JPH027604B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention has a hydraulically driven propulsion wheel that can be raised and lowered at an intermediate position between the front and back of a fuselage to which a seedling planting device is connected to the rear. A ground float that can move up and down is provided, and the propulsion wheel is driven up and down in the opposite direction to the float displacement direction in response to the up and down movement of the ground float.
The present invention relates to a wheel elevation control device for a walking rice transplanter in which the grounding float and a wheel elevation control valve are linked.

Generally, in a walk-behind rice transplanter, when the rice transplanter is walking forward in a field, the reverse torque caused by the forward rotation of the propulsion wheels acts to tilt the machine body backward, and the rear part of the machine tends to sink. Therefore, by designing the weight balance so that it leans forward when the machine is stopped, it absorbs the backward tilting effect caused by the reverse torque of the wheels, and makes it possible to walk stably in the field by keeping the machine approximately horizontal from front to back. There is.

Therefore, in the middle of planting, if you disengage the main clutch to stop the machine in order to replenish seedlings, etc., and then release your hand from the steering wheel, the machine will tilt forward and downward due to the loss of wheel reverse torque, which causes the wheels to This was detected by a ground float for detecting ground pressure that was protruding further forward, and the wheels were controlled to descend, causing the aircraft to automatically rise significantly and tilt further forward, making it impossible to replenish seedlings.

Conventionally, the structure shown in Fig. 9 was used to solve the above-mentioned problem when the aircraft stopped.

That is, the spool 19 of the control valve 18 and the ground float 6 for ground pressure detection are interlocked and connected by a link 60 biased by a spring 31 in the direction of wheel raising operation, and the spool 19 is moved in and out according to ground pressure fluctuations. A restraining link 6 that constitutes an automatic operation system and that contacts and prevents rotation of the link 60 in conjunction with the operation of the main clutch lever 46 that operates the main clutch operating arm 47 to the clutch disengaged position (OFF).
1 is provided to prevent the spool 19 from being operated from the neutral position n to the wheel lowering position d when the main clutch is disengaged to stop the aircraft.

In addition, when the main clutch is disengaged to stop the machine in order to replenish new seedlings at the edge of a ridge, if the ridge is high and it is difficult to replenish seedlings, it may be necessary to raise the machine further. A lever 41 for lifting and lowering the aircraft body is provided to directly operate the lever 19 to the wheel lowering side, and the restraining link 61
Even when the spring 62 is interposed in the operation system of the link 60 and the check link 61 restricts contact with the link 60, the spring 6
If you operate the lever 41 against 2, the spool 19
It was possible to operate the wheel to lower the wheel.

In other words, when the main clutch is disengaged, the wheels are lowered by operating the lever 41 in the same manner as the ground float 6 is raised, and the weight of the springs 31, 62 and the float 6 is It was quite heavy to operate the lever 41 against the pressure.

The purpose of the present invention is to eliminate the above-mentioned problems of the conventional structure and to enable the wheel lowering operation to be performed relatively easily when the main clutch is disengaged and the aircraft is stopped, and its features are as follows: The spool of the control valve is elastically biased toward the wheel lowering position, and a linking member operatively connected to the spool and a linking member operatively connected to the ground float are linked with a certain degree of flexibility, and the main clutch is A restraining member is provided that contacts and prevents the linking member on the float side from moving from the control neutral position to the wheel lowering operation side in conjunction with the clutch disengagement operation of the lever, and the spool is independently moved to the wheel lowering position. The point is that a lever is provided for switching operations.

According to the above characteristic structure, when the main clutch is disengaged and the aircraft is stopped, the upward movement of the grounding float is checked and prevented, whereas the control valve spool can be moved to the wheel lowering position via the above-mentioned flexibility. Therefore, when operating this spool to the wheel lowering position with a lever, there is no need to pull up the ground float, and the wheels can now be lowered with a relatively light operation.

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

The entire walk-behind rice transplanter is shown in FIGS. 1 and 2, and its general configuration is as follows.

An engine 2 and a transmission case 3 are connected in series to the front end of a main frame 1 made of a round pipe arranged in the left and right center of the aircraft.
A four-row seedling planting device 4 and a control handle 5 are attached to the rear of the machine, and a spare seedling stand 51 is installed at the top of the machine. A hollow plastic center grounding float 6 is provided below the engine 2 and extending to the bottom of the seedling planting device 4. Below the seedling planting device 4, a pair of left and right rear grounding floats 7, 7 are deployed. On the left and right sides of the transmission case 3, wheel transmission cases 8, 8, which are vertically swingable about the front fulcrum X, extend rearward, and propulsion wheels 9, 8 are provided at the rear ends, respectively.
9 is installed.

The seedling planting device 4 includes a seedling platform 10 on which pine-shaped seedlings P are mounted side by side in four rows and moves back and forth laterally at a constant stroke, and a seedling platform 10 that cuts a fixed amount of seedlings from the lower end of the seedling platform 10 and places them in the center and the center. Rear ground float 6,
It is composed of four sets of seedling planting mechanisms 11 for planting on the rice field S leveled in stages 7 and 7, and a rear transmission case 12 equipped with these drive mechanisms.

FIG. 5 shows a suspension structure for the propulsion wheels 9, 9.

A hydraulic cylinder 13 is fixed on the main frame 1, and a balance arm 15, which can swing freely around a vertical fulcrum Y, is attached to a bracket 14 attached to the tip of the piston rod 13a. 15 and each wheel transmission case 8,
Arms 16 and 16 erected from 8 are rod 1
7, 17, both propulsion wheels 9, 9 move up and down simultaneously in the same direction as the piston rod 13a moves in and out, and the left and right wheels 9, 9 are configured to be able to move up and down in opposite directions.

The hydraulic cylinder 13 for lifting and lowering the wheels can be controlled automatically and manually, and its detailed structure will be explained with reference to FIGS. 3 and 4.

A position-switchable control valve 18 is installed on the right side of the transmission case 3 and receives pressure oil from a pump (not shown) that sucks gear oil in the case as hydraulic oil and discharges it under pressure. This control valve 18 and the hydraulic cylinder 13 are connected by piping. The spool 1 of this control valve 18
When the spool 9 is pulled out rearward, the piston rod 13a is operated to protrude and the wheels 9, 9 are lowered, and conversely, when the spool 19 is pushed forward, the piston rod 13a is moved forward.
3a is retired and wheels 9, 9 are raised. As shown in FIG. 7, the spool 19 is given an appropriate neutral restoring force by a single spring 20 that acts in both forward and reverse directions.

A vertical swing link 22 and a downward arm 23 are pivotally connected to a bracket 21 attached to the right side of the mission case 3, and a push/pull link 24 is connected with a pin to the projecting end of the spool 19. , a pair of front and rear pins 25 and 26 implanted on the side surface of the push-pull link 24 extend in an arcuate length in the front and rear direction of the vertical elongated hole 27 formed at the lower end of the swing link 22 and the lower end of the downward arm 23. They are respectively engaged with the holes 28.

Then, the U fixed to the front upper surface of the main frame 1
A coil spring 31 is stretched between one end 30a of a lever 30 attached to one side of the letter-shaped bracket 29 so as to be swingable back and forth, and the upper end of the swing link 22, and the tension of this spring 31 causes the push/pull link 2 to
4 is elastically biased in the direction of pushing the spool 19. Further, the lever 30 is attached to one of the three notched recesses 32 formed on the other side of the bracket 29.
By adjusting the swing of this lever 30, the tension of the spring 31 can be switched and adjusted in three stages.

Further, a horizontal T-shaped link 33 is fixed to the boss portion of the downward arm 23, and this T-shaped link 3
A tension spring 34 is stretched across the lower end of the downward piece 33a of 3 and the rear end of the push/pull link 24, so that the integrated T-shaped link 33 and the downward arm 23 move clockwise with respect to the push/pull link 24. The pin 26 is biased against the front end of the long hole 28.

The central grounding float 6 and the rear grounding floats 7, 7 are each independently supported vertically swingably around a common rear fulcrum Z set near the seedling planting mechanism 11, and the central float 6 is as follows. As shown in , it is linked to the spool 19 of the control valve 18 and is used as a sensor for automatic wheel elevation control.

That is, a first sensor rod 36 is pivotally connected to a U-shaped bracket 35 fixed to the front part of a central ground sensor (hereinafter referred to as a sensor float) 6, and a boss 36a fixed to the upper end of this rod 36
A second sensor rod 37 is inserted through the T-shaped link 33 so as to be slidable up and down, and the upper end of the second sensor rod 37 is pivotally connected to the tip of the rearwardly facing piece 33b of the T-shaped link 33. Said second sensor rod 37
A coil spring 38 whose lower end is supported by the boss 36a is fitted onto the spring 3.
A spring receiving member 39 that receives the upper end of the sensor rod 8 is fixed to the second sensor rod 37 with a pin 40 that can be inserted and removed. This spring receiving member 39 is connected to a pin 40.
The fixing position to the rod 37 can be changed to three levels (up and down) by changing the position of the rod 37. Further, a support piece 39a for receiving the lower end of the boss 36a is integrally connected to the spring receiving member 39, so that even if the spring receiving member 39 is adjusted up and down, the support interval between the upper and lower ends of the spring 38 does not change. ing.

Then, the spring 38 is initially compressed and deformed and assembled at this specified spring support interval, and
This initial pressure is set to be equal to or slightly larger than the sum of the elastic force when the spool biasing spring 31 is adjusted to the maximum strength and the preload force of the neutral restoring spring 20 of the control valve 18.

Next, the operation of the automobile wheel elevation control will be explained.

Fig. 3 shows a control neutral state when the tiller G is at a certain depth; in this state, the wheels 9 are in correct contact with the tiller G, and the machine body is maintained at an appropriate level with respect to the field surface S. There is. At this time, the ground pressure that pushes up the sensor float 6 and the spring 3
1 is balanced and the spool 19 of the control valve 19 is at the neutral position n.

While planting in this state, if the machine reaches a deep part of the tiller G, the entire machine will sink, and the ground pressure of the sensor float 6 will increase. When this float grounding pressure becomes greater than the sum of the biasing force of the spring 31 and the preload force of the neutral restoring spring 20 inside the control valve, the T-shaped link 33 and the downward arm 23 rotate clockwise as a unit and push The pull link 24 is pulled rearward, the spool 19 is switched to the wheel lowering position d, and the wheels 9, 9 that are in contact with the tiller G are forcibly driven downward, so that the machine body is relatively raised. Then, as the body rises, the ground pressure of the sensor float 6 decreases, and when the balanced state is reached again, the spool 19 returns to the neutral position n and the wheel lowering operation is stopped.

Conversely, when the tiller G becomes shallower and the aircraft relatively floats above the field surface S, the sensor float 6
The ground pressure decreases and the balance is lost, and the spool 19 is pushed into the wheel raising position u by the biasing force of the spring 31, and the wheels 9 are raised by the shortening action of the hydraulic cylinder 13, and the aircraft is relatively is lowered. Then, when the float ground pressure increases again to a balanced state as the aircraft descends, the wheel lift is stopped.

In short, the ups and downs of the machine body due to changes in the depth of the tiller G are sensed as changes in the ground pressure of the sensor float 6, and control is based on the vertical displacement of the sensor float 6 relative to the machine body in accordance with this ground pressure variation. The valve 18 is switched and the wheels 9, 9 are controlled to move up and down in the opposite direction to the float displacement direction, and then,
The machine body is always maintained at a substantially constant level with respect to the field surface S, and the planting depth is stabilized.

In this case, the first relatively elastic
Since the spring 38 interposed between the second sensor rods 36 and 37 is assembled with an initial pressure greater than the spool biasing force by the spring 31, the spool 19 is operated from the neutral position n to the wheel lowering position d. At times, the spring 38 is not compressed and the upward displacement of the sensor float 6 is transmitted to the spool 19 via the T-shaped link 33 and the downward arm 23 without delay. In particular, if the tiller G suddenly falls into a deep place or the sensor float 6 rides on a foreign object on the field S, the spool 19 is pulled out to the stroke end and the T-link 33 is rotated clockwise. In the state where the rotation is prevented, the float 6 is still strongly pushed up, and this float grounding pressure is applied to the spring 38.
The spring 38 is compressed and deformed only when the initial pressure of the sensor rod 36,
Deformation and damage at the 37 portion are prevented.

The spool biasing spring 31 is adjusted appropriately depending on the hardness and softness of the field. In a field where the field surface S is soft, the ground pressure will not increase sufficiently unless the sensor float 6 sinks significantly, and the wheel lowering control will not be possible. Since there is a delay, in this case, the tension of the spring 31 is adjusted weakly to reduce the reference float grounding pressure at the neutral time of control, and sensitive control with high sensor sensitivity is performed. On the other hand, in a field where the field surface S is hard, even a small relative vertical displacement between the field surface S and the machine body will cause large fluctuations in the float contact pressure, and even small changes in the tiller G or unevenness of the field surface S will result in frequent wheel control. If this happens, the stability of the aircraft will be more likely to be compromised. Therefore, in such a case, the tension of the spring 31 is set strongly to increase the reference float contact pressure at the neutral time of control, and highly stable control with low sensor sensitivity is performed.

Also, the spring receiving member 39 is connected to the second sensor rod 37.
By adjusting the fixed position up and down with respect to the first and second sensor rods 36 and 37 to increase or decrease the overall length of the first and second sensor rods 36 and 37, it is possible to adjust the reference attitude of the sensor float 6 as a whole in the control neutral state.

For example, in a field where the rice field S is weak, the spring receiving member 3
Adjust 9 downward to remove the first and second sensor rods 3.
6. Lengthen the entire 37. Then, the attitude of the sensor float 6 supported by the rear fulcrum Z at the controlled neutral time is tilted forward. Therefore, in this case, the front part of the float comes into contact with the surface S a lot, and
The sinking of the aircraft can be detected more sensitively.
Further, in a field where the field surface S is hard, the spring receiving member 39 is adjusted upward to shorten the entire sensor rod. Then, in this case, in the sensor float 6, the elevation angle of the bottom surface of the front part of the float with respect to the field surface S becomes large in the standard state, and the unevenness of the field surface S is smoothly guided under the bottom surface of the float, and it becomes easy to press and level it without strain, and
As the front part of the float tends to float, the sensor sensitivity decreases, making it possible to perform control that is less susceptible to small changes in the tiller G and unevenness of the field surface S.

Even if the reference posture of the sensor float 6 is adjusted in this way, the vertical support interval of the spring 38 is constant, the initial pressure application state remains unchanged, and the interaction characteristics between the sensor float 6 and the control valve 18 remain unchanged.

The control valve 18 can also be operated manually, and the structure for this purpose will be described below.

A lever 41 for elevating the aircraft (for elevating wheels) provided at the rear end of the push/pull link 24 and the control handle 5
The release wire 42 has been installed for a long time, and when the lever 41 is set to the "auto" position A of the lever guide 43, the inner wire 42a of the release wire 42 is pushed forward, and the push/pull link 24 is pushed forward. The inner wire end fitting 45 moves forward inside the U-shaped connecting fitting 44 which is pivotally supported by a pin at the rear end, and this fitting 45 and the connecting fitting 44 move forward.
A distance 〓c, which is larger than the stroke for shifting the spool 19 from the neutral position n to the wheel lowered position d, is formed between the bottom of the wheel and the bottom of the wheel. Therefore, in this state,
The push/pull link 24 is movable back and forth over the entire range of spool operation, and can perform the control operations described above.

Furthermore, when the lever 41 is switched to the "body up (wheel down)" position U and locked and fixed, the inner wire 42a is pulled rearward to a greater extent than the distance C, thereby causing the inner wire 42a to The spool 19 is pulled out to the wheel lowering position d, and the body is raised by lowering the wheels.

Further, when the lever 41 is locked and fixed in the "neutral" position N, the inner wire 42a is pulled backward by the distance C, and in this state, the forward movement of the push-pull link 24 is caused by the wire end fitting 45 and the connecting fitting 44. It is blocked by contact with Therefore, if you first switch the lever 41 to the "aircraft raise" position U to raise the aircraft to a desired height, and then switch the lever 41 to the "neutral" position N, even if the sensor float 6 is floating, the above-mentioned The spool 19 connected to the push/pull link 24 is held at the neutral position n, which is held in contact as shown in FIG. Use when driving.

The wheel lift lever 41 is also wire-linked to a clutch (not shown) that cuts off the power to the seedling planting device 4, and the clutch is engaged at the "auto" position A, and the "neutral" position N and " Aircraft rise” position U
Now the clutch is in a disconnected state. This lever 41 can also be locked and held in the "swivel" position T, which corresponds to the middle between the "automatic" position A and the "neutral" position N, and in this position T, the transmission clutch to the seedling planting device 4 is disengaged. and the distance C remains large enough to shift the spool 19 to the wheel lowering position d, and is configured so that the seedling planting operation can be stopped and automatic lifting control can be performed, It is used as follows when the aircraft turns.

That is, when one stroke of planting travel to the vicinity of the ridge is completed, the lever 41 is first switched from the "auto" position A to the "swivel" position T to stop the seedling planting device 41. Next, pull up the control handle 5 slightly to tilt the aircraft slightly forward and downward. Then, the front part of the sensor float 6 is pressed against the field surface S, the ground contact pressure increases, and wheel lowering control is activated. As a result, the machine body is slightly raised, the seedling planting device 4 is floated from the field surface S, and the rear portions of the sensor float 6 and rear grounding floats 7, 7 are also slightly raised from the field surface S. Here, the control handle 5 is kept at a constant height and the aircraft is made to make a U-turn while maintaining the control neutral state.
In this way, the direction of the aircraft can be changed without knocking over the already planted seedlings at the rear of the float or sweeping away much of the mud from the field S on the side of the float. After turning, the lever 41 is returned to the "automatic" position A and the next stroke, planting, is started.

Further, it is preferable that the automatic wheel raising/lowering control described above is not activated when the main clutch is disengaged and the aircraft is stopped.

That is, in general, in a walk-behind rice transplanter, when the rice transplanter is running in a field, the reverse torque caused by the forward rotation of the wheels 9 acts to tilt the machine body backward, and the rear part of the machine body tends to sink. Therefore, the weight balance of the machine is designed so that it leans forward when the machine is stopped, thereby absorbing the backward tilting effect caused by the reverse torque of the wheels and keeping the machine approximately horizontal in the front and back, allowing it to run stably in the field. Therefore, when the main clutch is disengaged to stop the aircraft in order to replenish seedlings during planting, and the control handle 5 is released, the aircraft tilts forward and downward due to the disappearance of wheel reverse torque. This is detected by the sensor float 6, and wheel lowering control is performed, causing the aircraft to rise significantly without permission.
However, there is no problem because the hydraulic mechanism does not work when the engine 2 is stopped and the machine is stopped, but generally the engine is not stopped each time the machine is stopped during work such as replenishing seedlings, so the above problem occurs.

Therefore, it is necessary to check the elevation control when the main clutch is disengaged to stop the aircraft, and the structure for this purpose is incorporated into the elevation control mechanism as follows.

The upper piece 33c of the T-shaped link 33 has an inner part of a release wire 48 which is installed across a main clutch lever 46 provided on the operating handle 5 and a main clutch operating arm 47 provided on the upper surface of the transmission case 3. A wire 48a passes through the inner wire 48a, and a sleeve 49 that can be freely expanded and contracted with a screw is fitted around the front end of the inner wire 48a. Then, the main clutch lever 46 is switched to the clutch release position (OFF), and the wire 4
When the sleeve 8a is pulled backward, the sleeve 4
The rear end of the T-shaped link 33 and the downward arm 23 integrated therewith are prevented from being rotated further clockwise by directly contacting the front surface of the upward piece 33c in the control neutral position. The length of the sleeve 49 is adjusted so that.

In this way, when the main clutch is disengaged to stop the machine in order to replenish seedlings, etc., even if the machine falls forward and the ground pressure of the sensor float 6 increases, the spool 19 will move to the wheel lowered position d. It will no longer be switched to . During work, the machine may suddenly fall into a deep part of the tiller G, causing the machine to lean forward significantly, causing the driver to panic and disengage the main clutch to stop the machine. Therefore, from the state in which the T-shaped link 33 is rotated clockwise first, the T-shaped link 3 is rotated by the contact between the sleeve 49 and the upwardly facing piece 33c.
3 is forcibly rotated clockwise to push the sensor float 6 into the surface S. At this time, the first and second sensor rods 36 and 37, which are subjected to a strong compressive force, are compressed by the interposed spring 38. The deformation shortens it and prevents buckling and breakage.

In addition, when the main clutch is disengaged and the aircraft is stopped, the height of the aircraft may be lower than the ridge, making it difficult to replenish new seedlings. Switch to the "up" position U and pull the push/pull link 24 directly rearward using the wire 42a. Then, since the push/pull link 24 is linked to the downward arm 23 which is prevented from rotating clockwise as described above via the front and rear elongated holes 28 and the pin 26, if the lever 41 is operated a little forcefully, The wheels can be lowered by shifting the link 24 backward against the spring 34, and when the aircraft has risen to an appropriate height, the lever 41 can be moved to the "neutral" position.
Simply switch to position N or "auto" position A.

In addition, the reference numeral 50 in FIG. 3 is in order to prevent the push/pull link 24 from moving forward by coming into contact with the downwardly facing piece 33a of the T-shaped link 33 before the spool 19 reaches the stroke end on the wheel upward side. This is a stopper connected to the bracket 21, and even if the front end of the sensor float 6 unexpectedly enters the field S and a strong external force acts to lower the float 6 by moving forward, this external force will not act on the spool. The control valve 18 is protected.

[Brief explanation of drawings]

The drawings show an embodiment of the wheel elevation control device for a walking rice transplanter according to the present invention, in which FIG. 1 is an overall side view of the rice transplanter, FIG. 2 is an overall plan view of the rice transplanter, and FIG. 3 is a wheel elevation control device. FIG. 4 is a side view of the device, FIG. 4 is a perspective view of the control device, FIG. 5 is a schematic perspective view of the wheel suspension structure, and FIG.
7 is a sectional view taken along the line -- in FIG. 3, FIG. 8 is a perspective view of the operating lever, and FIG. 9 is a schematic diagram of the conventional structure. 4...Seedling planting device, 5...Grounding float, 9...
... Propulsion wheel, 18 ... Control valve, 19 ... Spool, 23 ... Float side linkage member, 24 ... Spool side linkage member, 28 ... Flexibility, 41 ... Lever, 46 ... Main clutch lever, 47...Main clutch operating arm, 48a...Linkage wire, 49
...Restraint member.

Claims (1)

[Scope of Claims] 1. A propulsion wheel 9 that can be raised and lowered by hydraulic drive is provided at an intermediate position between the front and rear of the fuselage to which the seedling planting device 4 is connected to the rear, and a propulsion wheel 9 that can be moved up and down by a hydraulic drive is installed at the bottom of the fuselage so that the front end is located in front of the wheel. A possible grounding float 6 is disposed, and the propulsion wheel 9 is driven up and down in a direction opposite to the float displacement direction in response to the vertical displacement of the grounding float 6.
This is a wheel elevation control device for a walking rice transplanter in which the grounding float 6 and a wheel elevation control valve 18 are linked together, and the spool 19 of the control valve 18 is elastically biased toward the wheel lowering position. Spool 19
The linking member 24 interlockingly connected to the ground float 6 and the linking member 23 interlockingly connected to the ground float 6 are linked with a certain flexibility 28, and the main clutch lever 4
A restraining member 49 is provided which abuts and prevents the float-side linking member 23 from moving from the control neutral position to the wheel lowering operation side in conjunction with the clutch disengagement operation of step 6. Lever 41 for switching operation to lower position d
A wheel lift control device for a walking rice transplanter equipped with 2. The wheel elevation control device according to claim 1, wherein the restraining member 49 is attached to a linking wire 48a that interlocks and connects the main clutch lever 46 and the main clutch operating arm 47.