JP2021193899A - Work vehicle - Google Patents

Abstract

To provide a work vehicle capable of elevating a work machine to an appropriate position.SOLUTION: A control device (40) has a positioning control mode to control an elevated position of a work machine (W) on the basis of positioning information obtained through a work machine positioning device (31) and a cover control mode to control the elevated position of the work machine (W) on the basis of a detection result of a rear cover sensor (28). The control device also stores the positioning information, in a storage section, obtained through the work machine positioning device (31) when operated in the cover control mode and sets an average value of height positions on the basis of the positioning information as a reference value to control a height in the positioning control mode.SELECTED DRAWING: Figure 1

Description

The present invention relates to a work vehicle.

Conventionally, in a work vehicle (for example, an agricultural tractor), a leveling plate to be towed is attached so as to be able to move up and down, and a three-dimensional positioning device that moves up and down together with the leveling plate measures the height position in a section such as a field to measure the reference height. A technique is known in which a flat plate is held at a reference height while being calculated and stored, and the soil in a high place is transported to a low place to level the entire section (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-262773

However, in the past, in order to execute control on the premise of mounting a leveling work machine, it was necessary to mount a work machine dedicated to leveling work. For example, when cultivating before the leveling work, it was necessary to perform the cultivating work with the cultivator and then install the leveling work machine. Further, if the leveling work is performed with a cultivator, there is a possibility that the leveling cannot be performed with high accuracy.

The present invention has been made in view of the above, and an object of the present invention is to provide a work vehicle capable of performing leveling with high accuracy.

In order to solve the above-mentioned problems and achieve the object, the work vehicle (1) according to one embodiment is a traveling vehicle body (2) and a working machine (2) vertically attached to the traveling vehicle body (2). W), a vehicle positioning device (30) that measures the position of the traveling vehicle body (2), a working machine positioning device (31) that measures the elevating position of the working machine (W), and the working machine (W). A rear cover (40b) that covers the rear portion, a rear cover sensor (28) that detects the position of the rear cover (40b), and a control device (40) that controls the elevating position of the working machine (W) are provided. The control device (40) has a positioning control mode for controlling the ascending / descending position of the working machine (W) based on the positioning information obtained by the working machine positioning device (31), and the detection result of the rear cover sensor (28). Based on this, it has a cover control mode for controlling the ascending / descending position of the working machine (W), and stores the positioning information of the working machine positioning device (31) when working in the cover control mode in the storage unit. It is characterized in that the average value of height positions based on positioning information is used as a reference value for height control in the positioning control mode.

According to one aspect of the embodiment, leveling can be performed with high accuracy.

FIG. 1 is an explanatory view of a work vehicle according to an embodiment, and is a schematic left side view of the work vehicle. FIG. 2 is a block diagram showing an example of a control system of a work vehicle. FIG. 3 is a flowchart showing a processing procedure of the control processing of the control device according to the embodiment. FIG. 4 is a flowchart showing a processing procedure of the control processing of the control device according to the embodiment. FIG. 5 is a flowchart showing a processing procedure of the control processing of the control device according to the embodiment.

Hereinafter, embodiments of the work vehicle disclosed in the present application will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments shown below.

First, the overall configuration of the work vehicle 1 according to the embodiment will be described with reference to FIG. FIG. 1 is an explanatory view of the work vehicle 1 according to the embodiment, and is a schematic left side view of the work vehicle 1. In the following, a tractor will be described as an example of the work vehicle 1.

The tractor 1 which is a work vehicle is an agricultural tractor that works in a field or the like while self-propelled. Further, the tractor 1 is based on a control system centered on a control device 40 (see FIG. 2), which will be described later, in addition to performing predetermined work while the operator (also referred to as an operator) is on board and traveling in the field. By controlling each part, the predetermined work is executed while automatically traveling in the field.

Further, in the following, the front-rear direction is the traveling direction when the tractor 1 travels straight, and the front side of the traveling direction is defined as "front" and the rear side is defined as "rear". The traveling direction of the tractor 1 is a direction toward the steering wheel 9 from the driver's seat 8, which will be described later, when the tractor 1 travels straight.

The left-right direction is a direction that is horizontally orthogonal to the front-back direction. In the following, left and right are specified toward the "front" side. That is, with the operator of the tractor 1 seated in the driver's seat 8 and facing forward, the left hand side is "left" and the right hand side is "right".

The vertical direction is a direction parallel to the vertical direction. The front-back direction, the left-right direction, and the up-down direction are orthogonal to each other. It should be noted that each direction is defined for convenience of explanation, and the present invention is not limited to these directions. Further, in the following, the tractor 1 may be referred to as an "aircraft".

As shown in FIG. 1, the tractor 1 includes a traveling vehicle body 2 and a working machine W. The traveling vehicle body 2 includes a vehicle body frame 3, front wheels 4, rear wheels 5, a bonnet 6, an engine E, a control unit 7, and a mission case 10. The vehicle body frame 3 is the main frame of the traveling vehicle body 2.

The front wheels 4 are a pair of left and right wheels, and are mainly steering wheels (steering wheels). The rear wheels 5 are a pair of left and right wheels, and are mainly driving wheels (driving wheels). The tractor 1 may be configured to be switchable between a two-wheel drive (2WD) driven by the rear wheels 5 and a four-wheel drive (4WD) driven by both the front wheels 4 and the rear wheels 5. In this case, the drive wheels are both the front wheels 4 and the rear wheels 5. The traveling vehicle body 2 may be provided with a crawler device instead of the wheels (front wheels 4 and rear wheels 5). In this case, the traveling crawler is the drive wheel.

The bonnet 6 is provided so as to be openable and closable at the front portion of the traveling vehicle body 2. The bonnet 6 can be rotated (opened and closed) in the vertical direction with the rear portion as the center of rotation. The bonnet 6 covers the engine E mounted on the vehicle body frame 3 in a closed state. The engine E is a drive source for the tractor 1 and is a heat engine such as a diesel engine or a gasoline engine.

The control unit 7 is provided on the upper portion of the traveling vehicle body 2, and includes a driver's seat 8 and a steering wheel 9. The control unit 7 may be formed by being covered with a cabin 7a provided on the upper portion of the traveling vehicle body 2. The driver's seat 8 is a driver's seat. The steering wheel 9 is operated by the operator when steering the front wheel 4, which is a steering wheel. The steering unit 7 is provided with a display unit (meter panel) for displaying various information in front of the steering wheel 9.

Further, the control unit 7 includes various operation levers such as a forward / backward advance lever, an accelerator lever, a main shift lever, and an auxiliary shift lever, and various operation pedals such as an accelerator pedal, a brake pedal, and a clutch pedal.

The transmission case 10 houses a transmission (transmission mechanism). The transmission appropriately decelerates the power (rotational power) transmitted from the engine E and transmits it to the rear wheels 5 which are the driving wheels and the PTO (Power Take-off) shaft 50.

A working machine W that performs work in the field is connected to the rear portion of the traveling vehicle body 2, and a PTO shaft 50 that transmits power for driving the working machine W projects rearward from the mission case 10. The PTO shaft 50 transmits the rotational power appropriately decelerated by the transmission to the working machine W mounted at least at the rear of the traveling vehicle body 2.

Further, an elevating device 12 for elevating and lowering the working machine W is provided at the rear of the traveling vehicle body 2. The elevating device 12 moves the working machine W to a non-working position by raising the working machine W. The non-working position is, for example, a position where the working machine W is raised when the traveling vehicle body 2 retracts, when the traveling vehicle body 2 turns, or when the tractor 1 travels on the road. Further, the elevating device 12 moves the working machine W to the ground work position by lowering the working machine W. The elevating device 12 includes a hydraulic elevating cylinder 121, a lift arm 122, a lift rod 123, a lower link 124, and a top link 125.

When the hydraulic oil is supplied to the elevating cylinder 121, the lift arm 122 rotates so as to raise the working machine W around the shaft AX which is a rotation fulcrum, and when the hydraulic oil is discharged from the elevating cylinder 121, the lift arm 122 rotates. The work machine W is rotated around the shaft AX so as to be lowered. A lift arm sensor 26 for detecting the rotation angle of the lift arm 122 is provided at the base of the lift arm 122 (near the axis AX). The height of the working machine W is calculated based on the detection result of the lift arm sensor 26 and the positioning information of the positioning devices 30 and 31.

Further, the lift arm 122 is connected to the lower link 124 via the lift rod 123. The lift rod 123 includes a double-acting horizontal control hydraulic cylinder, and the expansion and contraction of the horizontal control hydraulic cylinder causes one of the left and right sides of the working machine W to be raised and lowered. Further, the top link 125 is connected to the working machine W via the top link bracket 125a. In this way, the elevating device 12 connects the working machine W to the traveling vehicle body 2 so as to be able to move up and down by the lower link 124 and the top link 125. Further, a lower link sensor 27 is provided on the rotation shaft which is the base end of the lower link 124 (the side opposite to the connecting portion of the lift rod 123), and the height of the working machine W is the height of the lower link sensor 27. It may be calculated based on the detection result. The lower link sensor 27 may be omitted.

In this embodiment, a case where the working machine W is a rotary tiller is shown as an example. The rotary tiller as the working machine W includes a tiller claw 61, a rotary cover 40a, and a rear cover 40b. The tillage claw 61 is powered by the PTO shaft 50 and rotates to cultivate the soil. The rotary cover 40a covers the upper part of the tilling claw 61. The rear cover 40b is provided on the rear portion of the rotary cover 40a so as to be rotatable in the vertical direction. Further, a rear cover sensor 28 is provided at the base end (rotary cover 40a side) of the rear cover 40b.

The control device 40 described later changes the height of the working machine W by rotating the lift arm 122 based on the detection value of the rear cover sensor 28 or the positioning information of the positioning device 31 described later.

Further, the tractor 1 includes a control device 40 (see FIG. 2). The control device 40 controls the engine E and also controls the traveling speed of the traveling vehicle body 2. Further, the control device 40 controls the working machine W.

Further, the tractor 1 includes two positioning devices 30 and 31. The positioning device 30 is, for example, a GNSS (Global Navigation Satellite System), and can receive radio waves from a navigation satellite S orbiting in the sky to perform positioning and timing.

The positioning device 30 is provided on the upper portion of the traveling vehicle body 2 (cabin 7a) and measures a three-dimensional position including a vertical position (height position) of the traveling vehicle body 2.

The positioning device 31 is provided on the working machine W via the top link bracket 125a, and measures a three-dimensional position including a vertical position (height position) of the working machine W. As described above, the positioning device 31 can be easily attached to and detached from the positioning device 31 by being provided on the top link 125a. Further, the positioning device 31 is provided directly above the center of the rotation axis of the tillage claw 61 (a position aligned linearly with the rotation axis in the vertical direction). This makes it possible to measure the tillage position with high accuracy. It is preferable that the positioning device 31 is provided at both ends of the working machine W in the left-right direction. This enables control in consideration of the height difference caused by the rolling (tilt in the left-right direction) of the tractor 1.

In the following, the positioning device 30 will be referred to as a vehicle positioning device 30, and the positioning device 31 will be referred to as a working machine positioning device 31.

Further, the tractor 1 can set various operations in a specific field by the operation of the information processing terminal (portable terminal such as a tablet terminal) 100 by the operator. The information processing terminal 100 includes, for example, a storage unit composed of a hard disk, a ROM (Read Only Memory), a RAM (Random Access Memory), and a display unit and an operation unit composed of a touch panel. In addition, various keys, buttons, and the like may be separately provided as the operation unit.

Further, the tractor 1 includes an obstacle sensor 20. The obstacle sensor 20 includes a front sensor 21 and a rear sensor 22. The front sensor 21 is arranged at the front portion of the traveling vehicle body 2, for example, attached to a sensor mounting stay 13 provided in front of the bonnet 6, and is an obstacle (person or object) existing in front of the traveling vehicle body 2. Is detected.

The rear sensor 22 is arranged on the upper rear side of the traveling vehicle body 2, for example, attached to the upper portion of the cabin 7a, and detects an obstacle existing behind the traveling vehicle body 2.

Further, both the front sensor 21 and the rear sensor 22 are medium-range sensors, preferably infrared sensors. The front sensor 21 and the rear sensor 22 emit an infrared beam and detect the reflected light from an obstacle. The front sensor 21 has a detection area extending forward. Further, the rear sensor 22 has a detection region extending rearward.

The front sensor 21 and the rear sensor 22 can detect the distance to the obstacle, for example, by measuring the time from emitting the infrared beam to detecting the reflected light from the obstacle. The front sensor 21 and the rear sensor 22, which are infrared sensors, detect obstacles two-dimensionally, and are, for example, a detection area of about several meters to several tens of meters. As the obstacle sensor 20, it is also possible to use a medium-range sensor other than the infrared sensor.

Further, in the present embodiment, the tractor 1 has two traveling modes. Specifically, the tractor 1 manually switches between a field mode for traveling in a field (working travel mode) and a road mode for traveling on a road (non-working travel mode) by a predetermined switch (travel mode selection switch) or the like. It is configured to be possible. The field mode is a control mode selected when working in the field, and is controlled so that the vehicle travels only at a low speed (1 to 10 km / h), for example. The road mode is, for example, a control mode selected when traveling on the road to a field, and is controlled so that the vehicle can travel at a high speed (15 km / h or more), for example.

Further, the tractor 1 according to the embodiment has two control modes regarding the elevating control of the working machine W performed by the control device 40. Specifically, the control device 40 has a positioning control mode for controlling the ascending / descending position of the working machine W based on the positioning information obtained by the working machine positioning device 31, and the working machine W based on the detection result of the rear cover sensor 28. It has a cover control mode that controls the elevating position.

The positioning control mode is a control mode selected when the work of leveling the height of the field is performed by transporting soil while cultivating by the working machine W, and is the positioning information (height) of the working machine positioning device 31. This is a control mode for maintaining the height position of the working machine W at a predetermined reference value based on the information). In the positioning control mode, the soil at the position where the height of the field is higher than the reference value is carried to the position where the height of the field is lower than the reference value, so that the soil can be leveled at the height of the field according to the reference value.

The cover control mode is a control mode selected when cultivating a field by the working machine W, and the cultivating depth is a predetermined reference based on the height position of the rear cover 40b detected by the rear cover sensor 28. The height position of the work machine W is raised and lowered so that the value becomes constant. With the cover control mode, even if the height of the field varies, the cultivation depth can be cultivated at a constant depth according to the reference value.

Then, the control device 40 according to the embodiment switches between these two control modes according to the switching operation of the operator (driver). For example, the control device 40 switches the control mode by a switching operation using a physical switch (pedal type, button type, lever type, etc.) for switching the control mode. Further, the control device 40 may switch the control mode by receiving the switching instruction signal transmitted by the user operation to the information processing terminal 100.

As a result, the user can switch between the elevating control by the working machine positioning device 31 and the elevating control by the rear cover 40b at an arbitrary timing.

Further, the control device 40 according to the embodiment stores the positioning information of the working machine positioning device 31 when working in the rear cover control mode in a storage unit (not shown), and the height position based on the stored positioning information (height information). The average value of is used as a reference value for height control of the working machine W in the positioning control mode.

That is, in order to keep the tillage depth constant in the rear cover control mode, the control device 40 raises and lowers the work machine W according to the height of the field, so that the work machine W is measured by the work machine positioning device 31. As a result, the height of the entire field can be measured. That is, by using the average value of the measured heights of the entire field as the reference value of the height position of the working machine W in the positioning control mode, the field can be leveled with high accuracy.

Next, the control system of the work vehicle (tractor) 1 centering on the control device 40 will be described with reference to FIG. FIG. 2 is a block diagram showing an example of a control system of the work vehicle 1. As shown in FIG. 2, the control device 40 includes an engine ECU (Electronic Control Unit) 41, a traveling system ECU 42, and a working machine elevating system ECU 43. The engine ECU 41 controls the rotation speed of the engine E. The traveling system ECU 42 controls the traveling speed of the traveling vehicle body 2 (see FIG. 1) by controlling the rotation of the drive wheels. The work equipment elevating system ECU 43 controls the elevating device 12 to elevate and control the work equipment W.

The control device 40 can control each part by electronic control, and includes a processing unit having a CPU (Central Processing Unit) and the like, various programs, a planned travel route of the traveling vehicle body 2 preset for each field, and the like. It is equipped with a storage unit that stores the necessary data.

As shown in FIG. 2, the control device 40 includes positioning devices (GNSS) 30, 31, engine rotation sensor 23, vehicle speed sensor 24, turning angle sensor 25, obstacle sensor 20 (front sensor 21 and rear sensor 22). Various sensors such as a lift arm sensor 26, a lower link sensor 27, and a rear cover sensor 28, a tillage depth adjustment dial 300, and the like are connected. The engine rotation sensor 23 detects the rotation speed of the engine E. The vehicle speed sensor 24 detects the traveling speed (vehicle speed) of the traveling vehicle body 2 (see FIG. 1). The turning angle sensor 25 detects the turning angle of the front wheel 4 (see FIG. 1), which is a steering wheel. The tillage depth adjustment dial 300 is a dial-type operation unit for adjusting the tillage depth (plowing depth).

The control device 40 includes position information of the traveling vehicle body 2 from the positioning device 30 in a field or the like, the rotation speed of the engine E from the engine rotation sensor 23, the traveling speed of the traveling vehicle body 2 from the vehicle speed sensor 24, and the front wheel 4 from the turning angle sensor 25. The turning angle, the obstacle detection result from the obstacle sensor 20, the height of the working machine W are input from the lift arm sensor 26, the lower link sensor 27, and the rear cover sensor 28. When the tractor 1 is autonomously driven, the control device 40 controls the steering cylinder connected to the steering wheel 9 while feeding back the steering angle of the front wheels 4 by using the detection result of the steering angle sensor 25. 9 is automatically steered.

Further, in the control device 40, the engine ECU 41 is connected to the engine E, the traveling system ECU 42 is connected to the steering device 51, the transmission device 52, the braking device 53, and the like, and the work equipment elevating system ECU 43 is connected to the elevating device 12. Rudder.

Of these, the work equipment elevating system ECU 43 outputs a work equipment elevating signal toward the elevating device 12. The elevating device 12 elevates and drives the work machine W based on the work machine elevating signal output from the work machine elevating system ECU 43.

Further, the control device 40 is wirelessly connected to, for example, an information processing terminal 100 that can be carried by an operator. The control device 40 controls each part of the tractor 1 based on an instruction signal from the information processing terminal 100 operated by the operator. Further, the control device 40 may be configured to hold the machine information database of the tractor 1 so that information such as a model can be exchanged from the information processing terminal 100 or the like.

Further, the control device 40 stops the traveling vehicle body 2 when an obstacle is detected by the front sensor 21 or the rear sensor 22. Further, when an obstacle is detected by the front sensor 21 or the rear sensor 22, the control device 40 stops the engine E or stops the transmission of the rotational power to the PTO axis. Further, the control device 40 activates an alarm device (not shown) when an obstacle is detected by the front sensor 21 or the rear sensor 22, and the control device 40 detects the obstacle. It may be notified.

Further, the control device 40 has an "automatic operation mode" in which the tractor 1 performs work while autonomously traveling. In the automatic operation mode, the control device 40 determines a planned travel route according to the work content of the work machine W in advance for each field, converts it into data and stores it in the storage unit, and based on the measurement result of the positioning device 30. , Each part such as the engine E, the steering device 51, the speed change device 52, the braking device 53, and the elevating device 12 is controlled so as to travel along the stored scheduled travel path. The planned travel route is set according to the shape and size of the field, the width, length and number of ridges formed in the field, and the type of crop.

Further, as described above, the control device 40 has a field mode (working travel mode) and a road mode (non-working travel mode). For example, when the field mode is selected, the control device 40 automatically raises and lowers the work machine W to a height for performing field work. The height for performing field work can be set differently depending on the type of the working machine W.

Further, as described above, the control device 40 switches between the positioning control mode and the cover control mode according to the switching operation of the operator. Specifically, the control device 40 switches the control mode by a switching operation using a physical switch (pedal type, button type, lever type, etc.) for switching the control mode. Further, the control device 40 may switch the control mode by receiving the switching instruction signal transmitted by the user operation to the information processing terminal 100.

For example, when the power of the tractor 1 is turned on, the control device 40 is first set to the cover control mode, and after the power is turned on, when the driving mode selection switch is first switched to the working driving mode, the operator (driver). ) Is given a predetermined notification.

For example, the control device 40 notifies the display unit provided on the control unit 7 that the cover control mode is set. The control device 40 may notify the voice indicating that the cover control mode is set by, for example, a speaker or the like. Alternatively, the control device 40 may light a specific position of the display unit, or may emit a single beep sound or the like by a speaker or the like.

In this way, by setting the cover control mode as the default when the power is turned on and giving a predetermined notification, the operator does not need to remember the elevating control mode at the time of the previous work, and positioning is performed from the cover control mode. It is possible to avoid forgetting to switch the mode to the control mode. Since the leveling work performed in the positioning control mode is not performed frequently, it is preferable to set the cover control mode as the default. This makes it possible to reduce the number of mode switchings of the operator.

Further, the control device 40 lowers the work machine W according to the decrease amount when the rotation speed of the engine E decreases during work in the cover control mode, and decreases the work machine W according to the increase amount when the rotation speed of the engine E increases. And raise the working machine W.

As a result, in places where the amount of soil is large and the engine is loaded and the number of revolutions decreases, the work machine W is lowered to carry the soil while dragging it, and the amount of soil is small and the engine is not loaded. Where the rotation speed increases, the soil can be released by raising the working machine W, so that the unevenness of the soil in the field during the tilling work can be reduced.

The control device 40 controls the truss mission to automatically reduce the vehicle speed when the amount of decrease in the engine speed decreases by a predetermined threshold value or more during the work in the cover control mode. This avoids an engine stall due to an engine drop that is too large.

Further, the control device 40 stores the positioning information of the working machine positioning device 31 in a storage unit (not shown) while working in the cover control mode. As the positioning information to be stored, all the positioning information received at regular intervals while traveling in the entire field may be stored, or the positioning information at predetermined intervals may be extracted and stored. The stored positioning information is retained for a certain period of time, and is reset when the certain period of time has elapsed. As a result, if the number of elapsed days is small, the past positioning information can be used at the time of the current work, so that the work efficiency can be improved and the old positioning information can be avoided from being used.

Then, when the elevating control mode is switched from the cover control mode to the positioning control mode, the control device 40 sets the average value of the height positions based on the positioning information stored in the storage unit as the reference value for the height control in the positioning control mode. And. That is, the tractor 1 maintains the average value of the height positions based on the positioning information stored in the storage unit as the height position of the work machine W to perform the leveling work.

Further, the control device 40 is based on the work equipment positioning device 31 when the rear cover 40b first detects ground contact (when the amount of change of the rear cover sensor 28 becomes less than a predetermined value) when the positioning control mode is switched. The height is set as a reference value of the shallowest position on the tillage depth adjustment dial 300 in the positioning control mode.

In this way, by setting the reference value of the shallowest position in the tillage depth adjustment dial 300 in the positioning control mode based on the position of the rear cover 40b, the tillage depth adjustment by the tillage depth adjustment dial 300 can be performed with high accuracy. ..

Further, the control device 40 uses the average value of the height position based on the positioning information of the working machine positioning device 31 stored in the storage unit as the reference value of the center position in the tillage depth adjustment dial 300 in the positioning control mode.

In this way, by setting the reference value of the center position in the tillage depth adjustment dial 300 in the positioning control mode based on the positioning information in the cover control mode, the tillage depth adjustment by the tillage depth adjustment dial 300 can be performed with high accuracy. Can be done.

Further, in the positioning control mode, when the rear cover sensor 28 detects the rise of the rear cover 40b, the control device 40 lowers the working machine W according to the amount of rising, and when the rear cover sensor 28 detects the lowering of the rear cover 40b, the control device 40 lowers the working machine W. Raise it.

As a result, when the amount of soil is large and the rear cover 40b rises, the working machine W is lowered to carry the soil while dragging it, and when the amount of soil is small and the rear cover 40b is lowered, the working machine W is raised. As a result, the soil can be opened, so that the unevenness of the soil in the field can be reduced and the soil can be leveled with high accuracy.

Further, the control device 40 generates height map information regarding the height of the ground in the field based on the positioning information stored in the storage unit, and the height of the working machine W in the positioning control mode is based on the height map information. Control may be performed. The height map information is information in which the position (absolute position or relative position) in the field and the height information in the positioning information are linked.

For example, in the positioning control mode, the control device 40 lowers the working machine W according to the height of the ground at a point where the height of the ground is equal to or higher than a predetermined value based on the height map information, and the height of the ground is lowered. At a point below a predetermined value, the working machine W is raised according to the height of the ground.

As a result, in places where the ground height is high, that is, where the amount of soil is large, the work machine W is lowered to carry the soil while dragging it, and in places where the ground height is low, that is, where the amount of soil is small, the work machine W is lowered. Since the soil can be released by raising the working machine W, it is possible to reduce the unevenness of the soil in the field and level it with high accuracy.

Although the control device 40 shows the case where the elevating control mode is switched by manual switching by the switching operation of the operator, the elevating control mode may be automatically switched. For example, the control device 40 automatically sets the cover control mode when the rear cover 40 is attached. Further, the control device 40 automatically sets the positioning control mode when the positioning information is input from the working machine positioning device 31. When the rear cover 40 is attached to the control device 40 and the positioning information is input from the working machine positioning device 31, the frequently used cover control mode may be preferentially set. In this way, by setting the switching priority of the elevating control mode, it is possible to avoid confusion of the operator. Further, the control device 40 is not limited to the case where the cover control mode is preferentially set, and may notify the operator and accept the selection operation of the elevating control mode.

Next, the processing procedure of the control process of the control device 40 according to the embodiment will be described with reference to FIGS. 3 to 5. 3 to 5 are flowcharts showing a processing procedure of control processing of the control device 40 according to the embodiment.

Note that FIG. 3 describes the elevating control mode switching process by the control device 40, FIG. 4 describes the setting process of the tillage depth adjustment dial, and FIG. 5 describes the elevating control process of the working machine W.

First, the elevating control mode switching process by the control device 40 will be described with reference to FIG.

First, the control device 40 starts turning on the power according to the operation of the operator (step S101).

Subsequently, the control device 40 sets the elevating control mode to the cover control mode after the power is turned on (step S102).

Subsequently, the control device 40 determines whether or not the traveling mode is the working traveling mode (step S103).

When the traveling mode is the working traveling mode (step S103: Yes), the control device 40 displays the cover control mode on the display unit of the control unit 7 (step S104).

Subsequently, the control device 40 determines whether or not the operator has switched the elevating control mode after displaying the cover control mode (step S105).

When there is no switching operation of the elevating control mode (step S105: Yes), the control device 40 starts the work in the cover control mode (step S106) and ends the process.

On the other hand, in step S105, when the elevating control mode is switched (step S105: No), the control device 40 switches from the cover control mode to the positioning control mode and starts the work in the positioning control mode (step S107). , End the process.

Further, in step S103, when the traveling mode is the non-working traveling mode (step S103: No), the control device 40 starts traveling with the working machine W maintained in the non-working position (step S108), and processes. To finish.

Subsequently, the setting process of the tillage depth adjustment dial will be described with reference to FIG.

First, it is assumed that the control device 40 is working in the cover control mode (step S201).

Subsequently, the control device 40 stores the information on the height position of the work machine W, which is the positioning information of the work machine positioning device 31, in the cover control mode (step S202).

Subsequently, the control device 40 calculates the average value of the height positions based on the plurality of stored positioning information (step S203).

Subsequently, the control device 40 sets the reference value of the tillage depth adjustment dial (step S204), and ends the process. Specifically, the control device 40 sets the calculated average value as the median value in the tillage depth adjustment dial.

Subsequently, the elevating control process of the working machine W will be described with reference to FIG.

First, it is assumed that the control device 40 is working in the positioning control mode (step S301).

Subsequently, the control device 40 determines whether or not the rear cover 40b has risen by a predetermined value or more in the positioning control mode (step S302).

When the rear cover 40b rises by a predetermined value or more (step S302: Yes), the control device 40 lowers the working machine W by an amount corresponding to the rising amount of the rear cover 40b (step S303), and ends the process.

On the other hand, in step S302, when the rear cover 40b does not rise by a predetermined value or more (step S302: No), the control device 40 determines whether or not the rear cover 40b has lowered by a predetermined value or more (step S304).

When the rear cover 40b is lowered by a predetermined value or more (step S304: Yes), the control device 40 raises the working machine W by an amount corresponding to the amount of lowering of the rear cover 40b (step S305), and ends the process.

On the other hand, in step S304, when the rear cover 40b does not lower by a predetermined value or more (step S304: No), the control device 40 maintains the height position of the working machine W (step S306), and ends the process.

As described above, the tractor 1 according to the embodiment includes the traveling vehicle body 2, the working machine W attached to the traveling vehicle body 2 so as to be able to move up and down, the vehicle positioning device 30 for measuring the position of the traveling vehicle body 2, and the working machine W. A work equipment positioning device 31 that measures the elevating position, a rear cover 40b that covers the rear part of the work equipment W, a rear cover sensor 28 that detects the position of the rear cover 40b, and a control device 40 that controls the elevating position of the work equipment W. The control device 40 has a positioning control mode for controlling the elevating position of the working machine W based on the positioning information obtained by the working machine positioning device 31, and the elevating position of the working machine W based on the detection result of the rear cover sensor 28. The cover control mode to be controlled is switched according to the switching operation of the driver. As a result, it is possible to switch between the elevating control by the working machine positioning device 31 and the elevating control by the rear cover 40b.

Further, the tractor 1 has a plowing depth adjusting dial for adjusting the plowing depth. When the control device 40 switches to the positioning control mode, the height based on the work equipment positioning device 31 when the rear cover 40b first detects touchdown is used as a reference for the shallowest position in the tillage depth adjustment dial of the positioning control mode. Use as a value. Thereby, by setting the reference value of the shallowest position in the tillage depth adjustment dial 300 in the positioning control mode based on the position of the rear cover 40b, the tillage depth adjustment by the tillage depth adjustment dial 300 can be performed with high accuracy.

Further, the tractor 1 has a traveling mode selection switch for switching the traveling mode of the traveling vehicle body 2 into a working traveling mode and a non-working traveling mode. The control device 40 sets the cover control mode when the power is turned on, and gives a predetermined notification to the driver when the running mode selection switch is first switched to the working running mode after the power is turned on. As a result, the cover control mode is set as the default when the power is turned on, and by giving a predetermined notification, the operator does not need to remember the elevating control mode at the time of the previous work, and the positioning control is performed from the cover control mode. It is possible to avoid forgetting to switch the mode to the mode.

Further, the tractor 1 performs an engine rotation sensor 23 for detecting the rotation speed of the engine E. When the rotation speed of the engine E decreases during work in the cover control mode, the control device 40 lowers the work machine W according to the decrease amount, and when the rotation speed of the engine E increases, the control device 40 works according to the increase amount. Raise the machine W. As a result, in places where the amount of soil is large and the engine is loaded and the number of revolutions decreases, the work machine W is lowered to carry the soil while dragging it, and the amount of soil is small and the engine is not loaded. Where the rotation speed increases, the soil can be released by raising the working machine W, so that the unevenness of the soil in the field during the tilling work can be reduced.

Further, the tractor 1 has a transmission. The control device 40 controls the transmission to reduce the vehicle speed when the amount of decrease in the rotation speed of the engine E becomes equal to or more than a predetermined threshold value during work in the cover control mode. This avoids an engine stall due to an engine drop that is too large.

As described above, the tractor 1 according to the embodiment includes the traveling vehicle body 2, the working machine W attached to the traveling vehicle body 2 so as to be able to move up and down, the vehicle positioning device 30 for measuring the position of the traveling vehicle body 2, and the working machine W. A work equipment positioning device 31 that measures the elevating position, a rear cover 40b that covers the rear part of the work equipment W, a rear cover sensor 28 that detects the position of the rear cover 40b, and a control device 40 that controls the elevating position of the work equipment W. The control device 40 has a positioning control mode for controlling the elevating position of the working machine W based on the positioning information obtained by the working machine positioning device 31, and the elevating position of the working machine W based on the detection result of the rear cover sensor 28. It has a cover control mode to control. Further, the control device 40 stores the positioning information of the working machine positioning device 31 when working in the cover control mode in the storage unit, and controls the average value of the height positions based on the positioning information in the positioning control mode. Use as the reference value for. As a result, the field can be leveled with high accuracy.

Further, the tractor 1 has a plowing depth adjusting dial for adjusting the plowing depth. The control device 40 uses the average value of the height positions based on the positioning information of the work equipment positioning device 31 as the reference value of the center position on the tillage depth adjustment dial in the positioning control mode. As a result, by setting the reference value of the center position in the tillage depth adjustment dial 300 in the positioning control mode based on the positioning information in the cover control mode, the tillage depth adjustment by the tillage depth adjustment dial 300 can be performed with high accuracy. can.

Further, in the positioning control mode, when the rear cover sensor 28 detects the rise of the rear cover 40b, the control device 40 lowers the working machine W according to the amount of rising, and when the rear cover sensor 28 detects the lowering of the rear cover 40b, the control device 40 lowers the working machine W. Raise it. As a result, when the amount of soil is large and the rear cover 40b rises, the working machine W is lowered to carry the soil while dragging it, and when the amount of soil is small and the rear cover 40b is lowered, the working machine W is raised. As a result, the soil can be opened, so that the unevenness of the soil in the field can be reduced and the soil can be leveled with high accuracy.

Further, the control device 40 generates height map information regarding the height of the ground in the field based on the positioning information of the working machine positioning device 31. Further, in the positioning control mode, the control device 40 lowers the working machine W according to the height of the ground at a point where the height of the ground is equal to or higher than a predetermined value based on the height map information, and the height of the ground is lowered. At a point below a predetermined value, the working machine W is raised according to the height of the ground. As a result, when the ground height is high, that is, where the amount of soil is large, the work machine W is lowered to carry the soil while dragging it, and when the ground height is low, that is, where the amount of soil is small, the work machine W is lowered to carry the soil. Since the soil can be released by raising the working machine W, it is possible to reduce the unevenness of the soil in the field and level it with high accuracy.

Further effects and variations can be easily derived by those skilled in the art. For this reason, the broader aspects of the invention are not limited to the particular details and representative embodiments described and described above. Thus, various modifications can be made without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents.

1 Tractor (working vehicle)
2 Traveling vehicle body 28 Rear cover sensor 30 Vehicle positioning device 31 Working machine positioning device 40 Control device 40a Rotary cover 40b Rear cover W Working machine

Claims (4)

With the running body
A work machine attached to the traveling vehicle body so as to be able to move up and down,
A vehicle positioning device that measures the position of the traveling vehicle body, and
A work equipment positioning device that measures the position of the work equipment, and
A rear cover that covers the rear of the work machine,
A rear cover sensor that detects the position of the rear cover and
A control device for controlling the ascending / descending position of the working machine is provided.
The control device is
A positioning control mode that controls the elevating position of the working machine based on the positioning information obtained by the working machine positioning device, and a cover control mode that controls the elevating position of the working machine based on the detection result of the rear cover sensor. Have and
The positioning information of the working machine positioning device when working in the cover control mode is stored in the storage unit, and the average value of the height positions based on the positioning information is used as the reference value for height control in the positioning control mode. A work vehicle characterized by that. Has a tillage depth adjustment dial to adjust the tillage depth,
The control device is
The work vehicle according to claim 1, wherein the average value of the height positions based on the positioning information of the work machine positioning device is set as a reference value of the center position in the tillage depth adjustment dial of the positioning control mode. The control device is
In the positioning control mode, when the rear cover sensor detects an increase in the rear cover, the work machine is lowered according to the amount of increase, and when the rear cover sensor detects a decrease in the rear cover, the work machine is raised. The work vehicle according to claim 1 or 2. The control device is
Based on the positioning information of the work equipment positioning device, height map information regarding the height of the ground in the field is generated.
In the positioning control mode, based on the height map information, at a point where the height of the ground is equal to or higher than a predetermined value, the work machine is lowered according to the height of the ground, and the height of the ground is a predetermined value. The work vehicle according to any one of claims 1 to 3, wherein the work machine is raised according to the height of the ground at a point less than or equal to.

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