WORK VEHICLE

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Japanese Patent Application No. 2024-200384 filed on Nov. 18, 2024. The entire contents of this application are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to work vehicles.

2. Description of the Related Art

A technique to adjust the rotation speed of an engine in a work vehicle is known. For example, Japanese Laid-Open Patent Publication No. 2022-26000 discloses a technique of adjusting the rotation speed of the engine and performing an operation corresponding to a screen displayed on a display device with one dial to receive a rotation operation and a pressing operation.

Specifically, first, an engine operation function is assigned to the dial in response to a key switch that starts the engine being turned on. In this state, a user rotates the dial to adjust the rotation speed of the engine.

Next, the screen operation function is assigned to the dial according to the operation of the assignment change switch. When a user rotates the dial in this state, a cursor displayed on the display device moves on a plurality of item selection units. Then, the selection of the item selection unit is determined when the user performs a pressing operation on the dial.

As described above, in the technique of Japanese Laid-Open Patent Publication No. 2022-26000, one dial is commonly used for both the rotation operation to adjust the engine rotation speed and the rotation operation for selecting an item. The technique of Japanese Laid-Open Patent Publication No. 2022-26000 thus suppresses an increase in the number of components of the operation device.

SUMMARY OF THE INVENTION

In the technique of Japanese Laid-Open Patent Publication No. 2022-26000, the engine rotation speed is adjusted by a rotation operation of a dial. The engine rotation speed is a value related to driving of the vehicle, and should be designed considering fail-safe. However, Japanese Laid-Open Patent Publication No. 2022-26000 does not disclose an operation when the dial fails.

Example embodiments of the present invention provide work vehicles with higher safety.

A work vehicle according to an example embodiment of the present disclosure operates an implement by a drive source and includes a dial configured to output a rotation operation received from a user as a pulse waveform including a low level and a high level, and a controller configured or programmed to set a rotation speed of the drive source, in which the controller is configured or programmed to perform rotation speed control to set the rotation speed according to the pulse waveform, and protection control to set the rotation speed to a predetermined rotation speed when an output of the dial does not form the pulse waveform.

According to example embodiments of the present disclosure, the safety of work vehicles is further improved.

The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a functional configuration of a work vehicle according to an example embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a manual controller according to an example embodiment of the present invention.

FIG. 3 is a flowchart illustrating a portion of processing performed by the work vehicle.

FIG. 4 is a subroutine illustrating details of a dial output monitoring step of FIG. 3.

FIG. 5 is a flowchart illustrating another portion of the processing performed by the work vehicle.

FIG. 6 is a flowchart illustrating another portion of the processing performed by the work vehicle.

FIG. 7 is an example of a home screen displayed on a display device.

FIG. 8 is a time-series graph schematically illustrating the output voltage of the dial.

FIGS. 9A to 9D are schematic diagrams illustrating how setting screens are sequentially displayed on the display device.

FIGS. 10A to 10D are schematic diagrams illustrating a state in which the rotation speed of a drive source is determined to be a default value.

FIGS. 11A and 11B are schematic diagrams illustrating a menu screen displayed on the display device.

FIGS. 12A and 12B are schematic diagrams illustrating a method of displaying a first meter on the home screen.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

Example embodiments of the present disclosure include the following configurations.

(1) A work vehicle according to an example embodiment of the present disclosure operates an implement by a drive source and includes a dial configured to output a rotation operation received from a user as a pulse waveform including a low level and a high level, and a controller configured or programmed to set a rotation speed of the drive source, in which the controller is configured or programmed to perform rotation speed control to adjust the rotation speed according to the pulse waveform, and protection control to set the rotation speed to a predetermined rotation speed when an output of the dial does not form the pulse waveform.

According to a work vehicle of an example embodiment of the present disclosure, the controller is configured or programmed to monitor whether there is an abnormality based on the output of the dial and upon detection of an abnormality, and the controller is configured or programmed to perform the above-described protection control to further improve the safety of the work vehicle.

(2) In the work vehicle according to (1), the dial may be configured to output a voltage higher than a ground level as the low level, and the controller may be configured or programmed to perform the protection control when an output of the dial is a value closer to the ground level than the low level.

When a short circuit to ground or disconnection occurs in the circuit included in the dial, the dial tends to continue to output a value closer to the ground level than the low level. Therefore, the safety of the work vehicle is further improved by the controller performing the protection control when detecting this state.

(3) In the work vehicle according to (1) or (2), the dial may be configured to output, as the high level, a voltage lower than a signal voltage from the controller, and the controller may be configured or programmed to perform the protection control when an output of the dial has a value closer to the signal voltage than the high level.

When a short circuit on the signal voltage side occurs in the circuit included in the dial, the dial tends to continue to output a value closer to the signal voltage than the high level. Therefore, the safety of the work vehicle is further improved by the controller performing the protection control when detecting this state.

(4) In the work vehicle according to any one of (1) to (3), the controller may be configured or programmed to cause a display device to display a current value of the rotation speed when performing the rotation speed control, and cause the display device to display a message indicating that an abnormality has occurred in the dial when performing the protection control.

With this configuration, when no abnormality occurs in the dial, a user can confirm the current value of the rotation speed on the display device during the rotation speed control, and when an abnormality occurs in the dial, a user can similarly confirm the abnormality on the display device. Since the display device is a display that is frequently checked by a user to check the rotation speed, the user can immediately know the abnormality of the dial by causing the display device to display the abnormality of the dial.

Hereinafter, example embodiments of the present disclosure will be described in detail with reference to the drawings.

FIG. 1 is a block diagram illustrating a functional configuration of a work vehicle 1 according to an example embodiment of the present disclosure.

The work vehicle 1 is a vehicle that operates an implement by a drive source 13, and is, for example, a tractor to which an agricultural implement or the like is attached. Specifically, the work vehicle 1 is a small tractor of an entry model (for beginners) designed for a user who operates a tractor for the first time, in which various operation commands are simplified, so that the user can easily use the work vehicle 1. The type of the work vehicle 1 is not particularly limited, and may be a construction work vehicle on which a construction implement such as a crane is attached, in addition to a farmwork vehicle.

A user terminal 2 is, for example, a terminal device managed or owned by a user, and is, for example, a smartphone, a tablet, a notebook computer, or a desktop computer. The user terminal 2 is provided separately from the work vehicle 1. The user terminal 2 includes a display device 21 such as a display. The display device 21 is an output interface to display the state of the work vehicle 1 and various values to a user based on information transmitted from a communication unit 14 described below.

The work vehicle 1 includes an operation device 11, a display device 12, the drive source 13, and the communication unit 14. These units 11 to 14 are electrically connected, for example.

The operation device 11 is usable to select and determine predetermined values related to the operation of the work vehicle 1. The “predetermined values” include, for example, the rotation speed of the drive source 13, the hydraulic pressure of the implement, and the vehicle speed (traveling speed) of the work vehicle 1. In the following description, an example of setting the rotation speed of the drive source 13, as a representative example of the predetermined values, will be described. The operation device 11 includes a manual controller 3 to receive an operation from a user, and a controller 4 that controls each unit of the work vehicle 1.

FIG. 2 is a schematic diagram illustrating the manual controller 3.

The manual controller 3 includes a dial 31 and a plurality of push buttons 32, 33, and 34. The dial 31 is an input interface to receive a rotation operation by the user. When the dial 31 is rotated by a user, a pulse waveform having the low level and the high level is output to the controller 4 the number of times corresponding to the rotation angle.

The plurality of push buttons 32, 33, and 34 are input interfaces to independently receive a pressing operation by a user, and include, for example, a first push button 32 (setting button), a second push button 33 (menu button), and a third push button 34 (return button). These push buttons 32, 33, and 34 are examples, and other buttons may be included in the manual controller 3.

These push buttons 32, 33, and 34 are momentary (self-restoring) buttons that emit an input signal only when pressed by a user. For example, the first push button 32 outputs a low-level signal to the controller 4 when it is not pressed. When a user presses the first push button 32 with his or her finger, the first push button 32 is depressed in response to the pressing by the finger, and outputs a high-level signal to the controller 4. When the user releases the finger from the first push button 32 after that, the depression of the first push button 32 is automatically restored, and the first push button 32 outputs a low-level signal to the controller 4 again.

The controller 4 is a computer device including a processor such as a central processing unit (CPU), a temporary storage memory (main memory) such as a random access memory (RAM), and a nonvolatile memory such as a read only memory (ROM), and is, for example, a micro controller unit (MCU). The controller 4 is configured or programmed to control each unit (for example, the display device 12, the drive source 13, and the communication unit 14) of the work vehicle 1 by causing a processor to perform various calculations and various types of processing in accordance with a computer program stored in a nonvolatile memory. Various types of control performed by the controller 4 will be described below.

The display device 12 is an output interface to display the state of the work vehicle 1 and predetermined values to a user according to the output of the controller 4. The display device 12 includes, for example, a monochrome or color liquid crystal display and a speaker. In addition to these, the display device 12 may include an indicator lamp including a light emitting diode (LED).

The drive source 13 is a rotary device to cause the work vehicle 1 to travel and drives an implement installed on the work vehicle 1. The drive source 13 is, for example, an engine that extracts power from combustion of combustion gas such as light oil or gasoline. The drive source 13 may be an electric motor that extracts power from electric energy.

The communication unit 14 is a communication interface to perform wireless communication with the user terminal 2. The communication unit 14 transmits various types of information to the user terminal 2, for example, according to the output of the controller 4. When receiving the information, the user terminal 2 displays the information on the display device 21. The communication unit 14 may directly communicate with the user terminal 2 by using a short-range wireless communication technology such as Bluetooth (registered trademark), or may communicate with the user terminal 2 by using a mobile communication technology via a base station.

In the following description, the controller 4 is configured or programmed to cause the display device 12 to display various screens. However, the controller 4 may be configured or programmed to cause the display device 21 to display various screens instead of or in addition to the display on the display device 12. That is, at least one of the display devices 12 or 21 functions as a “display device”.

Next, an operation procedure of the work vehicle 1 will be described. In the present example embodiment, the dial 31 is used to adjust the rotation speed of the drive source 13 of the work vehicle 1 and to select various selection items. In particular, since the rotation speed of the drive source 13 is a value related to driving of the work vehicle 1, the dial 31 to adjust the value should be designed in consideration of fail-safe.

For example, when the dial 31 fails, it is necessary to avoid adjustment of the rotation speed of the drive source 13 to an unintended value (in particular, a high value). Therefore, in the present example embodiment, the controller 4 monitors the output voltage Vout of the dial 31, and when an abnormality of the dial 31 is detected based on the output voltage Vout, the rotation speed of the drive source 13 is forcibly set to a safety value (for example, a relatively low rotation speed, such as an idling rotation speed). As a result, it is possible to prevent the rotation speed of the drive source 13 from becoming an abnormal value due to the failure of the dial 31, and it is possible to further improve the safety of the work vehicle 1.

FIG. 3 is a flowchart illustrating a portion of processing performed by the work vehicle 1.

FIG. 4 is a subroutine illustrating details of the dial output monitoring step of FIG. 3.

FIG. 5 is a flowchart illustrating another portion of the processing performed by the work vehicle 1.

FIG. 6 is a flowchart illustrating another portion of the processing performed by the work vehicle 1.

Each step illustrated in FIG. 3 to FIG. 6 is realized by the controller 4 performing various calculations and various types of processing according to a computer program in response to a user's operation or the like. In addition, the order of the steps illustrated in FIG. 3 to FIG. 6 may be changed or any of the steps may be omitted as appropriate as long as inconsistency is not caused.

In the operation device 11, discrete values of the rotation speed of the drive source 13 frequently used in the work vehicle 1 are set in advance as default values 64. These default values 64 are stored in advance in the memory or the like of the controller 4 before a selection and determination operation by a user.

For example, among the rotation speeds of the drive source 13, a mowing rotation speed 3600 n/min is stored as a first default value 64a, a loader rotation speed 3000 n/min is stored as a second default value 64b, and an idling rotation speed 2100 n/min is stored as a third default value 64c, in the memory of the controller 4. These default values 64a, 64b, and 64c are simply referred to as “default values 64” when they are not distinguished.

First, a user turns on a key switch of the work vehicle 1. As a result, the controller 4 detects that the key switch is turned on and starts the drive source 13 at the idling rotation speed (=2100 n/min) (step S11).

Next, the controller 4 causes the display device 12 to display the home screen 5 (step S12).

FIG. 7 is an example of the home screen 5 displayed on the display device 12.

The home screen 5 includes a body 51 and a tab 52. The body 51 is an area in which main information is displayed to a user, and includes, for example, a first meter 53 indicating a current value of a predetermined value (such as the rotation speed of the drive source 13) in an arc shape, and a second meter 54 indicating the current value in a numerical value. The tab 52 is an area in which an icon for notifying a user of the current state of the work vehicle 1, warning information, or the like is displayed. The tab 52 may display the current time as in the example of FIG. 5.

At the initial stage, since the rotation speed of the drive source 13 is the idling rotation speed, the idling rotation speed is displayed as the current value of the rotation speed on the first meter 53 and the second meter 54 of the home screen 5.

Next, the controller 4 monitors the output voltage Vout of the dial 31 (dial output monitoring step: step S13). Thereafter, step S13 is continued until the key switch of the work vehicle 1 is turned off. That is, even during performing the steps after step S14 to be described below, the controller 4 constantly monitors the output voltage Vout of the dial 31, and when there is an abnormality, the controller 4 performs protection control (step S25) to be described below.

FIG. 8 is a time-series graph schematically illustrating the output voltage Vout of the dial 31. In FIG. 8, the vertical axis represents the output voltage Vout, and the horizontal axis represents time. In a case where the dial 31 does not have abnormality, the dial 31 converts the rotation operation received from a user into a pulse waveform including a low level VL and a high level VH and outputs the output voltage Vout to the controller 4 as illustrated in an area R1.

Here, also in the controller 4, a ground level Vg corresponding to the low level for the operation of the controller 4 and a signal voltage Vs corresponding to the high level for the operation of the controller 4 are set. The ground level Vg is a voltage having no potential difference from a reference potential serving as a reference of the operation of the controller 4, and is 0 V. The signal voltage Vs is also referred to as a “sensor voltage” of the controller 4, and is, for example, 5.0 V.

Then, the low level VL of the dial 31 is a voltage higher than the ground level Vg, and is, for example, 0.5 V. The high level VH of the dial 31 is a voltage lower than the signal voltage Vs, and is, for example, 4.5 V. That is, in a case where the dial 31 has no abnormality, the output voltage Vout output from the dial 31 to the controller 4 forms a pulse waveform, and a voltage range of the pulse waveform is higher than the ground level Vg and lower than the signal voltage Vs as illustrated in FIG. 8.

On the other hand, when there is an abnormality in the dial 31 such as short circuit or disconnection, the output voltage Vout output from the dial 31 to the controller 4 tends to be a constant voltage output that does not form a pulse waveform.

For example, when a short circuit to ground or a disconnection occurs in a circuit included in the dial 31, the dial 31 continues to output a value closer to the ground level Vg than the low level VL (more specifically, the ground level Vg), as illustrated in an area R2 in FIG. 8. Therefore, by setting the intermediate value between the low level VL and the ground level Vg to a first threshold value Vth1, the short-circuit abnormality of the dial 31 can be detected when the output voltage Vout is lower than a first threshold value Vth1. In a case where the low level VL is 0.5 V and the ground level Vg is 0 V, the first threshold value Vth1 is a value of ½ of the sum thereof and is 0.25 V {Vth1=(VL +Vg)/2}, for example.

When a short circuit to 5 V (short circuit on signal voltage side), for example, occurs in the circuit included in the dial 31, the dial 31 continues to output a value closer to the signal voltage Vs than the high level VH (more specifically, the signal voltage Vs), as illustrated in an area R3 of FIG. 8. Therefore, by setting the intermediate value between the high level VH and the signal voltage Vs to a second threshold value Vth2, the disconnection abnormality of the dial 31 can be detected when the output voltage Vout is higher than the second threshold value Vth2. In a case where the high level VH is 4.5 V and the signal voltage Vs is 5.0 V, the second threshold value Vth2 is a value of ½ of the sum thereof and is 4.75 V {Vth2=(VH+Vs)/2}, for example.

In the dial output monitoring step (step S13), the controller 4 first determines whether the output voltage Vout is smaller than the first threshold value Vth1 (step S21). When the output voltage Vout is equal to or more than the first threshold value Vth1 (NO in step S21), the controller 4 then determines whether the output voltage Vout is higher than the second threshold value Vth2 (step S22). Then, when the output voltage Vout is equal to or lower than the second threshold value Vth2 (NO in step S22), the controller 4 determines that the dial 31 has no abnormality, and ends the dial output monitoring step (step S13) without performing the protection control (step S25). Thereafter, step S13 is performed at appropriate timings.

In step S21, when the output voltage Vout is lower than the first threshold value Vth1 (YES in step S21), that is, when the output voltage Vout is a value closer to the ground level Vg than the low level VL, the controller 4 detects short-circuit abnormality in the dial 31 (step S23) and performs the protection control (step S25).

In step S22, when the output voltage Vout is higher than the second threshold value Vth2 (YES in step S22), that is, when the output voltage Vout is a value closer to the signal voltage Vs than the high level VH, the controller 4 detects disconnection abnormality in the dial 31 (step S24) and performs the protection control (step S25).

The protection control is, for example, control to set the rotation speed of the drive source 13 to a predetermined rotation speed that can ensure safety. The predetermined rotation speed is a low rotation speed among the rotation speeds of the drive source 13, such as the idling rotation speed, more specifically, a minimum rotation speed that can be set in a state where the key switch of the work vehicle 1 is on. When the controller 4 detects an abnormality of the dial 31, by automatically setting the rotation speed of the drive source 13 to such a low rotation speed, it is possible to prevent the rotation speed of the drive source 13 from becoming a high value (for example, the mowing rotation speed) not intended by a user due to the abnormality of the dial 31, and it is possible to further improve the safety of the work vehicle 1.

In the protection control, the controller 4 may notify a user of the abnormality of the dial 31 by displaying the state of the dial 31 on the display device 12. For example, when detecting the short circuit of the dial 31 (step S23), the controller 4 may display the abnormality of the dial and a resolving method, which is, for example, “A short circuit has occurred in the dial. Contact the support center. Phone: XXX-XXXX”, on the display device 12, in the protection control. Similarly, when the disconnection of the dial 31 is detected (step S24), the controller 4 may display the abnormality of the dial and the resolving method on the display device 12.

Specifically, for example, when performing rotation speed control described below, the controller 4 causes the display device 12 to display the current value of the rotation speed of the drive source 13 on the first meter 53 and the second meter 54, and when performing the protection control, causes the display device 12 to display a message indicating that an abnormality has occurred in the dial 31 to overlap at least one of the first meter 53 or the second meter 54. Accordingly, when no abnormality occurs in the dial 31, a user can confirm the current value of the rotation speed on the display device 12 when the rotation speed control is performed, and when an abnormality occurs in the dial 31, a user can similarly confirm the abnormality on the display device 12. Since the display device 12 is a display that is frequently checked by a user to check the rotation speed, the user can immediately know the abnormality of the dial 31 by causing the display device 12 to display the abnormality of the dial 31.

In the dial output monitoring step (step S13) illustrated in FIG. 8, step S21 is performed before step S22, but step S22 may be performed before step S21.

In addition, in a case where the output of the dial 31 does not form a regular pulse waveform illustrated in the area R1, it is considered that there is an abnormality in the dial 31 (for example, contact failure). Therefore, the controller 4 may be configured or programmed to determine whether the output voltage Vout forms a pulse waveform by various methods, separately from steps S21 and S22, and perform the protection control in a case where the pulse waveform is not formed. Also in this case, the safety of the work vehicle 1 can be further improved, as described above. For example, the controller 4 may perform the protection control in a case where the output of the dial 31 is not a rectangular waveform but a waveform is distorted from a rectangular shape into a shape such as a sin-shaped waveform (wave-shaped waveform).

FIG. 3 is now referred to. The controller 4 determines whether a user has performed a rotation operation of the dial 31 while the home screen 5 is being displayed (step S14). Since each step after step S14 is performed after the dial output monitoring step (step S13) or during the dial output monitoring step, the steps are performed assuming that there is no abnormality in the dial 31.

When the rotation operation of the dial 31 is performed (YES in step S14), the controller 4 adjusts the rotation speed of the drive source 13 according to the amount of the rotation operation (for example, the number of highs and lows of the pulse waveform) (step S15), and displays the current value of the rotation speed on the first meter 53 and the second meter 54 of the home screen 5 (step S16). A series of control steps from step S14 to step S16 in which the controller 4 adjusts the rotation speed according to the pulse waveform output along with the rotation operation is referred to as the “rotation speed control”.

For example, in a case where the dial 31 is rotated clockwise, the controller 4 adjusts the rotation speed of the drive source 13 to be higher than the current value. Accordingly, the first meter 53 and the second meter 54 gradually increase. On the other hand, in a case where the dial 31 is rotated counterclockwise, the controller 4 adjusts the rotation speed of the drive source 13 to be lower than the current value. Accordingly, the first meter 53 and the second meter 54 gradually decrease.

When a user rotates the dial 31 while the home screen 5 is being displayed, the controller 4 can perform the rotation speed control to adjust the rotation speed of the drive source 13 to any value.

In a case where the rotation operation of the dial 31 is not performed (NO in step S14), the controller 4 determines whether the pressing operation of the first push button 32 (setting button) is performed by a user (step S17). When the pressing operation of the first push button 32 is performed (YES in step S17), the controller 4 performs a series of control steps from step S31 to step S34 illustrated in FIG. 5.

FIG. 5 is now referred to. First, the controller 4 causes the display device 12 to display a setting screen 6 indicating one of the plurality of default values 64 (step S31).

FIGS. 9A to 9D are schematic diagrams illustrating how setting screens 6 are sequentially displayed on the display device 12. The setting screen 6 is one of a first setting screen 6a including the first default value 64a as illustrated in FIG. 9A, a second setting screen 6b including the second default value 64b as illustrated in FIG. 9B, a third setting screen 6c including the third default value 64c as illustrated in FIG. 9C, and a fourth setting screen 6d including a fourth default value 64d as illustrated in FIG. 9D. These setting screens 6a, 6b, 6c, and 6d are simply referred to as “setting screens 6” when they are not distinguished.

On the setting screens 6, as illustrated in FIGS. 9A to 9D, the plurality of default values 64 are not simultaneously displayed in arrangement, but the default values 64 are sequentially displayed one by one, so that a user can easily grasp the default value 64 currently being selected. As a result, the user's operation can be easier.

The setting screens 6 include a body 61 and a tab 62. The body 61 is an area in which one of the default values 64 and name information 63 corresponding to the default value 64 are displayed to a user, and is displayed, for example, in a state of being overlapped on the body 51 of the home screen 5 (pop-up state). The tab 62 is an area in which the same display as the tab 52 of the home screen 5 is performed.

The name information 63 is information displayed together with the default value 64, and is information about the work name of the work vehicle 1 or the state name of the work vehicle 1 performed with the default value 64. For example, on the first setting screen 6a, the work name of the work vehicle 1 “PTO/Mower” is displayed as the name information 63 together with the first default value 64a. On the second setting screen 6b, the second default value 64b and the work name of the work vehicle 1 “Loader” as the name information 63 are displayed, and on the third setting screen 6c, the third default value 64c and the state name of the work vehicle 1 “Idle” as the name information 63 are displayed.

For example, if the name information 63 is not displayed on the setting screen 6, it is necessary for a user to memorize the rotation speed and the like used for various works of the work vehicle 1 in advance, and to select and determine the default value 64 matching the rotation speed. As described above, it is difficult for a beginner user to memorize the rotation speeds suitable for various works of the work vehicle 1, and the operation can be troublesome. On the other hand, with the name information 63 displayed together with the default value 64, a user can select the rotation speed suitable for his/her desired work based on the name information 63, and thus, it is not necessary for the user to memorize the rotation speeds suitable for various works in advance. As a result, the user operation on the operation device 11 can be easier.

Here, on the fourth setting screen 6d, character information “Preset1” is displayed as the name information 63 together with the fourth default value 64d. The fourth default value 64d is a value that can be adjusted by a method to be described below, and is a so-called “user setting value” that is set to any value by a user. Therefore, the character information “Preset1” displayed on the fourth setting screen 6d can also be changed to any character information by a user. As described above, for example, in addition to the default value 64 set in advance by the manufacturer of the work vehicle 1 before shipping the work vehicle 1, the default value 64 (for example, the fourth default value 64d) that is preset by a user after the work vehicle 1 is delivered to the user before the user performs various works may be displayed on the setting screen 6.

In the example of FIGS. 9A to 9D, the name information 63 is character information. However, the name information 63 is not limited thereto, and may be graphic information such as an illustration or a photograph. For example, an illustration of a state where a tractor is mowing may be displayed as graphic information on the first setting screen 6a instead of or together with the character information of “PTO/Mower” as the name information 63.

The display order of the plurality of setting screens 6 is preset and stored in the memory of the controller 4. For example, the display order is set such that the first setting screen 6a is displayed first, the second setting screen 6b is displayed second, the third setting screen 6c is displayed third, and the fourth setting screen 6d is displayed fourth. In the initial state, when the pressing operation of the first push button 32 is performed, the controller 4 causes the display device 12 to display the first setting screen 6a set to be displayed first.

When there is the default value 64 determined by a user in the previous determination, the controller 4 stores the default value 64 in the memory, and displays the setting screen 6 including the default value 64 first according to the first pressing operation of the first push button 32 by the user. For example, when a user has determined the second default value 64b as the rotation speed of the drive source 13 in the previous determination, the controller 4 displays the second setting screen 6b first according to the first pressing operation by the user. Thereafter, the controller 4 sequentially displays the third setting screen 6c second, the fourth setting screen 6d third, and the first setting screen 6a fourth, according to the pressing operation of the first push button 32.

As the work by the work vehicle 1, the same work is usually continued and, for example, the mowing work is performed in the morning, and the mowing work is performed again in the afternoon after a break. When displaying the setting screen 6 on the display device 12, the controller 4 first displays the default value 64 determined in the previous determination, so that the user can reach the setting screen 6 including the default value 64 from the home screen 5 by one pressing operation of the first push button 32. Therefore, the user can select the desired default value 64 by a simpler operation.

The controller 4 determines whether the pressing operation of the first push button 32 is performed for the second time after the pressing operation is performed for the first time in step S17 and before a predetermined waiting time T1 elapses (step S32). The waiting time T1 is, for example, 3 seconds or less, and is, specifically, about 1 to 2 seconds. The starting time of the waiting time T1 may be the time of the first pressing operation of the first push button 32 as described above, or may be the time when the controller 4 displays the first setting screen 6 on the display device 12.

In a case where there is almost no time lag between step S17 and step S31 (for example, in a case where the setting screen 6 is displayed within 0.5 seconds after the pressing operation), the starting time of the waiting time T1 may be either of the above timings. On the other hand, in a case where a time lag may occur between step S17 and step S31 (for example, in a case where the setting screen 6 is displayed for more than 0.5 seconds after the pressing operation), the starting time of the waiting time T1 is preferably the timing when the setting screen 6 is displayed on the display device 12. This is because the time during which the setting screen 6 is actually displayed to a user can be matched with the waiting time T1, so that the user's feeling of the waiting time T1 can be unified.

When the second pressing operation is performed within the waiting time T1 (YES in step S32), the controller 4 causes the display device 12 to display the setting screen 6 to be displayed next (step S33). For example, when the first setting screen 6a is displayed in step S31 and the pressing operation of the first push button 32 is performed within the waiting time T1, the controller 4 displays the second setting screen 6b to be displayed next.

Similarly, when the second setting screen 6b is displayed in step S31 and the pressing operation of the first push button 32 is performed within the waiting time T1, the controller 4 causes the display device 12 to display the third setting screen 6c. In a case where the third setting screen 6c and the fourth setting screen 6d are displayed in step S31 and the pressing operation of the first push button 32 is performed within the waiting time T1, the controller 4 causes the display device 12 to display the fourth setting screen 6d and the first setting screen 6a, respectively. Thereafter, the controller 4 returns to the processing of step S32.

Therefore, when the user performs the pressing operation of the first push button 32 a plurality of times at intervals within the waiting time T1, the controller 4 repeats steps S32 and S33 according to the number of times of the pressing operation, and causes the display device 12 to sequentially display the default values 64 according to the preset display order.

For example, when the user presses the first push button 32 twice at an interval within the waiting time T1 while the first setting screen 6a is being displayed in step S31, the second setting screen 6b is displayed on the display device 12 by the pressing operation for the first time, and then the third setting screen 6c is displayed by the pressing operation for the second time. In this manner, a user can reach the setting screen 6 that displays the desired default value 64 among the plurality of default values 64 from the home screen 5 only by the pressing operation of the first push button 32.

Next, a method for determining the rotation speed of the drive source 13 to be the default value 64 currently displayed on the setting screen 6 will be described. In a state where the setting screen 6 for displaying the default value 64 that is desired by a user is being displayed on the display device 12, the user leaves the manual controller 3 without operating it until the waiting time T1 elapses. As a result, the controller 4 determines that the next pressing operation has not been performed until the waiting time T1 elapses (NO in step S32), and determines the rotation speed of the drive source 13 to be the default value 64 currently displayed on the display device 12 (that is, the currently displayed value) (step S34).

FIGS. 10A to 10D are schematic diagrams illustrating a state in which the rotation speed of the drive source 13 is determined to be the default value 64.

For example, in a case where a user desires the loader work, the user performs one or a plurality of pressing operations to make the second setting screen 6b including the second default value 64b displayed on the display device 12 as illustrated in FIG. 10A. In this state, the user leaves the manual controller 3 without operating it.

While the pressing operation is not performed, the controller 4 displays a seek bar 65 on the currently displayed second setting screen 6b as illustrated in FIG. 10B. The seek bar 65 is displayed, for example, in an area of the second setting screen 6b that does not overlap with the name information 63 or the second default value 64b.

The width of the seek bar 65 represents the waiting time T1. The seek bar 65 includes display of an elapsed time 66 from the previous pressing operation (the pressing operation detected in step S17 or step S32) of the first push button 32 to the current time and a remaining time 67 from the current time to the time when the waiting time T1 elapses. For example, as illustrated in FIGS. 10B and 10C, the elapsed time 66 is displayed as a bar extending from left to right with the lapse of time so as to fill the seek bar 65. The remaining time 67 is displayed as a margin area that is not filled with the elapsed time 66.

The elapsed time 66 and the remaining time 67 may be displayed in other expressions. For example, the elapsed time 66 and the remaining time 67 may be displayed in a “circular progress bar” commonly used as a loading animation. In addition, the elapsed time 66 and the remaining time 67 may be displayed as numerical values instead of a figure such as a bar or together with a figure such as a bar. Instead of displaying both the elapsed time 66 and the remaining time 67, only one of the elapsed time 66 and the remaining time 67 may be displayed.

As illustrated in FIG. 10C, the state in which the seek bar 65 is entirely filled with the elapsed time 66 means that the waiting time T1 has elapsed without performing the pressing operation of the first push button 32 since the previous pressing operation. Therefore, the controller 4 determines the rotation speed of the drive source 13 to be the second default value 64b currently displayed on the display device 12. Then, the controller 4 controls the drive source 13 to adjust the rotation speed of the drive source 13 to the determined value.

As described above, while the pressing operation of the first push button 32 is not performed, the controller 4 causes the display device 12 to display at least one of the elapsed time 66 or the remaining time 67 while the setting screen 6 is being displayed. As a result, the user can grasp how long a user needs to leave the manual controller 3 without operating it to determine the rotation speed of the drive source 13 to be the currently displayed value, by viewing these times 66 and 67, and thus, it is possible to improve the user's feeling of use.

Thereafter, as illustrated in FIG. 10D, the controller 4 automatically shifts the display of the display device 12 from the second setting screen 6b to the home screen 5 without waiting for an operation from the user. After the rotation speed of the drive source 13 is determined to be the default value 64 being displayed, the screen returns to the home screen 5 without requiring the user's operation, so that the user's operation can be made simpler.

According to the above operation procedure, the user can shift the display device 12 from the home screen 5 to the setting screen 6 only by the pressing operation of the first push button 32, and can shift the display to the plurality of setting screens 6 according to the predetermined display order by further performing the pressing operation of the first push button 32. Then, when a user performs no pressing operation in a state where the desired default value 64 is being displayed on the display device 12 (that is, leaves the manual controller 3 without operating it) until the waiting time T1 elapses, the rotation speed of the drive source 13 is determined to be the default value 64. Therefore, a user can select and determine the rotation speed of the drive source 13 by a simpler operation without combining the operations of the dial 31 and the first push button 32.

As described above, in the work vehicle 1, in a state where the home screen 5 is being displayed, the rotation speed of the drive source 13 can be adjusted to any value by gradually increasing or decreasing the rotation speed only by the rotation operation of the dial 31, or the rotation speed of the drive source 13 can be selected and determined from among a plurality of preset default values 64 only by the pressing operation of the first push button 32. As a result, the user needs to operate only the dial 31 in a case where the rotation speed of the drive source 13 is desired to be finely adjusted, and only the first push button 32 in a case where a preset value is desired to be used. Therefore, the user's operation can be made simpler, and the user's feeling of use can be improved.

Next, a procedure of adjusting the default value 64 will be described. As illustrated in FIG. 9D, when a user performs a rotation operation of the dial 31 while the fourth setting screen 6d is being displayed within the waiting time T1, the controller 4 adjusts the fourth default value 64d according to the rotation operation.

For example, when a user rotates dial 31 clockwise while the fourth default value 64d (=2500 n/min) is being displayed on the fourth setting screen 6d, the controller 4 increases the fourth default value 64d according to the rotation amount of the rotation operation. Conversely, when a user rotates the dial 31 counterclockwise, the controller 4 decreases the fourth default value 64d according to the rotation amount of the rotation operation. When the desired default value 64 is reached, the user stops the rotation operation of the dial 31.

After adjusting the fourth default value 64d according to the rotation operation, in a case where the rotation operation of the dial 31 is not performed for a predetermined waiting time T2 after the user stops the rotation operation, the controller 4 determines the fourth default value 64d as the value after adjustment and automatically shifts the display to the home screen 5 without waiting for the user's operation (that is, the processing returns to step S12).

As a result, a user can arbitrarily adjust the default value 64 by himself/herself in the middle of the operation of sequentially displaying the setting screens 6 (steps S32 to S33). Therefore, even when the default value 64 desired by the user is not in the plurality of default values 64, the user can determine the rotation speed of the drive source 13 to be the desired default value 64 by adjusting the default value 64 as desired by the rotation operation of the dial 31 and then leaving the manual controller 3 without operating it. This can improve the user's feeling of use.

Furthermore, the default value 64 once adjusted and determined in the above procedure is stored in the memory of the controller 4. Then, when the first push button 32 is pressed (step S17) and the setting screens 6 are sequentially displayed (steps S32 to S33), the default value 64 adjusted and determined in the above procedure is displayed as the fourth default value 64d included in the fourth setting screen 6d.

Note that the way of adjustment and determination of the default value 64 by the user's rotation operation is not limited to the above example, and for example, the default value 64 may be adjusted to any value by performing a pressing operation on the second push button 33 (menu button) in the manual controller 3 to display a screen to set the default value 64 and then performing the rotating operation of the dial 31 while the screen is displayed. This procedure will be described below.

FIG. 3 is now referred to. In a case where the pressing operation of the first push button 32 is not performed in step S17 (NO in step S17), the controller 4 determines whether the pressing operation of the second push button 33 (menu button) is performed by a user (step S18). When the pressing operation of the second push button 33 is performed (YES in step S18), the controller 4 performs a series of control steps from step S41 to step S46 illustrated in FIG. 6.

FIG. 6 is now referred to. First, the controller 4 causes the display device 12 to display a menu screen 7 indicating a plurality of selection items 73 in arrangement (step S41).

FIGS. 11A and 11B are schematic diagrams illustrating the menu screen 7 displayed on the display device 12. The menu screen 7 is provided in a plurality of levels. For example, when the second push button 33 is pressed once, a first menu screen 7a (the menu screen 7 at the uppermost level) illustrated in FIG. 11A is displayed, and when the first push button 32 is pressed once in a state where a cursor CS1 is placed on the predetermined selection item 73 on the first menu screen 7a, a second menu screen 7b (the menu screen 7 at a lower level) illustrated in FIG. 11B is displayed. These menu screens 7a and 7b are simply referred to as “menu screens 7” when they are not distinguished.

The first menu screen 7a is a screen on which a plurality of selection items 73a, 73b, and 73c (they are simply referred to as “selection items 73” when they are not distinguished) are displayed from top to bottom in a list. The first menu screen 7a includes a body 71 and a tab 72. The body 71 is an area in which the plurality of selection items 73 are displayed to a user. In the body 71, the cursor CS1 is displayed so as to overlap the currently selected one of the selection items 73. The cursor CS1 is displayed as, for example, a frame of a predetermined color (red, yellow, or the like) surrounding the selection item 73. When the number of the selection items 73 is large, a scroll bar may be displayed on the right side of the selection items 73 as illustrated in FIG. 11A. The tab 72 is an area in which the same display as the tab 52 of the home screen 5 is performed.

The selection item 73a (Set time) is usable to perform time setting in the work vehicle 1. The selection item 73b (Preset RPM set) is an item to adjust the “user setting value” of the default value 64. The selection item 73c (Engine start security) is usable to perform security setting at the time of starting the drive source 13. These selection items 73a, 73b, and 73c are examples, and the selection items 73 may include items for performing other setting.

While the first menu screen 7a is being displayed, the controller 4 determines whether a user has performed a rotation operation of the dial 31 (step S42). When the rotation operation of the dial 31 is performed (YES in step S42), the controller 4 moves the cursor CS1 according to the rotation operation, changes the selected item 73 being selected (step S43), and returns to step S42 to wait for the next rotation operation. For example, when the user rotates the dial 31 clockwise, the controller 4 moves the cursor CS1 downward in order of the selection items 73a, 73b, and 73c (alternatively, the selection items 73 move upward while the cursor CS1 maintains the position illustrated in FIG. 11A), and sequentially changes the selection item 73 being selected.

Subsequently, the controller 4 determines whether a user has performed a pressing operation of the first push button 32 (step S44). When the pressing operation of the first push button 32 is performed (YES in step S44), the predetermined setting is determined to be the currently selected selection item 73 (step S45), and upon completion of the setting, the screen automatically returns to the home screen 5 (step S12).

Note that, as illustrated in FIGS. 11A and 11B, in a case where the menu screen 7 has a plurality of levels, the controller 4 may cause the display device 12 to display the second menu screen 7b, which is at a level lower than the first menu screen 7a by the pressing operation of the first push button 32 in step S44.

The second menu screen 7b is a screen to which the display is shifted from the first menu screen 7a when, for example, the selection item 73b is selected and determined and that is a screen to adjust the “user setting value” of the default value 64. The second menu screen 7b includes, for example, a first user setting value 74 a(Preset1) and a second user setting value 74b (Preset2).

For example, when receiving the pressing operation of the first push button 32 from a user in a state where the cursor CS1 selects the first user setting value 74a, the controller 4 sets the first user setting value 74a to be adjustable. Then, when receiving the rotation operation of the dial 31 from the user in this state, the controller 4 increases or decreases the first user setting value 74a according to the rotation operation. When receiving the pressing operation of the first push button 32 from the user again, the controller 4 determines the first user setting value 74a as the adjusted value, and returns to the home screen 5 (step S12).

Here, the third push button 34 (return button) is a button usable to return to the previous screen display as appropriate. For example, the controller 4 determines whether the pressing operation of the third push button 34 is performed while the menu screen 7 is being displayed (step S46). When the pressing operation is not performed (NO in step S46), the controller 4 keeps displaying the menu screen 7.

On the other hand, when the pressing operation of the third push button 34 is performed (YES in step S46), the controller 4 shifts the display to the menu screen 7 at a level upper by one of the currently displayed screen when the menu screen 7 of a lower level is displayed, and shifts to the home screen 5 when the menu screen 7 of the uppermost level is displayed (step S12).

Specifically, when receiving the pressing operation of the third push button 34 from a user while the second menu screen 7b is being displayed, the controller 4 displays the first menu screen 7a. When receiving the pressing operation of the third push button 34 from a user while the first menu screen 7a is being displayed, the controller 4 displays the home screen 5.

As described above, the work vehicle 1 can select and determine various selection items using the dial 31 and the like. As described above, the dial 31 is used to adjust the rotation speed of the drive source 13 and to select various selection items. With the dial 31 described above, the controller 4 monitors whether there is an abnormality based on the output of the dial 31 and upon detection of an abnormality, the controller 4 performs the above-described protection control to further improve the safety of the work vehicle 1.

FIGS. 12A and 12B are schematic diagrams illustrating a method of displaying the first meter 53 on the home screen 5.

For example, when the rotation speed of the drive source 13 is displayed in an arc shape in the first meter 53, the controller 4 generates an image to be displayed as the first meter 53 by performing arithmetic processing for expanding and contracting a gauge (colored area) displayed in the first meter 53 while rotating the gauge in an arc shape in accordance with increase or decrease of the rotation speed.

According to the display method described above, the increase or decrease of the gauge can be expressed smoothly in the first meter 53, so that the user's feeling of use can be improved. On the other hand, since the display method described above requires arithmetic processing in the controller 4, the processing load increases in the controller 4, and in some cases, there is a risk that a lag occurs in gauge increase/decrease in the first meter 53 due to performance degradation such as “processing failure”, which may degrade the user's feeling of use.

In particular, when the work vehicle 1 of the present example embodiment is a small tractor of an entry model, the controller 4 also tends to be configured by a relatively inexpensive low-speed processor and a low-capacity memory, and thus the performance deterioration as described above is likely to occur. Therefore, a display method of first meter 53 that can maintain the user's feeling of use even when the controller 4 having a low specification is used is demanded.

Therefore, as illustrated in FIG. 12A, in the present example embodiment, an arc area 81 of the first meter 53 is divided into a plurality of segments 82, and as illustrated in FIG. 12B, these segments 82 are lit (colored) one by one to express the arc-shaped gauge. In FIG. 12B, the segments 82 which are lit (lit segments 83) are illustrated with a hatching pattern, and the segments 82 which are not lit (unlit segments 84) are illustrated in white.

At this time, a boundary line is not provided between the adjacent lit segments 83, and the plurality of lit segments 83 are lit in the same color. As a result, the user cannot see the boundary of the plurality of lit segments 83, and the plurality of lit segments 83 are visually recognized as one lump. That is, a user visually recognizes the lit segments 83 as one gauge that smoothly increases and decreases, not as the plurality of lit segments 83 that are lit one by one, so that the user's feeling of use can be maintained.

In addition, arithmetic processing involving rotation and expansion and contraction as described above becomes unnecessary, and the gauge can be displayed by the on/off processing of the segments 82, so that the processing load of the controller 4 can be reduced.

Specifically, the arc area 81 is divided into the plurality of segments 82. Note that, although the segments 82 the number of which is 19 are illustrated in FIGS. 12A and 12B, the number of the segment 82 into which the arc area 81 is divided is not particularly limited for implementation of the present disclosure, and the arc area 81 may be divided into more (for example, 40) segments 82. The arc area 81 may be divided into these segments 82 at equal angles, or may be divided at unequal angles such that the angles become smaller from the left side to the right side as illustrated in FIG. 12A.

For example, the lower limit value of the rotation speed of the drive source 13 is “0 n/min” in the key switch off state, and the next value is “1600 n/min” which is the lower limit value of the idling rotation speed. For this reason, a value between 0 n/min and 1600 n/min is not used, and there is little need to display the value as the gauge of the first meter 53. Therefore, in the arc area 81, the segments 82 that are relatively wide are provided in the left area (for example, an area from 0 n/min to 1600 n/min), and the area is expressed with the smaller number of segments 82.

On the other hand, the rotation speed of the drive source 13 tends to be set more finely as the rotation speed is higher. For example, in a case where the initial value of the mowing rotation speed is “3600 n/min”, the user may adjust the mowing rotation speed to “3500 n/min”, “3700 n/min”, or the like with small increments as appropriate according to the state of the lawn or the like. Therefore, it is highly demented to continuously display the first meter 53 with a smooth motion at a higher rotation speed (for example, the loader rotation speed of 3000 n/min or more). Therefore, in the arc area 81, the segments 82 that are relatively narrow are provided in a right area (for example, an area from 3000 n/min to 3800 n/min), and the area is expressed with a larger number of segments 82.

The segments 82 having a medium size are provided in an area indicating a medium rotation speed (for example, an area from the lower limit value 1600 n/min of the idling rotation speed to the loader rotation speed 3000 n/min).

In this manner, by making the plurality of segments 82 narrower in an area that is highly demanded to be displayed in small increments and wider in an area that is not, the total number of the segments 82 is suppressed to a relatively small number, so that the processing load in the controller 4 is reduced, and the user's feeling of use can be maintained by expressing the increase or decrease of the gauge with a smooth motion for a demanded area.

An area 85 at the rightmost of the arc area 81 is an area exceeding the upper limit value (for example, 3800 n/min) of the rotation speed and is an area not used as a gauge. For this reason, the segment 82 is not necessarily provided in the area 85 and may be a margin area.

While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.