JPH09172814A - Steering control device for crawler type mobile agricultural machine - Google Patents

Abstract

(57) Abstract: [Problem] To provide a steering control device for quickly executing a one-side braking turn with a small turning radius by tilting a steering lever deeply while turning by selecting a one-side deceleration turn mode. SOLUTION: When the steering lever is tilted to the left, for example, in the one-side deceleration turn mode, first, the left lever direction detection switch 8
4L and the lever tilt angle detection sensor 85 are the controller 8
1, the controller 81 operates the reverse rotation / deceleration switching clutch 66 to perform deceleration drive on the left crawler 11 and turn left. When the steering lever is further tilted at this point, the lever tilt angle detection sensor 85 detects this and the turn mode automatic switching means incorporated in the controller 81 causes the reverse rotation / deceleration switching clutch 66.
And the brake 39 is activated. As a result, the one-way deceleration turn can be swiftly changed to the one-side braking turn with a small turning radius by simply tilting the steering lever. Therefore, a desired course change can be swiftly and safely avoided while avoiding danger.

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 changing the course of a mobile agricultural machine such as a combine or a harvester which is driven by a crawler.

[0002]

In a crawler-type mobile agricultural machine, in order to change the course, one side deceleration turn for decelerating one side crawler in the same direction as the opposite side crawler and a certain proportion from that is provided for the one side crawler. There is a one-sided braking turn to apply only the braking, and depending on the situation, either the one-sided deceleration turn with a large turning radius or the one-sided braking turn with a small turning radius can be selected with the turn mode switching lever. If this happens, there is the annoyance of having to operate the switching lever again even while the aircraft is turning.

Particularly, when it is necessary to change the turning radius to a small value during turning by selecting the one-side deceleration turn, the switching lever must be switched to the one-side braking turn.
If the switching operation is delayed, there is a risk that the aircraft will not move and bend with a large turning radius and may collide with an obstacle.

The present invention solves such a problem. During one-side deceleration turn, by simply tilting the steering lever, it is possible to quickly shift to the one-side braking turn with a small turning radius, so that The objective is to ensure driving safety by simplifying the course change operation.

[0005]

According to the present invention, a one-side braking turn for braking a crawler on one side or a one-side deceleration turn for driving a crawler on one side in the same direction as a crawler on the other side at a low speed, or an arbitrary turn mode. In the crawler type mobile agricultural machine that changes the course of the machine by selecting, turn mode selection means for selecting one side braking turn or one side deceleration turn,
Steering lever that selects the turning direction of the aircraft, right or left, lever movement amount detection means that detects the amount of movement of the steering lever, and if the one-side deceleration mode is selected, the amount of movement of the steering lever is a predetermined value. When there is a deviation from the one-side deceleration mode, a turn mode automatic switching means for shifting from one-side deceleration turn to one-side braking turn is provided based on the detection signal from the lever movement amount detection means. It is characterized in that when it is moved further, braking is applied to the crawler on the side driven at a low speed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention are shown in FIGS.

11 is a combine crawler, 12L,
Reference numeral 12R indicates the left and right crawler drive shafts. 13 is a reaper,
14 is a threshing part.

FIG. 2 is a developed transverse sectional view of a transmission for transmitting power of an engine (not shown) to the left and right crawlers 11, 11.

The engine power is input to the pump 16 of the hydrostatic continuously variable transmission (HST) via the input pulley 15, and the HST pump 16 drives the HST motor 17.

Reference numeral 18 is an input shaft of the transmission,
It is connected to the output side of the HST motor 17. The first transmission gear 19 is fixed to the input shaft 18.

Reference numeral 20 denotes a speed change shaft arranged downstream of the input shaft 18, and an outer peripheral cylinder 21 is rotatably fitted to the outer circumference of the speed change shaft 20. A low speed gear 22, a medium speed gear 23 and a high speed gear 24 are spline-coupled to the outer peripheral cylinder 21. Low speed gear 22,
The middle-speed gear 23 and the high-speed gear 24 rotate integrally and laterally move on the outer peripheral cylinder 21 by a fork member (not shown). The high speed gear 24 always meshes with the first transmission gear 19.

A shifter 25 having an annular groove formed on the outer periphery thereof is spline-joined to the outer peripheral cylinder 21, and the shifter 2 is provided.
5, the cutting clutch 26 is provided at the right end of the transmission shaft 20.
And a claw clutch is formed between the input side of the reaping clutch 26 and the shifter 25. The output side of the reaping clutch 26 is connected to the transmission shaft 20. 28 is a shifter fork that moves the shifter 25.

A pulley 30 is fixed to the right end of the transmission shaft 20, and power is transmitted from the pulley 30 to the mowing section 13 via a mowing clutch 26.

Reference numeral 31 denotes a first intermediate shaft, which is arranged downstream of the speed change shaft 20 and has a second intermediate gear 32, a third intermediate gear 33, and a fourth intermediate gear 34 fixed to the first intermediate shaft 31. The second transmission gear 32 meshes with the low speed gear 22, the third transmission gear 33 meshes with the medium speed gear 23, and the fourth transmission gear 34 meshes with the high speed gear 24.
Mesh with.

A second intermediate shaft 35 is arranged downstream of the first intermediate shaft 31. The fifth transmission gear 3 is provided at the center of the second intermediate shaft 35.
6 is fixed, and the sixth transmission gear 37 is attached to the right end of the second intermediate shaft 35.
To fix. The sixth transmission gear 37 always meshes with the fourth transmission gear 34.

A control shaft 38 is arranged downstream of the input shaft 35.

The control shaft 38 is provided with a brake 39 at the left end and left and right switching clutches 40, 41 at the center. The driving side of the left and right switching clutches 40 and 41 is fixed to the control shaft 38, and the passive side is loosely fitted. Engaging teeth 40a and engaging teeth 40b are formed facing each other on the driving side and the passive side of the left switching clutch 40, respectively.

Similarly, the right switching clutch 41 also has engagement teeth 41a and 41b formed on the driving side and the passive side thereof. Then, the left switching gear 42 and the right switching gear 43 are fixed to the passive sides of the left and right switching clutches 40 and 41, respectively.

The brake 39 is in the form of a disk and comprises a brake body 44 and a brake case 45. The brake body 44 is fixed to the control shaft 38, and the brake case 45 is fixed to the transmission case. The brake 39 has a structure in which integral discs (not shown) on the brake body side and integral discs (not shown) on the brake case side are alternately arranged.

A clutch shaft 46 is arranged downstream of the control shaft 38. A straight traveling gear 47 is fixed to the center of the clutch shaft 46, and a left output gear 48 and a right output gear 49 are loosely fitted to the clutch shaft 46 on the left and right sides of the straight traveling gear 47, respectively. Left and right side clutches 50, 51 are formed between the straight traveling gear 47 and the output gears 48, 49.

Each of the side clutches 50 and 51 is composed of an engaging tooth 48a on the output gear 48 side, an engaging tooth 49a on the right output gear 49 side, and an engaging tooth 47a on the rectilinear gear 47 side opposite thereto. To do. Each output gear 48 and 49 is
The spring 52 urges the straight gear 47 side.

The left output gear 48 is always meshed with the left switching gear 42 and laterally moves integrally with the left switching gear 42. And
The seventh transmission gear 53 is fixed to the left output gear 48. Similarly, the right output gear 49 always meshes with the right switching gear 43 and laterally moves integrally with the right switching gear 43. Eighth transmission gear 54
Is fixed to the right output gear 49.

For example, as shown in FIG.
The engaging tooth 47a of the left output gear 48 is separated from the engaging tooth 47a of the left output gear 48, and the engaging tooth 40b on the passive side of the left switching clutch 40 engages with the engaging tooth 40a on the driving side.
0 is entered.

Further, the engaging tooth 47a of the straight-moving gear 47 is engaged with the engaging tooth 49a of the right output gear 49, and the passive side engaging tooth 41b of the right switching clutch 41 is changed from the driving side engaging tooth 41a. When separated, the right switching clutch 41 is disengaged.

Grooves are formed in the seventh transmission gear 53 and the eighth transmission gear 54, and fork members 57L and 57R each having a pin 57p engaging with the groove are provided. And
The 15th transmission gear 55 is constantly meshed with the 7th transmission gear 53,
The tenth transmission gear 56 is constantly meshed with the eighth transmission gear 54. The ninth transmission gear 55 is fixed to the left crawler drive shaft 12L, and the tenth transmission gear 56 is fixed to the right crawler drive shaft 12R.

Next, the submission 58 for the reverse rotation turn and the one-sided deceleration turn will be described with reference to FIG.

Reference numeral 59 is an auxiliary input shaft, the tip of which is the input shaft 35.
Insert the plug into one end of the shaft so that both shafts can be connected on the same axis. A moving gear 60 is splined to the auxiliary input shaft 59, and the moving gear 60 is moved left and right by the shifter fork 61.

Reference numeral 62 denotes a reduction shaft, which is arranged downstream of the auxiliary input shaft 59, to which a reduction gear 63 and a seventeenth transmission gear 64 are fixed. The reduction gear 63 can be engaged with and disengaged from the moving gear 60.

Reference numeral 65 is a reverse / deceleration control axis, which is an auxiliary input axis 59.
Of the control shaft 38, and the tip of the control shaft 38 is freely inserted into and removed from the control shaft 38 so that both shafts are connected on the same axis. The reverse rotation / deceleration control shaft 65 is provided with a reverse rotation / deceleration switching clutch 66, and the eighteenth transmission gear 67 adjacent to the reverse rotation / deceleration switching clutch 66 is loosely fitted to the reverse rotation / deceleration control shaft 65. Seventeenth
The transmission gear 64 always meshes with the eighteenth transmission gear 67 (see FIG. 3).

The reverse rotation / deceleration switching clutch 66 is of a disc type and is composed of a clutch body 68 and a clutch case 69. The disc 68d integrated on the clutch body 68 side and the disc 69d integrated on the clutch case 69 side are alternately arranged. is there. The clutch body 68 is spline-coupled to the reverse / reduction control shaft 65, and the clutch case 69 is coupled to the eighteenth transmission gear 67.

Next, the hydraulic system will be described with reference to FIG.

A hydraulic pump 72 is connected to the oil tank 70 via a suction filter 71, and the hydraulic pump 72 is connected to a first directional control valve 74 via a filter 73. Further, the first pressure control valve 75 is connected between the filter 73 and the first directional control valve 74.

The first directional control valve 74 is connected to the second directional control valve 76 and the third directional control valve 77, and the left and right push cylinders 78L and 78R are connected to the second directional control valve 76. Further, the second directional control valve 76 is connected to a directional control valve (not shown) that operates the mowing unit 13 and the like.

The left and right push cylinders 78L and 78R are connected to the fourth directional control valve 79, and the fourth directional control valve 79 is connected to the reverse rotation / deceleration switching clutch 66 and the brake 39.
A second pressure control valve 80 is connected between the left and right push cylinders 78L, 78R and the fourth directional control valve 79. A steering lever is connected to the second pressure control valve 80.

If the valves such as the directional control valve and the pressure control valve used in the hydraulic circuit are intensively arranged in the rear frame of the combine, especially below the swing shelf outlet of the threshing section, maintenance and management can be performed. It is easy and convenient.

A reverse rotation turn mode detection switch 82, a one-side deceleration mode detection switch 83, left and right lever direction detection switches 84L and 84R, and a lever tilt angle detection sensor 85 are connected to the input side of the controller 81 of the steering control device. (See FIG. 5).

On the output side of the controller 81, the left and right first solenoids 86 and the second solenoid 86 of the second directional control valve 76 are provided.
The solenoid 87 and the third solenoid 88 of the fourth directional control valve 79 are connected to each other.

The reverse rotation turn mode detection switch 82 determines whether the mode switching lever is switched to the reverse rotation turn position, and the one-side deceleration mode detection switch 83 determines whether the mode switching lever is switched to the one-side deceleration turn. Detect each. When the reverse rotation turn mode detection switch 82 and the one-side deceleration mode detection switch 83 do not output the detection signal of the reverse rotation turn or the one-side deceleration turn, the one-side braking turn is performed.

Here, the mode switching lever, the reverse rotation turn mode detection switch 82 and the one-side deceleration mode detection switch 83 (not shown) constitute a turn mode selection means, and the lever tilt angle detection sensor 85 constitutes a lever movement amount detection means. .

The turn mode automatic switching means is incorporated in the controller 81 of the steering control device.

Next, the operation will be described by taking the one-sided deceleration turn in the left direction as an example.

When the engine is started, the first directional control valve 74 shown in FIG. 4 is switched, and a constant amount of oil is supplied to the second directional control valve 7.
6

The power of the engine is the HST pump 16 and the HS.
It is transmitted to the input shaft 18 via the T motor 17, and the first transmission gear 19 and the high speed gear 24 rotate. Then, the low speed gear 22 (or the medium speed gear 23, the high speed gear 24) rotates,
The first intermediate shaft 31 rotates via the second transmission gear 32 (or the third transmission gear 33, the fourth transmission gear 34).

The rotation of the first intermediate shaft 31 depends on the rotation of the fourth transmission gear 3
It is transmitted to the second intermediate shaft 35 via the fourth and sixth transmission gears 37. The rotation of the second intermediate shaft 35 causes the auxiliary input shaft 59 to rotate integrally.

The mode switching lever is operated to the one-side deceleration turn mode, and the shifter fork 61 engages the moving gear 60 and the reduction gear 63 (see FIG. 3). Further, the steering lever is tilted to the left, and this tilt angle is detected by the lever tilt angle detection sensor 85. Then, when the tilting angle of the steering lever is less than a certain angle, the one-side deceleration turn is executed.

The rotation of the auxiliary input shaft 59 causes the moving gear 6 to move.
0, the reduction gear 63, the reduction shaft 62, the seventeenth transmission gear 64, and the eighteenth transmission gear 67 rotate.

The left lever direction detection switch 84L
Sends a signal to the controller 81 to excite the right second solenoid 87 by the controller 81 to switch the second directional control valve 76 from the neutral state to the right state. This activates the push cylinder 78L on the left side, and
The solenoid 88 is operated to switch the fourth directional control valve 79 to the left side in the figure. As a result, the reverse rotation / deceleration switching clutch 6
6 is operated to transmit the power transmitted to the eighteenth transmission gear 67 to the control shaft 38 via the reverse rotation / deceleration switching clutch 66.

At this time, the push cylinder 78L presses one end of the fork member 57L, and the pin 57p provided at the other end moves the seventh transmission gear 53. Then, the left output gear 48 is moved to disengage the left side clutch 50, and at the same time, the left switching clutch 40 is engaged (see FIG. 6). Accordingly, the rotation of the control shaft 38 rotates from the driving side of the left switching clutch 40 to the passive side, and the left switching gear 42, the left output gear 48, the seventh transmission gear 53, and the ninth transmission gear that rotate integrally with the passive side. Left crawler shaft 1 through 55
Rotate 2L.

On the other hand, the right switching clutch 41 is disengaged and the right side clutch 51 is engaged. Second intermediate shaft 35
Rotation of the fifth transmission gear 36, the rectilinear gear 47, the right output gear 49, the eighth transmission gear 54, and the tenth transmission gear 56.
The crawler shaft 12R on the right side is rotated via.

In this way, one side deceleration turn is executed,
Due to the difference in the gear ratio between the right power transmission path and the left power transmission path, the left crawler 11 travels in the same traveling direction and slower than the right crawler 11, so the aircraft turns to the left with a large turning radius. . Then, when it is desired to make the turning radius smaller than the one-side deceleration turn, the steering lever is further tilted by a certain angle or more. A signal from the lever tilt angle detection sensor 85 is supplied to the controller 81 by this tilting of the steering lever, and the third solenoid 88 is demagnetized by the turn mode automatic switching means incorporated in the controller 81 to operate the fourth directional switching valve 79. The state is switched to the right side, the reverse rotation / deceleration switching clutch 66 is disengaged, and the brake 39 is operated.

The tilting of the steering lever adjusts the second pressure control valve 80 to adjust the braking force of the brake 39. The control shaft 38 is braked by the brake 39, and the left crawler shaft 12L is braked via the left switching clutch 40, the left switching gear 42, the left output gear 48, the seventh transmission gear 53, and the ninth transmission gear 55. As a result, the vehicle continues to turn leftward from a large turning radius of the one-side deceleration turn and a small turning radius of the one-side braking turn.

When the steering lever is set to a tilting angle less than a certain angle, the controller 81 turns off the brake 39 to operate the reverse rotation / deceleration switching clutch 66 to execute a one-sided deceleration turn.

The operation of the one-sided deceleration turn to the right is the same as in the case of the left.

As described above, in the first embodiment, in the one-side deceleration turn mode, the one-side deceleration turn or the crawler 11 on the inside of the turn can be braked and turned by the tilting angle of the steering lever.

Therefore, in the one-side deceleration turn turn mode, when it is necessary to urgently avoid danger such as collision with an obstacle, the one-side deceleration turn can be performed by a simple operation to increase the tilt of the steering lever. It is possible to avoid danger by executing a one-side braking turn with a smaller turning radius.

Next, another example related to the present invention will be described.

This example relates to an improvement in the case where the mode is switched to the reverse rotation turn or the one-side deceleration turn during the one-side braking turn.

In order to switch the mode between the reverse rotation turn and the one-side deceleration turn during the one-side braking turn, the brake pressure is released to raise the pressure of the reverse / deceleration switching clutch 66. If this pressure rise is slow, the vehicle turns. The radius expands. In particular, in the case of a wet field, the load of the crawler 11 is large and the clutch is slippery, so that the swelling of the turning radius easily occurs.

Therefore, in this example, the pressure-reception-side area Sc of the reverse rotation / deceleration switching clutch 66 is designed to be larger than the pressure-reception-side area Sb of the brake 39, and the reverse rotation / deceleration switching clutch 6 is designed.
The connection pressure of 6 is increased to prevent the reverse rotation / deceleration switching clutch 66 from slipping during mode switching.

This is shown in FIG.

The reverse rotation turn mode detection switch 82, the one-side deceleration mode detection switch 83, the left and right lever direction detection switches 84L and 84R, and the changeover switch 105 are connected to the input side of the controller 106 of the steering control device.
Further, on the output side of the controller 81, the first solenoid 86 and the second solenoid 8 on the left and right of the second directional control valve 76 are provided.
7 and the third solenoid 88 of the fourth directional control valve 79 are connected to each other.

As the hydraulic circuit, the same hydraulic circuit as that of the embodiment of the present invention is used.

For example, when the mode switching lever is switched to the one-side deceleration turn and a turn mode switching button (not shown) is pressed during one-side braking turn, the turn mode is switched to the one-side deceleration turn, the one-side deceleration mode detection switch 83 and the changeover switch. The signal of 105 is input to the controller 106.

As a result, the third solenoid 88 is demagnetized and the fourth directional control valve 79 is switched to the right side in the figure to brake 39.
Operate. Then, the second pressure control valve 80 is adjusted by tilting the steering lever to brake the control shaft 38, and the left switching clutch 40, the left switching gear 42, the left output gear 48, the seventh transmission gear 53, and the ninth transmission gear 55. Left crawler shaft through
Braking 2L.

Next, the third solenoid 88 is operated to switch the fourth directional control valve 79 from the right side state to the left side state and the reverse rotation / deceleration switching clutch 66 is operated. The power transmitted to the control shaft 38 via the reverse rotation / deceleration switching clutch 66 is the left switching clutch 40, the left switching gear 42, the left output gear 48,
The left crawler shaft 12L is rotated via the seventh transmission gear 53 and the ninth transmission gear 55.

At this time, pressure is applied to the pressure receiving side 66a of the reverse rotation / deceleration switching clutch 66, and the disc 68d on the clutch body 68 side is moved to the clutch case 69 by the piston 66b.
It contacts the disk 69d on the side.

Therefore, a larger amount of oil than that supplied to the brake 39 is supplied to the reverse rotation / deceleration switching clutch 66, and the piston 66b is pushed with a strong pressure to turn on the reverse rotation / deceleration switching clutch 66. Therefore, slippage of the reverse rotation / deceleration switching clutch 66 is reduced and power can be transmitted reliably and promptly to shift to the one-side deceleration turn.

Also, when the mode is switched to the reverse rotation turn, slippage of the reverse rotation / deceleration switching clutch 66 is reduced, and the reverse rotation turn can be surely and swiftly performed.

FIG. 9 shows an improved example of the hydraulic circuit of the switching clutch.

In the hydraulic circuit of FIG. 4, since the pressure for operating the brake 39 and the pressure for pushing the push cylinders 78L, 78R are the same, if the tilting angle of the steering lever is small,
Pushing rod push force is weak, switching clutch 4
There was a problem that it was difficult for 0 and 41 to enter. Therefore, FIG.
Then, by connecting the throttle 108 between the R port of the push cylinders 78L and 78R and the P port of the second pressure control valve 80, the pushing force of the push rod is strengthened.

Further, in the hydraulic circuit of FIG. 4, the third direction control valve 78 connected to the reverse rotation / deceleration switching clutch 66 and the brake 39 is a two-position switching system. There was a problem that the aircraft was strongly impacted in the lateral direction by changing its direction.

Therefore, in the modified example of FIG. 10, the three-direction directional control valve 109 having the neutral position as the third directional control valve 109 is used.
Use Thus, in the automatic directional control, the directional control valve 109 is set to the neutral position, the push cylinders 78L and 78R are operated in this state, and only the switching clutch is turned on and off without operating the brake, whereby the directional control is smoothly performed. it can.

By the way, when the amount of the combined grain paddy tank increases, the weight of the machine body increases, so that the turning radius becomes large, and it is not possible to turn at a desired turning radius, or when the turning radius is small, in the reverse turn, The centrifugal force that acts may become too great.

Therefore, when the paddy tank is full and the speed of the machine is a safe speed equal to or lower than a certain level, even if one-side braking turn or one-side deceleration turn is selected, if the reverse rotation is forcibly executed, the turning radius is The bulge can be avoided.

FIG. 11 shows an improved example in which safety is aimed at from such a viewpoint.

The controller 110 of FIG. 11 has a reverse rotation turn mode detection switch 82, a one-side deceleration mode detection switch 83, and left and right lever direction detection switches 84 on the input side.
L, 84R, speed sensor 111 and paddy tank sensor 11
2 is connected, and the left and right first solenoids 86 and second solenoids 87 of the second directional control valve 76 and the third solenoid 88 of the fourth directional control valve 79 are connected to the output side.

When the control is started (S1), a signal from the paddy tank sensor 112 is input to the controller 110 (S2), and it is determined whether the paddy tank is full (S3). If the paddy tank is not full, the paddy tank sensor 11 is repeatedly used.
The signal No. 2 is input to the controller 110.

When the paddy tank is full, it is determined whether the turn mode is the one-side deceleration turn or the one-side braking turn (S4).
For one-side deceleration turn or one-side braking turn, speed sensor 1
11 to supply a signal to the controller 110 (S
5). Then, it is determined whether or not the speed of the machine body is equal to or higher than a predetermined speed (S6). When the speed is equal to or higher than the predetermined speed, one-side deceleration turn or one-side braking turn is executed according to the selected turn mode (S7). If the speed is lower than the predetermined speed, the reverse turn is executed (S8).

As a result, even if the paddy tank is full,
A desired turning can be performed without increasing the turning radius. Further, it is safe because the reverse rotation is not executed when the speed is higher than a predetermined value.

Next, FIG. 13 shows a conventional hydraulic circuit.

A hydraulic pump 122 is connected to the oil tank 120 via a filter 121, and a cutting switch valve 123 is connected to the hydraulic pump 122 via the filter 121.
The cutting cylinder 125 is connected to the cutting switching valve 123 via the pilot check valve 124, and the cutting switching valve 123 is connected to the auger switching valve 126. The auger switching valve 126 is connected to the auger cylinder 127 via the pilot check valve 124, and the auger switching valve 126 is connected.
Is connected to the fourth directional control valve 128. The left and right push cylinders 129L and 129R are connected to the fourth directional control valve 128, and the left and right push cylinders 129L and 129R are connected to the fifth directional control valve 130. Fifth direction control valve 13
The reverse rotation / deceleration switching clutch 131 and the brake 132 are connected to 0.

Left and right push cylinders 129L, 129
A pressure control valve 133 is connected between R and the fifth directional control valve 130, and the pressure control valve 133 is connected to the oil tank 120.
The above pumps, valves, cylinders, etc. are connected by a high-pressure hose.

Next, FIG. 14 shows the arrangement of the components of the hydraulic circuit of FIG. 13 on the combine.

Among these, the high-pressure side cutting switch valve 12
3. Since the auger switching valve 126 is located away from the hydraulic pump 122, the length of the hose to the oil tank 120 becomes long. Therefore, the unloading pressure of the mowing switching valve 123 and the auger switching valve 126 is increased due to the pressure loss of the hose, the oil temperature is increased, the durability of the pump is reduced due to the increased load on the pump, and the cavitation at a low temperature is further increased. Good parts will occur.

Therefore, in FIG. 15, unlike the conventional case, the positions of the mowing switching valve 123 and the auger switching valve 126 are arranged near the oil tank 120.

Therefore, the pressure loss of the hose can be reduced, the unloading pressure can be lowered, the oil temperature can be prevented from rising, and the occurrence of cavitation at low temperatures can be prevented.

Further, in the conventional hydraulic circuit of FIG. 13, the mowing switching valve 123, the auger switching valve 126 and the fourth
The direction control valve 128 is connected in series via a hose.

Therefore, here, as shown in FIG.
In addition to the second directional control valve 76 of the hydraulic circuit of FIG. 4, the mowing switching valve 135 and the auger switching valve 138 are connected by a high-pressure hose, and the third directional control valve 77 is connected to the mowing switching valve 135 and the auger. The switching valve 138 is connected by a high pressure hose.

In addition, the mowing switch valve 135 is attached to the check valve 13.
6, the mowing cylinder 137 is connected by the high pressure hose, and the auger switching valve 138 is connected by the high pressure hose to the auger cylinder 139 via the check valve 136. The second directional control valve 76, the mowing switching valve 135, and the auger switching valve 138 are connected in parallel with the third directional control valve 77. Therefore, the second directional control valve 7
6. Mowing switching valve 135 and auger switching valve 13
The unloading pressure of each of 8 can be lowered.

Further, as shown in FIG. 15, the positions of the mowing switching valve 135 and the auger switching valve 138 are arranged near the tank (see parentheses in FIG. 15).

As a result, the pressure loss of the high-pressure hose can be reduced, the unloading pressure can be lowered, the oil temperature can be prevented from rising, and cavitation can be prevented from occurring at low temperatures. Further, the pipes of the auger switching valve 138 and the auger cylinder 139, which are less frequently used, can be reduced in diameter to reduce the cost.

[0092]

According to the present invention, the movement amount (tilt angle) of the steering lever is changed during the course change in the turn mode of the one-side deceleration turn.
When is increased, the turn mode automatic switching means receives a signal from the lever movement amount detecting means and executes a one-side braking turn in which the crawler on the inside of the turn is braked. As a result, the one-side deceleration turn mode and the one-side braking turn are switched only by tilting the steering lever.

Therefore, in an emergency, even if the mode switching lever is not operated, the angle of the steering lever is largely tilted, and the one-side deceleration turn to the one-side braking turn with a small turning radius are executed to avoid danger and quickly and quickly. The desired diversion can be executed safely.

[Brief description of the drawings]

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

FIG. 2 is an exploded transverse sectional view of the transmission of the combine shown in FIG.

FIG. 3 is a vertical sectional view of the submission.

FIG. 4 is a hydraulic circuit diagram thereof.

FIG. 5 is a connection diagram of the controller.

FIG. 6 is a sectional view illustrating the operation of the push cylinder.

FIG. 7 is a partial cross-sectional view showing the brake and the reverse rotation / deceleration switching clutch of FIG.

FIG. 8 is a connection diagram of a controller of a reference example.

FIG. 9 is a hydraulic circuit diagram of a reference example.

FIG. 10 is a hydraulic circuit diagram of another reference example.

FIG. 11 is a connection diagram of a controller of still another reference example.

FIG. 12 is a flowchart of another reference example.

FIG. 13 is a hydraulic circuit diagram of another reference example.

FIG. 14 is a layout view on a combine of a hydraulic device of another reference example.

15 is an improved layout of the hydraulic device of FIG.

FIG. 16 is a hydraulic circuit diagram of another reference example.

[Explanation of symbols]

 11 Crawler 12L, 12R Crawler drive shaft 39 Brake 40, 41 Switching clutch 47 Straight gear 48, 49 Left and right output gears 50, 51 Side clutch 66 Reverse / deceleration switching clutch 76 Second direction control valve 77 Third direction control valve 78 Push Cylinder 79 Fourth direction control valve 81, 106, 110 Controller 82 Reverse rotation turn mode detection switch 83 One side deceleration mode detection switch 84 Lever direction detection switch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiko Uemura 1 Yakura, Tobe-cho, Iyo-gun, Ehime Izeki Agricultural Machinery Co., Ltd. Department

Claims (1)

[Claims] 1. A course of an airframe by selecting an arbitrary turn mode, one-side braking turn for braking one crawler and one-side deceleration turn for driving one crawler in the same direction as the other crawler at a low speed. In a crawler-type mobile agricultural machine that changes the direction, turn mode selection means that selects one side braking turn or one side deceleration turn, a steering lever that selects the right or left turning direction of the machine, and the amount of movement of the steering lever is detected. When the lever movement amount detection means and the one-side deceleration mode are selected, if the movement amount of the steering lever exceeds a predetermined value, the one-side deceleration turn shifts to one-side braking turn based on the detection signal of the lever movement amount detection means. Turn mode automatic switching means, and when the steering lever is moved in the turning direction to a position larger than a predetermined position during the one-sided deceleration mode, the crawler on the side driven at a low speed. Steering control apparatus characterized by multiplying against braking.