JPH0321567A - Work vehicle swing control device - Google Patents

Abstract

PURPOSE:To enhance the cornering characteristic by furnishing an attitude changeover means, which makes changeover into a condition where only a part of the grounding part of that of a left and a right crawler running device which is situated nearer the center of cornering is grounded on the basis of a changeover command of the cornering condition for a steering means to control the drive of the crawler running devices. CONSTITUTION:A cornering control device according to the present invention is equipped with a rolling drive means 15, which tilts the machine body of a working vehicle such as a combine to the left and right with respect to the grounding part of a left and a right crawler running device, and a pitching drive means 16 which tilts the same fore and aft. They are controlled by a control means 100. In the rolling control, the rolling drive means 15 is controlled in the direction of lessening the difference of the target tilt angle determined by a left/right tilt angle setting device 19 from the value of sensing with a left/right tilt angle sensor S2, and changeover is made into a condition where only a part of the grounding part of that of the left and right crawler running devices which is situated nearer the center of cornering is grounded. In the pitching control, on the other hand, the abovementioned pitching drive means 16 is controlled according to the difference of the value from sensing by a fore-and-aft tilt angle sensor S3 from the target tilt angle by reference to a fore-and-aft tilt angle setting value 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for controlling the attitude of a work vehicle such as a combine harvester when turning.

[Conventional technology]

As a swing control device for such a working vehicle, for example, Japanese Patent Laid-Open No. 5
As disclosed in Japanese Patent No. 9-84677, a swing control for a combine harvester is configured to shorten the length of a traveling crawler before and after touching the ground in a non-working state of the reaping section by raising and lowering a crawler guiding ground roller. There was a device. This device is designed to reduce mud pressure (mud pressure caused by changing the direction of the crawler on the inside of the turn) when the reaping section is switched to a non-working state and turns around a headland. It was possible to turn smoothly and favorably with a shortened length before and after touchdown, that is, with reduced turning resistance.

[Problem to be solved by the invention]

However, in the conventional turning control device for a work vehicle, the lengths of both the left and right traveling crawlers before and after touching the ground are shortened when turning, so there is a problem in that the main body of the vehicle becomes unstable with respect to longitudinal inclination. Furthermore, since the length of the traveling crawler on the outside of the turn before and after contact with the ground is shortened, the frictional resistance due to contact with the ground is reduced, making it more likely to slip.

The present invention was made in order to improve these difficulties, and its purpose is to enable a working vehicle to turn smoothly and stably with a small amount of mud pressure. [Means for Solving the Problems] In order to achieve the above object, the turning control device for a working vehicle of the present invention has a state in which a pair of left and right crawler traveling devices supporting the body of the machine are driven at the same speed. , a steering means for switching to a turning state in which the steering device is driven at different speeds, or in mutually opposite directions, or in which only one side is driven, and based on a command to the steering means to switch to the turning state,
A first feature of the present invention is that it includes an attitude switching means for switching only a portion of the grounding portion of the left and right crawler traveling devices closer to the center of rotation to a state in which only a portion of the grounding portion of the left and right crawler traveling devices is in contact with the ground.

A second characteristic configuration is that the attitude switching means is configured to tilt the ground contact portions of the left and right crawler traveling devices back and forth with respect to the main body.

Furthermore, the posture switching means changes to a forward-downward posture when moving forward;
The third feature is that the vehicle is designed to switch to a backward position when traveling backwards.

[For production]

According to the first characteristic configuration, when a command to switch to the turning state is issued to the steering means, the work vehicle drives the pair of left and right crawler traveling devices at different speeds, or in opposite directions, or drives the left and right crawler traveling devices on one side. It is in a turning state where only the motor is driven.

Then, based on a command to switch the steering means to the turning state, the attitude switching means switches to a state in which only a part of the ground contact portion of the left and right crawler traveling devices on the side of the turning center is in contact with the ground.

According to the second characteristic configuration, in a turning state, only the one on the turning center side of the left and right crawler traveling devices is tilted forward and backward with respect to the main body of the aircraft. switch to a state where only the ground is substantially grounded.

According to the third feature, when turning in the forward state, the crawler traveling device on the turning center side is tilted;
In other words, the main body of the aircraft is switched to a forward-downward posture relative to the crawler traveling device on the side of the turning center. As a result, the work vehicle turns around the front part of the ground contact area of the crawler traveling device on the side of the turning center. In addition, when turning in the backward state, the crawler traveling device on the side of the turning center is tilted, that is, the aircraft body is switched so that it is in a position lowering backward relative to the crawler traveling device on the side of the turning center. As a result, the work vehicle turns around the rear part of the ground contact area of the crawler traveling device on the side of the turning center.

〔Effect of the invention〕

According to the first characteristic structure, even if the state is switched to the turning state, the ground contact area of the outer crawler traveling device can be widened.
The aircraft will be able to turn while keeping it stable against tilting forward and backward.

Furthermore, since the friction between the crawler traveling device on the outside of the turn that propels the work vehicle and the ground increases, slips are less likely to occur during the turn. Then, it will be possible to turn with a small amount of power.

According to the second feature, it is possible to use a pitching structure that tilts the main body forward and backward, so if the work vehicle has a pitching structure, it is equipped with a special device that raises and lowers a part of the ground contact part of the crawler traveling device. There are advantages to doing without it.

According to the third characteristic structure, since the part of the grounding part of the crawler traveling device on the side of the turning center on the traveling direction side is brought into contact with the ground, the load is concentrated on that part, the movement of the fulcrum is reduced, and it is possible to turn smoothly. Become.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in Fig. 8, the main body (8), which is equipped with a threshing device (1), a control section (2), etc., is supported by a pair of left and right crawler traveling devices (3L) and (3R). A combine harvester, which is an example of a working vehicle, is constructed by attaching a reaping processing section (4) to the front end of the main body (A) so that it can be raised and lowered.

First, the crawler traveling device (3L), (31?)
The attachment structure to the fuselage body (8) will be explained. However, since these have a bilaterally symmetrical structure, the mounting structure on the right side will be omitted.

As shown in FIGS. 6 and 7, frames (6) are attached below the main frame (5) at predetermined intervals along the front and back direction, and left and right fixed sides are attached to both ends of these frames (6), respectively. The track frames (7) are connected and fixed to form the frame portion of the main body (^).

In front of each of these stationary side track frames (7) and behind the movable side track frame (l2) to be described later, there are drive subrockets (9) that apply rotational force to the crawler (8) and tensioners that apply tension. sprocket(
10). A plurality of idle wheels (11) are pivotally supported on the movable track frame (l2). At an intermediate position of the group of idle wheels (l1), there is an idle wheel (l3) that is movable up and down with respect to the truck frame (7).
is supported.

The movable track frame (l2) also includes front and rear bell cranks (14A) and (14B) which are pivotally supported in the front and rear of the fixed track frame (7) so as to be movable up and down.
) are connected to the lower ends of these bell cranks (14^
)． A pitching hydraulic cylinder (CY2L) is constructed and connected across the upper part of (14B). Furthermore, a stroke sensor (SL) is attached to detect the amount of expansion and contraction of the pitching hydraulic cylinder (CY2L). A rolling hydraulic cylinder (CYI) is installed between the upper end of the rear bell crank (14B) and the main frame (5).
L) are constructed and connected.

Left and right rolling hydraulic cylinders (CYIL), (CY
IR) 2 is the electromagnetic hub (Vl), (V2), and the left and right pinoting hydraulic cylinders (CY2L), (CY
2R) is connected to electric valves (ν3〉, (ν4).Then, by operating the lightning valves (Vl) and (V2), the rolling hydraulic cylinder (CYIL),
(CYIR) expands and contracts, solenoid valve (V3),
By operating (V4), the pitching hydraulic cylinder (
CY2L) and (CY2R) are designed to expand and contract.

With this structure, the main body (A) is connected to the crawler traveling device (3L). (3R) A rolling drive means (15) that tilts in the left-right direction with respect to the ground contact area, and a pitching drive (16) that tilts in the front-back direction are configured.

The rolling drive means (15) includes left and right rolling hydraulic cylinders (CYIL). When (CYIR) is extended, the rear bell crank (14B) and front bell crank (14^) are integrally driven to swing clockwise in the figure, and the movable track frame (12) is lowered. The left and right crawler traveling devices (3L), (3R)
), so that the main body (A) of the aircraft rises with respect to the ground contact point of the left and right rolling hydraulic cylinders (CYIL).
, (CYIR) is retracted, the rear bell crank (14B) and front bell crank (14A) are integrally driven to swing counterclockwise in the figure, and the movable track frame (12) rises. As a result, the main body (A) acts to lower the ground contact portions of the left and right crawler traveling devices (3L) and (3R). And furthermore,
Left and right rolling hydraulic cylinders (CYIL), (
CYIR) operates separately and has a movable frame (12A).
, (12B), the aircraft body (A) is moved between the left and right crawler traveling devices (3L), (3R).
) can be tilted to the right with respect to the ground contact area.

Further, in the pitching drive means (I6), when the left and right pitching hydraulic cylinders (CY2L) and (CY2R) are extended, the front bell crank (14A) is driven counterclockwise in the figure, and the movable track frame (12) is driven counterclockwise in the figure. ) rises, which causes the left and right crawler traveling devices (3
L), (3R) to the aircraft body (8)
Conversely, when the left and right pitching pressure cylinders (CY2L) and (CY2R) contract so that the front bell crank (14^) is tilted forward, the front bell crank (14^) is driven clockwise in the figure and the movable track frame is moved. (12) is lowered, thereby lowering the left and right crawler traveling devices (3L).
The main body (A) acts so as to tilt backward with respect to the ground contact area (3R).

In addition, (LSWIL) in Fig. 6 is the upper limit position of the front part of the movable track frame (12) (the front part of the main body (8) is closest to the crawler traveling devices (3L), (3R)). The front lower limit switch (LSW2L) is for detecting the position of the movable track frame (
12) Front upper limit switch (LSW3L) for detecting the lower limit position of the front part (the position where the front part of the main body (^) is farthest from the crawler traveling device (3L). (3R)). ) is the movable track frame (12
) for detecting the rear upper limit position (the position where the rear of the main body (A) is closest to the crawler traveling device (3L). (3R));
LSW4L) is the lower limit position at the rear of the movable trunk frame (l2) (the position where the rear of the aircraft body (8) is the furthest away from the crawler traveling devices (3L) and (3R))
This is the rear upper limit switch for detecting. These are also installed on the right crawler traveling device (3R).
To distinguish it from the left, R is added instead of L after the numbers 1 to 4 to distinguish it.

As shown in Fig. 5, the control section (2) includes an automatic/manual mode changeover switch (SW) for switching between automatic mode and manual mode, and a crawler traveling device (3L), ( 3R), the control lever (l7) used to tilt the aircraft in the left/right force direction or the front/rear direction, and the main body (A
) is provided with a steering lever (18) used to turn the vehicle. In addition, there is a left/right tilt angle setting device (l9) used to set the left and right tilt angle of the aircraft body (A) with respect to the horizontal reference plane during rolling control in automatic mode, and a left/right tilt angle setting device (19) used to set the left and right tilt angle of the aircraft body (A) with respect to the horizontal reference plane during rolling control in automatic mode. A longitudinal inclination angle setter (20) used to set the longitudinal inclination angle with respect to the horizontal reference plane is also provided.

On the other hand, the fuselage main body (A) includes a left-right tilt angle sensor (S2) of the second weight, which detects the tilt of the fuselage main body (A) in the left-right direction with respect to the horizontal reference plane, and a left-right tilt angle sensor (S2) that detects the tilt of the main body (A) with respect to the horizontal reference plane in the longitudinal direction. A weight-type longitudinal inclination angle sensor (S3) is provided, and a direction sensor (S4) is provided to detect forward or backward movement, and a steering actuator (21) for changing the direction of movement of the main body (A). It is equipped with

The above switches, sensors, setting devices, and steering actuators (21) are integrated into one control device (21) that is composed of a microcomputer as its core, as shown in
00). And this control device (100)
has an output boat for driving the solenoid provided in the electromagnetic valves m) to (v4), and when calculations for attitude control are performed based on various information, the appropriate solenoid of the control device (100) is activated. The contents of the output flag are written to the output port to drive the solenoid.

The solenoid output flags include lower left front, upper left front,
Lower left rear, upper left rear, lower right front, upper right front, lower right rear, upper right rear 8
There are different types. Left and right mean the left and right sides of the main body (7), front and rear mean the front and rear of the main body (7), and top and bottom mean the operating direction of the main body (7).

The operating lever (l7) has a structure that allows it to be operated in four directions, front, back, left, and right from a neutrally biased state at the center;
Four operation switches (17a) to (17d) are provided so that the respective operation directions can be detected. These operation switches (17a) to (17d) are designed to operate effectively in manual mode.

The swing lever (I8) has a structure in which it can be operated in two directions, right and left, from a neutrally biased state at the center, and two swing switches (18a) . (18b). These pivot switches (18a). (18b) is designed to operate effectively in both automatic and manual modes. These swivel switches (18a), (18b)
When turned ON, a signal for a turning command is output from the control device (100) to the steering actuator (21).

The steering actuator (21) includes a side clutch brake (not shown) that is interlocked with the left and right drive sprockets (9), and a steering cylinder (not shown) for operating the side clutch brake. It is equipped with This makes it possible to intermittent the driving force transmitted to the drive sprocket (9) or to apply braking force to the drive sprocket (9) whose driving force has been cut off.

Therefore, operate the turning lever (l8) to the left from the neutral position to switch to the left turning lever. When Tsuchi (18a) is turned on, braking is applied to the left crawler traveling device (3L) and only the right crawler traveling device (3R) is driven, causing the main body (A) of the aircraft to turn to the left. Become. When you turn on the right turn switch (18b) by operating it to the right, braking is applied to the right crawler traveling device (3R), only the left crawler traveling device (3L) is driven, and the main body (
8〉 will start turning to the right.

The left and right tilt angle setter (19) and the front and back tilt angle setter (2)
0) is provided with a volume, and a target inclination angle is set based on the output information. These are designed to be effective only in automatic mode.

Next, the roles of the eight types of solenoid output flags mentioned above will be explained. However, since it is bilaterally symmetrical, the explanation of the right solenoid output flag will be omitted.

When the left front lower solenoid output flag is set and written to the output port, the left rolling hydraulic cylinder (C
With the pitching hydraulic cylinder (CY2L) stopped, the left pitching hydraulic cylinder (CY2L) is extended and the left front part of the fuselage body (A) is lowered.

When the left front upper solenoid output flag is set and written to the output port, the left hydraulic cylinder for pitching (CY2L) is contracted while the left rolling hydraulic cylinder (CYIL) is stopped, and the main body of the aircraft is (
The front left side of A) rises.

Also, when the left rear lower solenoid output flag is set and written to the output boat, the left rolling hydraulic cylinder (CYIL) and pitching hydraulic cylinder (CY2L)
) simultaneously contract, and the left rear part of the fuselage body (A) descends. When the left rear upper solenoid output flag is set and written to the output boat, the left rolling hydraulic cylinder (CYIL) and pitching hydraulic cylinder (CY
2L) is extended at the same time, and the rear left side of the fuselage body (^) rises.

In addition, when the left front lower solenoid output flag and the left rear lower solenoid output flag are set at the same time and written to the output port, the left rolling hydraulic cylinder (CY2L) is inactive while the left pitching hydraulic cylinder (CY2L) is CYIL) contracts and the left side of the aircraft body (A) descends. When the left front upper solenoid output flag and the left rear upper solenoid output flag are set at the same time and written to the output boat, the left pitching hydraulic cylinder (CY2L
), the left rolling hydraulic cylinder (CYIL) expands and contracts, and the left side of the fuselage body (A) rises.

Furthermore, when the left and right front and lower solenoid output flags are set at the same time and written to the output boat, the left and right rolling hydraulic cylinders (CYIL) and (CYII?) are inactive, and the left and right pitching hydraulic cylinders (CYIL) and (CYII?) are not activated.
CY2L). (CY2R) is extended and the front part of the fuselage body (A) is lowered. When the left and right front upper solenoid output flags are sent and written to the output boat, the left and right rolling hydraulic cylinders (CYIL), (CY
IR) has stopped operating, the left and right pitching hydraulic cylinders (CY2L). (CY2R) is contracted and the front part of the fuselage body (A) rises.

Note that the explanation of the rear part of the fuselage main body (A) will be omitted.

Next, the control operation of the control device (100) will be explained based on the flowcharts of FIGS. 2 to 5.

First, after starting, the timer and output flags of various solenoids are initialized (step 100). Then, after a predetermined time (approximately 10msEc) has passed (step 2
00), performs output control to write the contents of various output flags (step 300), and clears the output flags (step 400).

Next, output values from various sensors, switches, and setting devices are read (step 500). Then, the output values of the left and right tilt angle setter (19) and the front and rear tilt angle setter (20) are corrected and set as the left and right target tilt angle and the front and rear target tilt angle (step 600).

After completing the settings, check the left turn switch (18a) (step 700), and if it is ON, execute the left turn process (step 800), and if it is OFF, use the right turn switch (18b).
(step 900). and the right turn switch (
If 18b) is ON, a right turn process is executed (step 1000), and if it is OFF, the automatic/manual mode changeover switch (SW) is checked (step 1100).

If the automatic mode is selected by the automatic/manual mode changeover switch (SW), rolling control and pitching control are executed (steps 1200 and 1300).
, if the manual mode is selected, manual operation processing is performed (step 1400). Thereafter, condition flag clearing is executed to clear the output flag when a certain condition is not met (step 1500). These processes are repeatedly executed after initialization.

In the left and right turning process, the control means 000) serves as an attitude switching means for switching only a part of the ground contact area on the turning center side of the left and right crawler traveling devices W (3L), (3R) to a state where only a part of the ground contact area is in contact with the ground. act.

What is shown in FIG. 3 is a subroutine for left turn processing executed by the stethoscope 800.

First, the right crawler traveling device (3L) is stopped and brake is applied. Then, it is checked whether the vehicle is moving forward or backward, and if the vehicle is moving forward, the left front lower limit switch (LSWIL) is checked, and if it is OFF, the left front lower solenoid output flag is set (steps 801 to 804). If it is determined in step 803 that it is ON, check the left rear upper limit switch (LSW4L) (step 805), if it is OFF, set the left rear upper solenoid output flag (step 806), and if it is ON, the buzzer ( BZ) is executed without sounding the alarm process (step 807).

If it is determined in step 802 that the vehicle is moving backward, the left rear lower limit switch (LSW3L) is checked, and if it is OFF, the left rear lower solenoid output flag is set (steps 808, 809). If it is determined to be ON in step 808, check the left front upper limit switch (LSW2L) (step 810), and if it is OFF, set the left front upper solenoid output flag (step 811). (step 807).

What is shown in FIG. 4 is a subroutine for right turn processing executed at step 1000.

First, the right crawler traveling device (3R) is stopped and braked (step 1001).

Then, it is checked whether the vehicle is moving forward or backward, and if the vehicle is moving forward, the right front lower limit switch (LSWIR) is checked, and if it is OFF, the right front lower solenoid output flag is set (steps 1001-1004). If it is determined to be ON in step 1003, the right rear upper limit switch (LSW4
R) (step 1005), and if it is OFF, set the right rear upper solenoid output flag (step 1006).
) If L, ON, execute alarm processing (step 1
007).

If it is determined in step 1002 that the vehicle is moving backward, the right rear lower limit switch (LSW3R) is checked, and if it is OFF, the right rear lower solenoid output flag is set (steps 1008 and 1009). Step 10
If it is determined that 0B is OFF, check the right front upper limit switch (LSW2R) (step 1010),
If it is OFF, the nisolenoid output flag is set (step 1011), and if it is ON, alarm processing is executed (step 1007).

In the rolling control of step 1200, the control device l
(100) calculates the difference (left/right declination angle) between the target inclination angle by the left stone inclination angle setting device (1) and the detected value of the left/right inclination angle sensor (S2), and moves the aircraft body in a direction to reduce this difference. (
A) is the left and right crawler traveling device (31), (3R)
Rolling system is applied by controlling each ground contact point separately.
<Do It. For example, if the main body of the aircraft (A) is tilted to the left from the target inclination angle, set the left front upper solenoid output flag and the left rear upper solenoid output flag at the same time, or set the right front lower solenoid output flag and the right rear lower solenoid output flag. By setting the output flag at the same time, the aircraft body (A)
This automatically corrects the left and right target and target inclination angles.

In the pitching control of step l300, the control device (100) calculates the difference (longitudinal deviation angle) between the target inclination angle by the longitudinal inclination angle setter (20) and the detected value of the longitudinal inclination angle sensor (S3), and The main body of the aircraft (A
) to the ground contact areas of the left and right crawler traveling devices (3L) and (3R) to perform pitching control.

For example, if the main body of the aircraft (A) is tilted ahead of the target tilt angle, set the left front upper solenoid output flag and the right front upper solenoid output flag at the same time, or set the left rear lower solenoid output flag and the right rear lower solenoid output flag at the same time. By setting the output flag at the same time, the main body (A) of the aircraft is automatically corrected to the target longitudinal inclination angle.

In the manual operation of step l400, the control device (10
0) puts all the operation switches (17a) to (17d) into a standby state in which they are not operated when the operation lever (17) is in the neutral position. Also, when the left tilting operation switch (17a) is turned on by being operated to the left from the neutral position, the left front lower solenoid output flag and the left rear lower solenoid output flag are set to the same value, and if the limit has been reached, Set the right front upper solenoid output flag and the right rear upper solenoid output flag at the same time, and tilt the aircraft body (^) to the left. When the right tilt operation switch (17b) is turned on by operating to the right, the right front lower solenoid output flag and the right rear lower solenoid output flag are set simultaneously, and if the limit has been reached, the left front upper solenoid output flag is set. Set the left rear upper solenoid output flag at the same time and tilt the main body (A) to the right. When the forward tilting operation switch (17c) is turned ON by being operated forward, the lower left front solenoid output flag and the lower right front solenoid output flag are set simultaneously, and when the limit has been reached, the upper left rear solenoid output flag is set. and the right rear upper sonic output flag at the same time, and tilt the main body of the aircraft (A) forward. When the rearward tilting operation switch (17d) is operated later and turned ON, the left rear lower solenoid output flag and the right rear lower solenoid output flag are set simultaneously, and if the rearward tilting operation switch (17d) is turned on, the left front upper solenoid output flag is set at the same time. Set the solenoid output flag and the upper right front solenoid output flag to the same extent, and tilt the main body (A) back.

In the condition flag clearing subroutine of step 1100, the control device (100) controls various glue short switches (LSWIL) to (L!V4L),
When (LSWIR) to (1, SW4R) are turned ON, the corresponding solenoid output flag is cleared to stop further output. For example, if the left front lower limit 5-lit switch (LSWIL) is separated into ON and ``1'',
The lower left front solenoid output flag is cleared and the right front upper limit switch (LSW2R) is determined to be ON.
Clear the right front upper solenoid output flag.

In addition, this condition flag clear subroutine is used to prevent the left and right crawler traveling devices (3L) and (3R) from crossing in side view, causing the aircraft body (8) to become unstable. In order to prevent the left side of the main body (A) from tilting downward toward the front and the right side tilting downward toward the rear, set the left front lower solenoid output flag, the right front upper solenoid output flag, or the left rear lower solenoid output flag. If the right rear upper solenoid output flag etc. are set at the same time, clear them.

[Another example]

In the previous embodiment, the crawler traveling device (3L), (3
The main body of the aircraft (A) is turned by applying braking force toward the turning center side of R), but there are cases where the aircraft turns with a speed difference between the outer side of the turn and the turning center side. It is possible to carry out the present invention even in the case where the turning center side is driven in the opposite direction to make the turn.

Furthermore, although the previous embodiments have been described only when the vehicle is moving forward, it is possible to implement the present invention even when the vehicle is moving backward.

In addition, in the previous embodiment, the right and left sides of the main body (A) are tilted forward and backward when turning, but the crawler traveling device (3L
) j (3R) may be constructed such that the wheels at the center of the front and back can be moved up and down, and the wheels on the center side of the turn are lowered when turning.

Furthermore, in the previous embodiment, the steering actuator (21) is operated in conjunction with the operation of the steering lever (l8), but the steering actuator (21) is operated in conjunction with the turning that is automatically performed on the headland. The actuator (2I) may be actuated.

The present invention can also be applied to work vehicles other than combines, such as transport vehicles and construction work vehicles.

Note that although reference numerals are written in the claims section for convenience of reference to the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the turning control device for a working vehicle according to the present invention, in which FIG. 1 is a functional block diagram of the turning control device, FIG. 2 is a main flow of the turning control device, and FIG. 3 is a subroutine for left turning processing. , Figure 4 is the subroutine for right turn processing, Figure 5
6 is a left side view of the crawler traveling device, FIG. 7 is a longitudinal sectional front view of the crawler traveling device, and FIG. 8 is a side view of the combine harvester. Further, FIG. 9(a) is an explanatory view of the action showing the turning state when moving forward, and FIG. 9(0) is an explanatory drawing of the action showing the turning state when moving backward. (A)...Airframe body, (21)...Steering means, (3L), (3R)...Crawler traveling device, (100)...・Position switching means. Figure 2

Claims (1)

[Claims] 1. A state in which a pair of left and right crawler traveling devices (3L) and (3R) supporting the main body (A) of the aircraft are driven at the same speed;
Based on a steering means (21) that switches to a turning state in which the steering wheel is driven at different speeds, or in mutually opposite directions, or only one side is driven, and a command to switch the steering means (21) to the turning state, A turning control device for a work vehicle, comprising an attitude switching means (100) for switching only a part of the grounding portion on the turning center side of the left and right crawler traveling devices (3L) and (3R) to a state in which only a part of the grounding portion is in contact with the ground. 2. The attitude switching means (100) connects the ground contact areas of the left and right crawler traveling devices (3L) and (3R) to the body of the aircraft (
The turning control device for a working vehicle according to claim 1, which is configured to tilt forward and backward with respect to A). 3. The turning control device for a working vehicle according to claim 1, wherein the attitude switching means (100) is configured to switch to a forward-sloping posture when moving forward and to a backward-sloping posture when moving backward.