Lawn mower

Abstract

To provide a mower capable of enhancing propulsion power when traveling along a slope.SOLUTION: A mower has: a mower body part having a movement mechanism; cutting blades provided rotatably on the mower body part; a sensor provided on the mower body part, for detecting inclination of the mower body part; and a controller for changing at least either of rotational speeds and rotative directions of the cutting blades when the inclination of the mower body part is larger than a first threshold, based on inclination information detected by the sensor.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a lawn mower.

Background Art

[0002] Patent Document 1 discloses an automatic lawn mower that mows grass while traveling along a preset path.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a lawn mower that mows grass while traveling, the resistance of the grass increases when traveling on an inclined surface, and there is a risk that the propulsion force decreases. Since this point is not considered in the above Patent Document 1, there is room for improvement.

[0005] An object of the present invention is to provide a lawn mower capable of increasing the propulsion force when traveling on an inclined surface in consideration of the above facts.

Means for Solving the Problems

[0006] The lawn mower according to claim 1 includes a lawn mower main body provided with a moving mechanism, a cutting blade rotatably provided on the lawn mower main body, a sensor provided on the lawn mower main body for detecting the inclination of the lawn mower main body, and based on the inclination information detected by the sensor, when the inclination of the lawn mower main body is greater than a first threshold value, , having a first cutting blade and a second cutting blade arranged side by side in the width direction of the lawn mower main body a controller. Control so that the rotation directions of the first cutting blade and the second cutting blade are opposite to each other And having. Claim 2 The lawn mower according to the above includes a lawn mower main body provided with a moving mechanism, a cutting blade rotatably provided on the lawn mower main body, , having a first cutting blade and a second cutting blade arranged side by side in the vertical direction of the lawn mower main bodyA cutting blade, a sensor provided on the lawn mower main body for detecting the inclination of the lawn mower main body, and based on the inclination information detected by the sensor, when the inclination of the lawn mower main body is greater than a first threshold value, Change so that the rotational speed of the lower first cutting blade is faster than the rotational speed of the upper second cutting blade a controller, and the lawn mower has these components. Claim 3 The lawn mower according to [claim number] includes a lawn mower main body provided with a moving mechanism, and a cutting blade rotatably provided on the lawn mower main body , having a first cutting blade and a second cutting blade arranged side by side in the front-rear direction of the lawn mower main body A cutting blade, a sensor provided on the lawn mower main body for detecting the inclination of the lawn mower main body, and based on the inclination information detected by the sensor, when the inclination of the lawn mower main body is greater than a first threshold value, Change so that the rotational speed of the first cutting blade on the front side in the traveling direction is faster than the rotational speed of the second cutting blade on the rear side a controller, and the lawn mower has these components.

[0007] Claim 1 ~Each claim of claim 3 In the lawn mower according to claim 1, it has a lawn mower main body provided with a moving mechanism and a cutting blade rotatably provided on the lawn mower main body. Thus, while moving by the moving mechanism, grass cutting can be performed by the rotating cutting blade.

[0008] Here, when cutting grass while going up a slope, the load on the rear side in the direction exactly opposite to the traveling direction increases due to the self - weight of the lawn mower. Therefore, depending on the growth state of the grass on the slope, the resistance of the grass may increase due to the disharmony between the rotational speed and direction of the cutting blade, and the propulsion force may decrease.

[0009] In contrast, In the lawn mower according to claim 1, the cutting blades have a first cutting blade and a second cutting blade arranged side by side in the width direction of the lawn mower main body, a sensor for detecting the inclination of the lawn mower main body is provided on the lawn mower main body, and the controller, based on the inclination information detected by the sensor, when the inclination of the lawn mower main body is greater than a first threshold value, サが Thus, Control so that the rotation directions of the first cutting blade and the second cutting blade are opposite to each other. By this, Even in an area where the growth direction of the stems is inclined with respect to the ground surface, by cutting the grass from two directions, the resistance of the grass during cutting and the remaining uncut grass can be effectively suppressed .

[0015] Also, Claim 2 In the lawn mower according to [claim number], The cutting blades have a first cutting blade and a second cutting blade arranged side by side in the vertical direction of the lawn mower main body. A sensor for detecting the inclination of the lawn mower main body is provided on the lawn mower main body. Based on the inclination information detected by the sensor, when the inclination of the lawn mower main body is greater than the first threshold value, the controller changes the rotational speed of the lower first cutting blade to be faster than the rotational speed of the upper second cutting blade. Here, generally, since the diameter of the grass stem becomes larger toward the root, by increasing the rotational speed of the lower - side first cutting blade, the resistance of the grass during cutting can be suppressed.

[0017] Also, Claim 3 In the lawn mower according to this claim, The cutting blades have a first cutting blade and a second cutting blade arranged side by side in the front-rear direction of the lawn mower main body. A sensor for detecting the inclination of the lawn mower main body is provided on the lawn mower main body. Based on the inclination information detected by the sensor, when the inclination of the lawn mower main body is greater than the first threshold value, the controller changes the rotational speed of the first cutting blade on the front side in the traveling direction to be faster than the rotational speed of the second cutting blade on the rear side. By increasing the rotational speed of the cutting blade on the front side in the traveling direction where a large amount of grass is cut, it is possible to effectively suppress the resistance of the grass and the remaining uncut grass during cutting.

[0018] Claim 4 The lawn mower according to this claim is configured as described in any one of Claims 1 to Claim 3 In this configuration, when the inclination of the lawn mower main body is greater than a second threshold value that is greater than the first threshold value, the rotation of the cutting blade is stopped Cause .

[0019] Claim 4 In the lawn mower according to this claim, when the lawn mower main body tilts more than the second threshold value, the rotation of the cutting blade Is stops. As a result, when the lawn mower main body rolls over on an inclined surface or when a rollover is predicted, it is possible to prevent secondary accidents caused by the rotating cutting blade.

Effect of the Invention

[0020] As described above, the lawn mower according to the present invention has an excellent effect of being able to increase the propulsion force when traveling on an inclined surface.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0022] Hereinafter, with reference to FIGS. 1 to 10, the lawn mower 10 according to the present embodiment will be described. The arrow FR appropriately shown in each figure indicates the front side in the front-rear direction of the lawn mower 10, the arrow UP indicates the upper side in the vertical direction, and the arrow RH indicates the right side in the left-right direction (width direction). In addition, when the front-rear, up-down, and left-right directions are used without special mention in the following description, they indicate the front-rear in the front-rear direction of the lawn mower 10, the up-down in the vertical direction, and the left-right when facing the traveling direction.

[0023] As shown in FIGS. 1 and 2, the lawn mower 10 of the present embodiment mainly includes a main body portion 12, a cutting blade unit 14, and a control unit 16. The main body portion 12 corresponds to the "lawn mower main body portion" in the present invention.

[0024] (Main body portion 12) The main body portion 12 is formed in a substantially rectangular parallelepiped shape with the lower side open, and a crawler portion 18 as a moving mechanism is provided on the main body portion 12. The crawler portion 18 is provided on both the left and right sides at the front end portion and both the left and right sides at the rear end portion of the main body portion 12.

[0025] Each crawler unit 18 includes a rubber crawler 18A, a drive wheel 18B, a first idler wheel 18C, and a second idler wheel 18D. The rubber crawler 18A is formed in an endless belt shape and is wound around the drive wheel 18B, the first idler wheel 18C, and the second idler wheel 18D.

[0026] The drive wheel 18B is connected to a drive motor 35 (see FIG. 3) disposed inside the main body 12 via a rotation shaft (not shown). The drive motor 35 is configured to be supplied with power from a battery (not shown). By supplying power to operate the drive motor 35, the drive wheel 18B rotates and the rubber crawler 18A moves in a circulating manner in one direction.

[0027] The first idler wheel 18C is disposed in front of and below the drive wheel 18B and is rotatably attached to a rotation shaft (not shown) extending in the left-right direction. The first idler wheel 18C rotates following the movement of the rubber crawler 18A. The second idler wheel 18D is disposed behind the first idler wheel 18C and is rotatably attached to a rotation shaft (not shown) extending in the left-right direction. The second idler wheel 18D rotates following the movement of the rubber crawler 18A.

[0028] Here, the drive motors 35 are provided independently for each of the four crawler units 18. By controlling the four drive motors 35, the lawn mower 10 can be moved in an arbitrary direction. In FIG. 3, for convenience of explanation, the four drive motors 35 are shown together.

[0029] A cover 20 is provided on the front surface of the main body 12. The cover 20 is a substantially flat plate-shaped member with the front-rear direction as the plate thickness direction and extends in the vertical and horizontal directions. The lower end of the cover 20 is located below the lower end of the main body 12, and the gap between the main body 12 and the ground is narrowed by the cover 20. The cover 20 prevents foreign objects such as stones from entering the cutting blade unit 14 described later.

[0030] In addition, in this embodiment, as an example, the cover 20 is provided only on the front surface of the main body 12, but it is not limited to this. For example, similar covers 20 may also be provided on the rear surface and side surfaces of the main body 12. Further, members for preventing the entry of foreign matters may be provided on both side surfaces of the main body 12 in the same manner as the cover 20.

[0031] (Cutting blade unit 14) As shown in FIG. 2, a cutting blade unit 14 is provided on the main body 12. The cutting blade unit 14 includes two cutting blades consisting of a first cutting blade 22A and a second cutting blade 22B, two rotating shafts 26 for rotating these cutting blades, and two cutting blade motors 28. The first cutting blade 22A and the second cutting blade 22B are arranged side by side in the width direction (left - right direction) of the main body 12. Further, a part of the outer peripheral portions of the first cutting blade 22A and the second cutting blade 22B are arranged so as to overlap in the vertical direction on the center side in the width direction of the main body 12.

[0032] The first cutting blade 22A and the second cutting blade 22B each include a single rotating member 23 and a plurality of tips 24. The rotating member 23 is formed in a disc shape with the vertical direction as the plate thickness direction, and is disposed in the vicinity of the lower opening 12A of the main body 12. The rotating members 23 of the first cutting blade 22A and the second cutting blade 22B are arranged on substantially the same horizontal plane with a space provided in the left - right direction. Each rotating member 23 is fixed to a rotating shaft 26 described later, and is configured to be rotatable with respect to the main body 12 together with the rotating shaft 26.

[0033] A plurality of tips 24 are provided on the rotating member 23. The tips 24 are attached to the outer peripheral end portion of the rotating member 23. In this embodiment, as an example, four tips 24 are provided at equal intervals along the circumferential direction of the rotating member 23.

[0034] Each tip 24 is formed of a thin - walled metal member with the vertical direction as the plate thickness direction, and is configured to be able to cut grass.

[0035] As shown in FIG. 3, in the present embodiment, the tip 24 of the first cutting blade 22A provided on the right side of the main body 12 is attached to the lower surface side of the rotating member 23. On the other hand, the tip 24 of the second cutting blade 22B provided on the left side of the main body 12 is attached to the upper surface side of the rotating member 23. As a result, the tip 24 of the first cutting blade 22A is disposed on the lower side than the tip 24 of the second cutting blade 22B, and the tip 24 of the first cutting blade 22A and the tip 24 of the second cutting blade 22B overlap in the vertical direction.

[0036] The two rotating shafts 26 are arranged side by side in the width direction of the main body 12. The rotating shaft 26 extends in the vertical direction, and the rotating member 23 is attached to the lower end portion of the rotating shaft 26. Further, the upper end portion of the rotating shaft 26 is connected to the cutting blade motor 28.

[0037] The two cutting blade motors 28 are attached to the upper portion of the main body 12 and are arranged side by side in the width direction. The cutting blade motor 28 is driven by being supplied with power from a battery (not shown) provided in the main body 12. Further, the cutting blade motor 28 includes an output shaft (not shown), and the output shaft and the rotating shaft 26 are connected via a gear or a pulley (not shown) or the like. For this reason, when the cutting blade motor 28 is driven, a rotational force is transmitted to the rotating member 23 via the rotating shaft 26, and the rotating member 23 rotates in one direction about the rotating shaft 26.

[0038] As shown in FIGS. 1 and 2, the control unit 16 is provided on the upper surface of the main body 12 and includes a substantially rectangular parallelepiped housing 16A.

[0039] A GPS (Global Positioning System) device 32 is attached to the upper surface of the housing 16A. The GPS device 32 is a device that measures the current position of the lawn mower 10 and includes an antenna (not shown) that receives signals from GPS satellites.

[0040] A camera unit 34 as an imaging device is attached to the front of the housing 16A. The camera unit 34 is a unit configured by combining a plurality of cameras and can image the surrounding situation including the traveling direction of the lawn mower 10. Further, a controller 36 is provided in the control unit 16.

[0041] (Hardware Configuration of Lawn Mower 10) FIG. 4 is a block diagram showing the hardware configuration of the lawn mower 10. As shown in this FIG. 4, the controller 36 constituting the lawn mower 10 includes a CPU (Central Processing Unit: processor) 38, a ROM (Read Only Memory) 40, a RAM (Random Access Memory) 42, a storage 44, a communication I / F (communication interface) 46, and an input / output I / F (input / output interface) 48. Each component is connected to be communicable with each other via a bus 49.

[0042] The CPU 38 is a central processing unit that executes various programs and controls each part. That is, the CPU 38 reads a program from the ROM 40 or the storage 44 and executes the program using the RAM 42 as a work area. Further, the CPU 38 performs control of the above components and various arithmetic processes according to the programs recorded in the ROM 40 or the storage 44.

[0043] The ROM 40 stores various programs and various data. The RAM 42 is a non-temporary recording medium that temporarily stores a program or data as a work area. The storage 44 is composed of an HDD (Hard Disk Drive) or an SSD (Solid State Drive) and is a non-temporary recording medium that stores various programs including an operating system and various data. In the present embodiment, an automatic traveling program of the lawn mower 10 and various data are stored in the storage 44.

[0044] The communication I / F 46 is an interface for the lawn mower 10 to communicate with other devices. For example, standards such as CAN (Controller Area Network), Ethernet (registered trademark), LTE (Long Term Evolution), FDDI (Fiber Distributed Data Interface), Wi-Fi (registered trademark) are used.

[0045] The input / output I / F 48 is electrically connected to the GPS device 32, the camera unit 34, the drive motor 35, the cutting blade motor 28, and the sensor 30. The sensor 30 is a sensor that detects the inclination θ (see FIG. 6) of the main body 12 with respect to the horizontal direction. The sensor 30 can be composed of, for example, inertial sensors such as an acceleration sensor or a gyro sensor. The sensor 30 may be composed of a pendulum type inclination sensor or a float type inclination sensor. Then, the controller 36 controls the drive motor 35 based on information such as the surrounding image detected by the camera unit 34 and the current position of the lawn mower 10 acquired by the GPS device 32 to automatically drive the lawn mower 10. Further, the controller 36 can change the rotation speed and rotation direction of the first cutting blade 22A and the second cutting blade 22B by controlling the cutting blade motor 28 based on the inclination information detected by the sensor 30.

[0046] Note that the controller 36 may automatically drive the lawn mower 10 based on the travel plan of the lawn mower 10 acquired from the outside and the remaining amount of a battery (not shown).

[0047] (Functional configuration of the lawn mower 10) The lawn mower 10 realizes various functions using the above hardware resources. The functional configuration realized by the lawn mower 10 will be described with reference to FIG. 5.

[0048] As shown in FIG. 5, the lawn mower 10 is configured to include, as functional components, an inclination information acquisition unit 50, a drive motor control unit 52, and a cutting blade motor control unit 54. Each functional component is realized by the CPU 38 reading and executing a program stored in the ROM 40 or the storage 44.

[0049] The inclination information acquisition unit 50 acquires the inclination information of the main body 12 detected by the sensor 30.

[0050] The drive motor control unit 52 changes the traveling speed of the main body 12 by controlling the output of the drive motor 35 disposed inside the main body 12.

[0051] The cutting blade motor control unit 54 changes the rotation speed and rotation direction of the rotating member 23 by controlling the output of the cutting blade motor 28. That is, the cutting blade motor control unit 54 changes the rotation speed and rotation direction of the first cutting blade 22A and the second cutting blade 22B by controlling the output of the cutting blade motor 28. The cutting blade motor control unit 54 acquires the output of the cutting blade motor 28 corresponding to the inclination information detected by the sensor 30 with reference to a table. Then, it changes to the acquired output value of the cutting blade motor 28.

[0052] In particular, when the inclination θ of the main body 12 detected by the sensor 30 is greater than the first threshold value, the cutting blade motor control unit 54 of the present embodiment controls the first cutting blade 22A and the second cutting blade 22B to rotate in opposite directions as shown in FIG. 7.

[0053] Further, the cutting blade motor control unit 54 is configured to stop the rotation of the first cutting blade 22A and the second cutting blade 22B when the inclination of the main body 12 detected by the sensor 30 is greater than a second threshold value that is greater than the first threshold value.

[0054] (Operation) Next, the operation of the present embodiment will be described.

[0055] (Motor Control Process) FIG. 8 is a flowchart showing an example of the flow of motor control processing by the mower 10. This motor control processing is executed by the CPU 38 reading a program from the ROM 40 or the storage 44 and expanding it in the RAM 42.

[0056] As shown in FIG. 8, in step S100, the CPU 38 acquires the tilt information of the main body 12 detected by the sensor 30.

[0057] In step S101, the CPU 38 determines whether the tilt of the main body 12 is greater than a first threshold value. If it is determined that the tilt of the main body 12 is greater than the first threshold value, the process proceeds to step S102 (Type-A). On the other hand, when the CPU 38 determines that the tilt of the main body 12 is less than or equal to the first threshold value, the motor control processing ends.

[0058] In step S102, the CPU 38 rotates the first cutting blade 22A and the second cutting blade 22B in the reverse direction. Specifically, by the function of the cutting blade motor control unit 54, the rotation directions of the two cutting blade motors 28 are made opposite to each other, thereby rotating the first cutting blade 22A and the second cutting blade 22B in the reverse direction.

[0059] In the example shown in FIG. 7, the first cutting blade 22A provided on the right side of the main body 12 is rotated counterclockwise, and the second cutting blade 22B provided on the left side of the main body 12 is rotated clockwise. That is, the two cutting blades 22A and 22B are rotated inward of the main body 12. Thereby, even for plants with a high grass height, they can be cut by being wound toward the center side of the main body. Also, since the two cutting blades 22A and 22B are arranged so as to overlap in the vertical direction on the center side of the main body 12, the grass passing through the center side of the main body 12 can be surely cut by the two cutting blades 22A and 22B.

[0060] In this step S102, the first cutting blade 22A and the second cutting blade 22B may be rotated in opposite directions outwardly from each other. For example, when the space below the main body 12 provided between the ground surface is small, by rotating the first cutting blade 22A and the second cutting blade 22B in opposite directions outwardly, the grass after cutting can be scattered outside the main body 12 to facilitate securing the travel path.

[0061] In step S105, the CPU 38 determines whether the inclination of the main body 12 is greater than the second threshold value. If it is determined that the inclination of the main body 12 is greater than the second threshold value, the process proceeds to the process of step S106. On the other hand, when the CPU 38 determines that the inclination of the main body 12 is equal to or less than the second threshold value, the process returns to the process of step S101.

[0062] In step S106, the CPU 38 stops the rotation of the first cutting blade 22A and the second cutting blade 22B. Specifically, the rotation of the first cutting blade 22A and the second cutting blade 22B is stopped by stopping the output to the two cutting blade motors 28 by the function of the cutting blade motor control unit 54. This second threshold value is a value larger than the first threshold value and represents the inclination of the main body 12 in a tipping state or an inclination where tipping is predicted. Therefore, when the inclination of the main body 12 is greater than the second threshold value, it is determined that the lawn mower 10 is tipping or is in a state where tipping is likely, and the rotation of the two cutting blades 22A, 22B is stopped for the safety of the surroundings.

[0063] As described above, the lawn mower 10 of the present embodiment has a main body 12 provided with a crawler unit 18 and cutting blades 22A, 22B rotatably provided on the main body 12. Thereby, while moving by the crawler unit 18, the grass can be cut by the rotating cutting blades 22A, 22B.

[0064] Here, FIG. 6 schematically shows the lawn mower 10 climbing an inclined surface. In FIG. 6, the load due to the self-weight of the lawn mower 10 is indicated by an arrow Wg. Also, the component of the component force in the direction parallel to the inclined surface is indicated by an arrow w1, and the component of the component force in the direction perpendicular to the inclined surface is indicated by an arrow w2.

[0065] As shown in this figure, when mowing grass while going up an inclined surface, the component w1 of the component force of the self-weight Wg of the lawn mower 10 increases the load on the rear side directly opposite to the traveling direction. Therefore, depending on the growth state of the grass on the inclined surface, the resistance of the grass may increase due to the disharmony between the rotational speed and the rotational direction of the cutting blades 22A and 22B, and the propulsion force may decrease.

[0066] For example, it is conceivable that the propulsion force decreases because the resistance of the grass during mowing increases due to insufficient rotational speed of the cutting blade. Also, in an area where the growth direction of the stem is inclined with respect to the ground surface, it is conceivable that the propulsion force decreases because the cutting blade does not hit the stem due to the disharmony between the growth direction of the grass and the rotational direction of the cutting blade, resulting in uncut grass remaining.

[0067] On the other hand, when the inclination θ of the main body 12 is greater than the first threshold value based on the inclination information detected by the sensor 30, the controller 36 of the lawn mower 10 changes at least one of the rotational speed and the rotational direction of the cutting blades 22A and 22B. Thereby, the resistance of the grass during mowing and the uncut grass can be suppressed, and the propulsion force when the lawn mower 10 moves on the inclined surface can be increased. Note that the angle θ formed by the arrows Wg and w2 shown in FIG. 6 is equal to the inclination of the main body 12 with respect to the horizontal plane, that is, the inclination angle of the inclined surface.

[0068] Further, in the lawn mower 10, the main body 12 is provided with a first cutting blade 22A and a second cutting blade 22B, and at least one of the rotational speed and the rotational direction of one cutting blade is changed to be different from that of the other cutting blade. Thereby, the movement of mowing can be changed in a complicated manner. Therefore, even when mowing the grass on an inclined surface where various varieties of plants grow, the resistance of the grass during mowing and the uncut grass can be effectively suppressed.

[0069] As an example, in the main body 12 of the lawn mower 10, a first cutting blade 22A and a second cutting blade 22B are arranged side by side in the width direction, and when the main body 12 tilts more than a first threshold value, the two cutting blades are configured to rotate in the reverse direction. Thereby, even in a land where grass grows with its stems tilted with respect to the ground surface, by cutting the grass from two directions, it is possible to effectively suppress the resistance of the grass during cutting and the remaining uncut grass.

[0070] Also, as shown in FIG. 7, by rotating the two cutting blades in the reverse direction toward the inside of the main body 12, it is possible to collect the grass on the central side of the main body 12 and suppress the remaining uncut grass.

[0071] Also, by rotating the two cutting blades in the reverse direction toward the outside of the main body 12, it is possible to scatter the cut grass outside the main body 12 to secure a path and suppress a decrease in the propulsion force.

[0072] Furthermore, in the present embodiment, when the main body 12 tilts more than a second threshold value, the rotation of the cutting blades 22A and 22B is stopped. Thereby, when the main body 12 rolls over on a slope or when a rollover is predicted, it is possible to prevent a secondary accident caused by the rotating cutting blades.

[0073] (First Modification Example) In the above embodiment, the first cutting blade 22A and the second cutting blade 22B are arranged side by side in the width direction of the main body 12, but it is not limited to this. As in the first modification example shown in FIG. 9, the first cutting blade 22A and the second cutting blade 22B may be arranged side by side in the vertical direction of the main body 12. In this first modification example, the first cutting blade 22A is arranged below the second cutting blade 22B. In this case, the rotating shaft 26 that supports the first cutting blade 22A and the rotating shaft 26 that supports the second cutting blade 22B are coaxially arranged at the central portion of the main body 12.

[0074] In the configuration where the first cutting blade 22A and the second cutting blade 22B are arranged in the vertical direction as described above, when the CPU 38 determines in step S101 shown in FIG. 8 that the tilt of the main body 12 is greater than the first threshold value, the process proceeds to the process of step S103 (Type - B).

[0075] At step S103, the CPU 28 changes the rotational speed of the lower first cutting blade 22A to be faster than that of the upper second cutting blade 22B. Specifically, the CPU 38 increases the output of the cutting blade motor 28 of the first cutting blade 22A by means of the function of the cutting blade motor control unit 54, thereby increasing the rotational speed of the first cutting blade 22A to rotate faster than the second cutting blade 22B.

[0076] Here, generally, since the diameter of the grass stem becomes larger as it goes towards the root, by increasing the rotational speed of the lower first cutting blade 22A, the resistance of the grass during cutting can be suppressed. Thereby, the propulsion force of the lawn mower 1 is improved. Since the processing of steps S105 to S106 in FIG. 8 is the same as that in the above embodiment, the description thereof is omitted.

[0077] (Second modification example) As in the second modification example shown in FIG. 10, the first cutting blade 22A and the second cutting blade 22B may be arranged side by side in the front-rear direction of the main body 12. In this second modification example, the first cutting blade 22A is arranged on the front side of the main body 12 with respect to the second cutting blade 22B. In this case, the rotary shaft 26 that supports the first cutting blade 22A and the rotary shaft 26 that supports the second cutting blade 22B are arranged at intervals in the front-rear direction at the central portion of the main body 12.

[0078] In the configuration in which the first cutting blade 22A and the second cutting blade 22B are arranged in the front-rear direction as described above, when the CPU 38 determines in step S101 shown in FIG. 8 that the inclination of the main body 12 is greater than the first threshold value, the process proceeds to the process of step S104 (Type-C).

[0079] In step S104, the CPU 28 changes the rotational speed of one of the cutting blades 22 (22A, 22B) located on the front side in the traveling direction of the main body 12 to be faster than that of the other cutting blade 22 (22A, 22B). Specifically, the CPU 38 increases the output of the cutting blade motor 28 of one of the cutting blades 22 (22A, 22B) located on the front side in the traveling direction by the function of the cutting blade motor control unit 54, thereby increasing the rotational speed of the cutting blade 22 (22A, 22B) and rotating it faster than the other cutting blade 22 (22A, 22B). Thereby, by increasing the rotational speed of the cutting blade on the front side in the traveling direction where the amount of grass cut is large, the resistance of the grass during cutting and the remaining uncut grass can be effectively suppressed, so that the propulsion force of the lawn mower 1 is improved.

[0080] Since the processing of steps S105 to S106 in FIG. 8 is the same as that in the above embodiment, the description thereof is omitted.

[0081] In the above embodiment and each modification, the configuration in which two cutting blades 22A and 22B are provided on the main body 12 has been described. However, As a reference example that is not an embodiment of the present invention, There may be only one cutting blade provided on the main body 12. In this case, the rotational speed or the rotational direction of the cutting blade may be changed periodically or irregularly.

[0082] Further, a configuration in which three or more cutting blades are provided on the main body 12 may also be adopted. For example, two cutting blades arranged in the width direction of the main body 12 and two cutting blades arranged in the front-rear direction of the main body 12 may be provided. Alternatively, two cutting blade units arranged in the width direction of the main body may be provided, and each cutting blade unit may be configured to include two cutting blades arranged vertically. In such a case, according to the number of cutting blades, a configuration may be adopted in which the processes of steps S102 (Type-A), S103 (Type-B), and S104 (Type-C) in FIG. 8 are combined and performed simultaneously.

[0083] Note that, in each of the above embodiments, the processes executed by the CPU by reading software (programs) may be executed by various processors other than the CPU. Examples of processors in this case include PLDs (Programmable Logic Devices) whose circuit configurations can be changed after manufacture, such as FPGAs (Field-Programmable Gate Arrays), and dedicated electric circuits such as ASICs (Application Specific Integrated Circuits) that have circuit configurations designed specifically to execute specific processes. Also, each process may be executed by one of these various processors, or may be executed by a combination of two or more processors of the same type or different types (for example, a plurality of FPGAs, and combinations of a CPU and an FPGA, etc.). Further, the hardware structure of these various processors is, more specifically, an electric circuit formed by combining circuit elements such as semiconductor elements. Also, in each of the above embodiments, the configuration is such that various programs and data are stored in the storage 44, but the present invention is not limited to this. These programs and data may be provided in a form recorded on non-transitory recording media such as CD-ROMs (Compact Disk Read Only Memories), DVD-ROMs (Digital Versatile Disk Read Only Memories), and USB (Universal Serial Bus) memories. Also, these programs and data may be in a form downloaded from an external device via a network.

Explanation of Reference Numerals

[0084] 10 Lawn mower 12 Main body (main body of the lawn mower) 18 Crawler section (travel mechanism) 22A First cutting blade (cutting blade) 22B Second cutting blade (cutting blade) 36 Controller

Claims

1. A lawn mower body provided with a moving mechanism, a cutting blade rotatably provided on the lawn mower body and having a first cutting blade and a second cutting blade arranged side by side in the width direction of the lawn mower body, a sensor provided on the lawn mower body for detecting the inclination of the lawn mower body, and a controller for controlling the rotation directions of the first cutting blade and the second cutting blade to be opposite to each other when the inclination of the lawn mower body is greater than a first threshold value based on the inclination information detected by the sensor. A lawn mower having the above.

2. A lawn mower body provided with a moving mechanism, a cutting blade rotatably provided on the lawn mower body and having a first cutting blade and a second cutting blade arranged one above the other in the vertical direction of the lawn mower body, a sensor provided on the lawn mower body for detecting the inclination of the lawn mower body, and a controller for changing the rotation speed of the lower first cutting blade to be faster than the rotation speed of the upper second cutting blade when the inclination of the lawn mower body is greater than a first threshold value based on the inclination information detected by the sensor. A lawn mower having the above.

3. A lawn mower body provided with a moving mechanism, a cutting blade rotatably provided on the lawn mower body and having a first cutting blade and a second cutting blade arranged side by side in the front-rear direction of the lawn mower body, a sensor provided on the lawn mower body for detecting the inclination of the lawn mower body, and a controller for changing the rotation speed of the first cutting blade on the front side in the traveling direction to be faster than the rotation speed of the second cutting blade on the rear side when the inclination of the lawn mower body is greater than a first threshold value based on the inclination information detected by the sensor. A lawn mower having the above.

4. The lawn mower according to any one of Claims 1 to 3, wherein the controller stops the rotation of the cutting blade when the inclination of the lawn mower body is greater than a second threshold value that is greater than the first threshold value.

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