JP7709683B2 - Grass trimmer - Google Patents

Description

The present invention relates to a lawnmower for mowing grass.

Conventionally, there is known a lawnmower that performs grass cutting work while traveling through a field, etc.

For example, Patent Document 1 discloses a grass cutter that uses a grass cutting device to cut grass while transporting the cut grass to a grass collection container attached to the machine body.

This grass cutter is configured to predict grass clogging in the transport path to the grass collection container based on the weather over the past 12 hours and current humidity, and display the recommended working speed on a monitor installed on the machine.

Therefore, even when the grass is wet, the operator can reduce the amount of grass passing through the transport path to the grass collection container per unit time by keeping the vehicle speed during mowing work to the recommended operating speed, thereby preventing grass clogging in the transport path.

JP 2004-248621 A

However, because grass clogging can occur in the transport path to the grass collection container even when the humidity is low, it is not easy to predict grass clogging in the transport path based on weather and humidity information alone. Experienced workers can adjust the amount of grass passing through the transport path per unit time and prevent grass clogging by increasing the overlap of the working width or reducing the working speed based on the condition and height of the grass, but beginners who do not have such experience may cause grass clogging frequently.

Therefore, the present invention aims to provide a grass cutter that can prevent grass clogging in the conveying path to the grass collection container, even by an operator who is inexperienced in grass cutting work.

The object of the present invention is to
A grass cutter that performs grass cutting work while traveling in a field,
A running vehicle body,
A grass cutting device attached to the traveling vehicle body;
A grass collection container for storing grass cut by the grass cutting device;
A conveying path extending from the grass cutting device to a grass collection container;
an input device for inputting various work conditions;
A display unit capable of displaying various information;
A control unit that controls the display of the display unit,
The control unit includes a grass jam prevention unit that suppresses grass jamming in the transport path, and a storage device that stores various information.
the input device receives input of information on a work speed indicating a vehicle speed during mowing work, a current grass height which is the grass height before mowing work, a mowing height which is a target height after mowing work, and a density of grass to be mowed;
This is achieved by a grass clogging prevention unit that calculates a grass clogging index using the following formula from information on the working speed, current grass height, mowing height, and grass density input from the input device, and information on the working width of the grass mowing device input from the input device or stored in the memory device, and if this calculated grass clogging index is equal to or greater than a predetermined value, calculates revised working condition proposals by adding or subtracting at least one numerical value of the mowing height, working speed, and working width so that the calculated grass clogging index is less than the predetermined value, and displays the calculated revised working condition proposals on the display unit.
(Equation 1)
Grass jamming index = working width x working speed x (current grass height - mowing height) x grass density According to the present invention, when the grass jamming index is above a predetermined value and grass jamming is likely to occur, the grass jamming prevention unit adds or subtracts at least one numerical value from the mowing height, working speed and working width so that the grass jamming index is less than the predetermined value, and calculates revised working condition proposals that are revised so that the grass jamming index is less than the predetermined value, and displays this on the display unit.Therefore, working conditions can be easily set that are less likely to cause grass jamming, and therefore even workers who are unfamiliar with grass mowing work can prevent grass jamming in the transport path to the grass collection container.

In a preferred embodiment of the present invention,
The grass clogging prevention device is configured such that, when the calculated grass clogging index is equal to or greater than a predetermined value, in calculating the revised working condition proposal, the numerical values of the mowing height, working speed, and working width are given priority in calculating the revised working condition proposal by adding the mowing height, and the calculated revised working condition proposal is displayed on the display unit.

According to this preferred embodiment of the present invention, the control unit is configured to give priority to calculating and displaying the revised work condition proposal calculated by adding the mowing height, so that grass clogging can be suppressed without extending the time required for mowing work, as would be the case if the work speed were slowed down or the work width were narrowed in order to reduce the volume of grass mowed per unit time.

In a further 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 grass-mowing operation, and to output a warning on the display unit when the vehicle speed during grass-mowing operation exceeds the set operating speed input from the input device.

According to this preferred embodiment of the present invention, if the vehicle speed becomes faster than the set operating speed, a warning is issued to the operator, thereby reducing the volume of grass cut per unit time and preventing grass clogging.

In a further preferred embodiment of the present invention,
A positioning device for acquiring position information of the traveling vehicle body,
The control unit has a route calculation unit that calculates a planned driving route including a plurality of straight routes formed in a straight line and a turning route that turns from each straight route to an adjacent straight route, and an automatic driving unit that automatically drives the traveling vehicle body along the planned driving route calculated by the route calculation unit,
The route calculation unit is configured to calculate a planned travel route after teaching travel based on field shape information acquired by teaching travel by manual driving, and
The grass jam prevention unit is configured to be able to set information on the working speed, current grass height, mowing height, and grass density input from the input device, and is configured to update the set numerical information on the mowing height, working speed, and working width based on the calculated revised working condition proposal by a predetermined operation, and further, when the numerical information on the working width input and set by the input device is updated and decreased,
The route calculation unit corrects the planned driving route calculated after teaching driving to a new planned driving route in which straight routes are narrowed by a predetermined interval.

According to this preferred embodiment of the present invention, when the numerical value of the working width is input by the input device based on the proposed revised working conditions, and is updated and reduced, the route calculation unit is configured to calculate a new planned travel route in which the distance between the straight routes is narrowed. Therefore, even in a grass cutting device with a constant cutting width, overlapping margins are generated in the cutting width, or the overlapping margins are increased. Therefore, the volume of grass cut per unit time by the grass cutting device is reduced, and grass clogging can be suppressed.

In yet another preferred embodiment of the present invention,
The grass cutting device is configured to be driven by rotational power output from an engine of the traveling vehicle body,
The input device is configured to select, as a method for inputting grass density, a manual input for inputting a density value and an automatic input for reading and inputting pre-stored density information,
When the automatic input is selected, information on grass density measured in the field to be worked on based on the magnitude of the engine load is read from the memory device and automatically input, and if the information on the grass density to be measured is not stored in the memory device, a predetermined value previously stored in the memory device is read and automatically input.

According to this preferred embodiment of the present invention, when inputting the working conditions, the grass density measured in the field to be worked on can be automatically input based on the magnitude of the engine load, so that an accurate value of the grass congestion index G can be calculated.

Furthermore, according to this preferred embodiment of the present invention, if the density value measured based on the magnitude of the engine load is not stored in the memory device, a predetermined value stored in advance is automatically input, so that the grass congestion index can be calculated even in fields where the grass density has never been measured.

In a further preferred embodiment of the present invention,
The control unit is configured to measure grass density at predetermined time intervals based on the magnitude of the load on the engine while the automatic driving unit is performing a grass mowing operation,
The grass clogging prevention unit calculates a grass clogging index using a newly measured grass density value every time the grass density is measured,
When the grass congestion index reaches or exceeds a predetermined value, the vehicle speed of the traveling vehicle body is controlled to be low and/or the mowing height is increased until the grass congestion index falls below the predetermined value.

According to this preferred embodiment of the present invention, while the vehicle is automatically driving in a field to perform grass cutting work, the grass density is measured at a predetermined time interval based on the magnitude of the engine load, and a grass clogging index is calculated. If the grass clogging index reaches or exceeds a predetermined value, the vehicle speed and/or mowing height is changed. Therefore, even when the grass density, which changes from moment to moment during work, becomes high, the grass clogging index can be maintained below the predetermined value, and grass clogging can be effectively suppressed.

The present invention makes it possible to provide a grass cutter that can prevent grass clogging in the transport path to the grass collection container, even for operators who are unfamiliar with grass cutting work.

FIG. 1 is a schematic left side view of a grass cutter according to a preferred embodiment of the present invention. FIG. 2 is a schematic plan view of the grass cutter shown in FIG. FIG. 3 is a schematic perspective view of the grass cutting device. FIG. 4 is an enlarged perspective view of the vicinity of the cutting height cylinder disposed at the right front portion of the grass cutting device. FIG. 5 is a control block diagram of the grass cutter shown in FIG. FIG. 6 is a schematic plan view showing a planned driving route used for automatic driving. FIG. 7 is a schematic diagram showing a space including grass cut per unit time by a grass cutting device. FIG. 8 is a diagram showing the screen of a mobile terminal when inputting the work conditions required for calculating the grass clogging index. FIG. 9 is a flowchart showing a procedure for proposing working conditions that are less likely to cause grass clogging. FIG. 10 is a diagram showing a condition change proposal screen displayed on the mobile terminal when a condition change proposal request is received. FIG. 11 is a schematic perspective view of a grass cutter according to another preferred embodiment of the present invention.

Below, a detailed description of a preferred embodiment of the present invention will be given with reference to the attached drawings.

Figure 1 is a schematic left side view of a grass cutter 1 according to a preferred embodiment of the present invention, and Figure 2 is a schematic plan view of the grass cutter 1 shown in Figure 1.

In this specification, unless otherwise specified, the side in the direction of travel of the lawnmower 1 is referred to as the "front" and the opposite side as the "rear", and the left side as you face the forward direction of travel of the lawnmower 1 is referred to as the "left" and the opposite side as the "right".

The grass cutter 1 comprises a running body 2, a grass cutting device 3 attached to the front of the running body 2, a grass collection container 4 provided at the rear of the running body 2, a grass clipping transport path 8 extending from the grass cutting device 3 to the grass collection container 4, a blower 7 that transports grass clippings cut by the grass cutting device 3 to the grass collection container 4 via the transport path 8, a control unit 5 (see Figure 5) that controls each device of the machine, a display unit 13 that displays various information, and a positioning device 9 that acquires position information of the running body 2.

The traveling vehicle body 2 is equipped with a driver's seat 2e where 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 for the machine body 1, a speed change transmission mechanism 2f (see Figure 5) that changes the speed of the rotational power output from the engine 2d and transmits it to the grass cutting device 3 and the blower 7, and an operating unit 2n for operating the machine body.

In this embodiment, the traveling vehicle body 2 is configured to be capable of not only being manually driven on a farm field based on the operator's operation, but also of automatically traveling while automatically steering the steering wheel 2c (hereinafter referred to as "automatic driving").

The pair of left and right rear wheels 2b are driven to rotate by a travel motor 2g shown in FIG. 5, which causes the traveling vehicle body 2 to move forward.

The display unit 13 includes a monitor 12 and a mobile terminal 6 arranged near the steering wheel 2c.

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

The mobile terminal 6 is removably attached to the rear surface of the steering post 2h that supports the steering wheel 2c.

In this embodiment, the mobile terminal 6 is configured as a tablet computer and has a touch panel that can input various information. The mobile terminal 6 also functions as the "input device" of the present invention that inputs the work conditions for the grass cutting work.

The operating unit 2n is provided with a mowing height change switch 2n1 that changes the mowing height of the grass cutting device 3, and an operation change switch 2n2 that switches between automatic driving and manual driving (see FIG. 2).

Figure 3 is a simplified perspective view of the grass cutting device 3.

The grass cutting device 3 is equipped with a pair of left and right auxiliary wheels 3b located at the front, a mower deck 3a including a pair of left and right blades (rotary blades) 3a1 (see Figure 2), a pair of left and right cutting height cylinders 3g that change the height position of the mower deck 3a, and a connector 3e to the traveling vehicle body 2. Each cutting height cylinder 3g is covered by a cylinder cover 3g3.

The left and right blades 3a1 are rotated by the power output from the engine 2d. With the pair of blades 3a1 rotating, the traveling vehicle body 2 moves forward, allowing the grass in the field to be cut. The grass cut by the grass cutting device 3 is transported through the transport path 8 by the air blown by the blower 7 (see Figure 1) driven by the engine 2d, and is stored in the grass collection container 4.

In this specification, as shown in Figure 2, the width in the left-right direction that can be mowed when the traveling vehicle body 2 moves forward is referred to as the "blade mowing width," and the left-right width of the portion where the worked area where grass has already been mowed and the blade mowing width overlap when the vehicle body 2 moves forward is referred to as the "overlap margin."

The width where the grass is actually mowed when moving forward is called the "actual mowing width" or "working width", and as shown in FIG. 2, the actual mowing width B is the blade mowing width A minus the overlap C. If there is no overlap C, the actual mowing width B is equal to the blade mowing width A. If there is overlap C, the actual mowing width B is narrower than the blade mowing width A. In this embodiment, the working width (actual mowing width) is increased or decreased by adjusting the width of the overlap C, but the working width (actual mowing width) may also be changed by changing the left-right spacing between the pair of blades 3a1 using a motor or the like.

The pair of auxiliary wheels 3b are each 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 connecting fulcrum 3d. The left and right auxiliary wheel arms 3c are connected to each other by a link mechanism 3f.

The link mechanism 3f includes a connecting shaft 3f1 that extends to the left and right, and a pair of left and right connectors 3f2 that connect the connecting shaft 3f1 to the auxiliary wheel arm 3c.

Figure 4 is an enlarged perspective view of the vicinity of the cutting height cylinder 3g located at the right front of the grass cutting device 3. Figure 4 shows the state in which the cylinder cover 3g3 has been removed.

A connector 3h that is roughly shaped like the letter 9 in cross section is attached to each of the left and right ends of the connecting shaft 3f1, and the rod 3g1 of the cutting height cylinder 3g is inserted into a rectangular gap 3h1 formed at the top of each connector 3h and attached to the connector 3h.

When the left and right rods 3g1 are extended by driving the DC motors 3g2 of the cutting height cylinders 3g, the connecting shaft 3f1 rotates clockwise in a right side view together with the left and right connectors 3h. As a result, the pair of connectors 3f2 rotate forward and downward around the connecting shaft 3f1, and the pair of auxiliary wheel arms 3c rotate forward and downward.

Because the pair of auxiliary wheels 3b are in contact with the ground before and after the DC motor 3g2 is driven, the mower deck 3a is raised by the rotation of the pair of auxiliary wheel arms 3c.

In response to this, when the left and right rods 3g1 are contracted by driving the DC motors 3g2 of the cutting height cylinders 3g, the connecting shaft 3f1 rotates counterclockwise in a right side view together with the left and right connectors 3h. As a result, the pair of connectors 3f2 are rotated upward toward the front around the connecting shaft 3f1, and the pair of auxiliary wheel arms 3c are rotated upward toward the front.

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

In this embodiment, as described above, the height position of the mower deck 3a can be changed by extending and contracting the pair of cutting height cylinders 3g, but changing 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 grass cutter 1 shown in FIG. 1, and FIG. 6 is a schematic plan view showing a planned travel route used for automatic driving.

The control unit 5 includes a vehicle ECU 5a that controls each device of the vehicle, and an autonomous driving ECU 5b that transmits control signals to the vehicle ECU 5a during autonomous driving.

The autonomous driving ECU 5b includes a storage device 5b1 that stores various information such as the planned driving route, field shape information, vehicle body 2 position information, and working width, a route calculation unit 5b2 that calculates the planned driving route, and an autonomous driving unit 5b3 that controls the steering of the front wheels 13 and the driving of the vehicle body 2 during autonomous driving to automatically drive the vehicle body 2. The position information of the vehicle body 2 is acquired by a positioning device 9 provided on the top of the vehicle body 2.

The positioning device 9 amplifies the GNSS signal from the GNSS satellite, acquires information on the transmission time of the GNSS signal, and can then calculate the position of the traveling vehicle body 2 using triangulation.

In so-called teaching travel, the route calculation unit 5b2 calculates the planned travel routes R, R' shown in FIG. 6 based on the field shape information acquired by the mower 1 going around the field once based on the operator's operation and on the blade mowing width A or actual mowing width B of the mower 3.

The planned travel route R is a travel route calculated by assuming that the actual mowing width B is equal to the blade mowing width A, and is calculated by the route calculation unit 31 to include multiple straight routes R1 formed in a straight line and turning routes R2 that turn from each straight route R1 to an adjacent straight route R1, as shown by the dashed lines in Figure 6.

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

In this embodiment, when mowing work is performed by automatic driving in a field where mowing work is being performed for the first time, first, field shape information is acquired by teaching driving, and immediately after that, the planned driving route R is calculated, and then the work conditions are input on the work condition input screen (see Figure 8) displayed on the mobile terminal 6.

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

When the vehicle ECU 5a receives steering information from the automatic driving unit 5b3, the vehicle ECU 5a drives the steering motor 2i to rotate 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.

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

Furthermore, the vehicle ECU 5a increases or decreases the drive speed of the travel motor 2g based on information about the target vehicle speed output from the automatic travel unit 5b3 and the detection signal of the vehicle speed sensor 2k that detects the travel speed of the travelling vehicle body 2, thereby increasing or decreasing the actual vehicle speed of the vehicle body 2. Note that in this embodiment, the rear wheels 2b are configured to be rotated and driven by the travel motor 2g, but the rotational power of the engine 2d may be transmitted to the rear wheels 2b via a speed change transmission mechanism such as an HST to drive them.

In addition, the vehicle ECU 5a drives the throttle motor 2m, which adjusts the amount of air intake into the engine 2d, to increase or decrease the engine speed, and controls the variable speed transmission mechanism 2f to increase or decrease the rotation speed of the rotary blade of the grass cutting device 3 and the air volume of the blower 7.

The vehicle ECU 5a is also configured to be able to wirelessly communicate with the mobile terminal 6, and can obtain information input by the worker to the mobile terminal 6 via wireless communication, as well as send display requests (display instruction signals) for various screens to the mobile terminal 6. The storage device of the mobile terminal 6 stores layout information for various display screens, and is configured to display layouts corresponding to various display requests sent from the vehicle ECU 5a, and to add and display information on work conditions (including information on proposed revised work conditions) received together with the display requests within the screen layout.

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

The rear camera 2r faces downward and rearward and can capture images of the condition of the field after mowing work has been performed.

In conventional grass cutters, when an operator operates the machine while looking ahead, if a grass jam occurs in the conveying path 8 to the grass collection container 4, the operator often does not realize that the grass cuts are being scattered from the grass cutter 3 onto the field until the machine turns.

In contrast, in this embodiment, the monitor 12 located near the steering wheel 2c displays the state of the field behind the vehicle body 2, allowing the operator to quickly become aware of any grass jams that may occur. In addition, the operator can check the area where the grass has been cut by looking at the monitor 12.

The vehicle ECU 5a also includes a storage device 5a1 that stores various information such as a database of work conditions including blade mowing width and field shape information, a grass jam prevention unit 5a2 that prevents grass jamming in the conveying path 8, a grass density measurement unit 5a3 that measures the density of grass in the field, and a vehicle speed suppression unit 5a4 that issues a warning when the vehicle is traveling at an excessive (high) speed during manual driving.

Before the start of mowing work, the grass jam prevention unit 5a2 calculates a grass jam index, which indicates the likelihood of grass jamming in the conveying path 8, based on the work conditions entered into the mobile terminal 6, and suggests to the worker that they change the work conditions if the grass jam index is high.

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

For example, during mowing work, if the grass density increases and the load on the engine 2d increases, the amount of fuel injected by the fuel injection device 2d1 in the engine 2d increases in order to maintain the engine 2d speed detected by the engine speed sensor 2d2.

Conversely, when the grass density decreases during mowing work and the load on the engine 2d decreases, the amount of fuel injected by the fuel injection device 2d1 in the engine 2d is reduced in order to maintain the rotation speed of the engine 2d.

In this way, the amount of fuel injected changes depending on the density of the grass during mowing work, so the grass density measurement unit 5a3 can measure the grass density from the change in the amount of fuel injected by the fuel injection device 2d1 caused by the change in engine load.

It is not necessarily necessary to measure the load on engine 2d from the amount of fuel injected into engine 2d. For example, a microphone that picks up sound may be placed near engine 2d, and the engine load may be measured based on the volume of the engine sound, and the grass density may be measured.

In this case, for example, by storing a numerical table in advance in the memory device 5a1 that records the relationship between the volume of the engine sound, which represents the engine load, and the grass density, it is possible to search the numerical table for the value of the grass density in the field that is linked to the volume of the engine sound that is actually detected.

When the operation mode is set to manual operation by the operation changeover switch 2n2 and the vehicle speed of the vehicle body 2 detected by the vehicle speed sensor 2k exceeds the operation speed that is set (more specifically, stored in the memory device 5a1) during grass cutting operation, the vehicle speed suppression unit 5a4 displays a warning on the monitor 12. At the same time, the vehicle speed suppression unit 5a4 applies a pulse signal to the piezoelectric vibration plate 2o of the alarm device to sound a buzzer and warn the operator.

Figure 7 is a schematic diagram showing the space G' containing the grass cut per unit time by the grass cutting device 3, and Figure 8 is a diagram showing the screen of the mobile terminal 6 when inputting the work conditions required to calculate the grass clogging index.

The grass clogging prevention unit 5a2 calculates a grass clogging index G according to the following formula (1) using the values of the working speed V, current grass height H1, mowing height H2, and grass density D in the field input by the worker on the mobile terminal 6 before starting the mowing work, and the value of the actual mowing width B pre-stored in the memory device 5a1. The grass clogging index G is the volume of grass mowed per unit time by the mowing device 3, and the actual mowing width B, working speed V, current grass height H1, mowing height H2, and density D are the working conditions of the mowing work. The actual mowing width B is, in other words, the working width.

G = actual cutting width B x working speed V x (current grass height H1 - cutting height H2) x density D... (1)
The actual mowing width B and the working speed V are the width and depth of the area mowed per unit time in the field, and "(current grass height - mowing height)" is the height of the grass mowed per unit time. The volume of the space G' (within the field) containing the grass mowed per unit time (see FIG. 7) is obtained by "actual mowing width B x working speed V x (current grass height - mowing height)". This volume G' is multiplied by the grass density D in the space G' to calculate the volume G of the grass mowed per unit time (=grass clogging index G). In the following, the height obtained by subtracting the mowing height from the current grass height ("current grass height - mowing height") is referred to as the "mowing grass height", and the symbol H3 is used for this mowing grass height, as shown in FIG. 7.

At this time, the actual mowing width B used to calculate the grass clogging index G is set to the value of the blade mowing width A and cannot be changed by the operator. In other words, the grass clogging index G is calculated on the assumption that grass cutting work is performed over the entire width of the pair of blades 3a1 in the left-right direction.

The target vehicle speed during grass cutting work is input as the work speed V.

In the current grass height H1, the height (pre-mowing height) of the grass to be mowed is measured by the operator and input. Note that the grass height varies depending on the grass in the field, so an approximate average grass height is input.

The mowing height H2 is the height cut by the pair of blades 3a1, i.e., the target grass height after mowing, and is the height from the ground to the blades 3a1.

The density D can be selected by manual input, which is selected from a number of density icons, or by automatic input, which reads and inputs density information stored in the storage device 5a2, using radio buttons r1 and r2. As shown in FIG. 8, radio button r1 (manual input) is selected by default.

In the case of manual input, the operator presses and selects one of the three icons a1 to a3 displayed on the mobile terminal 6, and the density value corresponding to that icon is input.

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

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.

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.

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

In this embodiment, during the teaching run that is performed prior to the automatic driving of the mowing operation, the mowing device 3 is temporarily automatically driven to perform the mowing operation in order to measure the grass density. During this temporary mowing operation and the normal mowing operation performed by the manual driving, the grass density measuring unit 5a3 is configured to automatically measure the grass density based on the load of the engine 2d, and store (record) the grass density information in the storage device 5a1 by linking it to the field shape information.

When a signal indicating the operation of radio button r2 is sent from the mobile terminal 6 to the vehicle ECU 5a, the grass jam prevention unit 5a2 refers to the database of field shape information stored in the memory device 5a1 and searches for a field having field shape information that includes the position information of the vehicle body 2 acquired by the positioning device 9. If a matching field (in other words, the work target field) is found, the grass jam prevention unit 5a2 reads out the grass density information linked to the field shape information, sends 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.

Therefore, if mowing work has been performed in the past in the field in which the vehicle body 2 is located when radio button r2 is operated, or if a teaching run has been performed prior to mowing work and field shape information has been acquired, the density information acquired at that time will be automatically entered.

In this way, by pressing radio button r2, the previously obtained grass density value can be displayed on the mobile terminal 6, making it easy to input an accurate grass density and allowing the worker to understand the measured grass density.

On the other hand, if there is no corresponding field as a result of searching for fields having field shape information including the position information of the vehicle body 2, the grass clogging prevention unit 5a2 reads out from the memory device 5a1 the initial setting value of 0.15 [g/ ^cm3 ], which is generally used in the industry as a grass density, and transmits it to the mobile terminal 6 to display it in the automatic input field 11. This initial setting value is pre-stored in the memory device 5a1.

Here, if the worker determines that the density that was automatically input by pressing radio button r2 is inappropriate after understanding the density, the worker can manually input the density by pressing icons a1 to a3.

As described above, in this embodiment, the density D is configured to be input using the mobile terminal 6, but this configuration is not necessarily required, and a predetermined density value, for example, a value of 0.15 [g/ ^cm3 ] may be stored in advance in the memory device 5a1, and the grass clogging prevention unit 5a2 may read and use this value when calculating the grass clogging index G. 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.

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

Then, the information on the working conditions sent from the mobile terminal 6 and the information on the actual mowing width B (= blade mowing width A) are read from the memory device 5a1, and the grass clogging prevention unit 5a2 calculates the grass clogging index G.

Next, the grass jam prevention unit 5a2 judges whether the grass jam index G is equal to or greater than the grass jam risk value Gp. The grass jam risk value Gp is set to a predetermined value that increases the possibility of grass jamming in the conveying path 8, and this specific value is set arbitrarily depending on the grass conveying speed in the conveying path, the size of the conveying path (diameter, etc.), the shape of the conveying path, etc.

If the result of the determination is that the grass clogging index G is below the grass clogging risk value Gp, the grass clogging prevention unit 5a2 stores and sets the input work condition information as work information in the memory device 5a1. The vehicle ECU 5a then drives the pair of left and right DC motors 3g2 to automatically change the height position of the pair of blades 3a1 to the mowing height H2 stored in the memory device 5a1. If automatic operation is set by operating the operation changeover switch 2n2, after the height position of the pair of blades 3a1 is changed, automatic operation by the automatic driving unit 5b3 is started and the grass mowing work proceeds. If manual operation is set, after the height position of the pair of blades 3a1 is changed, the grass mower 1 travels based on the operator's operation while mowing work is performed.

In contrast, if the result of the judgment is that the grass jamming index G is equal to or greater than the grass jamming danger value Gp, the grass jamming prevention unit 5a2 recognizes that grass is likely to jam in the conveying path 8, and therefore proposes (recommends) to the operator a revised working condition proposal in which at least one of the values of the actual mowing width B, the working speed V, and the mowing height H2 is changed by adding or subtracting (in other words, increasing or decreasing). Note that in this embodiment, the system is configured so that a change to the actual mowing width B is only proposed when the operation mode is set to automatic operation by the operation changeover switch 2n2.

Specifically, the grass jam prevention unit 5a2 calculates the proposed revised work conditions as follows, and transmits a condition change proposal request (an instruction signal to display the revised work conditions proposal) together with information on the proposed revised work conditions to the mobile terminal 6, causing the mobile terminal 6 to display a condition change proposal screen (see FIG. 10).

Figure 9 is a flowchart showing the procedure for proposing working conditions that are less likely to cause weed clogging, and Figure 10 is a diagram showing the condition change proposal screen displayed by the mobile terminal 6 when a condition change proposal request is received.

Figure 10 shows the condition change suggestion screen for automatic operation where the mowing width can be changed.

When calculating the working conditions to be proposed to the operator, the grass jam prevention unit 5a2 first recalculates the grass jamming index G using formula (2) in which the working speed V and the cutting height H2 input on the working conditions input screen shown in FIG. 8 are changed to a higher value, with the cutting height H2 being changed (step s1).

G = actual cutting width B x working speed V x (current grass height H1 - cutting height H2') x density D... (2)
The mowing height H2' is a value obtained by increasing the input value of the mowing height H2. The amount by which the mowing height H2 is increased may be configured as a predetermined length, or may be configured as a length that is a predetermined percentage of the input current grass height H1 or mowing height H2.

Next, the grass clogging prevention unit 5a2 determines whether the recalculated grass clogging index G is equal to or greater than the grass clogging danger value Gp (step s2).

If the result of the determination is that the grass clogging index G is below the grass clogging danger value Gp, the grass clogging prevention unit 5a2 sends a condition change proposal request to the mobile terminal 6 along with information about the revised work condition proposal in which the mowing height H2 has been increased, and displays a condition change proposal screen (see Figure 10) including the revised work condition proposal, and makes a proposal to the worker (step s3).

On the other hand, if the result of the judgment is that the grass clogging index G is still equal to or greater than the grass clogging danger value Gp, the grass clogging prevention unit 5a2 recalculates the grass clogging index G using the following formula (3) that uses the cutting height H2' and the value V' obtained by lowering the input work speed V (step s4).

G = actual cutting width B x working speed V' x (current grass height H1 - cutting height H2') x density D... (3)
The amount by which the work speed V is reduced to V' may be a predetermined amount (speed), or may be a predetermined percentage of the input work speed V.

After calculating the grass clogging index G with the changed mowing height and working speed, the grass clogging prevention unit 5a2 determines whether the recalculated grass clogging index G is equal to or greater than the grass clogging danger value Gp (step s5).

If the result of the determination is that the grass clogging index G is below the grass clogging danger value Gp, the grass clogging prevention unit 5a2 sends a condition change proposal request to the mobile terminal 6 along with information on the revised work condition proposal in which the mowing height and work speed have been changed, and displays a condition change proposal screen (see Figure 10) including the revised work condition proposal (step s3).

On the other hand, if the result of the judgment is that the grass clogging index G is still equal to or greater than the grass clogging danger value Gp, the grass clogging prevention unit 5a2 judges whether the operation changeover switch 2n2 has been set to automatic operation (step s6).

If the result of the determination is that manual operation is set, the grass jam prevention unit 5a2 calculates an integer mowing height H2'' that will result in a minimum mowing height within a range in which the grass jam index G is less than the grass jam danger value Gp (step s7). At this time, the working speed V' subtracted in step s4 is used to calculate the mowing height H2''.

Next, a request for a proposed change of conditions is sent to the mobile terminal 6 together with the calculated mowing height H2'', the working speed V', and the actual mowing width B, and a proposed change of conditions screen (see FIG. 10) including revised proposed working conditions is displayed and proposed to the worker.

In contrast, when the automatic operation is set, the grass jam prevention unit 5a2 recalculates the grass jamming index G using the following formula (4) using the actual cutting width B' obtained by reducing the value of the actual cutting width B, which is equal to the blade cutting width A, to 3/4 (step s8).

G = actual cutting width B' x working speed V' x (current grass height H1 - cutting height H2') x density D... (4)
After calculating the grass jamming index G with the mowing height, working speed, and actual mowing width changed in this manner, the grass jamming prevention unit 5a2 determines whether the recalculated grass jamming index G is equal to or greater than the grass jamming danger value Gp (step s9).

If the result of the judgment is that the grass clogging index G is below the grass clogging danger value Gp, the grass clogging prevention unit 5a2 sends a condition change proposal request to the mobile terminal 6 along with information on the revised work condition proposal in which the cutting height, work speed, and actual cutting width have been changed, and causes a condition change proposal screen (see FIG. 10) including the revised work condition proposal to be displayed (step s3). Note that, as will be described in detail later, if the work conditions in which the actual cutting width has been changed to a width that is 3/4 of the blade cutting width A are set by the work start switch 10 shown in FIG. 10, when the field is automatically driven, the planned travel route is recalculated and set so that the overlap C is 1/4 of the blade cutting width A.

In contrast, if the result of the judgment is that the grass clogging index G is still equal to or greater than the grass clogging danger value Gp, the grass clogging prevention unit 5a2 calculates an integer mowing height H2'' that will result in a minimum mowing height within the range in which the grass clogging index G is less than the grass clogging danger value Gp (step s10). At this time, the working speed V' subtracted in step s4 is used as the working speed, and the actual mowing width B' subtracted in step s8 is used as the actual mowing width to calculate the mowing height H2''.

Next, a request for a proposed change of conditions is sent to the mobile terminal 6 together with the calculated cutting height H2'', the working speed V', and the actual cutting width B', and a proposed change of conditions screen (see FIG. 10) including revised proposed working conditions is displayed and proposed to the worker (step s3).

With conventional grass cutters, it is not easy to come up with working conditions that are less likely to cause grass clogging, especially for operators who are unfamiliar with grass cutting, and there is a risk of grass clogging occurring frequently in the conveying path 8.

In contrast to this, in this embodiment, as described above, when the working conditions input by the worker are likely to cause grass clogging, the mobile terminal 6 is configured to propose revised working conditions that are less likely to cause grass clogging. Therefore, even workers who are unfamiliar with mowing work can easily set working conditions that are less likely to cause grass clogging, and grass clogging in the transport path 8 to the grass collection container 4 can be suppressed.

Furthermore, in this embodiment, as shown in FIG. 9, the system is configured to preferentially calculate and propose modified work condition proposals in which the input mowing height V is increased to the higher value to the operator. Therefore, grass clogging can be suppressed without extending the time required for mowing work, as would be the case if the input work speed or actual mowing width were changed.

In addition, if the grass clogging index G is equal to or greater than the grass clogging danger value Gp even when the mowing height is increased, the system is configured to change the working speed (vehicle speed) and actual mowing width first, rather than the mowing height. This prevents the mowing height from being significantly sacrificed in order to prevent grass clogging (in other words, the mowing height becoming significantly higher), and allows for a balanced working condition.

On the other hand, on the condition change proposal screen shown in FIG. 10, the operator can select the revised working condition proposal proposed by the grass jam prevention unit 5a2 (pattern 1), input new conditions for the three working conditions of actual mowing width B, working speed V, and mowing height (pattern 2), or select the original working conditions input on the working condition input screen (pattern 3).

Which of these three patterns to proceed to is selected by pressing radio buttons r3 to r5.

In other words, on the condition change proposal screen, in addition to starting mowing work with the revised work condition proposal proposed by the grass jam prevention unit 5a2, multiple options are available, such as the operator inputting new work conditions and starting work, or starting mowing work with work conditions that have already been determined to have a high probability of causing a blockage in the conveying path 8.

Below is an explanation of how to enter new conditions when radio button r4 is pressed.

The actual cutting width B can be input by the operator when automatic operation is set, but is not input when mowing is performed manually, and the blade cutting width A is calculated as the actual cutting width B.

The actual cutting width B is input as a percentage of the blade cutting width A, and more specifically, the operator selects and inputs from four options on the mobile terminal 6: 1/4 width, 1/2 width, 3/4 width, and blade cutting width A (full width).

The operator enters integer values into the cutting height and working speed fields.

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

The grass jam prevention unit 5a2 calculates the grass jam index G based on the information on the working conditions received from the mobile terminal 6, and determines whether this grass jam index G is equal to or greater than the grass jam risk value Gp, at which the possibility of the conveying path 8 becoming clogged increases.

If the result of the determination is that the grass clogging index G is below the grass clogging danger value Gp, the grass clogging prevention unit 5a2 stores the input work condition information in the storage device 5a1 and updates it as work information.

Then, the vehicle ECU 5a drives the pair of left and right DC motors 3g2, and the height positions of the pair of blades 3a1 are automatically changed to the mowing height stored in the memory device 5a1.

At this time, if automatic operation is set by operating the operation changeover switch 2n2 and the actual mowing width B is set to a value other than the full width of the blade mowing width A, information on the actual mowing width is sent from the vehicle ECU 5a to the automatic driving ECU 5b as information on the working width. Then, the route calculation unit 5b2 of the automatic driving ECU 5b calculates a new planned driving route R' based on the new working width information.

Specifically, the route calculation unit 5b2 calculates a new planned driving route R' in which the distance between the straight routes R1' is set so that the actual mowing width when driving on each straight route R1' except for the first straight route R1' is the set actual mowing width B.

For example, if the actual mowing width is set to 3/4 of the blade mowing width A, when traveling on each straight path R1' except for the first (initial) straight path R1', the distance between the straight paths R1' is calculated so that the overlap (see Figure 2) with the worked area where grass was mowed when traveling on the previous straight path R1' (before turning) is 1/4 of the blade mowing width A.

In this case, the distance between the straight paths R1' of the newly calculated solid-line planned driving path R' is 3/4 the length of the distance between the straight paths R1 of the dashed-line planned driving path R calculated after teaching driving.

In FIG. 6, for convenience, the first straight route R1' of the newly calculated planned driving route R' is drawn shifted from the first straight route R1 of the planned driving route R calculated immediately after teaching driving, but it is not necessarily necessary to calculate the planned driving route so that the first straight route R1' is shifted from the first straight route R1.

In addition, if the actual mowing width B is set narrow, when the mower 1 travels on a straight path R1' other than the first straight path R1', overlapping allowance C occurs, and the actual working width becomes narrower. However, when the mower 1 travels on the first straight path R1', overlapping allowance C does not occur, and the working width by the mowing device 3 becomes equal to the blade mowing width A.

After the new planned driving route R' is calculated, automatic driving by the automatic driving unit 5b3 is started so as to follow the calculated planned driving route R', and the mowing work proceeds. When manual driving is set, after the height position of the pair of blades 3a1 is changed, the mowing work is performed while the mower 1 is traveling based on the operator's operation.

In contrast, if the result of the determination is that the grass clogging index G is equal to or greater than the grass clogging danger value Gp, new proposed modified work conditions are calculated using the procedure shown in FIG. 9, and the new proposed conditions are displayed on the condition change proposal screen shown in FIG. 10.

On the other hand, when the work start switch 10 is pressed after the revised work condition proposal proposed by the grass jam prevention unit 5a2 is selected by pressing the radio button r3, or the original work conditions are selected by pressing the radio button r5, the mobile terminal 6 transmits information on the selected work conditions to the vehicle ECU 5a.

The grass jam prevention unit 5a2 stores the work condition information received from the mobile terminal 6 in the memory device 5a1, updates the work information from the originally input value, and transmits the work speed information to the automatic driving ECU 5b. After that, the vehicle ECU 5a drives the pair of left and right DC motors 3g2, and the height positions of the pair of blades 3a1 are automatically changed to the mowing height stored (set) in the memory device 5a1.

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

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

After that, the automatic driving unit 5b3 starts automatic driving along the planned driving route R', and the grass cutting work proceeds. During automatic driving, the automatic driving unit 5b3 transmits the set work speed V or V' to the vehicle ECU 5a as target speed information, and controls the vehicle speed of the traveling vehicle body 2 to the set work speed V or V'.

When set to manual operation, the height position of the pair of blades 3a1 is changed, and then the grass cutter 1 travels and performs grass cutting work based on the operator's operation.

As described above, during manual mowing work, when the vehicle speed of the vehicle body 2 detected by the vehicle speed sensor 2k exceeds the set work 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 vibration plate 2o of the alarm device to sound a buzzer.

This prevents the traveling vehicle body 2 from unintentionally continuing to travel at a speed higher than the set operating speed V or V' during manual mowing work, thereby preventing grass jams from occurring.

Figure 11 is a schematic perspective view of a grass cutter 100 according to another preferred embodiment of the present invention. Figure 11 shows the grass cutter 100 as viewed from the right front bottom.

The grass cutter 100 according to this embodiment is configured similarly to the grass cutter 1 according to the embodiment shown in Figures 1 to 10, except for the points described below, and therefore can achieve the same effects.

In this embodiment, the grass cutting device 3 is disposed between the pair of front wheels 2a and the pair of rear wheels 2b, and is located close to the grass collection container 4, so no blower is provided. The grass cut by the grass cutting device 3 is blown backward by the pair of blades 3a1 and transported to the grass collection container 4 through the transport path (chute) 8.

In addition, in this embodiment, a first weight sensor 2p is disposed on the bottom surface of the conveying 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 grass clippings passing through the conveying path 8 at predetermined time intervals, and the second weight sensor 2q detects the weight of grass clippings contained in the grass collection container 4 at predetermined time intervals. Each detection result is output to the vehicle ECU 5a and stored in the memory device 5a1, but detection results from before the previous one are erased from the memory device 5a1.

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

G = Grass weight P / Density D (5)
The density D of the grass is set to a value of 0.15 [g/cm ³ ], which is frequently used in the industry.

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

In this embodiment, in the case of automatic driving, the working speed V and/or the mowing height H2 are calculated and automatically changed during driving based on the detection signal of the first weight sensor 2p, which is updated (acquired) each time, using the procedure for manual driving in Figure 9 until the grass clogging index G becomes less than the grass clogging danger value Gp.

In addition, in the case of manual operation, when the grass clogging index G is equal to or greater than the grass clogging danger value Gp, the calculated cutting height and working speed conditions are displayed on the mobile terminal 6 and suggested to the operator.

In contrast, in this embodiment, a rear camera is not provided, and the vehicle ECU 5a is configured to detect grass clogging from the detection values of the first and second weight sensors 2p and 2q as follows.

First, if the first weight sensor 2p detects that the weight of grass is equal to or greater than a predetermined value, and the weight of grass in the grass collection container 4 detected by the second weight sensor 2q is increasing, the vehicle ECU 5a determines that a grass jam has not occurred.

In addition, if the first weight sensor 2p detects that the weight of the grass is less 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 substantially, the vehicle ECU 5a determines that there is no grass with a mowing height of H2 or more.

Furthermore, if the first weight sensor 2p detects a grass weight 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 substantially, the vehicle ECU 5a determines that a grass jam has occurred in the conveying path 8.

At this time, the vehicle ECU 5a displays a warning on the monitor 12 and the mobile terminal 6 that grass has become clogged, applies a pulse signal to the piezoelectric vibration plate 2o of the alarm device to sound a buzzer, and stops the drive of the driving motor 2g, thereby stopping the traveling vehicle body 2.

This prevents the grass from becoming clogged and the lawnmower 1 from continuing to run while scattering grass clippings on the field.

The present invention is not limited to the above embodiments, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these are also included within the scope of the present invention.

For example, in the embodiment shown in Figures 1 to 10, as shown in Figure 9, the mowing height H2 is configured to be changed with priority, but the working speed V may be changed with priority, or the actual mowing width B may be changed with priority.

In the embodiment shown in Figures 1 to 10, the grass clogging prevention unit 5a2 is configured to use a manually input grass density value or density information measured during teaching driving or previous work when calculating the grass clogging index G, but it may also be configured to manually drive the grass cutter 1 in the field to be worked on for a certain period of time before mowing work (specifically, when the working conditions are input or before), measure the grass density during that time based on the magnitude of the load on the engine 2d, and calculate the grass clogging index G using the measured density value.

Furthermore, in the embodiment shown in Figures 1 to 10, the vehicle is configured to automatically travel while controlling the drive of the travel motor 2g with the working speed V set prior to starting the grass mowing operation by automatic driving as the target vehicle speed, but during grass mowing operation by automatic driving under the set working conditions (working speed V or V', mowing height H2, H2' or H2'', actual mowing width B or B'), the grass density may be measured based on the engine load at predetermined time intervals, and the value of the grass clogging index G may be updated each time using that density, and when the grass clogging index G becomes equal to or greater than the grass clogging danger value Gp, the vehicle speed V may be automatically reduced so that the grass clogging index G becomes less than the grass clogging danger value Gp.

Since the grass density varies from place to place within the field being worked on, by changing the vehicle speed V (= working speed) during automatic driving in this way in response to the ever-changing grass density, it is possible to effectively prevent grass clogging.

In addition, when the density D value is updated at each location in the field and the grass clogging index G becomes equal to or exceeds the grass clogging danger value Gp, the mowing height H2 may be changed instead of or in addition to the vehicle speed V.

In this case, for example, the vehicle speed and mowing height are calculated according to the density updated each time, using the procedure for manual operation in FIG. 9. After that, the travel motor 2g is controlled with the calculated vehicle speed as the target vehicle speed, and the DC motor 3g2 is driven to change the height position of the pair of blades 3a1 to achieve the calculated mowing height. This effectively prevents grass clogging, prevents a large sacrifice in vehicle speed, and balances the vehicle speed and mowing height. The actual mowing width B is fixed to a value set before work begins. It is also desirable to configure the density measured at each location in the field to be linked to location information and stored in the storage device 5a1.

In addition, in the embodiment shown in Figures 1 to 10, the grass jam prevention unit 5a2 is configured to calculate and propose one working condition as shown in Figure 10, but it may be configured to calculate and propose multiple working conditions.

For example, the first suggestion is a working condition in which the mowing height is increased by a specified length or a specified percentage, the second suggestion is a working condition in which the working speed is reduced, and the third suggestion is a working condition in which the actual mowing width is narrowed. This makes it possible to prevent grass clogging in the conveying path 8 to the grass collection container 4, and allows the worker to easily select which working condition to compromise on among the mowing height, working speed, and actual mowing width.

Furthermore, in the embodiment shown in Figures 1 to 10, if the grass clogging index G calculated based on the working conditions input on the working conditions input screen (see Figure 8) is equal to or greater than the grass clogging danger value Gp, working conditions in which the mowing height H2 is adjusted higher are proposed. However, a threshold value may be set for the mowing height H3 calculated from the input current grass height H1 and mowing height H2, and if the grass clogging index G is equal to or greater than the grass clogging danger value Gp and the mowing height H3 is equal to or greater than the threshold value, working conditions in which mowing is performed in two stages are proposed.

In this case, when the cut grass height H3 is equal to or greater than the threshold value, the system calculates conditions for increasing the cutting height H2 so that the cut grass height H3 during the first mowing operation is half the height of the cut grass height under the input conditions, and displays the calculated conditions on the mobile device 6.

Specifically, the value calculated by "(current grass height H1 + mowing height H2)/2" or an approximation thereof is displayed on the mobile terminal 6 as the mowing height H2 during the first mowing operation. Then, the mowing height H2 during the second mowing operation is displayed on the mobile terminal 6 as the inputted mowing height.

In other words, in the first mowing operation, half the grass height desired by the worker is mowed, and in the second mowing operation, the system suggests working conditions to the worker to mow the grass to the desired height.

When mowing is done in two steps like this, the grass length is cut in half, making it easier for the grass to be blown away by the wind, and the volume of the grass is halved, effectively preventing grass clogging in the conveyor path 8.

However, on the other hand, this means that mowing work will be performed twice for each location in the field, which will increase the work time. For this reason, when dividing the work into two parts, it is desirable to calculate and propose a work speed that will be the maximum work speed within the range where the grass clogging index G is less than Gp. By configuring in this way, it is possible to effectively prevent grass clogging while shortening the overall work time as much as possible. Note that the work speed does not have to be the maximum value, and may instead be the work speed input by the worker.

On the other hand, if the grass clogging index G is equal to or greater than the grass clogging risk value Gp, and the mowing height H3 calculated from the input current grass height H1 and mowing height H2 is less than the threshold value, the system may be configured to suggest working conditions using the procedure shown in FIG. 9, but it may also be configured to leave the mowing height H2 as is as input, and calculate working conditions by adjusting the actual mowing width B and working speed (vehicle speed) and display them on the mobile terminal 6.

In this case, by configuring the system to search for values for the working conditions in a stepwise manner, the actual cutting width B is narrowed to 3/4 of the blade cutting width A until the grass clogging index G becomes less than the grass clogging danger value Gp, then (if still above Gp) the working speed V is reduced by a predetermined speed or a predetermined percentage to V', (if still above Gp) the working speed V' is reduced by a predetermined speed or a predetermined percentage, (if still above Gp) the actual cutting width B is narrowed to 2/4, and so on, it is possible to balance the actual cutting width and working speed while suppressing grass clogging.

In this way, by setting a threshold value for the cut grass height H3 and configuring the system to suggest two mowing sessions only when the cut grass height H3 is equal to or greater than the threshold value, two mowing sessions are suggested only when there is a high possibility of grass clogging, and one mowing session is suggested otherwise, preventing the work time from being extended.

In the embodiment shown in Figures 1 to 10, the work condition input screen (see Figure 8) is configured to allow input of the current grass height H1, cutting height H2, work speed V, and grass density D, but in addition to these conditions, it may also be configured to allow input (selective input) of the actual cutting width B condition, as shown in Figure 10.

Furthermore, in the embodiment shown in Figures 1 to 10, the work condition input screen shown in Figure 8 and the condition change proposal screen shown in Figure 10 are configured to allow the input of a numerical value for the work speed, but the work speed may be configured to be selectively input in the same way as the mowing width and density values.

In addition, in the embodiment shown in Figures 1 to 10, it is determined whether the calculated grass clogging index G is equal to or greater than the grass clogging risk value Gp, which is a reference value (threshold value), and if it is equal to or greater than the grass clogging risk value Gp, a message indicating that there is a high possibility of grass clogging is displayed on the condition change proposal screen (see Figure 10). However, it is also possible to set a certain reference value Gp1 and a Gp2 lower than the reference value Gp1, and to display a message indicating that there is a high possibility of grass clogging if the calculated grass clogging index G is equal to or greater than the reference value Gp1, and to display a message indicating that there is a possibility of grass clogging occurring if the grass clogging index G is equal to or greater than the reference value Gp2 but less than Gp1.

On the other hand, if the grass clogging index G is less than the reference value Gp2, it is recognized that there is a low possibility of grass clogging occurring, so it is desirable to set the input work conditions as work information and move on to grass cutting work.

Furthermore, in the embodiment shown in Figures 1 to 10, when the radio button r2 (see Figure 8) displayed on the mobile terminal 6 is operated, the grass jam prevention unit 5a2 is configured to search for a field having field shape information including the position information of the vehicle body 2 acquired by the positioning device 9, read out the information on the grass density D linked to the corresponding field, and display it on the mobile terminal 6. However, it is not necessarily necessary to identify the field based on the position information of the vehicle body 2. The mobile terminal 6 may be configured to display a list of fields and allow the worker to select a field for inputting the grass density D, and if the field to be worked on is not included in the list, a predetermined value (e.g., 0.15 [g/ ^cm3 ]) is automatically input as the density D.

In the embodiment shown in Figures 1 to 10, the grass density measuring unit 5a3 is configured to measure the grass density D based on the detection signal of the load on the engine 2d during the teaching run performed prior to the automatic mowing operation and during normal mowing operation performed by manual driving. However, it may also be configured to perform the mowing operation by manual or automatic driving for a certain period of time before the actual mowing operation (specifically, at or before the time of inputting the working conditions), and measure the density D based on the load on the engine 2d.

Furthermore, in the embodiment shown in Figures 1 to 10, the control unit 5 is configured to display various screens, information, warnings, etc. on the monitor 12 and mobile terminal 6, which are examples of the display unit of the present invention, but these display contents may be configured to be displayed on either the monitor or the mobile terminal.

Reference Signs List 1 Grass cutter 2 Traveling vehicle body 3 Grass cutter 4 Grass collection container 5 Control unit 6 Portable terminal 7 Blower 8 Conveyor path 9 Positioning device 10 Work start switch 11 Automatic input field 12 Monitor

Claims (6)

A grass cutter that performs grass cutting work while traveling in a field,
A running vehicle body,
A grass cutting device attached to the traveling vehicle body;
A grass collection container for storing grass cut by the grass cutting device;
A conveying path extending from the grass cutting device to a grass collection container;
an input device for inputting various work conditions;
A display unit capable of displaying various information;
A control unit that controls the display of the display unit,
The control unit includes a grass jam prevention unit that suppresses grass jamming in the transport path, and a storage device that stores various information.
the input device receives input of information on a work speed indicating a vehicle speed during mowing work, a current grass height which is the grass height before mowing work, a mowing height which is a target height after mowing work, and a density of grass to be mowed;
The grass jam prevention unit calculates a grass jamming index using the following formula from information on the working speed, current grass height, mowing height, and grass density input from the input device, and information on the working width of the grass mowing device input from the input device or stored in the memory device, and if this calculated grass jamming index is equal to or greater than a predetermined value, calculates revised working condition proposals by adding or subtracting at least one numerical value of the mowing height, working speed, and working width so that the calculated grass jamming index is less than the predetermined value, and displays the calculated revised working condition proposals on the display unit.
(Equation 1)
Grass clogging index = working width x working speed x (current grass height - cutting height) x grass density The grass trimmer according to claim 1, characterized in that the grass clogging prevention is configured such that, when the calculated grass clogging index is equal to or greater than a predetermined value, the modified working condition proposal is calculated with priority given to the mowing height, among the values of the mowing height, working speed, and working width, and the modified working condition proposal is displayed on the display unit. The control unit includes a vehicle speed suppression unit that warns of an excessive vehicle speed of the traveling vehicle body,
The grass mower according to claim 1 or 2, characterized in that the vehicle speed suppression unit is configured to obtain information regarding the vehicle speed of the traveling vehicle body during grass mowing operation, and to output a warning on the display unit when the vehicle speed during grass mowing operation exceeds a working speed input from the input device and set. A positioning device for acquiring position information of the traveling vehicle body,
The control unit has a route calculation unit that calculates a planned driving route including a plurality of straight routes formed in a straight line and a turning route that turns from each straight route to an adjacent straight route, and an automatic driving unit that automatically drives the traveling vehicle body along the planned driving route calculated by the route calculation unit,
The route calculation unit is configured to calculate a planned travel route after teaching travel based on field shape information acquired by teaching travel by manual driving, and
The grass jam prevention unit is configured to be able to set information on the working speed, current grass height, mowing height, and grass density input from the input device, and is configured to update the set numerical information on the mowing height, working speed, and working width based on the calculated revised working condition proposal by a predetermined operation, and further, when the numerical information on the working width input and set by the input device is updated and decreased,
3. The grass mower according to claim 1, wherein the route calculation unit corrects the planned travel route calculated after teaching travel to a new planned travel route in which straight routes are narrowed by a predetermined interval. The grass cutting device is configured to be driven by rotational power output from an engine of the traveling vehicle body,
The input device is configured to select, as a method for inputting grass density, a manual input for inputting a density value and an automatic input for reading and inputting pre-stored density information,
A grass mower as described in claim 4, characterized in that when the automatic input is selected, information on grass density measured based on the magnitude of the load on the engine in the field to be worked on is read from a storage device and automatically input, and if the information on the grass density to be measured is not stored in the storage device, a predetermined value pre-stored in the storage device is read and automatically input. The control unit is configured to measure grass density at predetermined time intervals based on the magnitude of the load on the engine while the automatic driving unit is performing a grass mowing operation,
The grass clogging prevention unit calculates a grass clogging index using a newly measured grass density value every time the grass density is measured,
A grass cutter as described in claim 5, characterized in that when the grass clogging index reaches or exceeds a predetermined value, the vehicle speed of the traveling vehicle body is controlled to be low and/or the mowing height is changed to be high until the grass clogging index falls below the predetermined value.