Work vehicles and coupling devices

Abstract

Regarding the work vehicle, the connection structure between the attached work implement and the part that outputs power to that implement will be simplified. [Solution] The work vehicle 10 includes a vehicle body 11, a travel device 12 for moving the vehicle body 11, and a coupling device 15 for connecting a work machine 19 to the vehicle body 11. The coupling device 15 includes a mounting unit 18 for attaching the work machine 19 to the vehicle body 11 so that it can be raised and lowered, and a motor 74 that outputs power to the work machine 19. The motor 74 is attached to the mounting unit 18, and the mounting unit 18 raises and lowers the motor 74 together with the work machine 19.

Description

Technical Field

[0005] , , , , ,

[0006] ,

[0001] The present invention relates to a work vehicle used for performing operations such as agricultural work, and a connecting device for connecting a working machine to the work vehicle.

Background Art

[0002] Patent Document 1 discloses a work vehicle having a three-point link at the rear. The three-point link connects a working machine for performing agricultural work such as tilling to the work vehicle. The three-point link has a function of raising and lowering the working machine according to the work.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] A coupling device for connecting a work machine to a work vehicle comprises a mounting unit that attaches the work machine to the work vehicle so that it can be raised and lowered, and a motor that outputs power to the work machine. The motor is attached to the mounting unit, and the mounting unit raises and lowers the motor together with the work machine. [Effects of the Invention]

[0008] According to the present invention, it is possible to simplify the connection structure between a work machine and a part (motor) that outputs power to the work machine. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view showing one form of implementation using a work vehicle. [Figure 2] Figure 2 is a perspective view of the work vehicle. [Figure 3] Figure 3 is a plan view of the work vehicle shown in Figure 2. [Figure 4] Figure 4 is a left side view of the work vehicle shown in Figure 2. [Figure 5] Figure 5 is a right side view of the work vehicle shown in Figure 2. [Figure 6] Figure 6 is a diagram showing the configuration of the work vehicle. [Figure 7] Figure 7 is a schematic diagram showing a deformed work vehicle. [Figure 8] Figure 8 is a schematic diagram showing a deformed work vehicle. [Figure 9] Figure 9 is a schematic diagram showing a deformed work vehicle. [Figure 10]Figure 10 is a schematic view showing a modified work vehicle. [Figure 11] Figure 11 is a perspective view showing the rear part of the vehicle body and the connecting device shown in FIG. 2. [Figure 12] Figure 12 is a perspective view showing a state where the connecting device is removed from the vehicle body. [Figure 13] Figure 13 is a perspective view of the connecting device as viewed from the work vehicle side. [Figure 14] Figure 14 is a perspective view of the connecting device as viewed from the work implement side (rear side). [Figure 15] Figure 15 is an explanatory view of the rear part of the work vehicle. [Figure 16] Figure 16 is an explanatory view showing the case where the cover is in the first state. [Figure 17] Figure 17 is an explanatory view showing a modified example of the cover. [Figure 18] Figure 18 is an explanatory view showing a modified example of the cover.

Embodiments for Carrying out the Invention

[0010] <Summary of the Embodiment> The summary of the embodiments of the invention will be listed and described below. (1) The work vehicle of this embodiment includes a vehicle body, a traveling device for driving the vehicle body, and a connecting device for connecting a work implement to the vehicle body. The connecting device includes an attachment unit that attaches the work implement to the vehicle body so as to be able to move up and down, and a motor that outputs power to the work implement. The motor is attached to the attachment unit, and the attachment unit raises and lowers the motor together with the work implement.

[0011] According to the work vehicle, a connecting device for connecting a working machine to the vehicle body has a motor, and the output of the motor is used as the power of the working machine. Therefore, the work vehicle and the working machine do not require a motor for working power. Moreover, the motor is attached to an attachment unit of the connecting device, and the attachment unit raises and lowers the motor together with the working machine. Therefore, the connection structure between the working machine and the motor is simplified.

[0012] (2) In the work vehicle of (1) above, the attachment unit is detachable from the vehicle body. The connecting device is detachable from the vehicle body.

[0013] (3) In the work vehicle of (1) or (2) above, the vehicle body has a central frame and a pair of side frames located on both sides of the central frame and displaceable relative to the central frame, The traveling device is attached to each of the pair of side frames, and has a displacement actuator that enables the side frame to be displaced relative to the central frame in at least one of the front-rear direction, left-right direction, and up-down direction. For example, the vehicle body is deformed according to the shape of the road surface on which it travels. The work vehicle can cause the working machine to perform work while traveling according to the shape of the road surface.

[0014] (4) In any one of the work vehicles of (1) to (3) above, the vehicle body has a central frame having a battery and a case for housing the battery, and a pair of side frames located on both sides of the central frame to which the traveling device is attached, The case is displaceable in the front-rear direction and is housed in the central frame. When the case is displaced in the front-rear direction, the work vehicle (vehicle body) is deformed.

[0015] (5) The coupling device of this embodiment is a coupling device for coupling a work machine to a work vehicle, and comprises a mounting unit for attaching the work machine to the work vehicle so that it can be raised and lowered, and a motor that outputs power to the work machine, wherein the motor is attached to the mounting unit, and the mounting unit raises and lowers the motor together with the work machine.

[0016] The coupling device for connecting the work equipment to the vehicle body has a motor, and the output of this motor is used to power the work equipment. Therefore, the work vehicle and work equipment do not need separate motors for power. Moreover, the motor is attached to a mounting unit on the coupling device, and the motor moves up and down together with the work equipment by this mounting unit. This simplifies the coupling structure between the work equipment and the motor.

[0017] (6) In the coupling device of (5) above, the mounting unit is detachable from the work vehicle. The coupling device can be attached to and detached from the work vehicle.

[0018] (7) In the coupling device of (5) or (6) above, the mounting unit has a first mounting portion to be attached to the work vehicle, a second mounting portion to which the work machine is attached, and a lifting mechanism to raise and lower the second mounting portion and the motor relative to the first mounting portion. The first mounting section can be attached to the work vehicle, making the installation of the mounting unit easy. The work implement can be attached to the second mounting section, making the installation of the work implement easy.

[0019] (8) In the coupling device of (7) above, the lifting mechanism comprises a link mechanism and an actuator, the link mechanism comprises an upper link member and a lower link member, the first end of which is attached to the first mounting portion and the second end of which is attached to the second mounting portion, and the actuator drives the lower link member or the upper link member to move up and down relative to the first mounting portion. The link mechanism allows for a more compact design of the lifting mechanism.

[0020] (9) Any one of the coupling devices described in (5) to (8) above has an inverter that outputs power to the motor. The motor's rotation is controlled by an inverter mounted on the coupling device. Furthermore, if the specifications of the motor, such as its output, need to be changed according to the work equipment, for example, if the inverter is mounted inside the work vehicle, this operation becomes relatively difficult. In contrast, by mounting the inverter on the coupling device, the operation of changing the specifications as described above becomes easier.

[0021] (10) The coupling device of (7) has an inverter that outputs power to the motor, and the lifting mechanism has a link mechanism and an actuator, the link mechanism has an upper link member and a lower link member, the first end of which is attached to the first mounting part and the second end of which is attached to the second mounting part, the actuator drives the lower link member or the upper link member up and down relative to the first mounting part, and a coupling that connects the electrical wiring connected to the motor and the electrical wiring connected to the inverter is attached to the upper link member. The link mechanism allows for a more compact design of the lifting mechanism. The fact that the aforementioned coupling is attached to the upper link member makes maintenance, such as replacing the inverter or motor, easier.

[0022] (11) In the coupling device of (8) or (10) above, the link mechanism comprises the upper link member and two lower link members located below the upper link member and on both sides of the upper link member in a plan view, and the motor is located below the upper link member and between the two lower link members. The motor is located below the upper link member, in the space formed between the two lower link members. This allows for efficient use of space and enables a compact coupling device configuration.

[0023] (12) In the coupling device of (9) or (10) above, when the direction of travel of the work vehicle is defined as the front in the front-rear direction, and the horizontal direction perpendicular to the front-rear direction is defined as the left-right direction, the motor is located in the center in the left-right direction, and the inverter is located on the left or right side in the left-right direction. This allows for a more compact design in the front-to-back direction of the coupling device.

[0024] (13) The coupling device described in (7), (8), or (10) has an inverter that outputs power to the motor, the inverter is attached to the first mounting part, and the motor is attached to the second mounting part. The motor is mounted on a second mounting point and moves up and down, while the inverter is mounted on a first mounting point fixed to the work vehicle and does not move up or down. This reduces the load on the lifting mechanism.

[0025] (14) The coupling device described in (7), (8), (10), or (13) is located on the side of the first mounting portion and has a coupling for connecting one or both of the liquid piping and electrical wiring. When attaching the coupling device to a work vehicle, the coupling facilitates the connection of necessary connections between the coupling device and the work vehicle, such as hydraulic piping, liquid piping for work equipment, electrical wiring for motors, or electrical wiring for work equipment.

[0026] (15) In the coupling device of (7), (8), (10), (13) or (14) above, the first mounting portion has a mounting frame that is long in the vertical direction and includes an upper fixing member and a lower fixing member that connect to a fixing portion of the work vehicle, and the mounting frame has an opening that penetrates in the front-rear direction from the work vehicle side to the work machine side. The mounting frame of the first mounting section is connected to the upper and lower mounting sections of the work vehicle by upper and lower fixing members, resulting in a strong connection. Even if the mounting frame is enlarged vertically, wiring or piping can be routed between the work vehicle and the coupling device through the opening.

[0027] (16) In the coupling device of (7), (8), (10), (13), (14) or (15) above, the second mounting portion has a hitch frame that facilitates the attachment and detachment of the work machine. The aforementioned hitch frame is, for example, the same as the hitch frame mounted on a conventional tractor. In this case, conventional implements can be attached, and the implements can be easily attached and detached.

[0028] <Details of the Embodiment of the Invention> The embodiments of the invention will be described in detail below with reference to the drawings. At least some of the embodiments described below may be combined in any way.

[0029] [Overall configuration of work vehicles] Figures 1 and 2 are perspective views showing one embodiment of a work vehicle. This work vehicle 10 has an exterior member 9, and Figure 2 shows the exterior member 9 removed. The exterior member 9 is attached to the frames 20 and 21 of the work vehicle 10. The exterior member 9 protects the various components of the work vehicle 10 and enhances its aesthetic appearance. Figures 3, 4, and 5 are a top view, left side view, and right side view of the work vehicle 10 shown in Figure 2. Figure 6 is a diagram showing the configuration of the work vehicle 10.

[0030] The work vehicle 10 has a running gear 12 and travels on road surfaces such as fields and roads. In the case of the work vehicle 10 of this embodiment, the direction pointed to by arrow X1 in each figure is the basic direction of travel and is defined as "forward". In each figure, the direction pointed to by arrow X2 is the opposite direction of the basic direction of travel and is defined as "rear". In each figure, the direction pointed to by arrow Y1 is defined as "left", the direction pointed to by arrow Y2 is defined as "right", the direction pointed to by arrow Z1 is defined as "up", and the direction pointed to by arrow Z2 is defined as "down".

[0031] The work vehicle 10 is capable of moving straight in both forward and backward directions, as well as turning left (left turn) and turning right (right turn), thanks to its running gear 12. The running gear 12 is located at four locations on the front, rear, left, and right sides of the vehicle body 11, and each running gear 12 has wheels 25. The work vehicle 10 has a hydraulic motor, which allows the direction of the wheels 25 (the direction in which the wheels 25 roll) to be changed within a 360-degree range. Therefore, the work vehicle 10, which can move forward and backward, can move in a straight line in all 360 degrees. Note that an electric motor may be used instead of the hydraulic motor. Alternatively, the work vehicle 10 may be able to change the direction of the wheels 25 within a range of 0 to 90 degrees from the basic direction of travel by, for example, a hydraulic cylinder. When the direction of the wheels 25 changes by 90 degrees from the basic direction of travel, its rolling direction becomes either left or right. The work vehicle 10 can also move straight in either the left or right direction. Furthermore, the work vehicle 10 may be able to change the direction of its wheels 25 within a range of 0 to -90 degrees using the hydraulic cylinder from its basic direction of travel. Since the direction of the wheels 25 can be changed within a range of 0 to 90 degrees and within a range of 0 to -90 degrees from its basic direction of travel, and since it is possible to move forward and backward, the work vehicle 10 can move in a straight line in all 360 degrees.

[0032] The work vehicle 10 connects to the work machine 19 via a coupling device 15. Figures 1, 2, 4, and 5 show the work machine 19 as a dashed line. The work machine 19 has a configuration and functions for performing various tasks. The tasks performed by the work machine 19 include, but are not limited to, agricultural work, industrial work (civil engineering, construction, etc.), and transportation work. The work vehicle 10 travels together with the work machine 19, while the work machine 19 performs its tasks.

[0033] In this embodiment, the work performed by the implement 19 is agricultural work. The implement 19 includes, for example, a spraying device for applying fertilizer or chemicals to a field, a seeding device for sowing seeds, a tilling device for cultivating the soil, a tilling device for tilling the soil, a weeding device for weeding, a soil mounding device for mounding soil, and so on. The implement 19 is replaced according to the required work.

[0034] The components of the work vehicle 10 will now be described. The work vehicle 10 has one vehicle body 11 and four running gears 12 for moving the vehicle body 11. The work vehicle 10 in this embodiment has a coupling device 15 attached to the vehicle body 11. The coupling device 15 is a device for connecting a work machine 19 to the vehicle body 11. The coupling device 15 has a lifting mechanism 70 for raising and lowering the work machine 19. The specific configuration of the coupling device 15 will be described later.

[0035] The coupling device 15 allows the work equipment 19 to be detached. The work vehicle 10 allows the coupling device 15 to be detached. If the work equipment 19 is not needed for the work vehicle 10, the work equipment 19 is detached from the coupling device 15. Furthermore, the coupling device 15 may be detached from the vehicle body 11. The work vehicle 10 can run with the coupling device 15 attached, even if the work equipment 19 has been detached, and the work vehicle 10 can also run with both the coupling device 15 and the work equipment 19 detached from the vehicle body 11.

[0036] The vehicle body 11 has a central frame 20 and a pair of side frames 21, 21 located on the left and right sides of the central frame 20. The left side frame 21 may be described as having the designation "21L", and the right side frame 21 may be described as having the designation "21R". The running gear 12, including the wheels 25, is mounted on the side frames 21. Each of the pair of side frames 21, 21 is displaceable relative to the central frame 20, and the work vehicle 10 can be deformed according to the work content or usage conditions such as the shape of the road surface.

[0037] Figures 7, 8, 9, and 10 are schematic diagrams showing a deformed work vehicle 10. As shown in Figures 7 and 8, the central frame 20 and the left side frame 21L and the right side frame 21R are each displaceable relative to each other in the left-right and up-down directions. The left side frame 21L and the right side frame 21R are each displaceable independently. The work vehicle 10 has displacement actuators 13 that allow the central frame 20 and the side frames 21L and 21R to be displaced relative to each other in the left-right and up-down directions.

[0038] The work vehicle 10 has left and right actuators 131 and up and down actuators 132 as displacement actuators 13. The left and right actuators 131 (see Figure 7) extend and retract, displacing the side frames 21L and 21R, respectively, in the left and right directions relative to the central frame 20. As a result, the work vehicle 10 changes the distance between the left and right wheels 25 according to the width of the furrows in the field, for example, and travels accordingly.

[0039] The vertical actuator 132 (see Figure 8) extends and retracts, displacing the central frame 20 vertically relative to the side frames 21L and 21R. The central frame 20 becomes higher than the side frames 21L and 21R. As a result, the work vehicle 10 changes the position of the central frame 20 vertically according to the height of the furrows in the field, for example, and travels while straddling the furrows.

[0040] The central frame 20 and the side frames 21L and 21R each only need to be displaceable in at least one of the left-right and up-down directions relative to each other. To this end, the work vehicle 10 only needs to have displacement actuators 13 in the direction that allows the side frames 21L and 21R to be displaced.

[0041] The longitudinal deformation of the vehicle body 11 occurs within the central frame 20. That is, as shown in Figure 10, the central frame 20 mounts the battery 16 (first battery 16A) and the case 205 that houses the battery 16. The case 205 can be displaced in the longitudinal direction by the longitudinal actuators 133. The battery 16 (first battery 16A) is heavy. As the battery 16 (first battery 16A) is displaced in the longitudinal direction within the central frame 20, the vehicle body 11 deforms, and its center of gravity can be changed. For example, when the work vehicle 10 travels on an inclined surface, it changes its center of gravity depending on its posture or depending on the work machine 19 it is connected to.

[0042] As another example of the deformation of the work vehicle 10 in the longitudinal direction (see Figure 9), the work vehicle 10 may have a longitudinal actuator 133 as a displacement actuator 13, and the longitudinal actuator 133 may extend and retract to relatively displace the central frame 20 and the side frames 21L and 21R, respectively, in the longitudinal direction. By displacing the central frame 20 in the longitudinal direction, the center of gravity of the vehicle body 11 can be changed.

[0043] Thus, in the configurations shown in Figures 7 and 8, the central frame 20 and the side frames 21L and 21R are each relatively displaceable in at least one of the left-right and up-down directions. The displacement actuator 13 displaces the central frame 20 and the side frames 21L and 21R relatively in at least one of the left-right and up-down directions. As shown in Figure 10, the central frame 20 has a case 205 that houses the battery 16 (first battery 16A). The case 205 is housed in the central frame 20 and is displaceable in the front-rear direction. The displacement actuator 13 displaces the case 205 in the front-rear direction within the central frame 20.

[0044] Each of the above-described forms of work vehicle 10 deforms its vehicle body 11 according to, for example, the shape of the road surface it is traveling on. The work vehicle 10 can operate with the work machine 19 while traveling with the vehicle body 11 deformed.

[0045] The work vehicle 10 (see Figures 2 to 5) has four running gears 12 located on the front, rear, left, and right sides of the vehicle body 11. The running gears 12 are attached to each of the left and right side frames 21. The left front running gear 12 may be described as "12LF", the right front running gear 12 as "12RF", the left rear running gear 12 as "12LR", and the right rear running gear 12 as "12RR".

[0046] Each running gear 12 has wheels 25, a motor 26 for driving, a reduction gear 27, and a power transmission unit 28 including gears and a shaft. The rotational force of the motor 26 is reduced by the reduction gear 27, and the reduced power is transmitted to the wheels 25 through the power transmission unit 28, causing the wheels 25 to rotate. As a result, the work vehicle 10 moves.

[0047] The left front running gear 12LF and the left rear running gear 12LR are mounted on the left side frame 21L, and together they constitute the left running unit UL. The left running unit UL includes the left second battery 16L, a subjunction box 24L, and inverters 31 connected to the two running motors 26, respectively, which are mounted on the side frame 21L. The right front running gear 12RF and the right rear running gear 12RR are mounted on the right side frame 21R, and together they constitute the right running unit UR. The right running unit UR includes the right second battery 16R, a sub-junction box 24R, and inverters 31 connected to the two running motors 26, respectively, which are mounted on the side frame 21R. The central frame 20 houses the first battery 16A, the hydraulic unit 17, and the main junction box 24A, and together these constitute the central unit UC. In this embodiment, as described above (see Figure 10), the case 205 housing the first battery 16A is displaced in the front-rear direction within the central frame 20. In contrast, the hydraulic unit 17 and other equipment, including the main junction box 24A, are not displaced in the front-rear direction.

[0048] The work vehicle 10 has steering actuators 29 that change the rolling direction of each of the four wheels 25 of the running gear 12 (see Figure 3). In this embodiment, the running gear 12 is supported by the side frame 21 and is capable of swinging around its vertical axis. The steering actuator 29 is mounted between the side frame 21 and the running gear 12. The steering actuator 29 changes the orientation of the running gear 12 by extending and retracting. This changes the rolling direction of the wheels 25, and thus changes the direction of travel of the work vehicle 10.

[0049] The work vehicle 10 includes a control device 14, a battery 16, a hydraulic unit 17, and a cooling unit 23. The control device 14 controls the operation of various components of the work vehicle 10, including the travel device 12 (motor 26), displacement actuator 13, steering actuator 29, hydraulic unit 17, and cooling unit 23.

[0050] Battery 16 is a rechargeable battery that can be discharged and recharged. Battery 16 supplies power to each piece of equipment on the work vehicle 10. In this embodiment (see Figure 6), the work vehicle 10 has one first battery 16A and two second batteries 16L and 16R. The first battery 16A is mounted on the central frame 20. One second battery 16L is mounted on the left side frame 21L, and the other second battery 16R is mounted on the right side frame 21R.

[0051] In this embodiment, the displacement actuator 13 and the steering actuator 29 are composed of hydraulic cylinders. The hydraulic unit 17 generates hydraulic pressure to extend and retract the hydraulic cylinders. The hydraulic unit 17 includes a tank for storing hydraulic fluid, a hydraulic pump, a motor 171 for driving the hydraulic pump, various valves, and hydraulic piping. The hydraulic unit 17 is mounted at the rear of the central frame 20.

[0052] The coupling device 15 (see Figure 4) has a hydraulic cylinder 811 as an actuator for raising and lowering the work equipment 19. The hydraulic unit 17 of the vehicle body 11 has hydraulic piping for supplying hydraulic pressure to the coupling device 15 (hydraulic cylinder 811). Furthermore, when the work equipment 19 is operated hydraulically, the hydraulic unit 17 has hydraulic piping for supplying hydraulic pressure to the work equipment 19. These hydraulic pipes (liquid pipes 36, see Figure 12) are connected to the vehicle-side coupling 44 of the vehicle body 11. The vehicle-side coupling 44 is located at the rear of the vehicle body 11 (central frame 20) and is provided at the lower fixing part 41.

[0053] When the coupling device 15 is attached to the fixing part 41 of the vehicle body 11, the coupling 88 (see Figure 13) of the coupling device 15 is connected to the vehicle-side coupling 44. The hydraulic piping (pipe 89) of the coupling device 15 is connected to the coupling 88, and hydraulic fluid from the hydraulic unit 17 is supplied to the hydraulic cylinder 811 of the coupling device 15 and the hydraulic equipment of the work machine 19 through the hydraulic piping (liquid piping 36, pipe 89).

[0054] The cooling unit 23 (see Figure 3) includes a first cooling unit 231 for cooling the battery 16 (16A, 16L, 16R), a second cooling unit 232 for cooling the motor 171 that drives the hydraulic pump of the hydraulic unit 17, and a third cooling unit 233 for cooling the motor 26 of the traveling device 12. Each cooling unit has a heat exchanger or the like for cooling the cooling medium.

[0055] The first cooling unit 231 and the second cooling unit 232 are mounted on the central frame 20 and are located in front of the first battery 16A. The third cooling unit 233 is mounted on the front of each of the side frames 21L and 21R. In this embodiment, the first cooling unit 231 is air-cooled, while the second cooling unit 232 and the third cooling unit 233 are water-cooled.

[0056] The work vehicle 10 (see Figure 6) has a junction box 24 and inverters 31 connected to each motor. In this embodiment, the junction box 24 has a main junction box 24A and sub-junction boxes 24L and 24R. The main junction box 24A is mounted on the central frame 20. The sub-junction boxes 24L and 24R are mounted on the side frames 21L and 21R. Each inverter 31 receives power from the main junction box 24A or the sub-junction boxes 24L and 24R and outputs a predetermined amount of power to each motor.

[0057] The work vehicle 10 has a charging port 32, a DC-DC converter 33, and an OBC / DC-DC converter 34. The DC-DC converter 33 transforms (steps down or steps up) the power supplied from the battery 16A to supply to other electrical equipment such as the control device 14. The OBC / DC-DC converter 34 includes an onboard charger and a DC-DC converter. The OBC / DC-DC converter 34 is connected to the charging port 32. The charging port 32 is mounted on the vehicle body 11 and is connected to an external power source located at a charging station or the like. The OBC / DC-DC converter 34 converts the power supplied from the charging port 32 into power to charge the battery 16A.

[0058] [Mounting structure of coupling device 15] As described above (see Figure 2), the work machine 19 is attached to the vehicle body 11 via the coupling device 15. The configuration for attaching the coupling device 15 to the vehicle body 11 will now be described. Figure 11 is a perspective view showing the rear of the vehicle body 11 and the coupling device 15 as shown in Figure 2. Figure 12 is a perspective view showing the coupling device 15 detached from the vehicle body 11. The vehicle body 11 has a fixing part 41 for attaching the coupling device 15 in a detachable manner. The fixing part 41 has a frame 42 and a mounting block 43.

[0059] The frame 42 is located at the lower part 201 of the vehicle body 11 and protrudes rearward from that lower part 201. Due to the configuration of this frame 42, the fixing part 41 extends from the vehicle body 11 toward the coupling device 15. The frame 42 is fixed to the lower part 201 of the central frame 20. Like the central frame 20, the frame 42 is made of metal and has high rigidity. The frame 42 is provided extending rearward from the lower part 201, and its shape is longer in the front-to-back direction than in the vertical direction. The frame 42 is constructed by combining multiple beam members and has a rectangular parallelepiped shape. The mounting block 43 is located at the rear end of the frame 42. The mounting block 43 is fixed to the frame 42 by welding or the like. The mounting block 43 is the part to which the coupling device 15 is attached.

[0060] As will be explained later, the coupling device 15 has a lifting mechanism 70 for raising and lowering the work equipment 19, as well as a first mounting section 71 and a second mounting section 72. The first mounting section 71 is the part that is attached to the work vehicle 10. In other words, the first mounting section 71 is attached to the mounting block 43 of the fixing section 41. The second mounting section 72 is the part to which the work equipment 19 is attached.

[0061] As shown in Figure 12, the mounting block 43 has a vehicle-side coupling 44. One or both of the liquid piping 36 and electrical wiring 37 extending from each piece of equipment mounted on the work vehicle 10 are connected to the vehicle-side coupling 44. In this embodiment, both the liquid piping 36 and electrical wiring 37 are connected to the vehicle-side coupling 44. The mounting block 43 has a recess 431 that opens to the rear, and the vehicle-side coupling 44 is provided in the recess 431. The coupling 88 of the coupling device 15, described later, is connected to the vehicle-side coupling 44 (see Figure 13).

[0062] The aforementioned liquid piping 36 consists of hydraulic piping 361 extending from the hydraulic unit 17 and liquid piping 362 for the work machine 19. The hydraulic fluid supplied from the hydraulic unit 17 flows through hydraulic piping 361 and is supplied from the vehicle-side coupling 44 to the hydraulic cylinder 811 of the lifting mechanism 70 of the coupling device 15. If the work machine 19 is, for example, a spraying device that sprays a liquid substance (chemicals or water), then the liquid piping 362 is a pipe for supplying that liquid to the work machine 19. A tank (not shown) for storing the liquid may be mounted on the vehicle body 11. The liquid piping 362 extending from the tank is connected to the vehicle-side coupling 44. The liquid in the liquid piping 362 is supplied from the vehicle-side coupling 44 to the work machine 19 through a relay pipe (not shown) provided by the coupling device 15.

[0063] The electrical wiring 37 includes, for example, a power wire 371 and a signal wire 372 for sensors, etc. The power wire 371 is a wire that supplies power from the battery 16 (first battery 16A) of the vehicle body 11 to the coupling device 15 and the work equipment 19 via the vehicle-side coupling 44. When the work equipment 19 requires power, the power from the battery 16 is supplied to the work equipment 19 from the vehicle-side coupling 44 to which the power wire 371 is connected, via the wires (not shown) of the lifting mechanism 70.

[0064] The signal line 372 is an electrical wire that connects the control device 14 of the vehicle body 11 to the vehicle-side coupling 44. If the work equipment 19 attached to the coupling device 15 has a sensor (not shown), the signal from that sensor is sent to the control device 14 through the signal line (not shown) of the coupling device 15 and the signal line 372 connected to the vehicle-side coupling 44. Based on this signal, the control device 14 performs control related to the work of the work equipment 19. For example, the lifting mechanism 70 is used to change the height of the work equipment 19.

[0065] The frame 42 of the fixed part 41 has an opening 421 through which a pipe or wiring extending from the vehicle-side coupling 44 to the vehicle body 11 passes. The pipe is the liquid pipe 36, and the wiring is the electrical wiring 37. In this embodiment, both the liquid pipe 36 and the electrical wiring 37 pass through the opening 421. As described above, the frame 42 is constructed by combining multiple beam members, and the space between these beam members forms the opening 421. In this embodiment, the opening 421 through which the liquid pipe 36 and electrical wiring 37 pass is located at the top of the frame 42. In other words, the frame 42 is constructed by four beam members that extend in the front-to-back direction, located at the top, bottom, left, and right. The space between the two upper beam members forms the opening 421 through which the liquid pipe 36 and electrical wiring 37 pass. The hydraulic piping and other fluid piping 36, and electrical wiring 37 extending from the hydraulic unit 17 are connected to the vehicle-side coupling 44 through an opening 421 in the frame 42. The hydraulic piping 36 and electrical wiring 37 may also pass through an opening on the side of the frame 42.

[0066] The position of the fixing part 41 on the work vehicle 10 will be described below. The vehicle body 11 (see Figures 4 and 5) has an operating device 35 that protrudes horizontally from its upper part 111. In this embodiment, the operating device 35 protrudes rearward from the upper part 111.

[0067] The operating device 35 is part of the equipment used to operate the work machine 19 or the coupling device 15. In this embodiment, the operating device 35 is part of the equipment of the hydraulic unit 17, and that equipment is a valve unit. The valve unit protrudes rearward from the upper part 111. The valve unit (operating device 35) is supported by a support member 202 of the central frame 20. The valve unit (operating device 35) includes a relief valve for releasing pressure in the event that excessive pressure occurs in the hydraulic piping.

[0068] When connecting a work implement 19 to the vehicle body 11 via a coupling device 15, for example, it may be necessary to adjust the relief pressure using the relief valve depending on the specifications of the work implement 19. Since the relief valve is provided protruding from the upper part 111 of the vehicle body 11, it is easy for the operator to access the relief valve, making adjustment and maintenance easy. If the operating device 35, such as the relief valve, is installed inside the vehicle body 11, it may become difficult to adjust and maintain the operating device 35.

[0069] As shown in Figures 4, 5, and 11, the fixed part 41 is provided below the operating device (valve unit) 35. The fixed part 41 is positioned vertically apart from the operating device 35. This configuration provides a space S1 between the upper operating device 35 and the lower fixed part 41. This space S1 can be used to perform maintenance on the operating device 35, the fixed part 41 (vehicle-side coupling 44), or the rear equipment 39 on the vehicle body side. Furthermore, the space S1 facilitates the attachment and detachment of the connecting device 15 to the fixed part 41.

[0070] As described above, the fixing portion 41 has a frame 42 that is long in the front-rear direction and protrudes from the lower part 201 of the vehicle body 11. The frame 42 extends the lower part of the vehicle body 11 in the rearward direction, and the coupling device 15 is attached to the mounting block 43 at the front end of the frame 42. Therefore, the mounting position P1 of the coupling device 15 is moved rearward from the vehicle body 11. The space S1 provided between the fixing part 41 and the coupling device 15 and the operating equipment 35 located above them is widened in the vertical and longitudinal directions. The space S1 is used as space for raising and lowering the work equipment 19 by the coupling device 15.

[0071] As shown in the plan view of Figure 3 and the perspective view of Figure 12, the entire fixed part 41 overlaps with the operating device 35 located above it in a plan view. However, the operating device 35 and the fixed part 41 may overlap in a plan view to some extent. This arrangement prevents either the operating device 35 or the fixed part 41 from protruding excessively to the rear, making the work vehicle 10 more compact.

[0072] The running gear 12, which has wheels 25, is located on both the left and right sides of the vehicle body 11. As shown in the side views of Figures 4 and 5, the mounting position P1 between the fixing part 41 and the coupling device 15 overlaps with a part of the rear running gear 12 in a side view. The mounting position P1 is the position in the front-rear direction of the joint surface between the fixing part 41 and the coupling device 15, and specifically (see Figure 12) is the position of the rear surface of the mounting block 43. The fixing part 41 does not protrude further rearward than the rear running gear 12. As shown in the side views of Figures 4 and 5, the mounting position P1 between the fixing part 41 and the coupling device 15 coincides with the two rear wheels 25 in a side view. In other words, the mounting position P1 is located between the left and right wheels 25. The fixing part 41 does not protrude further back than the wheels 25.

[0073] The mounting position P2 between the coupling device 15 and the work implement 19 is located behind the rear running gear 12 (wheels 25) in a side view. The mounting position P2 is the position in the front-rear direction of the joint surface between the coupling device 15 and the work implement 19, and specifically (see Figure 11) is the position of the rear surface of the second mounting portion 72 of the coupling device 15. Even when the vertically swinging work implement 19 is in its furthest forward position, the mounting position P2 is located behind the rear running gear 12 (wheels 25) in a side view and does not overlap with the rear running gear 12 (wheels 25). This mounting position P2 provides spaces S2 (see Figure 3) on both the left and right sides of the coupling device 15, and these spaces S2 can be used, for example, as space for the work machine 19.

[0074] [Connection device 15] The coupling device 15 is a device for connecting the work equipment 19 (see Figure 2) to the work vehicle 10. When attached to the vehicle body 11, the coupling device 15 connects the work equipment 19 to the vehicle body 11 and has a mechanism for raising and lowering the work equipment 19, and a mechanism for operating the work equipment 19. Figure 13 is a perspective view of the coupling device 15 as seen from the work vehicle 10 side. The coupling device 15 has a first mounting part 71 that is attached to the work vehicle 10, a second mounting part 72 for attaching the work machine 19, a motor 74 for the work machine 19, and a lifting mechanism 70. Furthermore, the coupling device 15 of this embodiment has an inverter 75 that outputs power to the motor 74. The mounting unit 18 of the coupling device 15 is composed of a first mounting section 71, a second mounting section 72, and a lifting mechanism 70. A motor 74 that outputs power to the work machine 19 is attached to the mounting unit 18. The lifting mechanism 70 raises and lowers the second mounting section 72 and the motor 74 relative to the first mounting section 71. The mounting unit 18 is the part for attaching the work machine 19 to the work vehicle 10 (vehicle body 11) so that it can be raised and lowered, and the lifting mechanism 70 makes it possible to raise and lower the motor 74 together with the work machine 19.

[0075] The first mounting portion 71 is attached to a fixing portion 41 of the central frame 20 of the vehicle body 11 (see Figure 11). The first mounting portion 71 is detachably attached to a mounting block 43 (see Figure 12) of the fixing portion 41. The mounting block 43 has an upper engaging portion 432 at its upper part and a lower engaging portion 433 at its lower part. In this embodiment, the upper engaging portion 432 is a recess that opens upward, and the lower engaging portion 433 is a recess that opens downward and to the rear.

[0076] As shown in Figure 13, the first mounting portion 71 has a mounting frame 77 that is long in the vertical direction. The mounting frame 77 has an upper fixing member 771 at its upper part and a lower fixing member 772 at its lower part. In this embodiment, the upper fixing member 771 is an axial member whose axis is in the left-right direction and is fixed to the upper part of the mounting frame 77, and the lower fixing member 772 is an axial member whose axis is in the left-right direction and is fixed to the lower part of the mounting frame 77.

[0077] The coupling device 15 is brought close to the mounting block 43 of the fixing part 41 from above, and after the upper fixing member 771 is fitted onto the upper engaging part 432 from above, the lower fixing member 772 is fitted onto the lower engaging part 433 from behind while the orientation of the coupling device 15 is changed. In this state, although not shown, a stopper pin built into the lower engaging part 433 pops out downward. When the lower fixing member 772, which is fitted into the recess of the lower engaging part 433, tries to move backward, the stopper pin contacts the lower fixing member 772 and restricts its movement. As a result, the coupling device 15 (mounting frame 77) is supported and connected to the fixing part 41 (mounting block 43).

[0078] When the stopper pin is moved upward (to the point where it is embedded in the lower engagement portion 433), the lower fixing member 772 becomes displaceable. This makes it possible to detach the mounting frame 77 of the coupling device 15 from the mounting block 43 of the fixing portion 41. With the above configuration, the coupling device 15 is connected to the fixing part 41 and is also detachable from the fixing part 41. In this embodiment, the mounting frame 77 of the coupling device 15 is connected to the fixing part 41 at the upper and lower positions by the upper fixing member 771 and the lower fixing member 772, making the connection strong.

[0079] Figure 14 is a perspective view of the coupling device 15 as seen from the work machine side (rear side). The second mounting section 72 is a frame structure for mounting the work machine 19. The second mounting section 72 is displaced vertically by the lifting mechanism 70. In this embodiment, the second mounting section 72 swings vertically relative to the first mounting section 71. The second mounting section 72 has a hitch frame 79 that facilitates the attachment and detachment of the implement 19. The hitch frame 79 has a common configuration with, for example, the hitch frame mounted on a conventional tractor. The hitch frame 79 allows for the attachment of conventional implements 19, and also facilitates the attachment and detachment of the implement 19.

[0080] The second mounting section 72 swings vertically by the lifting mechanism 70, thereby changing its vertical position and its orientation (angle of inclination) in the vertical direction. The motor 74 is mounted to the second mounting section 72 via a bracket 78, and the motor 74 and the second mounting section 72 are relatively unable to change their orientation. The motor 74 is supported by the bracket 78 from the left and right directions.

[0081] The motor 74 has a rotationally driven output shaft 741. The rear end of the output shaft 741 is located in front of the rear end of the second mounting portion 72. In other words, the output shaft 741 does not protrude rearward from the second mounting portion 72. The output shaft 741 is connected to the input shaft of the work implement 19. Since the work implement 19 does not have a motor, the motor 74 of the coupling device 15 outputs power to the work implement 19. The motor 74 may include a reduction gear if necessary. The vertical orientation of the motor 74 (output shaft 741) is changed to match the vertical position (orientation) of the second mounting portion 72, and is uniquely determined according to the vertical position (orientation) of the second mounting portion 72. When the work implement 19 is attached to the second mounting section 72, the input shaft of the work implement 19 becomes connected to the output shaft 741 of the motor 74 without the need for a universal joint, and this connection is maintained. The output of the motor 74 is then supplied to the input shaft of the work implement 19.

[0082] The lifting mechanism 70 includes a link mechanism 80 and an actuator 81. The link mechanism 80 in this embodiment includes one upper link member 85 and two lower link members 86, 86. The upper link member 85 has its first end 851 pivotably attached to a first mounting portion 71, and its second end 852 pivotably attached to a second mounting portion 72. Each of the two lower link members 86, 86 has its first end 861 pivotably attached to a first mounting portion 71, and its second end 862 pivotably attached to a second mounting portion 72.

[0083] The actuator 81 has two hydraulic cylinders 811 located on the left and right sides. The hydraulic cylinders 811 operate by receiving hydraulic fluid supplied from a hydraulic unit 17 mounted on the vehicle body 11 (see Figure 2). In this embodiment, the actuator 81 further has two arms 812 that are pivotably mounted on the upper part of the first mounting portion 71, and two rods 813 that connect the arms 812 to the lower link member 86. The rods 813 are pivotably mounted at both ends to the arms 812 and the lower link member 86, respectively.

[0084] Both ends of the hydraulic cylinder 811 are pivotably attached to the first mounting section 71 and the middle section of the arm 812, respectively. When the hydraulic cylinder 811 extends, the rod 813 lifts the lower link member 86, causing the second mounting section 72 to swing upward. When the hydraulic cylinder 811 retracts, the lower link member 86 is displaced downward, causing the second mounting section 72 to swing downward. With this link mechanism 80, the lifting mechanism 70 is constructed compactly.

[0085] As described above, the actuator 81 having a hydraulic cylinder 811 drives the lower link member 86 up and down relative to the first mounting portion 71, thereby raising and lowering the second mounting portion 72. Since the motor 74 is integrated with the second mounting portion 72, the lifting mechanism 70 causes the second mounting portion 72 and the motor 74 to move up and down relative to the first mounting portion 71.

[0086] The two lower link members 86, 86 are located below the upper link member 85 and on both the left and right sides of the upper link member 85 in a plan view. The motor 74 is located below the upper link member 85 and between the two lower link members 86, 86. In other words, the motor 74 is located in the space formed below the upper link member 85 and between the two lower link members 86, 86. The coupling device 15 is equipped with the motor 74, but the arrangement of the motor 74 as described above allows for efficient use of space, making it possible to configure the coupling device 15 compactly.

[0087] The link mechanism 80 and actuator 81 of the lifting mechanism 70 may have configurations other than those shown in the figure. The actuator 81 can be used to drive the lower link member 86 or the upper link member 85 up and down relative to the first mounting portion 71. The lifting mechanism 70 may have a configuration other than having a link mechanism 80, and if it does have a link mechanism 80, the shape and number of link members included therein can be changed.

[0088] As described above, the coupling device 15 of this embodiment has an inverter 75 that outputs power to the motor 74. In the coupling device 15, the motor 74 is located in the center in the left-right direction, and the inverter 75 is located on the left or right side in the left-right direction. In this embodiment, the inverter 75 is located to the right of the motor 74 in the coupling device 15. This arrangement makes the coupling device 15 more compact in the front-rear direction.

[0089] The motor 74 is attached to the second mounting section 72, while the inverter 75 is attached to the first mounting section 71. The motor 74 moves up and down together with the second mounting section 72, while the inverter 75 is attached to the first mounting section 71, which is fixed to the work vehicle 10 (fixed section 41), and does not move up or down. Therefore, the load on the lifting mechanism 70 (hydraulic cylinder 811) is small.

[0090] The motor 74 (see Figure 13) has a terminal box 743 on its front side, which is the side of the first mounting section 71. The electrical wiring 742 connected to the terminal block of the motor 74 extends from the terminal box 743 to the inverter 75 side. The inverter 75 has electrical wiring 751 connected to the motor 74 side. The electrical wiring 742 of the motor 74 and the electrical wiring 751 of the inverter 75 are electrically connected via a coupling 76. The coupling 76 connects the electrical wiring 742 connected to the motor 74 and the electrical wiring 751 connected to the inverter 75. The coupling 76 is attached to the upper link member 85. The fact that the coupling 76 is attached to the upper link member 85, which is exposed to the outside, facilitates maintenance such as replacing the inverter 75 or motor 74.

[0091] The coupling device 15 has a coupling 88 (coupling device side coupling 88). The coupling 88 is located on the first mounting portion 71 side of the coupling device 15. In this embodiment, the coupling 88 is provided on the mounting frame 77 of the first mounting portion 71. When the coupling device 15 is attached to the fixing part 41 (see Figure 12) of the vehicle body 11, the coupling 88 is connected to the vehicle-side coupling 44 at the same time.

[0092] As described above, the vehicle-side coupling 44 is connected to the liquid piping 36 and the electrical wiring 37. The coupling device 15 has a pipe 89 that is connected to the coupling 88 and connected to the liquid piping 36, and a wiring 90 that is connected to the coupling 88 and connected to the electrical wiring 37. When the coupling device 15 is attached to the fixed part 41 of the vehicle body 11, the coupling device side coupling 88 and the vehicle side coupling 44 are connected. Then, the hydraulic fluid supplied from the hydraulic unit 17 of the vehicle body 11 is delivered to the hydraulic cylinder 811 through the vehicle side coupling 44, the coupling device side coupling 88, and the piping 89.

[0093] If the work machine 19 is, for example, a spraying device that sprays a liquid substance (chemicals or water), then the piping 89 connected to the coupling 88 includes liquid piping. As described above, liquid piping 362 extending from a tank (not shown) for storing the spraying substance is connected to the vehicle-side coupling 44. The spraying substance in the liquid piping 362 is supplied to the work machine 19 from the vehicle-side coupling 44 and the coupling device-side coupling 88 through the relay piping of the coupling device 15.

[0094] Furthermore, when the coupling device 15 is attached to the fixing part 41 of the vehicle body 11, the coupling 88 and the vehicle-side coupling 44 are connected. As described above, a power wire 371 for supplying power from the battery 16 (first battery 16A) is connected to the vehicle-side coupling 44. Power from the battery 16 is supplied to the inverter 75 and motor 74, etc., through the power wire 371, the vehicle-side coupling 44, the coupling device-side coupling 88, and the wiring 90 of the coupling device 15.

[0095] The mounting frame 77 of the first mounting section 71 has an opening 87 (see Figure 13). The opening 87 is a hole that penetrates in the front-rear direction from the work vehicle 10 side to the work machine 19 side. The piping 89 and wiring 90 pass through this opening 87. The mounting frame 77 is large vertically, but the opening 87 allows for piping and wiring between the work vehicle 10 and the coupling device 15.

[0096] Thus, the coupling 88 of the coupling device 15 serves as a connector for connecting the liquid piping 36 (hydraulic piping 361, liquid piping 362 for the work machine 19) and electrical wiring 37 provided on the vehicle body 11 side. When attaching the coupling device 15 to the work vehicle 10, the coupling 88 facilitates the connection of necessary connections between the coupling device 15 and the work vehicle 10, such as the hydraulic piping 361 for the lifting mechanism 70, the liquid piping 362 for the work machine 19, the electrical wiring for the motor 74 of the coupling device 15, or the electrical wiring for the work machine 19.

[0097] As described above, the coupling device 15 of this embodiment is a device for coupling a work machine 19 to a work vehicle 10. The coupling device 15 has a mounting unit 18 that attaches the work machine 19 to the work vehicle 10 (vehicle body 11) so that it can be raised and lowered, and a motor 74 that outputs power to the work machine 19. The motor 74 is attached to the mounting unit 18. The mounting unit 18 raises and lowers the motor 74 together with the work machine 19. In this embodiment, the mounting unit 18 is composed of a first mounting portion 71, a second mounting portion 72, and a lifting mechanism 70 that raises and lowers the second mounting portion 72 and the motor 74 relative to the first mounting portion 71.

[0098] As described above, the coupling device 15 for connecting the work equipment 19 to the vehicle body 11 has a motor 74, and the output of the motor 74 is used to power the work equipment 19. Therefore, the work vehicle 10 and the work equipment 19 do not need a motor for work power. Since the work equipment 19 does not require a motor to operate itself, it is possible to connect a conventional work equipment 19 that does not have a motor to the work vehicle 10. Furthermore, the motor 74 is attached to a mounting unit 18 of the coupling device 15, and the motor 74 is raised and lowered together with the work implement 19 by this mounting unit 18. Therefore, the work implement 19 and the motor 74 are directly connected without the need for a power transmission mechanism with a complex configuration such as a universal joint, and the coupling structure is simplified.

[0099] The mounting unit 18 is detachable from the fixing part 41 of the work vehicle 10. In other words, the coupling device 15 is detachable from the work vehicle 10 (vehicle body 11). When the work vehicle 10 requires a work implement 19, it can be connected to the work implement 19 via the coupling device 15. Conversely, when the work vehicle 10 does not require the work implement 19, the work implement 19 can be detached from the coupling device 15, and the coupling device 15 can also be detached from the work vehicle 10. The work implement 19 and the coupling device 15 can be attached and detached according to the work, and the coupling device 15 makes it possible to increase the versatility of the work vehicle 10. By detaching the coupling device 15 from the work vehicle 10, maintenance of the work vehicle 10 becomes easier.

[0100] The work vehicle 10 can perform agricultural work and other tasks using the work machine 19 while it is in motion. The work machine 19 and coupling device 15 can be attached and detached depending on the application, resulting in a highly versatile work vehicle 10. Depending on the type of work implement 19 to be connected, the work performed by the work implement 19, or the state of that work, the lifting mechanism 70 changes the orientation of the mounting unit 18. In other words, the lifting mechanism 70 changes the orientation of the second mounting section 72 and the orientation of the work implement 19 attached to the second mounting section 72, and also makes it possible to change the output direction of the motor 74 (the axial direction of the output shaft 741).

[0101] As described above, the coupling device 15 has an inverter 75 that outputs power to the motor 74. The rotation of the motor 74 is controlled by the inverter 75. For example, if the specifications of the motor 74, such as its output, need to be changed according to the work equipment 19, and the inverter 75 is mounted inside the work vehicle 10, then this operation would be relatively difficult. In contrast, in this embodiment, the inverter 75 is mounted on the exposed coupling device 15. Therefore, the operation of changing the specifications as described above becomes easier.

[0102] [Cover 95 of the fixing part 41] Figure 15 is an explanatory diagram of the rear of the work vehicle 10. As described above, the vehicle body 11 has a fixing part 41 to which a coupling device 15, which is another piece of equipment, is attached detachably. The fixing part 41 has a vehicle-side coupling 44 for connecting the liquid piping 36 and electrical wiring 37 provided on the vehicle body 11. The vehicle-side coupling 44 has a connection port for connecting the coupling 88 (see Figure 13) on the coupling device 15 side.

[0103] The fixed part 41 includes a cover 95 and a cover actuator 96. The cover actuator 96 switches the cover 95 between a first state and a second state. Figure 16 shows the case where the cover 95 is in the first state, and Figure 15 shows the case where the cover 95 is in the second state. In the first state, the cover 95 covers the connection port side of the vehicle-side coupling 44 of the fixed part 41, and in the second state, it opens the connection port side of the vehicle-side coupling 44 of the fixed part 41. The operation of the cover actuator 96 is controlled by a control device 14 (see Figure 6) of the work vehicle 10.

[0104] The cover 95 shown in Figures 15 and 16 has multiple horizontally elongated strip-shaped slats 951 and has a shutter curtain structure. The cover actuator 96 has a motor for winding up such a cover 95. Although not shown, the fixing part 41 may have rails that guide the opening and closing operation of the cover 95 (multiple slats 951). The fixed part 41 has a storage section (storage box) 97 for storing the cover 95 in the second state (see Figure 15). The cover 95 in the second state is stored in the storage section 97. The cover actuator 96, which has a motor, is housed in the storage section 97.

[0105] When the coupling device 15 is attached to the fixed part 41, the cover actuator 96 sets the cover 95 to the second state, and the rear of the fixed part 41 is left open. If the coupling device 15 cannot be attached to the fixed part 41, the cover actuator 96 sets the cover 95 to its first state, and the fixed part 41 is covered by the cover 95. Having the cover 95 in the first state improves the appearance and prevents foreign matter from adhering to the vehicle-side coupling 44.

[0106] The cover 95 may be configured to cover only the vehicle-side coupling 44, but in this embodiment, it covers the entire fixing portion 41. As described above, the fixing portion 41 has an upper engaging portion 432 as a coupling portion for mechanically connecting the coupling device 15. The upper engaging portion 432 is an upward-opening recess provided in the mounting block 43 of the fixing portion 41. As shown in Figure 16, the cover 95 covers the vehicle-side coupling 44 and the upper engaging portion 432, which is the coupling portion. The cover 95 may also be configured to cover the lower engaging portion 433, which is a coupling portion for mechanically connecting the coupling device 15.

[0107] Figures 17 and 18 are explanatory diagrams showing modified examples of the cover 95. The cover 95 shown in Figures 17 and 18 is plate-shaped. Figure 17 shows the cover 95 in the first state, covering the connection port side of the vehicle-side coupling 44 of the fixing part 41. Figure 18 shows the cover 95 in a state between the first state and the second state. The cover actuator 96 performs the operation of pulling the cover 95 into the storage part (storage box) 97 or sending it out from the storage part 97. The cover actuator 96 is configured, for example, with a retractable cylinder.

[0108] The opening and closing of the cover 95, that is, the operation of the cover actuator 96, will now be described. The cover actuator 96 starts opening and closing the cover 95 when predetermined conditions are met. The operation of the cover actuator 96 is controlled by the control device 14, and the opening and closing of the cover 95 is performed automatically. The aforementioned predetermined conditions are conditions relating to the state or operation of the vehicle body 11, conditions relating to the positional relationship between the vehicle body 11 and the coupling device 15, or conditions relating to the identification of the coupling device 15. Each of these cases will be explained below.

[0109] When the coupling device 15 is not attached to the fixing part 41 of the vehicle body 11, and the fixing part 41 and the coupling device 15 are in a position that is relatively close to each other, the vehicle body 11 starts moving using the running gear 12 (operation of the vehicle body 11) and approaches the coupling device 15 (the aforementioned positional relationship), the cover actuator 96 starts operating and opens the cover 95. Conversely, when the coupling device 15 is attached to the fixing part 41, and the coupling device 15 is detached from the fixing part 41, and the vehicle body 11 starts moving with the running gear 12 (operation of the vehicle body 11), and moves away from the coupling device 15 (the aforementioned positional relationship), the cover actuator 96 starts operating and closes the cover 95.

[0110] In this manner, when the coupling device 15 is not attached to the fixed part 41, if the vehicle body 11 and the coupling device 15 change relative positions, the cover actuator 96 operates to open and close the cover 95. When the conditions for the operation of the vehicle body 11 and the conditions for the positional relationship between the vehicle body 11 and the coupling device 15 are met, the opening and closing of the cover 95 is automatically started. The vehicle body 11 has a detection device 92 such as a camera (see Figure 1), and the positional relationship is detected by the detection device 92.

[0111] Another example of the operation of the cover actuator 96 will be described. The work vehicle 10 (control device 14) stores various operation programs, and these operation programs include an operation program that automatically connects and disconnects the coupling device 15. With the coupling device 15 not yet attached to the fixing part 41, when the vehicle body 11 proceeds to the operation step for connecting with the coupling device 15 according to the operation program, the cover actuator 96 starts operating and opens the cover 95. Conversely, with the coupling device 15 attached to the fixed part 41, an operation is performed to disconnect the fixed part 41 from the coupling device 15 according to the operation program, and then, when the operation proceeds to separate the vehicle body 11 from the coupling device 15, the cover actuator 96 starts to operate and closes the cover 95.

[0112] Thus, when the vehicle body 11 proceeds to an operation step for connecting with the coupling device 15, or an operation step after disconnecting from the coupling device 15, according to the set operation program, the cover actuator 96 starts operating. When the conditions related to the state of the vehicle body 11, based on the operating program, are met, the opening and closing of the cover 95 is automatically initiated.

[0113] Let's describe yet another example of the operation of the cover actuator 96. The vehicle body 11 has a detection device 92 such as a camera (see Figure 1). If the coupling device 15 is not attached to the fixing part 41, and the detection device 92 detects the coupling device 15 or identification information such as a mark attached to the coupling device 15, the cover actuator 96 will start to operate and the cover 95 will open. When the detection device 92 can no longer detect the coupling device 15 or the identification information attached to the coupling device 15, the cover actuator 96 starts to operate and closes the cover 95.

[0114] Thus, when the detection device 92 detects the coupling device 15 or identification information of the coupling device 15, the cover actuator 96 starts operating. When the conditions for identifying the coupling device 15 are met, the opening and closing of the cover 95 is automatically initiated.

[0115] As described above, the fixed part 41 of the work vehicle 10 in this embodiment includes a vehicle-side coupling 44, a cover 95, and a cover actuator 96 that switches the cover 95 between a first state and a second state. In the first state, the cover 95 covers the connection port side of the vehicle-side coupling 44, and in the second state, it opens the connection port side of the vehicle-side coupling 44. Even when the work vehicle 10 is used in an outdoor environment with a lot of foreign matter such as soil dust and other debris, such as a farm, if the work machine 19 is not connected to the fixed part 41, the fixed part 41 having the vehicle-side coupling 44 is protected by the cover 95, making it possible to prevent malfunctions.

[0116] 〔others〕 In the above embodiment, the coupling device 15 is attached to the rear of the vehicle body 11. The mounting position of the coupling device 15 on the vehicle body 11 may be other. For example, the coupling device 15 may be attached to the front of the vehicle body 11, in which case the work equipment 19 is also located in front of the vehicle body 11. Alternatively, the coupling device 15 may be attached to the right or left of the vehicle body 11, in which case the work equipment 19 is also located to the right or left of the vehicle body 11. Alternatively, the coupling device 15 may be attached to any other position on the vehicle body 11.

[0117] Furthermore, the vehicle body 11 may have multiple fixing parts 41 for attaching the coupling device 15 at various locations. For example, the vehicle body 11 may have fixing parts 41 at each of its four positions: front, rear, left, and right. In this case, for example, the coupling device 15 may be attached to one or both sides of the vehicle body 11 in the front-rear direction, and to one or both sides in the left-right direction. Multiple work machines 19, each attached to one or both sides of the vehicle body 11 in the front-rear direction, and to one or both sides in the left-right direction, may then perform their respective tasks.

[0118] The embodiments described above are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than by the embodiments, and includes all modifications within the scope equivalent to the configurations described in the claims. [Explanation of Symbols]

[0119] 10 Work Vehicles 11. Vehicle body 12. Traveling device 13. Displacement Actuator 15 Coupling device 16 batteries 18 Mounting Unit 19. Work equipment 20 Central Frame 21L, 21R Side Frame 70 Lifting mechanism 71 First mounting section 72 Second mounting section 74 Motor 75 Inverter 76. Finalist 77 Mounting frame 78 brackets 79 Hitch Frame 80 Link Mechanism 81 Actuator 85 Upper link member 86 Lower link member 87 Opening 88 Coupling (Coupling on the coupling device side) 205 cases 771 Upper fixing material 772 Lower fixing material 851 First end 852 Second end 861 First end 862 Second end

Claims

1. The vehicle body and A running device for moving the vehicle body, A coupling device for connecting the work equipment to the vehicle body, It has, The coupling device is A mounting unit for attaching the aforementioned work machine to the vehicle body so that it can be raised and lowered, A motor that outputs power to the aforementioned work machine, It has, The motor is attached to the mounting unit. The mounting unit raises and lowers the motor together with the work machine. Work vehicle.

2. The mounting unit is detachable from the vehicle body. The work vehicle according to claim 1.

3. The aforementioned vehicle body is The central frame and It has a pair of side frames located on both sides of the central frame and displaceable relative to the central frame, The aforementioned traveling device is attached to each of the pair of side frames, The central frame and the side frame are provided with a displacement actuator that allows them to be displaced relative to each other in at least one of the left-right and up-down directions. A work vehicle according to claim 1 or claim 2.

4. The aforementioned vehicle body is A central frame having a battery and a case for housing the battery, A pair of side frames located on both sides of the central frame and to which the traveling device is attached, It has, The aforementioned case is displaceable in the front-rear direction and is housed in the central frame. A work vehicle according to claim 1 or claim 2.

5. A coupling device for connecting a work machine to a work vehicle, A mounting unit for attaching the aforementioned work machine to the work vehicle so that it can be raised and lowered, A motor that outputs power to the aforementioned work machine, It has, The motor is attached to the mounting unit. The mounting unit raises and lowers the motor together with the work machine. Coupling device.

6. The mounting unit is detachable from the work vehicle. The coupling device according to claim 5.

7. The aforementioned mounting unit is A first mounting part to be attached to the aforementioned work vehicle, A second mounting section for attaching the aforementioned work implement, The coupling device according to claim 5 or claim 6, further comprising a lifting mechanism for raising and lowering the second mounting portion and the motor relative to the first mounting portion.

8. The lifting mechanism comprises a link mechanism and an actuator. The link mechanism has an upper link member and a lower link member, the first end of which is attached to the first mounting portion and the second end of which is attached to the second mounting portion. The actuator drives the lower link member or the upper link member up and down relative to the first mounting portion. The coupling device according to claim 7.

9. The motor has an inverter that outputs power to the motor, The coupling device according to claim 5 or claim 6.

10. The motor has an inverter that outputs power, The lifting mechanism comprises a link mechanism and an actuator. The link mechanism has an upper link member and a lower link member, the first end of which is attached to the first mounting portion and the second end of which is attached to the second mounting portion. The actuator drives the lower link member or the upper link member to move up and down relative to the first mounting portion. The coupling connecting the electrical wiring connected to the motor and the electrical wiring connected to the inverter is attached to the upper link member. The coupling device according to claim 7.

11. The link mechanism comprises the upper link member and two lower link members located below the upper link member and on both sides of the upper link member in a plan view. The coupling device according to claim 8, wherein the motor is located below the upper link member and between the two lower link members.

12. When the direction of travel of the aforementioned work vehicle is defined as the front-to-back direction, and the horizontal direction perpendicular to the front-to-back direction is defined as the left-to-right direction, The motor is located in the center in the left-right direction. The inverter is located on the left or right side in the left-right direction. The coupling device according to claim 9.

13. The motor has an inverter that outputs power, The inverter is attached to the first mounting portion, The motor is attached to the second mounting portion. The coupling device according to claim 7.

14. Located on the side of the first mounting portion, and having a coupling for connecting one or both of the liquid piping and electrical wiring, The coupling device according to claim 7.

15. The first mounting portion has a mounting frame that is long in the vertical direction, including an upper fixing member and a lower fixing member that connect to the fixing portion of the work vehicle. The mounting frame has an opening that penetrates in the front-rear direction from the work vehicle side to the work machine side. The coupling device according to claim 7.

Images