portions between the front and rear on each of the left and right sides of the vehicle body.

[0014] The first mast mechanism may be provided at each of the front and rear sections, and the second mast mechanism may be provided at the intermediate section between the front and rear sections.

[0015] Of the multiple mast mechanisms on the left side and the multiple mast mechanisms on the right side, the mast mechanism on the left side and the mast mechanism on the right side that are arranged at the same position in the fore-and-aft direction of the vehicle may be unified as either the first mast mechanism or the second mast mechanism.

[0016] The traveling structure may have an inner surface facing a side surface of the vehicle body, and the first member may be attached to the inner surface of the traveling structure.

[0017] According to the work vehicle of the present invention, the vehicle body and running structure are connected by a mast mechanism that has reliable rigidity against loads applied in all directions, making it possible to make the vehicle highly durable.

[0018] 1 is a perspective view of a work vehicle; FIG. 2 is a left side view of a work vehicle; FIG. 3 is a right side view of a work vehicle; FIG. 4 is a front view of a work vehicle; FIG. 5 is a rear view of a work vehicle; FIG. 6 is a plan view of a work vehicle; FIG. 7 is a perspective view showing a frame structure of a vehicle body and a traveling structure of a work vehicle; FIG. 8 is a block diagram showing a control system structure of a work vehicle; FIG. 9 is a plan view of a work vehicle with the vehicle body extended to the left and right; FIG. 10 is a perspective view of a work vehicle with the vehicle body raised; FIG. 11 is a left side view of a work vehicle with the vehicle body raised; FIG. 12 is a left side view of the vehicle body with the front main body case moved forward; FIG. 13 is a schematic view of a work vehicle showing switching of the front and rear positions of the front main body case with the vehicle body raised; FIG. 14 is a diagram showing the layout of a mast mechanism in a left side view of a work vehicle; FIG. 15 is a diagram showing the layout of a mast mechanism in a plan view of a work vehicle; FIG. 16 is a diagram showing the layout of a first mast mechanism in a front view of a work vehicle; FIG. 17 is a diagram showing the layout of a mast mechanism in a left side view of a work vehicle with the vehicle body raised; FIG. 18 is a diagram showing the layout of a first mast mechanism in a front view of a work vehicle with the vehicle body raised. FIG. 10 is a diagram showing the layout of the second mast mechanism as seen from the front of the work vehicle with the vehicle body raised.

[0019] A preferred embodiment of a work vehicle 1 according to the present invention will now be described with reference to the accompanying drawings.

[0020] In the following description, the direction indicated by the arrow X1 in FIG. 1 is referred to as the forward direction, the direction indicated by the arrow X2 is referred to as the backward direction, the direction indicated by the arrow Y1 is referred to as the left direction, the direction indicated by the arrow Y2 is referred to as the right direction, the direction indicated by the arrow Z1 is referred to as the upward direction, and the direction indicated by the arrow Z2 is referred to as the downward direction.

[0021] Examples of work performed by the work vehicle 1 include, but are not limited to, agricultural work, industrial (civil engineering, construction, etc.) work, and transportation work. In a preferred embodiment of the present invention, the work performed by the work vehicle 1 is agricultural work (farm work). Below, an example will be described in which the work performed by the work vehicle 1 is farm work. In this case, the work vehicle 1 is an agricultural work vehicle.

[0022] 1 to 6, the work vehicle 1 includes a vehicle body 2, a left traveling structure 3L disposed on the left side of the vehicle body 2, and a right traveling structure 3R disposed on the right side of the vehicle body 2. Hereinafter, each of the left traveling structure 3L and the right traveling structure 3R may be referred to as a traveling structure 3.

[0023] As shown in Figure 5 and other figures, the vehicle body 2 is provided at its rear end with a PTO shaft 5 for transmitting driving force to a work implement 200 (see Figures 2 and 3) connected to the work vehicle 1, and a coupling device 6 for coupling the work implement 200 to the work vehicle 1 can be attached to the rear end.

[0024] The structure of the connecting device 6 can be variously considered depending on the type of work device (implement) 200, but in this embodiment, it is a three-point link mechanism having a pair of left and right lower links 6a and one top link 6b.

[0025] The working device 200 is also connected to a portion other than the rear end of the body 2 of the work vehicle 1 (for example, the front end) and is capable of receiving driving force from the work vehicle 1.

[0026] The structure of each traveling structure 3 will be described with reference to Figures 1 to 7 etc. Each traveling structure 3 has a traveling frame 30 and a pair of wheel units 4. The pair of wheel units 4 consists of a front wheel unit 4F supported at the front of the traveling frame 30 and a rear wheel unit 4R supported at the rear of the traveling frame 30.

[0027] Each wheel unit 4 has one wheel 31 and a wheel drive case 32 that supports the wheel 31. The wheel 31 of the front wheel unit 4F is a front wheel 31F, and the wheel 31 of the rear wheel unit 4R is a rear wheel 31R.

[0028] As can be seen from the front view in Figure 4, the rear view in Figure 5, and the plan view in Figure 6, in the left-right direction, the position of the outer end of the running frame 30 and the position of the outer end of the wheels 31 (front wheel 31F and rear wheel 31R) are approximately aligned.

[0029] The front wheels 31F and the rear wheels 31R have the same or approximately the same diameter. However, the front wheels 31F and the rear wheels 31R may have different diameters. Furthermore, at least one of the front wheels 31F and the rear wheels 31R may be used as a drive wheel (drive sprocket) of the crawler-type traveling device.

[0030] Furthermore, the running frame 30 of the left running structure 3L is the left running frame 30L, the front wheel unit 4F supported at the front of the left running frame 30L is the left front wheel unit 4FL having a left front wheel 31FL, and the rear wheel unit 4R supported at the rear of the left running frame 30L is the left rear wheel unit 4RL that supports the left rear wheel 31RL.

[0031] On the other hand, the running frame 30 of the right running structure 3R is the right running frame 30R, the front wheel unit 4F supported at the front of the right running frame 30R is the right front wheel unit 4FR that supports the right front wheel 31FR, and the rear wheel unit 4R supported at the rear of the right running frame 30R is the right rear wheel unit 4RR that supports the right rear wheel 31RR.

[0032] The wheel drive case 32 of each wheel unit 4 has a motor housing section 32a, a transmission mechanism housing section 32b, and a rotating cylinder section 32c. The motor housing section 32a and the transmission mechanism housing section 32b are integrally molded at the top of the wheel drive case 32, and the rotating cylinder section 32c extends vertically downward from the transmission mechanism housing section 32b, which extends to the side of the motor housing section 32a. The rotating cylinder section 32c is connected to the transmission mechanism housing section 32b so as to be rotatable relative to it.

[0033] A travel motor 33 (see FIG. 8) is housed in the motor housing section 32a, and a vertical transmission shaft 34 having an axis extending in the up-down (vertical) direction is supported in the rotating cylinder section 32c so as to be rotatable about its axis. The central shafts (axles) 31a of the wheels 31 are inserted into and supported at the lower ends of the rotating cylinder section 32c. In other words, the axles 31a protrude outward on the left and right from the bottom of the rotating cylinder section 32c of the wheel drive case 32, and the wheels 31 provided around these axles 31a are disposed on the left and right outer sides of the rotating cylinder section 32c.

[0034] The transmission mechanism housing section 32b houses a transmission mechanism having a bevel gear, an endless belt, etc. that links the output shaft of the travel motor 33 and the upper part of the vertical transmission shaft 34. Furthermore, the lower part of the rotating cylinder section 32c houses a transmission mechanism having a bevel gear, etc. that links the lower part of the vertical transmission shaft 34 and the axle 31a of the wheel 31.

[0035] It should be noted that the traveling frame 30 may be described as supporting the axle 31 a because the traveling frame 30 supports the wheel drive case 32 that supports the axle 31 a of the wheel 31 .

[0036] With the above-described configuration, the output of the travel motor 33 is transmitted to the wheels 31 via the vertical transmission shaft 34 inside the wheel drive case 32, thereby driving the wheels 31. That is, the left front wheel 31FL, the right front wheel 31FR, the left rear wheel 31RL, and the right rear wheel 31RR are each a drive wheel driven by the output of its own travel motor 33.

[0037] As described above, the rotating cylinder portion 32c of each wheel drive case 32 extends in the vertical direction, and the vertical axis of the vertical transmission shaft 34 coincides with the axis of the rotating cylinder portion 32c. The wheel drive case 32 has an upper portion, which serves as the motor housing portion 32a and the transmission mechanism housing portion 32b, attached and fixed to the running frame 30, while the rotating cylinder portion 32c is rotatable about the vertical axis relative to the upper portion.

[0038] A pair of front and rear steering cylinders 35 are supported on the traveling frame 30. The steering cylinder 35 supported on the front part of the traveling frame 30 is a front steering cylinder 35F, and one end (cylinder bottom) of the front steering cylinder 35F is connected to the traveling frame 30, and the other end (piston rod head) of the front steering cylinder 35F is connected to the outer side of the rotating cylinder portion 32c of the wheel drive case 32 of the front wheel unit 4F.

[0039] The steering cylinder 35 supported on the rear of the running frame 30 is a rear steering cylinder 35R, one end (cylinder bottom) of the rear steering cylinder 35R is connected to the running frame 30, and the other end (piston rod head) of the rear steering cylinder 35R is connected to the outer part of the rotating tube portion 32c of the wheel drive case 32 of the rear wheel unit 4R.

[0040] The rotating cylinder portion 32c of each wheel drive case 32 pivotally supports the wheel 31 and rotates about its vertical axis due to the extension and contraction of the steering cylinder 35. That is, the wheel 31 is not only a driving wheel driven by the traveling motor 33 as described above, but also a steering wheel that can rotate relatively in the left-right direction with respect to the traveling frame 30, i.e., the angle in the left-right direction can be changed.

[0041] Each traveling motor 33 is an electric motor, and an inverter 38 for controlling its output is provided in the traveling structure 3. As shown in Fig. 8, the inverter 38 is controlled by the control device 15, which controls the output rotation speed and output rotation direction of the corresponding traveling motor 33.

[0042] Note that the block diagram of Figure 8 only shows the combination of the traction motor 33 and inverter 38 for one wheel unit 4, but the wheel unit 4 here represents each of the four wheel units 4FL, 4FR, 4RL, and 4RR, and the control device 15 controls the inverter 38 for each individual wheel unit 4, thereby individually controlling the rotation speed and direction of each wheel 31.

[0043] As shown in Figures 1 to 3, the running frame 30 of each running structure 3 supports the battery case 36 at an intermediate portion between the front portion that supports the wheel drive case 32 of the front wheel unit 4F and the rear portion that supports the wheel drive case 32 of the rear wheel unit 4R.

[0044] A battery (side battery) 37 that supplies power to the travel motors 33 of the front wheel unit 4F and the rear wheel unit 4R is housed inside the battery case 36. An inverter 38 for the front wheel unit 4F is supported on the travel frame 30 at the front side of the battery case 36, and an inverter 38 for the rear wheel unit 4R is supported on the rear side of the battery case 36. The location of the inverter 38 is not limited to the location shown in the figure, and it may be provided inside the battery case 36, for example.

[0045] The front wheel unit 4L and rear wheel unit 4R of each running structure 3 (left running structure 3L, right running structure 3R) each drive their respective running motors 33 with power supplied from a battery (center battery 50 and / or side battery 37) provided on the work vehicle 1.

[0046] The inverter 38 provided for each wheel unit 4 converts the direct current from the batteries 37, 50 into alternating current and applies the alternating current to the traction motor 33 of that wheel unit 4 at a set voltage and / or frequency.

[0047] As shown in Figure 8, the voltage and / or frequency setting values ​​of each inverter 38 are controlled by the control device 15, thereby controlling the output rotation speed and / or torque of the travel motor 33, and thereby controlling the rotation speed and / or torque of the wheel 31 of the wheel unit 4.

[0048] Each steering cylinder 35 is a hydraulic cylinder (hydraulic actuator) and is expanded and contracted by hydraulic oil discharged from a hydraulic pump 55 (described later) provided in the vehicle body 2 and supplied via a corresponding control valve.

[0049] As shown in Figure 8, the position of the corresponding control valve (spool) in the control valve unit 27 is controlled by the control device 15, thereby controlling the extension amount of the piston rod and steering the wheels 31 of the wheel unit 4.

[0050] As with the traction motor 33 and inverter 38 described above, the block diagram of Figure 8 shows only one steering cylinder 35, but this steering cylinder 35 means one provided for each wheel unit 4, and the control device 15 controls the control valve for the steering cylinder 35 for each individual wheel unit 4, thereby individually controlling the steering angle (left and right turning angle) of each wheel 31.

[0051] Each steering cylinder 35 may be configured as an air cylinder, a water cylinder, or the like other than a hydraulic cylinder. Furthermore, the actuator that steers the wheels 31 may be configured to rotate the rotating cylinder portion 32c by outputting a rotational force, such as an electric motor or a hydraulic motor, in addition to such a telescopic actuator.

[0052] The structure of the traveling frame 30 will now be described with reference to FIGS. 1 to 7.

[0053] That is, the work vehicle 1 includes a vehicle body 2, wheels 31 provided on the sides of the vehicle body 2, and a traveling frame 30 provided on the sides of the vehicle body 2 and supporting the wheels 31. The traveling frame 30 has an upper frame portion 30u arranged above the wheels 31, and has space above the upper frame portion 30u for arranging equipment.

[0054] In this embodiment, as described below, space for arranging equipment is provided above the front wheels 31F and rear wheels 31R, on the upper part of the upper frame portion 30u of each left and right running frame 30. However, space for arranging equipment may also be provided above at least one wheel 31 (e.g., one of the front wheels 31F and rear wheels 31R) on at least one running frame 30 (e.g., one of the left and right running frames 30L, 30R).

[0055] The wheels 31 include front wheels 31F and rear wheels 31R, and the upper frame portion 30u includes a front portion provided above the front wheels 31F and a rear portion provided above the rear wheels 31R, and has space for arranging equipment above the front portion and the rear portion.

[0056] In this embodiment, a flush, flat surface is formed from the front end to the rear end of the upper frame portion 30u of the running frame 30, including the front portion above the front wheels 31F and the rear portion above the rear wheels 31R, to provide a space for arranging equipment. That is, the upper frame portion 30u is provided so as to extend from above the front wheels 31F to above the rear wheels 31R, and the space for arranging equipment is provided in a range from above the front wheels 31F to above the rear wheels 31R. However, it is sufficient that at least a space for arranging equipment is provided in the front and rear portions of the upper frame portion 30u. For example, the front and rear portions may be separated to form a gap, or the surface may not be flat enough to be used as a space for arranging equipment.

[0057] The vehicle body 2 is movable in the vertical direction relative to the traveling frame 30, but does not have any portion that interferes with the space for arranging the equipment during the vertical movement relative to the traveling frame 30. As mentioned above, the space for arranging the equipment may be provided above one of the wheels 31, and in this case, the vehicle body 2 does not need to have any portion that interferes with the space for the equipment above the wheel 31.

[0058] The work vehicle 1 is provided with a lifting device for moving the vehicle body 2 up and down on the inner side in the left-right direction of the traveling frame 30, i.e., on the vehicle body 2 side.

[0059] This configuration also eliminates any portions that would interfere with the equipment installation space above the upper frame portion 30u of the traveling frame 30 while the vehicle body 2 is moving up and down. If the lifting device were located between the left and right ends of the traveling frame 30, i.e., within the left-to-right width, rather than on the left and right inner sides of the traveling frame 30, and were configured to expand and contract up and down, it would protrude above the traveling frame 30 when the vehicle body 2 was raised, and could interfere with equipment installed in the equipment installation space provided in the upper frame portion 30u. Note that even if the lifting device is provided on the left and right outer sides of the traveling frame 30, it is possible that no portions would interfere with the equipment installation space while the vehicle body 2 is moving up and down. However, by locating the lifting device on the left and right inner sides of the traveling frame 30, connection to the vehicle body 2 is easy and compactness in the left-to-right width direction of the work vehicle 1 can be ensured.

[0060] In this embodiment, the lifting device is a vehicle body lifting cylinder 9, which is a hydraulic actuator suspended from the upper part of the vehicle body side frames 22 that form the left and right ends of the vehicle body 2, as will be described later, but any device may be used as the lifting device, for example, one that uses an electric motor. Furthermore, the lifting device does not have to be provided inside the vehicle body 2, as long as it is located on the outside of the vehicle body 2 on the left or right, or on the inside of the running frame 30 on the left or right.

[0061] In addition, the running frame 30 has a lower frame portion 30b below the upper frame portion 30u, between the front wheel 31F and the rear wheel 31R, and has space for arranging equipment between the upper frame portion 30u and the lower frame portion 30b of the running frame 30, on the side of the vehicle body 2, between the front wheel 31F and the rear wheel 31R.

[0062] In this embodiment, each of the left and right running frames 30L, 30R has a space for arranging equipment (for arranging the side battery 37) between the upper frame portion 30u and the lower frame portion 30b, but only one of the left and right running frames 30L, 30R may be configured in this manner.

[0063] Furthermore, as will be described later, the vehicle body 2 is connected to the running frame 30 so as to be movable in the vertical direction relative to the running frame 30, but when the vehicle body 2 is placed at the lowest position within the range of vertical movement relative to the running frame 30, it does not have any portion that vertically overlaps with the upper frame portion 30u of the running frame 30. For example, if the upper part of the vehicle body 2 has portions that protrude outward on the left and right, there is a possibility that these portions will vertically overlap with the upper frame portion 30u when the vehicle body 2 is at the lowest position, but in this embodiment, the vehicle body 2 does not have such protruding portions.

[0064] In other words, the configuration in which the vehicle body 2 and the running frame 30 do not have any vertically overlapping portions as described above also means that there are no portions that interfere with the equipment installation space above the upper frame portion 30u of the running frame 30 while the vehicle body 2 is moving up and down. If there were a portion that vertically overlaps with the upper frame portion 30u of the running frame 30 when the vehicle body 2 is at its lowest position, that portion could interfere with equipment installed in the equipment installation space provided in the upper frame portion 30u.

[0065] The car body 2 is connected to the traveling frame 30 via a mast mechanism 7 that is arranged laterally inward of the traveling frame 30. The mast mechanism 7 supports the car body 2, which moves up and down by the operation of the above-mentioned lifting device, and like the above-mentioned lifting device, the mast mechanism 7 is arranged laterally inward of the traveling frame 30, so that there is no part that interferes with the equipment placement space above the upper frame portion 30u of the traveling frame 30 while the car body 2 is moving up and down.

[0066] With the above-described configuration, regardless of whether the vehicle body 2 is raised or lowered, interference between the equipment on the vehicle body 2 side and the equipment arranged on the upper frame portion 30u of the running frame 30 is avoided, and ample space for arranging equipment is always secured on the running frame 30, making it possible to mount even equipment with a considerable volume.

[0067] The work vehicle 1 has wheels 31 and a traveling frame 30 on the left and right sides of the vehicle body 2, and the vehicle body 2 is disposed between a traveling frame 30L on the left side of the vehicle body 2 and a traveling frame 30R on the right side of the vehicle body 2.

[0068] The specific structure of the running frame 30 will be described in detail below. The running frame 30 has an upper frame portion 30u that forms its upper end. The upper frame portion 30u is a ladder-shaped portion consisting of a pair of left and right rods, an inner main rod 30u1 and an outer main rod 30u2, that extend in the front-to-rear direction, and multiple horizontal rods 30u3 that extend in the left-to-right direction to connect the inner main rod 30u1 and the outer main rod 30u2.

[0069] As can be seen from the plan view of Figure 6, the front end of the upper frame portion 30u is located forward of the front end of the front wheel 31F, and the rear end of the upper frame portion 30u is located between the rear end of the rear wheel 31R and the axle 31a of the rear wheel 31R.

[0070] The inner main rod 30u1 defines the left and right inner ends of the running frame 30, and the outer main rod 30u2 defines the left and right outer ends of the running frame 30. That is, in the upper frame portion 30u of the left running frame 30L of the left running structure 3L, the inner main rod 30u1 is located on the right side and the outer main rod 30u2 is located on the left side, and in the upper frame portion 30u of the right running frame 30R of the right running structure 3R, the inner main rod 30u1 is located on the left side and the outer main rod 30u2 is located on the right side.

[0071] The front ends of the inner main rod member 30u1 and the outer main rod member 30u2 define the front end of the running frame 30, and the rear ends of the inner main rod member 30u1 and the outer main rod member 30u2 define the rear end of the running frame 30. In other words, the upper frame portion 30u is configured to be long in the front-to-rear direction, extending from the front end to the rear end of the running frame 30.

[0072] In addition, the left-right width of the upper frame portion 30u, which is the sum of the length of each horizontal rod member 30u3 extending in the left-right direction and the left-right width of the inner main rod member 30u1 and the outer main rod member 30u2, defines the left-right width of the running frame 30.

[0073] The left and right width of this running frame 30 is long enough so that the left and right ends of the wheel unit 4 do not extend outward to the left or right beyond the left and right ends of the running frame 30. Therefore, parts and members included in the running structure 3, or equipment provided on the running structure 3, do not extend outward from the running structure 3 and intrude into the car body 2 located inside the left and right of the running structure 3, and therefore do not interfere with the up and down movement of the car body 2 relative to the running structure 3, which will be described later.

[0074] The upper frame portion 30u configured as described above ensures a wide range of free space above the running frame 30 in both the front-to-rear and left-to-right directions. The upper frame portion 30u includes a plurality of rectangular (rectangular or square) frames in plan view, each consisting of left and right inner and outer main rods 30u1 and 30u2 and a pair of front and rear cross rods 30u3, arranged in a continuous front-to-rear direction. The upper end surfaces of the rods 30u1, 30u2, and 30u3 constituting the upper frame portion 30u are flush with each other, and the upper end surfaces of the rectangular frames are flat. Therefore, the flat surface of the frame can be used as an installation surface for equipment. Since this flat surface extends from the front end to the rear end of the upper frame portion 30u, a wide space spanning the entire front-to-rear direction of the upper frame portion 30u from the front end to the rear end is secured above the upper frame portion 30u, allowing various equipment to be arranged in various layouts in this space.

[0075] If the upper frame portion 30u is divided into three parts in the fore-and-aft direction, namely, a front part, a middle part, and a rear part, the front part of the upper frame portion 30u is positioned above the front wheel 31F, the rear part of the upper frame portion 30u is positioned above the rear wheel 31R, and the middle part of the upper frame portion 30u is positioned between the front wheel 31F and the rear wheel 31R in the fore-and-aft direction.

[0076] That is, above the front wheels 31F, a space that can be used for installing equipment (the flat surfaces of the rectangular frame described above) is provided in the front part of the upper frame 30u, and above the rear wheels 31R, a space that can also be used for installing equipment (the flat surfaces of the rectangular frame described above) is provided in the rear part of the upper frame 30u, and these front and rear spaces are connected via the middle part of the upper frame 30u. Therefore, at the top of the upper frame 30u, a space for installing equipment made up of multiple flat surfaces of the rectangular frame is provided over a long range from above the front wheels 31F to above the rear wheels 31R.

[0077] The upper part of the wheel drive case 32 of the front wheel unit 4F (motor storage section 32a and transmission mechanism storage section 32b) passes through the space between the front and rear horizontal rod members 30u3 that constitute the front part of the upper frame section 30u of the running frame 30, protrudes upward from the front part of the upper frame section 30u, and is attached and fixed to at least one horizontal rod member 30u3.

[0078] A plurality of rods extend downward from the front of the upper frame portion 30u, and these rods form a front fender portion 30f that covers the rotating tube portion 32c of the wheel drive case 32 of the front wheel unit 4F and the front steering cylinder 35F directly above the front wheel 31F.

[0079] The multiple rods that make up the front fender section 30f include a vertical rod 30v1 that extends downward from the front end of the inner main rod 30u1. A plate-shaped mast mounting plate 30c1 extends forward of the vertical rod 30v1, extending forward and backward and up and down. Traveling-side mast members 71 of the mast mechanism 7 (7F), described below, are attached and fixed to the left and right inner surfaces of the mast mounting plate 30c1 (the surfaces facing the sides of the vehicle body 2).

[0080] The upper part of the wheel drive case 32 of the rear wheel unit 4R (motor storage section 32a and transmission mechanism storage section 32b) passes through the space between the front and rear horizontal rod members 30u3 that constitute the rear part of the upper frame portion 30u of the running frame 30, protrudes upward from the rear of the upper frame portion 30u, and is attached and fixed to at least one horizontal rod member 30u3.

[0081] A plurality of rods extend downward from the rear of the upper frame portion 30u, and these rods form a rear fender portion 30r that covers the rotating tube portion 32c of the wheel drive case 32 of the rear wheel unit 4R and the rear steering cylinder 35R directly above the rear wheel 31R.

[0082] As described above, of the free space provided at the top of the upper frame portion 30u, the front portion is used to position the upper portion of the wheel drive case 32 of the front wheel unit 4F, and the rear portion is used to position the upper portion of the wheel drive case 32 of the rear wheel unit 4R.

[0083] A large free space is still secured above the upper frame portion 30u between the front wheel unit 4F and the rear wheel unit 4R. This space can be used to mount various devices on the upper frame portion 30u.

[0084] For example, when a chemical spraying device is connected to the work vehicle 1 as the work device 200, it is conceivable that a chemical tank for storing the chemical to be supplied to the chemical spraying device could be mounted in this portion of the upper frame portion 30u.

[0085] Here, the upper frame portion 30u has a left-right width large enough to cover the left-right width of the wheel unit 4 having the wheels 31 and the wheel drive case 32, so that even a large-capacity drug tank can be mounted on the upper frame portion 30u so that it does not protrude beyond the left and right outer ends of the running structure 3.

[0086] Between the front fender section 30f and the rear fender section 30r, an intermediate fender section 30m is formed so as to extend downward from the middle section of the upper frame section 30u. More specifically, as shown in Figure 7, a vertical rod member 30v2 that defines the front end of the intermediate fender section 30m (the rear end of the front fender section 30f) and a vertical rod member 30v3 that defines the rear end of the intermediate fender section 30m (the front end of the rear fender section 30r) extend downward from the inner main rod member 30u1.

[0087] Meanwhile, vertical rod 30v4 extends downward from outer main rod 30u2 at a position corresponding to vertical rod 30v2 in the fore-and-aft direction, and vertical rod 30v5 extends downward at a position corresponding to vertical rod 30v3 in the fore-and-aft direction. These four vertical rods 30v2, 30v3, 30v4, and 30v5 form a rectangular middle fender section 30m whose four corners are defined by these four vertical rods.

[0088] The lower ends of the vertical rods 30v2, 30v3, 30v4, and 30v5 are connected to each other by horizontal bottom rods 30b1, 30b2, 30b3, and 30b4 arranged in a rectangular shape. In this manner, the bottom rods 30b1, 30b2, 30b3, and 30b4 form the lower frame portion 30b at the bottom of the intermediate fender portion 30m.

[0089] The battery case 36 is placed across the front and rear bottom rods 30b1 and 30b4 that extend in the left-right direction and make up the lower frame portion 30b. The battery case 36 placed on the lower frame portion 30b in this manner is positioned so as to be surrounded by the vertical rods 30v2, 30v3, 30v4, and 30v5 that make up the middle fender portion 30m. In other words, the battery case 36 is positioned in the space formed between the upper frame portion 30u and the lower frame portion 30b of the running frame 30, between the front wheel 31F and the rear wheel 31R.

[0090] The vertical rods 30v2 at the front ends of the left and right inner sides of the intermediate fender section 30m support the middle mast mechanism 7M described below, and the vertical rods 30v3 at the rear ends of the left and right inner sides of the intermediate fender section 30m support the rear mast mechanism 7R described below.

[0091] That is, a plate-shaped mast mounting plate 30c2 extending left and right and up and down is provided on the left and right inner side (towards the car body 2) of the vertical rod 30v2. The traveling-side mast member 71 of the intermediate mast mechanism 7M is attached and fixed to the front surface of the mast mounting plate 30c2.

[0092] Additionally, a plate-shaped mast mounting plate 30c3 extending in the front-to-rear and up-and-down directions is provided behind the vertical rod 30v3. The traveling-side mast member 71 of the rear mast mechanism 7R is attached and fixed to the inner lateral surfaces of the mast mounting plate 30c3 (the side facing the vehicle body 2).

[0093] This concludes the configuration of each traveling structure 3, i.e., the left traveling structure 3L and the right traveling structure 3R. Next, the configuration of the vehicle body 2 and various devices supported by the vehicle body 2, which are arranged between the left traveling structure 3L and the right traveling structure 3R, will be described.

[0094] As shown in FIGS. 1 to 6 , the vehicle body 2 has a vehicle body frame structure 20 , a front body case (battery case) 24 and a rear body case (PTO case) 26 supported by the vehicle body frame structure 20 .

[0095] The body frame structure 20 has a body center frame 21, a left body side frame 22L disposed on the left side of the body center frame 21, and a right body side frame 22R disposed on the right side of the body center frame 21. Hereinafter, each of the left body side frame 22L and the right body side frame 22R may be referred to as a body side frame 22.

[0096] The vehicle body central frame 21 has a pair of left and right main rod members 21a extending in the front-rear direction, and a plurality of horizontal tube members 21b extending in the left-right direction so as to connect the left and right main rod members 21a.

[0097] A flat support member 23 is fixed to the lower part of the vehicle body center frame 21 from the front end to the midway portion in the front-rear direction, and a rectangular parallelepiped front main body case 24 hangs down from the support member 23. The upper end of the front main body case 24 is engaged with the support member 23 so as to be movable in the front-rear direction.

[0098] In detail, the support member 23 has a flat plate portion 23a (see Figure 6, etc.) attached to the bottom surface of the front part of the vehicle body center frame 21, and a rail member 23b (see Figure 4) that extends in the fore-and-aft direction, hangs down from the flat plate portion 23a, and has a round bar-shaped rail at the bottom that extends in the fore-and-aft direction.

[0099] Meanwhile, an engagement member 24a (see FIG. 4) extending in the front-rear direction corresponding to the rail member 23b of the support member 23 protrudes upward from the upper end surface of the front main body case 24. A groove extending in the front-rear direction is formed in the engagement member 24a. By fitting a round bar-shaped rail provided on the rail member 23b into this groove, the engagement member 24a engages with the rail member 23b so as to be slidable forward and backward, whereby the front main body case 24 is supported by the support member 23 so as to be movable forward and backward.

[0100] The support member 23 and the front main body case 24 may be provided with multiple sets of rail members 23b and engaging members 24a in order to ensure the support strength of the support member 23 for the front main body case 24, which becomes heavy when the center battery 50 (described later) is stored in it. In this embodiment, four such sets are provided, but the number is not limited to four.

[0101] Furthermore, as shown in FIG. 4, the support member 23 has support side plates 23c extending vertically from both the left and right sides of the front case body 24, and horizontal surfaces extending forward and backward below the support side plates 23c to support the front case body 24 from below.

[0102] The configuration for supporting the front main body case 24 so that it can move in the fore-and-aft direction on the body frame structure 20 is not limited to the one described above, and any structure can be used as long as it ensures that the front main body case 24 can move in the fore-and-aft direction relative to the support member 23 and the body central frame 21.

[0103] Each vehicle side frame 22 has a main rod member 22a extending in the fore-and-aft direction, horizontal rod members 22b (see Figures 6, 9, etc.) extending inward from the main rod member 22a to the left and right, and multiple vertical rod members 22c extending vertically downward from the main rod member 22a.

[0104] Furthermore, the vertical lengths of the multiple vertical rod members 22c are uniform, and the vertical length from the upper end of the main rod member 22a to the lower end of the vertical rod member 22c approximately matches the maximum vertical width of the running frame 30 of the running structure 3 (the vertical width from the upper end of the upper frame portion 30u to the lower end of the lower frame portion 30b).

[0105] In this embodiment, each vehicle body side frame 22 is provided with a plurality of vertical rods 22c, namely, five vertical rods 22c1, 22c2, 22c3, 22c4, and 22c5, arranged in this order from the front end to the rear of the vehicle body side frame 22. Each of the vertical rods 22c is used to support the mast mechanism 7, which will be described later.

[0106] Each horizontal rod 22b is slidably inserted into each horizontal tube 21b of the vehicle body center frame 21. In this embodiment, each vehicle body side frame 22 has three horizontal rods 22b arranged at the front, middle, and rear, and correspondingly, the vehicle body center frame 21 also has three horizontal tubes 21b arranged at the front, middle, and rear.

[0107] Both left and right ends of each horizontal tube member 21b of the vehicle body central frame 21 are open ends, and each horizontal rod member 22b of the left vehicle body side frame 22L is inserted into each horizontal tube member 21b from the left open end of each horizontal tube member 21b, and each horizontal rod member 22b of the right vehicle body side frame 22R is inserted into each horizontal tube member 21b from the right open end of each horizontal tube member 21b.

[0108] The number and position of the horizontal rods 22b in each vehicle side frame 22 are not limited to those described above, and it is sufficient that at least one horizontal rod is provided in any part of the vehicle side frame 22.

[0109] Furthermore, it is sufficient that each vehicle side frame 22 is connected to the vehicle center frame 21 so that it can move freely relative to the vehicle side frame 21 in the left-right direction, and the connection may be by a structure different from the structure in which the horizontal rod member 22b of the vehicle side frame 22 is inserted into the horizontal tube member 21b of the vehicle center frame 21 as described above.

[0110] 9, in the vehicle body 2 configured with the vehicle body frame structure 20 having such a structure, changes in the extension amount (protrusion amount) of the horizontal rod member 22b protruding from the horizontal tube member 21b change the left-right distance between the left vehicle body side frame 22L and the left end of the vehicle body center frame 21 and / or the left-right distance between the right vehicle body side frame 22R and the right end of the vehicle body center frame 21. In other words, the width of the vehicle body 2 in the left-right direction changes, and the vehicle body 2 is deformed.

[0111] Furthermore, by deforming the vehicle body 2 in the form of changing the left-right width, the vehicle width, which is the left-right distance between the left running structure 3L and the right running structure 3R, i.e., the distance between the left front wheel 31FL and the right front wheel 31FR and / or the distance between the left rear wheel 31RL and the right rear wheel 31RR, can be changed.

[0112] A pair of width-changing cylinders 8A, 8B extending in the left-right direction are provided on the upper part of the vehicle body central frame 21 as a vehicle body deformation device (actuator) 80 (see FIG. 8 ) for changing the left-right width of the vehicle body 2, i.e., for deforming the vehicle body 2. Hereinafter, each of the pair of width-changing cylinders 8A, 8B may be referred to as a width-changing cylinder 8.

[0113] The width-adjusting cylinder 8A extends and retracts to change the distance between the vehicle center frame 21 and the left vehicle side frame 22L. The cylinder body of the width-adjusting cylinder 8A is attached to the upper part of the vehicle center frame 21, and the piston rod extends leftward from the cylinder body, with the tip of the piston rod attached to the main rod 22a at the upper part of the left vehicle side frame 22L.

[0114] The width-adjusting cylinder 8B extends and retracts to change the distance between the vehicle center frame 21 and the right vehicle side frame 22R. The cylinder body of the width-adjusting cylinder 8B is attached to the upper part of the vehicle center frame 21 in front of or behind (in this embodiment, in front of) the cylinder body of the width-adjusting cylinder 8A, and the piston rod extends rightward from the cylinder body, with the tip of the piston rod attached to the main rod 22a at the upper part of the right vehicle side frame 22R.

[0115] In this way, the extension and contraction of each width-changing cylinder 8 changes the amount of protrusion of the horizontal rod member 22b from the horizontal tube member 21b, causing the vehicle side frame 22 to move forward and backward relative to the vehicle center frame 21, changing the left-right width of the vehicle body 2 as described above and deforming the vehicle body 2.

[0116] For example, by extending both (the piston rods of) the width-changing cylinders 8A and 8B, as shown in Figure 9, both the left body side frame 22L and the right body side frame 22R move away from the body center frame 21, and the body 2 is deformed so that both the left and right parts expand.

[0117] As a result, the left running structure 3L connected to the left vehicle side frame 22L and the right running structure 3R connected to the right vehicle side frame 22R move away from each other in the left-right direction, and the left-right distance between the left running structure 3L and the right running structure 3R, and the vehicle width, which is the distance between the corresponding left and right wheels 31, increases.

[0118] In addition, when deforming the vehicle body 2 in the direction of increasing the vehicle width, it is not necessary to extend and retract both the left vehicle body side frame 22L and the right vehicle body side frame 22R in synchronous fashion; only one of the width change cylinders 8A, 8B may be extended and retracted to move only one of the left vehicle body side frame 22L and the right vehicle body side frame 22R.

[0119] The width-changing cylinder 8, which serves as a body deformation device for changing the left-right width of the body 2, may be a cylinder of any structure, such as a hydraulic cylinder, an air cylinder, or an electric cylinder, as long as it functions as the body deformation device 80.

[0120] Furthermore, the body deformation device 80 does not have to have a structure with a cylinder such as the width change cylinder 8, as long as it has the function of changing the left and right width of the body 2, and may have a structure such that the body side frame 22 moves forward and backward relative to the body center frame 21 by rotating a screw rod with a motor, for example.

[0121] The left and right outer end faces of each vehicle body side frame 22 and the left and right inner end faces of the running frame 30 of the corresponding running structure 3 facing each other are vertical planes that are parallel to each other. In other words, each vehicle body side frame 22 does not have a portion that extends outward to the left or right and reaches above the upper frame portion 30u of the running frame 30 of each running structure 3, which would hinder the placement of equipment on the upper frame portion 30u of the running frame 30 of each running structure 3. This allows the entire left-right width of the upper frame portion 30u of the running frame 30 of each running structure 3 to be effectively used for mounting equipment.

[0122] For example, all of the horizontal rods 22b of the left vehicle body side frame 22L extend from the main rod 22a toward the left and right inner side of the vehicle body 2, opposite the left running structure 3L, and a flat vertical surface is formed from the top to bottom end of the left end faces of the multiple vertical rods 22c (vertical rods 22c1, 22c2, 22c3, 22c4, 22c5) that extend vertically downward from the main rod 22a of the left vehicle body side frame 22L, that is, at the left (left and right outer) end of the left vehicle body side frame 22L.

[0123] On the other hand, at the right end of the left running frame 30L of the left running structure 3L, a flat vertical surface is formed from the top to the bottom at the right end faces of the vertical rod members 30v1, 30v2, and 30v3 that extend vertically downward from the inner main rod member 30u1, that is, at the right (left and right inner) end of the left running frame 30L.

[0124] In this way, the vertical plane at the left side (outer left and right) end of the left vehicle side frame 22L and the vertical plane at the right side (inner left and right) end of the left running frame 30L are parallel, and a constant left-right width gap is secured between the two vertical planes in the fore-and-aft direction.Furthermore, the equipment mounted on the vehicle body 2 is all arranged between the left vehicle side frame 22L and the right vehicle side frame 22R, without protruding to the left from the left vehicle side frame 22L or to the right from the right vehicle side frame 22R.As a result, the left vehicle side frame 22L and the left running frame 30L do not interfere with each other, for example, when the vehicle body 2 moves up and down relative to the running structure 3, and a wide free space in the left-right direction can also be secured above the upper frame portion 30u of the left running frame 30L.

[0125] The right vehicle body side frame 22R and the right running frame 30R have a similar structure, and a constant left-right width is similarly maintained between the right side (left-right outer) end of the right vehicle body side frame 22R and the left side (left-right inner) end of the right running frame 30R in the fore-and-aft direction. Furthermore, as mentioned above, the equipment mounted on the vehicle body 2 is all positioned between the left vehicle body side frame 22L and the right vehicle body side frame 22R, without protruding to the left from the left vehicle body side frame 22L or to the right from the right vehicle body side frame 22R, thereby achieving the same effect, namely, the right vehicle body side frame 22R and the right running frame 30R do not interfere with each other when the vehicle body 2 moves up and down relative to the right running frame 30R.

[0126] The left vehicle body side frame 22L of the vehicle body frame structure 20 is connected to the left running frame 30L of the left running structure 3L, and the right vehicle body side frame 22R is connected to the right running frame 30R of the right running structure 3R, via multiple mast mechanisms 7 arranged between the vehicle body 2 (each vehicle body side frame 22) and each running structure 3 (each running frame 30), so that they can move up and down relative to the left and right running structures 3. The configuration of the mast mechanisms 7 will be described in detail later.

[0127] The work vehicle 1 is provided with a pair of left and right body lifting cylinders 9, i.e., a left body lifting cylinder 9L and a right body lifting cylinder 9R, which serve as actuators (hydraulic actuators) for raising and lowering the body 2, i.e., as a body moving device 90 (see Figure 8) for moving the body 2 relative to the left and right running structures 3.

[0128] The cylinder bottoms, which are the upper ends of each body lift cylinder 9 (left body lift cylinder 9L, right body lift cylinder 9R), are connected to the lower parts of the main rod members 22a of the body side frames 22. Meanwhile, the piston rod heads, which are the lower ends of each body lift cylinder 9, are supported by brackets or the like that protrude inwardly (towards the body 2) from the inner left and right ends of the running frame 30.

[0129] That is, in the left-right direction of the work vehicle 1, each body lifting cylinder 9, the upper ends of which are connected to the upper parts of each body side frame 22, is positioned in a position offset left-right inward from the left-right inner ends of the traveling structure 3. In other words, each body lifting cylinder 9 does not protrude left or right outward from the corresponding body side frame 22, and the body lifting cylinder 9 does not intrude into the traveling frame 30 or the space above the traveling frame 30. This also ensures that a large free space is available above the upper frame portion 30u of the traveling frame 30 of each traveling structure 3, where various equipment can be mounted.

[0130] Under normal circumstances, the piston rods of the left body lift cylinder 9L and the right body lift cylinder 9R are retracted, and the body 2 is located at the lowest position in its vertical movement range, as shown in Figures 1 to 5. The left body lift cylinder 9L and the right body lift cylinder 9R simultaneously extend their piston rods with the same stroke, thereby raising the entire body 2. More specifically, as the piston rods of the left body lift cylinder 9L and the right body lift cylinder 9R extend, the body 2 moves upward relative to the left and right traveling structures 3 while being guided by the mast mechanism 7.

[0131] It is also conceivable that the left and right tilt of the vehicle body 2 can be adjusted by differentially extending and retracting the left body lifting cylinder 9L and the right body lifting cylinder 9R. For example, if the ground tilts downward and left and the left running structure 3L becomes lower than the right running structure 3R, causing the vehicle body 2 to tilt downward and left, it is conceivable that by extending only the left body lifting cylinder 9L, the left part of the vehicle body 2 can be moved upward relative to the left running structure 3L, thereby keeping the vehicle body 2 horizontal in the left and right directions.

[0132] The body lifting cylinders 9 do not have to be a pair on the left and right, and there are no restrictions on the number or location within the body 2. The actuator that moves the body 2 up and down does not have to be an extendable actuator like the body lifting cylinders 9, and may be configured to move the body 2 up and down by the rotation of an electric motor, for example.

[0133] In this embodiment, as described above, the width-changing cylinder 8, which is the body deformation device 80, and the body lifting cylinder 9, which is the body movement device 90, are hydraulic actuators, and the control device 15 controls the respective control valves in the control valve unit 27 to control their extension and contraction movements.

[0134] In addition, the width change cylinder 8 and the vehicle body lifting cylinder 9 described in Figure 8 refer to the width change cylinders 8A and 8B and the vehicle body lifting cylinders 9L and 9R, respectively, and the control device 15 can individually control the extension and contraction movement of each of these.

[0135] 11 to 13, a battery (center battery) 50 is housed in the front body case 24. In consideration of the weight balance of this heavy battery 50 within the entire work vehicle 1, or for other reasons (for example, in relation to the layout of equipment within the body 2), the front body case 24 is movable in the fore-and-aft direction relative to the body center frame 21 (body frame structure 20). In other words, the body 2 is also deformed when the front body case 24 moves fore-and-aft relative to the body center frame 21.

[0136] Note that a battery movement actuator 81, such as a hydraulic cylinder, may be provided as a vehicle body transformation device 80 (see FIG. 8 ) to move the front body case 24 forward and backward relative to the vehicle body center frame 21. Alternatively, without providing such a vehicle body transformation device, an operator may directly push or pull the front body case 24 with his or her hands to move it forward and backward relative to the vehicle body center frame 21.

[0137] An air temperature adjustment device (air conditioning unit) 51 is attached to the front end surface of the front main body case 24 in a forward protruding manner, and a radiator 52 is provided immediately in front of the air temperature adjustment device 51. A radiator fan 52a is provided at the front end of the radiator 52. In other words, an air cooling device and a water cooling device are provided immediately in front of the front main body case 24.

[0138] The air temperature adjusting device 51 and the radiator fan 52 a of the radiator 52 can be operated by power supplied from the battery 50 .

[0139] 5, 12, and 13, a bracket 25 hangs down from the vehicle center frame 21 behind the front main body case 24, which houses the battery (center battery) 50. A rear main body case (PTO case) 26 hangs down from the lower end of the bracket 25.

[0140] In this way, the rear body case 26 is disposed behind the front body case 24 and is supported by the body frame structure 20 of the vehicle body 2 via the brackets 25 .

[0141] As mentioned above, when the front main body case 24 is moved forward relative to the vehicle center frame 21 in consideration of weight balance, etc., a space S1 having a certain width in the fore-and-aft direction is created between the rear end of the front main body case 24 and the bracket 25 fixed to the vehicle center frame 21 behind it, as shown in Figure 12.

[0142] This space S1 will be described below. That is, the work vehicle 1 includes a vehicle body 2 that is movable in the vertical direction, a first device mounted on the vehicle body 2, a second device mounted on the vehicle body 2, left and right traveling structures 3L, 3R provided on the left and right sides of the vehicle body 2, and a movement mechanism that moves the vehicle body 2 in the vertical direction, the vehicle body 2 has a space S1 formed between at least the first device and the second device, and the movement mechanism is configured to position the space S1 at least between the first device and the second device and between the left and right traveling structures 3L, 3R when the vehicle body 2 is in the most lowered state, and to position the space S1 at least between the first device and the second device and above the left and right traveling structures 3L, 3R when the vehicle body 2 is in the most raised state.

[0143] The moving mechanism is the aforementioned vehicle body moving device 90, which in this embodiment is the vehicle body lifting cylinders 9L, 9R, which are hydraulic actuators, but as mentioned above, it is not limited to such telescopic hydraulic actuators, and actuators of various configurations can potentially be used as the moving mechanism, which is the vehicle body moving device 90.

[0144] In addition, in this embodiment, the first device is the battery 50 housed in the front main body case 24, and the second device is the electrical equipment (electric motor 53) and hydraulic equipment (hydraulic pump 55) housed in the rear main body case 26, but the present invention is not limited to these, and for example, the first device and the second device may be reversed. Also, for example, if a sprayer for chemicals or the like is attached to the vehicle body 2 as a work device, the sprayer or the chemical tank may be the first device or the second device, and there is no limitation on the type of device.

[0145] It is also conceivable that the vehicle body 2 has a space S1 behind the first device mounted in the front part of the vehicle body 2. In this case, the position of the first device is specified as the front part of the vehicle body 2, but the position of the second device is not specified. In the case of a work vehicle 1 configured as described above, it is conceivable that the space S1 is provided behind the radiator 52 disposed at the front end of the vehicle body 2, for example, and the battery 50 housed in the front main body case 24 is disposed behind the space S1 as the second device.

[0146] It is also conceivable that the vehicle body 2 has a space S1 between the first device and the second device mounted on the rear of the vehicle body 2. In this case, the position of the second device is specified as the rear of the vehicle body 2, but the position of the first device is not specified. In the case of a work vehicle 1 configured as described above, for example, the second device could be a working device mounted on the upper rear end of the rear main body case 26 or a coupling device for coupling the working device, and the control valve unit 27 attached to the bracket 25 supporting the rear main body case 26 in front of it could be the first device, and the space above the rear main body case 26 between the first device and the second device could be the space S1.

[0147] Furthermore, the vehicle body is configured so that the position of the first device can be changed in the fore-and-aft direction, and it is considered that the vehicle body 2 can be switched between a state in which the space S1 is present and a state in which the space S1 is not present by changing the position of the first device. In this embodiment, as described above, the position of the battery 50 as the first device can be changed in the fore-and-aft direction, but this is not limited to this. For example, as described above, the application of the first device and the second device can be reversed, and the electrical equipment and hydraulic equipment in the rear main body case 26 can be the first device, and the rear main body case 26 can be moved in the fore-and-aft direction, so that the vehicle body 2 can be switched between a state in which the space S1 is present and a state in which the space S1 is not present.

[0148] In addition, in this embodiment, the work vehicle 1 is provided with a battery movement actuator 81 as a device for changing the position of the first device forward or backward, assuming that the first device is the battery 50, but this is not limited to this. The configuration of the means for moving the first device may be determined depending on what device is used as the first device, and as described above, an actuator may not be provided and the first device may be moved manually by the worker.

[0149] The specific configuration of this space S1 will now be described.

[0150] That is, in this embodiment, by moving the front main body case 24 back and forth, it is possible to switch between a state in which there is a space S1 between equipment such as the battery 50 housed in the front main body case 24 and electrical equipment such as the electric motor 53 described below and hydraulic equipment such as the hydraulic pump 55 described below housed in the rear main body case 26, as shown in FIG. 13 , and a state in which there is no space S1.

[0151] As shown in Figures 12 and 13, when the space S1 is created by moving the front main body case 24 forward together with the battery 50, the space S1 can be used to attach, for example, a hydraulic oil tank 58 for storing hydraulic oil to be supplied to hydraulic actuators etc. provided on the work vehicle 1 to the front part of the bracket 25.

[0152] In the normal state in which the vehicle body 2 is lowered, this space S1 is covered on the left and right sides by the left running structure 3L and the right running structure 3R, and the front is covered by equipment such as the battery 50 housed in the front main body case 24, and the rear is covered by equipment such as hydraulic equipment and electrical equipment housed in the rear main body case 26.As it is covered from all four sides, front, back, left and right, it is possible to ensure protection of equipment such as the hydraulic oil tank 58 provided within the space S1.

[0153] On the other hand, when the vehicle body 2 is raised, the space S1 is exposed above the left and right traveling structures 3, and an operator can access the space S1 by inserting his / her hand into the space S1, etc. Therefore, when the vehicle body 2 is raised, it is possible to remove equipment such as the hydraulic oil tank 58 in the space S1.

[0154] To explain in detail the state of the space S1 when the vehicle body 2 is raised, during this raising, the front and rear of the space S1 remain covered from both sides by the equipment such as the battery 50 housed in the front main body case 24 and the hydraulic equipment and electrical equipment housed in the rear main body case 26, but since the space S1 is located above the left and right running structures 3L, 3R, there are no running structures 3 on either side of it. Therefore, the space S1 is open on both the left and right sides, i.e., it is in a state where it is penetrated left and right and exposed on both the left and right sides.

[0155] Furthermore, by leaving the entire space S1 as free space without installing equipment such as a hydraulic oil tank 58, it is possible for an operator to insert their hand into the front main body case 24 through the space S1 to perform maintenance on the battery 50, for example.

[0156] Furthermore, since a sufficiently large tolerance is ensured for the front body case 24, which houses the center battery 50, to move forward and backward relative to the body frame structure 20 of the vehicle body 2, the size of the space S1 formed by the forward movement of the front body case 24 is not so small that an operator can just barely insert the fingertips of one hand by moving the front body case 24 forward a large distance, but rather, as described above, a space S1 large enough for an operator to insert one hand deep into the space S1 to perform maintenance work or to position components such as the hydraulic oil tank 58 can be provided.

[0157] An electric motor 53 and an inverter 54 (see FIGS. 8 and 12 ) serving as a working motor are housed within the rear main body case 26. A PTO shaft 5 is journaled within the rear main body case 26. As shown in FIG. 5 , the PTO shaft 5 protrudes rearward from the rear end of the rear main body case 26, which serves as the rear end of the vehicle body 2.

[0158] The electric motor 53 is driven by power obtained from the center battery 50, and the output drives the PTO shaft 5. The inverter 54 converts the direct current from the center battery 50 into alternating current and applies the alternating current to the electric motor 53 at a set voltage and / or frequency.

[0159] As shown in Figure 8, the set value of the voltage and / or frequency of the inverter 54 is controlled by the control device 15, thereby controlling the output rotation speed and / or torque of the electric motor 53, and thereby controlling the rotation speed and / or torque of the PTO shaft 5.

[0160] A transmission mechanism for transmitting the output of the electric motor 53 to the PTO shaft 5 may be provided inside the rear main body case 26. This transmission mechanism may have a gear, an endless belt, or another structure. This transmission mechanism may also be a stepped or continuously variable transmission mechanism. Furthermore, this transmission mechanism may be provided with a clutch, a braking device, or the like.

[0161] 5, 12, etc., a pair of left and right lower link brackets 26a are provided at the lower left and right corners of the rear end of rear main body case 26. In addition, a top link bracket 26b is provided at the middle position between the left and right on the upper part of the rear end surface of rear main body case 26.

[0162] When the connecting device 6, which is a three-point link mechanism, is attached to the vehicle body 2, the front ends of the left and right lower links 6a are attached to the left and right lower link brackets 26a, and the front end of the top link 6b is attached to the top link bracket 26b.

[0163] As shown in Figures 5 and 6, a lift arm base 26c that rotatably supports a pivot shaft extending in the left-right direction is provided on the upper end surface of the rear main body case 26, and a pair of left and right lift cylinder brackets 26d are provided on the lower part of the rear end surface of the rear main body case 26.

[0164] When the connecting device 6, which is a three-point link mechanism, is attached to the rear main body case 26, the front ends of a pair of left and right lift arms 60 are attached to the left and right ends of the rotation fulcrum shaft supported by the lift arm base 26c. As a result, the left and right lift arms 60 are pivotally supported by the lift arm base 26c so as to be rotatable integrally.

[0165] A lift cylinder 61 is interposed between the left lift arm 60 and the left lift cylinder bracket 26d, and between the right lift arm 60 and the right lift cylinder bracket 26d.

[0166] The left and right lift cylinders 61 are configured to extend and retract in sync, and the extension and retraction of the left and right lift cylinders 61 causes the left and right lift arms 60 to rotate integrally around the rotation fulcrum shaft at the front end.

[0167] Furthermore, as shown in FIGS. 5 and 6, one of the left and right lift arms 60 is connected to the corresponding lower link 6a via a lift rod 62 having a fixed length, while the other of the left and right lift arms 60 is connected to the corresponding lower link 6a via an extendable attitude adjustment cylinder 63.

[0168] In this way, the left and right lower links 6a are connected to the left and right lift arms 60 via the lift rods 62 and the attitude adjustment cylinders 63, so that the rear ends of the left and right lower links 6a move up and down in response to the up and down movement of the rear ends of the left and right lift arms 60 due to the extension and contraction of the left and right lift cylinders 61. As a result, the working device 200 attached to the rear ends of the left and right lower links 6a and the rear end of the top link 6b of the connecting device 6 moves up and down (raise and lower).

[0169] Furthermore, by adjusting the difference between the distance between the rear end of the left lift arm 60 and the rear end of the left lower link 6a and the distance between the rear end of the right lift arm 60 and the rear end of the right lower link 6a by extending and retracting the posture adjustment cylinder 63, the tilt angle in the left-right direction of the working device 200 attached to the connecting device 6 can be adjusted.

[0170] With this configuration, even if the working implement 200 during agricultural work begins to tilt left or right due to the slope of the field, the working implement 200 can be kept horizontal in the left-right direction by adjusting the distance between the lift arm 60 and the lower link 6a by extending and retracting the posture adjustment cylinder 63, and good ridges that do not slope left or right can be formed in the work marks of the working implement 200, which is, for example, a ridge-forming device.

[0171] As described above, the working device 200 can be connected to the coupling device 6 attached to the rear of the rear main body case 26 (rear part of the vehicle body 2). Furthermore, the working device 200 connected to the rear of the vehicle body 2 via the coupling device 6 can receive driving force from the PTO shaft 5 protruding from the rear end face of the rear main body case 26.

[0172] Examples of the working device 200 include, but are not limited to, devices that perform agricultural work (farm work), devices that perform civil engineering work, devices that perform construction work, devices that perform transportation work, etc. In the embodiment described below, the working device 200 is a device that performs farm work.

[0173] Examples of the working device 200 for performing agricultural work include a spraying device for spreading fertilizer, chemicals, and other such materials, a sowing device for sowing seeds, a tilling device for tilling the soil, a tilling device (plow) for tilling the soil, a weeding device for weeding, a soil-piling device for piling up soil, etc. However, the type of working device 200 is not particularly limited as long as it is a device for performing agricultural work.

[0174] Furthermore, if the working device 200 is an electrically powered working device, instead of being driven by power taken from the PTO shaft 5, it may be driven by power taken from the battery 50 via a power line to the outside of the vehicle body 2.

[0175] The working device 200 may be coupled to the work vehicle 1 while being disposed to the side or front of the vehicle body 2. Furthermore, for example, when the working device 200 is disposed at the front of the work vehicle 1, the coupling device 6 may be attached to the front body case 24, for example, and the working device 200 disposed at the front of the work vehicle 1 may be coupled to the work vehicle 1 via the coupling device 6 thus attached to the front of the vehicle body 2.

[0176] Furthermore, in addition to or instead of the PTO shaft 5 provided at the rear of the vehicle body 2, a front PTO shaft may be provided facing forward from the front body case 24, and the front PTO shaft may drive the implement 200 at the front of the work vehicle 1. Note that an example of such a front-mounted agricultural implement 200 is a combine unit that combines the reaping section, threshing section, sorting section, etc. of a combine harvester.

[0177] In addition, the aforementioned lower link bracket 26a, top link bracket 26b, and lift cylinder bracket 26d may be removable from the rear end of the rear main body case 26, or may be selected depending on the configuration of the connecting device 6 to be attached to the rear main body case 26 and attached to the rear end of the rear main body case 26.

[0178] It is also possible to provide an attachment portion to which the coupling device 6 can be attached on a part of the vehicle body 2 other than the rear main body case 26, for example, on the front main body case 24, so that the working device 200 can be coupled to the work vehicle 1 at the front of the vehicle body 2.

[0179] For example, when the working device 200 is attached to a location other than the rear of the rear main body case 26, such as the front of the front main body case 24, the aforementioned brackets 26a, 26b, 26d, etc. may be attached to a location prepared for attaching the connecting device 6 at that location.

[0180] Furthermore, the working device 200 may be mounted on, for example, the upper part of the body frame structure 20 of the body 2 of the work vehicle 1 without using the coupling device 6. In this case, the PTO shaft that transmits driving force to the working device 200 may be provided so as to protrude upward from the upper part of the body frame structure 20 (for example, the body central frame 21).

[0181] As described above, the work vehicle 1 is equipped with hydraulic actuators such as the width change cylinder 8 and the vehicle body lifting cylinder 9 provided on the vehicle body 2, and further the steering cylinder 35 provided on the traveling structure 3. Furthermore, the coupling device 6 attached to the vehicle body 2 may also be equipped with hydraulic actuators such as the lift cylinder 61 and attitude adjustment cylinder 63 described above.

[0182] To control the operation of these hydraulic actuators, one or more control valve units 27 are attached to the rear end surface of the bracket 25, the upper end of the lift arm base 26c, or the like, outside the rear main body case 26, as shown in Figures 5, 6, and 12.

[0183] Each control valve unit 27 incorporates a control valve that controls the flow of hydraulic oil between the hydraulic pump 55 and the hydraulic actuator that is the subject of hydraulic control, and also has a port for fluidly connecting the control valve to the hydraulic pump 55, hydraulic actuator, etc. via an oil pipe, etc.

[0184] Note that control valves that hydraulically control different hydraulic actuators may be combined to form one control valve unit 27. Furthermore, the control valve may be provided inside the rear main body case 26, rather than just outside the rear main body case 26 as described above.

[0185] Furthermore, when the control valve of the control valve unit 27 is an electromagnetic valve, the control valve unit 27 may be electrically connected to the control device 15 or the like by an electric wire or the like.

[0186] In addition, instead of the battery 50, an internal combustion engine (engine) may be placed inside the front body case 24, etc., and the engine output may be used to drive the hydraulic pump 55 for operating the hydraulic actuator described above, and the engine output may be transmitted to the PTO shaft 5 to drive the PTO shaft 5.

[0187] As described above, the vehicle body 2 can be "deformed" by the front main body case 24 moving in the longitudinal direction relative to the vehicle body central frame 21 and by the left and right vehicle body side frames 22 moving in the lateral direction relative to the vehicle body central frame 21. The width changing cylinder 8 functions as a vehicle body deformation device (actuator) that deforms the vehicle body 2.

[0188] The vehicle body 2 is also capable of "moving" up and down relative to the left and right traveling structures 3. The vehicle body lifting cylinder 9 functions as a vehicle body moving device (actuator) that moves the vehicle body 2.

[0189] Furthermore, a coupling device 6 can be attached to the vehicle body 2, and the vehicle body 2 can be switched between a state in which the working device 200 is coupled via the coupling device 6 and a state in which the working device 200 is not coupled.

[0190] Hereinafter, the above-described "deformation," "movement," and "switching between a state in which the working device 200 is connected and a state in which it is not connected" of the vehicle body 2 will be collectively referred to as a "change in state" of the vehicle body 2.

[0191] 8 , the entire device for changing the state of the vehicle body 2, including the vehicle body deformation device 80 including the width changing cylinder 8 and battery moving actuator 81, the vehicle body movement device 90 including the vehicle body lifting / lowering cylinder 9, and the coupling device 6 which can connect the working device 200 to the vehicle body and includes the lift cylinder 61 and attitude adjustment cylinder 63 for raising and lowering the working device 200 and adjusting its attitude, is referred to as vehicle body state changing device 100. A control device 15 controls each device included in the vehicle body state changing device 100.

[0192] Next, the structure of the mast mechanism 7 that connects the car body 2 and the left and right traveling structures 3 will be described in detail with reference to Figures 14 to 19, etc.

[0193] The left vehicle body side frame 22L is connected to the running frame 30 of the left running structure 3L via multiple mast mechanisms 7, and the right vehicle body side frame 22R is connected to the running frame 30 of the right running structure 3R via multiple mast mechanisms 7.

[0194] Each mast mechanism 7 has a plurality of mast members 70 combined together so as to be movable relative to one another in the vertical direction, and a restricting portion 74 that prevents relative horizontal movement between the plurality of mast members 70 .

[0195] The multiple mast members 70 of each mast mechanism 7 include a traveling-side mast member 71, a carbody-side mast member 72, and an intermediate mast member 73. The traveling-side mast member 71 is attached (fixed) to each mast mounting plate 30c (30c1, 30c2, 30c3) of the traveling frame 30 shown in Figure 7 and other figures. The carbody-side mast member 72 is attached (fixed) to the vertical rods 22c1 to 22c5 of the carbody side frame 22 shown in Figures 7 and 12 and other figures. The intermediate mast member 73 is interposed between the traveling-side mast member 71 and the carbody-side mast member 72.

[0196] The traveling mast members 71, the vehicle mast members 72, and the intermediate mast members 73 are rectangular plates that are long in the vertical direction and are assembled with both ends substantially aligned in one horizontal direction. Here, as shown in Figure 15, the restricting portion 74 of the mast mechanism 7 is a part or member that has the function of preventing relative movement in the horizontal direction between the traveling mast members 71, the vehicle mast members 72, and the intermediate mast members 73, and maintaining the aforementioned state in which both ends are aligned.

[0197] In this embodiment, a restricting member 75 is provided on each of the vertical rods 22c1 to 22c5 of the vehicle side frame 22. The restricting member 75 is bent in a U-shape in plan view, and the bent portion serves as a restricting portion 74. The vehicle-side mast member 72 is attached and fixed to each restricting member 75 with both ends in that direction aligned with the pair of restricting portions 74. The restricting portions 74 are configured to prevent relative movement in that horizontal direction among the traveling-side mast member 71, vehicle-side mast member 72, and intermediate mast member 73.

[0198] The restricting portion 74 may have any structure as long as it has the function of preventing the plurality of mast members 70 from moving relative to each other in the horizontal direction as described above.

[0199] As shown in Figures 14, 16, etc., the upper and lower ends of the traveling-side mast member 71, the vehicle-side mast member 72, and the intermediate mast member 73 in each mast mechanism 7 are all substantially aligned when the vehicle body 2 is in the normal state (non-raised position).

[0200] 17 to 19, when the carbody 2 rises, the carbody mast members 72 rise together with the carbody 2, and their upper ends protrude above the upper ends of the running mast members 71. As the carbody mast members 72 rise, the upper ends of the intermediate mast members 73 also protrude above the upper ends of the running mast members 71 by an amount smaller than (e.g., half of) the amount of protrusion of the carbody mast members 72.

[0201] While the carbody 2 is rising, the carbody-side mast members 72 and the intermediate mast members 73 are held in a state where both ends in the horizontal direction are aligned with the running-side mast members 71, guided by the regulating parts 74. As a result, even if the carbody 2 moves up and down relative to the left and right running structures 3, the carbody 2 does not shift position in the horizontal direction relative to the left and right running structures 3, and the carbody 2 and the left and right running structures 3 are maintained in a connected state that allows relative movement in the vertical direction.

[0202] The greater the vertical length of the multiple mast members 70, the greater the amount of vertical movement of the vehicle body 2 relative to the left and right traveling structures 3. In other words, the maximum vehicle height, which is the height of the work vehicle 1 when the vehicle body 2 is raised to the maximum height, can be increased.

[0203] If the vertical length of each mast member 70 can be made large, it is possible to configure the mast mechanism 7 using only two mast members 70, namely, the running-side mast member 71 and the vehicle-side mast member 72, which are sufficiently long, excluding the intermediate mast member 73.

[0204] However, while the vertical length of the mast member 70 roughly corresponds to the vertical length of the car body 2 and the running structure 3, there are limitations to the vertical lengths of the car body 2 and the running structure 3 in terms of setting their dimensions. Therefore, there is also a limit to the vertical length of the mast member 70.

[0205] Therefore, in the mast mechanism 7 of this embodiment, the intermediate mast member 73 is interposed between the running-side mast member 71 and the vehicle-side mast member 72, thereby limiting the vertical length of each mast member 70 to an extent that corresponds to the vertical length of the vehicle body 2 and the running structure 3. At the same time, even when the lower end of the vehicle-side mast member 72 is positioned higher than the upper end of the running-side mast member 71, the intermediate mast member 73 is interposed between the running-side mast member 71 and the vehicle-side mast member 72, so the running-side mast member 71 and the vehicle-side mast member 72 are not separated, and the maximum vehicle height of the work vehicle 1 can be increased while maintaining the above-mentioned connection between the vehicle body 2 and the left and right running structures 3.

[0206] Next, the layout of the plurality of mast mechanisms 7 will be described with reference to FIGS. 6, 9, 14 to 19, etc.

[0207] The work vehicle 1 comprises a vehicle body 2 that can move in the vertical direction, a running structure 3 provided on the side of the vehicle body 2, a first member (running side mast member 71) attached to the running structure 3, a second member (vehicle body side mast member 72) attached to the vehicle body 2 that can raise and lower the vehicle body 2 by moving in the vertical direction along the first member (running side mast member 71), and a plurality of mast mechanisms 7 each having a regulating part 74 that regulates movement of the second member (vehicle body side mast member 72) in a direction intersecting the vertical direction, and the plurality of mast mechanisms 7 include a first mast mechanism 7A and a second mast mechanism 7B attached to the running structure 3 and the vehicle body 2 so that the regulating directions of the regulating parts 74 differ from each other.

[0208] That is, the carbody 2 and the traveling structure 3 are connected by a plurality of mast mechanisms 7, and the plurality of mast mechanisms 7 includes a first mast mechanism 7A and a second mast mechanism 7B that are regulated in different directions by the regulating parts 74. The number of mast mechanisms 7 is not limited, and the regulating directions of the first mast mechanism 7A and the second mast mechanism 7B may be in any direction. For example, the regulating direction of the first mast mechanism 7A may be a certain diagonal direction, and the regulating direction of the second mast mechanism 7B may be a diagonal direction that is 90 degrees different from the direction of the first mast mechanism 7A. Note that the angular difference between the regulating directions of the first mast mechanism 7A and the second mast mechanism 7B is not limited to 90 degrees, and any angle difference may be used as long as the regulating directions are different.

[0209] Furthermore, the material, shape, size, etc. of the first member and the second member do not have to be rectangular plate material like the running side mast member 71 or the vehicle side mast member 72, etc., and any material may be used as long as the second member is capable of moving up and down as described above and is suitable for having its movement regulated by the regulating part.

[0210] Furthermore, in the above-described embodiment, the structure of the regulating section 74 is configured by a regulating member 75 having a pair of bent sections arranged opposite each other in the regulating direction, but is not limited to this structure, and any structure is acceptable as long as the second member (car body side mast member 72) attached to the car body 2 can move in the vertical direction relative to the first member (traveling side mast member 71) while being able to regulate the movement of the second member (car body side mast member 72) in the regulating direction.

[0211] In this embodiment, the first mast mechanism 7A is attached to the running structure 3 and the vehicle body 2 so that the regulating portion 74 regulates the movement of the second member (the vehicle body side mast member 72) in the forward / backward direction, and the second mast mechanism 7B is attached to the running structure 3 and the vehicle body 2 so that the regulating portion 74 regulates the movement of the second member (the vehicle body side mast member 72) in the left / right direction.

[0212] In this embodiment, a plurality of mast mechanisms 7 including a first mast mechanism 7A and a second mast mechanism 7B are arranged side by side in the front and rear on each of the left and right sides of the carbody 2. More specifically, a plurality of mast mechanisms 7 including the first mast mechanism 7A and the second mast mechanism 7B are provided at the front, rear, and a middle portion between the front and rear on each of the left and right sides of the carbody 2. More specifically, a plurality of mast mechanisms including the first mast mechanism 7A and the second mast mechanism 7B are provided at the front, rear, and a middle portion between the front and rear on each of the left and right sides of the carbody 2. More specifically, a first mast mechanism 7A is provided at each of the front and rear, and a second mast mechanism 7B is provided at the middle portion between the front and rear.

[0213] That is, in this embodiment, of the multiple mast mechanisms 7 consisting of the front mast mechanism 7F, the middle mast mechanism 7M, and the rear mast mechanism 7R, the front mast mechanism 7F and the rear mast mechanism 7R are defined as the first mast mechanism 7A, whose restricting direction is the fore-and-aft direction, and the middle mast mechanism 7M is defined as the second mast mechanism 7B, whose restricting direction is the left-and-right direction.

[0214] Furthermore, among the multiple mast mechanisms 7 on the left side and the multiple mast mechanisms 7 on the right side, the left side mast mechanisms 7 and the right side mast mechanisms 7 that are arranged at the same position in the fore-and-aft direction of the vehicle are unified into either the first mast mechanism 7A or the second mast mechanism 7B.

[0215] As long as the restricting directions of the left and right mast mechanisms 7 arranged at the same position in the front-rear direction are the same, any restricting direction may be used.

[0216] A specific configuration regarding the layout of the mast mechanism 7 of this embodiment will be described in detail below.

[0217] In the work vehicle 1 according to this embodiment, three mast mechanisms 7 , namely, front, middle and rear, are arranged between the vehicle body side frames 22 and the traveling frame 30 on each of the left and right sides of the vehicle body 2 .

[0218] Hereinafter, the front, middle, and rear mast mechanisms 7 between each vehicle body side frame 22 and the corresponding running frame 30 may be referred to as the front mast mechanism 7F, middle mast mechanism 7M, and rear mast mechanism 7R.

[0219] Furthermore, hereinafter, the front, middle and rear mast mechanisms 7 between the left vehicle body side frame 22L and the left running frame 30L will be referred to as the left front mast mechanism 7FL, the left middle mast mechanism 7ML and the left rear mast mechanism 7RL, and the front, middle and rear mast mechanisms 7 between the right vehicle body side frame 22R and the right running frame 30R will be referred to as the right front mast mechanism 7FR, the right middle mast mechanism 7MR and the right rear mast mechanism 7RR.

[0220] In each mast mechanism 7, the movement of the mast member 70 is restricted in the horizontal direction in which a pair of restricting portions 74 are arranged opposite each other. The horizontal direction in which the movement of the mast member 70 is restricted is referred to as the restricting direction. The front mast mechanism 7F, middle mast mechanism 7M, and rear mast mechanism 7R between each vehicle body side frame 22 and its corresponding running frame 30 include at least two mast mechanisms 7 with different restricting directions.

[0221] In this embodiment, the front mast mechanism 7F, middle mast mechanism 7M, and rear mast mechanism 7R between each vehicle side frame 22 and the running frame 30 on that side include a first mast mechanism 7A whose restricting direction is the fore-and-aft direction, and a second mast mechanism 7B whose restricting direction is the left-and-right direction.

[0222] In other words, the first mast mechanism 7A is a mast mechanism 7 attached to the vehicle body side frame 22 and the running frame 30 with the short sides of the rectangular surface of the mast member 70, which is a plate-shaped member, arranged so that they run along the fore-and-aft direction of the vehicle body 2 and the running structure 3, and the second mast mechanism 7B is a mast mechanism 7 attached to the vehicle body side frame 22 and the running frame 30 with the short sides arranged so that they run along the left-right direction of the vehicle body 2 and the running structure 3.

[0223] Furthermore, in this embodiment, the front mast mechanism 7F and the rear mast mechanism 7R are the first mast mechanism 7A whose restricting direction is the fore-and-aft direction, and the middle mast mechanism 7M is the second mast mechanism 7B whose restricting direction is the left-right direction.

[0224] Here, we will explain the specific mounting structure of the mast mechanism 7 to the carbody 2 and the running structure 3. First, as described above, the vertical rods 30v1, 30v2, and 30v3 at the left and right inner ends of each running frame 30 and the vertical rods 22c1, 22c2, 22c3, 22c4, and 22c5 of each carbody side frame 22 at the left and right outer ends of the carbody 2 are used to support the mast mechanism 7.

[0225] In the front-to-rear direction, the positions of vertical rod 22c2 and vertical rod 30v1 are approximately the same, and vertical rod 22c1 is located in front of vertical rod 22c2 by approximately the width of the mast mechanism 7 in the restricting direction. In addition, in the front-to-rear direction, the positions of vertical rod 22c3 and vertical rod 30v2 are approximately the same. In addition, in the front-to-rear direction, the positions of vertical rod 22c4 and vertical rod 30v3 are approximately the same, and vertical rod 22c5 is located behind vertical rod 22c4 by approximately the width of the mast mechanism 7 in the restricting direction.

[0226] The front mast mechanism 7F is the first mast mechanism 7A whose restriction direction is the fore-and-aft direction. The traveling-side mast members 71 of the front mast mechanism 7F are attached and fixed to the left and right inner surfaces of the mast mounting plates 30c1, which extend forward from the front ends of the left and right inner vertical rods 30v1.

[0227] On the other hand, the vehicle-side mast member 72 of the front mast mechanism 7F is attached to a restricting member 75 fixed to the vertical rods 22c1 and 22c2, with its front and rear edges positioned along restricting portions 74 at the front and rear ends of the restricting member 75, so that its forward and rear movement is restricted. The intermediate mast member 73 is positioned so that it is sandwiched on the left and right sides between the traveling-side mast member 71 and the vehicle-side mast member 72.

[0228] As described above, in the front mast mechanism 7F as the first mast mechanism 7A, in which the mast member 70 is attached to the running frame 30 and the vehicle side frame 22, restricting portions 74 are provided at the front and rear end edges of the mast member 70 so as to extend in the left-right direction.

[0229] The intermediate mast mechanism 7M is the second mast mechanism 7B whose restricted direction is the left-right direction. The traveling-side mast member 71 of the intermediate mast mechanism 7M is attached and fixed to the front side of the mast mounting plate 30c2, which extends inward from the left-right inner ends of the vertical rods 30v2.

[0230] On the other hand, the vehicle-side mast member 72 is attached to a restricting member 75 fixed to the vertical rod 22c3, and its left and right edges are positioned along the restricting portions 74 at the left and right ends of the restricting member 75, so that its left and right movement is restricted. The intermediate mast member 73 is positioned so that it is sandwiched between the traveling-side mast member 71 and the vehicle-side mast member 72 at the front and rear.

[0231] As described above, in the intermediate mast mechanism 7M serving as the second mast mechanism 7B in which the mast member 70 is attached to the running frame 30 and the vehicle side frame 22, restricting portions 74 are provided on the left and right end edges of the mast member 70 so as to extend in the fore-and-aft direction.

[0232] The rear mast mechanism 7R is the first mast mechanism 7A whose restriction direction is the fore-and-aft direction. The traveling-side mast members 71 of the rear mast mechanism 7R are attached and fixed to the left and right inner surfaces of the mast mounting plates 30c3, which extend rearward from the rear ends of the left and right inner vertical rods 30v3.

[0233] On the other hand, the vehicle-side mast member 72 of the rear mast mechanism 7R is attached to a restricting member 75 fixed to the vertical rods 22c4 and 22c5, with its front and rear edges positioned along restricting portions 74 at the front and rear ends of the restricting member 75, so that its forward and rear movement is restricted. The intermediate mast member 73 is positioned so that it is sandwiched on the left and right sides between the traveling-side mast member 71 and the vehicle-side mast member 72.

[0234] As described above, in the rear mast mechanism 7R as the first mast mechanism 7A in which the mast member 70 is attached to the running frame 30 and the vehicle side frame 22, restricting portions 74 are provided at the front and rear end edges of the mast member 70 so as to extend in the left-right direction.

[0235] Each mast mechanism 7 has a structure that has high rigidity in the regulated direction. That is, the first mast mechanism 7A has sufficient rigidity to withstand a strong longitudinal load applied when, for example, the work vehicle 1 accelerates or decelerates, and the second mast mechanism 7B has sufficient rigidity to withstand a strong lateral load applied when, for example, the work vehicle 1 turns.

[0236] Therefore, the front mast mechanism 7F, middle mast mechanism 7M, and rear mast mechanism 7R, which are arranged in a row from front to back, use a mixture of the first mast mechanism 7A, which has the longitudinal direction as its restricting direction, and the second mast mechanism 7B, which has the lateral direction as its restricting direction, so that they have the rigidity to withstand loads applied in both the longitudinal and lateral directions of the work vehicle 1.

[0237] On the other hand, as shown in Figures 15, 16, 18 and 19, in this embodiment, the left front mast mechanism 7FL and the right front mast mechanism 7FR are both first mast mechanisms 7A, the left rear mast mechanism 7RL and the right rear mast mechanism 7RR are both first mast mechanisms 7A, and the left middle mast mechanism 7ML and right middle mast mechanism 7MR are both second mast mechanisms 7B.

[0238] In other words, the left and right mast mechanisms 7 that are in the same position in the fore-and-aft direction are unified as either the first mast mechanism 7A or the second mast mechanism 7B, thereby preventing distortion stress and the like from occurring due to differences in the direction of rigidity between the left and right mast mechanisms 7.

[0239] In addition, in the left-right direction of the work vehicle 1, the front mast mechanism 7F, middle mast mechanism 7M, and rear mast mechanism 7R, which are arranged front to back, are all positioned between the left and right outer ends of the vehicle body 2 and the left and right inner ends of each running structure 3 (running frame 30).

[0240] That is, none of the mast mechanisms 7 has any portion that intrudes into the car body 2 or the running structure 3, and is interposed between the car body 2 and the running structure 3, more specifically, between the running frame 30 and the car body side frame 22. This ensures a wide free space in the left-right direction above the upper frame portion 30u of the running frame 30 of the running structure 3 for mounting various equipment.

[0241] The aforementioned positions of the front, middle, and rear mast mechanisms 7F, 7M, and 7R in the longitudinal direction are merely examples and are not intended to be limiting. Furthermore, the number of mast mechanisms 7 arranged in a row between each vehicle body side frame 22 and its corresponding running frame 30 is not limited to three (front, middle, and rear), but may be, for example, two (front and rear), or four or more.

[0242] Furthermore, the restricting direction of the mast mechanism 7 is not limited to the front-rear direction or the left-right direction as described above. For example, the restricting direction may be a direction oblique to the front-rear direction or the left-right direction.

[0243] Next, the layout of the front wheels 31F and rear wheels 31R in the longitudinal direction of the traveling structure 3 and their positional relationship with the vehicle body 2 will be described with reference to Figures 2, 3, 6, etc.

[0244] The work vehicle 1 is equipped with a running structure 3 provided on each of the left and right sides of the vehicle body 2, and the running structure 3 has a first wheel 31, a second wheel 31 in front of or behind the first wheel 31, and a running frame 30 that supports the axle 31a of the first wheel 31 and the axle 31a of the second wheel 31, and the running frame 30 supports the axle 31a of the first wheel 31 and the axle 31a of the second wheel 31 at a position biased to either the front or rear of the running frame 30.

[0245] In this configuration, either the front wheel 31F or the rear wheel 31R arranged at the front and rear of each traveling structure 3 may be the first wheel 31, and either may be the second wheel 31. In this embodiment, the axle 31a of the front wheel 31F and the axle 31a of the rear wheel 31R are supported at positions biased toward the rear of the traveling frame 30, but this is not limited to this, and the axle 31a of the front wheel 31F and the axle 31a of the rear wheel 31R may be supported at positions biased toward the front of the traveling frame 30.

[0246] In addition, the center between the front and rear ends of the running frame 30 (the part at the midpoint between the front and rear M) is positioned between the first wheel 31 and the second wheel 31, and the distance from the center of the running frame 30 (the part at the midpoint between the front and rear M) to the axle 31a of the first wheel 31 is shorter than the distance from the center of the running frame 30 (the part at the midpoint between the front and rear M) to the axle 31a of the second wheel 31.

[0247] In this embodiment, the front wheel 31F is the first wheel 31, the rear wheel 31R is the second wheel 31, and the distance D1 from the longitudinal midpoint M between the front wheel 31F and the rear wheel 31R to the position A1 of the axle 31a of the front wheel 31F in the longitudinal direction is shorter than the distance D2 from the longitudinal midpoint M to the position A2 of the axle 31a of the rear wheel 31R, but this is not limiting. For example, the rear wheel 31R may be the first wheel 31, and the front wheel 31F may be the second wheel 31, and the distance from the longitudinal midpoint M to the axle 31a of the rear wheel 31R may be shorter than the distance from the longitudinal midpoint M to the axle 31a of the front wheel 31F.

[0248] Furthermore, of the front and rear ends of the running frame 30, the one closer to the first wheel 31 is the first end, and the one closer to the second wheel 31 is the second end, and the distance from the axle 31a of the second wheel 31 to the second end is shorter than the distance from the axle 31a of the first wheel 31 to the first end.

[0249] In this embodiment, the front wheel 31F is the first wheel 31, the rear wheel 31R is the second wheel 31, and the distance D3 from the axle 31a of the rear wheel 31R to the rear end of the running frame 30 in the front-to-rear direction is shorter than the distance D4 from the axle 31a of the front wheel 31F to the front end of the running frame 30, but this is not limited to this. For example, the rear wheel 31R may be the first wheel 31, and the front wheel 31F may be the second wheel 31, and the distance from the axle 31a of the front wheel 31F to the front end of the running frame 30 may be shorter than the distance from the axle 31a of the rear wheel 31R to the rear end of the running frame 30.

[0250] In addition, the second wheels 31 protrude forward or rearward from the second end of the running frame 30, and an attachment area S2 is formed between the left and right second wheels 31 at the front or rear of the vehicle body 2.

[0251] The mounting area S2 is an area where the connecting device 6 for connecting the working device 200 to the vehicle body 2 is disposed when the connecting device 6 is mounted on the vehicle body 2.

[0252] In this embodiment, the front wheel 31F is the first wheel 31 and the rear wheel 31R is the second wheel 31, the rear wheel 31R extends rearward from the rear end of the running frame 30, and an attachment area S2 is formed between the left and right rear wheels 31R at the rear of the vehicle body 2 (rear main body case 26), but this is not limited to this.

[0253] For example, the rear wheel 31R may be the first wheel 31 and the front wheel 31F may be the second wheel 31, with the front wheel 31F extending forward from the front end of the running frame 30, and an attachment area S2 may be formed between the left and right front wheels 31F at the front of the vehicle body 2.

[0254] In addition, the vehicle body 2 can move above the running structure 3, and when the vehicle body 2 descends, the vehicle body 2 is positioned so as to be sandwiched between the left and right running structures 3L, 3R, and the mounting area S2 is formed between the left and right second wheels 31.

[0255] In this embodiment, the front wheels 31F are the first wheels 31, the rear wheels 31R are the second wheels 31, and when the vehicle body 2 is lowered, the mounting area S2 is formed between the left and right rear wheels 31R, but this is not limited to this. For example, the rear wheels 31R may be the first wheels 31, the front wheels 31F may be the second wheels 31, and when the vehicle body 2 is lowered, the mounting area S2 may be formed between the left and right front wheels 31F.

[0256] Of the front and rear ends of the vehicle body 2, the one corresponding to the first end of the travel frame 30 is designated as the third end, and the one corresponding to the second end of the travel frame 30 is designated as the fourth end, with the fourth end of the vehicle body 2 being located closer to the third end than the axles 31 a of the left and right second wheels 31. In addition, a coupling device 6 for coupling the working device 200 to the vehicle body 2 is located within the mounting area S2 and mounted to the fourth end of the vehicle body 2.

[0257] In this embodiment, the first end of the running frame 30 is the front end of the running frame 30, and the corresponding third end of the vehicle body 2 is the front end of the vehicle body 2. The second end of the running frame 30 is the rear end of the running frame 30, and the corresponding fourth end of the vehicle body 2 is the rear end of the vehicle body 2. In other words, the front wheels 31F are the first wheels 31, the rear wheels 31R are the second wheels 31, the rear end of the vehicle body 2 (rear main body case 26) is positioned closer to the front end than the axles 31a of the left and right rear wheels 31R, and the coupling device 6 is attached to the rear end of the vehicle body 2 within an attachment area S2 at the rear of the vehicle body 2.

[0258] For example, the rear wheels 31R may be the first wheels 31, the front wheels 31F may be the second wheels 31, the front end of the vehicle body 2 may be positioned closer to the rear end than the axles 31 a of the left and right front wheels 31F, and the coupling device 6 may be attached to the front end of the vehicle body 2 within the attachment area S2 in front of the vehicle body 2.

[0259] The above configuration will be specifically described below with reference to FIGS. 2, 3, 6, etc.

[0260] The running frame 30 of each running structure 3 is not configured symmetrically in the front and rear directions with respect to the front wheels 31F and rear wheels 31R, and the front wheels 31F and rear wheels 31R are positioned rearward in the running frame 30.

[0261] The longitudinal midpoint M between the front and rear ends of the running frame 30, i.e., the position where the distance from the front end of the running frame 30 is equal to the distance from the rear end, is located between the front wheel 31F and the rear wheel 31R in the longitudinal direction.

[0262] Here, due to the rearward positioning of the front wheel 31F and the rear wheel 31R in the running frame 30 as described above, as shown in Figures 2 and 3, in the fore-and-aft direction, the distance D1 from the fore-and-aft midpoint M to the position A1 of the axle 31a of the front wheel 31F in front of it is shorter than the distance D2 from the fore-and-aft midpoint M to the position A2 of the axle 31a of the rear wheel 31R behind it.

[0263] Furthermore, due to the rearward positioning of the front wheel 31F and the rear wheel 31R as described above, the distance D3 between the rear end E2 of the running frame 30 and the position A2 of the axle 31a of the rear wheel 31R is shorter than the distance D4 between the front end E1 of the running frame 30 and the position A1 of the axle 31a of the front wheel 31F in the longitudinal direction, and in this embodiment, the rear end of the rear wheel 31R protrudes rearward from the rear end of the running frame 30. Furthermore, in this embodiment, the axle 31a of the rear wheel 31R is positioned forward of the rear end of the running frame 30 and rearward of the rear end of the rear main body case 26.

[0264] In relation to the rearward positioning of the front wheels 31F and rear wheels 31R in the traveling frame 30 as described above, the rear main body case 26 disposed at the rear of the vehicle body 2 is positioned forward in the front-to-rear direction relative to the rear wheels 31R of the traveling structure 3, and in this embodiment, the rear end of the rear main body case 26 is positioned forward of the axle 31a of the rear wheels 31R. Note that the rear end of the rear main body case 26 and the axle 31a of the rear wheels 31R may be positioned at approximately the same position in the front-to-rear direction.

[0265] As shown in Figure 5, etc., brackets 26a, 26b for attaching the connecting device 6 as described above are provided at the rear end of the rear main body case 26, and as shown in Figure 6, the space (area) behind the rear main body case 26 serves as an attachment area S2 for placing the connecting device 6 attached to the rear end of the rear main body case 26, i.e., for attaching the working device 200 to the vehicle body 2.

[0266] 2 and 3, the vehicle body 2 is normally lowered and sandwiched between the left and right running structures 3. In this state, the mounting area S2 at the rear of the rear main body case 26 is secured between the axles 31a of the left rear wheel 31RL and the right rear wheel 31RR.

[0267] That is, the mounting area S2 at the rear of the rear main body case 26 is slightly narrower in width at the front because it is sandwiched between the left and right running frames 30L, 30R, but most of it is sandwiched between the left and right rear wheels 31RL, 31RR that extend rearward from the rear ends of the running frames 30, ensuring a wide width equal to the vehicle width of the rear wheel 31R. In other words, the mounting area S2 is a space that widens toward the rear, providing an excellent arrangement space for the coupling device 6 with a three-point link structure.

[0268] Furthermore, since the mounting area S2 is sandwiched (covered) over a wide area in the front-to-rear direction between the left rear wheel 31RL and the right rear wheel 31RR, most of the coupling device 6 arranged in the mounting area S2 is also arranged between the left rear wheel 31RL and the right rear wheel 31RR in the front-to-rear direction. In other words, as shown in Figures 2 and 3, when viewed from the side, most of the coupling device 6 is hidden by the rear wheel 31R, ensuring protection.

[0269] The work vehicle 1 can also be configured so that a coupling device for a work device can be attached to the front of the vehicle body 2, for example, by configuring the front body case 24 so that the coupling device 6 can be attached.

[0270] In this case, it is also possible to support the front wheels 31F and rear wheels 31R biased forward on the running frame 30 so that the left and right front wheels 31F can cover most of the coupling device 6 located in front of the vehicle body 2.

[0271] That is, in this case, it is conceivable to reverse the positional relationship between the front-rear intermediate position M of the traveling frame 30 and the axles 31a of the front wheels 31F and rear wheels 31R from that described above.

[0272] Next, the configuration of the control system in the work vehicle 1 will be described with reference to Figure 8. As shown in Figure 8, the work vehicle 1 is equipped with a positioning device 11. The positioning device 11 is capable of detecting the position of the vehicle body 2 (positioning information including latitude and longitude) using a satellite positioning system (positioning satellite) such as D-GPS, GPS, GLONASS, Beidou, Galileo, or Michibiki. That is, the positioning device 11 receives satellite signals (position of the positioning satellite, transmission time, correction information, etc.) transmitted from the positioning satellites, and detects the position of the vehicle body 2 (e.g., latitude and longitude) based on the satellite signals.

[0273] The positioning device 11 has a receiving device 12 and an inertial measurement unit (IMU) 13. The receiving device 12 has an antenna and the like and is a device that receives satellite signals transmitted from positioning satellites, and is attached to the vehicle body 2. The inertial measurement unit 13 has an acceleration sensor that detects acceleration, a gyro sensor that detects angular velocity, and the like. The inertial measurement unit 13 is attached to the vehicle body 2. The inertial measurement unit 13 can detect the roll angle, pitch angle, yaw angle, etc. of the vehicle body 2. Note that the yaw angle may be detected by installing multiple positioning devices 11.

[0274] As shown in Fig. 8, the work vehicle 1 is equipped with a communication device 14. The communication device 14 includes a communication circuit for communicating via an on-board network and a wireless communication circuit for wireless communication. The wireless communication circuit can communicate directly or indirectly wirelessly with external devices using communication standards such as IEEE 802.11 series Wi-Fi (Wireless Fidelity, registered trademark), BLE (Bluetooth (registered trademark) Low Energy), LPWA (Low Power Wide Area), and LPWAN (Low-Power Wide-Area Network).

[0275] As another example, the communication device 14 may be provided with a communication circuit capable of wirelessly communicating with an external device via, for example, a mobile phone communication network or a data communication network. The external device may be, for example, a personal computer, a smartphone, a tablet computer, a PDA, or a server.

[0276] As shown in Fig. 1 and other figures, the work vehicle 1 is equipped with at least one situation detection device 10. As shown in Fig. 9 and other figures, the work vehicle 1 according to this embodiment is mounted on the upper surface of the flat plate portion 23a of the support member 23 that is attached to the underside of the vehicle body center frame 21 and supports the front main body case 24, and is erected so as to protrude upward from the upper end of the vehicle body center frame 21, passing through open spaces between the left and right main rod members 21a and the front and rear horizontal cylinder members 21b of the vehicle body center frame 21.

[0277] The mounting (supporting) position of the situation detection device 10 on the work vehicle 1 is not limited to the position shown in Figure 1, etc., and it may be supported, for example, on another part of the body frame structure 20 of the body 2, or on the running frame 30 of the running structure 3, etc.

[0278] In addition, multiple situation detection devices 10 may be provided on the work vehicle 1, and, for example, at least one of them may be provided on the vehicle body 2 and at least one other may be provided on the traveling structure 3.

[0279] Furthermore, the situation detection device 10 may be movable. For example, when mounted on the support member 23 as shown in FIG. 1 , the situation detection device 10 may be placed on a rail provided on the support member 23 and be movable along the rail. The direction of movement may be any direction, such as the front-rear direction, the left-right direction, or a direction oblique to the front-rear direction and the left-right direction.

[0280] 8, the situation detection device 10 includes a camera (image capture device) 10a, a sensor 10b, and a calculation unit 10c. In this embodiment, the situation detection device 10 includes both the camera 10a and the sensor 10b, but may include only one of them.

[0281] The camera 10a is configured by a CCD camera equipped with a CCD (Charge Coupled Devices) image sensor, a CMOS camera equipped with a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like.

[0282] It is sufficient that the camera 10a can capture images in at least one direction, including the direction of travel of the work vehicle 1, out of the front, rear, left, and right of the work vehicle 1. Preferably, the camera 10a is configured so that the angle can be changed in the horizontal and vertical directions, for example, in the situation detection device 10, and the image capture direction can be changed both up and down and left and right. In addition, the image capture position can be moved by moving each situation detection device 10 as described above.

[0283] Camera 10a captures images of the surroundings of work vehicle 1 and generates image signals. Calculation unit 10c is made up of a computer or the like that includes a signal processing circuit that processes the generated image signals. The signal processing circuit detects the state of the object (presence or absence of the object, the position of the object, the type of object, the size of the object, etc.) based on the image signals output from camera 10a.

[0284] The sensor 10b is an optical sensor, and is configured, for example, by a LiDAR (Light Detection And Ranging) sensor.

[0285] A LIDAR (laser sensor) emits pulsed measurement light (laser light) millions of times per second from a light source such as a laser diode, and scans the measurement light horizontally or vertically by reflecting it off a rotating mirror, projecting it onto a predetermined detection range (sensing range).

[0286] The LIDAR then receives the measurement light reflected by the object with a light receiving element. The signal processing circuit of the calculation unit 10c detects the state of the object (presence / absence of the object, position of the object, type of the object, size of the object, etc.) based on the light receiving signal output from the LIDAR light receiving element.

[0287] The signal processing circuit detects the distance to the target based on the time from when the LIDAR emits the measurement light to when it receives the reflected light (TOF (Time of Flight) method). Note that the method for detecting the distance by the LIDAR may be a method other than the TOF method.

[0288] The optical sensor 10b may be supplemented with an acoustic sensor to improve detection accuracy.

[0289] The ultrasonic sensor is, for example, composed of an airborne ultrasonic sensor such as a sonar. The airborne ultrasonic sensor transmits measurement waves (ultrasound waves) within a predetermined detection range using a transmitter, and receives the reflected waves from an object using a receiver. A signal processing circuit detects the state of the object (presence or absence of the object, its position, type, size, etc.) based on the signal output from the receiver.

[0290] The signal processing circuit detects the distance to the target based on the time from when the airborne ultrasonic sensor emits a measurement wave until when it receives the reflected wave (TOF (Time of Flight) method). Note that the method for detecting distance using an ultrasonic sensor may be a method other than the TOF method.

[0291] The situation detection device 10 detects the situation around the work vehicle 1 (the vehicle body 2, the left traveling structure 3L, and the right traveling structure 3R). As the situation around the work vehicle 1, the situation detection device 10 detects obstacle information indicating whether there are any obstacles or people in the vicinity of the work vehicle 1 that may come into contact with the work vehicle 1.

[0292] The situation detection device 10 also detects road information, which is information about the roads on which the left and right traveling structures 3 can travel, as the situation around the work vehicle 1. More specifically, it detects road information, which is a value related to the roads on which the traveling structures 3 can travel. The situation detection device 10 detects, for example, the width of the traveling road as road information.

[0293] The width of the travel path detected by the situation detection device 10 is the width of an object that the work vehicle 1 is attempting to straddle between the left traveling structure 3L and the right traveling structure 3R. The situation detection device 10 detects, as the width of the travel path, for example, the width of a ridge on the ground or the width of an obstacle on the ground that obstructs travel.

[0294] Furthermore, the situation detection device 10 detects, for example, the height of the road as road information. The height of the road detected by the situation detection device 10 is the height of an object that the vehicle body 2 is attempting to cross between the left traveling structure 3L and the right traveling structure 3R. The situation detection device 10 detects, for example, the height of ridges on the ground, the height of obstacles on the ground that obstruct traveling, etc. as the height of the road.

[0295] Examples of obstacles that impede travel include grooves or holes formed in the ground, crops planted on the ground, obstacles on the ground (for example, stones or artificial installations), etc. Typically, the situation detection device 10 can detect the height of crops planted on the ground as the height of the obstacle.

[0296] The height of the crop detected by the situation detection device 10 is the height from the ground where the wheels 31 of the traveling structure 3 touch the ground to the top of the crop. For example, if the crop is planted in ridges, the wheels 31 of the traveling structure 3 touch the ground between the ridges rather than on the ridges, and therefore the height of the crop detected by the situation detection device 10 is the "height of the crop itself + height of the ridges."

[0297] The situation detection device 10 may detect the inclination of the ground in the left-right direction as the situation around the work vehicle 1. In this case, the situation detection device 10 can detect the height of the ground on which the left traveling structure 3L travels and the height of the ground on which the right traveling structure 3R travels as the situation around the work vehicle 1. For this reason, the situation detection device 10 may be mounted on each of the left traveling frame 30L and the right traveling frame 30R.

[0298] In this case, for example, an inclination sensor that detects the inclination of the work vehicle 1 (vehicle body 2) in the left-right direction can be used as the situation detection device 10. Alternatively, a camera 10a can be used as the situation detection device 10, and the calculation unit 10c can be configured to detect the inclination of the ground in the left-right direction based on an image captured by the camera 10a.

[0299] Furthermore, the work vehicle 1 is equipped with a detection device that detects the state of the work vehicle 1 itself in addition to the situation detection device 10 that detects the situation around the work vehicle 1 .

[0300] 8 shows, as detection devices for detecting the state of the work vehicle 1 itself, a distance detection device 16 that detects the left-right distance between the left traveling structure 3L and the right traveling structure 3R, which corresponds to the vehicle width, which is the distance between the left and right wheels 31, and a vehicle height detection device 17 that detects the vehicle height, which is the vertical distance from the ground contact points of the wheels 31 to the lowest part of the vehicle body 2. In addition, it is conceivable that the work vehicle 1 may be equipped with a rotation speed detection device that detects the rotation speed of the electric motor 53, a rotation speed detection device that detects the rotation speed of the wheels 31, etc.

[0301] As shown in Fig. 8, the control device 15 provided in the work vehicle 1 is a device that performs various controls of the work vehicle 1. The control device 15 includes a calculation unit (CPU, etc.) and a storage unit (RAM, ROM, etc.). The storage unit may include an external memory provided outside the control device 15. The control device 15 is connected to the various devices and mechanisms shown in Fig. 8 via an in-vehicle LAN (on-board network) such as a CAN (Controller Area Network) or a communication line.

[0302] The control device 15 controls the operations of various devices and mechanisms communicably connected to the control device 15 by the calculation unit executing various control programs stored in the storage unit.

[0303] The control device 15 has control units such as an automatic driving control unit 15A, a distance change control unit 15B, a height change control unit 15C, and a position change control unit 15D, and the functions of these control units are realized by the calculation unit executing a predetermined control program stored in the memory unit.

[0304] The automatic driving control unit 15A of the control device 15 controls the automatic driving of the work vehicle 1. The automatic driving control unit 15A is capable of executing line-type automatic driving control and autonomous-type automatic driving control.

[0305] In line-type automatic driving control, the automatic driving control unit 15A controls the output control inverter 38 of the travel motor 33 of each wheel unit 4 to control the rotation speed of the corresponding wheel 31 so that the work vehicle 1 (car body 2) moves along a predetermined planned driving line, and also controls each control valve in the control valve unit 27 for controlling the extension amount of the steering cylinder 35 of each wheel unit 4 to control the direction (steering angle) of the corresponding wheel 31.

[0306] In autonomous automatic driving control, the automatic driving control unit 15A sets the direction of travel (steering direction) and vehicle speed (velocity) of the vehicle body 2 based on the results of detection of the position of the work vehicle 1 (vehicle body 2) by the positioning device 11, and controls the output control inverter 38 of the travel motor 33 of each wheel unit 4 to control the rotation speed of the corresponding wheel 31 so as to achieve the set steering angle (direction) and vehicle speed, and also controls the control valve unit 27 (control valve) for controlling the extension amount of the steering cylinder 35 of each wheel unit 4 to control the direction (steering angle) of the corresponding wheel 31.

[0307] Note that the line-type automatic driving control and the autonomous-type automatic driving control may be switchable using a switch or the like. Also, the automatic driving control unit 15A may be configured to be able to execute either the line-type automatic driving control or the autonomous-type automatic driving control. Note that the configuration of the automatic driving control unit 15A is not limited to the configuration described above.

[0308] Furthermore, the automatic driving control unit 15A determines, based on obstacle information obtained by sensing (detecting objects) the surroundings of the work vehicle 1 using the situation detection device 10, whether or not the stopped work vehicle 1 should be started, whether or not the moving work vehicle 1 should be stopped, whether or not the direction of travel should be changed by steering, whether or not the drive of the work device 200 during work should be stopped, and / or whether or not the work device 200 should be raised, etc., and controls the output control inverter 38 and steering cylinder 35 of the travel motor 33 in the traveling structure 3, or the output control inverter 54 of the electric motor 53, etc., to realize the determined state.

[0309] As described above, the work vehicle 1 can perform automatic driving (unmanned driving) without an operator on board because the control device 15 includes the automatic driving control unit 15A. Therefore, the work vehicle 1 in the illustrated embodiment does not have a driver's seat where an operator sits.

[0310] However, the work vehicle 1 may be a vehicle that an operator rides in and that performs automatic driving. Alternatively, the work vehicle 1 may be a vehicle that an operator rides in and drives to perform driving. When the work vehicle 1 is a vehicle that an operator rides in, the vehicle body 2 is provided with a driver's seat.

[0311] The distance change control unit 15B of the control device 15 controls the control valve unit 27 (control valve) for controlling the extension and contraction of the width change cylinder 8A and / or width change cylinder 8B as a body deformation device based on information regarding the width of the running path contained in the road information obtained by detection by the situation detection device 10, information regarding the distance between the left running structure 3L and the right running structure 3R detected by the distance detection device 16, etc., so that the distance between the left running structure 3L and the right running structure 3R corresponds to the detected width of the running path, i.e., so that the left and right wheels 31 are correctly positioned between the furrows.

[0312] The height change control section 15C of the control device 15 controls the control valve unit 27 (control valve) for controlling the extension and contraction of the vehicle body lifting cylinder 9 as a vehicle body moving device based on information regarding the height of the driving path contained in the road information obtained by detection by the situation detection device 10 and information regarding the vehicle height detected by the vehicle height detection device 17, so that the vehicle height, which is the vertical distance from the contact point of the wheels 31 to the bottom end of the vehicle body 2, corresponds to the detected height of the driving path, i.e., so that the vehicle body 2 straddles crops, etc. growing on the driving path.

[0313] In addition, the height change control unit 15C of the control device 15 controls the control valve unit 27 (control valve) for controlling the extension and contraction of the left body lifting cylinder 9L and the right body lifting cylinder 9R as body moving devices, in order to adjust the difference in the piston rod extension amounts of the left body lifting cylinder 9L and the right body lifting cylinder 9R, so as to adjust the left and right tilt of the body 2, based on information regarding the left and right inclination of the ground obtained by detection by the situation detection device 10.

[0314] In addition, the position change control unit 15D of the control device 15 measures the slip ratio of the front wheels 31F and rear wheels 31R, for example, from the detection results of a rotation speed detection device that detects the rotation speed of the wheels 31, and if the slip ratio of the front wheels 31F is high, for example, it is possible to cause an external device to display a warning to move the front main body case 24 forward via the communication device 14.

[0315] Furthermore, if the work vehicle 1 is equipped with a battery movement actuator 81 (body deformation device 80) for moving the front body case 24 back and forth, as shown in FIG. 8, the position change control unit 15D operates the battery movement actuator 81 to move the front body case 24 (if the battery movement actuator 81 is a hydraulic actuator, it controls the corresponding control valve).

[0316] The functions and effects of each of the components of the work vehicle 1 described above will be described below.

[0317] (Item A1) A work vehicle 1 comprising a vehicle body 2, wheels 31 provided on the sides of the vehicle body 2, and traveling frames 30 provided on the sides of the vehicle body 2 and supporting the wheels 31, the traveling frames 30 having upper frame portions 30u arranged above the wheels 31, and a space for arranging equipment above the upper frame portions 30u.

[0318] With the above-described configuration, a large space for arranging equipment is secured above the upper frame portion 30u, which is disposed above the wheels 31, of the travel frame 30 provided on the side of the vehicle body 2. In this way, a wide space is created in a location where it is difficult to secure space in a normal vehicle, and this space can be used to arrange equipment such as the travel motors 33 for driving the wheels 31 and the liquid tanks used for spraying. Furthermore, since such equipment can be arranged in this space, space can be secured elsewhere in the vehicle for arranging other equipment, which can contribute to making the entire vehicle more compact and increasing the flexibility in the layout of equipment.

[0319] (Item A2) The wheels 31 include front wheels 31F and rear wheels 31R, and the upper frame portion 30u includes a front portion provided above the front wheels 31F and a rear portion provided above the rear wheels 31R, and the work vehicle 1 described in Item A1 has spaces for arranging the equipment above the front portions and above the rear portions.

[0320] With the above configuration, when the front wheels 31F and rear wheels 31R are provided on the sides of the vehicle body 2, space for arranging equipment can be secured on the sides of the vehicle body 2 above both the front wheels 31F and the rear wheels 31R, thereby achieving the above-mentioned effects.

[0321] (Item A3) The work vehicle 1 according to claim A2, wherein the upper frame portion 30u is provided so as to extend from above the front wheels 31F to above the rear wheels 31R, and the space for arranging equipment is provided in a range extending from above the front wheels 31F to above the rear wheels 31R.

[0322] With the above-described configuration, a continuous, wide space for arranging equipment can be secured on the side of the vehicle body 2, extending from above the front wheel 31F to above the rear wheel 31R, thereby achieving the above-described effects.

[0323] (Item A4) The work vehicle 1 according to any one of Items A1 to A3, wherein the vehicle body 2 is movable in an up-and-down direction relative to the traveling frame 30, and the vehicle body 2 does not have a portion that interferes with the space for arranging equipment during the up-and-down relative movement relative to the traveling frame 30.

[0324] With the above configuration, even in a work vehicle 1 in which the vehicle body 2 is structured to be able to move up and down relative to the running frame 30, the vehicle body 2 does not have any parts that will interfere with the space for equipment placement above the upper frame portion 30u of the running frame 30 due to its up and down movement, so equipment can be placed in that space without worrying about the up and down movement of the vehicle body 2, and the above-mentioned effects can be enjoyed.

[0325] (Item A5) The work vehicle 1 according to any one of items A1 to A4, further comprising a lifting device 9 that moves the vehicle body 2 up and down, on the inner side of the traveling frame 30 in the left-right direction.

[0326] With the above configuration, the lifting device (body lifting cylinder 9) is positioned further left-right inward than the running frame 30, thereby ensuring a large space for arranging equipment at the top of the upper frame portion 30u of the running frame 30 that is not encroached upon by the lifting device (body lifting cylinder 9).

[0327] (Item A6) The work vehicle 1 described in any one of Items A2 to A5, wherein the traveling frame 30 has a lower frame portion 30b below the upper frame portion 30u and between the front wheels 31F and the rear wheels 31R, and a space for arranging equipment is provided between the upper frame portion 30u and the lower frame portion 30b of the traveling frame 30 on the side of the vehicle body 2, between the front wheels 31F and the rear wheels 31R.

[0328] With the above configuration, the traveling frame 30, which provides space for arranging equipment with the upper frame portion 30u, has the lower frame portion 30b between the front wheels 31F and the rear wheels 31R, so that the space formed between the upper frame portion 30u and the lower frame portion 30b can be used for arranging equipment such as the battery 37. In this way, by providing the traveling frame 30 with the above configuration on the side of the vehicle body 2, in addition to the space above the upper frame portion 30u, the space between the front wheels 31F and the rear wheels 31R can be secured as space for arranging equipment, and since equipment can be arranged in this space, space can be secured in other parts of the work vehicle 1 for installing other equipment, for example, which can contribute to making the work vehicle 1 more compact as a whole and improving the flexibility of the equipment layout.

[0329] (Item A7) The work vehicle 1 according to any one of items A2 to A6, wherein the vehicle body 2 is connected to the traveling frame 30 so as to be relatively movable in the up and down direction.

[0330] With the above configuration, the running frame 30 is connected to the vehicle body 2 so that it can move relatively in the vertical direction, but as mentioned above, it does not have any parts that interfere with the space above the upper space section 30u due to vertical movement, so that a space with a sufficiently wide width in the horizontal direction can be secured on at least one side of the vehicle body 2.

[0331] (Item A8) The work vehicle 1 according to Item A7, wherein the vehicle body 2 does not have a portion that vertically overlaps with the upper frame portion 30u of the traveling frame 30 when the vehicle body 2 is disposed at a lowest position within a range of movement relative to the traveling frame 30 in the vertical direction.

[0332] With the above configuration, when the vehicle body 2 is positioned at the lowest position, there is no part that overlaps vertically with the upper frame portion 30u of the running frame 30, so such a part does not narrow the space for arranging equipment above the upper frame portion 30u, and the equipment supported by the vehicle body 2 can be positioned as low as possible within the desired range.

[0333] (Item A9) The work vehicle 1 according to item A7 or A8, wherein the vehicle body 2 is connected to the traveling frame 30 via a mast mechanism 7 that is arranged on the inner side of the traveling frame 30 in the left-right direction.

[0334] With the above configuration, the mast mechanism 7 connects the vehicle body 2 to the traveling frame 30, allowing the vehicle body 2 to move up and down stably without shaking relative to the traveling frame 30. Furthermore, by locating the mast mechanism 7 on the inside of the traveling frame 30 in the left-right direction, a large space for arranging equipment is secured above the upper frame portion 30u of the traveling frame 30, which is not encroached upon by the vehicle body lifting cylinder 9, which serves as the lifting device.

[0335] (Item A10) The work vehicle 1 according to any one of Items A1 to A9, wherein the wheels 31 and the traveling frame 30 are provided on the left and right sides of the vehicle body 2, respectively, and the vehicle body 2 is disposed between the traveling frame 30L on the left side of the vehicle body 2 and the traveling frame 30R on the right side of the vehicle body 2.

[0336] With the above configuration, in a work vehicle 1 having front wheels 31F, rear wheels 31R and running frames 30 on each of the left and right sides, and a body 2 that can move up and down and is arranged between the left running frame 30L and the right running frame 30R, space for installing equipment can be secured above the front wheel 31FL and rear wheel 31RL on the left side of the body 2 and between the front wheel 31FL and rear wheel 31RL, and above the front wheel 31FR and rear wheel 31RR on the right side of the body 2 and between the front wheel 31FR and rear wheel 31RR, thereby providing a work vehicle 1 with a high degree of freedom in the layout of equipment.

[0337] (Item B1) A work vehicle 1 comprising a vehicle body 2 that is movable in an up-down direction, a first device (battery 50) mounted on the vehicle body 2, a second device (electric motor 53, hydraulic pump 55) mounted on the vehicle body 2, left and right traveling structures 3L, 3R provided on the left and right sides of the vehicle body 2, and a movement mechanism 9 that moves the vehicle body 2 in an up-down direction, wherein the vehicle body 2 has a space S1 formed between at least the first device and the second device, and the movement mechanism 9 positions the space S1 at least between the first device and the second device and between the left and right traveling structures 3L, 3R when the vehicle body 2 is in a state where it is lowered to its lowest position, and positions the space S1 at least between the first device and the second device and above the left and right traveling structures 3L, 3R when the vehicle body 2 is in a state where it is raised to its highest position.

[0338] With the above configuration, a space S1 that can be used for multiple purposes, such as for equipment maintenance, is secured in the car body 2. When the car body 2 is normally lowered, the space S1 can be used to cover and protect the equipment installed in the car body 2 with the traveling structure 3, and when the car body 2 is raised, the space S1 is located above the left traveling structure 3L and the right traveling structure 3R, allowing workers to reach into the space S1 for maintenance.

[0339] (Item B2) The work vehicle 1 according to Item B1, wherein the vehicle body 2 has the space S1 behind the first device mounted on a front portion of the vehicle body 2.

[0340] With the above configuration, for example, in a work vehicle 1 having a structure in which a work device 200 is connected to the rear of the vehicle body 2, if a first device which is a heavy object such as a battery 50 is mounted on the front of the vehicle body 2, taking into consideration the weight balance with the work device 200, a space S1 which can be used for multiple purposes can be secured behind the first device.

[0341] (Item B3) The work vehicle 1 according to Item B2, wherein the vehicle body 2 has the space S1 between the first device and the second device mounted on a rear portion of the vehicle body 2.

[0342] With the above configuration, for example, in a work vehicle 1 having a structure in which a working device 200 is connected to the rear of the vehicle body 2, it is necessary to mount a PTO device such as a PTO shaft 5 for driving the working device and a lift cylinder 61 which is hydraulic equipment for raising and lowering the working device 200 at the rear of the vehicle body 2. However, a long space is created in the front and rear directions behind the first equipment mounted on the vehicle body 2, and even if a second equipment such as a PTO device such as a PTO shaft 5 or hydraulic equipment is mounted at the rear of the vehicle body 2, a space S1 can still be secured between the first equipment and the second equipment, and this space can be made into a space S1 that can be used for multiple purposes.

[0343] (Item B4) The work vehicle 1 according to any one of Items B1 to B3, wherein the vehicle body 2 is configured so that the position of the first device can be changed forward or backward, and the vehicle body 2 is switchable between a state in which the space S1 is included and a state in which the space S1 is not included by changing the position of the first device.

[0344] With the above configuration, in a work vehicle 1 whose specifications can be changed, for example, between a specification in which the working device 200 can be connected to the rear of the vehicle body 2 and a specification in which the working device 200 cannot be connected, the first device such as the battery 50 can be placed in an optimal position on the vehicle body 2, taking into consideration weight balance and the like in response to the specification change, and by changing the position, the vehicle body 2 can be switched between a state in which the space portion S1 serving as a multi-purpose space is provided and a state in which it is not provided. In other words, by moving the position of the first device forward on the vehicle body 2, a space portion S1 that can be used as a multi-purpose space can be created.

[0345] (Item C1) A work vehicle 1 including a running structure 3 provided on each of the left and right sides of a vehicle body 2, the running structure 3 having a first wheel 31, a second wheel 31 in front of or behind the first wheel 31, and a running frame 30 supporting the axle 31 a of the first wheel 31 and the axle 31 a of the second wheel 31, the running frame 30 supporting the axle 31 a of the first wheel 31 and the axle 31 a of the second wheel 31 at a position biased to one of the front and rear of the running frame 30.

[0346] By providing a running structure 3 on the side of the vehicle body 2, which has a running frame 30 that supports the front wheels 31F and rear wheels 31R offset to one side, it becomes possible to create space between the end of the vehicle body 2 corresponding to that end of the running frame 30 and the axle 31a of the front wheels 31F and rear wheels 31R that is closer to that end of the running frame 30.This space can be used to attach a connecting device 6 for connecting a working device 200 to the vehicle body 2 at a position protected by the wheels 31.

[0347] (Item C2) The work vehicle 1 described in Item C1, wherein a center M between the front end and the rear end of the traveling frame 30 is disposed between the first wheel 31 and the second wheel 31, and a distance D1 from the center M of the traveling frame 30 to the axle 31 a of the first wheel 31 is shorter than a distance D2 from the center M of the traveling frame 30 to the axle 31 a of the second wheel 31.

[0348] With the above configuration, the front wheels 31F and rear wheels 31R can be supported offset to either the front or rear end of the running frame 30, and it becomes possible to secure an attachment area S2 between the end (rear end) of the vehicle body 2 corresponding to the axle 31a of the second wheel 31 (rear wheel 31R) that is located at a longer distance from the front-to-rear midpoint M, of the axles 31a of the first wheel 31 and second wheel 31, which are the front wheel 31F and rear wheel 31R that are offset to one side from the center of the running frame 30, and the left and right second wheels 31 (left rear wheel 31RL and right rear wheel 31RR).This attachment area S2 can be used to attach a coupling device 6 for connecting a working device 200 to the vehicle body 2 at a position protected by the second wheel 31 (rear wheel 31R).

[0349] (Item C3) The work vehicle 1 described in Item C1 or C2, wherein of the front end and rear end of the traveling frame 30, the one closer to the first wheel 31 is a first end and the one closer to the second wheel 31 is a second end, and a distance D3 from the axle 31 a of the second wheel 31 to the second end is shorter than a distance D4 from the axle 31 a of the first wheel 31 to the first end.

[0350] With the above configuration, the front wheels 31F and rear wheels 31R can be supported offset to either the front or rear end of the running frame 30, which creates the possibility of creating space between the end of the vehicle body 2 corresponding to that end of the running frame 30 and the wheel 31 of the front wheels 31F or rear wheels 31R which is closer to that end of the running frame 30.This space can be used to attach a coupling device 6 for connecting a working device 200 to the vehicle body 2 at a position protected by the wheel 31.

[0351] (Item C4) The work vehicle 1 described in Item C3, wherein the second wheels 31 protrude forward or rearward from the second end of the traveling frame 30, and a mounting area S2 is formed between the left and right second wheels 31 at the front or rear of the vehicle body 2.

[0352] With the above configuration, a mounting area S2 is secured between the left and right second wheels 31 (the left rear wheel 31RL and the right rear wheel 31RR) at the front or rear of the vehicle body 2. The longitudinal distance D3 between the second end (rear end) of the running frame 30 and the axle 31a of the second wheel 31 (rear wheel 31R) is short, and the second wheel 31 (rear wheel 31R) protrudes beyond the second end (rear end) of the running frame 30. Therefore, the mounting area S2 surrounded by the end of the vehicle body 2 and the left and right second wheels 31 (the left rear wheel 31RL and the right rear wheel 31RR) is fan-shaped in a plan view, providing a suitable space for arranging a three-point linkage coupling device 6 or the like.

[0353] (Item C5) The work vehicle 1 described in Item C4, wherein the vehicle body 2 is movable above the running structure 3, and when the vehicle body 2 is lowered, the vehicle body 2 is positioned so as to be sandwiched between the left and right running structures 3L, 3R, and the mounting area S2 is formed between the left and right second wheels 31.

[0354] With the above configuration, in a vehicle body 2 that can move up and down, the mounting area S2 at the front or rear of the vehicle body 2 can be protected by the left and right second wheels 31 (left rear wheel 31RL and right rear wheel 31RR) when the vehicle body 2 is lowered under normal conditions.

[0355] (Item C6) The work vehicle 1 according to Item C4 or C5, wherein a coupling device 6 for coupling a work implement 200 to the vehicle body 2 is disposed within the attachment area S2 and attached to the vehicle body 2.

[0356] With the above configuration, the working device 200 can be connected to the vehicle body 2 via the connecting device 6 provided in the mounting area S2. In addition, the connecting device 6 is covered by the second wheels (rear wheels 31R) on the left and right, thereby enhancing the protection of the connecting device 6.

[0357] (Item C7) The work vehicle 1 described in any one of Items C4 to C6, wherein the front end and rear end of the vehicle body 2 that corresponds to the first end of the running frame 30 is a third end, and the end that corresponds to the second end of the running frame 30 is a fourth end, and the fourth end of the vehicle body 2 is positioned closer to the third end than the axles 31 a of the left and right second wheels 31.

[0358] With the above configuration, a mounting area S2 is secured between the left and right second wheels 31 (the left rear wheel 31RL and the right rear wheel 31RR) at the front or rear of the vehicle body 2. The longitudinal distance between the second end (rear end) of the running frame 30 and the axles 31 a of the second wheels 31 (the left rear wheel 31RL and the right rear wheel 31RR) is short, and the mounting area S2 between the axles 31 a of the left and right second wheels 31 (the left rear wheel 31RL and the right rear wheel 31RR) that spreads out in front of or behind the fourth end (rear end) of the vehicle body 2 has a fan-like shape in a plan view, providing a suitable space for arranging a three-point linkage coupling device 6 or the like.

[0359] (Item C8) The work vehicle 1 according to Item C7, wherein a coupling device 6 for coupling a work implement 200 to the vehicle body 2 is disposed within the attachment area S2 and attached to the fourth end of the vehicle body 2.

[0360] With the above configuration, the working device 200 can be connected to the vehicle body 2 via the connecting device 6 provided in the mounting area S2. Furthermore, the connecting device 6 is covered by the left and right second wheels 31 (the left rear wheel 31RL and the right rear wheel 31RR), which enhances the protection of the connecting device 6.

[0361] (Item D1) A work vehicle 1 comprising: the vehicle body 2 that is movable in an up-and-down direction; a running structure 3 provided on the side of the vehicle body 2; a first member 71 attached to the running structure 3; a second member 72 attached to the vehicle body 2 and that is capable of raising and lowering the vehicle body 2 by moving in an up-and-down direction along the first member 71; and a plurality of mast mechanisms 7 each having a regulating part 74 that regulates movement of the second member 72 in a direction intersecting the up-and-down direction, wherein the plurality of mast mechanisms 7 include a first mast mechanism 7A and a second mast mechanism 7B attached to the running structure 3 and the vehicle body 2 such that the regulating directions of the regulating parts 74 differ from each other.

[0362] With the above configuration, the multiple mast mechanisms 7 include the first mast mechanism 7A and the second mast mechanism 7B, which have different restricting directions for the restricting parts 74, and therefore have good rigidity and durability against loads acting in the restricting directions of both the first mast mechanism 7A and the second mast mechanism 7B. Providing multiple mast mechanisms 7 in this manner prevents loads from being concentrated in one direction on the work vehicle 1, improving the durability of the mast mechanisms 7 as well as various other parts of the work vehicle 1, such as the vehicle body 2 and running structure 3.

[0363] (Item D2) The work vehicle 1 described in Item D1, wherein the first mast mechanism 7A is attached to the traveling structure 3 and the vehicle body 2 so that the regulating portion 74 regulates the movement of the second member 72 in the forward / backward direction, and the second mast mechanism 7B is attached to the traveling structure 3 and the vehicle body 2 so that the regulating portion 74 regulates the movement of the second member 72 in the left / right direction.

[0364] With the above configuration, the first mast mechanism 7A has high rigidity against a load in the fore-and-aft direction of the work vehicle 1 that is applied strongly when the work vehicle 1 suddenly starts or stops. On the other hand, the second mast mechanism 7B has high rigidity against a load in the left-and-right direction of the work vehicle 1 that is applied strongly when the work vehicle 1 makes a sharp turn. By including both the first mast mechanism 7A and the second mast mechanism 7B, the multiple mast mechanisms 7 have good rigidity against loads in both the fore-and-aft direction and the left-and-right direction of the work vehicle 1, and are highly durable.

[0365] (Item D3) The work vehicle 1 according to Item D1 or D2, wherein the plurality of mast mechanisms 7 including the first mast mechanism 7A and the second mast mechanism 7B are arranged side by side in the front-to-rear direction on the left or right side of the vehicle body 2.

[0366] With the above configuration, multiple mast mechanisms 7 including the first mast mechanism 7A and the second mast mechanism 7B are arranged side by side on the left or right side of the vehicle body 2 in the fore-and-aft direction, which is the longitudinal direction of the work vehicle 1, so that the left or right part of the vehicle body 2 in the work vehicle 1 can be made into a structure that is highly durable against the loads described above.

[0367] (Item D4) The work vehicle 1 described in Item D3, wherein the plurality of mast mechanisms 7F, 7M, 7R including the first mast mechanism 7A and the second mast mechanism 7B are provided at the front, rear, and front-to-rear intermediate portion between the front and rear portions on the left or right side of the vehicle body 2.

[0368] With the above configuration, the vehicle body 2 can be firmly supported on the left or right side of the vehicle body 2 so that it can move up and down relative to the running structure 3 by multiple mast mechanisms 7 (front mast mechanism 7F, middle mast mechanism 7M, rear mast mechanism 7R) provided at the front, rear, and middle parts of the front and rear.

[0369] (Item D5) The work vehicle 1 according to item D4, wherein a first mast mechanism 7A is provided at each of the front and rear portions, and a second mast mechanism 7B is provided at the intermediate portion between the front and rear portions.

[0370] With the above-mentioned configuration, the first mast mechanism 7A, which is structured to restrict the fore-and-aft movement of the vehicle-side mast member 72, is provided at the front and rear on the left or right side of the vehicle body 2, thereby ensuring rigidity against loads that are likely to be applied in the direction in which they are applied, and the second mast mechanism 7B, which is structured to restrict the lateral movement of the vehicle-side mast member 72, is provided at the intermediate portion for the front or rear, thereby ensuring rigidity against loads that are likely to be applied in the direction in which they are applied. With these multiple mast mechanisms 7, the vehicle body 2 can be firmly supported on the left or right side of the vehicle body 2 relative to the running structure 3, allowing it to move up and down.

[0371] (Item D6) The work vehicle 1 according to Item D1 or D2, wherein the plurality of mast mechanisms 7 including the first mast mechanism 7A and the second mast mechanism 7B are arranged side by side in the front-to-rear direction on each of the left and right sides of the vehicle body 2.

[0372] With the above configuration, multiple mast mechanisms 7 including the first mast mechanism 7A and the second mast mechanism 7B are arranged side by side on both the left and right sides of the vehicle body 2 in the fore-and-aft direction, which is the longitudinal direction of the work vehicle 1, so that the left and right portions of the vehicle body 2 in the work vehicle 1 can be made into a structure that is highly durable against the loads described above.

[0373] (Item D7) The work vehicle 1 described in Item D6, wherein the plurality of mast mechanisms 7F, 7M, 7R including the first mast mechanism 7A and the second mast mechanism 7B are provided at the front, rear, and front-to-rear intermediate portions between the front and rear portions on each of the left and right sides of the vehicle body 2.

[0374] With the above configuration, the vehicle body 2 can be firmly supported so that it can move up and down relative to the running structure 3 by multiple mast mechanisms 7 (front mast mechanism 7F, middle mast mechanism 7M, rear mast mechanism 7R) provided on both the left and right sides of the vehicle body 2 at the front, rear, and middle parts of the front and rear.

[0375] (Item D8) The work vehicle 1 according to item D7, wherein the first mast mechanism 7A is provided at each of the front and rear portions, and the second mast mechanism 7B is provided at the front-rear intermediate portion.

[0376] With the above configuration, by providing the first mast mechanisms 7A at the front and rear of both the left and right sides of the carbody 2, rigidity against loads that tend to be applied to the front and rear sections is ensured, and by providing the second mast mechanisms 7B at the intermediate section for the front and rear, rigidity against loads that tend to be applied to the intermediate section for the front and rear is ensured. These multiple mast mechanisms 7 (front mast mechanisms 7F, middle mast mechanisms 7M, rear mast mechanisms 7R) enable the carbody 2 to be firmly supported on both the left and right sides of the carbody 2 so that it can move up and down relative to the running structure 3.

[0377] (Item D9) A work vehicle 1 as described in Item D6, wherein, of the plurality of mast mechanisms 7 on the left side and the plurality of mast mechanisms 7 on the right side, the left side mast mechanism 7 and the right side mast mechanism 7 that are arranged at the same position in the fore-and-aft direction of the work vehicle 1 are unified into either the first mast mechanism 7A or the second mast mechanism 7B.

[0378] The above configuration eliminates distortions and the like caused by different directions in which rigidity against loads can be ensured on the left and right sides of the vehicle body 2, thereby increasing the durability of various parts across the left and right directions of the work vehicle 1.

[0379] (Item D10) The work vehicle 1 according to any one of Items D1 to D6, wherein the traveling structure 3 has an inner surface facing a side surface of the vehicle body 2, and the first member 71 is attached to the inner surface of the traveling structure 3.

[0380] With the above configuration, as the vehicle body 2 rises, the vehicle body side mast member 72 and the regulating portion 74 move upward relative to the running side mast member 71, which may result in them being exposed above the running structure 3. However, regardless of the upward movement of the vehicle body side mast member 72, the running side mast member 71 remains fixed to the inner surface of the running structure 3, so it is not exposed to the outside. This ensures the protection of the mast mechanism 7 itself, and also ensures that a large space is secured above the running structure 3 that is not invaded by the mast mechanism 7 when the vehicle body 2 is raised. By using this space for arranging equipment, it is possible to increase the freedom of layout of equipment throughout the work vehicle 1.

[0381] Although the embodiments of the present invention have been described above, the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0382] REFERENCE SIGNS LIST 1 Work vehicle 2 Vehicle body 3 Traveling structure 3L Left traveling structure 3R Right traveling structure 7 Mast mechanism 7A First mast mechanism 7B Second mast mechanism 20 Vehicle body frame structure 22 Vehicle body side frame 30 Traveling frame 30L Left traveling frame 30R Right traveling frame 70 Mast member 71 Vehicle body side mast member 72 Traveling side mast member 73 Intermediate mast member 74 Restricting portion 75 Restricting member

Claims

1. A work vehicle comprising: a vehicle body movable in the vertical direction; a traveling structure provided on the side of the vehicle body; a first member attached to the traveling structure; a second member attached to the vehicle body and movable in the vertical direction along the first member to raise and lower the vehicle body; and a plurality of mast mechanisms each having a restricting portion that restricts the movement of the second member in a direction intersecting the vertical direction, wherein the plurality of mast mechanisms include a first mast mechanism and a second mast mechanism attached to the traveling structure and the vehicle body such that the restricting directions of the respective restricting portions thereof are different from each other.

2. The work vehicle according to claim 1, wherein the first mast mechanism is attached to the traveling structure and the vehicle body such that the restricting portion restricts the movement of the second member in the front-rear direction, and the second mast mechanism is attached to the traveling structure and the vehicle body such that the restricting portion restricts the movement of the second member in the left-right direction.

3. The work vehicle according to claim 1 or 2, wherein on the left side or the right side of the vehicle body, the plurality of mast mechanisms including the first mast mechanism and the second mast mechanism are arranged side by side in the front-rear direction.

4. The work vehicle according to claim 3, wherein the plurality of mast mechanisms including the first mast mechanism and the second mast mechanism are provided at a front portion, a rear portion, and a front-rear intermediate portion between the front portion and the rear portion on the left side or the right side of the vehicle body.

5. The work vehicle according to claim 4, wherein the first mast mechanism is provided at each of the front portion and the rear portion, and the second mast mechanism is provided at the front-rear intermediate portion.

6. The work vehicle according to claim 1 or 2, wherein on each of the left side and the right side of the vehicle body, the plurality of mast mechanisms including the first mast mechanism and the second mast mechanism are arranged side by side in the front-rear direction.

7. The work vehicle according to claim 6, wherein the plurality of mast mechanisms including the first mast mechanism and the second mast mechanism are provided at a front portion, a rear portion, and a front-rear intermediate portion between the front portion and the rear portion on each of the left side and the right side of the vehicle body.

8. The work vehicle according to claim 7, wherein the first mast mechanism is provided at each of the front portion and the rear portion, and the second mast mechanism is provided at the front-rear intermediate portion.

9. The working vehicle according to claim 6, wherein among the plurality of mast mechanisms on the left side and the plurality of mast mechanisms on the right side, the left mast mechanism and the right mast mechanism disposed at the same position in the longitudinal direction of the vehicle are unified by one of the first mast mechanism and the second mast mechanism.

10. The working vehicle according to claim 1, wherein the traveling structure has an inner surface facing the side surface of the vehicle body, and the first member is attached to the inner surface of the traveling structure.

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