Work vehicle

Abstract

To provide a work vehicle in which a posture of a work device can be set to an appropriate state according to a situation.SOLUTION: The present invention includes: a vehicle body capable of traveling; and a connection mechanism that is attached to the vehicle body and connects and supports a work device. The connection mechanism includes: a pair of lower links each having a first end portion rotatably connected to the vehicle body around an axial line extending in a width direction of the vehicle body and a second end portion opposite to the first end portion, the pair of lower links being arranged at an interval in the width direction of the vehicle body, in which the work device is directly or indirectly connected to the second end portion; and a pair of actuators arranged correspondingly to the pair of lower links, respectively and each being configured to swing a corresponding one of the lower links with the axial line as a center. Each of the pair of actuators can actuate independently.SELECTED DRAWING: Figure 21

Description

Technical Field

[0001] The present invention relates to a work vehicle provided with a coupling mechanism for coupling and supporting a work device that performs a predetermined work.

Background Art

[0002] Conventionally, a work vehicle such as a tractor is provided with a coupling mechanism for coupling a work device that performs work while traveling. Further, in this type of work vehicle, when the work vehicle tilts in the width direction during traveling due to the influence of the terrain or the like, the coupling mechanism is operated to maintain the posture of the work device in an appropriate posture (horizontal state) contrary to the posture of the work vehicle (see, for example, Patent Document 1).

[0003] Specifically, the coupling mechanism is a pair of lower links each having a first end rotatably coupled to the vehicle body about an axis extending in the width direction of the vehicle body and a second end opposite to the first end, and the pair of lower links are arranged at intervals in the width direction of the vehicle body, and a left and right pair of lower links to which the work device is directly or indirectly coupled to the second end, and a lift cylinder that rotates one of the pair of lower links and raises and lowers the second end of the one lower link. The pair of lower links are symmetrically arranged in the width direction of the vehicle body with respect to the center of the vehicle body of the work vehicle. Thereby, in the coupling mechanism configured as described above, the work device is coupled to each of the second ends of the pair of lower links, so that two positions in the width direction of the work device are supported.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the posture maintenance function, the work vehicle with the above configuration extends and contracts the lift cylinder to raise and lower the second end of one of the lower links, thereby maintaining the posture of the work device in a horizontal state against the posture (tilt) of the work vehicle. Therefore, the work device connected to the work vehicle tilts in the width direction with the second end of the other lower link (the other of the two locations supporting the work device) as the fulcrum (center). That is, the work vehicle (connection mechanism) with the above configuration restores the posture of the work device around a position deviated from the center of the vehicle body in the width direction of the work vehicle (fulcrum).

[0006] Therefore, when the work vehicle tilts around the center in the width direction of the vehicle body, there is a limit to making the posture of the work device conform to the situation (posture) of the work vehicle. In addition, since there is a limit to the swing range of one of the lower links, there is also a limit to maintaining the posture of the work device.

[0007] Therefore, the present invention provides a work vehicle capable of bringing the posture of the work device into an appropriate state according to the situation.

Means for Solving the Problems

[0008] The work vehicle of the present invention includes a travelable vehicle body and a connection mechanism attached to the vehicle body, the connection mechanism being a connection mechanism for connecting and supporting a work device. The connection mechanism includes a pair of lower links each having a first end rotatably connected to the vehicle body around an axis extending in the width direction of the vehicle body and a second end opposite to the first end, the pair of lower links being spaced apart in the width direction of the vehicle body, and the work device being directly or indirectly connected to the second end; and a pair of actuators arranged corresponding to each of the pair of lower links, each actuator being an actuator for swinging the corresponding lower link around the axis. The pair of actuators can operate independently of each other.

[0009] As one aspect of the present invention, each of the pair of actuators is a cylinder device configured to be expandable and contractible in one direction and having an electric motor driven to expand and contract itself, and is arranged to straddle the corresponding lower link and the vehicle body, and both ends in the one direction may be connected to the lower link and the vehicle body.

[0010] As another aspect of the present invention, each of the pair of actuators may be an electro-hydraulic cylinder including a hydraulic pump that discharges hydraulic oil to expand and contract itself, and the hydraulic pump is driven by the electric motor.

[0011] A plurality of connection positions connectable to at least one of the lower link and the actuator are set in at least one of the lower link and the actuator, and the connection mechanism may include an angle sensor that detects a rotation angle about the axis of each of the pair of lower links.

[0012] The connection mechanism is a connection frame that connects the second ends of the pair of lower links, and has a connection frame including a latching portion capable of latching the working device, and both ends of the connection frame may be supported by the second ends of the pair of lower links via spherical bearings.

[0013] The connection mechanism may be a pair of latching members capable of latching the working device, and has a pair of latching members connected to the second ends of the pair of lower links respectively.

[0014] The connection mechanism has an upper link disposed above the pair of lower links, and the upper link includes a base end portion rotatably connected to the vehicle body about an axis extending in the width direction, and a tip end portion opposite to the base end portion, and the tip end portion may be rotatably connected to the connection frame about an axis extending in the width direction.

[0015] The connecting mechanism has an upper link disposed above the pair of lower links. The upper link has a base end portion rotatably connected to the vehicle body about an axis extending in the width direction, and a tip end portion opposite to the base end portion. The tip end portion of the upper link may be capable of latching the working device.

Advantages of the Invention

[0016] According to the present invention, the posture of the working device can be adjusted to an appropriate state according to the situation.

Brief Description of the Drawings

[0017]

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Mode for Carrying Out the Invention

[0018] Hereinafter, a work vehicle according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the work vehicle and the working device connected to the work vehicle will be described separately.

[0019] First, the work vehicle will be described. As shown in FIGS. 1 and 2, the work vehicle A is a travelable vehicle. The work vehicle A according to the present embodiment is a so-called tractor, and includes a travelable vehicle body 1 and a coupling mechanism 2 attached to the vehicle body 1 for coupling and supporting a working device B for performing a predetermined work.

[0020] More specifically, the work vehicle A includes a vehicle body 1, a traveling device 3 that supports the vehicle body 1 so as to be travelable, and a coupling mechanism 2 that couples and supports the working device B. The work vehicle A also includes a control device 4 that controls the operations of the traveling device 3 and the working device B. Further, as shown in FIG. 2, the work vehicle A includes an attitude detection device 5 that detects the inclination (attitude) of the vehicle body 1 in a direction orthogonal to the direction in which the vehicle body 1 travels straight (travels straight forward or backward) and the vertical direction.

[0021] In the following description, the direction in which the vehicle body 1 moves straight ahead (travels straight forward or backward) and the corresponding direction are referred to as the "first direction". The side on which the vehicle body 1 (work vehicle A) moves forward in the first direction is referred to as the "front", and the side on which the vehicle body 1 (work vehicle A) moves backward in the first direction is referred to as the "rear". Furthermore, the direction orthogonal to the front-rear direction and the up-down direction (the direction corresponding to the vehicle width of the vehicle body 1) is referred to as the "second direction". In accordance with this definition of direction, the up-down direction is referred to as the "third direction". Also, since the work device B is connected to the work vehicle A, in the description of the work device B as well, the above definitions are used based on the state of being connected to the work vehicle A. Accordingly, in each figure, the first direction, the second direction, and the third direction are supplementarily illustrated using two orthogonal axes.

[0022] As shown in FIG. 1, the vehicle body 1 has a driver's seat 10 on which an operator rides and a driver's seat protection mechanism 11 that covers the driver's seat 10. The work vehicle A (vehicle body 1) has an operating device (hereinafter referred to as the first operating device) 12 for operating the traveling device 3, a display device 13 for displaying various information, and the like. Also, since the work device B is connected to the work vehicle A according to the present embodiment, the vehicle body 1 has an operating device (hereinafter referred to as the second operating device) 14 for operating the connected work device B.

[0023] In the present embodiment, the driver's seat protection mechanism 11 is a cabin that covers the entire driver's seat 10 and defines a driver's cab DR in which the operator stays during work (travel). The first operating device 12, the display device 13, the second operating device 14, etc. are arranged at positions where they can be operated by the operator seated on the driver's seat 10 inside the driver's cab DR. The first operating device 12, the display device 13, and the second operating device 14 are electrically connected to the control device 4 (see FIG. 8).

[0024] In the present embodiment, as shown in FIGS. 1 and 2, the traveling device 3 includes a prime mover 30 for traveling, a drive wheel 31 driven by the prime mover 30 for traveling, and a steering wheel 32 for determining the traveling direction. The prime mover 30 for traveling employs an internal combustion engine or an electric motor. In the present embodiment, a diesel engine, which is an internal combustion engine, is employed as the prime mover 30 for traveling. The prime mover 30 for traveling is disposed in front of the driver's seat protection mechanism 11.

[0025] Specifically, the work vehicle A includes a bonnet 15 that defines a prime mover housing chamber ER for housing the prime mover 30 for traveling. The bonnet 15 is disposed in front of the driver's seat protection mechanism 11 (driver's cab DR) and at a position that does not block the view of the operator from within the driver's seat protection mechanism 11 (driver's cab DR) (a position lower than the lower end of the front window FW). Accordingly, the prime mover 30 for traveling is disposed within the bonnet 15 (within the prime mover housing chamber ER), so as to be in front of the driver's seat protection mechanism 11 (driver's cab DR) and at a position that does not block the view of the operator from within the driver's seat protection mechanism 11 (driver's cab DR) (a position lower than the lower end of the front window FW).

[0026] When an electric motor is employed as the prime mover 30 for traveling, the work vehicle A is equipped with a battery for storing electric power supplied to the electric motor serving as the prime mover 30 for traveling, a generator for generating the electric power stored in this battery, and an internal combustion engine for power generation that drives the generator. Note that, in addition to a diesel engine, a gasoline engine, a hydrogen engine, or the like may be employed as the internal combustion engine serving as the prime mover 30 for traveling or the internal combustion engine for power generation.

[0027] As shown in FIG. 1, the first operation device 12 includes a steering wheel 12a for steering the steering wheel 32, an accelerator device 12b for operating the output of the drive wheel 31 (prime mover 30 for traveling), and the like.

[0028] The display device 13 displays various information. That is, the display device 13 displays information regarding the work vehicle A and information regarding the work device B that is connected. In the present embodiment, the display The position 13 is equipped with a touch panel monitor, and necessary information can also be inputted.

[0029] The second operating device 14 is for the operator to operate on the connecting mechanism 2 and the working device B. That is, the second operating device 14 is operated by the operator regarding the operations of the connecting mechanism 2 and the working device B (for example, the working device B equipped with the prime mover 7a). The second operating device 14 is electrically connected to the control device 4 (see FIG. 8). Accordingly, the second operating device 14 outputs the content operated by the operator to the control device 4 as an electrical signal. Note that the second operating device 14 is composed of any one of various switches such as a joystick, a dial switch, a lever switch, and a slide switch, or a combination of two or more of various switches. Also, as in this embodiment, when a touch panel monitor is adopted for the display device 13, the display device 13 may be used also as the second operating device 14.

[0030] As shown in FIGS. 2 and 3, the connecting mechanism 2 is connected (attached) to the vehicle body 1. In this embodiment, the connecting mechanism 2 is attached to the rear part of the vehicle body 1 (behind the driver's seat protection mechanism 11).

[0031] Specifically, the connecting mechanism 2 includes a pair of lower links 20R, 20L each having a first end 20a and a second end 20b on the opposite side of the first end 20a, which are rotatably connected around an axis extending in a second direction with respect to the vehicle body 1, and are arranged at intervals in the second direction, and the working device B is directly or indirectly connected to the second end 20b; and a pair of actuators 21R, 21L arranged corresponding to each of the pair of lower links 20R, 20L, each of which swings (rotates) the corresponding lower link 20R, 20L around the first end 20a (axis).

[0032] In addition to the above configuration, the linkage mechanism 2 has an upper link 22 disposed above the pair of lower links 20R and 20L. Further, in the present embodiment, the linkage mechanism 2 has a pair of latching members 23R and 23L capable of latching the working device B, and the pair of latching members 23R and 23L are connected to the second ends 20b and 20b of the pair of lower links 20R and 20L, respectively. Furthermore, the linkage mechanism 2 has a connecting frame 24 that connects the second ends 20b and 20b of the pair of lower links 20R and 20L, and the connecting frame 24 includes a latching portion 25 capable of latching the working device B. As shown in FIG. 3, the linkage mechanism 2 has a pair of angle sensors S3 and S3 disposed corresponding to the pair of lower links 20R and 20L, respectively, and the pair of angle sensors S3 and S3 detect the rotation angles of the pair of lower links 20R and 20L around their respective rotation (oscillation) centers.

[0033] In the present embodiment, since the linkage mechanism 2 is connected to the rear portion of the vehicle body 1, each of the pair of lower links 20R and 20L and the upper link 22 extends in the direction from the rear portion of the vehicle body 1.

[0034] As shown in FIG. 2, the pair of lower links 20R and 20L are symmetrically arranged with respect to a virtual plane (hereinafter referred to as this virtual plane as the virtual reference plane) VS that extends in the first direction and the third direction along a vehicle body center line (hereinafter referred to as the longitudinal center line) CL that extends in the first direction at the center of the vehicle body 1 in the second direction. The first ends 20a and the second ends 20b of the pair of lower links 20R and 20L each extend straight in the first direction. The first ends 20a of the pair of lower links 20R and 20L are pivotally connected to the vehicle body 1 via an axis extending in the second direction and are rotatable around the axis (axis line extending in the second direction).

[0035] In the present embodiment, each of the pair of lower links 20R and 20L has a first end 20a a first inclined portion 20c that is inclined outward in the second direction as it extends rearward, and a straight portion 20d that extends straight rearward (in the same direction as the front-rear center line CL) from the first inclined portion 20c and is directly or indirectly connected to the second end portion 20b. In the present embodiment, for each of the pair of lower links 20R and 20L, since the second end portion 20b is located outward in the second direction from the straight portion 20d, it further has a connecting portion 20e that connects the straight portion 20d and the second end portion 20b, and the straight portion 20d and the second end portion 20b are indirectly connected via the connecting portion 20e. Note that the connecting portion 20e is inclined outward in the second direction as it extends rearward.

[0036] As shown in FIG. 3, each of the pair of lower links 20R and 20L has a plurality of connection positions H1 and H2 that connect the corresponding actuators 21R and 21L. Specifically, a plurality of pin insertion holes H1... for inserting pins for connecting the actuators 21R and 21L are formed in the straight portion 20d of each of the pair of lower links 20R and 20L. Each of the plurality of pin insertion holes H1... is a through hole that penetrates in the second direction. The plurality of pin insertion holes H1... (connection positions) are arranged at a predetermined interval in the extending direction of the straight portion 20d.

[0037] Each of the latching members 23R and 23L has a notch portion 230R and 230L that is open upward and recessed downward, and the notch portion 230R and 230L can fit the shaft portion 242 of the connecting frame 24 or a lower connecting shaft 85 (described later) of the working device B from above. In the present embodiment, the notch portions 230R and 230L of the latching members 23R and 23L correspond to the shaft portion 242 of the connecting frame 24.

[0038] The upper link 22 is disposed above the pair of lower links 20R and 20L. The upper link 22 is disposed between the pair of lower links 20R and 20L in the second direction. Specifically, there is one upper link 22, and it is arranged so as to overlap with the front-rear center line CL in the third direction (on the virtual reference plane VS). The upper link 22 extends in one direction and has a base end portion 22a and a tip end portion 22b in one direction (longitudinal direction). The base end portion 22a of the upper link 22 is rotatably connected to the vehicle body 1 around an axis extending in the second direction. The working device B is directly or indirectly connected to the tip end portion 22b of the upper link 22. In the present embodiment, the tip end portion of the upper link 22 has a notch portion 22c into which a rod body extending in the second direction can be fitted. Thereby, the tip end portion 22b of the upper link 22 can directly or indirectly connect the working device B in a latched state by fitting the locking pin 243b (described later) of the latching portion 25 of the connecting frame 24 or the upper connecting shaft 87 of the connecting portion 80 (described later) of the working device B into the notch portion 22c.

[0039] The pair of actuators 21R and 21L can operate independently. Each of the pair of actuators 21R and 21L is a cylinder device configured to be extendable and contractible in one direction. In the present embodiment, each of the pair of actuators 21R and 21L is a cylinder device having an electric motor 26 that is driven for its own extension and contraction, as shown in FIG. 4.

[0040] Specifically, the pair of actuators (cylinder devices) 21R and 21L includes fluid cylinders 27 that extend and contract by supply and discharge of fluid.

[0041] The fluid cylinder 27 includes a cylindrical cylinder tube 270 and a piston rod 271 including a rod-shaped rod 271a and a piston 271b connected to one end of the rod 271a. The piston 271b is installed inside the cylinder tube 270, and the other end side of the rod 271a protrudes from one end of the cylinder tube 270. The fluid cylinder 27 supplies and discharges fluid to and from one end side and the other end side inside the cylinder tube 270 with the piston 271b as a boundary, so that the rod 271a of the piston rod 271 extends and retracts from one end of the cylinder tube 270 and expands and contracts as a whole. In the present embodiment, the fluid supplied and discharged to and from one end side and the other end side inside the cylinder tube 270 is oil (hydraulic oil). That is, in the present embodiment, the fluid cylinder 27 is a hydraulic cylinder.

[0042] Furthermore, in addition to the electric motor 26 and the hydraulic cylinder (fluid cylinder) 27, the cylinder devices 21R and 21L include a hydraulic system 28 including a hydraulic pump 280 that supplies and discharges hydraulic oil to and from one end side and the other end side of the cylinder tube 270 of the hydraulic cylinder 27. That is, the cylinder devices 21R and 21L are electro-hydraulic cylinders in which the hydraulic cylinder 27, the hydraulic system 28, and the electric motor 26 that drives the hydraulic pump 280 of the hydraulic system 28 are integrated (packaged).

[0043] There are various types of hydraulic pumps 280, but in the present embodiment, a gear pump is adopted. The hydraulic system 28 includes a first oil passage 281 connecting the hydraulic pump 280 and one end side of the cylinder tube 270, and a second oil passage 282 connecting the hydraulic pump 280 and the other end side of the cylinder tube 270.

[0044] In this type of cylinder, the volume (maximum volume) on one end side and the volume (maximum volume) on the other end side within the cylinder tube 270 with the piston 271b as the boundary differ depending on the presence or absence of the rod 271a of the piston rod 271. Therefore, the maximum capacity of the hydraulic oil supplied to the other end side of the cylinder tube 270 without the rod 271a is larger than the maximum capacity of the hydraulic oil supplied to one end side of the cylinder tube 270 with the rod 271a. In order to eliminate this capacity imbalance, an hydraulic oil storage portion 283 for storing hydraulic oil to compensate for the capacity difference is provided on the first oil passage 281 connecting one end side of the cylinder tube 270 and the hydraulic pump 280. Although not particularly shown here, in the first oil passage 281 and the second oil passage 282, pressure regulating valves, safety valves (relief valves), etc. for achieving pressure balance and the like are also appropriately arranged.

[0045] Since the gear pump is adopted for the hydraulic pump 280 in the cylinder devices 21R and 21L according to this embodiment, by switching the forward and reverse rotations of the electric motor 26, the hydraulic oil on one end side and the hydraulic oil on the other end side within the cylinder tube 270 with the piston 271b as the boundary are caused to flow back and forth. Specifically, when the electric motor 26 is rotationally driven (hereinafter referred to as forward rotation drive) on one side around the output shaft, the hydraulic pump 280 sucks in the hydraulic oil on the second oil passage 282 side and discharges it to the first oil passage 281 side. When the electric motor 26 is rotationally driven (hereinafter referred to as reverse rotation drive) on the other side around the output shaft, the hydraulic pump 280 sucks in the hydraulic oil on the first oil passage 281 side and discharges it to the second oil passage 282 side. That is, when the electric motor 26 is forward rotation driven, the hydraulic cylinder 27 retracts by retracting the rod 271a, and when the electric motor 26 is reverse rotation driven, the hydraulic cylinder 27 extends by protruding the rod 271a.

[0046] As shown in FIG. 2, each of the pair of actuators 21R and 21L is symmetrically arranged with respect to the virtual reference plane VS, similar to the pair of lower links 20R and 20L. Each of the pair of actuators 21R and 21L is arranged so as to straddle the corresponding lower link 20R or 20L and the vehicle body 1, and both ends in one direction (expansion and contraction direction) are connected to the lower link 20R or 20L and the vehicle body 1.

[0047] In this embodiment, in each of the pair of actuators 21R and 21L, as shown in FIG. 3, the cylinder end CE of the hydraulic cylinder 27 is connected to the vehicle body 1, and the rod end RE is connected to the corresponding lower links 20R and 20L.

[0048] At least one of the lower links 20R and 20L and the actuators 21R and 21L (hydraulic cylinders 27 of the electro-hydraulic cylinders 21 R and 21L) is provided with a plurality of connection positions H1..., H2... that can be connected to at least one of the other lower links 20R and 20L and the actuators 21R and 21L (hydraulic cylinders 27 of the electro-hydraulic cylinders 21R and 21L). In this embodiment, as described above, a plurality of connection positions (pin insertion holes that are through holes) H1... are provided with respect to the straight portions 20d of the lower links 20R and 20L. However, in this embodiment, a plurality of connection positions (through holes) H2... are also provided with respect to the actuators 21R and 21L (hydraulic cylinders 27 of the electro-hydraulic cylinders 21R and 21L). That is, a plurality of connection positions H2... for connecting to each other are set for each of the lower links 20R and 20L and the actuators 21R and 21L.

[0049] In this embodiment, the hydraulic cylinder 27 includes a connection fitting 29 at the rod end RE. The connection fitting 29 is provided with a plurality of through holes H2... arranged at intervals in the extending direction (axial direction) of the piston rod 271 (rod 271a). With any one of the plurality of through holes H2... of the connection fitting 29 aligned with any one of the plurality of pin insertion holes (through holes) H1... of the lower links 20R and 20L, a pin (shaft) is inserted (fitted) into both through holes H1 and H2, thereby connecting the connection fitting 29 (electro-hydraulic cylinders 21R and 21L) and the lower links 20R and 20L.

[0050] In this way, a plurality of through holes H1, …, H2, … are formed in each of the lower links 20R, 20L (linear portions 20d) and the connecting fitting 29, so that the connection positions H1, H2 between the lower links 20R, 20L and the actuators 21R, 21L can be combined. As a result, the posture (angle around the axis for pivotally connecting the first end portion 20a) of each of the pair of lower links 20R, 20L can be changed. As described above, the connection mechanism 2 includes angle sensors S3, S3. The angle sensors S3, S3 are provided corresponding to the first end portions 20a (pivoting axes) that are the rotation centers of the pair of lower links 20R, 20L, respectively. Thereby, even if the posture (angle) of each of the pair of lower links 20R, 20L is changed, the current posture (angle) of each of the pair of lower links 20R, 20L can be recognized based on the detection results of the angle sensors S3, S3.

[0051] As shown in FIGS. 5 and 6, both end portions of the connection frame 24 in the second direction are supported by the second end portions 20b (hooking members 23R, 23L) of the pair of lower links 20R, 20L via spherical bearings 240. Specifically, the connection frame 24 includes a frame body 241 that extends in the second direction and straddles the pair of lower links 20R, 20L, and a pair of shaft portions 242, 242 connected to both end portions of the frame body 241, and the pair of shaft portions 242, 242 each extend in the second direction. Further, the connection frame 24 includes a hooking portion 25 capable of hooking the working device B. More specifically, the connection frame 24 includes a pair of lower hooking portions 25a, 25a that are arranged at intervals in the second direction as the hooking portion 25. Furthermore, the connection frame 24 includes an upper hooking portion 25b capable of locking the working device B between the pair of lower hooking portions 25a, 25a and above the pair of lower hooking portions 25a, 25a.

[0052] The frame body 241 is curved such that the approximate center in the second direction protrudes upward. An upper link connection portion 243 to which the tip end portion 22b of the upper link 22 is connected is provided at the central portion (top portion) of the frame body 241. The upper link connection portion 243 is a pair of brackets 243a, 243a protruding upward from the upper surface of the frame body 241, the pair of brackets 243a, 243a being arranged at intervals in the second direction, and an axially-shaped locking pin 243b extending in the second direction, the locking pin 243b having both ends connected to the pair of brackets 243a, 243a. The axial center of the locking pin 243b coincides with the central position of the frame body 241. Thereby, the connecting frame 24 is connected to the upper link 22 by the locking pin 243b being locked to the tip end portion of the upper link 22.

[0053] The lower locking portions 25a, 25a of the connecting frame 24 are provided at both end portions of the frame body 241 respectively. Thereby, the pair of lower locking portions 25a, 25a are arranged at intervals in the second direction, similar to the pair of locking members 23R, 23L attached to the second end portions 20b of the pair of lower links 20R, 20L. That is, the pair of lower locking portions 25a, 25a are arranged at intervals in the second direction and symmetrically arranged with respect to the virtual reference plane VS. Each of the pair of lower locking portions 25a, 25a is a recess opened rearward and has a lower notch portion 250a dug deeper downward toward the front side. The lower notch portion 250a is configured to be able to insert a shaft extending in the second direction and is formed such that the shaft can be locked by the shaft being positioned on the front side. Note that the connecting frame 24 has a retaining member 251a that can be retracted in and out within the lower notch portion 250a of the lower locking portion 25a and can lock a shaft positioned at the inner portion of the lower locking portion 25a.

[0054] The upper hanging portion 25b is a depression that opens upward and has an upper notch portion 250b dug downward on the lower side. In the present embodiment, a pair of brackets 243a, 243a of the upper link connecting portion 243 extend rearward from the frame body 241. The upper notch portion 250b is formed such that it is open upward and dug downward with respect to the portion extending rearward of the pair of brackets 243a, 243a. That is, the pair of brackets 243a, 243a of the upper link connecting portion 243 are also used as the upper hanging portion 25b. Therefore, the upper hanging portion 25b is disposed at the central portion of the vehicle body 1 in the second direction. That is, the upper hanging portion 25b is disposed at an intermediate position between the pair of lower hanging portions 25a, 25a located below in the second direction.

[0055] As shown in FIG. 7, each of the pair of shaft portions 242, 242 includes a shaft body 244 that protrudes outward from the side surfaces facing outward at both ends of the frame body 241, and a spherical bearing 240 attached to the shaft body 244. The spherical bearing 240 has an inner ring 240a into which the shaft body 244 is inserted and an outer ring 240b that is externally fitted to the inner ring 240a. The outer peripheral surface of the inner ring 240a and the outer peripheral surface of the outer ring 240b are formed as spherical surfaces with the centers coinciding. Thereby, the shaft portions 242, 242 (inner ring 240a) and the outer ring 240b are relatively rotatable about the center (point) of the spherical surface as the rotation center with respect to the outer ring 240b.

[0056] In this embodiment, the shaft portions 242, 242 are latched to the latching members 23R, 23L of the corresponding lower links 20R, 20L. That is, they are latched in a state where the outer ring 240b of the shaft portions 242, 242 is in contact with the latching members 23R, 23L. In this state, the shaft body 244 can rotate about the center (point) of the spherical surface together with the inner ring 240a as the rotation center. In this embodiment, a spherical bearing 240 including the outer ring 240b is adopted, but it may be an annular bearing (for example, a grease-free bearing) into which the shaft body 244 is inserted and having an outer peripheral surface formed in a spherical shape (spherical bearing 240). In this case, since the outer peripheral surface on the spherical surface of the bearing contacts and is supported (latched) by the latching members 23R, 23L, the shaft body 244 (bearing) rotates on the latching members 23R, 23L about the center of the spherical surface as the rotation center. Further, if the shaft body 244 is rotatably inserted into the bearing, the shaft body 244 can also rotate about its own axis.

[0057] As shown in FIG. 8, the control device 4 includes an arithmetic control unit 40, a storage unit 41 that stores information used for the processing of the arithmetic control unit 40, and an input unit 42 electrically connected to the arithmetic control unit 40, which inputs an electric signal as input information from an external electric device to the arithmetic control unit 40, and an output unit 43 electrically connected to the arithmetic control unit 40, which outputs an instruction signal (electric signal) as output information from the arithmetic control unit 40 to an external electric device.

[0058] The arithmetic control unit 40 is a CPU (MPU) and includes an arithmetic unit 400 and a control unit 401. In the control device 4 according to this embodiment, the storage unit 41 includes a first storage unit 410 that temporarily or short-term stores information used for the processing by the arithmetic control unit 40 (arithmetic unit 400 and control unit 401), and a second storage unit 411 that stores information used for the processing by the arithmetic control unit 40 (arithmetic unit 400 and control unit 401) in a long-term manner. The first storage unit 410 is a so-called memory, and the second storage unit 411 is a storage device such as a hard disk or an SSD (Solid State Drive).

[0059] The input unit 42 and the output unit 43 are so-called interfaces. An electric device that outputs an electric signal as information is connected to the input unit 42. On the other hand, an electric device that receives an electric signal as information is connected to the output unit 43.

[0060] Specifically, the input unit 42 is connected to the first operating device 12, the second operating device 14, the attitude detection device 5 that detects the inclination (attitude) of the vehicle body 1 in the second direction, the angle sensors S3, S3, the receiver 16 that receives a radio signal from the transmitter 96 to be described later, and the like. On the other hand, the output unit 43 is connected to the electro-hydraulic cylinders 21R, 21L (electric motor 26) of the coupling mechanism 2, the power line EL1 for supplying power to the working device B, and the like. In the present embodiment, since the display device 13 is a touch panel type monitor, it is connected to the input unit 42 and the output unit 43 to transmit and receive information to and from the control device 4 (arithmetic control unit 40). Although the arrangement of the receiver 16 has not been mentioned, the receiver 16 (strictly speaking, the antenna of the receiver 16) is arranged at a place where communication with the transmitter 96 is not obstructed (for example, on the roof of the driver's seat protection mechanism (cab) 11) (see FIGS. 1 and 2). Further, in FIG. 8, although the electric motor 26 and the power line EL1 are directly connected to the output unit 43, strictly speaking, a relay (relay for electro-hydraulic cylinder) that opens and closes the power output system (circuit connecting the battery and the electric motor 26) that supplies power to the electro-hydraulic cylinders 21R, 21L (electric motor 26), and a relay (circuit opening and closing relay) that opens and closes the power output system (external output circuit) for supplying power to the working device B are connected.

[0061] The work vehicle A according to the present embodiment has the above configuration, and when the working device B connected to the coupling mechanism 2 is a tillage tractor that tills the soil, it has an automatic tillage depth function of maintaining the tillage depth of the soil at a preset depth. Further, the work vehicle A has an attitude maintenance function for maintaining the attitude of the working device B in an appropriate state (horizontal attitude in the second direction) when operating the working device B while driving the work vehicle A.

[0062] Accordingly, before performing the work, when the operator uses a tillage tractor as the work device B, the operator determines the necessity of the automatic tillage depth function by operating the second operating device 14 or by operating the touch panel type monitor (display device) 13. Further, when the operator performs work with the first work device B or other work devices B, the operator determines the necessity of the posture maintaining function by operating the second operating device 14 or by operating the touch panel (display device 13) as needed.

[0063] When the control device 4 receives a signal indicating that the automatic tillage depth function is to be activated effectively, as shown in FIG. 9, the control device 4 moves the rotary working body 6 (rotary 6) up and down according to the state of the penetration (depth from the ground surface GL) of the rotary 6 into the soil, and makes the state of the penetration (depth from the ground surface GL) of the rotary 6 into the soil constant. Specifically, the control device 4 grasps the current tillage depth state based on the information regarding the tillage depth by the tillage tractor. In the present embodiment, the work vehicle A receives, by the receiver 16, information regarding the detection result (tillage depth state) of the detection sensor 95 transmitted from the transmitter 96 (the transmitter 96 paired with the receiver 16 of the work vehicle A) provided in the work device B, and grasps the current tillage depth state based on the received detection result of the detection sensor 95. Then, the control device 4 calculates the difference between the grasped current tillage depth state and the preset tillage depth of the soil.

[0064] Furthermore, the control device 4 raises and lowers the working device B so as to eliminate the difference from the preset tilling depth of the soil. That is, the control device 4 drives the electric motors 26 of the pair of actuators 21R and 21L so as to raise and lower the pair of lower links 20R and 20L in synchronization according to the difference (height difference) from the preset tilling depth of the soil. That is, the control device 4 drives the electric motors 26 of the pair of actuators 21R and 21L in synchronization. As a result, as shown in FIG. 10, the pair of actuators 21R and 21L expand and contract in synchronization, and the pair of lower links 20R and 20L also move up and down in synchronization. At this time, the control device 4 raises and lowers the pair of lower links 20R and 20L by an amount of elevation corresponding to the detection result (tilt angle with respect to the horizontal) of the attitude detection device 5. That is, the control device 4 drives the electric motors 26 and 26 of the actuators 21R and 21L until the detection results (change angle amounts) by the angle sensors S3 and S3 reach the required state (angle). As a result, the working device B moves while maintaining the relative positional relationship (height relationship) between the rotary 6 and the ground surface GL of the field or the like. That is, the state of the rotary 6 entering the soil (depth from the ground surface GL) becomes constant, and even when performing tilling work while the work vehicle A is running, tilling can be performed in a preset tilling depth state with respect to the ground surface GL as a reference.

[0065] When the control device 4 has received a signal indicating that the attitude maintenance function is to be activated effectively, when the running of the work vehicle A is started, it recognizes the attitude (tilt angle in the second direction) of the vehicle body 1 based on the detection result from the attitude detection device 5.

[0066] In the present embodiment, the attitude detection device 5 detects changes in the vertical position at two locations in the second direction of the vehicle body 1. For example, as shown in FIG. 2, the attitude detection device 5 includes sensors S1 and S2 arranged at two locations in the second direction of the vehicle body 1 (two locations symmetric with respect to the virtual reference plane VS), and each of the sensors S1 and S2 measures the height change at each of the two locations in the second direction of the vehicle body 1.

[0067] For the sensors S1 and S2 arranged at two positions in the second direction of the vehicle body 1, for example, an altitude sensor, a barometric pressure sensor, or the like can be adopted. Along with this, the control device 4 calculates the angle of the vehicle body 1 in the second direction based on the height at two positions in the second direction, and calculates the difference between the attitude of the vehicle body 1 (the tilt angle of the vehicle body 1 in the second direction) and the horizontal. As described above, if the attitude detection device 5 includes a gyro sensor, in addition to the tilt (angle) of the vehicle body 1 in the front-rear direction, the tilt (angle) of the vehicle body 1 in the second direction can also be detected, and the control device 4 can recognize the state (tilt in the second direction) of the vehicle body 1 based on the detection result of the gyro sensor (attitude detection device 5).

[0068] Further, the control device 4 recognizes the amount of change in the vertical direction at each of the two positions in the second direction of the vehicle body 1 by the attitude detection device 5. Thereby, the control device 4 can determine how much the attitude change (tilt) of the vehicle body 1 has a floating and sinking at both the left and right sides in the second direction of the vehicle body 1, whether it has tilted around the front-rear center line CL, how much one side on the left or right in the second direction of the vehicle body 1 has sunk and tilted, and how much one side on the left or right in the second direction of the vehicle body 1 has risen and tilted.

[0069] Then, the control device 4 raises and lowers the pair of lower links 20R and 20L of the coupling mechanism 2 based on the above determination result. That is, the control device 4 drives the electric motor 26 of the pair of actuators 21R and 21L (electric hydraulic cylinders 21R and 21L) based on the determination result, and expands and contracts the hydraulic cylinders 27 of the pair of actuators 21R and 21L respectively.

[0070] In the present embodiment, since there are a plurality of combinations of the connection positions H1 and H2 between the actuator and the lower links 20R and 20L, the angles (attitudes) of the lower links 20R and 20L are different depending on the combination of the connection positions H1 and H2. When the angles of the lower links 20R and 20L are different in this way, the height of the connection position of the working device B is also different, and the reference attitude (angle) of the lower links 20R and 20L serving as the reference for the raising and lowering of the lower links 20R and 20L also changes. The reference attitude (angle) of the reference lower links 20R and 20L also changes.

[0071] Accordingly, the control device 4 recognizes the angles (postures) of the lower links 20R and 20L from the detection results of the angle sensors S3 and S3. Also, the amount of elevation and depression of the lower links 20R and 20L is recognized based on the detection results (rotation angles) of the angle sensors S3 and S3.

[0072] Then, as described above, when the vehicle body 1 tilts in the second direction, if the posture of the working device B behind the vehicle body 1 follows and tilts with the vehicle body 1, the relative arrangement (posture) with respect to the ground changes. Therefore, the control device 4 independently drives the electric motors 26 of the pair of actuators 21R and 21L.

[0073] Specifically, when the control device 4 determines that the change (tilt) in the posture of the vehicle body 1 has a certain amount of buoyancy and subsidence on both the left and right sides in the second direction of the vehicle body 1 and tilts about the front-rear center line CL, the control device 4 drives the pair of actuators 21R and 21L in opposite operations according to the amount of left and right buoyancy and subsidence. That is, the control device 4 drives the electric motor 26 of one of the actuators 21R in the forward rotation while driving the electric motor 26 of the other actuator 21L in the reverse rotation. Accordingly, as shown in FIGS. 11 and 12, one of the lower links 20R and 20L rises and one of the lower links 20R and 20L descends. Thereby, the working device B rotates on both the left and right sides about the front-rear center line CL (second direction) as the center (reference) and maintains a horizontal posture.

[0074] When the control device 4 determines that either the left or right side in the second direction of the vehicle body 1 has sunk and tilted, the control device 4 drives one of the actuators 21R according to the amount of subsidence. That is, the control device 4 drives the electric motor 26 of one of the actuators 21R in the forward rotation. Accordingly, as shown in FIGS. 13 and 14, one of the lower links 20R and 20L rises. That is, the working device B raises either the left or right side (the side where there is a risk of subsidence) hooked on one of the lower links 20R and 20L with the second end portion 20b of one of the lower links 20R and 20L as the fulcrum and maintains a horizontal posture.

[0075] Further, when the control device 4 determines that either the left or right side in the second direction of the vehicle body 1 has lifted and tilted to a certain extent, it drives either one of the actuators 21R according to the amount of lift. That is, the control device 4 reversely drives the electric motor 26 of either one of the actuators 21R. Accordingly, as shown in FIGS. 15 and 16, either one of the lower links 20R, 20L descends. That is, the working device B lowers either the left or right side (the side that may lift) hooked to either one of the lower links 20R, 20L with the second end 20b of either one of the lower links 20R, 20L as a fulcrum, and maintains a horizontal posture.

[0076] In this way, by independently driving the pair of left and right actuators 21R, 21L, not only can the posture of the working device B be corrected according to the tilt of the vehicle body 1, but also the correction corresponding to the cause of the tilt of the vehicle body 1 is achieved. Therefore, the working device B is restored to an appropriate posture based on the situation of the vehicle body 1.

[0077] Note that, as described above, when the pair of lower links 20R, 20L are independently lifted and lowered, torsion occurs in the connection frame 24 supported (hooked) by the pair of lower links 20R, 20L. However, in this embodiment, since the shaft portions 601, 601 of the connection frame 24 are provided with spherical bearings 240, the force (stress) due to torsion accompanying the correction of the posture of the connection frame 24 (frame body 241) does not act significantly on the shaft portions 601, 601 (particularly, the base of the shaft body 244).

[0078] Next, the working device B connected to the work vehicle A will be described. Note that, when explaining the working device B for the sake of convenience, in line with the description of the work vehicle A, when the work vehicle A moves straight ahead (forward or backward), the direction in which the working device B is connected to the work vehicle A and follows (the direction in which the working device B moves straight) is defined as the first direction, and the direction orthogonal to the direction in which the working device B moves straight and the vertical direction is defined as the second direction. Also, the vertical direction is defined as the third direction.

[0079] The working device B comes in various types. One of them is a rotary working body 6 that rotates around an axis extending in the second direction of the vehicle body 1 of the working vehicle A, and the working device B includes a rotary working body 6 that exhibits a predetermined function by rotating during operation. Even in this type, there are those in which the rotary working body 6 rotates passively and those that are rotationally driven upon receiving drive.

[0080] Here, first, a working device (hereinafter, referred to as the first working device for convenience) B in which a rotary 6 as a rotary working body is rotationally driven will be described.

[0081] The first working device B is a so-called rotary tiller and is not driven by the working vehicle A but drives the rotary 6 itself. That is, as shown in FIG. 1, the first working device B includes a prime mover 7a. As a result, the first working device B is driven without being affected by the load, energy loss, etc. of the internal combustion engine (engine), which is the drive source of the working vehicle A. Also, since the first working device B itself includes the prime mover 7a, the load applied to the working vehicle A is reduced.

[0082] The first working device B is an electric type that operates by receiving power supply from the working vehicle A. That is, the prime mover 7a is an electric motor. The prime mover 7a is driven by receiving power supply from the working vehicle A. In the conventional first working device B, in a state of being connected to the coupling mechanism 2, it was mechanically connected to the output shaft of the PTO mechanism of the working vehicle A and received the output of the engine, which is the prime mover (drive source) of the working vehicle A, via the PTO mechanism. However, the first working device B according to the present embodiment is only electrically connected to the power storage element (battery) of the working vehicle A without being connected to the working vehicle A for power transmission.

[0083] More specifically described, as shown in FIGS. 3 and 17, the first working device B includes a frame structure 8 including a connecting portion 80 connectable to a work vehicle A which is a travelable vehicle, and a rotary 6 which is a rotary working body pivotally supported by the frame structure 8, the rotary 6 being rotatable about an axis extending in the second direction, and a prime mover 7a for rotationally driving the rotary 6. The prime mover 7a has an output shaft 70a, and the output of the prime mover 7a (the rotational force of the output shaft 70a) is transmitted directly or indirectly to the rotary 6. In the present embodiment, the first working device B includes a drive transmission mechanism 7b for transmitting the output of the prime mover 7a to the rotary 6. That is, in the first working device B, the output of the prime mover 7a is indirectly transmitted to the rotary 6 via the drive transmission mechanism 7b. Further, the first working device B includes a work body cover 9 covering the rotary 6 (see FIG. 3).

[0084] As shown in FIG. 17, the frame structure 8 includes, in addition to the connecting portion 80, a support frame 81 extending in the second direction, and a pair of support portions 82, 83 extending downward from both end portions of the support frame 81.

[0085] The connecting portion 80 includes a pair of lower connecting portions 80a, 80a corresponding to the latching members 23R, 23L of a pair of lower links 20R, 20L on the work vehicle A side or the pair of lower latching portions 25a, 25a of the connecting frame 24. Further, in the present embodiment, the connecting portion 80 includes an upper connecting portion 80b corresponding to the tip portion 22b of the upper link 22 or the upper latching portion 25b of the connecting frame 24.

[0086] The pair of lower connecting portions 80a, 80a are arranged at intervals in the second direction. Specifically, each of the pair of lower connecting portions 80a, 80a includes a plate-shaped lower bracket 84 extending forward in the first direction from the support frame 81, and a lower connecting shaft 85 extending in the second direction from a side surface (a surface facing the second direction) of the lower bracket 84 and a lower connecting shaft 85 extending in the second direction therefrom.

[0087] The lower bracket 84 has one end and the other end opposite to the one end in the first direction, and one end is connected to the support frame 81. The lower connecting shaft 85 is disposed on the other end side of the lower bracket 84. The lower connecting shafts 85 of the pair of lower connecting portions 80a, 80a are concentric or substantially concentric.

[0088] The pair of lower connecting portions 80a, 80a are at the central position in the axial direction (second direction) of the rotary 6 and are the center line CL (see FIG. 2) extending in the first direction. When the working vehicle A is connected, the pair of lower connecting portions 80a, 80a are symmetrically arranged with respect to a virtual plane VS that extends in the first direction and the third direction along the center line CL that coincides or substantially coincides with the extension line of the front-rear center line CL of the vehicle body 1 as viewed from the third direction. Note that the center line CL (the center line CL of the working device B) extending in the first direction at the central position in the axial direction (second direction) of the rotary 6 extends in a direction different from the extension line of the front-rear center line CL of the vehicle body 1 when the working device B is not connected to the working vehicle A. Here, on the premise that the working device B is connected to the working vehicle A, for the sake of convenience, the center line CL passing through the center in the axial direction (second direction) of the rotary 6 is also referred to as the front-rear center line CL, and the virtual plane VS that extends in the first direction and the third direction with this as the reference is also referred to as the virtual reference plane.

[0089] The lower connecting shafts 85 of the pair of lower connecting portions 80a, 80a correspond to the arrangement of the latching members 23R, 23L of the pair of lower links 20R, 20L or the pair of lower latching portions 25a, 25a of the connecting frame 24. The lower connecting shaft 85 is set to an outer diameter that fits into the recess (notches 230R, 230L, lower notch 250a) of at least one of the latching members 23R, 23L and the latching portion 25. That is, the lower connecting shafts 85 of the respective lower connecting portions 80a, 80a are arranged so as to be latchable in the notches 230R, 230L of the latching members 23R, 23L of the corresponding lower links 20R, 20L or the recess (lower notch 250a) of the corresponding latching portion 25 (lower latching portions 25a, 25a) of the connecting frame 24. In the present embodiment, since the connecting mechanism 2 of the working vehicle A includes the connecting frame 24, each lower connecting shaft 85 is set to an outer diameter that fits into the lower notch 250a of the lower latching portion 25a.

[0090] The upper connecting part 80b is disposed between the pair of lower connecting parts 80a, 80a in the second direction. Specifically, the upper connecting part 80b is disposed corresponding to the intermediate position between the pair of lower connecting parts 80a, 80a in the second direction. That is, the upper connecting part 80b is disposed corresponding to the center in the axial direction (second direction) of the rotary 6.

[0091] More specifically, the upper connecting part 80b includes plate-shaped upper brackets 86, 86 extending from the support frame 81 in a direction orthogonal to the second direction (the front side corresponding to the forward direction of the work vehicle A), and an upper connecting shaft 87 extending in the second direction from the side surfaces (the surfaces facing the second direction) of the upper brackets 86, 86.

[0092] In the present embodiment, the upper connecting part 80b includes a pair of upper brackets 86, 86 arranged at intervals in the second direction. Each of the pair of upper brackets 86, 86 has one end and the other end on the side opposite to the one end, and one end of each is connected to the support frame 81.

[0093] The pair of upper brackets 86, 86 are arranged at an interval that allows the tip 22b of the upper link 22 to be interposed therebetween. The upper connecting shaft 87 is disposed on the other end side of the upper brackets 86, 86. The upper connecting shaft 87 is connected to the surface of the upper brackets 86, 86 facing the second direction and extends in the second direction. In the present embodiment, as a pair of upper brackets 86, 86 are provided, the upper connecting shaft 87 is disposed between the pair of upper brackets 86, 86 with its axis directed in the second direction. Accordingly, one end of the upper connecting shaft 87 is connected to the side surface of one of the upper brackets 86, 86 facing one side in the second direction, and the other end of the upper connecting shaft 87 is connected to the side surface of the other upper bracket 86, 86 facing the other side in the second direction.

[0094] The central position of the upper connecting shaft 87 in the axial direction is located on the virtual reference plane VS (the position corresponding to the front-rear center line CL when viewed from the third direction) (see FIG. 2). The upper connecting shaft 87 is located above the lower connecting portions 80a, 80a and is located directly above the lower connecting portions 80a, 80a or on the front side of the lower connecting portions 80a, 80a. In the present embodiment, the upper connecting shaft 87 is located on the front side of the lower connecting portions 80a, 80a.

[0095] The upper connecting shaft 87 is disposed corresponding to the notch 22c of the tip portion 22b of the upper link 22 or the upper notch 250b of the upper latching portion 25b of the connecting frame 24. Further, the upper connecting shaft 87 is set to an outer diameter that fits into the notch 22c of the tip portion 22b of the upper link 22 or the upper notch 250b of the upper latching portion 25b of the connecting frame 24. In the present embodiment, the upper connecting shaft 87 is set to an outer diameter that fits into the upper notch 250b of the connecting frame 24.

[0096] The support frame 81 is a rod-shaped body extending in the second direction. In the present embodiment, the support frame 81 is a hollow body (cylindrical body). The support frame 81 corresponds to the width of the rotary 6 in the second direction (strictly speaking, the length in the axial direction of the main shaft portion 600 described later).

[0097] The pair of support portions 82, 83 are connected to both ends of the support frame 81 and extend in a direction orthogonal to the axis of the support frame 81. In the present embodiment, each of the pair of support portions 82, 83 extends obliquely rearward and downward from the support frame 81 (see FIG. 3). That is, one of the pair of support portions 82, 83, the support portion 82, is connected to one end of the support frame 81 and extends obliquely rearward and downward, and the other support portion 83 of the pair of support portions 82, 83 is connected to the other end of the support frame 81 and extends obliquely rearward and downward. Each of the pair of support portions 82, 83 pivotally supports the rotary 6 at the lower end portion.

[0098] Specifically, each of the pair of support portions 82 and 83 has an upper end portion and a lower end portion. The upper end portion side is connected to the support frame 81, and bearing units 820 and 830 for pivotally supporting the rotary member 6 are attached to the lower end portions. In the present embodiment, flange-type bearing units 820 and 830 are attached to the lower end portions of each of the pair of support portions 82 and 83.

[0099] In the present embodiment, one of the support portions 82 is formed in a plate shape. One of the support portions 82 extends longitudinally in one direction, with one end portion in the longitudinal direction being the upper end portion located on the upper side and the other end portion in the longitudinal direction being the lower end portion located on the lower side (diagonally downward). The upper end portion of one of the support portions 82 is connected to one end surface of the support frame 81. In the present embodiment, as the support frame 81 is formed in a cylindrical shape, the upper end portion of one of the support portions 82 is connected (coupled) to the support frame 81 in a state of closing one end opening of the support frame 81.

[0100] A through hole 821 for inserting the shaft portion 601 of the rotary member 6 penetrates in a second direction through the lower end portion of one of the support portions 82. Accordingly, a flange-type bearing unit 820, which is a bearing, is attached to the outer surface of the support portion 82 (the side surface in the second direction and facing outward). The flange-type bearing unit 820 is bolted to one of the support portions 82 and is detachable from one of the support portions 82. Note that a reinforcing member (such as a rib) may be appropriately provided on the support portion 82 to enhance rigidity.

[0101] The other support portion 83 also serves as a cover (case) that covers the drive transmission mechanism 7b. Specifically, the other support portion 83 includes a plate-shaped first member 831 connected to the other end of the support frame 81, a plate-shaped second member 832 disposed at an interval in a second direction with respect to the first member 831, and a third member 833 that closes the space between the peripheral edge of the first member 831 and the peripheral edge of the second member 832. The first member 831, the second member 832, and the third member 833 define an accommodation space for accommodating the drive transmission mechanism 7b.

[0102] The first member 831 has a longitudinal length in one direction, with an upper end portion where one end in the longitudinal direction is located on the upper side and a lower end portion where the other end in the longitudinal direction is located on the lower side (diagonally downward). The length of the first member 831 in one direction is set to be longer than the length of one of the support portions 82 in one direction. Accordingly, the first member 831 is arranged such that the upper end portion is located diagonally forward and upward from the support frame 81 and is connected to the support frame 81. Specifically, the first member 831 is integrally connected to the support frame 81 at the upper end side rather than the intermediate position in one direction such that the upper end portion extends diagonally forward and upward from the support frame 81. The first member 831 is connected (coupled) to the support frame 81 in a state where the opening (the other end opening) of the support frame 81 is closed, similar to one of the support portions 82.

[0103] A hole (hereinafter referred to as the first shaft insertion hole) 831a for inserting the output shaft 70a of the prime mover 7a penetrates through the upper end portion of the first member 831 in the second direction. On the other hand, a hole (referred to as the second shaft insertion hole) 831b for inserting the shaft portion 601 of the rotary member 6 penetrates through the lower end portion of the first member 831 in the second direction.

[0104] The through hole 821 of one of the support portions 82 and the second shaft insertion hole 831b are formed to be concentric and of the same size. In view of the attachment and detachment of the rotary member 6, at least one of the through hole 821 of one of the support portions 82 and the second shaft insertion hole 831b may be formed in a notch shape that is open in a direction orthogonal to the second direction. In this way, even without making at least one of the pair of support portions 82, 83 removable from the support frame 81, it becomes possible to remove the rotary member 6 from the support portions 82, 83 in a direction orthogonal to the axial direction. However, it goes without saying that even if at least one of the through hole 821 of one of the support portions 82 and the second shaft insertion hole 831b is formed in a notch shape, the shaft portions 601, 601 at both ends of the rotary member 6 are inserted concentrically.

[0105] As such, with the second shaft insertion hole 831b provided in the first member 831, a flange type bearing unit 830, which is a bearing, is attached to the outer surface of the first member 831 (the side surface in the second direction and the side surface facing outward). The flange type bearing unit 830 is bolt-fixed to the first member 831 and is detachable from the first member 831.

[0106] The second member 832 is formed in a plate shape. In the present embodiment, the second member 832 is thinner than the first member 831. The second member 832 is formed to have the same shape and the same size when viewed from the second direction. The second member 832 is arranged such that the peripheral edge of the second member 832 and the peripheral edge of the first member 831 coincide when viewed from the second direction. The third member 833 is formed by sheet metal working and is formed along the peripheral edge of the second member 832 and the peripheral edge of the first member 831. In the present embodiment, one end of the third member 833 in the second direction is connected to the peripheral edge of the second member 832. That is, the second member 832 and the third member 833 are integrally formed.

[0107] On the other hand, the other end of the third member 833 in the second direction is detachably fixed to the peripheral edge of the first member 831. Specifically, the other end of the third member 833 is bent inward so as to overlap the peripheral edge of the first member 831. Along with this, the other end of the third member 833 is detachably fixed to the first member 831 via a screw member. Note that a plurality of screw members are arranged at predetermined intervals in the outer peripheral direction of the first member 831 to connect the peripheral edge of the first member 831 and the other end of the third member 833 at a plurality of locations.

[0108] The rotary 6 is arranged below the support frame 81. As described above, since the frame structure 8 includes a pair of support portions 82, 83, both ends of the rotary 6 are supported by the pair of support portions 82, 8 3.

[0109] Accordingly, the rotary 6 has shaft portions 601, 601 centered on the axis at both ends. More specifically, the rotary 6 includes a rotary shaft 60 extending over the entire length in the second direction, and a plurality of tilling claws 61... that are detachably attached to the rotary shaft 60. In FIG. 17, only the tilling claws 61 disposed in the regions at both ends of the rotary shaft 60 among the plurality of tilling claws 61... are shown, and the illustration of the tilling claws 61 therebetween is omitted.

[0110] The rotary shaft 60 includes a main shaft portion 600 to which a plurality of tilling claws 61... are attached, and a pair of shaft portions 601, 601 that protrude outward in the second direction from both ends of the main shaft portion 600, and the shaft portions 601, 601 are concentric with the main shaft portion 600. In the present embodiment, the main shaft portion 600 is a hollow shaft formed in a cylindrical shape, and weight reduction is achieved.

[0111] The pair of shaft portions 601, 601 are set to have a smaller diameter than the main shaft portion 600. As the main shaft portion 600 is formed in a hollow (cylindrical) shape, a flange portion for closing the open end of the main shaft portion 600 is connected to one end of the shaft portions 601, 601. The flange portion is connected to the main shaft portion 600 by welding.

[0112] One of the pair of shaft portions 601, 601 is pivotally supported by one of the pair of support portions 82, 83 of the frame structure 8, and the other shaft portion 601, 601 is pivotally supported by the other support portion 83 of the pair of support portions 82, 83 of the frame structure 8. Also, the driving force of the prime mover 7a is transmitted to one of the shaft portions 601.

[0113] Each of the pair of shaft portions 601, 601 is rotatably supported by bearings (flange type bearing units) 820, 830 fixed to the pair of support portions 82, 83. Specifically, one shaft portion 601 passes through the through hole 821 of one support portion 82 and is rotatably supported by a bearing (flange type bearing unit) 820 fixed to one support portion 82. On the other hand, the other shaft portion 601 passes through the second shaft insertion hole 831b of the first member 831 of the other support portion 83 and is rotatably supported by a bearing (flange type bearing unit) 830 fixed to the first member 831 of the other support portion 83. In the present embodiment, the other shaft portion 601 is set to a length that passes through the bearing (flange type bearing unit) 830 and protrudes outward from the bearing (flange type bearing unit) 830 in order to attach the input sprocket 71b described later.

[0114] As described above, the prime mover 7a has an output shaft 70a. The prime mover 7a is arranged with the output shaft 70a parallel or substantially parallel to the axis of the rotary 6. That is, the prime mover 7a is arranged with the output shaft 70a parallel or substantially parallel to the shaft portion 601. In the present embodiment, the prime mover 7a is an electric motor. Accordingly, the first working device B includes a power line (cable) EL2 (see FIGS. 2 and 8) that supplies power to the prime mover (electric motor) 7a. The power line EL2 that supplies power to the prime mover 7a can be connected to the power line EL1 of the work vehicle A that is connected to the power output system (external output circuit) of the work vehicle A via a connector C. Thereby, the prime mover 7a is driven by receiving power supply from the work vehicle A via the power lines EL1 and EL2. As described above, in FIG. 8, since the illustration of the power output system (external output circuit) is omitted, the power line EL2 of the first working device B is connected to the power line EL1 connected to the output portion 43 of the control device 4. Strictly speaking, the power line EL1 of the work vehicle A has a portion connecting the control device 4 and a relay that opens and closes the power output system (external output circuit), and a portion connecting the power output system (external output circuit) opened and closed by the relay and the connector C. The power line EL2 of the first working device B is electrically connected to the power output system via the connector C.

[0115] The prime mover 7a is attached to the support frame 81 or one of the support portions 82. In the present embodiment, the prime mover 7a is attached to the support frame 81. The prime mover 7a is disposed at a position that projectively overlaps the rotary 6 when viewed from a direction orthogonal to the second direction. In the present embodiment, the prime mover 7a is disposed in contact with or close to the other support portion 83 (first member 831) which is a cover.

[0116] Specifically, the prime mover 7a is disposed on the support frame 81 with the output shaft 70a inserted through the first shaft insertion hole 831a of the first member 831 and is fixed to the support frame 81. Thus, the prime mover 7a is disposed at a position that projectively overlaps the rotary 6 when viewed from a direction orthogonal to the second direction of the work vehicle A and is disposed within the range of the frame structure 8. That is, the prime mover 7a is disposed without protruding outward from the frame structure 8 in the second direction.

[0117] The prime mover 7a is in contact with or close to the first member 831 that constitutes the other support portion 83 (cover) with a casing (a casing that houses a rotor or the like continuous with the output shaft 70a). Accordingly, the output shaft 70a of the prime mover 7a protrudes into the accommodation space that houses the drive transmission mechanism 7b from the first member 831.

[0118] In this embodiment, the drive transmission mechanism 7b includes an output sprocket 71a attached to the output shaft 70a of the prime mover 7a, an input sprocket 71b attached to the other shaft portion 601 of the rotary 6, and a chain 71c wound around the output sprocket 71a and the input sprocket 71b. Accordingly, the input sprocket 71b is attached to a portion of the other shaft portion 601 of the rotary 6 that protrudes from the bearing 830. Note that, instead of the above configuration, the drive transmission mechanism 7b may have a gear group including an output gear attached to the output shaft 70a and an input gear attached to the shaft portions 601, 601, the input gear being directly or indirectly meshed with the output gear. Here, when the distance between the output gear and the input gear is large (when the output gear and the input gear cannot be directly meshed), an intermediate gear is provided between the output gear and the input gear, so that the output of the prime mover 7a can be transmitted to the rotary 6. That is, when a gear group is adopted for the drive transmission mechanism 7b, the output (rotational force) of the output gear may be directly or indirectly transmitted to the input gear.

[0119] As described above, since the output shaft 70a of the prime mover 7a and the other shaft portion 601 of the rotary 6 are between the first member 831 and the second member 832 (protruding into the accommodation space for accommodating the drive transmission mechanism 7b), the drive transmission mechanism 7b is covered by the other support portion 83 (cover). Further, when the prime mover 7a is rotationally driven, the drive transmission mechanism 7b transmits the output of the prime mover 7a to the rotary 6 (shaft portions 601, 601) and rotates the rotary 6.

[0120] As described above, in the first working device B according to this embodiment, the prime mover 7a and the drive transmission mechanism 7b are arranged on the other end side in the axial direction of the rotary 6 with reference to the center in the second direction. Accordingly, the weight (load) of the prime mover 7a and the drive transmission mechanism 7b acts biased toward the other end side in the axial direction of the rotary 6.

[0121] In view of this point, the first working device B includes a skid 75 disposed below the drive transmission mechanism 7b. Accordingly, the first working device B according to the present embodiment includes a rotating disk body 76 disposed at a position ahead of the skid 75 when the work vehicle A is traveling.

[0122] The skid 75 is movable in contact with the ground. The skid 75 is directly or indirectly connected to the frame structure 8 and receives a load acting downward. More specifically, the skid 75 includes a support leg 750 fixed to the frame structure 8 and a skid body 751 connected to the lower end of the support leg 750.

[0123] In the present embodiment, as shown in FIG. 3, the skid 75 includes two (a pair) of support legs 750. Each of the pair of support legs 750, 750 extends in one direction and has one end and the other end in one direction. The pair of support legs 750 are arranged at intervals in a direction orthogonal to the one direction. In the present embodiment, the pair of support legs 750 are fixed to the other support portion 83 (cover), which is a part of the frame structure 8. More specifically, the pair of support legs 750 are arranged along the outer surface of the second member 832. A plurality of through holes arranged at intervals in one direction, that is, a plurality of through holes (not numbered) through which a male screw member can be inserted, are provided in each of the pair of support legs 750. Accordingly, the second member 832 is provided with screw holes into which male screw members inserted through the through holes of the pair of support legs 750 are screwed. That is, the second member 832 is provided with screw holes corresponding to the pair of support legs 750 (through holes). Thereby, when fixing the skid 75, by selecting the through hole through which the male screw member is inserted from among the plurality of through holes of each support leg 750, the height of the skid body 751 can be changed and then the skid body 751 can be fixed in place.

[0124] The skid body 751 is formed in a ridged shape so that it can move in contact with the ground surface of a farm field or the like. Specifically, the skid body 751 is formed in a plate shape, extends in the traveling direction (straight-ahead direction) of the work vehicle A, and is inclined upward toward the leading side in the traveling direction, at least on the leading side in the traveling direction. In the present embodiment, in consideration of the forward and backward movement of the work vehicle A, the skid body 751 is inclined upward toward the leading side in the traveling direction when the work vehicle A moves forward, and is also inclined upward toward the leading side in the traveling direction when the work vehicle A moves backward. That is, both ends in one direction of the skid body 751 are inclined upward. In the present embodiment, the lower ends of the pair of support legs 750 are connected to the upper surface of the skid body 751 so that the skid body 751 is positioned below the other support portion 83. Thereby, even if the first working device B tends to tilt toward one end side of the rotary 6 due to the weight of the drive transmission mechanism 7b being biased toward one end side of the rotary 6 when the prime mover 7a is driven, the skid 75 contacts the ground surface, preventing the tilting.

[0125] In the present embodiment, the rotary disk body 76 is disposed at a position ahead of the skid 75 when the work vehicle A moves forward. That is, the rotary disk body 76 is disposed in front of the skid 75 (on the side of the working device B). The rotary disk body 76 is rotatable around an inclined axis that rises upward toward the rear side of the work vehicle A and passes through the front-rear center line CL passing through the center in the second direction of the work vehicle A.

[0126] Specifically, it includes a support shaft portion 77a that rotatably supports the rotary disk body 76, and a support column portion 77b that supports the disk body (support shaft portion 77a) in a state where the relative height positions of the rotary disk body 76 and the skid 75 are made constant.

[0127] The center line (axis line) of the support shaft portion 77a is an inclined axis line that rises upward toward the front-rear center line CL passing through the center in the second direction of the work vehicle A and the rear side in the traveling direction of the work vehicle A. That is, the support shaft portion 77a is inclined so as to rise upward toward the front-rear center line CL passing through the center in the second direction of the work vehicle A and the rear side in the traveling direction of the work vehicle A, and the rotary disk body 76 is rotatably attached to the tip end portion. The support column portion 77b extends in the vertical direction. The lower end of the support column portion 77b is connected to the skid 75, and the upper end of the support column portion 77b is connected to the support shaft portion 77a. In the present embodiment, the support column portion 77b is formed in a rod shape. Accordingly, the support shaft portion 77a and the support column portion 77b are integrally formed. Thereby, when the working device B moves forward, as the rotary disk body 76 moves ahead of the skid 75, while being in contact with the ground, it rotates around the inclined axis line to break (soften) the surface layer of the soil. Thereby, the moving resistance when the subsequent skid 75 moves while being in contact with the ground with respect to the rotary disk body 76 is reduced, and smooth movement becomes possible.

[0128] Specifically, the place where the working device B performs work is often soil in which lumps of soil and stones are mixed rather than on snow, and even if the skid 75 is formed in a concave shape, when it comes into contact with a lump of soil or a stone, the moving resistance increases. However, as described above, since the rotary disk body 76 comes into contact with the surface layer of the soil ahead of the skid 75, not only does the soil on the surface layer of the soil become soft, but stones are also excluded (pushed back) from the range through which the skid 75 passes, and lumps of soil are crushed. Thereby, smooth progress of the skid 75 is ensured.

[0129] As shown in FIG. 3, the working body cover 9 is a main cover 90 that covers the upper part of the rotary 6, and includes the main cover 90 supported by the frame structure 8 (support frame 81) and a detection cover 91 that covers the rear side of the rotary 6.

[0130] Both the main cover 90 and the detection cover 91 are made of sheet metal. The main cover 90 and the detection cover 91 are arranged in the first direction, and the detection cover 91 is inclined downward as it goes backward in the first direction from the side of the main cover 90. Specifically, the detection cover 91 is connected to the main cover 90 via a hinge 92. That is, the front end portion of the detection cover 91 on the front side in the first direction is rotatably connected to the rear end portion of the main cover 90 on the rear side in the first direction around an axis extending in the second direction. Thereby, the detection cover 91 is configured to be swingable, and the rear end portion of the detection cover 91 on the rear side in the first direction is configured to move up and down. The rear end portion of the detection cover 91 contacts the ground surface of the soil during tillage work and serves to level the ground surface.

[0131] In the present embodiment, the first working device B includes a detection cover adjustment mechanism 93 for changing the posture of the detection cover 91. That is, the first working device B includes a detection cover adjustment mechanism 93 for changing the height of the rear end of the detection cover 91. The detection cover adjustment mechanism 93 maintains the detection cover 91 in a desired posture (inclination) in a swingable state. That is, the detection cover adjustment mechanism 93 maintains the rear end of the detection cover 91 at a desired position (height) while maintaining the detection cover 91 in a swingable state. Further, the first working device B includes a detection sensor 95 for grasping the height of the rear end of the detection cover 91 in order to realize an automatic tillage depth function in the work vehicle A. Further, in the present embodiment, the first working device B includes a transmitter 96 (transmitter) that transmits the detection result by the detection sensor 95 toward the receiver 16 of the work vehicle A.

[0132] The detection sensor 95 is an angle sensor that detects the inclination (angle) of the detection cover 91. The detection sensor 95 includes a rotating lever and detects the rotation angle by the rotation of the rotating lever. The detection sensor 95 is attached to the main cover 90. A connecting bar that is pivotally connected to the rotating lever so as to be rotatable around an axis extending in the second direction with respect to the detection cover 91 is rotatably connected around the axis extending in the second direction. Thereby, when the detection cover 91 rotates (swings) about the hinge 92, the rotating lever of the detection sensor 95 rotates, and the detection sensor 95 is configured to detect the rotation (posture) of the detection cover 91.

[0133] Accordingly, the control device 4 of the work vehicle A is configured to calculate the vertical movement (amount of movement) of the rear end portion of the detection cover 91 based on the detection result (angle information) by the detection sensor (angle sensor) 95. When the transmitter 96 receives power supply, it is paired with the receiver 16 of the work vehicle A. Accordingly, the first working device B includes a power line (cable) that supplies power to the detection sensor 95 and the transmitter 96. The power line is similar to the power line connected to the prime mover 7a (electric motor 26). It can be connector-connected to the power output system (external output circuit) of the work vehicle A.

[0134] Next, another mode of the working device connected to the work vehicle A (hereinafter, referred to as the second working device for convenience) will be described. In the following description, the components (identical components) or corresponding components that are common to the configuration of the first working device B shall be given the same name and the same reference numerals. Also, the definitions of directions and the like shall be the same as those of the first working device B. In the following description, components (identical components) or corresponding components that are common to the configuration of the first working device B shall be given the same name and the same reference numerals. Also, the definitions of directions and the like shall be the same as those of the first working device B.

[0135] As shown in FIGS. 18 and 19, the second working device B is a cage roller type tiller including a cage roller 6 as a rotatable working body rotatable around an axis extending in the second direction. The second working device B is a driven tilling device in which the cage roller 6 rotates passively when the work vehicle A travels in a state where the cage roller 6 is in contact with the ground surface (grounded state). Accordingly, unlike the first working device B, the second working device B does not include a prime mover 7a.

[0136] More specifically, the second working device B includes a frame structure 8 including a connecting portion 80 connectable to a work vehicle A which is a travelable vehicle, and a cage roller 6 which is a rotary working body pivotally supported by the frame structure 8 and is rotatable about an axis extending in the second direction of the work vehicle A. Further, the second working device B according to the present embodiment includes a tilling device 78 disposed at a position ahead of the cage roller 6 when the work vehicle A travels. The second working device B also includes a working body cover 9 covering the cage roller 6.

[0137] As shown in FIG. 19, the frame structure 8 includes, in addition to the connecting portion 80, a support frame 81 extending in the second direction, and a pair of support portions 82 and 83 extending downward from both end portions of the support frame 81.

[0138] The connecting portion 80 includes a pair of lower connecting portions 80a, 80a corresponding to the latching members 23R, 23L of a pair of lower links 20R, 20L on the work vehicle A side or a pair of lower latching portions 25a, 25a of the connecting frame 24 (in the figure, the latching members 23R, 23L of the pair of lower links 20R, 20L). In the present embodiment, the connecting portion 80 also includes an upper connecting portion 80b corresponding to the tip end portion of the upper link 22.

[0139] The pair of lower connecting portions 80a, 80a are arranged at intervals in the second direction. Specifically, each of the pair of lower connecting portions 80a, 80a includes a plate-shaped lower bracket 84 extending in a direction orthogonal to the second direction (the front side corresponding to the forward direction of the work vehicle A) from the support frame 81, and a lower connecting shaft 85 extending in the second direction from a side surface (the surface facing the second direction) of the lower bracket 84.

[0140] The lower bracket 84 has one end and the other end opposite to the one end, and one end is connected to the support frame 81. The lower connecting shaft 85 is disposed on the other end side of the lower bracket 84. The lower connecting shafts 85 of the pair of lower connecting portions 80a, 80a are concentric or substantially concentric.

[0141] The pair of lower connecting portions 80a, 80a are symmetrically arranged with respect to the virtual reference plane VS. The lower connecting axes 85 of the pair of lower connecting portions 80a, 80a correspond to the arrangement of the latching members 23R, 23L of the pair of lower links 20R, 20L or the pair of lower latching portions 25a, 25a of the connecting frame 24. The lower connecting axis 85 is set to an outer diameter that fits into the recess of at least one of the latching members 23R, 23L and the lower latching portions 25a, 25a. That is, the lower connecting axis 85 of each lower connecting portion 80a, 80a is arranged so as to be latchable in the recess (lower notch portion 250a) of the corresponding latching member 23R, 23L of the corresponding lower link 20R, 20L or the corresponding lower latching portion 25a, 25a of the connecting frame 24. In the present embodiment, the lower connecting axis 85 of each lower connecting portion 80a, 80a is configured to be latchable to the latching members 23R, 23L of the corresponding lower links 20R, 20L. Note that the lower connecting axis 85 includes a shaft body connected to the lower bracket 84 and a spherical bearing externally fitted to the shaft body, similar to the shaft portion 242 of the connecting frame 24.

[0142] The upper connecting portion 80b is arranged between the pair of lower connecting portions 80a, 80a in the second direction. Specifically, the upper connecting portion 80b is arranged corresponding to the intermediate position between the pair of lower connecting portions 80a, 80a in the second direction. That is, the upper connecting portion 80b is arranged corresponding to the center in the axial direction (second direction) of the cage roller 6.

[0143] More specifically, the upper connecting portion 80b includes plate-like upper brackets 86, 86 extending from the support frame 81 in a direction orthogonal to the second direction (the front side corresponding to the forward direction of the work vehicle A), and an upper connecting axis 87 extending in the second direction from the side surfaces (surfaces facing the second direction) of the upper brackets 86, 86.

[0144] In the present embodiment, the upper connecting portion 80b includes a pair of upper brackets 86, 86 arranged at intervals in the second direction. Each of the pair of upper brackets 86, 86 has one end and the other end on the opposite side of the one end, and one end of each is connected to the support frame 81.

[0145] A pair of upper brackets 86, 86 are arranged with an interval that allows the tip of the upper link 22 to be interposed therebetween. The upper connecting shaft 87 is arranged on the other end side of the upper brackets 86, 86. The upper connecting shaft 87 is connected to the surface of the upper brackets 86, 86 facing the second direction and extends in the second direction. In the present embodiment, as a pair of upper brackets 86, 86 are provided, the upper connecting shaft 87 is arranged between the pair of upper brackets 86, 86 with its axis facing the second direction.

[0146] Accordingly, one end of the upper connecting shaft 87 is connected to the side surface of one upper bracket 86 facing one side in the second direction, and the other end of the upper connecting shaft 87 is connected to the side surface of the other upper bracket 86 facing the other side in the second direction. The central position of the upper connecting shaft 87 in the axial direction (second direction) coincides or substantially coincides with the front-rear center line CL (virtual reference plane VS) when viewed from the third direction. The upper connecting shaft 87 is located above the lower connecting portions 80a, 80a, and is directly above the lower connecting portions 80a, 80a or on the front side in the first direction with respect to the lower connecting portions 80a, 80a. In the present embodiment, the upper connecting shaft 87 is located on the front side in the first direction with respect to the lower connecting portions 80a, 80a.

[0147] The upper connecting shaft 87 is arranged corresponding to the notch 22c of the tip 22b of the upper link 22 or the upper notch 250b of the upper latching portion 25b of the connecting frame 24. Further, the upper connecting shaft 87 is set to an outer diameter that fits into the notch 22c of the tip 22b of the upper link 22 or the upper notch 250b of the upper latching portion 25b of the connecting frame 24. In the present embodiment, the upper connecting shaft 87 is set to an outer diameter that fits into the notch 22c of the tip 22b of the upper link 22.

[0148] The support frame 81 is a rod-shaped body extending in the second direction. In the present embodiment, the support frame 81 is a hollow body (cylindrical body). The support frame 81 corresponds to the width of the cage roller 6 (strictly speaking, the axial length of the main shaft portion 600 described later).

[0149] The pair of support portions 82 and 83 are connected to both ends of the support frame 81 and extend in a direction orthogonal to the axis of the support frame 81. In the present embodiment, each of the pair of support portions 82 and 83 extends obliquely rearward and downward from the support frame 81. That is, one support portion 82 of the pair of support portions 82 and 83 is connected to one end of the support frame 81 and extends obliquely rearward and downward, and the other support portion 83 of the pair of support portions 82 and 83 is connected to the other end of the support frame 81 and extends obliquely rearward and downward. Each of the pair of support portions 82 and 83 pivotally supports the cage roller 6 at the lower end portion.

[0150] Specifically, each of the pair of support portions 82 and 83 has an upper end portion and a lower end portion. The upper end portion side is connected to the support frame 81, and bearings 820 and 830 for pivotally supporting the cage roller 6 are attached to the lower end portion. In the present embodiment, flange-type bearing units 820 and 830 are attached to the lower end portions of the support portions 82 and 83.

[0151] In the present embodiment, the pair of support portions 82 and 83 are formed in a plate shape. Each of the pair of support portions 82 and 83 has a longitudinal length in one direction. One end portion in the longitudinal direction is an upper end portion located on the upper side, and the other end portion in the longitudinal direction is a lower end portion located on the lower side (obliquely downward). The upper end portion of one support portion 82 is connected to one end surface of the support frame 81. The upper end portion of the other support portion 83 is connected to the other end surface of the support frame 81. In the present embodiment, as the support frame 81 is formed in a cylindrical shape, the upper end portions of the pair of support portions 82 and 83 are connected (coupled) to the support frame 81 in a state where the opening of the support frame 81 is closed.

[0152] At the lower end of each of the pair of support portions 82 and 83, through holes 821 and 831b for inserting the shaft portions 601 and 601 of the cage rollers 6 are formed in the second direction. Accordingly, flange type bearing units 820 and 830 are attached to the outer surfaces (the side surfaces in the second direction and facing outward) of the pair of support portions 82 and 83. The flange type bearing units 820 and 830 are bolted to the support portions 82 and 83 and are detachable from the support portions 82 and 83. As in this embodiment, when the support portions 82 and 83 are in the form of plates, reinforcing members (ribs or the like) for reinforcing (increasing the rigidity of) the support portions 82 and 83 may be appropriately provided.

[0153] The cage roller 6 is disposed below the support frame 81. In this embodiment, the cage roller 6 is disposed obliquely rearward and downward of the support frame 81. As described above, since the frame structure 8 includes the pair of support portions 82 and 83, both ends of the cage roller 6 are supported by the pair of support portions 82 and 83.

[0154] The cage roller 6 has shaft portions 601 and 601 centered on the axis at one end. More specifically, the cage roller 6 has a roller body 605 and a pair of shaft portions 601 and 601.

[0155] The roller body 605 is a plurality of horizontal bars 605a... arranged at intervals in the circumferential direction around the rotation center (axis extending in the second direction), each of which is a plurality of horizontal bars 605a... extending in the second direction and a pair of support plates 605b and 605b connected to both ends of the plurality of horizontal bars 605a..., and a pair of support plates 605b and 605b that support both ends of each of the plurality of horizontal bars 605a.... The roller body 605 includes reinforcing members 605c... for reinforcing the plurality of horizontal bars 605a....

[0156] Each of the multiple horizontal bars 605a is a solid or hollow bar. In this embodiment, a solid bar is used for each of the multiple horizontal bars 605a. As shown in Fig. 18, the multiple horizontal bars 605a have their centers (center lines) positioned on a virtual circle (circle viewed from the second direction) VC centered on the rotation center of the cage roller 6. In this embodiment, the multiple horizontal bars 605a are disposed at equal intervals in the circumferential direction around the rotation center (the circumferential direction of the virtual circle).

[0157] Each of the pair of support plates 605b, 605b is formed in a circular shape. Each of the pair of support plates 605b, 605b is set to a size that allows it to face the end faces of the multiple horizontal bars 605a... with its own center aligned with the center of the virtual circle VC that is the reference for the arrangement of the multiple horizontal bars 605a.... In this embodiment, each of the pair of support plates 605b, 605b has multiple cutouts formed on the outer circumferential end. The multiple cutouts are located between the horizontal bars 605a... adjacent to each other in the circumferential direction. In this embodiment, each of the multiple cutouts has an arc shape when viewed from the second direction.

[0158] The pair of shaft portions 601, 601 are connected to the outer surfaces (surfaces facing outward in the second direction) of the pair of support plates 605b, 605b and protrude outward from the outer surfaces. Each of the pair of shaft portions 601, 601 has an axis extending in the second direction and is arranged concentrically with each other. Furthermore, each axis of the pair of shaft portions 601, 601 coincides with the center of the support plates 605b, 605b (the center of the imaginary circle VC).

[0159] The tilling device 78 has a plurality of tilling members 780 arranged in the second direction. In this embodiment, a soiler, more specifically, a soiler with wings, is used for each of the plurality of tilling members 780. The soiler 780 is formed in a plate shape. The soiler 780 is disposed with the plate thickness direction being the up-down direction. On this premise, the width of the soiler 780 in a second direction perpendicular to the traveling direction (first direction) and the up-down direction tapers toward the front in the traveling direction.

[0160] The tilling device 78 includes a support member 781 that supports a tilling member 780, and the support member 781 is directly or indirectly attached to the frame structure 8. The support member 781 extends in the vertical direction, and the tilling member (subsoiler) 780 is attached to the lower end thereof. In the present embodiment, the support member 781 is formed in a prismatic shape. As the tilling device 78 has a plurality of tilling members 780, it also has a plurality of support members 781 corresponding to the tilling members 780. That is, the support member 781 is provided for each tilling member 780. The support member 781 is attached to the frame structure 8 so as to be slidable in the vertical direction, enabling adjustment of the height position of the tilling member 780.

[0161] More specifically, the second working device B includes an attachment bar 782 that is connected and supported by the support frame 81 and is disposed on the front side of the support frame 81, and a fixing fitting 783 that fixes the tilling device 78 (tilling member 780) to the attachment bar 782.

[0162] The attachment bar 782 extends in the second direction. In the present embodiment, the attachment bar 782 is formed in a square tubular shape. The length of the attachment bar 782 in the second direction corresponds to the length of the support frame 81 (cage roller 6) in the second direction so that the plurality of tilling members 780 can be arranged in the second direction in front of the cage roller 6 (a position that precedes during travel).

[0163] The fixing fitting 783 is formed in a U-shape when viewed from the second direction. Specifically, the fixing fitting 783 includes a pair of first piece parts 783a, 783a that are spaced apart in the vertical direction and each extend in the first direction, and a second piece part 783b that connects one end of each of the pair of first piece parts 783a, 783a. The pair of first piece parts 783a, 783a and the second piece part 783b are formed in a plate shape. Accordingly, in the fixing fitting 783 according to the present embodiment, the pair of first piece parts 783a, 783a and the second piece part 783b are continuously and integrally formed by bending a metal plate into a U-shape.

[0164] The length of the pair of first blade portions 783a, 783a in the first direction is set to be the length extending forward from the mounting bar 782 with the mounting bar 782 interposed between the pair of first blade portions 783a, 783a. And each of the pair of first blade portions 783a, 783a has a hole 784 through which the support member 781 is inserted vertically. As described above, since the support member 781 is formed in a square tube shape, the holes 784 of the first blade portions 783a, 783a are square holes according to the cross-sectional shape of the support member 781.

[0165] A male screw member S that biases the mounting bar 782 interposed between the pair of first blade portions 783a, 783a forward is screwed into the second blade portion 783b. The fixing bracket 783 biases the male screw member S to urge the mounting bar 782, thereby pulling the pair of first blade portions 783a, 783a backward. Accordingly, the support member 781 inserted through the holes of the pair of first blade portions 783a, 783a is also pulled backward and pressed against the mounting bar 782. Thereby, the fixing bracket 783 fixes the support member 781 and the tilling member 780 connected to the support member 781 in a fixed position. Further, the fixing bracket 783 allows the vertical movement of the support member 781 by loosening the male screw member S to release the pressure contact of the support member 781 against the mounting bar 782.

[0166] Accordingly, the fixing fitting 783 enables height adjustment of the tilling member 780 connected to the support member 781. In the present embodiment, the fixing fitting 783 is provided corresponding to each of the plurality of tilling members 780. That is, the second working device B includes a plurality of fixing fittings 783. Along with this, the plurality of fixing fittings 783 are fitted into the mounting bar 782 in a state of being arranged side by side in the second direction. Thereby, the second working device B according to the present embodiment can individually fix and adjust the height of the tilling member 780. Note that the width of the fixing fitting 783 in the second direction may correspond to the length of the mounting bar 782 to form a single fixing fitting 783, and a plurality of holes (holes for inserting the support member 781) may be provided at intervals in the second direction in each of the pair of first piece portions 783a, 783a. In this way, the fixing and position adjustment of the plurality of support members 781 (tilling members 780) can be performed with a small number of man-hours. In this case, it goes without saying that it is preferable to arrange a plurality of male screw members S in the second direction in order to ensure the pulling force for the plurality of support members 781.

[0167] The working body cover 9 may have the same configuration as the working body cover 9 of the first working device B. However, in the present embodiment, it is a detection cover 91 that covers from above to the rear of the cage roller 6 and includes the detection cover 91 supported by the frame structure 8 (support frame 81). In the present embodiment, the working body cover 9 further includes an extension cover 94 that extends the detection cover 91.

[0168] The detection cover 91 and the extension cover 94 are both made of sheet metal. The detection cover 91 and the extension cover 94 are arranged in the first direction. The detection cover 91 is inclined downward as it goes backward from the position covering above the cage roller 6. Specifically, the detection cover 91 is connected to the frame structure 8 (support frame 81) via a hinge 92. That is, the front end portion of the detection cover 91 on the front side in the first direction is rotatably connected to the portion on the rear side in the first direction of the support frame 81 around an axis extending in the second direction. Thereby, the detection cover 91 is configured to be swingable, and the rear end portion of the detection cover 91 on the rear side in the first direction is configured to move up and down. In the present embodiment, the rear end portion of the extension cover 94 contacts the ground surface of the soil during tillage work and serves to level the ground surface.

[0169] In the present embodiment, the second working device B includes a detection cover adjustment mechanism 93 for changing the posture of the detection cover 91. That is, the second working device B includes a detection cover adjustment mechanism 93 for changing the height of the rear end of the detection cover 91. The detection cover adjustment mechanism 93 maintains the detection cover 91 in a desired posture (inclination) in a swingable state. That is, the detection cover adjustment mechanism 93 maintains the rear end of the detection cover 91 at a desired position (height) while maintaining the detection cover 91 in a swingable state. Further, the second working device B includes a detection sensor 95 for grasping the height of the rear end of the detection cover 91 in order to realize the automatic tillage depth function in the work vehicle A. Further, in the present embodiment, the second working device B includes a transmitter 96 (transmitter) that transmits the detection result by the detection sensor 95 toward the receiver 16 of the work vehicle A.

[0170] The detection sensor 95 is an angle sensor that detects the inclination (angle) of the detection cover 91. The detection sensor 95 includes a rotating lever and detects the rotation angle by the rotation of the rotating lever. The detection sensor 95 is attached to the frame structure 8 (support frame 81). A connecting bar that is pivotally connected to the rotating lever so as to be rotatable around an axis extending in the second direction with respect to the detection cover 91 is rotatably connected around the axis extending in the second direction. Thereby, when the detection sensor 95 rotates (swings) with the detection cover 91 rotating (oscillating) about the hinge 92, the rotating lever of the detection sensor 95 rotates, and the rotation (posture) of the detection cover 91 is detected.

[0171] Accordingly, the control device 4 of the work vehicle A is configured to calculate the vertical movement (movement amount) of the rear end portion of the detection cover 91 based on the detection result (angle information) by the detection sensor (angle sensor) 95. When the transmitter 96 receives power supply, it is paired with the receiver 16 of the work vehicle A. Accordingly, the second working device B includes a power line (cable) that supplies power to the detection sensor 95 and the transmitter 96. The power line is similar to the power line connected to the prime mover 7a (electric motor 26). It can be connected to the power output system (external output circuit) of the work vehicle A by a connector.

[0172] The detection sensor 95 is an angle sensor that detects the inclination (angle) of the detection cover 91. As described above, the control device 4 of the work vehicle A is configured to calculate the vertical movement (movement amount) of the rear end portion of the detection cover 91 based on the detection result (angle information) by the angle sensor. When the transmitter 96 receives power supply, it is paired with the receiver 16 of the work vehicle A. Accordingly, the second working device B includes a power line (cable) that supplies power to the detection sensor 95 and the transmitter 96. The power line is similar to the power line connected to the prime mover 7a (electric motor 26). It can be connected to the power output system (external output circuit) of the work vehicle A by a connector.

[0173] The second working device B is as described above. When performing tillage work, as the work vehicle A moves forward, the tilling member 780 (subsoiler) tills the soil in advance. The cage roller 6 further tills or cultivates the surface layer of the soil tilled by the tilling member 780 (subsoiler). In the present embodiment, since the extension cover 94 follows the cage roller 6, the extension cover 94 levels the soil surface uniformly. Also, the second working device B has a detection sensor 95, and since the detection result by the detection sensor 95 can be transmitted from the transmitter 96 to the work vehicle A, when the operator sets the automatic tillage depth function, the control device 4 of the work vehicle A operates the coupling mechanism 2 (lower links 20R, 20L) based on the detection result of the detection sensor 95 to raise and lower the second working device B. Thereby, good tillage can also be performed in the second working device B.

[0174] The above embodiment is as described above. The present invention (a preferred embodiment thereof) provides the work vehicle A described in the following items (items 1-1 to items 1-8). Incidentally, the above embodiment also provides the working device B described in the following items (items 2-1 to items 2-12).

[0175] (Item 1-1) A work vehicle A comprising a travelable vehicle body 1 and a coupling mechanism 2 attached to the vehicle body 1 for coupling and supporting a working device B. The coupling mechanism 2 includes a pair of lower links 20R, 20L each having a first end 20a rotatably coupled to the vehicle body 1 about an axis extending in the width direction (second direction) of the vehicle body 1 and a second end 20b opposite to the first end 20a, the pair of lower links 20R, 20L being spaced apart in the width direction (second direction) of the vehicle body 1, and the working device B being directly or indirectly coupled to the second end 20b; and a pair of actuators 21R, 21L arranged corresponding to each of the pair of lower links 20R, 20L, each actuator 21R, 21L rocking the corresponding lower link 20R, 20L about its axis. The pair of actuators 21R, 21L are each independently operable.

[0176] According to the work vehicle A of item 1-1, since the pair of actuators 21R and 21L can operate independently, the pair of lower links 20R and 20L can also rotate independently. That is, the pair of lower links 20R and 20L can rotate in the same direction in synchronization (the second end 20b moves up and down) or rotate in opposite directions to each other. Also, only one of the lower links 20R or 20L can be moved up and down. As a result, the work device B connected to the second ends 20b of the pair of lower links 20R and 20L assumes an appropriate posture according to the change in the posture of the vehicle body 1. Therefore, the work vehicle A can bring the posture of the work device B into an appropriate state according to the situation.

[0177] (Item 1-2) Each of the pair of actuators 21R and 21L is a cylinder device configured to be extendable and contractible in one direction and having an electric motor 26 for driving to extend and contract itself, and is arranged to straddle the corresponding lower links 20R and 20L and the vehicle body 1, and both ends in one direction are connected to the lower links 20R and 20L and the vehicle body 1. The work vehicle A described in item 1-1.

[0178] According to the work vehicle A of item 1-2, since each of the pair of actuators 21R and 21L is a cylinder device 21R and 21L configured to be extendable and contractible in one direction and having an electric motor 26 for driving to extend and contract itself, they can operate independently. That is, since the pair of actuators 21R and 21L (cylinder devices 21R and 21L) extend and contract by the drive of their own electric motors 26, one of the actuators 21R can extend and contract without being affected by the situation of the other actuator 21L. As a result, the pair of lower links 20R and 20L can move up and down independently without affecting each other (without mutual interference).

[0179] (Item 1-3) Each of the pair of actuators 21R and 21L is a electro-hydraulic cylinder including a hydraulic pump 280 that discharges hydraulic oil for its own expansion and contraction, and the hydraulic pump 280 is driven by an electric motor 26. The work vehicle A described in item 1-2.

[0180] According to the work vehicle A of item 1-3, since each of the pair of actuators 21R and 21L is an electro-hydraulic cylinder including a hydraulic pump 280 driven by an electric motor 26, sufficient propulsive force (pushing force and pulling force) during expansion and contraction can be ensured.

[0181] (Item 1-4) At least one of the lower links 20R and 20L and the actuators 21R and 21L is provided with a plurality of connection positions connectable to at least the other of the lower links 20R and 20L and the actuators 21R and 21L. The connection mechanism 2 includes angle sensors S3 and S3 that detect the rotation angle around the axis of each of the pair of lower links 20R and 20L. The work vehicle A described in item 1-2.

[0182] According to item 1-4, since at least one of the lower links 20R and 20L and the actuators 21R and 21L is provided with a plurality of connection positions connectable to at least the other of the lower links 20R and 20L and the actuators 21R and 21L, the posture (tilt angle) of the lower links 20R and 20L can be adjusted according to the situation by the combination of the connection positions. Furthermore, since the connection mechanism 2 includes angle sensors S3 and S3 that detect the rotation angle around the axis of each of the pair of lower links 20R and 20L, the situation (tilt angle) of the pair of lower links 20R and 20L can be grasped. Thereby, the reference position (posture) of the pair of lower links 20R and 20L and the required rotation amount (rotation angle) for each of the pair of lower links 20R and 20L can also be grasped. Therefore, the pair of lower links 20R and 20L can be rotated by a rotation amount and in a rotation direction according to the situation.

[0183] (Item 1-5) The connecting mechanism 2 is a connecting frame 24 that connects the second ends 20b of a pair of lower links 20R and 20L, and has a connecting frame 24 including a latching portion 25 capable of latching the working device B. Both ends of the connecting frame 24 are supported by the respective second ends 20b of the pair of lower links 20R and 20L via spherical bearings 240. The work vehicle A according to any one of Items 1-1 to 1-4.

[0184] According to the work vehicle A of Item 1-5, since the connecting mechanism 2 is a connecting frame 24 that connects the second ends 20b of a pair of lower links 20R and 20L and has a connecting frame 24 including a latching portion 25 capable of latching the working device B, by latching the working device B to the latching portion 25, it can be connected to the second ends 20b of the pair of lower links 20R and 20L via the connecting frame 24. Furthermore, since both ends of the connecting frame 24 are supported by the respective second ends 20b of the pair of lower links 20R and 20L via spherical bearings 240, even if the pair of lower links 20R and 20L rotate relatively in opposite directions, no torsional action occurs on the connecting frame 24 and the working device B, and unnecessary force (stress) is prevented from acting. That is, since the spherical bearing 240 allows rotation regardless of direction around the center point of the sphere, when a height difference occurs between the second ends 20b of the pair of lower links 20R and 20L, it allows the posture of the connecting frame 24 supported by the second ends 20b of the lower links 20R and 20L to change. Therefore, it is prevented that a large torsional stress acts on the end of the connecting frame 24 supported by the second ends 20b of the lower links 20R and 20L. Also, since excessive friction does not occur between the second ends 20b of the lower links 20R and 20L and the ends of the connecting frame 24, wear of both is suppressed.

[0185] (Item 1-6) The connecting mechanism 2 is a pair of latching members 23R and 23L capable of latching the working device B, and has a pair of latching members 23R and 23L connected to the respective second ends 20b of the pair of lower links 20R and 20L. The work vehicle A according to any one of Items 1-1 to 1-5.

[0186] According to the work vehicle A of Items 1-6, since it has a pair of latching members 23R and 23L capable of latching the work device B, and the pair of latching members 23R and 23L are connected to the respective second ends 20b of the pair of lower links 20R and 20L, the connection of the work device B can be easily and surely performed.

[0187] (Item 1-7) The connection mechanism 2 has an upper link 22 disposed above the pair of lower links 20R and 20L. The upper link 22 includes a base end 22a rotatably connected to the vehicle body 1 about an axis extending in the width direction (second direction), and a tip end 22b on the side opposite to the base end 22a. The tip end 22b is connected to the connection frame 24 rotatably about an axis extending in the width direction (second direction). The work vehicle A according to Item 1-5.

[0188] According to the work vehicle A of Items 1-7, since it has an upper link 22 disposed above the pair of lower links 20R and 20L, the upper link 22 includes a base end 22a rotatably connected to the vehicle body 1 about an axis extending in the width direction (second direction), and a tip end 22b on the side opposite to the base end. The tip end 22b is connected to the connection frame 24 rotatably about an axis extending in the width direction (second direction). The connection frame 24 is supported at three (three locations) of the pair of lower links 20R and 20L and the upper link 22. Thereby, since the positioning (posture determination) of the connection frame 24 is ensured, the work device B is stably connected and supported.

[0189] (Item 1-8) The connection mechanism 2 has an upper link 22 disposed above the pair of lower links 20R and 20L. The upper link 22 has a base end connected to the vehicle body 1 and a tip end on the side opposite to the base end, and the tip end of the upper link 22 is capable of latching the work device B. The work vehicle A according to Item 1-6.

[0190] According to the work vehicle A of items 1 - 8, it has an upper link 22 disposed above a pair of lower links 20R and 20L. The upper link 22 has a base end portion rotatably connected to the vehicle body 1 about an axis extending in the width direction (second direction), and a tip end portion on the opposite side of the base end portion. Since the tip end portion of the upper link 22 can latch the work device B, the work device B is supported at three (three locations) of the pair of lower links 20R and 20L and the upper link 22. That is, for the positioning (posture determination) of the work device B to be ensured, the work device B is stably connected and supported.

[0191] (Item 2 - 1) A frame structure 8 including a connecting portion 80 connectable to a traveling vehicle, and a rotary work body 6 pivotally supported by the frame structure 8, the rotary work body 6 being rotatable about an axis extending in the width direction (second direction) of the traveling vehicle, and a prime mover 7a for rotationally driving the rotary work body 6, and an output of the prime mover 7a is transmitted directly or indirectly to the rotary work body 6, the work device B.

[0192] According to the work device B of item 2 - 1, it includes a prime mover 7a for rotationally driving the rotary work body 6, and an output of the prime mover 7a is transmitted directly or indirectly to the rotary work body 6. Therefore, the need for drive transmission from the traveling vehicle (work vehicle A) side is eliminated. Thereby, the drive load on the traveling vehicle (work vehicle A) side can be reduced. Also, since the work device B drives the rotary work body 6 with the prime mover 7a provided therein, it can be driven while reducing drive transmission losses due to mechanical resistance and the like. Therefore, the work device B can be driven sufficiently while reducing the load on the work vehicle A.

[0193] (Item 2 - 2) The work device B according to item 2 - 1, wherein the output of the prime mover 7a is transmitted directly or indirectly to either one of the end portions of the rotary work body 6 in the width direction (second direction).

[0194] According to the working device B of Item 2-2, since the output of the prime mover 7a is transmitted directly or indirectly to either one of the both ends of the rotary working body 6 in the width direction (second direction), the output of the prime mover 7a can be efficiently and reliably transmitted to the rotary working body 6 while having a simple configuration.

[0195] (Item 2-3) The working device B according to Item 2-2 includes a drive transmission mechanism 7b that transmits the output of the prime mover 7a to the rotary working body 6. The prime mover 7a has an output shaft 70a, and the drive transmission mechanism 7b transmits the rotation of the output shaft 70a to one end of the rotary working body 6.

[0196] According to the working device B of Item 2-3, since it includes a drive transmission mechanism 7b that transmits the output of the prime mover 7a to the rotary working body 6, the prime mover 7a has an output shaft 70a, and the drive transmission mechanism 7b transmits the rotation of the output shaft 70a to one end of the rotary working body 6, the output of the prime mover 7a can be reliably transmitted to the rotary working body 6.

[0197] (Item 2-4) The rotary working body 6 has shaft portions 601, 601 centered on an axis at one end. The prime mover 7a is arranged with the output shaft 70a parallel or substantially parallel to the shaft portions 601. The drive transmission mechanism 7b includes an output gear attached to the output shaft 70a and an input gear attached to the shaft portions 601, 601, the input gear meshing directly or indirectly with the output gear. The working device B according to Item 2-3.

[0198] According to the working device B of Item 2-4, since the rotary working body 6 has shaft portions 601, 601 centered on an axis at one end, the prime mover 7a is arranged with the output shaft 70a parallel or substantially parallel to the shaft portions 601, 601, and the drive transmission mechanism 7b includes an output gear attached to the output shaft 70a and an input gear attached to the shaft portions 601, 601, the input gear meshing directly or indirectly with the output gear, the output of the prime mover 7a can be reliably transmitted to the rotary working body 6 through the gear group including the output gear and the input gear.

[0199] (Item 2-5) The rotary working body 6 has shaft portions 601, 601 centered on an axis at one end. The prime mover 7a is arranged with the output shaft 70a parallel or substantially parallel to the shaft portions 601, 601. The drive transmission mechanism 7b includes an output sprocket 71a attached to the output shaft 70a, an input sprocket 71b attached to the shaft portions 601, 601, and a chain 71c wound around the output sprocket 71a and the input sprocket 71b, which is the working device B described in Item 2-3.

[0200] According to the working device B of Item 2-5, the rotary working body 6 has shaft portions 601, 601 centered on an axis at one end. The prime mover 7a is arranged with the output shaft 70a parallel or substantially parallel to the shaft portions 601, 601. The drive transmission mechanism 7b includes an output sprocket 71a attached to the output shaft 70a, an input sprocket 71b attached to the shaft portions 601, 601, and a chain 71c wound around the output sprocket 71a and the input sprocket 71b. Therefore, the output of the prime mover 7a can be transmitted in the order of the output sprocket 71a, the chain 71c, the input sprocket 71b, and the rotary working body 6. Since the output of the prime mover 7a can be transmitted to the rotary working body 6 with such a simple configuration, the loss of drive energy (transmission loss) can be suppressed.

[0201] (Item 2-6) The frame structure 8 includes a support frame 81 extending in the width direction (second direction) and a pair of support portions 82, 83 extending downward from both ends of the support frame 81. The rotary working body 6 is arranged below the support frame 81, and both ends of the rotary working body 6 are supported by the pair of support portions 82, 83. The prime mover 7a is attached to the support frame 81 or one of the support portions 82, which is the working device B described in Item 2-3.

[0202] According to the working device B of Item 2-6, the frame structure 8 includes a support frame 81 extending in the width direction (second direction), and a pair of support portions 82 and 83 extending downward from both end portions of the support frame 81. The rotating working body 6 is disposed below the support frame 81, and both end portions of the rotating working body 6 are supported by the pair of support portions 82 and 83. Therefore, the rotating working body 6 can be supported stably and reliably. Further, since the prime mover 7a is attached to the support frame 81 or one of the support portions 82, the prime mover 7a can also be supported stably and reliably.

[0203] (Item 2-7) The working device B according to Item 2-6, wherein one of the pair of support portions 82 and 83 that supports the end portion is a cover that covers the drive transmission mechanism 7b.

[0204] According to the working device B of Item 2-7, since one of the pair of support portions 82 and 83 that supports the end portion is a cover that covers the drive transmission mechanism 7b, the weight of the device can be reduced by using one of the support portions 82 as a cover that covers the drive transmission mechanism 7b.

[0205] (Item 2-8) The working device B according to Item 2-3, comprising a cover that covers the drive transmission mechanism 7b, and the prime mover 7a is disposed in contact with or close to the cover. The working device B according to Item 2-3, comprising a cover that covers the drive transmission mechanism 7b, and the prime mover 7a is disposed in contact with or close to the cover. Therefore, the prime mover 7a is disposed at a position close to the drive transmission mechanism 7b. That is, since the prime mover 7a and the rotating working body 6 are disposed at positions close to each other, the loss until the output of the prime mover 7a is transmitted to the rotating working body 6 can be suppressed.

[0206]

[0207] (Item 2-9) The working device B according to Item 2-3, comprising a skid 75 disposed below the drive transmission mechanism 7b and movable in contact with the ground, and the skid 75 is directly or indirectly connected to the frame structure 8 and receives a load acting downward.

[0208] According to the working device B of Item 2-9, a skid 75 is provided which is arranged below the drive transmission mechanism 7b and is movable in contact with the ground. The skid 75 is directly or indirectly connected to the frame structure 8 and receives a load acting downward, so that the working device B can be prevented from being unnecessarily tilted due to the weight (load) of the prime mover 7a and the drive transmission mechanism 7b. That is, when the prime mover 7a and the drive transmission mechanism 7b are arranged on either one side in the width direction (second direction) of the device (the direction in which the rotation axis 60 of the rotary working body 6 extends), a moment acts around the center (starting point) of the rotation axis 60 of the rotary working body 6. Accordingly, the working device B tends to tilt to either one side in the width direction (second direction), but according to the working device B of Item 2-9, since the skid 75 arranged below the drive transmission mechanism 7b and in contact with the ground supports either one side of the rotary working body 6, the working device B is prevented from being unnecessarily tilted. Further, since the skid 75 is movable in contact with the ground, it does not impede the movement (advancement) of the working device B due to the running of the traveling vehicle (working vehicle A).

[0209] (Item 2-10) The working device B according to Item 2-9, comprising a rotating disk body 76 arranged at a position ahead of the skid 75 when the traveling vehicle is running, the rotating disk body 76 being rotatable around an inclined axis that rises upward toward the rear side in the traveling direction of the traveling vehicle and on the side of the front-rear center line CL passing through the center in the width direction (second direction) of the traveling vehicle.

[0210] According to the working device B of Item 2-10, since the working device B comprises a rotating disk body 76 arranged at a position ahead of the skid 75 when the traveling vehicle is running, the rotating disk body 76 being rotatable around an inclined axis that rises upward toward the rear side in the traveling direction of the traveling vehicle and on the side of the front-rear center line CL passing through the center in the width direction (second direction) of the traveling vehicle, the rotating disk body 76 removes stones and lumps of soil in front of the advancing skid 75 during working. Thereby, the advancement of the skid 75 when the skid 75 moves in contact with the ground becomes smooth.

[0211] (Item 2-11) The working device B according to any one of items 2-1 to 2-10, wherein the prime mover 7a is arranged at a position that projectingly overlaps the rotating working body 6 when viewed from a direction orthogonal to the width direction (second direction) of the traveling vehicle.

[0212] According to the working device B of item 2-11, since the prime mover 7a is arranged at a position that projectingly overlaps the rotating working body 6 when viewed from a direction orthogonal to the width direction (second direction) of the traveling vehicle, the prime mover 7a does not protrude from the rotating working body 6 in the width direction (second direction). Thereby, it is possible to prevent the prime mover 7a from coming into contact with the surroundings during the operation of the working device B.

[0213] (Item 2-12) The prime mover 7a is an electric motor 26 and is driven by receiving power supply from the traveling vehicle. Item 2 -11 of the described working device B.

[0214] According to the working device B of item 2-12, since the prime mover 7a is an electric motor 26 and is driven by receiving power supply from the traveling vehicle, there is no generation of exhaust gas like an internal combustion engine, and it can contribute to environmental improvement and the like.

[0215] Note that the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the gist of the present invention.

[0216] For example, in the above-described embodiment, although electric hydraulic cylinders are adopted for each of the pair of actuators 21R and 21L of the coupling mechanism 2 of the work vehicle A, the present invention is not limited thereto. For example, each of the pair of actuators 21R and 21L of the coupling mechanism 2 may be a hydraulic cylinder 27 connected to a hydraulic circuit provided in the work vehicle A. However, even in this case, as in the above-described embodiment, it goes without saying that the hydraulic circuit is configured such that the pair of hydraulic cylinders 27 can operate (extend and contract) independently. Further, each of the pair of actuators 21R and 21L of the coupling mechanism 2 is not limited to hydraulic pressure, and may be an electric cylinder having an electric motor 26. That is, each of the pair of actuators 21R and 21L of the coupling mechanism 2 may be an electric cylinder including an electric motor 26 and a conversion mechanism that converts the rotational output of the electric motor 26 into a linear motion, the conversion mechanism being configured to linearly move a rod 271a to move the rod 271a in and out of a cylinder tube 270.

[0217] In the above-described embodiment, an electric motor is adopted for the prime mover 7a of the first working device B, but the present invention is not limited thereto. For example, the prime mover 7a of the working measure may be a small internal combustion engine (small engine). Even in this case, since the small internal combustion engine (small engine) has an output shaft 70a, by arranging the output shaft 70a of the small internal combustion engine (small engine) in the same manner as the output shaft 70a of the above-described electric motor 26, the same operations and effects as those of the above-described embodiment can be achieved.

[0218] In the above-described embodiment, the first working device B transmits the output of the prime mover 7a to one end of the rotary working body 6, but it is not limited thereto. For example, as shown in FIG. 20, the prime mover 7a may be arranged so that the output shaft 70a of the prime mover 7a corresponds to an arbitrary position (the central position in FIG. 20) between both ends in the second direction (axial direction) of the rotary working body 6. In this case, an output sprocket 71a is attached to the output shaft 70a of the prime mover 7a, and an input sprocket 71b is attached to an arbitrary position between both ends in the second direction (axial direction) of the main shaft portion 600 of the rotary working body (rotor) 6, at a position corresponding to the arrangement of the output shaft 70a of the prime mover 7a (the central position in FIG. 20). By passing a chain 71c around the output sprocket 71a and the input sprocket 71b, the output of the prime mover 7a can be transmitted to the rotary working body 6. In this case, a cover 79 that covers the drive transmission mechanism 7b (the output sprocket 71a, the input sprocket 71b, and the chain 71c) may be arranged separately from the support portions 82 and 83 that support the rotary working body 6.

[0219] In the above-described embodiment, each of the first working device B and the second working device B includes one rotary working body 6 (rotary 6, cage roller 6), but it is not limited thereto. For example, as shown in FIGS. 21 to 21L, the working device B may include a plurality (two or more) of rotary working bodies 6, and the plurality of rotary working bodies 6 may be arranged with a displacement in the second direction. In this case, as shown in FIGS. 21 and 22, the plurality of rotary working bodies 6 may be arranged in a row in the second direction. Further, as shown in FIGS. 23 and 24, the plurality of rotary working bodies 6 may be arranged with a displacement in the second direction such that adjacent rotary working bodies 6 are displaced in the first direction and partially overlap (partially projectively overlap) when viewed from the first direction.

[0220] As described above, when the working device B includes a plurality of rotary working bodies 6 that are displaced in the second direction, the overall length (overall width) of the working device B in the second direction becomes long, and thus the rotary working bodies 6 protrude outward beyond both side surfaces of the work vehicle A (vehicle body 1) in the second direction. Therefore, in these cases where the working device B becomes an obstruction during travel or when no work is being performed, it is preferable that the rotary working bodies 6 at both ends among the plurality of horizontally arranged rotary working bodies 6 be configured to be able to stand upright upward.

[0221] More specifically described, this type of working device B includes a frame structure 8 including a connecting portion 80 connectable to a traveling vehicle, and a plurality of rotary working bodies 6 pivotally supported by the frame structure 8, each of the plurality of rotary working bodies 6 being rotatable about an axis extending in the second direction of the traveling vehicle.

[0222] In this type of working device B as well, when the rotary working body 6 is a rotary 6, it includes a plurality of prime movers 7a provided corresponding to each of the plurality of rotary working bodies 6, the plurality of prime movers 7a for rotationally driving the corresponding rotary working bodies 6, and the output of the prime movers 7a is transmitted directly or indirectly to the rotary working bodies 6.

[0223] The frame structure 8 of this type of working device B has a first frame 8a including the connecting portion 80, and a pair of second frames 8b connected to both ends of the first frame 8a, the pair of second frames 8b rotatably supporting the rotary working bodies 6 at both ends in the second direction.

[0224] The first frame 8a has a support frame (referred to as the first support frame) 81a extending in the second direction. The connecting portion 80 is connected to the first support frame 81a. Specifically, similar to the first working device B and the second working device B, the connecting portion 80 includes a pair of lower connecting portions 80a corresponding to the latching members 23R and 23L of the pair of lower links 20R and 20L on the work vehicle A side or the pair of lower latching portions 25a and 25a of the connecting frame 24. Further, in the present embodiment, the connecting portion 80 includes an upper connecting portion 80b corresponding to the tip of the upper link 22 or the upper latching portion 25b of the connecting frame 24. The pair of lower connecting portions and the upper connecting portion are the same in configuration as in the above embodiment except that they are connected to the first support frame 81a. Therefore, by reading the support frame 81 in the description of the pair of lower connecting portions 80a and the upper connecting portion 80b of the first working device B or the second working device B above as the first support frame 81a, the description of the pair of lower connecting portions and the upper connecting portion 80b here is obtained, and thus the description here is omitted.

[0225] The first support frame 81a has a pair of frame connecting portions 850 and 850 to which adjacent second frames 8b are connected. The pair of frame connecting portions 850 and 850 are symmetrically arranged with respect to a virtual plane (virtual reference plane) VS that extends in the first direction and the third direction along a center line passing through the central position of the first support frame 81a. A connected portion 860, which will be described later, of the adjacent second frames 8b and 8b is rotatably connected to the frame connecting portion 850 about an axis extending in the first direction.

[0226] Each of the pair of frame connecting portions 850 is arranged at a position where there is no interference between the surrounding components (for example, the second frames 8b related to adjacent rotating working bodies 6, the prime mover 7a, the cover, etc.) when the second frame 8b is rotated to stand up (the rotating working body 6 is stood up) and when the second frame 8b is in the standing state.

[0227] As shown in FIG. 21, when the working device B includes two rotary working bodies 6, 6, the first frame 8a has the above-described configuration. On the other hand, as shown in FIGS. 22 to 24, when the working device B includes three or more rotary working bodies 6, the first frame 8a, in addition to the above-described configuration, includes a pair of support portions 82a, 83a connected to the first support frame 81a, and the pair of support portions 82a, 83a rotatably supports both ends of the rotary working body 6 located at the center in the second direction among the three rotary working bodies 6. The rotary working body 6 at the center is disposed below the first support frame 8 1a.

[0228] In this case, the rotary working body 6 located at the center among the three rotary working bodies 6... has the drive of the prime mover 7a transmitted to the central position in the second direction. That is, the prime mover 7a, the drive transmission mechanism 7b, and the cover covering the drive transmission mechanism 7b are arranged in the same manner as the working device B shown in FIG. 20.

[0229] Then, as shown in FIGS. 21 to 24, in either case where the working device B includes two rotary working bodies 6, 6 or where the working device B includes three or more rotary working bodies 6, each of the pair of second frames 8b, 8b includes a support frame (referred to as a second support frame) 81b extending in the second direction and a pair of support portions 82b, 83b extending downward from both ends of the second support frame 81b, and the pair of support portions 82b, 83b rotatably supports both ends (shaft portions) of the rotary working body 6. The pair of second frames 8b, 8b supports the rotary working body 6 located at the outermost end in the second direction, so the prime mover 7a, the drive transmission mechanism 7b, and the cover (the other support portion 83b) are arranged in the same manner as the first working device B or in the manner shown in FIG. 20. In FIGS. 22 to 24, the case of the same arrangement as the first working device B is illustrated. However, the pair of second frames 8b, 8b are symmetrically arranged with respect to the virtual reference plane VS so that the drive transmission mechanism 7b is located at the outermost side. Accordingly, a skid 75 and a rotating disk body 76 are also attached to the second frame 8b.

[0230] As is clear from the respective figures, the relationship between the second frame 8b and the rotary working body 6, the relationship between these and the prime mover 7a, the drive transmission mechanism 7b, etc., and the relationship between the skid 75 and the rotary disk body 76, etc. are the same as those of the first working device B. Therefore, the description here will be omitted by referring to the description of the first working device B.

[0231] And the second frame 8b has a connected portion 860 to be connected to the frame connection portion 850 of the first frame 8a on the end side where there is no prime mover 7a, drive transmission mechanism 7b, etc. of the second support frame 81b. The connected portion 860 is rotatably connected to the frame connection portion 850 around an axis extending in the first direction. Accordingly, this type of working device B includes a pair of swing actuators 870, 870 for rotating (swinging) each of the pair of second frames 8b on both sides in the second direction around the axis in the first direction. That is, it includes a pair of actuators 870, 870 for switching the postures of the rotary working bodies 6 at both ends between the normal lying state and the standing state. Accordingly, actuator connection portions 851, 861 for connecting the actuator 870 are provided on the first frame 8a and the second frame 8b. The pair of swing actuators 870, 870 employ a cylinder device that expands and contracts by driving an electric motor. The pair of swing actuators 870, 870 are connected to the actuator connection portion 851 of the first frame 8a and the actuator connection portion 861 of the second frame 8b. The actuator connection portion 851 of the first frame 8a is set at a higher position in the third direction than the actuator connection portion 861 of the second frame 8b. Accordingly, the pair of swing actuators 870, 870 are arranged in a posture that slopes downward from the first frame 8a side toward the second frame 8b side. This inclined direction coincides with the expansion and contraction direction of the cylinder device.

[0232] The electric motor of the actuator 870 receives power supply from the work vehicle A. Here, for each of the pair of swing actuators 870, 870, an electro-hydraulic cylinder is adopted in the same way as the actuators 21R, 21L of the connecting mechanism 2 of the work vehicle A. Along with this, the working device B is provided with a power line (cable) that supplies power to the electric motor and can be connector-connected to the power output system (external output circuit) of the work vehicle A. Along with this, by the operator operating the second operating device 14 of the work vehicle A, the pair of swing actuators 870, 870 can be extended and retracted.

[0233] Note that the working device B shown in FIGS. 21 and 22 is arranged such that the adjacent rotary working bodies 6 are concentric or concentric. However, as shown in FIG. 23, the first frame 8a (the central rotary working body 6) and the second frame 8b (the end rotary working body 6) may be arranged with a shift in the first direction and the first frame 8a and the second frame 8b may be arranged with partial overlap in the second direction. In this way, since the working ranges by the rotary working bodies 6 are continuous or overlapping, the formation of an unworked area can be prevented.

[0234] As described above, since the working device B has a plurality of rotary working bodies 6, the working range becomes wider. By setting the second frames 8b (rotary working bodies 6) at both ends in an upright state, the amount of protrusion from both ends of the work vehicle A of the working device B can be suppressed, so that it is suppressed that the working device B gets in the way when no work is being done (for example, during traveling). Also, since the working device B is provided with a prime mover 7a corresponding to each of the plurality of rotary working bodies 6, the rotation conditions of each rotary working body 6 can also be made different. That is, in a field or the like, the soil quality and moisture may vary depending on the location. Therefore, by making the rotation conditions of each rotary working body 6 different, work corresponding to the location of the work target becomes possible. Also, if a forming machine for forming the terrain is attached corresponding to each of the plurality of rotary working bodies 6, tilling (cultivation) and forming (forming ridges, etc.) suitable for that location become possible.

[0235] As is clear from the above description, the configuration (basic configuration) related to the rotary working bodies 6 at both ends is the same as that of the first working device B and the like, and the configuration (basic configuration) related to the central rotary working body 6 when there are three rotary working bodies 6 is the same as the working device B shown in FIG. 20. Therefore, the same operations and effects as these can be obtained. Although not particularly mentioned, this type of working device B can be provided with the configurations provided in the first working device B (for example, the working body cover 9, the detection sensor 95, etc.). In the above description, the output of the prime mover 7a that drives the rotary working bodies 6 at both ends in the second direction is transmitted to the ends of the rotary working bodies 6. In this case, since the drive transmission mechanism 7b is located outside the rotary working bodies 6 in the second direction, the size of the working device B in the second direction increases. Considering this point, the prime mover 7a and the drive transmission mechanism 7b that drive each rotary working body 6 may be arranged within the range of the rotary working body 6 in the second direction as in the aspect shown in FIG. 20.

[0236] Each of the above working devices B was a tillage tractor for cultivating (tilling) the soil, but it is not limited to this. For example, the working device B may be provided with a rotary brush as the rotary working body 6.

[0237] In the above embodiment, the second working device B is provided with a winged subsoiler as the tillage member 780, but the tillage member 780 is not limited to the winged subsoiler. For example, the tillage member 780 may be a subsoiler without wings. Further, as shown in FIG. 25, the tillage member 780 may be a short disk (disc) that is rotatable around an axis that is inclined obliquely downward toward the front side with respect to the center line passing through the center in the second direction of the work vehicle A (vehicle body 1). Also in this case, as with the subsoiler, a plurality are arranged in the second direction. Note that the short disk has a plurality of recesses formed at intervals (equally spaced or substantially equally spaced) in the circumferential direction with respect to the peripheral edge. That is, the short disk has a plurality of concavities and convexities formed on its outer periphery.

[0238] In the above embodiment, the second working device B has the cage roller 6 rotatably supported by the support portions 82 and 83 fixed to the support frame 81, so that the cage roller 6 is disposed at a fixed position, but is not limited thereto. For example, as shown in FIG. 26, each of the pair of support portions 82 and 83 may be rotatably connected to the support frame 81 about an axis extending in the second direction (for example, about the center line of the support frame 81), and the cage roller 6 may be rotatable about the rotation center of the support portions 82 and 83. In this way, by rotating the cage roller 6 about the rotation center of the support portions 82 and 83, the height position of the cage roller 6 can be changed. In this case, it is preferable that the working device B includes a rotation actuator (for example, an electric motor or an electro-hydraulic motor) 88 about an axis extending in the second direction (for example, about the center line of the support frame 81). In this way, by operating (for example, expanding and contracting) the actuator 88, the cage roller 6 can be rotated about the rotation center of the support portions 82 and 83, and by stopping the operation (for example, expanding and contracting) of the actuator 88, the cage roller 6 can be maintained at a fixed position.

[0239] In the above embodiment, each working device B is not limited to including a transmitter 96 (transmitter) that transmits (sends) the detection results of the angle sensors S3 and S3. That is, on the premise that the work vehicle A includes the receiver 16, each working device B includes the transmitter 96, but when the work vehicle A does not include the receiver 16, it is not limited thereto. For example, when the work vehicle A does not include the receiver 16, angle sensors S3 and S3 that output the angle of the detection cover 91 of the working device B may be provided on the work vehicle A, and a transmission wire that transmits the tilting of the detection cover 91 to the angle sensors S3 and S3 may be arranged across the work vehicle A and the working device B. In this case, the transmission wire on the work vehicle A and the transmission wire on the working device B side may be separated, and when the working device B is connected to the work vehicle A, a connection mechanism may be provided that can transmit the axial movement (axial force) of the transmission wire on the working device B side to the transmission wire on the work vehicle A.

[0240] In the above-described embodiment, in the first working device B, the rotary 6 as a rotary working body tills (cultivates) the soil as it is, and in the second working device B, the tilling member 780 and the cage roller 6 as a rotary working body till (cultivate) the soil as it is. However, before tilling (cultivating) the soil, plants (such as secondary ears and weeds) growing in the soil may be cut.

[0241] Specifically, when the working device B is a tillage tractor equipped with the rotary working body 6, as shown in FIG. 27, the working device B may be provided with a cutting device 65 for cutting plants growing in the soil in front of the rotary working body 6 (when the tilling member 780 is provided, further in front of the tilling member 780). That is, the working device B may be provided with a cutting device 65 disposed in front of the tillage means (the rotary working body 6, the tilling member 780) for tilling the soil. The cutting device 65 can adopt, for example, one equipped with a clipper or a saw blade-shaped cutting edge. Also, the cutting device 65 may cut plants in a range corresponding to the working range (tillage (cultivation) range) in the second direction by the tillage means (the rotary working body 6, the tilling member 780). In this way, the cut plants (especially secondary ears) will be buried when the tillage means (the rotary working body 6, the tilling member 780) tills the soil, thus contributing to soil improvement.

Explanation of Reference Numerals

[0242] 1: Vehicle body 2: Link mechanism 6: Rotary working body 7a: Prime mover 7b: Drive transmission mechanism 8: Frame structure 20L: Lower link 20R: Lower link 20a: First end 20b: Second end 21R: Actuator (cylinder device: electro-hydraulic cylinder) 21L: Actuator (cylinder device: electro-hydraulic cylinder) 22: Upper link 22a: Base end 22b: Tip end 23R: Hanging member 23L: Hanging member 24: Connecting frame 25: Hanging portion 26: Electric motor 27: Hydraulic cylinder (fluid cylinder) 70a: Output shaft 71a: Output sprocket 71b: Input sprocket 71c: Chain 75: Skid 76: Rotating disk body 80: Connecting portion 81: Support frame 81a: Support frame (first support frame) 81b: Support frame (second support frame) 82: Supporting portion 82a: Supporting portion 82b: Supporting portion 83: Supporting portion 83a: Supporting portion 83b: Supporting portion 240: Spherical bearing 280: Hydraulic pump 601: Shaft portion A: Work vehicle B: Working device (first working device, second working device) H1: Connecting position (pin insertion hole: through hole) H2: Connecting position S3: Angle sensor CL: Center line

Claims

1. A travelable vehicle body, and a coupling mechanism attached to the vehicle body, the coupling mechanism coupling and supporting a working device, wherein the coupling mechanism is a pair of lower links each having a first end rotatably coupled to the vehicle body about an axis extending in the width direction of the vehicle body and a second end opposite to the first end, the pair of lower links being spaced apart in the width direction of the vehicle body, and the working device being directly or indirectly coupled to the second end, and a pair of actuators arranged corresponding to each of the pair of lower links, the pair of actuators each swinging the corresponding lower link about the axis, and the pair of actuators are each independently operable work vehicle.

2. Each of the pair of actuators is a cylinder device configured to be extendable and contractible in one direction and having an electric motor driven to extend and contract itself, and is arranged to straddle the corresponding lower link and the vehicle body, and both ends in the one direction are coupled to the lower link and the vehicle body. The work vehicle according to claim 1.

3. Each of the pair of actuators is a hydraulic pump that discharges hydraulic oil to extend and contract itself, and is an electro-hydraulic cylinder including a hydraulic pump driven by the electric motor. The work vehicle according to claim 2.

4. A plurality of connection positions connectable to at least one of the lower link and the actuator are set on at least one of the lower link and the actuator, wherein the coupling mechanism is provided with an angle sensor that detects a rotation angle about the axis of each of the pair of lower links. The work vehicle according to claim 2.

5. The coupling mechanism is a coupling frame that couples the second ends of the pair of lower links, and has a latching portion capable of latching the working device. Both ends of the coupling frame are supported by the respective second ends of the pair of lower links via spherical bearings. The work vehicle according to claim 1.

6. The coupling mechanism is a pair of latching members capable of latching the working device, and has a pair of latching members each coupled to the second end of each of the pair of lower links. The work vehicle according to claim 1.

7. The coupling mechanism has an upper link disposed above the pair of lower links, The upper link includes a base end portion rotatably connected to the vehicle body about an axis extending in the width direction, and a tip end portion on the opposite side of the base end portion. The work vehicle according to claim 5, wherein the tip end portion is rotatably connected to the connection frame about an axis extending in the width direction. **Claim 8** The connection mechanism has an upper link disposed above the pair of lower links. The upper link has a base end portion rotatably connected to the vehicle body about an axis extending in the width direction, and a tip end portion on the opposite side of the base end portion. The work vehicle according to claim 6, wherein the tip end portion of the upper link can latch the work device.

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