Work vehicle

Abstract

To provide a technology that increases working efficiency of mowing work.SOLUTION: A mower serving as a work vehicle comprises a traveling machine body, and a mowing device that is connected to the traveling machine body. The mowing device has a rotary mowing blade. The rotary mowing blade automatically switches between rotational directions when a direction of travel of the traveling machine body is changed.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a work vehicle.

Background Art

[0002] Patent Document 1 discloses a lawn mower including a traveling body and a lawn mowing device connected to the traveling body. The lawn mowing device is provided with a cutting blade, and the lawn mowing operation is performed by rotationally driving this cutting blade.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the lawn mowing operation by a rotationally driven cutting blade, the rotation direction of the cutting blade is set in a direction suitable for lawn mowing according to the state of the grass and the like. Further, when performing the lawn mowing operation while reciprocating the lawn mower, usually, it is desirable that the cutting blade rotates in the above-described rotation direction suitable for lawn mowing both on the forward pass and the return pass. During operation, if the cutting blade is configured to rotate only in one direction and an attempt is made to perform lawn mowing in a rotation direction suitable for lawn mowing both on the forward pass and the return pass, it is necessary to reverse the direction of the lawn mower between the forward pass and the return pass. Such a reversing operation may reduce the working efficiency.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide a technique for improving the working efficiency of the lawn mowing operation.

Means for Solving the Problems

[0006] The work vehicle according to one aspect of the present invention includes a traveling body and a grass cutting device connected to the traveling body. The grass cutting device has a rotary cutting blade, and when the traveling direction of the traveling body is changed, the rotation direction of the rotary cutting blade is automatically switched.

Effects of the Invention

[0007] According to the above configuration, the working efficiency of the grass cutting operation can be improved.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0009] Embodiments of the present invention will be described as follows with reference to the drawings.

[0010] 〔1. Schematic Configuration of Work Vehicle〕 FIG. 1 is a diagram showing a schematic configuration of a lawn mower 1 which is an example of a work vehicle according to an embodiment of the present invention. The lawn mower 1 includes a vehicle body 10 and a remote control device 200 provided separately from the vehicle body 10.

[0011] The remote operation device 200 (also called a remote control device) enables an operator located at a position away from the vehicle body 10 to operate the vehicle body 10. The configuration of the remote operation device 200 will be described later.

[0012] In this embodiment, the remote operation device 200 is provided separately from the vehicle body 10, but the configuration is not limited to this. For example, the remote operation device 200 may be provided on the vehicle body 10 itself. In the case of a configuration where the remote operation device 200 is provided on the vehicle body 10, for example, the shape, arrangement, type, etc. of the operation members (see FIG. 3) described later included in the remote operation device 200 may be appropriately changed.

[0013] The vehicle body 10 includes a traveling body 11 that travels on the ground, a mowing device 12 (also called a cutting device) that performs mowing work, and a hitch portion 13 that enables the mowing device 12 to be connected to the traveling body 11. That is, the mower 1 includes the traveling body 11, the mowing device 12, and the hitch portion 13.

[0014] Here, the directions used in the description (especially the directions related to the vehicle body 10) are defined as follows. When the traveling body 11 travels straight along one direction, one side of the above one direction is defined as "front" and the other side is defined as "rear". Among the directions in which the traveling body 11 travels straight along one direction, the side where the hitch portion 13 is not arranged is defined as "front", and the opposite side (the side where the hitch portion 13 is arranged) is defined as "rear". Also, the left side when looking from the rear to the front is defined as "left", and the right side is defined as "right". Further, the gravitational direction perpendicular to the front-rear direction and the left-right direction is defined as the up-down direction, the upstream side of the gravitational direction is defined as "up", and the downstream side is defined as "down". In the drawings, if necessary, the front is indicated by the symbol "F", the rear is indicated by "B", the right is indicated by "R", the left is indicated by "L", the up is indicated by "U", and the down is indicated by "D". Note that these directions are merely names used for explanation and do not intend to limit the actual positional relationship and direction.

[0015] The traveling body 11 includes a body main body portion 111 and a traveling portion 112 disposed below the body main body portion 111.

[0016] The body main unit 111 includes an outer cover 111a, a traveling drive device 111b disposed on the inner front side covered by the outer cover 111a, and a PTO (Power Take Off) device 111c disposed on the inner rear side covered by the outer cover 111a.

[0017] The traveling drive device 111b includes a first motor EM1 as a drive source and a power transmission mechanism (not shown) that transmits the power from the first motor EM1 to the traveling unit 112. In this embodiment, the first motor EM1 is an electric motor. Note that the drive source included in the traveling drive device 111b may be other than an electric motor, for example, an engine.

[0018] The PTO device 111c includes a second motor EM2 as a drive source and a first power transmission unit (not shown) that enables the power from the second motor EM2 to be transmitted to the outside of the traveling machine body 11. In this embodiment, the second motor EM2 is an electric motor. Note that the drive source included in the PTO device 111c may be other than an electric motor, for example, an engine. Also, in this embodiment, the first motor EM1 and the second motor EM2 are provided separately, but the electric motors (drive sources) may be shared by the traveling drive device 111b and the PTO device 111c.

[0019] Inside the outer cover 111a, a battery that supplies power to the first motor EM1 and the second motor EM2, power electronics equipment, etc. are also arranged. Outside the outer cover 111a, as an example, a light 111d, a positioning antenna 111e, an alarm lamp 111f, etc. are arranged.

[0020] Note that in this embodiment, the traveling machine body 11 is not provided with an operator's seat, that is, the vehicle body 10 performs mowing work unmanned. However, the present invention is also applicable to a mower provided with an operator's seat on the traveling machine body 11. That is, the traveling machine body 11 may have instruments (such as a handle and a lever) for an operator sitting on the operator's seat to operate the mower.

[0021] The running gear 112 supports the airframe main body 111 so that it can run. Specifically, the running gear 112 includes a pair of left and right crawlers 112a. Each of the left and right crawlers 112a includes a track frame 112b extending in the front-rear direction. Each track frame 112b is attached to the lower surface of the airframe main body 111. A drive sprocket 112c is arranged as a drive wheel at the front end of the track frame 112b. The drive sprocket 112c transmits the power from the first motor via the above-described power transmission mechanism provided in the travel drive device 111b. A driven sprocket 112d is arranged as a driven wheel at the rear end of the track frame 112b. The driven sprocket 112d is rotatably supported by the track frame 112b. In the track frame 112b, a plurality of idlers 112e are rotatably supported between the drive sprocket 112c and the driven sprocket 112d. A crawler belt 112f is wound around the drive sprocket 112c, the driven sprocket 112d, and the plurality of idlers 112e to form the crawler 112a.

[0022] Each of the left and right crawlers 112a is driven by a separate first motor EM1 provided in the travel drive device 111b. When the pair of left and right crawlers 112a are simultaneously driven in the same direction, the running gear 112 moves straight forward or backward. Whether it moves forward or backward is determined by the rotation direction of the output shaft of the first motor EM1. For example, when the pair of left and right crawlers 112a are independently driven, the running gear 112 makes a left turn or a right turn.

[0023] In this embodiment, the crawler 112a has a configuration in which one drive wheel (drive sprocket 112c) and one driven wheel (driven sprocket 112d) are arranged side by side in the front-rear direction and the crawler belt 112f is wound around them, but other configurations may also be used. For example, the crawler may be of a type in which a crawler belt is wound around one drive wheel and two driven wheels in a triangular shape. Also, in this embodiment, the running gear 112 is of the crawler type, but it may be of a type other than the crawler type, for example, a wheel type.

[0024] The mowing device 12 is disposed behind the hitch portion 13. The hitch portion 13 is configured to include a PTO device 111c. The mowing device 12 is attached to the traveling body 11 via the hitch portion 13 so as to be liftable. That is, the mowing device 12 is connected to the traveling body 11 by the hitch portion 13. In the present embodiment, the mowing device 12 is disposed behind the traveling body 11. However, the present invention is also applicable to a mower 1 in which the mowing device 12 is disposed in front of the traveling body 11.

[0025] Further, the mowing device 12 is detachably attached to the hitch portion 13. Therefore, it is also possible to attach a different type of mowing device 12 from the mowing device 12 shown in FIG. 1 to the traveling body 11 via the hitch portion 13. Further, it is also possible to attach a working device (for example, a tiller) that enables work other than mowing work (for example, tilling) to the traveling body 11 and perform the above work.

[0026] The configuration of the mowing device 12 will be described with reference to FIG. 2. FIG. 2 is a plan view showing the configuration of the mowing device 12. In the present embodiment, the mowing device 12 is a flail mower. The mowing device 12 includes a cutter cover 121, a rotary cutter 122 disposed so as to be covered by the cutter cover 121, and a second power transmission unit 123 that enables power transmission to the rotary cutter 122.

[0027] The rotary cutter 122 rotates in the clockwise direction (see arrow A1 in FIG. 1, also referred to as the A1 direction) or the counterclockwise direction (see arrow A2 in FIG. 1, also referred to as the A2 direction) when the mowing device 12 is viewed from the left. More specifically, the rotary cutter 122 includes a rotary shaft portion 122a and a plurality of cutter blades 122b. As particularly shown in FIG. 2, the rotary shaft portion 122a is a shaft extending in the left-right direction. That is, the axial direction of the rotary shaft portion 122a is arranged along the left-right direction. Specifically, the rotary shaft portion 122a is rotatably supported by bearing portions (not shown) provided at the left end portion 122aL and the right end portion 122aR at the left side portion and the right side portion of the mowing device 12, respectively. That is, the rotary shaft portion 122a is rotatable about an axis AX along the left-right direction. Thereby, the rotary cutter 122 can rotate in the A1 direction or the A2 direction.

[0028] On the outer peripheral surface of the rotary shaft portion 122a, a plurality of cutting blades 122b are swingably attached. Each cutting blade 122b extends from the center side of the rotary shaft portion 122a toward the outside. At each end portion 122b1 on the tip side (the side opposite to the side attached to the rotary shaft portion 122a) in the rotation direction (A1 direction or A2 direction) of each cutting blade 122b, a blade is formed. Further, in each cutting blade 122b, the portion where the blade is formed is bent obliquely toward the left or the right (see particularly FIG. 2). The rotary cutting blade 122 is configured by attaching a pair of cutting blades 122b bent obliquely to the left and a cutting blade 122b bent obliquely to the right to each attachment portion 122a1 of the rotary shaft portion 122a.

[0029] The rotary shaft portion 122a is rotationally driven by the power from the PTO device 111c being transmitted by the second power transmission portion 123. More specifically, the second power transmission portion 123 includes a drive pulley 123a, a driven pulley 123b, and a belt 123c. The drive pulley 123a and the driven pulley 123b are connected via the belt 123c. Further, the drive pulley 123a is also connected to an input portion (not shown) included in the second power transmission portion 123. The above input portion is connected to the PTO device 111c (particularly the first power transmission portion). The driven pulley 123b is also connected to the left end portion 122aL of the rotary shaft portion 122a.

[0030] The power from the PTO device 111c, that is, the power output from the second motor EM2 and transmitted by the first power transmission portion, is transmitted to the drive pulley 123a via the input portion. Thereby, the drive pulley 123a rotates. When the drive pulley 123a rotates, the driven pulley 123b rotates via the belt 123c. That is, power is transmitted from the drive pulley 123a to the driven pulley 123b. When the driven pulley 123b rotates, the rotary shaft portion 122a connected to the driven pulley 123b rotates. Note that the configuration of the second power transmission portion 123 is not limited to the above, and for example, instead of a configuration including a pulley and a belt, a configuration including a sprocket and a chain may be used.

[0031] When the rotating shaft portion 122a rotates, the cutting blade 122b attached to the outer peripheral surface rotates around the axis AX. As described above, since a blade is formed on the cutting blade 122b, when the rotating cutting blade 122b comes into contact with the grass, the grass will be cut. That is, the grass cutting operation can be performed by the rotation-driven rotary cutting blade 122.

[0032] In addition, for the grass located on the advancing direction side of the grass cutting operation, the cutting blade 122b included in the rotary cutting blade 122 rotates from the bottom upward to cut the grass, which is called an upper cut. For example, in FIG. 1, when the traveling body 11 is advanced and the rotary cutting blade 122 is rotated in the A1 direction, it is an upper cut. Also, when the traveling body 11 is reversed and the rotary cutting blade 122 is rotated in the A2 direction, it is also an upper cut. In the upper cut, since the grass can be cut while being lifted, it is particularly suitable for cutting the grass lying on the ground. However, in the upper cut, the cut grass is likely to scatter around.

[0033] On the other hand, for the grass located on the advancing direction side of the grass cutting operation, the cutting blade 122b included in the rotary cutting blade 122 rotates from the top downward to cut the grass, which is called a down cut. For example, in FIG. 1, when the traveling body 11 is advanced and the rotary cutting blade 122 is rotated in the A2 direction, it is a down cut. Also, when the traveling body 11 is reversed and the rotary cutting blade 122 is rotated in the A1 direction, it is also a down cut. In the down cut, since the grass is cut while the cutting blade 122b is rotated from the top downward, the cut grass is less likely to scatter around compared to the upper cut.

[0034] That is, the up-cut and down-cut are realized by the rotary cutting blade 122 rotating in the A1 direction or the A2 direction. Therefore, from the perspective of ensuring the realization of the up-cut and down-cut by rotating the rotary cutting blade 122 in the A1 direction or the A2 direction, the following configuration is desirable. That is, as in the present embodiment, it is desirable that the rotary cutting blade 122 includes a rotary shaft portion 122a that rotates around an axis AX along the left-right direction.

[0035] In addition, the rotary cutting blade 122 is provided with a plurality of types of modes regarding the rotation direction. More specifically, the rotary cutting blade 122 is configured to be settable to a first rotation mode, a second rotation mode, and an automatic switching mode.

[0036] The first rotation mode is a mode in which the rotary cutting blade 122 rotates in the A1 direction regardless of the traveling direction (whether it is moving forward or backward) of the traveling body 11. Therefore, when the rotary cutting blade 122 is set to the first rotation mode, for example, when the traveling body 11 is moved forward, grass cutting work in the up-cut can be performed. Also, when the traveling body 11 is moved backward, grass cutting work in the down-cut can be performed.

[0037] The second rotation mode is a mode in which the rotary cutting blade 122 rotates in the A2 direction regardless of the traveling direction of the traveling body 11. Therefore, when the rotary cutting blade 122 is set to the second rotation mode, for example, when the traveling body 11 is moved forward, grass cutting work in the down-cut can be performed. Also, when the traveling body 11 is moved backward, grass cutting work in the up-cut can be performed.

[0038] The automatic switching mode is a mode in which the rotation direction of the rotary cutting blade 122 is automatically switched between the A1 direction and the A2 direction according to the traveling direction of the traveling body 11. The automatic switching mode includes an up-cut mode and a down-cut mode.

[0039] The upper cut mode means a mode in which the rotation direction of the rotary cutting blade 122 is automatically switched so that the grass cutting operation in the upper cut is always performed regardless of whether the traveling body 11 moves forward or backward. The down cut mode means a mode in which the rotation direction of the rotary cutting blade 122 is automatically switched so that the grass cutting operation in the down cut is always performed regardless of whether the traveling body 11 moves forward or backward.

[0040] Note that the configuration of the rotary cutting blade 122 is not limited to the above. For example, the rotary cutting blade 122 only needs to be settable to the automatic switching mode, and at least one of the first rotation mode and the second rotation mode may be omitted. Also, a mode of a type different from any of the first rotation mode, the second rotation mode, and the automatic switching mode may be added.

[0041] [2. Configuration of Remote Control Device] The configuration of the remote control device 200 will be described with reference to FIG. 3. FIG. 3 is a plan view showing the configuration of the remote control device 200. The remote control device 200 includes a housing 201, a power switch 202, an antenna 203, an operation lever 204, an operation switch 205, an operation knob 206, and a display unit 207.

[0042] The housing 201 constitutes the main body portion of the remote control device 200. The above-described power switch 202, antenna 203, operation lever 204, operation switch 205, operation knob 206, and display unit 207 are respectively attached to appropriate positions of the housing 201. Note that the arrangement shown in FIG. 3 is merely an example and may be changed as appropriate.

[0043] The power switch 202 is provided at the center of the front surface of the housing 201 and enables the power of the remote control device 200 to be turned on and off. The power switch 202 is, for example, a toggle switch. Note that the power of the remote control device 200 is, for example, a battery, a dry battery, etc. disposed in the housing 201.

[0044] The antenna 203 is provided to protrude from the side surface of the housing 201 (the upper side surface in FIG. 3), enabling wireless communication with the traveling body 11. When the power switch 202 turns on the power of the remote control device 200, the remote control device 200 can communicate wirelessly with the traveling body 11. When the power switch 202 turns off the power of the remote control device 200, the remote control device 200 cannot communicate with the traveling body 11. In this embodiment, when the traveling body 11 cannot communicate with the remote control device 200, it automatically stops traveling. That is, the power switch 202 has a function as an emergency stop switch for the traveling body 11. Note that the emergency stop switch may be provided separately from the power switch 202.

[0045] The operation lever 204 enables the operation of the traveling of the traveling body 11 and the operation of the mowing device 12. The operation lever 204 includes a first operation lever 204a and a second operation lever 204b that are arranged side by side with the power switch 202 in between. The first operation lever 204a (the left lever shown in FIG. 3) can be tilted at least in two directions (the F1-B1 direction and the L1-R1 direction) that are perpendicular to each other and are indicated by the dashed arrows in FIG. 3. Also, it can be tilted to one side in the F1-B1 direction while being tilted to one side in the L1-R1 direction. Note that the second operation lever 204b (the right lever shown in FIG. 3) can also be tilted in the same directions as the first operation lever 204a.

[0046] When the first operation lever 204a is tilted in the F1 direction, the traveling body 11 can be moved forward. When the first operation lever 204a is tilted in the B1 direction, the traveling body 11 can be moved backward. When the first operation lever 204a is tilted in the L1 direction, the traveling body 11 can be turned left. When the first operation lever 204a is tilted in the R1 direction, the traveling body 11 can be turned right. That is, by operating the first operation lever 204a of the remote control device 200, the traveling direction of the traveling body 11 can be changed. Therefore, even if a sufficient distance is ensured between the operator and the traveling body 11, the traveling body 11 can be operated. Thus, from the viewpoint of improving the safety when operating the traveling body 11, it is desirable that the lawn mower 1 be provided with a remote control device 200 capable of changing the traveling direction of the traveling body 11 as in the present embodiment.

[0047] When the second operation lever 204b is tilted in the F1 direction, the mowing device 12 can be raised. When the second operation lever 204b is tilted in the B1 direction, the mowing device 12 can be lowered. When the second operation lever 204b is tilted in the L1 direction, the traveling body 11 can be turned left. When the second operation lever 204b is tilted in the R1 direction, the traveling body 11 can be turned right.

[0048] Note that the turning radii (left turn and right turn) by the first operation lever 204a and the turning radii (left turn and right turn) by the second operation lever 204b are different when operated with the same operation amount (operation amount from the neutral position). More specifically, when the first operation lever 204a and the second operation lever 204b are tilted by the same amount from the neutral position, the traveling body 11 can be turned with a larger turning radius when operating with the second operation lever 204b than when operating with the first operation lever 204a. That is, with the second operation lever 204b, the traveling body 11 can be turned slowly.

[0049] The operation switch 205 includes a first operation switch 205a, a second operation switch 205b, a third operation switch 205c, and a fourth operation switch 205d.

[0050] The first operation switch 205a is arranged on the side surface of the housing 201 (the upper right side surface in FIG. 3). The first operation switch 205a is, for example, a pushable momentary switch. The first operation switch 205a is used when the lawn mower 1 is configured to be capable of automatic traveling. The above-mentioned automatic traveling means that in the lawn mower 1, at least the steering is automatically (autonomously) performed along a predetermined path. The automatic traveling may be configured such that at least one of, for example, the adjustment of the traveling speed and the operation by the mowing device 12 is automatically performed in addition to the steering. If the lawn mower 1 is capable of automatic traveling, the first operation switch 205a enables a plurality of types of settings related to the automatic traveling. The above-mentioned plurality of types of settings includes, for example, the start setting and the end setting of the automatic traveling.

[0051] The second operation switch 205b is arranged on the side surface of the housing 201 (the upper left side surface in FIG. 3), and can switch between a state where power transmission from the PTO device 111c to the mowing device 12 is possible and a state where it is impossible. The second operation switch 205b is, for example, a toggle switch.

[0052] The third operation switch 205c is arranged on the front surface of the housing 201 (the upper left side of the front surface in FIG. 3). The third operation switch 205c is, for example, an alternate type toggle switch that can be switched to three positions. That is, the third operation switch 205c can be switched to an F1 position (a position tilted in the F1 direction), a B1 position (a position tilted in the B1 direction), and a neutral position (a position facing a direction orthogonal to the front surface of the housing 201).

[0053] The third operation switch 205c enables settings related to the rotation direction of the rotary mowing blade 122. For example, when the third operation switch 205c is switched to the F1 position (tilted in the F1 direction), the rotary mowing blade 122 is set to the first rotation mode. When the third operation switch 205c is switched to the B1 position (tilted in the B1 direction), the rotary mowing blade 122 is set to the second rotation mode. When the third operation switch 205c is switched to the neutral position, the rotary mowing blade 122 is set to the automatic switching mode.

[0054] The fourth operation switch 205d is arranged adjacent to the third operation switch 205c (on the left adjacent side in FIG. 3). The fourth operation switch 205d is, for example, an alternate type toggle switch that can be switched to two positions. The fourth operation switch 205d also enables settings related to the rotation direction of the rotary cutting blade 122. For example, when the fourth operation switch 205d is switched to the F1 position, the automatic switching mode is set to the upper cut mode. When the fourth operation switch 205d is switched to the B1 position, the automatic switching mode is set to the down cut mode.

[0055] The operation knob 206 is arranged on the front of the housing 201 (the upper side of the front in FIG. 3) and enables adjustment of the maximum speed of the traveling machine body 11. More specifically, two operation knobs 206 are provided. One of the two operation knobs 206 enables adjustment of the maximum speed during straight running of the traveling machine body 11. The other of the two operation knobs 206 enables adjustment of the maximum speed during turning running of the traveling machine body 11.

[0056] The display unit 207 is arranged on the front of the housing 201 (the lower side of the front in FIG. 3) and displays various information to notify the operator. The various information includes, for example, the display of the traveling speed of the traveling machine body 11. The display unit 207 is, for example, a liquid crystal display device, an organic EL display device, or the like.

[0057] 〔3. Configuration related to control〕 The configuration related to the control of the lawn mower 1 will be described with reference to FIG. 4. FIG. 4 is a block diagram schematically showing the configuration related to the control of the lawn mower 1. In FIG. 4, only the components necessary for explaining the features of the present embodiment are shown, and the description of general components is omitted.

[0058] The lawn mower 1 is provided with a control device 113. The control device 113 is a computer device configured to include, for example, an arithmetic unit, an input / output unit, and a storage unit 113a. The arithmetic unit is, for example, a processor or a microprocessor. The storage unit 113a is a main storage device such as a ROM (Read Only Memory) or a RAM (Random Access Memory). The storage unit 113a may further include an auxiliary storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). Various programs, data, etc. are stored in the storage unit 113a. The arithmetic unit reads out various programs from the storage unit 113a and executes arithmetic processing according to the programs. The programs stored in the storage unit 113a may be provided, for example, by a computer-readable non-volatile recording medium. As another example, the programs may be provided from a program-providing server via a communication line such as the Internet.

[0059] Through the cooperation of the above-mentioned hardware and software, the control device 113 can be operated as a travel control unit 113b, a lift control unit 113c, and a PTO control unit 113d. The control device 113 may be composed of one piece of hardware or may be composed of a plurality of pieces of hardware capable of communicating with each other.

[0060] Note that each functional unit 113b to 113d included in the control device 113 may be realized by software, that is, by causing an arithmetic unit to execute arithmetic processing according to a program as described above, but may also be realized by other methods. At least one of the functional units 113b to 113d may be realized using, for example, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or the like. That is, at least one of the functional units 113b to 113d may be realized by hardware using a dedicated IC or the like. Further, at least one of the functional units 113b to 113d may be realized by using a combination of software and hardware. Also, the functional units 113b to 113d are conceptual configurations. Therefore, the functions executed by one component may be distributed among a plurality of components, or the functions of a plurality of components may be integrated into one component.

[0061] The traveling control unit 113b controls the traveling drive device 111b (see FIG. 1) based on a traveling instruction from the remote operation device 200 (for example, a forward instruction by the first operation lever 204a).

[0062] The lifting control unit 113c adjusts the lifting position (height from the ground) of the mowing device 12 based on a lifting instruction from the remote operation device 200 (for example, a rising instruction by the second operation lever 204b).

[0063] The PTO control unit 113d controls the PTO device 111c (see FIG. 1) based on a switching instruction from the remote operation device 200 (for example, a transmission instruction by the second operation switch 205b), and switches the power transmission to the mowing device 12. Further, the PTO control unit 113d makes a setting related to the rotation direction of the rotary mowing blade 122 based on a setting instruction from the remote operation device 200 (for example, a mode setting instruction by the third operation switch 205c). That is, the PTO control unit 113d sets the rotary mowing blade 122 to any one of a first rotation mode, a second rotation mode, and an automatic switching mode. Further, the PTO control unit 113d controls the PTO device 111c based on the above setting related to the rotation direction, and controls the rotation direction of the power (rotational power) transmitted to the mowing device 12.

[0064] In addition to the above functions, the PTO control unit 113d controls the PTO device 111c to adjust the rotation speed of the rotary mowing blade 122. For example, the PTO control unit 113d controls the PTO device 111c so that the rotary mowing blade 122 rotates at the rated rotation speed except when the rotation direction of the rotary mowing blade 122 automatically switches. The case where the rotation direction of the rotary mowing blade 122 automatically switches will be described later.

[0065] A positioning communication unit 114, a communication processing unit 115, and a sensor 116 are connected to the control device 113. That is, the lawn mower 1 includes a positioning communication unit 114, a communication processing unit 115, and a sensor 116.

[0066] The positioning communication unit 114 includes a positioning antenna 111e (see FIG. 1), and uses the positioning signal received by the positioning antenna 111e from a positioning satellite to obtain the position of the vehicle body 10, for example, as information on latitude and longitude. The positioning communication unit 114 performs positioning by using, for example, the known RTK-GNSS (Real Time Kinematic GNSS) method after receiving a positioning signal from a reference station (not shown) by an appropriate method. The positioning communication unit 114 outputs the position information of the vehicle body 10 to the control device 113. Note that the positioning communication unit 114 may perform positioning by using other methods such as the DGNSS (Differential GNSS) method. Further, the lawn mower 1 may be configured to include, instead of or in addition to the positioning communication unit 114, for example, a positionable quantum compass.

[0067] The communication processing unit 115 communicates with the remote operation device 200 via the communication antenna 115a. The communication antenna 115a is an antenna for performing wireless communication with the remote operation device 200. For the wireless communication, a wireless LAN (Local Area Network) such as Wi-Fi (registered trademark) may be used.

[0068] The sensor 116 detects information related to the vehicle body 10 and outputs the detected information to the control device 113. In the present embodiment, the sensor 116 includes a plurality of types of sensors. Each of the plurality of types of sensors is connected to the control device 113 so as to be able to input a signal. The plurality of types of sensors include, for example, an inertial measurement device, an obstacle sensor, a vehicle speed sensor, and a lifting position sensor.

[0069] The inertial measurement device includes a three-axis angular velocity sensor and a three-directional acceleration sensor, and is a device capable of measuring the attitude of the traveling body 11. The obstacle sensor is a sensor that detects obstacles existing around the vehicle body 10, and may be, for example, an ultrasonic sensor, a camera, a radar, or a LiDAR (Light Detection And Ranging). The vehicle speed sensor is a sensor that detects the vehicle speed of the traveling body 11. The lifting position sensor is a sensor that detects the lifting position of the lawn mowing device 12.

[0070] Note that the positioning communication unit 114 and some sensors 116 (such as an inertial measurement unit) are used when the lawn mower 1 runs automatically. That is, the positioning communication unit 114 and some sensors 116 are not essential for the lawn mower 1 to run based on instructions from the remote control device 200.

[0071] [4. Automatic switching of the rotation direction of the rotary cutting blade] The automatic switching of the rotation direction of the rotary cutting blade 122 will be described. As described above, the automatic switching of the rotation direction is performed in the automatic switching mode. First, the rotation direction of the rotary cutting blade 122 in the automatic switching mode will be described with reference to FIG. 5. FIG. 5 is an explanatory diagram for explaining the rotation direction of the rotary cutting blade 122 in the automatic switching mode. FIG. 5 shows the case where the automatic switching mode is set to the upper cut mode.

[0072] As shown in the upper diagram in FIG. 5, when the rotary cutting blade 122 is set to the upper cut mode in the automatic switching mode, when the traveling body 11 is advanced, the rotary cutting blade 122 rotates in the A1 direction. That is, while the traveling body 11 is advanced, the lawn mowing operation in the upper cut is performed. As shown in the lower diagram in FIG. 5, when the traveling body 11 is reversed, the rotary cutting blade 122 rotates in the A2 direction. That is, while the traveling body 11 is reversed, the lawn mowing operation in the upper cut is performed. Therefore, if the rotary cutting blade 122 is set to the upper cut mode, the lawn mowing operation in the upper cut can always be performed whether the traveling body 11 is advanced or reversed.

[0073] If the rotary cutting blade 122 is set to the down-cut mode, grass cutting operation in the down-cut mode can always be performed regardless of whether the traveling machine body 11 moves forward or backward. More specifically, when the rotary cutting blade 122 is set to the down-cut mode, the rotary cutting blade 122 rotates in a direction opposite to that when it is set to the upper-cut mode. That is, when the traveling machine body 11 moves forward, the rotary cutting blade 122 rotates in the A2 direction, and when the traveling machine body 11 moves backward, the rotary cutting blade 122 rotates in the A1 direction.

[0074] Next, the flow when the automatic switching of the rotation direction is started will be described with reference to FIG. 6. FIG. 6 is a flowchart showing the flow when the automatic switching of the rotation direction is started. The flowchart shown in FIG. 6 is started, for example, at the timing when the control device 113 (see FIG. 4) recognizes the start of the grass cutting operation by the grass cutter 1. The start of the grass cutting operation may be, for example, at the same timing as the start of the operation of the grass cutting device 12. In this case, when the control device 113 gives an instruction to start the operation of the grass cutting device 12, the flowchart shown in FIG. 6 is started.

[0075] In step S1, the PTO control unit 113d (see FIG. 4) determines whether there is an instruction to change the traveling direction of the traveling machine body 11. In the present embodiment, the above-mentioned change instruction is realized by the operator switching the first operation lever 204a from one side to the other side in the F1-B1 direction (see FIG. 3). For example, the change instruction is realized by switching the first operation lever 204a from the F1 direction to the B1 direction. In this case, the traveling machine body 11 switches from forward movement to backward movement. That is, the change instruction in the present embodiment is an instruction to change the traveling direction of the traveling machine body 11 from one side to the other side in the front-rear direction (for example, from the front to the rear). If there is a change instruction (Yes in step S1), the process proceeds to the next step S2. If there is no change instruction (No in step S1), the PTO control unit 113d continues to determine the change instruction.

[0076] Note that the change instruction is not limited to the above. For example, when the lawn mower 1 is configured to be capable of autonomous driving, the change instruction may be as follows. That is, in autonomous driving, an instruction to switch from the path on which the lawn mower 1 is autonomously driving to a path different from the above path (for example, an adjacent path) may be used as the change instruction.

[0077] In step S2, the PTO control unit 113d executes a process of automatically switching the rotation direction of the rotary mowing blade 122. More specifically, the PTO control unit 113d controls the second motor EM2 (see FIG. 1) of the PTO device 111c to reverse the rotation direction of the output shaft of the second motor EM2. As described above, the power from the second motor EM2 is transmitted to the rotary shaft portion 122a of the rotary mowing blade 122 via the first power transmission unit of the PTO device 111c and the second power transmission unit 123 of the mowing device 12 (see FIG. 1). Therefore, when the rotation direction of the output shaft of the second motor EM2 is reversed, the rotation direction of the rotary shaft portion 122a is also reversed. That is, the rotation direction of the rotary mowing blade 122 is also reversed. Therefore, when the traveling direction of the traveling body 11 is changed, the rotation direction of the rotary shaft portion 122a, that is, the rotation direction of the rotary mowing blade 122 is automatically switched without the operator operating the remote control device 200 or the like.

[0078] According to the above configuration, by changing the traveling direction of the traveling body 11, the rotation direction of the rotary mowing blade 122 is automatically switched. Therefore, the rotary mowing blade 122 can be rotated in a rotation direction suitable for mowing without reversing the direction of the traveling body 11, and the work efficiency of the mowing operation can be improved.

[0079] Also, from the viewpoint of surely realizing a configuration in which the rotary mowing blade 122 is rotated in a rotation direction suitable for mowing, the following configuration is desirable. That is, in the configuration in which the rotary mowing blade 122 includes the rotary shaft portion 122a as in the present embodiment, it is desirable that the rotation direction of the rotary shaft portion 122a is switched as the traveling direction of the traveling body 11 is changed.

[0080] In particular, in the mowing operation performed while reciprocating the traveling body 11, the rotary mowing blade 122 can be rotated in a rotation direction suitable for mowing both on the forward pass and the return pass without reversing the direction of the traveling body 11. Therefore, in the mowing operation involving the reciprocation of the traveling body 11, from the viewpoint of improving work efficiency, the following configuration is desirable. That is, as in the present embodiment, it is desirable that when the traveling direction of the traveling body 11 is changed from one side to the other side in the front-rear direction, the rotation direction of the rotary mowing blade 122 is reversed.

[0081] When the rotation direction of the rotary mowing blade 122 automatically switches, the rotary mowing blade 122 gradually reduces its rotational speed and stops in the rotation direction before the switch. After stopping, the rotary mowing blade 122 gradually increases its rotational speed in the rotation direction after the switch. More specifically, it is as follows. FIG. 7 is a flowchart showing the flow of control of the rotational speed during automatic switching of the rotation direction. The flowchart shown in FIG. 7 starts, for example, at the timing when the above-mentioned change instruction is given.

[0082] In step S11, the PTO control unit 113d controls the PTO device 111c to reduce the rotational speed of the rotary mowing blade 122. For example, the PTO control unit 113d decreases (gradually reduces) the control current output to the PTO device 111c by a predetermined amount at predetermined time intervals. As a result, the rotational speed of the rotary mowing blade 122 gradually decreases. When the rotational speed decreases, the process proceeds to the next step S12.

[0083] In step S12, the PTO control unit 113d determines whether or not the rotary mowing blade 122 has stopped. In the present embodiment, whether or not the rotary mowing blade 122 has stopped is determined based on the rotational speed of the output shaft of the second motor EM2 (see FIG. 1). The rotational speed of the output shaft of the second motor EM2 is detected by a rotational speed sensor (not shown) provided in the PTO device 111c. The above-mentioned rotational speed sensor is connected to the control device 113 (see FIG. 4) so as to be able to input a signal.

[0084] Note that the determination of whether or not the rotary cutting blade 122 has stopped is not limited to the above. For example, the determination of the stop of the rotary cutting blade 122 may be made based on the rotational speed of the rotary cutting blade 122 (rotating shaft portion 122a) itself. That is, a configuration may be provided in which a rotational speed sensor is provided in the grass cutting device 12 to detect the rotational speed of the rotary cutting blade 122.

[0085] When the rotary cutting blade 122 is rotating (No in step S12), the process returns to step S11. Therefore, until the rotation of the rotary cutting blade 122 stops, the processes of step S11 and step S12 are repeated. That is, until the rotation of the rotary cutting blade 122 stops, the rotational speed of the rotary cutting blade 122 gradually decreases. When the rotation of the rotary cutting blade 122 stops (Yes in step S12), the process proceeds to the next step S13.

[0086] In step S13, the PTO control unit 113d controls the PTO device 111c to increase the rotational speed of the rotary cutting blade 122. For example, the PTO control unit 113d increases (increases slightly) the control current output to the PTO device 111c by a predetermined amount at predetermined time intervals. Thereby, the rotational speed of the rotary cutting blade 122 gradually increases. At this time, the PTO control unit 113d controls the PTO device 111c so that the rotational direction of the rotary cutting blade 122 is opposite to that before the stop of the rotation (steps S11 and S12). When the rotational speed increases, the process proceeds to the next step S14.

[0087] In step S14, the PTO control unit 113d determines whether or not the rotational speed of the rotary cutting blade 122 has reached the target rotational speed. In the present embodiment, the above target rotational speed is the same as the rotational speed at the time when the automatic switching of the rotational direction is started. Note that the target rotational speed is not limited to the above and may be different from the rotational speed at the time when the automatic switching is started.

[0088] If the rotational speed has not reached the target rotational speed (No in step S14), the process returns to step S13. Therefore, the processes of step S13 and step S14 are repeated until the rotational speed reaches the target rotational speed. That is, after the rotation of the rotary cutting blade 122 stops, the rotational speed of the rotary cutting blade 122 gradually increases and finally reaches the target rotational speed. When the rotational speed reaches the target rotational speed (Yes in step S14), the automatic switching of the rotational direction is completed.

[0089] If the automatic switching of the rotational direction is performed smoothly, it is possible to avoid damage to the members (for example, the PTO device 111c and the second power transmission unit 123) that are directly or indirectly connected to the rotary cutting blade 122. From this perspective, as shown in FIG. 7, when automatically switching the rotational direction of the rotary cutting blade 122, it is desirable for the lawn mower 1 to gradually decrease the rotational speed of the rotary cutting blade 122 and stop the rotary cutting blade 122. Then, after the rotary cutting blade 122 stops, it is desirable to gradually increase the rotational speed to the target rotational speed.

[0090] [[5. Supplementary Note]] The lawn mower 1 described in this embodiment can also be expressed as a work vehicle shown in the following supplementary note.

[0091] The work vehicle of Supplementary Note (1) is a traveling body, and a lawn mowing device connected to the traveling body, and the lawn mowing device has a rotary cutting blade, and when the traveling direction of the traveling body is changed, the rotational direction of the rotary cutting blade automatically switches.

[0092] The work vehicle of Supplementary Note (2) is the work vehicle described in Supplementary Note (1), where when the traveling direction of the traveling body is changed from one side to the other side in the front-rear direction of the traveling body, the rotational direction of the rotary cutting blade reverses.

[0093] The work vehicle of Supplementary Note (3) is the work vehicle described in Supplementary Note (1) or (2), where when switching the rotational direction of the rotary cutting blade, Gradually reduce the rotational speed of the rotary cutting blade to stop the rotary cutting blade, After the rotary cutting blade stops, gradually increase the rotational speed of the rotary cutting blade to a target rotational speed.

[0094] The work vehicle of Supplementary Note (4) is the work vehicle described in any one of Supplementary Notes (1) to (3), The rotary cutting blade includes a rotary shaft portion that rotates about an axis along the left - right direction of the traveling body, As the traveling direction of the traveling body changes, the rotational direction of the rotary shaft portion switches.

[0095] The work vehicle of Supplementary Note (5) is the work vehicle described in any one of Supplementary Notes (1) to (4), It is provided with a remote control device capable of changing the traveling direction of the traveling body.

[0096] As described above, the embodiments of the present invention have been explained. However, the scope of the present invention is not limited to this, and it can be implemented with expansion or modification without departing from the gist of the invention. Also, a plurality of embodiments and modification examples shown in this specification may be combined and implemented within the possible range.

Industrial Applicability

[0097] The present invention can be used for work vehicles such as agricultural machines and construction machines, for example.

Explanation of Signs

[0098] 1 Lawn mower (work vehicle) 11 Traveling body 12 Grass cutting device 122 Rotary cutting blade 122a Rotary shaft portion 200 Remote control device AX axis

Claims

1. A work vehicle comprising: a traveling body; and a mowing device connected to the traveling body, wherein the mowing device has a rotary cutting blade, and when the traveling direction of the traveling body is changed, the rotary direction of the rotary cutting blade is automatically switched.

2. The work vehicle according to claim 1, wherein when the traveling direction of the traveling body is changed from one side to the other side in the longitudinal direction of the traveling body, the rotary direction of the rotary cutting blade is reversed.

3. When switching the rotary direction of the rotary cutting blade, the rotational speed of the rotary cutting blade is gradually decreased to stop the rotary cutting blade, and after the rotary cutting blade stops, the rotational speed of the rotary cutting blade is gradually increased to a target rotational speed.

4. The work vehicle according to claim 1, wherein the rotary cutting blade includes a rotary shaft portion that rotates about an axis along the lateral direction of the traveling body, and the rotary direction of the rotary shaft portion is switched as the traveling direction of the traveling body is changed.

5. The work vehicle according to any one of claims 1 to 4, further comprising a remote control device capable of changing the traveling direction of the traveling body.

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