JPH11187720A - Steering operation structure in paddy working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject structure capable of suitably performing the turning run on butt by placing a decelerating differential gear which differentiates the right and the left rear wheels during the turning run. SOLUTION: The objective structure is obtained by placing a decelerating differential gear B which differentiates the right and left rear wheels 6 by forcibly reducing the speed of the driving of the rear wheel 6 at the turning inner side during turning run. Further, in said structure, the decelerating differential gear B can be linked to a steering mechanism A through an interlocking operation mechanism C so that the decelerating differential gear B interlocks the motion larger than a specified degree toward the turning direction of the steering mechanism A to forcibly reduce the driving speed of the rear wheel 6 at the turning inner side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering operation structure for a paddy field working vehicle such as a rice transplanter or a direct sowing machine for working in a paddy field.

[0002]

2. Description of the Related Art Conventionally, in the above-described steering operation structure of a paddy field work vehicle, each of the left and right rear wheel transmission systems is provided with a clutch / brake mechanism linked to corresponding left and right operation pedals. When traveling back and forth in a paddy field, the turning operation of the steering wheel in the turning direction and the depressing operation of the operation pedal inside the turning are performed as the vehicle reaches the headland, thereby disengaging the clutch and brake mechanism inside the turning. A headland turning run with a small turning radius that makes it easy to move to the starting end position of the next planting running row by stopping the rear wheel inside the turning and displaying the state and the braking state. It had been.

[0003]

However, if the rear wheel inside the turning is stopped during the headland turning as in the prior art, scraping of mud by the rear wheel inside the turning will occur. Therefore, there are problems such as damaging the field and adversely affecting the headland work after the reciprocating work, or making it difficult to perform smooth headland turning in a muddy or hard paddy field. Was.

An object of the present invention is to provide a steering operation structure for a paddy field working vehicle that can suitably perform headland turning.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, in a steering operation structure of a paddy field work vehicle, a rear inner wheel is forcibly turned during turning. The steering operation structure of a paddy field work vehicle equipped with a speed reduction differential that differentially drives the right and left rear wheels by performing a deceleration drive.

According to the first aspect of the invention, during turning, the deceleration differential device forcibly drives the rear wheels inside the turning to decelerate, so that the left and right rear wheels are moved rearward inside the turning. Since the wheels are driven at a lower driving speed than the rear wheels on the outer side of the turning, the wheels can be differentially driven, so that the turning can be performed with a small turning radius. Then, it is possible to easily move the next planting traveling train to the start end position. Also, during the turning, the rear wheel inside the turning is gradually moved by forcibly decelerating the rear wheel inside the turning, so that the rear wheel inside the turning is used during the headland turning. Can be prevented from being scraped off by the rear wheel inside the turning, which is caused when the drive is stopped.
Damage the field during headland turning, or adversely affect headland work after reciprocating work,
In addition to avoiding such inconveniences, a smooth headland turning operation can be performed even in a muddy or hard paddy field.

[0007] By the way, during turning, for example, it is conceivable to move the rear wheel inside the turning by setting the rear wheel in a non-driving / non-braking state to follow the turning. In this case, in a muddy paddy field, etc. Since the rear wheel easily loses propulsive force due to the resistance of the mud and does not move, the mud is scraped by the rear wheel inside the turning. On the other hand, in the first aspect of the present invention, since the rear wheel inside the turning is forcibly decelerated at the time of turning, the rear wheel inside the turning is moved even in a muddy paddy field. Therefore, a smooth headland turning operation without damaging the field can be performed.

[Effect] Accordingly, a steering operation structure of a paddy field work vehicle capable of performing a suitable headland turning operation in which scraping of mud by a rear wheel inside the turning operation is prevented can be provided.

According to the second aspect of the present invention,
2. The deceleration differential device according to claim 1, wherein the deceleration differential device forcibly decelerates and drives a rear wheel inside the turning in conjunction with an operation of a steering mechanism in a turning direction by a predetermined amount or more. The differential device and the steering mechanism are interlockingly connected by an interlocking differential operation mechanism.

According to the second aspect of the present invention, in conjunction with the operation of the steering mechanism in the turning direction by a predetermined amount or more, the speed reduction differential device forcibly drives the rear wheels inside the turning to decelerate. Then, since the left and right rear wheels are driven in a state in which the rear inner wheel is driven at a lower driving speed than the rear rear wheel, the left and right rear wheels are driven in the turning direction like a headland turning. During a turning operation in which a steering operation of a predetermined amount or more is performed, the deceleration differential device is automatically operated without performing a dedicated operation for operating a deceleration differential device different from the steering operation together with the steering operation. As a result, a deceleration differential state in which the rear wheel inside the turning is forcibly driven to decelerate can be exhibited.

[Effect] Accordingly, in a small turning operation such as a headland turning operation, an operation is performed when a deceleration differential state in which the rear wheel inside the turning is forcibly decelerated by the operation of the deceleration differential device. It is possible to provide a steering operation structure for a paddy field work vehicle having excellent operability.

According to the third aspect of the present invention,
3. The deceleration amount adjusting means according to claim 2, wherein the interlocking differential operation mechanism changes and adjusts the deceleration amount of the rear inner wheel by the deceleration differential device with respect to the operation amount of the steering mechanism in the turning direction. Equipped.

According to the third aspect of the present invention, the drive torque of the rear inner wheel during turning can be changed according to the state of the running road surface, and the like. In this case, it is possible to perform an appropriate small turning operation in consideration of the above. For example, when the vehicle is traveling on a road where traveling resistance is smaller than when traveling in paddy fields, if the amount of deceleration of the rear wheels on the inside of the turn by the reduction gear differential with respect to the amount of operation in the turning direction of the steering mechanism is reduced, Since the drive difference between the wheel and the rear wheel on the outside of the turn is small and it is difficult to make a small turn, the amount of deceleration of the rear wheel on the inside of the turn by the speed reduction differential with respect to the amount of operation in the turning direction of the steering mechanism is increased. By increasing the drive difference between the rear wheel inside the turning and the rear wheel outside the turning, favorable small turning traveling can be performed when traveling on the road. Conversely, when traveling in paddy fields where traveling resistance is greater than when traveling on roads, the amount of deceleration of the rear wheels inside the turning by the deceleration differential with respect to the amount of operation of the steering mechanism in the turning direction is the same as when traveling on roads. When it is increased, the driving torque of the rear wheel inside the turning becomes too small to be in a state close to driving stop, and it is possible to satisfactorily prevent mud scraping by the rear wheel inside the turning during headland turning. Since there is a possibility that the driving force of the steering mechanism in the turning direction may be reduced, the amount of deceleration of the rear wheel on the inside of the turn by the speed reduction differential device with respect to the amount of operation in the turning direction of the steering mechanism is reduced to increase the driving torque of the rear wheel on the inside of the turn. It is possible to perform a favorable small turning travel, that is, a headland turning travel in which no mud scraping by the rear wheel inside the turning occurs during traveling. In addition, when traveling resistance is further increased, such as in a muddy paddy field, the amount of deceleration of the rear wheels on the inner side of the turn by the reduction gear differential with respect to the amount of operation in the turning direction of the steering mechanism is further reduced, and If the driving torque of the rear wheel is further increased, it is possible to perform a favorable headland turning operation in which mud is not scraped off by the rear wheel inside the turning even in a muddy paddy field.

[Effects] Accordingly, it is possible to provide a steering operation structure for a paddy field working vehicle capable of performing an appropriate small turning run in consideration of the state of the running road surface.

According to the fourth aspect of the present invention,
In the invention according to claim 2 or 3, the interlocking differential operating mechanism is provided with interlocking state switching means for switching between a state in which the deceleration differential device and the steering mechanism are interlocked and a state in which they are not interlocked.

According to the fourth aspect of the present invention, in a situation where it is not desired to make a small turn such as a left turn or a right turn while traveling on a road, the deceleration differential is performed by the interlocking state switching means. By switching to a state where the device and the steering mechanism are not interlocked, in conjunction with the operation of the steering mechanism in the turning direction by a predetermined amount or more,
It is possible to prevent a small turning traveling state in which the rear wheel inside the turning is forcibly decelerated and driven from appearing unnecessarily.

[Effect] Accordingly, the steering operation of a paddy field vehicle with excellent steering operability can be switched between a state in which a small turning travel appears and a state in which a small turning travel does not appear in conjunction with the steering operation according to the traveling situation. A structure can be provided.

According to the fifth aspect of the present invention,
The invention according to any one of claims 1 to 4, wherein the reduction gear differential comprises a friction clutch and a brake provided on each of the right and left rear wheel transmission systems, and Left and right clutches linked to the operation pedals
It consists of a brake mechanism, and the half-clutch state of the clutch / brake mechanism inside the turn is revealed during turning.

According to the fifth aspect of the present invention, the speed reduction differential is constituted by a clutch and a brake which are originally provided in the left and right rear wheel transmission systems of a paddy working vehicle such as a rice transplanter. In addition, by adopting a friction type clutch as the clutch, a transmission (for example, a gear type transmission, a hydrostatic The deceleration drive of the rear wheel on the inside of the turn by showing the half-clutch state of the clutch on the inside of the turn during turning, without newly installing a continuously variable transmission or belt-type continuously variable transmission. Therefore, even in a paddy field, it is possible to perform a favorable small turning travel without scraping of mud by the rear wheel inside the turning.

[Effect] Accordingly, a paddy field capable of performing a suitable small turning run which can prevent scraping of mud by a rear wheel inside the turning side during turning in the paddy field, while simplifying the configuration and reducing the manufacturing cost. It has become possible to provide a steering operation structure for a work vehicle.

According to the sixth aspect of the present invention,
In the invention according to claim 5, the interlocking differential operation mechanism is provided with a spring that is elastically deformed by the operation of the steering mechanism in a turning direction.

According to the sixth aspect of the present invention, since the clutch / brake mechanism is biased to return the clutch to the incoming side and the brake to the non-braking side, the spring provided in the interlocking differential operating mechanism is provided. If a non-transmission / non-braking state of the clutch / brake mechanism is elastically deformed at a value smaller than the return biasing force to the clutch engagement side in the clutch / brake mechanism when the non-transmission / non-braking state is developed,
It is possible to prevent the clutch / brake mechanism from switching to the non-transmission / non-braking state and the braking state due to the operation of the steering mechanism in the turning direction. In other words, the steering mechanism and the clutch / brake mechanism are linked by the interlocking differential operation mechanism so that the clutch / brake mechanism inside the turn shows a half-clutch state in conjunction with the operation of the steering mechanism in the turning direction by a predetermined amount or more. The interlocking setting by the interlocking differential operation mechanism at the time of interlocking connection can be facilitated.

Also, the spring provided in the interlocking differential operating mechanism may be elastically deformed at a value smaller than the biasing force for returning the clutch / brake mechanism to the non-braking side when the braking state of the clutch / brake mechanism appears. If the clutch / brake mechanism is switched to the non-transmission / non-braking state by the operation of the steering mechanism in the turning direction, the clutch / brake mechanism is switched to the braking state. Can be prevented. Further, as a spring provided in the interlocking differential operation mechanism, the elastic deformation starts at a value smaller than the return urging force to the brake non-braking side in the clutch / brake mechanism, and during the elastic deformation, the return urging force is reduced. By adopting a material having a characteristic of being elastically deformed at a large value, it is possible to prevent the clutch / brake mechanism from being switched to the braking state until the steering mechanism is being operated in the turning direction, and to have the steering mechanism The interlocking differential operating mechanism can be set so that the clutch / brake mechanism switches to the braking state during the operation of the mechanism in the turning direction.

[Effect] Accordingly, a steering operation structure of a paddy working vehicle is provided, in which the interlocking differential operation mechanism can easily set the interlocking between the steering mechanism and the clutch / brake mechanism, and can improve the versatility. I can do it.

According to the seventh aspect of the present invention,
The invention according to claim 5 or 6, wherein the headland turning detection means for detecting a transition to headland turning travel, and the clutch and the clutch by operating the operation pedal based on the detection from the headland turning detection means. It is equipped with a braking prevention mechanism for preventing the appearance of the braking state of the brake mechanism.

According to the seventh aspect of the present invention, at the time of headland turning, the braking state of the clutch / brake mechanism is operated by operating the operation pedal by operating the braking prevention mechanism based on the detection from the headland turning detecting means. The half-clutch state of the clutch / brake mechanism can be easily operated even when the steering mechanism and the clutch / brake mechanism are not interlocked by the interlocking differential operation mechanism. It becomes easy to appear. Conversely, when the steering mechanism and the clutch / brake mechanism are interlockingly connected by the interlocking differential operation mechanism, even if the driver accidentally depresses the operation pedal during headland turning, the clutch It is possible to prevent the braking state of the brake mechanism from appearing. That is,
By the operation of the brake prevention mechanism, it is possible to easily and reliably prevent the clutch / brake mechanism from being brought into a braking state by operating the operation pedal when turning the headland, and thus, the mud generated by the rear wheel inside the turn. It is possible to perform a good headland turning operation without scraping.

[Effect] Therefore, regardless of the interlocking / non-interlocking of the steering mechanism and the clutch / brake mechanism, a paddy field that can easily and reliably perform a good headland turning operation without mud scraping by the rear wheel inside the turning operation. It has become possible to provide a steering operation structure for a work vehicle.

[0028]

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

FIG. 1 shows a riding type rice transplanter which is an example of a paddy field work vehicle. In this rice transplanter, a seedling planting device 2 is provided at a rear portion of a traveling machine body 1 with a link mechanism 3 and a hydraulic cylinder 4. It is configured as a mid-fertilization type by connecting the fertilizer device 14 to the rear of the traveling machine body 1 while freely connecting the elevator via a lift.

The traveling body 1 is provided with an engine 8 and an engine 8 at the front of a body frame 7 having a pair of left and right driven front wheels 5 and a pair of left and right driven rear wheels 6. A transmission / planting transmission case 10 in which power is transmitted via a belt-type continuously variable transmission 9 is mounted, and a passenger driving unit 1A
The steering wheel 11 and the driver's seat 12 are attached to the front wheel 5 which constitutes a vehicle.

The seedling plant 2 is a feed case 2 to which the power after shifting via the transmission case 10 is transmitted.
A, power from feed case 2A is planted transmission case 2
Planting mechanism 2C transmitted via B, seedling table 2D that slides back and forth at a predetermined pitch relative to planting mechanism 2C,
And a leveling float 2E that performs a leveling operation in advance on a planting location by the planting mechanism 2C.

The fertilizer applicator 14 is equipped with a hopper 14A for storing fertilizer, a feeding mechanism 14B for feeding the fertilizer from the hopper 14A by a predetermined amount by being driven by the power after shifting through the transmission case 10, and a leveling float 2E. Groover 14C, groover 14 from feeding mechanism 14B.
A guide hose 14D that guides the fertilizer over C, an electric blower 14E that pressurizes the fertilizer fed by the feeding mechanism 14B toward the groove generator 14C, and the like, in synchronization with the planting operation of the seedling planting apparatus 2. It is configured to apply fertilizer.

As shown in FIGS. 1 to 5, the rear wheel 6 is attached to the body frame 7 via a rear axle case 22. The rear axle case 22 includes a cylindrical transmission case portion 25 having an input shaft 24 which is operatively connected to a power take-out shaft 10 a for driving the rear wheels of the transmission case 10 via a transmission shaft 23, and a left-right-facing posture. And left and right gear case portions 26L and 26R connected to the left gear case portion 26L. A left axle 27L for the left rear wheel 6 is provided at a lower end portion of the left gear case portion 26L.
A right axle 27R for the right rear wheel 6 is supported at the lower end of the right gear case 26R. And a left rear wheel transmission system extending from the input shaft 24 to the left axle 27L;
Each of the right rear wheel transmission systems extending from the input shaft 24 to the right axle 27R includes a friction type clutch 29 and a brake 30, and the corresponding left and right operation pedals 28L, 2
Left and right clutch / brake mechanism 15 linked to 8R
L, 15R are equipped. Left and right operation pedals 28
L and 28R are provided at the right foot of the passenger driving section 1A, and are provided with a hook 28b provided on the right operation pedal 28R with an engagement arm 28a provided on the left operation pedal 28L so as to be able to swing. By engaging with, it can be connected so as to be integrally operated.

Left and right clutch / brake mechanisms 15L, 1
The 5R clutch 29 is connected to the input shaft 24 by the bevel gear mechanism 3.
1 between the lateral transmission shaft 32, which is transmission-connected via the first transmission shaft 1, and the left and right lateral passive shafts 33, which are transmission-connected to the left axle 27L and the right axle 27R, respectively. This is a multi-plate type that is interposed so that a transmitting state and a non-transmitting state in which the power is transmitted can appear. 4 and 5 will be described in detail.
As shown in (1), a sliding transmission body 34 that rotates integrally with the lateral transmission shaft 32 while being relatively slidable in the axial direction with respect to the transmission shaft 32 is mounted. A clutch housing 35 that rotates integrally with the laterally-directed passive shaft 33 in a state where the clutch is not relatively slidable in the axial direction with respect to the laterally-driven passive shaft 33 is mounted. Sliding transmission 3
4, a plurality of transmission clutch discs 36 which are integrally rotated while being relatively slidable in the axial direction with respect thereto are mounted. The clutch housing 35 is provided with a plurality of passive clutch disks 37 that rotate integrally with the clutch housing 35 while being relatively slidable in the axial direction. Transmission clutch disk 36 and passive clutch disk 3
7 is a receiving member 40 attached to the clutch housing 35.
And a pusher 41 provided on the sliding transmission body 34 are disposed so as to be alternately located in the axial direction. A support member 39 for rotatably supporting the clutch housing 35 is attached to a shaft end of the lateral transmission shaft 32 via a bolt 38.
1 between the transmission clutch disc 36 and the passive clutch disc 37 in a direction in which the transmission clutch disc 36 and the passive clutch disc 37 are pressed against each other.
A plurality of disc springs 42 for moving and biasing are disposed.
Left and right operation pedals 28L, 28
By the depressing operation of R, a shift operation is performed on the lateral transmission shaft 32 toward the sliding transmission body in the axial center direction via the shift fork 43 supported on the cylindrical transmission case portion 25 so as to be able to swing left and right. A release member 45 that presses and moves the sliding transmission body 34 in the pressure releasing direction against the urging force of the disc spring 42 via the bearing 45a is fitted externally. Reference numeral 43A in FIG. 5 denotes a left and right linkage mechanism including a rod 44A and the like so that the corresponding left and right operation pedals 28L and 28R actuate the shift fork 43 to the sliding transmission side in accordance with the stepping operation thereof. The arms are interlocked and connected via 44.

With the above-described structure, the clutch 29 is moved in the direction in which the sliding transmission member 34 is pressed by the biasing of the disc spring 42 so as to press the transmission clutch disk 36 and the passive clutch disk 37 into contact with each other. A transmission state (drive state for driving the rear wheel 6) in which power is transmitted from the drive shaft 32 to the lateral passive shaft 33 appears, and the left and right operation pedals 28L, 28
When the R is depressed, the sliding transmission body 34 is
By moving the release clutch member 45 through the release member 45 in the direction of releasing the pressure contact between the transmission clutch disk 36 and the passive clutch disk 37 against the bias of 2, the transmission is performed from the lateral transmission shaft 32 to the lateral passive shaft 33. A non-transmission state in which the rear wheel 6 is not driven (a non-drive state in which the rear wheel 6 is not driven) can appear.

As shown in FIG. 4, the brakes 30 of the left and right clutch / brake mechanisms 15L and 15R act on the clutch housing 35 to apply a braking force to the lateral passive shaft 33. More specifically, the cylindrical transmission case portion 25 is provided with a plurality of fixed brake disks 46 which are slidable relative to each other in the axial direction and non-rotatable.
Is attached. In the clutch housing 35,
On the other hand, a plurality of rotating brake discs 47 which are integrally rotated so as to be relatively slidable in the axial direction are attached. The fixed brake disc 46 and the rotary brake disc 47 are fitted inside the ends of the cylindrical transmission case section 25 and are prevented from coming off by contact with the left and right gear case sections 26L, 26R. A ring-shaped restricting member 48 for restricting the movement of the shutter 47 toward the gear case portion, and a brake operating portion 49 formed at an end of the release member 45 on the gear case portion side.
Are arranged alternately in the axial direction. That is, the brake 30 is disposed concentrically outside the clutch 29.

With the above arrangement, the release member 45 is moved toward the cylindrical transmission case portion (opposite the sliding transmission member) by the bias of the disc spring 42 via the sliding transmission member 34 to regulate the brake 30. By releasing the pressing and holding of the fixed brake disc 46 and the rotary brake disc 47 with the tool 48, a non-braking state in which the fixed brake disc 46 and the rotary brake disc 47 are not pressed against each other appears,
After depressing the left and right operation pedals 28L, 28R, the non-transmission state of the clutch 29 is displayed against the bias of the disc spring 42, and then the left and right operation pedals 28L, 28R are further depressed.
Is depressed to move the release member 45 toward the gear case portion (sliding transmission body side) against the urging of the disc spring 42, and the fixed brake disc 46 and the rotary brake disc 47 By pressing and holding, a braking state in which the fixed brake disc 46 and the rotary brake disc 47 are pressed against each other can appear.

That is, the left and right clutch / brake mechanisms 1
5L and 15R are set such that when the release member 45 is moved to the sliding transmission body side by depressing the left and right operation pedals 28L and 28R, the brake 30 is operated after the non-transmission state of the clutch 29 appears. Has been
With this setting, when performing a left turn, in addition to the normal left turn performed by steering the steering handle 11 in the left turn direction, the steering handle 11 is steered in the left turn direction and the left By depressing the operation pedal 28L of
While the right rear wheel 6 is driven at a predetermined speed, the transmission to the left rear wheel 6 is cut off, and the left rear wheel 6 can be braked and stopped. When turning, the steering wheel 11 is steered in the right turning direction in addition to the usual right turning running by steering the steering wheel 11 in the right turning direction. By depressing the operation pedal 28L, the left rear wheel 6 is driven at a predetermined speed, whereas the transmission to the right rear wheel 6 is cut off and the right rear wheel 6 is stopped by braking. The vehicle can travel, and furthermore, by depressing both the left and right operation pedals 28L, 28R together, the left and right rear wheels 6
, And stop running while stopping braking of the left and right rear wheels 6.

As shown in FIG. 2, the steering handle 11 is
A pitman arm 50 connected to the handle shaft 11A so as to swing left and right in the same direction as the turning direction of the steering handle 11, and a knuckle arm 51 connected to the left and right front wheels 5 so as to be integrally steerable and swingable. And the tie rods 5 on the left and right
The steering mechanism A is constituted by being interlocked and connected by 2. The left and right clutch / brake mechanisms 15L, 1R are operated so that the half-clutch state of the clutch / brake mechanisms 15L, 15R on the inside of the turn is displayed in conjunction with the operation of the steering mechanism A in the turning direction by a predetermined amount or more.
It is linked to 5R. In other words, the left and right clutches
The brake mechanisms 15L, 15R appear in a half-clutch state of the clutch / brake mechanisms 15L, 15R on the inside of the turning in conjunction with the operation of the steering mechanism A in the turning direction by a predetermined amount or more. Deceleration operating device B for forcibly decelerating the wheel 6 to operate the left and right rear wheels 6
It is linked to the steering mechanism A so as to function as.

The linkage structure will be described in detail with reference to FIG.
As shown in FIGS. 6 and 7, the inner wires of the left and right release wires 53 extend from the clutch / brake mechanism side of each rod 44 </ b> A of the left and right link mechanism 44 to the vicinity of the pitman arm 50 of the left and right tie rods 52. 53A is a spring 54 that is elastically deformed by the operation of the steering mechanism A in the turning direction between the rod 54A and the rod 44A.
It is hung in a state where it is interposed. One end of the outer wire 53B of the left and right release wires 53 is connected to a receiving member 55 provided at each extension end of an auxiliary arm 50A extending left and right from the swing fulcrum of the pitman arm 50. The ends are received by receiving members 55 provided at both ends of a support arm 56 disposed so as to be located between the operation pedals 28L, 28R and the right clutch / brake mechanism 15R on the right side of the body frame 7. It has become. The left and right springs 54 are elastically deformed by a value smaller than the urging force to the transmission state appearing side by the disc spring 42 generated when the clutch / brake mechanisms 15L, 15R show the non-transmission / non-braking state. Thus, it is possible to prevent the clutch / brake mechanisms 15L, 15R from switching to the non-transmission / non-braking state and the braking state due to the operation of the steering mechanism A in the turning direction.

That is, the left and right release wires 53, the spring 54, the auxiliary arm 50A of the pitman arm 50, the support arm 56, and the receiving member 55 allow the left and right clutch / brake mechanisms 15L and 15R (deceleration operating device B) to be steered. An interlocking differential operation mechanism C for interlocking connection with the mechanism A is configured. By configuring the interlocking differential operation mechanism C in this way, an operation of the steering mechanism A in the turning direction by a steering operation by a predetermined amount or more is performed. In conjunction with the clutch / brake mechanism 15L, 15R inside the turn
The half-clutch state (deceleration transmission state) can be reliably exhibited, and the rear wheel 6 inside the turning can be forcibly decelerated. The left and right linkage mechanisms 4
Each of the rods 44A in FIG. 4 is allowed to move forward with respect to the left and right operation pedals 28L and 28R so that the left and right clutch / brake mechanisms 15L and 15R can be interlocked with the steering mechanism A.

In short, from the above configuration, when turning, the left and right clutch / brake mechanisms 15L and 15R (reduction differential B) are interlocked with the steering operation of the steering handle 11 in the turning direction by a predetermined amount or more. The fore-rear inner wheel 6 is forcibly decelerated, and the left and right rear wheels 6 are differentially driven in a state where the inner-rear wheel 6 is driven at a lower driving speed than the outer rear wheel. Therefore, it is possible to perform turning with a small turning radius, and thereby, when reciprocating work traveling in a paddy field, it is possible to easily move to the start position of the next planting traveling train.
Also, during this turning, the rear wheel 6 inside the turning is gradually decelerated to drive the rear wheel 6 inside the turning little by little. Occurs when driving the rear wheel 6 is stopped.
Mud scraping by the rear wheel 6 inside the turning can be prevented, thereby damaging the field during the headland turning operation, or adversely affecting the headland operation operation after the reciprocating operation operation. In addition to avoiding such inconveniences, smooth headland turning can be performed even in a muddy or hard paddy field. Moreover,
During turning, it is not necessary to depress the operation pedals 28L, 28R inside the turn for operating the rear wheel 6 together with the operation of the steering handle 11 in the turning direction, which is advantageous in terms of operability. I have.

As shown in FIGS. 7 to 9, in the interlocking differential operating mechanism C, the support arm 56 is supported by the body frame 7 so as to be swingable in the front-rear direction, and the left end thereof is directed downward. A bent non-engaging portion 56A in a side view is provided. On the body frame 7,
An engaging member 57 having a concave portion 57A that engages with the non-engaging portion 56A of the support arm 56 from below is provided so as to be vertically swingable around the longitudinal axis. The engagement member 57 is
The downward swinging bias is applied by a spring 58 which is extended from the body frame 7 to the engaging member 57, and the switching lever 59 provided in the riding operation unit 1 </ b> A is operated to oppose the bias of the spring 58. It is linked to a switching lever 59 via a release wire 60 so as to ascend upward and oscillate. When the switching lever 59 is operated, a state in which the concave portion 57A is not engaged with the non-engaging portion 56A of the support arm 56 is determined. Joint 5
The posture is changed between a state of engaging with the lower end of 6A and a state of engaging with the upper end of non-engaging portion 56A. The recess 57A prevents the support arm 56 from swinging in the front-rear direction by engaging with the upper end of the non-engagement portion 56A of the support arm 56, and the non-engagement portion 56A
Is set to a size that allows the support arm 56 to swing in the front-rear direction within a predetermined range by engaging with the lower end of the support arm 56.

With the above configuration, the concave portion 57 of the engagement member 57
A is engaged with the upper end of the non-engaging portion 56A of the support arm 56 to prevent the swinging motion of the support arm 56, and the interlocking differential operation mechanism C causes the operation handle 11 to rotate in the turning direction. The left and right clutch / brake mechanisms 15L, 15 are sensitively interlocked with the steering operation exceeding a predetermined amount.
Since the half-clutch state of R appears, the deceleration rate of the turning inner rear wheel 6 with respect to the turning outer rear wheel 6 can be increased, and conversely, the recess 57A of the engagement member 57.
Is engaged with the lower end of the non-engaging portion 56A of the support arm 56 to allow the balance swinging of the support arm 56 within a predetermined range. In association with the steering operation of a predetermined amount or more, first, the support arm 56 swings the balance within an allowable predetermined range, and thereafter, the half-clutch state of the left and right clutch / brake mechanisms 15L, 15R is displayed. As a result, the deceleration rate of the turning inner rear wheel 6 with respect to the turning outer rear wheel 6 can be reduced, and the concave portion 57A of the engaging member 57 is provided with the non-engaging portion of the support arm 56. If not, the interlocking differential operation mechanism C only needs to swing the support arm 56 in balance with the steering operation of the steering handle 11 in the turning direction by a predetermined amount or more. As a result, since the half-clutch state of the left and right clutch / brake mechanisms 15L and 15R does not appear, the deceleration rate of the turning inner rear wheel 6 with respect to the turning outer rear wheel 6 can be made zero. It has become. That is, the supporting arm 5 of the interlocking differential operating mechanism C
6, the engagement member 57, the spring 58, the switching lever 59, and the release wire 60 reduce the speed of the rear wheel 6 inside the turning by the left and right clutch / brake mechanisms 15L and 15R with respect to the amount of operation of the steering mechanism A in the turning direction. A deceleration amount adjusting means D for changing and adjusting the amount, and an interlocking state switching means E for switching between a state in which the left and right clutch / brake mechanisms 15L and 15R and the steering mechanism A are interlocked and a state in which they are not interlocked, are constituted. This makes it possible to change the driving torque of the rear wheel 6 on the inside of the turn during turning in accordance with the condition of the running road surface, the turning form, etc., to the above-mentioned three states, and accordingly, it is possible to appropriately take into account the state of the running road surface and the like. Appearance of small turning traveling and appearance of normal turning traveling can be performed.

For example, when traveling on a road where traveling resistance is smaller than when traveling in paddy fields, the steering mechanism A
When the amount of deceleration of the inner rear wheel 6 by the left and right clutch / brake mechanisms 15L and 15R with respect to the amount of operation in the turning direction is reduced, the inner rear wheel 6 and the outer rear wheel 6 are turned.
The driving difference between the steering wheel A and the left and right clutch / brake mechanisms 15L and 15R with respect to the amount of operation of the steering mechanism A in the turning direction increases the amount of deceleration of the rear wheel 6 inside the turning. By increasing the drive difference between the inner rear wheel 6 and the outer rear wheel 6, the vehicle can perform a favorable small turning operation when traveling on the road. Conversely, when traveling in paddy fields where traveling resistance is greater than when traveling on roads, the inside of the turning by the left and right clutch / brake mechanisms 15L and 15R with respect to the amount of operation of the steering mechanism A in the turning direction is the same as during traveling on roads. When the amount of deceleration of the rear wheel 6 is increased, the driving torque of the rear wheel 6 on the inside of the turn becomes too small and becomes close to the drive stop state, so that the rear wheel 6 inside the turn scrapes off mud when turning the headland. The left and right clutch / brake mechanisms 15L, 15R with respect to the amount of operation of the steering mechanism A in the turning direction may not be able to be satisfactorily prevented from being performed.
Small turning that reduces the amount of deceleration of the rear wheel 6 inside the turning and increases the driving torque of the rear wheel 6 inside the turning, so that mud is not scraped off by the rear wheel 6 inside the turning during traveling in paddy fields. Traveling, that is, headland turning travel can be performed. In particular, since the driving torque of the rear wheel 6 inside the turning is increased, even in a muddy paddy field where the running resistance is considerably large, the mud is not scraped off by the rear wheel 6 inside the turning. The headland can be turned. Further, in a situation where it is not desired to make a small turning run such as a left turn or a right turn while traveling on the road, the left and right clutch / brake mechanisms 15L and 15R and the steering mechanism A are switched to a state where they are not linked. In conjunction with the operation of the steering mechanism A in the turning direction by a predetermined amount or more, a small turning traveling state in which the rear wheel 6 inside the turning is forcibly decelerated is prevented from appearing unnecessarily. Has become.

As shown in FIG. 10, the traveling body 1 has a planting clutch lever 6 disposed on the right side of the driver's seat 12.
1 (see FIG. 1), an electromagnetic control valve 62 for switching the flow state of hydraulic oil to the hydraulic cylinder 4 based on information from the first lever sensor S1 that detects the operation position of the operation position, and a transmission state to the seedling planting apparatus 2. A control device 65 for controlling the operation of the clutch motor 64 for switching the planting clutch 63 for switching the position is mounted. This control device 6
5 is a second lever sensor for detecting an operation position of an operation lever 66 (see FIG. 1) disposed at the lower right of the steering handle 11 when the planting clutch lever 61 is operated to the “automatic” position. The operation of the electromagnetic control valve 62 and the operation of the clutch motor 64 are controlled based on the information from S2. The control device 65 controls the operation of the operation lever 66 to operate the seedling planting device 2 using the second lever sensor S2 while the operation of the planting clutch lever 61 to the “automatic” position is detected by the first lever sensor S1. When the ascent command operation is detected, it is determined that headland turning is to be performed, and the electromagnetic cylinders 67 provided at the upper left and right ends of the cylindrical transmission case portion 25 in the rear axle case 22 are moved to the left and right. Clutch / brake mechanism 15
Arm 43 of shift fork 43 for operating L, 15R
By operating the left and right operation pedals 28L and 28R, the left and right clutch / brake mechanisms 15L and 15R are prevented from appearing in the braking state by operating the left and right operation pedals 28L and 28R.

That is, the headland turning detection means F for detecting the transition to the headland turning traveling is detected by the first lever sensor S1 and the second lever sensor S2. Based on the detection from the ground turning detection means F, a braking prevention mechanism G is configured to prevent the left and right clutch / brake mechanisms 15L, 15R from appearing in the braking state by operating the left and right operation pedals 28L, 28R. With this configuration, when turning the headland, the steering mechanism A and the left and right clutch / brake mechanisms 15 are turned.
Even when the left and right wheels L and 15R are not interlocked by the interlocking differential operation mechanism E, the half-clutch state of the left and right clutch / brake mechanisms 15L and 15R can be easily revealed by a simple operation of the left and right operation pedals 28L and 28R. In addition, when the steering mechanism A and the left and right clutch / brake mechanisms 15L and 15R are interlockingly connected by the interlocking differential operation mechanism E, the operator erroneously turns the left and right operation pedals 28L when turning the headland. , 28R can be prevented from being scraped off by the rear wheel 6 on the inside of the turn.

Although not shown, the left and right front wheels 5
During cornering, the differential gear mechanism operates to increase the speed of the front wheel 5 on the outside of the cornering to make a differential.

[Another Embodiment] The paddy field working vehicle may be a direct sowing machine other than the rice transplanter. In the left and right rear wheel transmission systems, for example, a gear type transmission mechanism, a belt type continuously variable transmission mechanism, or a hydrostatic type continuously variable transmission mechanism,
The deceleration differential device B may be configured by equipping the same. As the interlocking differential operation mechanism C, a configuration without the deceleration amount adjusting mechanism D (the deceleration differential device B and the steering mechanism A
(A configuration in which only switching between a state in which the steering mechanism A is interlocked and a state in which it is not interlocked is possible), or a configuration in which the interlocking state switching mechanism E is not provided (turning by the reduction gear differential B with respect to the amount of operation of the steering mechanism A in the turning direction) A configuration in which only the deceleration amount of the inner rear wheel 6 can be changed and adjusted) or a configuration in which both the deceleration amount adjusting mechanism D and the interlocking state switching mechanism E are not provided (only the deceleration differential device B and the steering mechanism A May be linked). Further, the interlocking differential operation mechanism C may have a configuration in which the spring 54 is not interposed between the left and right release wires 53 and the rod 44A. The deceleration differential device B and the steering mechanism A are not interlockedly connected by the interlocking differential operation mechanism C, and the left and right operation pedals 28
By depressing operation of L, 28R or other operation,
A configuration may be adopted in which the deceleration drive state of the rear wheel 6 inside the turning by the reduction gear differential B is revealed. The configuration of the deceleration amount adjusting mechanism D and the interlocking state switching mechanism E can be variously changed. For example, as the deceleration amount adjusting mechanism D, the concave portion 57A of the engaging member 57 is provided with the non-engaging portion 56A of the support arm 56.
A may be configured to be able to engage at any position within the range from the upper end to the lower end of A. The headland turning detection means F can be variously changed as long as it detects a shift to headland turning. Based on the detection from the headland turning detection means F, the braking prevention mechanism G prevents the left and right clutch / brake mechanisms 15L, 15R from appearing the braking state by operating the left and right operation pedals 28L, 28R. Thus, the appearance of the non-transmission / non-braking state may be prevented.

[Brief description of the drawings]

FIG. 1 is an overall side view of a riding rice transplanter.

FIG. 2 is a plan view of a riding type rice transplanter showing a linkage between a steering mechanism and a reduction differential mechanism.

FIG. 3 is an exploded sectional view of a rear axle case showing a configuration of a rear wheel transmission system.

FIG. 4 is a longitudinal rear view showing a configuration of a clutch / brake mechanism.

FIG. 5 is a longitudinal sectional side view showing a configuration of a clutch / brake mechanism.

FIG. 6 is a side view of a main part showing a linkage structure of the interlocking differential operation mechanism with the steering mechanism.

FIG. 7 is a plan view of a main part showing a configuration of a deceleration amount adjusting mechanism and an interlocking state switching mechanism of the interlocking differential operation mechanism.

FIG. 8 is a rear view of a main part showing a configuration of a deceleration amount adjusting mechanism and an interlocking state switching mechanism of the interlocking differential operation mechanism.

FIG. 9 is a side view of a main part showing a configuration of a deceleration amount adjusting mechanism and an interlocking state switching mechanism of the interlocking differential operation mechanism.

FIG. 10 is a control block diagram showing a configuration of a headland turning detection unit and a braking prevention mechanism.

[Explanation of symbols]

 6 Rear wheel 15L Clutch / brake mechanism 15R Clutch / brake mechanism 28L Operation pedal 28R Operation pedal 29 Clutch 30 Brake 54 Spring A Steering mechanism B Deceleration differential device C Interlocked differential operation mechanism D Deceleration amount adjusting means E Interlocking state switching means F Headland turning detection means G Braking prevention mechanism

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiyuki Kojima 64 Ishizukitamachi, Sakai City, Osaka Inside Kubota Sakai Works

Claims (7)

[Claims] 1. A steering operation structure for a paddy field work vehicle, comprising: a speed reduction differential device for forcibly decelerating and driving a rear wheel on the inside of a turn to make a difference between left and right rear wheels during turning. 2. The deceleration differential device according to claim 1, wherein the deceleration differential device is configured to forcibly decelerate and drive a rear wheel inside the turning in conjunction with an operation of a steering mechanism in a turning direction by a predetermined amount or more. The steering operation structure for a paddy field working vehicle according to claim 1, wherein the steering mechanism and the steering mechanism are interlockingly connected by an interlocking differential operation mechanism. 3. The interlocking differential operating mechanism is provided with deceleration amount adjusting means for changing and adjusting the amount of deceleration of the rear wheel inside the turning by the deceleration differential device with respect to the amount of operation of the steering mechanism in the turning direction. 3. A steering operation structure for a paddy field working vehicle according to claim 2. 4. The interlocking differential operating mechanism is provided with interlocking state switching means for switching between a state in which the deceleration differential device and the steering mechanism are interlocked and a state in which the steering mechanism is not interlocked. Steering operation structure of paddy field work vehicle. 5. The left and right clutch / brake comprising a friction type clutch and a brake mounted on each of the left and right rear wheel transmission systems, and the left and right clutches / brakes linked to the corresponding left and right operation pedals. The steering operation structure for a paddy field working vehicle according to any one of claims 1 to 4, wherein the steering operation structure is constituted by a mechanism so as to show a half-clutch state of the clutch / brake mechanism inside the turn during turning. 6. The steering operation structure for a paddy working vehicle according to claim 5, wherein the interlocking differential operation mechanism is provided with a spring that is elastically deformed by an operation of the steering mechanism in a turning direction. 7. A headland turning detecting means for detecting a transition to headland turning and a braking state of the clutch / brake mechanism by operating the operation pedal based on the detection from the headland turning detecting means. 7. The steering operation structure for a paddy field working vehicle according to claim 5, further comprising a braking prevention mechanism for preventing appearance.