AUTONOMOUS TRAVELING WORK APPARATUS

An autonomous traveling work apparatus includes a work unit including a passive rotary cutter that passively rotates, a driving rotary cutter that is driven to rotate, and a fixed cutter that does not rotate. The passive rotary cutter has a rotation axis passing through a rotation center thereof and oriented in a direction intersecting the front-rear direction of a vehicle body, and includes a plurality of blade parts on the outer peripheral portion of the passive rotary cutter. The fixed cutter is adjacent to the passive rotary cutter. The driving rotary cutter has a rotation axis passing through a rotation center thereof and oriented in the direction intersecting the front-rear direction of the vehicle body, and rotates by means of a drive device. The driving rotary cutter cuts the vegetation above the lower end of the passive rotary cutter.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an autonomous traveling work apparatus capable of performing work while autonomously traveling.

Description of the Related Art

JP 2021-153507 A discloses an autonomous traveling work apparatus for mowing grass such as lawn while autonomously traveling. The autonomous traveling work apparatus recognizes a boundary between lawn to be mowed and a structure and cuts an edge of the lawn along the boundary.

The autonomous traveling work apparatus includes a cutter blade provided so as to protrude from a side portion of the vehicle body. When the autonomous traveling work apparatus is switched to an operating state for cutting the edge of the lawn, the cutter blade is lowered toward the ground. In the operating state, a portion of the cutter blade sequentially contacts the ground. In this state, another portion of the cutter blade cuts the edge of the lawn.

SUMMARY OF THE INVENTION

When the cutting edge of the cutter blade becomes worn, it is necessary to grind or replace the cutter blade. That is, maintenance is required. When the cutting edge of the cutter blade is easily worn, the frequency of maintenance increases.

An object of the present invention is to solve the above-mentioned problem.

According to an aspect of the present invention, there is provided an autonomous traveling work apparatus comprising: a traveling wheel provided on a vehicle body; a control unit configured to control the traveling wheel; and a work unit configured to mow vegetation, wherein the work unit includes: a passive rotary cutter that is rotatably supported on a side portion of the vehicle body, has a rotation center oriented in a direction intersecting a front-rear direction of the vehicle body, and includes a plurality of blade parts on an outer peripheral portion of the passive rotary cutter; a fixed cutter that is disposed on the side portion of the vehicle body, faces the outer peripheral portion of the passive rotary cutter, and is configured not to rotate; and a driving rotary cutter that is supported on the side portion of the vehicle body, has a rotation center oriented in the direction intersecting the front-rear direction, and is configured to rotate by means of a drive device, and wherein the passive rotary cutter passively rotates in response to the passive rotary cutter receiving a ground reaction force as the autonomous traveling work apparatus travels, and the driving rotary cutter cuts the vegetation above a lower end of the passive rotary cutter.

According to the above configuration, the driving rotary cutter is prevented from coming into contact with the ground when edging for cutting vegetation in the vertical direction is performed. Therefore, wear of the driving rotary cutter is suppressed. As a result, the replacement frequency of the driving rotary cutter is reduced, so that the running cost of the autonomous traveling work apparatus can be reduced.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, the term “front (forward)” represents a normal traveling direction of an autonomous traveling work apparatus10as shown inFIG.1. The term “rear (rearward)” represents the direction opposite to the “front (forward)”. The terms “left” and “right” represent the left and right sides, respectively, when a user of the autonomous traveling work apparatus10views the front from the rear of the autonomous traveling work apparatus10. Therefore, the term “vehicle width direction” of a vehicle body12of the autonomous traveling work apparatus10is synonymous with the “left-right direction”. Further, in the following description, lawn is exemplified as vegetation in order to simplify the description and facilitate understanding, but the vegetation is not limited to lawn. Examples of vegetation other than lawn include weeds.

FIG.1is a schematic plan view of the autonomous traveling work apparatus10according to the present embodiment. The autonomous traveling work apparatus10includes the vehicle body12and traveling wheels14. The traveling wheels14include a left rear wheel16L and a right rear wheel16R, which are driving wheels, and a left front wheel18L and a right front wheel18R, which are driven wheels. The autonomous traveling work apparatus10further includes a control unit20that controls the traveling wheels14, and a work unit50that mows lawn.

While specifying the position of the autonomous traveling work apparatus10based on a position signal from the GNSS satellite, the control unit20controls the left rear wheel16L and the right rear wheel16R, which are driving wheels, based on map data stored in the control unit, thereby moving the vehicle body12to an edge of the lawn. Since this control is a known technique described in JP 2021-153507 A, a detailed description thereof will be omitted. The edge of the lawn is a boundary Q between a lawn surface Gr and a portion Ro other than the lawn surface Gr. The portion Ro other than the lawn surface Gr is, for example, a sidewalk, a roadway, or the like.

A battery22is mounted on the vehicle body12. The battery22supplies electric power to the traveling wheels14and the work unit50. In the present embodiment, the work unit50is disposed at the left side portion of the vehicle body12. The battery22is disposed close to the right side portion of the vehicle body12. Therefore, a center of gravity22G of the battery22is shifted toward the right side portion from a center line L in the vehicle width direction. As a result, the weight of the autonomous traveling work apparatus10can be balanced in the vehicle width direction.

The work unit50has a function of mowing the edge of lawn.FIG.2is a schematic perspective view of the work unit50, andFIG.3is a vertical cross-sectional view of the work unit50viewed along the vehicle width direction of the vehicle body12. A bracket26is provided at the left side portion of the vehicle body12. The work unit50is held by the vehicle body12via the bracket26. The work unit50includes a support section60and a cutting section200. The support section60includes a first holding member62and a second holding member64. The cutting section200includes a drive device210, a driving rotary cutter230, a passive rotary cutter250, and a fixed cutter270.

As shown inFIG.2, a first engaging portion30is provided on a side surface28of the bracket26that faces outward in the vehicle width direction. The first engaging portion30includes a first rail32aand a second rail32b. The first rail32aand the second rail32bextend in the up-down direction. An elongated hole34is formed in the side surface28of the bracket26, between the first rail32aand the second rail32b. The elongated hole34is close to the second rail32b.

As shown inFIG.3, a moving device100is disposed in the vicinity of the bracket26in the vehicle body12. The moving device100includes a movement motor102, a two-stage gear104, and a moving table108provided with a rack106. Alternatively, the moving device100may be a cylinder or a coil spring.

An output shaft110of the movement motor102extends downward. A worm112is provided at a lower end of the output shaft110. The two-stage gear104includes an input tooth portion116provided on a side wall of a large diameter portion114, and a pinion120provided on a side wall of a small diameter portion118. The worm112meshes with the input tooth portion116. The pinion120meshes with the rack106. The moving table108is connected to a first vertical wall portion70of the first holding member62constituting the support section60, via a connecting bolt111passed through the elongated hole34. When the movement motor102is driven and the output shaft110rotates, the pinion120follows the rotation and rotates. With this follow-up rotation, the moving table108provided with the rack106and the support section60connected to the moving table108move upward or downward.

A second engaging portion72is provided on a surface of the first vertical wall portion70that faces inward in the vehicle width direction and faces the bracket26. The second engaging portion72includes a first guide plate74ainserted into the first rail32a, and a second guide plate74binserted into the second rail32b. The first guide plate74aand the second guide plate74bare connected to the first holding member62via connecting bolts113. The first guide plate74ais slidable within the first rail32a. Similarly, the second guide plate74bis slidable within the second rail32b. As can be understood from this, the second engaging portion72engages with the first engaging portion30so as to be movable in the up-down direction.

A first horizontal wall portion76that extends outward in the vehicle width direction is provided at an upper end of the first vertical wall portion70. The first horizontal wall portion76is substantially orthogonal to the first vertical wall portion70. Similarly, the second holding member64includes a second vertical wall portion78extending in the up-down direction, and a second horizontal wall portion80provided at an upper end of the second vertical wall portion78. The second horizontal wall portion80extends inward in the vehicle width direction and is placed on the first horizontal wall portion76. In this state, the first horizontal wall portion76and the second horizontal wall portion80are connected to each other. A predetermined clearance CL is formed between the first vertical wall portion70and the second vertical wall portion78.

The drive device210is disposed inward of the first vertical wall portion70in the vehicle width direction. The drive device210is supported by the first vertical wall portion70. In the present embodiment, the drive device210is a rotation motor212. The rotation motor212includes a rotation shaft214extending in the horizontal direction. The rotation shaft214is inserted through a first shaft insertion hole82formed in the first vertical wall portion70, and extends outward in the vehicle width direction. Here, the rotation shaft214includes a drive shaft218of the rotation motor212, and an extension shaft220connected to a distal end of the drive shaft218. As the drive shaft218rotates, the extension shaft220rotates integrally with the drive shaft218.

The drive shaft218constituting the rotation shaft214supports the driving rotary cutter230. The driving rotary cutter230includes a rotating body232and blades234. As shown inFIGS.3and4, the rotating body232has a hollow cup shape. The drive shaft218is inserted into a recess240of the rotating body232through a second shaft insertion hole238formed in a bottom portion236of the rotating body232that faces the rotation motor212. A nut138is attached to the drive shaft218in the recess240of the rotating body232. The bottom portion236of the rotating body232is sandwiched between the nut138and a stopper140that is attached to the drive shaft218. As a result, the rotating body232is supported by the drive shaft218.

In the present embodiment, the driving rotary cutter230includes three blades234. A holding hole242is formed in one blade234. A holding bolt244protruding from the recess240to the outside of an outer surface of the bottom portion236is passed through the holding hole242. A holding nut246is screwed onto the holding bolt244. As a result, the blades234are held by the rotating body232. When a predetermined load or more is applied to each of the blades234, the blade234can rotate relative to the rotating body232about the holding bolt244.

Alternatively, the driving rotary cutter230may be configured by integrally providing the blades234on an outer peripheral portion of the rotating body232. In this case, the blades234each extend outward in the radial direction of the rotating body232from the outer peripheral portion of the rotating body232.

In the recess240of the rotating body232, the extension shaft220is connected to the distal end of the drive shaft218. The nut138is sandwiched between the bottom portion236of the rotating body232and an end surface of the extension shaft220.

The extension shaft220supports the passive rotary cutter250via a first bearing142in a relatively rotatable manner. Therefore, the rotation center of the driving rotary cutter230and the rotation center of the passive rotary cutter250are the rotation shaft214. That is, the rotation center of the driving rotary cutter230and the rotation center of the passive rotary cutter250coincide with each other. Since the driving rotary cutter230and the passive rotary cutter250can be simultaneously supported by the rotation shaft214, the configuration of the cutting section200is simplified.

In the present embodiment, the axis of the rotation shaft12, which serves as the rotation center of the driving rotary cutter230and the rotation center of the passive rotary cutter250, is oriented in the vehicle width direction, which is one of the horizontal directions. However, the axis of the rotation shaft12may be oriented in a direction intersecting the front-rear direction of the vehicle body12. That is, the axis of the rotation shaft12may not be oriented in the horizontal direction. For example, the axis of the rotation shaft12may be inclined upward as the distance from the vehicle body12increases. Further, it is not essential that the rotation center of the driving rotary cutter230and the rotation center of the passive rotary cutter250coincide with each other. In other words, the rotation center of the driving rotary cutter230and the rotation center of the passive rotary cutter250may not coincide with each other.

The extension shaft220is passed through a first inner hole148formed in a first cylindrical portion146of a first bearing holder144. The first bearing142is disposed in the first inner hole148. A first circular plate portion150of the first bearing holder144has a surface facing outward in the vehicle width direction, and a second circular plate portion156of a first cover154is disposed on this surface. A second cylindrical portion158of the first cover154covers the first cylindrical portion146.

The passive rotary cutter250includes a disk part252, and a plurality of blade parts254provided on an outer peripheral portion of the disk part252. A circular plate portion insertion hole256is formed in the disk part252. The second circular plate portion156of the first cover154is inserted into the circular plate portion insertion hole256. The diameter of the circular plate portion insertion hole256is substantially equal to the outer diameter of the second circular plate portion156. In this state, the disk part252is connected to the first circular plate portion150of the first bearing holder144.

The first bearing142is interposed between the extension shaft220(a part of the rotation shaft214) and the passive rotary cutter250. The first bearing142prevents the passive rotary cutter250from rotating in accordance with the rotation of the rotation shaft214.

The distal end of the extension shaft220is supported by the second holding member64via a second bearing166. Specifically, the extension shaft220is passed through a third shaft insertion hole81formed in the second holding member64, and is further passed through a second inner hole170formed in a third cylindrical portion168of a second bearing holder172. The second bearing166is disposed in the second inner hole170. A third circular plate portion174of the second bearing holder172is connected to the second holding member64. A fourth circular plate portion176of a second cover175is disposed on a surface of the third circular plate portion174that faces outward in the vehicle width direction. A fourth cylindrical portion178of the second cover175covers the third cylindrical portion168. A threaded portion184of a plug bolt182is inserted into a connecting hole180formed at the distal end of the extension shaft220.

The second holding member64includes two protrusions82aand82b. The two protrusions82aand82bextend inward in the vehicle width direction from a surface of the second holding member64that faces inward in the vehicle width direction. The two protrusions82aand82bare arranged side by side in the up-down direction. The fixed cutter270includes a body portion272and a blade body274. In the body portion272, two through holes276aand276bare formed side by side in the up-down direction. The two protrusions82aand82bare passed through the two through holes276aand276b, respectively. Further, cap nuts278aand278bare put on the two protrusions82aand82b, respectively. The cap nuts278aand278bserve to prevent the protrusions82aand82bfrom coming off the through holes276aand276b, respectively.

The lower protrusion82ais passed through a coil spring190, which is an elastic member. In other words, the lower protrusion82ais surrounded by the coil spring190. One end of the coil spring190is in contact with the surface of the second holding member64that faces inward in the vehicle width direction. The other end of the coil spring190passes through the through hole276aand is wound around a side portion of the cap nut278a. Therefore, the coil spring190elastically biases the body portion272of the fixed cutter270toward the disk part252of the passive rotary cutter250.

The second bearing166is interposed between the extension shaft220(the rotation shaft214) and the second holding member64. The rotation shaft214is rotatably supported by the second holding member64via the second bearing166.

The body portion272of the fixed cutter270is bent so as to approach the disk part252of the passive rotary cutter250. As shown inFIG.2, the blade body274of the fixed cutter270has an inclined portion275that is inclined downward from the front to the rear.

A shearing region SS is formed by the blade body274of the fixed cutter270and the blade part254of the passive rotary cutter250. Therefore, the shearing region SS is provided below a shearing mechanism constituted by the fixed cutter270and the passive rotary cutter250. As understood fromFIGS.3and4, the blade234constituting the driving rotary cutter230is located above the lower end of the passive rotary cutter250(the blade part254located at the lowermost position). Further, the blade234is located above the shearing region SS.

In the above-described configuration, the driving rotary cutter230, the passive rotary cutter250, and the fixed cutter270are disposed in the clearance CL formed between the first vertical wall portion70of the first holding member62and the second vertical wall portion78of the second holding member64.

Next, an operation of the autonomous traveling work apparatus10will be described.

The user inputs a mowing height of the lawn to the control unit20via a command input unit24provided on the vehicle body12. The control unit20moves the work unit50according to the mowing height that has been input. For example, when lowering the work unit50, the control unit20drives the movement motor102. As a result, the output shaft110and the worm112rotate integrally. Since the input tooth portion116of the two-stage gear104meshes with the worm112, the input tooth portion116and the pinion120rotate. Since the rack106meshes with the pinion120, the pinion120and the moving table108are lowered integrally.

As described above, the first holding member62constituting the support section60is connected to the moving table108. Therefore, as the moving table108is lowered, the support section60and the cutting section200are lowered integrally. At this time, the first guide plate74aand the second guide plate74bforming the second engaging portion72are lowered while being guided by the first rail32aand the second rail32bforming the first engaging portion30. When the blade234of the driving rotary cutter230reaches the height position corresponding to the mowing height, the control unit20stops the movement motor102.

When raising the work unit50, the control unit20sets the rotation direction of the output shaft110of the movement motor102to the direction opposite to the rotation direction when lowering the work unit50.

The autonomous traveling work apparatus10travels based on the map data stored in advance in the control unit20. That is, the control unit20performs control so that the vehicle body12moves to the boundary Q between the lawn surface Gr and the portion Ro other than the lawn surface Gr (the road or the like). The boundary Q is the edge of the lawn. The control unit20receives a position signal from the GNSS satellite and specifies the position of the autonomous traveling work apparatus10. The inclined portion275of the fixed cutter270serves as a relief portion when the fixed cutter270comes into contact with a curb or the like.

When the autonomous traveling work apparatus10travels, the left rear wheel16L and the right rear wheel16R are driven to rotate, and the left front wheel18L and the right front wheel18R follow the rotation and rotate. When the blade part254constituting the passive rotary cutter250is in contact with the ground, the blade part254receives a ground reaction force. As the individual blade parts254sequentially receive the ground reaction force, the passive rotary cutter250rotates. As described above, the passive rotary cutter250is a shearing blade. In addition, the rotational speed of the passive rotary cutter250is a speed corresponding to the traveling speed of the autonomous traveling work apparatus10and is relatively low. For the above-described reason, the blade part254of the passive rotary cutter250is prevented from being worn in a short period of time due to contact of the blade part254with the ground.

When the vehicle body12reaches the edge of the lawn, the control unit20drives the rotation motor212which is the drive device210. As a result, the rotation shaft214(the drive shaft218and the extension shaft220) and the rotating body232supported by the rotation shaft214rotate. In accordance therewith, the blades234constituting the driving rotary cutter230rotate.

In the lawn, a portion near the ground is pinched and sheared between the blade part254of the passive rotary cutter250and the blade body274of the fixed cutter270. In this way, edging for cutting the edge of the lawn is performed by the passive rotary cutter250and the fixed cutter270. When a large amount of lawn grass is pinched between the blade part254and the blade body274, the coil spring190contracts. When a small amount of lawn grass is pinched between the blade part254and the blade body274, the coil spring190extends. In this manner, the distance between the blade part254and the blade body274is adjusted in accordance with the amount of lawn grass. Therefore, it is easy to shear the lawn in the shearing region SS.

The driving rotary cutter230cuts the lawn above the lower end of the passive rotary cutter250. That is, as shown inFIG.4, in the autonomous traveling work apparatus10, a working region A1, which is the shearing region SS, and a working region A2of the driving rotary cutter230are different from each other. Specifically, the working region A2of the driving rotary cutter230is above the working region A1, which is the shearing region SS.

The autonomous traveling work apparatus10may include a rotary cutter (work unit) for mowing the lawn surface Gr. In this case, the rotary cutter (work unit) is provided, for example, at a lower portion of the vehicle body12constituting the autonomous traveling work apparatus10.

The present embodiment exhibits the following effects.

The work unit50of the autonomous traveling work apparatus10includes the passive rotary cutter250, the fixed cutter270, and the driving rotary cutter230. The passive rotary cutter250is rotatably supported on the side portion of the vehicle body12, and has a plurality of blade parts254on the outer peripheral portion thereof. The rotation center of the passive rotary cutter250is oriented in the vehicle width direction (one of the horizontal directions) intersecting (orthogonal to) the front-rear direction of the vehicle body12. As the autonomous traveling work apparatus10travels, the passive rotary cutter250passively rotates in response to the passive rotary cutter250receiving the ground reaction force. The fixed cutter270is disposed on the side portion of the vehicle body12, and faces the outer peripheral portion of the passive rotary cutter250. The fixed cutter270does not rotate. The driving rotary cutter230is supported on the side portion of the vehicle body12, has a rotation center oriented in the horizontal direction, and rotates by means of the rotation motor112. In the above-described configuration, above the lower end of the passive rotary cutter250, the driving rotary cutter230cuts the lawn located at the edge of the lawn surface Gr.

In this manner, when edging is performed by the autonomous traveling work apparatus10, a portion of the lawn that is near the ground is cut by the fixed cutter270and the passive rotary cutter250. The driving rotary cutter230cuts the other portion of the lawn, above the lower end of the passive rotary cutter250. Therefore, the driving rotary cutter230is prevented from coming into contact with the ground. Thus, wear of the driving rotary cutter230is suppressed. As a result, the replacement frequency of the driving rotary cutter230is reduced, so that the running cost of the autonomous traveling work apparatus10can be reduced.

The blade body274of the fixed cutter270and the blade part254of the passive rotary cutter250form the shearing region SS therebetween. That is, a portion of the lawn that is near the ground is sheared in the shearing region SS. On the other hand, the driving rotary cutter230cuts the other portion of the lawn, above the shearing region SS. This further prevents the driving rotary cutter230from coming into contact with the ground. Therefore, wear of the driving rotary cutter230is further suppressed.

The work unit50includes the coil spring190that elastically biases the fixed cutter270toward the passive rotary cutter250or the shearing region SS. That is, the fixed cutter270is pressed toward the passive rotary cutter250by the coil spring190. Therefore, the lawn can be reliably pinched between the blade body274of the fixed cutter270and the blade part254of the passive rotary cutter250. As a result, edging (shearing) of the lawn by the fixed cutter270and the passive rotary cutter250is facilitated.

The driving rotary cutter230includes the rotating body232which rotates by means of the rotation motor112, and the blade234which is supported on the outer peripheral portion of the rotating body232in a relatively rotatable manner.

For example, the blade234may come into contact with a fence or the like. In this case, since a load acts on the blade234, there is a concern that the blade234may be damaged. However, in the present embodiment, the blade234is supported on the rotating body232in a relatively rotatable manner. Therefore, when a predetermined load or more is applied to the blade234, the blade234rotates relative to the rotating body232. Since the load is absorbed by the relative rotation, breakage of the blade234due to the load is avoided.

The driving rotary cutter230is disposed inward of the passive rotary cutter250in the vehicle width direction.

According to this configuration, the driving rotary cutter230is protected by the passive rotary cutter250. For example, foreign matter such as flying stones is unlikely to come into contact with the driving rotary cutter230. Further, the driving rotary cutter230is further prevented from coming into contact with the ground. Therefore, breakage or wear of the driving rotary cutter230is further suppressed.

The autonomous traveling work apparatus10includes the moving device100that moves the work unit50in the up-down direction.

By moving the work unit50in the up-down direction with the moving device100, the mowing height of the lawn can be adjusted.

The work unit50includes the support section60that supports the fixed cutter270, the passive rotary cutter250, the driving rotary cutter230, and the drive device210. The support section60can be moved in the up-down direction by the moving device100. On the other hand, the vehicle body12includes the bracket26. The second engaging portion72provided on the support section60engages with the first engaging portion30of the bracket26so as to be movable in the up-down direction.

When the support section60moves in the up-down direction, the second engaging portion72provided on the support section60is guided by the first engaging portion30of the bracket26. Therefore, the support section60or the cutting section200(the work unit50) is prevented from being displaced with respect to the vehicle body12.

The rotation center of the driving rotary cutter230and the rotation center of the passive rotary cutter250are located on the same axis.

According to this configuration, the passive rotary cutter250and the driving rotary cutter230are aligned easily. In the above embodiment, the rotation center of the driving rotary cutter230and the rotation center of the passive rotary cutter250are the rotation shaft214.

The drive device210includes the rotation shaft214supporting the driving rotary cutter230. The passive rotary cutter250is supported by the rotation shaft214via the first bearing142.

Thus, when the rotation shaft214rotates and the driving rotary cutter230rotates, the first bearing142prevents the passive rotary cutter250from following the rotation and rotating. Therefore, it is possible to prevent the passive rotary cutter250from rotating following the rotation shaft214while aligning the driving rotary cutter230and the passive rotary cutter250with respect to the rotation shaft214. As described above, the passive rotary cutter250rotates by receiving the ground reaction force when the autonomous traveling work apparatus10travels.

The work unit50includes the first holding member62holding the drive device210, and the second holding member64holding the fixed cutter270. The first holding member62and the second holding member64are connected to each other. In this configuration, the rotation shaft214is supported by the second holding member64via the second bearing166.

Since the rotation shaft214is held by the second holding member64, the passive rotary cutter250and the fixed cutter270are aligned easily. In addition, the second bearing166is interposed between the rotation shaft214and the second holding member64. Therefore, when the rotation shaft214and the driving rotary cutter230rotate, the second holding member64and the fixed cutter270are prevented from following the rotation and rotating. In the above-described embodiment, the first holding member62and the second holding member64constitute the support section60.

The driving rotary cutter230, the passive rotary cutter250, and the fixed cutter270are disposed between the first holding member62and the second holding member64. Specifically, the driving rotary cutter230, the passive rotary cutter250, and the fixed cutter270are located in the clearance CL formed between the first vertical wall portion70of the first holding member62and the second vertical wall portion78of the second holding member64.

As a result, the driving rotary cutter230, the passive rotary cutter250, and the fixed cutter270are protected by the first holding member62and the second holding member64. For example, contact of foreign matter such as flying stones with the driving rotary cutter230, the passive rotary cutter250, or the fixed cutter270is avoided.

The center of gravity22G of the battery22mounted on the vehicle body12is shifted from the center line L of the vehicle body12in the left-right direction (the vehicle-width direction) toward the right side portion of the vehicle body12. The right side portion is a side portion located on the opposite side to the left side portion where the work unit50is provided.

According to this configuration, the weight of the vehicle body12can be balanced in the left-right direction by the work unit50and the battery22. Therefore, the autonomous traveling work apparatus10is unlikely to fall down during autonomous traveling.

The following notes (appendices) are further disclosed in relation to the above-described embodiment.

The autonomous traveling work apparatus (10) includes: the traveling wheel (14) provided on the vehicle body (12); the control unit (20) configured to control the traveling wheel; and the work unit (50) configured to mow vegetation. The work unit includes the passive rotary cutter (250) configured to passively rotate, the driving rotary cutter (230) configured to be driven to rotate, and the fixed cutter (270) configured not to rotate. The passive rotary cutter is rotatably supported on the side portion of the vehicle body, has the rotation center oriented in the direction intersecting the front-rear direction of the vehicle body, and includes the plurality of blade parts (254) on the outer peripheral portion of the passive rotary cutter. The fixed cutter is disposed on the side portion of the vehicle body and faces the outer peripheral portion of the passive rotary cutter. The driving rotary cutter is supported on the side portion of the vehicle body, has the rotation center oriented in the direction intersecting the front-rear direction, and is configured to rotate by means of the drive device (210). In the above configuration, the driving rotary cutter cuts the vegetation above the lower end of the passive rotary cutter.

When edging of vegetation is performed by the autonomous traveling work apparatus, a portion of the vegetation that is near the ground is cut by the fixed cutter and the passive rotary cutter. The driving rotary cutter cuts the vegetation above the lower end of the passive rotary cutter. Therefore, the driving rotary cutter is prevented from coming into contact with the ground. Accordingly, wear of the driving rotary cutter is suppressed.

As a result, the replacement frequency of the driving rotary cutter is reduced, so that the running cost of the autonomous traveling work apparatus can be reduced.

In the autonomous traveling work apparatus according to Appendix 1, the fixed cutter and each of the blade parts may form the shearing region (SS) in which the vegetation is pinched and sheared between the fixed cutter and the blade part, and the driving rotary cutter may cut the vegetation above the shearing region.

A portion of the vegetation that is near the ground is sheared in the shearing region. The vegetation can be easily mowed by the shearing action. The driving rotary cutter cuts the vegetation above the shearing region. This further prevents the driving rotary cutter from coming into contact with the ground.

In the autonomous traveling work apparatus according to Appendix 1 or 2, the work unit may include the elastic member (190) configured to elastically bias the fixed cutter toward the passive rotary cutter.

The vegetation can be reliably pinched between the passive rotary cutter and the fixed cutter elastically biased toward the passive rotary cutter. Therefore, it becomes easy to mow the vegetation.

In the autonomous traveling work apparatus according to any one of Appendices 1 to 3, the driving rotary cutter may include the rotating body (232) configured to rotate by means of the drive device, and the blade (234) that is supported on the outer peripheral portion of the rotating body in a relatively rotatable manner.

When a predetermined load or more is applied to the blade, the blade rotates relative to the rotating body. Since the load is absorbed by this rotation, breakage of the blade due to the load is avoided.

In the autonomous traveling work apparatus according to any one of Appendices 1 to 4, the driving rotary cutter may be disposed inward of the passive rotary cutter in the width direction of the vehicle body.

According to this configuration, the driving rotary cutter is protected by the passive rotary cutter. Therefore, breakage or wear of the driving rotary cutter is further suppressed.

The autonomous traveling work apparatus according to any one of Appendices 1 to 5 may include the moving device (100) configured to move the work unit in the up-down direction.

By moving the work unit in the up-down direction, the mowing height of the vegetation can be adjusted.

In the autonomous traveling work apparatus according to Appendix 6, the work unit may include the support section (60) that is configured to support the fixed cutter, the passive rotary cutter, the driving rotary cutter, and the drive device, and is configured to be moved in the up-down direction by the moving device, and the vehicle body may include the bracket (26). The bracket may be provided with the first engaging portion (30), the support section may be provided with the second engaging portion (72), and the second engaging portion may engage with the first engaging portion movably in the up-down direction.

When the support section moves in the up-down direction, the second engaging portion provided on the support section is guided by the first engaging portion of the bracket. Therefore, the work unit is prevented from being displaced with respect to the vehicle body.

In the autonomous traveling work apparatus according to any one of Appendices 1 to 7, the rotation center of the driving rotary cutter and the rotation center of the passive rotary cutter may be located on the same axis.

In this case, the passive rotary cutter and the driving rotary cutter are aligned easily.

In the autonomous traveling work apparatus according to Appendix 8, the drive device may include the rotation shaft (214) configured to support the driving rotary cutter, and the passive rotary cutter may be supported by the rotation shaft via the first bearing (142).

In this configuration, the rotation shaft can serve as the rotation center of the driving rotary cutter and the rotation center of the passive rotary cutter. Thus, when the rotation shaft rotates and the driving rotary cutter rotates, the first bearing prevents the passive rotary cutter from following the rotation and rotating.

In the autonomous traveling work apparatus according to Appendix 9, the work unit may include the first holding member (62) holding the drive device, and the second holding member (64) holding the fixed cutter, the first holding member and the second holding member may be connected to each other, and the rotation shaft may be supported by the second holding member via the second bearing (116).

Since the rotation shaft is supported by the second holding member holding the fixed cutter, the passive rotary cutter and the fixed cutter are aligned easily. When the rotation shaft rotates and the driving rotary cutter rotates, the second bearing prevents the second holding member and the fixed cutter from following the rotation and rotating.

In the autonomous traveling work apparatus according to Appendix 10, the driving rotary cutter, the passive rotary cutter, and the fixed cutter may be disposed between the first holding member and the second holding member.

The driving rotary cutter, the passive rotary cutter, and the fixed cutter can be protected by the first holding member and the second holding member.

The autonomous traveling work apparatus according to any one of Appendices 1 to 11 may include the battery (22) mounted on the vehicle body. In this case, the center of gravity (22G) of the battery may be shifted from the center (L) of the vehicle body in the left-right direction toward the side portion of the vehicle body that is located on the opposite side to the side portion where the work unit is provided.

According to this configuration, the weight of the vehicle body can be balanced in the left-right direction by the work unit and the battery. Therefore, the autonomous traveling work apparatus is unlikely to fall down.

The present invention is not limited to the above disclosure, and various modifications are possible without departing from the essence and gist of the present invention.