Work vehicle

Abstract

To provide a work vehicle in which a space for multiuse is secured in a vehicle body.SOLUTION: A work vehicle 1 comprises: a vertically movable vehicle body 2; first equipment and second equipment mounted on the vehicle body 2; left and right traveling structures 3L, 3R provided on the left side and on the right side of the vehicle body 2; and a movement mechanism 9 moving the vehicle body 2 vertically. The vehicle body 2 has at least a space portion S1 formed between the first equipment and the second equipment. A cylinder 9 for vertically moving a vehicle body 2 locates the space portion S1 at least between the first equipment and the second equipment and between the left traveling structure 3L and the right traveling structure 3R while the vehicle body 2 lowers most, and locates the space portion S1 at least between the first equipment and the second equipment and above the left traveling structure 3L and the right traveling structure 3R while the vehicle body 2 is raised most.SELECTED DRAWING: Figure 13

Description

Technical Field

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

Background Art

[0002] In recent years, regarding agricultural work and the like using work vehicles, the work form has shifted from the manual operation form in which an operator gets into the vehicle to a remote control type work form in which the operator remotely controls the vehicle using a terminal device or the like, or an autonomous driving type work form in which the vehicle is driven along a route set in the field by GPS, etc., and the work form is shifting to a work form in which the work vehicle runs unmanned.

[0003] Therefore, regarding the form of the vehicle as well, it is conceivable to change from the conventional tractor type equipped with a driver's seat to a more convenient form for carrying out the intended work such as agricultural work. For example, when performing spraying work with a sprayer attached to the vehicle, it is convenient if a large-capacity spray agent tank can be mounted on the vehicle, which also leads to an improvement in work efficiency.

[0004] For example, Patent Document 1 discloses an agricultural work form in which a spray agent tank and a sprayer are placed on a plate bridged between a plurality of autonomously driving work vehicles, and the work vehicle transports these while performing spraying work with the sprayer.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Here, when using an unmanned work vehicle comprising a vehicle body and left and right traveling structures having wheels or the like arranged on both left and right sides of the vehicle body, for example, when the vehicle body is placed in a state of being spanned across ridges, and the left and right traveling structures are arranged on both left and right sides of the ridges for agricultural work, it is conceivable to make the vehicle body movable, for example, in the vertical direction corresponding to crops or the like growing on the ridges. On the other hand, it is conceivable to mount various devices such as heavy objects like batteries and hydraulic devices on this vehicle body.

[0007] Among the various devices mounted on the vehicle body in this way, if a space portion of a certain width is secured between the devices, it is expected to improve convenience such as making it easier for workers to access for maintenance of the devices.

Means for Solving the Problem

[0008] A work vehicle according to an embodiment of the present invention includes a vehicle body movable in the vertical direction, a first device mounted on the vehicle body, a second device mounted on the vehicle body, left and right traveling structures provided on the left and right sides of the vehicle body, and a moving mechanism for moving the vehicle body in the vertical direction. The vehicle body has a space portion formed at least between the first device and the second device. The moving mechanism positions the space portion between at least the first device and the second device and between the left and right traveling structures in a state where the vehicle body is at its lowest descent, and positions the space portion between at least the first device and the second device and above the left and right traveling structures in a state where the vehicle body is at its highest ascent.

[0009] The vehicle body may have the space portion behind the first device mounted at the front of the vehicle body.

[0010] The vehicle body may have the space portion between the first device and a second device mounted at the rear of the vehicle body.

[0011] The vehicle body may be configured such that the first device can be repositioned longitudinally. The vehicle body may be switchable between a state with the space portion and a state without the space portion by the repositioning of the first device.

Advantages of the Invention

[0012] According to the work vehicle of the present invention, a space portion that can be used for various purposes is secured between the first device and the second device mounted on the vehicle body.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

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Figure 7

Figure 8

Figure 9

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Figure 12

Figure 13

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Figure 15

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Figure 18

Figure 19

Mode for Carrying Out the Invention

[0014] Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the work vehicle 1 according to the present invention will be described.

[0015] In the following description, the direction indicated by the arrow X1 in FIG. 1 is the front, the direction indicated by the arrow X2 is the rear, the direction indicated by the arrow Y1 is the left, the direction indicated by the arrow Y2 is the right, the direction indicated by the arrow Z1 is the upward, and the direction indicated by the arrow Z2 is the downward.

[0016] Examples of the work performed by the work vehicle 1 include, but are not limited to, work related to agriculture, work related to industry (civil engineering, construction, etc.), work related to transportation, etc. In the case of the preferred embodiment of the present invention, the work performed by the work vehicle 1 is work related to agriculture (farming work). Hereinafter, the case where the work performed by the work vehicle 1 is farming work will be described as an example. In this case, the work vehicle 1 is an agricultural work vehicle.

[0017] As shown in FIGS. 1 to 6 and the like, 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 the traveling structure 3.

[0018] As shown in FIG. 5 and the like, the vehicle body 2 is provided at its rear end with a PTO shaft 5 for transmitting driving force to a working device (implement) 200 (see FIGS. 2 and 3) connected to the work vehicle 1, and a connecting device 6 for connecting the working device 200 to the work vehicle 1 can be attached to the rear end portion.

[0019] Regarding the structure of the connecting device 6, various structures can be considered corresponding to the type of the working device (implement) 200 and the like. In the present embodiment, it is assumed to be a three-point link mechanism having a pair of left and right lower links 6a and one top link 6b.

[0020] Note that the working device 200 may be connected to a portion other than the rear end portion (for example, the front end portion) of the vehicle body 2 of the work vehicle 1 and be capable of receiving driving force from the work vehicle 1.

[0021] The structure of each traveling structure 3 will be described with reference to FIGS. 1 to 7 and the like. Each traveling structure 3 has a traveling frame 30 and a pair of wheel units 4. The pair of wheel units 4 includes a front wheel unit 4F supported at the front portion of the traveling frame 30 and a rear wheel unit 4R supported at the rear portion of the traveling frame 30.

[0022] 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 the front wheel 31F, and the wheel 31 of the rear wheel unit 4R is the rear wheel 31R.

[0023] As can be seen from the front view of FIG. 4, the rear view of FIG. 5, the plan view of FIG. 6, etc., in the left-right direction, the positions of the outer ends of the traveling frame 30 and the outer ends of the wheels 31 (front wheel 31F and rear wheel 31R) are substantially the same.

[0024] The front wheel 31F and the rear wheel 31R have the same diameter or substantially the same diameter. Note that the front wheel 31F and the rear wheel 31R may have different diameters. Also, at least one of the front wheel 31F and the rear wheel 31R may be a driving wheel (driving sprocket) of a crawler type traveling device.

[0025] 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 part of the left running frame 30L is the left front wheel unit 4FL having the left front wheel 31FL, and the rear wheel unit 4R supported at the rear part of the left running frame 30L is the left rear wheel unit 4RL that pivotally supports the left rear wheel 31RL.

[0026] 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 part of the right running frame 30R is the right front wheel unit 4FR that pivotally supports the right front wheel 31FR, and the rear wheel unit 4R supported at the rear part of the right running frame 30R is the right rear wheel unit 4RR that pivotally supports the right rear wheel 31RR.

[0027] Each wheel drive case 32 of the wheel unit 4 has a motor housing portion 32a, a transmission mechanism housing portion 32b, and a rotating cylinder portion 32c. The motor housing portion 32a and the transmission mechanism housing portion 32b are integrally formed at the upper part of the wheel drive case 32, and the rotating cylinder portion 32c extends vertically downward from the transmission mechanism housing portion 32b that extends laterally from the motor housing portion 32a. The rotating cylinder portion 32c is connected to the transmission mechanism housing portion 32b so as to be relatively rotatable.

[0028] The running motor 33 (see FIG. 8) is housed in the motor housing portion 32a, and a vertical transmission shaft 34 having an axis in the vertical (up and down) direction is rotatably supported around the axis in the rotating cylinder portion 32c. The central axis (axle) 31a of the wheel 31 is inserted and supported at the lower end portion of the rotating cylinder portion 32c. In other words, the axle 31a protrudes outward to the left and right from the lower portion of the rotating cylinder portion 32c of the wheel drive case 32, and the wheel 31 provided around this axle 31a is disposed on the left and right outer sides of the rotating cylinder portion 32c.

[0029] In addition, a transmission mechanism having bevel gears, endless belts, etc. that interlock and link the output shaft of the traveling motor 33 and the upper part of the vertical transmission shaft 34 is housed in the transmission mechanism housing part 32b. Further, a transmission mechanism having bevel gears, etc. that interlock and link the lower part of the vertical transmission shaft 34 and the axle 31a of the wheel 31 is housed in the lower part of the rotating cylinder part 32c.

[0030] It shall be noted that the traveling frame 30 may be described as supporting the axle 31a of the wheel 31 on the grounds that the traveling frame 30 supports the wheel drive case 32 that pivotally supports the axle 31a of the wheel 31.

[0031] With the above configuration, within the wheel drive case 32, the output of the traveling motor 33 is transmitted to the wheel 31 via the vertical transmission shaft 34, thereby driving the wheel 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 drive wheels driven by the output of the traveling motor 33 each has individually.

[0032] The rotating cylinder part 32c of each wheel drive case 32 extends in the vertical direction as described above, and the vertical axis center of the vertical transmission shaft 34 and the axis center of the rotating cylinder part 32c coincide. The upper part of the wheel drive case 32 as the motor housing part 32a and the transmission mechanism housing part 32b is attached to and fixed to the traveling frame 30, while the rotating cylinder part 32c is rotatable around the vertical axis center with respect to the upper part.

[0033] A pair of front and rear steering cylinders 35 are supported by the traveling frame 30. The steering cylinder 35 supported by the front part of the traveling frame 30 is the front steering cylinder 35F. 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 part of the rotating cylinder part 32c of the wheel drive case 32 of the front wheel unit 4F.

[0034] The steering cylinder 35 supported at the rear part of the traveling frame 30 is the rear steering cylinder 35R. One end (cylinder bottom) of the rear steering cylinder 35R is connected to the traveling frame 30, and the other end (piston rod head) of the rear steering cylinder 35R is connected to the outer part of the rotating cylinder portion 32c of the wheel drive case 32 of the rear wheel unit 4R.

[0035] The rotating cylinder portion 32c of each wheel drive case 32 rotates about its vertical axis center by the expansion and contraction of the steering cylinder 35 while supporting the wheel 31. That is, the wheel 31 is a drive wheel driven by the traveling motor 33 as described above, and is a steering wheel that can rotate relative to the traveling frame 30 in the left - right direction, that is, can change the angle in the left - right direction.

[0036] 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 to control the output rotation speed and output rotation direction of the corresponding traveling motor 33.

[0037] In the block diagram of FIG. 8, only the combination of the traveling motor 33 and the inverter 38 for one wheel unit 4 is shown. Here, the wheel unit 4 represents each of the four wheel units 4FL, 4FR, 4RL, and 4RR. The control device 15 controls the inverters 38 for each individual wheel unit 4 to individually control the rotation speed and rotation direction of each wheel 31.

[0038] As shown in FIGS. 1 to 3, etc., the traveling frame 30 of each traveling 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.

[0039] Inside the battery case 36, a battery (side battery) 37 that supplies power to the drive motors 33 of the front wheel unit 4F and the rear wheel unit 4R is housed. Also, on the front side of the battery case 36, an inverter 38 for the front wheel unit 4F and on the rear side of the battery case 36, an inverter 38 for the rear wheel unit 4R are supported by the traveling frame 30. Note that the arrangement of the inverter 38 is not limited to the illustrated arrangement and may be provided inside the battery case 36, for example.

[0040] In each traveling structure 3 (left traveling structure 3L, right traveling structure 3R), the front wheel unit 4L and the rear wheel unit 4R drive their respective drive motors 33 with electric power supplied from a battery (center battery 50 and / or side battery 37) provided in the work vehicle 1.

[0041] The inverter 38 provided for each wheel unit 4 converts the direct current from the batteries 37, 50 into an alternating current and applies the alternating current to the drive motor 33 of the wheel unit 4 at a set voltage and / or frequency.

[0042] As shown in FIG. 8, by controlling the set values of the voltage and / or frequency of each inverter 38 by the control device 15, the output rotational speed and / or torque of the drive motor 33 are controlled, whereby the rotational speed and / or torque of the wheel 31 of the wheel unit 4 are controlled.

[0043] Also, each steering cylinder 35 is a hydraulic cylinder (hydraulic actuator) and expands and contracts with hydraulic oil discharged from a hydraulic pump 55 provided in the vehicle body 2 and supplied via a corresponding control valve.

[0044] As shown in FIG. 8, by controlling the position of the corresponding control valve (spool) in the control valve unit 27 by the control device 15, the extension amount of its piston rod is controlled, and the wheel 31 of the wheel unit 4 is steered.

[0045] Note that, similar to the aforementioned traveling motor 33 and inverter 38, only one steering cylinder 35 is shown in the block diagram of FIG. 8. However, this steering cylinder 35 is meant to be the one provided in each wheel unit 4. The control device 15 controls the control valve for the steering cylinder 35 for each individual wheel unit 4 to individually control the steering angle (left and right turning angles) of each wheel 31.

[0046] Note that each steering cylinder 35 may be configured other than a hydraulic cylinder, such as an air cylinder or a hydraulic cylinder. Also, the actuator for steering the wheel 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.

[0047] Here, the structure of the traveling frame 30 will be described with reference to FIGS. 1 to 7 and the like.

[0048] 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 to support the wheels 31. The traveling frame 30 has an upper frame portion 30u disposed above the wheels 31, and has a space for equipment arrangement above the upper frame portion 30u.

[0049] In the present embodiment, as will be described later, a space for equipment arrangement is provided above the upper frame portions 30u of the left and right traveling frames 30 above the front wheels 31F and the rear wheels 31R. However, in at least one traveling frame 30 (for example, one of the left and right traveling frames 30L and 30R), a space for equipment arrangement may be provided above the upper frame portion 31u above at least one wheel 31 (for example, one of the front wheels 31F and the rear wheels 31R).

[0050] The wheels 31 include front wheels 31F and rear wheels 31R. 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 a space for equipment arrangement above the upper portion of the front portion and the upper portion of the rear portion.

[0051] In this embodiment, a flat surface is formed flush from the front end to the rear end of the upper frame portion 30u of the traveling frame 30, including the front portion above the front wheel 31F and the rear portion above the rear wheel 31R, and this serves as a space for equipment arrangement. That is, the upper frame portion 30u is provided so as to extend from above the front wheel 31F to above the rear wheel 31R, and the space for equipment arrangement is provided in a range extending from above the front wheel 31F to above the rear wheel 31R. However, it is sufficient that the space for equipment arrangement is provided at least in the front portion and the rear portion of the upper frame portion 30u. For example, the portion between the front portion and the rear portion may be separated to form a gap, or it may not be a flat surface that can be utilized as the space for equipment arrangement.

[0052] The vehicle body 2 is capable of moving relative to the traveling frame 30 in the vertical direction, but does not have a portion that interferes with the space for equipment arrangement during the relative movement in the vertical direction with respect to the traveling frame 30. As described above, the space for equipment arrangement may be provided above one wheel 31. In this case, the vehicle body 2 does not need to have a portion that interferes with the equipment space above the wheel 31.

[0053] The work vehicle 1 includes a lifting device for moving the vehicle body 2 in the vertical direction on the inner side in the left - right direction of the traveling frame 30, that is, on the vehicle body 2 side.

[0054] This configuration is also one that does not have a portion that interferes with the equipment placement space above the upper frame portion 30u of the traveling frame 30 while the vehicle body 2 is moving up and down. If, hypothetically, the lifting device is not inside the left and right sides of the traveling frame 30, but is between the left end and the right end of the traveling frame 30, that is, within the left and right width, and has a structure where the lifting device expands and contracts vertically, then when the vehicle body 2 is lifted, it may protrude above the traveling frame 30 and interfere with the equipment arranged in the equipment placement space provided in the upper frame portion 30u. Even if the lifting device is provided on the left and right outer sides of the traveling frame 30, it will not have a portion that interferes with the equipment placement space while the vehicle body 2 is moving up and down. However, by arranging it on the left and right inner sides of the traveling frame 30, the connection with the vehicle body 2 is easy, and the compactness of the working vehicle 1 in the left and right width direction can be ensured.

[0055] In this embodiment, the lifting device is the vehicle body lifting cylinder 9, which is a hydraulic actuator hanging down from above the vehicle body side frame 22 forming the left and right ends of the vehicle body 2 as described later. However, as the lifting device, any device such as one using an electric motor may be used. Also, it does not have to be provided inside the vehicle body 2, and it may be on the left and right outer sides from the vehicle body 2 or on the left and right inner sides from the traveling frame 30.

[0056] Also, the traveling frame 30 has a lower frame portion 30b between the front wheels 31F and the rear wheels 31R below the upper frame portion 30u, and has an equipment placement space between the upper frame portion 30u and the lower frame portion 30b of the traveling frame 30 between the front wheels 31F and the rear wheels 31R on the side of the vehicle body 2.

[0057] In this embodiment, an equipment placement (side battery 37 placement) space between the upper frame portion 30u and the lower frame portion 30b is provided in each of the left and right traveling frames 30L and 30R. However, only one of the left and right traveling frames 30L and 30R may be configured in this way.

[0058] Further, as will be described later, the vehicle body 2 is connected to the running frame 30 so as to be relatively movable in the vertical direction. However, when the vehicle body 2 is disposed at the lowest position within the vertical relative movement range with respect to the running frame 30, it does not have a portion that vertically overlaps with the upper frame portion 30u of the running frame 30. For example, if a portion that projects outward in the left and right directions is provided at the upper portion of the vehicle body 2, there is a possibility that the portion vertically overlaps with the upper frame portion 30u when the vehicle body 2 is at the lowest position. However, in the present embodiment, the vehicle body 2 does not have such a projecting portion.

[0059] That is, the configuration in which the vehicle body 2 and the running frame 30 do not have a vertically overlapping portion as described above is also a configuration in which the vehicle body 2 does not have a portion that interferes with the equipment arrangement space above the upper frame portion 30u of the running frame 30 during vertical movement. If the vehicle body 2 has a portion that vertically overlaps with the upper frame portion 30u of the running frame 30 when the vehicle body 2 is at the lowest position, the portion may interfere with the equipment arranged in the equipment arrangement space provided in the upper frame portion 30u.

[0060] Also, the vehicle body 2 is connected to the running frame 30 via a mast mechanism 7 disposed inside the running frame 30 in the left-right direction. The mast mechanism 7 supports the vehicle body 2 that moves up and down by the operation of the lifting device described above. Similar to the above-described lifting device, the mast mechanism 7 is also disposed inside the running frame 30 in the left-right direction, so that the vehicle body 2 does not have a portion that interferes with the equipment arrangement space above the upper frame portion 30u of the running frame 30 during vertical movement.

[0061] With the above configuration, regardless of the lifting of the vehicle body 2, interference between the equipment on the vehicle body 2 side and the equipment disposed on the upper frame portion 30u of the running frame 30 is avoided, and a wide equipment arrangement space is always secured on the running frame 30, and it is possible to mount equipment having a considerably large volume.

[0062] Note that the work vehicle 1 is provided with wheels 31 and a traveling frame 30 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.

[0063] Hereinafter, the specific structure of the traveling frame 30 will be described in detail. The traveling frame 30 has an upper frame portion 30u that constitutes its upper end portion. The upper frame portion 30u is formed of a ladder-shaped portion including a pair of left and right main rod members 30u1 and 30u2 extending in the front-rear direction, which are inner and outer main rod members, respectively, and a plurality of cross rod members 30u3 extending in the left-right direction so as to connect the inner main rod member 30u1 and the outer main rod member 30u2.

[0064] As can be seen in the plan view of FIG. 6 and the like, the front end of the upper frame portion 30u is located in front of the front end of the front wheel 31F, and the rear end of the upper frame portion 30u is disposed between the rear end of the rear wheel 31R and the axle 31a of the rear wheel 31R.

[0065] The inner main rod member 30u1 defines the left and right inner ends of the traveling frame 30, and the outer main rod member 30u2 defines the left and right outer ends of the traveling frame 30. That is, in the upper frame portion 30u of the left traveling frame 30L of the left traveling structure 3L, the inner main rod member 30u1 is disposed on the right side and the outer main rod member 30u2 is disposed on the left side, and in the upper frame portion 30u of the right traveling frame 30R of the right traveling structure 3R, the inner main rod member 30u1 is disposed on the left side and the outer main rod member 30u2 is disposed on the right side.

[0066] The front ends of the inner main rod member 30u1 and the outer main rod member 30u2 define the front end of the traveling 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 traveling frame 30. That is, the upper frame portion 30u is configured to be long in the front-rear direction from the front end to the rear end of the traveling frame 30.

[0067] Further, the left and right width of the upper frame portion 30u, which is the sum of the lengths of the cross rod members 30u3 extending in the left-right direction and the left and right widths of the inner main rod member 30u1 and the outer main rod member 30u2, defines the left and right width of the traveling frame 30.

[0068] The left - right width of this traveling frame 30 ensures sufficient length so that the left - right ends of the wheel units 4 do not protrude outward in the left - right direction beyond the left - right ends of the traveling frame 30. Therefore, components, members included in the traveling structure 3, or devices provided on the traveling structure 3 do not protrude from the traveling structure 3 and enter the vehicle body 2 arranged inside the left - right sides of the traveling structure 3 at all, so that the up - and - down movement of the vehicle body 2 relative to the traveling structure 3 described later is not hindered.

[0069] Due to the upper frame part 30u with such a configuration, a free space extending over a wide range in both the front - rear direction and the left - right direction is secured above the traveling frame 30. In the upper frame part 30u, a plurality of frames in a rectangular shape (rectangle or square) in plan view, which are composed of the left - right inner main rod members 30u1 and outer main rod members 30u2 and a pair of front - rear cross rod members 30u3, are provided continuously in the front - rear direction. The upper end surfaces of the rod members 30u1, 30u2, 30u3 constituting the upper frame part 30u are flush, and the upper end surface of the aforementioned rectangular frame is a flat surface. Therefore, the flat surface of the frame can be provided as the installation surface of the device. Since this flat surface is formed from the front end to the rear end of the upper frame part 30u, a wide space corresponding to the entire front - rear length from the front end to the rear end of the upper frame part 30u is secured on the upper frame part 30u, and various devices can be arranged in this space in various layouts.

[0070] When the upper frame part 30u is divided into three parts, namely a front part, an intermediate part, and a rear part in the front - rear direction, the front part of the upper frame part 30u is arranged above the front wheels 31F, the rear part of the upper frame part 30u is arranged above the rear wheels 31R, and the intermediate part of the upper frame part 30u is arranged between the front wheels 31F and the rear wheels 31R in the front - rear direction.

[0071] That is, above the front wheels 31F, a space (the flat surface of the above-mentioned rectangular frame) that can be used for installing equipment as described above is provided at the front part of the upper frame portion 30u. Above the rear wheels 31R, a space (the flat surface of the above-mentioned rectangular frame) that can also be used for installing equipment is provided at the rear part of the upper frame portion 30u. These front and rear spaces are connected via the middle part of the upper frame portion 30u. Therefore, at the upper part of the upper frame portion 30u, a space for installing equipment composed of flat surfaces of a plurality of rectangular frames is provided over a long range from above the front wheels 31F to above the rear wheels 31R.

[0072] The upper part (the motor housing portion 32a and the transmission mechanism housing portion 32b) of the wheel drive case 32 of the front wheel unit 4F protrudes upward from the front part of the upper frame portion 30u of the traveling frame 30 through the space between the front and rear cross bars 30u3 that constitute the front part of the upper frame portion 30u, and is attached and fixed to at least one cross bar 30u3.

[0073] A plurality of bars extend downward from the front part of the upper frame portion 30u, and a front fender portion 30f that covers the rotating cylinder portion 32c of the wheel drive case 32 of the front wheel unit 4F and the front steering cylinder 35F directly above the front wheels 31F is formed by these plurality of bars.

[0074] Note that the plurality of bars constituting the front fender portion 30f include a vertical bar 30v1 that extends downward from the vicinity of the front end of the inner main bar 30u1. A plate-like mast mounting plate 30c1 that extends forward, backward, upward, and downward is extended in front of the vertical bar 30v1. The traveling side mast member 71 of the mast mechanism 7 (7F) described later is attached and fixed to the left and right inner side surfaces (the surfaces facing the side surface of the vehicle body 2) of the mast mounting plate 30c1.

[0075] The upper part (motor housing part 32a and transmission mechanism housing part 32b) of the wheel drive case 32 of the rear wheel unit 4R projects upward from the rear part of the upper frame part 30u of the traveling frame 30 through the space between the front and rear cross bars 30u3 that constitute the rear part of the upper frame part 30u of the traveling frame 30, and is attached and fixed to at least one cross bar 30u3.

[0076] A plurality of bars extend downward from the rear part of the upper frame part 30u, and a rear fender part 30r that covers the rotating cylinder part 32c of the wheel drive case 32 and the rear steering cylinder 35R of the rear wheel unit 4R directly above the rear wheel 31R is formed by these plurality of bars.

[0077] As described above, among the free spaces provided at the upper part of the upper frame part 30u, the front part is used for the arrangement of the upper part of the wheel drive case 32 of the front wheel unit 4F, and the rear part is used for the arrangement of the upper part of the wheel drive case 32 of the rear wheel unit 4R.

[0078] A still wider free space is secured between the front wheel unit 4F and the rear wheel unit 4R at the upper part of the upper frame part 30u. Using this space, various devices can be mounted on the upper frame part 30u.

[0079] For example, when a chemical spraying device is connected to the work vehicle 1 as the work device 200, it is conceivable to mount a chemical tank for storing the chemical supplied to the chemical spraying device on this part of the upper frame part 30u.

[0080] Here, since the upper frame part 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, even a large - capacity chemical tank can be mounted on the upper frame part 30u so as not to protrude beyond the left - right outer ends of the traveling structure 3.

[0081] An intermediate fender portion 30m is formed so as to extend downward from an intermediate portion of the upper frame portion 30u between the front fender portion 30f and the rear fender portion 30r. Specifically, as shown in FIG. 7, from the inner main rod member 30u1, a vertical rod member 30v2 that defines the front end of the intermediate fender portion 30m (the rear end of the front fender portion 30f) and a vertical rod member 30v3 that defines the rear end of the intermediate fender portion 30m (the front end of the rear fender portion 30r) are extended downward.

[0082] On the other hand, from the outer main rod member 30u2, a vertical rod member 30v4 is extended downward at a position corresponding to the vertical rod member 30v2 in the front-rear direction, and a vertical rod member 30v5 is extended downward at a position corresponding to the vertical rod member 30v3 in the front-rear direction. A rectangular intermediate fender portion 30m whose four corners are defined by these four vertical rod members 30v2, 30v3, 30v4, and 30v5 is formed.

[0083] The lower ends of the vertical rod members 30v2, 30v3, 30v4, and 30v5 are connected by horizontal bottom rod members 30b1, 30b2, 30b3, and 30b4 arranged in a square shape. In this way, at the bottom of the intermediate fender portion 30m, the lower frame portion 30b is constituted by the bottom rod members 30b1, 30b2, 30b3, and 30b4.

[0084] The battery case 36 is placed so as to be bridged between the front and rear bottom rod members 30b1 and 30b4 extending in the left-right direction that constitute the lower frame portion 30b. The battery case 36 placed on the lower frame portion 30b in this way is arranged so as to be surrounded by the vertical rod members 30v2, 30v3, 30v4, and 30v5 that constitute the intermediate fender portion 30m. That is, the battery case 36 is arranged in a space formed between the upper frame portion 30u and the lower frame portion 30b of the traveling frame 30 between the front wheel 31F and the rear wheel 31R.

[0085] Note that the vertical rod member 30v2 at the left and right inner front ends of the intermediate fender portion 30m supports the middle mast mechanism 7M described later, and the vertical rod member 30v3 at the left and right inner rear ends of the intermediate fender portion 30m supports the rear mast mechanism 7R described later.

[0086] That is, a plate-shaped mast mounting plate 30c2 extending in the left-right and up-down directions is extended from the vertical rod member 30v2 to the left and right inner sides (toward the vehicle body 2). On the front surface of the mast mounting plate 30c2, the traveling side mast member 71 of the middle mast mechanism 7M is fixedly attached.

[0087] Also, a plate-shaped mast mounting plate 30c3 extending in the front-back and up-down directions is extended from the vertical rod member 30v3 to the rear. On the left and right inner (opposing side to the vehicle body 2) surfaces of the mast mounting plate 30c3, the traveling side mast member 71 of the rear mast mechanism 7R is fixedly attached.

[0088] The configuration of each traveling structure 3, that is, the configuration of each of the left traveling structure 3L and the right traveling structure 3R is as above. Next, the configuration of the vehicle body 2 disposed between the left traveling structure 3L and the right traveling structure 3R and various devices received by the vehicle body 2 will be described.

[0089] As shown in FIGS. 1 to 6 and the like, the vehicle body 2 has a vehicle body frame structure 20, a front main body case (battery case) 24 supported by the vehicle body frame structure 20, and a rear main body case (PTO case) 26.

[0090] The vehicle body frame structure 20 has a vehicle body center frame 21, a left vehicle body side frame 22L disposed on the left side of the vehicle body center frame 21, and a right vehicle body side frame 22R disposed on the right side of the vehicle body center frame 21. Hereinafter, each of the left vehicle body side frame 22L and the right vehicle body side frame 22R may be referred to as the vehicle body side frame 22.

[0091] The vehicle body center frame 21 has a pair of left and right main rod members 21a extending in the front-back direction and a plurality of lateral cylinder members 21b extending in the left-right direction so as to connect the left and right main rod members 21a.

[0092] A flat plate-shaped support member 23 is fixedly provided at the lower part of the portion from the front end to the middle part in the front-back direction of the vehicle body center frame 21, and a rectangular parallelepiped-shaped front main body case 24 is suspended from the support member 23. The upper end portion of the front main body case 24 is engaged with the support member 23 so as to be movable in the front-back direction.

[0093] Specifically, the support member 23 includes a flat plate portion 23a (see FIG. 6 and the like) attached to the bottom surface of the front portion of the vehicle body center frame 21, and a rail member 23b (see FIG. 4) that extends in the front-rear direction and hangs down from the flat plate portion 23a and is provided with a round bar-shaped rail extending in the front-rear direction at the lower portion.

[0094] On the other hand, an engaging member 24a (see FIG. 4) that extends in the front-rear direction is protruding upward from the upper end surface of the front main body case 24 corresponding to the rail member 23b of the support member 23. A groove extending in the front-rear direction is formed in the engaging member 24a. By fitting the round bar-shaped rail provided on the rail member 23b into this groove, the engaging member 24a is engaged with the rail member 23b so as to be slidable in the front-rear direction, and thereby, the front main body case 24 is supported by the support member 23 so as to be movable in the front-rear direction.

[0095] Note that, in order to ensure the support strength of the front main body case 24, which becomes a heavy object in the state where the center battery 50 described later is housed, by the support member 23, a plurality of combinations of the rail member 23b and the engaging member 24a may be provided. In the present embodiment, four sets of this combination are provided, but the quantity is not limited.

[0096] Furthermore, as shown in FIG. 4, the support member 23 vertically provides support side plate portions 23c on both the left and right sides of the front main body case 24, and provides a horizontal surface portion extending in the front-rear direction at the lower portion thereof to support the front main body case 24 from below.

[0097] Note that the configuration for supporting the front main body case 24 by the vehicle body frame structure 20 so as to be movable in the front-rear direction is not limited to the above-described one, and any structure may be used as long as it can ensure that the front main body case 24 is movable in the front-rear direction with respect to the support member 23 and the vehicle body center frame 21.

[0098] Each side frame 22 of the vehicle body has a main rod member 22a extending in the front-rear direction, a cross rod member 22b extending inwardly to the left and right from the main rod member 22a (see FIGS. 6, 9, etc.), and a plurality of vertical rod members 22c extending vertically downward from the main rod member 22a.

[0099] Note that the lengths of the plurality of vertical rod members 22c in the vertical direction are uniform, and the length in the vertical direction from the upper end of the main rod member 22a to the lower end of the vertical rod member 22c substantially coincides with the maximum width in the vertical direction of the running frame 30 of the running structure 3 (the width in the vertical direction from the upper end of the upper frame portion 30u to the lower end of the lower frame portion 30b).

[0100] In this embodiment, each side frame 22 of the vehicle body is provided with five vertical rod members 22c as the plurality of vertical rod members 22c, namely, vertical rod members 22c1, 22c2, 22c3, 22c4, and 22c5 in order from the front end to the rear of the side frame 22 of the vehicle body. Each vertical rod member 22c is used to support the mast mechanism 7 described later.

[0101] Each cross rod member 22b is slidably inserted into each horizontal cylinder member 21b of the vehicle body center frame 21. In this embodiment, each side frame 22 of the vehicle body has three cross rod members 22b arranged at the front, middle, and rear. Correspondingly, the vehicle body center frame 21 also has three horizontal cylinder members 21b arranged at the front, middle, and rear.

[0102] Both the left and right ends of each horizontal cylinder member 21b of the vehicle body center frame 21 are open ends. Each cross rod member 22b of the left side frame 22L of the vehicle body is inserted into each horizontal cylinder member 21b from the left open end of each horizontal cylinder member 21b, and each cross rod member 22b of the right side frame 22R of the vehicle body is inserted into each horizontal cylinder member 21b from the right open end of each horizontal cylinder member 21b.

[0103] Note that the number and position of the cross rod members 22b in each side frame 22 of the vehicle body are not limited to those described above, and at least one cross rod member 22b may be provided at any part of the side frame 22 of the vehicle body.

[0104] Furthermore, each side frame 22 of the vehicle body only needs to be connected to the center frame 21 of the vehicle body so as to be relatively movable in the left-right direction, and this connection may be by a structure different from the structure in which the cross bar 22b of the side frame 22 of the vehicle body is inserted into the horizontal cylinder 21b of the center frame 21 of the vehicle body as described above.

[0105] In the vehicle body 2 configured by the vehicle body frame structure 20 having such a structure, as shown in FIG. 9, when the extension amount (projection amount) of the cross bar 22b protruding from the horizontal cylinder 21b changes, the left-right direction interval between the left side frame 22L of the vehicle body and the left end of the center frame 21 of the vehicle body, and / or the left-right direction interval between the right side frame 22R of the vehicle body and the right end of the center frame 21 of the vehicle body changes. That is, the width of the vehicle body 2 in the left-right direction is changed, and the vehicle body 2 is deformed.

[0106] And due to the deformation of the vehicle body 2 in the form of changing the width in the left-right direction, the left-right direction interval between the left traveling structure 3L and the right traveling structure 3R, that is, the vehicle width which is the interval between the left front wheel 31FL and the right front wheel 31FR and / or the interval between the left rear wheel 31RL and the right rear wheel 31RR can be changed.

[0107] On the upper part of the center frame 21 of the vehicle body, a pair of width-changing cylinders 8A and 8B extending in the left-right direction are provided as a vehicle body deforming device (actuator) 80 (see FIG. 8) for changing the left-right width of the vehicle body 2, that is, for deforming the vehicle body 2. Hereinafter, each of the pair of width-changing cylinders 8A and 8B may be referred to as a width-changing cylinder 8.

[0108] The width-changing cylinder 8A expands and contracts to change the interval between the center frame 21 of the vehicle body and the left side frame 22L of the vehicle body. The cylinder body of the width-changing cylinder 8A is attached to the upper part of the center frame 21 of the vehicle body, the piston rod extends leftward from the cylinder body, and the tip of the piston rod is attached to the main rod 22a at the upper part of the left side frame 22L of the vehicle body.

[0109] The width-changing cylinder 8B expands and contracts to change the distance between the vehicle body center frame 21 and the right vehicle body side frame 22R. The cylinder body of the width-changing cylinder 8B is attached to the upper part of the vehicle body center frame 21 in front of or behind (in this embodiment, in front of) the cylinder body of the width-changing cylinder 8A. The piston rod extends rightward from the cylinder body, and the tip of the piston rod is attached to the main rod member 22a at the upper part of the right vehicle body side frame 22R.

[0110] In this way, due to the expansion and contraction movement of each width-changing cylinder 8, the protruding amount of the cross bar member 22b from the horizontal cylinder member 21b is changed, and the vehicle body side frame 22 moves forward and backward with respect to the vehicle body center frame 21, and the left and right width of the vehicle body 2 is changed as described above, and the vehicle body 2 is deformed.

[0111] For example, by extending both the width-changing cylinders 8A and 8B (the piston rods thereof), as shown in FIG. 9, both the left vehicle body side frame 22L and the right vehicle body side frame 22R move away from the vehicle body center frame 21, and the vehicle body 2 is deformed such that both the left and right parts expand.

[0112] Accordingly, both the left traveling structure 3L connected to the left vehicle body side frame 22L and the right traveling structure 3R connected to the right vehicle body side frame 22R move away from each other in the left-right direction, and the vehicle width, which is the left-right distance between the left traveling structure 3L and the right traveling structure 3R and the corresponding distance between the left and right wheels 31, expands.

[0113] Regarding the deformation of the vehicle body 2 in the direction of expanding the vehicle width, it is not necessary to synchronously expand and contract both the left vehicle body side frame 22L and the right vehicle body side frame 22R. It is also possible to expand and contract only one of the width-changing cylinders 8A and 8B to move only one of the left vehicle body side frame 22L and the right vehicle body side frame 22R.

[0114] Note that the width-changing cylinder 8 as a vehicle body deformation device for changing the left-right width of the vehicle body 2 may be a cylinder of any structure as long as it functions as a vehicle body deformation device 80, such as a hydraulic cylinder, an air cylinder, an electric cylinder, or the like.

[0115] Also, as long as the vehicle body deformation device 80 has a function of changing the left-right width of the vehicle body 2, it does not necessarily have a structure having a cylinder like the width-changing cylinder 8. For example, it may have a structure in which a screw rod is rotated by a motor to cause the vehicle body side frame 22 to move forward and backward with respect to the vehicle body center frame 21.

[0116] Note that the left and right outer end faces of each vehicle body side frame 22 and the left and right inner end faces of the traveling frame 30 of the corresponding traveling structure 3 facing the same are vertical planes parallel to each other. That is, each side vehicle body side frame 22 does not have a portion that extends outward in the left and right directions and reaches above the upper frame portion 30u so as to obstruct the mounting of equipment on the upper frame portion 30u of the traveling frame 30 of each traveling structure 3. Thus, the upper frame portion 30u of the traveling frame 30 of each traveling structure 3 can be effectively utilized for mounting equipment over its entire left-right width.

[0117] For example, all of the cross bars 22b of the left vehicle body side frame 22L extend from the main bar 22a inward in the left and right directions of the vehicle body 2 on the side opposite to the left traveling structure 3L, and at the left end faces of a plurality of vertical bars 22c (vertical bars 22c1, 22c2, 22c3, 22c4, 22c5) that extend vertically downward from the main bar 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, a flat vertical plane is formed from the upper end to the lower end.

[0118] On the other hand, also at the right end of the left traveling frame 30L of the left traveling structure 3L, at the right end faces of the vertical bars 30v1, 30v2, 30v3 that extend vertically downward from the inner main bar 30u1, that is, at the right (left and right inner) end of the left traveling frame 30L, a flat vertical plane is formed from the upper end to the lower end.

[0119] In this way, the vertical plane at the left end (left and right outer side) of the left vehicle body side frame 22L is parallel to the vertical plane at the right end (left and right inner side) of the left traveling frame 30L, and an interval with a constant left and right width in the front-rear direction is secured between the two vertical planes. Also, since all the devices mounted on the vehicle body 2 are arranged 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, the left vehicle body side frame 22L and the left traveling frame 30L do not interfere with each other when, for example, the vehicle body 2 moves up and down with respect to the traveling structure 3 of the vehicle body 2, and a wide free space can be secured in the left and right directions also above the upper frame portion 30u of the left traveling frame 30L.

[0120] The right vehicle body side frame 22R and the right traveling frame 30R have the same structure. Similarly, an interval with a constant left and right width in the front-rear direction is secured between the right end (left and right outer side) of the right vehicle body side frame 22R and the left end (left and right inner side) of the right traveling frame 30R. Also, as described above, since all the devices mounted on the vehicle body 2 are arranged 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, the same effect, that is, the effect that the right vehicle body side frame 22R and the right traveling frame 30R do not interfere with each other when the vehicle body 2 moves up and down with respect to the right traveling frame 30R, is achieved.

[0121] As for the entire vehicle body 2, the left vehicle body side frame 22L of the vehicle body frame structure 20 is connected to the left traveling frame 30L of the left traveling structure 3L, and the right vehicle body side frame 22R is connected to the right traveling frame 30R of the right traveling structure 3R so as to be relatively vertically movable via a plurality of mast mechanisms 7 arranged between the vehicle body 2 (each vehicle body side frame 22) and each traveling structure 3 (each traveling frame 30). Thus, the vehicle body 2 can move (ascend and descend) in the vertical direction with respect to the left and right traveling structures 3. The configuration of the mast mechanism 7 will be described in detail later.

[0122] The work vehicle 1 is provided with a pair of left and right vehicle body lifting cylinders 9, that is, a left vehicle body lifting cylinder 9L and a right vehicle body lifting cylinder 9R, as an actuator (hydraulic actuator) for lifting the vehicle body 2, that is, as a vehicle body moving device 90 (see FIG. 8) for relatively moving the vehicle body 2 with respect to the left and right traveling structures 3.

[0123] The cylinder bottom, which is the upper end of each vehicle body lifting cylinder 9 (left vehicle body lifting cylinder 9L, right vehicle body lifting cylinder 9R), is connected to the lower part of the main rod member 22a of the vehicle body side frame 22. On the other hand, the piston rod head, which is the lower end of each vehicle body lifting cylinder 9, is supported by a bracket or the like protruding inwardly (toward the vehicle body 2) from the left and right inner ends of the traveling frame 3.

[0124] That is, in the left - right direction of the work vehicle 1, each vehicle body lifting cylinder 9 with its upper end connected to the upper part of each vehicle body side frame 22 is arranged at a position offset inward in the left - right direction from the left and right inner ends of the traveling structure 3. That is, each vehicle body lifting cylinder 9 does not protrude outward in the left - right direction from the corresponding vehicle body side frame 22 and does not intrude into the traveling frame 3 or the upper space above the traveling frame 3. Also, by this, a wide free space where various devices can be mounted is secured above the upper frame portion 30u of the traveling frame 30 of each traveling structure 3.

[0125] Normally, the piston rods of the left vehicle body lifting cylinder 9L and the right vehicle body lifting cylinder 9R are contracted, and the vehicle body 2 is arranged at the lowest position in its up - down movement range as shown in FIGS. 1 to 5 and the like. When the left vehicle body lifting cylinder 9L and the right vehicle body lifting cylinder 9R simultaneously extend the piston rods with the same stroke, the entire vehicle body 2 rises. Specifically, due to the extension movement of the piston rods of the left vehicle body lifting cylinder 9L and the right vehicle body lifting cylinder 9R, the vehicle body 2 moves upward with respect to the left and right traveling structures 3 while being guided by the mast mechanism 7.

[0126] Incidentally, it is also conceivable to adjust the left-right tilt of the vehicle body 2 by differential expansion and contraction of the left vehicle body lifting cylinder 9L and the right vehicle body lifting cylinder 9R. For example, when the left traveling structure 3L becomes lower than the right traveling structure 3R due to the tilt of the ground to the lower left, and the vehicle body 2 tilts to the lower left, the left vehicle body lifting cylinder 9L alone is extended to move the left part of the vehicle body 2 upward relative to the left traveling structure 3L, so that it is conceivable to horizontally hold the vehicle body 2 in the left-right direction.

[0127] Incidentally, the vehicle body lifting cylinders 9 do not have to be a pair on the left and right, and are not limited in terms of quantity or position within the vehicle body 2. Further, the actuator for moving the vehicle body 2 in the vertical direction does not have to be a telescopic actuator such as the vehicle body lifting cylinder 9, and for example, it may be configured to move the vehicle body 2 in the vertical direction by the rotation of an electric motor.

[0128] Incidentally, in the present embodiment, as described above, the width change cylinder 8 which is the vehicle body deformation device 80 and the vehicle body lifting cylinder 9 which is the vehicle body moving device 90 are hydraulic actuators, and the expansion and contraction movements are controlled by the control device 15 controlling the respective control valves in the control valve unit 27.

[0129] Incidentally, the width change cylinders 8 and the vehicle body lifting cylinders 9 described in FIG. 8 respectively mean the width change cylinders 8A and 8B and the vehicle body lifting cylinders 9L and 9R, and the control device 15 can individually control the expansion and contraction movements of each of these.

[0130] As shown in FIGS. 11 to 13, a battery (center battery) 50 is housed in the front body case 24. Considering the weight balance of the entire work vehicle 1 of this heavy object battery 50, or for other reasons (for example, in relation to the layout of the devices in the vehicle body 2), the front body case 24 is movable relative to the vehicle body center frame 21 (vehicle body frame structure 20) in the front-rear direction. That is, the vehicle body 2 is also deformed when the front body case 24 moves back and forth relative to the vehicle body center frame 21.

[0131] In addition, in order to move the front main body case 24 back and forth with respect to the vehicle body center frame 21, a battery moving actuator 81, which is a hydraulic cylinder for example, may be provided as a vehicle body deformation device 80 (see FIG. 8). Alternatively, without providing such a vehicle body deformation device, an operator may directly push or pull the front main body case 24 by hand to move it back and forth with respect to the vehicle body center frame 21.

[0132] An air temperature adjustment device (air conditioner unit) 51 is attached to the front end face of the front main body case 24 in a forward protruding manner, and a radiator 52 is provided directly in front of the air temperature adjustment device 51. A radiator fan 52a is provided at the front end of the radiator 52. That is, an air cooling device and a water cooling device are provided directly in front of the front main body case 24.

[0133] The air temperature adjustment device 51 and the radiator fan 52a of the radiator 52 can be operated by electric power supplied from the battery 50.

[0134] As shown in FIGS. 5, 12, and 13, a bracket 25 hangs down from the vehicle body center frame 21 behind the front main body case 24 that houses the battery (center battery) 50. A rear main body case (PTO case) 26 hangs down from the lower end of the bracket 25.

[0135] In this way, the rear main body case 26 is disposed behind the front main body case 24 and is supported by the vehicle body frame structure 20 of the vehicle body 2 via the bracket 25.

[0136] As described above, considering the weight balance and the like, when the front main body case 24 is moved relatively forward with respect to the vehicle body center frame 21, as shown in FIG. 12, a space portion S1 having a certain width in the front-rear direction is formed between the rear end of the front main body case 24 and the bracket 25 fixed to the vehicle body center frame 21 behind it.

[0137] Hereinafter, this space part S1 will be described. That is, the work vehicle 1 includes a vehicle body 2 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 and 3R provided on the left and right sides of the vehicle body 2, and a moving mechanism for moving the vehicle body 2 in the vertical direction. The vehicle body 2 has a space part S1 formed at least between the first device and the second device. The moving mechanism positions the space part S1 between at least the first device and the second device and between the left and right traveling structures 3L and 3R when the vehicle body 2 is in the lowest state, and positions the space part S1 between at least the first device and the second device and above the left and right traveling structures 3L and 3R when the vehicle body 2 is in the highest state, as long as it has such a structure.

[0138] The moving mechanism is the aforementioned vehicle body moving device 90, which is the vehicle body lifting cylinders 9L and 9R that are hydraulic actuators in this embodiment. However, as described above, it is not limited to such telescopic hydraulic actuators, and actuators with various configurations may be used as the moving mechanism of the vehicle body moving device 90.

[0139] Also, in this embodiment, the first device is the battery 50 housed in the front body case 24, and the second device is the electrical equipment (electric motor 53) or hydraulic equipment (hydraulic pump 55) housed in the rear body case 26. However, it is not limited to these. For example, the applications of these first and second devices may be reversed. Also, for example, when a spraying device such as a chemical agent is mounted on the vehicle body 2 as a working device, the spraying device, chemical agent tank, etc. may be used as the first device or the second device, and there is no limitation on what kind of device it is.

[0140] Also, it is conceivable that the vehicle body 2 has the space part S1 behind the first device mounted on the front part of the vehicle body 2. In this case, only the position of the first device is specified as the front part of the vehicle body 2, and the position of the second device is not specified. In the case of the work vehicle 1 having the above-described configuration, for example, a space part S1 may be provided behind the radiator 52 disposed at the front end of the vehicle body 2, and the battery 50 housed in the front body case 24 may be arranged behind the space part S1 as the second device.

[0141] Also, it is conceivable that the vehicle body 2 has a space S1 between the first device and the second device mounted on the rear part of the vehicle body 2. In this case, only the position of the second device is specified as the rear part of the vehicle body 2, and the position of the first device is not specified. In the case of the work vehicle 1 having the above-described configuration, for example, a work device mounted on the upper part of the rear end of the rear body case 26 or a connecting device for connecting the work devices is used as the second device, and a control valve unit 27 attached to a bracket 25 that supports the rear body case 26 in front of it is used as the first device. It is also conceivable that a space between the first device and the second device above the rear body case 26 is defined as the space S1.

[0142] Also, it is conceivable that the vehicle body is configured such that the position of the first device can be changed back and forth, and the vehicle body 2 can be switched between a state having the space S1 and a state not having the space S1 by the position change of the first device. In the present embodiment, as described above, the battery 50 as the first device can be moved back and forth, but the present invention is not limited to this. For example, as described above, the applications as the first device and the second device are reversed, and electrical equipment or hydraulic equipment in the rear body case 26 is used as the first device, and the rear body case 26 is made movable back and forth so that it can be switched between a state with the space S1 and a state without the space S1.

[0143] Also, as a device for changing the position of the first device back and forth, in the present embodiment, on the premise that the first device is the battery 50, the work vehicle 1 is provided with a battery moving actuator 81, but the present invention is not limited to this. The configuration of the moving means of the first device may be considered depending on what device is used as the first device. Also, as described above, a configuration may be adopted in which the operator manually moves the first device without providing an actuator.

[0144] Furthermore, the specific configuration of this space S1 will be described.

[0145] That is, in the present embodiment, by moving the front body case 24 back and forth, a space S1 can be switched between a state where there is a space S1 and a state where there is no space S1 between devices such as the battery 50 housed in the front body case 24 and electrical equipment such as the electric motor 53 and hydraulic equipment such as the hydraulic pump 55 housed in the rear body case 26, as shown in FIG. 13.

[0146] As shown in FIGS. 12 and 13, when the front body case 24 is moved forward together with the battery 50 to provide the space S1, by using the space S1, for example, an oil hydraulic actuator tank 58 or the like for storing the hydraulic oil supplied to an oil hydraulic actuator or the like provided in the work vehicle 1 can be attached to the front part of the bracket 25.

[0147] This space S1 is covered on the left and right by the left traveling structure 3L and the right traveling structure 3R in the normal state where the vehicle body 2 is lowered. Also, in the front, it is covered by devices such as the battery 50 housed in the front body case 24, and in the rear, it is covered by devices such as the hydraulic equipment and electrical equipment housed in the rear body case 26. Thus, since it is covered from the four directions of front, rear, left, and right, the protection of devices such as the oil hydraulic actuator tank 58 provided in the space S1 can be ensured.

[0148] 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 insert a hand into the space S1 or the like to gain access to the inside of the space S1. Therefore, when the vehicle body 2 is raised, it is possible to remove devices such as the oil hydraulic actuator tank 58 inside the space S1.

[0149] Regarding the state of the space S1 when the vehicle body 2 is raised in detail, when the vehicle body is raised, the front and rear of the space S1 remain covered from two directions by devices such as the battery 50 housed in the front body case 24 and hydraulic equipment and electrical equipment housed in the rear body case 26. On the other hand, since the space S1 is arranged above the left and right traveling structures 3L and 3R, the traveling structures 3 do not exist on both the left and right sides thereof. Therefore, the space S1 is opened on both the left and right sides, that is, it is in a state of being left - right penetrating and exposed on both the left and right sides.

[0150] Further, by making the entire space part S1 a free space without providing equipment such as the hydraulic oil tank 58, for example, through the space part S1, an operator can insert a hand into the front body case 24 to perform maintenance on the battery 50 and the like.

[0151] In addition, with respect to the vehicle body frame structure 20 of the vehicle body 2, since a sufficient allowable width for allowing the front - rear movement of the front body case 24 for housing the center battery 50 is ensured, regarding the size of the space part S1 formed by the forward movement of the front body case 24, by greatly moving the front body case 24 forward, it is not a slight size that allows an operator to insert the fingertips of one hand with some difficulty. For example, as described above, a space part S1 of a sufficient size can be provided for an operator to insert one hand deep into the space part S1 to perform maintenance work or to arrange members such as the hydraulic oil tank 58.

[0152] In the rear body case 26, an electric motor 53 as a work system prime mover and an inverter 54 (see FIGS. 8 and 12) are housed. A PTO shaft 5 is pivotally supported in the rear body case 26. As shown in FIG. 5, the PTO shaft 5 protrudes rearward from the rear end of the rear body case 26 which is the rear end part of the vehicle body 2.

[0153] The electric motor 53 is driven by obtaining power from the center battery 50, and drives the PTO shaft 5 with its output. The inverter 54 converts the direct current from the center battery 50 into an alternating current, and applies the alternating current to the electric motor 53 at a set voltage and / or frequency.

[0154] As shown in FIG. 8, by controlling the set values of the voltage and / or frequency of the inverter 54 by the control device 15, the output rotation speed and / or torque of the electric motor 53 are controlled, and thereby the rotation speed and / or torque of the PTO shaft 5 are controlled.

[0155] Note that a transmission mechanism for transmitting the output of the electric motor 53 to the PTO shaft 5 may be provided in the rear body case 26. This transmission mechanism may have gears, endless belts, or other structures. Further, this transmission mechanism may be a stepped or stepless transmission mechanism. Additionally, a clutch, a braking device, or the like may be provided in this transmission mechanism.

[0156] As shown in FIGS. 5, 12, etc., a pair of left and right lower link brackets 26a are provided at the lower left and lower right corners of the rear end portion of the rear body case 26. Further, a top link bracket 26b is provided at the left and right intermediate position in the upper part of the rear end surface of the rear body case 26.

[0157] When mounting the connecting device 6, which is a three-point link mechanism, to the vehicle body 2, the front end portions of the left and right lower links 6a are attached to the left and right lower link brackets 26a, and the front end portion of the top link 6b is attached to the top link bracket 26b.

[0158] Also, as shown in FIGS. 5, 6, etc., a lift arm base 26c that rotatably supports a rotation fulcrum shaft extending in the left-right direction is provided on the upper end surface of the rear body case 26, and a pair of left and right lift cylinder brackets 26d are provided at the lower part of the rear end surface of the rear body case 26.

[0159] When mounting the connecting device 6, which is a three-point link mechanism, to the rear body case 26, the front end portions of a pair of left and right lift arms 60 are attached to both left and right ends of the rotation fulcrum shaft supported by the lift arm base 26c. Thereby, the left and right lift arms 60 are pivotally supported by the lift arm base 26c so as to be integrally rotatable.

[0160] Lift cylinders 61 are respectively 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.

[0161] The left and right lift cylinders 61 are configured to expand and contract synchronously. Due to the expansion and contraction of the left and right lift cylinders 61, the left and right lift arms 60 rotate integrally about the pivot axis at the front end.

[0162] Furthermore, as shown in FIGS. 5 and 6, one of the left and right lift arms 60 and the corresponding lower link 6a on that side are connected via a lift rod 62 having a fixed length, while the other of the left and right lift arms 60 and the corresponding lower link 6a on that side are connected via a posture adjustment cylinder 63 that can expand and contract.

[0163] In this way, the left and right lower links 6a are connected to the left and right lift arms 60 via the lift rod 62 and the posture adjustment cylinder 63. As the rear ends of the left and right lift arms 60 move up and down due to the expansion and contraction of the left and right lift cylinders 61, the rear ends of the left and right lower links 6a move up and down following them. Thereby, the working device 200 mounted on the rear ends of the left and right lower links 6a and the rear end of the top link 6b in the connecting device 6 moves up and down (rises and falls).

[0164] Also, 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 the expansion and contraction of the posture adjustment cylinder 63, the inclination angle in the left - right direction of the working device 200 mounted on the connecting device 6 is adjusted.

[0165] With this configuration, for example, even if the working device 200 during agricultural work is tilted left and right due to the slope of the field, by adjusting the distance between the lift arm 60 and the lower link 6a by the expansion and contraction of the posture adjustment cylinder 63, the working device 200 is maintained in a horizontal state in the left - right direction. For example, a good ridge without inclination in the left - right direction can be formed in the working track of the working device 200 which is a ridging device.

[0166] As described above, the connecting device 6 mounted behind the rear body case 26 (the rear part of the vehicle body 2) can connect the working device 200. Further, the working device 200 connected behind the vehicle body 2 via the connecting device 6 can receive driving force from the PTO shaft 5 protruding from the rear end surface of the rear body case 26.

[0167] Examples of the working device 200 include devices for performing operations related to agriculture (farming operations), devices for performing operations related to civil engineering, devices for performing operations related to construction, and devices for performing operations related to transportation, etc., but are not limited to these working devices. In the case of the embodiment shown below, the working device 200 is a device for performing farming operations.

[0168] Examples of the working device 200 for performing farming operations include a spraying device for spraying substances such as fertilizers and chemicals, a seeding device for sowing seeds, a tilling device for cultivating the soil, a plowing device (plow) for plowing the soil, a weeding device for weeding, a soil heaping device for heaping soil, etc. However, the working device 200 only needs to be a device for performing farming operations, and its type is not particularly limited.

[0169] Further, when the working device 200 is an electric working device, instead of being driven by the power taken out from the PTO shaft 5, it may be driven by the power taken out to the outside of the vehicle body 2 via a power line from the battery 50.

[0170] Note that the working device 200 may be connected to the work vehicle 1 while being arranged on the side or front of the vehicle body 2. Further, for example, when the working device 200 is arranged in front of the work vehicle 1, the connecting device 6 is mounted on, for example, the front body case 24, and the working device 200 arranged in front of the work vehicle 1 is connected to the work vehicle 1 via the connecting device 6 mounted on the front part of the vehicle body 2 in this way.

[0171] In addition to, or instead of, the PTO shaft 5 provided at the rear part of the vehicle body 2, for example, a front PTO shaft may be provided forward from the front main body case 24, and the working device 200 in front of the work vehicle 1 may be driven by the front PTO shaft. Note that, as such a front-mounted agricultural working device (implement) 200, for example, a combine unit formed by combining a cutting unit, a threshing unit, a sorting unit, etc. of a combine can be considered.

[0172] Further, the aforementioned lower link bracket 26a, top link bracket 26b, and lift cylinder bracket 26d may be detachable from the rear end portion of the rear main body case 26, and may be selected according to the configuration of the connecting device 6 attached to the rear main body case 26 and attached to the rear end portion of the rear main body case 26.

[0173] In addition, an attachment portion to which the connecting device 6 can be attached may be provided at a portion of the vehicle body 2 other than the rear main body case 26, for example, the front main body case 24, so that the working device 200 can be connected to the work vehicle 1 in front of the vehicle body 2.

[0174] For example, when the working device 200 is mounted at a portion other than the rear of the rear main body case 26, such as in front of the front main body case 24, the brackets 26a, 26b, 26d, etc. may be attached to the portion prepared for mounting the connecting device 6 at that position.

[0175] Furthermore, the working device 200 may be mounted on the upper part of the vehicle body frame structure 20 of the work vehicle 1, for example, the vehicle body 2, without passing through the connecting device 6. In this case, a PTO shaft for transmitting driving force to the working device 200 may be provided to protrude upward from the upper part of the vehicle body frame structure 20 (for example, the vehicle body center frame 21).

[0176] The work vehicle 1 is equipped with hydraulic actuators such as the width change cylinder 8 provided on the vehicle body 2, the vehicle body lift cylinder 9, and the steering cylinder 35 provided on the traveling structure 3 as described above. Further, the connecting device 6 attached to the vehicle body 2 may also be equipped with hydraulic actuators such as the lift cylinder 61 and the attitude adjustment cylinder 63 described above.

[0177] For the operation control of these hydraulic actuators, as shown in FIGS. 5, 6, and 12, one or more control valve units 27 are attached to the rear end face of the bracket 25, the upper end of the lift arm base 26c, etc. outside the rear body case 26.

[0178] 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 to be hydraulically controlled, and also has ports for fluidly connecting the control valve to the hydraulic pump 55, the hydraulic actuator, etc. via oil pipes and the like.

[0179] Note that one control valve unit 27 may be configured by combining control valves for different hydraulic actuators to be hydraulically controlled. Also, a configuration may be adopted in which a control valve is provided not only outside the rear body case 26 as described above, but also inside the rear body case 26.

[0180] Furthermore, when the control valve of the control valve unit 27 is an electromagnetic valve or the like, the control valve unit 27 may be electrically connected to the control device 15 or the like by an electric wire or the like.

[0181] Note that instead of the battery 50, an internal combustion engine (engine) may be arranged inside the front body case 24 or the like, the hydraulic pump 55 for operating the above-described hydraulic actuator may be driven by the engine output, and the PTO shaft 5 may be driven by transmitting the engine output to the PTO shaft 5.

[0182] As described above, the vehicle body 2 can be "deformed" by the front main body case 24 moving in the front-rear direction with respect to the vehicle body center frame 21 and the left and right vehicle body side frames 22 moving in the left-right direction with respect to the vehicle body center frame 21. The width change cylinder 8 functions as a vehicle body deformation device (actuator) for deforming the vehicle body 2.

[0183] Further, the vehicle body 2 can "move" in the vertical direction relative to the left and right traveling structures 3. The vehicle body lifting cylinder 9 functions as a vehicle body moving device (actuator) for moving the vehicle body 2.

[0184] Furthermore, the vehicle body 2 can be equipped with the connecting device 6, and can be switched between a state in which the working device 200 is connected via the connecting device 6 and a state in which the working device 200 is not connected.

[0185] Hereinafter, the "deformation", "movement", and "switching between the state of connecting and not connecting the working device 200" of the vehicle body 2 as described above may be collectively referred to as the "state change" of the vehicle body 2.

[0186] As shown in FIG. 8, a vehicle body state change device 100 is defined as the entire device for changing the state of the vehicle body 2, including a vehicle body deformation device 80 including a width change cylinder 8, a battery moving actuator 81, etc., a vehicle body moving device 90 including a vehicle body lifting cylinder 9, etc., and a connecting device 6 including a lift cylinder 61 and an attitude adjustment cylinder 63, etc., which can connect the working device 200 to the vehicle body and are for lifting and attitude adjustment of the working device 200. The control device 15 controls each device included in the vehicle body state change device 100.

[0187] Next, the structure of the mast mechanism 7 that connects the vehicle body 2 and the left and right traveling structures 3 will be described in detail with reference to FIGS. 14 to 19 and the like.

[0188] The left vehicle body side frame 22L is connected to the traveling frame 30 of the left traveling structure 3L via a plurality of mast mechanisms 7, and the right vehicle body side frame 22R is connected to the traveling frame 30 of the right traveling structure 3R via a plurality of mast mechanisms 7.

[0189] Each mast mechanism 7 includes a plurality of mast members 70 that are combined so as to be relatively movable in the vertical direction with respect to each other, and a restricting portion 74 that prevents relative movement in the horizontal direction between the plurality of mast members 70.

[0190] The plurality of mast members 70 of each mast mechanism 7 include a traveling-side mast member 71, a vehicle-body-side mast member 72, and an intermediate mast member 73. The traveling-side mast member 71 is attached (fixed) to each mast mounting plate portion 30c (30c1, 30c2, 30c3) of the traveling frame 30 shown in FIG. 7 and the like. The vehicle-body-side mast member 72 is attached (fixed) to the vertical rod members 22c1 to 22c5 of the vehicle-body-side frame 22 shown in FIGS. 7 and 12 and the like. The intermediate mast member 73 is interposed between the traveling-side mast member 71 and the vehicle-body-side mast member 72.

[0191] The traveling-side mast member 71, the vehicle-body-side mast member 72, and the intermediate mast member 73 are strip-shaped plate materials that are long in the vertical direction, and are combined in a state where both ends are substantially aligned in one horizontal direction. Here, as shown in FIG. 15 and the like, the restricting portion 74 of the mast mechanism 7 is a portion or member that has a function of preventing relative movement in the one horizontal direction between the traveling-side mast member 71, the vehicle-body-side mast member 72, and the intermediate mast member 73, and maintaining the state where the aforementioned both ends are aligned.

[0192] In the present embodiment, restricting members 75 are provided on each of the vertical rod members 22c1 to 22c5 of the vehicle-body-side frame 22, and the restricting members 75 are bent in a "C" shape in a plan view, and the bent portion is used as the restricting portion 74. The vehicle-body-side mast member 72 is attached and fixed to each of the restricting members 75 in a state where both ends in the one direction thereof are along a pair of restricting portions 74. The restricting portion 74 has a structure for preventing relative movement in the one horizontal direction of the traveling-side mast member 71, the vehicle-body-side mast member 72, and the intermediate mast member 73.

[0193] Note that the regulating unit 74 only needs to have a function of preventing the relative movement of the plurality of mast members 70 in the horizontal direction as described above, and the structure thereof does not matter.

[0194] As shown in FIGS. 14, 16, etc., in each mast mechanism 7, the traveling side mast member 71, the vehicle body side mast member 72, and the intermediate mast member 73 have their upper and lower ends substantially aligned when the vehicle body 2 is in the normal state (non-ascended position).

[0195] As shown in FIGS. 17 to 19, etc., when the vehicle body 2 ascends, the vehicle body side mast member 72 ascends together with the vehicle body 2, and its upper end protrudes above the upper end of the traveling side mast member 71. As the vehicle body side mast member 72 ascends, the upper end of the intermediate mast member 73 also protrudes above the upper end of the traveling side mast member 71 by an amount smaller (for example, half) than the protruding amount of the vehicle body side mast member 72.

[0196] During the ascent of the vehicle body 2, guided by the regulating unit 74, the vehicle body side mast member 72 and the intermediate mast member 73 are held in a state where their both ends in the horizontal one direction are aligned with the traveling side mast member 71. Thereby, even when the vehicle body 2 moves vertically with respect to the left and right traveling structures 3, the position of the vehicle body 2 does not shift horizontally with respect to the left and right traveling structures 3. That is, the connection state in which the vehicle body 2 and the left and right traveling structures 3 can relatively move vertically is maintained.

[0197] Note that the larger the vertical length of the plurality of mast members 70 is, the larger the vertical movement amount of the vehicle body 2 with respect to the left and right traveling structures 3 of the vehicle body 2 can be. That is, the maximum vehicle height, which is the vehicle height of the work vehicle 1 when the vehicle body 2 is ascended to the limit height, can be increased.

[0198] If the vertical length of each mast member 70 can be increased, it is also possible to configure the mast mechanism 7 with only two mast members 70, namely, the traveling side mast member 71 and the vehicle body side mast member 72 that are sufficiently long, excluding the intermediate mast member 73.

[0199] However, while the vertical length of the mast member 70 substantially corresponds to the vertical lengths of the vehicle body 2 and the traveling structure 3, there are limitations in setting the dimensions of the vertical lengths of the vehicle body 2 and the traveling structure 3. Therefore, there is also a limit to the vertical length of the mast member 70.

[0200] Therefore, in the mast mechanism 7 according to the present embodiment, by interposing the intermediate mast member 73 between the traveling-side mast member 71 and the vehicle-body-side mast member 72, the vertical length of each mast member 70 is suppressed to a degree corresponding to the vertical lengths of the vehicle body 2 and the traveling structure 3. On the other hand, even in a state where the lower end of the vehicle-body-side mast member 72 is disposed above the upper end of the traveling-side mast member 71, since the intermediate mast member 73 is interposed between the traveling-side mast member 71 and the vehicle-body-side mast member 72, the traveling-side mast member 71 and the vehicle-body-side mast member 72 are not separated, and the maximum vehicle height of the work vehicle 1 can be increased while maintaining the above-described connection state between the vehicle body 2 and the left and right traveling structures 3.

[0201] Next, the layout of the plurality of mast mechanisms 7 will be described with reference to FIGS. 6, 9, 14 to 19, etc.

[0202] The work vehicle 1 includes a vehicle body 2 movable in the vertical direction, a traveling structure 3 provided on the side of the vehicle body 2, a first member (traveling-side mast member 71) attached to the traveling structure 3, a second member (vehicle-body-side mast member 72) attached to the vehicle body 2 and movable in the vertical direction along the first member (traveling-side mast member 71) to raise and lower the vehicle body 2, and a plurality of mast mechanisms 7 each having a restricting portion 74 that restricts the movement of the second member (vehicle-body-side mast member 72) in a direction intersecting the vertical direction. The plurality of mast mechanisms 7 include a first mast mechanism 7 and a second mast mechanism 7 attached to the traveling structure 3 and the vehicle body 2 such that the restricting directions of the respective restricting portions 74 are different from each other.

[0203] That is, the vehicle body 2 and the traveling structure 3 are connected by a plurality of mast mechanisms 7, and it is sufficient that the plurality of mast mechanisms 7 include a first mast mechanism 7 and a second mast mechanism 7 with different regulation directions by the regulation unit 74. The number of the plurality of mast mechanisms 7 is not limited, and the regulation directions of the first mast mechanism 7 and the second mast mechanism 7 may be any directions. For example, the regulation direction of the first mast mechanism 7 may be a certain diagonal direction, and the regulation direction of the second mast mechanism 7 may be a diagonal direction that is 90 degrees different from the described direction of the first mast mechanism 7. Note that the angle difference between the regulation direction of the first mast mechanism 7 and the regulation direction of the second mast mechanism is not limited to 90 degrees, and any angle difference is acceptable as long as the regulation directions are different.

[0204] Also, regarding the materials, shapes, sizes, etc. of the first member and the second member, they do not have to be strip-shaped plate materials such as the traveling-side mast member 71 and the vehicle-body-side mast member 72. As long as the second member is movable in the vertical direction and is suitable for receiving movement regulation by the regulation unit as described above, any member may be used.

[0205] Also, the structure of the regulation unit 74 is configured by a regulation member 75 having a pair of bent portions arranged oppositely in the regulation direction in the above-described embodiment, but the structure is not limited thereto. As long as the second member (vehicle-body-side mast member 72) attached to the vehicle body 2 is movable in the vertical direction with respect to the first member (traveling-side mast member 71) and can regulate the movement of the second member (vehicle-body-side mast member 72) in the regulation direction, any structure may be used.

[0206] In this embodiment, the first mast mechanism 7A is attached to the traveling structure 3 and the vehicle body 2 such that the regulation unit 74 regulates the movement of the second member (vehicle-body-side mast member 72) in the front-rear direction, and the second mast mechanism 7B is attached to the traveling structure 3 and the vehicle body 2 such that the regulation unit 74 regulates the movement of the second member (vehicle-body-side mast member 72) in the left-right direction.

[0207] In this embodiment, a plurality of mast mechanisms 7 including a first mast mechanism 7A and a second mast mechanism 7B are arranged in parallel in the front-rear direction on each of the left and right sides of the vehicle body 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 part, the rear part, and the front-rear intermediate part between the front part and the rear part on the left side or the right side of the vehicle body 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 part, the rear part, and the front-rear intermediate part between the front part and the rear part on each of the left and right sides of the vehicle body 2. More specifically, the first mast mechanism 7A is provided at each of the front part and the rear part, and the second mast mechanism 7B is provided at the front-rear intermediate part.

[0208] That is, in this embodiment, among the plurality of mast mechanisms 7 composed of a front mast mechanism 7F, a middle mast mechanism 7M, and a rear mast mechanism 7R, the front mast mechanism 7F and the rear mast mechanism 7R are taken as the first mast mechanism 7A whose regulation direction is the front-rear direction, and the middle mast mechanism 7M is taken as the second mast mechanism 7B whose regulation direction is the left-right direction.

[0209] Also, among 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 arranged at the same position in the front-rear direction of the vehicle are unified by one of the first mast mechanism and the second mast mechanism.

[0210] It is only necessary that the regulation directions of the left and right mast mechanisms 7 arranged at the same position in the front-rear direction are unified, and they can be unified in any regulation direction.

[0211] Hereinafter, the specific configuration regarding the layout of the mast mechanism 7 of this embodiment will be described in detail.

[0212] In the work vehicle 1 according to this embodiment, on each of the left and right sides of the vehicle body 2, three mast mechanisms 7, namely, a front, a middle, and a rear mast mechanism, are arranged between the vehicle body side frame 22 and the traveling frame 30.

[0213] Hereinafter, the front, middle, and rear mast mechanisms 7 between each vehicle body side frame 22 and the running frame 30 on that side may be referred to as a front mast mechanism 7F, a middle mast mechanism 7M, and a rear mast mechanism 7R.

[0214] Furthermore, hereinafter, the front, middle, and rear mast mechanisms 7 between the left vehicle body side frame 22L and the left running frame 30L may be referred to as a left front mast mechanism 7FL, a left middle mast mechanism 7ML, and a 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 may be referred to as a right front mast mechanism 7FR, a right middle mast mechanism 7MR, and a right rear mast mechanism 7RR.

[0215] 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 face each other. The horizontal direction in which the movement of the mast member 70 is restricted is defined as the restricting direction. The front mast mechanism 7F, the middle mast mechanism 7M, and the rear mast mechanism 7R between each vehicle body side frame 22 and the running frame 30 on that side include at least two mast mechanisms 7 having different restricting directions.

[0216] In the present embodiment, the front mast mechanism 7F, the middle mast mechanism 7M, and the rear mast mechanism 7R between each vehicle body side frame 22 and the running frame 30 on that side include a first mast mechanism 7A having the front-rear direction as the restricting direction and a second mast mechanism 7B having the left-right direction as the restricting direction.

[0217] 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 in a state where the short side of the rectangular surface of the mast member 70, which is a plate-like member, is arranged along the front-rear 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 in a state where the short side is arranged along the left-right direction of the vehicle body 2 and the running structure 3.

[0218] Furthermore, in the present embodiment, the front mast mechanism 7F and the rear mast mechanism 7R are the first mast mechanism 7A whose regulation direction is the front-rear direction, and the middle mast mechanism 7M is the second mast mechanism 7B whose regulation direction is the left-right direction.

[0219] Here, the attachment structure of the specific mast mechanism 7 to the vehicle body 2 and the traveling structure 3 will be described. First, as described above, the vertical rod members 30v1, 30v2, 30v3 at the left and right inner ends of each traveling frame 30 and the vertical rod members 22c1, 22c2, 22c3, 22c4, 22c5 of each vehicle body side frame 22 at the left and right outer ends of the vehicle body 2 are used to support the mast mechanism 7.

[0220] In the front-rear direction, the positions of the vertical rod member 22c2 and the vertical rod member 30v1 are substantially the same, and the vertical rod member 22c1 is arranged in front of the vertical rod member 22c2 by approximately the width of the mast mechanism 7 in the regulation direction. Also, in the front-rear direction, the positions of the vertical rod member 22c3 and the vertical rod member 30v2 are substantially the same. Further, in the front-rear direction, the positions of the vertical rod member 22c4 and the vertical rod member 30v3 are substantially the same, and the vertical rod member 22c5 is arranged behind the vertical rod member 22c4 by approximately the width of the mast mechanism 7 in the regulation direction.

[0221] The front mast mechanism 7F is the first mast mechanism 7A whose regulation direction is the front-rear direction. The traveling side mast member 71 of the front mast mechanism 7F is attached and fixed to the left and right inner side surfaces of the mast attachment plate 30c1 extending forward from the front ends on the left and right inner sides of the vertical rod member 30v1.

[0222] On the other hand, the vehicle body side mast member 72 of the front mast mechanism 7F is attached to the regulating member 75 fixed to the vertical rod member 22c1 and the vertical rod member 22c2, and its front end edge and rear end edge are arranged along the regulating portions 74 at the front end and the rear end of the regulating member 75, and the front and rear movement is in a regulated state. The intermediate mast member 73 is arranged so as to be sandwiched between the traveling side mast member 71 and the vehicle body side mast member 72 in the left-right direction.

[0223] In the front mast mechanism 7F as the first mast mechanism 7A in which the mast member 70 is attached to the traveling frame 30 and the vehicle body side frame 22 as described above, restricting portions 74 are provided at the front edge and the rear edge of the mast member 70 so as to extend in the left-right direction.

[0224] The middle mast mechanism 7M is the second mast mechanism 7B whose restricting direction is the left-right direction. The traveling side mast member 71 of the middle mast mechanism 7M is fixedly attached to the front side surface of a mast mounting plate 30c2 that extends leftward and inward from the left and right inner ends of the vertical rod member 30v2.

[0225] On the other hand, the vehicle body side mast member 72 is attached to a restricting member 75 fixed to the vertical rod member 22c3, and its left end edge and right end edge are arranged along the restricting portions 74 at the left end and the right end of the restricting member 75, and are in a state where left-right movement is restricted. The intermediate mast member 73 is arranged so as to be sandwiched between the traveling side mast member 71 and the vehicle body side mast member 72 in the front-rear direction.

[0226] In the middle mast mechanism 7M as the second mast mechanism 7B in which the mast member 70 is attached to the traveling frame 30 and the vehicle body side frame 22 as described above, restricting portions 74 are provided at the left end edge and the right end edge of the mast member 70 so as to extend in the front-rear direction.

[0227] The rear mast mechanism 7R is the first mast mechanism 7A whose restricting direction is the front-rear direction. The traveling side mast member 71 of the rear mast mechanism 7R is fixedly attached to the left and right inner side surfaces of a mast mounting plate 30c3 that extends rearward from the rear ends on the left and right inner sides of the vertical rod member 30v3.

[0228] On the other hand, the vehicle body side mast member 72 of the rear mast mechanism 7R is attached to a restricting member 75 fixed to the vertical rod member 22c4 and the vertical rod member 22c5, and its front end edge and rear end edge are arranged along the restricting portions 74 at the front end and the rear end of the restricting member 75, and are in a state where front-rear movement is restricted. The intermediate mast member 73 is arranged so as to be sandwiched between the traveling side mast member 71 and the vehicle body side mast member 72 in the left-right direction.

[0229] In the rear mast mechanism 7R as the first mast mechanism 7A in which the mast member 70 is attached to the traveling frame 30 and the vehicle body side frame 22 as described above, restricting portions 74 are provided at the front edge and the rear edge of the mast member 70 so as to extend in the left-right direction.

[0230] Each mast mechanism 7 has a structure having strong rigidity in the restricting direction. That is, the first mast mechanism 7A has sufficient rigidity to resist the longitudinal load strongly applied during acceleration or deceleration of the work vehicle 1, for example, and the second mast mechanism 7B has sufficient rigidity to resist the lateral load strongly applied during turning of the work vehicle 1, for example.

[0231] Therefore, the front mast mechanism 7F, the middle mast mechanism 7M, and the rear mast mechanism 7R arranged in a front-rear row have rigidity capable of resisting both the load applied in the front-rear direction and the load applied in the left-right direction of the work vehicle 1 because the first mast mechanism 7A having the front-rear direction as the restricting direction and the second mast mechanism 7B having the left-right direction as the restricting direction are used in combination.

[0232] On the other hand, as shown in FIGS. 15, 16, 18, and 19, in the present embodiment, both the left front mast mechanism 7FL and the right front mast mechanism 7FR are the first mast mechanism 7A, and both the left rear mast mechanism 7RL and the right rear mast mechanism 7RR are the first mast mechanism 7A, and both the left middle mast mechanism 7ML and the right middle mast mechanism 7MR are the second mast mechanism 7B.

[0233] That is, the left and right mast mechanisms 7 having the same position in the front-rear direction are unified into either the first mast mechanism 7A or the second mast mechanism 7B. Thereby, difference in the direction of rigidity between the left and right mast mechanisms 7 is prevented from generating distortion stress or the like.

[0234] In the left-right direction of the work vehicle 1, all of the front mast mechanism 7F, the middle mast mechanism 7M, and the rear mast mechanism 7R arranged in the front-rear direction are disposed between the left and right outer ends of the vehicle body 2 and the left and right inner ends of each traveling structure 3 (traveling frame 30).

[0235] That is, none of the mast mechanisms 7 has a portion that penetrates into the vehicle body 2 or a portion that penetrates into the running structure 3, and it is interposed between the vehicle body 2 and the running structure 3, specifically, between the running frame 30 and the vehicle body side frame 22. Thereby, a wide free space can be secured in the left - right direction for mounting various devices on the upper portion of the upper frame portion 30u of the running frame 30 of the running structure 3.

[0236] Note that the positions of the front mast mechanism 7F, the middle mast mechanism 7M, and the rear mast mechanism 7R in the front - rear direction described above are just examples and are not limited thereto. Further, the plurality of mast mechanisms 7 arranged side - by - side in a row in the front - rear direction between each vehicle body side frame 22 and the running frame 30 on the corresponding side are not limited to three in the front, middle, and rear, and may be, for example, two in the front - rear direction or four or more.

[0237] Also, the restricting direction of the mast mechanism 7 is not limited only to the front - rear direction and the left - right direction as described above. For example, the restricting direction may be an oblique direction with respect to the front - rear direction or the left - right direction.

[0238] Next, with reference to FIGS. 2, 3, 6, etc., the layout of the front wheels 31F and the rear wheels 31R in the front - rear direction of the running structure 3 and the positional relationship with the vehicle body 2 will be described.

[0239] The work vehicle 1 includes running structures 3 provided on each of the left and right sides of the vehicle body 2. 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. 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 offset to one of the front and rear of the running frame 30.

[0240] In this configuration, either the front wheel 31F or the rear wheel 31R arranged front and rear in each traveling structure 3 may be defined as the first wheel 31, and either may be defined as the second wheel 31. In the present embodiment, the axle 31a of the front wheel 31F and the axle 31a of the rear wheel 31R are supported at a position biased toward the rear of the traveling frame 30, but it 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 a position biased toward the front of the traveling frame 30.

[0241] Also, the central portion (the portion of the front-rear intermediate position 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 the distance from the central portion (the portion of the front-rear intermediate position M) of the traveling frame 30 to the axle 31a of the first wheel 31 is shorter than the distance from the central portion (the portion of the front-rear intermediate position M) of the traveling frame 30 to the axle 31a of the second wheel 31.

[0242] In the present embodiment, the front wheel 31F is defined as the first wheel 31 and the rear wheel 31R is defined as the second wheel 31, and in the front-rear direction, the distance D1 from the front-rear intermediate position M between the front wheel 31F and the rear wheel 31R to the position A1 of the axle 31a of the front wheel 31F is shorter than the distance D2 from the front-rear intermediate position M to the position A2 of the axle 31a of the rear wheel 31R, but it is not limited to this. For example, the rear wheel 31R may be defined as the first wheel 31 and the front wheel 31F may be defined as the second wheel 31, and the distance from the front-rear intermediate position M to the axle 31a of the rear wheel 31R may be made shorter than the distance from the front-rear intermediate position M to the axle 31a of the front wheel 31F.

[0243] Also, of the front end and the rear end of the traveling frame 30, the one closer to the first wheel 31 is defined as the first end, and the one closer to the second wheel 31 is defined as 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.

[0244] In addition, in this embodiment, the front wheels 31F are used as the first wheels 31, and the rear wheels 31R are used as the second wheels 31. In the front-rear direction, the distance D3 from the axle 31a of the rear wheels 31R to the rear end of the traveling frame 30 is shorter than the distance D4 from the axle 31a of the front wheels 31F to the front end of the traveling frame 30. However, the present invention is not limited to this. For example, the rear wheels 31R may be used as the first wheels 31, and the front wheels 31F may be used as the second wheels 31, and the distance from the axle 31a of the front wheels 31F to the front end of the traveling frame 30 may be shorter than the distance from the axle 31a of the rear wheels 31R to the rear end of the traveling frame 30.

[0245] Further, the second wheels 31 protrude forward or backward from the second end of the traveling frame 30, and a mounting area S2 is formed between the left and right second wheels 31 in front of or behind the vehicle body 2.

[0246] The mounting area S2 is an area where a connecting device 6 for connecting the working device 200 to the vehicle body 2 is arranged when the connecting device 6 is mounted on the vehicle body 2.

[0247] In addition, in this embodiment, the front wheels 31F are used as the first wheels 31, and the rear wheels 31R are used as the second wheels 31. The rear wheels 31R protrude backward from the rear end of the traveling frame 30, and a mounting area S2 is formed between the left and right rear wheels 31R behind the vehicle body 2 (the rear main body case 26). However, the present invention is not limited to this.

[0248] For example, the rear wheels 31R may be used as the first wheels 31, and the front wheels 31F may be used as the second wheels 31. The front wheels 31F protrude forward from the front end of the traveling frame 30, and a mounting area S2 may be formed between the left and right front wheels 31F in front of the vehicle body 2.

[0249] Further, the vehicle body 2 is movable upward from the traveling structure 3. When the vehicle body 2 descends, the vehicle body 2 is arranged to be sandwiched between the left and right traveling structures 3L and 3R, and the mounting area S2 is formed between the left and right second wheels 31.

[0250] In this embodiment, the front wheels 31F are the first wheels 31, and the rear wheels 31R are the second wheels 31. When the vehicle body 2 descends, the mounting area S2 is formed between the left and right rear wheels 31R. However, the present invention is not limited to this. For example, the rear wheels 31R may be the first wheels 31, and the front wheels 31F may be the second wheels 31. When the vehicle body 2 descends, the mounting area S2 may be formed between the left and right front wheels 31F.

[0251] Of the front end and the rear end of the vehicle body 2, the side corresponding to the first end of the traveling frame 30 is the third end, and the side corresponding to the second end of the traveling frame 30 is the fourth end. The fourth end of the vehicle body 2 is disposed closer to the third end than the axles 31a of the left and right second wheels 31. Further, a connecting device 6 for connecting the working device 200 to the vehicle body 2 is disposed in the mounting area S2 and is mounted on the fourth end of the vehicle body 2.

[0252] In this embodiment, the first end of the traveling frame 30 is the front end of the traveling frame 30, and the corresponding third end of the vehicle body 2 is the front end of the vehicle body 2. Further, the second end of the traveling frame 30 is the rear end of the traveling frame 30, and the corresponding fourth end of the vehicle body 2 is the rear end of the vehicle body 2. That is, 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 disposed closer to the front end than the axles 31a of the left and right rear wheels 31R, and the connecting device 6 is mounted on the rear end of the vehicle body 2 in the mounting area S2 behind the vehicle body 2.

[0253] However, the above configuration is not limited thereto. 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 disposed closer to the rear end than the axles 31a of the left and right front wheels 31F, and the connecting device 6 may be mounted on the front end of the vehicle body 2 in the mounting area S2 in front of the vehicle body 2.

[0254] The above configuration will be specifically described below with reference to FIGS. 2, 3, 6, etc.

[0255] The traveling frame 30 of each traveling structure 3 is not symmetrically configured with respect to the front wheels 31F and the rear wheels 31R, and the front wheels 31F and the rear wheels 31R are disposed biased rearwardly in the traveling frame 30.

[0256] The longitudinal intermediate position M between the front end and the rear end of the traveling frame 30, that is, the position where the distance from the front end of the traveling frame 30 is equal to the distance from the rear end, is between the front wheels 31F and the rear wheels 31R in the longitudinal direction.

[0257] Here, due to the rearward-biased arrangement of the front wheels 31F and the rear wheels 31R in the traveling frame 30 as described above, as shown in FIGS. 2 and 3, in the longitudinal direction, the distance D1 from the longitudinal intermediate position 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 longitudinal intermediate position M to the position A2 of the axle 31a of the rear wheel 31R behind it.

[0258] Furthermore, due to the rearward-biased arrangement of the front wheels 31F and the rear wheels 31R as described above, in the longitudinal direction, the distance D3 between the position E2 of the rear end of the traveling frame 30 and the position A2 of the axle 31a of the rear wheel 31R is shorter than the distance D4 between the position E1 of the front end of the traveling frame 30 and the position A1 of the axle 31a of the front wheel 31F. In this embodiment, the rear end of the rear wheel 31R protrudes rearward from the rear end of the traveling frame 30. Further, in this embodiment, the axle 31a of the rear wheel 31R is disposed in front of the rear end of the traveling frame 30 and behind the rear end of the rear main body case 26.

[0259] In relation to the rearward-biased arrangement of the front wheels 31F and the 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 forward of the rear wheels 31R of the traveling structure 3 in the longitudinal direction. In this embodiment, the rear end of the rear main body case 26 is disposed in front of the axle 31a of the rear wheel 31R. Note that the rear end of the rear main body case 26 and the axle 31a of the rear wheel 31R may be substantially at the same position in the longitudinal direction.

[0260] As shown in FIG. 5 and the like, brackets 26a and 26b for mounting the connecting device 6 are provided at the rear end of the rear body case 26 as described above. As shown in FIG. 6, the space (area) behind the rear body case 26 is a mounting area S2 for arranging the connecting device 6 mounted on the rear end of the rear body case 26, that is, for mounting the working device 200 on the vehicle body 2.

[0261] The vehicle body 2 is lowered in a normal state and is sandwiched between the left and right traveling structures 3 as shown in FIGS. 2 and 3. In this state, the mounting area S2 behind the rear body case 26 is secured between the axles 31a of the left rear wheel 31RL and the right rear wheel 31RR.

[0262] That is, in the mounting area S2 behind the rear body case 26, a slightly front area is sandwiched between the left and right traveling frames 30L and 30R and the left - right width is slightly narrowed, but most of it is sandwiched between the left and right rear wheels 31RL and 31RR that protrude rearward from the rear end of the traveling frame 30. So, a wide left - right width corresponding to the vehicle width of the rear wheel 31R is secured. That is, the mounting area S2 is a space that widens rearward and is a good arrangement space for the three - point link structure connecting device 6.

[0263] Also, since the mounting area S2 is sandwiched (covered) between the left rear wheel 31RL and the right rear wheel 31RR in a wide range in the front - rear direction, most of the connecting 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 - rear direction. That is, as shown in FIGS. 2 and 3, when viewed from the side, most of the connecting device 6 is hidden by the rear wheel 31R, and protection can be ensured.

[0264] Note that the work vehicle 1 can also be configured such that, for example, by making it possible to mount the connecting device 6 on the front body case 24, etc., it is also possible to have a structure in which a connecting device for the working device is mounted in front of the vehicle body 2.

[0265] In this case, in the traveling frame 30, it is also conceivable to support the front wheels 31F and the rear wheels 31R so as to be biased forward, so that most of the coupling device 6 disposed in front of the vehicle body 2 can be covered by the left and right front wheels 31F.

[0266] 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 the rear wheels 31R, etc., from that described above.

[0267] Next, the configuration of the control system in the work vehicle 1 will be described with reference to FIG. 8. As shown in FIG. 8, the work vehicle 1 is provided with a positioning device 11. The positioning device 11 can detect the position of the vehicle body 2 (positioning information including latitude and longitude) by a satellite positioning system (positioning satellite) such as D-GPS, GPS, GLONASS, Beidou, Galileo, or Michibiki. That is, the positioning device 11 receives a satellite signal (position of the positioning satellite, transmission time, correction information, etc.) transmitted from the positioning satellite, and detects the position of the vehicle body 2 (for example, latitude and longitude) based on the satellite signal.

[0268] The positioning device 11 includes a receiving device 12 and an inertial measurement unit (IMU) 13. The receiving device 12 is a device that has an antenna or the like and receives a satellite signal transmitted from a positioning satellite, and is attached to the vehicle body 2. The inertial measurement unit 13 includes 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. Incidentally, the yaw angle may be detected by installing a plurality of positioning devices 11.

[0269] As shown in FIG. 8, the work vehicle 1 is provided with a communication device 14. The communication device 14 includes a communication circuit for performing communication via an in-vehicle network and a wireless communication circuit for performing wireless communication. The wireless communication circuit can directly or indirectly communicate wirelessly with an external device by communication standards such as Wi-Fi (Wireless Fidelity, registered trademark) of the IEEE802.11 series, BLE (Bluetooth (registered trademark) Low Energy), LPWA (Low Power, Wide Area), LPWAN (Low-Power Wide-Area Network), etc.

[0270] As another example, for instance, a communication circuit capable of wirelessly communicating with an external device may be provided in the communication device 14 by means of a mobile phone communication network, a data communication network, or the like. The external device is, for example, a personal computer, a smartphone, a tablet computer, a PDA, or a server, etc.

[0271] As shown in FIG. 1 etc., the work vehicle 1 is provided with at least one situation detection device 10. The work vehicle 1 according to the present embodiment is mounted on the upper surface of the flat plate portion 23a of the support member 23 that is attached to the lower surface of the vehicle body central frame 21 and supports the front body case 24, and stands so as to protrude upward from the upper end of the vehicle body central frame 21 through the open space between the left and right main rod members 21a and the front and rear horizontal cylinder members 21b of the vehicle body central frame 21.

[0272] Note that the mounting (support) position of the situation detection device 10 on the work vehicle 1 is not limited to the position shown in FIG. 1 etc., and it may be supported, for example, at other parts of the vehicle body frame structure 20 of the vehicle body 2, or at the traveling frame 30 of the traveling structure 3, etc.

[0273] Also, a plurality of 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 of the others may be provided on the traveling structure 3.

[0274] 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 movable along the rail. Also, the moving direction 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.

[0275] As shown in FIG. 8, the situation detection device 10 includes a camera (imaging device) 10a, a sensor 10b, and a calculation unit 10c. In the case of this embodiment, the situation detection device 10 includes both the camera 10a and the sensor 10b, but it may include only one of them.

[0276] The camera 10a is composed of 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.

[0277] The camera 10a only needs to be able to image at least one direction including the traveling direction of the work vehicle 1 among the front, rear, left, and right of the work vehicle 1. Preferably, the camera 10a is configured such that, for example, in the situation detection device 10, the angle can be changed in the horizontal direction and the vertical direction, and the imaging direction can be changed both vertically and horizontally. Also, the imaging position can be moved by the movement of the situation detection device 10 as described above.

[0278] The camera 10a images the periphery of the work vehicle 1 and generates an image signal. The calculation unit 10c is composed of a computer or the like including a signal processing circuit that processes the generated image signal. The signal processing circuit detects the state of the object (such as the presence or absence of the object, the position of the object, the type of the object, the size of the object, etc.) based on the image signal output from the camera 10a.

[0279] Sensor 10b is an optical sensor and is composed of, for example, a LiDAR (Light Detection And Ranging).

[0280] The LiDAR (laser sensor) irradiates pulsed measurement light (laser light) millions of times per second from a light source such as a laser diode, and scans horizontally or vertically by reflecting the measurement light with a rotating mirror, and projects it onto a predetermined detection range (sensing range).

[0281] Then, the LiDAR receives the reflected light of the measurement light by the object with a light receiving element. The signal processing circuit of the calculation unit 10c detects the state of the object (presence or absence of the object, position of the object, type of the object, size of the object, etc.) based on the light reception signal output from the light receiving element of the LiDAR.

[0282] Also, the signal processing circuit detects the distance to the object based on the time from when the measurement light is irradiated by the LiDAR until the reflected light is received (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.

[0283] The optical sensor 10b may additionally be provided with an acoustic sensor in order to improve the detection accuracy, etc.

[0284] The acoustic sensor is composed of, for example, an airborne ultrasonic sensor such as a sonar. The airborne ultrasonic sensor transmits a measurement wave (ultrasonic wave) to a predetermined detection range by a transmitter, and receives the reflected wave of the measurement wave reflected by the object with a receiver. The signal processing circuit detects the state of the object (presence or absence of the object, position of the object, type of the object, size of the object, etc.) based on the signal output from the receiver.

[0285] Also, the signal processing circuit detects the distance to the object based on the time from when the measurement wave is transmitted by the airborne ultrasonic sensor until the reflected wave is received (TOF (Time of Flight) method). Note that the method for detecting the distance by the acoustic sensor may be a method other than the TOF method.

[0286] 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). The situation detection device 10 detects, as the situation around the work vehicle 1, obstacle information indicating whether there are no obstacles or persons in the vicinity of the work vehicle 1 that may come into contact.

[0287] The situation detection device 10 also detects, as the situation around the work vehicle 1, road information which is information regarding the road on which the left and right traveling structures 3 can travel. Specifically, it detects road information which is a value regarding the road on which the traveling structure 3 can travel. The situation detection device 10 detects, as road information, for example, the width of the traveling road.

[0288] The width of the traveling road detected by the situation detection device 10 is the width of the object that the work vehicle 1 attempts to straddle and travel between the left traveling structure 3L and the right traveling structure 3R. The situation detection device 10 detects, as the width of the traveling road, for example, the width of the ridges provided on the ground, or the width of the obstacles that impede travel existing on the ground.

[0289] Also, the situation detection device 10 detects, as road information, for example, the height of the traveling road. The height of the traveling road detected by the situation detection device 10 is the height of the object that the vehicle body 2 attempts to straddle and travel between the left traveling structure 3L and the right traveling structure 3R. The situation detection device 10 detects, as the height of the traveling road, for example, the height of the ridges provided on the ground, or the height of the obstacles that impede travel existing on the ground.

[0290] Obstacles that impede travel are, for example, grooves or holes formed on 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 the crops planted on the ground as the height of the obstacle.

[0291] 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 are in contact with the ground to the upper end of the crop. For example, when the crop is planted in ridges, since the wheels 31 of the traveling structure 3 are in contact with the ground between the ridges rather than on the ridges, the height of the crop detected by the situation detection device 10 is "the height of the crop itself + the height of the ridge".

[0292] The situation detection device 10 may detect the inclination of the ground in the left - right direction as a 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 a situation around the work vehicle 1. Therefore, the situation detection device 10 may be mounted on each of the left traveling frame 30L and the right traveling frame 30R.

[0293] Also, in this case, as the situation detection device 10, 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. Also, a camera 10a may be used as the situation detection device 10, and the calculation unit 10c may be configured to detect the inclination of the ground in the left - right direction based on the image captured by the camera 10a.

[0294] Furthermore, in addition to the situation detection device 10 that detects the situation around the work vehicle 1, the work vehicle 1 is provided with a detection device that detects the state of the work vehicle 1 itself.

[0295] In FIG. 8, as a detection device that detects the state of the work vehicle 1 itself, a distance detection device 16 that detects the left - right direction distance between the left traveling structure 3L and the right traveling structure 3R corresponding 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 point of the wheel 31 to the lowest part of the vehicle body 2, are illustrated. In addition, it is conceivable that 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 wheel 31, etc. are provided.

[0296] As shown in FIG. 8, the control device 15 provided in the work vehicle 1 is a device that performs various controls on the work vehicle 1. The control device 15 includes a calculation unit (such as a CPU) and a storage unit (such as a RAM and a ROM). The storage unit may include an external memory provided outside the control device 15. The control device 15 is connected to various devices and mechanisms shown in FIG. 8 via an in-vehicle LAN (in-vehicle network) such as a CAN (Controller Area Network) or a communication line.

[0297] 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.

[0298] 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. The functions of these control units are realized by the calculation unit executing a predetermined control program stored in the storage unit.

[0299] 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 automatic driving control.

[0300] In the line-type automatic driving control, the automatic driving control unit 15A controls the inverter 38 for output control of the traveling motor 33 of each wheel unit 4 so that the work vehicle 1 (the vehicle body 2) moves along a preset planned traveling line, controls the rotation speed of the corresponding wheel 31, and 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.

[0301] In the autonomous automatic driving control, based on the result of detecting the position of the work vehicle 1 (vehicle body 2) by the positioning device 11, the automatic driving control unit 15A performs settings such as the traveling direction (steering direction) and vehicle speed (speed) of the vehicle body 2, and controls the inverter 38 for output control of the traveling motor 33 of each wheel unit 4 so as to achieve the set steering angle (direction) and vehicle speed, thereby controlling the rotation speed of the corresponding wheel 31. Also, the control valve unit 27 (control valve) for controlling the extension amount of the steering cylinder 35 of each wheel unit 4 is controlled to control the direction (steering angle) of the corresponding wheel 31.

[0302] Note that the line-type automatic driving control and the autonomous automatic driving control may be switchable by a switch or the like. Also, the automatic driving control unit 15A may be configured to be capable of executing either one of the line-type automatic driving control and the autonomous automatic driving control. Note that the configuration of the automatic driving control unit 15A is not limited to the above-described configuration.

[0303] Furthermore, based on the obstacle information obtained by the situation detection device 10 sensing (detecting an object) the surroundings of the work vehicle 1, the automatic driving control unit 15A determines whether the stopped work vehicle 1 should start, whether the traveling work vehicle 1 should stop, or whether it should steer to change the traveling direction, or whether the drive of the working device 200 during work should be stopped, and / or whether the working device 200 should be raised, etc., and controls the inverter 38 for output control of the traveling motor 33, the steering cylinder 35, or the inverter 54 for output control of the electric motor 53, etc. in the traveling structure 3 to realize the determined state.

[0304] As described above, since the control device 15 of the work vehicle 1 includes the automatic driving control unit 15A, the work vehicle 1 can perform automatic driving (driverless driving) without the operator boarding. Therefore, the work vehicle 1 of the illustrated embodiment does not have a driver's seat for the operator to sit on.

[0305] However, the work vehicle 1 may be a vehicle on which an operator rides to perform automatic driving. Alternatively, the work vehicle 1 may be a vehicle on which an operator rides and drives to travel. When the work vehicle 1 is a vehicle on which an operator rides, a driver's seat is provided on the vehicle body 2.

[0306] Based on information regarding the width of the traveling road included in the road information acquired by detection of the situation detection device 10, information regarding the distance between the left traveling structure 3L and the right traveling structure 3R detected by the distance detection device 16, etc., the distance change control unit 15B of the control device 15 controls the control valve unit 27 (control valve) for expanding and contracting the width change cylinders 8A and / or 8B as the vehicle body deformation device so that the distance between the left traveling structure 3L and the right traveling structure 3R corresponds to the width of the traveling road where the distance is detected, that is, so that the left and right wheels 31 are correctly arranged in the furrow.

[0307] Based on information regarding the height of the traveling road included in the road information acquired by detection of the situation detection device 10, information regarding the vehicle height detected by the vehicle height detection device 17, etc., the height change control unit 15C of the control device 15 controls the control valve unit 27 (control valve) for expanding and contracting the vehicle body lifting cylinder 9 as the vehicle body moving device so that the vehicle height, which is the vertical distance from the ground contact point of the wheel 31 to the bottom end of the vehicle body 2, corresponds to the height of the detected traveling road, that is, so that the vehicle body 2 straddles crops or the like growing on the traveling road.

[0308] Further, based on information regarding the left-right inclination of the ground acquired by detection of the situation detection device 10, etc., the height change control unit 15C of the control device 15 controls the control valve unit 27 (control valve) for expanding and contracting the left vehicle body lifting cylinder 9L and the right vehicle body lifting cylinder 9R as the vehicle body moving device to adjust the difference in the piston rod extension amounts of the left vehicle body lifting cylinder 9L and the right vehicle body lifting cylinder 9R so as to adjust the left-right inclination of the vehicle body 2.

[0309] In addition, the position change control unit 15D of the control device 15 measures the slip ratios of the front wheels 31F and the rear wheels 31R from the detection results of a rotation speed detection device that detects the rotation speed of the wheels 31, for example. If the slip ratio of the front wheels 31F is high, for example, it is conceivable to cause an external device to display a warning to move the front main body case 24 forward via the communication device 14.

[0310] Further, when the work vehicle 1 is provided with a battery moving actuator 81 (vehicle body deformation device 80) for moving the front main body case 24 back and forth as shown in FIG. 8, the position change control unit 15D operates the battery moving actuator 81 so as to move the front main body case 24 (when the battery moving actuator 81 is a hydraulic actuator, the corresponding control valve is controlled).

[0311] The operation or effect of each component of the work vehicle 1 described above will be described below.

[0312] (Item A1) A work vehicle 1 including a vehicle body 2, wheels 31 provided on the side of the vehicle body 2, and a traveling frame 30 provided on the side of the vehicle body 2 and supporting the wheels 31, wherein the traveling frame 30 has an upper frame portion 30u disposed above the wheels 31 and has a space for arranging devices above the upper frame portion 30u.

[0313] With the above configuration, a wide space for arranging devices is secured above the upper frame portion 30u of the traveling frame 30 provided on the side of the vehicle body 2 and disposed above the wheels 31. In this way, a wide space is formed at a location where it is difficult to secure space in a normal vehicle, and devices such as a traveling motor 33 for driving each wheel 31 and a liquid tank used for spraying work can be arranged in this space. In addition, since such devices can be arranged in this space, space for arranging other devices can be secured in other parts of the vehicle, which can contribute to the compactness of the entire vehicle and the improvement of the degree of freedom in the layout of the devices.

[0314] (Item A2) The wheel 31 includes a front wheel 31F and a rear wheel 31R, and the upper frame portion 30u includes a front portion provided above the front wheel 31F and a rear portion provided above the rear wheel 31R. The working vehicle 1 according to item A1 having a space for arranging equipment at the upper part of the front portion and the upper part of the rear portion.

[0315] With the above configuration, when the front wheel 31F and the rear wheel 31R are provided on the side of the vehicle body 2, a space for arranging equipment can be secured above the front wheel 31F and above the rear wheel 31R on the side of the vehicle body 2, and the effects as described above can be enjoyed.

[0316] (Item A3) The upper frame portion 30u is provided so as to extend from above the front wheel 31F to above the rear wheel 31R, and the space for arranging equipment is provided in a range extending from above the front wheel 31F to above the rear wheel 31R. The working vehicle 1 according to claim A2.

[0317] With the above configuration, on the side of the vehicle body 2, a wide and continuous space for arranging equipment can be secured from above the front wheel 31F to above the rear wheel 31R, and the effects as described above can be enjoyed.

[0318] (Item A4) The vehicle body 2 is movable relative to the traveling frame 30 in the vertical direction, and the vehicle body 2 does not have a portion that interferes with the space for arranging equipment during the relative movement in the vertical direction with respect to the traveling frame 30. The working vehicle 1 according to any one of items A1 to A3.

[0319] With the above configuration, also in the working vehicle 1 having a structure in which the vehicle body 2 is movable relative to the traveling frame 30 in the vertical direction, since the vehicle body 2 does not have a portion that interferes with the space for arranging equipment above the upper frame portion 30u of the traveling frame 30 due to its vertical movement, equipment can be arranged in the space without worrying about the vertical movement of the vehicle body 2, and the effects as described above can be enjoyed.

[0320] (Item A5) The work vehicle 1 according to any one of items A1 to A4, comprising a lifting device 9 that moves the vehicle body 2 in the vertical direction inside the traveling frame 30 in the left-right direction.

[0321] With the above configuration, since the lifting device (vehicle body lifting cylinder 9) is arranged inside the traveling frame 30 in the left-right direction, a wide space for equipment arrangement that is not invaded by the lifting device (vehicle body lifting cylinder 9) is secured above the upper frame portion 30u of the traveling frame 30.

[0322] (Item A6) The traveling frame 30 has a lower frame portion 30b between the front wheels 31F and the rear wheels 31R below the upper frame portion 30u, and between the front wheels 31F and the rear wheels 31R on the side of the vehicle body 2, there is a space for equipment arrangement between the upper frame portion 30u and the lower frame portion 30b of the traveling frame 30. The work vehicle 1 according to any one of items A2 to A5.

[0323] With the above configuration, the traveling frame 30 that provides a space for equipment arrangement by the upper frame portion 30u has a 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. Thus, 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 a space for equipment arrangement, and since equipment and the like can be arranged in these spaces, for example, in other parts of the work vehicle 1, a space for installing other equipment can be secured, which can contribute to the compactification of the entire work vehicle 1 and the improvement of the degree of freedom in the layout of the equipment.

[0324] (Item A7) The vehicle body 2 is connected to the traveling frame 30 so as to be relatively movable in the vertical direction. The work vehicle 1 according to any one of items A2 to A6.

[0325] With the above configuration, while the traveling frame 30 is connected to the vehicle body 2 so as to be relatively movable in the vertical direction, it has no portion that interferes with the space above the upper space portion 30u by the vertical movement as described above. Therefore, a space with a sufficiently wide width in the left-right direction can be secured on at least one side of the left and right of the vehicle body 2.

[0326] (Item A8) The work vehicle 1 according to item A7, wherein the vehicle body 2 has no portion that vertically overlaps with the upper frame portion 30u of the traveling frame 30 when disposed at the lowest position within the relative movement range in the vertical direction with respect to the traveling frame 30.

[0327] With the above configuration, when the vehicle body 2 is disposed at the lowest position, it has no portion that vertically overlaps with the upper frame portion 30u of the traveling frame 30. Thus, such a portion does not narrow the space for equipment arrangement above the upper frame portion 30u, and the equipment supported by the vehicle body 2 can be disposed as low as possible within the desired range.

[0328] (Item A9) The work vehicle 1 according to item A7 or item A8, wherein the vehicle body 2 is connected to the traveling frame 30 via a mast mechanism 7 disposed inside the traveling frame 30 in the left-right direction.

[0329] With the above configuration, by being connected to the traveling frame 30 by the mast mechanism 7, the vehicle body 2 can move vertically with respect to the traveling frame 30 in a stable state without shaking. Further, since this mast mechanism 7 is disposed inside the traveling frame 30 in the left-right direction, a wide space for equipment arrangement that is not invaded by the vehicle body lifting cylinder 9, which is a lifting device, is secured above the upper frame portion 30u of the traveling frame 30.

[0330] (Item A10) The wheel 31 and the traveling frame 30 are provided on the left side and the right side 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. The work vehicle 1 according to any one of Items A1 to A9.

[0331] With the above configuration, the front wheels 31F, the rear wheels 31R and the traveling frame 30 are provided on each of the left and right sides, and the work vehicle 1 having a structure including the vertically movable vehicle body 2 disposed between the left traveling frame 30L and the right traveling frame 30R. Spaces for installing equipment can be secured above the front wheels 31FL and the rear wheels 31RL on the left side of the vehicle body 2 and between the front wheels 31FL and the rear wheels 31RL, and also above the front wheels 31FR and the rear wheels 31RR on the right side of the vehicle body 2 and between the front wheels 31FR and the rear wheels 31RR. Thus, a work vehicle 1 with a high degree of freedom in the layout of equipment can be provided.

[0332] (Item B1) A work vehicle 1 comprising a vehicle body 2 movable in the vertical 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 side and the right side of the vehicle body 2, and a moving mechanism 9 for moving the vehicle body 2 in the vertical direction. The vehicle body 2 has a space portion S1 formed at least between the first device and the second device. In the state where the vehicle body 2 is lowered to the maximum extent, the moving mechanism 9 positions the space portion S1 between at least the first device and the second device and between the left and right traveling structures 3L, 3R. In the state where the vehicle body 2 is raised to the maximum extent, the moving mechanism 9 positions the space portion S1 between at least the first device and the second device and above the left and right traveling structures 3L, 3R.

[0333] With the above configuration, a space S1 that can be used for various purposes, such as maintenance of equipment, is secured in the vehicle body 2. In the normal state where the vehicle body 2 is lowered, the equipment installed in the vehicle body 2 can be covered and protected by the traveling structure 3 by using the space S1. When the vehicle body 2 is raised, the space S1 is located above the left traveling structure 3L and the right traveling structure 3R, and it is possible for an operator to access the space S1, such as by putting a hand into the space S1, for maintenance.

[0334] (Item B2) The work vehicle 1 according to Item B1, wherein the vehicle body 2 has the space S1 behind the first equipment mounted on the front portion of the vehicle body 2.

[0335] With the above configuration, for example, in the work vehicle 1 having a structure in which a work device 200 is connected to the rear portion of the vehicle body 2, when a first device, which is a heavy object such as a battery 50, is mounted on the front portion or the like of the vehicle body 2 in consideration of the weight balance with the work device 200, a space S1 that can be used for various purposes can be secured behind the first device.

[0336] (Item B3) The work vehicle 1 according to Item B2, wherein the vehicle body 2 has the space S1 between the first equipment and the second equipment mounted on the rear portion of the vehicle body 2.

[0337] With the above configuration, for example, in the work vehicle 1 having a structure in which a work device 200 is connected to the rear portion of the vehicle body 2, it is necessary to mount a PTO device such as a PTO shaft 5 for driving the work device and a lift cylinder 61 or the like, which is a hydraulic device for raising and lowering the work device 200, on the rear portion of the vehicle body 2. However, a long space is generated behind the first device mounted on the vehicle body 2, and even when a second device such as a PTO device or a hydraulic device like the PTO shaft 5 is mounted on the rear portion of the vehicle body 2, a space S1 can be secured between the first device and the second device, and this space can be made into a space S1 that can be used for various purposes.

[0338] (Item B4) The vehicle body 2 is configured such that the first device can be moved back and forth, and the vehicle body 2 can be switched between a state having the space portion S1 and a state not having the space portion S1 by the position change of the first device. The work vehicle 1 according to any one of items B1 to B3.

[0339] With the above configuration, for example, in the work vehicle 1 that can be changed in specification between a specification in which the work device 200 can be connected to the rear part of the vehicle body 2 and a specification in which the work device 200 is not connected, considering the weight balance and the like corresponding to the specification change and the like, the first device such as the battery 50 can be arranged at an optimal position in the vehicle body 2, and by changing the position, the vehicle body 2 can be switched between a state having the space portion S1 as a multi-purpose space and a state not having it. That is, in the vehicle body 2, by moving the position of the first device forward or the like, a space portion S1 that can be used as a multi-purpose space can be created.

[0340] (Item C1) The work vehicle 1 includes traveling structures 3 provided on each of the left and right sides of the vehicle body 2. The traveling structure 3 has a first wheel 31, a second wheel 31 in front of or behind the first wheel 31, and a traveling frame 30 that supports the axle 31a of the first wheel 31 and the axle 31a of the second wheel 31. The traveling frame 30 supports the axle 31a of the first wheel 31 and the axle 31a of the second wheel 31 at a position offset to one of the front and rear of the traveling frame 30.

[0341] By providing the traveling structure 3 having the traveling frame 30 that supports the front wheel 31F and the rear wheel 31R so as to be offset to one of the front and rear on the side of the vehicle body 2, there is a possibility of securing a space between the end of the vehicle body 2 corresponding to the one end of the traveling frame 30 and the axle 31a of the front wheel 31F and the rear wheel 31R that is closer to the one end of the traveling frame 30. Using the space, a connecting device 6 for connecting the work device 200 can be mounted on the vehicle body 2 at a position protected by the wheel 31.

[0342] (Item C2) The central part 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 the distance D1 from the central part M of the traveling frame 30 to the axle 31a of the first wheel 31 is shorter than the distance D2 from the central part M of the traveling frame 30 to the axle 31a of the second wheel 31. The work vehicle 1 described in item C1.

[0343] With the above configuration, the front wheels 31F and the rear wheels 31R can be supported while being offset to one of the front end or the rear end of the traveling frame 30, and the first wheels 31 and the second wheels 31 are the front wheels 31F and the rear wheels 31R that are offset to one side from the central part of the traveling frame 30. Among the axles 31a of the wheels, there is a possibility that a mounting area S2 can be secured between the end part (rear end part) of the vehicle body 2 corresponding to the axle 31a of the second wheel 31 (rear wheel 31R) with the longer distance from the front-rear intermediate position M and the left and right second wheels 31 (left rear wheel 31RL and right rear wheel 31RR). Using the mounting area S2, a connecting device 6 for connecting the work device 200 can be mounted on the vehicle body 2 at a position protected by the second wheel 31 (rear wheel 31R).

[0344] (Item C3) Of the front end and the rear end of the traveling frame 30, the side closer to the first wheel 31 is the first end, and the side closer to the second wheel 31 is the second end. The distance D3 from the axle 31a of the second wheel 31 to the second end is shorter than the distance D4 from the axle 31a of the first wheel 31 to the first end. The work vehicle 1 described in item C1 or C2.

[0345] With the above configuration, the front wheels 31F and the rear wheels 31R can be supported while being offset to one of the front end or the rear end of the traveling frame 30, and there is a possibility that a space can be secured between the end part of the vehicle body 2 corresponding to the one end part of the traveling frame 30 and the wheel 31 closer to the one end of the traveling frame 30 among the front wheels 31F and the rear wheels 31R. Using the space, a connecting device 6 for connecting the work device 200 can be mounted on the vehicle body 2 at a position protected by the wheel 31.

[0346] (Item C4) The second wheel 31 protrudes forward or backward 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. The work vehicle 1 according to item C3.

[0347] With the above configuration, a mounting area S2 is secured between the left and right second wheels 31 (left rear wheel 31RL and right rear wheel 31RR) at the front or rear of the vehicle body 2. The front-rear distance D3 between the second end (rear end) of the traveling 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 from the second end (rear end) of the traveling frame 30. Therefore, the mounting area S2 surrounded by the end of the vehicle body 2 and the left and right second wheels 31 (left rear wheel 31RL and right rear wheel 31RR) is fan-shaped in plan view, and is a suitable space for arranging a three-point link type connecting device 6 and the like.

[0348] (Item C5) The vehicle body 2 is movable upward from the traveling structure 3, and when the vehicle body 2 is lowered, the vehicle body 2 is arranged to be sandwiched between the left and right traveling structures 3L and 3R, and the mounting area S2 is formed between the left and right second wheels 31. The work vehicle 1 according to item C4.

[0349] With the above configuration, in the vehicle body 2 that can move up and down, the mounting area S2 in front of or behind 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 in the lowered state during normal times.

[0350] (Item C6) A connecting device 6 for connecting the working device 200 to the vehicle body 2 is disposed in the mounting area S2 and is mounted on the vehicle body 2. The work vehicle 1 according to item C4 or C5.

[0351] 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, such a connecting device 6 will be covered by the left and right second wheels (rear wheels 31R), and the protection of the connecting device 6 can be enhanced.

[0352] (Item C7) Of the front end and the rear end of the vehicle body 2, the side corresponding to the first end of the traveling frame 30 is defined as the third end, and the side corresponding to the second end of the traveling frame 30 is defined as the fourth end. The work vehicle 1 according to any one of Items C4 to C6, wherein the fourth end of the vehicle body 2 is disposed closer to the third end than the axles 31a of the left and right second wheels 31.

[0353] With the above configuration, a mounting region S2 is secured between the left and right second wheels 31 (left rear wheel 31RL and right rear wheel 31RR) in front of or behind the vehicle body 2. The distance in the front-rear direction between the second end (rear end) of the traveling frame 30 and the axles 31a of the second wheels 31 (left rear wheel 31RL and right rear wheel 31RR) is short, and the mounting region S2 between the axles 31a of the left and right second wheels 31 (left rear wheel 31RL and right rear wheel 31RR) that spreads in front of or behind the fourth end (rear end) of the vehicle body 2 is fan-shaped in plan view, which is a suitable space for arranging a three-point link type connecting device 6 or the like.

[0354] (Item C8) The work vehicle 1 according to Item C7, wherein a connecting device 6 for connecting a work device 200 to the vehicle body 2 is disposed within the mounting region S2 and is mounted on the fourth end of the vehicle body 2.

[0355] With the above configuration, the work device 200 can be connected to the vehicle body 2 via the connecting device 6 provided within the mounting region S2. Further, such a connecting device 6 will be covered by the left and right second wheels 31 (left rear wheel 31RL and right rear wheel 31RR), and the protectiveness of the connecting device 6 can be enhanced.

[0356] (Item D1) The work vehicle 1 includes: the vehicle body 2 movable in the vertical direction; a traveling structure 3 provided on the side of the vehicle body 2; a first member 71 attached to the traveling structure 3; a second member 72 attached to the vehicle body 2 and movable in the vertical direction along the first member 71 to raise and lower the vehicle body 2; and a plurality of mast mechanisms 7 each having a restricting portion 74 that restricts the movement of the second member 72 in a direction intersecting the vertical direction. The plurality of mast mechanisms 7 include a first mast mechanism 7A and a second mast mechanism 7B attached to the traveling structure 3 and the vehicle body 2 such that the restricting directions of the respective restricting portions 74 are different from each other.

[0357] With the above configuration, the plurality of mast mechanisms 7 include the first mast mechanism 7A and the second mast mechanism 7B having different restricting directions of the restricting portion 74, so that the first mast mechanism 7A has good rigidity against the load applied in the restricting direction, and the second mast mechanism 7B also has good rigidity against the load applied in the restricting direction, resulting in high durability. By providing such a plurality of mast mechanisms 7, it is possible to avoid the concentrated application of load in one direction to the work vehicle 1, and improve the durability of various parts of the work vehicle 1, such as the mast mechanism 7, the vehicle body 2, and the traveling structure 3.

[0358] (Item D2) The work vehicle 1 according to Item D1, wherein the first mast mechanism 7A is attached to the traveling structure 3 and the vehicle body 2 such that the restricting portion 74 restricts the movement of the second member 72 in the front-rear direction, and the second mast mechanism 7B is attached to the traveling structure 3 and the vehicle body 2 such that the restricting portion 74 restricts the movement of the second member 72 in the left-right direction.

[0359] With the above configuration, the first mast mechanism 7A has high rigidity against the longitudinal load of the work vehicle 1 that strongly acts during sudden acceleration or sudden stop of the work vehicle 1. On the other hand, the second mast mechanism 7B has high rigidity against the lateral load of the work vehicle 1 that strongly acts during sudden turning of the work vehicle 1. By including both the first mast mechanism 7A and the second mast mechanism 7B, the plurality of mast mechanisms 7 have good rigidity against both the longitudinal load and the lateral load of the work vehicle 1, and are highly durable.

[0360] (Item D3) The work vehicle 1 according to item D1 or D2, wherein on the left side or the right side of the vehicle body 2, the plurality of mast mechanisms 7 including the first mast mechanism 7A and the second mast mechanism 7B are arranged in parallel in the front-rear direction.

[0361] With the above configuration, on the left side or the right side of the vehicle body 2, in the front-rear direction that is the longitudinal direction of the work vehicle 1, a plurality of mast mechanisms 7 including the first mast mechanism 7A and the second mast mechanism 7B are arranged in parallel. Therefore, the left side portion or the right side portion of the vehicle body 2 in the work vehicle 1 can be made into a structure with high durability against the above-described loads.

[0362] (Item D4) The work vehicle 1 according to 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 portion, the rear portion, and the front-rear intermediate portion between the front portion and the rear portion on the left side or the right side of the vehicle body 2.

[0363] With the above configuration, on the left side or the right side of the vehicle body 2, the vehicle body 2 can be firmly supported by a plurality of mast mechanisms 7 (front mast mechanism 7F, middle mast mechanism 7M, rear mast mechanism 7R) provided at the front portion, the rear portion, and the front-rear intermediate portion so as to be vertically movable with respect to the traveling structure 3.

[0364] (Item D5) The work vehicle 1 according to item D4, wherein a first mast mechanism 7A is provided in each of the front part and the rear part, and a second mast mechanism 7B is provided in the front-rear intermediate part.

[0365] With the above configuration, on the left or right side of the vehicle body 2, a first mast mechanism 7A having a structure that restricts the forward and backward movement of the vehicle body side mast member 72 is provided at the front part and the rear part, thereby ensuring rigidity against loads in the direction that is likely to be applied to the front part and the rear part. A second mast mechanism 7B having a structure that restricts the left and right movement of the vehicle body side mast member 72 is provided at the front-rear intermediate part, thereby ensuring rigidity against loads in the direction that is likely to be applied to the front-rear intermediate part. With such a plurality of mast mechanisms 7, on the left or right side of the vehicle body 2, the vehicle body 2 can be firmly supported so as to be vertically movable with respect to the traveling structure 3.

[0366] (Item D6) The work vehicle 1 according to item D1 or D2, wherein on each of the left and right sides of the vehicle body 2, 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-rear direction.

[0367] With the above configuration, on both the left and right sides of the vehicle body 2, in the front-rear direction that is the longitudinal direction of the work vehicle 1, a plurality of mast mechanisms 7 including the first mast mechanism 7A and the second mast mechanism 7B are arranged side by side. Therefore, the portions on both the left and right sides of the vehicle body 2 in the work vehicle 1 can be made into a structure with high durability against the above-described loads.

[0368] (Item D7) The work vehicle 1 according to 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 part, the rear part, and the front-rear intermediate part between the front part and the rear part on each of the left and right sides of the vehicle body 2.

[0369] With the above configuration, on both the left and right sides of the vehicle body 2, a plurality of mast mechanisms 7 (front mast mechanism 7F, middle mast mechanism 7M, rear mast mechanism 7R) provided at the front part, rear part, and the middle part between the front and rear can firmly support the vehicle body 2 so as to be vertically movable with respect to the traveling structure 3.

[0370] (Item D8) The work vehicle 1 according to item D7, wherein the first mast mechanism 7A is provided at each of the front part and the rear part, and the second mast mechanism 7B is provided at the middle part between the front and rear.

[0371] With the above configuration, on both the left and right sides of the vehicle body 2, by providing the first mast mechanism 7A at the front part and the rear part, rigidity against loads in the directions that are likely to be applied to the front part and the rear part is ensured, and by providing the second mast mechanism 7B at the middle part between the front and rear, rigidity against loads in the directions that are likely to be applied to the middle part between the front and rear is ensured. With such a plurality of mast mechanisms 7 (front mast mechanism 7F, middle mast mechanism 7M, rear mast mechanism 7R), on both the left and right sides of the vehicle body 2, the vehicle body 2 can be firmly supported so as to be vertically movable with respect to the traveling structure 3.

[0372] (Item D9) The work vehicle 1 according to item D6, wherein among 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 front-rear direction of the work vehicle 1 are unified by either the first mast mechanism 7A or the second mast mechanism 7B.

[0373] With the above configuration, distortion and the like caused by different directions of ensuring rigidity against loads between the left side and the right side of the vehicle body 2 are eliminated, and the durability of various parts in the left-right direction of the work vehicle 1 can be enhanced.

[0374] (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 the side surface of the vehicle body 2, and the first member 71 is attached to the inner surface of the traveling structure 3.

[0375] With the above configuration, as the vehicle body 2 rises, the vehicle body side mast member 72 and the restricting portion 74 move upward with respect to the traveling side mast member 71, so there is a possibility that they may be exposed above the traveling structure 3. On the other hand, the traveling side mast member 71 remains fixed to the inner surface of the traveling structure 3 regardless of the upward movement of the vehicle body side mast member 72, so it is not exposed to the outside. While ensuring the protection of the mast mechanism 7 itself, a wide space that will not be invaded by the mast mechanism 7 when the vehicle body 2 rises can be secured above the traveling structure 3. By using this space for the arrangement of equipment, the freedom of the equipment layout in the entire work vehicle 1 can be enhanced.

[0376] As described above, the embodiments of the present invention have been explained. However, it should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of reference numerals

[0377] 1 Work vehicle 2 Vehicle body 3 Traveling structure 3L Left traveling structure 3R Right traveling structure 7 Mast mechanism 30 Traveling frame 30L Left traveling frame 30R Right traveling frame 30u Upper frame portion 30b Lower frame portion 31 Wheels 31F Front wheels 31R Rear wheels

Claims

1. A vehicle body movable in the vertical direction, a first device mounted on the vehicle body, a second device mounted on the vehicle body, left and right traveling structures provided on the left and right sides of the vehicle body, a moving mechanism for moving the vehicle body in the vertical direction, comprising: the vehicle body has a space portion formed at least between the first device and the second device, the moving mechanism positions the space portion between at least the first device and the second device and between the left and right traveling structures in the state where the vehicle body is in the lowest position, and positions the space portion above at least the first device and the second device and above the left and right traveling structures in the state where the vehicle body is in the highest position. A work vehicle.

2. The work vehicle according to claim 1, wherein the vehicle body has the space portion behind the first device mounted on the front portion of the vehicle body.

3. The work vehicle according to claim 2, wherein the vehicle body has the space portion between the first device and a second device mounted on the rear portion of the vehicle body.

4. the vehicle body is configured to be able to change the position of the first device back and forth, The work vehicle according to any one of claims 1 to 3, wherein the vehicle body can be switched between a state having the space portion and a state not having the space portion by the position change of the first device.

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