JPH0231925B2 - HOKOGATATAUEKI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a plurality of floats arranged in parallel at the bottom of the fuselage that can freely swing up and down about a rear fulcrum, one of which is used as a sensor float for sensing ground pressure, and this sensor This invention relates to a traveling type rice transplanter equipped with a wheel automatic elevation control device that switches a control valve for raising and lowering wheel hydraulic pressure so that the propulsion wheel is raised and lowered in a direction opposite to the direction of float displacement based on the vertical displacement caused by fluctuations in the ground pressure of the float.

Generally, in rice transplanters, the planting depth is adjusted by adjusting the fulcrum of the float up and down relative to the seedling planting mechanism, but conventionally, the fulcrum height was adjusted for each float placed side by side. However, the adjustment operation was troublesome and
Moreover, if the amount of adjustment for each float was incorrect, there was a risk that the planting depth would be different between the left and right rows.

In addition, especially if there is an adjustment error between the sensor float and other floats, the ground balance of all floats will be different before and after adjustment, which will change the ground pressure sensing characteristics of the sensor float and have a negative impact on automatic wheel elevation control. There was a problem.

The present invention has been made in order to solve the above-mentioned conventional problems, and in the walk-behind rice transplanter having the above configuration, the rear supports of all the floats arranged in parallel at the lower part of the machine are set at a depth of one planting depth. It is unique in that it can be adjusted up and down in the same direction at the same time using an adjustment lever.

According to the above configuration, all the floats can be adjusted up and down correctly by simply operating the lever at one location, making the adjustment operation extremely simple. In particular, because the fulcrum height relationship between the sensor float and other floats does not change before and after adjustment, the aircraft support state by all floats is stable regardless of planting depth adjustment, and ground pressure sensing characteristics are constant. It is now possible to operate the sensor float to perform stable automatic wheel elevation control.

Embodiments of the present invention will be described below based on illustrative drawings.

FIG. 1 and FIG. 2 show the entire walk-behind rice transplanter of the present invention, and the general configuration is as follows.

That is, the engine 2 and the main transmission case 3 are attached to the front ends of a pair of left and right frames 1, 1' that are long in the longitudinal direction of the aircraft, and the frames 1,
A seedling planting section 4 for planting four rows and a control handle 5 are provided at the rear of the seedling planting section 1', and can be raised and lowered between the engine 2 and the seedling planting section 4 and at lateral outer positions of the left and right frames 1 and 1'. two propulsion wheels 6,
A main float 7 is provided at the bottom of the left and right frames 1, 1' and on the lateral outside of the propulsion wheels 6, 6'.
and sub-floats 7', 7' are provided. Transmission cases 8, 8' that are vertically swingable extend rearward from the left and right sides of the main transmission case 3, and the propulsion wheels 6, 6' are attached to the respective tips of the transmission cases 8, 8'. is pivoted. In addition, the seedling planting section 4 includes a seedling resting table 9 that carries and accommodates rectangular continuous seedlings A with continuous soil and is moved laterally in a constant stroke, and a lower end 4 of this seedling resting table 9.
The plant is comprised of a planting device 10 for taking out a certain amount of seedlings from seedling take-out portions a formed at different locations and planting them in a paddy field, and a rear planting case 11 that houses these drive mechanisms.

The rice transplanter configured as described above is supported by floating on the mud surface of the paddy field by the left and right floats 7, 7', 7', and the propulsion wheels 6, which follow the hard plate G of the paddy field,
6', the aircraft travels forward, and as the aircraft advances, seedling planting operations are performed intermittently in the seedling planting section 4, resulting in a constant forward direction on the ground leveling marks where the floats 7, 7', and 7' pass. Four rows of seedlings are planted at intervals.

Next, the suspension structure of the propulsion wheels 6, 6' will be explained based on FIGS. 4 to 6.

The wheel suspension structure of the rice transplanter of the present invention includes propulsion wheels 6,
6' can be adjusted and fixed at any height relative to the aircraft body, the propulsion wheels 6, 6' can be automatically raised and lowered in rice fields according to the depth of the hard plate G, and the left and right wheels 6, 6' can be adjusted and fixed at any height relative to the aircraft. It has the ability to be adjusted to different heights.

That is, an L-shaped lifting arm 13 is pivotally supported on the frames 1 and 1' via a bracket 14, and is pivoted at the tip of the arm 13, and is pivoted up and down by the expansion and contraction of the hydraulic cylinder 12. Balance links 1 are installed at both ends of a movable horizontal support shaft 15.
Near the tips of the wheel transmission cases 8, 8' are supported via shock absorbers 17, 17', and the propulsion wheels 6, 6' are moved in opposite directions by the action of the balancing links 17, 17'. It is configured to allow relative vertical movement. In addition, the support shaft 15 and one balance link 16
The left and right wheels 6, 6' are configured to be relatively rotatable within a certain small range, and within this range, the left and right wheels 6, 6' can be moved up and down independently.

A pump 18 that sucks and discharges the lubricating oil inside the case is directly connected to the upper part of the main transmission case 3, and the oil discharged from the pump 18 is pumped into a hydraulic cylinder by operating a control valve 19 that is further directly connected to the upper part of the pump 18. 12.

The control valve 19 switches and supplies pressure oil to the hydraulic cylinder 12 so that the wheels 6, 6' whose spool 20 is pulled out rises, and when the spool 20 is pushed in, the wheels 6, 6' descend. Further, when the spool 20 is in the push/pull neutral position, the hydraulic cylinder 12 is hydraulically locked and the pump 18 is
Pressure oil from the main transmission case 3 and valve 19
The structure is such that short-circuit flow occurs between the two.

The spool 20 is urged back to the neutral position by an internal spring.

Next, the operation structure of the valve 19 will also be explained.

The spool 20 is connected to an L-shaped arm 21 that is pivotally supported on the upper part of the main transmission case 3, and a first rod 22 that is pivotally supported on one end of the L-shaped arm 21 is connected to the upper surface of the main flow rod 7. It passes through the upper end cylindrical portion 24 of the pivotally supported second rod 23, and both rods 22 and 23 are configured to be extendable and retractable. A coil spring 25 is fitted onto the portion of the first rod 22 above the cylindrical portion 24, and a coil spring 25 is fitted between the upper end of the spring 25 and a first stopper 26 fixed near the upper end of the first rod 22. A gap C ₁ is formed. Further, a second stopper 2 is provided near the lower end of the first rod 22 with an appropriate gap C ₂ between it and the lower end of the cylindrical portion 24.
7 is attached so that its position can be adjusted. The main float 7 and the sub floats 7', 7' are pivoted at their rear parts to the rear transmission case 11 so as to be able to swing up and down by their own weight around a fulcrum P, and at the same time, their front parts are connected to the main transmission case 11. Refraction link 28 at the bottom of 3
This main float 7 is configured as a sensor float that swings vertically relative to the aircraft body as ground pressure changes, and the vertical movement of this main float 7 causes the first and second rods to 22, 22
is expanded or contracted, and the valve 19 is switched.

In other words, when the wheels 6, 6' are set at an appropriate height so as to touch the hard bed G of the paddy field, and when the rice field reaches a deep part of the hard bed G, the aircraft will sink as the wheels 6, 6' sink. The entire body also descends, and the main float 7 floating on the mud surface swings upward relative to the aircraft body, and as a result, the second rod 23 is pushed up. Then, while the amount of pushing up of the rod 23 is smaller than the gap _C1 , the L-shaped arm 21
does not operate, and when the amount of pushing up of the rod 23 becomes larger than the gap _C1 , the spring 25
The upper end contacts the first stopper 26 and the first rod 22 is pushed up via the spring 25, and the L
The spool 2 of the valve 19 is moved by the swing of the mold arm 21.
0 is pushed into the wheel lowering operation side, and the hydraulic cylinder 1
2 is driven to extend, and the wheels 6, 6' are lowered. Then, as the first and second rods 22 and 23 expand relative to each other due to the lifting of the aircraft as the wheels descend, the spool 20 moves to the neutral side, and the upper end of the spring 25 separates from the first stopper 26. At this point, the vehicle returns to neutral and the wheels 6, 6' stop descending. At this time, the wheels 6, 6' slightly overrun due to hydraulic system activation delay, mechanical inertia, etc., and the gap _C1 is again formed. The spring 25 is set to have such a strength that it can exert a resilient force sufficient to overcome the movement resistance of the spool 20 with slight compression.

Moreover, when the hard plate G becomes shallow, the entire body also rises as the wheels 6, 6' push up, and the main float 7 floating on the mud surface swings downward relative to the body.
As a result, the second rod 23 descends. While the amount of descent of the rod 23 is smaller than the gap _C2 , the L-shaped arm 21 does not operate, and when the amount of descent of the rod 23 becomes greater than the gap _C2 , the lower end of the cylindrical portion 24 moves to the second position. The first rod 22 comes into contact with the stopper 27 and is pulled down by the descending force of the main float 7, and the spool 20 is pulled out toward the wheel raising operation side by the swinging of the L-shaped arm 21, and is driven by the hydraulic cylinder 12 and the contraction drive. The wheels 6, 6' rise.
As the first and second rods 22 and 23 contract relative to each other due to the lowering of the aircraft as the wheels rise, the spool 20 moves toward the neutral side, and at the point when the cylindrical portion 24 and the second stopper 27 are separated, the spool 20 moves toward the neutral side. Spool 2
0 returns to neutral and the wheels 6, 6' stop rising.

Further, the control valve 19 is constructed so that it can also be operated by a manual operation structure as described below.

That is, another operating arm 29 and a check arm 30 are integrally pivotally connected to the pivot portion of the L-shaped arm 21, and the check arm 30 has an upper side 21' of the L-shaped arm 21. A bending portion 31 that can be contacted from the rear side of the fuselage body is formed at the bending portion 31 . The operating arm 29 is connected to an operating lever 35 at the rear of the machine via a rod 32, an intermediate swing link 33, and a rod 34. This operating lever 35 is an operating box 3 provided on the operating handle 5.
6 via a support shaft 37 so as to be able to swing back and forth, and by engaging a locking pin 38 provided at the bottom of the lever 35 with a fixed bracket 39, the lever 35 can be moved to an intermediate position between its back and forth swings. It can be fixed, and in the fixed state, the bent part 31 of the check arm 30 is connected to the upper side 2 of the L-shaped arm 21 with the control valve 19 switched to the neutral position.
1'. Further, the lock pin 38 is configured to be unlocked by pushing a knob 40 provided at the upper end of the lever.

Next, the operation of the operation lever 35 for wheel adjustment will be explained.

When the lock is released by operating the knob 40 and the operating lever 35 is swung backward, the check arm 30
is also retracted to the rear, and the L-shaped arm 21 can swing throughout the entire valve operation range. In this state,
As described above, automobile wheel adjustment control is performed as the main float 7 moves up and down. Note that in this state, no operational reaction force is applied to the operating lever 30, so no particular locking is required.

Alternatively, when the operating lever 30 is swung forward from the intermediate position, the check arm 30 abuts and locks the L-shaped arm 21 at the bent portion 31 and moves forward, and the control valve 19 is switched to the wheel lowering operation side. , while the operating lever 35 is swung forward, the propulsion wheel 6,
6' is forcibly lowered and the aircraft is lifted to the ground.
Then, when you release your hand from the operating lever 35, the spool 2
The operating lever 35 is swung backwards by the neutral restoring force of 0, and when it reaches the mid-swing position, the lock pin 3
8 automatically assumes the locked position by the force of the internal spring 41. In this way, when the propulsion wheels 6, 6' are lowered and the aircraft is greatly lifted above the ground, the main foil float 7 floats above the ground, so the weight of the main float 7 is transferred via the first and second rods 22, 23. However, since the restraint arm 30 is fixed together with the operating lever 35, the arm 21 moves in the direction of swinging the L-shaped arm 21 toward the wheel raising side.
The control valve is held in the neutral switching position by contact with the propulsion wheels 6, 6', and the propulsion wheels 6, 6' are fixed at the desired height.
Therefore, when driving on the road, the fuselage, main float 7, and sub floats 7, 7' are lifted from the ground in this state. Incidentally, in order to raise the propulsion wheels 6, 6' which have been forcibly lowered as described above, the operating lever 35 may be swung rearward to the automatic control position.

Furthermore, when the hydraulic cylinder 12, which is activated by switching the control valve 19, reaches its stroke end and the oil pressure increases, a relief valve provided in the discharge oil path of the pump 18 is activated to prevent damage to the hydraulic equipment. However, due to the oil flow resistance where the relief valve operates for a long time, the temperature of the hydraulic oil, which is also the lubricating oil in the main transmission case 3, rises unreasonably, resulting in a decrease in lubrication performance. This also results in accelerated deterioration of the oil. Therefore, the lifting arm 13 and the L-shaped arm 21 are connected via the slide rod 42 so that the L-shaped arm 21 is forcibly returned to the neutral position when the arm 13 for lifting and lowering the wheels reaches its lifting and lowering limits. ing.

Furthermore, this rice transplanter employs the following structure in order to adjust the planting depth.

That is, the rear portions of all the floats 7, 7', 7' are pivotally connected to the tips of arms 44 fixedly extending rearward from a common pivot shaft 43, and
A planting depth adjustment lever 45 is fixed to the support shaft 43, and by swinging and fixing this lever 45, all the arms 44 of the support shaft 43 are integrally swung up and down. The heights of the rear supports P of all the floats 7, 7', 7' can be adjusted simultaneously in the same direction with respect to the planting device 10, so that the planting depth of all rows can be adjusted simultaneously.

In addition, the reference numeral 46 in the figure is the main clutch lever provided in the operation box 36, 47 is the traveling gear shift lever, and 4 is the main clutch lever provided in the operation box 36.
8 is a planting clutch lever, 49 and 49' are steering clutch levers provided on the left and right grips of the steering handle 5, and 50 and 50' are line markers for scratching and forming a travel reference line for the next stroke on the field surface, 51 and 51'
52 and 52' are preliminary seedling support frames provided on the left and right sides of the machine.

[Brief explanation of drawings]

The drawings illustrate embodiments of the rice transplanter according to the present invention, FIG. 1 is an overall side view, FIG. 2 is an overall plan view,
FIG. 3 is a side view of the seedling planting section, FIG. 4 is a side view of the wheel suspension structure, FIG. 5 is a plan view of the wheel suspension structure, and FIG. 6 is a vertical sectional side view of the main part of the wheel suspension structure.
FIG. 7 is a vertical cross-sectional rear view of the operation box section. 6...Propulsion wheel, 7,7',7'...Float,
19... Control valve, 45... Planting depth adjustment lever, P... Rear fulcrum.

Claims (1)

[Claims] 1. A plurality of floats 7, 7', 7' are arranged in parallel at the bottom of the fuselage, which can freely swing up and down about the rear fulcrum P, and one of the floats 7 is used as a sensor float for sensing ground pressure, and this sensor float A walk-behind rice transplanter equipped with an automatic wheel elevation control device that switches a control valve 19 for wheel hydraulic elevation so that the propulsion wheel 6 is elevated or lowered in a direction opposite to the float displacement direction based on the vertical displacement caused by ground pressure fluctuations in the step 7. A walk-behind rice transplanter characterized in that the rear support points P of all the floats 7, 7', 7' can be adjusted up and down simultaneously in the same direction by a single planting depth adjustment lever 45. .