Lawn mower

Abstract

To provide a mower that enables even an operator inexperienced in mowing operation to prevent grass clogging in a grass transport path to a grass collection container.SOLUTION: A mower for performing mowing operation while traveling in a field comprises a grass clogging prevention unit that calculates a grass clogging index using the following formula from information on a work speed, a current grass height, a cutting height, and a grass density that are input from an input device and information on a work width of a mowing device input from the input device or stored in a storage device; when the grass clogging index is equal to or larger than a predetermined value, adds / subtracts a numerical value of at least one of the cutting height, the work speed, and the work width to calculate a modified work condition plan in which the calculated grass clogging index is modified so as to be smaller than the predetermined value, and makes the calculated modified work condition plan be displayed on a display unit, where the grass clogging index=the work width×the work speed×(the current grass height-the cutting height)×the grass density.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a lawn mower that performs lawn mowing work.

Background Art

[0002] Conventionally, a lawn mower that performs lawn mowing work while traveling on a field or the like is known.

[0003] For example, Patent Document 1 discloses a lawn mower that performs lawn mowing work with a lawn mowing device and conveys the cut grass to a grass collection container provided on the machine body.

[0004] In this lawn mower, based on the weather in the past 12 hours and the current humidity, clogging of grass in the conveyance path to the grass collection container is predicted, and the recommended working speed is configured to be displayed on a monitor provided on the machine body.

[0005] Therefore, even when the grass is wet, the operator can reduce the amount of grass passing through the conveyance path to the grass collection container per unit time by suppressing the vehicle speed during lawn mowing work to the recommended working speed, and can suppress clogging of grass in the conveyance path.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, even when the humidity is low, clogging of the conveyance path to the grass collection container occurs. Therefore, it is not easy to predict clogging of the conveyance path based only on weather and humidity information. Experienced operators can adjust the amount of grass passing through the conveyance path per unit time and suppress clogging by increasing the overlap margin of the working width or reducing the working speed based on the state and height of the grass. However, beginners without such rules of thumb may frequently cause clogging.

[0008] Therefore, an object of the present invention is to provide a lawn mower that can suppress clogging of the conveyance path to the grass collection container even for operators unaccustomed to mowing work.

Means for Solving the Problems

[0009] This object of the present invention is A lawn mower that performs mowing work while traveling in a field, A traveling vehicle body, A mowing device attached to the traveling vehicle body, A grass collection container that stores the grass cut by the mowing device, A conveyance path extending from the mowing device to the grass collection container, An input device for inputting various working conditions, A display unit capable of displaying various information, And a control unit that controls the display of the display unit, The control unit includes a clogging prevention unit that suppresses clogging in the conveyance path and a storage device that stores various information, The input device accepts input of the working speed indicating the vehicle speed during mowing work, the current grass height which is the grass height before mowing work, the cutting height which is the target height after mowing work, and information on the density of the grass for which mowing work is to be performed. The clogging prevention unit calculates a clogging index using the following formula from the information on the working speed, current grass height, cutting height, and grass density input from the input device, and the information on the working width of the grass cutting device input from the input device or stored in the storage device. When the calculated clogging index is equal to or greater than a predetermined value, at least one numerical value among the cutting height, working speed, and working width is added or subtracted to calculate a modified working condition plan that modifies the calculated clogging index to be less than the predetermined value, and the calculated modified working condition plan is displayed on the display unit. This is achieved by a lawn mower characterized by this. (Equation 1) Clogging index = working width × working speed × (current grass height - cutting height) × grass density According to the present invention, when the clogging index is equal to or greater than a predetermined value and clogging is likely to occur, the clogging prevention unit adds or subtracts at least one numerical value among the cutting height, working speed, and working width so that the clogging index becomes less than the predetermined value, calculates a modified working condition plan that modifies the clogging index to be less than the predetermined value, and is configured to display it on the display unit. Therefore, it is possible to easily set working conditions in which clogging is less likely to occur. Thus, even an operator who is not used to lawn mowing work can suppress clogging of the conveyance path to the grass collection container.

[0010] In a preferred embodiment of the present invention, When the calculated clogging index is equal to or greater than a predetermined value, in calculating the modified working condition plan, the clogging prevention is configured to preferentially calculate and display on the display unit a modified working condition plan obtained by adding the cutting height among the numerical values of the cutting height, working speed, and working width.

[0011] According to this preferred embodiment of the present invention, since the control unit is configured to preferentially calculate and display a modified working condition plan calculated by adding the cutting height, it is possible to suppress clogging without extending the time required for lawn mowing work, such as when changing the working speed to a lower value or changing the working width to a narrower value, in order to reduce the volume of grass cut per unit time.

[0012] In a more preferred embodiment of the present invention, the control unit includes a vehicle speed suppression unit that warns of an excessive vehicle speed of the traveling vehicle body, the vehicle speed suppression unit is configured to acquire information regarding the vehicle speed of the traveling vehicle body during mowing operation, and when the vehicle speed during mowing operation exceeds the operation speed input and set from the input device, cause a warning to be output to the display unit.

[0013] According to this preferred embodiment of the present invention, when the vehicle speed becomes higher than the set operation speed, the operator is warned, so that the volume of grass cut per unit time can be suppressed and the occurrence of grass clogging can be suppressed.

[0014] In a more preferred embodiment of the present invention, it includes a positioning device that acquires position information of the traveling vehicle body, the control unit has a route calculation unit that calculates a planned travel route including a plurality of straight travel routes formed linearly and turning routes that turn from each straight travel route to an adjacent straight travel route, and an automatic travel unit that automatically travels the traveling vehicle body along the planned travel route calculated by the route calculation unit, the route calculation unit is configured to calculate a planned travel route after teaching travel based on the field shape information acquired by teaching travel by manual driving, and the grass clogging prevention unit is configured to be able to set information on the operation speed, current grass height, cutting height, and grass density input from the input device, and to update the information on the numerical values of the set cutting height, operation speed, and operation width based on the calculated modified operation condition plan by a predetermined operation. Further, when the numerical value of the operation width input and set by the input device is updated and decreased, the route calculation unit corrects the planned travel route calculated after teaching travel to a new planned travel route in which the straight travel routes are narrowed by a predetermined interval.

[0015] According to this preferred embodiment of the present invention, when the numerical value of the working width is input and updated by the input device and decreased based on the modified working condition plan, the route calculation unit is configured to calculate a new planned travel route with a reduced interval between straight travel routes. Therefore, even for a mowing device with a constant mowing width, an overlap margin occurs in the mowing width or the overlap margin increases. As a result, since the volume of grass mowed per unit time by the mowing device decreases, grass clogging can be suppressed.

[0016] In still another preferred embodiment of the present invention, the mowing device is configured to be driven by rotational power output from the engine of the traveling vehicle body, the input device is configured to be able to select, as a method for inputting the density of grass, manual input for inputting a density value and automatic input for reading and inputting pre-stored density information, when the automatic input is selected, information on the density of grass measured based on the magnitude of the load on the engine in the field to be worked is read from the storage device and automatically input, and when the information on the density of grass to be measured is not stored in the storage device, a predetermined value pre-stored in the storage device is read and automatically input.

[0017] According to this preferred embodiment of the present invention, since the density of grass measured based on the magnitude of the load on the engine in the field to be worked can be automatically input when inputting working conditions, the value of the accurate grass clogging index G can be calculated.

[0018] Also, according to this preferred embodiment of the present invention, since a predetermined value pre-stored is automatically input when the density value measured based on the magnitude of the load on the engine is not stored in the storage device, the grass clogging index can be calculated even in a field where the density of grass has never been measured.

[0019] In a further preferred embodiment of the present invention, While the mowing operation is being performed by the automatic driving unit during the automatic driving, the control unit is configured to measure the grass density at a predetermined time interval based on the magnitude of the load on the engine. Each time the grass density is measured, the grass clogging prevention unit calculates a grass clogging index using the newly measured grass density value. When this grass clogging index becomes equal to or greater than a predetermined value, the vehicle speed of the traveling vehicle body is controlled to be low and / or the cutting height is changed to be high until the grass clogging index becomes less than the predetermined value.

[0020] According to this preferred embodiment of the present invention, while performing the mowing operation by automatic driving in the field, the grass density is measured at a predetermined time interval based on the magnitude of the load on the engine, and the grass clogging index is calculated. When the grass clogging index becomes equal to or greater than a predetermined value, the vehicle speed and / or the cutting height are configured to be changed. Therefore, even when the grass density that changes moment by moment during the operation becomes high, the grass clogging index can be maintained less than the predetermined value, and grass clogging can be effectively suppressed.

Advantages of the Invention

[0021] According to the present invention, it is possible to provide a mower that can suppress grass clogging in the conveyance path to the grass collection container even for an operator who is not used to the mowing operation.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0023] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0024] FIG. 1 is a schematic left side view of a lawn mower 1 according to a preferred embodiment of the present invention, and FIG. 2 is a schematic plan view of the lawn mower 1 shown in FIG. 1.

[0025] In this specification, unless otherwise specified, the side in the traveling direction of the lawn mower 1 is referred to as "front", the opposite side is referred to as "rear", the left side toward the front in the traveling direction of the lawn mower 1 is referred to as "left", and the opposite side is referred to as "right".

[0026] The lawn mower 1 includes a traveling vehicle body 2, a grass cutting device 3 attached to the front portion of the traveling vehicle body 2, a grass collection container 4 provided at the rear portion of the traveling vehicle body 2, a conveyance path 8 for cut grass extending from the grass cutting device 3 to the grass collection container 4, a blower 7 for conveying the cut grass cut by the grass cutting device 3 to the grass collection container 4 through the conveyance path 8, a control unit 5 (see FIG. 5) for controlling each device of the machine body, a display unit 13 for displaying various information, and a positioning device 9 for acquiring the position information of the traveling vehicle body 2.

[0027] The traveling vehicle body 2 includes a driver's seat 2e on which an operator sits, a pair of left and right front wheels 2a and a pair of left and right rear wheels 2b, a steering wheel 2c for steering the pair of front wheels 2a, an engine 2d as a power source of the machine body 1, a transmission mechanism 2f (see FIG. 5) that changes the rotational power output from the engine 2d and transmits it to the mowing device 3 and the blower 7, and an operation unit 2n for operating the machine body.

[0028] In the present embodiment, the traveling vehicle body 2 is configured to be capable of not only manual driving in which it travels on a farm field based on the operation of an operator but also automatic driving in which it automatically travels while automatically steering the steering wheel 2c (hereinafter referred to as "automatic driving").

[0029] The pair of left and right rear wheels 2b are rotationally driven by a traveling motor 2g shown in FIG. 5, whereby the traveling vehicle body 2 moves forward.

[0030] The display unit 13 includes a monitor 12 and a mobile terminal 6 arranged in the vicinity of the steering wheel 2c.

[0031] The monitor 12 is configured to be able to display various information based on a video signal output from the control unit 5.

[0032] The mobile terminal 6 is detachably attached to the rear surface of a steering post 2h that supports the steering wheel 2c.

[0033] In the present embodiment, the mobile terminal 6 is configured as a tablet-type computer and includes a touch panel capable of inputting various information. The mobile terminal 6 also has a function as the "input device" of the present invention for inputting the working conditions of the mowing operation.

[0034] The operation unit 2n is provided with a cutting height change switch 2n1 for changing the cutting height by the mowing device 3 and a driving change switch 2n2 for switching between the state of traveling in automatic driving and the state of traveling in manual driving (see FIG. 2).

[0035] FIG. 3 is a schematic perspective view of the mowing device 3.

[0036] The grass cutting device 3 includes a pair of left and right auxiliary wheels 3b disposed at the front thereof, a mower deck 3a including a pair of left and right blades (rotary blades) 3a1 (see FIG. 2), a pair of left and right cutting height cylinders 3g for changing the height position of the mower deck 3a, and a coupler 3e to the traveling vehicle body 2. Each cutting height cylinder 3g is covered by a cylinder cover 3g3.

[0037] Each of the left and right blades 3a1 is rotated by the power output from the engine 2d. When the traveling vehicle body 2 moves forward with the pair of blades 3a1 rotating, the grass in the field can be cut while advancing. The grass cut by the grass cutting device 3 is conveyed in the conveyance path 8 by the blowing of a blower 7 (see FIG. 1) driven by the engine 2d, and is stored in the grass collection container 4.

[0038] In this specification, as shown in FIG. 2, the width in the left - right direction that can be cut when the traveling vehicle body 2 moves forward is referred to as the "blade cutting width", and when the vehicle body 2 moves forward, the left - right width of the overlapping part between the worked area where the grass cutting work has already been performed and the blade cutting width is referred to as the "overlap margin".

[0039] Also, the width in which the grass cutting work is actually performed when moving forward is referred to as the "actual cutting width" or "working width". As shown in FIG. 2, the actual cutting width B is the width obtained by subtracting the overlap margin C from the blade cutting width A. If there is no overlap margin C, the actual cutting width B is equal to the blade cutting width A. When there is an overlap margin C, the actual cutting width B becomes narrower than the blade cutting width A. In this embodiment, the working width (actual cutting width) is configured to be increased or decreased by adjusting the width of the overlap margin C. However, for example, the working width (actual cutting width) may be configured to be changed by changing the left - right interval between the pair of blades 3a1 by a motor or the like.

[0040] Each of the pair of auxiliary wheels 3b is supported by an auxiliary wheel arm 3c, and the left and right auxiliary wheel arms 3c are connected to the mower deck 3a so as to be rotatable about a connection fulcrum 3d. The left and right auxiliary wheel arms 3c are connected to each other by a link mechanism 3f.

[0041] The link mechanism 3f includes a connecting shaft 3f1 extending left and right, and a pair of left and right connectors 3f2 connecting the connecting shaft 3f1 to the auxiliary wheel arm 3c.

[0042] FIG. 4 is an enlarged perspective view of the vicinity of the cutting height cylinder 3g disposed at the right front portion of the mowing device 3. FIG. 4 shows a state in which the cylinder cover 3g3 is removed.

[0043] At the left and right ends of the connecting shaft 3f1, connection bodies 3h each having a substantially figure-nine shape in a longitudinal sectional view are attached, and the rod 3g1 of the cutting height cylinder 3g is inserted into a rectangular gap 3h1 formed in the upper portion of each connection body 3h and attached to the connection body 3h.

[0044] When the left and right rods 3g1 are extended by driving the DC motors 3g2 of the respective cutting height cylinders 3g, the connecting shaft 3f1 integrally with the left and right connection bodies 3h is rotated clockwise in a right side view. As a result, the pair of connectors 3f2 are rotated downward forward about the connecting shaft 3f1, and the pair of auxiliary wheel arms 3c are rotated downward forward.

[0045] Since the pair of auxiliary wheels 3b are in contact with the ground throughout the driving of the DC motor 3g2 before and after, the mower deck 3a is raised by the rotation of the pair of auxiliary wheel arms 3c.

[0046] On the contrary, when the left and right rods 3g1 are contracted by driving the DC motors 3g2 of the respective cutting height cylinders 3g, the connecting shaft 3f1 integrally with the left and right connection bodies 3h is rotated counterclockwise in a right side view. As a result, the pair of connectors 3f2 are rotated upward forward about the connecting shaft 3f1, and the pair of auxiliary wheel arms 3c are rotated upward forward.

[0047] Since the pair of auxiliary wheels 3b are in contact with the ground throughout the driving of the pair of DC motors 3g2 before and after, the mower deck 3a is pushed down and lowered by the rotation of the pair of auxiliary wheel arms 3c.

[0048] In this embodiment, as described above, the height position of the mower deck 3a can be changed by the expansion and contraction of the pair of cutting height cylinders 3g. However, the change in the height position of the mower deck can also be achieved by other mechanisms such as a rack and pinion mechanism. FIG. 5 is a control block diagram of the lawn mower 1 shown in FIG. 1, and FIG. 6 is a schematic plan view showing a planned travel route to be used for automatic operation.

[0049] The control unit 5 includes a vehicle ECU 5a that controls each device of the machine body, and an automatic driving ECU 5b that transmits a control signal to the vehicle ECU 5a during automatic driving.

[0050] The automatic driving ECU 5b includes a storage device 5b1 in which various information such as a planned travel route, field shape information, position information of the vehicle body 2, and working width is stored, a route calculation unit 5b2 that calculates the planned travel route, and an automatic driving unit 5b3 that controls the steering of the front wheels 13 and the travel of the vehicle body 2 during automatic driving to automatically drive the traveling vehicle body 2. The position information of the vehicle body 2 is acquired by a positioning device 9 provided on the upper part of the vehicle body 2.

[0051] The positioning device 9 can amplify the GNSS signal from the GNSS satellite, acquire information on the transmission time of the GNSS signal, and then calculate the position of the traveling vehicle body 2 using the triangulation method.

[0052] Based on the field shape information obtained by the lawn mower 1 making one round of the field based on the operator's operation in so-called teaching travel and the information on the blade cutting width A or the actual cutting width B of the mowing device 3, the route calculation unit 5b2 calculates the planned travel routes R and R' shown in FIG. 6.

[0053] The planned travel route R is a travel route calculated assuming that the actual cutting width B is equal to the blade cutting width A. As shown by the broken line in FIG. 6, the route calculation unit 31 calculates it to include a plurality of straight travel routes R1 formed linearly and turning routes R2 that turn from each straight travel route R1 to an adjacent straight travel route R1.

[0054] On the other hand, as will be described in detail later, the planned travel route R' indicated by the solid line is an example of a newly calculated planned travel route when the actual cutting width B of the mowing device 3 is changed from the blade cutting width A.

[0055] In this embodiment, when mowing work is performed by automatic driving in a field where mowing work is performed for the first time, first, field shape information is acquired by teaching travel, and immediately after a planned travel route R is calculated, work condition input is performed on a work condition input screen (see FIG. 8) displayed on the mobile terminal 6. It is configured to be done.

[0056] The automatic driving unit 5b3 calculates a departure distance, which is the distance between a preset planned travel route and the position of the vehicle body 2 measured by the positioning device 9, and generates steering information so as to steer the steering wheel 2c in a direction to make this departure distance zero, and transmits it to the vehicle ECU 5a. Note that the steering information is the target steering angle that the steering wheel 17 should take.

[0057] When acquiring the steering information from the automatic driving unit 5b3, the vehicle ECU 5a drives the steering motor 2i that rotates the steering wheel 2c based on the detection signal of the encoder 2j that detects the steering angle of the steering wheel 2c and the above steering information.

[0058] The steering motor 2i is driven by an operation amount corresponding to an input pulse signal from the vehicle ECU 5a. As a result, as the steering shaft 21 rotates, a pitman arm (not shown) rotates and the front wheels 2a are steered.

[0059] Furthermore, the vehicle ECU 5a increases or decreases the driving speed of the traveling motor 2g based on information about the target vehicle speed output from the autonomous driving unit 5b3 and the detection signal of the vehicle speed sensor 2k that detects the traveling speed of the traveling vehicle body 2, thereby increasing or decreasing the actual vehicle speed of the vehicle body 2. In the present embodiment, the rear wheels 2b are configured to be rotationally driven by the traveling motor 2g, but the rotational power of the engine 2d may be transmitted to and drive the rear wheels 2b via a transmission mechanism such as an HST.

[0060] In addition, the vehicle ECU 5a drives the throttle motor 2m that adjusts the intake air amount of the engine 2d to increase or decrease the engine speed, controls the transmission mechanism 2f, and can increase or decrease the rotational speed of the rotary blade of the mowing device 3 and the air volume of the blower 7.

[0061] Also, the vehicle ECU 5a is configured to be capable of wireless communication with the mobile terminal 6, and can acquire information input to the mobile terminal 6 by the operator via wireless communication. In addition, the vehicle ECU 5a can transmit various display requests (display instruction signals) to the mobile terminal 6. The storage device of the mobile terminal 6 stores layout information of various display screens, and displays a layout corresponding to various display requests transmitted from the vehicle ECU 5a. In addition, the storage device is configured to be able to add and display information on the working conditions (including information on the modified working condition plan) received together with the display request within the layout of the screen.

[0062] Furthermore, during mowing work by manual driving, the vehicle ECU 5a is configured to display, in real time, an image captured by the rear camera 2r provided at the rear end of the traveling vehicle body 2 on the monitor 12.

[0063] The rear camera 2r is directed downward to the rear and can capture the state of the field after the mowing work has been performed.

[0064] In a conventional mower, when a clogging occurs in the conveying path 8 to the grass collecting container 4, an operator who operates while looking ahead often does not notice that the cut grass is scattered on the field from the mowing device 3 until turning around.

[0065] In contrast, in the present embodiment, since the state of the field behind the vehicle body 2 is projected onto the monitor 12 disposed near the steering wheel 2c, when clogging occurs, the operator can be made to recognize it at an early stage. In addition, the operator can check the mowing tracks by looking at the monitor 12.

[0066] The vehicle ECU 5a includes a storage device 5a1 in which various information such as work conditions including the blade cutting width and database of field shape information are stored, a clogging prevention unit 5a2 that suppresses clogging in the conveyance path 8, a grass density measurement unit 5a3 that measures the grass density of the field, and a vehicle speed suppression unit 5a4 that gives a warning when the vehicle speed is excessive (too high) during manual operation.

[0067] Before starting the grass cutting operation, the clogging prevention unit 5a2 calculates a clogging index indicating the ease of grass clogging in the conveyance path 8 based on the work conditions input to the mobile terminal 6, and proposes a change in the work conditions to the operator when this clogging index is high.

[0068] The grass density measurement unit 5a3 measures the grass density of the field based on the magnitude of the load on the engine 2d.

[0069] For example, during the grass cutting operation, when the grass density increases and the load on the engine 2d increases, in order to maintain the rotational speed of the engine 2d detected by the engine rotation sensor 2d2, the fuel injection amount by the fuel injection device 2d1 in the engine 2d increases.

[0070] Conversely, during the grass cutting operation, when the grass density decreases and the load on the engine 2d decreases, in order to maintain the rotational speed of the engine 2d, the fuel injection amount by the fuel injection device 2d1 in the engine 2d decreases.

[0071] Since the fuel injection amount changes according to the grass density during the grass cutting operation in this way, the grass density measurement unit 5a3 can measure the grass density from the change in the fuel injection amount by the fuel injection device 2d1 caused by the change in the load on the engine.

[0072] Note that it is not always necessary to measure the load of the engine 2d from the fuel injection amount in the engine 2d. For example, a microphone for picking up sound may be arranged near the engine 2d, and the load of the engine may be measured based on the magnitude of the engine sound, and the grass density may be measured.

[0073] In this case, for example, by previously storing in the storage device 5a1 a numerical table in which the relationship between the magnitude of the engine sound representing the engine load and the grass density is recorded, the value of the grass density of the field associated with the actually detected magnitude of the engine sound can be retrieved from the numerical table.

[0074] When the vehicle speed suppression unit 5a4 is set to manual operation by the operation changeover switch 2n2 and during the mowing operation, when the vehicle speed of the vehicle body 2 detected by the vehicle speed sensor 2k exceeds the set (more specifically, stored in the storage device 5a1) working speed, a warning is displayed on the monitor 12. At the same time, the vehicle speed suppression unit 5a4 applies a pulse signal to the piezoelectric diaphragm 2o of the notification device to sound a buzzer to warn the operator.

[0075] FIG. 7 is a schematic diagram showing a space G' including the grass cut by the mowing device 3 per unit time, and FIG. 8 is a drawing showing the screen of the portable terminal 6 when inputting the working conditions necessary for calculating the clogging index.

[0076] Before the start of the mowing operation, the clogging prevention unit 5a2 calculates a clogging index G by the following formula (1) using the values of the working speed V, the current grass height H1, the cutting height H2, and the grass density D of the field input by the operator on the portable terminal 6 and the value of the actual cutting width B previously stored in the storage device 5a1. The clogging index G is the volume of grass cut by the mowing device 3 per unit time, and the actual cutting width B, the working speed V, the current grass height H1, the cutting height H2, and the density D are the working conditions of the mowing operation. Note that the actual cutting width B is, in other words, the working width.

[0077] G = Actual cutting width B × Working speed V × (Current grass height H1 - Cutting height H2) × Density D...(1) The actual cutting width B and the working speed V are the width and depth of the area where grass is cut per unit time in the field. "(Current grass height - Cutting height)" is the height of the grass cut per unit time. Then, the volume of the space G' (see Fig. 7) in the field that contains the grass cut per unit time is obtained by "[Actual cutting width B × Working speed V × (Current grass height - Cutting height)]". By multiplying this volume G' by the density D of the grass in the space G', the volume of the grass cut per unit time G (= Grass clogging index G) is calculated. In the following, the height obtained by subtracting the cutting height from the current grass height ("Current grass height - Cutting height") is referred to as the "Cut grass height", and for this cut grass height, as shown in Fig. 7, the symbol H3 is used.

[0078] At this time, the value of the blade cutting width A is set for the actual cutting width B used in the calculation of the grass clogging index G, and it is configured so that it cannot be changed by the operator. That is, the grass clogging index G is calculated on the premise of performing the grass cutting operation over the entire left - right width of the pair of blades 3a1.

[0079] The target vehicle speed during the grass cutting operation is input for the working speed V.

[0080] The current grass height H1 is measured and input by the operator as the height of the grass before grass cutting, which is the object of the grass cutting operation. Since the grass height varies for each grass in the field, an approximately average grass height is input.

[0081] The cutting height H2 is the height at which the pair of blades 3a1 cuts, that is, the target grass height after the grass cutting operation, and is the height from the ground to the blades 3a1.

[0082] The density D can be selected by radio buttons r1, r2 to be either manually input by selecting from a plurality of density icons or automatically input by reading out the density information stored in the storage device 5a2. As shown in Fig. 8, by default, the radio button r1 (manual input) is selected.

[0083] In the case of manual input, when any one of the three icons a1 to a3 displayed on the mobile terminal 6 is pressed and selected by the operator, the value of the density corresponding to the icon is input.

[0084] Specifically, when the icon a1 indicating the normal grass density (thickness) is selected, the value of 0.15 [g / cm 3 is automatically input as the density D, which is frequently used in the industry as the grass density.

[0085] When the icon a2 indicating a density higher than the normal density is selected, a predetermined value higher than 0.15 [g / cm 3 is input as the density D.

[0086] When the icon a3 indicating a density lower than the normal density is selected, a predetermined value lower than 0.15 [g / cm 3 is input as the density D.

[0087] On the other hand, when automatic input is selected by pressing the radio button r2, the mobile terminal 6 transmits information to that effect to the vehicle ECU 5a.

[0088] Here, in the present embodiment, during the teaching run performed prior to the mowing operation by automatic driving, for the purpose of measuring the grass density, the mowing device 3 is temporarily driven automatically and the mowing operation is performed. Between this temporary mowing operation and the normal mowing operation by manual driving, the grass density measurement unit 5a3 is configured to automatically measure the grass density based on the load of the engine 2d, and associate the information on the grass density with the field shape information and store (record) it in the storage device 5a1.

[0089] When a signal of the operation of the radio button r2 is transmitted from the mobile terminal 6 to the vehicle ECU 5a, the clogging prevention unit 5a2 refers to the database of the field shape information stored in the storage device 5a1, and searches for a field having the field shape information including the position information of the vehicle body 2 acquired by the positioning device 9. If there is a corresponding (in other words, the work target) field, the clogging prevention unit 5a2 reads out the information on the grass density associated with the field shape information and transmits it to the mobile terminal 6, and displays it in the automatic input field 11 in the work condition input screen shown in FIG. 8.

[0090] Therefore, when the radio button r2 is operated and the vehicle body 2 is located in a field where grass cutting work has been performed in the past, or when teaching running is performed prior to the grass cutting work and the field shape information has been acquired, the density information acquired at that time is automatically input.

[0091] In this way, by pressing the radio button r2, the value of the grass density acquired in the past can be displayed on the mobile terminal 6, so that an accurate grass density can be easily input and the operator can grasp the measured grass density.

[0092] On the other hand, as a result of searching for a field having the field shape information including the position information of the vehicle body 2 and there is no corresponding field, the clogging prevention unit 5a2 reads out the initial setting value of 0.15 [g / cm 3 generally used in the industry as the grass density from the storage device 5a1, transmits it to the mobile terminal 6, and displays it in the automatic input field 11. This initial setting value is stored in the storage device 5a1 in advance.

[0093] Here, as a result of grasping the density automatically input by pressing the radio button r2, if the operator determines that the density is unqualified, the operator can also manually input the density by pressing the icons a1 to a3.

[0094] In this embodiment, as described above, the mobile terminal 6 is configured to be able to input the density D. However, it is not necessarily required to configure it in this way. A predetermined value of density, for example, 0.15 [g / cm 3 can be stored in the storage device 5a1 in advance, and when calculating the clogging index G, the clogging prevention unit 5a2 may be configured to read and use this value. In other words, the mobile terminal 6, which is an example of an input device, may be configured to receive information on the density D from the vehicle ECU 5a.

[0095] In this way, when the values of the working speed V, the current grass height H1, the cutting height H2, and the density D are input and the start switch 10 shown in FIG. 8 is pressed, the information on the input working conditions is transmitted from the mobile terminal 6 to the vehicle ECU 5a and stored in the storage device 5a1. At this point, the values of the current grass height H1 and the grass density D are determined.

[0096] Thereafter, the information on the working conditions transmitted from the mobile terminal 6 and the information on the actual cutting width B (= blade cutting width A) are read from the storage device 5a1, and the clogging prevention unit 5a2 calculates the clogging index G.

[0097] Next, the clogging prevention unit 5a2 determines whether the clogging index G is equal to or greater than the clogging risk value Gp. The clogging risk value Gp is set to a predetermined value at which the possibility of clogging of the conveyance path 8 increases. This specific value is arbitrarily set according to the conveyance speed of the grass in the conveyance path, the size (diameter, etc.) of the conveyance path, the shape of the conveyance path, and the like.

[0098] As a result of the determination, when the clogging index G is lower than the clogging risk value Gp, the clogging prevention unit 5a2 stores and sets the input work condition information as work information in the storage device 5a1. Thereafter, the vehicle ECU 5a drives a pair of left and right DC motors 3g2, and the height positions of the pair of blades 3a1 are automatically changed to the cutting height H2 stored in the storage device 5a1. When the automatic operation is set by operating the operation changeover switch 2n2, after the height positions of the pair of blades 3a1 are changed, the automatic traveling unit 5b3 starts the automatic operation, and the mowing operation is advanced. When the manual operation is set, after the height positions of the pair of blades 3a1 are changed, based on the operator's operation, the mower 1 travels and the mowing operation is performed.

[0099] On the other hand, as a result of the determination, when the clogging index G is greater than or equal to the clogging risk value Gp, the clogging prevention unit 5a2 recognizes that the grass is likely to clog in the conveyance path 8, and therefore proposes (recommends) to the operator a modified work condition plan in which at least one value among the actual cutting width B, the work speed V, and the cutting height H2 is added to or subtracted from (in other words, increased or decreased) and changed. In the present embodiment, the change of the actual cutting width B is configured to be proposed only when the automatic operation is set by the operation changeover switch 2n2.

[0100] Specifically, the clogging prevention unit 5a2 calculates the proposed modified work condition plan as follows, and transmits a condition change proposal request (an instruction signal for displaying the modified work condition plan) to the mobile terminal 6 together with the information on the proposed modified work condition plan, and causes the mobile terminal 6 to display a condition change proposal screen (see FIG. 10).

[0101] FIG. 9 is a flowchart showing a procedure for proposing work conditions that are less likely to clog, and FIG. 10 is a drawing showing a condition change proposal screen displayed on the mobile terminal 6 when a condition change proposal request is received.

[0102] FIG. 10 shows a condition change proposal screen in the case of automatic operation in which the cutting width can be changed.

[0103] When calculating the working conditions proposed to the operator, the clogging prevention unit 5a2 first recalculates the clogging index G using Equation (2) in which the cutting height H2 among the working speed V and the cutting height H2 input on the working condition input screen shown in FIG. 8 is increased (step s1).

[0104] G = actual cutting width B × working speed V × (actual grass height H1 - cutting height H2’) × density D...(2) The cutting height H2’ is a value obtained by increasing the value of the input cutting height H2. The amount of increase in the cutting height H2 may be configured as a predetermined length, or may be configured as a predetermined ratio length of the input actual grass height H1 or cutting height H2.

[0105] Next, the clogging prevention unit 5a2 determines whether or not the recalculated clogging index G is equal to or greater than the clogging risk value Gp (step s2).

[0106] As a result of the determination, if the clogging index G is less than the clogging risk value Gp, the clogging prevention unit 5a2 transmits a condition change proposal request to the mobile terminal 6 together with the information on the corrected working condition proposal with the increased cutting height H2, and displays a condition change proposal screen (see FIG. 10) including the corrected working condition proposal, and proposes it to the operator (step s3).

[0107] On the other hand, as a result of the determination, if the clogging index G is still equal to or greater than the clogging risk value Gp, the clogging prevention unit 5a2 recalculates the clogging index G using the following Equation (3) using the cutting height H2’ and the value V’ obtained by decreasing the input working speed V (step s4).

[0108] G = actual cutting width B × working speed V’ × (actual grass height H1 - cutting height H2’) × density D...(3) The amount of decrease in the working speed V to V’ may be a predetermined amount (speed), or may be a predetermined ratio of the input working speed V.

[0109] Thus, when calculating the clogging index G with the cutting height and working speed changed, the clogging prevention unit 5a2 determines whether the recalculated clogging index G is equal to or greater than the clogging risk value Gp (step s5).

[0110] As a result of the determination, when the clogging index G is less than the clogging risk value Gp, the clogging prevention unit 5a2 transmits a condition change proposal request to the mobile terminal 6 together with the information on the modified working condition proposal with the cutting height and working speed changed, and causes a condition change proposal screen (see FIG. 10) including the modified working condition proposal to be displayed (step s3).

[0111] On the other hand, as a result of the determination, when the clogging index G is still equal to or greater than the clogging risk value Gp, the clogging prevention unit 5a2 determines whether the automatic operation is set by the operation changeover switch 2n2 (step s6).

[0112] As a result of the determination, when the manual operation is set, the clogging prevention unit 5a2 calculates an integer cutting height H2'' such that the cutting height becomes the minimum value within the range where the clogging index G is less than the clogging risk value Gp (step s7). At this time, the working speed V' reduced in step s4 is used to calculate the cutting height H2''.

[0113] Next, together with the calculated cutting height H2'', the values of the working speed V' and the actual cutting width B, a condition change proposal request is transmitted to the mobile terminal 6, and a condition change proposal screen (see FIG. 10) including the modified working condition proposal is displayed and proposed to the operator.

[0114] On the other hand, when the automatic operation is set, the clogging prevention unit 5a2 recalculates the clogging index G by the following formula (4) using the actual cutting width B' obtained by reducing the value of the actual cutting width B equal to the blade cutting width A to 3 / 4 (step s8).

[0115] G = actual cutting width B' × working speed V' × (current grass height H1 - cutting height H2') × density D...(4) Thus, when calculating the clogging index G with the cutting height, working speed, and actual cutting width changed, the clogging prevention unit 5a2 determines whether or not the recalculated clogging index G is equal to or greater than the clogging risk value Gp (step s9).

[0116] As a result of the determination, if the clogging index G is less than the clogging risk value Gp, the clogging prevention unit 5a2 transmits a condition change proposal request to the mobile terminal 6 together with the information on the modified working condition proposal with the cutting height, working speed, and actual cutting width changed, and causes a condition change proposal screen (see FIG. 10) including the modified working condition proposal to be displayed (step s3). As will be described in detail later, when the working condition in which the actual cutting width is changed to a width that is 3 / 4 of the blade cutting width A is set by the operation start switch 10 shown in FIG. 10, when automatically driving the field, the planned travel route is recalculated and set so that the overlap margin C becomes 1 / 4 of the blade cutting width A.

[0117] On the other hand, as a result of the determination, if the clogging index G is still equal to or greater than the clogging risk value Gp, the clogging prevention unit 5a2 calculates an integer cutting height H2'' such that the cutting height becomes the minimum value within the range where the clogging index G is less than the clogging risk value Gp (step s10). At this time, the working speed V' reduced in step s4 is used, and the actual cutting width B' reduced in step s8 is used to calculate the cutting height H2''.

[0118] Next, together with the calculated cutting height H2'', the values of the working speed V' and the actual cutting width B', a condition change proposal request is transmitted to the mobile terminal 6, and a condition change proposal screen (see FIG. 10) including the modified working condition proposal is displayed and proposed to the operator (step s3).

[0119] In a conventional lawn mower, it is not easy for an operator who is not used to the lawn mowing work in particular to come up with working conditions that are less likely to clog, and there is a risk that clogging frequently occurs in the conveyance path 8.

[0120] In contrast, in the present embodiment, as described above, when the working conditions input by the operator are likely to cause grass clogging, a modified working condition plan that is less likely to cause grass clogging is proposed on the mobile terminal 6. Therefore, even an operator who is not accustomed to the mowing work can easily set the working conditions in which grass clogging is less likely to occur, and can suppress the grass clogging of the conveyance path 8 to the grass collection container 4.

[0121] Furthermore, in the present embodiment, as shown in FIG. 9, a modified working condition plan in which the input mowing height V is increased is preferentially calculated and proposed to the operator. Therefore, grass clogging can be suppressed without extending the time required for the mowing work as in the case of changing the input working speed or the actual mowing width.

[0122] In addition, when the grass clogging index G is equal to or greater than the grass clogging danger value Gp even if the mowing height is increased, instead of the mowing height, the working speed (vehicle speed) and the actual mowing width are first changed. Therefore, it is possible to suppress the situation where only the mowing height is greatly sacrificed to suppress grass clogging (in other words, the mowing height becomes extremely high), and to balance the working conditions.

[0123] On the other hand, on the condition change proposal screen shown in FIG. 10, the operator selects the modified working condition plan proposed by the grass clogging prevention unit 5a2 (pattern 1), new conditions are input for the three working conditions of the actual mowing width B, the working speed V, and the mowing height (pattern 2), or the original working conditions input on the working condition input screen are selected (pattern 3).

[0124] Which of these three patterns to proceed to is configured to be selected by pressing the radio buttons r3 to r5.

[0125] That is, on the condition change proposal screen, in addition to starting the mowing operation according to the revised working condition plan proposed by the clogging prevention unit 5a2, there are multiple options such as the operator inputting new working conditions to start the operation, or starting the mowing operation according to the working conditions that have already been determined to have a high possibility of clogging the conveyance path 8.

[0126] The following describes the input of new conditions when the radio button r4 is pressed.

[0127] The actual mowing width B is configured to be inputtable by the operator when the automatic driving is set, and is not input in the case of the mowing operation by manual driving. The blade mowing width A is calculated as the actual mowing width B.

[0128] The input of the actual mowing width B is configured to be input as a ratio to the blade mowing width A. More specifically, the operator selects and inputs from among four options: a width of 1 / 4 of the blade mowing width A, a width of 1 / 2 of the blade mowing width A, a width of 3 / 4 of the blade mowing width A, and the blade mowing width A (full width) on the mobile terminal 6.

[0129] An integer value is input by the operator in the columns of the mowing height and the working speed.

[0130] When the mowing height, the actual mowing width, and the working speed (vehicle speed) are input and the operation start switch 10 is pressed, the information on the input working conditions is transmitted from the mobile terminal 6 to the vehicle ECU 5a. The information on the new working conditions transmitted to the vehicle ECU 5a is stored in the storage device 5a1.

[0131] Based on the information on the working conditions received from the mobile terminal 6, the clogging prevention unit 5a2 calculates a clogging index G, and determines whether or not this clogging index G is equal to or greater than a clogging risk value Gp at which the possibility of clogging the conveyance path 8 increases.

[0132] As a result of the determination, when the clogging index G is less than the clogging risk value Gp, the information on the input working conditions is stored in the storage device 5a1 by the clogging prevention unit 5a2 and updated as working information.

[0133] Subsequently, the vehicle ECU 5a drives a pair of left and right DC motors 3g2, and the height positions of the pair of blades 3a1 are automatically changed to the cutting height stored in the storage device 5a1.

[0134] At this time, when it is set to automatic driving by operating the operation switching switch 2n2 and the actual cutting width B is set to a value other than the full width of the blade cutting width A, the information on the actual cutting width is sent from the vehicle ECU 5a to the automatic driving ECU 5b as the information on the working width. Then, based on the information on the new working width, the planned travel route R' is newly calculated by the route calculation unit 5b2 of the automatic driving ECU 5b.

[0135] Specifically, the route calculation unit 5b2 newly calculates a planned travel route R' in which the interval between the straight travel routes R1' is set so that the actual cutting width when traveling on each straight travel route R1' except for the first straight travel route R1' becomes the set actual cutting width B.

[0136] For example, when the actual cutting width is set to 3 / 4 of the blade cutting width A, when traveling on each straight travel route R1' except for the first straight travel route R1', the overlapping margin (see Fig. 2) with the worked area where the mowing operation was performed when traveling on the previous (before turning) straight travel route R1' becomes 1 / 4 of the blade cutting width A, and the interval between the straight travel routes R1' is calculated.

[0137] In this case, the interval between the straight travel routes R1' of the newly calculated solid-line planned travel route R' is 3 / 4 of the length of the interval between the straight travel routes R1 of the dashed-line planned travel route R calculated after the teaching travel.

[0138] In addition, in Fig. 6, the first straight travel route R1' of the newly calculated planned travel route R' is drawn with a position shift from the first straight travel route R1 of the planned travel route R calculated immediately after the teaching travel for the sake of convenience, but it is not always necessary to calculate the planned travel route so that the first straight travel route R1' is at a position shifted from the first straight travel route R1.

[0139] In addition, when the actual cutting width B is set to be narrow, an overlap margin C occurs when the lawn mower 1 travels on a straight travel path R1' other than the first straight travel path R1', so the actual working width becomes narrow. However, when the lawn mower 1 travels on the first straight travel path R1', since no overlap margin C occurs, the working width by the mowing device 3 becomes equal to the blade cutting width A.

[0140] After a new planned travel route R' is calculated, automatic driving by the automatic driving unit 5b3 is started along the calculated planned travel route R', and the mowing operation is advanced. When set to manual driving, after the height position of the pair of blades 3a1 is changed, based on the operation of the operator, the lawn mower 1 travels while the mowing operation is performed.

[0141] On the other hand, if as a result of the determination, the clogging index G is equal to or greater than the clogging danger value Gp, a new revised working condition plan of the working conditions is calculated according to the procedure shown in FIG. 9, and new proposed conditions are displayed on the condition change proposal screen shown in FIG. 10.

[0142] On the other hand, when the revised working condition plan proposed by the clogging prevention unit 5a2 is selected by pressing the radio button r3, or when the original working conditions are selected by pressing the radio button r5 and the operation start switch 10 is pressed, the mobile terminal 6 transmits the information of the selected working conditions to the vehicle ECU 5a.

[0143] The clogging prevention unit 5a2 stores the information of the working conditions received from the mobile terminal 6 in the storage device 5a1, updates it as working information from the originally input value, and transmits the information of the working speed to the automatic driving ECU 5b. Then, the vehicle ECU 5a drives the pair of left and right DC motors 3g2 to automatically change the height position of the pair of blades 3a1 to the cutting height stored (set) in the storage device 5a1.

[0144] In the case of automatic driving, when the actual cutting width B is set to be other than the full width of the blade cutting width A, the height position of the pair of blades 3a1 is changed, and information on the actual cutting width is sent from the vehicle ECU 5a to the automatic driving ECU 5b as information on the working width.

[0145] Then, in the same manner as the calculation of the above-mentioned planned travel route R', a new planned travel route R' is calculated by the route calculation unit 5b2 of the automatic driving ECU 5b. That is, a new planned travel route R' is calculated in which the interval between the straight travel routes R1' is set so that the actual cutting width when traveling on each straight travel route R1' except the first straight travel route R1' becomes the set actual cutting width B. In other words, the route calculation unit 5b2 corrects the interval between the straight travel routes R1 of the planned travel route R calculated after the teaching travel to a new planned travel route R' narrowed by a predetermined interval (1 / 4, 2 / 4, or 3 / 4 of the blade cutting width A).

[0146] Thereafter, automatic driving along the planned travel route R' by the automatic driving unit 5b3 is started, and the mowing operation is advanced. During automatic driving, the automatic driving unit 5b3 transmits the set working speed V or V' to the vehicle ECU 5a as information on the target speed, and controls the vehicle speed of the traveling vehicle body 2 to the set working speed V or V'.

[0147] When set to manual driving, after the height position of the pair of blades 3a1 is changed, based on the operator's operation, the mower 1 travels while the mowing operation is performed.

[0148] During the mowing operation by manual driving, as described above, when the vehicle speed of the vehicle body 2 detected by the vehicle speed sensor 2k exceeds the set working speed V or V', the vehicle speed suppression unit 5a4 is configured to display a warning on the monitor 12 and apply a pulse signal to the piezoelectric diaphragm 2o of the notification device to sound a buzzer.

[0149] Therefore, during the mowing operation by manual driving, it is possible to prevent the vehicle speed of the traveling vehicle body 2 from continuing to travel in a state where it unintentionally exceeds the set working speed V or V', and it is possible to suppress the occurrence of grass clogging.

[0150] FIG. 11 is a schematic perspective view of a lawn mower 100 according to another preferred embodiment of the present invention. FIG. 11 shows a state in which the lawn mower 100 is viewed from the lower right front.

[0151] The lawn mower 100 according to the present embodiment is configured in the same manner as the lawn mower 1 of the above-described embodiment shown in FIGS. 1 to 10, except for the points described below, and thus the same effects can be obtained.

[0152] In the present embodiment, the mowing device 3 is disposed between the front and rear of a pair of front wheels 2a and a pair of rear wheels 2b and is close to the grass collection container 4, so a blower is not provided. The grass cut by the mowing device 3 is blown backward by a pair of blades 3a1 and is conveyed to the grass collection container 4 through a conveyance path (shooter) 8.

[0153] Further, in the present embodiment, a first weight sensor 2p is disposed on the bottom surface of the conveyance path 8, and a second weight sensor 2q is disposed on the bottom surface of the grass collection container 4. The first weight sensor 2p detects the weight of the cut grass passing through the conveyance path 8 at predetermined time intervals, and the second weight sensor 2q detects the weight of the cut grass stored in the grass collection container 4 at predetermined time intervals. Each detection result is output to the vehicle ECU 5a and stored in the storage device 5a1, but the detection result one time before is erased from the storage device 5a1.

[0154] The grass clogging prevention unit 5a2 is configured to calculate a grass clogging index G (= the volume of grass cut per unit time) by the following formula (5) based on the weight P of the grass, which is the detection result of the first weight sensor 2p output to the vehicle ECU 5a.

[0155] G = weight P of grass / density D...(5) For the grass density D, a value of 0.15 [g / cm 3 that is frequently used in the industry is adopted.

[0156] In this way, by detecting the weight in the conveying path 8, the clogging index G can be easily calculated during the mowing operation. When the clogging index G calculated each time during the mowing operation is equal to or greater than the clogging danger value Gp, the clogging prevention unit 5a2 can reduce the clogging index G and suppress clogging by changing the working speed V or / and the cutting height H2.

[0157] In this embodiment, in the case of automatic driving, during driving, based on the detection signal of the first weight sensor 2p that is updated (acquired) each time, the cutting height and the working speed are calculated according to the procedure during manual driving in FIG. 9 until the clogging index G becomes less than the clogging danger value Gp, and are automatically changed.

[0158] Also, in the case of manual driving, when the clogging index G is equal to or greater than the clogging danger value Gp, the conditions of the calculated cutting height and working speed are displayed on the mobile terminal 6 and proposed to the operator.

[0159] On the other hand, in this embodiment, since the rear camera is not provided, the vehicle ECU 5a is configured to detect clogging from the detection values of the first and second weight sensors 2p and 2q as follows.

[0160] First, when the first weight sensor 2p detects that the weight of the grass is equal to or greater than a predetermined value and the weight of the grass in the grass collection container 4 detected by the second weight sensor 2q is increasing, the vehicle ECU 5a determines that no clogging has occurred.

[0161] Also, when the first weight sensor 2p detects that the weight of the grass is less than the predetermined value and the weight of the grass in the grass collection container 4 detected by the second weight sensor 2q has hardly changed, the vehicle ECU 5a determines that there is no grass above the cutting height H2.

[0162] Furthermore, when the first weight sensor 2p detects that the weight of the grass is equal to or greater than a predetermined value and the weight of the grass in the grass collection container 4 detected by the second weight sensor 2q has not changed significantly, the vehicle ECU 5a determines that grass clogging has occurred in the conveyance path 8.

[0163] At this time, the vehicle ECU 5a displays a warning indicating that grass clogging has occurred on the monitor 12 and the mobile terminal 6, applies a pulse signal to the piezoelectric diaphragm 2o of the notification device to sound the buzzer, stops the driving of the traveling motor 2g, and stops the traveling vehicle body 2.

[0164] Therefore, it is possible to prevent a situation where grass clogging occurs and the lawn mower 1 continues to travel while scattering the cut grass on the field.

[0165] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention described in the claims. Needless to say, these modifications are also included in the scope of the present invention.

[0166] For example, in the embodiments shown in FIGS. 1 to 10, as shown in FIG. 9, the cutting height H2 is preferentially changed. However, the working speed V may be preferentially changed, or the actual cutting width B may be preferentially changed.

[0167] Also, in the embodiments shown in FIGS. 1 to 10, when calculating the grass clogging index G, the grass clogging prevention unit 5a2 is configured to use either the value of the grass density manually input or the density information measured during teaching travel or when working previously. However, before the grass cutting operation (specifically, at the time of inputting the working conditions or before that), the lawn mower 1 may be manually driven to travel on the field to be worked for a certain period of time, and during that time, the grass density may be measured based on the magnitude of the load on the engine 2d, and the grass clogging index G may be calculated using the measured density value.

[0168] Furthermore, in the embodiments shown in FIGS. 1 to 10, before starting the mowing operation by automatic driving, it is configured to automatically drive while controlling the drive of the traveling motor 2g with the set working speed V as the target vehicle speed. However, during the mowing operation in the automatic driving according to the set working conditions (working speed V or V', mowing height H2, H2' or H2'', actual mowing width B or B'), the grass density is measured based on the engine load at predetermined time intervals, and the value of the clogging index G is updated each time using the density. When the clogging index G becomes equal to or higher than the clogging danger value Gp, the vehicle speed V may be automatically decreased so that the clogging index G becomes less than the clogging danger value Gp.

[0169] In the field to be worked, since the grass density varies from place to place, in this way, during automatic driving, by changing the vehicle speed V (= working speed) according to the constantly changing grass density, clogging can be effectively suppressed.

[0170] Note that as a result of updating the value of the density D at each location in the field, when the clogging index G becomes equal to or higher than the clogging danger value Gp, instead of the vehicle speed V, or together with the vehicle speed V, the mowing height H2 may be configured to be changed.

[0171] In this case, for example, in the procedure during manual driving in FIG. 9, the vehicle speed and the mowing height corresponding to the density updated each time are calculated. Then, the traveling motor 2g is controlled with the calculated vehicle speed as the target vehicle speed, and the DC motor 3g2 is driven so that the calculated mowing height is obtained to change the height position of the pair of blades 3a1. Thereby, clogging can be effectively suppressed, the sacrifice of the vehicle speed can be suppressed, and the balance between the vehicle speed and the mowing height can be achieved. The actual mowing width B is fixed at a value set before the start of the operation. Also, it is desirable to configure the density measured at each location in the field to be stored in the storage device 5a1 in association with the position information.

[0172] In addition, in the embodiments shown in FIGS. 1 to 10, as shown in FIG. 10, the clogging prevention unit 5a2 is configured to calculate and propose one working condition, but it may be configured to calculate and propose a plurality of working conditions.

[0173] For example, as the first proposal, display the working condition in which the cutting height is changed to a predetermined length or by a predetermined ratio. As the second proposal, display the working condition with a reduced working speed. As the third proposal, configure to display the working condition with a narrowed actual cutting width. Thereby, clogging in the conveyance path 8 to the grass collection container 4 can be suppressed, and the operator can easily select which working condition among the cutting height, the working speed, and the actual cutting width to compromise.

[0174] Furthermore, in the embodiments shown in FIGS. 1 to 10, when the clogging index G calculated based on the working conditions input on the working condition input screen (see FIG. 8) is equal to or greater than the clogging danger value Gp, it is configured to propose the working condition with the cutting height H2 adjusted higher. However, a threshold is set for the cut grass height H3 calculated from the input current grass height H1 and the cutting height H2. When the clogging index G is equal to or greater than the clogging danger value Gp and the cut grass height H3 is equal to or greater than the threshold, it may be configured to propose the working condition of mowing in two steps.

[0175] In this case, when the cut grass height H3 is equal to or greater than the threshold, calculate the condition in which the cutting height H2 is increased so that the cut grass height H3 during the first grass mowing operation is half the height of the cut grass height according to the input conditions, and display it on the mobile terminal 6.

[0176] Specifically, display on the mobile terminal 6 the value calculated by "(current grass height H1 + cutting height H2) / 2" or its approximate value as the cutting height H2 during the first grass mowing operation. Then, display the cutting height H2 during the second grass mowing operation as the input cutting height on the mobile terminal 6.

[0177] That is, in the first mowing operation, half of the desired mowing height of the operator is cut, and in the second operation, working conditions for performing the mowing operation so as to achieve the desired cutting height of the operator are proposed to the operator.

[0178] When performing the mowing operation in two steps in this way, the mowed grass height becomes half, making it easier for the mowed grass to be blown away by the wind, and the volume of the mowed grass can be halved, so that grass jams in the conveying path 8 can be effectively suppressed.

[0179] However, on the other hand, the mowing operation will be performed twice for each location in the field, resulting in an increase in working time. Therefore, for the case of dividing into two times, it is desirable to calculate and propose a working speed such that the working speed reaches the maximum value within the range where the grass jam index G is less than Gp. By configuring in this way, while effectively preventing grass jams, the overall working time can be shortened as much as possible. Note that the working speed may not be the maximum value, but may be the working speed input by the operator.

[0180] On the other hand, when the grass jam index G is greater than or equal to the grass jam danger value Gp and the mowed grass height H3 calculated from the input current grass height H1 and cutting height H2 is less than the threshold value, it may be configured to propose working conditions according to the procedure shown in FIG. 9. However, the cutting height H2 may remain the input condition, and it may be configured to calculate working conditions with the actual cutting width B and the working speed (vehicle speed) adjusted and display them on the mobile terminal 6.

[0181] In this case, until the grass jam index G becomes less than the grass jam danger value Gp, step by step, the actual cutting width B is narrowed to 3 / 4 of the blade cutting width A, (if still greater than or equal to Gp) the working speed V is decreased by a predetermined speed or a predetermined ratio to V', (if still greater than or equal to Gp) the working speed V' is decreased by a predetermined speed or a predetermined ratio, (if still greater than or equal to Gp) the actual cutting width B is narrowed to 2 / 4, and so on. By configuring to perform value search of working conditions in this way, it is possible to balance the actual cutting width and the working speed while suppressing grass jams.

[0182] In this way, by providing a threshold for the mowing height H3 and configuring to propose a two-pass mowing operation only when the mowing height H3 is equal to or higher than the threshold, the two-pass mowing operation is proposed only when the possibility of grass clogging is quite high, and a single-pass mowing operation is proposed otherwise, so that an extension of the working time can be suppressed.

[0183] Also, in the embodiments shown in FIGS. 1 to 10, the current grass height H1, the cutting height H2, the working speed V, and the grass density D can be input on the working condition input screen (see FIG. 8). In addition to these conditions, as shown in FIG. 10, the condition of the actual cutting width B may be configured to be inputtable (selective input).

[0184] Furthermore, in the embodiments shown in FIGS. 1 to 10, on the working condition input screen shown in FIG. 8 and the condition change proposal screen shown in FIG. 10, the numerical value of the working speed can be input. However, the working speed may be configured to be selectable and inputtable alternatively in the same way as the values of the cutting width and density.

[0185] In addition, in the embodiments shown in FIGS. 1 to 10, it is determined whether or not the calculated grass clogging index G is equal to or higher than the grass clogging risk value Gp which is a reference value (threshold). When the grass clogging index G is equal to or higher than the grass clogging risk value Gp, on the condition change proposal screen (see FIG. 10), it is configured to display that the possibility of grass clogging is high. However, a reference value Gp1 and a Gp2 lower than the reference value Gp1 are set. When the calculated grass clogging index G is equal to or higher than the reference value Gp1, it is configured to display that the possibility of grass clogging is high. When the grass clogging index G is equal to or higher than the reference value Gp2 and lower than Gp1, it may be configured to display that there is a possibility of grass clogging.

[0186] On the other hand, when the grass clogging index G is lower than the reference value Gp2, it is recognized that the possibility of grass clogging is low. Therefore, it is desirable to configure to set the input working conditions as working information and shift to the mowing operation.

[0187] Furthermore, in the embodiments shown in FIGS. 1 to 10, when the radio button r2 (see FIG. 8) displayed on the mobile terminal 6 is operated, the clogging prevention unit 5a2 searches for a farm field having farm field shape information including the position information of the vehicle body 2 acquired by the positioning device 9, reads out the information on the grass density D associated with the corresponding farm field, and is configured to display it on the mobile terminal 6. However, it is not always necessary to specify the farm field based on the position information of the vehicle body 2. A list of farm fields may be displayed on the mobile terminal 6 to allow the operator to select a farm field for inputting the grass density D. If there is no farm field to be worked on in the list, a predetermined value (for example, 0.15 [g / cm 3 ) may be automatically input as the density D.

[0188] Also, in the embodiments shown in FIGS. 1 to 10, during the teaching run performed prior to the mowing operation by automatic driving and during the normal mowing operation by manual driving, the grass density measurement unit 5a3 is configured to measure the grass density D based on the detection signal of the load of the engine 2d. However, before the actual mowing operation (specifically, when inputting the working conditions or before that), the mowing operation may be performed by manual driving or automatic driving for a certain period of time, and the density D may be measured based on the load of the engine 2d.

[0189] Furthermore, in the embodiments shown in FIGS. 1 to 10, the control unit 5 is configured to display various screens, information, warnings, etc. on the monitor 12, which is an example of the display unit of the present invention, and the mobile terminal 6. However, these display contents may be configured to be displayed on either the monitor or the mobile terminal.

Explanation of Reference Numerals

[0190] 1 Mower 2 Traveling vehicle body 3 Mowing device 4 Grass collection container 5 Control unit 6 Mobile terminal 7 Blower 8 Conveyor path 9 Positioning device 10 Work start switch 11 Automatic input field 12 Monitor

Claims

1. A lawn mower that performs mowing work while traveling in a field, comprising: a traveling vehicle body; a mowing device attached to the traveling vehicle body; a grass collection container for storing the grass cut by the mowing device; a conveyance path extending from the mowing device to the grass collection container; an input device for inputting various working conditions; a display unit capable of displaying various information; and a control unit for controlling the display on the display unit, wherein the control unit includes a clogging prevention unit for suppressing clogging of grass in the conveyance path and a storage device for storing various information; the input device accepts input of a working speed indicating the vehicle speed during mowing work, the current grass height which is the grass height before mowing work, the cutting height which is the target height after mowing work, and information on the density of the grass for mowing work; the clogging prevention unit calculates a clogging index using the following formula from the information on the working speed, current grass height, cutting height, and grass density input from the input device, and the information on the working width of the mowing device input from the input device or stored in the storage device. When the calculated clogging index is equal to or greater than a predetermined value, at least one numerical value among the cutting height, working speed, and working width is added or subtracted to calculate a modified working condition plan in which the calculated clogging index is less than the predetermined value, and the calculated modified working condition plan is displayed on the display unit. A lawn mower characterized by this. (Equation 1) Clogging index = working width × working speed × (current grass height - cutting height) × grass density

2. When the calculated clogging index is equal to or greater than a predetermined value, the clogging prevention is configured to preferentially calculate and display on the display unit a modified working condition plan in which the cutting height is added to the numerical values of the cutting height, working speed, and working width in the calculation of the modified working condition plan. The lawn mower according to claim 1, characterized by this.

3. The control unit includes a vehicle speed suppression unit for warning of an excessive vehicle speed of the traveling vehicle body, wherein the vehicle speed suppression unit acquires information on the vehicle speed of the traveling vehicle body during mowing work, and when the vehicle speed during mowing work exceeds the working speed input and set from the input device, is configured to output a warning to the display unit. The lawn mower according to claim 1 or 2, characterized by this.

4. It is provided with a positioning device for acquiring the position information of the traveling vehicle body, The control unit includes a route calculation unit that calculates a planned travel route including a plurality of straight travel routes formed linearly and turning routes that turn from each straight travel route to an adjacent straight travel route, and an automatic travel unit that automatically travels the traveling vehicle body along the planned travel route calculated by the route calculation unit. The route calculation unit is configured to calculate a planned travel route after teaching travel based on the field shape information acquired by teaching travel by manual operation. Also, The clogging prevention unit is configured to be able to set information on the working speed, current grass height, cutting height, and grass density input from the input device, and to update the information on the numerical values of the set cutting height, working speed, and working width based on the calculated modified working condition plan by a predetermined operation. Further, when the numerical value of the working width input and set by the input device is updated and decreased, The lawn mower according to claim 1 or 2, wherein the route calculation unit corrects the planned travel route calculated after teaching travel to a new planned travel route in which the straight travel routes are narrowed by a predetermined interval.

5. The lawn mowing device is configured to be driven by the rotational power output from the engine of the traveling vehicle body. The input device is configured to be able to select, as a method of inputting the grass density, manual input for inputting the density value and automatic input for reading and inputting the pre-stored density information. The lawn mower according to claim 4, wherein when the automatic input is selected, the grass density information measured based on the magnitude of the load on the engine in the field to be worked is read from the storage device and automatically input, and when the measured grass density information is not stored in the storage device, a predetermined value pre-stored in the storage device is read and automatically input.

6. The control unit is configured to measure the grass density at predetermined time intervals based on the magnitude of the load on the engine while the lawn mowing operation in the automatic driving by the automatic travel unit is being performed. The clogging prevention unit calculates a clogging index using the newly measured grass density value each time the grass density is measured. The lawn mower according to claim 5, wherein when this clogging index becomes equal to or greater than a predetermined value, the vehicle speed of the traveling vehicle body is controlled to be low and / or the cutting height is changed to be high until the clogging index becomes less than the predetermined value.

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