JP2023149678A - work vehicle - Google Patents

Abstract

To provide a work vehicle capable of selecting an appropriate shift position during start according to a speed limit state.SOLUTION: One aspect of the present disclosure is a work vehicle, comprising a transmission, and a controller including a processor. The controller determines whether a speed limit state of the work vehicle is in a first speed limit state or a second speed limit state that requires speed limit more than the first speed limit state, and when the speed limit state of the work vehicle is in the second speed limit state, limits a speed range that can be set as a speed range during start, which is a speed range that is applied when starting.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a work vehicle.

2. Description of the Related Art Some work vehicles such as motor graders and bulldozers are equipped with automatic transmissions having a plurality of gears. The automatic transmission of a work vehicle is controlled so that the speed gears are automatically switched according to the vehicle speed and load when performing work such as leveling, excavation, self-propelled transportation, etc. For example, in the automatic transmission device for a bulldozer described in Patent Document 1, when the vehicle starts, the vehicle starts at a speed selected by an operator, and then the speed is changed according to the vehicle speed.

Japanese Patent Application Publication No. 2010-209924

By the way, work vehicles may be provided with a driving mode in which steering is automatically performed, for example, in order to facilitate operation during work. In addition, there may be an operation mode in which the work machine can be steered using a steering control lever or the like provided near the lever of the work machine without operating the steering handle. In such a driving mode, the speed limit state when the work vehicle is traveling may be different from that in the normal driving mode. In this way, in a work vehicle that has multiple driving modes with different speed limits, it is desirable to perform control so that the speed gear is switched to an appropriate gear according to the speed limit state even when starting. was there.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a work vehicle that can select an appropriate shift position at the time of start depending on the speed limit state.

In order to solve the above problems, one aspect of the present disclosure is a work vehicle including a transmission and a controller including a processor, wherein the controller is configured to adjust the speed limit state of the work vehicle to a first speed limit. and a second speed limit state in which a speed limit is required more than the first speed limit state, and determine whether the speed limit state of the work vehicle is at the second speed. This is a work vehicle that limits the speed range that can be set as a starting speed range, which is a speed range that is applied when starting when the vehicle is in a restricted state.

According to the aspect of the present disclosure, an appropriate start shift position can be selected depending on the speed limit state.

FIG. 1 is a schematic diagram showing the configuration of a work vehicle according to an embodiment. FIG. 2 is a block diagram showing a functional configuration for controlling the operation of a transmission in the work vehicle according to the embodiment. FIG. 3 is a diagram illustrating an example of displaying information on a display device of a work vehicle according to an embodiment. FIG. 3 is a diagram illustrating an example of a start shift position, a shift index, and selectable shift positions in each movement mode, which are stored in the controller of the work vehicle according to the embodiment. FIG. 3 is a diagram schematically showing shift positions that can be selected as start shift positions in the controller of the work vehicle according to the embodiment. FIG. 3 is a diagram illustrating an example of setting a start shift position when the driving mode is changed in the controller of the work vehicle according to the embodiment. 3 is a flowchart showing the operation of the controller according to the embodiment. FIG. 7 is a diagram illustrating another setting example of the start shift position when the driving mode is changed in the controller of the work vehicle according to the embodiment. FIG. 7 is a diagram illustrating another setting example of the start shift position when the driving mode is changed in the controller of the work vehicle according to the embodiment.

Embodiments of the present disclosure will be described below with reference to the drawings. In addition, in each figure, the same reference numerals are used for the same or corresponding components, and the description thereof will be omitted as appropriate.

FIG. 1 is a schematic diagram showing the configuration of a work vehicle 10 according to an embodiment.
As shown in FIG. 1, the work vehicle 10 according to the embodiment is, for example, a motor grader. Note that the work vehicle 10 may be a wheeled shovel, a bulldozer, a wheel loader, etc. other than the motor grader.

The motor grader as the work vehicle 10 in this embodiment mainly includes a body frame 11, front wheels 12, rear wheels 13, a driver's cab 14, a work machine 15, a drive machine room 16, and a transmission 18. We are prepared.

The vehicle body frame 11 extends along the longitudinal direction Da of the work vehicle 10. The vehicle body frame 11 supports a driver's cab 14. The vehicle body frame 11 includes a rear frame 11r disposed at the rear in the longitudinal direction Da, and a front frame 11f disposed at the front in the longitudinal direction Da. The rear frame 11r supports the drive unit chamber 16. The front frame 11f is rotatably connected to the rear frame 11r.

The front wheels 12 and the rear wheels 13 are provided at the front and rear of the vehicle body frame 11 in the longitudinal direction Da, respectively. The front wheels 12 and the rear wheels 13 are respectively arranged on both sides of the width direction Dw of the work vehicle 10, which intersects with the longitudinal direction Da within a horizontal plane. The front wheel 12 is rotatably supported by the front end of the front frame 11f. For example, two sets of rear wheels 13 are provided on the rear frame 11r with an interval in the front-rear direction Da.

The work machine 15 includes, for example, a blade 152. For example, the work vehicle 10 can use the blade 152 to perform tasks such as leveling the ground, removing snow, light cutting, and mixing materials.

FIG. 2 is a block diagram showing a functional configuration for controlling the operation of the transmission 18 in the work vehicle according to the present embodiment.
As shown in FIG. 2, the rear wheel 13 is rotationally driven by a drive machine 17 arranged in a drive machine room 16. The driving machine 17 is an engine. The drive machine 17 may be an electric motor. The driving force by the drive machine 17 is transmitted to the axle 13s of the rear wheel 13 via the transmission 18.

The transmission 18 changes the speed of the rotation output from the drive machine 17 and outputs it to the axle 13s. In this embodiment, the transmission 18 is a stepped transmission that can change the gear ratio (speed range) into multiple stages by switching the meshing state of a plurality of gears. Further, the transmission 18 may be a continuously variable transmission, such as a so-called CVT (Continuously Variable Transmission), which can steplessly adjust the gear ratio between the input side and the output side.

The work vehicle 10 is capable of moving forward and backward in the longitudinal direction Da by rotationally driving the rear wheels 13 via the transmission 18 . The transmission 18 is capable of switching the gear ratio in, for example, a plurality of speed ranges (e.g., eight steps) in a speed range (shift position) in each of the forward and reverse directions. In this specification, when the transmission 18 is a stepped transmission, a region responsible for transmitting driving force from the drive machine 17 to the axle 13s at each speed stage is referred to as a speed range. When the transmission device 18 is a continuously variable transmission, a region in which driving force is transmitted from the drive unit 17 to the axle 13s at each speed stage that is set in a pseudo manner in the continuously variable transmission is referred to as a speed range.

The transmission 18 switches the shift position under the control of a controller 30, which will be described later, depending on the traveling speed of the work vehicle 10 detected by the speed sensor 19 during forward movement and backward movement. The transmission 18 performs shift position switching control such that as the absolute value of the traveling speed of the work vehicle 10 increases, the reduction ratio becomes smaller stepwise. The shift position of the transmission device 18 is changed by operating an electromagnetic control valve 18v such as a solenoid valve for performing a speed change operation under the control of the controller 30.

As shown in FIG. 1, the driver's cab 14 is disposed at an intermediate portion of the vehicle body frame 11 in the longitudinal direction Da. As shown in FIG. 2, inside the driver's cab 14, there are a steering wheel 21, a plurality of work equipment levers 22, a steering operation lever 23, a forward/forward (FNR) switching lever 24, and a driving mode switching switch 25. It includes at least an accelerator pedal 26, a shift lever (operating device) 28, a display device 29, and a controller 30.

The steering wheel 21 is arranged in front of a driver's seat (not shown) where an operator of the work vehicle 10 is seated. The steering wheel 21 steers the front wheels 12 by an operator rotating the steering wheel 21 .

The plurality of work machine levers 22 are for operating the work machine 15. The plurality of work machine levers 22 are arranged on both sides (in the width direction) of the operator seated in the driver's seat. The tilting direction of each working machine lever 22 is set, for example, in the front-rear direction, left-right direction, or the like. When the operator tilts each working machine lever 22, the blade 152 of the working machine 15 performs various operations such as vertical movement, forward and backward movement, left and right movement, and tilting. Note that the number and arrangement of the work machine levers 22, and the operation of the work machine 15 when the work machine levers 22 are operated are not limited in any way.

The steering operation lever 23 is arranged near the plurality of work machine levers 22. The steering control lever 23 steers the front wheels 12 by an operator tilting the steering control lever 23 . The steering control lever 23 allows the operator to steer the front wheels 12 without touching the steering wheel 21.

The forward/reverse switching lever 24 switches the rotational direction of the rear wheels 13 to which the driving force of the driving machine 17 is transmitted by operating a transmission 18 to be described later. The forward/reverse switching lever 24 is operated by the operator to select "forward (F)" which transmits the driving force of the drive machine 17 to the rear wheels 13 so that the work vehicle 10 moves forward, and "forward (F)" which transmits the driving force of the drive machine 17 to the rear wheels 13 so that the work vehicle 10 moves forward. The transmission 18 is configured to switch to either "Neutral (N)" which interrupts the transmission of power, or "Reverse (R)" which transmits the driving force of the drive unit 17 to the rear wheels 13 so that the work vehicle 10 moves backward. Outputs commands to.
The accelerator pedal 26 is used to adjust the rotation speed of the drive machine 17 in accordance with an operator's operation, and adjust the traveling speed of the work vehicle 10.

The driving mode changeover switch 25 switches the driving mode of the work vehicle 10 by an operator's operation. In this embodiment, three driving modes of the work vehicle 10 are selectable: "normal mode," "substeering mode," and "autosteering mode."

In the "normal mode", the operator operates the steering wheel 21 to steer the front wheels 12, and the operator operates the accelerator pedal 26 to adjust the traveling speed of the work vehicle 10, and the work vehicle 10 is driven.

In the "substeering mode", the front wheels 12 are steered by the operator's tilting operation of the steering control lever 23, and the work vehicle 10 is driven while adjusting the traveling speed of the work vehicle 10 by the operator's operation of the accelerator pedal 26. let In the "substeering mode", the traveling speed of the work vehicle 10 is limited. In the "substeering mode", the shift positions that can be selected (set) by the transmission 18 when the work vehicle 10 is started are limited under the control of the controller 30, which will be described later.

In the "autosteering mode", the front wheels 12 are automatically steered under the control of a controller 30, which will be described later. In the "autosteering mode", the traveling speed of the work vehicle 10 is limited. In the "autosteering mode", the shift positions that can be selected (set) by the transmission 18 when the work vehicle 10 is started are limited under the control of the controller 30, which will be described later. In the "autosteering mode", the shift positions that can be selected (set) when starting the work vehicle 10 are more limited than in the "substeering mode", and the travel speed limit is set to a lower speed side.

That is, in the "normal mode", the first speed limit state is set in which the control function that requires speed limit is disabled. On the other hand, in the "sub-steering mode" and the "auto-steering mode", the second speed-limiting state is set in which the control function that requires speed-limiting is enabled. In the "substeering mode" and the "autosteering mode", the second speed limit state is set, which is a state in which speed restriction is more necessary than the first speed limit state.

The shift lever 28 allows the shift position in the transmission 18 to be changed by an operator's operation. The shift lever 28 is normally placed at the "0" position where the shift position of the transmission 18 is not changed. By an operator's operation, the shift lever 28 can be switched to "UP" which increases the shift position of the transmission 18, or "DOWN" which decreases the shift position of the transmission 18. When the shift position is changed by the operator's operation of the shift lever 28, the controller 30, which will be described later, changes the gear ratio in the transmission device 18 according to the operation, and in other cases, the controller 30 changes the gear ratio of the transmission device 18. The gear ratio of the transmission 18 is automatically switched according to the speed. Note that switching of the gear ratio of the transmission 18 may be performed only in accordance with the operation of the shift lever 28 by the operator, and may not be performed automatically in accordance with the traveling speed of the work vehicle 10 under the control of the controller 30. It's okay.
Further, when the operator operates the shift lever 28 when starting the work vehicle 10, the controller 30 switches the shift position of the transmission 18 at the time of starting according to the operation of the shift lever 28.

FIG. 3 is a diagram showing an example of information displayed on the display device 29 of the work vehicle 10 in this embodiment.
The display device 29 displays information related to a plurality of functions that the work vehicle 10 has. In this embodiment, as shown in FIG. 3, the display device 29 displays information I1 indicating a start shift position (start speed range), which will be described in detail later.

(Example of controller configuration)
Controller 30 controls the operation of transmission 18.
The controller 30 can be configured using a computer equipped with a processor such as a microcomputer or a CPU (Central Processing Unit), and hardware such as peripheral circuits and peripheral devices of the computer. As shown in FIG. 2, the controller 30 has a functional configuration consisting of a combination of hardware and software such as a program executed by a computer.As shown in FIG. 33, a shift control section 34, and a start setting section 35.

The input/output unit 31 repeatedly inputs operation information of the steering wheel 21, the plurality of work equipment levers 22, the steering operation lever 23, the forward/reverse switching lever 24, the driving mode switching switch 25, and the accelerator pedal 26 at a predetermined period. . The input/output section 31 outputs command information for controlling switching of the shift position of the transmission 18 based on the processing of the shift control section 34, which will be described later. The input/output unit 31 outputs image information, character information, etc. to be displayed on the display device 29.

The setting condition storage section 32 stores various setting conditions used to control the transmission 18. For example, as shown in FIG. 4, the setting condition storage unit 32 stores the shift position (speed Combinations of shift positions at start (speed range at start), which are ranges), and shift indexes S1 to S8, which are index values indicating the combinations of shift positions at start, are stored in association with each other.
In this embodiment, the setting condition storage unit 32 includes, for example,
1 forward gear (F1)/1 reverse gear (R1): shift index S1,
1st forward gear (F1)/2nd reverse gear (R2): shift index S2,
1 forward gear (F1)/3 reverse gears (R3): shift index S3,
2 forward speeds (F2)/2 reverse speeds (R2): shift index S4,
2 forward speeds (F2)/3 reverse speeds (R3): shift index S5,
3 forward gears (F3)/2 reverse gears (R2): shift index S6,
3 forward gears (F3)/3 reverse gears (R3): shift index S7,
3 forward gears (F4)/2 reverse gears (R2): shift index S8,
I remember it in association with.

Further, the setting condition storage unit 32 stores a plurality of starting shifts shown in FIG. Information indicating whether or not a combination of positions (shift indexes S1 to S8) is selectable is stored. In FIG. 3, "○" indicates that the shift position at the time of starting can be selected in each driving mode, and "x" indicates that the shift position at the time of starting cannot be selected.
In this embodiment, in the "normal mode", the speed limit control that limits the speed at the time of starting is not applied, and all of the shift indexes S1 to S8 are selectable as shift positions at the time of starting.
In the "substeering mode", shift index S8 is subject to speed limit control, and shift indexes S1 to S7 can be selected as shift positions at the time of starting.
In the "autosteering mode", shift indexes S3, S5 to S8 are subject to speed limit control, and only shift indexes S1, S2, and S4 can be selected as shift positions at the time of starting.

The state storage unit 33 stores operation information of the steering wheel 21, the plurality of work equipment levers 22, the steering operation lever 23, the forward/reverse switching lever 24, the driving mode switching switch 25, and the accelerator pedal 26, which are input to the input/output unit 31. (operation status) is memorized. The state storage unit 33 temporarily stores the most recently set start shift position. Furthermore, when the shift position at start is changed by the operator's operation of the shift lever 28, the state storage unit 33 stores the changed shift position at start. In this embodiment, the state storage unit 33 stores the index value of the shift index corresponding to the start shift position.

The shift control unit 34 controls the switching operation of the shift position in the transmission 18 by controlling the operation of the electromagnetic control valve 18v. When the work vehicle 10 is started, the shift control section 34 switches the shift position (speed stage) of the transmission 18 according to a start shift position set by a start setting section 35, which will be described later. After the work vehicle 10 starts, the shift control unit 34 changes the shift position of the transmission 18 according to the traveling speed of the work vehicle 10 detected by the speed sensor 19, the load on the work vehicle 10, and the like. The shift control unit 34 changes the shift position of the transmission 18 according to the traveling speed of the work vehicle 10, the load on the work vehicle 10, etc. based on a preset shift control map or the like. Note that the shift control unit 34 may change the shift position of the transmission device 18 only in accordance with the operation of the shift lever 28 by the operator, and may change the shift position of the transmission device 18 only in accordance with the operator's operation of the shift lever 28, and may change the shift position in accordance with the traveling speed of the work vehicle 10, the load on the work vehicle 10, etc. It is not necessary to change the shift position of the device 18. Here, the contents of the shift control of the transmission device 18 by the shift control section 34 after the work vehicle 10 starts are not specifically limited.

The start setting section 35 sets a start shift position according to the driving mode of the work vehicle 10 when the work vehicle 10 starts. The start setting section 35 sets the start shift position based on the shift position (see FIG. 4) that is stored in the setting condition storage section 32 and can be selected as the start shift position for each driving mode.

The start setting unit 35 executes the process of setting the start shift position only when the work vehicle 10 is stopped. In this embodiment, only when the forward/reverse switching lever 24 is in "neutral (N)" and the work vehicle 10 is in a stopped state, the process of setting the start shift position is executed. Here, the stopped state is a case where the traveling speed of the work vehicle 10 detected by the speed sensor 19 is 0, and in this embodiment, a case where the speed sensor continuously detects a speed of less than 1 km/h for 0.5 seconds or more , the traveling speed of the work vehicle 10 is set to 0.

As shown in FIGS. 4 and 5, when the driving mode of the work vehicle 10 is the "normal mode" which is the first speed limit state in which the control function that requires speed limit is disabled, the start setting unit 35 One of the shift positions from shift indexes S1 to S8 is selected and set as the shift position at the time of starting. When the driving mode of the work vehicle 10 is the "substeering mode", which is a second speed limiting state in which the control function that requires speed limiting is effective, the start setting unit 35 selects one of the shift indexes S1 to S7. Select one of the shift positions and set it as the shift position when starting. When the driving mode of the work vehicle 10 is the "autosteering mode", which is a second speed limit state in which the control function that requires speed limit is effective, the start setting unit 35 selects one of the shift indexes S1, S2, and S4. Select one of the shift positions from , and set it as the shift position when starting.

When the driving mode of the work vehicle 10 is changed, the starting setting unit 35 sets a starting shift position according to the changed driving mode. For example, if the shift position set when starting during "normal mode" is outside the shift position that can be set during "substeering mode" or "autosteering mode", "substeering mode" or " Select one of the shift positions that can be set during "Autosteering Mode" and reset it as the shift position when starting. Specifically, when the driving mode after the change is the "substeering mode", the start setting unit 35 sets the starting shift position that was set in the "normal mode" immediately before the change to the "substeering mode". If the shift position F4/R2 corresponds to a shift index other than the selectable shift index S1 to S7, that is, the shift index S8, select the shift position corresponding to any one of the shift indexes S1 to S7, and set the shift position at the time of departure. Set as . In addition, when the driving mode after the change is the "auto steering mode", the start setting section 35 sets the start shift position that was set during the "normal mode" or "substeering mode" immediately before the change to the "auto steering mode". If the shift position corresponds to a shift index other than selectable shift indexes S1, S2, and S4 during "autosteering mode", that is, shift indexes S3, S5 to S8, the shift position corresponds to one of shift indexes S1, S2, and S4. Select a position and set it as the shift position when starting.

Further, the start setting section 35 sets the forward (F) side position value and the reverse (R) side position value among the shift positions that can be set during the "sub steering mode" or the "auto steering mode". , the shift position at the time of start is set so that the position value is equal to or less than the upper limit of the position value determined corresponding to the "sub-steering mode" or the "auto-steering mode". Further, the start setting section 35 sets the forward side and reverse side position values among the shift positions that can be set during the "substeering mode" or the "autosteering mode" during the "normal mode". The shift position at the time of starting is set so that it is equal to or less than each position value of the set shift position at the time of starting.
Specifically, as shown in FIG. 6, if the starting shift position set in the "normal mode" immediately before the change was F4/R2 of shift index S8, the forward side shift position in the "normal mode" The position value is 4, and the position value on the reverse side is 2. Therefore, when the changed driving mode is "substeering mode", the start setting unit 35 sets the upper limit value of the forward position value to 4 among the shift indexes S1 to S7, as shown in FIG. Below, shift index S6 (F3/R2) where the upper limit value of the position value on the reverse side is 2 or less and which is close to the position value of the shift position at the time of starting set in "normal mode" is set to the shift position at the time of starting. Set as . Additionally, as shown in Fig. 6, when the driving mode is changed from "substeering mode" to "autosteering mode", the upper limit of the forward position value of shift indexes S1, S2, and S4 is 3 or less. Then, the upper limit of the position value on the reverse side is 2 or less and the shift index S3 (F2/R2) that is close to the position value of the shift position at the time of starting set in "sub steering mode" is set to the shift position at the time of starting. Set as .

Further, when the shift lever 28 is operated by the operator, the start setting unit 35 forcibly sets one of the plurality of shift positions as the start shift position based on a command signal from the shift lever 28. Set. When the shift lever 28 is operated to raise the shift position at the time of starting (UP), the shift position is changed in the direction in which the index value increases in the order of shift indexes S1 to S8. When the shift lever 28 is operated to DOWN the shift position at the time of starting, the shift position is changed in the direction in which the index value decreases in the order of shift indexes S8 to S1. At this time, if the driving mode is the "substeering mode" or "autosteering mode", which is the second speed limit state in which the control function that requires speed limit is effective, the start setting unit 35 sets the "substeering mode" to "substeering mode" or In "Steering mode" and "Auto steering mode", index values that cannot be selected are skipped and up and down operations are performed.

Further, when the operation to change the driving mode is performed while the work vehicle 10 is traveling, the start setting unit 35 stores the changed driving mode in the state storage unit 33. When the above-mentioned position of the forward/reverse switching lever 24 is "neutral (N)" and the work vehicle 10 is in the stopped state, the start setting section 35 stores the changed state from the state storage section 33. Calls the driving mode and executes the process of resetting the shift position when starting.

(Flow of processing by controller)
FIG. 7 is a flowchart showing the operation of the controller 30 according to the embodiment.
As shown in FIG. 7, the controller 30 repeatedly executes a series of processes described below at preset time intervals.

First, the start setting section 35 of the controller 30 determines whether the forward/reverse switching lever 24 is in "neutral (N)" and the work vehicle is in a stopped state (step S101). In step S101, if it is determined that the position of the forward/reverse switching lever 24 is not "neutral (N)" or that the work vehicle is not in a stopped state (step S101: No), the start setting unit 35 executes the process. finish. In step S101, if it is determined that the forward/reverse switching lever 24 is in the "neutral (N)" position and the work vehicle is in a stopped state (step S101: Yes), the start setting unit 35 In order to set the hour shift position, information on the currently selected driving mode of the work vehicle 10 is acquired with reference to the state storage unit 33 (step S102).

Next, the start setting section 35 refers to the state storage section 33 and determines whether the current driving mode of the work vehicle 10 has changed from the driving mode set immediately before (step S103). In step S103, if it is determined that the current driving mode of the work vehicle 10 has not changed from the driving mode set immediately before (step S103: No), the start setting unit 35 sets the driving mode in the current driving mode. The shift position at the time of start is maintained (step S104).
Further, if it is determined in step S103 that the current driving mode of the work vehicle 10 has changed from the driving mode set immediately before (step S103: Yes), the start setting unit 35 stores the state storage unit 33 in the state storage unit 33. A stored start shift position is selected (step S105).

After completing step S104 or S105, the start setting unit 35 determines whether or not the operator operates the shift lever 28 (step S106).
If it is determined that the operator has not operated the shift lever 28 (step S106: No), the start setting section 35 determines whether the start shift position selected in step S104 or step S105 is selected at that time. The shift position at the time of start is set so that the shift position corresponds to the current driving mode (step S107). For example, if the driving mode at that time is "substeering mode" or "autosteering mode", the start setting section 35 sets the shift that can be set in "substeering mode" or "autosteering mode". Among the positions, the position value on the forward (F) side and the position value on the reverse (R) side are both the upper limit of the position value determined corresponding to "substeering mode" or "autosteering mode" Set the shift position at start as shown below. Furthermore, among the shift positions that can be set during the changed "substeering mode" or "autosteering mode," both the forward and reverse position values will be the same as those set during the "normal mode" before the change. The shift position at the time of starting is set so that it is equal to or less than each position value of the shift position at the time of starting.

Further, if it is determined that the shift lever 28 has been operated by the operator (step S106: Yes), the start setting section 35 selects a shift lever position from among the shift positions that can be set in the driving mode selected at that time. 28, the shift position at the time of starting is reset (step S108).
The start setting section 35 stores the start shift position reset in step S108 in the state storage section 33 as a new start shift position in all driving modes (step S109).

In this way, a series of settings of shift positions at the time of starting in the controller 30 are completed.

FIG. 8 is a diagram showing another setting example of the start shift position when the driving mode is changed in the controller 30 of the work vehicle 10 according to the embodiment.
As shown in FIG. 7, when the controller 30 repeatedly executes the start shift position setting process, when changing from the "normal mode" to the "autosteering mode", the state storage unit 33 is stored in step S105. The index value of the shift index corresponding to the stored start shift position (in the example of FIG. 8, shift index S7:F3/R3) is selected. In subsequent step S107, F2/R2 of the shift index S4 is set as the shift position at the time of start, corresponding to the "autosteering mode" which is the changed driving mode. Thereafter, when the driving mode is changed from "autosteering mode" to "normal mode", the start setting section 35 selects the shift index S7 stored in the state storage section 33, and the start shift position is changed. will be reset.

Further, FIG. 9 is a diagram showing still another setting example of the start shift position when the driving mode is changed in the controller 30 of the work vehicle 10 according to the embodiment. As shown in FIG. 9, when the "normal mode" is changed to the "autosteering mode", in step S105, the index value of the shift index ( In the example of FIG. 9, shift index S7:F3/R3) is selected. Thereafter, in the "autosteering mode", when the shift position at the time of starting is set, for example, F1/R2 of shift index S2, by the operator's operation of the shift lever 26, the shift position at the time of starting set in step S108 is set to the state. It is stored in the storage unit 33.
Furthermore, after that, change from "Autosteering mode" to "Normal mode" and "Normal mode"
Even if the mode is changed to "autosteering mode", the start shift position stored in the state storage section 33 is selected in step S105, and the shift index S2 is set in the subsequent step S107.

(action/effect)
According to the present embodiment, it is possible to select an appropriate start shift position depending on the speed limit state of the work machine 100.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to the above-described embodiments, and may include design changes without departing from the gist of the present invention.

For example, in the above-described embodiment, the sub-steering mode and the auto-steering mode are exemplified as driving modes that require a speed limit compared to the normal mode. It can be replaced.
Further, although examples of selectable shift positions have been shown in each driving mode, other shift positions can be selected as the starting shift position as appropriate.

Furthermore, part or all of the program executed by the computer in the above embodiments can be distributed via a computer-readable recording medium or a communication line.

10...Work vehicle 18...Transmission device 27...Shift lever (operating device) 30...Controller

Claims (6)

A work vehicle,
a transmission and
a controller including a processor;
Equipped with
The controller includes:
Determine whether the speed limit state of the work vehicle is in a first speed limit state or a second speed limit state, which is a state where a speed limit is more necessary than the first speed limit state. ,
When the speed limit state of the work vehicle is in the second speed limit state, a speed range that can be set as a speed range at start, which is a speed range applied at the time of start, is limited;
work vehicle. The controller includes:
When changing from the first speed limit state to the second speed limit state, the starting speed range set during the first speed limit state can be set during the second speed limit state. If the speed is outside the speed range, the set start speed range is reset to one of the speed ranges that can be set during the second speed limit state.
The work vehicle according to claim 1. The controller includes:
Of the speed ranges that can be set during the second speed limit state, both a position value indicating a speed range when moving forward and a position value indicating a speed range when moving backward correspond to the second speed limit state. Resetting the speed range to a speed range that is below the upper limit determined by
The work vehicle according to claim 2. The controller includes:
Among the speed ranges that can be set during the second speed limit state, both the position value indicating the speed range when moving forward and the position value indicating the speed range when moving backward are set during the first speed limit state. Resetting the speed range to a speed range that is less than or equal to each position value in the set starting speed range,
The work vehicle according to claim 2 or 3. Equipped with an operating device,
The controller sets one of the plurality of speed ranges as the starting speed range based on a command signal from the operating device.
The work vehicle according to any one of claims 1 to 4. The controller includes:
When the starting speed range is set, storing an index value indicating the set starting speed range;
When the speed limit state changes, setting the start speed range to the speed range indicated by the stored index value;
A work vehicle according to any one of claims 1 to 5.

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