JP2002104231A - Sulky type paddy field working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out an excellent traveling at a straight traveling during work traveling and to nimbly carry out a direction change of a body near a ridge between rice fields in a sulky type paddy field working machine in which a working device is ascendably/descendably connected to a rear part of a traveling machine body provided with a power steering device for steering a front wheel. SOLUTION: The sulky type paddy field working machine is provided with a side clutch automatic operation mechanism for disconnection-operating a side clutch of a rear wheel 2 at a turning inner side interlocked by steering a front wheel 1 to a set angle or more; and a power steering function switch means for switching an assist ability of the power steering device PS to a high/low degree. If a steering angle of the front wheel 1 is less than the set angle, it is judged that the assist ability of the power steering device PS is at a low state. When the side clutch automatic operation mechanism 106 is operated, the assist ability of the power steering device PS is switched to a high state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a riding type paddy working machine such as a riding type rice transplanter and a riding type direct sowing machine, and more particularly to a traveling type paddy working machine in which steering power is transmitted to the steerable left and right front wheels and to a non-steerable front wheel. While transmitting to the left and right rear wheels, and at the rear of the traveling body equipped with a power steering device that controls the steering of the front wheels,
The present invention relates to a riding type paddy working machine in which a working device is connected to move up and down.

[0002]

2. Description of the Related Art In a riding type rice transplanter, which is a representative of the riding type paddy working machine, when the planting travel of one stroke is completed and the ridge is reached, the body is turned U-turn to shift to the next planting stroke. In other words, a so-called reciprocating planting is a standard planting form, and a power steering device is used to steer the front wheels so that turning around a ridge can be performed lightly. In this case, when changing the direction of the aircraft on the ridge in the paddy field, the load to steer the front wheel is considerably increased because the front wheel scrapes a lot of mud, and the assist capacity of the power steering device is set accordingly. Is done.

[0003]

As described above, if the assisting capability of the power steering device is set in accordance with the front wheel steering load at the ridge, it is possible to easily change the body direction at the ridge. On the other hand, on the other hand, the steering wheel becomes too light at the time of planting traveling for performing straight planting, and the front wheels tend to fluctuate and the straightness tends to be reduced.

[0004] The present invention has been made in view of such circumstances, and can perform traveling with excellent straightness during work traveling, and can easily change the direction of the aircraft at the ridge. The main purpose is to do so.

[0005]

Means for Solving the Problems [Structure, operation and effect of the invention according to claim 1]

According to a first aspect of the present invention, there is provided a power steering apparatus configured to transmit the shifted power to steerable left and right front wheels and to a non-steerable rear wheel and to steer the front wheels. In the riding paddy working machine with a working device connected to the rear of the traveling machine that can move up and down, side clutches are provided for each of the left and right rear wheels, and it is linked to that the front wheel is steered beyond a set angle A side clutch automatic operation mechanism for disengaging the side clutch on the inside of the turn, and power steering function switching means for switching the power steering device on and off or for switching the assist capability to a high or low level. If the steering angle of the front wheels is less than the set angle, the power steering device is turned off or the assist capability is set to a low state, The power steering function switching means is configured to switch the power steering device to an on state or a state of high assist capability when the side clutch automatic operation mechanism is operated by being steered at the set angle or more. It is characterized by the following.

(Operation) According to the above configuration, the power steering device does not function or the assisting ability is low during work traveling in a field where the front wheel steering angle is small, so that the steering wheel is appropriately heavy. The front wheels do not fluctuate. Also, when approaching the ridge, simply steering the front wheel more than the set angle will automatically disengage the side clutch of the rear wheel inside the turning, allowing the rear wheel dragging inside the turning. Accordingly, the aircraft makes a large small turn by three-wheel drive with the left and right front wheels and the rear wheel on the outside of the turn. Moreover, at this time, the power steering device is switched from a non-working state to a working state, or from a low assist state to a high assist state, so that the front wheels can be steered large and quickly with a light steering operation. it can.

(Effects) Therefore, according to the first aspect of the present invention, it is possible to perform traveling with excellent straightness at the time of work traveling, and at the same time, it is possible to lightly change the direction of the aircraft at the edge of the ridge. It is possible to obtain a riding paddy working machine excellent in performance.

[Structure, operation and effect of the invention according to claim 2]

(Structure) According to a second aspect of the present invention, there is provided a power steering apparatus configured to transmit the shifted power to the steerable left and right front wheels and to the unsteerable rear wheels, and to steer the front wheels. In a riding type paddy working machine in which a working device is vertically connected to a rear part of a traveling machine body provided with side clutches for left and right rear wheels, respectively, the front wheels are steered at a first set angle or more. Interlocking with this, a side clutch automatic operation mechanism for disengaging the side clutch on the inside of the turn, and a power steering function switching means for switching the power steering device on and off or for switching the assist ability to high and low. If the steering angle of the front wheels is smaller than a second set angle smaller than the first set angle, the power steering device is turned off, or The power steering function switching so that the power steering device is turned on or the power assist device is switched to a high assist capability state when the front wheels are steered by the second set angle or more when the assist capability is low. It is characterized by comprising means.

(Operation) According to the above configuration, the power steering device does not function or the assisting ability is low during work traveling in a field where the front wheel steering angle is small, so that the steering wheel is appropriately heavy. The front wheels do not fluctuate. Also, at the edge of the furrow, the front wheel is steered more than the second set angle to switch from a state in which the power steering device does not work to a state in which the power steering device works, or from a state in which the assist ability is low to a state in which the assist ability is high. Switch,
The front wheels can be steered larger and faster with a light handle operation. Then, when the front wheels steer more than the first set angle, the side clutch of the rear wheels on the inside of the turning is automatically disengaged, and the aircraft is moved to the left and right front wheels in a state where the rear wheels on the inside of the turning are allowed to drag. The vehicle turns greatly and slightly by three-wheel drive with the rear wheel on the outside of the turn.

(Effects) Therefore, according to the second aspect of the present invention, the steering wheel becomes lighter by the time the side clutch automatic operation mechanism is operated, and the front wheels can be steered up to the first set angle lightly. , Similar to the first aspect of the invention,
During work traveling, traveling with excellent straightness can be performed, and at the time of turning around the ridge, the vehicle can be turned more easily, and operability can be further improved.

[Structure, operation and effect of the invention according to claim 3]

(Structure) According to a third aspect of the present invention, there is provided a power steering apparatus configured to transmit the shifted power to the steerable left and right front wheels and to the unsteerable rear wheels and to steer the front wheels. In the riding paddy working machine with a working device connected to the rear of the traveling machine that can move up and down, side clutches are provided for each of the left and right rear wheels, and it is linked to that the front wheel is steered beyond a set angle A side clutch automatic operation mechanism for disengaging the side clutch on the inside of the turn, a power steering function switching means for switching the power steering device on and off, or switching the assist capability to a high or low level, An operating tool for giving a forced ascending command to forcibly raise the device to a predetermined ascending position, and when the working device is in a working height range, The power steering device is turned off, or the assist capability is low, and when a forced ascending command is given by the operating tool, the power steering device is turned on or the assist capability is switched to a high state. The power steering function switching means is constituted.

(Operation) According to the above configuration, the power steering device does not function or the assisting ability is low during work traveling in a field where the front wheel steering angle is small, so that the steering wheel is appropriately heavy. The front wheels do not fluctuate. In addition, when approaching the ridge, a forcible ascent command is issued prior to the turning of the aircraft, and the working device is raised from the rice field. Issuing this compulsory ascent command causes the power steering device to switch from a non-working state to a working state,
Alternatively, since the assist ability is switched from a low state to a high state, the front wheels can be steered large and quickly with a light steering operation. The airframe is automatically disengaged, and the airframe makes a large small turn by three-wheel drive of the left and right front wheels and the rear wheel on the outside of the turn while allowing the rear wheel on the inside of the turn to drag and rotate.

(Effects) Therefore, according to the third aspect of the present invention, the steering wheel is lightened based on the lifting operation of the working device performed prior to the turning of the body at the ridge, and the front wheel steering up to the set angle is lightened. As in the case of the first aspect of the present invention, it is possible to perform traveling with excellent straightness at the time of work traveling, and it is possible to perform the turning of the aircraft at the ridge more lightly, thereby improving operability. Can be further improved.

[Structure, operation and effect of the invention according to claim 4]

(Structure) According to a fourth aspect of the present invention, there is provided a power steering device configured to transmit the shifted power to the steerable left and right front wheels and to the unsteerable rear wheels and to steer the front wheels. A power steering function switching means for switching the power steering device on or off, or for switching the assisting ability between high and low, in a riding type paddy working machine in which a working device is connected to a rear portion of a traveling body provided so as to be able to move up and down. Means for detecting a running load, and when the detected running load is less than a set value, the power steering device is turned off or the assist ability is set to a low state, and the detected running load is set to a set value. Is exceeded, the power steering device is turned on, or the power steering device is switched to a high assist capability state. It is characterized in that function switching means is constituted.

(Operation) According to the above configuration, in work traveling in a field where the front wheel steering angle is small, mud is less likely to be scratched on the side surfaces of the front wheels, and the overall traveling load is relatively small. Therefore, the power steering device does not function or the assist ability is low, the steering wheel is moderately heavy, and the front wheels do not wobble. Further, when the front wheels are steered toward the ridge, mud scraping on the side surfaces of the front wheels increases, and the running load increases. When this increase in load is detected, the power steering device is switched from a non-working state to a working state, or from a low assist state to a high assist state, and the front wheels are made larger and quicker with a light steering operation. Can be steered. In this case, if the mud has a high viscosity, the steering wheel becomes lighter even if the front wheel steering angle is relatively small. Conversely, in a paddy field where the mud is less viscous and the front wheel can be easily steered, the front wheel steering is performed. The steering wheel becomes lighter only when the heading angle increases to some extent.

(Effects) Therefore, according to the invention of claim 4, when the running load becomes large and it becomes difficult to perform front wheel steering, the steering automatically becomes lighter, and the vehicle travels with excellent straightness during work traveling. This makes it easier to change the direction of the aircraft on the ridge, and can execute power assist that can respond to paddy field conditions such as soil quality, which is highly practical and convenient. Becomes

[0021]

1 and 2 show a riding type rice transplanter of a five-row type as an example of a paddy field working machine. This riding type rice transplanter is a riding type traveling machine body 3 having a pair of left and right steerable front wheels 1 and a pair of unsteerable left and right rear wheels 2.
At the rear, a five-row planting seedling planting device 4 is connected via a four-link mechanism 5 driven by a lifting cylinder 6 so as to be able to move up and down freely, and a 5-row planting fertilizer 7 is provided at the rear of the body. It has a structure.

A transmission case 9 having a front axle case 9a for supporting the front wheel 1 is fixedly connected to a front portion of a body frame 8 of the traveling body 3, and a rear wheel is provided at a rear portion of the body frame 8. A rear transmission case 10 that supports the shaft 2 is supported in a freely rolling manner. In addition, an engine 11 having a lateral output shaft 11a is mounted via a vibration-isolating rubber 12 at a position near the front of the transmission case 9, and a boarding operation unit 13 is provided in a state located behind the engine 11. ing. A steering handlebar 14 for steering the front wheels 1, a driver seat 1,
5, an operation step 24 and the like are provided.

The seedling planting apparatus 4 mounts five seedlings, and reciprocates in a set stroke in the left-right direction, and cuts out seedlings one by one from the lower end of the seedling stand 16. 5 sets of rotary planting mechanism 17 for planting in the field
The machine is provided with three leveling floats 18 for leveling the planting locations, etc., and a spare seedling rest 49 for mounting and storing spare seedlings for replenishing the seedling rest 16 in a plurality of stages is provided at the front of the body. It is deployed on the left and right of.

The fertilizer application device 7 is mounted on the traveling body 3 between the driver's seat 15 and the seedling planting device 4.
A fertilizer hopper 19 for storing powdered and granular fertilizer, and a feeding mechanism 2 for feeding the fertilizer in the fertilizer hopper 19 by a set amount.
0, an electric fan 23 that pneumatically conveys the fed fertilizer through a supply hose 22 to a groove generator 21 provided on the leveling float 18 of the seedling planting device 4.

As shown in FIGS. 3 and 4, on the left side of the transmission case 9, an output shaft 11 of the engine 11 is provided.
a main transmission 41 comprising a hydrostatic continuously variable transmission (HST) having a lateral input shaft 41a interlocked with the transmission shaft a via a belt transmission device 40, and transmits the output of the main transmission 41 into the transmission case 9 by a lateral shaft. And the input shaft 4
1a and the output shaft 41b are connected in a state where they are arranged in front and rear.

The belt transmission 40 includes an engine 11
The transmission belt 40c is wound around an output pulley 40a attached to the output shaft 11a of the main transmission 41 and an input pulley 40b attached to the input shaft 41a of the main transmission 41.
A tension pulley 40d for applying tension to 0b is provided.

The input shaft 41a of the main transmission 41 extends rightward through the front of the transmission case 9. A main speed change lever 46 for operating the main speed change device 41 is disposed on the left side of the steering handle 14, and the forward speed can be changed by a swing operation of the main speed change lever 46 from neutral to forward. In addition, the reverse speed can be changed by a swing operation from neutral to backward.

As shown in FIG. 4, an input shaft 4 of the main transmission 41 is provided on a right side surface of the transmission case 9.
A hydraulic pump 42 driven by the extension end of the steering wheel 14 is connected to a hydraulic pump 42 which is linked to a handle shaft 14a of the steering handle 14, as shown in FIGS. A torque generator 43 constituting the power steering device PS and a control valve 44 for a working device lifting / lowering operation for controlling the lifting / lowering cylinder 6 are attached.

As shown in FIGS. 5 and 6, the transmission case 9 has a main clutch 50 for interrupting the transmission of the output from the main transmission 41, and a two-stage high and low output. Transmission 51, and a differential mechanism 52 for transmitting the output from the sub transmission 51 to the left and right front wheels 1, and only the forward power of the power branched from the traveling transmission system is provided. A one-way clutch 53 for transmitting to the seedling planting device 4, a planting transmission mechanism 54 for changing the power between the plants, a planting clutch 55 for intermittently transmitting power to the seedling planting device 4, and the like. Equipped.

The main clutch 50 is of a multi-plate type, and a drive-side boss member 58 can rotate integrally with an input shaft 57 connected to an output shaft 41b of the main transmission 41 via a coupling 56. , And a driven drum 60 that covers the drive-side boss member 58 is rotatably connected and supported integrally with a clutch output shaft 59 loosely mounted on the input shaft 57 so as to be shiftable. By shifting the driven drum 60 with respect to the driving boss member 58 and pressing or releasing the friction plates 61 interposed between the driving boss member 58 and the driven drum 60, the driving boss is shifted. The frictional transmission of power from the member 58 to the driven side drum 60 is interrupted, and the clutch output shaft 59 and the driven side drum 60
Is always urged by the spring 62 in the friction plate pressing direction (the clutch engagement direction).

The main clutch 50 can be turned on and off only by pedal operation. That is, the body stopping pedal 25 provided at the right foot of the step 24 in the boarding operation unit 13 penetrates the upper surface of the transmission case 9 so as to be rotatable around a vertical axis P orthogonal to the input shaft 57. The pedal shaft 2 is connected to the mounted clutch operation shaft 63 in an interlocking manner and rotates integrally with the pedal 25.
6, a rotating arm 27 is attached.
7 and a passive arm 63a provided on the outer part of the case of the clutch operation shaft 63 are interlockingly connected by a rod 28, and the clutch operation shaft 63 is moved in accordance with the depression operation and the depression release operation of the pedal 25. It is designed to be turned forward and backward.

An eccentric cam 63b having a semicircular cross section formed by cutting off a part of the peripheral surface thereof is formed at the tip of the clutch operating shaft 63 in the case.
b faces the end face of the clutch output shaft 59.
In a normal state where the pedal 25 is not depressed, the eccentric cam 63b is connected to the clutch output shaft 59 as shown in FIG.
Of the main clutch 50, thereby bringing the main clutch 50 into the "engaged" state. When the pedal 25 is depressed, the edge of the eccentric cam 63b is displaced and pressed against the end face of the clutch output shaft 59, and the clutch output shaft 59 is moved against the bias by the spring 62, and the driven drum 60 Is displaced rightward in the figure, whereby the main clutch 50 is switched to the "disengaged" state. In this clutch disengaged state, the eccentric cam 63b
The friction between the edge portion of the clutch output shaft 59 and the end face of the clutch output shaft 59 gives resistance to the rotation of the clutch output shaft 59, and prevents the clutch output shaft 59 from rotating together with the input shaft 57.

The sub-transmission 51 is of a gear shift type. A high-speed large-diameter transmission gear 65 and a low-speed small-diameter transmission gear 66 are integrally rotated on a transmission input shaft 64. The high-speed position, in which the small-diameter gear portion 68 meshes and interlocks with the large-diameter transmission gear 65, and the low-speed position, in which the large-diameter gear portion 69 meshes and interlocks with the small-diameter transmission gear 66, are mounted on the transmission output shaft 67. A shift gear 70 that can freely shift to a neutral position where the gears do not engage with each other is mounted so as to rotate integrally. A small-diameter output gear 71 that meshes with the large-diameter transmission gear 65 and transmits the power in a decelerated manner is mounted on the clutch output shaft 59 so as to rotate integrally therewith.
Is linked to deceleration. A sub-transmission lever 47 for operating the sub-transmission 51 is arranged on the left side of the driver's seat 15.

The differential mechanism 52 is configured to be differentially lockable. That is, a shift member 74 is attached to one of the differential shafts 72 extending left and right so as to be rotatable integrally with the differential shaft 72 and shiftable. As shown in FIG. The state in which the shift member 74 is separated from the state 73 is a normal differential lock release state, and the shift member 74 is shifted rightward in the drawing and meshes with the end face of the differential case 73 to provide a differential lock state. The differential lock operation means for switching the differential mechanism 52 between the differential lock state and the differential lock release state includes a spring (not shown) that urges the shift member 74 to the differential lock release position and a riding operation unit 13.
The differential lock pedal 48 and the shift member 74, which are provided at the left rear portion of the foot of the vehicle, are linked to each other,
By releasing the foot from the differential lock pedal 48 during normal traveling, the differential lock release state is maintained, the aircraft is taken in and out of the field, and the aircraft is loaded and unloaded on the carrier of the transport vehicle,
In such a case, the differential lock pedal 48 is depressed with the heel of the left foot to provide a differential lock state, and the left and right front wheels 1 can be driven at a constant speed.

The differential case 73 of the differential mechanism 52
An input gear 76 meshed with a shift output gear 75 spline-connected to the shift output shaft 67, and an output gear 79 is mounted on a gear 78 integrally formed with the main transmission shaft 77 for transmission to the rear wheel 2. I have.

The one-way clutch 53 uses the transmission input shaft 64 as a branch point from the traveling transmission system to the planting transmission system.
It is provided so that only the forward rotation of the rotation of the speed change input shaft 64 is transmitted to the planting transmission system.

The planting transmission mechanism 54 is mounted on the transmission output shaft 67 so as to be freely rotatable only relative to the transmission output shaft 67, and has a diameter relative to a cylindrical shaft 82 which is interlocked with an output gear 80 of the one-way clutch 53 via a gear 81. Drive gears 83 having different driving gears
Are mounted so as to rotate integrally with each other, and are linked to the planting clutch 55 via bevel gears 84 and 85, so that the speed change output shaft 8 is planted.
6, a group of driven gears 87 which are always engaged with and linked to each of the drive gears 83 are rotatably mounted relative to each other, and the driven gears 87 are engaged with engagement recesses 88 formed in the center holes of the driven gears 87 so that the driven gears 87 are engaged. A transmission ball 89 interlockingly connected to the planted transmission output shaft 86 is provided so as to rotate integrally with the planted transmission output shaft 86, and an operating shaft 90 is provided for selectively engaging the transmission ball 89 with the engagement recess 88. It is a structure that was given. That is, by alternately linking the driven gear 87 to the planted transmission output shaft 86, the driven gear 87 used for transmission is changed, and a plurality of gears (in the example, six gears) are shifted. Have been.

The rear transmission case 10 for driving rear wheels is shown in FIG.
As shown in FIG. 9, a horizontal transmission case portion 10A is supported by the body frame 8 so as to be freely rotatable within a predetermined range around a longitudinal axis X, and a speed reduction case portion 10B connected to both left and right ends thereof. Have been. Inside the horizontal transmission case portion 10A, there is provided a horizontal transmission shaft 93 for distributing the power from the main transmission shaft 77 extending rearward from the transmission case 8 to the left and right, and the horizontal transmission shaft 93 and the main transmission shaft 77 are provided. Are linked to each other via bevel gears 91 and 92. Further, each deceleration case portion 10B has an axle 2A for supporting the rear wheel 2 and the lateral transmission shaft 93.
And a reduction gear mechanism 94 for reducing the speed of the axle 2A.

A transmission system to the rear wheel 2, more specifically, a friction type for separately transmitting the transmission to each rear wheel 2 is provided between both ends of the lateral transmission shaft 93 and each reduction gear mechanism 94. Side clutch 96 is interposed. These side clutches 96 are provided with a boss member 96A that is spline-fitted to the lateral transmission shaft 93, is integrally rotated, and is movable in the axial direction, and a driven drum 96B that is interlocked with the reduction gear mechanism 94. A plurality of friction plates 96C, which are pressed against each other by the outward movement of the fuselage to engage in friction (clutch engagement) and release the frictional engagement (clutch disengagement) by moving the boss member 96A inwardly to the fuselage, are connected to the boss member. A clutch spring 96 </ b> D that is distributed and mounted on the driven drum 96 </ b> A and the driven drum 96 </ b> B and urges the boss member 96 </ b> A toward the clutch engagement side is externally mounted on the lateral transmission shaft 93.

The reduction gear mechanism 94 is provided on the outer side of the driven drum 96B of the side clutch 96 and has a small diameter first gear G1 which rotates integrally with the driven drum 96B.
A large-diameter second gear G2 meshing with the second gear G2, a small-diameter wide third gear G3 coaxial with the second gear G2 and integrally rotating therewith;
The large-diameter and wide fourth gear G4 connected to the axle 2A is configured to reduce the speed in two stages. A gear pair of the third gear G3 and the fourth gear G4 is provided inside the body and a side gear is provided. The lower portion of the clutch 96 is suppressed from widening the speed reduction case 95 laterally outward.

As shown in FIG. 9, a brake 30 for stopping the vehicle is provided between the right deceleration case portion 10B and the boss member 96A. This brake 30
By pressing the friction plate 31 fitted to the outer periphery of the boss member 96A to the outside of the spline and the friction plate 32 engaged with the inner periphery of the deceleration case portion 10B and stopped from rotating, the boss member 96 is pressed.
A and the transverse transmission shaft 93 that rotates integrally therewith are configured to be braked, and the cup-shaped operation member 33 loosely fitted to the boss member 96A is laterally outward (rightward in FIG. 9).
, The friction plates 31 and 32 are pressed against each other.

The brake 30 for stopping the machine is operated by a brake operation shaft 34 which is rotatably mounted on the upper surface of the deceleration case 10B around the longitudinal axis P1. In other words, the shift fork 35 is mounted on the portion of the brake operation shaft 34 that protrudes into the case, and the shift fork 35 is provided to face the end surface of the operation member 33. The boss member 96A can be braked by shifting the operation member 33 via the shift fork 35.

Then, as shown in FIG. 7, an operation arm 34a provided on the outside of the case of the brake operation shaft 34 is provided.
Is interlocked with the pedal 25 for stopping the machine via a link rod 36. With the depression of the pedal 25, the link rod 36 is pulled forward and the brake 30 is braked, and the pedal 25 is depressed. Is released to return to the original posture, the brake of the brake 30 is released. Here, this brake 30
As described above, the pedal 25 is also linked to the main clutch 50, so that the pedal 25 functions as a main clutch / brake pedal. In addition, a lock fitting 120 for locking and locking the pedal 25 depressed to the braking operation position at that position is swingably provided near the pedal 25 and is urged to swing in the unlocking direction to be provided. The brake 30 is used as a parking brake by the pedal lock using the lock fitting 120.

The linkage rod 36 is provided with a turn buckle 36a.
By adjusting the expansion and contraction to “a”, the operation timing of the brake 30 with respect to the main clutch 50 can be adjusted.

The operation structure of the side clutch 96 is configured as follows. In other words, the clutch operating sleeve 102 is disposed on the lateral transmission shaft 93 with the end face of the boss member 96A abutted through the thrust collar 103.
Is freely slidably fitted, and the reduction case 1
A clutch operation shaft 104 is rotatably mounted on the upper surface of the clutch operation shaft 104 so as to be rotatable around a vertical axis P2. The side clutch 9 is disposed to be opposed, and is rotated by the rotation operation of the clutch operation shaft 104.
6 is turned on and off.

The left and right side clutches 96
Only the inside of the turning operation is automatically turned off based on the body steering operation to provide a body steering function.
Is configured as follows. That is, as shown in FIGS. 7 and 8, the pitman arm 111 oscillatingly driven about the vertical axis Z by the torque generator 43 constituting the power steering device PS and the knuckle arm 118 of each front wheel 1 are connected to the tie rod 119. The steering link mechanism 110 is constructed by interlocking the operation bracket 111a, and the operating bracket 111a connected to the pitman arm 111 and the vertical axis Y
A relay arm 113 swingably disposed around the relay arm 113 is interlocked and connected by a push / pull rod 112, and the left and right ends of a balance arm 115 connected to the upper end of a fulcrum shaft 114 of the relay arm 113 and the case of the left and right clutch operation shafts 104. The operation arm 104a connected to the outer protrusion is
6 are interlockingly connected.

Further, a push-pull rod 112 formed on an operation fitting 111a connected to the pitman arm 111 is provided.
Is formed as an elongated hole along the swinging direction of the operating bracket 111a, and the pitman arm 111 is swung only when the pitman arm 111 swings from a straight posture to a predetermined angle (for example, 30 °) or more. The length of the linking hole 117 is set so that the swing of 111 is transmitted to the push-pull rod 112 but not the swing smaller than the set angle.

Therefore, when the left and right front wheels 1 are steered more than a set angle in order to turn the body largely, the swing of the pitman arm 111 is transmitted to the balance arm 115 via the relay arm 113, and the pulling operation is performed forward. Only one of the side clutches 96 linked to the rod 116 is disengaged. In other words, the side clutch 9 inside the turn
6 is turned off, the fuselage is turned by the three-wheel drive of the left and right front wheels and the rear wheel 2 on the outside of the turn, and the rear inner wheel 2 in the idle state follows the ground with the turning movement of the body. The body is turned without unduly damaging the field with the rear wheel 2 inside the turn.

When the pedal 25 is depressed while the main speed change lever 46 is operated in the forward high speed range, the main speed change lever 46 is forcibly decelerated. Is shown in FIG.
That is, the main speed change lever 46 is attached to the detent plate 121 rotatably supported around the lateral fulcrum a by the front-rear fulcrum b.
It is mounted so as to be able to oscillate around and has a horizontal fulcrum a
It is operably supported from the forward area F to the reverse area R with the neutral N interposed therebetween by swinging around the periphery. The lower end of the operating rod 122 extending downward from the detent plate 121 is connected to the main transmission 4 via a link 123 rotatable around a fulcrum c and a push / pull rod 124.
The main transmission 41 is continuously variablely operated by the main transmission lever 46 by being interlocked with the first transmission operation shaft 125. Note that the detent roller 126 is elastically engaged with the outer peripheral waveform portion of the detent plate 121 so that the shift position can be held at a small pitch.

Also, behind the main transmission operating section,
A restraint link 127 is provided around the fulcrum d, which can swing back and forth and is biased in a clockwise direction. A part of the restraint link 127 is opposed to a contact pin 128 provided on the link 123. ing. Further, a contact bolt 129 is provided rearward at the lower end of the restraining link 127, and a front end 28 a of the rod 28 operatively connected to the operating arm 63 a of the main clutch 50 is attached rearward to the contact bolt 129. And the pedal 2
When the main clutch 50 is disengaged by stepping on the rod 5, the rod 28 moves forward. At this time, if the main shift lever 46 is operated to the forward high-speed position, the rod 28
Pushes the contact bolt 129 forward, whereby the restraining link 127 is rotated clockwise in FIG.
8, the link 123 is rotated counterclockwise, and the operation rod 122 is pulled down, so that the main transmission lever 4
6 is forcibly operated to the rear, that is, to the low speed side.
In this case, when the pedal 25 is depressed to the maximum, the main shift lever 46 that has been forcibly decelerated is set to return to the forward low-speed position close to the neutral N.

In the riding type rice transplanter configured as described above, in the present invention, the following configuration is added in order to improve the maneuverability of the fuselage.

(First Example)

As shown in FIG. 12, a torque generator 43 is provided in the hydraulic circuit of the power steering device PS.
A variable relief device 130 for changing the hydraulic pressure supplied to the vehicle is interposed. The variable relief device 130 includes two types of relief valves 131 and 132 having different relief operating pressures.
And an electromagnetic switching valve 133 for selecting either one of them. Usually, as shown in the figure, the relief valve 131 on the low pressure side is selected to keep the circuit pressure low, and the assisting capability of the power steering device PS Is kept low. Further, when the electromagnetic switching valve 133 is energized and the high-pressure side relief valve 132 is selected, the circuit pressure is increased and the assist capability of the power steering device PS is increased. At the pivot point Z of the pitman arm 111, a potentiometer 134 for detecting a steering angle of the front wheel 1 is provided, and is connected to a control device 135 for controlling the operation of the electromagnetic switching valve 133. Is controlled as follows according to the steering angle of the vehicle.

That is, when the steering angle of the front wheel 1 is smaller than the set angle for activating the side clutch automatic operation mechanism 106, the electromagnetic switching valve 133 is not energized, and the circuit pressure of the power steering device PS is kept low. . Accordingly, the steering handle 14 is slightly heavy during planting traveling without steering too much, and traveling with excellent straightness can be performed without the front wheel 1 fluctuating.

After the planting run of one stroke is completed and the vehicle reaches the edge of the ridge, when the aircraft is turned large U-turns, the front wheel 1
When the steering angle becomes larger than the set angle and the side clutch automatic operation mechanism 106 is activated, the electromagnetic switching valve 133 is energized and switched, and the circuit pressure of the power steering device PS increases. Therefore, the steering handlebar 14 becomes lighter in a small turning around the ridge where the front wheel 1 is largely steered, and the traveling body 3 can be turned lightly.

A steering mode selection switch 136 is connected to the control device 135. By operating the switch 136, the electromagnetic switching valve 133 is always de-energized regardless of the steering angle of the front wheels 1. The "low assist mode" L in which the circuit pressure of the power steering device PS is kept low while maintaining the electromagnetic switching valve 133 regardless of the steering angle of the front wheels 1,
The "high assist mode" H in which the circuit pressure of the power steering device PS is increased, and the "auto assist mode" in which the circuit pressure of the power steering device PS is automatically switched based on the steering angle of the front wheels 1 as described above. "A" can be selected.

(Second example)

In the configuration shown in FIG. 12, assuming that the steering angle of the front wheel 1 at which the automatic operation of the side clutch 106 is started is the first set angle θ1, a second set angle θ2 smaller than the first set angle θ1 is set in advance. If the steering angle of the front wheel 1 is smaller than the second set angle θ2 in the state where the “auto assist mode” A is selected, the above-described low assist state is maintained, and the front wheel 1 The control device is set so that when the steering is performed at the set angle θ2 or more, the high assist state is set.

According to this configuration, in straight planting traveling, the wobble of the front wheel 1 can be reduced, and even when the steering is relatively large in a deformed field or the like, the steering can be performed lightly. be able to.

(Third example)

In this example, the variable relief device 130
Is controlled based on the raising / lowering operation of the seedling planting apparatus 4.
That is, as shown in FIG. 2, a neutral return type priority lifting lever (an example of an operating tool) 140 is provided on the right lateral side of the steering handle 14, and as shown in FIG. An ascending switch sw1 and a descending switch sw2 for detecting the operation of the elevating lever 140 are connected to the control device 135, and the elevating control valve 44 is configured as an electromagnetic switching valve and connected to the control device 135. .

When the raising switch sw1 is operated by the priority raising / lowering lever 140, the control valve 44 is switched to the raising position, and the seedling planting device 4 at the working height is raised to the upper limit (set height). The electric motor 141 for turning on and off the planting clutch is operated, and the driving of the seedling planting device 4 is stopped. When the lowering switch sw2 is operated by the priority raising / lowering lever 140 while the seedling planting device 4 is at the upper limit, the control valve 44 is switched to the lowering side, and the seedling planting device 4 is lowered to the working height. Further, when the lowering switch sw2 is operated again by the priority raising / lowering lever 140, the drive of the seedling planting apparatus 4 is restarted.

Here, in the present invention, during the planting operation in which the seedling planting device 4 is traveling at the working height, the electromagnetic switching valve 133 of the variable relief device 130 is not energized.
The circuit pressure of the power steering device PS is kept low. Therefore, during the planting operation, the steering handle 14 is in a slightly heavy state, and traveling with excellent straightness can be performed without the front wheel 1 fluctuating. Also, priority lifting lever 1
When the lifting switch sw1 is operated by the switch 40, the electromagnetic switching valve 133 is energized and switched, so that the circuit pressure of the power steering device PS increases. Therefore, the steering handlebar 14 becomes lighter in the small turning of the ridge when the seedling planting apparatus 4 is raised by operating the priority raising / lowering lever 140 to steer the aircraft largely, and the traveling machine 3 can be turned slightly.

In this example, as the operating tool for raising and lowering the seedling planting device 4, in addition to using the priority raising and lowering lever 140 for operating the raising switch sw1 and lowering switch sw2 as described above, the raising switch sw1 and the raising switch sw1 are used. It is also possible to use a switch lever or a switch button for directly operating the down switch sw2.

(Fourth example)

As shown in FIG. 14, in this example, the transverse transmission shaft 93 for distributing power to the left and right rear wheels 2 is provided with a torque sensor 145 as running load detecting means, and based on the detected running load. The variable relief device 130
Is configured to be controlled. That is, if the detected traveling load is less than the set value, the low assist state described above is maintained, and if the detected traveling load is equal to or greater than the set value, the high assist state is established. 135 is set.

According to this configuration, while the traveling load is small, the state where the assisting ability of the power steering device PS is low is maintained, and the front wheels 1 can be steered with excellent straight-moving performance in which the front wheels 1 are less likely to wander. When the running load increases, the state in which the assisting ability of the power steering device PS is high is maintained, and light steering of the steering wheel operation becomes possible.

In each of the above-described examples, the case where the capability of the power steering device PS is switched between high and low is shown. However, the power steering device PS can be turned on and off so that the power steering device PS can be turned on and off when working in a field. The power steering device PS can be turned on when the PS is turned off and the conditions for judging the turn on the ridge are met.

[Brief description of the drawings]

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

FIG. 2 is an overall plan view of the rice transplanter.

FIG. 3 is a side view of a front part of the aircraft.

FIG. 4 is a plan view of a front part of the fuselage.

FIG. 5 is a sectional view showing a part of a transmission mechanism in a transmission case.

FIG. 6 is a sectional view showing a part of a transmission mechanism in a transmission case.

FIG. 7 is a plan view showing an airframe steering structure.

FIG. 8 is a side view showing an automatic side clutch operation mechanism.

FIG. 9 is a longitudinal rear view showing the right side portion of the rear transmission case.

FIG. 10 is a longitudinal rear view showing a left portion of the rear transmission case.

FIG. 11 is a side view around the main speed change lever.

FIG. 12 is a configuration diagram showing first and second examples of a control structure in a power steering device.

FIG. 13 is a configuration diagram showing a third example of a control structure in the power steering device.

FIG. 14 is a configuration diagram showing a fourth example of a control structure in the power steering device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front wheel 2 Rear wheel 3 Traveling body 4 Working device 96 Side clutch 106 Side clutch automatic operation mechanism 140 Operating tool PS Power steering device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) B62D 49/00 B62D 49/00 F K F term (reference) 2B043 AA03 AB08 BA02 BB06 DB05 DB09 DB20 2B062 AA02 AB01 AB07 BA11 BA18 BA41 CA03 CA05 CB04 3D052 AA01 AA05 AA13 BB08 BB09 BB10 BB12 DD03 EE02 EE03 FF01 GG03 HH01 HH02 HH03 JJ00 JJ02 JJ03 JJ05 JJ08 JJ14 JJ20 JJ21 JJ22 JJ31 JJ37

Claims (4)

[Claims] 1. A power transmission device comprising: a power transmission device configured to transmit a speed-changed power to steerable left and right front wheels and a non-steerable rear wheel; In the riding type paddy working machine with the device connected up and down freely, the left and right rear wheels are equipped with side clutches respectively,
The side clutch automatic operation mechanism for disengaging the side clutch on the inside of the turn and the power steering device can be switched on / off, or the assist ability can be increased in conjunction with the steering of the front wheel by more than the set angle. Power steering function switching means for switching between high and low, if the steering angle of the front wheels is less than the set angle, the power steering device is turned off or the assist ability is low, and the front wheels are set at the set angle. The power steering function switching means is configured to switch the power steering device to an ON state or a state of high assist capability when the side clutch automatic operation mechanism is operated by being steered as described above. Riding paddy working machine. 2. The vehicle according to claim 1, wherein the power is transmitted to the steerable left and right front wheels and the non-steerable rear wheels. In the riding type paddy working machine with the device connected up and down freely, the left and right rear wheels are equipped with side clutches respectively,
Interlocking with the front wheel being steered to a first set angle or more, the side clutch automatic operation mechanism for disengaging the side clutch on the inside of the turn and the power steering device can be switched on / off, or Power steering function switching means for switching the assist ability between high and low, if the steering angle of the front wheels is less than a second set angle smaller than the first set angle, the power steering device is turned off; Alternatively, the power steering function switching is performed such that when the assist ability is low and the front wheels are steered by the second set angle or more, the power steering apparatus is turned on or the assist ability is switched to a high state. A riding paddy working machine characterized by comprising means. 3. The vehicle according to claim 1, further comprising a power transmission device configured to transmit the shifted power to the steerable left and right front wheels and to the unsteerable rear wheels. In the riding type paddy working machine with the device connected up and down freely, the left and right rear wheels are equipped with side clutches respectively,
The side clutch automatic operation mechanism for disengaging the side clutch on the inside of the turn in conjunction with the steering of the front wheel at a set angle or more, and the power steering device can be switched on / off, or the assist capability can be improved. Power steering function switching means for switching between high and low, and an operating tool for giving a forced ascending command for forcibly raising the working device to a predetermined ascending position, wherein the working device is in a working height range, When the power steering device is turned off or the assist ability is low, and when a forced ascending command is given by the operating tool, the power steering device is switched to the on state or the state where the assist ability is high. Riding paddy work characterized by comprising steering function switching means Machine. 4. The vehicle according to claim 1, wherein the speed-changed power is transmitted to steerable left and right front wheels and a non-steerable rear wheel, and the rear of the traveling machine body is provided with a power steering device for steering the front wheels. In a riding type paddy working machine in which the devices are vertically movable, the power steering device can be switched on / off, or a power steering function switching unit for switching an assist capability between high and low, and a unit for detecting a traveling load, When the detected traveling load is less than the set value, the power steering device is turned off or the assist ability is set to a low state, and when the detected traveling load exceeds the set value, the power steering device is turned off. The power steering function switching means is configured to switch to an on state or a state where the assist ability is high. Riding paddy field work machine, wherein the door.