JP2000272373A - Traveling shift structure of paddy field work vehicle - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To configure a traveling transmission so that an operation to a low-speed position can be easily performed. SOLUTION: A shift operation tool 26 is provided which operates a transmission for traveling to a low speed position by a downward push operation and operates a transmission for traveling to a work traveling position by an upward pull operation. Steering wheel 3 for steering operation
8 below. An accelerator-down means is provided for operating the accelerator position of the engine to the low-speed side in conjunction with the operation at the low-speed position. Similarly, the control sensitivity of the control means of the lifting / lowering operation device is changed to the insensitive side. A sensitivity changing unit is provided. The vehicle is provided with a check means for preventing the operation to the low-speed position unless the side brake pedals of the left and right rear wheels are connected. A first transmission for traveling and a second transmission having a low-speed position are arranged in series, and when the second transmission is operated to the low-speed position, the operation of the first transmission to the high-speed side is inhibited. Equipped with restraint prevention means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling speed change structure in a paddy field working vehicle such as a riding type rice transplanter or a riding type direct sowing machine.

[0002]

2. Description of the Related Art In general, a riding type rice transplanter, which is an example of a paddy field working vehicle, travels at a higher speed than a planting traveling speed such as traveling on a paddy field while planting seedlings and traveling on a road. Many high speed running speeds are provided with a variable speed transmission device.

[0003] In a paddy field, there is a height difference between the inside of the paddy (cultivation pad) and the ridge. At times, it has been proposed to configure the vehicle so that it can be stably moved at a low speed. In addition, it is proposed that the paddy field vehicle be lowered from the carrier of the transport truck via the footboard or be mounted on the truck platform so that the machine body can be stably moved at a low speed. Have been. In this case, a low-speed position for low-speed movement lower than the planting traveling speed is provided in the traveling transmission, or in addition to the traveling first transmission that can be freely shifted to the planting traveling speed and the high traveling speed, For example, a second speed change device for traveling that can change speed at a low speed position for low speed movement is arranged in series.

[0004]

At the time of crossing a ridge or loading / unloading a truck to / from a truck as described above, the inclination of the aircraft becomes large. Therefore, it is better for the operator to hold the steering handle and the like with both hands as much as possible. . As a result, when the operator holds the control handle or the like with both hands when crossing the ridge or loading / unloading the truck from / to the loading platform, it may be difficult to operate the low-speed position for low-speed movement.

[0005] In some paddy fields, the ridges may be high or the inclination of the ridges may be steep, and the loading platform of the truck may be high or the stairs may be steeply inclined. Simply operating the transmission (the second transmission for traveling) to the low-speed position for low-speed movement may not be sufficient, and it may be difficult to move the aircraft stably.

[0006] In a riding type rice transplanter which is an example of a paddy field working vehicle, seedlings may be planted while traveling along the ridge at the end of planting seedlings in one paddy field. In this case, the ridge is a place where the aircraft turns during the normal seedling planting process and it is often rough, so there is room for improvement in terms of ensuring that the seedlings are planted properly. is there.

In the paddy field work vehicle, in addition to the first transmission for traveling, a second transmission for traveling which can freely shift to a low speed position for low speed movement.
Some transmissions are arranged in series, and others are provided with right and left side brakes and right and left side brake pedals capable of independently braking the right and left rear wheels for traveling.
As a result, it is necessary to perform appropriate traction control according to the states of the first and second transmissions for traveling and the right and left side brake pedals.

According to the present invention, in a traveling speed change structure of a paddy field working vehicle, the body is stably moved at the time of crossing a ridge or at the time of loading / unloading of a truck so that the operation can be easily performed to a low speed position for low speed movement. In order to stably perform the work traveling along the ridge, appropriate restraint is performed according to the state of the first and second transmissions for traveling and the right and left side brake pedals. And so on.

[0009]

According to a first aspect of the present invention, there is provided a paddy field work in which a low speed position for producing a running speed lower than a work running position in a paddy field is provided in a traveling transmission. In a car, when the shift operation device is pushed downward, the transmission for traveling is operated from the work traveling position to the low speed position, so that the traverse can be performed over a ridge or a truck can be loaded and unloaded. Then, the traveling transmission is operated from the low speed position to the work traveling position. in this case,
According to the first aspect of the present invention, since the shift operation device is disposed below the steering handle, even if the operator holds the control handle with both hands, for example, the driver operates the shift operation device with his / her foot and pushes down. By operating, the transmission for traveling can be operated from the work traveling position to the low speed position. If the pilot has enough time, hold down the shifting device by hand and push it down.
The traveling transmission can be operated from the work traveling position to the low speed position.

According to a second aspect of the present invention, there is provided a paddy field working vehicle having a traveling transmission provided with a low-speed position at which a traveling speed lower than the working traveling position in the paddy field is provided.
When the traveling transmission is operated to the low speed position, the accelerator position of the engine is automatically operated to the low speed side by the accelerator down means in conjunction therewith, and the engine speed is reduced. By configuring so that the number of revolutions of the engine is reduced in addition to the transmission for traveling in this way, a sufficiently low speed state can be obtained. Even if the inclination is steep, the aircraft can be stably moved at a sufficiently low speed. In this case, when the traveling transmission is operated to the low-speed position, the accelerator position of the engine is automatically operated to the low-speed side by the accelerator-down means without manually operating the accelerator position of the engine to the low-speed side. Is done.

As described above, when the traveling transmission is operated to the low speed position, a high torque power is transmitted to the traveling transmission system. In this case, the torque of the power transmitted to the traveling power transmission system can be suppressed by reducing the rotation speed of the engine (to the extent that the engine is not stopped).

[III] According to the feature of claim 3, similar to the case of claim 2, it has the "action" described in the above-mentioned [II], and additionally has the following "action" in addition to this. ing. According to the characteristic of claim 3, after the accelerator position of the engine is automatically operated to the lower speed side by the accelerator-down means in accordance with the operation of the transmission device for the lower speed position, the transmission device for the lower speed is operated. When operated from the position to the high speed side or the original shift position, the accelerator position of the engine is automatically operated to the original position by the accelerator return means.

[IV] In a riding type rice transplanter, which is an example of a paddy field work vehicle, a seedling planting device (working device) connected to the airframe so as to be able to move up and down is installed in a high position from the rice field to the seedling planting device (working device). There is an apparatus provided with an elevating control means for performing an elevating operation based on the detection of the seedling, and the elevating control means maintains the planting depth of the seedling by the seedling planting device (working device) at a set value regardless of the vertical movement of the machine. Is done. In this case, with a riding type rice transplanter, which is an example of a paddy field work vehicle, seedlings may be planted while traveling along the ridge at the end of planting seedlings in one paddy field. Since the aircraft turns during the seedling planting process, it is often rough.

According to a fourth aspect of the present invention, there is provided a paddy field working vehicle provided with a low speed position for producing a running speed lower than the working running position in the paddy field in the traveling transmission, as described above. When the work is performed while traveling on a rough portion such as the above, the traveling transmission may be operated to the low speed position. If the vehicle travels at a lower speed than the work traveling position in the paddy field, it is possible to travel while suppressing the vertical movement of the body even in a rough part such as a ridge.

According to the fourth aspect of the present invention, when the traveling transmission is operated to the low speed position, the control sensitivity of the elevation control means is automatically operated to the insensitive side by the sensitivity changing means. As a result, even when traveling on a rough part such as a ridge, the working device is not moved up and down frequently, causing a hunting phenomenon. The working device is stably moved up and down by the control means. In this case, the traveling transmission is operated at the low-speed position and travels at a speed lower than the work traveling position in the paddy field, and the vertical movement of the aircraft is suppressed, so that the working device is further stabilized by the elevation control means. Lifting operation is performed.

[V] A first transmission for traveling and a second transmission for traveling having a low-speed position for producing a traveling speed lower than the working traveling position in the paddy field are arranged in series. In the paddy field work vehicle, the first traveling device for traveling is operated to the low speed side to perform work traveling in the paddy field, and after the traveling traveling in the paddy field, the second transmission device for traveling is operated to the low speed position, Sometimes crossing ridges or loading / unloading trucks.
In this case, after the ridge over or the loading / unloading of the truck onto / from the truck is completed, the traveling first transmission is operated to the high-speed side while the traveling second transmission is left at the low-speed position to perform on-road traveling or the like. I may go.

According to the fifth aspect of the present invention, when the second transmission for traveling is operated to the low speed position, the operation of the first transmission for traveling toward the high speed side is inhibited by the restraint means. If the second transmission for traveling is operated from the low-speed position to the high-speed side or the original transmission position, the first transmission for traveling can be operated to the high-speed side. Thus, when traveling on a road or the like after levee traversing or loading / unloading of trucks to / from the loading platform is completed, the traveling second transmission is operated at a lower speed while the traveling first transmission is operated at a higher speed. A situation in which it is not possible to obtain a sufficient high-speed state of the aircraft while being operated at the position is avoided.

[VI] In a paddy field working vehicle provided with a low speed position for producing a running speed lower than the working traveling position in the paddy field in the running transmission, the right and left rear wheels for running are respectively independent. Is provided with a brakeable right and left side brake and a right and left side brake pedal. in this case,
For example, when turning to the right and depressing the right side brake pedal to apply braking to the right rear wheel, it is possible to make a small turn to the right, but in this way only one of the right and left side brake pedals It is preferable that the pedal be operated only during work traveling in a paddy field (when turning). In other states, both the right and left side brake pedals are simultaneously operated, and both the right and left side brakes are simultaneously operated. Operate to the braking side and use the right and left side brakes as normal running brakes.

According to a sixth aspect of the present invention, the right and left side brake pedals are in a non-connected state in which each of them can be operated independently, and the right and left side brake pedals are connected so that both of them can be operated simultaneously. When the connecting means is not operated in the connected state, the operation of the traveling transmission to the low speed position is prevented by the restraining means. Thus, by connecting the right and left side brake pedals by the connecting means, even if one of the right and left side brake pedals is depressed, both the right and left side brake pedals are simultaneously depressed, and the right And the left side brake is simultaneously operated on the braking side. In this case, unless the right and left side brake pedals are connected by the connecting means, the operation of the traveling transmission to the low speed position is prevented by the restraining means, so that the right and left side brake pedals are independently depressed. In a non-connected state where operation is possible, a state in which the traveling transmission is operated to the low-speed position to cross a ridge or to unload a truck from the loading platform is avoided.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [1] As shown in FIG. 1, a pair of left and right front wheels 1 and a pair of right and left rear wheels 2 that can be steered left and right.
A steering unit 3 is formed on the body supported by the vehicle, and a seedling planting device 5 is connected to a rear portion of the body by a link mechanism 4 so as to be able to move up and down, so that a four-wheel drive riding type rice planting which is an example of a paddy field work vehicle is provided. Machine is configured.

Next, the structure of the traveling power transmission system will be described. As shown in FIGS. 1 and 4, the engine 6
A transmission case 7 is provided on the rear side of the engine 6. The power of the engine 6 is transmitted via a split pulley type belt-type continuously variable transmission 8 and a friction multi-plate type main clutch 9. 7 is transmitted to the input shaft 10. As shown in FIG. 4, a first transmission shaft 11 and a second transmission shaft 12 are arranged with respect to the input shaft 10, and the first shift gear 13 is integrally rotatably and slidably attached to the first transmission shaft 11 by a spline structure. It is fitted. In the state shown in FIG. 4, the first shift gear 13 is the first gear 10a of the input shaft 10.
It is in a state where it has been slid to the standard position where it engages with
The power of the input shaft 10 is transmitted to the first transmission shaft 11 via the first gear 10a and the first shift gear 13.

A first high-speed gear 14 is rotatably fitted to the first transmission shaft 11 and a second high-speed gear 14 is rotatably fitted to the second gear 10 b and the second transmission shaft 12 of the input shaft 10. The second shift gear 16 is externally engaged with the second transmission shaft 12 by a spline structure so as to be integrally rotatable and slidable.

In the state shown in FIG. 4, the first shift gear 13 is slid to the standard position where it meshes with the first gear 10a of the input shaft 10, and the second shift gear 16 meshes with the low speed gear 11a of the first transmission shaft 11. This is a state where the slide operation is performed to the planting position. In this state, the power of the input shaft 10 is transmitted to the second transmission shaft 1 via the first gear 10a, the first shift gear 13, the low speed gear 11a of the first transmission shaft 11, and the second shift gear 16.
2 is transmitted to the front wheel 1 and the rear wheel 2 via the second transmission shaft 12. The power of the first transmission shaft 11 is
It is transmitted to the seedling planting device 5 via the inter-plant transmission 17. In this state, it is possible to obtain a planting traveling speed for traveling while planting the seedlings in the paddy field.

From the state shown in FIG.
When the second shift gear 16 is slid to a movement position where it engages with the boss of the second high-speed gear 15 while leaving the second shift gear 16 at the standard position where it engages with the first gear 10a of the input shaft 10, the input shaft 10
Is transmitted via the second gear 10b, the first high-speed gear 14, the second high-speed gear 15, and the second shift gear 16 to the second transmission shaft 1
2 is transmitted to the front wheel 1 and the rear wheel 2 via the second transmission shaft 12. In this state, it is possible to obtain a high-speed traveling speed that travels at a higher speed than the planting traveling speed, such as traveling on a road.

From the state shown in FIG.
When the second shift gear 16 is slid to the reverse position where the second shift gear 16 is engaged with the reverse gear pair 18 while the power of the input shaft 10 is kept at the standard position where the input gear 10 is engaged with the first gear 10a, the power of the input shaft 10 Shift gear 13, reverse gear 11b of first transmission shaft 11, reverse gear pair 18, and second shift gear 1
6 is transmitted to the second transmission shaft 12 via the second transmission shaft 1.
2 to the front wheel 1 and the rear wheel 2. In this state, the aircraft can be moved backward.

[2] Next, the slide operation structure of the second shift gear 16 will be described. As shown in FIG. 4, the shift shaft 19 is rotatably (not slidable in the axial direction) supported by the transmission case 7, and the second shift gear 1
The second shift fork 22 that engages with the gear 6 is slidably fitted on the shift shaft 19. An operation arm 20 is swingably supported around an axis (not shown) of the transmission case 7, the operation arm 20 is engaged with the second shift fork 22, and a main transmission provided in the control unit 3 is provided. Lever 23
(See FIG. 1) and the operation arm 20 are mechanically linked.

Thus, the operation arm 20 is swung by the main shift lever 23, and the second shift gear 16 is moved through the second shift fork 22 to the moving position, the planting position, and the reverse position described in the above item [1]. Operate the slide. The second shift fork 22 is provided with a detent ball 22a,
Four shift grooves 19 a are formed in the shift shaft 19, and the detent balls 22 of the second shift fork 22 are formed.
The second shift gear 16 and the second shift fork 22 are held at the moving position, the planting position, the neutral position between the planting position and the reverse position, and the reverse position, as a enters the positioning groove 19a of the shift shaft 19. Is done.

[3] Next, the slide operation structure of the first shift gear 13 will be described. As shown in FIG.
A first shift fork 21 engaged with the shift gear 13 is slidably fitted on the shift shaft 19. A cam portion 21a is formed on the boss portion of the first shift fork 21, and the operation pin 24 is fixed to the shift shaft 19 so as to penetrate in the diameter direction. A spring 25 is provided which is in contact with the portion 21 a and biases the first shift fork 21 toward the operation pin 24 of the shift shaft 19.

As shown in FIGS. 1 and 2, an openable hood 36 for covering the engine 6 is provided.
A power steering mechanism (not shown) of a steering handle 38 for steering the front wheel 1 and a rear bonnet 37 for covering a fuel tank (not shown) are provided on the rear side of 6. Recesses 37a on the right and left sides on the rear side of the rear bonnet 37
Are formed, and the concave portion 3 on the left side of the rear bonnet 37 is formed.
7a, a clutch pedal 35 for operating the main clutch 9 (see FIG. 4) on the transmission side and a transmission cutoff side, and a front wheel differential lock pedal 39 for locking the front wheel differential device (not shown) of the front wheel 1 are arranged. A right side brake pedal 33R and a left side brake pedal 33L are arranged in a concave portion 37a on the right side of 37.

As shown in FIGS. 3 and 4, the shift shaft 19 protrudes from the transmission case 7 so as to be located below the concave portion 37a on the right side of the rear bonnet 37, and an arm 19b at the end of the shift shaft 19 is provided. The ridge-over lever 26 is connected to the ridge-over lever 2 as shown in FIGS.
6 extend upward and are located in the concave portion 37 a on the right side of the rear bonnet 37. Thereby, the ridge over lever 26
By pushing down and pulling up,
The shift shaft 19 is rotated in a range of a predetermined angle (for example, about 90 °).

The state shown in FIGS. 1, 2, 3 and 4 is a state in which the ridge crossing lever 26 is operated to the standard position, and the operation pin 24 of the shift shaft 19 is connected to the cam portion 21a of the first shift fork 21. The first shift gear 1 is opposed to the contact spring 25.
Reference numeral 3 denotes a state in which the slide operation is performed to the standard position where the input gear 10 is engaged with the first gear 10a of the input shaft 10 (refer to the preceding section [1]). In this state, the operator sitting on the cockpit 31 (see FIG. 1) can use the grip 26a of the ridge-over lever 26 with his right hand.
, Or the operator seated in the cockpit 31 pushes down the ridge crossing lever 26 by stepping on the grip portion 26a of the ridge crossing lever 26 with the right foot. Operate to the position over the ridge. Thereby, the shift shaft 19 is rotated by a predetermined angle, and the contact between the operation pin 24 of the shift shaft 19 and the cam portion 21a of the first shift fork 21 and the urging force of the spring 25 cause the shift shaft 19 to rotate.
The first shift fork 21 is connected to the operation pin 24 of the shift shaft 19.
The first shift fork 21 is slid to the position beyond the ridge where the first shift gear 13 is engaged with the side surface of the first high-speed gear 14.

As described above, the first shift gear 13 is connected to the input shaft 1
0 and engages the side surface of the first high-speed gear 14 away from the first gear 10a, the power of the input shaft 10 is transmitted to the first transmission shaft 11 via the second gear 10b and the first high-speed gear 14. As described in the preceding item [1], the power of the input shaft 10 is transmitted from the input shaft 10 to the lower speed than the power transmitted to the first transmission shaft 11 via the first gear 10a and the first shift gear 13. The power is transmitted to one transmission shaft 11. Next, when the ridge crossing lever 26 is operated to the standard position, the grip portion 26a of the ridge crossing lever 26 is held with the right hand and the ridge crossing lever 26 is pulled upward to operate the lever 26 at the standard position.

As described above, while the first shift gear 13 is slid to the position beyond the ridge where it engages with the side surface of the first high-speed gear 14, the second shift gear 16 is implanted as described in the above [1] and [2]. The slide operation can be performed to the attachment position and the reverse position (as described in [7] described later, the second shift gear 16 cannot be slid to the movement position in this state). In this case, the speed of the first shift gear 13 at the position beyond the ridge and at the moving position of the second shift gear 16 is lower than the standard position of the first shift gear 13 and the moving position of the second shift gear 16, and the standard speed of the first shift gear 13 is smaller. The speed is higher than the position and the planting position of the second shift gear 16. The speeds of the first shift gear 13 at the position beyond the ridge and the planting position of the second shift gear 16 are lower than the standard position of the first shift gear 13 and the planting position of the second shift gear 16. The speed in the over position and the reverse position of the second shift gear 16 is the same as that of the first shift gear 13.
Is lower than the standard position and the reverse position of the second shift gear 16.

[4] Next, the speed change operation structure of the belt type continuously variable transmission 8 will be described. As shown in FIGS. 1 and 5, the control unit 3 is provided with a continuously variable transmission lever 27, and a detection value of a position sensor 28 that detects an operation position of the continuously variable transmission lever 27 is input to a control device 29. An operation cylinder 30 for operating the belt-type continuously variable transmission 8 is provided. By operating the continuously variable transmission lever 27 between the highest speed position and the lowest speed position, the control device 29 and the operation cylinder 30 move the continuously variable transmission lever 27 to the transmission position corresponding to the operation position of the continuously variable transmission lever 27. The step transmission 8 is operated. [5] As shown in FIG. 3, a governor lever 34 (accelerator position) of a governor (not shown) provided in the engine 6 is swingably supported around the horizontal axis P1.
1 and the governor lever 34 (accelerator position) are connected by a link rod 42, and the arm 1 of the shift shaft 19
9b and the governor lever 34 (accelerator position)
0 is connected. An accelerator arm 43 is swingably supported around the horizontal axis P2, and the accelerator arm 43 and the governor lever 34 (accelerator position) are connected via a spring 44. A stopper 45 for stopping the accelerator arm 43 at the highest speed position. And stopper 4 for stopping at the lowest speed position
6 are provided.

The control unit 3 is provided with an accelerator pedal (not shown) and a hand accelerator lever (not shown). The accelerator pedal and the accelerator arm 43 are connected via a wire 47, and the hand accelerator lever and the accelerator arm are connected. 43 is connected via a wire 48, and a spring 49 for urging the accelerator arm 43 toward the lowest speed position is provided. By depressing the accelerator pedal,
The wire 47 is pulled toward the highest speed position,
When the foot is released from the accelerator pedal, the accelerator pedal returns to the lowest speed position by a spring (not shown). The hand accelerator lever is provided with a friction holding mechanism (not shown),
Even if the user releases the hand after operating the hand accelerator lever to a desired operation position, the hand accelerator lever is held at the operation position.

As shown in FIG. 3 and FIG.
Is fixed to an end of the operation plate 19c.
ridge over sensor 32 of limit switch type for c
Is arranged. Accordingly, when the ridge-over lever 26 is operated from the standard position to the ridge-over position, the operation plate 19c of the shift shaft 19 comes into contact with the ridge-over sensor 32 with the rotation of the shift shaft 19, and the ridge-over sensor 32 The detection signal is input to the control device 29.

Right and left side brakes (not shown) capable of independently braking the right and left rear wheels 2 are provided. The right side brake pedal 33R and the right side brake shown in FIG. And the left side brake pedal 33L and the left side brake are mechanically linked. By independently depressing the right and left side brake pedals 33R and 33L, the right and left side brakes can be independently operated to the braking side.

As shown in FIG. 5, a connecting arm 50 is swingably supported around the axis P3 of the right side brake pedal 33R, and an engaging portion for engaging the connecting arm 50 with the left side brake pedal 33L. 51 are provided. As a result, as shown in FIG.
1 and the left and right side brake pedals 33R, 33L as described above.
Can be operated independently of each other.

Next, when the connecting arm 50 is swung downward to operate to be engaged with the engaging portion 51, the right and left side brake pedals 33R and 33L are connected, and the right and left side brake pedals 33R and 33L are connected. Left side brake pedal 33R, 33
L can be operated only at the same time. A connection sensor 52 for detecting that the connection arm 50 has been operated to be engaged with the engagement portion 51 is provided on the left side brake pedal 33L, and a detection signal of the connection sensor 52 is input to the control device 29. Is done.

As shown in FIG. 3, a solenoid 54 is arranged near the arm 19b of the shift shaft 19, and when the traction pin 54a of the solenoid 54 is operated to the projecting position,
The restraining pin 54a of the solenoid 54 enters the movement locus of the arm 19b of the shift shaft 19. When the traction pin 54a of the solenoid 54 is thus operated to the projecting position, the arm 19b of the shift shaft 19 is moved to the traction pin 5 of the solenoid 54.
4a, the ridge-over lever 26 cannot be operated from the standard position to the ridge-over position.

[6] Next, a control flow when the ridge crossing lever 26 is operated from the standard position to the ridge crossing position will be described with reference to FIG. The state shown in FIGS. 3 and 4 is a state in which the ridge-over lever 26 is operated to the standard position, and the accelerator arm 43 and the governor lever 34 (accelerator position) are operated to the highest speed position by the hand accelerator lever. In this state, the right side brake pedal 33R
When the connecting arm 50 is operated in the non-connected state (step S1), the drag pin 5 of the solenoid 54 shown in FIG.
4a is operated to the protruding position (step S2), and the ridge over lever 26 cannot be operated from the standard position to the ridge over position.

Next, when the connecting arm 50 of the right side brake pedal 33R is operated to be connected (step S).
1) When the restraining pin 54a of the solenoid 54 shown in FIG. 3 is operated to the retreat position (step S3), the ridge-over lever 2
6 can be operated from the standard position to the position over the ridge.

As a result, when the ridge-crossing lever 26 is operated from the standard position to the ridge-crossing position (step S4), FIG.
The wire 40 shown in FIG. 4 is pulled toward the ridge crossing lever 26 side, and the governor lever 34 of the engine 6 (accelerator position).
Is automatically shifted from the highest speed position to a predetermined low speed position (for example, a position where the rotation speed of the engine 6 becomes 2500 rpm).
(Step S5). In this case, engine 6
Spring 44 along with the governor lever 34 (accelerator position)
Thus, the accelerator arm 43 is also operated to the predetermined low-speed position, and the hand accelerator lever is operated from the highest speed position to the predetermined low-speed position by the wires 47 and 48. The accelerator arm 43 is operated by the accelerator pedal and the hand accelerator lever. (Governor lever 3 of engine 6
4 (accelerator position)) cannot be operated toward the highest speed position.

As described above, when the ridge crossing lever 26 is operated from the standard position to the ridge crossing position (step S4), FIG.
The operation plate 19c of the shift shaft 19 shown in FIG.
2, the detection signal of the ridge-over sensor 32 is input to the control device 29, and the belt-type continuously variable transmission 8 is automatically operated to the lowest speed position by the operation cylinder 30 shown in FIG. 5 (step S6). ). In this case, the continuously variable transmission lever 27
Is left at the operating position before the belt-type continuously variable transmission 8 is automatically operated to the lowest speed position. In this way, the ridge-over lever 26 is operated from the standard position to the ridge-over position (FIG. 4).
(A ridge crossing position where the first shift gear 13 meshes with the side surface of the first high-speed gear 14), and the governor lever 34 of the engine 6
(Accelerator position) is operated at a predetermined low-speed position, and the belt-type continuously variable transmission 8 is operated at the lowest speed position, while moving forward or backward, moving over a ridge or loading / unloading a truck onto a carrier. .

After the crossing of the ridge and the loading / unloading of the truck onto the loading platform are completed as described above, when the ridge crossing lever 26 is operated from the ridge crossing position to the standard position (step S7).
The wire 40 shown in FIG.
(The accelerator position), the governor lever 34 (the accelerator position) of the engine 6 is returned to the original operating position (FIG. 3).
Is operated at the highest speed position in the state shown in FIG.
8). In this case, the hand accelerator lever is left at the predetermined low-speed position, and the accelerator pedal returns to the minimum speed position when the foot is released from the accelerator pedal.

As described above, when the ridge crossing lever 26 is operated from the ridge crossing position to the standard position (step S7), FIG.
The operation plate 19c of the shift shaft 19 shown in FIG.
2, the belt-type continuously variable transmission 8 is operated by the operation cylinder 30 shown in FIG. 5 to operate the continuously variable transmission lever 27 (for example, the belt-type continuously variable transmission 8 is automatically moved to the lowest speed position). The shift position corresponding to the previous operation position) is operated (step S9).

[7] The state shown in FIG.
6, the first shift gear 13 is connected to the first gear 1 of the input shaft 10.
In this state, the slide operation is performed to the standard position where the second shift gear 16 is engaged with the low speed gear 11a of the first transmission shaft 11 by the main transmission lever 23.

In this state, when, for example, the first shift gear 13 is slid to the position beyond the ridge where the first shift gear 13 is engaged with the side surface of the first high-speed gear 14 by the ridge over lever 26, the cam portion 21a of the first shift fork 21 is moved to the second shift fork 22. Get into the side. Thereby, the second shift gear 16 is moved from the planted position shown in FIG.
5, the second shift gear 16 moves to the first shift fork 21.
And the main shift lever 23 cannot slide the second shift gear 16 to the moving position where the second shift gear 16 is engaged with the boss of the second high-speed gear 15.

Conversely, from the state shown in FIG.
When the second shift gear 16 is slid to a moving position where the second shift gear 16 engages with the boss portion of the second high-speed gear 15, the second shift gear 16 enters the first shift fork 21 side. As a result, the first shift gear 13
When the user attempts to slide the standard shift position from the standard position shown in FIG. 4 to a position beyond the ridge that meshes with the side surface of the first high-speed gear 14, the cam portion 21a of the first shift fork 21 comes into contact with the second shift gear 16 and The first shift gear 13 cannot be slid to the position beyond the ridge where the first shift gear 13 engages the side surface of the first high-speed gear 14 by the over lever 26.

[First Embodiment of the Invention] In the above-mentioned [Embodiment of the invention], the raising / lowering control of the seedling planting apparatus 5 and the ridge-over lever 26 may be related as follows. As shown in FIG. 7 and FIG.
The sensor float 53 is arranged, and the rear side of the sensor float 53 is swingably supported around the horizontal axis P3 of the seedling planting apparatus 5, and the front side of the sensor float 53 is swung up and down on the rice field. Follow the ground. Detection arm 5 of potentiometer 55 provided in seedling planting device 5
5a and the front of the sensor float 53 are connected by a rod 56, and a spring 57 for urging the sensor float 53 downward is provided. The detection value of the sensor float 53 from the potentiometer 55 is
9, a dial-type sensitivity setting switch 58 capable of artificially setting the control sensitivity of the elevation control is provided by the control unit 3.
It is prepared for.

With the above structure, when the sensor float 53 follows the ground surface during the planting operation, the detection value of the potentiometer 55 becomes the reference value C (the detection arm 55a of the potentiometer 55 ), The control valve 29 is operated by the control device 29, the hydraulic cylinder 60 of the link mechanism 4 is extended and retracted, and the seedling planting device 5 is automatically moved up and down. Thereby, the seedling planting apparatus 5 is automatically maintained at the set height from the rice field, and the planting depth of the seedling is maintained at the set value.

In the raising / lowering control of the seedling planting apparatus 5 as described above, if there are many irregularities on the rice field, the sensitivity setting switch 58
Is operated to the insensitive side, and accordingly, the reference value C shown in FIG. 7 is changed to the upward side. Thereby, the seedling planting apparatus 5 is automatically moved up and down so that the detection value of the potentiometer 55 becomes the upward reference value C (so that the detection arm 55a of the potentiometer 55 assumes the upward reference value C). Is done. At the upward reference value C, the attitude of the sensor float 53 rises forward, so that the contact area of the sensor float 53 to the rice field decreases, and the spring 5
7 is compressed, and the urging force of the spring 57 is increased. Therefore, the sensitivity of the sensor float 53 to follow the ground on the rice field (the control sensitivity of the elevation control) is changed to the insensitive side.

Conversely, when the unevenness of the rice field is small, the sensitivity setting switch 58 is operated to the sensitive side, and accordingly, the reference value C shown in FIG. 7 is changed to the downward side. Thereby, the seedling planting apparatus 5 is automatically moved up and down so that the detection value of the potentiometer 55 becomes the downward reference value C (so that the detection arm 55a of the potentiometer 55 assumes the downward reference value C). Is done. Downward reference value C
In (2), the posture of the sensor float 53 is lowered forward, so that the contact area of the sensor float 53 to the rice field surface increases, the spring 57 expands, and the urging force of the spring 57 is weakened. Accordingly, the sensitivity of the sensor float 53 to follow the ground surface on the rice field (the control sensitivity of the elevation control) is changed to the sensitive side.

Thus, when the ridge-over lever 26 is operated from the standard position to the ridge-over position, the sensitivity setting switch 58
Irrespective of the operation position, the reference value C shown in FIG. 7 is changed to the upward side, and the sensitivity of the sensor float 53 to follow the ground on the rice field surface (the control sensitivity of the elevation control) is on the insensitive side (for example, the least insensitive state). It is configured to be changed to in this case,
By increasing the width of the dead zone with respect to the reference value C, instead of changing the reference value C upward, the sensitivity of the sensor float 53 to follow the ground on the rice field (control sensitivity of the elevation control) is changed to the insensitive side. It may be configured as follows.

[Second Alternative Embodiment of the Invention] FIGS. 1 and 2
In the configuration shown in (1), the ridge-over lever 26 may be disposed in the concave portion 37a on the left side of the rear bonnet 37, or the ridge-over lever 26 may be disposed on the lateral outside of the right side brake pedal 33R or the clutch pedal 35. The ridge-over lever 26 is located behind the left and right center of the rear hood 37.
May be arranged. Grip part 26 of lever 26 over ridge
a may be configured as a tread surface such as the clutch pedal 35 and the ridge-over lever 26 may be configured as a pedal. The ridge crossing lever 26 may be arranged to protrude rearward or laterally outward from the vertical wall portion of the rear bonnet 37, and the ridge crossing lever 26 may be configured to be swingable up and down.

In step S6 shown in FIG. 6, the belt-type continuously variable transmission 8 is not at the lowest speed position, and the belt-type continuously variable transmission 8 is operated at a low speed position slightly before the minimum speed position. The stepped transmission 8 may be configured to be slowly and gradually operated to the lowest speed position (or a lower speed position slightly before the lowest speed position). Instead of the belt-type continuously variable transmission 8, a hydrostatic continuously variable transmission or a continuously variable transmission configured with a tapered cone may be used.

In FIG. 4, the second shift gear 16 is brought into contact with the cam portion 21a of the first shift fork 21 by the main shift lever 23 to move the second shift gear 16 to the boss portion of the second high speed gear 15 in the moving position. The sliding operation and the sliding operation of the first shift gear 13 to the ridge over position where the first shift gear 13 engages with the side surface of the first high-speed gear 14 by the ridge over lever 26 are eliminated from each other. When the second shift gear 16 is slid to the movement position where it engages with the boss portion of the second high-speed gear 15 by operating the traction pin 54a of the solenoid 54 shown in FIG. You may comprise so that it cannot operate from a standard position to a position over a ridge.

[0058]

According to the first aspect of the present invention, in a paddy field working vehicle provided with a low-speed position for producing a running speed lower than the working traveling position in the paddy field in the traveling transmission, the operator can control, for example, the pilot. Even if you hold the steering wheel with both hands, you can operate the transmission for traveling at a low speed position by stepping and pushing down on the speed change operation tool with your foot, so that Operability was improved.

According to a second aspect of the present invention, in a paddy field working vehicle provided with a low speed position for producing a running speed lower than a work traveling position in a paddy field, the traveling speed change device is provided. When operated to the low speed position, the accelerator position of the engine is automatically operated to the low speed side in conjunction with this,
By configuring so that the engine speed is reduced, it is possible to stably move over ridges and load / unload trucks at a sufficiently low speed, and the traveling performance and handling of paddy field vehicles I was able to improve my sex. According to the second aspect of the present invention, if the number of revolutions of the engine is reduced (to the extent that the engine does not stop), the torque of the power transmitted to the traveling power transmission system can be suppressed, so that the durability of the traveling power transmission system can be reduced. It was also advantageous in terms of sex.

According to the feature of the third aspect, the "effect of the invention" of the second aspect is provided similarly to the case of the second aspect, and in addition to the "effect of the invention", the following "invention" is provided. Of the effect. According to the third aspect of the present invention, after the accelerator position of the engine is automatically moved to the low speed side in accordance with the operation of the traveling transmission to the low speed position, the traveling transmission is moved from the low speed position to the high speed side. When the vehicle is moved to the original shift position, the accelerator position of the engine is automatically moved to the original position, thereby improving the operability of the paddy field work vehicle.

According to a fourth aspect of the present invention, a transmission for traveling having a low-speed position for producing a traveling speed lower than a working traveling position in a paddy field, and detecting a height from the rice field to the working device. In a paddy field vehicle equipped with lifting control means for lifting and lowering the working device based on, when performing work while traveling on a rough portion such as a ridge, when the transmission for traveling is operated to a low speed position, By configuring the control sensitivity of the lifting control means to be automatically operated to the insensitive side, the working equipment is stabilized by the lifting control means without the hunting phenomenon caused by frequent lifting operation of the working equipment. As a result, the operation performance of the paddy field vehicle was improved. According to the feature of the fourth aspect, when performing work while traveling on a rough part such as a ridge, the transmission for traveling is operated at a low speed position and travels at a lower speed than the work travel position in the paddy field. Since the vertical movement of the work device is suppressed, the working device can be more stably moved up and down by the lifting control means, and the work performance of the paddy field working vehicle can be further improved.

According to the fifth aspect of the present invention, there is provided a first transmission for traveling and a second transmission for traveling provided with a low speed position for producing a traveling speed lower than the work traveling position in the paddy field. In a paddy field working vehicle, when the second transmission for traveling is operated at the low speed position, the operation of the first transmission for traveling toward the high speed side is prevented from being restrained, so that the ridge overpass is achieved. When traveling on the road after loading or unloading of trucks or trucks, the second transmission for traveling is operated to the low-speed position while the first transmission for traveling is operated to the high-speed side. It was possible to avoid a situation in which it was not possible to obtain a sufficient high-speed state of the airframe while the vehicle was still standing, and it was possible to improve the traveling performance and handleability of the paddy field working vehicle.

According to a sixth aspect of the present invention, in a paddy field working vehicle provided with a low speed position for producing a running speed lower than a working traveling position in a paddy field, the right and left side brake pedals are provided. When the transmission is not connected, the operation of the transmission for traveling to the low-speed position is prevented from being restrained, so that the right and left side brake pedals can be depressed independently of each other. Improve the traveling performance and handleability of paddy field vehicles, as it avoids the situation of moving the device to a low speed position and crossing ridges or loading / unloading trucks to / from the loading platform. Was completed.

[Brief description of the drawings]

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

FIG. 2 is a perspective view of the vicinity of a rear bonnet in a control section as viewed obliquely from above and behind.

FIG. 3 is a diagram showing a linked state between a governor lever (accelerator position) of an engine and a ridge-crossing lever.

FIG. 4 is a cross-sectional plan view of a transmission case.

FIG. 5 is a block diagram showing a linked state of a control system;

FIG. 6 is a diagram showing a control flow when the ridge-crossing lever is operated from the standard position to the ridge-crossing position.

FIG. 7 is a block diagram showing a linked state of a control system according to the first alternative embodiment of the present invention;

[Explanation of symbols]

 2 Rear wheel 5 Work device 6 Engine 13 Second transmission device for traveling 16 First transmission device for traveling 26 Shift operation tool 33R Right side brake pedal 33L Left side brake pedal 38 Operating handle 40 Accelerator down means 50 Connecting means 54 Retraction means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60K 20/02 B60K 20/02 F 3D041 26/04 26/04 3D052 28/10 28/10 Z 3G065 41 / 28 41/28 3J067 B62D 11/08 B62D 11/08 E 3J070 F02D 11/04 F02D 11/04 G N F16H 61/26 F16H 61/26 63/04 63/04 G05G 5/00 G05G 5/00 D 9 / 00 9/00 A (72) Inventor Hiroaki Kitai 64 Ishizu-Kitacho, Sakai City, Osaka, Japan, inside Kubota Sakai Works, Ltd. (72) Inventor Junji Kurano 64 Ishizu-Kitamachi, Sakai City, Osaka Prefecture, inside Kubota Sakai Works, Ltd. F term (reference) 2B062 AA02 AA04 AA08 AA11 AB01 BA01 BA06 BA22 CA03 CA04 CA05 CA06 CA15 CB04 2B304 KA04 KA08 KA11 KA16 LA02 LA09 LB05 LB16 LC05 MA04 MB02 MC02 PA03 QB14 QB17 RA01 R A02 RA03 RA05 3D036 GA33 GA41 GA45 GB11 GD01 GD05 GF02 GG17 GG53 GH16 GJ12 3D037 EA01 EA03 EB02 EB03 EB12 EC00 FA27 FB01 3D040 AA22 AA28 AA35 AB04 AC29 AD02 AD12 AD13 AE19 AC04 AD04 AC04 AD04 AC04 AE00 AE03 AE12 AE32. BA03 BB04 BB05 CA22 FB61 GA14 3J070 AA03 BA34 CC24 DA24 EA12

Claims (6)

[Claims] 1. A traveling low speed position for producing a traveling speed lower than a work traveling position in a paddy field is provided in a traveling transmission, and the traveling transmission is set to a low position by a downward push operation. A paddy field provided with a shift operating device for operating and operating the transmission for traveling to a work traveling position by an upward pulling operation, wherein the shift operating device is disposed below a steering handle for steering operation. The traveling speed change structure of the work vehicle. 2. A low-speed position for producing a traveling speed lower than a working traveling position in a paddy field is provided in the traveling transmission, and when the traveling transmission is operated to the low-speed position, A traveling speed change structure for a paddy field working vehicle having an accelerator-down means for operating the accelerator position of the engine to a lower speed side in conjunction with the vehicle. 3. An accelerator returning device for operating the accelerator position of the engine to an original position when the traveling transmission is operated from a low speed position to a high speed side while the accelerator down device is operated. 3. The traveling speed change structure for a paddy field working vehicle according to claim 2. 4. A traveling speed change device that has a low-speed position at which a traveling speed lower than a work traveling position in a paddy field is provided, and a working device connected to an airframe so as to be able to ascend and descend from the rice field surface. Up and down control based on height detection up to and when the transmission for traveling is operated to a low speed position, the control sensitivity of the up and down control is changed to the insensitive side in conjunction with this. The traveling speed change structure of a paddy field working vehicle provided with a sensitivity changing means. 5. A first transmission for traveling and a second transmission for traveling having a low-speed position for producing a traveling speed lower than a working traveling position in a paddy field are arranged in series. A traveling speed change structure for a paddy field working vehicle having a check means for preventing the operation of the first transmission device for traveling to a high speed side when the second transmission for traveling is operated at a low speed position; . 6. A low speed position for producing a running speed lower than a working traveling position in a paddy field is provided in a traveling transmission, and the right and left rear wheels for traveling can be independently braked. A right and left side brake; and right and left side brake pedals for independently operating the right and left side brakes on the braking side, respectively. The vehicle is provided with connecting means operable in a connected state, and a connected state in which the right and left side brake pedals are connected so that both of them are simultaneously depressed. The traveling speed change structure of a paddy field working vehicle provided with a check means for preventing the operation of the transmission at a low speed position.