Work vehicle

Abstract

The invention provides a work vehicle which can easily improve operability. A work vehicle (10) is provided with: a machine body to which a work machine can be attached; a restriction operation unit (59); and a restriction state presentation unit (34). The restriction operation unit (59) receives an operation for restricting a lifting operation of the work machine. A restriction state presentation unit (34) presents in accordance with the state of the restriction operation unit (59).

Description

TECHNICAL FIELD

[0001] The present application relates to a work vehicle provided with a body to which a work machine is attachable. BACKGROUND

[0002] As a related art, a work vehicle such as a tractor capable of mounting a work machine at the rear of a body is known (for example, refer to Patent Literature 1). The work vehicle is provided with a lift hydraulic system for causing the work machine to perform a lift operation.

[0003] According to the lift hydraulic system, the lift lever is operated to mechanically drive the lift valve and cause the lift cylinder to extend and retract, whereby the work machine is caused to lift (so-called hydraulic automatic device). Further, the hydraulic adjustment knob is turned to operate the return valve, whereby the work speed of the lift cylinder is adjusted, and the return valve is completely closed to be able to cut off the hydraulic pressure.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2020-141687 SUMMARY

[0007] With regard to the structure of the above related art, although it is possible to restrict (prohibit) the lift operation of the work machine by closing the return valve, the hydraulic adjustment knob for operating the return valve is disposed under the feet of the operator seated on the driver's seat. Therefore, it is difficult for the operator to confirm the operation state of the return valve, and it is difficult to grasp whether the lift operation of the work machine is restricted. As a result, the operability of the work vehicle is sometimes felt to be low by the operator.

[0008] An object of the present application is to provide a work vehicle in which improvement in operability is easily achieved.

[0009] The work vehicle according to one aspect of the present application is provided with a body to which a work machine is attachable, a restriction operation portion, and a restriction state prompting portion. The restriction operation portion receives an operation for restricting a lift operation of the work machine. The restriction state prompting portion performs prompting corresponding to the state of the restriction operation portion.

[0010] EFFECT OF THE INVENTION

[0011] According to the present application, it is possible to provide a work vehicle in which improvement in operability is easily achieved. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a schematic perspective view of the work vehicle according to Embodiment 1 as viewed from the left front.

[0013] Figure 2This is a schematic perspective view of the work vehicle involved in Embodiment 1, viewed from the left rear.

[0014] Figure 3 This is a top view of the work vehicle involved in Embodiment 1.

[0015] Figure 4 This is a schematic left view of the work vehicle involved in Embodiment 1.

[0016] Figure 5 This is a summary right view of the work vehicle involved in Embodiment 1.

[0017] Figure 6 This is a summary front view of the work vehicle involved in Implementation Method 1.

[0018] Figure 7 This is a summary rear view of the work vehicle involved in Embodiment 1.

[0019] Figure 8 This is a block diagram showing the general structure of the work vehicle involved in Embodiment 1.

[0020] Figure 9 This is a top view showing the interior of the cab of the work vehicle according to Embodiment 1.

[0021] Figure 10 This is a schematic perspective view showing the interior of the cab of the work vehicle according to Embodiment 1.

[0022] Figure 11 This is a right-side outline view of the driver's section of the work vehicle according to Embodiment 1, omitting the driver's cab.

[0023] Figure 12 This is a schematic perspective view showing the interior of the cab of the work vehicle according to Embodiment 1.

[0024] Figure 13 This is a schematic diagram showing a display example of the display device of the work vehicle according to Embodiment 1.

[0025] Figure 14 This is a schematic perspective view showing the hydraulic cylinder of the work vehicle according to Embodiment 1.

[0026] Figure 15 This is a top view showing the structure of the work vehicle associated with the braking mechanism according to Embodiment 1.

[0027] Figure 16 This is a top view showing the structure of the work vehicle associated with the braking mechanism according to Embodiment 1.

[0028] Figure 17This is a schematic perspective view showing the structure of the work vehicle associated with the braking mechanism according to Embodiment 1.

[0029] Figure 18 This is a schematic left view showing the structure of the work vehicle associated with the braking mechanism according to Embodiment 1.

[0030] Figure 19 This is a schematic perspective view showing the structure of the work vehicle associated with the hydraulic pump according to Embodiment 1.

[0031] Figure 20 This is a schematic right view showing the structure of the work vehicle associated with the hydraulic pump according to Embodiment 1.

[0032] Figure 21 This is a schematic right view showing the structure of the work vehicle associated with the hydraulic pump according to Embodiment 1.

[0033] Figure 22 This is a schematic right view showing the structure of the work vehicle associated with the hydraulic pump according to Embodiment 1.

[0034] Figure 23 This is a schematic cross-sectional view showing the structure of the work vehicle associated with the hydraulic pump according to Embodiment 1.

[0035] Figure 24 This is a schematic perspective view showing the structure of the work vehicle associated with the hydraulic pump according to Embodiment 1.

[0036] Figure 25 This is a schematic perspective view showing the structure of the work vehicle associated with the hydraulic pump according to Embodiment 1.

[0037] Figure 26 This is a schematic perspective view showing the area around the engine hood of the work vehicle involved in Embodiment 1.

[0038] Figure 27 This is a schematic perspective view showing the interior of the engine hood of the work vehicle according to Embodiment 1.

[0039] Figure 28 This is a schematic perspective view showing the structure of the work vehicle associated with the cooling device according to Embodiment 1.

[0040] Figure 29 This is a schematic left view showing the structure of the work vehicle associated with the cooling device according to Embodiment 1.

[0041] Figure 30 This is a schematic exploded perspective view showing the structure of the work vehicle associated with the cooling device according to Embodiment 1.

[0042] Figure 31 This is a schematic perspective view showing the structure of the work vehicle associated with the cooling device according to Embodiment 1.

[0043] Figure 32 This is a schematic front view showing the structure of the work vehicle associated with the cooling device according to Embodiment 1.

[0044] Explanation of reference numerals in the attached figures

[0045] 10…Work vehicle; 11…Body; 12…Work machine; 19…Display device; 34…Restriction status indication unit; 51…Driver's seat; 59…Restriction operation unit. Detailed Implementation

[0046] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. These embodiments are merely examples embodying the present invention and are not intended to limit the scope of the invention.

[0047] (Implementation Method 1)

[0048] [1] Overall structure

[0049] First, refer to Figures 1-9 The overall structure of the work vehicle 10 involved in this embodiment will be described.

[0050] The work vehicle 10 has a body 11. The body 11 is configured to be able to assemble the work machine 12 (see reference). Figure 1 ). Figure 1 The outline of the work machine 12 is shown in the middle by a virtual line (double dotted line).

[0051] In this embodiment, for ease of explanation, the vertical direction in which the work vehicle 10 can be used is defined as the up-down direction D1 (refer to...). Figure 1 The forward / backward direction D2 and the left / right direction D3 are defined based on the direction observed from the operator (driver) sitting in the body 11 (driver's unit 5) of the work vehicle 10. The left side of the left / right direction D3 refers to the left side when the body 11 is moving forward (forward), and the right side of the left / right direction D3 refers to the right side when the body 11 is moving forward (forward). However, the above directions do not limit the direction of use of the work vehicle 10 (the direction during use).

[0052] Work vehicle 10 is in target area F1 (refer to) Figure 1The work vehicle 10 travels and performs a certain operation within the target area F1 using the work machine 12. In this disclosure, "operation" refers to the work performed by the work machine 12 on the target area F1, including various agricultural operations such as tilling, leveling, sowing, fertilizing, pesticide application, planting (transplanting), or harvesting, as well as various construction operations. In this embodiment, as an example, the operation performed by the work vehicle 10 is set as tilling.

[0053] When the body 11 of the work vehicle 10 moves within the target area F1, the work machine 12 performs work within the target area F1. In this embodiment, as an example, the work machine 12 is a tiller such as a rotary tiller or a plow that performs tillage operations.

[0054] This type of work machine 12 includes a direct-mounted work machine directly mounted to a three-point linkage, and a towed work machine pulled by a body 11. In this embodiment, as an example, the work machine 12 is a direct-mounted rotary tiller that is detachably mounted to the body 11 of the work vehicle 10. Here, the work machine 12 is mounted at the rear of the body 11 (opposite to the forward direction of the body 11). That is, the (direct-mounted) work machine 12 is connected to the rear of the body 11, and moves forward with the body 11 and performs work when the body 11 moves forward. In this embodiment, the work machine 12 is included in the structural elements of the work vehicle 10, but the work machine 12 can also be detached from the body 11; therefore, the work machine 12 may not be included in the structural elements of the work vehicle 10.

[0055] The term "operating vehicle" as used in this disclosure refers to, for example, a vehicle that performs various operations in a target area F1 such as a field, such as an agricultural machine (farm machinery) including tractors, seeders, rice transplanters, spreaders, sprayers, transplanters, and harvesters. The operating vehicle 10 may also be, for example, construction machinery (construction machinery). In this embodiment, unless otherwise specified, the case of a tractor equipped with a rotary tiller as the operating machine 12 will be described as an example. That is, the operating vehicle 10 is constructed by connecting the (direct-mounted) rotary tiller as the operating machine 12 and the tractor as the body 11. With this operating vehicle 10, the body 11 travels in the target area F1 such as a field to perform tillage operations in the target area F1.

[0056] Thus, in this embodiment, the body 11 is a type of vehicle that moves while traveling in the target area F1. Here, the body 11 has a front wheel 111 as a pair of left and right steering control wheels and a rear wheel 112 as a pair of left and right drive wheels, and travels in the target area F1 using the above four wheels (a pair of front wheels 111 and a pair of rear wheels 112).

[0057] The "target area" as used in this disclosure refers to the area where the work vehicle 10 moves while performing various operations such as tilling, leveling, sowing, fertilizing, applying pesticides, planting (transplanting rice), or harvesting, including paddy fields, dry fields, orchards, and pastures. For example, when the target area F1 is a paddy field or dry field where crops (crops) such as rice, wheat, soybeans, or buckwheat are grown, the crops grown in the target area F1 are crops. Furthermore, when seedlings are grown in a nursery, the nursery is the target area F1, and when trees are grown in a forest to become timber, as in forestry, the forest is the target area F1. In this case, the crops grown in the target area F1 are seedlings or trees, etc. In this embodiment, unless otherwise specified, the case where the work vehicle 10 is used for tilling operations in a field (target area F1), and the target area F1 is a paddy field for growing rice, will be described as an example. In addition, the target area F1 is not limited to fields. For example, if the working vehicle 10 is construction machinery, then the site where the construction machinery is working is the target area F1.

[0058] Furthermore, the work vehicle 10 can travel not only within the target area F1 (in this case, farmland), but also on roads outside the target area F1, such as paths outside the farmland. Paths outside the farmland are, for example, connecting roads between multiple target areas F1 (farmland). These connecting roads can be farmland roads, forest roads, public roads, private roads, or motor vehicle lanes, and can be roads dedicated solely to the work vehicle 10, or roads accessible to general vehicles (passenger cars, etc.).

[0059] Regarding the work vehicle 10 involved in this embodiment, the body 11 has a driver's seat 51 (see...). Figure 9 The driver's seat 51 is where the operator (driver) sits. Therefore, the work vehicle 10 is driven and performs work in the target area F1 by the operator sitting in the driver's seat 51 (manual driving).

[0060] However, the work vehicle 10 is not limited to a structure that is driven manually by an operator sitting in the driver's seat 51 (manual driving). For example, it can also perform actions through automatic driving (autonomous driving, etc.). Furthermore, the work vehicle 10 can be an automatically driving drone, or it can perform actions through remote operation by an operator.

[0061] The term "automatic driving" as used in this disclosure includes "autonomous driving," in which the work vehicle 10 drives itself without relying on operator input, and "semi-automatic driving," such as straight-line assist, which automates only steering. "Autonomous driving" is, for example, a driving mode where, as the work vehicle 10 travels along a target path, speed and other parameters are automatically controlled in addition to automatic steering of the front wheels 111. "Straight-line assist" is, for example, a driving mode where, as the work vehicle 10 travels along a straight path parallel to a reference line (baseline), only automatic steering of the front wheels 111 is performed, while speed and other parameters are controlled by the operator.

[0062] In other words, regarding "semi-automatic driving," although the work vehicle 10 cannot move without operator intervention, it reduces the burden of steering for the operator and allows it to travel along target paths such as straight lines, thus improving work efficiency. Furthermore, regardless of whether it's autonomous or semi-automatic driving, the front wheels 111 are automatically steered; therefore, it can be called an "automatic steering control mode." In automatic steering control mode, the front wheels 111 are automatically steered by an automatic steering control mechanism including a steering motor. That is, it replaces the operator's manual steering of the steering gear 52 (see reference 52). Figure 9 The method of operation involves changing the orientation of the front wheels 111 by using the output of the steering motor to achieve automatic steering control.

[0063] Based on the machine body 11, which includes a driver's section 5, a power source 6, and four wheels (front wheel 111 and rear wheel 112), such as Figure 8 As shown, the work vehicle 10 also includes a driving device 13, a steering control device 14, a braking mechanism 15, a hydraulic pump 16, a lifting device 17, a cooling device 18, and a display device 19. The work vehicle 10 also includes a control device 2, a first notification unit 31, a second notification unit 32, a notification unit 33, and a restriction status notification unit 34.

[0064] Based on the driver's seat 51, the driver's unit 5 is also equipped with a steering gear 52 and a control lever 54 (see reference). Figure 9 ) and pedal 55 (see Figure 9 The steering gear 52, control lever 54, and pedals 55 are operating components operated by the operator sitting in the driver's seat 5. The work vehicle 10 is configured to be manually driven by the operator manually operating the aforementioned operating components.

[0065] As for the types of driver's units 5 of the work vehicle 10, there are cab-type, canopy-type, and rope-type, etc. The cab-type driver's unit 5 includes a cab 50, and the driver's seat 51 is disposed in the interior space of the cab 50. The canopy-type driver's unit 5 includes a canopy (roof), and the driver's seat 51 is disposed in the space below the canopy. The rope-type driver's unit 5 does not have a cab 50 or a canopy, and the driver's seat 51 is disposed in an upward-open space. In this embodiment, the case where the driver's unit 5 is a cab-type with a cab 50 will be described as an example.

[0066] The cab 50 has a door that can be opened and closed on at least one side in the left-right direction D3. The operator can enter and exit from this door relative to the driver's compartment 5. The cab 50 has glass panels on its front, rear (back), left, and right sides.

[0067] A machine connection part 113 consisting of a three-point linkage mechanism and the like is provided at the rear of the machine body 11 (see reference). Figure 2 The work machine 12 can be mounted on the work machine connection part 113. The power generated by the power source 6 can be transmitted to the traction work machine 12 via a transmission device and a drive shaft (PTO shaft) located at the rear of the machine body 11. Here, the work machine 12 is detachably connected to the work machine connection part 113, so that devices other than the work machine 12 can also be connected to the machine body 11.

[0068] In this embodiment, the tiller 12 is a direct-mount rotary tiller, thus enabling tillage operations on the field, which is the target area F1, as the machine body 11 moves forward. The relative position (relative height) of the tiller 12 relative to the machine body 11 in the vertical direction D1 is variable. As a result, the height of the tiller 12, with the field surface, which is the target area F1, as a reference, is variable. For example, the tiller 12 can be raised to a height separate from the surface of the target area F1, thereby enabling the work vehicle 10 to travel in a non-working state without performing operations based on the tiller 12.

[0069] The lifting device 17 is a device for lifting the work machine 12. The lifting action of the work machine 12 is the action of changing the relative position (relative height) of the work machine 12 relative to the body 11 in the vertical direction D1. That is, the lifting device 17 causes the work machine 12 to rise or fall (ascend or descend) between the lower limit position and the upper limit position, so that the work machine 12 can be moved to any height relative to the ground surface of the target area F1.

[0070] The traveling device 13 is a device that drives the work vehicle 10 by driving the rear wheels 112, which are a pair of drive wheels. The traveling device 13 includes a transmission device, which transmits the power generated by the power source 6 to the rear wheels 112 to make the machine body 11 move forward or backward. In this embodiment, the rear wheels 112 are ordinary wheels, but are not limited to this. For example, the machine body 11 may be a half-track type with tracks (crawlers) for the rear wheels 112.

[0071] The steering control device 14 is a device for steering the front wheels 111, which are a pair of steering wheels. The steering control device 14 includes a steering gear 52, which steers the front wheels 111 according to the operator's operation of the steering gear 52. Figure 3 As shown, when viewed from above, the pair of front wheels 111 are in a position facing forward and backward in the direction D2, that is, in a position where the rotation axis is along the left and right direction D3, as the reference position. The steering control device 14 is used to perform steering control by tilting to the left or right from the reference position. That is, the steering control device 14 changes the orientation of the pair of front wheels 111 to perform steering control of the front wheels 111.

[0072] If the steering gear 52 is operated clockwise from the state where the pair of front wheels 111 are in a reference position, the steering control device 14 performs steering operation by tilting the pair of front wheels 111 (the front ends) to the right, causing the machine body 11 to turn right while moving forward. On the other hand, if the steering gear 52 is operated counterclockwise from the state where the pair of front wheels 111 are in a reference position, the steering control device 14 performs steering operation by tilting the pair of front wheels 111 (the front ends) to the left, causing the machine body 11 to turn left while moving forward. In this embodiment, the operator operates the steering gear 52 during manual steering operation, but it is not limited to this. For example, the operator can also perform manual steering operation by operating the control lever or the like.

[0073] Using this driving device 13 and steering control device 14, the machine body 11 can move within the target area F1 in a manner that moves along the forward-backward direction D2 and the left-right direction D3. For example, when the machine body 11 is moving forward by driving the rear wheels 112 using the driving device 13, if the angle of the front wheels 111 is changed using the steering control device 14, the machine body 11 turns in the left-right direction D3, thereby changing the direction of travel of the machine body 11.

[0074] The braking mechanism 15 decelerates or stops the machine body 11. The braking mechanism 15 applies braking to a pair of brake wheels (rear wheels 112) using two systems: the operation of the brake pedal and automatic control. That is, the braking mechanism 15 decelerates or stops the moving machine body 11 by braking the rear wheels 112, which are a pair of brake wheels.

[0075] As an example of automatic control of the braking mechanism 15, there is an "automatic braking" mechanism where, when the steering angle of the steering gear 52 reaches a predetermined angle or higher, the braking mechanism 15 applies brakes to the rear wheel 112 on the inside of the turn. Based on this automatic braking, the work vehicle 10 can reduce its turning radius, making it easier to perform small-angle turns, such as U-turns (for example, a change in direction at the head of the target area F1).

[0076] Power source 6 is a drive source that supplies power to at least the traveling device 13. Power source 6 is located at the front of the body 11 and is covered by an engine hood 114. Power source 6 is the drive source of the work vehicle 10, and for example, it is a diesel engine. However, the power source 6 of the work vehicle 10 is not limited to a diesel engine, and can also be an engine such as a gasoline engine, an electric motor, or a hybrid system of an engine and an electric motor.

[0077] Power source 6 drives hydraulic pump 16. That is, power from power source 6 is transmitted to drive hydraulic pump 16 via a power transmission mechanism. Hydraulic pump 16 supplies working oil to various hydraulic devices (hydraulic cylinders and hydraulic clutches, etc.) to enable the hydraulic devices to perform actions.

[0078] The pilot's unit 5 is located behind the power source 6 of the machine body 11. The pilot's unit 5 includes a pilot's seat 51 and an instrument panel 53 (see reference). Figure 9 The instrument panel 53 also serves as the steering column and is located in front of the driver's seat 51.

[0079] As an example, the steering gear 52 is a steering wheel operated by the operator seated in the driver's seat 51. The steering gear 52 is supported by a steering shaft located within the instrument panel 53 and is rotatable. The steering gear 52 is located in front of the driver's seat 51 and above the instrument panel 53. The steering control device 14 can change the orientation (steering angle) of the front wheels 111 by rotating the steering gear 52.

[0080] In addition, the driver's compartment 5 is equipped with, for example, a control lever 54 and pedals 55 operated by the operator, as well as an instrument displaying the speed of the work vehicle 10. The control lever 54 may include various levers, such as a main gear lever, a secondary gear lever, or a work lever. Furthermore, the pedals 55 may include various pedals, such as an accelerator pedal and a brake pedal.

[0081] In addition, such as Figure 4 and Figure 5 As shown, the work vehicle 10 is equipped with a gearbox 115. The gearbox 115 has a power transmission mechanism for transmitting power from the power source 6. The gearbox 115 includes at least a clutch housing and is located below the driver's cab 50 of the driver's unit 5.

[0082] The cooling device 18 is a device for cooling at least the power source 6, etc. Similar to the power source 6, the cooling device 18 is located at the front of the fuselage 11 and is covered by the engine hood 114. The cooling device 18 includes a radiator 61 (see reference). Figure 27 ).

[0083] Display device 19 is a user interface, such as a liquid crystal display or organic EL display, disposed in the driver's unit 5 and displaying various information, for providing prompts to the operator. Display device 19 provides various prompts to the operator by displaying them. In this embodiment, as an example, display device 19 is a backlit full-color liquid crystal display with a horizontally elongated display area.

[0084] Furthermore, the display device 19 can accept various operations performed by the operator, for example, by outputting electrical signals corresponding to the user's (operator's) operations. As a result, the user can visually confirm the display screen shown on the display device 19, and can also operate the display device 19 as needed.

[0085] The control device 2 controls each part of the work vehicle 10. The control device 2 is configured to communicate with the equipment installed in each part of the body 11. Here, the control device 2 can directly send and receive various information (data) with each device, or indirectly with the help of repeaters, etc.

[0086] The control device 2 is primarily structured as a computer system with one or more processors such as a CPU (Central Processing Unit) and one or more memories such as ROM (Read-Only Memory) and RAM (Random Access Memory), and performs various processes (information processing). In this embodiment, the control device 2 is a comprehensive controller that controls the entire work vehicle 10, and may be composed of, for example, an electronic control unit (ECU). However, the control device 2 may also be separate from the comprehensive controller.

[0087] like Figure 8 As shown, the control device 2 includes an acquisition processing unit 21, a differential locking control unit 22, and a restriction control unit 23. In this embodiment, as an example, the control device 2 is based on a computer system with one or more processors. Therefore, one or more processors execute control programs to implement the aforementioned multiple functional units (acquisition processing unit 21, etc.). The multiple functional units included in the control device 2 can be distributed in multiple housings or disposed in a single housing.

[0088] The acquisition and processing unit 21 performs the following acquisition process: acquiring information related to the status of each part of the work vehicle 10 (including information related to the operating status of the operating device and information related to the monitoring results of sensors used to monitor the operating status of the machine body 11).

[0089] Differential lock control unit 22 performs the following differential lock process: for the rear differential lock device 131 described later (refer to...) Figure 7 ) and front differential lock device 132 (see reference) Figure 6 (To be controlled)

[0090] The restriction control unit 23 performs lifting restriction processing to restrict the operation of the lifting device 17.

[0091] The first notification unit 31, the second notification unit 32, the notification unit 33, and the restriction status notification unit 34 each provide a notification (or report). The methods of "notification (or reporting)" as used herein include, for example, displaying on the display device 19, other displays (including turning on / off indicator lights), sound output (including voice), vibration, or sending information to other terminals. The first notification unit 31, the second notification unit 32, the notification unit 33, and the restriction status notification unit 34 will be described in detail below.

[0092] In addition to the above structure, the work vehicle 10 also includes a battery, a fuel tank, and various sensors. The battery supplies power for operation to various parts of the work vehicle 10, such as the control device 2.

[0093] [2] Structure associated with differential lock function

[0094] Next, refer to Figures 9-11 The structure associated with the differential lock function in the work vehicle 10 according to this embodiment will be described in detail.

[0095] First, regarding at least one pair of rear wheels 112, the work vehicle 10 according to this embodiment is equipped with a differential device (differential gear) for realizing a "differential" application of rotational difference between the left and right wheels. Specifically, in addition to the hydraulic continuously variable transmission, forward / reverse switching mechanism, and travel gear mechanism, a rear wheel differential gear (differential gear) mechanism is also provided in the gearbox 115. Power (rotational power) from the power source 6 is transmitted to the input shaft of the gearbox 115, where it is appropriately changed by the hydraulic continuously variable transmission and the travel gear mechanism, and the changed power is transmitted to the pair of rear wheels 112 by means of the rear wheel differential gear mechanism.

[0096] Here, a rear differential locking device 131 is provided in the rear wheel differential gear mechanism. This rear differential locking device 131 is used to limit (prohibit) the differential movement of a pair of rear wheels 112, so that the pair of rear wheels 112 rotate at the same speed. The rear differential locking device 131 mechanically connects the left and right axles connected to the pair of rear wheels 112 to eliminate rotational difference and thus limit differential movement. For example, the rear differential locking device 131 has a differential locking body that engages with the differential gearbox, thereby fixing the differential gearbox to the differential output shaft on the left and right sides, stopping the differential function of the rear wheel differential gear mechanism. When the rear differential locking device 131 is activated, the rear wheel differential gear mechanism is put into a "differential locking state," and the pair of rear wheels 112 rotate at the same speed without rotational difference.

[0097] For example, in specific situations such as driving on muddy roads or when a tractor is operating, the rear differential lock device 131 restricts the differential movement of the pair of rear wheels 112. That is, when the differential mechanism causes one of the pair of rear wheels 112 to slip and become unable to move or maintain straight-line stability, the rear differential lock device 131 operates to restrict the differential movement of the pair of rear wheels 112, thereby improving traction. However, if the differential movement of the pair of rear wheels 112 is restricted outside of the required conditions, steering performance decreases, which may hinder the movement of the work vehicle 10.

[0098] Therefore, the operation of the rear differential lock device 131 (the "active" state of the rear differential lock device 131) and the non-operational state of the rear differential lock device 131 (the "inactive" state of the rear differential lock device 131) can be switched according to the operator's operation.

[0099] However, regarding the work vehicle 10 involved in this embodiment, such as Figure 9 and Figure 10 As shown, a rear differential lock operation unit 56 for switching the activation / deactivation of the rear differential lock device 131 is located in front of the driver's seat 51 within the cab 50. That is, the work vehicle 10 includes: a body 11 having a pair of rear wheels 112; a driver's seat 51; a rear differential lock device 131; and a rear differential lock operation unit 56. The rear differential lock device 131 restricts the differential movement of the pair of rear wheels 112. The rear differential lock operation unit 56 handles operations to activate the rear differential lock device 131. Here, the rear differential lock operation unit 56 is located in front of the driver's seat 51.

[0100] According to this structure, from the perspective of the operator seated in the driver's seat 51, the rear differential lock operating unit 56 is located in a position that is easily within their field of vision and easy to operate. Therefore, for example, compared to the situation where the differential lock pedal for switching the activation / deactivation of the rear differential lock device 131 is under the operator's feet, the operator can more easily visually confirm the rear differential lock operating unit 56. As a result, it has the advantage of easily improving the operability of the work vehicle 10.

[0101] Furthermore, similar to the rear wheels 112, the pair of front wheels 111 are equipped with a front wheel differential gear mechanism in this embodiment, serving as a differential device (differential gear) for applying a rotational difference between the left and right wheels. The work vehicle 10 also includes a front differential locking device 132 and a front differential locking operation unit 57. The front differential locking device 132 restricts the differential movement of the pair of front wheels 111 of the body 11. The front differential locking operation unit 57 handles operations to activate the front differential locking device 132.

[0102] Therefore, similarly to the pair of rear wheels 112, the front differential locking device 132 operates under certain conditions to limit the differential movement of the pair of front wheels 111, thereby improving traction.

[0103] Here, as Figure 10 As shown, the front differential lock operation unit 57, used for switching the front differential lock device 132 active / inactive, is arranged adjacent to the rear differential lock operation unit 56. That is, the rear differential lock operation unit 56 and the front differential lock operation unit 57 are arranged in front of the driver's seat 51. In this embodiment, as an example, the rear differential lock operation unit 56 and the front differential lock operation unit 57 are arranged in the vertical direction D1 with the rear differential lock operation unit 56 located below it.

[0104] Therefore, from the perspective of the operator seated in the driver's seat 51, the front differential lock operating unit 57 is located in a position that is easily within their field of vision and easy to operate. Thus, for example, compared to a situation where the differential lock pedal for switching the front differential lock device 132 active / inactive is located under the operator's feet, the operator can more easily visually confirm the front differential lock operating unit 57. As a result, it has the advantage of easily improving the operability of the work vehicle 10.

[0105] More specifically, both the rear differential lock operation unit 56 and the front differential lock operation unit 57 are instantaneous push-button switches. When the rear differential lock device 131 is inactive (not in operation), if the rear differential lock operation unit 56 is pressed while the rear activation conditions are met, the differential lock control unit 22 of the control device 2 activates the rear differential lock device 131. Similarly, when the front differential lock device 132 is inactive (not in operation), if the front differential lock operation unit 57 is pressed while the front activation conditions are met, the differential lock control unit 22 activates the front differential lock device 132.

[0106] Conversely, when the rear differential lock device 131 is active (operating), if the rear differential lock operation unit 56 is pressed, the differential lock control unit 22 disables the rear differential lock device 131 (deactivates it). Similarly, when the front differential lock device 132 is active (operating), if the front differential lock operation unit 57 is pressed, the differential lock control unit 22 disables the front differential lock device 132 (deactivates it).

[0107] Here, the activation conditions (rear activation conditions and front activation conditions) for activating the differential locking devices (rear differential locking device 131 and front differential locking device 132) include various conditions. As an example, the activation conditions include at least one of the following: the steering angle of the steering gear 52 is below a specified angle, the vehicle speed is below a specified value, the auxiliary gear is in a low gear, and the brake on one side is disengaged.

[0108] The term "single-sided braking" here refers to the state where the brakes on the pair of rear wheels 112 function independently on the left and right sides. That is, as... Figure 10 As shown, the work vehicle 10 has a pair of brake pedals 581 and 582 arranged in the left-right direction D3 at the lower part in front of the driver's seat 51. The braking mechanism 15 brakes the left rear wheel 112 when the left brake pedal 581 is depressed, and brakes the right rear wheel 112 when the right brake pedal 582 is depressed. If one side of the brake is activated (effective), for example, when the machine body 11 turns, only the rear wheel 112 on the inside of the turn is braked, thereby further reducing the turning radius. On the other hand, when traveling at high speeds on roads or other places, in order to avoid sharp turns, for example, the pair of brake pedals 581 and 582 are connected by a brake coupling 583, so that the one side of the brake is disengaged (ineffective).

[0109] In summary, in this embodiment, the braking mechanism 15 includes a pair of braking devices that brake a pair of rear wheels 112 respectively. The rear differential lock operation unit 56 is operated under a (rear) activation condition to activate the rear differential lock device 131. The (rear) activation condition includes a braking linkage state where the pair of braking devices are linked. That is, at least the activation condition for activating the rear differential lock device 131 includes the brake coupling 583 connecting a pair of brake pedals 581, 582, resulting in a braking linkage state where the pair of braking devices are linked; in other words, unilateral brake disengagement (invalid).

[0110] Therefore, the rear differential locking device 131 can be activated to limit the differential movement of the pair of rear wheels 112 when only one side of the brake is disengaged, provided that a rotational difference is applied between the pair of rear wheels 112. Thus, it is possible to avoid a situation where only one side of the pair of rear wheels 112 is braked while limiting the differential movement of the pair of rear wheels 112.

[0111] Furthermore, in this embodiment, the rear differential lock device 131 is activated by operating the rear differential lock operation unit 56 when the rear activation condition is met, and the front differential lock device 132 is activated by operating the front differential lock operation unit 57 when the front activation condition is met. Here, the rear activation condition and the front activation condition can be set separately. That is, activation conditions for activating the differential lock devices can be set separately for the rear differential lock device 131 and the front differential lock device 132.

[0112] Therefore, as an example, the following settings can be made: the activation conditions for the rear differential lock device 131 (for rear use) include single-sided brake disengagement (invalidation), and the activation conditions for the front differential lock device 132 (for front use) do not include single-sided brake disengagement (invalidation). Therefore, the operability of the work vehicle 10 is further improved.

[0113] The work vehicle 10 according to this embodiment has an instrument panel 53 located in front of the driver's seat 51. A rear differential lock operation unit 56 (and a front differential lock operation unit 57) are disposed on the instrument panel 53. Other switches and instruments are disposed on the instrument panel 53.

[0114] According to this structure, from the perspective of the operator sitting in the driver's seat 51, the rear differential lock operation unit 56 (and the front differential lock operation unit 57) can be easily accessed by hand, and the operability of the rear differential lock operation unit 56 (and the front differential lock operation unit 57) is improved.

[0115] In this embodiment, a rear differential lock operation unit 56 and a front differential lock operation unit 57 are arranged on the right side of the center of the left-right direction D3 of the instrument panel 53, lower than the steering gear 52, and further forward than the steering gear 52.

[0116] More specifically, such as Figure 11 As shown, in a side view, the rear differential lock operating unit 56 (and the front differential lock operating unit 57) is positioned further forward than the front end of the steering gear 52. Furthermore, in a side view, the rear differential lock operating unit 56 (and the front differential lock operating unit 57) is positioned lower than the lower end of the steering gear 52.

[0117] Furthermore, the steering gear 52 can be configured to change the position (height) of the vertical direction D1 using a tilting mechanism and / or a telescopic mechanism. As an example, suppose the steering gear 52 moves to the lower end of its movable range, such that the steering gear 52 is positioned at... Figure 11 The position is indicated by the virtual line (double-dotted line). In this case, the rear differential lock operation unit 56 (and the front differential lock operation unit 57) is located at the same height as the steering gear 52. That is, the work vehicle 10 has a steering gear 52 located in front of the driver's seat 51, and when viewed from the side, the rear differential lock operation unit 56 (and the front differential lock operation unit 57) is positioned higher than the lower end of the steering gear 52.

[0118] According to this structure, such as Figure 10 As shown, the operator sitting in the driver's seat 51 can more easily visually confirm the rear differential lock operation unit 56 and the front differential lock operation unit 57 through the gaps in the steering wheel spokes of the steering gear 52.

[0119] In addition, such as Figure 10 As shown in the pop-up window, the work vehicle 10 according to this embodiment has a display mark M1 located at a position corresponding to the rear differential lock operation unit 56 and indicating the function of the rear differential lock operation unit 56. The display mark M1 is an image (icon) indicating the rear differential lock, marked on the operating surface (surface) of the push-button switch of the rear differential lock operation unit 56. The display mark M1 is marked on or near the rear differential lock operation unit 56 by means of printing, engraving, or sealing.

[0120] Therefore, it is easy for the operator to understand that by operating the rear differential lock operation unit 56, the rear differential lock device 131 is activated, and the operability of the work vehicle 10 is improved.

[0121] In this embodiment, the work vehicle 10 also includes a display mark M2 located at a position corresponding to the front differential lock operation unit 57 and indicating the function of the front differential lock operation unit 57. The display mark M2 is an image (icon) indicating the front differential lock, marked on the operating surface (surface) of the push-button switch of the front differential lock operation unit 57. The display mark M2 is marked on or near the front differential lock operation unit 57 by means of printing, engraving, or sealing.

[0122] However, at least under the condition of activation, the rear differential lock device 131 is switched between active and inactive whenever the rear differential lock operation unit 56 is operated. Therefore, the operator needs to operate the rear differential lock operation unit 56 based on knowing the current operating status (active / inactive) of the rear differential lock device 131.

[0123] Therefore, the first prompting unit 31 indicates the operating status of the rear differential lock device 131. The first prompting unit 31 is controlled by the differential lock control unit 22 of the control device 2, and the prompting content (prompt method) changes according to the operating status of the rear differential lock device 131. In this embodiment, as an example, the first prompting unit 31 includes a light-emitting part built into the push-button switch that serves as the rear differential lock operation unit 56, and indicates the operating status of the rear differential lock device 131 according to its light-emitting state (on, off, or flashing, etc.). For example, if the operator operates the rear differential lock operation unit 56 to make the rear differential lock device 131 active, the light-emitting part of the first prompting unit 31 will light up.

[0124] Therefore, the operator can use the first prompting unit 31 to understand the current operating status (active / inactive) of the rear differential lock device 131. In particular, as in this embodiment, the operating status of the rear differential lock device 131 is indicated by the illumination state of the push-button switch itself, which is the rear differential lock operation unit 56, so that the operator can easily understand the operating status of the rear differential lock device 131.

[0125] Furthermore, in this embodiment, as described above, the rear differential lock operation unit 56 is operated when the (rear) activation conditions are met, thereby activating the rear differential lock device 131. Therefore, the second prompt unit 32 indicates whether the (rear) activation conditions are met. The second prompt unit 32 is controlled by the differential lock control unit 22 of the control device 2, and the prompt content (prompt mode) changes according to whether the (rear) activation conditions are met. In this embodiment, as an example, the second prompt unit 32 includes a light-emitting unit built into the push-button switch that serves as the rear differential lock operation unit 56, and the prompt content (prompt mode) changes according to its light emission state (e.g., light emission color) and whether the (rear) activation conditions are met. For example, the light-emitting unit of the second prompt unit 32 emits green light when the (rear) activation conditions are met, and emits yellow light when the (rear) activation conditions are not met.

[0126] Therefore, the operator can use the second prompting unit 32 to determine whether the rear differential lock device 131 can be activated by operating the rear differential lock operation unit 56. In particular, as in this embodiment, the operator can easily determine whether the activation conditions are met by indicating the illumination state of the push-button switch itself, which serves as the rear differential lock operation unit 56. Furthermore, by preparing three or more illumination states (e.g., illumination color), a single illumination unit can also serve as both the first prompting unit 31 and the second prompting unit 32. For example, if the rear differential lock device 131 is inactive, the illumination unit illuminates yellow if the activation conditions are not met, green if the conditions are met, and red if the rear differential lock device 131 is active.

[0127] Furthermore, the rear differential lock operation unit 56 is operated when the (rear) activation conditions are met, thereby activating the rear differential lock device 131. Here, if the rear differential lock operation unit 56 is operated when the (rear) activation conditions are not met, the notification unit 33 issues a notification. The notification unit 33 is controlled by the differential lock control unit 22 of the control device 2, and issues a notification if the rear differential lock operation unit 56 is operated when the (rear) activation conditions are not met. In this embodiment, as an example, the notification unit 33 issues a notification via the display device 19. For example, if the rear differential lock operation unit 56 is operated when the (rear) activation conditions are not met, the notification unit 33 displays a message on the display device 19 indicating that the activation conditions are not met.

[0128] Therefore, the operator can understand that even though the rear differential lock operation unit 56 has been operated, the rear differential lock device 131 does not work, so the activation condition is not met, and therefore the rear differential lock device 131 does not work.

[0129] Furthermore, similar to the rear differential lock device 131, the front differential lock device 132 can be equipped with at least one of a first indicator 31, a second indicator 32, and a notification unit 33. For example, if the front differential lock device 132 is equipped with a first indicator 31, the first indicator 31 indicates the operating status of the front differential lock device 132. As an example, the first indicator 31 includes a light-emitting part built into the push-button switch that serves as the front differential lock operation unit 57, and indicates the operating status of the front differential lock device 132 according to its light-emitting state (on, off, or flashing, etc.).

[0130] [3] Structure associated with the lifting device

[0131] Next, refer to Figure 9 , Figures 12-14 The structure associated with the lifting device 17 in the work vehicle 10 according to this embodiment will be described in detail.

[0132] In this embodiment, the work machine 12, which is mounted on the work machine connection section 113 located at the rear of the machine body 11, can be lifted and lowered using the lifting device 17. The lifting device 17 includes a hydraulic cylinder 171 for lifting (see reference). Figure 14 The hydraulic cylinder 171 extends and retracts according to the operation of the lifting rod configured in the driver's unit 5, thereby raising and lowering the work machine 12.

[0133] Here, the lifting device 17 is not always operational, and its operation can be restricted (prohibited) by the restriction control unit 23 of the control device 2. Specifically, normally, the hydraulic cylinder 171 of the lifting device 17 is driven by the working oil (hydraulic pressure) supplied to it, thereby forming a "hydraulic unlocked state" that allows the lifting operation of the machine 12 based on the lifting device 17. On the other hand, the working oil (hydraulic pressure) supplied to the hydraulic cylinder 171 of the lifting device 17 is stopped, thereby forming a "hydraulic locked state" that restricts the lifting operation of the machine 12 based on the lifting device 17.

[0134] Furthermore, the system can switch between a "hydraulic unlocked state" that allows the lifting and lowering of the work machine 12 and a "hydraulic locked state" that restricts (prohibits) the lifting and lowering of the work machine 12, depending on the operator's operation. In the "hydraulic locked state," only the lifting and lowering of the work machine 12 based on the lifting device 17 is restricted, and the operation of the work machine 12 itself is not particularly restricted.

[0135] However, regarding the work vehicle 10 involved in this embodiment, such as Figure 12 (and Figure 9 As shown, the restriction operation unit 59 for switching the lifting and lowering movements of the work machine 12 is located diagonally rear right of the driver's seat 51 within the cab 50. Furthermore, the restriction status indication unit 34 provides indications corresponding to the status of the restriction operation unit 59. That is, the work vehicle 10 includes: a body 11 capable of mounting the work machine 12; a restriction operation unit 59; and a restriction status indication unit 34. The restriction operation unit 59 handles operations for restricting the lifting and lowering movements of the work machine 12. The restriction status indication unit 34 provides indications corresponding to the status of the restriction operation unit 59.

[0136] According to this structure, from the operator's perspective, the state of the restriction operation unit 59 can be understood through the prompts of the restriction status prompt unit 34. Therefore, for example, compared to a structure that restricts (prohibits) the lifting and lowering movement of the work machine 12 by turning a hydraulic adjustment knob located under the feet of the operator while seated in the driver's seat 51 to close the slow return valve, the operator can more easily confirm and understand the operating state of the restriction operation unit 59. As a result, it has the advantage of easily improving the operability of the work vehicle 10.

[0137] More specifically, the restriction operation unit 59 is composed of a momentary push-button switch. When the restriction control unit 23 of the control device 2 is in the "hydraulic unlocked state" that allows the lifting action of the machine 12 based on the lifting device 17, pressing the restriction operation unit 59 controls the restriction valve (solenoid valve) on the supply line that supplies working oil (hydraulic fluid) to the hydraulic cylinder 171, stopping the supply of working oil. Thus, a "hydraulic locked state" that restricts the lifting action of the machine 12 based on the lifting device 17 can be formed.

[0138] Conversely, when in a "hydraulic locked state" that restricts the lifting action of the work machine 12 based on the lifting device 17, if the restriction operation unit 59 is pressed, the restriction control unit 23 controls the restriction valve (solenoid valve) on the supply line that supplies working oil (hydraulic) to the hydraulic cylinder 171, restarting the supply of working oil. Thus, a "hydraulic unlocked state" that allows the lifting action of the work machine 12 based on the lifting device 17 can be formed.

[0139] Thus, in this embodiment, the switching between the "hydraulic unlocking state" and the "hydraulic locking state" is electrically controlled (electrified) using a limiting valve. In summary, the work vehicle 10 is equipped with a limiting valve that restricts the lifting and lowering movement of the work machine 12 based on an electrical signal corresponding to the operation of the limiting operation unit 59. Therefore, unlike the case where the slow-return valve is directly operated, the limiting operation unit 59 can be positioned separately from the limiting valve.

[0140] Here, the restriction status indicator 34 indicates the restriction status (hydraulic unlocking state / hydraulic locking state) of the lifting and lowering operation of the work machine 12. The restriction status indicator 34 is controlled by the restriction control unit 23 of the control device 2, and the indication content (indication method) changes depending on whether the hydraulic unlocking state or the hydraulic locking state is in effect. In this embodiment, as an example, the restriction status indicator 34 includes a light-emitting part built into the push-button switch that serves as the restriction operation unit 59, and the indication of whether the hydraulic unlocking state or the hydraulic locking state is in effect is determined by its illumination state (on, off, or flashing, etc.). For example, in the hydraulic locking state, the light-emitting part of the restriction status indicator 34 is on, and in the hydraulic unlocking state, the light-emitting part of the restriction status indicator 34 is off. However, this illumination state allocation is only one example; for example, it may also be configured such that the light-emitting part of the restriction status indicator 34 is on in the hydraulic unlocking state and off in the hydraulic locking state.

[0141] Thus, in this embodiment, the prompts from the restriction status prompt unit 34 include prompts corresponding to the restricted / unrestricted state of the lifting and lowering movement of the machine 12. Therefore, the operator can use the restriction status prompt unit 34 to understand the current restriction state of the lifting and lowering movement of the machine 12. In particular, as in this embodiment, the restriction state of the lifting and lowering movement of the machine 12 is indicated based on the illumination state of the push-button switch itself, which serves as the restriction operation unit 59; therefore, it is easy for the operator to understand the restriction state of the lifting and lowering movement of the machine 12.

[0142] Furthermore, in this embodiment, the restriction status prompting unit 34 provides a prompt at least when the lifting operation for the work machine 12 is performed. That is, the restriction status prompting unit 34 provides a prompt corresponding to the restricted / unrestricted state of the lifting operation of the work machine 12 at least at the time when the lifting lever for the lifting operation of the work machine 12 is operated. As a result, it is easy for the operator to grasp the restricted state of the lifting operation of the work machine 12.

[0143] Specifically, the restriction status indication unit 34 provides a warning at least when an operation for lifting the work machine 12 is performed while the lifting action of the work machine 12 is restricted. That is, in the hydraulically locked state, if the lifting lever for lifting the work machine 12 is operated, the restriction status indication unit 34 indicates that the lifting action of the work machine 12 is restricted in a "hydraulically locked state." Thus, the operator can understand that even if the lifting lever is operated, but the work machine 12 does not lift, it is in a "hydraulically locked state," and therefore, the work machine 12 does not lift. In this embodiment, the restriction status indication unit 34 is not limited to operations for lifting the work machine 12; it always provides a warning corresponding to the restricted / unrestricted state of the lifting action of the work machine 12.

[0144] Furthermore, the prompts from the restriction status indicator 34 include a prompt urging the release of the restriction on the lifting action. For example, when the lifting action of the work machine 12 is restricted, and an operation for lifting the work machine 12 is performed, the restriction status indicator 34 flashes, thereby urging the operator to operate the restriction operation unit 59 to release the restriction on the lifting action. Thus, even if the lifting rod has been operated, but the work machine 12 has not performed a lifting action, the operator can still be urged to operate the restriction operation unit 59 to achieve a "hydraulic unlocking state."

[0145] Furthermore, the work vehicle 10 according to this embodiment includes a driver's seat 51, and a restriction operation unit 59 is disposed to the side of the driver's seat 51. In this embodiment, as an example, the restriction operation unit 59 is disposed on the right side of the driver's seat 51. Therefore, the operator can operate the restriction operation unit 59 while seated in the driver's seat 51 by extending his hand to the restriction operation unit 59.

[0146] Furthermore, the restriction operation unit 59 is located rearward relative to the driver's seat 51. In this embodiment, as an example, the restriction operation unit 59 is positioned further rearward than the rear end of the driver's seat 51 (the back of the seat back). Therefore, the possibility of the operator accidentally operating the restriction operation unit 59 can be reduced.

[0147] In addition, such as Figure 13 As shown, the work vehicle 10 also displays information on the display device 19 corresponding to the state of the restriction operation unit 59. That is, the display device 19 displays information at least corresponding to the state of the restriction operation unit 59. Figure 13 An example of the following screen is shown: When the lifting action of the work machine 12 is restricted (hydraulic locked state), this screen is displayed on the display device 19 when the lifting rod used for the lifting action of the work machine 12 is operated. In this example, a message pops up on the display screen of the display device 19 urging the operator to perform the lifting operation of the work machine 12 again after operating the restriction operation unit 59 (hydraulic locking switch) (disconnecting it).

[0148] Therefore, the operator can also grasp the current lifting and lowering limit status of the machine 12 based on the display of the display device 19.

[0149] However, as Figure 14As shown, the hydraulic cylinder 171 of the lifting device 17 includes: a cylinder body 172; a cover 173 that closes one side of the cylinder body 172; and a rod 174 that passes through a hole 176 in the cover 173. The hydraulic cylinder 171 is driven by working oil to extend and retract the rod 174. A dustproof seal 177 is provided inside the hole 176 of the cover 173 to fill the gap between the cover and the rod 174.

[0150] Here, a groove 175 is formed on the surface (upper surface) of the cover portion 173. The groove 175 communicates with the hole 176 of the cover portion 173. Water (rainwater, etc.) accumulated in the hole 176 (on the dust seal 177) can be drained through this groove 175. As a result, rust on the outer peripheral surface of the rod portion 174 is easily prevented.

[0151] In this embodiment, when viewed from above, a plurality of grooves 175 extending from the hole 176 in at least two directions are provided. This allows for drainage in at least two directions, thereby reducing constraints on the installation direction of the cover 173 and improving assembly workability.

[0152] Furthermore, multiple slots 175 are arranged at equal intervals around the holes 176. In this embodiment, as an example, the cover 173 is circular when viewed from above, and two slots 175 are arranged at 180-degree intervals around the holes 176. This is not limited to this example; for instance, three slots 175 may be arranged at 120-degree intervals around the holes 176. This further reduces the constraints on the mounting direction of the cover 173.

[0153] Furthermore, the bottom surface of the groove 175 is parallel to the surface (upper surface) of the cover 173, or the groove 175 is inclined relative to the surface (upper surface) of the cover 173 such that the groove 175 becomes deeper towards the outer periphery of the cover 173. As a result, water can be prevented from flowing into the inner periphery (hole 176) of the cover 173 along the groove 175, or water can easily flow towards the outer periphery of the cover 173 due to the gradient formed in the groove 175, thereby improving the drainage effect.

[0154] Regarding the cover portion 173, the external thread formed on the outer peripheral surface is fastened relative to the internal thread formed on the inner peripheral surface of the cylinder body portion 172, thereby installing it onto the cylinder body portion 172. Therefore, the installation and removal of the cover portion 173 from the cylinder body portion 172 becomes easier, thus improving assembly operability and maintainability. Even with this structure, since the multiple slots 175 extend in at least two directions, the constraint on the installation direction of the cover portion 173 is also reduced.

[0155] [4] Structure associated with braking mechanism

[0156] Next, refer to Figures 15-18The structure associated with the braking mechanism 15 in the work vehicle 10 according to this embodiment will be described in detail.

[0157] The work vehicle 10 is equipped with a pair of braking mechanisms 15 corresponding to a pair of brake wheels (rear wheels 112). One of the braking mechanisms 15 brakes the left rear wheel 112, and the other braking mechanism 15 brakes the right rear wheel 112. Thus, the work vehicle 10 can achieve, for example, "automatic braking" such that when the steering angle of the steering gear 52 reaches a predetermined angle or higher, either braking mechanism 15 brakes the rear wheel 112 on the inside of the turn.

[0158] like Figure 15 As shown, the work vehicle 10 includes a brake drive unit 7, which drives a pair of brake mechanisms 15 during automatic braking and other operations. The brake drive unit 7 is disposed on the upper surface of the gearbox 115. The brake drive unit 7 is connected to the pair of brake mechanisms 15 via a pair of wires 70, and operates the pair of brake mechanisms 15 respectively using the pair of wires 70.

[0159] like Figure 16 As shown, the brake drive unit 7 includes a pair of brake cylinders 71, a pair of brake valves 72 (automatic brake valves), and a pair of linkage mechanisms 73. The pair of brake cylinders 71 are hydraulic cylinders that are operated by means of working oil supplied by the pair of brake valves 72. The pair of brake valves 72 are each composed of a controllable switching valve such as a solenoid valve, which controls the supply of working oil to the pair of brake cylinders 71 and causes the pair of brake cylinders 71 to operate respectively.

[0160] A pair of linkage mechanisms 73 connects the rods 711 (pistons) of a pair of brake cylinders 71 to a pair of wires 70. That is, if a pair of brake cylinders 71 is driven, a pair of brake mechanisms 15 are operated by means of a pair of linkage mechanisms 73 and a pair of wires 70.

[0161] One of a pair of brake cylinders 71 drives a braking mechanism 15 via a linkage mechanism 73 and a wire 70, and uses the braking mechanism 15 to brake the left brake wheel (rear wheel 112). The other brake cylinder 71 drives another braking mechanism 15 via another linkage mechanism 73 and a wire 70, and uses the braking mechanism 15 to brake the right brake wheel (rear wheel 112).

[0162] The brake drive unit 7 thus configured is fixed to the upper surface of the gearbox 115. In particular, in this embodiment, the gearbox 115 is configured by combining three housings divided in the longitudinal direction D2, and the brake drive unit 7 is disposed on the upper surface of the front housing of the three housings.

[0163] More specifically, such as Figure 17 As shown, the brake drive unit 7 also includes a housing 74, a fulcrum 75, and a mounting plate 76. A pair of brake cylinders 71 and a pair of brake valves 72 are integrated by means of the housing 74. The pair of brake cylinders 71 are arranged in a left-right direction D3. The pair of brake valves 72 are arranged in front of the pair of brake cylinders 71 and in a left-right direction D3.

[0164] Here, a pair of brake cylinders 71 are configured such that the direction of movement of their pistons is changed to the forward-backward direction D2. Each pair of brake cylinders 71 has a rod 711 protruding rearward from the rear end, and the rod 711 is connected to the wire 70 by means of a linkage mechanism 73. Specifically, the left brake cylinder 71 is connected to the right wire 70 by one linkage mechanism 73, and the right brake cylinder 71 is connected to the left wire 70 by another linkage mechanism 73.

[0165] Each of the two linkage mechanisms 73 is supported by a fulcrum 75 located at the rear of the housing 74, enabling it to rotate. The fulcrum 75 is a shaft component with a length in the vertical direction D1, and the two linkage mechanisms 73 can rotate around the fulcrum 75 when viewed from above. The fixing plate 76 is a metal plate with a length in the front-rear direction D2, which is mounted between the upper surface of the housing 74 and the upper end of the fulcrum 75 to fix the fulcrum 75.

[0166] According to the above structure, if the left brake valve 72 is used to cause the left brake cylinder 71 to operate by pushing the lever 711 backward, then a linkage mechanism 73 is used to stretch the right wire 70, thereby activating the right brake mechanism 15. Similarly, if the right brake valve 72 is used to cause the right brake cylinder 71 to operate by pushing the lever 711 backward, then another linkage mechanism 73 is used to stretch the left wire 70, thereby activating the left brake mechanism 15.

[0167] As explained above, the work vehicle 10 according to this embodiment includes: a body 11 having a pair of brake wheels (rear wheels 112); a pair of braking mechanisms 15; and a pair of brake cylinders 71. The braking mechanism 15 brakes the pair of brake wheels. The pair of brake cylinders 71 correspond to the pair of brake wheels and drive the braking mechanism 15. Here, the pair of brake cylinders 71 are arranged in a position that moves the piston along the longitudinal direction D2 of the body 11.

[0168] According to this structure, the pair of brake cylinders 71 are configured such that the piston's direction of movement changes longitudinally (towards the front-rear direction D2) relative to the body 11. Therefore, compared to a structure in which the pair of brake cylinders 71 are arranged laterally relative to the body 11, it is easier to make the length of the wires 70 connecting the pair of brake cylinders 71 to the left and right brake mechanisms 15 consistent in the left-right direction. As a result, the work vehicle 10 according to this embodiment has the advantage of easily obtaining the desired braking characteristics.

[0169] In addition, such as Figure 16 As shown, a pair of brake cylinders 71 are positioned at the center of the left-right direction D3 of the body 11 (the center of the left-right direction D3 of the gearbox 115). This makes it easier to make the lengths of the wires 70 connecting the pair of brake cylinders 71 to the left and right brake mechanisms 15 more consistent in the left-right direction. In addition, it also helps to improve the left-right weight balance.

[0170] Furthermore, on the left-right direction D3 of the machine body 11, the midpoint P1 of a pair of brake wheels (rear wheel 112) (refer to...) Figure 15 Located between a pair of brake cylinders 71 (refer to) Figure 16 In other words, in the left-right direction D3, the midpoint P1 of the pair of brake wheels (rear wheel 112) is located between the two ends of the pair of brake cylinders 71. As a result, it is easy to make the length of the wire 70 connecting the pair of brake cylinders 71 to the left and right brake mechanisms 15 more consistent in the left-right direction.

[0171] Furthermore, the pair of brake cylinders 71 have a symmetrical structure in the left-right direction D3 of the body 11. That is, the pair of brake cylinders 71 are configured to be left-right symmetrical. As a result, it is easy to make the length of the wires 70 connecting the pair of brake cylinders 71 to the left and right brake mechanisms 15 more consistent in the left-right direction.

[0172] Furthermore, the work vehicle 10 has a pair of wires 70 extending from a pair of brake cylinders 71 toward a pair of brake wheels (rear wheels 112). That is, the pair of wires 70 extend rearward from a pair of brake cylinders 71 (via a pair of linkage mechanisms 73) and are connected to a pair of brake mechanisms 15. As a result, it is easy to make the length of the wires 70 connecting the pair of brake cylinders 71 to the left and right brake mechanisms 15 consistent in the left and right direction.

[0173] Furthermore, the work vehicle 10 according to this embodiment includes a pair of linkage mechanisms 73 that correspond to and are driven by a pair of brake cylinders 71 respectively. The pair of linkage mechanisms 73 perform operations with the same fulcrum 75 as the fulcrum. Therefore, the pair of linkage mechanisms 73 can be compactly configured, and the number of components in the pair of linkage mechanisms 73 can be set to be the same, so it is difficult to have differences in the left and right directions due to the influence of swaying. In addition, the pair of linkage mechanisms 73 have degrees of freedom in the vertical direction D1, so it is difficult for the layout of the pair of linkage mechanisms 73 to be restricted by surrounding components.

[0174] Furthermore, the fulcrum portion 75 is a shaft member having a length in the vertical direction D1, and both ends in the length direction are supported. That is, the upper end of the fulcrum portion 75 is supported on the fixed plate 76, and the lower end of the fulcrum portion 75 is supported on the gearbox 115 (by means of a strut). Thus, the fulcrum portion 75 can be firmly supported, for example, preventing the fulcrum portion 75 from deflecting due to the pressing load from the pair of brake cylinders 71.

[0175] In addition, such as Figure 18 As shown, a pair of brake cylinders 71 are positioned above the gearbox 115, which has a power transmission mechanism. That is, the brake drive unit 7, including a pair of brake cylinders 71, is positioned on the upper surface of the gearbox 115. Therefore, it is easy to prevent the brake cylinders 71 from contacting the ground or foreign objects such as stones kicked up by the front wheels 111 when the work vehicle 10 is in motion.

[0176] Furthermore, a pair of brake cylinders 71 are disposed in the space between the transmission 115 and the passenger compartment (driver's compartment 5). That is, the brake drive unit 7, including the pair of brake cylinders 71, is disposed on the upper surface of the transmission 115 and below the floor (floor material) of the driver's compartment 5. Therefore, for example, the brake cylinders 71 can be operated from the side or by removing the floor of the driver's compartment 5 from the driver's compartment 5 side, thereby improving the maintainability of the brake cylinders 71.

[0177] [5] Structure associated with hydraulic pumps

[0178] Next, refer to Figures 19-25 The structure associated with the hydraulic pump 16 in the work vehicle 10 according to this embodiment will be described in detail.

[0179] The hydraulic pump 16 is driven by power transmitted from the power source 6 via a power transmission mechanism, and working oil is supplied to various hydraulic devices (hydraulic cylinders and hydraulic clutches, etc.) to cause them to perform actions. In this embodiment, as an example, such as... Figures 19-21 As shown, the hydraulic pump 16 is located below the driver's compartment 5 and is on one side (the right side) of the gearbox 115 of the machine body 11 in the left-right direction D3.

[0180] More specifically, a gearbox 83 is mounted on the right side of the gearbox 115. The gearbox 83 houses a power extraction mechanism for transmitting power from the power source 6 to the hydraulic pump 16 and driving the hydraulic pump 16. The power extraction mechanism within the gearbox 83 extracts power from the power transmission mechanism within the gearbox 115 and outputs this power to the hydraulic pump 16 to drive the hydraulic pump 16.

[0181] In addition, the hydraulic pump 16 has at least a first pump 81 and a second pump 82. The power extraction mechanism in the gearbox 83 transmits power extracted from the power transmission mechanism in the gearbox 115 to both the first pump 81 and the second pump 82.

[0182] That is, the work vehicle 10 according to this embodiment includes: a body 11, which has a power source 6; a hydraulic pump 16; and a gearbox 83. The hydraulic pump 16 is driven by the power source 6 to discharge working oil. The gearbox 83 houses the power extraction mechanism that transmits the power from the power source 6 to the hydraulic pump 16. Here, the hydraulic pump 16 has a first pump 81 and a second pump 82. The first pump 81 and the second pump 82 are arranged on both sides of the gearbox 83 with the gearbox 83 separated by a distance.

[0183] According to this structure, a hydraulic pump 16, including a first pump 81 and a second pump 82, can be arranged in the space on both sides of the gearbox 83, which is provided to extract power from the power source 6. Therefore, by arranging the first pump 81 and the second pump 82 near the gearbox 83, the distance between the hydraulic pump 16 and the gearbox 83 can be easily minimized, simplifying the structure for transmitting power from the gearbox 83 (gear mechanism). Consequently, power transmission losses are less likely to occur. As a result, the work vehicle 10 according to this embodiment has the advantage of easily simplifying the structure for transmitting power to the hydraulic pump 16.

[0184] Furthermore, the gearbox 83 is located on the side of the transmission 115 (right side in this embodiment). As a result, the power extraction mechanism inside the gearbox 83 can directly extract power from the power transmission mechanism inside the transmission 115.

[0185] Here, the first pump 81 has a variable capacity structure, and the second pump 82 has a fixed capacity structure. As an example, the first pump 81 is a variable capacity piston pump (axial piston pump or radial piston pump) capable of changing the discharge volume (flow rate) of the working oil; the piston reciprocates as the input shaft rotates, discharging the working oil. The second pump 82 is a fixed capacity gear pump (gear pump) with a constant discharge volume (flow rate) of the working oil; the gear rotates as the input shaft rotates, discharging the working oil. The first pump 81 supplies working oil to the working machine 12 and the lifting device 17, etc., while the second pump 82 supplies working oil to the traveling device 13, etc.

[0186] Thus, although different types of first pumps 81 and second pumps 82 can be driven by a single gearbox 83, the aforementioned different types of first pumps 81 and second pumps 82 can also be compactly mounted.

[0187] Here, the first pump 81, gearbox 83, and second pump 82 are arranged in the longitudinal direction D2 of the body 11. The gearbox 83 is mounted on the right side of the gearbox 115; therefore, the first pump 81, gearbox 83, and second pump 82 are arranged in a straight line along the longitudinal direction D2 on the right side of the gearbox 115. In this embodiment, as an example, the first pump 81, gearbox 83, and second pump 82 are arranged from the rear in the order of first pump 81, gearbox 83, and second pump 82.

[0188] Therefore, the lateral dimension D3 of the body 11 of the work vehicle 10 can be kept relatively small. That is, for example, compared to a structure in which the first pump 81 and / or the second pump 82 are arranged relative to the gearbox 83 in the lateral dimension D3 of the body 11, the amount of the hydraulic pump 16 extending laterally from the gearbox 115 can be kept relatively small. Therefore, for example, with respect to a work vehicle 10 with a narrow tire specification and a smaller width for the pair of rear wheels 112, it is also easy to configure the hydraulic pump 16 without interfering with the pair of rear wheels 112.

[0189] Furthermore, the rotational force about the same axis is transmitted from the gearbox 83 to the first pump 81 and the second pump 82. That is, as Figure 23 As shown, the gearbox 83 has an output shaft Ax10 that rotates about a rotation axis Ax1 along the front-rear direction D2 of the body 11, and the input shaft Ax20 of the first pump 81 and the second pump 82 are arranged on the same axis as the output shaft Ax10. Figure 23 This is a schematic sectional view of the first pump 81, the second pump 82, and the gearbox 83. Figure 23 The section lines of the cross section are omitted.

[0190] Therefore, the rotational force from the gearbox 83 can be directly input to the first pump 81 and the second pump 82, thereby easily simplifying the gear mechanism. Furthermore, since the first pump 81 and the second pump 82 are arranged on the same shaft (rotation shaft Ax1), it is easy to achieve weight balance and suppress the reduction of strength.

[0191] Here, the second pump 82 includes a drive gear pump 821 and a booster pump 822. Working oil discharged from the booster pump 822 is supplied to the first pump 81. The drive gear pump 821 and booster pump 822 included in the second pump 82 are mechanically connected. That is, the drive gear pump 821 and booster pump 822 are linked. Therefore, the power extraction mechanism in the gearbox 83 extracts power from the power transmission mechanism in the transmission 115 and transmits it to the second pump 82, thereby driving both the drive gear pump 821 and the booster pump 822.

[0192] Therefore, the working oil pressurized by the booster pump 822 is supplied to the first pump 81, thus making it easy to increase the pressure of the working oil discharged from the first pump 81.

[0193] Furthermore, regarding the first pump 81 and the second pump 82, the inlet and outlet of the working oil share the same orientation. In this embodiment, as an example, such as... Figure 22 As shown, the suction inlet 811 of the first pump 81, the suction inlet 823 of the gear pump 821 of the second pump 82, and the suction inlet 824 of the booster pump 822 all face downwards. On the other hand, as... Figure 22 As shown, the outlet 812 of the first pump 81, the outlet 825 of the gear pump 821 of the second pump 82, and the outlet 826 of the booster pump 822 all face upwards.

[0194] This ensures that the inlet and outlet of the working oil face the same direction, thereby enabling a compact configuration of the piping supplying the working oil to the first pump 81 and the second pump 82, as well as the piping through which the working oil discharged from the first pump 81 and the second pump 82 passes.

[0195] Here, as Figure 20 and Figure 21 As shown, the work vehicle 10 is equipped with a pipeline filter 841. The pipeline filter 841 is inserted into the supply line (pipeline 851) that supplies working oil from the booster pump 822 to the first pump 81. Furthermore, the work vehicle 10 is equipped with a suction filter 842 that is inserted into the supply line (pipeline 852) that supplies working oil to the second pump 82.

[0196] According to this structure, working oil is supplied from the container through a suction filter 842 and via piping 852 to the gear pump 821 for travel and the booster pump 822 of the second pump 82. The suction filter 842, with its coarse pores, removes impurities mixed in with the working oil when supplied to the second pump 82, ensuring a certain level of cleanliness. Based on this, the working oil discharged from the booster pump 822 is supplied to the first pump 81 through piping 851 and a line filter 841. The line filter 841, with its fine pores, provides working oil with higher cleanliness, thus enabling the supply of high-cleanliness working oil to hydraulic equipment requiring high cleanliness, such as piston pumps and solenoid valves.

[0197] Here, the suction filter 842 (in the vertical direction D1) is positioned lower than the second pump 82. Specifically, the suction filter 842 is positioned lower than the lower ends of the travel gear pump 821 and booster pump 822 of the second pump 82. Thus, although the suction filter 842 is located near the hydraulic pump 16, it can also be positioned to overlap with the hydraulic pump 16 when viewed from above, thereby achieving a compact configuration.

[0198] Furthermore, at least a portion of the piping 852 that forms the oil supply path between the booster pump 822 and the first pump 81 is flexible. In this embodiment, the piping 852 between the booster pump 822 and the line filter 841 is made of a hydraulic hose. Therefore, the layout of the oil supply path between the booster pump 822 and the first pump 81 is improved, enabling a compact configuration.

[0199] However, the line filter 841 (on the vertical direction D1) is positioned lower than the first pump 81. Specifically, the line filter 841 is positioned lower than the lower end of the first pump 81 and to the side (right side) of the suction filter 842 (see reference). Figure 19 According to this configuration, the piping from the line filter 841 to the first pump 81 can be compactly constructed.

[0200] On the other hand, for example, regarding work vehicles 10 with narrow tire tread specifications, it is preferable to, for example, in Figure 22 Pipeline filter 841 is configured at the location indicated by the virtual line (double-dotted line). Figure 22 In this example, the pipeline filter 841 is positioned in front of the second pump 82. Specifically, the pipeline filter 841 is positioned further forward than the front end of the travel gear pump 821 of the second pump 82. With this configuration of the pipeline filter 841, the lateral dimension D3 of the body 11 of the work vehicle 10 can be reduced to a smaller size.

[0201] In addition, such as Figure 24 As shown, the work vehicle 10 also includes a flow divider 86. The flow divider 86 is positioned above the first pump 81 and diverts the working oil discharged from the first pump 81. Specifically, the flow divider 86 is connected to the outlet 812 of the first pump 81, causing the working oil discharged from the first pump 81 to be distributed to multiple oil lines. This allows the working oil discharged from the first pump 81 to be distributed to multiple hydraulic devices. In particular, by diverting the working oil immediately after it is discharged from the first pump 81, the oil path from the first pump 81 to the flow divider 86 can be shortened, thus suppressing pressure loss.

[0202] exist Figure 24In this example, the diversion component 86 has a first branch port 861, a second branch port 862, and a third branch port 863, which diverts the working oil discharged from the first pump 81 into three oil lines. Here, as an example, the lifting device 17 is connected to the first branch port 861, the working machine 12 is connected to the second branch port 862, and a working machine, such as a front loader, mounted in front of the body 11 is connected to the third branch port 863.

[0203] And, as Figure 25 As shown, the work vehicle 10 also includes a connecting component 87. The connecting component 87 is positioned below the first pump 81 and connected to the suction port 811 of the first pump 81. That is, the connecting component 87 is inserted between the pipeline filter 841 and the first pump 81, drawing working oil discharged from the booster pump 822 into the suction port 811 of the first pump 81. The connecting component 87 has a pressure relief valve 871, which controls the pressure in the booster circuit.

[0204] In addition, such as Figure 20 As shown, the work vehicle 10 also includes a relay component 88. The relay component 88 is connected to the outlet 812 of the first pump 81 via piping (including a diversion component 86) and is configured to connect to the target device. In this embodiment, as an example, the third branch port 863 of the diversion component 86 is connected to the relay component 88. Here, the relay component 88 is positioned in front of the second pump 82. Specifically, the relay component 88 is positioned further forward than the front end of the travel gear pump 821 of the second pump 82.

[0205] By providing this relay component 88, the hydraulic equipment (object equipment) supplied with working oil from the first pump 81 can be freely replaced. The relay component 88 is positioned further forward than the rear wheel 112 in a side view (see reference). Figure 20 Therefore, the relay component 88 can be operated even without removing the rear wheel 112, thereby improving workability.

[0206] [6] Structures associated with cooling devices

[0207] Next, refer to Figures 26-32 The structure associated with the cooling device 18 in the work vehicle 10 according to this embodiment will be described in detail.

[0208] like Figure 26 and Figure 27 As shown, the work vehicle 10 has an engine hood 114 at the front of the body 11, and a cooling device 18 and a power source 6 are provided in the area covered by the engine hood 114. The work vehicle 10 also has a side panel 116 disposed below the engine hood 114, which at least covers the sides of the cooling device 18 and the power source 6.

[0209] The engine hood 114 can be opened and closed, and the side panel 116 can be removed. Therefore, the cooling device 18 and the power source 6, which are located in the area covered by the engine hood 114 and the side panel 116, can be operated and maintained. Figures 27-32 The illustrations of the engine hood 114 and side panel 116 are omitted.

[0210] like Figure 27 As shown, the cooling device 18 has a radiator 61 arranged in an upright position in front of the power source 6. The radiator 61 is formed as a rectangle with a length in the vertical direction D1 when viewed from the front, and is arranged in a position such that its thickness is consistent in the front-rear direction D2.

[0211] The cooling device 18 includes a cooling fan 62 in addition to the radiator 61. The cooling fan 62 is positioned between the radiator 61 and the power source 6, and is arranged with its axis facing forward and backward in the direction D2. The cooling fan 62 is connected to the power source 6, rotates as driven by the power source 6, and generates airflow (cooling wind) from the front (radiator 61 side) of the body 11 to the rear (power source 6 side).

[0212] Therefore, airflow is drawn in from the front of the body 11 (opposite to the cooling fan 62) relative to the radiator 61. That is, the airflow passing through the radiator 61 from front to rear becomes cooling air and cools the radiator 61. By cooling the radiator 61, the radiator 61 cools the refrigerant (cooling water) passing through the power source 6.

[0213] like Figures 27-30 As shown, the cooling device 18 also includes an intercooler 63, an oil cooler 64, a condenser 65, and a fuel cooler 66. The intercooler 63 cools the air supplied to the power source 6. The oil cooler 64 cools the working oil. The condenser 65 is a condenser for the air conditioning system installed in the driver's compartment 5, and cools the refrigerant of the air conditioning system. The fuel cooler 66 cools the fuel of the power source 6.

[0214] Intercooler 63 and oil cooler 64 are positioned in front of radiator 61 (upstream of airflow). Intercooler 63 is located above oil cooler 64 (see reference). Figure 29 The condenser 65 is positioned in front of the oil cooler 64 (upstream of the airflow). The fuel cooler 66 is positioned in front of the condenser 65 (upstream of the airflow).

[0215] As a result, the airflow (cooling air) generated when the cooling fan 62 is driven is split into two parts in the vertical direction D1. Moreover, the upper airflow passes through the intercooler 63 and the upper part of the radiator 61 in sequence, while the lower airflow passes through the fuel cooler 66, the condenser 65, the oil cooler 64 and the lower part of the radiator 61 in sequence.

[0216] In addition, the cooling device 18 also has a radiator grille 9. The radiator grille 9 is a mesh-like component, which is arranged in front of the radiator 61 (upstream of the airflow) to filter out debris and dust that are transported to the radiator 61 along with the airflow (cooling air) and prevent debris and dust from adhering to the radiator 61.

[0217] Among them, such as Figure 29 and Figure 30 As shown, the radiator grille 9 has a first grille 91 and a second grille 92. That is, the radiator grille 9 is not a single unit, but is composed of multiple grilles (two in this embodiment) (first grille 91 and second grille 92).

[0218] The first grille 91 and the second grille 92 are arranged in a vertical direction D1 when viewed from the front. The first grille 91 is positioned above the second grille 92, and in the front view, the lower end of the first grille 91 coincides with the upper end of the second grille 92. Thus, the radiator grille 9 covers approximately the entire front surface of the radiator 61 using both the first grille 91 and the second grille 92.

[0219] The first grille 91, in the front view, is formed as a rectangle with a length in the left-right direction D3, and is arranged in an upright position where its thickness is consistent in the front-back direction D2. The second grille 92, in the front view, is also formed as a rectangle with a length in the left-right direction D3, and is arranged in an upright position where its thickness is consistent in the front-back direction D2. In this embodiment, the dimensions of the first grille 91 and the second grille 92 in the long side direction (left-right direction D3) are the same, while the dimension of the first grille 91 in the short side direction (up-down direction D1) is smaller.

[0220] The first grille 91 is positioned in front of the intercooler 63 (upstream of the airflow). The first grille 91 contacts the front surface of the intercooler 63 and is directly mounted on the intercooler 63. Thus, the first grille 91 is positioned in front of the upper part of the radiator 61, across the intercooler 63.

[0221] The second grille 92 is disposed between the oil cooler 64 and the radiator 61. The second grille 92 contacts the lower front surface of the radiator 61 and is directly mounted on the radiator 61. Thus, the second grille 92 is disposed at the lower front of the radiator 61.

[0222] According to the above configuration, in the longitudinal direction D2 of the fuselage 11, the first grille 91 is positioned in front of the second grille 92. That is, the first grille 91 and the intercooler 63 are respectively positioned further forward (upstream of the airflow) than the second grille 92.

[0223] The first grille 91 and the second grille 92, configured in this way, are detachably mounted on the body 11. Therefore, during maintenance, the first grille 91 and the second grille 92 can be replaced separately.

[0224] As explained above, the work vehicle 10 according to this embodiment includes: a body 11 having a radiator 61; a radiator grille 9; and a heat exchanger (intercooler 63, etc.). The radiator grille 9 is disposed upstream (front) of the airflow drawn into the radiator 61. The heat exchanger is disposed upstream (front) of the airflow relative to the radiator 61. Viewed from the upstream side of the airflow, the radiator grille 9 has a divided first grille 91 and a second grille 92. Here, the first grille 91 is disposed upstream (front) of the airflow at least relative to the heat exchanger.

[0225] The term "heat exchanger" as used here refers to various heat exchangers that have the function of receiving airflow (cooling air) and exchanging heat, such as at least one including an intercooler, an oil cooler, a condenser, and a fuel cooler. In this embodiment, the intercooler 63 is an example of a "heat exchanger". That is, the first grille 91 is disposed at least upstream (front) of the airflow relative to the intercooler 63, which is a heat exchanger.

[0226] According to this structure, a portion of the radiator grille 9 (the first grille 91) functions not only relative to the radiator 61 but also as a grille to prevent debris and dust from adhering to the heat exchanger (intercooler 63). That is, the first grille 91 serves both as the radiator 61 and the heat exchanger (intercooler 63), thus reducing the number of components compared to a separate grille for the heat exchanger (intercooler 63). As a result, it offers the advantage of more efficient utilization of the radiator grille 9.

[0227] In this embodiment, the heat exchanger (intercooler 63) is positioned upstream (in front) of the radiator 61. This allows the airflow passing through the heat exchanger (intercooler 63) to be drawn into the radiator 61, thereby suppressing a decrease in the cooling efficiency of the heat exchanger.

[0228] Furthermore, the first grille 91 is positioned above the second grille 92. That is, the radiator grille 9 is divided into two parts in the vertical direction D1. Therefore, for example, it is possible to remove only one side of the first grille 91 and the second grille 92 from the side in the horizontal direction D3 of the body 11, thereby improving maintainability.

[0229] Furthermore, the first grille 91 and the second grille 92 are offset in the longitudinal direction D2 of the body 11. In this embodiment, as described above, the first grille 91 is offset further forward (upstream of the airflow) than the second grille 92 relative to the heat exchanger (intercooler 63). Therefore, when only one of the first grille 91 and the second grille 92 is removed, it is difficult for them to interfere with each other, thereby improving maintainability.

[0230] Furthermore, viewed from the upstream (front) side of the airflow, a portion of the first grille 91 and the second grille 92 overlap. Specifically, the lower end of the first grille 91 coincides with (overlaps with) the upper end of the second grille 92. Thus, viewed from the upstream (front) side of the airflow, the first grille 91 and the second grille 92 can cover the entire area of ​​the radiator 61 without gaps.

[0231] In addition, such as Figure 28 As shown, wall portions 93 are arranged on both sides of the body 11 in the width direction (left-right direction D3) relative to the space between the radiator 61 and the heat exchanger (intercooler 63). That is, a pair of wall portions 93 block both sides of the space between the radiator 61 and the heat exchanger (intercooler 63) in the left-right direction D3. In this embodiment, a slit 94 for assembling and disassembling the second grille 92 is formed on at least one side (left side) of the wall portion 93. Figures 29-32 The illustration of the left wall portion 93 is omitted.

[0232] According to this structure, even if there is a space between the first grille 91 and the radiator 61, airflow can be prevented from entering the space from the side. As a result, airflow passing through the first grille 91 can be easily drawn into the radiator 61, while airflow that does not pass through the first grille 91 can be prevented from being drawn into the radiator 61.

[0233] However, in this embodiment, such as Figure 31 and Figure 32 As shown, the first grille 91 and the second grille 92 are assembled in a manner that allows them to be removed from one side (the left side in this case) in the left-right direction D3 of the body 11. Therefore, when the engine hood 114 is open, the first grille 91 and the second grille 92 can be removed and installed, thereby improving maintainability.

[0234] Specifically, the two ends of the first grille 91 in the vertical direction D1 are supported by a first upper support portion 951 and a first lower support portion 952. Specifically, the first upper support portion 951 has a groove shape that extends in the horizontal direction D3 and opens downwards, while the first lower support portion 952 has a groove shape that extends in the horizontal direction D3 and opens upwards. The first upper support portion 951 is only provided at the center of the intercooler 63 in the horizontal direction D3, and the first lower support portion 952 is provided along the entire length of the intercooler 63 in the horizontal direction D3. Furthermore, the left end of the first grille 91 is securely connected to the first locking portion 953.

[0235] Therefore, if the first locking part 953 is in the locked state, the first grille 91 is positioned in all directions: vertical direction D1, front-back direction D2, and left-right direction D3. On the other hand, if the first locking part 953 is in the unlocked state, the first grille 91 can be guided by the first upper support part 951 and the first lower support part 952 and slide along the left-right direction D3 while being positioned in the vertical direction D1 and the front-back direction D2.

[0236] In summary, the first grille 91 is installed on the body 11 in a manner that allows it to be detached through an operation including sliding movement. As a result, maintainability is improved by pulling the first grille 91 to the side (left side in this embodiment) to remove it.

[0237] On the other hand, the two ends of the second grille 92 in the vertical direction D1 are supported by the second upper support portion 961 (see reference). Figure 32 The second upper support portion 961 and the second lower support portion 962 provide support. Specifically, the second upper support portion 961 has a groove shape that extends downward in the left-right direction D3, and the second lower support portion 962 has a groove shape that extends upward in the left-right direction D3. The second upper support portion 961 is only provided at the right end of the radiator 61 in the left-right direction D3, and the second lower support portion 962 is provided along the entire length of the radiator 61 in the left-right direction D3. Furthermore, the left end of the second grille 92 is fastened to the second locking portion 963.

[0238] Therefore, if the second locking part 963 is in the locked state, the second grille 92 is positioned in all directions: vertical direction D1, front-back direction D2, and left-right direction D3. On the other hand, if the second locking part 963 is in the unlocked state, the second grille 92 can be guided by the second upper support part 961 and the second lower support part 962 and slide along the left-right direction D3 while being positioned in the vertical direction D1 and the front-back direction D2.

[0239] Here, regarding the second grille 92, unlike the first grille 91, the second upper support portion 961 supporting its upper end is only provided on the opposite side (right side) of the extraction side (left side) in the left-right direction D3. Therefore, as Figure 32 As shown by the dashed line (double dotted line), the second grille 92 can rotate its left end upwards while being pulled slightly to the left, and in this state, it can be pulled out diagonally upwards to the left.

[0240] In summary, the second grille 92 is installed on the body 11 in a manner that allows it to be detached through an operation including rotational movement. Thus, the second grille 92 can be detached even in more confined spaces, even if it cannot be pulled out to the side (left side in this embodiment) as it is, thereby improving maintainability.

[0241] [7] Variations

[0242] Hereinafter, variations of Embodiment 1 are given. The variations described below can be appropriately combined and applied.

[0243] The driver's cab 5 of the work vehicle 10 is not limited to the cab specification; for example, it can also be a canopy specification or a rope specification.

[0244] Furthermore, the heat exchanger located on the downstream side of the airflow relative to the first grille 91 is not limited to the intercooler 63, and may include at least one of the following: an intercooler, an oil cooler, a condenser, and a fuel cooler. For example, multiple heat exchangers such as the intercooler 63 and the oil cooler 64 may be arranged on the downstream side of the airflow relative to the first grille 91.

[0245] [Postscript to the Invention]

[0246] The following is a summary of the invention derived from the above embodiments. Furthermore, the structures and processing functions described in the following notes can be selected and combined arbitrarily.

[0247] <Postscript 1>

[0248] A type of work vehicle, wherein,

[0249] The operating vehicle is equipped with:

[0250] The machine body, which can be equipped with the work machine;

[0251] The limiting operation unit accepts operations for limiting the lifting and lowering movements of the work machine; and

[0252] The restriction status prompting unit provides prompts corresponding to the status of the restriction operation unit.

[0253] <Appendix 2>

[0254] According to the operating vehicles listed in Appendix 1, among them,

[0255] The prompts in the restriction status prompt section include prompts corresponding to the restricted / unrestricted status of the lifting action of the machine.

[0256] <Appendix 3>

[0257] According to the operating vehicles listed in Appendix 1 or 2, among which,

[0258] The restriction status prompt unit provides a prompt at least when the lifting action for the work machine is performed.

[0259] <Appendix 4>

[0260] According to the operating vehicles listed in Appendix 3, among them,

[0261] The restriction status prompt unit provides a prompt at least when the lifting action of the work machine is performed under a restricted lifting action.

[0262] <Appendix 5>

[0263] According to Appendix 4, the operating vehicles include,

[0264] The prompts from the restriction status prompt include prompts urging the lifting of the restriction on the lifting action.

[0265] <Appendix 6>

[0266] According to any of the items listed in Appendix 1 to 5, the operating vehicles, among which,

[0267] The work vehicle is also equipped with a limiting valve, which limits the lifting and lowering action of the work machine according to an electrical signal corresponding to the operation of the limiting operation unit.

[0268] <Appendix 7>

[0269] According to any of the items listed in Appendix 1 to 6, the operating vehicles, among which,

[0270] The work vehicle is also equipped with a driver's seat.

[0271] The restriction operating unit is located to the side of the driver's seat.

[0272] <Appendix 8>

[0273] According to the operating vehicles listed in Appendix 7, among them,

[0274] The restriction operating unit is located rearward relative to the driver's seat.

[0275] <Appendix 9>

[0276] According to any of the items listed in Appendix 1 to 8, the operating vehicles, among which,

[0277] The work vehicle is also equipped with a display device that displays at least the status of the restricted operation unit.

Claims

1. A work vehicle, wherein the work vehicle is provided with: a machine body to which a work machine is mountable; a restriction operation section that accepts an operation for restricting a lifting action of the work machine; and a restriction state prompting section that performs a prompt corresponding to a state of the restriction operation section.

2. The work vehicle according to claim 1, wherein the prompt of the restriction state prompting section includes a prompt corresponding to a state of restriction / non-restriction of the lifting action of the work machine.

3. The work vehicle according to claim 1 or 2, wherein the restriction state prompting section performs the prompt at least when an operation for the lifting action of the work machine is performed.

4. The work vehicle according to claim 3, wherein the restriction state prompting section performs the prompt at least when an operation for the lifting action of the work machine is performed in a state where the lifting action of the work machine is restricted.

5. The work vehicle according to claim 4, wherein the prompt of the restriction state prompting section includes a prompt that urges a release of the restriction of the lifting action.

6. The work vehicle according to claim 1 or 2, wherein the work vehicle is further provided with a restriction valve that restricts the lifting action of the work machine in accordance with an electric signal corresponding to an operation of the restriction operation section.

7. The work vehicle according to claim 1 or 2, wherein the work vehicle is further provided with a driver's seat, the restriction operation section is disposed laterally to the driver's seat.

8. The work vehicle according to claim 7, wherein the restriction operation section is located relatively rearward with respect to the driver's seat.

9. The work vehicle according to claim 1 or 2, wherein the work vehicle is further provided with a display device that performs at least a display corresponding to a state of the restriction operation section.

10. The work vehicle according to claim 7, wherein the work vehicle is further provided with a display device that performs at least a display corresponding to a state of the restriction operation section, the display device is disposed laterally to the driver's seat in the same direction as the restriction operation section.

11. The work vehicle according to claim 10, wherein the restriction operation section is located relatively rearward with respect to the driver's seat, and the display device is disposed more forward of the machine body than the restriction operation section.

Images