JPH1159480A - Steering control device for crawler type mobile agricultural machine - Google Patents

Abstract

(57) [Summary] [Problem] When making a transition from a brake turn to a mild turn, perform a brake turn and perform a mild-turn clutch in a region where the pressure curve of the brake pressing pressure before the crawler inside the turn locks is gentle. By making connection, the transition from the brake turn to the mild turn is smooth. [Solution] In the brake turn, the side clutches 24L and 24R are disconnected at the rise A of the pressure rise curve, and the crawler inside the turning direction is locked in the mild turn. Slow Mild Clutch 32, 3
No. 3 before the end of the spin turn, where the pressure rise curve suddenly rises after the crawler inside the turning direction locks.
Connect the spin mild clutches 32 and 33 with.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering control device for a crawler type mobile agricultural machine such as a combine or a harvester.

[0002]

In the case of a crawler-type mobile agricultural machine, there are three ways to change the course of the machine. A brake turn that applies braking to one of the left and right crawlers, a spin turn that rotates the left and right crawlers in opposite directions, and a mild turn that drives one crawler in the same direction as the other crawler at a lower speed. . These three types of turn modes are selected according to the situation, the steering lever is tilted in the turning direction, and the switch is operated according to the tilt angle to execute these three types of turns.

[0003] In a mild turn, the rotation of the crawler on the inner side in the turning direction is reduced to one third of the rotation of the crawler on the outer side in the turning direction. If the clutch is connected during traveling and the rotation of the crawler inside the turning direction is suddenly reduced to 1/3, a large shock will occur. Therefore, first, a brake turn is executed to gradually reduce the rotation of the crawler inside the turning direction.

[0004] If the clutch connection of the mild turn is performed immediately after the brake turn, the rotation of the crawler is not sufficiently decelerated, so that the shock of the clutch connection is large. Further, even if the steering lever is slowly tilted to perform the alignment, the switch is activated and a mild turn is performed, which may cause a disconnection.

[0005] If a mild-turn clutch connection is performed after the rotation of the crawler inside the turning direction is completely stopped (locked) once, the speed is suddenly increased to 1/3 rotation from the stopped state. Connection shock is large.

Therefore, according to the present invention, when the steering lever is tilted to shift from a brake turn to a mild turn, the brake turn is executed and the pressure increase curve of the brake pressing pressure before the crawler inside the turn locks is gentle. The purpose of the present invention is to make the transition from the brake turn to the mild turn smooth by performing the mild-turn clutch connection in the area.

[0007]

In order to achieve the above object, the present invention is configured as follows.

In other words, there are at least two types of turn modes: a brake turn for applying a brake to one of the right and left crawlers, and a mild turn for driving one of the left and right crawlers in the same direction as the other crawler at a lower speed. When performing a mild turn, on a crawler-type mobile agricultural machine that executes a brake turn and then shifts to a mild turn, a steering lever that tilts left and right to control the turning direction of the aircraft and the execution of a mild or brake turn A brake pressing pressure increasing means for tilting the steering lever to increase the brake pressing pressure, a mild turn timing switch for determining a mild turn clutch connection timing, and the mild turn timing switch to the steering lever. Mild turn that operates by tilting When shifting from the brake turn to the mild turn by tilting the steering lever, the pressure increase curve of the brake pressing pressure just before the crawler inside the turn locks is provided when the steering lever is tilted. A steering control device characterized in that a mild-turn clutch connection is performed in a gentle area.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a combine provided with a steering control device according to the present invention.

Reference numerals 10L and 10R denote left and right crawlers of the combine, and 11L and 11R denote left and right crawler drive shafts. Numeral 12 denotes a mowing part and numeral 13 denotes a threshing part.

Reference numeral 14 denotes a transmission which transfers the power of an engine (not shown) to the left and right crawlers 10L, 10R.
To be transmitted.

FIG. 2 shows the transmission 14.

The input shaft 15 to which the power of the engine is input,
A high-speed gear 16 and a low-speed gear 17 integrated therewith are mounted movably in the axial direction. The high-speed gear 16 and the low-speed gear 17 are connected to a shifter fork (not shown).

An intermediate shaft 18 includes a first transmission gear 19 and a second transmission gear 19.
The transmission gear 20 and the third transmission gear 21 are fixed to each other, and the high-speed gear 16 and the low-speed gear 17 are selectively engaged with the first transmission gear 19 and the second transmission gear 20, respectively.

Reference numeral 22 denotes a side clutch / brake shaft provided downstream of the intermediate shaft 18, and brakes 23L,
3R is installed. Furthermore, left and right brakes 23L, 23R
Left and right side clutch (claw clutch)
24L and 24R are provided.

The left and right side clutches 24L, 24R are
It is always energized by a spring and always connects the driving side and the passive side. Then, the brakes 23L and 23R and the clutch 24
Shifters 25L and 25R are provided between L and 24R, and these are loosely fitted to the side clutch / brake shaft 22. Shifter 2
Shifter shafts 26L and 26R are connected to 5L and 25R.
In order to disengage the side clutches 24L and 24R, the passive side is separated by a hydraulic circuit described later against the urging force of the spring.

Reference numeral 27 denotes a spin rotating integrally with the driving side.
With mild output gear, side clutch / brake shaft 22
Stick to

Further, the left and right side clutches 24L, 2L
The fifth transmission gear 28 and the sixth transmission gear 28 are integrally formed on the passive side of the 4R, respectively.
The transmission gear 29 is loosely fitted. In addition, a center gear 30 that always meshes with the third transmission gear 21 is fixed to the side clutch / brake shaft 22.

Reference numeral 31 denotes a spin / mild shaft, which is provided with spin / mild clutches 32 and 33 on the left and right sides thereof, and a switching clutch 34 is spline-coupled to a center portion so as to be laterally movable. On the left and right of the switching clutch 34, a mild input gear 3 is provided.
5 and the spin input gear 36 are loosely fitted to the spin / mild shaft 31, and the mild input gear 35 is always meshed with the spin / mild output gear 27.

The switching clutch 34, the mild input gear 35, and the spin input gear 36 are formed with mutually engageable and disengageable engagement teeth. The eighth transmission gear 37 is connected to the left spin mild clutch 32, the ninth transmission gear 38 is connected to the right spin mild clutch 33, and the eighth transmission gear 37 and the ninth transmission gear 38 are connected to the left and right clutches. It is loosely fitted on the mild shaft 31.

Reference numeral 39 denotes a spin / mild reduction shaft, which is connected to the tenth transmission gear 40 which is always meshed with the eighth transmission gear 37.
The twelfth transmission gear 42 which is fixed to the transmission gear 41 and always meshes with the ninth transmission gear 38 is fixed to the thirteenth transmission gear 43. Then, the eleventh transmission gear 41 and the thirteenth transmission gear 43
Is loosely fitted to the spin / mild reduction shaft 39.

Reference numeral 44 denotes a reduction shaft, a fourteenth transmission gear 45 which always meshes with the tenth transmission gear 40, and a twelfth transmission gear 42.
The 15th transmission gear 46 which always meshes with the reduction shaft 44 is loosely fitted.

Further, the first transmission gear 45 has a first
The sixth transmission gear 47 and the seventeenth transmission gear 46
The transmission gears 48 are loosely fitted to the reduction shafts 44, respectively. First
The sixth transmission gear 47 always meshes with the fifth transmission gear 28,
The seventh transmission gear 48 always meshes with the sixth transmission gear 29.

A reverse rotation gear 49 which always meshes with the spin / mild output gear 27 and a first rotation
Nine transmission gears 50 are loosely fitted to the reduction shafts 44, respectively. Further, the nineteenth transmission gear 50 and the spin input gear 36 always mesh.

The twentieth transmission which is always meshed with the fourteenth transmission gear 45
The transmission gear 51 is fixed to the left crawler drive shaft 11L, and the 21st transmission gear 52, which always meshes with the fifteenth transmission gear 46, is fixed to the right crawler drive shaft 11R.

FIG. 3 shows a steering section of the steering control device.

A connecting plate 56 is fixed to the lower end of the steering lever 55, and a plate portion 57 is formed on the bottom surface of the connecting plate 56. Connecting plate 5
6 swings on the frame portion 58 of the aircraft with the tilting of the steering lever 55. Left and right steering lever position detection switches 59L and 59R are provided in the frame portion 58.

A projection 6 is formed on the bottom of the central portion of the plate portion 57.
0 is formed, and one end of the rod 61 is connected to the protrusion 60.
The other end of the rod 61 is connected to a turning plate 62, and an end of the turning plate 62 is supported by a support shaft 63. Spring 6 on rotating plate 62
One end of the rod 4 is connected to pull the rod 61 downward.

An operating piece 65 is fixed to the side surface of the rotating plate 62, and the operating piece 65 is connected to the
The mild execution switch 67 can be contacted. The variable aperture switch 66 and the spin / mild execution switch 67
It is arranged on the body in proximity to the rotating plate 62. The spin / mild execution switch 67 operates at a position where the tilt of the steering lever 55 is larger than that of the variable aperture switch 66.

A spin turn timing switch 97 and a mild turn timing switch 9 are arranged in parallel with the variable aperture switch 66 and the spin / mild execution switch 67.
8, and the operating piece 65 is connected to the spin turn timing switch 97 and the mild turn timing switch 9.
8 can be contacted. Spin turn timing switch 97 and mild turn timing switch 98
It is fixed to the same machine frame close to the rotating plate 62. The spin turn timing switch 97 operates at a position where the tilt of the steering lever 55 is larger than the mild turn timing switch 98.

Next, the two hydraulic systems will be described with reference to the circuit diagram of the main hydraulic system of FIG. 4 and the circuit diagram of the spin-mild hydraulic system of FIG. 5 provided in the steering control device.

In the main hydraulic system, a hydraulic pump 73 is connected to the oil tank 72, and a pressure control valve 75 is connected to the hydraulic pump 73 via a filter 74.

A check valve 76 is provided in parallel with the filter 74.
Is provided between the filter 74 and the pressure control valve 75.
7 is connected. A first switching valve 78 and a second switching valve 78
The switching valve 79 is connected, and the left and right brake cylinders 80L and 80R are connected to the first switching valve 78. The oil tank 72 and a cylinder (not shown) are connected to the second switching valve 79, and when these cylinders are operated, the second switching valve 7
9 is switched to the right state.

A third switching valve 81 is connected to the brake cylinders 80L and 80R, and a variable throttle 83 and a fixed throttle 84 are connected to the third switching valve 81. Variable diaphragm 83 and fixed diaphragm 84
Is connected downstream of the pressure control valve 75 (see FIG. 4).

In the spin-mild hydraulic system, a hydraulic pump 87 is connected to an oil tank 85 via a suction filter 86. A fourth switching valve 88 is connected to the hydraulic pump 87, and the fourth switching valve 88 is connected to the fourth switching valve 88 via a first throttle 89.
The mild fifth switching valve 90 is connected. The left and right spin / mild clutches 32 and 33 are connected to the spin / mild fifth switching valve 90 via a second throttle 91 and a third throttle 92, respectively (see FIG. 5).

FIG. 6 is a connection diagram of the spin / mild controller 94 of the steering control device. On the input side, left and right steering lever position detection for detecting the left and right positions of the steering lever 55 shown in FIG. Switches 59L and 59R, a spin turn mode switch 95 for detecting the position of the spin turn of the turn mode switching lever shown in FIG. 7, a mild turn mode switch 96 for detecting the position of the mild turn,
A spin turn timing switch 97 for determining the clutch connection timing of the spin turn, a mild turn timing switch 98 for determining the clutch connection timing of the mild turn, and a spin / mild execution switch 67 for executing the spin / mild turn shown in FIG. Respectively.

Then, on the output side of the controller 94,
Left and right clutch solenoids 78S of the first switching valve 78
(L), (R) and the left and right spin / mild clutch solenoids 90S of the spin / mild fifth switching valve 90
(L) and (R) are connected to the pressure relief solenoid 81S of the third switching valve 81, respectively.

Next, the operation will be described.

First, a description will be given of a brake turn to the right as an example.

The power of the engine is transmitted from the input shaft 15 via the intermediate shaft 18 to the third transmission gear 21, and further from the third transmission gear 21 via the center gear 30.
The power is transmitted to the brake shaft 22.

When the steering lever 55 is tilted to the right (in the direction of arrow A in FIG. 3), the connecting plate 56 is tilted to separate the plate portion 57 from the right steering lever position detection switch 59R, and the signal of the position detection switch 59R is output. Is sent to the controller 94. If no signal is input from both the spin turn mode switch 95 and the mild turn mode switch 96, the spin / mild controller 94 determines that the mode is the brake turn mode.

According to the control output of the controller 94, the right clutch solenoid 78S (R) is operated to switch the first switching valve 78 to the right operating position (see FIG. 4), and the brake cylinder 80R is operated via the shifter shaft 26R. Shifter 2
Move 5R and disengage the right side clutch 24R.
As a result, transmission of power from the side clutch / brake shaft 22 to the reduction shaft 44 is cut off.

The rod 61 is pulled upward by the tilting of the steering lever 55, and the operation piece 65 rotates about the support shaft 63 integrally with the rotating plate 62. When the steering lever 55 is tilted left or right, the rod 61 is pulled upward, and the rotating plate 62 rotates in the direction of the arrow about the support shaft 63 (see FIG. 3).

The third switching valve 81 is connected to the variable throttle 83 at the normal position (the upper state of the third switching valve 81 in FIG. 4). At this time, the variable aperture switch 66 is pressed by the operating piece 65 in accordance with the tilt of the steering lever 55, and the variable aperture 83
And adjust the pressure of the brake 23R. By applying the brake 23R, the rotation of the sixth transmission gear 29 is braked, and the seventeenth transmission gear 48, the fifteenth transmission gear 4
The right crawler drive shaft 11R is braked via the sixth and twenty-first transmission gears 52 (see FIG. 2).

Next, the right spin turn will be described.

First, the mode switching lever is switched to the spin turn position, and the signal of the spin turn mode switch 95 is input to the spin mild controller 94.

In this case, the process proceeds to the spin turn via the state of the right brake turn. The steering lever 55 is tilted to the right, the variable aperture switch 66 is depressed, and the spin piece execution switch 67 is turned on by the operation piece 65, and the signal of the spin mild execution switch 67 is sent to the controller 94 for spin mild. The controller 94 operates the pressure release solenoid 81S to switch the third switching valve 81 to the operating state (the lower state of the third switching valve 81 in FIG. 4). Then, the third switching valve 81 is set to the fixed throttle 84
Side to release the pressure of the right brake 23R. At this time, the left side clutch 24L is in the engaged state.

Then, the spin / mild output gear 27 rotates integrally with the driving side of the left side clutch 24L, and the nineteenth transmission gear 50 rotates via the reverse rotation gear 49. Here, the switching clutch 34 is engaged with the spin input gear 36, and rotates the spin / mild shaft 31 by the rotation of the nineteenth transmission gear 50 via the spin input gear 36.

Here, while the engine is running, the fourth switching valve 88
Is switched to the left, and the respective signals of the position detection switch 59R, the spin mild execution switch 67 and the spin turn timing switch 97 cause the controller 94 to operate the right spin mild clutch solenoid 90S (R), The spin / mild fifth switching valve 90 is switched to the left (see FIG. 5), and the right spin / mild clutch 33 is engaged.

Thus, the spin / mild axis 31
Of the ninth transmission gear 38, the twelfth transmission gear 42, and the fifteenth transmission gear 46 by the spin mild clutch 33.
And the right crawler drive shaft 11R through the 21st transmission gear 52 to reverse the right crawler.

On the other hand, the forward rotation is transmitted to the left crawler drive shaft 11L in the same manner as when traveling straight, so that the aircraft turns.

The 17th transmission gear 46 and the 17th transmission gear
The transmission gear 48 also rotates with the right side clutch 2
Since 4R is in the cut-off state, the sixth transmission gear 29 rotates freely.

Next, a rightward mild turn will be described.

The rightward mild turn is performed via the rightward brake turn state in the same manner as the spin turn.

When the mode switching lever is switched to the mild turn position, a signal is input from the mild turn mode switch 96 to the spin / mild controller 94.

Next, similarly to the spin turn, the steering lever 5
5 is tilted to the right, and the spin / mild execution switch 67 is pressed. Then, the third switching valve 81 is switched to the operating state (the lower state of the third switching valve 81 in FIG. 4), and the third switching valve 81 is connected to the fixed amount throttle 84 to release the pressure of the right brake 23R. . Note that the right side clutch 24R is off in the state of the brake turn.

Therefore, the power is transmitted from the input shaft 15 to the side clutch / brake shaft 22 in the same manner as during the spin turn. Since the spin / mild output gear 27 is integrated with the center gear 30, the spin / mild output gear 27 always rotates regardless of whether the left side clutches 24L and 24R are engaged or disengaged. The switching clutch 34 has a mild input gear 35.
To transmit the rotation of the spin / mild output gear 27 to the spin / mild shaft 31 via the mild input gear 35.

Here, the controller 94 switches the spin / mild fifth switching valve 90 to the left state by the respective signals of the position detection switch 59R, the spin / mild execution switch 67 and the mild turn timing switch 98, and Is engaged (see FIG. 4).

Then, the rotation of the spin / mild shaft 31 is transmitted to the right crawler drive shaft 11R via the ninth transmission gear 38, the twelfth transmission gear 42, the fifteenth transmission gear 46, and the twenty-first transmission gear 52. The fifteenth transmission gear 4
The 17th transmission gear 48 integral with 6 rotates together, but the sixth transmission gear 29 freely rotates because the right side clutch 24R is in the disengaged state. Also, the left crawler drive shaft 11
Transmission of power to L is the same as when traveling straight.

As described above, the right crawler 11R travels later in the same direction than the left crawler 11L due to the difference in gear ratio between the right transmission path and the left transmission path, so that the aircraft turns right.

The steering control device of the present invention has the above-described configuration, and has the spin turn timing switch 97 and the mild turn timing switch 98 fixed to the same machine frame, and the steering lever 55 is tilted to operate the operating piece. At 65, each switch is pressed. FIG. 8 shows the pressure rise curves of the brakes 23L and 23R corresponding to the tilt angle of the steering lever 55, and the positions of the clutch engagement and disengagement of the brake turns, mild turns and spin turns and the positions of the crawler locks in the pressure rise curves. The brake turn is the rising A of the pressure rise curve
The side clutches 24L and 24R are disengaged, and in the mild turn, the pressure rise curve before the crawler inside the turning direction locks is gradual B and the spin mild clutch 32 is used.
In the spin turn, the spin mild clutches 32 and 33 are connected just before the end C where the boosting curve after the crawler inside the turning direction is locked sharply rises.
At the clutch connection position B of the mild turn, the rotation of the crawler on the inner side in the turning direction falls to about １ ／ of the rotation of the crawler on the outer side in the turning direction.

Next, a description will be given of a vehicle height control device of an agricultural work vehicle that automatically returns the vehicle height to the original height when the vehicle moves from reverse to forward after the ABU operation in relation to the present invention. ABU means that when a farm work vehicle moves backwards through a wetland, the front and rear sides of a vehicle body that leans forward due to a driving reaction force are inclined forward and backward (pitching control), and the left and right sides of the vehicle body are simultaneously raised (rolling control). This is a system that sufficiently raises the height of the front reaping section with respect to the ground to prevent the reaping section from hitting the ground by a driving reaction force.

FIG. 9 shows a connection circuit of the vehicle height control device. The connection circuit includes, on the input side of the controller 100, a cutting grain culm sensor 101, a cutting / clutching position sensor 1
02, left and right rolling sensors 103L, 103R, pitching sensor 104, reverse switch 105, and
The ABU switch 106 is connected, and the left and right rolling switching valve solenoids 107L and 107R and the pitching switching valve solenoid 108 are connected to the output side.

FIG. 10 shows a hydraulic circuit of the vehicle height control device. The hydraulic circuit drives the hydraulic pump P to switch the left and right rolling switching valves 9L and 9R to extend or shorten the double-acting left and right rolling cylinders 5L and 5R. Further, the pitching switching valve 8 is switched to operate the pitching cylinder 7.

This vehicle height control device is configured as described above.
The left and right rolling sensors 103L and 103R and the pitching sensor 104 detect the vehicle height and the front, rear, left and right inclinations, and extend and contract the left and right rolling cylinders 5L and 5R and the pitching cylinder 7 to maintain the horizontal posture and the vehicle height of the vehicle body.

This vehicle height control device switches the reverse switch 105 after the ABU operation to move from reverse to forward and resumes mowing. When the mowing section is lowered, the mowing grain culm sensor 1
01 and the signal from the cutting / unclutching position sensor 102, the maximum vehicle height raised during ABU is maintained while the mowing unit is at or above a predetermined height and does not detect a grain culm to be mowing. Then, when the reaping unit descends to a predetermined height, the vehicle height is automatically returned to the original height set by the operator before the ABU operation, and normal vehicle body level control is performed from there.

In the conventional ABU, when moving from reverse to forward or neutral, the maximum vehicle height is maintained, so that the center of gravity of the vehicle body becomes high, the vehicle becomes susceptible to the driving reaction force, and the vehicle height is reduced to the original value. There is a problem that a troublesome manual operation is required to return to the position each time. This vehicle height control device automatically returns the vehicle height to the original height when moving from reverse to forward after the ABU operation. Therefore, these problems are solved, and the vehicle height is not increased more than necessary. Therefore, it is easy to perform the "alignment" in which the direction of the machine body is adjusted and the reaper is aligned with the stripe.

Next, a description will be given of a vehicle height control device for an agricultural work vehicle that holds the maximum vehicle height and tilts the vehicle body forward when moving from reverse to forward after the ABU operation.

This vehicle height control device switches the reverse switch 105 after the ABU operation to move from reverse to forward and resumes mowing. When the mowing section has risen to a certain height or higher, the mowing grain is removed. Until the culm to be cut is detected based on the signals from the culm sensor 101 and the cutting / clutching position sensor 102, the vehicle body is tilted forward while maintaining the maximum vehicle height raised during ABU. Then, when the grain stem to be harvested is detected, normal body level control is performed from there.

In a clay-type wetland where the soil is poorly cut,
Since the crawler has settled and the mowing portion has risen above a certain height, when the mowing is advanced and the mowing is performed, the rear portion of the vehicle body sinks due to the driving reaction force, and it is difficult to adjust the mowing height. This vehicle height control device holds the maximum vehicle height and leans the vehicle body forward when moving from reverse to forward after the ABU operation. Therefore,
Since the center of gravity of the vehicle body moves forward to suppress the backward leaning posture due to the driving reaction force, the cutting height can be adjusted smoothly.

[0072]

When a mild turn is performed, immediately after the brake turn is executed or when the rotation of the crawler inside the turning direction is completely stopped once, the clutch connection shock is large. The steering control device according to the present invention performs a mild-turn clutch connection in a region where the brake pressing pressure before the locking of the crawler inside the turn is gradual by executing the brake turn. Therefore, according to the present invention, the transition from the brake turn to the mild turn becomes smooth. In addition, since the clutch is not engaged in a mild turn at a tilt angle of the steering lever that is approximately equal to the alignment, there is no problem in performing a direction correction such as an out of alignment.

[Brief description of the drawings]

FIG. 1 is an overall side view of a combine of the present invention.

FIG. 2 is a longitudinal sectional view of a combine transmission according to the present invention.

FIG. 3 is an explanatory diagram of a steering unit of the steering control device according to the present invention.

FIG. 4 is a hydraulic circuit diagram of a main hydraulic system of the steering control device according to the present invention.

FIG. 5 is a hydraulic circuit diagram of a hydraulic system for spin mild of the steering control device according to the present invention.

FIG. 6 is a connection diagram of a spin mild controller of the steering control device according to the present invention.

FIG. 7 is an explanatory diagram of a turn mode switching lever.

FIG. 8 is a diagram showing a pressure increase curve and a clutch connection position of each turn.

FIG. 9 is a connection circuit diagram of the vehicle height control device.

FIG. 10 is a hydraulic circuit diagram of the vehicle height control device.

[Explanation of symbols]

 Reference Signs List 5 rolling cylinder 7 pitching cylinder 8 pitching switching valve 9 rolling switching valve 10 crawler 11 crawler drive shaft 12 cutting unit 13 threshing unit 14 transmission 15 input shaft 16 high-speed gear 17 low-speed gear 18 intermediate shaft 19 first transmission gear 20 second transmission gear Reference Signs List 21 third transmission gear 22 side clutch / brake shaft 23 brake 24 side clutch 25 shifter 26 shifter shaft 27 spin mild output gear 28 fifth transmission gear 29 sixth transmission gear 30 center gear 31 spin mild shaft 32, 33 spin mild Clutch 34 Switching clutch 35 Mild input gear 36 Spin input gear 37 8th transmission gear 38 9th transmission gear 39 Spin / mild reduction shaft 40 10th transmission gear 41 11th transmission gear 42 12th transmission gear 43 th transmission gear 44 reduction shaft 45 14th transmission gear 46 15th transmission gear 47 16th transmission gear 48 17th transmission gear 49 reverse gear 50 19th transmission gear 51 20th transmission gear 52 21st transmission gear 55 steering lever 56 Connecting plate 57 Plate portion 58 Frame portion 59 Steering lever position detection switch 60 Projection 61 Rod 62 Rotating plate 63 Support shaft 64 Spring 65 Working piece 66 Variable throttle switch 67 Spin / mild execution switch 72 Oil tank 73 Hydraulic pump 74 Filter 75 pressure control valve 76 check valve 77 diverting valve 78 first switching valve 79 second switching valve 80 brake cylinder 81 third switching valve 83 variable throttle 84 fixed throttle 85 oil tank 86 suction filter 87 hydraulic pump 88 fourth switching valve 89 First throttle 90 Fifth switching valve 91 Second throttle 92 Third LI 94 Spin / mild controller 95 Spin turn mode switch 96 Mild turn mode switch 97 Spin turn / timing switch 98 Mild turn / timing switch 100 Controller 101 Cutting culm sensor 102 Cutting / clutch position sensor 103 Rolling sensor 104 Pitching sensor 105 Reverse switch 106 ABU switch 107 Rolling switching valve solenoid 108 Pitching switching valve solenoid

Claims (1)

[Claims] At least two types of turn modes are provided: a brake turn for braking one of the right and left crawlers, and a mild turn for driving one of the right and left crawlers at a lower speed in the same direction as the other crawler. When performing a mild turn, on a crawler-type mobile agricultural machine that executes a brake turn and then shifts to a mild turn, a steering lever that tilts left and right to control the turning direction of the aircraft and the execution of a mild or brake turn A brake pressing pressure increasing means for tilting the steering lever to increase the brake pressing pressure; a mild turn timing switch for determining a mild turn clutch connection timing; and the mild turn timing switch to the steering lever. Mild turn timing that works by tilting When the transition from the brake turn to the mild turn is performed by tilting the steering lever, the pressure increase curve of the brake pressing pressure just before the crawler inside the turning is locked by executing the brake turn is provided. Steering control device for performing mild-turn clutch connection in a safe area.